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Sample records for predict individual efficiency

  1. Predicting Individual Fuel Economy

    SciTech Connect

    Lin, Zhenhong; Greene, David L

    2011-01-01

    To make informed decisions about travel and vehicle purchase, consumers need unbiased and accurate information of the fuel economy they will actually obtain. In the past, the EPA fuel economy estimates based on its 1984 rules have been widely criticized for overestimating on-road fuel economy. In 2008, EPA adopted a new estimation rule. This study compares the usefulness of the EPA's 1984 and 2008 estimates based on their prediction bias and accuracy and attempts to improve the prediction of on-road fuel economies based on consumer and vehicle attributes. We examine the usefulness of the EPA fuel economy estimates using a large sample of self-reported on-road fuel economy data and develop an Individualized Model for more accurately predicting an individual driver's on-road fuel economy based on easily determined vehicle and driver attributes. Accuracy rather than bias appears to have limited the usefulness of the EPA 1984 estimates in predicting on-road MPG. The EPA 2008 estimates appear to be equally inaccurate and substantially more biased relative to the self-reported data. Furthermore, the 2008 estimates exhibit an underestimation bias that increases with increasing fuel economy, suggesting that the new numbers will tend to underestimate the real-world benefits of fuel economy and emissions standards. By including several simple driver and vehicle attributes, the Individualized Model reduces the unexplained variance by over 55% and the standard error by 33% based on an independent test sample. The additional explanatory variables can be easily provided by the individuals.

  2. Developmental dyslexia: predicting individual risk

    PubMed Central

    Thompson, Paul A; Hulme, Charles; Nash, Hannah M; Gooch, Debbie; Hayiou-Thomas, Emma; Snowling, Margaret J

    2015-01-01

    Background Causal theories of dyslexia suggest that it is a heritable disorder, which is the outcome of multiple risk factors. However, whether early screening for dyslexia is viable is not yet known. Methods The study followed children at high risk of dyslexia from preschool through the early primary years assessing them from age 3 years and 6 months (T1) at approximately annual intervals on tasks tapping cognitive, language, and executive-motor skills. The children were recruited to three groups: children at family risk of dyslexia, children with concerns regarding speech, and language development at 3;06 years and controls considered to be typically developing. At 8 years, children were classified as ‘dyslexic’ or not. Logistic regression models were used to predict the individual risk of dyslexia and to investigate how risk factors accumulate to predict poor literacy outcomes. Results Family-risk status was a stronger predictor of dyslexia at 8 years than low language in preschool. Additional predictors in the preschool years include letter knowledge, phonological awareness, rapid automatized naming, and executive skills. At the time of school entry, language skills become significant predictors, and motor skills add a small but significant increase to the prediction probability. We present classification accuracy using different probability cutoffs for logistic regression models and ROC curves to highlight the accumulation of risk factors at the individual level. Conclusions Dyslexia is the outcome of multiple risk factors and children with language difficulties at school entry are at high risk. Family history of dyslexia is a predictor of literacy outcome from the preschool years. However, screening does not reach an acceptable clinical level until close to school entry when letter knowledge, phonological awareness, and RAN, rather than family risk, together provide good sensitivity and specificity as a screening battery. PMID:25832320

  3. Classification images predict absolute efficiency.

    PubMed

    Murray, Richard F; Bennett, Patrick J; Sekuler, Allison B

    2005-02-24

    How well do classification images characterize human observers' strategies in perceptual tasks? We show mathematically that from the classification image of a noisy linear observer, it is possible to recover the observer's absolute efficiency. If we could similarly predict human observers' performance from their classification images, this would suggest that the linear model that underlies use of the classification image method is adequate over the small range of stimuli typically encountered in a classification image experiment, and that a classification image captures most important aspects of human observers' performance over this range. In a contrast discrimination task and in a shape discrimination task, we found that observers' absolute efficiencies were generally well predicted by their classification images, although consistently slightly (approximately 13%) higher than predicted. We consider whether a number of plausible nonlinearities can account for the slight under prediction, and of these we find that only a form of phase uncertainty can account for the discrepancy.

  4. Individual alerting efficiency modulates time perception

    PubMed Central

    Liu, Peiduo; Yang, Wenjing; Yuan, Xiangyong; Bi, Cuihua; Chen, Antao; Huang, Xiting

    2015-01-01

    Time perception plays a fundamental role in human perceptual and motor activities, and can be influenced by various factors, such as selective attention and arousal. However, little is known about the influence of individual alerting efficiency on perceived duration. In this study, we explored this question by running two experiments. The Attentional Networks Test was used to evaluate individual differences in alerting efficiency in each experiment. Temporal bisection (Experiment 1) and time generalization task (Experiment 2) were used to explore the participants’ perception of duration. The results indicated that subjects in the high alerting efficiency group overestimated interval durations and estimated durations more accurately compared with subjects in the low alerting efficiency group. The two experiments showed that the sensitivity of time was not influenced by individual alerting efficiency. Based on previous studies and current findings, we infer that individual differences in alerting efficiency may influence time perception through modulating the latency of the attention-controlled switch and the speed of the peacemaker within the framework of the internal clock model. PMID:25904881

  5. Predicting individual fusional range from optometric data

    NASA Astrophysics Data System (ADS)

    Endrikhovski, Serguei; Jin, Elaine; Miller, Michael E.; Ford, Robert W.

    2005-03-01

    A model was developed to predict the range of disparities that can be fused by an individual user from optometric measurements. This model uses parameters, such as dissociated phoria and fusional reserves, to calculate an individual user"s fusional range (i.e., the disparities that can be fused on stereoscopic displays) when the user views a stereoscopic stimulus from various distances. This model is validated by comparing its output with data from a study in which the individual fusional range of a group of users was quantified while they viewed a stereoscopic display from distances of 0.5, 1.0, and 2.0 meters. Overall, the model provides good data predictions for the majority of the subjects and can be generalized for other viewing conditions. The model may, therefore, be used within a customized stereoscopic system, which would render stereoscopic information in a way that accounts for the individual differences in fusional range. Because the comfort of an individual user also depends on the user"s ability to fuse stereo images, such a system may, consequently, improve the comfort level and viewing experience for people with different stereoscopic fusional capabilities.

  6. Energy efficiency: Perspectives on individual behavior

    SciTech Connect

    Kempton, W.; Neiman, M.

    1986-01-01

    A collection of research papers on the personal behavior and attitudes that affect residential energy use. Articles in the first section address the factors that affect decision-making by consumers; convenience and personal opinions often override rational economic choices. The research in the second section uses aggregate survey data to gain insight into energy behavior. Papers in the third section use detailed monitoring of individual households to analyze personal behavior and home energy management, and the fourth section includes papers on the interaction of building systems with occupants. These papers demonstrate that, to be successful, energy conservation programs must consider the ''human factor'' in addition to the conventional energy parameters (e.g. weather, insulation, and appliance efficiencies). Main emphasis was given to: energy conservation; consumers; personal behavior; economic decision-making; buildings; energy policy; hot water use; thermostats; attitudes; applied anthropology.

  7. Efficiently Finding Individuals from Video Dataset

    NASA Astrophysics Data System (ADS)

    Hao, Pengyi; Kamata, Sei-Ichiro

    We are interested in retrieving video shots or videos containing particular people from a video dataset. Owing to the large variations in pose, illumination conditions, occlusions, hairstyles and facial expressions, face tracks have recently been researched in the fields of face recognition, face retrieval and name labeling from videos. However, when the number of face tracks is very large, conventional methods, which match all or some pairs of faces in face tracks, will not be effective. Therefore, in this paper, an efficient method for finding a given person from a video dataset is presented. In our study, in according to performing research on face tracks in a single video, we also consider how to organize all the faces in videos in a dataset and how to improve the search quality in the query process. Different videos may include the same person; thus, the management of individuals in different videos will be useful for their retrieval. The proposed method includes the following three points. (i) Face tracks of the same person appearing for a period in each video are first connected on the basis of scene information with a time constriction, then all the people in one video are organized by a proposed hierarchical clustering method. (ii) After obtaining the organizational structure of all the people in one video, the people are organized into an upper layer by affinity propagation. (iii) Finally, in the process of querying, a remeasuring method based on the index structure of videos is performed to improve the retrieval accuracy. We also build a video dataset that contains six types of videos: films, TV shows, educational videos, interviews, press conferences and domestic activities. The formation of face tracks in the six types of videos is first researched, then experiments are performed on this video dataset containing more than 1 million faces and 218,786 face tracks. The results show that the proposed approach has high search quality and a short search time.

  8. Effect of Individual Component Life Distribution on Engine Life Prediction

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.; Hendricks, Robert C.; Soditus, Sherry M.

    2003-01-01

    The effect of individual engine component life distributions on engine life prediction was determined. A Weibull-based life and reliability analysis of the NASA Energy Efficient Engine was conducted. The engine s life at a 95 and 99.9 percent probability of survival was determined based upon the engine manufacturer s original life calculations and assumed values of each of the component s cumulative life distributions as represented by a Weibull slope. The lives of the high-pressure turbine (HPT) disks and blades were also evaluated individually and as a system in a similar manner. Knowing the statistical cumulative distribution of each engine component with reasonable engineering certainty is a condition precedent to predicting the life and reliability of an entire engine. The life of a system at a given reliability will be less than the lowest-lived component in the system at the same reliability (probability of survival). Where Weibull slopes of all the engine components are equal, the Weibull slope had a minimal effect on engine L(sub 0.1) life prediction. However, at a probability of survival of 95 percent (L(sub 5) life), life decreased with increasing Weibull slope.

  9. Extraversion predicts individual differences in face recognition.

    PubMed

    Li, Jingguang; Tian, Moqian; Fang, Huizhen; Xu, Miao; Li, He; Liu, Jia

    2010-07-01

    In daily life, one of the most common social tasks we perform is to recognize faces. However, the relation between face recognition ability and social activities is largely unknown. Here we ask whether individuals with better social skills are also better at recognizing faces. We found that extraverts who have better social skills correctly recognized more faces than introverts. However, this advantage was absent when extraverts were asked to recognize non-social stimuli (e.g., flowers). In particular, the underlying facet that makes extraverts better face recognizers is the gregariousness facet that measures the degree of inter-personal interaction. In addition, the link between extraversion and face recognition ability was independent of general cognitive abilities. These findings provide the first evidence that links face recognition ability to our daily activity in social communication, supporting the hypothesis that extraverts are better at decoding social information than introverts.

  10. A Simple Model Predicting Individual Weight Change in Humans

    PubMed Central

    Thomas, Diana M.; Martin, Corby K.; Heymsfield, Steven; Redman, Leanne M.; Schoeller, Dale A.; Levine, James A.

    2010-01-01

    Excessive weight in adults is a national concern with over 2/3 of the US population deemed overweight. Because being overweight has been correlated to numerous diseases such as heart disease and type 2 diabetes, there is a need to understand mechanisms and predict outcomes of weight change and weight maintenance. A simple mathematical model that accurately predicts individual weight change offers opportunities to understand how individuals lose and gain weight and can be used to foster patient adherence to diets in clinical settings. For this purpose, we developed a one dimensional differential equation model of weight change based on the energy balance equation is paired to an algebraic relationship between fat free mass and fat mass derived from a large nationally representative sample of recently released data collected by the Centers for Disease Control. We validate the model's ability to predict individual participants’ weight change by comparing model estimates of final weight data from two recent underfeeding studies and one overfeeding study. Mean absolute error and standard deviation between model predictions and observed measurements of final weights are less than 1.8 ± 1.3 kg for the underfeeding studies and 2.5 ± 1.6 kg for the overfeeding study. Comparison of the model predictions to other one dimensional models of weight change shows improvement in mean absolute error, standard deviation of mean absolute error, and group mean predictions. The maximum absolute individual error decreased by approximately 60% substantiating reliability in individual weight change predictions. The model provides a viable method for estimating individual weight change as a result of changes in intake and determining individual dietary adherence during weight change studies. PMID:24707319

  11. Measuring the operational efficiency of individual theme park attractions.

    PubMed

    Kim, Changhee; Kim, Soowook

    2016-01-01

    This study assesses the operation efficiency of theme park attractions using the data envelopment analysis, utilizing actual data on 15 attractions at Samsung Everland located in Yongin-si, Republic of Korea. In particular, this study identifies crowding and waiting time as one of the main causes of visitor's satisfaction, and analyzes the efficiency of individual attractions in terms of waiting time. The installation area, installation cost, and annual repair cost are set as input factors and the number of annual users and customer satisfaction as output factors. The results show that the roller coaster-type attractions were less efficient than other types of attractions while rotating-type attractions were relatively more efficient. However, an importance performance analysis on individual attraction's efficiency and satisfaction showed that operational efficiency should not be the sole consideration in attraction installation. In addition, the projection points for input factors for efficient use of attractions and the appropriate reference set for benchmarking are provided as guideline for attraction efficiency management.

  12. Measuring the operational efficiency of individual theme park attractions.

    PubMed

    Kim, Changhee; Kim, Soowook

    2016-01-01

    This study assesses the operation efficiency of theme park attractions using the data envelopment analysis, utilizing actual data on 15 attractions at Samsung Everland located in Yongin-si, Republic of Korea. In particular, this study identifies crowding and waiting time as one of the main causes of visitor's satisfaction, and analyzes the efficiency of individual attractions in terms of waiting time. The installation area, installation cost, and annual repair cost are set as input factors and the number of annual users and customer satisfaction as output factors. The results show that the roller coaster-type attractions were less efficient than other types of attractions while rotating-type attractions were relatively more efficient. However, an importance performance analysis on individual attraction's efficiency and satisfaction showed that operational efficiency should not be the sole consideration in attraction installation. In addition, the projection points for input factors for efficient use of attractions and the appropriate reference set for benchmarking are provided as guideline for attraction efficiency management. PMID:27386283

  13. Individual Factors Predicting Mental Health Court Diversion Outcome

    ERIC Educational Resources Information Center

    Verhaaff, Ashley; Scott, Hannah

    2015-01-01

    Objective: This study examined which individual factors predict mental health court diversion outcome among a sample of persons with mental illness participating in a postcharge diversion program. Method: The study employed secondary analysis of existing program records for 419 persons with mental illness in a court diversion program. Results:…

  14. Individual Differences in Statistical Learning Predict Children's Comprehension of Syntax

    ERIC Educational Resources Information Center

    Kidd, Evan; Arciuli, Joanne

    2016-01-01

    Variability in children's language acquisition is likely due to a number of cognitive and social variables. The current study investigated whether individual differences in statistical learning (SL), which has been implicated in language acquisition, independently predicted 6- to 8-year-old's comprehension of syntax. Sixty-eight (N = 68)…

  15. Individual laboratory-measured discount rates predict field behavior

    PubMed Central

    Chabris, Christopher F.; Laibson, David; Morris, Carrie L.; Schuldt, Jonathon P.; Taubinsky, Dmitry

    2009-01-01

    We estimate discount rates of 555 subjects using a laboratory task and find that these individual discount rates predict inter-individual variation in field behaviors (e.g., exercise, BMI, smoking). The correlation between the discount rate and each field behavior is small: none exceeds 0.28 and many are near 0. However, the discount rate has at least as much predictive power as any variable in our dataset (e.g., sex, age, education). The correlation between the discount rate and field behavior rises when field behaviors are aggregated: these correlations range from 0.09-0.38. We present a model that explains why specific intertemporal choice behaviors are only weakly correlated with discount rates, even though discount rates robustly predict aggregates of intertemporal decisions. PMID:19412359

  16. Individual differences in physiological flexibility predict spontaneous avoidance.

    PubMed

    Aldao, Amelia; Dixon-Gordon, Katherine L; De Los Reyes, Andres

    2016-08-01

    People often regulate their emotions by resorting to avoidance, a putatively maladaptive strategy. Prior work suggests that increased psychopathology symptoms predict greater spontaneous utilisation of this strategy. Extending this work, we examined whether heightened resting cardiac vagal tone (which reflects a general ability to regulate emotions in line with contextual demands) predicts decreased spontaneous avoidance. In Study 1, greater resting vagal tone was associated with reduced spontaneous avoidance in response to disgust-eliciting pictures, beyond anxiety and depression symptoms and emotional reactivity. In Study 2, resting vagal tone interacted with anxiety and depression symptoms to predict spontaneous avoidance in response to disgust-eliciting film clips. The positive association between symptoms and spontaneous avoidance was more pronounced among participants with reduced resting vagal tone. Thus, increased resting vagal tone might protect against the use of avoidance. Our findings highlight the importance of assessing both subjective and biological processes when studying individual differences in emotion regulation.

  17. Who punishes? Personality traits predict individual variation in punitive sentiment.

    PubMed

    Roberts, S Craig; Vakirtzis, Antonios; Kristjánsdóttir, Lilja; Havlíček, Jan

    2013-01-01

    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. PMID:23531805

  18. 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.

  19. Individual Identifiability Predicts Population Identifiability in Forensic Microsatellite Markers.

    PubMed

    Algee-Hewitt, Bridget F B; Edge, Michael D; Kim, Jaehee; Li, Jun Z; Rosenberg, Noah A

    2016-04-01

    Highly polymorphic genetic markers with significant potential for distinguishing individual identity are used as a standard tool in forensic testing [1, 2]. At the same time, population-genetic studies have suggested that genetically diverse markers with high individual identifiability also confer information about genetic ancestry [3-6]. The dual influence of polymorphism levels on ancestry inference and forensic desirability suggests that forensically useful marker sets with high levels of individual identifiability might also possess substantial ancestry information. We study a standard forensic marker set-the 13 CODIS loci used in the United States and elsewhere [2, 7-9]-together with 779 additional microsatellites [10], using direct population structure inference to test whether markers with substantial individual identifiability also produce considerable information about ancestry. Despite having been selected for individual identification and not for ancestry inference [11], the CODIS markers generate nontrivial model-based clustering patterns similar to those of other sets of 13 tetranucleotide microsatellites. Although the CODIS markers have relatively low values of the F(ST) divergence statistic, their high heterozygosities produce greater ancestry inference potential than is possessed by less heterozygous marker sets. More generally, we observe that marker sets with greater individual identifiability also tend toward greater population identifiability. We conclude that population identifiability regularly follows as a byproduct of the use of highly polymorphic forensic markers. Our findings have implications for the design of new forensic marker sets and for evaluations of the extent to which individual characteristics beyond identification might be predicted from current and future forensic data.

  20. Predicting individual feed requirements of cattle fed in groups.

    PubMed

    Guiroy, P J; Fox, D G; Tedeschi, L O; Baker, M J; Cravey, M D

    2001-08-01

    A published model designed to predict individual feed required for the observed shrunk BW and ADG of growing cattle when fed in groups was modified and evaluated to improve its accuracy. This model is needed to accurately bill feed and compute cost of gain in marketing programs based on individual animal management. Because of its importance in predicting energy required for growth, a database of 401 steers was used to develop an equation to predict percentage of empty-body fat (EBF) from carcass measurements (12th rib fat thickness, hot carcass weight, USDA quality grade, and longissimus muscle area), which accounted for 61% of the variation in EBF with no bias (P > 0.1). When tested with an independent data set of 951 steers, the equation accounted for 51% of the variation with 1% proportional bias. The large variation in the carcass measurements at a particular EBF observed in this study indicates further improvement is limited by the inability of carcass measurements to account for variation in fat distribution in the various carcass components. Because of its importance in setting the target end point, a database of 1,355 steers and heifers was used to determine the relationship between EBF and USDA quality grade. These data indicate growing and finishing cattle reach Select and low-Choice quality grades at an EBF of 26.15 +/- 0.19 and 28.61 +/- 0.20%, respectively (P < 0.05). A data set of 228 steers from different breeds from two serial slaughter studies indicated 14.26 +/- 1.52 kg of empty BW change are required to increase EBF one percentage unit for cattle fed high-energy diets; this adjustment is needed to adjust final shrunk BW to the target EBF end point. The model to predict DM required with modifications developed in this study was evaluated with data from 365 individually fed cattle and it accounted for 74% of the variation in observed DM consumed with no bias (P > 0.1). When the revised model was applied to a commercial feedlot data set containing

  1. Predicting individual variation in language from infant speech perception measures.

    PubMed

    Cristia, Alejandrina; Seidl, Amanda; Junge, Caroline; Soderstrom, Melanie; Hagoort, Peter

    2014-01-01

    There are increasing reports that individual variation in behavioral and neurophysiological measures of infant speech processing predicts later language outcomes, and specifically concurrent or subsequent vocabulary size. If such findings are held up under scrutiny, they could both illuminate theoretical models of language development and contribute to the prediction of communicative disorders. A qualitative, systematic review of this emergent literature illustrated the variety of approaches that have been used and highlighted some conceptual problems regarding the measurements. A quantitative analysis of the same data established that the bivariate relation was significant, with correlations of similar strength to those found for well-established nonlinguistic predictors of language. Further exploration of infant speech perception predictors, particularly from a methodological perspective, is recommended.

  2. Individual differences in time perspective predict autonoetic experience.

    PubMed

    Arnold, Kathleen M; McDermott, Kathleen B; Szpunar, Karl K

    2011-09-01

    Tulving (1985) posited that the capacity to remember is one facet of a more general capacity-autonoetic (self-knowing) consciousness. Autonoetic consciousness was proposed to underlie the ability for "mental time travel" both into the past (remembering) and into the future to envision potential future episodes (episodic future thinking). The current study examines whether individual differences can predict autonoetic experience. Specifically, the Zimbardo Time Perspective Inventory (ZTPI, Zimbardo & Boyd, 1999) was administered to 133 undergraduate students, who also rated phenomenological experiences accompanying autobiographical remembering and episodic future thinking. Scores on two of the five subscales of the ZTPI (Future and Present-Hedonistic) predicted the degree to which people reported feelings of mentally traveling backward (or forward) in time and the degree to which they reported re- or pre-experiencing the event, but not ten other rated properties less related to autonoetic consciousness.

  3. Folk beliefs about genetic variation predict avoidance of biracial individuals

    PubMed Central

    Kang, Sonia K.; Plaks, Jason E.; Remedios, Jessica D.

    2015-01-01

    People give widely varying estimates for the amount of genetic overlap that exists between humans. While some laypeople believe that humans are highly genetically similar to one another, others believe that humans share very little genetic overlap. These studies examine how beliefs about genetic overlap affect neural and evaluative reactions to racially-ambiguous and biracial targets. In Study 1, we found that lower genetic overlap estimates predicted a stronger neural avoidance response to biracial compared to monoracial targets. In Study 2, we found that lower genetic overlap estimates predicted longer response times to classify biracial (vs. monoracial) faces into racial categories. In Study 3, we manipulated genetic overlap beliefs and found that participants in the low overlap condition explicitly rated biracial targets more negatively than those in the high overlap condition. Taken together, these data suggest that genetic overlap beliefs influence perceivers’ processing fluency and evaluation of biracial and racially-ambiguous individuals. PMID:25904875

  4. Individual differences during acquisition predict shifts in generalization.

    PubMed

    Wisniewski, Matthew G; Church, Barbara A; Mercado, Eduardo

    2014-05-01

    Learning to distinguish subtle differences in objects or events can impact how one generalizes. In some cases, training can cause novel events to appear more familiar or attractive than those actually experienced during training: the peak shift effect. This study examined whether individual differences in learning led to systematic patterns of generalization. Participants were trained to identify simulated birdsongs, and then tested on their ability to identify a target song presented among several similar songs that differed in pitch. Initial analysis showed that those attaining moderate proficiency at discriminating songs during training were more likely to shift than those performing poorly or proficiently. However, a neural network trained to output individuals' gradient dynamics using only performance during training as input found an additional set of training variables that predicted shift. Specifically, one subset of shifters had highly conservative response biases accompanied by very little change to perceptual sensitivity in training. These findings suggest that discrimination learning may only lead to generalization shifts in some individuals, and that all individuals who shift may not do so for the same reason.

  5. Working memory delay activity predicts individual differences in cognitive abilities.

    PubMed

    Unsworth, Nash; Fukuda, Keisuke; Awh, Edward; Vogel, Edward K

    2015-05-01

    A great deal of prior research has examined the relation between estimates of working memory and cognitive abilities. Yet, the neural mechanisms that account for these relations are still not very well understood. The current study explored whether individual differences in working memory delay activity would be a significant predictor of cognitive abilities. A large number of participants performed multiple measures of capacity, attention control, long-term memory, working memory span, and fluid intelligence, and latent variable analyses were used to examine the data. During two working memory change detection tasks, we acquired EEG data and examined the contralateral delay activity. The results demonstrated that the contralateral delay activity was significantly related to cognitive abilities, and importantly these relations were because of individual differences in both capacity and attention control. These results suggest that individual differences in working memory delay activity predict individual differences in a broad range of cognitive abilities, and this is because of both differences in the number of items that can be maintained and the ability to control access to working memory. PMID:25436671

  6. Working Memory Delay Activity Predicts Individual Differences in Cognitive Abilities

    PubMed Central

    Unsworth, Nash; Fukuda, Keisuke; Awh, Edward; Vogel, Edward K.

    2015-01-01

    A great deal of prior research has examined the relation between estimates of working memory and cognitive abilities. Yet, the neural mechanisms that account for these relations are still not very well understood. The current study explored whether individual differences in working memory delay activity would be a significant predictor of cognitive abilities. A large number of participants performed multiple measures of capacity, attention control, long-term memory, working memory span, and fluid intelligence, and latent variable analyses were used to examine the data. During two working memory change detection tasks, we acquired EEG data and examined the contra-lateral delay activity. The results demonstrated that the contralateral delay activity was significantly related to cognitive abilities, and importantly these relations were because of individual differences in both capacity and attention control. These results suggest that individual differences in working memory delay activity predict individual differences in a broad range of cognitive abilities, and this is because of both differences in the number of items that can be maintained and the ability to control access to working memory. PMID:25436671

  7. Individual differences during acquisition predict shifts in generalization.

    PubMed

    Wisniewski, Matthew G; Church, Barbara A; Mercado, Eduardo

    2014-05-01

    Learning to distinguish subtle differences in objects or events can impact how one generalizes. In some cases, training can cause novel events to appear more familiar or attractive than those actually experienced during training: the peak shift effect. This study examined whether individual differences in learning led to systematic patterns of generalization. Participants were trained to identify simulated birdsongs, and then tested on their ability to identify a target song presented among several similar songs that differed in pitch. Initial analysis showed that those attaining moderate proficiency at discriminating songs during training were more likely to shift than those performing poorly or proficiently. However, a neural network trained to output individuals' gradient dynamics using only performance during training as input found an additional set of training variables that predicted shift. Specifically, one subset of shifters had highly conservative response biases accompanied by very little change to perceptual sensitivity in training. These findings suggest that discrimination learning may only lead to generalization shifts in some individuals, and that all individuals who shift may not do so for the same reason. PMID:24445021

  8. Masting promotes individual- and population-level reproduction by increasing pollination efficiency.

    PubMed

    Moreira, Xoaquín; Abdala-Roberts, Luis; Linhart, Yan B; Mooney, Kailen A

    2014-04-01

    Masting is a reproductive strategy defined as the intermittent and synchronized production of large seed crops by a plant population. The pollination efficiency hypothesis proposes that masting increases pollination success in plants. Despite its general appeal, no previous studies have used long-term data together with population- and individual-level analyses to assess pollination efficiency between mast and non-mast events. Here we rigorously tested the pollination efficiency hypothesis in ponderosa pine (Pinus ponderosa), a long-lived monoecious, wind-pollinated species, using a data set on 217 trees monitored annually for 20 years. Relative investment in male and female function by individual trees did not vary between mast and non-mast years. At both the population and individual level, the rate of production of mature female cones relative to male strobili production was higher in mast than non-mast years, consistent with the predicted benefit of reproductive synchrony on reproductive success. In addition, at the individual level we found a higher conversion of unfertilized female conelets into mature female cones during a mast year compared to a non-mast year. Collectively, parallel results at the population and individual tree level provide robust evidence for the ecological, and potentially also evolutionary, benefits of masting through increased pollination efficiency.

  9. Prediction and Quantification of Individual Athletic Performance of Runners

    PubMed Central

    2016-01-01

    We present a novel, quantitative view on the human athletic performance of individual runners. We obtain a predictor for running performance, a parsimonious model and a training state summary consisting of three numbers by application of modern validation techniques and recent advances in machine learning to the thepowerof10 database of British runners’ performances (164,746 individuals, 1,417,432 performances). Our predictor achieves an average prediction error (out-of-sample) of e.g. 3.6 min on elite Marathon performances and 0.3 seconds on 100 metres performances, and a lower error than the state-of-the-art in performance prediction (30% improvement, RMSE) over a range of distances. We are also the first to report on a systematic comparison of predictors for running performance. Our model has three parameters per runner, and three components which are the same for all runners. The first component of the model corresponds to a power law with exponent dependent on the runner which achieves a better goodness-of-fit than known power laws in the study of running. Many documented phenomena in quantitative sports science, such as the form of scoring tables, the success of existing prediction methods including Riegel’s formula, the Purdy points scheme, the power law for world records performances and the broken power law for world record speeds may be explained on the basis of our findings in a unified way. We provide strong evidence that the three parameters per runner are related to physiological and behavioural parameters, such as training state, event specialization and age, which allows us to derive novel physiological hypotheses relating to athletic performance. We conjecture on this basis that our findings will be vital in exercise physiology, race planning, the study of aging and training regime design. PMID:27336162

  10. Prediction and Quantification of Individual Athletic Performance of Runners.

    PubMed

    Blythe, Duncan A J; Király, Franz J

    2016-01-01

    We present a novel, quantitative view on the human athletic performance of individual runners. We obtain a predictor for running performance, a parsimonious model and a training state summary consisting of three numbers by application of modern validation techniques and recent advances in machine learning to the thepowerof10 database of British runners' performances (164,746 individuals, 1,417,432 performances). Our predictor achieves an average prediction error (out-of-sample) of e.g. 3.6 min on elite Marathon performances and 0.3 seconds on 100 metres performances, and a lower error than the state-of-the-art in performance prediction (30% improvement, RMSE) over a range of distances. We are also the first to report on a systematic comparison of predictors for running performance. Our model has three parameters per runner, and three components which are the same for all runners. The first component of the model corresponds to a power law with exponent dependent on the runner which achieves a better goodness-of-fit than known power laws in the study of running. Many documented phenomena in quantitative sports science, such as the form of scoring tables, the success of existing prediction methods including Riegel's formula, the Purdy points scheme, the power law for world records performances and the broken power law for world record speeds may be explained on the basis of our findings in a unified way. We provide strong evidence that the three parameters per runner are related to physiological and behavioural parameters, such as training state, event specialization and age, which allows us to derive novel physiological hypotheses relating to athletic performance. We conjecture on this basis that our findings will be vital in exercise physiology, race planning, the study of aging and training regime design. PMID:27336162

  11. Dopaminergic genes predict individual differences in susceptibility to confirmation bias

    PubMed Central

    Doll, Bradley B.; Hutchison, Kent E.; Frank, Michael J.

    2011-01-01

    The striatum is critical for the incremental learning of values associated with behavioral actions. The pre-frontal cortex (PFC) represents abstract rules and explicit contingencies to support rapid behavioral adaptation in the absence of cumulative experience. Here we test two alternative models of the interaction between these systems, and individual differences thereof, when human subjects are instructed with prior information about reward contingencies that may or may not be accurate. Behaviorally, subjects are overly influenced by prior instructions, at the expense of learning true reinforcement statistics. Computational analysis found that this pattern of data is best accounted for by a confirmation bias mechanism in which prior beliefs - putatively represented in PFC - influence the learning that occurs in the striatum such that reinforcement statistics are distorted. We assessed genetic variants affecting prefrontal and striatal dopaminergic neurotransmission. A polymorphism in the COMT gene (rs4680), associated with prefrontal dopaminergic function, was predictive of the degree to which participants persisted in responding in accordance with prior instructions even as evidence against their veracity accumulated. Polymorphisms in genes associated with striatal dopamine function (DARPP-32, rs907094, and DRD2, rs6277), were predictive of learning from positive and negative outcomes. Notably, these same variants were predictive of the degree to which such learning was overly inflated or neglected when outcomes are consistent or inconsistent with prior instructions. These findings indicate dissociable neurocomputational and genetic mechanisms by which initial biases are strengthened by experience. PMID:21508242

  12. Individual Differences in Nonsymbolic Ratio Processing Predict Symbolic Math Performance.

    PubMed

    Matthews, Percival G; Lewis, Mark Rose; Hubbard, Edward M

    2016-02-01

    What basic capacities lay the foundation for advanced numerical cognition? Are there basic nonsymbolic abilities that support the understanding of advanced numerical concepts, such as fractions? To date, most theories have posited that previously identified core numerical systems, such as the approximate number system (ANS), are ill-suited for learning fraction concepts. However, recent research in developmental psychology and neuroscience has revealed a ratio-processing system (RPS) that is sensitive to magnitudes of nonsymbolic ratios and may be ideally suited for supporting fraction concepts. We provide evidence for this hypothesis by showing that individual differences in RPS acuity predict performance on four measures of mathematical competence, including a university entrance exam in algebra. We suggest that the nonsymbolic RPS may support symbolic fraction understanding much as the ANS supports whole-number concepts. Thus, even abstract mathematical concepts, such as fractions, may be grounded not only in higher-order logic and language, but also in basic nonsymbolic processing abilities.

  13. Efficient prediction of (p,n) yields

    SciTech Connect

    Swift, D C; McNaney, J M; Higginson, D P; Beg, F

    2009-09-09

    In the continuous deceleration approximation, charged particles decelerate without any spread in energy as they traverse matter. This approximation simplifies the calculation of the yield of nuclear reactions, for which the cross-section depends on the particle energy. We calculated (p,n) yields for a LiF target, using the Bethe-Bloch relation for proton deceleration, and predicted that the maximum yield would be around 0.25% neutrons per incident proton, for an initial proton energy of 70 MeV or higher. Yield-energy relations calculated in this way can readily be used to optimize source and (p,n) converter characteristics.

  14. Individual differences in saccharin acceptance predict rats' food intake.

    PubMed

    Boakes, Robert A; Martire, Sarah I; Rooney, Kieron B; Kendig, Michael D

    2016-10-01

    Following previous results indicating that low acceptance of saccharin-sweetened yoghurt was associated with slower weight gain, the aim of this experiment was to determine which of three measures of individual differences would predict subsequent chow consumption, body weight gain, and fat mass. Pre-test measures consisted of amount of running in an activity wheel, amount of 0.1% saccharin solution consumed over 24h, and performance on an elevated plus maze (EPM). Rats were then maintained for three weeks on a diet of standard chow and water. Subsequent post-testing repeated the procedures used in pre-testing. The rats were then culled and fat pads excised and weighed. Pre-testing revealed a negative correlation between saccharin acceptance and activity, while neither measure correlated with anxiety in the EPM. Pre-test saccharin acceptance was positively correlated with subsequent chow consumption, percent weight gain, and g/kg fat mass. Multiple regression analyses including all three pre-test measures confirmed saccharin acceptance as a predictor of chow consumption and, marginally, of fat pad mass, while high anxiety predicted low percent body weight gain. PMID:27260516

  15. Rare Copy Number Deletions Predict Individual Variation in Intelligence

    PubMed Central

    Yeo, Ronald A.; Gangestad, Steven W.; Liu, Jingyu; Calhoun, Vince D.; Hutchison, Kent E.

    2011-01-01

    Phenotypic variation in human intellectual functioning shows substantial heritability, as demonstrated by a long history of behavior genetic studies. Many recent molecular genetic studies have attempted to uncover specific genetic variations responsible for this heritability, but identified effects capture little variance and have proven difficult to replicate. The present study, motivated an interest in “mutation load” emerging from evolutionary perspectives, examined the importance of the number of rare (or infrequent) copy number variations (CNVs), and the total number of base pairs included in such deletions, for psychometric intelligence. Genetic data was collected using the Illumina 1MDuoBeadChip Array from a sample of 202 adult individuals with alcohol dependence, and a subset of these (N = 77) had been administered the Wechsler Abbreviated Scale of Intelligence (WASI). After removing CNV outliers, the impact of rare genetic deletions on psychometric intelligence was investigated in 74 individuals. The total length of the rare deletions significantly and negatively predicted intelligence (r = −.30, p = .01). As prior studies have indicated greater heritability in individuals with relatively higher parental socioeconomic status (SES), we also examined the impact of ethnicity (Anglo/White vs. Other), as a proxy measure of SES; these groups did not differ on any genetic variable. This categorical variable significantly moderated the effect of length of deletions on intelligence, with larger effects being noted in the Anglo/White group. Overall, these results suggest that rare deletions (between 5% and 1% population frequency or less) adversely affect intellectual functioning, and that pleotropic effects might partly account for the association of intelligence with health and mental health status. Significant limitations of this research, including issues of generalizability and CNV measurement, are discussed. PMID:21298096

  16. Efficiency of individual dosage of digoxin with calculated concentration

    PubMed Central

    Zhao, Li; Yang, Peng; Li, Pengmei; Wang, Xiaoxing; Qin, Wangjun; Zhang, Xianglin

    2014-01-01

    Background Digoxin is a frequently prescribed drug, particularly in the elderly population, in which there is an increased prevalence of atrial fibrillation and cardiac failure. With its complex pharmacokinetic profile and narrow therapeutic index, use of digoxin requires regular monitoring of blood levels. Recent evidence suggests that a lower concentration range (0.4–1.0 ng/mL) is preferable in patients with congestive heart failure and a higher range (0.8–2.0 ng/mL) is needed in patients with atrial tachyarrhythmia. The Konishi equation is widely used to predict the serum digoxin concentration (SDC) in Japan. This study assessed the correlation between SDC predicted by the Konishi equation and that actually measured in Chinese patients and investigated the impact of renal function on SDC. Methods The study subjects comprised 72 patients with cardiac failure or/and atrial tachyarrhythmia seen at our hospital from January 2012 to December 2013. The patients were divided into five groups according to Kidney Diseases Outcome Quality Initiative guidelines. SDCs were measured using the Abbott Architect i1000 immunology analyzer. The correlations between measured SDCs and calculated SDCs and between clearance of digoxin and creatinine clearance rate were assessed retrospectively. Results The correlation between measured and predicted SDC calculated by the Konishi equation was significant (r=0.655, P<0.001) for the 72 patients overall; however, correlations within the different stages of renal function were nonsignificant, with a correlation found only in patients with stage 3 (30 mL per minute < creatinine clearance <60 mL per minute). With regard to the correlation between clearance of digoxin and creatinine clearance, our results show that although there was a significant correlation between clearance of digoxin and creatinine clearance in the group overall, correlations were not evident within the different stages of renal function. Conclusion The results of

  17. Individual Differences in Nonsymbolic Ratio Processing Predict Symbolic Math Performance.

    PubMed

    Matthews, Percival G; Lewis, Mark Rose; Hubbard, Edward M

    2016-02-01

    What basic capacities lay the foundation for advanced numerical cognition? Are there basic nonsymbolic abilities that support the understanding of advanced numerical concepts, such as fractions? To date, most theories have posited that previously identified core numerical systems, such as the approximate number system (ANS), are ill-suited for learning fraction concepts. However, recent research in developmental psychology and neuroscience has revealed a ratio-processing system (RPS) that is sensitive to magnitudes of nonsymbolic ratios and may be ideally suited for supporting fraction concepts. We provide evidence for this hypothesis by showing that individual differences in RPS acuity predict performance on four measures of mathematical competence, including a university entrance exam in algebra. We suggest that the nonsymbolic RPS may support symbolic fraction understanding much as the ANS supports whole-number concepts. Thus, even abstract mathematical concepts, such as fractions, may be grounded not only in higher-order logic and language, but also in basic nonsymbolic processing abilities. PMID:26710824

  18. Coherent motion sensitivity predicts individual differences in subtraction.

    PubMed

    Boets, Bart; De Smedt, Bert; Ghesquière, Pol

    2011-01-01

    Recent findings suggest deficits in coherent motion sensitivity, an index of visual dorsal stream functioning, in children with poor mathematical skills or dyscalculia, a specific learning disability in mathematics. We extended these data using a longitudinal design to unravel whether visual dorsal stream functioning is able to predict individual differences in subsequent specific mathematical skills, i.e., single-digit subtraction and multiplication. We measured children's sensitivity to coherent motion in kindergarten (mean age: 5 years 8 months) and evaluated their subtraction and multiplication skills in third grade (mean age 8 years 3 months). Findings revealed an association between subtraction but not multiplication performance and coherent motion sensitivity. This association remained significant even when intellectual ability and reading ability were additionally controlled for. Subtractions are typically solved by means of quantity-based procedural strategies, which reliably recruit the intraparietal sulcus. Against the background of a neural overlap between the intraparietal sulcus and visual dorsal stream functioning, we hypothesize that low-level visuospatial mechanisms might set constraints on the development of quantity representations, which are used during calculation, particularly in subtraction. PMID:21324638

  19. Culture and self in South Africa: individualism-collectivism predictions.

    PubMed

    Eaton, L; Louw, J

    2000-04-01

    People from collectivist cultures may have more concrete and interdependent self-concepts than do people from individualist cultures (G. Hofstede, 1980). African cultures are considered collectivist (H. C. Triandis, 1989), but research on self-concept and culture has neglected this continent. The authors attempted a partial replication in an African context of cross-cultural findings on the abstract-concrete and independent-interdependent dimensions of self-construal (referred to as the abstract-specific and the autonomous-social dimensions, respectively, by E. Rhee, J. S. Uleman, H. K. Lee, & R. J. Roman, 1995). University students in South Africa took the 20 Statements Test (M. Kuhn & T. S. McPartland, 1954; Rhee et al.); home languages were rough indicators of cultural identity. The authors used 3 coding schemes to analyze the content of 78 protocols from African-language speakers and 77 protocols from English speakers. In accord with predictions from individualism-collectivism theory, the African-language speakers produced more interdependent and concrete self-descriptions than did the English speakers. Additional findings concerned the orthogonality of the 2 dimensions and the nature and assessment of the social self-concept. PMID:10808644

  20. Culture and self in South Africa: individualism-collectivism predictions.

    PubMed

    Eaton, L; Louw, J

    2000-04-01

    People from collectivist cultures may have more concrete and interdependent self-concepts than do people from individualist cultures (G. Hofstede, 1980). African cultures are considered collectivist (H. C. Triandis, 1989), but research on self-concept and culture has neglected this continent. The authors attempted a partial replication in an African context of cross-cultural findings on the abstract-concrete and independent-interdependent dimensions of self-construal (referred to as the abstract-specific and the autonomous-social dimensions, respectively, by E. Rhee, J. S. Uleman, H. K. Lee, & R. J. Roman, 1995). University students in South Africa took the 20 Statements Test (M. Kuhn & T. S. McPartland, 1954; Rhee et al.); home languages were rough indicators of cultural identity. The authors used 3 coding schemes to analyze the content of 78 protocols from African-language speakers and 77 protocols from English speakers. In accord with predictions from individualism-collectivism theory, the African-language speakers produced more interdependent and concrete self-descriptions than did the English speakers. Additional findings concerned the orthogonality of the 2 dimensions and the nature and assessment of the social self-concept.

  1. Benchmarking the Predictive Power of Ligand Efficiency Indices in QSAR.

    PubMed

    Cortes-Ciriano, Isidro

    2016-08-22

    Compound physicochemical properties favoring in vitro potency are not always correlated to desirable pharmacokinetic profiles. Therefore, using potency (i.e., IC50) as the main criterion to prioritize candidate drugs at early stage drug discovery campaigns has been questioned. Yet, the vast majority of the virtual screening models reported in the medicinal chemistry literature predict the biological activity of compounds by regressing in vitro potency on topological or physicochemical descriptors. Two studies published in this journal showed that higher predictive power on external molecules can be achieved by using ligand efficiency indices as the dependent variable instead of a metric of potency (IC50) or binding affinity (Ki). The present study aims at filling the shortage of a thorough assessment of the predictive power of ligand efficiency indices in QSAR. To this aim, the predictive power of 11 ligand efficiency indices has been benchmarked across four algorithms (Gradient Boosting Machines, Partial Least Squares, Random Forest, and Support Vector Machines), two descriptor types (Morgan fingerprints, and physicochemical descriptors), and 29 data sets collected from the literature and ChEMBL database. Ligand efficiency metrics led to the highest predictive power on external molecules irrespective of the descriptor type or algorithm used, with an R(2)test difference of ∼0.3 units and a this difference ∼0.4 units when modeling small data sets and a normalized RMSE decrease of >0.1 units in some cases. Polarity indices, such as SEI and NSEI, led to higher predictive power than metrics based on molecular size, i.e., BEI, NBEI, and LE. LELP, which comprises a polarity factor (cLogP) and a size parameter (LE) constantly led to the most predictive models, suggesting that these two properties convey a complementary predictive signal. Overall, this study suggests that using ligand efficiency indices as the dependent variable might be an efficient strategy to model

  2. Predicting Change in Postpartum Depression: An Individual Growth Curve Approach.

    ERIC Educational Resources Information Center

    Buchanan, Trey

    Recently, methodologists interested in examining problems associated with measuring change have suggested that developmental researchers should focus upon assessing change at both intra-individual and inter-individual levels. This study used an application of individual growth curve analysis to the problem of maternal postpartum depression.…

  3. On the uncertainty of individual prediction because of sampling predictors.

    PubMed

    Shen, Changyu; Li, Xiaochun

    2016-05-30

    Prediction of an outcome for a given unit based on prediction models built on a training sample plays a major role in many research areas. The uncertainty of the prediction is predominantly characterized by the subject sampling variation in current practice, where prediction models built on hypothetically re-sampled units yield variable predictions for the same unit of interest. It is almost always true that the predictors used to build prediction models are simply a subset of the entirety of factors related to the outcome. Following the frequentist principle, we can account for the variation because of hypothetically re-sampled predictors used to build the prediction models. This is particularly important in medicine where the prediction has important and sometime life-death consequences on a patient's health status. In this article, we discuss some rationale along this line in the context of medicine. We propose a simple approach to estimate the standard error of the prediction that accounts for the variation because of sampling both subjects and predictors under logistic and Cox regression models. A simulation study is presented to support our argument and demonstrate the performance of our method. The concept and method are applied to a real data set. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26712471

  4. On the uncertainty of individual prediction because of sampling predictors.

    PubMed

    Shen, Changyu; Li, Xiaochun

    2016-05-30

    Prediction of an outcome for a given unit based on prediction models built on a training sample plays a major role in many research areas. The uncertainty of the prediction is predominantly characterized by the subject sampling variation in current practice, where prediction models built on hypothetically re-sampled units yield variable predictions for the same unit of interest. It is almost always true that the predictors used to build prediction models are simply a subset of the entirety of factors related to the outcome. Following the frequentist principle, we can account for the variation because of hypothetically re-sampled predictors used to build the prediction models. This is particularly important in medicine where the prediction has important and sometime life-death consequences on a patient's health status. In this article, we discuss some rationale along this line in the context of medicine. We propose a simple approach to estimate the standard error of the prediction that accounts for the variation because of sampling both subjects and predictors under logistic and Cox regression models. A simulation study is presented to support our argument and demonstrate the performance of our method. The concept and method are applied to a real data set. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Individualized Course Completion Time Predictions: Development of Instruments and Techniques.

    ERIC Educational Resources Information Center

    Wagner, Harold; And Others

    Research was undertaken to develop a system for predicting completion time in a self-paced training course. The hypotheses were developed that: 1) course content-related instruments would be better predictors of completion time than general aptitude measures; and that 2) a linear predictive function would provide the best description of the…

  6. [Individual response to ionising radiation: What predictive assay(s) to choose?].

    PubMed

    Granzotto, Adeline; Joubert, Aurélie; Viau, Muriel; Devic, Clément; Maalouf, Mira; Thomas, Charles; Vogin, Guillaume; Malek, Karim; Colin, Catherine; Balosso, Jacques; Foray, Nicolas

    2011-02-01

    Individual response to ionizing radiation is an important information required to apply an efficient radiotherapy treatment against tumour and to avoid any adverse effects in normal tissues. In 1981, Fertil and Malaise have demonstrated that the post-irradiation local tumor control determined in vivo is correlated with clonogenic cell survival assessed in vitro. Furthermore, these authors have reminded the relevance of the concept of intrinsic radiosensitivity that is specific to each individual organ (Fertil and Malaise, 1981) [1]. To date, since clonogenicity assays are too time-consuming and do not provide any other molecular information, a plethora of research groups have attempted to determine the molecular bases of intrinsic radiosensitivity in order to propose reliable and faster predictive assays. To this aim, several approaches have been developed. Notably, the recent revolution in genomic and proteomic technologies is providing a considerable number of data but their link with radiosensitivity still remains to be elucidated. On another hand, the systematic screening of some candidate genes potentially involved in the radiation response is highlighting the complexity of the molecular and cellular mechanisms of DNA damage sensoring and signalling and shows that an abnormal radiation response is not necessarily due to the impairment of one single protein. Finally, more modest approaches consisting in focusing some specific functions of DNA repair seem to provide more reliable clues to predict over-acute reactions caused by radiotherapy. In this review, we endeavoured to analyse the contributions of these major approaches to predict human radiosensitivity. PMID:21333944

  7. Coherent Motion Sensitivity Predicts Individual Differences in Subtraction

    ERIC Educational Resources Information Center

    Boets, Bart; De Smedt, Bert; Ghesquiere, Pol

    2011-01-01

    Recent findings suggest deficits in coherent motion sensitivity, an index of visual dorsal stream functioning, in children with poor mathematical skills or dyscalculia, a specific learning disability in mathematics. We extended these data using a longitudinal design to unravel whether visual dorsal stream functioning is able to "predict"…

  8. Predicting Eighth-Grade Algebra Students with Individualized Education Programs

    ERIC Educational Resources Information Center

    Faulkner, Valerie N.; Crossland, Cathy L.; Stiff, Lee V.

    2013-01-01

    This study investigated the extent to which student performance and teacher perception of student performance affect placement in eighth-grade mathematics classes for students with disabilities. Authors used the Early Childhood Longitudinal Study--Kindergarten dataset to investigate how each of the following factors predicted placement in…

  9. Predicting Children's Depressive Symptoms from Community and Individual Risk Factors

    ERIC Educational Resources Information Center

    Dallaire, Danielle H.; Cole, David A.; Smith, Thomas M.; Ciesla, Jeffrey A.; LaGrange, Beth; Jacquez, Farrah M.; Pineda, Ashley Q.; Truss, Alanna E.; Folmer, Amy S.

    2008-01-01

    Community, demographic, familial, and personal risk factors of childhood depressive symptoms were examined from an ecological theoretical approach using hierarchical linear modeling. Individual-level data were collected from an ethnically diverse (73% African-American) community sample of 197 children and their parents; community-level data were…

  10. An improved methodology for individualized performance prediction of sleep-deprived individuals with the two-process model.

    PubMed

    Rajaraman, Srinivasan; Gribok, Andrei V; Wesensten, Nancy J; Balkin, Thomas J; Reifman, Jaques

    2009-10-01

    We present a method based on the two-process model of sleep regulation for developing individualized biomathematical models that predict performance impairment for individuals subjected to total sleep loss. This new method advances our previous work in two important ways. First, it enables model customization to start as soon as the first performance measurement from an individual becomes available. This was achieved by optimally combining the performance information obtained from the individual's performance measurements with a priori performance information using a Bayesian framework, while retaining the strategy of transforming the nonlinear optimization problem of finding the optimal estimates of the two-process model parameters into a series of linear optimization problems. Second, by taking advantage of the linear representation of the two-process model, this new method enables the analytical computation of statistically based measures of reliability for the model predictions in the form of prediction intervals. Two distinct data sets were used to evaluate the proposed method. Results using simulated data with superimposed white Gaussian noise showed that the new method yielded 50% to 90% improvement in parameter-estimate accuracy over the previous method. Moreover, the accuracy of the analytically computed prediction intervals was validated through Monte Carlo simulations. Results for subjects representing three sleep-loss phenotypes who participated in a laboratory study (82 h of total sleep loss) indicated that the proposed method yielded individualized predictions that were up to 43% more accurate than group-average prediction models and, on average, 10% more accurate than individualized predictions based on our previous method.

  11. Comparison of measured efficiencies of nine turbine designs with efficiencies predicted by two empirical methods

    NASA Technical Reports Server (NTRS)

    English, Robert E; Cavicchi, Richard H

    1951-01-01

    Empirical methods of Ainley and Kochendorfer and Nettles were used to predict performances of nine turbine designs. Measured and predicted performances were compared. Appropriate values of blade-loss parameter were determined for the method of Kochendorfer and Nettles. The measured design-point efficiencies were lower than predicted by as much as 0.09 (Ainley and 0.07 (Kochendorfer and Nettles). For the method of Kochendorfer and Nettles, appropriate values of blade-loss parameter ranged from 0.63 to 0.87 and the off-design performance was accurately predicted.

  12. Efficient Modelling and Prediction of Meshing Noise from Chain Drives

    NASA Astrophysics Data System (ADS)

    ZHENG, H.; WANG, Y. Y.; LIU, G. R.; LAM, K. Y.; QUEK, K. P.; ITO, T.; NOGUCHI, Y.

    2001-08-01

    This paper presents a practical approach for predicting the meshing noise due to the impact of chain rollers against the sprocket of chain drives. An acoustical model relating dynamic response of rollers and its induced sound pressure is developed based on the fact that the acoustic field is mainly created by oscillating rigid cylindrical rollers. Finite element techniques and numerical software codes are employed to model and simulate the acceleration response of each chain roller which is necessary for noise level prediction of a chain drive under varying operation conditions and different sprocket configurations. The predicted acoustic pressure levels of meshing noise are compared with the available experimental measurements. It is shown that the predictions are in reasonable agreement with the experiments and the approach enables designers to obtain required information on the noise level of a selected chain drive in a time- and cost-efficient manner.

  13. Predicting Individual Affect of Health Interventions to Reduce HPV Prevalence

    SciTech Connect

    Corley, Courtney D.; Mihalcea, Rada; Mikler, Armin R.; Sanfilippo, Antonio P.

    2011-04-01

    Recently, human papilloma virus has been implicated to cause several throat and oral cancers and hpv is established to cause most cervical cancers. A human papilloma virus vaccine has been proven successful to reduce infection incidence in FDA clinical trials and it is currently available in the United States. Current intervention policy targets adolescent females for vaccination; however, the expansion of suggested guidelines may extend to other age groups and males as well. This research takes a first step towards automatically predicting personal beliefs, regarding health intervention, on the spread of disease. Using linguistic or statistical approaches, sentiment analysis determines a texts affective content. Self-reported HPV vaccination beliefs published in web and social media are analyzed for affect polarity and leveraged as knowledge inputs to epidemic models. With this in mind, we have developed a discrete-time model to facilitate predicting impact on the reduction of HPV prevalence due to arbitrary age and gender targeted vaccination schemes.

  14. Predicting individual affect of health interventions to reduce HPV prevalence.

    PubMed

    Corley, Courtney D; Mihalcea, Rada; Mikler, Armin R; Sanfilippo, Antonio P

    2011-01-01

    Recently, human papilloma virus (HPV) has been implicated to cause several throat and oral cancers and HPV is established to cause most cervical cancers. A human papilloma virus vaccine has been proven successful to reduce infection incidence in FDA clinical trials, and it is currently available in the USA. Current intervention policy targets adolescent females for vaccination; however, the expansion of suggested guidelines may extend to other age groups and males as well. This research takes a first step toward automatically predicting personal beliefs, regarding health intervention, on the spread of disease. Using linguistic or statistical approaches, sentiment analysis determines a text's affective content. Self-reported HPV vaccination beliefs published in web and social media are analyzed for affect polarity and leveraged as knowledge inputs to epidemic models. With this in mind, we have developed a discrete-time model to facilitate predicting impact on the reduction of HPV prevalence due to arbitrary age- and gender-targeted vaccination schemes.

  15. Individual differences in individualism and collectivism predict ratings of virtual cities' liveability and environmental quality.

    PubMed

    Rubin, Mark; Morrison, Tessa

    2014-01-01

    The present research investigated individual differences in individualism and collectivism as predictors of people's reactions to cities. Psychology undergraduate students (N = 148) took virtual guided tours around historical cities. They then evaluated the cities' liveability and environmental quality and completed measures of individualism and collectivism. Mediation analyses showed that people who scored high in self-responsibility (individualism) rated the cities as more liveable because they perceived them to be richer and better resourced. In contrast, people who scored high in collectivism rated the cities as having a better environmental quality because they perceived them to (1) provide a greater potential for community and social life and (2) allow people to express themselves. These results indicate that people's evaluations of virtual cities are based on the degree to which certain aspects of the cities are perceived to be consistent with individualist and collectivist values. PMID:25302587

  16. Individual differences in individualism and collectivism predict ratings of virtual cities' liveability and environmental quality.

    PubMed

    Rubin, Mark; Morrison, Tessa

    2014-01-01

    The present research investigated individual differences in individualism and collectivism as predictors of people's reactions to cities. Psychology undergraduate students (N = 148) took virtual guided tours around historical cities. They then evaluated the cities' liveability and environmental quality and completed measures of individualism and collectivism. Mediation analyses showed that people who scored high in self-responsibility (individualism) rated the cities as more liveable because they perceived them to be richer and better resourced. In contrast, people who scored high in collectivism rated the cities as having a better environmental quality because they perceived them to (1) provide a greater potential for community and social life and (2) allow people to express themselves. These results indicate that people's evaluations of virtual cities are based on the degree to which certain aspects of the cities are perceived to be consistent with individualist and collectivist values.

  17. Face aftereffects predict individual differences in face recognition ability.

    PubMed

    Dennett, Hugh W; McKone, Elinor; Edwards, Mark; Susilo, Tirta

    2012-01-01

    Face aftereffects are widely studied on the assumption that they provide a useful tool for investigating face-space coding of identity. However, a long-standing issue concerns the extent to which face aftereffects originate in face-level processes as opposed to earlier stages of visual processing. For example, some recent studies failed to find atypical face aftereffects in individuals with clinically poor face recognition. We show that in individuals within the normal range of face recognition abilities, there is an association between face memory ability and a figural face aftereffect that is argued to reflect the steepness of broadband-opponent neural response functions in underlying face-space. We further show that this correlation arises from face-level processing, by reporting results of tests of nonface memory and nonface aftereffects. We conclude that face aftereffects can tap high-level face-space, and that face-space coding differs in quality between individuals and contributes to face recognition ability.

  18. An analytical method to predict efficiency of aircraft gearboxes

    NASA Technical Reports Server (NTRS)

    Anderson, N. E.; Loewenthal, S. H.; Black, J. D.

    1984-01-01

    A spur gear efficiency prediction method previously developed by the authors was extended to include power loss of planetary gearsets. A friction coefficient model was developed for MIL-L-7808 oil based on disc machine data. This combined with the recent capability of predicting losses in spur gears of nonstandard proportions allows the calculation of power loss for complete aircraft gearboxes that utilize spur gears. The method was applied to the T56/501 turboprop gearbox and compared with measured test data. Bearing losses were calculated with large scale computer programs. Breakdowns of the gearbox losses point out areas for possible improvement.

  19. Microstructure of frontoparietal connections predicts individual resistance to sleep deprivation.

    PubMed

    Cui, Jiaolong; Tkachenko, Olga; Gogel, Hannah; Kipman, Maia; Preer, Lily A; Weber, Mareen; Divatia, Shreya C; Demers, Lauren A; Olson, Elizabeth A; Buchholz, Jennifer L; Bark, John S; Rosso, Isabelle M; Rauch, Scott L; Killgore, William D S

    2015-02-01

    Sleep deprivation (SD) can degrade cognitive functioning, but growing evidence suggests that there are large individual differences in the vulnerability to this effect. Some evidence suggests that baseline differences in the responsiveness of a fronto-parietal attention system that is activated during working memory (WM) tasks may be associated with the ability to sustain vigilance during sleep deprivation. However, the neurocircuitry underlying this network remains virtually unexplored. In this study, we employed diffusion tensor imaging (DTI) to investigate the association between the microstructure of the axonal pathway connecting the frontal and parietal regions--i.e., the superior longitudinal fasciculus (SLF)--and individual resistance to SD. Thirty healthy participants (15 males) aged 20-43 years underwent functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) at rested wakefulness prior to a 28-hour period of SD. Task-related fronto-parietal fMRI activation clusters during a Sternberg WM Task were localized and used as seed regions for probabilistic fiber tractography. DTI metrics, including fractional anisotropy, mean diffusivity, axial and radial diffusivity were measured in the SLF. The psychomotor vigilance test (PVT) was used to evaluate resistance to SD. We found that activation in the left inferior parietal lobule (IPL) and dorsolateral prefrontal cortex (DLPFC) positively correlated with resistance. Higher fractional anisotropy of the left SLF comprising the primary axons connecting IPL and DLPFC was also associated with better resistance. These findings suggest that individual differences in resistance to SD are associated with the functional responsiveness of a fronto-parietal attention system and the microstructural properties of the axonal interconnections.

  20. Individual differences in holistic processing predict face recognition ability.

    PubMed

    Wang, Ruosi; Li, Jingguang; Fang, Huizhen; Tian, Moqian; Liu, Jia

    2012-02-01

    Why do some people recognize faces easily and others frequently make mistakes in recognizing faces? Classic behavioral work has shown that faces are processed in a distinctive holistic manner that is unlike the processing of objects. In the study reported here, we investigated whether individual differences in holistic face processing have a significant influence on face recognition. We found that the magnitude of face-specific recognition accuracy correlated with the extent to which participants processed faces holistically, as indexed by the composite-face effect and the whole-part effect. This association is due to face-specific processing in particular, not to a more general aspect of cognitive processing, such as general intelligence or global attention. This finding provides constraints on computational models of face recognition and may elucidate mechanisms underlying cognitive disorders, such as prosopagnosia and autism, that are associated with deficits in face recognition.

  1. Patient Characteristics Predicting Readmission Among Individuals Hospitalized for Heart Failure

    PubMed Central

    O'Connor, Melissa; Murtaugh, Christopher M.; Shah, Shivani; Barrón-Vaya, Yolanda; Bowles, Kathryn H.; Peng, Timothy R.; Zhu, Carolyn W.; Feldman, Penny H.

    2015-01-01

    Heart failure is difficult to manage and increasingly common with many individuals experiencing frequent hospitalizations. Little is known about patient factors consistently associated with hospital readmission. A literature review was conducted to identify heart failure patient characteristics, measured before discharge, that contribute to variation in hospital readmission rates. Database searches yielded 950 potential articles, of which 34 studies met inclusion criteria. Patient characteristics generally have a very modest effect on all-cause or heart failure–related readmission within 7 to 180 days of index hospital discharge. A range of cardiac diseases and other comorbidities only minimally increase readmission rates. No single patient characteristic stands out as a key contributor across multiple studies underscoring the challenge of developing successful interventions to reduce readmissions. Interventions may need to be general in design with the specific intervention depending on each patient's unique clinical profile. PMID:26180045

  2. A new protein structure representation for efficient protein function prediction.

    PubMed

    Maghawry, Huda A; Mostafa, Mostafa G M; Gharib, Tarek F

    2014-12-01

    One of the challenging problems in bioinformatics is the prediction of protein function. Protein function is the main key that can be used to classify different proteins. Protein function can be inferred experimentally with very small throughput or computationally with very high throughput. Computational methods are sequence based or structure based. Structure-based methods produce more accurate protein function prediction. In this article, we propose a new protein structure representation for efficient protein function prediction. The representation is based on three-dimensional patterns of protein residues. In the analysis, we used protein function based on enzyme activity through six mechanistically diverse enzyme superfamilies: amidohydrolase, crotonase, haloacid dehalogenase, isoprenoid synthase type I, and vicinal oxygen chelate. We applied three different classification methods, naïve Bayes, k-nearest neighbors, and random forest, to predict the enzyme superfamily of a given protein. The prediction accuracy using the proposed representation outperforms a recently introduced representation method that is based only on the distance patterns. The results show that the proposed representation achieved prediction accuracy up to 98%, with improvement of about 10% on average.

  3. Individual differences in impulsivity predict anticipatory eye movements.

    PubMed

    Cirilli, Laetitia; de Timary, Philippe; Lefèvre, Phillipe; Missal, Marcus

    2011-01-01

    Impulsivity is the tendency to act without forethought. It is a personality trait commonly used in the diagnosis of many psychiatric diseases. In clinical practice, impulsivity is estimated using written questionnaires. However, answers to questions might be subject to personal biases and misinterpretations. In order to alleviate this problem, eye movements could be used to study differences in decision processes related to impulsivity. Therefore, we investigated correlations between impulsivity scores obtained with a questionnaire in healthy subjects and characteristics of their anticipatory eye movements in a simple smooth pursuit task. Healthy subjects were asked to answer the UPPS questionnaire (Urgency Premeditation Perseverance and Sensation seeking Impulsive Behavior scale), which distinguishes four independent dimensions of impulsivity: Urgency, lack of Premeditation, lack of Perseverance, and Sensation seeking. The same subjects took part in an oculomotor task that consisted of pursuing a target that moved in a predictable direction. This task reliably evoked anticipatory saccades and smooth eye movements. We found that eye movement characteristics such as latency and velocity were significantly correlated with UPPS scores. The specific correlations between distinct UPPS factors and oculomotor anticipation parameters support the validity of the UPPS construct and corroborate neurobiological explanations for impulsivity. We suggest that the oculomotor approach of impulsivity put forth in the present study could help bridge the gap between psychiatry and physiology. PMID:22046334

  4. Individual variability in behavioral flexibility predicts sign-tracking tendency

    PubMed Central

    Nasser, Helen M.; Chen, Yu-Wei; Fiscella, Kimberly; Calu, Donna J.

    2015-01-01

    Sign-tracking rats show heightened sensitivity to food- and drug-associated cues, which serve as strong incentives for driving reward seeking. We hypothesized that this enhanced incentive drive is accompanied by an inflexibility when incentive value changes. To examine this we tested rats in Pavlovian outcome devaluation or second-order conditioning prior to the assessment of sign-tracking tendency. To assess behavioral flexibility we trained rats to associate a light with a food outcome. After the food was devalued by pairing with illness, we measured conditioned responding (CR) to the light during an outcome devaluation probe test. The level of CR during outcome devaluation probe test correlated with the rats' subsequent tracking tendency, with sign-tracking rats failing to suppress CR to the light after outcome devaluation. To assess Pavlovian incentive learning, we trained rats on first-order (CS+, CS−) and second-order (SOCS+, SOCS−) discriminations. After second-order conditioning, we measured CR to the second-order cues during a probe test. Second-order conditioning was observed across all rats regardless of tracking tendency. The behavioral inflexibility of sign-trackers has potential relevance for understanding individual variation in vulnerability to drug addiction. PMID:26578917

  5. Individual Differences in Personality Predict How People Look at Faces

    PubMed Central

    Perlman, Susan B.; Morris, James P.; Vander Wyk, Brent C.; Green, Steven R.; Doyle, Jaime L.; Pelphrey, Kevin A.

    2009-01-01

    Background Determining the ways in which personality traits interact with contextual determinants to shape social behavior remains an important area of empirical investigation. The specific personality trait of neuroticism has been related to characteristic negative emotionality and associated with heightened attention to negative, emotionally arousing environmental signals. However, the mechanisms by which this personality trait may shape social behavior remain largely unspecified. Methodology/Principal Findings We employed eye tracking to investigate the relationship between characteristics of visual scanpaths in response to emotional facial expressions and individual differences in personality. We discovered that the amount of time spent looking at the eyes of fearful faces was positively related to neuroticism. Conclusions/Significance This finding is discussed in relation to previous behavioral research relating personality to selective attention for trait-congruent emotional information, neuroimaging studies relating differences in personality to amygdala reactivity to socially relevant stimuli, and genetic studies suggesting linkages between the serotonin transporter gene and neuroticism. We conclude that personality may be related to interpersonal interaction by shaping aspects of social cognition as basic as eye contact. In this way, eye gaze represents a possible behavioral link in a complex relationship between genes, brain function, and personality. PMID:19543398

  6. Novel and efficient RNA secondary structure prediction using hierarchical folding.

    PubMed

    Jabbari, Hosna; Condon, Anne; Zhao, Shelly

    2008-03-01

    Algorithms for prediction of RNA secondary structure-the set of base pairs that form when an RNA molecule folds-are valuable to biologists who aim to understand RNA structure and function. Improving the accuracy and efficiency of prediction methods is an ongoing challenge, particularly for pseudoknotted secondary structures, in which base pairs overlap. This challenge is biologically important, since pseudoknotted structures play essential roles in functions of many RNA molecules, such as splicing and ribosomal frameshifting. State-of-the-art methods, which are based on free energy minimization, have high run-time complexity (typically Theta(n(5)) or worse), and can handle (minimize over) only limited types of pseudoknotted structures. We propose a new approach for prediction of pseudoknotted structures, motivated by the hypothesis that RNA structures fold hierarchically, with pseudoknot-free (non-overlapping) base pairs forming first, and pseudoknots forming later so as to minimize energy relative to the folded pseudoknot-free structure. Our HFold algorithm uses two-phase energy minimization to predict hierarchically formed secondary structures in O(n(3)) time, matching the complexity of the best algorithms for pseudoknot-free secondary structure prediction via energy minimization. Our algorithm can handle a wide range of biological structures, including kissing hairpins and nested kissing hairpins, which have previously required Theta(n(6)) time.

  7. TPV efficiency measurements and predictions for a closed cavity geometry

    SciTech Connect

    Gethers, C.K.; Ballinger, C.T.; Postlethwait, M.A.; DePoy, D.M.; Baldasaro, P.F.

    1997-05-01

    A thermophotovoltaic (TPV) efficiency measurement, within a closed cavity, is an integrated test which incorporates four fundamental parameters of TPV direct energy conversion. These are: (1) the TPV devices, (2) spectral control, (3) a radiation/photon source, and (4) closed cavity geometry effects. The overall efficiency of the TPV device is controlled by the TP cell performance, the spectral control characteristics, the radiator temperature and the geometric arrangement. Controlled efficiency measurements and predictions provide valuable feedback on all four. This paper describes and compares two computer codes developed to model 16, 1 cm{sup 2} TPV cells (in a 4 x 4 configuration) in a cavity geometry. The first code, subdivides the infrared spectrum into several bands and then numerically integrates over the spectrum to provide absorbed heat flux and cell electrical output performance predictions (assuming infinite parallel plates). The second code, utilizes a Monte Carlo Photon Transport code that tracks photons, from birth at the radiation source, until they either escape or are absorbed. Absorption depends upon energy dependent reflection probabilities assigned to every geometrical surface within the cavity. The model also has the capability of tallying above and below bandgap absorptions (as a function of location) and can support various radiator temperature profiles. The arrays were fabricated using 0.55 eV InGaAs cells with Si/SiO interference filters for spectral control and at steady state conditions, array efficiency was calculated as the ratio of the load matched power to its absorbed heat flux. Preliminary experimental results are also compared with predictions.

  8. TPV efficiency predictions and measurements for a closed cavity geometry

    SciTech Connect

    Gethers, C.K.; Ballinger, C.T.; Postlethwait, M.A.; DePoy, D.M.; Baldasaro, P.F.

    1997-05-01

    A thermophotovoltaic (TPV) efficiency measurement, within a closed cavity, is an integrated test which incorporates four fundamental parameters of TPV direct energy conversion. These are: (1) the TPV devices, (2) spectral control, (3) a radiation/photon source, and (4) closed cavity geometry affects. The overall efficiency of the TPV device is controlled by the TPV cell performance, the spectral control characteristics, the radiator temperature and the geometric arrangement. Controlled efficiency measurements and predictions provide valuable feedback on all four. This paper describes and compares two computer codes developed to model 16, 1 cm{sup 2} TPV cells (in a 4x4 configuration) in a cavity geometry. The first code subdivides the infrared spectrum into several bands and then numerically integrates over the spectrum to provide absorbed heat flux and cell performance predictions (assuming infinite parallel plates). The second utilizes a Monte Carlo Ray-Tracing code that tracks photons, from birth at the radiation source, until they either escape or are absorbed. Absorption depends upon energy dependent reflection probabilities assigned to every geometrical surface within the cavity. The model also has the capability of tallying above and below bandgap absorptions (as a function of location) and can support various radiator temperature profiles. The arrays are fabricated using 0.55 eV InGaAs cells with Si/SiO interference filters for spectral control and at steady state conditions, array efficiency was calculated as the ratio of the load matched power to its absorbed heat flux. Preliminary experimental results are also compared with predictions.

  9. Optimal Predictions in Everyday Cognition: The Wisdom of Individuals or Crowds?

    ERIC Educational Resources Information Center

    Mozer, Michael C.; Pashler, Harold; Homaei, Hadjar

    2008-01-01

    Griffiths and Tenenbaum (2006) asked individuals to make predictions about the duration or extent of everyday events (e.g., cake baking times), and reported that predictions were optimal, employing Bayesian inference based on veridical prior distributions. Although the predictions conformed strikingly to statistics of the world, they reflect…

  10. Predictive Models of Alcohol Use Based on Attitudes and Individual Values

    ERIC Educational Resources Information Center

    Del Castillo Rodríguez, José A. García; López-Sánchez, Carmen; Soler, M. Carmen Quiles; Del Castillo-López, Álvaro García; Pertusa, Mónica Gázquez; Campos, Juan Carlos Marzo; Inglés, Cándido J.

    2013-01-01

    Two predictive models are developed in this article: the first is designed to predict people' attitudes to alcoholic drinks, while the second sets out to predict the use of alcohol in relation to selected individual values. University students (N = 1,500) were recruited through stratified sampling based on sex and academic discipline. The…

  11. Ordinal classification for efficient plant stress prediction in hyperspectral data

    NASA Astrophysics Data System (ADS)

    Behmann, J.; Schmitter, P.; Steinrücken, J.; Plümer, L.

    2014-09-01

    Detection of crop stress from hyperspectral images is of high importance for breeding and precision crop protection. However, the continuous monitoring of stress in phenotyping facilities by hyperspectral imagers produces huge amounts of uninterpreted data. In order to derive a stress description from the images, interpreting algorithms with high prediction performance are required. Based on a static model, the local stress state of each pixel has to be predicted. Due to the low computational complexity, linear models are preferable. In this paper, we focus on drought-induced stress which is represented by discrete stages of ordinal order. We present and compare five methods which are able to derive stress levels from hyperspectral images: One-vs.-one Support Vector Machine (SVM), one-vs.-all SVM, Support Vector Regression (SVR), Support Vector Ordinal Regression (SVORIM) and Linear Ordinal SVM classification. The methods are applied on two data sets - a real world set of drought stress in single barley plants and a simulated data set. It is shown, that Linear Ordinal SVM is a powerful tool for applications which require high prediction performance under limited resources. It is significantly more efficient than the one-vs.-one SVM and even more efficient than the less accurate one-vs.-all SVM. Compared to the very compact SVORIM model, it represents the senescence process much more accurate.

  12. Individual but not fragile: individual differences in task control predict Stroop facilitation.

    PubMed

    Kalanthroff, E; Henik, A

    2013-06-01

    The Stroop effect is composed of interference and facilitation effects. The facilitation is less stable and thus many times is referred to as a "fragile effect". Here we suggest the facilitation effect is highly vulnerable to individual differences in control over the task conflict (between relevant color naming and irrelevant word reading in the Stroop task). We replicated previous findings of a significant correlation between stop-signal reaction time (SSRT) and Stroop interference, and also found a significant correlation between SSRT and the Stroop facilitation effect-participants with low inhibitory control (i.e., long SSRT) had no facilitation effect or even a reversed one. These results shed new light on the "fragile" facilitation effect and highlight the necessity of awareness of task conflict, especially in the Stroop task.

  13. Measurement and prediction of Energy Efficient Engine noise

    NASA Technical Reports Server (NTRS)

    Lavin, S. P.; Ho, P. Y.; Chamberlin, R.

    1984-01-01

    The NASA/GE Energy Efficient Engine (E3) static noise levels were measured in an acoustic arena on the Integrated Core and Low Spool Test System. These measured levels were scaled to the appropriate size to power four study aircraft and were projected to flight for evaluation of noise levels relative to FAR36, Stage III limits. As a result of these evaluations, it is predicted that the NASA/GE E3 engine with a wide spacing cut-on blade/vane ratio fan and a forced mixer nozzle can meet FAR36 Stage III limits with sufficient design margin.

  14. Predicting how individuals approach enrichment: regulatory focus in cotton-top tamarins (Sanguinus oedipus).

    PubMed

    Franks, Becca; Reiss, Diana; Cole, Patricia; Friedrich, Volney; Thompson, Nicole; Higgins, E Tory

    2013-01-01

    Evidence is mounting that personality is associated with health and well-being in humans and other animals. In a step towards increasing our understanding of this link, we applied regulatory focus theory, a motivational perspective from social psychology, to the behavior of zoo-housed cotton top tamarins. We tested whether regulatory focus "personality," that is stable differences in whether an individual is motivated by gains versus safety, would 1) produce individual differences in behavior and 2) predict how individuals interact with enrichment. First, we characterized individuals with respect to several key behaviors: eating in the open, hiding, and time spent near the front of the exhibit. The monkeys were consistent in their behavioral tendencies across the 6-month study, allowing regulatory focus classification. One monkey showed evidence of being a promotion-individual, that is, more motivated by gains than safety. One monkey showed evidence of being a prevention-individual, that is, more motivated by safety than gains. The other monkeys were stable in their behavior and showed evidence of being intermediate-individuals, that is, they favored neither gains nor safety. Using these characterizations, we predicted distinct patterns of individual-object interactions with enrichment. For example, we predicted that a promotion-individual (favoring gains over safety) would approach potential gains faster than a prevention-individual (favoring safety over gains). Counter-intuitively, however, we also predicted that a promotion-individual would approach non-gains slower than a prevention-individual concerned with safety. We found support for our predictions, which suggests that regulatory focus theory could be a useful tool for understanding how and why individuals interact with environmental enrichment.

  15. Prediction aluminum corrosion inhibitor efficiency using artificial neural network (ANN)

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Sh; Kalhor, E. G.; Nabavi, S. R.; Alamiparvin, L.; Pogaku, R.

    2016-06-01

    In this study, activity of some Schiff bases as aluminum corrosion inhibitor was investigated using artificial neural network (ANN). Hence, corrosion inhibition efficiency of Schiff bases (in any type) were gathered from different references. Then these molecules were drawn and optimized in Hyperchem software. Molecular descriptors generating and descriptors selection were fulfilled by Dragon software and principal component analysis (PCA) method, respectively. These structural descriptors along with environmental descriptors (ambient temperature, time of exposure, pH and the concentration of inhibitor) were used as input variables. Furthermore, aluminum corrosion inhibition efficiency was used as output variable. Experimental data were split into three sets: training set (for model building) and test set (for model validation) and simulation (for general model). Modeling was performed by Multiple linear regression (MLR) methods and artificial neural network (ANN). The results obtained in linear models showed poor correlation between experimental and theoretical data. However nonlinear model presented satisfactory results. Higher correlation coefficient of ANN (R > 0.9) revealed that ANN can be successfully applied for prediction of aluminum corrosion inhibitor efficiency of Schiff bases in different environmental conditions.

  16. Can the theory of planned behaviour predict the physical activity behaviour of individuals?

    PubMed

    Hobbs, Nicola; Dixon, Diane; Johnston, Marie; Howie, Kate

    2013-01-01

    The theory of planned behaviour (TPB) can identify cognitions that predict differences in behaviour between individuals. However, it is not clear whether the TPB can predict the behaviour of an individual person. This study employs a series of n-of-1 studies and time series analyses to examine the ability of the TPB to predict physical activity (PA) behaviours of six individuals. Six n-of-1 studies were conducted, in which TPB cognitions and up to three PA behaviours (walking, gym workout and a personally defined PA) were measured twice daily for six weeks. Walking was measured by pedometer step count, gym attendance by self-report with objective validation of gym entry and the personally defined PA behaviour by self-report. Intra-individual variability in TPB cognitions and PA behaviour was observed in all participants. The TPB showed variable predictive utility within individuals and across behaviours. The TPB predicted at least one PA behaviour for five participants but had no predictive utility for one participant. Thus, n-of-1 designs and time series analyses can be used to test theory in an individual.

  17. Can the theory of planned behaviour predict the physical activity behaviour of individuals?

    PubMed

    Hobbs, Nicola; Dixon, Diane; Johnston, Marie; Howie, Kate

    2013-01-01

    The theory of planned behaviour (TPB) can identify cognitions that predict differences in behaviour between individuals. However, it is not clear whether the TPB can predict the behaviour of an individual person. This study employs a series of n-of-1 studies and time series analyses to examine the ability of the TPB to predict physical activity (PA) behaviours of six individuals. Six n-of-1 studies were conducted, in which TPB cognitions and up to three PA behaviours (walking, gym workout and a personally defined PA) were measured twice daily for six weeks. Walking was measured by pedometer step count, gym attendance by self-report with objective validation of gym entry and the personally defined PA behaviour by self-report. Intra-individual variability in TPB cognitions and PA behaviour was observed in all participants. The TPB showed variable predictive utility within individuals and across behaviours. The TPB predicted at least one PA behaviour for five participants but had no predictive utility for one participant. Thus, n-of-1 designs and time series analyses can be used to test theory in an individual. PMID:22943555

  18. Striatal structure and function predict individual biases in learning to avoid pain

    PubMed Central

    Eldar, Eran; Hauser, Tobias U.; Dayan, Peter; Dolan, Raymond J.

    2016-01-01

    Pain is an elemental inducer of avoidance. Here, we demonstrate that people differ in how they learn to avoid pain, with some individuals refraining from actions that resulted in painful outcomes, whereas others favor actions that helped prevent pain. These individual biases were best explained by differences in learning from outcome prediction errors and were associated with distinct forms of striatal responses to painful outcomes. Specifically, striatal responses to pain were modulated in a manner consistent with an aversive prediction error in individuals who learned predominantly from pain, whereas in individuals who learned predominantly from success in preventing pain, modulation was consistent with an appetitive prediction error. In contrast, striatal responses to success in preventing pain were consistent with an appetitive prediction error in both groups. Furthermore, variation in striatal structure, encompassing the region where pain prediction errors were expressed, predicted participants’ predominant mode of learning, suggesting the observed learning biases may reflect stable individual traits. These results reveal functional and structural neural components underlying individual differences in avoidance learning, which may be important contributors to psychiatric disorders involving pathological harm avoidance behavior. PMID:27071092

  19. Predicting carcass composition and individual feed requirement in live cattle widely varying in body size.

    PubMed

    Perry, T C; Fox, D G

    1997-02-01

    A total of 192 feeder steers of five breed types and body sizes commonly found in the United States cattle population were fed high-energy diets to three endpoints (275-, 300-, and 360-kg carcass weights) to determine their carcass composition. Before slaughter, ultrasound was used to predict fat thickness, longissimus muscle area, and marbling. Individual steer data were used for developing prediction equations, which were validated with three independent data sets. These data were used to develop and validate equations to predict carcass composition and DM requirements for individuals fed in pens and varying in breed type, body weight and size, and ADG. Equations to predict carcass weight during growth accounted for 84, 83, and 88% of the variation in the three data sets with 0, 1, and 3% bias. An equation to predict percentage of carcass fat from fat thickness and equivalent shrunk weight accounted for 96% of the variation in the percentage of carcass fat. An equation to predict yield grade from longissimus muscle area per 100 kg, fat thickness, and equivalent shrunk weight accounted for 93% of the variation. Dry matter requirement predicted by the system for individuals accounted for 48% of the variation in actual DMI with a 3% overprediction bias. The equations allow the user to allocate feed to individual animals in group-feeding environments along with marketing cattle on an individual basis at optimum endpoints given cattle types, feeding costs, and market prices.

  20. Use of posterior predictive checks as an inferential tool for investigating individual heterogeneity in animal population vital rates

    PubMed Central

    Chambert, Thierry; Rotella, Jay J; Higgs, Megan D

    2014-01-01

    The investigation of individual heterogeneity in vital rates has recently received growing attention among population ecologists. Individual heterogeneity in wild animal populations has been accounted for and quantified by including individually varying effects in models for mark–recapture data, but the real need for underlying individual effects to account for observed levels of individual variation has recently been questioned by the work of Tuljapurkar et al. (Ecology Letters, 12, 93, 2009) on dynamic heterogeneity. Model-selection approaches based on information criteria or Bayes factors have been used to address this question. Here, we suggest that, in addition to model-selection, model-checking methods can provide additional important insights to tackle this issue, as they allow one to evaluate a model's misfit in terms of ecologically meaningful measures. Specifically, we propose the use of posterior predictive checks to explicitly assess discrepancies between a model and the data, and we explain how to incorporate model checking into the inferential process used to assess the practical implications of ignoring individual heterogeneity. Posterior predictive checking is a straightforward and flexible approach for performing model checks in a Bayesian framework that is based on comparisons of observed data to model-generated replications of the data, where parameter uncertainty is incorporated through use of the posterior distribution. If discrepancy measures are chosen carefully and are relevant to the scientific context, posterior predictive checks can provide important information allowing for more efficient model refinement. We illustrate this approach using analyses of vital rates with long-term mark–recapture data for Weddell seals and emphasize its utility for identifying shortfalls or successes of a model at representing a biological process or pattern of interest. We show how posterior predictive checks can be used to strengthen inferences in

  1. Individualized relapse prediction: personality measures and striatal and insular activity during reward-processing robustly predict relapse*

    PubMed Central

    Gowin, Joshua L.; Ball, Tali M.; Wittmann, Marc; Tapert, Susan F.; Paulus, Martin P.

    2015-01-01

    Background Nearly half of individuals with substance use disorders relapse in the year after treatment. A diagnostic tool to help clinicians make decisions regarding treatment does not exist for psychiatric conditions. Identifying individuals with high risk for relapse to substance use following abstinence has profound clinical consequences. This study aimed to develop neuroimaging as a robust tool to predict relapse. Methods 68 methamphetamine-dependent adults (15 female) were recruited from 28-day inpatient treatment. During treatment, participants completed a functional MRI scan that examined brain activation during reward processing. Patients were followed 1 year later to assess abstinence. We examined brain activation during reward processing between relapsing and abstaining individuals and employed three random forest prediction models (clinical and personality measures, neuroimaging measures, a combined model) to generate predictions for each participant regarding their relapse likelihood. Results 18 individuals relapsed. There were significant group by reward-size interactions for neural activation in the left insula and right striatum for rewards. Abstaining individuals showed increased activation for large, risky relative to small, safe rewards, whereas relapsing individuals failed to show differential activation between reward types. All three random forest models yielded good test characteristics such that a positive test for relapse yielded a likelihood ratio 2.63, whereas a negative test had a likelihood ratio of 0.48. Conclusions These findings suggest that neuroimaging can be developed in combination with other measures as an instrument to predict relapse, advancing tools providers can use to make decisions about individualized treatment of substance use disorders. PMID:25977206

  2. Prediction of Giant Thermoelectric Efficiency in Crystals with Interlaced Nanostructure.

    PubMed

    Puzyrev, Y S; Shen, X; Pantelides, S T

    2016-01-13

    We present a theoretical study of the thermoelectric efficiency of "interlaced crystals", recently discovered in hexagonal-CuInS2 nanoparticles. Interlaced crystals are I-III-VI2 or II-IV-V2 tetrahedrally bonded compounds. They have a perfect Bravais lattice in which the two cations have an infinite set of possible ordering patterns within the cation sublattice. The material comprises nanoscale interlaced domains and phases with corresponding boundaries. Here we employ density functional theory and large-scale molecular dynamics calculations based on model classical potentials to demonstrate that the phase and domain boundaries are effective phonon scatterers and greatly suppress thermal conductivity. However, the absence of both structural defects and strain in the interlaced material results in a minimal effect on electronic properties. We predict an increase of thermal resistivity of up to 2 orders of magnitude, which makes interlaced crystals an exceptional candidate for thermoelectric applications.

  3. Energy-efficient container handling using hybrid model predictive control

    NASA Astrophysics Data System (ADS)

    Xin, Jianbin; Negenborn, Rudy R.; Lodewijks, Gabriel

    2015-11-01

    The performance of container terminals needs to be improved to adapt the growth of containers while maintaining sustainability. This paper provides a methodology for determining the trajectory of three key interacting machines for carrying out the so-called bay handling task, involving transporting containers between a vessel and the stacking area in an automated container terminal. The behaviours of the interacting machines are modelled as a collection of interconnected hybrid systems. Hybrid model predictive control (MPC) is proposed to achieve optimal performance, balancing the handling capacity and energy consumption. The underlying control problem is hereby formulated as a mixed-integer linear programming problem. Simulation studies illustrate that a higher penalty on energy consumption indeed leads to improved sustainability using less energy. Moreover, simulations illustrate how the proposed energy-efficient hybrid MPC controller performs under different types of uncertainties.

  4. Brain ERP components predict which individuals progress to Alzheimer's disease and which do not.

    PubMed

    Chapman, Robert M; McCrary, John W; Gardner, Margaret N; Sandoval, Tiffany C; Guillily, Maria D; Reilly, Lindsey A; DeGrush, Elizabeth

    2011-10-01

    Predicting which individuals will progress to Alzheimer's disease (AD) is important in both clinical and research settings. We used brain Event-Related Potentials (ERPs) obtained in a perceptual/cognitive paradigm with various processing demands to predict which individual Mild Cognitive Impairment (MCI) subjects will develop AD versus which will not. ERP components, including P3, memory "storage" component, and other earlier and later components, were identified and measured by Principal Components Analysis. When measured for particular task conditions, a weighted set of eight ERP component_conditions performed well in discriminant analysis at predicting later AD progression with good accuracy, sensitivity, and specificity. The predictions for most individuals (79%) had high posterior probabilities and were accurate (88%). This method, supported by a cross-validation where the prediction accuracy was 70-78%, features the posterior probability for each individual as a method of determining the likelihood of progression to AD. Empirically obtained prediction accuracies rose to 94% when the computed posterior probabilities for individuals were 0.90 or higher (which was found for 40% of our MCI sample).

  5. Task-free MRI predicts individual differences in brain activity during task performance.

    PubMed

    Tavor, I; Parker Jones, O; Mars, R B; Smith, S M; Behrens, T E; Jbabdi, S

    2016-04-01

    When asked to perform the same task, different individuals exhibit markedly different patterns of brain activity. This variability is often attributed to volatile factors, such as task strategy or compliance. We propose that individual differences in brain responses are, to a large degree, inherent to the brain and can be predicted from task-independent measurements collected at rest. Using a large set of task conditions, spanning several behavioral domains, we train a simple model that relates task-independent measurements to task activity and evaluate the model by predicting task activation maps for unseen subjects using magnetic resonance imaging. Our model can accurately predict individual differences in brain activity and highlights a coupling between brain connectivity and function that can be captured at the level of individual subjects. PMID:27124457

  6. Task-free MRI predicts individual differences in brain activity during task performance.

    PubMed

    Tavor, I; Parker Jones, O; Mars, R B; Smith, S M; Behrens, T E; Jbabdi, S

    2016-04-01

    When asked to perform the same task, different individuals exhibit markedly different patterns of brain activity. This variability is often attributed to volatile factors, such as task strategy or compliance. We propose that individual differences in brain responses are, to a large degree, inherent to the brain and can be predicted from task-independent measurements collected at rest. Using a large set of task conditions, spanning several behavioral domains, we train a simple model that relates task-independent measurements to task activity and evaluate the model by predicting task activation maps for unseen subjects using magnetic resonance imaging. Our model can accurately predict individual differences in brain activity and highlights a coupling between brain connectivity and function that can be captured at the level of individual subjects.

  7. Individualized prediction of lung-function decline in chronic obstructive pulmonary disease

    PubMed Central

    Zafari, Zafar; Sin, Don D.; Postma, Dirkje S.; Löfdahl, Claes-Göran; Vonk, Judith; Bryan, Stirling; Lam, Stephen; Tammemagi, C. Martin; Khakban, Rahman; Man, S.F. Paul; Tashkin, Donald; Wise, Robert A.; Connett, John E.; McManus, Bruce; Ng, Raymond; Hollander, Zsuszanna; Sadatsafavi, Mohsen

    2016-01-01

    Background: The rate of lung-function decline in chronic obstructive pulmonary disease (COPD) varies substantially among individuals. We sought to develop and validate an individualized prediction model for forced expiratory volume at 1 second (FEV1) in current smokers with mild-to-moderate COPD. Methods: Using data from a large long-term clinical trial (the Lung Health Study), we derived mixed-effects regression models to predict future FEV1 values over 11 years according to clinical traits. We modelled heterogeneity by allowing regression coefficients to vary across individuals. Two independent cohorts with COPD were used for validating the equations. Results: We used data from 5594 patients (mean age 48.4 yr, 63% men, mean baseline FEV1 2.75 L) to create the individualized prediction equations. There was significant between-individual variability in the rate of FEV1 decline, with the interval for the annual rate of decline that contained 95% of individuals being −124 to −15 mL/yr for smokers and −83 to 15 mL/yr for sustained quitters. Clinical variables in the final model explained 88% of variation around follow-up FEV1. The C statistic for predicting severity grades was 0.90. Prediction equations performed robustly in the 2 external data sets. Interpretation: A substantial part of individual variation in FEV1 decline can be explained by easily measured clinical variables. The model developed in this work can be used for prediction of future lung health in patients with mild-to-moderate COPD. Trial registration: Lung Health Study — ClinicalTrials.gov, no. NCT00000568; Pan-Canadian Early Detection of Lung Cancer Study — ClinicalTrials.gov, no. NCT00751660 PMID:27486205

  8. Prediction of individual clinical scores in patients with Parkinson's disease using resting-state functional magnetic resonance imaging.

    PubMed

    Hou, YanBing; Luo, ChunYan; Yang, Jing; Ou, RuWei; Song, Wei; Wei, QianQian; Cao, Bei; Zhao, Bi; Wu, Ying; Shang, Hui-Fang; Gong, QiYong

    2016-07-15

    Neuroimaging holds the promise that it may one day aid the clinical assessment. However, the vast majority of studies using resting-state functional magnetic resonance imaging (fMRI) have reported average differences between Parkinson's disease (PD) patients and healthy controls, which do not permit inferences at the level of individuals. This study was to develop a model for the prediction of PD illness severity ratings from individual fMRI brain scan. The resting-state fMRI scans were obtained from 84 patients with PD and the Unified Parkinson's Disease Rating Scale-III (UPDRS-III) scores were obtained before scanning. The RVR method was used to predict clinical scores (UPDRS-III) from fMRI scans. The application of RVR to whole-brain resting-state fMRI data allowed prediction of UPDRS-III scores with statistically significant accuracy (correlation=0.35, P-value=0.001; mean sum of squares=222.17, P-value=0.002). This prediction was informed strongly by negative weight areas including prefrontal lobe and medial occipital lobe, and positive weight areas including medial parietal lobe. It was suggested that fMRI scans contained sufficient information about neurobiological change in patients with PD to permit accurate prediction about illness severity, on an individual subject basis. Our results provided preliminary evidence, as proof-of-concept, to support that fMRI might be possible to be a clinically useful quantitative assessment aid in PD at individual level. This may enable clinicians to target those uncooperative patients and machines to replace human for a more efficient use of health care resources. PMID:27288771

  9. Clinical Neurochemistry of Subarachnoid Hemorrhage: Toward Predicting Individual Outcomes via Biomarkers of Brain Energy Metabolism.

    PubMed

    Tholance, Yannick; Barcelos, Gleicy; Dailler, Frederic; Perret-Liaudet, Armand; Renaud, Bernard

    2015-12-16

    The functional outcome of patients with subarachnoid hemorrhage is difficult to predict at the individual level. The monitoring of brain energy metabolism has proven to be useful in improving the pathophysiological understanding of subarachnoid hemorrhage. Nonetheless, brain energy monitoring has not yet clearly been included in official guidelines for the management of subarachnoid hemorrhage patients, likely because previous studies compared only biological data between two groups of patients (unfavorable vs favorable outcomes) and did not determine decision thresholds that could be useful in clinical practice. Therefore, this Viewpoint discusses recent findings suggesting that monitoring biomarkers of brain energy metabolism at the level of individuals can be used to predict the outcomes of subarachnoid hemorrhage patients. Indeed, by taking into account specific neurochemical patterns obtained by local or global monitoring of brain energy metabolism, it may become possible to predict routinely, and with sufficient sensitivity and specificity, the individual outcomes of subarachnoid hemorrhage patients. Moreover, combining both local and global monitoring improves the overall performance of individual outcome prediction. Such a combined neurochemical monitoring approach may become, after prospective clinical validation, an important component in the management of subarachnoid hemorrhage patients to adapt individualized therapeutic interventions. PMID:26595414

  10. Changes in predicted muscle coordination with subject-specific muscle parameters for individuals after stroke.

    PubMed

    Knarr, Brian A; Reisman, Darcy S; Binder-Macleod, Stuart A; Higginson, Jill S

    2014-01-01

    Muscle weakness is commonly seen in individuals after stroke, characterized by lower forces during a maximal volitional contraction. Accurate quantification of muscle weakness is paramount when evaluating individual performance and response to after stroke rehabilitation. The objective of this study was to examine the effect of subject-specific muscle force and activation deficits on predicted muscle coordination when using musculoskeletal models for individuals after stroke. Maximum force generating ability and central activation ratio of the paretic plantar flexors, dorsiflexors, and quadriceps muscle groups were obtained using burst superimposition for four individuals after stroke with a range of walking speeds. Two models were created per subject: one with generic and one with subject-specific activation and maximum isometric force parameters. The inclusion of subject-specific muscle data resulted in changes in the model-predicted muscle forces and activations which agree with previously reported compensation patterns and match more closely the timing of electromyography for the plantar flexor and hamstring muscles. This was the first study to create musculoskeletal simulations of individuals after stroke with subject-specific muscle force and activation data. The results of this study suggest that subject-specific muscle force and activation data enhance the ability of musculoskeletal simulations to accurately predict muscle coordination in individuals after stroke.

  11. Prediction Formulas for Individual Opioid Analgesic Requirements Based on Genetic Polymorphism Analyses

    PubMed Central

    Yoshida, Kaori; Nishizawa, Daisuke; Ichinomiya, Takashi; Ichinohe, Tatsuya; Hayashida, Masakazu; Fukuda, Ken-ichi; Ikeda, Kazutaka

    2015-01-01

    Background The analgesic efficacy of opioids is well known to vary widely among individuals, and various factors related to individual differences in opioid sensitivity have been identified. However, a prediction model to calculate appropriate opioid analgesic requirements has not yet been established. The present study sought to construct prediction formulas for individual opioid analgesic requirements based on genetic polymorphisms and clinical data from patients who underwent cosmetic orthognathic surgery and validate the utility of the prediction formulas in patients who underwent major open abdominal surgery. Methods To construct the prediction formulas, we performed multiple linear regression analyses using data from subjects who underwent cosmetic orthognathic surgery. The dependent variable was 24-h postoperative or perioperative fentanyl use, and the independent variables were age, gender, height, weight, pain perception latencies (PPL), and genotype data of five single-nucleotide polymorphisms (SNPs). To examine the utility of the prediction formulas, we performed simple linear regression analyses using subjects who underwent major open abdominal surgery. Actual 24-h postoperative or perioperative analgesic use and the predicted values that were calculated using the multiple regression equations were incorporated as dependent and independent variables, respectively. Results Multiple linear regression analyses showed that the four SNPs, PPL, and weight were retained as independent predictors of 24-h postoperative fentanyl use (R2 = 0.145, P = 5.66 × 10-10) and the two SNPs and weight were retained as independent predictors of perioperative fentanyl use (R2 = 0.185, P = 1.99 × 10-15). Simple linear regression analyses showed that the predicted values were retained as an independent predictor of actual 24-h postoperative analgesic use (R2 = 0.033, P = 0.030) and perioperative analgesic use (R2 = 0.100, P = 1.09 × 10-4), respectively. Conclusions We

  12. Enhancing Arithmetic and Word-Problem Solving Skills Efficiently by Individualized Computer-Assisted Practice

    ERIC Educational Resources Information Center

    Schoppek, Wolfgang; Tulis, Maria

    2010-01-01

    The fluency of basic arithmetical operations is a precondition for mathematical problem solving. However, the training of skills plays a minor role in contemporary mathematics instruction. The authors proposed individualization of practice as a means to improve its efficiency, so that the time spent with the training of skills is minimized. As a…

  13. Efficiency under record performance demands: exertion control--an individual difference variable?

    PubMed

    Heckhausen, H; Strang, H

    1988-09-01

    Semiprofessional players ran basketball circuits under either normal or record performance demands. Lactate concentration and heart rate were measured as indexes of exertion. Number of dribbling errors, attempted shots, hits, and hit rate served as measures of performance and efficiency. Several individual difference measures were taken in order to identify those athletes who were capable of moderating the extent of exertion and of preserving their performance from impairment. The indexes of exertion rose sharply from normal to record trials. Correspondingly, the numbers of dribbling errors and of shots increased while the hit rate declined. However, there were considerable individual differences in restraining exertion and preserving efficiency--both indexes of exertion control. Neither achievement motive scores nor questionnaire items that ask for self-knowledge about exertion control could account for these differences. However, individuals capable of exertion control could be discriminated by an action-control scale that asks about postdecisional implementation of action steps (Kuhl, 1985).

  14. Content and activity of human liver microsomal protein and prediction of individual hepatic clearance in vivo

    PubMed Central

    Zhang, Haifeng; Gao, Na; Tian, Xin; Liu, Tingting; Fang, Yan; Zhou, Jun; Wen, Qiang; Xu, Binbin; Qi, Bing; Gao, Jie; Li, Hongmeng; Jia, Linjing; Qiao, Hailing

    2015-01-01

    The lack of information concerning individual variation in content and activity of human liver microsomal protein is one of the most important obstacles for designing personalized medicines. We demonstrated that the mean value of microsomal protein per gram of liver (MPPGL) was 39.46 mg/g in 128 human livers and up to 19-fold individual variations existed. Meanwhile, the metabolic activities of 10 cytochrome P450 (CYPs) were detected in microsomes and liver tissues, respectively, which showed huge individual variations (200-fold). Compared with microsomes, the activities of liver tissues were much suitable to express the individual variations of CYP activities. Furthermore, individual variations in the in vivo clearance of tolbutamide were successfully predicted with the individual parameter values. In conclusion, we offer the values for MPPGL contents in normal liver tissues and build a new method to assess the in vitro CYP activities. In addition, large individual variations exist in predicted hepatic clearance of tolbutamide. These findings provide important physiological parameters for physiologically-based pharmacokinetics models and thus, establish a solid foundation for future development of personalized medicines. PMID:26635233

  15. Content and activity of human liver microsomal protein and prediction of individual hepatic clearance in vivo.

    PubMed

    Zhang, Haifeng; Gao, Na; Tian, Xin; Liu, Tingting; Fang, Yan; Zhou, Jun; Wen, Qiang; Xu, Binbin; Qi, Bing; Gao, Jie; Li, Hongmeng; Jia, Linjing; Qiao, Hailing

    2015-12-04

    The lack of information concerning individual variation in content and activity of human liver microsomal protein is one of the most important obstacles for designing personalized medicines. We demonstrated that the mean value of microsomal protein per gram of liver (MPPGL) was 39.46 mg/g in 128 human livers and up to 19-fold individual variations existed. Meanwhile, the metabolic activities of 10 cytochrome P450 (CYPs) were detected in microsomes and liver tissues, respectively, which showed huge individual variations (200-fold). Compared with microsomes, the activities of liver tissues were much suitable to express the individual variations of CYP activities. Furthermore, individual variations in the in vivo clearance of tolbutamide were successfully predicted with the individual parameter values. In conclusion, we offer the values for MPPGL contents in normal liver tissues and build a new method to assess the in vitro CYP activities. In addition, large individual variations exist in predicted hepatic clearance of tolbutamide. These findings provide important physiological parameters for physiologically-based pharmacokinetics models and thus, establish a solid foundation for future development of personalized medicines.

  16. On-Line Individual Differences in Statistical Learning Predict Language Processing

    PubMed Central

    Misyak, Jennifer B.; Christiansen, Morten H.; Tomblin, J. Bruce

    2010-01-01

    Considerable individual differences in language ability exist among normally developing children and adults. Whereas past research have attributed such differences to variations in verbal working memory or experience with language, we test the hypothesis that individual differences in statistical learning may be associated with differential language performance. We employ a novel paradigm for studying statistical learning on-line, combining a serial-reaction time task with artificial grammar learning. This task offers insights into both the timecourse of and individual differences in statistical learning. Experiment 1 charts the micro-level trajectory for statistical learning of nonadjacent dependencies and provides an on-line index of individual differences therein. In Experiment 2, these differences are then shown to predict variations in participants’ on-line processing of long-distance dependencies involving center-embedded relative clauses. The findings suggest that individual differences in the ability to learn from experience through statistical learning may contribute to variations in linguistic performance. PMID:21833201

  17. Predicting Teen Motherhood and Teen Fatherhood: Individual Characteristics and Peer Affiliations.

    ERIC Educational Resources Information Center

    Xie, Hongling; Cairns, Beverley D.; Cairns, Robert B.

    2001-01-01

    Examined 475 adolescents from Grade 7 through early adulthood to identify antecedents and pathways of teen parenthood. Found that teen fatherhood and motherhood were predicted by individual and peer configurations such as a combination of high aggression, low academic competence, low popularity, and low family SES. Peer characteristics, race, and…

  18. Predicting Achievement in Mathematics in Adolescent Students: The Role of Individual and Social Factors

    ERIC Educational Resources Information Center

    Levpuscek, Melita Puklek; Zupancic, Maja; Socan, Gregor

    2013-01-01

    The study examined individual factors and social factors that influence adolescent students' achievement in mathematics. The predictive model suggested direct positive effects of student intelligence, self-rated openness and parental education on achievement in mathematics, whereas direct effects of extraversion on measures of achievement…

  19. Cognitive trait anxiety, situational stress, and mental effort predict shifting efficiency: Implications for attentional control theory.

    PubMed

    Edwards, Elizabeth J; Edwards, Mark S; Lyvers, Michael

    2015-06-01

    Attentional control theory (ACT) predicts that trait anxiety and situational stress interact to impair performance on tasks that involve attentional shifting. The theory suggests that anxious individuals recruit additional effort to prevent shortfalls in performance effectiveness (accuracy), with deficits becoming evident in processing efficiency (the relationship between accuracy and time taken to perform the task). These assumptions, however, have not been systematically tested. The relationship between cognitive trait anxiety, situational stress, and mental effort in a shifting task (Wisconsin Card Sorting Task) was investigated in 90 participants. Cognitive trait anxiety was operationalized using questionnaire scores, situational stress was manipulated through ego threat instructions, and mental effort was measured using a visual analogue scale. Dependent variables were performance effectiveness (an inverse proportion of perseverative errors) and processing efficiency (an inverse proportion of perseverative errors divided by response time on perseverative error trials). The predictors were not associated with performance effectiveness; however, we observed a significant 3-way interaction on processing efficiency. At higher mental effort (+1 SD), higher cognitive trait anxiety was associated with poorer efficiency independently of situational stress, whereas at lower effort (-1 SD), this relationship was highly significant and most pronounced for those in the high-stress condition. These results are important because they provide the first systematic test of the relationship between trait anxiety, situational stress, and mental effort on shifting performance. The data are also consistent with the notion that effort moderates the relationship between anxiety and shifting efficiency, but not effectiveness.

  20. Making Predictions in a Changing World: The Benefits of Individual-Based Ecology

    PubMed Central

    Stillman, Richard A.; Railsback, Steven F.; Giske, Jarl; Berger, Uta; Grimm, Volker

    2014-01-01

    Ecologists urgently need a better ability to predict how environmental change affects biodiversity. We examine individual-based ecology (IBE), a research paradigm that promises better a predictive ability by using individual-based models (IBMs) to represent ecological dynamics as arising from how individuals interact with their environment and with each other. A key advantage of IBMs is that the basis for predictions—fitness maximization by individual organisms—is more general and reliable than the empirical relationships that other models depend on. Case studies illustrate the usefulness and predictive success of long-term IBE programs. The pioneering programs had three phases: conceptualization, implementation, and diversification. Continued validation of models runs throughout these phases. The breakthroughs that make IBE more productive include standards for describing and validating IBMs, improved and standardized theory for individual traits and behavior, software tools, and generalized instead of system-specific IBMs. We provide guidelines for pursuing IBE and a vision for future IBE research. PMID:26955076

  1. Predictive models of alcohol use based on attitudes and individual values.

    PubMed

    García del Castillo Rodríguez, José A; López-Sánchez, Carmen; Quiles Soler, M Carmen; García del Castillo-López, Alvaro; Gázquez Pertusa, Mónica; Marzo Campos, Juan Carlos; Inglés, Candido J

    2013-01-01

    Two predictive models are developed in this article: the first is designed to predict people's attitudes to alcoholic drinks, while the second sets out to predict the use of alcohol in relation to selected individual values. University students (N = 1,500) were recruited through stratified sampling based on sex and academic discipline. The questionnaire used obtained information on participants' alcohol use, attitudes and personal values. The results show that the attitudes model correctly classifies 76.3% of cases. Likewise, the model for level of alcohol use correctly classifies 82% of cases. According to our results, we can conclude that there are a series of individual values that influence drinking and attitudes to alcohol use, which therefore provides us with a potentially powerful instrument for developing preventive intervention programs.

  2. Predicting shifts in dynamics of cannibalistic field populations using individual-based models.

    PubMed

    Persson, Lennart; de Roos, André M; Bertolo, Andrea

    2004-12-01

    The occurrence of qualitative shifts in population dynamical regimes has long been the focus of population biologists. Nonlinear ecological models predict that these shifts in dynamical regimes may occur as a result of parameter shifts, but unambiguous empirical evidence is largely restricted to laboratory populations. We used an individual-based modelling approach to predict dynamical shifts in field fish populations where the capacity to cannibalize differed between species. Model-generated individual growth trajectories that reflect different population dynamics were confronted with empirically observed growth trajectories, showing that our ordering and quantitative estimates of the different cannibalistic species in terms of life-history characteristics led to correct qualitative predictions of their dynamics. PMID:15590600

  3. Best Linear Unbiased Prediction of Individual Polygenic Susceptibility to Sporadic Vascular Dementia.

    PubMed

    Lee, Chaeyoung

    2016-05-31

    Genetic factors of sporadic vascular dementia have been quite limitedly understood. Many underlying polygenes are suspected to contribute to susceptibility to sporadic vascular dementia as a typical complex disease although they have not been identified from genome-wide association studies. This study suggests a stochastic prediction of individual polygenetic susceptibility to sporadic vascular dementia using best linear unbiased prediction in a mixed model framework. The prediction shows a relative degree of individual genetic susceptibility to the disease that reflects its integrative polygenetic factors across the genome. The estimate should take into account heritability and the prevalence of sporadic vascular dementia to cope with the disease. This offers a model for application of a genetic blueprint for a complex disease to personalized preventive medicine. PMID:27258425

  4. Genetic programming as alternative for predicting development effort of individual software projects.

    PubMed

    Chavoya, Arturo; Lopez-Martin, Cuauhtemoc; Andalon-Garcia, Irma R; Meda-Campaña, M E

    2012-01-01

    Statistical and genetic programming techniques have been used to predict the software development effort of large software projects. In this paper, a genetic programming model was used for predicting the effort required in individually developed projects. Accuracy obtained from a genetic programming model was compared against one generated from the application of a statistical regression model. A sample of 219 projects developed by 71 practitioners was used for generating the two models, whereas another sample of 130 projects developed by 38 practitioners was used for validating them. The models used two kinds of lines of code as well as programming language experience as independent variables. Accuracy results from the model obtained with genetic programming suggest that it could be used to predict the software development effort of individual projects when these projects have been developed in a disciplined manner within a development-controlled environment.

  5. Genetic Programming as Alternative for Predicting Development Effort of Individual Software Projects

    PubMed Central

    Chavoya, Arturo; Lopez-Martin, Cuauhtemoc; Andalon-Garcia, Irma R.; Meda-Campaña, M. E.

    2012-01-01

    Statistical and genetic programming techniques have been used to predict the software development effort of large software projects. In this paper, a genetic programming model was used for predicting the effort required in individually developed projects. Accuracy obtained from a genetic programming model was compared against one generated from the application of a statistical regression model. A sample of 219 projects developed by 71 practitioners was used for generating the two models, whereas another sample of 130 projects developed by 38 practitioners was used for validating them. The models used two kinds of lines of code as well as programming language experience as independent variables. Accuracy results from the model obtained with genetic programming suggest that it could be used to predict the software development effort of individual projects when these projects have been developed in a disciplined manner within a development-controlled environment. PMID:23226305

  6. Driving Green: Toward the Prediction and Influence of Efficient Driving Behavior

    NASA Astrophysics Data System (ADS)

    Newsome, William D.

    Sub-optimal efficiency in activities involving the consumption of fossil fuels, such as driving, contribute to a miscellany of negative environmental, political, economic and social externalities. Demonstrations of the effectiveness of feedback interventions can be found in countless organizational settings, as can demonstrations of individual differences in sensitivity to feedback interventions. Mechanisms providing feedback to drivers about fuel economy are becoming standard equipment in most new vehicles, but vary considerably in their constitution. A keystone of Radical Behaviorism is the acknowledgement that verbal behavior appears to play a role in mediating apparent susceptibility to influence by contingencies of varying delay. In the current study, samples of verbal behavior (rules) were collected in the context of a feedback intervention to improve driving efficiency. In an analysis of differences in individual responsiveness to the feedback intervention, the rate of novel rules per week generated by drivers is revealed to account for a substantial proportion of the variability in relative efficiency gains across participants. The predictive utility of conceptual tools, such as the basic distinction among contingency-shaped and rule governed behavior, the elaboration of direct-acting and indirect-acting contingencies, and the psychological flexibility model, is bolstered by these findings.

  7. Left anterior cingulate activity predicts intra-individual reaction time variability in healthy adults.

    PubMed

    Johnson, Beth P; Pinar, Ari; Fornito, Alex; Nandam, L Sanjay; Hester, Robert; Bellgrove, Mark A

    2015-06-01

    Within-subject, or intra-individual, variability in reaction time (RT) is increasingly recognised as an important indicator of the efficiency of attentional control, yet there have been few investigations of the neural correlates of trial-to-trial RT variability in healthy adults. We sought to determine the neural correlates of intra-individual RT variability during a go/no-go response inhibition task in 27 healthy, male participants. We found that reduced trial-to-trial RT variability (i.e. greater response stability) was significantly associated with greater activation in the left pregenual anterior cingulate. These results support the role of the left anterior cingulate in the dynamic control of attention and efficient response selection. Greater understanding of intra-individual RT variability and top-down attentional control in healthy adults may help to inform disorders that impact executive/attentional control, such as attention deficit hyperactivity disorder and schizophrenia. PMID:25791710

  8. Personality predicts individual responsiveness to the risks of starvation and predation.

    PubMed

    Quinn, J L; Cole, E F; Bates, J; Payne, R W; Cresswell, W

    2012-05-22

    Theory suggests that individual personality is tightly linked to individual life histories and to environmental variation. The reactive-proactive axis, for example, is thought to reflect whether individuals prioritize productivity or survival, mutually exclusive options that can be caused by conflicts between foraging and anti-predation behaviour. Evidence for this trade-off hypothesis, however, is limited. Here, we tested experimentally whether exploration behaviour (EB), an assay of proactivity, could explain how great tits (Parus major) respond to changes in starvation and predation risk. Individuals were presented with two feeders, holding good or poor quality food, which interchanged between safe and dangerous positions 10 m apart, across two 24 h treatments. Starvation risk was assumed to be highest in the morning and lowest in the afternoon. The proportion of time spent feeding on good quality food (PTG) rather than poor quality food was repeatable within treatments, but individuals varied in how PTG changed with respect to predation- and starvation-risk across treatments. This individual plasticity variation in foraging behaviour was linked to EB, as predicted by the reactive-proactive axis, but only among individuals in dominant social classes. Our results support the trade-off hypothesis at the level of individuals in a wild population, and suggest that fine-scale temporal and spatial variation may play important roles in the evolution of personality. PMID:22179807

  9. Personality predicts individual responsiveness to the risks of starvation and predation

    PubMed Central

    Quinn, J. L.; Cole, E. F.; Bates, J.; Payne, R. W.; Cresswell, W.

    2012-01-01

    Theory suggests that individual personality is tightly linked to individual life histories and to environmental variation. The reactive–proactive axis, for example, is thought to reflect whether individuals prioritize productivity or survival, mutually exclusive options that can be caused by conflicts between foraging and anti-predation behaviour. Evidence for this trade-off hypothesis, however, is limited. Here, we tested experimentally whether exploration behaviour (EB), an assay of proactivity, could explain how great tits (Parus major) respond to changes in starvation and predation risk. Individuals were presented with two feeders, holding good or poor quality food, which interchanged between safe and dangerous positions 10 m apart, across two 24 h treatments. Starvation risk was assumed to be highest in the morning and lowest in the afternoon. The proportion of time spent feeding on good quality food (PTG) rather than poor quality food was repeatable within treatments, but individuals varied in how PTG changed with respect to predation- and starvation-risk across treatments. This individual plasticity variation in foraging behaviour was linked to EB, as predicted by the reactive–proactive axis, but only among individuals in dominant social classes. Our results support the trade-off hypothesis at the level of individuals in a wild population, and suggest that fine-scale temporal and spatial variation may play important roles in the evolution of personality. PMID:22179807

  10. PREDICTING INDIVIDUAL WELL-BEING THROUGH THE LANGUAGE OF SOCIAL MEDIA.

    PubMed

    Schwartz, H Andrew; Sap, Maarten; Kern, Margaret L; Eichstaedt, Johannes C; Kapelner, Adam; Agrawal, Megha; Blanco, Eduardo; Dziurzynski, Lukasz; Park, Gregory; Stillwell, David; Kosinski, Michal; Seligman, Martin E P; Ungar, Lyle H

    2016-01-01

    We present the task of predicting individual well-being, as measured by a life satisfaction scale, through the language people use on social media. Well-being, which encompasses much more than emotion and mood, is linked with good mental and physical health. The ability to quickly and accurately assess it can supplement multi-million dollar national surveys as well as promote whole body health. Through crowd-sourced ratings of tweets and Facebook status updates, we create message-level predictive models for multiple components of well-being. However, well-being is ultimately attributed to people, so we perform an additional evaluation at the user-level, finding that a multi-level cascaded model, using both message-level predictions and userlevel features, performs best and outperforms popular lexicon-based happiness models. Finally, we suggest that analyses of language go beyond prediction by identifying the language that characterizes well-being.

  11. PREDICTING INDIVIDUAL WELL-BEING THROUGH THE LANGUAGE OF SOCIAL MEDIA.

    PubMed

    Schwartz, H Andrew; Sap, Maarten; Kern, Margaret L; Eichstaedt, Johannes C; Kapelner, Adam; Agrawal, Megha; Blanco, Eduardo; Dziurzynski, Lukasz; Park, Gregory; Stillwell, David; Kosinski, Michal; Seligman, Martin E P; Ungar, Lyle H

    2016-01-01

    We present the task of predicting individual well-being, as measured by a life satisfaction scale, through the language people use on social media. Well-being, which encompasses much more than emotion and mood, is linked with good mental and physical health. The ability to quickly and accurately assess it can supplement multi-million dollar national surveys as well as promote whole body health. Through crowd-sourced ratings of tweets and Facebook status updates, we create message-level predictive models for multiple components of well-being. However, well-being is ultimately attributed to people, so we perform an additional evaluation at the user-level, finding that a multi-level cascaded model, using both message-level predictions and userlevel features, performs best and outperforms popular lexicon-based happiness models. Finally, we suggest that analyses of language go beyond prediction by identifying the language that characterizes well-being. PMID:26776214

  12. Individual preparedness and mitigation actions for a predicted earthquake in Istanbul.

    PubMed

    Tekeli-Yeşil, Sıdıka; Dedeoğlu, Necati; Tanner, Marcel; Braun-Fahrlaender, Charlotte; Obrist, Birgit

    2010-10-01

    This study investigated the process of taking action to mitigate damage and prepare for an earthquake at the individual level. Its specific aim was to identify the factors that promote or inhibit individuals in this process. The study was conducted in Istanbul, Turkey--where an earthquake is expected soon--in May and June 2006 using qualitative methods. Within our conceptual framework, three different patterns emerged among the study subjects. Outcome expectancy, helplessness, a low socioeconomic level, a culture of negligence, a lack of trust, onset time/poor predictability, and normalisation bias inhibit individuals in this process, while location, direct personal experience, a higher education level, and social interaction promote them. Drawing on these findings, the paper details key points for better disaster communication, including whom to mobilise to reach target populations, such as individuals with direct earthquake experience and women.

  13. Combining information from ancestors and personal experiences to predict individual differences in developmental trajectories.

    PubMed

    Stamps, Judy A; Krishnan, V V

    2014-11-01

    A persistent question in biology is how information from ancestors combines with personal experiences over the lifetime to affect the developmental trajectories of phenotypic traits. We address this question by modeling individual differences in behavioral developmental trajectories on the basis of two assumptions: (1) differences among individuals in the behavior expressed at birth or hatching are based on information from their ancestors (via genes, epigenes, and prenatal maternal effects), and (2) information from ancestors is combined with information from personal experiences over ontogeny via Bayesian updating. The model predicts relationships between the means and the variability of the behavior expressed by neonates and the subsequent developmental trajectories of their behavior when every individual is reared under the same environmental conditions. Several predictions of the model are supported by data from previous studies of behavioral development, for example, that the temporal stability of personality will increase with age and that the intercepts and slopes of developmental trajectories for boldness will be negatively correlated across individuals or genotypes when subjects are raised in safe environments. We describe how other specific predictions of the model can be used to test the hypothesis that information from ancestors and information from personal experiences are combined via nonadditive, Bayesian-like processes. PMID:25325748

  14. Doing It Your Way: How Individual Movement Styles Affect Action Prediction

    PubMed Central

    Koul, Atesh; Ansuini, Caterina; Becchio, Cristina

    2016-01-01

    Individuals show significant variations in performing a motor act. Previous studies in the action observation literature have largely ignored this ubiquitous, if often unwanted, characteristic of motor performance, assuming movement patterns to be highly similar across repetitions and individuals. In the present study, we examined the possibility that individual variations in motor style directly influence the ability to understand and predict others’ actions. To this end, we first recorded grasping movements performed with different intents and used a two-step cluster analysis to identify quantitatively ‘clusters’ of movements performed with similar movement styles (Experiment 1). Next, using videos of the same movements, we proceeded to examine the influence of these styles on the ability to judge intention from action observation (Experiments 2 and 3). We found that motor styles directly influenced observers’ ability to ‘read’ others’ intention, with some styles always being less ‘readable’ than others. These results provide experimental support for the significance of motor variability for action prediction, suggesting that the ability to predict what another person is likely to do next directly depends on her individual movement style. PMID:27780259

  15. Combining information from ancestors and personal experiences to predict individual differences in developmental trajectories.

    PubMed

    Stamps, Judy A; Krishnan, V V

    2014-11-01

    A persistent question in biology is how information from ancestors combines with personal experiences over the lifetime to affect the developmental trajectories of phenotypic traits. We address this question by modeling individual differences in behavioral developmental trajectories on the basis of two assumptions: (1) differences among individuals in the behavior expressed at birth or hatching are based on information from their ancestors (via genes, epigenes, and prenatal maternal effects), and (2) information from ancestors is combined with information from personal experiences over ontogeny via Bayesian updating. The model predicts relationships between the means and the variability of the behavior expressed by neonates and the subsequent developmental trajectories of their behavior when every individual is reared under the same environmental conditions. Several predictions of the model are supported by data from previous studies of behavioral development, for example, that the temporal stability of personality will increase with age and that the intercepts and slopes of developmental trajectories for boldness will be negatively correlated across individuals or genotypes when subjects are raised in safe environments. We describe how other specific predictions of the model can be used to test the hypothesis that information from ancestors and information from personal experiences are combined via nonadditive, Bayesian-like processes.

  16. Factors predicting individual emergency preparedness: a multi-state analysis of 2006 BRFSS data.

    PubMed

    Ablah, Elizabeth; Konda, Kurt; Kelley, Crystal L

    2009-09-01

    Disasters pose a very real threat to every individual in the United States. One way to mitigate the threat of disasters is through personal preparedness, yet numerous studies indicate that individual Americans are not prepared for a disaster. This study attempted to identify the factors most likely to predict individual disaster preparedness. We used 2006 Behavioral Risk Factor Surveillance System (BRFSS) data from the 5 states that included the optional general preparedness module. Respondents were defined as being "prepared" if they were deficient in no more than 1 of the 6 actionable preparedness measures included on the BRFSS. Analyses were conducted comparing preparedness rates based on medical and demographic factors. Using logistic regression, a predictive model was constructed to identify which factors most strongly predicted an individual's likelihood of being prepared. Although 78% of respondents reported feeling prepared for a disaster, just 45% of respondents were actually prepared by objective measures. Factors predicting an increased likelihood of preparedness included feeling "well prepared" (OR 9.417), having a disability or health condition requiring special equipment (OR 1.298), being 55 to 64 years old (OR 1.794), and having an annual income above $50,000 (OR 1.286). Among racial and ethnic minorities, an inability to afford medical care in the previous year (OR .581) was an important factor in predicting a decreased likelihood of being prepared. This study revealed a pervasive lack of disaster preparedness overall and a substantial gap between perceived and objective preparedness. Income and age were important predictors of disaster preparedness.

  17. Can the Foot Posture Index or their individual criteria predict dynamic plantar pressures?

    PubMed

    Sánchez-Rodríguez, Raquel; Martínez-Nova, Alfonso; Escamilla-Martínez, Elena; Pedrera-Zamorano, Juan Diego

    2012-07-01

    The Foot Posture Index (FPI) quantifies foot posture through the evaluation of six individual criteria. The objective of the present study was then to establish the plantar pressure differences between types of feet, and to study the capacity of the whole FPI value and the six individual criteria to predict the pattern of plantar pressures. In a sample of 400 healthy subjects (201 men and 199 women), the FPI was evaluated and plantar pressures were measured in 10 zones using the Footscan(®) platform. Five plantar pressures measurements were made for each foot, using for the study the mean of these measurements for each subject's left foot. The hallux and the lesser toes had lower pressure indices in highly supinated feet, with the values increasing progressively toward the highly pronated feet (p<0.001 and p=0.019 respectively). The fifth metatarsal head (MTH) values were greater in highly supinated feet, and decreased in the highly pronated feet (p<0.001). The FPI value predicts low variability of plantar pressures, mainly in the heel and midfoot, while the individual criteria predict higher variability in the forefoot. The talonavicular prominence and the calcaneal frontal plane position was the most influential criterion, explaining 8.5% of the hallux pressure and 11.1% of the fifth MTH pressure. Neither talar head palpation nor the supra and infra malleolar curvature predicted any of the plantar pressures variables. The FPI can distinguish three groups of feet--pronated, neutral, and supinated. Its individual criteria predict moderate or low plantar pressures variability, with the talonavicular prominence being the most influential criterion.

  18. Cortical Response Similarities Predict which Audiovisual Clips Individuals Viewed, but Are Unrelated to Clip Preference

    PubMed Central

    Bridwell, David A.; Roth, Cullen; Gupta, Cota Navin; Calhoun, Vince D.

    2015-01-01

    Cortical responses to complex natural stimuli can be isolated by examining the relationship between neural measures obtained while multiple individuals view the same stimuli. These inter-subject correlation’s (ISC’s) emerge from similarities in individual’s cortical response to the shared audiovisual inputs, which may be related to their emergent cognitive and perceptual experience. Within the present study, our goal is to examine the utility of using ISC’s for predicting which audiovisual clips individuals viewed, and to examine the relationship between neural responses to natural stimuli and subjective reports. The ability to predict which clips individuals viewed depends on the relationship of the EEG response across subjects and the nature in which this information is aggregated. We conceived of three approaches for aggregating responses, i.e. three assignment algorithms, which we evaluated in Experiment 1A. The aggregate correlations algorithm generated the highest assignment accuracy (70.83% chance = 33.33%) and was selected as the assignment algorithm for the larger sample of individuals and clips within Experiment 1B. The overall assignment accuracy was 33.46% within Experiment 1B (chance = 06.25%), with accuracies ranging from 52.9% (Silver Linings Playbook) to 11.75% (Seinfeld) within individual clips. ISC’s were significantly greater than zero for 15 out of 16 clips, and fluctuations within the delta frequency band (i.e. 0-4 Hz) primarily contributed to response similarities across subjects. Interestingly, there was insufficient evidence to indicate that individuals with greater similarities in clip preference demonstrate greater similarities in cortical responses, suggesting a lack of association between ISC and clip preference. Overall these results demonstrate the utility of using ISC’s for prediction, and further characterize the relationship between ISC magnitudes and subjective reports. PMID:26030422

  19. Using individual differences to predict job performance: correcting for direct and indirect restriction of range.

    PubMed

    Sjöberg, Sofia; Sjöberg, Anders; Näswall, Katharina; Sverke, Magnus

    2012-08-01

    The present study investigates the relationship between individual differences, indicated by personality (FFM) and general mental ability (GMA), and job performance applying two different methods of correction for range restriction. The results, derived by analyzing meta-analytic correlations, show that the more accurate method of correcting for indirect range restriction increased the operational validity of individual differences in predicting job performance and that this increase primarily was due to general mental ability being a stronger predictor than any of the personality traits. The estimates for single traits can be applied in practice to maximize prediction of job performance. Further, differences in the relative importance of general mental ability in relation to overall personality assessment methods was substantive and the estimates provided enables practitioners to perform a correct utility analysis of their overall selection procedure. PMID:22612634

  20. Ecological rationality or nested sets? Individual differences in cognitive processing predict Bayesian reasoning.

    PubMed

    Sirota, Miroslav; Juanchich, Marie; Hagmayer, York

    2014-02-01

    The presentation of a Bayesian inference problem in terms of natural frequencies rather than probabilities has been shown to enhance performance. The effect of individual differences in cognitive processing on Bayesian reasoning has rarely been studied, despite enabling us to test process-oriented variants of the two main accounts of the facilitative effect of natural frequencies: The ecological rationality account (ERA), which postulates an evolutionarily shaped ease of natural frequency automatic processing, and the nested sets account (NSA), which posits analytical processing of nested sets. In two experiments, we found that cognitive reflection abilities predicted normative performance equally well in tasks featuring whole and arbitrarily parsed objects (Experiment 1) and that cognitive abilities and thinking dispositions (analytical vs. intuitive) predicted performance with single-event probabilities, as well as natural frequencies (Experiment 2). Since these individual differences indicate that analytical processing improves Bayesian reasoning, our findings provide stronger support for the NSA than for the ERA.

  1. A network of amygdala connections predict individual differences in trait anxiety.

    PubMed

    Greening, Steven G; Mitchell, Derek G V

    2015-12-01

    In this study we demonstrate that the pattern of an amygdala-centric network contributes to individual differences in trait anxiety. Individual differences in trait anxiety were predicted using maximum likelihood estimates of amygdala structural connectivity to multiple brain targets derived from diffusion-tensor imaging (DTI) and probabilistic tractography on 72 participants. The prediction was performed using a stratified sixfold cross validation procedure using a regularized least square regression model. The analysis revealed a reliable network of regions predicting individual differences in trait anxiety. Higher trait anxiety was associated with stronger connections between the amygdala and dorsal anterior cingulate cortex, an area implicated in the generation of emotional reactions, and inferior temporal gyrus and paracentral lobule, areas associated with perceptual and sensory processing. In contrast, higher trait anxiety was associated with weaker connections between amygdala and regions implicated in extinction learning such as medial orbitofrontal cortex, and memory encoding and environmental context recognition, including posterior cingulate cortex and parahippocampal gyrus. Thus, trait anxiety is not only associated with reduced amygdala connectivity with prefrontal areas associated with emotion modulation, but also enhanced connectivity with sensory areas. This work provides novel anatomical insight into potential mechanisms behind information processing biases observed in disorders of emotion.

  2. Quantitative Prediction of Individual Psychopathology in Trauma Survivors Using Resting-State fMRI

    PubMed Central

    Gong, Qiyong; Li, Lingjiang; Du, Mingying; Pettersson-Yeo, William; Crossley, Nicolas; Yang, Xun; Li, Jing; Huang, Xiaoqi; Mechelli, Andrea

    2014-01-01

    Neuroimaging techniques hold the promise that they may one day aid the clinical assessment of individual psychiatric patients. However, the vast majority of studies published so far have been based on average differences between groups. This study employed a multivariate approach to examine the potential of resting-state functional magnetic resonance imaging (MRI) data for making accurate predictions about psychopathology in survivors of the 2008 Sichuan earthquake at an individual level. Resting-state functional MRI data was acquired for 121 survivors of the 2008 Sichuan earthquake each of whom was assessed for symptoms of post-traumatic stress disorder (PTSD) using the 17-item PTSD Checklist (PCL). Using a multivariate analytical method known as relevance vector regression (RVR), we examined the relationship between resting-state functional MRI data and symptom scores. We found that the use of RVR allowed quantitative prediction of clinical scores with statistically significant accuracy (correlation=0.32, P=0.006; mean squared error=176.88, P=0.001). Accurate prediction was based on functional activation in a number of prefrontal, parietal, and occipital regions. This is the first evidence that neuroimaging techniques may inform the clinical assessment of trauma-exposed individuals by providing an accurate and objective quantitative estimation of psychopathology. Furthermore, the significant contribution of parietal and occipital regions to such estimation challenges the traditional view of PTSD as a disorder specific to the fronto-limbic network. PMID:24064470

  3. Prediction of individual long-term outcomes in smoking cessation trials using frailty models.

    PubMed

    Li, Yimei; Wileyto, E Paul; Heitjan, Daniel F

    2011-12-01

    In smoking cessation clinical trials, subjects commonly receive treatment and report daily cigarette consumption over a period of several weeks. Although the outcome at the end of this period is an important indicator of treatment success, substantial uncertainty remains on how an individual's smoking behavior will evolve over time. Therefore it is of interest to predict long-term smoking cessation success based on short-term clinical observations. We develop a Bayesian method for prediction, based on a cure-mixture frailty model we proposed earlier, that describes the process of transition between abstinence and smoking. Specifically we propose a two-stage prediction algorithm that first uses importance sampling to generate subject-specific frailties from their posterior distributions conditional on the observed data, then samples predicted future smoking behavior trajectories from the estimated model parameters and sampled frailties. We apply the method to data from two randomized smoking cessation trials comparing bupropion to placebo. Comparisons of actual smoking status at one year with predictions from our model and from a variety of empirical methods suggest that our method gives excellent predictions.

  4. Internalizing and externalizing traits predict changes in sleep efficiency in emerging adulthood: an actigraphy study

    PubMed Central

    Yaugher, Ashley C.; Alexander, Gerianne M.

    2015-01-01

    Research on psychopathology and experimental studies of sleep restriction support a relationship between sleep disruption and both internalizing and externalizing disorders. The objective of the current study was to extend this research by examining sleep, impulsivity, antisocial personality traits, and internalizing traits in a university sample. Three hundred and eighty six individuals (161 males) between the ages of 18 and 27 years (M = 18.59, SD = 0.98) wore actigraphs for 7 days and completed established measures of disorder-linked personality traits and sleep quality (i.e., Personality Assessment Inventory (PAI), Triarchic Psychopathy Measure, Barratt Impulsiveness Scale-11, and the Pittsburgh Sleep Quality Index). As expected, sleep measures and questionnaire scores fell within the normal range of values and sex differences in sleep and personality were consistent with previous research results. Similar to findings in predominantly male forensic psychiatric settings, higher levels of impulsivity predicted poorer subjective sleep quality in both women and men. Consistent with well-established associations between depression and sleep, higher levels of depression in both sexes predicted poorer subjective sleep quality. Bidirectional analyses showed that better sleep efficiency decreases depression. Finally, moderation analyses showed that gender does have a primary role in sleep efficiency and marginal effects were found. The observed relations between sleep and personality traits in a typical university sample add to converging evidence of the relationship between sleep and psychopathology and may inform our understanding of the development of psychopathology in young adulthood. PMID:26500575

  5. Internalizing and externalizing traits predict changes in sleep efficiency in emerging adulthood: an actigraphy study.

    PubMed

    Yaugher, Ashley C; Alexander, Gerianne M

    2015-01-01

    Research on psychopathology and experimental studies of sleep restriction support a relationship between sleep disruption and both internalizing and externalizing disorders. The objective of the current study was to extend this research by examining sleep, impulsivity, antisocial personality traits, and internalizing traits in a university sample. Three hundred and eighty six individuals (161 males) between the ages of 18 and 27 years (M = 18.59, SD = 0.98) wore actigraphs for 7 days and completed established measures of disorder-linked personality traits and sleep quality (i.e., Personality Assessment Inventory (PAI), Triarchic Psychopathy Measure, Barratt Impulsiveness Scale-11, and the Pittsburgh Sleep Quality Index). As expected, sleep measures and questionnaire scores fell within the normal range of values and sex differences in sleep and personality were consistent with previous research results. Similar to findings in predominantly male forensic psychiatric settings, higher levels of impulsivity predicted poorer subjective sleep quality in both women and men. Consistent with well-established associations between depression and sleep, higher levels of depression in both sexes predicted poorer subjective sleep quality. Bidirectional analyses showed that better sleep efficiency decreases depression. Finally, moderation analyses showed that gender does have a primary role in sleep efficiency and marginal effects were found. The observed relations between sleep and personality traits in a typical university sample add to converging evidence of the relationship between sleep and psychopathology and may inform our understanding of the development of psychopathology in young adulthood.

  6. Internalizing and externalizing traits predict changes in sleep efficiency in emerging adulthood: an actigraphy study.

    PubMed

    Yaugher, Ashley C; Alexander, Gerianne M

    2015-01-01

    Research on psychopathology and experimental studies of sleep restriction support a relationship between sleep disruption and both internalizing and externalizing disorders. The objective of the current study was to extend this research by examining sleep, impulsivity, antisocial personality traits, and internalizing traits in a university sample. Three hundred and eighty six individuals (161 males) between the ages of 18 and 27 years (M = 18.59, SD = 0.98) wore actigraphs for 7 days and completed established measures of disorder-linked personality traits and sleep quality (i.e., Personality Assessment Inventory (PAI), Triarchic Psychopathy Measure, Barratt Impulsiveness Scale-11, and the Pittsburgh Sleep Quality Index). As expected, sleep measures and questionnaire scores fell within the normal range of values and sex differences in sleep and personality were consistent with previous research results. Similar to findings in predominantly male forensic psychiatric settings, higher levels of impulsivity predicted poorer subjective sleep quality in both women and men. Consistent with well-established associations between depression and sleep, higher levels of depression in both sexes predicted poorer subjective sleep quality. Bidirectional analyses showed that better sleep efficiency decreases depression. Finally, moderation analyses showed that gender does have a primary role in sleep efficiency and marginal effects were found. The observed relations between sleep and personality traits in a typical university sample add to converging evidence of the relationship between sleep and psychopathology and may inform our understanding of the development of psychopathology in young adulthood. PMID:26500575

  7. Prediction of individual response to antidepressants and antipsychotics: an integrated concept.

    PubMed

    Preskorn, Sheldon H

    2014-12-01

    In both clinical trials and daily practice, there can be substantial inter- and even intraindividual variability in response--whether beneficial or adverse--to antidepressants and antipsychotic medications. So far, no tools have become available to predict the outcome of these treatments in specific patients. This is because the causes of such variability are often not known, and when they are, there is no way of predicting the effects of their various potential combinations in an individual. Given this background, this paper presents a conceptual framework for understanding known factors and their combinations so that eventually clinicians can better predict what medication(s) to select and at what dose they can optimize the outcome for a given individual. This framework is flexible enough to be readily adaptable as new information becomes available. The causes of variation in patient response are grouped into four categories: (i) genetics; (ii) age; (iii) disease; and (iv) environment (internal). Four cases of increasing complexity are used to illustrate the applicability of this framework in a clinically relevant way In addition, this paper reviews tools that the clinician can use to assess for and quantify such inter- and intraindividual variability. With the information gained, treatment can be adjusted to compensate for such variability, in order to optimize outcome. Finally, the limitations of existing antidepressant and antipsychotic therapy and the way they reduce current ability to predict response is discussed.

  8. Efficient Prediction of Co-Complexed Proteins Based on Coevolution

    PubMed Central

    de Vienne, Damien M.; Azé, Jérôme

    2012-01-01

    The prediction of the network of protein-protein interactions (PPI) of an organism is crucial for the understanding of biological processes and for the development of new drugs. Machine learning methods have been successfully applied to the prediction of PPI in yeast by the integration of multiple direct and indirect biological data sources. However, experimental data are not available for most organisms. We propose here an ensemble machine learning approach for the prediction of PPI that depends solely on features independent from experimental data. We developed new estimators of the coevolution between proteins and combined them in an ensemble learning procedure. We applied this method to a dataset of known co-complexed proteins in Escherichia coli and compared it to previously published methods. We show that our method allows prediction of PPI with an unprecedented precision of 95.5% for the first 200 sorted pairs of proteins compared to 28.5% on the same dataset with the previous best method. A close inspection of the best predicted pairs allowed us to detect new or recently discovered interactions between chemotactic components, the flagellar apparatus and RNA polymerase complexes in E. coli. PMID:23152796

  9. Practical prediction model for the risk of 2-year mortality of individuals in the general population.

    PubMed

    Goldfarb-Rumyantzev, Alexander; Gautam, Shiva; Brown, Robert S

    2016-04-01

    This study proposed to validate a prediction model and risk-stratification tool of 2-year mortality rates of individuals in the general population suitable for office practice use. A risk indicator (R) derived from data in the literature was based on only 6 variables: to calculate R for an individual, starting with 0, for each year of age above 60, add 0.14; for a male, add 0.9; for diabetes mellitus, add 0.7; for albuminuria > 30 mg/g of creatinine, add 0.7; for stage ≥ 3 chronic kidney disease (CKD), add 0.9; for cardiovascular disease (CVD), add 1.4; or for both CKD and CVD, add 1.7. We developed a univariate logistic regression model predicting 2-year individual mortality rates. The National Health and Nutrition Examination Survey (NHANES) data set (1999-2004 with deaths through 2006) was used as the target for validation. These 12,515 subjects had a mean age of 48.9 ± 18.1 years, 48% males, 9.5% diabetes, 11.7% albuminuria, 6.8% CVD, 5.4% CKD, and 2.8% both CKD and CVD. Using the risk indicator R alone to predict mortality demonstrated good performance with area under the receiver operating characteristic (ROC) curve of 0.84. Dividing subjects into low-risk (R=0-1.0), low intermediate risk (R > 1.0-3.0), high intermediate risk (R > 3.0-5.0) or high-risk (R > 5.0) categories predicted 2-year mortality rates of 0.52%, 1.44%, 5.19% and 15.24%, respectively, by the prediction model compared with actual mortality rates of 0.29%, 2.48%, 5.13% and 13.40%, respectively. We have validated a model of risk stratification using easily identified clinical characteristics to predict 2-year mortality rates of individuals in the general population. The model demonstrated performance adequate for its potential use for clinical practice and research decisions.

  10. Predicting High Harmonic Ion Cyclotron Heating Efficiency in Tokamak Plasmas

    NASA Astrophysics Data System (ADS)

    Green, D. L.; Berry, L. A.; Chen, G.; Ryan, P. M.; Canik, J. M.; Jaeger, E. F.

    2011-09-01

    Observations of improved radio frequency (rf) heating efficiency in ITER relevant high-confinement (H-)mode plasmas on the National Spherical Tokamak Experiment are investigated by whole-device linear simulation. The steady-state rf electric field is calculated for various antenna spectra and the results examined for characteristics that correlate with observations of improved or reduced rf heating efficiency. We find that launching toroidal wave numbers that give fast-wave propagation in the scrape-off plasma excites large amplitude (˜kVm-1) coaxial standing modes between the confined plasma density pedestal and conducting vessel wall. Qualitative comparison with measurements of the stored plasma energy suggests that these modes are a probable cause of degraded heating efficiency.

  11. Predicting high harmonic ion cyclotron heating efficiency in Tokamak plasmas.

    PubMed

    Green, D L; Berry, L A; Chen, G; Ryan, P M; Canik, J M; Jaeger, E F

    2011-09-30

    Observations of improved radio frequency (rf) heating efficiency in ITER relevant high-confinement (H-)mode plasmas on the National Spherical Tokamak Experiment are investigated by whole-device linear simulation. The steady-state rf electric field is calculated for various antenna spectra and the results examined for characteristics that correlate with observations of improved or reduced rf heating efficiency. We find that launching toroidal wave numbers that give fast-wave propagation in the scrape-off plasma excites large amplitude (∼kV m(-1)) coaxial standing modes between the confined plasma density pedestal and conducting vessel wall. Qualitative comparison with measurements of the stored plasma energy suggests that these modes are a probable cause of degraded heating efficiency.

  12. Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control.

    PubMed

    Holsback, Luciane; Luppi, Pedro Alex Ramsey; Silva, Camile Sanches; Negrão, Gustavo Kremer; Conde, Gabriel; Gabriel, Hugo Vinícius; Balestrieri, João Vitor; Tomazella, Lucas

    2016-01-01

    The anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, used individually or in combination, was determined by the Fecal Egg Count Reduction (FECR) test and cultivation of larvae of anthelminthic-treated sheep grouped as follows: G1 (doramectin), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectin + fenbendazole), G5 (doramectin + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectin + nitroxynil + fenbendazole), G8 (untreated). In addition to individually used doramectin and fenbendazole, the helminths were also resistant to the combination of doramectin + fenbendazole; nitroxynil + fenbendazole; and doramectin + nitroxynil + fenbendazole, with their FECR rates ranging from 62-83%. The helminths showed possible nitroxynil-resistance, but had low resistance when the drug was administered in combination with doramectin. The evaluation of individual helminth species revealed that fenbendazole was fully effective against Cooperia; doramectin (G1), moderately effective against Haemonchus and insufficiently active against Cooperia; nitroxynil, effective against Haemonchus and insufficiently active against Cooperia. It was concluded from the results that herd nematodes are resistant to doramectin, fenbendazole, and nitroxynil, and that the combined use of the drugs not only fails to significantly improve the anthelmintic efficiency against Haemonchus and Cooperia, but is also cost-ineffective.

  13. Genome-Wide Prediction of Traits with Different Genetic Architecture Through Efficient Variable Selection

    PubMed Central

    Wimmer, Valentin; Lehermeier, Christina; Albrecht, Theresa; Auinger, Hans-Jürgen; Wang, Yu; Schön, Chris-Carolin

    2013-01-01

    In genome-based prediction there is considerable uncertainty about the statistical model and method required to maximize prediction accuracy. For traits influenced by a small number of quantitative trait loci (QTL), predictions are expected to benefit from methods performing variable selection [e.g., BayesB or the least absolute shrinkage and selection operator (LASSO)] compared to methods distributing effects across the genome [ridge regression best linear unbiased prediction (RR-BLUP)]. We investigate the assumptions underlying successful variable selection by combining computer simulations with large-scale experimental data sets from rice (Oryza sativa L.), wheat (Triticum aestivum L.), and Arabidopsis thaliana (L.). We demonstrate that variable selection can be successful when the number of phenotyped individuals is much larger than the number of causal mutations contributing to the trait. We show that the sample size required for efficient variable selection increases dramatically with decreasing trait heritabilities and increasing extent of linkage disequilibrium (LD). We contrast and discuss contradictory results from simulation and experimental studies with respect to superiority of variable selection methods over RR-BLUP. Our results demonstrate that due to long-range LD, medium heritabilities, and small sample sizes, superiority of variable selection methods cannot be expected in plant breeding populations even for traits like FRIGIDA gene expression in Arabidopsis and flowering time in rice, assumed to be influenced by a few major QTL. We extend our conclusions to the analysis of whole-genome sequence data and infer upper bounds for the number of causal mutations which can be identified by LASSO. Our results have major impact on the choice of statistical method needed to make credible inferences about genetic architecture and prediction accuracy of complex traits. PMID:23934883

  14. Human brain structure predicts individual differences in preconscious evaluation of facial dominance and trustworthiness

    PubMed Central

    Kanai, Ryota; Bahrami, Bahador; Rees, Geraint

    2015-01-01

    Social cues conveyed by the human face, such as eye gaze direction, are evaluated even before they are consciously perceived. While there is substantial individual variability in such evaluation, its neural basis is unknown. Here we asked whether individual differences in preconscious evaluation of social face traits were associated with local variability in brain structure. Adult human participants (n = 36) monocularly viewed faces varying in dominance and trustworthiness, which were suppressed from awareness by a dynamic noise pattern shown to the other eye. The time taken for faces to emerge from suppression and become visible (t2e) was used as a measure of potency in competing for visual awareness. Both dominant and untrustworthy faces resulted in slower t2e than neutral faces, with substantial individual variability in these effects. Individual differences in t2e were correlated with gray matter volume in right insula for dominant faces, and with gray matter volume in medial prefrontal cortex, right temporoparietal junction and bilateral fusiform face area for untrustworthy faces. Thus, individual differences in preconscious social processing can be predicted from local brain structure, and separable correlates for facial dominance and untrustworthiness suggest distinct mechanisms of preconscious processing. PMID:25193945

  15. Human brain structure predicts individual differences in preconscious evaluation of facial dominance and trustworthiness.

    PubMed

    Getov, Spas; Kanai, Ryota; Bahrami, Bahador; Rees, Geraint

    2015-05-01

    Social cues conveyed by the human face, such as eye gaze direction, are evaluated even before they are consciously perceived. While there is substantial individual variability in such evaluation, its neural basis is unknown. Here we asked whether individual differences in preconscious evaluation of social face traits were associated with local variability in brain structure. Adult human participants (n = 36) monocularly viewed faces varying in dominance and trustworthiness, which were suppressed from awareness by a dynamic noise pattern shown to the other eye. The time taken for faces to emerge from suppression and become visible (t2e) was used as a measure of potency in competing for visual awareness. Both dominant and untrustworthy faces resulted in slower t2e than neutral faces, with substantial individual variability in these effects. Individual differences in t2e were correlated with gray matter volume in right insula for dominant faces, and with gray matter volume in medial prefrontal cortex, right temporoparietal junction and bilateral fusiform face area for untrustworthy faces. Thus, individual differences in preconscious social processing can be predicted from local brain structure, and separable correlates for facial dominance and untrustworthiness suggest distinct mechanisms of preconscious processing.

  16. Human brain structure predicts individual differences in preconscious evaluation of facial dominance and trustworthiness.

    PubMed

    Getov, Spas; Kanai, Ryota; Bahrami, Bahador; Rees, Geraint

    2015-05-01

    Social cues conveyed by the human face, such as eye gaze direction, are evaluated even before they are consciously perceived. While there is substantial individual variability in such evaluation, its neural basis is unknown. Here we asked whether individual differences in preconscious evaluation of social face traits were associated with local variability in brain structure. Adult human participants (n = 36) monocularly viewed faces varying in dominance and trustworthiness, which were suppressed from awareness by a dynamic noise pattern shown to the other eye. The time taken for faces to emerge from suppression and become visible (t2e) was used as a measure of potency in competing for visual awareness. Both dominant and untrustworthy faces resulted in slower t2e than neutral faces, with substantial individual variability in these effects. Individual differences in t2e were correlated with gray matter volume in right insula for dominant faces, and with gray matter volume in medial prefrontal cortex, right temporoparietal junction and bilateral fusiform face area for untrustworthy faces. Thus, individual differences in preconscious social processing can be predicted from local brain structure, and separable correlates for facial dominance and untrustworthiness suggest distinct mechanisms of preconscious processing. PMID:25193945

  17. Developing and validating risk prediction models in an individual participant data meta-analysis

    PubMed Central

    2014-01-01

    Background Risk prediction models estimate the risk of developing future outcomes for individuals based on one or more underlying characteristics (predictors). We review how researchers develop and validate risk prediction models within an individual participant data (IPD) meta-analysis, in order to assess the feasibility and conduct of the approach. Methods A qualitative review of the aims, methodology, and reporting in 15 articles that developed a risk prediction model using IPD from multiple studies. Results The IPD approach offers many opportunities but methodological challenges exist, including: unavailability of requested IPD, missing patient data and predictors, and between-study heterogeneity in methods of measurement, outcome definitions and predictor effects. Most articles develop their model using IPD from all available studies and perform only an internal validation (on the same set of data). Ten of the 15 articles did not allow for any study differences in baseline risk (intercepts), potentially limiting their model’s applicability and performance in some populations. Only two articles used external validation (on different data), including a novel method which develops the model on all but one of the IPD studies, tests performance in the excluded study, and repeats by rotating the omitted study. Conclusions An IPD meta-analysis offers unique opportunities for risk prediction research. Researchers can make more of this by allowing separate model intercept terms for each study (population) to improve generalisability, and by using ‘internal-external cross-validation’ to simultaneously develop and validate their model. Methodological challenges can be reduced by prospectively planned collaborations that share IPD for risk prediction. PMID:24397587

  18. Structured Set Intra Prediction With Discriminative Learning in a Max-Margin Markov Network for High Efficiency Video Coding

    PubMed Central

    Dai, Wenrui; Xiong, Hongkai; Jiang, Xiaoqian; Chen, Chang Wen

    2014-01-01

    This paper proposes a novel model on intra coding for High Efficiency Video Coding (HEVC), which simultaneously predicts blocks of pixels with optimal rate distortion. It utilizes the spatial statistical correlation for the optimal prediction based on 2-D contexts, in addition to formulating the data-driven structural interdependences to make the prediction error coherent with the probability distribution, which is desirable for successful transform and coding. The structured set prediction model incorporates a max-margin Markov network (M3N) to regulate and optimize multiple block predictions. The model parameters are learned by discriminating the actual pixel value from other possible estimates to maximize the margin (i.e., decision boundary bandwidth). Compared to existing methods that focus on minimizing prediction error, the M3N-based model adaptively maintains the coherence for a set of predictions. Specifically, the proposed model concurrently optimizes a set of predictions by associating the loss for individual blocks to the joint distribution of succeeding discrete cosine transform coefficients. When the sample size grows, the prediction error is asymptotically upper bounded by the training error under the decomposable loss function. As an internal step, we optimize the underlying Markov network structure to find states that achieve the maximal energy using expectation propagation. For validation, we integrate the proposed model into HEVC for optimal mode selection on rate-distortion optimization. The proposed prediction model obtains up to 2.85% bit rate reduction and achieves better visual quality in comparison to the HEVC intra coding. PMID:25505829

  19. Two Efficient Twin ELM Methods With Prediction Interval.

    PubMed

    Ning, Kefeng; Liu, Min; Dong, Mingyu; Wu, Cheng; Wu, ZhanSong

    2015-09-01

    In the operational optimization and scheduling problems of actual industrial processes, such as iron and steel, and microelectronics, the operational indices and process parameters usually need to be predicted. However, for some input and output variables of these prediction models, there may exist a lot of uncertainties coming from themselves, the measurement error, the rough representation, and so on. In such cases, constructing a prediction interval (PI) for the output of the corresponding prediction model is very necessary. In this paper, two twin extreme learning machine (TELM) models for constructing PIs are proposed. First, we propose a regularized asymmetric least squares extreme learning machine (RALS-ELM) method, in which different weights of its squared error loss function are set according to whether the error of the model output is positive or negative in order that the above error can be differentiated in the parameter learning process, and Tikhonov regularization is introduced to reduce overfitting. Then, we propose an asymmetric Bayesian extreme learning machine (AB-ELM) method based on the Bayesian framework with the asymmetric Gaussian distribution (AB-ELM), in which the weights of its likelihood function are determined as the same method in RALS-ELM, and the type II maximum likelihood algorithm is derived to learn the parameters of AB-ELM. Based on RALS-ELM and AB-ELM, we use a pair of weights following the reciprocal relationship to obtain two nonparallel regressors, including a lower-bound regressor and an upper-bound regressor, respectively, which can be used for calculating the PIs. Finally, some discussions are given, about how to adjust the weights adaptively to meet the desired PI, how to use the proposed TELMs for nonlinear quantile regression, and so on. Results of numerical comparison on data from one synthetic regression problem, three University of California Irvine benchmark regression problems, and two actual industrial regression

  20. Efficient multiview depth video coding using depth synthesis prediction

    NASA Astrophysics Data System (ADS)

    Lee, Cheon; Choi, Byeongho; Ho, Yo-Sung

    2011-07-01

    The view synthesis prediction (VSP) method utilizes interview correlations between views by generating an additional reference frame in the multiview video coding. This paper describes a multiview depth video coding scheme that incorporates depth view synthesis and additional prediction modes. In the proposed scheme, we exploit the reconstructed neighboring depth frame to generate an additional reference depth image for the current viewpoint to be coded using the depth image-based-rendering technique. In order to generate high-quality reference depth images, we used pre-processing on depth, depth image warping, and two types of hole filling methods depending on the number of available reference views. After synthesizing the additional depth image, we encode the depth video using the proposed additional prediction modes named VSP modes; those additional modes refer to the synthesized depth image. In particular, the VSP_SKIP mode refers to the co-located block of the synthesized frame without the coding motion vectors and residual data, which gives most of the coding gains. Experimental results demonstrate that the proposed depth view synthesis method provides high-quality depth images for the current view and the proposed VSP modes provide high coding gains, especially on the anchor frames.

  1. Predicting Efficient Antenna Ligands for Tb(III) Emission

    SciTech Connect

    Samuel, Amanda P.S.; Xu, Jide; Raymond, Kenneth

    2008-10-06

    A series of highly luminescent Tb(III) complexes of para-substituted 2-hydroxyisophthalamide ligands (5LI-IAM-X) has been prepared (X = H, CH{sub 3}, (C=O)NHCH{sub 3}, SO{sub 3}{sup -}, NO{sub 2}, OCH{sub 3}, F, Cl, Br) to probe the effect of substituting the isophthalamide ring on ligand and Tb(III) emission in order to establish a method for predicting the effects of chromophore modification on Tb(III) luminescence. The energies of the ligand singlet and triplet excited states are found to increase linearly with the {pi}-withdrawing ability of the substituent. The experimental results are supported by time-dependent density functional theory (TD-DFT) calculations performed on model systems, which predict ligand singlet and triplet energies within {approx}5% of the experimental values. The quantum yield ({Phi}) values of the Tb(III) complex increases with the triplet energy of the ligand, which is in part due to the decreased non-radiative deactivation caused by thermal repopulation of the triplet. Together, the experimental and theoretical results serve as a predictive tool that can be used to guide the synthesis of ligands used to sensitize lanthanide luminescence.

  2. Insula response to unpredictable and predictable aversiveness in individuals with panic disorder and comorbid depression

    PubMed Central

    2014-01-01

    Background Prior studies suggest that hyperactive insula responding to unpredictable aversiveness is a core feature of anxiety disorders. However, no study to date has investigated the neural correlates of unpredictable aversiveness in those with panic disorder (PD) with comorbid major depressive disorder (MDD). The aim of the current study was to examine group differences in neural responses to unpredictable and predictable aversiveness in 41 adults with either 1) current PD with comorbid MDD (PD-MDD), 2) current MDD with no lifetime diagnosis of an anxiety disorder (MDD-only), or 3) no lifetime diagnosis of psychopathology. All participants completed a functional magnetic resonance imaging (fMRI) scan while viewing temporally predictable or unpredictable negative or neutral images. Findings The results indicated that individuals with PD-MDD exhibited greater bilateral insula activation to unpredictable aversiveness compared with controls and individuals with MDD-only (who did not differ). There were no group differences in insula activation to predictable aversiveness. Conclusions These findings add to a growing literature highlighting the role of the insula in the pathophysiology of anxiety disorders. PMID:25337388

  3. Lexical familiarity and processing efficiency: individual differences in naming, lexical decision, and semantic categorization.

    PubMed

    Lewellen, M J; Goldinger, S D; Pisoni, D B; Greene, B G

    1993-09-01

    College students were separated into 2 groups (high and low) on the basis of 3 measures: subjective familiarity ratings of words, self-reported language experiences, and a test of vocabulary knowledge. Three experiments were conducted to determine if the groups also differed in visual word naming, lexical decision, and semantic categorization. High Ss were consistently faster than low Ss in naming visually presented words. They were also faster and more accurate in making difficult lexical decisions and in rejecting homophone foils in semantic categorization. Taken together, the results demonstrate that Ss who differ in lexical familiarity also differ in processing efficiency. The relationship between processing efficiency and working memory accounts of individual differences in language processing is also discussed. PMID:8371087

  4. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: Application of a biomarker development strategy

    PubMed Central

    Barron, Daniel S.; Fox, Peter T.; Pardoe, Heath; Lancaster, Jack; Price, Larry R.; Blackmon, Karen; Berry, Kristen; Cavazos, Jose E.; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas

    2014-01-01

    Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses. PMID:25610790

  5. Lower than predicted resting metabolic rate is associated with severely impaired cardiorespiratory fitness in obese individuals.

    PubMed

    Miller, Wendy M; Spring, Thomas J; Zalesin, Kerstyn C; Kaeding, Kaylee R; Nori Janosz, Katherine E; McCullough, Peter A; Franklin, Barry A

    2012-03-01

    Obese individuals have reduced cardiorespiratory fitness as compared with leaner counterparts. Regular exercise maintains or increases fitness and lean body mass. Lean body mass, in turn, has a direct impact on resting metabolic rate (RMR). Given these relationships, we sought to evaluate the association between RMR and cardiorespiratory fitness in obese individuals. We evaluated 64 obese individuals (78% female) with direct assessment of RMR and cardiorespiratory fitness via breath-by-breath measurement of oxygen consumption and carbon dioxide production at rest and during exercise. The mean age and BMI were 47.4 ± 12.2 years and 47.2 ± 9.2 kg/m(2), respectively. The majority of subjects, 69%, had a measured RMR above that predicted by the Harris-Benedict equation. Compared with the higher RMR group, those with a lower than predicted RMR had increased BMI, with values of 52.9 vs. 44.7 kg/m(2), P = 0.001, respectively. Analysis of those demonstrating significant effort during cardiopulmonary exercise testing (peak respiratory exchange ratio ≥1.10) revealed a significantly higher peak oxygen uptake (VO(2) peak) in the higher RMR group (17.3 ± 3.5 ml/min/kg) compared with the lower RMR group (13.6 ± 1.9 ml/min/kg), P = 0.003. In summary, a lower than predicted RMR was associated with a severely reduced VO(2) peak and a higher BMI in this cohort. These data suggest that morbid obesity may be a vicious cycle of increasing BMI, reduced cardiorespiratory fitness, muscle deconditioning, and lower RMR. Collectively, these responses may, over time, exacerbate the imbalance between energy intake and expenditure, resulting in progressive increases in body weight and fat stores.

  6. Pre-trauma individual differences in extinction learning predict posttraumatic stress.

    PubMed

    Lommen, Miriam J J; Engelhard, Iris M; Sijbrandij, Marit; van den Hout, Marcel A; Hermans, Dirk

    2013-02-01

    In the aftermath of a traumatic event, many people suffer from psychological distress, but only a minority develops posttraumatic stress disorder (PTSD). Pre-trauma individual differences in fear conditioning, most notably reduced extinction learning, have been proposed as playing an important role in the etiology of PTSD. However, prospective data are lacking. In this study, we prospectively tested whether reduced extinction was a predictor for later posttraumatic stress. Dutch soldiers (N = 249) were administered a conditioning task before their four-month deployment to Afghanistan to asses individual differences in extinction learning. After returning home, posttraumatic stress was measured. Results showed that reduced extinction learning before deployment predicted subsequent PTSD symptom severity, over and beyond degree of pre-deployment stress symptoms, neuroticism, and exposure to stressors on deployment. The findings suggest that reduced extinction learning may play a role in the development of PTSD.

  7. Acceleration response spectrum for prediction of structural vibration due to individual bouncing

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Wang, Lei; Racic, Vitomir; Lou, Jiayue

    2016-08-01

    This study is designed to develop an acceleration response spectrum that can be used in vibration serviceability assessment of civil engineering structures, such as floors and grandstands those are dynamically excited by individual bouncing. The spectrum is derived from numerical simulations and statistical analysis of acceleration responses of a single degree of freedom system with variable natural frequency and damping under a large number of experimentally measured individual bouncing loads. Its mathematical representation is fit for fast yet reliable application in design practice and is comprised of three equations that describe three distinct frequency regions observed in the actual data: the first resonant plateau (2-3.5 Hz), the second resonant plateau (4-7 Hz) and a descension region (7-15 Hz). Finally, this paper verifies the proposed response spectrum approach to predict structural vibration by direct comparison against numerical simulations and experimental results.

  8. Improving Neural Network Prediction Accuracy for PM10 Individual Air Quality Index Pollution Levels.

    PubMed

    Feng, Qi; Wu, Shengjun; Du, Yun; Xue, Huaiping; Xiao, Fei; Ban, Xuan; Li, Xiaodong

    2013-12-01

    Fugitive dust deriving from construction sites is a serious local source of particulate matter (PM) that leads to air pollution in cities undergoing rapid urbanization in China. In spite of this fact, no study has yet been published relating to prediction of high levels of PM with diameters <10 μm (PM10) as adjudicated by the Individual Air Quality Index (IAQI) on fugitive dust from nearby construction sites. To combat this problem, the Construction Influence Index (Ci) is introduced in this article to improve forecasting models based on three neural network models (multilayer perceptron, Elman, and support vector machine) in predicting daily PM10 IAQI one day in advance. To obtain acceptable forecasting accuracy, measured time series data were decomposed into wavelet representations and wavelet coefficients were predicted. Effectiveness of these forecasters were tested using a time series recorded between January 1, 2005, and December 31, 2011, at six monitoring stations situated within the urban area of the city of Wuhan, China. Experimental trials showed that the improved models provided low root mean square error values and mean absolute error values in comparison to the original models. In addition, these improved models resulted in higher values of coefficients of determination and AHPC (the accuracy rate of high PM10 IAQI caused by nearby construction activity) compared to the original models when predicting high PM10 IAQI levels attributable to fugitive dust from nearby construction sites. PMID:24381481

  9. RESIDUA UPGRADING EFFICIENCY IMPROVEMENT MODELS: COKE FORMATION PREDICTABILITY MAPS

    SciTech Connect

    John F. Schabron; A. Troy Pauli; Joseph F. Rovani Jr.

    2002-05-01

    The dispersed particle solution model of petroleum residua structure was used to develop predictors for pyrolytic coke formation. Coking Indexes were developed in prior years that measure how near a pyrolysis system is to coke formation during the coke formation induction period. These have been demonstrated to be universally applicable for residua regardless of the source of the material. Coking onset is coincidental with the destruction of the ordered structure and the formation of a multiphase system. The amount of coke initially formed appears to be a function of the free solvent volume of the original residua. In the current work, three-dimensional coke make predictability maps were developed at 400 C, 450 C, and 500 C (752 F, 842 F, and 932 F). These relate residence time and free solvent volume to the amount of coke formed at a particular pyrolysis temperature. Activation energies for two apparent types of zero-order coke formation reactions were estimated. The results provide a new tool for ranking residua, gauging proximity to coke formation, and predicting initial coke make tendencies.

  10. Efficient Unstructured Grid Adaptation Methods for Sonic Boom Prediction

    NASA Technical Reports Server (NTRS)

    Campbell, Richard L.; Carter, Melissa B.; Deere, Karen A.; Waithe, Kenrick A.

    2008-01-01

    This paper examines the use of two grid adaptation methods to improve the accuracy of the near-to-mid field pressure signature prediction of supersonic aircraft computed using the USM3D unstructured grid flow solver. The first method (ADV) is an interactive adaptation process that uses grid movement rather than enrichment to more accurately resolve the expansion and compression waves. The second method (SSGRID) uses an a priori adaptation approach to stretch and shear the original unstructured grid to align the grid with the pressure waves and reduce the cell count required to achieve an accurate signature prediction at a given distance from the vehicle. Both methods initially create negative volume cells that are repaired in a module in the ADV code. While both approaches provide significant improvements in the near field signature (< 3 body lengths) relative to a baseline grid without increasing the number of grid points, only the SSGRID approach allows the details of the signature to be accurately computed at mid-field distances (3-10 body lengths) for direct use with mid-field-to-ground boom propagation codes.

  11. Prediction of brain-computer interface aptitude from individual brain structure

    PubMed Central

    Halder, S.; Varkuti, B.; Bogdan, M.; Kübler, A.; Rosenstiel, W.; Sitaram, R.; Birbaumer, N.

    2013-01-01

    Objective: Brain-computer interface (BCI) provide a non-muscular communication channel for patients with impairments of the motor system. A significant number of BCI users is unable to obtain voluntary control of a BCI-system in proper time. This makes methods that can be used to determine the aptitude of a user necessary. Methods: We hypothesized that integrity and connectivity of involved white matter connections may serve as a predictor of individual BCI-performance. Therefore, we analyzed structural data from anatomical scans and DTI of motor imagery BCI-users differentiated into high and low BCI-aptitude groups based on their overall performance. Results: Using a machine learning classification method we identified discriminating structural brain trait features and correlated the best features with a continuous measure of individual BCI-performance. Prediction of the aptitude group of each participant was possible with near perfect accuracy (one error). Conclusions: Tissue volumetric analysis yielded only poor classification results. In contrast, the structural integrity and myelination quality of deep white matter structures such as the Corpus Callosum, Cingulum, and Superior Fronto-Occipital Fascicle were positively correlated with individual BCI-performance. Significance: This confirms that structural brain traits contribute to individual performance in BCI use. PMID:23565083

  12. Predicting and preventing ovarian hyperstimulation syndrome (OHSS): the need for individualized not standardized treatment

    PubMed Central

    2012-01-01

    Ovarian hyperstimulation syndrome (OHSS) is the most serious complication of controlled ovarian stimulation (COS) as part of assisted reproductive technologies (ART). While the safety and efficacy of ART is well established, physicians should always be aware of the risk of OHSS in patients undergoing COS, as it can be fatal. This article will briefly present the pathophysiology of OHSS, including the key role of vascular endothelial growth factor (VEGF), to provide the foundation for an overview of current techniques for the prevention of OHSS. Risk factors and predictive factors for OHSS will be presented, as recognizing these risk factors and individualizing the COS protocol appropriately is the key to the primary prevention of OHSS, as the benefits and risks of each COS strategy vary among individuals. Individualized COS (iCOS) could effectively eradicate OHSS, and the identification of hormonal, functional and genetic markers of ovarian response will facilitate iCOS. However, if iCOS is not properly applied, various preventive measures can be instituted once COS has begun, including cancelling the cycle, coasting, individualizing the human chorionic gonadotropin trigger dose or using a gonadotropin-releasing hormone (GnRH) agonist (for those using a GnRH antagonist protocol), the use of intravenous fluids at the time of oocyte retrieval, and cryopreserving/vitrifying all embryos for subsequent transfer in an unstimulated cycle. Some of these techniques have been widely adopted, despite the scarcity of data from randomized clinical trials to support their use. PMID:22531097

  13. Predicted Values of Cardiopulmonary Exercise Testing in Healthy Individuals (A Pilot Study)

    PubMed Central

    Mohammad, Majid Malek; Dadashpour, Shahdak

    2012-01-01

    Background Cardiopulmonary exercise testing evaluates the ability of one's cardiovascular and respiratory system in maximal exercise. This was a descriptive cross-sectional pilot study conducted at Masih Daneshvari Hospital in order to determine predicted values of cardiopulmonary exercise testing in individuals with normal physical activity patterns. Materials and Methods Thirty four individuals (14 women, 20 men) between 18-57 years of age were chosen using simple sampling method and evaluated with an incremental progressive cycle-ergometer test to a symptom-limited maximal tolerable work load. Subjects with a history of ischemic heart disease, pulmonary disease or neuromuscular disease were excluded from the study. Smokers were included but we made sure that all subjects had normal FEV1 and FEV1/FVC. This study aimed to compare measured values of VO2, VCO2, VO2/Kg, RER, O2pulse, HRR, HR, Load, Ant, BF, BR, VE, EQCO2, and EQO2 with previously published predicted values. Results We found that our obtained values for VO2 max, HRR max and HR max were different from standard tables but such difference was not observed for other understudy variables. Multiple linear regression analysis was done for height, weight and age (due to the small number of samples, no difference was detected between males and females). VO2 max and load max had reverse correlation with age and direct correlation with weight and height (P < 0.05) but the greatest correlation was observed for height. Conclusion Due to the small number of samples and poor correlations it was not possible to do regression analysis for other variables. In the next study with a larger sample size predicted values for all variables will be calculated. If the future study also indicates a significant difference between the predicted values and the reference values, we will need standard tables made specifically for our own country, Iran. PMID:25191396

  14. Efficient Reconstruction of Predictive Consensus Metabolic Network Models.

    PubMed

    van Heck, Ruben G A; Ganter, Mathias; Martins Dos Santos, Vitor A P; Stelling, Joerg

    2016-08-01

    Understanding cellular function requires accurate, comprehensive representations of metabolism. Genome-scale, constraint-based metabolic models (GSMs) provide such representations, but their usability is often hampered by inconsistencies at various levels, in particular for concurrent models. COMMGEN, our tool for COnsensus Metabolic Model GENeration, automatically identifies inconsistencies between concurrent models and semi-automatically resolves them, thereby contributing to consolidate knowledge of metabolic function. Tests of COMMGEN for four organisms showed that automatically generated consensus models were predictive and that they substantially increased coherence of knowledge representation. COMMGEN ought to be particularly useful for complex scenarios in which manual curation does not scale, such as for eukaryotic organisms, microbial communities, and host-pathogen interactions. PMID:27563720

  15. Efficient Reconstruction of Predictive Consensus Metabolic Network Models

    PubMed Central

    Martins dos Santos, Vitor A. P.; Stelling, Joerg

    2016-01-01

    Understanding cellular function requires accurate, comprehensive representations of metabolism. Genome-scale, constraint-based metabolic models (GSMs) provide such representations, but their usability is often hampered by inconsistencies at various levels, in particular for concurrent models. COMMGEN, our tool for COnsensus Metabolic Model GENeration, automatically identifies inconsistencies between concurrent models and semi-automatically resolves them, thereby contributing to consolidate knowledge of metabolic function. Tests of COMMGEN for four organisms showed that automatically generated consensus models were predictive and that they substantially increased coherence of knowledge representation. COMMGEN ought to be particularly useful for complex scenarios in which manual curation does not scale, such as for eukaryotic organisms, microbial communities, and host-pathogen interactions. PMID:27563720

  16. Predictability of the individual clinical outcome of extracorporeal shock wave therapy for cellulite

    PubMed Central

    Schlaudraff, Kai-Uwe; Kiessling, Maren C; Császár, Nikolaus BM; Schmitz, Christoph

    2014-01-01

    Background Extracorporeal shock wave therapy has been successfully introduced for the treatment of cellulite in recent years. However, it is still unknown whether the individual clinical outcome of cellulite treatment with extracorporeal shock wave therapy can be predicted by the patient’s individual cellulite grade at baseline, individual patient age, body mass index (BMI), weight, and/or height. Methods Fourteen Caucasian females with cellulite were enrolled in a prospective, single-center, randomized, open-label Phase II study. The mean (± standard error of the mean) cellulite grade at baseline was 2.5±0.09 and mean BMI was 22.8±1.17. All patients were treated with radial extracorporeal shock waves using the Swiss DolorClast® device (Electro Medical Systems, S.A., Nyon, Switzerland). Patients were treated unilaterally with 2 weekly treatments for 4 weeks on a randomly selected side (left or right), totaling eight treatments on the selected side. Treatment was performed at 3.5–4.0 bar, with 15,000 impulses per session applied at 15 Hz. Impulses were homogeneously distributed over the posterior thigh and buttock area (resulting in 7,500 impulses per area). Treatment success was evaluated after the last treatment and 4 weeks later by clinical examination, photographic documentation, contact thermography, and patient satisfaction questionnaires. Results The mean cellulite grade improved from 2.5±0.09 at baseline to 1.57±0.18 after the last treatment (ie, mean δ-1 was 0.93 cellulite grades) and 1.68±0.16 at follow-up (ie, mean δ-2 was 0.82 cellulite grades). Compared with baseline, no patient’s condition worsened, the treatment was well tolerated, and no unwanted side effects were observed. No statistically significant (ie, P<0.05) correlation was found between individual values for δ-1 and δ-2 and cellulite grade at baseline, BMI, weight, height, or age. Conclusion Radial shock wave therapy is a safe and effective treatment option for cellulite. The

  17. Age-related and individual differences in the use of prediction during language comprehension

    PubMed Central

    Federmeier, Kara D.; Kutas, Marta; Schul, Rina

    2010-01-01

    During sentence comprehension, older adults are less likely than younger adults to predict features of likely upcoming words. A pair of experiments assessed whether such differences would extend to tasks with reduced working memory demands and time pressures. In Experiment 1, event-related brain potentials were measured as younger and older adults read short phrases cuing antonyms or category exemplars, followed three seconds later by targets that were either congruent or incongruent and, for congruent category exemplars, of higher or lower typicality. When processing the less expected low typicality targets, younger – but not older – adults elicited a prefrontal positivity (500–900 ms) that has been linked to processing consequences of having predictions disconfirmed. Thus, age-related changes in prediction during comprehension generalize across task circumstances. Analyses of individual differences revealed that older adults with higher category fluency were more likely to show the young-like pattern. Experiment 2 showed that these age-related differences were not due to simple slowing of language production mechanisms, as older adults generated overt responses to the cues as quickly as – and more accurately than – younger adults. However, older adults who were relatively faster to produce category exemplars in Experiment 2 were more likely to have shown predictive processing patterns in Experiment 1. Taken together, the results link prediction during language comprehension to language production mechanisms and suggest that although older adults can produce speeded language output on demand, they are less likely to automatically recruit these mechanisms during comprehension unless top-down circuitry is particularly strong. PMID:20728207

  18. Individual differences in white matter anatomy predict dissociable components of reading skill in adults.

    PubMed

    Welcome, Suzanne E; Joanisse, Marc F

    2014-08-01

    We used diffusion tensor imaging (DTI) to investigate relationships between white matter anatomy and different reading subskills in typical-reading adults. A series of analytic approaches revealed that phonological decoding ability is associated with anatomical markers that do not relate to other reading-related cognitive abilities. Thus, individual differences in phonological decoding might relate to connectivity between a network of cortical regions, while skills like sight word reading might rely less strongly on integration across regions. Specifically, manually-drawn ROIs and probabilistic tractography revealed an association between the volume and integrity of white matter underlying primary auditory cortex and nonword reading ability. In a related finding, more extensive cross-hemispheric connections through the isthmus of the corpus callosum predicted better phonological decoding. Atlas-based white matter ROIs demonstrated that relationships with nonword reading were strongest in the inferior fronto-occipital fasciculus and uncinate fasciculus that connect occipital and anterior temporal cortex with inferior frontal cortex. In contrast, tract volume underlying the left angular gyrus was related to nonverbal IQ. Finally, connectivity underlying functional ROIs that are differentially active during phonological and semantic processing predicted nonword reading and reading comprehension, respectively. Together, these results provide important insights into how white matter anatomy may relate to both typical reading subskills, and perhaps a roadmap for understanding neural connectivity in individuals with reading impairments.

  19. Individual differences in bodily freezing predict emotional biases in decision making

    PubMed Central

    Ly, Verena; Huys, Quentin J. M.; Stins, John F.; Roelofs, Karin; Cools, Roshan

    2014-01-01

    Instrumental decision making has long been argued to be vulnerable to emotional responses. Literature on multiple decision making systems suggests that this emotional biasing might reflect effects of a system that regulates innately specified, evolutionarily preprogrammed responses. To test this hypothesis directly, we investigated whether effects of emotional faces on instrumental action can be predicted by effects of emotional faces on bodily freezing, an innately specified response to aversive relative to appetitive cues. We tested 43 women using a novel emotional decision making task combined with posturography, which involves a force platform to detect small oscillations of the body to accurately quantify postural control in upright stance. On the platform, participants learned whole body approach-avoidance actions based on monetary feedback, while being primed by emotional faces (angry/happy). Our data evidence an emotional biasing of instrumental action. Thus, angry relative to happy faces slowed instrumental approach relative to avoidance responses. Critically, individual differences in this emotional biasing effect were predicted by individual differences in bodily freezing. This result suggests that emotional biasing of instrumental action involves interaction with a system that controls innately specified responses. Furthermore, our findings help bridge (animal and human) decision making and emotion research to advance our mechanistic understanding of decision making anomalies in daily encounters as well as in a wide range of psychopathology. PMID:25071491

  20. Factors Motivating Individuals to Consider Genetic Testing for Type 2 Diabetes Risk Prediction.

    PubMed

    Wessel, Jennifer; Gupta, Jyoti; de Groot, Mary

    2016-01-01

    The purpose of this study was to identify attitudes and perceptions of willingness to participate in genetic testing for type 2 diabetes (T2D) risk prediction in the general population. Adults (n = 598) were surveyed on attitudes about utilizing genetic testing to predict future risk of T2D. Participants were recruited from public libraries (53%), online registry (37%) and a safety net hospital emergency department (10%). Respondents were 37 ± 11 years old, primarily White (54%), female (69%), college educated (46%), with an annual income ≥$25,000 (56%). Half of participants were interested in genetic testing for T2D (52%) and 81% agreed/strongly agreed genetic testing should be available to the public. Only 57% of individuals knew T2D is preventable. A multivariate model to predict interest in genetic testing was adjusted for age, gender, recruitment location and BMI; significant predictors were motivation (high perceived personal risk of T2D [OR = 4.38 (1.76, 10.9)]; family history [OR = 2.56 (1.46, 4.48)]; desire to know risk prior to disease onset [OR = 3.25 (1.94, 5.42)]; and knowing T2D is preventable [OR = 2.11 (1.24, 3.60)], intention (if the cost is free [OR = 10.2 (4.27, 24.6)]; and learning T2D is preventable [OR = 5.18 (1.95, 13.7)]) and trust of genetic testing results [OR = 0.03 (0.003, 0.30)]. Individuals are interested in genetic testing for T2D risk which offers unique information that is personalized. Financial accessibility, validity of the test and availability of diabetes prevention programs were identified as predictors of interest in T2D testing.

  1. Individual differences in cortisol stress response predict increases in voice pitch during exam stress.

    PubMed

    Pisanski, Katarzyna; Nowak, Judyta; Sorokowski, Piotr

    2016-09-01

    Despite a long history of empirical research, the potential vocal markers of stress remain unclear. Previous studies examining speech under stress most consistently report an increase in voice pitch (the acoustic correlate of fundamental frequency, F0), however numerous studies have failed to replicate this finding. In the present study we tested the prediction that these inconsistencies are tied to variation in the severity of the stress response, wherein voice changes may be observed predominantly among individuals who show a cortisol stress response (i.e., an increase in free cortisol levels) above a critical threshold. Voice recordings and saliva samples were collected from university psychology students at baseline and again immediately prior to an oral examination. Voice recordings included both read and spontaneous speech, from which we measured mean, minimum, maximum, and the standard deviation in F0. We observed an increase in mean and minimum F0 under stress in both read and spontaneous speech, whereas maximum F0 and its standard deviation showed no systematic changes under stress. Our results confirmed that free cortisol levels increased by an average of 74% (ranging from 0 to 270%) under stress. Critically, increases in cortisol concentrations significantly predicted increases in mean F0 under stress for both speech types, but did not predict variation in F0 at baseline. On average, stress-induced increases in voice pitch occurred only when free cortisol levels more than doubled their baseline concentrations. Our results suggest that researchers examining speech under stress should control for individual differences in the magnitude of the stress response. PMID:27188981

  2. Factors Motivating Individuals to Consider Genetic Testing for Type 2 Diabetes Risk Prediction

    PubMed Central

    Wessel, Jennifer; Gupta, Jyoti; de Groot, Mary

    2016-01-01

    The purpose of this study was to identify attitudes and perceptions of willingness to participate in genetic testing for type 2 diabetes (T2D) risk prediction in the general population. Adults (n = 598) were surveyed on attitudes about utilizing genetic testing to predict future risk of T2D. Participants were recruited from public libraries (53%), online registry (37%) and a safety net hospital emergency department (10%). Respondents were 37±11 years old, primarily White (54%), female (69%), college educated (46%), with an annual income ≥$25,000 (56%). Half of participants were interested in genetic testing for T2D (52%) and 81% agreed/strongly agreed genetic testing should be available to the public. Only 57% of individuals knew T2D is preventable. A multivariate model to predict interest in genetic testing was adjusted for age, gender, recruitment location and BMI; significant predictors were motivation (high perceived personal risk of T2D [OR = 4.38 (1.76, 10.9)]; family history [OR = 2.56 (1.46, 4.48)]; desire to know risk prior to disease onset [OR = 3.25 (1.94, 5.42)]; and knowing T2D is preventable [OR = 2.11 (1.24, 3.60)], intention (if the cost is free [OR = 10.2 (4.27, 24.6)]; and learning T2D is preventable [OR = 5.18 (1.95, 13.7)]) and trust of genetic testing results [OR = 0.03 (0.003, 0.30)]. Individuals are interested in genetic testing for T2D risk which offers unique information that is personalized. Financial accessibility, validity of the test and availability of diabetes prevention programs were identified as predictors of interest in T2D testing. PMID:26789839

  3. Factors Motivating Individuals to Consider Genetic Testing for Type 2 Diabetes Risk Prediction.

    PubMed

    Wessel, Jennifer; Gupta, Jyoti; de Groot, Mary

    2016-01-01

    The purpose of this study was to identify attitudes and perceptions of willingness to participate in genetic testing for type 2 diabetes (T2D) risk prediction in the general population. Adults (n = 598) were surveyed on attitudes about utilizing genetic testing to predict future risk of T2D. Participants were recruited from public libraries (53%), online registry (37%) and a safety net hospital emergency department (10%). Respondents were 37 ± 11 years old, primarily White (54%), female (69%), college educated (46%), with an annual income ≥$25,000 (56%). Half of participants were interested in genetic testing for T2D (52%) and 81% agreed/strongly agreed genetic testing should be available to the public. Only 57% of individuals knew T2D is preventable. A multivariate model to predict interest in genetic testing was adjusted for age, gender, recruitment location and BMI; significant predictors were motivation (high perceived personal risk of T2D [OR = 4.38 (1.76, 10.9)]; family history [OR = 2.56 (1.46, 4.48)]; desire to know risk prior to disease onset [OR = 3.25 (1.94, 5.42)]; and knowing T2D is preventable [OR = 2.11 (1.24, 3.60)], intention (if the cost is free [OR = 10.2 (4.27, 24.6)]; and learning T2D is preventable [OR = 5.18 (1.95, 13.7)]) and trust of genetic testing results [OR = 0.03 (0.003, 0.30)]. Individuals are interested in genetic testing for T2D risk which offers unique information that is personalized. Financial accessibility, validity of the test and availability of diabetes prevention programs were identified as predictors of interest in T2D testing. PMID:26789839

  4. Sibling configuration predicts individual and descendant socioeconomic success in a modern post-industrial society.

    PubMed

    Lawson, David W; Makoli, Arijeta; Goodman, Anna

    2013-01-01

    Growing up with many siblings, at least in the context of modern post-industrial low fertility, low mortality societies, is predictive of relatively poor performance on school tests in childhood, lower levels of educational attainment, and lower income throughout adulthood. Recent studies further indicate these relationships hold across generations, so that the descendants of those who grow up with many siblings are also at an apparent socioeconomic disadvantage. In this paper we add to this literature by considering whether such relationships interact with the sex and relative age of siblings. To do this we utilise a unique Swedish multigenerational birth cohort study that provides sibling configuration data on over 10,000 individuals born in 1915-1929, plus all their direct genetic descendants to the present day. Adjusting for parental and birth characteristics, we find that the 'socioeconomic cost' of growing up in a large family is independent of both the sex of siblings and the sex of the individual. However, growing up with several older as opposed to several younger siblings is predictive of relatively poor performance on school tests and a lower likelihood of progression to tertiary education. This later-born disadvantage also holds across generations, with the children of those with many older siblings achieving lower levels of educational attainment. Despite these differences, we find that while individual and descendant income is negatively related to the number of siblings, it is not influenced by the relative age of siblings. Thus, our findings imply that the educational disadvantage of later-born children, demonstrated here and in numerous other studies, does not necessarily translate into reduced earnings in adulthood. We discuss potential explanations for this pattern of results, and consider some important directions for future research into sibling configuration and wellbeing in modern societies.

  5. Individualized Prediction of Changes in 6-Minute Walk Distance for Patients with Duchenne Muscular Dystrophy

    PubMed Central

    Goemans, Nathalie; vanden Hauwe, Marleen; Signorovitch, James; Swallow, Elyse; Song, Jinlin

    2016-01-01

    Background Deficits in ambulatory function progress at heterogeneous rates among individuals with Duchenne muscular dystrophy (DMD). The resulting inherent variability in ambulatory outcomes has complicated the design of drug efficacy trials and clouded the interpretation of trial results. We developed a prediction model for 1-year change in the six minute walk distance (6MWD) among DMD patients, and compared its predictive value to that of commonly used prognostic factors (age, baseline 6MWD, and steroid use). Methods Natural history data were collected from DMD patients at routine follow up visits approximately every 6 months over the course of 2–5 years. Assessments included ambulatory function and steroid use. The annualized change in 6MWD (Δ6MWD) was studied between all pairs of visits separated by 8–16 months. Prediction models were developed using multivariable regression for repeated measures, and evaluated using cross-validation. Results Among n = 191 follow-up intervals (n = 39 boys), mean starting age was 9.4 years, mean starting 6MWD was 351.8 meters, and 75% had received steroids for at least one year. Over the subsequent 8–16 months, mean Δ6MWD was -37.0 meters with a standard deviation (SD) of 93.7 meters. Predictions based on a composite of age, baseline 6MWD, and steroid use explained 28% of variation in Δ6MWD (R2 = 0.28, residual SD = 79.4 meters). A broadened prognostic model, adding timed 10-meter walk/run, 4-stair climb, and rise from supine, as well as height and weight, significantly improved prediction, explaining 59% of variation in Δ6MWD after cross-validation (R2 = 0.59, residual SD = 59.7 meters). Conclusions A prognostic model incorporating timed function tests significantly improved prediction of 1-year changes in 6MWD. Explained variation was more than doubled compared to predictions based only on age, baseline 6MWD, and steroid use. There is significant potential for composite prognostic models to inform DMD clinical trials

  6. Individual differences in nonlinguistic event categorization predict later motion verb comprehension.

    PubMed

    Konishi, Haruka; Stahl, Aimee E; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathy

    2016-11-01

    This study probes how individual differences in early event perception predict later verb knowledge. At Time 1, when infants were 13 to 15months of age, they saw videotaped silent scenes performed by a human actor. The goal was to see whether infants could form categories of path (a figure's trajectory with respect to a ground object) and manner (how an action is performed). Infants either saw the same manner (e.g., jogging) taking place across three different paths (around, through, and behind) or saw the same path (e.g., around a tent) taking place across three different manners (running, crawling, and walking). After familiarization, either the path or the manner was changed and visual fixation was monitored using preferential looking. At Time 2, the same children were tested on their comprehension of verbs in a two-choice pointing task showing two simultaneous actions (e.g., running vs. jumping). Success at categorization of path and manner at Time 1 predicted verb comprehension at Time 2, even when taking language knowledge at both time points into account. These preliminary results represent headway in identifying the factors that may contribute to children's language learning. They suggest that skill in categorizing semantic components present in nonlinguistic events is predictive of children's later verb vocabulary. PMID:27139436

  7. Labour-efficient in vitro lymphocyte population tracking and fate prediction using automation and manual review.

    PubMed

    Chakravorty, Rajib; Rawlinson, David; Zhang, Alan; Markham, John; Dowling, Mark R; Wellard, Cameron; Zhou, Jie H S; Hodgkin, Philip D

    2014-01-01

    Interest in cell heterogeneity and differentiation has recently led to increased use of time-lapse microscopy. Previous studies have shown that cell fate may be determined well in advance of the event. We used a mixture of automation and manual review of time-lapse live cell imaging to track the positions, contours, divisions, deaths and lineage of 44 B-lymphocyte founders and their 631 progeny in vitro over a period of 108 hours. Using this data to train a Support Vector Machine classifier, we were retrospectively able to predict the fates of individual lymphocytes with more than 90% accuracy, using only time-lapse imaging captured prior to mitosis or death of 90% of all cells. The motivation for this paper is to explore the impact of labour-efficient assistive software tools that allow larger and more ambitious live-cell time-lapse microscopy studies. After training on this data, we show that machine learning methods can be used for realtime prediction of individual cell fates. These techniques could lead to realtime cell culture segregation for purposes such as phenotype screening. We were able to produce a large volume of data with less effort than previously reported, due to the image processing, computer vision, tracking and human-computer interaction tools used. We describe the workflow of the software-assisted experiments and the graphical interfaces that were needed. To validate our results we used our methods to reproduce a variety of published data about lymphocyte populations and behaviour. We also make all our data publicly available, including a large quantity of lymphocyte spatio-temporal dynamics and related lineage information. PMID:24404133

  8. Individual differences in left parietal white matter predict math scores on the Preliminary Scholastic Aptitude Test.

    PubMed

    Matejko, Anna A; Price, Gavin R; Mazzocco, Michèle M M; Ansari, Daniel

    2013-02-01

    Mathematical skills are of critical importance, both academically and in everyday life. Neuroimaging research has primarily focused on the relationship between mathematical skills and functional brain activity. Comparatively few studies have examined which white matter regions support mathematical abilities. The current study uses diffusion tensor imaging (DTI) to test whether individual differences in white matter predict performance on the math subtest of the Preliminary Scholastic Aptitude Test (PSAT). Grades 10 and 11 PSAT scores were obtained from 30 young adults (ages 17-18) with wide-ranging math achievement levels. Tract based spatial statistics was used to examine the correlation between PSAT math scores, fractional anisotropy (FA), radial diffusivity (RD) and axial diffusivity (AD). FA in left parietal white matter was positively correlated with math PSAT scores (specifically in the left superior longitudinal fasciculus, left superior corona radiata, and left corticospinal tract) after controlling for chronological age and same grade PSAT critical reading scores. Furthermore, RD, but not AD, was correlated with PSAT math scores in these white matter microstructures. The negative correlation with RD further suggests that participants with higher PSAT math scores have greater white matter integrity in this region. Individual differences in FA and RD may reflect variability in experience dependent plasticity over the course of learning and development. These results are the first to demonstrate that individual differences in white matter are associated with mathematical abilities on a nationally administered scholastic aptitude measure.

  9. Emotion, working memory task demands and individual differences predict behavior, cognitive effort and negative affect.

    PubMed

    Storbeck, Justin; Davidson, Nicole A; Dahl, Chelsea F; Blass, Sara; Yung, Edwin

    2015-01-01

    We examined whether positive and negative affect motivates verbal and spatial working memory processes, respectively, which have implications for the expenditure of mental effort. We argue that when emotion promotes cognitive tendencies that are goal incompatible with task demands, greater cognitive effort is required to perform well. We sought to investigate whether this increase in cognitive effort impairs behavioural control over a broad domain of self-control tasks. Moreover, we predicted that individuals with higher behavioural inhibition system (BIS) sensitivities would report more negative affect within the goal incompatible conditions because such individuals report higher negative affect during cognitive challenge. Positive or negative affective states were induced followed by completing a verbal or spatial 2-back working memory task. All participants then completed one of three self-control tasks. Overall, we observed that conditions of emotion and working memory incompatibility (positive/spatial and negative/verbal) performed worse on the self-control tasks, and within the incompatible conditions individuals with higher BIS sensitivities reported more negative affect at the end of the study. The combination of findings suggests that emotion and working memory compatibility reduces cognitive effort and impairs behavioural control.

  10. Efficient Helicopter Aerodynamic and Aeroacoustic Predictions on Parallel Computers

    NASA Technical Reports Server (NTRS)

    Wissink, Andrew M.; Lyrintzis, Anastasios S.; Strawn, Roger C.; Oliker, Leonid; Biswas, Rupak

    1996-01-01

    This paper presents parallel implementations of two codes used in a combined CFD/Kirchhoff methodology to predict the aerodynamics and aeroacoustics properties of helicopters. The rotorcraft Navier-Stokes code, TURNS, computes the aerodynamic flowfield near the helicopter blades and the Kirchhoff acoustics code computes the noise in the far field, using the TURNS solution as input. The overall parallel strategy adds MPI message passing calls to the existing serial codes to allow for communication between processors. As a result, the total code modifications required for parallel execution are relatively small. The biggest bottleneck in running the TURNS code in parallel comes from the LU-SGS algorithm that solves the implicit system of equations. We use a new hybrid domain decomposition implementation of LU-SGS to obtain good parallel performance on the SP-2. TURNS demonstrates excellent parallel speedups for quasi-steady and unsteady three-dimensional calculations of a helicopter blade in forward flight. The execution rate attained by the code on 114 processors is six times faster than the same cases run on one processor of the Cray C-90. The parallel Kirchhoff code also shows excellent parallel speedups and fast execution rates. As a performance demonstration, unsteady acoustic pressures are computed at 1886 far-field observer locations for a sample acoustics problem. The calculation requires over two hundred hours of CPU time on one C-90 processor but takes only a few hours on 80 processors of the SP2. The resultant far-field acoustic field is analyzed with state of-the-art audio and video rendering of the propagating acoustic signals.

  11. Predicting brain activation patterns associated with individual lexical concepts based on five sensory-motor attributes

    PubMed Central

    Fernandino, Leonardo; Humphries, Colin J.; Seidenberg, Mark S.; Gross, William L.; Conant, Lisa L.; Binder, Jeffrey R.

    2015-01-01

    While major advances have been made in uncovering the neural processes underlying perceptual representations, our grasp of how the brain gives rise to conceptual knowledge remains relatively poor. Recent work has provided strong evidence that concepts rely, at least in part, on the same sensory and motor neural systems through which they were acquired, but it is still unclear whether the neural code for concept representation uses information about sensory-motor features to discriminate between concepts. In the present study, we investigate this question by asking whether an encoding model based on five semantic attributes directly related to sensory-motor experience – sound, color, visual motion, shape, and manipulation – can successfully predict patterns of brain activation elicited by individual lexical concepts. We collected ratings on the relevance of these five attributes to the meaning of 820 words, and used these ratings as predictors in a multiple regression model of the fMRI signal associated with the words in a separate group of participants. The five resulting activation maps were then combined by linear summation to predict the distributed activation pattern elicited by a novel set of 80 test words. The encoding model predicted the activation patterns elicited by the test words significantly better than chance. As expected, prediction was successful for concrete but not for abstract concepts. Comparisons between encoding models based on different combinations of attributes indicate that all five attributes contribute to the representation of concrete concepts. Consistent with embodied theories of semantics, these results show, for the first time, that the distributed activation pattern associated with a concept combines information about different sensory-motor attributes according to their respective relevance. Future research should investigate how additional features of phenomenal experience contribute to the neural representation of conceptual

  12. A general model to predict individual exposure to solar UV by using ambient irradiance data.

    PubMed

    Vernez, David; Milon, Antoine; Vuilleumier, Laurent; Bulliard, Jean-Luc; Koechlin, Alice; Boniol, Mathieu; Doré, Jean F

    2015-01-01

    Excessive exposure to solar ultraviolet (UV) is the main cause of skin cancer. Specific prevention should be further developed to target overexposed or highly vulnerable populations. A better characterisation of anatomical UV exposure patterns is however needed for specific prevention. To develop a regression model for predicting the UV exposure ratio (ER, ratio between the anatomical dose and the corresponding ground level dose) for each body site without requiring individual measurements. A 3D numeric model (SimUVEx) was used to compute ER for various body sites and postures. A multiple fractional polynomial regression analysis was performed to identify predictors of ER. The regression model used simulation data and its performance was tested on an independent data set. Two input variables were sufficient to explain ER: the cosine of the maximal daily solar zenith angle and the fraction of the sky visible from the body site. The regression model was in good agreement with the simulated data ER (R(2)=0.988). Relative errors up to +20% and -10% were found in daily doses predictions, whereas an average relative error of only 2.4% (-0.03% to 5.4%) was found in yearly dose predictions. The regression model predicts accurately ER and UV doses on the basis of readily available data such as global UV erythemal irradiance measured at ground surface stations or inferred from satellite information. It renders the development of exposure data on a wide temporal and geographical scale possible and opens broad perspectives for epidemiological studies and skin cancer prevention.

  13. Predicting brain activation patterns associated with individual lexical concepts based on five sensory-motor attributes.

    PubMed

    Fernandino, Leonardo; Humphries, Colin J; Seidenberg, Mark S; Gross, William L; Conant, Lisa L; Binder, Jeffrey R

    2015-09-01

    While major advances have been made in uncovering the neural processes underlying perceptual representations, our grasp of how the brain gives rise to conceptual knowledge remains relatively poor. Recent work has provided strong evidence that concepts rely, at least in part, on the same sensory and motor neural systems through which they were acquired, but it is still unclear whether the neural code for concept representation uses information about sensory-motor features to discriminate between concepts. In the present study, we investigate this question by asking whether an encoding model based on five semantic attributes directly related to sensory-motor experience - sound, color, visual motion, shape, and manipulation - can successfully predict patterns of brain activation elicited by individual lexical concepts. We collected ratings on the relevance of these five attributes to the meaning of 820 words, and used these ratings as predictors in a multiple regression model of the fMRI signal associated with the words in a separate group of participants. The five resulting activation maps were then combined by linear summation to predict the distributed activation pattern elicited by a novel set of 80 test words. The encoding model predicted the activation patterns elicited by the test words significantly better than chance. As expected, prediction was successful for concrete but not for abstract concepts. Comparisons between encoding models based on different combinations of attributes indicate that all five attributes contribute to the representation of concrete concepts. Consistent with embodied theories of semantics, these results show, for the first time, that the distributed activation pattern associated with a concept combines information about different sensory-motor attributes according to their respective relevance. Future research should investigate how additional features of phenomenal experience contribute to the neural representation of conceptual

  14. Multimodal Learning and Intelligent Prediction of Symptom Development in Individual Parkinson's Patients.

    PubMed

    Przybyszewski, Andrzej W; Kon, Mark; Szlufik, Stanislaw; Szymanski, Artur; Habela, Piotr; Koziorowski, Dariusz M

    2016-01-01

    We still do not know how the brain and its computations are affected by nerve cell deaths and their compensatory learning processes, as these develop in neurodegenerative diseases (ND). Compensatory learning processes are ND symptoms usually observed at a point when the disease has already affected large parts of the brain. We can register symptoms of ND such as motor and/or mental disorders (dementias) and even provide symptomatic relief, though the structural effects of these are in most cases not yet understood. It is very important to obtain early diagnosis, which can provide several years in which we can monitor and partly compensate for the disease's symptoms, with the help of various therapies. In the case of Parkinson's disease (PD), in addition to classical neurological tests, measurements of eye movements are diagnostic. We have performed measurements of latency, amplitude, and duration in reflexive saccades (RS) of PD patients. We have compared the results of our measurement-based diagnoses with standard neurological ones. The purpose of our work was to classify how condition attributes predict the neurologist's diagnosis. For n = 10 patients, the patient age and parameters based on RS gave a global accuracy in predictions of neurological symptoms in individual patients of about 80%. Further, by adding three attributes partly related to patient 'well-being' scores, our prediction accuracies increased to 90%. Our predictive algorithms use rough set theory, which we have compared with other classifiers such as Naïve Bayes, Decision Trees/Tables, and Random Forests (implemented in KNIME/WEKA). We have demonstrated that RS are powerful biomarkers for assessment of symptom progression in PD.

  15. Multimodal Learning and Intelligent Prediction of Symptom Development in Individual Parkinson’s Patients

    PubMed Central

    Przybyszewski, Andrzej W.; Kon, Mark; Szlufik, Stanislaw; Szymanski, Artur; Habela, Piotr; Koziorowski, Dariusz M.

    2016-01-01

    We still do not know how the brain and its computations are affected by nerve cell deaths and their compensatory learning processes, as these develop in neurodegenerative diseases (ND). Compensatory learning processes are ND symptoms usually observed at a point when the disease has already affected large parts of the brain. We can register symptoms of ND such as motor and/or mental disorders (dementias) and even provide symptomatic relief, though the structural effects of these are in most cases not yet understood. It is very important to obtain early diagnosis, which can provide several years in which we can monitor and partly compensate for the disease’s symptoms, with the help of various therapies. In the case of Parkinson’s disease (PD), in addition to classical neurological tests, measurements of eye movements are diagnostic. We have performed measurements of latency, amplitude, and duration in reflexive saccades (RS) of PD patients. We have compared the results of our measurement-based diagnoses with standard neurological ones. The purpose of our work was to classify how condition attributes predict the neurologist’s diagnosis. For n = 10 patients, the patient age and parameters based on RS gave a global accuracy in predictions of neurological symptoms in individual patients of about 80%. Further, by adding three attributes partly related to patient ‘well-being’ scores, our prediction accuracies increased to 90%. Our predictive algorithms use rough set theory, which we have compared with other classifiers such as Naïve Bayes, Decision Trees/Tables, and Random Forests (implemented in KNIME/WEKA). We have demonstrated that RS are powerful biomarkers for assessment of symptom progression in PD. PMID:27649187

  16. Multimodal Learning and Intelligent Prediction of Symptom Development in Individual Parkinson's Patients.

    PubMed

    Przybyszewski, Andrzej W; Kon, Mark; Szlufik, Stanislaw; Szymanski, Artur; Habela, Piotr; Koziorowski, Dariusz M

    2016-01-01

    We still do not know how the brain and its computations are affected by nerve cell deaths and their compensatory learning processes, as these develop in neurodegenerative diseases (ND). Compensatory learning processes are ND symptoms usually observed at a point when the disease has already affected large parts of the brain. We can register symptoms of ND such as motor and/or mental disorders (dementias) and even provide symptomatic relief, though the structural effects of these are in most cases not yet understood. It is very important to obtain early diagnosis, which can provide several years in which we can monitor and partly compensate for the disease's symptoms, with the help of various therapies. In the case of Parkinson's disease (PD), in addition to classical neurological tests, measurements of eye movements are diagnostic. We have performed measurements of latency, amplitude, and duration in reflexive saccades (RS) of PD patients. We have compared the results of our measurement-based diagnoses with standard neurological ones. The purpose of our work was to classify how condition attributes predict the neurologist's diagnosis. For n = 10 patients, the patient age and parameters based on RS gave a global accuracy in predictions of neurological symptoms in individual patients of about 80%. Further, by adding three attributes partly related to patient 'well-being' scores, our prediction accuracies increased to 90%. Our predictive algorithms use rough set theory, which we have compared with other classifiers such as Naïve Bayes, Decision Trees/Tables, and Random Forests (implemented in KNIME/WEKA). We have demonstrated that RS are powerful biomarkers for assessment of symptom progression in PD. PMID:27649187

  17. Predicting brain activation patterns associated with individual lexical concepts based on five sensory-motor attributes.

    PubMed

    Fernandino, Leonardo; Humphries, Colin J; Seidenberg, Mark S; Gross, William L; Conant, Lisa L; Binder, Jeffrey R

    2015-09-01

    While major advances have been made in uncovering the neural processes underlying perceptual representations, our grasp of how the brain gives rise to conceptual knowledge remains relatively poor. Recent work has provided strong evidence that concepts rely, at least in part, on the same sensory and motor neural systems through which they were acquired, but it is still unclear whether the neural code for concept representation uses information about sensory-motor features to discriminate between concepts. In the present study, we investigate this question by asking whether an encoding model based on five semantic attributes directly related to sensory-motor experience - sound, color, visual motion, shape, and manipulation - can successfully predict patterns of brain activation elicited by individual lexical concepts. We collected ratings on the relevance of these five attributes to the meaning of 820 words, and used these ratings as predictors in a multiple regression model of the fMRI signal associated with the words in a separate group of participants. The five resulting activation maps were then combined by linear summation to predict the distributed activation pattern elicited by a novel set of 80 test words. The encoding model predicted the activation patterns elicited by the test words significantly better than chance. As expected, prediction was successful for concrete but not for abstract concepts. Comparisons between encoding models based on different combinations of attributes indicate that all five attributes contribute to the representation of concrete concepts. Consistent with embodied theories of semantics, these results show, for the first time, that the distributed activation pattern associated with a concept combines information about different sensory-motor attributes according to their respective relevance. Future research should investigate how additional features of phenomenal experience contribute to the neural representation of conceptual

  18. Subgenual PFC Activity Predicts Individual Differences in HPA Activity Across Different Contexts

    PubMed Central

    Jahn, Allison L.; Fox, Andrew S.; Abercrombie, Heather C.; Shelton, Steven E.; Oakes, Terrence R.; Davidson, Richard J.; Kalin, Ned H.

    2009-01-01

    Background Hypothalamic-pituitary-adrenal (HPA) system activation is adaptive in response to stress, and HPA dysregulation occurs in stress-related psychopathology. It is important to understand the mechanisms that modulate HPA output; yet, few studies have addressed the neural circuitry associated with HPA regulation in primates and humans. Using high-resolution [F-18]-fluoro-deoxyglucose (FDG) positron emission tomography (PET) in rhesus monkeys, we assessed the relation between individual differences in brain activity and HPA function across multiple contexts that varied in stressfulness. Methods Using a logical AND conjunctions analysis, we assessed cortisol and brain metabolic activity with FDG-PET in 35 adolescent rhesus monkeys exposed to two threat and two home-cage conditions. To test the robustness of our findings, we used similar methods in an archival data set. In this data set, brain metabolic activity and cortisol were assessed in 17 adolescent male rhesus monkeys that were exposed to three different stress-related contexts. Results Results from the two studies, revealed that subgenual PFC metabolism (Area 25/24) consistently predicted individual differences in plasma cortisol concentrations regardless of the context in which brain activity and cortisol were assessed. Conclusions These findings suggest that activation in subgenual PFC may be related to HPA output across a variety of contexts (including familiar settings and novel or threatening situations). Individuals prone to elevated subgenual PFC activity across multiple contexts may be individuals who consistently show heightened cortisol, and may be at risk for stress-related HPA dysregulation. PMID:19846063

  19. Efficient Method of Achieving Agreements between Individuals and Organizations about RFID Privacy

    NASA Astrophysics Data System (ADS)

    Cha, Shi-Cho

    This work presents novel technical and legal approaches that address privacy concerns for personal data in RFID systems. In recent years, to minimize the conflict between convenience and the privacy risk of RFID systems, organizations have been requested to disclose their policies regarding RFID activities, obtain customer consent, and adopt appropriate mechanisms to enforce these policies. However, current research on RFID typically focuses on enforcement mechanisms to protect personal data stored in RFID tags and prevent organizations from tracking user activity through information emitted by specific RFID tags. A missing piece is how organizations can obtain customers' consent efficiently and flexibly. This study recommends that organizations obtain licenses automatically or semi-automatically before collecting personal data via RFID technologies rather than deal with written consents. Such digitalized and standard licenses can be checked automatically to ensure that collection and use of personal data is based on user consent. While individuals can easily control who has licenses and license content, the proposed framework provides an efficient and flexible way to overcome the deficiencies in current privacy protection technologies for RFID systems.

  20. Using Subject Test Scores Efficiently to Predict Teacher Value-Added

    ERIC Educational Resources Information Center

    Lefgren, Lars; Sims, David

    2012-01-01

    This article develops a simple model of teacher value-added to show how efficient use of information across subjects can improve the predictive ability of value-added models. Using matched student-teacher data from North Carolina, we show that the optimal use of math and reading scores improves the fit of prediction models of overall future…

  1. Wandering in both mind and body: individual differences in mind wandering and inattention predict fidgeting.

    PubMed

    Carriere, Jonathan S A; Seli, Paul; Smilek, Daniel

    2013-03-01

    Anecdotal reports suggest that during periods of inattention or mind wandering, people tend to experience increased fidgeting. In four studies, we examined whether individual differences in the tendency to be inattentive and to mind wander in everyday life are related to the tendency to make spontaneous and involuntary movements (i.e., to fidget). To do so, we developed self-report measures of spontaneous and deliberate mind wandering, as well as a self-report scale to index fidgeting. In addition, we used several existing self-report measures of inattentiveness, attentional control, and memory failures. Across our studies, a series of multiple regression analyses indicated that fidgeting was uniquely predicted by inattentiveness and spontaneous mind wandering but not by other related factors, including deliberate mind wandering, attentional control, and memory failures. As a result, we suggest that only spontaneously wandering thoughts are related to a wandering body.

  2. Asymmetry in pay-off predicts how familiar individuals respond to one another.

    PubMed

    Granroth-Wilding, Hanna M V; Magurran, Anne E

    2013-06-23

    Familiarity influences individual decision-making in many vertebrate species. Here, we propose that familiarity modulates behaviour to different extents depending on the social context of the interaction. Specifically, the more that one player stands to gain relative to the other, the less important familiarity will be in influencing their responses to one another. We test this prediction using pairs of male guppies (Poecilia reticulata) in three competitive scenarios of increasing asymmetry in outcome to the two players: schooling under potential threat (similar outcomes), competing for a defensible food source (some asymmetry) and competing for a receptive female (strongly asymmetrical outcomes). Males show a graded response as asymmetry increases, with familiarity producing marked behavioural differences under potential threat, minor changes when competing for food, but none at all in competition for mating opportunities. This suggests that mutualistic benefits can arise as a by-product of selfish behaviour, supporting the role of pseudo-reciprocity in the evolution of cooperation. PMID:23576778

  3. Predicting Efficiency of Travel in Young, Visually Impaired Children from Their Other Spatial Skills.

    ERIC Educational Resources Information Center

    Hill, Anita; And Others

    1985-01-01

    To test ways of predicting how efficiently visually impaired children learn travel skills, a criteria checklist of spatial skills was developed for close-body space, local space, and geographical/travel space. Comparison was made between predictors of efficient learning including subjective ratings of teachers, personal qualities and factors of…

  4. Clinical implications of omics and systems medicine: focus on predictive and individualized treatment.

    PubMed

    Benson, M

    2016-03-01

    Many patients with common diseases do not respond to treatment. This is a key challenge to modern health care, which causes both suffering and enormous costs. One important reason for the lack of treatment response is that common diseases are associated with altered interactions between thousands of genes, in combinations that differ between subgroups of patients who do or do not respond to a given treatment. Such subgroups, or even distinct disease entities, have been described recently in asthma, diabetes, autoimmune diseases and cancer. High-throughput techniques (omics) allow identification and characterization of such subgroups or entities. This may have important clinical implications, such as identification of diagnostic markers for individualized medicine, as well as new therapeutic targets for patients who do not respond to existing drugs. For example, whole-genome sequencing may be applied to more accurately guide treatment of neurodevelopmental diseases, or to identify drugs specifically targeting mutated genes in cancer. A study published in 2015 showed that 28% of hepatocellular carcinomas contained mutated genes that potentially could be targeted by drugs already approved by the US Food and Drug Administration. A translational study, which is described in detail, showed how combined omics, computational, functional and clinical studies could identify and validate a novel diagnostic and therapeutic candidate gene in allergy. Another important clinical implication is the identification of potential diagnostic markers and therapeutic targets for predictive and preventative medicine. By combining computational and experimental methods, early disease regulators may be identified and potentially used to predict and treat disease before it becomes symptomatic. Systems medicine is an emerging discipline, which may contribute to such developments through combining omics with computational, functional and clinical studies. The aims of this review are to provide

  5. Clinical implications of omics and systems medicine: focus on predictive and individualized treatment.

    PubMed

    Benson, M

    2016-03-01

    Many patients with common diseases do not respond to treatment. This is a key challenge to modern health care, which causes both suffering and enormous costs. One important reason for the lack of treatment response is that common diseases are associated with altered interactions between thousands of genes, in combinations that differ between subgroups of patients who do or do not respond to a given treatment. Such subgroups, or even distinct disease entities, have been described recently in asthma, diabetes, autoimmune diseases and cancer. High-throughput techniques (omics) allow identification and characterization of such subgroups or entities. This may have important clinical implications, such as identification of diagnostic markers for individualized medicine, as well as new therapeutic targets for patients who do not respond to existing drugs. For example, whole-genome sequencing may be applied to more accurately guide treatment of neurodevelopmental diseases, or to identify drugs specifically targeting mutated genes in cancer. A study published in 2015 showed that 28% of hepatocellular carcinomas contained mutated genes that potentially could be targeted by drugs already approved by the US Food and Drug Administration. A translational study, which is described in detail, showed how combined omics, computational, functional and clinical studies could identify and validate a novel diagnostic and therapeutic candidate gene in allergy. Another important clinical implication is the identification of potential diagnostic markers and therapeutic targets for predictive and preventative medicine. By combining computational and experimental methods, early disease regulators may be identified and potentially used to predict and treat disease before it becomes symptomatic. Systems medicine is an emerging discipline, which may contribute to such developments through combining omics with computational, functional and clinical studies. The aims of this review are to provide

  6. Benchmarking Deep Networks for Predicting Residue-Specific Quality of Individual Protein Models in CASP11

    PubMed Central

    Liu, Tong; Wang, Yiheng; Eickholt, Jesse; Wang, Zheng

    2016-01-01

    Quality assessment of a protein model is to predict the absolute or relative quality of a protein model using computational methods before the native structure is available. Single-model methods only need one model as input and can predict the absolute residue-specific quality of an individual model. Here, we have developed four novel single-model methods (Wang_deep_1, Wang_deep_2, Wang_deep_3, and Wang_SVM) based on stacked denoising autoencoders (SdAs) and support vector machines (SVMs). We evaluated these four methods along with six other methods participating in CASP11 at the global and local levels using Pearson’s correlation coefficients and ROC analysis. As for residue-specific quality assessment, our four methods achieved better performance than most of the six other CASP11 methods in distinguishing the reliably modeled residues from the unreliable measured by ROC analysis; and our SdA-based method Wang_deep_1 has achieved the highest accuracy, 0.77, compared to SVM-based methods and our ensemble of an SVM and SdAs. However, we found that Wang_deep_2 and Wang_deep_3, both based on an ensemble of multiple SdAs and an SVM, performed slightly better than Wang_deep_1 in terms of ROC analysis, indicating that integrating an SVM with deep networks works well in terms of certain measurements. PMID:26763289

  7. Comparison of individual-based modeling and population approaches for prediction of foodborne pathogens growth.

    PubMed

    Augustin, Jean-Christophe; Ferrier, Rachel; Hezard, Bernard; Lintz, Adrienne; Stahl, Valérie

    2015-02-01

    Individual-based modeling (IBM) approach combined with the microenvironment modeling of vacuum-packed cold-smoked salmon was more effective to describe the variability of the growth of a few Listeria monocytogenes cells contaminating irradiated salmon slices than the traditional population models. The IBM approach was particularly relevant to predict the absence of growth in 25% (5 among 20) of artificially contaminated cold-smoked salmon samples stored at 8 °C. These results confirmed similar observations obtained with smear soft cheese (Ferrier et al., 2013). These two different food models were used to compare the IBM/microscale and population/macroscale modeling approaches in more global exposure and risk assessment frameworks taking into account the variability and/or the uncertainty of the factors influencing the growth of L. monocytogenes. We observed that the traditional population models significantly overestimate exposure and risk estimates in comparison to IBM approach when contamination of foods occurs with a low number of cells (<100 per serving). Moreover, the exposure estimates obtained with the population model were characterized by a great uncertainty. The overestimation was mainly linked to the ability of IBM to predict no growth situations rather than the consideration of microscale environment. On the other hand, when the aim of quantitative risk assessment studies is only to assess the relative impact of changes in control measures affecting the growth of foodborne bacteria, the two modeling approach gave similar results and the simplest population approach was suitable.

  8. Benchmarking Deep Networks for Predicting Residue-Specific Quality of Individual Protein Models in CASP11.

    PubMed

    Liu, Tong; Wang, Yiheng; Eickholt, Jesse; Wang, Zheng

    2016-01-01

    Quality assessment of a protein model is to predict the absolute or relative quality of a protein model using computational methods before the native structure is available. Single-model methods only need one model as input and can predict the absolute residue-specific quality of an individual model. Here, we have developed four novel single-model methods (Wang_deep_1, Wang_deep_2, Wang_deep_3, and Wang_SVM) based on stacked denoising autoencoders (SdAs) and support vector machines (SVMs). We evaluated these four methods along with six other methods participating in CASP11 at the global and local levels using Pearson's correlation coefficients and ROC analysis. As for residue-specific quality assessment, our four methods achieved better performance than most of the six other CASP11 methods in distinguishing the reliably modeled residues from the unreliable measured by ROC analysis; and our SdA-based method Wang_deep_1 has achieved the highest accuracy, 0.77, compared to SVM-based methods and our ensemble of an SVM and SdAs. However, we found that Wang_deep_2 and Wang_deep_3, both based on an ensemble of multiple SdAs and an SVM, performed slightly better than Wang_deep_1 in terms of ROC analysis, indicating that integrating an SVM with deep networks works well in terms of certain measurements.

  9. Caspase-6 activity predicts lower episodic memory ability in aged individuals.

    PubMed

    Ramcharitar, Jasmine; Afonso, Veronica M; Albrecht, Steffen; Bennett, David A; LeBlanc, Andrea C

    2013-07-01

    Caspase-6 (Casp6), a cysteinyl protease that induces axonal degeneration, is activated early in Alzheimer Disease (AD) brains. To determine whether Casp6 activation is responsible for early cognitive impairment, we investigated the abundance of Casp6 activity, paired helical filament-1 (PHF-1) phosphorylated Tau and amyloid beta peptide (Aβ) pathology by immunohistochemistry in the hippocampal formation of aged non-cognitively impaired (NCI) individuals. Casp6 activity was restricted to the entorhinal cortex (ERC) and CA1 regions of the hippocampus. Pathology scores were then correlated with cognitive scores obtained within 1 year of death. Regression analyses revealed that ERC and CA1 Casp6 activity were the main contributor to lower episodic memory performance, whereas ERC PHF-1 pathology predicted lower semantic and working memory performance. Aβ did not correlate with any of the cognitive tests. Because Casp6 activity and PHF-1 pathology are intimately associated with AD pathology and memory decline is an early event in AD, we conclude that Casp6 activity and PHF-1 immunoreactivity in ERC identifies aged individuals at risk for developing AD.

  10. Evidence for predictive validity of blood assays to evaluate individual radiosensitivity

    SciTech Connect

    Severin, Erhard . E-mail: severie@uni-muenster.de; Greve, Burkhard; Pascher, Elke; Wedemeyer, Niels; Hacker-Klom, Ursula; Silling, Gerda; Kienast, Joachim; Willich, Normann; Goehde, Wolfgang

    2006-01-01

    Purpose: An escalation in standard irradiation dose ensuring improved local tumor control is estimated, but this strategy would require the exclusion of the most sensitive individuals from treatment. Therefore, fast and reliable assays for prediction of the individual radiosensitivity are urgently required. Methods and Materials: Seven parameters in lymphocytes of 40 patients with leukemia were analyzed before, during, and after total body irradiation (TBI) and in vitro X-ray irradiation. These were: cell proliferation, nuclear damage, activation of cytokines, and numbers of total leukocytes of CD34+ hematopoietic blood stem cells and of CD4+ and CD8+ lymphocytes. Additionally, antioxidative capacity of blood plasma, uric acid, and hemoglobin levels were measured. Blood samples of 67 healthy donors were used as controls. Results: In vivo and in vitro irradiations showed comparable results. A dose-response relationship was found for most parameters. Three parameters were associated with severe acute oral mucositis (Grade 3 or 4 vs. Grade 0 to 2): leukocytes fewer than 6200/{mu}L after 4 Gy TBI, a rate of >19% lymphocytes with reduced DNA and protein content ('necroses') after 4 Gy in vitro irradiation, and a small antioxidative capacity in blood plasma (<0.68 mMol) after 8 Gy TBI. Conclusion: Three simple blood assays were associated with oral mucositis that are posed here hypothetically as an early symptom of enhanced radiosensitivity in leukemic patients: leukocyte count, damaged lymphocyte score, and the antioxidative capacity after exposure.

  11. Individual differences in social dominance orientation predict support for the use of cognitive ability tests.

    PubMed

    Kim, Anita; Berry, Christopher M

    2015-02-01

    This study investigates the personality processes involved in the debate surrounding the use of cognitive ability tests in college admissions. In Study 1, 108 undergraduates (Mage  = 18.88 years, 60 women, 80 Whites) completed measures of social dominance orientation (SDO), testing self-efficacy, and attitudes regarding the use of cognitive ability tests in college admissions; SAT/ACT scores were collected from the registrar. Sixty-seven undergraduates (Mage  = 19.06 years, 39 women, 49 Whites) completed the same measures in Study 2, along with measures of endorsement of commonly presented arguments about test use. In Study 3, 321 American adults (Mage  = 35.58 years, 180 women, 251 Whites) completed the same measures used in Study 2; half were provided with facts about race and validity issues surrounding cognitive ability tests. Individual differences in SDO significantly predicted support for the use of cognitive ability tests in all samples, after controlling for SAT/ACT scores and test self-efficacy and also among participants who read facts about cognitive ability tests. Moreover, arguments for and against test use mediated this effect. The present study sheds new light on an old debate by demonstrating that individual differences in beliefs about hierarchy play a key role in attitudes toward cognitive ability test use.

  12. Plasma oxytocin levels predict social cue recognition in individuals with schizophrenia.

    PubMed

    Strauss, Gregory P; Keller, William R; Koenig, James I; Gold, James M; Frost, Katherine H; Buchanan, Robert W

    2015-03-01

    Lower endogenous levels of the neuropeptide oxytocin may be an important biological predictor of social cognition impairments in schizophrenia (SZ). Prior studies have demonstrated that lower-level social cognitive processes (e.g., facial affect perception) are significantly associated with reduced plasma oxytocin levels in SZ; however, it is unclear whether higher-level social cognition, which requires inferential processes and knowledge not directly presented in the stimulus, is associated with endogenous oxytocin. The current study explored the association between endogenous oxytocin levels and lower- and higher-level social cognition in 40 individuals diagnosed with SZ and 22 demographically matched healthy controls (CN). All participants received the Social Cue Recognition Test (SCRT), which presents participants with videotaped interpersonal vignettes and subsequent true/false questions related to concrete or abstract aspects of social interactions in the vignettes. Results indicated that SZ had significantly higher plasma oxytocin concentrations than CN. SZ and CN did not differ on SCRT hits, but SZ had more false positives and lower sensitivity scores than CN. Higher plasma oxytocin levels were associated with better sensitivity scores for abstract items in CN and fewer false positives for concrete items in individuals with SZ. Findings indicate that endogenous oxytocin levels predict accurate encoding of lower-level socially relevant information in SZ. PMID:25673435

  13. Prediction and quantification of individual differences in susceptibility to simulator sickness in fixed-base simulators

    NASA Astrophysics Data System (ADS)

    Yoo, Young H.

    Simulator sickness in a fixed-base simulator is a form of visually-induced motion sickness. Visual-vestibular interaction on spatial orientation and postural control predicts that vection information in the visual stimuli triggers compensatory head sways to stabilize body orientation to perceived visual motion. Simulator sickness might result from perceptual conflicts caused by the visual-vestibular interaction in unusual environments (i.e., fixed-base simulators). Relationship between simulator sickness, vection, and compensatory head sways to perceived vection might help to quantify and predict presence and magnitude of simulator sickness in simulated environments. It was hypothesized that there was significant and positive relationship between sickness, vection, and compensatory head sways. Existence of individual differences was also possible, depending on individual sensitivity to vection. It was also hypothesized that females would experience more intense vection than males because females have wider periphery and shorter vection latencies. Correlations and the multiple linear regression analyses were performed to test the linear relationship between simulator sickness, vection, head sway, gender, and age. There was significant linear relationship between variables. It was concluded that vection and Y-velocity are significant predictors by itself and in interaction forms. Interaction between gender and vection, Y-velocity, and age in the regression function implied that gender difference is significant and gender is also a significant predictor of simulator sickness. Therefore, it was also concluded that there was significant gender difference in susceptibility to simulator sickness between males and females. General linear model also indicates that mean difference in magnitudes of vection, and Y-velocity and difference in gender and age have effects on the magnitude of simulator sickness. Time-course of vection implies that magnitude of vection increases as

  14. Probing photo-carrier collection efficiencies of individual silicon nanowire diodes on a wafer substrate

    NASA Astrophysics Data System (ADS)

    Schmitt, S. W.; Brönstrup, G.; Shalev, G.; Srivastava, S. K.; Bashouti, M. Y.; Döhler, G. H.; Christiansen, S. H.

    2014-06-01

    Vertically aligned silicon nanowire (SiNW) diodes are promising candidates for the integration into various opto-electronic device concepts for e.g. sensing or solar energy conversion. Individual SiNW p-n diodes have intensively been studied, but to date an assessment of their device performance once integrated on a silicon substrate has not been made. We show that using a scanning electron microscope (SEM) equipped with a nano-manipulator and an optical fiber feed-through for tunable (wavelength, power using a tunable laser source) sample illumination, the dark and illuminated current-voltage (I-V) curve of individual SiNW diodes on the substrate wafer can be measured. Surprisingly, the I-V-curve of the serially coupled system composed of SiNW/wafers is accurately described by an equivalent circuit model of a single diode and diode parameters like series and shunting resistivity, diode ideality factor and photocurrent can be retrieved from a fit. We show that the photo-carrier collection efficiency (PCE) of the integrated diode illuminated with variable wavelength and intensity light directly gives insight into the quality of the device design at the nanoscale. We find that the PCE decreases for high light intensities and photocurrent densities, due to the fact that considerable amounts of photo-excited carriers generated within the substrate lead to a decrease in shunting resistivity of the SiNW diode and deteriorate its rectification. The PCE decreases systematically for smaller wavelengths of visible light, showing the possibility of monitoring the effectiveness of the SiNW device surface passivation using the shown measurement technique. The integrated device was pre-characterized using secondary ion mass spectrometry (SIMS), TCAD simulations and electron beam induced current (EBIC) measurements to validate the properties of the characterized material at the single SiNW diode level.Vertically aligned silicon nanowire (SiNW) diodes are promising candidates for

  15. Probing photo-carrier collection efficiencies of individual silicon nanowire diodes on a wafer substrate.

    PubMed

    Schmitt, S W; Brönstrup, G; Shalev, G; Srivastava, S K; Bashouti, M Y; Döhler, G H; Christiansen, S H

    2014-07-21

    Vertically aligned silicon nanowire (SiNW) diodes are promising candidates for the integration into various opto-electronic device concepts for e.g. sensing or solar energy conversion. Individual SiNW p-n diodes have intensively been studied, but to date an assessment of their device performance once integrated on a silicon substrate has not been made. We show that using a scanning electron microscope (SEM) equipped with a nano-manipulator and an optical fiber feed-through for tunable (wavelength, power using a tunable laser source) sample illumination, the dark and illuminated current-voltage (I-V) curve of individual SiNW diodes on the substrate wafer can be measured. Surprisingly, the I-V-curve of the serially coupled system composed of SiNW/wafers is accurately described by an equivalent circuit model of a single diode and diode parameters like series and shunting resistivity, diode ideality factor and photocurrent can be retrieved from a fit. We show that the photo-carrier collection efficiency (PCE) of the integrated diode illuminated with variable wavelength and intensity light directly gives insight into the quality of the device design at the nanoscale. We find that the PCE decreases for high light intensities and photocurrent densities, due to the fact that considerable amounts of photo-excited carriers generated within the substrate lead to a decrease in shunting resistivity of the SiNW diode and deteriorate its rectification. The PCE decreases systematically for smaller wavelengths of visible light, showing the possibility of monitoring the effectiveness of the SiNW device surface passivation using the shown measurement technique. The integrated device was pre-characterized using secondary ion mass spectrometry (SIMS), TCAD simulations and electron beam induced current (EBIC) measurements to validate the properties of the characterized material at the single SiNW diode level.

  16. Overview of Heat Addition and Efficiency Predictions for an Advanced Stirling Convertor

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.; Reid, Terry; Schifer, Nicholas; Briggs, Maxwell

    2011-01-01

    Past methods of predicting net heat input needed to be validated. Validation effort pursued with several paths including improving model inputs, using test hardware to provide validation data, and validating high fidelity models. Validation test hardware provided direct measurement of net heat input for comparison to predicted values. Predicted value of net heat input was 1.7 percent less than measured value and initial calculations of measurement uncertainty were 2.1 percent (under review). Lessons learned during validation effort were incorporated into convertor modeling approach which improved predictions of convertor efficiency.

  17. Efficient design and inference for multistage randomized trials of individualized treatment policies.

    PubMed

    Dawson, Ree; Lavori, Philip W

    2012-01-01

    Clinical demand for individualized "adaptive" treatment policies in diverse fields has spawned development of clinical trial methodology for their experimental evaluation via multistage designs, building upon methods intended for the analysis of naturalistically observed strategies. Because often there is no need to parametrically smooth multistage trial data (in contrast to observational data for adaptive strategies), it is possible to establish direct connections among different methodological approaches. We show by algebraic proof that the maximum likelihood (ML) and optimal semiparametric (SP) estimators of the population mean of the outcome of a treatment policy and its standard error are equal under certain experimental conditions. This result is used to develop a unified and efficient approach to design and inference for multistage trials of policies that adapt treatment according to discrete responses. We derive a sample size formula expressed in terms of a parametric version of the optimal SP population variance. Nonparametric (sample-based) ML estimation performed well in simulation studies, in terms of achieved power, for scenarios most likely to occur in real studies, even though sample sizes were based on the parametric formula. ML outperformed the SP estimator; differences in achieved power predominately reflected differences in their estimates of the population mean (rather than estimated standard errors). Neither methodology could mitigate the potential for overestimated sample sizes when strong nonlinearity was purposely simulated for certain discrete outcomes; however, such departures from linearity may not be an issue for many clinical contexts that make evaluation of competitive treatment policies meaningful. PMID:21765180

  18. The Carbon_h-factor: predicting individuals' research impact at early stages of their career.

    PubMed

    Carbon, Claus-Christian

    2011-01-01

    Assessing an individual's research impact on the basis of a transparent algorithm is an important task for evaluation and comparison purposes. Besides simple but also inaccurate indices such as counting the mere number of publications or the accumulation of overall citations, and highly complex but also overwhelming full-range publication lists in their raw format, Hirsch (2005) introduced a single figure cleverly combining different approaches. The so-called h-index has undoubtedly become the standard in scientometrics of individuals' research impact (note: in the present paper I will always use the term "research impact" to describe the research performance as the logic of the paper is based on the h-index, which quantifies the specific "impact" of, e.g., researchers, but also because the genuine meaning of impact refers to quality as well). As the h-index reflects the number h of papers a researcher has published with at least h citations, the index is inherently positively biased towards senior level researchers. This might sometimes be problematic when predictive tools are needed for assessing young scientists' potential, especially when recruiting early career positions or equipping young scientists' labs. To be compatible with the standard h-index, the proposed index integrates the scientist's research age (Carbon_h-factor) into the h-index, thus reporting the average gain of h-index per year. Comprehensive calculations of the Carbon_h-factor were made for a broad variety of four research-disciplines (economics, neuroscience, physics and psychology) and for researchers performing on three high levels of research impact (substantial, outstanding and epochal) with ten researchers per category. For all research areas and output levels we obtained linear developments of the h-index demonstrating the validity of predicting one's later impact in terms of research impact already at an early stage of their career with the Carbon_h-factor being approx. 0.4, 0.8, and

  19. The Carbon_h-Factor: Predicting Individuals' Research Impact at Early Stages of Their Career

    PubMed Central

    Carbon, Claus-Christian

    2011-01-01

    Assessing an individual's research impact on the basis of a transparent algorithm is an important task for evaluation and comparison purposes. Besides simple but also inaccurate indices such as counting the mere number of publications or the accumulation of overall citations, and highly complex but also overwhelming full-range publication lists in their raw format, Hirsch (2005) introduced a single figure cleverly combining different approaches. The so-called h-index has undoubtedly become the standard in scientometrics of individuals' research impact (note: in the present paper I will always use the term “research impact” to describe the research performance as the logic of the paper is based on the h-index, which quantifies the specific “impact” of, e.g., researchers, but also because the genuine meaning of impact refers to quality as well). As the h-index reflects the number h of papers a researcher has published with at least h citations, the index is inherently positively biased towards senior level researchers. This might sometimes be problematic when predictive tools are needed for assessing young scientists' potential, especially when recruiting early career positions or equipping young scientists' labs. To be compatible with the standard h-index, the proposed index integrates the scientist's research age (Carbon_h-factor) into the h-index, thus reporting the average gain of h-index per year. Comprehensive calculations of the Carbon_h-factor were made for a broad variety of four research-disciplines (economics, neuroscience, physics and psychology) and for researchers performing on three high levels of research impact (substantial, outstanding and epochal) with ten researchers per category. For all research areas and output levels we obtained linear developments of the h-index demonstrating the validity of predicting one's later impact in terms of research impact already at an early stage of their career with the Carbon_h-factor being approx. 0.4, 0

  20. Prediction of response to preoperative chemoradiotherapy and establishment of individualized therapy in advanced rectal cancer.

    PubMed

    Nakao, Toshihiro; Iwata, Takashi; Hotchi, Masanori; Yoshikawa, Kozo; Higashijima, Jun; Nishi, Masaaki; Takasu, Chie; Eto, Shohei; Teraoku, Hiroki; Shimada, Mitsuo

    2015-10-01

    Preoperative chemoradiotherapy (CRT) has become the standard treatment for patients with locally advanced rectal cancer. However, no specific biomarker has been identified to predict a response to preoperative CRT. The aim of the present study was to assess the gene expression patterns of patients with advanced rectal cancer to predict their responses to preoperative CRT. Fifty-nine rectal cancer patients were subjected to preoperative CRT. Patients were randomly assigned to receive CRT with tegafur/gimeracil/oteracil (S-1 group, n=30) or tegafur-uracil (UFT group, n=29). Gene expression changes were studied with cDNA and miRNA microarray. The association between gene expression and response to CRT was evaluated. cDNA microarray showed that 184 genes were significantly differentially expressed between the responders and the non‑responders in the S-1 group. Comparatively, 193 genes were significantly differentially expressed in the responders in the UFT group. TBX18 upregulation was common to both groups whereas BTNL8, LOC375010, ADH1B, HRASLS2, LOC284232, GCNT3 and ALDH1A2 were significantly differentially lower in both groups when compared with the non-responders. Using miRNA microarray, we found that 7 and 16 genes were significantly differentially expressed between the responders and non-responders in the S-1 and UFT groups, respectively. miR-223 was significantly higher in the responders in the S-1 group and tended to be higher in the responders in the UFT group. The present study identified several genes likely to be useful for establishing individualized therapies for patients with rectal cancer.

  1. Phasic dopamine release induced by positive feedback predicts individual differences in reversal learning.

    PubMed

    Klanker, Marianne; Sandberg, Tessa; Joosten, Ruud; Willuhn, Ingo; Feenstra, Matthijs; Denys, Damiaan

    2015-11-01

    Striatal dopamine (DA) is central to reward-based learning. Less is known about the contribution of DA to the ability to adapt previously learned behavior in response to changes in the environment, such as a reversal of response-reward contingencies. We hypothesized that DA is involved in the rapid updating of response-reward information essential for successful reversal learning. We trained rats to discriminate between two levers, where lever availability was signaled by a non-discriminative cue. Pressing one lever was always rewarded, whereas the other lever was never rewarded. After reaching stable discrimination performance, a reversal was presented, so that the previously non-rewarded lever was now rewarded and vice versa. We used fast-scan cyclic voltammetry to monitor DA release in the ventromedial striatum. During discrimination performance (pre-reversal), cue presentation induced phasic DA release, whereas reward delivery did not. The opposite pattern was observed post-reversal: Striatal DA release emerged after reward delivery, while cue-induced release diminished. Trial-by-trial analysis showed rapid reinstatement of cue-induced DA release on trials immediately following initial correct responses. This effect of positive feedback was observed in animals that learned the reversal, but not in 'non-learners'. In contrast, neither pre-reversal responding and DA signaling, nor post-reversal DA signaling in response to negative feedback differed between learners and non-learners. Together, we show that phasic DA dynamics in the ventromedial striatum encoding reward-predicting cues are associated with positive feedback during reversal learning. Furthermore, these signals predict individual differences in learning that are not present prior to reversal, suggesting a distinct role for dopamine in the adaptation of previously learned behavior. PMID:26343836

  2. The Individualized Genetic Barrier Predicts Treatment Response in a Large Cohort of HIV-1 Infected Patients

    PubMed Central

    Beerenwinkel, Niko; Montazeri, Hesam; Schuhmacher, Heike; Knupfer, Patrick; von Wyl, Viktor; Furrer, Hansjakob; Battegay, Manuel; Hirschel, Bernard; Cavassini, Matthias; Vernazza, Pietro; Bernasconi, Enos; Yerly, Sabine; Böni, Jürg; Klimkait, Thomas; Cellerai, Cristina; Günthard, Huldrych F.

    2013-01-01

    The success of combination antiretroviral therapy is limited by the evolutionary escape dynamics of HIV-1. We used Isotonic Conjunctive Bayesian Networks (I-CBNs), a class of probabilistic graphical models, to describe this process. We employed partial order constraints among viral resistance mutations, which give rise to a limited set of mutational pathways, and we modeled phenotypic drug resistance as monotonically increasing along any escape pathway. Using this model, the individualized genetic barrier (IGB) to each drug is derived as the probability of the virus not acquiring additional mutations that confer resistance. Drug-specific IGBs were combined to obtain the IGB to an entire regimen, which quantifies the virus' genetic potential for developing drug resistance under combination therapy. The IGB was tested as a predictor of therapeutic outcome using between 2,185 and 2,631 treatment change episodes of subtype B infected patients from the Swiss HIV Cohort Study Database, a large observational cohort. Using logistic regression, significant univariate predictors included most of the 18 drugs and single-drug IGBs, the IGB to the entire regimen, the expert rules-based genotypic susceptibility score (GSS), several individual mutations, and the peak viral load before treatment change. In the multivariate analysis, the only genotype-derived variables that remained significantly associated with virological success were GSS and, with 10-fold stronger association, IGB to regimen. When predicting suppression of viral load below 400 cps/ml, IGB outperformed GSS and also improved GSS-containing predictors significantly, but the difference was not significant for suppression below 50 cps/ml. Thus, the IGB to regimen is a novel data-derived predictor of treatment outcome that has potential to improve the interpretation of genotypic drug resistance tests. PMID:24009493

  3. Neural activity tied to reading predicts individual differences in extended-text comprehension.

    PubMed

    Mossbridge, Julia A; Grabowecky, Marcia; Paller, Ken A; Suzuki, Satoru

    2013-01-01

    Reading comprehension depends on neural processes supporting the access, understanding, and storage of words over time. Examinations of the neural activity correlated with reading have contributed to our understanding of reading comprehension, especially for the comprehension of sentences and short passages. However, the neural activity associated with comprehending an extended text is not well-understood. Here we describe a current-source-density (CSD) index that predicts individual differences in the comprehension of an extended text. The index is the difference in CSD-transformed event-related potentials (ERPs) to a target word between two conditions: a comprehension condition with words from a story presented in their original order, and a scrambled condition with the same words presented in a randomized order. In both conditions participants responded to the target word, and in the comprehension condition they also tried to follow the story in preparation for a comprehension test. We reasoned that the spatiotemporal pattern of difference-CSDs would reflect comprehension-related processes beyond word-level processing. We used a pattern-classification method to identify the component of the difference-CSDs that accurately (88%) discriminated good from poor comprehenders. The critical CSD index was focused at a frontal-midline scalp site, occurred 400-500 ms after target-word onset, and was strongly correlated with comprehension performance. Behavioral data indicated that group differences in effort or motor preparation could not explain these results. Further, our CSD index appears to be distinct from the well-known P300 and N400 components, and CSD transformation seems to be crucial for distinguishing good from poor comprehenders using our experimental paradigm. Once our CSD index is fully characterized, this neural signature of individual differences in extended-text comprehension may aid the diagnosis and remediation of reading comprehension deficits.

  4. Neural activity tied to reading predicts individual differences in extended-text comprehension

    PubMed Central

    Mossbridge, Julia A.; Grabowecky, Marcia; Paller, Ken A.; Suzuki, Satoru

    2013-01-01

    Reading comprehension depends on neural processes supporting the access, understanding, and storage of words over time. Examinations of the neural activity correlated with reading have contributed to our understanding of reading comprehension, especially for the comprehension of sentences and short passages. However, the neural activity associated with comprehending an extended text is not well-understood. Here we describe a current-source-density (CSD) index that predicts individual differences in the comprehension of an extended text. The index is the difference in CSD-transformed event-related potentials (ERPs) to a target word between two conditions: a comprehension condition with words from a story presented in their original order, and a scrambled condition with the same words presented in a randomized order. In both conditions participants responded to the target word, and in the comprehension condition they also tried to follow the story in preparation for a comprehension test. We reasoned that the spatiotemporal pattern of difference-CSDs would reflect comprehension-related processes beyond word-level processing. We used a pattern-classification method to identify the component of the difference-CSDs that accurately (88%) discriminated good from poor comprehenders. The critical CSD index was focused at a frontal-midline scalp site, occurred 400–500 ms after target-word onset, and was strongly correlated with comprehension performance. Behavioral data indicated that group differences in effort or motor preparation could not explain these results. Further, our CSD index appears to be distinct from the well-known P300 and N400 components, and CSD transformation seems to be crucial for distinguishing good from poor comprehenders using our experimental paradigm. Once our CSD index is fully characterized, this neural signature of individual differences in extended-text comprehension may aid the diagnosis and remediation of reading comprehension deficits. PMID

  5. Energy-Efficient Integration of Continuous Context Sensing and Prediction into Smartwatches.

    PubMed

    Rawassizadeh, Reza; Tomitsch, Martin; Nourizadeh, Manouchehr; Momeni, Elaheh; Peery, Aaron; Ulanova, Liudmila; Pazzani, Michael

    2015-01-01

    As the availability and use of wearables increases, they are becoming a promising platform for context sensing and context analysis. Smartwatches are a particularly interesting platform for this purpose, as they offer salient advantages, such as their proximity to the human body. However, they also have limitations associated with their small form factor, such as processing power and battery life, which makes it difficult to simply transfer smartphone-based context sensing and prediction models to smartwatches. In this paper, we introduce an energy-efficient, generic, integrated framework for continuous context sensing and prediction on smartwatches. Our work extends previous approaches for context sensing and prediction on wrist-mounted wearables that perform predictive analytics outside the device. We offer a generic sensing module and a novel energy-efficient, on-device prediction module that is based on a semantic abstraction approach to convert sensor data into meaningful information objects, similar to human perception of a behavior. Through six evaluations, we analyze the energy efficiency of our framework modules, identify the optimal file structure for data access and demonstrate an increase in accuracy of prediction through our semantic abstraction method. The proposed framework is hardware independent and can serve as a reference model for implementing context sensing and prediction on small wearable devices beyond smartwatches, such as body-mounted cameras. PMID:26370997

  6. Energy-Efficient Integration of Continuous Context Sensing and Prediction into Smartwatches

    PubMed Central

    Rawassizadeh, Reza; Tomitsch, Martin; Nourizadeh, Manouchehr; Momeni, Elaheh; Peery, Aaron; Ulanova, Liudmila; Pazzani, Michael

    2015-01-01

    As the availability and use of wearables increases, they are becoming a promising platform for context sensing and context analysis. Smartwatches are a particularly interesting platform for this purpose, as they offer salient advantages, such as their proximity to the human body. However, they also have limitations associated with their small form factor, such as processing power and battery life, which makes it difficult to simply transfer smartphone-based context sensing and prediction models to smartwatches. In this paper, we introduce an energy-efficient, generic, integrated framework for continuous context sensing and prediction on smartwatches. Our work extends previous approaches for context sensing and prediction on wrist-mounted wearables that perform predictive analytics outside the device. We offer a generic sensing module and a novel energy-efficient, on-device prediction module that is based on a semantic abstraction approach to convert sensor data into meaningful information objects, similar to human perception of a behavior. Through six evaluations, we analyze the energy efficiency of our framework modules, identify the optimal file structure for data access and demonstrate an increase in accuracy of prediction through our semantic abstraction method. The proposed framework is hardware independent and can serve as a reference model for implementing context sensing and prediction on small wearable devices beyond smartwatches, such as body-mounted cameras. PMID:26370997

  7. Energy-Efficient Integration of Continuous Context Sensing and Prediction into Smartwatches.

    PubMed

    Rawassizadeh, Reza; Tomitsch, Martin; Nourizadeh, Manouchehr; Momeni, Elaheh; Peery, Aaron; Ulanova, Liudmila; Pazzani, Michael

    2015-09-08

    As the availability and use of wearables increases, they are becoming a promising platform for context sensing and context analysis. Smartwatches are a particularly interesting platform for this purpose, as they offer salient advantages, such as their proximity to the human body. However, they also have limitations associated with their small form factor, such as processing power and battery life, which makes it difficult to simply transfer smartphone-based context sensing and prediction models to smartwatches. In this paper, we introduce an energy-efficient, generic, integrated framework for continuous context sensing and prediction on smartwatches. Our work extends previous approaches for context sensing and prediction on wrist-mounted wearables that perform predictive analytics outside the device. We offer a generic sensing module and a novel energy-efficient, on-device prediction module that is based on a semantic abstraction approach to convert sensor data into meaningful information objects, similar to human perception of a behavior. Through six evaluations, we analyze the energy efficiency of our framework modules, identify the optimal file structure for data access and demonstrate an increase in accuracy of prediction through our semantic abstraction method. The proposed framework is hardware independent and can serve as a reference model for implementing context sensing and prediction on small wearable devices beyond smartwatches, such as body-mounted cameras.

  8. Quantification of individual fatty acids in bovine milk by infrared spectroscopy and chemometrics: understanding predictions of highly collinear reference variables.

    PubMed

    Eskildsen, C E; Rasmussen, M A; Engelsen, S B; Larsen, L B; Poulsen, N A; Skov, T

    2014-12-01

    Predicting individual fatty acids (FA) in bovine milk from Fourier transform infrared (FT-IR) measurements is desirable. However, such predictions may rely on covariance structures among individual FA and total fat content. These covariance structures may change with factors such as breed and feed, among others. The aim of this study was to estimate how spectral variation associated with total fat content and breed contributes to predictions of individual FA. This study comprised 890 bovine milk samples from 2 breeds (455 Holstein and 435 Jersey). Holstein samples were collected from 20 Danish dairy herds from October to December 2009; Jersey samples were collected from 22 Danish dairy herds from February to April 2010. All samples were from conventional herds and taken while cows were housed. Moreover, in a spiking experiment, FA (C14:0, C16:0, and C18:1 cis-9) were added (spiked) to a background of commercial skim milk to determine whether signals specific to those individual FA could be obtained from the FT-IR measurements. This study demonstrated that variation associated with total fat content and breed was responsible for successful FT-IR-based predictions of FA in the raw milk samples. This was confirmed in the spiking experiment, which showed that signals specific to individual FA could not be identified in FT-IR measurements when several FA were present in the same mixture. Hence, predicted concentrations of individual FA in milk rely on covariance structures with total fat content rather than absorption bands directly associated with individual FA. If covariance structures between FA and total fat used to calibrate partial least squares (PLS) models are not conserved in future samples, these samples will show incorrect and biased FA predictions. This was demonstrated by using samples of one breed to calibrate and samples of the other breed to validate PLS models for individual FA. The 2 breeds had different covariance structures between individual FA and

  9. Resolving Anomalies in Predicting Electrokinetic Energy Conversion Efficiencies of Nanofluidic Devices

    NASA Astrophysics Data System (ADS)

    Majumder, Sagardip; Dhar, Jayabrata; Chakraborty, Suman

    2015-10-01

    We devise a new approach for capturing complex interfacial interactions over reduced length scales, towards predicting electrokinetic energy conversion efficiencies of nanofluidic devices. By embedding several aspects of intermolecular interactions in continuum based formalism, we show that our simple theory becomes capable of representing complex interconnections between electro-mechanics and hydrodynamics over reduced length scales. The predictions from our model are supported by reported experimental data, and are in excellent quantitative agreement with molecular dynamics simulations. The present model, thus, may be employed to rationalize the discrepancies between low energy conversion efficiencies of nanofluidic channels that have been realized from experiments, and the impractically high energy conversion efficiencies that have been routinely predicted by the existing theories.

  10. Resolving Anomalies in Predicting Electrokinetic Energy Conversion Efficiencies of Nanofluidic Devices

    PubMed Central

    Majumder, Sagardip; Dhar, Jayabrata; Chakraborty, Suman

    2015-01-01

    We devise a new approach for capturing complex interfacial interactions over reduced length scales, towards predicting electrokinetic energy conversion efficiencies of nanofluidic devices. By embedding several aspects of intermolecular interactions in continuum based formalism, we show that our simple theory becomes capable of representing complex interconnections between electro-mechanics and hydrodynamics over reduced length scales. The predictions from our model are supported by reported experimental data, and are in excellent quantitative agreement with molecular dynamics simulations. The present model, thus, may be employed to rationalize the discrepancies between low energy conversion efficiencies of nanofluidic channels that have been realized from experiments, and the impractically high energy conversion efficiencies that have been routinely predicted by the existing theories. PMID:26437925

  11. Relationship among performance, carcass, and feed efficiency characteristics, and their ability to predict economic value in the feedlot.

    PubMed

    Retallick, K M; Faulkner, D B; Rodriguez-Zas, S L; Nkrumah, J D; Shike, D W

    2013-12-01

    A 4-yr study was conducted using 736 steers of known Angus, Simmental, or Simmental × Angus genetics to determine performance, carcass, and feed efficiency factors that explained variation in economic performance. Steers were pen fed and individual DMI was recorded using a GrowSafe automated feeding system (GrowSafe Systems Ltd., Airdrie, Alberta, Canada). Steers consumed a similar diet and received similar management each year. The objectives of this study were to: 1) determine current economic value of feed efficiency and 2) identify performance, carcass, and feed efficiency characteristics that predict: carcass value, profit, cost of gain, and feed costs. Economic data used were from 2011 values. Feed efficiency values investigated were: feed conversion ratio (FCR; feed to gain), residual feed intake (RFI), residual BW gain (RG), and residual intake and BW gain (RIG). Dependent variables were carcass value ($/steer), profit ($/steer), feed costs ($/steer • d(-1)), and cost of gain ($/kg). Independent variables were year, DMI, ADG, HCW, LM area, marbling, yield grade, dam breed, and sire breed. A 10% improvement in RG (P < 0.05) yielded the lowest cost of gain at $0.09/kg and highest carcass value at $17.92/steer. Carcass value increased (P < 0.05) as feed efficiency improved for FCR, RG, and RIG. Profit increased with a 10% improvement in feed efficiency (P < 0.05) with FCR at $34.65/steer, RG at $31.21/steer, RIG at $21.66/steer, and RFI at $11.47/steer. The carcass value prediction model explained 96% of the variation among carcasses and included HCW, marbling score, and yield grade. Average daily gain, marbling score, yield grade, DMI, HCW, and year born constituted 81% of the variation for prediction of profit. Eighty-five percent of the variation in cost of gain was explained by ADG, DMI, HCW, and year. Prediction equations were developed that excluded ADG and DMI, and included feed efficiency values. Using these equations, cost of gain was explained

  12. Individual changes in clozapine levels after smoking cessation: results and a predictive model.

    PubMed

    Meyer, J M

    2001-12-01

    Published reports document 20-40% lower mean serum clozapine concentrations in smokers compared with nonsmokers due to enzyme induction. Despite the increase in nonsmoking psychiatric facilities in the United States, previous studies have not tracked individual changes in serum clozapine levels after smoking cessation. Clozapine level changes were analyzed in 11 patients at Oregon State Hospital who were on stable clozapine doses, before and after implementation of a hospital-wide nonsmoking policy. A mean increase in clozapine levels of 71.9% (442.4 ng/ml +/- 598.8 ng/ml) occurred upon smoking cessation (p < .034) from a baseline level of 550.2 ng/ml (+/- 160.18 ng/ml). One serious adverse event, aspiration pneumonia, was associated with a nonsmoking serum clozapine level of 3066 ng/ml. Elimination of statistically extreme results generated a mean increase of 57.4 % or 284.1 ng/ml (+/- 105.2 ng/ml) for the remaining cases (p < .001) and permitted construction of a linear model which explains 80.9% of changes in clozapine levels upon smoking cessation (F = 34.9;p = .001): clozapine level as nonsmoker = 45.3 + 1.474 (clozapine level as smoker). These findings suggest that significant increases in clozapine levels upon smoking cessation may be predicted by use of a model. Those with high baseline levels should be monitored for serious adverse events. PMID:11763003

  13. Individual differences in attributional style but not in interoceptive sensitivity, predict subjective estimates of action intention

    PubMed Central

    Penton, Tegan; Thierry, Guillaume L.; Davis, Nick J.

    2014-01-01

    The debate on the existence of free will is on-going. Seminal findings by Libet et al. (1983) demonstrate that subjective awareness of a voluntary urge to act (the W-judgment) occurs before action execution. Libet’s paradigm requires participants to perform voluntary actions while watching a clock hand rotate. On response trials, participants make a retrospective judgment related to awareness of their urge to act. This research investigates the relationship between individual differences in performance on the Libet task and self-awareness. We examined the relationship between W-judgment, attributional style (AS; a measure of perceived control) and interoceptive sensitivity (IS; awareness of stimuli originating from one’s body; e.g., heartbeats). Thirty participants completed the AS questionnaire (ASQ), a heartbeat estimation task (IS), and the Libet paradigm. The ASQ score significantly predicted performance on the Libet task, while IS did not – more negative ASQ scores indicated larger latency between W-judgment and action execution. A significant correlation was also observed between ASQ score and IS. This is the first research to report a relationship between W-judgment and AS and should inform the future use of electroencephalography (EEG) to investigate the relationship between AS, W-judgment and RP onset. Our findings raise questions surrounding the importance of one’s perceived control in determining the point of conscious intention to act. Furthermore, we demonstrate possible negative implications associated with a longer period between conscious awareness and action execution. PMID:25191254

  14. Accuracy of genomic predictions for feed efficiency traits of beef cattle using 50K and imputed HD genotypes.

    PubMed

    Lu, D; Akanno, E C; Crowley, J J; Schenkel, F; Li, H; De Pauw, M; Moore, S S; Wang, Z; Li, C; Stothard, P; Plastow, G; Miller, S P; Basarab, J A

    2016-04-01

    The accuracy of genomic predictions can be used to assess the utility of dense marker genotypes for genetic improvement of beef efficiency traits. This study was designed to test the impact of genomic distance between training and validation populations, training population size, statistical methods, and density of genetic markers on prediction accuracy for feed efficiency traits in multibreed and crossbred beef cattle. A total of 6,794 beef cattle data collated from various projects and research herds across Canada were used. Illumina BovineSNP50 (50K) and imputed Axiom Genome-Wide BOS 1 Array (HD) genotypes were available for all animals. The traits studied were DMI, ADG, and residual feed intake (RFI). Four validation groups of 150 animals each, including Angus (AN), Charolais (CH), Angus-Hereford crosses (ANHH), and a Charolais-based composite (TX) were created by considering the genomic distance between pairs of individuals in the validation groups. Each validation group had 7 corresponding training groups of increasing sizes ( = 1,000, 1,999, 2,999, 3,999, 4,999, 5,998, and 6,644), which also represent increasing average genomic distance between pairs of individuals in the training and validations groups. Prediction of genomic estimated breeding values (GEBV) was performed using genomic best linear unbiased prediction (GBLUP) and Bayesian method C (BayesC). The accuracy of genomic predictions was defined as the Pearson's correlation between adjusted phenotype and GEBV (), unless otherwise stated. Using 50K genotypes, the highest average achieved in purebreds (AN, CH) was 0.41 for DMI, 0.34 for ADG, and 0.35 for RFI, whereas in crossbreds (ANHH, TX) it was 0.38 for DMI, 0.21 for ADG, and 0.25 for RFI. Similarly, when imputed HD genotypes were applied in purebreds (AN, CH), the highest average was 0.14 for DMI, 0.15 for ADG, and 0.14 for RFI, whereas in crossbreds (ANHH, TX) it was 0.38 for DMI, 0.22 for ADG, and 0.24 for RFI. The of GBLUP predictions were

  15. Evaluation of the efficiency of artificial neural networks for genetic value prediction.

    PubMed

    Silva, G N; Tomaz, R S; Sant'Anna, I C; Carneiro, V Q; Cruz, C D; Nascimento, M

    2016-01-01

    Artificial neural networks have shown great potential when applied to breeding programs. In this study, we propose the use of artificial neural networks as a viable alternative to conventional prediction methods. We conduct a thorough evaluation of the efficiency of these networks with respect to the prediction of breeding values. Therefore, we considered eight simulated scenarios, and for the purpose of genetic value prediction, seven statistical parameters in addition to the phenotypic mean in a network designed as a multilayer perceptron. After an evaluation of different network configurations, the results demonstrated the superiority of neural networks compared to estimation procedures based on linear models, and indicated high predictive accuracy and network efficiency. PMID:27051007

  16. The potential of Fourier transform infrared spectroscopy of milk samples to predict energy intake and efficiency in dairy cows.

    PubMed

    McParland, S; Berry, D P

    2016-05-01

    Knowledge of animal-level and herd-level energy intake, energy balance, and feed efficiency affect day-to-day herd management strategies; information on these traits at an individual animal level is also useful in animal breeding programs. A paucity of data (especially at the individual cow level), of feed intake in particular, hinders the inclusion of such attributes in herd management decision-support tools and breeding programs. Dairy producers have access to an individual cow milk sample at least once daily during lactation, and consequently any low-cost phenotyping strategy should consider exploiting measureable properties in this biological sample, reflecting the physiological status and performance of the cow. Infrared spectroscopy is the study of the interaction of an electromagnetic wave with matter and it is used globally to predict milk quality parameters on routinely acquired individual cow milk samples and bulk tank samples. Thus, exploiting infrared spectroscopy in next-generation phenotyping will ensure potentially rapid application globally with a negligible additional implementation cost as the infrastructure already exists. Fourier-transform infrared spectroscopy (FTIRS) analysis is already used to predict milk fat and protein concentrations, the ratio of which has been proposed as an indicator of energy balance. Milk FTIRS is also able to predict the concentration of various fatty acids in milk, the composition of which is known to change when body tissue is mobilized; that is, when the cow is in negative energy balance. Energy balance is mathematically very similar to residual energy intake (REI), a suggested measure of feed efficiency. Therefore, the prediction of energy intake, energy balance, and feed efficiency (i.e., REI) from milk FTIRS seems logical. In fact, the accuracy of predicting (i.e., correlation between predicted and actual values; root mean square error in parentheses) energy intake, energy balance, and REI from milk FTIRS in

  17. Improving Computational Efficiency of Prediction in Model-Based Prognostics Using the Unscented Transform

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew John; Goebel, Kai Frank

    2010-01-01

    Model-based prognostics captures system knowledge in the form of physics-based models of components, and how they fail, in order to obtain accurate predictions of end of life (EOL). EOL is predicted based on the estimated current state distribution of a component and expected profiles of future usage. In general, this requires simulations of the component using the underlying models. In this paper, we develop a simulation-based prediction methodology that achieves computational efficiency by performing only the minimal number of simulations needed in order to accurately approximate the mean and variance of the complete EOL distribution. This is performed through the use of the unscented transform, which predicts the means and covariances of a distribution passed through a nonlinear transformation. In this case, the EOL simulation acts as that nonlinear transformation. In this paper, we review the unscented transform, and describe how this concept is applied to efficient EOL prediction. As a case study, we develop a physics-based model of a solenoid valve, and perform simulation experiments to demonstrate improved computational efficiency without sacrificing prediction accuracy.

  18. Computational Efficient Upscaling Methodology for Predicting Thermal Conductivity of Nuclear Waste forms

    SciTech Connect

    Li, Dongsheng; Sun, Xin; Khaleel, Mohammad A.

    2011-09-28

    This study evaluated different upscaling methods to predict thermal conductivity in loaded nuclear waste form, a heterogeneous material system. The efficiency and accuracy of these methods were compared. Thermal conductivity in loaded nuclear waste form is an important property specific to scientific researchers, in waste form Integrated performance and safety code (IPSC). The effective thermal conductivity obtained from microstructure information and local thermal conductivity of different components is critical in predicting the life and performance of waste form during storage. How the heat generated during storage is directly related to thermal conductivity, which in turn determining the mechanical deformation behavior, corrosion resistance and aging performance. Several methods, including the Taylor model, Sachs model, self-consistent model, and statistical upscaling models were developed and implemented. Due to the absence of experimental data, prediction results from finite element method (FEM) were used as reference to determine the accuracy of different upscaling models. Micrographs from different loading of nuclear waste were used in the prediction of thermal conductivity. Prediction results demonstrated that in term of efficiency, boundary models (Taylor and Sachs model) are better than self consistent model, statistical upscaling method and FEM. Balancing the computation resource and accuracy, statistical upscaling is a computational efficient method in predicting effective thermal conductivity for nuclear waste form.

  19. A biostatistical study into the efficiency of individualism using nonisotopic chemiluminescent-enhanced NICE multilocus DNA probes.

    PubMed

    Hau, P P; Watt, E H; Hau, C M

    1997-10-01

    The efficiency of individualisation using nonisotopic chemiluminescent- enhanced probes (NICE) was investigated by analysing DNA fingerprints obtained from 190 unrelated Caucasians. Novel analysis of the scoring procedure enabled us to include the comparison of 585 pairs of samples for each of two probes. When the results of NICE probes 33.6 and 33.15 were combined, the mean percentage band share between two unrelated individuals was 16.8% and the mean number of bands identified in an individual DNA fingerprint was 54.8. Results were compared with those obtained using isotopically labelled probes and suggest that the two labelling systems gave similar efficiencies for differentiating between individuals. Analysis of DNA fingerprints from 37 family trios (mother, child and father groups) gave a mutation rate of 0.10% when using NICE probes. The two labelling systems compared were equally efficient in establishing family relationships.

  20. Efficient, Adaptive Clinical Validation of Predictive Biomarkers in Cancer Therapeutic Development.

    PubMed

    Beckman, Robert A; Chen, Cong

    2015-01-01

    Predictive biomarkers, defined as biomarkers that can be used to identify patient populations who will optimally benefit from therapy, are an important part of the future of oncology. They have the potential to reduce the size and cost of clinical development programs for oncology therapy, while increasing their probability of success and the ultimate value of cancer medicines. But predictive biomarkers do not always work, and under these circumstances they add cost, complexity, and time to drug development. This chapter describes Phase 2 and 3 development methods which efficiently and adaptively evaluate the ability of the biomarker to predict clinical outcomes. In the end, the biomarker is emphasized to the extent that it is actually predictive. This allows clinical cancer drug developers to manage uncertainty in the validity of biomarkers, leading to maximal value for predictive biomarkers and their associated oncology therapies.

  1. Relationship Status and Relationship Instability, but Not Dominance, Predict Individual Differences in Baseline Cortisol Levels

    PubMed Central

    Maestripieri, Dario; Klimczuk, Amanda C. E.; Seneczko, Marianne; Traficonte, Daniel M.; Wilson, M. Claire

    2013-01-01

    We investigated variation in baseline cortisol levels in relation to relationship status (single or in a relationship), relationship characteristics (length, stability, presence or absence of clear dominance), or individual attributes (dominant or subordinate status, relative physical attractiveness, relationship worries). Study participants were 77 men and 75 women aged between 18 and 38 years. Individuals in romantic relationships had lower cortisol levels than singles. Individuals of African ethnicity, however, showed the opposite pattern. Individuals who perceived their relationship to be highly unstable had higher cortisol levels. Aside from African-Americans, married individuals reported the lowest relationship instability and the lowest cortisol levels, followed by individuals in long-term relationships, and by individuals in short-term relationships. The presence or absence of clear dominance in the relationship, dominance status, or relationship worries did not affect cortisol levels. Therefore relationship status and relationship instability were better predictors of variation in cortisol (presumably through stress-related mechanisms) than individual attributes. PMID:24358324

  2. HBV-DNA levels predict overall mortality in HIV/HBV coinfected individuals.

    PubMed

    Nikolopoulos, Georgios K; Paraskevis, Dimitrios; Psichogiou, Mina; Hatzakis, Angelos

    2016-03-01

    The coinfection of Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) has been associated with increased death rates. However, the relevant research has mostly relied on serologic HBV testing [HBV surface antigen (HBsAg)]. The aim of this work was to explore the relationship of HBV viraemia with overall mortality among HIV/HBV coinfected individuals. The analysis included 1,609 HIV seropositives of a previously described cohort (1984-2003) with limited exposure to tenofovir (12%) and a median follow-up of approximately 5 years. Those with persistent expression of HBsAg were further tested for HBV-DNA. The data were analyzed using Poisson regression models. Totally, 101 participants were chronic carriers of HBsAg (6.28%). Of these, 81 were tested for HBV-DNA. The median HBV-DNA levels were 3.81 log (base-10) International Units (IU)/ml. A third (31%) of those tested for HBV-DNA had received tenofovir. Before developing acquired immune deficiency syndrome (AIDS), the adjusted incidence rate ratio (IRR) for all-cause mortality of coinfected patients with HBV viraemia above the median value versus the HIV monoinfected group was 3.44 [95% confidence interval (CI): 1.05-11.27]. Multivariable regressions in the coinfected group only (n = 81) showed that one log-10 increase in HBV-DNA levels was associated with an elevated risk for death (IRR: 1.24, 95%CI: 1.03-1.49). HBV-DNA levels predict overall mortality in the setting of HIV/HBV coinfection, especially during the period before developing AIDS, and could thus help prioritize needs and determine the frequency of medical monitoring.

  3. Studying Individual Differences in Predictability with Gamma Regression and Nonlinear Multilevel Models

    ERIC Educational Resources Information Center

    Culpepper, Steven Andrew

    2010-01-01

    Statistical prediction remains an important tool for decisions in a variety of disciplines. An equally important issue is identifying factors that contribute to more or less accurate predictions. The time series literature includes well developed methods for studying predictability and volatility over time. This article develops…

  4. Individually assessed boldness predicts Perca fluviatilis behaviour in shoals, but is not associated with the capture order or angling method.

    PubMed

    Kekäläinen, J; Podgorniak, T; Puolakka, T; Hyvärinen, P; Vainikka, A

    2014-11-01

    Selectivity of recreational angling on fish behaviour was studied by examining whether capture order or lure type (natural v. artificial bait) in ice-fishing could explain behavioural variation among perch Perca fluviatilis individuals. It was also tested if individually assessed personality predicts fish behaviour in groups, in the presence of natural predators. Perca fluviatilis showed individually repeatable behaviour both in individual and in group tests. Capture order, capture method, condition factor or past growth rate did not explain variation in individual behaviour. Individually determined boldness as well as fish size, however, were positively associated with first entrance to the predator zone (i.e. initial risk taking) in group behaviour tests. Individually determined boldness also explained long-term activity and total time spent in the vicinity of predators in the group. These findings suggest that individual and laboratory-based boldness tests predict boldness of P. fluviatilis in also ecologically relevant conditions, i.e. in shoals and in the presence of natural predators. The present results, however, also indicate that the above-mentioned two angling methods may not be selective for certain behavioural types in comparison to each other. PMID:25270290

  5. Both Nearest Neighbours and Long-term Affiliates Predict Individual Locations During Collective Movement in Wild Baboons.

    PubMed

    Farine, Damien R; Strandburg-Peshkin, Ariana; Berger-Wolf, Tanya; Ziebart, Brian; Brugere, Ivan; Li, Jia; Crofoot, Margaret C

    2016-06-13

    In many animal societies, groups of individuals form stable social units that are shaped by well-delineated dominance hierarchies and a range of affiliative relationships. How do socially complex groups maintain cohesion and achieve collective movement? Using high-resolution GPS tracking of members of a wild baboon troop, we test whether collective movement in stable social groups is governed by interactions among local neighbours (commonly found in groups with largely anonymous memberships), social affiliates, and/or by individuals paying attention to global group structure. We construct candidate movement prediction models and evaluate their ability to predict the future trajectory of focal individuals. We find that baboon movements are best predicted by 4 to 6 neighbours. While these are generally individuals' nearest neighbours, we find that baboons have distinct preferences for particular neighbours, and that these social affiliates best predict individual location at longer time scales (>10 minutes). Our results support existing theoretical and empirical studies highlighting the importance of local rules in driving collective outcomes, such as collective departures, in primates. We extend previous studies by elucidating the rules that maintain cohesion in baboons 'on the move', as well as the different temporal scales of social interactions that are at play.

  6. Both Nearest Neighbours and Long-term Affiliates Predict Individual Locations During Collective Movement in Wild Baboons.

    PubMed

    Farine, Damien R; Strandburg-Peshkin, Ariana; Berger-Wolf, Tanya; Ziebart, Brian; Brugere, Ivan; Li, Jia; Crofoot, Margaret C

    2016-01-01

    In many animal societies, groups of individuals form stable social units that are shaped by well-delineated dominance hierarchies and a range of affiliative relationships. How do socially complex groups maintain cohesion and achieve collective movement? Using high-resolution GPS tracking of members of a wild baboon troop, we test whether collective movement in stable social groups is governed by interactions among local neighbours (commonly found in groups with largely anonymous memberships), social affiliates, and/or by individuals paying attention to global group structure. We construct candidate movement prediction models and evaluate their ability to predict the future trajectory of focal individuals. We find that baboon movements are best predicted by 4 to 6 neighbours. While these are generally individuals' nearest neighbours, we find that baboons have distinct preferences for particular neighbours, and that these social affiliates best predict individual location at longer time scales (>10 minutes). Our results support existing theoretical and empirical studies highlighting the importance of local rules in driving collective outcomes, such as collective departures, in primates. We extend previous studies by elucidating the rules that maintain cohesion in baboons 'on the move', as well as the different temporal scales of social interactions that are at play. PMID:27292778

  7. Predicting the effects of human developments on individual dolphins to understand potential long-term population consequences.

    PubMed

    Pirotta, Enrico; Harwood, John; Thompson, Paul M; New, Leslie; Cheney, Barbara; Arso, Monica; Hammond, Philip S; Donovan, Carl; Lusseau, David

    2015-11-01

    Human activities that impact wildlife do not necessarily remove individuals from populations. They may also change individual behaviour in ways that have sublethal effects. This has driven interest in developing analytical tools that predict the population consequences of short-term behavioural responses. In this study, we incorporate empirical information on the ecology of a population of bottlenose dolphins into an individual-based model that predicts how individuals' behavioural dynamics arise from their underlying motivational states, as well as their interaction with boat traffic and dredging activities. We simulate the potential effects of proposed coastal developments on this population and predict that the operational phase may affect animals' motivational states. For such results to be relevant for management, the effects on individuals' vital rates also need to be quantified. We investigate whether the relationship between an individual's exposure and the survival of its calves can be directly estimated using a Bayesian multi-stage model for calf survival. The results suggest that any effect on calf survival is probably small and that a significant relationship could only be detected in large, closely studied populations. Our work can be used to guide management decisions, accelerate the consenting process for coastal and offshore developments and design targeted monitoring. PMID:26511044

  8. Individual differences in children's innovative problem-solving are not predicted by divergent thinking or executive functions

    PubMed Central

    2016-01-01

    Recent studies of children's tool innovation have revealed that there is variation in children's success in middle-childhood. In two individual differences studies, we sought to identify personal characteristics that might predict success on an innovation task. In Study 1, we found that although measures of divergent thinking were related to each other they did not predict innovation success. In Study 2, we measured executive functioning including: inhibition, working memory, attentional flexibility and ill-structured problem-solving. None of these measures predicted innovation, but, innovation was predicted by children's performance on a receptive vocabulary scale that may function as a proxy for general intelligence. We did not find evidence that children's innovation was predicted by specific personal characteristics. PMID:26926280

  9. Both Nearest Neighbours and Long-term Affiliates Predict Individual Locations During Collective Movement in Wild Baboons

    PubMed Central

    Farine, Damien R.; Strandburg-Peshkin, Ariana; Berger-Wolf, Tanya; Ziebart, Brian; Brugere, Ivan; Li, Jia; Crofoot, Margaret C.

    2016-01-01

    In many animal societies, groups of individuals form stable social units that are shaped by well-delineated dominance hierarchies and a range of affiliative relationships. How do socially complex groups maintain cohesion and achieve collective movement? Using high-resolution GPS tracking of members of a wild baboon troop, we test whether collective movement in stable social groups is governed by interactions among local neighbours (commonly found in groups with largely anonymous memberships), social affiliates, and/or by individuals paying attention to global group structure. We construct candidate movement prediction models and evaluate their ability to predict the future trajectory of focal individuals. We find that baboon movements are best predicted by 4 to 6 neighbours. While these are generally individuals’ nearest neighbours, we find that baboons have distinct preferences for particular neighbours, and that these social affiliates best predict individual location at longer time scales (>10 minutes). Our results support existing theoretical and empirical studies highlighting the importance of local rules in driving collective outcomes, such as collective departures, in primates. We extend previous studies by elucidating the rules that maintain cohesion in baboons ‘on the move’, as well as the different temporal scales of social interactions that are at play. PMID:27292778

  10. What Predicts the Effectiveness of Foreign-Language Pronunciation Instruction? Investigating the Role of Perception and Other Individual Differences

    ERIC Educational Resources Information Center

    Kissling, Elizabeth M.

    2014-01-01

    This study investigated second language (L2) learners' perception of L2 sounds as an individual difference that predicted their improvement in pronunciation after receiving instruction. Learners were given explicit pronunciation instruction in a series of modules added to their Spanish as a foreign language curriculum and were then tested on…

  11. Developmental Trajectories in Toddlers' Self-Restraint Predict Individual Differences in Executive Functions 14 Years Later: A Behavioral Genetic Analysis

    ERIC Educational Resources Information Center

    Friedman, Naomi P.; Miyake, Akira; Robinson, JoAnn L.; Hewitt, John K.

    2011-01-01

    We examined whether self-restraint in early childhood predicted individual differences in 3 executive functions (EFs; inhibiting prepotent responses, updating working memory, and shifting task sets) in late adolescence in a sample of approximately 950 twins. At ages 14, 20, 24, and 36 months, the children were shown an attractive toy and told not…

  12. The predictive value of arterial stiffness on major adverse cardiovascular events in individuals with mildly impaired renal function

    PubMed Central

    Han, Jie; Wang, Xiaona; Ye, Ping; Cao, Ruihua; Yang, Xu; Xiao, Wenkai; Zhang, Yun; Bai, Yongyi; Wu, Hongmei

    2016-01-01

    Objectives Despite growing evidence that arterial stiffness has important predictive value for cardiovascular disease in patients with advanced stages of chronic kidney disease, the predictive significance of arterial stiffness in individuals with mildly impaired renal function has not been established. The aim of this study was to evaluate the predictive value of arterial stiffness on cardiovascular disease in this specific population. Materials and methods We analyzed measurements of arterial stiffness (carotid–femoral pulse-wave velocity [cf-PWV]) and the incidence of major adverse cardiovascular events (MACEs) in 1,499 subjects from a 4.8-year longitudinal study. Results A multivariate Cox proportional-hazard regression analysis showed that in individuals with normal renal function (estimated glomerular filtration rate [eGFR] ≥90 mL/min/1.73 m2), the baseline cf-PWV was not associated with occurrence of MACEs (hazard ratio 1.398, 95% confidence interval 0.748–2.613; P=0.293). In individuals with mildly impaired renal function (eGFR <90 mL/min/1.73 m2), a higher baseline cf-PWV level was associated with a higher risk of MACEs (hazard ratio 2.334, 95% confidence interval 1.082–5.036; P=0.031). Conclusion Arterial stiffness is a moderate and independent predictive factor for MACEs in individuals with mildly impaired renal function (eGFR <90 mL/min/1.73 m2). PMID:27621605

  13. The predictive value of arterial stiffness on major adverse cardiovascular events in individuals with mildly impaired renal function

    PubMed Central

    Han, Jie; Wang, Xiaona; Ye, Ping; Cao, Ruihua; Yang, Xu; Xiao, Wenkai; Zhang, Yun; Bai, Yongyi; Wu, Hongmei

    2016-01-01

    Objectives Despite growing evidence that arterial stiffness has important predictive value for cardiovascular disease in patients with advanced stages of chronic kidney disease, the predictive significance of arterial stiffness in individuals with mildly impaired renal function has not been established. The aim of this study was to evaluate the predictive value of arterial stiffness on cardiovascular disease in this specific population. Materials and methods We analyzed measurements of arterial stiffness (carotid–femoral pulse-wave velocity [cf-PWV]) and the incidence of major adverse cardiovascular events (MACEs) in 1,499 subjects from a 4.8-year longitudinal study. Results A multivariate Cox proportional-hazard regression analysis showed that in individuals with normal renal function (estimated glomerular filtration rate [eGFR] ≥90 mL/min/1.73 m2), the baseline cf-PWV was not associated with occurrence of MACEs (hazard ratio 1.398, 95% confidence interval 0.748–2.613; P=0.293). In individuals with mildly impaired renal function (eGFR <90 mL/min/1.73 m2), a higher baseline cf-PWV level was associated with a higher risk of MACEs (hazard ratio 2.334, 95% confidence interval 1.082–5.036; P=0.031). Conclusion Arterial stiffness is a moderate and independent predictive factor for MACEs in individuals with mildly impaired renal function (eGFR <90 mL/min/1.73 m2).

  14. Can mutualistic morality predict how individuals deal with benefits they did not deserve?

    PubMed

    Bonnefon, Jean-François; Girotto, Vittorio; Heimann, Marco; Legrenzi, Paolo

    2013-02-01

    An individual obtains an unfair benefit and faces the dilemma of either hiding it (to avoid being excluded from future interactions) or disclosing it (to avoid being discovered as a deceiver). In line with the target article, we expect that this dilemma will be solved by a fixed individual strategy rather than a case-by-case rational calculation. PMID:23445580

  15. Curious Eyes: Individual Differences in Personality Predict Eye Movement Behavior in Scene-Viewing

    ERIC Educational Resources Information Center

    Risko, Evan F.; Anderson, Nicola C.; Lanthier, Sophie; Kingstone, Alan

    2012-01-01

    Visual exploration is driven by two main factors--the stimuli in our environment, and our own individual interests and intentions. Research investigating these two aspects of attentional guidance has focused almost exclusively on factors common across individuals. The present study took a different tack, and examined the role played by individual…

  16. Individual-learning ability predicts social-foraging strategy in house sparrows.

    PubMed

    Katsnelson, Edith; Motro, Uzi; Feldman, Marcus W; Lotem, Arnon

    2011-02-22

    Social foragers can use either a 'producer' strategy, which involves searching for food, or a 'scrounger' strategy, which involves joining others' food discoveries. While producers rely on personal information and past experience, we may ask whether the tendency to forage as a producer is related to being a better learner. To answer this question, we hand-raised house sparrow (Passer domesticus) nestlings that upon independence were given an individual-learning task that required them to associate colour signal and food presence. Following the testing phase, all fledglings were released into a shared aviary, and their social-foraging tendencies were measured. We found a significant positive correlation between individual's performance in the individual-learning task and subsequent tendency to use searching (producing) behaviour. Individual-learning score was negatively correlated with initial fear of the test apparatus and with body weight. However, the correlation between individual learning and searching remained significant after controlling for these variables. Since it was measured before the birds entered a social group, individual-learning ability could not be the outcome of being a producer. However, the two traits may be initially associated, or individual learning could facilitate producing behaviour. To our knowledge, this is the first evidence that associates individual-learning abilities with social-foraging strategies in animal groups.

  17. Resting EEG in Alpha and Beta Bands Predicts Individual Differences in Attentional Blink Magnitude

    ERIC Educational Resources Information Center

    MacLean, Mary H.; Arnell, Karen M.; Cote, Kimberly A.

    2012-01-01

    Accuracy for a second target (T2) is reduced when it is presented within 500 ms of a first target (T1) in a rapid serial visual presentation (RSVP)--an attentional blink (AB). There are reliable individual differences in the magnitude of the AB. Recent evidence has shown that the attentional approach that an individual typically adopts during a…

  18. Distribution Patterns Predict Individual Specialization in the Diet of Dolphin Gulls

    PubMed Central

    Masello, Juan F.; Wikelski, Martin; Voigt, Christian C.; Quillfeldt, Petra

    2013-01-01

    Many animals show some degree of individual specialization in foraging strategies and diet. This has profound ecological and evolutionary implications. For example, populations containing diverse individual foraging strategies will respond in different ways to changes in the environment, thus affecting the capacity of the populations to adapt to environmental changes and to diversify. However, patterns of individual specialization have been examined in few species. Likewise it is usually unknown whether specialization is maintained over time, because examining the temporal scale at which specialization occurs can prove difficult in the field. In the present study, we analyzed individual specialization in foraging in Dolphin Gulls Leucophaeus scoresbii, a scavenger endemic to the southernmost coasts of South America. We used GPS position logging and stable isotope analyses (SIA) to investigate individual specialization in feeding strategies and their persistence over time. The analysis of GPS data indicated two major foraging strategies in Dolphin Gulls from New I. (Falkland Is./Islas Malvinas). Tagged individuals repeatedly attended either a site with mussel beds or seabird and seal colonies during 5 to 7 days of tracking. Females foraging at mussel beds were heavier than those foraging at seabird colonies. Nitrogen isotope ratios (δ15N) of Dolphin Gull blood cells clustered in two groups, showing that individuals were consistent in their preferred foraging strategies over a period of at least several weeks. The results of the SIA as well as the foraging patterns recorded revealed a high degree of specialization for particular feeding sites and diets by individual Dolphin Gulls. Individual differences in foraging behavior were not related to sex. Specialization in Dolphin Gulls may be favored by the advantages of learning and memorizing optimal feeding locations and behaviors. Specialized individuals may reduce search and handling time and thus, optimize their

  19. An efficient algorithm for de novo predictions of biochemical pathways between chemical compounds

    PubMed Central

    2012-01-01

    Background Prediction of biochemical (metabolic) pathways has a wide range of applications, including the optimization of drug candidates, and the elucidation of toxicity mechanisms. Recently, several methods have been developed for pathway prediction to derive a goal compound from a start compound. However, these methods require high computational costs, and cannot perform comprehensive prediction of novel metabolic pathways. Our aim of this study is to develop a de novo prediction method for reconstructions of metabolic pathways and predictions of unknown biosynthetic pathways in the sense that it does not require any initial network such as KEGG metabolic network to be explored. Results We formulated pathway prediction between a start compound and a goal compound as the shortest path search problem in terms of the number of enzyme reactions applied. We propose an efficient search method based on A* algorithm and heuristic techniques utilizing Linear Programming (LP) solution for estimation of the distance to the goal. First, a chemical compound is represented by a feature vector which counts frequencies of substructure occurrences in the structural formula. Second, an enzyme reaction is represented as an operator vector by detecting the structural changes to compounds before and after the reaction. By defining compound vectors as nodes and operator vectors as edges, prediction of the reaction pathway is reduced to the shortest path search problem in the vector space. In experiments on the DDT degradation pathway, we verify that the shortest paths predicted by our method are biologically correct pathways registered in the KEGG database. The results also demonstrate that the LP heuristics can achieve significant reduction in computation time. Furthermore, we apply our method to a secondary metabolite pathway of plant origin, and successfully find a novel biochemical pathway which cannot be predicted by the existing method. For the reconstruction of a known

  20. Individual difference in prepulse inhibition does not predict spatial learning and memory performance in C57BL/6 mice.

    PubMed

    Peleg-Raibstein, Daria; Philipp, Singer; Feldon, Joram; Yee, Benjamin K

    2015-12-01

    The startle reflex to an intense acoustic pulse stimulus is attenuated if the pulse stimulus is shortly preceded by a weak non-startling prepulse stimulus. This attenuation of the startle reflex represents a form of pre-attentional sensory gating known as prepulse inhibition (PPI). Although PPI does not require learning, its expression is regulated by higher cognitive processes. PPI deficits have been detected in several psychiatric conditions including schizophrenia where they co-exist with cognitive deficits. A potential link between PPI expression and cognitive performance has therefore been suggested such that poor PPI may predict, or may be mechanistically linked to, overt cognitive impairments. A positive relationship between PPI and strategy formation, planning efficiency, and execution speed has been observed in healthy humans. However, parallel studies in healthy animals are rare. It thus remains unclear what cognitive domains may be associated with, or orthogonal to, sensory gating in the form of PPI in healthy animals. The present study evaluated a potential link between the magnitude of PPI and spatial memory performance by comparing two subgroups of animals differing substantially in baseline PPI expression (low-PPI vs high-PPI) within a homogenous cohort of 100 male adult C57BL/6 mice. Assessment of spatial reference memory in the Morris water maze and spatial recognition memory in the Y-maze failed to reveal any difference between low-PPI and high-PPI subjects. These negative findings contrast with our previous reports that individual difference in PPI correlated with sustained attention and working memory performance in C57BL/6 mice.

  1. The Influence of Dust On The Rainfall Efficiency and Its Potential For Seasonal Predictions

    NASA Astrophysics Data System (ADS)

    Bistritschan, T.; Norton, W.; Washington, R.

    I will approach the question wether dust has an effect on the rainfall efficiency and should therefore be included in GCMs when predicting African rainfall. A statistical analysis will be presented showing that the presence of dust reduces the rainfall effi- ciency. This analysis uses satellite derived precipitation estimates, gauge rainfall data and satellite derived dust fields, all of them are daily fields. Time lagged regressions are used to avoid unwanted feedback. I will also present a GCM study where observed dust fields are imposed and the rainfall efficiency of convective rain is a function of the dust concentration.

  2. Individual differences in mathematical competence predict parietal brain activation during mental calculation.

    PubMed

    Grabner, Roland H; Ansari, Daniel; Reishofer, Gernot; Stern, Elsbeth; Ebner, Franz; Neuper, Christa

    2007-11-01

    Functional neuroimaging studies have revealed that parietal brain circuits subserve arithmetic problem solving and that their recruitment dynamically changes as a function of training and development. The present study investigated whether the brain activation during mental calculation is also modulated by individual differences in mathematical competence. Twenty-five adult students were selected from a larger pool based on their performance on standardized tests of intelligence and arithmetic and divided into groups of individuals with relatively lower and higher mathematical competence. These groups did not differ in their non-numerical intelligence or age. In an fMRI block-design, participants had to verify the correctness of single-digit and multi-digit multiplication problems. Analyses revealed that the individuals with higher mathematical competence displayed stronger activation of the left angular gyrus while solving both types of arithmetic problems. Additional correlational analyses corroborated the association between individual differences in mathematical competence and angular gyrus activation, even when variability in task performance was controlled for. These findings demonstrate that the recruitment of the left angular gyrus during arithmetic problem solving underlies individual differences in mathematical ability and suggests a stronger reliance on automatic, language-mediated processes in more competent individuals.

  3. A Simple and Efficient Computational Approach to Chafed Cable Time-Domain Reflectometry Signature Prediction

    NASA Technical Reports Server (NTRS)

    Kowalski, Marc Edward

    2009-01-01

    A method for the prediction of time-domain signatures of chafed coaxial cables is presented. The method is quasi-static in nature, and is thus efficient enough to be included in inference and inversion routines. Unlike previous models proposed, no restriction on the geometry or size of the chafe is required in the present approach. The model is validated and its speed is illustrated via comparison to simulations from a commercial, three-dimensional electromagnetic simulator.

  4. An Efficient Deterministic Approach to Model-based Prediction Uncertainty Estimation

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew J.; Saxena, Abhinav; Goebel, Kai

    2012-01-01

    Prognostics deals with the prediction of the end of life (EOL) of a system. EOL is a random variable, due to the presence of process noise and uncertainty in the future inputs to the system. Prognostics algorithm must account for this inherent uncertainty. In addition, these algorithms never know exactly the state of the system at the desired time of prediction, or the exact model describing the future evolution of the system, accumulating additional uncertainty into the predicted EOL. Prediction algorithms that do not account for these sources of uncertainty are misrepresenting the EOL and can lead to poor decisions based on their results. In this paper, we explore the impact of uncertainty in the prediction problem. We develop a general model-based prediction algorithm that incorporates these sources of uncertainty, and propose a novel approach to efficiently handle uncertainty in the future input trajectories of a system by using the unscented transformation. Using this approach, we are not only able to reduce the computational load but also estimate the bounds of uncertainty in a deterministic manner, which can be useful to consider during decision-making. Using a lithium-ion battery as a case study, we perform several simulation-based experiments to explore these issues, and validate the overall approach using experimental data from a battery testbed.

  5. Prediction of fruit and vegetable intake from biomarkers using individual participant data of diet-controlled intervention studies.

    PubMed

    Souverein, Olga W; de Vries, Jeanne H M; Freese, Riitta; Watzl, Bernhard; Bub, Achim; Miller, Edgar R; Castenmiller, Jacqueline J M; Pasman, Wilrike J; van Het Hof, Karin; Chopra, Mridula; Karlsen, Anette; Dragsted, Lars O; Winkels, Renate; Itsiopoulos, Catherine; Brazionis, Laima; O'Dea, Kerin; van Loo-Bouwman, Carolien A; Naber, Ton H J; van der Voet, Hilko; Boshuizen, Hendriek C

    2015-05-14

    Fruit and vegetable consumption produces changes in several biomarkers in blood. The present study aimed to examine the dose-response curve between fruit and vegetable consumption and carotenoid (α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin), folate and vitamin C concentrations. Furthermore, a prediction model of fruit and vegetable intake based on these biomarkers and subject characteristics (i.e. age, sex, BMI and smoking status) was established. Data from twelve diet-controlled intervention studies were obtained to develop a prediction model for fruit and vegetable intake (including and excluding fruit and vegetable juices). The study population in the present individual participant data meta-analysis consisted of 526 men and women. Carotenoid, folate and vitamin C concentrations showed a positive relationship with fruit and vegetable intake. Measures of performance for the prediction model were calculated using cross-validation. For the prediction model of fruit, vegetable and juice intake, the root mean squared error (RMSE) was 258.0 g, the correlation between observed and predicted intake was 0.78 and the mean difference between observed and predicted intake was - 1.7 g (limits of agreement: - 466.3, 462.8 g). For the prediction of fruit and vegetable intake (excluding juices), the RMSE was 201.1 g, the correlation was 0.65 and the mean bias was 2.4 g (limits of agreement: -368.2, 373.0 g). The prediction models which include the biomarkers and subject characteristics may be used to estimate average intake at the group level and to investigate the ranking of individuals with regard to their intake of fruit and vegetables when validating questionnaires that measure intake.

  6. Prediction of fruit and vegetable intake from biomarkers using individual participant data of diet-controlled intervention studies.

    PubMed

    Souverein, Olga W; de Vries, Jeanne H M; Freese, Riitta; Watzl, Bernhard; Bub, Achim; Miller, Edgar R; Castenmiller, Jacqueline J M; Pasman, Wilrike J; van Het Hof, Karin; Chopra, Mridula; Karlsen, Anette; Dragsted, Lars O; Winkels, Renate; Itsiopoulos, Catherine; Brazionis, Laima; O'Dea, Kerin; van Loo-Bouwman, Carolien A; Naber, Ton H J; van der Voet, Hilko; Boshuizen, Hendriek C

    2015-05-14

    Fruit and vegetable consumption produces changes in several biomarkers in blood. The present study aimed to examine the dose-response curve between fruit and vegetable consumption and carotenoid (α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin), folate and vitamin C concentrations. Furthermore, a prediction model of fruit and vegetable intake based on these biomarkers and subject characteristics (i.e. age, sex, BMI and smoking status) was established. Data from twelve diet-controlled intervention studies were obtained to develop a prediction model for fruit and vegetable intake (including and excluding fruit and vegetable juices). The study population in the present individual participant data meta-analysis consisted of 526 men and women. Carotenoid, folate and vitamin C concentrations showed a positive relationship with fruit and vegetable intake. Measures of performance for the prediction model were calculated using cross-validation. For the prediction model of fruit, vegetable and juice intake, the root mean squared error (RMSE) was 258.0 g, the correlation between observed and predicted intake was 0.78 and the mean difference between observed and predicted intake was - 1.7 g (limits of agreement: - 466.3, 462.8 g). For the prediction of fruit and vegetable intake (excluding juices), the RMSE was 201.1 g, the correlation was 0.65 and the mean bias was 2.4 g (limits of agreement: -368.2, 373.0 g). The prediction models which include the biomarkers and subject characteristics may be used to estimate average intake at the group level and to investigate the ranking of individuals with regard to their intake of fruit and vegetables when validating questionnaires that measure intake. PMID:25850683

  7. Cerebral asymmetry in the fusiform areas predicted the efficiency of learning a new writing system.

    PubMed

    Xue, Gui; Chen, Chuansheng; Jin, Zhen; Dong, Qi

    2006-06-01

    There are great individual differences in learning abilities, but their neural bases, especially among normal populations, are not well understood. Using functional magnetic resonance imaging and a training paradigm, the present study investigated individual differences in cerebral asymmetry in fusiform regions when processing a new writing system and their correlation to subsequent visual character learning. Twelve Chinese adults underwent a 2-week training to learn 120 Korean characters and they were scanned before and after the training. Results showed that left-hemispheric dominance during the pretraining task was predictive of better posttraining performance. These results have significant implications for our understanding of the neural basis of language learning, especially in terms of individual differences.

  8. New Mechanistic Based Correlation Equation for Predicting Colloid Attachment Efficiency: Traditional vs. Discrete Heterogeneity Approaches

    NASA Astrophysics Data System (ADS)

    Pazmino, E. F.; Johnson, W. P.

    2014-12-01

    In this work we present a correlation equation that predicts colloid attachment efficiency over soda-lime glass collectors. We review the traditional attachment efficiency approaches, which are based on packed column experiments and mean field parameters that define the colloid-collector interactions, and contrast them with a discrete heterogeneity approach. This new correlation equation was developed to capture prediction from a trajectory model that quantitatively explains directly observed colloid retention in an impinging jet system under unfavorable conditions via incorporation of discrete zones of attraction (nanoscale heterodomains). In order compare of observed and simulated retention in the impinging jet with granular porous media, we developed a linkage between the jet and Happel sphere unit-cell geometries. We demonstrate that attachment efficiency can be mechanistically explained by near surface trajectory analysis and well represented by three terms: 1) Maxwell distribution of colloids in the near surface fluid domain, 2) Spacing and size distribution of heterodomains on the collector relative to colloid size, and 3) Torque and force balance of the colloid in contact with heterodomains. These results indicate that a traditional empirical approach can be improved to a theoretical framework that, from basic principles, is able to predict colloid retention under unfavorable conditions.

  9. Trait Mindfulness Predicts Efficient Top-Down Attention to and Discrimination of Facial Expressions.

    PubMed

    Quaglia, Jordan T; Goodman, Robert J; Brown, Kirk Warren

    2016-06-01

    In social situations, skillful regulation of emotion and behavior depends on efficiently discerning others' emotions. Identifying factors that promote timely and accurate discernment of facial expressions can therefore advance understanding of social emotion regulation and behavior. The present research examined whether trait mindfulness predicts neural and behavioral markers of early top-down attention to, and efficient discrimination of, socioemotional stimuli. Attention-based event-related potentials (ERPs) and behavioral responses were recorded while participants (N = 62; White; 67% female; Mage = 19.09 years, SD = 2.14 years) completed an emotional go/no-go task involving happy, neutral, and fearful facial expressions. Mindfulness predicted larger (more negative) N100 and N200 ERP amplitudes to both go and no-go stimuli. Mindfulness also predicted faster response time that was not attributable to a speed-accuracy trade-off. Significant relations held after accounting for attentional control or social anxiety. This study adds neurophysiological support for foundational accounts that mindfulness entails moment-to-moment attention with lower tendencies toward habitual patterns of responding. Mindfulness may enhance the quality of social behavior in socioemotional contexts by promoting efficient top-down attention to and discrimination of others' emotions, alongside greater monitoring and inhibition of automatic response tendencies. PMID:25676934

  10. Trait Mindfulness Predicts Efficient Top-Down Attention to and Discrimination of Facial Expressions.

    PubMed

    Quaglia, Jordan T; Goodman, Robert J; Brown, Kirk Warren

    2016-06-01

    In social situations, skillful regulation of emotion and behavior depends on efficiently discerning others' emotions. Identifying factors that promote timely and accurate discernment of facial expressions can therefore advance understanding of social emotion regulation and behavior. The present research examined whether trait mindfulness predicts neural and behavioral markers of early top-down attention to, and efficient discrimination of, socioemotional stimuli. Attention-based event-related potentials (ERPs) and behavioral responses were recorded while participants (N = 62; White; 67% female; Mage = 19.09 years, SD = 2.14 years) completed an emotional go/no-go task involving happy, neutral, and fearful facial expressions. Mindfulness predicted larger (more negative) N100 and N200 ERP amplitudes to both go and no-go stimuli. Mindfulness also predicted faster response time that was not attributable to a speed-accuracy trade-off. Significant relations held after accounting for attentional control or social anxiety. This study adds neurophysiological support for foundational accounts that mindfulness entails moment-to-moment attention with lower tendencies toward habitual patterns of responding. Mindfulness may enhance the quality of social behavior in socioemotional contexts by promoting efficient top-down attention to and discrimination of others' emotions, alongside greater monitoring and inhibition of automatic response tendencies.

  11. Individual variability in finger-to-finger transmission efficiency of Enterococcus faecium clones

    PubMed Central

    del Campo, Rosa; Sánchez-Díaz, Ana María; Zamora, Javier; Torres, Carmen; Cintas, Luis María; Franco, Elvira; Cantón, Rafael; Baquero, Fernando

    2014-01-01

    A fingertip-to-fingertip intraindividual transmission experiment was carried out in 30 healthy volunteers, using four MLST-typed Enterococcus faecium clones. Overall results showed an adequate fit goodness to a theoretical exponential model, whereas four volunteers (13%) exhibited a significantly higher finger-to-finger bacterial transmission efficiency. This observation might have deep consequences in nosocomial epidemiology. PMID:24382843

  12. Individual variability in finger-to-finger transmission efficiency of Enterococcus faecium clones.

    PubMed

    del Campo, Rosa; Sánchez-Díaz, Ana María; Zamora, Javier; Torres, Carmen; Cintas, Luis María; Franco, Elvira; Cantón, Rafael; Baquero, Fernando

    2014-02-01

    A fingertip-to-fingertip intraindividual transmission experiment was carried out in 30 healthy volunteers, using four MLST-typed Enterococcus faecium clones. Overall results showed an adequate fit goodness to a theoretical exponential model, whereas four volunteers (13%) exhibited a significantly higher finger-to-finger bacterial transmission efficiency. This observation might have deep consequences in nosocomial epidemiology. PMID:24382843

  13. Efficient method for predicting crystal structures at finite temperature: variable box shape simulations.

    PubMed

    Filion, Laura; Marechal, Matthieu; van Oorschot, Bas; Pelt, Daniël; Smallenburg, Frank; Dijkstra, Marjolein

    2009-10-30

    We present an efficient and robust method based on Monte Carlo simulations for predicting crystal structures at finite temperature. We apply this method, which is surprisingly easy to implement, to a variety of systems, demonstrating its effectiveness for hard, attractive, and anisotropic interactions, binary mixtures, semi-long-range soft interactions, and truly long-range interactions where the truly long-range interactions are treated using Ewald sums. In the case of binary hard-sphere mixtures, star polymers, and binary Lennard-Jones mixtures, the crystal structures predicted by this algorithm are consistent with literature, providing confidence in the method. Finally, we predict new crystal structures for hard asymmetric dumbbell particles, bowl-like particles and hard oblate cylinders and present the phase diagram for the oblate cylinders based on full free energy calculations. PMID:19905838

  14. Trait-like differences in underlying oscillatory state predict individual differences in the TMS-evoked response

    PubMed Central

    Kundu, Bornali; Johnson, Jeffrey S.; Postle, Bradley R.

    2014-01-01

    Background Combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) can provide insights into how differing cognitive contexts produce different brain states, through TMS-based measures of effective connectivity. For instance, in a recent study, the amplitude of the TMS-evoked response (TMS-ER) derived during the delay-period of a spatial short-term memory (STM) task had a larger amplitude, and greater spread to distal cortical areas, than the TMS-ER from a fixation condition [1]. This indicated that the brain's electrical response to TMS is influenced by the cognitive context (STM or fixation) at the time of stimulation. This study also showed significant individual differences in the shape of the TMS-ER. Further, delay-period spectrograms revealed patterns of activity, the sustained pattern of delay-period activity (SPDPA), which were different across individuals. Objective/Hypothesis The present study addressed whether individual differences in the SPDPA predict spectral properties of the TMS-ER. We predicted that significant relationships would exist in task-relevant areas, such as the prefrontal cortex in the case of STM. Methods The TMS-ER was derived using TMS-EEG and source-localization methods. Results The SPDPA varied significantly across subjects, and these differences predicted individual differences in several frequency-dependent parameters of the TMS-ER that were specific to task-relevant areas, including prefrontal cortex for STM. Furthermore, a follow-up test-retest study revealed that the SPDPA was stable over sessions. Conclusions These observations offer a window into how individual differences in the effects of TMS are related to trait-like individual differences in physiological profile. PMID:24472620

  15. Individual differences in the psychomotor effects of morphine are predicted by reactivity to novelty and influenced by corticosterone secretion.

    PubMed

    Deroche, V; Piazza, P V; Le Moal, M; Simon, H

    1993-10-01

    Clinical observations show that individual vulnerability to the reinforcing properties of drugs plays an important part in the subsequent development of addition. In animals, individual vulnerability to psychostimulants has been found to be predicted by their locomotor response to novelty as well as their corticosterone response. Rats with a high locomotor response to novelty (High Responders or HR) relative to Low Responders (LR), show a higher sensitivity to both the psychomotor and reinforcing effects of psychostimulants and a longer lasting corticosterone secretion in response to stress. In this study, we addressed two main questions. First, does the locomotor response to novelty also predict the psychomotor effects of morphine? Second, do differences in corticosterone secretion underlie individual differences in the stimulant effects of morphine? We compared the locomotor response to morphine (2 mg/kg s.c.) in: (i) HR and LR rats with an intact hypothalamo-pituitary-adrenal (HPA) axis; (ii) HR and LR rats in which stress-induced corticosterone secretion was suppressed by adrenalectomy but basal levels of corticosterone were maintained by implantation of subcutaneous corticosterone pellets. In animals with an intact HPA axis, HR rats showed a higher locomotor response than did LRs to morphine. In animals in which corticosterone secretion was suppressed, the enhanced locomotor response of the HRs to morphine fell to that observed in the LRs. In conclusion our data show that, (1) individual reactivity to novelty can predict individual vulnerability to the psychomotor effects of opioids, and (2) stress-induced corticosterone secretion may play a role in determining individual differences in sensitivity to these drugs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8221119

  16. Novelty seeking is related to individual risk preference and brain activation associated with risk prediction during decision making

    PubMed Central

    Wang, Ying; Liu, Ying; Yang, Lizhuang; Gu, Feng; Li, Xiaoming; Zha, Rujing; Wei, Zhengde; Pei, Yakun; Zhang, Peng; Zhou, Yifeng; Zhang, Xiaochu

    2015-01-01

    Novelty seeking (NS) is a personality trait reflecting excitement in response to novel stimuli. High NS is usually a predictor of risky behaviour such as drug abuse. However, the relationships between NS and risk-related cognitive processes, including individual risk preference and the brain activation associated with risk prediction, remain elusive. In this fMRI study, participants completed the Tridimensional Personality Questionnaire to measure NS and performed a probabilistic decision making task. Using a mathematical model, we estimated individual risk preference. Brain regions associated with risk prediction were determined via fMRI. The NS score showed a positive correlation with risk preference and a negative correlation with the activation elicited by risk prediction in the right posterior insula (r-PI), left anterior insula (l-AI), right striatum (r-striatum) and supplementary motor area (SMA). Within these brain regions, only the activation associated with risk prediction in the r-PI showed a correlation with NS after controlling for the effect of risk preference. Resting-state functional connectivity between the r-PI and r-striatum/l-AI was negatively correlated with NS. Our results suggest that high NS may be associated with less aversion to risk and that the r-PI plays an important role in relating risk prediction to NS. PMID:26065910

  17. Can We Predict Individual Combined Benefit and Harm of Therapy? Warfarin Therapy for Atrial Fibrillation as a Test Case

    PubMed Central

    Li, Guowei; Thabane, Lehana; Delate, Thomas; Witt, Daniel M.; Levine, Mitchell A. H.; Cheng, Ji; Holbrook, Anne

    2016-01-01

    Objectives To construct and validate a prediction model for individual combined benefit and harm outcomes (stroke with no major bleeding, major bleeding with no stroke, neither event, or both) in patients with atrial fibrillation (AF) with and without warfarin therapy. Methods Using the Kaiser Permanente Colorado databases, we included patients newly diagnosed with AF between January 1, 2005 and December 31, 2012 for model construction and validation. The primary outcome was a prediction model of composite of stroke or major bleeding using polytomous logistic regression (PLR) modelling. The secondary outcome was a prediction model of all-cause mortality using the Cox regression modelling. Results We included 9074 patients with 4537 and 4537 warfarin users and non-users, respectively. In the derivation cohort (n = 4632), there were 136 strokes (2.94%), 280 major bleedings (6.04%) and 1194 deaths (25.78%) occurred. In the prediction models, warfarin use was not significantly associated with risk of stroke, but increased the risk of major bleeding and decreased the risk of death. Both the PLR and Cox models were robust, internally and externally validated, and with acceptable model performances. Conclusions In this study, we introduce a new methodology for predicting individual combined benefit and harm outcomes associated with warfarin therapy for patients with AF. Should this approach be validated in other patient populations, it has potential advantages over existing risk stratification approaches as a patient-physician aid for shared decision-making PMID:27513986

  18. Individual Differences in Lexical Processing at 18 Months Predict Vocabulary Growth in Typically-Developing and Late-Talking Toddlers

    PubMed Central

    Fernald, Anne; Marchman, Virginia A.

    2011-01-01

    Using online measures of familiar word recognition in the looking-while-listening procedure, this prospective longitudinal study revealed robust links between processing efficiency and vocabulary growth from 18 to 30 months in children classified as typically-developing (n = 46) and as “late talkers” (n = 36) at 18 months. Those late-talkers who were more efficient in word recognition at 18 months were also more likely to “bloom”, showing more accelerated vocabulary growth over the following year, compared to late-talkers less efficient in early speech processing. Such findings support the emerging view that early differences in processing efficiency evident in infancy have cascading consequences for later learning and may be continuous with individual differences in language proficiency observed in older children and adults. PMID:22172209

  19. Investigating the importance of various individual, interpersonal, organisational and demographic variables when predicting job burnout in disability support workers.

    PubMed

    Vassos, Maria V; Nankervis, Karen L

    2012-01-01

    Previous research has highlighted that factors such as large workload, role ambiguity, lack of support from colleagues, and challenging behaviour are associated with higher levels of burnout within the disability support worker (DSW) population. The aim of this research was to investigate which factors contribute the most to the prediction of the three facets of burnout--feeling exhausted and overextended by one's work (emotional exhaustion), detached and callous responses towards work (depersonalisation) and a lack of achievement and productivity within one's role (personal accomplishment). The factors chosen for analysis within this research were analysed within four categories linked to theories of burnout development (individual, interpersonal, organisational and demographic). A sample of 108 DSWs completed a questionnaire booklet that contained standardised measures of burnout and job stressors related to disability work. Results highlighted the importance of predictors such as challenging behaviour (interpersonal), workload (individual), supervisor support (individual), work-home conflict (individual), job feedback (individual), role ambiguity (organisational), low job status (organisational), role conflict (organisational), gender (demographic) and work hours (demographic) when predicting one or more of the facets of burnout. In conclusion, disability services and organisations may benefit from focusing on remodelling their staff-related organisational practices in order to prevent the development of burnout in their DSWs (e.g., increase supervision and support practices).

  20. Investigating the importance of various individual, interpersonal, organisational and demographic variables when predicting job burnout in disability support workers.

    PubMed

    Vassos, Maria V; Nankervis, Karen L

    2012-01-01

    Previous research has highlighted that factors such as large workload, role ambiguity, lack of support from colleagues, and challenging behaviour are associated with higher levels of burnout within the disability support worker (DSW) population. The aim of this research was to investigate which factors contribute the most to the prediction of the three facets of burnout--feeling exhausted and overextended by one's work (emotional exhaustion), detached and callous responses towards work (depersonalisation) and a lack of achievement and productivity within one's role (personal accomplishment). The factors chosen for analysis within this research were analysed within four categories linked to theories of burnout development (individual, interpersonal, organisational and demographic). A sample of 108 DSWs completed a questionnaire booklet that contained standardised measures of burnout and job stressors related to disability work. Results highlighted the importance of predictors such as challenging behaviour (interpersonal), workload (individual), supervisor support (individual), work-home conflict (individual), job feedback (individual), role ambiguity (organisational), low job status (organisational), role conflict (organisational), gender (demographic) and work hours (demographic) when predicting one or more of the facets of burnout. In conclusion, disability services and organisations may benefit from focusing on remodelling their staff-related organisational practices in order to prevent the development of burnout in their DSWs (e.g., increase supervision and support practices). PMID:22699251

  1. Modeling recombination processes and predicting energy conversion efficiency of dye sensitized solar cells from first principles

    NASA Astrophysics Data System (ADS)

    Ma, Wei; Meng, Sheng

    2014-03-01

    We present a set of algorithms based on solo first principles calculations, to accurately calculate key properties of a DSC device including sunlight harvest, electron injection, electron-hole recombination, and open circuit voltages. Two series of D- π-A dyes are adopted as sample dyes. The short circuit current can be predicted by calculating the dyes' photo absorption, and the electron injection and recombination lifetime using real-time time-dependent density functional theory (TDDFT) simulations. Open circuit voltage can be reproduced by calculating energy difference between the quasi-Fermi level of electrons in the semiconductor and the electrolyte redox potential, considering the influence of electron recombination. Based on timescales obtained from real time TDDFT dynamics for excited states, the estimated power conversion efficiency of DSC fits nicely with the experiment, with deviation below 1-2%. Light harvesting efficiency, incident photon-to-electron conversion efficiency and the current-voltage characteristics can also be well reproduced. The predicted efficiency can serve as either an ideal limit for optimizing photovoltaic performance of a given dye, or a virtual device that closely mimicking the performance of a real device under different experimental settings.

  2. Efficient Prediction Structures for H.264 Multi View Coding Using Temporal Scalability

    NASA Astrophysics Data System (ADS)

    Guruvareddiar, Palanivel; Joseph, Biju K.

    2014-03-01

    Prediction structures with "disposable view components based" hierarchical coding have been proven to be efficient for H.264 multi view coding. Though these prediction structures along with the QP cascading schemes provide superior compression efficiency when compared to the traditional IBBP coding scheme, the temporal scalability requirements of the bit stream could not be met to the fullest. On the other hand, a fully scalable bit stream, obtained by "temporal identifier based" hierarchical coding, provides a number of advantages including bit rate adaptations and improved error resilience, but lacks in compression efficiency when compared to the former scheme. In this paper it is proposed to combine the two approaches such that a fully scalable bit stream could be realized with minimal reduction in compression efficiency when compared to state-of-the-art "disposable view components based" hierarchical coding. Simulation results shows that the proposed method enables full temporal scalability with maximum BDPSNR reduction of only 0.34 dB. A novel method also has been proposed for the identification of temporal identifier for the legacy H.264/AVC base layer packets. Simulation results also show that this enables the scenario where the enhancement views could be extracted at a lower frame rate (1/2nd or 1/4th of base view) with average extraction time for a view component of only 0.38 ms.

  3. An approximate solution to improve computational efficiency of impedance-type payload load prediction

    NASA Technical Reports Server (NTRS)

    White, C. W.

    1981-01-01

    The computational efficiency of the impedance type loads prediction method was studied. Three goals were addressed: devise a method to make the impedance method operate more efficiently in the computer; assess the accuracy and convenience of the method for determining the effect of design changes; and investigate the use of the method to identify design changes for reduction of payload loads. The method is suitable for calculation of dynamic response in either the frequency or time domain. It is concluded that: the choice of an orthogonal coordinate system will allow the impedance method to operate more efficiently in the computer; the approximate mode impedance technique is adequate for determining the effect of design changes, and is applicable for both statically determinate and statically indeterminate payload attachments; and beneficial design changes to reduce payload loads can be identified by the combined application of impedance techniques and energy distribution review techniques.

  4. Using individual interest and conscientiousness to predict academic effort: Additive, synergistic, or compensatory effects?

    PubMed

    Trautwein, Ulrich; Lüdtke, Oliver; Nagy, Nicole; Lenski, Anna; Niggli, Alois; Schnyder, Inge

    2015-07-01

    Although both conscientiousness and domain-specific interest are believed to be major determinants of academic effort, they have rarely been brought together in empirical studies. In the present research, it was hypothesized that both interest and conscientiousness uniquely predict academic effort and statistically interact with each other to predict academic effort. In 4 studies with 2,557, 415, 1,025, and 1,531 students, respectively, conscientiousness and interest meaningfully and uniquely predicted academic effort. In addition, conscientiousness interacted with interest in a compensatory pattern, indicating that conscientiousness is especially important when a student finds a school subject uninteresting and that domain-specific interest plays a particularly important role for students low in conscientiousness. PMID:25915134

  5. Development and Validation of a Multidisciplinary Tool for Accurate and Efficient Rotorcraft Noise Prediction (MUTE)

    NASA Technical Reports Server (NTRS)

    Liu, Yi; Anusonti-Inthra, Phuriwat; Diskin, Boris

    2011-01-01

    A physics-based, systematically coupled, multidisciplinary prediction tool (MUTE) for rotorcraft noise was developed and validated with a wide range of flight configurations and conditions. MUTE is an aggregation of multidisciplinary computational tools that accurately and efficiently model the physics of the source of rotorcraft noise, and predict the noise at far-field observer locations. It uses systematic coupling approaches among multiple disciplines including Computational Fluid Dynamics (CFD), Computational Structural Dynamics (CSD), and high fidelity acoustics. Within MUTE, advanced high-order CFD tools are used around the rotor blade to predict the transonic flow (shock wave) effects, which generate the high-speed impulsive noise. Predictions of the blade-vortex interaction noise in low speed flight are also improved by using the Particle Vortex Transport Method (PVTM), which preserves the wake flow details required for blade/wake and fuselage/wake interactions. The accuracy of the source noise prediction is further improved by utilizing a coupling approach between CFD and CSD, so that the effects of key structural dynamics, elastic blade deformations, and trim solutions are correctly represented in the analysis. The blade loading information and/or the flow field parameters around the rotor blade predicted by the CFD/CSD coupling approach are used to predict the acoustic signatures at far-field observer locations with a high-fidelity noise propagation code (WOPWOP3). The predicted results from the MUTE tool for rotor blade aerodynamic loading and far-field acoustic signatures are compared and validated with a variation of experimental data sets, such as UH60-A data, DNW test data and HART II test data.

  6. "All in a day's work": how follower individual differences and justice perceptions predict OCB role definitions and behavior.

    PubMed

    Kamdar, Dishan; McAllister, Daniel J; Turban, Daniel B

    2006-07-01

    The authors draw on theories of social exchange and prosocial behavior to explain how employee perceptions of procedural justice and individual differences in reciprocation wariness, empathic concern, and perspective taking function jointly as determinants of organizational citizenship behavior (OCB) role definitions and behavior. As hypothesized, empirical findings from a field study show both direct and interactive effects of procedural justice perceptions and individual differences on OCB role definition. In turn, OCB role definitions not only predict OCB directly but also moderate the effects of procedural justice perceptions on OCB. The authors explore the implications of these findings for practice as well as research.

  7. "All in a day's work": how follower individual differences and justice perceptions predict OCB role definitions and behavior.

    PubMed

    Kamdar, Dishan; McAllister, Daniel J; Turban, Daniel B

    2006-07-01

    The authors draw on theories of social exchange and prosocial behavior to explain how employee perceptions of procedural justice and individual differences in reciprocation wariness, empathic concern, and perspective taking function jointly as determinants of organizational citizenship behavior (OCB) role definitions and behavior. As hypothesized, empirical findings from a field study show both direct and interactive effects of procedural justice perceptions and individual differences on OCB role definition. In turn, OCB role definitions not only predict OCB directly but also moderate the effects of procedural justice perceptions on OCB. The authors explore the implications of these findings for practice as well as research. PMID:16834509

  8. Resting-state Networks Predict Individual Differences in Common and Specific Aspects of Executive Function

    PubMed Central

    Reineberg, Andrew E.; Andrews-Hanna, Jessica R.; Depue, Brendan; Friedman, Naomi P.; Banich, Marie T.

    2014-01-01

    The goal of the present study was to examine relationships between individual differences in resting state functional connectivity as ascertained by fMRI (rs-fcMRI) and performance on tasks of executive function (EF), broadly defined as the ability to regulate thoughts and actions. Unlike most previous research that focused on the relationship between rs-fcMRI and a single behavioral measure of EF, in the current study we examined the relationship of rs-fcMRI with individual differences in subcomponents of EF. Ninety-one adults completed a resting state fMRI scan and three separate EF tasks outside the magnet: inhibition of prepotent responses, task set shifting, and working memory updating. From these three measures, we derived estimates of common aspects of EF, as well as abilities specific to working memory updating and task shifting. Using Independent Components Analysis (ICA), we identified across the group of participants several networks of regions (Resting State Networks, RSNs) with temporally correlated time courses. We then used dual regression to explore how these RSNs covaried with individual differences in EF. Dual regression revealed that increased higher common EF was associated with connectivity of a) frontal pole with an attentional RSN, and b) Crus I and II of the cerebellum with the right frontoparietal RSN. Moreover, higher shifting-specific abilities were associated with increased connectivity of angular gyrus with a ventral attention RSN. The results of the current study suggest that the organization of the brain at rest may have important implications for individual differences in EF, and that individuals higher in EF may have expanded resting state networks as compared to individuals with lower EF. PMID:25281800

  9. Individual Differences in Executive Functioning Predict Preschoolers' Improvement from Theory-of-Mind Training

    ERIC Educational Resources Information Center

    Benson, Jeannette E.; Sabbagh, Mark A.; Carlson, Stephanie M.; Zelazo, Philip David

    2013-01-01

    Twenty-four 3.5-year-old children who initially showed poor performance on false-belief tasks participated in a training protocol designed to promote performance on these tasks. Our aim was to determine whether the extent to which children benefited from training was predicted by their performance on a battery of executive functioning tasks.…

  10. Predicting Perceptions of Date Rape Based on Individual Beliefs and Female Alcohol Consumption.

    ERIC Educational Resources Information Center

    Osman, Suzanne L.; Davis, Clive M.

    1999-01-01

    Investigates whether female alcohol consumption predicts perceptions of date rape based on two personality measures administered to 290 undergraduates. Results indicate that a stronger belief in token resistance to sex was related to weaker perceptions of rape. As hypothesized, participants scoring higher on sex-role stereotyping perceived fewer…

  11. Predicting Young Adult Outcome among More and Less Cognitively Able Individuals with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Anderson, Deborah K.; Liang, Jessie W.; Lord, Catherine

    2014-01-01

    Background: The range of outcomes for young adults with Autism Spectrum Disorders (ASD) and the early childhood factors associated with this diversity have implications for clinicians and scientists. Methods: This prospective study provided a unique opportunity to predict outcome 17 years later for a relatively large sample of children diagnosed…

  12. Predicting Change for Individual Psychotherapy Clients on the Basis of their Nearest Neighbors

    ERIC Educational Resources Information Center

    Lutz, Wolfgang; Leach, Chris; Barkham, Michael; Lucock, Mike; Stiles, William B.; Evans, Chris; Noble, Rachael; Iveson, Steve

    2005-01-01

    This study extended client-focused research by using the nearest neighbor (NN) approach, a client-specific sampling and prediction strategy derived from research on alpine avalanches. Psychotherapy clients (N = 203) seen in routine practice settings in the United Kingdom completed a battery of intake measures and then completed symptom intensity…

  13. Computational Fluency and Strategy Choice Predict Individual and Cross-National Differences in Complex Arithmetic

    ERIC Educational Resources Information Center

    Vasilyeva, Marina; Laski, Elida V.; Shen, Chen

    2015-01-01

    The present study tested the hypothesis that children's fluency with basic number facts and knowledge of computational strategies, derived from early arithmetic experience, predicts their performance on complex arithmetic problems. First-grade students from United States and Taiwan (N = 152, mean age: 7.3 years) were presented with problems that…

  14. Quantitative Approach to Collaborative Learning: Performance Prediction, Individual Assessment, and Group Composition

    ERIC Educational Resources Information Center

    Cen, Ling; Ruta, Dymitr; Powell, Leigh; Hirsch, Benjamin; Ng, Jason

    2016-01-01

    The benefits of collaborative learning, although widely reported, lack the quantitative rigor and detailed insight into the dynamics of interactions within the group, while individual contributions and their impacts on group members and their collaborative work remain hidden behind joint group assessment. To bridge this gap we intend to address…

  15. Individual Differences in Working Memory Capacity Predict Sleep-Dependent Memory Consolidation

    ERIC Educational Resources Information Center

    Fenn, Kimberly M.; Hambrick, David Z.

    2012-01-01

    Decades of research have established that "online" cognitive processes, which operate during conscious encoding and retrieval of information, contribute substantially to individual differences in memory. Furthermore, it is widely accepted that "offline" processes during sleep also contribute to memory performance. However, the question of whether…

  16. Severity of Hyperacusis Predicts Individual Differences in Speech Perception in Williams Syndrome

    ERIC Educational Resources Information Center

    Elsabbagh, M.; Cohen, H.; Cohen, M.; Rosen, S.; Karmiloff-Smith, A.

    2011-01-01

    Background: Williams Syndrome (WS) is a neurodevelopmental disorder of genetic origin, characterised by relative proficiency in language in the face of serious impairment in several other domains. Individuals with WS display an unusual sensitivity to noise, known as hyperacusis. Methods: In this study, we examined the extent to which hyperacusis…

  17. Individual Differences in (Non-Visual) Processing Style Predict the Face Inversion Effect

    ERIC Educational Resources Information Center

    Wyer, Natalie A.; Martin, Douglas; Pickup, Tracey; Macrae, C. Neil

    2012-01-01

    Recent research suggests that individuals with relatively weak global precedence (i.e., a smaller propensity to view visual stimuli in a configural manner) show a reduced face inversion effect (FIE). Coupled with such findings, a number of recent studies have demonstrated links between an advantage for feature-based processing and the presentation…

  18. PREDICTING THE EMISSIONS OF INDIVIDUAL VOCS FROM PETROLEUM-BASED INDOOR COATINGS

    EPA Science Inventory

    The indoor use of petroleum-based coating materials may cause elevated volatile organic compound (VOC) concentrations. This paper presents a newly developed mass transfer model for estimating the emissions of individual VOCs from freshly coated surfaces. Results of a four-step va...

  19. Individuation Experience Predicts Other-Race Effects in Holistic Processing for Both Caucasian and Black Participants

    ERIC Educational Resources Information Center

    Bukach, Cindy M.; Cottle, Jasmine; Ubiwa, JoAnna; Miller, Jessica

    2012-01-01

    Same-race (SR) faces are recognized better than other-race (OR) faces, and this other-race effect (ORE) is correlated with experience. SR faces are also processed more holistically than OR faces, suggesting one possible mechanism for poorer performance on OR faces. Studies of object expertise have shown that individuating experiences are necessary…

  20. Bullying and Victimization: Predictive Role of Individual, Parental, and Academic Factors

    ERIC Educational Resources Information Center

    Atik, Gökhan; Güneri, Oya Yerin

    2013-01-01

    This study explored the roles of individual factors (age, gender, locus of control, self-esteem, and loneliness), parenting style, and academic achievement in discriminating students involved in bullying (as bullies, victims, and bully/victims) from those not involved. Participants comprised 742 middle school students (393 females, 349 males). The…

  1. Effectiveness of genetic evaluations in predicting daughter performance in individual herds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Response to genetic selection has been demonstrated nationally for US dairy cattle, but producers are more likely to appreciate the value of genetic selection if trends within their own herds can be shown. Responses from 2004 through 2008 in individual herds by Holstein and Jersey cows were document...

  2. Structural covariance networks of the dorsal anterior insula predict females' individual differences in empathic responding.

    PubMed

    Bernhardt, Boris C; Klimecki, Olga M; Leiberg, Susanne; Singer, Tania

    2014-08-01

    Previous functional imaging studies have shown key roles of the dorsal anterior insula (dAI) and anterior midcingulate cortex (aMCC) in empathy for the suffering of others. The current study mapped structural covariance networks of these regions and assessed the relationship between networks and individual differences in empathic responding in 94 females. Individual differences in empathy were assessed through average state measures in response to a video task showing others' suffering, and through questionnaire-based trait measures of empathic concern. Overall, covariance patterns indicated that dAI and aMCC are principal hubs within prefrontal, temporolimbic, and midline structural covariance networks. Importantly, participants with high empathy state ratings showed increased covariance of dAI, but not aMCC, to prefrontal and limbic brain regions. This relationship was specific for empathy and could not be explained by individual differences in negative affect ratings. Regarding questionnaire-based empathic trait measures, we observed a similar, albeit weaker modulation of dAI covariance, confirming the robustness of our findings. Our analysis, thus, provides novel evidence for a specific contribution of frontolimbic structural covariance networks to individual differences in social emotions beyond negative affect.

  3. Individual Differences in Working Memory Capacity Predict Action Monitoring and the Error-Related Negativity

    ERIC Educational Resources Information Center

    Miller, A. Eve; Watson, Jason M.; Strayer, David L.

    2012-01-01

    Neuroscience suggests that the anterior cingulate cortex (ACC) is responsible for conflict monitoring and the detection of errors in cognitive tasks, thereby contributing to the implementation of attentional control. Though individual differences in frontally mediated goal maintenance have clearly been shown to influence outward behavior in…

  4. Migratory restlessness in captive individuals predicts actual departure in the wild

    PubMed Central

    Eikenaar, Cas; Klinner, Thomas; Szostek, K. Lesley; Bairlein, Franz

    2014-01-01

    In captivity, migratory birds show increased activity during the time that they would normally migrate. The phenology and intensity of such ‘migratory restlessness’ has been shown to mirror species- and population-specific migration patterns observed in the wild and has consequently been used as a proxy for the motivation to migrate. Many studies doing so, however, were aiming to explain among-individual variation in migratory behaviour or traits, and not species- or population-specific traits. These studies thus assumed that, also at the level of the individual, migratory restlessness is an accurate proxy for the motivation to migrate. We tested this assumption for the first time and found that it holds; individuals showing very little migratory restlessness remained at stopover for longer than one night, whereas most individuals showing more restlessness departed sooner. This finding validates the use of migratory restlessness as a proxy for the motivation to migrate, thereby justifying the conclusions made in a large body of research on avian migration. PMID:24718095

  5. IPR 1.0: an efficient method for calculating solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Chen, W.; Li, J.

    2013-12-01

    Climate change may alter the spatial distribution, composition, structure, and functions of plant communities. Transitional zones between biomes, or ecotones, are particularly sensitive to climate change. Ecotones are usually heterogeneous with sparse trees. The dynamics of ecotones are mainly determined by the growth and competition of individual plants in the communities. Therefore it is necessary to calculate solar radiation absorbed by individual plants for understanding and predicting their responses to climate change. In this study, we developed an individual plant radiation model, IPR (version 1.0), to calculate solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities. The model is developed based on geometrical optical relationships assuming crowns of woody plants are rectangular boxes with uniform leaf area density. The model calculates the fractions of sunlit and shaded leaf classes and the solar radiation absorbed by each class, including direct radiation from the sun, diffuse radiation from the sky, and scattered radiation from the plant community. The solar radiation received on the ground is also calculated. We tested the model by comparing with the analytical solutions of random distributions of plants. The tests show that the model results are very close to the averages of the random distributions. This model is efficient in computation, and is suitable for ecological models to simulate long-term transient responses of plant communities to climate change.

  6. Emotional Experiences Predict the Conversion of Individuals with Attenuated Psychosis Syndrome to Psychosis: A 6-Month Follow up Study

    PubMed Central

    Chen, Fa Zhan; Wang, Yi; Sun, Xi Rong; Yao, Yu Hong; Zhang, Ning; Qiao, Hui Fen; Zhang, Lan; Li, Zhan Jiang; Lin, Hong; Lu, Zheng; Li, Jing; Chan, Raymond C. K.; Zhao, Xu Dong

    2016-01-01

    The present study explored the conversion rate in individuals with Attenuated Psychosis Syndrome (APS) and potential predictor for transition in mainland China. Sixty-three participants identified as APS were followed up 6 months later. The results showed that 17% of individuals with APS converted to full-blown psychosis. The converters exhibited significantly poorer emotional experience and expression than the non-converters at baseline. A further binary logistic regression analysis showed that emotional experience could predict the transition (Wald = 4.18, p = 0.041, 95% CI = 1.04~6.82). The present study suggests an important role of emotional processing in the prediction of the development of full-blown psychosis. PMID:27313553

  7. Individual variation in fathers' testosterone reactivity to infant distress predicts parenting behaviors with their 1-year-old infants.

    PubMed

    Kuo, Patty X; Saini, Ekjyot K; Thomason, Elizabeth; Schultheiss, Oliver C; Gonzalez, Richard; Volling, Brenda L

    2016-04-01

    Positive father involvement is associated with positive child outcomes. There is great variation in fathers' involvement and fathering behaviors, and men's testosterone (T) has been proposed as a potential biological contributor to paternal involvement. Previous studies investigating testosterone changes in response to father-infant interactions or exposure to infant cues were unclear as to whether individual variation in T is predictive of fathering behavior. We show that individual variation in fathers' T reactivity to their infants during a challenging laboratory paradigm (Strange Situation) uniquely predicted fathers' positive parenting behaviors during a subsequent father-infant interaction, in addition to other psychosocial determinants of paternal involvement, such as dispositional empathy and marital quality. The findings have implications for understanding fathering behaviors and how fathers can contribute to their children's socioemotional development. PMID:26497119

  8. Does individual variation in metabolic phenotype predict fish behaviour and performance?

    PubMed

    Metcalfe, N B; Van Leeuwen, T E; Killen, S S

    2016-01-01

    There is increasing interest in documenting and explaining the existence of marked intraspecific variation in metabolic rate in animals, with fishes providing some of the best-studied examples. After accounting for variation due to other factors, there can typically be a two to three-fold variation among individual fishes for both standard and maximum metabolic rate (SMR and MMR). This variation is reasonably consistent over time (provided that conditions remain stable), and its underlying causes may be influenced by both genes and developmental conditions. In this paper, current knowledge of the extent and causes of individual variation in SMR, MMR and aerobic scope (AS), collectively its metabolic phenotype, is reviewed and potential links among metabolism, behaviour and performance are described. Intraspecific variation in metabolism has been found to be related to other traits: fishes with a relatively high SMR tend to be more dominant and grow faster in high food environments, but may lose their advantage and are more prone to risk-taking when conditions deteriorate. In contrast to the wide body of research examining links between SMR and behavioural traits, very little work has been directed towards understanding the ecological consequences of individual variation in MMR and AS. Although AS can differ among populations of the same species in response to performance demands, virtually nothing is known about the effects of AS on individual behaviours such as those associated with foraging or predator avoidance. Further, while factors such as food availability, temperature, hypoxia and the fish's social environment are known to alter resting and MMRs in fishes, there is a paucity of studies examining how these effects vary among individuals, and how this variation relates to behaviour. Given the observed links between metabolism and measures of performance, understanding the metabolic responses of individuals to changing environments will be a key area for

  9. Does individual variation in metabolic phenotype predict fish behaviour and performance?

    PubMed

    Metcalfe, N B; Van Leeuwen, T E; Killen, S S

    2016-01-01

    There is increasing interest in documenting and explaining the existence of marked intraspecific variation in metabolic rate in animals, with fishes providing some of the best-studied examples. After accounting for variation due to other factors, there can typically be a two to three-fold variation among individual fishes for both standard and maximum metabolic rate (SMR and MMR). This variation is reasonably consistent over time (provided that conditions remain stable), and its underlying causes may be influenced by both genes and developmental conditions. In this paper, current knowledge of the extent and causes of individual variation in SMR, MMR and aerobic scope (AS), collectively its metabolic phenotype, is reviewed and potential links among metabolism, behaviour and performance are described. Intraspecific variation in metabolism has been found to be related to other traits: fishes with a relatively high SMR tend to be more dominant and grow faster in high food environments, but may lose their advantage and are more prone to risk-taking when conditions deteriorate. In contrast to the wide body of research examining links between SMR and behavioural traits, very little work has been directed towards understanding the ecological consequences of individual variation in MMR and AS. Although AS can differ among populations of the same species in response to performance demands, virtually nothing is known about the effects of AS on individual behaviours such as those associated with foraging or predator avoidance. Further, while factors such as food availability, temperature, hypoxia and the fish's social environment are known to alter resting and MMRs in fishes, there is a paucity of studies examining how these effects vary among individuals, and how this variation relates to behaviour. Given the observed links between metabolism and measures of performance, understanding the metabolic responses of individuals to changing environments will be a key area for

  10. Disorder prediction-based construct optimization improves activity and catalytic efficiency of Bacillus naganoensis pullulanase

    PubMed Central

    Wang, Xinye; Nie, Yao; Mu, Xiaoqing; Xu, Yan; Xiao, Rong

    2016-01-01

    Pullulanase is a well-known starch-debranching enzyme. However, the production level of pullulanase is yet low in both wide-type strains and heterologous expression systems. We predicted the disorder propensities of Bacillus naganoensis pullulanase (PUL) using the bioinformatics tool, Disorder Prediction Meta-Server. On the basis of disorder prediction, eight constructs, including PULΔN5, PULΔN22, PULΔN45, PULΔN64, PULΔN78 and PULΔN106 by deleting the first 5, 22, 45, 64, 78 and 106 residues from the N-terminus, and PULΔC9 and PULΔC36 by deleting the last 9 and 36 residues from the C-terminus, were cloned into the recombinant expression vector pET-28a-PelB and auto-induced in Escherichia coli BL21 (DE3) cells. All constructs were evaluated in production level, specific activities and kinetic parameters. Both PULΔN5 and PULΔN106 gave higher production levels of protein than the wide type and displayed increased specific activities. Kinetic studies showed that substrate affinities of the mutants were improved in various degrees and the catalytic efficiency of PULΔN5, PULΔN45, PULΔN78, PULΔN106 and PULΔC9 were enhanced. However, the truncated mutations did not change the advantageous properties of the enzyme involving optimum temperature and pH for further application. Therefore, Disorder prediction-based truncation would be helpful to efficiently improve the enzyme activity and catalytic efficiency. PMID:27091115

  11. A universal and efficient method to compute maps from image-based prediction models.

    PubMed

    Sabuncu, Mert R

    2014-01-01

    Discriminative supervised learning algorithms, such as Support Vector Machines, are becoming increasingly popular in biomedical image computing. One of their main uses is to construct image-based prediction models, e.g., for computer aided diagnosis or "mind reading." A major challenge in these applications is the biological interpretation of the machine learning models, which can be arbitrarily complex functions of the input features (e.g., as induced by kernel-based methods). Recent work has proposed several strategies for deriving maps that highlight regions relevant for accurate prediction. Yet most of these methods o n strong assumptions about t he prediction model (e.g., linearity, sparsity) and/or data (e.g., Gaussianity), or fail to exploit the covariance structure in the data. In this work, we propose a computationally efficient and universal framework for quantifying associations captured by black box machine learning models. Furthermore, our theoretical perspective reveals that examining associations with predictions, in the absence of ground truth labels, can be very informative. We apply the proposed method to machine learning models trained to predict cognitive impairment from structural neuroimaging data. We demonstrate that our approach yields biologically meaningful maps of association. PMID:25320819

  12. A Validated Prediction Model for Overall Survival From Stage III Non-Small Cell Lung Cancer: Toward Survival Prediction for Individual Patients

    SciTech Connect

    Oberije, Cary; De Ruysscher, Dirk; Houben, Ruud; Heuvel, Michel van de; Uyterlinde, Wilma; Deasy, Joseph O.; Belderbos, Jose; Dingemans, Anne-Marie C.; Rimner, Andreas; Din, Shaun; Lambin, Philippe

    2015-07-15

    Purpose: Although patients with stage III non-small cell lung cancer (NSCLC) are homogeneous according to the TNM staging system, they form a heterogeneous group, which is reflected in the survival outcome. The increasing amount of information for an individual patient and the growing number of treatment options facilitate personalized treatment, but they also complicate treatment decision making. Decision support systems (DSS), which provide individualized prognostic information, can overcome this but are currently lacking. A DSS for stage III NSCLC requires the development and integration of multiple models. The current study takes the first step in this process by developing and validating a model that can provide physicians with a survival probability for an individual NSCLC patient. Methods and Materials: Data from 548 patients with stage III NSCLC were available to enable the development of a prediction model, using stratified Cox regression. Variables were selected by using a bootstrap procedure. Performance of the model was expressed as the c statistic, assessed internally and on 2 external data sets (n=174 and n=130). Results: The final multivariate model, stratified for treatment, consisted of age, gender, World Health Organization performance status, overall treatment time, equivalent radiation dose, number of positive lymph node stations, and gross tumor volume. The bootstrapped c statistic was 0.62. The model could identify risk groups in external data sets. Nomograms were constructed to predict an individual patient's survival probability ( (www.predictcancer.org)). The data set can be downloaded at (https://www.cancerdata.org/10.1016/j.ijrobp.2015.02.048). Conclusions: The prediction model for overall survival of patients with stage III NSCLC highlights the importance of combining patient, clinical, and treatment variables. Nomograms were developed and validated. This tool could be used as a first building block for a decision support system.

  13. How Plantar Exteroceptive Efficiency Modulates Postural and Oculomotor Control: Inter-Individual Variability

    PubMed Central

    Foisy, Arnaud; Kapoula, Zoï

    2016-01-01

    In a previous experiment, we showed that among young and healthy subjects, thin plantar inserts improve postural control and modify vergence amplitudes. In this experiment, however, significant inter-individual variability was observed. We hypothesize that its origin could be attributed to a different reliance upon feet cutaneous afferents. In order to test this hypothesis, we re-analyzed the data relative to 31 young (age 25.7 ± 3.8) and healthy subjects who participated in the first experiment after having classified them into two groups depending on their Plantar Quotient (PQ = Surface area of CoPfoam/Surface area of CoPfirm ground × 100). Foam decreases the information arising from the feet, normally resulting in a PQ > 100. Hence, the PQ provides information on the weight of plantar cutaneous afferents used in postural control. Twelve people were Plantar-Independent Subjects, as indicated by a PQ < 100. These individuals did not behave like the Normal Plantar Quotient Subjects: they were almost insensitive to the plantar stimulations in terms of postural control and totally insensitive in terms of oculomotor control. We conclude that the inter-individual variability observed in our first experiment is explained by the subjects' degree of plantar reliance. We propose that plantar independence is a dysfunctional situation revealing inefficiency in plantar cutaneous afferents. The latter could be due to a latent somatosensory dysfunction generating a noise which prevents the CNS from correctly processing and using feet somatosensory afferents both for balance and vergence control: Plantar Irritating Stimulus. Considering the non-noxious nature and prevalence of this phenomenon, these results can be of great interest to researchers and clinicians who attempt to trigger postural or oculomotor responses through mechanical stimulation of the foot sole. PMID:27242490

  14. How Plantar Exteroceptive Efficiency Modulates Postural and Oculomotor Control: Inter-Individual Variability.

    PubMed

    Foisy, Arnaud; Kapoula, Zoï

    2016-01-01

    In a previous experiment, we showed that among young and healthy subjects, thin plantar inserts improve postural control and modify vergence amplitudes. In this experiment, however, significant inter-individual variability was observed. We hypothesize that its origin could be attributed to a different reliance upon feet cutaneous afferents. In order to test this hypothesis, we re-analyzed the data relative to 31 young (age 25.7 ± 3.8) and healthy subjects who participated in the first experiment after having classified them into two groups depending on their Plantar Quotient (PQ = Surface area of CoPfoam/Surface area of CoPfirm ground × 100). Foam decreases the information arising from the feet, normally resulting in a PQ > 100. Hence, the PQ provides information on the weight of plantar cutaneous afferents used in postural control. Twelve people were Plantar-Independent Subjects, as indicated by a PQ < 100. These individuals did not behave like the Normal Plantar Quotient Subjects: they were almost insensitive to the plantar stimulations in terms of postural control and totally insensitive in terms of oculomotor control. We conclude that the inter-individual variability observed in our first experiment is explained by the subjects' degree of plantar reliance. We propose that plantar independence is a dysfunctional situation revealing inefficiency in plantar cutaneous afferents. The latter could be due to a latent somatosensory dysfunction generating a noise which prevents the CNS from correctly processing and using feet somatosensory afferents both for balance and vergence control: Plantar Irritating Stimulus. Considering the non-noxious nature and prevalence of this phenomenon, these results can be of great interest to researchers and clinicians who attempt to trigger postural or oculomotor responses through mechanical stimulation of the foot sole.

  15. Efficient Monte Carlo modelling of individual tumour cell propagation for hypoxic head and neck cancer

    NASA Astrophysics Data System (ADS)

    Tuckwell, W.; Bezak, E.; Yeoh, E.; Marcu, L.

    2008-09-01

    A Monte Carlo tumour model has been developed to simulate tumour cell propagation for head and neck squamous cell carcinoma. The model aims to eventually provide a radiobiological tool for radiation oncology clinicians to plan patient treatment schedules based on properties of the individual tumour. The inclusion of an oxygen distribution amongst the tumour cells enables the model to incorporate hypoxia and other associated parameters, which affect tumour growth. The object oriented program FORTRAN 95 has been used to create the model algorithm, with Monte Carlo methods being employed to randomly assign many of the cell parameters from probability distributions. Hypoxia has been implemented through random assignment of partial oxygen pressure values to individual cells during tumour growth, based on in vivo Eppendorf probe experimental data. The accumulation of up to 10 million virtual tumour cells in 15 min of computer running time has been achieved. The stem cell percentage and the degree of hypoxia are the parameters which most influence the final tumour growth rate. For a tumour with a doubling time of 40 days, the final stem cell percentage is approximately 1% of the total cell population. The effect of hypoxia on the tumour growth rate is significant. Using a hypoxia induced cell quiescence limit which affects 50% of cells with and oxygen levels less than 1 mm Hg, the tumour doubling time increases to over 200 days and the time of tumour growth for a clinically detectable tumour (109 cells) increases from 3 to 8 years. A biologically plausible Monte Carlo model of hypoxic head and neck squamous cell carcinoma tumour growth has been developed for real time assessment of the effects of multiple biological parameters which impact upon the response of the individual patient to fractionated radiotherapy.

  16. Efficient Monte Carlo modelling of individual tumour cell propagation for hypoxic head and neck cancer.

    PubMed

    Tuckwell, W; Bezak, E; Yeoh, E; Marcu, L

    2008-09-01

    A Monte Carlo tumour model has been developed to simulate tumour cell propagation for head and neck squamous cell carcinoma. The model aims to eventually provide a radiobiological tool for radiation oncology clinicians to plan patient treatment schedules based on properties of the individual tumour. The inclusion of an oxygen distribution amongst the tumour cells enables the model to incorporate hypoxia and other associated parameters, which affect tumour growth. The object oriented program FORTRAN 95 has been used to create the model algorithm, with Monte Carlo methods being employed to randomly assign many of the cell parameters from probability distributions. Hypoxia has been implemented through random assignment of partial oxygen pressure values to individual cells during tumour growth, based on in vivo Eppendorf probe experimental data. The accumulation of up to 10 million virtual tumour cells in 15 min of computer running time has been achieved. The stem cell percentage and the degree of hypoxia are the parameters which most influence the final tumour growth rate. For a tumour with a doubling time of 40 days, the final stem cell percentage is approximately 1% of the total cell population. The effect of hypoxia on the tumour growth rate is significant. Using a hypoxia induced cell quiescence limit which affects 50% of cells with and oxygen levels less than 1 mm Hg, the tumour doubling time increases to over 200 days and the time of tumour growth for a clinically detectable tumour (10(9) cells) increases from 3 to 8 years. A biologically plausible Monte Carlo model of hypoxic head and neck squamous cell carcinoma tumour growth has been developed for real time assessment of the effects of multiple biological parameters which impact upon the response of the individual patient to fractionated radiotherapy. PMID:18677039

  17. How Plantar Exteroceptive Efficiency Modulates Postural and Oculomotor Control: Inter-Individual Variability.

    PubMed

    Foisy, Arnaud; Kapoula, Zoï

    2016-01-01

    In a previous experiment, we showed that among young and healthy subjects, thin plantar inserts improve postural control and modify vergence amplitudes. In this experiment, however, significant inter-individual variability was observed. We hypothesize that its origin could be attributed to a different reliance upon feet cutaneous afferents. In order to test this hypothesis, we re-analyzed the data relative to 31 young (age 25.7 ± 3.8) and healthy subjects who participated in the first experiment after having classified them into two groups depending on their Plantar Quotient (PQ = Surface area of CoPfoam/Surface area of CoPfirm ground × 100). Foam decreases the information arising from the feet, normally resulting in a PQ > 100. Hence, the PQ provides information on the weight of plantar cutaneous afferents used in postural control. Twelve people were Plantar-Independent Subjects, as indicated by a PQ < 100. These individuals did not behave like the Normal Plantar Quotient Subjects: they were almost insensitive to the plantar stimulations in terms of postural control and totally insensitive in terms of oculomotor control. We conclude that the inter-individual variability observed in our first experiment is explained by the subjects' degree of plantar reliance. We propose that plantar independence is a dysfunctional situation revealing inefficiency in plantar cutaneous afferents. The latter could be due to a latent somatosensory dysfunction generating a noise which prevents the CNS from correctly processing and using feet somatosensory afferents both for balance and vergence control: Plantar Irritating Stimulus. Considering the non-noxious nature and prevalence of this phenomenon, these results can be of great interest to researchers and clinicians who attempt to trigger postural or oculomotor responses through mechanical stimulation of the foot sole. PMID:27242490

  18. Using Bench Press Load to Predict Upper Body Exercise Loads in Physically Active Individuals

    PubMed Central

    Wong, Del P.; Ngo, Kwan-Lung; Tse, Michael A.; Smith, Andrew W.

    2013-01-01

    This study investigated whether loads for assistance exercises of the upper body can be predicted from the loads of the bench press exercise. Twenty-nine physically active collegiate students (age: 22.6 ± 2.5; weight training experience: 2.9 ± 2.1 years; estimated 1RM bench press: 54.31 ± 14.60 kg; 1RM: body weight ratio: 0.80 ± 0.22; BMI: 22.7 ± 2.1 kg·m-2) were recruited. The 6RM loads for bench press, barbell bicep curl, overhead dumbbell triceps extension, hammer curl and dumbbell shoulder press were measured. Test-retest reliability for the 5 exercises as determined by Pearson product moment correlation coefficient was very high to nearly perfect (0.82-0.98, p < 0.01). The bench press load was significantly correlated with the loads of the 4 assistance exercises (r ranged from 0.80 to 0.93, p < 0.01). Linear regression revealed that the bench press load was a significant (R2 range from 0.64 to 0.86, p < 0.01) predictor for the loads of the 4 assistance exercises. The following 6RM prediction equations were determined: (a) Hammer curl = Bench press load (0.28) + 6.30 kg, (b) Barbell biceps curl = Bench press load (0.33) + 6.20 kg, (c) Overhead triceps extension = Bench press load (0.33) - 0.60 kg, and (d) Dumbbell shoulder press = Bench press load (0.42) + 5.84 kg. The difference between the actual load and the predicted load using the four equations ranged between 6.52% and 8.54%, such difference was not significant. Fitness professionals can use the 6RM bench press load as a time effective and accurate method to predict training loads for upper body assistance exercises. Key points The bench press load was significantly correlated with the loads of the 4 assistance exercises. No significant differences were found between the actual load and the predicted load in the four equations. 6RM bench press load can be a time effective and accurate method to predict training loads for upper body assistance exercises. PMID:24149723

  19. Model-based evaluation of subsurface monitoring networks for improved efficiency and predictive certainty of regional groundwater models

    NASA Astrophysics Data System (ADS)

    Gosses, M. J.; Wöhling, Th.; Moore, C. R.; Dann, R.; Scott, D. M.; Close, M.

    2012-04-01

    -specific prediction target under consideration. Therefore, the worth of individual observation locations may differ for different prediction targets. Our evaluation is based on predictions of lowland stream discharge resulting from changes in land use and irrigation in the upper Central Plains catchment. In our analysis, we adopt the model predictive uncertainty analysis method by Moore and Doherty (2005) which accounts for contributions from both measurement errors and uncertain structural heterogeneity. The method is robust and efficient due to a linearity assumption in the governing equations and readily implemented for application in the model-independent parameter estimation and uncertainty analysis toolkit PEST (Doherty, 2010). The proposed methods can be applied not only for the evaluation of monitoring networks, but also for the optimization of networks, to compare alternative monitoring strategies, as well as to identify best cost-benefit monitoring design even prior to any data acquisition.

  20. [Monitoring sheet covering long-term chemotherapy to predict individual adverse reaction patterns for patients with gynecologic chemotherapy].

    PubMed

    Doi, Chiaki; Iihara, Naomi; Kawazoe, Hitoshi; Fukuoka, Noriyasu; Houchi, Hitoshi; Kurosaki, Yuji; Morita, Shushi

    2007-06-01

    Monitoring the adverse reaction patterns specific to individual patients is important to avoid subsequent reactions. Gynecologic cancer chemotherapy is often implemented repeatedly with an altered protocol during prolonged terms. The purpose of this study was to develop and assess the efficacy of a worksheet that pharmacists can use to analyze adverse reaction patterns in individual patients with gynecologic chemotherapy. The worksheet which we developed consisted of multiple sections. One section is for necessary drug information for the proper use of antineoplastic agents. Another section is for the following items recorded by the pharmacists: a) patients' basic information such as stage of disease and protocol, b) state of implementation and break of chemotherapy and supportive therapy on calendar, and c) laboratory data and symptoms. We arranged the last item below the calendar and enabled pharmacists to easily assess individual adverse reactions coupled with the treatment course. Reviews of the developed worksheet indicated that the worksheet led to the convenient detection of individual adverse reaction patterns and effective prevention of additional adverse reactions. This monitoring sheet covering long-term chemotherapy which was designed to predict individual adverse reaction patterns will improve the individualization and safety of gynecologic chemotherapy.

  1. Identifying Individuals at High Risk of Psychosis: Predictive Utility of Support Vector Machine using Structural and Functional MRI Data

    PubMed Central

    Valli, Isabel; Marquand, Andre F.; Mechelli, Andrea; Raffin, Marie; Allen, Paul; Seal, Marc L.; McGuire, Philip

    2016-01-01

    The identification of individuals at high risk of developing psychosis is entirely based on clinical assessment, associated with limited predictive potential. There is, therefore, increasing interest in the development of biological markers that could be used in clinical practice for this purpose. We studied 25 individuals with an at-risk mental state for psychosis and 25 healthy controls using structural MRI, and functional MRI in conjunction with a verbal memory task. Data were analyzed using a standard univariate analysis, and with support vector machine (SVM), a multivariate pattern recognition technique that enables statistical inferences to be made at the level of the individual, yielding results with high translational potential. The application of SVM to structural MRI data permitted the identification of individuals at high risk of psychosis with a sensitivity of 68% and a specificity of 76%, resulting in an accuracy of 72% (p < 0.001). Univariate volumetric between-group differences did not reach statistical significance. By contrast, the univariate fMRI analysis identified between-group differences (p < 0.05 corrected), while the application of SVM to the same data did not. Since SVM is well suited at identifying the pattern of abnormality that distinguishes two groups, whereas univariate methods are more likely to identify regions that individually are most different between two groups, our results suggest the presence of focal functional abnormalities in the context of a diffuse pattern of structural abnormalities in individuals at high clinical risk of psychosis. PMID:27092086

  2. Identifying Individuals at High Risk of Psychosis: Predictive Utility of Support Vector Machine using Structural and Functional MRI Data.

    PubMed

    Valli, Isabel; Marquand, Andre F; Mechelli, Andrea; Raffin, Marie; Allen, Paul; Seal, Marc L; McGuire, Philip

    2016-01-01

    The identification of individuals at high risk of developing psychosis is entirely based on clinical assessment, associated with limited predictive potential. There is, therefore, increasing interest in the development of biological markers that could be used in clinical practice for this purpose. We studied 25 individuals with an at-risk mental state for psychosis and 25 healthy controls using structural MRI, and functional MRI in conjunction with a verbal memory task. Data were analyzed using a standard univariate analysis, and with support vector machine (SVM), a multivariate pattern recognition technique that enables statistical inferences to be made at the level of the individual, yielding results with high translational potential. The application of SVM to structural MRI data permitted the identification of individuals at high risk of psychosis with a sensitivity of 68% and a specificity of 76%, resulting in an accuracy of 72% (p < 0.001). Univariate volumetric between-group differences did not reach statistical significance. By contrast, the univariate fMRI analysis identified between-group differences (p < 0.05 corrected), while the application of SVM to the same data did not. Since SVM is well suited at identifying the pattern of abnormality that distinguishes two groups, whereas univariate methods are more likely to identify regions that individually are most different between two groups, our results suggest the presence of focal functional abnormalities in the context of a diffuse pattern of structural abnormalities in individuals at high clinical risk of psychosis. PMID:27092086

  3. Individual Differences in Rhythmic Cortical Entrainment Correlate with Predictive Behavior in Sensorimotor Synchronization

    PubMed Central

    Nozaradan, Sylvie; Peretz, Isabelle; Keller, Peter E.

    2016-01-01

    The current study aims at characterizing the mechanisms that allow humans to entrain the mind and body to incoming rhythmic sensory inputs in real time. We addressed this unresolved issue by examining the relationship between covert neural processes and overt behavior in the context of musical rhythm. We measured temporal prediction abilities, sensorimotor synchronization accuracy and neural entrainment to auditory rhythms as captured using an EEG frequency-tagging approach. Importantly, movement synchronization accuracy with a rhythmic beat could be explained by the amplitude of neural activity selectively locked with the beat period when listening to the rhythmic inputs. Furthermore, stronger endogenous neural entrainment at the beat frequency was associated with superior temporal prediction abilities. Together, these results reveal a direct link between cortical and behavioral measures of rhythmic entrainment, thus providing evidence that frequency-tagged brain activity has functional relevance for beat perception and synchronization. PMID:26847160

  4. Computational fluency and strategy choice predict individual and cross-national differences in complex arithmetic.

    PubMed

    Vasilyeva, Marina; Laski, Elida V; Shen, Chen

    2015-10-01

    The present study tested the hypothesis that children's fluency with basic number facts and knowledge of computational strategies, derived from early arithmetic experience, predicts their performance on complex arithmetic problems. First-grade students from United States and Taiwan (N = 152, mean age: 7.3 years) were presented with problems that differed in difficulty: single-, mixed-, and double-digit addition. Children's strategy use varied as a function of problem difficulty, consistent with Siegler's theory of strategy choice. The use of decomposition strategy interacted with computational fluency in predicting the accuracy of double-digit addition. Further, the frequency of decomposition and computational fluency fully mediated cross-national differences in accuracy on these complex arithmetic problems. The results indicate the importance of both fluency with basic number facts and the decomposition strategy for later arithmetic performance. PMID:26301447

  5. Computational fluency and strategy choice predict individual and cross-national differences in complex arithmetic.

    PubMed

    Vasilyeva, Marina; Laski, Elida V; Shen, Chen

    2015-10-01

    The present study tested the hypothesis that children's fluency with basic number facts and knowledge of computational strategies, derived from early arithmetic experience, predicts their performance on complex arithmetic problems. First-grade students from United States and Taiwan (N = 152, mean age: 7.3 years) were presented with problems that differed in difficulty: single-, mixed-, and double-digit addition. Children's strategy use varied as a function of problem difficulty, consistent with Siegler's theory of strategy choice. The use of decomposition strategy interacted with computational fluency in predicting the accuracy of double-digit addition. Further, the frequency of decomposition and computational fluency fully mediated cross-national differences in accuracy on these complex arithmetic problems. The results indicate the importance of both fluency with basic number facts and the decomposition strategy for later arithmetic performance.

  6. Brainstem White Matter Predicts Individual Differences in Manual Motor Difficulties and Symptom Severity in Autism

    PubMed Central

    Travers, Brittany G.; Bigler, Erin D.; Tromp, Do P. M.; Adluru, Nagesh; Destiche, Dan; Samsin, Danica; Froehlich, Alyson; Prigge, Molly D. B.; Duffield, Tyler; Lange, Nicholas; Alexander, Andrew L.; Lainhart, Janet E.

    2015-01-01

    Mounting evidence suggests that poorer motor skills may be related to more severe autism symptoms. This study investigated if atypical white matter microstructure in the brain mediated the relationship between motor skills and ASD symptom severity. Sixty-seven males with ASD and 42 males with typical development (5-33 years old) completed a diffusion tensor imaging scan and measures of grip strength, finger tapping, and autism symptom severity. Within the ASD group, weaker grip strength predicted more severe autism symptoms. Fractional anisotropy of the brainstem's corticospinal tract predicted both grip strength and autism symptom severity and mediated the relationship between the two. These findings suggest that brainstem white matter may contribute to autism symptoms and grip strength in ASD. PMID:26001365

  7. Brainstem White Matter Predicts Individual Differences in Manual Motor Difficulties and Symptom Severity in Autism.

    PubMed

    Travers, Brittany G; Bigler, Erin D; Tromp, Do P M; Adluru, Nagesh; Destiche, Dan; Samsin, Danica; Froehlich, Alyson; Prigge, Molly D B; Duffield, Tyler C; Lange, Nicholas; Alexander, Andrew L; Lainhart, Janet E

    2015-09-01

    Mounting evidence suggests that poorer motor skills may be related to more severe autism symptoms. This study investigated if atypical white matter microstructure in the brain mediated the relationship between motor skills and ASD symptom severity. Sixty-seven males with ASD and 42 males with typical development (5-33 years old) completed a diffusion tensor imaging scan and measures of grip strength, finger tapping, and autism symptom severity. Within the ASD group, weaker grip strength predicted more severe autism symptoms. Fractional anisotropy of the brainstem's corticospinal tract predicted both grip strength and autism symptom severity and mediated the relationship between the two. These findings suggest that brainstem white matter may contribute to autism symptoms and grip strength in ASD.

  8. Individual Differences in Rhythmic Cortical Entrainment Correlate with Predictive Behavior in Sensorimotor Synchronization.

    PubMed

    Nozaradan, Sylvie; Peretz, Isabelle; Keller, Peter E

    2016-01-01

    The current study aims at characterizing the mechanisms that allow humans to entrain the mind and body to incoming rhythmic sensory inputs in real time. We addressed this unresolved issue by examining the relationship between covert neural processes and overt behavior in the context of musical rhythm. We measured temporal prediction abilities, sensorimotor synchronization accuracy and neural entrainment to auditory rhythms as captured using an EEG frequency-tagging approach. Importantly, movement synchronization accuracy with a rhythmic beat could be explained by the amplitude of neural activity selectively locked with the beat period when listening to the rhythmic inputs. Furthermore, stronger endogenous neural entrainment at the beat frequency was associated with superior temporal prediction abilities. Together, these results reveal a direct link between cortical and behavioral measures of rhythmic entrainment, thus providing evidence that frequency-tagged brain activity has functional relevance for beat perception and synchronization. PMID:26847160

  9. Individual differences in selective attention predict speech identification at a cocktail party.

    PubMed

    Oberfeld, Daniel; Klöckner-Nowotny, Felicitas

    2016-01-01

    Listeners with normal hearing show considerable individual differences in speech understanding when competing speakers are present, as in a crowded restaurant. Here, we show that one source of this variance are individual differences in the ability to focus selective attention on a target stimulus in the presence of distractors. In 50 young normal-hearing listeners, the performance in tasks measuring auditory and visual selective attention was associated with sentence identification in the presence of spatially separated competing speakers. Together, the measures of selective attention explained a similar proportion of variance as the binaural sensitivity for the acoustic temporal fine structure. Working memory span, age, and audiometric thresholds showed no significant association with speech understanding. These results suggest that a reduced ability to focus attention on a target is one reason why some listeners with normal hearing sensitivity have difficulty communicating in situations with background noise. PMID:27580272

  10. Amygdala Volume Predicts Inter-Individual Differences in Fearful Face Recognition

    PubMed Central

    Zhao, Ke; Yan, Wen-Jing; Chen, Yu-Hsin; Zuo, Xi-Nian; Fu, Xiaolan

    2013-01-01

    The present study investigates the relationship between inter-individual differences in fearful face recognition and amygdala volume. Thirty normal adults were recruited and each completed two identical facial expression recognition tests offline and two magnetic resonance imaging (MRI) scans. Linear regression indicated that the left amygdala volume negatively correlated with the accuracy of recognizing fearful facial expressions and positively correlated with the probability of misrecognizing fear as surprise. Further exploratory analyses revealed that this relationship did not exist for any other subcortical or cortical regions. Nor did such a relationship exist between the left amygdala volume and performance recognizing the other five facial expressions. These mind-brain associations highlight the importance of the amygdala in recognizing fearful faces and provide insights regarding inter-individual differences in sensitivity toward fear-relevant stimuli. PMID:24009767

  11. Inter-individual differences in the experience of negative emotion predict variations in functional brain architecture.

    PubMed

    Petrican, Raluca; Saverino, Cristina; Shayna Rosenbaum, R; Grady, Cheryl

    2015-12-01

    Current evidence suggests that two spatially distinct neuroanatomical networks, the dorsal attention network (DAN) and the default mode network (DMN), support externally and internally oriented cognition, respectively, and are functionally regulated by a third, frontoparietal control network (FPC). Interactions among these networks contribute to normal variations in cognitive functioning and to the aberrant affective profiles present in certain clinical conditions, such as major depression. Nevertheless, their links to non-clinical variations in affective functioning are still poorly understood. To address this issue, we used fMRI to measure the intrinsic functional interactions among these networks in a sample of predominantly younger women (N=162) from the Human Connectome Project. Consistent with the previously documented dichotomous motivational orientations (i.e., withdrawal versus approach) associated with sadness versus anger, we hypothesized that greater sadness would predict greater DMN (rather than DAN) functional dominance, whereas greater anger would predict the opposite. Overall, there was evidence of greater DAN (rather than DMN) functional dominance, but this pattern was modulated by current experience of specific negative emotions, as well as subclinical depressive and anxiety symptoms. Thus, greater levels of currently experienced sadness and subclinical depression independently predicted weaker DAN functional dominance (i.e., weaker DAN-FPC functional connectivity), likely reflecting reduced goal-directed attention towards the external perceptual environment. Complementarily, greater levels of currently experienced anger and subclinical anxiety predicted greater DAN functional dominance (i.e., greater DAN-FPC functional connectivity and, for anxiety only, also weaker DMN-FPC coupling). Our findings suggest that distinct affective states and subclinical mood symptoms have dissociable neural signatures, reflective of the symbiotic relationship

  12. Prediction of interindividual variation in drug plasma levels in vivo from individual enzyme kinetic data and physiologically based pharmacokinetic modeling.

    PubMed

    Bogaards, J J; Hissink, E M; Briggs, M; Weaver, R; Jochemsen, R; Jackson, P; Bertrand, M; van Bladeren, P J

    2000-12-01

    A strategy is presented to predict interindividual variation in drug plasma levels in vivo by the use of physiologically based pharmacokinetic modeling and human in vitro metabolic parameters, obtained through the combined use of microsomes containing single cytochrome P450 enzymes and a human liver microsome bank. The strategy, applied to the pharmaceutical compound (N-[2-(7-methoxy-1-naphtyl)-ethyl]acetamide), consists of the following steps: (1) estimation of enzyme kinetic parameters K(m) and V(max) for the key cytochrome P450 enzymes using microsomes containing individual P450 enzymes; (2) scaling-up of the V(max) values for each individual cytochrome P450 involved using the ratio between marker substrate activities obtained from the same microsomes containing single P450 enzymes and a human liver microsome bank; (3) incorporation into a physiologically based pharmacokinetic model. For validation, predicted blood plasma levels and pharmacokinetic parameters were compared to those found in human volunteers: both the absolute plasma levels as well as the range in plasma levels were well predicted. Therefore, the presented strategy appears to be promising with respect to the integration of interindividual differences in metabolism and prediction of the possible impact on plasma and tissue concentrations of drugs in humans. PMID:11102739

  13. Age and Individual Foraging Behavior Predict Tooth Wear in Amboseli Baboons

    PubMed Central

    Galbany, Jordi; Altmann, Jeanne; Pérez-Pérez, Alejandro; Alberts, Susan C.

    2010-01-01

    Teeth represent an essential component of the foraging apparatus for any mammal, and tooth wear can have significant implications for survival and reproduction. This study focuses on tooth wear in wild baboons in Amboseli, southern Kenya. We obtained mandibular and maxillary tooth impressions from 95 baboons and analyzed digital images of replicas made from these impressions. We measured tooth wear as the percent dentine exposure (PDE, the percent of the occlusal surface on which dentine was exposed), and we examined the relationship of PDE to age, behavior, and life history variables. We found that PDE increased significantly with age for both sexes in all three molar types. In females, we also tested the hypotheses that long-term patterns of feeding behavior, social dominance rank, and one measure of maternal investment (the cumulative number of months that a female had dependent infants during her lifetime) would predict tooth wear when we controlled for age. The hypothesis that feeding behavior predicted tooth wear was supported. The percent of feeding time spent consuming grass corms predicted PDE when controlling for age. However, PDE was not associated with social dominance rank or maternal investment. Am J Phys Anthropol 000:000–000, 2010. PMID:20721946

  14. Individual differences in visual information processing rate and the prediction of performance differences in team sports: a preliminary investigation.

    PubMed

    Adam, J J; Wilberg, R B

    1992-06-01

    This study used a backward-masking paradigm to examine individual differences in rate of visual information processing among university basketball, ice hockey and Canadian football players. Displays containing four letters were presented for stimulus durations ranging from 25 to 300 ms. Following stimulus offset, a masking stimulus was presented for 200 ms. The subjects were instructed to write down as many letters as possible from the briefly presented stimulus display on a specially prepared response grid. The results indicated consistent individual differences in rate of visual information processing. More importantly, it was found that rate of visual information processing as indexed by the backward-masking technique, has promising validity for predicting general performance excellence in university ice hockey and basketball players. Individual differences in rate of visual information processing were interpreted as reflecting the operation of attentional factors.

  15. Connectivity strength of dissociable striatal tracts predict individual differences in temporal discounting.

    PubMed

    van den Bos, Wouter; Rodriguez, Christian A; Schweitzer, Julie B; McClure, Samuel M

    2014-07-30

    Large individual differences exist in the ability to delay gratification for the sake of satisfying longer-term goals. These individual differences are commonly assayed by studying intertemporal preferences, as revealed by choices between immediate and delayed rewards. In the brain, reward-based and goal-oriented decisions are believed to rely on the striatum and its interactions with other cortical and subcortical networks. However, it remains unknown which specific cortical-striatal tracts are involved in intertemporal decision making. We use connectivity analyses in both structural and functional MRI to further our understanding of the relationship between distinct corticostriatal networks and intertemporal preferences in humans. Our results revealed distinct striatal pathways that are differentially related to delay discounting. Structural and functional connectivity between striatum and lateral prefrontal cortex was associated with increased patience, whereas connectivity between subcortical areas and striatum was associated with increased impulsivity. These findings provide novel insights into how the anatomy and functioning of striatal circuits mediate individual differences in intertemporal choice. PMID:25080591

  16. The occurrence of individual slow waves in sleep is predicted by heart rate.

    PubMed

    Mensen, Armand; Zhang, Zhongxing; Qi, Ming; Khatami, Ramin

    2016-07-22

    The integration of near-infrared spectroscopy and electroencephalography measures presents an ideal method to study the haemodynamics of sleep. While the cortical dynamics and neuro-modulating influences affecting the transition from wakefulness to sleep is well researched, the assumption has been that individual slow waves, the hallmark of deep sleep, are spontaneously occurring cortical events. By creating event-related potentials from the NIRS recording, time-locked to the onset of thousands of individual slow waves, we show the onset of slow waves is phase-locked to an ongoing oscillation in the NIRS recording. This oscillation stems from the moment to moment fluctuations of light absorption caused by arterial pulsations driven by the heart beat. The same oscillating signal can be detected if the electrocardiogram is time-locked to the onset of the slow wave. The ongoing NIRS oscillation suggests that individual slow wave initiation is dependent on that signal, and not the other way round. However, the precise causal links remain speculative. We propose several potential mechanisms: that the heart-beat or arterial pulsation acts as a stimulus which evokes a down-state; local fluctuations in energy supply may lead to a network effect of hyperpolarization; that the arterial pulsations lead to corresponding changes in the cerebral-spinal-fluid which evokes the slow wave; or that a third neural generator, regulating heart rate and slow waves may be involved.

  17. Occipital Cortical Thickness Predicts Performance on Pitch and Musical Tasks in Blind Individuals

    PubMed Central

    Zatorre, Robert J.

    2012-01-01

    The behavioral and neurofunctional consequences of blindness often include performance enhancements and recruitment of occipital regions for nonvisual tasks. How the neuroanatomical changes resulting from this sensory loss relate to these functional changes is, however, less clear. Previous studies using cortical thickness (CT) measures have shown thicker occipital cortex in early-blind (EB) individuals compared with sighted controls. We hypothesized that this finding reflects the crossmodal plasticity often observed in blind individuals and thus could reflect behavioral adaptations. To address this issue, CT measures in blind (early and late) and sighted subjects were obtained along with several auditory behavioral measures in an attempt to relate behavioral and neuroanatomical changes. Group contrasts confirmed previous results in showing thicker occipital cortex in the EB. Regression analyses between CT measures across the whole brain of all blind individuals with the behavioral scores from 2 tasks in which EB subjects were superior (pitch and melody discrimination) showed that CT of occipital areas was directly related to behavioral enhancements. These findings constitute a compelling demonstration that anatomical changes in occipital areas are directly related to heightened behavioral abilities in the blind and hence support the idea that these anatomical features reflect adaptive compensatory plasticity. PMID:22095215

  18. Connectivity Strength of Dissociable Striatal Tracts Predict Individual Differences in Temporal Discounting

    PubMed Central

    Rodriguez, Christian A.; Schweitzer, Julie B.

    2014-01-01

    Large individual differences exist in the ability to delay gratification for the sake of satisfying longer-term goals. These individual differences are commonly assayed by studying intertemporal preferences, as revealed by choices between immediate and delayed rewards. In the brain, reward-based and goal-oriented decisions are believed to rely on the striatum and its interactions with other cortical and subcortical networks. However, it remains unknown which specific cortical-striatal tracts are involved in intertemporal decision making. We use connectivity analyses in both structural and functional MRI to further our understanding of the relationship between distinct corticostriatal networks and intertemporal preferences in humans. Our results revealed distinct striatal pathways that are differentially related to delay discounting. Structural and functional connectivity between striatum and lateral prefrontal cortex was associated with increased patience, whereas connectivity between subcortical areas and striatum was associated with increased impulsivity. These findings provide novel insights into how the anatomy and functioning of striatal circuits mediate individual differences in intertemporal choice. PMID:25080591

  19. Type of High School Predicts Academic Performance at University Better than Individual Differences

    PubMed Central

    2016-01-01

    Psychological correlates of academic performance have always been of high relevance to psychological research. The relation between psychometric intelligence and academic performance is one of the most consistent and well-established findings in psychology. It is hypothesized that intelligence puts a limit on what an individual can learn or achieve. Moreover, a growing body of literature indicates a relationship between personality traits and academic performance. This relationship helps us to better understand how an individual will learn or achieve their goals. The aim of this study is to further investigate the relationship between psychological correlates of academic performance by exploring the potentially moderating role of prior education. The participants in this study differed in the type of high school they attended. They went either to gymnasium, a general education type of high school that prepares students specifically for university studies, or to vocational school, which prepares students both for the labour market and for further studies. In this study, we used archival data of psychological testing during career guidance in the final year of high school, and information about the university graduation of those who received guidance. The psychological measures included intelligence, personality and general knowledge. The results show that gymnasium students had greater chances of performing well at university, and that this relationship exceeds the contribution of intelligence and personality traits to university graduation. Moreover, psychological measures did not interact with type of high school, which indicates that students from different school types do not profit from certain individual characteristics. PMID:27695073

  20. Individual Differences in Striatum Activity to Food Commercials Predict Weight Gain in Adolescents

    PubMed Central

    Yokum, Sonja; Gearhardt, Ashley N.; Harris, Jennifer L.; Brownell, Kelly D.; Stice, Eric

    2014-01-01

    Objective Adolescents view thousands of food commercials annually, but little is known about how individual differences in neural response to food commercials relate to weight gain. To add to our understanding of individual risk factors for unhealthy weight gain and environmental contributions to the obesity epidemic, we tested the associations between reward region (striatum and orbitofrontal cortex [OFC]) responsivity to food commercials and future change in Body Mass Index (BMI). Design and Methods Adolescents (N = 30) underwent a scan session at baseline while watching a television show edited to include 20 food commercials and 20 non-food commercials. BMI was measured at baseline and 1-year follow-up. Results Activation in the striatum, but not OFC, in response to food commercials relative to non-food commercials and in response to food commercials relative to the television show was positively associated with change in BMI over 1-year follow-up. Baseline BMI did not moderate these effects. Conclusions The results suggest that there are individual differences in neural susceptibility to food advertising. These findings highlight a potential mechanism for the impact of food marketing on adolescent obesity. PMID:25155745

  1. Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism.

    PubMed

    Fincher, Corey L; Thornhill, Randy; Murray, Damian R; Schaller, Mark

    2008-06-01

    Pathogenic diseases impose selection pressures on the social behaviour of host populations. In humans (Homo sapiens), many psychological phenomena appear to serve an antipathogen defence function. One broad implication is the existence of cross-cultural differences in human cognition and behaviour contingent upon the relative presence of pathogens in the local ecology. We focus specifically on one fundamental cultural variable: differences in individualistic versus collectivist values. We suggest that specific behavioural manifestations of collectivism (e.g. ethnocentrism, conformity) can inhibit the transmission of pathogens; and so we hypothesize that collectivism (compared with individualism) will more often characterize cultures in regions that have historically had higher prevalence of pathogens. Drawing on epidemiological data and the findings of worldwide cross-national surveys of individualism/collectivism, our results support this hypothesis: the regional prevalence of pathogens has a strong positive correlation with cultural indicators of collectivism and a strong negative correlation with individualism. The correlations remain significant even when controlling for potential confounding variables. These results help to explain the origin of a paradigmatic cross-cultural difference, and reveal previously undocumented consequences of pathogenic diseases on the variable nature of human societies.

  2. The occurrence of individual slow waves in sleep is predicted by heart rate

    PubMed Central

    Mensen, Armand; Zhang, Zhongxing; Qi, Ming; Khatami, Ramin

    2016-01-01

    The integration of near-infrared spectroscopy and electroencephalography measures presents an ideal method to study the haemodynamics of sleep. While the cortical dynamics and neuro-modulating influences affecting the transition from wakefulness to sleep is well researched, the assumption has been that individual slow waves, the hallmark of deep sleep, are spontaneously occurring cortical events. By creating event-related potentials from the NIRS recording, time-locked to the onset of thousands of individual slow waves, we show the onset of slow waves is phase-locked to an ongoing oscillation in the NIRS recording. This oscillation stems from the moment to moment fluctuations of light absorption caused by arterial pulsations driven by the heart beat. The same oscillating signal can be detected if the electrocardiogram is time-locked to the onset of the slow wave. The ongoing NIRS oscillation suggests that individual slow wave initiation is dependent on that signal, and not the other way round. However, the precise causal links remain speculative. We propose several potential mechanisms: that the heart-beat or arterial pulsation acts as a stimulus which evokes a down-state; local fluctuations in energy supply may lead to a network effect of hyperpolarization; that the arterial pulsations lead to corresponding changes in the cerebral-spinal-fluid which evokes the slow wave; or that a third neural generator, regulating heart rate and slow waves may be involved. PMID:27445083

  3. Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism

    PubMed Central

    Fincher, Corey L; Thornhill, Randy; Murray, Damian R; Schaller, Mark

    2008-01-01

    Pathogenic diseases impose selection pressures on the social behaviour of host populations. In humans (Homo sapiens), many psychological phenomena appear to serve an antipathogen defence function. One broad implication is the existence of cross-cultural differences in human cognition and behaviour contingent upon the relative presence of pathogens in the local ecology. We focus specifically on one fundamental cultural variable: differences in individualistic versus collectivist values. We suggest that specific behavioural manifestations of collectivism (e.g. ethnocentrism, conformity) can inhibit the transmission of pathogens; and so we hypothesize that collectivism (compared with individualism) will more often characterize cultures in regions that have historically had higher prevalence of pathogens. Drawing on epidemiological data and the findings of worldwide cross-national surveys of individualism/collectivism, our results support this hypothesis: the regional prevalence of pathogens has a strong positive correlation with cultural indicators of collectivism and a strong negative correlation with individualism. The correlations remain significant even when controlling for potential confounding variables. These results help to explain the origin of a paradigmatic cross-cultural difference, and reveal previously undocumented consequences of pathogenic diseases on the variable nature of human societies. PMID:18302996

  4. An efficient artificial bee colony algorithm with application to nonlinear predictive control

    NASA Astrophysics Data System (ADS)

    Ait Sahed, Oussama; Kara, Kamel; Benyoucef, Abousoufyane; Laid Hadjili, Mohamed

    2016-05-01

    In this paper a constrained nonlinear predictive control algorithm, that uses the artificial bee colony (ABC) algorithm to solve the optimization problem, is proposed. The main objective is to derive a simple and efficient control algorithm that can solve the nonlinear constrained optimization problem with minimal computational time. Indeed, a modified version, enhancing the exploring and the exploitation capabilities, of the ABC algorithm is proposed and used to design a nonlinear constrained predictive controller. This version allows addressing the premature and the slow convergence drawbacks of the standard ABC algorithm, using a modified search equation, a well-known organized distribution mechanism for the initial population and a new equation for the limit parameter. A convergence statistical analysis of the proposed algorithm, using some well-known benchmark functions is presented and compared with several other variants of the ABC algorithm. To demonstrate the efficiency of the proposed algorithm in solving engineering problems, the constrained nonlinear predictive control of the model of a Multi-Input Multi-Output industrial boiler is considered. The control performances of the proposed ABC algorithm-based controller are also compared to those obtained using some variants of the ABC algorithms.

  5. Competition versus planning in health care: implications for corporate and individual incentives, efficiency & control.

    PubMed

    Lee, K

    1991-01-01

    This paper is about the management of change; and, most especially, about the changing tides of thinking that health planning and, more latterly, competition could bring about desired change in the health industry towards cost containment, efficiency and control. Looking back over the decade of the 1980s, it was characterised, for many countries, as a real questioning of the role of the public sector in people's life, and--in terms of public/private provision--a re-examination of what is public and should be. Coupled with this inquiry was a growing belief that comprehensive health planning was too lofty a goal, and that however elegant in theory, its delivery in practice fell far short of its ideals. Attention has therefore focused on the workings of competitive markets, and the extent to which objectives of cost containment and economic efficiency can be better addressed through competition and internal markets. In reality, the mixed economy is the only policy option available to developed countries today. Public and private monopolies are frowned upon, and the search is on for intermediate possibilities that capture some of the advantages of markets without their disadvantages, and arrangements that motivate consumer choice and simultaneously yield efficiency in the production and distribution of health care. By way of illustration, this paper looks at a number of innovations taking place to address these issues; and, in the context of the UK, at the most recent government proposals in respect of self-governing trusts and GP budget holders, as illustrations of the move towards the internal market, or to managed competition. Not surprisingly, the two areas that feature large on the agenda are hospital (and community) information systems; and, the motivations, rewards and penalties of the provider institutions that deliver services, and the consumers and purchasers who will "buy" them. Whether the mould can and should be broken is left tantalisingly open in the

  6. Child abuse predicts adult PTSD symptoms among individuals diagnosed with intellectual disabilities

    PubMed Central

    Catani, Claudia; Sossalla, Iris M.

    2015-01-01

    Prior research has shown that people with intellectual disabilities (ID) are more likely to experience child abuse as well as other forms of traumatic or negative events later in life compared to the general population. Little is known however, about the association of these experiences with adult mental health in intellectually disabled individuals. The present study aimed to assess whether child abuse in families and institutions as well as other types of adverse life events, were associated with current posttraumatic stress disorder (PTSD) and depression symptoms in individuals with ID. We conducted clinical interviews which included standardized self-report measures for childhood abuse, PTSD, and depression in an unselected sample of 56 persons with a medical diagnosis of ID who were attending a specialized welfare center. The frequency of traumatic experiences was very high, with physical and emotional child abuse being the most common trauma types. 87% of the persons reported at least one aversive experience on the family violence spectrum, and 50% of the sample reported a violent physical attack later in adulthood. 25% were diagnosed with PTSD and almost 27% had a critical score on the depression scale. Physical and emotional child abuse was positively correlated with the amount of institutional violence and the number of general traumatic events, whereas childhood sexual abuse was related to the experience of intimate partner violence in adult life. A linear regression model revealed child abuse in the family to be the only significant independent predictor of PTSD symptom severity. The current findings underscore the central role of child maltreatment in the increased risk of further victimization and in the development of mental health problems in adulthood in intellectually disabled individuals. Our data have important clinical implications and demonstrate the need for targeted prevention and intervention programs that are tailored to the specific needs

  7. Child abuse predicts adult PTSD symptoms among individuals diagnosed with intellectual disabilities.

    PubMed

    Catani, Claudia; Sossalla, Iris M

    2015-01-01

    Prior research has shown that people with intellectual disabilities (ID) are more likely to experience child abuse as well as other forms of traumatic or negative events later in life compared to the general population. Little is known however, about the association of these experiences with adult mental health in intellectually disabled individuals. The present study aimed to assess whether child abuse in families and institutions as well as other types of adverse life events, were associated with current posttraumatic stress disorder (PTSD) and depression symptoms in individuals with ID. We conducted clinical interviews which included standardized self-report measures for childhood abuse, PTSD, and depression in an unselected sample of 56 persons with a medical diagnosis of ID who were attending a specialized welfare center. The frequency of traumatic experiences was very high, with physical and emotional child abuse being the most common trauma types. 87% of the persons reported at least one aversive experience on the family violence spectrum, and 50% of the sample reported a violent physical attack later in adulthood. 25% were diagnosed with PTSD and almost 27% had a critical score on the depression scale. Physical and emotional child abuse was positively correlated with the amount of institutional violence and the number of general traumatic events, whereas childhood sexual abuse was related to the experience of intimate partner violence in adult life. A linear regression model revealed child abuse in the family to be the only significant independent predictor of PTSD symptom severity. The current findings underscore the central role of child maltreatment in the increased risk of further victimization and in the development of mental health problems in adulthood in intellectually disabled individuals. Our data have important clinical implications and demonstrate the need for targeted prevention and intervention programs that are tailored to the specific needs

  8. An Individual-Based Diploid Model Predicts Limited Conditions Under Which Stochastic Gene Expression Becomes Advantageous.

    PubMed

    Matsumoto, Tomotaka; Mineta, Katsuhiko; Osada, Naoki; Araki, Hitoshi

    2015-01-01

    Recent studies suggest the existence of a stochasticity in gene expression (SGE) in many organisms, and its non-negligible effect on their phenotype and fitness. To date, however, how SGE affects the key parameters of population genetics are not well understood. SGE can increase the phenotypic variation and act as a load for individuals, if they are at the adaptive optimum in a stable environment. On the other hand, part of the phenotypic variation caused by SGE might become advantageous if individuals at the adaptive optimum become genetically less-adaptive, for example due to an environmental change. Furthermore, SGE of unimportant genes might have little or no fitness consequences. Thus, SGE can be advantageous, disadvantageous, or selectively neutral depending on its context. In addition, there might be a genetic basis that regulates magnitude of SGE, which is often referred to as "modifier genes," but little is known about the conditions under which such an SGE-modifier gene evolves. In the present study, we conducted individual-based computer simulations to examine these conditions in a diploid model. In the simulations, we considered a single locus that determines organismal fitness for simplicity, and that SGE on the locus creates fitness variation in a stochastic manner. We also considered another locus that modifies the magnitude of SGE. Our results suggested that SGE was always deleterious in stable environments and increased the fixation probability of deleterious mutations in this model. Even under frequently changing environmental conditions, only very strong natural selection made SGE adaptive. These results suggest that the evolution of SGE-modifier genes requires strict balance among the strength of natural selection, magnitude of SGE, and frequency of environmental changes. However, the degree of dominance affected the condition under which SGE becomes advantageous, indicating a better opportunity for the evolution of SGE in different genetic

  9. Quantitative Regression Models for the Prediction of Chemical Properties by an Efficient Workflow.

    PubMed

    Yin, Yongmin; Xu, Congying; Gu, Shikai; Li, Weihua; Liu, Guixia; Tang, Yun

    2015-10-01

    Rapid safety assessment is more and more needed for the increasing chemicals both in chemical industries and regulators around the world. The traditional experimental methods couldn't meet the current demand any more. With the development of the information technology and the growth of experimental data, in silico modeling has become a practical and rapid alternative for the assessment of chemical properties, especially for the toxicity prediction of organic chemicals. In this study, a quantitative regression workflow was built by KNIME to predict chemical properties. With this regression workflow, quantitative values of chemical properties can be obtained, which is different from the binary-classification model or multi-classification models that can only give qualitative results. To illustrate the usage of the workflow, two predictive models were constructed based on datasets of Tetrahymena pyriformis toxicity and Aqueous solubility. The qcv (2) and qtest (2) of 5-fold cross validation and external validation for both types of models were greater than 0.7, which implies that our models are robust and reliable, and the workflow is very convenient and efficient in prediction of various chemical properties. PMID:27490968

  10. Individual Differences in Crossmodal Brain Activity Predict Arcuate Fasciculus Connectivity in Developing Readers

    PubMed Central

    Gullick, Margaret M.; Booth, James R.

    2016-01-01

    Crossmodal integration of auditory and visual information, such as phonemes and graphemes, is a critical skill for fluent reading. Previous work has demonstrated that white matter connectivity along the arcuate fasciculus (AF) is predicted by reading skill and that crossmodal processing particularly activates the posterior STS (pSTS). However, the relationship between this crossmodal activation and white matter integrity has not been previously reported. We investigated the interrelationship of crossmodal integration, both in terms of behavioral performance and pSTS activity, with AF tract coherence using a rhyme judgment task in a group of 47 children with a range of reading abilities. We demonstrate that both response accuracy and pSTS activity for crossmodal (auditory–visual) rhyme judgments was predictive of fractional anisotropy along the left AF. Unimodal (auditory-only or visual-only) pSTS activity was not significantly related to AF connectivity. Furthermore, activity in other reading-related ROIs did not show the same AV-only AF coherence relationship, and AV pSTS activity was not related to connectivity along other language-related tracts. This study is the first to directly show that crossmodal brain activity is specifically related to connectivity in the AF, supporting its role in phoneme–grapheme integration ability. More generally, this study helps to define an interdependent neural network for reading-related integration. PMID:24456399

  11. Patient nostril microbial flora: individual-dependency and diversity precluding prediction of Staphylococcus aureus acquisition.

    PubMed

    Alvarez, A S; Remy, L; Allix-Béguec, C; Ligier, C; Dupont, C; Leminor, O; Lawrence, C; Supply, P; Guillemot, D; Gaillard, J L; Salomon, J; Herrmann, J-L

    2014-01-01

    The potential role of a patient's resident microbial flora in the risk of acquiring multiresistant bacteria (MRB) during hospitalization is unclear. We investigated this role by cross-sectional study of 103 patients at risk of acquisition of Staphylococcus aureus (SA), resistant (MRSA) or not (MSSA) to methicillin, recruited in four French hospitals. The flora was analysed by an exhaustive culture-based approach combined with molecular and/or mass-spectrometry-based identification, and SA strain typing. Forty-three of the 53 SA-negative patients at entry were followed for up to 52 weeks: 19 (44.2%) remained negative for SA and 24 (55.8%) became positive, including 19 (79%) who acquired an MSSA, four (17%) who acquired an MRSA and one who acquired both (4%). Fifty-one different species were identified among the 103 patients, of which two, Corynebacterium accolens and Staphylococcus haemolyticus (p = 0.02-0.01), were more prevalent in the absence of SA. However, the same number of patients carrying or not these two species acquired an MSSA/MRSA during follow-up, regardless of antibiotic treatment received. Clustering analysis showed that the microbial flora was highly specific to each patient, and not predictive for acquisition of MSSA/MRSA or not. Patient-specific microbial resident flora is not predictive of SA acquisition.

  12. Predicting Individual Action Switching in Covert and Continuous Interactive Tasks Using the Fluid Events Model.

    PubMed

    Radvansky, Gabriel A; D'Mello, Sidney K; Abbott, Robert G; Bixler, Robert E

    2016-01-01

    The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covert event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant's current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person's prior experience. Thus, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events. PMID:26858673

  13. Serum Uric Acid Predicts Progression of Subclinical Coronary Atherosclerosis in Individuals Without Renal Disease

    PubMed Central

    Rodrigues, Ticiana C.; Maahs, David M.; Johnson, Richard J.; Jalal, Diana I.; Kinney, Gregory L.; Rivard, Christopher; Rewers, Marian; Snell-Bergeon, Janet K.

    2010-01-01

    OBJECTIVE To examine uric acid (UA) as a possible predictor of the progression of coronary artery calcification (CAC) using data from the prospective Coronary Artery Calcification in Type 1 Diabetes (CACTI) Study. RESEARCH DESIGN AND METHODS CAC was measured by electron beam tomography at the baseline and at a follow-up 6.0 ± 0.5 years later. The study population included 443 participants with type 1 diabetes and 526 control subjects who were free of diagnosed coronary artery disease at baseline. The presence of renal disease was defined by the presence of albuminuria and/or low glomerular filtration rate. RESULTS In subjects without renal disease, serum UA predicted CAC progression (odds ratio 1.30 [95% CI 1.07–1.58], P = 0.007) independent of conventional cardiovascular risk factors including diabetes and the presence of metabolic syndrome. CONCLUSIONS Serum UA levels predict the progression of coronary atherosclerosis and may be useful in identifying who is at risk for vascular disease in the absence of significant chronic kidney disease. PMID:20798338

  14. Predicting Individual Action Switching in Covert and Continuous Interactive Tasks Using the Fluid Events Model

    PubMed Central

    Radvansky, Gabriel A.; D’Mello, Sidney K.; Abbott, Robert G.; Bixler, Robert E.

    2016-01-01

    The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covert event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant’s current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person’s prior experience. Thus, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events. PMID:26858673

  15. Predicting individual action switching in covert and continuous interactive tasks using the fluid events model

    DOE PAGESBeta

    Radvansky, Gabriel A.; D’Mello, Sidney K.; Abbott, Robert G.; Bixler, Robert E.

    2016-01-27

    The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covertmore » event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant’s current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person’s prior experience. Hence, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events.« less

  16. Eye Movements during Auditory Attention Predict Individual Differences in Dorsal Attention Network Activity

    PubMed Central

    Braga, Rodrigo M.; Fu, Richard Z.; Seemungal, Barry M.; Wise, Richard J. S.; Leech, Robert

    2016-01-01

    The neural mechanisms supporting auditory attention are not fully understood. A dorsal frontoparietal network of brain regions is thought to mediate the spatial orienting of attention across all sensory modalities. Key parts of this network, the frontal eye fields (FEF) and the superior parietal lobes (SPL), contain retinotopic maps and elicit saccades when stimulated. This suggests that their recruitment during auditory attention might reflect crossmodal oculomotor processes; however this has not been confirmed experimentally. Here we investigate whether task-evoked eye movements during an auditory task can predict the magnitude of activity within the dorsal frontoparietal network. A spatial and non-spatial listening task was used with on-line eye-tracking and functional magnetic resonance imaging (fMRI). No visual stimuli or cues were used. The auditory task elicited systematic eye movements, with saccade rate and gaze position predicting attentional engagement and the cued sound location, respectively. Activity associated with these separate aspects of evoked eye-movements dissociated between the SPL and FEF. However these observed eye movements could not account for all the activation in the frontoparietal network. Our results suggest that the recruitment of the SPL and FEF during attentive listening reflects, at least partly, overt crossmodal oculomotor processes during non-visual attention. Further work is needed to establish whether the network’s remaining contribution to auditory attention is through covert crossmodal processes, or is directly involved in the manipulation of auditory information. PMID:27242465

  17. Predicting Individual Action Switching in Covert and Continuous Interactive Tasks Using the Fluid Events Model.

    PubMed

    Radvansky, Gabriel A; D'Mello, Sidney K; Abbott, Robert G; Bixler, Robert E

    2016-01-01

    The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covert event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant's current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person's prior experience. Thus, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events.

  18. The effect of breed and individual heterosis on the feed efficiency, performance, and carcass characteristics of feedlot steers.

    PubMed

    Retallick, K M; Faulkner, D B; Rodriguez-Zas, S L; Nkrumah, J D; Shike, D W

    2013-11-01

    This study was conducted to evaluate maternal breed effects, direct breed effects, and individual heterosis on subsequent steer performance, carcass, and feed efficiency traits. This was a consecutive 2-yr trial using 158 steers. The same dam breeds, Angus (AN) and purebred Simmental (SM), were used both years. Also, the same AN and SM sires (n=11) were used both years. Steers were AN, SM, or AN×SM breed composition. Steers were managed similarly before weaning and early weaned at 56±9 d of age. Steers were then randomly allotted to pens and fed a common finishing ration. Contrasts were written to evaluate direct and maternal breed effects and individual heterosis in the PROC MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) using dam breed, sire breed, and year as fixed effects. Simmental direct breed effect resulted in a 26 kg heavier initial BW (P<0.05) and a 46 kg heavier final BW (P<0.05). Simmental maternal breed effect increased initial BW by 43.5 kg (P<0.05). Dry matter intake was not impacted by direct breed effects, maternal breed effects, or individual heterosis. Individual heterosis did improve G:F 3.4% (P<0.05) and residual BW gain 0.048 kg/d (P<0.05). Residual intake and BW gain tended (P=0.07) to improve as a result of individual heterosis. Residual feed intake (RFI) was impacted by direct breed effect with SM cattle having a more desirable RFI (P=0.05). Angus direct breed effect increased backfat (P<0.05) and improved marbling score by 126 units (P<0.05). Simmental direct breed effect increased LM area (P<0.05), had the highest HCW at 410 kg (P<0.05), and had the most desirable yield grade at 2.74 (P<0.05). Individual heterosis improved marbling score (P=0.05). Maternal breed effect increased HCW (P<0.05) as a result of the SM dam. Direct breed effects were present for performance, feed efficiency measures, and carcass traits. Overall, heterosis impacted feedlot performance, carcass characteristics, and feed efficiency, which impacts beef

  19. MOOD STATE PREDICTION FROM SPEECH OF VARYING ACOUSTIC QUALITY FOR INDIVIDUALS WITH BIPOLAR DISORDER

    PubMed Central

    Gideon, John; Provost, Emily Mower; McInnis, Melvin

    2016-01-01

    Speech contains patterns that can be altered by the mood of an individual. There is an increasing focus on automated and distributed methods to collect and monitor speech from large groups of patients suffering from mental health disorders. However, as the scope of these collections increases, the variability in the data also increases. This variability is due in part to the range in the quality of the devices, which in turn affects the quality of the recorded data, negatively impacting the accuracy of automatic assessment. It is necessary to mitigate variability effects in order to expand the impact of these technologies. This paper explores speech collected from phone recordings for analysis of mood in individuals with bipolar disorder. Two different phones with varying amounts of clipping, loudness, and noise are employed. We describe methodologies for use during preprocessing, feature extraction, and data modeling to correct these differences and make the devices more comparable. The results demonstrate that these pipeline modifications result in statistically significantly higher performance, which highlights the potential of distributed mental health systems. PMID:27570493

  20. Individual differences in anxiety predict neural measures of visual working memory for untrustworthy faces.

    PubMed

    Meconi, Federica; Luria, Roy; Sessa, Paola

    2014-12-01

    When facing strangers, one of the first evaluations people perform is to implicitly assess their trustworthiness. However, the underlying processes supporting trustworthiness appraisal are poorly understood. We hypothesized that visual working memory (VWM) maintains online face representations that are sensitive to physical cues of trustworthiness, and that differences among individuals in representing untrustworthy faces are associated with individual differences in anxiety. Participants performed a change detection task that required encoding and maintaining for a short interval the identity of one face parametrically manipulated to be either trustworthy or untrustworthy. The sustained posterior contralateral negativity (SPCN), an event-related component (ERP) time-locked to the onset of the face, was used to index the resolution of face representations in VWM. Results revealed greater SPCN amplitudes for trustworthy faces when compared with untrustworthy faces, indicating that VWM is sensitive to physical cues of trustworthiness, even in the absence of explicit trustworthiness appraisal. In addition, differences in SPCN amplitude between trustworthy and untrustworthy faces correlated with participants' anxiety, indicating that healthy college students with sub-clinical high anxiety levels represented untrustworthy faces in greater detail compared with students with sub-clinical low anxiety levels. This pattern of findings is discussed in terms of the high flexibility of aversive/avoidance and appetitive/approach motivational systems. PMID:24493843

  1. Glutamate and choline levels predict individual differences in reading ability in emergent readers.

    PubMed

    Pugh, Kenneth R; Frost, Stephen J; Rothman, Douglas L; Hoeft, Fumiko; Del Tufo, Stephanie N; Mason, Graeme F; Molfese, Peter J; Mencl, W Einar; Grigorenko, Elena L; Landi, Nicole; Preston, Jonathan L; Jacobsen, Leslie; Seidenberg, Mark S; Fulbright, Robert K

    2014-03-12

    Reading disability is a brain-based difficulty in acquiring fluent reading skills that affects significant numbers of children. Although neuroanatomical and neurofunctional networks involved in typical and atypical reading are increasingly well characterized, the underlying neurochemical bases of individual differences in reading development are virtually unknown. The current study is the first to examine neurochemistry in children during the critical period in which the neurocircuits that support skilled reading are still developing. In a longitudinal pediatric sample of emergent readers whose reading indicators range on a continuum from impaired to superior, we examined the relationship between individual differences in reading and reading-related skills and concentrations of neurometabolites measured using magnetic resonance spectroscopy. Both continuous and group analyses revealed that choline and glutamate concentrations were negatively correlated with reading and related linguistic measures in phonology and vocabulary (such that higher concentrations were associated with poorer performance). Correlations with behavioral scores obtained 24 months later reveal stability for the relationship between glutamate and reading performance. Implications for neurodevelopmental models of reading and reading disability are discussed, including possible links of choline and glutamate to white matter anomalies and hyperexcitability. These findings point to new directions for research on gene-brain-behavior pathways in human studies of reading disability.

  2. Genetic marker of norepinephrine synthesis predicts individual differences in post-error slowing: a pilot study.

    PubMed

    Colzato, Lorenza S; de Rover, Mischa; van den Wildenberg, Wery P M; Nieuwenhuis, Sander

    2013-11-01

    When our brain detects the commission of an error, we slow down immediately thereafter: a phenomenon called post-error slowing (PES). Some researchers have speculated that slowing after unexpected errors or negative feedback is related to the activity of the neuromodulatory locus coeruleus-norepinephrine system. In the present pilot study, we tested whether individual differences in the size of PES are related to differences in genetic predisposition related to norepinephrine synthesis. In a sample of 100 healthy adults, we studied the dependency of an individual's size of PES on the DBH5'-ins/del polymorphism-a variation in the DBH gene associated with the production of the enzyme dopamine β-hydroxylase, which catalyzes the conversion of dopamine to norepinephrine. DBH5'-ins/del heterozygotes, who have intermediate levels of plasma DβH activity, showed increased PES in a Simon task compared to del/del homozygotes and ins/ins homozygotes, who have low and high levels of plasma DβH activity, respectively. This outcome pattern presents preliminary evidence that the size of PES varies with DβH activity and, presumably, NE release according to an inverted U-shape: intermediate levels of DβH activity and NE release are associated with larger post-error adjustments. PMID:23962674

  3. Societal individualism predicts prevalence of nonhomosexual orientation in male-to-female transsexualism.

    PubMed

    Lawrence, Anne A

    2010-04-01

    There are two distinct subtypes of male-to-female (MtF) transsexuals: homosexual and nonhomosexual. The relative prevalence of these two subtypes varies dramatically between countries, but no explanation of this variability has yet been proposed. This study examined the hypothesis that the prevalence of nonhomosexual MtF transsexualism, relative to homosexual MtF transsexualism, would be higher in individualistic countries than in collectivistic countries. I analyzed data from 22 studies of MtF transsexualism, conducted in 16 countries, examining the association between percentage of nonhomosexual participants and Hofstede's (Culture's consequences: Comparing values, behaviors, institutions, and organizations across nations, 2001) Individualism Index (IDV). IDV accounted for 77% of observed variance in the percentage of nonhomosexual MtF participants (r = 0.88, p < .0001). Controlling for differences in national wealth and in Hofstede's other indices of societal values (Power Distance, Uncertainty Avoidance, and Masculinity) did not significantly change the ability of IDV to account for variance in the percentage of nonhomosexual participants. The factors that contribute to the observed association between societal individualism and the relative prevalence of nonhomosexual MtF transsexualism remain to be determined, but a greater tolerance within individualistic countries for socially disruptive gender transitions by nonhomosexual gender dysphoric men, and the availability within many collectivistic countries of socially approved transgender roles for pervasively feminine homosexual gender dysphoric men, are plausible contributors.

  4. Interrelationships between trait anxiety, situational stress and mental effort predict phonological processing efficiency, but not effectiveness.

    PubMed

    Edwards, Elizabeth J; Edwards, Mark S; Lyvers, Michael

    2016-08-01

    Attentional control theory (ACT) describes the mechanisms associated with the relationship between anxiety and cognitive performance. We investigated the relationship between cognitive trait anxiety, situational stress and mental effort on phonological performance using a simple (forward-) and complex (backward-) word span task. Ninety undergraduate students participated in the study. Predictor variables were cognitive trait anxiety, indexed using questionnaire scores; situational stress, manipulated using ego threat instructions; and perceived level of mental effort, measured using a visual analogue scale. Criterion variables (a) performance effectiveness (accuracy) and (b) processing efficiency (accuracy divided by response time) were analyzed in separate multiple moderated-regression analyses. The results revealed (a) no relationship between the predictors and performance effectiveness, and (b) a significant 3-way interaction on processing efficiency for both the simple and complex tasks, such that at higher effort, trait anxiety and situational stress did not predict processing efficiency, whereas at lower effort, higher trait anxiety was associated with lower efficiency at high situational stress, but not at low situational stress. Our results were in full support of the assumptions of ACT and implications for future research are discussed. (PsycINFO Database Record PMID:27045685

  5. Adaptive Measurement of Well-Being: Maximizing Efficiency and Optimizing User Experience during Individual Assessment.

    PubMed

    Kraatz, Miriam; Sears, Lindsay E; Coberley, Carter R; Pope, James E

    2016-08-01

    Well-being is linked to important societal factors such as health care costs and productivity and has experienced a surge in development activity of both theories and measurement. This study builds on validation of the Well-Being 5 survey and for the first time applies Item Response Theory, a modern and flexible measurement paradigm, to form the basis of adaptive population well-being measurement. Adaptive testing allows survey questions to be administered selectively, thereby reducing the number of questions required of the participant. After the graded response model was fit to a sample of size N = 12,035, theta scores were estimated based on both the full-item bank and a simulation of Computerized Adaptive Testing (CAT). Comparisons of these 2 sets of score estimates with each other and of their correlations with external outcomes of job performance, absenteeism, and hospital admissions demonstrate that the CAT well-being scores maintain accuracy and validity. The simulation indicates that the average survey taker can expect a reduction in number of items administered during the CAT process of almost 50%. An increase in efficiency of this extent is of considerable value because of the time savings during the administration of the survey and the potential improvement of user experience, which in turn can help secure the success of a total population-based well-being improvement program. (Population Health Management 2016;19:284-290).

  6. Adaptive Measurement of Well-Being: Maximizing Efficiency and Optimizing User Experience during Individual Assessment

    PubMed Central

    Kraatz, Miriam; Coberley, Carter R.; Pope, James E.

    2016-01-01

    Abstract Well-being is linked to important societal factors such as health care costs and productivity and has experienced a surge in development activity of both theories and measurement. This study builds on validation of the Well-Being 5 survey and for the first time applies Item Response Theory, a modern and flexible measurement paradigm, to form the basis of adaptive population well-being measurement. Adaptive testing allows survey questions to be administered selectively, thereby reducing the number of questions required of the participant. After the graded response model was fit to a sample of size N = 12,035, theta scores were estimated based on both the full-item bank and a simulation of Computerized Adaptive Testing (CAT). Comparisons of these 2 sets of score estimates with each other and of their correlations with external outcomes of job performance, absenteeism, and hospital admissions demonstrate that the CAT well-being scores maintain accuracy and validity. The simulation indicates that the average survey taker can expect a reduction in number of items administered during the CAT process of almost 50%. An increase in efficiency of this extent is of considerable value because of the time savings during the administration of the survey and the potential improvement of user experience, which in turn can help secure the success of a total population-based well-being improvement program. (Population Health Management 2016;19:284–290) PMID:26674396

  7. Limits to prediction of energy balance from milk composition measures at individual cow level.

    PubMed

    Løvendahl, P; Ridder, C; Friggens, N C

    2010-05-01

    Frequently updated energy balance (EB) estimates for individual cows are especially useful for dairy herd management, and individual-level estimates form the basis for group-level EB estimates. The accuracy of EB estimates determines the value of this information for management decision support. This study aimed to assess EB accuracy through ANOVA components and by comparing EB estimates based either on milk composition (EBalMilk) or on body condition score (BCS) and body weight (BW) (EBalBody). Energy balance based on milk composition was evaluated using data in which milk composition was measured at each milking. Three breeds (Danish Red, Holstein-Friesian, and Jersey) of cows (299 cows, 623 lactations) in parities 1 to 4 were used. Milk data were smoothed using a rolling local regression. Energy balance based on milk composition was calculated using a partial least squares (PLS) model based on milk fat, protein, and lactose contents and yields, and the daily change in these variables at each day. Energy balance based on BCS and BW was calculated from changes in body condition and BW scored weekly or fortnightly. Equations for calculation of EBalMilk and EBalBody used no common variables and were, therefore, assumed mathematically independent. Traits were analyzed within 3 stages of lactation expected to have high mobilization of body tissue (1, early), almost balanced (2), and deposition of body energy (3, mid to late lactation). In general, EBalMilk and EBalBody followed similar expected changes through lactation. Estimates of covariance were obtained using single-trait mixed models with random regression terms describing the change with time and used for calculation of repeatability as intraclass correlations. Within stage, EBalMilk was less repeatable than EBalBody (0.53, 0.41, 0.43 vs. 0.93, 0.91, 0.86, respectively, for stages 1, 2, and 3), mainly because of a larger residual variance for EBalMilk. Correlations between individual-level estimates of EBal

  8. Prediction of Functional Outcome in Individuals at Clinical High Risk for Psychosis

    PubMed Central

    Carrión, Ricardo E.; McLaughlin, Danielle; Goldberg, Terry E.; Auther, Andrea M.; Olsen, Ruth H.; Olvet, Doreen M.; Correll, Christoph U.; Cornblatt, Barbara A.

    2014-01-01

    Importance A major public health concern associated with schizophrenia and psychotic disorders is the long-term disability that involves impaired cognition, lack of social support, and an inability to function independently in the community. A critical goal of early detection and intervention studies in psychosis is therefore to understand the factors leading to this often profound impairment. Objective To develop a predictive model of functional (social and role) outcome in a clinical high-risk sample for psychosis. Design Prospective, naturalistic, longitudinal 3- to 5-year follow-up study. Setting The Recognition and Prevention Program in New York, a research clinic located in the Zucker Hillside Hospital in New York. Participants One hundred one treatment-seeking patients at clinical high risk for psychosis. Ninety-two (91%) were followed up prospectively for a mean (SD) of 3 (1.6) years. Intervention Neurocognitive and clinical assessment. Main Outcomes and Measures The primary outcome variables were social and role functioning at the last follow-up visit. Results Poor social outcome was predicted by reduced processing speed (odds ratio [OR], 1.38; 95% CI, 1.050-1.823; P = .02), impaired social functioning at baseline (OR, 1.85; 95% CI, 1.258-2.732; P = .002), and total disorganized symptoms (OR, 5.06; 95% CI, 1.548-16.527; P = .007). Reduced performance on tests for verbal memory (OR, 1.74; 95% CI, 1.169-2.594; P = .006), role functioning at baseline (OR, 1.34; 95% CI, 1.053-1.711; P = .02), and motor disturbances (OR, 1.77; 95% CI, 1.060-2.969; P = .03) predicted role outcome. The areas under the curve for the social and role prediction models were 0.824 (95% CI, 0.736-0.913; P < .001) and 0.77 (95% CI, 0.68-0.87; P < .001), respectively, demonstrating a high discriminative ability. In addition, poor functional outcomes were not entirely dependent on the development of psychosis, because 40.3% and 45.5% of nonconverters at clinical high risk had poor social

  9. Prediction of individual differences in risky behavior in young adults via variations in local brain structure

    PubMed Central

    Nasiriavanaki, Zahra; ArianNik, Mohsen; Abbassian, Abdolhosein; Mahmoudi, Elham; Roufigari, Neda; Shahzadi, Sohrab; Nasiriavanaki, Mohammadreza; Bahrami, Bahador

    2015-01-01

    In recent years the problem of how inter-individual differences play a role in risk-taking behavior has become a much debated issue. We investigated this problem based on the well-known balloon analog risk task (BART) in 48 healthy subjects in which participants inflate a virtual balloon opting for a higher score in the face of a riskier chance of the balloon explosion. In this study, based on a structural Voxel Based Morphometry (VBM) technique we demonstrate a significant positive correlation between BART score and size of the gray matter volume in the anterior insula in riskier subjects. Although the anterior insula is among the candidate brain areas that were involved in the risk taking behavior in fMRI studies, here based on our structural data it is the only area that was significantly related to structural variation among different subjects. PMID:26500482

  10. Individual personalities predict social behaviour in wild networks of great tits (Parus major).

    PubMed

    Aplin, L M; Farine, D R; Morand-Ferron, J; Cole, E F; Cockburn, A; Sheldon, B C

    2013-11-01

    Social environments have an important effect on a range of ecological processes, and form a crucial component of selection. However, little is known of the link between personality, social behaviour and population structure. We combine a well-understood personality trait with large-scale social networks in wild songbirds, and show that personality underpins multiple aspects of social organisation. First, we demonstrate a relationship between network centrality and personality with 'proactive' (fast-exploring) individuals associating weakly with greater numbers of conspecifics and moving between flocks. Second, temporal stability of associations relates to personality: 'reactive' (slow-exploring) birds form synergistically stable relationships. Finally, we show that personality influences social structure, with males non-randomly distributed across groups. These results provide strong evidence that songbirds follow alternative social strategies related to personality. This has implications not only for the causes of social network structure but also for the strength and direction of selection on personality in natural populations. PMID:24047530

  11. Individual Differences in Risk Preference Predict Neural Responses during Financial Decision-Making

    PubMed Central

    Engelmann, Jan B.; Tamir, Diana

    2009-01-01

    We investigated the neural correlates of subjective valuations during a task involving risky choices about lotteries. Because expected value was held constant across all lotteries, decisions were influenced by subjective preferences, which manifest behaviorally as risk-seeking or risk-averse attitudes. To isolate structures encoding risk preference during choice, we probed for areas showing increased activation as a function of selected risk-level. Such response patterns were obtained in anterior (ACC) and posterior cingulate cortex (PCC), superior frontal gyrus, caudate nucleus, and substantia nigra. Behavioral results revealed the presence of risk-averse and risk-neutral individuals. In parallel, brain signals revealed modulation of activity by risk-attitude during choice. Correlations between risk-seeking attitudes and neural activity during risky choice were obtained in superior and inferior frontal gyri, medial and lateral orbitofrontal cortex, and parahippocampal gyrus, while correlations with risk-averse attitudes were found in the caudate. The dynamics of neural responses relevant to each stage of the task (decision, anticipation, outcome) were investigated via timeseries and conjunction analyses. Though the networks engaged in each of the task stages were mostly distinct, regions of ACC, PCC and caudate were consistently activated during each decision-making phase. These results demonstrate (1) that subjective assessments of risk, as well as individual attitudes toward risk, play a significant role in modulating activity within brain regions recruited during decision-making, and (2) that ACC, PCC and caudate are relevant during each phase of a decision-making task requiring subjective valuations, strengthening the role of these regions in self-referential subjective valuations during choice. PMID:19576868

  12. Do personality traits predict individual differences in excitatory and inhibitory learning?

    PubMed

    He, Zhimin; Cassaday, Helen J; Bonardi, Charlotte; Bibby, Peter A

    2013-01-01

    Conditioned inhibition (CI) is demonstrated in classical conditioning when a stimulus is used to signal the omission of an otherwise expected outcome. This basic learning ability is involved in a wide range of normal behavior - and thus its disruption could produce a correspondingly wide range of behavioral deficits. The present study employed a computer-based task to measure conditioned excitation and inhibition in the same discrimination procedure. CI by summation test was clearly demonstrated. Additionally summary measures of excitatory and inhibitory learning (difference scores) were calculated in order to explore how performance related to individual differences in a large sample of normal participants (n = 176 following exclusion of those not meeting the basic learning criterion). The individual difference measures selected derive from two biologically based personality theories, Gray's (1982) reinforcement sensitivity theory and Eysenck and Eysenck (1991) psychoticism, extraversion, and neuroticism theory. Following the behavioral tasks, participants completed the behavioral inhibition system/behavioral activation system (BIS/BAS) scales and the Eysenck personality questionnaire revised short scale (EPQ-RS). Analyses of the relationship between scores on each of the scales and summary measures of excitatory and inhibitory learning suggested that those with higher BAS (specifically the drive sub-scale) and higher EPQ-RS neuroticism showed reduced levels of excitatory conditioning. Inhibitory conditioning was similarly attenuated in those with higher EPQ-RS neuroticism, as well as in those with higher BIS scores. Thus the findings are consistent with higher levels of neuroticism being accompanied by generally impaired associative learning, both inhibitory and excitatory. There was also evidence for some dissociation in the effects of behavioral activation and behavioral inhibition on excitatory and inhibitory learning respectively.

  13. Transcriptome profiling of patient-specific human iPSC-cardiomyocytes predicts individual drug safety and efficacy responses in vitro

    PubMed Central

    Matsa, Elena; Burridge, Paul W.; Yu, Kun-Hsing; Ahrens, John H.; Termglinchan, Vittavat; Wu, Haodi; Liu, Chun; Shukla, Praveen; Sayed, Nazish; Churko, Jared M.; Shao, Ningyi; Woo, Nicole A.; Chao, Alexander S.; Gold, Joseph D.; Karakikes, Ioannis; Snyder, Michael P.; Wu, Joseph C.

    2016-01-01

    SUMMARY Understanding individual susceptibility to drug-induced cardiotoxicity is key to improving patient safety and preventing drug attrition. Human induced pluripotent stem cells (hiPSCs) enable the study of pharmacological and toxicological responses in patient-specific cardiomyocytes (CMs), and may serve as preclinical platforms for precision medicine. Transcriptome profiling in hiPSC-CMs from seven individuals lacking known cardiovascular disease-associated mutations, and in three isogenic human heart tissue and hiPSC-CM pairs, showed greater inter-patient variation than intra-patient variation, verifying that reprogramming and differentiation preserve patient-specific gene expression, particularly in metabolic and stress-response genes. Transcriptome-based toxicology analysis predicted and risk-stratified patient-specific susceptibility to cardiotoxicity, and functional assays in hiPSC-CMs using tacrolimus and rosiglitazone, drugs targeting pathways predicted to produce cardiotoxicity, validated inter-patient differential responses. CRISPR/Cas9-mediated pathway correction prevented drug-induced cardiotoxicity. Our data suggest that hiPSC-CMs can be used in vitro to predict and validate patient-specific drug safety and efficacy, potentially enabling future clinical approaches to precision medicine. PMID:27545504

  14. Do the Big Five personality traits predict individual differences in the left cheek bias for emotion perception?

    PubMed

    Galea, Samantha; Lindell, Annukka K

    2016-01-01

    Like language, emotion is a lateralized function. Because the right hemisphere typically dominates emotion processing, people express stronger emotion on the left side of their face. This prompts a left cheek bias: we offer the left cheek to express emotion and rate left cheek portraits more emotionally expressive than right cheek portraits. Though the majority of the population show this left cheek bias (60-70%), individual differences exist but remain largely unexplained. Given that people with higher self-rated emotional expressivity show a stronger left cheek bias, personality variables associated with increased emotional expressivity and emotional intelligence, such as extraversion and openness, may help account for individual differences. The present study thus examined whether the Big Five traits predict left cheek preferences. Participants (M = 58, F = 116) completed the NEO-Five Factor Personality Inventory (NEO-FFI) [Costa, P. T. J., & McCrae, R. R. (1992). NEO PI-R professional manual. Odessa, FL: Psychological Assessment Resources] and viewed pairs of left and right cheek images (half mirror-reversed); participants made forced-choice decisions, indicating which image in each pair looked happier. Hierarchical regression indicated that neither trait extraversion nor openness predicted left cheek selections, with NEO-FFI personality subscales accounting for negligible variance in preferences. As the Big Five traits have been discounted, exploration of other potential contributors to individual differences in the left cheek bias is clearly needed. PMID:26931139

  15. Do the Big Five personality traits predict individual differences in the left cheek bias for emotion perception?

    PubMed

    Galea, Samantha; Lindell, Annukka K

    2016-01-01

    Like language, emotion is a lateralized function. Because the right hemisphere typically dominates emotion processing, people express stronger emotion on the left side of their face. This prompts a left cheek bias: we offer the left cheek to express emotion and rate left cheek portraits more emotionally expressive than right cheek portraits. Though the majority of the population show this left cheek bias (60-70%), individual differences exist but remain largely unexplained. Given that people with higher self-rated emotional expressivity show a stronger left cheek bias, personality variables associated with increased emotional expressivity and emotional intelligence, such as extraversion and openness, may help account for individual differences. The present study thus examined whether the Big Five traits predict left cheek preferences. Participants (M = 58, F = 116) completed the NEO-Five Factor Personality Inventory (NEO-FFI) [Costa, P. T. J., & McCrae, R. R. (1992). NEO PI-R professional manual. Odessa, FL: Psychological Assessment Resources] and viewed pairs of left and right cheek images (half mirror-reversed); participants made forced-choice decisions, indicating which image in each pair looked happier. Hierarchical regression indicated that neither trait extraversion nor openness predicted left cheek selections, with NEO-FFI personality subscales accounting for negligible variance in preferences. As the Big Five traits have been discounted, exploration of other potential contributors to individual differences in the left cheek bias is clearly needed.

  16. Meta-analysis of genome-wide association studies: no efficiency gain in using individual participant data.

    PubMed

    Lin, D Y; Zeng, D

    2010-01-01

    To identify genetic variants with modest effects on complex human diseases, a growing number of networks or consortia are created for sharing data from multiple genome-wide association studies on the same disease or related disorders. A central question in this enterprise is whether to obtain summary results or individual participant data from relevant studies. We show theoretically and numerically that meta-analysis of summary results is statistically as efficient as joint analysis of individual participant data (provided that both analyses are performed properly under the same modeling assumptions). We illustrate this equivalence with case-control data from the Finland-United States Investigation of NIDDM Genetics (FUSION) study. Collating only summary results will increase the number and representativeness of available studies, simplify data collection and analysis, reduce resource utilization, and accelerate discovery. PMID:19847795

  17. Overview of Heat Addition and Efficiency Predictions for an Advanced Stirling Convertor

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.; Reid, Terry V.; Schifer, Nicholas A.; Briggs, Maxwell H.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot end and cold end temperatures, and specified electrical power output for a given net heat input. Microporous bulk insulation is used in the ground support test hardware to minimize the loss of thermal energy from the electric heat source to the environment. The insulation package is characterized before operation to predict how much heat will be absorbed by the convertor and how much will be lost to the environment during operation. In an effort to validate these predictions, numerous tasks have been performed, which provided a more accurate value for net heat input into the ASCs. This test and modeling effort included: (a) making thermophysical property measurements of test setup materials to provide inputs to the numerical models, (b) acquiring additional test data that was collected during convertor tests to provide numerical models with temperature profiles of the test setup via thermocouple and infrared measurements, (c) using multidimensional numerical models (computational fluid dynamics code) to predict net heat input of an operating convertor, and (d) using validation test hardware to provide direct comparison of numerical results and validate the multidimensional numerical models used to predict convertor net heat input. This effort produced high fidelity ASC net heat input predictions, which were successfully validated using

  18. Predicted versus measured photosynthetic water-use efficiency of crop stands under dynamically changing field environments.

    PubMed

    Xu, Liu-Kang; Hsiao, Theodore C

    2004-11-01

    Water-use efficiency (WUE) is critical in determining the adaptation and productivity of plants in water-limited areas, either under the present climate or future global change. Data on WUE are often highly variable and a unifying and quantitative approach is needed to analyse and predict WUE for different environments. Hsiao has already proposed a set of paradigm equations based on leaf gas exchange for this purpose, calculating WUE (ratio of assimilation to transpiration) relative to the WUE for a chosen reference situation. This study tests the validity and applicability of these equations to cotton and sweet corn stands with full canopies in the open field. Measured were evapotranspiration and downward flux of atmospheric CO2 into the canopy, soil CO2 efflux, canopy temperature, and CO2 and vapour pressure of the air surrounding the canopy. With the measured mean WUE and conditions at midday serving as the reference, WUE for other times was predicted from the air CO2 and water vapour data, intercellular water vapour pressure calculated from canopy temperature, and an assumed ratio of Ci/Ca based on leaf gas-exchange data. Provided that the stomatal response to humidity as it affected the Ci/Ca ratio was accounted for, the equations predicted the moment-by-moment changes in canopy WUE of cotton over daily cycles reasonably well, and also the variation in midday WUE from day-to-day over a 47 d period. The prediction for sweet corn was fairly good for most parts of the day except the early morning. Measurement uncertainties and possible causes of the differences between predicted and measured WUE are discussed. Overall, the results indicate that the equations may be suitable to simulate changes in WUE without upscaling, and also demonstrate clearly the importance of stomatal response to humidity in determining stand WUE in the field. PMID:15448179

  19. Efficient Coding Theory Predicts a Tilt Aftereffect from Viewing Untilted Patterns.

    PubMed

    May, Keith A; Zhaoping, Li

    2016-06-20

    The brain is bombarded with a continuous stream of sensory information, but biological limitations on the data-transmission rate require this information to be encoded very efficiently [1]. Li and Atick [2] proposed that the two eyes' signals are coded efficiently in the brain using mutually decorrelated binocular summation and differencing channels; when a channel is strongly stimulated by the visual input, such that sensory noise is negligible, the channel should undergo temporary desensitization (known as adaptation). To date, the evidence for this theory has been limited [3, 4], and the binocular differencing channel is missing from many models of binocular integration [5-10]. Li and Atick's theory makes the remarkable prediction that perceived direction of tilt (clockwise or counterclockwise) of a test pattern can be controlled by pre-exposing observers to visual adaptation patterns that are untilted or even have no orientation signal. Here, we confirm this prediction. Each test pattern consisted of different images presented to the two eyes such that the binocular summation and difference signals were tilted in opposite directions, to give ambiguous information about tilt; by selectively desensitizing one or other of the binocular channels using untilted or non-oriented binocular adaptation patterns, we controlled the perceived tilt of the test pattern. Our results provide compelling evidence that the brain contains binocular summation and differencing channels that adapt to the prevailing binocular statistics.

  20. Maximising the efficiency of clinical screening programmes: balancing predictive genetic testing with a right not to know

    PubMed Central

    Schuurman, Agnes G; van der Kolk, Dorina M; Verkerk, Marian A; Birnie, Erwin; Ranchor, Adelita V; Plantinga, Mirjam; van Langen, Irene M

    2015-01-01

    We explored the dilemma between patients' right not to know their genetic status and the efficient use of health-care resources in the form of clinical cancer screening programmes. Currently, in the Netherlands, 50% risk carriers of heritable cancer syndromes who choose not to know their genetic status have access to the same screening programmes as proven mutation carriers. This implies an inefficient use of health-care resources, because half of this group will not carry the familial mutation. At the moment, only a small number of patients are involved; however, the expanding possibilities for genetic risk profiling means this issue must be addressed because of potentially adverse societal and financial impact. The trade-off between patients' right not to know their genetic status and efficient use of health-care resources was discussed in six focus groups with health-care professionals and patients from three Dutch university hospitals. Professionals prefer patients to undergo a predictive DNA test as a prerequisite for entering cancer screening programmes. Professionals prioritise treating sick patients or proven mutation carriers over screening untested individuals. Participation in cancer screening programmes without prior DNA testing is, however, supported by most professionals, as testing is usually delayed and relatively few patients are involved at present. Reducing the number of 50% risk carriers undergoing screening is expected to be achieved by: offering more psychosocial support, explaining the iatrogenic risks of cancer screening, increasing out-of-pocket costs, and offering a less stringent screening programme for 50% risk carriers. PMID:25564039

  1. Individual differences in holistic processing predict the own-race advantage in recognition memory.

    PubMed

    Degutis, Joseph; Mercado, Rogelio J; Wilmer, Jeremy; Rosenblatt, Andrew

    2013-01-01

    Individuals are consistently better at recognizing own-race faces compared to other-race faces (other-race effect, ORE). One popular hypothesis is that this recognition memory ORE is caused by differential own- and other-race holistic processing, the simultaneous integration of part and configural face information into a coherent whole. Holistic processing may create a more rich, detailed memory representation of own-race faces compared to other-race faces. Despite several studies showing that own-race faces are processed more holistically than other-race faces, studies have yet to link the holistic processing ORE and the recognition memory ORE. In the current study, we sought to use a more valid method of analyzing individual differences in holistic processing by using regression to statistically remove the influence of the control condition (part trials in the part-whole task) from the condition of interest (whole trials in the part-whole task). We also employed regression to separately examine the two components of the ORE: own-race advantage (regressing other-race from own-race performance) and other-race decrement (regressing own-race from other-race performance). First, we demonstrated that own-race faces were processed more holistically than other-race faces, particularly the eye region. Notably, using regression, we showed a significant association between the own-race advantage in recognition memory and the own-race advantage in holistic processing and that these associations were weaker when examining the other-race decrement. We also demonstrated that performance on own- and other-race faces across all of our tasks was highly correlated, suggesting that the differences we found between own- and other-race faces are quantitative rather than qualitative. Together, this suggests that own- and other-race faces recruit largely similar mechanisms, that own-race faces more thoroughly engage holistic processing, and that this greater engagement of holistic

  2. Viscosity rather than quantity of dietary fibre predicts cholesterol-lowering effect in healthy individuals.

    PubMed

    Vuksan, Vladimir; Jenkins, Alexandra L; Rogovik, Alexander L; Fairgrieve, Christopher D; Jovanovski, Elena; Leiter, Lawrence A

    2011-11-01

    The well-documented lipid-lowering effects of fibre may be related to its viscosity, a phenomenon that has been understudied, especially when fibre is given against the background of a typical North American (NA) diet. In this three-arm experiment, we compared the lipid-lowering effect of low-viscosity wheat bran (WB), medium-viscosity psyllium (PSY) and a high-viscosity viscous fibre blend (VFB), as part of a fibre intervention aimed at increasing fibre intake to recommended levels within the context of a NA diet in apparently healthy individuals. Using a randomised cross-over design, twenty-three participants (twelve males and eleven females; age 35 (SD 12) years; LDL-cholesterol (C) 2.9 (SEM 0.6) mmol/l) consuming a typical NA diet received a standard, fibre-enriched cereal, where approximately one-third of the fibre was either a low-viscosity (570 centipoise (cP)) WB, medium-viscosity (14,300 cP) PSY or a high-viscosity (136,300 cP) novel VFB, for 3 weeks separated by washout periods of ≥ 2 weeks. There were no differences among the treatments in the amount of food consumed, total dietary fibre intake, reported physical activity and body weight. Final intake of the WB, PSY and VFB was 10.8, 9.0 and 5.1 g, respectively. Reduction in LDL-C was greater with the VFB compared with the medium-viscosity PSY (-12.6 (SEM 3.5) %, P = 0.002) and low-viscosity WB (-14.6 (SEM 4.2) %, P = 0.003). The magnitude of LDL-C reduction showed a positive association with fibre apparent viscosity (r - 0.41, P = 0.001). Despite the smaller quantity consumed, the high-viscosity fibre lowered LDL-C to a greater extent than lower-viscosity fibres. These data support the inclusion of high-viscosity fibre in the diet to reduce plasma lipids among apparently healthy individuals consuming a typical NA diet.

  3. Does Sense of Control Predict Depression Among Individuals After Psychiatric Hospital Discharge?

    PubMed

    Kim, Yoo Jung; Fusco, Rachel A

    2015-11-01

    Sense of control is known to be related to depression. Yet, few studies have examined the role of sense of control as related to depression for discharged psychiatric patients. In this study the longitudinal relationship between sense of control and depressive mood was examined using the MacArthur Violence Risk Assessment Study, a 6-wave, 1-year study of 948 ethnically diverse postdischarge psychiatric patients. Sense of control was decomposed into 2 components (i.e., a time-invariant as well as a time-varying component) and so as to examine which component of sense of control would more accurately explain this relationship. Results demonstrated that time-varying sense of control significantly predicted changes in depressive mood during the transition to community environment. Time-invariant sense of control, however, was not significantly related to changes in depressive mood. Findings of this study hold important implications for intervention practice with people before or after psychiatric discharge, including the need for incorporation of therapeutic and psychoeducational efforts that bolster sense of control.

  4. Brain activity in valuation regions while thinking about the future predicts individual discount rates.

    PubMed

    Cooper, Nicole; Kable, Joseph W; Kim, B Kyu; Zauberman, Gal

    2013-08-01

    People vary widely in how much they discount delayed rewards, yet little is known about the sources of these differences. Here we demonstrate that neural activity in ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) when human subjects are asked to merely think about the future--specifically, to judge the subjective length of future time intervals--predicts delay discounting. High discounters showed lower activity for longer time delays, while low discounters showed the opposite pattern. Our results demonstrate that the correlation between VMPFC and VS activity and discounting occurs even in the absence of choices about future rewards, and does not depend on a person explicitly evaluating future outcomes or judging their self-relevance. This suggests a link between discounting and basic processes involved in thinking about the future, such as temporal perception. Our results also suggest that reducing impatience requires not suppression of VMPFC and VS activity altogether, but rather modulation of how these regions respond to the present versus the future.

  5. Brain Activity in Valuation Regions while Thinking about the Future Predicts Individual Discount Rates

    PubMed Central

    Cooper, Nicole; Kim, B. Kyu; Zauberman, Gal

    2013-01-01

    People vary widely in how much they discount delayed rewards, yet little is known about the sources of these differences. Here we demonstrate that neural activity in ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) when human subjects are asked to merely think about the future—specifically, to judge the subjective length of future time intervals—predicts delay discounting. High discounters showed lower activity for longer time delays, while low discounters showed the opposite pattern. Our results demonstrate that the correlation between VMPFC and VS activity and discounting occurs even in the absence of choices about future rewards, and does not depend on a person explicitly evaluating future outcomes or judging their self-relevance. This suggests a link between discounting and basic processes involved in thinking about the future, such as temporal perception. Our results also suggest that reducing impatience requires not suppression of VMPFC and VS activity altogether, but rather modulation of how these regions respond to the present versus the future. PMID:23926268

  6. Predicting sex offender treatment entry among individuals convicted of sexual offense crimes.

    PubMed

    Jones, Nicole; Pelissier, Bernadette; Klein-Saffran, Jody

    2006-01-01

    This study examined what factors were predictive of who volunteers for sex offender treatment (self-selection) as well as who enters treatment after volunteering (administration selection). Research participants included 404 treatment volunteers and 387 nonvolunteers to treatment who were convicted of a sexual offense involving minors within the federal prison system. Maximum likelihood probit estimation procedures indicated that when compared with nonvolunteers, treatment volunteers were more likely to be recommended by a judge to receive treatment at the time of sentencing, had received prior treatment for sexually deviant behavior, reported higher levels of motivation to change their sexually deviant behavior, and had lower rates of a substance use disorder in the year prior to incarceration. Of those persons who initially volunteered, 62% were accepted and entered treatment, 16% were denied entry to treatment by program staff, and 22% refused treatment after being accepted to the waiting list. When compared with those who were accepted and entered treatment, motivation was the only predictor of being denied admission into treatment by program staff and for refusal of treatment once accepted. The findings emphasize the need to control for selection bias in treatment outcome studies and the importance of examining the role of motivation in treatment volunteerism and treatment entry for sexual offenders. PMID:16763760

  7. Brain activity in valuation regions while thinking about the future predicts individual discount rates.

    PubMed

    Cooper, Nicole; Kable, Joseph W; Kim, B Kyu; Zauberman, Gal

    2013-08-01

    People vary widely in how much they discount delayed rewards, yet little is known about the sources of these differences. Here we demonstrate that neural activity in ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) when human subjects are asked to merely think about the future--specifically, to judge the subjective length of future time intervals--predicts delay discounting. High discounters showed lower activity for longer time delays, while low discounters showed the opposite pattern. Our results demonstrate that the correlation between VMPFC and VS activity and discounting occurs even in the absence of choices about future rewards, and does not depend on a person explicitly evaluating future outcomes or judging their self-relevance. This suggests a link between discounting and basic processes involved in thinking about the future, such as temporal perception. Our results also suggest that reducing impatience requires not suppression of VMPFC and VS activity altogether, but rather modulation of how these regions respond to the present versus the future. PMID:23926268

  8. The Eye is Listening: Music-Induced Arousal and Individual Differences Predict Pupillary Responses.

    PubMed

    Gingras, Bruno; Marin, Manuela M; Puig-Waldmüller, Estela; Fitch, W T

    2015-01-01

    Pupillary responses are a well-known indicator of emotional arousal but have not yet been systematically investigated in response to music. Here, we measured pupillary dilations evoked by short musical excerpts normalized for intensity and selected for their stylistic uniformity. Thirty participants (15 females) provided subjective ratings of music-induced felt arousal, tension, pleasantness, and familiarity for 80 classical music excerpts. The pupillary responses evoked by these excerpts were measured in another thirty participants (15 females). We probed the role of listener-specific characteristics such as mood, stress reactivity, self-reported role of music in life, liking for the selected excerpts, as well as of subjective responses to music, in pupillary responses. Linear mixed model analyses showed that a greater role of music in life was associated with larger dilations, and that larger dilations were also predicted for excerpts rated as more arousing or tense. However, an interaction between arousal and liking for the excerpts suggested that pupillary responses were modulated less strongly by arousal when the excerpts were particularly liked. An analogous interaction was observed between tension and liking. Additionally, males exhibited larger dilations than females. Overall, these findings suggest a complex interplay between bottom-up and top-down influences on pupillary responses to music. PMID:26617511

  9. The Eye is Listening: Music-Induced Arousal and Individual Differences Predict Pupillary Responses

    PubMed Central

    Gingras, Bruno; Marin, Manuela M.; Puig-Waldmüller, Estela; Fitch, W. T.

    2015-01-01

    Pupillary responses are a well-known indicator of emotional arousal but have not yet been systematically investigated in response to music. Here, we measured pupillary dilations evoked by short musical excerpts normalized for intensity and selected for their stylistic uniformity. Thirty participants (15 females) provided subjective ratings of music-induced felt arousal, tension, pleasantness, and familiarity for 80 classical music excerpts. The pupillary responses evoked by these excerpts were measured in another thirty participants (15 females). We probed the role of listener-specific characteristics such as mood, stress reactivity, self-reported role of music in life, liking for the selected excerpts, as well as of subjective responses to music, in pupillary responses. Linear mixed model analyses showed that a greater role of music in life was associated with larger dilations, and that larger dilations were also predicted for excerpts rated as more arousing or tense. However, an interaction between arousal and liking for the excerpts suggested that pupillary responses were modulated less strongly by arousal when the excerpts were particularly liked. An analogous interaction was observed between tension and liking. Additionally, males exhibited larger dilations than females. Overall, these findings suggest a complex interplay between bottom-up and top-down influences on pupillary responses to music. PMID:26617511

  10. Individual differences in the habitual use of cognitive reappraisal predict the reward-related processing

    PubMed Central

    Sai, Liyang; Wang, Sisi; Ward, Anne; Ku, Yixuan; Sang, Biao

    2015-01-01

    Recent studies have shown that instructed cognitive reappraisal can regulate the neural processing of reward. However, it is still unclear whether the habitual use of cognitive reappraisal in everyday life is related to brain activity involved in reward processing. In the present study, participants’ neural responses to reward were measured using electroencephalography (EEG) recorded during a gambling task and their tendency to use cognitive reappraisal was assessed using the Emotion Regulation Questionnaire (ERQ). Event-related potential (ERP) results indicated that losses on the gambling task elicited greater negative reward-related feedback negativity (FN) than gains. The differential FN between losses and gains was significantly correlated with cognitive reappraisal scores across participants such that individuals with a higher tendency to use cognitive reappraisal showed stronger reward processing (i.e., amplified FN difference between losses and gains). This correlation remained significant after controlling for expressive suppression scores. However, expressive suppression per se was not correlated with FN differences. Taken together, these results suggest that the habitual use of cognitive reappraisal is associated with increased neural processing of reward. PMID:26388796

  11. Predicting Speech Intelligibility Decline in Amyotrophic Lateral Sclerosis Based on the Deterioration of Individual Speech Subsystems

    PubMed Central

    Yunusova, Yana; Wang, Jun; Zinman, Lorne; Pattee, Gary L.; Berry, James D.; Perry, Bridget; Green, Jordan R.

    2016-01-01

    Purpose To determine the mechanisms of speech intelligibility impairment due to neurologic impairments, intelligibility decline was modeled as a function of co-occurring changes in the articulatory, resonatory, phonatory, and respiratory subsystems. Method Sixty-six individuals diagnosed with amyotrophic lateral sclerosis (ALS) were studied longitudinally. The disease-related changes in articulatory, resonatory, phonatory, and respiratory subsystems were quantified using multiple instrumental measures, which were subjected to a principal component analysis and mixed effects models to derive a set of speech subsystem predictors. A stepwise approach was used to select the best set of subsystem predictors to model the overall decline in intelligibility. Results Intelligibility was modeled as a function of five predictors that corresponded to velocities of lip and jaw movements (articulatory), number of syllable repetitions in the alternating motion rate task (articulatory), nasal airflow (resonatory), maximum fundamental frequency (phonatory), and speech pauses (respiratory). The model accounted for 95.6% of the variance in intelligibility, among which the articulatory predictors showed the most substantial independent contribution (57.7%). Conclusion Articulatory impairments characterized by reduced velocities of lip and jaw movements and resonatory impairments characterized by increased nasal airflow served as the subsystem predictors of the longitudinal decline of speech intelligibility in ALS. Declines in maximum performance tasks such as the alternating motion rate preceded declines in intelligibility, thus serving as early predictors of bulbar dysfunction. Following the rapid decline in speech intelligibility, a precipitous decline in maximum performance tasks subsequently occurred. PMID:27148967

  12. Psychological Profiles in the Prediction of Leukocyte Telomere Length in Healthy Individuals

    PubMed Central

    Starnino, Louisia; Busque, Lambert; Tardif, Jean-Claude

    2016-01-01

    Background Shorter telomere length (TL) may signal premature cellular aging and increased risk for disease. While depression and psychosocial stress have been associated with shorter telomeres, other psychological risk factors for cardiovascular disease have received less attention. Purpose To evaluate the association between TL and psychological risk factors (symptoms of anxiety and depression, hostility and defensiveness traits) for heart disease, and to examine whether chronological age and sex moderate the associations observed. Methods 132 healthy men and women (Mage = 45.34 years) completed the Marlowe-Crowne Social Desirability Scale, the Beck Depression Inventory II, The Beck Anxiety Inventory and the Cook-Medley Hostility Scale. Relative TL was measured by quantitative polymerase chain reaction (PCR) of total genomic DNA samples. A series of hierarchical linear regressions were performed controlling for pertinent covariates. Results Shorter TL was observed among individuals high in defensiveness (β = -.221) and depressive symptoms (β = -.213), as well as in those with less hostility (β =.256) and anxiety (β =.220)(all Ps<.05). Psychological variables explained 19% of the variance over and above that explained by covariates (age, sex, exercise, alcohol consumption, systemic inflammation, and 24-hr mean arterial pressure). Age moderated the relation between TL and defensiveness (β =.179, p =.03). Sex did not influence any of the relations. Conclusions Telomere length is associated with psychological burden though the direction of effect differs depending on the psychological variables under study. Further research is needed to determine the reasons for and implications of these seemingly contradictory findings. PMID:27788238

  13. Supplementary motor area activations predict individual differences in temporal-change sensitivity and its illusory distortions.

    PubMed

    Herrmann, Björn; Henry, Molly J; Scharinger, Mathias; Obleser, Jonas

    2014-11-01

    Perception of time and temporal change is critical for human cognition. Yet, perception of temporal change is susceptible to contextual influences such as changes of a sound's pitch. Using functional magnetic resonance imaging (fMRI), the current study aimed to investigate perception of temporal rate change and pitch-induced illusory distortions. In a 6 × 6 design, human participants (N=19) listened to frequency-modulated sounds (~ 4 Hz) that varied over time in both modulation rate and pitch. Participants judged the direction of rate change ('speeding up' vs. 'slowing down'), while ignoring changes in pitch. Behaviorally, rate judgments were strongly biased by pitch changes: Participants perceived rate to slow down when pitch decreased and to speed up when pitch increased ('rate-change illusion'). The fMRI data revealed activation increases with increasing task difficulty in pre-SMA, left putamen, and right IFG/insula. Importantly, activation in pre-SMA was linked to the perceptual sensitivity to discriminate rate changes and, together with the left putamen, to relative reductions in susceptibility to pitch-induced illusory distortions. Right IFG/insula activations, however, only scaled with task difficulty. These data offer a distinction between regions whose activations scale with perceptual sensitivity to features of time (pre-SMA) and those that more generally support behaving in difficult listening conditions (IFG/insula). Hence, the data underscore that individual differences in time perception can be related to different patterns of neurofunctional activation.

  14. Oxygen Uptake Efficiency Plateau Best Predicts Early Death in Heart Failure

    PubMed Central

    Hansen, James E.; Stringer, William W.

    2012-01-01

    Background: The responses of oxygen uptake efficiency (ie, oxygen uptake/ventilation = V˙o2/V˙e) and its highest plateau (OUEP) during incremental cardiopulmonary exercise testing (CPET) in patients with chronic left heart failure (HF) have not been previously reported. We planned to test the hypothesis that OUEP during CPET is the best single predictor of early death in HF. Methods: We evaluated OUEP, slope of V˙o2 to log(V˙e) (oxygen uptake efficiency slope), oscillatory breathing, and all usual resting and CPET measurements in 508 patients with low-ejection-fraction (< 35%) HF. Each had further evaluations at other sites, including cardiac catheterization. Outcomes were 6-month all-reason mortality and morbidity (death or > 24 h cardiac hospitalization). Statistical analyses included area under curve of receiver operating characteristics, ORs, univariate and multivariate Cox regression, and Kaplan-Meier plots. Results: OUEP, which requires only moderate exercise, was often reduced in patients with HF. A low % predicted OUEP was the single best predictor of mortality (P < .0001), with an OR of 13.0 (P < .001). When combined with oscillatory breathing, the OR increased to 56.3, superior to all other resting or exercise parameters or combinations of parameters. Other statistical analyses and morbidity analysis confirmed those findings. Conclusions: OUEP is often reduced in patients with HF. Low % predicted OUEP (< 65% predicted) is the single best predictor of early death, better than any other CPET or other cardiovascular measurement. Paired with oscillatory breathing, it is even more powerful. PMID:22030802

  15. Cardiovascular Lifetime Risk Predicts Incidence of Coronary Calcification in Individuals With Low Short‐Term Risk: The Dallas Heart Study

    PubMed Central

    Paixao, Andre R. M.; Ayers, Colby R.; Rohatgi, Anand; Das, Sandeep R.; de Lemos, James A.; Khera, Amit; Lloyd‐Jones, Donald; Berry, Jarett D.

    2014-01-01

    Background The absence of coronary artery calcium (CAC) in middle age is associated with very low short‐term risk for coronary events. However, the long‐term implications of a CAC score of 0 are uncertain, particularly among individuals with high cardiovascular lifetime risk. We sought to characterize the association between predicted lifetime risk and incident CAC among individuals with low short‐term risk. Methods and Results We included 754 Dallas Heart Study participants with serial CAC scans (6.9 years apart) and both low short‐term risk and baseline CAC=0. Lifetime risk for cardiovascular disease was estimated according to risk factor burden. Among this group, 365 individuals (48.4%) were at low lifetime risk and 389 (51.6%) at high lifetime risk. High lifetime risk was associated with higher annualized CAC incidence (4.2% versus 2.7%; P < 0.001). Similarly, mean follow‐up CAC scores were higher among participants with high lifetime risk (7.8 versus 2.4 Agatston units). After adjustment for age, sex, and race, high lifetime risk remained independently associated with incident CAC (OR 1.60; 95% CI 1.12 to 2.27; P=0.01). When assessing risk factor burden at the follow‐up visit, 66.7% of CAC incidence observed in the low lifetime risk group occurred among individuals reclassified to a higher short‐ or long‐term risk category. Conclusion Among individuals with low short‐term risk and CAC scores of 0, high lifetime risk is associated with a higher incidence of CAC. These findings highlight the importance of lifetime risk even among individuals with very low short‐term risk. PMID:25424574

  16. An Efficient Molecular Dynamics Scheme for Predicting Dopant Implant Profiles in Semiconductors

    SciTech Connect

    Beardmore, K.M.; Gronbech-Jensen, N.

    1998-09-15

    The authors present a highly efficient molecular dynamics scheme for calculating the concentration profile of dopants implanted in group-IV alloy, and III-V zinc blende structure materials. The program incorporates methods for reducing computational overhead, plus a rare event algorithm to give statistical accuracy over several orders of magnitude change in the dopant concentration. The code uses a molecular dynamics (MD) model, instead of the binary collision approximation (BCA) used in implant simulators such as TRIM and Marlowe, to describe ion-target interactions. Atomic interactions are described by a combination of 'many-body' and screened Coulomb potentials. Inelastic energy loss is accounted for using a Firsov model, and electronic stopping is described by a Brandt-Kitagawa model which contains the single adjustable parameter for the entire scheme. Thus, the program is easily extensible to new ion-target combinations with the minimum of tuning, and is predictive over a wide range of implant energies and angles. The scheme is especially suited for calculating profiles due to low energy, large angle implants, and for situations where a predictive capability is required with the minimum of experimental validation. They give examples of using their code to calculate concentration profiles and 2D 'point response' profiles of dopants in crystalline silicon, silicon-germanium blends, and gallium-arsenide. They can predict the experimental profiles over five orders of magnitude for <100> and <110> channeling and for non-channeling implants at energies up to hundreds of keV.

  17. Efficient reversible watermarking based on adaptive prediction-error expansion and pixel selection.

    PubMed

    Li, Xiaolong; Yang, Bin; Zeng, Tieyong

    2011-12-01

    Prediction-error expansion (PEE) is an important technique of reversible watermarking which can embed large payloads into digital images with low distortion. In this paper, the PEE technique is further investigated and an efficient reversible watermarking scheme is proposed, by incorporating in PEE two new strategies, namely, adaptive embedding and pixel selection. Unlike conventional PEE which embeds data uniformly, we propose to adaptively embed 1 or 2 bits into expandable pixel according to the local complexity. This avoids expanding pixels with large prediction-errors, and thus, it reduces embedding impact by decreasing the maximum modification to pixel values. Meanwhile, adaptive PEE allows very large payload in a single embedding pass, and it improves the capacity limit of conventional PEE. We also propose to select pixels of smooth area for data embedding and leave rough pixels unchanged. In this way, compared with conventional PEE, a more sharply distributed prediction-error histogram is obtained and a better visual quality of watermarked image is observed. With these improvements, our method outperforms conventional PEE. Its superiority over other state-of-the-art methods is also demonstrated experimentally.

  18. Modeling dopaminergic and other processes involved in learning from reward prediction error: contributions from an individual differences perspective

    PubMed Central

    Pickering, Alan D.; Pesola, Francesca

    2014-01-01

    Phasic firing changes of midbrain dopamine neurons have been widely characterized as reflecting a reward prediction error (RPE). Major personality traits (e.g., extraversion) have been linked to inter-individual variations in dopaminergic neurotransmission. Consistent with these two claims, recent research (Smillie et al., 2011; Cooper et al., 2014) found that extraverts exhibited larger RPEs than introverts, as reflected in feedback related negativity (FRN) effects in EEG recordings. Using an established, biologically-localized RPE computational model, we successfully simulated dopaminergic cell firing changes which are thought to modulate the FRN. We introduced simulated individual differences into the model: parameters were systematically varied, with stable values for each simulated individual. We explored whether a model parameter might be responsible for the observed covariance between extraversion and the FRN changes in real data, and argued that a parameter is a plausible source of such covariance if parameter variance, across simulated individuals, correlated almost perfectly with the size of the simulated dopaminergic FRN modulation, and created as much variance as possible in this simulated output. Several model parameters met these criteria, while others did not. In particular, variations in the strength of connections carrying excitatory reward drive inputs to midbrain dopaminergic cells were considered plausible candidates, along with variations in a parameter which scales the effects of dopamine cell firing bursts on synaptic modification in ventral striatum. We suggest possible neurotransmitter mechanisms underpinning these model parameters. Finally, the limitations and possible extensions of our general approach are discussed. PMID:25324752

  19. Medial prefrontal-hippocampal connectivity during emotional memory encoding predicts individual differences in the loss of associative memory specificity.

    PubMed

    Berkers, Ruud M W J; Klumpers, Floris; Fernández, Guillén

    2016-10-01

    Emotionally charged items are often remembered better, whereas a paradoxical loss of specificity is found for associative emotional information (specific memory). The balance between specific and generalized emotional memories appears to show large individual differences, potentially related to differences in (the risk for) affective disorders that are characterized by 'overgeneralized' emotional memories. Here, we investigate the neural underpinnings of individual differences in emotional associative memory. A large group of healthy male participants were scanned while encoding associations of face-photographs and written occupational identities that were of either neutral ('driver') or negative ('murderer') valence. Subsequently, memory was tested by prompting participants to retrieve the occupational identities corresponding to each face. Whereas in both valence categories a similar amount of faces was labeled correctly with 'neutral' and 'negative' identities, (gist memory), specific associations were found to be less accurately remembered when the occupational identity was negative compared to neutral (specific memory). This pattern of results suggests reduced memory specificity for associations containing a negatively valenced component. The encoding of these negative associations was paired with a selective increase in medial prefrontal cortex activity and medial prefrontal-hippocampal connectivity. Individual differences in valence-specific neural connectivity were predictive of valence-specific reduction of memory specificity. The relationship between loss of emotional memory specificity and medial prefrontal-hippocampal connectivity is in line with the hypothesized role of a medial prefrontal-hippocampal circuit in regulating memory specificity, and warrants further investigations in individuals displaying 'overgeneralized' emotional memories. PMID:26868478

  20. Medial prefrontal-hippocampal connectivity during emotional memory encoding predicts individual differences in the loss of associative memory specificity.

    PubMed

    Berkers, Ruud M W J; Klumpers, Floris; Fernández, Guillén

    2016-10-01

    Emotionally charged items are often remembered better, whereas a paradoxical loss of specificity is found for associative emotional information (specific memory). The balance between specific and generalized emotional memories appears to show large individual differences, potentially related to differences in (the risk for) affective disorders that are characterized by 'overgeneralized' emotional memories. Here, we investigate the neural underpinnings of individual differences in emotional associative memory. A large group of healthy male participants were scanned while encoding associations of face-photographs and written occupational identities that were of either neutral ('driver') or negative ('murderer') valence. Subsequently, memory was tested by prompting participants to retrieve the occupational identities corresponding to each face. Whereas in both valence categories a similar amount of faces was labeled correctly with 'neutral' and 'negative' identities, (gist memory), specific associations were found to be less accurately remembered when the occupational identity was negative compared to neutral (specific memory). This pattern of results suggests reduced memory specificity for associations containing a negatively valenced component. The encoding of these negative associations was paired with a selective increase in medial prefrontal cortex activity and medial prefrontal-hippocampal connectivity. Individual differences in valence-specific neural connectivity were predictive of valence-specific reduction of memory specificity. The relationship between loss of emotional memory specificity and medial prefrontal-hippocampal connectivity is in line with the hypothesized role of a medial prefrontal-hippocampal circuit in regulating memory specificity, and warrants further investigations in individuals displaying 'overgeneralized' emotional memories.

  1. Validation of Normal Tissue Complication Probability Predictions in Individual Patient: Late Rectal Toxicity

    SciTech Connect

    Semenenko, Vladimir A.; Tarima, Sergey S.; Devisetty, Kiran; Pelizzari, Charles A.; Liauw, Stanley L.

    2013-03-15

    Purpose: To perform validation of risk predictions for late rectal toxicity (LRT) in prostate cancer obtained using a new approach to synthesize published normal tissue complication data. Methods and Materials: A published study survey was performed to identify the dose-response relationships for LRT derived from nonoverlapping patient populations. To avoid mixing models based on different symptoms, the emphasis was placed on rectal bleeding. The selected models were used to compute the risk estimates of grade 2+ and grade 3+ LRT for an independent validation cohort composed of 269 prostate cancer patients with known toxicity outcomes. Risk estimates from single studies were combined to produce consolidated risk estimates. An agreement between the actuarial toxicity incidence 3 years after radiation therapy completion and single-study or consolidated risk estimates was evaluated using the concordance correlation coefficient. Goodness of fit for the consolidated risk estimates was assessed using the Hosmer-Lemeshow test. Results: A total of 16 studies of grade 2+ and 5 studies of grade 3+ LRT met the inclusion criteria. The consolidated risk estimates of grade 2+ and 3+ LRT were constructed using 3 studies each. For grade 2+ LRT, the concordance correlation coefficient for the consolidated risk estimates was 0.537 compared with 0.431 for the best-fit single study. For grade 3+ LRT, the concordance correlation coefficient for the consolidated risk estimates was 0.477 compared with 0.448 for the best-fit single study. No evidence was found for a lack of fit for the consolidated risk estimates using the Hosmer-Lemeshow test (P=.531 and P=.397 for grade 2+ and 3+ LRT, respectively). Conclusions: In a large cohort of prostate cancer patients, selected sets of consolidated risk estimates were found to be more accurate predictors of LRT than risk estimates derived from any single study.

  2. Severe hypoxaemia can predict unfavourable clinical outcomes in individuals with pulmonary embolism aged over 40 years

    PubMed Central

    Souza, Caio Simoes; Resende, Fernanda Simoes Seabra; Rodrigues, Marcelo Palmeira

    2014-01-01

    INTRODUCTION Acute pulmonary embolism (APE) is an urgent clinical condition that can progress in a wide variety of ways. Therefore, we sought to develop an easy-to-apply algorithm, to be based on readily available clinical indicators, effective in predicting unfavourable outcomes. METHODS This was a retrospective cohort study based on systematically collected data in a database. The study included 102 patients with APE who were admitted to a tertiary care hospital. The following outcomes were defined as unfavourable shock, the need for mechanical ventilation, the use of thrombolytics, and death. Logistic regression analysis was used to explore variables significantly associated with outcome and to calculate post-test probabilities. RESULTS The prevalence of unfavourable outcomes was 25.5% (26 of the 102 patients with APE). The risk of an unfavourable outcome was reduced to 7.0% for patients with APE who were aged ≤ 40 years. In patients with APE who were aged > 40 years, the presence of hypoxaemia (i.e. peripheral oxygen saturation < 90%) alone increased the risk of an unfavourable outcome to 57.0%. A recent history of trauma and the presence of pre-existing lung or heart disease were significantly associated with unfavourable outcomes. The inclusion of those variables in the logistic regression model increased the post-test risk of an unfavourable outcome to 65.0%–86.0%. CONCLUSION Advanced age (i.e. > 40 years), the presence of hypoxaemia, a recent history of trauma and the presence of pre-existing lung or heart disease are risk factors for unfavourable outcome in patients with APE. PMID:25273933

  3. Individual differences in cortical face selectivity predict behavioral performance in face recognition

    PubMed Central

    Huang, Lijie; Song, Yiying; Li, Jingguang; Zhen, Zonglei; Yang, Zetian; Liu, Jia

    2014-01-01

    In functional magnetic resonance imaging studies, object selectivity is defined as a higher neural response to an object category than other object categories. Importantly, object selectivity is widely considered as a neural signature of a functionally-specialized area in processing its preferred object category in the human brain. However, the behavioral significance of the object selectivity remains unclear. In the present study, we used the individual differences approach to correlate participants' face selectivity in the face-selective regions with their behavioral performance in face recognition measured outside the scanner in a large sample of healthy adults. Face selectivity was defined as the z score of activation with the contrast of faces vs. non-face objects, and the face recognition ability was indexed as the normalized residual of the accuracy in recognizing previously-learned faces after regressing out that for non-face objects in an old/new memory task. We found that the participants with higher face selectivity in the fusiform face area (FFA) and the occipital face area (OFA), but not in the posterior part of the superior temporal sulcus (pSTS), possessed higher face recognition ability. Importantly, the association of face selectivity in the FFA and face recognition ability cannot be accounted for by FFA response to objects or behavioral performance in object recognition, suggesting that the association is domain-specific. Finally, the association is reliable, confirmed by the replication from another independent participant group. In sum, our finding provides empirical evidence on the validity of using object selectivity as a neural signature in defining object-selective regions in the human brain. PMID:25071513

  4. Allele Summation of Diabetes Risk Genes Predicts Impaired Glucose Tolerance in Female and Obese Individuals

    PubMed Central

    Hatziagelaki, Erifili; Ketterer, Caroline; Heni, Martin; Machicao, Fausto; Stefan, Norbert; Staiger, Harald; Häring, Hans-Ulrich; Fritsche, Andreas

    2012-01-01

    Introduction Single nucleotide polymorphisms (SNPs) in approximately 40 genes have been associated with an increased risk for type 2 diabetes (T2D) in genome-wide association studies. It is not known whether a similar genetic impact on the risk of prediabetes (impaired glucose tolerance [IGT] or impaired fasting glycemia [IFG]) exists. Methods In our cohort of 1442 non-diabetic subjects of European origin (normal glucose tolerance [NGT] n = 1046, isolated IFG n = 142, isolated IGT n = 140, IFG+IGT n = 114), an impact on glucose homeostasis has been shown for 9 SNPs in previous studies in this specific cohort. We analyzed these SNPs (within or in the vicinity of the genes TCF7L2, KCNJ11, HHEX, SLC30A8, WFS1, KCNQ1, MTNR1B, FTO, PPARG) for association with prediabetes. Results The genetic risk load was significantly associated with the risk for IGT (p = 0.0006) in a model including gender, age, BMI and insulin sensitivity. To further evaluate potential confounding effects, we stratified the population on gender, BMI and insulin sensitivity. The association of the risk score with IGT was present in female participants (p = 0.008), but not in male participants. The risk score was significantly associated with IGT (p = 0.008) in subjects with a body mass index higher than 30 kg/m2 but not in non-obese individuals. Furthermore, only in insulin resistant subjects a significant association between the genetic load and the risk for IGT (p = 0.01) was found. Discussion We found that T2D genetic risk alleles cause an increased risk for IGT. This effect was not present in male, lean and insulin sensitive subjects, suggesting a protective role of beneficial environmental factors on the genetic risk. PMID:22768041

  5. T cell subsets: an immunological biomarker to predict progression to clinical arthritis in ACPA-positive individuals

    PubMed Central

    Hunt, L; Hensor, E M; Nam, J; Burska, A N; Parmar, R; Emery, P; Ponchel, F

    2016-01-01

    Objectives Anticitrullinated protein antibody (ACPA)+ individuals with non-specific musculoskeletal symptoms are at risk of inflammatory arthritis (IA). This study aims to demonstrate the predictive value of T cell subset quantification for progression towards IA and compare it with previously identified clinical predictors of progression. Methods 103 ACPA+ individuals without clinical synovitis were observed 3-monthly for 12 months and then as clinically indicated. The end point was the development of IA. Naïve, regulatory T cells (Treg) and inflammation related cells (IRCs) were quantified by flow cytometry. Areas under the ROC curve (AUC) were calculated. Adjusted logistic regressions and Cox proportional hazards models for time to progression to IA were constructed. Results Compared with healthy controls (age adjusted where appropriate), ACPA+ individuals demonstrated reduced naïve (22.1% of subjects) and Treg (35.8%) frequencies and elevated IRC (29.5%). Of the 103 subjects, 48(46.6%) progressed. Individually, T cell subsets were weakly predictive (AUC between 0.63 and 0.66), although the presence of 2 T cell abnormalities had high specificity. Three models were compared: model-1 used T cell subsets only, model-2 used previously published clinical parameters, model-3 combined clinical data and T cell data. Model-3 performed the best (AUC 0.79 (95% CI 0.70 to 0.89)) compared with model-1 (0.75 (0.65 to 0.86)) and particularly with model-2 (0.62 (0.54 to 0.76)) demonstrating the added value of T cell subsets. Time to progression differed significantly between high-risk, moderate-risk and low-risk groups from model-3 (p=0.001, median 15.4 months, 25.8 months and 63.4 months, respectively). Conclusions T cell subset dysregulation in ACPA+ individuals predates the onset of IA, predicts the risk and faster progression to IA, with added value over previously published clinical predictors of progression. PMID:27613874

  6. Pre-SMA graymatter density predicts individual differences in action selection in the face of conscious and unconscious response conflict.

    PubMed

    van Gaal, Simon; Scholte, H Steven; Lamme, Victor A F; Fahrenfort, Johannes J; Ridderinkhof, K Richard

    2011-02-01

    The presupplementary motor area (pre-SMA) is considered key in contributing to voluntary action selection during response conflict. Here we test whether individual differences in the ability to select appropriate actions in the face of strong (conscious) and weak (virtually unconscious) distracting alternatives are related to individual variability in pre-SMA anatomy. To this end, we scanned 58 participants, who performed a masked priming task in which conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or virtually unconsciously (strongly masked primes), with structural magnetic resonance imaging. Voxel-based morphometry revealed that individual differences in pre-SMA gray-matter density are related to subjects' ability to voluntary select the correct action in the face of conflict, irrespective of the awareness level of conflict-inducing stimuli. These results link structural anatomy to individual differences in cognitive control ability, and provide support for the role of the pre-SMA in the selection of appropriate actions in situations of response conflict. Furthermore, these results suggest that flexible and voluntary behavior requires efficiently dealing with competing response tendencies, even those that are activated automatically and unconsciously. PMID:20175674

  7. Measures to Predict The Individual Variability of Corticospinal Responses Following Transcranial Direct Current Stimulation

    PubMed Central

    Nuzum, Nathan D.; Hendy, Ashlee M.; Russell, Aaron P.; Teo, Wei-Peng

    2016-01-01

    Individual responses to transcranial direct current stimulation (tDCS) are varied and therefore potentially limit its application. There is evidence that this variability is related to the contributions of Indirect waves (I-waves) recruited in the cortex. The latency of motor-evoked potentials (MEPs) can be measured through transcranial magnetic stimulation (TMS), allowing an individual’s responsiveness to tDCS to be determined. However, this single-pulse method requires several different orientations of the TMS coil, potentially affecting its reliability. Instead, we propose a paired-pulse TMS paradigm targeting I-waves as an alternative method. This method uses one orientation that reduces inter- and intra-trial variability. It was hypothesized that the paired-pulse method would correlate more highly to tDCS responses than the single-pulse method. In a randomized, double blinded, cross-over design, 30 healthy participants completed two sessions, receiving 20 min of either anodal (2 mA) or sham tDCS. TMS was used to quantify Short interval intracortical facilitation (SICF) at Inter stimulus intervals (ISIs) of 1.5, 3.5 and 4.5 ms. Latency was determined in the posterior-anterior (PA), anterior-posterior (AP) and latero-medial (LM) coil orientations. The relationship between latency, SICF measures and the change in suprathreshold MEP amplitude size following tDCS were determined with Pearson’s correlations. TMS measures, SICI and SICF were also used to determine responses to Anodal-tDCS (a-tDCS). Neither of the latency differences nor the SICF measures correlated to the change in MEP amplitude from pre-post tDCS (all P > 0.05). Overall, there was no significant response to tDCS in this cohort. This study highlights the need for testing the effects of various tDCS protocols on the different I-waves. Further research into SICF and whether it is a viable measure of I-wave facilitation is warranted. PMID:27766075

  8. Using Tests Designed to Measure Individual Sensorimotor Subsystem Perfomance to Predict Locomotor Adaptability

    NASA Technical Reports Server (NTRS)

    Peters, B. T.; Caldwell, E. E.; Batson, C. D.; Guined, J. R.; DeDios, Y. E.; Stepanyan, V.; Gadd, N. E.; Szecsy, D. L.; Mulavara, A. P.; Seidler, R. D.; Bloomberg, J. J.

    2014-01-01

    Astronauts experience sensorimotor disturbances during the initial exposure to microgravity and during the readapation phase following a return to a gravitational environment. These alterations may lead to disruption in the ability to perform mission critical functions during and after these gravitational transitions. Astronauts show significant inter-subject variation in adaptive capability following gravitational transitions. The way each individual's brain synthesizes the available visual, vestibular and somatosensory information is likely the basis for much of the variation. Identifying the presence of biases in each person's use of information available from these sensorimotor subsystems and relating it to their ability to adapt to a novel locomotor task will allow us to customize a training program designed to enhance sensorimotor adaptability. Eight tests are being used to measure sensorimotor subsystem performance. Three of these use measures of body sway to characterize balance during varying sensorimotor challenges. The effect of vision is assessed by repeating conditions with eyes open and eyes closed. Standing on foam, or on a support surface that pitches to maintain a constant ankle angle provide somatosensory challenges. Information from the vestibular system is isolated when vision is removed and the support surface is compromised, and it is challenged when the tasks are done while the head is in motion. The integration and dominance of visual information is assessed in three additional tests. The Rod & Frame Test measures the degree to which a subject's perception of the visual vertical is affected by the orientation of a tilted frame in the periphery. Locomotor visual dependence is determined by assessing how much an oscillating virtual visual world affects a treadmill-walking subject. In the third of the visual manipulation tests, subjects walk an obstacle course while wearing up-down reversing prisms. The two remaining tests include direct

  9. SNP development from RNA-seq data in a nonmodel fish: how many individuals are needed for accurate allele frequency prediction?

    PubMed

    Schunter, C; Garza, J C; Macpherson, E; Pascual, M

    2014-01-01

    Single nucleotide polymorphisms (SNPs) are rapidly becoming the marker of choice in population genetics due to a variety of advantages relative to other markers, including higher genomic density, data quality, reproducibility and genotyping efficiency, as well as ease of portability between laboratories. Advances in sequencing technology and methodologies to reduce genomic representation have made the isolation of SNPs feasible for nonmodel organisms. RNA-seq is one such technique for the discovery of SNPs and development of markers for large-scale genotyping. Here, we report the development of 192 validated SNP markers for parentage analysis in Tripterygion delaisi (the black-faced blenny), a small rocky-shore fish from the Mediterranean Sea. RNA-seq data for 15 individual samples were used for SNP discovery by applying a series of selection criteria. Genotypes were then collected from 1599 individuals from the same population with the resulting loci. Differences in heterozygosity and allele frequencies were found between the two data sets. Heterozygosity was lower, on average, in the population sample, and the mean difference between the frequencies of particular alleles in the two data sets was 0.135 ± 0.100. We used bootstrap resampling of the sequence data to predict appropriate sample sizes for SNP discovery. As cDNA library production is time-consuming and expensive, we suggest that using seven individuals for RNA sequencing reduces the probability of discarding highly informative SNP loci, due to lack of observed polymorphism, whereas use of more than 12 samples does not considerably improve prediction of true allele frequencies.

  10. Predicting Radiation Pneumonitis After Chemoradiation Therapy for Lung Cancer: An International Individual Patient Data Meta-analysis

    SciTech Connect

    Palma, David A.; Senan, Suresh; Tsujino, Kayoko; Barriger, Robert B.; Rengan, Ramesh; Moreno, Marta; Bradley, Jeffrey D.; Kim, Tae Hyun; Ramella, Sara; Marks, Lawrence B.; De Petris, Luigi; Stitt, Larry; Rodrigues, George

    2013-02-01

    Background: Radiation pneumonitis is a dose-limiting toxicity for patients undergoing concurrent chemoradiation therapy (CCRT) for non-small cell lung cancer (NSCLC). We performed an individual patient data meta-analysis to determine factors predictive of clinically significant pneumonitis. Methods and Materials: After a systematic review of the literature, data were obtained on 836 patients who underwent CCRT in Europe, North America, and Asia. Patients were randomly divided into training and validation sets (two-thirds vs one-third of patients). Factors predictive of symptomatic pneumonitis (grade {>=}2 by 1 of several scoring systems) or fatal pneumonitis were evaluated using logistic regression. Recursive partitioning analysis (RPA) was used to define risk groups. Results: The median radiation therapy dose was 60 Gy, and the median follow-up time was 2.3 years. Most patients received concurrent cisplatin/etoposide (38%) or carboplatin/paclitaxel (26%). The overall rate of symptomatic pneumonitis was 29.8% (n=249), with fatal pneumonitis in 1.9% (n=16). In the training set, factors predictive of symptomatic pneumonitis were lung volume receiving {>=}20 Gy (V{sub 20}) (odds ratio [OR] 1.03 per 1% increase, P=.008), and carboplatin/paclitaxel chemotherapy (OR 3.33, P<.001), with a trend for age (OR 1.24 per decade, P=.09); the model remained predictive in the validation set with good discrimination in both datasets (c-statistic >0.65). On RPA, the highest risk of pneumonitis (>50%) was in patients >65 years of age receiving carboplatin/paclitaxel. Predictors of fatal pneumonitis were daily dose >2 Gy, V{sub 20}, and lower-lobe tumor location. Conclusions: Several treatment-related risk factors predict the development of symptomatic pneumonitis, and elderly patients who undergo CCRT with carboplatin-paclitaxel chemotherapy are at highest risk. Fatal pneumonitis, although uncommon, is related to dosimetric factors and tumor location.

  11. Behavior and neuroimaging at baseline predict individual response to combined mathematical and working memory training in children.

    PubMed

    Nemmi, Federico; Helander, Elin; Helenius, Ola; Almeida, Rita; Hassler, Martin; Räsänen, Pekka; Klingberg, Torkel

    2016-08-01

    Mathematical performance is highly correlated with several general cognitive abilities, including working memory (WM) capacity. Here we investigated the effect of numerical training using a number-line (NLT), WM training (WMT), or the combination of the two on a composite score of mathematical ability. The aim was to investigate if the combination contributed to the outcome, and determine if baseline performance or neuroimaging predict the magnitude of improvement. We randomly assigned 308, 6-year-old children to WMT, NLT, WMT+NLT or a control intervention. Overall, there was a significant effect of NLT but not WMT. The WMT+NLT was the only group that improved significantly more than the controls, although the interaction NLTxWM was non-significant. Higher WM and maths performance predicted larger benefits for WMT and NLT, respectively. Neuroimaging at baseline also contributed significant information about training gain. Different individuals showed as much as a three-fold difference in their responses to the same intervention. These results show that the impact of an intervention is highly dependent on individual characteristics of the child. If differences in responses could be used to optimize the intervention for each child, future interventions could be substantially more effective. PMID:27399278

  12. Do PTSD Symptoms and Course Predict Continued Substance Use for Homeless Individuals in Contingency Management for Cocaine Dependence?

    PubMed Central

    Burns, Michelle Nicole; Lehman, Kenneth A.; Milby, Jesse B.; Wallace, Dennis; Schumacher, Joseph E.

    2010-01-01

    Homeless individuals (n = 187) entering contingency management (CM) for cocaine dependence were assessed for PTSD diagnosis, and a subset of 102 participants reporting traumatic exposure also periodically completed a self-report measure of PTSD symptoms. Patients with PTSD in full remission at 6 months (end of active treatment) and 12 months (end of aftercare) used substances much less frequently during aftercare than those with no PTSD diagnosis. Those whose PTSD diagnosis improved to full remission status during active treatment, and remained in full remission at 12 months, also had superior substance use outcomes. Severity of PTSD symptoms at 6 months, but not baseline or 2 months, was associated with substance use across treatment phases. Substance use during aftercare, however, was better predicted by changes in PTSD symptom severity. Patients whose PTSD symptoms improved more during active treatment fared better during aftercare than those with less improvement. Findings suggest homeless individuals with comorbid PTSD entering CM for cocaine dependence are not necessarily at increased risk for substance use compared to those without the comorbidity. However, course of PTSD does predict substance use, with the potential for CM to be unusually effective for those who respond with substantial, lasting improvements in PTSD. PMID:20363465

  13. Predicting individual differences in decision-making process from signature movement styles: an illustrative study of leaders

    PubMed Central

    Connors, Brenda L.; Rende, Richard; Colton, Timothy J.

    2013-01-01

    There has been a surge of interest in examining the utility of methods for capturing individual differences in decision-making style. We illustrate the potential offered by Movement Pattern Analysis (MPA), an observational methodology that has been used in business and by the US Department of Defense to record body movements that provide predictive insight into individual differences in decision-making motivations and actions. Twelve military officers participated in an intensive 2-h interview that permitted detailed and fine-grained observation and coding of signature movements by trained practitioners using MPA. Three months later, these subjects completed four hypothetical decision-making tasks in which the amount of information sought out before coming to a decision, as well as the time spent on the tasks, were under the partial control of the subject. A composite MPA indicator of how a person allocates decision-making actions and motivations to balance both Assertion (exertion of tangible movement effort on the environment to make something occur) and Perspective (through movements that support shaping in the body to perceive and create a suitable viewpoint for action) was highly correlated with the total number of information draws and total response time—individuals high on Assertion reached for less information and had faster response times than those high on Perspective. Discussion focuses on the utility of using movement-based observational measures to capture individual differences in decision-making style and the implications for application in applied settings geared toward investigations of experienced leaders and world statesmen where individuality rules the day. PMID:24069012

  14. Predicting Input Impedance and Efficiency of Graphene Reconfigurable Dipoles Using a Simple Circuit Model

    NASA Astrophysics Data System (ADS)

    Tamagnone, Michele; Perruisseau-Carrier, Julien

    An analytical circuit model able to predict the input impedance of reconfigurable graphene plasmonic dipoles is presented. A suitable definition of plasmonic characteristic impedance, employing natural currents, is used to for consistent modeling of the antenna-load connection in the circuit. In its purely analytical form, the model shows good agreement with full-wave simulations, and explains the remarkable tuning properties of graphene antennas. Furthermore, using a single full-wave simulation and scaling laws, additional parasitic elements can be determined for a vast parametric space, leading to very accurate modeling. Finally, we also show that the modeling approach allows fair estimation of radiation efficiency as well. The approach also applies to thin plasmonic antennas realized using noble metals or semiconductors.

  15. LTR_FINDER: an efficient tool for the prediction of full-length LTR retrotransposons.

    PubMed

    Xu, Zhao; Wang, Hao

    2007-07-01

    Long terminal repeat retrotransposons (LTR elements) are ubiquitous eukaryotic transposable elements. They play important roles in the evolution of genes and genomes. Ever-growing amount of genomic sequences of many organisms present a great challenge to fast identifying them. That is the first and indispensable step to study their structure, distribution, functions and other biological impacts. However, until today, tools for efficient LTR retrotransposon discovery are very limited. Thus, we developed LTR_FINDER web server. Given DNA sequences, it predicts locations and structure of full-length LTR retrotransposons accurately by considering common structural features. LTR_FINDER is a system capable of scanning large-scale sequences rapidly and the first web server for ab initio LTR retrotransposon finding. We illustrate its usage and performance on the genome of Saccharomyces cerevisiae. The web server is freely accessible at http://tlife.fudan.edu.cn/ltr_finder/.

  16. Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

    USGS Publications Warehouse

    Miller, David A.; Vleck, Carol M.; Otis, David L.

    2009-01-01

    Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10–15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

  17. Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

    USGS Publications Warehouse

    Miller, David A.; Vleck, Carol M.; Otis, David L.

    2009-01-01

    Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10–15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

  18. Predicting Esophagitis After Chemoradiation Therapy for Non-Small Cell Lung Cancer: An Individual Patient Data Meta-Analysis

    SciTech Connect

    Palma, David A.; Senan, Suresh; Oberije, Cary; Belderbos, Jose; Dios, Núria Rodríguez de; Bradley, Jeffrey D.; Barriger, R. Bryan; Moreno-Jiménez, Marta; Kim, Tae Hyun; Ramella, Sara; Everitt, Sarah; Rengan, Ramesh; Marks, Lawrence B.; De Ruyck, Kim; and others

    2013-11-15

    Purpose: Concurrent chemoradiation therapy (CCRT) improves survival compared with sequential treatment for locally advanced non-small cell lung cancer, but it increases toxicity, particularly radiation esophagitis (RE). Validated predictors of RE for clinical use are lacking. We performed an individual-patient-data meta-analysis to determine factors predictive of clinically significant RE. Methods and Materials: After a systematic review of the literature, data were obtained on 1082 patients who underwent CCRT, including patients from Europe, North America, Asia, and Australia. Patients were randomly divided into training and validation sets (2/3 vs 1/3 of patients). Factors predictive of RE (grade ≥2 and grade ≥3) were assessed using logistic modeling, with the concordance statistic (c statistic) used to evaluate the performance of each model. Results: The median radiation therapy dose delivered was 65 Gy, and the median follow-up time was 2.1 years. Most patients (91%) received platinum-containing CCRT regimens. The development of RE was common, scored as grade 2 in 348 patients (32.2%), grade 3 in 185 (17.1%), and grade 4 in 10 (0.9%). There were no RE-related deaths. On univariable analysis using the training set, several baseline factors were statistically predictive of RE (P<.05), but only dosimetric factors had good discrimination scores (c > .60). On multivariable analysis, the esophageal volume receiving ≥60 Gy (V60) alone emerged as the best predictor of grade ≥2 and grade ≥3 RE, with good calibration and discrimination. Recursive partitioning identified 3 risk groups: low (V60 <0.07%), intermediate (V60 0.07% to 16.99%), and high (V60 ≥17%). With use of the validation set, the predictive model performed inferiorly for the grade ≥2 endpoint (c = .58) but performed well for the grade ≥3 endpoint (c = .66). Conclusions: Clinically significant RE is common, but life-threatening complications occur in <1% of patients. Although several factors

  19. Efficiency of diagnostic model to predict recurrent suicidal incidents in diverse world communities

    PubMed Central

    Vatsalya, Vatsalya; Chandras, Kan; Srivastava, Shweta; Karch, Robert

    2014-01-01

    Suicidal attempts have a very significant effect on the society, and they also reflect on the efforts of the supporting health care and counseling facilities; and the mental health professionals involved. The impact of suicide is further magnified by the needs of persons who attempt suicide multiple times, requiring emergency health care and rehabilitation. Preventing such activities becomes a major task for the support providing agencies as soon as patient with such tendencies are identified. There are repetitive traits that can be observed during the entire therapeutic program among the high-risk group individuals, who are susceptible to this kind of activity and such traits indicate for specific profiling. The aim of the instrument is to prevent the occurrence of the repetitive suicidal attempts of the patients in various world regions, which may have significantly higher and concerning suicide rates. This profile has been constructed on the various parameters recognized in the statistical analysis of the patient population, which have been identified or can be under treatment for their suicidal behavior. This instrument is developed to predict the probability of population segments who may attempt suicide and repetitively, by matching the parameters of the profile with that of the patient pool. Building a profile for the purpose of predicting behavior of this kind can strengthen the intervention strategies more comprehensively and reduce such incidents and health care requirements and expenses. PMID:25237407

  20. Development of effluent removal prediction model efficiency in septic sludge treatment plant through clonal selection algorithm.

    PubMed

    Ting, Sie Chun; Ismail, A R; Malek, M A

    2013-11-15

    This study aims at developing a novel effluent removal management tool for septic sludge treatment plants (SSTP) using a clonal selection algorithm (CSA). The proposed CSA articulates the idea of utilizing an artificial immune system (AIS) to identify the behaviour of the SSTP, that is, using a sequence batch reactor (SBR) technology for treatment processes. The novelty of this study is the development of a predictive SSTP model for effluent discharge adopting the human immune system. Septic sludge from the individual septic tanks and package plants will be desuldged and treated in SSTP before discharging the wastewater into a waterway. The Borneo Island of Sarawak is selected as the case study. Currently, there are only two SSTPs in Sarawak, namely the Matang SSTP and the Sibu SSTP, and they are both using SBR technology. Monthly effluent discharges from 2007 to 2011 in the Matang SSTP are used in this study. Cross-validation is performed using data from the Sibu SSTP from April 2011 to July 2012. Both chemical oxygen demand (COD) and total suspended solids (TSS) in the effluent were analysed in this study. The model was validated and tested before forecasting the future effluent performance. The CSA-based SSTP model was simulated using MATLAB 7.10. The root mean square error (RMSE), mean absolute percentage error (MAPE), and correction coefficient (R) were used as performance indexes. In this study, it was found that the proposed prediction model was successful up to 84 months for the COD and 109 months for the TSS. In conclusion, the proposed CSA-based SSTP prediction model is indeed beneficial as an engineering tool to forecast the long-run performance of the SSTP and in turn, prevents infringement of future environmental balance in other towns in Sarawak.

  1. In Search of a Time Efficient Approach to Crack and Delamination Growth Predictions in Composites

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald; Carvalho, Nelson

    2016-01-01

    Analysis benchmarking was used to assess the accuracy and time efficiency of algorithms suitable for automated delamination growth analysis. First, the Floating Node Method (FNM) was introduced and its combination with a simple exponential growth law (Paris Law) and Virtual Crack Closure technique (VCCT) was discussed. Implementation of the method into a user element (UEL) in Abaqus/Standard(Registered TradeMark) was also presented. For the assessment of growth prediction capabilities, an existing benchmark case based on the Double Cantilever Beam (DCB) specimen was briefly summarized. Additionally, the development of new benchmark cases based on the Mixed-Mode Bending (MMB) specimen to assess the growth prediction capabilities under mixed-mode I/II conditions was discussed in detail. A comparison was presented, in which the benchmark cases were used to assess the existing low-cycle fatigue analysis tool in Abaqus/Standard(Registered TradeMark) in comparison to the FNM-VCCT fatigue growth analysis implementation. The low-cycle fatigue analysis tool in Abaqus/Standard(Registered TradeMark) was able to yield results that were in good agreement with the DCB benchmark example. Results for the MMB benchmark cases, however, only captured the trend correctly. The user element (FNM-VCCT) always yielded results that were in excellent agreement with all benchmark cases, at a fraction of the analysis time. The ability to assess the implementation of two methods in one finite element code illustrated the value of establishing benchmark solutions.

  2. Fast intra-prediction algorithms for high efficiency video coding standard

    NASA Astrophysics Data System (ADS)

    Kibeya, Hassan; Belghith, Fatma; Ben Ayed, Mohammed Ali; Masmoudi, Nouri

    2016-01-01

    High efficiency video coding (HEVC) is the latest video compression standard that provides significant performance improvement on the compression ratio compared to all existing video coding standards. The intra-prediction procedure plays an important role in the HEVC encoder, and it is being achieved by providing up to 35 intra-modes with a larger coding unit requiring a high computational complexity that needs to be alleviated. Toward this end, the paper proposes two fast intra-mode decision algorithms that exploit the features of video sequences. First, an early detection of zero transform and quantified coefficients method is applied to generate threshold values employed for early termination of the intra-decision process and hence accelerates the encoding procedure. Another fast intra-mode decision algorithm is elaborated that relies on a refinement technique. Based on statistical analyses of frequently chosen modes, only a small part of the candidate modes is chosen for intra-prediction process, which reduces the complexity of the intra-encoding procedure. The performance of the proposed algorithms is verified through comparative analysis of encoding time, visual image quality, and compression ratio. Compared to HM 10.0, the encoding time reduction can reach 69% with only a slight degradation of image quality and compression ratio.

  3. Single-Cell Protein Profiling of Wastewater Enterobacterial Communities Predicts Disinfection Efficiency

    PubMed Central

    Ponniah, Gomathinayagam; Chen, Han; Michielutti, Ronda; Salonen, Nancy; Blum, Paul

    2003-01-01

    The efficiency of enterobacterial disinfection is dependent largely on enterobacterial community physiology. However, the relationship between enterobacterial community physiology and wastewater processing is unclear. The purpose of this study was to investigate this relationship. The influence of wastewater treatment processes on enterobacterial community physiology was examined at the single-cell level by using culture-independent methods. Intracellular concentrations of two conserved proteins, the growth-related protein Fis and the stationary-phase protein Dps, were analyzed by epifluoresence microscopy of uncultivated cells by using enterobacterial group-specific polyclonal fluorochrome-coupled antibodies. Enterobacterial single-cell community protein profiles were distinct for different types of biological treatment. The differences were not apparent when bulk methods of protein analysis were used. Trickling filter wastewater yielded Fis-enriched communities compared to the communities in submerged aeration basin wastewater. Community differences in Fis and Dps contents were used to predict disinfection efficiency. Disinfection of community samples by heat exposure combined with cultivation in selective media confirmed that enterobacterial communities exhibited significant differences in sensitivity to disinfection. These findings provide strategies that can be used to increase treatment plant performance, reduce the enterobacterial content in municipal wastewater, and minimize the release of disinfection by-products into receiving water. PMID:12839804

  4. Energy-Efficient Control with Harvesting Predictions for Solar-Powered Wireless Sensor Networks.

    PubMed

    Zou, Tengyue; Lin, Shouying; Feng, Qijie; Chen, Yanlian

    2016-01-04

    Wireless sensor networks equipped with rechargeable batteries are useful for outdoor environmental monitoring. However, the severe energy constraints of the sensor nodes present major challenges for long-term applications. To achieve sustainability, solar cells can be used to acquire energy from the environment. Unfortunately, the energy supplied by the harvesting system is generally intermittent and considerably influenced by the weather. To improve the energy efficiency and extend the lifetime of the networks, we propose algorithms for harvested energy prediction using environmental shadow detection. Thus, the sensor nodes can adjust their scheduling plans accordingly to best suit their energy production and residual battery levels. Furthermore, we introduce clustering and routing selection methods to optimize the data transmission, and a Bayesian network is used for warning notifications of bottlenecks along the path. The entire system is implemented on a real-time Texas Instruments CC2530 embedded platform, and the experimental results indicate that these mechanisms sustain the networks' activities in an uninterrupted and efficient manner.

  5. Efficient prediction of terahertz quantum cascade laser dynamics from steady-state simulations

    SciTech Connect

    Agnew, G.; Lim, Y. L.; Nikolić, M.; Rakić, A. D.; Grier, A.; Valavanis, A.; Cooper, J.; Dean, P.; Khanna, S. P.; Lachab, M.; Linfield, E. H.; Davies, A. G.; Ikonić, Z.; Indjin, D.; Taimre, T.; Harrison, P.

    2015-04-20

    Terahertz-frequency quantum cascade lasers (THz QCLs) based on bound-to-continuum active regions are difficult to model owing to their large number of quantum states. We present a computationally efficient reduced rate equation (RE) model that reproduces the experimentally observed variation of THz power with respect to drive current and heat-sink temperature. We also present dynamic (time-domain) simulations under a range of drive currents and predict an increase in modulation bandwidth as the current approaches the peak of the light–current curve, as observed experimentally in mid-infrared QCLs. We account for temperature and bias dependence of the carrier lifetimes, gain, and injection efficiency, calculated from a full rate equation model. The temperature dependence of the simulated threshold current, emitted power, and cut-off current are thus all reproduced accurately with only one fitting parameter, the interface roughness, in the full REs. We propose that the model could therefore be used for rapid dynamical simulation of QCL designs.

  6. Energy-Efficient Control with Harvesting Predictions for Solar-Powered Wireless Sensor Networks

    PubMed Central

    Zou, Tengyue; Lin, Shouying; Feng, Qijie; Chen, Yanlian

    2016-01-01

    Wireless sensor networks equipped with rechargeable batteries are useful for outdoor environmental monitoring. However, the severe energy constraints of the sensor nodes present major challenges for long-term applications. To achieve sustainability, solar cells can be used to acquire energy from the environment. Unfortunately, the energy supplied by the harvesting system is generally intermittent and considerably influenced by the weather. To improve the energy efficiency and extend the lifetime of the networks, we propose algorithms for harvested energy prediction using environmental shadow detection. Thus, the sensor nodes can adjust their scheduling plans accordingly to best suit their energy production and residual battery levels. Furthermore, we introduce clustering and routing selection methods to optimize the data transmission, and a Bayesian network is used for warning notifications of bottlenecks along the path. The entire system is implemented on a real-time Texas Instruments CC2530 embedded platform, and the experimental results indicate that these mechanisms sustain the networks’ activities in an uninterrupted and efficient manner. PMID:26742042

  7. [The use of information processes indices for prediction of sympathectomy efficiency in complex regional pain syndrome].

    PubMed

    Kuropatkin, A I

    2010-01-01

    Key significance of information processes for ensuring optimal sanogenesis was shown by wavelet-analysis of skin microvascular blood flow oscillations at 64 patients with complex regional pain syndrome after sympathectomy Early reorganization of information in trophotropic direction at the level of microvascular tissue systems, its predomination and conservation all along the microvascular networks facilitate optimal realization of adaptive reactions and, as a result, are conductive to maximum treatment efficiency. In these cases complete elimination of disease and achievement of excellent treatment results were possible. Maximum treatment efficiency could not be reached without the above-mentioned information changing. On the contrary predomination and conservation of ergotropic information at the early periods after surgery were unfavourable to prediction of clinical results of sympathectomy Tissue desympathisation is not required to formation of information trophotropic purposefulness in microvascular networks; it is enough to achieve certain threshold of sympathetic activity decrease. The results of this work may be useful for investigation of physiological mechanisms of information treatment technologies (homeopathy etc.).

  8. Efficient estimation and prediction for the Bayesian binary spatial model with flexible link functions.

    PubMed

    Roy, Vivekananda; Evangelou, Evangelos; Zhu, Zhengyuan

    2016-03-01

    Spatial generalized linear mixed models (SGLMMs) are popular models for spatial data with a non-Gaussian response. Binomial SGLMMs with logit or probit link functions are often used to model spatially dependent binomial random variables. It is known that for independent binomial data, the robit regression model provides a more robust (against extreme observations) alternative to the more popular logistic and probit models. In this article, we introduce a Bayesian spatial robit model for spatially dependent binomial data. Since constructing a meaningful prior on the link function parameter as well as the spatial correlation parameters in SGLMMs is difficult, we propose an empirical Bayes (EB) approach for the estimation of these parameters as well as for the prediction of the random effects. The EB methodology is implemented by efficient importance sampling methods based on Markov chain Monte Carlo (MCMC) algorithms. Our simulation study shows that the robit model is robust against model misspecification, and our EB method results in estimates with less bias than full Bayesian (FB) analysis. The methodology is applied to a Celastrus Orbiculatus data, and a Rhizoctonia root data. For the former, which is known to contain outlying observations, the robit model is shown to do better for predicting the spatial distribution of an invasive species. For the latter, our approach is doing as well as the classical models for predicting the disease severity for a root disease, as the probit link is shown to be appropriate. Though this article is written for Binomial SGLMMs for brevity, the EB methodology is more general and can be applied to other types of SGLMMs. In the accompanying R package geoBayes, implementations for other SGLMMs such as Poisson and Gamma SGLMMs are provided. PMID:26331903

  9. Efficient estimation and prediction for the Bayesian binary spatial model with flexible link functions.

    PubMed

    Roy, Vivekananda; Evangelou, Evangelos; Zhu, Zhengyuan

    2016-03-01

    Spatial generalized linear mixed models (SGLMMs) are popular models for spatial data with a non-Gaussian response. Binomial SGLMMs with logit or probit link functions are often used to model spatially dependent binomial random variables. It is known that for independent binomial data, the robit regression model provides a more robust (against extreme observations) alternative to the more popular logistic and probit models. In this article, we introduce a Bayesian spatial robit model for spatially dependent binomial data. Since constructing a meaningful prior on the link function parameter as well as the spatial correlation parameters in SGLMMs is difficult, we propose an empirical Bayes (EB) approach for the estimation of these parameters as well as for the prediction of the random effects. The EB methodology is implemented by efficient importance sampling methods based on Markov chain Monte Carlo (MCMC) algorithms. Our simulation study shows that the robit model is robust against model misspecification, and our EB method results in estimates with less bias than full Bayesian (FB) analysis. The methodology is applied to a Celastrus Orbiculatus data, and a Rhizoctonia root data. For the former, which is known to contain outlying observations, the robit model is shown to do better for predicting the spatial distribution of an invasive species. For the latter, our approach is doing as well as the classical models for predicting the disease severity for a root disease, as the probit link is shown to be appropriate. Though this article is written for Binomial SGLMMs for brevity, the EB methodology is more general and can be applied to other types of SGLMMs. In the accompanying R package geoBayes, implementations for other SGLMMs such as Poisson and Gamma SGLMMs are provided.

  10. A Method for Efficient Transmittance Spectrum Prediction of Transparent Composite Electrodes

    NASA Astrophysics Data System (ADS)

    Zhao, Zhao; Dhar, A.; Alford, T. L.

    2015-07-01

    The interest in indium-free transparent composite electrode (TCE), a thin metal layer embedded between two transparent metal oxide (TMO) layers resulting in TMO/metal/TMO composite structure, has grown recently with the advent of their high figures of merit and its potential application in photovoltaic applications. However, most of the work to date has focused on experimentally producing the best optically transmitting TCE. To better design TCEs and minimize experimental work, it would be useful to develop a model that predicts the optical transmission. In the current work, the transfer-matrix method is employed to calculate the transmittance spectrum of TCE. To validate this approach, the transmittance spectra of TiO2/Au/TiO2 and TiO2/Ag/TiO2 multilayer thin-film TCEs are calculated with use of extracted material parameters. The calculated transmittance spectrum of TiO2/Au/TiO2 matches the measured spectrum quite well. However, the calcualted transmittance of TiO2/Ag/TiO2 is higher than its measured transmittance. The presence of voids in the Ag film is probably responsible for the decreased transmittance of the TiO2/Ag/TiO2 sample, and the continuous Au film in TiO2/Au/TiO2 ensures a good agreement between transmittance prediction and measurement. Our approach is a reliable tool to predict the optical transmittance of TCE with continuous films, and it can efficiently expedite the selection from numerous possible combinations of transparent metal oxides and metals when developing TCEs for future photovoltaic applications. It can also serve as a convenient method to assess the continuity of embedded metal layer.

  11. Improving the efficiency and accuracy of individual tree crown delineation from high-density LiDAR data

    NASA Astrophysics Data System (ADS)

    Hu, Baoxin; Li, Jili; Jing, Linhai; Judah, Aaron

    2014-02-01

    Canopy height model (CHM) derived from LiDAR (Light Detection And Ranging) data has been commonly used to generate segments of individual tree crowns for forest inventory and sustainable management. However, branches, tree crowns, and tree clusters usually have similar shapes and overlapping sizes, which cause current individual tree crown delineation methods to work less effectively on closed canopy, deciduous or mixedwood forests. In addition, the potential of 3-dimentional (3-D) LiDAR data is not fully realized by CHM-oriented methods. In this study, a framework was proposed to take advantage of the simplicity of a CHM-oriented method, detailed vertical structures of tree crowns represented in high-density LiDAR data, and any prior knowledge of tree crowns. The efficiency and accuracy of ITC delineation can be improved. This framework consists of five steps: (1) determination of dominant crown sizes; (2) generation of initial tree segments using a multi-scale segmentation method; (3) identification of “problematic” segments; (4) determination of the number of trees based on the 3-D LiDAR points in each of the identified segments; and (5) refinement of the “problematic” segments by splitting and merging operations. The proposed framework was efficient, since the detailed examination of 3-D LiDAR points was not applied to all initial segments, but only to those needed further evaluations based on prior knowledge. It was also demonstrated to be effective based on an experiment on natural forests in Ontario, Canada. The proposed framework and specific methods yielded crown maps having a good consistency with manual and visual interpretation. The automated method correctly delineated about 74% and 72% of the tree crowns in two plots with mixedwood and deciduous trees, respectively.

  12. Prognosis Predicting Score for Endovascular Treatment of Aneurysmal Subarachnoid Hemorrhage: A Risk Modeling Study for Individual Elderly Patients.

    PubMed

    Duan, Guoli; Yang, Pengfei; Li, Qiang; Zuo, Qiao; Zhang, Lei; Hong, Bo; Xu, Yi; Zhao, Wenyuan; Liu, Jianmin; Huang, Qinghai

    2016-02-01

    The elderly patients with aneurysmal subarachnoid hemorrhage (aSAH) have a greater risk of poor clinical outcome after endovascular treatment (EVT) than younger patients do. Hence, it is necessary to explore which factors are associated with poor outcome and develop a predictive score specifically for elderly patients with aSAH receiving EVT. The aim of this study was to develop and validate a predictive score for 1-year outcomes in individual elderly patients with aSAH underwent EVT.In this 10-year prospective study, 520 consecutive aSAH elderly (age ≥ 60 years) patients underwent EVT in a single center were included. The risk factors, periprocedural, and 1-year follow-up data of all patients were entered in a specific prospective database. The modified Rankin scale was used for evaluating clinical outcome. To optimize the model's predictive capacity, the original matrix was randomly divided in 2 submatrices (learning and testing). The predictive score was developed using Arabic numerals for all variables based on the variable coefficients (β) of multivariable logistic regression analysis in the learning set and the predictive performance evaluation was assessed in the testing set. The risk classes were constructed using classification criteria based on sensitivity and specificity. The poor outcome rate at 1 year was 26.15%. Six risk factors, including age, hypertension, Hunt-Hess scale, Fisher scale, aneurysm location, and periprocedural complications, were independently associated with poor outcome and assembled the Changhai score. The discriminative power analysis with the area under the receiver operating characteristic curve (AUC) of the Changhai score was statistically significant (0.864, 0.824-0.904, P < 0.001). The sensitivity and specificity of the Changhai score were 82.07% and 78.06%, respectively. Our study indicated that age, hypertension, Hunt-Hess scale, Fisher scale, aneurysm location, and periprocedural complications were independent risk

  13. Predicting anti-fat attitudes: individual differences based on actual and perceived body size, weight importance, entity mindset, and ethnicity.

    PubMed

    Scott, Shannon Rich; Rosen, Lisa H

    2015-06-01

    The purpose of the current study was to examine the relative impact of actual and perceived weight, weight importance, entity mindset, and ethnicity on anti-fat attitudes as well as to examine whether certain variables play the role of mediator. Participants included a multiethnic U.S. sample of 923 female undergraduates who completed a series of measures online. Lower BMI, higher perceived weight, higher importance of weight, endorsement of an entity mindset, and identification as White as compared to Black, Hispanic, or Asian predicted higher overall anti-fat attitudes. Examination of the individual Antifat Attitudes Questionnaire subscales (i.e. dislike, fear of fat, and willpower) using Relative Weight Analysis suggested that weight importance is an important predictor of multiple aspects of anti-fat attitudes. In addition, weight importance mediated the relationship between perceived weight and fear of fat as well as the relationship between ethnicity and dislike. Implications of findings and future research directions are discussed.

  14. Individual differences in common factors of emotional traits and executive functions predict functional connectivity of the amygdala.

    PubMed

    Rohr, C S; Dreyer, F R; Aderka, I M; Margulies, D S; Frisch, S; Villringer, A; Okon-Singer, H

    2015-10-15

    Evidence suggests that individual differences in emotion control are associated with frontoparietal-limbic networks and linked to emotional traits and executive functions. In a first attempt to directly target the link between emotional traits and executive functions using resting-state fMRI analysis, 43 healthy adults completed a test battery including executive tasks and emotional trait self-assessments that were subjected to a principal component analysis. Of the three factors detected, two explained 40.4% of the variance and were further investigated. Both factors suggest a relation between emotional traits and executive functions. Specifically, the first factor consisted of measures related to inhibitory control and negative affect, and the second factor was related to reward and positive affect. To investigate whether this interplay between emotional traits and executive functions is reflected in neural connectivity, we used resting-state fMRI to explore the functional connectivity of the amygdala as a starting point, and progressed to other seed-based analyses based on the initial findings. We found that the first factor predicted the strength of connectivity between brain regions known to be involved in the cognitive control of emotion, including the amygdala and the dorsolateral prefrontal cortex, whereas the second factor predicted the strength of connectivity between brain regions known to be involved in reward and attention, including the amygdala, the caudate and the thalamus. These findings suggest that individual differences in the ability to inhibit negative affect are mediated by prefrontal-limbic pathways, while the ability to be positive and use rewarding information is mediated by a network that includes the amygdala and thalamostriatal regions.

  15. Individual differences in decision making and reward processing predict changes in cannabis use: a prospective functional magnetic resonance imaging study.

    PubMed

    Cousijn, Janna; Wiers, Reinout W; Ridderinkhof, K Richard; van den Brink, Wim; Veltman, Dick J; Porrino, Linda J; Goudriaan, Anna E

    2013-11-01

    Decision-making deficits are thought to play an important role in the development and persistence of substance use disorders. Individual differences in decision-making abilities and their underlying neurocircuitry may, therefore, constitute an important predictor for the course of substance use and the development of substance use disorders. Here, we investigate the predictive value of decision making and neural mechanisms underlying decision making for future cannabis use and problem severity in a sample of heavy cannabis users. Brain activity during a monetary decision-making task (Iowa gambling task) was compared between 32 heavy cannabis users and 41 matched non-using controls using functional magnetic resonance imaging. In addition, within the group of heavy cannabis users, associations were examined between task-related brain activations, cannabis use and cannabis use-related problems at baseline, and change in cannabis use and problem severity after a 6-month follow-up. Despite normal task performance, heavy cannabis users compared with controls showed higher activation during wins in core areas associated with decision making. Moreover, within the group of heavy cannabis users, win-related activity and activity anticipating loss outcomes in areas generally involved in executive functions predicted change in cannabis use after 6 months. These findings are consistent with previous studies and point to abnormal processing of motivational information in heavy cannabis users. A new finding is that individuals who are biased toward immediate rewards have a higher probability of increasing drug use, highlighting the importance of the relative balance between motivational processes and regulatory executive processes in the development of substance use disorders.

  16. Effectiveness of Shrinkage and Variable Selection Methods for the Prediction of Complex Human Traits using Data from Distantly Related Individuals

    PubMed Central

    Pérez‐Rodríguez, Paulino; Veturi, Yogasudha; Simianer, Henner; de los Campos, Gustavo

    2015-01-01

    Summary Genome‐wide association studies (GWAS) have detected large numbers of variants associated with complex human traits and diseases. However, the proportion of variance explained by GWAS‐significant single nucleotide polymorphisms has been usually small. This brought interest in the use of whole‐genome regression (WGR) methods. However, there has been limited research on the factors that affect prediction accuracy (PA) of WGRs when applied to human data of distantly related individuals. Here, we examine, using real human genotypes and simulated phenotypes, how trait complexity, marker‐quantitative trait loci (QTL) linkage disequilibrium (LD), and the model used affect the performance of WGRs. Our results indicated that the estimated rate of missing heritability is dependent on the extent of marker‐QTL LD. However, this parameter was not greatly affected by trait complexity. Regarding PA our results indicated that: (a) under perfect marker‐QTL LD WGR can achieve moderately high prediction accuracy, and with simple genetic architectures variable selection methods outperform shrinkage procedures and (b) under imperfect marker‐QTL LD, variable selection methods can achieved reasonably good PA with simple or moderately complex genetic architectures; however, the PA of these methods deteriorated as trait complexity increases and with highly complex traits variable selection and shrinkage methods both performed poorly. This was confirmed with an analysis of human height. PMID:25600682

  17. Developmental Trajectories in Toddlers’ Self-restraint Predict Individual Differences in Executive Functions 14 Years Later: A Behavioral Genetic Analysis

    PubMed Central

    Friedman, Naomi P.; Miyake, Akira; Robinson, JoAnn L.; Hewitt, John K.

    2011-01-01

    We examined whether self-restraint in early childhood predicted individual differences in three executive functions (EFs; inhibiting prepotent responses, updating working memory, and shifting task sets) in late adolescence in a sample of ~950 twins. At ages 14, 20, 24, and 36 months, the children were shown an attractive toy and told not to touch it for 30 seconds. Latency to touch the toy increased with age, and latent class growth modeling distinguished two groups of children that differed in their latencies to touch the toy at all 4 time points. Using confirmatory factor analysis, the three EFs (measured with latent variables at age 17 years) were decomposed into a Common EF factor (isomorphic to response inhibition ability) and two factors specific to updating and shifting, respectively. Less restrained children had significantly lower scores on the Common EF factor, equivalent scores on the Updating-specific factor, and higher scores on the Shifting-specific factor than the more restrained children. The less restrained group also had lower IQ scores, but this effect was entirely mediated by the EF components. Twin models indicated that the associations were primarily genetic in origin for the Common EF variable but split between genetics and nonshared environment for the Shifting-specific variable. These results suggest a biological relation between individual differences in self-restraint and EFs, one that begins early in life and persists into late adolescence. PMID:21668099

  18. Experimental evaluation of a mathematical model for predicting transfer efficiency of a high volume-low pressure air spray gun.

    PubMed

    Tan, Y M; Flynn, M R

    2000-10-01

    The transfer efficiency of a spray-painting gun is defined as the amount of coating applied to the workpiece divided by the amount sprayed. Characterizing this transfer process allows for accurate estimation of the overspray generation rate, which is important for determining a spray painter's exposure to airborne contaminants. This study presents an experimental evaluation of a mathematical model for predicting the transfer efficiency of a high volume-low pressure spray gun. The effects of gun-to-surface distance and nozzle pressure on the agreement between the transfer efficiency measurement and prediction were examined. Wind tunnel studies and non-volatile vacuum pump oil in place of commercial paint were used to determine transfer efficiency at nine gun-to-surface distances and four nozzle pressure levels. The mathematical model successfully predicts transfer efficiency within the uncertainty limits. The least squares regression between measured and predicted transfer efficiency has a slope of 0.83 and an intercept of 0.12 (R2 = 0.98). Two correction factors were determined to improve the mathematical model. At higher nozzle pressure settings, 6.5 psig and 5.5 psig, the correction factor is a function of both gun-to-surface distance and nozzle pressure level. At lower nozzle pressures, 4 psig and 2.75 psig, gun-to-surface distance slightly influences the correction factor, while nozzle pressure has no discernible effect. PMID:11036729

  19. Normalization of Pain-Evoked Neural Responses Using Spontaneous EEG Improves the Performance of EEG-Based Cross-Individual Pain Prediction

    PubMed Central

    Bai, Yanru; Huang, Gan; Tu, Yiheng; Tan, Ao; Hung, Yeung Sam; Zhang, Zhiguo

    2016-01-01

    An effective physiological pain assessment method that complements the gold standard of self-report is highly desired in pain clinical research and practice. Recent studies have shown that pain-evoked electroencephalography (EEG) responses could be used as a readout of perceived pain intensity. Existing EEG-based pain assessment is normally achieved by cross-individual prediction (i.e., to train a prediction model from a group of individuals and to apply the model on a new individual), so its performance is seriously hampered by the substantial inter-individual variability in pain-evoked EEG responses. In this study, to reduce the inter-individual variability in pain-evoked EEG and to improve the accuracy of cross-individual pain prediction, we examined the relationship between pain-evoked EEG, spontaneous EEG, and pain perception on a pain EEG dataset, where a large number of laser pulses (>100) with a wide energy range were delivered. Motivated by our finding that an individual's pain-evoked EEG responses is significantly correlated with his/her spontaneous EEG in terms of magnitude, we proposed a normalization method for pain-evoked EEG responses using one's spontaneous EEG to reduce the inter-individual variability. In addition, a nonlinear relationship between the level of pain perception and pain-evoked EEG responses was obtained, which inspired us to further develop a new two-stage pain prediction strategy, a binary classification of low-pain and high-pain trials followed by a continuous prediction for high-pain trials only, both of which used spontaneous-EEG-normalized magnitudes of evoked EEG responses as features. Results show that the proposed normalization strategy can effectively reduce the inter-individual variability in pain-evoked responses, and the two-stage pain prediction method can lead to a higher prediction accuracy. PMID:27148028

  20. Autonomic dysfunction independently predicts poor cardiovascular outcomes in asymptomatic individuals with type 2 diabetes in the DIAD study

    PubMed Central

    Wackers, Frans JTh; Inzucchi, Silvio E; Jose, Powell; Weiss, Curtis; Davey, Janice A; Heller, Gary V; Iskandrian, Ami E; Young, Lawrence H

    2015-01-01

    Objective: The primary aim of this secondary analysis was to determine whether cardiac autonomic neuropathy independently predicted adverse cardiac outcomes in asymptomatic individuals with type 2 diabetes. Additional aims include the determination of the correlation of standard autonomic testing measures and power spectral analysis of heart rate variability, and the association of diabetes-related and cardiac risk factors with cardiac autonomic neuropathy measures. Methods: Cardiac autonomic neuropathy was assessed at the study entry into the Detection of Ischemia in Asymptomatic Diabetics study, using autonomic heart rate and blood pressure testing, and power spectral analysis of heart rate variability. All participants were prospectively followed for the composite clinical outcome of cardiac death, acute coronary syndromes, heart failure, or coronary revascularization. Results: Over 5 years of follow-up, 94 of 1119 (8.4%) subjects developed symptomatic cardiac disease. In unadjusted bivariate analyses, abnormalities in several cardiac autonomic neuropathy tests, including lower Valsalva and Standing Heart Rate Ratios, higher resting Heart Rate, greater systolic blood pressure decrease on standing, and lower low-frequency power, were predictive of symptomatic disease. Independent predictors of poor cardiac outcome were a lower Valsalva Heart Rate Ratio, non-Black ethnicity, longer diabetes duration, higher glycated hemoglobin (HbA1c), insulin use, reported numbness in the extremities, higher pulse pressure, family history of coronary artery disease, and higher waist-to-hip ratio. Clinical factors independently associated with a lower Valsalva Heart Rate Ratio were insulin use, clinical proteinuria, higher pulse pressure, use of angiotensin-converting enzyme inhibitor and non-Black ethnicity. Conclusion: Cardiac autonomic neuropathy predicted adverse cardiac outcomes in asymptomatic type 2 diabetes without known cardiac disease. Clinical variables may help to

  1. Stress and success: individual differences in the glucocorticoid stress response predict behavior and reproductive success under high predation risk.

    PubMed

    Vitousek, Maren N; Jenkins, Brittany R; Safran, Rebecca J

    2014-11-01

    A fundamental element of how vertebrates respond to stressors is by rapidly elevating circulating glucocorticoid hormones. Individual variation in the magnitude of the glucocorticoid stress response has been linked with reproductive success and survival. But while the adaptive value of this response is believed to stem in part from changes in the expression of hormone-mediated behaviors, it is not clear how the behavior of stronger and weaker glucocorticoid responders differs during reproduction, or during exposure to ecologically relevant stressors. Here we report that in a population of barn swallows (Hirundo rustica erythrogaster) experiencing high rates of nest predation, circulating levels of corticosterone (the primary avian glucocorticoid) during exposure to a standardized stressor predict aspects of subsequent behavior and fitness. Individuals that mounted a stronger corticosterone stress response during the early reproductive period did not differ in clutch size, but fledged fewer offspring. Parents with higher stress-induced corticosterone during the early reproductive period later provisioned their nestlings at lower rates. Additionally, in the presence of a model predator stress-induced corticosterone was positively associated with the latency to return to the nest, but only among birds that were observed to return. Model comparisons revealed that stress-induced hormones were better predictors of the behavioral and fitness effects of exposure to transient, ecologically relevant stressors than baseline corticosterone. These findings are consistent with functional links between individual variation in the hormonal and behavioral response to stressors. If such links occur, then selection on the heritable components of the corticosterone stress response could promote adaptation to novel environments or predation regimes.

  2. Predictable and efficient carbon sequestration in the North Pacific Ocean supported by symbiotic nitrogen fixation

    PubMed Central

    Karl, David M.; Church, Matthew J.; Dore, John E.; Letelier, Ricardo M.; Mahaffey, Claire

    2012-01-01

    The atmospheric and deep sea reservoirs of carbon dioxide are linked via physical, chemical, and biological processes. The last of these include photosynthesis, particle settling, and organic matter remineralization, and are collectively termed the “biological carbon pump.” Herein, we present results from a 13-y (1992–2004) sediment trap experiment conducted in the permanently oligotrophic North Pacific Subtropical Gyre that document a large, rapid, and predictable summertime (July 15–August 15) pulse in particulate matter export to the deep sea (4,000 m). Peak daily fluxes of particulate matter during the summer export pulse (SEP) average 408, 283, 24.1, 1.1, and 67.5 μmol·m−2·d−1 for total carbon, organic carbon, nitrogen, phosphorus (PP), and biogenic silica, respectively. The SEP is approximately threefold greater than mean wintertime particle fluxes and fuels more efficient carbon sequestration because of low remineralization during downward transit that leads to elevated total carbon/PP and organic carbon/PP particle stoichiometry (371:1 and 250:1, respectively). Our long-term observations suggest that seasonal changes in the microbial assemblage, namely, summertime increases in the biomass and productivity of symbiotic nitrogen-fixing cyanobacteria in association with diatoms, are the main cause of the prominent SEP. The recurrent SEP is enigmatic because it is focused in time despite the absence of any obvious predictable stimulus or habitat condition. We hypothesize that changes in day length (photoperiodism) may be an important environmental cue to initiate aggregation and subsequent export of organic matter to the deep sea. PMID:22308450

  3. Functional Connectivity Between Superior Parietal Lobule and Primary Visual Cortex "at Rest" Predicts Visual Search Efficiency.

    PubMed

    Bueichekú, Elisenda; Ventura-Campos, Noelia; Palomar-García, María-Ángeles; Miró-Padilla, Anna; Parcet, María-Antonia; Ávila, César

    2015-10-01

    Spatiotemporal activity that emerges spontaneously "at rest" has been proposed to reflect individual a priori biases in cognitive processing. This research focused on testing neurocognitive models of visual attention by studying the functional connectivity (FC) of the superior parietal lobule (SPL), given its central role in establishing priority maps during visual search tasks. Twenty-three human participants completed a functional magnetic resonance imaging session that featured a resting-state scan, followed by a visual search task based on the alphanumeric category effect. As expected, the behavioral results showed longer reaction times and more errors for the within-category (i.e., searching a target letter among letters) than the between-category search (i.e., searching a target letter among numbers). The within-category condition was related to greater activation of the superior and inferior parietal lobules, occipital cortex, inferior frontal cortex, dorsal anterior cingulate cortex, and the superior colliculus than the between-category search. The resting-state FC analysis of the SPL revealed a broad network that included connections with the inferotemporal cortex, dorsolateral prefrontal cortex, and dorsal frontal areas like the supplementary motor area and frontal eye field. Noteworthy, the regression analysis revealed that the more efficient participants in the visual search showed stronger FC between the SPL and areas of primary visual cortex (V1) related to the search task. We shed some light on how the SPL establishes a priority map of the environment during visual attention tasks and how FC is a valuable tool for assessing individual differences while performing cognitive tasks. PMID:26230367

  4. Functional Connectivity Between Superior Parietal Lobule and Primary Visual Cortex "at Rest" Predicts Visual Search Efficiency.

    PubMed

    Bueichekú, Elisenda; Ventura-Campos, Noelia; Palomar-García, María-Ángeles; Miró-Padilla, Anna; Parcet, María-Antonia; Ávila, César

    2015-10-01

    Spatiotemporal activity that emerges spontaneously "at rest" has been proposed to reflect individual a priori biases in cognitive processing. This research focused on testing neurocognitive models of visual attention by studying the functional connectivity (FC) of the superior parietal lobule (SPL), given its central role in establishing priority maps during visual search tasks. Twenty-three human participants completed a functional magnetic resonance imaging session that featured a resting-state scan, followed by a visual search task based on the alphanumeric category effect. As expected, the behavioral results showed longer reaction times and more errors for the within-category (i.e., searching a target letter among letters) than the between-category search (i.e., searching a target letter among numbers). The within-category condition was related to greater activation of the superior and inferior parietal lobules, occipital cortex, inferior frontal cortex, dorsal anterior cingulate cortex, and the superior colliculus than the between-category search. The resting-state FC analysis of the SPL revealed a broad network that included connections with the inferotemporal cortex, dorsolateral prefrontal cortex, and dorsal frontal areas like the supplementary motor area and frontal eye field. Noteworthy, the regression analysis revealed that the more efficient participants in the visual search showed stronger FC between the SPL and areas of primary visual cortex (V1) related to the search task. We shed some light on how the SPL establishes a priority map of the environment during visual attention tasks and how FC is a valuable tool for assessing individual differences while performing cognitive tasks.

  5. Results of the Use of a Model that Predicts Individual Student Attrition to Intervene with Those Who Are Most at Risk

    ERIC Educational Resources Information Center

    Miller, Thomas E.; Tyree, Tracy; Riegler, Keri K.; Herreid, Charlene

    2010-01-01

    This article describes the early outcomes of an ongoing project at the University of South Florida in Tampa that involves using a logistics regression formula derived from pre-matriculation characteristics to predict the risk of individual student attrition. In this piece, the authors will describe the results of the prediction formula and the…

  6. Predicting performance on the Raven’s Matrices: The roles of associative learning and retrieval efficiency

    PubMed Central

    Lilienthal, Lindsey; Tamez, Elaine; Myerson, Joel; Hale, Sandra

    2013-01-01

    Previous studies have shown that performance on Williams and Pearlberg’s (2006) complex associative learning task is a good predictor of fluid intelligence. This task is similar in structure to that used in studying the fan effect (Anderson, 1974), as both tasks involve forming multiple associations and require retrieval in the face of interference. The purpose of the present study was to investigate the relations among complex associative learning, working memory, and fluid intelligence. Specifically, we asked whether retrieval efficiency, as measured by the fan effect, could account for the relation between complex associative learning and performance on Raven’s Advanced Progressive Matrices. Consistent with previous findings, complex associative learning predicted Raven’s performance, but the fan effect did not account for this relation. Notably, the learning phase of the fan effect task was significantly correlated with both complex associative learning and Raven’s performance, providing further support for the importance of learning as a predictor of fluid intelligence. PMID:24187609

  7. Nonlinear predictive control for durability enhancement and efficiency improvement in a fuel cell power system

    NASA Astrophysics Data System (ADS)

    Luna, Julio; Jemei, Samir; Yousfi-Steiner, Nadia; Husar, Attila; Serra, Maria; Hissel, Daniel

    2016-10-01

    In this work, a nonlinear model predictive control (NMPC) strategy is proposed to improve the efficiency and enhance the durability of a proton exchange membrane fuel cell (PEMFC) power system. The PEMFC controller is based on a distributed parameters model that describes the nonlinear dynamics of the system, considering spatial variations along the gas channels. Parasitic power from different system auxiliaries is considered, including the main parasitic losses which are those of the compressor. A nonlinear observer is implemented, based on the discretised model of the PEMFC, to estimate the internal states. This information is included in the cost function of the controller to enhance the durability of the system by means of avoiding local starvation and inappropriate water vapour concentrations. Simulation results are presented to show the performance of the proposed controller over a given case study in an automotive application (New European Driving Cycle). With the aim of representing the most relevant phenomena that affects the PEMFC voltage, the simulation model includes a two-phase water model and the effects of liquid water on the catalyst active area. The control model is a simplified version that does not consider two-phase water dynamics.

  8. Predicting the disinfection efficiency range in chlorine contact tanks through a CFD-based approach.

    PubMed

    Angeloudis, Athanasios; Stoesser, Thorsten; Falconer, Roger A

    2014-09-01

    In this study three-dimensional computational fluid dynamics (CFD) models, incorporating appropriately selected kinetic models, were developed to simulate the processes of chlorine decay, pathogen inactivation and the formation of potentially carcinogenic by-products in disinfection contact tanks (CTs). Currently, the performance of CT facilities largely relies on Hydraulic Efficiency Indicators (HEIs), extracted from experimentally derived Residence Time Distribution (RTD) curves. This approach has more recently been aided with the application of CFD models, which can be calibrated to predict accurately RTDs, enabling the assessment of disinfection facilities prior to their construction. However, as long as it depends on HEIs, the CT design process does not directly take into consideration the disinfection biochemistry which needs to be optimized. The main objective of this study is to address this issue by refining the modelling practices to simulate some reactive processes of interest, while acknowledging the uneven contact time stemming from the RTD curves. Initially, the hydraulic performances of seven CT design variations were reviewed through available experimental and computational data. In turn, the same design configurations were tested using numerical modelling techniques, featuring kinetic models that enable the quantification of disinfection operational parameters. Results highlight that the optimization of the hydrodynamic conditions facilitates a more uniform disinfectant contact time, which correspond to greater levels of pathogen inactivation and a more controlled by-product accumulation.

  9. Prediction of the collection efficiency, the porosity, and the pressure drop across filter cakes in particulate air filtration

    NASA Astrophysics Data System (ADS)

    Al-Otoom, Awni Y.

    This study presents a new statistical model to predict the collection efficiency, cake thickness, cake porosity, and pressure drop across filter cakes during the particulate filtration of gases. This model is based on generation of a random distribution of particle sizes and particle falling locations. The model predicts the cake collection efficiency, which was found to be strongly dependent on the ratio of the mean particle size to the mean pore size of the filter medium. The average cake porosity decreases with increasing cake thickness and the pressure drop increases when the mean particle diameter decreases.

  10. Chaos in balance: non-linear measures of postural control predict individual variations in visual illusions of motion.

    PubMed

    Apthorp, Deborah; Nagle, Fintan; Palmisano, Stephen

    2014-01-01

    Visually-induced illusions of self-motion (vection) can be compelling for some people, but they are subject to large individual variations in strength. Do these variations depend, at least in part, on the extent to which people rely on vision to maintain their postural stability? We investigated by comparing physical posture measures to subjective vection ratings. Using a Bertec balance plate in a brightly-lit room, we measured 13 participants' excursions of the centre of foot pressure (CoP) over a 60-second period with eyes open and with eyes closed during quiet stance. Subsequently, we collected vection strength ratings for large optic flow displays while seated, using both verbal ratings and online throttle measures. We also collected measures of postural sway (changes in anterior-posterior CoP) in response to the same visual motion stimuli while standing on the plate. The magnitude of standing sway in response to expanding optic flow (in comparison to blank fixation periods) was predictive of both verbal and throttle measures for seated vection. In addition, the ratio between eyes-open and eyes-closed CoP excursions during quiet stance (using the area of postural sway) significantly predicted seated vection for both measures. Interestingly, these relationships were weaker for contracting optic flow displays, though these produced both stronger vection and more sway. Next we used a non-linear analysis (recurrence quantification analysis, RQA) of the fluctuations in anterior-posterior position during quiet stance (both with eyes closed and eyes open); this was a much stronger predictor of seated vection for both expanding and contracting stimuli. Given the complex multisensory integration involved in postural control, our study adds to the growing evidence that non-linear measures drawn from complexity theory may provide a more informative measure of postural sway than the conventional linear measures. PMID:25462216

  11. Chaos in Balance: Non-Linear Measures of Postural Control Predict Individual Variations in Visual Illusions of Motion

    PubMed Central

    Apthorp, Deborah; Nagle, Fintan; Palmisano, Stephen

    2014-01-01

    Visually-induced illusions of self-motion (vection) can be compelling for some people, but they are subject to large individual variations in strength. Do these variations depend, at least in part, on the extent to which people rely on vision to maintain their postural stability? We investigated by comparing physical posture measures to subjective vection ratings. Using a Bertec balance plate in a brightly-lit room, we measured 13 participants' excursions of the centre of foot pressure (CoP) over a 60-second period with eyes open and with eyes closed during quiet stance. Subsequently, we collected vection strength ratings for large optic flow displays while seated, using both verbal ratings and online throttle measures. We also collected measures of postural sway (changes in anterior-posterior CoP) in response to the same visual motion stimuli while standing on the plate. The magnitude of standing sway in response to expanding optic flow (in comparison to blank fixation periods) was predictive of both verbal and throttle measures for seated vection. In addition, the ratio between eyes-open and eyes-closed CoP excursions during quiet stance (using the area of postural sway) significantly predicted seated vection for both measures. Interestingly, these relationships were weaker for contracting optic flow displays, though these produced both stronger vection and more sway. Next we used a non-linear analysis (recurrence quantification analysis, RQA) of the fluctuations in anterior-posterior position during quiet stance (both with eyes closed and eyes open); this was a much stronger predictor of seated vection for both expanding and contracting stimuli. Given the complex multisensory integration involved in postural control, our study adds to the growing evidence that non-linear measures drawn from complexity theory may provide a more informative measure of postural sway than the conventional linear measures. PMID:25462216

  12. A novel total flux normalized correlation equation for predicting single-collector efficiency

    NASA Astrophysics Data System (ADS)

    Sethi, R.; Messina, F.; Marchisio, D.

    2015-12-01

    In this study a novel total flux normalized correlation equation is proposed for predicting single-collector efficiency under a broad range of parameters. The correlation equation does not exploit the additivity approach introduced by Yao et al. (1971), but includes mixed terms that account for the mutual interaction of concomitant transport mechanisms (i.e., advection, gravity and Brownian motion) and of finite size of the particles (steric effect). The correlation equation is based on a combination of Eulerian and Lagrangian simulations performed, under Smoluchowski-Levich conditions, in a geometry which consists of a sphere enveloped by a cylindrical control volume. The normalization of the deposited flux is performed accounting for all of the particles entering into the control volume through all transport mechanisms (not just the upstream convective flux as conventionally done) to provide efficiency values lower than one over a wide range of parameters. In order to guarantee the independence of each term, the correlation equation is derived through a rigorous hierarchical parameter estimation process, accounting for single and mutual interacting transport mechanisms. The correlation equation, valid both for point and finite-size particles, is extended to include porosity dependency and it is compared with previous models. Reduced forms are proposed by elimination of the less relevant terms.References:F Messina, DL Marchisio, R Sethi . Journal of colloid and interface science 446, (2015) 185-193 T Tosco, DL Marchisio, F Lince, R Sethi, Transport in porous media 96 (1), (2013) 1-20 A Tiraferri, T Tosco, R Sethi Environmental Earth Sciences 63 (4), (2011) 847-859 K.E. Nelson, T.R. Ginn, T. Kemai, Environ Sci Technol 47 (2013) 8078. G. Boccardo, D.L. Marchisio, R. Sethi, J Colloid Interface Sci 417 (2014) 227. H. Ma, J. Pedel, P. Fife, W.P. Johnson, (2009). N. Tufenkji, M. Elimelech, Environ Sci Technol 38 (2004) 529.K.M. Yao, M.M. Habibian, C.R. O'Melia, Environ

  13. Neural disruption to theory of mind predicts daily social functioning in individuals at familial high-risk for schizophrenia.

    PubMed

    Dodell-Feder, David; DeLisi, Lynn E; Hooker, Christine I

    2014-12-01

    Theory-of-mind (ToM) ability is foundational for successful social relationships, and dependent on a neurocognitive system, which includes temporoparietal junction and medial prefrontal cortex. Schizophrenia is associated with ToM impairments, and initial studies demonstrate similar, though more subtle deficits, in unaffected first-degree relatives, indicating that ToM deficits are a potential biomarker for the disorder. Importantly, the social consequences of ToM deficits could create an additional vulnerability factor for individuals at familial high risk (FHR). However, behavioral studies of ToM are inconsistent and virtually nothing is known about the neural basis of ToM in FHR or the relationship between ToM and social functioning. Here, FHR and non-FHR control participants underwent functional MRI scanning while reasoning about a story character's thoughts, emotions or physical appearance. Afterwards, participants completed a 28-day online 'daily-diary' questionnaire in which they reported daily social interactions and degree of ToM reasoning. FHR participants demonstrated less neural activity in bilateral temporoparietal junction when reasoning about thoughts and emotions. Moreover, across all participants, the degree of neural activity during ToM reasoning predicted several aspects of daily social behavior. Results suggest that vulnerability for schizophrenia is associated with neurocognitive deficits in ToM and the degree of deficit is related to day-to-day social functioning.

  14. Neural disruption to theory of mind predicts daily social functioning in individuals at familial high-risk for schizophrenia

    PubMed Central

    Dodell-Feder, David; DeLisi, Lynn E.

    2014-01-01

    Theory-of-mind (ToM) ability is foundational for successful social relationships, and dependent on a neurocognitive system, which includes temporoparietal junction and medial prefrontal cortex. Schizophrenia is associated with ToM impairments, and initial studies demonstrate similar, though more subtle deficits, in unaffected first-degree relatives, indicating that ToM deficits are a potential biomarker for the disorder. Importantly, the social consequences of ToM deficits could create an additional vulnerability factor for individuals at familial high risk (FHR). However, behavioral studies of ToM are inconsistent and virtually nothing is known about the neural basis of ToM in FHR or the relationship between ToM and social functioning. Here, FHR and non-FHR control participants underwent functional MRI scanning while reasoning about a story character’s thoughts, emotions or physical appearance. Afterwards, participants completed a 28-day online ‘daily-diary’ questionnaire in which they reported daily social interactions and degree of ToM reasoning. FHR participants demonstrated less neural activity in bilateral temporoparietal junction when reasoning about thoughts and emotions. Moreover, across all participants, the degree of neural activity during ToM reasoning predicted several aspects of daily social behavior. Results suggest that vulnerability for schizophrenia is associated with neurocognitive deficits in ToM and the degree of deficit is related to day-to-day social functioning. PMID:24396009

  15. A method for predicting DCT-based denoising efficiency for grayscale images corrupted by AWGN and additive spatially correlated noise

    NASA Astrophysics Data System (ADS)

    Rubel, Aleksey S.; Lukin, Vladimir V.; Egiazarian, Karen O.

    2015-03-01

    Results of denoising based on discrete cosine transform for a wide class of images corrupted by additive noise are obtained. Three types of noise are analyzed: additive white Gaussian noise and additive spatially correlated Gaussian noise with middle and high correlation levels. TID2013 image database and some additional images are taken as test images. Conventional DCT filter and BM3D are used as denoising techniques. Denoising efficiency is described by PSNR and PSNR-HVS-M metrics. Within hard-thresholding denoising mechanism, DCT-spectrum coefficient statistics are used to characterize images and, subsequently, denoising efficiency for them. Results of denoising efficiency are fitted for such statistics and efficient approximations are obtained. It is shown that the obtained approximations provide high accuracy of prediction of denoising efficiency.

  16. Acoustic Prediction Methodology and Test Validation for an Efficient Low-Noise Hybrid Wing Body Subsonic Transport

    NASA Technical Reports Server (NTRS)

    Kawai, Ronald T. (Compiler)

    2011-01-01

    This investigation was conducted to: (1) Develop a hybrid wing body subsonic transport configuration with noise prediction methods to meet the circa 2007 NASA Subsonic Fixed Wing (SFW) N+2 noise goal of -52 dB cum relative to FAR 36 Stage 3 (-42 dB cum re: Stage 4) while achieving a -25% fuel burned compared to current transports (re :B737/B767); (2) Develop improved noise prediction methods for ANOPP2 for use in predicting FAR 36 noise; (3) Design and fabricate a wind tunnel model for testing in the LaRC 14 x 22 ft low speed wind tunnel to validate noise predictions and determine low speed aero characteristics for an efficient low noise Hybrid Wing Body configuration. A medium wide body cargo freighter was selected to represent a logical need for an initial operational capability in the 2020 time frame. The Efficient Low Noise Hybrid Wing Body (ELNHWB) configuration N2A-EXTE was evolved meeting the circa 2007 NRA N+2 fuel burn and noise goals. The noise estimates were made using improvements in jet noise shielding and noise shielding prediction methods developed by UC Irvine and MIT. From this the Quiet Ultra Integrated Efficient Test Research Aircraft #1 (QUIET-R1) 5.8% wind tunnel model was designed and fabricated.

  17. Individual motile CD4+ T cells can participate in efficient multi-killing through conjugation to multiple tumor cells

    PubMed Central

    Liadi, Ivan; Singh, Harjeet; Romain, Gabrielle; Rey-Villamizar, Nicolas; Merouane, Amine; Adolacion, Jay R T.; Kebriaei, Partow; Huls, Helen; Qiu, Peng; Roysam, Badrinath; Cooper, Laurence J.N.; Varadarajan, Navin

    2015-01-01

    T cells genetically modified to express a CD19-specific chimeric antigen receptor (CAR) for the investigational treatment of B-cell malignancies comprise a heterogeneous population, and their ability to persist and participate in serial killing of tumor cells is a predictor of therapeutic success. We implemented Timelapse Imaging Microscopy In Nanowell Grids (TIMING) to provide direct evidence that CD4+CAR+ T cells (CAR4 cells) can engage in multi-killing via simultaneous conjugation to multiple tumor cells. Comparisons of the CAR4 cells and CD8+CAR+ T cells (CAR8 cells) demonstrate that while CAR4 cells can participate in killing and multi-killing, they do so at slower rates, likely due to the lower Granzyme B content. Significantly, in both sets of T cells, a minor sub-population of individual T cells identified by their high motility, demonstrated efficient killing of single tumor cells. By comparing both the multi-killer and single killer CAR+ T cells it appears that the propensity and kinetics of T-cell apoptosis was modulated by the number of functional conjugations. T cells underwent rapid apoptosis, and at higher frequencies, when conjugated to single tumor cells in isolation and this effect was more pronounced on CAR8 cells. Our results suggest that the ability of CAR+ T cells to participate in multi-killing should be evaluated in the context of their ability to resist activation induced cell death (AICD). We anticipate that TIMING may be utilized to rapidly determine the potency of T-cell populations and may facilitate the design and manufacture of next-generation CAR+ T cells with improved efficacy. PMID:25711538

  18. Diagnostic, prognostic and predictive value of MicroRNA-21 in breast cancer patients, their daughters and healthy individuals

    PubMed Central

    Usmani, Ambreen; Shoro, Amir Ali; Memon, Zahida; Hussain, Mehvish; Rehman, Rehana

    2015-01-01

    MicroRNA-21 (miR-21) located on 17q23.1 expressed in breast cancer has anti-apoptotic ability and causes tumor cell growth. It is also involved in functions such as signal transduction pathways effecting normal cell growth and differentiation. The primary objective of the study was to identify presence of miR-21 in the serum levels of stage III invasive ductal carcinoma patients and compare its expression with age matched healthy individuals and daughters of index cases. The secondary objective was to evaluate the significance of serum miR-21 gene expression with histologically proven estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) proteins. A total of 132 subjects were recruited: 50 (cases) of stage III invasive ductal carcinoma patients who had not undergone any chemotherapy or surgery were randomly picked with exclusion of females with other types of breast carcinoma. Age-matched, 50 healthy individuals (control A) were selected by purposive sampling after confirmation of no palpable lump/s in their breasts together with 32 daughters of index cases (control B). Serum tests were run on Real Time quantitative Reverse Transcription PCR, threshold cycle was determined and fold change calculated.Normality of continuous variables was assessed by Shapiro-Wilk’s test, groups compared by student t-test, Mann-Whitney test and Fisher exact test, P-value ≤ 0.05 was considered significant. We observed that miR-21 was significantly higher in cases as compared to control A and B (P = 0.001) however control B showed significant gene expression as compared to control A (P = 0.001). The cases were also divided as positive or negative for ER, PR and HER2. High expression of miR-21 in females with stage III invasive ductal carcinoma had been calculated as compared to its age matched healthy subjects. It was observed that triple negative cases showed a greater expression of gene as compared to other groups (P = 0

  19. Molecular value predictions: associations with beef quality, carcass, production, behavior, and efficiency phenotypes in Brahman cattle.

    PubMed

    Greenwood, P L; Cafe, L M; McIntyre, B L; Geesink, G H; Thompson, J M; Polkinghorne, R; Pethick, D W; Robinson, D L

    2013-12-01

    Data from 2 previously published experiments, New South Wales (NSW; n = 161) and Western Australia (WA; n = 135), were used to test molecular value predictions (MVP), generated from commercially available gene markers, on economically important traits of Bos indicus (Brahman) cattle. Favorable tenderness MVP scores were associated with reduced shear force values of strip loin (LM) steaks aged 7 d from Achilles-hung carcasses (P ≤ 0.06), as well as steaks aged 1 (P ≤ 0.08) or 7 d (P ≤ 0.07) from carcasses hung from the pelvis (tenderstretch). Favorable tenderness MVP scores were also associated with improved consumer tenderness ratings for strip loin steaks aged 7 d and either Achilles hung (P ≤ 0.006) or tenderstretched (P ≤ 0.07). Similar results were observed in NSW for rump (top butt; gluteus medius) steaks, with favorable tenderness MVP scores associated with more tender (P = 0.006) and acceptable (P = 0.008) beef. Favorable marbling MVP scores were associated with improved (P ≤ 0.021) marbling scores and intramuscular fat (IMF) content in the NSW experiment, despite low variation in marbling in the Brahman cattle. For the WA experiment, however, there were no (P ≥ 0.71) relationships between marbling MVP and marbling scores or IMF content. Although residual (net) feed intake (RFI) was not associated (P = 0.63) with the RFI (feed efficiency) MVP, the RFI MVP was adversely associated with LM tenderness and acceptability of 7-d-aged Achilles-hung carcasses in NSW (P ≤ 0.031) and WA (P ≤ 0.037). Some other relationships and trends were noted between the MVP and the other traits, but few reached statistical significance, and none were evident in both experiments. Results from this study provide evidence to support the use of the tenderness MVP. The value of the marbling MVP, which was associated with marbling in only 1 herd, warrants further evaluation; however, there appears to be no evidence to support use of the RFI MVP in Brahman cattle. PMID

  20. Molecular value predictions: associations with beef quality, carcass, production, behavior, and efficiency phenotypes in Brahman cattle.

    PubMed

    Greenwood, P L; Cafe, L M; McIntyre, B L; Geesink, G H; Thompson, J M; Polkinghorne, R; Pethick, D W; Robinson, D L

    2013-12-01

    Data from 2 previously published experiments, New South Wales (NSW; n = 161) and Western Australia (WA; n = 135), were used to test molecular value predictions (MVP), generated from commercially available gene markers, on economically important traits of Bos indicus (Brahman) cattle. Favorable tenderness MVP scores were associated with reduced shear force values of strip loin (LM) steaks aged 7 d from Achilles-hung carcasses (P ≤ 0.06), as well as steaks aged 1 (P ≤ 0.08) or 7 d (P ≤ 0.07) from carcasses hung from the pelvis (tenderstretch). Favorable tenderness MVP scores were also associated with improved consumer tenderness ratings for strip loin steaks aged 7 d and either Achilles hung (P ≤ 0.006) or tenderstretched (P ≤ 0.07). Similar results were observed in NSW for rump (top butt; gluteus medius) steaks, with favorable tenderness MVP scores associated with more tender (P = 0.006) and acceptable (P = 0.008) beef. Favorable marbling MVP scores were associated with improved (P ≤ 0.021) marbling scores and intramuscular fat (IMF) content in the NSW experiment, despite low variation in marbling in the Brahman cattle. For the WA experiment, however, there were no (P ≥ 0.71) relationships between marbling MVP and marbling scores or IMF content. Although residual (net) feed intake (RFI) was not associated (P = 0.63) with the RFI (feed efficiency) MVP, the RFI MVP was adversely associated with LM tenderness and acceptability of 7-d-aged Achilles-hung carcasses in NSW (P ≤ 0.031) and WA (P ≤ 0.037). Some other relationships and trends were noted between the MVP and the other traits, but few reached statistical significance, and none were evident in both experiments. Results from this study provide evidence to support the use of the tenderness MVP. The value of the marbling MVP, which was associated with marbling in only 1 herd, warrants further evaluation; however, there appears to be no evidence to support use of the RFI MVP in Brahman cattle.

  1. Quantitative Analysis of Defects in Silicon. [to predict energy conversion efficiency of silicon samples for solar cells

    NASA Technical Reports Server (NTRS)

    Natesh, R.; Smith, J. M.; Qidwai, H. A.; Bruce, T.

    1979-01-01

    The evaluation and prediction of the conversion efficiency for a variety of silicon samples with differences in structural defects, such as grain boundaries, twin boundaries, precipitate particles, dislocations, etc. are discussed. Quantitative characterization of these structural defects, which were revealed by etching the surface of silicon samples, is performed by using an image analyzer. Due to different crystal growth and fabrication techniques the various types of silicon contain a variety of trace impurity elements and structural defects. The two most important criteria in evaluating the various silicon types for solar cell applications are cost and conversion efficiency.

  2. More Gamma More Predictions: Gamma-Synchronization as a Key Mechanism for Efficient Integration of Classical Receptive Field Inputs with Surround Predictions.

    PubMed

    Vinck, Martin; Bosman, Conrado A

    2016-01-01

    During visual stimulation, neurons in visual cortex often exhibit rhythmic and synchronous firing in the gamma-frequency (30-90 Hz) band. Whether this phenomenon plays a functional role during visual processing is not fully clear and remains heavily debated. In this article, we explore the function of gamma-synchronization in the context of predictive and efficient coding theories. These theories hold that sensory neurons utilize the statistical regularities in the natural world in order to improve the efficiency of the neural code, and to optimize the inference of the stimulus causes of the sensory data. In visual cortex, this relies on the integration of classical receptive field (CRF) data with predictions from the surround. Here we outline two main hypotheses about gamma-synchronization in visual cortex. First, we hypothesize that the precision of gamma-synchronization reflects the extent to which CRF data can be accurately predicted by the surround. Second, we hypothesize that different cortical columns synchronize to the extent that they accurately predict each other's CRF visual input. We argue that these two hypotheses can account for a large number of empirical observations made on the stimulus dependencies of gamma-synchronization. Furthermore, we show that they are consistent with the known laminar dependencies of gamma-synchronization and the spatial profile of intercolumnar gamma-synchronization, as well as the dependence of gamma-synchronization on experience and development. Based on our two main hypotheses, we outline two additional hypotheses. First, we hypothesize that the precision of gamma-synchronization shows, in general, a negative dependence on RF size. In support, we review evidence showing that gamma-synchronization decreases in strength along the visual hierarchy, and tends to be more prominent in species with small V1 RFs. Second, we hypothesize that gamma-synchronized network dynamics facilitate the emergence of spiking output that is

  3. More Gamma More Predictions: Gamma-Synchronization as a Key Mechanism for Efficient Integration of Classical Receptive Field Inputs with Surround Predictions

    PubMed Central

    Vinck, Martin; Bosman, Conrado A.

    2016-01-01

    During visual stimulation, neurons in visual cortex often exhibit rhythmic and synchronous firing in the gamma-frequency (30–90 Hz) band. Whether this phenomenon plays a functional role during visual processing is not fully clear and remains heavily debated. In this article, we explore the function of gamma-synchronization in the context of predictive and efficient coding theories. These theories hold that sensory neurons utilize the statistical regularities in the natural world in order to improve the efficiency of the neural code, and to optimize the inference of the stimulus causes of the sensory data. In visual cortex, this relies on the integration of classical receptive field (CRF) data with predictions from the surround. Here we outline two main hypotheses about gamma-synchronization in visual cortex. First, we hypothesize that the precision of gamma-synchronization reflects the extent to which CRF data can be accurately predicted by the surround. Second, we hypothesize that different cortical columns synchronize to the extent that they accurately predict each other’s CRF visual input. We argue that these two hypotheses can account for a large number of empirical observations made on the stimulus dependencies of gamma-synchronization. Furthermore, we show that they are consistent with the known laminar dependencies of gamma-synchronization and the spatial profile of intercolumnar gamma-synchronization, as well as the dependence of gamma-synchronization on experience and development. Based on our two main hypotheses, we outline two additional hypotheses. First, we hypothesize that the precision of gamma-synchronization shows, in general, a negative dependence on RF size. In support, we review evidence showing that gamma-synchronization decreases in strength along the visual hierarchy, and tends to be more prominent in species with small V1 RFs. Second, we hypothesize that gamma-synchronized network dynamics facilitate the emergence of spiking output that

  4. A method for predicting target drug efficiency in cancer based on the analysis of signaling pathway activation.

    PubMed

    Artemov, Artem; Aliper, Alexander; Korzinkin, Michael; Lezhnina, Ksenia; Jellen, Leslie; Zhukov, Nikolay; Roumiantsev, Sergey; Gaifullin, Nurshat; Zhavoronkov, Alex; Borisov, Nicolas; Buzdin, Anton

    2015-10-01

    A new generation of anticancer therapeutics called target drugs has quickly developed in the 21st century. These drugs are tailored to inhibit cancer cell growth, proliferation, and viability by specific interactions with one or a few target proteins. However, despite formally known molecular targets for every "target" drug, patient response to treatment remains largely individual and unpredictable. Choosing the most effective personalized treatment remains a major challenge in oncology and is still largely trial and error. Here we present a novel approach for predicting target drug efficacy based on the gene expression signature of the individual tumor sample(s). The enclosed bioinformatic algorithm detects activation of intracellular regulatory pathways in the tumor in comparison to the corresponding normal tissues. According to the nature of the molecular targets of a drug, it predicts whether the drug can prevent cancer growth and survival in each individual case by blocking the abnormally activated tumor-promoting pathways or by reinforcing internal tumor suppressor cascades. To validate the method, we compared the distribution of predicted drug efficacy scores for five drugs (Sorafenib, Bevacizumab, Cetuximab, Sorafenib, Imatinib, Sunitinib) and seven cancer types (Clear Cell Renal Cell Carcinoma, Colon cancer, Lung adenocarcinoma, non-Hodgkin Lymphoma, Thyroid cancer and Sarcoma) with the available clinical trials data for the respective cancer types and drugs. The percent of responders to a drug treatment correlated significantly (Pearson's correlation 0.77 p = 0.023) with the percent of tumors showing high drug scores calculated with the current algorithm. PMID:26320181

  5. A method for predicting target drug efficiency in cancer based on the analysis of signaling pathway activation

    PubMed Central

    Artemov, Artem; Aliper, Alexander; Korzinkin, Michael; Lezhnina, Ksenia; Jellen, Leslie; Zhukov, Nikolay; Roumiantsev, Sergey; Gaifullin, Nurshat; Zhavoronkov, Alex; Borisov, Nicolas; Buzdin, Anton

    2015-01-01

    A new generation of anticancer therapeutics called target drugs has quickly developed in the 21st century. These drugs are tailored to inhibit cancer cell growth, proliferation, and viability by specific interactions with one or a few target proteins. However, despite formally known molecular targets for every “target” drug, patient response to treatment remains largely individual and unpredictable. Choosing the most effective personalized treatment remains a major challenge in oncology and is still largely trial and error. Here we present a novel approach for predicting target drug efficacy based on the gene expression signature of the individual tumor sample(s). The enclosed bioinformatic algorithm detects activation of intracellular regulatory pathways in the tumor in comparison to the corresponding normal tissues. According to the nature of the molecular targets of a drug, it predicts whether the drug can prevent cancer growth and survival in each individual case by blocking the abnormally activated tumor-promoting pathways or by reinforcing internal tumor suppressor cascades. To validate the method, we compared the distribution of predicted drug efficacy scores for five drugs (Sorafenib, Bevacizumab, Cetuximab, Sorafenib, Imatinib, Sunitinib) and seven cancer types (Clear Cell Renal Cell Carcinoma, Colon cancer, Lung adenocarcinoma, non-Hodgkin Lymphoma, Thyroid cancer and Sarcoma) with the available clinical trials data for the respective cancer types and drugs. The percent of responders to a drug treatment correlated significantly (Pearson's correlation 0.77 p = 0.023) with the percent of tumors showing high drug scores calculated with the current algorithm. PMID:26320181

  6. Predictability and Market Efficiency in Agricultural Futures Markets: a Perspective from Price-Volume Correlation Based on Wavelet Coherency Analysis

    NASA Astrophysics Data System (ADS)

    He, Ling-Yun; Wen, Xing-Chun

    2015-12-01

    In this paper, we use a time-frequency domain technique, namely, wavelet squared coherency, to examine the associations between the trading volumes of three agricultural futures and three different forms of these futures' daily closing prices, i.e. prices, returns and volatilities, over the past several years. These agricultural futures markets are selected from China as a typical case of the emerging countries, and from the US as a representative of the developed economies. We investigate correlations and lead-lag relationships between the trading volumes and the prices to detect the predictability and efficiency of these futures markets. The results suggest that the information contained in the trading volumes of the three agricultural futures markets in China can be applied to predict the prices or returns, while that in US has extremely weak predictive power for prices or returns. We also conduct the wavelet analysis on the relationships between the volumes and returns or volatilities to examine the existence of the two "stylized facts" proposed by Karpoff [J. M. Karpoff, The relation between price changes and trading volume: A survey, J. Financ. Quant. Anal.22(1) (1987) 109-126]. Different markets in the two countries perform differently in reproducing the two stylized facts. As the wavelet tools can decode nonlinear regularities and hidden patterns behind price-volume relationship in time-frequency space, different from the conventional econometric framework, this paper offers a new perspective into the market predictability and efficiency.

  7. Efficient visual coding and the predictability of eye movements on natural movies.

    PubMed

    Vig, Eleonora; Dorr, Michael; Barth, Erhardt

    2009-01-01

    We deal with the analysis of eye movements made on natural movies in free-viewing conditions. Saccades are detected and used to label two classes of movie patches as attended and non-attended. Machine learning techniques are then used to determine how well the two classes can be separated, i.e., how predictable saccade targets are. Although very simple saliency measures are used and then averaged to obtain just one average value per scale, the two classes can be separated with an ROC score of around 0.7, which is higher than previously reported results. Moreover, predictability is analysed for different representations to obtain indirect evidence for the likelihood of a particular representation. It is shown that the predictability correlates with the local intrinsic dimension in a movie. PMID:19814903

  8. Background matching and camouflage efficiency predict population density in four-eyed turtle (Sacalia quadriocellata).

    PubMed

    Xiao, Fanrong; Yang, Canchao; Shi, Haitao; Wang, Jichao; Sun, Liang; Lin, Liu

    2016-10-01

    Background matching is an important way to camouflage and is widespread among animals. In the field, however, few studies have addressed background matching, and there has been no reported camouflage efficiency in freshwater turtles. Background matching and camouflage efficiency of the four-eyed turtle, Sacalia quadriocellata, among three microhabitat sections of Hezonggou stream were investigated by measuring carapace components of CIE L*a*b* (International Commission on Illumination; lightness, red/green and yellow/blue) color space, and scoring camouflage efficiency through the use of humans as predators. The results showed that the color difference (ΔE), lightness difference (ΔL(*)), and chroma difference (Δa(*)b(*)) between carapace and the substrate background in midstream were significantly lower than that upstream and downstream, indicating that the four-eyed turtle carapace color most closely matched the substrate of midstream. In line with these findings, the camouflage efficiency was the best for the turtles that inhabit midstream. These results suggest that the four-eyed turtles may enhance camouflage efficiency by selecting microhabitat that best match their carapace color. This finding may explain the high population density of the four-eyed turtle in the midstream section of Hezonggou stream. To the best of our knowledge, this study is among the first to quantify camouflage of freshwater turtles in the wild, laying the groundwork to further study the function and mechanisms of turtle camouflage. PMID:27542920

  9. Background matching and camouflage efficiency predict population density in four-eyed turtle (Sacalia quadriocellata).

    PubMed

    Xiao, Fanrong; Yang, Canchao; Shi, Haitao; Wang, Jichao; Sun, Liang; Lin, Liu

    2016-10-01

    Background matching is an important way to camouflage and is widespread among animals. In the field, however, few studies have addressed background matching, and there has been no reported camouflage efficiency in freshwater turtles. Background matching and camouflage efficiency of the four-eyed turtle, Sacalia quadriocellata, among three microhabitat sections of Hezonggou stream were investigated by measuring carapace components of CIE L*a*b* (International Commission on Illumination; lightness, red/green and yellow/blue) color space, and scoring camouflage efficiency through the use of humans as predators. The results showed that the color difference (ΔE), lightness difference (ΔL(*)), and chroma difference (Δa(*)b(*)) between carapace and the substrate background in midstream were significantly lower than that upstream and downstream, indicating that the four-eyed turtle carapace color most closely matched the substrate of midstream. In line with these findings, the camouflage efficiency was the best for the turtles that inhabit midstream. These results suggest that the four-eyed turtles may enhance camouflage efficiency by selecting microhabitat that best match their carapace color. This finding may explain the high population density of the four-eyed turtle in the midstream section of Hezonggou stream. To the best of our knowledge, this study is among the first to quantify camouflage of freshwater turtles in the wild, laying the groundwork to further study the function and mechanisms of turtle camouflage.

  10. A cascaded QSAR model for efficient prediction of overall power conversion efficiency of all-organic dye-sensitized solar cells.

    PubMed

    Li, Hongzhi; Zhong, Ziyan; Li, Lin; Gao, Rui; Cui, Jingxia; Gao, Ting; Hu, Li Hong; Lu, Yinghua; Su, Zhong-Min; Li, Hui

    2015-05-30

    A cascaded model is proposed to establish the quantitative structure-activity relationship (QSAR) between the overall power conversion efficiency (PCE) and quantum chemical molecular descriptors of all-organic dye sensitizers. The cascaded model is a two-level network in which the outputs of the first level (JSC, VOC, and FF) are the inputs of the second level, and the ultimate end-point is the overall PCE of dye-sensitized solar cells (DSSCs). The model combines quantum chemical methods and machine learning methods, further including quantum chemical calculations, data division, feature selection, regression, and validation steps. To improve the efficiency of the model and reduce the redundancy and noise of the molecular descriptors, six feature selection methods (multiple linear regression, genetic algorithms, mean impact value, forward selection, backward elimination, and +n-m algorithm) are used with the support vector machine. The best established cascaded model predicts the PCE values of DSSCs with a MAE of 0.57 (%), which is about 10% of the mean value PCE (5.62%). The validation parameters according to the OECD principles are R(2) (0.75), Q(2) (0.77), and Qcv2 (0.76), which demonstrate the great goodness-of-fit, predictivity, and robustness of the model. Additionally, the applicability domain of the cascaded QSAR model is defined for further application. This study demonstrates that the established cascaded model is able to effectively predict the PCE for organic dye sensitizers with very low cost and relatively high accuracy, providing a useful tool for the design of dye sensitizers with high PCE.

  11. Efficient network disintegration under incomplete information: the comic effect of link prediction

    NASA Astrophysics Data System (ADS)

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-03-01

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

  12. Efficient network disintegration under incomplete information: the comic effect of link prediction

    PubMed Central

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-01-01

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized. PMID:26960247

  13. Efficient network disintegration under incomplete information: the comic effect of link prediction.

    PubMed

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-03-10

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the "comic effect" of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

  14. Efficient network disintegration under incomplete information: the comic effect of link prediction.

    PubMed

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-01-01

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the "comic effect" of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized. PMID:26960247

  15. Central nervous system penetration-effectiveness rank does not reliably predict neurocognitive impairment in HIV-infected individuals

    PubMed Central

    Libertone, Raffaella; Lorenzini, Patrizia; Balestra, Pietro; Pinnetti, Carmela; Ricottini, Martina; Maddalena Plazzi, Maria; Menichetti, Samanta; Zaccarelli, Mauro; Nicastri, Emanuele; Bellagamba, Rita; Ammassari, Adriana; Antinori, Andrea

    2014-01-01

    Introduction Central nervous system (CNS) penetration-effectiveness (CPE) rank was proposed in 2008 as an estimate of penetration of ARV regimen into the CNS, and validated as predictor of CSF HIV-1 replication. Results on predictive role of CPE on neurocognitive and clinical outcome were conflicting. Materials and Methods Retrospective, cross-sectional analysis of neurocognitive profile in HIV-infected cART-treated patients. All patients underwent neuropsychological (NP) assessment by standardized battery of 14 tests on 5 different domains. People were classified as having NCI if they scored >1 standard deviation (SD) below the normal mean in at least two tests, or >2 SD below in one test. Linear and logistic regression analyses were fitted using as outcome Npz8 and impaired/not impaired respectively. Results A total of 660 HIV-infected cART-treated individuals from 2009 to 2014, contributing a total of 1003 tests (mean age 49 (IQR 43–56), male 82%; median current CD4 586/mm3; 18% HCV infected; HIV-RNA <40 cp/mL in 84%). Current ARV regimen was 2NRTIs+1NNRTI 50.3%, 2NRTI+1PI/r in 32.6%, NRTI sparing in 11.1%. Mean CPE of current regimens was 6.6 (95% CI 6.5–6.7). As per test multivariable analysis, higher CPE values were associated to poor NP tasks (Beta=−0,09; 95% CI −0,14 −0,03; p=0.002 at multivariable linear regression). The association between higher CPE and increased NCI risk was confirmed at multivariable logistic regression, with a 1.24-fold risk of NCI occurrence for each point increase of CPE of current regimen at the time of NP testing (see Table 1). In a sensitivity analysis performed only on patients at the first NP test, the association between higher CPE and poor NP tasks and enhanced NCI risk was only marginally confirmed (Beta=−0,05; [−0,12–0,02]; p=0,19; OR 1,13 [0,95–1,34]; p=0.17). Older age, longer time from HIV diagnosis, current CD4 count <350 cell/mm3 and lower education level were all associated to an increased risk of

  16. Length of sick leave – Why not ask the sick-listed? Sick-listed individuals predict their length of sick leave more accurately than professionals

    PubMed Central

    Fleten, Nils; Johnsen, Roar; Førde, Olav Helge

    2004-01-01

    Background The knowledge of factors accurately predicting the long lasting sick leaves is sparse, but information on medical condition is believed to be necessary to identify persons at risk. Based on the current practice, with identifying sick-listed individuals at risk of long-lasting sick leaves, the objectives of this study were to inquire the diagnostic accuracy of length of sick leaves predicted in the Norwegian National Insurance Offices, and to compare their predictions with the self-predictions of the sick-listed. Methods Based on medical certificates, two National Insurance medical consultants and two National Insurance officers predicted, at day 14, the length of sick leave in 993 consecutive cases of sick leave, resulting from musculoskeletal or mental disorders, in this 1-year follow-up study. Two months later they reassessed 322 cases based on extended medical certificates. Self-predictions were obtained in 152 sick-listed subjects when their sick leave passed 14 days. Diagnostic accuracy of the predictions was analysed by ROC area, sensitivity, specificity, likelihood ratio, and positive predictive value was included in the analyses of predictive validity. Results The sick-listed identified sick leave lasting 12 weeks or longer with an ROC area of 80.9% (95% CI 73.7–86.8), while the corresponding estimates for medical consultants and officers had ROC areas of 55.6% (95% CI 45.6–65.6%) and 56.0% (95% CI 46.6–65.4%), respectively. The predictions of sick-listed males were significantly better than those of female subjects, and older subjects predicted somewhat better than younger subjects. Neither formal medical competence, nor additional medical information, noticeably improved the diagnostic accuracy based on medical certificates. Conclusion This study demonstrates that the accuracy of a prognosis based on medical documentation in sickness absence forms, is lower than that of one based on direct communication with the sick-listed themselves

  17. Efficient CRISPR/Cas9-Mediated Versatile, Predictable, and Donor-Free Gene Knockout in Human Pluripotent Stem Cells.

    PubMed

    Liu, Zhongliang; Hui, Yi; Shi, Lei; Chen, Zhenyu; Xu, Xiangjie; Chi, Liankai; Fan, Beibei; Fang, Yujiang; Liu, Yang; Ma, Lin; Wang, Yiran; Xiao, Lei; Zhang, Quanbin; Jin, Guohua; Liu, Ling; Zhang, Xiaoqing

    2016-09-13

    Loss-of-function studies in human pluripotent stem cells (hPSCs) require efficient methodologies for lesion of genes of interest. Here, we introduce a donor-free paired gRNA-guided CRISPR/Cas9 knockout strategy (paired-KO) for efficient and rapid gene ablation in hPSCs. Through paired-KO, we succeeded in targeting all genes of interest with high biallelic targeting efficiencies. More importantly, during paired-KO, the cleaved DNA was repaired mostly through direct end joining without insertions/deletions (precise ligation), and thus makes the lesion product predictable. The paired-KO remained highly efficient for one-step targeting of multiple genes and was also efficient for targeting of microRNA, while for long non-coding RNA over 8 kb, cleavage of a short fragment of the core promoter region was sufficient to eradicate downstream gene transcription. This work suggests that the paired-KO strategy is a simple and robust system for loss-of-function studies for both coding and non-coding genes in hPSCs. PMID:27594587

  18. New efficient optimizing techniques for Kalman filters and numerical weather prediction models

    NASA Astrophysics Data System (ADS)

    Famelis, Ioannis; Galanis, George; Liakatas, Aristotelis

    2016-06-01

    The need for accurate local environmental predictions and simulations beyond the classical meteorological forecasts are increasing the last years due to the great number of applications that are directly or not affected: renewable energy resource assessment, natural hazards early warning systems, global warming and questions on the climate change can be listed among them. Within this framework the utilization of numerical weather and wave prediction systems in conjunction with advanced statistical techniques that support the elimination of the model bias and the reduction of the error variability may successfully address the above issues. In the present work, new optimization methods are studied and tested in selected areas of Greece where the use of renewable energy sources is of critical. The added value of the proposed work is due to the solid mathematical background adopted making use of Information Geometry and Statistical techniques, new versions of Kalman filters and state of the art numerical analysis tools.

  19. Prediction of a membrane-coupled anaerobic VFA fermenter efficiency using an empirical model.

    PubMed

    Kim, J O; Somiya, I

    2001-03-01

    An empirical model based on some statistical analysis for predicting produced volatile fatty acids (VFA) concentration was developed to establish reliable design conditions of a membrane-coupled anaerobic VFA fermenter (MCAVF) and assess its performance with influent organics concentration (Ci), membrane filtration ratio (phi) and hydraulic loading rate (HLR). The empirical model followed the same trend as the experimental data, which showed the effectiveness of the model. The relationship involving these three independent variables explained more than 90% of the variation in the dependent variable. A model explains that the produced VFA concentration is more sensitive to changes in influent organics concentration (Ci) and membrane filtration ratio (phi) than hydraulic loading rate (HLR). This empirical model can predict the optimum values of operation parameters on many scenarios. Due to its simplicity, the empirical model can be used to design and operate a membrane-coupled anaerobic VFAs fermenter. PMID:11346285

  20. Predicting the oral uptake efficiency of chemicals in mammals: Combining the hydrophilic and lipophilic range

    SciTech Connect

    O'Connor, Isabel A.; Huijbregts, Mark A.J.; Ragas, Ad M.J.; Hendriks, A. Jan

    2013-01-01

    Environmental risk assessment requires models for estimating the bioaccumulation of untested compounds. So far, bioaccumulation models have focused on lipophilic compounds, and only a few have included hydrophilic compounds. Our aim was to extend an existing bioaccumulation model to estimate the oral uptake efficiency of pollutants in mammals for compounds over a wide K{sub ow} range with an emphasis on hydrophilic compounds, i.e. compounds in the lower K{sub ow} range. Usually, most models use octanol as a single surrogate for the membrane and thus neglect the bilayer structure of the membrane. However, compounds with polar groups can have different affinities for the different membrane regions. Therefore, an existing bioaccumulation model was extended by dividing the diffusion resistance through the membrane into an outer and inner membrane resistance, where the solvents octanol and heptane were used as surrogates for these membrane regions, respectively. The model was calibrated with uptake efficiencies of environmental pollutants measured in different mammals during feeding studies combined with human oral uptake efficiencies of pharmaceuticals. The new model estimated the uptake efficiency of neutral (RMSE = 14.6) and dissociating (RMSE = 19.5) compounds with logK{sub ow} ranging from − 10 to + 8. The inclusion of the K{sub hw} improved uptake estimation for 33% of the hydrophilic compounds (logK{sub ow} < 0) (r{sup 2} = 0.51, RMSE = 22.8) compared with the model based on K{sub ow} only (r{sup 2} = 0.05, RMSE = 34.9), while hydrophobic compounds (logK{sub ow} > 0) were estimated equally by both model versions with RMSE = 15.2 (K{sub ow} and K{sub hw}) and RMSE = 15.7 (K{sub ow} only). The model can be used to estimate the oral uptake efficiency for both hydrophilic and hydrophobic compounds. -- Highlights: ► A mechanistic model was developed to estimate oral uptake efficiency. ► Model covers wide logK{sub ow} range (- 10 to + 8) and several mammalian

  1. Efficiency of genomic prediction for boar taint reduction in Danish Landrace pigs.

    PubMed

    Lukić, B; Pong-Wong, R; Rowe, S J; de Koning, D J; Velander, I; Haley, C S; Archibald, A L; Woolliams, J A

    2015-12-01

    Genetic selection against boar taint, which is caused by high skatole and androstenone concentrations in fat, is a more acceptable alternative than is the current practice of castration. Genomic predictors offer an opportunity to overcome the limitations of such selection caused by the phenotype being expressed only in males at slaughter, and this study evaluated different approaches to obtain such predictors. Samples from 1000 pigs were included in a design which was dominated by 421 sib pairs, each pair having one animal with high and one with low skatole concentration (≥0.3 μg/g). All samples were measured for both skatole and androstenone and genotyped using the Illumina SNP60 porcine BeadChip for 62 153 single nucleotide polymorphisms. The accuracy of predicting phenotypes was assessed by cross-validation using six different genomic evaluation methods: genomic best linear unbiased prediction (GBLUP) and five Bayesian regression methods. In addition, this was compared to the accuracy of predictions using only QTL that showed genome-wide significance. The range of accuracies obtained by different prediction methods was narrow for androstenone, between 0.29 (Bayes Lasso) and 0.31 (Bayes B), and wider for skatole, between 0.21 (GBLUP) and 0.26 (Bayes SSVS). Relative accuracies, corrected for h(2) , were 0.54-0.56 and 0.75-0.94 for androstenone and skatole respectively. The whole-genome evaluation methods gave greater accuracy than using only the QTL detected in the data. The results demonstrate that GBLUP for androstenone is the simplest genomic technology to implement and was also close to the most accurate method. More specialised models may be preferable for skatole. PMID:26449733

  2. A coupled kinematics-energetics model for predicting energy efficient flapping flight.

    PubMed

    Salehipour, Hesam; Willis, David J

    2013-02-01

    A new computational model based on an optimal power, wake-only aerodynamics method is presented to predict the interdependency of energetics and kinematics in bird and bat flight. The model is divided into offline, intermediate and online modules. In the offline module, a four-dimensional design space sweep is performed (lift, thrust, flapping amplitude and flapping frequency). In the intermediate stage, the physical characteristics of the animal are introduced (wing span, mass, wing area, aspect ratio, etc.), and a series of amplitude-frequency response surfaces are constructed for all viable flight speeds. In the online component, the amplitude-frequency response surfaces are mined for the specific flapping motions being considered. The method is applied to several biological examples including a medium sized fruit bat (Cynopterus brachyotis), and two birds: a thrush nightingale (Luscinia luscinia) and a budgerigar (Melopsittacus undulatus). For each of these animals, the power and kinematics predictions are compared with available experimental data. These examples demonstrate that this new method can reasonably predict animal flight energetics and kinematics. PMID:23084891

  3. An efficient and robust method for predicting helicopter rotor high-speed impulsive noise

    NASA Technical Reports Server (NTRS)

    Brentner, Kenneth S.

    1996-01-01

    A new formulation for the Ffowcs Williams-Hawkings quadrupole source, which is valid for a far-field in-plane observer, is presented. The far-field approximation is new and unique in that no further approximation of the quadrupole source strength is made and integrands with r(exp -2) and r(exp -3) dependence are retained. This paper focuses on the development of a retarded-time formulation in which time derivatives are analytically taken inside the integrals to avoid unnecessary computational work when the observer moves with the rotor. The new quadrupole formulation is similar to Farassat's thickness and loading formulation 1A. Quadrupole noise prediction is carried out in two parts: a preprocessing stage in which the previously computed flow field is integrated in the direction normal to the rotor disk, and a noise computation stage in which quadrupole surface integrals are evaluated for a particular observer position. Preliminary predictions for hover and forward flight agree well with experimental data. The method is robust and requires computer resources comparable to thickness and loading noise prediction.

  4. Efficient Inverse Isoparametric Mapping Algorithm for Whole-Body Computed Tomography Registration Using Deformations Predicted by Nonlinear Finite Element Modeling

    PubMed Central

    Li, Mao; Wittek, Adam; Miller, Karol

    2014-01-01

    Biomechanical modeling methods can be used to predict deformations for medical image registration and particularly, they are very effective for whole-body computed tomography (CT) image registration because differences between the source and target images caused by complex articulated motions and soft tissues deformations are very large. The biomechanics-based image registration method needs to deform the source images using the deformation field predicted by finite element models (FEMs). In practice, the global and local coordinate systems are used in finite element analysis. This involves the transformation of coordinates from the global coordinate system to the local coordinate system when calculating the global coordinates of image voxels for warping images. In this paper, we present an efficient numerical inverse isoparametric mapping algorithm to calculate the local coordinates of arbitrary points within the eight-noded hexahedral finite element. Verification of the algorithm for a nonparallelepiped hexahedral element confirms its accuracy, fast convergence, and efficiency. The algorithm's application in warping of the whole-body CT using the deformation field predicted by means of a biomechanical FEM confirms its reliability in the context of whole-body CT registration. PMID:24828796

  5. Correlation to Predict Collision Efficiency of Natural Organic Matter (NOM)- and Polymer- coated Nanoparticles in Porous Media

    NASA Astrophysics Data System (ADS)

    Lowry, G. V.; Phenrat, T.; Cisneros, C. M.; Schoenfelder, D. P.; Fagerlund, F.; Kim, H.; Illangasekare, T.; Tilton, R. D.

    2008-12-01

    The fate of manufactured nanoparticles released to the environment is of great interest due to their increasing use in consumer products and their potential risk to the environment and human health. Manufactured nanomaterials typically have a polymeric surface coating to provide specific functionality, or will adsorb natural organic matter (NOM) once released into the environment. Adsorbed polymer and NOM can provide electrosteic repulsions that enhance the migration of nanoparticles in porous media. Semi-empirical correlations to predict the collision efficiency of electrostatically stabilized (uncoated) colloids are available, however, they are not applicable to nanomaterials coated with polymeric or NOM layers. We present a semi- empirical correlation to predict the collision efficiency of NOM and polymer-coated nanomaterials in saturated porous media. The adsorbed mass and adsorbed layer properties (including thickness) are determined and particle breakthrough curves are generated for a number of particle and coating types. Regression analysis is then used to develop a semi-empirical correlation that includes a parameter (NLEK) representing electrosteric repulsions afforded by adsorbed NOM or polymer. The correlation appears robust over a range of four particle and four coating types and should be a valuable tool for predicting the relative mobility of different manufactured and natural nanomaterials based on a few measurable properties.

  6. Backbone dependency further improves side chain prediction efficiency in the Energy-based Conformer Library (bEBL).

    PubMed

    Subramaniam, Sabareesh; Senes, Alessandro

    2014-11-01

    Side chain optimization is an integral component of many protein modeling applications. In these applications, the conformational freedom of the side chains is often explored using libraries of discrete, frequently occurring conformations. Because side chain optimization can pose a computationally intensive combinatorial problem, the nature of these conformer libraries is important for ensuring efficiency and accuracy in side chain prediction. We have previously developed an innovative method to create a conformer library with enhanced performance. The Energy-based Library (EBL) was obtained by analyzing the energetic interactions between conformers and a large number of natural protein environments from crystal structures. This process guided the selection of conformers with the highest propensity to fit into spaces that should accommodate a side chain. Because the method requires a large crystallographic data-set, the EBL was created in a backbone-independent fashion. However, it is well established that side chain conformation is strongly dependent on the local backbone geometry, and that backbone-dependent libraries are more efficient in side chain optimization. Here we present the backbone-dependent EBL (bEBL), whose conformers are independently sorted for each populated region of Ramachandran space. The resulting library closely mirrors the local backbone-dependent distribution of side chain conformation. Compared to the EBL, we demonstrate that the bEBL uses fewer conformers to produce similar side chain