Effect of Early ≤ 3 Mets (Metabolic Equivalent of Tasks) of Physical Activity on Patient's Outcome after Cardiac Surgery.

PubMed

Tariq, Muhammad Iqbal; Khan, Asif Ali; Khalid, Zara; Farheen, Hania; Siddiqi, Furqan Ahmed; Amjad, Imran

2017-08-01

To determine the effect of <3 Mets (Metabolic Equivalent of Tasks) of physical activity on zero postoperative days for improving hemodynamic and respiratory parameters of patients after cardiac surgeries. Randomized control trial. BARMWTHospital, Rawalpindi, from March to August 2015. Arandomized controlled trial was conducted on 174 CABG and valvular heart disease patients undergoing cardiac surgical procedures. After selection of sample via non-probability purposive sampling, they were randomly allocated into interventional group (n=87) and control group (n=87). Treatment protocol for experimental group was ≤3 Mets of physical activity, i.e. chest physiotherapy, sitting over edge of bed, standing and sitting on chair at bedside, on zero postoperative day but the control group was treated with conventional treatment on first postoperative day. Pre- and post-treatment assessment was done in control and interventional groups on both zero and first postoperative days. Data was analyzed on SPSS version 21. The patients' mean age was 51.86 ±13.76 years. Male to female ratio was 132:42. Statistically significant differences in respiratory rate and SpO2 (p=0.000 and 0.000, respectively) were found between both groups. Among ABG's, PCO2 and pH showed significant differences with p values of 0.039 and <0.001, respectively. No significant differences were observed between both groups regarding electrolytes (Na+, K+, Cl-, p-values of 0.361, 0.575 and 0.120 respectively) and creatinine (p=0.783). Marked improvement in oxygen saturation, dyspnea and a fall in systolic BPwas seen in interventional group. There was also observed to be a reduction in the length of ICU stay among interventional group patients as frequency with percentage of total stay was compared to control group. Early physical activity (≤3 METS) post-cardiac surgeries prevent respiratory complications through improvement in dyspnea, respiratory rate, and oxygen saturation.

Change in Physical Activity and Sitting Time After Myocardial Infarction and Mortality Among Postmenopausal Women in the Women's Health Initiative-Observational Study.

PubMed

Gorczyca, Anna M; Eaton, Charles B; LaMonte, Michael J; Manson, JoAnn E; Johnston, Jeanne D; Bidulescu, Aurelian; Waring, Molly E; Manini, Todd; Martin, Lisa W; Stefanick, Marcia L; He, Ka; Chomistek, Andrea K

2017-05-15

How physical activity (PA) and sitting time may change after first myocardial infarction (MI) and the association with mortality in postmenopausal women is unknown. Participants included postmenopausal women in the Women's Health Initiative-Observational Study, aged 50 to 79 years who experienced a clinical MI during the study. This analysis included 856 women who had adequate data on PA exposure and 533 women for sitting time exposures. Sitting time was self-reported at baseline, year 3, and year 6. Self-reported PA was reported at baseline through year 8. Change in PA and sitting time were calculated as the difference between the cumulative average immediately following MI and the cumulative average immediately preceding MI. The 4 categories of change were: maintained low, decreased, increased, and maintained high. The cut points were ≥7.5 metabolic equivalent of task hours/week versus <7.5 metabolic equivalent of task hours/week for PA and ≥8 h/day versus <8 h/day for sitting time. Cox proportional hazard models estimated hazard ratios and 95% CIs for all-cause, coronary heart disease, and cardiovascular disease mortality. Compared with women who maintained low PA (referent), the risk of all-cause mortality was: 0.54 (0.34-0.86) for increased PA and 0.52 (0.36-0.73) for maintained high PA. Women who had pre-MI levels of sitting time <8 h/day, every 1 h/day increase in sitting time was associated with a 9% increased risk (hazard ratio=1.09, 95% CI: 1.01, 1.19) of all-cause mortality. Meeting the recommended PA guidelines pre- and post-MI may have a protective role against mortality in postmenopausal women. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Maximal exercise testing variables and 10-year survival: fitness risk score derivation from the FIT Project.

PubMed

Ahmed, Haitham M; Al-Mallah, Mouaz H; McEvoy, John W; Nasir, Khurram; Blumenthal, Roger S; Jones, Steven R; Brawner, Clinton A; Keteyian, Steven J; Blaha, Michael J

2015-03-01

To determine which routinely collected exercise test variables most strongly correlate with survival and to derive a fitness risk score that can be used to predict 10-year survival. This was a retrospective cohort study of 58,020 adults aged 18 to 96 years who were free of established heart disease and were referred for an exercise stress test from January 1, 1991, through May 31, 2009. Demographic, clinical, exercise, and mortality data were collected on all patients as part of the Henry Ford ExercIse Testing (FIT) Project. Cox proportional hazards models were used to identify exercise test variables most predictive of survival. A "FIT Treadmill Score" was then derived from the β coefficients of the model with the highest survival discrimination. The median age of the 58,020 participants was 53 years (interquartile range, 45-62 years), and 28,201 (49%) were female. Over a median of 10 years (interquartile range, 8-14 years), 6456 patients (11%) died. After age and sex, peak metabolic equivalents of task and percentage of maximum predicted heart rate achieved were most highly predictive of survival (P<.001). Subsequent addition of baseline blood pressure and heart rate, change in vital signs, double product, and risk factor data did not further improve survival discrimination. The FIT Treadmill Score, calculated as [percentage of maximum predicted heart rate + 12(metabolic equivalents of task) - 4(age) + 43 if female], ranged from -200 to 200 across the cohort, was near normally distributed, and was found to be highly predictive of 10-year survival (Harrell C statistic, 0.811). The FIT Treadmill Score is easily attainable from any standard exercise test and translates basic treadmill performance measures into a fitness-related mortality risk score. The FIT Treadmill Score should be validated in external populations. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Partitioning the Metabolic Cost of Human Running: A Task-by-Task Approach

PubMed Central

Arellano, Christopher J.; Kram, Rodger

2014-01-01

Compared with other species, humans can be very tractable and thus an ideal “model system” for investigating the metabolic cost of locomotion. Here, we review the biomechanical basis for the metabolic cost of running. Running has been historically modeled as a simple spring-mass system whereby the leg acts as a linear spring, storing, and returning elastic potential energy during stance. However, if running can be modeled as a simple spring-mass system with the underlying assumption of perfect elastic energy storage and return, why does running incur a metabolic cost at all? In 1980, Taylor et al. proposed the “cost of generating force” hypothesis, which was based on the idea that elastic structures allow the muscles to transform metabolic energy into force, and not necessarily mechanical work. In 1990, Kram and Taylor then provided a more explicit and quantitative explanation by demonstrating that the rate of metabolic energy consumption is proportional to body weight and inversely proportional to the time of foot-ground contact for a variety of animals ranging in size and running speed. With a focus on humans, Kram and his colleagues then adopted a task-by-task approach and initially found that the metabolic cost of running could be “individually” partitioned into body weight support (74%), propulsion (37%), and leg-swing (20%). Summing all these biomechanical tasks leads to a paradoxical overestimation of 131%. To further elucidate the possible interactions between these tasks, later studies quantified the reductions in metabolic cost in response to synergistic combinations of body weight support, aiding horizontal forces, and leg-swing-assist forces. This synergistic approach revealed that the interactive nature of body weight support and forward propulsion comprises ∼80% of the net metabolic cost of running. The task of leg-swing at most comprises ∼7% of the net metabolic cost of running and is independent of body weight support and forward propulsion. In our recent experiments, we have continued to refine this task-by-task approach, demonstrating that maintaining lateral balance comprises only 2% of the net metabolic cost of running. In contrast, arm-swing reduces the cost by ∼3%, indicating a net metabolic benefit. Thus, by considering the synergistic nature of body weight support and forward propulsion, as well as the tasks of leg-swing and lateral balance, we can account for 89% of the net metabolic cost of human running. PMID:24838747

Partitioning the metabolic cost of human running: a task-by-task approach.

PubMed

Arellano, Christopher J; Kram, Rodger

2014-12-01

Compared with other species, humans can be very tractable and thus an ideal "model system" for investigating the metabolic cost of locomotion. Here, we review the biomechanical basis for the metabolic cost of running. Running has been historically modeled as a simple spring-mass system whereby the leg acts as a linear spring, storing, and returning elastic potential energy during stance. However, if running can be modeled as a simple spring-mass system with the underlying assumption of perfect elastic energy storage and return, why does running incur a metabolic cost at all? In 1980, Taylor et al. proposed the "cost of generating force" hypothesis, which was based on the idea that elastic structures allow the muscles to transform metabolic energy into force, and not necessarily mechanical work. In 1990, Kram and Taylor then provided a more explicit and quantitative explanation by demonstrating that the rate of metabolic energy consumption is proportional to body weight and inversely proportional to the time of foot-ground contact for a variety of animals ranging in size and running speed. With a focus on humans, Kram and his colleagues then adopted a task-by-task approach and initially found that the metabolic cost of running could be "individually" partitioned into body weight support (74%), propulsion (37%), and leg-swing (20%). Summing all these biomechanical tasks leads to a paradoxical overestimation of 131%. To further elucidate the possible interactions between these tasks, later studies quantified the reductions in metabolic cost in response to synergistic combinations of body weight support, aiding horizontal forces, and leg-swing-assist forces. This synergistic approach revealed that the interactive nature of body weight support and forward propulsion comprises ∼80% of the net metabolic cost of running. The task of leg-swing at most comprises ∼7% of the net metabolic cost of running and is independent of body weight support and forward propulsion. In our recent experiments, we have continued to refine this task-by-task approach, demonstrating that maintaining lateral balance comprises only 2% of the net metabolic cost of running. In contrast, arm-swing reduces the cost by ∼3%, indicating a net metabolic benefit. Thus, by considering the synergistic nature of body weight support and forward propulsion, as well as the tasks of leg-swing and lateral balance, we can account for 89% of the net metabolic cost of human running. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Redox-shuttling between chloroplast and cytosol: integration of intra-chloroplast and extra-chloroplast metabolism.

PubMed

Taniguchi, Mitsutaka; Miyake, Hiroshi

2012-06-01

Reducing equivalents produced in the chloroplast are essential for many key cellular metabolic enzyme reactions. Two redox shuttle systems transfer reductant out of the chloroplast; these systems consist of metabolite transporters, coupled with stromal and cytosolic dehydrogenase isozymes. The transporters function in the redox shuttle and also operate as key enzymes in carbon/nitrogen metabolism. To maintain adequate levels of reductant and proper metabolic balance, the shuttle systems are finely controlled. Also, in the leaves of C(4) plants, cell-specific division of carbon and nitrogen assimilation includes cell-specific localization of the redox shuttle systems. The redox shuttle systems are tightly linked to cellular metabolic pathways and are essential for maintaining metabolic balance between energy and reducing equivalents. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cortical activity predicts good variation in human motor output.

PubMed

Babikian, Sarine; Kanso, Eva; Kutch, Jason J

2017-04-01

Human movement patterns have been shown to be particularly variable if many combinations of activity in different muscles all achieve the same task goal (i.e., are goal-equivalent). The nervous system appears to automatically vary its output among goal-equivalent combinations of muscle activity to minimize muscle fatigue or distribute tissue loading, but the neural mechanism of this "good" variation is unknown. Here we use a bimanual finger task, electroencephalography (EEG), and machine learning to determine if cortical signals can predict goal-equivalent variation in finger force output. 18 healthy participants applied left and right index finger forces to repeatedly perform a task that involved matching a total (sum of right and left) finger force. As in previous studies, we observed significantly more variability in goal-equivalent muscle activity across task repetitions compared to variability in muscle activity that would not achieve the goal: participants achieved the task in some repetitions with more right finger force and less left finger force (right > left) and in other repetitions with less right finger force and more left finger force (left > right). We found that EEG signals from the 500 milliseconds (ms) prior to each task repetition could make a significant prediction of which repetitions would have right > left and which would have left > right. We also found that cortical maps of sites contributing to the prediction contain both motor and pre-motor representation in the appropriate hemisphere. Thus, goal-equivalent variation in motor output may be implemented at a cortical level.

Whatever Gave You That Idea? False Memories Following Equivalence Training: A Behavioral Account of the Misinformation Effect

PubMed Central

Challies, Danna M; Hunt, Maree; Garry, Maryanne; Harper, David N

2011-01-01

The misinformation effect is a term used in the cognitive psychological literature to describe both experimental and real-world instances in which misleading information is incorporated into an account of an historical event. In many real-world situations, it is not possible to identify a distinct source of misinformation, and it appears that the witness may have inferred a false memory by integrating information from a variety of sources. In a stimulus equivalence task, a small number of trained relations between some members of a class of arbitrary stimuli result in a large number of untrained, or emergent relations, between all members of the class. Misleading information was introduced into a simple memory task between a learning phase and a recognition test by means of a match-to-sample stimulus equivalence task that included both stimuli from the original learning task and novel stimuli. At the recognition test, participants given equivalence training were more likely to misidentify patterns than those who were not given such training. The misinformation effect was distinct from the effects of prior stimulus exposure, or partial stimulus control. In summary, stimulus equivalence processes may underlie some real-world manifestations of the misinformation effect. PMID:22084495

Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury.

PubMed

Evans, Nicholas; Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

2015-01-01

Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity.

Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury

PubMed Central

Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

2015-01-01

Background: Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. Objective: The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Methods: Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Results: Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Conclusion: Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity. PMID:26364281

Motor equivalence during multi-finger accurate force production

PubMed Central

Mattos, Daniela; Schöner, Gregor; Zatsiorsky, Vladimir M.; Latash, Mark L.

2014-01-01

We explored stability of multi-finger cyclical accurate force production action by analysis of responses to small perturbations applied to one of the fingers and inter-cycle analysis of variance. Healthy subjects performed two versions of the cyclical task, with and without an explicit target. The “inverse piano” apparatus was used to lift/lower a finger by 1 cm over 0.5 s; the subjects were always instructed to perform the task as accurate as they could at all times. Deviations in the spaces of finger forces and modes (hypothetical commands to individual fingers) were quantified in directions that did not change total force (motor equivalent) and in directions that changed the total force (non-motor equivalent). Motor equivalent deviations started immediately with the perturbation and increased progressively with time. After a sequence of lifting-lowering perturbations leading to the initial conditions, motor equivalent deviations were dominating. These phenomena were less pronounced for analysis performed with respect to the total moment of force with respect to an axis parallel to the forearm/hand. Analysis of inter-cycle variance showed consistently higher variance in a subspace that did not change the total force as compared to the variance that affected total force. We interpret the results as reflections of task-specific stability of the redundant multi-finger system. Large motor equivalent deviations suggest that reactions of the neuromotor system to a perturbation involve large changes of neural commands that do not affect salient performance variables, even during actions with the purpose to correct those salient variables. Consistency of the analyses of motor equivalence and variance analysis provides additional support for the idea of task-specific stability ensured at a neural level. PMID:25344311

A formal and data-based comparison of measures of motor-equivalent covariation.

PubMed

Verrel, Julius

2011-09-15

Different analysis methods have been developed for assessing motor-equivalent organization of movement variability. In the uncontrolled manifold (UCM) method, the structure of variability is analyzed by comparing goal-equivalent and non-goal-equivalent variability components at the level of elemental variables (e.g., joint angles). In contrast, in the covariation by randomization (CR) approach, motor-equivalent organization is assessed by comparing variability at the task level between empirical and decorrelated surrogate data. UCM effects can be due to both covariation among elemental variables and selective channeling of variability to elemental variables with low task sensitivity ("individual variation"), suggesting a link between the UCM and CR method. However, the precise relationship between the notion of covariation in the two approaches has not been analyzed in detail yet. Analysis of empirical and simulated data from a study on manual pointing shows that in general the two approaches are not equivalent, but the respective covariation measures are highly correlated (ρ > 0.7) for two proposed definitions of covariation in the UCM context. For one-dimensional task spaces, a formal comparison is possible and in fact the two notions of covariation are equivalent. In situations in which individual variation does not contribute to UCM effects, for which necessary and sufficient conditions are derived, this entails the equivalence of the UCM and CR analysis. Implications for the interpretation of UCM effects are discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Estrogens, Microtubules and Aneuploidy: Mechanisms of Mammary Gland Tumorigenesis.

DTIC Science & Technology

1999-07-01

Endocrinology 136: 1718-1730. STATEMENT OF WORK Aim 1. Task 1. Establish radiometric HPLC assay for estradiol (E2) metabolism Task 2. Establish radiometric... HPLC assay for 7,12- dimethylbenz[a]anthracene (DMBA) metabolism Task 3. Characterize E2 metabolism in ACI and Sprague-Dawley (SD) rat liver...epigallocatechin gallate (EGCG) are flavonoids which have potent chemopreventive activity in a vari- ety of animal models of cancer. One proposed

Delay Choice vs. Delay Maintenance: Different Measures of Delayed Gratification in Capuchin Monkeys (Cebus apella)

PubMed Central

Addessi, Elsa; Paglieri, Fabio; Beran, Michael J.; Evans, Theodore A.; Macchitella, Luigi; De Petrillo, Francesca; Focaroli, Valentina

2013-01-01

Delaying gratification involves two components: (i) delay choice (selecting a delayed reward over an immediate one), and (ii) delay maintenance (sustaining the decision to delay gratification even if the immediate reward is available during the delay). In primates, two tasks most commonly have explored these components, the Intertemporal choice task and the Accumulation task. It is unclear whether these tasks provide equivalent measures of delay of gratification. Here, we compared the performance of the same capuchin monkeys, belonging to two study populations, between these tasks. We found only limited evidence of a significant correlation in performance. Consequently, in contrast to what is often assumed, our data provide only partial support to the hypothesis that these tasks provide equivalent measures of delay of gratification. PMID:23544770

Inductive Reasoning in Zambia, Turkey, and the Netherlands Establishing Cross-Cultural Equivalence.

ERIC Educational Resources Information Center

van de Vijver, Fons J. R.

2002-01-01

Administered tasks of inductive reasoning to 704 Zambian, 877 Turkish, and 632 Dutch students from the highest 2 grades of primary and the lowest 2 grades of secondary school. Results show strong evidence for structural equivalence and partial evidence for measurement unit equivalence, but did not support full score equivalence. (SLD)

Translation and cross-cultural adaptation of the Detailed Assessment of Speed of Handwriting 17+ to Brazilian Portuguese: conceptual, item and semantic equivalence.

PubMed

Cardoso, Monique Herrera; Capellini, Simone Aparecida

2018-02-19

Perform a cross-cultural adaptation of the Detailed Assessment of Speed of Handwriting 17+ (DASH 17+) for Brazilians. Evaluation of (1) conceptual, item and (2) semantic equivalence, with assistance of four translators and application of a pilot study to 36 students. (1) The concepts and items are equivalent in the British and Brazilian cultures. (2) Adaptations were made concerning the English language pangram used in copying tasks and selection of the lower-case, cursive handwriting in the alphabet-writing task. Application of the pilot study verified acceptability and understanding of the proposed tasks by the students. The Brazilian Portuguese version of the DASH 17+ was presented after finalization of the conceptual, item and semantic equivalence of the instrument. Further studies on psychometric properties should be conducted with the purpose of measuring the speed of handwriting in youngsters and adults with greater reliability and validity to the procedure.

Contribution of underlying processes to improved visuospatial working memory associated with physical activity.

PubMed

Ji, Qingchun; Wang, Yingying; Guo, Wei; Zhou, Chenglin

2017-01-01

Working memory is critical for various cognitive processes and can be separated into two stages: short-term memory storage and manipulation processing. Although previous studies have demonstrated that increased physical activity (PA) improves working memory and that males outperform females on visuospatial working memory tasks, few studies have determined the contribution of the two underlying stages to the visuospatial working memory improvement associated with PA. Thus, the aims of the present study were to verify the relationship between physical activity and visuospatial working memory, determine whether one or both stages were affected by PA, and investigate any sex differences. A total of 56 undergraduate students were recruited for this study. Their scores on the International Physical Activity Questionnaire (IPAQ) were used to separate them into either a lower PA ( n  = 26; IPAQ score ≤3,000 metabolic equivalent [MET]-min/week) or higher PA ( n  = 30; IPAQ score >3,000 MET-min/week) group. Participants were required to complete three tasks: a visuospatial working memory task, a task that examines the short-term memory storage stage, and a mental rotation task that examines the active manipulation stage. Participants in the higher PA group maintained similar accuracy but displayed significantly faster reaction times (RT) than those in the lower PA group on the visuospatial working memory and manipulation tasks. By contrast, no difference was observed between groups on the short-term memory storage task. In addition, no effects of sex were detected. Our results confirm that PA was positively to visuospatial working memory and that this positive relationship was associated with more rapid cognitive processing during the manipulation stage, with little or no relationship between PA and the memory storage stage of visuospatial working memory.

Economic decision-making compared with an equivalent motor task.

PubMed

Wu, Shih-Wei; Delgado, Mauricio R; Maloney, Laurence T

2009-04-14

There is considerable evidence that human economic decision-making deviates from the predictions of expected utility theory (EUT) and that human performance conforms to EUT in many perceptual and motor decision tasks. It is possible that these results reflect a real difference in decision-making in the 2 domains but it is also possible that the observed discrepancy simply reflects typical differences in experimental design. We developed a motor task that is mathematically equivalent to choosing between lotteries and used it to compare how the same subject chose between classical economic lotteries and the same lotteries presented in equivalent motor form. In experiment 1, we found that subjects are more risk seeking in deciding between motor lotteries. In experiment 2, we used cumulative prospect theory to model choice and separately estimated the probability weighting functions and the value functions for each subject carrying out each task. We found no patterned differences in how subjects represented outcome value in the motor and the classical tasks. However, the probability weighting functions for motor and classical tasks were markedly and significantly different. Those for the classical task showed a typical tendency to overweight small probabilities and underweight large probabilities, and those for the motor task showed the opposite pattern of probability distortion. This outcome also accounts for the increased risk-seeking observed in the motor tasks of experiment 1. We conclude that the same subject distorts probability, but not value, differently in making identical decisions in motor and classical form.

Metabolic changes in transgenic maize mature seeds over-expressing the Aspergillus niger phyA2.

PubMed

Rao, Jun; Yang, Litao; Guo, Jinchao; Quan, Sheng; Chen, Guihua; Zhao, Xiangxiang; Zhang, Dabing; Shi, Jianxin

2016-02-01

Non-targeted metabolomics analysis revealed only intended metabolic changes in transgenic maize over-expressing the Aspergillus niger phyA2. Genetically modified (GM) crops account for a large proportion of modern agriculture worldwide, raising increasingly the public concerns of safety. Generally, according to substantial equivalence principle, if a GM crop is demonstrated to be equivalently safe to its conventional species, it is supposed to be safe. In this study, taking the advantage of an established non-target metabolomic profiling platform based on the combination of UPLC-MS/MS with GC-MS, we compared the mature seed metabolic changes in transgenic maize over-expressing the Aspergillus niger phyA2 with its non-transgenic counterpart and other 14 conventional maize lines. In total, levels of nine out of identified 210 metabolites were significantly changed in transgenic maize as compared with its non-transgenic counterpart, and the number of significantly altered metabolites was reduced to only four when the natural variations were taken into consideration. Notably, those four metabolites were all associated with targeted engineering pathway. Our results indicated that although both intended and non-intended metabolic changes occurred in the mature seeds of this GM maize event, only intended metabolic pathway was found to be out of the range of the natural metabolic variation in the metabolome of the transgenic maize. Therefore, only when natural metabolic variation was taken into account, could non-targeted metabolomics provide reliable objective compositional substantial equivalence analysis on GM crops.

Equivalence-Equivalence: Matching Stimuli with Same Discriminative Functions

ERIC Educational Resources Information Center

Carpentier, Franck; Smeets, Paul M.; Barnes-Holmes, Dermot

2004-01-01

Previous studies have shown that after being trained on A-B and A-C match-to-sample tasks, adults match not only same-class B and C stimuli (equivalence) but also BC compounds with same-class elements and with different-class elements (BC-BC). The assumption was that the BC-BC performances are based on matching equivalence and nonequivalence…

Energy metabolism during activity-promoting video games practice in subjects with spinal cord injury: evidences for health promotion.

PubMed

Gaffurini, P; Bissolotti, L; Calza, S; Calabretto, C; Orizio, C; Gobbo, M

2013-02-01

Activity promoting video game (APVG) practice significantly affects energy metabolism through energy expenditure (EE) increase and has been recently included in strategies for health promotion. It is not known if the APVG practice provides similar outcomes in subjects with spinal cord injury (SCI). Aim of the study was to evaluate cardio-pulmonary and metabolic adaptations during APVG practice and to find whether EE increase above resting condition could suggest the inclusion of this exercise in a more general strategy for health promotion and body weight control in subjects with SCI. Repeated measures study. Rehabilitation Institute. Ten male subjects with SCI (lesion levels from C7 to L1) age 26 to 55 years. We recorded pulmonary ventilation (VE), oxygen consumption (VO2) for EE esteem and heart rate (HR) at rest and while playing virtual bowling, tennis and boxing games using a portable metabolimeter equipped with ECG electrodes. The standard metabolic equivalent of task (METs) was calculated offline. The metabolic and functional parameters were referred to the 10th minute of each activity. Metabolic and functional parameters increased significantly from rest to bowling, tennis and boxing. METs exceeded in average 3 during boxing. One hour of APVG can increase daily EE by about 6% (bowling), 10% (tennis) and 15% (boxing). These considerable results suggest that physical exertion during APVG practice in subjects with SCI could contribute to health promotion as well as caloric balance control, especially when boxing is considered. This can be safely achieved at home with regular activity. These findings substantiate the potential for novel exercise modalities to counteract deconditioning due to inactivity in subjects with SCI by promoting physical activity through implementation of APVG exercise programs.

Selected Metabolic Responses to Skateboarding

ERIC Educational Resources Information Center

Hetzler, Ronald K.; Hunt, Ian; Stickley, Christopher D.; Kimura, Iris F.

2011-01-01

Despite the popularity of skateboarding worldwide, the authors believe that no previous studies have investigated the metabolic demands associated with recreational participation in the sport. Although metabolic equivalents (METs) for skateboarding were published in textbooks, the source of these values is unclear. Therefore, the rise in…

Association of Exercise and Metabolic Equivalent of Task (MET) Score with Survival Outcomes after Out-of-Hospital Cardiac Arrest of Young and Middle Age.

PubMed

Ro, Young Sun; Shin, Sang Do; Song, Kyoung Jun; Hong, Ki Jeong; Ahn, Ki Ok

2017-06-01

Regular physical activity is recommended to prevent cardiovascular disease including out-of-hospital cardiac arrest (OHCA). However, it is uncertain whether the intensity during physical activity is associated with better outcomes. We studied the effect of exercise at the time of arrest and the association between metabolic equivalent of task (MET) score and survival of OHCA patients of young and middle age. All OHCAs of presumed cardiac etiology who were 18-65 years of age and were witnessed by a layperson between 2013 and 2015 were analyzed. The main exposure of interest was physical activity at the time of, or immediately prior to, the arrest and the MET score groups (0-3 for light, 3-6 for moderate, and ≥6 for vigorous). The endpoint was survival with good neurological recovery. For the sensitivity analysis, we created a matched dataset by matching for age, gender, residential area, and comorbidities (diabetes, hypertension, heart disease, and stroke). Multivariable logistic regression analysis was performed, adjusting for patient and arrest-environmental factors. A total of 6,273 patients in the original dataset were included, and 762 (12.1%) patients had a cardiac arrest during exercise. The exercise-related OHCAs were more likely to have a good neurological recovery rate (25.9%) than the non-exercise-related OHCA (12.9%) in the original dataset (AOR (95% CI): 1.36 (1.08-1.70)) but not in the matched dataset (1.37 (0.92-1.97)). Using MET score groups, the moderate-intensity group compared with the non-exercise group was associated with better neurological outcome (1.70 (1.11-2.63)), but neither light-intensity (0.77 (0.40-1.49)) nor vigorous-intensity (1.44 (0.91-2.28)) groups were associated with better outcomes. Patients who had an OHCA during exercise were more likely to have neurologically intact survival compared to patients who had an OHCA during periods of non-exercise; however, only the moderate-intensity group was associated with a better neurological outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of the metabolic rate based on the recording of the heart rate.

PubMed

Malchaire, Jacques; d'AMBROSIO Alfano, Francesca Romana; Palella, Boris Igor

2017-06-08

The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the metabolic rate at rest and the relation (HR vs. M) at the basis of the estimation of the equivalent metabolic rate, as a function of the age, height and weight of the person. A Monte Carlo simulation is used to determine, from the approximations of these parameters and formulas, the imprecision of the estimated equivalent metabolic rate. The results show that the standard deviation of this estimate varies from 10 to 15%.

Evaluation of the metabolic rate based on the recording of the heart rate

PubMed Central

MALCHAIRE, Jacques; ALFANO, Francesca Romana d’AMBROSIO; PALELLA, Boris Igor

2017-01-01

The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the metabolic rate at rest and the relation (HR vs. M) at the basis of the estimation of the equivalent metabolic rate, as a function of the age, height and weight of the person. A Monte Carlo simulation is used to determine, from the approximations of these parameters and formulas, the imprecision of the estimated equivalent metabolic rate. The results show that the standard deviation of this estimate varies from 10 to 15%. PMID:28250334

Unintentional Activation of Translation Equivalents in Bilinguals Leads to Attention Capture in a Cross-Modal Visual Task

PubMed Central

Singh, Niharika; Mishra, Ramesh Kumar

2015-01-01

Using a variant of the visual world eye tracking paradigm, we examined if language non- selective activation of translation equivalents leads to attention capture and distraction in a visual task in bilinguals. High and low proficient Hindi-English speaking bilinguals were instructed to programme a saccade towards a line drawing which changed colour among other distractor objects. A spoken word, irrelevant to the main task, was presented before the colour change. On critical trials, one of the line drawings was a phonologically related word of the translation equivalent of the spoken word. Results showed that saccade latency was significantly higher towards the target in the presence of this cross-linguistic translation competitor compared to when the display contained completely unrelated objects. Participants were also slower when the display contained the referent of the spoken word among the distractors. However, the bilingual groups did not differ with regard to the interference effect observed. These findings suggest that spoken words activates translation equivalent which bias attention leading to interference in goal directed action in the visual domain. PMID:25775184

Cognitive performance and its relationship with postprandial metabolic changes after ingestion of different macronutrients in the morning.

PubMed

Fischer, K; Colombani, P C; Langhans, W; Wenk, C

2001-03-01

The effect of carbohydrate, protein and fat ingestion on simple as well as complex cognitive functions and the relationship between the respective postprandial metabolic changes and changes in cognitive performance were studied in fifteen healthy male students. Subjects were tested in three sessions, separated by 1 week, for short-term changes in blood variables, indirect calorimetry, subjective performance and different objective performance tasks using a repeated-measures counterbalanced cross-over design. Measurements were made after an overnight fast before and hourly during 3 h after test meal ingestion. Test meals consisted of either pure carbohydrates, protein or fat and were served as isoenergetic (1670 kJ) spoonable creams with similar sensory properties. Most aspects of subjective performance did not differ between test meals. For all objective tasks, however, postprandial cognitive performance was best after fat ingestion concomitant with an almost constant glucose metabolism and constant metabolic activation state measured by glucagon:insulin (G:I). In contrast, carbohydrate as well as protein ingestion resulted in lower overall cognitive performance, both together with partly marked changes in glucose metabolism and metabolic activation. They also differently affected specific cognitive functions in relation to their specific effect on metabolism. Carbohydrate ingestion resulted in relatively better short-term memory and accuracy of tasks concomitant with low metabolic activation, whereas protein ingestion resulted in better attention and efficiency of tasks concomitant with higher metabolic activation. Our findings support the concept that good and stable cognitive performance is related to a balanced glucose metabolism and metabolic activation state.

Scalable and Axiomatic Ranking of Network Role Similarity

PubMed Central

Jin, Ruoming; Lee, Victor E.; Li, Longjie

2014-01-01

A key task in analyzing social networks and other complex networks is role analysis: describing and categorizing nodes according to how they interact with other nodes. Two nodes have the same role if they interact with equivalent sets of neighbors. The most fundamental role equivalence is automorphic equivalence. Unfortunately, the fastest algorithms known for graph automorphism are nonpolynomial. Moreover, since exact equivalence is rare, a more meaningful task is measuring the role similarity between any two nodes. This task is closely related to the structural or link-based similarity problem that SimRank addresses. However, SimRank and other existing similarity measures are not sufficient because they do not guarantee to recognize automorphically or structurally equivalent nodes. This paper makes two contributions. First, we present and justify several axiomatic properties necessary for a role similarity measure or metric. Second, we present RoleSim, a new similarity metric which satisfies these axioms and which can be computed with a simple iterative algorithm. We rigorously prove that RoleSim satisfies all these axiomatic properties. We also introduce Iceberg RoleSim, a scalable algorithm which discovers all pairs with RoleSim scores above a user-defined threshold θ. We demonstrate the interpretative power of RoleSim on both both synthetic and real datasets. PMID:25383066

Selecting Tasks for Evaluating Human Performance as a Function of Gravity

NASA Technical Reports Server (NTRS)

Norcross, J. R.; Gernhardt, M. L.

2010-01-01

A challenge in understanding human performance as a function of gravity is determining which tasks to research. Initial studies began with treadmill walking, which was easy to quantify and control. However, with the development of pressurized rovers, it is less important to optimize human performance for ambulation as rovers will likely perform gross translation for them. Future crews are likely to spend much of their extravehicular activity (EVA) performing geology, construction and maintenance type tasks, for which it is difficult to measure steady-state-workloads. To evaluate human performance in reduced gravity, we have collected metabolic, biomechanical and subjective data for different tasks at varied gravity levels. Methods: Ten subjects completed 5 different tasks including weight transfer, shoveling, treadmill walking, treadmill running and treadmill incline walking. All tasks were performed shirt-sleeved at 1-g, 3/8-g and 1/6-g. Off-loaded conditions were achieved via the Active Response Gravity Offload System. Treadmill tasks were performed for 3 minutes with reported oxygen consumption (VO2) averaged over the last 2 minutes. Shoveling was performed for 3 minutes with metabolic cost reported as ml O2 consumed per kg material shoveled. Weight transfer reports metabolic cost as liters O2 consumed to complete the task. Statistical analysis was performed via repeated measures ANOVA. Results: Statistically significant metabolic differences were noted between all 3 gravity levels for treadmill running and incline walking. For the other 3 tasks, there were significant differences between 1-g and each reduced gravity, but not between 1/6-g and 3/8-g. For weight transfer, significant differences were seen between gravities in both trial-average VO2 and time-to-completion with noted differences in strategy for task completion. Conclusion: To determine if gravity has a metabolic effect on human performance, this research may indicate that tasks should be selected that require the subject to work vertically against the force of gravity.

Selecting Tasks for Evaluating Human Performance as a Function of Gravity

NASA Technical Reports Server (NTRS)

Norcross, Jason R.; Gernhardt, Michael L.

2011-01-01

A challenge in understanding human performance as a function of gravity is determining which tasks to research. Initial studies began with treadmill walking, which was easy to quantify and control. However, with the development of pressurized rovers, it is less important to optimize human performance for ambulation as pressurized rovers will likely perform gross translation for them. Future crews are likely to spend much of their extravehicular activity (EVA) performing geology, construction,a nd maintenance type tasks. With these types of tasks, people have different performance strategies, and it is often difficult to quantify the task and measure steady-state metabolic rates or perform biomechanical analysis. For many of these types of tasks, subjective feedback may be the only data that can be collected. However, subjective data may not fully support a rigorous scientific comparison of human performance across different gravity levels and suit factors. NASA would benefit from having a wide variety of quantifiable tasks that allow human performance comparison across different conditions. In order to determine which tasks will effectively support scientific studies, many different tasks and data analysis techniques will need to be employed. Many of these tasks and techniques will not be effective, but some will produce quantifiable results that are sensitive enough to show performance differences. One of the primary concerns related to EVA performance is metabolic rate. The higher the metabolic rate, the faster the astronaut will exhaust consumables. The focus of this poster will be on how different tasks affect metabolic rate across different gravity levels.

[Generalization of money-handling though training in equivalence relationships].

PubMed

Vives-Montero, Carmen; Valero-Aguayo, Luis; Ascanio, Lourdes

2011-02-01

This research used a matching-to-sample procedure and equivalence learning process with language and verbal tasks. In the study, an application of the equivalence relationship of money was used with several kinds of euro coins presented. The sample consisted of 16 children (8 in the experimental group and 8 in the control group) aged 5 years. The prerequisite behaviors, the identification of coins and the practical use of different euro coins, were assessed in the pre and post phases for both groups. The children in the experimental group performed an equivalence task using the matching-to-sample procedure. This consisted of a stimulus sample and four matching stimuli, using a series of euro coins with equivalent value in each set. The children in the control group did not undergo this training process. The results showed a large variability in the children's data of the equivalence tests. The experimental group showed the greatest pre and post changes in the statistically significant data. They also showed a greater generalization in the identification of money and in the use of euro coins than the control group. The implications for educational training and the characteristics of the procedure used here for coin equivalence are discussed.

Stimulus-response learning in long-term cocaine users: acquired equivalence and probabilistic category learning.

PubMed

Vadhan, Nehal P; Myers, Catherine E; Rubin, Eric; Shohamy, Daphna; Foltin, Richard W; Gluck, Mark A

2008-01-11

The purpose of this study was to examine stimulus-response (S-R) learning in active cocaine users. Twenty-two cocaine-dependent participants (20 males and 2 females) and 21 non-drug using control participants (19 males and 2 females) who were similar in age and education were administered two computerized learning tasks. The Acquired Equivalence task initially requires learning of simple antecedent-consequent discriminations, but later requires generalization of this learning when the stimuli are presented in novel recombinations. The Weather Prediction task requires the prediction of a dichotomous outcome based on different stimuli combinations when the stimuli predict the outcome only probabilistically. On the Acquired Equivalence task, cocaine users made significantly more errors than control participants when required to learn new discriminations while maintaining previously learned discriminations, but performed similarly to controls when required to generalize this learning. No group differences were seen on the Weather Prediction task. Cocaine users' learning of stimulus discriminations under conflicting response demands was impaired, but their ability to generalize this learning once they achieved criterion was intact. This performance pattern is consistent with other laboratory studies of long-term cocaine users that demonstrated that established learning interfered with new learning on incremental learning tasks, relative to healthy controls, and may reflect altered dopamine transmission in the basal ganglia of long-term cocaine users.

Association among sickle cell trait, fitness, and cardiovascular risk factors in CARDIA.

PubMed

Liem, Robert I; Chan, Cheeling; Vu, Thanh-Huyen T; Fornage, Myriam; Thompson, Alexis A; Liu, Kiang; Carnethon, Mercedes R

2017-02-09

The contribution of sickle cell trait (SCT) to racial disparities in cardiopulmonary fitness is not known, despite concerns that SCT is associated with exertion-related sudden death. We evaluated the association of SCT status with cross-sectional and longitudinal changes in fitness and risk for hypertension, diabetes, and metabolic syndrome over the course of 25 years among 1995 African Americans (56% women, 18-30 years old) in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Overall, the prevalence of SCT was 6.8% (136/1995) in CARDIA, and over the course of 25 years, 46% (738/1590), 18% (288/1631), and 40% (645/1,611) of all participants developed hypertension, diabetes, and metabolic syndrome, respectively. Compared with participants without SCT, participants with SCT had similar baseline measures of fitness in cross-section, including exercise duration (535 vs 540 seconds; P = .62), estimated metabolic equivalent of tasks (METs; 11.6 vs 11.7; P = .80), maximum heart rate (174 vs 175 beats/min; P = .41), and heart rate at 2 minutes recovery (44 vs 43 beats/min; P = .28). In our secondary analysis, there was neither an association of SCT status with longitudinal changes in fitness nor an association with development of hypertension, diabetes, or metabolic syndrome after adjustment for sex, baseline age, body mass index, fitness, and physical activity. SCT is not associated with reduced fitness in this longitudinal study of young African American adults, suggesting the increased risk for exertion-related sudden death in SCT carriers is unlikely related to fitness. SCT status also is not an independent risk factor for developing hypertension, diabetes, or metabolic syndrome. © 2017 by The American Society of Hematology.

Nonlinear coupling between cerebral blood flow, oxygen consumption, and ATP production in human visual cortex.

PubMed

Lin, Ai-Ling; Fox, Peter T; Hardies, Jean; Duong, Timothy Q; Gao, Jia-Hong

2010-05-04

The purpose of this study was to investigate activation-induced hypermetabolism and hyperemia by using a multifrequency (4, 8, and 16 Hz) reversing-checkerboard visual stimulation paradigm. Specifically, we sought to (i) quantify the relative contributions of the oxidative and nonoxidative metabolic pathways in meeting the increased energy demands [i.e., ATP production (J(ATP))] of task-induced neuronal activation and (ii) determine whether task-induced cerebral blood flow (CBF) augmentation was driven by oxidative or nonoxidative metabolic pathways. Focal increases in CBF, cerebral metabolic rate of oxygen (CMRO(2); i.e., index of aerobic metabolism), and lactate production (J(Lac); i.e., index of anaerobic metabolism) were measured by using physiologically quantitative MRI and spectroscopy methods. Task-induced increases in J(ATP) were small (12.2-16.7%) at all stimulation frequencies and were generated by aerobic metabolism (approximately 98%), with %DeltaJ(ATP) being linearly correlated with the percentage change in CMRO(2) (r = 1.00, P < 0.001). In contrast, task-induced increases in CBF were large (51.7-65.1%) and negatively correlated with the percentage change in CMRO(2) (r = -0.64, P = 0.024), but positively correlated with %DeltaJ(Lac) (r = 0.91, P < 0.001). These results indicate that (i) the energy demand of task-induced brain activation is small (approximately 15%) relative to the hyperemic response (approximately 60%), (ii) this energy demand is met through oxidative metabolism, and (iii) the CBF response is mediated by factors other than oxygen demand.

Locomotor Adaptation Improves Balance Control, Multitasking Ability and Reduces the Metabolic Cost of Postural Instability

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Brady, R. A.; Batson, C. D.; Miller, C. A.; Ploutz-Snyder, R. J.; Guined, J. R.; Buxton, R. E.; Cohen, H. S.

2011-01-01

During exploration-class missions, sensorimotor disturbances may lead to disruption in the ability to ambulate and perform functional tasks during the initial introduction to a novel gravitational environment following a landing on a planetary surface. The overall goal of our current project is to develop a sensorimotor adaptability training program to facilitate rapid adaptation to these environments. We have developed a unique training system comprised of a treadmill placed on a motion-base facing a virtual visual scene. It provides an unstable walking surface combined with incongruent visual flow designed to enhance sensorimotor adaptability. Greater metabolic cost incurred during balance instability means more physical work is required during adaptation to new environments possibly affecting crewmembers? ability to perform mission critical tasks during early surface operations on planetary expeditions. The goal of this study was to characterize adaptation to a discordant sensory challenge across a number of performance modalities including locomotor stability, multi-tasking ability and metabolic cost. METHODS: Subjects (n=15) walked (4.0 km/h) on a treadmill for an 8 -minute baseline walking period followed by 20-minutes of walking (4.0 km/h) with support surface motion (0.3 Hz, sinusoidal lateral motion, peak amplitude 25.4 cm) provided by the treadmill/motion-base system. Stride frequency and auditory reaction time were collected as measures of locomotor stability and multi-tasking ability, respectively. Metabolic data (VO2) were collected via a portable metabolic gas analysis system. RESULTS: At the onset of lateral support surface motion, subj ects walking on our treadmill showed an increase in stride frequency and auditory reaction time indicating initial balance and multi-tasking disturbances. During the 20-minute adaptation period, balance control and multi-tasking performance improved. Similarly, throughout the 20-minute adaptation period, VO2 gradually decreased following an initial increase after the onset of support surface motion. DISCUSSION: Resu lts confirmed that walking in discordant conditions not only compromises locomotor stability and the ability to multi-task, but comes at a quantifiable metabolic cost. Importantly, like locomotor stability and multi-tasking ability, metabolic expenditure while walking in discordant sensory conditions improved during adaptation. This confirms that sensorimotor adaptability training can benefit multiple performance parameters central to the successful completion of critical mission tasks.

Oxidative status and lipid profile in metabolic syndrome: gender differences.

PubMed

Kaya, Aysem; Uzunhasan, Isil; Baskurt, Murat; Ozkan, Alev; Ataoglu, Esra; Okcun, Baris; Yigit, Zerrin

2010-02-01

Metabolic syndrome is associated with cardiovascular disease and oxidative stress. The aim of this study was to investigate the differences of novel oxidative stress parameters and lipid profiles in men and women with metabolic syndrome. The study population included 88 patients with metabolic syndrome, consisting of 48 postmenauposal women (group I) and 40 men (group II). Premenauposal women were excluded. Plasma levels of total antioxidant status (TAS) and total oxidative status (TOS) were determined by using the Erel automated measurement method, and oxidative stress index (OSI) was calculated. To perform the calculation, the resulting unit of TAS, mmol Trolox equivalent/L, was converted to micromol equivalent/L and the OSI value was calculated as: OSI = [(TOS, micromol/L)/(TAS, mmol Trolox equivalent/L) x 100]. The Student t-test, Mann-Whitney-U test, and chi-squared test were used for statistical analysis; the Pearson correlation coefficient and Spearman rank test were used for correlation analysis. P < or = 0.05 was considered to be statistically significant. Both women and men had similar properties regarding demographic characteristics and biochemical work up. Group II had significantly lower levels of antioxidant levels of TAS and lower levels of TOS and OSI compared with group I (P = 0.0001, P = 0.0035, and P = 0,0001). Apolipoprotein A (ApoA) levels were significantly higher in group I compared with group II. Our findings indicate that women with metabolic syndrome have a better antioxidant status and higher ApoA levels compared with men. Our findings suggest the existence of a higher oxidative stress index in men with metabolic syndrome. Considering the higher risk of atherosclerosis associated with men, these novel oxidative stress parameters may be valuable in the evaluation of patients with metabolic sydrome.

Physical activity and incident type 2 diabetes mellitus: a systematic review and dose-response meta-analysis of prospective cohort studies.

PubMed

Smith, Andrea D; Crippa, Alessio; Woodcock, James; Brage, Søren

2016-12-01

Inverse associations between physical activity (PA) and type 2 diabetes mellitus are well known. However, the shape of the dose-response relationship is still uncertain. This review synthesises results from longitudinal studies in general populations and uses non-linear models of the association between PA and incident type 2 diabetes. A systematic literature search identified 28 prospective studies on leisure-time PA (LTPA) or total PA and risk of type 2 diabetes. PA exposures were converted into metabolic equivalent of task (MET) h/week and marginal MET (MMET) h/week, a measure only considering energy expended above resting metabolic rate. Restricted cubic splines were used to model the exposure-disease relationship. Our results suggest an overall non-linear relationship; using the cubic spline model we found a risk reduction of 26% (95% CI 20%, 31%) for type 2 diabetes among those who achieved 11.25 MET h/week (equivalent to 150 min/week of moderate activity) relative to inactive individuals. Achieving twice this amount of PA was associated with a risk reduction of 36% (95% CI 27%, 46%), with further reductions at higher doses (60 MET h/week, risk reduction of 53%). Results for the MMET h/week dose-response curve were similar for moderate intensity PA, but benefits were greater for higher intensity PA and smaller for lower intensity activity. Higher levels of LTPA were associated with substantially lower incidence of type 2 diabetes in the general population. The relationship between LTPA and type 2 diabetes was curvilinear; the greatest relative benefits are achieved at low levels of activity, but additional benefits can be realised at exposures considerably higher than those prescribed by public health recommendations.

Bone-97 Alcohol and Skeletal Adaptation to Mechanical Usage.

DTIC Science & Technology

1999-10-01

dose response and time course effects of administered ethanol (Tasks 1 and 2) on blood alcohol levels, serum chemistry and bone metabolism...evaluation of the long-term skeletal effects of ethanol on bone metabolism and strength (Task 4); determination of the effects of ethanol on the skeletal...adaptation resistance exercise training (Task 5); determination of the effects of prior consumption of ethanol or PTH-induced increases in mRNA

The transfer of Cfunc contextual control through equivalence relations.

PubMed

Perez, William F; Fidalgo, Adriana P; Kovac, Roberta; Nico, Yara C

2015-05-01

Derived relational responding is affected by contextual stimuli (Cfunc) that select specific stimulus functions. The present study investigated the transfer of Cfunc contextual control through equivalence relations by evaluating both (a) the maintenance of Cfunc contextual control after the expansion of a relational network, and (b) the establishment of novel contextual stimuli by the transfer of Cfunc contextual control through equivalence relations. Initially, equivalence relations were established and contingencies were arranged so that colors functioned as Cfunc stimuli controlling participants' key-pressing responses in the presence of any stimulus from a three-member equivalence network. To investigate the first research question, the three-member equivalence relations were expanded to five members and the novel members were presented with the Cfunc stimuli in the key-pressing task. To address the second goal of this study, the colors (Cfunc) were established as equivalent to certain line patterns. The transfer of contextual cue function (Cfunc) was tested replacing the colored backgrounds with line patterns in the key-pressing task. Results suggest that the Cfunc contextual control was transferred to novel stimuli that were added to the relational network. In addition, the line patterns indirectly acquired the contextual cue function (Cfunc) initially established for the colored backgrounds. The conceptual and applied implications of Cfunc contextual control are discussed. © Society for the Experimental Analysis of Behavior.

Cerebral metabolic dysfunction and impaired vigilance in recently abstinent methamphetamine abusers.

PubMed

London, Edythe D; Berman, Steven M; Voytek, Bradley; Simon, Sara L; Mandelkern, Mark A; Monterosso, John; Thompson, Paul M; Brody, Arthur L; Geaga, Jennifer A; Hong, Michael S; Hayashi, Kiralee M; Rawson, Richard A; Ling, Walter

2005-11-15

Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and structural deficits in limbic and paralimbic cortices, and reduced hippocampal volume. The links between cognitive impairment and these cerebral abnormalities are not established. We assessed cerebral glucose metabolism with [F-18]fluorodeoxyglucose positron emission tomography in 17 abstinent (4 to 7 days) methamphetamine users and 16 control subjects performing an auditory vigilance task and obtained structural magnetic resonance brain scans. Regional brain radioactivity served as a marker for relative glucose metabolism. Error rates on the task were related to regional radioactivity and hippocampal morphology. Methamphetamine users had higher error rates than control subjects on the vigilance task. The groups showed different relationships between error rates and relative activity in the anterior and middle cingulate gyrus and the insula. Whereas the MA user group showed negative correlations involving these regions, the control group showed positive correlations involving the cingulate cortex. Across groups, hippocampal metabolic and structural measures were negatively correlated with error rates. Dysfunction in the cingulate and insular cortices of recently abstinent MA abusers contribute to impaired vigilance and other cognitive functions requiring sustained attention. Hippocampal integrity predicts task performance in methamphetamine users as well as control subjects.

Behavioral inference of diving metabolic rate in free-ranging leatherback turtles.

PubMed

Bradshaw, Corey J A; McMahon, Clive R; Hays, Graeme C

2007-01-01

Good estimates of metabolic rate in free-ranging animals are essential for understanding behavior, distribution, and abundance. For the critically endangered leatherback turtle (Dermochelys coriacea), one of the world's largest reptiles, there has been a long-standing debate over whether this species demonstrates any metabolic endothermy. In short, do leatherbacks have a purely ectothermic reptilian metabolic rate or one that is elevated as a result of regional endothermy? Recent measurements have provided the first estimates of field metabolic rate (FMR) in leatherback turtles using doubly labeled water; however, the technique is prohibitively expensive and logistically difficult and produces estimates that are highly variable across individuals in this species. We therefore examined dive duration and depth data collected for nine free-swimming leatherback turtles over long periods (up to 431 d) to infer aerobic dive limits (ADLs) based on the asymptotic increase in maximum dive duration with depth. From this index of ADL and the known mass-specific oxygen storage capacity (To(2)) of leatherbacks, we inferred diving metabolic rate (DMR) as To2/ADL. We predicted that if leatherbacks conform to the purely ectothermic reptilian model of oxygen consumption, these inferred estimates of DMR should fall between predicted and measured values of reptilian resting and field metabolic rates, as well as being substantially lower than the FMR predicted for an endotherm of equivalent mass. Indeed, our behaviorally derived DMR estimates (mean=0.73+/-0.11 mL O(2) min(-1) kg(-1)) were 3.00+/-0.54 times the resting metabolic rate measured in unrestrained leatherbacks and 0.50+/-0.08 times the average FMR for a reptile of equivalent mass. These DMRs were also nearly one order of magnitude lower than the FMR predicted for an endotherm of equivalent mass. Thus, our findings lend support to the notion that diving leatherback turtles are indeed ectothermic and do not demonstrate elevated metabolic rates that might be expected due to regional endothermy. Their capacity to have a warm body core even in cold water therefore seems to derive from their large size, heat exchangers, thermal inertia, and insulating fat layers and not from an elevated metabolic rate.

Metabolism drives distribution and abundance in extremophile fish

PubMed Central

McHugh, Peter A.; Glover, Chris N.; McIntosh, Angus R.

2017-01-01

Differences in population density between species of varying size are frequently attributed to metabolic rates which are assumed to scale with body size with a slope of 0.75. This assumption is often criticised on the grounds that 0.75 scaling of metabolic rate with body size is not universal and can vary significantly depending on species and life-history. However, few studies have investigated how interspecific variation in metabolic scaling relationships affects population density in different sized species. Here we predict inter-specific differences in metabolism from niche requirements, thereby allowing metabolic predictions of species distribution and abundance at fine spatial scales. Due to the differences in energetic efficiency required along harsh-benign gradients, an extremophile fish (brown mudfish, Neochanna apoda) living in harsh environments had slower metabolism, and thus higher population densities, compared to a fish species (banded kōkopu, Galaxias fasciatus) in physiologically more benign habitats. Interspecific differences in the intercepts for the relationship between body and density disappeared when species mass-specific metabolic rates, rather than body sizes, were used to predict density, implying population energy use was equivalent between mudfish and kōkopu. Nevertheless, despite significant interspecific differences in the slope of the metabolic scaling relationships, mudfish and kōkopu had a common slope for the relationship between body size and population density. These results support underlying logic of energetic equivalence between different size species implicit in metabolic theory. However, the precise slope of metabolic scaling relationships, which is the subject of much debate, may not be a reliable indicator of population density as expected under metabolic theory. PMID:29176819

Gender Effects When Learning Manipulative Tasks from Instructional Animations and Static Presentations

ERIC Educational Resources Information Center

Wong, Mona; Castro-Alonso, Juan C.; Ayres, Paul; Paas, Fred

2015-01-01

Humans have an evolved embodied cognition that equips them to deal easily with the natural movements of object manipulations. Hence, learning a manipulative task is generally more effective when watching animations that show natural motions of the task, rather than equivalent static pictures. The present study was completed to explore this…

Impact of Static Graphics, Animated Graphics and Mental Imagery on a Complex Learning Task

ERIC Educational Resources Information Center

Lai, Feng-Qi; Newby, Timothy J.

2012-01-01

The present study compared the impact of different categories of graphics used within a complex learning task. One hundred eighty five native English speaking undergraduates participated in a task that required learning 18 Chinese radicals and their English equivalent translations. A post-test only control group design compared performance…

Prognostic capacity of a clinically indicated exercise test for cardiovascular mortality is enhanced by combined analysis of exercise capacity, heart rate recovery and T-wave alternans.

PubMed

Minkkinen, Mikko; Nieminen, Tuomo; Verrier, Richard L; Leino, Johanna; Lehtimäki, Terho; Viik, Jari; Lehtinen, Rami; Nikus, Kjell; Kööbi, Tiit; Turjanmaa, Väinö; Kähönen, Mika

2015-09-01

Exercise capacity, heart rate recovery and T-wave alternans are independent predictors of cardiovascular mortality. We tested whether these parameters contain supplementary prognostic information. A total of 3609 consecutive patients (2157 men) referred for a routine, clinically indicated bicycle exercise test were enrolled in the Finnish Cardiovascular Study (FINCAVAS). Exercise capacity was measured in metabolic equivalents, heart rate recovery as the decrease in heart rate from maximum to one minute post-exercise, and T-wave alternans by time-domain Modified Moving Average method. During 57-month median follow-up (interquartile range 35-78 months), 96 patients died of cardiovascular causes (primary endpoint) and 233 from any cause. All three parameters were independent predictors of cardiovascular mortality when analysed as continuous variables. Adding metabolic equivalents (p < 0.001), heart rate recovery (p = 0.002) or T-wave alternans (p = 0.01) to the linear model improved its predictive power for cardiovascular mortality. The combination of low exercise capacity (<6 metabolic equivalents), reduced heart rate recovery (≤12 beats/min) and elevated T-wave alternans (≥60 μV) yielded the highest hazard ratio for cardiovascular mortality of 16.5 (95% confidence interval 4.0-67.7, p < 0.001). Harrell's C index was 0.719 (confidence interval 0.665-0.772) for cardiovascular mortality with previously defined cutpoints (<8 units for metabolic equivalents, ≤18 beats/min for heart rate recovery and ≥60 μV for T-wave alternans). The prognostic capacity of the clinical exercise test is enhanced by combined analysis of exercise capacity, heart rate recovery and T-wave alternans. © The European Society of Cardiology 2014.

Equivalence of the Color Trails Test and Trail Making Test in nonnative English-speakers.

PubMed

Dugbartey, A T; Townes, B D; Mahurin, R K

2000-07-01

The Color Trails Test (CTT) has been described as a culture-fair test of visual attention, graphomotor sequencing, and effortful executive processing abilities relative to the Trail Making Test (TMT). In this study, the equivalence of the TMT and the CTT among a group of 64 bilingual Turkish university students was examined. No difference in performance on the CTT-1 and TMT Part A was found, suggesting functionally equivalent performance across both tasks. In contrast, the statistically significant differences in performance on CTT-2 and TMT Part B, as well as the interference indices for both tests, were interpreted as providing evidence for task nonequivalence of the CTT-2 and TMT Part B. Results have implications for both psychometric test development and clinical cultural neuropsychology.

Steady-state global optimization of metabolic non-linear dynamic models through recasting into power-law canonical models

PubMed Central

2011-01-01

Background Design of newly engineered microbial strains for biotechnological purposes would greatly benefit from the development of realistic mathematical models for the processes to be optimized. Such models can then be analyzed and, with the development and application of appropriate optimization techniques, one could identify the modifications that need to be made to the organism in order to achieve the desired biotechnological goal. As appropriate models to perform such an analysis are necessarily non-linear and typically non-convex, finding their global optimum is a challenging task. Canonical modeling techniques, such as Generalized Mass Action (GMA) models based on the power-law formalism, offer a possible solution to this problem because they have a mathematical structure that enables the development of specific algorithms for global optimization. Results Based on the GMA canonical representation, we have developed in previous works a highly efficient optimization algorithm and a set of related strategies for understanding the evolution of adaptive responses in cellular metabolism. Here, we explore the possibility of recasting kinetic non-linear models into an equivalent GMA model, so that global optimization on the recast GMA model can be performed. With this technique, optimization is greatly facilitated and the results are transposable to the original non-linear problem. This procedure is straightforward for a particular class of non-linear models known as Saturable and Cooperative (SC) models that extend the power-law formalism to deal with saturation and cooperativity. Conclusions Our results show that recasting non-linear kinetic models into GMA models is indeed an appropriate strategy that helps overcoming some of the numerical difficulties that arise during the global optimization task. PMID:21867520

Metabolic Assessment of Suited Mobility Using Functional Tasks

NASA Technical Reports Server (NTRS)

Norcross, J. R.; McFarland, S. M.; Ploutz-Snyder, Robert

2016-01-01

Existing methods for evaluating extravehicular activity (EVA) suit mobility have typically focused on isolated joint range of motion or torque, but these techniques have little to do with how well a crewmember functionally performs in an EVA suit. To evaluate suited mobility at the system level through measuring metabolic cost (MC) of functional tasks.

Cardinal Equivalence of Small Number in Young Children.

ERIC Educational Resources Information Center

Kingma, J.; Roelinga, U.

1982-01-01

Children completed three types of equivalent cardination tasks which assessed the influence of different stimulus configurations (linear, linear-nonlinear, and nonlinear), and density of object spacing. Prior results reported by Siegel, Brainerd, and Gelman and Gallistel were not replicated. Implications for understanding cardination concept…

Development of an Objective Space Suit Mobility Performance Metric Using Metabolic Cost and Functional Tasks

NASA Technical Reports Server (NTRS)

McFarland, Shane M.; Norcross, Jason

2016-01-01

Existing methods for evaluating EVA suit performance and mobility have historically concentrated on isolated joint range of motion and torque. However, these techniques do little to evaluate how well a suited crewmember can actually perform during an EVA. An alternative method of characterizing suited mobility through measurement of metabolic cost to the wearer has been evaluated at Johnson Space Center over the past several years. The most recent study involved six test subjects completing multiple trials of various functional tasks in each of three different space suits; the results indicated it was often possible to discern between different suit designs on the basis of metabolic cost alone. However, other variables may have an effect on real-world suited performance; namely, completion time of the task, the gravity field in which the task is completed, etc. While previous results have analyzed completion time, metabolic cost, and metabolic cost normalized to system mass individually, it is desirable to develop a single metric comprising these (and potentially other) performance metrics. This paper outlines the background upon which this single-score metric is determined to be feasible, and initial efforts to develop such a metric. Forward work includes variable coefficient determination and verification of the metric through repeated testing.

Metabolic effect of bodyweight whole-body vibration in a 20-min exercise session: A crossover study using verified vibration stimulus.

PubMed

Milanese, Chiara; Cavedon, Valentina; Sandri, Marco; Tam, Enrico; Piscitelli, Francesco; Boschi, Federico; Zancanaro, Carlo

2018-01-01

The ability of whole body vibration (WBV) to increase energy expenditure (EE) has been investigated to some extent in the past using short-term single exercises or sets of single exercises. However, the current practice in WBV training for fitness is based on the execution of multiple exercises during a WBV training session for a period of at least 20 min; nevertheless, very limited and inconsistent data are available on EE during long term WBV training session. This crossover study was designed to demonstrate, in an adequately powered sample of participants, the ability of WBV to increase the metabolic cost of exercise vs. no vibration over the time span of a typical WBV session for fitness (20 min). Twenty-two physically active young males exercised on a vibration platform (three identical sets of six different exercises) using an accelerometer-verified vibration stimulus in both the WBV and no vibration condition. Oxygen consumption was measured with indirect calorimetry and expressed as area under the curve (O2(AUC)). Results showed that, in the overall 20-min training session, WBV increased both the O2(AUC) and the estimated EE vs. no vibration by about 22% and 20%, respectively (P<0.001 for both, partial eta squared [η2] ≥0.35) as well as the metabolic equivalent of task (+5.5%, P = 0.043; η2 = 0.02) and the rate of perceived exertion (+13%, P<0.001; ŋ2 = 0.16). Results demonstrated that vibration is able to significantly increase the metabolic cost of exercise in a 20-min WBV training session.

Metabolic effect of bodyweight whole-body vibration in a 20-min exercise session: A crossover study using verified vibration stimulus

PubMed Central

Sandri, Marco; Tam, Enrico; Piscitelli, Francesco; Boschi, Federico

2018-01-01

The ability of whole body vibration (WBV) to increase energy expenditure (EE) has been investigated to some extent in the past using short-term single exercises or sets of single exercises. However, the current practice in WBV training for fitness is based on the execution of multiple exercises during a WBV training session for a period of at least 20 min; nevertheless, very limited and inconsistent data are available on EE during long term WBV training session. This crossover study was designed to demonstrate, in an adequately powered sample of participants, the ability of WBV to increase the metabolic cost of exercise vs. no vibration over the time span of a typical WBV session for fitness (20 min). Twenty-two physically active young males exercised on a vibration platform (three identical sets of six different exercises) using an accelerometer-verified vibration stimulus in both the WBV and no vibration condition. Oxygen consumption was measured with indirect calorimetry and expressed as area under the curve (O2(AUC)). Results showed that, in the overall 20-min training session, WBV increased both the O2(AUC) and the estimated EE vs. no vibration by about 22% and 20%, respectively (P<0.001 for both, partial eta squared [η2] ≥0.35) as well as the metabolic equivalent of task (+5.5%, P = 0.043; η2 = 0.02) and the rate of perceived exertion (+13%, P<0.001; ŋ2 = 0.16). Results demonstrated that vibration is able to significantly increase the metabolic cost of exercise in a 20-min WBV training session. PMID:29385196

What Did I Say? Versus What Did I Think? Attributing False Beliefs to Self amongst Children with and without Autism

ERIC Educational Resources Information Center

Williams, David M.; Happe, Francesca

2009-01-01

The task used most widely to assess recognition of false belief in self "and" others is the "Smarties" unexpected contents task. Amongst individuals with and without autism, the Self and Other-person test questions of this task are of an equivalent level of difficulty. However, a potential confound with this task may allow the Self test question…

Between-language repetition priming in antonym generation: evidence that translation-equivalent adjectives have shared conceptual representations across languages.

PubMed

Taylor, Randolph S; Francis, Wendy S

2017-03-01

Previous literature has demonstrated conceptual repetition priming across languages in bilinguals. This between-language priming effect is taken as evidence that translation equivalents have shared conceptual representations across languages. However, the vast majority of this research has been conducted using only concrete nouns as stimuli. The present experiment examined conceptual repetition priming within and between languages in adjectives, a part of speech not previously investigated in studies of bilingual conceptual representation. The participants were 100 Spanish-English bilinguals who had regular exposure to both languages. At encoding, participants performed a shallow processing task and a deep-processing task on English and Spanish adjectives. At test, they performed an antonym-generation task in English, in which the target responses were either adjectives presented at encoding or control adjectives not previously presented. The measure of priming was the response time advantage for producing repeated adjectives relative to control adjectives. Significant repetition priming was observed both within and between languages under deep, but not shallow, encoding conditions. The results indicate that the conceptual representations of adjective translation equivalents are shared across languages.

Exercise Testing Reveals Everyday Physical Challenges of Bariatric Surgery Candidates.

PubMed

Creel, David B; Schuh, Leslie M; Newton, Robert L; Stote, Joseph J; Cacucci, Brenda M

2017-12-01

Few studies have quantified cardiorespiratory fitness among individuals seeking bariatric surgery. Treadmill testing allows researchers to determine exercise capacity through metabolic equivalents. These findings can assist clinicians in understanding patients' capabilities to carry out various activities of daily living. The purpose of this study was to determine exercise tolerance and the variables associated with fitness, among individuals seeking bariatric surgery. Bariatric surgery candidates completed submaximal treadmill testing and provided ratings of perceived exertion. Each participant also completed questionnaires related to history of exercise, mood, and perceived barriers/benefits of exercise. Over half of participants reported that exercise was "hard to very hard" before reaching 70% of heart rate reserve, and one-third of participants reported that exercise was "moderately hard" at less than 3 metabolic equivalents (light activity). Body mass index and age accounted for the majority of the variance in exercise tolerance, but athletic history, employment status, and perceived health benefits also contributed. Perceived benefit scores were higher than barrier scores. Categories commonly used to describe moderate-intensity exercise (3-6 metabolic equivalents) do not coincide with perceptions of intensity among many bariatric surgery candidates, especially those with a body mass index of 50 or more.

A low-cost method for estimating energy expenditure during soccer refereeing.

PubMed

Ardigò, Luca Paolo; Padulo, Johnny; Zuliani, Andrea; Capelli, Carlo

2015-01-01

This study aimed to apply a validated bioenergetics model of sprint running to recordings obtained from commercial basic high-sensitivity global positioning system receivers to estimate energy expenditure and physical activity variables during soccer refereeing. We studied five Italian fifth division referees during 20 official matches while carrying the receivers. By applying the model to the recorded speed and acceleration data, we calculated energy consumption during activity, mass-normalised total energy consumption, total distance, metabolically equivalent distance and their ratio over the entire match and the two halves. Main results were as follows: (match) energy consumption = 4729 ± 608 kJ, mass normalised total energy consumption = 74 ± 8 kJ · kg(-1), total distance = 13,112 ± 1225 m, metabolically equivalent distance = 13,788 ± 1151 m and metabolically equivalent/total distance = 1.05 ± 0.05. By using a very low-cost device, it is possible to estimate the energy expenditure of soccer refereeing. The provided predicting mass-normalised total energy consumption versus total distance equation can supply information about soccer refereeing energy demand.

Recommendations on evidence needed to support measurement equivalence between electronic and paper-based patient-reported outcome (PRO) measures: ISPOR ePRO Good Research Practices Task Force report.

PubMed

Coons, Stephen Joel; Gwaltney, Chad J; Hays, Ron D; Lundy, J Jason; Sloan, Jeff A; Revicki, Dennis A; Lenderking, William R; Cella, David; Basch, Ethan

2009-06-01

Patient-reported outcomes (PROs) are the consequences of disease and/or its treatment as reported by the patient. The importance of PRO measures in clinical trials for new drugs, biological agents, and devices was underscored by the release of the US Food and Drug Administration's draft guidance for industry titled "Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims." The intent of the guidance was to describe how the FDA will evaluate the appropriateness and adequacy of PRO measures used as effectiveness end points in clinical trials. In response to the expressed need of ISPOR members for further clarification of several aspects of the draft guidance, ISPOR's Health Science Policy Council created three task forces, one of which was charged with addressing the implications of the draft guidance for the collection of PRO data using electronic data capture modes of administration (ePRO). The objective of this report is to present recommendations from ISPOR's ePRO Good Research Practices Task Force regarding the evidence necessary to support the comparability, or measurement equivalence, of ePROs to the paper-based PRO measures from which they were adapted. The task force was composed of the leadership team of ISPOR's ePRO Working Group and members of another group (i.e., ePRO Consensus Development Working Group) that had already begun to develop recommendations regarding ePRO good research practices. The resulting task force membership reflected a broad array of backgrounds, perspectives, and expertise that enriched the development of this report. The prior work became the starting point for the Task Force report. A subset of the task force members became the writing team that prepared subsequent iterations of the report that were distributed to the full task force for review and feedback. In addition, review beyond the task force was sought and obtained. Along with a presentation and discussion period at an ISPOR meeting, a draft version of the full report was distributed to roughly 220 members of a reviewer group. The reviewer group comprised individuals who had responded to an emailed invitation to the full membership of ISPOR. This Task Force report reflects the extensive internal and external input received during the 16-month good research practices development process. RESULTS/RECOMMENDATIONS: An ePRO questionnaire that has been adapted from a paper-based questionnaire ought to produce data that are equivalent or superior (e.g., higher reliability) to the data produced from the original paper version. Measurement equivalence is a function of the comparability of the psychometric properties of the data obtained via the original and adapted administration mode. This comparability is driven by the amount of modification to the content and format of the original paper PRO questionnaire required during the migration process. The magnitude of a particular modification is defined with reference to its potential effect on the content, meaning, or interpretation of the measure's items and/or scales. Based on the magnitude of the modification, evidence for measurement equivalence can be generated through combinations of the following: cognitive debriefing/testing, usability testing, equivalence testing, or, if substantial modifications have been made, full psychometric testing. As long as only minor modifications were made to the measure during the migration process, a substantial body of existing evidence suggests that the psychometric properties of the original measure will still hold for the ePRO version. Hence, an evaluation limited to cognitive debriefing and usability testing only may be sufficient. However, where more substantive changes in the migration process has occurred, confirming that the adaptation to the ePRO format did not introduce significant response bias and that the two modes of administration produce essentially equivalent results is necessary. Recommendations regarding the study designs and statistical approaches for assessing measurement equivalence are provided. The electronic administration of PRO measures offers many advantages over paper administration. We provide a general framework for decisions regarding the level of evidence needed to support modifications that are made to PRO measures when they are migrated from paper to ePRO devices. The key issues include: 1) the determination of the extent of modification required to administer the PRO on the ePRO device and 2) the selection and implementation of an effective strategy for testing the measurement equivalence of the two modes of administration. We hope that these good research practice recommendations provide a path forward for researchers interested in migrating PRO measures to electronic data collection platforms.

Metabolic flux analysis of heterotrophic growth in Chlamydomonas reinhardtii.

PubMed

Boyle, Nanette R; Sengupta, Neelanjan; Morgan, John A

2017-01-01

Despite the wealth of knowledge available for C. reinhardtii, the central metabolic fluxes of growth on acetate have not yet been determined. In this study, 13C-metabolic flux analysis (13C-MFA) was used to determine and quantify the metabolic pathways of primary metabolism in C. reinhardtii cells grown under heterotrophic conditions with acetate as the sole carbon source. Isotopic labeling patterns of compartment specific biomass derived metabolites were used to calculate the fluxes. It was found that acetate is ligated with coenzyme A in the three subcellular compartments (cytosol, mitochondria and plastid) included in the model. Two citrate synthases were found to potentially be involved in acetyl-coA metabolism; one localized in the mitochondria and the other acting outside the mitochondria. Labeling patterns demonstrate that Acetyl-coA synthesized in the plastid is directly incorporated in synthesis of fatty acids. Despite having a complete TCA cycle in the mitochondria, it was also found that a majority of the malate flux is shuttled to the cytosol and plastid where it is converted to oxaloacetate providing reducing equivalents to these compartments. When compared to predictions by flux balance analysis, fluxes measured with 13C-MFA were found to be suboptimal with respect to biomass yield; C. reinhardtii sacrifices biomass yield to produce ATP and reducing equivalents.

Event-related potential correlates of emergent inference in human arbitrary relational learning.

PubMed

Wang, Ting; Dymond, Simon

2013-01-01

Two experiments investigated the functional-anatomical correlates of cognition supporting untrained, emergent relational inference in a stimulus equivalence task. In Experiment 1, after learning a series of conditional relations involving words and pseudowords, participants performed a relatedness task during which EEG was recorded. Behavioural performance was faster and more accurate on untrained, indirectly related symmetry (i.e., learn AB and infer BA) and equivalence trials (i.e., learn AB and AC and infer CB) than on unrelated trials, regardless of whether or not a formal test for stimulus equivalence relations had been conducted. Consistent with previous results, event related potentials (ERPs) evoked by trained and emergent trials at parietal and occipital sites differed only for those participants who had not received a prior equivalence test. Experiment 2 further replicated and extended these behavioural and ERP findings using arbitrary symbols as stimuli and demonstrated time and frequency differences for trained and untrained relatedness trials. Overall, the findings demonstrate convincingly the ERP correlates of intra-experimentally established stimulus equivalence relations consisting entirely of arbitrary symbols and offer support for a contemporary cognitive-behavioural model of symbolic categorisation and relational inference. Copyright © 2012 Elsevier B.V. All rights reserved.

The default mode network in chimpanzees (Pan troglodytes) is similar to that of humans.

PubMed

Barks, Sarah K; Parr, Lisa A; Rilling, James K

2015-02-01

The human default mode network (DMN), comprising medial prefrontal cortex, precuneus, posterior cingulate cortex, lateral parietal cortex, and medial temporal cortex, is highly metabolically active at rest but deactivates during most focused cognitive tasks. The DMN and social cognitive networks overlap significantly in humans. We previously demonstrated that chimpanzees (Pan troglodytes) show highest resting metabolic brain activity in the cortical midline areas of the human DMN. Human DMN is defined by task-induced deactivations, not absolute resting metabolic levels; ergo, resting activity is insufficient to define a DMN in chimpanzees. Here, we assessed the chimpanzee DMN's deactivations relative to rest during cognitive tasks and the effect of social content on these areas' activity. Chimpanzees performed a match-to-sample task with conspecific behavioral stimuli of varying sociality. Using [(18)F]-FDG PET, brain activity during these tasks was compared with activity during a nonsocial task and at rest. Cortical midline areas in chimpanzees deactivated in these tasks relative to rest, suggesting a chimpanzee DMN anatomically and functionally similar to humans. Furthermore, when chimpanzees make social discriminations, these same areas (particularly precuneus) are highly active relative to nonsocial tasks, suggesting that, as in humans, the chimpanzee DMN may play a role in social cognition. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cognitive and affective control in a flanker word task: common and dissociable brain mechanisms.

PubMed

Alguacil, Sonia; Tudela, Pío; Ruz, María

2013-08-01

In the present study we compared the nature of cognitive and affective conflict modulations at different stages of information processing using electroencephalographic recordings. Participants performed a flanker task in which they had to focus on a central word target and indicate its semantic category (cognitive version) or its valence (affective version). Targets were flanked by congruent or incongruent words in both versions. Although tasks were equivalent at the behavioral level, event-related potentials (ERPs) showed common and dissociable cognitive and emotional conflict modulations. At early stages of information processing, both tasks generated parallel sequential conflict effects in the P1 and N170 potentials. Later, the N2 and the first part of the P3 wave were exclusively modulated by cognitive conflict, whereas the last section of the P3 deflection/Late Positive Component (LPC) was only involved in affective current conflict processing. Therefore, the whole data set suggests the existence of early common mechanisms that are equivalent for cognitive and affective materials and later task-specific conflict processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Equivalence Testing as a Tool for Fatigue Risk Management in Aviation.

PubMed

Wu, Lora J; Gander, Philippa H; van den Berg, Margo; Signal, T Leigh

2018-04-01

Many civilian aviation regulators favor evidence-based strategies that go beyond hours-of-service approaches for managing fatigue risk. Several countries now allow operations to be flown outside of flight and duty hour limitations, provided airlines demonstrate an alternative method of compliance that yields safety levels "at least equivalent to" the prescriptive regulations. Here we discuss equivalence testing in occupational fatigue risk management. We present suggested ratios/margins of practical equivalence when comparing operations inside and outside of prescriptive regulations for two common aviation safety performance indicators: total in-flight sleep duration and psychomotor vigilance task reaction speed. Suggested levels of practical equivalence, based on expertise coupled with evidence from field and laboratory studies, are ≤ 30 min in-flight sleep and ± 15% of reference response speed. Equivalence testing is illustrated in analyses of a within-subjects field study during an out-and-back long-range trip. During both sectors of their trip, 41 pilots were monitored via actigraphy, sleep diary, and top of descent psychomotor vigilance task. Pilots were assigned to take rest breaks in a standard lie-flat bunk on one sector and in a bunk tapered 9 from hip to foot on the other sector. Total in-flight sleep duration (134 ± 53 vs. 135 ± 55 min) and mean reaction speed at top of descent (3.94 ± 0.58 vs. 3.77 ± 0.58) were equivalent after rest in the full vs. tapered bunk. Equivalence testing is a complimentary statistical approach to difference testing when comparing levels of fatigue and performance in occupational settings and can be applied in transportation policy decision making.Wu LJ, Gander PH, van den Berg M, Signal TL. Equivalence testing as a tool for fatigue risk management in aviation. Aerosp Med Hum Perform. 2018; 89(4):383-388.

Attention Performance in Autism and Regional Brain Metabolic Rate Assessed by Positron Emission Tomography. Brief Report.

ERIC Educational Resources Information Center

Buchsbaum, M. S.; And Others

1992-01-01

This evaluation of seven high functioning adults with autism utilized positron emission tomography on a visual vigilance task. Although the subjects, as a group, did as well as normal controls on the task, there was a lack of normal hemispheric asymmetry in glucose metabolic rate. A heterogeneous etiology for autism is suggested to explain…

Verbal fluency and positron emission tomographic mapping of regional cerebral glucose metabolism.

PubMed

Boivin, M J; Giordani, B; Berent, S; Amato, D A; Lehtinen, S; Koeppe, R A; Buchtel, H A; Foster, N L; Kuhl, D E

1992-06-01

Impairment in verbal fluency (VF) has been a consistently reported clinical feature of focal cerebral deficits in frontal and temporal regions. More recent behavioral activation studies with healthy control subjects using positron emission tomography (PET), however, have noted a negative correlation between performance on verbal fluency tasks and regional cortical activity. To see if this negative relationship extends to steady-state non-activation PET measures, thirty-three healthy adults were given a VF task within a day of their 18F-2-fluoro-2-deoxy-D-glucose PET scan. VF was found to correlate positively with left temporal cortical region metabolic activity but to correlate negatively with right and left frontal activity. VF was not correlated significantly with right temporal cortical metabolic activity. Some previous studies with normals using behavioral activation paradigms and PET have reported negative correlations between metabolic activity and cognitive performance similar to that reported here. An explanation for the disparate relationships that were observed between frontal and temporal brain areas and VF might be found in the mediation of different task demands by these separate locations, i.e., task planning and/or initiation by frontal regions and verbal memory by the left temporal area.

Working memory operates over the same representations as attention

PubMed Central

Xie, Jiushu; Xia, Tiansheng; Mo, Lei

2017-01-01

A recent study observed a working memory (WM) Stroop effect with a magnitude equivalent to that of the classic Stroop effect, indicating that WM operates over the same representations as attention. However, more research is needed to examine this proposal. One unanswered question is whether the WM Stroop effect occurs when the WM item and the perceptual task do not have an overlapping response set. We addressed this question in Experiment 1 by conducting an attentional word-color task and a WM word-color task. The results showed that a WM Stroop effect also occurred in that condition, as a word that only indirectly evoked a color representation could interfere with the color judgement in both the attentional task and WM task. In Experiment 2, we used a classic Simon task and a WM Simon task to examine whether holding visuo-spatial information rather than verbal information in WM could interfere with perceptual judgment as well. We observed a WM Simon effect of equivalent magnitude to that of the classic Simon effect. The well-known stimulus-response compatibility effect also existed in the WM domain. The two experiments together demonstrated that WM operates over the same representations as attention, which sheds new light on the hypothesis that working memory is internally directed attention. PMID:28604840

Working memory operates over the same representations as attention.

PubMed

Chen, Ke; Ye, Yanyan; Xie, Jiushu; Xia, Tiansheng; Mo, Lei

2017-01-01

A recent study observed a working memory (WM) Stroop effect with a magnitude equivalent to that of the classic Stroop effect, indicating that WM operates over the same representations as attention. However, more research is needed to examine this proposal. One unanswered question is whether the WM Stroop effect occurs when the WM item and the perceptual task do not have an overlapping response set. We addressed this question in Experiment 1 by conducting an attentional word-color task and a WM word-color task. The results showed that a WM Stroop effect also occurred in that condition, as a word that only indirectly evoked a color representation could interfere with the color judgement in both the attentional task and WM task. In Experiment 2, we used a classic Simon task and a WM Simon task to examine whether holding visuo-spatial information rather than verbal information in WM could interfere with perceptual judgment as well. We observed a WM Simon effect of equivalent magnitude to that of the classic Simon effect. The well-known stimulus-response compatibility effect also existed in the WM domain. The two experiments together demonstrated that WM operates over the same representations as attention, which sheds new light on the hypothesis that working memory is internally directed attention.

Multi-finger synergies and the muscular apparatus of the hand.

PubMed

Cuadra, Cristian; Bartsch, Angelo; Tiemann, Paula; Reschechtko, Sasha; Latash, Mark L

2018-05-01

We explored whether the synergic control of the hand during multi-finger force production tasks depends on the hand muscles involved. Healthy subjects performed accurate force production tasks and targeted force pulses while pressing against loops positioned at the level of fingertips, middle phalanges, and proximal phalanges. This varied the involvement of the extrinsic and intrinsic finger flexors. The framework of the uncontrolled manifold (UCM) hypothesis was used to analyze the structure of inter-trial variance, motor equivalence, and anticipatory synergy adjustments prior to the force pulse in the spaces of finger forces and finger modes (hypothetical finger-specific control signals). Subjects showed larger maximal force magnitudes at the proximal site of force production. There were synergies stabilizing total force during steady-state phases across all three sites of force production; no differences were seen across the sites in indices of structure of variance, motor equivalence, or anticipatory synergy adjustments. Indices of variance, which did not affect the task (within the UCM), correlated with motor equivalent motion between the steady states prior to and after the force pulse; in contrast, variance affecting task performance did not correlate with non-motor equivalent motion. The observations are discussed within the framework of hierarchical control with referent coordinates for salient effectors at each level. The findings suggest that multi-finger synergies are defined at the level of abundant transformation between the low-dimensional hand level and higher dimensional finger level while being relatively immune to transformations between the finger level and muscle level. The results also support the scheme of control with two classes of neural variables that define referent coordinates and gains in back-coupling loops between hierarchical control levels.

Percentage body fat ranges associated with metabolic syndrome risk: results based on the third National Health and Nutrition Examination Survey (1988-1994).

PubMed

Zhu, Shankuan; Wang, ZiMian; Shen, Wei; Heymsfield, Steven B; Heshka, Stanley

2003-08-01

Increasing attention has focused on the association between body fatness and related metabolic risk factors. The quantitative link between percentage body fat (%BF) and the risk of metabolic syndrome is unknown. The objectives were to determine the risk [odds ratios (ORs)] of metabolic syndrome based on %BF in black and white men and women in the United States and to provide corresponding ranges of %BF associated with a risk equivalent to body mass index (BMI; in kg/m(2)). The subjects were participants in the third National Health and Nutrition Examination Survey and were divided into those with and without the metabolic syndrome. OR equations were derived from logistic regression models for %BF and BMI, with the 25th percentile in the study population as the reference. Ranges were developed by associating %BF with the equivalent risk of metabolic syndrome based on established BMI cutoffs. Four sets (men, women, black, and white) of OR curves were generated for %BF and for BMI by using data from 8259 adults. The ORs for metabolic syndrome were lower in blacks than in whites at any given %BF or BMI. The developed cutoffs for %BF differed between men and women but showed only small race and age effects. A simplified set of sex-specific %BF ranges for the risk of metabolic syndrome were developed. The risk of metabolic syndrome can be established from measured %BF by using either the developed OR curves or %BF thresholds at traditional BMI cutoffs. This information should prove useful in both clinical and research settings.

Determining Intensity Levels of Selected Wii Fit Activities in College Aged Individuals

ERIC Educational Resources Information Center

Grieser, Joshua D.; Gao, Yong; Ransdell, Lynda; Simonson, Shawn

2012-01-01

The purpose of this study was to determine the intensity of Nintendo Wii Fit games using indirect calorimetry. Twenty-five college students completed Wii Fit activity sessions at two difficulty levels within aerobics, strength, and yoga categories. Resting metabolic rate and exercise oxygen uptake were measured, and metabolic equivalents were…

Nocturnal Accumulation of Malic Acid Occurs in Mesophyll Tissue without Proton Transport to Epidermal Tissue in the Inducible Crassulacean Acid Metabolism Plant Mesembryanthemum crystallinum1

PubMed Central

Winter, Klaus; Edwards, Gerald E.; Holtum, Joseph A. M.

1981-01-01

The inducible Crassulacean acid metabolism plant, Mesembryanthemum crystallinum, accumulates malic acid, i.e. equivalent amounts of malate anions and protons in the mesophyll cells at night. Levels of malate and titratable acidity are low in the epidermal tissue and do not change significantly during the day/night cycle. This result is in contrast to a recent report (Bloom 1979 Plant Physiol 64: 919-923) that the synthesis of malic acid during dark CO2 fixation is associated with an equivalent exchange of inorganic cations from epidermal tissue with protons in the mesophyll cells. PMID:16661916

Articulating Syntactic and Numeric Perspectives on Equivalence: The Case of Rational Expressions

ERIC Educational Resources Information Center

Solares, Armando; Kieran, Carolyn

2013-01-01

Our study concerns the conceptual mathematical knowledge that emerges during the resolution of tasks on the equivalence of polynomial and rational algebraic expressions, by using CAS and paper-and-pencil techniques. The theoretical framework we adopt is the Anthropological Theory of Didactics ("Chevallard" 19:221-266, 1999), in…

Overview of crew member energy expenditure during Shuttle Flight 61-8 EASE/ACCESS task performance

NASA Technical Reports Server (NTRS)

Horrigan, D. J.; Waligora, J. W.; Stanford, J.; Edwards, B. F.

1987-01-01

The energy expenditure of the Shuttle Flight 61-B crewmembers during the extravehicular performance of Experimental Assembly of Structures in EVA (EASE) and Assembly Concept of Construction of Space Structures (ACCESS) construction system tasks are reported. These data consist of metabolic rate time profiles correlated with specific EASE and ACCESS tasks and crew comments. Average extravehicular activity metabolic rates are computed and compared with those reported from previous Apollo, Shylab, and Shuttle flights. These data reflect total energy expenditure and not that of individual muscle groups such as hand and forearm. When correlated with specific EVA tasks and subtasks, the metabolic profile data is expected to be useful in planning future EVA protocols. For example, after experiencing high work rates and apparent overheating during some Gemini EVAs, it was found useful to carefully monitor work rates in subsequent flights to assess the adequacy of cooling garments and as an aid to preplanning EVA procedures. This presentation is represented by graphs and charts.

New head equivalent phantom for task and image performance evaluation representative for neurovascular procedures occurring in the Circle of Willis

NASA Astrophysics Data System (ADS)

Ionita, Ciprian N.; Loughran, Brendan; Jain, Amit; Swetadri Vasan, S. N.; Bednarek, Daniel R.; Levy, Elad; Siddiqui, Adnan H.; Snyder, Kenneth V.; Hopkins, L. N.; Rudin, Stephen

2012-03-01

Phantom equivalents of different human anatomical parts are routinely used for imaging system evaluation or dose calculations. The various recommendations on the generic phantom structure given by organizations such as the AAPM, are not always accurate when evaluating a very specific task. When we compared the AAPM head phantom containing 3 mm of aluminum to actual neuro-endovascular image guided interventions (neuro-EIGI) occurring in the Circle of Willis, we found that the system automatic exposure rate control (AERC) significantly underestimated the x-ray parameter selection. To build a more accurate phantom for neuro-EIGI, we reevaluated the amount of aluminum which must be included in the phantom. Human skulls were imaged at different angles, using various angiographic exposures, at kV's relevant to neuro-angiography. An aluminum step wedge was also imaged under identical conditions, and a correlation between the gray values of the imaged skulls and those of the aluminum step thicknesses was established. The average equivalent aluminum thickness for the skull samples for frontal projections in the Circle of Willis region was found to be about 13 mm. The results showed no significant changes in the average equivalent aluminum thickness with kV or mAs variation. When a uniform phantom using 13 mm aluminum and 15 cm acrylic was compared with an anthropomorphic head phantom the x-ray parameters selected by the AERC system were practically identical. These new findings indicate that for this specific task, the amount of aluminum included in the head equivalent must be increased substantially from 3 mm to a value of 13 mm.

Joint Identification of Genetic Variants for Physical Activity in Korean Population

PubMed Central

Kim, Jayoun; Kim, Jaehee; Min, Haesook; Oh, Sohee; Kim, Yeonjung; Lee, Andy H.; Park, Taesung

2014-01-01

There has been limited research on genome-wide association with physical activity (PA). This study ascertained genetic associations between PA and 344,893 single nucleotide polymorphism (SNP) markers in 8842 Korean samples. PA data were obtained from a validated questionnaire that included information on PA intensity and duration. Metabolic equivalent of tasks were calculated to estimate the total daily PA level for each individual. In addition to single- and multiple-SNP association tests, a pathway enrichment analysis was performed to identify the biological significance of SNP markers. Although no significant SNP was found at genome-wide significance level via single-SNP association tests, 59 genetic variants mapped to 76 genes were identified via a multiple SNP approach using a bootstrap selection stability measure. Pathway analysis for these 59 variants showed that maturity onset diabetes of the young (MODY) was enriched. Joint identification of SNPs could enable the identification of multiple SNPs with good predictive power for PA and a pathway enriched for PA. PMID:25026172

Dynamic Characteristics of Ventilatory and Gas Exchange during Sinusoidal Walking in Humans.

PubMed

Fukuoka, Yoshiyuki; Iihoshi, Masaaki; Nazunin, Juhelee Tuba; Abe, Daijiro; Fukuba, Yoshiyuki

2017-01-01

Our present study investigated whether the ventilatory and gas exchange responses show different dynamics in response to sinusoidal change in cycle work rate or walking speed even if the metabolic demand was equivalent in both types of exercise. Locomotive parameters (stride length and step frequency), breath-by-breath ventilation (V̇E) and gas exchange (CO2 output (V̇CO2) and O2 uptake (V̇O2)) responses were measured in 10 healthy young participants. The speed of the treadmill was sinusoidally changed between 3 km·h-1 and 6 km·h-1 with various periods (from 10 to 1 min). The amplitude of locomotive parameters against sinusoidal variation showed a constant gain with a small phase shift, being independent of the oscillation periods. In marked contrast, when the periods of the speed oscillations were shortened, the amplitude of V̇E decreased sharply whereas the phase shift of V̇E increased. In comparing walking and cycling at the equivalent metabolic demand, the amplitude of V̇E during sinusoidal walking (SW) was significantly greater than that during sinusoidal cycling (SC), and the phase shift became smaller. The steeper slope of linear regression for the V̇E amplitude ratio to V̇CO2 amplitude ratio was observed during SW than SC. These findings suggested that the greater amplitude and smaller phase shift of ventilatory dynamics were not equivalent between SW and SC even if the metabolic demand was equivalent between both exercises. Such phenomenon would be derived from central command in proportion to locomotor muscle recruitment (feedforward) and muscle afferent feedback.

Validated Predictions of Metabolic Energy Consumption for Submaximal Effort Movement

PubMed Central

Tsianos, George A.; MacFadden, Lisa N.

2016-01-01

Physical performance emerges from complex interactions among many physiological systems that are largely driven by the metabolic energy demanded. Quantifying metabolic demand is an essential step for revealing the many mechanisms of physical performance decrement, but accurate predictive models do not exist. The goal of this study was to investigate if a recently developed model of muscle energetics and force could be extended to reproduce the kinematics, kinetics, and metabolic demand of submaximal effort movement. Upright dynamic knee extension against various levels of ergometer load was simulated. Task energetics were estimated by combining the model of muscle contraction with validated models of lower limb musculotendon paths and segment dynamics. A genetic algorithm was used to compute the muscle excitations that reproduced the movement with the lowest energetic cost, which was determined to be an appropriate criterion for this task. Model predictions of oxygen uptake rate (VO2) were well within experimental variability for the range over which the model parameters were confidently known. The model's accurate estimates of metabolic demand make it useful for assessing the likelihood and severity of physical performance decrement for a given task as well as investigating underlying physiologic mechanisms. PMID:27248429

Structure and Content in Social Cognition: Conceptual and Empirical Analyses.

ERIC Educational Resources Information Center

Edelstein, Wolfgang; And Others

1984-01-01

Conceptual analysis of two perspective-taking tasks identified a number of subtasks calling for equivalent operations of social reasoning within tasks of different content. Subtasks hypothetically formed a logical and developmental sequence of abilities required for decentering. The developmental significance of the hierarchy was tested among 121…

How Cross-Language Similarity and Task Demands Affect Cognate Recognition

ERIC Educational Resources Information Center

Dijkstra, Ton; Miwa, Koji; Brummelhuis, Bianca; Sappelli, Maya; Baayen, Harald

2010-01-01

This study examines how the cross-linguistic similarity of translation equivalents affects bilingual word recognition. Performing one of three tasks, Dutch-English bilinguals processed cognates with varying degrees of form overlap between their English and Dutch counterparts (e.g., "lamp-lamp" vs. "flood-vloed" vs. "song-lied"). In lexical…

Phonological Coding in Good and Poor Readers.

ERIC Educational Resources Information Center

Briggs, Pamela; Underwood, Geoffrey

1982-01-01

A set of four experiments investigates the relationship between phonological coding and reading ability, using a picture-word interference task and a decoding task. Results with regard to both adults and children suggest that while poor readers possess weak decoding skills, good and poor readers show equivalent evidence of direct semantic and…

Assessment of image quality in soft tissue and bone visualization tasks for a dedicated extremity cone-beam CT system.

PubMed

Demehri, S; Muhit, A; Zbijewski, W; Stayman, J W; Yorkston, J; Packard, N; Senn, R; Yang, D; Foos, D; Thawait, G K; Fayad, L M; Chhabra, A; Carrino, J A; Siewerdsen, J H

2015-06-01

To assess visualization tasks using cone-beam CT (CBCT) compared to multi-detector CT (MDCT) for musculoskeletal extremity imaging. Ten cadaveric hands and ten knees were examined using a dedicated CBCT prototype and a clinical multi-detector CT using nominal protocols (80 kVp-108mAs for CBCT; 120 kVp- 300 mAs for MDCT). Soft tissue and bone visualization tasks were assessed by four radiologists using five-point satisfaction (for CBCT and MDCT individually) and five-point preference (side-by-side CBCT versus MDCT image quality comparison) rating tests. Ratings were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests, and observer agreement was assessed using the Kappa-statistic. Knee CBCT images were rated "excellent" or "good" (median scores 5 and 4) for "bone" and "soft tissue" visualization tasks. Hand CBCT images were rated "excellent" or "adequate" (median scores 5 and 3) for "bone" and "soft tissue" visualization tasks. Preference tests rated CBCT equivalent or superior to MDCT for bone visualization and favoured the MDCT for soft tissue visualization tasks. Intraobserver agreement for CBCT satisfaction tests was fair to almost perfect (κ ~ 0.26-0.92), and interobserver agreement was fair to moderate (κ ~ 0.27-0.54). CBCT provided excellent image quality for bone visualization and adequate image quality for soft tissue visualization tasks. • CBCT provided adequate image quality for diagnostic tasks in extremity imaging. • CBCT images were "excellent" for "bone" and "good/adequate" for "soft tissue" visualization tasks. • CBCT image quality was equivalent/superior to MDCT for bone visualization tasks.

Revisiting Evidence for Modularity and Functional Equivalence across Verbal and Spatial Domains in Memory

ERIC Educational Resources Information Center

Guerard, Katherine; Tremblay, Sebastien

2008-01-01

The authors revisited evidence in favor of modularity and of functional equivalence between the processing of verbal and spatial information in short-term memory. This was done by investigating the patterns of intrusions, omissions, transpositions, and fill-ins in verbal and spatial serial recall and order reconstruction tasks under control,…

Frequency of Input and L2 Collocational Processing: A Comparison of Congruent and Incongruent Collocations

ERIC Educational Resources Information Center

Wolter, Brent; Gyllstad, Henrik

2013-01-01

This study investigated the influence of frequency effects on the processing of congruent (i.e., having an equivalent first language [L1] construction) collocations and incongruent (i.e., not having an equivalent L1 construction) collocations in a second language (L2). An acceptability judgment task was administered to native and advanced…

Locating Basic Spanish Colour Categories in CIE L*u*v* Space: Identification, Lightness Segregation and Correspondence with English Equivalents

ERIC Educational Resources Information Center

Lillo, Julio; Moreira, Humberto; Vitini, Isaac; Martin, Jesus

2007-01-01

Five experiments were performed to identify the basic Spanish colour categories (BCCs) and to locate them in the CIE L*u*v* space. The existence of 11 BCCs was confirmed using an elicited list task and a free monolexemic naming task. From the results provided by a synonymicity estimation task, it was concluded that, in Spanish, 2 synonymous terms…

Holistic Processing in the Composite Task Depends on Face Size.

PubMed

Ross, David A; Gauthier, Isabel

Holistic processing is a hallmark of face processing. There is evidence that holistic processing is strongest for faces at identification distance, 2 - 10 meters from the observer. However, this evidence is based on tasks that have been little used in the literature and that are indirect measures of holistic processing. We use the composite task- a well validated and frequently used paradigm - to measure the effect of viewing distance on holistic processing. In line with previous work, we find a congruency x alignment effect that is strongest for faces that are close (2m equivalent distance) than for faces that are further away (24m equivalent distance). In contrast, the alignment effect for same trials, used by several authors to measure holistic processing, produced results that are difficult to interpret. We conclude that our results converge with previous findings providing more direct evidence for an effect of size on holistic processing.

Prospective, randomized assessment of transfer of training (ToT) and transfer effectiveness ratio (TER) of virtual reality simulation training for laparoscopic skill acquisition.

PubMed

Gallagher, Anthony G; Seymour, Neal E; Jordan-Black, Julie-Anne; Bunting, Brendan P; McGlade, Kieran; Satava, Richard Martin

2013-06-01

We assessed the effectiveness of ToT from VR laparoscopic simulation training in 2 studies. In a second study, we also assessed the TER. ToT is a detectable performance improvement between equivalent groups, and TER is the observed percentage performance differences between 2 matched groups carrying out the same task but with 1 group pretrained on VR simulation. Concordance between simulated and in-vivo procedure performance was also assessed. Prospective, randomized, and blinded. In Study 1, experienced laparoscopic surgeons (n = 195) and in Study 2 laparoscopic novices (n = 30) were randomized to either train on VR simulation before completing an equivalent real-world task or complete the real-world task only. Experienced laparoscopic surgeons and novices who trained on the simulator performed significantly better than their controls, thus demonstrating ToT. Their performance showed a TER between 7% and 42% from the virtual to the real tasks. Simulation training impacted most on procedural error reduction in both studies (32-42%). The correlation observed between the VR and real-world task performance was r > 0·96 (Study 2). VR simulation training offers a powerful and effective platform for training safer skills.

CHD risk equivalents and the metabolic syndrome. Trial evidence supports aggressive management.

PubMed

Thompson, Paul D

2003-08-01

Updated guidelines issued by the National Cholesterol Education Program's 2001 Adult Treatment Panel III (ATP III) reaffirm the importance of intensive management of low density lipoprotein cholesterol (LDL-C) in patients with established coronary heart disease (CHD). Clinical studies also show that diabetes, peripheral arterial disease, abdominal aortic aneurysm, and symptomatic carotid artery disease are CHD risk equivalents that require intensive therapeutic lifestyle changes and drug therapy to prevent associated morbidity and mortality. Likewise, the metabolic syndrome is a secondary target of treatment. Drug therapy usually starts with an LDL-C-lowering agent, such as a statin. If LDL-C and non-high-density lipoprotein cholesterol goals are not achieved, statin therapy should be intensified or a fibrate or niacin should be added.

Emergence of relations and the essence of learning: a review of Sidman's Equivalence relations and behavior: a research story. Book review

NASA Technical Reports Server (NTRS)

Rumbaugh, D. M.

1995-01-01

The author reviews and comments on the book Equivalence relations and behavior: a research story by Murray Sidman. Sidman's book reports his research about equivalence relations and competencies in children with mental retardation and how it relates to behavior. Sidman used the idea of stimulus-stimulus relations among features of the environment to develop his theories about equivalence relations. Experimental work with children and animals demonstrated their ability to use equivalence relations to learn new tasks. The subject received feedback and reinforcement for specific choices made during training, then was presented with new choices during testing. Results of the tests indicate that subjects were able to establish relations and retrieve them in different situations.

Sugar-Sweetened Beverage Intake and Cancer Recurrence and Survival in CALGB 89803 (Alliance)

PubMed Central

Fuchs, Michael A.; Sato, Kaori; Niedzwiecki, Donna; Ye, Xing; Saltz, Leonard B.; Mayer, Robert J.; Mowat, Rex B.; Whittom, Renaud; Hantel, Alexander; Benson, Al; Atienza, Daniel; Messino, Michael; Kindler, Hedy; Venook, Alan; Ogino, Shuji; Wu, Kana; Willett, Walter C.; Giovannucci, Edward L.; Meyerhardt, Jeffrey A.

2014-01-01

Background In colon cancer patients, obesity, sedentary lifestyle, and high dietary glycemic load have been associated with increased risk of cancer recurrence. High sugar-sweetened beverage intake has been associated with obesity, diabetes, and cardio-metabolic diseases, but the influence on colon cancer survival is unknown. Methods We assessed the association between sugar-sweetened beverage consumption on cancer recurrence and mortality in 1,011 stage III colon cancer patients who completed food frequency questionnaires as part of a U.S. National Cancer Institute-sponsored adjuvant chemotherapy trial. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with Cox proportional hazard models. Results Patients consuming ≥2 servings of sugar-sweetened beverages per day experienced an adjusted HR for disease recurrence or mortality of 1.67 (95% CI, 1.04–2.68), compared with those consuming <2 servings per month (P trend = 0.02). The association of sugar-sweetened beverages on cancer recurrence or mortality appeared greater among patients who were both overweight (body mass index ≥25 kg/m2) and less physically active (metabolic equivalent task-hours per week <18) (HR = 2.22; 95% CI, 1.29–3.81, P trend = 0.0025). Conclusion Higher sugar-sweetened beverage intake was associated with a significantly increased risk of cancer recurrence and mortality in stage III colon cancer patients. PMID:24937507

Measurement of functional capacity requirements to aid in development of an occupation-specific rehabilitation training program to help firefighters with cardiac disease safely return to work.

PubMed

Adams, Jenny; Roberts, Joanne; Simms, Kay; Cheng, Dunlei; Hartman, Julie; Bartlett, Charles

2009-03-15

We designed a study to measure the functional capacity requirements of firefighters to aid in the development of an occupation-specific training program in cardiac rehabilitation; 23 healthy male firefighters with no history of heart disease completed a fire and rescue obstacle course that simulated 7 common firefighting tasks. They wore complete personal protective equipment and portable metabolic instruments that included a data collection mask. We monitored each subject's oxygen consumption (VO(2)) and working heart rate, then calculated age-predicted maximum heart rates (220 - age) and training target heart rates (85% of age-predicted maximum heart rate). During performance of the obstacle course, the subjects' mean working heart rates and peak heart rates were higher than the calculated training target heart rates (t(22) = 5.69 [working vs target, p <0.001] and t(22) = 15.14 [peak vs target, p <0.001]). These findings, with mean results for peak VO(2) (3,447 ml/min) and metabolic equivalents (11.9 METs), show that our subjects' functional capacity greatly exceeded that typically attained by patients in traditional cardiac rehabilitation programs (5 to 8 METs). In conclusion, our results indicate the need for intense, occupation-specific cardiac rehabilitation training that will help firefighters safely return to work after a cardiac event.

The equivalency between logic Petri workflow nets and workflow nets.

PubMed

Wang, Jing; Yu, ShuXia; Du, YuYue

2015-01-01

Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented.

The Equivalency between Logic Petri Workflow Nets and Workflow Nets

PubMed Central

Wang, Jing; Yu, ShuXia; Du, YuYue

2015-01-01

Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented. PMID:25821845

Correlation between chronotropic incompetence and metabolic equivalents in patients with type 2 diabetes mellitus and concomitant metabolic syndrome.

PubMed

Gao, M; Chen, W; Gong, Z K; Han, L; Zhang, L

2015-09-01

The aim of the study was to examine the relationship between chronotropic incompetence and motor ability in patient with type 2 diabetes mellitus and concomitant metabolic syndrome (MS) in order to facilitate exercise prescriptions for these patients. A total of 120 patients with type 2 diabetes mellitus were randomly enrolled and divided into study groups with (N.=64) or without MS (N.=56). All patients completed the electrocardiographic exercise testing, after which ratio of heart rate (rHR) and heart rate reserve (HRR) were calculating to assess chronotropic incompetence. In addition, maximum metabolic equivalents (maxMETs) were calculated to assess the motor ability. The MS group had significantly higher indicators of chronotropic incompetence (rHR and HRR) as well as maxMETs than patients without MS (all P<0.05). Further, maxMETs significantly correlated with rHR (r=0.81, P=0.003) and HRR (r=0.78, P<0.001). Patients with type 2 diabetes mellitus and concomitant MS have higher chronotropic incompetence and maxMETs compared with those without MS. METs or perceived level of exertion can be used in patients in whom heart rate is not available during the exercise.

Differential Distraction Effects in Short-Term and Long-Term Retention of Pictures and Words

ERIC Educational Resources Information Center

Pellegrino, James W.; And Others

1976-01-01

Comparisons between recall levels following simple acoustic or visual tasks and the simultaneous visual-plus-acoustic task are not based upon equivalent amounts of interference within each modality. This research attempts to test more precisely the relationship between visual and acoustic interference by using a sequential rather than a…

Child Proportional Scaling: Is 1/3 = 2/6 = 3/9 = 4/12?

ERIC Educational Resources Information Center

Boyer, Ty W.; Levine, Susan C.

2012-01-01

The current experiments examined the role of scale factor in children's proportional reasoning. Experiment 1 used a choice task and Experiment 2 used a production task to examine the abilities of kindergartners through fourth-graders to match equivalent, visually depicted proportional relations. The findings of both experiments show that accuracy…

The equivalent internal orientation and position noise for contour integration.

PubMed

Baldwin, Alex S; Fu, Minnie; Farivar, Reza; Hess, Robert F

2017-10-12

Contour integration is the joining-up of local responses to parts of a contour into a continuous percept. In typical studies observers detect contours formed of discrete wavelets, presented against a background of random wavelets. This measures performance for detecting contours in the limiting external noise that background provides. Our novel task measures contour integration without requiring any background noise. This allowed us to perform noise-masking experiments using orientation and position noise. From these we measure the equivalent internal noise for contour integration. We found an orientation noise of 6° and position noise of 3 arcmin. Orientation noise was 2.6x higher in contour integration compared to an orientation discrimination control task. Comparing against a position discrimination task found position noise in contours to be 2.4x lower. This suggests contour integration involves intermediate processing that enhances the quality of element position representation at the expense of element orientation. Efficiency relative to the ideal observer was lower for the contour tasks (36% in orientation noise, 21% in position noise) compared to the controls (54% and 57%).

Task and work performance on Skylab missions 2, 3, and 4: Time and motion study: Experiment M151

NASA Technical Reports Server (NTRS)

Kubis, J. F.; Mclaughlin, E. J.; Jackson, J. M.; Rusnak, R.; Mcbride, G. H.; Saxon, S. V.

1977-01-01

Human task performance was evaluated under weightlessness conditions during long duration space flight in order to study the characteristics of the adaptation function. Results show that despite pronounced variability in training schedules and in initial reaction to the Skylab environment, in-flight task performance was relatively equivalent among Skylab crews, and behavioral performance continued to improve from beginning to end of all missions.

Multiple paths in complex tasks

NASA Technical Reports Server (NTRS)

Galanter, Eugene; Wiegand, Thomas; Mark, Gloria

1987-01-01

The relationship between utility judgments of subtask paths and the utility of the task as a whole was examined. The convergent validation procedure is based on the assumption that measurements of the same quantity done with different methods should covary. The utility measures of the subtasks were obtained during the performance of an aircraft flight controller navigation task. Analyses helped decide among various models of subtask utility combination, whether the utility ratings of subtask paths predict the whole tasks utility rating, and indirectly, whether judgmental models need to include the equivalent of cognitive noise.

Cultural adaptation of an instrument to assess physical fitness in cardiac patients.

PubMed

Domingues, Gabriela de Barros Leite; Gallani, Maria Cecília; Gobatto, Claudio Alexandre; Miura, Cinthya Tamie Passos; Rodrigues, Roberta Cunha Matheus; Myers, Jonathan

2011-04-01

To validate the content and to evaluate the reliability of the Veterans Specific Activity Questionnaire instrument, culturally adapted for use in the Brazilian population of cardiac patients. The instrument was translated and back-translated and subsequently analyzed by a committee of judges to evaluate its semantic-idiomatic and cultural equivalences. Physical activities were replaced when indicated in the instrument, but uncommon in the daily life of the target population. Another committee of specialists analyzed the metabolic equivalence of replaced activities. The proportion of agreement of evaluation of the judges was quantified by the Content Validity Index. The pre-test was performed in two stages (n1 and n2=15). Reliability was assessed using the test-retest (interval of 7-15 days, n = 50). In the evaluation of semantic-idiomatic and cultural equivalences, items with a Content Validity Index < 1 were reviewed until consensus among the judges was obtained. The second committee found 100% of agreement in the analysis of metabolic equivalence between original and replaced activities. Test-retest analysis indicated a Kappa coefficient of agreement (k = 0.86; (p<0.001), suggesting temporal stability of the instrument. The Brazilian version of the Veterans Specific Activity Questionnaire showed evidence of reliability, according to the temporal stability criterion and adequate cultural content.

Comprehensive Evaluation of Altered Systemic Metabolism and Pancreatic Cancer Risk

DTIC Science & Technology

2016-10-01

To explore altered metabolism is patients with pancreatic cancer, we are conducting studies in participants from four large prospective cohorts, where...participants from four large prospective cohorts, where individuals provide extensive data on metabolic phenotypes, such as obesity and diabetes, and...Pancreatic cancer; Metabolism; Early detection ACCOMPLISHMENTS: What were the major goals of the project? Four major tasks were described

Frontal brain activation during a working memory task: a time-domain fNIRS study

NASA Astrophysics Data System (ADS)

Molteni, E.; Baselli, G.; Bianchi, A. M.; Caffini, M.; Contini, D.; Spinelli, L.; Torricelli, A.; Cerutti, S.; Cubeddu, R.

2009-02-01

We evaluated frontal brain activation during a working memory task with graded levels of difficulty in a group of 19 healthy subjects, by means of time-resolved fNIRS technique. Brain activation was computed, and was then separated into a "block-related" and a "tonic" components. Load-related increases of blood oxygenation were studied for the four different levels of task difficulty. Generalized Linear Models were applied to the data in order to explore the metabolic processes occurring during the mental effort and, possibly, their involvement in short term memorization. Results attest the presence of a persistent attentional-related metabolic activity, superimposed to a task-related mnemonic contribution. Moreover, a systemic component probably deriving from the extra-cerebral capillary bed was detected.

Goal equivalent manifold analysis of task performance in non-specific LBP and healthy subjects during repetitive trunk movement: Effect of load, velocity, symmetry.

PubMed

Chehrehrazi, Mahshid; Sanjari, Mohammad Ali; Mokhtarinia, Hamid Reza; Jamshidi, Ali Ashraf; Maroufi, Nader; Parnianpour, Mohamad

2017-01-01

Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions. Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP). Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading; each at two levels. A goal function for the task was defined as maintaining a constant movement time at each cycle. Given the GEM, flexibility index and performance index were calculated respectively as amounts of goal-equivalent variability and the ratio of goal-equivalent to non-goal-equivalent variability. CNSLBP group was as similar as healthy individuals in both flexibility index (p=0.41) and performance index (p=0.24). Performance index was higher in asymmetric (p<0.001), high velocity (p<0.001), and loaded (p=0.006) conditions. Performance and flexibility in using motor abundance were influenced by repeated trunk flexion/extension conditions. However, these measures were not significantly affected by CNSLBP. Copyright © 2016 Elsevier B.V. All rights reserved.

Cardiovascular and metabolic activity at rest and during psychological and physical challenge in normotensives and subjects with mildly elevated blood pressure.

PubMed

Sims, J; Carroll, D

1990-03-01

Heart rate, systolic and diastolic blood pressure, and respiratory and metabolic activity were recorded prior to and during mental arithmetic and a video game task in 20 young men with mildly elevated casual systolic blood pressures. Twenty-five unambiguously normotensive young men were tested under the same protocol. For pretask baseline physiological activity, group differences emerged for all cardiovascular and metabolic variables; thus the elevated blood pressure group displayed not only higher resting cardiovascular levels than normotensive subjects, but higher levels of metabolic activity too. With regard to change in physiological activity from rest to task, the group with mildly elevated blood pressure showed reliably larger increases in heart rate to the mental arithmetic task than the normotensive subjects. These effects, however, were not paralleled by group differences in metabolic activity increase. Physiological measures were also taken prior to and during graded dynamic exercise. The subsequent calculation of individual heart rate-oxygen consumption exercise regression lines allowed the comparison of actual and predicted heart rates during psychological challenge. The subjects with mildly elevated blood pressure displayed significantly greater discrepancies between actual and predicted heart rate values than normotensives during the psychological tasks in general and mental arithmetic in particular. Group differences in physiological activity during exercise largely reflected the pattern seen at rest. A possible exception here was systolic blood pressure. Not only were systolic blood pressure levels higher throughout the exercise phase for mildly elevated blood pressure subjects, but this group evidenced more of an increase from rest to exercise than the normotensives.

Decision-Making under Ambiguity Is Modulated by Visual Framing, but Not by Motor vs. Non-Motor Context. Experiments and an Information-Theoretic Ambiguity Model

PubMed Central

Grau-Moya, Jordi; Ortega, Pedro A.; Braun, Daniel A.

2016-01-01

A number of recent studies have investigated differences in human choice behavior depending on task framing, especially comparing economic decision-making to choice behavior in equivalent sensorimotor tasks. Here we test whether decision-making under ambiguity exhibits effects of task framing in motor vs. non-motor context. In a first experiment, we designed an experience-based urn task with varying degrees of ambiguity and an equivalent motor task where subjects chose between hitting partially occluded targets. In a second experiment, we controlled for the different stimulus design in the two tasks by introducing an urn task with bar stimuli matching those in the motor task. We found ambiguity attitudes to be mainly influenced by stimulus design. In particular, we found that the same subjects tended to be ambiguity-preferring when choosing between ambiguous bar stimuli, but ambiguity-avoiding when choosing between ambiguous urn sample stimuli. In contrast, subjects’ choice pattern was not affected by changing from a target hitting task to a non-motor context when keeping the stimulus design unchanged. In both tasks subjects’ choice behavior was continuously modulated by the degree of ambiguity. We show that this modulation of behavior can be explained by an information-theoretic model of ambiguity that generalizes Bayes-optimal decision-making by combining Bayesian inference with robust decision-making under model uncertainty. Our results demonstrate the benefits of information-theoretic models of decision-making under varying degrees of ambiguity for a given context, but also demonstrate the sensitivity of ambiguity attitudes across contexts that theoretical models struggle to explain. PMID:27124723

Decision-Making under Ambiguity Is Modulated by Visual Framing, but Not by Motor vs. Non-Motor Context. Experiments and an Information-Theoretic Ambiguity Model.

PubMed

Grau-Moya, Jordi; Ortega, Pedro A; Braun, Daniel A

2016-01-01

A number of recent studies have investigated differences in human choice behavior depending on task framing, especially comparing economic decision-making to choice behavior in equivalent sensorimotor tasks. Here we test whether decision-making under ambiguity exhibits effects of task framing in motor vs. non-motor context. In a first experiment, we designed an experience-based urn task with varying degrees of ambiguity and an equivalent motor task where subjects chose between hitting partially occluded targets. In a second experiment, we controlled for the different stimulus design in the two tasks by introducing an urn task with bar stimuli matching those in the motor task. We found ambiguity attitudes to be mainly influenced by stimulus design. In particular, we found that the same subjects tended to be ambiguity-preferring when choosing between ambiguous bar stimuli, but ambiguity-avoiding when choosing between ambiguous urn sample stimuli. In contrast, subjects' choice pattern was not affected by changing from a target hitting task to a non-motor context when keeping the stimulus design unchanged. In both tasks subjects' choice behavior was continuously modulated by the degree of ambiguity. We show that this modulation of behavior can be explained by an information-theoretic model of ambiguity that generalizes Bayes-optimal decision-making by combining Bayesian inference with robust decision-making under model uncertainty. Our results demonstrate the benefits of information-theoretic models of decision-making under varying degrees of ambiguity for a given context, but also demonstrate the sensitivity of ambiguity attitudes across contexts that theoretical models struggle to explain.

Genome-based Modeling and Design of Metabolic Interactions in Microbial Communities

PubMed Central

Mahadevan, Radhakrishnan; Henson, Michael A.

2012-01-01

Biotechnology research is traditionally focused on individual microbial strains that are perceived to have the necessary metabolic functions, or the capability to have these functions introduced, to achieve a particular task. For many important applications, the development of such omnipotent microbes is an extremely challenging if not impossible task. By contrast, nature employs a radically different strategy based on synergistic combinations of different microbial species that collectively achieve the desired task. These natural communities have evolved to exploit the native metabolic capabilities of each species and are highly adaptive to changes in their environments. However, microbial communities have proven difficult to study due to a lack of suitable experimental and computational tools. With the advent of genome sequencing, omics technologies, bioinformatics and genome-scale modeling, researchers now have unprecedented capabilities to analyze and engineer the metabolism of microbial communities. The goal of this review is to summarize recent applications of genome-scale metabolic modeling to microbial communities. A brief introduction to lumped community models is used to motivate the need for genome-level descriptions of individual species and their metabolic interactions. The review of genome-scale models begins with static modeling approaches, which are appropriate for communities where the extracellular environment can be assumed to be time invariant or slowly varying. Dynamic extensions of the static modeling approach are described, and then applications of genome-scale models for design of synthetic microbial communities are reviewed. The review concludes with a summary of metagenomic tools for analyzing community metabolism and an outlook for future research. PMID:24688668

Genome-based Modeling and Design of Metabolic Interactions in Microbial Communities.

PubMed

Mahadevan, Radhakrishnan; Henson, Michael A

2012-01-01

Biotechnology research is traditionally focused on individual microbial strains that are perceived to have the necessary metabolic functions, or the capability to have these functions introduced, to achieve a particular task. For many important applications, the development of such omnipotent microbes is an extremely challenging if not impossible task. By contrast, nature employs a radically different strategy based on synergistic combinations of different microbial species that collectively achieve the desired task. These natural communities have evolved to exploit the native metabolic capabilities of each species and are highly adaptive to changes in their environments. However, microbial communities have proven difficult to study due to a lack of suitable experimental and computational tools. With the advent of genome sequencing, omics technologies, bioinformatics and genome-scale modeling, researchers now have unprecedented capabilities to analyze and engineer the metabolism of microbial communities. The goal of this review is to summarize recent applications of genome-scale metabolic modeling to microbial communities. A brief introduction to lumped community models is used to motivate the need for genome-level descriptions of individual species and their metabolic interactions. The review of genome-scale models begins with static modeling approaches, which are appropriate for communities where the extracellular environment can be assumed to be time invariant or slowly varying. Dynamic extensions of the static modeling approach are described, and then applications of genome-scale models for design of synthetic microbial communities are reviewed. The review concludes with a summary of metagenomic tools for analyzing community metabolism and an outlook for future research.

MTBE inhaled alone and in combination with gasoline vapor: uptake, distribution, metabolism, and excretion in rats.

PubMed

Benson, J M; Barr, E B; Krone, J R

2001-05-01

The purpose of these studies was to extend previous evaluation of methyl tert-butyl ether (MTBE)* tissue distribution, metabolism, and excretion in rats to include concentrations more relevant to human exposure (4 and 40 ppm) and to determine the effects of coinhalation of the volatile fraction of unleaded gasoline on the tissue distribution, metabolism, and excretion of MTBE. Groups of male F344 rats were exposed nose-only for 4 hours to 4, 40, or 400 ppm 14C-MTBE or to 20 or 200 ppm of the light fraction of unleaded gasoline (LFG) containing 4 or 40 ppm 14C-MTBE, respectively. To evaluate the effects of repeated inhalation of LFG on MTBE tissue distribution, metabolism, and excretion, rats were exposed for 4 hours on each of 7 consecutive days to 20 or 200 ppm LFG with MTBE (4 or 40 ppm) followed on the eighth day by a similar exposure to LFG containing 14C-MTBE. Subgroups of rats were evaluated for respiratory parameters, initial body burdens, rates and routes of excretion, and tissue distribution and elimination. The concentrations of MTBE and its chief metabolite, tert-butyl alcohol (TBA), were measured in blood and kidney immediately after exposure, and the major urinary metabolites-2-hydroxyisobutyric acid (IBA) and 2-methyl-1,2-propanediol (2MePD)-were measured in urine. Inhalation of MTBE alone or as a component of LFG had no concentration-dependent effect on respiratory minute volume. The initial body burdens of MTBE equivalents achieved after 4 hours of exposure to MTBE did not increase linearly with exposure concentration. MTBE equivalents rapidly distributed to all tissues examined, with the largest percentages distributed to liver. The observed initial body burden did not increase linearly between 4 and 400 ppm. At 400 ppm, elimination half-times of MTBE equivalents from liver increased and from lung, kidney, and testes decreased compared with the two smaller doses. Furthermore, at 400 ppm the elimination half-time for volatile organic compounds (VOCs) in breath was significantly shorter and the percentage of the initial body burden of MTBE equivalents eliminated as VOCs in breath increased significantly. These changes probably reflect a saturation of blood with MTBE at 400 ppm and strongly suggest that the uptake and fate of MTBE are notably different at exposure concentrations above and below 400 ppm. Single and repeated coexposure to 20 and 200 ppm LFG with MTBE had opposite effects on the total body burden of MTBE equivalents present at the end of exposures compared with those achieved after 4 and 40 ppm MTBE exposures: 20 ppm LFG increased and 200 ppm LFG significantly decreased the burdens of MTBE equivalents present. The effects of coexposure to LFG on blood levels of MTBE equivalents paralleled the effects on body burden. These differences in overall uptake of MTBE equivalents cannot be attributed to alterations of minute volume. The reason for the increase in overall uptake after 20-ppm LFG exposure is not clear. Decreased MTBE absorption (uptake) after single and repeated coexposure to 200 ppm LFG may be due to a decrease in solubility of MTBE in blood caused by inhalation of other hydrocarbons. Investigations on the blood/air partition coefficient of MTBE in the absence and presence of LFG would be needed to confirm this hypothesis. Single and repeated coexposure to either 20 or 200 ppm LFG significantly decreased the percentage of the initial body burden from MTBE equivalents in tissues, including liver, kidney, and testes, immediately and 72 hours after

Assessment of lexical semantic judgment abilities in alcohol-dependent subjects: an fMRI study.

PubMed

Bagga, D; Singh, N; Modi, S; Kumar, P; Bhattacharya, D; Garg, M L; Khushu, S

2013-12-01

Neuropsychological studies have shown that alcohol dependence is associated with neurocognitive deficits in tasks requiring memory, perceptual motor skills, abstraction and problem solving, whereas language skills are relatively spared in alcoholics despite structural abnormalities in the language-related brain regions. To investigate the preserved mechanisms of language processing in alcohol-dependents, functional brain imaging was undertaken in healthy controls (n=18) and alcohol-dependents (n=16) while completing a lexical semantic judgment task in a 3 T MR scanner. Behavioural data indicated that alcohol-dependents took more time than controls for performing the task but there was no significant difference in their response accuracy. fMRI data analysis revealed that while performing the task, the alcoholics showed enhanced activations in left supramarginal gyrus, precuneus bilaterally, left angular gyrus, and left middle temporal gyrus as compared to control subjects. The extensive activations observed in alcoholics as compared to controls suggest that alcoholics recruit additional brain areas to meet the behavioural demands for equivalent task performance. The results are consistent with previous fMRI studies suggesting compensatory mechanisms for the execution of task for showing an equivalent performance or decreased neural efficiency of relevant brain networks. However, on direct comparison of the two groups, the results did not survive correction for multiple comparisons; therefore, the present findings need further exploration.

Leisure-time physical activity and incident metabolic syndrome: a systematic review and dose-response meta-analysis of cohort studies.

PubMed

Zhang, Dongdong; Liu, Xuejiao; Liu, Yu; Sun, Xizhuo; Wang, Bingyuan; Ren, Yongcheng; Zhao, Yang; Zhou, Junmei; Han, Chengyi; Yin, Lei; Zhao, Jingzhi; Shi, Yuanyuan; Zhang, Ming; Hu, Dongsheng

2017-10-01

Leisure-time physical activity (LTPA) has been suggested to reduce risk of metabolic syndrome (MetS). However, a quantitative comprehensive assessment of the dose-response association between LTPA and incident MetS has not been reported. We performed a meta-analysis of studies assessing the risk of MetS with LTPA. MEDLINE via PubMed and EMBase databases were searched for relevant articles published up to March 13, 2017. Random-effects models were used to estimate the summary relative risk (RR) of MetS with LTPA. Restricted cubic splines were used to model the dose-response association. We identified 16 articles (18 studies including 76,699 participants and 13,871 cases of MetS). We found a negative linear association between LTPA and incident MetS, with a reduction of 8% in MetS risk per 10 metabolic equivalent of task (MET) h/week increment. According to the restricted cubic splines model, risk of MetS was reduced 10% with LTPA performed according to the basic guideline-recommended level of 150min of moderate PA (MPA) per week (10METh/week) versus inactivity (RR=0.90, 95% CI 0.86-0.94). It was reduced 20% and 53% with LTPA at twice (20METh/week) and seven times (70METh/week) the basic recommended level (RR=0.80, 95% CI 0.74-0.88 and 0.47, 95% CI 0.34-0.64, respectively). Our findings provide quantitative data suggesting that any amount of LTPA is better than none and that LTPA substantially exceeding the current LTPA guidelines is associated with an additional reduction in MetS risk. Copyright © 2017. Published by Elsevier Inc.

Comparative Biochemistry and Metabolism. Part 1. Carcinogenesis

DTIC Science & Technology

1981-10-01

qualitatively equivalent to administration of a strong alkylating agent ; this may add another consideration to Roberts’ hypothesis, but ultimately the effect...Removal, Arch. Pathol. 12:186-202. Karran, P., T. Lindahl and B. Griffin, (1979), Adaptive Responses to Alkylating Agents Involves Alterative In Situ of...the Adaptive Response to Alkylating Agents , Nature (Lond.) 280:74-76. Ruchirawat, M., (1974), Relationship Between Metabolism and Toxicity of

Behavioral Economics of Cigarette Purchase Tasks: Within-Subject Comparison of Real, Potentially Real, and Hypothetical Cigarettes

PubMed Central

Wilson, A. George; Franck, Christopher T.; Koffarnus, Mikhail N.

2016-01-01

Abstract Introduction: Hypothetical rewards are commonly used in studies of laboratory-based tobacco demand. However, behavioral economic demand procedures require confirmation that the behavior elicited from real and hypothetical reward types are equivalent, and that results attained from these procedures are comparable to other accepted tasks, such as the hypothetical purchase task. Methods: Nineteen smokers were asked to purchase 1 week’s worth of cigarettes that they would consume over the following week either at one price that incrementally increased across four weekly sessions (“real” sessions) or four prices in a single session (“potentially real” session), one of which was randomly chosen to be actualized. At each session, participants also completed a hypothetical cigarette purchase task. After each week, participants reported the number of cigarettes they actually smoked. Results: Demand was found to be equivalent under both the real and potentially real reward conditions but statistically different from the demand captured in the hypothetical purchase task. However, the amounts purchased at specific prices in the hypothetical purchase task were significantly correlated with the amount purchased at comparable prices in the other two tasks (except for the highest price examined in both tasks of $1.00 per cigarette). Number of cigarettes consumed that were obtained outside of the study was correlated with study cigarette price. Conclusions: Combined, these results suggest that purchasing behavior during potentially real sessions (1) was not functionally different from real sessions, (2) imposes fewer costs to the experimenter, and (3) has high levels of both internal and external validity. PMID:26187389

A test of the reward-value hypothesis.

PubMed

Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D

2017-03-01

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.

Asymptomatic peripheral artery disease can limit maximal exercise capacity in chronic obstructive pulmonary disease patients regardless of airflow obstruction and lung hyperinflation.

PubMed

Crisafulli, Ernesto; Scelfo, Chiara; Tzani, Panagiota; Aiello, Marina; Bertorelli, Giuseppina; Chetta, Alfredo

2017-06-01

Background Silent/asymptomatic peripheral artery disease may occur in patients with chronic obstructive pulmonary disease, but it is poorly investigated. The primary aim of this study was to evaluate in chronic obstructive pulmonary disease patients the impact of asymptomatic/silent peripheral artery disease on maximal exercise capacity; the secondary aim was to search for predictors of peripheral artery disease. Methods We prospectively enrolled chronic obstructive pulmonary disease outpatients. Data on anthropometric characteristics, lung function, cardiopulmonary exercise test and ankle-brachial index were recorded. The cut-off of ankle-brachial index used to define patients with peripheral artery disease was ≤0.90. Results We studied 47 patients and found 24 patients (51%) who showed peripheral artery disease. As compared to patients without peripheral artery disease, patients with peripheral artery disease had lower values of peak oxygen uptake, peak workload, energy expenditure (metabolic equivalents) and heart rate recovery, but showed the same degree of airflow obstruction and static and dynamic hyperinflation. In a multivariate linear regression model performed to identify variables predicting metabolic equivalents, ankle-brachial index (β 2.59; 95% confidence interval 0.51-4.67; p = 0.016) was an independent variable. In the search for predictors of peripheral artery disease, heart rate recovery (odds ratio 8.80; 95% confidence interval 1.30-59.35; p = 0.026) increased the risk of peripheral artery disease, whereas metabolic equivalents (odds ratio 0.50; 95% confidence interval 0.26-0.94, p = 0.033) and inhaled corticosteroids+long-acting β 2 agonists (odds ratio 0.13; 95% confidence interval 0.02-0.83; p = 0.030) reduced this risk. Conclusions In chronic obstructive pulmonary disease outpatients, asymptomatic/silent peripheral artery disease affects the maximal exercise capacity regardless of airflow obstruction and lung hyperinflation. A delay of heart rate recovery increase the risk of peripheral artery disease, whereas high values of metabolic equivalents and the use of inhaled corticosteroids+long-acting β 2 agonists reduces this risk.

Creating a Cell Map as an Active-Learning Tool in a Biochemistry Course

ERIC Educational Resources Information Center

Del Bianco, Cristina

2010-01-01

Teaching metabolism to a biochemistry class with diverse academic backgrounds is a challenging task. Often students lack the global perspective that is needed to understand how different metabolic pathways are reciprocally regulated. The classroom activity presented in this article is designed to facilitate the learning of metabolism by having the…

Cerebral glucose metabolic differences in patients with panic disorder

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

Nordahl, T.E.; Semple, W.E.; Gross, M.

Regional glucose metabolic rates were measured in patients with panic disorder during the performance of auditory discrimination. Those regions examined by Reiman and colleagues in their blood flow study of panic disorder were examined with a higher resolution positron emission tomography (PET) scanner and with the tracer (F-18)-2-fluoro-2-deoxyglucose (FDG). In contrast to the blood flow findings of Reiman et al., we did not find global gray metabolic differences between patients with panic disorder and normal controls. Consistent with the findings of Reiman et al., we found hippocampal region asymmetry. We also found metabolic decreases in the left inferior parietal lobulemore » and in the anterior cingulate (trend), as well as an increase in the metabolic rate of the medial orbital frontal cortex (trend) of panic disorder patients. It is unclear whether the continuous performance task (CPT) enhanced or diminished findings that would have been noted in a study performed without task.« less

Representation of numerical magnitude in math-anxious individuals.

PubMed

Colomé, Àngels

2018-01-01

Larger distance effects in high math-anxious individuals (HMA) performing comparison tasks have previously been interpreted as indicating less precise magnitude representation in this population. A recent study by Dietrich, Huber, Moeller, and Klein limited the effects of math anxiety to symbolic comparison, in which they found larger distance effects for HMA, despite equivalent size effects. However, the question of whether distance effects in symbolic comparison reflect the properties of the magnitude representation or decisional processes is currently under debate. This study was designed to further explore the relation between math anxiety and magnitude representation through three different tasks. HMA and low math-anxious individuals (LMA) performed a non-symbolic comparison, in which no group differences were found. Furthermore, we did not replicate previous findings in an Arabic digit comparison, in which HMA individuals showed equivalent distance effects to their LMA peers. Lastly, there were no group differences in a counting Stroop task. Altogether, an explanation of math anxiety differences in terms of less precise magnitude representation is not supported.

Vitamin B6 prevents cognitive impairment in experimental pneumococcal meningitis.

PubMed

Barichello, Tatiana; Generoso, Jaqueline S; Simões, Lutiana R; Ceretta, Renan A; Dominguini, Diogo; Ferrari, Pâmela; Gubert, Carolina; Jornada, Luciano K; Budni, Josiane; Kapczinski, Flávio; Quevedo, João

2014-10-01

Streptococcus pneumoniae is the relevant cause of bacterial meningitis, with a high-mortality rate and long-term neurological sequelae, affecting up to 50% of survivors. Pneumococcal compounds are pro-inflammatory mediators that induce an innate immune response and tryptophan degradation through the kynurenine pathway. Vitamin B6 acts as a cofactor at the active sites of enzymes that catalyze a great number of reactions involved in the metabolism of tryptophan, preventing the accumulation of neurotoxic intermediates. In the present study, we evaluated the effects of vitamin B6 on memory and on brain-derived neurotrophic factor (BDNF) expression in the brain of adult Wistar rats subjected to pneumococcal meningitis. The animals received either 10 µL of artificial cerebral spinal fluid (CSF) or an equivalent volume of S. pneumoniae suspension. The animals were divided into four groups: control, control treated with vitamin B6, meningitis, and meningitis treated with vitamin B6. Ten days after induction, the animals were subjected to behavioral tests: open-field task and step-down inhibitory avoidance task. In the open-field task, there was a significant reduction in both crossing and rearing in the control group, control/B6 group, and meningitis/B6 group compared with the training session, demonstrating habituation memory. However, the meningitis group showed no difference in motor and exploratory activity between training and test sessions, demonstrating memory impairment. In the step-down inhibitory avoidance task, there was a difference between training and test sessions in the control group, control/B6 group, and meningitis/B6 group, demonstrating aversive memory. In the meningitis group, there was no difference between training and test sessions, demonstrating impairment of aversive memory. In the hippocampus, BDNF expression decreased in the meningitis group when compared to the control group; however, adjuvant treatment with vitamin B6 increased BDNF expression in the meningitis group. Thus, vitamin B6 attenuated the memory impairment in animals subjected to pneumococcal meningitis. © 2014 by the Society for Experimental Biology and Medicine.

Cancer metabolism in space and time: Beyond the Warburg effect.

PubMed

Danhier, Pierre; Bański, Piotr; Payen, Valéry L; Grasso, Debora; Ippolito, Luigi; Sonveaux, Pierre; Porporato, Paolo E

2017-08-01

Altered metabolism in cancer cells is pivotal for tumor growth, most notably by providing energy, reducing equivalents and building blocks while several metabolites exert a signaling function promoting tumor growth and progression. A cancer tissue cannot be simply reduced to a bulk of proliferating cells. Tumors are indeed complex and dynamic structures where single cells can heterogeneously perform various biological activities with different metabolic requirements. Because tumors are composed of different types of cells with metabolic activities affected by different spatial and temporal contexts, it is important to address metabolism taking into account cellular and biological heterogeneity. In this review, we describe this heterogeneity also in metabolic fluxes, thus showing the relative contribution of different metabolic activities to tumor progression according to the cellular context. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux. Copyright © 2017 Elsevier B.V. All rights reserved.

The study of urban metabolism and its applications to urban planning and design.

PubMed

Kennedy, C; Pincetl, S; Bunje, P

2011-01-01

Following formative work in the 1970s, disappearance in the 1980s, and reemergence in the 1990s, a chronological review shows that the past decade has witnessed increasing interest in the study of urban metabolism. The review finds that there are two related, non-conflicting, schools of urban metabolism: one following Odum describes metabolism in terms of energy equivalents; while the second more broadly expresses a city's flows of water, materials and nutrients in terms of mass fluxes. Four example applications of urban metabolism studies are discussed: urban sustainability indicators; inputs to urban greenhouse gas emissions calculation; mathematical models of urban metabolism for policy analysis; and as a basis for sustainable urban design. Future directions include fuller integration of social, health and economic indicators into the urban metabolism framework, while tackling the great sustainability challenge of reconstructing cities. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of a Target-Task Problem-Solving Model on Senior Secondary School Students' Performance in Physics

ERIC Educational Resources Information Center

Olaniyan, A. O.; Omosewo, E. O.

2015-01-01

The study investigated the Effects of a Target-Task Problem-Solving Model on Senior Secondary School Students' Performance in Physics. The research design was a quasi-experimental, non-randomized, non-equivalent pretest, post-test using a control group. The study was conducted in two schools purposively selected and involved a total of 120 Senior…

A Special Application of Absolute Value Techniques in Authentic Problem Solving

ERIC Educational Resources Information Center

Stupel, Moshe

2013-01-01

There are at least five different equivalent definitions of the absolute value concept. In instances where the task is an equation or inequality with only one or two absolute value expressions, it is a worthy educational experience for learners to solve the task using each one of the definitions. On the other hand, if more than two absolute value…

The Spectacles through Which I See the Race and IQ Debate

ERIC Educational Resources Information Center

Flynn, James R.

2010-01-01

The ranking of Wechsler subtests in terms of their "g" loadings is equivalent to ranking them in terms of the cognitive complexity of the tasks measured. Lower performing groups do not always fall behind higher performing groups the more complex the task. But that is the general rule, no matter whether the cause of the lower performance…

Remember-Know and Source Memory Instructions Can Qualitatively Change Old-New Recognition Accuracy: The Modality-Match Effect in Recognition Memory

ERIC Educational Resources Information Center

Mulligan, Neil W.; Besken, Miri; Peterson, Daniel

2010-01-01

Remember-Know (RK) and source memory tasks were designed to elucidate processes underlying memory retrieval. As part of more complex judgments, both tests produce a measure of old-new recognition, which is typically treated as equivalent to that derived from a standard recognition task. The present study demonstrates, however, that recognition…

The Four-Three-Four Model: Drawing on Partitioning, Equivalence, and Unit-Forming in a Quotient Sub-Construct Fraction Task

ERIC Educational Resources Information Center

Mitchell, Annie

2012-01-01

This paper demonstrates the explanatory power of Kieren's framework for rational number knowing (1988, 1992, 1993, 1995), renamed here the four-three-four model, by describing the different approaches of Grade 6 students to a quotient context task (sharing three or seven custard tarts between five people) using Kieren's terminology of…

The neural correlates of subjective utility of monetary outcome and probability weight in economic and in motor decision under risk

PubMed Central

Wu, Shih-Wei; Delgado, Mauricio R.; Maloney, Laurence T.

2011-01-01

In decision under risk, people choose between lotteries that contain a list of potential outcomes paired with their probabilities of occurrence. We previously developed a method for translating such lotteries to mathematically equivalent motor lotteries. The probability of each outcome in a motor lottery is determined by the subject’s noise in executing a movement. In this study, we used functional magnetic resonance imaging in humans to compare the neural correlates of monetary outcome and probability in classical lottery tasks where information about probability was explicitly communicated to the subjects and in mathematically equivalent motor lottery tasks where probability was implicit in the subjects’ own motor noise. We found that activity in the medial prefrontal cortex (mPFC) and the posterior cingulate cortex (PCC) quantitatively represent the subjective utility of monetary outcome in both tasks. For probability, we found that the mPFC significantly tracked the distortion of such information in both tasks. Specifically, activity in mPFC represents probability information but not the physical properties of the stimuli correlated with this information. Together, the results demonstrate that mPFC represents probability from two distinct forms of decision under risk. PMID:21677166

The neural correlates of subjective utility of monetary outcome and probability weight in economic and in motor decision under risk.

PubMed

Wu, Shih-Wei; Delgado, Mauricio R; Maloney, Laurence T

2011-06-15

In decision under risk, people choose between lotteries that contain a list of potential outcomes paired with their probabilities of occurrence. We previously developed a method for translating such lotteries to mathematically equivalent "motor lotteries." The probability of each outcome in a motor lottery is determined by the subject's noise in executing a movement. In this study, we used functional magnetic resonance imaging in humans to compare the neural correlates of monetary outcome and probability in classical lottery tasks in which information about probability was explicitly communicated to the subjects and in mathematically equivalent motor lottery tasks in which probability was implicit in the subjects' own motor noise. We found that activity in the medial prefrontal cortex (mPFC) and the posterior cingulate cortex quantitatively represent the subjective utility of monetary outcome in both tasks. For probability, we found that the mPFC significantly tracked the distortion of such information in both tasks. Specifically, activity in mPFC represents probability information but not the physical properties of the stimuli correlated with this information. Together, the results demonstrate that mPFC represents probability from two distinct forms of decision under risk.

The Effect of Music on Exercise Intensity among Children with Autism Spectrum Disorder: A Pilot Study

PubMed Central

Woodman, Ashley C.; Breviglia, Emily; Mori, Yumiko; Golden, Rebecca; Maina, John; Wisniewski, Hannah

2018-01-01

Children with autism spectrum disorder (ASD) are at risk for obesity, commonly have sleep disorders, and exhibit stereotypic behaviors that disrupt their learning. Vigorous levels of exercise have been shown to ameliorate these issues in children with ASD, but little research exists to provide techniques for motivating children with ASD to engage in exercise. The present study examined the effect of music on exercise intensity in a group of 13 elementary school students with ASD. Data were collected across six days during structured (e.g., verbal and physical prompts) and unstructured (e.g., minimal prompting) exercise periods. During these exercise periods, three music conditions were randomized: no music, slow-tempo music, and fast-tempo music. Exercise intensity, measured in Metabolic Equivalent of Tasks by triaxial accelerometers, was greatest during the structured exercise periods and during the slow music condition. Student characteristics moderated the impact of music condition on exercise intensity, such that students with high levels of adaptive behavior or lower levels of maladaptive behavior displayed greater exercise intensity during the fast music condition. PMID:29495354

Modified Active Videogame Play Results in Moderate-Intensity Exercise.

PubMed

Monedero, Javier; McDonnell, Adam C; Keoghan, Melissa; O'Gorman, Donal J

2014-08-01

Large proportions of the population do not meet current American College of Sports Medicine physical activity recommendations, and innovative approaches are required. Most active videogames do not require a significant amount of energy expenditure. The purpose of this study was to determine if modifying an active videogame increased exercise intensity to meet current physical activity recommendations. After completing a maximal oxygen uptake test, participants did a familiarization session on a separate day. Thirteen healthy participants 24.2±3.4 years of age played (1) a sedentary videogame, (2) an active videogame, and (3) a modified active videogame designed to increase physical activity for 46 minutes in a randomized order on separate days. Oxygen uptake, heart rate, heart rate reserve, percentage of maximal heart rate, metabolic equivalents of task, and energy expenditure were significantly higher during the modified active videogame trial than during the active videogame or sedentary videogame trials and also between the active videogame and sedentary videogame. A simple modification to an existing active videogame was sufficient to reach moderate exercise intensity. Active videogames could provide an important option for increasing daily physical activity and reducing sedentary time.

EASE (Experimental Assembly of Structures in EVA) overview of selected results

NASA Technical Reports Server (NTRS)

Akin, David L.

1987-01-01

Experimental Assembly of Structures in EVA (EASE) objectives, experimental protocol, neutral buoyancy simulation, task time distribution, assembly task performance, metabolic rate/biomedical readouts are summarized. This presentation is shown in charts, figures, and graphs.

Verifying the equivalence of representations of the knee joint moment vector from a drop vertical jump task.

PubMed

Nichols, Julia K; O'Reilly, Oliver M

2017-03-01

Biomechanics software programs, such as Visual3D, Nexus, Cortex, and OpenSim, have the capability of generating several distinct component representations for joint moments and forces from motion capture data. These representations include those for orthonormal proximal and distal coordinate systems and a non-orthogonal joint coordinate system. In this article, a method is presented to address the challenging problem of evaluating and verifying the equivalence of these representations. The method accommodates the difficulty that there are two possible sets of non-orthogonal basis vectors that can be used to express a vector in the joint coordinate system and is illuminated using motion capture data from a drop vertical jump task. Copyright © 2016 Elsevier B.V. All rights reserved.

Noticing relevant problem features: activating prior knowledge affects problem solving by guiding encoding

PubMed Central

Crooks, Noelle M.; Alibali, Martha W.

2013-01-01

This study investigated whether activating elements of prior knowledge can influence how problem solvers encode and solve simple mathematical equivalence problems (e.g., 3 + 4 + 5 = 3 + __). Past work has shown that such problems are difficult for elementary school students (McNeil and Alibali, 2000). One possible reason is that children's experiences in math classes may encourage them to think about equations in ways that are ultimately detrimental. Specifically, children learn a set of patterns that are potentially problematic (McNeil and Alibali, 2005a): the perceptual pattern that all equations follow an “operations = answer” format, the conceptual pattern that the equal sign means “calculate the total”, and the procedural pattern that the correct way to solve an equation is to perform all of the given operations on all of the given numbers. Upon viewing an equivalence problem, knowledge of these patterns may be reactivated, leading to incorrect problem solving. We hypothesized that these patterns may negatively affect problem solving by influencing what people encode about a problem. To test this hypothesis in children would require strengthening their misconceptions, and this could be detrimental to their mathematical development. Therefore, we tested this hypothesis in undergraduate participants. Participants completed either control tasks or tasks that activated their knowledge of the three patterns, and were then asked to reconstruct and solve a set of equivalence problems. Participants in the knowledge activation condition encoded the problems less well than control participants. They also made more errors in solving the problems, and their errors resembled the errors children make when solving equivalence problems. Moreover, encoding performance mediated the effect of knowledge activation on equivalence problem solving. Thus, one way in which experience may affect equivalence problem solving is by influencing what students encode about the equations. PMID:24324454

[Rehabilitation for digestive and metabolic diseases. Quo vadis?].

PubMed

Stockbrugger, R; Rosemeyer, D; Armbrecht, U

2010-10-01

The position of rehabilitation in gastroenterology, hepatology and metabolic diseases has changed little in the last 25 years. Initial improvements in quality are oriented more to the content of rehabilitative measures and less to organizational basic conditions. Nevertheless, there is an urgent need for action if rehabilitation medicine is to achieve an equivalent and recognized position in the interaction between primary care and other medical specialties. In this article suggestions for expedient prerequisites and utilization options of rehabilitation in the fields of hepatogastroenterology and metabolism will be presented, which are also oriented to the exemplary implemented concepts from Sweden and The Netherlands.

Multiple memory systems as substrates for multiple decision systems

PubMed Central

Doll, Bradley B.; Shohamy, Daphna; Daw, Nathaniel D.

2014-01-01

It has recently become widely appreciated that value-based decision making is supported by multiple computational strategies. In particular, animal and human behavior in learning tasks appears to include habitual responses described by prominent model-free reinforcement learning (RL) theories, but also more deliberative or goal-directed actions that can be characterized by a different class of theories, model-based RL. The latter theories evaluate actions by using a representation of the contingencies of the task (as with a learned map of a spatial maze), called an “internal model.” Given the evidence of behavioral and neural dissociations between these approaches, they are often characterized as dissociable learning systems, though they likely interact and share common mechanisms. In many respects, this division parallels a longstanding dissociation in cognitive neuroscience between multiple memory systems, describing, at the broadest level, separate systems for declarative and procedural learning. Procedural learning has notable parallels with model-free RL: both involve learning of habits and both are known to depend on parts of the striatum. Declarative memory, by contrast, supports memory for single events or episodes and depends on the hippocampus. The hippocampus is thought to support declarative memory by encoding temporal and spatial relations among stimuli and thus is often referred to as a relational memory system. Such relational encoding is likely to play an important role in learning an internal model, the representation that is central to model-based RL. Thus, insofar as the memory systems represent more general-purpose cognitive mechanisms that might subserve performance on many sorts of tasks including decision making, these parallels raise the question whether the multiple decision systems are served by multiple memory systems, such that one dissociation is grounded in the other. Here we investigated the relationship between model-based RL and relational memory by comparing individual differences across behavioral tasks designed to measure either capacity. Human subjects performed two tasks, a learning and generalization task (acquired equivalence) which involves relational encoding and depends on the hippocampus; and a sequential RL task that could be solved by either a model-based or model-free strategy. We assessed the correlation between subjects’ use of flexible, relational memory, as measured by generalization in the acquired equivalence task, and their differential reliance on either RL strategy in the decision task. We observed a significant positive relationship between generalization and model-based, but not model-free, choice strategies. These results are consistent with the hypothesis that model-based RL, like acquired equivalence, relies on a more general-purpose relational memory system. PMID:24846190

The Effects of Modafinil and Ove-the-Counter Stimulants on Two- and Three- Dimensional Visual Localization

DTIC Science & Technology

2017-12-19

information is accumulated (drift rate). Note that decision time is not equivalent to reaction time because reaction time includes non -decision time...countermeasures are not used. The magnitude of the performance loss is nearly equivalent to that measured using the psychomotor vigilance test, which is...model non -decision time parameter for Modafinil and No Modafinil groups as a function of measurement time for the 3D task

Caloric restriction and spatial learning in old mice.

PubMed

Bellush, L L; Wright, A M; Walker, J P; Kopchick, J; Colvin, R A

1996-08-01

Spatial learning in old mice (19 or 24 months old), some of which had been calorically restricted beginning at 14 weeks of age, was compared to that of young mice, in two separate experiments using a Morris water maze. In the first experiment, only old mice reaching criterion performance on a cued learning task were tested in a subsequent spatial task. Thus, all old mice tested for spatial learning had achieved escape latencies equivalent to those of young controls. Despite equivalent swimming speeds, only about half the old mice in each diet group achieved criterion performance in the spatial task. In the second experiment, old and young mice all received the same number of training trials in a cued task and then in a spatial task. Immediately following spatial training, they were given a 60-s probe trial, with no platform in the pool. Both groups of old mice spent significantly less time in the quadrant where the platform had been and made significantly fewer direct crosses over the previous platform location than did the young control group. As in Experiment 1, calorie restriction failed to provide protection against aging-related deficits. However, in both experiments, some individual old mice evidenced performance in spatial learning indistinguishable from that of young controls. Separate comparisons of "age-impaired" and "age-unimpaired" old mice with young controls may facilitate the identification of neurobiological mechanisms underlying age-related cognitive decline.

Evaluating the Effort Expended to Understand Speech in Noise Using a Dual-Task Paradigm: The Effects of Providing Visual Speech Cues

ERIC Educational Resources Information Center

Fraser, Sarah; Gagne, Jean-Pierre; Alepins, Majolaine; Dubois, Pascale

2010-01-01

Purpose: Using a dual-task paradigm, 2 experiments (Experiments 1 and 2) were conducted to assess differences in the amount of listening effort expended to understand speech in noise in audiovisual (AV) and audio-only (A-only) modalities. Experiment 1 had equivalent noise levels in both modalities, and Experiment 2 equated speech recognition…

Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEGF-mediated alternative activation of macrophage.

PubMed

Kim, Kyoung-Han; Kim, Yun Hye; Son, Joe Eun; Lee, Ju Hee; Kim, Sarah; Choe, Min Seon; Moon, Joon Ho; Zhong, Jian; Fu, Kiya; Lenglin, Florine; Yoo, Jeong-Ah; Bilan, Philip J; Klip, Amira; Nagy, Andras; Kim, Jae-Ryong; Park, Jin Gyoon; Hussein, Samer Mi; Doh, Kyung-Oh; Hui, Chi-Chung; Sung, Hoon-Ki

2017-11-01

Intermittent fasting (IF), a periodic energy restriction, has been shown to provide health benefits equivalent to prolonged fasting or caloric restriction. However, our understanding of the underlying mechanisms of IF-mediated metabolic benefits is limited. Here we show that isocaloric IF improves metabolic homeostasis against diet-induced obesity and metabolic dysfunction primarily through adipose thermogenesis in mice. IF-induced metabolic benefits require fasting-mediated increases of vascular endothelial growth factor (VEGF) expression in white adipose tissue (WAT). Furthermore, periodic adipose-VEGF overexpression could recapitulate the metabolic improvement of IF in non-fasted animals. Importantly, fasting and adipose-VEGF induce alternative activation of adipose macrophage, which is critical for thermogenesis. Human adipose gene analysis further revealed a positive correlation of adipose VEGF-M2 macrophage-WAT browning axis. The present study uncovers the molecular mechanism of IF-mediated metabolic benefit and suggests that isocaloric IF can be a preventive and therapeutic approach against obesity and metabolic disorders.

Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEGF-mediated alternative activation of macrophage

PubMed Central

Kim, Kyoung-Han; Kim, Yun Hye; Son, Joe Eun; Lee, Ju Hee; Kim, Sarah; Choe, Min Seon; Moon, Joon Ho; Zhong, Jian; Fu, Kiya; Lenglin, Florine; Yoo, Jeong-Ah; Bilan, Philip J; Klip, Amira; Nagy, Andras; Kim, Jae-Ryong; Park, Jin Gyoon; Hussein, Samer MI; Doh, Kyung-Oh; Hui, Chi-chung; Sung, Hoon-Ki

2017-01-01

Intermittent fasting (IF), a periodic energy restriction, has been shown to provide health benefits equivalent to prolonged fasting or caloric restriction. However, our understanding of the underlying mechanisms of IF-mediated metabolic benefits is limited. Here we show that isocaloric IF improves metabolic homeostasis against diet-induced obesity and metabolic dysfunction primarily through adipose thermogenesis in mice. IF-induced metabolic benefits require fasting-mediated increases of vascular endothelial growth factor (VEGF) expression in white adipose tissue (WAT). Furthermore, periodic adipose-VEGF overexpression could recapitulate the metabolic improvement of IF in non-fasted animals. Importantly, fasting and adipose-VEGF induce alternative activation of adipose macrophage, which is critical for thermogenesis. Human adipose gene analysis further revealed a positive correlation of adipose VEGF-M2 macrophage-WAT browning axis. The present study uncovers the molecular mechanism of IF-mediated metabolic benefit and suggests that isocaloric IF can be a preventive and therapeutic approach against obesity and metabolic disorders. PMID:29039412

[The effects of small amounts of alcohol on in-flight activity].

PubMed

Dionisi, A

1981-10-06

Alcohol metabolism is described prior to an account of its effect on vigilance. The psychological and psychosomatic influence of alcohol is also illustrated in the light of experimental data indicating how it alters the response to stimuli. Alterations in various parameters following the administration of significantly small doses of alcohol were studied. Reaction time decreased, then increased, followed by a further decrease after about 1 1/2 hr. Even 1/8th litre depresses receptiveness of the reticular substance, and leads to lengthening of reaction times due to diminished ability to concentrate attention on a given task. CNS depression is also in proportion to the complexity of the performance required. This is particularly and dangerous in pilots, whose tasks are extremely precise and require close attention. Functional alterations induced by alcohol during flight may be numerous, due to disturbances connected with the specific conditions created by flying, and apparatuses whose physiological functions are susceptible to disturbance by flying itself. Alcohol, itself a harmful influence on piloting an aircraft, deteriorates these functions and conditions. Toxic substances present during flying and their potentiation by alcohol are considered. The effects of alcohol, added to these specific pathogenetic toxic effects, quickly and readily lead to a fall in overall psychophysical efficiency, and prejudice flight safety. the reason why a decrease in the limit intake doses to less than 2 cc/kg, equivalent to a blood value of 0.5 g 0/00, to ensure safe control of the plane, is desirable is explained.

Consecutive learning of opposing unimanual motor tasks using the right arm followed by the left arm causes intermanual interference

PubMed Central

Thürer, Benjamin; Stein, Thorsten

2017-01-01

Intermanual transfer (motor memory generalization across arms) and motor memory interference (impairment of retest performance in consecutive motor learning) are well-investigated motor learning phenomena. However, the interplay of these phenomena remains elusive, i.e., whether intermanual interference occurs when two unimanual tasks are consecutively learned using different arms. Here, we examine intermanual interference when subjects consecutively adapt their right and left arm movements to novel dynamics. We considered two force field tasks A and B which were of the same structure but mirrored orientation (B = -A). The first test group (ABA-group) consecutively learned task A using their right arm and task B using their left arm before being retested for task A with their right arm. Another test group (AAA-group) learned only task A in the same right-left-right arm schedule. Control subjects learned task A using their right arm without intermediate left arm learning. All groups were able to adapt their right arm movements to force field A and both test groups showed significant intermanual transfer of this initial learning to the contralateral left arm of 21.9% (ABA-group) and 27.6% (AAA-group). Consecutively, both test groups adapted their left arm movements to force field B (ABA-group) or force field A (AAA-group). For the ABA-group, left arm learning caused significant intermanual interference of the initially learned right arm task (68.3% performance decrease). The performance decrease of the AAA-group (10.2%) did not differ from controls (15.5%). These findings suggest that motor control and learning of right and left arm movements involve partly similar neural networks or underlie a vital interhemispheric connectivity. Moreover, our results suggest a preferred internal task representation in extrinsic Cartesian-based coordinates rather than in intrinsic joint-based coordinates because interference was absent when learning was performed in extrinsically equivalent fashion (AAA-group) but interference occurred when learning was performed in intrinsically equivalent fashion (ABA-group). PMID:28459833

Consecutive learning of opposing unimanual motor tasks using the right arm followed by the left arm causes intermanual interference.

PubMed

Stockinger, Christian; Thürer, Benjamin; Stein, Thorsten

2017-01-01

Intermanual transfer (motor memory generalization across arms) and motor memory interference (impairment of retest performance in consecutive motor learning) are well-investigated motor learning phenomena. However, the interplay of these phenomena remains elusive, i.e., whether intermanual interference occurs when two unimanual tasks are consecutively learned using different arms. Here, we examine intermanual interference when subjects consecutively adapt their right and left arm movements to novel dynamics. We considered two force field tasks A and B which were of the same structure but mirrored orientation (B = -A). The first test group (ABA-group) consecutively learned task A using their right arm and task B using their left arm before being retested for task A with their right arm. Another test group (AAA-group) learned only task A in the same right-left-right arm schedule. Control subjects learned task A using their right arm without intermediate left arm learning. All groups were able to adapt their right arm movements to force field A and both test groups showed significant intermanual transfer of this initial learning to the contralateral left arm of 21.9% (ABA-group) and 27.6% (AAA-group). Consecutively, both test groups adapted their left arm movements to force field B (ABA-group) or force field A (AAA-group). For the ABA-group, left arm learning caused significant intermanual interference of the initially learned right arm task (68.3% performance decrease). The performance decrease of the AAA-group (10.2%) did not differ from controls (15.5%). These findings suggest that motor control and learning of right and left arm movements involve partly similar neural networks or underlie a vital interhemispheric connectivity. Moreover, our results suggest a preferred internal task representation in extrinsic Cartesian-based coordinates rather than in intrinsic joint-based coordinates because interference was absent when learning was performed in extrinsically equivalent fashion (AAA-group) but interference occurred when learning was performed in intrinsically equivalent fashion (ABA-group).

Rhythm and Melody Tasks for School-Aged Children With and Without Musical Training: Age-Equivalent Scores and Reliability.

PubMed

Ireland, Kierla; Parker, Averil; Foster, Nicholas; Penhune, Virginia

2018-01-01

Measuring musical abilities in childhood can be challenging. When music training and maturation occur simultaneously, it is difficult to separate the effects of specific experience from age-based changes in cognitive and motor abilities. The goal of this study was to develop age-equivalent scores for two measures of musical ability that could be reliably used with school-aged children (7-13) with and without musical training. The children's Rhythm Synchronization Task (c-RST) and the children's Melody Discrimination Task (c-MDT) were adapted from adult tasks developed and used in our laboratories. The c-RST is a motor task in which children listen and then try to synchronize their taps with the notes of a woodblock rhythm while it plays twice in a row. The c-MDT is a perceptual task in which the child listens to two melodies and decides if the second was the same or different. We administered these tasks to 213 children in music camps (musicians, n = 130) and science camps (non-musicians, n = 83). We also measured children's paced tapping, non-paced tapping, and phonemic discrimination as baseline motor and auditory abilities We estimated internal-consistency reliability for both tasks, and compared children's performance to results from studies with adults. As expected, musically trained children outperformed those without music lessons, scores decreased as difficulty increased, and older children performed the best. Using non-musicians as a reference group, we generated a set of age-based z-scores, and used them to predict task performance with additional years of training. Years of lessons significantly predicted performance on both tasks, over and above the effect of age. We also assessed the relation between musician's scores on music tasks, baseline tasks, auditory working memory, and non-verbal reasoning. Unexpectedly, musician children outperformed non-musicians in two of three baseline tasks. The c-RST and c-MDT fill an important need for researchers interested in evaluating the impact of musical training in longitudinal studies, those interested in comparing the efficacy of different training methods, and for those assessing the impact of training on non-musical cognitive abilities such as language processing.

Rhythm and Melody Tasks for School-Aged Children With and Without Musical Training: Age-Equivalent Scores and Reliability

PubMed Central

Ireland, Kierla; Parker, Averil; Foster, Nicholas; Penhune, Virginia

2018-01-01

Measuring musical abilities in childhood can be challenging. When music training and maturation occur simultaneously, it is difficult to separate the effects of specific experience from age-based changes in cognitive and motor abilities. The goal of this study was to develop age-equivalent scores for two measures of musical ability that could be reliably used with school-aged children (7–13) with and without musical training. The children's Rhythm Synchronization Task (c-RST) and the children's Melody Discrimination Task (c-MDT) were adapted from adult tasks developed and used in our laboratories. The c-RST is a motor task in which children listen and then try to synchronize their taps with the notes of a woodblock rhythm while it plays twice in a row. The c-MDT is a perceptual task in which the child listens to two melodies and decides if the second was the same or different. We administered these tasks to 213 children in music camps (musicians, n = 130) and science camps (non-musicians, n = 83). We also measured children's paced tapping, non-paced tapping, and phonemic discrimination as baseline motor and auditory abilities We estimated internal-consistency reliability for both tasks, and compared children's performance to results from studies with adults. As expected, musically trained children outperformed those without music lessons, scores decreased as difficulty increased, and older children performed the best. Using non-musicians as a reference group, we generated a set of age-based z-scores, and used them to predict task performance with additional years of training. Years of lessons significantly predicted performance on both tasks, over and above the effect of age. We also assessed the relation between musician's scores on music tasks, baseline tasks, auditory working memory, and non-verbal reasoning. Unexpectedly, musician children outperformed non-musicians in two of three baseline tasks. The c-RST and c-MDT fill an important need for researchers interested in evaluating the impact of musical training in longitudinal studies, those interested in comparing the efficacy of different training methods, and for those assessing the impact of training on non-musical cognitive abilities such as language processing. PMID:29674984

Metabolic profile of the bioactive compounds of burdock (Arctium lappa) seeds, roots and leaves.

PubMed

Ferracane, Rosalia; Graziani, Giulia; Gallo, Monica; Fogliano, Vincenzo; Ritieni, Alberto

2010-01-20

In this work the bioactive metabolic profile, the antioxidant activity and total phenolic content of burdock (Arctium lappa) seeds, leaves and roots were obtained. TEAC values and total phenolic content for hydro-alcoholic extracts of burdock ranged from 67.39 to 1.63 micromol Trolox equivalent/100g dry weight (DW), and from 2.87 to 45 g of gallic acid equivalent/100g DW, respectively. Phytochemical compounds were analyzed by liquid chromatography coupled to electrospray tandem mass spectrometry (LC/MS/MS) in negative mode. The main compounds of burdock extracts were caffeoylquinic acid derivatives, lignans (mainly arctiin) and various flavonoids. The occurrence of some phenolic acids (caffeic acid, chlorogenic acid and cynarin) in burdock seeds; arctiin, luteolin and quercetin rhamnoside in burdock roots; phenolic acids, quercetin, quercitrin and luteolin in burdock leaves was reported for the first time.

Right Limbic FDG-PET Hypometabolism Correlates with Emotion Recognition and Attribution in Probable Behavioral Variant of Frontotemporal Dementia Patients

PubMed Central

Cerami, Chiara; Dodich, Alessandra; Iannaccone, Sandro; Marcone, Alessandra; Lettieri, Giada; Crespi, Chiara; Gianolli, Luigi; Cappa, Stefano F.; Perani, Daniela

2015-01-01

The behavioural variant of frontotemporal dementia (bvFTD) is a rare disease mainly affecting the social brain. FDG-PET fronto-temporal hypometabolism is a supportive feature for the diagnosis. It may also provide specific functional metabolic signatures for altered socio-emotional processing. In this study, we evaluated the emotion recognition and attribution deficits and FDG-PET cerebral metabolic patterns at the group and individual levels in a sample of sporadic bvFTD patients, exploring the cognitive-functional correlations. Seventeen probable mild bvFTD patients (10 male and 7 female; age 67.8±9.9) were administered standardized and validated version of social cognition tasks assessing the recognition of basic emotions and the attribution of emotions and intentions (i.e., Ekman 60-Faces test-Ek60F and Story-based Empathy task-SET). FDG-PET was analysed using an optimized voxel-based SPM method at the single-subject and group levels. Severe deficits of emotion recognition and processing characterized the bvFTD condition. At the group level, metabolic dysfunction in the right amygdala, temporal pole, and middle cingulate cortex was highly correlated to the emotional recognition and attribution performances. At the single-subject level, however, heterogeneous impairments of social cognition tasks emerged, and different metabolic patterns, involving limbic structures and prefrontal cortices, were also observed. The derangement of a right limbic network is associated with altered socio-emotional processing in bvFTD patients, but different hypometabolic FDG-PET patterns and heterogeneous performances on social tasks at an individual level exist. PMID:26513651

Intelligence and Changes in Regional Cerebral Glucose Metabolic Rate Following Learning.

ERIC Educational Resources Information Center

Haier, Richard J.; And Others

1992-01-01

A study of eight normal right-handed men demonstrates widespread significant decreases in brain glucose metabolic rate (GMR) following learning a complex computer task, a computer game. Correlations between magnitude of GMR change and intelligence scores are also demonstrated. (SLD)

Learning and generalization from reward and punishment in opioid addiction.

PubMed

Myers, Catherine E; Rego, Janice; Haber, Paul; Morley, Kirsten; Beck, Kevin D; Hogarth, Lee; Moustafa, Ahmed A

2017-01-15

This study adapts a widely-used acquired equivalence paradigm to investigate how opioid-addicted individuals learn from positive and negative feedback, and how they generalize this learning. The opioid-addicted group consisted of 33 participants with a history of heroin dependency currently in a methadone maintenance program; the control group consisted of 32 healthy participants without a history of drug addiction. All participants performed a novel variant of the acquired equivalence task, where they learned to map some stimuli to correct outcomes in order to obtain reward, and to map other stimuli to correct outcomes in order to avoid punishment; some stimuli were implicitly "equivalent" in the sense of being paired with the same outcome. On the initial training phase, both groups performed similarly on learning to obtain reward, but as memory load grew, the control group outperformed the addicted group on learning to avoid punishment. On a subsequent testing phase, the addicted and control groups performed similarly on retention trials involving previously-trained stimulus-outcome pairs, as well as on generalization trials to assess acquired equivalence. Since prior work with acquired equivalence tasks has associated stimulus-outcome learning with the nigrostriatal dopamine system, and generalization with the hippocampal region, the current results are consistent with basal ganglia dysfunction in the opioid-addicted patients. Further, a selective deficit in learning from punishment could contribute to processes by which addicted individuals continue to pursue drug use even at the cost of negative consequences such as loss of income and the opportunity to engage in other life activities. Published by Elsevier B.V.

Consistency of performance of robot-assisted surgical tasks in virtual reality.

PubMed

Suh, I H; Siu, K-C; Mukherjee, M; Monk, E; Oleynikov, D; Stergiou, N

2009-01-01

The purpose of this study was to investigate consistency of performance of robot-assisted surgical tasks in a virtual reality environment. Eight subjects performed two surgical tasks, bimanual carrying and needle passing, with both the da Vinci surgical robot and a virtual reality equivalent environment. Nonlinear analysis was utilized to evaluate consistency of performance by calculating the regularity and the amount of divergence in the movement trajectories of the surgical instrument tips. Our results revealed that movement patterns for both training tasks were statistically similar between the two environments. Consistency of performance as measured by nonlinear analysis could be an appropriate methodology to evaluate the complexity of the training tasks between actual and virtual environments and assist in developing better surgical training programs.

Influence of cellular and paracellular conductance patterns on epithelial transport and metabolism.

PubMed Central

Essig, A

1982-01-01

Theoretical analysis of transepithelial active Na transport is often based on equivalent electrical circuits comprising discrete parallel active and passive pathways. Recent findings show, however, that Na+ pumps are distributed over the entire basal lateral surface of epithelial cells. This suggests that Na+ that has been actively transported into paracellular channels may to some extent return to the apical (mucosal) bathing solution, depending on the relative conductances of the pathways via the tight junctions and the lateral intercellular spaces. Such circulation, as well as the relative conductance of cellular and paracellular pathways, may have an important influence on the relationships between parameters of transcellular and transepithelial active transport and metabolism. These relationships were examined by equivalent circuit analysis of active Na transport, Na conductance, the electromotive force of Na transport, the "stoichiometry" of transport, and the degree of coupling of transport to metabolism. Although the model is too crude to permit precise quantification, important qualitative differences are predicted between "loose" and "tight" epithelia in the absence and presence of circulation. In contrast, there is no effect on the free energy of metabolic reaction estimated from a linear thermodynamic formalism. Also of interest are implications concerning the experimental evaluation of passive paracellular conductance following abolition of active transport, and the use of the cellular voltage-divider ratio to estimate the relative conductances of apical and basal lateral plasma membranes. PMID:6284264

In vitro 3D full thickness skin equivalent tissue model using silk and collagen biomaterials

PubMed Central

Bellas, Evangelia; Seiberg, Miri; Garlick, Jonathan; Kaplan, David L.

2013-01-01

Current approaches to develop skin equivalents often only include the epidermal and dermal components. Yet, full thickness skin includes the hypodermis, a layer below the dermis of adipose tissue containing vasculature, nerves and fibroblasts, necessary to support the epidermis and dermis. In the present study, we developed a full thickness skin equivalent including an epidermis, dermis and hypodermis that could serve as an in vitro model for studying skin development, disease or as a platform for consumer product testing as a means to avoid animal testing. The full thickness skin equivalent was easy to handle and was maintained in culture for greater than 14 days while expressing physiologically relevant morphologies of both the epidermis and dermis, as seen by keratin 10, collagen I and collagen IV expression. The skin equivalent produced glycerol and leptin, markers of adipose tissue metabolism. This work serves as a foundation for our understanding of some of the necessary factors needed to develop a stable, functional model of full-thickness skin. PMID:23161763

Carotenoid metabolic profiling and transcriptome-genome mining reveal functional equivalence among blue-pigmented copepods and appendicularia.

PubMed

Mojib, Nazia; Amad, Maan; Thimma, Manjula; Aldanondo, Naroa; Kumaran, Mande; Irigoien, Xabier

2014-06-01

The tropical oligotrophic oceanic areas are characterized by high water transparency and annual solar radiation. Under these conditions, a large number of phylogenetically diverse mesozooplankton species living in the surface waters (neuston) are found to be blue pigmented. In the present study, we focused on understanding the metabolic and genetic basis of the observed blue phenotype functional equivalence between the blue-pigmented organisms from the phylum Arthropoda, subclass Copepoda (Acartia fossae) and the phylum Chordata, class Appendicularia (Oikopleura dioica) in the Red Sea. Previous studies have shown that carotenoid-protein complexes are responsible for blue coloration in crustaceans. Therefore, we performed carotenoid metabolic profiling using both targeted and nontargeted (high-resolution mass spectrometry) approaches in four different blue-pigmented genera of copepods and one blue-pigmented species of appendicularia. Astaxanthin was found to be the principal carotenoid in all the species. The pathway analysis showed that all the species can synthesize astaxanthin from β-carotene, ingested from dietary sources, via 3-hydroxyechinenone, canthaxanthin, zeaxanthin, adonirubin or adonixanthin. Further, using de novo assembled transcriptome of blue A. fossae (subclass Copepoda), we identified highly expressed homologous β-carotene hydroxylase enzymes and putative carotenoid-binding proteins responsible for astaxanthin formation and the blue phenotype. In blue O. dioica (class Appendicularia), corresponding putative genes were identified from the reference genome. Collectively, our data provide molecular evidences for the bioconversion and accumulation of blue astaxanthin-protein complexes underpinning the observed ecological functional equivalence and adaptive convergence among neustonic mesozooplankton. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Metabolic breath analyzer

NASA Technical Reports Server (NTRS)

Perry, C. L.

1971-01-01

Instrument measures metabolic breathing rate and dynamics of human beings in atmospheres ranging from normal air to 100 percent oxygen at ambient pressures from 14.7 to 3.0 psia. Measurements are made at rest or performing tasks up to maximum physical capacity under either zero or normal gravity.

Simultaneous transcranial direct current stimulation (tDCS) and whole-head magnetoencephalography (MEG): assessing the impact of tDCS on slow cortical magnetic fields.

PubMed

Garcia-Cossio, Eliana; Witkowski, Matthias; Robinson, Stephen E; Cohen, Leonardo G; Birbaumer, Niels; Soekadar, Surjo R

2016-10-15

Transcranial direct current stimulation (tDCS) can influence cognitive, affective or motor brain functions. Whereas previous imaging studies demonstrated widespread tDCS effects on brain metabolism, direct impact of tDCS on electric or magnetic source activity in task-related brain areas could not be confirmed due to the difficulty to record such activity simultaneously during tDCS. The aim of this proof-of-principal study was to demonstrate the feasibility of whole-head source localization and reconstruction of neuromagnetic brain activity during tDCS and to confirm the direct effect of tDCS on ongoing neuromagnetic activity in task-related brain areas. Here we show for the first time that tDCS has an immediate impact on slow cortical magnetic fields (SCF, 0-4Hz) of task-related areas that are identical with brain regions previously described in metabolic neuroimaging studies. 14 healthy volunteers performed a choice reaction time (RT) task while whole-head magnetoencephalography (MEG) was recorded. Task-related source-activity of SCFs was calculated using synthetic aperture magnetometry (SAM) in absence of stimulation and while anodal, cathodal or sham tDCS was delivered over the right primary motor cortex (M1). Source reconstruction revealed task-related SCF modulations in brain regions that precisely matched prior metabolic neuroimaging studies. Anodal and cathodal tDCS had a polarity-dependent impact on RT and SCF in primary sensorimotor and medial centro-parietal cortices. Combining tDCS and whole-head MEG is a powerful approach to investigate the direct effects of transcranial electric currents on ongoing neuromagnetic source activity, brain function and behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

Simultaneous transcranial direct current stimulation (tDCS) and whole-head magnetoencephalography (MEG): assessing the impact of tDCS on slow cortical magnetic fields

PubMed Central

Garcia-Cossio, Eliana; Witkowski, Matthias; Robinson, Stephen E.; Cohen, Leonardo G.; Birbaumer, Niels; Soekadar, Surjo R.

2016-01-01

Transcranial direct current stimulation (tDCS) can influence cognitive, affective or motor brain functions. Whereas previous imaging studies demonstrated widespread tDCS effects on brain metabolism, direct impact of tDCS on electric or magnetic source activity in task-related brain areas could not be confirmed due to the difficulty to record such activity simultaneously during tDCS. The aim of this proof-of-principal study was to demonstrate the feasibility of whole-head source localization and reconstruction of neuromagnetic brain activity during tDCS and to confirm the direct effect of tDCS on ongoing neuromagnetic activity in task-related brain areas. Here we show for the first time that tDCS has an immediate impact on slow cortical magnetic fields (SCF, 0–4 Hz) of task-related areas that are identical with brain regions previously described in metabolic neuroimaging studies. 14 healthy volunteers performed a choice reaction time (RT) task while whole-head magnetoencephalography (MEG) was recorded. Task-related source-activity of SCFs was calculated using synthetic aperture magnetometry (SAM) in absence of stimulation and while anodal, cathodal or sham tDCS was delivered over the right primary motor cortex (M1). Source reconstruction revealed task-related SCF modulations in brain regions that precisely matched prior metabolic neuroimaging studies. Anodal and cathodal tDCS had a polarity-dependent impact on RT and SCF in primary sensorimotor and medial centro-parietal cortices. Combining tDCS and whole-head MEG is a powerful approach to investigate the direct effects of transcranial electric currents on ongoing neuromagnetic source activity, brain function and behavior. PMID:26455796

Multi-modal information processing for visual workload relief

NASA Technical Reports Server (NTRS)

Burke, M. W.; Gilson, R. D.; Jagacinski, R. J.

1980-01-01

The simultaneous performance of two single-dimensional compensatory tracking tasks, one with the left hand and one with the right hand, is discussed. The tracking performed with the left hand was considered the primary task and was performed with a visual display or a quickened kinesthetic-tactual (KT) display. The right-handed tracking was considered the secondary task and was carried out only with a visual display. Although the two primary task displays had afforded equivalent performance in a critical tracking task performed alone, in the dual-task situation the quickened KT primary display resulted in superior secondary visual task performance. Comparisons of various combinations of primary and secondary visual displays in integrated or separated formats indicate that the superiority of the quickened KT display is not simply due to the elimination of visual scanning. Additional testing indicated that quickening per se also is not the immediate cause of the observed KT superiority.

The effect of methylphenidate on postural stability under single and dual task conditions in children with attention deficit hyperactivity disorder - a double blind randomized control trial.

PubMed

Jacobi-Polishook, Talia; Shorer, Zamir; Melzer, Itshak

2009-05-15

To investigate the effects of Methylphenidate (MPH) on postural stability in attention deficit hyperactivity disorder (ADHD) children in single and dual task conditions. A randomized controlled double-blind study analyzing postural stability in 24 ADHD children before and after MPH vs. placebo treatments, in three task conditions: (1) Single task, standing still; (2) dual task, standing still performing a memory-attention demanding task; (3) standing still listening to music. MPH resulted in a significant improvement in postural stability during the dual task condition and while listening to music, with no equivalent improvement in placebo controls. MPH improves postural stability in ADHD, especially when an additional task is performed. This is probably due to enhanced attention abilities, thus contributing to improved balance control during performance of tasks that require attention. MPH remains to be studied as a potential drug treatment to improve balance control and physical functioning in other clinical populations.

Interference Control In Elderly Bilinguals: Appearances Can Be Misleading.

PubMed

Ansaldo, Ana Inés; Ghazi-Saidi, Ladan; Adrover-Roig, Daniel

2015-01-01

Bilingualism has been associated with successful aging. In particular, research on the cognitive advantages of bilingualism suggests that it can enhance control over interference and help delay the onset of dementia signs. However, the evidence on the so-called cognitive advantage is not unanimous; furthermore, little is known about the neural basis of this supposed cognitive advantage in bilingual as opposed to monolingual elderly populations. In this study, elderly bilingual and monolingual participants performed a visuospatial interference control task during functional magnetic resonance imaging (fMRI) scanning. Response times and accuracy rates were calculated for congruent and incongruent conditions of the Simon task, and the neurofunctional correlates of performance on the Simon task were examined. The results showed equivalent performance on the Simon task across groups but different underlying neural substrates in the two groups. With incongruent trials, monolinguals activated the right middle frontal gyrus, whereas bilinguals relied upon the left inferior parietal lobule. These results show that elderly bilinguals and monolinguals have equivalent interference control abilities, but relay on different neural substrates. Thus, while monolinguals show a classical PASA (posterior-anterior shift in aging) effect, recruiting frontal areas, bilinguals activate visuospatial processing alone and thus do not show this posterior-anterior shift. Moreover, a modulation of frontal activity with task-dynamic control of interference, observed in the elderly bilingual group alone, suggests that elderly bilinguals deal with interference control without recruiting a circuit that is particularly vulnerable to aging.

Towards the unification of inference structures in medical diagnostic tasks.

PubMed

Mira, J; Rives, J; Delgado, A E; Martínez, R

1998-01-01

The central purpose of artificial intelligence applied to medicine is to develop models for diagnosis and therapy planning at the knowledge level, in the Newell sense, and software environments to facilitate the reduction of these models to the symbol level. The usual methodology (KADS, Common-KADS, GAMES, HELIOS, Protégé, etc) has been to develop libraries of generic tasks and reusable problem-solving methods with explicit ontologies. The principal problem which clinicians have with these methodological developments concerns the diversity and complexity of new terms whose meaning is not sufficiently clear, precise, unambiguous and consensual for them to be accessible in the daily clinical environment. As a contribution to the solution of this problem, we develop in this article the conjecture that one inference structure is enough to describe the set of analysis tasks associated with medical diagnoses. To this end, we first propose a modification of the systematic diagnostic inference scheme to obtain an analysis generic task and then compare it with the monitoring and the heuristic classification task inference schemes using as comparison criteria the compatibility of domain roles (data structures), the similarity in the inferences, and the commonality in the set of assumptions which underlie the functionally equivalent models. The equivalences proposed are illustrated with several examples. Note that though our ongoing work aims to simplify the methodology and to increase the precision of the terms used, the proposal presented here should be viewed more in the nature of a conjecture.

An Assessment of the Training Effectiveness of Device 2F64C for Training Helicopter Replacement Pilots.

DTIC Science & Technology

1982-07-01

was scheduled for an end-of-phase assessment ( equivalent to the stage check for the control group on the sixth flight). If performance was to NATOPS...proficiency was demonstrated. The same procedure was used for B stage flight except that the phase check (fourth flight) was equivalent to the control ...experimental grouo did not differ from the control qroup on tasks requirinq visual cues as a primary reference for successful completion (e.g

Landing flying qualities evaluation criteria for augmented aircraft

NASA Technical Reports Server (NTRS)

Radford, R. C.; Smith, R.; Bailey, R.

1980-01-01

The criteria evaluated were: Calspan Neal-Smith; Onstott (Northrop Time Domain); McDonnell-Douglas Equivalent System Approach; R. H. Smith Criterion. Each criterion was applied to the same set of longitudinal approach and landing flying qualities data. A revised version of the Neal-Smith criterion which is applicable to the landing task was developed and tested against other landing flying qualities data. Results indicated that both the revised Neal-Smith criterion and the Equivalent System Approach are good discriminators of pitch landing flying qualities; Neal-Smith has particular merit as a design guide, while the Equivalent System Approach is well suited for development of appropriate military specification requirements applicable to highly augmented aircraft.

Targeting Metabolic Survival Pathways in Lung Cancer via Combination Therapy

DTIC Science & Technology

2014-06-01

B1, non-small cell lung cancer, glutamine metabolism, biguanides 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18 . NUMBER OF...combination therapy (months 15-16) Task 5. In vivo testing of biguanide and glutamine metabolism inhibitors in xenograft models of LKB1-proficient and...combination therapies in xenograft mice (months 12-15) IACUC and ACURO approval have been granted for in vivo xenograft studies, which will commence in

Emergent Leadership and Team Effectiveness on a Team Resource Allocation Task

DTIC Science & Technology

1987-10-01

equivalent training and experience on this task, but they had different levels of experience with computers and video games . This differential experience...typed: that is. it is sex-typed to the extent that males spend mnore time on related instrumeuts like computers and video games . However. the sex...perform better or worse than less talkative teams? Did teams with much computer and ’or video game experience perform better than inexperienced teams

Variability in hand-arm vibration during grinding operations.

PubMed

Liljelind, Ingrid; Wahlström, Jens; Nilsson, Leif; Toomingas, Allan; Burström, Lage

2011-04-01

Measurements of exposure to vibrations from hand-held tools are often conducted on a single occasion. However, repeated measurements may be crucial for estimating the actual dose with good precision. In addition, knowledge of determinants of exposure could be used to improve working conditions. The aim of this study was to assess hand-arm vibration (HAV) exposure during different grinding operations, in order to obtain estimates of the variance components and to evaluate the effect of work postures. Ten experienced operators used two compressed air-driven angle grinders of the same make in a simulated work task at a workplace. One part of the study consisted of using a grinder while assuming two different working postures: at a standard work bench (low) and on a wall with arms elevated and the work area adjusted to each operator's height (high). The workers repeated the task three times. In another part of the study, investigating the wheel wear, for each grinder, the operators used two new grinding wheels and with each wheel the operator performed two consecutive 1-min grinding tasks. Both grinding tasks were conducted on weld puddles of mild steel on a piece of mild steel. Measurements were taken according to ISO-standard 5349 [the equivalent hand-arm-weighted acceleration (m s(-2)) averaged over 1 min]. Mixed- and random-effects models were used to investigate the influence of the fixed variables and to estimate variance components. The equivalent hand-arm-weighted acceleration assessed when the task was performed on the bench and at the wall was 3.2 and 3.3 m s(-2), respectively. In the mixed-effects model, work posture was not a significant variable. The variables 'operator' and 'grinder' together explained only 12% of the exposure variability and 'grinding wheel' explained 47%; the residual variability of 41% remained unexplained. When the effect of grinding wheel wear was investigated in the random-effects model, 37% of the variability was associated with the wheel while minimal variability was associated with the operator or the grinder and 37% was unexplained. The interaction effect of grinder and operator explained 18% of the variability. In the wheel wear test, the equivalent hand-arm-weighted accelerations for Grinder 1 during the first and second grinding minutes were 3.4 and 2.9 m s(-2), respectively, and for Grinder 2, they were 3.1 and 2.9 m s(-2), respectively. For Grinder 1, the equivalent hand-arm-weighted acceleration during the first grinding minute was significantly higher (P = 0.04) than during the second minute. Work posture during grinding operations does not appear to affect the level of HAV. Grinding wheels explained much of the variability in this study, but almost 40% of the variance remained unexplained. The considerable variability in the equivalent hand-arm-weighted acceleration has an impact on the risk assessment at both the group and the individual level.

Are gamers better crossers? An examination of action video game experience and dual task effects in a simulated street crossing task.

PubMed

Gaspar, John G; Neider, Mark B; Crowell, James A; Lutz, Aubrey; Kaczmarski, Henry; Kramer, Arthur F

2014-05-01

A high-fidelity street crossing simulator was used to test the hypothesis that experienced action video game players are less vulnerable than non-gamers to dual task costs in complex tasks. Previous research has shown that action video game players outperform nonplayers on many single task measures of perception and attention. It is unclear, however, whether action video game players outperform nonplayers in complex, divided attention tasks. Experienced action video game players and nongamers completed a street crossing task in a high-fidelity simulator. Participants walked on a manual treadmill to cross the street. During some crossings, a cognitively demanding working memory task was added. Dividing attention resulted in more collisions and increased decision making time. Of importance, these dual task costs were equivalent for the action video game players and the nongamers. These results suggest that action video game players are equally susceptible to the costs of dividing attention in a complex task. Perceptual and attentional benefits associated with action video game experience may not translate to performance benefits in complex, real-world tasks.

Physiological roles of nicotinamide nucleotide transhydrogenase.

PubMed

Hoek, J B; Rydström, J

1988-08-15

From the foregoing considerations, the energy-linked transhydrogenase reaction emerges as a powerful and flexible element in the network of redox and energy interrelationships that integrate mitochondrial and cytosolic metabolism. Its thermodynamic features make it possible for the reaction to respond readily to challenges, either on the side of NADPH utilization or on the side of energy depletion. Yet, the kinetic features are designed to prevent a wasteful input of energy when other sources of reducing equivalents to NADP are available, or to deplete the redox potential of NADPH in other than emergency conditions. By virtue of these characteristics, the energy-linked transhydrogenase can act as an effective buffer system, guarding against an excessive depletion of NADPH, preventing uncontrolled changes in key metabolites associated with NADP-dependent enzymes and calling on the supply of reducing equivalents from NAD-linked substrates only under conditions of high demand for NADPH. At the same time, it can provide an emergency protection against a depletion of energy, especially in situations of anoxia where a supply of reducing equivalents through NADP-linked substrates can be maintained. The flexibility of this design makes it possible that the functions of the energy-linked transhydrogenase vary from one tissue to another and are readily adjustable to different metabolic conditions.

Capturing the essence of a metabolic network: a flux balance analysis approach.

PubMed

Murabito, Ettore; Simeonidis, Evangelos; Smallbone, Kieran; Swinton, Jonathan

2009-10-07

As genome-scale metabolic reconstructions emerge, tools to manage their size and complexity will be increasingly important. Flux balance analysis (FBA) is a constraint-based approach widely used to study the metabolic capabilities of cellular or subcellular systems. FBA problems are highly underdetermined and many different phenotypes can satisfy any set of constraints through which the metabolic system is represented. Two of the main concerns in FBA are exploring the space of solutions for a given metabolic network and finding a specific phenotype which is representative for a given task such as maximal growth rate. Here, we introduce a recursive algorithm suitable for overcoming both of these concerns. The method proposed is able to find the alternate optimal patterns of active reactions of an FBA problem and identify the minimal subnetwork able to perform a specific task as optimally as the whole. Our method represents an alternative to and an extension of other approaches conceived for exploring the space of solutions of an FBA problem. It may also be particularly helpful in defining a scaffold of reactions upon which to build up a dynamic model, when the important pathways of the system have not yet been well-defined.

Holistic Processing in the Composite Task Depends on Face Size

PubMed Central

Ross, David A.; Gauthier, Isabel

2015-01-01

Holistic processing is a hallmark of face processing. There is evidence that holistic processing is strongest for faces at identification distance, 2 – 10 meters from the observer. However, this evidence is based on tasks that have been little used in the literature and that are indirect measures of holistic processing. We use the composite task– a well validated and frequently used paradigm – to measure the effect of viewing distance on holistic processing. In line with previous work, we find a congruency x alignment effect that is strongest for faces that are close (2m equivalent distance) than for faces that are further away (24m equivalent distance). In contrast, the alignment effect for same trials, used by several authors to measure holistic processing, produced results that are difficult to interpret. We conclude that our results converge with previous findings providing more direct evidence for an effect of size on holistic processing. PMID:26500423

Development of a standardized job description for healthcare managers of metabolic syndrome management programs in Korean community health centers.

PubMed

Lee, Youngjin; Choo, Jina; Cho, Jeonghyun; Kim, So-Nam; Lee, Hye-Eun; Yoon, Seok-Jun; Seomun, GyeongAe

2014-03-01

This study aimed to develop a job description for healthcare managers of metabolic syndrome management programs using task analysis. Exploratory research was performed by using the Developing a Curriculum method, the Intervention Wheel model, and focus group discussions. Subsequently, we conducted a survey of 215 healthcare workers from 25 community health centers to verify that the job description we created was accurate. We defined the role of healthcare managers. Next, we elucidated the tasks of healthcare managers and performed needs analysis to examine the frequency, importance, and difficulty of each of their duties. Finally, we verified that our job description was accurate. Based on the 8 duties, 30 tasks, and 44 task elements assigned to healthcare managers, we found that the healthcare managers functioned both as team coordinators responsible for providing multidisciplinary health services and nurse specialists providing health promotion services. In terms of importance and difficulty of tasks performed by the healthcare managers, which were measured using a determinant coefficient, the highest-ranked task was planning social marketing (15.4), while the lowest-ranked task was managing human resources (9.9). A job description for healthcare managers may provide basic data essential for the development of a job training program for healthcare managers working in community health promotion programs. Copyright © 2014. Published by Elsevier B.V.

Nonspecificity and theory of mind: new evidence from a nonverbal false-sign task and children with autism spectrum disorders.

PubMed

Iao, Lai-Sang; Leekam, Susan R

2014-06-01

Understanding of false belief has long been considered to be a crucial aspect of "theory of mind" that can be explained by a domain-specific mechanism. We argue against this claim using new evidence from a nonverbal false representation task (false-sign task) with typically developing children and children with autism spectrum disorders (ASD). Experiments 1 and 2 showed that typically developing children (mean age=62.67months) were equivalent in their performance across nonverbal and verbal forms of both the false-belief and false-sign tasks. Results for these two misrepresentation tasks differed from the results of an outdated representation task ("false"-photograph task). Experiment 3 showed that children with ASD had difficulties with the false representation tasks, and this could not be explained by executive functioning or language impairments. These findings support the view that children with ASD might not have a specific theory-of-mind deficit. Copyright © 2013 Elsevier Inc. All rights reserved.

Measurement of functional capacity requirements of police officers to aid in development of an occupation-specific cardiac rehabilitation training program.

PubMed

Adams, Jenny; Schneider, Jonna; Hubbard, Matthew; McCullough-Shock, Tiffany; Cheng, Dunlei; Simms, Kay; Hartman, Julie; Hinton, Paul; Strauss, Danielle

2010-01-01

This study was designed to measure the functional capacity of healthy subjects during strenuous simulated police tasks, with the goal of developing occupation-specific training for cardiac rehabilitation of police officers. A calibrated metabolic instrument and an oxygen consumption data collection mask were used to measure the oxygen consumption and heart rates of 30 Dallas Police Academy officers and cadets as they completed an 8-event obstacle course that simulated chasing, subduing, and handcuffing a suspect. Standard target heart rates (85% of age-predicted maximum heart rate, or 0.85 x [220 - age]) and metabolic equivalents (METs) were calculated; a matched-sample t test based on differences between target and achieved heart rate and MET level was used for statistical analysis. Peak heart rates during the obstacle course simulation were significantly higher than the standard target heart rates (those at which treadmill stress tests in physicians' offices are typically stopped) (t(29) = 12.81, P < 0.001) and significantly higher than the suggested maximum of 150 beats/min during cardiac rehabilitation training (t(29) = 17.84, P < 0.001). Peak MET levels during the obstacle course simulation were also significantly higher than the goal level (8 METs) that patients typically achieve in a cardiac rehabilitation program (t(29) = 14.73, P < 0.001). We conclude that police work requires a functional capacity greater than that typically attained in traditional cardiac rehabilitation programs. Rehabilitation professionals should consider performing maximal stress tests and increasing the intensity of cardiac rehabilitation workouts to effectively train police officers who have had a cardiac event.

TabPath: interactive tables for metabolic pathway analysis.

PubMed

Moraes, Lauro Ângelo Gonçalves de; Felestrino, Érica Barbosa; Assis, Renata de Almeida Barbosa; Matos, Diogo; Lima, Joubert de Castro; Lima, Leandro de Araújo; Almeida, Nalvo Franco; Setubal, João Carlos; Garcia, Camila Carrião Machado; Moreira, Leandro Marcio

2018-03-15

Information about metabolic pathways in a comparative context is one of the most powerful tool to help the understanding of genome-based differences in phenotypes among organisms. Although several platforms exist that provide a wealth of information on metabolic pathways of diverse organisms, the comparison among organisms using metabolic pathways is still a difficult task. We present TabPath (Tables for Metabolic Pathway), a web-based tool to facilitate comparison of metabolic pathways in genomes based on KEGG. From a selection of pathways and genomes of interest on the menu, TabPath generates user-friendly tables that facilitate analysis of variations in metabolism among the selected organisms. TabPath is available at http://200.239.132.160:8686. lmmorei@gmail.com.

Citrate metabolism in blood transfusions and its relationship due to metabolic alkalosis and respiratory acidosis

PubMed Central

Li, Kai; Xu, Yuan

2015-01-01

Metabolic alkalosis commonly results from excessive hydrochloric acid (HCl), potassium (K+) and water (H2O) loss from the stomach or through the urine. The plasma anion gap increases in non-hypoproteinemic metabolic alkalosis due to an increased negative charge equivalent on albumin and the free ionized calcium (Ca++) content of plasma decreases. The mean citrate load in all patients was 8740±7027 mg from 6937±6603 mL of transfused blood products. The citrate load was significantly higher in patients with alkalosis (9164±4870 vs. 7809±3967, P < 0.05). The estimated mean total citrate administered via blood and blood products was calculated as 43.2±34.19 mg/kilogram/day. In non-massive and frequent blood transfusions, the elevated carbon dioxide output has been shown to occur. Due to citrate metabolism causes intracellular acidosis. As a result of intracellular acidosis compensation, decompensated metabolic alkalosis + respiratory acidosis and electrolyte imbalance may develop, blood transfusions may result in certain complications. PMID:26131288

Citrate metabolism in blood transfusions and its relationship due to metabolic alkalosis and respiratory acidosis.

PubMed

Li, Kai; Xu, Yuan

2015-01-01

Metabolic alkalosis commonly results from excessive hydrochloric acid (HCl), potassium (K(+)) and water (H2O) loss from the stomach or through the urine. The plasma anion gap increases in non-hypoproteinemic metabolic alkalosis due to an increased negative charge equivalent on albumin and the free ionized calcium (Ca(++)) content of plasma decreases. The mean citrate load in all patients was 8740±7027 mg from 6937±6603 mL of transfused blood products. The citrate load was significantly higher in patients with alkalosis (9164±4870 vs. 7809±3967, P < 0.05). The estimated mean total citrate administered via blood and blood products was calculated as 43.2±34.19 mg/kilogram/day. In non-massive and frequent blood transfusions, the elevated carbon dioxide output has been shown to occur. Due to citrate metabolism causes intracellular acidosis. As a result of intracellular acidosis compensation, decompensated metabolic alkalosis + respiratory acidosis and electrolyte imbalance may develop, blood transfusions may result in certain complications.

Size, shape, and stamina: the impact of left ventricular geometry on exercise capacity.

PubMed

Lam, Carolyn S P; Grewal, Jasmine; Borlaug, Barry A; Ommen, Steve R; Kane, Garvan C; McCully, Robert B; Pellikka, Patricia A

2010-05-01

Although several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction > or = 50% and no valvular disease, myocardial ischemia, or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. All of the subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60+/-14 years; 57% male) subjects, 166 (45%) had normal geometry, 106 (29%) had concentric remodeling, 40 (11%) had eccentric hypertrophy, and 54 (15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents were 9.9+/-2.8 in normal, 8.9+/-2.6 in concentric remodeling, 8.6+/-3.1 in eccentric hypertrophy, and 8.0+/-2.7 in concentric hypertrophy (all P<0.02 versus normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r=-0.14; P=0.009 and r=-0.21; P<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared with normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation, and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease.

Size, Shape and Stamina: The Impact of Left Ventricular Geometry on Exercise Capacity

PubMed Central

Lam, Carolyn S.P.; Grewal, Jasmine; Borlaug, Barry A.; Ommen, Steve R.; Kane, Garvan C.; McCully, Robert B.; Pellikka, Patricia A.

2010-01-01

While several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction ≥ 50% and no valvular disease, myocardial ischemia or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy and concentric hypertrophy. All subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60±14 years; 57% male) subjects, 166(45%) had normal geometry, 106(29%) had concentric remodeling, 40(11%) had eccentric hypertrophy and 54(15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents was 9.9±2.8 in normal, 8.9±2.6 in concentric remodeling, 8.6±3.1 in eccentric hypertrophy and 8.0±2.7 in concentric hypertrophy (all p<0.02 vs normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r= -0.14; p=0.009 and r= -0.21; p<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared to normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease. PMID:20215563

Effects of Nordic walking training on exercise capacity and fitness in men participating in early, short-term inpatient cardiac rehabilitation after an acute coronary syndrome--a controlled trial.

PubMed

Kocur, Piotr; Deskur-Smielecka, Ewa; Wilk, Malgorzata; Dylewicz, Piotr

2009-11-01

To investigate the effects of Nordic Walking training supplemental to a standard, early rehabilitation programme on exercise capacity and physical fitness in men after an acute coronary syndrome. A controlled trial. Cardiac rehabilitation service of a provincial hospital. Eighty men 2-3 weeks after an acute coronary syndrome, with good exercise tolerance. Three-week, inpatient cardiac rehabilitation programme (control group) supplemented with Nordic Walking (Nordic Walking group), or with traditional walking training (walking training group). Exercise capacity was assessed as peak energy cost (in metabolic equivalents) in symptom-limited treadmill exercise test, and physical fitness with the Fullerton Functional Fitness Test. Exercise capacity after the rehabilitation programme was higher in the Nordic Walking group than in the control group (10.8 +/- 1.8 versus 9.2 +/- 2.2 metabolic equivalents, P =0.025). The improvement in exercise capacity in the Nordic Walking group was higher than in the control group (1.8 +/- 1.5 versus 0.7 +/- 1.4 metabolic equivalents, P =0.002). In contrast to the control group, the results of all components of the Fullerton test improved in the Nordic Walking and walking training groups. After the programme, lower body endurance, and dynamic balance were significantly better in the Nordic Walking group in comparison with the walking training and control groups, and upper body endurance was significantly better in the Nordic Walking and walking training groups than in the control group. Nordic Walking may improve exercise capacity, lower body endurance and coordination of movements in patients with good exercise tolerance participating in early, short-term rehabilitation after an acute coronary syndrome.

High-fructose corn syrup and sucrose have equivalent effects on energy-regulating hormones at normal human consumption levels.

PubMed

Yu, Zhiping; Lowndes, Joshua; Rippe, James

2013-12-01

Intake of high-fructose corn syrup (HFCS) has been suggested to contribute to the increased prevalence of obesity, whereas a number of studies and organizations have reported metabolic equivalence between HFCS and sucrose. We hypothesized that HFCS and sucrose would have similar effects on energy-regulating hormones and metabolic substrates at normal levels of human consumption and that these values would not change over a 10-week, free-living period at these consumption levels. This was a randomized, prospective, double-blind, parallel group study in which 138 adult men and women consumed 10 weeks of low-fat milk sweetened with either HFCS or sucrose at levels of the 25th, 50th, and 90th percentile population consumption of fructose (the equivalent of 40, 90, or 150 g of sugar per day in a 2000-kcal diet). Before and after the 10-week intervention, 24-hour blood samples were collected. The area under the curve (AUC) for glucose, insulin, leptin, active ghrelin, triglyceride, and uric acid was measured. There were no group differences at baseline or posttesting for all outcomes (interaction, P > .05). The AUC response of glucose, active ghrelin, and uric acid did not change between baseline and posttesting (P > .05), whereas the AUC response of insulin (P < .05), leptin (P < .001), and triglyceride (P < .01) increased over the course of the intervention when the 6 groups were averaged. We conclude that there are no differences in the metabolic effects of HFCS and sucrose when compared at low, medium, and high levels of consumption. © 2013 Elsevier Inc. All rights reserved.

Perceptual learning improves visual performance in juvenile amblyopia.

PubMed

Li, Roger W; Young, Karen G; Hoenig, Pia; Levi, Dennis M

2005-09-01

To determine whether practicing a position-discrimination task improves visual performance in children with amblyopia and to determine the mechanism(s) of improvement. Five children (age range, 7-10 years) with amblyopia practiced a positional acuity task in which they had to judge which of three pairs of lines was misaligned. Positional noise was produced by distributing the individual patches of each line segment according to a Gaussian probability function. Observers were trained at three noise levels (including 0), with each observer performing between 3000 and 4000 responses in 7 to 10 sessions. Trial-by-trial feedback was provided. Four of the five observers showed significant improvement in positional acuity. In those four observers, on average, positional acuity with no noise improved by approximately 32% and with high noise by approximately 26%. A position-averaging model was used to parse the improvement into an increase in efficiency or a decrease in equivalent input noise. Two observers showed increased efficiency (51% and 117% improvements) with no significant change in equivalent input noise across sessions. The other two observers showed both a decrease in equivalent input noise (18% and 29%) and an increase in efficiency (17% and 71%). All five observers showed substantial improvement in Snellen acuity (approximately 26%) after practice. Perceptual learning can improve visual performance in amblyopic children. The improvement can be parsed into two important factors: decreased equivalent input noise and increased efficiency. Perceptual learning techniques may add an effective new method to the armamentarium of amblyopia treatments.

High energy expenditure masks low physical activity in obesity.

PubMed

DeLany, J P; Kelley, D E; Hames, K C; Jakicic, J M; Goodpaster, B H

2013-07-01

To investigate energy expenditure in lean and obese individuals, focusing particularly on physical activity and severely obese individuals. Total daily energy expenditure (TDEE) was assessed using doubly labeled water, resting metabolic rate (RMR) by indirect calorimetry, activity energy expenditure (AEE) by difference and time spent in physical activity by multisensor activity monitors. In all, 177 lean, Class I and severely obese individuals (age 31-56 years, body mass index 20-64 kg m(-2)) were analyzed. All components of energy expenditure were elevated in obese individuals. For example, TDEE was 2404±95 kcal per day in lean and 3244±48 kcal per day in Class III obese individuals. After appropriate adjustment, RMR was similar in all groups. Analysis of AEE by body weight and obesity class indicated a lower AEE in obese individuals. Confirming lower physical activity, obese individuals spent less time engaged in moderate-to-vigorous physical activity (2.7±1.3, 1.8±0.6, 2.0±1.4 and 1.2±1.0 h per day in lean, Class I, Class II and Class III individuals) and more time in sedentary behaviors. There was no indication of metabolic efficiency in even the severely obese, as adjusted RMR was similar across all groups. The higher AEE observed in the obese is consistent with a higher cost of activities due to higher body weight. However, the magnitude of the higher AEE (20-25% higher in obese individuals) is lower than expected (weight approximately 100% higher in Class III individuals). Confirming a lower volume of physical activity in the obese, the total time spent in moderate-to-vigorous physical activity and average daily metabolic equivalent of task level were lower with increasing obesity. These findings demonstrate that high body weight in obese individuals leads to a high TDEE and AEE, which masks the fact that they are less physically active, which can be influenced by duration or intensity of activity, than in lean individuals.

REGULATORY METHODS PROGRAM SUPPORT FOR NAAQSS

EPA Science Inventory

This task supports attainment determinations of the National Ambient Air Quality Standards (NAAQS) for particulate matter (PM) in the areas of development, testing, and improvement of new and current PM Federal Reference Methods (FRMs) and Federal Equivalent Methods (FEMs). The ...

Ad libitum vs. restricted fluid replacement on hydration and performance of military tasks.

PubMed

Nolte, Heinrich W; Noakes, Timothy D; Nolte, Kim

2013-02-01

The primary objective was to evaluate the effect of ad libitum vs. restricted fluid replacement protocol on hydration markers and performance in selected military tasks. The secondary objective was to determine if 300 ml x h(-1) could be considered a safe minimum fluid intake under the experimental conditions. Data were collected simulating a route march over 16 km. There were 57 subjects who participated in the study. The mean pre-exercise body mass of the ad libitum group was 70.4 +/- 13.3 (SD) kg compared to 69.3 +/- 8.9 kg in the restricted group. The mean total fluid intake of the ad libitum group was 2.1 +/- 0.9 L compared to 1.2 +/- 0.0 L in the restricted group. The ad libitum and restricted intake groups, respectively, lost a mean of 1.05 kg +/- 0.77 (1.5%) and 1.34 kg +/- 0.37 (1.9%). Calculated sweat rate was 608 +/- 93 ml x h(-1) compared to 762 +/- 162 ml x h(-1) in the ad libitum group. There were no significant differences for either urine specific gravity (USG) or urine osmolality (UOsm) before or after the exercise. It is not clear whether fluid intake and calculated sweat rates are causally related or explained by their codependence on a third variable; for example, the exercising metabolic rate. Thus, 300 ml x h(-1) intake could be considered a current safe minimum water intake for soldiers of similar mass under similar experimental conditions, namely similar exercise durations at equivalent exercise intensities in a moderate, dry climate.

Predicting free-living energy expenditure using a miniaturized ear-worn sensor: an evaluation against doubly labeled water.

PubMed

Bouarfa, Loubna; Atallah, Louis; Kwasnicki, Richard Mark; Pettitt, Claire; Frost, Gary; Yang, Guang-Zhong

2014-02-01

Accurate estimation of daily total energy expenditure (EE)is a prerequisite for assisted weight management and assessing certain health conditions. The use of wearable sensors for predicting free-living EE is challenged by consistent sensor placement, user compliance, and estimation methods used. This paper examines whether a single ear-worn accelerometer can be used for EE estimation under free-living conditions.An EE prediction model as first derived and validated in a controlled setting using healthy subjects involving different physical activities. Ten different activities were assessed showing a tenfold cross validation error of 0.24. Furthermore, the EE prediction model shows a mean absolute deviation(MAD) below 1.2 metabolic equivalent of tasks. The same model was applied to a free-living setting with a different population for further validation. The results were compared against those derived from doubly labeled water. In free-living settings, the predicted daily EE has a correlation of 0.74, p 0.008, and a MAD of 272 kcal day. These results demonstrate that laboratory-derived prediction models can be used to predict EE under free-living conditions [corrected].

Time Use and Physical Activity: A Shift Away from Movement across the Globe

PubMed Central

Ng, Shu Wen; Popkin, Barry

2012-01-01

Technology linked with reduced physical activity (PA) in occupational work, home/domestic work, and travel and increased sedentary activities, especially television viewing, dominates the globe. Using detailed historical data on time allocation, occupational distributions, energy expenditures data by activity, and time-varying measures of metabolic equivalents of task (MET) for activities when available, we measure historical and current MET by four major PA domains (occupation, home production, travel, and active leisure) and sedentary time among adults (> 18 years). Trends by domain for the United States (1965–2009), the United Kingdom (1961–2005), Brazil (2002–2007), China (1991–2009), and India (2000–2005) are presented. We also project changes in energy expenditure by domain and sedentary time (excluding sleep and personal care) to 2020 and 2030 for each of these countries. The use of previously unexplored detailed time allocation and energy expenditures and other datasets represents a useful addition to our ability to document activity and inactivity globally. Given the potential impact on weight gain and other cardiometabolic health risks, the differential declines in MET of activity and increases in sedentary time across the globe represents a major threat to global health. PMID:22694051

Neural representations of magnitude for natural and rational numbers.

PubMed

DeWolf, Melissa; Chiang, Jeffrey N; Bassok, Miriam; Holyoak, Keith J; Monti, Martin M

2016-11-01

Humans have developed multiple symbolic representations for numbers, including natural numbers (positive integers) as well as rational numbers (both fractions and decimals). Despite a considerable body of behavioral and neuroimaging research, it is currently unknown whether different notations map onto a single, fully abstract, magnitude code, or whether separate representations exist for specific number types (e.g., natural versus rational) or number representations (e.g., base-10 versus fractions). We address this question by comparing brain metabolic response during a magnitude comparison task involving (on different trials) integers, decimals, and fractions. Univariate and multivariate analyses revealed that the strength and pattern of activation for fractions differed systematically, within the intraparietal sulcus, from that of both decimals and integers, while the latter two number representations appeared virtually indistinguishable. These results demonstrate that the two major notations formats for rational numbers, fractions and decimals, evoke distinct neural representations of magnitude, with decimals representations being more closely linked to those of integers than to those of magnitude-equivalent fractions. Our findings thus suggest that number representation (base-10 versus fractions) is an important organizational principle for the neural substrate underlying mathematical cognition. Copyright © 2016 Elsevier Inc. All rights reserved.

A feasibility study on smartphone accelerometer-based recognition of household activities and influence of smartphone position.

PubMed

Della Mea, Vincenzo; Quattrin, Omar; Parpinel, Maria

2017-12-01

Obesity and physical inactivity are the most important risk factors for chronic diseases. The present study aimed at (i) developing and testing a method for classifying household activities based on a smartphone accelerometer; (ii) evaluating the influence of smartphone position; and (iii) evaluating the acceptability of wearing a smartphone for activity recognition. An Android application was developed to record accelerometer data and calculate descriptive features on 5-second time blocks, then classified with nine algorithms. Household activities were: sitting, working at the computer, walking, ironing, sweeping the floor, going down stairs with a shopping bag, walking while carrying a large box, and climbing stairs with a shopping bag. Ten volunteers carried out the activities for three times, each one with a smartphone in a different position (pocket, arm, and wrist). Users were then asked to answer a questionnaire. 1440 time blocks were collected. Three algorithms demonstrated an accuracy greater than 80% for all smartphone positions. While for some subjects the smartphone was uncomfortable, it seems that it did not really affect activity. Smartphones can be used to recognize household activities. A further development is to measure metabolic equivalent tasks starting from accelerometer data only.

A preliminary investigation of the environmental Control and Life Support Subsystems (EC/LSS) for animal and plant experiment payloads

NASA Technical Reports Server (NTRS)

Wells, H. B.

1972-01-01

A preliminary study of the environmental control and life support subsystems (EC/LSS) necessary for an earth orbital spacecraft to conduct biological experiments is presented. The primary spacecraft models available for conducting these biological experiments are the space shuttle and modular space station. The experiments would be housed in a separate module that would be contained in either the shuttle payload bay or attached to the modular space station. This module would be manned only for experiment-related tasks, and would contain a separate EC/LSS for the crew and animals. Metabolic data were tabulated on various animals that are considered useful for a typical experiment program. The minimum payload for the 30-day space shuttle module was found to require about the equivalent of a one-man EC/LSS; however, the selected two-man shuttle assemblies will give a growth and contingency factor of about 50 percent. The maximum payloads for the space station mission will require at least a seven-man EC/LSS for the laboratory colony and a nine-man EC/LSS for the centrifuge colony. There is practically no room for growth or contingencies in these areas.

Age effects shrink when motor learning is predominantly supported by nondeclarative, automatic memory processes: evidence from golf putting.

PubMed

Chauvel, Guillaume; Maquestiaux, François; Hartley, Alan A; Joubert, Sven; Didierjean, André; Masters, Rich S W

2012-01-01

Can motor learning be equivalent in younger and older adults? To address this question, 48 younger (M = 23.5 years) and 48 older (M = 65.0 years) participants learned to perform a golf-putting task in two different motor learning situations: one that resulted in infrequent errors or one that resulted in frequent errors. The results demonstrated that infrequent-error learning predominantly relied on nondeclarative, automatic memory processes whereas frequent-error learning predominantly relied on declarative, effortful memory processes: After learning, infrequent-error learners verbalized fewer strategies than frequent-error learners; at transfer, a concurrent, attention-demanding secondary task (tone counting) left motor performance of infrequent-error learners unaffected but impaired that of frequent-error learners. The results showed age-equivalent motor performance in infrequent-error learning but age deficits in frequent-error learning. Motor performance of frequent-error learners required more attention with age, as evidenced by an age deficit on the attention-demanding secondary task. The disappearance of age effects when nondeclarative, automatic memory processes predominated suggests that these processes are preserved with age and are available even early in motor learning.

Carbon Metabolic Pathways in Phototrophic Bacteria and Their Broader Evolutionary Implications

PubMed Central

Tang, Kuo-Hsiang; Tang, Yinjie J.; Blankenship, Robert Eugene

2011-01-01

Photosynthesis is the biological process that converts solar energy to biomass, bio-products, and biofuel. It is the only major natural solar energy storage mechanism on Earth. To satisfy the increased demand for sustainable energy sources and identify the mechanism of photosynthetic carbon assimilation, which is one of the bottlenecks in photosynthesis, it is essential to understand the process of solar energy storage and associated carbon metabolism in photosynthetic organisms. Researchers have employed physiological studies, microbiological chemistry, enzyme assays, genome sequencing, transcriptomics, and 13C-based metabolomics/fluxomics to investigate central carbon metabolism and enzymes that operate in phototrophs. In this report, we review diverse CO2 assimilation pathways, acetate assimilation, carbohydrate catabolism, the tricarboxylic acid cycle and some key, and/or unconventional enzymes in central carbon metabolism of phototrophic microorganisms. We also discuss the reducing equivalent flow during photoautotrophic and photoheterotrophic growth, evolutionary links in the central carbon metabolic network, and correlations between photosynthetic and non-photosynthetic organisms. Considering the metabolic versatility in these fascinating and diverse photosynthetic bacteria, many essential questions in their central carbon metabolism still remain to be addressed. PMID:21866228

Cognitive Maturity, Stressful Events and Metabolic Control in Adolescents with Diabetes.

ERIC Educational Resources Information Center

Ingersoll, Gary M.; And Others

Management of insulin dependent diabetes mellitus (IDDM) is a complex task that requires the adolescent with IDDM recognize the interaction between diet, exercise, stress, emotions, and insulin dosage. With regularity, however, adolescents with IDDM are shown to be in less good metabolic control than younger children or young adults. The study…

A Novel Method for Characterizing Spacesuit Mobility Through Metabolic Cost

NASA Technical Reports Server (NTRS)

McFarland, Shane M.; Norcross, Jason R.

2014-01-01

Historically, spacesuit mobility has been characterized by directly measuring both range of motion and joint torque of individual anatomic joints. The work detailed herein aims to improve on this method, which is often prone to uncertainly, lack of repeatability, and a general lack of applicability to real-world functional tasks. Specifically, the goal of this work is to characterize suited mobility performance by directly measuring the metabolic performance of the occupant. Pilot testing was conducted in 2013, employing three subjects performing a range of functional tasks in two different suits prototypes, the Mark III and Z-1. Cursory analysis of the results shows the approach has merit, with consistent performance trends toward one suit over the other. Forward work includes the need to look at more subjects, a refined task set, and another suit in a different mass/mobility regime to validate the approach.

A method of evaluating efficiency during space-suited work in a neutral buoyancy environment

NASA Technical Reports Server (NTRS)

Greenisen, Michael C.; West, Phillip; Newton, Frederick K.; Gilbert, John H.; Squires, William G.

1991-01-01

The purpose was to investigate efficiency as related to the work transmission and the metabolic cost of various extravehicular activity (EVA) tasks during simulated microgravity (whole body water immersion) using three space suits. Two new prototype space station suits, AX-5 and MKIII, are pressurized at 57.2 kPa and were tested concurrently with the operationally used 29.6 kPa shuttle suit. Four male astronauts were asked to perform a fatigue trial on four upper extremity exercises during which metabolic rate and work output were measured and efficiency was calculated in each suit. The activities were selected to simulate actual EVA tasks. The test article was an underwater dynamometry system to which the astronauts were secured by foot restraints. All metabolic data was acquired, calculated, and stored using a computerized indirect calorimetry system connected to the suit ventilation/gas supply control console. During the efficiency testing, steady state metabolic rate could be evaluated as well as work transmitted to the dynamometer. Mechanical efficiency could then be calculated for each astronaut in each suit performing each movement.

GSM mobile phone radiation suppresses brain glucose metabolism

PubMed Central

Kwon, Myoung Soo; Vorobyev, Victor; Kännälä, Sami; Laine, Matti; Rinne, Juha O; Toivonen, Tommi; Johansson, Jarkko; Teräs, Mika; Lindholm, Harri; Alanko, Tommi; Hämäläinen, Heikki

2011-01-01

We investigated the effects of mobile phone radiation on cerebral glucose metabolism using high-resolution positron emission tomography (PET) with the 18F-deoxyglucose (FDG) tracer. A long half-life (109 minutes) of the 18F isotope allowed a long, natural exposure condition outside the PET scanner. Thirteen young right-handed male subjects were exposed to a pulse-modulated 902.4 MHz Global System for Mobile Communications signal for 33 minutes, while performing a simple visual vigilance task. Temperature was also measured in the head region (forehead, eyes, cheeks, ear canals) during exposure. 18F-deoxyglucose PET images acquired after the exposure showed that relative cerebral metabolic rate of glucose was significantly reduced in the temporoparietal junction and anterior temporal lobe of the right hemisphere ipsilateral to the exposure. Temperature rise was also observed on the exposed side of the head, but the magnitude was very small. The exposure did not affect task performance (reaction time, error rate). Our results show that short-term mobile phone exposure can locally suppress brain energy metabolism in humans. PMID:21915135

A metabolomic study of preterm and term human and formula milk by proton MRS analysis: preliminary results.

PubMed

Longini, Mariangela; Tataranno, Maria Luisa; Proietti, Fabrizio; Tortoriello, Mario; Belvisi, Elisa; Vivi, Antonio; Tassini, Maria; Perrone, Serafina; Buonocore, Giuseppe

2014-10-01

To investigate changes in global metabolic profile between: 1 - breast milk and formula milk, 2 - breast milk from mothers delivering at different gestational age (GA) collected within one week from delivery, and then week by week until term equivalent age. Proton magnetic resonance spectroscopy (MRS) was used to analyze the water-soluble and lipid fractions extracted from 50 milk samples, 46 human milk at different GA, from 23 weeks of gestation until term equivalent age and four different formula milks. The formula milk for premature infants was the most similar to breast milk of preterm babies. Breast milk showed higher lactose concentrations than formula milk, that conversely presented higher galactose 1-phosphate and maltose concentrations. Mother's milk of very preterm babies (23-25 wks of GA) showed a different metabolic profile from preterm infants ≥29 wks of GA with a subsequent trend to similarity around the 30th week of post-natal age. Breast milk from preterm infants of 29-34 wks, collected up to 40 wks of post-natal age showed a temporal change over the first three weeks of lactation, approaching to zero with the achievement of term age. Metabolome is a promising tool to study human and artificial milk global metabolic profile.

Electroencephalographic Monitoring of Cognitive Fatigue

NASA Technical Reports Server (NTRS)

Montgomery, Leslie D.; Montgomery, Richard W.; Ku, Yu-Tsuan E.; Luna, Bernadette

2000-01-01

Mental exhaustion often poses a serious risk, even when performance is not apparently degraded. When such fatigue is associated with sustained performance of a single type of cognitive task it may be related to the metabolic energy required for sustained activation of cortical fields specialized for that task. The objective of this study was to adapt EEG to monitor cortical energy dissipation at a functionally specialized site over a long period of repetitive performance of a cognitive task.

Montmorency Tart cherries (Prunus cerasus L.) modulate vascular function acutely, in the absence of improvement in cognitive performance.

PubMed

Keane, K M; Haskell-Ramsay, C F; Veasey, R C; Howatson, G

2016-12-01

Cerebral blood volume and metabolism of oxygen decline as part of human ageing, and this has been previously shown to be related to cognitive decline. There is some evidence to suggest that polyphenol-rich foods can play an important role in delaying the onset or halting the progression of age-related health disorders such as CVD and Alzheimer's disease and to improve cognitive function. In the present study, an acute, placebo-controlled, double-blinded, cross-over, randomised Latin-square design study with a washout period of at least 14 d was conducted on twenty-seven, middle-aged (defined as 45-60 years) volunteers. Participants received either a 60 ml dose of Montmorency tart cherry concentrate (MC), which contained 68·0 (sd 0·26) mg cyanidin-3-glucoside/l, 160·75 (sd 0·55) mean gallic acid equivalent/l and 0·59 (sd 0·02) mean Trolox equivalent/l, respectively, or a placebo. Cerebrovascular responses, cognitive performance and blood pressure were assessed at baseline and 1, 2, 3 and 5 h following consumption. There were significant differences in concentrations of total Hb and oxygenated Hb during the task period 1 h after MC consumption (P≤0·05). Furthermore, MC consumption significantly lowered systolic blood pressure (P≤0·05) over a period of 3 h, with peak reductions of 6±2 mmHg at 1 h after MC consumption relative to the placebo. Cognitive function and mood were not affected. These results show that a single dose of MC concentrate can modulate certain variables of vascular function; however, this does not translate to improvements in cognition or mood.

The role of metacognition in prospective memory: anticipated task demands influence attention allocation strategies.

PubMed

Rummel, Jan; Meiser, Thorsten

2013-09-01

The present study investigates how individuals distribute their attentional resources between a prospective memory task and an ongoing task. Therefore, metacognitive expectations about the attentional demands of the prospective-memory task were manipulated while the factual demands were held constant. In Experiments 1a and 1b, we found attentional costs from a prospective-memory task with low factual demands to be significantly reduced when information about the low to-be-expected demands were provided, while prospective-memory performance remained largely unaffected. In Experiment 2, attentional monitoring in a more demanding prospective-memory task also varied with information about the to-be-expected demands (high vs. low) and again there were no equivalent changes in prospective-memory performance. These findings suggest that attention-allocation strategies of prospective memory rely on metacognitive expectations about prospective-memory task demands. Furthermore, the results suggest that attentional monitoring is only functional for prospective memory to the extent to which anticipated task demands reflect objective task demands. Copyright © 2013 Elsevier Inc. All rights reserved.

The Costs and Benefits of Testing and Guessing on Recognition Memory

PubMed Central

Huff, Mark J.; Balota, David A.; Hutchison, Keith A.

2016-01-01

We examined whether two types of interpolated tasks (i.e., retrieval-practice via free recall or guessing a missing critical item) improved final recognition for related and unrelated word lists relative to restudying or completing a filler task. Both retrieval-practice and guessing tasks improved correct recognition relative to restudy and filler tasks, particularly when study lists were semantically related. However, both retrieval practice and guessing also generally inflated false recognition for the non-presented critical words. These patterns were found when final recognition was completed during a short delay within the same experimental session (Experiment 1) and following a 24-hr delay (Experiment 2). In Experiment 3, task instructions were presented randomly after each list to determine whether retrieval-practice and guessing effects were influenced by task-expectancy processes. In contrast to Experiments 1 and 2, final recognition following retrieval practice and guessing was equivalent to restudy, suggesting that the observed retrieval-practice and guessing advantages were in part due to preparatory task-based processing during study. PMID:26950490

PHYSICAL ACTIVITY INDEX FOR CHILDREN: A COMPARISON OF LITERATURE VALUES AND EPA'S CHAD

EPA Science Inventory

The physical activity index (PAI) is a measure of an individual's energy expenditure level (and thus oxygen consumption) calculated as a time-weighted average of metabolic equivalents (METS) over the individual's activities. Many exposure models rely upon EPA's CHAD data base to ...

The Use of the MASCOT Philosophy for the Construction of Ada Programs,

DTIC Science & Technology

1983-10-01

dependent units must be recompiled. Because of Ada’s commitment to abstract data types tasks are treated as data types with certain restrictions. A task...3.3.3.1.4 End of Slice Action The scheduling algorithm determines, for each type of Slice termination, how the Scheduler treats Activities whose Slice has...Pools. The MASCOT Machine treats them as constructionally equivalent (refer 3.3.1.1.1). Because of the constraints brought in by the formulation of

Parts and 'holes': gaps in rational number sense among children with vs. without mathematical learning disabilities.

PubMed

Mazzocco, Michèle M M; Devlin, Kathleen T

2008-09-01

Many middle-school students struggle with decimals and fractions, even if they do not have a mathematical learning disability (MLD). In the present longitudinal study, we examined whether children with MLD have weaker rational number knowledge than children whose difficulty with rational numbers occurs in the absence of MLD. We found that children with MLD failed to accurately name decimals, to correctly rank order decimals and/or fractions, and to identify equivalent ratios (e.g. 0.5 = 1/2); they also 'identified' incorrect equivalents (e.g. 0.05 = 0.50). Children with low math achievement but no MLD accurately named decimals and identified equivalent pairs, but failed to correctly rank order decimals and fractions. Thus failure to accurately name decimals was an indicator of MLD; but accurate naming was no guarantee of rational number knowledge - most children who failed to correctly rank order fractions and decimals tests passed the naming task. Most children who failed the ranking tests at 6th grade also failed at 8th grade. Our findings suggest that a simple task involving naming and rank ordering fractions and decimals may be a useful addition to in-class assessments used to determine children's learning of rational numbers.

ReMatch: a web-based tool to construct, store and share stoichiometric metabolic models with carbon maps for metabolic flux analysis.

PubMed

Pitkänen, Esa; Akerlund, Arto; Rantanen, Ari; Jouhten, Paula; Ukkonen, Esko

2008-08-25

ReMatch is a web-based, user-friendly tool that constructs stoichiometric network models for metabolic flux analysis, integrating user-developed models into a database collected from several comprehensive metabolic data resources, including KEGG, MetaCyc and CheBI. Particularly, ReMatch augments the metabolic reactions of the model with carbon mappings to facilitate (13)C metabolic flux analysis. The construction of a network model consisting of biochemical reactions is the first step in most metabolic modelling tasks. This model construction can be a tedious task as the required information is usually scattered to many separate databases whose interoperability is suboptimal, due to the heterogeneous naming conventions of metabolites in different databases. Another, particularly severe data integration problem is faced in (13)C metabolic flux analysis, where the mappings of carbon atoms from substrates into products in the model are required. ReMatch has been developed to solve the above data integration problems. First, ReMatch matches the imported user-developed model against the internal ReMatch database while considering a comprehensive metabolite name thesaurus. This, together with wild card support, allows the user to specify the model quickly without having to look the names up manually. Second, ReMatch is able to augment reactions of the model with carbon mappings, obtained either from the internal database or given by the user with an easy-touse tool. The constructed models can be exported into 13C-FLUX and SBML file formats. Further, a stoichiometric matrix and visualizations of the network model can be generated. The constructed models of metabolic networks can be optionally made available to the other users of ReMatch. Thus, ReMatch provides a common repository for metabolic network models with carbon mappings for the needs of metabolic flux analysis community. ReMatch is freely available for academic use at http://www.cs.helsinki.fi/group/sysfys/software/rematch/.

Using EEG To Detect and Monitor Mental Fatigue

NASA Technical Reports Server (NTRS)

Montgomery, Leslie; Luna, Bernadette; Trejo, Leonard J.; Montgomery, Richard

2001-01-01

This project aims to develop EEG-based methods for detecting and monitoring mental fatigue. Mental fatigue poses a serious risk, even when performance is not apparently degraded. When such fatigue is associated with sustained performance of a single type of cognitive task it may be related to the metabolic energy required for sustained activation of cortical areas specialized for that task. The objective of this study was to adapt EEG to monitor cortical energy over a long period of performance of a cognitive task. Multielectrode event related potentials (ERPs) were collected every 15 minutes in nine subjects who performed a mental arithmetic task (algebraic sum of four randomly generated negative or positive digits). A new problem was presented on a computer screen 0.5 seconds after each response; some subjects endured for as long as three hours. ERPs were transformed to a quantitative measure of scalp electrical field energy. The average energy level at electrode P3 (near the left angular gyrus), 100-300 msec latency, was compared over the series of ERPs. For most subjects, scalp energy density at P3 gradually fell over the period of task performance and dramatically increased just before the subject was unable to continue the task. This neural response can be simulated for individual subjects using, a differential equation model in which it is assumed that the mental arithmetic task requires a commitment of metabolic energy that would otherwise be used for brain activities that are temporarily neglected. Their cumulative neglect eventually requires a reallocation of energy away from the mental arithmetic task.

Reconstruction and flux analysis of coupling between metabolic pathways of astrocytes and neurons: application to cerebral hypoxia

PubMed Central

Çakιr, Tunahan; Alsan, Selma; Saybaşιlι, Hale; Akιn, Ata; Ülgen, Kutlu Ö

2007-01-01

Background It is a daunting task to identify all the metabolic pathways of brain energy metabolism and develop a dynamic simulation environment that will cover a time scale ranging from seconds to hours. To simplify this task and make it more practicable, we undertook stoichiometric modeling of brain energy metabolism with the major aim of including the main interacting pathways in and between astrocytes and neurons. Model The constructed model includes central metabolism (glycolysis, pentose phosphate pathway, TCA cycle), lipid metabolism, reactive oxygen species (ROS) detoxification, amino acid metabolism (synthesis and catabolism), the well-known glutamate-glutamine cycle, other coupling reactions between astrocytes and neurons, and neurotransmitter metabolism. This is, to our knowledge, the most comprehensive attempt at stoichiometric modeling of brain metabolism to date in terms of its coverage of a wide range of metabolic pathways. We then attempted to model the basal physiological behaviour and hypoxic behaviour of the brain cells where astrocytes and neurons are tightly coupled. Results The reconstructed stoichiometric reaction model included 217 reactions (184 internal, 33 exchange) and 216 metabolites (183 internal, 33 external) distributed in and between astrocytes and neurons. Flux balance analysis (FBA) techniques were applied to the reconstructed model to elucidate the underlying cellular principles of neuron-astrocyte coupling. Simulation of resting conditions under the constraints of maximization of glutamate/glutamine/GABA cycle fluxes between the two cell types with subsequent minimization of Euclidean norm of fluxes resulted in a flux distribution in accordance with literature-based findings. As a further validation of our model, the effect of oxygen deprivation (hypoxia) on fluxes was simulated using an FBA-derivative approach, known as minimization of metabolic adjustment (MOMA). The results show the power of the constructed model to simulate disease behaviour on the flux level, and its potential to analyze cellular metabolic behaviour in silico. Conclusion The predictive power of the constructed model for the key flux distributions, especially central carbon metabolism and glutamate-glutamine cycle fluxes, and its application to hypoxia is promising. The resultant acceptable predictions strengthen the power of such stoichiometric models in the analysis of mammalian cell metabolism. PMID:18070347

75 FR 26733 - Preventing Contraband Cell Phone Use in Prisons

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-12

... alternative approach could be to specify maximum allowable equivalent isotropically radiated power (EIRP... technical approaches to preventing contraband cell phone use in prisons. Congress tasked NTIA with..., wireless technology solutions. NTIA understands that a number of technological approaches exist that could...

Physical Activity of Parents of Children with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Haegele, Justin A.; Lee, Jihyun; Chang, Seung Ho

2017-01-01

A preliminary study was conducted to investigate the physical activity status of parents of children with autism spectrum disorder (ASD) and related demographic characteristics. Thirty-four parents completed the IPAQ-S and demographic survey. Mean metabolic equivalent-minutes per week (MET-min/week) across participants was 3,371. Significant…

Learning and generalization from reward and punishment in opioid addiction

PubMed Central

Myers, Catherine E.; Rego, Janice; Haber, Paul; Morley, Kirsten; Beck, Kevin D.; Hogarth, Lee; Moustafa, Ahmed A.

2016-01-01

This study adapts a widely-used acquired equivalence paradigm to investigate how opioid-addicted individuals learn from positive and negative feedback, and how they generalize this learning. The opioid-addicted group consisted of 33 participants with a history of heroin dependency currently in a methadone maintenance program; the control group consisted of 32 healthy participants without a history of drug addiction. All participants performed a novel variant of the acquired equivalence task, where they learned to map some stimuli to correct outcomes in order to obtain reward, and to map other stimuli to correct outcomes in order to avoid punishment; some stimuli were implicitly “equivalent” in the sense of being paired with the same outcome. On the initial training phase, both groups performed similarly on learning to obtain reward, but as memory load grew, the control group outperformed the addicted group on learning to avoid punishment. On a subsequent testing phase, the addicted and control groups performed similarly on retention trials involving previously-trained stimulus-outcome pairs, as well as on generalization trials to assess acquired equivalence. Since prior work with acquired equivalence tasks has associated stimulus-outcome learning with the nigrostriatal dopamine system, and generalization with the hippocampal region, the current results are consistent with basal ganglia dysfunction in the opioid-addicted patients. Further, a selective deficit in learning from punishment could contribute to processes by which addicted individuals continue to pursue drug use even at the cost of negative consequences such as loss of income and the opportunity to engage in other life activities. PMID:27641323

Task Equivalence for Model and Human-Observer Comparisons in SPECT Localization Studies

NASA Astrophysics Data System (ADS)

Sen, Anando; Kalantari, Faraz; Gifford, Howard C.

2016-06-01

While mathematical model observers are intended for efficient assessment of medical imaging systems, their findings should be relevant for human observers as the primary clinical end users. We have investigated whether pursuing equivalence between the model and human-observer tasks can help ensure this goal. A localization receiver operating characteristic (LROC) study tested prostate lesion detection in simulated In-111 SPECT imaging with anthropomorphic phantoms. The test images were 2D slices extracted from reconstructed volumes. The iterative ordered sets expectation-maximization (OSEM) reconstruction algorithm was used with Gaussian postsmoothing. Variations in the number of iterations and the level of postfiltering defined the test strategies in the study. Human-observer performance was compared with that of a visual-search (VS) observer, a scanning channelized Hotelling observer, and a scanning channelized nonprewhitening (CNPW) observer. These model observers were applied with precise information about the target regions of interest (ROIs). ROI knowledge was a study variable for the human observers. In one study format, the humans read the SPECT image alone. With a dual-modality format, the SPECT image was presented alongside an anatomical image slice extracted from the density map of the phantom. Performance was scored by area under the LROC curve. The human observers performed significantly better with the dual-modality format, and correlation with the model observers was also improved. Given the human-observer data from the SPECT study format, the Pearson correlation coefficients for the model observers were 0.58 (VS), -0.12 (CH), and -0.23 (CNPW). The respective coefficients based on the human-observer data from the dual-modality study were 0.72, 0.27, and -0.11. These results point towards the continued development of the VS observer for enhancing task equivalence in model-observer studies.

The Status of Rapid Response Learning in Aging

PubMed Central

Dew, Ilana T. Z.; Giovanello, Kelly S.

2010-01-01

Strong evidence exists for an age-related impairment in associative processing under intentional encoding and retrieval conditions, but the status of incidental associative processing has been less clear. Two experiments examined the effects of age on rapid response learning – the incidentally learned stimulus-response association that results in a reduction in priming when a learned response becomes inappropriate for a new task. Specifically, we tested whether priming was equivalently sensitive in both age groups to reversing the task-specific decision cue. Experiment 1 showed that cue inversion reduced priming in both age groups using a speeded inside/outside classification task, and in Experiment 2 cue inversion eliminated priming on an associative version of this task. Thus, the ability to encode an association between a stimulus and its initial task-specific response appears to be preserved in aging. These findings provide an important example of a form of associative processing that is unimpaired in older adults. PMID:20853961

The cochlear CRF signaling systems and their mechanisms of action in modulating cochlear sensitivity and protection against trauma

PubMed Central

Graham, Christine E.; Basappa, Johnvesly; Turcan, Sevin; Vetter, Douglas E.

2011-01-01

A key requirement for encoding the auditory environment is the ability to dynamically alter cochlear sensitivity. However, merely attaining a steady state of maximal sensitivity is not a viable solution since the sensory cells and ganglion cells of the cochlea are prone to damage following exposure to loud sound. Most often, such damage is via initial metabolic insult that can lead to cellular death. Thus, establishing the highest sensitivity must be balanced with protection against cellular metabolic damage that can lead to loss of hair cells and ganglion cells, resulting in loss of frequency representation. While feedback mechanisms are known to exist in the cochlea that alter sensitivity, they respond only after stimulus encoding, allowing potentially damaging sounds to impact the inner ear at times coincident with increased sensitivity. Thus, questions remain concerning the endogenous signaling systems involved in dynamic modulation of cochlear sensitivity and protection against metabolic stress. Understanding endogenous signaling systems involved in cochlear protection may lead to new strategies and therapies for prevention of cochlear damage and consequent hearing loss. We have recently discovered a novel cochlear signaling system that is molecularly equivalent to the classic hypothalamic-pituitary-adrenal (HPA) axis. This cochlear HPA-equivalent system functions to balance auditory sensitivity and susceptibility to noise-induced hearing loss, and also protects against cellular metabolic insults resulting from exposures to ototoxic drugs. We review the anatomy, physiology, and cellular signaling of this system, and compare it to similar signaling in other organs/tissues of the body. PMID:21909974

Comparative energetics of carbon storage molecules in green algae

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

McKie-Krisberg, Zaid M.; Laurens, Lieve M. L.; Huang, Andy

Several members of the green algae possess the ability to produce lipids and/or high value compounds in significant quantities. While for several of these green algal species induction of increased lipid production has been shown, and cultivation of species for high value molecules occurs at production scale, the molecular mechanisms governing over-accumulation of molecules synthesized from isoprenoid precursors, carotenoids, for example, have received far less attention. Here, we present a calculation of the required ATP equivalencies per carbon atom and reducing power equivalencies as NADH/NADPH (NAD(P)H) per carbon atom for the isoprenoid molecules ..beta..-carotene (C40), astaxanthin (C40), and squalene (C30).more » We compared energetic requirements of carbohydrates, triacylglycerol, and isoprenoid molecules under a gradient of conditions of cellular stress. Our calculations revealed slightly less ATP and NAD(P)H equivalency per carbon atom between triacylglycerol and the three isoprenoid molecules. Based on our results, we propose that the driving force for differences in accumulation patterns of carotenoids vs. triacylglycerols in algal cells under stress is largely dependent on the presence and regulation of bypass mechanisms at metabolic junction bottlenecks, like pyruvate dehydrogenase (PDH), within particular species. We provide a discussion of several molecular mechanisms that may influence carbon partitioning within different groups of green algae, including metabolic inhibition through accumulation of specific substrates related to ATP and reducing equivalent production (NAD(P)H) as well as cellular compartmentalization. This work contributes to the ongoing discussion of cellular homeostatic regulation during stress, as well as the potential mechanisms driving long-term carbon storage as it relates to energy and redox states within the algal cell.« less

Comparative energetics of carbon storage molecules in green algae

DOE PAGES

McKie-Krisberg, Zaid M.; Laurens, Lieve M. L.; Huang, Andy; ...

2018-02-28

Several members of the green algae possess the ability to produce lipids and/or high value compounds in significant quantities. While for several of these green algal species induction of increased lipid production has been shown, and cultivation of species for high value molecules occurs at production scale, the molecular mechanisms governing over-accumulation of molecules synthesized from isoprenoid precursors, carotenoids, for example, have received far less attention. Here, we present a calculation of the required ATP equivalencies per carbon atom and reducing power equivalencies as NADH/NADPH (NAD(P)H) per carbon atom for the isoprenoid molecules ..beta..-carotene (C40), astaxanthin (C40), and squalene (C30).more » We compared energetic requirements of carbohydrates, triacylglycerol, and isoprenoid molecules under a gradient of conditions of cellular stress. Our calculations revealed slightly less ATP and NAD(P)H equivalency per carbon atom between triacylglycerol and the three isoprenoid molecules. Based on our results, we propose that the driving force for differences in accumulation patterns of carotenoids vs. triacylglycerols in algal cells under stress is largely dependent on the presence and regulation of bypass mechanisms at metabolic junction bottlenecks, like pyruvate dehydrogenase (PDH), within particular species. We provide a discussion of several molecular mechanisms that may influence carbon partitioning within different groups of green algae, including metabolic inhibition through accumulation of specific substrates related to ATP and reducing equivalent production (NAD(P)H) as well as cellular compartmentalization. This work contributes to the ongoing discussion of cellular homeostatic regulation during stress, as well as the potential mechanisms driving long-term carbon storage as it relates to energy and redox states within the algal cell.« less

Simultaneous Validation of Seven Physical Activity Questionnaires Used in Japanese Cohorts for Estimating Energy Expenditure: A Doubly Labeled Water Study.

PubMed

Sasai, Hiroyuki; Nakata, Yoshio; Murakami, Haruka; Kawakami, Ryoko; Nakae, Satoshi; Tanaka, Shigeho; Ishikawa-Takata, Kazuko; Yamada, Yosuke; Miyachi, Motohiko

2018-04-28

Physical activity questionnaires (PAQs) used in large-scale Japanese cohorts have rarely been simultaneously validated against the gold standard doubly labeled water (DLW) method. This study examined the validity of seven PAQs used in Japan for estimating energy expenditure against the DLW method. Twenty healthy Japanese adults (9 men; mean age, 32.4 [standard deviation {SD}, 9.4] years, mainly researchers and students) participated in this study. Fifteen-day daily total energy expenditure (TEE) and basal metabolic rate (BMR) were measured using the DLW method and a metabolic chamber, respectively. Activity energy expenditure (AEE) was calculated as TEE - BMR - 0.1 × TEE. Seven PAQs were self-administered to estimate TEE and AEE. The mean measured values of TEE and AEE were 2,294 (SD, 318) kcal/day and 721 (SD, 161) kcal/day, respectively. All of the PAQs indicated moderate-to-strong correlations with the DLW method in TEE (rho = 0.57-0.84). Two PAQs (Japan Public Health Center Study [JPHC]-PAQ Short and JPHC-PAQ Long) showed significant equivalence in TEE and moderate intra-class correlation coefficients (ICC). None of the PAQs showed significantly equivalent AEE estimates, with differences ranging from -547 to 77 kcal/day. Correlations and ICCs in AEE were mostly weak or fair (rho = 0.02-0.54, and ICC = 0.00-0.44). Only JPHC-PAQ Short provided significant and fair agreement with the DLW method. TEE estimated by the PAQs showed moderate or strong correlations with the results of DLW. Two PAQs showed equivalent TEE and moderate agreement. None of the PAQs showed equivalent AEE estimation to the gold standard, with weak-to-fair correlations and agreements. Further studies with larger sample sizes are needed to confirm these findings.

Nutritional assessment and therapy in COPD: a European Respiratory Society statement.

PubMed

Schols, Annemie M; Ferreira, Ivone M; Franssen, Frits M; Gosker, Harry R; Janssens, Wim; Muscaritoli, Maurizio; Pison, Christophe; Rutten-van Mölken, Maureen; Slinde, Frode; Steiner, Michael C; Tkacova, Ruzena; Singh, Sally J

2014-12-01

Nutrition and metabolism have been the topic of extensive scientific research in chronic obstructive pulmonary disease (COPD) but clinical awareness of the impact dietary habits, nutritional status and nutritional interventions may have on COPD incidence, progression and outcome is limited. A multidisciplinary Task Force was created by the European Respiratory Society to deliver a summary of the evidence and description of current practice in nutritional assessment and therapy in COPD, and to provide directions for future research. Task Force members conducted focused reviews of the literature on relevant topics, advised by a methodologist. It is well established that nutritional status, and in particular abnormal body composition, is an important independent determinant of COPD outcome. The Task Force identified different metabolic phenotypes of COPD as a basis for nutritional risk profile assessment that is useful in clinical trial design and patient counselling. Nutritional intervention is probably effective in undernourished patients and probably most when combined with an exercise programme. Providing evidence of cost-effectiveness of nutritional intervention is required to support reimbursement and thus increase access to nutritional intervention. Overall, the evidence indicates that a well-balanced diet is beneficial to all COPD patients, not only for its potential pulmonary benefits, but also for its proven benefits in metabolic and cardiovascular risk. ©ERS 2014.

Different macaque models of cognitive aging exhibit task-dependent behavioral disparities.

PubMed

Comrie, Alison E; Gray, Daniel T; Smith, Anne C; Barnes, Carol A

2018-05-15

Deficits in cognitive functions that rely on the integrity of the frontal and temporal lobes are characteristic of normative human aging. Due to similar aging phenotypes and homologous cortical organization between nonhuman primates and humans, several species of macaque monkeys are used as models to explore brain senescence. These macaque species are typically regarded as equivalent models of cognitive aging, yet no direct comparisons have been made to support this assumption. Here we used adult and aged rhesus and bonnet macaques (Macaca mulatta and Macaca radiata) to characterize the effect of age on acquisition and retention of information across delays in a battery of behavioral tasks that rely on prefrontal cortex and medial temporal lobe networks. The cognitive functions that were tested include visuospatial short-term memory, object recognition memory, and object-reward association memory. In general, bonnet macaques at all ages outperformed rhesus macaques on tasks thought to rely primarily on the prefrontal cortex, and were more resilient to age-related deficits in these behaviors. On the other hand, both species were comparably impaired by age on tasks thought to preferentially engage the medial temporal lobe. Together, these results suggest that rhesus and bonnet macaques are not equivalent models of cognitive aging and highlight the value of cross-species comparisons. These observations should enable improved design and interpretation of future experiments aimed at understanding changes in cognition across the lifespan. Copyright © 2018 Elsevier B.V. All rights reserved.

Sensory Substitution: The Spatial Updating of Auditory Scenes "Mimics" the Spatial Updating of Visual Scenes.

PubMed

Pasqualotto, Achille; Esenkaya, Tayfun

2016-01-01

Visual-to-auditory sensory substitution is used to convey visual information through audition, and it was initially created to compensate for blindness; it consists of software converting the visual images captured by a video-camera into the equivalent auditory images, or "soundscapes". Here, it was used by blindfolded sighted participants to learn the spatial position of simple shapes depicted in images arranged on the floor. Very few studies have used sensory substitution to investigate spatial representation, while it has been widely used to investigate object recognition. Additionally, with sensory substitution we could study the performance of participants actively exploring the environment through audition, rather than passively localizing sound sources. Blindfolded participants egocentrically learnt the position of six images by using sensory substitution and then a judgment of relative direction task (JRD) was used to determine how this scene was represented. This task consists of imagining being in a given location, oriented in a given direction, and pointing towards the required image. Before performing the JRD task, participants explored a map that provided allocentric information about the scene. Although spatial exploration was egocentric, surprisingly we found that performance in the JRD task was better for allocentric perspectives. This suggests that the egocentric representation of the scene was updated. This result is in line with previous studies using visual and somatosensory scenes, thus supporting the notion that different sensory modalities produce equivalent spatial representation(s). Moreover, our results have practical implications to improve training methods with sensory substitution devices (SSD).

Operativity and the Superordinate Categorization of Artifacts.

ERIC Educational Resources Information Center

Ricco, Robert B.; Beilin, Harry

1992-01-01

The relative consistency in categorization by age-equivalent groups of preoperational and concrete-operational first graders was assessed across two categorization tasks employing color drawings of exemplars of superordinate artifact categories. Results are discussed in terms of the utilization and acquisition of knowledge about superordinate…

Of Carts, Horses, and Trojan Gifts: The Transformative Task of Prior Learning Assessment.

ERIC Educational Resources Information Center

Kytle, Jackson; Zencey, Eric

1994-01-01

Discusses the prevailing conventions of portfolio assessment specifically where experiential learning is tied to course equivalents. Suggests that further discussion is needed about prior learning assessment, traditional education, and how to use experience in to advance understanding of learning. (JOW)

Delayed benefit of naps on motor learning in preschool children.

PubMed

Desrochers, Phillip C; Kurdziel, Laura B F; Spencer, Rebecca M C

2016-03-01

Sleep benefits memory consolidation across a variety of domains in young adults. However, while declarative memories benefit from sleep in young children, such improvements are not consistently seen for procedural skill learning. Here we examined whether performance improvements on a procedural task, although not immediately observed, are evident after a longer delay when augmented by overnight sleep (24 h after learning). We trained 47 children, aged 33-71 months, on a serial reaction time task and, using a within-subject design, evaluated performance at three time points: immediately after learning, after a daytime nap (nap condition) or equivalent wake opportunity (wake condition), and 24 h after learning. Consistent with previous studies, performance improvements following the nap did not differ from performance improvements following an equivalent interval spent awake. However, significant benefits of the nap were found when performance was assessed 24 h after learning. This research demonstrates that motor skill learning is benefited by sleep, but that this benefit is only evident after an extended period of time.

Metabolic Expenditures During Extravehicular Activity: Spaceflight versus Ground-based Simulation

NASA Technical Reports Server (NTRS)

Klein, Jill; Conkin, Johnny; Gernhardt, Michael; Srinivasan, Ramachandra

2008-01-01

In general metabolic rates tend to be higher in NBL than in flight: a) Restraint method dependent; b) Significant differences between the NBL and flight for BRT and APFR (buoyancy effects); and c) No significant difference between NBL and flight for free float and SRMS/SSRMS operations. The total metabolic energy expenditure for a given task and for the EVA as a whole are similar between NBL and flight: a) NBL metabolic rates are higher, but training EVAs are constrained to 5 hours; and b) Flight metabolic rates are lower, but the EVAs are typically an hour or more longer in duration. NBL metabolic rates provide a useful operational tool for flight planning. Quantifying differences and similarities between training and flight improves knowledge for preparation of safe and efficient EVAs.

Attentional blink in children with attention deficit hyperactivity disorder.

PubMed

Amador-Campos, Juan A; Aznar-Casanova, J Antonio; Bezerra, Izabela; Torro-Alves, Nelson; Sánchez, Manuel M

2015-01-01

To explore the temporal mechanism of attention in children with attention deficit hyperactivity disorder (ADHD) and controls using a rapid serial visual presentation (RSVP) task in which two letters (T1 and T2) were presented in close temporal proximity among distractors (attentional blink [AB]). Thirty children aged between 9 and 13 years (12 with ADHD combined type and 18 controls) took part in the study. Both groups performed two kinds of RSVP task. In the single task, participants simply had to identify a target letter (T1), whereas in the dual task, they had to identify a target letter (T1) and a probe letter (T2). The ADHD and control groups were equivalent in their single-task performance. However, in the dual-task condition, there were significant between-group differences in the rate of detection of the probe letter (T2) at lag + 1 and lag + 4. The ADHD group exhibited a larger overall AB compared with controls. Our findings provide support for a link between ADHD and attentional blink.

The Role of Task Understanding on Younger and Older Adults' Performance.

PubMed

Frank, David J; Touron, Dayna R

2016-12-16

Age-related performance decrements have been linked to inferior strategic choices. Strategy selection models argue that accurate task representations are necessary for choosing appropriate strategies. But no studies to date have compared task representations in younger and older adults. Metacognition research suggests age-related deficits in updating and utilizing strategy knowledge, but other research suggests age-related sparing when information can be consolidated into a coherent mental model. Study 1 validated the use of concept mapping as a tool for measuring task representation accuracy. Study 2 measured task representations before and after a complex strategic task to test for age-related decrements in task representation formation and updating. Task representation accuracy and task performance were equivalent across age groups. Better task representations were related to better performance. However, task representation scores remained fairly stable over the task with minimal evidence of updating. Our findings mirror those in the mental model literature suggesting age-related sparing of strategy use when information can be integrated into a coherent mental model. Future research should manipulate the presence of a unifying context to better evaluate this hypothesis. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Force-stabilizing synergies in motor tasks involving two actors

PubMed Central

Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M.; Latash, Mark L.

2015-01-01

We investigated the ability of two persons to produce force-stabilizing synergies in accurate multi-finger force production tasks under visual feedback on the total force only. The subjects produced a time profile of total force (the sum of two hand forces in one-person tasks and the sum of two subject forces in two-person tasks) consisting of a ramp-up, steady-state, and ramp-down segments; the steady-state segment was interrupted in the middle by a quick force pulse. Analyses of the structure of inter-trial finger force variance, motor equivalence, anticipatory synergy adjustments (ASAs), and the unintentional drift of the sharing pattern were performed. The two-person performance was characterized by a dramatically higher amount of inter-trial variance that did not affect total force, higher finger force deviations that did not affect total force (motor equivalent deviations), shorter ASAs, and larger drift of the sharing pattern. The rate of sharing pattern drift correlated with the initial disparity between the forces produced by the two persons (or two hands). The drift accelerated following the quick force pulse. Our observations show that sensory information on the task-specific performance variable is sufficient for the organization of performance-stabilizing synergies. They suggest, however, that two actors are less likely to follow a single optimization criterion as compared to a single performer. The presence of ASAs in the two-person condition might reflect fidgeting by one or both of the subjects. We discuss the characteristics of the drift in the sharing pattern as reflections of different characteristic times of motion within the sub-spaces that affect and do not affect salient performance variables. PMID:26105756

Force-stabilizing synergies in motor tasks involving two actors.

PubMed

Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M; Latash, Mark L

2015-10-01

We investigated the ability of two persons to produce force-stabilizing synergies in accurate multi-finger force production tasks under visual feedback on the total force only. The subjects produced a time profile of total force (the sum of two hand forces in one-person tasks and the sum of two subject forces in two-person tasks) consisting of a ramp-up, steady-state, and ramp-down segments; the steady-state segment was interrupted in the middle by a quick force pulse. Analyses of the structure of inter-trial finger force variance, motor equivalence, anticipatory synergy adjustments (ASAs), and the unintentional drift of the sharing pattern were performed. The two-person performance was characterized by a dramatically higher amount of inter-trial variance that did not affect total force, higher finger force deviations that did not affect total force (motor equivalent deviations), shorter ASAs, and larger drift of the sharing pattern. The rate of sharing pattern drift correlated with the initial disparity between the forces produced by the two persons (or two hands). The drift accelerated following the quick force pulse. Our observations show that sensory information on the task-specific performance variable is sufficient for the organization of performance-stabilizing synergies. They suggest, however, that two actors are less likely to follow a single optimization criterion as compared to a single performer. The presence of ASAs in the two-person condition might reflect fidgeting by one or both of the subjects. We discuss the characteristics of the drift in the sharing pattern as reflections of different characteristic times of motion within the subspaces that affect and do not affect salient performance variables.

Altered frontocortical, cerebellar, and basal ganglia activity in adjuvant-treated breast cancer survivors 5-10 years after chemotherapy.

PubMed

Silverman, Daniel H S; Dy, Christine J; Castellon, Steven A; Lai, Jasmine; Pio, Betty S; Abraham, Laura; Waddell, Kari; Petersen, Laura; Phelps, Michael E; Ganz, Patricia A

2007-07-01

To explore the relationship of regional cerebral blood flow and metabolism with cognitive function and past exposure to chemotherapy for breast cancer. Subjects treated for breast cancer with adjuvant chemotherapy remotely (5-10 years previously) were studied with neuropsychologic testing and positron emission tomography (PET), and were compared with control subjects who had never received chemotherapy. [O-15] water PET scans was acquired during performance of control and memory-related tasks to evaluate cognition-related cerebral blood flow, and [F-18] fluorodeoxyglucose (FDG) PET scans were acquired to evaluate resting cerebral metabolism. PET scans were analyzed by statistical parametric mapping and region of interest methods of analysis. During performance of a short-term recall task, modulation of cerebral blood flow in specific regions of frontal cortex and cerebellum was significantly altered in chemotherapy-treated subjects. Cerebral activation in chemotherapy-treated subjects differed most significantly from untreated subjects in inferior frontal gyrus, and resting metabolism in this area correlated with performance on a short-term memory task previously found to be particularly impaired in chemotherapy-treated subjects. In examining drug-class specific effects, metabolism of the basal ganglia was significantly decreased in tamoxifen + chemotherapy-treated patients compared with chemotherapy-only breast cancer subjects or with subjects who had not received chemotherapy, while chemotherapy alone was not associated with decreased basal ganglia activity relative to untreated subjects. Specific alterations in activity of frontal cortex, cerebellum, and basal ganglia in breast cancer survivors were documented by functional neuroimaging 5-10 years after completion of chemotherapy.

Agreement and Diagnostic Performance of FITNESSGRAM®, International Obesity Task Force, and Hungarian National BMI Standards

ERIC Educational Resources Information Center

Laurson, Kelly R.; Welk, Gregory J.; Marton, Orsolya; Kaj, Mónika; Csányi, Tamás

2015-01-01

Purpose: This study examined agreement between all 3 standards (as well as relative diagnostic associations with metabolic syndrome) using a representative sample of youth from the Hungarian National Youth Fitness Study. Method: Body mass index (BMI) was assessed in a field sample of 2,352 adolescents (ages 10-18.5 years) and metabolic syndrome…

A drop in performance on a fluid intelligence test due to instructed-rule mindset.

PubMed

ErEl, Hadas; Meiran, Nachshon

2017-09-01

A 'mindset' is a configuration of processing resources that are made available for the task at hand as well as their suitable tuning for carrying it out. Of special interest, remote-relation abstract mindsets are introduced by activities sharing only general control processes with the task. To test the effect of a remote-relation mindset on performance on a Fluid Intelligence test (Raven's Advanced Progressive Matrices, RAPM), we induced a mindset associated with little usage of executive processing by requiring participants to execute a well-defined classification rule 12 times, a manipulation known from previous work to drastically impair rule-generation performance and associated cognitive processes. In Experiment 1, this manipulation led to a drop in RAPM performance equivalent to 10.1 IQ points. No drop was observed in a General Knowledge task. In Experiment 2, a similar drop in RAPM performance was observed (equivalent to 7.9 and 9.2 IQ points) regardless if participants were pre-informed about the upcoming RAPM test. These results indicate strong (most likely, transient) adverse effects of a remote-relation mindset on test performance. They imply that although the trait of Fluid Intelligence has probably not changed, mindsets can severely distort estimates of this trait.

The eMouveRecherche application competes with research devices to evaluate energy expenditure, physical activity and still time in free-living conditions.

PubMed

Guidoux, Romain; Duclos, Martine; Fleury, Gérard; Lacomme, Philippe; Lamaudière, Nicolas; Saboul, Damien; Ren, Libo; Rousset, Sylvie

2017-05-01

The proliferation of smartphones is creating new opportunities to monitor and interact with human subjects in free-living conditions since smartphones are familiar to large segments of the population and facilitate data collection, transmission and analysis. From accelerometry data collected by smartphones, the present work aims to estimate time spent in different activity categories and the energy expenditure in free-living conditions. Our research encompasses the definition of an energy-saving function (Pred EE ) considering four physical categories of activities (still, light, moderate and vigorous), their duration and metabolic cost (MET). To create an efficient discrimination function, the method consists of classifying accelerometry-transformed signals into categories and of associating each category with corresponding Metabolic Equivalent Tasks. The performance of the Pred EE function was compared with two previously published functions (f(η,d)aedes,f(η,d)nrjsi), and with two dedicated sensors (Armband® and Actiheart®) in free-living conditions over a 12-h monitoring period using 30 volunteers. Compared to the two previous functions, Pred EE was the only one able to provide estimations of time spent in each activity category. In relative value, all the activity categories were evaluated similarly to those given by Armband®. Compared to Actiheart®, the function underestimated still activities by 10.1% and overestimated light- and moderate-intensity activities by 7.9% and 4.2%, respectively. The total energy expenditure error produced by Pred EE compared to Armband® was lower than those given by the two previous functions (5.7% vs. 14.1% and 17.0%). Pred EE provides the user with an accurate physical activity feedback which should help self-monitoring in free-living conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

pacce: Perl algorithm to compute continuum and equivalent widths

NASA Astrophysics Data System (ADS)

Riffel, Rogério; Borges Vale, Tibério

2011-08-01

We present Perl Algorithm to Compute continuum and Equivalent Widths ( pacce). We describe the methods used in the computations and the requirements for its usage. We compare the measurements made with pacce and "manual" ones made using iraf splot task. These tests show that for synthetic simple stellar population (SSP) models the equivalent widths strengths are very similar (differences ≲0.2 Å) for both measurements. In real stellar spectra, the correlation between both values is still very good, but with differences of up to 0.5 Å. pacce is also able to determine mean continuum and continuum at line center values, which are helpful in stellar population studies. In addition, it is also able to compute the uncertainties in the equivalent widths using photon statistics. The code is made available for the community through the web at http://www.if.ufrgs.br/~riffel/software.html .

LLNL Partners with IBM on Brain-Like Computing Chip

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

Van Essen, Brian

Lawrence Livermore National Laboratory (LLNL) will receive a first-of-a-kind brain-inspired supercomputing platform for deep learning developed by IBM Research. Based on a breakthrough neurosynaptic computer chip called IBM TrueNorth, the scalable platform will process the equivalent of 16 million neurons and 4 billion synapses and consume the energy equivalent of a hearing aid battery – a mere 2.5 watts of power. The brain-like, neural network design of the IBM Neuromorphic System is able to infer complex cognitive tasks such as pattern recognition and integrated sensory processing far more efficiently than conventional chips.

LLNL Partners with IBM on Brain-Like Computing Chip

ScienceCinema

Van Essen, Brian

2018-06-25

Lawrence Livermore National Laboratory (LLNL) will receive a first-of-a-kind brain-inspired supercomputing platform for deep learning developed by IBM Research. Based on a breakthrough neurosynaptic computer chip called IBM TrueNorth, the scalable platform will process the equivalent of 16 million neurons and 4 billion synapses and consume the energy equivalent of a hearing aid battery – a mere 2.5 watts of power. The brain-like, neural network design of the IBM Neuromorphic System is able to infer complex cognitive tasks such as pattern recognition and integrated sensory processing far more efficiently than conventional chips.

Glucose and lactate are equally effective in energizing activity-dependent synaptic vesicle turnover in purified cortical neurons.

PubMed

Morgenthaler, F D; Kraftsik, R; Catsicas, S; Magistretti, P J; Chatton, J-Y

2006-08-11

This study examines the role of glucose and lactate as energy substrates to sustain synaptic vesicle cycling. Synaptic vesicle turnover was assessed in a quantitative manner by fluorescence microscopy in primary cultures of mouse cortical neurons. An electrode-equipped perfusion chamber was used to stimulate cells both by electrical field and potassium depolarization during image acquisition. An image analysis procedure was elaborated to select in an unbiased manner synaptic boutons loaded with the fluorescent dye N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide (FM1-43). Whereas a minority of the sites fully released their dye content following electrical stimulation, others needed subsequent K(+) depolarization to achieve full release. This functional heterogeneity was not significantly altered by the nature of metabolic substrates. Repetitive stimulation sequences of FM1-43 uptake and release were then performed in the absence of any metabolic substrate and showed that the number of active sites dramatically decreased after the first cycle of loading/unloading. The presence of 1 mM glucose or lactate was sufficient to sustain synaptic vesicle cycling under these conditions. Moreover, both substrates were equivalent for recovery of function after a phase of decreased metabolic substrate availability. Thus, lactate appears to be equivalent to glucose for sustaining synaptic vesicle turnover in cultured cortical neurons during activity.

Mitochondrial energy deficiency leads to hyperproliferation of skeletal muscle mitochondria and enhanced insulin sensitivity.

PubMed

Morrow, Ryan M; Picard, Martin; Derbeneva, Olga; Leipzig, Jeremy; McManus, Meagan J; Gouspillou, Gilles; Barbat-Artigas, Sébastien; Dos Santos, Carlos; Hepple, Russell T; Murdock, Deborah G; Wallace, Douglas C

2017-03-07

Diabetes is associated with impaired glucose metabolism in the presence of excess insulin. Glucose and fatty acids provide reducing equivalents to mitochondria to generate energy, and studies have reported mitochondrial dysfunction in type II diabetes patients. If mitochondrial dysfunction can cause diabetes, then we hypothesized that increased mitochondrial metabolism should render animals resistant to diabetes. This was confirmed in mice in which the heart-muscle-brain adenine nucleotide translocator isoform 1 (ANT1) was inactivated. ANT1-deficient animals are insulin-hypersensitive, glucose-tolerant, and resistant to high fat diet (HFD)-induced toxicity. In ANT1-deficient skeletal muscle, mitochondrial gene expression is induced in association with the hyperproliferation of mitochondria. The ANT1-deficient muscle mitochondria produce excess reactive oxygen species (ROS) and are partially uncoupled. Hence, the muscle respiration under nonphosphorylating conditions is increased. Muscle transcriptome analysis revealed the induction of mitochondrial biogenesis, down-regulation of diabetes-related genes, and increased expression of the genes encoding the myokines FGF21 and GDF15. However, FGF21 was not elevated in serum, and FGF21 and UCP1 mRNAs were not induced in liver or brown adipose tissue (BAT). Hence, increased oxidation of dietary-reducing equivalents by elevated muscle mitochondrial respiration appears to be the mechanism by which ANT1-deficient mice prevent diabetes, demonstrating that the rate of mitochondrial oxidation of calories is important in the etiology of metabolic disease.

Brain imaging study of the acute effects of Delta9-tetrahydrocannabinol (THC) on attention and motor coordination in regular users of marijuana.

PubMed

Weinstein, Aviv; Brickner, Orit; Lerman, Hedva; Greemland, Mazal; Bloch, Miki; Lester, Hava; Chisin, Roland; Mechoulam, Raphael; Bar-Hamburger, Rachel; Freedman, Nanette; Even-Sapir, Einat

2008-01-01

Twelve regular users of marijuana underwent two positron emission tomography (PET) scans using [18F] Fluorodeoxyglucose (FDG), one while subject to the effects of 17 mg THC, the other without THC. In both sessions, a virtual reality maze task was performed during the FDG uptake period. When subject to the effects of 17 mg THC, regular marijuana smokers hit the walls more often on the virtual maze task than without THC. Compared to results without THC, 17 mg THC increased brain metabolism during task performance in areas that are associated with motor coordination and attention in the middle and medial frontal cortices and anterior cingulate, and reduced metabolism in areas that are related to visual integration of motion in the occipital lobes. These findings suggest that in regular marijuana users, the immediate effects of marijuana may impact on cognitive-motor skills and brain mechanisms that modulate coordinated movement and driving.

Stability of steady hand force production explored across spaces and methods of analysis.

PubMed

de Freitas, Paulo B; Freitas, Sandra M S F; Lewis, Mechelle M; Huang, Xuemei; Latash, Mark L

2018-06-01

We used the framework of the uncontrolled manifold (UCM) hypothesis and explored the reliability of several outcome variables across different spaces of analysis during a very simple four-finger accurate force production task. Fourteen healthy, young adults performed the accurate force production task with each hand on 3 days. Small spatial finger perturbations were generated by the "inverse piano" device three times per trial (lifting the fingers 1 cm/0.5 s and lowering them). The data were analyzed using the following main methods: (1) computation of indices of the structure of inter-trial variance and motor equivalence in the space of finger forces and finger modes, and (2) analysis of referent coordinates and apparent stiffness values for the hand. Maximal voluntary force and the index of enslaving (unintentional finger force production) showed good to excellent reliability. Strong synergies stabilizing total force were reflected in both structure of variance and motor equivalence indices. Variance within the UCM and the index of motor equivalent motion dropped over the trial duration and showed good to excellent reliability. Variance orthogonal to the UCM and the index of non-motor equivalent motion dropped over the 3 days and showed poor to moderate reliability. Referent coordinate and apparent stiffness indices co-varied strongly and both showed good reliability. In contrast, the computed index of force stabilization showed poor reliability. The findings are interpreted within the scheme of neural control with referent coordinates involving the hierarchy of two basic commands, the r-command and c-command. The data suggest natural drifts in the finger force space, particularly within the UCM. We interpret these drifts as reflections of a trade-off between stability and optimization of action. The implications of these findings for the UCM framework and future clinical applications are explored in the discussion. Indices of the structure of variance and motor equivalence show good reliability and can be recommended for applied studies.

Advanced Lockouts: Reengineering Safety Programs for Efficiency.

PubMed

Michalscheck, Jimi

2015-08-01

Remember one golden rule when engineering out lockout/tagout: No additional risk can be introduced to the employees by using alternative procedures. If you can design alternative procedures and an overall alternative program to ensure equivalent protection for specific tasks...the sky is the limit to enhancing productivity.

NEURODEVELOPMENTAL TOXICITY AND METABOLISM OF THE FLAME RETARDANT, TRIS (1,3-DICHLORO-2-PROPYL) PHOSPHATE

EPA Science Inventory

In the PC12 cell studies, it was found that exposure to an equimolar concentration of TDCPP resulted in deficits equivalent to or greater than that of CPF on measures of cellular replication and cell number, without affecting cell viability. TDCPP also altered the pattern o...

Prediction of Energy Expenditure from Wrist Accelerometry in People with and without Down Syndrome

ERIC Educational Resources Information Center

Agiovlasitis, Stamatis; Motl, Robert W.; Foley, John T.; Fernhall, Bo

2012-01-01

This study examined the relationship between energy expenditure and wrist accelerometer output during walking in persons with and without Down syndrome (DS). Energy expenditure in metabolic equivalent units (METs) and activity-count rate were respectively measured with portable spirometry and a uniaxial wrist accelerometer in 17 persons with DS…

All framing effects are not created equal: Low convergent validity between two classic measurements of framing

PubMed Central

Zhen, Shanshan; Yu, Rongjun

2016-01-01

Human risk-taking attitudes can be influenced by two logically equivalent but descriptively different frames, termed the framing effect. The classic hypothetical vignette-based task (Asian disease problem) and a recently developed reward-based gambling task have been widely used to assess individual differences in the framing effect. Previous studies treat framing bias as a stable trait that has genetic basis. However, these two paradigms differ in terms of task domain (loss vs. gain) and task context (vignette-based vs. reward-based) and the convergent validity of these measurements remains unknown. Here, we developed a vignette-based task and a gambling task in both gain and loss domains and tested correlations of the framing effect among these tasks in 159 young adults. Our results revealed no significant correlation between the vignette-based task in the loss domain and the gambling task in the gain domain, indicating low convergent validity. The current findings raise the question of how to measure the framing effect precisely, especially in individual difference studies using large samples and expensive neuroscience methods. Our results suggest that the framing effect is influenced by both task domain and task context and future research should be cautious about the operationalization of the framing effect. PMID:27436680

All framing effects are not created equal: Low convergent validity between two classic measurements of framing.

PubMed

Zhen, Shanshan; Yu, Rongjun

2016-07-20

Human risk-taking attitudes can be influenced by two logically equivalent but descriptively different frames, termed the framing effect. The classic hypothetical vignette-based task (Asian disease problem) and a recently developed reward-based gambling task have been widely used to assess individual differences in the framing effect. Previous studies treat framing bias as a stable trait that has genetic basis. However, these two paradigms differ in terms of task domain (loss vs. gain) and task context (vignette-based vs. reward-based) and the convergent validity of these measurements remains unknown. Here, we developed a vignette-based task and a gambling task in both gain and loss domains and tested correlations of the framing effect among these tasks in 159 young adults. Our results revealed no significant correlation between the vignette-based task in the loss domain and the gambling task in the gain domain, indicating low convergent validity. The current findings raise the question of how to measure the framing effect precisely, especially in individual difference studies using large samples and expensive neuroscience methods. Our results suggest that the framing effect is influenced by both task domain and task context and future research should be cautious about the operationalization of the framing effect.

Acid azo dye remediation in anoxic-aerobic-anoxic microenvironment under periodic discontinuous batch operation: bio-electro kinetics and microbial inventory.

PubMed

Venkata Mohan, S; Suresh Babu, P; Naresh, K; Velvizhi, G; Madamwar, Datta

2012-09-01

Functional behavior of anoxic-aerobic-anoxic microenvironment on azo dye (C.I. Acid black 10B) degradation was evaluated in a periodic discontinuous batch mode operation for 26 cycles. Dye removal efficiency and azo-reductase activity (30.50 ± 1 U) increased with each feeding event until 13th cycle and further stabilized. Dehydrogenase activity also increased gradually and stabilized (2.0 ± 0.2 μg/ml) indicating the stable proton shuttling between metabolic intermediates providing higher number of reducing equivalents towards dye degradation. Voltammetric profiles showed drop in redox catalytic currents during stabilized phase also supports the consumption of reducing equivalents towards dye removal. Change in Tafel slopes, polarization resistance and other bioprocess parameters correlated well with the observed dye removal and biocatalyst behavior. Microbial community analysis documented the involvement of specific organism pertaining to aerobic and facultative functions with heterotrophic and autotrophic metabolism. Integrating anoxic microenvironment with aerobic operation might have facilitated effective dye mineralization due to the possibility of combining redox functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Inference of beliefs and emotions in patients with Alzheimer's disease.

PubMed

Zaitchik, Deborah; Koff, Elissa; Brownell, Hiram; Winner, Ellen; Albert, Marilyn

2006-01-01

The present study compared 20 patients with mild to moderate Alzheimer's disease with 20 older controls (ages 69-94 years) on their ability to make inferences about emotions and beliefs in others. Six tasks tested their ability to make 1st-order and 2nd-order inferences as well as to offer explanations and moral evaluations of human action by appeal to emotions and beliefs. Results showed that the ability to infer emotions and beliefs in 1st-order tasks remains largely intact in patients with mild to moderate Alzheimer's. Patients were able to use mental states in the prediction, explanation, and moral evaluation of behavior. Impairment on 2nd-order tasks involving inference of mental states was equivalent to impairment on control tasks, suggesting that patients' difficulty is secondary to their cognitive impairments. ((c) 2006 APA, all rights reserved).

Silicon material task - Low cost solar array project /JPL/DOE/

NASA Technical Reports Server (NTRS)

Lutwack, R.

1979-01-01

The paper describes the silicon material task of the low-cost solar array project, which has the objective of establishing a silicon production capability equivalent to 500 mW per year at a price less than 10 dollars/kg (1975 dollars) in 1986. The task program is divided into four phases: technical feasibility, scale-up studies (the present phase), experimental process system development units, and implementation of large-scale production plants, and it involves the development of processes for two groups of materials, that is, semiconductor grade and solar cell grade. In addition, the effects of impurities on solar cell performance are being investigated. Attention is given to problem areas of the task program, such as environmental protection, material compatibility between the reacting chemicals and materials of construction of the equipment, and waste disposal.

Starting points and pathways in Aboriginal students' learning of number: recognising different world views

NASA Astrophysics Data System (ADS)

Treacy, Kaye; Frid, Sandra; Jacob, Lorraine

2015-09-01

This research was designed to investigate the conceptualisations and thinking strategies Indigenous Australian students use in counting tasks. Eighteen Aboriginal students, in years 1 to 11 at a remote community school, were interviewed using standard counting tasks and a `counting' task that involved fetching `maku' (witchetty grubs) to have enough to give a maku to each person in a picture. The tasks were developed with, and the interviews conducted by, an Aboriginal research assistant, to ensure appropriate cultural and language contexts. A main finding was that most of the students did not see the need to use counting to make equivalent sets, even though they were able to demonstrate standard counting skills. The findings highlight a need to further examine the world views, orientations and related mathematical concepts and processes that Indigenous students bring to school.

Integration of local motion is normal in amblyopia

NASA Astrophysics Data System (ADS)

Hess, Robert F.; Mansouri, Behzad; Dakin, Steven C.; Allen, Harriet A.

2006-05-01

We investigate the global integration of local motion direction signals in amblyopia, in a task where performance is equated between normal and amblyopic eyes at the single element level. We use an equivalent noise model to derive the parameters of internal noise and number of samples, both of which we show are normal in amblyopia for this task. This result is in apparent conflict with a previous study in amblyopes showing that global motion processing is defective in global coherence tasks [Vision Res. 43, 729 (2003)]. A similar discrepancy between the normalcy of signal integration [Vision Res. 44, 2955 (2004)] and anomalous global coherence form processing has also been reported [Vision Res. 45, 449 (2005)]. We suggest that these discrepancies for form and motion processing in amblyopia point to a selective problem in separating signal from noise in the typical global coherence task.

Characterizing the normative profile of 18F-FDG PET brain imaging: sex difference, aging effect, and cognitive reserve.

PubMed

Yoshizawa, Hiroshi; Gazes, Yunglin; Stern, Yaakov; Miyata, Yoko; Uchiyama, Shinichiro

2014-01-30

The aim of this study was to investigate findings of positron emission tomography with 18F-fluorodeoxyglucose (18F-FDG PET) in normal subjects to clarify the effects of sex differences, aging, and cognitive reserve on cerebral glucose metabolism. Participants comprised 123 normal adults who underwent 18F-FDG PET and a neuropsychological battery. We used statistical parametric mapping (SPM8) to investigate sex differences, and aging effects. The effects of cognitive reserve on 18F-FDG uptake were investigated using years of education as a proxy. Finally, we studied the effect of cognitive reserve on the recruitment of glucose metabolism in a memory task by dichotomizing the data according to educational level. Our results showed that the overall cerebral glucose metabolism in females was higher than that in males, whereas male participants had higher glucose metabolism in the bilateral inferior temporal gyri and cerebellum than females. Age-related hypometabolism was found in anterior regions, including the anterior cingulate gyrus. These areas are part of the attentional system, which may decline with aging even in healthy elderly individuals. Highly educated subjects revealed focal hypermetabolism in the right hemisphere and lower recruitment of glucose metabolism in memory tasks. This phenomenon is likely a candidate for a neural substrate of cognitive reserve. © 2013 Published by Elsevier Ireland Ltd.

An engineered microbial platform for direct biofuel production from brown macroalgae.

PubMed

Wargacki, Adam J; Leonard, Effendi; Win, Maung Nyan; Regitsky, Drew D; Santos, Christine Nicole S; Kim, Peter B; Cooper, Susan R; Raisner, Ryan M; Herman, Asael; Sivitz, Alicia B; Lakshmanaswamy, Arun; Kashiyama, Yuki; Baker, David; Yoshikuni, Yasuo

2012-01-20

Prospecting macroalgae (seaweeds) as feedstocks for bioconversion into biofuels and commodity chemical compounds is limited primarily by the availability of tractable microorganisms that can metabolize alginate polysaccharides. Here, we present the discovery of a 36-kilo-base pair DNA fragment from Vibrio splendidus encoding enzymes for alginate transport and metabolism. The genomic integration of this ensemble, together with an engineered system for extracellular alginate depolymerization, generated a microbial platform that can simultaneously degrade, uptake, and metabolize alginate. When further engineered for ethanol synthesis, this platform enables bioethanol production directly from macroalgae via a consolidated process, achieving a titer of 4.7% volume/volume and a yield of 0.281 weight ethanol/weight dry macroalgae (equivalent to ~80% of the maximum theoretical yield from the sugar composition in macroalgae).

Basic Color Terms (BCTs) and Categories (BCCs) in Three Dialects of the Spanish Language: Interaction Between Cultural and Universal Factors.

PubMed

Lillo, Julio; González-Perilli, Fernando; Prado-León, Lilia; Melnikova, Anna; Álvaro, Leticia; Collado, José A; Moreira, Humberto

2018-01-01

Two experiments were performed to identify and compare the Basic Color Terms (BCTs) and the Basic Color Categories (BCCs) included in three dialects (Castilian, Mexican, and Uruguayan) of the Spanish language. Monolexemic Elicited lists were used in the first experiment to identify the BCTs of each dialect. Eleven BCTs appeared for the Spanish and the Mexican, and twelve did so for the Uruguayan. The six primary BCTs ( rojo "red," verde "green," amarillo "yellow," azul "blue," negro "black," and blanco "white") appeared in the three dialects. This occurred for only three derived BCTs ( gris "gray," naranja "orange," and rosa "pink") but not for the other five derived BCTs ( celeste "sky blue," marrón "brown," café "brown," morado "purple," and violeta "purple"). Color transitions were used in the second experiment for two different tasks. Extremes naming task was used to determine the relation between two different dialects' BCTs: equality, equivalence or difference. The results provided the first evidence for marrón "brown" and café "brown" being equivalent terms for the same BCC (brown in English) as is the case of morado "purple" and violeta "purple." Uruguayan celeste "sky blue" had no equivalent BCT in the other two dialects. Boundary delimitation task required the selection of the color in the boundary between two categories. The task was used to reasonably estimate the volume occupied by each BCC in the color space considering its chromatic area and lightness range. Excluding sky blue ( celeste "sky blue") and blue ( azul "blue"), the other BCCs color volumes were similar across the three dialects. Uruguayan sky blue and blue volumes conjointly occupied the portion of the color space corresponding to the Castilian and Mexican blue BCC. The fact that the BCT celeste "sky blue" only appeared in Uruguayan very probably derived from specific cultural factors (the use of the color in the flags and the arrival of an important number of Italian immigrants). Nevertheless, these cultural factors seem to nurture from a perceptive structuring of the color space, which nature is universal, as the boundaries of this category can be delimited from the responses of Spanish and Mexican participants.

Hydration Effects on Human Physiology and Exercise-Heat Performance

DTIC Science & Technology

1989-11-01

lifter and marathon runner are all dissimilar. Some of these activities require primarily anaerobic metabolism and skeletal muscle strength, whereas...require aerobic metabolism and that are prolonged will1 more likely be adversely influenced by hypohydration than exercilse tasks that require anaerobic ...hypohydration on muscular strength and endurance as well as anaerobic performance (114). Table 4. Summary of studies investigating the influence of

A Semi-Automatic Alignment Method for Math Educational Standards Using the MP (Materialization Pattern) Model

ERIC Educational Resources Information Center

Choi, Namyoun

2010-01-01

Educational standards alignment, which matches similar or equivalent concepts of educational standards, is a necessary task for educational resource discovery and retrieval. Automated or semi-automated alignment systems for educational standards have been recently available. However, existing systems frequently result in inconsistency in…

48 CFR 752.242-70 - Periodic progress reports.

Code of Federal Regulations, 2010 CFR

2010-10-01

... interpreted as “task order” or “delivery order” when this clause is used in an indefinite-delivery contract... may be used by USAID personnel or their authorized representatives when evaluating the contractor's... contracting officer may withhold from payment an amount not to exceed US$25,000 (or local currency equivalent...

Advanced bridge safety initiative, task 3 : slab bridge load rating using AASHTO methodology and finite element analysis - an analysis of 20 bridges.

DOT National Transportation Integrated Search

2011-12-01

Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

Evolution of gene expression in fire ants: the effects of developmental stage, caste, and species

USDA-ARS?s Scientific Manuscript database

Ants provide remarkable examples of equivalent genotypes developing into divergent and discrete phenotypes. Diploid eggs can develop either into queens, which specialize in reproduction, or workers, which participate in cooperative tasks such as building the nest, collecting food, and rearing the yo...

The Role of Noncriterial Recollection in Estimating Recollection and Familiarity

ERIC Educational Resources Information Center

Parks, Colleen M.

2007-01-01

Noncriterial recollection (ncR) is recollection of details that are irrelevant to task demands. It has been shown to elevate familiarity estimates and to be functionally equivalent to familiarity in the process dissociation procedure [Yonelinas, A. P., & Jacoby, L. L. (1996). Noncriterial recollection: Familiarity as automatic, irrelevant…

Brain-Behavior Relationships in Reading Acquisition Are Modulated by Socioeconomic Factors

ERIC Educational Resources Information Center

Noble, Kimberly G.; Wolmetz, Michael E.; Ochs, Lisa G.; Farah, Martha J.; McCandliss, Bruce D.

2006-01-01

Functional neuroimaging may provide insights into the achievement gap in reading skill commonly observed across socioeconomic status (SES). Brain activation during reading tasks is known to be associated with individual differences in children's phonological language skills. By selecting children of equivalent phonological skill, yet diverse…

Revisit Pattern Blocks to Develop Rational Number Sense

ERIC Educational Resources Information Center

Champion, Joe; Wheeler, Ann

2014-01-01

Pattern blocks are inexpensive wooden, foam, or plastic manipulatives developed in the 1960s to help students build an understanding of shapes, proportions, equivalence, and fractions (EDC 1968). The colorful collection of basic shapes in classic pattern block kits affords opportunities for amazing puzzle-like problem-solving tasks and for…

Cognitive Processes Embedded in Self-Explanations of Solving Technical Problems: Implications for Training

ERIC Educational Resources Information Center

Maughan, George R.

2007-01-01

This qualitative research examines the cognitive processes embedded in self-explanations of automobile and motorcycle service technicians performing troubleshooting tasks and solving technical problems. In-depth interviews were conducted with twelve service technicians who have obtained the designation of "master technician" or equivalent within…

Advanced bridge safety initiative : recommended practices for live load testing of existing flat-slab concrete bridges - task 5.

DOT National Transportation Integrated Search

2012-12-01

Current AASHTO provisions for load rating flat-slab concrete bridges use the equivalent strip : width method, which is regarded as overly conservative compared to more advanced analysis : methods and field live load testing. It has been shown that li...

Advanced bridge safety initiative, task 1 : development of improved analytical load rating procedures for flat-slab concrete bridges - a thesis and guidelines.

DOT National Transportation Integrated Search

2010-01-01

Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

Subthalamic nucleus stimulation affects theory of mind network: a PET study in Parkinson's disease.

PubMed

Péron, Julie; Le Jeune, Florence; Haegelen, Claire; Dondaine, Thibaut; Drapier, Dominique; Sauleau, Paul; Reymann, Jean-Michel; Drapier, Sophie; Rouaud, Tiphaine; Millet, Bruno; Vérin, Marc

2010-03-29

There appears to be an overlap between the limbic system, which is modulated by subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD), and the brain network that mediates theory of mind (ToM). Accordingly, the aim of the present study was to investigate the effects of STN DBS on ToM of PD patients and to correlate ToM modifications with changes in glucose metabolism. To this end, we conducted (18)FDG-PET scans in 13 PD patients in pre- and post-STN DBS conditions and correlated changes in their glucose metabolism with modified performances on the Eyes test, a visual ToM task requiring them to describe thoughts or feelings conveyed by photographs of the eye region. Postoperative PD performances on this emotion recognition task were significantly worse than either preoperative PD performances or those of healthy controls (HC), whereas there was no significant difference between preoperative PD and HC. Conversely, PD patients in the postoperative condition performed within the normal range on the gender attribution task included in the Eyes test. As far as the metabolic results are concerned, there were correlations between decreased cerebral glucose metabolism and impaired ToM in several cortical areas: the bilateral cingulate gyrus (BA 31), right middle frontal gyrus (BA 8, 9 and 10), left middle frontal gyrus (BA 6), temporal lobe (fusiform gyrus, BA 20), bilateral parietal lobe (right BA 3 and right and left BA 7) and bilateral occipital lobe (BA 19). There were also correlations between increased cerebral glucose metabolism and impaired ToM in the left superior temporal gyrus (BA 22), left inferior frontal gyrus (BA 13 and BA 47) and right inferior frontal gyrus (BA 47). All these structures overlap with the brain network that mediates ToM. These results seem to confirm that STN DBS hinders the ability to infer the mental states of others and modulates a distributed network known to subtend ToM.

Precision Metabolic Engineering: the Design of Responsive, Selective, and Controllable Metabolic Systems

PubMed Central

McNerney, Monica P.; Watstein, Daniel M.; Styczynski, Mark P.

2015-01-01

Metabolic engineering is generally focused on static optimization of cells to maximize production of a desired product, though recently dynamic metabolic engineering has explored how metabolic programs can be varied over time to improve titer. However, these are not the only types of applications where metabolic engineering could make a significant impact. Here, we discuss a new conceptual framework, termed “precision metabolic engineering,” involving the design and engineering of systems that make different products in response to different signals. Rather than focusing on maximizing titer, these types of applications typically have three hallmarks: sensing signals that determine the desired metabolic target, completely directing metabolic flux in response to those signals, and producing sharp responses at specific signal thresholds. In this review, we will first discuss and provide examples of precision metabolic engineering. We will then discuss each of these hallmarks and identify which existing metabolic engineering methods can be applied to accomplish those tasks, as well as some of their shortcomings. Ultimately, precise control of metabolic systems has the potential to enable a host of new metabolic engineering and synthetic biology applications for any problem where flexibility of response to an external signal could be useful. PMID:26189665

BiKEGG: a COBRA toolbox extension for bridging the BiGG and KEGG databases.

PubMed

Jamialahmadi, Oveis; Motamedian, Ehsan; Hashemi-Najafabadi, Sameereh

2016-10-18

Development of an interface tool between the Biochemical, Genetic and Genomic (BiGG) and KEGG databases is necessary for simultaneous access to the features of both databases. For this purpose, we present the BiKEGG toolbox, an open source COBRA toolbox extension providing a set of functions to infer the reaction correspondences between the KEGG reaction identifiers and those in the BiGG knowledgebase using a combination of manual verification and computational methods. Inferred reaction correspondences using this approach are supported by evidence from the literature, which provides a higher number of reconciled reactions between these two databases compared to the MetaNetX and MetRxn databases. This set of equivalent reactions is then used to automatically superimpose the predicted fluxes using COBRA methods on classical KEGG pathway maps or to create a customized metabolic map based on the KEGG global metabolic pathway, and to find the corresponding reactions in BiGG based on the genome annotation of an organism in the KEGG database. Customized metabolic maps can be created for a set of pathways of interest, for the whole KEGG global map or exclusively for all pathways for which there exists at least one flux carrying reaction. This flexibility in visualization enables BiKEGG to indicate reaction directionality as well as to visualize the reaction fluxes for different static or dynamic conditions in an animated manner. BiKEGG allows the user to export (1) the output visualized metabolic maps to various standard image formats or save them as a video or animated GIF file, and (2) the equivalent reactions for an organism as an Excel spreadsheet.

International physical activity questionnaire overestimation is ameliorated by individual analysis of the scores.

PubMed

Bermúdez, Valmore J; Rojas, Joselyn J; Córdova, Evelyn B; Añez, Roberto; Toledo, Alexandra; Aguirre, Miguel A; Cano, Climaco; Arraiz, Nailet; Velasco, Manuel; López-Miranda, José

2013-01-01

Sedentarism is considered a risk factor for coronary heart disease and death from any cardiovascular disease. The International Physical Activity Questionnaire (IPAQ) assesses physical activity in metabolic equivalents, using 4 dimensions: occupation, transportation, household activities, and leisure-time physical activity. The purpose of this investigation was to assess physical activity levels in the patients enrolled in the Maracaibo City Metabolic Syndrome Prevalence Study, currently undertaken by the "Dr. Félix Gómez" Endocrine-Metabolic Research Center. Two thousand one hundred eight individuals were recruited and subjected to a standard Medical chart, Graffar scale, and IPAQ long form, applied by trained personnel. Description of the population was done using mean, SD, and coefficient of variation. IPAQ scores were analyzed as medians and distributed by percentiles. From the 2108 individuals, 46.9% were men and 53.1% were women. The most prevalent physical activity was high physical activity with 39.9%, followed by moderate physical activity with 36.9% and low physical activity with 23.2%. Medians for each IPAQ dominion were occupation with 0.00 (0.00-66.00), transportation with 165.00 (0.00-463.00), household activities with 772.50 (0.00-2520.00), and leisure time with 0.00 (0.00-594.00). Using leisure-time scores, a new reclassification was conducted, obtaining 1245 subjects with 0 metabolic equivalents in this dominion. From this new subsample, 43.6% had High physical activity, 56.95% had Moderate physical activity, and 91% had Low physical activity, demonstrating an important overestimation in the former sample results. IPAQ overestimates moderate and vigorous activity in the adult population of the Maracaibo Municipality. Overestimation is mainly located in the household- and gardening-related activity.

Do all inhibitions act alike? A study of go/no-go and stop-signal paradigms

PubMed Central

Takács, Ádám

2017-01-01

Response inhibition is frequently measured by the Go/no-go and Stop-signal tasks. These two are often used indiscriminately under the assumption that both measure similar inhibitory control abilities. However, accumulating evidence show differences in both tasks' modulations, raising the question of whether they tap into equivalent cognitive mechanisms. In the current study, a comparison of the performance in both tasks took place under the influence of negative stimuli, following the assumption that ''controlled inhibition'', as measured by Stop-signal, but not ''automatic inhibition'', as measured by Go/no-go, will be affected. 54 young adults performed a task in which negative pictures, neutral pictures or no-pictures preceded go trials, no-go trials, and stop-trials. While the exposure to negative pictures impaired performance on go trials and improved the inhibitory capacity in Stop-signal task, the inhibitory performance in Go/no-go task was generally unaffected. The results support the conceptualization of different mechanisms operated by both tasks, thus emphasizing the necessity to thoroughly fathom both inhibitory processes and identify their corresponding cognitive measures. Implications regarding the usage of cognitive tasks for strengthening inhibitory capacity among individuals struggling with inhibitory impairments are discussed. PMID:29065184

A smartphone-driven methodology for estimating physical activities and energy expenditure in free living conditions.

PubMed

Guidoux, Romain; Duclos, Martine; Fleury, Gérard; Lacomme, Philippe; Lamaudière, Nicolas; Manenq, Pierre-Henri; Paris, Ludivine; Ren, Libo; Rousset, Sylvie

2014-12-01

This paper introduces a function dedicated to the estimation of total energy expenditure (TEE) of daily activities based on data from accelerometers integrated into smartphones. The use of mass-market sensors such as accelerometers offers a promising solution for the general public due to the growing smartphone market over the last decade. The TEE estimation function quality was evaluated using data from intensive numerical experiments based, first, on 12 volunteers equipped with a smartphone and two research sensors (Armband and Actiheart) in controlled conditions (CC) and, then, on 30 other volunteers in free-living conditions (FLC). The TEE given by these two sensors in both conditions and estimated from the metabolic equivalent tasks (MET) in CC served as references during the creation and evaluation of the function. The TEE mean gap in absolute value between the function and the three references was 7.0%, 16.4% and 2.7% in CC, and 17.0% and 23.7% according to Armband and Actiheart, respectively, in FLC. This is the first step in the definition of a new feedback mechanism that promotes self-management and daily-efficiency evaluation of physical activity as part of an information system dedicated to the prevention of chronic diseases. Copyright © 2014 Elsevier Inc. All rights reserved.

The physical activity transition among adults in China: 1991-2011.

PubMed

Ng, S W; Howard, A-G; Wang, H J; Su, C; Zhang, B

2014-01-01

Previous studies have linked work, home production, travel activities and inactivity with weight and health outcomes. However, these focused on average physical activity (PA) over time rather than changes in PA and associated sociodemographic and economic factors and urbanicity. Using the 1991-2011 China Health and Nutrition Survey data, we estimated the metabolic equivalent of task hours per week for individuals in occupational, domestic, travel and active leisure domains and sedentary hours per week. We present the distributions among adult men and women (aged 18-60), and use quantile regression models to explore factors associated with these trends. Trend analyses on the distribution of PA show declines along the whole distribution of occupational PA for men and women and domestic PA for women in China. These patterns remain consistent after adjusting for individual- and household-level factors. Controlling for urbanicity mitigated the decrease in occupational PA, particularly for men, but not the decrease in domestic PA. Given China's rapid urbanization and its association with occupational PA declines and the strong time trend in domestic PA, there is a need to invest in interventions and policies that promote PA during leisure and travel times. © 2014 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of the International Association for the Study of Obesity.

The effect of individual education on patients' physical activity capacity after myocardial infarction.

PubMed

Uysal, Hilal; Ozcan, Şeyda

2015-02-01

The present study aims to determine the effects of individual education and counselling given to first-time myocardial infarction patients, including its effect on compliance with treatment. The sample comprised 90 patients, 45 in the intervention and 45 in the control group, selected by sequential sampling from first-time myocardial infarction patients. Data were collected between April and November 2008 by means of patient information form, International Physical Activity Questionnaire, 6 min walk test, Modified Borg Scale, Morisky Medication Adherence Scale and Canadian Cardiovascular Society Angina Grade Classification. In the intervention group more improvement was observed in comparison with the control group in terms of frequency of physical activity, body mass index and waist circumference. It was observed that the intervention group's metabolic equivalent of task values and 6 min walk test distance increased more in comparison with the control group 3 months after baseline, and there was a statistically significant difference. The results indicated that individual education and counselling provided to patients having experienced acute myocardial infarction increased functional capacity by providing patients with advice on how to lose weight and by improving compliance with treatment through physical activity behaviours (frequency and duration). © 2013 Wiley Publishing Asia Pty Ltd.

A rapid review to identify physical activity accrued while playing golf

PubMed Central

Luscombe, Jack; Murray, Andrew D; Jenkins, Evan; Archibald, Daryll

2017-01-01

Objective To identify physical activity (PA) accrued while playing golf and modifiers of PA accrued. Design A rapid review of primary research studies. Quality was assessed using the National Heart, Lung, and Blood Institute quality assessment tool for cohort and cross-sectional studies. Methods and outcomes The following databases were searched from 1900 to March 2017: SPORTDiscus, Web of Science, PsycINFO, MEDLINE, Google Scholar, Google Advanced Search, ProQuest, WHO International Clinical Trials Registry Platform. All primary research investigating golf or golfers with any of the following outcomes was included: metabolic equivalent of task, oxygen uptake, energy expenditure, heart rate, step count, distance covered, strength, flexibility, balance, sedentary behaviour. Results Phase one searching identified 4944 citations and phase two searching identified 170 citations. In total, 19 articles met inclusion criteria. Golf is primarily a moderate intensity PA, but may be low intensity depending on the playing population and various modifiers. Less PA is accrued by those who ride a golf cart compared with those walking the course. Conclusions Golf can be encouraged in order to attain PA recommendations. Further research is required into the relationship between golf and strength and flexibility PA recommendations and how modifiers affect PA accrued. PROSPERO registration number CRD42017058237. PMID:29187418

A church-based intervention to change attitudes about physical activity among Black adolescent girls: a feasibility study.

PubMed

Thompson, Wanda M; Berry, Diane; Hu, Jie

2013-05-01

To feasibility test a 12-week church-based physical activity intervention that was culturally sensitive, age- and gender specific directed at changing attitudes of Black adolescent girls' to be more physically active. A one-group pre- and posttest design was used. A convenience sample of Black adolescent girls between the age of 12-18 (n = 41). A 60-min 12-week church-based program that included interactive educational sessions followed by a high energy dance aerobics class was used. Data were collected on biophysical measures. Surveys were used to assess the following variables: attitudes, enjoyment, self-efficacy, intention, social and family support, and PA levels. Paired t-tests and repeated measures ANOVA revealed no significant changes in key variables. Positive changes were noted in the odds ratios for attitudes, self-efficacy, and intention. Body mass index, metabolic equivalent tasks, and fitness showed positive trends from pre to post intervention. Family support was significantly correlated with physical activity level (p < .01). The study showed that physical activity programs in Black churches aimed at Black adolescent girls are feasible. Participants evaluated the intervention very favorably. Family support may be a key factor in increasing physical activity levels in Black adolescent girls. © 2012 Wiley Periodicals, Inc.

Overcoming birth weight: can physical activity mitigate birth weight-related differences in adiposity?

PubMed

Boone-Heinonen, J; Markwardt, S; Fortmann, S P; Thornburg, K L

2016-06-01

Individuals born at low or high birth weight (BW) have elevated adiposity. The extent to which physical activity can mitigate this risk is unknown. The aim of this study was to determine if associations between BW and adiposity vary by self-reported moderate-to-vigorous physical activity (MVPA) among adolescents. We used data on adolescents in the National Health and Nutrition Examination Survey (1999-2006; 12-15 years; n = 4064). Using gender-stratified linear regression, we modelled body mass index (BMI) and waist circumference (WC) z-scores as a function of low, normal and high BW, MVPA (weekly Metabolic Equivalent of Task hours) and MVPA*BW cross-product terms, adjusting for sociodemographics, diet and, in WC models, BMI. Among girls with low MVPA, those born with high BW had greater BMI than normal BW; this difference diminished with greater MVPA (coefficient [95% confidence interval]: low MVPA: 0.72 [0.29, 1.14]; high MVPA: -0.04 [-0.48, 0.39]; P for interaction = 0.05). Among boys, MVPA did not modify the associations between BW and BMI. WC was unrelated to BW, regardless of MVPA. Findings suggest that effects of high BW in total adiposity can be more easily modified with MVPA in adolescent girls than in boys. © 2015 World Obesity.

Durations and domains of daily aerobic activity: evidence from the 2010 Canadian time-use survey.

PubMed

Millward, Hugh; Spinney J, E L; Scott, Darren

2014-07-01

This study employs national time-diary data to evaluate how much aerobic activity Canadians engage in on a daily basis, how that activity is apportioned by activity domain, and how subgroups within the population vary in their aerobic attainment. The study employs time-use data from the 2010 General Social Survey of Canada, for 15,390 respondents aged 15 and older. To estimate effort levels, the authors harmonized survey codes with those in the Compendium of Physical Activities. Aerobic activity was defined as moderate or vigorous effort at 3.5 Metabolic Equivalent of Task (MET) or higher. Among the 4 activity domains, aerobic participation is highest in leisure activities, followed by chores, paid work, and active transportation (AT). Only a minority (42%) of respondents recorded at least 20 mins/day of aerobic activity. Aerobic totals were particularly low for women and those in poor or fair health, and low for students, 15- to 24-year-olds, and those residing in Quebec, Ontario, and larger cities. The majority of Canadian adults are failing to meet recommended aerobic activity levels. However, there is considerable opportunity to increase aerobic participation for some groups, particularly women and young adults, especially in the leisure and AT domains.

A re-examination of the metabolic equivalent concept in individuals with coronary heart disease.

PubMed

Savage, Patrick D; Toth, Michael J; Ades, Philip A

2007-01-01

The metabolic equivalent (MET) is a commonly used method of quantifying the energy cost and intensity of physical activity. Recent studies have questioned the accuracy of the well-accepted value of a MET of 3.5 mL O2.kg(-1).min(-1). The goal of the present study was to compare the traditionally accepted value for 1 MET to direct measures of resting metabolic rate in a group of stable individuals with coronary heart disease (CHD). The primary cohort consisted of 109 (60 men and 49 women) subjects with documented coronary heart disease and a body mass index >or=25 kg/m2. Measurements included indirect calorimetry, body composition, and exercise capacity (peak oxygen uptake [VO2]). In a substudy of 17 (10 men, 7 women) normal weight subjects (body mass index <25 kg/m2), metabolic rate in the seated position was also measured. Mean resting value for 1 MET was a VO2 value of 2.58 +/- 0.4 mL O2.kg(-1).min(-1) for overweight subjects measured in the supine position and 2.84 +/- 0.59 mL O2.kg(-1).min(-1) for normal weight individuals measured in the seated position. Caloric expenditure value was 0.74 +/- 0.12 kcal.kg(-1).h(-1) rather than the expected value of 1 kcal.kg(-1).h(-1). Values were similar between men and women. Women on beta-blockers had a lower resting metabolic rate (2.47 +/- 0.27 vs. 2.71 +/- 0.38 mL O2.kg(-1).min(-1)) (P < .05) than women not on beta-blocker therapy, whereas there was no effect of beta-blockers in men. Findings confirm recent studies of otherwise healthy individuals and indicate that the average resting metabolic rate in subjects with coronary heart disease is 23% to 36% lower than the widely accepted value of 3.5 mL O2.kg(-1).min(-1). Results demonstrate the limitation of the convention of expressing energy expenditure in multiples of an assumed constant.

Does metabolic compensation explain the majority of less-than-expected weight loss in obese adults during a short-term severe diet and exercise intervention?

PubMed

Byrne, N M; Wood, R E; Schutz, Y; Hills, A P

2012-11-01

We investigated to what extent changes in metabolic rate and composition of weight loss explained the less-than-expected weight loss in obese men and women during a diet-plus-exercise intervention. In all, 16 obese men and women (41 ± 9 years; body mass index (BMI) 39 ± 6 kg m(-2)) were investigated in energy balance before, after and twice during a 12-week very-low-energy diet(565-650 kcal per day) plus exercise (aerobic plus resistance training) intervention. The relative energy deficit (EDef) from baseline requirements was severe (74%-87%). Body composition was measured by deuterium dilution and dual energy X-ray absorptiometry, and resting metabolic rate (RMR) was measured by indirect calorimetry. Fat mass (FM) and fat-free mass (FFM) were converted into energy equivalents using constants 9.45 kcal per g FM and 1.13 kcal per g FFM. Predicted weight loss was calculated from the EDef using the '7700 kcal kg(-1) rule'. Changes in weight (-18.6 ± 5.0 kg), FM (-15.5 ± 4.3 kg) and FFM (-3.1 ± 1.9 kg) did not differ between genders. Measured weight loss was on average 67% of the predicted value, but ranged from 39% to 94%. Relative EDef was correlated with the decrease in RMR (R=0.70, P<0.01), and the decrease in RMR correlated with the difference between actual and expected weight loss (R=0.51, P<0.01). Changes in metabolic rate explained on average 67% of the less-than-expected weight loss, and variability in the proportion of weight lost as FM accounted for a further 5%. On average, after adjustment for changes in metabolic rate and body composition of weight lost, actual weight loss reached 90% of the predicted values. Although weight loss was 33% lower than predicted at baseline from standard energy equivalents, the majority of this differential was explained by physiological variables. Although lower-than-expected weight loss is often attributed to incomplete adherence to prescribed interventions, the influence of baseline calculation errors and metabolic downregulation should not be discounted.

Heart rate variability and cognitive processing: The autonomic response to task demands.

PubMed

Luque-Casado, Antonio; Perales, José C; Cárdenas, David; Sanabria, Daniel

2016-01-01

This study investigated variations in heart rate variability (HRV) as a function of cognitive demands. Participants completed an execution condition including the psychomotor vigilance task, a working memory task and a duration discrimination task. The control condition consisted of oddball versions (participants had to detect the rare event) of the tasks from the execution condition, designed to control for the effect of the task parameters (stimulus duration and stimulus rate) on HRV. The NASA-TLX questionnaire was used as a subjective measure of cognitive workload across tasks and conditions. Three major findings emerged from this study. First, HRV varied as a function of task demands (with the lowest values in the working memory task). Second, and crucially, we found similar HRV values when comparing each of the tasks with its oddball control equivalent, and a significant decrement in HRV as a function of time-on-task. Finally, the NASA-TLX results showed larger cognitive workload in the execution condition than in the oddball control condition, and scores variations as a function of task. Taken together, our results suggest that HRV is highly sensitive to overall demands of sustained attention over and above the influence of other cognitive processes suggested by previous literature. In addition, our study highlights a potential dissociation between objective and subjective measures of mental workload, with important implications in applied settings. Copyright © 2015 Elsevier B.V. All rights reserved.

Sensory Substitution: The Spatial Updating of Auditory Scenes “Mimics” the Spatial Updating of Visual Scenes

PubMed Central

Pasqualotto, Achille; Esenkaya, Tayfun

2016-01-01

Visual-to-auditory sensory substitution is used to convey visual information through audition, and it was initially created to compensate for blindness; it consists of software converting the visual images captured by a video-camera into the equivalent auditory images, or “soundscapes”. Here, it was used by blindfolded sighted participants to learn the spatial position of simple shapes depicted in images arranged on the floor. Very few studies have used sensory substitution to investigate spatial representation, while it has been widely used to investigate object recognition. Additionally, with sensory substitution we could study the performance of participants actively exploring the environment through audition, rather than passively localizing sound sources. Blindfolded participants egocentrically learnt the position of six images by using sensory substitution and then a judgment of relative direction task (JRD) was used to determine how this scene was represented. This task consists of imagining being in a given location, oriented in a given direction, and pointing towards the required image. Before performing the JRD task, participants explored a map that provided allocentric information about the scene. Although spatial exploration was egocentric, surprisingly we found that performance in the JRD task was better for allocentric perspectives. This suggests that the egocentric representation of the scene was updated. This result is in line with previous studies using visual and somatosensory scenes, thus supporting the notion that different sensory modalities produce equivalent spatial representation(s). Moreover, our results have practical implications to improve training methods with sensory substitution devices (SSD). PMID:27148000

Using Analogs for Performance Testing of Humans in Spacesuits in Simulated Reduced Gravity

NASA Technical Reports Server (NTRS)

Norcross, Jason R.

2013-01-01

In general metabolic rates tend to be higher in NBL than in flight: a) Restraint method dependant; b) Significant differences between the NBL and flight for BRT and APFR (buoyancy effects). c) No significant difference between NBL and flight for free float and SRMS/SSRMS operations. The total metabolic energy expenditure for a given task and for the EVA as a whole are similar between NBL and flight: a) NBL metabolic rates are higher, but training EVAs are constrained to 5 1/2 hours. b) Flight metabolic rates are lower, but the EVAs are typically an hour or more longer in duration. NBL metabolic rates provide a useful operational tool for flight planning. Quantifying differences and similarities between training and flight improves knowledge for preparation of safe and efficient EVAs.

Short- and medium-chain fatty acids in energy metabolism: the cellular perspective

PubMed Central

Schönfeld, Peter; Wojtczak, Lech

2016-01-01

Short- and medium-chain fatty acids (SCFAs and MCFAs), independently of their cellular signaling functions, are important substrates of the energy metabolism and anabolic processes in mammals. SCFAs are mostly generated by colonic bacteria and are predominantly metabolized by enterocytes and liver, whereas MCFAs arise mostly from dietary triglycerides, among them milk and dairy products. A common feature of SCFAs and MCFAs is their carnitine-independent uptake and intramitochondrial activation to acyl-CoA thioesters. Contrary to long-chain fatty acids, the cellular metabolism of SCFAs and MCFAs depends to a lesser extent on fatty acid-binding proteins. SCFAs and MCFAs modulate tissue metabolism of carbohydrates and lipids, as manifested by a mostly inhibitory effect on glycolysis and stimulation of lipogenesis or gluconeogenesis. SCFAs and MCFAs exert no or only weak protonophoric and lytic activities in mitochondria and do not significantly impair the electron transport in the respiratory chain. SCFAs and MCFAs modulate mitochondrial energy production by two mechanisms: they provide reducing equivalents to the respiratory chain and partly decrease efficacy of oxidative ATP synthesis. PMID:27080715

Temporal fluxomics reveals oscillations in TCA cycle flux throughout the mammalian cell cycle.

PubMed

Ahn, Eunyong; Kumar, Praveen; Mukha, Dzmitry; Tzur, Amit; Shlomi, Tomer

2017-11-06

Cellular metabolic demands change throughout the cell cycle. Nevertheless, a characterization of how metabolic fluxes adapt to the changing demands throughout the cell cycle is lacking. Here, we developed a temporal-fluxomics approach to derive a comprehensive and quantitative view of alterations in metabolic fluxes throughout the mammalian cell cycle. This is achieved by combining pulse-chase LC-MS-based isotope tracing in synchronized cell populations with computational deconvolution and metabolic flux modeling. We find that TCA cycle fluxes are rewired as cells progress through the cell cycle with complementary oscillations of glucose versus glutamine-derived fluxes: Oxidation of glucose-derived flux peaks in late G1 phase, while oxidative and reductive glutamine metabolism dominates S phase. These complementary flux oscillations maintain a constant production rate of reducing equivalents and oxidative phosphorylation flux throughout the cell cycle. The shift from glucose to glutamine oxidation in S phase plays an important role in cell cycle progression and cell proliferation. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Metabolomics Analysis of Human Vitreous in Diabetic Retinopathy and Rhegmatogenous Retinal Detachment.

PubMed

Haines, Nathan R; Manoharan, Niranjan; Olson, Jeffrey L; D'Alessandro, Angelo; Reisz, Julie A

2018-06-19

The vitreous humor is a highly aqueous eye fluid interfacing with the retina and lens and providing shape. Its molecular composition provides a readout for the eye's physiological status. Changes in cellular metabolism underlie vitreoretinal pathologies, but despite routine surgical collection of vitreous, only limited reports of metabolism in the vitreous of human patients have been described. Vitreous samples from patients with rhegmatogenous retinal detachment ( n = 25) and proliferative diabetic retinopathy ( n = 9) were profiled along with control human vitreous samples ( n = 8) by untargeted mass-spectrometry-based metabolomics. Profound changes were observed in diabetic retinopathy vitreous, including altered glucose metabolism and activation of the pentose phosphate pathway, which provides reducing equivalents to counter oxidative stress. In addition, purine metabolism was altered in diabetic retinopathy, with decreased xanthine and elevated levels of related purines (inosine, hypoxanthine, urate, allantoate) generated in oxidant-producing reactions. In contrast, the vitreous metabolite profiles of retinal detachment patients were similar to controls. In total, our results suggest a rewiring of vitreous metabolism in diabetic retinopathy that underlies disease features such as oxidative stress and furthermore illustrates how the vitreous metabolic profile may be impacted by disease.

Distance and direction, but not light cues, support response reversal learning.

PubMed

Wright, S L; Martin, G M; Thorpe, C M; Haley, K; Skinner, D M

2018-03-05

Across three experiments, we examined the cuing properties of metric (distance and direction) and nonmetric (lighting) cues in different tasks. In Experiment 1, rats were trained on a response problem in a T-maze, followed by four reversals. Rats that experienced a change in maze orientation (Direction group) or a change in the length of the start arm (Distance group) across reversals showed facilitation of reversal learning relative to a group that experienced changes in room lighting across reversals. In Experiment 2, rats learned a discrimination task more readily when distance or direction cues were used than when light cues were used as the discriminative stimuli. In Experiment 3, performance on a go/no-go task was equivalent using both direction and lighting cues. The successful use of both metric and nonmetric cues in the go/no-go task indicates that rats are sensitive to both types of cues and that the usefulness of different cues is dependent on the nature of the task.

Intact implicit learning in autism spectrum conditions.

PubMed

Brown, Jamie; Aczel, Balazs; Jiménez, Luis; Kaufman, Scott Barry; Grant, Kate Plaisted

2010-09-01

Individuals with autism spectrum condition (ASC) have diagnostic impairments in skills that are associated with an implicit acquisition; however, it is not clear whether ASC individuals show specific implicit learning deficits. We compared ASC and typically developing (TD) individuals matched for IQ on five learning tasks: four implicit learning tasks--contextual cueing, serial reaction time, artificial grammar learning, and probabilistic classification learning tasks--that used procedures expressly designed to minimize the use of explicit strategies, and one comparison explicit learning task, paired associates learning. We found implicit learning to be intact in ASC. Beyond no evidence of differences, there was evidence of statistical equivalence between the groups on all the implicit learning tasks. This was not a consequence of compensation by explicit learning ability or IQ. Furthermore, there was no evidence to relate implicit learning to ASC symptomatology. We conclude that implicit mechanisms are preserved in ASC and propose that it is disruption by other atypical processes that impact negatively on the development of skills associated with an implicit acquisition.

The effects of bilingual growth on toddlers’ executive function

PubMed Central

Crivello, Cristina; Kuzyk, Olivia; Rodrigues, Monyka; Friend, Margaret; Zesiger, Pascal; Poulin-Dubois, Diane

2015-01-01

The mastery of two languages provides bilingual speakers with cognitive benefits over monolinguals, particularly on cognitive flexibility and selective attention. However, extant research is limited to comparisons between monolinguals and bilinguals at a single point in time. This study investigated whether growth in bilingual proficiency, as shown by an increased number of translation equivalents (TEs) over a 7-month period, improves executive function. We hypothesized that bilingual toddlers with a larger increase of TEs would have more practice in switching across lexical systems, boosting executive function abilities. Expressive vocabulary and TEs were assessed at 24 and 31 months of age. A battery of tasks, including conflict, delay, and working memory tasks, was administered at 31 months. As expected, we observed a task-specific advantage in inhibitory control in bilinguals. More important, within the bilingual group, larger increases in the number of TEs predicted better performance on conflict tasks but not on delay tasks. This unique longitudinal design confirms the relation between executive function and early bilingualism. PMID:26402219

The contribution of apathy and increased learning trials to risky decision-making in Parkinson's disease.

PubMed

Buelow, Melissa T; Frakey, Laura L; Grace, Janet; Friedman, Joseph H

2014-02-01

Impairments in executive functioning are commonly found in Parkinson's disease (PD); however, the research into risky decision making has been mixed. The present study sought to investigate three potential hypotheses: difficulty learning the task probabilities, levodopa equivalent dose (LED), and the presence of apathy. Twenty-four individuals with idiopathic PD and 13 healthy controls completed the Frontal Systems Behavior Scale to assess current apathy, the Iowa Gambling Task, and the Balloon Analog Risk Task (BART). Results indicated that individuals with PD selected more from Deck B, a disadvantageous deck. However, with an additional set of trials, participants with PD and apathy selected more from the most risky deck (Deck A). Apathy was not related to the BART, and LED was not related to either task. Results indicate that apathy is associated with decision-making in PD, and providing additional learning trials can improve decision-making in PD without apathy.

Does incongruence of lexicosemantic and prosodic information cause discernible cognitive conflict?

PubMed

Mitchell, Rachel L C

2006-12-01

We are often required to interpret discordant emotional signals. Whereas equivalent cognitive paradigms cause noticeable conflict via their behavioral and psychophysiological effects, the same may not necessarily be true for discordant emotions. Skin conductance responses (SCRs) and heart rates (HRs) were measured during a classic Stroop task and one in which the emotions conveyed by lexicosemantic content and prosody were congruent or incongruent. The participants' task was to identify the emotion conveyed by lexicosemantic content or prosody. No relationship was observed between HR and congruence. SCR was higher during incongruent than during congruent conditions of the experimental task (as well as in the classic Stroop task), but no difference in SCR was observed in a comparison between congruence effects during lexicosemantic emotion identification and those during prosodic emotion identification. It is concluded that incongruence between lexicosemantic and prosodic emotion does cause notable cognitive conflict. Functional neuroanatomic implications are discussed.

Theory of mind and central coherence in adults with high-functioning autism or Asperger syndrome.

PubMed

Beaumont, Renae; Newcombe, Peter

2006-07-01

The study investigated theory of mind and central coherence abilities in adults with high-functioning autism (HFA) or Asperger syndrome (AS) using naturalistic tasks. Twenty adults with HFA/AS correctly answered significantly fewer theory of mind questions than 20 controls on a forced-choice response task. On a narrative task, there were no differences in the proportion of mental state words between the two groups, although the participants with HFA/AS were less inclined to provide explanations for characters' mental states. No between-group differences existed on the central coherence questions of the forced-choice response task, and the participants with HFA/AS included an equivalent proportion of explanations for non-mental state phenomena in their narratives as did controls. These results support the theory of mind deficit account of autism spectrum disorders, and suggest that difficulties in mental state attribution cannot be exclusively attributed to weak central coherence.

Cognitive and Physical Fatigue Tasks Enhance Pain, Cognitive Fatigue and Physical Fatigue in People with Fibromyalgia

PubMed Central

Dailey, Dana L; Keffala, Valerie J; Sluka, Kathleen A

2014-01-01

Objective Fibromyalgia is a condition characterized by chronic widespread muscle pain and fatigue. The primary objective of this study was to determine if pain, perceived cognitive fatigue, and perceived physical fatigue were enhanced in participants with fibromyalgia compared to healthy controls during a cognitive fatigue task, a physical fatigue task and a dual fatigue task. Methods Twenty four people with fibromyalgia and 33 healthy controls completed pain, fatigue and function measures. A cognitive fatigue task (Controlled Oral Word Association Test) and physical fatigue task (Valpar peg test) were done individually and combined for a dual fatigue task. Resting pain, perceived cognitive fatigue and perceived physical fatigue were assessed during each task using visual analogue scales. Function was assessed with shoulder range of motion and grip. Results People with fibromyalgia had significantly higher increases in pain, cognitive fatigue and physical fatigue when compared to healthy controls after completion of a cognitive fatigue task, a physical fatigue task, or a dual fatigue task (p<0.01). People with fibromyalgia performed equivalently on measures of physical performance and cognitive performance on the physical and cognitive fatigue tasks, respectively. Conclusions These data show that people with fibromyalgia show larger increases in pain, perceived cognitive fatigue and perceived physical fatigue to both cognitive and physical fatigue tasks compared to healthy controls. The increases in pain and fatigue during cognitive and physical fatigue tasks could influence subject participation in daily activities and rehabilitation. PMID:25074583

One-Carbon Metabolism and Breast Cancer Survival in a Population-Based Study

DTIC Science & Technology

2007-06-01

methylation patterns; gene promoter methylation pattern and overall survival; and one-carbon polymorphisms and treatment regimen in relation to survival... treatment strategy. BODY Task 1. To genotype polymorphisms in one-carbon-metabolizing genes on 1087 BC cases (Months 1- 24) Genotyping...modifying effect of one-carbon gene polymorphisms on chemotherapy response in relation to breast cancer survival. Results were summarized in Table 2. The

Dosimetric assessment from 212Pb inhalation at a thorium purification plant.

PubMed

Campos, M P; Pecequilo, B R S

2004-01-01

At the Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, Brazil, there is a facility (thorium purification plant) where materials with high thorium concentrations are manipulated. In order to estimate afterwards the lung cancer risk for the workers, the thoron daughter (212Pb) levels were assessed and the committed effective and lung committed equivalent doses for workers in place. A total of 28 air filter samples were measured by total alpha counting through the modified Kusnetz method, to determine the 212Pb concentraion. The committed effective dose and lung committed equivalent dose due to 212Pb inhalation were derived from compartmental analysis following the ICRP 66 lung compartmental model, and ICRP 67 lead metabolic model.

Topical treatment with coenzyme Q10-containing formulas improves skin's Q10 level and provides antioxidative effects.

PubMed

Knott, Anja; Achterberg, Volker; Smuda, Christoph; Mielke, Heiko; Sperling, Gabi; Dunckelmann, Katja; Vogelsang, Alexandra; Krüger, Andrea; Schwengler, Helge; Behtash, Mojgan; Kristof, Sonja; Diekmann, Heike; Eisenberg, Tanya; Berroth, Andreas; Hildebrand, Janosch; Siegner, Ralf; Winnefeld, Marc; Teuber, Frank; Fey, Sven; Möbius, Janne; Retzer, Dana; Burkhardt, Thorsten; Lüttke, Juliane; Blatt, Thomas

2015-01-01

Ubiquinone (coenzyme Q10, Q10) represents an endogenously synthesized lipid-soluble antioxidant which is crucial for cellular energy production but is diminished with age and under the influence of external stress factors in human skin. Here, it is shown that topical Q10 treatment is beneficial with regard to effective Q10 replenishment, augmentation of cellular energy metabolism, and antioxidant effects. Application of Q10-containing formulas significantly increased the levels of this quinone on the skin surface. In the deeper layers of the epidermis the ubiquinone level was significantly augmented indicating effective supplementation. Concurrent elevation of ubiquinol levels suggested metabolic transformation of ubiquinone resulting from increased energy metabolism. Incubation of cultured human keratinocytes with Q10 concentrations equivalent to treated skin showed a significant augmentation of energy metabolism. Moreover, the results demonstrated that stressed skin benefits from the topical Q10 treatment by reduction of free radicals and an increase in antioxidant capacity. © 2015 International Union of Biochemistry and Molecular Biology.

Effects of long-term captivity on thermoregulation, metabolism and ventilation of the southern brown bandicoot (Marsupialia: Peramelidae).

PubMed

Larcombe, Alexander N; Withers, Philip C

2007-02-01

Thermoneutral metabolic and ventilatory parameters were measured every 3 months over 2 years for southern brown bandicoots held in captivity, and from a nearby reserve. Captive bandicoots were 130 g (9.9%) heavier than wild bandicoots. Long-term captivity had no effect on body temperature, basal metabolic rate (oxygen consumption), thermal conductance or respiratory ventilation, but there was an effect on carbon dioxide production, respiratory exchange ratio and total evaporative water loss (values were between 15 and 25% higher for captive than for wild bandicoots). Diet may be influencing these aspects of captive bandicoot physiology; the diet of captive bandicoots would be considerably different to that of wild bandicoots. Water availability seems to have a minimal effect. This study has important implications regarding physiological measurement for captive and wild mammals. For bandicoots at least, captive animals are equivalent to wild animals for some physiological parameters at thermoneutrality (body temperature, resting metabolic rate and thermal conductance), but not others.

A common scaling rule for abundance, energetics, and production of parasitic and free-living species

USGS Publications Warehouse

Hechinger, Ryan F.; Lafferty, Kevin D.; Dobson, Andy P.; Brown, James H.; Kuris, Armand M.

2011-01-01

The metabolic theory of ecology uses the scaling of metabolism with body size and temperature to explain the causes and consequences of species abundance. However, the theory and its empirical tests have never simultaneously examined parasites alongside free-living species. This is unfortunate because parasites represent at least half of species diversity. We show that metabolic scaling theory could not account for the abundance of parasitic or free-living species in three estuarine food webs until accounting for trophic dynamics. Analyses then revealed that the abundance of all species uniformly scaled with body mass to the - 3/4 power. This result indicates "production equivalence," where biomass production within trophic levels is invariant of body size across all species and functional groups: invertebrate or vertebrate, ectothermic or endothermic, and free-living or parasitic.

A novel Bayesian approach to accounting for uncertainty in fMRI-derived estimates of cerebral oxygen metabolism fluctuations

PubMed Central

Simon, Aaron B.; Dubowitz, David J.; Blockley, Nicholas P.; Buxton, Richard B.

2016-01-01

Calibrated blood oxygenation level dependent (BOLD) imaging is a multimodal functional MRI technique designed to estimate changes in cerebral oxygen metabolism from measured changes in cerebral blood flow and the BOLD signal. This technique addresses fundamental ambiguities associated with quantitative BOLD signal analysis; however, its dependence on biophysical modeling creates uncertainty in the resulting oxygen metabolism estimates. In this work, we developed a Bayesian approach to estimating the oxygen metabolism response to a neural stimulus and used it to examine the uncertainty that arises in calibrated BOLD estimation due to the presence of unmeasured model parameters. We applied our approach to estimate the CMRO2 response to a visual task using the traditional hypercapnia calibration experiment as well as to estimate the metabolic response to both a visual task and hypercapnia using the measurement of baseline apparent R2′ as a calibration technique. Further, in order to examine the effects of cerebral spinal fluid (CSF) signal contamination on the measurement of apparent R2′, we examined the effects of measuring this parameter with and without CSF-nulling. We found that the two calibration techniques provided consistent estimates of the metabolic response on average, with a median R2′-based estimate of the metabolic response to CO2 of 1.4%, and R2′- and hypercapnia-calibrated estimates of the visual response of 27% and 24%, respectively. However, these estimates were sensitive to different sources of estimation uncertainty. The R2′-calibrated estimate was highly sensitive to CSF contamination and to uncertainty in unmeasured model parameters describing flow-volume coupling, capillary bed characteristics, and the iso-susceptibility saturation of blood. The hypercapnia-calibrated estimate was relatively insensitive to these parameters but highly sensitive to the assumed metabolic response to CO2. PMID:26790354

A novel Bayesian approach to accounting for uncertainty in fMRI-derived estimates of cerebral oxygen metabolism fluctuations.

PubMed

Simon, Aaron B; Dubowitz, David J; Blockley, Nicholas P; Buxton, Richard B

2016-04-01

Calibrated blood oxygenation level dependent (BOLD) imaging is a multimodal functional MRI technique designed to estimate changes in cerebral oxygen metabolism from measured changes in cerebral blood flow and the BOLD signal. This technique addresses fundamental ambiguities associated with quantitative BOLD signal analysis; however, its dependence on biophysical modeling creates uncertainty in the resulting oxygen metabolism estimates. In this work, we developed a Bayesian approach to estimating the oxygen metabolism response to a neural stimulus and used it to examine the uncertainty that arises in calibrated BOLD estimation due to the presence of unmeasured model parameters. We applied our approach to estimate the CMRO2 response to a visual task using the traditional hypercapnia calibration experiment as well as to estimate the metabolic response to both a visual task and hypercapnia using the measurement of baseline apparent R2' as a calibration technique. Further, in order to examine the effects of cerebral spinal fluid (CSF) signal contamination on the measurement of apparent R2', we examined the effects of measuring this parameter with and without CSF-nulling. We found that the two calibration techniques provided consistent estimates of the metabolic response on average, with a median R2'-based estimate of the metabolic response to CO2 of 1.4%, and R2'- and hypercapnia-calibrated estimates of the visual response of 27% and 24%, respectively. However, these estimates were sensitive to different sources of estimation uncertainty. The R2'-calibrated estimate was highly sensitive to CSF contamination and to uncertainty in unmeasured model parameters describing flow-volume coupling, capillary bed characteristics, and the iso-susceptibility saturation of blood. The hypercapnia-calibrated estimate was relatively insensitive to these parameters but highly sensitive to the assumed metabolic response to CO2. Copyright © 2016 Elsevier Inc. All rights reserved.

Action Identity in Style Simulation Systems: Do Players Consider Machine-Generated Music As of Their Own Style?

PubMed

Khatchatourov, Armen; Pachet, François; Rowe, Victoria

2016-01-01

The generation of musical material in a given style has been the subject of many studies with the increased sophistication of artificial intelligence models of musical style. In this paper we address a question of primary importance for artificial intelligence and music psychology: can such systems generate music that users indeed consider as corresponding to their own style? We address this question through an experiment involving both performance and recognition tasks with musically naïve school-age children. We asked 56 children to perform a free-form improvisation from which two kinds of music excerpt were created. One was a mere recording of original performances. The other was created by a software program designed to simulate the participants' style, based on their original performances. Two hours after the performance task, the children completed the recognition task in two conditions, one with the original excerpts and one with machine-generated music. Results indicate that the success rate is practically equivalent in two conditions: children tended to make correct attribution of the excerpts to themselves or to others, whether the music was human-produced or machine-generated (mean accuracy = 0.75 and = 0.71, respectively). We discuss this equivalence in accuracy for machine-generated and human produced music in the light of the literature on memory effects and action identity which addresses the recognition of one's own production.

Action Identity in Style Simulation Systems: Do Players Consider Machine-Generated Music As of Their Own Style?

PubMed Central

Khatchatourov, Armen; Pachet, François; Rowe, Victoria

2016-01-01

The generation of musical material in a given style has been the subject of many studies with the increased sophistication of artificial intelligence models of musical style. In this paper we address a question of primary importance for artificial intelligence and music psychology: can such systems generate music that users indeed consider as corresponding to their own style? We address this question through an experiment involving both performance and recognition tasks with musically naïve school-age children. We asked 56 children to perform a free-form improvisation from which two kinds of music excerpt were created. One was a mere recording of original performances. The other was created by a software program designed to simulate the participants' style, based on their original performances. Two hours after the performance task, the children completed the recognition task in two conditions, one with the original excerpts and one with machine-generated music. Results indicate that the success rate is practically equivalent in two conditions: children tended to make correct attribution of the excerpts to themselves or to others, whether the music was human-produced or machine-generated (mean accuracy = 0.75 and = 0.71, respectively). We discuss this equivalence in accuracy for machine-generated and human produced music in the light of the literature on memory effects and action identity which addresses the recognition of one's own production. PMID:27199788

Precision metabolic engineering: The design of responsive, selective, and controllable metabolic systems.

PubMed

McNerney, Monica P; Watstein, Daniel M; Styczynski, Mark P

2015-09-01

Metabolic engineering is generally focused on static optimization of cells to maximize production of a desired product, though recently dynamic metabolic engineering has explored how metabolic programs can be varied over time to improve titer. However, these are not the only types of applications where metabolic engineering could make a significant impact. Here, we discuss a new conceptual framework, termed "precision metabolic engineering," involving the design and engineering of systems that make different products in response to different signals. Rather than focusing on maximizing titer, these types of applications typically have three hallmarks: sensing signals that determine the desired metabolic target, completely directing metabolic flux in response to those signals, and producing sharp responses at specific signal thresholds. In this review, we will first discuss and provide examples of precision metabolic engineering. We will then discuss each of these hallmarks and identify which existing metabolic engineering methods can be applied to accomplish those tasks, as well as some of their shortcomings. Ultimately, precise control of metabolic systems has the potential to enable a host of new metabolic engineering and synthetic biology applications for any problem where flexibility of response to an external signal could be useful. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Automated design of genetic toggle switches with predetermined bistability.

PubMed

Chen, Shuobing; Zhang, Haoqian; Shi, Handuo; Ji, Weiyue; Feng, Jingchen; Gong, Yan; Yang, Zhenglin; Ouyang, Qi

2012-07-20

Synthetic biology aims to rationally construct biological devices with required functionalities. Methods that automate the design of genetic devices without post-hoc adjustment are therefore highly desired. Here we provide a method to predictably design genetic toggle switches with predetermined bistability. To accomplish this task, a biophysical model that links ribosome binding site (RBS) DNA sequence to toggle switch bistability was first developed by integrating a stochastic model with RBS design method. Then, to parametrize the model, a library of genetic toggle switch mutants was experimentally built, followed by establishing the equivalence between RBS DNA sequences and switch bistability. To test this equivalence, RBS nucleotide sequences for different specified bistabilities were in silico designed and experimentally verified. Results show that the deciphered equivalence is highly predictive for the toggle switch design with predetermined bistability. This method can be generalized to quantitative design of other probabilistic genetic devices in synthetic biology.

Seeing the World through Another Person's Eyes: Simulating Selective Attention via Action Observation

ERIC Educational Resources Information Center

Frischen, Alexandra; Loach, Daniel; Tipper, Steven P.

2009-01-01

Selective attention is usually considered an egocentric mechanism, biasing sensory information based on its behavioural relevance to oneself. This study provides evidence for an equivalent allocentric mechanism that allows passive observers to selectively attend to information from the perspective of another person. In a negative priming task,…

Study to encourage and facilitate industrial investment and involvement in space

NASA Technical Reports Server (NTRS)

Wilson, J. E.

1984-01-01

A simple and efficient means to alert the Director, Space Station Commercialization Task Force (DSCTF) and the equivalent director of a permanent office for the same function, to actions required to assure comprehensive support of the NASA objectives for commercial uses of space during the annual budget cycle is described.

Comparing Dichotomous and Trichotomous Approaches to Achievement Goal Theory: An Example Using Motivational Regulations as Outcome Variables

ERIC Educational Resources Information Center

Barkoukis, Vassilis; Ntoumanis, Nikos; Nikitaras, Nikitas

2007-01-01

Background: It is commonly assumed that there is conceptual equivalence between the task and ego achievement goals proposed by Nicholl's (1989) dichotomous achievement goal theory (Nicholls, 1989), and the mastery and performance approach goals advanced by Elliot's (1997) trichotomous hierarchical model of approach and avoidance achievement…

Reducing Probabilistic Weather Forecasts to the Worst-Case Scenario: Anchoring Effects

ERIC Educational Resources Information Center

Joslyn, Susan; Savelli, Sonia; Nadav-Greenberg, Limor

2011-01-01

Many weather forecast providers believe that forecast uncertainty in the form of the worst-case scenario would be useful for general public end users. We tested this suggestion in 4 studies using realistic weather-related decision tasks involving high winds and low temperatures. College undergraduates, given the statistical equivalent of the…

Equivalence of Screen versus Print Reading Comprehension Depends on Task Complexity and Proficiency

ERIC Educational Resources Information Center

Lenhard, Wolfgang; Schroeders, Ulrich; Lenhard, Alexandra

2017-01-01

As reading and reading assessment become increasingly implemented on electronic devices, the question arises whether reading on screen is comparable with reading on paper. To examine potential differences, we studied reading processes on different proficiency and complexity levels. Specifically, we used data from the standardization sample of the…

Vocabulary Size, Translation Equivalents, and Efficiency in Word Recognition in Very Young Bilinguals

ERIC Educational Resources Information Center

Legacy, Jacqueline; Zesiger, Pascal; Friend, Margaret; Poulin-Dubois, Diane

2016-01-01

The present study examined early vocabulary development in fifty-nine French monolingual and fifty French-English bilingual infants (1;4-1;6). Vocabulary comprehension was assessed using both parental report (MacArthur-Bates Communicative Development Inventory; CDI) and the Computerized Comprehension Task (CCT). When assessing receptive vocabulary…

The Acquisition of Notions of Qualitative Speed: The Importance of Spatial and Temporal Alignment.

ERIC Educational Resources Information Center

Perry, Bruce; Obenauf, Patricia

1987-01-01

Reports on a study which investigated the order of acquisition of intuitive notions of qualitative speed. Results indicated that an array of prerequisites, equivalent, and independent relationships existed among the tasks administered. Confirmed the evolution of reasoning for notions of qualitative speed found by Piaget. (Author/TW)

The Development of a Bilingual Vocabulary Measure for Armenian-English Children

ERIC Educational Resources Information Center

Hovsepian, Alice

2017-01-01

The purpose of this study was to develop a parallel bilingual vocabulary measure for the comparative study of receptive and expressive vocabulary growth in young Armenian-English bilinguals. The measure was comprised of four independent vocabulary lists equivalent on age of acquisition ratings. The lists were counterbalanced across four tasks,…

L2 Processing of Plural Inflection in English

ERIC Educational Resources Information Center

Song, Yoonsang

2015-01-01

This study investigates (1) whether late second language (L2) learners can attain native-like knowledge of English plural inflection even when their first language (L1) lacks an equivalent and (2) whether they construct hierarchically structured representations during online sentence processing like native speakers. In a self-paced reading task,…

The need for monitoring metabolic status

NASA Astrophysics Data System (ADS)

Vanderveen, John E.

2005-05-01

Modern military operations utilize complex technologies that require high levels of readiness and sustained cognitive and physical performance of combat military combat personnel. These military operations often depend on weapon systems that use advanced computer technology coupled with an array of sensors that provide continuous information on the battlefield environment and on equipment function. However there is a lack of real-time information on status of the personnel who control these systems and who are vital to mission success. Failure of the human element renders the weapon system useless so it is important to know if an individual is physically and cognitively fit to perform his or her task. Based on the premise that status of metabolic processes provide an early indication of a change in an individuals physiological status, monitoring of selective biomarkers of metabolism and organ function can provide insight on the individual"s ability to perform mission tasks. During combat individuals may not be aware that they have reached a compromised physiological condition due to dehydration, physical exertion, stress, fatigue, sleep deprivation, exposure to toxins or other condition that may affect physical and cognitive performance and health. Systems that can provide the individual or his or her commander with information about significant changes in one or more metabolic functions could permit timely intervention to correct the condition. In the event that serious injury has already occurred to an individual, metabolic monitoring can provide valuable intelligence needed for decisions on achieving mission objectives.

[Evaluation of metabolic rate for a correct risk assessment of thermal environments].

PubMed

Del Ferraro, Simona; Molinaro, V

2010-01-01

The new law n.81/2008 recognises microclimate as one of physical agents for which risk assessment becomes obligatory. To achieve this it is necessary to evaluate suitable indices, based on heat balance equation, which depend on six parameters: the first four are related to thermal environment and the last two are related to the worker (metabolic rate and thermal insulation). The first four parameters are directly measurable in situ by using a multiple data acquisition unit provided with suitable sensors. Parameters related to the worker are not directly measurable. This aspect represents one of the problems which can lead to an inaccurate risk assessment. Aim of the paper was to identify a method which leads to a correct evaluation of the metabolic rate related to the worker under study. It was decided to follow the procedures described by the standard UNI EN ISO 8996:2005 which presents four different levels to evaluate metabolic rate, each one with an increasing degree of accuracy. Seven workers were selected: three performed light tasks and the other four did heavy work. The study showed that the results appear to be in acceptable agreement in the case of light work while there were detectable differences in value for heavy tasks. The Authors believe it is necessary to stress the importance of a suitable estimation of the metabolic rate in order to carry out a correct risk assessment which quantifies the risk exactly.

Linking Caregiver Strain to Diabetes Illness Management and Health Outcomes in a Sample of Adolescents in Chronically Poor Metabolic Control

PubMed Central

Carcone, April Idalski; Ellis, Deborah A.; Naar-King, Sylvie

2012-01-01

Objective This study examined a multivariate model of the relationship between caregiver strain and adolescent diabetes illness outcomes in a sample of caregivers of adolescents in chronically poor metabolic control (Hba1c ≥ 8.0% at enrollment and for previous 12 months). Caregiver mental health symptoms were hypothesized to mediate the relationship between caregiver strain and adolescent illness management behavior and metabolic control. Caregivers’ perceptions of social support and their level of responsibility for diabetes care tasks were hypothesized to be directly related to caregiver strain and indirectly to caregiver mental health symptoms. Method One hundred forty-six caregiver-adolescent dyads completed baseline measures of caregiver strain, responsibility for diabetes care, social support, mental health symptoms, and illness management behavior. Adolescent metabolic control was also assessed. Results Findings from structural equation modeling suggested that caregiver strain was directly and positively associated with caregiver mental health symptoms which mediated the relationship to adolescent diabetes management behavior and metabolic control. Caregivers’ responsibility for diabetes care tasks was directly related to caregiver strain and indirectly to caregiver mental health, but caregiver perceptions of social support was not. Conclusions These findings suggest that caregiver strain is an important dimension of the caregiving context of diabetes. Clinicians and researchers should consider how caregiving strain, responsibility for illness management, and mental health symptoms might be impacting children’s diabetes care behavior and diabetes health when working with and designing interventions for adolescents with diabetes. PMID:22566030

Are visual cue masking and removal techniques equivalent for studying perceptual skills in sport?

PubMed

Mecheri, Sami; Gillet, Eric; Thouvarecq, Regis; Leroy, David

2011-01-01

The spatial-occlusion paradigm makes use of two techniques (masking and removing visual cues) to provide information about the anticipatory cues used by viewers. The visual scene resulting from the removal technique appears to be incongruous, but the assumed equivalence of these two techniques is spreading. The present study was designed to address this issue by combining eye-movement recording with the two types of occlusion (removal versus masking) in a tennis serve-return task. Response accuracy and decision onsets were analysed. The results indicated that subjects had longer reaction times under the removal condition, with an identical proportion of correct responses. Also, the removal technique caused the subjects to rely on atypical search patterns. Our findings suggest that, when the removal technique was used, viewers were unable to systematically count on stored memories to help them accomplish the interception task. The persistent failure to question some of the assumptions about the removal technique in applied visual research is highlighted, and suggestions for continued use of the masking technique are advanced.

Rapid Decisions From Experience

PubMed Central

Zeigenfuse, Matthew D.; Pleskac, Timothy J.; Liu, Taosheng

2014-01-01

In many everyday decisions, people quickly integrate noisy samples of information to form a preference among alternatives that offer uncertain rewards. Here, we investigated this decision process using the Flash Gambling Task (FGT), in which participants made a series of choices between a certain payoff and an uncertain alternative that produced a normal distribution of payoffs. For each choice, participants experienced the distribution of payoffs via rapid samples updated every 50 ms. We show that people can make these rapid decisions from experience and that the decision process is consistent with a sequential sampling process. Results also reveal a dissociation between these preferential decisions and equivalent perceptual decisions where participants had to determine which alternatives contained more dots on average. To account for this dissociation, we developed a sequential sampling rank-dependent utility model, which showed that participants in the FGT attended more to larger potential payoffs than participants in the perceptual task despite being given equivalent information. We discuss the implications of these findings in terms of computational models of preferential choice and a more complete understanding of experience-based decision making. PMID:24549141

Piloted Evaluation of a UH-60 Mixer Equivalent Turbulence Simulation Model

NASA Technical Reports Server (NTRS)

Lusardi, Jeff A.; Blanken, Chris L.; Tischeler, Mark B.

2002-01-01

A simulation study of a recently developed hover/low speed Mixer Equivalent Turbulence Simulation (METS) model for the UH-60 Black Hawk helicopter was conducted in the NASA Ames Research Center Vertical Motion Simulator (VMS). The experiment was a continuation of previous work to develop a simple, but validated, turbulence model for hovering rotorcraft. To validate the METS model, two experienced test pilots replicated precision hover tasks that had been conducted in an instrumented UH-60 helicopter in turbulence. Objective simulation data were collected for comparison with flight test data, and subjective data were collected that included handling qualities ratings and pilot comments for increasing levels of turbulence. Analyses of the simulation results show good analytic agreement between the METS model and flight test data, with favorable pilot perception of the simulated turbulence. Precision hover tasks were also repeated using the more complex rotating-frame SORBET (Simulation Of Rotor Blade Element Turbulence) model to generate turbulence. Comparisons of the empirically derived METS model with the theoretical SORBET model show good agreement providing validation of the more complex blade element method of simulating turbulence.

The Social Attribution Task-Multiple Choice (SAT-MC): A Psychometric and Equivalence Study of an Alternate Form.

PubMed

Johannesen, Jason K; Lurie, Jessica B; Fiszdon, Joanna M; Bell, Morris D

2013-01-01

The Social Attribution Task-Multiple Choice (SAT-MC) uses a 64-second video of geometric shapes set in motion to portray themes of social relatedness and intentions. Considered a test of "Theory of Mind," the SAT-MC assesses implicit social attribution formation while reducing verbal and basic cognitive demands required of other common measures. We present a comparability analysis of the SAT-MC and the new SAT-MC-II, an alternate form created for repeat testing, in a university sample (n = 92). Score distributions and patterns of association with external validation measures were nearly identical between the two forms, with convergent and discriminant validity supported by association with affect recognition ability and lack of association with basic visual reasoning. Internal consistency of the SAT-MC-II was superior (alpha = .81) to the SAT-MC (alpha = .56). Results support the use of SAT-MC and new SAT-MC-II as equivalent test forms. Demonstrating relatively higher association to social cognitive than basic cognitive abilities, the SAT-MC may provide enhanced sensitivity as an outcome measure of social cognitive intervention trials.

Energy utilization rates during shuttle extravehicular activities.

PubMed

Waligora, J M; Kumar, K V

1995-01-01

The work rates or energy utilization rates during EVA are major factors in sizing of life support systems. These rates also provide a measure of ease of EVA and its cost in crew fatigue. From the first Shuttle EVA on the STS-6 mission in 1983, we have conducted 59 man-EVA and 341 man-hours of EVA. Energy utilization rates have been measured on each of these EVA. Metabolic rate was measured during each EVA using oxygen utilization corrected for suit leakage. From 1981-1987, these data were available for average data over the EVA or over large segments of the EVA. Since 1987, EVA oxygen utilization data were available at 2-minute intervals. The average metabolic rate on Shuttle EVA (194 kcal/hr.) has been significantly lower than metabolic rates during Apollo and Skylab missions. Peak rates have been below design levels, infrequent, and of short duration. The data suggest that the energy cost of tasks may be inversely related to the degree of training for the task. The data provide insight on the safety margins provided by life support designs and on the energy cost of Station construction EVA.

Metabolically Competent Human Skin Models: Activation and Genotoxicity of Benzo[a]pyrene

PubMed Central

Henkler, Frank

2013-01-01

The polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BP) is metabolized into a complex pattern of BP derivatives, among which the ultimate carcinogen (+)-anti-BP-7,8-diol-9,10-epoxide (BPDE) is formed to certain extents. Skin is frequently in contact with PAHs and data on the metabolic capacity of skin tissue toward these compounds are inconclusive. We compared BP metabolism in excised human skin, commercially available in vitro 3D skin models and primary 2D skin cell cultures, and analyzed the metabolically catalyzed occurrence of seven different BP follow-up products by means of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). All models investigated were competent to metabolize BP, and the metabolic profiles generated by ex vivo human skin and skin models were remarkably similar. Furthermore, the genotoxicity of BP and its derivatives was monitored in these models via comet assays. In a full-thickness skin, equivalent BP-mediated genotoxic stress was generated via keratinocytes. Cultured primary keratinocytes revealed a level of genotoxicity comparable with that of direct exposure to 50–100nM of BPDE. Our data demonstrate that the metabolic capacity of human skin ex vivo, as well as organotypic human 3D skin models toward BP, is sufficient to cause significant genotoxic stress and thus cutaneous bioactivation may potentially contribute to mutations that ultimately lead to skin cancer. PMID:23148024

Battery parameterisation based on differential evolution via a boundary evolution strategy

NASA Astrophysics Data System (ADS)

Yang, Guangya

2014-01-01

Attention has been given to the battery modelling in the electric engineering field following the current development of renewable energy and electrification of transportation. The establishment of the equivalent circuit model of the battery requires data preparation and parameterisation. Besides, as the equivalent circuit model is an abstract map of the battery electric characteristics, the determination of the possible ranges of parameters can be a challenging task. In this paper, an efficient yet easy to implement method is proposed to parameterise the equivalent circuit model of batteries utilising the advances of evolutionary algorithms (EAs). Differential evolution (DE) is selected and modified to parameterise an equivalent circuit model of lithium-ion batteries. A boundary evolution strategy (BES) is developed and incorporated into the DE to update the parameter boundaries during the parameterisation. The method can parameterise the model without extensive data preparation. In addition, the approach can also estimate the initial SOC and the available capacity. The efficiency of the approach is verified through two battery packs, one is an 8-cell battery module and one from an electrical vehicle.

Assessing Measurement Invariance for Spanish Sentence Repetition and Morphology Elicitation Tasks.

PubMed

Kapantzoglou, Maria; Thompson, Marilyn S; Gray, Shelley; Restrepo, M Adelaida

2016-04-01

The purpose of this study was to evaluate evidence supporting the construct validity of two grammatical tasks (sentence repetition, morphology elicitation) included in the Spanish Screener for Language Impairment in Children (Restrepo, Gorin, & Gray, 2013). We evaluated if the tasks measured the targeted grammatical skills in the same way across predominantly Spanish-speaking children with typical language development and those with primary language impairment. A multiple-group, confirmatory factor analytic approach was applied to examine factorial invariance in a sample of 307 predominantly Spanish-speaking children (177 with typical language development; 130 with primary language impairment). The 2 newly developed grammatical tasks were modeled as measures in a unidimensional confirmatory factor analytic model along with 3 well-established grammatical measures from the Clinical Evaluation of Language Fundamentals-Fourth Edition, Spanish (Wiig, Semel, & Secord, 2006). Results suggest that both new tasks measured the construct of grammatical skills for both language-ability groups in an equivalent manner. There was no evidence of bias related to children's language status for the Spanish Screener for Language Impairment in Children Sentence Repetition or Morphology Elicitation tasks. Results provide support for the validity of the new tasks as measures of grammatical skills.

Interval timing in children: effects of auditory and visual pacing stimuli and relationships with reading and attention variables.

PubMed

Birkett, Emma E; Talcott, Joel B

2012-01-01

Motor timing tasks have been employed in studies of neurodevelopmental disorders such as developmental dyslexia and ADHD, where they provide an index of temporal processing ability. Investigations of these disorders have used different stimulus parameters within the motor timing tasks that are likely to affect performance measures. Here we assessed the effect of auditory and visual pacing stimuli on synchronised motor timing performance and its relationship with cognitive and behavioural predictors that are commonly used in the diagnosis of these highly prevalent developmental disorders. Twenty-one children (mean age 9.6 years) completed a finger tapping task in two stimulus conditions, together with additional psychometric measures. As anticipated, synchronisation to the beat (ISI 329 ms) was less accurate in the visually paced condition. Decomposition of timing variance indicated that this effect resulted from differences in the way that visual and auditory paced tasks are processed by central timekeeping and associated peripheral implementation systems. The ability to utilise an efficient processing strategy on the visual task correlated with both reading and sustained attention skills. Dissociations between these patterns of relationship across task modality suggest that not all timing tasks are equivalent.

Hands-free administration of subjective workload scales: acceptability in a surgical training environment.

PubMed

Carswell, C Melody; Lio, Cindy H; Grant, Russell; Klein, Martina I; Clarke, Duncan; Seales, W Brent; Strup, Stephen

2010-12-01

Subjective workload measures are usually administered in a visual-manual format, either electronically or by paper and pencil. However, vocal responses to spoken queries may sometimes be preferable, for example when experimental manipulations require continuous manual responding or when participants have certain sensory/motor impairments. In the present study, we evaluated the acceptability of the hands-free administration of two subjective workload questionnaires - the NASA Task Load Index (NASA-TLX) and the Multiple Resources Questionnaire (MRQ) - in a surgical training environment where manual responding is often constrained. Sixty-four undergraduates performed fifteen 90-s trials of laparoscopic training tasks (five replications of 3 tasks - cannulation, ring transfer, and rope manipulation). Half of the participants provided workload ratings using a traditional paper-and-pencil version of the NASA-TLX and MRQ; the remainder used a vocal (hands-free) version of the questionnaires. A follow-up experiment extended the evaluation of the hands-free version to actual medical students in a Minimally Invasive Surgery (MIS) training facility. The NASA-TLX was scored in 2 ways - (1) the traditional procedure using participant-specific weights to combine its 6 subscales, and (2) a simplified procedure - the NASA Raw Task Load Index (NASA-RTLX) - using the unweighted mean of the subscale scores. Comparison of the scores obtained from the hands-free and written administration conditions yielded coefficients of equivalence of r=0.85 (NASA-TLX) and r=0.81 (NASA-RTLX). Equivalence estimates for the individual subscales ranged from r=0.78 ("mental demand") to r=0.31 ("effort"). Both administration formats and scoring methods were equally sensitive to task and repetition effects. For the MRQ, the coefficient of equivalence for the hands-free and written versions was r=0.96 when tested on undergraduates. However, the sensitivity of the hands-free MRQ to task demands (η(partial)(2)=0.138) was substantially less than that for the written version (η(partial)(2)=0.252). This potential shortcoming of the hands-free MRQ did not seem to generalize to medical students who showed robust task effects when using the hands-free MRQ (η(partial)(2)=0.396). A detailed analysis of the MRQ subscales also revealed differences that may be attributable to a "spillover" effect in which participants' judgments about the demands of completing the questionnaires contaminated their judgments about the primary surgical training tasks. Vocal versions of the NASA-TLX are acceptable alternatives to standard written formats when researchers wish to obtain global workload estimates. However, care should be used when interpreting the individual subscales if the object is to make comparisons between studies or conditions that use different administration modalities. For the MRQ, the vocal version was less sensitive to experimental manipulations than its written counterpart; however, when medical students rather than undergraduates used the vocal version, the instrument's sensitivity increased well beyond that obtained with any other combination of administration modality and instrument in this study. Thus, the vocal version of the MRQ may be an acceptable workload assessment technique for selected populations, and it may even be a suitable substitute for the NASA-TLX. Copyright © 2010 Elsevier Ltd. All rights reserved.

Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs.

PubMed

Sensakovic, William F; O'Dell, M Cody; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura

2016-10-01

Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA(2) by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P < 0.0001). Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image processing can significantly impact image quality when settings are left near default values.

Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

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

Wu, J.C.; Hagman, J.; Buchsbaum, M.S.

1990-03-01

Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion thatmore » bulimia is a diagnostic grouping distinct from these disorders.« less

One-Carbon Metabolism and Breast Cancer Survival in a Population-Based Study

DTIC Science & Technology

2006-06-01

treatment strategy. BODY Task 1. To genotype polymorphisms in one-carbon-metabolizing genes on 1087 BC cases (Months 1- 24) Genotyping has...for treatment of the disease (e.g. 5-FU, methotrexate , etc.). We propose to utilize the resources of the Long Island Breast Cancer Study Project, a...promoter hypermethylation (presumably silencing) of the ER, PR, and BRCA1 genes . We will also examine whether functional polymorphisms in one- carbon

Relative Impact of Incorporating Pharmacokinetics on ...

EPA Pesticide Factsheets

The use of high-throughput in vitro assays has been proposed to play a significant role in the future of toxicity testing. In this study, rat hepatic metabolic clearance and plasma protein binding were measured for 59 ToxCast phase I chemicals. Computational in vitro-to-in vivo extrapolation was used to estimate the daily dose in a rat, called the oral equivalent dose, which would result in steady-state in vivo blood concentrations equivalent to the AC50 or lowest effective concentration (LEC) across more than 600 ToxCast phase I in vitro assays. Statistical classification analysis was performed using either oral equivalent doses or unadjusted AC50/LEC values for the in vitro assays to predict the in vivo effects of the 59 chemicals. Adjusting the in vitro assays for pharmacokinetics did not improve the ability to predict in vivo effects as either a discrete (yes or no) response or a low effect level (LEL) on a continuous dose scale. Interestingly, a comparison of the in vitro assay with the lowest oral equivalent dose with the in vivo endpoint with the lowest LEL suggested that the lowest oral equivalent dose may provide a conservative estimate of the point of departure for a chemical in a dose-response assessment. Furthermore, comparing the oral equivalent doses for the in vitro assays with the in vivo dose range that resulted in adverse effects identified more coincident in vitro assays across chemicals than expected by chance, suggesting that the approach ma

The application of robotics to microlaryngeal laser surgery.

PubMed

Buckmire, Robert A; Wong, Yu-Tung; Deal, Allison M

2015-06-01

To evaluate the performance of human subjects, using a prototype robotic micromanipulator controller in a simulated, microlaryngeal operative setting. Observational cross-sectional study. Twenty-two human subjects with varying degrees of laser experience performed CO2 laser surgical tasks within a simulated microlaryngeal operative setting using an industry standard manual micromanipulator (MMM) and a prototype robotic micromanipulator controller (RMC). Accuracy, repeatability, and ablation consistency measures were obtained for each human subject across both conditions and for the preprogrammed RMC device. Using the standard MMM, surgeons with >10 previous laser cases performed superior to subjects with fewer cases on measures of error percentage and cumulative error (P = .045 and .03, respectively). No significant differences in performance were observed between subjects using the RMC device. In the programmed (P/A) mode, the RMC performed equivalently or superiorly to experienced human subjects on accuracy and repeatability measures, and nearly an order of magnitude better on measures of ablation consistency. The programmed RMC performed significantly better for repetition error when compared to human subjects with <100 previous laser cases (P = .04). Experienced laser surgeons perform better than novice surgeons on tasks of accuracy and repeatability using the MMM device but roughly equivalently using the novel RMC. Operated in the P/A mode, the RMC performs equivalently or superior to experienced laser surgeons using the industry standard MMM for all measured parameters, and delivers an ablation consistency nearly an order of magnitude better than human laser operators. NA. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

The uncertain response in humans and animals

NASA Technical Reports Server (NTRS)

Smith, J. D.; Shields, W. E.; Schull, J.; Washburn, D. A.; Rumbaugh, D. M. (Principal Investigator)

1997-01-01

There has been no comparative psychological study of uncertainty processes. Accordingly, the present experiments asked whether animals, like humans, escape adaptively when they are uncertain. Human and animal observers were given two primary responses in a visual discrimination task, and the opportunity to escape from some trials into easier ones. In one psychophysical task (using a threshold paradigm), humans escaped selectively the difficult trials that left them uncertain of the stimulus. Two rhesus monkeys (Macaca mulatta) also showed this pattern. In a second psychophysical task (using the method of constant stimuli), some humans showed this pattern but one escaped infrequently and nonoptimally. Monkeys showed equivalent individual differences. The data suggest that escapes by humans and monkeys are interesting cognitive analogs and may reflect controlled decisional processes prompted by the perceptual ambiguity at threshold.

Chronic intake of honey, sugar and high fructose corn syrup exert equivalent effects on glucose and insulin

USDA-ARS?s Scientific Manuscript database

Consumption of nutritive sweeteners is high with ‘added sugars’ intake from the WWEIA (2009-2010) survey in all individuals = 2 yr at 76.2 g or 295 kcal daily. Controversy continues regarding the metabolic effects of the source of sweetener. Our goal was to evaluate the glycemic and insulin effect o...

Clinical correlation between the 6-min walk test andcardiopulmonary exercise testing in patients with pulmonary arterial hypertension.

PubMed

Acar, Serap; Savcı, Sema; Kardibak, Didem; Özcan Kahraman, Buse; Akdeniz, Bahri; Özpelit, Ebru; Sevinç, Can

2016-12-20

The aims of the present study were to assess the relationship between the distance walked during the 6-min walk test (6MWT) and exercise capacity as determined by cardiopulmonary exercise testing (CPET) in patients with pulmonary arterial hypertension (PAH) and to investigate the prognostic value of the 6MWT in comparison to clinical parameters of CPET and echocardiography findings. Thirty PAH patients participated in the study. Subject characteristics and New York Heart Association (NYHA) classifications were recorded. All subjects completed the 6MWT and CPET. Relationships among the variables were analyzed by the Pearson correlation test. Correlation coefficients between 6MWT distance and other variables were determined by linear regression analysis. Distance walked in the 6MWT was significantly correlated with the following exercise parameters: peak oxygen consumption, work load, and metabolic equivalents. Additionally, cardiac index was correlated with peak oxygen consumption and metabolic equivalents. We also showed that cardiac index and age were two significant determinants for exercise performance, accounting for 35.4% of the variance in the 6MWT. The 6MWT provides information that may be a better index for the patient's NYHA functional class determination than maximal exercise testing.

Metabolic Equivalent Determination in the Cultural Dance of Hula

PubMed Central

Usagawa, T.; Look, M.; de Silva, M.; Stickley, C.; Kaholokula, J. K.; Seto, T.; Mau, M.

2014-01-01

Ethnic minorities share an unequal burden of cardiometabolic syndrome. Physical activity (PA) has been shown as an important factor to improve the health outcomes of these diseases. Metabolic equivalents (METs) have been calculated for diverse activities; however, most cultural activities have not been evaluated. Hula, the traditional dance of Native Hawaiians, is practiced by men and women of all ages but its MET value is unknown. To our knowledge, this is the first scientific evaluation of energy expenditure of hula. Nineteen competitive hula dancers performed two dance sets of low and high intensity hula. METs were measured with a portable indirect calorimetry device. Mean and standard deviations were calculated for all the variables. A two-way ANOVA was conducted to identify differences for gender and intensity. The mean MET were 5.7 (range 3.17 – 9.77) and 7.55 (range 4.43 – 12.0) for low intensity and high intensity, respectively. There was a significant difference between intensities and no significant difference between genders. This study demonstrates the energy expenditure of both low and high intensity hula met the recommended guidelines for moderate and vigorous intensity exercise, respectively and that hula can be utilized as a prescribed PA. PMID:24203801

Choose, rate or squeeze: Comparison of economic value functions elicited by different behavioral tasks

PubMed Central

Pessiglione, Mathias

2017-01-01

A standard view in neuroeconomics is that to make a choice, an agent first assigns subjective values to available options, and then compares them to select the best. In choice tasks, these cardinal values are typically inferred from the preference expressed by subjects between options presented in pairs. Alternatively, cardinal values can be directly elicited by asking subjects to place a cursor on an analog scale (rating task) or to exert a force on a power grip (effort task). These tasks can vary in many respects: they can notably be more or less costly and consequential. Here, we compared the value functions elicited by choice, rating and effort tasks on options composed of two monetary amounts: one for the subject (gain) and one for a charity (donation). Bayesian model selection showed that despite important differences between the three tasks, they all elicited a same value function, with similar weighting of gain and donation, but variable concavity. Moreover, value functions elicited by the different tasks could predict choices with equivalent accuracy. Our finding therefore suggests that comparable value functions can account for various motivated behaviors, beyond economic choice. Nevertheless, we report slight differences in the computational efficiency of parameter estimation that may guide the design of future studies. PMID:29161252

Stimulus Equivalence, Generalization, and Contextual Stimulus Control in Verbal Classes

PubMed Central

Sigurðardóttir, Zuilma Gabriela; Mackay, Harry A; Green, Gina

2012-01-01

Stimulus generalization and contextual control affect the development of equivalence classes. Experiment 1 demonstrated primary stimulus generalization from the members of trained equivalence classes. Adults were taught to match six spoken Icelandic nouns and corresponding printed words and pictures to one another in computerized three-choice matching-to-sample tasks. Tests confirmed that six equivalence classes had formed. Without further training, plural forms of the stimuli were presented in tests for all matching performances. All participants demonstrated virtually errorless performances. In Experiment 2, classifications of the nouns used in Experiment 1 were brought under contextual control. Three nouns were feminine and three were masculine. The match-to-sample training taught participants to select a comparison of the same number as the sample (i.e., singular or plural) in the presence of contextual stimulus A regardless of noun gender. Concurrently, in the presence of contextual stimulus B, participants were taught to select a comparison of the same gender as the sample (i.e., feminine or masculine), regardless of number. Generalization was assessed using a card-sorting test. All participants eventually sorted the cards correctly into gender and number stimulus classes. When printed words used in training were replaced by their picture equivalents, participants demonstrated almost errorless performances. PMID:22754102

The genome sequence of Geobacter metallireducens: features of metabolism, physiology and regulation common and dissimilar to Geobacter sulfurreducens

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

Aklujkar, Muktak; Krushkal, Julia; DiBartolo, Genevieve

Background. The genome sequence of Geobacter metallireducens is the second to be completed from the metal-respiring genus Geobacter, and is compared in this report to that of Geobacter sulfurreducens in order to understand their metabolic, physiological and regulatory similarities and differences. Results. The experimentally observed greater metabolic versatility of G. metallireducens versus G. sulfurreducens is borne out by the presence of more numerous genes for metabolism of organic acids including acetate, propionate, and pyruvate. Although G. metallireducens lacks a dicarboxylic acid transporter, it has acquired a second succinate dehydrogenase/fumarate reductase complex, suggesting that respiration of fumarate was important until recentlymore » in its evolutionary history. Vestiges of the molybdate (ModE) regulon of G. sulfurreducens can be detected in G. metallireducens, which has lost the global regulatory protein ModE but retained some putative ModE-binding sites and multiplied certain genes of molybdenum cofactor biosynthesis. Several enzymes of amino acid metabolism are of different origin in the two species, but significant patterns of gene organization are conserved. Whereas most Geobacteraceae are predicted to obtain biosynthetic reducing equivalents from electron transfer pathways via a ferredoxin oxidoreductase, G. metallireducens can derive them from the oxidative pentose phosphate pathway. In addition to the evidence of greater metabolic versatility, the G. metallireducens genome is also remarkable for the abundance of multicopy nucleotide sequences found in intergenic regions and even within genes. Conclusion. The genomic evidence suggests that metabolism, physiology Background. The genome sequence of Geobacter metallireducens is the second to be completed from the metal-respiring genus Geobacter, and is compared in this report to that of Geobacter sulfurreducens in order to understand their metabolic, physiological and regulatory similarities and differences. Results. The experimentally observed greater metabolic versatility of G. metallireducens versus G. sulfurreducens is borne out by the presence of more numerous genes for metabolism of organic acids including acetate, propionate, and pyruvate. Although G. metallireducens lacks a dicarboxylic acid transporter, it has acquired a second succinate dehydrogenase/fumarate reductase complex, suggesting that respiration of fumarate was important until recently in its evolutionary history. Vestiges of the molybdate (ModE) regulon of G. sulfurreducens can be detected in G. metallireducens, which has lost the global regulatory protein ModE but retained some putative ModE-binding sites and multiplied certain genes of molybdenum cofactor biosynthesis. Several enzymes of amino acid metabolism are of different origin in the two species, but significant patterns of gene organization are conserved. Whereas most Geobacteraceae are predicted to obtain biosynthetic reducing equivalents from electron transfer pathways via a ferredoxin oxidoreductase, G. metallireducens can derive them from the oxidative pentose phosphate pathway. In addition to the evidence of greater metabolic versatility, the G. metallireducens genome is also remarkable for the abundance of multicopy nucleotide sequences found in intergenic regions and even within genes. Conclusion. The genomic evidence suggests that metabolism, physiology and regulation of gene expression in G. metallireducens may be dramatically different from other Geobacteraceae.« less

Leisure-time exercise, physical activity during work and commuting, and risk of metabolic syndrome.

PubMed

Kuwahara, Keisuke; Honda, Toru; Nakagawa, Tohru; Yamamoto, Shuichiro; Akter, Shamima; Hayashi, Takeshi; Mizoue, Tetsuya

2016-09-01

Data are limited regarding effect of intensity of leisure-time physical activity on metabolic syndrome. Furthermore, no prospective data are available regarding effect of occupational and commuting physical activity on metabolic syndrome. We compared metabolic syndrome risk by intensity level of leisure-time exercise and by occupational and commuting physical activity in Japanese workers. We followed 22,383 participants, aged 30-64 years, without metabolic syndrome until 2014 March (maximum, 5 years of follow-up). Physical activity was self-reported. Metabolic syndrome was defined by the Joint Statement criteria. We used Cox regression models to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of metabolic syndrome. During a mean follow-up of 4.1 years, 5361 workers developed metabolic syndrome. After adjustment for covariates, compared with engaging in no exercise, the HRs (95 % CIs) for <7.5, 7.5 to <16.5, and ≥16.5 metabolic equivalent hours of exercise per week were 0.99 (0.90, 1.08), 0.99 (0.90, 1.10), and 0.95 (0.83, 1.08), respectively, among individuals engaging in moderate-intensity exercise alone; 0.93 (0.75, 1.14), 0.81 (0.64, 1.02), and 0.84 (0.66, 1.06), among individuals engaging in vigorous-intensity exercise alone; and 0.90 (0.70, 1.17), 0.74 (0.62, 0.89), and 0.81 (0.69, 0.96) among individuals engaging in the two intensities. Higher occupational physical activity was weakly but significantly associated with lower risk of metabolic syndrome. Walking to and from work was not associated with metabolic syndrome. Vigorous-intensity exercise alone or vigorous-intensity combined with moderate-intensity exercise and worksite intervention for physical activity may help prevent metabolic syndrome for Japanese workers.

Benefits of Stimulus Exposure: Developmental Learning Independent of Task Performance

PubMed Central

Green, David B.; Ohlemacher, Jocelyn; Rosen, Merri J.

2016-01-01

Perceptual learning (training-induced performance improvement) can be elicited by task-irrelevant stimulus exposure in humans. In contrast, task-irrelevant stimulus exposure in animals typically disrupts perception in juveniles while causing little to no effect in adults. This may be due to the extent of exposure, which is brief in humans while chronic in animals. Here we assessed the effects of short bouts of passive stimulus exposure on learning during development in gerbils, compared with non-passive stimulus exposure (i.e., during testing). We used prepulse inhibition of the acoustic startle response, a method that can be applied at any age, to measure gap detection thresholds across four age groups, spanning development. First, we showed that both gap detection thresholds and gap detection learning across sessions displayed a long developmental trajectory, improving throughout the juvenile period. Additionally, we demonstrated larger within- and across-animal performance variability in younger animals. These results are generally consistent with results in humans, where there are extended developmental trajectories for both the perception of temporally-varying signals, and the effects of perceptual training, as well as increased variability and poorer performance consistency in children. We then chose an age (mid-juveniles) that displayed clear learning over sessions in order to assess effects of brief passive stimulus exposure on this learning. We compared learning in mid-juveniles exposed to either gap detection testing (gaps paired with startles) or equivalent gap exposure without testing (gaps alone) for three sessions. Learning was equivalent in both these groups and better than both naïve age-matched animals and controls receiving no gap exposure but only startle testing. Thus, short bouts of exposure to gaps independent of task performance is sufficient to induce learning at this age, and is as effective as gap detection testing. PMID:27378837

Effects of select and reject control on equivalence class formation and transfer of function.

PubMed

Perez, William F; Tomanari, Gerson Y; Vaidya, Manish

2015-09-01

The present study used a single-subject design to evaluate the effects of select or reject control on equivalence class formation and transfer of function. Adults were exposed to a matching-to-sample task with observing requirements (MTS-OR) in order to bias the establishment of sample/S+ (select) or sample/S- (reject) relations. In Experiment 1, four sets of baseline conditional relations were taught-two under reject control (A1B2C1, A2B1C2) and two under select control (D1E1F1, D2E2F2). Participants were tested for transitivity, symmetry, equivalence and reflexivity. They also learned a simple discrimination involving one of the stimuli from the equivalence classes and were tested for the transfer of the discriminative function. In general, participants performed with high accuracy on all equivalence-related probes as well as the transfer of function probes under select control. Under reject control, participants had high scores only on the symmetry test; transfer of function was attributed to stimuli programmed as S-. In Experiment 2, the equivalence class under reject control was expanded to four members (A1B2C1D2; A2B1C2D1). Participants had high scores only on symmetry and on transitivity and equivalence tests involving two nodes. Transfer of function was extended to the programmed S- added to each class. Results from both experiments suggest that select and reject controls might differently affect the formation of equivalence classes and the transfer of stimulus functions. © Society for the Experimental Analysis of Behavior.

Load type influences motor unit recruitment in biceps brachii during a sustained contraction.

PubMed

Baudry, Stéphane; Rudroff, Thorsten; Pierpoint, Lauren A; Enoka, Roger M

2009-09-01

Twenty subjects participated in four experiments designed to compare time to task failure and motor-unit recruitment threshold during contractions sustained at 15% of maximum as the elbow flexor muscles either supported an inertial load (position task) or exerted an equivalent constant torque against a rigid restraint (force task). Subcutaneous branched bipolar electrodes were used to record single motor unit activity from the biceps brachii muscle during ramp contractions performed before and at 50 and 90% of the time to failure for the position task during both fatiguing contractions. The time to task failure was briefer for the position task than for the force task (P=0.0002). Thirty and 29 motor units were isolated during the force and position tasks, respectively. The recruitment threshold declined by 48 and 30% (P=0.0001) during the position task for motor units with an initial recruitment threshold below and above the target force, respectively, whereas no significant change in recruitment threshold was observed during the force task. Changes in recruitment threshold were associated with a decrease in the mean discharge rate (-16%), an increase in discharge rate variability (+40%), and a prolongation of the first two interspike intervals (+29 and +13%). These data indicate that there were faster changes in motor unit recruitment and rate coding during the position task than the force task despite a similar net muscle torque during both tasks. Moreover, the results suggest that the differential synaptic input observed during the position task influences most of the motor unit pool.

'Trophic' and 'source' amino acids in trophic estimation: a likely metabolic explanation.

PubMed

O'Connell, T C

2017-06-01

Amino acid nitrogen isotopic analysis is a relatively new method for estimating trophic position. It uses the isotopic difference between an individual's 'trophic' and 'source' amino acids to determine its trophic position. So far, there is no accepted explanation for the mechanism by which the isotopic signals in 'trophic' and 'source' amino acids arise. Yet without a metabolic understanding, the utility of nitrogen isotopic analyses as a method for probing trophic relations, at either bulk tissue or amino acid level, is limited. I draw on isotopic tracer studies of protein metabolism, together with a consideration of amino acid metabolic pathways, to suggest that the 'trophic'/'source' groupings have a fundamental metabolic origin, to do with the cycling of amino-nitrogen between amino acids. 'Trophic' amino acids are those whose amino-nitrogens are interchangeable, part of a metabolic amino-nitrogen pool, and 'source' amino acids are those whose amino-nitrogens are not interchangeable with the metabolic pool. Nitrogen isotopic values of 'trophic' amino acids will reflect an averaged isotopic signal of all such dietary amino acids, offset by the integrated effect of isotopic fractionation from nitrogen cycling, and modulated by metabolic and physiological effects. Isotopic values of 'source' amino acids will be more closely linked to those of equivalent dietary amino acids, but also modulated by metabolism and physiology. The complexity of nitrogen cycling suggests that a single identifiable value for 'trophic discrimination factors' is unlikely to exist. Greater consideration of physiology and metabolism should help in better understanding observed patterns in nitrogen isotopic values.

Metabolic costs of daily activity in older adults (Chores XL) study: design and methods.

PubMed

Corbett, Duane B; Wanigatunga, Amal A; Valiani, Vincenzo; Handberg, Eileen M; Buford, Thomas W; Brumback, Babette; Casanova, Ramon; Janelle, Christopher M; Manini, Todd M

2017-06-01

For over 20 years, normative data has guided the prescription of physical activity. This data has since been applied to research and used to plan interventions. While this data seemingly provides accurate estimates of the metabolic cost of daily activities in young adults, the accuracy of use among older adults is less clear. As such, a thorough evaluation of the metabolic cost of daily activities in community dwelling adults across the lifespan is needed. The Metabolic Costs of Daily Activity in Older Adults Study is a cross-sectional study designed to compare the metabolic cost of daily activities in 250 community dwelling adults across the lifespan. Participants (20+ years) performed 38 common daily activities while expiratory gases were measured using a portable indirect calorimeter (Cosmed K4b2). The metabolic cost was examined as a metabolic equivalent value (O 2 uptake relative to 3.5 milliliter• min-1•kg-1), a function of work rate - metabolic economy, and a relative value of resting and peak oxygen uptake. The primary objective is to determine age-related differences in the metabolic cost of common lifestyle and exercise activities. Secondary objectives include (a) investigating the effect of functional impairment on the metabolic cost of daily activities, (b) evaluating the validity of perception-based measurement of exertion across the lifespan, and (c) validating activity sensors for estimating the type and intensity of physical activity. Results of this study are expected to improve the effectiveness by which physical activity and nutrition is recommended for adults across the lifespan.

Symbolic and Nonsymbolic Equivalence Tasks: The Influence of Symbols on Students with Mathematics Difficulty

ERIC Educational Resources Information Center

Driver, Melissa K.; Powell, Sarah R.

2015-01-01

Students often experience difficulty with attaching meaning to mathematics symbols. Many students react to symbols, such as the equal sign, as a command to "do something" or "write an answer" without reflecting upon the proper relational meaning of the equal sign. One method for assessing equal-sign understanding is through…

The Hard but Necessary Task of Gathering Order-One Effect Size Indices in Meta-Analysis

ERIC Educational Resources Information Center

Ortego, Carmen; Botella, Juan

2010-01-01

Meta-analysis of studies with two groups and two measurement occasions must employ order-one effect size indices to represent study outcomes. Especially with non-random assignment, non-equivalent control group designs, a statistical analysis restricted to post-treatment scores can lead to severely biased conclusions. The 109 primary studies…

Social Comparison and Confidence: When Thinking You're Better than Average Predicts Overconfidence (And when It Does Not)

ERIC Educational Resources Information Center

Larrick, Richard P.; Burson, Katherine A.; Soll, Jack B.

2007-01-01

A common social comparison bias--the better-than-average-effect--is frequently described as psychologically equivalent to the individual-level judgment bias known as overconfidence. However, research has found "Hard-easy" effects for each bias that yield a seemingly paradoxical reversal: Hard tasks tend to produce overconfidence but…

Conditional Discriminations by Preverbal Children in an Identity Matching-to-Sample Task

ERIC Educational Resources Information Center

de Alcantara Gil, Maria Stella C.; de Oliveira, Thais Porlan; McIlvane, William J.

2011-01-01

This study sought to develop methodology for assessing whether children ages 16-21 months could learn to match stimuli on the basis of physical identity in conditional discrimination procedures routinely used in stimulus equivalence research with older participants. The study was conducted in a private room at a day-care center for children and…

Memory for Pictorial Information and the Picture Superiority Effect.

ERIC Educational Resources Information Center

Maisto, Albert A.; Queen, Debbie Elaine

1992-01-01

The performance of 53 younger adults (mean age 20.7) and 52 older adults (mean age 68.3) was compared in a memory task involving pictures, words, and pictures-plus-words. Results showed (1) significantly higher recall scores for younger adults; (2) equivalent picture superiority effect for both groups; and (3) decline in older adults' performance…

Effects of Story Mapping on Third-Grade Students with Attention Deficit Hyperactivity Disorder

ERIC Educational Resources Information Center

Chavez, Jaime N.; Martinez, James; Pienta, Rachel S.

2015-01-01

The purpose of this study was to examine the effects of story mapping on the reading comprehension scores, on-task behaviors, and attitudes of third- -grade students (N = 6) with ADHD. Students' reading grade equivalencies were assessed before and after the study. The teacher-researcher compared two other achievement measures before and during…

A survey of the state of the art and focused research in range systems, task 2

NASA Technical Reports Server (NTRS)

Yao, K.

1986-01-01

Contract generated publications are compiled which describe the research activities for the reporting period. Study topics include: equivalent configurations of systolic arrays; least squares estimation algorithms with systolic array architectures; modeling and equilization of nonlinear bandlimited satellite channels; and least squares estimation and Kalman filtering by systolic arrays.

Concurrent Correlates and Predictors of Reading and Spelling Achievement in Deaf and Hearing School Children

ERIC Educational Resources Information Center

Kyle, Fiona E.; Harris, Margaret

2006-01-01

Seven-and eight-year-old deaf children and hearing children of equivalent reading age were presented with a number of tasks designed to assess reading, spelling, productive vocabulary, speechreading, phonological awareness, short-term memory, and nonverbal intelligence. The two groups were compared for similarities and differences in the levels of…

Changes in mixed-function oxidase system in the perfused liver of the cold-acclimated rat

NASA Astrophysics Data System (ADS)

Takano, T.; Miyazaki, Y.; Motohashi, Y.; Yamada, K.

1986-09-01

Changes in the hepatic cytochrome P-450-dependent drug-metabolizing system were studied in perfused livers obtained from cold-acclimated male Wistar rats after 30 days of cold exposure (4‡C) when using hexobarbital as a substrate. In fasted animals the cold-acclimated rats showed higher levels of hexobarbital metabolic rates compared to control rats, but there was no significant difference in fed animals. The maximum rates of hexobarbital metabolism produced by xylitol perfusion were also significantly higher in the perfused liver of cold-acclimated rats. It was concluded that the function of the cytochrome P-450 system for hexobarbital in cold-acclimated rats changed due to both an increase in the activity of the cytochrome P-450 system and to changes in regulation of the cytochrome P-450 system by the supply of reducing equivalents.

Predicting yields for autotrophic and cometabolic processes

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

Andrews, G.

1995-12-31

The goal of bioprocess engineering is to state how the optimum design and control strategy for a bioprocess follow from the metabolism of the particular microorganism. A necessary step toward this goal is to show how the parameters used in quantitative descriptions of a process (e.g., yield and maintenance coefficients) are related to those describing the metabolism [e.g., Y{sub ATP}, (P/O)]. The {open_quotes}yield equation{close_quotes} approach to this problem involves dividing metabolism into the separate pathways for catabolism, anabolism, respiration, and product formation and balancing the production and consumption of reducing equivalents and ATP. The general approach, demonstrated previously for heterotrophicmore » cell growth and products of fermentation, is illustrated by three new examples: the cell yield for chemoautotrophic iron-oxidizing bacteria, the cometabolic degradation of chloroform by methanotrophic bacteria, and the theoretical yield of succinic acid from glucose.« less

In High-Light-Acclimated Coffee Plants the Metabolic Machinery Is Adjusted to Avoid Oxidative Stress Rather than to Benefit from Extra Light Enhancement in Photosynthetic Yield

PubMed Central

Martins, Samuel C. V.; Araújo, Wagner L.; Tohge, Takayuki; Fernie, Alisdair R.; DaMatta, Fábio M.

2014-01-01

Coffee (Coffea arabica L.) has been traditionally considered as shade-demanding, although it performs well without shade and even out-yields shaded coffee. Here we investigated how coffee plants adjust their metabolic machinery to varying light supply and whether these adjustments are supported by a reprogramming of the primary and secondary metabolism. We demonstrate that coffee plants are able to adjust its metabolic machinery to high light conditions through marked increases in its antioxidant capacity associated with enhanced consumption of reducing equivalents. Photorespiration and alternative pathways are suggested to be key players in reductant-consumption under high light conditions. We also demonstrate that both primary and secondary metabolism undergo extensive reprogramming under high light supply, including depression of the levels of intermediates of the tricarboxylic acid cycle that were accompanied by an up-regulation of a range of amino acids, sugars and sugar alcohols, polyamines and flavonoids such as kaempferol and quercetin derivatives. When taken together, the entire dataset is consistent with these metabolic alterations being primarily associated with oxidative stress avoidance rather than representing adjustments in order to facilitate the plants from utilizing the additional light to improve their photosynthetic performance. PMID:24733284

Effect of stride frequency on metabolic costs and rating of perceived exertion during walking in water.

PubMed

Masumoto, Kenji; Nishizaki, Yoshiko; Hamada, Ayako

2013-06-01

We investigated the effect of stride frequency (SF) on metabolic costs and rating of perceived exertion (RPE) during walking in water and on dry land. Eleven male subjects walked on a treadmill on dry land and on an underwater treadmill at their preferred SF (PSF) and walked at an SF which was lower and higher than the PSF (i.e., PSF ± 5, 10, and 15 strides min(-1)). Walking speed was kept constant at each subject's preferred walking speed in water and on dry land. Oxygen uptake, heart rate, RPE, PSF and preferred walking speeds were measured. Metabolic costs and RPE were significantly higher when walking at low and high SF conditions than when walking at the PSF condition both in water and on dry land (P<0.05). Additionally, the high SF condition produced significantly higher metabolic costs and RPE than the equivalent low SF condition during walking in water (P<0.01). Furthermore, metabolic costs, RPE, PSF, and the preferred walking speed were significantly lower in water than on dry land when walking at the PSF (P<0.05). These observations indicate that a change in SF influences metabolic costs and RPE during walking in water. Copyright © 2012 Elsevier B.V. All rights reserved.

Global metabolic impacts of recent climate warming.

PubMed

Dillon, Michael E; Wang, George; Huey, Raymond B

2010-10-07

Documented shifts in geographical ranges, seasonal phenology, community interactions, genetics and extinctions have been attributed to recent global warming. Many such biotic shifts have been detected at mid- to high latitudes in the Northern Hemisphere-a latitudinal pattern that is expected because warming is fastest in these regions. In contrast, shifts in tropical regions are expected to be less marked because warming is less pronounced there. However, biotic impacts of warming are mediated through physiology, and metabolic rate, which is a fundamental measure of physiological activity and ecological impact, increases exponentially rather than linearly with temperature in ectotherms. Therefore, tropical ectotherms (with warm baseline temperatures) should experience larger absolute shifts in metabolic rate than the magnitude of tropical temperature change itself would suggest, but the impact of climate warming on metabolic rate has never been quantified on a global scale. Here we show that estimated changes in terrestrial metabolic rates in the tropics are large, are equivalent in magnitude to those in the north temperate-zone regions, and are in fact far greater than those in the Arctic, even though tropical temperature change has been relatively small. Because of temperature's nonlinear effects on metabolism, tropical organisms, which constitute much of Earth's biodiversity, should be profoundly affected by recent and projected climate warming.

Extracellular glucose can fuel metabolism in red blood cells from high glycemic Atlantic cod (Gadus morhua) but not low glycemic short-horned sculpin (Myoxocephalus scorpius).

PubMed

Driedzic, William R; Clow, Kathy A; Short, Connie E

2014-11-01

Energy metabolism was assessed in red blood cells (RBCs) from Atlantic cod and short-horned sculpin, two species that have markedly different levels of blood glucose. The objective was to determine whether the level of extracellular glucose has an impact on rates of glucose metabolism. The blood glucose level was 2.5 mmol l(-1) in Atlantic cod and 0.2 mmol l(-1) in short-horned sculpin, respectively. Oxygen consumption, lactate production and glucose utilization were measured in whole blood and related to grams of RBCs. Glucose utilization was assessed by measuring both glucose disappearance and the production of (3)H2O from [2-(3)H]-glucose. RBCs from both species have an aerobic-based metabolism. In Atlantic cod, extracellular glucose is sufficient to provide the sum of glucosyl equivalents to support both oxidative metabolism and lactate production. In contrast, extracellular glucose can account for only 10% of the metabolic rate in short-horned sculpin RBCs. In both species, about 70% of glucose enters the RBCs via facilitated transport. The difference in rates of extracellular glucose utilization is related to the extremely low levels of blood glucose in short-horned sculpin. In this species energy metabolism by RBCs must be supported by alternative fuels. © 2014. Published by The Company of Biologists Ltd.

Do you really represent my task? Sequential adaptation effects to unexpected events support referential coding for the joint Simon effect.

PubMed

Klempova, Bibiana; Liepelt, Roman

2016-07-01

Recent findings suggest that a Simon effect (SE) can be induced in Individual go/nogo tasks when responding next to an event-producing object salient enough to provide a reference for the spatial coding of one's own action. However, there is skepticism against referential coding for the joint Simon effect (JSE) by proponents of task co-representation. In the present study, we tested assumptions of task co-representation and referential coding by introducing unexpected double response events in a joint go/nogo and a joint independent go/nogo task. In Experiment 1b, we tested if task representations are functionally similar in joint and standard Simon tasks. In Experiment 2, we tested sequential updating of task co-representation after unexpected single response events in the joint independent go/nogo task. Results showed increased JSEs following unexpected events in the joint go/nogo and joint independent go/nogo task (Experiment 1a). While the former finding is in line with the assumptions made by both accounts (task co-representation and referential coding), the latter finding supports referential coding. In contrast to Experiment 1a, we found a decreased SE after unexpected events in the standard Simon task (Experiment 1b), providing evidence against the functional equivalence assumption between joint and two-choice Simon tasks of the task co-representation account. Finally, we found an increased JSE also following unexpected single response events (Experiment 2), ruling out that the findings of the joint independent go/nogo task in Experiment 1a were due to a re-conceptualization of the task situation. In conclusion, our findings support referential coding also for the joint Simon effect.

PathCase-SB architecture and database design

PubMed Central

2011-01-01

Background Integration of metabolic pathways resources and regulatory metabolic network models, and deploying new tools on the integrated platform can help perform more effective and more efficient systems biology research on understanding the regulation in metabolic networks. Therefore, the tasks of (a) integrating under a single database environment regulatory metabolic networks and existing models, and (b) building tools to help with modeling and analysis are desirable and intellectually challenging computational tasks. Description PathCase Systems Biology (PathCase-SB) is built and released. The PathCase-SB database provides data and API for multiple user interfaces and software tools. The current PathCase-SB system provides a database-enabled framework and web-based computational tools towards facilitating the development of kinetic models for biological systems. PathCase-SB aims to integrate data of selected biological data sources on the web (currently, BioModels database and KEGG), and to provide more powerful and/or new capabilities via the new web-based integrative framework. This paper describes architecture and database design issues encountered in PathCase-SB's design and implementation, and presents the current design of PathCase-SB's architecture and database. Conclusions PathCase-SB architecture and database provide a highly extensible and scalable environment with easy and fast (real-time) access to the data in the database. PathCase-SB itself is already being used by researchers across the world. PMID:22070889

Short- and medium-chain fatty acids in energy metabolism: the cellular perspective.

PubMed

Schönfeld, Peter; Wojtczak, Lech

2016-06-01

Short- and medium-chain fatty acids (SCFAs and MCFAs), independently of their cellular signaling functions, are important substrates of the energy metabolism and anabolic processes in mammals. SCFAs are mostly generated by colonic bacteria and are predominantly metabolized by enterocytes and liver, whereas MCFAs arise mostly from dietary triglycerides, among them milk and dairy products. A common feature of SCFAs and MCFAs is their carnitine-independent uptake and intramitochondrial activation to acyl-CoA thioesters. Contrary to long-chain fatty acids, the cellular metabolism of SCFAs and MCFAs depends to a lesser extent on fatty acid-binding proteins. SCFAs and MCFAs modulate tissue metabolism of carbohydrates and lipids, as manifested by a mostly inhibitory effect on glycolysis and stimulation of lipogenesis or gluconeogenesis. SCFAs and MCFAs exert no or only weak protonophoric and lytic activities in mitochondria and do not significantly impair the electron transport in the respiratory chain. SCFAs and MCFAs modulate mitochondrial energy production by two mechanisms: they provide reducing equivalents to the respiratory chain and partly decrease efficacy of oxidative ATP synthesis. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

The uptake, distribution, metabolism, and excretion of methyl tertiary-butyl ether inhaled alone and in combination with gasoline vapor.

PubMed

Benson, Janet M; Tibbetts, Brad M; Barr, Edward B

2003-06-13

The purpose of these studies was to evaluate the tissue uptake, distribution, metabolism, and excretion of methyl tertiary-butyl ether (MTBE) in rats and to determine the effects of coinhalation of the volatile fraction of unleaded gasoline on these parameters. Male F344 rats were exposed nose-only once for 4 h to 4, 40, or 400 ppm 14C-MTBE and to 20 and 200 ppm of the light fraction of unleaded gasoline (LFG) containing 4 and 40 ppm 14C-MTBE, respectively. To evaluate the effects of repeated inhalation of LFG on the fate of inhaled MTBE, rats were exposed for 7 consecutive days to 20 and 200 ppm LFG followed on d 8 by exposure to LFG containing 14C-MTBE. Three subgroups of rats were included for evaluation of respiratory parameters, rates and routes of excretion, and tissue distribution and elimination. MTBE and its chief metabolite, tertiary-butyl alcohol, were quantitated in blood and kidney (immediately after exposure), and the major urinary metabolites, 2-hydroxyisobutyric acid and 2-methyl-1,2- propanediol, were identified and quantified in urine. Inhalation of MTBE alone or as a component of LFG had no concentration-dependent effect on respiratory minute volume. The initial body burdens (IBBs) of MTBE equivalents achieved after 4 h of exposure to MTBE did not increase linearly with exposure concentration. MTBE equivalents rapidly distributed to all tissues examined, with the largest percentages distributed to liver. Between 40 and 400 ppm, there was a significant reduction in percentage of the IBB present in the major organs examined, both immediately and 72 h after exposure. At 400 ppm, the elimination rates of MTBE equivalents from tissues changed significantly. Furthermore, at 400 ppm there was a significant decrease in the elimination half-time of volatile organic compounds (VOCs) in breath and a significant increase in the percentage of the IBB of MTBE equivalents eliminated as VOCs in breath. LFG coexposure significantly decreased the percentage of the MTBE equivalent IBBs in tissues and increased rates of elimination of MTBE equivalents. The study results indicate that the uptake and fate of inhaled MTBE are altered upon increasing exposure levels from 4 to 400 ppm, suggesting that toxic effects observed previously upon repeated inhalation of concentrations of 400 ppm or greater may not necessarily be linearly extrapolated to effects that might occur at lower concentrations. Furthermore, coexposure to LFG, whether acute or repeated, decreases tissue burdens of MTBE equivalents and enhances the elimination rate of MTBE and its metabolites, thereby potentially reducing the toxic effects of the MTBE compared to when it is inhaled alone.

Complex systems in metabolic engineering.

PubMed

Winkler, James D; Erickson, Keesha; Choudhury, Alaksh; Halweg-Edwards, Andrea L; Gill, Ryan T

2015-12-01

Metabolic engineers manipulate intricate biological networks to build efficient biological machines. The inherent complexity of this task, derived from the extensive and often unknown interconnectivity between and within these networks, often prevents researchers from achieving desired performance. Other fields have developed methods to tackle the issue of complexity for their unique subset of engineering problems, but to date, there has not been extensive and comprehensive examination of how metabolic engineers use existing tools to ameliorate this effect on their own research projects. In this review, we examine how complexity affects engineering at the protein, pathway, and genome levels within an organism, and the tools for handling these issues to achieve high-performing strain designs. Quantitative complexity metrics and their applications to metabolic engineering versus traditional engineering fields are also discussed. We conclude by predicting how metabolic engineering practices may advance in light of an explicit consideration of design complexity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthetic metabolism: metabolic engineering meets enzyme design.

PubMed

Erb, Tobias J; Jones, Patrik R; Bar-Even, Arren

2017-04-01

Metabolic engineering aims at modifying the endogenous metabolic network of an organism to harness it for a useful biotechnological task, for example, production of a value-added compound. Several levels of metabolic engineering can be defined and are the topic of this review. Basic 'copy, paste and fine-tuning' approaches are limited to the structure of naturally existing pathways. 'Mix and match' approaches freely recombine the repertoire of existing enzymes to create synthetic metabolic networks that are able to outcompete naturally evolved pathways or redirect flux toward non-natural products. The space of possible metabolic solution can be further increased through approaches including 'new enzyme reactions', which are engineered on the basis of known enzyme mechanisms. Finally, by considering completely 'novel enzyme chemistries' with de novo enzyme design, the limits of nature can be breached to derive the most advanced form of synthetic pathways. We discuss the challenges and promises associated with these different metabolic engineering approaches and illuminate how enzyme engineering is expected to take a prime role in synthetic metabolic engineering for biotechnology, chemical industry and agriculture of the future. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Metabolic pathways in T cell activation and lineage differentiation.

PubMed

Almeida, Luís; Lochner, Matthias; Berod, Luciana; Sparwasser, Tim

2016-10-01

Recent advances in the field of immunometabolism support the concept that fundamental processes in T cell biology, such as TCR-mediated activation and T helper lineage differentiation, are closely linked to changes in the cellular metabolic programs. Although the major task of the intermediate metabolism is to provide the cell with a constant supply of energy and molecular precursors for the production of biomolecules, the dynamic regulation of metabolic pathways also plays an active role in shaping T cell responses. Key metabolic processes such as glycolysis, fatty acid and mitochondrial metabolism are now recognized as crucial players in T cell activation and differentiation, and their modulation can differentially affect the development of T helper cell lineages. In this review, we describe the diverse metabolic processes that T cells engage during their life cycle from naïve towards effector and memory T cells. We consider in particular how the cellular metabolism may actively support the function of T cells in their different states. Moreover, we discuss how molecular regulators such as mTOR or AMPK link environmental changes to adaptations in the cellular metabolism and elucidate the consequences on T cell differentiation and function. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

[18F]-FDG positron emission tomography--an established clinical tool opening a new window into exercise physiology.

PubMed

Rudroff, Thorsten; Kindred, John H; Kalliokoski, Kari K

2015-05-15

Positron emission tomography (PET) with [(18)F]-fluorodeoxyglucose (FDG) is an established clinical tool primarily used to diagnose and evaluate disease status in patients with cancer. PET imaging using FDG can be a highly valuable tool to investigate normal human physiology by providing a noninvasive, quantitative measure of glucose uptake into various cell types. Over the past years it has also been increasingly used in exercise physiology studies to identify changes in glucose uptake, metabolism, and muscle activity during different exercise modalities. Metabolically active cells transport FDG, an (18)fluorine-labeled glucose analog tracer, from the blood into the cells where it is then phosphorylated but not further metabolized. This metabolic trapping process forms the basis of this method's use during exercise. The tracer is given to a participant during an exercise task, and the actual PET imaging is performed immediately after the exercise. Provided the uptake period is of sufficient duration, and the imaging is performed shortly after the exercise; the captured image strongly reflects the metabolic activity of the cells used during the task. When combined with repeated blood sampling to determine tracer blood concentration over time, also known as the input function, glucose uptake rate of the tissues can be quantitatively calculated. This synthesis provides an accounting of studies using FDG-PET to measure acute exercise-induced skeletal muscle activity, describes the advantages and limitations of this imaging technique, and discusses its applications to the field of exercise physiology. Copyright © 2015 the American Physiological Society.

Associations between micronutrient intakes and gut microbiota in a group of adults with cystic fibrosis.

PubMed

Li, Li; Krause, Lutz; Somerset, Shawn

2017-08-01

Cystic fibrosis (CF) involves chronic inflammation and oxidative stress affecting mainly the respiratory and digestive systems. Survival rates for CF have improved with advances in treatment including nutritional interventions such as micronutrient supplementation. Diet can modulate gut microbiota in the general population with consequences on local and systemic immunity, and inflammation. The gut microbiota appears disrupted and may associate with pulmonary status in CF. This study investigated associations between micronutrient intakes and gut microbiota variations in a group of adults with CF. Faecal microbiota of sixteen free-living adults with CF was profiled by 16ss rDNA sequencing on the GS-FLX platform. Associations were tested between UniFrac distances of faecal microbiota and time-corresponding micronutrient intakes. Associations between relative abundances of bacterial taxa and micronutrient intakes (those showing significant associations with UniFrac distances) were examined by Spearman correlation. Unweighted UniFrac distances were associated with intakes of potassium and antioxidant vitamins C, E and beta-carotene equivalents, whereas weighted UniFrac distances were associated with antioxidant vitamins riboflavin, niacin equivalents, beta-carotene equivalents and vitamin A equivalents. Intakes of beta-carotene equivalents, vitamin C, vitamin E, niacin equivalents and riboflavin correlated negatively with Bacteroides and/or its corresponding higher level taxa. Intakes of beta-carotene equivalents and vitamin E also positively correlated with Firmicutes and specific taxa belonging to Firmicutes. Some micronutrients, particularly antioxidant vitamins, correlated with gut microbiota variations in the studied cohort. Further research is required to clarify whether antioxidant vitamin intakes can influence CF gut microbiota and potential clinical/therapeutic implications in CF. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Analysis of fish bile with HPLC — fluorescence to determine environmental exposure to benzo(a)pyrene

USGS Publications Warehouse

Johnston, Eric P.; Baumann, Paul C.

1989-01-01

Brown bullhead from the Black River, Ohio, have a high incidence of liver neoplasia which is associated with elevated concentrations of polynuclear aromatic hydrocarbons (PAHs) in the sediment. We evaluated the use of biliary concentrations of benzo(a)pyrene [B(a)P] equivalents as a means for determining PAH exposure. Bile was collected from 16 brown bullheads and 8 common carp taken from each of two Lake Erie tributaries in Ohio, the industrialized Black River and the non-industrialized Old Woman Creek. Hatchery bullhead (n = 8) were used to determine base levels of PAHs. A high performance liquid chromatography (HPLC) — fluorescence technique was used to determine the concentration of B(a)P equivalents in the bile samples. The area of all peaks fluorescing at 380/430 nm was summed to give a single value for B(a)P equivalents in each sample. Concentrations of B(a)P equivalents generally reflected concentrations of PAH in sediment where fish were collected. Bile taken from Black River carp contained the highest concentration of B(a)P equivalents and was significantly different from all other groups. The value obtained for Black River bullhead was also high and was found to be significantly different from hatchery bullhead. B(a)P equivalents varied between carp and bullhead from the same habitat possibly because of differing food habits or metabolic pathways. However, our results indicate that relative levels of B(a)P equivalents in the bile of fish correspond well to B(a)P levels in sediment and may offer a means of determining environmental exposure of fish to the parent compound.

Explicit memory and implicit memory in occipital lobe stroke patients.

PubMed

Gong, Liang; Wang, JiHua; Feng, Lei; Wang, MeiHong; Li, Xiu; Hu, JiaYun; Wang, Kai

2015-03-01

Occipital stroke patients mainly showed cortical blindness and unilateral vision loss; memory is generally reserved. Recent reports from neuroimaging show the occipital lobe may be involved in the processing of implicit memory (IM), especially the perception type of IM processing. In this study, we explored the explicit memory (EM) and IM damage in occipital lobe stroke patients. A total of 25 occipital strokes and 29 years of age, educational level equivalent healthy controls (HCs), evaluated by using immediate recall, delayed recall, recognition for EM tasks, picture identification, and category exemplar generation for IM tasks. There was no significant difference between occipital stroke patients and HCs in EM tasks and category exemplar generation task. In the picture identification task, occipital lobe stroke group score was poorer than HC group, the results were statistically significant, but in the pictures identify rate, occipital stroke patients and normal control group had no significant difference. The occipital stroke patients may have IM damage, primarily damage the perception type of IM priming effects, which was unrelated with their cortical blindness. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

The economic production of alcohol fuels from coal-derived synthesis gas

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

Kugler, E.L.; Dadyburjor, D.B.; Yang, R.Y.K.

1995-12-31

The objectives of this project are to discover, (1) study and evaluate novel heterogeneous catalytic systems for the production of oxygenated fuel enhancers from synthesis gas. Specifically, alternative methods of preparing catalysts are to be investigated, and novel catalysts, including sulfur-tolerant ones, are to be pursued. (Task 1); (2) explore, analytically and on the bench scale, novel reactor and process concepts for use in converting syngas to liquid fuel products. (Task 1); (3) simulate by computer the most energy efficient and economically efficient process for converting coal to energy, with primary focus on converting syngas to fuel alcohols. (Task 2);more » (4) develop on the bench scale the best holistic combination of chemistry, catalyst, reactor and total process configuration integrated with the overall coal conversion process to achieve economic optimization for the conversion of syngas to liquid products within the framework of achieving the maximum cost effective transformation of coal to energy equivalents. (Tasks 1 and 2); and (5) evaluate the combustion, emission and performance characteristics of fuel alcohols and blends of alcohols with petroleum-based fuels. (Task 2)« less

Inhibiting reactions to emotional versus non-emotional response cues in schizophrenia: Insights from a motor-process paradigm.

PubMed

Patrick, Regan E; Christensen, Bruce K; Smolewska, Kathy

2016-03-01

Recent models of schizophrenia suggest deficient use of contextual response cues when confronted with countermanding emotional cues. It is important to clinically validate these models by testing patients diagnosed with schizophrenia on tasks with competing emotional and contextual response determinants. Control and schizophrenia groups completed a novel task that elicited motor responses consistent with, or in opposition to, pre-potent emotional actions (i.e., approach vs. avoidance). An analogous non-emotional task was also used to examine cue-conflict impairment more generally. The groups demonstrated statistically equivalent performance decrements on incongruent versus congruent trials on both tasks. However, within the schizophrenia group, the incongruency effect was significantly greater in the emotional versus non-emotional task. These data suggest that, while patients with schizophrenia were able to employ contextual response cues to override competing emotional responses, they were slower to resolve emotional versus non-emotional response conflict. When patients were subdivided according to the presence or absence of disorganized symptoms, this effect was confined to patients with disorganized symptoms. © 2014 The British Psychological Society.

Coordinating the effects of multiple variables: a skill fundamental to scientific thinking.

PubMed

Kuhn, Deanna; Pease, Maria; Wirkala, Clarice

2009-07-01

The skill of predicting outcomes based on simultaneous effects of multiple factors was examined. Over five sessions, 91 sixth graders engaged this task either individually or in pairs and either preceded or followed by six sessions on the more widely studied inquiry task that requires designing and interpreting experiments to identify individual effects. Final assessment, while indicating a high level of mastery on the inquiry task, showed progress but continuing conceptual challenges on the multivariable prediction task having to do with understanding of variables, variable levels, and consistency of a variable's operation across occasions. Task order had a significant but limited effect, and social collaboration conferred only a temporary benefit that disappeared in a final individual assessment. In a follow-up study, the lack of effect of social collaboration was confirmed, as was that of feedback on incorrect answers. Although fundamental to science, the concept that variables operate jointly and, under equivalent conditions, consistently across occasions is one that children appear to acquire only gradually and, therefore, one that cannot be assumed to be in place.

Reconstruction of genome-scale human metabolic models using omics data.

PubMed

Ryu, Jae Yong; Kim, Hyun Uk; Lee, Sang Yup

2015-08-01

The impact of genome-scale human metabolic models on human systems biology and medical sciences is becoming greater, thanks to increasing volumes of model building platforms and publicly available omics data. The genome-scale human metabolic models started with Recon 1 in 2007, and have since been used to describe metabolic phenotypes of healthy and diseased human tissues and cells, and to predict therapeutic targets. Here we review recent trends in genome-scale human metabolic modeling, including various generic and tissue/cell type-specific human metabolic models developed to date, and methods, databases and platforms used to construct them. For generic human metabolic models, we pay attention to Recon 2 and HMR 2.0 with emphasis on data sources used to construct them. Draft and high-quality tissue/cell type-specific human metabolic models have been generated using these generic human metabolic models. Integration of tissue/cell type-specific omics data with the generic human metabolic models is the key step, and we discuss omics data and their integration methods to achieve this task. The initial version of the tissue/cell type-specific human metabolic models can further be computationally refined through gap filling, reaction directionality assignment and the subcellular localization of metabolic reactions. We review relevant tools for this model refinement procedure as well. Finally, we suggest the direction of further studies on reconstructing an improved human metabolic model.

Consumption of high-fat meal containing cheese compared to a vegan alternative lowers postprandial C-reactive protein in overweight and obese individuals with metabolic abnormalities: a randomised controlled crossover study

USDA-ARS?s Scientific Manuscript database

Background. Dietary recommendations suggest decreased consumption of saturated fatty acids (SFA) to minimize cardiovascular disease risk, however not all foods rich in SFA are equivalent. It is proposed that the effect of SFA on postprandial inflammation is influenced by the specific composition and...

Verifying the Modal Logic Cube Is an Easy Task (For Higher-Order Automated Reasoners)

NASA Astrophysics Data System (ADS)

Benzmüller, Christoph

Prominent logics, including quantified multimodal logics, can be elegantly embedded in simple type theory (classical higher-order logic). Furthermore, off-the-shelf reasoning systems for simple type type theory exist that can be uniformly employed for reasoning within and about embedded logics. In this paper we focus on reasoning about modal logics and exploit our framework for the automated verification of inclusion and equivalence relations between them. Related work has applied first-order automated theorem provers for the task. Our solution achieves significant improvements, most notably, with respect to elegance and simplicity of the problem encodings as well as with respect to automation performance.

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

Lee, Gregory L.; Arnold, Dorian; LeGendre, Matthew

STAT is a light weight debugging tool that gathers and merges stack traces from all of the processes in a parallel application. STAT uses the MRNet tree based overlay network to broadcast commands from the tool front-end to the STAT daemons and for the front-end to gather the traces from the STAT daemons. As the traces propagate through the MRNet network tree, they are merged across all tasks to form a similar function call patterns and to delineate a small set of equivalence classes. A representative task from each of these classes can then be fed into a full featuremore » debugger like TolalView for root cause analysis.« less

Redundancy, Self-Motion, and Motor Control

PubMed Central

Martin, V.; Scholz, J. P.; Schöner, G.

2011-01-01

Outside the laboratory, human movement typically involves redundant effector systems. How the nervous system selects among the task-equivalent solutions may provide insights into how movement is controlled. We propose a process model of movement generation that accounts for the kinematics of goal-directed pointing movements performed with a redundant arm. The key element is a neuronal dynamics that generates a virtual joint trajectory. This dynamics receives input from a neuronal timer that paces end-effector motion along its path. Within this dynamics, virtual joint velocity vectors that move the end effector are dynamically decoupled from velocity vectors that do not. Moreover, the sensed real joint configuration is coupled back into this neuronal dynamics, updating the virtual trajectory so that it yields to task-equivalent deviations from the dynamic movement plan. Experimental data from participants who perform in the same task setting as the model are compared in detail to the model predictions. We discover that joint velocities contain a substantial amount of self-motion that does not move the end effector. This is caused by the low impedance of muscle joint systems and by coupling among muscle joint systems due to multiarticulatory muscles. Back-coupling amplifies the induced control errors. We establish a link between the amount of self-motion and how curved the end-effector path is. We show that models in which an inverse dynamics cancels interaction torques predict too little self-motion and too straight end-effector paths. PMID:19718817

Latency of modality-specific reactivation of auditory and visual information during episodic memory retrieval.

PubMed

Ueno, Daisuke; Masumoto, Kouhei; Sutani, Kouichi; Iwaki, Sunao

2015-04-15

This study used magnetoencephalography (MEG) to examine the latency of modality-specific reactivation in the visual and auditory cortices during a recognition task to determine the effects of reactivation on episodic memory retrieval. Nine right-handed healthy young adults participated in the experiment. The experiment consisted of a word-encoding phase and two recognition phases. Three encoding conditions were included: encoding words alone (word-only) and encoding words presented with either related pictures (visual) or related sounds (auditory). The recognition task was conducted in the MEG scanner 15 min after the completion of the encoding phase. After the recognition test, a source-recognition task was given, in which participants were required to choose whether each recognition word was not presented or was presented with which information during the encoding phase. Word recognition in the auditory condition was higher than that in the word-only condition. Confidence-of-recognition scores (d') and the source-recognition test showed superior performance in both the visual and the auditory conditions compared with the word-only condition. An equivalent current dipoles analysis of MEG data indicated that higher equivalent current dipole amplitudes in the right fusiform gyrus occurred during the visual condition and in the superior temporal auditory cortices during the auditory condition, both 450-550 ms after onset of the recognition stimuli. Results suggest that reactivation of visual and auditory brain regions during recognition binds language with modality-specific information and that reactivation enhances confidence in one's recognition performance.

Walking and non-walking space in an equivalent virtual reality task: Sexual dimorphism and aging decline of spatial abilities.

PubMed

Tascón, Laura; Castillo, Joaquín; León, Irene; Cimadevilla, José Manuel

2018-07-16

Spatial memory enables us to locate places and objects in space, to determine our position and manage spatial relationships in our environment. Our operations are displayed in a space that sometimes is inaccessible. In this case, the impossibility of movement within the context forces individuals to rely on the information gathered from limited viewpoints. This study investigates the use of walking and non-walking spaces using two equivalent virtual reality tasks in which displacement is only permitted in one of them. One hundred and fifty participants were divided into three age groups: 50-59, 60-69 and 70-79 year-old subjects. The starting position changed pseudo-randomly and two difficulty levels were set, with one and three positions to be found. Results provided evidence for 70-79 year-old people impairment of their spatial abilities compared with 50-59 and 60-69 year-old groups. In both difficulty conditions, participants made more errors in the non-walking space than in the walking space. All participants showed an improvement in the last trials of the task. Moreover, sexual dimorphism was registered in the high level of difficulty, in which men outperformed women. This study supports the idea that aging impairs the organization of spatial representations of the environment, and that this aspect is more noticeable in conditions where displacement is limited. Copyright © 2018 Elsevier B.V. All rights reserved.

Modulations in primary and secondary metabolic pathways and adjustment in physiological behaviour of Withania somnifera under drought stress.

PubMed

Singh, Ruchi; Gupta, Pankhuri; Khan, Furqan; Singh, Susheel Kumar; Sanchita; Mishra, Tripti; Kumar, Anil; Dhawan, Sunita Singh; Shirke, Pramod Arvind

2018-07-01

In general medicinal plants grown under water limiting conditions show much higher concentrations of secondary metabolites in comparison to control plants. In the present study, Withania somnifera plants were subjected to water stress and data related to drought tolerance phenomenon was collected and a putative mechanistic concept considering growth responses, physiological behaviour, and metabolite content and gene expression aspects is presented. Drought induced metabolic and physiological responses as well as drastic decrease in CO 2 uptake due to stomatal limitations. As a result, the consumption of reduction equivalents (NADPH 2+ ) for CO 2 assimilation via the calvin cycle declines significantly resulting in the generation of a large oxidative stress and an oversupply of antioxidant enzymes. Drought also results in the shifting of metabolic processes towards biosynthetic activities that consume reduction equivalents. Thus, biosynthesis of reduced compounds (isoprenoids, phenols and alkaloids) is enhanced. The dynamics of various metabolites have been discussed in the light of gene expression analysis of control and drought treated leaves. Gene encoding enzymes of pathways leading to glucose, fructose and fructan production, conversion of triose phosphates to hexoses and hexose phosphorylation were up-regulated in the drought stressed leaves. The down-regulated Calvin cycle genes were co-ordinately regulated with the down-regulation of chloroplast triosephosphate/phosphate translocator, cytoplasmic fructose-1,6-bisphosphate aldolase and fructose bisphosphatase. Expression of gene encoding Squalene Synthase (SQS) was highly upregulated under drought stress which is responsible for the diversion of carbon flux towards withanolides biosynthesis from isoprenoid pathway. Copyright © 2018 Elsevier B.V. All rights reserved.

Energetics of Respiration and Oxidative Phosphorylation in Mycobacteria.

PubMed

Cook, Gregory M; Hards, Kiel; Vilchèze, Catherine; Hartman, Travis; Berney, Michael

2014-06-01

Mycobacteria inhabit a wide range of intracellular and extracellular environments. Many of these environments are highly dynamic and therefore mycobacteria are faced with the constant challenge of redirecting their metabolic activity to be commensurate with either replicative growth or a non-replicative quiescence. A fundamental feature in this adaptation is the ability of mycobacteria to respire, regenerate reducing equivalents and generate ATP via oxidative phosphorylation. Mycobacteria harbor multiple primary dehydrogenases to fuel the electron transport chain and two terminal respiratory oxidases, an aa3 -type cytochrome c oxidase and cytochrome bd-type menaquinol oxidase, are present for dioxygen reduction coupled to the generation of a protonmotive force. Hypoxia leads to the downregulation of key respiratory complexes, but the molecular mechanisms regulating this expression are unknown. Despite being obligate aerobes, mycobacteria have the ability to metabolize in the absence of oxygen and a number of reductases are present to facilitate the turnover of reducing equivalents under these conditions (e.g. nitrate reductase, succinate dehydrogenase/fumarate reductase). Hydrogenases and ferredoxins are also present in the genomes of mycobacteria suggesting the ability of these bacteria to adapt to an anaerobic-type of metabolism in the absence of oxygen. ATP synthesis by the membrane-bound F1FO-ATP synthase is essential for growing and non-growing mycobacteria and the enzyme is able to function over a wide range of protonmotive force values (aerobic to hypoxic). The discovery of lead compounds that target respiration and oxidative phosphorylation in Mycobacterium tuberculosis highlights the importance of this area for the generation of new front line drugs to combat tuberculosis.

Spatial working memory in Wistar rats: brain sex differences in metabolic activity.

PubMed

Méndez-López, Magdalena; Méndez, Marta; López, Laudino; Arias, Jorge L

2009-05-29

Several works have shown that males and females differ in the ability to learn spatial locations in mazes. In this study, we used the Morris water maze to assess the acquisition of a spatial working memory (WM) task in adult male and female Wistar rats. The task consisted of a paired sample procedure made up of two daily identical trials, sample and retention. To study the oxidative metabolic activity of some brain limbic system regions after the WM task, we applied the cytochrome oxidase (COx) histochemistry. In addition to the experimental groups, free swimming control groups and untrained naïve groups were added to explore the COx changes not specific to the learning process. Similar spatial performances were found between sexes as only one more sample and retention trials were needed in males to reduce the escape latencies significantly. Males showed decreased COx activity as compared to control groups in the medial prefrontal cortex (prelimbic and infralimbic regions) as well as in the lateral septum and dentate gyrus. Regarding females, an increase in COx activity was found in nucleus accumbens, ventral tegmental area and supramammillary region in relation to control groups. Overall, these findings suggest that the acquisition of the spatial WM task is mediated by different subsystems in a sex-dependent manner that points to the hippocampus as the central structure in males whereas other structures would be central in females.

Evidence of MAOA genotype involvement in spatial ability in males

PubMed Central

Mueller, Sven C.; Cornwell, Brian R.; Grillon, Christian; MacIntyre, Jessica; Gorodetsky, Elena; Goldman, David; Pine, Daniel S.; Ernst, Monique

2014-01-01

Although the Monoamine Oxidase-A (MAOA) gene has been linked to spatial learning and memory in animal models, convincing evidence in humans is lacking. Performance on an ecologically-valid, virtual computer-based equivalent of the Morris Water Maze task was compared between 28 healthy males with the low MAOA transcriptional activity and 41 healthy age- and IQ-matched males with the high MAOA transcriptional activity. The results revealed consistently better performance (reduced heading error, shorter path length, and reduced failed trials) for the high MAOA activity individuals relative to the low activity individuals. By comparison, groups did not differ on pre-task variables or strategic measures such as first-move latency. The results provide novel evidence of MAOA gene involvement in human spatial navigation using a virtual analogue of the Morris Water Maze task. PMID:24671068

In-flight crew training

NASA Technical Reports Server (NTRS)

Gott, Charles; Galicki, Peter; Shores, David

1990-01-01

The Helmet Mounted Display system and Part Task Trainer are two projects currently underway that are closely related to the in-flight crew training concept. The first project is a training simulator and an engineering analysis tool. The simulator's unique helmet mounted display actually projects the wearer into the simulated environment of 3-D space. Miniature monitors are mounted in front of the wearers eyes. Partial Task Trainer is a kinematic simulator for the Shuttle Remote Manipulator System. The simulator consists of a high end graphics workstation with a high resolution color screen and a number of input peripherals that create a functional equivalent of the RMS control panel in the back of the Orbiter. It is being used in the training cycle for Shuttle crew members. Activities are underway to expand the capability of the Helmet Display System and the Partial Task Trainer.

Gradual training reduces practice difficulty while preserving motor learning of a novel locomotor task.

PubMed

Sawers, Andrew; Hahn, Michael E

2013-08-01

Motor learning strategies that increase practice difficulty and the size of movement errors are thought to facilitate motor learning. In contrast to this, gradual training minimizes movement errors and reduces practice difficulty by incrementally introducing task requirements, yet remains as effective as sudden training and its large movement errors for learning novel reaching tasks. While attractive as a locomotor rehabilitation strategy, it remains unknown whether the efficacy of gradual training extends to learning locomotor tasks and their unique requirements. The influence of gradual vs. sudden training on learning a locomotor task, asymmetric split belt treadmill walking, was examined by assessing whole body sagittal plane kinematics during 24 hour retention and transfer performance following either gradual or sudden training. Despite less difficult and less specific practice for the gradual cohort on day 1, gradual training resulted in equivalent motor learning of the novel locomotor task as sudden training when assessed by retention and transfer a day later. This suggests that large movement errors and increased practice difficulty may not be necessary for learning novel locomotor tasks. Further, gradual training may present a viable locomotor rehabilitation strategy avoiding large movement errors that could limit or impair improvements in locomotor performance. Copyright © 2013 Elsevier B.V. All rights reserved.

Molecular, metabolic, and genetic control: An introduction

NASA Astrophysics Data System (ADS)

Tyson, John J.; Mackey, Michael C.

2001-03-01

The living cell is a miniature, self-reproducing, biochemical machine. Like all machines, it has a power supply, a set of working components that carry out its necessary tasks, and control systems that ensure the proper coordination of these tasks. In this Special Issue, we focus on the molecular regulatory systems that control cell metabolism, gene expression, environmental responses, development, and reproduction. As for the control systems in human-engineered machines, these regulatory networks can be described by nonlinear dynamical equations, for example, ordinary differential equations, reaction-diffusion equations, stochastic differential equations, or cellular automata. The articles collected here illustrate (i) a range of theoretical problems presented by modern concepts of cellular regulation, (ii) some strategies for converting molecular mechanisms into dynamical systems, (iii) some useful mathematical tools for analyzing and simulating these systems, and (iv) the sort of results that derive from serious interplay between theory and experiment.

A Computational Approach to Estimate Interorgan Metabolic Transport in a Mammal

PubMed Central

Cui, Xiao; Geffers, Lars; Eichele, Gregor; Yan, Jun

2014-01-01

In multicellular organisms metabolism is distributed across different organs, each of which has specific requirements to perform its own specialized task. But different organs also have to support the metabolic homeostasis of the organism as a whole by interorgan metabolite transport. Recent studies have successfully reconstructed global metabolic networks in tissues and cell types and attempts have been made to connect organs with interorgan metabolite transport. Instead of these complicated approaches to reconstruct global metabolic networks, we proposed in this study a novel approach to study interorgan metabolite transport focusing on transport processes mediated by solute carrier (Slc) transporters and their couplings to cognate enzymatic reactions. We developed a computational approach to identify and score potential interorgan metabolite transports based on the integration of metabolism and transports in different organs in the adult mouse from quantitative gene expression data. This allowed us to computationally estimate the connectivity between 17 mouse organs via metabolite transport. Finally, by applying our method to circadian metabolism, we showed that our approach can shed new light on the current understanding of interorgan metabolite transport at a whole-body level in mammals. PMID:24971892

Task-oriented treadmill exercise training in chronic hemiparetic stroke

PubMed Central

Ivey, Frederick M.; Hafer-Macko, Charlene E.; Macko, Richard F.

2010-01-01

Patients with stroke have elevated hemiparetic gait costs secondary to low activity levels and are often severely deconditioned. Decrements in peak aerobic capacity affect functional ability and cardiovascular-metabolic health and may be partially mediated by molecular changes in hemiparetic skeletal muscle. Conventional rehabilitation is time delimited in the subacute stroke phase and does not provide adequate aerobic intensity to reverse the profound detriments to fitness and function that result from stroke. Hence, we have studied progressive full body weight-support treadmill (TM) training as an adjunct therapy in the chronic stroke phase. Task-oriented TM training has produced measurable changes in fitness, function, and indices of cardiovascular-metabolic health after stroke, but the precise mechanisms for these changes remain under investigation. Further, the optimal dose of this therapy has yet to be identified for individuals with stroke and may vary as a function of deficit severity and outcome goals. This article summarizes the functional and metabolic decline caused by inactivity after stroke and provides current evidence that supports the use of TM training during the chronic stroke phase, with protocols and inclusion/exclusion criteria described. Our research findings are discussed in relation to associated research. PMID:18566943

Energy expenditure during common sitting and standing tasks: examining the 1.5 MET definition of sedentary behaviour.

PubMed

Mansoubi, Maedeh; Pearson, Natalie; Clemes, Stacy A; Biddle, Stuart Jh; Bodicoat, Danielle H; Tolfrey, Keith; Edwardson, Charlotte L; Yates, Thomas

2015-05-29

Sedentary behavior is defined as any waking behavior characterized by an energy expenditure of 1.5 METS or less while in a sitting or reclining posture. This study examines this definition by assessing the energy cost (METs) of common sitting, standing and walking tasks. Fifty one adults spent 10 min during each activity in a variety of sitting tasks (watching TV, Playing on the Wii, Playing on the PlayStation Portable (PSP) and typing) and non-sedentary tasks (standing still, walking at 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6 mph). Activities were completed on the same day in a random order following an assessment of resting metabolic rate (RMR). A portable gas analyzer was used to measure oxygen uptake, and data were converted to units of energy expenditure (METs). Average of standardized MET values for screen-based sitting tasks were: 1.33 (SD: 0.24) METS (TV), 1.41 (SD: 0.28) (PSP), and 1.45 (SD: 0.32) (Typing). The more active, yet still seated, games on the Wii yielded an average of 2.06 (SD: 0.5) METS. Standing still yielded an average of 1.59 (SD: 0.37) METs. Walking MET values increased incrementally with speed from 2.17 to 2.99 (SD: 0.5 - 0.69) METs. The suggested 1.5 MET threshold for sedentary behaviors seems reasonable however some sitting based activities may be classified as non-sedentary. The effect of this on the definition of sedentary behavior and associations with metabolic health needs further investigation.

Quantifying the effects of the division of labor in metabolic pathways

PubMed Central

Harvey, Emily; Heys, Jeffrey; Gedeon, TomáS̆

2014-01-01

Division of labor is commonly observed in nature. There are several theories that suggest diversification in a microbial community may enhance stability and robustness, decrease concentration of inhibitory intermediates, and increase efficiency. Theoretical studies to date have focused on proving when the stable co-existence of multiple strains occurs, but have not investigated the productivity or biomass production of these systems when compared to a single ‘super microbe’ which has the same metabolic capacity. In this work we prove that if there is no change in the growth kinetics or yield of the metabolic pathways when the metabolism is specialized into two separate microbes, the biomass (and productivity) of a binary consortia system is always less than that of the equivalent monoculture. Using a specific example of Escherichia coli growing on a glucose substrate, we find that increasing the growth rates or substrate affinities of the pathways is not sufficient to explain the experimentally observed productivity increase in a community. An increase in pathway efficiency (yield) in specialized organisms provides the best explanation of the observed increase in productivity. PMID:25038317

Unifying Temporal and Structural Credit Assignment Problems

NASA Technical Reports Server (NTRS)

Agogino, Adrian K.; Tumer, Kagan

2004-01-01

Single-agent reinforcement learners in time-extended domains and multi-agent systems share a common dilemma known as the credit assignment problem. Multi-agent systems have the structural credit assignment problem of determining the contributions of a particular agent to a common task. Instead, time-extended single-agent systems have the temporal credit assignment problem of determining the contribution of a particular action to the quality of the full sequence of actions. Traditionally these two problems are considered different and are handled in separate ways. In this article we show how these two forms of the credit assignment problem are equivalent. In this unified frame-work, a single-agent Markov decision process can be broken down into a single-time-step multi-agent process. Furthermore we show that Monte-Carlo estimation or Q-learning (depending on whether the values of resulting actions in the episode are known at the time of learning) are equivalent to different agent utility functions in a multi-agent system. This equivalence shows how an often neglected issue in multi-agent systems is equivalent to a well-known deficiency in multi-time-step learning and lays the basis for solving time-extended multi-agent problems, where both credit assignment problems are present.

The metabolism of malate by cultured rat brain astrocytes

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

McKenna, M.C.; Tildon, J.T.; Couto, R.

1990-12-01

Since malate is known to play an important role in a variety of functions in the brain including energy metabolism, the transfer of reducing equivalents and possibly metabolic trafficking between different cell types; a series of biochemical determinations were initiated to evaluate the rate of 14CO2 production from L-(U-14C)malate in rat brain astrocytes. The 14CO2 production from labeled malate was almost totally suppressed by the metabolic inhibitors rotenone and antimycin A suggesting that most of malate metabolism was coupled to the electron transport system. A double reciprocal plot of the 14CO2 production from the metabolism of labeled malate revealed biphasicmore » kinetics with two apparent Km and Vmax values suggesting the presence of more than one mechanism of malate metabolism in these cells. Subsequent experiments were carried out using 0.01 mM and 0.5 mM malate to determine whether the addition of effectors would differentially alter the metabolism of high and low concentrations of malate. Effectors studied included compounds which could be endogenous regulators of malate metabolism and metabolic inhibitors which would provide information regarding the mechanisms regulating malate metabolism. Both lactate and aspartate decreased 14CO2 production from malate equally. However, a number of effectors were identified which selectively altered the metabolism of 0.01 mM malate including aminooxyacetate, furosemide, N-acetylaspartate, oxaloacetate, pyruvate and glucose, but had little or no effect on the metabolism of 0.5 mM malate. In addition, alpha-ketoglutarate and succinate decreased 14CO2 production from 0.01 mM malate much more than from 0.5 mM malate. In contrast, a number of effectors altered the metabolism of 0.5 mM malate more than 0.01 mM. These included methionine sulfoximine, glutamate, malonate, alpha-cyano-4-hydroxycinnamate and ouabain.« less

Alterations in Energy/Redox Metabolism Induced by Mitochondrial and Environmental Toxins: A Specific Role for Glucose-6-Phosphate-Dehydrogenase and the Pentose Phosphate Pathway in Paraquat Toxicity

PubMed Central

2015-01-01

Parkinson’s disease (PD) is a multifactorial disorder with a complex etiology including genetic risk factors, environmental exposures, and aging. While energy failure and oxidative stress have largely been associated with the loss of dopaminergic cells in PD and the toxicity induced by mitochondrial/environmental toxins, very little is known regarding the alterations in energy metabolism associated with mitochondrial dysfunction and their causative role in cell death progression. In this study, we investigated the alterations in the energy/redox-metabolome in dopaminergic cells exposed to environmental/mitochondrial toxins (paraquat, rotenone, 1-methyl-4-phenylpyridinium [MPP+], and 6-hydroxydopamine [6-OHDA]) in order to identify common and/or different mechanisms of toxicity. A combined metabolomics approach using nuclear magnetic resonance (NMR) and direct-infusion electrospray ionization mass spectrometry (DI-ESI-MS) was used to identify unique metabolic profile changes in response to these neurotoxins. Paraquat exposure induced the most profound alterations in the pentose phosphate pathway (PPP) metabolome. 13C-glucose flux analysis corroborated that PPP metabolites such as glucose-6-phosphate, fructose-6-phosphate, glucono-1,5-lactone, and erythrose-4-phosphate were increased by paraquat treatment, which was paralleled by inhibition of glycolysis and the TCA cycle. Proteomic analysis also found an increase in the expression of glucose-6-phosphate dehydrogenase (G6PD), which supplies reducing equivalents by regenerating nicotinamide adenine dinucleotide phosphate (NADPH) levels. Overexpression of G6PD selectively increased paraquat toxicity, while its inhibition with 6-aminonicotinamide inhibited paraquat-induced oxidative stress and cell death. These results suggest that paraquat “hijacks” the PPP to increase NADPH reducing equivalents and stimulate paraquat redox cycling, oxidative stress, and cell death. Our study clearly demonstrates that alterations in energy metabolism, which are specific for distinct mitochondiral/environmental toxins, are not bystanders to energy failure but also contribute significant to cell death progression. PMID:24937102

Appropriateness of the metabolic equivalent (MET) as an estimate of exercise intensity for post-myocardial infarction patients.

PubMed

Woolf-May, Kate; Meadows, Steve

2016-01-01

To explore: (1) whether during exercise metabolic equivalents (METs) appropriately indicate the intensity and/or metabolic cost for post-myocardial infarction (MI) males and (2) whether post-exercise VO 2 parameters provide insight into the intensity and/or metabolic cost of the prior exercise. 15 male phase-IV post-MIs (64.4±6.5 years) and 16 apparently healthy males (63.0±6.4 years) participated. Participants performed a graded cycle ergometer test (CET) of 50, 75 and 100 W, followed by 10 min active recovery (at 50 W) and 22 min seated recovery. Participants' heart rate (HR, bpm), expired air parameters and ratings of perceived exertion (exercise only) were measured. General linear model analysis showed throughout significantly lower HR values in post-MI participants that were related to β-blocker medication ( F (2,5) =18.47, p<0.01), with significantly higher VCO 2 /VO 2 ( F (2,5) =11.25, p<0.001) and gross kcals/LO 2 /min ( F (2,5) =11.25, p<0.001). Analysis comparing lines of regression showed, during the CET: post-MI participants worked at higher percentage of their anaerobic threshold (%AT)/MET than controls ( F (2,90) =18.98, p<0.001), as well as during active recovery (100-50 W) ( F (2,56) =20.81, p<0.001); during seated recovery: GLM analysis showed significantly higher values of VCO 2 /VO 2 for post-MI participants compared with controls ( F (2,3) =21.48, p=0.001) as well as gross kcals/LO 2 /min ( F (2,3) =21.48, p=0.001). Since METs take no consideration of any anaerobic component, they failed to reflect the significantly greater anaerobic contribution during exercise per MET for phase-IV post-MI patients. Given the anaerobic component will be greater for those with more severe forms of cardiac disease, current METs should be used with caution when determining exercise intensity in any patient with cardiac disease.

Human Research Program Human Health Countermeasures Element Nutrition Risk Standing Review Panel

NASA Technical Reports Server (NTRS)

Bistrian, Bruce

2009-01-01

The Nutrition Risk Standing Review Panel (SRP) reviewed and discussed the specific gaps and tasks for the Human Health Countermeasures (HHC) Element related to nutrition identified in the Human Research Program (HRP) Integrated Research Plan. There was general consensus that the described gaps and proposed tasks were critical to future NASA mission success. The SRP acknowledged the high scientific quality of the work currently being undertaken by the Nutritional Biochemistry group under the direction of Dr. Scott Smith. In review of the entire HRP, four new gaps were identified that complement the Element's existing research activities. Given the limitations of ground-based analogs for many of the unique physiological and metabolic alterations in space, future studies are needed to quantify nutritional factors that change during actual space flight. In addition, future tasks should seek to better evaluate the time course of physiological and metabolic alterations during flight to better predict alterations during longer duration missions. Finally, given the recent data suggesting a potential role for increased inflammatory responses during space flight, the role of inflammation needs to be explored in detail, including the development of potential countermeasures and new ground based analogs, if this possibility is confirmed.

Pseudo-Random Number Generation in Children with High-Functioning Autism and Asperger's Disorder: Further Evidence for a Dissociation in Executive Functioning?

ERIC Educational Resources Information Center

Rinehart, Nicole J.; Bradshaw, John L.; Moss, Simon A.; Brereton, Avril V.; Tonge, Bruce J.

2006-01-01

The repetitive, stereotyped and obsessive behaviours, which are core diagnostic features of autism, are thought to be underpinned by executive dysfunction. This study examined executive impairment in individuals with autism and Asperger's disorder using a verbal equivalent of an established pseudo-random number generating task. Different patterns…

Backward Blocking and Interference between Cues Are Empirically Equivalent in Non-Causally Framed Learning Tasks

ERIC Educational Resources Information Center

Luque, David; Moris, Joaquin; Orgaz, Cristina; Cobos, Pedro L.; Matute, Helena

2011-01-01

Backward blocking (BB) and interference between cues (IbC) are cue competition effects produced by very similar manipulations. In a standard BB design, both effects might occur simultaneously, which implies a potential problem for studying BB. In the present study with humans, the magnitude of both effects was compared using a non-causal scenario…

Socioeconomic, health, and dietary determinants of physical activity in a military occupational environment.

PubMed

Mullie, Patrick; Collee, Audrey; Clarys, Peter

2013-05-01

Health-related advantages of physical activity are well documented. The aim was to detect socioeconomic, health, and dietary determinants of physical activity. A cross-sectional design was used. Mailed questionnaires were sent to 5,000 Belgian military men. Dietary patterns were determined using the Mediterranean Diet Score (MDS). For physical activity, the validated International Physical Activity Questionnaire was used. Participation rate was 37% (n = 1,852). Mean total metabolic equivalent task (MET-total) varied between 6,224 MET-minutes/week for the age category 20 to 29 years to 4,578 MET-minutes/week for the age category 50 to 59 years. About 58% of the participants had a body mass index (BMI) above 25.0 kg/m(2). Logistic regression indicated a strong relation between MDS and MET-vigorous. A BMI increase of 1 kg/m(2) was associated with an odds ratio of 0.95 (95% confidence interval: 0.93-0.98), meaning that each increase of 1 kg/m(2) decreased MET-vigorous with 5%. Each additional life year decreased MET-vigorous with 3%. The high level of physical activity and the physical activity promoting and facilitating occupational environment seem to be insufficient to prevent adiposity. Vigorous physical activity was most discriminative and negatively related with increasing BMI, age, and smoking and positively related with MDS. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

25(OH)D levels in trained versus sedentary university students at 64° north.

PubMed

Jerome, Scott P; Sticka, Kendra D; Schnurr, Theresia M; Mangum, Sally J; Reynolds, Arleigh J; Dunlap, Kriya L

2017-01-01

25-hydroxyvitamin D (25[OH]D) deficiency is associated with compromised bone mineralisation, fatigue, suppressed immune function and unsatisfactory skeletal muscle recovery. We investigated the risk of 25(OH)D insufficiency or deficiency in endurance athletes compared to sedentary non-athletes living at 64° north. University student-athletes (TS) and sedentary students (SS) volunteered to participate in this study. TS engaged in regular exercise while SS exercised no more than 20 minutes/week. Metabolic Equivalent of Task (MET) scores for participants were determined. Vitamin D intake was assessed using the National Cancer Institute's 24-hour food recall (ASA24). Fasting plasma 25(OH)D levels were quantified via enzyme-linked immunosorbent assay. TS reported higher activity levels than SS as assessed with MET-minutes/week and ranking of physical activity levels (p < 0.05). The reported mean daily intake of vitamin D was higher in TS compared to SS (p < 0.05) while 25(OH)D plasma levels were lower in TS than in SS (p < 0.05). In total, 43.8% of the TS were either insufficient (31.3%) or deficient (12.5%) in 25(OH)D, while none of the SS were insufficient and 13.3% were deficient. TS are at increased risk of 25(OH)D insufficiency or deficiency compared to their sedentary counterparts residing at the same latitude, despite higher vitamin D intake.

Estimated and forecasted trends in domain specific time-use and energy expenditure among adults in Russia

PubMed Central

2014-01-01

Background Examination of historical trends and projections in estimated energy expenditure in Russia is important given the country’s economic downturns and growth. Methods Nationally representative data from the Russia Longitudinal Monitoring Survey (RLMS) from 1995–2011 was used to determine the metabolic equivalents of task (MET)-hours per week from occupational, domestic, travel, and active leisure physical activity (PA) domains, as well as sedentary leisure time (hours per week) among adults 18–60 years. Additionally, we projected what these values would be like in 2020 and 2030 if observed trends continue. Results Among male adults, the largest contributor to total PA was occupational PA followed by travel PA. In contrast, domestic PA followed by occupational PA contributed most to total PA among female adults. Total PA was 282.9 MET-hours per week in 1995 and declined to 231.7 in 2011. Total PA is projected to decrease to 216.5 MET-hours per week in 2020 and to 193.0 MET-hours per week in 2030. The greatest relative declines are occurring in travel PA. Female adults are also exhibiting significant declines in domestic PA. Changes in occupational and active leisure PA are less distinct. Conclusions Policies and initiatives are needed to counteract the long-term decline of overall physical activity linked with a modernizing lifestyle and economy among Russian adults. PMID:24475868

STIC3 - Silicon Photomultiplier Timing Chip with picosecond resolution

NASA Astrophysics Data System (ADS)

Stankova, Vera; Shen, Wei; Briggl, Konrad; Chen, Huangshan; Fischer, Peter; Gil, Alejandro; Harion, Tobias; Kiworra, Volker; Munwes, Yonathan; Ritzert, Michael; Schultz-Coulon, Hans-Christian

2015-07-01

The diagnostic of pancreas and prostate cancer is a challenging task due to the background noise coming from the closer organs. The EndoToFPET-US project aims to combine the synergy between metabolic and anatomical (ultrasound) image in order to improve the precision in the tumor localization. The goal of the project is to develop a Positron Emission Tomography (PET) system that provides a time-of-flight resolution of 200 ps FWHM for improving the signal to noise ratio and further to improve the medical image quality. In order to achieve this purpose an ASIC has been designed for very high timing resolution in time-of-flight (ToF) applications. In this paper we present the ASIC performance and the first characterization measurements with the 64-channels prototype version (STiC3). Measurements are performed with LYSO scintillator crystal and a Multi Pixel Photon Counter (MPPC). Measurements with the chip show an analog-front-end stage jitter of 35 ps for the first photo-electron equivalent charge and reach 18 ps for the third photo-electron. Coincidence time resolution (CTR) of 240 ps FWHM is measured with 3.1×3.1×15 mm3 LYSO crystal and 50 μm pixel pitch MPPC. Further optimization including the Time-to-Digital Converter (TDC) non-linearity corrections and setup fine tuning are ongoing for achieving the desired CTR of 200 ps FWHM.

Work- and travel-related physical activity and alcohol consumption: relationship with bone mineral density and calcaneal quantitative ultrasonometry.

PubMed

Sritara, Chanika; Thakkinstian, Ammarin; Ongphiphadhanakul, Boonsong; Pornsuriyasak, Prapaporn; Warodomwichit, Daruneewan; Akrawichien, Tawatchai; Vathesatogkit, Prin; Sritara, Piyamitr

2015-01-01

A number of healthy workers rarely exercise because of a lack of time or resources. Physical activity related to work and everyday travel may be more feasible, but evidence of its beneficial effect on bone health is scarce. We assessed if this form of physical activity was associated with higher bone mineral density (BMD) and stiffness index (SI) when adjusted for recreational physical activity, age, body mass index, smoking, alcohol consumption, education, and serum level of 25-hydroxyvitamin D. Healthy workers, aged 25-54 yr, of the Electricity Generating Authority of Thailand were surveyed. The outcomes were BMD (lumbar spine, femoral neck, and total hip) and calcaneal SI. Physical activity was estimated using the global physical activity questionnaire and considered active when >600 metabolic equivalent tasks (min). Of 2268 subjects, 74% were men. Active male subjects had significantly higher BMD at the femoral neck and total hip (p<0.005). However, the association was not significant with male lumbar spine BMD, male SI, or any bone parameters in women (p>0.05). In men, work and travel physical activity seems beneficial to male bone health; hence, it should be encouraged. Furthermore, smoking appeared harmful while moderate alcohol consumption was beneficial. Copyright © 2015 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Estimated and forecasted trends in domain specific time-use and energy expenditure among adults in Russia.

PubMed

Dearth-Wesley, Tracy; Popkin, Barry M; Ng, Shu Wen

2014-01-30

Examination of historical trends and projections in estimated energy expenditure in Russia is important given the country's economic downturns and growth. Nationally representative data from the Russia Longitudinal Monitoring Survey (RLMS) from 1995-2011 was used to determine the metabolic equivalents of task (MET)-hours per week from occupational, domestic, travel, and active leisure physical activity (PA) domains, as well as sedentary leisure time (hours per week) among adults 18-60 years. Additionally, we projected what these values would be like in 2020 and 2030 if observed trends continue. Among male adults, the largest contributor to total PA was occupational PA followed by travel PA. In contrast, domestic PA followed by occupational PA contributed most to total PA among female adults. Total PA was 282.9 MET-hours per week in 1995 and declined to 231.7 in 2011. Total PA is projected to decrease to 216.5 MET-hours per week in 2020 and to 193.0 MET-hours per week in 2030. The greatest relative declines are occurring in travel PA. Female adults are also exhibiting significant declines in domestic PA. Changes in occupational and active leisure PA are less distinct. Policies and initiatives are needed to counteract the long-term decline of overall physical activity linked with a modernizing lifestyle and economy among Russian adults.

A comparison of foveated acquisition and tracking performance relative to uniform resolution approaches

NASA Astrophysics Data System (ADS)

Dubuque, Shaun; Coffman, Thayne; McCarley, Paul; Bovik, A. C.; Thomas, C. William

2009-05-01

Foveated imaging has been explored for compression and tele-presence, but gaps exist in the study of foveated imaging applied to acquisition and tracking systems. Results are presented from two sets of experiments comparing simple foveated and uniform resolution targeting (acquisition and tracking) algorithms. The first experiments measure acquisition performance when locating Gabor wavelet targets in noise, with fovea placement driven by a mutual information measure. The foveated approach is shown to have lower detection delay than a notional uniform resolution approach when using video that consumes equivalent bandwidth. The second experiments compare the accuracy of target position estimates from foveated and uniform resolution tracking algorithms. A technique is developed to select foveation parameters that minimize error in Kalman filter state estimates. Foveated tracking is shown to consistently outperform uniform resolution tracking on an abstract multiple target task when using video that consumes equivalent bandwidth. Performance is also compared to uniform resolution processing without bandwidth limitations. In both experiments, superior performance is achieved at a given bandwidth by foveated processing because limited resources are allocated intelligently to maximize operational performance. These findings indicate the potential for operational performance improvements over uniform resolution systems in both acquisition and tracking tasks.

The Social Attribution Task-Multiple Choice (SAT-MC): A Psychometric and Equivalence Study of an Alternate Form

PubMed Central

Johannesen, Jason K.; Lurie, Jessica B.; Fiszdon, Joanna M.; Bell, Morris D.

2013-01-01

The Social Attribution Task-Multiple Choice (SAT-MC) uses a 64-second video of geometric shapes set in motion to portray themes of social relatedness and intentions. Considered a test of “Theory of Mind,” the SAT-MC assesses implicit social attribution formation while reducing verbal and basic cognitive demands required of other common measures. We present a comparability analysis of the SAT-MC and the new SAT-MC-II, an alternate form created for repeat testing, in a university sample (n = 92). Score distributions and patterns of association with external validation measures were nearly identical between the two forms, with convergent and discriminant validity supported by association with affect recognition ability and lack of association with basic visual reasoning. Internal consistency of the SAT-MC-II was superior (alpha = .81) to the SAT-MC (alpha = .56). Results support the use of SAT-MC and new SAT-MC-II as equivalent test forms. Demonstrating relatively higher association to social cognitive than basic cognitive abilities, the SAT-MC may provide enhanced sensitivity as an outcome measure of social cognitive intervention trials. PMID:23864984

Dimensional discontinuity in quantum communication complexity at dimension seven

NASA Astrophysics Data System (ADS)

Tavakoli, Armin; Pawłowski, Marcin; Żukowski, Marek; Bourennane, Mohamed

2017-02-01

Entanglement-assisted classical communication and transmission of a quantum system are the two quantum resources for information processing. Many information tasks can be performed using either quantum resource. However, this equivalence is not always present since entanglement-assisted classical communication is sometimes known to be the better performing resource. Here, we show not only the opposite phenomenon, that there exist tasks for which transmission of a quantum system is a more powerful resource than entanglement-assisted classical communication, but also that such phenomena can have a surprisingly strong dependence on the dimension of Hilbert space. We introduce a family of communication complexity problems parametrized by the dimension of Hilbert space and study the performance of each quantum resource. Under an additional assumption of a linear strategy for the receiving party, we find that for low dimensions the two resources perform equally well, whereas for dimension seven and above the equivalence is suddenly broken and transmission of a quantum system becomes more powerful than entanglement-assisted classical communication. Moreover, we find that transmission of a quantum system may even outperform classical communication assisted by the stronger-than-quantum correlations obtained from the principle of macroscopic locality.

Refractive Errors Affect the Vividness of Visual Mental Images

PubMed Central

Palermo, Liana; Nori, Raffaella; Piccardi, Laura; Zeri, Fabrizio; Babino, Antonio; Giusberti, Fiorella; Guariglia, Cecilia

2013-01-01

The hypothesis that visual perception and mental imagery are equivalent has never been explored in individuals with vision defects not preventing the visual perception of the world, such as refractive errors. Refractive error (i.e., myopia, hyperopia or astigmatism) is a condition where the refracting system of the eye fails to focus objects sharply on the retina. As a consequence refractive errors cause blurred vision. We subdivided 84 individuals according to their spherical equivalent refraction into Emmetropes (control individuals without refractive errors) and Ametropes (individuals with refractive errors). Participants performed a vividness task and completed a questionnaire that explored their cognitive style of thinking before their vision was checked by an ophthalmologist. Although results showed that Ametropes had less vivid mental images than Emmetropes this did not affect the development of their cognitive style of thinking; in fact, Ametropes were able to use both verbal and visual strategies to acquire and retrieve information. Present data are consistent with the hypothesis of equivalence between imagery and perception. PMID:23755186

Performance recovery of a class of uncertain non-affine systems with unmodelled dynamics: an indirect dynamic inversion method

NASA Astrophysics Data System (ADS)

Yi, Bowen; Lin, Shuyi; Yang, Bo; Zhang, Weidong

2018-02-01

This paper presents an output feedback indirect dynamic inversion (IDI) approach for a class of uncertain nonaffine systems with input unmodelled dynamics. Compared with previous approaches to achieve performance recovery, the proposed method aims at dealing with a broader class of nonaffine-in-control systems with triangular structure. An IDI state feedback law is designed first, in which less knowledge of the model plant is needed compared to earlier approximate dynamic inversion methods, thus yielding more robust performance. After that, an extended high-gain observer is designed to accomplish the task with output feedback. Finally, we prove that the designed IDI controller is equivalent to an adaptive proportional-integral (PI) controller, with respect to both time response equivalence and robustness equivalence. The conclusion implies that for the studied strict-feedback non-affine systems with unmodelled dynamics, there always exits a PI controller to stabilise the systems. The effectiveness and benefits of the designed approach are verified by three examples.

Refractive errors affect the vividness of visual mental images.

PubMed

Palermo, Liana; Nori, Raffaella; Piccardi, Laura; Zeri, Fabrizio; Babino, Antonio; Giusberti, Fiorella; Guariglia, Cecilia

2013-01-01

The hypothesis that visual perception and mental imagery are equivalent has never been explored in individuals with vision defects not preventing the visual perception of the world, such as refractive errors. Refractive error (i.e., myopia, hyperopia or astigmatism) is a condition where the refracting system of the eye fails to focus objects sharply on the retina. As a consequence refractive errors cause blurred vision. We subdivided 84 individuals according to their spherical equivalent refraction into Emmetropes (control individuals without refractive errors) and Ametropes (individuals with refractive errors). Participants performed a vividness task and completed a questionnaire that explored their cognitive style of thinking before their vision was checked by an ophthalmologist. Although results showed that Ametropes had less vivid mental images than Emmetropes this did not affect the development of their cognitive style of thinking; in fact, Ametropes were able to use both verbal and visual strategies to acquire and retrieve information. Present data are consistent with the hypothesis of equivalence between imagery and perception.

Genes associated with metabolic syndrome predict disease-free survival in stage II colorectal cancer patients. A novel link between metabolic dysregulation and colorectal cancer.

PubMed

Vargas, Teodoro; Moreno-Rubio, Juan; Herranz, Jesús; Cejas, Paloma; Molina, Susana; González-Vallinas, Margarita; Ramos, Ricardo; Burgos, Emilio; Aguayo, Cristina; Custodio, Ana B; Reglero, Guillermo; Feliu, Jaime; Ramírez de Molina, Ana

2014-12-01

Studies have recently suggested that metabolic syndrome and its components increase the risk of colorectal cancer. Both diseases are increasing in most countries, and the genetic association between them has not been fully elucidated. The objective of this study was to assess the association between genetic risk factors of metabolic syndrome or related conditions (obesity, hyperlipidaemia, diabetes mellitus type 2) and clinical outcome in stage II colorectal cancer patients. Expression levels of several genes related to metabolic syndrome and associated alterations were analysed by real-time qPCR in two equivalent but independent sets of stage II colorectal cancer patients. Using logistic regression models and cross-validation analysis with all tumour samples, we developed a metabolic syndrome-related gene expression profile to predict clinical outcome in stage II colorectal cancer patients. The results showed that a gene expression profile constituted by genes previously related to metabolic syndrome was significantly associated with clinical outcome of stage II colorectal cancer patients. This metabolic profile was able to identify patients with a low risk and high risk of relapse. Its predictive value was validated using an independent set of stage II colorectal cancer patients. The identification of a set of genes related to metabolic syndrome that predict survival in intermediate-stage colorectal cancer patients allows delineation of a high-risk group that may benefit from adjuvant therapy and avoid the toxic and unnecessary chemotherapy in patients classified as low risk. Our results also confirm the linkage between metabolic disorder and colorectal cancer and suggest the potential for cancer prevention and/or treatment by targeting these genes. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Visual Equivalence and Amodal Completion in Cuttlefish

PubMed Central

Lin, I-Rong; Chiao, Chuan-Chin

2017-01-01

Modern cephalopods are notably the most intelligent invertebrates and this is accompanied by keen vision. Despite extensive studies investigating the visual systems of cephalopods, little is known about their visual perception and object recognition. In the present study, we investigated the visual processing of the cuttlefish Sepia pharaonis, including visual equivalence and amodal completion. Cuttlefish were trained to discriminate images of shrimp and fish using the operant conditioning paradigm. After cuttlefish reached the learning criteria, a series of discrimination tasks were conducted. In the visual equivalence experiment, several transformed versions of the training images, such as images reduced in size, images reduced in contrast, sketches of the images, the contours of the images, and silhouettes of the images, were used. In the amodal completion experiment, partially occluded views of the original images were used. The results showed that cuttlefish were able to treat the training images of reduced size and sketches as the visual equivalence. Cuttlefish were also capable of recognizing partially occluded versions of the training image. Furthermore, individual differences in performance suggest that some cuttlefish may be able to recognize objects when visual information was partly removed. These findings support the hypothesis that the visual perception of cuttlefish involves both visual equivalence and amodal completion. The results from this research also provide insights into the visual processing mechanisms used by cephalopods. PMID:28220075

NUNDO: a numerical model of a human torso phantom and its application to effective dose equivalent calculations for astronauts at the ISS.

PubMed

Puchalska, Monika; Bilski, Pawel; Berger, Thomas; Hajek, Michael; Horwacik, Tomasz; Körner, Christine; Olko, Pawel; Shurshakov, Vyacheslav; Reitz, Günther

2014-11-01

The health effects of cosmic radiation on astronauts need to be precisely quantified and controlled. This task is important not only in perspective of the increasing human presence at the International Space Station (ISS), but also for the preparation of safe human missions beyond low earth orbit. From a radiation protection point of view, the baseline quantity for radiation risk assessment in space is the effective dose equivalent. The present work reports the first successful attempt of the experimental determination of the effective dose equivalent in space, both for extra-vehicular activity (EVA) and intra-vehicular activity (IVA). This was achieved using the anthropomorphic torso phantom RANDO(®) equipped with more than 6,000 passive thermoluminescent detectors and plastic nuclear track detectors, which have been exposed to cosmic radiation inside the European Space Agency MATROSHKA facility both outside and inside the ISS. In order to calculate the effective dose equivalent, a numerical model of the RANDO(®) phantom, based on computer tomography scans of the actual phantom, was developed. It was found that the effective dose equivalent rate during an EVA approaches 700 μSv/d, while during an IVA about 20 % lower values were observed. It is shown that the individual dose based on a personal dosimeter reading for an astronaut during IVA results in an overestimate of the effective dose equivalent of about 15 %, whereas under an EVA conditions the overestimate is more than 200 %. A personal dosemeter can therefore deliver quite good exposure records during IVA, but may overestimate the effective dose equivalent received during an EVA considerably.

Factorizing the motion sensitivity function into equivalent input noise and calculation efficiency.

PubMed

Allard, Rémy; Arleo, Angelo

2017-01-01

The photopic motion sensitivity function of the energy-based motion system is band-pass peaking around 8 Hz. Using an external noise paradigm to factorize the sensitivity into equivalent input noise and calculation efficiency, the present study investigated if the variation in photopic motion sensitivity as a function of the temporal frequency is due to a variation of equivalent input noise (e.g., early temporal filtering) or calculation efficiency (ability to select and integrate motion). For various temporal frequencies, contrast thresholds for a direction discrimination task were measured in presence and absence of noise. Up to 15 Hz, the sensitivity variation was mainly due to a variation of equivalent input noise and little variation in calculation efficiency was observed. The sensitivity fall-off at very high temporal frequencies (from 15 to 30 Hz) was due to a combination of a drop of calculation efficiency and a rise of equivalent input noise. A control experiment in which an artificial temporal integration was applied to the stimulus showed that an early temporal filter (generally assumed to affect equivalent input noise, not calculation efficiency) could impair both the calculation efficiency and equivalent input noise at very high temporal frequencies. We conclude that at the photopic luminance intensity tested, the variation of motion sensitivity as a function of the temporal frequency was mainly due to early temporal filtering, not to the ability to select and integrate motion. More specifically, we conclude that photopic motion sensitivity at high temporal frequencies is limited by internal noise occurring after the transduction process (i.e., neural noise), not by quantal noise resulting from the probabilistic absorption of photons by the photoreceptors as previously suggested.

Task- and time-dependent modulation of Ia presynaptic inhibition during fatiguing contractions performed by humans

PubMed Central

Maerz, Adam H.; Gould, Jeffrey R.; Enoka, Roger M.

2011-01-01

Presynaptic modulation of Ia afferents converging onto the motor neuron pool of the extensor carpi radialis (ECR) was compared during contractions (20% of maximal force) sustained to failure as subjects controlled either the angular position of the wrist while supporting an inertial load (position task) or exerted an equivalent force against a rigid restraint (force task). Test Hoffmann (H) reflexes were evoked in the ECR by stimulating the radial nerve above the elbow. Conditioned H reflexes were obtained by stimulating either the median nerve above the elbow or at the wrist (palmar branch) to assess presynaptic inhibition of homonymous (D1 inhibition) and heteronymous Ia afferents (heteronymous Ia facilitation), respectively. The position task was briefer than the force task (P = 0.001), although the maximal voluntary force and electromyograph for ECR declined similarly at failure for both tasks. Changes in the amplitude of the conditioned H reflex were positively correlated between the two conditioning methods (P = 0.02) and differed between the two tasks (P < 0.05). The amplitude of the conditioned H reflex during the position task first increased (129 ± 20.5% of the initial value, P < 0.001) before returning to its initial value (P = 0.22), whereas it increased progressively during the force task to reach 122 ± 17.4% of the initial value at failure (P < 0.001). Moreover, changes in conditioned H reflexes were associated with the time to task failure and force fluctuations. The results suggest a task- and time-dependent modulation of presynaptic inhibition of Ia afferents during fatiguing contractions. PMID:21543747

Elimination of the enhanced Simon effect for older adults in a three-choice situation: ageing and the Simon effect in a go/no-go Simon task.

PubMed

Kubo-Kawai, Namiko; Kawai, Nobuyuki

2010-03-01

In a Simon task, participants show better performance when the irrelevant stimulus location corresponds with the response location than when it does not, and this effect is typically greater for older adults than for younger adults. To study the effect of cognitive ageing in the Simon task, we compared young and old adults using two versions of the Simon task: (a) a standard visual Simon task, for which participants respond with left and right key-presses to the red and green colours of stimuli presented in left and right locations; (b) a go/no-go version of the Simon task, which was basically the same, except that the shape of the stimulus in one third of the trials indicates that no response is to be made. In both tasks, both age groups showed the Simon effect. The magnitude of the effect for the standard Simon task was greater for the older adults than for the younger adults. Nevertheless, the two groups showed an equivalent Simon effect in the go/no-go version of the Simon task. Reaction time distribution analyses revealed basically similar functions for both age groups: a decreasing pattern of the Simon effect in the standard task and an increasing pattern of the effect in the go/no-go version of the task. The results suggest that older adults find it more difficult to suppress an automatic activation of the corresponding response, though this automatic activation was reduced in situations where the response was frequently inhibited.

Consumption of high-fat meal containing cheese compared with vegan alternative lowers postprandial C-reactive protein in overweight and obese individuals with metabolic abnormalities: a randomized controlled cross-over study

USDA-ARS?s Scientific Manuscript database

Dietary recommendations suggest decreased consumption of SFA to minimize CVD risk; however, not all foods rich in SFA are equivalent. To evaluate the effects of SFA in a dairy food matrix, as Cheddar cheese, v. SFA from a vegan-alternative test meal on postprandial inflammatory markers, a randomized...

Regulation of substrate use during the marathon.

PubMed

Spriet, Lawrence L

2007-01-01

The energy required to run a marathon is mainly provided through oxidative phosphorylation in the mitochondria of the active muscles. Small amounts of energy from substrate phosphorylation are also required during transitions and short periods when running speed is increased. The three inputs for adenosine triphosphate production in the mitochondria include oxygen, free adenosine diphosphate and inorganic phosphate, and reducing equivalents. The reducing equivalents are derived from the metabolism of fat and carbohydrate (CHO), which are mobilised from intramuscular stores and also delivered from adipose tissue and liver, respectively. The metabolism of fat and CHO is tightly controlled at several regulatory sites during marathon running. Slower, recreational runners run at 60-65% maximal oxygen uptake (VO(2max)) for approximately 3:45:00 and faster athletes run at 70-75% for approximately 2:45:00. Both groups rely heavily on fat and CHO fuels. However, elite athletes run marathons at speeds requiring between 80% and 90% VO(2max), and finish in times between 2:05:00 and 2:20:00. They are highly adapted to oxidise fat and must do so during training. However, they compete at such high running speeds, that CHO oxidation (also highly adapted) may be the exclusive source of energy while racing. Further work with elite athletes is needed to examine this possibility.

The role of water ventilation and sediment ingestion in the uptake of benzo[A]pyrene in gizzard shad (Dorosoma cepedianum)

USGS Publications Warehouse

Kolok, Alan; Huckins, James N.; Petty, Jimmie D.; Oris, James T.

1996-01-01

The objective of this study was to determine whether sediment ingestion or water ventilation was the primary route of uptake for benzo[a]pyrene (BaP) in the gizzard shad (Dorosoma cepedianum), a detritivorous fish. Two experiments were conducted in which fish were exposed to sediments spiked with 1 μg/g BaP. In the first experiment, fish were prevented from feeding by esophagus ligation. In the second experiment, 20 nonligated fish and 30 ligated fish were added to the aquarium. The nonligated fish roiled the water as they fed. Fish were collected 4, 8, 15, and 22 d after the experiments began. Gizzard shad metabolize BaP; therefore, the concentrations of BaP equivalents (parent BaP plus metabolite) were determined. Concentrations of BaP equivalents were significantly greater in the ligated fish in experiment 2 relative to those in experiment 1. In contrast, the concentration of BaP equivalents in the ligated fish in experiment 2 was not significantly different than that in the nonligated fish. Our results suggest that ventilation of turbid water may be a significant source of BaP for gizzard shad. Sediment ingestion, however, does not appear to significantly influence the total body concentration of BaP equivalents in gizzard shad.

Carbohydrate oxidation coupled to Fe(III) reduction, a novel form of anaerobic metabolism

USGS Publications Warehouse

Coates, J.D.; Councell, T.; Ellis, D.J.; Lovley, D.R.

1998-01-01

An isolate, designated GC-29, that could incompletely oxidize glucose to acetate and carbon dioxide with Fe(III) serving as the electron acceptor was recovered from freshwater sediments of the Potomac River, Maryland. This metabolism yielded energy to support cell growth. Strain GC-29 is a facultatively anaerobic, Gram-negative motile rod which, in addition to glucose, also used sucrose, lactate, pyruvate, yeast extract, casamino acids or H2 as alternative electron donors for Fe(III) reduction. Stain GC-29 could reduce NO-3, Mn(IV), U(VI), fumarate, malate, S2O32-, and colloidal S0 as well as the humics analog, 2,6-anthraquinone disulfonate. Analysis of the almost complete 16S rRNA sequence indicated that strain GC-29 belongs in the Shewanella genus in the epsilon subdivision of the Proteobacteria. The name Shewanella saccharophilia is proposed. Shewanella saccharophilia differs from previously described fermentative microorganisms that metabolize glucose with the reduction of Fe(III) because it transfers significantly more electron equivalents to Fe(III); acetate and carbon dioxide are the only products of glucose metabolism; energy is conserved from Fe(III) reduction; and glucose is not metabolized in the absence of Fe(III). The metabolism of organisms like S. saccharophilia may account for the fact that glucose is metabolized primarily to acetate and carbon dioxide in a variety of sediments in which Fe(III) reduction is the terminal electron accepting process.

An investigation of cerebral oxygen utilization, blood flow and cognition in healthy aging.

PubMed

Catchlove, Sarah J; Macpherson, Helen; Hughes, Matthew E; Chen, Yufen; Parrish, Todd B; Pipingas, Andrew

2018-01-01

Understanding how vascular and metabolic factors impact on cognitive function is essential to develop efficient therapies to prevent and treat cognitive losses in older age. Cerebral metabolic rate of oxygen (CMRO2), cerebral blood flow (CBF) and venous oxygenation (Yv) comprise key physiologic processes that maintain optimum functioning of neural activity. Changes to these parameters across the lifespan may precede neurodegeneration and contribute to age-related cognitive decline. This study examined differences in blood flow and metabolism between 31 healthy younger (<50 years) and 29 healthy older (>50 years) adults; and investigated whether these parameters contribute to cognitive performance. Participants underwent a cognitive assessment and MRI scan. Grey matter CMRO2 was calculated from measures of CBF (phase contrast MRI), arterial and venous oxygenation (TRUST MRI) to assess group differences in physiological function and the contribution of these parameters to cognition. Performance on memory (p<0.001) and attention tasks (p<0.001) and total CBF were reduced (p<0.05), and Yv trended toward a decrease (p = .06) in the older group, while grey matter CBF and CMRO2 did not differ between the age groups. Attention was negatively associated with CBF when adjusted (p<0.05) in the older adults, but not in the younger group. There was no such relationship with memory. Neither cognitive measure was associated with oxygen metabolism or venous oxygenation in either age group. Findings indicated an age-related imbalance between oxygen delivery, consumption and demand, evidenced by a decreased supply of oxygen with unchanged metabolism resulting in increased oxygen extraction. CBF predicted attention when the age-effect was controlled, suggesting a task- specific CBF- cognition relationship.

Comparative metabolism and genotoxicity of the structurally similar nitrophenylenediamine dyes, HC Blue 1 and HC Blue 2, in mouse hepatocytes.

PubMed

Kari, F W; Driscoll, S M; Abu-Shakra, A; Strom, S C; Jenkins, W L; Volosin, J S; Rudo, K M; Langenbach, R

1990-04-01

Previous studies indicated that HC Blue 1 induced heptocellular carcinomas in B6C3F1 mice whereas the structurally similar nitroaromatic amine HC Blue 2 did not. In an attempt to elucidate the biochemical mechanisms responsible for their different carcinogenic potencies, comparative metabolism and genetic toxicity studies were undertaken. Eighteen-hour urinary recovery of administered radioactivity was equivalent for both compounds following oral gavage (100 mg/kg) in female B6C3F1 mice. By HPLC analysis, HC Blue 1 yielded 3 major polar metabolite peaks, one of which was susceptible to glucuronidase. In vivo metabolism of HC Blue 2 yielded a single major metabolite peak which was not hydrolyzed by glucuronidase. Metabolism by B6C3F1 mouse hepatocytes yielded metabolite profiles which were qualitatively similar to the profiles observed after in vivo metabolism. HC Blue 1 was metabolized by hepatocytes at approximately twice the rate of HC Blue 2. Cytogenetic evaluations of mouse hepatocytes after in vitro treatment indicated HC Blue 1 was more potent than HC Blue 2 in inducing chromosomal aberrations while both chemicals showed weak activity for inducing sister-chromatid exchanges. Furthermore, in the V79 cell metabolic cooperation assay, HC Blue 1, but not HC Blue 2, inhibited cell-to-cell communication suggesting a non-genotoxic activity may be present for HC Blue 1. It is concluded that qualitative and quantitative differences exist in the metabolism of these compounds and that genotoxic as well as nongenotoxic effects may contribute to their different carcinogenic potencies.

Systematic engineering of pentose phosphate pathway improves Escherichia coli succinate production.

PubMed

Tan, Zaigao; Chen, Jing; Zhang, Xueli

2016-01-01

Succinate biosynthesis of Escherichia coli is reducing equivalent-dependent and the EMP pathway serves as the primary reducing equivalent source under anaerobic condition. Compared with EMP, pentose phosphate pathway (PPP) is reducing equivalent-conserving but suffers from low efficacy. In this study, the ribosome binding site library and modified multivariate modular metabolic engineering (MMME) approaches are employed to overcome the low efficacy of PPP and thus increase succinate production. Altering expression levels of different PPP enzymes have distinct effects on succinate production. Specifically, increased expression of five enzymes, i.e., Zwf, Pgl, Gnd, Tkt, and Tal, contributes to increased succinate production, while the increased expression of two enzymes, i.e., Rpe and Rpi, significantly decreases succinate production. Modular engineering strategy is employed to decompose PPP into three modules according to position and function. Engineering of Zwf/Pgl/Gnd and Tkt/Tal modules effectively increases succinate yield and production, while engineering of Rpe/Rpi module decreases. Imbalance of enzymatic reactions in PPP is alleviated using MMME approach. Finally, combinational utilization of engineered PPP and SthA transhydrogenase enables succinate yield up to 1.61 mol/mol glucose, which is 94% of theoretical maximum yield (1.71 mol/mol) and also the highest succinate yield in minimal medium to our knowledge. In summary, we systematically engineered the PPP for improving the supply of reducing equivalents and thus succinate production. Besides succinate, these PPP engineering strategies and conclusions can also be applicable to the production of other reducing equivalent-dependent biorenewables.

Attention and implicit memory.

PubMed

Spataro, Pietro; Mulligan, Neil W; Rossi-Arnaud, Clelia

2011-01-01

The distinction between identification and production priming assumes that tasks based on production processes involve two distinct stages: the activation of multiple solutions and the following selection of a final response. Previous research demonstrated that divided attention reduced production but not identification priming. However, an unresolved issue concerns whether the activation of candidate solutions is sufficient to account for the enhanced request of attentional resources, independently from the contribution of selection processes. The present paper investigated this question by using a version of the lexical decision task (LDT) in which the target words had either many or few orthographic neighbors. Two experiments showed that the effects of divided and selective attention were equivalent in both conditions, suggesting that the inclusion of a process of generation of multiple solutions in the LDT is not sufficient to increase the amount of cognitive resources needed to achieve full priming to the levels of production tasks.

Just tell me what to do: bringing back experimenter control in active contingency tasks with the command-performance procedure and finding cue density effects along the way.

PubMed

Hannah, Samuel D; Beneteau, Jennifer L

2009-03-01

Active contingency tasks, such as those used to explore judgments of control, suffer from variability in the actual values of critical variables. The authors debut a new, easily implemented procedure that restores control over these variables to the experimenter simply by telling participants when to respond, and when to withhold responding. This command-performance procedure not only restores control over critical variables such as actual contingency, it also allows response frequency to be manipulated independently of contingency or outcome frequency. This yields the first demonstration, to our knowledge, of the equivalent of a cue density effect in an active contingency task. Judgments of control are biased by response frequency outcome frequency, just as they are also biased by outcome frequency. (c) 2009 APA, all rights reserved

Evidence of MAOA genotype involvement in spatial ability in males.

PubMed

Mueller, Sven C; Cornwell, Brian R; Grillon, Christian; Macintyre, Jessica; Gorodetsky, Elena; Goldman, David; Pine, Daniel S; Ernst, Monique

2014-07-01

Although the monoamine oxidase-A (MAOA) gene has been linked to spatial learning and memory in animal models, convincing evidence in humans is lacking. Performance on an ecologically-valid, virtual computer-based equivalent of the Morris Water Maze task was compared between 28 healthy males with the low MAOA transcriptional activity and 41 healthy age- and IQ-matched males with the high MAOA transcriptional activity. The results revealed consistently better performance (reduced heading error, shorter path length, and reduced failed trials) for the high MAOA activity individuals relative to the low activity individuals. By comparison, groups did not differ on pre-task variables or strategic measures such as first-move latency. The results provide novel evidence of MAOA gene involvement in human spatial navigation using a virtual analogue of the Morris Water Maze task. Copyright © 2014 Elsevier B.V. All rights reserved.

Real-time evaluation and visualization of learner performance in a mixed-reality environment for clinical breast examination.

PubMed

Kotranza, Aaron; Lind, D Scott; Lok, Benjamin

2012-07-01

We investigate the efficacy of incorporating real-time feedback of user performance within mixed-reality environments (MREs) for training real-world tasks with tightly coupled cognitive and psychomotor components. This paper presents an approach to providing real-time evaluation and visual feedback of learner performance in an MRE for training clinical breast examination (CBE). In a user study of experienced and novice CBE practitioners (n = 69), novices receiving real-time feedback performed equivalently or better than more experienced practitioners in the completeness and correctness of the exam. A second user study (n = 8) followed novices through repeated practice of CBE in the MRE. Results indicate that skills improvement in the MRE transfers to the real-world task of CBE of human patients. This initial case study demonstrates the efficacy of MREs incorporating real-time feedback for training real-world cognitive-psychomotor tasks.

Cognitive advantages and disadvantages in early and late bilinguals.

PubMed

Pelham, Sabra D; Abrams, Lise

2014-03-01

Previous research has documented advantages and disadvantages of early bilinguals, defined as learning a 2nd language by school age and using both languages since that time. Relative to monolinguals, early bilinguals manifest deficits in lexical access but benefits in executive function. We investigated whether becoming bilingual after childhood (late bilinguals) can produce the cognitive advantages and disadvantages typical of early bilinguals. Participants were 30 monolingual English speakers, 30 late English-Spanish bilinguals, and 30 early Spanish-English bilinguals who completed a picture naming task (lexical access) and an attentional network task (executive function). Late and early bilinguals manifested equivalent cognitive effects in both tasks, demonstrating lexical access deficits and executive function benefits. These findings provide support for the hypothesis that cognitive effects associated with bilingualism arise as the result of proficient, habitual use of 2 languages and not of developmental changes associated with becoming bilingual during childhood.

Childhood attention-deficit/hyperactivity disorder symptoms are risk factors for obesity and physical inactivity in adolescence.

PubMed

Khalife, Natasha; Kantomaa, Marko; Glover, Vivette; Tammelin, Tuija; Laitinen, Jaana; Ebeling, Hanna; Hurtig, Tuula; Jarvelin, Marjo-Riitta; Rodriguez, Alina

2014-04-01

To prospectively investigate the association and directionality between attention-deficit/hyperactivity disorder (ADHD) symptoms and obesity from childhood to adolescence in the general population. We examined whether obesogenic behaviors, namely, physical inactivity and binge eating, underlie the potential ADHD symptom-obesity association. We explored whether childhood conduct disorder (CD) symptoms are related to adolescent obesity/physical inactivity. At 7 to 8 years (n = 8,106), teachers reported ADHD and CD symptoms, and parents reported body mass index (BMI) and physically active play. At 16 years (n = 6,934), parents reported ADHD symptoms; adolescents reported physical activity (transformed to metabolic equivalent of task [MET] hours per week) and binge eating; BMI and waist-hip ratio (WHR) were measured via clinical examination. Obesity was defined using the International Obesity Task Force (IOTF) cut-offs for BMI and the 95th percentile cut-off for WHR. Childhood ADHD symptoms significantly predicted adolescent obesity, rather than the opposite. Inattention-hyperactivity symptoms at 8 years were associated with indices of obesity at 16 years (obese BMI: odds ratio [OR] = 1.91, 95% confidence interval [CI] = 1.10-3.33; 95th percentile WHR: OR = 1.71, 95% CI = 1.05-2.78), adjusted for gender, baseline BMI, physical activity, family structure change, and maternal education. Child CD symptoms associated with indices of adolescent obesity. Reduced physically active play in childhood predicted adolescent inattention (OR = 1.61, 95% CI = 1.16-2.24). Childhood ADHD and CD symptoms were linked with physical inactivity in adolescence (inattention-hyperactivity; OR = 1.60, 95% CI = 1.20-2.13), but not binge eating. Physical inactivity mediated the associations. Children with ADHD or CD symptoms are at increased risk for becoming obese and physically inactive adolescents. Physical activity may be beneficial for both behavior problems and obesity. Copyright © 2014 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Accommodation in Astigmatic Children During Visual Task Performance

PubMed Central

Harvey, Erin M.; Miller, Joseph M.; Apple, Howard P.; Parashar, Pavan; Twelker, J. Daniel; Crescioni, Mabel; Davis, Amy L.; Leonard-Green, Tina K.; Campus, Irene; Sherrill, Duane L.

2014-01-01

Purpose. To determine the accuracy and stability of accommodation in uncorrected children during visual task performance. Methods. Subjects were second- to seventh-grade children from a highly astigmatic population. Measurements of noncycloplegic right eye spherical equivalent (Mnc) were obtained while uncorrected subjects performed three visual tasks at near (40 cm) and distance (2 m). Tasks included reading sentences with stimulus letter size near acuity threshold and an age-appropriate letter size (high task demands) and viewing a video (low task demand). Repeated measures ANOVA assessed the influence of astigmatism, task demand, and accommodative demand on accuracy (mean Mnc) and variability (mean SD of Mnc) of accommodation. Results. For near and distance analyses, respectively, sample size was 321 and 247, mean age was 10.37 (SD 1.77) and 10.30 (SD 1.74) years, mean cycloplegic M was 0.48 (SD 1.10) and 0.79 diopters (D) (SD 1.00), and mean astigmatism was 0.99 (SD 1.15) and 0.75 D (SD 0.96). Poor accommodative accuracy was associated with high astigmatism, low task demand (video viewing), and high accommodative demand. The negative effect of accommodative demand on accuracy increased with increasing astigmatism, with the poorest accommodative accuracy observed in high astigmats (≥3.00 D) with high accommodative demand/high hyperopia (1.53 D and 2.05 D of underaccommodation for near and distant stimuli, respectively). Accommodative variability was greatest in high astigmats and was uniformly high across task condition. No/low and moderate astigmats showed higher variability for the video task than the reading tasks. Conclusions. Accuracy of accommodation is reduced in uncorrected children with high astigmatism and high accommodative demand/high hyperopia, but improves with increased visual task demand (reading). High astigmats showed the greatest variability in accommodation. PMID:25103265

Genome-scale model reveals metabolic basis of biomass partitioning in a model diatom

DOE PAGES

Levering, Jennifer; Broddrick, Jared; Dupont, Christopher L.; ...

2016-05-06

Diatoms are eukaryotic microalgae that contain genes from various sources, including bacteria and the secondary endosymbiotic host. Due to this unique combination of genes, diatoms are taxonomically and functionally distinct from other algae and vascular plants and confer novel metabolic capabilities. Based on the genome annotation, we performed a genome-scale metabolic network reconstruction for the marine diatom Phaeodactylum tricornutum. Due to their endosymbiotic origin, diatoms possess a complex chloroplast structure which complicates the prediction of subcellular protein localization. Based on previous work we implemented a pipeline that exploits a series of bioinformatics tools to predict protein localization. The manually curatedmore » reconstructed metabolic network iLB1027_lipid accounts for 1,027 genes associated with 4,456 reactions and 2,172 metabolites distributed across six compartments. To constrain the genome-scale model, we determined the organism specific biomass composition in terms of lipids, carbohydrates, and proteins using Fourier transform infrared spectrometry. Our simulations indicate the presence of a yet unknown glutamine-ornithine shunt that could be used to transfer reducing equivalents generated by photosynthesis to the mitochondria. Furthermore, the model reflects the known biochemical composition of P. tricornutum in defined culture conditions and enables metabolic engineering strategies to improve the use of P. tricornutum for biotechnological applications.« less

Correlation and Comparison of Various Anthropometric Measurements of Body Fat Distribution and Sagittal Abdominal Diameter as a Screening Tool for Cardio Metabolic Risk Factors and Ischaemic Heart Disease in Elderly Population.

PubMed

Sharda, Meenaxi; Jain, Pankaj; Gupta, Atul; Nagar, Deepti; Soni, Anil

2015-01-01

Primary objective of this study was to assess utility of sagittal abdominal diameter (SAD) as a cardio vascular risk predictor and compare various anthropometric measurement of body fat distribution in elderly patients. Four hundred patients were enrolled in study. Elderly patients more than 60 year of age attending medical OPD, geriatric OPD and suitable indoor patients who were willing to participate in the study were included. SAD was significantly higher in patient with ischaemic heart disease (group 1) than patient without ischaemic heart disease (Group 2) (P < 0.001 for male and female). SAD was better than WC to ascertain individual cardio metabolic risk factors in male, especially FBS (Pearson correlation .33 vs. .29), total cholesterol (Pearson correlation .24 vs. .20) as well as LDL cholesterol (Pearson correlation .13 vs. .05), while in female WC and SAD showed equal correlation with individual cardio metabolic risk factors. In patient with metabolic syndrome IHD group showed considerably higher mean SAD values. SAD also showed very good correlation with individual cardio metabolic risk factors especially in elderly male, while in female both SAD and.WC were almost equivalent.

Effects of post-encoding stress on performance in the DRM false memory paradigm

PubMed Central

Pardilla-Delgado, Enmanuelle; Alger, Sara E.; Cunningham, Tony J.; Kinealy, Brian

2016-01-01

Numerous studies have investigated how stress impacts veridical memory, but how stress influences false memory formation remains poorly understood. In order to target memory consolidation specifically, a psychosocial stress (TSST) or control manipulation was administered following encoding of 15 neutral, semantically related word lists (DRM false memory task) and memory was tested 24 h later. Stress decreased recognition of studied words, while increasing false recognition of semantically related lure words. Moreover, while control subjects remembered true and false words equivalently, stressed subjects remembered more false than true words. These results suggest that stress supports gist memory formation in the DRM task, perhaps by hindering detail-specific processing in the hippocampus. PMID:26670187

Performance evaluation of a kinesthetic-tactual display

NASA Technical Reports Server (NTRS)

Jagacinski, R. J.; Flach, J. M.; Gilson, R. D.; Dunn, R. S.

1982-01-01

Simulator studies demonstrated the feasibility of using kinesthetic-tactual (KT) displays for providing collective and cyclic command information, and suggested that KT displays may increase pilot workload capability. A dual-axis laboratory tracking task suggested that beyond reduction in visual scanning, there may be additional sensory or cognitive benefits to the use of multiple sensory modalities. Single-axis laboratory tracking tasks revealed performance with a quickened KT display to be equivalent to performance with a quickened visual display for a low frequency sum-of-sinewaves input. In contrast, an unquickened KT display was inferior to an unquickened visual display. Full scale simulator studies and/or inflight testing are recommended to determine the generality of these results.

Constant versus variable response signal delays in speed--accuracy trade-offs: effects of advance preparation for processing time.

PubMed

Miller, Jeff; Sproesser, Gudrun; Ulrich, Rolf

2008-07-01

In two experiments, we used response signals (RSs) to control processing time and trace out speed--accuracy trade-off(SAT) functions in a difficult perceptual discrimination task. Each experiment compared performance in blocks of trials with constant and, hence, temporally predictable RS lags against performance in blocks with variable, unpredictable RS lags. In both experiments, essentially equivalent SAT functions were observed with constant and variable RS lags. We conclude that there is little effect of advance preparation for a given processing time, suggesting that the discrimination mechanisms underlying SAT functions are driven solely by bottom-up information processing in perceptual discrimination tasks.

Mild Normobaric Hypoxia Exposure for Human-Autonomy System Testing

NASA Technical Reports Server (NTRS)

Stephens, Chad L.; Kennedy, Kellie D.; Crook, Brenda L.; Williams, Ralph A.; Schutte, Paul

2017-01-01

An experiment investigated the impact of normobaric hypoxia induction on aircraft pilot performance to specifically evaluate the use of hypoxia as a method to induce mild cognitive impairment to explore human-autonomous systems integration opportunities. Results of this exploratory study show that the effect of 15,000 feet simulated altitude did not induce cognitive deficits as indicated by performance on written, computer-based, or simulated flight tasks. However, the subjective data demonstrated increased effort by the human test subject pilots to maintain equivalent performance in a flight simulation task. This study represents current research intended to add to the current knowledge of performance decrement and pilot workload assessment to improve automation support and increase aviation safety.

Attractor Metabolic Networks

PubMed Central

De la Fuente, Ildefonso M.; Cortes, Jesus M.; Pelta, David A.; Veguillas, Juan

2013-01-01

Background The experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a Systemic Metabolic Structure in the cell, characterized by a set of different enzymatic reactions always locked into active states (metabolic core) while the rest of the catalytic processes are only intermittently active. This global metabolic structure was verified for Escherichia coli, Helicobacter pylori and Saccharomyces cerevisiae, and it seems to be a common key feature to all cellular organisms. In concordance with these observations, the cell can be considered a complex metabolic network which mainly integrates a large ensemble of self-organized multienzymatic complexes interconnected by substrate fluxes and regulatory signals, where multiple autonomous oscillatory and quasi-stationary catalytic patterns simultaneously emerge. The network adjusts the internal metabolic activities to the external change by means of flux plasticity and structural plasticity. Methodology/Principal Findings In order to research the systemic mechanisms involved in the regulation of the cellular enzymatic activity we have studied different catalytic activities of a dissipative metabolic network under different external stimuli. The emergent biochemical data have been analysed using statistical mechanic tools, studying some macroscopic properties such as the global information and the energy of the system. We have also obtained an equivalent Hopfield network using a Boltzmann machine. Our main result shows that the dissipative metabolic network can behave as an attractor metabolic network. Conclusions/Significance We have found that the systemic enzymatic activities are governed by attractors with capacity to store functional metabolic patterns which can be correctly recovered from specific input stimuli. The network attractors regulate the catalytic patterns, modify the efficiency in the connection between the multienzymatic complexes, and stably retain these modifications. Here for the first time, we have introduced the general concept of attractor metabolic network, in which this dynamic behavior is observed. PMID:23554883

Total physical activity volume, physical activity intensity, and metabolic syndrome: 1999-2004 National Health and Nutrition Examination Survey.

PubMed

Churilla, James R; Fitzhugh, Eugene C

2012-02-01

This study examined the association of total physical activity volume (TPAV) and physical activity (PA) from three domains [leisure-time physical activity (LTPA), domestic, transportation] with metabolic syndrome. We also investigated the relationship between LTPA intensity and metabolic syndrome risk. Sample included adults who participated in the 1999-2004 National Health and Nutrition Examination Survey. Physical activity measures were created for TPAV, LTPA, domestic PA, and transportational PA. For each, a six-level measure based upon no PA (level 1) and quintiles (levels 2-6) of metabolic equivalents (MET)·min·wk(-1) was created. A three-level variable associated with the current Department of Health and Human Services (DHHS) PA recommendation was also created. SAS and SUDAAN were used for the statistical analysis. Adults reporting the greatest volume of TPAV and LTPA were found to be 36% [odds ratio (OR) 0.64; 95% confidence interval (CI) 0.49-0.83] and 42% (OR 0.58; 95% CI 0.43-0.77), respectively, less likely to have metabolic syndrome. Domestic and transportational PA provided no specific level of protection from metabolic syndrome. Those reporting a TPAV that met the DHHS PA recommendation were found to be 33% (OR 0.67; 95%; CI 0.55-0.83) less likely to have metabolic syndrome compared to their sedentary counterparts. Adults reporting engaging in only vigorous-intensity LTPA were found to be 37% (OR 0.63; 95 CI 0.42-0.96) to 56% (OR 0.44; 95% CI 0.29-0.67) less likely to have metabolic syndrome. Volume, intensity, and domain of PA may all play important roles in reducing the prevalence and risk of metabolic syndrome.

Putting Essential Understanding of Ratios and Proportions into Practice in Grades 6-8

ERIC Educational Resources Information Center

Olson, Travis A.; Olson, Melfried; Slovin, Hannah

2015-01-01

Do your students think they can model ratios with sets of discrete objects and combine them to show the addition of ratios? Do they believe that equivalent ratios are based on additive relationships rather than multiplicative ones? What tasks can you offer what questions can you ask to determine what your students know or don't know and move them…

Where the item still rules supreme: Time-based selection, enumeration, pre-attentive processing and the target template?

PubMed

Watson, Derrick G

2017-01-01

I propose that there remains a central role for the item (or its equivalent) in a wider range of search and search-related tasks/functions than might be conveyed by the article. I consider the functional relationship between the framework and some aspects of previous theories, and suggest some challenges that the new framework might encounter.

You'll See What You Mean: Students Encode Equations Based on Their Knowledge of Arithmetic

ERIC Educational Resources Information Center

McNeil, Nicole M.; Alibali, Martha W.

2004-01-01

This study investigated the roles of problem structure and strategy use in problem encoding. Fourth-grade students solved and explained a set of typical addition problems (e.g., 5 + 4 + 9 + 5 = ?) and mathematical equivalence problems (e.g., 4 + 3 + 6 = 4 + ? or 6 + 4 + 5 = ? + 5). Next, they completed an encoding task in which they reconstructed…

Boys Will Be Boys; Cows Will Be Cows: Children's Essentialist Reasoning about Gender Categories and Animal Species

ERIC Educational Resources Information Center

Taylor, Marianne G.; Rhodes, Marjorie; Gelman, Susan A.

2009-01-01

Two studies (N = 456) compared the development of concepts of animal species and human gender, using a switched-at-birth reasoning task. Younger children (5- and 6-year-olds) treated animal species and human gender as equivalent; they made similar levels of category-based inferences and endorsed similar explanations for development in these 2…

Task-Driven Optimization of Fluence Field and Regularization for Model-Based Iterative Reconstruction in Computed Tomography.

PubMed

Gang, Grace J; Siewerdsen, Jeffrey H; Stayman, J Webster

2017-12-01

This paper presents a joint optimization of dynamic fluence field modulation (FFM) and regularization in quadratic penalized-likelihood reconstruction that maximizes a task-based imaging performance metric. We adopted a task-driven imaging framework for prospective designs of the imaging parameters. A maxi-min objective function was adopted to maximize the minimum detectability index ( ) throughout the image. The optimization algorithm alternates between FFM (represented by low-dimensional basis functions) and local regularization (including the regularization strength and directional penalty weights). The task-driven approach was compared with three FFM strategies commonly proposed for FBP reconstruction (as well as a task-driven TCM strategy) for a discrimination task in an abdomen phantom. The task-driven FFM assigned more fluence to less attenuating anteroposterior views and yielded approximately constant fluence behind the object. The optimal regularization was almost uniform throughout image. Furthermore, the task-driven FFM strategy redistribute fluence across detector elements in order to prescribe more fluence to the more attenuating central region of the phantom. Compared with all strategies, the task-driven FFM strategy not only improved minimum by at least 17.8%, but yielded higher over a large area inside the object. The optimal FFM was highly dependent on the amount of regularization, indicating the importance of a joint optimization. Sample reconstructions of simulated data generally support the performance estimates based on computed . The improvements in detectability show the potential of the task-driven imaging framework to improve imaging performance at a fixed dose, or, equivalently, to provide a similar level of performance at reduced dose.

Comparing the Frequency Effect Between the Lexical Decision and Naming Tasks in Chinese

PubMed Central

Wu, Jei-Tun

2016-01-01

In psycholinguistic research, the frequency effect can be one of the indicators for eligible experimental tasks that examine the nature of lexical access. Usually, only one of those tasks is chosen to examine lexical access in a study. Using two exemplar experiments, this paper introduces an approach to include both the lexical decision task and the naming task in a study. In the first experiment, the stimuli were Chinese characters with frequency and regularity manipulated. In the second experiment, the stimuli were switched to Chinese two-character words, in which the word frequency and the regularity of the leading character were manipulated. The logic of these two exemplar experiments was to explore some important issues such as the role of phonology on recognition by comparing the frequency effect between both the tasks. The results revealed different patterns of lexical access from those reported in the alphabetic systems. The results of Experiment 1 manifested a larger frequency effect in the naming task as compared to the LDT, when the stimuli were Chinese characters. And it is noteworthy that, in Experiment 1, when the stimuli were regular Chinese characters, the frequency effect observed in the naming task was roughly equivalent to that in the LDT. However, a smaller frequency effect was shown in the naming task as compared to the LDT, when the stimuli were switched to Chinese two-character words in Experiment 2. Taking advantage of the respective demands and characteristics in both tasks, researchers can obtain a more complete and precise picture of character/word recognition. PMID:27077703

Bond Graph Modeling of Chemiosmotic Biomolecular Energy Transduction.

PubMed

Gawthrop, Peter J

2017-04-01

Engineering systems modeling and analysis based on the bond graph approach has been applied to biomolecular systems. In this context, the notion of a Faraday-equivalent chemical potential is introduced which allows chemical potential to be expressed in an analogous manner to electrical volts thus allowing engineering intuition to be applied to biomolecular systems. Redox reactions, and their representation by half-reactions, are key components of biological systems which involve both electrical and chemical domains. A bond graph interpretation of redox reactions is given which combines bond graphs with the Faraday-equivalent chemical potential. This approach is particularly relevant when the biomolecular system implements chemoelectrical transduction - for example chemiosmosis within the key metabolic pathway of mitochondria: oxidative phosphorylation. An alternative way of implementing computational modularity using bond graphs is introduced and used to give a physically based model of the mitochondrial electron transport chain To illustrate the overall approach, this model is analyzed using the Faraday-equivalent chemical potential approach and engineering intuition is used to guide affinity equalisation: a energy based analysis of the mitochondrial electron transport chain.

Neuro-Compatible Metabolic Glycan Labeling of Primary Hippocampal Neurons in Noncontact, Sandwich-Type Neuron-Astrocyte Coculture.

PubMed

Choi, Ji Yu; Park, Matthew; Cho, Hyeoncheol; Kim, Mi-Hee; Kang, Kyungtae; Choi, Insung S

2017-12-20

Glycans are intimately involved in several facets of neuronal development and neuropathology. However, the metabolic labeling of surface glycans in primary neurons is a difficult task because of the neurotoxicity of unnatural monosaccharides that are used as a metabolic precursor, hindering the progress of metabolic engineering in neuron-related fields. Therefore, in this paper, we report a neurosupportive, neuron-astrocyte coculture system that neutralizes the neurotoxic effects of unnatural monosaccharides, allowing for the long-term observation and characterization of glycans in primary neurons in vitro. Polysialic acids in neurons are selectively imaged, via the metabolic labeling of sialoglycans with peracetylated N-azidoacetyl-d-mannosamine (Ac 4 ManNAz), for up to 21 DIV. Two-color labeling shows that neuronal activities, such as neurite outgrowth and recycling of membrane components, are highly dynamic and change over time during development. In addition, the insertion sites of membrane components are suggested to not be random, but be predominantly localized in developing neurites. This work provides a new research platform and also suggests advanced 3D systems for metabolic-labeling studies of glycans in primary neurons.

An Experimental Study of Team Size and Performance on a Complex Task.

PubMed

Mao, Andrew; Mason, Winter; Suri, Siddharth; Watts, Duncan J

2016-01-01

The relationship between team size and productivity is a question of broad relevance across economics, psychology, and management science. For complex tasks, however, where both the potential benefits and costs of coordinated work increase with the number of workers, neither theoretical arguments nor empirical evidence consistently favor larger vs. smaller teams. Experimental findings, meanwhile, have relied on small groups and highly stylized tasks, hence are hard to generalize to realistic settings. Here we narrow the gap between real-world task complexity and experimental control, reporting results from an online experiment in which 47 teams of size ranging from n = 1 to 32 collaborated on a realistic crisis mapping task. We find that individuals in teams exerted lower overall effort than independent workers, in part by allocating their effort to less demanding (and less productive) sub-tasks; however, we also find that individuals in teams collaborated more with increasing team size. Directly comparing these competing effects, we find that the largest teams outperformed an equivalent number of independent workers, suggesting that gains to collaboration dominated losses to effort. Importantly, these teams also performed comparably to a field deployment of crisis mappers, suggesting that experiments of the type described here can help solve practical problems as well as advancing the science of collective intelligence.

An Experimental Study of Team Size and Performance on a Complex Task

PubMed Central

Mao, Andrew; Mason, Winter; Suri, Siddharth; Watts, Duncan J.

2016-01-01

The relationship between team size and productivity is a question of broad relevance across economics, psychology, and management science. For complex tasks, however, where both the potential benefits and costs of coordinated work increase with the number of workers, neither theoretical arguments nor empirical evidence consistently favor larger vs. smaller teams. Experimental findings, meanwhile, have relied on small groups and highly stylized tasks, hence are hard to generalize to realistic settings. Here we narrow the gap between real-world task complexity and experimental control, reporting results from an online experiment in which 47 teams of size ranging from n = 1 to 32 collaborated on a realistic crisis mapping task. We find that individuals in teams exerted lower overall effort than independent workers, in part by allocating their effort to less demanding (and less productive) sub-tasks; however, we also find that individuals in teams collaborated more with increasing team size. Directly comparing these competing effects, we find that the largest teams outperformed an equivalent number of independent workers, suggesting that gains to collaboration dominated losses to effort. Importantly, these teams also performed comparably to a field deployment of crisis mappers, suggesting that experiments of the type described here can help solve practical problems as well as advancing the science of collective intelligence. PMID:27082239

Different strategies in solving series completion inductive reasoning problems: an fMRI and computational study.

PubMed

Liang, Peipeng; Jia, Xiuqin; Taatgen, Niels A; Zhong, Ning; Li, Kuncheng

2014-08-01

Neural correlate of human inductive reasoning process is still unclear. Number series and letter series completion are two typical inductive reasoning tasks, and with a common core component of rule induction. Previous studies have demonstrated that different strategies are adopted in number series and letter series completion tasks; even the underlying rules are identical. In the present study, we examined cortical activation as a function of two different reasoning strategies for solving series completion tasks. The retrieval strategy, used in number series completion tasks, involves direct retrieving of arithmetic knowledge to get the relations between items. The procedural strategy, used in letter series completion tasks, requires counting a certain number of times to detect the relations linking two items. The two strategies require essentially the equivalent cognitive processes, but have different working memory demands (the procedural strategy incurs greater demands). The procedural strategy produced significant greater activity in areas involved in memory retrieval (dorsolateral prefrontal cortex, DLPFC) and mental representation/maintenance (posterior parietal cortex, PPC). An ACT-R model of the tasks successfully predicted behavioral performance and BOLD responses. The present findings support a general-purpose dual-process theory of inductive reasoning regarding the cognitive architecture. Copyright © 2014 Elsevier B.V. All rights reserved.

Task-dependent modulation of regions in the left temporal cortex during auditory sentence comprehension.

PubMed

Zhang, Linjun; Yue, Qiuhai; Zhang, Yang; Shu, Hua; Li, Ping

2015-01-01

Numerous studies have revealed the essential role of the left lateral temporal cortex in auditory sentence comprehension along with evidence of the functional specialization of the anterior and posterior temporal sub-areas. However, it is unclear whether task demands (e.g., active vs. passive listening) modulate the functional specificity of these sub-areas. In the present functional magnetic resonance imaging (fMRI) study, we addressed this issue by applying both independent component analysis (ICA) and general linear model (GLM) methods. Consistent with previous studies, intelligible sentences elicited greater activity in the left lateral temporal cortex relative to unintelligible sentences. Moreover, responses to intelligibility in the sub-regions were differentially modulated by task demands. While the overall activation patterns of the anterior and posterior superior temporal sulcus and middle temporal gyrus (STS/MTG) were equivalent during both passive and active tasks, a middle portion of the STS/MTG was found to be selectively activated only during the active task under a refined analysis of sub-regional contributions. Our results not only confirm the critical role of the left lateral temporal cortex in auditory sentence comprehension but further demonstrate that task demands modulate functional specialization of the anterior-middle-posterior temporal sub-areas. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Load-dependent brain activation assessed by time-domain functional near-infrared spectroscopy during a working memory task with graded levels of difficulty

NASA Astrophysics Data System (ADS)

Molteni, Erika; Contini, Davide; Caffini, Matteo; Baselli, Giuseppe; Spinelli, Lorenzo; Cubeddu, Rinaldo; Cerutti, Sergio; Bianchi, Anna Maria; Torricelli, Alessandro

2012-05-01

We evaluated frontal brain activation during a mixed attentional/working memory task with graded levels of difficulty in a group of 19 healthy subjects, by means of time-domain functional near-infrared spectroscopy (fNIRS). Brain activation was assessed, and load-related oxy- and deoxy-hemoglobin changes were studied. Generalized linear model (GLM) was applied to the data to explore the metabolic processes occurring during the mental effort and, possibly, their involvement in short-term memorization. GLM was applied to the data twice: for modeling the task as a whole and for specifically investigating brain activation at each cognitive load. This twofold employment of GLM allowed (1) the extraction and isolation of different information from the same signals, obtained through the modeling of different cognitive categories (sustained attention and working memory), and (2) the evaluation of model fitness, by inspection and comparison of residuals (i.e., unmodeled part of the signal) obtained in the two different cases. Results attest to the presence of a persistent attentional-related metabolic activity, superimposed to a task-related mnemonic contribution. Some hemispherical differences have also been highlighted frontally: deoxy-hemoglobin changes manifested a strong right lateralization, whereas modifications in oxy- and total hemoglobin showed a medial localization. The present work successfully explored the capability of fNIRS to detect the two neurophysiological categories under investigation and distinguish their activation patterns.

Effect of physical workload and modality of information presentation on pattern recognition and navigation task performance by high-fit young males.

PubMed

Zahabi, Maryam; Zhang, Wenjuan; Pankok, Carl; Lau, Mei Ying; Shirley, James; Kaber, David

2017-11-01

Many occupations require both physical exertion and cognitive task performance. Knowledge of any interaction between physical demands and modalities of cognitive task information presentation can provide a basis for optimising performance. This study examined the effect of physical exertion and modality of information presentation on pattern recognition and navigation-related information processing. Results indicated males of equivalent high fitness, between the ages of 18 and 34, rely more on visual cues vs auditory or haptic for pattern recognition when exertion level is high. We found that navigation response time was shorter under low and medium exertion levels as compared to high intensity. Navigation accuracy was lower under high level exertion compared to medium and low levels. In general, findings indicated that use of the haptic modality for cognitive task cueing decreased accuracy in pattern recognition responses. Practitioner Summary: An examination was conducted on the effect of physical exertion and information presentation modality in pattern recognition and navigation. In occupations requiring information presentation to workers, who are simultaneously performing a physical task, the visual modality appears most effective under high level exertion while haptic cueing degrades performance.

Driving performance in a power wheelchair simulator.

PubMed

Archambault, Philippe S; Tremblay, Stéphanie; Cachecho, Sarah; Routhier, François; Boissy, Patrick

2012-05-01

A power wheelchair simulator can allow users to safely experience various driving tasks. For such training to be efficient, it is important that driving performance be equivalent to that in a real wheelchair. This study aimed at comparing driving performance in a real and in a simulated environment. Two groups of healthy young adults performed different driving tasks, either in a real power wheelchair or in a simulator. Smoothness of joystick control as well as the time necessary to complete each task were recorded and compared between the two groups. Driving strategies were analysed from video recordings. The sense of presence, of really being in the virtual environment, was assessed through a questionnaire. Smoothness of joystick control was the same in the real and virtual groups. Task completion time was higher in the simulator for the more difficult tasks. Both groups showed similar strategies and difficulties. The simulator generated a good sense of presence, which is important for motivation. Performance was very similar for power wheelchair driving in the simulator or in real life. Thus, the simulator could potentially be used to complement training of individuals who require a power wheelchair and use a regular joystick. [Box: see text].

The influence of positive vs. negative affect on multitasking.

PubMed

Morgan, Brent; D'Mello, Sidney K

2016-10-01

Considerable research has investigated how affect influences performance on a single task; however, little is known about the role of affect in complex multitasking environments. In this paper, 178 participants multitasked in a synthetic work environment (SYNWORK) consisting of memory, visual monitoring, auditory monitoring, and math tasks. Participants multitasked for a 3-min baseline phase (MT1), following which they were randomly assigned to watch one of three affect-induction videos: positive, neutral, or negative. Participants then resumed multitasking for two additional critical phases (MT2, MT3; 3min each). In MT2, performance of the positive and neutral conditions was statistically equivalent and higher than the negative condition. In MT3, the positive condition performed better than the negative condition, with the neutral condition not significantly different from the other two. The differences in overall multitasking scores were largely driven by errors in the Math task (the most cognitively demanding task) in MT2 and the Memory task in MT3. These findings have implications for how positive and negative affective states influence processing in a cognitively demanding multitasking environment. Copyright © 2016 Elsevier B.V. All rights reserved.

The Potential Feasibility of Chlorinic Photosynthesis on Extrasolar Planets

NASA Astrophysics Data System (ADS)

Haas, Johnson

2009-09-01

It is highly likely that the first convincing evidence of extrasolar life will arrive in the form of atmospheric absorption spectra. The modern search for life-bearing extrasolar planets emphasizes the potential detection of O2 and O3 absorption spectra in exoplanetary atmospheres as archetypal signatures of biology. However, oxygenic photosynthesis apparently failed to evolve independently more than once on Earth, and is thus unlikely to be reliably ubiquitous throughout the universe. Alternative evolutionary paths may yield planetary atmospheres tinted with the waste products of other dominant metabolisms, including potentially exotic biochemistries. This study examines the potential feasibility of one such exotic metabolism: chlorinic photosynthesis (CPS), defined as biologically-mediated halogenation of aqueous chloride to HClO, Cl2 or partially-oxidized intermediates (e.g. haloalkanes, haloacids, haloaromatics), coupled with photosynthetic CO2 fixation. This metabolic couple is feasible thermodynamically and appears to be geochemically plausible under approximately terrestrial conditions. This study hypothesizes that planetary biospheres dominated by CPS would develop atmospheres enriched with dihalogens and other halogenated compounds, evolve a highly oxidizing surface geochemical environment, and foster biological selection pressures favoring halogen resistance and eventual metazoan heterotrophy based on dihalogen and halocarbon respiration. Planets favoring the evolution of CPS would probably receive equivalent or greater surface UV flux than Earth did in the Paleoarchean (promoting abiotic photo-oxidation of aqueous halides, and establishing a strong biological selective pressure toward their accommodation), and would orbit stars having equivalent or greater bulk metallicities (promoting greater planetary halide abundances) relative to the Sun. Directed searches for such worlds should probably focus on A, F and G0 spectral class stars having bulk metallicities of +0.0 Dex or greater.

Severe NAFLD with hepatic necroinflammatory changes in mice fed trans fats and a high-fructose corn syrup equivalent

PubMed Central

Tetri, Laura H.; Basaranoglu, Metin; Brunt, Elizabeth M.; Yerian, Lisa M.; Neuschwander-Tetri, Brent A.

2008-01-01

The aims of this study were to determine whether combining features of a western lifestyle in mice with trans fats in a high-fat diet, high-fructose corn syrup in the water, and interventions designed to promote sedentary behavior would cause the hepatic histopathological and metabolic abnormalities that characterize nonalcoholic steatohepatitis (NASH). Male C57BL/6 mice fed ad libitum high-fat chow containing trans fats (partially hydrogenated vegetable oil) and relevant amounts of a high-fructose corn syrup (HFCS) equivalent for 1–16 wk were compared with mice fed standard chow or mice with trans fats or HFCS omitted. Cage racks were removed from western diet mice to promote sedentary behavior. By 16 wk, trans fat-fed mice became obese and developed severe hepatic steatosis with associated necroinflammatory changes. Plasma alanine aminotransferase levels increased, as did liver TNF-α and procollagen mRNA, indicating an inflammatory and profibrogenic response to injury. Glucose intolerance and impaired fasting glucose developed within 2 and 4 wk, respectively. Plasma insulin, resistin, and leptin levels increased in a profile similar to that seen in patients with NASH. The individual components of this diet contributed to the phenotype independently; isocaloric replacement of trans fats with lard established that trans fats played a major role in promoting hepatic steatosis and injury, whereas inclusion of HFCS promoted food consumption, obesity, and impaired insulin sensitivity. Combining risk factors for the metabolic syndrome by feeding mice trans fats and HFCS induced histological features of NASH in the context of a metabolic profile similar to patients with this disease. Because dietary trans fats promoted liver steatosis and injury, their role in the epidemic of NASH needs further evaluation. PMID:18772365

Severe NAFLD with hepatic necroinflammatory changes in mice fed trans fats and a high-fructose corn syrup equivalent.

PubMed

Tetri, Laura H; Basaranoglu, Metin; Brunt, Elizabeth M; Yerian, Lisa M; Neuschwander-Tetri, Brent A

2008-11-01

The aims of this study were to determine whether combining features of a western lifestyle in mice with trans fats in a high-fat diet, high-fructose corn syrup in the water, and interventions designed to promote sedentary behavior would cause the hepatic histopathological and metabolic abnormalities that characterize nonalcoholic steatohepatitis (NASH). Male C57BL/6 mice fed ad libitum high-fat chow containing trans fats (partially hydrogenated vegetable oil) and relevant amounts of a high-fructose corn syrup (HFCS) equivalent for 1-16 wk were compared with mice fed standard chow or mice with trans fats or HFCS omitted. Cage racks were removed from western diet mice to promote sedentary behavior. By 16 wk, trans fat-fed mice became obese and developed severe hepatic steatosis with associated necroinflammatory changes. Plasma alanine aminotransferase levels increased, as did liver TNF-alpha and procollagen mRNA, indicating an inflammatory and profibrogenic response to injury. Glucose intolerance and impaired fasting glucose developed within 2 and 4 wk, respectively. Plasma insulin, resistin, and leptin levels increased in a profile similar to that seen in patients with NASH. The individual components of this diet contributed to the phenotype independently; isocaloric replacement of trans fats with lard established that trans fats played a major role in promoting hepatic steatosis and injury, whereas inclusion of HFCS promoted food consumption, obesity, and impaired insulin sensitivity. Combining risk factors for the metabolic syndrome by feeding mice trans fats and HFCS induced histological features of NASH in the context of a metabolic profile similar to patients with this disease. Because dietary trans fats promoted liver steatosis and injury, their role in the epidemic of NASH needs further evaluation.

Interfering with free recall of words: Detrimental effects of phonological competition.

PubMed

Fernandes, Myra A; Wammes, Jeffrey D; Priselac, Sandra; Moscovitch, Morris

2016-09-01

We examined the effect of different distracting tasks, performed concurrently during memory retrieval, on recall of a list of words. By manipulating the type of material and processing (semantic, orthographic, and phonological) required in the distracting task, and comparing the magnitude of memory interference produced, we aimed to infer the kind of representation upon which retrieval of words depends. In Experiment 1, identifying odd digits concurrently during free recall disrupted memory, relative to a full attention condition, when the numbers were presented orthographically (e.g. nineteen), but not numerically (e.g. 19). In Experiment 2, a distracting task that required phonological-based decisions to either word or picture material produced large, but equivalent effects on recall of words. In Experiment 3, phonological-based decisions to pictures in a distracting task disrupted recall more than when the same pictures required semantically-based size estimations. In Experiment 4, a distracting task that required syllable decisions to line drawings interfered significantly with recall, while an equally difficult semantically-based color-decision task about the same line drawings, did not. Together, these experiments demonstrate that the degree of memory interference experienced during recall of words depends primarily on whether the distracting task competes for phonological representations or processes, and less on competition for semantic or orthographic or material-specific representations or processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radiation dose of nurses during IR procedures: a controlled trial evaluating operator alerts before nursing tasks.

PubMed

Komemushi, Atsushi; Suzuki, Satoshi; Sano, Akira; Kanno, Shohei; Kariya, Shuji; Nakatani, Miyuki; Yoshida, Rie; Kono, Yumiko; Ikeda, Koshi; Utsunomiya, Keita; Harima, Yoko; Komemushi, Sadao; Tanigawa, Noboru

2014-08-01

To compare radiation exposure of nurses when performing nursing tasks associated with interventional procedures depending on whether or not the nurses called out to the operator before approaching the patient. In a prospective study, 93 interventional radiology procedures were randomly divided into a call group and a no-call group; there were 50 procedures in the call group and 43 procedures in the no-call group. Two monitoring badges were used to calculate effective dose of nurses. In the call group, the nurse first told the operator she was going to approach the patient each time she was about to do so. In the no-call group, the nurse did not say anything to the operator when she was about to approach the patient. In all the nursing tasks, the equivalent dose at the umbilical level inside the lead apron was below the detectable limit. The equivalent dose at the sternal level outside the lead apron was 0.16 μSv ± 0.41 per procedure in the call group and 0.51 μSv ± 1.17 per procedure in the no-call group. The effective dose was 0.018 μSv ± 0.04 per procedure in the call group and 0.056 μSv ± 0.129 per procedure in the no-call group. The call group had a significantly lower radiation dose (P = .034). Radiation doses of nurses were lower in the group in which the nurse called to the operator before she approached the patient. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

On the nature of unintentional action: a study of force/moment drifts during multifinger tasks.

PubMed

Parsa, Behnoosh; O'Shea, Daniel J; Zatsiorsky, Vladimir M; Latash, Mark L

2016-08-01

We explored the origins of unintentional changes in performance during accurate force production in isometric conditions seen after turning visual feedback off. The idea of control with referent spatial coordinates suggests that these phenomena could result from drifts of the referent coordinate for the effector. Subjects performed accurate force/moment production tasks by pressing with the fingers of a hand on force sensors. Turning the visual feedback off resulted in slow drifts of both total force and total moment to lower magnitudes of these variables; these drifts were more pronounced in the right hand of the right-handed subjects. Drifts in individual finger forces could be in different direction; in particular, fingers that produced moments of force against the required total moment showed an increase in their forces. The force/moment drift was associated with a drop in the index of synergy stabilizing performance under visual feedback. The drifts in directions that changed performance (non-motor equivalent) and in directions that did not (motor equivalent) were of about the same magnitude. The results suggest that control with referent coordinates is associated with drifts of those referent coordinates toward the corresponding actual coordinates of the hand, a reflection of the natural tendency of physical systems to move toward a minimum of potential energy. The interaction between drifts of the hand referent coordinate and referent orientation leads to counterdirectional drifts in individual finger forces. The results also demonstrate that the sensory information used to create multifinger synergies is necessary for their presence over the task duration. Copyright © 2016 the American Physiological Society.

Recon2Neo4j: applying graph database technologies for managing comprehensive genome-scale networks.

PubMed

Balaur, Irina; Mazein, Alexander; Saqi, Mansoor; Lysenko, Artem; Rawlings, Christopher J; Auffray, Charles

2017-04-01

The goal of this work is to offer a computational framework for exploring data from the Recon2 human metabolic reconstruction model. Advanced user access features have been developed using the Neo4j graph database technology and this paper describes key features such as efficient management of the network data, examples of the network querying for addressing particular tasks, and how query results are converted back to the Systems Biology Markup Language (SBML) standard format. The Neo4j-based metabolic framework facilitates exploration of highly connected and comprehensive human metabolic data and identification of metabolic subnetworks of interest. A Java-based parser component has been developed to convert query results (available in the JSON format) into SBML and SIF formats in order to facilitate further results exploration, enhancement or network sharing. The Neo4j-based metabolic framework is freely available from: https://diseaseknowledgebase.etriks.org/metabolic/browser/ . The java code files developed for this work are available from the following url: https://github.com/ibalaur/MetabolicFramework . ibalaur@eisbm.org. Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

Recon2Neo4j: applying graph database technologies for managing comprehensive genome-scale networks

PubMed Central

Mazein, Alexander; Saqi, Mansoor; Lysenko, Artem; Rawlings, Christopher J.; Auffray, Charles

2017-01-01

Abstract Summary: The goal of this work is to offer a computational framework for exploring data from the Recon2 human metabolic reconstruction model. Advanced user access features have been developed using the Neo4j graph database technology and this paper describes key features such as efficient management of the network data, examples of the network querying for addressing particular tasks, and how query results are converted back to the Systems Biology Markup Language (SBML) standard format. The Neo4j-based metabolic framework facilitates exploration of highly connected and comprehensive human metabolic data and identification of metabolic subnetworks of interest. A Java-based parser component has been developed to convert query results (available in the JSON format) into SBML and SIF formats in order to facilitate further results exploration, enhancement or network sharing. Availability and Implementation: The Neo4j-based metabolic framework is freely available from: https://diseaseknowledgebase.etriks.org/metabolic/browser/. The java code files developed for this work are available from the following url: https://github.com/ibalaur/MetabolicFramework. Contact: ibalaur@eisbm.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27993779

[Effect of Low-Intensity 900 MHz Frequency Electromagnetic Radiation on Rat Brain Enzyme Activities Linked to Energy Metabolism].

PubMed

Petrosyan, M S; Nersesova, L S; Gazaryants, M G; Meliksetyan, G O; Malakyan, M G; Bajinyan, S A; Akopian, J I

2015-01-01

The research deals with the effect of low-intensity 900 MHz frequency electromagnetic radiation (EMR), power density 25 μW/cm2, on the following rat brain and blood serum enzyme activities: creatine kinase (CK), playing a central role in the process of storing and distributing the cell energy, as well as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) that play a key role in providing the conjunction of carbohydrate and amino acid metabolism. The comparative analysis of the changes in the enzyme activity studied at different times following the two-hour single, as well as fractional, radiation equivalent of the total time showed that the most radiosensitive enzyme is the brain creatine kinase, which may then be recommended as a marker of the radio frequency radiation impact. According to the analysis of the changing dynamics of the CK, ALT and AST activity level, with time these changes acquire the adaptive character and are directed to compensate the damaged cell energy metabolism.

[Animal experiment studies on the changes in lipid and protein metabolism in L-carnitine-supplemented total parenteral nutrition].

PubMed

Böhles, H; Segerer, H; Fekl, W; Stehr, K

1983-02-01

The influence of i.v. L-carnitine on parameters of lipid- and nitrogen metabolism was studied during total parenteral nutrition of mini pigs (x: 4077; n = 9). The infusion protocol was divided into isocaloric and isonitrogenous 48-hour-periods. Amino acids (3 g/kg/day) were administered throughout all three periods. 140 Cal/kg/day were given as non-protein calories, consisting only of glucose during period 1. During periods 2 and 3 an amount of glucose calorically equivalent to 4 g fat/kg/day was substituted with a lipid emulsion. In period 3, L-carnitine (1,5 mg/kg/day) was added. During the entire regime key parameters of fat and nitrogen metabolism were determined. During all three periods indirect calorimetry was performed and the respiratory quotient calculated. The results demonstrate a more effective lipolysis and oxydation of fatty acids during L-carnitine supplementation. This results in an increased energy gain from exogenously administered fat and a distinct improvement of nitrogen balance.

Impact of Food Matrix on Isoflavone Metabolism and Cardiovascular Biomarkers in Adults with Hypercholesterolemia

PubMed Central

Ahn-Jarvis, Jennifer; Clinton, Steven K.; Riedl, Kenneth M.; Vodovotz, Yael; Schwartz, Steven J.

2012-01-01

The role of food matrix and gender on soy isoflavone metabolism and biomarkers of activity were examined in twenty free-living adults (34.7±11.5 yrs old) with hypercholesterolemia (221.9 ±18.7mg/dL). In a randomized crossover design study, participants consumed soy-bread (3 wk) or soy-beverage (3 wk) containing 20 g soy protein with 99 and 93 mg isoflavones aglycone equivalents per day, respectively. During soy bread intervention, women had significantly greater microbial metabolite excretion (P=0.05) of isoflavonoids than men. In men, isoflavone metabolite excretion was not discernibly different between the two matrices. Significant reductions (P ≤ 0.05) in triglycerides (24.8%), LDL cholesterol (6.0%), apolipoprotein A-I (12.3%), and lipid oxidative stress capacity (25.5%), were observed after soy food intervention. Our findings suggest that the food matrix significantly impacts soy isoflavone metabolism, particularly microbial metabolites in women. PMID:22739802

Impairment of willed actions and use of advance information for movement preparation in schizophrenia

PubMed Central

Fuller, R.; Jahanshahi, M.

1999-01-01

OBJECTIVES—To assess willed actions in patients with schizophrenia using reaction time (RT) tasks that differ in the degree to which they involve volitionally controlled versus stimulus driven responses.
METHODS—Ten patients diagnosed with schizophrenia and 13 normal controls of comparable age were tested. Subjects performed a visual simple RT (SRT), an uncued four choice reaction time (CRT), and a fully cued four choice RT task. A stimulus 1(S1)−stimulus 2(S2) paradigm was used. The warning signal/precue (S1) preceded the imperative stimulus (S2) by either 0 (no warning signal or precue) 200, 800, 1600, or 3200ms.
RESULTS—The patients with schizophrenia had significantly slower RTs and movement times than normal subjects across all RT tasks. The unwarned SRT trials were significantly faster than the uncued CRT trials for both groups. For both groups, fully cued CRTs were significantly faster than the uncued CRTs. However, the S1−S2 interval had a differential effect on CRTs in the two groups. For the normal subjects fully cued CRTs and SRTs were equivalent when S1-S2 intervals were 800 ms or longer. A similar pattern of effects was not seen in the patients with schizophrenia, for whom the fully cued CRT were unexpectedly equivalent to SRT for the 200 ms interval and expectedly for the 1600 ms S1-S2 interval, but not the 3200 or 800 ms intervals.
CONCLUSIONS—Patients with schizophrenia were able to use advance information inherent in SRT or provided by the precue in fully cued CRT to speed up RT relative to uncued CRT. However, in the latter task, in which the volitional demands of preprogramming are higher since a different response has to be prepared on each trial, patients showed some unusual and inconsistent interval effects suggesting instability of attentional set. It is possible that future studies using RT tasks with higher volitional demands in patients with predominance of negative signs may disclose greater deficits in willed action in schizophrenia.

 PMID:10201424

Possible Triggers and Temporal Patterns of Implantable Cardioverter Defibrillator Discharges: A Preliminary Study

DTIC Science & Technology

1999-01-20

hypothesized possible mechanisms of changes in diet during holidays (sodium, alcohol, general increased caloric intake), stress during the holidays...aI., 1997) and more recent hypothesized explanations have included excess sodium and caloric intake and stress during the holiday season, as well as...metabolic equivalents (METs). 39% lower than the energy expenditure of these subjects during maximal treadmill testing (9.3 ± 1.8 METs). Kloner et al

Working memory dysfunction associated with brain functional deficits and cellular metabolic changes in patients with generalized anxiety disorder.

PubMed

Moon, Chung-Man; Sundaram, Thirunavukkarasu; Choi, Nam-Gil; Jeong, Gwang-Woo

2016-08-30

Generalized anxiety disorder (GAD) is associated with brain functional and morphological changes in connected with emotional dysregulation and cognitive deficit. This study dealt with the neural functional deficits and metabolic abnormalities in working memory (WM) task with emotion-inducing distractors in patients with GAD. Fourteen patients with GAD and 14 healthy controls underwent functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy ((1)H-MRS) at 3T. In response to the emotional distractors in WM tasks, the patients concurrently showed higher activity in the hippocampus and lower activities in the superior occipital gyrus, superior parietal gyrus, dorsolateral prefrontal cortex (DLPFC) and precentral gyrus compared to the controls. MRS revealed significantly lower choline/creatine (Cho/Cr) and choline/N-acetylaspartate (Cho/NAA) ratios in the DLPFC. In particular, the Cho ratios were positively correlated with the brain activities based on blood oxygenation level-dependent signal change in the DLPFC. This study provides the first evidence for the association between the metabolic alterations and functional deficit in WM processing with emotion-inducing distractors in GAD. These findings will be helpful to understand the neural dysfunction in connection with WM impairment in GAD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Acute cocaine induced deficits in cognitive performance in rhesus macaque monkeys treated with baclofen

PubMed Central

Porrino, Linda J.; Hampson, Robert E.; Opris, Ioan; Deadwyler, Samuel A.

2013-01-01

Rationale Acute and/or chronic exposure to cocaine can affect cognitive performance, which may influence rate of recovery during treatment. Objective Effects of the GABA-B receptor agonist baclofen were assessed for potency to reverse the negative influence of acute, pre-session, intravenous (IV) injection of cocaine on cognitive performance in Macaca mulatta nonhuman primates. Methods Animals were trained to perform a modified delayed match to sample (DMS) task incorporating two types of trials with varying degrees of cognitive load that had different decision requirements in order to correctly utilize information retained over the delay interval. The effects of cocaine (0.2, 0.4, and 0.6 mg/kg, IV) alone and in combination with baclofen (0.29 and 0.40 mg/kg, IV) were examined with respect to sustained performance levels. Brain metabolic activity during performance of the task was assessed using PET imaged uptake of [18F]-fluorodeoxyglucose. Results Acute cocaine injections produced a dose-dependent decline in DMS performance selective for trials of high cognitive load. The GABA-receptor agonist baclofen, co-administered with cocaine, reversed task performance back to nondrug (saline IV) control levels. Simultaneous assessment of PET-imaged brain metabolic activity in prefrontal cortex (PFC) showed alterations by cocaine compared to PFC metabolic activation in nondrug (saline, IV) control DMS sessions, but like performance, PFC activation was returned to control levels by baclofen (0.40 mg/kg, IV) injected with cocaine. Conclusions The results show that baclofen, administered at a relatively high dose, reversed the cognitive deficits produced by acute cocaine intoxication that may have implications for use in chronic drug exposure. PMID:22836369

Dynamic metabolic modeling for a MAB bioprocess.

PubMed

Gao, Jianying; Gorenflo, Volker M; Scharer, Jeno M; Budman, Hector M

2007-01-01

Production of monoclonal antibodies (MAb) for diagnostic or therapeutic applications has become an important task in the pharmaceutical industry. The efficiency of high-density reactor systems can be potentially increased by model-based design and control strategies. Therefore, a reliable kinetic model for cell metabolism is required. A systematic procedure based on metabolic modeling is used to model nutrient uptake and key product formation in a MAb bioprocess during both the growth and post-growth phases. The approach combines the key advantages of stoichiometric and kinetic models into a complete metabolic network while integrating the regulation and control of cellular activity. This modeling procedure can be easily applied to any cell line during both the cell growth and post-growth phases. Quadratic programming (QP) has been identified as a suitable method to solve the underdetermined constrained problem related to model parameter identification. The approach is illustrated for the case of murine hybridoma cells cultivated in stirred spinners.

Information presentation through a head-worn display (“smart glasses”) has a smaller influence on the temporal structure of gait variability during dual-task gait compared to handheld displays (paper-based system and smartphone)

PubMed Central

Sedighi, Alireza; Ulman, Sophia M.

2018-01-01

The need to complete multiple tasks concurrently is a common occurrence both daily life and in occupational activities, which can often include simultaneous cognitive and physical demands. As one example, there is increasing availability of head-worn display technologies that can be employed when a user is mobile (e.g., while walking). This new method of information presentation may, however, introduce risks of adverse outcomes such as a decrement to gait performance. The goal of this study was thus to quantify the effects of a head-worn display (i.e., smart glasses) on motor variability during gait and to compare these effects with those of other common information displays (i.e., smartphone and paper-based system). Twenty participants completed four walking conditions, as a single task and in three dual-task conditions (three information displays). In the dual-task conditions, the information display was used to present several cognitive tasks. Three different measures were used to quantify variability in gait parameters for each walking condition (using the cycle-to-cycle standard deviation, sample entropy, and the “goal-equivalent manifold” approach). Our results indicated that participants used less adaptable gait strategies in dual-task walking using the paper-based system and smartphone conditions compared with single-task walking. Gait performance, however, was less affected during dual-task walking with the smart glasses. We conclude that the risk of an adverse gait event (e.g., a fall) in head-down walking conditions (i.e., the paper-based system and smartphone conditions) were higher than in single-task walking, and that head-worn displays might help reduce the risk of such events during dual-task gait conditions. PMID:29630614

Basic Color Terms (BCTs) and Categories (BCCs) in Three Dialects of the Spanish Language: Interaction Between Cultural and Universal Factors

PubMed Central

Lillo, Julio; González-Perilli, Fernando; Prado-León, Lilia; Melnikova, Anna; Álvaro, Leticia; Collado, José A.; Moreira, Humberto

2018-01-01

Two experiments were performed to identify and compare the Basic Color Terms (BCTs) and the Basic Color Categories (BCCs) included in three dialects (Castilian, Mexican, and Uruguayan) of the Spanish language. Monolexemic Elicited lists were used in the first experiment to identify the BCTs of each dialect. Eleven BCTs appeared for the Spanish and the Mexican, and twelve did so for the Uruguayan. The six primary BCTs (rojo “red,” verde “green,” amarillo “yellow,” azul “blue,” negro “black,” and blanco “white”) appeared in the three dialects. This occurred for only three derived BCTs (gris “gray,” naranja “orange,” and rosa “pink”) but not for the other five derived BCTs (celeste “sky blue,” marrón “brown,” café “brown,” morado “purple,” and violeta “purple”). Color transitions were used in the second experiment for two different tasks. Extremes naming task was used to determine the relation between two different dialects' BCTs: equality, equivalence or difference. The results provided the first evidence for marrón “brown” and café “brown” being equivalent terms for the same BCC (brown in English) as is the case of morado “purple” and violeta “purple.” Uruguayan celeste “sky blue” had no equivalent BCT in the other two dialects. Boundary delimitation task required the selection of the color in the boundary between two categories. The task was used to reasonably estimate the volume occupied by each BCC in the color space considering its chromatic area and lightness range. Excluding sky blue (celeste “sky blue”) and blue (azul “blue”), the other BCCs color volumes were similar across the three dialects. Uruguayan sky blue and blue volumes conjointly occupied the portion of the color space corresponding to the Castilian and Mexican blue BCC. The fact that the BCT celeste “sky blue” only appeared in Uruguayan very probably derived from specific cultural factors (the use of the color in the flags and the arrival of an important number of Italian immigrants). Nevertheless, these cultural factors seem to nurture from a perceptive structuring of the color space, which nature is universal, as the boundaries of this category can be delimited from the responses of Spanish and Mexican participants. PMID:29867702

Matching disease and phenotype ontologies in the ontology alignment evaluation initiative.

PubMed

Harrow, Ian; Jiménez-Ruiz, Ernesto; Splendiani, Andrea; Romacker, Martin; Woollard, Peter; Markel, Scott; Alam-Faruque, Yasmin; Koch, Martin; Malone, James; Waaler, Arild

2017-12-02

The disease and phenotype track was designed to evaluate the relative performance of ontology matching systems that generate mappings between source ontologies. Disease and phenotype ontologies are important for applications such as data mining, data integration and knowledge management to support translational science in drug discovery and understanding the genetics of disease. Eleven systems (out of 21 OAEI participating systems) were able to cope with at least one of the tasks in the Disease and Phenotype track. AML, FCA-Map, LogMap(Bio) and PhenoMF systems produced the top results for ontology matching in comparison to consensus alignments. The results against manually curated mappings proved to be more difficult most likely because these mapping sets comprised mostly subsumption relationships rather than equivalence. Manual assessment of unique equivalence mappings showed that AML, LogMap(Bio) and PhenoMF systems have the highest precision results. Four systems gave the highest performance for matching disease and phenotype ontologies. These systems coped well with the detection of equivalence matches, but struggled to detect semantic similarity. This deserves more attention in the future development of ontology matching systems. The findings of this evaluation show that such systems could help to automate equivalence matching in the workflow of curators, who maintain ontology mapping services in numerous domains such as disease and phenotype.

Normal aging reduces motor synergies in manual pointing.

PubMed

Verrel, Julius; Lövdén, Martin; Lindenberger, Ulman

2012-01-01

Depending upon its organization, movement variability may reflect poor or flexible control of a motor task. We studied adult age-related differences in the structure of postural variability in manual pointing using the uncontrolled manifold (UCM) method. Participants from 2 age groups (younger: 20-30 years; older: 70-80 years; 12 subjects per group) completed a total of 120 pointing trials to 2 different targets presented according to 3 schedules: blocked, alternating, and random. The age groups were similar with respect to basic kinematic variables, end point precision, as well as the accuracy of the biomechanical forward model of the arm. Following the uncontrolled manifold approach, goal-equivalent and nongoal-equivalent components of postural variability (goal-equivalent variability [GEV] and nongoal-equivalent variability [NGEV]) were determined for 5 time points of the movements (start, 10%, 50%, 90%, and end) and used to define a synergy index reflecting the flexibility/stability aspect of motor synergies. Toward the end of the movement, younger adults showed higher synergy indexes than older adults. Effects of target schedule were not reliable. We conclude that normal aging alters the organization of common multidegree-of-freedom movements, with older adults making less flexible use of motor abundance than younger adults. Copyright © 2012 Elsevier Inc. All rights reserved.

Cognitive Fatigue Influences Time-On-Task during Bodyweight Resistance Training Exercise

PubMed Central

Head, James R.; Tenan, Matthew S.; Tweedell, Andrew J.; Price, Thomas F.; LaFiandra, Michael E.; Helton, William S.

2016-01-01

Prior investigations have shown measurable performance impairments on continuous physical performance tasks when preceded by a cognitively fatiguing task. However, the effect of cognitive fatigue on bodyweight resistance training exercise task performance is unknown. In the current investigation 18 amateur athletes completed a full body exercise task preceded by either a cognitive fatiguing or control intervention. In a randomized repeated measure design, each participant completed the same exercise task preceded by a 52 min cognitively fatiguing intervention (vigilance) or control intervention (video). Data collection sessions were separated by 1 week. Participants rated the fatigue intervention with a significantly higher workload compared to the control intervention (p < 0.001). Additionally, participants self-reported significantly greater energetic arousal for cognitively fatiguing task (p = 0.02). Cognitive fatigue did not significantly impact number of repetitions completed during the exercise task (p = 0.77); however, when cognitively fatigued, participants had decreased percent time-on-task (57%) relative to the no fatigue condition (60%; p = 0.04). RPE significantly changed over time (p < 0.001), but failed to show significant differences between the cognitive fatigue intervention and control intervention (p > 0.05). There was no statistical difference for heart rate or metabolic expenditure as a function of fatigue intervention during exercise. Cognitively fatigued athletes have decreased time-on-task in bodyweight resistance training exercise tasks. PMID:27635122

Increases in both cerebral glucose utilization and blood flow during execution of a somatosensory task.

PubMed

Ginsberg, M D; Chang, J Y; Kelley, R E; Yoshii, F; Barker, W W; Ingenito, G; Boothe, T E

1988-02-01

To investigate local metabolic and hemodynamic interrelationships during functional activation of the brain, paired studies of local cerebral glucose utilization (lCMRGlc) and blood flow (lCBF) were carried out in 10 normal subjects (9 right-handed, 1 ambidextrous) at rest and during a unilateral discriminative somatosensory/motor task--palpation and sorting of mah-jongg tiles by engraved design. The extent of activation was assessed on the basis of percentage difference images following normalization to compensate for global shifts. The somatosensory stimulus elevated lCMRGlc by 16.9 +/- 3.5% (mean +/- standard deviation) and lCBF by 26.5 +/- 5.1% in the contralateral sensorimotor cortical focus; smaller increments were noted in the homologous ipsilateral site. The increments of lCMRGlc and lCBF correlated poorly with one another in individual subjects. Stimulation of the right hand resulted in significantly higher contralateral lCMRGlc activation (19.6%) than did stimulation of the left hand (14.1%) (p less than 0.005), whereas the lCBF response was independent of the hand stimulated. Our results indicate that both glycolytic metabolism and blood flow increase locally with the execution of an active sensorimotor task and suggest that both measures may serve as reliable markers of functional activation of the normal brain.

Automatic semantic encoding in verbal short-term memory: evidence from the concreteness effect.

PubMed

Campoy, Guillermo; Castellà, Judit; Provencio, Violeta; Hitch, Graham J; Baddeley, Alan D

2015-01-01

The concreteness effect in verbal short-term memory (STM) tasks is assumed to be a consequence of semantic encoding in STM, with immediate recall of concrete words benefiting from richer semantic representations. We used the concreteness effect to test the hypothesis that semantic encoding in standard verbal STM tasks is a consequence of controlled, attention-demanding mechanisms of strategic semantic retrieval and encoding. Experiment 1 analysed the effect of presentation rate, with slow presentations being assumed to benefit strategic, time-dependent semantic encoding. Experiments 2 and 3 provided a more direct test of the strategic hypothesis by introducing three different concurrent attention-demanding tasks. Although Experiment 1 showed a larger concreteness effect with slow presentations, the following two experiments yielded strong evidence against the strategic hypothesis. Limiting available attention resources by concurrent tasks reduced global memory performance, but the concreteness effect was equivalent to that found in control conditions. We conclude that semantic effects in STM result from automatic semantic encoding and provide tentative explanations for the interaction between the concreteness effect and the presentation rate.

The effects of control order, feedback, practice, and input device on tracking performance and perceived workload

NASA Technical Reports Server (NTRS)

Hancock, P. A.; Robinson, M. A.

1989-01-01

The present experiment examined the influence of several task-related factors on tracking performance and concomitant workload. The manipulated factors included tracking order, the presence or absence of knowledge of performance, and the control device. Summed root mean square error (rmse) and perceived workload were measured at the termination of each trial. Perceived workload was measured using the NASA Task Load Index (TLX) and the Subjective Workload Assessment Technique (SWAT). Results indicated a large and expected effect for track order on both performance and the perception of load. In general, trackball input was more accurate and judged for lower load than input using a mouse. The presence or absence of knowledge of performance had little effect on either performance or workload. There were a number of interactions between factors shown in performance that were mirrored by perceived workload scores. Results from each workload scale were equivalent in terms of sensitivity to task manipulations. The pattern of results affirm the utility of these workload measures in assessing the imposed load of multiple task-related variables.

Sex Differences and Autism: Brain Function during Verbal Fluency and Mental Rotation

PubMed Central

Minati, Ludovico; Baron-Cohen, Simon; Lombardo, Michael V.; Lai, Meng-Chuan; Walker, Anne; Howard, Dawn; Gray, Marcus A.; Harrison, Neil A.; Critchley, Hugo D.

2012-01-01

Autism spectrum conditions (ASC) affect more males than females. This suggests that the neurobiology of autism: 1) may overlap with mechanisms underlying typical sex-differentiation or 2) alternately reflect sex-specificity in how autism is expressed in males and females. Here we used functional magnetic resonance imaging (fMRI) to test these alternate hypotheses. Fifteen men and fourteen women with Asperger syndrome (AS), and sixteen typically developing men and sixteen typically developing women underwent fMRI during performance of mental rotation and verbal fluency tasks. All groups performed the tasks equally well. On the verbal fluency task, despite equivalent task-performance, both males and females with AS showed enhanced activation of left occipitoparietal and inferior prefrontal activity compared to controls. During mental rotation, there was a significant diagnosis-by-sex interaction across occipital, temporal, parietal, middle frontal regions, with greater activation in AS males and typical females compared to AS females and typical males. These findings suggest a complex relationship between autism and sex that is differentially expressed in verbal and visuospatial domains. PMID:22701630

Measurement of assertive behavior: construct and predictive validity of self-report, role-playing, and in-vivo measures.

PubMed

Burkhart, B R; Green, S B; Harrison, W H

1979-04-01

Examined the predictive validity and construct equivalence of the three major procedures used to measure assertive behavior: Self-report, behavioral role-playing, and in-vivo assessment. Seventy-five Ss, who spanned the range of assertiveness, completed two self-report measures of assertiveness, the Rathus Assertiveness Scale (RAS) and the College Self-Expression Scale (CSES); two scales from the Endler S-R Inventory of General Trait Anxiousness, the interpersonal and general anxiety scales; eight role-playing situations that involved the expression of positive and negative assertiveness; and a telephone in-vivo task. In general, the study revealed the following: (1) assertiveness measures are task-dependent in that there was more overlap within task than between tasks; (2) there is a moderate degree of correspondence between self-report and role-playing measures, although this was true only for negative assertion; (3) positive and negative assertion do not appear to have the same topography of responding; and (4) there appears to be no consistent relationship between the in-vivo measure and any other type of assertiveness measure.

Sex differences and autism: brain function during verbal fluency and mental rotation.

PubMed

Beacher, Felix D C C; Radulescu, Eugenia; Minati, Ludovico; Baron-Cohen, Simon; Lombardo, Michael V; Lai, Meng-Chuan; Walker, Anne; Howard, Dawn; Gray, Marcus A; Harrison, Neil A; Critchley, Hugo D

2012-01-01

Autism spectrum conditions (ASC) affect more males than females. This suggests that the neurobiology of autism: 1) may overlap with mechanisms underlying typical sex-differentiation or 2) alternately reflect sex-specificity in how autism is expressed in males and females. Here we used functional magnetic resonance imaging (fMRI) to test these alternate hypotheses. Fifteen men and fourteen women with Asperger syndrome (AS), and sixteen typically developing men and sixteen typically developing women underwent fMRI during performance of mental rotation and verbal fluency tasks. All groups performed the tasks equally well. On the verbal fluency task, despite equivalent task-performance, both males and females with AS showed enhanced activation of left occipitoparietal and inferior prefrontal activity compared to controls. During mental rotation, there was a significant diagnosis-by-sex interaction across occipital, temporal, parietal, middle frontal regions, with greater activation in AS males and typical females compared to AS females and typical males. These findings suggest a complex relationship between autism and sex that is differentially expressed in verbal and visuospatial domains.

The cardiovascular and metabolic responses to Wii Fit video game playing in middle-aged and older adults.

PubMed

Guderian, B; Borreson, L A; Sletten, L E; Cable, K; Stecker, T P; Probst, M A; Dalleck, L C

2010-12-01

The purpose of this study was (a) to assess the cardiovascular and metabolic responses to Wii Fit video games and (b) to determine if Wii Fit video games meet the American College of Sports Medicine guidelines for improving and maintaining cardiorespiratory fitness. Twenty men and women (mean±SD age, height, and weight: = 58.1±8.8 years, 172.1±10.5 cm, 87.1±22.8 kg, respectively) completed a 20-min Wii Fit testing session consisting of six separate aerobic and balance games. Cardiovascular and metabolic data were collected via a portable calorimetric measurement system. Mean relative exercise intensity was 43.4±16.7% of heart rate reserve. Absolute exercise intensity in metabolic equivalents (METS) was 3.5±0.96. Total net energy expenditure for the Wii Fit video game playing session was 116.2±40.9 kcal/session. Results indicate that playing Wii Fit video games is a feasible alternative to more traditional aerobic exercise modalities for middle-aged and older adults that fulfills the American College of Sports Medicine guidelines for improving and maintaining cardiorespiratory fitness.

Transcriptional Regulation of Aerobic Metabolism in Pichia pastoris Fermentation

PubMed Central

Zhang, Biao; Li, Baizhi; Chen, Dai; Zong, Jie; Sun, Fei; Qu, Huixin; Liang, Chongyang

2016-01-01

In this study, we investigated the classical fermentation process in Pichia pastoris based on transcriptomics. We utilized methanol in pichia yeast cell as the focus of our study, based on two key steps: limiting carbon source replacement (from glycerol to methonal) and fermentative production of exogenous proteins. In the former, the core differential genes in co-expression net point to initiation of aerobic metabolism and generation of peroxisome. The transmission electron microscope (TEM) results showed that yeast gradually adapted methanol induction to increased cell volume, and decreased density, via large number of peroxisomes. In the fermentative production of exogenous proteins, the Gene Ontology (GO) mapping results show that PAS_chr2-1_0582 played a vital role in regulating aerobic metabolic drift. In order to confirm the above results, we disrupted PAS_chr2-1_0582 by homologous recombination. Alcohol consumption was equivalent to one fifth of the normal control, and fewer peroxisomes were observed in Δ0582 strain following methanol induction. In this study we determined the important core genes and GO terms regulating aerobic metabolic drift in Pichia, as well as developing new perspectives for the continued development within this field. PMID:27537181

The transfer of Crel contextual control (same, opposite, less than, more than) through equivalence relations.

PubMed

Perez, William F; Kovac, Roberta; Nico, Yara C; Caro, Daniel M; Fidalgo, Adriana P; Linares, Ila; de Almeida, João Henrique; de Rose, Júlio C

2017-11-01

According to Relational Frame Theory (RFT) C rel denotes a contextual stimulus that controls a particular type of relational response (sameness, opposition, comparative, temporal, hierarchical etc.) in a given situation. Previous studies suggest that contextual functions may be indirectly acquired via transfer of function. The present study investigated the transfer of C rel contextual control through equivalence relations. Experiment 1 evaluated the transfer of C rel contextual functions for relational responses based on sameness and opposition. Experiment 2 extended these findings by evaluating transfer of function using comparative C rel stimuli. Both experiments followed a similar sequence of phases. First, abstract forms were established as C rel stimuli via multiple exemplar training (Phase 1). The contextual cues were then applied to establish arbitrary relations among nonsense words and to test derived relations (Phase 2). After that, equivalence relations involving the original C rel stimuli and other abstract forms were trained and tested (Phase 3). Transfer of function was evaluated by replacing the directly established C rel stimuli with their equivalent stimuli in the former experimental tasks (Phases 1 and 2). Results from both experiments suggest that C rel contextual control may be extended via equivalence relations, allowing other arbitrarily related stimuli to indirectly acquire C rel functions and regulate behavior by evoking appropriate relational responses in the presence of both previously known and novel stimuli. © 2017 Society for the Experimental Analysis of Behavior.

Effects of a meaningful, a discriminative, and a meaningless stimulus on equivalence class formation.

PubMed

Fields, Lanny; Arntzen, Erik; Nartey, Richard K; Eilifsen, Christoffer

2012-03-01

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A-E stimuli were all abstract shapes, none of 10 participants formed classes. When the A, B, D, and E stimuli were abstract shapes and the C stimuli were meaningful pictures, 8 of 10 participants formed classes. This high yield may reflect the expansion of existing classes that consist of the associates of the meaningful stimuli, rather than the formation of the ABCDE classes, per se. When the A-E stimuli were abstract shapes and the C stimuli became S(D)s prior to class formation, 5 out of 10 participants formed classes. Thus, the discriminative functions served by the meaningful stimuli can account for some of the enhancement of class formation produced by the inclusion of a meaningful stimulus as a class member. A sorting task, which provided a secondary measure of class formation, indicated the formation of all three classes when the emergent relations probes indicated the same outcome. In contrast, the sorting test indicated "partial" class formation when the emergent relations test indicated no class formation. Finally, the effects of nodal distance on the relatedness of stimuli in the equivalence classes were not influenced by the functions served by the C stimuli in the equivalence classes.

Effects of a Meaningful, a Discriminative, and a Meaningless Stimulus on Equivalence Class Formation

PubMed Central

Fields, Lanny; Arntzen, Erik; Nartey, Richard K; Eilifsen, Christoffer

2012-01-01

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A–E stimuli were all abstract shapes, none of 10 participants formed classes. When the A, B, D, and E stimuli were abstract shapes and the C stimuli were meaningful pictures, 8 of 10 participants formed classes. This high yield may reflect the expansion of existing classes that consist of the associates of the meaningful stimuli, rather than the formation of the ABCDE classes, per se. When the A–E stimuli were abstract shapes and the C stimuli became SDs prior to class formation, 5 out of 10 participants formed classes. Thus, the discriminative functions served by the meaningful stimuli can account for some of the enhancement of class formation produced by the inclusion of a meaningful stimulus as a class member. A sorting task, which provided a secondary measure of class formation, indicated the formation of all three classes when the emergent relations probes indicated the same outcome. In contrast, the sorting test indicated “partial” class formation when the emergent relations test indicated no class formation. Finally, the effects of nodal distance on the relatedness of stimuli in the equivalence classes were not influenced by the functions served by the C stimuli in the equivalence classes. PMID:22389524

Investigation of nutrient feeding strategies in a countercurrent mixed-acid multi-staged fermentation: experimental data.

PubMed

Smith, Aaron Douglas; Lockman, Nur Ain; Holtzapple, Mark T

2011-06-01

Nutrients are essential for microbial growth and metabolism in mixed-culture acid fermentations. Understanding the influence of nutrient feeding strategies on fermentation performance is necessary for optimization. For a four-bottle fermentation train, five nutrient contacting patterns (single-point nutrient addition to fermentors F1, F2, F3, and F4 and multi-point parallel addition) were investigated. Compared to the traditional nutrient contacting method (all nutrients fed to F1), the near-optimal feeding strategies improved exit yield, culture yield, process yield, exit acetate-equivalent yield, conversion, and total acid productivity by approximately 31%, 39%, 46%, 31%, 100%, and 19%, respectively. There was no statistical improvement in total acid concentration. The traditional nutrient feeding strategy had the highest selectivity and acetate-equivalent selectivity. Total acid productivity depends on carbon-nitrogen ratio.

Cerebral blood flow regulation during cognitive tasks

PubMed Central

Sorond, Farzaneh A.; Schnyer, D.M.; Serrador, J.M.; Milberg, W.P.; Lipsitz, L.A.

2008-01-01

Aging is associated with frontal subcortical microangiopathy and executive cognitive dysfunction, suggesting that elderly individuals may have impaired metabolic activation of cerebral blood flow to the frontal lobes. We used transcranial Doppler (TCD) ultrasound to examine the cerebral blood flow response to executive control and visual tasks in the anterior and posterior cerebral circulations and to determine the effects of healthy aging on cerebral blood flow regulation during cognitive tasks. Continuous simultaneous anterior cerebral artery (ACA) and posterior cerebral artery (PCA) blood flow velocities (BFVs) and mean arterial pressure (MAP) were measured in response to word stem completion (WSC) and a visual search (VS) task in 29 healthy subjects (14 young, 30 ± 1.5 years; 15 old, 74 ± 1.4 years). We found that: (1) ACA and PCA blood flow velocities are both significantly increased during WSC and VS cognitive tasks, (2) ACA and PCA activations were task specific in our young volunteers, with ACA > PCA BFV during the WSC task and PCA > ACA BFV during the VS task, (3) while healthy elderly subjects also had PCA > ACA BFV during the VS task, they did not have ACA > PCA activation during the WSC task, and (4) healthy elderly subjects tend to have overall greater increases in BFV during both cognitive tasks. We conclude that TCD can be used to monitor cerebrovascular hemodynamics during the performance of cognitive tasks. Our data suggest that there is differential blood flow increase in the ACA and PCA in young versus elderly subjects during cognitive tasks. PMID:18387547

MPL’s Research Program in Navy Related Technologies

DTIC Science & Technology

1990-01-01

cracking. Strain gage recordings during sea operations and towing provide a quantitative measurement of stress cycling. After the equivalent of a normal...years exposure to cyclic stresses , FLIP is drydocked for inspection and maintenance. These platforms have been used in a wide variety of tasks, mostly...Various MPL Sponsor Research Activities Date of Program Principal Modification Sponsor Title Investigator Mod 03 NAVOCEANO Crane Support Bishop Mod 05,08