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Sample records for current task demands

  1. The impact of task demand on visual word recognition.

    Science.gov (United States)

    Yang, J; Zevin, J

    2014-07-11

    The left occipitotemporal cortex has been found sensitive to the hierarchy of increasingly complex features in visually presented words, from individual letters to bigrams and morphemes. However, whether this sensitivity is a stable property of the brain regions engaged by word recognition is still unclear. To address the issue, the current study investigated whether different task demands modify this sensitivity. Participants viewed real English words and stimuli with hierarchical word-likeness while performing a lexical decision task (i.e., to decide whether each presented stimulus is a real word) and a symbol detection task. General linear model and independent component analysis indicated strong activation in the fronto-parietal and temporal regions during the two tasks. Furthermore, the bilateral inferior frontal gyrus and insula showed significant interaction effects between task demand and stimulus type in the pseudoword condition. The occipitotemporal cortex showed strong main effects for task demand and stimulus type, but no sensitivity to the hierarchical word-likeness was found. These results suggest that different task demands on semantic, phonological and orthographic processes can influence the involvement of the relevant regions during visual word recognition. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Goal orientation, perceived task outcome and task demands in mathematics tasks: effects on students' attitude in actual task settings.

    Science.gov (United States)

    Seegers, Gerard; van Putten, Cornelis M; de Brabander, Cornelis J

    2002-09-01

    In earlier studies, it has been found that students' domain-specific cognitions and personal learning goals (goal orientation) influence task-specific appraisals of actual learning tasks. The relations between domain-specific and task-specific variables have been specified in the model of adaptive learning. In this study, additional influences, i.e., perceived task outcome on a former occasion and variations in task demands, were investigated. The purpose of this study was to identify personality and situational variables that mediate students' attitude when confronted with a mathematics task. Students worked on a mathematics task in two subsequent sessions. Effects of perceived task outcome at the first session on students' attitude at the second session were investigated. In addition, we investigated how differences in task demands influenced students' attitude. Variations in task demands were provoked by different conditions in task-instruction. In one condition, students were told that the result on the test would add to their mark on mathematics. This outcome orienting condition was contrasted with a task-orienting condition where students were told that the results on the test would not be used to give individual grades. Participants were sixth grade students (N = 345; aged 11-12 years) from 14 primary schools. Multivariate and univariate analyses of (co)variance were applied to the data. Independent variables were goal orientation, task demands, and perceived task outcome, with task-specific variables (estimated competence for the task, task attraction, task relevance, and willingness to invest effort) as the dependent variables. The results showed that previous perceived task outcome had a substantial impact on students' attitude. Additional but smaller effects were found for variation in task demands. Furthermore, effects of previous perceived task outcome and task demands were related to goal orientation. The resulting pattern confirmed that, in general

  3. Learner-Learner Interaction during Collaborative Pragmatic Tasks: The Role of Cognitive and Pragmatic Task Demands

    Science.gov (United States)

    Kim, YouJin; Taguchi, Naoko

    2016-01-01

    Previous task complexity studies have suggested that learners produce more negotiation of meaning opportunities during complex tasks than simple tasks (Robinson, 2011). The present study builds on the existing task complexity literature by examining the impact of task complexity and pragmatic situational demands on the number of learning…

  4. Estimating demand for alternatives to cigarettes with online purchase tasks.

    Science.gov (United States)

    O'Connor, Richard J; June, Kristie M; Bansal-Travers, Maansi; Rousu, Matthew C; Thrasher, James F; Hyland, Andrew; Cummings, K Michael

    2014-01-01

    To explore how advertising affects demand for cigarettes and potential substitutes, including snus, dissolvable tobacco, and medicinal nicotine. A Web-based experiment randomized 1062 smokers to see advertisements for alternative nicotine products or soft drinks, then complete a series of purchase tasks, which were used to estimate demand elasticity, peak consumption, and cross-price elasticity (CPE) for tobacco products. Lower demand elasticity and greater peak consumption were seen for cigarettes compared to all alternative products (p demand. These findings suggest significantly lower demand for alternative nicotine sources among smokers than previously revealed.

  5. Cognitive task demands, self-control demands and the mental well-being of office workers.

    Science.gov (United States)

    Bridger, Robert S; Brasher, Kate

    2011-09-01

    The cognitive task demands of office workers and the self-control demands of their work roles were measured in a sample of 196 employees in two different office layouts using a self-report questionnaire, which was circulated electronically. Multiple linear regression analysis revealed that both factors were associated with mental well-being, but not with physical well-being, while controlling for exposure to psychosocial stressors. The interaction between cognitive task demands and self-control demands had the strongest association with mental well-being, suggesting that the deleterious effect of one was greater when the other was present. An exploratory analysis revealed that the association was stronger for employees working in a large open-plan office than for those working in smaller offices with more privacy. Frustration of work goals was the cognitive task demand having the strongest negative impact on mental well-being. Methodological limitations and scale psychometrics (particularly the use of the NASA Task Load Index) are discussed. STATEMENT OF RELEVANCE: Modern office work has high mental demands and low physical demands and there is a need to design offices to prevent adverse psychological reactions. It is shown that cognitive task demands interact with self-control demands to degrade mental well-being. The association was stronger in an open-plan office.

  6. Disrupting monotony while increasing demand: benefits of rest and intervening tasks on vigilance.

    Science.gov (United States)

    Ralph, Brandon C W; Onderwater, Kris; Thomson, David R; Smilek, Daniel

    2017-03-01

    In the experiments presented here, we examined the impact of intervening tasks on the vigilance decrement. In Experiment 1 participants either (a) continuously performed a visuospatial vigilance task, (b) received a rest break, or (c) temporarily performed a different, demanding visuospatial task in the middle of the vigil. Both taking a rest break and performing the intervening task were found to alleviate the vigilance decrement in response times. Target detection accuracy was equivalent across groups. In Experiment 2 we obtained subjective ratings of task demand, boredom, motivation, and mind wandering for both the vigilance task and intervening task administered in Experiment 1. The intervening task was rated as more demanding in terms of mental demand, physical demand, temporal demand, own performance, effort, and frustration. In addition, participants also reported being more bored, less motivated, and reported mind wandering more frequently when completing the vigil. Disruptions to task monotony (even if cognitively demanding), can alleviate the vigilance decrement. The implications of this finding with respect to current theoretical accounts of the vigilance decrement are discussed.

  7. Hysteresis in Mental Workload and Task Performance: The Influence of Demand Transitions and Task Prioritization.

    Science.gov (United States)

    Jansen, Reinier J; Sawyer, Ben D; van Egmond, René; de Ridder, Huib; Hancock, Peter A

    2016-12-01

    We examine how transitions in task demand are manifested in mental workload and performance in a dual-task setting. Hysteresis has been defined as the ongoing influence of demand levels prior to a demand transition. Authors of previous studies predominantly examined hysteretic effects in terms of performance. However, little is known about the temporal development of hysteresis in mental workload. A simulated driving task was combined with an auditory memory task. Participants were instructed to prioritize driving or to prioritize both tasks equally. Three experimental conditions with low, high, and low task demands were constructed by manipulating the frequency of lane changing. Multiple measures of subjective mental workload were taken during experimental conditions. Contrary to our prediction, no hysteretic effects were found after the high- to low-demand transition. However, a hysteretic effect in mental workload was found within the high-demand condition, which degraded toward the end of the high condition. Priority instructions were not reflected in performance. Online assessment of both performance and mental workload demonstrates the transient nature of hysteretic effects. An explanation for the observed hysteretic effect in mental workload is offered in terms of effort regulation. An informed arrival at the scene is important in safety operations, but peaks in mental workload should be avoided to prevent buildup of fatigue. Therefore, communication technologies should incorporate the historical profile of task demand. © 2016, Human Factors and Ergonomics Society.

  8. Task demands and individual variation in referring expressions

    NARCIS (Netherlands)

    Baltaretu, Adriana-Alexandra; Castro Ferreira, Thiago

    2016-01-01

    Aiming to improve the human-likeness of natural language generation systems, this study investigates different sources of variation that might influence the production of referring expressions (REs), namely the effect of task demands and inter- intra- individual variation. We collected REs using a d

  9. The Effects of Task Demands on Children's Metamemorial Decisions.

    Science.gov (United States)

    Steuck, Kurt W.; Enright, Robert

    Using five metamemory question types and the Counting Span Test (CST), this research investigated the effects of metamemory task demands, and the relationship of the amount of information one can hold in working memory to metamemory question performance. One hundred twenty kindergarten, first, third, and fifth grade children served as subjects.…

  10. Canada - gas supply, demand and current issues

    Energy Technology Data Exchange (ETDEWEB)

    Vollman, K.W. [National Energy Board, Calgary, AB (Canada)

    1996-12-01

    This paper examines the trends in natural gas supply and demand during the decade since deregulation, and provides an assessment of the degree to which the goals of the deregulation agreement have been met. The author then turns to a discussion of current issues in the natural gas industry as seen from a regulator`s perspective. The issues discussed include: excess deliverability and price; pipeline integrity; the Canadian Environmental Assessment Act; new pipeline certification; pipeline jurisdiction; export licensing; financial regulation; and electronic information exchange. (Author)

  11. Selection of spatial reference frames depends on task's demands

    Directory of Open Access Journals (Sweden)

    Greeshma Sharma

    2016-12-01

    Full Text Available Spatial reference frames (SRF are the means of representing spatial relations or locations either in an egocentric coordinate system (centred on navigator or in an allocentric coordinate system (Centred on object. It is necessary to understand when and how spatial representation switches between allocentric and egocentric reference frames in context to spatial tasks. The objective of this study was to explore if the elementary spatial representation does exist, whether it would remain consistent or change under the influence of a task's demand. Also, we explored how the SRF would assist if the environment is enriched with landmarks, having multiple routes for wayfinding. The results showed that the switching of SRF depends not only on the default representation but also on a task's demand. They also demonstrated that participants who were using allocentric representation performed better in the presence of landmarks.

  12. Enhancing perceptual and attentional skills requires common demands between the action video games and transfer tasks.

    Science.gov (United States)

    Oei, Adam C; Patterson, Michael D

    2015-01-01

    Despite increasing evidence that shows action video game play improves perceptual and cognitive skills, the mechanisms of transfer are not well-understood. In line with previous work, we suggest that transfer is dependent upon common demands between the game and transfer task. In the current study, participants played one of four action games with varying speed, visual, and attentional demands for 20 h. We examined whether training enhanced performance for attentional blink, selective attention, attending to multiple items, visual search and auditory detection. Non-gamers who played the game (Modern Combat) with the highest demands showed transfer to tasks of attentional blink and attending to multiple items. The game (MGS Touch) with fewer attentional demands also decreased attentional blink, but to a lesser degree. Other games failed to show transfer, despite having many action game characteristics but at a reduced intensity. The results support the common demands hypothesis.

  13. Blocking-out auditory distracters while driving : A cognitive strategy to reduce task-demands on the road

    NARCIS (Netherlands)

    Unal, Ayca Berfu; Platteel, Samantha; Steg, Linda; Epstude, Kai

    2013-01-01

    The current research examined how drivers handle task-demands induced by listening to the radio while driving. In particular, we explored the traces of a possible cognitive strategy that might be used by drivers to cope with task-demands, namely blocking-out auditory distracters. In Study 1 (N = 15)

  14. Blocking-out auditory distracters while driving : A cognitive strategy to reduce task-demands on the road

    NARCIS (Netherlands)

    Unal, Ayca Berfu; Platteel, Samantha; Steg, Linda; Epstude, Kai

    The current research examined how drivers handle task-demands induced by listening to the radio while driving. In particular, we explored the traces of a possible cognitive strategy that might be used by drivers to cope with task-demands, namely blocking-out auditory distracters. In Study 1 (N =

  15. The effect of task demand and incentive on neurophysiological and cardiovascular markers of effort.

    Science.gov (United States)

    Fairclough, Stephen H; Ewing, Kate

    2017-09-01

    According to motivational intensity theory, effort is proportional to the level of task demand provided that success is possible and successful performance is deemed worthwhile. The current study represents a simultaneous manipulation of demand (working memory load) and success importance (financial incentive) to investigate neurophysiological (EEG) and cardiovascular measures of effort. A 2×2 repeated-measures study was conducted where 18 participants performed a n-back task under three conditions of demand: easy (1-back), hard (4-back) and very hard (7-back). In addition, participants performed these tasks in the presence of performance-contingent financial incentive or in a no-incentive (pilot trial) condition. Three bands of EEG activity were quantified: theta (4-7Hz), lower-alpha (7.5-10Hz) and upper-alpha (10.5-13Hz). Fronto-medial activity in the theta band and activity in the upper-alpha band at frontal, central and parietal sites were sensitive to demand and indicated greatest effort when the task was challenging and success was possible. Mean systolic blood pressure and activity in the lower-alpha band at parietal sites were also sensitive to demand but also increased in the incentive condition across all levels of task demand. The results of the study largely support the predictions of motivational intensity using neurophysiological markers of effort. Copyright © 2017. Published by Elsevier B.V.

  16. The Effect of Task Demands on Attention Allocation in Children of Different Ages.

    Science.gov (United States)

    Schiff, Andrew R.; Knopf, Irwin J.

    1985-01-01

    In a study of the effect of task demands on attention allocation, 20 9-year-olds and 20 13-year-olds were presented with a primary and a secondary task. Subjects were instructed either to respond to the primary task or to respond to both tasks. Overall, findings indicate that ability to allocate attention in accordance with task demands improves…

  17. Neglect and extinction depend greatly on task demands: A review

    Directory of Open Access Journals (Sweden)

    Mario eBonato

    2012-07-01

    Full Text Available This review illustrates how, after unilateral brain damage, the presence and severity of spatial awareness deficits for the contralesional hemispace depend greatly on the quantity of attentional resources available for performance. After a brief description of neglect and extinction, different frameworks accounting for spatial and non-spatial attentional processes will be outlined. The central part of the review will describe how the performance of brain damaged patients is negatively affected by increased task demands, which can result in the emergence of severe awareness deficits for contralesional space even in patients who perform normally on paper-and-pencil tests. Throughout the review neglect is described as a spatial syndrome that can be exacerbated in the presence and severity by both spatial and non-spatial tasks. The take-home message is that the presence and degree of contralesional neglect and extinction can be dramatically overlooked based on standard paper-and-pencil testing, where patients can easily compensate for their deficits. Only tasks where compensation is made impossible represent an appropriate approach to detect these disabling contralesional deficits of awareness that become subtle in post-acute stroke phases.

  18. Attention Modifies Spatial Resolution According to Task Demands.

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    Barbot, Antoine; Carrasco, Marisa

    2017-03-01

    How does visual attention affect spatial resolution? In texture-segmentation tasks, exogenous (involuntary) attention automatically increases resolution at the attended location, which improves performance where resolution is too low (at the periphery) but impairs performance where resolution is already too high (at central locations). Conversely, endogenous (voluntary) attention improves performance at all eccentricities, which suggests a more flexible mechanism. Here, using selective adaptation to spatial frequency, we investigated the mechanism by which endogenous attention benefits performance in resolution tasks. Participants detected a texture target that could appear at several eccentricities. Adapting to high or low spatial frequencies selectively affected performance in a manner consistent with changes in resolution. Moreover, adapting to high, but not low, frequencies mitigated the attentional benefit at central locations where resolution was too high; this shows that attention can improve performance by decreasing resolution. Altogether, our results indicate that endogenous attention benefits performance by modulating the contribution of high-frequency information in order to flexibly adjust spatial resolution according to task demands.

  19. Estimating Demand and Cross-Price Elasticity for Very Low Nicotine Content (VLNC) Cigarettes Using a Simulated Demand Task.

    Science.gov (United States)

    Tucker, Megan R; Laugesen, Murray; Grace, Randolph C

    2017-03-03

    Very Low Nicotine Content (VLNC) cigarettes might be useful as part of a tobacco control strategy, but relatively little is known about their acceptability as substitutes for regular cigarettes. We compared subjective effects and demand for regular cigarettes and Very Low Nicotine Content (VLNC) cigarettes, and estimated cross-price elasticity for VLNC cigarettes, using simulated demand tasks. 40 New Zealand smokers sampled a VLNC cigarette and completed Cigarette Purchase Tasks to indicate their demand for regular cigarettes and VLNC cigarettes at a range of prices, and a cross-price task indicating how many regular cigarettes and VLNC cigarettes they would purchase at 0.5x, 1x, and 2x the current market price for regular cigarettes, assuming the price of VLNC cigarettes remained constant. They also rated the subjective effects of the VLNC cigarette and their usual-brand regular cigarettes. Cross-price elasticity for VLNC cigarettes was estimated as 0.24 and was significantly positive, indicating that VLNC cigarettes are partially substitutable for regular cigarettes. VLNC cigarettes were rated as less satisfying and psychologically rewarding than regular cigarettes, but this was unrelated to demand or substitutability. VLNC cigarettes are potentially substitutable for regular cigarettes. Their availability may reduce tobacco consumption, nicotine intake and addiction; making it easier for smokers to quit. VLNC cigarettes share the behavioural and sensory components of smoking whilst delivering negligible levels of nicotine. Although smokers rated VLNCs as less satisfying than regular cigarettes, smokers said they would increase their consumption of VLNCs as the price of regular cigarettes increased, if VLNCs were available at a lower price. This suggests that VLNCs are partially substitutable for regular cigarettes. VLNCs can be part of an effective tobacco control strategy, by reducing nicotine dependence and improving health and financial outcomes for smokers.

  20. Variation at work: alternations between physically and mentally demanding tasks in blue-collar occupations.

    Science.gov (United States)

    Jahncke, Helena; Hygge, Staffan; Mathiassen, Svend Erik; Hallman, David; Mixter, Susanna; Lyskov, Eugene

    2017-09-01

    The aims of this questionnaire study were to describe the occurrence and desired number of alternations between mental and physical tasks in industrial and non-industrial blue-collar work, and determine to which extent selected personal and occupational factors influence these conditions. On average, the 122 participating workers (55 females) reported to have close to four alternations per day between mental and physical tasks, and to desire more alternations than they actually had. They also expressed a general preference for performing a physical task after a mental task and vice versa. In univariate regression models, the desired change in task alternations was significantly associated with gender, age, occupation, years with current work tasks and perceived job control, while occupation was the only significant determinant in a multiple regression model including all factors. Our results suggest that alternations between productive physical and mental tasks could be a viable option in future job rotation. Practitioner Summary: We addressed attitudes among blue-collar workers to alternations between physically and mentally demanding tasks. More alternations were desired than those occurring in the job, and workers preferred performing a physical task after a mental and vice versa. Alternating physical and mental tasks could, thus, be a viable option in job rotation.

  1. A Demands-Resources Model of Work Pressure in IT Student Task Groups

    Science.gov (United States)

    Wilson, E. Vance; Sheetz, Steven D.

    2010-01-01

    This paper presents an initial test of the group task demands-resources (GTD-R) model of group task performance among IT students. We theorize that demands and resources in group work influence formation of perceived group work pressure (GWP) and that heightened levels of GWP inhibit group task performance. A prior study identified 11 factors…

  2. Sleep-dependent motor memory consolidation in older adults depends on task demands.

    Science.gov (United States)

    Gudberg, Christel; Wulff, Katharina; Johansen-Berg, Heidi

    2015-03-01

    It is often suggested that sleep-dependent consolidation of motor learning is impaired in older adults. The current study challenges this view and suggests that the degree of motor consolidation seen with sleep in older age groups depends on the kinematic demands of the task. We show that, when tested with a classic sequence learning task, requiring individuated finger movements, older adults did not show sleep-dependent consolidation. By contrast, when tested with an adapted sequence learning task, in which movements were performed with the whole hand, sleep-dependent motor improvement was observed in older adults. We suggest that age-related decline in fine motor dexterity may in part be responsible for the previously described deficit in sleep-dependent motor consolidation with aging.

  3. Aging and Concurrent Task Performance: Cognitive Demand and Motor Control

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    Albinet, Cedric; Tomporowski, Phillip D.; Beasman, Kathryn

    2006-01-01

    A motor task that requires fine control of upper limb movements and a cognitive task that requires executive processing--first performing them separately and then concurrently--was performed by 18 young and 18 older adults. The motor task required participants to tap alternatively on two targets, the sizes of which varied systematically. The…

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

    Science.gov (United States)

    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.

  5. The influence of task demand and learning on the psychophysiological response.

    Science.gov (United States)

    Fairclough, Stephen H; Venables, Louise; Tattersall, Andrew

    2005-05-01

    The level of expertise of an operator may significantly influence his/her psychophysiological response to high task demand. A naive individual may invest considerable mental effort during performance of a difficult task and psychophysiological reactivity will be high compared to the psychophysiological response of a highly skilled operator. A study on multitasking performance was conducted to investigate the interaction between learning and task demand on psychophysiological reactivity. Thirty naive participants performed high and low demand versions of the Multi-attribute Task Battery (MATB) over a learning period of 64 min. High and low task demand setting were preset via a pilot study. Psychophysiological variables were collected from four channels of EEG (Cz, P3, P4, Pz), ECG, EOG and respiration rate to measure the impact of task demand and learning. Several variables were sensitive to the task demand manipulation but not time-on-task, e.g., heart rate, Theta activity at parietal sites. The sensitivity of certain variables to high demand was compromised by skill acquisition, e.g., respiration rate, suppression of alpha activity. A sustained learning effect was observed during the high demand condition only; multiple regression analyses revealed that specific psychophysiological variables predicted learning at different stages on the learning curve. The implications for the sensitivity of psychophysiological variables are discussed.

  6. Cardiac responsiveness to attention-demanding tasks in socially maladaptive children

    NARCIS (Netherlands)

    Althaus, M; Aarnoudse, CC; Minderaa, RB; Mulder, Gysbertus; Mulder, Lambertus

    Cardiac responsiveness to attention-demanding tasks in socially maladaptive children A psychofysiological study of the cardiac adaptivity to attention-demanding reaction time tasks demonstrated that children with a lesser variant of the pervasive developmental disorder (DSM-IV: PDDNOS) exhibit less

  7. Cardiac responsiveness to attention-demanding tasks in socially maladaptive children

    NARCIS (Netherlands)

    Althaus, M; Aarnoudse, CC; Minderaa, RB; Mulder, Gysbertus; Mulder, Lambertus

    1999-01-01

    Cardiac responsiveness to attention-demanding tasks in socially maladaptive children A psychofysiological study of the cardiac adaptivity to attention-demanding reaction time tasks demonstrated that children with a lesser variant of the pervasive developmental disorder (DSM-IV: PDDNOS) exhibit less

  8. Skills-demands compatibility as a determinant of flow experience in an inductive reasoning task.

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    Schiefele, Ulrich; Raabe, Andreas

    2011-10-01

    The skills-demands fit hypothesis of flow theory was examined. Based on the earlier finding that high demands in a game situation do not reduce the experience of flow, a cognitive task paradigm was used. The effect of skills-demands compatibility on the experience of flow but not of other, similar psychological states (i.e., concentration, negative and positive activation) was also investigated. Participants were 89 undergraduate students who worked on a number of inductive reasoning tasks in four successive trials with or without skills-demands compatibility. The results clearly supported the skills-demands fit hypothesis; concentration and activation were affected only by the tasks' difficulty. Inductive reasoning tasks are a useful tool for the experimental analysis of flow, and skills-demands compatibility is a significant and powerful condition of flow, but not of other, similar psychological states.

  9. Effect of aging on performance, muscle activation and perceived stress during mentally demanding computer tasks

    DEFF Research Database (Denmark)

    Alkjaer, Tine; Pilegaard, Marianne; Bakke, Merete

    2005-01-01

    OBJECTIVES: This study examined the effects of age on performance, muscle activation, and perceived stress during computer tasks with different levels of mental demand. METHODS: Fifteen young and thirteen elderly women performed two computer tasks [color word test and reference task] with different...... demands affect young and elderly women differently. Thus the mentally demanding computer task had a more pronounced effect on the elderly than on the young. In contrast to the results in the reference task, the same level of muscle activity for most muscles and the same level of self-reported difficulty...... levels of mental demand but similar physical demands. The performance (clicking frequency, percentage of correct answers, and response time for correct answers) and electromyography from the forearm, shoulder, and neck muscles were recorded. Visual analogue scales were used to measure the participants...

  10. Mathematics Teachers' Enactment of Cognitively Demanding Tasks: Investigating Links to Teachers' Knowledge and Conceptions

    Science.gov (United States)

    Wilhelm, Anne Garrison

    2014-01-01

    This study sought to understand how aspects of middle school mathematics teachers' knowledge and conceptions are related to their enactment of cognitively demanding tasks. I defined the enactment of cognitively demanding tasks to involve task selection and maintenance of the cognitive demand of high-level tasks and examined those two…

  11. Perceptual demand modulates activation of human auditory cortex in response to task-irrelevant sounds.

    Science.gov (United States)

    Sabri, Merav; Humphries, Colin; Verber, Matthew; Mangalathu, Jain; Desai, Anjali; Binder, Jeffrey R; Liebenthal, Einat

    2013-09-01

    In the visual modality, perceptual demand on a goal-directed task has been shown to modulate the extent to which irrelevant information can be disregarded at a sensory-perceptual stage of processing. In the auditory modality, the effect of perceptual demand on neural representations of task-irrelevant sounds is unclear. We compared simultaneous ERPs and fMRI responses associated with task-irrelevant sounds across parametrically modulated perceptual task demands in a dichotic-listening paradigm. Participants performed a signal detection task in one ear (Attend ear) while ignoring task-irrelevant syllable sounds in the other ear (Ignore ear). Results revealed modulation of syllable processing by auditory perceptual demand in an ROI in middle left superior temporal gyrus and in negative ERP activity 130-230 msec post stimulus onset. Increasing the perceptual demand in the Attend ear was associated with a reduced neural response in both fMRI and ERP to task-irrelevant sounds. These findings are in support of a selection model whereby ongoing perceptual demands modulate task-irrelevant sound processing in auditory cortex.

  12. Stimulus selectivity of drug purchase tasks: A preliminary study evaluating alcohol and cigarette demand.

    Science.gov (United States)

    Strickland, Justin C; Stoops, William W

    2017-06-01

    The use of drug purchase tasks to measure drug demand in human behavioral pharmacology and addiction research has proliferated in recent years. Few studies have systematically evaluated the stimulus selectivity of drug purchase tasks to demonstrate that demand metrics are specific to valuation of or demand for the commodity under study. Stimulus selectivity is broadly defined for this purpose as a condition under which a specific stimulus input or target (e.g., alcohol, cigarettes) is the primary determinant of behavior (e.g., demand). The overall goal of the present study was to evaluate the stimulus selectivity of drug purchase tasks. Participants were sampled from the Amazon.com's crowdsourcing platform Mechanical Turk. Participants completed either alcohol and soda purchase tasks (Experiment 1; N = 139) or cigarette and chocolate purchase tasks (Experiment 2; N = 46), and demand metrics were compared to self-reported use behaviors. Demand metrics for alcohol and soda were closely associated with commodity-similar (e.g., alcohol demand and weekly alcohol use) but not commodity-different (e.g., alcohol demand and weekly soda use) variables. A similar pattern was observed for cigarette and chocolate demand, but selectivity was not as consistent as for alcohol and soda. Collectively, we observed robust selectivity for alcohol and soda purchase tasks and modest selectivity for cigarette and chocolate purchase tasks. These preliminary outcomes suggest that demand metrics adequately reflect the specific commodity under study and support the continued use of purchase tasks in substance use research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  13. The Impact of Task Demands on Fixation-Related Brain Potentials during Guided Search

    Science.gov (United States)

    Ahrens, Barry; Connolly, Patrick

    2016-01-01

    Recording synchronous data from EEG and eye-tracking provides a unique methodological approach for measuring the sensory and cognitive processes of overt visual search. Using this approach we obtained fixation related potentials (FRPs) during a guided visual search task specifically focusing on the lambda and P3 components. An outstanding question is whether the lambda and P3 FRP components are influenced by concurrent task demands. We addressed this question by obtaining simultaneous eye-movement and electroencephalographic (EEG) measures during a guided visual search task while parametrically modulating working memory load using an auditory N-back task. Participants performed the guided search task alone, while ignoring binaurally presented digits, or while using the auditory information in a 0, 1, or 2-back task. The results showed increased reaction time and decreased accuracy in both the visual search and N-back tasks as a function of auditory load. Moreover, high auditory task demands increased the P3 but not the lambda latency while the amplitude of both lambda and P3 was reduced during high auditory task demands. The results show that both early and late stages of visual processing indexed by FRPs are significantly affected by concurrent task demands imposed by auditory working memory. PMID:27286248

  14. A Comparison of Two Task Rating Scales of Physical Demand.

    Science.gov (United States)

    1986-08-01

    Research Report 3/86 0 r=CG RISON OF TwO TASK RATING SCALES CF PHYSICAL CEMAND by Major Robert S. Collyer Commonwealth of Autralia ! August 19g86 This...analysis system . because the wording of the anchor points for the PSE scale made reference to specific weights and heights, it was judged to be an...Air Force Occupational ’,easurement Center. Lindquist, E. F. (1953). Design and analysis of experiments in psychology and education . Boston, l,1A

  15. Trial-to-trial reoptimization of motor behavior due to changes in task demands is limited.

    Directory of Open Access Journals (Sweden)

    Orban de Xivry J-J

    Full Text Available Each task requires a specific motor behavior that is tuned to task demands. For instance, writing requires a lot of accuracy while clapping does not. It is known that the brain adjusts the motor behavior to different task demands as predicted by optimal control theory. In this study, the mechanism of this reoptimization process is investigated by varying the accuracy demands of a reaching task. In this task, the width of the reaching target (0.5 or 8 cm was varied either on a trial-to-trial basis (random schedule or in blocks (blocked schedule. On some trials, the hand of the subjects was clamped to a rectilinear trajectory that ended 2 cm on the left or right of the target center. The rejection of this perturbation largely varied with target width in the blocked schedule but not in the random schedule. That is, subjects exhibited different motor behavior in the different schedules despite identical accuracy demands. Therefore, while reoptimization has been considered immediate and automatic, the differences in motor behavior observed across schedules suggest that the reoptimization of the motor behavior is neither happening on a trial-by-trial basis nor obligatory. The absence of trial-to-trial mechanisms, the inability of the brain to adapt to two conflicting task demands and the existence of a switching cost are discussed as possible sources of the non-optimality of motor behavior during the random schedule.

  16. Stress reactions to cognitively demanding tasks and open-plan office noise

    DEFF Research Database (Denmark)

    Kristiansen, Jesper; Mathiesen, Line; Nielsen, Pernille Kofoed

    2009-01-01

    OBJECTIVES: To investigate the effects of cognitively demanding work tasks and office noise on heart rate variability (HRV), cardiovascular responses and electromyography (EMG) activity in the trapezius muscles. METHODS: Ten female volunteers were exposed to simulated open-plan office noise for 35...... min (Leq 65 dBA), while engaged in cognitively demanding tasks. Task performance, self-rated stress and energy, affective state, perceived exertion in the shoulders and in the head, EMG in the left and right trapezius muscle, blood pressure, heart period length, HRV, and salivary cortisol were...... measured. RESULTS: Cognitively demanding work tasks were associated with changes in HRV, systolic blood pressure and EMG that reflects increased sympathetic activity in the autonomic nervous system. No effect of noise was observed, except for a higher rating of perceived exertion in the head and, contrary...

  17. Task parameters affecting ergonomic demands and productivity of HVAC duct installation.

    Science.gov (United States)

    Mitropoulos, Panagiotis; Hussain, Sanaa; Guarascio-Howard, Linda; Memarian, Babak

    2014-01-01

    Mechanical installation workers experience work-related musculoskeletal disorders (WMSDs) at high rates. (1) Quantify the ergonomic demands during HVAC installation, (2) identify the tasks and task parameters that generated extreme ergonomic demands, and (3) propose improvements to reduce the WMSDs among mechanical workers. The study focused on installation of rectangular ductwork components using ladders, and analyzed five operations by two mechanical contractors. Using continuous time observational assessment, the videotaped operations were analyzed along two dimensions: (1) the production tasks and durations, and (2) the ergonomic demands for four body regions (neck, arms/shoulders, back, and knees). The analysis identified tasks with low portion of productive time and high portion of extreme postures, and task parameters that generated extreme postures. Duct alignment was the task with the highest portion of extreme postures. The position of the ladder (angle and distance from the duct) was a task parameter that strongly influenced the extreme postures for back, neck and shoulders. Other contributing factors included the difficulty to reach the hand tools when working on the ladder, the congestion of components in the ceiling, and the space between the duct and the ceiling. The identified tasks and factors provide directions for improvement.

  18. Integrating Markets to Bridge Supply and Demand for Knowledge Intensive Tasks

    Science.gov (United States)

    Overbeek, Sietse; Janssen, Marijn; van Bommel, Patrick

    The advent of the knowledge-based economy has underlined the importance of intellectual capital that is possessed by knowledge intensive organizations. Three general observations of knowledge intensive work produced by actors working in such organizations served as the basis for the initiation of this research. First, knowledge intensive tasks become increasingly complex. Second, actors that perform such tasks experience an increase in cognitive load. Third, the desired quality of task performance and the produced task results are at stake due to the aforementioned two developments. In this research we investigate how supply and demand of intangible assets such as knowledge, cognitive characteristics, and quality factors can be matched based on market mechanisms.

  19. Why Advice on Task Selection May Hamper Learning in On-Demand Education

    NARCIS (Netherlands)

    Taminiau, Bettine; Kester, Liesbeth; Corbalan, Gemma; Alessi, Steve; Moxnes, Erling; Gijselaers, Wim; Kirschner, Paul A.; Van Merriënboer, Jeroen

    2013-01-01

    Taminiau, E. M. C., Kester, L., Corbalan, G., Alessi, S. M., Moxnes, E., Gijselaers, W. H., Kirschner, P. A., & Van Merriënboer, J. J. G. (2013). Why advice on task selection may hamper learning in on-demand education. Computers in Human Behavior, 29, 145-154. doi: 10.1016/j.chb.2012.07.028

  20. Disentangling longitudinal relations between physical activity, work-related fatigue, and task demands

    NARCIS (Netherlands)

    Vries, J.D. de; Claessens, B.J.C.; Hooff, M.L.M. van; Geurts, S.A.E.; Bossche, S.N.J. van den; Kompier, A.J.

    2016-01-01

    Purpose This longitudinal study examined ‘normal’, ‘reversed’, and ‘reciprocal’ relationships between (1) physical activity and work-related fatigue; and (2) physical activity and task demands. Furthermore, the effects of across-time change in meaningful physical activity groups on levels of

  1. Combined Task and Physical Demands Analyses towards a Comprehensive Human Work Model

    Science.gov (United States)

    2014-09-01

    velocities, and accelerations over time for each postural sequence. Neck strain measures derived from biomechanical analyses of these postural...and whole missions. The result is a comprehensive model of tasks and associated physical demands from which one can estimate the accumulative neck ...Griffon Helicopter aircrew (Pilots and Flight Engineers) reported neck pain particularly when wearing Night Vision Goggles (NVGs) (Forde et al. , 2011

  2. Dissociating sentential prosody from sentence processing: activation interacts with task demands.

    Science.gov (United States)

    Plante, Elena; Creusere, Marlena; Sabin, Cynthia

    2002-09-01

    Sentence processing was contrasted with processing of syntactic prosody under two task conditions in order to examine the representation of these components of language and their interaction with working memory load. Twelve adults received fMDI scans while they listened to low-pass filtered and unfiltered sentences either passively, or during tasks that required subjects to remember and recognize information contained in the stimuli. Results indicated that temporal activation for prosodic stimuli differed compared to activation for sentence stimuli only during passive listening tasks. The inclusion of memory demands was associated with frontal activation, which was differentially lateralized for sentence and prosodic stimuli. The results demonstrate differential brain activation for prosodic vs sentential stimuli which interacts with the memory demands placed on the subjects.

  3. Reconfiguration of the Brain Functional Network Associated with Visual Task Demands.

    Science.gov (United States)

    Wen, Xue; Zhang, Delong; Liang, Bishan; Zhang, Ruibin; Wang, Zengjian; Wang, Junjing; Liu, Ming; Huang, Ruiwang

    2015-01-01

    Neuroimaging studies have demonstrated that the topological properties of resting-state brain functional networks are modulated through task performances. However, the reconfiguration of functional networks associated with distinct degrees of task demands is not well understood. In the present study, we acquired fMRI data from 18 healthy adult volunteers during resting-state (RS) and two visual tasks (i.e., visual stimulus watching, VSW; and visual stimulus decision, VSD). Subsequently, we constructed the functional brain networks associated with these three conditions and analyzed the changes in the topological properties (e.g., network efficiency, wiring-cost, modularity, and robustness) among them. Although the small-world attributes were preserved qualitatively across the functional networks of the three conditions, changes in the topological properties were also observed. Compared with the resting-state, the functional networks associated with the visual tasks exhibited significantly increased network efficiency and wiring-cost, but decreased modularity and network robustness. The changes in the task-related topological properties were modulated according to the task complexity (i.e., from RS to VSW and VSD). Moreover, at the regional level, we observed that the increased nodal efficiencies in the visual and working memory regions were positively associated with the increase in task complexity. Together, these results suggest that the increased efficiency of the functional brain network and higher wiring-cost were observed to afford the demands of visual tasks. These observations provide further insights into the mechanisms underlying the reconfiguration of the brain network during task performance.

  4. Steering Demands Diminish the Early-P3, Late-P3 and RON Components of the Event-Related Potential of Task-Irrelevant Environmental Sounds.

    Science.gov (United States)

    Scheer, Menja; Bülthoff, Heinrich H; Chuang, Lewis L

    2016-01-01

    The current study investigates the demands that steering places on mental resources. Instead of a conventional dual-task paradigm, participants of this study were only required to perform a steering task while task-irrelevant auditory distractor probes (environmental sounds and beep tones) were intermittently presented. The event-related potentials (ERPs), which were generated by these probes, were analyzed for their sensitivity to the steering task's demands. The steering task required participants to counteract unpredictable roll disturbances and difficulty was manipulated either by adjusting the bandwidth of the roll disturbance or by varying the complexity of the control dynamics. A mass univariate analysis revealed that steering selectively diminishes the amplitudes of early P3, late P3, and the re-orientation negativity (RON) to task-irrelevant environmental sounds but not to beep tones. Our findings are in line with a three-stage distraction model, which interprets these ERPs to reflect the post-sensory detection of the task-irrelevant stimulus, engagement, and re-orientation back to the steering task. This interpretation is consistent with our manipulations for steering difficulty. More participants showed diminished amplitudes for these ERPs in the "hard" steering condition relative to the "easy" condition. To sum up, the current work identifies the spatiotemporal ERP components of task-irrelevant auditory probes that are sensitive to steering demands on mental resources. This provides a non-intrusive method for evaluating mental workload in novel steering environments.

  5. Science teachers' learning to notice from video cases of the enactment of cognitively demanding instructional tasks

    Science.gov (United States)

    Kisa, Miray Tekkumru

    Members of a profession develop a professional vision that enables them to see and understand complex situations in particular ways. This study focuses on developing science teachers' professional vision by supporting their learning to attend to particular classroom interactions and make sense of them in particular ways. Specifically, this study investigated high school biology teachers' learning to notice in a professional development (PD) setting from video cases that depict classroom interactions during the enactment of high-level, cognitively demanding science tasks. A seven-session, video-based PD intervention in which teachers analyzed short video clips that illustrated students' engagement with cognitively demanding tasks was designed and implemented. The findings focused on changes in teacher noticing from pre- to post-PD as revealed through the analysis of two sets of baseline and exit interviews with each individual teacher as well as the analysis of particular PD sessions. According to the findings, there were mostly significant changes in what teachers attended to in the video cases and how they made sense of what they saw. In addition, there was a shift towards connecting the specifics of what they noticed in the video cases to the level or kind of student thinking as outlined in the Task Analysis Guide in Science framework. The findings are promising in terms of developing science teachers' professional vision of classroom interactions during the enactment of cognitively demanding tasks. The study findings provide implications for designing effective PD programs to support teachers' professional vision.

  6. Change in Thinking Demands for Students Across the Phases of a Science Task: An Exploratory Study

    Science.gov (United States)

    Tekkumru-Kisa, Miray; Schunn, Christian; Stein, Mary Kay; Reynolds, Bertha

    2017-08-01

    Science education communities around the world have increasingly emphasized engaging students in the disciplinary practices of science as they engage in high levels of reasoning about scientific ideas. Consistently, this is a critical moment in time in the USA as it goes through a new wave of science education reform within the context of Next Generation Science Standards (NGSS). We argue that the placement of high demands on students' thinking (i.e., a high level of thinking) in combination with positioning students to use disciplinary practices as they try to make sense of scientific ideas (i.e., a deep kind of thinking) constitute critical aspects of the reform. The main purpose of this paper is to identify and describe the kinds and levels of thinking in which students engage when they are invited to think and reason as demanded by NGSS-aligned curricular tasks. Our analysis of video records of classrooms in which an NGSS-aligned, cognitively demanding task was used, revealed many ways in which the aspirational level and kind of student thinking will not be met in many science classrooms. We propose a way of characterizing and labeling the differences among these kinds and levels of thinking during the implementation of a reform-based biology curriculum. These categories, which focus on two important features emphasized in the NGSS, can help us to better understand, diagnose, and communicate issues during the implementation of high-level tasks in science classrooms.

  7. Investigating the Effects of Concurrent Performance of Physical and Cognitive Demanding Task in Paced Assembly Lines

    Directory of Open Access Journals (Sweden)

    Shakil Ahmed Shaikh

    2013-07-01

    Full Text Available The study was undertaken to investigate the effects of pacing on aspects of performance at an assembly task and on the operators' responses related to work behaviour, perceived workload and perceived stress. A particular objective of the study was to investigate whether physical and cognitive demands may interact in their influences on these effects. An assembly task was simulated in the laboratory and the level of pacing imposed, work height and memory load within the task were all varied. The results showed that the type of pacing commonly imposed (as is common with a lean manufacturing Takt time system in industry can significantly affect both performance and perceived workload and stress. Physical demands (through work height affecting posture and mental demand (through memory load were also found to have significant effects, as would be expected from the many studies of these in the literature. More importantly, some interactions were found between pacing and work height in their effects on quality of assembly and the operator's own rating of performance, and between work height and memory load in their effects on errors. These findings will need to be taken into account by companies when implementing Takt time systems.

  8. Executive functioning in preschoolers: reducing the inhibitory demands of the dimensional change card sort task.

    Science.gov (United States)

    Rennie, David A C; Bull, Rebecca; Diamond, Adele

    2004-01-01

    To investigate the role of inhibitory control in preschoolers' ability to switch sets, 3 conditions of the Dimensional Change Card Sort task ( Zelazo, Reznick, & Pinon, 1995) were tested. In Condition B (novel response options, standard stimuli) action inhibition was reduced, but the need for attentional inhibition was maintained. In Condition C (novel stimuli, standard response options) demands on both action and attentional inhibition were reduced. Performance in these was compared to that in the standard condition (A). Rule complexity was comparable across conditions. All 21 children who passed preswitch (average age 37 months) were tested on all postswitch conditions, order counterbalanced. Although reducing demands on action inhibition (Condition B) did not significantly improve performance, when demands on both action and attentional inhibition were reduced (Condition C) almost all children (95%) successfully switched sets (even children only 2 1/2 years old). Inadequate inhibition (of attention alone or both attention and action) appears sufficient to account for virtually all errors by preschoolers on this card sorting task.

  9. Ventrolateral prefrontal cortex and the effects of task demand context on facial affect appraisal in schizophrenia.

    Science.gov (United States)

    Leitman, David I; Wolf, Daniel H; Loughead, James; Valdez, Jeffrey N; Kohler, Christian G; Brensinger, Colleen; Elliott, Mark A; Turetsky, Bruce I; Gur, Raquel E; Gur, Ruben C

    2011-01-01

    Schizophrenia patients display impaired performance and brain activity during facial affect recognition. These impairments may reflect stimulus-driven perceptual decrements and evaluative processing abnormalities. We differentiated these two processes by contrasting responses to identical stimuli presented under different contexts. Seventeen healthy controls and 16 schizophrenia patients performed an fMRI facial affect detection task. Subjects identified an affective target presented amongst foils of differing emotions. We hypothesized that targeting affiliative emotions (happiness, sadness) would create a task demand context distinct from that generated when targeting threat emotions (anger, fear). We compared affiliative foil stimuli within a congruent affiliative context with identical stimuli presented in an incongruent threat context. Threat foils were analysed in the same manner. Controls activated right orbitofrontal cortex (OFC)/ventrolateral prefrontal cortex (VLPFC) more to affiliative foils in threat contexts than to identical stimuli within affiliative contexts. Patients displayed reduced OFC/VLPFC activation to all foils, and no activation modulation by context. This lack of context modulation coincided with a 2-fold decrement in foil detection efficiency. Task demands produce contextual effects during facial affective processing in regions activated during affect evaluation. In schizophrenia, reduced modulation of OFC/VLPFC by context coupled with reduced behavioural efficiency suggests impaired ventral prefrontal control mechanisms that optimize affective appraisal.

  10. The dependence of ipsilesional aiming deficits on task demands, lesioned hemisphere, and apraxia.

    Science.gov (United States)

    Hermsdörfer, J; Blankenfeld, H; Goldenberg, G

    2003-01-01

    Neuroimaging studies as well as neurophysiological and lesion data indicate that the ipsilateral hemisphere plays a role in controlling the active limb. However, the nature and the conditions of this ipsilateral control are not well understood. We measured aiming movements with the ipsilesional limb toward targets with different characteristics which were made by patients with unilateral left brain damage (LBD) or right brain damage (RBD). The movement kinematics were analysed. Performance measures of the pointing movements were impaired in LBD patients, whereas RBD patients performed normally. LBD patients had obvious deficits during all tasks; however, they were exacerbated when high accuracy was required, and when an exocentric target had to be reached without visual feedback. Thus, the motor-dominant hemisphere plays a specific role in the programming and execution of ipsilateral aiming movements, and the importance of ipsilateral control increases with increasing task demands. To assess the relationship between pointing deficits and apraxia in LBD patients, the imitation of meaning gestures was tested. We replicated a recent study, showing that deviations of the final hand position from the demonstration were not correlated with abnormal kinematics of the corresponding arm movement when LBD patients performed this test. However, there were correlations between related kinematic measures during pointing and gesture imitation. These findings suggest a deficit of motor programming and execution after damage to the motor-dominant brain which is unrelated to the spatial errors characteristic of apraxia. This deficit affects different types of goal-directed aiming movements and its severity depends on task demands.

  11. Attentional costs of visually guided walking: effects of age, executive function and stepping-task demands.

    Science.gov (United States)

    Mazaheri, Masood; Roerdink, Melvyn; Bood, Robert Jan; Duysens, Jacques; Beek, Peter J; Peper, C Lieke E

    2014-01-01

    During walking, attention needs to be flexibly allocated to deal with varying environmental constraints. This ability may be affected by aging and lower overall executive function. The present study examined the influence of aging and executive function on the attentional costs of visually guided walking under different task demands. Three groups, young adults (n=15) and elderly adults with higher (n=16) and lower (n=10) executive function, walked on a treadmill in three conditions: uncued walking and walking with regular and irregular patterns of visual stepping targets projected onto the belt. Attentional costs were assessed using a secondary probe reaction time task and corrected by subtracting baseline single-task reaction time, yielding an estimate of the additional attentional costs of each walking condition. We found that uncued walking was more attentionally demanding for elderly than for young participants. In young participants, the attentional costs increased significantly from uncued to regularly cued to irregularly cued walking, whereas for the higher executive function group, attentional costs only increased significantly from regularly cued to irregularly cued walking. For the group with lower executive function, no significant differences were observed. The observed decreased flexibility of elderly, especially those with lower executive function, to allocate additional attentional resources to more challenging walking conditions may be attributed to the already increased attentional costs of uncued walking, presumably required for visuomotor and/or balance control of walking.

  12. Public Relations in Contemporary India: Current Demands and Strategy.

    Science.gov (United States)

    Singh, Raveena

    2000-01-01

    Discusses India's new direction and the persistent and insistent demand for public relations. Explains the strategic plan of the professional body in running the gauntlet in this new milieu and the pertinaciousness and urgency of the challenges ahead for public relations. (SC)

  13. Reduced effects of tendon vibration with increased task demand during active, cyclical ankle movements

    Science.gov (United States)

    Floyd, Lisa M.; Holmes, Taylor C.; Dean, Jesse C.

    2013-01-01

    Tendon vibration can alter proprioceptive feedback, one source of sensory information which humans can use to produce accurate movements. However, the effects of tendon vibration during functional movement vary depending on the task. For example, ankle tendon vibration has considerably smaller effects during walking than standing posture. The purpose of this study was to test whether the effects of ankle tendon vibration are predictably influenced by the mechanical demands of a task, as quantified by peak velocity. Twelve participants performed symmetric, cyclical ankle plantarflexion/dorsiflexion movements while lying prone with their ankle motion unconstrained. The prescribed movement period (1s, 3s) and peak-to-peak amplitude (10°, 15°, 20°) were varied across trials; shorter movement periods or larger amplitudes increased the peak velocity. In some trials, vibration was continuously and simultaneously applied to the right ankle plantarflexor and dorsiflexor tendons, while the left ankle tendons were never vibrated. The vibration frequency (40, 80, 120, 160 Hz) was varied across trials. During trials without vibration, participants accurately matched the movement of their ankles. The application of 80 Hz vibration to the right ankle tendons significantly reduced the amplitude of right ankle movement. However, the effect of vibration was smaller during more mechanically demanding (i.e. higher peak velocity) movements. Higher vibration frequencies had larger effects on movement accuracy, possibly due to parallel increases in vibration amplitude. These results demonstrate that the effects of ankle tendon vibration are dependent on the mechanical demand of the task being performed, but cannot definitively identify the underlying physiological mechanism. PMID:24136344

  14. Working memory capacity and mind-wandering during low-demand cognitive tasks.

    Science.gov (United States)

    Robison, Matthew K; Unsworth, Nash

    2017-07-01

    Individual differences in working memory capacity (WMC) typically predict reduced rates of mind-wandering during laboratory tasks (Randall, Oswald, & Beier, 2014). However, some studies have shown a positive relationship between WMC and mind-wandering during particularly low-demand tasks (Levinson, Smallwood, & Davidson, 2012; Rummel & Boywitt, 2014; Zavagnin, Borella, & De Beni, 2014). More specifically, Baird, Smallwood, and Schooler (2011) found that when individuals with greater WMC do mind-wander, they tend entertain more future-oriented thoughts. This piece of evidence is frequently used to support the context-regulation hypothesis, which states that using spare capacity to think productively (e.g. plan) during relatively simple tasks is indicative of a cognitive system that is functioning in an adaptive manner (Smallwood & Andrews-Hanna, 2013). The present investigation failed to replicate the finding that WMC is positively related to future-oriented off-task thought, which has implications for several theoretical viewpoints. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Scaffolding advice on task selection: A safe path toward self-directed learning in on-demand education.

    NARCIS (Netherlands)

    Kicken, Wendy; Brand-Gruwel, Saskia; Van Merriënboer, Jeroen

    2008-01-01

    Kicken, W., Brand-Gruwel, S., & Van Merrienboer, J. J. G. (2008). Scaffolding advice on task selection: A safe path toward self-directed learning in on-demand education. Journal of Vocational Education and Training, 60, 223-239.

  16. Scaffolding advice on task selection: A safe path toward self-directed learning in on-demand education.

    NARCIS (Netherlands)

    Kicken, Wendy; Brand-Gruwel, Saskia; Van Merriënboer, Jeroen

    2008-01-01

    Kicken, W., Brand-Gruwel, S., & Van Merrienboer, J. J. G. (2008). Scaffolding advice on task selection: A safe path toward self-directed learning in on-demand education. Journal of Vocational Education and Training, 60, 223-239.

  17. Functional brain connectivity and cognition: effects of adult age and task demands.

    Science.gov (United States)

    Chou, Ying-Hui; Chen, Nan-Kuei; Madden, David J

    2013-08-01

    Previous neuroimaging research has documented that patterns of intrinsic (resting state) functional connectivity (FC) among brain regions covary with individual measures of cognitive performance. Here, we examined the relation between intrinsic FC and a reaction time (RT) measure of performance, as a function of age group and task demands. We obtained filtered, event-related functional magnetic resonance imaging data, and RT measures of visual search performance, from 21 younger adults (19-29 years old) and 21 healthy, older adults (60-87 years old). Age-related decline occurred in the connectivity strength in multiple brain regions, consistent with previous findings. Among 8 pairs of regions, across somatomotor, orbitofrontal, and subcortical networks, increasing FC was associated with faster responding (lower RT). Relative to younger adults, older adults exhibited a lower strength of this RT-connectivity relation and greater disruption of this relation by a salient but irrelevant display item (color singleton distractor). Age-related differences in the covariation of intrinsic FC and cognitive performance vary as a function of task demands.

  18. Activation and tremor of the shoulder muscles to the demands of an archery task.

    Science.gov (United States)

    Lin, Jiu-Jenq; Hung, Cheng-Ju; Yang, Ching-Ching; Chen, Hsing-Yu; Chou, Feng-Ching; Lu, Tung-Wu

    2010-02-01

    Physiological tremor and strength during the maintenance of shoulder position occur during a precision aiming task, such as archery. It is unclear how positions for precision demands affect physiological tremor and associated muscular activities. The purpose of this study was to assess the tremor amplitude and muscular activities of the shoulder between the various positions for precision demands. Ten males (age 21.9 +/- 2.0 years) participated in the study. Electromyography (EMG) was quantified on eight humeral/scapular muscles. The tremor was measured by the acceleration component of a motion tracking sensor in the 3-7 Hz and 8-12 Hz frequency bands. Participants simulated six preparatory archery shooting positions (3 arm angles x 2 arm draw positions) and performed isometric contractions. The relative root mean square (RMS) amplitudes of the shoulder muscles were significantly greater for the full drawing position compared with the partial position (humeral muscles: P = 0.011; scapular muscles: P = 0.026). In the full drawing position, increased humeral/scapular muscle EMG amplitude was moderately associated with an increased power spectrum of 8-12/3-7 Hz tremor in humerus/scapula motion (R = 0.43-0.57). To minimize fluctuations in high strength muscle performance, 90 degrees of elevation in the full drawing position may be a suitable position for demands in archery. In addition, scapular muscle amplitude is important for stability to reduce humerus tremor during archery performance.

  19. Extending hierarchical task analysis to identify cognitive demands and information design requirements.

    Science.gov (United States)

    Phipps, Denham L; Meakin, George H; Beatty, Paul C W

    2011-07-01

    While hierarchical task analysis (HTA) is well established as a general task analysis method, there appears a need to make more explicit both the cognitive elements of a task and design requirements that arise from an analysis. One way of achieving this is to make use of extensions to the standard HTA. The aim of the current study is to evaluate the use of two such extensions--the sub-goal template (SGT) and the skills-rules-knowledge (SRK) framework--to analyse the cognitive activity that takes place during the planning and delivery of anaesthesia. In quantitative terms, the two methods were found to have relatively poor inter-rater reliability; however, qualitative evidence suggests that the two methods were nevertheless of value in generating insights about anaesthetists' information handling and cognitive performance. Implications for the use of an extended HTA to analyse work systems are discussed.

  20. The effects of precision demands during a low intensity pinching task on muscle activation and load sharing of the fingers

    NARCIS (Netherlands)

    Visser, B.; Looze, M.P. de; Veeger, D.; Douwes, M.; Groenesteijn, L.; Korte, E. de; Dieën, J.H. van

    2003-01-01

    High precision demands in manual tasks can be expected to cause more selective use of a part of the muscular synergy involved. To test this expectation, load sharing of the index finger and middle finger was investigated during a pinching task. Myoelectric activation of lower arm and neck-shoulder m

  1. An Examination of the Role of Technological Tools in Relation to the Cognitive Demand of Mathematical Tasks in Secondary Classrooms

    Science.gov (United States)

    Sherman, Milan

    2011-01-01

    This study investigates the role of digital cognitive technologies in supporting students' mathematical thinking while engaging with instructional tasks. Specifically, the study sought to better understand how the use of technology is related to the cognitive demand of tasks. Data were collected in four secondary mathematics classrooms via…

  2. The effects of precision demands during a low intensity pinching task on muscle activation and load sharing of the fingers

    NARCIS (Netherlands)

    Visser, B.; Looze, M.P. de; Veeger, D.; Douwes, M.; Groenesteijn, L.; Korte, E. de; Dieën, J.H. van

    2003-01-01

    High precision demands in manual tasks can be expected to cause more selective use of a part of the muscular synergy involved. To test this expectation, load sharing of the index finger and middle finger was investigated during a pinching task. Myoelectric activation of lower arm and neck-shoulder

  3. The effects of precision demands during a low intensity pinching task on muscle activation and load sharing of the fingers

    NARCIS (Netherlands)

    Visser, B.; Looze, M.P. de; Veeger, D.; Douwes, M.; Groenesteijn, L.; Korte, E. de; Dieën, J.H. van

    2003-01-01

    High precision demands in manual tasks can be expected to cause more selective use of a part of the muscular synergy involved. To test this expectation, load sharing of the index finger and middle finger was investigated during a pinching task. Myoelectric activation of lower arm and neck-shoulder m

  4. Current supply and demand of veterinarians in Japan

    Directory of Open Access Journals (Sweden)

    Katsuaki Sugiura

    2008-06-01

    Full Text Available Since 1966, approximately 1 000 veterinarians graduate each year from 16 veterinary schools in Japan. According to reports submitted by veterinarians to the Ministry of Agriculture, Forestry and Fisheries in January 2007, there were over 35 818 veterinarians in Japan at the end of 2006. Of this total, 13 202 (36.8% were engaged in companion animal practice, 9 112 (25.4% were civil servants and 4 180 (11.7% were engaged in food animal practice. The total number of veterinarians has increased gradually over the past 40 years. Recently, the number of veterinarians engaged in companion animal practice has increased while the number of veterinarians engaged in food animal practice is declining. These trends reflect the change in demand for veterinarians in food and companion animal practice, resulting mainly from changes in the number of food animals and companion animals in recent years. The number of veterinarians in the public sector has decreased gradually due to the administrative reforms of recent years.

  5. Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing.

    Science.gov (United States)

    Vannini, Patrizia; Lehmann, Christoph; Dierks, Thomas; Jann, Kay; Viitanen, Matti; Wahlund, Lars-Olof; Almkvist, Ove

    2008-09-01

    Alzheimer's disease (AD) is characterized by disturbances of visuospatial cognition. Given that these impairments are closely related to metabolic and neuropathological changes, our study aimed to investigate the functional competency of brain regions in the visuospatial networks responsible for early clinical symptoms in AD using event-related functional magnetic resonance imaging (fMRI). Participants (13AD patients with mild symptoms and 13 age- and education-matched controls) performed an angle discrimination task with varying task demand. Using a novel approach that modeled the dependency of the blood oxygenation level-dependent (BOLD) signal on the subject's reaction time allowed us to investigate task demand-dependent signal changes between the groups. Both groups demonstrated overlapping neural networks engaged in angle discrimination, including the parieto-occipital and frontal regions. In several network regions, AD patients showed a significantly weaker and sometimes no BOLD signal due to increased task demand compared with controls, demonstrating failure to modulate the neural response to increased task demand. A general task demand-independent increase of activation in AD patients compared with controls was found in right middle temporal gyrus. This latter finding may indicate an attempt to compensate for dysfunctional areas in the dorsal visual pathway. These results confirm deficits in visuospatial abilities, which occur early in AD, and offer new insights into the neural mechanisms underlying this impairment.

  6. Isolating Discriminant Neural Activity in the Presence of Eye Movements and Concurrent Task Demands

    Directory of Open Access Journals (Sweden)

    Jon Touryan

    2017-07-01

    Full Text Available A growing number of studies use the combination of eye-tracking and electroencephalographic (EEG measures to explore the neural processes that underlie visual perception. In these studies, fixation-related potentials (FRPs are commonly used to quantify early and late stages of visual processing that follow the onset of each fixation. However, FRPs reflect a mixture of bottom-up (sensory-driven and top-down (goal-directed processes, in addition to eye movement artifacts and unrelated neural activity. At present there is little consensus on how to separate this evoked response into its constituent elements. In this study we sought to isolate the neural sources of target detection in the presence of eye movements and over a range of concurrent task demands. Here, participants were asked to identify visual targets (Ts amongst a grid of distractor stimuli (Ls, while simultaneously performing an auditory N-back task. To identify the discriminant activity, we used independent components analysis (ICA for the separation of EEG into neural and non-neural sources. We then further separated the neural sources, using a modified measure-projection approach, into six regions of interest (ROIs: occipital, fusiform, temporal, parietal, cingulate, and frontal cortices. Using activity from these ROIs, we identified target from non-target fixations in all participants at a level similar to other state-of-the-art classification techniques. Importantly, we isolated the time course and spectral features of this discriminant activity in each ROI. In addition, we were able to quantify the effect of cognitive load on both fixation-locked potential and classification performance across regions. Together, our results show the utility of a measure-projection approach for separating task-relevant neural activity into meaningful ROIs within more complex contexts that include eye movements.

  7. Cross-linguistic similarity and task demands in Japanese-English bilingual processing.

    Science.gov (United States)

    Allen, David B; Conklin, Kathy

    2013-01-01

    Even in languages that do not share script, bilinguals process cognates faster than matched noncognates in a range of tasks. The current research more fully explores what underpins the cognate 'advantage' in different script bilinguals (Japanese-English). To do this, instead of the more traditional binary cognate/noncognate distinction, the current study uses continuous measures of phonological and semantic overlap, L2 (second language) proficiency and lexical variables (e.g., frequency). An L2 picture naming (Experiment 1) revealed a significant interaction between phonological and semantic similarity and demonstrates that degree of overlap modulates naming times. In lexical decision (Experiment 2), increased phonological similarity (e.g., bus/basu/vs. radio/rajio/) lead to faster response times. Interestingly, increased semantic similarity slowed response times in lexical decision. The studies also indicate how L2 proficiency and lexical variables modulate L2 word processing. These findings are explained in terms of current models of bilingual lexical processing.

  8. How low can you go? Changing the resolution of novel complex objects in visual working memory according to task demands

    Directory of Open Access Journals (Sweden)

    Ayala S Allon

    2014-03-01

    Full Text Available In three experiments we manipulated the resolution of novel complex objects in visual working memory (WM by changing task demands. Previous studies that investigated the trade-off between quantity and resolution in visual WM yielded mixed results for simple familiar stimuli. We used the contralateral delay activity (the CDA as an electrophysiological marker to directly track the deployment of visual WM resources while participants preformed a change-detection task. Across 3 experiments we presented the same novel items but changed the task demands. In Experiment 1 we induced a medium resolution task by using change trials in which a random polygon changed to a different type of polygon and replicated previous findings showing that novel complex objects are represented with higher resolution relative to simple familiar objects. In Experiment 2 we induced a low resolution task that required distinguishing between polygons and other types of stimulus categories, but we failed in finding a corresponding decrease in the resolution of the represented item. Finally, in Experiment 3 we induced a high resolution task that required discriminating between highly similar polygons with somewhat different contours. This time, we observed an increase in the item’s resolution. Our findings indicate that the resolution for novel complex objects can be increased but not decreased according to task demands, suggesting that minimal resolution is required in order to maintain these items in visual WM. These findings support studies claiming that capacity and resolution in visual WM reflect different mechanisms.

  9. How low can you go? Changing the resolution of novel complex objects in visual working memory according to task demands.

    Science.gov (United States)

    Allon, Ayala S; Balaban, Halely; Luria, Roy

    2014-01-01

    In three experiments we manipulated the resolution of novel complex objects in visual working memory (WM) by changing task demands. Previous studies that investigated the trade-off between quantity and resolution in visual WM yielded mixed results for simple familiar stimuli. We used the contralateral delay activity as an electrophysiological marker to directly track the deployment of visual WM resources while participants preformed a change-detection task. Across three experiments we presented the same novel complex items but changed the task demands. In Experiment 1 we induced a medium resolution task by using change trials in which a random polygon changed to a different type of polygon and replicated previous findings showing that novel complex objects are represented with higher resolution relative to simple familiar objects. In Experiment 2 we induced a low resolution task that required distinguishing between polygons and other types of stimulus categories, but we failed in finding a corresponding decrease in the resolution of the represented item. Finally, in Experiment 3 we induced a high resolution task that required discriminating between highly similar polygons with somewhat different contours. This time, we observed an increase in the item's resolution. Our findings indicate that the resolution for novel complex objects can be increased but not decreased according to task demands, suggesting that minimal resolution is required in order to maintain these items in visual WM. These findings support studies claiming that capacity and resolution in visual WM reflect different mechanisms.

  10. Relative effects of demand and control on task-related cardiovascular reactivity, task perceptions, performance accuracy, and mood.

    Science.gov (United States)

    Flynn, Niamh; James, Jack E

    2009-05-01

    The hypothesis that work control has beneficial effects on well-being is the basis of the widely applied, yet inconsistently supported, Job Demand Control (JDC) Model [Karasek, R.A., 1979. Job demands, job decision latitude and mental strain: Implications for job redesign. Adm. Sci. Q. 24, 285-308.; Karasek, R., Theorell, T., 1990. Healthy Work: Stress, Productivity, and the Reconstruction of Working Life. Basic Books, Oxford]. The model was tested in an experiment (N=60) using a cognitive stressor paradigm that sought to prevent confounding between demand and control. High-demand was found to be associated with deleterious effects on physiological, subjective, and performance outcomes. In contrast, few main effects were found for control. Evidence for the buffer interpretation of the JDC Model was limited to a significant demand-control interaction for performance accuracy, whereas substantial support was found for the strain interpretation of the model [van der Doef, M., Maes, S., 1998. The job demand-control(-support) model and physical health outcomes: A review of the strain and buffer hypotheses. Psychol. Health 13, 909-936., van der Doef, M., Maes, S., 1999. The Job Demand-Control(-Support) model and psychological well-being: A review of 20 years of empirical research. Work Stress 13, 87-114]. Manipulation checks revealed that objective control altered perceptions of control but not perceptions of demand. It is suggested that beneficial effects of work-related control are unlikely to occur in the absence of reductions in perceived demand. Thus, contrary to the propositions of Karasek and colleagues, demand and control do not appear to be independent factors.

  11. AAPM/SNMMI Joint Task Force: report on the current state of nuclear medicine physics training.

    Science.gov (United States)

    Harkness, Beth A; Allison, Jerry D; Clements, Jessica B; Coffey, Charles W; Fahey, Frederic H; Gress, Dustin A; Kinahan, Paul E; Nickoloff, Edward L; Mawlawi, Osama R; MacDougall, Robert D; Pizzutiello, Robert J

    2015-09-08

    The American Association of Physicists in Medicine (AAPM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) recognized the need for a review of the current state of nuclear  medicine physics training and the need to explore pathways for improving nuclear medicine physics training opportunities. For these reasons, the two organizations formed a joint AAPM/SNMMI Ad Hoc Task Force on Nuclear Medicine Physics  Training. The mission of this task force was to assemble a representative group of stakeholders to:• Estimate the demand for board-certified nuclear medicine physicists in the next 5-10 years,• Identify the critical issues related to supplying an adequate number of physicists who have received the appropriate level of training in nuclear medicine physics, and• Identify approaches that may be considered to facilitate the training of nuclear medicine physicists.As a result, a task force was appointed and chaired by an active member of both organizations that included representation from the AAPM, SNMMI, the American Board of Radiology (ABR), the American Board of Science in Nuclear Medicine (ABSNM), and the Commission for the Accreditation of Medical Physics Educational Programs (CAMPEP). The Task Force first met at the AAPM Annual Meeting in Charlotte in July 2012 and has met regularly face-to-face, online, and by conference calls. This manuscript reports the findings of the Task Force, as well as recommendations to achieve the stated mission.

  12. Effects of physical and mental task demands on cervical and upper limb muscle activity and physiological responses during computer tasks and recovery periods.

    Science.gov (United States)

    Wang, Yuling; Szeto, Grace P Y; Chan, Chetwyn C H

    2011-11-01

    The present study examined the effects of physical and mental workload during computer tasks on muscle activity and physiological measures. Activity in cervical postural muscles and distal forearm muscles, heart rate and blood pressure were compared among three tasks and rest periods of 15 min each in an experimental study design. Fourteen healthy pain-free adults participated (7 males, mean age = 23.2 ± 3.0 years) and the tasks were: (1) copy-typing ("typing"), (2) typing at progressively faster speed ("pacing"), (3) mental arithmetic plus fast typing ("subtraction"). Typing task was performed first, followed by the other two tasks in a random order. Median muscle activity (50th percentile) was examined in 5-min intervals during each task and each rest period, and statistically significant differences in the "time" factor (within task) and time × task factors was found in bilateral cervical erector spinae and upper trapezius muscles. In contrast, distal forearm muscle activity did not show any significant differences among three tasks. All muscles showed reduced activity to about the baseline level within first 5 min of the rest periods. Heart rate and blood pressure showed significant differences during tasks compared to baseline, and diastolic pressure was significantly higher in the subtraction than pacing task. The results suggest that cervical postural muscles had higher reactivity than forearm muscles to high mental workload tasks, and cervical muscles were also more reactive to tasks with high physical demand compared to high mental workload. Heart rate and blood pressure seemed to respond similarly to high physical and mental workloads.

  13. The clinical endocrinology workforce: current status and future projections of supply and demand.

    Science.gov (United States)

    Vigersky, Robert A; Fish, Lisa; Hogan, Paul; Stewart, Andrew; Kutler, Stephanie; Ladenson, Paul W; McDermott, Michael; Hupart, Kenneth H

    2014-09-01

    Many changes in health care delivery, health legislation, and the physician workforce that affect the supply and demand for endocrinology services have occurred since the first published workforce study of adult endocrinologists in 2003. The objective of the study was to assess the current adult endocrinology workforce data and provide the first analysis of the pediatric endocrinology workforce and to project the supply of and demand for endocrinologists through 2025. A workforce model was developed from an analysis of proprietary and publicly available databases, consultation with a technical expert panel, and the results of an online survey of board-certified endocrinologists. The Endocrine Society commissioned The Lewin Group to estimate current supply and to project gaps between supply and demand for endocrinologists. A technical expert panel of senior endocrinologists provided context, clinical information, and direction. The following were measured: 1) the current adult and pediatric endocrinology workforce and the supply of and demand for endocrinologists through 2025 and 2) the number of additional entrants into the endocrinology work pool that would be required to close the gap between supply and demand. Currently there is a shortage of approximately 1500 adult and 100 pediatric full-time equivalent endocrinologists. The gap for adult endocrinologists will expand to 2700 without an increase in the number of fellows trained. An increase in the prevalence of diabetes mellitus further expands the demand for adult endocrinologists. The gap can be closed in 5 and 10 years by increasing the number of fellowship positions by 14.4% and 5.5% per year, respectively. The gap between supply and demand for pediatric endocrinologists will close by 2016, and thereafter an excess supply over demand will develop at the current rate of new entrants into the work force. There are insufficient adult endocrinologists to satisfy current and future demand. A number of proactive

  14. Adaptations of writing posture in response to task demands for left- and right-handers.

    Science.gov (United States)

    Szeligo, Frank; Brazier, Bette; Houston, Joël

    2003-07-01

    Handedness and writing posture are visible manifestations of differences between left- and right-handers. Although an inverted posture is witnessed in both groups, there is a much higher proportion of left-handers who invert. This study is framed within the adaptation hypothesis of writing posture, which states that invertedness in left-handers develops in response to the demands of cursive writing. Participants (N = 57) comprising left-handed inverters, left-handed standard writers, and right-handed standard writers engaged in tasks that required them to form letters and pen strokes at extreme angles. In addition participants were questioned about attempts to change writing posture. We hypothesised that letter angle controls posture in both left- and right-handers and that inverted posture would be a target of intervention. The results of the study showed some support for these hypotheses in that left- and right-handers adapted their posture in response to the constraints placed upon them and inverters reported more intervention.

  15. Cardiac adaptivity to attention-demanding tasks in children with a pervasive developmental disorder not otherwise specified (PDD-NOS)

    NARCIS (Netherlands)

    Althaus, M; Aarnoudse, CC; Minderaa, RB; Mulder, Gysbertus; Mulder, Lambertus

    1999-01-01

    Background: Decreases in heart rate variability (HRV) have been repeatedly demonstrated to be an index of effort allocation to attention-demanding tasks. Children with autistic-type problems in social interaction and in adapting to unfamiliar situations (DSM-IV: PDD-NOS) have been shown to have

  16. Prefrontal cortex activation upon a demanding virtual hand-controlled task: a new frontier for neuroergonomics

    Directory of Open Access Journals (Sweden)

    Marika eCarrieri

    2016-02-01

    Full Text Available Functional near-infrared spectroscopy (fNIRS is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC in subjects while performing a demanding VR hand-controlled task (HCT. Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3D hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB over a virtual route (VROU reproducing a 42-m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2±37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found

  17. Prefrontal Cortex Activation Upon a Demanding Virtual Hand-Controlled Task: A New Frontier for Neuroergonomics.

    Science.gov (United States)

    Carrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found

  18. Cross-linguistic similarity and task demands in Japanese-English bilingual processing.

    Directory of Open Access Journals (Sweden)

    David B Allen

    Full Text Available Even in languages that do not share script, bilinguals process cognates faster than matched noncognates in a range of tasks. The current research more fully explores what underpins the cognate 'advantage' in different script bilinguals (Japanese-English. To do this, instead of the more traditional binary cognate/noncognate distinction, the current study uses continuous measures of phonological and semantic overlap, L2 (second language proficiency and lexical variables (e.g., frequency. An L2 picture naming (Experiment 1 revealed a significant interaction between phonological and semantic similarity and demonstrates that degree of overlap modulates naming times. In lexical decision (Experiment 2, increased phonological similarity (e.g., bus/basu/vs. radio/rajio/ lead to faster response times. Interestingly, increased semantic similarity slowed response times in lexical decision. The studies also indicate how L2 proficiency and lexical variables modulate L2 word processing. These findings are explained in terms of current models of bilingual lexical processing.

  19. Cross-Linguistic Similarity and Task Demands in Japanese-English Bilingual Processing

    Science.gov (United States)

    Allen, David B.; Conklin, Kathy

    2013-01-01

    Even in languages that do not share script, bilinguals process cognates faster than matched noncognates in a range of tasks. The current research more fully explores what underpins the cognate ‘advantage’ in different script bilinguals (Japanese-English). To do this, instead of the more traditional binary cognate/noncognate distinction, the current study uses continuous measures of phonological and semantic overlap, L2 (second language) proficiency and lexical variables (e.g., frequency). An L2 picture naming (Experiment 1) revealed a significant interaction between phonological and semantic similarity and demonstrates that degree of overlap modulates naming times. In lexical decision (Experiment 2), increased phonological similarity (e.g., bus/basu/vs. radio/rajio/) lead to faster response times. Interestingly, increased semantic similarity slowed response times in lexical decision. The studies also indicate how L2 proficiency and lexical variables modulate L2 word processing. These findings are explained in terms of current models of bilingual lexical processing. PMID:24015266

  20. Preschool children fail primate prosocial game because of attentional task demands.

    Directory of Open Access Journals (Sweden)

    Judith Maria Burkart

    Full Text Available Various nonhuman primate species have been tested with prosocial games (i.e. derivates from dictator games in order to better understand the evolutionary origin of proactive prosociality in humans. Results of these efforts are mixed, and it is difficult to disentangle true species differences from methodological artifacts. We tested 2- to 5-year-old children with a costly and a cost-free version of a prosocial game that differ with regard to the payoff distribution and are widely used with nonhuman primates. Simultaneously, we assessed the subjects' level of Theory of Mind understanding. Prosocial behavior was demonstrated with the prosocial game, and did not increase with more advanced Theory of Mind understanding. However, prosocial behavior could only be detected with the costly version of the game, whereas the children failed the cost-free version that is most commonly used with nonhuman primates. A detailed comparison of the children's behavior in the two versions of the game indicates that the failure was due to higher attentional demands of the cost-free version, rather than to a lack of prosociality per se. Our results thus show (i that subtle differences in prosociality tasks can substantially bias the outcome and thus prevent meaningful species comparisons, and (ii that like in nonhuman primates, prosocial behavior in human children does not require advanced Theory of Mind understanding in the present context. However, both developmental and comparative psychology accumulate increasing evidence for the multidimensionality of prosocial behaviors, suggesting that different forms of prosociality are also regulated differentially. For future efforts to understand the evolutionary origin of prosociality it is thus crucial to take this heterogeneity into account.

  1. Preschool Children Fail Primate Prosocial Game Because of Attentional Task Demands

    Science.gov (United States)

    Burkart, Judith Maria; Rueth, Katja

    2013-01-01

    Various nonhuman primate species have been tested with prosocial games (i.e. derivates from dictator games) in order to better understand the evolutionary origin of proactive prosociality in humans. Results of these efforts are mixed, and it is difficult to disentangle true species differences from methodological artifacts. We tested 2- to 5-year-old children with a costly and a cost-free version of a prosocial game that differ with regard to the payoff distribution and are widely used with nonhuman primates. Simultaneously, we assessed the subjects’ level of Theory of Mind understanding. Prosocial behavior was demonstrated with the prosocial game, and did not increase with more advanced Theory of Mind understanding. However, prosocial behavior could only be detected with the costly version of the game, whereas the children failed the cost-free version that is most commonly used with nonhuman primates. A detailed comparison of the children’s behavior in the two versions of the game indicates that the failure was due to higher attentional demands of the cost-free version, rather than to a lack of prosociality per se. Our results thus show (i) that subtle differences in prosociality tasks can substantially bias the outcome and thus prevent meaningful species comparisons, and (ii) that like in nonhuman primates, prosocial behavior in human children does not require advanced Theory of Mind understanding in the present context. However, both developmental and comparative psychology accumulate increasing evidence for the multidimensionality of prosocial behaviors, suggesting that different forms of prosociality are also regulated differentially. For future efforts to understand the evolutionary origin of prosociality it is thus crucial to take this heterogeneity into account. PMID:23844201

  2. Task-Specific Facilitation of Cognition by Anodal Transcranial Direct Current Stimulation of the Prefrontal Cortex.

    Science.gov (United States)

    Pope, Paul A; Brenton, Jonathan W; Miall, R Chris

    2015-11-01

    We previously speculated that depression of cerebellar excitability using cathodal transcranial direct current stimulation (tDCS) might release extra cognitive resources via the disinhibition of activity in prefrontal cortex. The objective of the present study was to investigate whether anodal tDCS over the prefrontal cortex could similarly improve performance when cognitive demands are high. Sixty-three right-handed participants in 3 separate groups performed the Paced Auditory Serial Addition Task (PASAT) and the more difficult Paced Auditory Serial Subtraction Task (PASST), before and after 20 min of anodal, cathodal, or sham stimulation over the left dorsolateral prefrontal cortex (DLPFC). Performance was assessed in terms of the accuracy, latency, and variability of correct verbal responses. All behavioral measures significantly improved for the PASST after anodal DLPFC stimulation, but not the PASAT. There were smaller practice effects after cathodal and sham stimulation. Subjective ratings of attention and mental fatigue were unchanged by tDCS over time. We conclude that anodal stimulation over the left DLPFC can selectively improve performance on a difficult cognitive task involving arithmetic processing, verbal working memory, and attention. This result might be achieved by focally improving executive functions and/or cognitive capacity when tasks are difficult, rather than by improving levels of arousal/alertness.

  3. Timing Is Affected by Demands in Memory Search but Not by Task Switching

    Science.gov (United States)

    Fortin, Claudette; Schweickert, Richard; Gaudreault, Remi; Viau-Quesnel, Charles

    2010-01-01

    Recent studies suggest that timing and tasks involving executive control processes might require the same attentional resources. This should lead to interference when timing and executive tasks are executed concurrently. This study examined the interference between timing and task switching, an executive function. In 4 experiments, memory search…

  4. Amygdala responses to unpleasant pictures are influenced by task demands and positive affect trait

    Directory of Open Access Journals (Sweden)

    Tiago Arruda Sanchez

    2015-03-01

    Full Text Available The role of attention in emotional processing is still the subject of debate. Recent studies have found that high positive affect in approach motivation narrows attention. Furthermore, the positive affect trait has been suggested as an important component for determining human variability in threat reactivity. We employed fMRI to investigate whether different states of attention control would modulate amygdala responses to highly unpleasant pictures relative to neutral and whether this modulation would be influenced by the positive affect trait. Participants (n=22, 12 male were scanned while viewing neutral (people or unpleasant pictures (mutilated bodies flanked by two peripheral bars. They were instructed to (a judge the picture content as unpleasant or neutral or (b to judge the difference in orientation between the bars in an easy condition (0º or 90º orientation difference or (c in a hard condition (0º or 6º orientation difference. Whole brain analysis revealed a task main effect of brain areas related to the experimental manipulation of attentional control, including the amygdala, dorsolateral prefrontal cortex and posterior parietal cortex. ROI analysis showed an inverse correlation (r = -0.51, p < 0.01 between left amygdala activation and positive affect level when participants viewed unpleasant stimuli and judged bar orientation in the easy condition. This result suggests that subjects with high positive affect exhibit lower amygdala reactivity to distracting unpleasant pictures. In conclusion, the current study suggests that positive affect modulates attention effect on unpleasant pictures, therefore attenuating emotional responses.

  5. Individual differences in oscillatory brain activity in response to varying attentional demands during a word recall and oculomotor dual task

    Directory of Open Access Journals (Sweden)

    Gusang eKwon

    2015-06-01

    Full Text Available Every day, we face situations that involve multi-tasking. How our brain utilizes cortical resources during multi-tasking is one of many interesting research topics. In this study, we tested whether a dual-task can be differentiated in the neural and behavioral responses of healthy subjects with varying degree of working memory capacity (WMC. We combined word recall and oculomotor tasks because they incorporate common neural networks including the fronto-parietal (FP network. Three different types of oculomotor tasks (eye fixation; Fix-EM, predictive & random smooth pursuit eye movement; P-SPEM & R-SPEM were combined with two memory load levels (low-load: 5 words, high-load: 10 words for a word recall task. Each of those dual-task combinations was supposed to create varying cognitive loads on the FP network. We hypothesize that each dual-task requires different cognitive strategies for allocating the brain’s limited cortical resources and affects brain oscillation of the FP network. In addition, we hypothesized that groups with different WMC will show differential neural and behavioral responses. We measured oscillatory brain activity with simultaneous MEG and EEG recordings and behavioral performance by word recall. Prominent frontal midline (FM theta (4-6 Hz synchronization emerged in the EEG of the high-WMC group experiencing R-SPEM with high-load conditions during the early phase of the word maintenance period. Conversely, significant parietal upper alpha (10-12 Hz desynchronization was observed in the EEG and MEG of the low-WMC group experiencing P-SPEM under high-load conditions during the same period. Different brain oscillatory patterns seem to depend on each individual’s WMC and varying attentional demands from different dual-task combinations. These findings suggest that specific brain oscillations may reflect different strategies for allocating cortical resources during combined word recall and oculomotor dual-tasks.

  6. Assessing the Cognitive Demands of a Century of Reading Curricula: An Analysis of Reading Text and Comprehension Tasks from 1910 to 2000

    Science.gov (United States)

    Stevens, Robert J.; Lu, Xiaofei; Baker, David P.; Ray, Melissa N.; Eckert, Sarah A.; Gamson, David A.

    2015-01-01

    This research investigated the cognitive demands of reading curricula from 1910 to 2000. We considered both the nature of the text used and the comprehension tasks asked of students in determining the cognitive demands of the curricula. Contrary to the common assumption of a trend of simplification of the texts and comprehension tasks in third-…

  7. Age-related changes in postural control to the demands of a precision task.

    Science.gov (United States)

    Yeh, Ting-Ting; Cinelli, Michael E; Lyons, James L; Lee, Timothy D

    2015-12-01

    Optimal sensorimotor integration is needed to maintain the precision of a visuomotor postural task. Furthermore, cognitive resources have been suggested to be involved in maintaining balance, especially in older adults. This study investigated how older and younger adults differed in employing sensorimotor strategies in a dual-task situation. Older (age 65-84 years) and younger adults (age 19-30 years) performed a visually-based, postural tracking task in different body orientations (from 0° to 45°), which necessitated slightly different task goals. On some trials, participants performed a concurrent silent arithmetic task with the visuomotor tracking task. The results demonstrated that sensorimotor control declined with age. Older adults showed greater medial-lateral center of pressure variability compared to younger adults in the precision task. Younger adults displayed a trend to decrease anterior-posterior variability, but older adults exhibited an opposite trend when the body orientation changed from 0° to 45°. The addition of a dual-task situation decreased overall postural variability in both age groups. Age-related changes in postural control may degrade the flexible coordination of the sensory feedback and motor execution. This study suggested that medial-lateral stability may be more sensitive to this age-related decline and may be closely associated with postural instability and falls.

  8. Adaptive strategy changes as a function of task demands : a study of car drivers

    NARCIS (Netherlands)

    Cnossen, F; Meijman, T; Rothengatter, T; Rothengatter, J.A.

    2004-01-01

    When drivers perform additional tasks while driving, research shows conflicting results: primary driving performance may deteriorate but adaptive changes such as reducing driving speed have also been noted. We hypothesized that the nature of the secondary task may be important: drivers may give more

  9. Attentional Capture by Salient Distractors during Visual Search Is Determined by Temporal Task Demands

    DEFF Research Database (Denmark)

    Kiss, Monika; Grubert, Anna; Petersen, Anders

    2012-01-01

    The question whether attentional capture by salient but taskirrelevant visual stimuli is triggered in a bottom–up fashion or depends on top–down task settings is still unresolved. Strong support for bottom–up capture was obtained in the additional singleton task, in which search arrays were visib...

  10. Current economic downturn and supply chain : The significance of demand and inventory smoothing

    NARCIS (Netherlands)

    Cannella, S.; Ashayeri, J.; Miranda, P.A.; Bruccoleri, M.

    2014-01-01

    The aim of this article is to analyse and quantify the effects of demand and inventory smoothing into supply-chain performance, facing the extreme volatility and impetuous alteration of the market produced by the current economic recession. To do so, we model a traditional serial three-stage supply

  11. Current economic downturn and supply chain : The significance of demand and inventory smoothing

    NARCIS (Netherlands)

    Cannella, S.; Ashayeri, J.; Miranda, P.A.; Bruccoleri, M.

    2014-01-01

    The aim of this article is to analyse and quantify the effects of demand and inventory smoothing into supply-chain performance, facing the extreme volatility and impetuous alteration of the market produced by the current economic recession. To do so, we model a traditional serial three-stage supply

  12. Neural correlates of metacognition: A critical perspective on current tasks.

    Science.gov (United States)

    Insabato, Andrea; Pannunzi, Mario; Deco, Gustavo

    2016-12-01

    Humans have a remarkable ability to reflect upon their behavior and mental processes, a capacity known as metacognition. Recent neurophysiological experiments have attempted to elucidate the neural correlates of metacognition in other species. Despite this increased attention, there is still no operational definition of metacognition and the ability of behavioral tasks to reflect metacognition is the subject of debate. The most widely used task for studying metacognition in animals, the uncertain-option task, has been criticized because it can be solved by simple associative mechanisms. Here we propose a broad perspective that generalizes those critiques to another task, post-decision wagering. Moreover, we extend this critical view to account for recent neurophysiological evidence. We argue these tasks are simple enough that any animal could solve them using very simple mechanisms such as sensory-motor associations. In this case, it is impossible to know whether all animals are metacognitive, or if the tasks are simply not appropriate. Therefore, we suggest using better defined concepts until a suitable task for metacognition is available. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Synchronous EMG activity in the Piper frequency band reveals the corticospinal demand of walking tasks

    OpenAIRE

    Clark, David J.; Kautz, Steven A.; Bauer, Andrew R.; Chen, Yen-Ting; Evangelos A Christou

    2013-01-01

    Evidence indicates that the frequency-domain characteristics of surface electromyogram (EMG) signals are modulated according to the contributing sources of neural drive. Modulation of inter-muscular EMG synchrony within the Piper frequency band (30–60Hz) during movement tasks has been linked to drive from the corticospinal tract. However, it is not known whether EMG synchrony is sufficiently sensitive to detect task-dependent differences in the corticospinal contribution to leg muscle activat...

  14. Supply and demand analysis of the current and future US neurology workforce.

    Science.gov (United States)

    Dall, Timothy M; Storm, Michael V; Chakrabarti, Ritashree; Drogan, Oksana; Keran, Christopher M; Donofrio, Peter D; Henderson, Victor W; Kaminski, Henry J; Stevens, James C; Vidic, Thomas R

    2013-07-30

    This study estimates current and projects future neurologist supply and demand under alternative scenarios nationally and by state from 2012 through 2025. A microsimulation supply model simulates likely career choices of individual neurologists, taking into account the number of new neurologists trained each year and changing demographics of the neurology workforce. A microsimulation demand model simulates utilization of neurology services for each individual in a representative sample of the population in each state and for the United States as a whole. Demand projections reflect increased prevalence of neurologic conditions associated with population growth and aging, and expanded coverage under health care reform. The estimated active supply of 16,366 neurologists in 2012 is projected to increase to 18,060 by 2025. Long wait times for patients to see a neurologist, difficulty hiring new neurologists, and large numbers of neurologists who do not accept new Medicaid patients are consistent with a current national shortfall of neurologists. Demand for neurologists is projected to increase from ∼18,180 in 2012 (11% shortfall) to 21,440 by 2025 (19% shortfall). This includes an increased demand of 520 full-time equivalent neurologists starting in 2014 from expanded medical insurance coverage associated with the Patient Protection and Affordable Care Act. In the absence of efforts to increase the number of neurology professionals and retain the existing workforce, current national and geographic shortfalls of neurologists are likely to worsen, exacerbating long wait times and reducing access to care for Medicaid beneficiaries. Current geographic differences in adequacy of supply likely will persist into the future.

  15. Household task demands for quiet and focused behavior facilitate performance by ADHD youth

    Directory of Open Access Journals (Sweden)

    Camila Guimarães Mendes

    2016-07-01

    Full Text Available ABSTRACT This study evaluated the associations among symptoms of attention-deficit/hyperactivity disorder (ADHD and of oppositional defiant disorder (ODD in children and adolescents’ performance in household tasks and assistance provided by caregivers. Parents of children from 6 to 14 years old with ADHD (n = 67 were interviewed with the Children Helping Out: Responsibilities, Expectations, and Supports (CHORES instrument. Significant correlations were found between symptoms of ODD and assistance in self-care tasks (r = −0.31; p = 0.01; symptoms of hyperactivity correlated with assistance in self-care (r = −0.30, p = 0.01; and family-care (r = −0.25, p = 0.04 tasks. Age was directly associated with the number of tasks performed by children and inversely related to the assistance provided by caregivers. A greater number of ODD symptoms resulted in more household assistance from caregivers. Characteristics of ODD symptoms, such as disobedience and hostility in the face of authority, may limit these children in accessing household tasks by their own initiative, requiring assistance from caregivers.

  16. Eldercare Demands, Mental Health, and Work Performance : The Moderating Role of Satisfaction With Eldercare Tasks

    NARCIS (Netherlands)

    Zacher, Hannes; Jimmieson, Nerina L.; Winter, Gabriele

    2012-01-01

    Due to demographic changes, a growing number of employees provide in-home care to an elderly family member. Previous research suggested a negative relationship between employees' eldercare demands and their work performance. However, the empirical nature of this relationship and its boundary conditi

  17. Learning to Predict Demand in a Transport-Resource Sharing Task

    Science.gov (United States)

    2015-09-01

    a “last mile” solution for commuters to travel between a transit point (e.g., subway station) and their home or workplace, thereby reducing their...see in the rightmost subtree a drop in demand when the humidity is above 82 %, possibly because it is much less comfortable to take a leisurely ride

  18. Regional demand forecasting and simulation model: user's manual. Task 4, final report

    Energy Technology Data Exchange (ETDEWEB)

    Parhizgari, A M

    1978-09-25

    The Department of Energy's Regional Demand Forecasting Model (RDFOR) is an econometric and simulation system designed to estimate annual fuel-sector-region specific consumption of energy for the US. Its purposes are to (1) provide the demand side of the Project Independence Evaluation System (PIES), (2) enhance our empirical insights into the structure of US energy demand, and (3) assist policymakers in their decisions on and formulations of various energy policies and/or scenarios. This report provides a self-contained user's manual for interpreting, utilizing, and implementing RDFOR simulation software packages. Chapters I and II present the theoretical structure and the simulation of RDFOR, respectively. Chapter III describes several potential scenarios which are (or have been) utilized in the RDFOR simulations. Chapter IV presents an overview of the complete software package utilized in simulation. Chapter V provides the detailed explanation and documentation of this package. The last chapter describes step-by-step implementation of the simulation package using the two scenarios detailed in Chapter III. The RDFOR model contains 14 fuels: gasoline, electricity, natural gas, distillate and residual fuels, liquid gases, jet fuel, coal, oil, petroleum products, asphalt, petroleum coke, metallurgical coal, and total fuels, spread over residential, commercial, industrial, and transportation sectors.

  19. Differences in task demands influence the hemispheric lateralization and neural correlates of metaphor.

    Science.gov (United States)

    Yang, Fanpei Gloria; Edens, Jennifer; Simpson, Claire; Krawczyk, Daniel C

    2009-11-01

    This study investigated metaphor comprehension in the broader context of task-difference effects and manipulation of processing difficulty. We predicted that right hemisphere recruitment would show greater specificity to processing difficulty rather than metaphor comprehension. Previous metaphor processing studies have established that the left inferior frontal gyrus strongly correlates with metaphor comprehension but there has been controversy about whether right hemisphere (RH) involvement is specific for metaphor comprehension. Functional MRI data were recorded from healthy subjects who read novel metaphors, conventional metaphors, definition-like sentences, or literal sentences. We investigated metaphor processing in contexts where semantic judgment or imagery modulates linguistic judgment. Our findings support the position that the type of task rather than figurative language processing per se modulates the left inferior gyrus (LIFG). RH involvement was more influenced by processing difficulty and less by the novelty or figurativity of linguistic expressions. Our results suggest that figurative language processing depends upon the effects of task-type and processing difficulty on imaging results.

  20. Synchronous EMG activity in the piper frequency band reveals the corticospinal demand of walking tasks.

    Science.gov (United States)

    Clark, David J; Kautz, Steven A; Bauer, Andrew R; Chen, Yen-Ting; Christou, Evangelos A

    2013-08-01

    Evidence indicates that the frequency-domain characteristics of surface electromyogram (EMG) signals are modulated according to the contributing sources of neural drive. Modulation of inter-muscular EMG synchrony within the Piper frequency band (30-60 Hz) during movement tasks has been linked to drive from the corticospinal tract. However, it is not known whether EMG synchrony is sufficiently sensitive to detect task-dependent differences in the corticospinal contribution to leg muscle activation during walking. We investigated this question in seventeen healthy older men and women. It was hypothesized that, relative to typical steady state walking, Piper band EMG synchrony of the triceps surae muscle group would be reduced for dual-task walking (because of competition for cortical resources), similar for fast walking (because walking speed is directed by an indirect locomotor pathway rather than by the corticospinal tract), and increased when taking a long step (because voluntary gait pattern modifications are directed by the corticospinal tract). Each of these hypotheses was confirmed. These findings support the use of frequency-domain analysis of EMG in future investigations into the corticospinal contribution to control of healthy and disordered human walking.

  1. Synchronous EMG activity in the Piper frequency band reveals the corticospinal demand of walking tasks

    Science.gov (United States)

    Clark, David J.; Kautz, Steven A.; Bauer, Andrew R.; Chen, Yen-Ting; Christou, Evangelos A.

    2013-01-01

    Evidence indicates that the frequency-domain characteristics of surface electromyogram (EMG) signals are modulated according to the contributing sources of neural drive. Modulation of inter-muscular EMG synchrony within the Piper frequency band (30–60Hz) during movement tasks has been linked to drive from the corticospinal tract. However, it is not known whether EMG synchrony is sufficiently sensitive to detect task-dependent differences in the corticospinal contribution to leg muscle activation during walking. We investigated this question in seventeen healthy older men and women. It was hypothesized that, relative to typical steady state walking, Piper band EMG synchrony of the triceps surae muscle group would be reduced for dual-task walking (because of competition for cortical resources), similar for fast walking (because walking speed is directed by an intermediate locomotor pathway rather than by the corticospinal tract), and increased when taking a long step (because voluntary gait pattern modifications are directed by the corticospinal tract). Each of these hypotheses was confirmed. These findings support the use of frequency-domain analysis of EMG in future investigations into the corticospinal contribution to control of healthy and disordered human walking. PMID:23740367

  2. Effects of an attention demanding task on dynamic stability during treadmill walking

    Directory of Open Access Journals (Sweden)

    Troy Karen L

    2008-04-01

    Full Text Available Abstract Background People exhibit increased difficulty balancing when they perform secondary attention-distracting tasks while walking. However, a previous study by Grabiner and Troy (J. Neuroengineering Rehabil., 2005 found that young healthy subjects performing a concurrent Stroop task while walking on a motorized treadmill exhibited decreased step width variability. However, measures of variability do not directly quantify how a system responds to perturbations. This study re-analyzed data from Grabiner and Troy 2005 to determine if performing the concurrent Stroop task directly affected the dynamic stability of walking in these same subjects. Methods Thirteen healthy volunteers walked on a motorized treadmill at their self-selected constant speed for 10 minutes both while performing the Stroop test and during undisturbed walking. This Stroop test consisted of projecting images of the name of one color, printed in text of a different color, onto a wall and asking subjects to verbally identify the color of the text. Three-dimensional motions of a marker attached to the base of the neck (C5/T1 were recorded. Marker velocities were calculated over 3 equal intervals of 200 sec each in each direction. Mean variability was calculated for each time series as the average standard deviation across all strides. Both "local" and "orbital" dynamic stability were quantified for each time series using previously established methods. These measures directly quantify how quickly small perturbations grow or decay, either continuously in real time (local or discretely from one cycle to the next (orbital. Differences between Stroop and Control trials were evaluated using a 2-factor repeated measures ANOVA. Results Mean variability of trunk movements was significantly reduced during the Stroop tests compared to normal walking. Conversely, local and orbital stability results were mixed: some measures showed slight increases, while others showed slight decreases

  3. Current Situation and Demand of Rural Endowment Security in Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    Chunmei; LIU; Lutang; LI

    2013-01-01

    With intensification of population aging and rise in elderly dependency ratio,the demand for endowment security becomes higher and higher,particularly in rural areas.Taking Shaanxi Province as an example,the authors selected people older than 65 in 18 natural villages in north Shaanxi,south Shaanxi and Guanzhong.With the aid of survey data and related official statistical data,they made an evaluation of current situation of the rural endowment security in Shaanxi Province.Results indicate that home-based endowment is the major endowment method of rural elderly,but such method is influenced by family’s economic support ability and children’s support willingness,thus facing big demand gap.On the basis of analyzing gap problem,the authors recommended that government should increase financial and policy supports,optimize management and monitoring,actively develop non-government organizations,and promote socialization of rural endowment service.

  4. Prospective Analysis of the Current Demand of the Local Labour Market

    Directory of Open Access Journals (Sweden)

    Druzhinina Viktoriya V.

    2014-01-01

    Full Text Available The goal of the article lies in forecasting tendencies of the current demand of the local labour market on the basis of the method of statistical equations of dependencies and correlation and regression analysis for prolongation of relevant processes at the meso-level. The article considers a forecast model for co-ordination of dynamics of vacancies depending on socio-economic indicators of city development, which is formed on the basis of the method of statistical equations. This method requires identification of parameters of equations of single-factor dependencies and ratios of communication stability. On the basis of calculated values of these parameters and on the basis of economic and mathematical modelling of certain macro-economic indicators, the article builds equations of multiple regression, use of which would allow forecasting the current demand in the local labour market in the middle-term perspective. The prospect of further studies is forecasting the level of current balance of the local labour market, using the provided methods for forecasting the current supply.

  5. In a demanding task, three-handed manipulation is preferred to two-handed manipulation

    Science.gov (United States)

    Abdi, Elahe; Burdet, Etienne; Bouri, Mohamed; Himidan, Sharifa; Bleuler, Hannes

    2016-02-01

    Equipped with a third hand under their direct control, surgeons may be able to perform certain surgical interventions alone; this would reduce the need for a human assistant and related coordination difficulties. However, does human performance improve with three hands compared to two hands? To evaluate this possibility, we carried out a behavioural study on the performance of naive adults catching objects with three virtual hands controlled by their two hands and right foot. The subjects could successfully control the virtual hands in a few trials. With this control strategy, the workspace of the hands was inversely correlated with the task velocity. The comparison of performance between the three and two hands control revealed no significant difference of success in catching falling objects and in average effort during the tasks. Subjects preferred the three handed control strategy, found it easier, with less physical and mental burden. Although the coordination of the foot with the natural hands increased trial after trial, about two minutes of practice was not sufficient to develop a sense of ownership towards the third arm.

  6. Basic emotion processing and the adolescent brain: Task demands, analytic approaches, and trajectories of changes

    Directory of Open Access Journals (Sweden)

    Larissa B. Del Piero

    2016-06-01

    Full Text Available Early neuroimaging studies suggested that adolescents show initial development in brain regions linked with emotional reactivity, but slower development in brain structures linked with emotion regulation. However, the increased sophistication of adolescent brain research has made this picture more complex. This review examines functional neuroimaging studies that test for differences in basic emotion processing (reactivity and regulation between adolescents and either children or adults. We delineated different emotional processing demands across the experimental paradigms in the reviewed studies to synthesize the diverse results. The methods for assessing change (i.e., analytical approach and cohort characteristics (e.g., age range were also explored as potential factors influencing study results. Few unifying dimensions were found to successfully distill the results of the reviewed studies. However, this review highlights the potential impact of subtle methodological and analytic differences between studies, need for standardized and theory-driven experimental paradigms, and necessity of analytic approaches that are can adequately test the trajectories of developmental change that have recently been proposed. Recommendations for future research highlight connectivity analyses and non-linear developmental trajectories, which appear to be promising approaches for measuring change across adolescence. Recommendations are made for evaluating gender and biological markers of development beyond chronological age.

  7. Academic Task Demand in the 21st-Century, High-Stakes-Accountability School: Mapping the Journey from Poor [To Fair to Good to Great] to Excellent?

    Science.gov (United States)

    Szczesiul, Stacy Agee; Nehring, James; Carey, Theodore

    2015-01-01

    Drawing on theoretical and empirical research concerning the relationship between academic work and student learning, this article explores the following questions: What skills are required to execute the academic tasks teachers assign on a daily basis? How do teachers and administrators interpret the task demands represented in instructional…

  8. Academic Task Demand in the 21st-Century, High-Stakes-Accountability School: Mapping the Journey from Poor [To Fair to Good to Great] to Excellent?

    Science.gov (United States)

    Szczesiul, Stacy Agee; Nehring, James; Carey, Theodore

    2015-01-01

    Drawing on theoretical and empirical research concerning the relationship between academic work and student learning, this article explores the following questions: What skills are required to execute the academic tasks teachers assign on a daily basis? How do teachers and administrators interpret the task demands represented in instructional…

  9. Inflammatory bowel diseases: Current problems and future tasks.

    Science.gov (United States)

    Actis, Giovanni C; Pellicano, Rinaldo; Rosina, Floriano

    2014-08-06

    Current knowledge on inflammatory bowel disease (IBD) is mainly endorsed by controlled trials and epidemiologic studies. Yet, we seldom look at the messages from real-world practice. Among a patient population followed since 2008, we looked at an unselected sample of 64 IBD patients [26 Crohn's disease (CD) and 38 ulcerative colitis (UC)] who had been seen as out-patients in the last year. Inducing remission, mesalamines (86% for UC/69% for CD/33%-16% as MMX formulation) prevailed as prescriptions; steroids (55%/19% for UC/CD) ranked second. Prescription of third-party drugs (antibiotics, NSAIDs, biologics) and adherence, were issues in the maintenance. 34% of CD, and 23% of UC patients showed accompanying immunologic diseases: CD-associated familiar psoriasis (4:9) ranked first. Main Message. The association between IBD (CD mainly) and psoriasis, now found in our practice, matches current basic science gathering IBD together with psoriasis (and perhaps chronic respiratory disease) under the comprehensive term "barrier organ disease" wherein an epithelial surface with sensor systems rules contacts between outer antigens and a reactive underneath tissue, with the balance between inflammation and quiescence kept at any time by mucosal permeability. IBD is thus viewed as a polyfactorial/polygenic/syndromic disorder, embedded into a galaxy of immune conditions offering multiple points of attack. This mindset of splitting the IBDs into pathogenic categories may allow overcoming the uniformly targeting of a single cytokine by biological drugs, in favor of demarcating the boundaries between different disease-subtype-specific indications, and paving the way to future personalized strategies.

  10. Inflammatory bowel diseases: Current problems and future tasks

    Institute of Scientific and Technical Information of China (English)

    Giovanni; C; Actis; Floriano; Rosina; Rinaldo; Pellicano

    2014-01-01

    Current knowledge on inflammatory bowel disease(IBD)is mainly endorsed by controlled trials and epidemiologic studies. Yet,we seldom look at the messages from real-world practice. Among a patient population followed since2008,we looked at an unselected sample of 64 IBD patients [26 Crohn’s disease(CD) and 38 ulcerative colitis(UC)] who had been seen as out-patients in the last year.Inducing remission,mesalamines(86% for UC/69% for CD/33%-16% as MMX formulation) prevailed as prescrip-tions; steroids(55%/19% for UC/CD) ranked second.Prescription of third-party drugs(antibiotics,NSAIDs,biologics) and adherence,were issues in the maintenance.34% of CD,and 23% of UC patients showed accompany-ing immunologic diseases: CD-associated familiar psoriasis(4:9) ranked first. Main Message. The association between IBD(CD mainly) and psoriasis,now found in our practice,matches current basic science gathering IBD together with psoriasis(and perhaps chronic respiratory disease) under the comprehensive term "barrier organ disease" wherein an epithelial surface with sensor system srules contacts between outer antigens and a reactive underneath tissue,with the balance between inflammation and quiescence kept at any time by mucosal permeability.IBD is thus viewed as a polyfactorial/polygenic/syndromic disorder,embedded into a galaxy of immune conditions offering multiple points of attack. This mindset of splitting the IBDs into pathogenic categories may allow overcoming the uniformly targeting of a single cytokine by biological drugs,in favor of demarcating the boundaries between different disease-subtype-specific indications,and paving the way to future personalized strategies.

  11. Task demands modulate decision and eye movement responses in the chimeric face test: examining the right hemisphere processing account

    Directory of Open Access Journals (Sweden)

    Jason eCoronel

    2014-03-01

    Full Text Available A large and growing body of work, conducted in both brain-intact and brain-damaged populations, has used the free viewing chimeric face test as a measure of hemispheric dominance for the extraction of emotional information from faces. These studies generally show that normal right-handed individuals tend to perceive chimeric faces as more emotional if the emotional expression is presented on the half of the face to the viewer’s left (left hemiface. However, the mechanisms underlying this lateralized bias remain unclear. Here, we examine the extent to which this bias is driven by right hemisphere processing advantages versus default scanning biases in a unique way -- by changing task demands. In particular, we compare the original task with one in which right-hemisphere-biased processing cannot provide a decision advantage. Our behavioral and eye-movement data are inconsistent with the predictions of a default scanning bias account and support the idea that the left hemiface bias found in the chimeric face test is largely due to strategic use of right hemisphere processing mechanisms.

  12. CURRENT STATUS OF AMAZONIAN ORNAMENTAL FISH FROM PERU WITH HIGHER DEMAND OF EXPORTATION

    Directory of Open Access Journals (Sweden)

    Ortiz, N.

    2008-01-01

    Full Text Available Current status of Amazonian ornamental fish from Peru with higher demand of exportation was analyzed. The ornamental freshwater fishes from Peru with higher demand are Osteoglossum bicirrhosum (Cuvier, 1829 (Osteoglossidae, followed by ray Potamotrygon motoro (Müller & Henle, 1841 (Potamotrygonidae. Main ornamental and continental fish family that exports is Loriicaridae (Siluriformes. The vast continental and ornamental fish from Peru with higher demand are climate tropical and clear waters with pH de 6.5 a 7.5. Four species (Potamotrygon falkneri Castex & Maciel, 1963, Acanthicus adonis Isbrücker & Nijssen, 1988, Peckoltia vittata (Steindachner, 1881 and Corydoras julii Steindachner, 1906 that exists are not reported on check-list of continental fishes from Peru performed by Ortega & Vari (1986 and, Chang & Ortega (1995. C. julii, is the unique fish not found in the ornamental fish list from Peru performed by “Instituto de Investigación de la Amazonia Peruana” (IIAP and “Comisión para la Promoción de Exportaciones” (PROMPEX. O. bicirrhosum, P. motoro, Corydoras arcuatus Elwin 1938 and C. julii are fish with more data obtained. Fish with less data obtained was Brachyplatystoma tigrinum (Britski, 1981. Main problematic observed on ornamental continental Peruvian fish since an ecological point of view, are pollution of fish environment, mainly by heavy metals, alteration on great scale from habitat, where lives and surroundings, and also, introduction alien species. The main problem that suffer commercialization of ornamental fish as in other species, is regulation and foment by part of authority respect to bio-business initiatives bio-business; generating confusion between user and lack of motivation legalities of these bionegocio.

  13. ERP indices of persisting and current inhibitory control: a study of saccadic task switching.

    Science.gov (United States)

    Mueller, S C; Swainson, R; Jackson, G M

    2009-03-01

    Previous studies have found that inhibition of a biologically dominant prepotent response tendency is required during the execution of a less familiar, non-prepotent response. However, the lasting impact of this inhibition and the cognitive mechanisms to flexibly switch between prepotent and non-prepotent responses are poorly understood. We examined the neurophysiological (ERP) correlates of switching between prosaccade and antisaccade responses in 22 healthy volunteers. The behavioural data showed significant switch costs in terms of response latency for the prosaccade task only. These costs occurred exclusively in trials when preparation for the switch was limited to 300 ms, suggesting that inhibition of the prepotent prosaccade task either passively dissipated or was actively overcome during the longer 1000 ms preparation interval. In the neurophysiological data, a late frontal negativity (LFN) was visible during preparation for a switch to the prosaccade task that was absent when switching to the antisaccade task, which may reflect the overcoming of persisting inhibition. During task implementation both saccade types were associated with a late parietal positivity (LPP) for switch relative to repetition trials, possibly indicating attentional reorienting to the switched-to task, and visible only with short preparation intervals. When the prosaccade and antisaccade task were contrasted directly during task implementation, the antisaccade task exhibited increased stimulus-locked N2 and decreased P3 amplitudes indicative of active inhibition. The present findings indicate that neurophysiological markers of persisting and current inhibition can be revealed using a prosaccade/antisaccade-switching task.

  14. JSC Advanced Curation: Research and Development for Current Collections and Future Sample Return Mission Demands

    Science.gov (United States)

    Fries, M. D.; Allen, C. C.; Calaway, M. J.; Evans, C. A.; Stansbery, E. K.

    2015-01-01

    Curation of NASA's astromaterials sample collections is a demanding and evolving activity that supports valuable science from NASA missions for generations, long after the samples are returned to Earth. For example, NASA continues to loan hundreds of Apollo program samples to investigators every year and those samples are often analyzed using instruments that did not exist at the time of the Apollo missions themselves. The samples are curated in a manner that minimizes overall contamination, enabling clean, new high-sensitivity measurements and new science results over 40 years after their return to Earth. As our exploration of the Solar System progresses, upcoming and future NASA sample return missions will return new samples with stringent contamination control, sample environmental control, and Planetary Protection requirements. Therefore, an essential element of a healthy astromaterials curation program is a research and development (R&D) effort that characterizes and employs new technologies to maintain current collections and enable new missions - an Advanced Curation effort. JSC's Astromaterials Acquisition & Curation Office is continually performing Advanced Curation research, identifying and defining knowledge gaps about research, development, and validation/verification topics that are critical to support current and future NASA astromaterials sample collections. The following are highlighted knowledge gaps and research opportunities.

  15. The physiological demand of pulling a rescue sled across the mud and the impact experience has on this task.

    Science.gov (United States)

    Milligan, Gemma S; House, James R; Tipton, Michael J

    2017-01-01

    To establish a Physical Employment Standard for tasks with high physical demands, it is important to determine the physiological requirements. One such task for the UK Coastguard is mud rescue. To quantify the physiological demand of pulling a rescue sled across estuary mud, and determine whether rescuer experience has an impact on the physiological demand of this task. Forty participants walked 150 m in 3 minutes across estuary mud. Following 3 minute rest, they walked 150 m pulling a rescue sled (61 kg) in pairs (based on experience). Experienced rescuers had a total oxygen consumption approximately 24% lower than those inexperienced in the task. Relative oxygen consumption (V̇O2) was significantly (p < 0.05) greater in the non-experienced (mean [SD]; 42.90 [6.55] mL.kg-1.min-1) compared to the experienced group (32.85 [5.79] mL.kg-1.min-1) when controlled for pace. Required V̇O2 for various speeds were predicted based on non-experienced participants and assessed for agreement. LoA (95%) mean±difference was 0.0003 ± 3.48 mL.kg-1.min-1, with a CV of 2.30%. For tasks that require a high relative V̇O2, such as mud rescue, the minimum level of fitness at entry should be based upon the metabolic demands measured on those who are inexperienced.

  16. Task-specific effect of transcranial direct current stimulation on motor learning

    Directory of Open Access Journals (Sweden)

    Cinthia Maria Saucedo Marquez

    2013-07-01

    Full Text Available Transcranial direct current stimulation (tDCS is a relatively new non-invasive brain stimulation technique that modulates neural processes. When applied to the human primary motor cortex (M1, tDCS has beneficial effects on motor skill learning and consolidation in healthy controls and in patients. However, it remains unclear whether tDCS improves motor learning in a general manner or whether these effects depend on which motor task is acquired. Here we compare whether the effect of tDCS differs when the same individual acquires (1 a Sequential Finger Tapping Task (SEQTAP and (2 a Visual Isometric Pinch Force Task (FORCE. Both tasks have been shown to be sensitive to tDCS applied over M1, however, the underlying processes mediating learning and memory formation might benefit differently from anodal-tDCS. Thirty healthy subjects were randomly assigned to an anodal-tDCS group or sham-group. Using a double-blind, sham-controlled cross-over design, tDCS was applied over M1 while subjects acquired each of the motor tasks over 3 consecutive days, with the order being randomized across subjects. We found that anodal-tDCS affected each task differently: The SEQTAP task benefited from anodal-tDCS during learning, whereas the FORCE task showed improvements only at retention. These findings suggest that anodal tDCS applied over M1 appears to have a task-dependent effect on learning and memory formation.

  17. Occupational exposure to electric fields and currents associated with 110 kV substation tasks.

    Science.gov (United States)

    Korpinen, Leena H; Kuisti, Harri A; Tarao, Hiroo; Elovaara, Jarmo A

    2012-07-01

    The main aim of this study was to investigate occupational exposure to electric fields, and current densities and contact currents associated with tasks at air-insulated 110 kV substations and analyze if the action value of EU Directive 2004/40/EC was exceeded. Four workers volunteered to simulate the following tasks: Task (A) maintenance of an operating device of a disconnector at ground or floor level, Task (B) maintenance of an operating device of a circuit breaker at ground or floor level, Task (C) breaker head maintenance from a man hoist, and Task (D) maintenance of an operating device of a circuit breaker from a service platform. The highest maximum average current density in the neck was 1.8 mA/m(2) (calculated internal electric field 9.0-18.0 mV/m) and the highest contact current was 79.4 µA. All measured values at substations were lower than the limit value (10 mA/m(2)) of the EU Directive 2004/40/EC and the 2010 basic restrictions (0.1 and 0.8 V/m for central nervous system tissues of the head, and all tissues of the head and body, respectively) of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Copyright © 2012 Wiley Periodicals, Inc.

  18. Discriminating hand gesture motor imagery tasks using cortical current density estimation.

    Science.gov (United States)

    Edelman, Bradley; Baxter, Bryan; He, Bin

    2014-01-01

    Current EEG based brain computer interface (BCI) systems have achieved successful control in up to 3 dimensions; however the current paradigm may be unnatural for many rehabilitative and recreational applications. Therefore there is a great need to find motor imagination (MI) tasks that are realistic for output device control. In this paper we present our results on classifying hand gesture MI tasks, including right hand flexion, extension, supination and pronation using a novel EEG inverse imaging approach. By using both temporal and spatial specificity in the source domain we were able to separate MI tasks with up to 95% accuracy for binary classification of any two tasks compared to a maximum of only 79% in the sensor domain.

  19. The interaction of approach-alcohol action tendencies, working memory capacity, and current task goals predicts the inability to regulate drinking behavior.

    Science.gov (United States)

    Sharbanee, Jason M; Stritzke, Werner G K; Wiers, Reinout W; Young, Paul; Rinck, Mike; MacLeod, Colin

    2013-09-01

    The inability to regulate alcohol consumption has been attributed to an imbalance between stimulus-driven behavioral biases, or action tendencies, and the ability to exert goal-directed control, or working memory capacity (WMC). Previous research assessing the interaction between these variables has not considered the effect of whether individuals' current goals or task demands require goal-directed control. Our aim was to examine the potential interaction of appetitive action tendencies and the ability to exert control over these action tendencies as a function of whether task demands require applying control for successful task completion. Two groups of social drinkers (n = 40 per group) who differed in their ability to regulate their alcohol consumption completed a novel variant of the Approach-Avoidance Task (AAT), which separately assessed approach and avoid trials. The approach and avoidance responses differentially require goal-directed control, depending on whether the task-relevant response is incongruent with the stimulus-driven action tendency. Results indicated that (a) group differences in AAT indices were only observed on trials that required an avoidance movement, which are trials where the task-relevant response would be incongruent with an approach action tendency, and (b) the extent of the group differences for these avoidance trials was moderated by individual differences in WMC, such that problem drinkers with lower WMC showed greater behavioral bias toward alcohol than those with higher WMC. These findings suggest that difficulties in regulating alcohol consumption arise from a complex interaction of action-tendencies, WMC, and current goals or task demands.

  20. Bioprinting of artificial blood vessels: current approaches towards a demanding goal.

    Science.gov (United States)

    Hoch, Eva; Tovar, Günter E M; Borchers, Kirsten

    2014-11-01

    Free-form fabrication techniques, often referred to as '3D printing', are currently tested with regard to the processing of biological and biocompatible materials in general and for fabrication of vessel-like structures in particular. Such computer-controlled methods assemble 3D objects by layer-wise deposition or layer-wise cross-linking of materials. They use, for example, nozzle-based deposition of hydrogels and cells, drop-on-demand inkjet-printing of cell suspensions with subsequent cross-linking, layer-by-layer cross-linking of synthetic or biological polymers by selective irradiation with light and even laser-induced deposition of single cells. The need of vessel-like structures has become increasingly crucial for the supply of encapsulated cells for 3D tissue engineering, or even with regard to future application such as vascular grafts. The anticipated potential of providing tubes with tailored branching geometries made of biocompatible or biological materials pushes future visions of patient-specific vascularized tissue substitutions, tissue-engineered blood vessels and bio-based vascular grafts. We review here the early attempts of bringing together innovative free-form manufacturing processes with bio-based and biodegradable materials. The presented studies provide many important proofs of concepts such as the possibility to integrate viable cells into computer-controlled processes and the feasibility of supplying cells in a hydrogel matrix by generation of a network of perfused channels. Several impressive results in the generation of complex shapes and high-aspect-ratio tubular structures demonstrate the potential of additive assembly methods. Yet, it also becomes obvious that there remain major challenges to simultaneously match all material requirements in terms of biological functions (cell function supporting properties), physicochemical functions (mechanical properties of the printed material) and process-related (viscosity, cross

  1. Modeling and managing urban water demand through smart meters: Benefits and challenges from current research and emerging trends

    Science.gov (United States)

    Cominola, A.; Giuliani, M.; Castelletti, A.; Piga, D.; Rizzoli, A. E.

    2015-12-01

    Urban population growth, climate and land use change are expected to boost residential water demand in urban contexts in the next decades. In such a context, developing suitable demand-side management strategies is essential to meet future water demands, pursue water savings, and reduce the costs for water utilities. Yet, the effectiveness of water demand management strategies (WDMS) relies on our understanding of water consumers' behavior, their consumption habits, and the water use drivers. While low spatial and temporal resolution water consumption data, as traditionally gathered for billing purposes, hardly support this understanding, the advent of high-resolution, smart metering technologies allowed for quasi real-time monitoring water consumption at the single household level. This, in turn, is advancing our ability in characterizing consumers' behavior, modeling, and designing user-oriented residential water demand management strategies. Several water smart metering programs have been rolled-out in the last two decades worldwide, addressing one or more of the following water demand management phases: (i) data gathering, (ii) water end-uses characterization, (iii) user modeling, (iv) design and implementation of personalized WDMS. Moreover, the number of research studies in this domain is quickly increasing and big economic investments are currently being devoted worldwide to smart metering programs. With this work, we contribute the first comprehensive review of more than 100 experiences in the field of residential water demand modeling and management, and we propose a general framework for their classification. We revise consolidated practices, identify emerging trends and highlight the challenges and opportunities for future developments given by the use of smart meters advancing residential water demand management. Our analysis of the status quo of smart urban water demand management research and market constitutes a structured collection of information

  2. Alternative methods for skin irritation testing: the current status : ECVAM skin irritation task force report 1

    NARCIS (Netherlands)

    Botham, P.A.; Earl, L.K.; Fentem, J.H.; Roguet, R.; Sandt, J.J.M.

    1998-01-01

    The ECVAM Skin Irritation Task Force was established in November 1996, primarily to prepare a report on the current status of the development and validation of alternative tests for skin irritation and corrosion and, in particular, to identify any appropriate non-animal tests for predicting human

  3. Alternative methods for skin irritation testing: the current status : ECVAM skin irritation task force report 1

    NARCIS (Netherlands)

    Botham, P.A.; Earl, L.K.; Fentem, J.H.; Roguet, R.; Sandt, J.J.M.

    1998-01-01

    The ECVAM Skin Irritation Task Force was established in November 1996, primarily to prepare a report on the current status of the development and validation of alternative tests for skin irritation and corrosion and, in particular, to identify any appropriate non-animal tests for predicting human sk

  4. The Role of the Supplementary Motor Region in Overt Reading: Evidence for Differential Processing in SMA-Proper and Pre-SMA as a Function of Task Demands.

    Science.gov (United States)

    Cummine, Jacqueline; Hanif, Wahab; Dymouriak-Tymashov, Inna; Anchuri, Kavya; Chiu, Stephanie; Boliek, Carol A

    2017-03-04

    A differentiation in function between the pre-SMA (i.e., cognitive load) and the SMA-proper (i.e., motor execution) has been described (Zhang et al., Cereb Cortex 22:99-111, 2012). These differential SMA functions may be influential in overt reading tasks. The present study examined the relationships between various segments of the SMA and overt reading through the modulation of task demands in an effort to explore the complexity of the print-to-speech network. Skilled reading adults (N = 15) took part in five overt reading tasks: pure regular word reading, pure exception word reading, mixed regular word and exception word reading, go/no-go reading with nonword foils and go/no-go reading with pseudohomophone foils. Five regions of interest that spanned the pre-SMA to the SMA-proper were isolated. Behaviour-function relationships were tested to examine the associations between performance (response time) and brain activity (percent signal change). Further, the coherence between feedforward (SMA) and feedback (supramarginal gyrus) regions were explored to further refine the print-to-speech network. We found that the pre-SMA was related to cognitively demanding tasks (go/no-go with pseudohomophones), whereas the SMA-proper was related to an automatized task (pure regular words). Notably, only those tasks that required information from the feedback system (i.e., mixed word lists, go/no-go tasks) showed connections between SMA regions and the supramarginal gyrus, which is in line with the role of feedback and feedforward systems in the print-to-speech network. Together, these results support the notion that the pre-SMA and SMA-proper are sensitive to reading tasks that differentially invoke higher cognitive resources (mixed word lists, go/no-go) versus automatized articulation (pure lists), respectively. We discuss our findings in the context of print-to-speech neural networks.

  5. The Current Situation and Prospect of Chinese Aluminum Use Carbon Supply and Demand

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>China has basically eliminated the practice of aluminum production with self-baking cell. The demand for carbon anode for aluminum has been growing in recent years corresponding to the output of aluminum,which has promoted the rapid growth of carbon anode industry.

  6. Enhanced motor learning following task-concurrent dual transcranial direct current stimulation.

    Directory of Open Access Journals (Sweden)

    Sophia Karok

    Full Text Available OBJECTIVE: Transcranial direct current stimulation (tDCS of the primary motor cortex (M1 has beneficial effects on motor performance and motor learning in healthy subjects and is emerging as a promising tool for motor neurorehabilitation. Applying tDCS concurrently with a motor task has recently been found to be more effective than applying stimulation before the motor task. This study extends this finding to examine whether such task-concurrent stimulation further enhances motor learning on a dual M1 montage. METHOD: Twenty healthy, right-handed subjects received anodal tDCS to the right M1, dual tDCS (anodal current over right M1 and cathodal over left M1 and sham tDCS in a repeated-measures design. Stimulation was applied for 10 mins at 1.5 mA during an explicit motor learning task. Response times (RT and accuracy were measured at baseline, during, directly after and 15 mins after stimulation. Motor cortical excitability was recorded from both hemispheres before and after stimulation using single-pulse transcranial magnetic stimulation. RESULTS: Task-concurrent stimulation with a dual M1 montage significantly reduced RTs by 23% as early as with the onset of stimulation (p<0.01 with this effect increasing to 30% at the final measurement. Polarity-specific changes in cortical excitability were observed with MEPs significantly reduced by 12% in the left M1 and increased by 69% in the right M1. CONCLUSION: Performance improvement occurred earliest in the dual M1 condition with a stable and lasting effect. Unilateral anodal stimulation resulted only in trendwise improvement when compared to sham. Therefore, task-concurrent dual M1 stimulation is most suited for obtaining the desired neuromodulatory effects of tDCS in explicit motor learning.

  7. Is effect of transcranial direct current stimulation on visuomotor coordination dependent on task difficulty?

    Directory of Open Access Journals (Sweden)

    Yong Hyun Kwon

    2015-01-01

    Full Text Available Transcranial direct current stimulation (tDCS, an emerging technique for non-invasive brain stimulation, is increasingly used to induce changes in cortical excitability and modulate motor behavior, especially for upper limbs. The purpose of this study was to investigate the effects of tDCS of the primary motor cortex on visuomotor coordination based on three levels of task difficulty in healthy subjects. Thirty-eight healthy participants underwent real tDCS or sham tDCS. Using a single-blind, sham-controlled crossover design, tDCS was applied to the primary motor cortex. For real tDCS conditions, tDCS intensity was 1 mA while stimulation was applied for 15 minutes. For the sham tDCS, electrodes were placed in the same position, but the stimulator was turned off after 5 seconds. Visuomotor tracking task, consisting of three levels (levels 1, 2, 3 of difficulty with higher level indicating greater difficulty, was performed before and after tDCS application. At level 2, real tDCS of the primary motor cortex improved the accurate index compared to the sham tDCS. However, at levels 1 and 3, the accurate index was not significantly increased after real tDCS compared to the sham tDCS. These findings suggest that tasks of moderate difficulty may improve visuomotor coordination in healthy subjects when tDCS is applied compared with easier or more difficult tasks.

  8. Is effect of transcranial direct current stimulation on visuomotor coordination dependent on task dififculty?

    Institute of Scientific and Technical Information of China (English)

    Yong Hyun Kwon; Kyung Woo Kang; Sung Min Son; Na Kyung Lee

    2015-01-01

    Transcranial direct current stimulation (tDCS), an emerging technique for non-invasive brain stimulation, is increasingly used to induce changes in cortical excitability and modulate motor behavior, especially for upper limbs. The purpose of this study was to investigate the effects of tDCS of the primary motor cortex on visuomotor coordination based on three levels of task difficulty in healthy subjects. Thirty-eight healthy participants underwent real tDCS or sham tDCS. Using a single-blind, sham-controlled crossover design, tDCS was applied to the primary motor cortex. For real tDCS conditions, tDCS intensity was 1 mA while stimulation was applied for 15 minutes. For the sham tDCS, electrodes were placed in the same position, but the stimu-lator was turned off after 5 seconds. Visuomotor tracking task, consisting of three levels (levels 1, 2, 3) of dififculty with higher level indicating greater dififculty, was performed before and after tDCS application. At level 2, real tDCS of the primary motor cortex improved the accurate index compared to the sham tDCS. However, at levels 1 and 3, the accurate index was not signiifcantly increased after real tDCS compared to the sham tDCS. These ifndings suggest that tasks of mod-erate dififculty may improve visuomotor coordination in healthy subjects when tDCS is applied compared with easier or more dififcult tasks.

  9. Key tasks in healthcare marketing: assessing importance and current level of knowledge.

    Science.gov (United States)

    Kennett, Pamela A; Henson, Steve W; Crow, Stephen M; Hartman, Sandra J

    2005-01-01

    When examining the healthcare industry, the need for continuing education in internal functions (i.e., HR management) has been documented. However, equally important to success in the healthcare industry are external functions such as marketing. In an expansion of research on internally focused functions, we report findings from an exploratory study designed to examine the perceptions of executives about managerial skill needs in the externally focused area of marketing. Specifically, we examine eight key tasks in marketing and ask executives to rate the level of knowledge required for each and then to assess current, or actual, levels of knowledge in the field. Findings suggest that pricing strategy, product strategy, and segmentation and targeting were the tasks that require the most knowledge for healthcare marketers, and that they do, in fact, perceive various gaps in all of the areas examined. Implications and suggestions for future research are provided.

  10. Transfer-Appropriate Processing in Recognition Memory: Perceptual and Conceptual Effects on Recognition Memory Depend on Task Demands

    Science.gov (United States)

    Parks, Colleen M.

    2013-01-01

    Research examining the importance of surface-level information to familiarity in recognition memory tasks is mixed: Sometimes it affects recognition and sometimes it does not. One potential explanation of the inconsistent findings comes from the ideas of dual process theory of recognition and the transfer-appropriate processing framework, which…

  11. Changes in Elementary Mathematics Teachers' Understanding of Cognitive Demand: When Adapting, Creating, and Using Mathematical Performance Tasks

    Science.gov (United States)

    Jamieson, Thad Spencer

    2015-01-01

    The use of mathematics performance tasks can provide a window into how a student is applying mathematics to various situations, how they are reasoning mathematically and how they are applying conceptual knowledge through problem solving and critical thinking. The purpose of this study was to investigate, according to the elementary mathematics…

  12. Electric Vehicles in Colorado: Anticipating Consumer Demand for Direct Current Fast Charging

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric W. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rames, Clement L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-07-01

    To support the State of Colorado in planning for growth in direct current fast charging (DCFC) for electric vehicles, the National Renewable Energy Laboratory (NREL) has partnered with the Regional Air Quality Council (RAQC) and the Colorado Department of Transportation (CDOT) to analyze a number of DCFC investment scenarios. NREL analyzed existing electric vehicle registration data from IHS Markit (IHS) to highlight early trends in the electric vehicle market, which were compared with sales forecasts predicting large growth in the Colorado electric vehicle market. Electric vehicle forecasts were then used to develop future DCFC scenarios to be evaluated in a simulation environment to estimate consumer benefits of the hypothetical DCFC networks in terms of increased driving range and electric vehicle miles traveled (eVMT). Simulated utilization of the hypothetical DCFC networks was analyzed for geographic trends, particularly for correlations with vehicle electric range. Finally, a subset of simulations is presented for consumers with potentially inconsistent access to charging at their home location and presumably greater reliance on public DCFC infrastructure.

  13. Anodal Transcranial Direct Current Stimulation Does Not Facilitate Dynamic Balance Task Learning in Healthy Old Adults

    Science.gov (United States)

    Kaminski, Elisabeth; Hoff, Maike; Rjosk, Viola; Steele, Christopher J.; Gundlach, Christopher; Sehm, Bernhard; Villringer, Arno; Ragert, Patrick

    2017-01-01

    Older adults frequently experience a decrease in balance control that leads to increased numbers of falls, injuries and hospitalization. Therefore, evaluating older adults’ ability to maintain balance and examining new approaches to counteract age-related decline in balance control is of great importance for fall prevention and healthy aging. Non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) have been shown to beneficially influence motor behavior and motor learning. In the present study, we investigated the influence of tDCS applied over the leg area of the primary motor cortex (M1) on balance task learning of healthy elderly in a dynamic balance task (DBT). In total, 30 older adults were enrolled in a cross-sectional, randomized design including two consecutive DBT training sessions. Only during the first DBT session, either 20 min of anodal tDCS (a-tDCS) or sham tDCS (s-tDCS) were applied and learning improvement was compared between the two groups. Our data showed that both groups successfully learned to perform the DBT on both training sessions. Interestingly, between-group analyses revealed no difference between the a-tDCS and the s-tDCS group regarding their level of task learning. These results indicate that the concurrent application of tDCS over M1 leg area did not elicit DBT learning enhancement in our study cohort. However, a regression analysis revealed that DBT performance can be predicted by the kinematic profile of the movement, a finding that may provide new insights for individualized approaches of treating balance and gait disorders. PMID:28197085

  14. Anodal Transcranial Direct Current Stimulation Does Not Facilitate Dynamic Balance Task Learning in Healthy Old Adults.

    Science.gov (United States)

    Kaminski, Elisabeth; Hoff, Maike; Rjosk, Viola; Steele, Christopher J; Gundlach, Christopher; Sehm, Bernhard; Villringer, Arno; Ragert, Patrick

    2017-01-01

    Older adults frequently experience a decrease in balance control that leads to increased numbers of falls, injuries and hospitalization. Therefore, evaluating older adults' ability to maintain balance and examining new approaches to counteract age-related decline in balance control is of great importance for fall prevention and healthy aging. Non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) have been shown to beneficially influence motor behavior and motor learning. In the present study, we investigated the influence of tDCS applied over the leg area of the primary motor cortex (M1) on balance task learning of healthy elderly in a dynamic balance task (DBT). In total, 30 older adults were enrolled in a cross-sectional, randomized design including two consecutive DBT training sessions. Only during the first DBT session, either 20 min of anodal tDCS (a-tDCS) or sham tDCS (s-tDCS) were applied and learning improvement was compared between the two groups. Our data showed that both groups successfully learned to perform the DBT on both training sessions. Interestingly, between-group analyses revealed no difference between the a-tDCS and the s-tDCS group regarding their level of task learning. These results indicate that the concurrent application of tDCS over M1 leg area did not elicit DBT learning enhancement in our study cohort. However, a regression analysis revealed that DBT performance can be predicted by the kinematic profile of the movement, a finding that may provide new insights for individualized approaches of treating balance and gait disorders.

  15. Medication therapy management services in North Carolina community pharmacies: current practice patterns and projected demand.

    Science.gov (United States)

    Hansen, Richard A; Roth, Mary T; Brouwer, Emily S; Herndon, Susan; Christensen, Dale B

    2006-01-01

    To evaluate the types of cognitive services offered and the number of patients being served in community pharmacies, determine the number of pharmacies that plan to offer medication therapy management (MTM) services under the Medicare Part D prescription drug benefit, and assess whether current and expected practices will meet the potential needs of enrollees. Cross-sectional study. North Carolina in January 2005. 1,593 community pharmacy managers. Survey using a Web-based tool. Provision of cognitive services and number of patients for whom services are provided. A total of 262 (16%) pharmacy managers provided usable responses. Approximately 42% of respondents (n = 110) indicated that they provide some type of cognitive service. Comprehensive MTM services, or services consistent with the professionwide consensus definition, were provided by 31% of respondents (n = 81). Independent pharmacies were more likely to offer some type of service compared with chain pharmacies (58% versus 31%, respectively; P Pharmacy managers with a doctor of pharmacy degree were less likely than pharmacy managers with a bachelor's degree to offer services in their pharmacies (P = .02), and pharmacies with pharmacists on staff who had received certificate training were more likely to offer cognitive services (P = .03). Of all respondents, 28% (n = 73) indicated that they planned to offer MTM services under the Medicare Part D prescription drug benefit. Comparing these results with those of a 1999 survey of North Carolina pharmacists that used some of the same items, the percentage of community pharmacies that provide cognitive services has increased in the intervening years but remains low. Among the services being offered in 2005, most were focused on patient education and training, coordinating and integrating care, and medication regimen reviews. Implementation of MTM services under the Medicare Part D prescription drug benefit should hasten the development and offering of these

  16. Temporal cortex direct current stimulation enhances performance on a visual recognition memory task in Alzheimer disease.

    Science.gov (United States)

    Boggio, P S; Khoury, L P; Martins, D C S; Martins, O E M S; de Macedo, E C; Fregni, F

    2009-04-01

    Several studies have reported that transcranial direct current stimulation (tDCS), a non-invasive method of neuromodulation, enhances some aspects of working memory in healthy and Parkinson disease subjects. The aim of this study was to investigate the impact of anodal tDCS on recognition memory, working memory and selective attention in Alzheimer disease (AD). Ten patients with diagnosis of AD received three sessions of anodal tDCS (left dorsolateral prefrontal cortex, left temporal cortex and sham stimulation) with an intensity of 2 mA for 30 min. Sessions were performed in different days in a randomised order. The following tests were assessed during stimulation: Stroop, Digit Span and a Visual Recognition Memory task (VRM). The results showed a significant effect of stimulation condition on VRM (p = 0.0085), and post hoc analysis showed an improvement after temporal (p = 0.01) and prefrontal (p = 0.01) tDCS as compared with sham stimulation. There were no significant changes in attention as indexed by Stroop task performance. As far as is known, this is the first trial showing that tDCS can enhance a component of recognition memory. The potential mechanisms of action and the implications of these results are discussed.

  17. No transfer between conditions in balance training regimes relying on tasks with different postural demands: Specificity effects of two different serious games.

    Science.gov (United States)

    Naumann, Tim; Kindermann, Stefan; Joch, Michael; Munzert, Jörn; Reiser, Mathias

    2015-03-01

    Despite the increasing use of video games involving whole body movements to enhance postural control in health prevention and rehabilitation, there is no consistent proof that training effects actually transfer to other balance tasks. The present study aimed to determine whether training effects on two different video-game-based training devices were task-specific or could be transferred to either postural control in quiet stance or to performance on the other device. 37 young healthy adults were split into three groups: two intervention groups that trained for 30min on either the Nintendo(®) Wii Fit Balance Board or the MFT Challenge Disc(®) three times per week for 4 weeks and a control group that received no training. All games require participants to control virtual avatars by shifting the center of mass in different directions. Both devices differ in their physical properties. The Balance Board provides a stable surface, whereas the Challenge Disc can be tilted in all directions. Dependent variables were the game scores on both devices and the center of pressure (COP) displacements measured via force plate. At posttest, both intervention groups showed significant increases in performance on the trained games compared to controls. However, there were no relevant transfer effects to performance on the untrained device and no changes in COP path length in quiet stance. These results suggest that training effects on both devices are highly specific and do not transfer to tasks with different postural demands.

  18. Current Situation of Information Demand of Farmers in Taihang Mountain Area: A Case Study of Pingshan County in Hebei Province

    Institute of Scientific and Technical Information of China (English)

    Lipeng; GUO; Haiyan; CAI

    2014-01-01

    Since the reform and opening-up,economy of mountain areas in China has realized considerable development.However,due to such factors as terrain,traffic,and individual differences,compared with plain and coastal areas,mountain areas still lag far behind.In recent years,informationization construction of China develops rapidly,but it nearly stagnates in mountain rural areas.Information has become an essential factor restricting economic development of rural areas.Based on the survey of current information demand of farmers carried out in Pingshan County in Hebei Province in 2010,this study came up with relevant recommendations,in order to speed up development of rural economic in mountain areas,narrow the regional gap,improve living condition of farmers in mountain areas,and increase income level of farmers in mountain areas.

  19. IEA Bioenergy Task 40Sustainable International Bioenergy Trade:Securing Supply and Demand Country Report 2014—United States

    Energy Technology Data Exchange (ETDEWEB)

    Hess, J. Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lamers, Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Roni, Mohammad S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jacobson, Jacob J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Heath, Brendi [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-01-01

    Logistical barrier are tied to feedstock harvesting, collection, storage and distribution. Current crop harvesting machinery is unable to selectively harvest preferred components of cellulosic biomass while maintaining acceptable levels of soil carbon and minimizing erosion. Actively managing biomass variability imposes additional functional requirements on biomass harvesting equipment. A physiological variation in biomass arises from differences in genetics, degree of crop maturity, geographical location, climatic events, and harvest methods. This variability presents significant cost and performance risks for bioenergy systems. Currently, processing standards and specifications for cellulosic feedstocks are not as well-developed as for mature commodities. Biomass that is stored with high moisture content or exposed to moisture during storage is susceptible to spoilage, rotting, spontaneous combustion, and odor problems. Appropriate storage methods and strategies are needed to better define storage requirements to preserve the volume and quality of harvested biomass over time and maintain its conversion yield. Raw herbaceous biomass is costly to collect, handle, and transport because of its low density and fibrous nature. Existing conventional, bale-based handling equipment and facilities cannot cost-effectively deliver and store high volumes of biomass, even with improved handling techniques. Current handling and transportation systems designed for moving woodchips can be inefficient for bioenergy processes due to the costs and challenges of transporting, storing, and drying high-moisture biomass. The infrastructure for feedstock logistics has not been defined for the potential variety of locations, climates, feedstocks, storage methods, processing alternatives, etc., which will occur at a national scale. When setting up biomass fuel supply chains, for large-scale biomass systems, logistics are a pivotal part in the system. Various studies have shown that long

  20. Sectoral Vulnerabilities to Changing Water Resources: Current and Future Tradeoffs between Supply and Demand in the Conterminous U.S

    Science.gov (United States)

    Meldrum, J.; Averyt, K.; Caldwell, P.; Sun, G.; Huber-lee, A. T.; McNulty, S.

    2012-12-01

    Assessing the sustainability of human activities depends, in part, on the availability of water supplies to meet the demands of those activities. Thermoelectric cooling, agriculture, and municipal uses all compete for water supplies, but each sector differs in its characteristic ratio of water consumption versus withdrawals. This creates different implications for contributing to water supply stress and, conversely, vulnerabilities within each sector to changing water supplies. In this study, we use two measures of water stress, relating to water withdrawals and to water consumption, and calculate the role of each of these three sectors in contributing to the two different measures. We estimate water stress with an enhanced version of the Water Supply Stress Index (WaSSI), calculating the ratio of water demand to water supply at the 8-digit Hydrologic Unit Code (HUC) scale (Sun et al. 2008, 2011; Caldwell et al. 2011). Current water supplies are based on an integrated water balance and flow routing model of the conterminous United States, which accounts for surface water supply, groundwater supply, and major return flows. Future supplies are based on simulated regional changes in streamflow in 2050 from an ensemble of 12 climate models (Milly et al. 2005). We estimate water demands separately for agriculture, municipal uses, and thermoelectric cooling, with the first two based on Kenny et al. (2005) and the last on the approach of Averyt et al. (2011). We find substantial regional variation not only in the overall WaSSI for withdrawals and consumption but also in contribution of the three water use sectors to that total. Results suggest that the relative vulnerabilities of different sectors of human activity to water supply stress vary spatially and that policies for alleviating that stress must consider the specific, regional context of the tradeoffs between competing water demands. Ref's: Averyt, K., Fisher, J., Huber-Lee, A., Lewis, A., Macknick, J., Madden, N

  1. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Yi-Tzu Chang

    2017-06-01

    Full Text Available Subjective visual vertical (SVV judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS. Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs, the present study examined the effect of postural control demands (PDs on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group and 13 age-matched adolescents (control group aged 12–18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion, SVV (accuracy and reaction time, and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1 during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2 the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for

  2. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis.

    Science.gov (United States)

    Chang, Yi-Tzu; Meng, Ling-Fu; Chang, Chun-Ju; Lai, Po-Liang; Lung, Chi-Wen; Chern, Jen-Suh

    2017-01-01

    Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12-18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central

  3. The Impact Of Job Demands And Resources On Job Crafting

    National Research Council Canada - National Science Library

    Sang-Hoon Lee; Yuhyung Shin; Seung Ik Baek

    2017-01-01

    ... grounds for transformation and modification of general roles and specific tasks. Based on the job demands-resources model, our hypotheses are tested using empirical data extracted from 172 subjects currently working in organizations...

  4. Monitoring transcranial direct current stimulation induced changes in cortical excitability during the serial reaction time task.

    Science.gov (United States)

    Ambrus, Géza Gergely; Chaieb, Leila; Stilling, Roman; Rothkegel, Holger; Antal, Andrea; Paulus, Walter

    2016-03-11

    The measurement of the motor evoked potential (MEP) amplitudes using single pulse transcranial magnetic stimulation (TMS) is a common method to observe changes in motor cortical excitability. The level of cortical excitability has been shown to change during motor learning. Conversely, motor learning can be improved by using anodal transcranial direct current stimulation (tDCS). In the present study, we aimed to monitor cortical excitability changes during an implicit motor learning paradigm, a version of the serial reaction time task (SRTT). Responses from the first dorsal interosseous (FDI) and forearm flexor (FLEX) muscles were recorded before, during and after the performance of the SRTT. Online measurements were combined with anodal, cathodal or sham tDCS for the duration of the SRTT. Negative correlations between the amplitude of online FDI MEPs and SRTT reaction times (RTs) were observed across the learning blocks in the cathodal condition (higher average MEP amplitudes associated with lower RTs) but no significant differences in the anodal and sham conditions. tDCS did not have an impact on SRTT performance, as would be predicted based on previous studies. The offline before-after SRTT MEP amplitudes showed an increase after anodal and a tendency to decrease after cathodal stimulation, but these changes were not significant. The combination of different interventions during tDCS might result in reduced efficacy of the stimulation that in future studies need further attention.

  5. Task-driven tube current modulation and regularization design in computed tomography with penalized-likelihood reconstruction

    Science.gov (United States)

    Gang, G. J.; Siewerdsen, J. H.; Stayman, J. W.

    2016-03-01

    Purpose: This work applies task-driven optimization to design CT tube current modulation and directional regularization in penalized-likelihood (PL) reconstruction. The relative performance of modulation schemes commonly adopted for filtered-backprojection (FBP) reconstruction were also evaluated for PL in comparison. Methods: We adopt a task-driven imaging framework that utilizes a patient-specific anatomical model and information of the imaging task to optimize imaging performance in terms of detectability index (d'). This framework leverages a theoretical model based on implicit function theorem and Fourier approximations to predict local spatial resolution and noise characteristics of PL reconstruction as a function of the imaging parameters to be optimized. Tube current modulation was parameterized as a linear combination of Gaussian basis functions, and regularization was based on the design of (directional) pairwise penalty weights for the 8 in-plane neighboring voxels. Detectability was optimized using a covariance matrix adaptation evolutionary strategy algorithm. Task-driven designs were compared to conventional tube current modulation strategies for a Gaussian detection task in an abdomen phantom. Results: The task-driven design yielded the best performance, improving d' by ~20% over an unmodulated acquisition. Contrary to FBP, PL reconstruction using automatic exposure control and modulation based on minimum variance (in FBP) performed worse than the unmodulated case, decreasing d' by 16% and 9%, respectively. Conclusions: This work shows that conventional tube current modulation schemes suitable for FBP can be suboptimal for PL reconstruction. Thus, the proposed task-driven optimization provides additional opportunities for improved imaging performance and dose reduction beyond that achievable with conventional acquisition and reconstruction.

  6. Quantitative work demands, emotional demands, and cognitive stress symptoms in surgery nurses.

    Science.gov (United States)

    Elfering, Achim; Grebner, Simone; Leitner, Monika; Hirschmüller, Anja; Kubosch, Eva Johanna; Baur, Heiner

    2017-06-01

    In surgery, cognitive stress symptoms, including problems in concentrating, deciding, memorising, and reflecting are risks to patient safety. Recent evidence points to social stressors as antecedents of cognitive stress symptoms in surgery personnel. The current study tests whether cognitive stress symptoms are positively associated with emotional abuse, emotional- and task-related demands and resources in surgery work. Forty-eight surgery nurses from two hospitals filled out the Copenhagen Psychosocial Questionnaire in its German version. Task-related and emotional demands were positively related to cognitive stress symptoms. In a stepwise, multiple, linear regression of cognitive stress symptoms on task-related and emotional demands, emotional abuse and emotional demands were unique predictors (p < .05). Efforts to increase patient safety should address emotional abuse, emotional demands, and, therefore, communication and cooperation team climate in surgery personnel.

  7. "Binary" and "non-binary" detection tasks: are current performance measures optimal?

    Science.gov (United States)

    Gur, David; Rockette, Howard E; Bandos, Andriy I

    2007-07-01

    We have observed that a very large fraction of responses for several detection tasks during the performance of observer studies are in the extreme ranges of lower than 11% or higher than 89% regardless of the actual presence or absence of the abnormality in question or its subjectively rated "subtleness." This observation raises questions regarding the validity and appropriateness of using multicategory rating scales for such detection tasks. Monte Carlo simulation of binary and multicategory ratings for these tasks demonstrate that the use of the former (binary) often results in a less biased and more precise summary index and hence may lead to a higher statistical power for determining differences between modalities.

  8. Cognitive load theory and multimedia learning, task characteristics, and learning engagement: The current state of the art

    NARCIS (Netherlands)

    Kirschner, Femke; Kester, Liesbeth; Corbalan, Gemma

    2010-01-01

    Kirschner, F., Kester, L., & Corbalan, G. (2011). Cognitive load theory and multimedia learning, task characteristics, and learner engagement: The current state of the art. Computers in Human Behavior, 27, 1-4. doi:10.1016/j.chb.2010.05.003

  9. Cognitive load theory and multimedia learning, task characteristics, and learning engagement: The current state of the art

    NARCIS (Netherlands)

    Kirschner, Femke; Kester, Liesbeth; Corbalan, Gemma

    2010-01-01

    Kirschner, F., Kester, L., & Corbalan, G. (2011). Cognitive load theory and multimedia learning, task characteristics, and learner engagement: The current state of the art. Computers in Human Behavior, 27, 1-4. doi:10.1016/j.chb.2010.05.003

  10. Transcranial direct current stimulation (tDCS) to the supplementary motor area (SMA) influences performance on motor tasks.

    Science.gov (United States)

    Hupfeld, K E; Ketcham, C J; Schneider, H D

    2017-03-01

    The supplementary motor area (SMA) is believed to be highly involved in the planning and execution of both simple and complex motor tasks. This study aimed to examine the role of the SMA in planning the movements required to complete reaction time, balance, and pegboard tasks using anodal transcranial direct current stimulation (tDCS), which passes a weak electrical current between two electrodes, in order to modulate neuronal activity. Twenty healthy adults were counterbalanced to receive either tDCS (experimental condition) or no tDCS (control condition) for 3 days. During administration of tDCS, participants performed a balance task significantly faster than controls. After tDCS, subjects significantly improved their simple and choice reaction time. These results demonstrate that the SMA is highly involved in planning and executing fine and gross motor skill tasks and that tDCS is an effective modality for increasing SMA-related performance on these tasks. The findings may be generalizable and therefore indicate implications for future interventions using tDCS as a therapeutic tool.

  11. The SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current activities and future key tasks

    Science.gov (United States)

    Beylich, A. A.; Lamoureux, S. F.; Decaulne, A.

    2012-04-01

    geomorphologists, hydrologists, ecologists, permafrost scientists and glaciologists. SEDIBUD has developed manuals and protocols (SEDIFLUX Manual, available online, see below) with a key set of primary surface process monitoring and research data requirements to incorporate results from these diverse projects and allow coordinated quantitative analysis across the programme. Defined SEDIBUD key test sites provide data on annual climate conditions, total discharge and particulate and dissolved fluxes as well as information on other relevant surface processes. A number of selected key test sites is providing high-resolution data on climate conditions, runoff and sedimentary fluxes, which in addition to the annual data contribute to the SEDIBUD metadata database which is currently developed. Comparable datasets from different SEDIBUD key test sites are integrated and analysed to address key research questions as defined in the SEDIBUD Objective (available online, see below). Defined SEDIBUD key tasks for the coming years include (i) The continued generation and compilation of comparable longer-term datasets on contemporary sedimentary fluxes and sediment yields from SEDIBUD key test sites worldwide, (ii) The continued extension of the SEDIBUD metadata database with these datasets, (iii) The testing of defined SEDIBUD hypotheses (available online, see below) by using the datasets continuously compiled in the SEDIBUD metadata database. Detailed information on the I.A.G./A.I.G. SEDIBUD Programme, SEDIBUD meetings, SEDIBUD publications and SEDIBUD online documents and databases is available at the SEDIBUD website under http://www.geomorph.org/wg/wgsb.html.

  12. Current status and future tasks of the Sunshine Project. (Development of new energy technology)

    Energy Technology Data Exchange (ETDEWEB)

    Takada, T.

    1983-01-01

    Since its inception in 1974, the Sunshine Project has involved advances in new energy technology in many areas. The present report covers the principal areas of activity in 1980, examining the development status of solar energy, goethermal energy, coal liquefaction and gasification, hydrogen energy, wind power, ocean thermal energy conversion, etc. Future trends and tasks of new energy technology development are discussed. (In Japanese)

  13. Part-task training in the context of automation: current and future directions.

    Science.gov (United States)

    Gutzwiller, Robert S; Clegg, Benjamin A; Blitch, John G

    2013-01-01

    Automation often elicits a divide-and-conquer outlook. By definition, automation has been suggested to assume control over a part or whole task that was previously performed by a human (Parasuraman & Riley, 1997). When such notions of automation are taken as grounds for training, they readily invoke a part-task training (PTT) approach. This article outlines broad functions of automation as a source of PTT and reviews the PTT literature, focusing on the potential benefits and costs related to using automation as a mechanism for PTT. The article reviews some past work in this area and suggests a path to move beyond the type of work captured by the "automation as PTT" framework. An illustrative experiment shows how automation in training and PTT are actually separable issues. PTT with automation has some utility but ultimately remains an unsatisfactory framework for the future broad potential of automation during training, and we suggest that a new conceptualization is needed.

  14. Task-driven optimization of CT tube current modulation and regularization in model-based iterative reconstruction

    Science.gov (United States)

    Gang, Grace J.; Siewerdsen, Jeffrey H.; Webster Stayman, J.

    2017-06-01

    Tube current modulation (TCM) is routinely adopted on diagnostic CT scanners for dose reduction. Conventional TCM strategies are generally designed for filtered-backprojection (FBP) reconstruction to satisfy simple image quality requirements based on noise. This work investigates TCM designs for model-based iterative reconstruction (MBIR) to achieve optimal imaging performance as determined by a task-based image quality metric. Additionally, regularization is an important aspect of MBIR that is jointly optimized with TCM, and includes both the regularization strength that controls overall smoothness as well as directional weights that permits control of the isotropy/anisotropy of the local noise and resolution properties. Initial investigations focus on a known imaging task at a single location in the image volume. The framework adopts Fourier and analytical approximations for fast estimation of the local noise power spectrum (NPS) and modulation transfer function (MTF)—each carrying dependencies on TCM and regularization. For the single location optimization, the local detectability index (d‧) of the specific task was directly adopted as the objective function. A covariance matrix adaptation evolution strategy (CMA-ES) algorithm was employed to identify the optimal combination of imaging parameters. Evaluations of both conventional and task-driven approaches were performed in an abdomen phantom for a mid-frequency discrimination task in the kidney. Among the conventional strategies, the TCM pattern optimal for FBP using a minimum variance criterion yielded a worse task-based performance compared to an unmodulated strategy when applied to MBIR. Moreover, task-driven TCM designs for MBIR were found to have the opposite behavior from conventional designs for FBP, with greater fluence assigned to the less attenuating views of the abdomen and less fluence to the more attenuating lateral views. Such TCM patterns exaggerate the intrinsic anisotropy of the MTF and NPS

  15. Demand specifying variables and current ventilation rate requirements with respect to the future use of voc sensing for dcv control

    DEFF Research Database (Denmark)

    Kolarik, Jakub

    Demand Controlled Ventilation (DCV) is a well established principle to provide a certain indoor environmental quality, defined both in the terms of air quality and thermal comfort. This is accomplished by adjusting the supplied airflow rate according to a certain demand indicator, which conventio......Demand Controlled Ventilation (DCV) is a well established principle to provide a certain indoor environmental quality, defined both in the terms of air quality and thermal comfort. This is accomplished by adjusting the supplied airflow rate according to a certain demand indicator, which...... conventionally has been the temperature or the CO2-concentration. When compared to schedule driven ventilation, application of DCV can lead to substantial energy savings. However, CO2 is the pollutant related to human occupancy and it does not provide any indication of so called building-related pollution...... be also taken into account in the ventilation control. Recent development in gas sensing technology resulted in a new generation of relatively cheap and practically applicable sensors that can offer measurements of some of the pollutants mentioned above – mainly Volatile Organic Compounds (VOC...

  16. Research Initiatives for Materials State Sensing (RIMSS) Task Order 0020: High Frequency Eddy Current NDE

    Science.gov (United States)

    2014-10-01

    coatings using eddy current techniques”, AIP Conference Proceedings , Vol. 1430, 2012, pp 441. 7. F. M. Smits, “Measurement of sheet resistivities with... Conference 2014: 27 October - 30 October, Charleston, SC, USA. “High-Frequency Eddy Current System for Analyzing Wet Conductive Coatings during...Processing”. 3. QNDE 2014 (ORAL PRESENTATION), 41st Annual Review of Progress in Quantitative Nondestructive Evaluation: Conference Boise Centre

  17. Transcranial direct current stimulation facilitates cognitive multi-task performance differentially depending on anode location and subtask.

    Directory of Open Access Journals (Sweden)

    Melissa eScheldrup

    2014-09-01

    Full Text Available There is a need to facilitate acquisition of real world cognitive multi-tasks that require long periods of training (e.g., air traffic control, intelligence analysis, medicine. Non-invasive brain stimulation – specifically transcranial Direct Current Stimulation (tDCS – has promise as a method to speed multi-task training. We hypothesized that during acquisition of the complex multi-task Space Fortress, subtasks that require focused attention on ship control would benefit from tDCS aimed at the dorsal attention network while subtasks that require redirection of attention would benefit from tDCS aimed at the right hemisphere ventral attention network. We compared effects of 30 min prefrontal and parietal stimulation to right and left hemispheres on subtask performance during the first 45 min of training. The strongest effects both overall and for ship flying (control and velocity subtasks were seen with a right parietal (C4 to left shoulder montage, shown by modeling to induce an electric field that includes nodes in both dorsal and ventral attention networks. This is consistent with the re-orienting hypothesis that the ventral attention network is activated along with the dorsal attention network if a new, task-relevant event occurs while visuospatial attention is focused (Corbetta et al., 2008. No effects were seen with anodes over sites that stimulated only dorsal (C3 or only ventral (F10 attention networks. The speed subtask (update memory for symbols benefited from an F9 anode over left prefrontal cortex. These results argue for development of tDCS as a training aid in real world settings where multi-tasking is critical.

  18. Current and projected water demand and water availability estimates under climate change scenarios in the Weyib River basin in Bale mountainous area of Southeastern Ethiopia

    Science.gov (United States)

    Serur, Abdulkerim Bedewi; Sarma, Arup Kumar

    2017-07-01

    This study intended to estimate the spatial and temporal variation of current and projected water demand and water availability under climate change scenarios in Weyib River basin, Bale mountainous area of Southeastern Ethiopia. Future downscaled climate variables from three Earth System Models under the three RCP emission scenarios were inputted into ArcSWAT hydrological model to simulate different components of water resources of a basin whereas current and projected human and livestock population of the basin is considered to estimate the total annual water demand for various purposes. Results revealed that the current total annual water demand of the basin is found to be about 289 Mm3, and this has to increase by 83.47% after 15 years, 200.67% after 45 years, and 328.78% after 75 years by the 2020s, 2050s, and 2080s, respectively, from base period water demand mainly due to very rapid increasing population (40.81, 130.80, and 229.12% by the 2020s, 2050s, and 2080s, respectively) and climatic variability. The future average annual total water availability in the basin is observed to be increased by ranging from 15.04 to 21.61, 20.08 to 23.34, and 16.21 to 39.53% by the 2020s, 2050s, and 2080s time slice, respectively, from base period available water resources (2333.39 Mm3). The current water availability per capita per year of the basin is about 3112.23 m3 and tends to decline ranging from 11.78 to 17.49, 46.02 to 47.45, and 57.18 to 64.34% by the 2020s, 2050s, and 2080s, respectively, from base period per capita per year water availability. This indicated that there might be possibility to fall the basin under water stress condition in the long term.

  19. Anodal Transcranial Direct Current Stimulation Does Not Facilitate Dynamic Balance Task Learning in Healthy Old Adults

    OpenAIRE

    Kaminski, Elisabeth; Hoff, Maike; Rjosk, Viola; Steele, Christopher J.; Gundlach, Christopher; Sehm, Bernhard; Villringer, Arno; Ragert, Patrick

    2017-01-01

    Older adults frequently experience a decrease in balance control that leads to increased numbers of falls, injuries and hospitalization. Therefore, evaluating older adults’ ability to maintain balance and examining new approaches to counteract age-related decline in balance control is of great importance for fall prevention and healthy aging. Non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) have been shown to beneficially influence motor behavio...

  20. [Historical development and current demands on medical training, further and advanced training in hygiene and infection prevention].

    Science.gov (United States)

    Exner, M; Kramer, A

    2012-11-01

    New risks in nosocomial infections and the dramatic increase in antibiotic-resistant pathogens in healthcare facilities have pointed to the urgent need for a good education of students and practitioners in the basics of hospital hygiene and infection prevention. On the other hand in the last 10 years a large number of institutes of hygiene in universities were closed with remarkable consequences concerning the decreased education in modern hygiene and public health. A broad historical overview over the last 200 years of teaching hygiene and public health at German universities is given which was integrated into the education of medical students. Nowadays many universities do not teach modern hygiene and public health. The demand of re-establishing new institutes of hygiene by the German Medical Council is discussed. The curriculum for the formation of hospital hygienists is presented.

  1. Current state of ESCO activities in Asia: ESCO industry development programs and future tasks in Asian countries

    Energy Technology Data Exchange (ETDEWEB)

    Murakoshi, Chiharu; Nakagami, Hidetoshi (Jyukankyo Research Inst. (Japan))

    2009-07-01

    In Japan and other Asian countries, ESCO markets are under formation. Introduction of ESCOs to Asia took place in the 1990s. A vigorous ESCO market is already forming in Japan, South Korea, China, and Thailand. Also, in Malaysia, and the Philippines, ESCO market development is proceeding. How did these countries introduce ESCO industries? What kind of activities are being carried out, and what are future tasks? As a first step in implementing ESCO development programs, developed countries have used government support, while emerging countries have co-operated with international organisations. By classifying the types of programs and examining activities currently under way, we can understand necessary conditions for developing an ESCO industry. When we classify programs of various countries, we see that most countries implement the same kinds of measures. However, the results vary. Some countries are progressing with market development, while others have not reached the point of market formation. Analysis of factors leading to these variations is important to the future development of ESCO industries. In this paper, we describe the current state of ESCO activities in Japan and emerging countries, and we examine ESCO development programs of each country. In particular, by comparing measures taken in countries with successful ESCO market development, such as Japan, China, Thailand and India with those still trying to develop ESCO markets, such as Malaysia, and the Philippines, we analyse factors leading to success, and we illuminate future tasks for each country.

  2. Searching for strategies to reduce the mechanical demands of the sit-to-stand task with a muscle-actuated optimal control model.

    Science.gov (United States)

    Bobbert, Maarten F; Kistemaker, Dinant A; Vaz, Marco Aurélio; Ackermann, Marko

    2016-08-01

    The sit-to-stand task, which involves rising unassisted from sitting on a chair to standing, is important in daily life. Many people with muscle weakness, reduced range of motion or loading-related pain in a particular joint have difficulty performing the task. How should a person suffering from such impairment best perform the sit-to-stand task and, in the case of pain in a particular joint, with reduced loading of that joint? We developed a musculoskeletal model with reference parameter values based on properties of healthy strong subjects. The model's muscle stimulation-time input was optimized using direct collocation to find strategies that yielded successful sit-to-stand task performance with minimum 'control effort' for the reference set and modified sets of parameter values, and with constraints on tibiofemoral compression force. The sit-to-stand task could be performed successfully and realistically by the reference model, by a model with isometric knee extensor forces reduced to 40% of reference, by a model with isometric forces of all muscles reduced to 45% of reference, and by the reference model with the tibiofemoral compression force constrained during optimization to 65% of the peak value in the reference condition. The strategies found by the model in conditions other than reference could be interpreted well on the basis of cost function and task biomechanics. The question remains whether it is feasible to teach patients with musculoskeletal impairments or joint pain to perform the sit-to-stand task according to strategies that are optimal according to the simulation model. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Current Market Demand for Core Competencies of Librarianship—A Text Mining Study of American Library Association’s Advertisements from 2009 through 2014

    Directory of Open Access Journals (Sweden)

    Qinghong Yang

    2016-02-01

    Full Text Available As librarianship evolves, it is important to examine the changes that have taken place in professional requirements. To provide an understanding of the current market demand for core competencies of librarianship, this article conducts a semi-automatic methodology to analyze job advertisements (ads posted on the American Library Association (ALA Joblist from 2009 through 2014. There is evidence that the ability to solve unexpected complex problems and to provide superior customer service gained increasing importance for librarians during those years. The authors contend that the findings in this report question the status quo of core competencies of librarianship in the US job market.

  4. Analysis on the Current Situation of Farmers' Credit Demand in Gansu Province%甘肃省农户信贷需求现状分析

    Institute of Scientific and Technical Information of China (English)

    何亚玲

    2009-01-01

    The current situation of farmers' credit demand in rural areas of Gansu Province was studied by the method of interview and investigation. And some related policy proposals were put forward according to the economic development of rural areas in Gansu Province.%通过访谈、调查的形式对甘肃省农村地区农户信贷需求现状进行了考察,并针对甘肃农村经济发展的形势,提出了相关政策建议.

  5. 浅析智能电网下的电力需求侧管理%Analysis of Demand Side Management Tasks in Smart Power Grid

    Institute of Scientific and Technical Information of China (English)

    曹京津; 秦立军

    2014-01-01

    Demand Side Management (DSM) will be one of the most important parts of future smart power grid. The DSM algorithms help consumers to be more active contributors in the power system in order to achieve system objectives by scheduling their shift able load. This paper first introduced the smart grid, then introduces the new change of demand side management under the smart grid, finally discuss the new challenges which DSM may face under the smart grid by dividing it into four important parts.%需求侧管理(Demand Side Management, DSM)是未来智能电网中最重要的一个部分。 DSM算法帮助消费者成为电力系统更积极的贡献者,通过可移动的负载来达到系统调度的目的。文章首先介绍了智能电网,接着概括了智能电网下DSM的新变化,最后通过将DSM分为4个重要部分来探讨了智能电网下它所面临的新的挑战。

  6. Effects of transcranial direct current stimulation (tDCS) on multiscale complexity of dual-task postural control in older adults

    Science.gov (United States)

    Zhou, Diange; Zhou, Junhong; Chen, Hu; Manor, Brad; Lin, Jianhao; Zhang, Jue

    2016-01-01

    Transcranial direct current stimulation (tDCS) targeting the prefrontal cortex reduces the size and speed of standing postural sway in younger adults, particularly when performing a cognitive dual task. Here, we hypothesized that tDCS would alter the complex dynamics of postural sway as quantified by multiscale entropy (MSE). Twenty healthy older adults completed two study visits. Center-of-pressure (COP) fluctuations were recorded during single-task (i.e., quiet standing) and dual-task (i.e., standing while performing serial subtractions) conditions, both before and after a 20-min session of real or sham tDCS. MSE was used to estimate COP complexity within each condition. The percentage change in complexity from single- to dual-task conditions (i.e., dual-task cost) was also calculated. Before tDCS, COP complexity was lower (p = 0.04) in the dual-task condition as compared to the single-task condition. Neither real nor sham tDCS altered complexity in the single-task condition. As compared to sham tDCS, real tDCS increased complexity in the dual-task condition (p = 0.02) and induced a trend toward improved serial subtraction performance (p = 0.09). Moreover, those subjects with lower dual-task COP complexity at baseline exhibited greater percentage increases in complexity following real tDCS (R = −0.39, p = 0.05). Real tDCS also reduced the dual-task cost to complexity (p = 0.02), while sham stimulation had no effect. A single session of tDCS targeting the prefrontal cortex increased standing postural sway complexity with concurrent non-postural cognitive task. This form of noninvasive brain stimulation may be a safe strategy to acutely improve postural control by enhancing the system's capacity to adapt to stressors. PMID:25963755

  7. Job task characteristics of Australian emergency services volunteers during search and rescue operations.

    Science.gov (United States)

    Silk, Aaron; Lenton, Gavin; Savage, Robbie; Aisbett, Brad

    2017-07-28

    Search and rescue operations are necessary in locating, assisting and recovering individuals lost or in distress. In Australia, land-based search and rescue roles require a range of physically demanding tasks undertaken in dynamic and challenging environments. The aim of the current research was to identify and characterise the physically demanding tasks inherent to search and rescue operation personnel within Australia. These aims were met through a subjective job task analysis approach. In total, 11 criterion tasks were identified by personnel. These tasks were the most physically demanding, frequently occurring and operationally important tasks to these specialist roles. Muscular strength was the dominant fitness component for 7 of the 11 tasks. In addition to the discrete criterion tasks, an operational scenario was established. With the tasks and operational scenario identified, objective task analysis procedures can be undertaken so that practitioners can implement evidence-based strategies, such as physical selection procedures and task-based physical training programs, commensurate with the physical demands of search and rescue job roles. Practitioner Summary: The identification of physically demanding tasks amongst specialist emergency service roles predicates health and safety strategies which can be incorporated into organisations. Knowledge of physical task parameters allows employers to mitigate injury risk through the implementation of strategies modelled on the precise physical demands of the role.

  8. Energy Demand

    NARCIS (Netherlands)

    Stehfest, E. et al.

    2014-01-01

    Key policy issues – How will energy demand evolve particularly in emerging and medium- and low- income economies? – What is the mix of end-use energy carriers to meet future energy demand? – How can energy efficiency contribute to reducing the growth rate of energy demand and mitigate pressures on t

  9. The risk-benefit task of research ethics committees: An evaluation of current approaches and the need to incorporate decision studies methods

    Directory of Open Access Journals (Sweden)

    Bernabe Rosemarie D L C

    2012-04-01

    Full Text Available Abstract Background Research ethics committees (RECs are tasked to assess the risks and the benefits of a trial. Currently, two procedure-level approaches are predominant, the Net Risk Test and the Component Analysis. Discussion By looking at decision studies, we see that both procedure-level approaches conflate the various risk-benefit tasks, i.e., risk-benefit assessment, risk-benefit evaluation, risk treatment, and decision making. This conflation makes the RECs’ risk-benefit task confusing, if not impossible. We further realize that RECs are not meant to do all the risk-benefit tasks; instead, RECs are meant to evaluate risks and benefits, appraise risk treatment suggestions, and make the final decision. Conclusion As such, research ethics would benefit from looking beyond the procedure-level approaches and allowing disciplines like decision studies to be involved in the discourse on RECs’ risk-benefit task.

  10. On Demand, Development and Dependence: A Review of Current and Future Implications of Socioeconomic Changes for Integrated Water Resource Management in the Okavango Catchment of Southern Africa

    Directory of Open Access Journals (Sweden)

    Thomas Weinzierl

    2013-02-01

    Full Text Available Water is both a key and limited resource in the Okavango Catchment of Southern Africa. It is vital for the ecosystem and the three riparian states Angola, Botswana and Namibia who use the water of the catchment for multiple purposes including pastoralism, farming and tourism. Socioeconomic changes, primarily strong population growth and increasing development demands pose significant challenges for the Okavango Catchment and its Integrated Water Resource Management (IWRM. In this paper, we first review the socioeconomic background and the current and projected water situation. Against this background, we analyze the dependence of the riparian states and the local livelihoods on the Okavango Catchment. Third, we discuss the implications of socioeconomic changes and increased water demand for the IWRM in the catchment. We review the scientific literature and relevant reports. Further we utilize (geo-spatial analysis of socioeconomic, livelihood and hydrological data, supplemented by a field visit to Namibia and Botswana. Our findings suggest that strong population growth and the stabilization of Angola are likely to increase the pressure to develop the region along the Okavango. The central challenge for IWRM is hence to enable Angola to meet its development needs without limiting livelihood and economic prospects in Botswana and Namibia.

  11. 面向云制造的按需工作流任务分配方法%On-Demand Task Assignment Strategies for Workflow-Based Applications in Cloud Manufacturing

    Institute of Scientific and Technical Information of China (English)

    王明微; 周竞涛; 敬石开

    2012-01-01

    复杂大型的云制造应用需要通过既相互独立又能进行相互配合的多个制造云来协同完成,导致同一个工作流中的任务可在多个分布的工作流引擎中完成.为此,提出了一种“按需分配”的工作流任务分配方法,将任务分配贯穿于业务过程模型实例化过程,详细分析了云制造环境下影响任务分配的4种主要因素;为提高任务分配过程的自动化程度,给出了每种因素与任务需求的匹配方法.仿真实验结果表明了该方法的有效性.%Large and complex cloud manufacturing applications relies on co-operation between self-governed manufacturing clouds. Since each manufacturing cloud has its own capacity, the tasks defined in the workflow are allocated to distributed clouds to achieve a predetermined goal. In this paper, a study on on-demand task assignment strategy for workflow-based cloud manufacturing applications is presented, which aims to build a flexible workflow implementation mechanism . The proposed strategy assigns the tasks through the process of business process model instantiation. Four important influencing factors during task assigning process and their measuring methods are given in detail. To raise the degree of automation in assigning, matching methods between task requirements and the workflow engine are given for each factor. Simulation experiments validate the effectiveness of the proposed method.

  12. Development of a “Current Energy Mix Scenario” and a “Electricity as Main Energy Source Scenario” for electricity demand up to 2100

    Directory of Open Access Journals (Sweden)

    Mário J. S. Brito

    2014-06-01

    Full Text Available In this work, we develop a model to forecast world electricity production up to 2100. We analyze historical data for electricity production, population and GDP per Capita for the period 1900–2008. We show that electricity production follows general trends. First, there is an electricity intensity target of 0.20-0.25 kWh per unit of GDP (US$2012 as economies mature, except in countries traditionally relying heavily on renewable electricity (hydroelectricity, for whom this target ranges between 0.50 to 0.80 kWh per unit GDP. Also, countries that belong to the same region tend to follow the evolution of electricity production and GDP/Capita of a regional “modelcountry”. Equations that describe the behavior of these model countries are used to forecast electricity production per capita up to 2100 under a low and a high scenario for the evolution of GDP per Capita. For electricity production two main scenarios were set: “Current Energy MixScenario” and “Electricity as Main Energy Source Scenario”, with two additional sub scenarios considering slightly different electric intensities. Forecasts up to 2100 yield a demand forelectricity production 3.5 to 5 times higher than the current production for the “Current EnergyMix Scenario” and about 9 to 14 times for the “Electricity as Main Energy Source Scenario”. Forecasts for the “Current Energy Mix Scenario” matched well with forecasts from IEA/EIA (International Energy Agency/ Energy Information Administration while the forecasts for the“Electricity as the Main Energy Source Scenario” are much higher than current predictions.

  13. On What Ground Do We Mentalize? Characteristics of Current Tasks and Sources of Information that Contribute to Mentalizing Judgments

    Science.gov (United States)

    Achim, Amelie M.; Guitton, Matthieu; Jackson, Philip L.; Boutin, Andree; Monetta, Laura

    2013-01-01

    Mentalizing is an aspect of social cognition that is garnering increased interest. Although a wide variety of experimental tasks are available to measure mentalizing abilities in adults, the most widely used tasks typically focus on specific aspects of mentalizing, and mentalizing judgments are performed based on a limited set of information about…

  14. On What Ground Do We Mentalize? Characteristics of Current Tasks and Sources of Information that Contribute to Mentalizing Judgments

    Science.gov (United States)

    Achim, Amelie M.; Guitton, Matthieu; Jackson, Philip L.; Boutin, Andree; Monetta, Laura

    2013-01-01

    Mentalizing is an aspect of social cognition that is garnering increased interest. Although a wide variety of experimental tasks are available to measure mentalizing abilities in adults, the most widely used tasks typically focus on specific aspects of mentalizing, and mentalizing judgments are performed based on a limited set of information about…

  15. International Energy Agency (IEA) Task 40 — Sustainable International Energy Trade: Securing Supply and Demand -- Country Report 2010 for the United States

    Energy Technology Data Exchange (ETDEWEB)

    J. Richard Hess; Jacob J. Jacobson; Richard Nelson; Carl Wolf

    2011-12-01

    This report updates the status of U.S. biomass resources currently and future potentials for domestic and export markets of residues, energy crops, and woody resources. Includes energy and fuel production and consumption statistics, driving policies, targets, and government investment in bioenergy industry development.

  16. International Energy Agency (IEA) Task 40 — Sustainable International Energy Trade: Securing Supply and Demand -- Country Report 2009 for the United States

    Energy Technology Data Exchange (ETDEWEB)

    J. Richard Hess; Jacob J. Jacobson; Richard Nelson; Carl Wolf

    2009-06-01

    This report outlines the status of U.S. biomass resources currently and future potentials for domestic and export markets of residues, energy crops, and woody resources. Includes energy and fuel production and consumption statistics, driving policies, targets, and government investment in bioenergy industry development.

  17. [Basic health care in developing countries--realization of a desirable dream of the government--demands and tasks of German physicians].

    Science.gov (United States)

    Windorfer, A; Schulz, W

    1986-02-01

    In most newly independent African countries, medical care imitates the Western model, with large urban hospitals containing much of the health care personnel and equipment. A decline in the availability of funds for training and facilities, and the appearance of new diseases provoked by industrialization led to the decline of both the quality and the quantity of medical care, especially in rural areas. In the 1970s, a number of African nations developed a network of ambulatory health facilities and village health workers, thus instituting a Primary Health Care System (PHC-System). Due to logistical and supervisory problems, however, these networks often disintegrated after foreign professionals and administrators departed. They are, nevertheless, prerequisites for the gradual improvement of the health care of rural populations in developing countries. Two basic requirements for their establishment and development are a relatively large personnel and financial investment, and the continuous counselling and supervision of trained nonprofessionals. The tasks which these health workers learn and eventually perform over a 1-2 year period include preventive medicine, counselling patients, providing medicines, reporting to responsible clinics, family planning, child care, and the treatment of a variety of diseases. Preventive measures in the framework of PHC Systems encompass 2 principle areas of hygiene, i.e., provision of clean drinking water and proper disposal of human and other wastes; and innoculations. Providing family planning information is a principle duty of the village health workers. To satisfy minimal rural health care and prevention requirements, regional medical centers serving an area of radius 100 to 150 km are needed to train the village health workers, provide basic medicines, and supply medicine and professional medical supervision to the ambulatory centers.

  18. From 'D' to 'I': A critique of the current United States preventive services task force recommendation for testicular cancer screening.

    Science.gov (United States)

    Rovito, Michael J; Manjelievskaia, Janna; Leone, James E; Lutz, Michael J; Nangia, Ajay

    2016-06-01

    In 2004, the United States Preventive Services Task Force (USPSTF) gave testicular cancer (TCa) screening a 'D' recommendation, discouraging the use of this preventive service. The USPSTF suggested that screening, inclusive of testicular self-examination (TSE) and clinician examination, does not reduce TCa mortality rates and that the high risk of false positives could serve as a detriment to patient quality of life. Others suggests that TCa screening is ineffective at detecting early-stage cases of TCa and readily highlights a lack of empirical evidence demonstrating said efficacy. These assertions, however, stand in stark contrast to the widely held support of TCa screening among practicing public health professionals, advocacy groups, and clinicians. In this present study, a review was conducted of the methods and processes used by the USPSTF in their 2011 reaffirmation of the 'D' grade recommendation. The evidence base and commentary offered as to why TSE, as part of the overall recommendation for TCa screening, was given a 'D' grade were analyzed for logical reasoning and methodological rigor. Considering the methodological flaws and the veritable lack of evidence needed to grant a conclusive recommendation, the question is raised if the current 'D' grade for TCa screening (i.e. discourage the use of said service) should be changed to an 'I' statement (i.e. the balance of benefits and harms is indeterminate). Therefore the purpose of this paper is to present the evidence of TCa screening in the context of efficacy and prevention in order for the field to reassess its relative value.

  19. Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

    Directory of Open Access Journals (Sweden)

    Bettina eGathmann

    2015-02-01

    Full Text Available Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring - an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task. This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST and the newly developed Balanced Switching Task (BST, measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task.

  20. Demand Uncertainty

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen

    This paper presents a model of trade that explains why firms wait to export and why many exporters fail. Firms face uncertain demands that are only realized after the firm enters the destination. The model retools the timing of uncertainty resolution found in productivity heterogeneity models...... in untested destinations. The option to forecast demands causes firms to delay exporting in order to gather more information about foreign demand. Third, since uncertainty is resolved after entry, many firms enter a destination and then exit after learning that they cannot profit. This prediction reconciles...

  1. Demand forecasting

    OpenAIRE

    Gregor, Belčec

    2011-01-01

    Companies operate in an increasingly challenging environment that requires them to continuously improve all areas of the business process. Demand forecasting is one area in manufacturing companies where we can hope to gain great advantages. Improvements in forecasting can result in cost savings throughout the supply chain, improve the reliability of information and the quality of the service for our customers. In the company Danfoss Trata, d. o. o. we did not have a system for demand forecast...

  2. The current California drought through EDDI's eyes: early warning and monitoring of agricultural and hydrologic drought with the new Evaporative Demand Drought Index.

    Science.gov (United States)

    Hobbins, M.; McEvoy, D.; Huntington, J. L.; Wood, A. W.; Morton, C.; Verdin, J. P.

    2015-12-01

    We have developed a physically based, multi-scalar drought index—the Evaporative Demand Drought Index (EDDI)—to improve treatment of evaporative dynamics in drought monitoring. Existing popular drought indices—such as the Palmer Drought Severity Index that informs much of the US Drought Monitor (USDM)—have primarily relyied on precipitation and temperature (T) to represent hydroclimatic anomalies, leaving evaporative demand (E0) most often derived from poorly performing T-based parameterizations then used to derive actual evapotranspiration (ET) from LSMs. Instead, EDDI leverages the inter-relations of E0 and ET, measuring E0's physical response to surface drying anomalies due to two distinct land surface/atmosphere interactions: (i) in sustained drought, limited moisture availability forces E0 and ET into a complementary relation, whereby ET declines as E0 increases; and (ii) in "flash" droughts, E0 increases due to increasing advection or radiation. E0's rise in response to both drought types suggests EDDI's robustness as a monitor and leading indicator of drought. To drive EDDI, we use for E0 daily reference ET from the ASCE Standardized Reference ET equation forced by North American Land Data Assimilation System drivers. EDDI is derived by aggregating E0 anomalies from its long-term mean across a period of interest and normalizing them to a Z-score. Positive EDDI indicates drier than normal conditions (and so drought). We use the current historic California drought as a test-case in which to examine EDDI's performance in monitoring agricultural and hydrologic drought. We observe drought development and decompose the behavior of drought's evaporative drivers during in-drought intensification periods and wetting events. EDDI's performance as a drought leading indicator with respect to the USDM is tested in important agricultural regions. Comparing streamflow from several USGS gauges in the Sierra Nevada to EDDI, we find that EDDI tracks most major

  3. Improving access to emergency contraception pills through strengthening service delivery and demand generation: a systematic review of current evidence in low and middle-income countries.

    Directory of Open Access Journals (Sweden)

    Angela Dawson

    Full Text Available Emergency contraception pills (ECP are among the 13 essential commodities in the framework for action established by the UN Commission on Life-Saving Commodities for Women and Children. Despite having been on the market for nearly 20 years, a number of barriers still limit women's access to ECP in low- and middle-income countries (LMIC including limited consumer knowledge and poor availability. This paper reports the results of a review to synthesise the current evidence on service delivery strategies to improve access to ECP.A narrative synthesis methodology was used to examine peer reviewed research literature (2003 to 2013 from diverse methodological traditions to provide critical insights into strategies to improve access from a service delivery perspective. The studies were appraised using established scoring systems and the findings of included papers thematically analysed and patterns mapped across all findings using concept mapping.Ten papers were included in the review. Despite limited research of adequate quality, promising strategies to improve access were identified including: advance provision of ECP; task shifting and sharing; intersectoral collaboration for sexual assault; m-health for information provision; and scale up through national family planning programs.There are a number of gaps in the research concerning service delivery and ECP in LMIC. These include a lack of knowledge concerning private/commercial sector contributions to improving access, the needs of vulnerable groups of women, approaches to enhancing intersectoral collaboration, evidence for social marketing models and investment cases for ECP.

  4. Task demands and limb apraxia in stroke.

    Science.gov (United States)

    Roy, E A; Heath, M; Westwood, D; Schweizer, T A; Dixon, M J; Black, S E; Kalbfleisch, L; Barbour, K; Square, P A

    2000-11-01

    The present study was designed to examine the frequency and severity of apraxia in patients with left- or right-hemisphere stroke in both pantomime and imitation conditions and to compare the frequency of apraxia in each stroke group across the three patterns of apraxia described in Roy's model (Roy, 1996). Ninety-nine stroke patients and 15 age-matched healthy adults performed eight transitive gestures to pantomime and to imitation. Gestural performance was quantified as accuracy on five performance dimensions; a composite score, an arithmetic combination of the five performance dimensions, was used as an index of the overall accuracy. Analyses revealed a comparable proportion of patients in each stroke group were classified as apraxic in the imitation condition, but a higher proportion of left stroke patients were apraxic in the pantomime condition. The severity of apraxia in each stroke group and the performance dimensions affected were, however, comparable. Analyses of the patterns of apraxia (pantomime alone, imitation alone or apraxia in both conditions) revealed a higher frequency of apraxia in both stroke groups for the pattern reflecting apraxia in both conditions, indicating that a disruption at the movement execution stage of gesture performance was most common. Copyright 2000 Academic Press.

  5. Pilot Task Demand Load During RNAV Approaches

    NARCIS (Netherlands)

    Heiligers, M.M.

    2011-01-01

    The question that started this research was: “Why is approach A more difficult to fly for a pilot than approach B?”. To find an answer to this question, pilots flew a large variety of Area Navigation (RNAV) approaches during several flight simulator and real flight experiments. The results of these

  6. Routization Problem Complicated by the Dependence of Costs Functions and «Current» Restrictions From the Tasks List

    Directory of Open Access Journals (Sweden)

    A. G Chentsov

    2016-01-01

    Full Text Available The problem of a routization of the movements complicated by the restrictions of different type (preceding conditions, the restrictions on the attainability of states by each movement and others is considered. A multivariance at the movement step is permitted, it is naturally resulted in the problem about the visiting of megalopolises. The costs of movements and jobs executed when visiting megalopolises may depend on the list of tacks. This list may correspond to performed or unperformed tasks. ”Current” restrictions (on movements may depend on the aforementioned list of tasks. The considered setting is oriented to the application with regard to a nuclear power engineering problems (the problem of decreasing irradiation of the nuclear power station staff when executing a complex of tasks under high radiation intensity and the machine building. In the second case, which consists in controling a machine for the sheet cutting of details by the numerical program control machines, ”current” restrictions on movements may be conditioned by temperature tolerance relative to the fragments of sheet which have already been ”visited” by the cutting machine. The scheme of constructing the optimal solution based on the widely understood dynamic programming is considered in this article. The used algorithm is realized on a personal computer; the results of its application are illustrated by the modelling examples.

  7. Nutrient uplift in a cyclonic eddy increases diversity, primary productivity and iron demand of microbial communities relative to a western boundary current

    Directory of Open Access Journals (Sweden)

    Martina A. Doblin

    2016-04-01

    Full Text Available The intensification of western boundary currents in the global ocean will potentially influence meso-scale eddy generation, and redistribute microbes and their associated ecological and biogeochemical functions. To understand eddy-induced changes in microbial community composition as well as how they control growth, we targeted the East Australian Current (EAC region to sample microbes in a cyclonic (cold-core eddy (CCE and the adjacent EAC. Phototrophic and diazotrophic microbes were more diverse (2–10 times greater Shannon index in the CCE relative to the EAC, and the cell size distribution in the CCE was dominated (67% by larger micro-plankton $(\\geq 20\\lrm{\\mu }\\mathrm{m}$ ≥ 20 μ m , as opposed to pico- and nano-sized cells in the EAC. Nutrient addition experiments determined that nitrogen was the principal nutrient limiting growth in the EAC, while iron was a secondary limiting nutrient in the CCE. Among the diazotrophic community, heterotrophic NifH gene sequences dominated in the EAC and were attributable to members of the gamma-, beta-, and delta-proteobacteria, while the CCE contained both phototrophic and heterotrophic diazotrophs, including Trichodesmium, UCYN-A and gamma-proteobacteria. Daily sampling of incubation bottles following nutrient amendment captured a cascade of effects at the cellular, population and community level, indicating taxon-specific differences in the speed of response of microbes to nutrient supply. Nitrogen addition to the CCE community increased picoeukaryote chlorophyll a quotas within 24 h, suggesting that nutrient uplift by eddies causes a ‘greening’ effect as well as an increase in phytoplankton biomass. After three days in both the EAC and CCE, diatoms increased in abundance with macronutrient (N, P, Si and iron amendment, whereas haptophytes and phototrophic dinoflagellates declined. Our results indicate that cyclonic eddies increase delivery of nitrogen to the upper ocean to potentially

  8. Nutrient uplift in a cyclonic eddy increases diversity, primary productivity and iron demand of microbial communities relative to a western boundary current.

    Science.gov (United States)

    Doblin, Martina A; Petrou, Katherina; Sinutok, Sutinee; Seymour, Justin R; Messer, Lauren F; Brown, Mark V; Norman, Louiza; Everett, Jason D; McInnes, Allison S; Ralph, Peter J; Thompson, Peter A; Hassler, Christel S

    2016-01-01

    The intensification of western boundary currents in the global ocean will potentially influence meso-scale eddy generation, and redistribute microbes and their associated ecological and biogeochemical functions. To understand eddy-induced changes in microbial community composition as well as how they control growth, we targeted the East Australian Current (EAC) region to sample microbes in a cyclonic (cold-core) eddy (CCE) and the adjacent EAC. Phototrophic and diazotrophic microbes were more diverse (2-10 times greater Shannon index) in the CCE relative to the EAC, and the cell size distribution in the CCE was dominated (67%) by larger micro-plankton [Formula: see text], as opposed to pico- and nano-sized cells in the EAC. Nutrient addition experiments determined that nitrogen was the principal nutrient limiting growth in the EAC, while iron was a secondary limiting nutrient in the CCE. Among the diazotrophic community, heterotrophic NifH gene sequences dominated in the EAC and were attributable to members of the gamma-, beta-, and delta-proteobacteria, while the CCE contained both phototrophic and heterotrophic diazotrophs, including Trichodesmium, UCYN-A and gamma-proteobacteria. Daily sampling of incubation bottles following nutrient amendment captured a cascade of effects at the cellular, population and community level, indicating taxon-specific differences in the speed of response of microbes to nutrient supply. Nitrogen addition to the CCE community increased picoeukaryote chlorophyll a quotas within 24 h, suggesting that nutrient uplift by eddies causes a 'greening' effect as well as an increase in phytoplankton biomass. After three days in both the EAC and CCE, diatoms increased in abundance with macronutrient (N, P, Si) and iron amendment, whereas haptophytes and phototrophic dinoflagellates declined. Our results indicate that cyclonic eddies increase delivery of nitrogen to the upper ocean to potentially mitigate the negative consequences of increased

  9. Demanding Satisfaction

    Science.gov (United States)

    Oguntoyinbo, Lekan

    2010-01-01

    It was the kind of crisis most universities dread. In November 2006, a group of minority student leaders at Indiana University-Purdue University Indianapolis (IUPUI) threatened to sue the university if administrators did not heed demands that included providing more funding for multicultural student groups. This article discusses how this threat…

  10. Functional interaction between right parietal and bilateral frontal cortices during visual search tasks revealed using functional magnetic imaging and transcranial direct current stimulation.

    Directory of Open Access Journals (Sweden)

    Amanda Ellison

    Full Text Available The existence of a network of brain regions which are activated when one undertakes a difficult visual search task is well established. Two primary nodes on this network are right posterior parietal cortex (rPPC and right frontal eye fields. Both have been shown to be involved in the orientation of attention, but the contingency that the activity of one of these areas has on the other is less clear. We sought to investigate this question by using transcranial direct current stimulation (tDCS to selectively decrease activity in rPPC and then asking participants to perform a visual search task whilst undergoing functional magnetic resonance imaging. Comparison with a condition in which sham tDCS was applied revealed that cathodal tDCS over rPPC causes a selective bilateral decrease in frontal activity when performing a visual search task. This result demonstrates for the first time that premotor regions within the frontal lobe and rPPC are not only necessary to carry out a visual search task, but that they work together to bring about normal function.

  11. Occupational exposure to electric fields and induced currents associated with 400 kV substation tasks from different service platforms.

    Science.gov (United States)

    Korpinen, Leena H; Elovaara, Jarmo A; Kuisti, Harri A

    2011-01-01

    The aim of the study was to investigate the occupational exposure to electric fields, average current densities, and average total contact currents at 400 kV substation tasks from different service platforms (main transformer inspection, maintenance of operating device of disconnector, maintenance of operating device of circuit breaker). The average values are calculated over measured periods (about 2.5 min). In many work tasks, the maximum electric field strengths exceeded the action values proposed in the EU Directive 2004/40/EC, but the average electric fields (0.2-24.5 kV/m) were at least 40% lower than the maximum values. The average current densities were 0.1-2.3 mA/m² and the average total contact currents 2.0-143.2 µA, that is, clearly less than the limit values of the EU Directive. The average values of the currents in head and contact currents were 16-68% lower than the maximum values when we compared the average value from all cases in the same substation. In the future it is important to pay attention to the fact that the action and limit values of the EU Directive differ significantly. It is also important to take into account that generally, the workers' exposure to the electric fields, current densities, and total contact currents are obviously lower if we use the average values from a certain measured time period (e.g., 2.5 min) than in the case where exposure is defined with only the help of the maximum values. © 2010 Wiley-Liss, Inc.

  12. Controlling the stream of thought: working memory capacity predicts adjustment of mind-wandering to situational demands.

    Science.gov (United States)

    Rummel, Jan; Boywitt, C Dennis

    2014-10-01

    Although engaging in task-unrelated thoughts can be enjoyable and functional under certain circumstances, allowing one's mind to wander off-task will come at a cost to performance in many situations. Given that task-unrelated thoughts need to be blocked out when the current task requires full attention, it has been argued that cognitive control is necessary to prevent mind-wandering from becoming maladaptive. Extending this idea, we exposed participants to tasks of different demands and assessed mind-wandering via thought probes. Employing a latent-change model, we found mind-wandering to be adjusted to current task demands. As hypothesized, the degree of adjustment was predicted by working memory capacity, indicating that participants with higher working memory capacity were more flexible in their coordination of on- and off-task thoughts. Notably, the better the adjustment, the smaller performance decrements due to increased task demands were. On the basis of these findings, we argue that cognitive control does not simply allow blocking out task-unrelated thoughts but, rather, allows one to flexibly adjust mind-wandering to situational demands.

  13. Demand Uncertainty

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen

    This paper presents a model of trade that explains why firms wait to export and why many exporters fail. Firms face uncertain demands that are only realized after the firm enters the destination. The model retools the timing of uncertainty resolution found in productivity heterogeneity models...... the high rate of exit seen in the first years of exporting. Finally, when faced with multiple countries in which to export, some firms will choose to sequentially export in order to slowly learn more about its chances for success in untested markets....

  14. Evaluating Virtual Reality and Augmented Reality Training for Industrial Maintenance and Assembly Tasks

    Science.gov (United States)

    Gavish, Nirit; Gutiérrez, Teresa; Webel, Sabine; Rodríguez, Jorge; Peveri, Matteo; Bockholt, Uli; Tecchia, Franco

    2015-01-01

    The current study evaluated the use of virtual reality (VR) and augmented reality (AR) platforms, developed within the scope of the SKILLS Integrated Project, for industrial maintenance and assembly (IMA) tasks training. VR and AR systems are now widely regarded as promising training platforms for complex and highly demanding IMA tasks. However,…

  15. Evaluating Virtual Reality and Augmented Reality Training for Industrial Maintenance and Assembly Tasks

    Science.gov (United States)

    Gavish, Nirit; Gutiérrez, Teresa; Webel, Sabine; Rodríguez, Jorge; Peveri, Matteo; Bockholt, Uli; Tecchia, Franco

    2015-01-01

    The current study evaluated the use of virtual reality (VR) and augmented reality (AR) platforms, developed within the scope of the SKILLS Integrated Project, for industrial maintenance and assembly (IMA) tasks training. VR and AR systems are now widely regarded as promising training platforms for complex and highly demanding IMA tasks. However,…

  16. Initial Development of a Brief Behavioral Economic Assessment of Alcohol Demand.

    Science.gov (United States)

    Owens, Max M; Murphy, Cara M; MacKillop, James

    2015-06-01

    Due to difficulties with definition and measurement, the role of conscious craving in substance use disorders remains contentious. To address this, behavioral economics is increasingly being used to quantify aspects of an individual's acute motivation to use a substance. Doing so typically involves the use of a purchase task, in which participants make choices about consuming alcohol or other substances at various prices and multiple indices of alcohol demand are generated. However, purchase tasks can be limited by the time required to administer and score them. In the current study, a brief 3-item measure, designed to capture three important indices of demand that are derived from demand curve modeling (intensity, Omax, and breakpoint), was investigated in a group of 84 heavy drinkers. Participants underwent a cue-reactivity paradigm that is established to increase both conscious craving and alcohol demand on traditional purchase tasks. All three indices of demand for alcohol measured using the abbreviated measure increased significantly in response to alcohol cues, analogous to what has been observed using a traditional purchase task. Additionally, the correlations between these indices and subjective craving were modest-to-moderate, as has been found in studies comparing craving to the indices derived from purchase tasks. These findings suggest that this abbreviated measure may be a useful and efficient way to capture important and distinct aspects of motivation for alcohol. If these results are confirmed, this measure may be able to help increase the portability of behavioral economic indices of demand into novel research and clinical contexts.

  17. Characteristics of current tasks that contribute to mentalizing judgments: does the engagement of the participants in the social interaction matter? Comment on Achim et al. (2013).

    Science.gov (United States)

    Champagne-Lavau, Maud; Moreau, Noémie

    2013-12-01

    In a recent article, Achim et al. (2013) discussed the different sources of information that contribute to mentalizing judgments in current theory-of-mind (ToM) tasks. The authors rightly emphasized the dynamic aspect of real-life social interaction, suggesting that taking account of the ongoing changes occurring during social interaction would make ToM tasks more ecological. They proposed a framework (i.e., the Eight Sources of Information Framework) that specifies the 8 sources of information we get from the environment and/or from our memories to attribute mental states to others. Nevertheless, we believe that a central aspect of ToM is missing in this framework: the engagement (or not) of the participant in the social interaction during ToM assessment. Indeed, this framework fails to consider how the participant who takes part in the ToM task manages this information, depending on the fact that he or she is involved in the interaction or not and how the information concerning the agent may impact the participant attribution of mental states. We reviewed several arguments and results from the ToM literature suggesting that merely observing a social interaction is not equivalent to participating in an interaction in terms of cognitive processes involved in the attribution of mental states to others.

  18. sLORETA current source density analysis of evoked potentials for spatial updating in a virtual navigation task.

    Science.gov (United States)

    Nguyen, Hai M; Matsumoto, Jumpei; Tran, Anh H; Ono, Taketoshi; Nishijo, Hisao

    2014-01-01

    Previous studies have reported that multiple brain regions are activated during spatial navigation. However, it is unclear whether these activated brain regions are specifically associated with spatial updating or whether some regions are recruited for parallel cognitive processes. The present study aimed to localize current sources of event related potentials (ERPs) associated with spatial updating specifically. In the control phase of the experiment, electroencephalograms (EEGs) were recorded while subjects sequentially traced 10 blue checkpoints on the streets of a virtual town, which were sequentially connected by a green line, by manipulating a joystick. In the test phase of the experiment, the checkpoints and green line were not indicated. Instead, a tone was presented when the subjects entered the reference points where they were then required to trace the 10 invisible spatial reference points corresponding to the checkpoints. The vertex-positive ERPs with latencies of approximately 340 ms from the moment when the subjects entered the unmarked reference points were significantly larger in the test than in the control phases. Current source density analysis of the ERPs by standardized low-resolution brain electromagnetic tomography (sLORETA) indicated activation of brain regions in the test phase that are associated with place and landmark recognition (entorhinal cortex/hippocampus, parahippocampal and retrosplenial cortices, fusiform, and lingual gyri), detecting self-motion (posterior cingulate and posterior insular cortices), motor planning (superior frontal gyrus, including the medial frontal cortex), and regions that process spatial attention (inferior parietal lobule). The present results provide the first identification of the current sources of ERPs associated with spatial updating, and suggest that multiple systems are active in parallel during spatial updating.

  19. sLORETA current source density analysis of evoked potentials for spatial updating in a virtual navigation task

    Directory of Open Access Journals (Sweden)

    Hai Minh Nguyen

    2014-03-01

    Full Text Available Previous studies have reported that multiple brain regions are activated during spatial navigation. However, it is unclear whether these activated brain regions are specifically associated with spatial updating or whether some regions are recruited for parallel cognitive processes. The present study aimed to localize current sources of event related potentials (ERPs associated with spatial updating specifically. In the control phase of the experiment, electroencephalograms (EEGs were recorded while subjects sequentially traced 10 blue checkpoints on the streets of a virtual town, which were sequentially connected by a green line, by manipulating a joystick. In the test phase of the experiment, the checkpoints and green line were not indicated. Instead, a tone was presented when the subjects entered the reference points where they were then required to trace the 10 invisible spatial reference points corresponding to the checkpoints. The vertex-positive ERPs with latencies of approximately 340 ms from the moment when the subjects entered the unmarked reference points were significantly larger in the test than in the control phases. Current source density analysis of the ERPs by sLORETA indicated activation of brain regions in the test phase that are associated with place and landmark recognition (entorhinal cortex/hippocampus, parahippocampal and retrosplenial cortices, fusiform and lingual gyri, detecting self-motion (posterior cingulate and posterior insular cortices, motor planning (superior frontal gyrus, including the medial frontal cortex, and regions that process spatial attention (inferior parietal lobule. The present results provide the first identification of the current sources of ERPs associated with spatial updating, and suggest that multiple systems are active in parallel during spatial updating.

  20. Physical demands in worklife.

    Science.gov (United States)

    Astrand, I

    1988-01-01

    Industrial occupations which are physically strenuous in the traditional sense of the word have decreased in number. They have partly been replaced by "light," repetitive, monotonous work tasks performed in a sitting position. The number of heavy work tasks within the service sector has increased. Specialization has been intensified. The individual's capacity for strenuous work is still of importance to successful work performance. Many studies show that an optional choice of work pace in physically demanding occupational work results in an adaptation of pace or intensity until the worker is utilizing 40-50% of her or his capacity. When the work rate is constrained, the relative strain of the individual varies inversely with the physical work capacity. The frequency of musculoskeletal disorders has concurrently increased with the implementation of industrial mechanization. New, wise, ergonomic moves are needed to stop this development.

  1. Time up and go task performance improves after transcranial direct current stimulation in patient affected by Parkinson's disease.

    Science.gov (United States)

    Manenti, Rosa; Brambilla, Michela; Rosini, Sandra; Orizio, Italo; Ferrari, Clarissa; Borroni, Barbara; Cotelli, Maria

    2014-09-19

    Locomotor disturbances represent one of the major distress in everyday life in people with Parkinson's disease (PD). Timed up and go test (TUG) has been advocated a useful and reliable tool for quantifying locomotor performance. The aim of this study was to assess the effect of anodal transcranial direct current stimulation (tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) during timed up and go test (TUG) in a group of patients with PD. Ten participants underwent two sessions of anodal tDCS (left and right) and one session of placebo tDCS. TUG was performed before and after each tDCS session (anodal or placebo). A significant motor improvement after right DLPFC stimulation vs. placebo stimulation was observed. These results suggest that anodal tDCS can be a relevant tool to modulate walking abilities in PD.

  2. [Was the current surplus of neurosurgeons predictable in 2009? Analysis of the situation based on the Report of supply and demand of medical specialists in Spain (2008-2025)].

    Science.gov (United States)

    Martín-Láez, Rubén; Ibáñez, Javier; Lagares, Alfonso; Fernández-Alén, José; Díez-Lobato, Ramiro

    2012-11-01

    In 2009 the Spanish Ministry of Health (SMH) published the report of supply and demand of medical specialists in Spain (2008-2025), in which our specialty was considered as presenting a moderate deficit of consultants. However, Spanish neurosurgery is currently in a situation of having a surplus of neurosurgeons. To determine whether it was possible to predict the current excess of neurosurgeons in 2009 and to forecast the most likely perspective of supply and demand in 2017. Raw data extracted from the SMH report, information on the ages of the Spanish neurosurgeons obtained from the study performed by our Board of Directors in 2001, and annual mortality rates for different age ranges provided by the National Institute of Statistics, were used to predict the evolution of supply and demand of neurosurgeons for the periods 2008-2012 and 2013-2017. The current situation of an excess of specialists was predictable in 2009, and if appropriate measures are not taken, a surplus of more than 100 neurosurgeons is likely in 2017, with an unemployment rate above 26% in the worst scenario. In order to match the actual and future demand of specialists, it is necessary and urgent to reduce the number of neurosurgical in-training positions. To achieve this goal, it is essential to obtain periodical and up-to-date structural information of the different Neurosurgery Departments and Units, and to revisit the accreditation terms of the more than fifty current teaching units. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  3. Time constraints in the alcohol purchase task.

    Science.gov (United States)

    Kaplan, Brent A; Reed, Derek D; Murphy, James G; Henley, Amy J; Reed, Florence D DiGennaro; Roma, Peter G; Hursh, Steven R

    2017-06-01

    Hypothetical purchase tasks have advanced behavioral economic evaluations of demand by circumventing practical and ethical restrictions associated with delivering drug reinforcers to participants. Numerous studies examining the reliability and validity of purchase task methodology suggest that it is a valuable method for assessing demand that warrants continued use and evaluation. Within the literature examining purchase tasks, the alcohol purchase task (APT) has received the most investigation, and currently represents the most experimentally validated variant. However, inconsistencies in purchase task methodology between studies exist, even within APT studies, and, to date, none have assessed the influence of experimental economic constraints on responding. This study examined changes in Q0 (reported consumption when drinks are free), breakpoint (price that suppresses consumption), and α (rate of change in demand elasticity) in the presence of different hypothetical durations of access to alcohol in an APT. One hundred seventy-nine participants (94 males, 85 females) from Amazon Mechanical Turk completed 3 APTs that varied in the duration of time at a party (i.e., access to alcoholic beverages) as described in the APT instructions (i.e., vignette). The 3 durations included 5-hr (used by Murphy et al., 2013), 1-hr, and 9-hr time frames. We found that hypothetical duration of access was significantly related to Q0 and breakpoint at the individual level. Additionally, group-level mean α decreased significantly with increases in duration of access, thus indicating relatively higher demand for alcohol with longer durations of access. We discuss implications for conducting hypothetical purchase task research and alcohol misuse prevention efforts. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Physical Demands Study - Focus Groups

    Science.gov (United States)

    2015-10-26

    and the rounds in the boxes weigh 35 lb, which is lighter than equipment handled in the other physically demanding job tasks already identified...and standards. Ergonomics . 53: 858-871. 40 Appendix A: Questionnaires Completed by Volunteers prior to each Focus Group Interview 1 2 3 4a 4b 5

  5. Multi-task connectivity reveals flexible hubs for adaptive task control

    Science.gov (United States)

    Cole, Michael W.; Reynolds, Jeremy R.; Power, Jonathan D.; Repovs, Grega; Anticevic, Alan; Braver, Todd S.

    2013-01-01

    Extensive evidence suggests the human ability to adaptively implement a wide variety of tasks is preferentially due to the operation of a fronto-parietal brain network. We hypothesized that this network’s adaptability is made possible by ‘flexible hubs’ – brain regions that rapidly update their pattern of global functional connectivity according to task demands. We utilized recent advances in characterizing brain network organization and dynamics to identify mechanisms consistent with the flexible hub theory. We found that the fronto-parietal network’s brain-wide functional connectivity pattern shifted more than other networks’ across a variety of task states, and that these connectivity patterns could be used to identify the current task. Further, these patterns were consistent across practiced and novel tasks, suggesting reuse of flexible hub connectivity patterns facilitates adaptive (novel) task performance. Together, these findings support a central role for fronto-parietal flexible hubs in cognitive control and adaptive implementation of task demands generally. PMID:23892552

  6. Review of current Southern California edison load management programs and proposal for a new market-driven, mass-market, demand-response program

    Energy Technology Data Exchange (ETDEWEB)

    Weller, G.H.

    2002-01-01

    Utility load management programs, including direct load control and interruptible load programs, constitute a large installed base of controllable loads that are employed by utilities as system reliability resources. In response to energy supply shortfalls expected during the summer of 2001, the California Public Utilities Commission in spring 2001 authorized new utility load management programs as well as revisions to existing programs. This report provides an independent review of the designs of these new programs for a large utility (Southern California Edison) and suggests possible improvements to enhance the price responsiveness of the customer actions influenced by these programs. The report also proposes a new program to elicit a mass-market demand response to utility price signals.

  7. Cognitive Modeling for Closed-Loop Task Mitigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As flightdeck equipment becomes more sophisticated and complex, operations become significantly more cognitively demanding. When tasks demands exceed the operator's...

  8. No effect of anodal transcranial direct current stimulation over the motor cortex on response-related ERPs during a conflict task.

    Directory of Open Access Journals (Sweden)

    Alexander Christian Conley

    2016-08-01

    Full Text Available Anodal transcranial direct current stimulation (tDCS over the motor cortex is considered a potential treatment for motor rehabilitation following stroke and other neurological pathologies. However, both the context under which this stimulation is effective and the underlying mechanisms remain to be determined. In this study, we examined the mechanisms by which anodal tDCS may affect motor performance by recording event-related potentials (ERPs during a cued go/nogo task after anodal tDCS over dominant M1 in young adults (Experiment 1 and both dominant and non-dominant M1 in old adults (Experiment 2. In both experiments, anodal tDCS had no effect on either response time or response-related ERPs, including the cue-locked contingent negative variation (CNV and both target-locked and response-locked lateralised readiness potentials (LRP. Bayesian model selection analyses showed that, for all measures, the null effects model was stronger than a model including anodal tDCS vs. sham. We conclude that anodal tDCS has no effect on response time or response-related ERPs during a cued go/nogo task in either young or old adults.

  9. Effect of transcranial direct current stimulation on prefrontal inhibition in schizophrenia patients with persistent auditory hallucinations: A study on antisaccade task performance

    Directory of Open Access Journals (Sweden)

    Aditi Subramaniam

    2015-01-01

    Full Text Available Background: Deficient prefrontal cortex inhibitory control is of particular interest with regard to the pathogenesis of auditory hallucinations (AHs in schizophrenia. Antisaccade task performance is a sensitive index of prefrontal inhibitory function and has been consistently found to be abnormal in schizophrenia. Methods: This study investigated the effect of transcranial direct current stimulation (tDCS on antisaccade performance in 13 schizophrenia patients. Results: The tDCS resulted in significant reduction in antisaccade error percentage (t = 3.4; P = 0.005, final eye position gain (t = 2.3; P = 0.042, and AHs severity (t = 4.1; P = 0.003. Conclusion: Our results raise the possibility that improvement in antisaccade performance and severity of AH may be mechanistically related.

  10. 产妇在分娩期需求的研究现状%The current research status of women in demand during delivery

    Institute of Scientific and Technical Information of China (English)

    王莲萍

    2015-01-01

    With the development of science and the progress of the society, the demands on health and quality of life of people constantly improve, medical service model from based on disease, guided by the experience of the model into a people-oriented, guided by the evidence-based medicine model. Modern obstetric medical service also from physiology, psychology, environment and other aspects provide lying-in women with humanity, personalized service.%随着科学的发展和社会的进步, 人们对健康和生活质量的要求不断地提高,医学服务模式已从以病为本、以经验为指导的模式转变为以人为本、以循证医学为指导的模式.现代产科医疗服务也应从生理、心理、环境等的方面为产妇提供人性化、个性化的服务.

  11. Assessing the utility of a demand assessment for functional analysis.

    Science.gov (United States)

    Roscoe, Eileen M; Rooker, Griffin W; Pence, Sacha T; Longworth, Lynlea J

    2009-01-01

    We evaluated the utility of an assessment for identifying tasks for the functional analysis demand condition with 4 individuals who had been diagnosed with autism. During the demand assessment, a therapist presented a variety of tasks, and observers measured problem behavior and compliance to identify demands associated with low levels of compliance or high levels of problem behavior (low-probability demands) and demands associated with high levels of compliance or low levels of problem behavior (high-probability demands). Results showed that clearer functional analysis outcomes were obtained for 3 of the 4 participants when low-probability rather than high-probability demands were used.

  12. Task-based Language Teaching in College English Instruction

    Institute of Scientific and Technical Information of China (English)

    Bo Jiang

    2012-01-01

      The current English teaching in colleges is still characterized by the adoption of the traditional teaching method,which is known as the 3Ps approach(presentation,practice,production)and in which student participation and interaction are quite limited. Task-based language teaching(TBLT),a further development of communicative language teaching,seems to satisfy such demands by converting the communicative language teaching principles into a practical classroom teaching model. There are six important principles of designing tasks. Based on the principles of designing tasks a procedure for TBLT can be proposed.

  13. A quantification of the physiological demands of the army emergency responder in the Australian army.

    Science.gov (United States)

    Tofari, Paul J; Laing Treloar, Alison K; Silk, Aaron J

    2013-05-01

    The Australian Defence Force is reviewing the physical demands of all employment categories in the Australian Army to establish valid and legally defensible assessments. The current assessments, performed in physical training attire, are not specific to job demands. Moreover, the fitness standards decrease based on age and are lower for females, and as job requirements are constant, these assessments are counterintuitive. With regard to the Army Emergency Responder employment category, tasks of physical demand in the present study were selected through consultation with subject-matter experts. Participants consisted of 10 qualified Army Emergency Responder soldiers and three noncareer firefighters under instruction. Real-life firefighting scenarios were witnessed by researchers and helped form task simulations allowing measurement of heart rate and oxygen consumption. Peak oxygen consumption ranged from 21.8 ± 3.8 to 40.0 ± 3.4 mL kg(-1) min(-1) during cutting activities and a search and rescue task, respectively, representing values similar to or higher than the current entry standards. Manual handling tasks were also assessed, with the heaviest measured being two soldiers lifting a 37.7-kg Utility Trunk to 150 cm. The findings provide a quantitative assessment of the physiological demands of Army Emergency Responders, and highlight the need for change in current fitness assessments.

  14. Demands Set Upon Modern Cartographic Visualization

    Directory of Open Access Journals (Sweden)

    Stanislav Frangeš

    2007-05-01

    Full Text Available Scientific cartography has the task to develop and research new methods of cartographic visualization. General demands are set upon modern cartographic visualization, which encompasses digital cartography and computer graphics: legibility, clearness, accuracy, plainness and aesthetics. In this paper, it is explained in detail what demands should be met in order to satisfy the general demands set. In order to satisfy the demand of legibility, one should respect conditions of minimal sizes, appropriate graphical density and better differentiation of known features. Demand of clearness needs to be met by fulfilling conditions of simplicity, contrasting quality and layer arrangement of cartographic representation. Accuracy, as the demand on cartographic visualization, can be divided into positioning accuracy and accuracy signs. For fulfilling the demand of plainness, the conditions of symbolism, traditionalism and hierarchic organization should be met. Demand of aesthetics will be met if the conditions of beauty and harmony are fulfilled.

  15. Report of the Task Group 186 on model-based dose calculation methods in brachytherapy beyond the TG-43 formalism: Current status and recommendations for clinical implementation

    Energy Technology Data Exchange (ETDEWEB)

    Beaulieu, Luc [Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Centre hospitalier universitaire de Quebec, Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1R 2J6 (Canada); Carlsson Tedgren, Asa [Department of Medical and Health Sciences (IMH), Radiation Physics, Faculty of Health Sciences, Linkoeping University, SE-581 85 Linkoeping (Sweden) and Swedish Radiation Safety Authority, SE-171 16 Stockholm (Sweden); Carrier, Jean-Francois [Departement de radio-oncologie, CRCHUM, Centre hospitalier de l' Universite de Montreal, Montreal, Quebec H2L 4M1 (Canada) and Departement de physique, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada); and others

    2012-10-15

    The charge of Task Group 186 (TG-186) is to provide guidance for early adopters of model-based dose calculation algorithms (MBDCAs) for brachytherapy (BT) dose calculations to ensure practice uniformity. Contrary to external beam radiotherapy, heterogeneity correction algorithms have only recently been made available to the BT community. Yet, BT dose calculation accuracy is highly dependent on scatter conditions and photoelectric effect cross-sections relative to water. In specific situations, differences between the current water-based BT dose calculation formalism (TG-43) and MBDCAs can lead to differences in calculated doses exceeding a factor of 10. MBDCAs raise three major issues that are not addressed by current guidance documents: (1) MBDCA calculated doses are sensitive to the dose specification medium, resulting in energy-dependent differences between dose calculated to water in a homogeneous water geometry (TG-43), dose calculated to the local medium in the heterogeneous medium, and the intermediate scenario of dose calculated to a small volume of water in the heterogeneous medium. (2) MBDCA doses are sensitive to voxel-by-voxel interaction cross sections. Neither conventional single-energy CT nor ICRU/ICRP tissue composition compilations provide useful guidance for the task of assigning interaction cross sections to each voxel. (3) Since each patient-source-applicator combination is unique, having reference data for each possible combination to benchmark MBDCAs is an impractical strategy. Hence, a new commissioning process is required. TG-186 addresses in detail the above issues through the literature review and provides explicit recommendations based on the current state of knowledge. TG-43-based dose prescription and dose calculation remain in effect, with MBDCA dose reporting performed in parallel when available. In using MBDCAs, it is recommended that the radiation transport should be performed in the heterogeneous medium and, at minimum, the dose to

  16. Current situation of domestic PVC cable industry and its demand for PVC resin%我国PVC电缆料行业现状及对PVC树脂的需求

    Institute of Scientific and Technical Information of China (English)

    刘家栋

    2001-01-01

    Current situation of domestic PVC cable industry and its new demand of PVC cable materials are introduced. PVC resin with uniform molecular weight distribution, dull PVC resin,bulk PVC resin and PVC resin with high polymerization degree are required in PVC cable industry.%介绍了我国PVC电缆料行业的现状及线缆业对PVC电缆料的新需求。提出了PVC电缆料行业对分子质量分布均匀的PVC树脂、PVC消光树脂、本体法PVC树脂及高聚合度PVC树脂的需求。

  17. Demand Response as a System Reliability Resource

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Lewis, Nancy Jo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Watson, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Auslander, David [Univ. of California, Berkeley, CA (United States); Paprotny, Igor [Univ. of California, Berkeley, CA (United States); Makarov, Yuri [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-12-31

    The Demand Response as a System Reliability Resource project consists of six technical tasks: • Task 2.1. Test Plan and Conduct Tests: Contingency Reserves Demand Response (DR) Demonstration—a pioneering demonstration of how existing utility load-management assets can provide an important electricity system reliability resource known as contingency reserve. • Task 2.2. Participation in Electric Power Research Institute (EPRI) IntelliGrid—technical assistance to the EPRI IntelliGrid team in developing use cases and other high-level requirements for the architecture. • Task 2.3. Research, Development, and Demonstration (RD&D) Planning for Demand Response Technology Development—technical support to the Public Interest Energy Research (PIER) Program on five topics: Sub-task 1. PIER Smart Grid RD&D Planning Document; Sub-task 2. System Dynamics of Programmable Controllable Thermostats; Sub-task 3. California Independent System Operator (California ISO) DR Use Cases; Sub-task 4. California ISO Telemetry Requirements; and Sub-task 5. Design of a Building Load Data Storage Platform. • Task 2.4. Time Value of Demand Response—research that will enable California ISO to take better account of the speed of the resources that it deploys to ensure compliance with reliability rules for frequency control. • Task 2.5. System Integration and Market Research: Southern California Edison (SCE)—research and technical support for efforts led by SCE to conduct demand response pilot demonstrations to provide a contingency reserve service (known as non-spinning reserve) through a targeted sub-population of aggregated residential and small commercial customers enrolled in SCE’s traditional air conditioning (AC) load cycling program, the Summer Discount Plan. • Task 2.6. Demonstrate Demand Response Technologies: Pacific Gas and Electric (PG&E)—research and technical support for efforts led by PG&E to conduct a demand response pilot demonstration to provide non

  18. Demand-Side Energy Management

    NARCIS (Netherlands)

    Molderink, Albert; Iniewski, K.

    2012-01-01

    Concerns about climate change, increasing energy prices and dependability of energy supply ask for drastic changes in the energy supply chain, but also in the current demand-supply philosophy. Current trends in energy consumptions result in an increasing and more fluctuating electricity usage, causi

  19. Demand scenarios, worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A. [Massachusetts Inst. of Technology, Center for Technology, Policy and Industrial Development and the MIT Joint Program on the Science and Policy of Global Change, Cambridge, MA (United States)

    1996-11-01

    Existing methods are inadequate for developing aggregate (regional and global) and long-term (several decades) passenger transport demand scenarios, since they are mainly based on simple extensions of current patterns rather than causal relationships that account for the competition among transport modes (aircraft, automobiles, buses and trains) to provide transport services. The demand scenario presented in this paper is based on two empirically proven invariances of human behavior. First, transport accounts for 10 to 15 percent of household total expenditures for those owning an automobile, and around 5 percent for non-motorized households on average (travel money budget). Second, the mean time spent traveling is approximately one hour per capita per day (travel time budget). These two budgets constraints determine the dynamics of the scenario: rising income increases per capita expenditure on travel which, in turn, increase demand for mobility. Limited travel time constraints travelers to shift to faster transport systems. The scenario is initiated with the first integrated historical data set on traffic volume in 11 world regions and the globe from 1960 to 1990 for all major modes of motorized transport. World average per capita traffic volume, which was 1,800 kilometers in 1960 and 4,2090 in 1990, is estimated to rise to 7,900 kilometers in 2020 - given a modest average increase in Gross World Product of 1.9% per year. Higher economic growth rates in Asian regions result in an increase in regional per capita traffic volume up to a factor of 5.3 from 1990 levels. Modal splits continue shifting to more flexible and faster modes of transport. At one point, passenger cars can no longer satisfy the increasing demand for speed (i.e. rising mobility within a fixed time budget). In North America it is estimated that the absolute traffic volume of automobiles will gradually decline starting in the 2010s. (author) 13 figs., 6 tabs., 35 refs.

  20. 南京市养老地产的供需现状及开发对策%Study on the Current Supply and Demand Situation and Development Strategy of the Real Estate Provided for the Aged

    Institute of Scientific and Technical Information of China (English)

    刘月

    2015-01-01

    Nanjing city is one of the country's aging population with higher levels of city, the rapid pace of development, facing a severe test of the pension problem. Based on the current situation of Nanjing city housing supply and housing demand in the elderly elderly as the starting point,analysis of the current situation of the pension real estate development in Nanjing city and the development trend in the future. Through the questionnaire survey and the current situation of housing, Nanjing city elderly and elderly housing demand, there is a summary of Nanjing city at present endowment real estate development problems; try to judge the pension real estate market in Nanjing city and Nanjing city development stage, the three kinds of Pension --home care, community care and institutional care in the future the proportion of pension modechanges, which constitute the system of endowment real estate; national and internationalendowment of successful real estate development case, combined with China's pension policyinitiatives, from various measures more comprehensive perspective of Nanjing city pensionreal estate development.%以南京市老年住房的供给现状以及中老年住房需求为切入点,分析南京市养老地产开发的现状以及未来的发展趋势。通过问卷调查的形式分析南京市老年住房的现状及中老年住房需求,总结南京市目前养老地产开发过程中存在的问题。借鉴国外养老地产成功开发的案例,结合我国养老政策举措,研究南京市养老地产开发的对策。

  1. Designing for dynamic task allocation

    NARCIS (Netherlands)

    Dongen, C.J.G. van; Maanen, P.P. van

    2005-01-01

    Future platforms are envisioned in which human-machine teams are able to share and trade tasks as demands in situations change. It seems that human-machine coordination has not received the attention it deserves by past and present approaches to task allocation. In this paper a simple way to make co

  2. Dietetics supply and demand: 2010-2020.

    Science.gov (United States)

    Hooker, Roderick S; Williams, James H; Papneja, Jesleen; Sen, Namrata; Hogan, Paul

    2012-03-01

    The Academy of Nutrition and Dietetics, in conjunction with the Commission on Dietetic Registration (CDR), invited The Lewin Group to undertake an analysis of the dietetics workforce. The purpose of the workforce study was to develop a model that can project the supply and demand for both registered dietitians (RDs) and dietetic technicians, registered (DTRs) (collectively referred to as CDR-credentialed dietetics practitioners) as the result of various key drivers of change. The research team was asked to quantify key market factors where possible and to project likely paths for the evolution of workforce supply and demand, as well as to assess the implications of the findings. This article drew on the survey research conducted by Readex Research and futurist organizations such as Signature i and Trend Spot Consulting. Furthermore, members of the Dietetics Workforce Demand Task Force were a source of institutional and clinical information relevant to the credentialed dietetics workforce--including their opinions and judgment of the current state of the health care market for dietetic services, its future state, and factors affecting it, which were useful and were integrated with the objective sources of data. The model is flexible and accommodates the variation in how RDs and DTRs function in diverse practice areas. For purposes of this study and model, the dietetics workforce is composed of RDs and DTRs. This report presents the results of this workforce study and the methodology used to calculate the projected dietetics workforce supply and demand. The projections are based on historical trends and estimated future changes. Key findings of the study included the following: • The average age of all CDR-credentialed dietetics practitioners in baseline supply (2010) is 44 years; approximately 96% are women. • Approximately 55% of CDR-credentialed dietetics practitioners work in clinical dietetics. • The annual growth rate of supply of CDR

  3. Demand Curves for Hypothetical Cocaine in Cocaine-Dependent Individuals

    Science.gov (United States)

    Bruner, Natalie R.; Johnson, Matthew W.

    2013-01-01

    Rationale Drug purchasing tasks have been successfully used to examine demand for hypothetical consumption of abused drugs including heroin, nicotine, and alcohol. In these tasks drug users make hypothetical choices whether to buy drugs, and if so, at what quantity, at various potential prices. These tasks allow for behavioral economic assessment of that drug's intensity of demand (preferred level of consumption at extremely low prices) and demand elasticity (sensitivity of consumption to price), among other metrics. However, a purchasing task for cocaine in cocaine-dependent individuals has not been investigated. Objectives This study examined a novel Cocaine Purchasing Task and the relation between resulting demand metrics and self-reported cocaine use data. Methods Participants completed a questionnaire assessing hypothetical purchases of cocaine units at prices ranging from $0.01 to $1,000. Demand curves were generated from responses on the Cocaine Purchasing Task. Correlations compared metrics from the demand curve to measures of real-world cocaine use. Results Group and individual data were well modeled by a demand curve function. The validity of the Cocaine Purchasing Task was supported by a significant correlation between the demand curve metrics of demand intensity and Omax (determined from Cocaine Purchasing Task data) and self-reported measures of cocaine use. Partial correlations revealed that after controlling for demand intensity, demand elasticity and the related measure, Pmax, were significantly correlated with real-world cocaine use. Conclusions Results indicate that the Cocaine Purchasing Task produces orderly demand curve data, and that these data relate to real-world measures of cocaine use. PMID:24217899

  4. Demand curves for hypothetical cocaine in cocaine-dependent individuals.

    Science.gov (United States)

    Bruner, Natalie R; Johnson, Matthew W

    2014-03-01

    Drug purchasing tasks have been successfully used to examine demand for hypothetical consumption of abused drugs including heroin, nicotine, and alcohol. In these tasks, drug users make hypothetical choices whether to buy drugs, and if so, at what quantity, at various potential prices. These tasks allow for behavioral economic assessment of that drug's intensity of demand (preferred level of consumption at extremely low prices) and demand elasticity (sensitivity of consumption to price), among other metrics. However, a purchasing task for cocaine in cocaine-dependent individuals has not been investigated. This study examined a novel Cocaine Purchasing Task and the relation between resulting demand metrics and self-reported cocaine use data. Participants completed a questionnaire assessing hypothetical purchases of cocaine units at prices ranging from $0.01 to $1,000. Demand curves were generated from responses on the Cocaine Purchasing Task. Correlations compared metrics from the demand curve to measures of real-world cocaine use. Group and individual data were well modeled by a demand curve function. The validity of the Cocaine Purchasing Task was supported by a significant correlation between the demand curve metrics of demand intensity and O max (determined from Cocaine Purchasing Task data) and self-reported measures of cocaine use. Partial correlations revealed that after controlling for demand intensity, demand elasticity and the related measure, P max, were significantly correlated with real-world cocaine use. Results indicate that the Cocaine Purchasing Task produces orderly demand curve data, and that these data relate to real-world measures of cocaine use.

  5. Research on the Current Supply-and-Demand of Fitness and Recreation Market in Hebei Province%河北省体育健身娱乐市场供求现状研究

    Institute of Scientific and Technical Information of China (English)

    赵文阁; 王立男

    2012-01-01

    运用文献资料、问卷调查、观察、数理统计、逻辑分析等研究方法,对河北省体育健身娱乐市场的供求状况进行了调查分析,揭示了市场的现状特征及存在的问题,并据此提出了拓展河北省体育健身娱乐市场的若干对策。%This study investigates the current market in its supply and demand of the fitness and recreation supplies.The research methodology takes the forms of documentation,questionnaires,observation,mathematical statistics and logical analysis.The results reveal the present features of market and the existing problems.Moreover,it provides strategies and solutions for exploiting the fitness and recreation market in Hebei Province.

  6. Demand Forecasting Errors

    OpenAIRE

    Mackie, Peter; Nellthorp, John; Laird, James

    2005-01-01

    Demand forecasts form a key input to the economic appraisal. As such any errors present within the demand forecasts will undermine the reliability of the economic appraisal. The minimization of demand forecasting errors is therefore important in the delivery of a robust appraisal. This issue is addressed in this note by introducing the key issues, and error types present within demand fore...

  7. Social obstacles in curbing residential energy demand

    Energy Technology Data Exchange (ETDEWEB)

    Anker-Nilssen, Per [Norwegian School of Management BI, Sandvika (Norway). Centre for Energy and Environment

    2003-07-01

    The continuing growth in residential energy-use does not comply with policy targets for curbing end-user demand. Households are steadily increasing their energy-use, offsetting energy efficiency improvements, to gain time, convenience, comfort and mobility. If sustainable development presupposes lowering demand, it conflicts with present energy-driven changes in life-styles. Environmental degradation due to energy-use gives incentives to raise taxes and duties. The Norwegian experience is that rising income increase households' energy consumption while decreasing its share of total expense. Consequently, higher prices hit low-income households that account for a minor share of total household demand. Since energy represents a purchased input factor to accomplish tasks, the burden is twofold. Energy consumption losses also represent the loss of time and thus money. Additionally, these households have less financial reserves to invest in energy saving. Hence, impact of price hikes (e.g. cold weather) has a regressive social effect. This paper argues that heavy taxation of end-user energy within current practices including tax recycling or deduction, is neither advisable nor politically viable to obtain set targets. Panel data of individual households' electricity use in Oslo suggests that low-income households can not counteract sudden price-hikes but adjust long-term, while the opposite applies to high-income households. In the discussion on environmental policy towards energy-use, the socio-economic effect of measures must be emphasised. New conceptualisations of the world-wide problems in energy and mobility that transforms into agreements on e.g. emission control, can result in added burdens on the poor in industrialised countries rather than the developing countries at large.

  8. Meeting increased demand.

    Science.gov (United States)

    Blair, Andrew

    2004-07-01

    New Zealand is a little country with a little economy but with a population that's rapidly aging. New Zealand's population is only 4.3 million people. It's GDP is only $US58.6 billion (2002). New Zealand's expenditure on health as a percentage of GDP is not out of line with that of other countries. As a nation we have been increasing expenditure on health over recent years. In 1990 we spent 7% of GDP on health. In 1995 that increased to 7.65% and is now 8.3%. However, in per capita terms our expenditure on health does not compare so well with like countries. The size of New Zealand's economy is restricting what our country spends on health. Health is already the second highest demand on the New Zealand tax dollar. The tolerance of New Zealanders would be challenged if a Government attempted to increase taxes further to meet the growing demands for expenditure on health, but at the same time the population's expectations are increasing. This is the challenging situation we face today. What lies ahead? Like all industrialized countries New Zealand is facing an aging population. The population below age 40 is decreasing, but it is increasing significantly over that age. 16% of the population is currently aged over 60. By 2051 this proportion will almost double to just over 31%. Coupled with the aging population is increased awareness and expectations, as access to options for treatment and technology becomes readily accessible to the population through such media as the internet. The extent of the impact of the aging population can be clearly represented by focusing on one specialty such as orthopaedics. The New Zealand Orthopaecic Association undertook a study in July 2003 which concluded (among other things) that as a result of the projected aging of the population, over the next 50 years: Musculo-skeletal operations will increase by over 30%. The number of hip replacements will nearly double. The incidence of osteoporosis will increase by a massive 201%. The number

  9. Linking meters and markets: Roles and incentives to support a flexible demand side

    DEFF Research Database (Denmark)

    Katz, Jonas

    2014-01-01

    participants. The roll-out of smart metering to electricity consumers is an important precondition to establishing a flexible demand side and will provide essential information flows. On the basis of current incentive structures and related risks, however, the pass-through of information and value from...... wholesale market participants to the demand side is mostly infeasible, resulting in flexibility tasks being aggregated and delegated to balancing responsible wholesale traders. This analysis focuses on whether current incentives and roles are appropriate and where the design could be improved to establish...... a flexible demand side with a particular focus on the Danish case. Design-related barriers are identified that affect expected value, associated risks, and the distribution of responsibilities. This serves as a basis to define policy options in the context of Nordic electricity markets. © 2014 Elsevier Ltd...

  10. Nicotine improves antisaccade task performance without affecting prosaccades.

    Science.gov (United States)

    Larrison, Abigail L; Briand, Kevin A; Sereno, Anne B

    2004-08-01

    Although there is ample evidence for a cognitive-attentional benefit of the stimulant nicotine, the source of this benefit is not as well understood. One approach is to address what aspects of performance nicotine affects at a functional systems level. It is currently debated whether the benefits produced by nicotine are the effect of enhanced higher cognitive function or reflect an overall increase in general arousal. In order to address this question, the effects of nicotine on two simple eye movement tasks were studied: the saccade (S) and antisaccade (AS) tasks. Because the S and AS tasks utilize identical sensory stimuli (peripheral targets) and require identical motor responses (eye movements) but differ significantly in their cognitive demands, the use of these two tasks should enable a parsing of nicotine effects on cognitive versus sensory-motor processes. In this study, the S and AS tasks were performed by two experimental groups, task naïve subjects and highly practised subjects. For the first group, that of the task naïve subjects, nicotine gum administration resulted in a decrease in AS errors. For the second group, that of two experienced subjects tested repeatedly over a 3 week period, nicotine also produced a significant decrease in AS task errors, as well as resulting in a significant decrease in AS response times. Neither task naïve nor experienced subjects showed any effects of nicotine on the S task. Examining the effects of nicotine on highly controlled and constrained tasks such as the S and AS task may provide another level of insight into the mechanisms underlying the beneficial cognitive effects of nicotine. Copyright 2004 John Wiley & Sons, Ltd.

  11. Knowledge acquisition and interface design for learning on demand systems

    Science.gov (United States)

    Nelson, Wayne A.

    1993-01-01

    The rapid changes in our world precipitated by technology have created new problems and new challenges for education and training. A knowledge 'explosion' is occurring as our society moves toward a service oriented economy that relies on information as the major resource. Complex computer systems are beginning to dominate the workplace, causing alarming growth and change in many fields. The rapidly changing nature of the workplace, especially in fields related to information technology, requires that our knowledge be updated constantly. This characteristic of modern society poses seemingly unsolvable instructional problems involving coverage and obsolescence. The sheer amount of information to be learned is rapidly increasing, while at the same time some information becomes obsolete in light of new information. Education, therefore, must become a lifelong process that features learning of new material and skills as needed in relation to the job to be done. Because of the problems cited above, the current model of learning in advance may no longer be feasible in our high-technology world. In many cases, learning in advance is impossible because there are simply too many things to learn. In addition, learning in advance can be time consuming, and often results in decontextualized knowledge that does not readily transfer to the work environment. The large and growing discrepancy between the amount of potentially relevant knowledge available and the amount a person can know and remember makes learning on demand an important alternative to current instructional practices. Learning on demand takes place whenever an individual must learn something new in order to perform a task or make a decision. Learning on demand is a promising approach for addressing the problems of coverage and obsolescence because learning is contextualized and integrated into the task environment rather than being relegated to a separate phase that precedes work. Learning on demand allows learners

  12. Stability of Money Demand Function in Pakistan

    Directory of Open Access Journals (Sweden)

    Haroon Sarwar

    2013-09-01

    Full Text Available The role, which money demand function plays in monetary policy formulation has attracted a lot of research studies to analyze this macroeconomic phenomenon. In the wake of current global and local economic and political upheavals, it is imperative to revisit the stability of money demand function. The study used the time series data and applied latest econometric techniques to find out the long run and short run money demand relationship. Moreover, all the three official monetary aggregates were used for finding out the most stable monetary demand relationship, which could provide correct signals for monetary policy formulation. The study found that broader monetary aggregate (M2 was the proper aggregate, which provided stable money demand function for Pakistan. The real GDP was positively related to the demand for real balances, while opportunity cost of money was negatively related. The study found that the role of financial innovation, in explaining the demand for money warrants attention in formulating monetary policy.

  13. Fundamental Geological Survey in China: Current Situation and Demands during “The 12th Five-Year Plan” Period%中国基础地质调查现状及其“十二五”需求

    Institute of Scientific and Technical Information of China (English)

    曾杰; 李江风

    2012-01-01

    分析基础地质调查面临的国际形势和宏观经济发展对其提出的客观需求,是科学部署“十二五”期间我国基础地质调查工作任务的基本依据,有利于强化其对经济社会全面可持续发展的支撑作用.在全面总结我国基础地质调查的现状与成果的基础上,定性分析了其面临的经济全球化与全球气候变暖形势,指出我国地球科学进步、资源安全保障、海洋权益维护、城市建设及现代农业发展对加大基础地质调查力度与广度的现实需求,提出应加强小比例尺基础地质调查成果的集成与社会化服务,推进中比例尺调查成果更新和领域拓展,强化重点区域和重要城市的大比例尺调查工作.%The analysis of the international trends and the requirements of macroeconomic development to the fundamental geological survey is the basis for the scientific arrangement of the fundamental geological survey tasks in the 12th Five-year Plan period, which is beneficial to strengthening the support of the fundamental geological survey to the sustainable economic and social development. Based on a comprehensive summary of the achievements of China's fundamental geological survey, this paper qualitatively analyzes the situation of economic globalization and global warming, and then points out the actual demands for the fundamental geological survey in terms of the advancement of earth science, the guarantee of resources supply, the maintenance of maritime rights and interests, as well as urban and modern agricultural development. Finally it proposes that during the 12th Five-year Plan period, the fundamental geological survey in China needs to improve the integration and social service of the fundamental geological survey results at small-scale level, promote the renewal and extension of the results at medium-scale level, and enhance investigation work in key areas and cities at large-scale level.

  14. Demand as frequency controlled reserve

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Togeby, M.; OEstergaard, J.

    2008-09-15

    Using demand as frequency controlled reserve (DFR) is an emerging technology which allow demand to participate actively in maintaining the system operation without reducing the energy service delivered to the customer and without need of user interaction. The basic premise is that traditional frequency controlled reserves from power plants and interconnections with neighbouring systems can be costly, slow and not fulfil the need for future power grids with a high share of wind power and fewer central power plants, and an intention to perform flexible operation such as is landing. Electricity demands, on the other hand, have advantages as frequency reserve including fast activation speed, smooth linear activation, low expected costs, and well-dispersed in the distribution grid. The main challenge of DFR is new methods for monitoring the available capacity. This project has investigated the technology of using electricity demands for providing frequency reserve to power systems. Within the project the potential and economy of DFR compatible loads in Denmark has been investigated, control logic has been designed, power system impact has been investigated, potential business models has been evaluated and an implementation strategy has been suggested. The tasks and goals of the project have been successfully accomplished based on which the conclusion and future recommendation are made. This project has developed the DFR technology that enables electricity demands to autonomously disconnect or reconnect to the grid in response to system frequency variations. The developed DFR technology is proved to be a promising technology from several perspectives. Technically, using DFR is feasible to provide reserves and enhance power system frequency control, while fulfilling technical requirements such as linear activation (or reconnection) according to frequency (or time). Environmentally, the DFR technology is pollution free in contrast to traditional reserves from generation

  15. 失能老年人的生活状况和社区照护服务需求研究%Study on Current Life Situation and Community Care Service Demand of Disabled Elders

    Institute of Scientific and Technical Information of China (English)

    姜向群; 刘妮娜; 魏蒙

    2014-01-01

    This paper uses the datum of survey on the basic situation and service demand for the elderly in Xicheng District in Beijing from Gerontology Institute of Renmin University, and analyzes their current life situation and care service demand. The reality reveals that there has been a low degree of utilization of community service facilities for disabled elders. Besides, community service items have been in shortage and had low supply rate. Accordingly, this study recognized that the advancement of social services for disabled elders can be conducted from two aspects: the short-term goals and long-term planning. On one hand, short-term goals include following items: providing corresponding services subsidies for disabled elders, transferring the core of community servicesfrom "entertainment" to "health maintenance" and properly handling the relationship among home-based care, institution care and family support for disabled elders, etc. On the other hand, the long-term planning covers establishment of system and mechanism of social services for disabled elders, furthermore, promotion of the market development of social services for disabled elders etc.%利用中国人民大学老年学研究所2013年对北京市西城区老年人基本情况和服务需求的调查数据,就失能老年人的生活状况和照护服务需求进行分析。失能老年人对社区养老服务设施的利用率低,社区照护服务项目及有效供给不足。可以从短期目标与长期规划两个方面着手推进失能老年人的社会服务发展。短期目标包括给予失能老年人相应服务补贴,社区服务重心由“娱乐型”向“医养型”转变,妥善处理失能老年人居家养老、机构养老与家庭养老的关系等;长期目标包括建立失能老年人社会服务机制、推进失能老年人社会服务市场化发展等。

  16. 老年残疾人家庭现状与需求特点分析%An Analysis of the Current Situation and the Demand Characteristics of Families with Elderly Disabled Members

    Institute of Scientific and Technical Information of China (English)

    赵建玲

    2014-01-01

    With the aging process of people with disabilities and the high risk for elderly people becoming disabled, both the scale of the elderly disabled and the number of families involved are increasing. Affected by the imbalance between supply and demand of the present social services, families with the elderly disabled are vulnerable groups in society. Mainly based on the data from the Second National Sample Survey on Disability, this paper describes the current situation and the demand characteristics of families with elderly disabled members, explores the design of social service system to meet their special needs, so that people with disabilities and their families can share the fruits of the economic and social development and enjoy a better life.%随着我国人口老龄化的加剧,残疾人老龄化和老年人残疾化的趋势越来越明显,老年残疾人规模庞大,所涉老年残疾人家庭的数量渐增。受目前社会服务的需求与供给不平衡的影响,他们成为社会中的弱势群体。通过利用第二次全国残疾人抽样调查等数据对老年残疾人家庭现状、需求特点等方面的描述性统计,对构建以满足老年残疾人家庭需要为取向的社会服务体系进行了试探性思考,旨在引起有关方面对老年残疾人家庭的了解与重视,采取相应措施,回应老年残疾人及其家庭的特殊需求,使他们能够共享经济社会发展成果,安享美好人生。

  17. Innovation and Demand

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2007-01-01

    the demand-side of markets in the simplest possible way. This strategy has allowed a gradual increase in the sophistication of supply-side aspects of economic evolution, but the one-sided focus on supply is facing diminishing returns. Therefore, demand-side aspects of economic evolution have in recent years...... received increased attention. The present paper argues that the new emphasis on demand-side factors is quite crucial for a deepened understanding of economic evolution. The major reasons are the following: First, demand represents the core force of selection that gives direction to the evolutionary process....... Second, firms' innovative activities relate, directly or indirectly, to the structure of expected and actual demand. Third, the demand side represents the most obvious way of turning to the much-needed analysis of macro-evolutionary change of the economic system....

  18. PERFECT DEMAND ILLUSION

    Directory of Open Access Journals (Sweden)

    Alexander Yu. Sulimov

    2015-01-01

    Full Text Available The article is devoted to technique «Perfect demand illusion», which allows to strengthen the competitive advantageof retailers. Also in the paper spells out the golden rules of visual merchandising.The definition of the method «Demand illusion», formulated the conditions of its functioning, and is determined by the mainhypothesis of the existence of this method.Furthermore, given the definition of the «Perfect demand illusion», and describes its additional conditions. Also spells out the advantages of the «Perfect demandillusion», before the «Demand illusion».

  19. Divers of Passenger Demand

    OpenAIRE

    Wittmer, Andreas

    2011-01-01

    -Overview drivers of passenger demand -Driver 1: Economic growth in developing countries -Driver 2: International business travel in developed countries -Driver 3: International leisure travel in developed countries

  20. Demand-side Management, Supply-side Management and Current Macro-policy Choic%需求管理、供给管理及当前宏观政策选择

    Institute of Scientific and Technical Information of China (English)

    李义平

    2016-01-01

    纵观市场经济国家从需求管理到供给管理的发展过程,并从需求管理及供给管理理论的特点及旨在解决问题出发,可以看出,我国当前经济面临的主要问题是结构调整和创新问题。选择供给管理的宏观经济政策是必要的。然而,供给管理必须要有适合的制度安排,这个制度的安排实质上是一个制度的变革问题。它包括加大真正的企业的供给、与市场经济相适应的政府职能转变、创新的制度安排等等。%This article explores how the country who uses a market economy walks from the supply side to the demand side on the way of macroeconomic manage-ment based on the problems these two arts or sciences are designed to deal with and an analysis of their characteristics. As the primary issues facing Chi-na’s current state of economy, innovation and structural adjustment, it argues, lead to urgent requirements for reforms on supply - side management and new institutional arrangements relevant to it.

  1. Scientific and Technical Demand and Current Situations of Cassava Biomass Energy Industry in China%我国木薯生物质能源产业发展现状与科技需求

    Institute of Scientific and Technical Information of China (English)

    韦昌联; 卢柳忠; 黎贞崇

    2012-01-01

    Based on the analysis of current situations of cassava biomass energy industry in China and the relative advances in science and technology,the major existed problems in this industry were put forward.Furthermore,scientific and technical demands for further development of cassava biomass energy industry were discussed covering the following aspects:strengthening the research on the culture and the matching cultivation technology of new varieties of high-yield high-starch cassava,launching the development of cassava full-process automated manufacturing equipments,strengthening the research on cassava comprehensive utilization and the development of new cassava products,and strengthening the research on the recycle use of cassava waste and the relative techniques.%在分析我国木薯生物质能源产业现状和科技发展进展的基础上,指出了当前木薯生物质能源产业科技发展存在的主要问题。提出了下一步产业发展的科技需求,重点是加强高产高粉木薯新品种培育和配套栽培技术研究,开展木薯全程机械化系列产品的研发,加强木薯综合利用技术和产品攻关及木薯废弃物的资源化利用技术的研发力度。

  2. Effects of a no-go Task 2 on Task 1 performance in dual - tasking: From benefits to costs.

    Science.gov (United States)

    Janczyk, Markus; Huestegge, Lynn

    2017-04-01

    When two tasks are combined in a dual-task experiment, characteristics of Task 2 can influence Task 1 performance, a phenomenon termed the backward crosstalk effect (BCE). Besides instances depending on the (spatial) compatibility of both responses, a particularly interesting example was introduced by Miller (2006): If Task 2 was a no-go task (i.e., one not requiring any action at all), responses were slowed in Task 1. Subsequent work, however, also reported the opposite result-that is, faster Task 1 responses in cases of no-go Task 2 trials. We report three experiments aiming to more precisely identify the conditions under which a no-go Task 2 facilitates or impedes Task 1 performance. The results suggest that an adverse no-go BCE is only observed when the Task 2 response(s) are sufficiently prepared in advance, yielding strong inhibitory control demands for Task 2 that eventually hamper Task 1 processing as well (i.e., inhibitory costs). If this is not the case, encountering a no-go Task 2 trial facilitates Task 1 performance, suggesting that the underlying task representation is reduced to a single - task. These results are discussed in the context of other recent work on BCEs and of recently suggested accounts of the no-go BCE.

  3. Current guidelines for the evaluation and management of atopic dermatitis: A comparison of the Joint Task Force Practice Parameter and American Academy of Dermatology guidelines.

    Science.gov (United States)

    Eichenfield, Lawrence F; Ahluwalia, Jusleen; Waldman, Andrea; Borok, Jenna; Udkoff, Jeremy; Boguniewicz, Mark

    2017-04-01

    Atopic dermatitis (AD) is a chronic pruritic inflammatory disease that commonly presents in the pediatric population. Although definitions and diagnosis of AD have largely been agreed upon, allergists and dermatologists have similar and divergent approaches to the management of AD. This review facilitated integration of the American Academy of Allergy, Asthma & Immunology/American College of Allergy, Asthma & Immunology Joint Task Force 2012 AD Practice Parameter and the 2014 American Academy of Dermatology guidelines to highlight the basic principles of AD management and discuss therapies and management of AD from the distinct perspectives of the allergist and dermatologist. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  4. Stroop proactive control and task conflict are modulated by concurrent working memory load.

    Science.gov (United States)

    Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai; Davelaar, Eddy J; Usher, Marius

    2015-06-01

    Performance on the Stroop task reflects two types of conflict-informational (between the incongruent word and font color) and task (between the contextually relevant color-naming task and the irrelevant, but automatic, word-reading task). According to the dual mechanisms of control theory (DMC; Braver, 2012), variability in Stroop performance can result from variability in the deployment of a proactive task-demand control mechanism. Previous research has shown that when proactive control (PC) is diminished, both increased Stroop interference and a reversed Stroop facilitation (RF) are observed. Although the current DMC model accounts for the former effect, it does not predict the observed RF, which is considered to be behavioral evidence for task conflict in the Stroop task. Here we expanded the DMC model to account for Stroop RF. Assuming that a concurrent working memory (WM) task reduces PC, we predicted both increased interference and an RF. Nineteen participants performed a standard Stroop task combined with a concurrent n-back task, which was aimed at reducing available WM resources, and thus overloading PC. Although the results indicated common Stroop interference and facilitation in the low-load condition (zero-back), in the high-load condition (two-back), both increased Stroop interference and RF were observed, consistent with the model's prediction. These findings indicate that PC is modulated by concurrent WM load and serves as a common control mechanism for both informational and task Stroop conflicts.

  5. Paramedic Physical Demands Analysis

    Science.gov (United States)

    2014-07-01

    medical bags, cardiac monitor, stretcher, stair chair, etc.) were not standardized across services. As a result the total amount of equipment weight ...report describes the pushing/pulling, walking, and stair climbing demands as observed during the observation periods. Walking demands varied between the...standard deviation about the mean. .................................................................. 25 Figure 7 - The maximum weight (heaviest patient

  6. Wood supply and demand

    Science.gov (United States)

    Peter J. Ince; David B. McKeever

    2011-01-01

    At times in history, there have been concerns that demand for wood (timber) would be greater than the ability to supply it, but that concern has recently dissipated. The wood supply and demand situation has changed because of market transitions, economic downturns, and continued forest growth. This article provides a concise overview of this change as it relates to the...

  7. Causality in demand

    DEFF Research Database (Denmark)

    Nielsen, Max; Jensen, Frank; Setälä, Jari;

    2011-01-01

    This article focuses on causality in demand. A methodology where causality is imposed and tested within an empirical co-integrated demand model, not prespecified, is suggested. The methodology allows different causality of different products within the same demand system. The methodology is applied...... to fish demand. On the German market for farmed trout and substitutes, it is found that supply sources, i.e. aquaculture and fishery, are not the only determinant of causality. Storing, tightness of management and aggregation level of integrated markets might also be important. The methodological...... implication is that more explicit focus on causality in demand analyses provides improved information. The results suggest that frozen trout forms part of a large European whitefish market, where prices of fresh trout are formed on a relatively separate market. Redfish is a substitute on both markets...

  8. 家庭结构视角下的城乡养老现状与需求分析%Analysis on Current Situation and Demand of Elderly People in Urban and Rural under the Perspective of Family Structure

    Institute of Scientific and Technical Information of China (English)

    仇志娟; 杜昊

    2014-01-01

    By employing data of the third phase of Chinese w omen’s social status survey ,under the family structure perspective of elderly people ,this essay is an analysis of self‐caring ability ,current situation and demand of elderly people .The result reveals that couple core families ,three‐generation immediate families and single‐person households are three main types of structures for elderly people in China .In the urban area ,single person household structure is the weakest in caring for elderly people , and couple core families have comparatively better level .In the rural area ,three‐generation immediate families are the weakest in caring the old ,single‐person households and couple core families have better caring level .Urban family function in caring the elderly severely weakens compared that with the rural families ,urban single‐person households and three‐generation immediate families have better function in caring elderly people ,rural families much rely on sons in providing care for the old .Elderly people in the urban area have strong demand on health care and services .Different forms of caring for elderly people exist in the urban and rural areas ,and also in different family structures .%利用第三期中国妇女社会地位调查数据,基于城乡老年人口家庭结构视角,分析当前城乡不同家庭结构中老年人的自我养老状况、家庭养老现状以及养老需求。研究表明:夫妇核心家庭、三代直系家庭和单人户是城乡老年人口最主要的家庭类型;城市中单人户老年人的自我养老能力最差,夫妇核心家庭老年人的自我养老能力较强,农村中单人户和夫妇核心家庭老年人的自我养老较强,三代直系家庭老年人的自我养老能力最差;相比于农村,城市家庭养老功能已经弱化,城乡单人户和三代直系家庭养老状况好于夫妇核心家庭,农村养老仍是以“养儿防

  9. Enlightenment of Marx’s social reproduction theory on expanding our current domestic demands%马克思社会再生产理论对当前我国扩大内需的启示

    Institute of Scientific and Technical Information of China (English)

    许晓红

    2013-01-01

    Our country’s economic grow th mostly depends on export and investment ,and it is relatively low that consumption contributes to GDP .Under the influence of the financial crisis ,expanding our domestic demand certainly becomes the main approach for maintaining stable economic growth .This paper elaborates the content of Marx’s effective demand theory which is based on the perspective of social reproduction ,considers strategies of expanding domestic demand after the two times of financial crisis occur , and concludes that expanding domestic demand is the direction selection for China to develop our economy .Finally ,based on the analysis of the factors about restricting effective demand expansion ,this paper puts forward the path to expand our domestic demand .%一直以来,我国经济增长都以出口、投资推动为主,消费对GDP的贡献率偏低。在金融危机的影响下,扩大内需自然成为我国保持经济稳定增长的主要手段。本文阐述了马克思基于社会再生产的视角提出的有效需求理论的内容,联系中国在两次金融危机发生后实施的扩大内需政策,说明扩大内需是当前经济发展的方向性选择,在分析制约有效需求扩大的相关因素的基础上,提出相应的扩大内需的路径。

  10. Lower Extremity Biomechanical Demands During Saut de Chat Leaps.

    Science.gov (United States)

    Jarvis, Danielle N; Kulig, Kornelia

    2016-12-01

    In dance, high demands are placed on the lower extremity joints during jumping tasks. The purpose of this study was to compare biomechanical demands placed on the lower extremity joints during the takeoff and landing phases of saut de chat leaps.

  11. Behavioral and Electrophysiological Effects of Transcranial Direct Current Stimulation of the Parietal Cortex in a Visuo-Spatial Working Memory Task

    OpenAIRE

    Heimrath, K.; Sandmann, P.; Becke, A.; Müller, N G; Zaehle, T.

    2012-01-01

    Impairments of working memory (WM) performance are frequent concomitant symptoms in several psychiatric and neurologic diseases. Despite the great advance in treating the reduced WM abilities in patients suffering from, e.g., Parkinson’s and Alzheimer’s disease by means of transcranial direct current stimulation (tDCS), the exact neurophysiological underpinning subserving these therapeutic tDCS-effects are still unknown. In the present study we investigated the impact of tDCS on performance i...

  12. The cognitive demands of hypnotic response.

    Science.gov (United States)

    Wyzenbeek, Miriam; Bryant, Richard A

    2012-01-01

    This study tests the proposal that hypnotic responding is effortless. The authors compared the responses of high and low hypnotizable participants (N = 70) in and out of hypnosis on a dual-task paradigm in which they were required to maintain hypnotic blindness during presentation of visual stimuli of varying salience intensities while simultaneously completing a secondary task. Whereas high hypnotizable participants in both hypnosis and wake conditions reported comparable levels of conviction in the hallucination suggestion, hypnotized highs performed poorer on the secondary task when the stimulus was present. Performance on the secondary task deteriorated when the visual stimulus was intensified. These findings contradict the notion that hypnotic response is not demanding on cognitive resources and suggest that increased effort is required to resolve the extent of conflict between reality and suggestion.

  13. Dissecting the Clock: Understanding the mechanisms of timing across tasks and temporal intervals

    Science.gov (United States)

    Bangert, Ashley S.; Reuter-Lorenz, Patricia A.; Seidler, Rachael D.

    2010-01-01

    Currently, it is unclear what model of timing best describes temporal processing across millisecond and second timescales in tasks with different response requirements. In the present set of experiments, we assessed whether the popular dedicated scalar model of timing accounts for performance across a restricted timescale surrounding the 1 second duration for different tasks. The first two experiments evaluate whether temporal variability scales proportionally with the timed duration within temporal reproduction. The third experiment compares timing across millisecond and second timescales using temporal reproduction and discrimination tasks designed with parallel structures. The data exhibit violations of the assumptions of a single scalar timekeeper across millisecond and second timescales within temporal reproduction; these violations are less apparent for temporal discrimination. The finding of differences across tasks suggests that task demands influence the mechanisms that are engaged for keeping time. PMID:20955998

  14. Cognitive task demands modulate the sensitivity of the human cochlea

    Directory of Open Access Journals (Sweden)

    David W Smith

    2012-02-01

    Full Text Available Recent studies lead to the conclusion that focused attention, through the activity of corticofugal and medial olivocochlear efferent pathways, modulates activity at the most peripheral aspects of the auditory system within the cochlea. In two experiments we investigated the effects of different intermodal attention manipulations on the response of outer hair cells (OHCs, and the control exerted by the medial olivocochlear (MOC efferent system. The effect of the MOCs on OHC activity was characterized by measuring the amplitude and rapid adaptation time course of distortion product otoacoustic emissions (DPOAEs. In the first, DPOAE recordings were compared while participants were reading a book and counting the occurrence of the letter a (auditory ignoring and while counting the either short- or long-duration eliciting tones (auditory attending. In the second, DPOAEs were recorded while subjects watched muted movies with subtitles (auditory ignoring/visual distraction and were compared with DPOAEs recorded while subjects counted the same tones (auditory attending as in experiment 1. In both experiments 1 and 2, the absolute level of the averaged DPOAEs recorded during the auditory-ignoring condition was statistically higher than that recorded in the auditory-attending condition. Efferent-induced rapid adaptation was evident in all DPOAE contours, under all attention conditions, suggesting that two medial efferent processes act independently to determine rapid adaptation, which is unaffected by attention, and the overall DPOAE level, which is significantly affected by changes in the focus of attention.

  15. Spacecraft Demand Tasking and Skip Entry Responsive Maneuvers

    Science.gov (United States)

    2011-06-01

    various parking orbits in LEO. Situated below the primary payload, the secondary payloads are attached radially to the adapter ring as illustrated in...Steven R. “ Jurassic Technology: The History of the Dynasoar.” Crosslink. 2004. Available from http://www.aero.org/publications/crosslink/winter2004

  16. Domestic Demand Will Work

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China can invigorate its economy by expanding domestic demand and boosting consumption chinese bankers are preparing to set up finance companies that provide consumer loans in major cities like Beijing and Shanghai.

  17. Intelligent energy demand forecasting

    CERN Document Server

    Hong, Wei-Chiang

    2013-01-01

    This book offers approaches and methods to calculate optimal electric energy allocation, using evolutionary algorithms and intelligent analytical tools to improve the accuracy of demand forecasting. Focuses on improving the drawbacks of existing algorithms.

  18. Household fuel demand analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cohn, S.; Hirst, E.; Jackson, J.

    1976-01-01

    This study develops econometric models of residential demands for electricity, natural gas, and petroleum products. Fuel demands per household are estimated as functions of fuel prices, per capita income, heating degree days, and mean July temperature. Cross-sectional models are developed using a large data base containing observations for each state and year from 1951 through 1974. Long-run own-price elasticities for all three fuels are greater than unity with natural gas showing the greatest sensitivity to own-price changes. Cross-price elasticities are all less than unity except for the elasticity of demand for oil with respect to the price of gas (which is even larger than the own-price elasticity of demand for oil). The models show considerable stabiity with respect to own-price elasticities but much instability with respect to the cross-price and income elasticities.

  19. Impact of Energy Demands

    Science.gov (United States)

    Cambel, Ali B.

    1970-01-01

    The types of pollutants associated with the process of power production are identified. A nine-point proposal is presented on the ways the increase in power demands might be achieved with the minimum threat to the environment. (PR)

  20. The effect of task complexity and task conditions on foreign language development and performance: three empirical studies

    OpenAIRE

    Sercu, L.; Wachter, L; Peters, E.; Kuiken, F.; Vedder, I.

    2006-01-01

    It has been argued that tasks constitute a valid alternative unit to sequence the language learning process, as opposed to linguistically defined syllabuses. Implementing this claim presupposes that it is possible to access the cognitive and linguistic demands of tasks, so that they can be sequenced in such a way that they optimally support and promote the L2 learning process. Knowing what demands a task will make opens up the possibility of using task design to manipulate the learner's atten...

  1. Income distribution trends and future food demand.

    Science.gov (United States)

    Cirera, Xavier; Masset, Edoardo

    2010-09-27

    This paper surveys the theoretical literature on the relationship between income distribution and food demand, and identifies main gaps of current food modelling techniques that affect the accuracy of food demand projections. At the heart of the relationship between income distribution and food demand is Engel's law. Engel's law establishes that as income increases, households' demand for food increases less than proportionally. A consequence of this law is that the particular shape of the distribution of income across individuals and countries affects the rate of growth of food demand. Our review of the literature suggests that existing models of food demand fail to incorporate the required Engel flexibility when (i) aggregating different food budget shares among households; and (ii) changing budget shares as income grows. We perform simple simulations to predict growth in food demand under alternative income distribution scenarios taking into account nonlinearity of food demand. Results suggest that (i) distributional effects are to be expected from changes in between-countries inequality, rather than within-country inequality; and (ii) simulations of an optimistic and a pessimistic scenario of income inequality suggest that world food demand in 2050 would be 2.7 per cent higher and 5.4 per cent lower than distributional-neutral growth, respectively.

  2. Income distribution trends and future food demand

    Science.gov (United States)

    Cirera, Xavier; Masset, Edoardo

    2010-01-01

    This paper surveys the theoretical literature on the relationship between income distribution and food demand, and identifies main gaps of current food modelling techniques that affect the accuracy of food demand projections. At the heart of the relationship between income distribution and food demand is Engel's law. Engel's law establishes that as income increases, households' demand for food increases less than proportionally. A consequence of this law is that the particular shape of the distribution of income across individuals and countries affects the rate of growth of food demand. Our review of the literature suggests that existing models of food demand fail to incorporate the required Engel flexibility when (i) aggregating different food budget shares among households; and (ii) changing budget shares as income grows. We perform simple simulations to predict growth in food demand under alternative income distribution scenarios taking into account nonlinearity of food demand. Results suggest that (i) distributional effects are to be expected from changes in between-countries inequality, rather than within-country inequality; and (ii) simulations of an optimistic and a pessimistic scenario of income inequality suggest that world food demand in 2050 would be 2.7 per cent higher and 5.4 per cent lower than distributional-neutral growth, respectively. PMID:20713387

  3. 煤矿接尘工人职业任务现状调查研究%Current occupational tasks of dust exposed coal miners: a cross-sectional study

    Institute of Scientific and Technical Information of China (English)

    朱婷娟; 郭支喜; 郭红梅; 李秀萍; 王晓成; 高彩虹; 宋平平; 余红梅

    2012-01-01

    目的 探讨煤矿接尘工人职业任务与社会人口学、生活习惯、疾病史、职业因素、工作特征的关系.方法 采用分层整群抽样方法抽取山西省煤矿工人2300名进行一般情况问卷和职业任务量表调查.结果 煤矿工人职业任务的重点人群特征为:年龄>40岁,来自市区,经济状况较差,吸烟,饮酒,身体状况较差,井下工作、接尘时间>6年,工作危险度大,社会地位较低等.结论 煤矿接尘工人面临着较重的职业任务,可制定相应的卫生政策减轻煤矿工人职业任务.%Objective To analyze the correlation between occupational tasks and sociodemographic factors, living habits, disease history, occupational factors and working conditions in dust exposed coal miners. Methods We did a general condition questionnaire and occupational task scale survey on 2300 coal miners via stratified sampling in Shanxi Province. Results The characteristics of occupational task in coal miners included >40 years of age, living in urban areas, poor economic condition, smoking, alcohol drinking, poor physical conditions, working underground, having dust exposure of >6 years, engaging in risky work and lower social status. Conclusion Health policies should be implemented to reduce occupational tasks of coal miner as a result of current challenging burden.

  4. Student reflections on learning with challenging tasks: `I think the worksheets were just for practice, and the challenges were for maths'

    Science.gov (United States)

    Russo, James; Hopkins, Sarah

    2017-09-01

    The current study considered young students' (7 and 8 years old) experiences and perceptions of mathematics lessons involving challenging (i.e. cognitively demanding) tasks. We used the Constant Comparative Method to analyse the interview responses ( n = 73) regarding what work artefacts students were most proud of creating and why. Five themes emerged that characterised student reflections: enjoyment, effort, learning, productivity and meaningful mathematics. Overall, there was evidence that students embraced struggle and persisted when engaged in mathematics lessons involving challenging tasks and, moreover, that many students enjoyed the process of being challenged. In the second section of the paper, the lesson structure preferences of a subset of participants ( n = 23) when learning with challenging tasks are considered. Overall, more students preferred the teach-first lesson structure to the task-first lesson structure, primarily because it activated their cognition to prepare them for work on the challenging task. However, a substantial minority of students (42 %) instead endorsed the task-first lesson structure, with several students explaining they preferred this structure precisely because it was so cognitively demanding. Other reasons for preferring the task-first structure included that it allowed the focus of the lesson to be on the challenging task and the subsequent discussion of student work. A key implication of these combined findings is that, for many students, work on challenging tasks appeared to remain cognitively demanding irrespective of the structure of the lesson.

  5. Student reflections on learning with challenging tasks: `I think the worksheets were just for practice, and the challenges were for maths'

    Science.gov (United States)

    Russo, James; Hopkins, Sarah

    2017-02-01

    The current study considered young students' (7 and 8 years old) experiences and perceptions of mathematics lessons involving challenging (i.e. cognitively demanding) tasks. We used the Constant Comparative Method to analyse the interview responses (n = 73) regarding what work artefacts students were most proud of creating and why. Five themes emerged that characterised student reflections: enjoyment, effort, learning, productivity and meaningful mathematics. Overall, there was evidence that students embraced struggle and persisted when engaged in mathematics lessons involving challenging tasks and, moreover, that many students enjoyed the process of being challenged. In the second section of the paper, the lesson structure preferences of a subset of participants (n = 23) when learning with challenging tasks are considered. Overall, more students preferred the teach-first lesson structure to the task-first lesson structure, primarily because it activated their cognition to prepare them for work on the challenging task. However, a substantial minority of students (42 %) instead endorsed the task-first lesson structure, with several students explaining they preferred this structure precisely because it was so cognitively demanding. Other reasons for preferring the task-first structure included that it allowed the focus of the lesson to be on the challenging task and the subsequent discussion of student work. A key implication of these combined findings is that, for many students, work on challenging tasks appeared to remain cognitively demanding irrespective of the structure of the lesson.

  6. Evidence that a transient but cognitively demanding process underlies forward blocking.

    Science.gov (United States)

    Liu, Pei-Pei; Luhmann, Christian C

    2013-01-01

    Blocking is a learning phenomenon in which prior experience inhibits learning about novel cues. Though the phenomenon itself has been well documented, the details of blocking-related processes still remain contentious. Two experiments investigated whether participants were engaged in demanding cognitive processing during different portions of a standard blocking paradigm. Participants in Experiment 1 engaged in a simple secondary task while completing a standard blocking procedure. Results showed that performance on the secondary task was briefly diminished early in the second phase of the blocking paradigm, when the novel cue is first paired with the pretrained cue. Participants in Experiment 2 performed a difficult cognitive load task during either the early or the late portions of the second phase of blocking. The blocking effect was eliminated when learners were under load early in the second phase, but not when learners were under load late in the second phase. These results suggest that blocking relies on a cognitively demanding process with a distinct time course. Computational simulations illustrate how a model that includes top-down (i.e., cognitively demanding) attentional modulation can reproduce the observed behaviour. This suggests that purely associative processes are not sufficient to explain the observed behaviour. Implications for current accounts of blocking are discussed.

  7. Current status and recommendations for the future of research, teaching, and testing in the biological sciences of radiation oncology: report of the American Society for Radiation Oncology Cancer Biology/Radiation Biology Task Force, executive summary.

    Science.gov (United States)

    Wallner, Paul E; Anscher, Mitchell S; Barker, Christopher A; Bassetti, Michael; Bristow, Robert G; Cha, Yong I; Dicker, Adam P; Formenti, Silvia C; Graves, Edward E; Hahn, Stephen M; Hei, Tom K; Kimmelman, Alec C; Kirsch, David G; Kozak, Kevin R; Lawrence, Theodore S; Marples, Brian; McBride, William H; Mikkelsen, Ross B; Park, Catherine C; Weidhaas, Joanne B; Zietman, Anthony L; Steinberg, Michael

    2014-01-01

    In early 2011, a dialogue was initiated within the Board of Directors (BOD) of the American Society for Radiation Oncology (ASTRO) regarding the future of the basic sciences of the specialty, primarily focused on the current state and potential future direction of basic research within radiation oncology. After consideration of the complexity of the issues involved and the precise nature of the undertaking, in August 2011, the BOD empanelled a Cancer Biology/Radiation Biology Task Force (TF). The TF was charged with developing an accurate snapshot of the current state of basic (preclinical) research in radiation oncology from the perspective of relevance to the modern clinical practice of radiation oncology as well as the education of our trainees and attending physicians in the biological sciences. The TF was further charged with making suggestions as to critical areas of biological basic research investigation that might be most likely to maintain and build further the scientific foundation and vitality of radiation oncology as an independent and vibrant medical specialty. It was not within the scope of service of the TF to consider the quality of ongoing research efforts within the broader radiation oncology space, to presume to consider their future potential, or to discourage in any way the investigators committed to areas of interest other than those targeted. The TF charge specifically precluded consideration of research issues related to technology, physics, or clinical investigations. This document represents an Executive Summary of the Task Force report.

  8. Current Status and Recommendations for the Future of Research, Teaching, and Testing in the Biological Sciences of Radiation Oncology: Report of the American Society for Radiation Oncology Cancer Biology/Radiation Biology Task Force, Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Wallner, Paul E., E-mail: pwallner@theabr.org [21st Century Oncology, LLC, and the American Board of Radiology, Bethesda, Maryland (United States); Anscher, Mitchell S. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Barker, Christopher A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Bassetti, Michael [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, Madison, Wisconsin (United States); Bristow, Robert G. [Departments of Radiation Oncology and Medical Biophysics, Princess Margaret Cancer Center/University of Toronto, Toronto, Ontario (Canada); Cha, Yong I. [Department of Radiation Oncology, Norton Cancer Center, Louisville, Kentucky (United States); Dicker, Adam P. [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Formenti, Silvia C. [Department of Radiation Oncology, New York University, New York, New York (United States); Graves, Edward E. [Departments of Radiation Oncology and Radiology, Stanford University, Stanford, California (United States); Hahn, Stephen M. [Department of Radiation Oncology, University of Pennsylvania (United States); Hei, Tom K. [Center for Radiation Research, Columbia University, New York, New York (United States); Kimmelman, Alec C. [Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Kirsch, David G. [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Kozak, Kevin R. [Department of Human Oncology, University of Wisconsin (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan (United States); Marples, Brian [Department of Radiation Oncology, Oakland University, Oakland, California (United States); and others

    2014-01-01

    In early 2011, a dialogue was initiated within the Board of Directors (BOD) of the American Society for Radiation Oncology (ASTRO) regarding the future of the basic sciences of the specialty, primarily focused on the current state and potential future direction of basic research within radiation oncology. After consideration of the complexity of the issues involved and the precise nature of the undertaking, in August 2011, the BOD empanelled a Cancer Biology/Radiation Biology Task Force (TF). The TF was charged with developing an accurate snapshot of the current state of basic (preclinical) research in radiation oncology from the perspective of relevance to the modern clinical practice of radiation oncology as well as the education of our trainees and attending physicians in the biological sciences. The TF was further charged with making suggestions as to critical areas of biological basic research investigation that might be most likely to maintain and build further the scientific foundation and vitality of radiation oncology as an independent and vibrant medical specialty. It was not within the scope of service of the TF to consider the quality of ongoing research efforts within the broader radiation oncology space, to presume to consider their future potential, or to discourage in any way the investigators committed to areas of interest other than those targeted. The TF charge specifically precluded consideration of research issues related to technology, physics, or clinical investigations. This document represents an Executive Summary of the Task Force report.

  9. Task Dominance Determines Backward Inhibition in Task Switching

    Directory of Open Access Journals (Sweden)

    Kerstin Jost

    2017-05-01

    Full Text Available Switching between tasks is assumed to be accompanied by inhibiting currently irrelevant, but competing tasks. A dominant task that strongly interferes with performing a weaker task may receive especially strong inhibition. We tested this prediction by letting participants switch among three tasks that differ in dominance: a location discrimination task with strong stimulus–response bindings (responding with left-hand and right-hand button presses to stimuli presented left or right to the fixation cross was combined with a color/pattern and a shape discrimination task, for which stimulus–response mappings were arbitrary (e.g., left-hand button press mapped to a red stimulus. Across three experiments, the dominance of the location task was documented by faster and more accurate responses than in the other tasks. This even held for incompatible stimulus–response mappings (i.e., right-hand response to a left-presented stimulus and vice versa, indicating that set-level compatibility (i.e., “dimension overlap” was sufficient for making this location task dominant. As a behavioral marker for backward inhibition, we utilized n-2 repetition costs that are defined by higher reaction times for a switch back to a just abandoned and thus just inhibited task (ABA sequence than for a switch to a less recently inhibited task (CBA, n-2 non-repetition. Reliable n-2 task repetition costs were obtained for all three tasks. Importantly, these costs were largest for the location task, suggesting that inhibition indeed was stronger for the dominant task. This finding adds to other evidence that the amount of inhibition is adjusted in a context-sensitive way.

  10. Uranium 2009 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris

    2010-01-01

    With several countries currently building nuclear power plants and planning the construction of more to meet long-term increases in electricity demand, uranium resources, production and demand remain topics of notable interest. In response to the projected growth in demand for uranium and declining inventories, the uranium industry – the first critical link in the fuel supply chain for nuclear reactors – is boosting production and developing plans for further increases in the near future. Strong market conditions will, however, be necessary to trigger the investments required to meet projected demand. The "Red Book", jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, is a recognised world reference on uranium. It is based on information compiled in 40 countries, including those that are major producers and consumers of uranium. This 23rd edition provides a comprehensive review of world uranium supply and demand as of 1 January 2009, as well as data on global ur...

  11. Research on the Demand Characteristics,Current Situation and Development Strategy of Urban Distribution in China%我国城市配送形势分析及发展策略

    Institute of Scientific and Technical Information of China (English)

    温卫娟; 邬跃

    2014-01-01

    distribution demand and the current situation of that,give priority to the promotion of urban joint distribution,encourage the enterprises in business circles to distribute at night, promote the rapid development of community distribution,invest more in the development of e-business distribution,and standardize special distribution involved in people’s livelihood.

  12. The Current Situation of Dual Referral and Demand of the Patients in Community Health Service of Beijing%北京市社区双向转诊现状及患者需求分析

    Institute of Scientific and Technical Information of China (English)

    王辉; 季和平; 孙滨

    2011-01-01

    目的 了解北京市社区双向转诊的现状,分析患者在双向转诊中的需求,为政策的制定和管理的决策提供依据.方法 随机抽取北京市某社区年龄≥18岁的居民2 183名,采用问卷进行调查,对资料进行统计描述分析.结果 (1)居民患病后有53.09%表示会优先选择社区卫生服务机构就诊.(2)社区卫生服务机构的上转患者中由于社区医生的水平有限所致的上转率为48.05%,转诊形式为口头转诊,社区上转的患者中仅有5.20%持单转回社区.(3)有4.35%的居民由二、三级医院下转至社区,全部为口头转诊.(4)82.09%的居民表示愿意在疾病的稳定期或康复期下转社区卫生服务机构,有11.91%的居民不愿意下转社区卫生服务机构主要原因是费用不能报销;居民期待自由式转诊率为65.69%.讨论 (1)亟待提高社区医务人员的业务能力.(2)目前不论上转还是下转都以口头转诊为主,持单转诊尚需政策支持.(3)实行"多对多"的转诊,建立全市双向转诊平台.%Objective To investigate the current situation of two - way referral hetween class 2 or 3 hospitals and the subordinate community health service institutions and to analyze the demand of the patients during the referral in order to provide relevant evidence for the policy constitution and strategy decision. Methods Data of 2 183 residents aged 18 or more from a community randomly enrolled from Beijing city were collected by questionnaire survey and analyzed statistically. Results A total of 53.09% of the residents preferred community health institutions when in need of seeing a doctor. 48.05 % of the up - referrals were due to the limited capability of community doctors. Most of the up - referrals were oral, and 5.20% of the up - referrals were referred back to the community with down - referral certifications. Only 4.35% interviewees were down - referred from class 2 or 3 hospitals to the community, and none of them had down

  13. [Utilization of Multi-Institutional Laboratory Data as an Evidence Database: The Current Status and Future Tasks--Chairmen's Introductory Remarks].

    Science.gov (United States)

    Miyake, Kazunori; Nishibori, Masahiro

    2015-01-01

    The construction of a database that integrates raw laboratory data and diagnostic information with patient backgrounds is an effective tool in the practice of Evidence-Based Laboratory Medicine (EBLM). By exploring this type of database, it is possible to understand the diagnostic characteristics of the tests for a specific patient subgroup or condition. Although several studies have been carried out recently, these databases contain single-hospital data, and are thus limited regarding their external validity. In order to improve the reliability of the evidence, joint multi-institutional research is required. Therefore, the EBLM Committee of the Japanese Society of Clinical Laboratory Medicine arranged the symposium, entitled: "Utilization of multi-institutional laboratory data as an evidence database", which discusses current problems and solutions for the integration of multi-institutional laboratory data. In the symposium, five speakers presented on the following subjects: 1) Standardization of laboratory test coding (JLAC10); 2) The construction of a data warehouse in the hospital; 3) Multi-institutional study on long-term data changes; 4) Multi-institutional study on diagnostic accuracy; and 5) The construction of databases for the practice of EBLM and the need for the standardization/harmonization of laboratory data.

  14. Demand sensing in e-business

    Indian Academy of Sciences (India)

    K Ravikumar; Atul Saroop; H K Narahari; Pankaj Dayama

    2005-04-01

    In this paper, we identify various models from the optimization and econometrics literature that can potentially help sense customer demand in the e-business era. While modelling reality is a difficult task, many of these models come close to modelling the customer’s decision-making process. We provide a brief overview of these techniques, interspersing the discussion occasionally with a tutorial introduction of the underlying concepts.

  15. Examining depletion theories under conditions of within-task transfer.

    Science.gov (United States)

    Brewer, Gene A; Lau, Kevin K H; Wingert, Kimberly M; Ball, B Hunter; Blais, Chris

    2017-07-01

    In everyday life, mental fatigue can be detrimental across many domains including driving, learning, and working. Given the importance of understanding and accounting for the deleterious effects of mental fatigue on behavior, a growing body of literature has studied the role of motivational and executive control processes in mental fatigue. In typical laboratory paradigms, participants complete a task that places demand on these self-control processes and are later given a subsequent task. Generally speaking, decrements to subsequent task performance are taken as evidence that the initial task created mental fatigue through the continued engagement of motivational and executive functions. Several models have been developed to account for negative transfer resulting from this "ego depletion." In the current study, we provide a brief literature review, specify current theoretical approaches to ego-depletion, and report an empirical test of current models of depletion. Across 4 experiments we found minimal evidence for executive control depletion along with strong evidence for motivation mediated ego depletion. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. The Workforce Task Force report: clinical implications for neurology.

    Science.gov (United States)

    Freeman, William D; Vatz, Kenneth A; Griggs, Robert C; Pedley, Timothy

    2013-07-30

    The American Academy of Neurology Workforce Task Force (WFTF) report predicts a future shortfall of neurologists in the United States. The WFTF data also suggest that for most states, the current demand for neurologist services already exceeds the supply, and by 2025 the demand for neurologists will be even higher. This future demand is fueled by the aging of the US population, the higher health care utilization rates of neurologic services, and by a greater number of patients gaining access to the health care system due to the Patient Protection and Affordable Care Act. Uncertainties in health care delivery and patient access exist due to looming concerns about further Medicare reimbursement cuts. This uncertainty is set against a backdrop of Congressional volatility on a variety of issues, including the repeal of the sustainable growth rate for physician reimbursement. The impact of these US health care changes on the neurology workforce, future increasing demands, reimbursement, and alternative health care delivery models including accountable care organizations, nonphysician providers such as nurse practitioners and physician assistants, and teleneurology for both stroke and general neurology are discussed. The data lead to the conclusion that neurologists will need to play an even larger role in caring for the aging US population by 2025. We propose solutions to increase the availability of neurologic services in the future and provide other ways of meeting the anticipated increased demand for neurologic care.

  17. Demand chain management - The evolution

    Directory of Open Access Journals (Sweden)

    D Ericsson

    2011-06-01

    Full Text Available The concepts of Supply Chain Management (SCM and Demand Chain Management (DCM are among the new and debated topics concerning logistics in the literature. The question considered in this paper is: “Are these concepts needed or will they just add to the confusion?” Lasting business concepts have always evolved in close interaction between business and academia. Different approaches start out in business and they are then, more or less si- multaneously, aligned, integrated, systemised and structured in academia. In this way a terminology (or language is provided that helps in further diffusion of the concepts. There is a lack of consensus on the definition of the concept of SCM. This may be one of the major reasons for the difficulty in advancing the science and measuring the results of implementation in business. Relationships in SCM span from rather loose coalitions to highly structured virtual network integrations. DCM is a highly organised chain in which the key is mutual interdependence and partnership. The purpose is to create a distinctive competence for the chain as a whole that helps to identify and satisfy customer needs and wishes. The classical research concerning vertical marketing systems is very helpful in systemising the rather unstructured discussions in current SCM research. The trend lies in increasing competition between channels rather than between companies, which in turn leads to the creation of channels with a high degree of partnership and mutual interdependence between members. These types of channels are known as organised vertical marketing systems in the classic marketing channel research. The behaviour in these types of channels, as well as the formal and informal structures, roles in the network, power and dependence relations, etc. are well covered topics in the literature. The concept of vertical marketing systems lies behind the definition of demand chains and demand chain management proposed in this paper. A

  18. Travel Demand Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, Frank [ORNL; Garrow, Dr. Laurie [Georgia Institute of Technology

    2011-01-01

    This chapter describes the principal types of both passenger and freight demand models in use today, providing a brief history of model development supported by references to a number of popular texts on the subject, and directing the reader to papers covering some of the more recent technical developments in the area. Over the past half century a variety of methods have been used to estimate and forecast travel demands, drawing concepts from economic/utility maximization theory, transportation system optimization and spatial interaction theory, using and often combining solution techniques as varied as Box-Jenkins methods, non-linear multivariate regression, non-linear mathematical programming, and agent-based microsimulation.

  19. Education on Demand

    DEFF Research Database (Denmark)

    Boysen, Lis; Hende, Merete

    2015-01-01

    Dette notat beskriver nogle af resultaterne fra programmet "Education on Demand' i projektet Det erhvervsrettede Uddannelseslaboratorium. Programmet har haft fokus på udfordringer og forandringsbehov i uddannelsesinstitutioner og -systemet. Herunder har det beskæftiget sig særligt med de to temat......Dette notat beskriver nogle af resultaterne fra programmet "Education on Demand' i projektet Det erhvervsrettede Uddannelseslaboratorium. Programmet har haft fokus på udfordringer og forandringsbehov i uddannelsesinstitutioner og -systemet. Herunder har det beskæftiget sig særligt med de...

  20. Demand Modelling in Telecommunications

    Directory of Open Access Journals (Sweden)

    M. Chvalina

    2009-01-01

    Full Text Available This article analyses the existing possibilities for using Standard Statistical Methods and Artificial Intelligence Methods for a short-term forecast and simulation of demand in the field of telecommunications. The most widespread methods are based on Time Series Analysis. Nowadays, approaches based on Artificial Intelligence Methods, including Neural Networks, are booming. Separate approaches will be used in the study of Demand Modelling in Telecommunications, and the results of these models will be compared with actual guaranteed values. Then we will examine the quality of Neural Network models. 

  1. Analysis of physical demands during bulk bag closing and sealing.

    Science.gov (United States)

    Nasarwanji, Mahiyar F; Reardon, Leanna M; Heberger, John R; Dempsey, Patrick G

    2016-05-01

    Several tools are sold and recommended for closing and sealing flexible intermediate bulk containers (bulk bags) which are used to transport product that has been mined and processed. However, there is limited information on the risks, physical demands, or the benefits of using one tool over another. The purpose of this study was to evaluate the physical demands involved with two closing methods and several sealing tools in order to provide recommendations for selecting tools to reduce exposure to risk factors for work-related musculoskeletal disorders. In this study, twelve participants completed bag closing and sealing tasks using two different closing methods and eight sealing tools on two types of bulk bags. Physical demands and performance were evaluated using muscle activity, perceived exertion, subjective ratings of use, and time. Results indicate that using the "flowering" method to close bags required on average 32% less muscle activity, 30% less perceived exertion, 42% less time, and was preferred by participants compared to using the "snaking" method. For sealing, there was no single method significantly better across all measures; however, using a pneumatic cable tie gun consistently had the lowest muscle activity and perceived exertion ratings. The pneumatic cable tie gun did require approximately 33% more time to seal the bag compared to methods without a tool, but the amount of time to seal the bag was comparable to using other tools. Further, sealing a spout bulk bag required on average 13% less muscle activity, 18% less perceived exertion, 35% less time, and was preferred by participants compared to sealing a duffle bulk bag. The current results suggest that closing the spout bag using the flowering method and sealing the bag using the pneumatic cable tie gun that is installed with a tool balancer is ergonomically advantageous. Our findings can help organizations select methods and tools that pose the lowest physical demands when closing and

  2. Nursing supply and demand: reviewing the evidence.

    Science.gov (United States)

    Buchan, J; O'May, F

    This paper reviews research on the supply of, and demand for nurse. It examines the utility of various data indicators of nursing shortages and highlights potential shortcomings in their application. The paper also assesses the links between nurses' pay and nurses' labour market behaviour, reviewing the comparatively few papers that have taken a UK perspective on this issue. The current mismatch between nurses' supply and demand in the UK is also examined, with the clear indication that there is potential for an increase in mismatch as demand increases, while future supply appears problematic.

  3. Control and Interference in Task Switching--A Review

    Science.gov (United States)

    Kiesel, Andrea; Steinhauser, Marco; Wendt, Mike; Falkenstein, Michael; Jost, Kerstin; Philipp, Andrea M.; Koch, Iring

    2010-01-01

    The task-switching paradigm offers enormous possibilities to study cognitive control as well as task interference. The current review provides an overview of recent research on both topics. First, we review different experimental approaches to task switching, such as comparing mixed-task blocks with single-task blocks, predictable task-switching…

  4. Oil supply and demand

    Energy Technology Data Exchange (ETDEWEB)

    Rech, O

    2004-07-01

    World oil demand, driven by economic development in China, posted the highest growth rate in 20 years. In a context of geopolitical uncertainty, prices are soaring, encouraged by low inventory and the low availability of residual production capacity. Will 2004 bring a change in the oil market paradigm? (author)

  5. The demand for euros

    NARCIS (Netherlands)

    Arnold, I.J.M.; Roelands, S.

    2010-01-01

    This paper investigates the demand for euros using panel data for 10 euro area countries covering the period from 1999 to 2008. Monetary aggregates are constructed to ensure that money is a national concept by excluding deposits owned by non-residents and including external deposits owned by

  6. DEMAND AND PRICES

    Directory of Open Access Journals (Sweden)

    VĂDUVA MARIA

    2014-08-01

    Full Text Available Studying the consumer’s behavior by the ordinal approach of utility with the help of indifference curves allows us to deduce the two “movement laws of demand” in this chapter: the demand for a “normal” good is decreasing function of its price and an increasing function of income. We will use the elasticity concept to measure the intensity of the relation that is established between the demand, on the one hand, and prices or income, on the other hand: elasticity – price, direct and crossed, and elasticity – income. We can classify the goods in many categories, depending on the values that this elasticity takes. The demand elasticity can be determined depending on price and income. It reflects the proportion in which the demand for different products changes with the modification of the consumers’ income, the other factors remaining constant. The elasticity compared to the income is a demonstration of legality from the consumer’s sphere, which determines a certain hierarchy of the needs of each population category in a certain level of income. The movement of prices orients both the options and decisions of producers, namely the most useful productions and the most efficient investments, as well as the consumers’ options and decisions on the most advantageous buying of goods and services that they need. The prices appear as a “signal system” coordinating and making coherence the economic agents’ decisions – producers, consumers and population.

  7. Demand Response Resource Quantification with Detailed Building Energy Models

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Elaine; Horsey, Henry; Merket, Noel; Stoll, Brady; Nag, Ambarish

    2017-04-03

    Demand response is a broad suite of technologies that enables changes in electrical load operations in support of power system reliability and efficiency. Although demand response is not a new concept, there is new appetite for comprehensively evaluating its technical potential in the context of renewable energy integration. The complexity of demand response makes this task difficult -- we present new methods for capturing the heterogeneity of potential responses from buildings, their time-varying nature, and metrics such as thermal comfort that help quantify likely acceptability of specific demand response actions. Computed with an automated software framework, the methods are scalable.

  8. Categorization Is Modulated by Transcranial Direct Current Stimulation over Left Prefrontal Cortex

    Science.gov (United States)

    Lupyan, Gary; Mirman, Daniel; Hamilton, Roy; Thompson-Schill, Sharon L.

    2012-01-01

    Humans have an unparalleled ability to represent objects as members of multiple categories. A given object, such as a pillow may be--depending on current task demands--represented as an instance of something that is soft, as something that contains feathers, as something that is found in bedrooms, or something that is larger than a toaster. This…

  9. The Current China's Macroeconomic Total Demand and Monetary Policy Regulation and Control%当前中国宏观经济总需求及货币政策调控

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    From the angle of the contribution to economic growth of China's three major demands,domestic demand is the potential power of China's economic growth,while external demand has made important contributions.Regulation and control of monetary policy on aggregate demand is conduct through the credit channel and the interest rate channel.However,because of the micro-subject of China's market is not sensitive to interest rate signals,the interest rate pathways is limited.The condition of monetary policy interest rates conducting effectively is that the micro-subject can make their own decision based on monetary policy freely and can obtain benefi ts or bear the loss for their choice.Therefore,to improve the effect of monetary policy,we should consolidate the market micro-foundation and establish a sound market competition mechanism.%从我国三大需求对经济增长的贡献看,内需是中国经济增长的主要动力源,外需为中国经济发展做出了重要贡献。货币政策对总需求的调控主要通过信贷渠道和利率渠道进行传导,但由于我国市场微观主体对利率信号不敏感,利率传导途径受到限制。货币政策利率传导途径有效的前提是微观主体根据货币政策做出决策后须有条件实现自己的选择,并因自己的行为获取利益或承担损失,这样才能建立起传递及时、反应敏感的传导机制,更好实现货币政策的调控目标。因此,要提高货币政策效应,应更多从夯实市场微观基础、健全市场竞争机制等方面来考虑。

  10. Musical expertise has minimal impact on dual task performance

    OpenAIRE

    Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea

    2017-01-01

    Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organization of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. \\ud \\ud Our study compared...

  11. U.S. Preventive Services Task Force

    Science.gov (United States)

    ... Public Comment In an effort to make the U.S. Preventive Services Task Force (USPSTF) recommendations clearer and ... Current as of: May 2016 Internet Citation: Home . U.S. Preventive Services Task Force. August 2016. https://www. ...

  12. Decision Making and the Avoidance of Cognitive Demand

    Science.gov (United States)

    Kool, Wouter; McGuire, Joseph T.; Rosen, Zev B.; Botvinick, Matthew M.

    2010-01-01

    Behavioral and economic theories have long maintained that actions are chosen so as to minimize demands for exertion or work, a principle sometimes referred to as the “law of less work.” The data supporting this idea pertain almost entirely to demands for physical effort. However, the same minimization principle has often been assumed also to apply to cognitive demand. We set out to evaluate the validity of this assumption. In six behavioral experiments, participants chose freely between courses of action associated with different levels of demand for controlled information processing. Together, the results of these experiments revealed a bias in favor of the less demanding course of action. The bias was obtained across a range of choice settings and demand manipulations, and was not wholly attributable to strategic avoidance of errors, minimization of time on task, or maximization of the rate of goal achievement. Remarkably, the effect also did not depend on awareness of the demand manipulation. Consistent with a motivational account, avoidance of demand displayed sensitivity to task incentives and co-varied with individual differences in the efficacy of executive control. The findings reported, together with convergent neuroscientific evidence, lend support to the idea that anticipated cognitive demand plays a significant role in behavioral decision-making. PMID:20853993

  13. Student Reflections on Learning with Challenging Tasks: "I Think the Worksheets Were Just for Practice, and the Challenges Were for Maths"

    Science.gov (United States)

    Russo, James; Hopkins, Sarah

    2017-01-01

    The current study considered young students' (7 and 8 years old) experiences and perceptions of mathematics lessons involving challenging (i.e. cognitively demanding) tasks. We used the Constant Comparative Method to analyse the interview responses (n = 73) regarding what work artefacts students were most proud of creating and why. Five themes…

  14. Avoiding the conflict: Metacognitive awareness drives the selection of low-demand contexts.

    Science.gov (United States)

    Desender, Kobe; Buc Calderon, Cristian; Van Opstal, Filip; Van den Bussche, Eva

    2017-07-01

    Previous research attempted to explain how humans strategically adapt behavior in order to achieve successful task performance. Recently, it has been suggested that 1 potential strategy is to avoid tasks that are too demanding. Here, we report 3 experiments that investigate the empirically neglected role of metacognitive awareness in this process. In these experiments, participants could freely choose between performing a task in either a high-demand or a low-demand context. Using subliminal priming, we ensured that participants were not aware of the visual stimuli creating these different demand contexts. Our results showed that participants who noticed a difference in task difficulty (i.e., metacognitive aware participants) developed a clear preference for the low-demand context. In contrast, participants who experienced no difference in task difficulty (i.e., metacognitive unaware participants) based their choices on variables unrelated to cognitive demand (e.g., the color or location associated with a context), and did not develop a preference for the low-demand context. Crucially, this pattern was found despite identical task performance in both metacognitive awareness groups. A multiple regression approach confirmed that metacognitive awareness was the main factor driving the preference for low-demand contexts. These results argue for an important role of metacognitive awareness in the strategic avoidance of demanding tasks. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Demand surge following earthquakes

    Science.gov (United States)

    Olsen, Anna H.

    2012-01-01

    Demand surge is understood to be a socio-economic phenomenon where repair costs for the same damage are higher after large- versus small-scale natural disasters. It has reportedly increased monetary losses by 20 to 50%. In previous work, a model for the increased costs of reconstruction labor and materials was developed for hurricanes in the Southeast United States. The model showed that labor cost increases, rather than the material component, drove the total repair cost increases, and this finding could be extended to earthquakes. A study of past large-scale disasters suggested that there may be additional explanations for demand surge. Two such explanations specific to earthquakes are the exclusion of insurance coverage for earthquake damage and possible concurrent causation of damage from an earthquake followed by fire or tsunami. Additional research into these aspects might provide a better explanation for increased monetary losses after large- vs. small-scale earthquakes.

  16. Market Expects Demand Increase

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In the recent releasing Textile Industry Invigorating Plan,"givingattention to both domestlc and overseas markets"is put into a keyposition.Under a series policies,such as increasing the tax rebaterate for textile and garment exports,and granting loan for SME,thefurther development of this industry is expectative.Otherwise,weshould know that it costs time for demand driving.This need ourpatients.The only questionis how much time we have to wait.

  17. Migration and Tourism Demand

    Directory of Open Access Journals (Sweden)

    Nuno Carlos LEITÃO

    2012-02-01

    Full Text Available This study considers the relationship between immigration and Portuguese tourism demand for the period 1995-2008, using a dynamic panel data approach. The findings indicate that Portuguese tourism increased significantly during the period in accordance with the values expected for a developed country. The regression results show that income, shock of immigration, population, and geographical distance between Portugal and countries of origin are the main determinants of Portuguese tourism.

  18. Demand for human allograft tissue in Canada.

    Science.gov (United States)

    Lakey, Jonathan R T; Mirbolooki, Mohammadreza; Rogers, Christina; Mohr, Jim

    2007-01-01

    There is relatively little known about the demand for allograft tissues in Canada. The Canadian Council for Donation and Transplantation (CCDT) is a national advisory body that undertook a comprehensive "market survey" to estimate surgical demand for human allograft tissues in Canada. The report "Demand for Human Allograft Tissue in Canada" reflects survey results sent to 5 prominent User Groups. User Groups were identified as orthopaedic surgeons; neurosurgeons; corneal transplant surgeons; plastic surgeons, specifically those at Canadian Burn Units; and cardiac surgeons (adult and paediatric surgery). The demand for allograft grafts was determined and then extrapolated across the total User Group and then increases in allograft tissue use over the next 1-2 years across User Groups were predicted. The overall response rate for the survey was 21.4%. It varied from a low of 19.6% for the orthopaedic survey to a high of 40.5% for the corneal survey. The estimated current demand for allograft tissue in Canada ranges from a low of 34,442 grafts per year to a high of 62,098 grafts per year. The predicted increase in use of allograft tissue over the next 1-2 year period would suggest that annual demand could rise to somewhere in the range of 42,589-72,210 grafts. The highest rated preferences (98% and 94%) were for accredited and Canadian tissue banks, respectively. This study represents a key step in addressing the paucity of information concerning the demand for allograft tissue in Canada.

  19. Reward Sensitivity Modulates Brain Activity in the Prefrontal Cortex, ACC and Striatum during Task Switching

    Science.gov (United States)

    Fuentes-Claramonte, Paola; Ávila, César; Rodríguez-Pujadas, Aina; Ventura-Campos, Noelia; Bustamante, Juan C.; Costumero, Víctor; Rosell-Negre, Patricia; Barrós-Loscertales, Alfonso

    2015-01-01

    Current perspectives on cognitive control acknowledge that individual differences in motivational dispositions may modulate cognitive processes in the absence of reward contingencies. This work aimed to study the relationship between individual differences in Behavioral Activation System (BAS) sensitivity and the neural underpinnings involved in processing a switching cue in a task-switching paradigm. BAS sensitivity was hypothesized to modulate brain activity in frontal regions, ACC and the striatum. Twenty-eight healthy participants underwent fMRI while performing a switching task, which elicited activity in fronto-striatal regions during the processing of the switch cue. BAS sensitivity was negatively associated with activity in the lateral prefrontal cortex, anterior cingulate cortex and the ventral striatum. Combined with previous results, our data indicate that BAS sensitivity modulates the neurocognitive processes involved in task switching in a complex manner depending on task demands. Therefore, individual differences in motivational dispositions may influence cognitive processing in the absence of reward contingencies. PMID:25875640

  20. Application of a COTS Resource Optimization Framework to the SSN Sensor Tasking Domain - Part I: Problem Definition

    Science.gov (United States)

    Tran, T.

    With the onset of the SmallSat era, the RSO catalog is expected to see continuing growth in the near future. This presents a significant challenge to the current sensor tasking of the SSN. The Air Force is in need of a sensor tasking system that is robust, efficient, scalable, and able to respond in real-time to interruptive events that can change the tracking requirements of the RSOs. Furthermore, the system must be capable of using processed data from heterogeneous sensors to improve tasking efficiency. The SSN sensor tasking can be regarded as an economic problem of supply and demand: the amount of tracking data needed by each RSO represents the demand side while the SSN sensor tasking represents the supply side. As the number of RSOs to be tracked grows, demand exceeds supply. The decision-maker is faced with the problem of how to allocate resources in the most efficient manner. Braxton recently developed a framework called Multi-Objective Resource Optimization using Genetic Algorithm (MOROUGA) as one of its modern COTS software products. This optimization framework took advantage of the maturing technology of evolutionary computation in the last 15 years. This framework was applied successfully to address the resource allocation of an AFSCN-like problem. In any resource allocation problem, there are five key elements: (1) the resource pool, (2) the tasks using the resources, (3) a set of constraints on the tasks and the resources, (4) the objective functions to be optimized, and (5) the demand levied on the resources. In this paper we explain in detail how the design features of this optimization framework are directly applicable to address the SSN sensor tasking domain. We also discuss our validation effort as well as present the result of the AFSCN resource allocation domain using a prototype based on this optimization framework.

  1. Putting Tasks to the Test: Human Capital, Job Tasks and Wages. NBER Working Paper No. 15116

    Science.gov (United States)

    Autor, David H.; Handel, Michael J.

    2009-01-01

    Employing original, representative survey data, we document that cognitive, interpersonal and physical job task demands can be measured with high validity using standard interview techniques. Job tasks vary substantially within and between occupations, are significantly related to workers' characteristics, and are robustly predictive of wage…

  2. Assessing Cognitive Load on Web Search Tasks

    CERN Document Server

    Gwizdka, Jacek

    2010-01-01

    Assessing cognitive load on web search is useful for characterizing search system features and search tasks with respect to their demands on the searcher's mental effort. It is also helpful for examining how individual differences among searchers (e.g. cognitive abilities) affect the search process. We examined cognitive load from the perspective of primary and secondary task performance. A controlled web search study was conducted with 48 participants. The primary task performance components were found to be significantly related to both the objective and the subjective task difficulty. However, the relationship between objective and subjective task difficulty and the secondary task performance measures was weaker than expected. The results indicate that the dual-task approach needs to be used with caution.

  3. Attentional Focus Effects as a Function of Task Difficulty

    Science.gov (United States)

    Wulf, Gabriele; Tollner, Thomas; Shea, Charles H.

    2007-01-01

    The purpose of the present study was to examine whether the advantages of adopting an external focus would be seen primarily for relatively challenging (postural stability) tasks but not less demanding tasks. To examine this, the authors used balance tasks that imposed increased challenges to maintaining stability. The present results support the…

  4. Tobacco demand, delay discounting, and smoking topography among smokers with and without psychopathology.

    Science.gov (United States)

    Farris, Samantha G; Aston, Elizabeth R; Abrantes, Ana M; Zvolensky, Michael J

    2017-10-01

    Tobacco demand (i.e., relative value attributed to a given reinforcer) and delay discounting (i.e., relative preference for smaller immediate rewards over larger delayed rewards) are two behavioral economic processes that are linked to the progression of problematic substance use. These processes have not been studied among those with psychopathology, a vulnerable group of smokers. The current study examined differences in tobacco demand and delay discounting, and their association with smoking topography among smokers with (n=43) and without (n=64) past-year psychopathology. Adult daily smokers (n=107,Mage=43.5; SD=9.7) participated in a study on "smoking behavior." Past-year psychological disorders were assessed via a clinician-administered diagnostic assessment. All subjects participated in an ad libitum smoking trial and then completed an assessment of delay discounting (Monetary Choice Questionnaire) and tobacco demand (Cigarette Purchase Task) approximately 45-60min post-smoking. Smokers with psychopathology, compared to those without, had significantly higher demand intensity and maximum expenditure on tobacco (Omax), but did not differ on other demand indices or delay discounting. Smokers with psychopathology had shorter average inter-puff intervals and shorter time to cigarette completion than smokers without psychopathology. Tobacco demand and delay discounting measures were significantly intercorrelated among smokers with psychopathology, but not those without. Both behavioral economic measures were associated with specific aspects of smoking topography in smokers with psychopathology. The association between tobacco demand and delay discounting is evident among smokers with psychopathology and both measures were most consistently related to smoking behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Investigating the Effects of Assembly Order on the Performance in Relation to Cognitive and Physical Demands Under Takt Time

    Directory of Open Access Journals (Sweden)

    Shakeel Ahmed Shaikh

    2014-10-01

    Full Text Available Assembly line operations generally involve physical and cognitive demanding tasks. Simultaneous performance under physical and cognitive demanding tasks may create physical and mental stresses. A within subjects study was carried out to determine the effects of assembly levels (variable assembly and consistent assembly on working conditions. Nine participants participated in a study and performed 8 conditions. The objective of the study was to determine the relation between physical and cognitive demands in a simulated task involving simultaneous performance of physical (fastening nuts and bolts and cognitive (code matching with secondary task of memorizing the code demanding task. Results showed the significant effects of assembly order (consisted of the concurrent performance of physically and cognitively demanding task on the working conditions. Quality of performance was affected by variable assembly order, high mental demand and above shoulder height

  6. Identifying of risks in pricing using a regression model of demand on price dependence

    Directory of Open Access Journals (Sweden)

    O.I. Yashkina

    2016-09-01

    Full Text Available The aim of the article. The main purpose of the article is to describe scientific and methodological approaches of determining the price elasticity of demand as a regression model based on the price and risk assessment of price variations on the received model. The results of the analysis. The study is based on the assumption that the index of price elasticity of demand on high-tech innovation is not constant as it is commonly understood in the classical sense. On the stage of commodity market release and subsequent sales growth, the index of price elasticity of demand may vary within certain limits. Index value and thereafter market response are closely related to the current price. Achieving the stated purpose of the article is possible when having factual information about prices and corresponding volumes of sales of new high-tech products for a short period of time, on the basis of which types of demand and prices interrelation are modeled. Risk assessment of pricing and profit optimization by the regression of demand depending on price consists of three stages: a obtaining of a regression model of the demand on the price; b obtaining of function of demand price elasticity and risk assessment of pricing depending on behavior of the function; c determination of the price of company to receive a maximum operating profit based on the specific model of price to demand function. To receive the regression model of dependence of demand on price it is recommended to use specific reference models. The article includes linear, hyperbolic and parabolic models. The regression dependence of price elasticity of demand on price for each of the reference models of demand is obtained on the basis of the function elasticity concept in mathematical analysis. The concept of «function of price elasticity of demand» expresses this dependence. For the received functions of price elasticity of demand, the article provides intervals with the highest and lowest

  7. Free recall and outdoor running: cognitive and physical demand interference.

    Science.gov (United States)

    Epling, Samantha L; Blakely, Megan J; Russell, Paul N; Helton, William S

    2016-10-01

    Cognitive resource theory is a proposed explanation for people's limited ability to perform multiple tasks simultaneously. Reallocation of a restricted supply of cognitive resources to two or more tasks may be detrimental to performance on one or both tasks. Many professionals in high-risk fields, such as those engaged in firefighting, military, and search and rescue missions, face simultaneous mental and physical demands, yet little is known about the resources required to move over the natural terrain these operators may encounter. In the present research, we investigated whether interference was found between outdoor running and a word recall task. As hypothesized, a reduction in word recall was observed in the dual task compared to a recall-alone task; however, the distance run was not significantly different between the dual task and the run-alone task. Subjective reports of workload, task focus, and being "spent" (measures calculated from responses on a questionnaire) were greatest in the dual task. These results support the cognitive resource theory and have important theoretical and practical implications. Further research is required to better understand the type and extent of cognitive resources required by such physical tasks and the potential interference with simultaneous mental tasks.

  8. Performing a secondary executive task with affective stimuli interferes with decision making under risk conditions.

    Science.gov (United States)

    Gathmann, Bettina; Pawlikowski, Mirko; Schöler, Tobias; Brand, Matthias

    2014-05-01

    Previous studies demonstrated that executive functions are crucial for advantageous decision making under risk and that therefore decision making is disrupted when working memory capacity is demanded while working on a decision task. While some studies also showed that emotions can affect decision making under risk, it is unclear how affective processing and executive functions predict decision-making performance in interaction. The current experimental study used a between-subjects design to examine whether affective pictures (positive and negative pictures compared to neutral pictures), included in a parallel executive task (working memory 2-back task), have an impact on decision making under risk as assessed by the Game of Dice Task (GDT). Moreover, the performance GDT plus 2-back task was compared to the performance in the GDT without any additional task (GDT solely). The results show that the performance in the GDT differed between groups (positive, negative, neutral, and GDT solely). The groups with affective pictures, especially those with positive pictures in the 2-back task, showed more disadvantageous decisions in the GDT than the groups with neutral pictures and the group performing the GDT without any additional task. However, executive functions moderated the effect of the affective pictures. Regardless of affective influence, subjects with good executive functions performed advantageously in the GDT. These findings support the assumption that executive functions and emotional processing interact in predicting decision making under risk.

  9. Demand Response Valuation Frameworks Paper

    Energy Technology Data Exchange (ETDEWEB)

    Heffner, Grayson

    2009-02-01

    While there is general agreement that demand response (DR) is a valued component in a utility resource plan, there is a lack of consensus regarding how to value DR. Establishing the value of DR is a prerequisite to determining how much and what types of DR should be implemented, to which customers DR should be targeted, and a key determinant that drives the development of economically viable DR consumer technology. Most approaches for quantifying the value of DR focus on changes in utility system revenue requirements based on resource plans with and without DR. This ''utility centric'' approach does not assign any value to DR impacts that lower energy and capacity prices, improve reliability, lower system and network operating costs, produce better air quality, and provide improved customer choice and control. Proper valuation of these benefits requires a different basis for monetization. The review concludes that no single methodology today adequately captures the wide range of benefits and value potentially attributed to DR. To provide a more comprehensive valuation approach, current methods such as the Standard Practice Method (SPM) will most likely have to be supplemented with one or more alternative benefit-valuation approaches. This report provides an updated perspective on the DR valuation framework. It includes an introduction and four chapters that address the key elements of demand response valuation, a comprehensive literature review, and specific research recommendations.

  10. Developmental Differences in Effects of Task Pacing on Implicit Sequence Learning

    Directory of Open Access Journals (Sweden)

    Amanda Sue Hodel

    2014-02-01

    Full Text Available Although there is now substantial evidence that developmental change occurs in implicit learning abilities over the lifespan, disparate results exist regarding the specific developmental trajectory of implicit learning skills. One possible reason for discrepancies across implicit learning studies may be that younger children show an increased sensitivity to variations in implicit learning task procedures and demands relative to adults. Studies using serial-reaction time (SRT tasks have suggested that in adults, measurements of implicit learning are robust across variations in task procedures. Most classic SRT tasks have used response-contingent pacing in which the participant’s own reaction time determines the duration of each trial. However, recent paradigms with adults and children have used fixed trial pacing, which leads to alterations in both response and attention demands, accuracy feedback, perceived agency, and task motivation for participants. In the current study, we compared learning on fixed-paced and self-paced versions of a spatial sequence learning paradigm in 4-year-old children and adults. Results indicated that preschool-aged children showed reduced evidence of implicit sequence learning in comparison to adults, regardless of the SRT paradigm used. In addition, we found the preschoolers showed significantly greater learning when stimulus presentation was self-paced. These data provide evidence for developmental differences in implicit sequence learning that are dependent on specific task demands such as stimulus pacing, which may be related to developmental changes in the impact of broader constructs such as attention and task motivation on implicit learning.

  11. A self-organizing model for task allocation via frequent task quitting and random walks in the honeybee.

    Science.gov (United States)

    Johnson, Brian R

    2009-10-01

    Social insect colonies are able to quickly redistribute their thousands of workers between tasks that vary strongly in space and time. How individuals collectively track spatial variability is particularly puzzling because bees have access only to local information. This work presents and tests a model showing how honeybees solve their fundamental within-nest spatial task-allocation problem. The algorithm, which is self-organizing and derived from empirical studies, couples two processes with opposing effects. Frequent task quitting, followed by patrols, during which bees are insensitive to task stimuli, serves to randomize individual location throughout the nest without reference to variation in task demand, while a foraging-for-work-like mechanism provides the opposing force of localizing individuals to areas of high task demand. This simple model is shown to generate sophisticated patterns of task allocation. It allocates bees to tasks in proportion to their demand, independent of their spatial distribution in the nest, and also reallocates labor in response to temporal changes in task demand. Finally, the model shows that task-allocation patterns at the colony level do not reflect colonies allocating particular individuals to tasks. In contrast, they reflect a dynamic equilibrium of workers switching between tasks and locations in the nest.

  12. ACR-SNM Task Force on Nuclear Medicine Training: report of the task force.

    Science.gov (United States)

    Guiberteau, Milton J; Graham, Michael M

    2011-06-01

    The expansion of knowledge and technological advances in nuclear medicine and radiology require physicians to have more expertise in functional and anatomic imaging. The convergence of these two specialties into the new discipline of molecular imaging has also begun to place demands on residency training programs for additional instruction in physiology and molecular biology. These changes have unmasked weaknesses in current nuclear medicine and radiology training programs. Adding to the impetus for change are the attendant realities of the job market and uncertain employment prospects for physicians trained in nuclear medicine but not also trained in diagnostic radiology. With this background, the ACR and the Society of Nuclear Medicine convened the Task Force on Nuclear Medicine Training to define the issues and develop recommendations for resident training.

  13. Human Performance Task Batteries and Models: An Abilities-Based Directory

    Science.gov (United States)

    1986-12-01

    consonants or vowels (moderate demand); and (3) antonym match - in which only words opposite in meaning constiiutp a match (high demand). (PERCEPTUAL SPEED...creative or aesthetic tasks Soc/a/-personal contact or interpersonal tasks Enterprising- manipulative or persuasive tasks Conventional- routine or

  14. Stress in nonregular work arrangements: A longitudinal study of task- and employment-related aspects of stress.

    Science.gov (United States)

    Vahle-Hinz, Tim

    2016-10-01

    In nonregular forms of employment, such as fixed-term or temporary agency work, 2 sources of stress must be distinguished: task-related stress components (e.g., time pressure) and employment-related stress components (e.g., effort to maintain employment). The present study investigated the relationship between task- and employment-related demands and resources and indicators of strain, well-being, work engagement, and self-rated performance in a sample of nonregular employed workers. Using a 2-wave longitudinal design, the results of autoregressive cross-lagged structural equation models demonstrated that time pressure, as a task-related demand, is positively related to strain and negatively related to well-being and self-rated performance. Autonomy, as a task-related resource, exhibited no significant relationships in the current study. Employment-related demands exhibited negative relationships with well-being and work engagement as well as negative and positive relationships with self-rated performance over time. Employment-related resources were primarily positive predictors of well-being and self-rated performance. Fit indices of comparative models indicated that reciprocal effect models (which enable causal and reverse effects) best fit the data. Accordingly, demands and resources predicted strain, well-being, work engagement, and self-rated performance over time and vice versa. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. CONSUMER DEMAND FOR FOOD DIVERSITY

    OpenAIRE

    Lee, Jonq-Ying; Mark G. Brown

    1989-01-01

    In this paper, consumer demand for food diversity is measured by the entropy and Simpson indices for budget shares. Results show that consumer demand for food diversity is related to total food expenditures and household size and composition.

  16. Survey on current knowledge and demands of reproductive health among male migrant workers%企业男性流动人口生殖健康认知现况和服务需求调查

    Institute of Scientific and Technical Information of China (English)

    王奇玲

    2012-01-01

    Objective; To explore the status of knowledge and demands of reproductive health service among male migrant workers and provide the evidences for the optimal comprehensive intervention pattern. Methods; A total of 533 male migrant workers in Zhongshan city were interviewed with a questionnaire including general demography characteristics, sex activities,' knowledge and demands of reproductive health service. Results; About 87.1 percent of the participants desired regular sex ac- -tivity. The mean score of reproductive health knowledge for unmarried and married workers was 5.32 and 6.28, respectively, showing significant difference (P < 0.01). The results of logistic regression analysis suggested the scores were statistically influenced by marital status, educational level, with sex partner or not, contraceptive use or not, with unexpected pregnance or not and willing of taking part in reproductive health education for male migrant workers. Among them, 73.7 percent had never-obtained sexual and reproductive health education or contraceptive consulting services in their transient living areas. About 94. 52 percent of them wanted to participate reproductive health education, especially consulting services. Conclusion; The awareness of sexual and reproductive health is lower among male migrant workers. They eager for specific contraceptive and reproductive knowledge and personalized reproductive health services.%目的:了解外来男性生殖健康认知现况及服务需求,探讨相关影响因素,为建立最佳综合干预模式提供参考.方法:对中山市企业外来533名男性进行面访式问卷调查.结果:87.1%的男性渴望有规律性生活.性与生殖健康知识得分未婚男性(5.32±1.94)低于已婚男性(6.28±2.57) (P <0.01).logistic回归分析结果提示婚姻状况、文化程度、有无性伴侣、是否使用过避孕措施、有无导致性伴侣意外妊娠、是否愿意参加性与生殖健康宣教等影响调查男性的

  17. Bioeconomic Analysis of Pesticide Demand

    OpenAIRE

    Moffitt, L. Joe; Farnsworth, Richard L.

    1981-01-01

    The ability of insects to develop resistance to specific pesticides affects pesticide demand. However, the affect of resistance on demand cannot be observed or measured. This analysis substitutes an expression for the unobserved resistance variable in a pesticide demand model and then illustrates the model's potential by estimating demand for DDT. To arrive at the expression characterizing the unobserved resistance variable a biological resistance model is constructed then incorporated into t...

  18. Rewarding yet demanding

    DEFF Research Database (Denmark)

    Bjørkedal, S T B; Torsting, A M B; Møller, T

    2016-01-01

    AIM: The purpose of this study, by exploring client perspectives, was to achieve a better understanding of how people with schizophrenia experience an occupational therapy intervention designed to enable them to carry out meaningful occupations in the early phases of recovery. METHOD: A qualitative......, as demanding. Participants valued engaging in real-life occupations while anchoring new strategies but also the occupational therapist's role in dealing with failure. Participants felt the intervention assisted in their recovery process and enabled them to engage in meaningful occupations. CONCLUSION......: The study provided unique insight into how participants experienced a client-centred partnership with an occupational therapist in the early phases of recovery. The intervention was feasible and supported the participants' recovery process....

  19. Participatory Demand-supply Systems

    NARCIS (Netherlands)

    Rezaee, S.A.; Oey, M.A.; Nevejan, C.I.M.; Brazier, F.M.

    2015-01-01

    Introducing the notion of Participatory Demand-Supply (PDS) systems as socio-technical systems, this paper focuses on a new approach to coordinating demand and supply in dynamic environments. A participatory approach to demand and supply provides a new frame of reference for system design, for which

  20. Participatory Demand-supply Systems

    NARCIS (Netherlands)

    Rezaee, S.A.; Oey, M.A.; Nevejan, C.I.M.; Brazier, F.M.

    2015-01-01

    Introducing the notion of Participatory Demand-Supply (PDS) systems as socio-technical systems, this paper focuses on a new approach to coordinating demand and supply in dynamic environments. A participatory approach to demand and supply provides a new frame of reference for system design, for which

  1. The curvilinear relationship between state neuroticism and momentary task performance.

    Directory of Open Access Journals (Sweden)

    Jonas Debusscher

    Full Text Available A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity. In one, results showed that under high work pressure, the state neuroticism-task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism-momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands.

  2. The curvilinear relationship between state neuroticism and momentary task performance.

    Science.gov (United States)

    Debusscher, Jonas; Hofmans, Joeri; De Fruyt, Filip

    2014-01-01

    A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity). In one, results showed that under high work pressure, the state neuroticism-task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism-momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands.

  3. Signal probability effects on high-workload vigilance tasks.

    Science.gov (United States)

    Matthews, G

    1996-09-01

    Signal probability is an important influence on vigilance. Typically, higher signal probability is associated with higher hit rate, lower response criterion, and lower response:signal ratio. However, signal probability effects on demanding, high-workload vigilance tasks have not been investigated. It is believed that attentional resources become depleted during performance of such tasks, leading to perceptual sensitivity decrements. Forty subjects performed high- (.35) and low- (.10) probability versions of a demanding vigilance task. Results differed in two important respects from those previously obtained with less demanding tasks. First, the decrement in perceptual sensitivity over time was greater for the high-probability task. Second, there were no effects of signal probability on response criterion. Subjective workload was higher for the high-probability task. Implications of the data for resource-depletion and expectancy theories of vigilance are discussed.

  4. Current Demand for Preschool Teachers in Sichuan and Prediction of Its Development Scale in the "Twelfth Five-Year Plan" Period%四川幼儿师资需求现状及“十二五”时期发展规模预测

    Institute of Scientific and Technical Information of China (English)

    周洪

    2012-01-01

    《四川省学前教育三年行动纲领》提出了2011—2013年四川学前教育的具体任务,这是落实"十二五"时期四川学前教育发展目标的基础。本研究以客观的数据分析为支撑,揭示出四川幼儿师资需求的现状和其中存在的地区差异问题,并根据四川总人口及出生率、幼儿园毛入学率推算出在园儿童数,预测出"十二五"时期四川幼儿师资的发展规模。为了培养足够数量的合格幼儿教师,"十二五"时期政府应加大学前教育师资培养的财政投入,有计划地扩大高等师范院校学前教育专业的办学规模;师范院校应该为在职幼儿教师提供学前教育专业本、专科函授的学习机会;全省幼教培训机构要组织专、兼职的培训队伍,积极开展对高中学历及转岗人员的培训,以期全面提高幼儿教师的专业水平。%Three Year Action Programme of Sichuan Province Preschool Education puts forward the specific tasks of Sichuan preschool education during 2011-2013, which is the basis for the implementation of Sichuan preschool education development goals in the "Twelfth Five-Year Plan" period. Based on data analysis, this article first reveals the current demand for Sichuan preschool teachers and the existing problem of regional differences, then predicts the preschool teacher development scale according to the calculated number of children in the kindergarten from the total population, birth rate, and gross enrollment rate of Sichuan, and finally presents three suggestions to cultivate sufficient amount of qualified preschool teachers. The suggestions are as follows: 1 ) the government should increase financial investment to training of preschool teachers and expand the scale of preschool education major in normal schools systematically; 2) normal schools should provide study opportunities for in-service preschool teachers; 3 ) preschool education training institutions should

  5. Occupational demand and human rights. Public safety officers and cardiorespiratory fitness.

    Science.gov (United States)

    Shephard, R J

    1991-08-01

    The issue of discrimination in physically demanding employment, such as police, firefighters, prison guards and military personnel, is contentious. In terms of oxygen transport, the 'action limit' (calling for personnel selection or task redesign) is a steady oxygen consumption of 0.7 L/min, while the maximum permissible limit is 2.1 L/min. Note is taken of the commonly expressed belief that public safety duties are physically demanding, calling for personnel with an aerobic power of at least 3 L/min, or 42 to 45 ml/kg/min. The actual demands of such work can be assessed on small samples by physiological measurements (using heart rate or oxygen consumption meters), but the periods sampled may not be typical of a normal day. A Gestalt can also be formed as to the heaviness of a given job, or a detailed task analysis can be performed; most such analyses of public safety work list distance running and other aerobic activities infrequently. An arbitrary requirement of 'above average fitness' is no longer accepted by courts, but a further approach is to examine the characteristics of those currently meeting the demands of public safety jobs satisfactorily. Young men commonly satisfy the 3 L/min standard, but this is not usually the case for women or older men; in the case of female employees, it also seems unreasonable that they should be expected to satisfy the same standards as men, since a lower body mass reduces the energy cost of most of the tasks that they must perform. A second criterion sometimes applied to physically demanding work (a low vulnerability to heart attacks) is examined critically. It is concluded that the chances that a symptom-free public safety officer will develop a heart attack during a critical solo mission are so low that cardiac risk should not be a condition of employment. Arbitrary age- and sex-related employment criteria are plainly discriminatory, since some women and 65-year-old men have higher levels of physical fitness than the

  6. The Shipbuilding Industries of the U.S. and U.S.S.R. as Bases for National Maritime Policies: Current Capabilities and Surge Demand Potential. Volume I. Main Report

    Science.gov (United States)

    1981-02-01

    Structurals (MIL) 10 10 16 24 12 16 10 12 13 2. Alloy Steel HY80 Plate 12 14 24 26 20 20 16 16 20 Extrusions (MIL) 40 24 24 30 42 26 20 24 24 HY80 ...industries. However, for some specialized alloy steel plates such as HY80 for submarine hulls, the shipbuilders are almost the only users. The firms in...National Steel and Shipbuilding Company .......... .- 7 3-2 Ingalls Shipbuilding (Division of Litton Systemsinc - 3-3 Current (1980) Lead Times for

  7. Intrinsic motivation and organizational identification among on-demand workers.

    Science.gov (United States)

    Rockmann, Kevin W; Ballinger, Gary A

    2017-09-01

    On-demand firms provide services for clients through a network of on-demand workers ready to complete specific tasks for a set contractual price. Given such on-demand work is defined by payment on short-term contracts with no obligation for continued employment, there is little reason to believe on-demand workers experience more than extrinsic motivation and a transactional relationship with the on-demand firm. However, using self-determination theory, we argue that to the degree that on-demand work fulfills innate psychological needs individual on-demand workers will develop intrinsic motivation, which further leads to organizational identification with the on-demand firm. Across 2 survey-based studies we find support for this path to organizational identification. This adds to the literature on motivation and identification by strengthening the link between individual needs and the individual-organizational relationship. Implications for theory and for the management of on-demand workers are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. The shielding function of task rules in the context of task switching.

    Science.gov (United States)

    Reisenauer, Renate; Dreisbach, Gesine

    2014-02-01

    There is increasing evidence that task rules help shield the response against distractor interference. Here, the authors investigate the cognitive mechanisms underlying this assumed shielding function of task rules and how it is adjusted to changing task demands. In two experiments, participants switched between a noun categorization and an adjective categorization task. Target words were superimposed on distractor pictures. These pictures were always irrelevant and depicted either objects also used as target words in the noun task (noun distractors) or objects that were not part of the noun target-set but could be categorized according to the noun task (noun-related distractors). Results show that (a) on task repetitions shielding prevents interference from any distractors associated with a competing task; this is indicated by the lack of interference on adjective task repetitions; and (b) shielding is reduced on task switches. In the noun task, this reduction resulted in attenuated interference by noun-related distractors. In the adjective task, spatial distractors did not interfere despite the reduction. This result suggests that shielding is supported by a processing advantage for task-related information and not by distractor suppression.

  9. Optimal Demand Execution Strategy for the Defense Logistics Agency

    Science.gov (United States)

    2014-12-01

    a: ~ 8000 ~ 6000 :I z 4000 2000 0 5 Current PR Generation Demand Avg of March thru June 2014 - current - 5-day moving avg 10 15 20 25...March through June PR Generation The peak demand for daily PR execution per buyer is approximately 23 per day. At nearly 16,000 PRs per day, each of...Current Order Execution Strategy ..................................27  3.  Generate Hypothetical Workload Models

  10. Rats value time differently on equivalent foraging and delay-discounting tasks.

    Science.gov (United States)

    Carter, Evan C; Redish, A David

    2016-09-01

    All organisms have to consider consequences that vary through time. Theories explaining how animals handle intertemporal choice include delay-discounting models, in which the value of future rewards is discounted by the delay until receipt, and foraging models, which predict that decision-makers maximize rate of reward. We measured the behavior of rats on a 2-option delay-discounting task and a stay/go foraging task that were equivalent for rate of reward and physical demand. Despite the highly shared features of the tasks, rats were willing to wait much longer on the foraging task than on the delay-discounting task. Moreover, choice performance by rats was less optimal in terms of total reward received on the foraging task compared to the delay-discounting task. We applied a suite of intertemporal choice models to the data but found that we needed a novel model incorporating interactions of decision-making systems to successfully explain behavior. Our findings (a) highlight the importance of factors that historically have been seen as irrelevant and (b) indicate the inadequacy of current general theories of intertemporal choice. (PsycINFO Database Record

  11. Sex differences in verbal working memory performance emerge at very high loads of common neuroimaging tasks.

    Science.gov (United States)

    Reed, Jessica L; Gallagher, Natalie M; Sullivan, Marie; Callicott, Joseph H; Green, Adam E

    2017-04-01

    Working memory (WM) supports a broad range of intelligent cognition and has been the subject of rich cognitive and neural characterization. However, the highest ranges of WM have not been fully characterized, especially for verbal information. Tasks developed to test multiple levels of WM demand (load) currently predominate brain-based WM research. These tasks are typically used at loads that allow most healthy participants to perform well, which facilitates neuroimaging data collection. Critically, however, high performance at lower loads may obscure differences that emerge at higher loads. A key question not yet addressed at high loads concerns the effect of sex. Thoroughgoing investigation of high-load verbal WM is thus timely to test for potential hidden effects, and to provide behavioral context for effects of sex observed in WM-related brain structure and function. We tested 111 young adults, matched on genotype for the WM-associated COMT-Val(108/158)Met polymorphism, on three classic WM tasks using verbal information. Each task was tested at four WM loads, including higher loads than those used in previous studies of sex differences. All tasks loaded on a single factor, enabling comparison of verbal WM ability at a construct level. Results indicated sex effects at high loads across tasks and within each task, such that males had higher accuracy, even among groups that were matched for performance at lower loads.

  12. The functional neuroanatomy of multitasking: combining dual tasking with a short term memory task.

    Science.gov (United States)

    Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan

    2013-09-01

    Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.

  13. The interpersonal process model of demand/withdraw behavior.

    Science.gov (United States)

    Baucom, Brian R; Dickenson, Janna A; Atkins, David C; Baucom, Donald H; Fischer, Melanie S; Weusthoff, Sarah; Hahlweg, Kurt; Zimmermann, Tanja

    2015-02-01

    The demand/withdraw interaction pattern is a destructive cycle of relationship communication behavior that is associated with negative individual and relationship outcomes. Demand/withdraw behavior is thought to be strongly linked to partners' emotional reactions, but current theories are inconsistent with empirical findings. The current study proposes the interpersonal process model of demand/withdraw behavior, which includes linkages between each partners' emotional reactions and the interpersonal behavior of demanding and withdrawing. Data come from problem solving discussions of 55 German couples with observationally coded demand/withdraw behavior and fundamental frequency (f₀) to measure vocally encoded emotional arousal. Actor-partner interdependence models (Kenny, Kashy, & Cook, 2006) were used to examine associations among demand/withdraw behavior and f₀ in the overall discussion and 5-min segments. Significant cross-partner associations emerged for demanding and withdrawing behavior across the whole conversation as well as within 5-min segments, and these associations are partially accounted for by each individual's f₀. When behaviorally coded demanders expressed more vocal arousal, they demanded more and withdrew less while their partners withdrew more. In contrast, when behaviorally coded withdrawers expressed more vocal arousal, their partners demanded less and withdrew more. Findings demonstrate that demand/withdraw behavior varies between couples (i.e., some couples engage in a stronger demand/withdraw cycle than others) and between segments (i.e., when 1 partner increases demanding, the other increases withdrawing). Findings support key elements of the interpersonal process model, showing intra- and interpersonal pathways linking demand/withdraw behavior and emotion and demonstrate the importance of partners' behavioral roles in these linkages.

  14. Estimating Bicycle and Pedestrian Demand in San Diego

    OpenAIRE

    Jones, Michael; Buckland, Lauren

    2008-01-01

    This paper introduces the concepts behind estimating bicycle and pedestrian demand and provides an example of the development of a sketch-plan method for estimating bicycle and pedestrian demand from land use in San Diego County. The paper describes the methodology involved in collecting counts for the currently ongoing Seamless Travel project. The Seamless Travel project intends to develop a model for estimating bicycle and pedestrian demand within San Diego County. The project methodology i...

  15. Forecasting Ontario's blood supply and demand.

    Science.gov (United States)

    Drackley, Adam; Newbold, K Bruce; Paez, Antonio; Heddle, Nancy

    2012-02-01

    Given an aging population that requires increased medical care, an increasing number of deferrals from the donor pool, and a growing immigrant population that typically has lower donation rates, the purpose of this article is to forecast Ontario's blood supply and demand. We calculate age- and sex-specific donation and demand rates for blood supply based on 2008 data and project demand between 2008 and 2036 based on these rates and using population data from the Ontario Ministry of Finance. Results indicate that blood demand will outpace supply as early as 2012. For instance, while the total number of donations made by older cohorts is expected to increase in the coming years, the number of red blood cell (RBC) transfusions in the 70+ age group is forecasted grow from approximately 53% of all RBC transfusions in 2008 (209,515) in 2008 to 68% (546,996) by 2036. A series of alternate scenarios, including projections based on a 2% increase in supply per year and increased use of apheresis technology, delays supply shortfalls, but does not eliminate them without active management and/or multiple methods to increase supply and decrease demand. Predictions show that demand for blood products will outpace supply in the near future given current age- and sex-specific supply and demand rates. However, we note that the careful management of the blood supply by Canadian Blood Services, along with new medical techniques and the recruitment of new donors to the system, will remove future concerns. © 2012 American Association of Blood Banks.

  16. DEMAND CONTROLLED VENTILATION AND CLASSROOM VENTILATION

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Mendell, Mark J.; Davies, Molly; Eliseeva, Ekaterina; Faulkner, David; Hong, Tienzen; Sullivan, Douglas P.

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling. Major findings included: ? The single-location carbon dioxide sensors widely used for demand controlled ventilation frequently have large errors and will fail to effectively control ventilation rates (VRs).? Multi-location carbon dioxide measurement systems with more expensive sensors connected to multi-location sampling systems may measure carbon dioxide more accurately.? Currently-available optical people counting systems work well much of the time but have large counting errors in some situations. ? In meeting rooms, measurements of carbon dioxide at return-air grilles appear to be a better choice than wall-mounted sensors.? In California, demand controlled ventilation in general office spaces is projected to save significant energy and be cost effective only if typical VRs without demand controlled ventilation are very high relative to VRs in codes. Based on the research, several recommendations were developed for demand controlled ventilation specifications in the California Title 24 Building Energy Efficiency Standards.The research on classroom ventilation collected data over two years on California elementary school classrooms to investigate associations between VRs and student illness absence (IA). Major findings included: ? Median classroom VRs in all studied climate zones were below the California guideline, and 40percent lower in portable than permanent buildings.? Overall, one additional L/s per person of VR was associated with 1.6percent less IA. ? Increasing average VRs in California K-12 classrooms from the current average to the required level is estimated to decrease IA by 3.4percent, increasing State attendance-based funding to school districts by $33M, with $6.2 M in increased energy costs. Further VR increases would provide additional benefits

  17. On the market value of information commodities. III. Demand price

    NARCIS (Netherlands)

    Mowshowitz, A. (Abbe)

    1992-01-01

    textabstractThe derived‐demand price of an information commodity depends on the commodity's cost impact on a user's production process. We model an arbitrary production process as a collection of interrelated tasks which can be represented in the form of a production digraph. The nodes of the digrap

  18. Increasing working memory load reduces processing of cross-modal task-irrelevant stimuli even after controlling for task difficulty and executive capacity

    Directory of Open Access Journals (Sweden)

    Sharon Sanz Simon

    2016-08-01

    Full Text Available The classic account of the Load Theory (LT of attention suggests that increasing cognitive load leads to greater processing of task-irrelevant stimuli due to competition for limited executive resource that reduces the ability to actively maintain current processing priorities. Studies testing this hypothesis have yielded widely divergent outcomes. The inconsistent results may, in part, be related to variability in executive capacity (EC and task difficulty across subjects in different studies. Here, we used a cross-modal paradigm to investigate whether augmented working memory (WM load leads to increased early distracter processing, and controlled for the potential confounders of EC and task difficulty. Twenty-three young subjects were engaged in a primary visual WM task, under high and low load conditions, while instructed to ignore irrelevant auditory stimuli. Demands of the high load condition were individually titrated to make task difficulty comparable across subjects with differing EC. Event-related potentials (ERPs were used to measure neural activity in response to stimuli presented in both the task relevant modality (visual and task-irrelevant modality (auditory. Behavioral results indicate that the load manipulation and titration procedure of the primary visual task were successful. ERPs demonstrated that in response to visual target stimuli, there was a load-related increase in the posterior slow wave, an index of sustained attention and effort. Importantly, under high load, there was a decrease of the auditory N1 in response to distracters, a marker of early auditory processing. These results suggest that increased WM load is associated with enhanced attentional engagement and protection from distraction in a cross-modal setting, even after controlling for task difficulty and EC. Our findings challenge the classic LT and offer support for alternative models.

  19. Status and tasks of oil refinery industry

    Energy Technology Data Exchange (ETDEWEB)

    Ku, I.M. [Korea Petroleum Association, Seoul (Korea, Republic of)

    1998-05-01

    The oil refinery industry is currently undergoing more difficulties than other industries. Since crude oil is all imported, whose import amount is the biggest as single item, and usance financing that once extended up to one hundred eighty (180) days is not easy to get under the current exchange and financial crisis, there are many hardships in import of crude oil. With this, domestic petroleum products demand shows sudden decline trend while competition gets more intensified due to remarkable regulation relief and liberalization measures in oil refinery industry such as the liberalization of domestic oil prices, etc. It is estimated that it entered the low growth stage as high-growth age of double-digit ends due to several complicated factors and rapid changes of economic environment. Under these crisis situations, domestic oil refinery industry drives super retrenchment management and restructuring for survival, but they are bombarded with piled up tasks while faced with liberalization and outward opening of imminent oil refinery business and domestic petroleum market. Domestic oil refinery industry should provide petroleum energy, which is blood of national economy and industries steadily without interruption overcoming wisely the worst management crisis with collective wisdom based on the accumulated management know-how and experience for the past first generation, and I also firmly believe that they can do that. 21 tabs.

  20. A Study on Application of Task-based Teaching Approach to College Oral English Teaching

    Institute of Scientific and Technical Information of China (English)

    卞少辉

    2014-01-01

    This thesis reports an experimental study of Task-based L2 oral English teaching for English majors in a Chinese university. In the second language acquisition (SLA) field, teachers and researchers are devoted to finding a method, which functions as a bridge to join the usage and use of the language, the forms and meaning, and the process and product. Task-based teaching approach (TBTA) seems to satisfy such demands. Therefore, it has attracted wide attention in the field of SLA, become one of the hot spots of current theoretical study, and provided some theoretical guidance for the practice of foreign language teaching (FLT) and second language teaching (SLT). The researcher believes it is necessary to write a review concerning the origin, the development and the future of task-based teaching approach.

  1. Information Demand Pattern for Teams

    Directory of Open Access Journals (Sweden)

    Dirk Stamer

    2016-04-01

    Full Text Available Modern organizations face the challenge of having to manage an increasing amount of information. The resulting information overload leads more and more to problems in decision making with potentially negative economic consequences. Decision-makers and knowledge intensive workers are especially affected. To address this problem, information demand patterns were proposed which capture organizational knowledge about the information demand of single roles. This work extends the concept of information demand patterns from single roles to teams. Using the knowledge intensive field of project management, the paper shows how to apply the concept of information demand patterns for a whole team. The contributions of this work are (1 the methodical approach to develop information demand patterns for teams, (2 an actual information demand pattern for a steering committee in the context of project management, (3 reflections on the differences between role patterns and team patterns.

  2. Feeding a fierce demand

    Energy Technology Data Exchange (ETDEWEB)

    Zlontinov, D.

    2008-09-15

    Wolverine is a metallurgical coal mining project located in British Columbia (BC). The Wolverine project is owned by Western, who is currently expanding the project by developing an open pit mine property with a reserve of 18 million tonnes located close to its current mine. The company has purchased several new trucks, front shovel loaders, and blasthole drills, and is now shifting over 65,000 bank cubic meters (BCM) per day. Western is also planning to develop an underground mine in the region. The company has formed contracts and business relationships with several smaller companies in order to allow for more rapid startups of its mining operations. However, the company's expansion has been impeded by shortages in qualified mining personnel. The Wolverine project had been engaged in long-term contracts with the Japanese steel industry. Western has now established a number of relationships with clients in Europe, China, and South Korea. 3 figs.

  3. Cognitive demands of lower paleolithic toolmaking.

    Science.gov (United States)

    Stout, Dietrich; Hecht, Erin; Khreisheh, Nada; Bradley, Bruce; Chaminade, Thierry

    2015-01-01

    Stone tools provide some of the most abundant, continuous, and high resolution evidence of behavioral change over human evolution, but their implications for cognitive evolution have remained unclear. We investigated the neurophysiological demands of stone toolmaking by training modern subjects in known Paleolithic methods ("Oldowan", "Acheulean") and collecting structural and functional brain imaging data as they made technical judgments (outcome prediction, strategic appropriateness) about planned actions on partially completed tools. Results show that this task affected neural activity and functional connectivity in dorsal prefrontal cortex, that effect magnitude correlated with the frequency of correct strategic judgments, and that the frequency of correct strategic judgments was predictive of success in Acheulean, but not Oldowan, toolmaking. This corroborates hypothesized cognitive control demands of Acheulean toolmaking, specifically including information monitoring and manipulation functions attributed to the "central executive" of working memory. More broadly, it develops empirical methods for assessing the differential cognitive demands of Paleolithic technologies, and expands the scope of evolutionary hypotheses that can be tested using the available archaeological record.

  4. North American oil demand outlook

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, M.B. [National Economic Research Associates, White Plains, NY (United States)

    1995-11-01

    An understanding of the relationship of economic growth and potential petroleum product demand is needed to forecast the potential for North American oil demand growth as well as knowledge of world supply and price. The bullish expectations for economic growth in the US and Canada auger well for North American refiners and marketeers. The growth in world economic output forecast, however, means a larger oil demand and an increase in OPEC`s pricing power. Such price increases could depress North American oil demand growth. (author)

  5. An integrated communications demand model

    Science.gov (United States)

    Doubleday, C. F.

    1980-11-01

    A computer model of communications demand is being developed to permit dynamic simulations of the long-term evolution of demand for communications media in the U.K. to be made under alternative assumptions about social, economic and technological trends in British Telecom's business environment. The context and objectives of the project and the potential uses of the model are reviewed, and four key concepts in the demand for communications media, around which the model is being structured are discussed: (1) the generation of communications demand; (2) substitution between media; (3) technological convergence; and (4) competition. Two outline perspectives on the model itself are given.

  6. Do job demands and job control affect problem-solving?

    Science.gov (United States)

    Bergman, Peter N; Ahlberg, Gunnel; Johansson, Gun; Stoetzer, Ulrich; Aborg, Carl; Hallsten, Lennart; Lundberg, Ingvar

    2012-01-01

    The Job Demand Control model presents combinations of working conditions that may facilitate learning, the active learning hypothesis, or have detrimental effects on health, the strain hypothesis. To test the active learning hypothesis, this study analysed the effects of job demands and job control on general problem-solving strategies. A population-based sample of 4,636 individuals (55% women, 45% men) with the same job characteristics measured at two times with a three year time lag was used. Main effects of demands, skill discretion, task authority and control, and the combined effects of demands and control were analysed in logistic regressions, on four outcomes representing general problem-solving strategies. Those reporting high on skill discretion, task authority and control, as well as those reporting high demand/high control and low demand/high control job characteristics were more likely to state using problem solving strategies. Results suggest that working conditions including high levels of control may affect how individuals cope with problems and that workplace characteristics may affect behaviour in the non-work domain.

  7. Multi-modal demands of a smartphone used to place calls and enter addresses during highway driving relative to two embedded systems.

    Science.gov (United States)

    Reimer, Bryan; Mehler, Bruce; Reagan, Ian; Kidd, David; Dobres, Jonathan

    2016-12-01

    There is limited research on trade-offs in demand between manual and voice interfaces of embedded and portable technologies. Mehler et al. identified differences in driving performance, visual engagement and workload between two contrasting embedded vehicle system designs (Chevrolet MyLink and Volvo Sensus). The current study extends this work by comparing these embedded systems with a smartphone (Samsung Galaxy S4). None of the voice interfaces eliminated visual demand. Relative to placing calls manually, both embedded voice interfaces resulted in less eyes-off-road time than the smartphone. Errors were most frequent when calling contacts using the smartphone. The smartphone and MyLink allowed addresses to be entered using compound voice commands resulting in shorter eyes-off-road time compared with the menu-based Sensus but with many more errors. Driving performance and physiological measures indicated increased demand when performing secondary tasks relative to 'just driving', but were not significantly different between the smartphone and embedded systems. Practitioner Summary: The findings show that embedded system and portable device voice interfaces place fewer visual demands on the driver than manual interfaces, but they also underscore how differences in system designs can significantly affect not only the demands placed on drivers, but also the successful completion of tasks.

  8. Demand study for advanced dental hygiene educational degrees: part 2: assessing educational demand.

    Science.gov (United States)

    Driscoll, Annelise Ydstebo; Fottler, Myron; Liberman, Aaron; Pitts, Louise; Wan, Thomas T H

    2011-01-01

    Currently, the debate over the addition of the midlevel provider position for dental hygienists rages on. The midlevel provider (similar to the physician's assistant) in dentistry exists in a handful of states in various forms, but is hotly contested in many other states. This is the second half of a 2-part study undertaken to add to the current body of knowledge by addressing the clinical needs changing in our population and the associated demand study for additional educational degrees for dental hygienists to address these changing needs. Part 1 addressed a literature update on oral health and systemic correlations contributing to our populations' declining health conditions, whereas part 2 illustrates the results of the demand study. It attempts to benchmark "adequate demand" and applies the stakeholder theory as its theoretical framework.

  9. BATMAN: MOS Spectroscopy on Demand

    Science.gov (United States)

    Molinari, E.; Zamkotsian, F.; Moschetti, M.; Spano, P.; Boschin, W.; Cosentino, R.; Ghedina, A.; González, M.; Pérez, H.; Lanzoni, P.; Ramarijaona, H.; Riva, M.; Zerbi, F.; Nicastro, L.; Valenziano, L.; Di Marcantonio, P.; Coretti, I.; Cirami, R.

    2016-10-01

    Multi-Object Spectrographs (MOS) are the major instruments for studying primary galaxies and remote and faint objects. Current object selection systems are limited and/or difficult to implement in next generation MOS for space and ground-based telescopes. A promising solution is the use of MOEMS devices such as micromirror arrays, which allow the remote control of the multi-slit configuration in real time. TNG is hosting a novelty project for real-time, on-demand MOS masks based on MOEMS programmable slits. We are developing a 2048×1080 Digital-Micromirror-Device-based (DMD) MOS instrument to be mounted on the Galileo telescope, called BATMAN. It is a two-arm instrument designed for providing in parallel imaging and spectroscopic capabilities. With a field of view of 6.8×3.6 arcmin and a plate scale of 0.2 arcsec per micromirror, this astronomical setup can be used to investigate the formation and evolution of galaxies. The wavelength range is in the visible and the spectral resolution is R=560 for a 1 arcsec object, and the two arms will have 2k × 4k CCD detectors. ROBIN, a BATMAN demonstrator, has been designed, realized and integrated. We plan to have BATMAN first light by mid-2016.

  10. What would menthol smokers do if menthol in cigarettes were banned? Behavioral intentions and simulated demand.

    Science.gov (United States)

    O'Connor, Richard J; Bansal-Travers, Maansi; Carter, Lawrence P; Cummings, K Michael

    2012-07-01

      The US Food and Drug Administration must consider whether to ban the use of menthol in cigarettes. This study examines how current smokers might respond to such a ban on menthol cigarettes.   Convenience sample of adolescent and adult smokers recruited from an online survey panel.   United States, 2010.   A total of 471 adolescent and adult current cigarette smokers.   Respondents were asked a series of questions about how they might react if menthol cigarettes were banned. In addition, participants completed a simulation purchase task to estimate the demand for menthol and non-menthol cigarettes across a range of prices.   Overall, 36.1% of respondents said they always (18.9%) or usually (17.2%) smoked menthol cigarettes. When asked how they might respond to a ban on menthol cigarettes, 35% of current menthol smokers said they would stop smoking, and 25% said they would 'find a way to buy a menthol brand'. Those who reported they might quit tended to have greater current intentions to quit [odds ratio (OR) = 4.47], while those who reported that they might seek illicit menthol cigarettes were far less likely to report current intentions to quit (OR = 0.06). Estimates for demand elasticity for preferred cigarette type were similar for menthol (α = 0.0051) and non-menthol (α = 0.0049) smokers. Demand elasticity and peak consumption were related to usual cigarette type and cigarettes smoked per day, but did not appear to differ by race, gender or age.   Preliminary evidence suggests that a significant minority of smokers of menthol cigarettes in the United States would try to stop smoking altogether if such cigarettes were banned. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

  11. Brain network adaptability across task states.

    Directory of Open Access Journals (Sweden)

    Elizabeth N Davison

    2015-01-01

    Full Text Available Activity in the human brain moves between diverse functional states to meet the demands of our dynamic environment, but fundamental principles guiding these transitions remain poorly understood. Here, we capitalize on recent advances in network science to analyze patterns of functional interactions between brain regions. We use dynamic network representations to probe the landscape of brain reconfigurations that accompany task performance both within and between four cognitive states: a task-free resting state, an attention-demanding state, and two memory-demanding states. Using the formalism of hypergraphs, we identify the presence of groups of functional interactions that fluctuate coherently in strength over time both within (task-specific and across (task-general brain states. In contrast to prior emphases on the complexity of many dyadic (region-to-region relationships, these results demonstrate that brain adaptability can be described by common processes that drive the dynamic integration of cognitive systems. Moreover, our results establish the hypergraph as an effective measure for understanding functional brain dynamics, which may also prove useful in examining cross-task, cross-age, and cross-cohort functional change.

  12. Increasing demands on today's blood donors

    OpenAIRE

    McClelland, W. M.

    1985-01-01

    Recently in Northern Ireland there has been a rapid increase in demand for a variety of blood components. To meet this need a large proportion of routine blood donations must be processed at the Transfusion Centre. In addition, several blood components are collected direct from donors by apheresis techniques. Apheresis is currently restricted to the collection of components from highly selected donors, but in future this method is likely to be employed for collection of some routine component...

  13. Increasing demands on today's blood donors

    OpenAIRE

    McClelland, W. M.

    1985-01-01

    Recently in Northern Ireland there has been a rapid increase in demand for a variety of blood components. To meet this need a large proportion of routine blood donations must be processed at the Transfusion Centre. In addition, several blood components are collected direct from donors by apheresis techniques. Apheresis is currently restricted to the collection of components from highly selected donors, but in future this method is likely to be employed for collection of some routine component...

  14. Battelle estimate of launch service demand

    Science.gov (United States)

    Conlon, R. J.; Day, J. B.

    1987-01-01

    The annual non-NASA non-DOD demand for launches by non-Soviet services is estimated for the period 1986-2001 on the basis of currently available data. The assumptions and methods employed in generating the bottom-up Outside Users Payload Model, the data sources, and the use of equivalent Space Shuttle flights as a payload measure are explained in detail. The numerical results are presented in extensive tables and graphs and briefly characterized.

  15. Accuracy analysis of TDRSS demand forecasts

    Science.gov (United States)

    Stern, Daniel C.; Levine, Allen J.; Pitt, Karl J.

    1994-01-01

    This paper reviews Space Network (SN) demand forecasting experience over the past 16 years and describes methods used in the forecasts. The paper focuses on the Single Access (SA) service, the most sought-after resource in the Space Network. Of the ten years of actual demand data available, only the last five years (1989 to 1993) were considered predictive due to the extensive impact of the Challenger accident of 1986. NASA's Space Network provides tracking and communications services to user spacecraft such as the Shuttle and the Hubble Space Telescope. Forecasting the customer requirements is essential to planning network resources and to establishing service commitments to future customers. The lead time to procure Tracking and Data Relay Satellites (TDRS's) requires demand forecasts ten years in the future a planning horizon beyond the funding commitments for missions to be supported. The long range forecasts are shown to have had a bias toward underestimation in the 1991 -1992 period. The trend of underestimation can be expected to be replaced by overestimation for a number of years starting with 1998. At that time demand from new missions slated for launch will be larger than the demand from ongoing missions, making the potential for delay the dominant factor. If the new missions appear as scheduled, the forecasts are likely to be moderately underestimated. The SN commitment to meet the negotiated customer's requirements calls for conservatism in the forecasting. Modification of the forecasting procedure to account for a delay bias is, therefore, not advised. Fine tuning the mission model to more accurately reflect the current actual demand is recommended as it may marginally improve the first year forecasting.

  16. Contrasting activity profile of two distributed cortical networks as a function of attentional demands.

    Science.gov (United States)

    Popa, Daniela; Popescu, Andrei T; Paré, Denis

    2009-01-28

    Recent human functional MRI (fMRI) studies have revealed that two widely distributed groups of cortical areas display inverse changes in activity when attentional demands increase, with one group showing higher (task-on) and the second lower (task-off) blood oxygen level-dependent (BOLD) signals. Moreover, task-on and task-off regions also exhibit slow (cat homologues of task-on and task-off regions. In all states of vigilance, LFP power was lower in task-off than task-on regions with no difference in firing rates. Both sets of regions displayed slow (0.5-0.15 Hz) cyclical modulations in LFP power in all frequency bands but with large and variable phase differences such that task-on and task-off regions were often anticorrelated. Inversely correlated LFP power fluctuations were state-dependent in that they were much more frequent in waking and paradoxical sleep than in slow-wave sleep. Moreover, consistent with fMRI findings, when attentional demands increased, LFP power in task-on and task-off regions changed in opposite directions, further augmenting and decreasing, respectively. At odds with previous fMRI studies, however, the decreased LFP power in task-off regions was associated with increased firing rates, suggesting that the engagement of task-off regions might not be reduced but in fact enhanced during attention.

  17. Global Energy: Supply, Demand, Consequences, Opportunities (LBNL Summer Lecture Series)

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, Arun

    2008-07-29

    Summer Lecture Series 2009: Arun Majumdar, Director of the Environmental Energy Technologies Division, discusses current and future projections of economic growth, population, and global energy demand and supply, and explores the implications of these trends for the environment.

  18. Physical game demands in elite rugby union: a global positioning system analysis and possible implications for rehabilitation.

    Science.gov (United States)

    Coughlan, Garrett F; Green, Brian S; Pook, Paul T; Toolan, Eoin; O'Connor, Sean P

    2011-08-01

    Descriptive. To evaluate the physical demands of an international Rugby Union-level game using a global positioning system (GPS). Elite Rugby Union teams currently employ the latest technology to monitor and evaluate physical demands of training and games on their players. GPS data from 2 players, a back and a forward, were collected during an international Rugby Union game. Locomotion speed, total body load, and body load sustained in tackles and scrums were analyzed. Players completed an average distance of 6715 m and spent the major portion of the game standing or walking, interspersed with medium- and high-intensity running activities. The back performed a higher number of high-intensity sprints and reached a greater maximal speed. Body load data revealed that high levels of gravitational force are sustained in tackling and scrum tasks. The current study provides a detailed GPS analysis of the physical demands of international Rugby Union players. These data, when combined with game video footage, may assist sports medicine professionals in understanding the demands of the game and mechanism of injury, as well as improving injury rehabilitation.

  19. Demand Response in Smart Grids

    DEFF Research Database (Denmark)

    Hansen, Jacob; Knudsen, Jesper Viese; Annaswamy, Anuradha M.

    2014-01-01

    In recent decades, moves toward higher integration of Renewable Energy Resources have called for fundamental changes in both the planning and operation of the overall power grid. One such change is the incorporation of Demand Response (DR), the process by which consumers can adjust their demand i...

  20. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker &

  1. Technical Workers in Great Demand

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Labor and Social Security Ministry conducted a survey on 81 labor markets across China in the second quarter of this year, the results of which showed that the demand for technical workers, especially those of middle and senior titles, far outnumbers the supply.The survey shows that the demand/supply

  2. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker & Demerout

  3. CAREER GUIDE FOR DEMAND OCCUPATIONS.

    Science.gov (United States)

    LEE, E.R.; WELCH, JOHN L.

    THIS PUBLICATION UPDATES THE "CAREER GUIDE FOR DEMAND OCCUPATIONS" PUBLISHED IN 1959 AND PROVIDES COUNSELORS WITH INFORMATION ABOUT OCCUPATIONS IN DEMAND IN MANY AREAS WHICH REQUIRE PREEMPLOYMENT TRAINING. IT PRESENTS, IN COLUMN FORM, THE EDUCATION AND OTHER TRAINING USUALLY REQUIRED BY EMPLOYERS, HIGH SCHOOL SUBJECTS OF PARTICULAR PERTINENCE TO…

  4. Job demands-resources model

    NARCIS (Netherlands)

    A.B. Bakker (Arnold); E. Demerouti (Eva)

    2013-01-01

    markdownabstract* The question of what causes job stress and what motivates people has received a lot of research attention during the past five decades. In this paper, we discuss Job Demands-Resources (JD-R) theory, which represents an extension of the Job Demands-Resources model (Bakker & Demerout

  5. Does Knowledge Contribute to the Acceptance of Demand Response?

    Directory of Open Access Journals (Sweden)

    Salla Annala

    2014-03-01

    Full Text Available More flexible demand side would benefit the electricity markets, networks and sustainable power generation in many ways. The success of demand response programs, however, relies on consumer acceptance. This paper reviews previous studies about acceptability of different kinds of residential demand response programs. Furthermore, it discusses whether consumers who are more aware of the principles and benefits of demand response have more positive attitudes towards demand response programs. The results of the literature review and two survey studies suggest that price and security of supply are currently bigger motives to change consumption behaviour than environmental issues and that the savings expected to trigger any action (and to lead to lasting change in behaviour may be relatively high. Therefore, the framing of demand response programs goals may affect the acceptance. Additionally, consumers seem to prefer simple price structures that remain constant for a long time to more dynamic options.

  6. Automated Demand Response and Commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann; Watson, David S.; Motegi, Naoya; Bourassa, Norman

    2005-04-01

    This paper describes the results from the second season of research to develop and evaluate the performance of new Automated Demand Response (Auto-DR) hardware and software technology in large facilities. Demand Response (DR) is a set of activities to reduce or shift electricity use to improve the electric grid reliability and manage electricity costs. Fully-Automated Demand Response does not involve human intervention, but is initiated at a home, building, or facility through receipt of an external communications signal. We refer to this as Auto-DR. The evaluation of the control and communications must be properly configured and pass through a set of test stages: Readiness, Approval, Price Client/Price Server Communication, Internet Gateway/Internet Relay Communication, Control of Equipment, and DR Shed Effectiveness. New commissioning tests are needed for such systems to improve connecting demand responsive building systems to the electric grid demand response systems.

  7. Are demand forecasting techniques applicable to libraries?

    OpenAIRE

    1984-01-01

    Examines the nature and limitations of demand forecasting, discuses plausible methods of forecasting demand for information, suggests some useful hints for demand forecasting and concludes by emphasizing unified approach to demand forecasting.

  8. Are demand forecasting techniques applicable to libraries?

    OpenAIRE

    M S Sridhar

    1984-01-01

    Examines the nature and limitations of demand forecasting, discuses plausible methods of forecasting demand for information, suggests some useful hints for demand forecasting and concludes by emphasizing unified approach to demand forecasting.

  9. Cognitive task performance causes impaired maximum force production in human hand flexor muscles.

    Science.gov (United States)

    Bray, Steven R; Graham, Jeffrey D; Martin Ginis, Kathleen A; Hicks, Audrey L

    2012-01-01

    The purpose of this study was to investigate effects of demanding cognitive task performance on intermittent maximum voluntary muscle contraction (MVC) force production. Participants performed either a modified Stroop or control task for 22 min. After the first min and at 3-min intervals thereafter, participants rated fatigue, perceived mental exertion and performed a 4-s MVC handgrip squeeze. A mixed ANOVA showed a significant interaction, F(7, 259)=2.43, p=.02, with a significant linear reduction in MVC force production over time in the cognitively depleting condition (p=.01) and no change for controls. Ratings of perceived mental exertion, F(7, 252)=2.39, p<.05, mirrored the force production results with a greater linear increase over time in the cognitive depletion condition (p<.001) compared to controls. Findings support current views that performance of cognitively demanding tasks diminishes central nervous system resources that govern self-regulation of physical tasks requiring maximal voluntary effort. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Oral methylphenidate normalizes cingulate activity in cocaine addiction during a salient cognitive task

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, R.Z.; Goldstein, R.Z.; Woicik, P.A.; Maloney, T.; Tomasi, D.; Alia-Klein, N.; Shan, J.; Honorario, J.; Samaras, d.; Wang, R.; Telang, F.; Wang, G.-J.; Volkow, N.D.

    2010-09-21

    Anterior cingulate cortex (ACC) hypoactivations during cognitive demand are a hallmark deficit in drug addiction. Methylphenidate (MPH) normalizes cortical function, enhancing task salience and improving associated cognitive abilities, in other frontal lobe pathologies; however, in clinical trials, MPH did not improve treatment outcome in cocaine addiction. We hypothesized that oral MPH will attenuate ACC hypoactivations and improve associated performance during a salient cognitive task in individuals with cocaine-use disorders (CUD). In the current functional MRI study, we used a rewarded drug cue-reactivity task previously shown to be associated with hypoactivations in both major ACC subdivisions (implicated in default brain function) in CUD compared with healthy controls. The task was performed by 13 CUD and 14 matched healthy controls on 2 d: after ingesting a single dose of oral MPH (20 mg) or placebo (lactose) in a counterbalanced fashion. Results show that oral MPH increased responses to this salient cognitive task in both major ACC subdivisions (including the caudal-dorsal ACC and rostroventromedial ACC extending to the medial orbitofrontal cortex) in the CUD. These functional MRI results were associated with reduced errors of commission (a common impulsivity measure) and improved task accuracy, especially during the drug (vs. neutral) cue-reactivity condition in all subjects. The clinical application of such MPH-induced brain-behavior enhancements remains to be tested.

  11. Effects of task instruction on autobiographical memory specificity in young and older adults.

    Science.gov (United States)

    Ford, Jaclyn Hennessey; Rubin, David C; Giovanello, Kelly S

    2014-01-01

    Older adults tend to retrieve autobiographical information that is overly general (i.e., not restricted to a single event, termed the overgenerality effect) relative to young adults' specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy ageing, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults' memories might include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being.

  12. Age association of language task induced deactivation induced in a pediatric population.

    Science.gov (United States)

    Sun, Binjian; Berl, Madison M; Burns, Thomas G; Gaillard, William D; Hayes, Laura; Adjouadi, Malek; Jones, Richard A

    2013-01-15

    Task-induced deactivation (TID) potentially reflects the interactions between the default mode and task specific networks, which are assumed to be age dependent. The study of the age association of such interactions provides insight about the maturation of neural networks, and lays out the groundwork for evaluating abnormal development of neural networks in neurological disorders. The current study analyzed the deactivations induced by language tasks in 45 right-handed normal controls aging from 6 to 22 years of age. Converging results from GLM, dual regression and ROI analyses showed a gradual reduction in both the spatial extent and the strength of the TID in the DMN cortices as the brain matured from kindergarten to early adulthood in the absence of any significant change in task performance. The results may be ascribed to maturation leading to either improved multi-tasking (i.e. reduced deactivation) or reduced cognitive demands due to greater experience (affects both control and active tasks but leads to reduced overall difference). However, other effects, such as changes in the DMN connectivity that were not included in this study may also have influenced the results. In light of this, researchers should be cautious when investigating the maturation of DMN using TID. With a GLM analysis using the concatenated fMRI data from several paradigms, this study additionally identified an age associated increase of TID in the STG (bilateral), possibly reflecting the role of this area in speech perception and phonological processing.

  13. Increasing optimism abolishes pain-induced impairments in executive task performance.

    Science.gov (United States)

    Boselie, Jantine J L M; Vancleef, Linda M G; Smeets, Tom; Peters, Madelon L

    2014-02-01

    Coping with the demands of pain diminishes self-regulatory capacity and causes self-regulatory fatigue, which then leads to deteriorated executive task performance. It has been suggested that optimism can counteract the depletion of self-regulatory capacity. This study employed a 2 (optimism/no optimism)×2 (pain/no pain) between-subjects design to explore whether (1) experimentally induced pain (cold pressor task) deteriorates subsequent executive task performance, and (2) whether an optimism induction can counteract this sustained deteriorating effect of pain on executive task performance. Results indicated that although pain led to significantly worse performance on the executive functioning task in the no optimism condition, this sustained deteriorating effect of pain on task performance was abolished in the optimism condition. This finding is imperative because it suggests that optimism may be an important factor to implement in current psychological treatment approaches to diminish the negative impact of chronic pain on the ability to function in daily life.

  14. Effects of Task Instruction on Autobiographical Memory Specificity in Young and Older Adults

    Science.gov (United States)

    Ford, Jaclyn Hennessey; Rubin, David C.; Giovanello, Kelly S.

    2013-01-01

    Older adults tend to retrieve autobiographical information that is overly general (i.e. not restricted to a single event, termed the overgenerality effect) relative to young adults’ specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy aging, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study, participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults’ memories may include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being. PMID:23915176

  15. "Task" as Research Construct

    Science.gov (United States)

    Seedhouse, Paul

    2005-01-01

    The article examines "task" as research construct as predominantly conceived in terms of task-as-workplan in the task-based learning/second language acquisition literature. It is suggested that "task" has weak construct validity and ontology in an overwhelmingly quantitative paradigm because the construct has a "split personality."…

  16. Effect of fixation tasks on multifocal visual evoked potentials.

    Science.gov (United States)

    Martins, Alessandra; Klistorner, Alexander; Graham, Stuart; Billson, Frank

    2005-10-01

    This study investigated the effects of cognitive influence on the multifocal visual evoked potential (mVEP) at different levels of eccentricity. Three different foveal fixation conditions were utilized involving varying levels of task complexity. A more complex visual fixation task has been known to suppress peripheral signals in subjective testing. Twenty normal subjects had monocular mVEPs recorded using the AccuMap objective perimeter. This allowed simultaneous stimulation of 58 segments of the visual field to an eccentricity of 24 degrees. The mVEP was recorded using three different fixation conditions in random order. During task 1 the subject passively viewed the central fixation area. For task 2 alternating numbers were displayed within the fixation area; the subject on viewing the number '3' in the central fixation area indicated recognition by pressing a button. Throughout task 3, numbers were displayed as in task 2. The subject had the cognitive task of summating all the numbers. Analysis revealed that the increased attention and concentration demanded by tasks 2 and 3 in comparison with task 1 resulted in significantly enhanced central amplitudes of 9.41% (Mann-Whitney P = 0.0002) and 13.45% (P = 0.0002), respectively. These amplitudes became reduced in the periphery and approached those of task 1, resulting in no significant difference between the three tasks. Latencies demonstrated no significant difference between each task nor at any eccentricity (P > 0.05). As the complexity of each task increased the amount of alpha rhythm was significantly reduced. Our findings indicate that task 1 required a minimal demand of cognition and was associated with the greatest amount of alpha rhythm. It was also the most difficult to perform because of loss of interest. The other two tasks required a greater demand of higher order cognitive skills resulting in significantly enhanced amplitudes centrally and the attenuation of alpha rhythm. Therefore, amplitudes are

  17. Motor demands impact speed of information processing in autism spectrum disorders.

    Science.gov (United States)

    Kenworthy, Lauren; Yerys, Benjamin E; Weinblatt, Rachel; Abrams, Danielle N; Wallace, Gregory L

    2013-09-01

    The apparent contradiction between preserved or even enhanced perceptual processing speed on inspection time tasks in autism spectrum disorders (ASD) and impaired performance on complex processing speed tasks that require motor output (e.g., Wechsler Processing Speed Index) has not yet been systematically investigated. This study investigates whether adding motor output demands to an inspection time task impairs ASD performance compared to that of typically developing control (TDC) children. The performance of children with ASD (n = 28; mean Full Scale IQ (FSIQ) = 115) and TDC (n = 25; mean FSIQ = 122) children was compared on processing speed tasks with increasing motor demand. Correlations were run between ASD task performance and Autism Diagnostic Observation Schedule (ADOS) Communication scores. Performance by the ASD and TDC groups on a simple perceptual processing speed task with minimal motor demand was equivalent, though it diverged (ASD worse than TDC) on 2 tasks with the same stimuli but increased motor output demands. ASD performance on the moderate but not the high speeded motor output demand task was negatively correlated with ADOS communication symptoms. These data address the apparent contradiction between preserved inspection time in the context of slowed "processing speed" in ASD. They show that processing speed is preserved when motor demands are minimized, but that increased motor output demands interfere with the ability to act on perceptual processing of simple stimuli. Reducing motor demands (e.g., through the use of computers) may increase the capacity of people with ASD to demonstrate good perceptual processing in a variety of educational, vocational, and social settings.

  18. The quality of task times: A methods research

    NARCIS (Netherlands)

    Schilden, van der M.

    1996-01-01

    IMAG-DLO is faced with large demands for labor data in spite of limited research capacity. Consequently IMAG-DLO is greatly concerned for the efficiency of the methodology used in task time synthesis, with even greater concern for maintaining the quality of the estimates of task times. Much effort h

  19. Operation Compatibility: A Neglected Contribution to Dual-Task Costs

    Science.gov (United States)

    Pannebakker, Merel M.; Band, Guido P. H.; Ridderinkhof, K. Richard

    2009-01-01

    Traditionally, dual-task interference has been attributed to the consequences of task load exceeding capacity limitations. However, the current study demonstrates that in addition to task load, the mutual compatibility of the concurrent processes modulates whether 2 tasks can be performed in parallel. In 2 psychological refractory period…

  20. Algae as a Feedstock for Biofuels. An Assessment of the Current Status and Potential for Algal Biofuels Production. Joint Summary report of IEA-AMF Annex XXXIV-2 and IEA Bioenergy Task 39

    Energy Technology Data Exchange (ETDEWEB)

    O' Conner, D. [S and T2 Consultants, Inc. (Canada)

    2011-09-15

    In 2010, the IEA Advanced Motor Fuels Implementing Agreement and the IEA Bioenergy Task 39 both commissioned reports on the status and potential opportunities for Algal Biofuels. While there were substantial similarities in the findings of the two reports, each report provides unique perspectives on different aspects of the technology and the opportunities. This summary draws on both of those reports. The Task 39 report (Bioenergy Algal Biofuels.pdf) was authored by Al Darzins and Philip Pienkos (NREL, US) and Les Edye (BioIndustry Partners, Australia). The IEA AMF report was prepared by Karen Sikes and Ralph McGill (Sentech, Inc. US) and Martijn Van Walwijk (Independent Researcher).

  1. Consumer demand and quality assurance

    DEFF Research Database (Denmark)

    Grunert, Klaus G; Wognum, Nel; Trienekens, Jacques

    2011-01-01

    Consumers differ in their demands, and this mau have implications for the type of supply chain governance that is most suitable for serving them. We present a segmentation of pork consumers in the EU based on their food-related lifestyles and demand for different pork products. We then present...... an inventory of pork chain governance and quality management systems, also resulting from a pan-European study, and attempt to match types of chains to consumer segments, arguing that the type of quality demanded by the consumers has implications especially for the quality management system governing the chain...

  2. Demand, Energy, and Power Factor

    Science.gov (United States)

    1994-08-01

    demand, but first, let’s talk some more about why electrical demand charges occur. Electric Load Leveling: 5 ** show flip chart of daily utility load (see...and cost savings for energy are available as a result of lowering demand. 3 ’~ show flip chart of block structure (see copy at end of script) Shown... flip chart (see copy at end of script) This is a graphical representation of real, apparent and reactive power in3 an AC circuit. Real power is the power

  3. Studying the Classroom Implementation of Tasks: High-Level Mathematical Tasks Embedded in "Real-Life" Contexts

    Science.gov (United States)

    Stylianides, Andreas J.; Stylianides, Gabriel J.

    2008-01-01

    Mathematical tasks embedded in real-life contexts have received increased attention by educators, in part due to the considerable levels of student engagement often triggered by their motivational features. Nevertheless, it is often challenging for teachers to implement high-level (i.e., cognitively demanding), real-life tasks in ways that exploit…

  4. The effect of task complexity and task conditions on foreign language development and performance: three empirical studies

    NARCIS (Netherlands)

    Sercu, L.; de Wachter, L.; Peters, E.; Kuiken, F.; Vedder, I.

    2006-01-01

    It has been argued that tasks constitute a valid alternative unit to sequence the language learning process, as opposed to linguistically defined syllabuses. Implementing this claim presupposes that it is possible to access the cognitive and linguistic demands of tasks, so that they can be sequenced

  5. Visualisation turns down energy demand

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Ole Michael [Danish Building and Urban Research, Hoersholm (Denmark)

    2003-07-01

    After many energy saving campaigns, Danish families give the impression that they are conscious of energy consumption. Children have learned to turn off the light and adults to buy low-energy bulbs and household appliances. Questioned about their energy consumption and its fluctuations, the same people nevertheless confess to not really knowing. You pay your energy bill but pay no attention to the current consumption, or its level. Unlike other types of consumption, energy consumption is an almost invisible type of consumption. Nevertheless, as a secondary consumption it is much affected by primary consumption in the form of white goods, appliances, cars, food etc., the main purpose of which usually is visibility. This paper presents the result of an experiment to make the energy consumption visible. Meters in the flats showing actual electricity, heat and water consumption confront tenants with the consequences of their own behaviour. The experiment also investigates different set-ups concerning information and communication about energy consumption. Monthly consumption and levels of consumption compared within the neighbourhood are elements of this information. Also quarterly eco-accounting, with key-figures of consumption and environmental considerations like CO{sub 2} emission, are part of the information set-up. Within the first year of visualisation one case shows a 9% reduction of heat and a 22% reduction of electricity. The other cases seem to follow the same tendency. The philosophy of the experiment is that you must know your position in order to change it. You must know about the level of your own energy consumption in order to turn down energy demand. The visible meters are elements in 'Urban Ecological Renewal of a Housing Block' (Hedebygade Block) in a central district of Copenhagen.

  6. Musical expertise has minimal impact on dual task performance.

    Science.gov (United States)

    Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea R

    2017-05-01

    Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.

  7. Recalling academic tasks

    Science.gov (United States)

    Draper, Franklin Gno

    This study was focused on what students remembered about five middle school science tasks when they were juniors and seniors in high school. Descriptions of the five tasks were reconstructed from available artifacts and teachers' records, notes and recollections. Three of the five tasks were "authentic" in the sense that students were asked to duplicate the decisions practitioners make in the adult world. The other two tasks were more typical school tasks involving note taking and preparation for a quiz. All five tasks, however, involved use of computers. Students were interviewed to examine what and how well they recalled the tasks and what forms or patterns of recall existed. Analysis of their responses indicated that different kinds of tasks produced different levels of recall. Authentically situated tasks were remembered much better than routine school tasks. Further, authentic tasks centered on design elements were recalled better than those for which design was not as pivotal. Patterns of recall indicated that participants most often recalled the decisions they made, the scenarios of the authentically situated tasks, the consequences of their tasks and the social contexts of the classroom. Task events, in other words, appeared to form a framework upon which students constructed stories of the tasks. The more salient the events, the richer the story, the deeper and more detailed the recall of the task. Thus, authentic tasks appeared to lend themselves to creating stories better than regular school tasks and therefore such tasks were recalled better. Implications of these patterns of recall are discussed with respect to issues of school learning and assessment.

  8. Data Science in Supply Chain Management: Data-Related Influences on Demand Planning

    Science.gov (United States)

    Jin, Yao

    2013-01-01

    Data-driven decisions have become an important aspect of supply chain management. Demand planners are tasked with analyzing volumes of data that are being collected at a torrential pace from myriad sources in order to translate them into actionable business intelligence. In particular, demand volatilities and planning are vital for effective and…

  9. Data Science in Supply Chain Management: Data-Related Influences on Demand Planning

    Science.gov (United States)

    Jin, Yao

    2013-01-01

    Data-driven decisions have become an important aspect of supply chain management. Demand planners are tasked with analyzing volumes of data that are being collected at a torrential pace from myriad sources in order to translate them into actionable business intelligence. In particular, demand volatilities and planning are vital for effective and…

  10. DEMAND CATEGORISATION, FORECASTING, AND INVENTORY CONTROL FOR INTERMITTENT DEMAND ITEMS

    Directory of Open Access Journals (Sweden)

    E. Babiloni

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: It is commonly assumed that intermittent demand appears randomly, with many periods without demand; but that when it does appear, it tends to be higher than unit size. Basic and well-known forecasting techniques and stock policies perform very poorly with intermittent demand, making new approaches necessary. To select the appropriate inventory management policy, it is important to understand the demand pattern for the items, especially when demand is intermittent. The use of a forecasting method designed for an intermittent demand pattern, such as Croston’s method, is required instead of a simpler and more common approach such as exponential smoothing. The starting point is to establish taxonomic rules to select efficiently the most appropriate forecasting and stock control policy to cope with thousands of items found in real environments. This paper contributes to the state of the art in: (i categorisation of the demand pattern; (ii methods to forecast intermittent demand; and (iii stock control methods for items with intermittent demand patterns. The paper first presents a structured literature review to introduce managers to the theoretical research about how to deal with intermittent demand items in both forecasting and stock control methods, and then it points out some research gaps for future development for the three topics.

    AFRIKAANSE OPSOMMING: Daar word algemeen aanvaar dat intermitterende vraag op toevalswyse voorkom, met verskeie periodes waar daar geen vraag is nie. Wanneer die vraag dan wel materialiseer, oorskry dit dikwels die eenheidsgrootte. Die bekende vooruitskattingstegnieke en voorraadbeleidstellings het min sukses waar intermitterende vraag voorkom, sodat nuwe benaderings nodig is om die problem aan te spreek. Om ‘n geskikte voorraadbestuur-beleid te selekteer, is dit noodsaaklik om die vraagpatroon van die items te verstaan, juis in gevalle van intermitterende patrone. Die gebruik van

  11. Temperature Effect on Energy Demand

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Duk [Korea Energy Economics Institute, Euiwang (Korea)

    1999-03-01

    We provide various estimates of temperature effect for accommodating seasonality in energy demand, particularly natural gas demand. We exploit temperature response and monthly temperature distribution to estimate the temperature effect on natural gas demand. Both local and global smoothed temperature responses are estimated from empirical relationship between hourly temperature and hourly energy consumption data during the sample period (1990 - 1996). Monthly temperature distribution estimates are obtained by kernel density estimation from temperature dispersion within a month. We integrate temperature response and monthly temperature density over all the temperatures in the sample period to estimate temperature effect on energy demand. Then, estimates of temperature effect are compared between global and local smoothing methods. (author). 15 refs., 14 figs., 2 tabs.

  12. Consumer demand and quality assurance

    DEFF Research Database (Denmark)

    Grunert, Klaus G; Wognum, Nel; Trienekens, Jacques

    2011-01-01

    Consumers differ in their demands, and this mau have implications for the type of supply chain governance that is most suitable for serving them. We present a segmentation of pork consumers in the EU based on their food-related lifestyles and demand for different pork products. We then present an......, and that these implications are different for fresh meat and processed meat. The paper closes with a call for more collaboration between chain researchers and consumer researchers.......Consumers differ in their demands, and this mau have implications for the type of supply chain governance that is most suitable for serving them. We present a segmentation of pork consumers in the EU based on their food-related lifestyles and demand for different pork products. We then present...

  13. Saving Electricity and Demand Response

    Science.gov (United States)

    Yamaguchi, Nobuyuki

    A lot of people lost their lives in the tremendous earthquake in Tohoku region on March 11. A large capacity of electric power plants in TEPCO area was also damaged and large scale power shortage in this summer is predicted. In this situation, electricity customers are making great effort to save electricity to avoid planned outage. Customers take actions not only by their selves but also by some customers' cooperative movements. All actions taken actually are based on responses to request form the government or voluntary decision. On the other hand, demand response based on a financial stimulus is not observed as an actual behavior. Saving electricity by this demand response only discussed in the newspapers. In this commentary, the events regarding electricity-saving measure after this disaster are described and the discussions on demand response, especially a raise in power rate, are put into shapes in the context of this electricity supply-demand gap.

  14. Kokkos? Task DAG Capabilities.

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Harold C.; Ibanez, Daniel Alejandro

    2017-09-01

    This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Task DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.

  15. Demand Response Spinning Reserve Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H.; Nelson-Hoffman, Janine; Torres, Carlos; Hirth,Scott; Yinger, Bob; Kueck, John; Kirby, Brendan; Bernier, Clark; Wright,Roger; Barat, A.; Watson, David S.

    2007-05-01

    The Demand Response Spinning Reserve project is a pioneeringdemonstration of how existing utility load-management assets can providean important electricity system reliability resource known as spinningreserve. Using aggregated demand-side resources to provide spinningreserve will give grid operators at the California Independent SystemOperator (CAISO) and Southern California Edison (SCE) a powerful, newtool to improve system reliability, prevent rolling blackouts, and lowersystem operating costs.

  16. Information Demand Pattern for Teams

    OpenAIRE

    Dirk Stamer; Kurt Sandkuhl; Veronika Zeiner

    2016-01-01

    Modern organizations face the challenge of having to manage an increasing amount of information. The resulting information overload leads more and more to problems in decision making with potentially negative economic consequences. Decision-makers and knowledge intensive workers are especially affected. To address this problem, information demand patterns were proposed which capture organizational knowledge about the information demand of single roles. This work extends the concept of informa...

  17. Workplace for analysis of task performance

    NARCIS (Netherlands)

    Bos, J; Mulder, LJM; van Ouwerkerk, RJ; Maarse, FJ; Akkerman, AE; Brand, AN; Mulder, LJM

    2003-01-01

    In current research on mental workload and task performance a large gap exists between laboratory based studies and research projects in real life working practice. Tasks conducted within a laboratory environment often lack a strong resemblance with real life working situations. This paper presents

  18. Workplace for analysis of task performance

    NARCIS (Netherlands)

    Bos, J; Mulder, LJM; van Ouwerkerk, RJ; Maarse, FJ; Akkerman, AE; Brand, AN; Mulder, LJM

    2003-01-01

    In current research on mental workload and task performance a large gap exists between laboratory based studies and research projects in real life working practice. Tasks conducted within a laboratory environment often lack a strong resemblance with real life working situations. This paper presents

  19. Components of competitor priming in task switching.

    Science.gov (United States)

    Teskey, Morgan L; Masson, Michael E J

    2017-07-17

    Executing an action in response to a stimulus is thought to result in the creation of an event code that integrates stimulus and action features (Allport, 1987; Hommel in Visual Cognition 5: 183-216, 1998). When switching between tasks, competitor priming occurs if a distractor stimulus cues the retrieval of a previously established event code in which that distractor is bound to a competing task, creating a source of interference with the current task whereby the observer is encouraged to apply the competing task to the distractor. We propose a second aspect of competitor priming: the misapplication of the retrieved competing task to the target stimulus. We report two task-switching experiments in which tasks applied to picture-word compound stimuli were manipulated to create conditions in which this second aspect of competitor priming could be revealed and distinguished from other sources of task- and stimulus-based priming. A substantial increase in competitor priming was observed when subjects switched between tasks that required very different processing operations and the competing task was highly relevant to the target stimulus. These results are consistent with our claim that competitor priming can result from applying the competing task either to the distractor that cued it or to the target stimulus.

  20. Estimating cross-price elasticity of e-cigarettes using a simulated demand procedure.

    Science.gov (United States)

    Grace, Randolph C; Kivell, Bronwyn M; Laugesen, Murray

    2015-05-01

    Our goal was to measure the cross-price elasticity of electronic cigarettes (e-cigarettes) and simulated demand for tobacco cigarettes both in the presence and absence of e-cigarette availability. A sample of New Zealand smokers (N = 210) completed a Cigarette Purchase Task to indicate their demand for tobacco at a range of prices. They sampled an e-cigarette and rated it and their own-brand tobacco for favorability, and indicated how many e-cigarettes and regular cigarettes they would purchase at 0.5×, 1×, and 2× the current market price for regular cigarettes, assuming that the price of e-cigarettes remained constant. Cross-price elasticity for e-cigarettes was estimated as 0.16, and was significantly positive, indicating that e-cigarettes were partially substitutable for regular cigarettes. Simulated demand for regular cigarettes at current market prices decreased by 42.8% when e-cigarettes were available, and e-cigarettes were rated 81% as favorably as own-brand tobacco. However when cigarettes cost 2× the current market price, significantly more smokers said they would quit (50.2%) if e-cigarettes were not available than if they were available (30.0%). Results show that e-cigarettes are potentially substitutable for regular cigarettes and their availability will reduce tobacco consumption. However, e-cigarettes may discourage smokers from quitting entirely as cigarette price increases, so policy makers should consider maintaining a constant relative price differential between e-cigarettes and tobacco cigarettes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  2. Demand-responsive public transportation re-scheduling for adjusting to the joint leisure activity demand

    Directory of Open Access Journals (Sweden)

    Konstantinos Gkiotsalitis

    2016-10-01

    Full Text Available Fixed daily trips such as trips to work/school have fixed departure/arrival times and destination points. The recurrent nature of fixed activities facilitates individuals on making more well-informed decisions about the transport mode selection. On the contrary, selecting a transportation mode for non-recurrent leisure trips, which can account for up to 60% of trips in some cities (Transport for London, 2014, is a more complex task due to the fact that individuals have little knowledge about the alternative modal options. In this paper, we try to improve the operations of demand-responsive public transportation systems by increasing their service quality and their ridership related to joint-leisure-trips via timetable rescheduling. First, we model the public transport service re-scheduling problem considering operational regulations and the quality of service. Then, a sequential heuristic method is introduced for re-scheduling the timetables of demand-responsive public transport modes in near-real time and accommodating the joint leisure activity demand without deteriorating the quality of service. The public transport re-scheduling for increasing the joint leisure activity ridership was tested in a case study using user-generated data from social media in Stockholm and the General Transit Feed Specification (GTFS data from Sweden focusing especially on central bus lines 1 and 4.

  3. Data-driven Demand Response Characterization and Quantification

    DEFF Research Database (Denmark)

    Le Ray, Guillaume; Pinson, Pierre; Larsen, Emil Mahler

    2017-01-01

    Analysis of load behavior in demand response (DR) schemes is important to evaluate the performance of participants. Very few real-world experiments have been carried out and quantification and characterization of the response is a difficult task. Nevertheless it will be a necessary tool for portf......Analysis of load behavior in demand response (DR) schemes is important to evaluate the performance of participants. Very few real-world experiments have been carried out and quantification and characterization of the response is a difficult task. Nevertheless it will be a necessary tool...... on the average values and standard deviation of the contribution regroups households with the same average response. Independent Component Analysis (ICA) is used to characterize different DR delivery profiles....

  4. Energy supply and demand in California

    Science.gov (United States)

    Griffith, E. D.

    1978-01-01

    The author expresses his views on future energy demand on the west coast of the United States and how that energy demand translates into demand for major fuels. He identifies the major uncertainties in determining what future demands may be. The major supply options that are available to meet projected demands and the policy implications that flow from these options are discussed.

  5. Launching Complex Tasks

    Science.gov (United States)

    Jackson, Kara J.; Shahan, Emily C.; Gibbons, Lynsey K.; Cobb, Paul A.

    2012-01-01

    Mathematics lessons can take a variety of formats. In this article, the authors discuss lessons organized around complex mathematical tasks. These lessons usually unfold in three phases. First, the task is introduced to students. Second, students work on solving the task. Third, the teacher "orchestrates" a concluding whole-class discussion in…

  6. Task assignment and coaching

    NARCIS (Netherlands)

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching fr

  7. Load Reduction, Demand Response and Energy Efficient Technologies and Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Paul A.; Parker, Graham B.; Hatley, Darrel D.

    2008-11-19

    The Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) was tasked by the DOE Office of Electricity (OE) to recommend load reduction and grid integration strategies, and identify additional demand response (energy efficiency/conservation opportunities) and strategies at the Forest City Housing (FCH) redevelopment at Pearl Harbor and the Marine Corps Base Hawaii (MCBH) at Kaneohe Bay. The goal was to provide FCH staff a path forward to manage their electricity load and thus reduce costs at these FCH family housing developments. The initial focus of the work was at the MCBH given the MCBH has a demand-ratchet tariff, relatively high demand (~18 MW) and a commensurate high blended electricity rate (26 cents/kWh). The peak demand for MCBH occurs in July-August. And, on average, family housing at MCBH contributes ~36% to the MCBH total energy consumption. Thus, a significant load reduction in family housing can have a considerable impact on the overall site load. Based on a site visit to the MCBH and meetings with MCBH installation, FCH, and Hawaiian Electric Company (HECO) staff, recommended actions (including a "smart grid" recommendation) that can be undertaken by FCH to manage and reduce peak-demand in family housing are made. Recommendations are also made to reduce overall energy consumption, and thus reduce demand in FCH family housing.

  8. Emotional Demands at Work and the Risk of Clinical Depression

    DEFF Research Database (Denmark)

    Vammen, Marianne Agergaard; Mikkelsen, Sigurd; Kolstad, Henrik

    2016-01-01

    OBJECTIVE: This study is a 2-year follow-up study of different dimensions of work-related emotional demands as a predictor for clinical depression. METHODS: In a two-wave study, 3224 (72%) public employees from 474 work-units participated twice by filling in questionnaires. Sixty-two cases of cli....... CONCLUSIONS: The personal perception of emotional demands was a risk factor for clinical depression but specific emotionally demanding work tasks were not.......OBJECTIVE: This study is a 2-year follow-up study of different dimensions of work-related emotional demands as a predictor for clinical depression. METHODS: In a two-wave study, 3224 (72%) public employees from 474 work-units participated twice by filling in questionnaires. Sixty-two cases...... of clinical depression were diagnosed. Emotional demands were examined as perceived and content-related emotional demands, individually reported and work-unit based. Support, meaningful work, and enrichment were considered as potential effect modifiers. RESULTS: Individually reported perceived emotional...

  9. Retail Demand Response in Southwest Power Pool

    Energy Technology Data Exchange (ETDEWEB)

    Bharvirkar, Ranjit; Heffner, Grayson; Goldman, Charles

    2009-01-30

    In 2007, the Southwest Power Pool (SPP) formed the Customer Response Task Force (CRTF) to identify barriers to deploying demand response (DR) resources in wholesale markets and develop policies to overcome these barriers. One of the initiatives of this Task Force was to develop more detailed information on existing retail DR programs and dynamic pricing tariffs, program rules, and utility operating practices. This report describes the results of a comprehensive survey conducted by LBNL in support of the Customer Response Task Force and discusses policy implications for integrating legacy retail DR programs and dynamic pricing tariffs into wholesale markets in the SPP region. LBNL conducted a detailed survey of existing DR programs and dynamic pricing tariffs administered by SPP's member utilities. Survey respondents were asked to provide information on advance notice requirements to customers, operational triggers used to call events (e.g. system emergencies, market conditions, local emergencies), use of these DR resources to meet planning reserves requirements, DR resource availability (e.g. seasonal, annual), participant incentive structures, and monitoring and verification (M&V) protocols. Nearly all of the 30 load-serving entities in SPP responded to the survey. Of this group, fourteen SPP member utilities administer 36 DR programs, five dynamic pricing tariffs, and six voluntary customer response initiatives. These existing DR programs and dynamic pricing tariffs have a peak demand reduction potential of 1,552 MW. Other major findings of this study are: o About 81percent of available DR is from interruptible rate tariffs offered to large commercial and industrial customers, while direct load control (DLC) programs account for ~;;14percent. o Arkansas accounts for ~;;50percent of the DR resources in the SPP footprint; these DR resources are primarily managed by cooperatives. o Publicly-owned cooperatives accounted for 54percent of the existing DR resources

  10. Sequential modulation of cue use in the task switching paradigm

    Directory of Open Access Journals (Sweden)

    Mike eWendt

    2012-08-01

    Full Text Available In task switching studies, pre-cuing of the upcoming task improves performance, indicating preparatory activation of the upcoming task set and/or inhibition of the previous task set. To further investigate cue-based task preparation, the authors presented both valid and invalid task cues in a task switching experiment involving three tasks. Consistent with previous findings, a validity effect in terms of higher reaction times on invalidly compared to validly cued tasks was obtained. However, this validity effect was reduced following invalidly cued trials, suggesting dynamic adjustment in terms of decreased cue-based preparation after being misled. Performance was particularly impaired when the current task was the one that was invalidly cued on the preceding trial. This finding may reflect either particular reluctance to prepare or persisting inhibition of the erroneously prepared task set from the pre-trial.

  11. Sequential Modulation of Cue Use in the Task Switching Paradigm

    Science.gov (United States)

    Wendt, Mike; Luna-Rodriguez, Aquiles; Reisenauer, Renate; Jacobsen, Thomas; Dreisbach, Gesine

    2012-01-01

    In task switching studies, pre-cuing of the upcoming task improves performance, indicating preparatory activation of the upcoming task-set, and/or inhibition of the previous task-set. To further investigate cue-based task preparation, the authors presented both valid and invalid task cues in a task switching experiment involving three tasks. Consistent with previous findings, a validity effect in terms of higher reaction times on invalidly compared to validly cued tasks was obtained. However, this validity effect was reduced following invalidly cued trials, suggesting dynamic adjustment in terms of decreased cue-based preparation after being misled. Performance was particularly impaired when the current task was the one that was invalidly cued on the preceding trial. This finding may reflect either particular reluctance to prepare or persisting inhibition of the erroneously prepared task-set from the pre-trial. PMID:22908004

  12. Trade Balance and Fuel Demand in Kosovo

    Directory of Open Access Journals (Sweden)

    Valon Kastrati

    2015-10-01

    Full Text Available AbstractGasoline and diesel are the main sources of fuel required for modern life and transportation, and the adjustment of gasoline and diesel prices has become a major public issue. The drastic fluctuations in recent international oil prices have affected retail gasoline and diesel prices also in the Western Balkan countries and prompted public opinion to question the pricing behaviors of oil companies. Kosovo, in the period of 17 years, has gone from a post-conflict  environment  into a state which is considered to be under transition. It has passed the reconstruction period by orienting itself toward the economic development  and European Integrations.  Price and income elasticities of gasoline demand show whether the price policy, pursued by the Kosovo government, can decrease the high gasoline consumption sufficiently or not. The high deficit of the current account of balance of payments is also a concern for the Kosovo’s economy; which is estimated up to 17.3% of the GDP after the foreign intervention.   The deficit of current account is being considered is related to the energy dependency. Therefore, in order to overcome such problems, control over the gasoline demand is needed to control the deficit of current accounts. Keywords:  oil price, economic development, imports, trade deficit.

  13. Latent factor structure of a behavioral economic marijuana demand curve.

    Science.gov (United States)

    Aston, Elizabeth R; Farris, Samantha G; MacKillop, James; Metrik, Jane

    2017-08-01

    Drug demand, or relative value, can be assessed via analysis of behavioral economic purchase task performance. Five demand indices are typically obtained from drug purchase tasks. The goal of this research was to determine whether metrics of marijuana reinforcement from a marijuana purchase task (MPT) exhibit a latent factor structure that efficiently characterizes marijuana demand. Participants were regular marijuana users (n = 99; 37.4% female, 71.5% marijuana use days [5 days/week], 15.2% cannabis dependent) who completed study assessments, including the MPT, during a baseline session. Principal component analysis was used to examine the latent structure underlying MPT indices. Concurrent validity was assessed via examination of relationships between latent factors and marijuana use, past quit attempts, and marijuana expectancies. A two-factor solution was confirmed as the best fitting structure, accounting for 88.5% of the overall variance. Factor 1 (65.8% variance) reflected "Persistence," indicating sensitivity to escalating marijuana price, which comprised four MPT indices (elasticity, O max, P max, and breakpoint). Factor 2 (22.7% variance) reflected "Amplitude," indicating the amount consumed at unrestricted price (intensity). Persistence factor scores were associated with fewer past marijuana quit attempts and lower expectancies of negative use outcomes. Amplitude factor scores were associated with more frequent use, dependence symptoms, craving severity, and positive marijuana outcome expectancies. Consistent with research on alcohol and cigarette purchase tasks, the MPT can be characterized with a latent two-factor structure. Thus, demand for marijuana appears to encompass distinct dimensions of price sensitivity and volumetric consumption, with differential relations to other aspects of marijuana motivation.

  14. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--90 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence.

  15. International Oil Supplies and Demands

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

    The eleventh Energy Modeling Forum (EMF) working group met four times over the 1989--1990 period to compare alternative perspectives on international oil supplies and demands through 2010 and to discuss how alternative supply and demand trends influence the world's dependence upon Middle Eastern oil. Proprietors of eleven economic models of the world oil market used their respective models to simulate a dozen scenarios using standardized assumptions. From its inception, the study was not designed to focus on the short-run impacts of disruptions on oil markets. Nor did the working group attempt to provide a forecast or just a single view of the likely future path for oil prices. The model results guided the group's thinking about many important longer-run market relationships and helped to identify differences of opinion about future oil supplies, demands, and dependence.

  16. Fundamental Travel Demand Model Example

    Science.gov (United States)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  17. Control and Optimization Meet the Smart Power Grid - Scheduling of Power Demands for Optimal Energy Management

    CERN Document Server

    Koutsopoulos, Iordanis

    2010-01-01

    The smart power grid aims at harnessing information and communication technologies to enhance reliability and enforce sensible use of energy. Its realization is geared by the fundamental goal of effective management of demand load. In this work, we envision a scenario with real-time communication between the operator and consumers. The grid operator controller receives requests for power demands from consumers, with different power requirement, duration, and a deadline by which it is to be completed. The objective is to devise a power demand task scheduling policy that minimizes the grid operational cost over a time horizon. The operational cost is a convex function of instantaneous power consumption and reflects the fact that each additional unit of power needed to serve demands is more expensive as demand load increases.First, we study the off-line demand scheduling problem, where parameters are fixed and known. Next, we devise a stochastic model for the case when demands are generated continually and sched...

  18. Water demand management research: A psychological perspective

    Science.gov (United States)

    Russell, Sally; Fielding, Kelly

    2010-05-01

    The availability of fresh water for human consumption is a critical global issue and one that will be exacerbated by the impacts of climate change. Water demand management has an important role to play in reducing the vulnerability of freshwater supplies to climate change impacts. In this paper, we argue that the field of psychology and environmental psychology in particular can make a vital contribution in understanding further the drivers of residential water demand. A growing body of literature in environmental psychology has examined the determinants of water conservation behavior, and this research has many potential applications for water demand policy. In this paper we offer a review of current psychological research that examines the five broad causes of residential water conservation behaviors: attitudes, beliefs, habits or routines, personal capabilities, and contextual factors. We assess how psychologists have studied water conservation behavior to date, identify shortcomings, and indicate how this research can be used to further promote residential water conservation and to inform evidence-based policy and practice.

  19. Managing electricity demand through dynamic pricing

    Science.gov (United States)

    Peddie, Robert A.; Bulleit, Douglas A.

    1985-11-01

    As electrical energy cannot be stored in large quantities with current technology, the energy balance of the electricity supply system has to be maintained continually by adjustments in supply to meet an unrestricted customer demand. Electricity over the projected peak tends to be very expensive, so utilities have sought to restrict demand during such periods to improve internal economic efficiency. The techniques used can be shown to be inefficient and disruptive if widely applied. Due to the way the utility and the regulators have homogenized costs, rate structures provide the customer no useful cost message as motivation to economically control utilization. Advances in microelectronics and communications remove these restrictions by allowing the customer to be informed continually of the cost of a kiloWatt hour (kWh) at the time of use. For the first time, the ensuing control of demand by the customer enables efficient utilization and simplifies the dynamic control of the electric system. This paper describes the method of formulating dynamic prices, the main elements and examples of the system, and how it can be introduced. The enumerated benefits show that greater customer satisfaction and improved economic management of the nation's resources and the utility's assets would result.

  20. Credit demand in Mozambican manufacturing

    DEFF Research Database (Denmark)

    Byiers, Bruce; Rand, John; Tarp, Finn

    2010-01-01

    manager education and business association membership are associated with whether a firm is credit constrained or not. Using our preferred measure of credit constraint suggests that around 43 per cent of the firms surveyed are constrained, and these enterprises would almost triple their debt burden......This paper uses two industrial firm surveys to identify the key determinants of credit demand in Mozambican manufacturing. We construct five different measures of being credit constrained and estimate desired debt demand. Besides firm size and ownership structure, we find evidence that general...

  1. Demand inducement as cheap talk.

    Science.gov (United States)

    Calcott, P

    1999-12-01

    The doctor-patient interaction is analysed in a game of cheap talk. Causes and consequences of imperfect agency are examined. One form of imperfect agency, supplier-induced demand, is a feature of neologism proof equilibria with some parameter values but not with others. The model is used to evaluate two tests that have been used to test for the existence of supplier-induced demand. The analysis suggests that the two tests, which compare the medical utilization of informed and uninformed consumers, are not valid.

  2. Satisfying the demand for financial information in public traded companies

    DEFF Research Database (Denmark)

    Holm, Claus

    A public traded company which wishes to comply with IAS standards and stock exchange requirements for full public disclosure of relevant information faces a major communication task. The Investor Relation policy of such a company has to satisfy a demand for financial information which seems...... and detailed information is, however, in stark contrast to reports on the demands by leading financial analysts. In the ongoing process of improving Investor Relation policies, the companies are often meet by financial analysts looking for condensed figures and tell-all financial ratios. This paper examines...... that Investor Relation policies are still made from a supply viewpoint, i.e., the perceived need for the company to provide specific information even when presenting the condensed information through key figures and financial ratios. There is no panacea in satisfying the demand for comparable financial figures....

  3. Demand-oriented traffic management for incidents and disasters

    OpenAIRE

    Flötteröd, Yun-Pang; Bieker, Laura

    2012-01-01

    Traffic simulation has been extensively used as a decision support tool for efficient traffic management in daily life. During disasters and incidents, traffic simulation can further help rescue teams to understand the current traffic state and the possible impacts of proposed strategies and then to make proper decisions. At this point, the changes in traffic demand should also be considered in the simulation to reflect the latest traffic state. In this paper, a demand-oriented traffic manage...

  4. Off-line simulation inspires insight: A neurodynamics approach to efficient robot task learning.

    Science.gov (United States)

    Sousa, Emanuel; Erlhagen, Wolfram; Ferreira, Flora; Bicho, Estela

    2015-12-01

    There is currently an increasing demand for robots able to acquire the sequential organization of tasks from social learning interactions with ordinary people. Interactive learning-by-demonstration and communication is a promising research topic in current robotics research. However, the efficient acquisition of generalized task representations that allow the robot to adapt to different users and contexts is a major challenge. In this paper, we present a dynamic neural field (DNF) model that is inspired by the hypothesis that the nervous system uses the off-line re-activation of initial memory traces to incrementally incorporate new information into structured knowledge. To achieve this, the model combines fast activation-based learning to robustly represent sequential information from single task demonstrations with slower, weight-based learning during internal simulations to establish longer-term associations between neural populations representing individual subtasks. The efficiency of the learning process is tested in an assembly paradigm in which the humanoid robot ARoS learns to construct a toy vehicle from its parts. User demonstrations with different serial orders together with the correction of initial prediction errors allow the robot to acquire generalized task knowledge about possible serial orders and the longer term dependencies between subgoals in very few social learning interactions. This success is shown in a joint action scenario in which ARoS uses the newly acquired assembly plan to construct the toy together with a human partner.

  5. 46 CFR 169.689 - Demand loads.

    Science.gov (United States)

    2010-10-01

    ... Electrical Electrical Installations on Vessels of 100 Gross Tons and Over § 169.689 Demand loads. Demand loads must meet § 111.60-7 of this chapter except that smaller demand loads for motor feeders...

  6. Influences of Obesity on Job Demands and Worker Capacity.

    Science.gov (United States)

    Cavuoto, Lora A; Nussbaum, Maury A

    2014-09-01

    Evidence suggests that the growing prevalence of obesity in the workforce has resulted in an increase in the incidence and cost of musculoskeletal injuries. Obesity can modify job demands and affect worker capacity in terms of anthropometry and occupational biomechanics, which may place workers at greater risk of injury. This paper presents a review of studies quantifying the work-relevant impacts of obesity, specifically related to work task demands, capacities, and their potential imbalance. The increased body fat that accompanies obesity leads to larger anthropometric dimensions and inertial parameters, particularly in the trunk and thigh areas. Consequently, individuals who are obese adjust their work postures and motions as an accommodation. These changes may affect the biomechanical demands on the joints and increase the burden on the musculoskeletal system. Independent of job demands, obesity-related differences also occur with respect to strength, fatigue, and task performance. Directions for future research are provided, focusing on the need for workplace redesign to account for changing workforce demographics.

  7. Process modelling in demand-driven supply chains: A reference model for the fruit industry

    NARCIS (Netherlands)

    Verdouw, C.N.; Beulens, A.J.M.; Trienekens, J.H.; Wolfert, J.

    2010-01-01

    The growing importance of health in consumption is expected to result in a significant increase of European fruit demand. However, the current fruit supply does not yet sufficiently meet demand requirements. This urges fruit supply chains to become more demand-driven, that is, able to continuously m

  8. Projected Demand and Potential Impacts to the National Airspace System of Autonomous, Electric, On-Demand Small Aircraft

    Science.gov (United States)

    Smith, Jeremy C.; Viken, Jeffrey K.; Guerreiro, Nelson M.; Dollyhigh, Samuel M.; Fenbert, James W.; Hartman, Christopher L.; Kwa, Teck-Seng; Moore, Mark D.

    2012-01-01

    Electric propulsion and autonomy are technology frontiers that offer tremendous potential to achieve low operating costs for small-aircraft. Such technologies enable simple and safe to operate vehicles that could dramatically improve regional transportation accessibility and speed through point-to-point operations. This analysis develops an understanding of the potential traffic volume and National Airspace System (NAS) capacity for small on-demand aircraft operations. Future demand projections use the Transportation Systems Analysis Model (TSAM), a tool suite developed by NASA and the Transportation Laboratory of Virginia Polytechnic Institute. Demand projections from TSAM contain the mode of travel, number of trips and geographic distribution of trips. For this study, the mode of travel can be commercial aircraft, automobile and on-demand aircraft. NASA's Airspace Concept Evaluation System (ACES) is used to assess NAS impact. This simulation takes a schedule that includes all flights: commercial passenger and cargo; conventional General Aviation and on-demand small aircraft, and operates them in the simulated NAS. The results of this analysis projects very large trip numbers for an on-demand air transportation system competitive with automobiles in cost per passenger mile. The significance is this type of air transportation can enhance mobility for communities that currently lack access to commercial air transportation. Another significant finding is that the large numbers of operations can have an impact on the current NAS infrastructure used by commercial airlines and cargo operators, even if on-demand traffic does not use the 28 airports in the Continental U.S. designated as large hubs by the FAA. Some smaller airports will experience greater demand than their current capacity allows and will require upgrading. In addition, in future years as demand grows and vehicle performance improves other non-conventional facilities such as short runways incorporated into

  9. A demand chain design for Chinese oatmeal companies

    Directory of Open Access Journals (Sweden)

    Haitao Wen

    2015-04-01

    Full Text Available Purpose: The purpose of this paper is to provide a demand chain design framework for Chinese small and medium enterprises in the oatmeal industry, to help them blaze a new trail in China's oatmeal market. Design/methodology/approach: The approach using in the demand chain design is extended Quality Function Development (QFD, which provides a communication tool so that designers can find a way to integrate customers’ needs into design chain. Findings: This paper illustrates an investigation of oatmeal consumed in China, and the result shows 9 factors influencing consumer’s purchasing decisions mostly. Then use these factors to design the demand chain, and the most important processes and tasks for the enterprises are come out from the fist and the second House of Quality (HOQ, which are the main part of the design. Finally, a demand chain design is completed. Research limitations/implications: It is an application of a demand chain design framework in real Chinese oatmeal market, but the data sample is limited. Consumption surveys should have more data sources with more detailed consumer groups. And the design model needs more real-life examples to verify Practical implications: Since oatmeal products industry develops rapidly in China, oatmeal market is becoming a vast bright market. And due to the low customer satisfaction of Chinese oatmeal market, it is crucial that companies can find a way to design their demand chain, so they can completely meet the needs. Originality/value: A demand chain design framework is presented with being specific to Chinese oatmeal market. It shows a real-life example of demand chain design, and provides the domestic oatmeal companies with an approach to compete in the market.

  10. Reward favours the prepared: incentive and task-informative cues interact to enhance attentional control

    Science.gov (United States)

    Chiew, Kimberly S.; Braver, Todd S.

    2015-01-01

    The dual mechanisms of control account suggests that cognitive control may be implemented through relatively proactive mechanisms in anticipation of stimulus onset, or through reactive mechanisms, triggered in response to changing stimulus demands. Reward incentives and task-informative cues (signaling the presence/absence of upcoming cognitive demand) have both been found to influence cognitive control in a proactive or preparatory fashion; yet, it is currently unclear whether and how such cue effects interact. We investigated this in two experiments using an adapted flanker paradigm, where task-informative and reward incentive cues were orthogonally manipulated on a trial-by-trial basis. In Experiment 1, results indicated that incentives not only speed RTs, but specifically reduce both interference and facilitation effects when combined with task-informative cues, suggesting enhanced proactive attentional control. Experiment 2 manipulated the timing of incentive cue information, demonstrating that such proactive control effects were only replicated with sufficient time to process the incentive cue (Early Incentive); when incentive signals were presented close to target onset (Late Incentive) the primary effect was a speed-accuracy tradeoff. Together, results suggest that advance cueing may trigger differing control strategies, and that these strategies may critically depend on both the timing – and the motivational incentive – to use such cues. PMID:26322689

  11. Demand Controlled Ventilation and Classroom Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  12. Voltage Controlled Dynamic Demand Response

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Mahat, Pukar

    2013-01-01

    . An adaptive dynamic model has been developed to determine composite voltage dependency of an aggregated load on feeder level. Following the demand dispatch or control signal, optimum voltage setting at the LV substation is determined based on the voltage dependency of the load. Furthermore, a new technique...

  13. The moral demands of affluence

    DEFF Research Database (Denmark)

    Sønderholm, Jørn

    2015-01-01

    In 2004, Garrett Cullity made a significant contribution to the literature on what the world’s relatively affluent owe to the world’s relatively poor through the publishing of The Moral Demands of Affluence. In this discussion note, I draw attention to a logical problem in Cullity’s master argument...

  14. Projecting Electricity Demand in 2050

    Energy Technology Data Exchange (ETDEWEB)

    Hostick, Donna J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Belzer, David B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hadley, Stanton W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Markel, Tony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Marnay, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kintner-Meyer, Michael C. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-07-01

    This paper describes the development of end-use electricity projections and load curves that were developed for the Renewable Electricity (RE) Futures Study (hereafter RE Futures), which explored the prospect of higher percentages (30% - 90%) of total electricity generation that could be supplied by renewable sources in the United States. As input to RE Futures, two projections of electricity demand were produced representing reasonable upper and lower bounds of electricity demand out to 2050. The electric sector models used in RE Futures required underlying load profiles, so RE Futures also produced load profile data in two formats: 8760 hourly data for the year 2050 for the GridView model, and in 2-year increments for 17 time slices as input to the Regional Energy Deployment System (ReEDS) model. The process for developing demand projections and load profiles involved three steps: discussion regarding the scenario approach and general assumptions, literature reviews to determine readily available data, and development of the demand curves and load profiles.

  15. Faculty Demand in Higher Education

    Science.gov (United States)

    Rosenthal, Danielle

    2007-01-01

    The objective of this study is to identify the factors that shift the demand curve for faculty at not-for-profit private institutions. It is unique in that to the author's knowledge no other study has directly addressed the question of how the positive correlation between average faculty salaries and faculty-student ratios can be reconciled with…

  16. The Cognitive Demands of Writing

    NARCIS (Netherlands)

    Torrance, Mark; Jeffery, Gaynor

    1999-01-01

    Writing is a complex activity that places demands on cognitive resources. This volume presents original theory and research exploring the ways in which the sub-components of the writing process (generating and organizing content, producing grammatical sentences, etc.) differ in their cognitive deman

  17. Market demands to Danish pork

    DEFF Research Database (Denmark)

    Bredahl, Lone

    2001-01-01

    . The study focuses on the development on the most important markets for Danish pork. The countries are Denmark, Japan, UK, Germany, Italy, France, USA, Russia and South Korea. The primary purpose is to identify market demands of importance to the Danish pork sector in order to maintain and strengthen its...

  18. Cotton Demand Dropping in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The ICAC claimed, global cotton market outlook is bleak in the 2012/2013 annual. Global cotton production is estimated at 25.9 million tons and cotton usage is estimated at 23.4 million tons. Cotton supply will exceed demand; the excess volume will reach 2.4 million tons.

  19. Demand as Frequency Controlled Reserve

    DEFF Research Database (Denmark)

    Xu, Zhao; Østergaard, Jacob; Togeby, Mikael

    2011-01-01

    Relying on generation side alone is deemed insufficient to fulfill the system balancing needs for future Danish power system, where a 50% wind penetration is outlined by the government for year 2025. This paper investigates using the electricity demand as frequency controlled reserve (DFR) as a new...

  20. Employer Demands from Business Graduates

    Science.gov (United States)

    McMurray, Stephen; Dutton, Matthew; McQuaid, Ronald; Richard, Alec

    2016-01-01

    Purpose: The purpose of this paper is to report on research carried out with employers to determine demand for business and management skills in the Scottish workforce. Design/methodology/approach: The research used a questionnaire in which employers were interviewed (either telephone or face to face), completed themselves and returned by e-mail,…

  1. Anterior medial prefrontal cortex exhibits activation during task preparation but deactivation during task execution.

    Directory of Open Access Journals (Sweden)

    Hideya Koshino

    Full Text Available BACKGROUND: The anterior prefrontal cortex (PFC exhibits activation during some cognitive tasks, including episodic memory, reasoning, attention, multitasking, task sets, decision making, mentalizing, and processing of self-referenced information. However, the medial part of anterior PFC is part of the default mode network (DMN, which shows deactivation during various goal-directed cognitive tasks compared to a resting baseline. One possible factor for this pattern is that activity in the anterior medial PFC (MPFC is affected by dynamic allocation of attentional resources depending on task demands. We investigated this possibility using an event related fMRI with a face working memory task. METHODOLOGY/PRINCIPAL FINDINGS: Sixteen students participated in a single fMRI session. They were asked to form a task set to remember the faces (Face memory condition or to ignore them (No face memory condition, then they were given 6 seconds of preparation period before the onset of the face stimuli. During this 6-second period, four single digits were presented one at a time at the center of the display, and participants were asked to add them and to remember the final answer. When participants formed a task set to remember faces, the anterior MPFC exhibited activation during a task preparation period but deactivation during a task execution period within a single trial. CONCLUSIONS/SIGNIFICANCE: The results suggest that the anterior MPFC plays a role in task set formation but is not involved in execution of the face working memory task. Therefore, when attentional resources are allocated to other brain regions during task execution, the anterior MPFC shows deactivation. The results suggest that activation and deactivation in the anterior MPFC are affected by dynamic allocation of processing resources across different phases of processing.

  2. Category learning in older adulthood: A study of the Shepard, Hovland, and Jenkins (1961) tasks.

    Science.gov (United States)

    Rabi, Rahel; Minda, John Paul

    2016-03-01

    Shepard, Hovland, and Jenkins (1961) examined the categorization abilities of younger adults using tasks involving single-dimensional rule learning, disjunctive rule learning, and family resemblance learning. The current study examined category learning in older adults using this well-known category set. Older adults, like younger adults, found category tasks with a single relevant dimension the easiest to learn. In contrast to younger adults, older adults found complex disjunctive rule-based categories harder to learn than family resemblance based categories. Disjunctive rule-based category learning appeared to be the most difficult for older adults to learn because this category set placed the heaviest demands on working memory, which is known to be a cognitive function that declines with normal aging. The authors discuss why complex rule-based category learning is considered more difficult for older adults to learn relative to younger adults, drawing parallels to developmental research.

  3. Attention and Inhibition in Bilingual Children: Evidence from the Dimensional Change Card Sort Task

    Science.gov (United States)

    Bialystok, Ellen; Martin, Michelle M.

    2004-01-01

    In a previous study, a bilingual advantage for preschool children in solving the dimensional change card sort task was attributed to superiority in inhibition of attention (Bialystok, 1999). However, the task includes difficult representational demands to encode and interpret the task stimuli, and bilinguals may also have profited from superior…

  4. Following the time course of face gender and expression processing: a task-dependent ERP study.

    Science.gov (United States)

    Valdés-Conroy, Berenice; Aguado, Luis; Fernández-Cahill, María; Romero-Ferreiro, Verónica; Diéguez-Risco, Teresa

    2014-05-01

    The effects of task demands and the interaction between gender and expression in face perception were studied using event-related potentials (ERPs). Participants performed three different tasks with male and female faces that were emotionally inexpressive or that showed happy or angry expressions. In two of the tasks (gender and expression categorization) facial properties were task-relevant while in a third task (symbol discrimination) facial information was irrelevant. Effects of expression were observed on the visual P100 component under all task conditions, suggesting the operation of an automatic process that is not influenced by task demands. The earliest interaction between expression and gender was observed later in the face-sensitive N170 component. This component showed differential modulations by specific combinations of gender and expression (e.g., angry male vs. angry female faces). Main effects of expression and task were observed in a later occipito-temporal component peaking around 230 ms post-stimulus onset (EPN or early posterior negativity). Less positive amplitudes in the presence of angry faces and during performance of the gender and expression tasks were observed. Finally, task demands also modulated a positive component peaking around 400 ms (LPC, or late positive complex) that showed enhanced amplitude for the gender task. The pattern of results obtained here adds new evidence about the sequence of operations involved in face processing and the interaction of facial properties (gender and expression) in response to different task demands. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Conjunctive Continuous Performance Task (CCPT)--A Pure Measure of Sustained Attention

    Science.gov (United States)

    Shalev, Lilach; Ben-Simon, Anat; Mevorach, Carmel; Cohen, Yoav; Tsal, Yehoshua

    2011-01-01

    Among the large variety of attentional tasks that have been used to study sustained attention, the Continuous Performance Task (CPT) is perhaps the most widely used. Despite substantial differences in task characteristics and demands, all CPT paradigms have been referred to as measures of sustained attention. In the present study we introduce a…

  6. Comparison of the Working Memory Load in N-Back and Working Memory Span Tasks by Means of EEG Frequency Band Power and P300 Amplitude.

    Science.gov (United States)

    Scharinger, Christian; Soutschek, Alexander; Schubert, Torsten; Gerjets, Peter

    2017-01-01

    According to theoretical accounts, both, N-back and complex span tasks mainly require working memory (WM) processing. In contrast, simple span tasks conceptually mainly require WM storage. Thus, conceptually, an N-back task and a complex span task share more commonalities as compared to a simple span task. In the current study, we compared an N-back task, a complex operation span task (Ospan), and a simple digit span task (Dspan) by means of typical WM load-related measures of the Electroencephalogram (EEG) like the parietal alpha and beta frequency band power, the frontal theta frequency band power, and the P300 amplitude, to examine whether these tasks would show commonalities or differences in WM processing-load. We expected that increasing WM-load would generally lead to a decreased alpha and beta frequency band power, an increased theta frequency band power, and a decreased P300 amplitude. Yet, based on the conceptual considerations, we hypothesized that the outcomes of these measures would be more comparable between the N-back and the Ospan as compared to the Dspan. Our hypotheses were partly confirmed. The N-back and the Ospan showed timely more prolonged alpha frequency band power effects as compared to the Dspan. This might indicate higher demands on WM processing in the former two tasks. The theta frequency band power and the P300 amplitude were most pronounced in the N-back task as compared to both span tasks. This might indicate specific demands on cognitive control in the N-back task. Additionally, we observed that behavioral performance measures correlated with changes in EEG alpha power of the N-back and the Ospan, yet not of the Dspan. Taken together, the hypothesized conceptual commonalities between the N-back task and the Ospan (and, for the Dspan, differences) were only partly confirmed by the electrophysiological WM load-related measures, indicating a potential need for reconsidering the theoretical accounts on WM tasks and the value of a closer

  7. Comparison of the Working Memory Load in N-Back and Working Memory Span Tasks by Means of EEG Frequency Band Power and P300 Amplitude

    Science.gov (United States)

    Scharinger, Christian; Soutschek, Alexander; Schubert, Torsten; Gerjets, Peter

    2017-01-01

    According to theoretical accounts, both, N-back and complex span tasks mainly require working memory (WM) processing. In contrast, simple span tasks conceptually mainly require WM storage. Thus, conceptually, an N-back task and a complex span task share more commonalities as compared to a simple span task. In the current study, we compared an N-back task, a complex operation span task (Ospan), and a simple digit span task (Dspan) by means of typical WM load-related measures of the Electroencephalogram (EEG) like the parietal alpha and beta frequency band power, the frontal theta frequency band power, and the P300 amplitude, to examine whether these tasks would show commonalities or differences in WM processing-load. We expected that increasing WM-load would generally lead to a decreased alpha and beta frequency band power, an increased theta frequency band power, and a decreased P300 amplitude. Yet, based on the conceptual considerations, we hypothesized that the outcomes of these measures would be more comparable between the N-back and the Ospan as compared to the Dspan. Our hypotheses were partly confirmed. The N-back and the Ospan showed timely more prolonged alpha frequency band power effects as compared to the Dspan. This might indicate higher demands on WM processing in the former two tasks. The theta frequency band power and the P300 amplitude were most pronounced in the N-back task as compared to both span tasks. This might indicate specific demands on cognitive control in the N-back task. Additionally, we observed that behavioral performance measures correlated with changes in EEG alpha power of the N-back and the Ospan, yet not of the Dspan. Taken together, the hypothesized conceptual commonalities between the N-back task and the Ospan (and, for the Dspan, differences) were only partly confirmed by the electrophysiological WM load-related measures, indicating a potential need for reconsidering the theoretical accounts on WM tasks and the value of a closer

  8. Design of demand side response model in energy internet demonstration park

    Science.gov (United States)

    Zhang, Q.; Liu, D. N.

    2017-08-01

    The implementation of demand side response can bring a lot of benefits to the power system, users and society, but there are still many problems in the actual operation. Firstly, this paper analyses the current situation and problems of demand side response. On this basis, this paper analyses the advantages of implementing demand side response in the energy Internet demonstration park. Finally, the paper designs three kinds of feasible demand side response modes in the energy Internet demonstration park.

  9. Addressing Energy Demand through Demand Response. International Experiences and Practices

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ghatikar, Girish [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ni, Chun Chun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dudley, Junqiao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Martin, Phil [Enernoc, Inc., Boston, MA (United States); Wikler, Greg

    2012-06-01

    Demand response (DR) is a load management tool which provides a cost-effective alternative to traditional supply-side solutions to address the growing demand during times of peak electrical load. According to the US Department of Energy (DOE), demand response reflects “changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity over time, or to incentive payments designed to induce lower electricity use at times of high wholesale market prices or when system reliability is jeopardized.” 1 The California Energy Commission (CEC) defines DR as “a reduction in customers’ electricity consumption over a given time interval relative to what would otherwise occur in response to a price signal, other financial incentives, or a reliability signal.” 2 This latter definition is perhaps most reflective of how DR is understood and implemented today in countries such as the US, Canada, and Australia where DR is primarily a dispatchable resource responding to signals from utilities, grid operators, and/or load aggregators (or DR providers).

  10. Home Network Technologies and Automating Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    McParland, Charles

    2009-12-01

    Over the past several years, interest in large-scale control of peak energy demand and total consumption has increased. While motivated by a number of factors, this interest has primarily been spurred on the demand side by the increasing cost of energy and, on the supply side by the limited ability of utilities to build sufficient electricity generation capacity to meet unrestrained future demand. To address peak electricity use Demand Response (DR) systems are being proposed to motivate reductions in electricity use through the use of price incentives. DR systems are also be design to shift or curtail energy demand at critical times when the generation, transmission, and distribution systems (i.e. the 'grid') are threatened with instabilities. To be effectively deployed on a large-scale, these proposed DR systems need to be automated. Automation will require robust and efficient data communications infrastructures across geographically dispersed markets. The present availability of widespread Internet connectivity and inexpensive, reliable computing hardware combined with the growing confidence in the capabilities of distributed, application-level communications protocols suggests that now is the time for designing and deploying practical systems. Centralized computer systems that are capable of providing continuous signals to automate customers reduction of power demand, are known as Demand Response Automation Servers (DRAS). The deployment of prototype DRAS systems has already begun - with most initial deployments targeting large commercial and industrial (C & I) customers. An examination of the current overall energy consumption by economic sector shows that the C & I market is responsible for roughly half of all energy consumption in the US. On a per customer basis, large C & I customers clearly have the most to offer - and to gain - by participating in DR programs to reduce peak demand. And, by concentrating on a small number of relatively

  11. Future land-use related water demand in California

    Science.gov (United States)

    Wilson, Tamara; Sleeter, Benjamin M.; Cameron, D. Richard

    2016-01-01

    Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters(+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

  12. Future land-use related water demand in California

    Science.gov (United States)

    Wilson, Tamara S.; Sleeter, Benjamin M.; Cameron, D. Richard

    2016-05-01

    Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters (+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

  13. Interrelationships between marijuana demand and discounting of delayed rewards: Convergence in behavioral economic methods.

    Science.gov (United States)

    Aston, Elizabeth R; Metrik, Jane; Amlung, Michael; Kahler, Christopher W; MacKillop, James

    2016-12-01

    Distinct behavioral economic domains, including high perceived drug value (demand) and delay discounting (DD), have been implicated in the initiation of drug use and the progression to dependence. However, it is unclear whether frequent marijuana users conform to a "reinforcer pathology" addiction model wherein marijuana demand and DD jointly increase risk for problematic marijuana use and cannabis dependence (CD). Participants (n=88, 34% female, 14% cannabis dependent) completed a marijuana purchase task at baseline. A delay discounting task was completed following placebo marijuana cigarette (0% THC) administration during a separate experimental session. Marijuana demand and DD were quantified using area under the curve (AUC). In multiple regression models, demand uniquely predicted frequency of marijuana use while DD did not. In contrast, DD uniquely predicted CD symptom count while demand did not. There were no significant interactions between demand and DD in either model. These findings suggest that frequent marijuana users exhibit key constituents of the reinforcer pathology model: high marijuana demand and steep discounting of delayed rewards. However, demand and DD appear to be independent rather than synergistic risk factors for elevated marijuana use and risk for progression to CD. Findings also provide support for using AUC as a singular marijuana demand metric, particularly when also examining other behavioral economic constructs that apply similar statistical approaches, such as DD, to support analytic methodological convergence. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. IEA Wind Task 36 Forecasting

    Science.gov (United States)

    Giebel, Gregor; Cline, Joel; Frank, Helmut; Shaw, Will; Pinson, Pierre; Hodge, Bri-Mathias; Kariniotakis, Georges; Sempreviva, Anna Maria; Draxl, Caroline

    2017-04-01

    Wind power forecasts have been used operatively for over 20 years. Despite this fact, there are still several possibilities to improve the forecasts, both from the weather prediction side and from the usage of the forecasts. The new International Energy Agency (IEA) Task on Wind Power Forecasting tries to organise international collaboration, among national weather centres with an interest and/or large projects on wind forecast improvements (NOAA, DWD, UK MetOffice, …) and operational forecaster and forecast users. The Task is divided in three work packages: Firstly, a collaboration on the improvement of the scientific basis for the wind predictions themselves. This includes numerical weather prediction model physics, but also widely distributed information on accessible datasets for verification. Secondly, we will be aiming at an international pre-standard (an IEA Recommended Practice) on benchmarking and comparing wind power forecasts, including probabilistic forecasts aiming at industry and forecasters alike. This WP will also organise benchmarks, in cooperation with the IEA Task WakeBench. Thirdly, we will be engaging end users aiming at dissemination of the best practice in the usage of wind power predictions, especially probabilistic ones. The Operating Agent is Gregor Giebel of DTU, Co-Operating Agent is Joel Cline of the US Department of Energy. Collaboration in the task is solicited from everyone interested in the forecasting business. We will collaborate with IEA Task 31 Wakebench, which developed the Windbench benchmarking platform, which this task will use for forecasting benchmarks. The task runs for three years, 2016-2018. Main deliverables are an up-to-date list of current projects and main project results, including datasets which can be used by researchers around the world to improve their own models, an IEA Recommended Practice on performance evaluation of probabilistic forecasts, a position paper regarding the use of probabilistic forecasts

  15. DataBase on demand

    CERN Document Server

    Aparicio, Ruben Gaspar; Coterillo Coz, I

    2012-01-01

    At CERN a number of key database applications are running on user-managed MySQL database services. The database on demand project was born out of an idea to provide the CERN user community with an environment to develop and run database services outside of the actual centralised Oracle based database services. The Database on Demand (DBoD) empowers the user to perform certain actions that had been traditionally done by database administrators, DBA's, providing an enterprise platform for database applications. It also allows the CERN user community to run different database engines, e.g. presently open community version of MySQL and single instance Oracle database server. This article describes a technology approach to face this challenge, a service level agreement, the SLA that the project provides, and an evolution of possible scenarios.

  16. DataBase on Demand

    Science.gov (United States)

    Gaspar Aparicio, R.; Gomez, D.; Coterillo Coz, I.; Wojcik, D.

    2012-12-01

    At CERN a number of key database applications are running on user-managed MySQL database services. The database on demand project was born out of an idea to provide the CERN user community with an environment to develop and run database services outside of the actual centralised Oracle based database services. The Database on Demand (DBoD) empowers the user to perform certain actions that had been traditionally done by database administrators, DBA's, providing an enterprise platform for database applications. It also allows the CERN user community to run different database engines, e.g. presently open community version of MySQL and single instance Oracle database server. This article describes a technology approach to face this challenge, a service level agreement, the SLA that the project provides, and an evolution of possible scenarios.

  17. Energy demand modeling for Uzbekistan

    Directory of Open Access Journals (Sweden)

    Bobur Khodjaev

    2012-05-01

    Full Text Available The paper is devoted to energy demand forecasting in Uzbekistan. Studies show that in spite of the abundant reserves of hydrocarbons, low energy efficiency can have an adverse impact on energy security in Uzbekistan in the future. Oil and gas are the main primary energy source and they ensure energy security of Uzbekistan. Energy demand forecasting is essential in order to develop an effective energy policy. Such forecast can be useful to plan oil and gas production volumes, to identify priorities for the industrial modernization and to create favorable conditions for sustainable economic development in the future. Author proposes model based on translog function for developing medium-and long-term development programs in energy sector and the modernization and technological re-equipment of industry.

  18. Resource pre-allocation algorithms for low-energy task scheduling of cloud computing

    Institute of Scientific and Technical Information of China (English)

    Xiaolong Xu; Lingling Cao; Xinheng Wang

    2016-01-01

    In order to lower the power consumption and im-prove the coefficient of resource utilization of current cloud computing systems, this paper proposes two resource pre-alocation algorithms based on the “shut down the re-dundant, turn on the demanded” strategy here. Firstly, a green cloud computing model is presented, abstracting the task scheduling problem to the virtual machine deployment issue with the virtualization technology. Secondly, the future work-loads of system need to be predicted: a cubic exponential smoothing algorithm based on the conservative control (CESCC) strategy is proposed, combining with the current state and resource distribution of system, in order to calculate the demand of resources for the next period of task requests. Then, a multi-objective constrained optimization model of power consumption and a low-energy resource alocation algorithm based on probabilistic matching (RA-PM) are pro-posed. In order to reduce the power consumption further, the resource alocation algorithm based on the improved simu-lated annealing (RA-ISA) is designed with the improved simulated annealing algorithm. Experimental results show that the prediction and conservative control strategy make re-source pre-alocation catch up with demands, and improve the efficiency of real-time response and the stability of the system. Both RA-PM and RA-ISA can activate fewer hosts, achieve better load balance among the set of high applicable hosts, maximize the utilization of resources, and greatly reduce the power consumption of cloud computing systems.

  19. Disruptive innovation: the demand side.

    Science.gov (United States)

    Havighurst, Clark C

    2008-01-01

    The notion of disruptive innovation provides a welcome framework for considering the prospects for low-cost alternatives in American medicine. Such innovations as have been seen, however, are largely the result of demand by patients paying their own bills because they have high-deductible coverage or are uninsured. Many other cost-saving innovations are discouraged by financing systems that are themselves largely immune to competition from disruptive innovators.

  20. Demand controlled ventilation; Behovsstyrt ventilasjon

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Henning Holm

    2006-07-01

    The terms CAV and VAV have been known terms for many years in the ventilation business. The terms are also included in building regulations, but the time is now right to focus on demand controlled ventilation (DCV). The new building regulations and the accompanying energy framework underline the need for a more nuanced thinking when it comes to controlling ventilation systems. Descriptions and further details of the ventilation systems are provided (ml)

  1. Fish demand and supply projections

    OpenAIRE

    Sverdrup-Jensen, S.

    1997-01-01

    It has been predicted that the global demand for fish for human consumption will increase by more than 50% over the next 15 years. The FAO has projected that the increase in supply will originate primarily from marine fisheries, aquaculture and to a lesser extent from inland fisheries, but with a commensurate price increase. However, there are constraints to increased production in both marine and inland fisheries, such as overfishing, overexploitation limited potential increase and environme...

  2. Investigating Comparative Advantages of Advance Demand Information in Presence of Heterogeneous Demand

    DEFF Research Database (Denmark)

    Du, Bisheng; Larsen, Christian

    The paper studies aspects of advance demand information and heterogeneous demand in a mathematical model of an inventory system. The concept advance demand information is that customers ahead in time of actual demand place their orders. The concept heterogeneous demand refers to that there are di......The paper studies aspects of advance demand information and heterogeneous demand in a mathematical model of an inventory system. The concept advance demand information is that customers ahead in time of actual demand place their orders. The concept heterogeneous demand refers...

  3. Energy demand and population change.

    Science.gov (United States)

    Allen, E L; Edmonds, J A

    1981-09-01

    During the post World War 2 years energy consumption has grown 136% while population grew about 51%; per capita consumption of energy expanded, therefore, about 60%. For a given population size, demographic changes mean an increase in energy needs; for instance the larger the group of retirement age people, the smaller their energy needs than are those for a younger group. Estimates indicate that by the year 2000 the energy impact will be toward higher per capita consumption with 60% of the population in the 19-61 age group of workers. Rising female labor force participation will increase the working group even more; it has also been found that income and energy grow at a proportional rate. The authors predict that gasoline consumption within the US will continue to rise with availability considering the larger number of female drivers and higher per capita incomes. The flow of illegal aliens (750,000/year) will have a major impact on income and will use greater amounts of energy than can be expected. A demographic change which will lower energy demands will be the slowdown of the rate of household formation caused by the falling number of young adults. The response of energy demand to price changes is small and slow but incomes play a larger role as does the number of personal automobiles and social changes affecting household formation. Households, commercial space, transportation, and industry are part of every demand analysis and population projections play a major role in determining these factors.

  4. Flow based vs. demand based energy-water modelling

    Science.gov (United States)

    Rozos, Evangelos; Nikolopoulos, Dionysis; Efstratiadis, Andreas; Koukouvinos, Antonios; Makropoulos, Christos

    2015-04-01

    The water flow in hydro-power generation systems is often used downstream to cover other type of demands like irrigation and water supply. However, the typical case is that the energy demand (operation of hydro-power plant) and the water demand do not coincide. Furthermore, the water inflow into a reservoir is a stochastic process. Things become more complicated if renewable resources (wind-turbines or photovoltaic panels) are included into the system. For this reason, the assessment and optimization of the operation of hydro-power systems are challenging tasks that require computer modelling. This modelling should not only simulate the water budget of the reservoirs and the energy production/consumption (pumped-storage), but should also take into account the constraints imposed by the natural or artificial water network using a flow routing algorithm. HYDRONOMEAS, for example, uses an elegant mathematical approach (digraph) to calculate the flow in a water network based on: the demands (input timeseries), the water availability (simulated) and the capacity of the transmission components (properties of channels, rivers, pipes, etc.). The input timeseries of demand should be estimated by another model and linked to the corresponding network nodes. A model that could be used to estimate these timeseries is UWOT. UWOT is a bottom up urban water cycle model that simulates the generation, aggregation and routing of water demand signals. In this study, we explore the potentials of UWOT in simulating the operation of complex hydrosystems that include energy generation. The evident advantage of this approach is the use of a single model instead of one for estimation of demands and another for the system simulation. An application of UWOT in a large scale system is attempted in mainland Greece in an area extending over 130×170 km². The challenges, the peculiarities and the advantages of this approach are examined and critically discussed.

  5. Scalable video on demand adaptive Internet-based distribution

    CERN Document Server

    Zink, Michael

    2013-01-01

    In recent years, the proliferation of available video content and the popularity of the Internet have encouraged service providers to develop new ways of distributing content to clients. Increasing video scaling ratios and advanced digital signal processing techniques have led to Internet Video-on-Demand applications, but these currently lack efficiency and quality. Scalable Video on Demand: Adaptive Internet-based Distribution examines how current video compression and streaming can be used to deliver high-quality applications over the Internet. In addition to analysing the problems

  6. Mental fatigue modulates dynamic adaptation to perceptual demand in speeded detection.

    Directory of Open Access Journals (Sweden)

    Robert Langner

    Full Text Available When stimulus intensity in simple reaction-time tasks randomly varies across trials, detection speed usually improves after a low-intensity trial. With auditory stimuli, this improvement was often found to be asymmetric, being greater on current low-intensity trials. Our study investigated (1 whether asymmetric sequential intensity adaptation also occurs with visual stimuli; (2 whether these adjustments reflect decision-criterion shifts or, rather, a modulation of perceptual sensitivity; and (3 how sequential intensity adaptation and its underlying mechanisms are affected by mental fatigue induced through prolonged performance. In a continuous speeded detection task with randomly alternating high- and low-intensity visual stimuli, the reaction-time benefit after low-intensity trials was greater on subsequent low- than high-intensity trials. This asymmetry, however, only developed with time on task (TOT. Signal-detection analyses showed that the decision criterion transiently became more liberal after a low-intensity trial, whereas observer sensitivity increased when the preceding and current stimulus were of equal intensity. TOT-induced mental fatigue only affected sensitivity, which dropped more on low- than on high-intensity trials. This differential fatigue-related sensitivity decrease selectively enhanced the impact of criterion down-shifts on low-intensity trials, revealing how the interplay of two perceptual mechanisms and their modulation by fatigue combine to produce the observed overall pattern of asymmetric performance adjustments to varying visual intensity in continuous speeded detection. Our results have implications for similar patterns of sequential demand adaptation in other cognitive domains as well as for real-world prolonged detection performance.

  7. Study on Customer Demands for Product Innovation

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; YANG Mingzhong; LI Yibing; LI Jun

    2006-01-01

    In order to improve the satisfaction degree of customers' individual demands for products and reduce the risk of the product innovation, the characteristics of customer demands for product innovation are analyzed, and the type and content of customer demands are discussed. Then the framework of customer demands acquisition for product innovation is established. Finally, the prototype system of customer demands information acquisition and product customization for product innovation which takes mobile phone as the example is developed successfully.

  8. Comparing elite soldiers' perceptions of psychological and physical demands during military training.

    Science.gov (United States)

    Thomas, Jeffrey L; Adler, Amy B; Wittels, Peter; Enne, Robert; Johannes, Bernd

    2004-07-01

    This research examined the impact of psychological and physical demands on a group of elite soldiers (N = 9) before, during and after training exercises involving routine and unrehearse tasks. Based on the psychological concept of toughening, we expected soldier responses to unrehearsed demands to be les resilient than to routine training demands. As hypothesized soldiers rated their perceptions of physical and psychologica demands higher during the unrehearsed training phase of the study. It was also hypothesized that soldiers would recover more from physical demands than from psychological de mands after the training exercise. Although a trend in the data marginally supported this hypothesis, a note of caution is warranted because of the small sample size. Limitations and implications of the study are discussed, with particular emphasis on the dual importance of psychological and physical training in preparing soldiers for mission demands.

  9. What Task Designers Do.

    Science.gov (United States)

    Johnson, Keith

    2000-01-01

    Describes a research project that is concerned with the design procedures followed by those engaged in designing pedagogic tasks for use in classrooms. Focuses on the part of the project that involves actual observation of designers in the process of developing one specific task for class use. Findings are presented under three headers: control…

  10. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks, is fragme......There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, and recommendations, and supporting exploratory search to sensemaking and analytics, UI and UX design pose an overconstrained challenge. How do we know that our approach is any good? Supporting complex search task requires new collaborations across the whole field of IR, and the proposed workshop will bring together...

  11. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo;

    2015-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...... introductory to specialized, and from authoritative to speculative or opinionated, when to show what sources of information? How does the information seeking process evolve and what are relevant differences between different stages? With complex task and search process management, blending searching, browsing...

  12. Is seeking bad mood cognitively demanding? Contra-hedonic orientation and working-memory capacity in everyday life.

    Science.gov (United States)

    Riediger, Michaela; Wrzus, Cornelia; Schmiedek, Florian; Wagner, Gert G; Lindenberger, Ulman

    2011-06-01

    Hedonism, or wanting to feel good, is central to human motivation. At times, however, people also seek to maintain or enhance negative affect or to dampen positive affect, and this can be instrumental for the later attainment of their goals. Here, we investigate the assumption that such contra-hedonic orientation is cognitively more demanding than prohedonic orientation, above and beyond the effects of momentary affective experience. We provided 378 participants with mobile phones that they carried with them for 3 weeks while pursuing their daily routines. The phones prompted participants at least 54 times to report their current affect-regulation orientation and to work on two trials of a cognitively demanding working memory task. As expected, contra-hedonic orientation was substantially less prevalent than prohedonic orientation. It was reported in 15% of the measurement occasions. Participants who reported on average more contra-hedonic orientation showed lower average working memory performance throughout the study interval. Further, controlling for the effects of accompanying affective experiences, momentary occurrences of contra-hedonic orientation were associated with temporary declines in working memory performance within individuals, and this could neither be explained by lacking task compliance nor by other characteristics of the individual or the situation. Prohedonic orientation showed a considerably smaller association with working memory performance. These findings are consistent with the view that contra-hedonic orientation is accompanied by momentarily more diminished cognitive resources than is prohedonic orientation.

  13. Profile-Matching Techniques for On-Demand Software Management in Sensor Networks

    Directory of Open Access Journals (Sweden)

    Falko Dressler

    2007-03-01

    Full Text Available The heterogeneity and dynamics in terms of hardware and software configurations are steadily increasing in wireless sensor networks (WSNs. Therefore, software management is becoming one of the most prominent challenges in this domain. This applies especially for on-demand updates for improved redundancy or adaptive task allocation. Methodologies for efficient software management in WSN need to be investigated for operating and maintaining large-scale sensor networks. We developed a profile-based software management scheme that consists of a dynamic profile-matching algorithm to identify current hardware and software configurations, an on-demand code generation module, and mechanisms for dynamic network-centric reprogramming of sensor nodes. We exploit the advantages of robot-based reconfiguration and reprogramming methods for efficient and secure software management. The mobile robot system is employed for decision processes and to store the source code repository. The developed methods are depicted in detail. Additionally, we demonstrate the applicability and advantages based on a scenario that we implemented in our lab.

  14. Profile-Matching Techniques for On-Demand Software Management in Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dressler Falko

    2007-01-01

    Full Text Available The heterogeneity and dynamics in terms of hardware and software configurations are steadily increasing in wireless sensor networks (WSNs. Therefore, software management is becoming one of the most prominent challenges in this domain. This applies especially for on-demand updates for improved redundancy or adaptive task allocation. Methodologies for efficient software management in WSN need to be investigated for operating and maintaining large-scale sensor networks. We developed a profile-based software management scheme that consists of a dynamic profile-matching algorithm to identify current hardware and software configurations, an on-demand code generation module, and mechanisms for dynamic network-centric reprogramming of sensor nodes. We exploit the advantages of robot-based reconfiguration and reprogramming methods for efficient and secure software management. The mobile robot system is employed for decision processes and to store the source code repository. The developed methods are depicted in detail. Additionally, we demonstrate the applicability and advantages based on a scenario that we implemented in our lab.

  15. Task-specific dystonia: pathophysiology and management.

    Science.gov (United States)

    Sadnicka, Anna; Kassavetis, Panagiotis; Pareés, Isabel; Meppelink, Anne Marthe; Butler, Katherine; Edwards, Mark

    2016-09-01

    Task-specific dystonia is a form of isolated focal dystonia with the peculiarity of being displayed only during performance of a specific skilled motor task. This distinctive feature makes task-specific dystonia a particularly mysterious and fascinating neurological condition. In this review, we cover phenomenology and its increasingly broad-spectrum risk factors for the disease, critically review pathophysiological theories and evaluate current therapeutic options. We conclude by highlighting the unique features of task-specific dystonia within the wider concept of dystonia. We emphasise the central contribution of environmental risk factors, and propose a model by which these triggers may impact on the motor control of skilled movement. By viewing task-specific dystonia through this new lens which considers the disorder a modifiable disorder of motor control, we are optimistic that research will yield novel therapeutic avenues for this highly motivated group of patients.

  16. Trait Mindfulness and Cognitive Task Performance

    Directory of Open Access Journals (Sweden)

    Emalee J. W. Quickel

    2014-11-01

    Full Text Available Mindfulness meditation (MM training has been shown to have positive effects on working memory and focused attention tasks. Clarifying the construct of mindfulness is important so that mindfulness can be studied effectively in individual differences and cognition research. The current study tested whether trait mindfulness alone explains any of the variability on task performance. Five commonly used mindfulness scales, as well as six standardized and experimental attention and working memory tasks were administered to 164 participants with no meditation experience. Confirmatory factor analysis found that the common variance denoted by measures of trait mindfulness is unrelated to the common variance among tasks requiring focused attention. These results indicate that mindfulness scales may not be capturing the attentional aspects of mindfulness. Individuals who score high on mindfulness scales do not perform better on focused attention tasks than those who score lower on mindfulness scales. These results have implications for defining and operationalizing mindfulness.

  17. Demand chain management – The implementation

    Directory of Open Access Journals (Sweden)

    D Ericsson

    2011-12-01

    Full Text Available Most current supply chain models were developed during a period of relative stability. Today, the environment is discontinuous, volatile and unpredictable. This requires a major rethinking and revitalisation of existing supply chain models. Supply chains are much more than warehouses, transportation and technology, they are people powered and have to be treated as social and political as well as economic and technical systems.The most difficult yet challenging and rewarding factor is the change of mindset from approaches based on the old industrial paradigm to the new knowledge oriented paradigm. From "one size fits all" to customisation and buyer behaviour oriented segmentation based on structural flexibility. The new approach requires a change of processes and management systems, but most of all, a change of mindset, organisation structure and behaviour.This may create internal resistance that has to be overcome to reach the desired future state. This future state is highly dependent on cooperation and consensus with external companies, and the next step is therefore to extend the alignment approach to the chosen partners in the demand chain. The development towards channel rather than company competition requires an interorganisational approach to channel design. Internal alignment and cooperation is necessary but not sufficient, which means that an agile and dynamically aligned demand chain has to be created.All this is well known and documented in both research and theory. However, the challenge is to implement these theories, models and behaviour in practice. This paper presents one practical approach to implementation of the theories put forth by Ericsson [Ericsson D, 2011, Demand chain management - The evolution, ORiON, 27(1, pp. 45-81.].

  18. THE PRICE OF HIGHER EDUCATION AND INDIVIDUAL DEMAND

    Directory of Open Access Journals (Sweden)

    Filiz Golpek

    2012-01-01

    Full Text Available The rise in the living standards in most of the world, the rise in population and schooling rates have increased the demand for higher education. The attribution of semi public property becomes determinant to decide whom will provide the supply and the production in semi public properties is realized by means of a supply and demand mechanism. The supply of higher education is mostly secured in accordance with the public demand as well as the resources available.  In addition, the fact that higher education services have produced significant benefits has led to over demand. This situation relates to a simple economic rule that a commodity or service which costs almost nothing or little will increase until the mariginal benefit of its demand equals to 0 or almost 0. However, the educational supply and demand is difficult to identify in accordance to the supply and demand and balance of price as observed in the economic theory. The high profits that would be attracted in the future are significant factors influencing individual’s decisions for investment. The decision for investment depends on the possible return in the future, the cost of investment, and the current interest rates. Higher education with investment purposes is influenced by these three factors and higher education is demanded more and more by individuals on the expectation that they will gain high profits In theory, it is accepted that the basic factors identifying the demand for higher education are in harmony with empirical research results in several countries including Turkey.

  19. Fuel oil quality task force

    Energy Technology Data Exchange (ETDEWEB)

    Laisy, J.; Turk, V. [R.W. Beckett Corp., Elyria, OH (United States)

    1997-09-01

    In April, 1996, the R.W. Beckett Corporation became aware of a series of apparently unrelated symptoms that made the leadership of the company concerned that there could be a fuel oil quality problem. A task force of company employees and industry consultants was convened to address the topic of current No. 2 heating oil quality and its effect on burner performance. The task force studied changes in fuel oil specifications and trends in properties that have occurred over the past few years. Experiments were performed at Beckett and Brookhaven National Laboratory to understand the effect of changes in some fuel oil properties. Studies by other groups were reviewed, and field installations were inspected to gain information about the performance of fuel oil that is currently being used in the U.S. and Canada. There was a special concern about the use of red dye in heating oils and the impact of sulfur levels due to the October, 1993 requirement of low sulfur (<0.05%) for on-highway diesel fuel. The results of the task force`s efforts were published in July, 1996. The primary conclusion of the task force was that there is not a crisis or widespread general problem with fuel oil quality. Localized problems that were seen may have been related to refinery practices and/or non-traditional fuel sources. System cleanliness is very important and the cause of many oil burner system problems. Finally, heating oil quality should get ongoing careful attention by Beckett engineering personnel and heating oil industry groups.

  20. Teaching Strategies for Building Student Persistence on Challenging Tasks: Insights Emerging from Two Approaches to Teacher Professional Learning

    Science.gov (United States)

    Clarke, Doug; Cheeseman, Jill; Roche, Anne; van der Schans, Stephanie

    2014-01-01

    In recent years, the mathematics education research community has given increased focus to the use of cognitively demanding, challenging tasks and the demands placed on students and teachers by their use. In particular, there is evidence that a major issue is students' lack of persistence when working on such tasks. In this article, we report on…

  1. Holistic face perception in young and older adults: effects of feedback and attentional demand.

    Science.gov (United States)

    Meinhardt-Injac, Bozana; Persike, Malte; Meinhardt, Günter

    2014-01-01

    Evidence exists for age-related decline in face cognition ability. However, the extents to which attentional demand and flexibility to adapt viewing strategies contribute to age-related decline in face cognition tests is poorly understood. Here, we studied holistic face perception in older (age range 65-78 years, mean age 69.9) and young adults (age range 20-32 years, mean age 23.1) using the complete design for a sequential study-test composite face task (Richler et al., 2008b). Attentional demand was varied using trials that required participants to attend to both face halves and to redirect attention to one face half during the test (high attentional demand), and trials that allowed participants to keep a pre-adjusted focus (low attentional demand). We also varied viewing time and provided trial-by-trial feedback or no feedback. We observed strong composite effects, which were larger for the elderly in all conditions, independent of viewing time. Composite effects were smaller for low attentional demand, and larger for high attentional demand. No age-related differences were found in this respect. Feedback also reduced the composite effects in both age groups. Young adults could benefit from feedback in conditions with low and high attentional demands. Older adults performed better with feedback only in trials with low attentional demand. When attentional demand was high, older adults could no longer use the feedback signal, and performed worse with feedback than without. These findings suggest that older adults tend to use a global focus for faces, albeit piecemeal analysis is required for the task, and have difficulties adapting their viewing strategies when task demands are high. These results are consistent with the idea that elderly rely more on holistic strategies as a means to reduce perceptual and cognitive load when processing resources are limited (Konar et al., 2013).

  2. Research of Dependent Tasks Scheduling Algorithm in Cloud Computing Environments

    Directory of Open Access Journals (Sweden)

    Chen Qing-Yi

    2016-01-01

    Full Text Available With the dependent relationship of tasks submitted by the users in the model of Cloud computing resources scheduling become stronger and stronger, it is worthy of studying how to optimize the scheduling strategy and algorithm to meet the different demands of the users, and it is absolutely importance. In this article, the author analysed the factors that will affect the entire task-sets execution firstly. Then proposed a new tasks scheduling model based on the original priority calculation method and the idea of redundant duplication of tasks. In the phase of tasks scheduling in the model, the execution results of all parent tasks of the subtask that being executing are considered. The costs of communication between task-sets has reduced by the method of redundant duplication of tasks, so that the execution time of some subtasks share be advanced, and the entire execution efficiency of task-sets can be increased. At the end of this article, from the comparative results of the space-time complexity of contrast algorithms and the algorithm proposed by the author during the process of processing dependent tasks, we can find that subtasks execution time can be advanced and the complete time of the whole task-set can be cut down to a certain extent

  3. Task-baseret kommunikativ sprogundervisning

    DEFF Research Database (Denmark)

    Pedersen, Michael Svendsen

    2015-01-01

    Definition af task-baseret sprogundervisning, kriterier for task. Forskning i Second Language Acquisition med brug af task, tilrettelæggelse af task-baseret kommunikativ undervisning. Begrænsninger i og perspektiver for videreudvikling af task-baseret sprogundervising-......Definition af task-baseret sprogundervisning, kriterier for task. Forskning i Second Language Acquisition med brug af task, tilrettelæggelse af task-baseret kommunikativ undervisning. Begrænsninger i og perspektiver for videreudvikling af task-baseret sprogundervising-...

  4. Development of a valid simulation assessment for a military dismounted assault task.

    Science.gov (United States)

    Silk, Aaron J; Billing, Daniel C

    2013-03-01

    The Australian Defence Force is currently developing physical standards commensurate with job demands. Vital to this development process has been the accurate profiling of common military tasks. One such task required of all dismounted combat soldiers, an offensive assault on an enemy force, was the subject of in-depth profiling. In addition to overall assault performance, potential differences among patrol roles (scout, gunner, and flank) were investigated. Three different mock assaults of 100 to 150 m were performed by three patrols comprising qualified experienced infantry soldiers. Each soldier was fitted with a heart rate monitor and wore a global positioning device. Average assault duration was 6.5 minutes and required nineteen 7-m bounds performed on a 22-seconds duty cycle at 75% heart rate reserve and a work to rest ratio 1:4. Assaults conducted in more densely vegetated terrain resulted in significantly reduced (p 0.05). As a result of profiling the assault task, a valid simulation capable of assessing soldiers' physical capacity to perform this task was developed.

  5. eHealth literacy demands and cognitive processes underlying barriers in consumer health information seeking

    Directory of Open Access Journals (Sweden)

    Connie V. Chan

    2015-12-01

    Full Text Available Background: Consumer eHealth tools play an increasingly important role in engaging patients as participants in managing their health and seeking health information. However, there is a documented gap between the skill and knowledge demands of eHealth systems and user competencies to benefit from these tools. Objective: This research aims to reveal the knowledge- and skill-related barriers to effective use of eHealth tools. Methods: We used a micro-analytic framework for characterizing the different cognitive dimensions of eHealth literacy to classify task demands and barriers that 20 participants experienced while performing online information-seeking and decision-making tasks. Results: Participants ranged widely in their task performance across all 6 tasks as measured by task scores and types of barriers encountered. The highest performing participant experienced only 14 barriers whereas the lowest scoring one experienced 153. A more detailed analysis of two tasks revealed that the highest number of incorrect answers and experienced barriers were caused by tasks requiring: (a Media literacy and Science literacy at high cognitive complexity levels and (b a combination of Numeracy and Information literacy at different cognitive complexity levels. Conclusions: Applying this type of analysis enabled us to characterize task demands by literacy type and by cognitive complexity. Mapping barriers to literacy types provided insight into the interaction between users and eHealth tasks. Although the gap between eHealth tools, users’ skills, and knowledge can be difficult to bridge, an understanding of the cognitive complexity and literacy demands can serve to reduce the gap between designer and consumer.

  6. Industrial demand side management status report - synopsis

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, M.E.F.; Conger, R.L.; Foley, T.J. [and others

    1996-05-01

    Industrial demand side management (DSM) programs, though not as developed or widely implemented as residential and commercial programs, hold the promise of significant energy savings-savings that will benefit industrial firms, utilities and the environment. This paper is a synopsis of a larger research report, Industrial Demand Side Management: A Status Report, prepared for the U.S. Department of Energy. The report provides an overview of and rationale for DSM programs. Benefits and barriers are described, and data from the Manufacturing Energy Consumption Survey are used to estimate potential electricity savings from industrial energy efficiency measures. Overcoming difficulties to effective program implementation is worthwhile, since rough estimates indicate a substantial potential for electricity savings. The report categorizes types of DSM programs, presents several examples of each type, and explores elements of successful programs. Two in-depth case studies (of Boise Cascade and of Eli Lilly and Company) illustrate two types of effective DSM programs. Interviews with staff from state public utility commissions indicate the current thinking about the status and future of industrial DSM programs. Finally, the research report also includes a comprehensive bibliography, a description of technical assistance programs, and an example of a methodology for evaluating potential or actual savings from projects.

  7. Industrial demand side management status report: Synopsis

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, M.E.F.; Conger, R.L.; Foley, T.J.; Parker, J.W.; Placet, M.; Sandahl, L.J.; Spanner, G.E.; Woodruff, M.G.; Norland, D.

    1995-08-01

    Industrial demand side management (DSM) programs, though not as developed or widely implemented as residential and commercial programs, hold the promise of significant energy savings-savings that will benefit industrial firms, utilities and the environment. This paper is a synopsis of a larger research report, Industrial Demand Side Management. A Status Report, prepared for the US Department of Energy. The report provides an overview of and rationale for DSM programs. Benefits and barriers are described, and data from the Manufacturing Energy Consumption Survey are used to estimate potential electricity savings from industrial energy efficiency measures. Overcoming difficulties to effective program implementation is worthwhile, since rough estimates indicate a substantial potential for electricity savings. The report categorizes types of DSM programs, presents several examples of each type, and explores elements of successful programs. Two in-depth case studies (of Boise Cascade and of Eli Lilly and Company) illustrate two types of effective DSM programs. Interviews with staff from state public utility commissions indicate the current thinking about the status and future of industrial DSM programs. Finally, the research report also includes a comprehensive bibliography, a description of technical assistance programs, and an example of a methodology for evaluating potential or actual savings from projects.

  8. Physical demands during folk dancing.

    Science.gov (United States)

    Wigaeus, E; Kilbom, A

    1980-01-01

    This investigation was undertaken to evaluate the aerobic demands during one of the most popular and demanding Swedish folk dances the "hambo". Six men and six women, ranging in age from 22 to 32, participated. Their physical work capacity was investigated on a bicycle ergometer and a treadmill, using two to three submaximal and one maximal loads. All subjects were moderately well-trained and their average maximal oxygen uptake on the treadmill were 2.5 and 3.7 l/min (42.8 and 53.2 ml/kg . min-1) for women and men, respectively. When dancing the "hambo" the heart rate was telemetered, and the Douglas bag technique was used for measurements of pulmonary ventilation and oxygen uptake. The physical demand during "hambo" dancing was high in all subjects. Oxygen uptake was 38.5 and 37.3 ml/kg . min-1 and heart rate 179 and 172 in women and men, respectively. Women used 90% and men 70% of their maximal aerobic power obtained on the treadmill. The pulmonary ventilation and respiratory quotient of the female subjects were lower when dancing as compared to running, possibly because of voluntary restriction of the movements of the thoracic cage. Some popular Scandinavian folk dances are performed at a speed and with an activity pattern resembling the "hambo", while others are performed at a slower pace. The exercise intensity used in "hambo" is more than sufficient to induce training effects in the average individual provided that the dancing is performed at the frequency and for length of time usually recommended for physical training. For older or less fit people dances with a slow pace can be used for training purposes.

  9. High resolution heat atlases for demand and supply mapping

    Directory of Open Access Journals (Sweden)

    Bernd Möller

    2014-02-01

    Full Text Available Significant reductions of heat demand, low-carbon and renewable energy sources, and district heating are key elements in 100% renewable energy systems. Appraisal of district heating along with energy efficient buildings and individual heat supply requires a geographical representation of heat demand, energy efficiency and energy supply. The present paper describes a Heat Atlas built around a spatial database using geographical information systems (GIS. The present atlas allows for per-building calculations of potentials and costs of energy savings, connectivity to existing district heat, and current heat supply and demand. For the entire building mass a conclusive link is established between the built environment and its heat supply. The expansion of district heating; the interconnection of distributed district heating systems; or the question whether to invest in ultra-efficient buildings with individual supply, or in collective heating using renewable energy for heating the current building stock, can be based on improved data.

  10. Synthesizing Econometric Evidence: The Case of Demand Elasticity Estimates.

    Science.gov (United States)

    DeCicca, Philip; Kenkel, Don

    2015-06-01

    Econometric estimates of the responsiveness of health-related consumer demand to higher prices are often key ingredients for risk policy analysis. We review the potential advantages and challenges of synthesizing econometric evidence on the price-responsiveness of consumer demand. We draw on examples of research on consumer demand for health-related goods, especially cigarettes. We argue that the overarching goal of research synthesis in this context is to provide policy-relevant evidence for broad-brush conclusions. We propose three main criteria to select among research synthesis methods. We discuss how in principle and in current practice synthesis of research on the price-elasticity of smoking meets our proposed criteria. Our analysis of current practice also contributes to academic research on the specific policy question of the effectiveness of higher cigarette prices to reduce smoking. Although we point out challenges and limitations, we believe more work on research synthesis in this area will be productive and important.

  11. Different neuroplasticity for task targets and distractors.

    Directory of Open Access Journals (Sweden)

    Elsie Y Spingath

    Full Text Available Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from

  12. Different neuroplasticity for task targets and distractors.

    Science.gov (United States)

    Spingath, Elsie Y; Kang, Hyun Sug; Plummer, Thane; Blake, David T

    2011-01-31

    Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from nonselective

  13. The feasibility of using pupillometry to measure cognitive effort in aphasia: Evidence from a working memory span task

    Directory of Open Access Journals (Sweden)

    Esther Sung Kim

    2015-05-01

    In this study, three PWA completed a computerized picture span task while an eye-tracker measured pupil dilation. As short-term memory demands (i.e., span size increased, average pupil size significantly increased in all three PWA. These data provide preliminary support for the use of pupillometry to gauge cognitive effort in PWA. A larger study of PWA and demographically-matched control participants is currently underway, allowing for analysis of change in pupil size within and between groups. Examination of cognitive effort will provide a more comprehensive understanding of the nature of linguistic and cognitive functioning in aphasia.

  14. Emotional labor demands and compensating wage differentials.

    Science.gov (United States)

    Glomb, Theresa M; Kammeyer-Mueller, John D; Rotundo, Maria

    2004-08-01

    The concept of emotional labor demands and their effects on workers has received considerable attention in recent years, with most studies concentrating on stress, burnout, satisfaction, or other affective outcomes. This study extends the literature by examining the relationship between emotional labor demands and wages at the occupational level. Theories describing the expected effects of job demands and working conditions on wages are described. Results suggest that higher levels of emotional labor demands are associated with lower wage rates for jobs low in cognitive demands and with higher wage rates for jobs high in cognitive demands. Implications of these findings are discussed. (c) 2004 APA

  15. Connecting empowerment-focused HRM and labour productivity to work engagement: the mediating role of job demands and resources

    NARCIS (Netherlands)

    van de Voorde, Karina; Veld, M.F.A.; van Veldhoven, Marc

    2016-01-01

    Integrating the strategic HRM literature with key aspects of the job demands-resources (JDR) model, we propose in this study that empowerment-focused HRM and labour productivity influence work engagement of employees by shaping task-related resources and demands. A total of 311 employees nested with

  16. Industrial demand side management: A status report

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, M.F.; Conger, R.L.; Foley, T.J. [and others

    1995-05-01

    This report provides an overview of and rationale for industrial demand side management (DSM) programs. Benefits and barriers are described, and data from the Manufacturing Energy Consumption Survey are used to estimate potential energy savings in kilowatt hours. The report presents types and examples of programs and explores elements of successful programs. Two in-depth case studies (from Boise Cascade and Eli Lilly and Company) illustrate two types of effective DSM programs. Interviews with staff from state public utility commissions indicate the current thinking about the status and future of industrial DSM programs. A comprehensive bibliography is included, technical assistance programs are listed and described, and a methodology for evaluating potential or actual savings from projects is delineated.

  17. Resiliently evolving supply-demand networks

    CERN Document Server

    Rubido, Nicolás; Baptista, Murilo S

    2013-01-01

    The ability to design a transport network such that commodities are brought from suppliers to consumers in a steady, optimal, and stable way is of great importance for nowadays distribution systems. In this Letter, by using the circuit laws of Kirchhoff and Ohm, we provide the exact capacities of the edges that an optimal supply-demand network should have to operate stably under perturbations. The perturbations we consider are the evolution of the connecting topology, the decentralisation of hub sources or sinks, and the intermittence of suppliers/consumers characteristics. We analyse these conditions and the impact of our results, both on the current UK power-grid structure and on numerically generated evolving archetypal network topologies.

  18. Resiliently evolving supply-demand networks.

    Science.gov (United States)

    Rubido, Nicolás; Grebogi, Celso; Baptista, Murilo S

    2014-01-01

    The ability to design a transport network such that commodities are brought from suppliers to consumers in a steady, optimal, and stable way is of great importance for distribution systems nowadays. In this work, by using the circuit laws of Kirchhoff and Ohm, we provide the exact capacities of the edges that an optimal supply-demand network should have to operate stably under perturbations, i.e., without overloading. The perturbations we consider are the evolution of the connecting topology, the decentralization of hub sources or sinks, and the intermittence of supplier and consumer characteristics. We analyze these conditions and the impact of our results, both on the current United Kingdom power-grid structure and on numerically generated evolving archetypal network topologies.

  19. Living with the extreme demand

    Directory of Open Access Journals (Sweden)

    Teppo Eskelinen

    2013-05-01

    Full Text Available Most of the ethical literature on extreme poverty suggests, that some, if not most, of the incomes of the residents of rich countries ought to be donated to the global poor. Yet complying with this ethical demand becomes increasingly more difficult as the changes in lifestyle in the (postindustrial north demand ever more consumption in order to obtain the necessities for survival in such societies. In this article, I will discuss Peter Singer's famous arguments for the ethical duty to donate one's possessions, and elaborate the conception of needs prevalent in both Singer's theory and the theories of many of his critics. My argument is that we have to recognise a category of needs called 'social necessities' that are neither luxuries nor basic needs. This leads to two main conclusions: first, the space for ethical deliberation on whether to donate to life-saving purposes is socially conditioned; and second, ethical strategies of redistribution ought to be accompanied with institutional changes, which also concern the conditions in wealthy countries.http://dx.doi.org/10.5324/eip.v7i1.1791

  20. Demand Side Bidding. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Spahn, Andrew

    2003-12-31

    This document sets forth the final report for a financial assistance award for the National Association of Regulatory Utility Commissioners (NARUC) to enhance coordination between the building operators and power system operators in terms of demand-side responses to Location Based Marginal Pricing (LBMP). Potential benefits of this project include improved power system reliability, enhanced environmental quality, mitigation of high locational prices within congested areas, and the reduction of market barriers for demand-side market participants. NARUC, led by its Committee on Energy Resources and the Environment (ERE), actively works to promote the development and use of energy efficiency and clean distributive energy policies within the framework of a dynamic regulatory environment. Electric industry restructuring, energy shortages in California, and energy market transformation intensifies the need for reliable information and strategies regarding electric reliability policy and practice. NARUC promotes clean distributive generation and increased energy efficiency in the context of the energy sector restructuring process. NARUC, through ERE's Subcommittee on Energy Efficiency, strives to improve energy efficiency by creating working markets. Market transformation seeks opportunities where small amounts of investment can create sustainable markets for more efficient products, services, and design practices.