Do Work Placements Improve Final Year Academic Performance or Do High-Calibre Students Choose to Do Work Placements?

ERIC Educational Resources Information Center

Jones, C. M.; Green, J. P.; Higson, H. E.

2017-01-01

This study investigates whether the completion of an optional sandwich work placement enhances student performance in final year examinations. Using Propensity Score Matching, our analysis departs from the literature by controlling for self-selection. Previous studies may have overestimated the impact of sandwich work placements on performance…

Neck Pain, Preoperative Opioids, and Functionality After Cervical Fusion.

PubMed

Faour, Mhamad; Anderson, Joshua T; Haas, Arnold R; Percy, Rick; Woods, Stephen T; Ahn, Uri M; Ahn, Nicholas U

2017-01-01

The use of opioids among patients with workers' compensation claims is associated with tremendous costs, especially for patients who undergo spinal surgery. This study compared return-to-work rates after single-level cervical fusion for degenerative disk disease between patients who received opioids before surgery and patients who underwent fusion with no previous opioid use. All study subjects qualified for workers' compensation benefits for injuries sustained at work between 1993 and 2011. The study population included 281 subjects who underwent single-level cervical fusion for degenerative disk disease with International Classification of Diseases, Ninth Revision, and Current Procedural Terminology code algorithms. The opioid group included 77 subjects who received opioids preoperatively. The control group included 204 subjects who had surgery with no previous opioid use. The primary outcome was meeting return-to-work criteria within 3 years of follow-up after fusion. Secondary outcome measures after surgery, surgical details, and presurgical characteristics for each cohort also were collected. In 36.4% of the opioid group, return-to-work criteria were met compared with 56.4% of the control group. Patients who took opioids were less likely to meet return-to-work criteria compared with the control group (odds ratio, 0.44; 95% confidence interval, 0.26-0.76; P=.0028). Return-to-work rates within the first year after fusion were 24.7% for the opioid group and 45.6% for the control group (P=.0014). Patients who used opioids were absent from work for 255 more days compared with the control group (P=.0001). The use of opioids for management of diskogenic neck pain, with the possibility of surgical intervention, is a negative predictor of successful return to work after fusion in a workers' compensation population. [Orthopedics. 2017; 40(1):25-32.]. Copyright 2016, SLACK Incorporated.

Design of a Microprogram Control Unit with Concurrent Error Detection.

DTIC Science & Technology

1984-08-01

I fxoot Office of Naval Research N/A N00039-80-C-0556 ta. ADDRESS (City. St.. and ZIP Cod 10. SOURCE OF FUNOING N0. -PROGRAM PROJECT TASK WORK UNIT...However, the CED concept is mainly applied to various codes data transmission, and simple functional units, such as arithmetic units. Little work has...been done in the control unit area. Previous work is primarily in the use of clanical self-checking circuits, using bit slicin& parity, and m-out-of-n

Executive Control in a Modified Antisaccade Task: Effects of Aging and Bilingualism

ERIC Educational Resources Information Center

Bialystok, Ellen; Craik, Fergus I. M.; Ryan, Jennifer

2006-01-01

Two studies are reported that assess differences associated with aging and bilingualism in an executive control task. Previous work has suggested that bilinguals have an advantage over monolinguals in nonlinguistic tasks involving executive control; the major purpose of the present article is to ascertain which aspects of control are sensitive…

Results of telerobotic hand controller study using force information and rate control

NASA Technical Reports Server (NTRS)

Willshire, Kelli F.; Harrison, F. W.; Hogge, Edward F.; Williams, Robert L.; Soloway, Donald

1992-01-01

To increase quantified information about the effectiveness and subjective workload of force information relayed through manipulator input control devices, a space related task was performed by eight subjects with kinesthetic force feedback and/or local force accommodation through three different input control devices (i.e., hand controllers) operating in rate control mode. Task completion time, manipulator work, and subjective responses were measured. Results indicated a difference among the hand controllers. For the Honeywell six degree-of-freedom hand controller, the overall task completion times were shortest, the amount of work exerted was the least, and was the most preferred by test subjects. Neither force accommodation with or without reflection resulted in shorter task completion times or reduced work although those conditions were better than no force information for some aspects. Comparisons of results from previous studies are discussed.

Visual working memory capacity increases between ages 3 and 8 years, controlling for gains in attention, perception, and executive control.

PubMed

Pailian, Hrag; Libertus, Melissa E; Feigenson, Lisa; Halberda, Justin

2016-08-01

Research in adults has aimed to characterize constraints on the capacity of Visual Working Memory (VWM), in part because of the system's broader impacts throughout cognition. However, less is known about how VWM develops in childhood. Existing work has reached conflicting conclusions as to whether VWM storage capacity increases after infancy, and if so, when and by how much. One challenge is that previous studies did not control for developmental changes in attention and executive processing, which also may undergo improvement. We investigated the development of VWM storage capacity in children from 3 to 8 years of age, and in adults, while controlling for developmental change in exogenous and endogenous attention and executive control. Our results reveal that, when controlling for improvements in these abilities, VWM storage capacity increases across development and approaches adult-like levels between ages 6 and 8 years. More generally, this work highlights the value of estimating working memory, attention, perception, and decision-making components together.

Work Engagement Accumulation of Task, Social, Personal Resources: A Three-Wave Structural Equation Model

ERIC Educational Resources Information Center

Weigl, Matthias; Hornung, Severin; Parker, Sharon K.; Petru, Raluca; Glaser, Jurgen; Angerer, Peter

2010-01-01

Drawing on Conservation of Resources Theory and previous research on work engagement, the present study investigates gain spirals between employees' engagement and their task, social, and personal resources. It focuses on the key resources of job control, positive work relationships, and active coping behavior. In a three-wave design, work…

Context-specific attentional sampling: Intentional control as a pre-requisite for contextual control.

PubMed

Brosowsky, Nicholaus P; Crump, Matthew J C

2016-08-01

Recent work suggests that environmental cues associated with previous attentional control settings can rapidly and involuntarily adjust attentional priorities. The current study tests predictions from adaptive-learning and memory-based theories of contextual control about the role of intentions for setting attentional priorities. To extend the empirical boundaries of contextual control phenomena, and to determine whether theoretical principles of contextual control are generalizable we used a novel bi-dimensional stimulus sampling task. Subjects viewed briefly presented arrays of letters and colors presented above or below fixation, and identified specific stimuli according to a dimensional (letter or color) and positional cue. Location was predictive of the cued dimension, but not the position or identity. In contrast to previous findings, contextual control failed to develop through automatic, adaptive-learning processes. Instead, previous experience with intentionally changing attentional sampling priorities between different contexts was required for contextual control to develop. Copyright © 2016 Elsevier Inc. All rights reserved.

The psychosocial work environment is associated with risk of stroke at working age.

PubMed

Jood, Katarina; Karlsson, Nadine; Medin, Jennie; Pessah-Rasmussen, Hélène; Wester, Per; Ekberg, Kerstin

2017-07-01

Objective The aim of this study was to explore the relation between the risk of first-ever stroke at working age and psychological work environmental factors. Methods A consecutive multicenter matched 1:2 case-control study of acute stroke cases (N=198, age 30-65 years) who had been working full-time at the time of their stroke and 396 sex- and age-matched controls. Stroke cases and controls answered questionnaires on their psychosocial situation during the previous 12 months. The psychosocial work environment was assessed using three different measures: the job-control-demand model, the effort-reward imbalance (ERI) score, and exposures to conflict at work. Results Among 198 stroke cases and 396 controls, job strain [odds ratio (OR) 1.30, 95% confidence interval (95% CI) 1.05-1.62], ERI (OR 1.28, 95% CI 1.01-1.62), and conflict at work (OR 1.75, 95% CI 1.07-2.88) were independent risk factors of stroke in multivariable regression models. Conclusions Adverse psychosocial working conditions during the past 12 months were more frequently observed among stroke cases. Since these factors are presumably modifiable, interventional studies targeting job strain and emotional work environment are warranted.

Professions and Working Conditions Associated With Community-Acquired Pneumonia.

PubMed

Almirall, Jordi; Serra-Prat, Mateu; Bolíbar, Ignasi; Palomera, Elisabet; Roig, Jordi; Boixeda, Ramon; Bartolomé, Maria; de la Torre, Mari; Parra, Olga; Torres, Antoni

2015-12-01

Community-acquired pneumonia (CAP) is not considered a professional disease, and the effect of different occupations and working conditions on susceptibility to CAP is unknown. The aim of this study is to determine whether different jobs and certain working conditions are risk factors for CAP. Over a 1-year period, all radiologically confirmed cases of CAP (n=1,336) and age- and sex-matched controls (n=1,326) were enrolled in a population-based case-control study. A questionnaire on CAP risk factors, including work-related questions, was administered to all participants during an in-person interview. The bivariate analysis showed that office work is a protective factor against CAP, while building work, contact with dust and sudden changes of temperature in the workplace were risk factors for CAP. The occupational factor disappeared when the multivariate analysis was adjusted for working conditions. Contact with dust (previous month) and sudden changes of temperature (previous 3 months) were risk factors for CAP, irrespective of the number of years spent working in these conditions, suggesting reversibility. Some recent working conditions such as exposure to dust and sudden changes of temperature in the workplace are risk factors for CAP. Both factors are reversible and preventable. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

Best management practices used by KYTC for on-site erosion control.

DOT National Transportation Integrated Search

2006-11-01

New erosion control procedures (ECP) have recently been implemented by the Kentucky Transportation Cabinet (KYTC). Previously, consultants and designers developed the ECP as a part of the design plans. In many cases these did not work in the field. T...

SILICATES FOR CORROSION CONTROL IN BUILDING POTABLE WATER SYSTEMS

EPA Science Inventory

Silicates have been used to control the corrosion of drinking water distribution system materials. Previous work has shown that they are particularly useful in reducing the release of zinc from galvanized materials in hot water systems. Negatively charged silicate species were re...

Automatic speech recognition in air traffic control

NASA Technical Reports Server (NTRS)

Karlsson, Joakim

1990-01-01

Automatic Speech Recognition (ASR) technology and its application to the Air Traffic Control system are described. The advantages of applying ASR to Air Traffic Control, as well as criteria for choosing a suitable ASR system are presented. Results from previous research and directions for future work at the Flight Transportation Laboratory are outlined.

General Aviation Interior Noise. Part 3; Noise Control Measure Evaluation

NASA Technical Reports Server (NTRS)

Unruh, James F.; Till, Paul D.; Palumbo, Daniel L. (Technical Monitor)

2002-01-01

The work reported herein is an extension to the work accomplished under NASA Grant NAG1-2091 on the development of noise/source/path identification techniques for single engine propeller driven General Aviation aircraft. The previous work developed a Conditioned Response Analysis (CRA) technique to identify potential noise sources that contributed to the dominating tonal responses within the aircraft cabin. The objective of the present effort was to improve and verify the findings of the CRA and develop and demonstrate noise control measures for single engine propeller driven General Aviation aircraft.

Improved Temperature Dynamic Model of Turbine Subcomponents for Facilitation of Generalized Tip Clearance Control

NASA Technical Reports Server (NTRS)

Kypuros, Javier A.; Colson, Rodrigo; Munoz, Afredo

2004-01-01

This paper describes efforts conducted to improve dynamic temperature estimations of a turbine tip clearance system to facilitate design of a generalized tip clearance controller. This work builds upon research previously conducted and presented in and focuses primarily on improving dynamic temperature estimations of the primary components affecting tip clearance (i.e. the rotor, blades, and casing/shroud). The temperature profiles estimated by the previous model iteration, specifically for the rotor and blades, were found to be inaccurate and, more importantly, insufficient to facilitate controller design. Some assumptions made to facilitate the previous results were not valid, and thus improvements are presented here to better match the physical reality. As will be shown, the improved temperature sub- models, match a commercially validated model and are sufficiently simplified to aid in controller design.

Efficiency of the Prefrontal Cortex during Working Memory in Attention-Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Sheridan, Margaret A.; Hinshaw, Stephen; D'Esposito, Mark

2007-01-01

Objective: Previous research has demonstrated that during task conditions requiring an increase in inhibitory function or working memory, children and adults with attention-deficit/hyperactivity disorder (ADHD) exhibit greater and more varied prefrontal cortical(PFC) activation compared to age-matched control participants. This pattern may reflect…

Decentralised control of continuous Petri nets

NASA Astrophysics Data System (ADS)

Wang, Liewei; Wang, Xu

2017-05-01

This paper focuses on decentralised control of systems modelled by continuous Petri nets, in which a target marking control problem is discussed. In some previous works, an efficient ON/OFF strategy-based minimum-time controller was developed. Nevertheless, the convergence is only proved for subclasses like Choice-Free nets. For a general net, the pre-conditions of applying the ON/OFF strategy are not given; therefore, the application scope of the method is unclear. In this work, we provide two sufficient conditions of applying the ON/OFF strategy-based controller to general nets. Furthermore, an extended algorithm for general nets is proposed, in which control laws are computed based on some limited information, without knowing the detailed structure of subsystems.

Symmetries in vakonomic dynamics: applications to optimal control

NASA Astrophysics Data System (ADS)

Martínez, Sonia; Cortés, Jorge; de León, Manuel

2001-06-01

Symmetries in vakonomic dynamics are discussed. Appropriate notions are introduced and their relationship with previous work on symmetries of singular Lagrangian systems is shown. Some Noether-type theorems are obtained. The results are applied to a class of general optimal control problems and to kinematic locomotion systems.

What works best for whom? An exploratory, subgroup analysis in a randomized, controlled trial on the effectiveness of a workplace intervention in low back pain patients on return to work.

PubMed

Steenstra, Ivan A; Knol, Dirk L; Bongers, Paulien M; Anema, Johannes R; van Mechelen, Willem; de Vet, Henrica C W

2009-05-20

Exploratory subgroup analysis in a randomized controlled trial (RCT). To detect possible moderators in the effectiveness of a workplace intervention in a population of workers with sick leave due to sub acute nonspecific low back pain. In a recently published RCT, a workplace intervention was effective on return to work, compared to usual care. Examining the heterogeneity of effect sizes within the population in this RCT (n = 196) can lead to information on the effectiveness of the intervention in subgroups of patients. A subgroup analysis was performed by adding interaction terms to the statistical model. Before analysis the following possible moderators for treatment were identified: age, gender, pain, functional status, heavy work, and sick leave in the previous 12 months. Cox regression analyses were performed and survival curves were plotted. The interaction (P = 0.02) between age (dichotomized at the median value) and the workplace intervention indicates a modifying effect. The workplace intervention is more effective for workers > or =44 years (HR, 95% CI = 2.5, [1.6, 4.1] vs. 1.2 [0.8, 1.8] for workers <44 years old). The interaction between sick leave in the previous 12 months and the workplace intervention is significant (P = 0.02). The intervention is more effective for workers with previous sick leave (HR, 95% CI = 2.8 [1.7, 4.9] vs. 1.3 [0.8, 2.0]). A modifying effect of gender, heavy work, and pain score and functional status on the effectiveness of this intervention was not found. The findings from these exploratory analyses should be tested in future RCTs. This workplace intervention seems very suitable for return to work of older workers and workers with previous sick leave. Gender, perceived heavy work, and baseline scores in pain and functional status should not be a basis for assignment to this intervention.

Positive and Negative Reinforcement Effects on Behavior in a Three-Person Microsociety.

DTIC Science & Technology

1983-12-01

Per-hour earning potential uas roughly equivalent among the groups. Prdr The consequences of ompletlng a work trip were varied to assess the effects ...31 abandoned his previously established pattern. These effects are attributable, at least In part, to the style of alternating work that the... working under aversive control. These effects suggest that the functional properties of work (C-.h. oonsequences) were far more significant to the group

A swallowtail catastrophe model for the emergence of leadership in coordination-intensive groups.

PubMed

Guastello, Stephen J; Bond, Robert W

2007-04-01

This research extended the previous studies concerning the swallowtail catastrophe model for leadership emergence to coordination-intensive groups. Thirteen 4-person groups composed of undergraduates played in Intersection coordination (card game) task and were allowed to talk while performing it; 13 other groups worked nonverbally. A questionnaire measured leadership emergence at the end of the game along with other social contributions to the groups' efforts. The swallowtail catastrophe model that was evident in previous leadership emergence phenomena in creative problem solving and production groups was found here also. All three control parameters were identified: a general participation variable that was akin to K in the rugged landscape model of self-organization, task control, and whether the groups worked verbally or nonverbally. Several new avenues for future research were delineated.

Mississippi Delta native strain of Beauveria bassiana for control of TPB

USDA-ARS?s Scientific Manuscript database

Previous works reported that Beauveria bassiana (Balsamo) isolates from tarnished plant bug, TPB, Lygus lineolaris Palisot de Beauvois, (Hemiptera: Miridae) have shown a great potential to be used as a microbial control for TPB, particularly the NI8 strain, isolated from the TPB from Mississippi De...

Working with Schools in Identifying and Overcoming Emotional Barriers to Learning

ERIC Educational Resources Information Center

Nash, Poppy; Schlösser, Annette

2015-01-01

This paper reports a case study on working closely with a secondary school, to enhance understanding of disruptive behaviour, through the use of bespoke Continuing Professional Development (CPD) materials. This project evolved from the researchers' previous research on the extent to which teachers believe disruptive pupils can control their…

Real-time, ultrasound-based control of a virtual hand by a trans-radial amputee.

PubMed

Baker, Clayton A; Akhlaghi, Nima; Rangwala, Huzefa; Kosecka, Jana; Sikdar, Siddhartha

2016-08-01

Advancements in multiarticulate upper-limb prosthetics have outpaced the development of intuitive, non-invasive control mechanisms for implementing them. Surface electromyography is currently the most popular non-invasive control method, but presents a number of drawbacks including poor deep-muscle specificity. Previous research established the viability of ultrasound imaging as an alternative means of decoding movement intent, and demonstrated the ability to distinguish between complex grasps in able-bodied subjects via imaging of the anterior forearm musculature. In order to translate this work to clinical viability, able-bodied testing is insufficient. Amputation-induced changes in muscular geometry, dynamics, and imaging characteristics are all likely to influence the effectiveness of our existing techniques. In this work, we conducted preliminary trials with a transradial amputee participant to assess these effects, and potentially elucidate necessary refinements to our approach. Two trials were performed, the first using a set of three motion types, and the second using four. After a brief training period in each trial, the participant was able to control a virtual prosthetic hand in real-time; attempted grasps were successfully classified with a rate of 77% in trial 1, and 71% in trial 2. While the results are sub-optimal compared to our previous able-bodied testing, they are a promising step forward. More importantly, the data collected during these trials can provide valuable information for refining our image processing methods, especially via comparison to previously acquired data from able-bodied individuals. Ultimately, further work with amputees is a necessity for translation towards clinical application.

Temporal Dynamic Controllability Revisited

NASA Technical Reports Server (NTRS)

Morris, Paul H.; Muscettola, Nicola

2005-01-01

An important issue for temporal planners is the ability to handle temporal uncertainty. We revisit the question of how to determine whether a given set of temporal requirements are feasible in the light of uncertain durations of some processes. In particular, we consider how best to determine whether a network is Dynamically Controllable, i.e., whether a dynamic strategy exists for executing the network that is guaranteed to satisfy the requirements. Previous work has shown the existence of a pseudo-polynomial algorithm for testing Dynamic Controllability. Here, we greatly simplify the previous framework, and present a true polynomial algorithm with a cutoff based only on the number of nodes.

Working Memory and Cognitive Flexibility Mediates Visuoconstructional Abilities in Older Adults with Heterogeneous Cognitive Ability.

PubMed

Ávila, Rafaela T; de Paula, Jonas J; Bicalho, Maria A; Moraes, Edgar N; Nicolato, Rodrigo; Malloy-Diniz, Leandro F; Diniz, Breno S

2015-05-01

Previous studies suggest that executive functions influence the performance on visuoconstructional tasks. This study aims to investigate whether the relationship between planning ability and the copy of complex figures is mediated by distinct components of executive functions (i.e., working memory, inhibitory control and cognitive flexibility). We included a 129 older adults with Alzheimer's disease (n=36, AD), mild cognitive impairment (MCI, n=67), and with no evidence of cognitive impairment (controls, n=26). We evaluated the mediation effect of planning abilities, working memory, cognitive flexibility and inhibitory control on visuoconstructional tasks using a multiple mediation models. We found a significant direct effect of planning on visuoconstructional abilities and a partial mediation effect of working memory and cognitive flexibility on visuoconstructional abilities. The present results indicate that the performance on visuoconstructional task is mediated by multiple interrelated executive functions components, in particular working memory and cognitive flexibility.

Outer synchronization of complex networks with internal delay and coupling delay via aperiodically intermittent pinning control

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Wang, Xingyuan; Wang, Chunpeng; Xia, Zhiqiu

This paper concerns the outer synchronization problem between two complex delayed networks via the method of aperiodically intermittent pinning control. Apart from previous works, internal delay and coupling delay are both involved in this model, and the designed intermittent controllers can be aperiodic. The main work in this paper can be summarized as follows: First, two cases of aperiodically intermittent control with constant gain and adaptive gain are implemented, respectively. The intermittent control and pinning control are combined to reduce consumptions further. Then, based on the Lyapunov stability theory, synchronization protocols are given by strict derivation. Especially, the designed controllers are indeed simple and valid in application of theory to practice. Finally, numerical examples put the proposed control methods to the test.

Effects of theatrical smokes and fogs on respiratory health in the entertainment industry.

PubMed

Varughese, Sunil; Teschke, Kay; Brauer, Michael; Chow, Yat; van Netten, Chris; Kennedy, Susan M

2005-05-01

Theatrical fogs (glycol or mineral oil aerosols) are widely used in the entertainment industry to create special effects and make lighting visible. We studied 101 employees at 19 sites using fogs and measured personal fog exposures, across work shift lung function, and acute and chronic symptoms. Results were also compared to an external control population, studied previously. Chronic work-related wheezing and chest tightness were significantly associated with increased cumulative exposure to fogs (mineral oil and glycols) over the previous 2 years. Acute cough and dry throat were associated with acute exposure to glycol-based fogs; increased acute upper airway symptoms were associated with increased fog aerosol overall. Lung function was significantly lower among those working closest to the fog source. Mineral oil- and glycol-based fogs are associated with acute and chronic adverse effects on respiratory health among employees. Reducing exposure, through controls, substitution, and elimination where possible, is likely to reduce these effects. (c) 2005 Wiley-Liss, Inc.

Shift work, job strain and changes in the body mass index among women: a prospective study.

PubMed

Fujishiro, Kaori; Lividoti Hibert, Eileen; Schernhammer, Eva; Rich-Edwards, Janet W

2017-06-01

The effects of job strain and shift work on weight gain have not been studied jointly. Cross-sectional and longitudinal studies on shift work and weight gain have reported different results. This study examines potential effect modification by job strain on the link between shift work and weight gain, and concurrent and delayed effects of shift work on weight gain. Data came from 52 622 women who participated in the Nurses' Health Study II, a prospective cohort study. Using linear regression, we modelled change in body mass index (BMI) over 4 years as a function of change in job strain, cumulative exposure to rotating night shift previously and during the 4 years (ie, previous and concurrent exposures) and the interaction between job strain and concurrent shift work exposure. Age, race/ethnicity, pregnancy history, baseline BMI, job types and health behaviours at baseline were controlled for. Job strain and rotating shift work, concurrent and previous, all had independent associations with BMI change during the 4-year period. There was no evidence for effect modification by job strain. Concurrent and previous exposures to rotating night shift had different associations with BMI change: an inverted U-shape for concurrent exposure (ranging from 0.01 to 0.14 kg/m 2 increase), a dose-response for previous exposure (-0.02 to 0.09 kg/m 2 ). Job strain and rotating night shift work have independent contributions to weight gain. Reducing job strain and supporting night shift workers are both important intervention goals. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Field evaluations of emamectin benzoate for control of birch leafminer (Hymenoptera: Tenthredinidae) in Interior Alaska

Treesearch

Christopher J. Fettig; Roger E. Burnside; Christopher J. Hayes; Mark E. Schultz

2012-01-01

Ambermarked birch leafminer, Profenusa thomsoni (Konow) (Hymenoptera: Tenthredinidae), is an exotic, invasive pest of urban and wildland birch, Betula spp., in portions of North America. Extensive defoliation of ornamental birch in Alaska requires that suitable control measures be evaluated and developed. Based on previous work, we evaluated the...

Insights into the Control of Attentional Set in ADHD Using the Attentional Blink Paradigm

ERIC Educational Resources Information Center

Mason, Deanna J.; Humphreys, Glyn W.; Kent, Lindsey

2005-01-01

Background: Previous work on visual selective attention in Attention Deficit Hyperactivity Disorder (ADHD) has utilised spatial search paradigms. This study compared ADHD to control children on a temporal search task using Rapid Serial Visual Presentation (RSVP). In addition, the effects of irrelevant singleton distractors on search performance…

Eye Movement Suppression Interferes with Construction of Object-Centered Spatial Reference Frames in Working Memory

ERIC Educational Resources Information Center

Wallentin, Mikkel; Kristensen, Line Burholt; Olsen, Jacob Hedeager; Nielsen, Andreas Hojlund

2011-01-01

The brain's frontal eye fields (FEF), responsible for eye movement control, are known to be involved in spatial working memory (WM). In a previous fMRI experiment (Wallentin, Roepstorff & Burgess, Neuropsychologia, 2008) it was found that FEF activation was primarily related to the formation of an object-centered, rather than egocentric, spatial…

Working Memory Capacity and the Top-Down Control of Visual Search: Exploring the Boundaries of "Executive Attention"

ERIC Educational Resources Information Center

Kane, Michael J.; Poole, Bradley J.; Tuholski, Stephen W.; Engle, Randall W.

2006-01-01

The executive attention theory of working memory capacity (WMC) proposes that measures of WMC broadly predict higher order cognitive abilities because they tap important and general attention capabilities (R. W. Engle & M. J. Kane, 2004). Previous research demonstrated WMC-related differences in attention tasks that required restraint of habitual…

Separation control with fluidic oscillators in water

NASA Astrophysics Data System (ADS)

Schmidt, H.-J.; Woszidlo, R.; Nayeri, C. N.; Paschereit, C. O.

2017-08-01

The present study assesses the applicability of fluidic oscillators for separation control in water. The first part of this work evaluates the properties of the fluidic oscillators including frequency, cavitation effects, and exerted thrust. Derived from the governing internal dynamics, the oscillation frequency is found to scale directly with the jet's exit velocity and the size of the fluidic oscillator independent of the working fluid. Frequency data from various experiments collapse onto a single curve. The occurrence of cavitation is examined by visual inspection and hydrophone measurements. The oscillation frequency is not affected by cavitation because it does not occur inside the oscillators. The spectral information obtained with the hydrophone provide a reliable indicator for the onset of cavitation at the exit. The performance of the fluidic oscillators for separation control on a bluff body does not seem to be affected by the presence of cavitation. The thrust exerted by an array of fluidic oscillators with water as the working fluid is measured to be even larger than theoretically estimated values. The second part of the presented work compares the performance of fluidic oscillators for separation control in water with previous results in air. The array of fluidic oscillators is installed into the rear end of a bluff body model. The drag improvements based on force balance measurements agree well with previous wind tunnel experiments on the same model. The flow field is examined by pressure measurements and with particle image velocimetry. Similar performance and flow field characteristics are observed in both water and air.

AN ADVANCED TOOL FOR APPLIED INTEGRATED SAFETY MANAGEMENT

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

Potts, T. Todd; Hylko, James M.; Douglas, Terence A.

2003-02-27

WESKEM, LLC's Environmental, Safety and Health (ES&H) Department had previously assessed that a lack of consistency, poor communication and using antiquated communication tools could result in varying operating practices, as well as a failure to capture and disseminate appropriate Integrated Safety Management (ISM) information. To address these issues, the ES&H Department established an Activity Hazard Review (AHR)/Activity Hazard Analysis (AHA) process for systematically identifying, assessing, and controlling hazards associated with project work activities during work planning and execution. Depending on the scope of a project, information from field walkdowns and table-top meetings are collected on an AHR form. The AHAmore » then documents the potential failure and consequence scenarios for a particular hazard. Also, the AHA recommends whether the type of mitigation appears appropriate or whether additional controls should be implemented. Since the application is web based, the information is captured into a single system and organized according to the >200 work activities already recorded in the database. Using the streamlined AHA method improved cycle time from over four hours to an average of one hour, allowing more time to analyze unique hazards and develop appropriate controls. Also, the enhanced configuration control created a readily available AHA library to research and utilize along with standardizing hazard analysis and control selection across four separate work sites located in Kentucky and Tennessee. The AHR/AHA system provides an applied example of how the ISM concept evolved into a standardized field-deployed tool yielding considerable efficiency gains in project planning and resource utilization. Employee safety is preserved through detailed planning that now requires only a portion of the time previously necessary. The available resources can then be applied to implementing appropriate engineering, administrative and personal protective equipment controls in the field.« less

A survey of adaptive control technology in robotics

NASA Technical Reports Server (NTRS)

Tosunoglu, S.; Tesar, D.

1987-01-01

Previous work on the adaptive control of robotic systems is reviewed. Although the field is relatively new and does not yet represent a mature discipline, considerable attention has been given to the design of sophisticated robot controllers. Here, adaptive control methods are divided into model reference adaptive systems and self-tuning regulators with further definition of various approaches given in each class. The similarity and distinct features of the designed controllers are delineated and tabulated to enhance comparative review.

Cognitive control components and speech symptoms in people with schizophrenia.

PubMed

Becker, Theresa M; Cicero, David C; Cowan, Nelson; Kerns, John G

2012-03-30

Previous schizophrenia research suggests poor cognitive control is associated with schizophrenia speech symptoms. However, cognitive control is a broad construct. Two important cognitive control components are poor goal maintenance and poor verbal working memory storage. In the current research, people with schizophrenia (n=45) performed three cognitive tasks that varied in their goal maintenance and verbal working memory storage demands. Speech symptoms were assessed using clinical rating scales, ratings of disorganized speech from typed transcripts, and self-reported disorganization. Overall, alogia was associated with both goal maintenance and verbal working memory tasks. Objectively rated disorganized speech was associated with poor goal maintenance and with a task that included both goal maintenance and verbal working memory storage demands. In contrast, self-reported disorganization was unrelated to either amount of objectively rated disorganized speech or to cognitive control task performance, instead being associated with negative mood symptoms. Overall, our results suggest that alogia is associated with both poor goal maintenance and poor verbal working memory storage and that disorganized speech is associated with poor goal maintenance. In addition, patients' own assessment of their disorganization is related to negative mood, but perhaps not to objective disorganized speech or to cognitive control task performance. Published by Elsevier Ireland Ltd.

A comparison of design variables for control theory based airfoil optimization

NASA Technical Reports Server (NTRS)

Reuther, James; Jameson, Antony

1995-01-01

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In our previous work in the area it was shown that control theory could be employed to devise effective optimization procedures for two-dimensional profiles by using either the potential flow or the Euler equations with either a conformal mapping or a general coordinate system. We have also explored three-dimensional extensions of these formulations recently. The goal of our present work is to demonstrate the versatility of the control theory approach by designing airfoils using both Hicks-Henne functions and B-spline control points as design variables. The research also demonstrates that the parameterization of the design space is an open question in aerodynamic design.

Control of flexible beams using a free-free active truss

NASA Technical Reports Server (NTRS)

Clark, W. W.; Kimiavi, B.; Robertshaw, H. H.

1989-01-01

An analytical and experimental study involving controlling flexible beams using a free-free active truss is presented. This work extends previous work in controlling flexible continua with active trusses which were configured with fixed-free boundary conditions. The following describes the Lagrangian approach used to derive the equations of motion for the active truss and the beams attached to it. A partial-state feedback control law is derived for this system based on a full-state feedback Linear Quadratic Regulator method. The analytical model is examined via numerical simulations and the results are compared to a similar experimental apparatus described herein. The results show that control of a flexible continua is possible with a free-free active truss.

[Acute lumbago due to the manual lifting of patients in wards: prevalence and incidence data].

PubMed

Colombini, D; Cianci, E; Panciera, D; Martinelli, M; Venturi, E; Giammartini, P; Ricci, M G; Menoni, O; Battevi, N

1999-01-01

The aim of the study was to measure the occurrence (prevalence and incidence) of episodes of acute low back pain (definite effect) in a wide sample of health workers assisting disabled patients. A questionnaire was used for the study both of true acute low back pain and of episodes of ingravescent low back pain controlled pharmacologically at the onset. The questionnaire identified overall acute and pharmacologically controlled episodes occurring in the previous 12 months, both in the course of work and over the whole life of the subject. Appropriately trained operators administered the questionnaire to 551 subjects; 481 valid answer cards were obtained from 372 females and 109 males working in medical, orthopaedic and geriatric departments. 75.4% of the sample had high exposure index levels for patient lifting. The prevalence of true acute low back pain was 9% in males and 11% in females referred to the previous 12 months. Taking acute true and pharmacologically controlled low back pain together the prevalences rose to 13.8% for males and 26.9% in females. Data from the reference populations showed that acute low back pain did not exceed 3% on average in the previous year. Since work seniority in the hospital wards was known, the incidences were calculated, giving 7.9% in females and 5.29% in males for acute low back pain, and 19% in females and 3.49% in males for pharmacologically controlled low back pain. Considering the number of episodes in 100 workers/year, acute low back pain alone reached prevalences of 13-14%. This therefore appears to confirm the positive ratio between episodes of low back pain and duties involving assistance to disabled patients.

Role of a service corridor in ICU noise control, staff stress, and staff satisfaction: environmental research of an academic medical center.

PubMed

Wang, Zhe; Downs, Betsy; Farell, Ashley; Cook, Kimberly; Hourihan, Peter; McCreery, Shimby

2013-01-01

To investigate the role of a dedicated service corridor in intensive care unit (ICU) noise control and staff stress and satisfaction. Shared corridors immediately adjacent to patient rooms are generally noisy due to a variety of activities, including service deliveries and pickups. The strategy of providing a dedicated service corridor is thought to reduce noise for patient care, but the extent to which it actually contributes to noise reduction in the patient care environment and in turn improves staff performance has not been previously documented. A before-and-after comparison was conducted in an adult cardiac ICU. The ICU was relocated from a traditional hospital environment to a new addition with a dedicated service corridor. A total of 118 nursing staff participated in the surveys regarding pre-move and post-move environmental comfort, stress, and satisfaction in the previous and new units. Acoustical measures of noise within the new ICU and a control environment of the previous unit were collected during four work days, along with on-site observations of corridor traffic. Independent and paired sample t-tests of survey data showed that the perceived noise level was lower and staff reported less stress and more satisfaction in the new ICU (p < 0.01). Analyses of acoustical data confirmed that the new ICU was significantly quieter (p < 0.02). Observations revealed how the service corridor impacted patient care services and traffic. The addition of a dedicated service corridor works in the new unit for improving noise control and staff stress and satisfaction. Critical care/intensive care, noise, satisfaction, staff, work environment.

Ego Depletion Does Not Interfere With Working Memory Performance.

PubMed

Singh, Ranjit K; Göritz, Anja S

2018-01-01

Ego depletion happens if exerting self-control reduces a person's capacity to subsequently control themselves. Previous research has suggested that ego depletion not only interferes with subsequent self-control but also with working memory. However, recent meta-analytical evidence casts doubt onto this. The present study tackles the question if ego depletion does interfere with working memory performance. We induced ego depletion in two ways: using an e-crossing task and using a Stroop task. We then measured working memory performance using the letter-number sequencing task. There was no evidence of ego depletion interfering with working memory performance. Several aspects of our study render this null finding highly robust. We had a large and heterogeneous sample of N = 1,385, which provided sufficient power. We deployed established depletion tasks from two task families (e-crossing task and Stroop), thus making it less likely that the null finding is due to a specific depletion paradigm. We derived several performance scores from the working memory task and ran different analyses to maximize the chances of finding an effect. Lastly, we controlled for two potential moderators, the implicit theories about willpower and dispositional self-control capacity, to ensure that a possible effect on working memory is not obscured by an interaction effect. In sum, this experiment strengthens the position that ego depletion works but does not affect working memory performance.

Ego Depletion Does Not Interfere With Working Memory Performance

PubMed Central

Singh, Ranjit K.; Göritz, Anja S.

2018-01-01

Ego depletion happens if exerting self-control reduces a person’s capacity to subsequently control themselves. Previous research has suggested that ego depletion not only interferes with subsequent self-control but also with working memory. However, recent meta-analytical evidence casts doubt onto this. The present study tackles the question if ego depletion does interfere with working memory performance. We induced ego depletion in two ways: using an e-crossing task and using a Stroop task. We then measured working memory performance using the letter-number sequencing task. There was no evidence of ego depletion interfering with working memory performance. Several aspects of our study render this null finding highly robust. We had a large and heterogeneous sample of N = 1,385, which provided sufficient power. We deployed established depletion tasks from two task families (e-crossing task and Stroop), thus making it less likely that the null finding is due to a specific depletion paradigm. We derived several performance scores from the working memory task and ran different analyses to maximize the chances of finding an effect. Lastly, we controlled for two potential moderators, the implicit theories about willpower and dispositional self-control capacity, to ensure that a possible effect on working memory is not obscured by an interaction effect. In sum, this experiment strengthens the position that ego depletion works but does not affect working memory performance. PMID:29706923

An improved output feedback control of flexible large space structures

NASA Technical Reports Server (NTRS)

Lin, Y. H.; Lin, J. G.

1980-01-01

A special output feedback control design technique for flexible large space structures is proposed. It is shown that the technique will increase both the damping and frequency of selected modes for more effective control. It is also able to effect integrated control of elastic and rigid-body modes and, in particular, closed-loop system stability and robustness to modal truncation and parameter variation. The technique is seen as marking an improvement over previous work concerning large space structures output feedback control.

Analysis and control of the METC fluid bed gasifier. Quarterly report, April 1995--June 1995

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

NONE

1995-06-01

This document summarizes work performed for the period 4/1/95 to 7/31/95 on contract no. DE-FG21-94MC31384 (Work accomplished during the period 10/1/94 to 3/31/94 was summarized in the previous technical progress report included in the appendix of this report). In this work, three components will form the basis for design of a control scheme for the Fluidized Bed Gasifier (FBG) at METC: (1) a control systems analysis based on simple linear models derived from process data, (2) review of the literature on fluid bed gasifier operation and control, and (3) understanding of present FBG operation and real world considerations. Tasks accomplishedmore » during the present reporting period include: (1) Completion of a literature survey on Fluid Bed Gasifier control, (2) Observation of the FBG during the week of July 17 to July 21, and (3) Suggested improvements to the control of FBG backpressure and MGCR pressure.« less

Use of a Differential Observing Response to Expand Restricted Stimulus Control

ERIC Educational Resources Information Center

Walpole, Carrie Wallace; Roscoe, Eileen M.; Dube, William V.

2007-01-01

This study extends previous work on the use of differential observing responses (DOR) to remediate atypically restricted stimulus control. A participant with autism had high matching-to-sample accuracy scores with printed words that had no letters in common (e.g., "cat," "lid," "bug") but poor accuracy with words that had two letters in common…

The Extent of Working Memory Deficits Associated with Williams Syndrome: Exploration of Verbal and Spatial Domains and Executively Controlled Processes

ERIC Educational Resources Information Center

Rhodes, Sinead M.; Riby, Deborah M.; Fraser, Emma; Campbell, Lorna Elise

2011-01-01

The present study investigated verbal and spatial working memory (WM) functioning in individuals with the neuro-developmental disorder Williams syndrome (WS) using WM component tasks. While there is strong evidence of WM impairments in WS, previous research has focused on short-term memory and has neglected assessment of executive components of…

Control approach development for variable recruitment artificial muscles

NASA Astrophysics Data System (ADS)

Jenkins, Tyler E.; Chapman, Edward M.; Bryant, Matthew

2016-04-01

This study characterizes hybrid control approaches for the variable recruitment of fluidic artificial muscles with double acting (antagonistic) actuation. Fluidic artificial muscle actuators have been explored by researchers due to their natural compliance, high force-to-weight ratio, and low cost of fabrication. Previous studies have attempted to improve system efficiency of the actuators through variable recruitment, i.e. using discrete changes in the number of active actuators. While current variable recruitment research utilizes manual valve switching, this paper details the current development of an online variable recruitment control scheme. By continuously controlling applied pressure and discretely controlling the number of active actuators, operation in the lowest possible recruitment state is ensured and working fluid consumption is minimized. Results provide insight into switching control scheme effects on working fluids, fabrication material choices, actuator modeling, and controller development decisions.

Structural response synthesis

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

Ozisik, H.; Keltie, R.F.

The open loop control technique of predicting a conditioned input signal based on a specified output response for a second order system has been analyzed both analytically and numerically to gain a firm understanding of the method. Differences between this method of control and digital closed loop control using pole cancellation were investigated as a follow up to previous experimental work. Application of the technique to diamond turning using a fast tool is also discussed.

Pointing and Jitter Control for the USNA Multi-Beam Combining System

DTIC Science & Technology

2013-05-10

previous work, an adaptive H-infinity optimal controller has been developed to control a single beam using a beam position detector for feedback... turbulence and airborne particles, platform jitter, lack of feedback from the target , and current laser technology represent just a few of these...lasers. Solid state lasers, however, cannot currently provide high enough power levels to destroy a target using a single beam. On solid-state

Emotional support predicts more sickness absence and poorer self assessed work ability: a two-year prospective cohort study.

PubMed

Karlsson, Nadine; Skargren, Elisabeth; Kristenson, Margareta

2010-10-26

While back pain and stressful work environment are shown to be important causes of sickness absence the effect of psychosocial resources on sickness absence, and on self assessed work ability, is less commonly investigated. The aim of this study was to assess these associations in a two-year follow-up study. 341 working people aged 45 to 64, randomly drawn from the population, responded to a questionnaire at baseline and at a two-year follow-up. Poisson regression was used to analyse the association of psychosocial factors (psychosocial instruments on work environment, emotional support and psychological resources) and previous back pain (low back and/or neck) at baseline with sickness absence (spells and days) at follow-up, controlling for effects of age, sex, BMI, smoking, alcohol, occupation, disease and previous sickness absence. Logistic regression was used to study the associations of psychosocial factors and previous back pain at baseline with self assessed prognosis of poor work ability six months from follow-up. Finally, a multivariate analysis tested the independent effects of previous back pain and 3 psychosocial factors derived in a factor analysis: 1. work environment; 2. emotional support; 3. psychological resources, on work ability and absence days and spells. 80% of the sickness absence spells within the last 12 months before follow-up were short-term (≤ 14 days). In the final model, high emotional support predicted more sickness absence spells (RR 1.36; 1.11-1.67) and days (RR 1.68, 1.22-2.31). Previous back pain (OR 2.56; 1.13-5.81), high emotional support (OR 1.58; 1.02-2.46), and low psychological resources (OR 0.62; 0.44-0.89) were related to poorer self assessed prognosis of work ability at follow up. In a general middle aged working population high emotional support was related to more sickness absence and also poorer self assessed prognosis of work ability. Our findings suggest that both sickness absence and self assessed work ability are dependent of life outside work and can be affected by a person's close community.

Reciprocal relationship between proactive personality and work characteristics: a latent change score approach.

PubMed

Li, Wen-Dong; Fay, Doris; Frese, Michael; Harms, Peter D; Gao, Xiang Yu

2014-09-01

Previous proactivity research has predominantly assumed that proactive personality generates positive environmental changes in the workplace. Grounded in recent research on personality development from a broad interactionist theoretical approach, the present article investigates whether work characteristics, including job demands, job control, social support from supervisors and coworkers, and organizational constraints, change proactive personality over time and, more important, reciprocal relationships between proactive personality and work characteristics. Latent change score analyses based on longitudinal data collected in 3 waves across 3 years show that job demands and job control have positive lagged effects on increases in proactive personality. In addition, proactive personality exerts beneficial lagged effects on increases in job demands, job control, and supervisory support, and on decreases in organizational constraints. Dynamic reciprocal relationships are observed between proactive personality with job demands and job control. The revealed corresponsive change relationships between proactive personality and work characteristics contribute to the proactive personality literature by illuminating more nuanced interplays between the agentic person and work characteristics, and also have important practical implications for organizations and employees. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Multi-species mating disruption in Wisconsin cranberries

USDA-ARS?s Scientific Manuscript database

Previous work has shown pheromone-based mating disruption to be a promising method of pest control in cranberries. Three moth species, cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), Sparganothis fruitworm, Sparganothis sulfureana Clemens (Lepidoptera: Tortricidae), and black...

Psychosocial working conditions and weight gain among employees.

PubMed

Lallukka, T; Laaksonen, M; Martikainen, P; Sarlio-Lähteenkorva, S; Lahelma, E

2005-08-01

To study the associations between psychosocial working conditions and weight gain. Data from postal questionnaires (response rate 67%) sent to 40- to 60-y-old women (n=7093) and men (n=1799) employed by the City of Helsinki in 2000-2002 were analysed. Weight gain during the previous 12 months was the outcome variable in logistic regression analyses. Independent variables included Karasek's job demands and job control, work fatigue, working overtime, work-related mental strain, social support and the work-home interface. The final models were adjusted for age, education, marital status, physical strain and body mass index. In the previous 12 months, 25% of women and 19% of men reported weight gain. Work fatigue and working overtime were associated with weight gain in both sexes. Women who were dissatisfied with combining paid work and family life were more likely to have gained weight. Men with low job demands were less likely to have gained weight. All of these associations were independent of each other. Few work-related factors were associated with weight gain. However, our study suggests that work fatigue and working overtime are potential risk factors for weight gain. These findings need to be confirmed in prospective studies.

Combining metric episodes with semantic event concepts within the Symbolic and Sub-Symbolic Robotics Intelligence Control System (SS-RICS)

NASA Astrophysics Data System (ADS)

Kelley, Troy D.; McGhee, S.

2013-05-01

This paper describes the ongoing development of a robotic control architecture that inspired by computational cognitive architectures from the discipline of cognitive psychology. The Symbolic and Sub-Symbolic Robotics Intelligence Control System (SS-RICS) combines symbolic and sub-symbolic representations of knowledge into a unified control architecture. The new architecture leverages previous work in cognitive architectures, specifically the development of the Adaptive Character of Thought-Rational (ACT-R) and Soar. This paper details current work on learning from episodes or events. The use of episodic memory as a learning mechanism has, until recently, been largely ignored by computational cognitive architectures. This paper details work on metric level episodic memory streams and methods for translating episodes into abstract schemas. The presentation will include research on learning through novelty and self generated feedback mechanisms for autonomous systems.

Rotating shift work associated with obesity in men from northeastern Ontario

PubMed Central

Anne, Grundy; Michelle, Cotterchio; Victoria A., Kirsh; Victoria, Nadalin; Nancy, Lightfoot; Loretta, Ryan; Nancy, Kreiger

2017-01-01

Abstract Introduction: While some studies have suggested associations between shift work and obesity, few have been population-based or considered multiple shift schedules. Since obesity is linked with several chronic health conditions, understanding which types of shift work influence obesity is important and additional work with more detailed exposure assessment of shift work is warranted. Methods: Using multivariate polytomous logistic regression, we investigated the associations between shift work (evening/night, rotating and other shift schedules) and overweight and obesity as measured by body mass index cross-sectionally among 1561 men. These men had previously participated as population controls in a prostate cancer case-control study conducted in northeastern Ontario from 1995 to 1999. We obtained information on work history (including shift work), height and weight from the existing self-reported questionnaire data. Results: We observed an association for ever (vs. never) having been employed in rotating shift work for both the overweight (OR [odds ratio] = 1.34; 95% CI [confidence interval]: 1.05–1.73) and obese (OR = 1.57; 95% CI: 1.12–2.21) groups. We also observed nonsignificant associations for ever (vs. never) having been employed in permanent evening/night shifts. In addition, we found a significant trend of increased risk for both overweight and obesity with increasing duration of rotating shift work. Conclusion: Both the positive association between rotating shift work and obesity and the suggested positive association for permanent evening/night shift work in this study are consistent with previous findings. Future population-based research that is able to build on our results while examining additional shift work characteristics will further clarify whether some shift patterns have a greater impact on obesity than others. PMID:28800293

Rotating shift work associated with obesity in men from northeastern Ontario.

PubMed

Grundy, Anne; Cotterchio, Michelle; Kirsh, Victoria A; Nadalin, Victoria; Lightfoot, Nancy; Kreiger, Nancy

2017-08-01

While some studies have suggested associations between shift work and obesity, few have been population-based or considered multiple shift schedules. Since obesity is linked with several chronic health conditions, understanding which types of shift work influence obesity is important and additional work with more detailed exposure assessment of shift work is warranted. Using multivariate polytomous logistic regression, we investigated the associations between shift work (evening/night, rotating and other shift schedules) and overweight and obesity as measured by body mass index cross-sectionally among 1561 men. These men had previously participated as population controls in a prostate cancer case-control study conducted in northeastern Ontario from 1995 to 1999. We obtained information on work history (including shift work), height and weight from the existing self-reported questionnaire data. We observed an association for ever (vs. never) having been employed in rotating shift work for both the overweight (OR [odds ratio] = 1.34; 95% CI [confidence interval]: 1.05-1.73) and obese (OR = 1.57; 95% CI: 1.12-2.21) groups. We also observed nonsignificant associations for ever (vs. never) having been employed in permanent evening/night shifts. In addition, we found a significant trend of increased risk for both overweight and obesity with increasing duration of rotating shift work. Both the positive association between rotating shift work and obesity and the suggested positive association for permanent evening/night shift work in this study are consistent with previous findings. Future population-based research that is able to build on our results while examining additional shift work characteristics will further clarify whether some shift patterns have a greater impact on obesity than others.

Shared processing in multiple object tracking and visual working memory in the absence of response order and task order confounds

PubMed Central

Howe, Piers D. L.

2017-01-01

To understand how the visual system represents multiple moving objects and how those representations contribute to tracking, it is essential that we understand how the processes of attention and working memory interact. In the work described here we present an investigation of that interaction via a series of tracking and working memory dual-task experiments. Previously, it has been argued that tracking is resistant to disruption by a concurrent working memory task and that any apparent disruption is in fact due to observers making a response to the working memory task, rather than due to competition for shared resources. Contrary to this, in our experiments we find that when task order and response order confounds are avoided, all participants show a similar decrease in both tracking and working memory performance. However, if task and response order confounds are not adequately controlled for we find substantial individual differences, which could explain the previous conflicting reports on this topic. Our results provide clear evidence that tracking and working memory tasks share processing resources. PMID:28410383

Shared processing in multiple object tracking and visual working memory in the absence of response order and task order confounds.

PubMed

Lapierre, Mark D; Cropper, Simon J; Howe, Piers D L

2017-01-01

To understand how the visual system represents multiple moving objects and how those representations contribute to tracking, it is essential that we understand how the processes of attention and working memory interact. In the work described here we present an investigation of that interaction via a series of tracking and working memory dual-task experiments. Previously, it has been argued that tracking is resistant to disruption by a concurrent working memory task and that any apparent disruption is in fact due to observers making a response to the working memory task, rather than due to competition for shared resources. Contrary to this, in our experiments we find that when task order and response order confounds are avoided, all participants show a similar decrease in both tracking and working memory performance. However, if task and response order confounds are not adequately controlled for we find substantial individual differences, which could explain the previous conflicting reports on this topic. Our results provide clear evidence that tracking and working memory tasks share processing resources.

Determinants of Chronic Respiratory Symptoms among Pharmaceutical Factory Workers

PubMed Central

Enquselassie, Fikre; Tefera, Yifokire; Gizaw, Muluken; Wakuma, Samson; Woldemariam, Messay

2018-01-01

Background Chronic respiratory symptoms including chronic cough, chronic phlegm, wheezing, shortness of breath, and chest pain are manifestations of respiratory problems which are mainly evolved as a result of occupational exposures. This study aims to assess determinants of chronic respiratory symptoms among pharmaceutical factory workers. Methods A case control study was carried out among 453 pharmaceutical factory workers with 151 cases and 302 controls. Data was collected using pretested and structured questionnaire. The data was analyzed using descriptive statistics and bivariate and multivariate analysis. Result Previous history of chronic respiratory diseases (AOR = 3.36, 95% CI = 1.85–6.12), family history of chronic respiratory diseases (AOR = 2.55, 95% CI = 1.51–4.32), previous dusty working environment (AOR = 2.26, 95% CI = 1.07–4.78), ever smoking (AOR = 3.66, 95% CI = 1.05–12.72), and service years (AOR = 1.86, 95% CI = 1.16–2.99) showed statistically significant association with chronic respiratory symptoms. Conclusion Previous history of respiratory diseases, family history of chronic respiratory diseases, previous dusty working environment, smoking, and service years were determinants of chronic respiratory symptoms. Public health endeavors to prevent the burden of chronic respiratory symptoms among pharmaceutical factory workers should target the reduction of adverse workplace exposures and discouragement of smoking. PMID:29666655

Keeping priorities: the role of working memory and selective attention in cognitive aging.

PubMed

de Fockert, Jan W

2005-11-02

Cognitive aging is associated with impairments to working memory and top-down control in selective attention, two components of cognitive control associated with the frontal lobes. Recent findings indicate that working memory and selective attention may be interdependent, making a better understanding of their involvement in cognitive aging particularly challenging. A paper in a recent issue of Nature Neuroscience has provided evidence that a reduction in the ability to keep a clear distinction between information to be stored in working memory and information that should be ignored and subsequently suppressed is associated with poor working memory performance. These results are in line with previous evidence for a specific age-related impairment in the ability to separate irrelevant from relevant information and may be able to explain a range of age-related cognitive changes.

Return to work after work-related stress: a randomized controlled trial of a work-focused cognitive behavioral intervention.

PubMed

Dalgaard, Vita Ligaya; Aschbacher, Kirstin; Andersen, Johan Hviid; Glasscock, David John; Willert, Morten Vejs; Carstensen, Ole; Biering, Karin

2017-09-01

Objectives This study aimed to evaluate the effect of a stress management intervention (SMI) on lasting return to work (RTW) among patients with work-related stress complaints. Methods Sickness benefit departments from three local municipalities referred patients on sick leave with work-related adjustment disorders or mild depression to the Department of Occupational Medicine, Regional Hospital West Jutland. A 2× randomization procedure allocated patients into one of three groups: intervention (N=58), control A (which received a clinical assessment; N=56), or control B (no assessment; N=49). Treatment comprised individual work-focused cognitive behavioral therapy (CBT) with an optional workplace intervention. The outcome was time until lasting RTW (16 and 44 weeks follow-up) using register data. Results Median number of weeks until lasting RTW was 15, 19, and 32 for the intervention group, control A, and control B respectively. However, for group B, clinical assessment was not part of the inclusion process, which may have introduced selection bias. In the fully-adjusted Cox regression model, the intervention group exhibited significantly faster lasting RTW at 44 weeks; hazard ratio (HR) 1.57 [95% confidence interval (95% CI) 1.01-2.44] relative to control group A, with a non-significant trend evident at 16 weeks; HR 1.70 (95% CI 0.94-3.10), when controlling for age, gender, occupation, sick leave during previous year, full or partial sick leave, and diagnosis. Unadjusted analyses remained directionally consistent but were reduced to marginal significance. Conclusions There was a tendency towards faster lasting RTW in the intervention group compared to control A, which received clinical assessment, in all analyses. The intervention group returned to work about 4 weeks earlier than control A, which could translate into substantial financial gains.

Bio-inspired network optimization in soft materials — Insights from the plant cell wall

NASA Astrophysics Data System (ADS)

Vincent, R. R.; Cucheval, A.; Hemar, Y.; Williams, M. A. K.

2009-01-01

The dynamic-mechanical responses of ionotropic gels made from the biopolymer pectin have recently been investigated by microrheological experiments and found to exhibit behaviour indicative of semi-flexible polymer networks. In this work we investigate the gelling behaviour of pectin systems in which an enzyme (pectinmethylesterase, PME) is used to liberate ion-binding sites on initially inert polymers, while in the presence of ions. This is in contrast to the previous work, where it was the release of ions (rather than ion-binding groups) that was controlled and the polymers had pre-existing cross-linkable moieties. In stark contrast to the semi-flexible network paradigm of biological gels and the previous work on pectin, the gels studied herein exhibit the properties of chemically cross-linked networks of flexible polymers.

Technology development for lunar base water recycling

NASA Technical Reports Server (NTRS)

Schultz, John R.; Sauer, Richard L.

1992-01-01

This paper will review previous and ongoing work in aerospace water recycling and identify research activities required to support development of a lunar base. The development of a water recycle system for use in the life support systems envisioned for a lunar base will require considerable research work. A review of previous work on aerospace water recycle systems indicates that more efficient physical and chemical processes are needed to reduce expendable and power requirements. Development work on biological processes that can be applied to microgravity and lunar environments also needs to be initiated. Biological processes are inherently more efficient than physical and chemical processes and may be used to minimize resupply and waste disposal requirements. Processes for recovering and recycling nutrients such as nitrogen, phosphorus, and sulfur also need to be developed to support plant growth units. The development of efficient water quality monitors to be used for process control and environmental monitoring also needs to be initiated.

A Randomized Clinical Trial of Cogmed Working Memory Training in School-Age Children with ADHD: A Replication in a Diverse Sample Using a Control Condition

ERIC Educational Resources Information Center

Chacko, A.; Bedard, A. C.; Marks, D. J.; Feirsen, N.; Uderman, J. Z.; Chimiklis, A.; Rajwan, E.; Cornwell, M.; Anderson, L.; Zwilling, A.; Ramon, M.

2014-01-01

Background: Cogmed Working Memory Training (CWMT) has received considerable attention as a promising intervention for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) in children. At the same time, methodological weaknesses in previous clinical trials call into question reported efficacy of CWMT. In particular, lack of equivalence…

System-theoretic Interpretation of the Mode Sensing Hypothesis

DTIC Science & Technology

2014-08-01

estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the...6. AUTHOR(S) Prof. Rafal Zbikowski Prof. Graham Taylor 5d. PROJECT NUMBER 5d. TASK NUMBER 5e. WORK UNIT NUMBER 7. PERFORMING...insect flight control has more recently been modelled. The approach that we adopt here differs from previous, related work in several fundamental

Passive vs. Active Control of Rhythmic Ball Bouncing: The Role of Visual Information

ERIC Educational Resources Information Center

Siegler, Isabelle A.; Bardy, Benoit G.; Warren, William H.

2010-01-01

The simple task of bouncing a ball on a racket offers a model system for studying how human actors exploit the physics and information of the environment to control their behavior. Previous work shows that people take advantage of a passively stable solution for ball bouncing but can also use perceptual information to actively stabilize bouncing.…

A biologically inspired meta-control navigation system for the Psikharpax rat robot.

PubMed

Caluwaerts, K; Staffa, M; N'Guyen, S; Grand, C; Dollé, L; Favre-Félix, A; Girard, B; Khamassi, M

2012-06-01

A biologically inspired navigation system for the mobile rat-like robot named Psikharpax is presented, allowing for self-localization and autonomous navigation in an initially unknown environment. The ability of parts of the model (e.g. the strategy selection mechanism) to reproduce rat behavioral data in various maze tasks has been validated before in simulations. But the capacity of the model to work on a real robot platform had not been tested. This paper presents our work on the implementation on the Psikharpax robot of two independent navigation strategies (a place-based planning strategy and a cue-guided taxon strategy) and a strategy selection meta-controller. We show how our robot can memorize which was the optimal strategy in each situation, by means of a reinforcement learning algorithm. Moreover, a context detector enables the controller to quickly adapt to changes in the environment-recognized as new contexts-and to restore previously acquired strategy preferences when a previously experienced context is recognized. This produces adaptivity closer to rat behavioral performance and constitutes a computational proposition of the role of the rat prefrontal cortex in strategy shifting. Moreover, such a brain-inspired meta-controller may provide an advancement for learning architectures in robotics.

Relationships of job hazards, lack of knowledge, alcohol use, health status and risk taking behavior to work injury of coal miners: a case-control study in India.

PubMed

Kunar, Bijay Mihir; Bhattacherjee, Ashis; Chau, Nearkasen

2008-01-01

Objective is to assess the relationships of job hazards, individual characteristics, and risk taking behavior to occupational injuries of coal miners. This case-control study compared 245 male underground coal miners with injury during the previous two-year period with 330 matched controls without injury during the previous five years. Data were collected via face-to-face interview and analyzed using the conditional logistic model. Handling material, poor environmental/working conditions, and geological/strata control- related hazards were the main risk factors: adjusted ORs 5.15 (95% CI 2.42-10.9), 2.40 (95% CI 1.29-4.47), and 2.25 (95% CI 1.24-4.07) respectively. Their roles were higher among the face-workers than among the non-face-workers. No formal education, alcohol consumption, disease, big-family, and risk-taking behavior were associated with injuries (2.36

Meditation awareness training for the treatment of workaholism: A controlled trial.

PubMed

Van Gordon, William; Shonin, Edo; Dunn, Thomas J; Garcia-Campayo, Javier; Demarzo, Marcelo M P; Griffiths, Mark D

2017-06-01

Background and aims Workaholism is a form of behavioral addiction that can lead to reduced life and job satisfaction, anxiety, depression, burnout, work-family conflict, and impaired productivity. Given the number of people affected, there is a need for more targeted workaholism treatments. Findings from previous case studies successfully utilizing second-generation mindfulness-based interventions (SG-MBIs) for treating behavioral addiction suggest that SG-MBIs may be suitable for treating workaholism. This study conducted a controlled trial to investigate the effects of an SG-MBI known as meditation awareness training (MAT) on workaholism. Methods Male and female adults suffering from workaholism (n = 73) were allocated to MAT or a waiting-list control group. Assessments were performed at pre-, post-, and 3-month follow-up phases. Results MAT participants demonstrated significant and sustained improvements over control-group participants in workaholism symptomatology, job satisfaction, work engagement, work duration, and psychological distress. Furthermore, compared to the control group, MAT participants demonstrated a significant reduction in hours spent working but without a decline in job performance. Discussion and conclusions MAT may be a suitable intervention for treating workaholism. Further controlled intervention studies investigating the effects of SG-MBIs on workaholism are warranted.

Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review

PubMed Central

Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

2016-01-01

According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. PMID:27178844

Insecticide Resistance and Malaria Vector Control: The Importance of Fitness Cost Mechanisms in Determining Economically Optimal Control Trajectories

PubMed Central

Brown, Zachary S.; Dickinson, Katherine L.; Kramer, Randall A.

2014-01-01

The evolutionary dynamics of insecticide resistance in harmful arthropods has economic implications, not only for the control of agricultural pests (as has been well studied), but also for the control of disease vectors, such as malaria-transmitting Anopheles mosquitoes. Previous economic work on insecticide resistance illustrates the policy relevance of knowing whether insecticide resistance mutations involve fitness costs. Using a theoretical model, this article investigates economically optimal strategies for controlling malaria-transmitting mosquitoes when there is the potential for mosquitoes to evolve resistance to insecticides. Consistent with previous literature, we find that fitness costs are a key element in the computation of economically optimal resistance management strategies. Additionally, our models indicate that different biological mechanisms underlying these fitness costs (e.g., increased adult mortality and/or decreased fecundity) can significantly alter economically optimal resistance management strategies. PMID:23448053

Application of electrohydrodynamic phenomena to space processing

NASA Technical Reports Server (NTRS)

Jones, T. B.

1975-01-01

The capabilities of electrohydrodynamic (EHD) unit separation, liquid handling/control, and mixing are introduced to industrial chemists and metallurgists, working on specific zero-gravity processes. Previously proposed zero-gravity applications of EHD are presented along with the prominent electrohydrodynamical force effects.

Optimal management of non-Markovian biological populations

USGS Publications Warehouse

Williams, B.K.

2007-01-01

Wildlife populations typically are described by Markovian models, with population dynamics influenced at each point in time by current but not previous population levels. Considerable work has been done on identifying optimal management strategies under the Markovian assumption. In this paper we generalize this work to non-Markovian systems, for which population responses to management are influenced by lagged as well as current status and/or controls. We use the maximum principle of optimal control theory to derive conditions for the optimal management such a system, and illustrate the effects of lags on the structure of optimal habitat strategies for a predator-prey system.

Creep, Fatigue and Environmental Interactions and Their Effect on Crack Growth in Superalloys

NASA Technical Reports Server (NTRS)

Telesman, J.; Gabb, T. P.; Ghosn, L. J.; Smith, T.

2017-01-01

Complex interactions of creep/fatigue/environment control dwell fatigue crack growth (DFCG) in superalloys. Crack tip stress relaxation during dwells significantly changes the crack driving force and influence DFCG. Linear Elastic Fracture Mechanics, Kmax, parameter unsuitable for correlating DFCG behavior due to extensive visco-plastic deformation. Magnitude of remaining crack tip axial stresses controls DFCG resistance due to the brittle-intergranular nature of the crack growth process. Proposed a new empirical parameter, Ksrf, which incorporates visco-plastic evolution of the magnitude of remaining crack tip stresses. Previous work performed at 704C, extend the work to 760C.

Helicopter Fuselage Active Flow Control in the Presence of a Rotor

NASA Technical Reports Server (NTRS)

Martin, Preston B; Overmeyer, Austin D.; Tanner, Philip E.; Wilson, Jacob S.; Jenkins, Luther N.

2014-01-01

This work extends previous investigations of active flow control for helicopter fuselage drag and download reduction to include the effects of the rotor. The development of the new wind tunnel model equipped with fluidic oscillators is explained in terms of the previous test results. Large drag reductions greater than 20% in some cases were measured during powered testing without increasing, and in some cases decreasing download in forward flight. As confirmed by Particle Image Velocimetry (PIV), the optimum actuator configuration that provided a decrease in both drag and download appeared to create a virtual (fluidic) boat-tail fairing instead of attaching flow to the ramp surface. This idea of a fluidic fairing shifts the focus of 3D separation control behind bluff bodies from controlling/reattaching surface boundary layers to interacting with the wake flow.

Exposure to crystalline silica at Alberta work sites: review of controls.

PubMed

Radnoff, Diane; Todor, Maria S; Beach, Jeremy

2015-01-01

From 2009 to 2013, Alberta Jobs, Skills, Training, and Labour (JSTL) conducted a project to evaluate exposure to crystalline silica and assess controls to protect workers. Information on exposure results has been previously reported; this article discusses the data collected on workplace controls. Information on work site controls was collected during exposure assessments consisting of qualitative information on controls in place and used by workers at the time of the assessments. Where there was sufficient data, the information was further analyzed to evaluate the impact of a particular control. While many types of controls were observed, they were not always effective or in use. The control available most often was respiratory protective equipment (RPE). Generally, when respirators were used, they were correctly selected for the level of measured exposure. However, not all workers who were potentially overexposed wore respirators at the time of the assessments. When the use of respirators was taken into account, about one-third of workers were still potentially exposed over the Alberta occupational exposure limit. The industries with the highest levels of exposure tended to be those with the most unprotected workers. Issues were identified with the use of improper work practices such as dry cleaning methods, lack of documented work procedures, poor housekeeping, and lack of training which may have contributed to worker exposure levels. There is a wide range in the efficacy of controls, particularly engineering controls. Most of the literature focuses on engineering controls; however administrative controls also play a role in reducing worker exposure. Data collected in this work indicated that simple changes to work procedures and behavior (such as improved housekeeping) may be effective, low-cost ways to reduce workplace exposure. More study is required to evaluate the impact and efficacy of administrative controls such as housekeeping and training. Employers must select and evaluate controls in the context of overall workplace health and safety programs and ensure that they are supported by supervision, good work practices. and training.

The Persistence of the Gender Gap in Introductory Physics

NASA Astrophysics Data System (ADS)

Kost, Lauren E.; Pollock, Steven J.; Finkelstein, Noah D.

2008-10-01

We previously showed[l] that despite teaching with interactive engagement techniques, the gap in performance between males and females on conceptual learning surveys persisted from pre- to posttest, at our institution. Such findings were counter to previously published work[2]. Our current work analyzes factors that may influence the observed gender gap in our courses. Posttest conceptual assessment data are modeled using both multiple regression and logistic regression analyses to estimate the gender gap in posttest scores after controlling for background factors that vary by gender. We find that at our institution the gender gap persists in interactive physics classes, but is largely due to differences in physics and math preparation and incoming attitudes and beliefs.

Supervisory control based on minimal cuts and Petri net sub-controllers coordination

NASA Astrophysics Data System (ADS)

Rezig, Sadok; Achour, Zied; Rezg, Nidhal; Kammoun, Mohamed-Ali

2016-10-01

This paper addresses the synthesis of Petri net (PN) controller for the forbidden state transition problem with a new utilisation of the theory of regions. Moreover, as any method of control synthesis based on a reachability graph, the theory of regions suffers from the combinatorial explosion problem. The proposed work minimises the number of equations in the linear system of theory of regions and therefore one can reduce the computation time. In this paper, two different approaches are proposed to select minimal cuts in the reachability graph in order to synthesise a PN controller. Thanks to a switch from one cut to another, one can activate and deactivate the corresponding PNcontroller. An application is implemented in a flexible manufacturing system to illustrate the present method. Finally, comparison with previous works with experimental results in obtaining a maximally permissive controller is presented.

Department of Defense Office of the Inspector General FY 2013 Audit Plan

DTIC Science & Technology

2012-11-01

oversight procedures to review KPMG LLPs work; and if applicable disclose instances where KPMG LLP does not comply, in all material respects, with U.S...decisions. Pervasive material internal control weaknesses impact the accuracy, reliability and timeliness of budgetary and accounting data and...reported the same 13 material internal control weaknesses as in the previous year. These pervasive and longstanding financial management challenges

Cancer 'survivor-care': II. Disruption of prefrontal brain activation top-down control of working memory capacity as possible mechanism for chemo-fog/brain (chemotherapy-associated cognitive impairment).

PubMed

Raffa, R B

2013-08-01

Cancer chemotherapy-associated cognitive impairments (termed 'chemo-fog' or 'chemo-brain'), particularly in memory, have been self-reported or identified in cancer survivors previously treated with chemotherapy. Although a variety of deficits have been detected, a consistent theme is a detriment in visuospatial working memory. The parietal cortex, a major site of storage of such memory, is implicated in chemotherapy-induced damage. However, if the findings of two recent publications are combined, the (pre)frontal cortex might be an equally viable target. Two recent studies, one postulating a mechanism for 'top-down control' of working memory capacity and another visualizing chemotherapy-induced alterations in brain activation during working memory processing, are reviewed and integrated. A computational model and the proposal that the prefrontal cortex plays a role in working memory via top-down control of parietal working memory capacity is consistent with a recent demonstration of decreased frontal hyperactivation following chemotherapy. Chemotherapy-associated impairment of visuospatial working memory might include the (pre)frontal cortex in addition to the parietal cortex. This provides new opportunity for basic science and clinical investigation. © 2013 John Wiley & Sons Ltd.

Cognitive control of familiarity: directed forgetting reduces proactive interference in working memory.

PubMed

Festini, Sara B; Reuter-Lorenz, Patricia A

2014-03-01

Proactive interference (PI) occurs when previously learned information interferes with new learning. In a working memory task, PI induces longer response times and more errors to recent negative probes than to new probes, presumably because the recent probe's familiarity invites a "yes" response. Warnings, longer intertrial intervals, and the increased contextual salience of the probes can reduce but not eliminate PI, suggesting that cognitive control over PI is limited. Here we tested whether control exerted in the form of intentional forgetting performed during working memory can reduce the magnitude of PI. In two experiments, participants performed a working memory task with directed-forgetting instructions and the occasional presentation of recent probes. Surprise long-term memory testing indicated better memory for to-be-remembered than for to-be-forgotten items, documenting the classic directed-forgetting effect. Critically, in working memory, PI was virtually eliminated for recent probes from prior to-be-forgotten lists, as compared to recent probes from prior to-be-remembered lists. Thus cognitive control, when executed via directed forgetting, can reduce the adverse and otherwise persistent interference from familiarity, an effect that we attribute to attenuated memory representations of the to-be-forgotten items.

Altered Error-Related Activity in Patients with Schizophrenia

ERIC Educational Resources Information Center

Koch, Kathrin; Wagner, Gerd; Schultz, Christoph; Schachtzabel, Claudia; Nenadic, Igor; Axer, Martina; Reichenbach, Jurgen R.; Sauer, Heinrich; Schlosser, Ralf G. M.

2009-01-01

Deficits in working memory (WM) and executive cognitive control are core features of schizophrenia. However, findings regarding functional activation strengths are heterogeneous, partly due to differences in task demands and behavioral performance. Previous investigators proposed integrating these heterogeneous findings into a comprehensive model…

Learning to walk with an adaptive gain proportional myoelectric controller for a robotic ankle exoskeleton.

PubMed

Koller, Jeffrey R; Jacobs, Daniel A; Ferris, Daniel P; Remy, C David

2015-11-04

Robotic ankle exoskeletons can provide assistance to users and reduce metabolic power during walking. Our research group has investigated the use of proportional myoelectric control for controlling robotic ankle exoskeletons. Previously, these controllers have relied on a constant gain to map user's muscle activity to actuation control signals. A constant gain may act as a constraint on the user, so we designed a controller that dynamically adapts the gain to the user's myoelectric amplitude. We hypothesized that an adaptive gain proportional myoelectric controller would reduce metabolic energy expenditure compared to walking with the ankle exoskeleton unpowered because users could choose their preferred control gain. We tested eight healthy subjects walking with the adaptive gain proportional myoelectric controller with bilateral ankle exoskeletons. The adaptive gain was updated each stride such that on average the user's peak muscle activity was mapped to maximal power output of the exoskeleton. All subjects participated in three identical training sessions where they walked on a treadmill for 50 minutes (30 minutes of which the exoskeleton was powered) at 1.2 ms(-1). We calculated and analyzed metabolic energy consumption, muscle recruitment, inverse kinematics, inverse dynamics, and exoskeleton mechanics. Using our controller, subjects achieved a metabolic reduction similar to that seen in previous work in about a third of the training time. The resulting controller gain was lower than that seen in previous work (β=1.50±0.14 versus a constant β=2). The adapted gain allowed users more total ankle joint power than that of unassisted walking, increasing ankle power in exchange for a decrease in hip power. Our findings indicate that humans prefer to walk with greater ankle mechanical power output than their unassisted gait when provided with an ankle exoskeleton using an adaptive controller. This suggests that robotic assistance from an exoskeleton can allow humans to adopt gait patterns different from their normal choices for locomotion. In our specific experiment, subjects increased ankle power and decreased hip power to walk with a reduction in metabolic cost. Future exoskeleton devices that rely on proportional myolectric control are likely to demonstrate improved performance by including an adaptive gain.

Return to work after vocational rehabilitation for sick-listed workers with long-term back, neck and shoulder problems: A follow-up study of factors involved.

PubMed

Rinaldo, Ulrika; Selander, John

2016-09-27

Absence from work due to musculoskeletal disorders is a significant problem from a number of perspectives, and there is a great need to identify factors that facilitate return to work (RTW). To identify factors related to RTW after vocational rehabilitation for sick-listed workers with long-term back, neck and/or shoulder problems, and to compare the results with those from a previous literature review based on studies from 1980 to 2000. A literature review based on studies published 2001-2014 in PubMed, CINAHL, EMBASE, ERIC and the Cochrane Library. Major risk factors for not returning to work are: higher age, factors related to pain such as higher levels of pain and pain related fear, avoidance of activity, high distress and depression. Facilitating factors for RTW are: lower functional disability, gaining control over one's own condition, believing in RTW and work-related factors such as occupational training, and having a job coach or an RTW coordinator. Compared with the results from the previous review, the present review shows less of a focus on sociodemographic factors and more on psychological factors. Both studies highlight risk factors such as older age, higher levels of pain, depression and less internal locus of control. Psychosocial and work-related factors are important and should be included in interventions for the RTW of people with long-term back, neck and/or shoulder problems.

Research in robust control for hypersonic aircraft

NASA Technical Reports Server (NTRS)

Calise, A. J.

1994-01-01

The research during the third reporting period focused on fixed order robust control design for hypersonic vehicles. A new technique was developed to synthesize fixed order H(sub infinity) controllers. A controller canonical form is imposed on the compensator structure and a homotopy algorithm is employed to perform the controller design. Various reduced order controllers are designed for a simplified version of the hypersonic vehicle model used in our previous studies to demonstrate the capabilities of the code. However, further work is needed to investigate the issue of numerical ill-conditioning for large order systems and to make the numerical approach more reliable.

Introducing a new semi-active engine mount using force controlled variable stiffness

NASA Astrophysics Data System (ADS)

Azadi, Mojtaba; Behzadipour, Saeed; Faulkner, Gary

2013-05-01

This work introduces a new concept in designing semi-active engine mounts. Engine mounts are under continuous development to provide better and more cost-effective engine vibration control. Passive engine mounts do not provide satisfactory solution. Available semi-active and active mounts provide better solutions but they are more complex and expensive. The variable stiffness engine mount (VSEM) is a semi-active engine mount with a simple ON-OFF control strategy. However, unlike available semi-active engine mounts that work based on damping change, the VSEM works based on the static stiffness change by using a new fast response force controlled variable spring. The VSEM is an improved version of the vibration mount introduced by the authors in their previous work. The results showed significant performance improvements over a passive rubber mount. The VSEM also provides better vibration control than a hydromount at idle speed. Low hysteresis and the ability to be modelled by a linear model in low-frequency are the advantages of the VSEM over the vibration isolator introduced earlier and available hydromounts. These specifications facilitate the use of VSEM in the automotive industry, however, further evaluation and developments are needed for this purpose.

Decreased prefrontal functional brain response during memory testing in women with Cushing's syndrome in remission.

PubMed

Ragnarsson, Oskar; Stomby, Andreas; Dahlqvist, Per; Evang, Johan A; Ryberg, Mats; Olsson, Tommy; Bollerslev, Jens; Nyberg, Lars; Johannsson, Gudmundur

2017-08-01

Neurocognitive dysfunction is an important feature of Cushing's syndrome (CS). Our hypothesis was that patients with CS in remission have decreased functional brain responses in the prefrontal cortex and hippocampus during memory testing. In this cross-sectional study we included 19 women previously treated for CS and 19 controls matched for age, gender, and education. The median remission time was 7 (IQR 6-10) years. Brain activity was studied with functional magnetic resonance imaging during episodic- and working-memory tasks. The primary regions of interest were the prefrontal cortex and the hippocampus. A voxel-wise comparison of functional brain responses in patients and controls was performed. During episodic-memory encoding, patients displayed lower functional brain responses in the left and right prefrontal gyrus (p<0.001) and in the right inferior occipital gyrus (p<0.001) compared with controls. There was a trend towards lower functional brain responses in the left posterior hippocampus in patients (p=0.05). During episodic-memory retrieval, the patients displayed lower functional brain responses in several brain areas with the most predominant difference in the right prefrontal cortex (p<0.001). During the working memory task, patients had lower response in the prefrontal cortices bilaterally (p<0.005). Patients, but not controls, had lower functional brain response during a more complex working memory task compared with a simpler one. In conclusion, women with CS in long-term remission have reduced functional brain responses during episodic and working memory testing. This observation extends previous findings showing long-term adverse effects of severe hypercortisolaemia on brain function. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selective transfer of visual working memory training on Chinese character learning.

PubMed

Opitz, Bertram; Schneiders, Julia A; Krick, Christoph M; Mecklinger, Axel

2014-01-01

Previous research has shown a systematic relationship between phonological working memory capacity and second language proficiency for alphabetic languages. However, little is known about the impact of working memory processes on second language learning in a non-alphabetic language such as Mandarin Chinese. Due to the greater complexity of the Chinese writing system we expect that visual working memory rather than phonological working memory exerts a unique influence on learning Chinese characters. This issue was explored in the present experiment by comparing visual working memory training with an active (auditory working memory training) control condition and a passive, no training control condition. Training induced modulations in language-related brain networks were additionally examined using functional magnetic resonance imaging in a pretest-training-posttest design. As revealed by pre- to posttest comparisons and analyses of individual differences in working memory training gains, visual working memory training led to positive transfer effects on visual Chinese vocabulary learning compared to both control conditions. In addition, we found sustained activation after visual working memory training in the (predominantly visual) left infero-temporal cortex that was associated with behavioral transfer. In the control conditions, activation either increased (active control condition) or decreased (passive control condition) without reliable behavioral transfer effects. This suggests that visual working memory training leads to more efficient processing and more refined responses in brain regions involved in visual processing. Furthermore, visual working memory training boosted additional activation in the precuneus, presumably reflecting mental image generation of the learned characters. We, therefore, suggest that the conjoint activity of the mid-fusiform gyrus and the precuneus after visual working memory training reflects an interaction of working memory and imagery processes with complex visual stimuli that fosters the coherent synthesis of a percept from a complex visual input in service of enhanced Chinese character learning. © 2013 Published by Elsevier Ltd.

Effective Coping With Supervisor Conflict Depends on Control: Implications for Work Strains.

PubMed

Eatough, Erin M; Chang, Chu-Hsiang

2018-01-11

This study examined the interactive effects of interpersonal conflict at work, coping strategy, and perceived control specific to the conflict on employee work strain using multisource and time-lagged data across two samples. In Sample 1, multisource data was collected from 438 employees as well as data from participant-identified secondary sources (e.g., significant others, best friends). In Sample 2, time-lagged data from 100 full-time employees was collected in a constructive replication. Overall, findings suggested that the success of coping efforts as indicated by lower strains hinges on the combination of the severity of the stressor, perceived control over the stressor, and coping strategy used (problem-focused vs. emotion-focused coping). Results from the current study provide insights for why previous efforts to document the moderating effects of coping have been inconsistent, especially with regards to emotion-focused coping. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Effect of workplace incivility on end-of-work negative affect: examining individual and organizational moderators in a daily diary study.

PubMed

Zhou, Zhiqing E; Yan, Yu; Che, Xin Xuan; Meier, Laurenz L

2015-01-01

Although previous studies have linked workplace incivility with various negative outcomes, they mainly focused on the long-term effects of chronic exposure to workplace incivility, whereas targets' short-term reactions to incivility episodes have been largely neglected. Using a daily diary design, the current study examined effects of daily workplace incivility on end-of-work negative affect and explored potential individual and organizational moderators. Data collected from 76 full-time employees across 10 consecutive working days revealed that daily workplace incivility positively predicted end-of-work negative affect while controlling for before-work negative affect. Further, the relationship was stronger for people with low emotional stability, high hostile attribution bias, external locus of control, and people experiencing low chronic workload and more chronic organizational constraints, as compared with people with high emotional stability, low hostile attribution bias, internal locus of control, and people experiencing high chronic workload and fewer chronic organizational constraints, respectively. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PsycINFO Database Record (c) 2014 APA, all rights reserved.

The scope and control of attention as separate aspects of working memory.

PubMed

Shipstead, Zach; Redick, Thomas S; Hicks, Kenny L; Engle, Randall W

2012-01-01

The present study examines two varieties of working memory (WM) capacity task: visual arrays (i.e., a measure of the amount of information that can be maintained in working memory) and complex span (i.e., a task that taps WM-related attentional control). Using previously collected data sets we employ confirmatory factor analysis to demonstrate that visual arrays and complex span tasks load on separate, but correlated, factors. A subsequent series of structural equation models and regression analyses demonstrate that these factors contribute both common and unique variance to the prediction of general fluid intelligence (Gf). However, while visual arrays does contribute uniquely to higher cognition, its overall correlation to Gf is largely mediated by variance associated with the complex span factor. Thus we argue that visual arrays performance is not strictly driven by a limited-capacity storage system (e.g., the focus of attention; Cowan, 2001), but may also rely on control processes such as selective attention and controlled memory search.

Individual Differences in Working Memory Capacity Predict Retrieval-Induced Forgetting

ERIC Educational Resources Information Center

Aslan, Alp; Bauml, Karl-Heinz T.

2011-01-01

Selectively retrieving a subset of previously studied information enhances memory for the retrieved information but causes forgetting of related, nonretrieved information. Such retrieval-induced forgetting (RIF) has often been attributed to inhibitory executive-control processes that supposedly suppress the nonretrieved items' memory…

Output-feedback control of combined sewer networks through receding horizon control with moving horizon estimation

NASA Astrophysics Data System (ADS)

Joseph-Duran, Bernat; Ocampo-Martinez, Carlos; Cembrano, Gabriela

2015-10-01

An output-feedback control strategy for pollution mitigation in combined sewer networks is presented. The proposed strategy provides means to apply model-based predictive control to large-scale sewer networks, in-spite of the lack of measurements at most of the network sewers. In previous works, the authors presented a hybrid linear control-oriented model for sewer networks together with the formulation of Optimal Control Problems (OCP) and State Estimation Problems (SEP). By iteratively solving these problems, preliminary Receding Horizon Control with Moving Horizon Estimation (RHC/MHE) results, based on flow measurements, were also obtained. In this work, the RHC/MHE algorithm has been extended to take into account both flow and water level measurements and the resulting control loop has been extensively simulated to assess the system performance according different measurement availability scenarios and rain events. All simulations have been carried out using a detailed physically based model of a real case-study network as virtual reality.

Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review.

PubMed

Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

2016-07-01

According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

An alternative experimental case-control design for genetic association studies on bovine mastitis.

PubMed

Biffani, S; Del Corvo, M; Capoferri, R; Pedretti, A; Luini, M; Williams, J L; Pagnacco, G; Minvielle, F; Minozzi, G

2017-04-01

The possibility of using genetic control strategies to increase disease resistance to infectious diseases relies on the identification of markers to include in the breeding plans. Possible incomplete exposure of mastitis-free (control) animals, however, is a major issue to find relevant markers in genetic association studies for infectious diseases. Usually, designs based on elite dairy sires are used in association studies, but an epidemiological case-control strategy, based on cows repeatedly field-tested could be an alternative for disease traits. To test this hypothesis, genetic association results obtained in the present work from a cohort of Italian Holstein cows tested for mastitis over time were compared with those from a previous genome-wide scan on Italian Holstein sires genotyped with 50k single nucleotide polymorphisms for de-regressed estimated breeding values for somatic cell counts (SCCs) on Bos taurus autosome (BTA6) and BTA14. A total of 1121 cows were selected for the case-control approach (cases=550, controls=571), on a combination of herd level of SCC incidence and of within herd individual level of SCC. The association study was conducted on nine previously identified markers, six on BTA6 and four on BTA14, using the R statistical environment with the 'qtscore' function of the GenABEL package, on high/low adjusted linear score as a binomial trait. The results obtained in the cow cohort selected on epidemiological information were in agreement with those obtained from the previous sire genome-wide association study (GWAS). Six out of the nine markers showed significant association, four on BTA14 (rs109146371, rs109234250, rs109421300, rs109162116) and two on BTA6 (rs110527224 and rs42766480). Most importantly, using mastitis as a case study, the current work further validated the alternative use of historical field disease data in case-control designs for genetic analysis of infectious diseases in livestock.

Prototype Interoperability Document between NASA-JSC and DLR-GSOC Describing the CCSDS SM and C Mission Operations Prototype

NASA Technical Reports Server (NTRS)

Lucord, Steve A.; Gully, Sylvain

2009-01-01

The purpose of the PROTOTYPE INTEROPERABILITY DOCUMENT is to document the design and interfaces for the service providers and consumers of a Mission Operations prototype between JSC-OTF and DLR-GSOC. The primary goal is to test the interoperability sections of the CCSDS Spacecraft Monitor & Control (SM&C) Mission Operations (MO) specifications between both control centers. An additional goal is to provide feedback to the Spacecraft Monitor and Control (SM&C) working group through the Review Item Disposition (RID) process. This Prototype is considered a proof of concept and should increase the knowledge base of the CCSDS SM&C Mission Operations standards. No operational capabilities will be provided. The CCSDS Mission Operations (MO) initiative was previously called Spacecraft Monitor and Control (SM&C). The specifications have been renamed to better reflect the scope and overall objectives. The working group retains the name Spacecraft Monitor and Control working group and is under the Mission Operations and Information Services Area (MOIMS) of CCSDS. This document will refer to the specifications as SM&C Mission Operations, Mission Operations or just MO.

Post-encoding control of working memory enhances processing of relevant information in rhesus monkeys (Macaca mulatta).

PubMed

Brady, Ryan J; Hampton, Robert R

2018-06-01

Working memory is a system by which a limited amount of information can be kept available for processing after the cessation of sensory input. Because working memory resources are limited, it is adaptive to focus processing on the most relevant information. We used a retro-cue paradigm to determine the extent to which monkey working memory possesses control mechanisms that focus processing on the most relevant representations. Monkeys saw a sample array of images, and shortly after the array disappeared, they were visually cued to a location that had been occupied by one of the sample images. The cue indicated which image should be remembered for the upcoming recognition test. By determining whether the monkeys were more accurate and quicker to respond to cued images compared to un-cued images, we tested the hypothesis that monkey working memory focuses processing on relevant information. We found a memory benefit for the cued image in terms of accuracy and retrieval speed with a memory load of two images. With a memory load of three images, we found a benefit in retrieval speed but only after shortening the onset latency of the retro-cue. Our results demonstrate previously unknown flexibility in the cognitive control of memory in monkeys, suggesting that control mechanisms in working memory likely evolved in a common ancestor of humans and monkeys more than 32 million years ago. Future work should be aimed at understanding the interaction between memory load and the ability to control memory resources, and the role of working memory control in generating differences in cognitive capacity among primates. Copyright © 2018 Elsevier B.V. All rights reserved.

Work-related stress is associated with impaired neuropsychological test performance: a clinical cross-sectional study.

PubMed

Eskildsen, Anita; Andersen, Lars Peter; Pedersen, Anders Degn; Vandborg, Sanne Kjær; Andersen, Johan Hviid

2015-01-01

Patients on sick leave due to work-related stress often complain about impaired concentration and memory. However, it is undetermined how widespread these impairments are, and which cognitive domains are most long-term stress sensitive. Previous studies show inconsistent results and are difficult to synthesize. The primary aim of this study was to examine whether patients with work-related stress complaints have cognitive impairments compared to a matched control group without stress. Our secondary aim was to examine whether the level of self-reported perceived stress is associated with neuropsychological test performance. We used a broad neuropsychological test battery to assess 59 outpatients with work-related stress complaints (without major depression) and 59 healthy controls. We matched the patients and controls pairwise by sex, age and educational level. Compared to controls, patients generally showed mildly reduced performance across all the measured domains of the neuropsychological test battery. However, only three comparisons reached statistical significance (p < 0.05). Effect sizes (Cohen's d) were generally small to medium. The most pronounced differences between patients and controls were seen on tests of prospective memory, speed and complex working memory. There were no statistical significant associations between self-reported perceived stress level and neuropsychological test performance. In conclusion, we recommend that cognitive functions should be considered when evaluating patients with work-related stress complaints, especially when given advice regarding return to work. Since this study had a cross-sectional design, it is still uncertain whether the impairments are permanent. Further study is required to establish causal links between work-related stress and cognitive deficits.

Synthesis and Structure Property Studies of Toughened Epoxy Resins via Functionalized Polysiloxanes. Friction and Wear Studies.

DTIC Science & Technology

1987-03-30

TFP) siloxane and of ATBN and CTBN rubber modified epoxies were previously reported,,[1]. There was no significant evidence that the low surface energy...siloxane- modified epoxies reduced friction compared with the unmodified epoxy or the ATBN and CTBN modified epoxies. The reduction in wear noted for...is for the control, but their elastic moduli are lower. The CTBN samples from the previous work also had higher wear rates at the 5 percent level. It

Dissociating Interference-Control Processes between Memory and Response

ERIC Educational Resources Information Center

Bissett, Patrick G.; Nee, Derek Evan; Jonides, John

2009-01-01

The ability to mitigate interference is of central importance to cognition. Previous research has provided conflicting accounts about whether operations that resolve interference are singular in character or form a family of functions. Here, the authors examined the relationship between interference-resolution processes acting on working memory…

Synthesis of Optimal Constant-Gain Positive-Real Controllers for Passive Systems

NASA Technical Reports Server (NTRS)

Mao, Y.; Kelkar, A. G.; Joshi, S. M.

1999-01-01

This paper presents synthesis methods for the design of constant-gain positive real controllers for passive systems. The results presented in this paper, in conjunction with the previous work by the authors on passification of non-passive systems, offer a useful synthesis tool for the design of passivity-based robust controllers for non-passive systems as well. Two synthesis approaches are given for minimizing an LQ-type performance index, resulting in optimal controller gains. Two separate algorithms, one for each of these approaches, are given. The synthesis techniques are demonstrated using two numerical examples: control of a flexible structure and longitudinal control of a fighter aircraft.

Spatial working memory function in twins with schizophrenia and bipolar disorder.

PubMed

Pirkola, Tiia; Tuulio-Henriksson, Annamari; Glahn, David; Kieseppä, Tuula; Haukka, Jari; Kaprio, Jaakko; Lönnqvist, Jouko; Cannon, Tyrone D

2005-12-15

Family studies are in conflict as to whether schizophrenia and bipolar disorder have independent genetic etiologies. Given the relatively low prevalence (approximately 1%) of these disorders, the use of quantitative endophenotypic markers of genetic liability might provide a more sensitive strategy for evaluating their genetic overlap. We have previously demonstrated that spatial working memory deficits increase in a dose-dependent fashion with increasing genetic proximity to a proband among the unaffected co-twins of schizophrenic patients. Here, we evaluated whether such deficits might also mark genetic susceptibility to bipolar disorder. The Wechsler Memory Scale-Revised Visual Memory Span and Digit Span subtests were administered to 46 schizophrenic patients, 32 of their unaffected co-twins, 22 bipolar patients, 16 of their unaffected co-twins, and 100 control twins, representing unselectively nationwide twin samples. Schizophrenic patients and their unaffected co-twins performed significantly worse than control subjects on the spatial working memory task, whereas only the schizophrenic patients performed significantly below the control subjects on the verbal working memory task. Neither bipolar patients nor their unaffected co-twins differed from control subjects on these measures. Our findings support the hypothesis that impairment in spatial working memory might effectively reflect an expression of genetic liability to schizophrenia but less clearly to bipolar disorder.

[Variables related to the emergence of differential patterns in work motivation].

PubMed

Arrieta, Carlos; Navarro, José; Vicente, Susana

2008-11-01

Several longitudinal studies have shown that motivation at work acts chaotically. In very few cases, it may be linear or random. However, the factors that might explain why these different patterns emerge have not been analysed to date. In this exploratory study, we interviewed 73 employees whose motivational patterns were previously known. The results revealed that chaotic patterns were associated with high levels of motivation, self-efficacy beliefs, and perceptions of instrumentality, and also with intrinsic personal goal orientation and a perception of high work control. Linear patterns were associated with extrinsic goals and a perception of work as difficult, and random patterns were linked to high flexibility at work.

Memorable Messages as Guides to Self-Assessment of Behavior: The Role of Instrumental Values.

ERIC Educational Resources Information Center

Smith, Sandi W.; Ellis, Jennifer Butler; Yoo, Hyo-Jin

2001-01-01

Uses control theory to predict how important instrumental values and internalized memorable messages work together when undergraduate students self-assess their previous behavior. Finds none of the four higher-order value factors predicted the hypothesized relationships among values, messages, and behaviors; but the value of…

Speciation modeling of ammonia and other major solutes in anaerobic digesters

USDA-ARS?s Scientific Manuscript database

Anaerobic digestion of high-nitrogen wastes can be inhibited by high concentrations of un-ionized ammonia, NH**3 (aq). Understanding the toxicity of NH**3 (aq) to anaerobic digestion requires an understanding of the mechanisms controlling its concentration. Previous work on ammonia toxicity in an...

A test of measured dosages for chemical control of Allegheny hardwoods

Treesearch

A. F. Hough; H. J. Huntzinger

1958-01-01

Previous work by Bramble et al , Suggitt, Trevett, and Worley et a1 has shown that high spray volumes are more effective than low volumes in the basal bark treatment of woody plants with herbicides such as 2,4,5-T in kerosene or other oils.

Development and application of an observation-based light attenuation equation for northern Gulf of Mexico

EPA Science Inventory

Solar radiation is one of the main factors controlling the rate of primary production on the Louisiana Shelf in the northern Gulf of Mexico. This work seeks to improve on previously published empirical equations through the use of statistical data transformation and the incorpora...

Parkinson's Disease and Dopaminergic Therapy--Differential Effects on Movement, Reward and Cognition

ERIC Educational Resources Information Center

Rowe, J. B.; Hughes, L.; Ghosh, B. C. P.; Eckstein, D.; Williams-Gray, C. H.; Fallon, S.; Barker, R. A.; Owen, A. M.

2008-01-01

Cognitive deficits are very common in Parkinson's disease particularly for "executive functions" associated with frontal cortico-striatal networks. Previous work has identified deficits in tasks that require attentional control like task-switching, and reward-based tasks like gambling or reversal learning. However, there is a complex…

Using Computer Simulations in Chemistry Problem Solving

ERIC Educational Resources Information Center

Avramiotis, Spyridon; Tsaparlis, Georgios

2013-01-01

This study is concerned with the effects of computer simulations of two novel chemistry problems on the problem solving ability of students. A control-experimental group, equalized by pair groups (n[subscript Exp] = n[subscript Ctrl] = 78), research design was used. The students had no previous experience of chemical practical work. Student…

PREPARATION AND EVALUATION OF MODIFIED LIME AND SILICA-LIME SORBENTS FOR MERCURY VAPOR EMISSIONS CONTROL

EPA Science Inventory

The paper discusses current efforts to improve the uptake of mercury species by increasing active sites and adding oxidative species to the sorbent. (NOTE: Previous work showed that mercury chloride vapor is readily absorbed by calcium-based sorbents as an acid gas in environmen...

ENVIRONMENTAL VARIABLES CONTROLLING NITRIC OXIDE EMISSIONS FROM AGRICULTURAL SOILS IN THE SOUTHEAST UNITED STATES

EPA Science Inventory

Fluxes of nitric oxide (NO) were measured during the summer of 1994 (12 July to 11 August) in the Upper Coastal Plain of North Carolina in a continuing effort to characterize NO emissions from intensively managed agricultural soils in the southeastern United States. Previous work...

Problem Solving Under Time-Constraints.

ERIC Educational Resources Information Center

Richardson, Michael; Hunt, Earl

A model of how automated and controlled processing can be mixed in computer simulations of problem solving is proposed. It is based on previous work by Hunt and Lansman (1983), who developed a model of problem solving that could reproduce the data obtained with several attention and performance paradigms, extending production-system notation to…

Recent Progress in the Remote Detection of Vapours and Gaseous Pollutants.

ERIC Educational Resources Information Center

Moffat, A. J.; And Others

Work has been continuing on the correlation spectrometry techniques described at previous remote sensing symposiums. Advances in the techniques are described which enable accurate quantitative measurements of diffused atmospheric gases to be made using controlled light sources, accurate quantitative measurements of gas clouds relative to…

Meditation awareness training for the treatment of workaholism: A controlled trial

PubMed Central

Van Gordon, William; Shonin, Edo; Dunn, Thomas J.; Garcia-Campayo, Javier; Demarzo, Marcelo M. P.; Griffiths, Mark D.

2017-01-01

Background and aims Workaholism is a form of behavioral addiction that can lead to reduced life and job satisfaction, anxiety, depression, burnout, work–family conflict, and impaired productivity. Given the number of people affected, there is a need for more targeted workaholism treatments. Findings from previous case studies successfully utilizing second-generation mindfulness-based interventions (SG-MBIs) for treating behavioral addiction suggest that SG-MBIs may be suitable for treating workaholism. This study conducted a controlled trial to investigate the effects of an SG-MBI known as meditation awareness training (MAT) on workaholism. Methods Male and female adults suffering from workaholism (n = 73) were allocated to MAT or a waiting-list control group. Assessments were performed at pre-, post-, and 3-month follow-up phases. Results MAT participants demonstrated significant and sustained improvements over control-group participants in workaholism symptomatology, job satisfaction, work engagement, work duration, and psychological distress. Furthermore, compared to the control group, MAT participants demonstrated a significant reduction in hours spent working but without a decline in job performance. Discussion and conclusions MAT may be a suitable intervention for treating workaholism. Further controlled intervention studies investigating the effects of SG-MBIs on workaholism are warranted. PMID:28425778

The health consequences of maquiladora work: women on the US-Mexican border.

PubMed Central

Guendelman, S; Silberg, M J

1993-01-01

OBJECTIVES. As more US companies take jobs to Mexico, complaints are growing that the assembly plants (maquiladoras) exert adverse effects on workers' health. This study assessed the health of female electronic and garment maquiladora workers, comparing them with women employed in services and non-wage earners. METHODS. A survey was administered to 480 women living in Tijuana in 1990. The sample was stratified by occupation and length of employment. Functional impediments, nervousness, depression, and sense of control were used as outcome variables, controlling for other confounders. RESULTS. Despite working longer hours, receiving lower wages, and having less decision latitude and education, maquiladora workers were not worse off than service workers. Maquiladora workers reported similar incidences of depression and lack of control over life. Electronics workers, especially, had lower incidences of nervousness and functional impediments, after controlling for other confounders. Also, maquiladora work did not add an extra health burden compared with non-wage earners. CONCLUSIONS. The adverse effects of maquiladoras previously reported may have been exaggerated. Subjective factors, including negative attitudes toward economic adversity and work dissatisfaction, were stronger predictors of health than were objective indicators. PMID:8417604

Learning to Control Actions: Transfer Effects following a Procedural Cognitive Control Computerized Training

PubMed Central

Shahar, Nitzan; Meiran, Nachshon

2015-01-01

Few studies have addressed action control training. In the current study, participants were trained over 19 days in an adaptive training task that demanded constant switching, maintenance and updating of novel action rules. Participants completed an executive functions battery before and after training that estimated processing speed, working memory updating, set-shifting, response inhibition and fluid intelligence. Participants in the training group showed greater improvement than a no-contact control group in processing speed, indicated by reduced reaction times in speeded classification tasks. No other systematic group differences were found across the different pre-post measurements. Ex-Gaussian fitting of the reaction-time distribution revealed that the reaction time reduction observed among trained participants was restricted to the right tail of the distribution, previously shown to be related to working memory. Furthermore, training effects were only found in classification tasks that required participants to maintain novel stimulus-response rules in mind, supporting the notion that the training improved working memory abilities. Training benefits were maintained in a 10-month follow-up, indicating relatively long-lasting effects. The authors conclude that training improved action-related working memory abilities. PMID:25799443

Replication of a Prospective Randomized Controlled Trial of Resource Facilitation to Improve Return to Work and School After Brain Injury.

PubMed

Trexler, Lance E; Parrott, Devan R; Malec, James F

2016-02-01

To determine the extent to which previous findings on the effectiveness of resource facilitation to impact return to work and school could be replicated. Randomized controlled trial. Outpatient rehabilitation clinic. Outpatients with acquired brain injury (N=44). Fifteen months of resource facilitation services. A revised version of the Vocational Independence Scale and the Mayo-Portland Adaptability Inventory-4 Participation Index. Participants randomized to the resource facilitation group demonstrated a significant advantage in terms of rate and timing of return to productive community-based work relative to control participants. When examining only return to competitive work (and not return to school), 69% of the resource facilitation group was able to return compared with 50% of the control participants. Analyses of measures of participation in household and community activities revealed that both groups improved significantly over the 15-month study period, but no significant advantage for either group was demonstrated. This study replicates the positive impact of resource facilitation in improving productive community-based activity, including competitive employment and volunteering in the community. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Restoring Proprioception via a Cortical Prosthesis: A Novel Learning Based Approach

DTIC Science & Technology

2016-10-01

microstimulation from the neural recordings used for BMI control. This allows us to move to a much more efficient paradigm with continuous brain “ read out” for...microstimulation; movement control 3. ACCOMPLISHMENTS: What were the major goals of the project? Specific Aim 1: Determine whether animals ... animals . However, that signal will correlate on a millisecond timescale with visual feedback of the virtual limb. Based on the previous work (Dadarlat

Once-per-step control of ankle-foot prosthesis push-off work reduces effort associated with balance during walking.

PubMed

Kim, Myunghee; Collins, Steven H

2015-05-01

Individuals with below-knee amputation have more difficulty balancing during walking, yet few studies have explored balance enhancement through active prosthesis control. We previously used a dynamical model to show that prosthetic ankle push-off work affects both sagittal and frontal plane dynamics, and that appropriate step-by-step control of push-off work can improve stability. We hypothesized that this approach could be applied to a robotic prosthesis to partially fulfill the active balance requirements of human walking, thereby reducing balance-related activity and associated effort for the person using the device. We conducted experiments on human participants (N = 10) with simulated amputation. Prosthetic ankle push-off work was varied on each step in ways expected to either stabilize, destabilize or have no effect on balance. Average ankle push-off work, known to affect effort, was kept constant across conditions. Stabilizing controllers commanded more push-off work on steps when the mediolateral velocity of the center of mass was lower than usual at the moment of contralateral heel strike. Destabilizing controllers enforced the opposite relationship, while a neutral controller maintained constant push-off work regardless of body state. A random disturbance to landing foot angle and a cognitive distraction task were applied, further challenging participants' balance. We measured metabolic rate, foot placement kinematics, center of pressure kinematics, distraction task performance, and user preference in each condition. We expected the stabilizing controller to reduce active control of balance and balance-related effort for the user, improving user preference. The best stabilizing controller lowered metabolic rate by 5.5% (p = 0.003) and 8.5% (p = 0.02), and step width variability by 10.0% (p = 0.009) and 10.7% (p = 0.03) compared to conditions with no control and destabilizing control, respectively. Participants tended to prefer stabilizing controllers. These effects were not due to differences in average push-off work, which was unchanged across conditions, or to average gait mechanics, which were also unchanged. Instead, benefits were derived from step-by-step adjustments to prosthesis behavior in response to variations in mediolateral velocity at heel strike. Once-per-step control of prosthetic ankle push-off work can reduce both active control of foot placement and balance-related metabolic energy use during walking.

Occupational Exposures and Chronic Kidney Disease: Possible associations with endotoxin and ultrafine particles

PubMed Central

Sponholtz, Todd R.; Sandler, Dale P.; Parks, Christine G.; Applebaum, Katie M.

2015-01-01

Background Chronic kidney disease (CKD) carries a high public health burden yet there is limited research on occupational factors, which are examined in this retrospective case-control study. Methods Newly diagnosed cases of CKD (n=547) and controls (n=508) from North Carolina provided detailed work histories in telephone interviews. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results There was heterogeneity in the association of CKD and agricultural work, with crop production associated with increased risk and work with livestock associated with decreased risk. Work with cutting/cooling/lubricating oils was associated with a reduced risk. CKD risk was increased for working in dusty conditions. Conclusions CKD risk was reduced in subjects with occupational exposures previously reported to involve endotoxin exposure. Further, exposure to dusty conditions was consistently associated with increased risk of glomerulonephritis across industry, suggesting that research on CKD and ultrafine particulates is needed. PMID:26572099

Occupational exposures and chronic kidney disease: Possible associations with endotoxin and ultrafine particles.

PubMed

Sponholtz, Todd R; Sandler, Dale P; Parks, Christine G; Applebaum, Katie M

2016-01-01

Chronic kidney disease (CKD) carries a high public health burden yet there is limited research on occupational factors, which are examined in this retrospective case-control study. Newly diagnosed cases of CKD (n = 547) and controls (n = 508) from North Carolina provided detailed work histories in telephone interviews. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). There was heterogeneity in the association of CKD and agricultural work, with crop production associated with increased risk and work with livestock associated with decreased risk. Work with cutting/cooling/lubricating oils was associated with a reduced risk. CKD risk was increased for working in dusty conditions. CKD risk was reduced in subjects with occupational exposures previously reported to involve endotoxin exposure. Further, exposure to dusty conditions was consistently associated with increased risk of glomerulonephritis across industry, suggesting that research on CKD and ultrafine particulates is needed. © 2015 Wiley Periodicals, Inc.

A locus coeruleus-norepinephrine account of individual differences in working memory capacity and attention control.

PubMed

Unsworth, Nash; Robison, Matthew K

2017-08-01

Studies examining individual differences in working memory capacity (WMC) have suggested that low WMC individuals have particular deficits in attention control processes compared to high WMC individuals. In the current article we suggest that part of the WMC-attention control relation is due to variation in the functioning of the locus coeruleus-norepinephrine system (LC-NE). Specifically, we suggest that because of dysregulation of LC-NE functioning, the fronto-parietal control network for low WMC individuals is only weakly activated, resulting in greater default-mode network activity (and greater mind-wandering) for low WMC individuals compared to high WMC individuals. This results in disrupted attention control and overall more erratic performance (more lapses of attention) for low WMC individuals than for high WMC individuals. This framework is used to examine previous studies of individual differences in WMC and attention control, and new evidence is examined on the basis of predictions of the framework to pupillary responses as an indirect marker of LC-NE functioning.

The irrelevant speech effect and working memory load.

PubMed

Gisselgård, Jens; Petersson, Karl Magnus; Ingvar, Martin

2004-07-01

Irrelevant speech impairs the immediate serial recall of visually presented material. Previously, we have shown that the irrelevant speech effect (ISE) was associated with a relative decrease of regional blood flow in cortical regions subserving the verbal working memory, in particular the superior temporal cortex. In this extension of the previous study, the working memory load was increased and an increased activity as a response to irrelevant speech was noted in the dorsolateral prefrontal cortex. We suggest that the two studies together provide some basic insights as to the nature of the irrelevant speech effect. Firstly, no area in the brain can be ascribed as the single locus of the irrelevant speech effect. Instead, the functional neuroanatomical substrate to the effect can be characterized in terms of changes in networks of functionally interrelated areas. Secondly, the areas that are sensitive to the irrelevant speech effect are also generically activated by the verbal working memory task itself. Finally, the impact of irrelevant speech and related brain activity depends on working memory load as indicated by the differences between the present and the previous study. From a brain perspective, the irrelevant speech effect may represent a complex phenomenon that is a composite of several underlying mechanisms, which depending on the working memory load, include top-down inhibition as well as recruitment of compensatory support and control processes. We suggest that, in the low-load condition, a selection process by an inhibitory top-down modulation is sufficient, whereas in the high-load condition, at or above working memory span, auxiliary adaptive cognitive resources are recruited as compensation. Copyright 2004 Elsevier Inc.

The long-term mortality impact of combined job strain and family circumstances: A life course analysis of working American mothers.

PubMed

Sabbath, Erika L; Mejía-Guevara, Iván; Noelke, Clemens; Berkman, Lisa F

2015-12-01

Work stress and family composition have been separately linked with later-life mortality among working women, but it is not known how combinations of these exposures impact mortality, particularly when exposure is assessed cumulatively over the life course. We tested whether, among US women, lifelong work stress and lifelong family circumstances would jointly predict mortality risk. We studied formerly working mothers in the US Health and Retirement Study (HRS) born 1924-1957 (n = 7352). We used sequence analysis to determine five prototypical trajectories of marriage and parenthood in our sample. Using detailed information on occupation and industry of each woman's longest-held job, we assigned each respondent a score for job control and job demands. We calculated age-standardized mortality rates by combined job demands, job control, and family status, then modeled hazard ratios for death based on family constellation, job control tertiles, and their combination. Married women who had children later in life had the lowest mortality risks (93/1000). The highest-risk family clusters were characterized by spells of single motherhood (132/1000). Generally, we observed linear relationships between job control and mortality hazard within each family trajectory. But while mortality risk was high for all long-term single mothers, we did not observe a job control-mortality gradient in this group. The highest-mortality subgroup was previously married women who became single mothers later in life and had low job control (HR 1.91, 95% CI 1.38,2.63). Studies of associations between psychosocial work characteristics and health might consider heterogeneity of effects by family circumstances. Worksite interventions simultaneously considering both work and family characteristics may be most effective in reducing health risks. Copyright © 2015 Elsevier Ltd. All rights reserved.

The long-term mortality impact of combined job strain and family circumstances: A life course analysis of working American mothers

PubMed Central

Sabbath, Erika L.; Mejía-Guevara, Iván; Noelke, Clemens; Berkman, Lisa F.

2015-01-01

Background Work stress and family composition have been separately linked to later-life mortality among working women, but it is not known how combinations of these exposures impact mortality, particularly when exposure is assessed cumulatively over the life course. We tested whether, among US women, lifelong work stress and lifelong family circumstances would jointly predict mortality risk. Procedures We studied formerly working mothers in the US Health and Retirement Study (HRS) born 1924-1957 (n=7,352). We used sequence analysis to determine five prototypical trajectories of marriage and parenthood in our sample. Using detailed information on occupation and industry of each woman’s longest-held job, we assigned each respondent a score for job control and job demands. We calculated age-standardized mortality rates by combined job demands, job control, and family status, then modeled hazard ratios for death based on family constellation, job control tertiles, and their combination. Results Married women who had children later in life had the lowest mortality risks (93/1,000). The highest-risk family clusters were characterized by spells of single motherhood (132/1,000). Generally, we observed linear relationships between job control and mortality hazard within each family trajectory. But while mortality risk was high for all long-term single mothers, we did not observe a job control-mortality gradient in this group. The highest-mortality subgroup was previously married women who became single mothers later in life and had low job control (HR 1.91, 95% CI 1.38,2.63). Practical implications Studies of associations between psychosocial work characteristics and health might consider heterogeneity of effects by family circumstances. Worksite interventions simultaneously considering both work and family characteristics may be most effective in reducing health risks. PMID:26513120

Mindfulness Meditation Training and Executive Control Network Resting State Functional Connectivity: A Randomized Controlled Trial.

PubMed

Taren, Adrienne A; Gianaros, Peter J; Greco, Carol M; Lindsay, Emily K; Fairgrieve, April; Brown, Kirk Warren; Rosen, Rhonda K; Ferris, Jennifer L; Julson, Erica; Marsland, Anna L; Creswell, J David

Mindfulness meditation training has been previously shown to enhance behavioral measures of executive control (e.g., attention, working memory, cognitive control), but the neural mechanisms underlying these improvements are largely unknown. Here, we test whether mindfulness training interventions foster executive control by strengthening functional connections between dorsolateral prefrontal cortex (dlPFC)-a hub of the executive control network-and frontoparietal regions that coordinate executive function. Thirty-five adults with elevated levels of psychological distress participated in a 3-day randomized controlled trial of intensive mindfulness meditation or relaxation training. Participants completed a resting state functional magnetic resonance imaging scan before and after the intervention. We tested whether mindfulness meditation training increased resting state functional connectivity (rsFC) between dlPFC and frontoparietal control network regions. Left dlPFC showed increased connectivity to the right inferior frontal gyrus (T = 3.74), right middle frontal gyrus (MFG) (T = 3.98), right supplementary eye field (T = 4.29), right parietal cortex (T = 4.44), and left middle temporal gyrus (T = 3.97, all p < .05) after mindfulness training relative to the relaxation control. Right dlPFC showed increased connectivity to right MFG (T = 4.97, p < .05). We report that mindfulness training increases rsFC between dlPFC and dorsal network (superior parietal lobule, supplementary eye field, MFG) and ventral network (right IFG, middle temporal/angular gyrus) regions. These findings extend previous work showing increased functional connectivity among brain regions associated with executive function during active meditation by identifying specific neural circuits in which rsFC is enhanced by a mindfulness intervention in individuals with high levels of psychological distress. Clinicaltrials.gov,NCT01628809.

Taboo: Working memory and mental control in an interactive task

PubMed Central

Hansen, Whitney A.; Goldinger, Stephen D.

2014-01-01

Individual differences in working memory (WM) predict principled variation in tasks of reasoning, response time, memory, and other abilities. Theoretically, a central function of WM is keeping task-relevant information easily accessible while suppressing irrelevant information. The present experiment was a novel study of mental control, using performance in the game Taboo as a measure. We tested effects of WM capacity on several indices, including perseveration errors (repeating previous guesses or clues) and taboo errors (saying at least part of a taboo or target word). By most measures, high-span participants were superior to low-span participants: High-spans were better at guessing answers, better at encouraging correct guesses from teammates, and less likely to either repeat themselves or produce taboo clues. Differences in taboo errors occurred only in an easy control condition. The results suggest that WM capacity predicts behavior in tasks requiring mental control, extending this finding to an interactive group setting. PMID:19827699

Control theory based airfoil design using the Euler equations

NASA Technical Reports Server (NTRS)

Jameson, Antony; Reuther, James

1994-01-01

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In our previous work it was shown that control theory could be employed to devise effective optimization procedures for two-dimensional profiles by using the potential flow equation with either a conformal mapping or a general coordinate system. The goal of our present work is to extend the development to treat the Euler equations in two-dimensions by procedures that can readily be generalized to treat complex shapes in three-dimensions. Therefore, we have developed methods which can address airfoil design through either an analytic mapping or an arbitrary grid perturbation method applied to a finite volume discretization of the Euler equations. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented for both the inverse problem and drag minimization problem.

Adaptive Working Memory Training Reduces the Negative Impact of Anxiety on Competitive Motor Performance.

PubMed

Ducrocq, Emmanuel; Wilson, Mark; Smith, Tim J; Derakshan, Nazanin

2017-12-01

Optimum levels of attentional control are essential to prevent athletes from experiencing performance breakdowns under pressure. The current study explored whether training attentional control using the adaptive dual n-back paradigm, designed to directly target processing efficiency of the main executive functions of working memory (WM), would result in transferrable effects on sports performance outcomes. A total of 30 tennis players were allocated to an adaptive WM training or active control group and underwent 10 days of training. Measures of WM capacity as well as performance and objective gaze indices of attentional control in a tennis volley task were assessed in low- and high-pressure posttraining conditions. Results revealed significant benefits of training on WM capacity, quiet eye offset, and tennis performance in the high-pressure condition. Our results confirm and extend previous findings supporting the transfer of cognitive training benefits to objective measures of sports performance under pressure.

Risk factors for first trimester miscarriage--results from a UK-population-based case-control study.

PubMed

Maconochie, N; Doyle, P; Prior, S; Simmons, R

2007-02-01

The aim of this study was to examine the association between biological, behavioural and lifestyle risk factors and risk of miscarriage. Population-based case-control study. Case-control study nested within a population-based, two-stage postal survey of reproductive histories of women randomly sampled from the UK electoral register. Six hundred and three women aged 18-55 years whose most recent pregnancy had ended in first trimester miscarriage (<13 weeks of gestation; cases) and 6116 women aged 18-55 years whose most recent pregnancy had progressed beyond 12 weeks (controls). Women were questioned about socio-demographic, behavioural and other factors in their most recent pregnancy. First trimester miscarriage. After adjustment for confounding, the following were independently associated with increased risk: high maternal age; previous miscarriage, termination and infertility; assisted conception; low pre-pregnancy body mass index; regular or high alcohol consumption; feeling stressed (including trend with number of stressful or traumatic events); high paternal age and changing partner. Previous live birth, nausea, vitamin supplementation and eating fresh fruits and vegetables daily were associated with reduced risk, as were feeling well enough to fly or to have sex. After adjustment for nausea, we did not confirm an association with caffeine consumption, smoking or moderate or occasional alcohol consumption; nor did we find an association with educational level, socio-economic circumstances or working during pregnancy. The results confirm that advice to encourage a healthy diet, reduce stress and promote emotional wellbeing might help women in early pregnancy (or planning a pregnancy) reduce their risk of miscarriage. Findings of increased risk associated with previous termination, stress, change of partner and low pre-pregnancy weight are noteworthy, and we recommend further work to confirm these findings in other study populations.

Recent Developments on Microencapsulation for Autonomous Corrosion Protection

NASA Technical Reports Server (NTRS)

Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Fitzpatrick, Lilliana; Jolley, Scott T.; Surma, Jan M.; Pearman, Benjamin P.; Zhang, Xuejun

2014-01-01

This work concerns recent progress in the development of a multifunctional smart coating based on microencapsulation for the autonomous control of corrosion. Microencapsulation allows the incorporation of desired corrosion control functionalities, such as early corrosion detection and inhibition through corrosion controlled release of corrosion indicators and inhibitors, as well as self-healing agent release when mechanical damage occurs.While proof-of-concept results have been reported previously, more recent efforts have been concentrated in technical developments to improve coating compatibility, synthesis procedure scalability, as well as fine tuning the release property of encapsulated active agents.

International Space Station Environmental Control and Life Support System Previous Year Status for 2013 - 2014

NASA Technical Reports Server (NTRS)

Williams, David E.; Gentry, Gregory J.

2015-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year and the impacts of the international partners' activities on them, covering the period of time between March 2013 and February 2014. The ISS continued permanent crew operations including the continuation of six crew members being on ISS. Work continues on the commercial crew vehicles, and work to try and extend ISS service life.

Reading Comprehension in Children with ADHD: Cognitive Underpinnings of the Centrality Deficit

PubMed Central

Miller, Amanda C.; Keenan, Janice M.; Betjemann, Rebecca S.; Willcutt, Erik; Pennington, Bruce F.; Olson, Richard K.

2012-01-01

We examined reading comprehension in children with ADHD by assessing their ability to build a coherent mental representation that allows them to recall central and peripheral information. We compared children with ADHD (mean age 9.78) to word reading-matched controls (mean age 9.89) on their ability to retell a passage. We found that even though children with ADHD recalled more central than peripheral information, they showed their greatest deficit, relative to controls, on central information – a centrality deficit (Miller & Keenan, 2009). We explored the cognitive underpinnings of this deficit using regressions to compare how well cognitive factors (working memory, inhibition, processing speed, and IQ) predicted the ability to recall central information, after controlling for word reading ability, and whether these cognitive factors interacted with ADHD symptoms. Working memory accounted for the most unique variance. Although previous evidence for reading comprehension difficulties in children with ADHD have been mixed, this study suggests that even when word reading ability is controlled, children with ADHD have difficulty building a coherent mental representation, and this difficulty is likely related to deficits in working memory. PMID:23054132

Combining dispositions and evaluations of vocation and job to account for counterproductive work behavior in adolescent job apprentices.

PubMed

Marcus, Bernd; Wagner, Uwe

2007-04-01

In the present research, we investigated the joint impact of selected antecedents of counterproductive work behavior (CWB). A sample of German apprentices reported on their CWB and completed measures of situational evaluations (vocational preference, level and constructiveness of job satisfaction) believed to trigger CWB and of dispositional motivators (measured by integrity test subscales) and controls (self-control and another subset of integrity scales) of CWB. All predictors investigated showed the expected bivariate relationships with CWB. Multivariate analyses revealed that the triggering effect of an unfavorable vocational choice on CWB was fully mediated by job satisfaction. When predictors were aggregated, a composite of dispositional control variables had the largest effect on CWB and moderated the effects of motivational dispositions and situational evaluations. These results extend the knowledge on antecedents of CWB by investigating previously overlooked variables and samples and partially replicate recent findings on the joint impact of dispositions and work-related evaluations on CWB. Copyright (c) 2007 APA, all rights reserved.

USP7/HAUSP: A SUMO deubiquitinase at the heart of DNA replication.

PubMed

Smits, Veronique A J; Freire, Raimundo

2016-09-01

DNA replication is both highly conserved and controlled. Problematic DNA replication can lead to genomic instability and therefore carcinogenesis. Numerous mechanisms work together to achieve this tight control and increasing evidence suggests that post-translational modifications (phosphorylation, ubiquitination, SUMOylation) of DNA replication proteins play a pivotal role in this process. Here we discuss such modifications in the light of a recent article that describes a novel role for the deubiquitinase (DUB) USP7/HAUSP in the control of DNA replication. USP7 achieves this function by an unusual and novel mechanism, namely deubiquitination of SUMOylated proteins at the replication fork, making USP7 also a SUMO DUB (SDUB). This work extends previous observations of increased levels of SUMO and low levels of ubiquitin at the on-going replication fork. Here, we discuss this novel study, its contribution to the DNA replication and genomic stability field and what questions arise from this work. © 2016 WILEY Periodicals, Inc.

A comparison of GluR-A-deficient and wild-type mice on a test battery assessing sensorimotor, affective, and cognitive behaviors.

PubMed

Bannerman, D M; Deacon, R M J; Brady, S; Bruce, A; Sprengel, R; Seeburg, P H; Rawlins, J N P

2004-06-01

Previous studies have demonstrated a spatial working memory deficit in glutamate receptor (GluR)-A (GluR1) AMPA receptor subunit knockout mice. The present study evaluated male and female wild-type and GluR-A-/- mice on a test battery that assessed sensorimotor, affective, and cognitive behaviors. Results revealed a behavioral phenotype more extensive than previously described. GluR-A-/- mice were hyperactive, displayed a subtle lack of motor coordination, and were generally more anxious than wild-type controls. In addition, they showed a deficit in spontaneous alternation, consistent with previous reports of a role for GluR-A-dependent plasticity in hippocampus-dependent, spatial working memory. Although changes in motor coordination or anxiety cannot explain the dissociations already reported within the spatial memory domain, it is clear that they could significantly affect interpretation of results obtained in other kinds of behavioral tasks. ((c) 2004 APA, all rights reserved)

Alkali activated solidification/stabilisation of air pollution control residues and co-fired pulverised fuel ash.

PubMed

Shirley, Robin; Black, Leon

2011-10-30

This paper examines the potential treatment by solidification/stabilisation (S/S) of air pollution control (APC) residues using only waste materials otherwise bound for disposal, namely a pulverised fuel ash (PFA) from a co-fired power station and a waste caustic solution. The use of waste materials to stabilise hazardous wastes in order to meet waste acceptance criteria (WAC) would offer an economical and efficient method for reducing the environmental impact of the hazardous waste. The potential is examined against leach limits for chlorides, sulphates and total dissolved solids, and compressive strength performance described in the WAC for stable non-reactive (SNR) hazardous waste landfill cells in England and Wales. The work demonstrates some potential for the treatment, including suitable compressive strengths to meet regulatory limits. Monolithic leach results showed good encapsulation compared to previous work using a more traditional cement binder. However, consistent with previous work, SNR WAC for chlorides was not met, suggesting the need for a washing stage. The potential problems of using a non-EN450 PFA for S/S applications were also highlighted, as well as experimental results which demonstrate the effect of ionic interactions on the mobility of phases during regulatory leach testing. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of a brief emergency medicine education course on emergency department work intensity of family physicians.

PubMed

Vaillancourt, Samuel; Schultz, Susan E; Leaver, Chad; Stukel, Thérèse A; Schull, Michael J

2013-01-01

Recently, many Canadian emergency departments (EDs) have struggled with physician staffing shortages. In 2006, the Ontario Ministry of Health and Long-Term Care funded a brief "emergency medicine primer" (EMP) course for family physicians to upgrade or refresh skills, with the goal of increasing their ED work intensity. We sought to determine the effect of the EMP on the ED work intensity of family physicians. A retrospective longitudinal study was conducted of the ED work of 239 family physicians in the 2 years before and after a minimum of 6 months and up to 2 years from completing an EMP course in 2006 to 2008 compared to non-EMP physicians. ED work intensity was defined as the number of ED shifts per month and the number of ED patients seen per month. We conducted two analyses: a before and after comparison of all EMP physicians and a matched cohort analysis matching each EMP physician to four non-EMP physicians on sex, year of medical school graduation, rurality, and pre-EMP ED work intensity. Postcourse, EMP physicians worked 0.5 more ED shifts per month (13% increase, p  =  0.027). Compared to their matched controls, EMP physicians worked 0.7 more shifts per month (13% increase, p  =  0.0032) and saw 15 more patients per month (17% increase, p  =  0.0008) compared to matched non-EMP physicians. The greatest increases were among EMP physicians who were younger, were urban, had previous ED experience, or worked in a high-volume ED. The effect of the EMP course was negligible for physicians with no previous ED experience or working in rural areas. The EMP course is associated with modest increases in ED work intensity among some family physicians, in particular younger physicians in urban areas. No increase was seen among physicians without previous ED experience or working in rural areas.

Sensitivity analysis as an aid in modelling and control of (poorly-defined) ecological systems. [closed ecological systems

NASA Technical Reports Server (NTRS)

Hornberger, G. M.; Rastetter, E. B.

1982-01-01

A literature review of the use of sensitivity analyses in modelling nonlinear, ill-defined systems, such as ecological interactions is presented. Discussions of previous work, and a proposed scheme for generalized sensitivity analysis applicable to ill-defined systems are included. This scheme considers classes of mathematical models, problem-defining behavior, analysis procedures (especially the use of Monte-Carlo methods), sensitivity ranking of parameters, and extension to control system design.

A Structural Characterization of Temporal Dynamic Controllability

NASA Technical Reports Server (NTRS)

Morris, Paul

2006-01-01

An important issue for temporal planners is the ability to handle temporal uncertainty. Recent papers have addressed the question of how to tell whether a temporal network is Dynamically Controllable, i.e., whether the temporal requirements are feasible in the light of uncertain durations of some processes. Previous work has presented an O(N5) algorithm for testing this property. Here, we introduce a new analysis of temporal cycles that leads to an O(N4) algorithm.

Changes in the Influence of Alcohol-Paired Stimuli on Alcohol Seeking across Extended Training

PubMed Central

Corbit, Laura H.; Janak, Patricia H.

2016-01-01

Previous work has demonstrated that goal-directed control of alcohol-seeking and other drug-related behaviors is reduced following extended self-administration and drug exposure. Here, we examined how the magnitude of stimulus influences on responding changes across similar training and drug exposure. Rats self-administered alcohol or sucrose for 2 or 8 weeks. Previous work has shown that 8 weeks, but not 2 weeks of self-administration produces habitual alcohol seeking. Next, all animals received equivalent Pavlovian conditioning sessions where a discrete stimulus predicted the delivery of alcohol or sucrose. Finally, the impact of the stimuli on ongoing instrumental responding was examined in a Pavlovian–instrumental transfer (PIT) test. While a significant PIT effect was observed following 2 weeks of either alcohol or sucrose self-administration, the magnitude of this effect was greater following 8 weeks of training. The specificity of the PIT effect appeared unchanged by extended training. While it is well established that evaluation of the outcome of responding contributes less to behavioral control following extended training and/or drug exposure, our data indicate that reward–predictive stimuli have a stronger contribution to responding after extended training. Together, these findings provide insight into the factors that control behavior after extended drug use, which will be important for developing effective methods for controlling and ideally reducing these behaviors. PMID:27777560

Relative fundamental frequency during vocal onset and offset in older speakers with and without Parkinson's disease.

PubMed

Stepp, Cara E

2013-03-01

The relative fundamental frequency (RFF) surrounding production of a voiceless consonant has previously been shown to be lower in speakers with hypokinetic dysarthria and Parkinson's disease (PD) relative to age/sex matched controls. Here RFF was calculated in 32 speakers with PD without overt hypokinetic dysarthria and 32 age and sex matched controls to better understand the relationships between RFF and PD progression, medication status, and sex. Results showed that RFF was statistically significantly lower in individuals with PD compared with healthy age-matched controls and was statistically significantly lower in individuals diagnosed at least 5 yrs prior to experimentation relative to individuals recorded less than 5 yrs past diagnosis. Contrary to previous trends, no effect of medication was found. However, a statistically significant effect of sex on offset RFF was shown, with lower values in males relative to females. Future work examining the physiological bases of RFF is warranted.

Characterizing Rule-Based Category Learning Deficits in Patients with Parkinson's Disease

ERIC Educational Resources Information Center

Filoteo, J. Vincent; Maddox, W. Todd; Ing, A. David; Song, David D.

2007-01-01

Parkinson's disease (PD) patients and normal controls were tested in three category learning experiments to determine if previously observed rule-based category learning impairments in PD patients were due to deficits in selective attention or working memory. In Experiment 1, optimal categorization required participants to base their decision on a…

Using CMAQ to provide probabilistic assessment of emission control scenarios in meeting the ozone standard

EPA Science Inventory

In the United States, regional-scale air quality models are being used to identify emissions reductions needed to comply with the ozone National Ambient Air Quality Standard. Previous work has demonstrated that ozone extreme values (i.e., 4th highest ozone or Design Value) are c...

Overview of Fiber-Optical Sensors

NASA Technical Reports Server (NTRS)

Depaula, Ramon P.; Moore, Emery L.

1987-01-01

Design, development, and sensitivity of sensors using fiber optics reviewed. State-of-the-art and probable future developments of sensors using fiber optics described in report including references to work in field. Serves to update previously published surveys. Systems incorporating fiber-optic sensors used in medical diagnosis, navigation, robotics, sonar, power industry, and industrial controls.

The Evolution, Design and Implementation of the Minds in Motion Curriculum

ERIC Educational Resources Information Center

Cottone, Elizabeth; Chen, Wei-Bing; Brock, Laura

2013-01-01

Building on the empirical work of the previous two studies, this paper describes the development of the Minds In Motion curriculum (MIM), as well as the setting and circumstances of a randomized controlled trial conducted to evaluate this intervention. Throughout this paper the authors emphasize the benefits and challenges of assembling an…

In vitro fermentation of alternansucrase raffinose acceptor products by human gut bacteria

USDA-ARS?s Scientific Manuscript database

In this work, in vitro fermentation of alternansucrase raffinose acceptor products, previously fractionated according to their degree of polymerization (DP; from DP4 to DP10) was carried out using pH-controlled small scale batch cultures at 37ºC under anaerobic conditions with human faeces. Bifidog...

Controls on interannual variation in evapotranspiration and water use efficiency in a mature, furrow-irrigated peach orchard

USDA-ARS?s Scientific Manuscript database

Evapotranspiration (ET) and water use efficiency (WUE) in peach orchards has previously been observed in young (less than 5-8 years old), drip irrigated orchards using micrometeorological techniques such as Eddy Covariance or large-weighing lysimeters. However, no work has been reported on ET and W...

Use of ATR FT-IR spectroscopy in non-destructive and rapid assessment of developmental cotton fibers

USDA-ARS?s Scientific Manuscript database

The knowledge of chemical and compositional components in cotton fibers is of value to cotton breeders and growers for cotton enhancement and to textile processors for quality control. In this work, we applied the previously proposed simple algorithms to analyze the attenuated total reflection Fouri...

Assessment of Infant Cry: Acoustic Cry Analysis and Parental Perception

ERIC Educational Resources Information Center

LaGasse, Linda L.; Neal, A. Rebecca; Lester, Barry M.

2005-01-01

Infant crying signals distress to potential caretakers who can alleviate the aversive conditions that gave rise to the cry. The cry signal results from coordination among several brain regions that control respiration and vocal cord vibration from which the cry sounds are produced. Previous work has shown a relationship between acoustic…

Predicting Word Reading and Comprehension with Executive Function and Speed Measures across Development: A Latent Variable Analysis

ERIC Educational Resources Information Center

Christopher, Micaela E.; Miyake, Akira; Keenan, Janice M.; Pennington, Bruce; DeFries, John C.; Wadsworth, Sally J.; Willcutt, Erik; Olson, Richard K.

2012-01-01

The present study explored whether different executive control and speed measures (working memory, inhibition, processing speed, and naming speed) independently predict individual differences in word reading and reading comprehension. Although previous studies suggest these cognitive constructs are important for reading, the authors analyze the…

Energy Systems Integration Newsletter - December 2016 | Energy Systems

Science.gov Websites

in New NSF Big Data Project for Smart Grids NREL is participating in a National Science Foundation control features of modern wind turbine generators. Frew presented research on wholesale market design and industry research. Previous work was cited in numerous European studies, and ERGIS was mentioned as an

The intestinal fatty acid propionate inhibits Salmonella invasion through the post-translational control of HilD

USDA-ARS?s Scientific Manuscript database

For Salmonella to cause disease, it must first invade the intestinal epithelium using genes encoded within Salmonella Pathogenicity Island 1 (SPI1). Previous work has shown that propionate, a short chain fatty acid abundant in the intestine of animal hosts, negatively regulates SPI1 in vitro. Here...

A lot of hard work, but doable: Pregnancy experiences of women with type-1 diabetes.

PubMed

McGrath, Meaghan; Chrisler, Joan C

2017-06-01

Despite many medical advances, pregnant women with type-1 diabetes are still considered to be at high risk. Previous research suggests that physicians' focus on strict glycemic control and negative outcomes can result in fear and uncertainty about undertaking pregnancy. The present study was designed to gain insight into the lived pregnancy experiences of women with type-1 diabetes and to solicit their thoughts on what health care providers could do to assist them to have a healthy pregnancy. Ten U.S. women with type-1 diabetes who were currently pregnant and/or had previously given birth participated in structured interviews. They described the hard work required to attain the strict glycemic control necessary during pregnancy to maintain their health and that of their fetus. However, they found diabetes and pregnancy to be a more positive and successful experience than they had anticipated. The results suggest that early diabetes education, pregnancy planning, and social support are important, yet often overlooked, factors that increase the likelihood of physically and emotionally successful pregnancy experiences for women with type-1 diabetes.

Bio-inspired, Moisture-Powered Hybrid Carbon Nanotube Yarn Muscles

PubMed Central

Kim, Shi Hyeong; Kwon, Cheong Hoon; Park, Karam; Mun, Tae Jin; Lepró, Xavier; Baughman, Ray H.; Spinks, Geoffrey M.; Kim, Seon Jeong

2016-01-01

Hygromorph artificial muscles are attractive as self-powered actuators driven by moisture from the ambient environment. Previously reported hygromorph muscles have been largely limited to bending or torsional motions or as tensile actuators with low work and energy densities. Herein, we developed a hybrid yarn artificial muscle with a unique coiled and wrinkled structure, which can be actuated by either changing relative humidity or contact with water. The muscle provides a large tensile stroke (up to 78%) and a high maximum gravimetric work capacity during contraction (2.17 kJ kg−1), which is over 50 times that of the same weight human muscle and 5.5 times higher than for the same weight spider silk, which is the previous record holder for a moisture driven muscle. We demonstrate an automatic ventilation system that is operated by the tensile actuation of the hybrid muscles caused by dew condensing on the hybrid yarn. This self-powered humidity-controlled ventilation system could be adapted to automatically control the desired relative humidity of an enclosed space. PMID:26973137

Postural response to predictable and nonpredictable visual flow in children and adults.

PubMed

Schmuckler, Mark A

2017-11-01

Children's (3-5years) and adults' postural reactions to different conditions of visual flow information varying in its frequency content was examined using a moving room apparatus. Both groups experienced four conditions of visual input: low-frequency (0.20Hz) visual oscillations, high-frequency (0.60Hz) oscillations, multifrequency nonpredictable visual input, and no imposed visual information. Analyses of the frequency content of anterior-posterior (AP) sway revealed that postural reactions to the single-frequency conditions replicated previous findings; children were responsive to low- and high-frequency oscillations, whereas adults were responsive to low-frequency information. Extending previous work, AP sway in response to the nonpredictable condition revealed that both groups were responsive to the different components contained in the multifrequency visual information, although adults retained their frequency selectivity to low-frequency versus high-frequency content. These findings are discussed in relation to work examining feedback versus feedforward control of posture, and the reweighting of sensory inputs for postural control, as a function of development and task context. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of risk and protective factors for work-related bite injuries to veterinary technicians certified in Minnesota.

PubMed

Nordgren, Leslie D; Gerberich, Susan G; Alexander, Bruce H; Church, Timothy R; Bender, Jeff B; Ryan, Andrew D

2014-08-15

To identify risk and protective factors for work-related bite injuries among veterinary technicians certified in Minnesota. Nested case-control study. 868 certified veterinary technicians (CVTs). A questionnaire was mailed to CVTs who previously participated in a survey regarding work-related injuries and did (cases; 301 surveys sent) or did not (controls; 567) report qualifying work-related animal bite injuries in the preceding 12 months. Descriptive statistics were summarized. Demographic and work-related variables for the month preceding the bite injury (for cases) or a randomly selected month (controls) were assessed with univariate analysis (489 CVTs) and multivariate analysis of a subset of 337 CVTs who worked in small or mixed mostly small animal facilities. Responses were received from 176 case and 313 control CVTs. For the subset of 337 CVTs, risk of bite injury was higher for those < 25 years of age (OR, 3.82; 95% confidence interval [CI], 1.84 to 7.94) than for those ≥ 35 years of age, for those who had worked < 5 years (OR, 3.24; 95% CI, 1.63 to 6.45) versus ≥ 10 years in any veterinary facility, and for those who handled ≥ 5 species/d (OR, 1.99; 95% CI, 1.06 to 3.74) versus < 3 species/d. Risk was lower for CVTs who handled < 10 versus ≥ 20 animals/d (OR, 0.23; 95% CI, 0.08 to 0.71). Several work-related factors were associated with the risk of work-related bite injury to CVTs. These findings may serve as a basis for development of intervention efforts and future research regarding work-related injuries among veterinary staff.

Dynamic Control of Plans with Temporal Uncertainty

NASA Technical Reports Server (NTRS)

Morris, Paul; Muscettola, Nicola; Vidal, Thierry

2001-01-01

Certain planning systems that deal with quantitative time constraints have used an underlying Simple Temporal Problem solver to ensure temporal consistency of plans. However, many applications involve processes of uncertain duration whose timing cannot be controlled by the execution agent. These cases require more complex notions of temporal feasibility. In previous work, various "controllability" properties such as Weak, Strong, and Dynamic Controllability have been defined. The most interesting and useful Controllability property, the Dynamic one, has ironically proved to be the most difficult to analyze. In this paper, we resolve the complexity issue for Dynamic Controllability. Unexpectedly, the problem turns out to be tractable. We also show how to efficiently execute networks whose status has been verified.

Are there high-risk groups among physicians that are more vulnerable to on-call work?

PubMed

Heponiemi, Tarja; Aalto, Anna-Mari; Pekkarinen, Laura; Siuvatti, Eeva; Elovainio, Marko

2015-05-01

Work done in the emergency departments is one stressful aspect of physicians' work. Numerous previous studies have highlighted the stressfulness of on-call work and especially of night on call. In addition, previous studies suggest that there may be individual differences in adjusting to changes in circadian rhythms and on-call work. The objective of this study was to examine whether physicians' on-call work is associated with perceived work-related stress factors and job resources and whether there are groups that are more vulnerable to on-call work according to sex, age, and specialization status. This was a cross-sectional questionnaire study among 3230 Finnish physicians (61.5% women). The analyses were conducted using analyses of covariance adjusted for sex, age, specialization status, and employment sector. Physicians with on-call duties had more time pressure and stress related to team work and patient information systems compared with those who did not have on-call duties. In addition, they had less job control opportunities and experienced organization as less fair and team climate as worse. Older physicians and specialists seemed to be especially vulnerable to on-call work regarding stress factors, whereas younger and specialist trainees seemed vulnerable to on-call work regarding job resources. Focusing on team issues and resources is important for younger physicians and trainees having on-call duties, whereas for older and specialists, attention should be focused on actual work load and time pressure. Copyright © 2015 Elsevier Inc. All rights reserved.

Examining procedural working memory processing in obsessive-compulsive disorder.

PubMed

Shahar, Nitzan; Teodorescu, Andrei R; Anholt, Gideon E; Karmon-Presser, Anat; Meiran, Nachshon

2017-07-01

Previous research has suggested that a deficit in working memory might underlie the difficulty of obsessive-compulsive disorder (OCD) patients to control their thoughts and actions. However, a recent meta-analyses found only small effect sizes for working memory deficits in OCD. Recently, a distinction has been made between declarative and procedural working memory. Working memory in OCD was tested mostly using declarative measurements. However, OCD symptoms typically concerns actions, making procedural working-memory more relevant. Here, we tested the operation of procedural working memory in OCD. Participants with OCD and healthy controls performed a battery of choice reaction tasks under high and low procedural working memory demands. Reaction-times (RT) were estimated using ex-Gaussian distribution fitting, revealing no group differences in the size of the RT distribution tail (i.e., τ parameter), known to be sensitive to procedural working memory manipulations. Group differences, unrelated to working memory manipulations, were found in the leading-edge of the RT distribution and analyzed using a two-stage evidence accumulation model. Modeling results suggested that perceptual difficulties might underlie the current group differences. In conclusion, our results suggest that procedural working-memory processing is most likely intact in OCD, and raise a novel, yet untested assumption regarding perceptual deficits in OCD. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Intensive working memory training: a single case experimental design in a patient following hypoxic brain damage.

PubMed

Hynes, S M; Fish, J; Manly, T

2014-01-01

Recent reports suggest that intensive, progressive training on working memory tasks can lead to generalized cognitive gains. A patient, following hypoxic brain damage, showed significant difficulties in working memory and time-perception. This study examined the impact and specificity of any benefits resulting from automated working memory training (AWMT) in comparison with the effects of an equivalent programme that emphasized automated novel problem-solving (APST) which served as an active control. Following initial assessment, the patient trained for 4 weeks (20 days), 20-30 minutes a day on the APST tasks before repeating key outcome measures. He then trained for an identical period on AWMT. There were no cognitive gains apparent following APST. Furthermore, there were no disproportionate gains on digit span following AWMT. AWMT was, however, associated with improvement in time-perception that had previously been resistant to rehabilitation. In line with previous reports, AWMT was also followed by gains on a measure of planning. The results provide encouraging evidence that AWMT may have generalized benefits in the context of impaired WM capacity following brain injury.

Factors buffering against the effects of job demands: how does age matter?

PubMed

Besen, Elyssa; Matz-Costa, Christina; James, Jacquelyn B; Pitt-Catsouphes, Marcie

2015-02-01

Given the increasing role that paid work is likely to play in older adulthood in the coming decades, the goal of this study was to understand the circumstances under which work is related to mental health for older adults and whether these circumstances differ by age. Using a multiworksite sample of 1,812 U.S. workers age 18 to 81, we use the life-span theory of control to hypothesize that older and younger workers may benefit differentially from job and personal control in the context of high job demands. Results suggest that for younger workers with high personal control, job control buffers the impact of job demands on mental health. For older workers, personal control alone buffers the impact of job demands on mental health. This study adds to previous research by addressing how the factors thought to buffer against the effects of job demands differ cross-sectionally by age. © The Author(s) 2012.

Contextual analysis of fluid intelligence.

PubMed

Salthouse, Timothy A; Pink, Jeffrey E; Tucker-Drob, Elliot M

2008-01-01

The nature of fluid intelligence was investigated by identifying variables that were, and were not, significantly related to this construct. Relevant information was obtained from three sources: re-analyses of data from previous studies, a study in which 791 adults performed storage-plus-processing working memory tasks, and a study in which 236 adults performed a variety of working memory, updating, and cognitive control tasks. The results suggest that fluid intelligence represents a broad individual difference dimension contributing to diverse types of controlled or effortful processing. The analyses also revealed that very few of the age-related effects on the target variables were statistically independent of effects on established cognitive abilities, which suggests most of the age-related influences on a wide variety of cognitive control variables overlap with age-related influences on cognitive abilities such as fluid intelligence, episodic memory, and perceptual speed.

Narrative and framing: a test of an integrated message strategy in the exercise context.

PubMed

Gray, Jennifer B; Harrington, Nancy G

2011-03-01

Health communication interventions encouraging exercise may aid in mitigating the obesity crisis in the United States. Although much research has investigated behavioral predictors of exercise, little work has explored message characteristics most persuasive in the exercise context. The purpose of this study, therefore, was to test a message strategy drawing on previous work in health behavior theory combined with persuasion theories (exemplification theory and prospect theory) to encourage positive exercise attitudes, control beliefs, and intentions. The authors report the results of a controlled experiment testing messages using gain or loss frames and narrative or statistical evidence. Results indicate that gain-framed messages are significantly more successful in promoting positive exercise variables and are perceived as more effective than are loss-framed or control messages. The authors discuss the implications of the results for future research.

Fear-avoidance beliefs and temporal summation of evoked thermal pain influence self-report of disability in patients with chronic low back pain.

PubMed

George, Steven Z; Wittmer, Virgil T; Fillingim, Roger B; Robinson, Michael E

2006-03-01

Quantitative sensory testing has demonstrated a promising link between experimentally determined pain sensitivity and clinical pain. However, previous studies of quantitative sensory testing have not routinely considered the important influence of psychological factors on clinical pain. This study investigated whether measures of thermal pain sensitivity (temporal summation, first pulse response, and tolerance) contributed to clinical pain reports for patients with chronic low back pain, after controlling for depression or fear-avoidance beliefs about work. Consecutive patients (n=27) with chronic low back pain were recruited from an interdisciplinary pain rehabilitation program in Jacksonville, FL. Patients completed validated self-report questionnaires for depression, fear-avoidance beliefs, clinical pain intensity, and clinical pain related disability. Patients also underwent quantitative sensory testing from previously described protocols to determine thermal pain sensitivity (temporal summation, first pulse response, and tolerance). Hierarchical regression models investigated the contribution of depression and thermal pain sensitivity to clinical pain intensity, and fear-avoidance beliefs and thermal pain sensitivity to clinical pain related disability. None of the measures of thermal pain sensitivity contributed to clinical pain intensity after controlling for depression. Temporal summation of evoked thermal pain significantly contributed to clinical pain disability after controlling for fear-avoidance beliefs about work. Measures of thermal pain sensitivity did not contribute to pain intensity, after controlling for depression. Fear-avoidance beliefs about work and temporal summation of evoked thermal pain significantly influenced pain related disability. These factors should be considered as potential outcome predictors for patients with work-related low back pain. This study supported the neuromatrix theory of pain for patients with CLBP, as cognitive-evaluative factor contributed to pain perception, and cognitive-evaluative and sensory-discriminative factors uniquely contributed to an action program in response to chronic pain. Future research will determine if a predictive model consisting of fear-avoidance beliefs and temporal summation of evoked thermal pain has predictive validity for determining clinical outcome in rehabilitation or vocational settings.

Recall initiation strategies must be controlled in training studies that use immediate free recall tasks to measure the components of working memory capacity across time.

PubMed

Gibson, Bradley S; Gondoli, Dawn M; Johnson, Ann C; Robison, Matthew K

2014-01-01

There has been great interest in using working memory (WM) training regimens as an alternative treatment for ADHD, but it has recently been concluded that existing training regimens may not be optimally designed because they target the primary memory component but not the secondary component of WM capacity. This conclusion requires the ability to accurately measure changes in primary and secondary memory abilities over time. The immediate free recall task has been used in previous studies to measure these changes; however, one concern with these tasks is that the recall order required on training exercises may influence the recall strategy used during free recall, which may in turn influence the relative number of items recalled from primary and secondary memory. To address this issue, previous training studies have explicitly controlled recall strategy before and after training. However, the necessity of controlling for recall strategies has not been explicitly tested. The present study investigated the effects of forward-serial-order training on free recall performance under conditions in which recall strategy was not controlled using a sample of adolescents with ADHD. Unlike when recall order was controlled, the main findings showed selective improvement of the secondary memory component (as opposed to the primary memory component) when recall order was uncontrolled. This finding advances our understanding of WM training by highlighting the importance of controlling for recall strategies when free recall tasks are used to measure changes in the primary and secondary components of WM across time.

Control Systems of Rubber Dryer Machinery Components Using Programmable Logic Control (PLC)

NASA Astrophysics Data System (ADS)

Hendra; Yulianto, A. S.; Indriani, A.; Hernadewita; Hermiyetti

2018-02-01

Application of programmable logic control (PLC) is widely used on the control systems in the many field engineering such as automotive, aviation, food processing and other industries [1-2]. PLC is simply program to control many automatic activity, easy to use, flexible and others. PLC using the ladder program to solve and regulated the control system component. In previous research, PLC was used for control system of rotary dryer machine. In this paper PLC are used for control system of motion component in the rubber dryer machinery. Component of rubber dryer machine is motors, gearbox, sprocket, heater, drying chamber and bearing. Principle working of rubber dryer machinery is wet rubber moving into the drying chamber by sprocket. Sprocket is driven by motors that conducted by PLC to moving and set of wet rubber on the drying chamber. Drying system uses greenhouse effect by making hanger dryer design in the form of line path. In this paper focused on motion control system motors and sensors drying rubber using PLC. The results show that control system of rubber dryer machinery can work in accordance control input and the time required to dry the rubber.

Working conditions, job strain and work engagement among Belgian radiation oncologists.

PubMed

Bragard, I; Hansez, I; Coucke, P

2014-12-01

This national survey has measured the working conditions, work engagement, job strain, burn out, and the negative work-home interaction among Belgian radiation oncologists with validated questionnaires. In fact, previous studies had in general shown an interest to burn out and its association with working conditions among oncology workers, but not focused on radiation oncologists in particular. Moreover, few studies concerned work engagement and its association with working conditions although this could be important in preventing burn out. We used the WOrking Conditions and Control Questionnaire, the Positive and Negative Occupational States Inventory, the Maslach Burn out Inventory, and the negative work-home interaction subscale of the Survey Work-home Interaction Nijmegen. One open question asked about problematic job situations. Sixty-six radiation oncologists participated (30% response rate). Median scores of most of working conditions corresponded to normal scores. Control over time management (45.8) was close to low score, while control over future (60.9) was high. Median score of job strain (48.9) was normal, whereas median score of work engagement (60) was high. Median score of burn out was low. The mean of negative work-home interactions (1.1) was higher than the mean of 0.84 in a reference sample (t=4.3; P<0.001). The most frequent problematic situations referred to work organization (e.g. time pressure) and specific resources (e.g. chief support). Radiation oncologists showed a very high level of work engagement and experienced several job resources. However, some resources (as supervisor support) were missing and needed to be developed. These results were discussed in the context of motivational process described in the Job Demands-Resources Model. Copyright © 2014 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

A prospective study of musculoskeletal outcomes among manufacturing workers: II. Effects of psychosocial stress and work organization factors.

PubMed

Gerr, Fredric; Fethke, Nathan B; Anton, Dan; Merlino, Linda; Rosecrance, John; Marcus, Michele; Jones, Michael P

2014-02-01

The aim of this study was to characterize associations between psychosocial and work organizational risk factors and upper-extremity musculoskeletal symptoms and disorders. Methodological limitations of previous studies of psychosocial and work organizational risk factors and musculoskeletal outcomes have produced inconsistent associations. In this prospective epidemiologic study of 386 workers, questionnaires to assess decision latitude ("control") and psychological job demands ("demand") were administered to study participants and were used to classify them into job strain "quadrants". Measures of job stress and job change were collected during each week of follow-up. Incident hand/arm and neck/shoulder symptoms and disorders were ascertained weekly. Associations between exposure measures and musculoskeletal outcomes were estimated with proportional hazard methods. When compared to the low-demand/high-control job strain referent category, large increases in risk of hand/arm disorders were observed for both high-demand/high-control (hazard ratio [HR] = 4.49, 95% confidence interval [CI] = [1.23, 16.4]) and high-demand/low-control job strain categories (HR = 5.18,95% CI = [1.39, 19.4]). Similar associations were observed for hand/arm symptoms. A strong association was also observed between the low-demand/low-control job strain category and neck/shoulder disorders (HR = 6.46, 95% CI = [1.46, 28.6]). Statistically significant associations were also observed between weekly stress level and weekly job change and several musculoskeletal outcomes. Associations between psychosocial risk factors and work organizational factors and musculoskeletal outcomes were large and in the hypothesized direction. Prevention of occupational musculoskeletal disorders may require attention to psychosocial and work organizational factors in addition to physical factors. Methods to control adverse effects of psychosocial and work organizational risk factors should be explored.

Field testing of feedforward collective pitch control on the CART2 using a nacelle-based Lidar scanner

DOE PAGES

Schlipf, David; Fleming, Paul; Haizmann, Florian; ...

2014-12-16

This work presents the results from a field test of LIDAR assisted collective pitch control using a scanning LIDAR device installed on the nacelle of a mid-scale research turbine. A nonlinear feedforward controller is extended by an adaptive filter to remove all uncorrelated frequencies of the wind speed measurement to avoid unnecessary control action. Positive effects on the rotor speed regulation as well as on tower, blade and shaft loads have been observed in the case that the previous measured correlation and timing between the wind preview and the turbine reaction are accomplish. The feedforward controller had negative impact, whenmore » the LIDAR measurement was disturbed by obstacles in front of the turbine. This work proves, that LIDAR is valuable tool for wind turbine control not only in simulations but also under real conditions. Moreover, the paper shows that further understanding of the relationship between the wind measurement and the turbine reaction is crucial to improve LIDAR assisted control of wind turbines.« less

Nonlinear Burn Control in Tokamaks using Heating, Non-axisymmetric Magnetic Fields, Isotopic fueling and Impurity injection

NASA Astrophysics Data System (ADS)

Pajares, Andres; Schuster, Eugenio

2016-10-01

Plasma density and temperature regulation in future tokamaks such as ITER is arising as one of the main problems in nuclear-fusion control research. The problem, known as burn control, is to regulate the amount of fusion power produced by the burning plasma while avoiding thermal instabilities. Prior work in the area of burn control considered different actuators, such as modulation of the auxiliary power, modulation of the fueling rate, and controlled impurity injection. More recently, the in-vessel coil system was suggested as a feasible actuator since it has the capability of modifying the plasma confinement by generating non-axisymmetric magnetic fields. In this work, a comprehensive, model-based, nonlinear burn control strategy is proposed to integrate all the previously mentioned actuators. A model to take into account the influence of the in-vessel coils on the plasma confinement is proposed based on the plasma collisionality and the density. A simulation study is carried out to show the capability of the controller to drive the system between different operating points while rejecting perturbations. Supported by the US DOE under DE-SC0010661.

Working memory and the strategic control of attention in older and younger adults.

PubMed

Hayes, Melissa G; Kelly, Andrew J; Smith, Anderson D

2013-03-01

The objective of this study was to investigate the effects of aging on the strategic control of attention and the extent to which this relationship is mediated by working memory capacity (WMC). This study also sought to investigate boundary conditions wherein age differences in selectivity may occur. Across 2 studies, the value-directed remembering task used by Castel and colleagues (Castel, A. D., Balota, D. A., & McCabe, D. P. (2009). Memory efficiency and the strategic control of attention at encoding: Impairments of value-directed remembering in Alzheimer's Disease. Neuropsychology, 23, 297-306) was modified to include value-directed forgetting. Study 2 incorporated valence as an additional task demand, and age differences were predicted in both studies due to increased demands of controlled processing. Automated operation span and Stroop span were included as working memory measures, and working memory was predicted to mediate performance. Results confirmed these predictions, as older adults were less efficient in maximizing selectivity scores when high demands were placed on selectivity processes, and working memory was found to mediate performance on this task. When list length was increased from previous studies and participants were required to actively forget negative-value words, older adults were not able to selectively encode high-value information to the same degree as younger adults. Furthermore, WMC appears to support the ability to selectively encode information.

On the Traceability of Commercial Saffron Samples Using ¹H-NMR and FT-IR Metabolomics.

PubMed

Consonni, Roberto; Ordoudi, Stella A; Cagliani, Laura R; Tsiangali, Maria; Tsimidou, Maria Z

2016-02-29

In previous works on authentic samples of saffron of known history (harvest and processing year, storage conditions, and length of time) some biomarkers were proposed using both FT-IR and NMR metabolomics regarding the shelf life of the product. This work addresses the difficulties to trace back the "age" of commercial saffron samples of unknown history, sets a limit value above which these products can be considered substandard, and offers a useful tool to combat saffron mislabeling and fraud with low-quality saffron material. Investigations of authentic and commercial saffron samples of different origin and harvest year, which had been stored under controlled conditions for different lengths of time, allowed a clear-cut clustering of samples in two groups according to the storage period irrespectively of the provenience. In this respect, the four-year cut off point proposed in our previous work assisted to trace back the "age" of unknown samples and to check for possible mislabeling practices.

Working hours and cardiovascular disease in Korean workers: a case-control study.

PubMed

Jeong, Inchul; Rhie, Jeongbae; Kim, Inah; Ryu, Innshil; Jung, Pil Kyun; Park, Yoo Seok; Lim, Yong-Su; Kim, Hyoung-Ryoul; Park, Shin-Goo; Im, Hyoung-June; Lee, Mi-Young; Won, Jong-Uk

2014-01-01

Long working hours can negatively impact a worker's health. The objective of this study was to examine the association between working hours and cardiovascular diseases (CVDs) and compare the degree of risk based on CVD subtypes in Korean workers. This study was a case-control study of the patients registered in the Occupational Cardiovascular Diseases Surveillance 2010. The cases included 348 patients diagnosed with a CVD (123 cerebral infarction, 69 intracerebral hemorrhage, 57 subarachnoid hemorrhage, 99 acute myocardial infarction). Controls were 769 participants with no history of CVDs matched for gender, age, type of occupation, and region. Participants' working hours in the previous week and the average working hours over the past three months were assessed to examine short-term and long-term effects. After adjusting for confounding factors, the odds ratios (ORs) for CVDs in the short-term were 2.66 (95% Confidence interval (CI) :1.78-3.99) for working ≤40 hours, 1.85 (95% CI: 1.22-2.81) for working 50.1-60 hours and 4.23 (95% CI: 2.81-6.39) for working >60 hours compared with the 40.1-50-hour working group. The ORs in the long-term were 2.90 (95% CI: 1.86-4.52) for working ≤40 hours, 1.73 (95% CI: 1.03-2.90) for working 48.1-52 hours and 3.46 (95% CI: 2.38-5.03) for working >52 hours compared with the 40.1-48-hour working group. Long working hours are related to an increased risk of CVDs, and the degree of risk differs based on CVD subtype. Short working hours are also related to an increased risk for CVDs. More prospective studies targeting specific disease risks are required.

Factors influencing return-to-work after cerebrovascular disease: the importance of previous cardiovascular risk.

PubMed

Catalina-Romero, Carlos; Ruilope, Luis Miguel; Sánchez-Chaparro, Miguel Angel; Valdivielso, Pedro; Cabrera-Sierra, Martha; Fernández-Labandera, Carlos; Ruiz-Moraga, Montserrat; Gonzalez-Quintela, Arturo; Calvo-Bonacho, Eva

2015-09-01

The role of prior cardiovascular risk (CVR) in the multifactorial process of returning to work after a cerebrovascular event has not been adequately investigated. Therefore, the objective of the present study was to analyse the association between previous CVR level, cardiovascular risk factors (CVRFs) and return-to-work (RTW) following cerebrovascular disease. This was a prospective observational study. We analysed a cohort of 348 patients who had experienced an episode of cerebrovascular disease-related work absence. These individuals were selected from the ICARIA study (Ibermutuamur CArdiovascular RIsk Assessment). Global CVR was assessed using the SCORE system. We investigated the association between demographics, work-related variables, CVRFs and RTW following a cerebrovascular event. We found that a total of 254 individuals (73.0%; 95% CI: 68.3-77.7) returned to work after cerebrovascular disease. Also, we observed a median loss of 12 working years due to disability. Moreover, adjusting for potential confounders revealed that low CVR level and the absence of the following CVRFs was associated with a higher likelihood of RTW: low vs moderate-to-high CVR level (OR: 2.55; 95% CI: 1.42-4.57), no hypertension before stroke (OR: 1.95; 95% CI: 1.11-3.41), non-smoker status (OR: 2.26; 95% CI: 1.30-3.93) and no previous diabetes (OR: 2.46; 95% CI: 1.26-4.79). Low CVR, along with the absence of several CVRFs, can be used to predict RTW rates following cerebrovascular events. Therefore, controlling hypertension, tobacco consumption and diabetes might contribute to the effectiveness of multidisciplinary rehabilitation and/or secondary/tertiary prevention programs for cerebrovascular disease. © The European Society of Cardiology 2014.

Learning-based controller for biotechnology processing, and method of using

DOEpatents

Johnson, John A.; Stoner, Daphne L.; Larsen, Eric D.; Miller, Karen S.; Tolle, Charles R.

2004-09-14

The present invention relates to process control where some of the controllable parameters are difficult or impossible to characterize. The present invention relates to process control in biotechnology of such systems, but not limited to. Additionally, the present invention relates to process control in biotechnology minerals processing. In the inventive method, an application of the present invention manipulates a minerals bioprocess to find local exterma (maxima or minima) for selected output variables/process goals by using a learning-based controller for bioprocess oxidation of minerals during hydrometallurgical processing. The learning-based controller operates with or without human supervision and works to find processor optima without previously defined optima due to the non-characterized nature of the process being manipulated.

Validating a UAV artificial intelligence control system using an autonomous test case generator

NASA Astrophysics Data System (ADS)

Straub, Jeremy; Huber, Justin

2013-05-01

The validation of safety-critical applications, such as autonomous UAV operations in an environment which may include human actors, is an ill posed problem. To confidence in the autonomous control technology, numerous scenarios must be considered. This paper expands upon previous work, related to autonomous testing of robotic control algorithms in a two dimensional plane, to evaluate the suitability of similar techniques for validating artificial intelligence control in three dimensions, where a minimum level of airspeed must be maintained. The results of human-conducted testing are compared to this automated testing, in terms of error detection, speed and testing cost.

A representational basis for the development of a distributed expert system for Space Shuttle flight control

NASA Technical Reports Server (NTRS)

Helly, J. J., Jr.; Bates, W. V.; Cutler, M.; Kelem, S.

1984-01-01

A new representation of malfunction procedure logic which permits the automation of these procedures using Boolean normal forms is presented. This representation is discussed in the context of the development of an expert system for space shuttle flight control including software and hardware implementation modes, and a distributed architecture. The roles and responsibility of the flight control team as well as previous work toward the development of expert systems for flight control support at Johnson Space Center are discussed. The notion of malfunction procedures as graphs is introduced as well as the concept of hardware-equivalence.

Mineback Stimulation Research Experiments

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

Warpinski, N.R.

The objective of the Mineback Stimulation Research Experiments is to improve hydraulic fracture stimulation technology by providing an in situ laboratory where basic processes and mechanisms that control and influence fracture propagation can be observed, measured and understood. While previous tests have been instrumental in providing an understanding of the mechanisms controlling fracture height, current experiments are focused on fluid flow through the created fracture and the associated pressure drops and crack widths. Work performed, accomplishments and future plans are presented. 7 refs., 2 figs.

The impact of cognitive control, incentives, and working memory load on the P3 responses of externalizing prisoners.

PubMed

Baskin-Sommers, Arielle R; Krusemark, Elizabeth A; Curtin, John J; Lee, Christopher; Vujnovich, Aleice; Newman, Joseph P

2014-02-01

The P3 amplitude reduction is one of the most common correlates of externalizing. However, few studies have used experimental manipulations designed to challenge different cognitive functions in order to clarify the processes that impact this reduction. To examine factors moderating P3 amplitude in trait externalizing, we administered an n-back task that manipulated cognitive control demands, working memory load, and incentives to a sample of male offenders. Offenders with high trait externalizing scores did not display a global reduction in P3 amplitude. Rather, the negative association between trait externalizing and P3 amplitude was specific to trials involving inhibition of a dominant response during infrequent stimuli, in the context of low working memory load, and incentives for performance. In addition, we discuss the potential implications of these findings for externalizing-related psychopathologies. The results complement and expand previous work on the process-level dysfunction contributing to externalizing-related deficits in P3. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis Methods for Robust Passification and Control

NASA Technical Reports Server (NTRS)

Kelkar, Atul G.; Joshi, Suresh M. (Technical Monitor)

2000-01-01

The research effort under this cooperative agreement has been essentially the continuation of the work from previous grants. The ongoing work has primarily focused on developing passivity-based control techniques for Linear Time-Invariant (LTI) systems. During this period, there has been a significant progress made in the area of passivity-based control of LTI systems and some preliminary results have also been obtained for nonlinear systems, as well. The prior work has addressed optimal control design for inherently passive as well as non- passive linear systems. For exploiting the robustness characteristics of passivity-based controllers the passification methodology was developed for LTI systems that are not inherently passive. Various methods of passification were first proposed in and further developed. The robustness of passification was addressed for multi-input multi-output (MIMO) systems for certain classes of uncertainties using frequency-domain methods. For MIMO systems, a state-space approach using Linear Matrix Inequality (LMI)-based formulation was presented, for passification of non-passive LTI systems. An LMI-based robust passification technique was presented for systems with redundant actuators and sensors. The redundancy in actuators and sensors was used effectively for robust passification using the LMI formulation. The passification was designed to be robust to an interval-type uncertainties in system parameters. The passification techniques were used to design a robust controller for Benchmark Active Control Technology wing under parametric uncertainties. The results on passive nonlinear systems, however, are very limited to date. Our recent work in this area was presented, wherein some stability results were obtained for passive nonlinear systems that are affine in control.

A Novel Switching-Based Control Framework for Improved Task Performance in Teleoperation System With Asymmetric Time-Varying Delays.

PubMed

Zhai, Di-Hua; Xia, Yuanqing

2018-02-01

This paper addresses the adaptive control for task-space teleoperation systems with constrained predefined synchronization error, where a novel switched control framework is investigated. Based on multiple Lyapunov-Krasovskii functionals method, the stability of the resulting closed-loop system is established in the sense of state-independent input-to-output stability. Compared with previous work, the developed method can simultaneously handle the unknown kinematics/dynamics, asymmetric varying time delays, and prescribed performance control in a unified framework. It is shown that the developed controller can guarantee the prescribed transient-state and steady-state synchronization performances between the master and slave robots, which is demonstrated by the simulation study.

Direct imaging of slow, stored and stationary EIT polaritons

NASA Astrophysics Data System (ADS)

Campbell, Geoff T.; Cho, Young-Wook; Su, Jian; Everett, Jesse; Robins, Nicholas; Lam, Ping Koy; Buchler, Ben

2017-09-01

Stationary and slow light effects are of great interest for quantum information applications. Using laser-cooled Rb87 atoms, we performed side imaging of our atomic ensemble under slow and stationary light conditions, which allows direct comparison with numerical models. The polaritons were generated using electromagnetically induced transparency (EIT), with stationary light generated using counter-propagating control fields. By controlling the power ratio of the two control fields, we show fine control of the group velocity of the stationary light. We also compare the dynamics of stationary light using monochromatic and bichromatic control fields. Our results show negligible difference between the two situations, in contrast to previous work in EIT-based systems.

Debilitating lung disease among surface coal miners with no underground mining tenure.

PubMed

Halldin, Cara N; Reed, William R; Joy, Gerald J; Colinet, Jay F; Rider, James P; Petsonk, Edward L; Abraham, Jerrold L; Wolfe, Anita L; Storey, Eileen; Laney, A Scott

2015-01-01

To characterize exposure histories and respiratory disease among surface coal miners identified with progressive massive fibrosis from a 2010 to 2011 pneumoconiosis survey. Job history, tenure, and radiograph interpretations were verified. Previous radiographs were reviewed when available. Telephone follow-up sought additional work and medical history information. Among eight miners who worked as drill operators or blasters for most of their tenure (median, 35.5 years), two reported poor dust control practices, working in visible dust clouds as recently as 2012. Chest radiographs progressed to progressive massive fibrosis in as few as 11 years. One miner's lung biopsy demonstrated fibrosis and interstitial accumulation of macrophages containing abundant silica, aluminum silicate, and titanium dust particles. Overexposure to respirable silica resulted in progressive massive fibrosis among current surface coal miners with no underground mining tenure. Inadequate dust control during drilling/blasting is likely an important etiologic factor.

Debilitating Lung Disease Among Surface Coal Miners With No Underground Mining Tenure

PubMed Central

Halldin, Cara N.; Reed, William R.; Joy, Gerald J.; Colinet, Jay F.; Rider, James P.; Petsonk, Edward L.; Abraham, Jerrold L.; Wolfe, Anita L.; Storey, Eileen; Laney, A. Scott

2015-01-01

Objective To characterize exposure histories and respiratory disease among surface coal miners identified with progressive massive fibrosis from a 2010 to 2011 pneumoconiosis survey. Methods Job history, tenure, and radiograph interpretations were verified. Previous radiographs were reviewed when available. Telephone follow-up sought additional work and medical history information. Results Among eight miners who worked as drill operators or blasters for most of their tenure (median, 35.5 years), two reported poor dust control practices, working in visible dust clouds as recently as 2012. Chest radiographs progressed to progressive massive fibrosis in as few as 11 years. One miner’s lung biopsy demonstrated fibrosis and interstitial accumulation of macrophages containing abundant silica, aluminum silicate, and titanium dust particles. Conclusions Overexposure to respirable silica resulted in progressive massive fibrosis among current surface coal miners with no underground mining tenure. Inadequate dust control during drilling/blasting is likely an important etiologic factor. PMID:25563541

The Role of Grain Boundary Energy on Grain Boundary Complexion Transitions

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

Bojarski, Stephanie A.; Rohrer, Gregory S.

Grain boundary complexions are distinct equilibrium structures and compositions of a grain boundary and complexion transformations are transition from a metastable to an equilibrium complexion at a specific thermodynamic and geometric conditions. Previous work indicates that, in the case of doped alumina, a complexion transition that increased the mobility of transformed boundaries and resulted in abnormal grain growth also caused a decrease in the mean relative grain boundary energy as well as an increase in the anisotropy of the grain boundary character distribution (GBCD). The current work will investigate the hypothesis that the rates of complexion transitions that result inmore » abnormal grain growth (AGG) depend on grain boundary character and energy. Furthermore, the current work expands upon this understanding and tests the hypothesis that it is possible to control when and where a complexion transition occurs by controlling the local grain boundary energy distribution.« less

Energy absorption in aluminum extrusions for a spaceframe chassis

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

Logan, R.W.; Perfect, S.A.; Parkinson, R.D.

1994-09-19

This work describes the design, finite-element analysis, and verifications performed by LLNL and Kaiser Aluminum for the prototype design of the CALSTART Running Chassis purpose-built electric vehicle. Component level studies, along with our previous experimental and finite-element works, provided the confidence to study the crashworthiness of a complete aluminum spaceframe. Effects of rail geometry, size, and thickness were studied in order to achieve a controlled crush of the front end structure. These included the performance of the spaceframe itself, and the additive effects of the powertrain cradle and powertrain (motor/controller in this case) as well as suspension. Various design iterationsmore » for frontal impact at moderate and high speed are explored.« less

Effect of US health policies on health care access for Marshallese migrants.

PubMed

McElfish, Pearl Anna; Hallgren, Emily; Yamada, Seiji

2015-04-01

The Republic of the Marshall Islands is a sovereign nation previously under the administrative control of the United States. Since 1986, the Compacts of Free Association (COFA) between the Republic of the Marshall Islands and the United States allows Marshall Islands citizens to freely enter, lawfully reside, and work in the United States, and provides the United States exclusive military control of the region. When the COFA was signed, COFA migrants were eligible for Medicaid and other safety net programs. However, these migrants were excluded from benefits as a consequence of the Personal Responsibility and Work Opportunity Reconciliation Act. Currently, COFA migrants have limited access to health care benefits in the United States, which perpetuates health inequalities.

Effect of US Health Policies on Health Care Access for Marshallese Migrants

PubMed Central

Hallgren, Emily; Yamada, Seiji

2015-01-01

The Republic of the Marshall Islands is a sovereign nation previously under the administrative control of the United States. Since 1986, the Compacts of Free Association (COFA) between the Republic of the Marshall Islands and the United States allows Marshall Islands citizens to freely enter, lawfully reside, and work in the United States, and provides the United States exclusive military control of the region. When the COFA was signed, COFA migrants were eligible for Medicaid and other safety net programs. However, these migrants were excluded from benefits as a consequence of the Personal Responsibility and Work Opportunity Reconciliation Act. Currently, COFA migrants have limited access to health care benefits in the United States, which perpetuates health inequalities. PMID:25713965

Freeform Fluidics

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

Love, Lonnie J; Richardson, Bradley S; Lind, Randall F

This work explores the integration of miniaturized fluid power and additive manufacturing. Oak Ridge National Laboratory (ORNL) has been developing an approach to miniaturized fluidic actuation and control that enables high dexterity, low cost and a pathway towards energy efficiency. Previous work focused on mesoscale digital control valves (high pressure, low flow) and the integration of actuation and fluid passages directly with the structure. The primary application being fluid powered robotics. The fundamental challenge was part complexity. Additive manufacturing technologies (E-Beam, Laser and Ultrasonic deposition) enable freeform manufacturing using conventional metal alloys with excellent mechanical properties. The combination of thesemore » two technologies (miniaturized fluid power and additive manufacturing) can enable a paradigm shift in fluid power, increasing efficiency while simultaneously reducing weight, size, complexity and cost.« less

31P-MRS demonstrates a reduction in high-energy phosphates in the occipital lobe of migraine without aura patients.

PubMed

Reyngoudt, Harmen; Paemeleire, Koen; Descamps, Benedicte; De Deene, Yves; Achten, Eric

2011-09-01

Differences in brain energy metabolism have been found between migraine patients and controls in previous phosphorus magnetic resonance spectroscopy ((31)P-MRS) studies, most of them emphasizing migraine with aura (MwA). The aim of this study was to verify potential changes in resting-state brain energy metabolism in patients with migraine without aura (MwoA) compared to control subjects by (31)P-MRS at 3 tesla. Quantification was performed using the phantom replacement technique. MRS measurements were performed interictally and in the medial occipital lobe of 19 MwoA patients and 26 age-matched controls. A significantly decreased phosphocreatine concentration ([PCr]) was found as in previous studies. While adenosine triphosphate concentration ([ATP]) was considered to be constant in previously published work, this study found a significant decrease in the measured [ATP] in MwoA patients. The inorganic phosphate ([P(i)]) and magnesium ([Mg(2+)]) concentrations were not significantly different between MwoA patients and controls. The altered metabolic concentrations indicate that the energy metabolism in MwoA patients is impaired, certainly in a subgroup of patients. The actual decrease in [ATP] adds further strength to the theory of the presence of a mitochondrial component in the pathophysiology of migraine.

Spatial-Sequential Working Memory in Younger and Older Adults: Age Predicts Backward Recall Performance within Both Age Groups

PubMed Central

Brown, Louise A.

2016-01-01

Working memory is vulnerable to age-related decline, but there is debate regarding the age-sensitivity of different forms of spatial-sequential working memory task, depending on their passive or active nature. The functional architecture of spatial working memory was therefore explored in younger (18–40 years) and older (64–85 years) adults, using passive and active recall tasks. Spatial working memory was assessed using a modified version of the Spatial Span subtest of the Wechsler Memory Scale – Third Edition (WMS-III; Wechsler, 1998). Across both age groups, the effects of interference (control, visual, or spatial), and recall type (forward and backward), were investigated. There was a clear effect of age group, with younger adults demonstrating a larger spatial working memory capacity than the older adults overall. There was also a specific effect of interference, with the spatial interference task (spatial tapping) reliably reducing performance relative to both the control and visual interference (dynamic visual noise) conditions in both age groups and both recall types. This suggests that younger and older adults have similar dependence upon active spatial rehearsal, and that both forward and backward recall require this processing capacity. Linear regression analyses were then carried out within each age group, to assess the predictors of performance in each recall format (forward and backward). Specifically the backward recall task was significantly predicted by age, within both the younger and older adult groups. This finding supports previous literature showing lifespan linear declines in spatial-sequential working memory, and in working memory tasks from other domains, but contrasts with previous evidence that backward spatial span is no more sensitive to aging than forward span. The study suggests that backward spatial span is indeed more processing-intensive than forward span, even when both tasks include a retention period, and that age predicts backward spatial span performance across the adult lifespan, within both younger and older adulthood. PMID:27757096

Spatial-Sequential Working Memory in Younger and Older Adults: Age Predicts Backward Recall Performance within Both Age Groups.

PubMed

Brown, Louise A

2016-01-01

Working memory is vulnerable to age-related decline, but there is debate regarding the age-sensitivity of different forms of spatial-sequential working memory task, depending on their passive or active nature. The functional architecture of spatial working memory was therefore explored in younger (18-40 years) and older (64-85 years) adults, using passive and active recall tasks. Spatial working memory was assessed using a modified version of the Spatial Span subtest of the Wechsler Memory Scale - Third Edition (WMS-III; Wechsler, 1998). Across both age groups, the effects of interference (control, visual, or spatial), and recall type (forward and backward), were investigated. There was a clear effect of age group, with younger adults demonstrating a larger spatial working memory capacity than the older adults overall. There was also a specific effect of interference, with the spatial interference task (spatial tapping) reliably reducing performance relative to both the control and visual interference (dynamic visual noise) conditions in both age groups and both recall types. This suggests that younger and older adults have similar dependence upon active spatial rehearsal, and that both forward and backward recall require this processing capacity. Linear regression analyses were then carried out within each age group, to assess the predictors of performance in each recall format (forward and backward). Specifically the backward recall task was significantly predicted by age, within both the younger and older adult groups. This finding supports previous literature showing lifespan linear declines in spatial-sequential working memory, and in working memory tasks from other domains, but contrasts with previous evidence that backward spatial span is no more sensitive to aging than forward span. The study suggests that backward spatial span is indeed more processing-intensive than forward span, even when both tasks include a retention period, and that age predicts backward spatial span performance across the adult lifespan, within both younger and older adulthood.

On the influence of particle morphology on the post-impact ballistic response of ceramic armour materials

NASA Astrophysics Data System (ADS)

Hameed, Amer; Appleby-Thomas, Gareth; Wood, David; Jaansalu, Kevin

2015-06-01

Recent studies have shown evidence that the ballistic-resistance of fragmented (comminuted) ceramics is independent of the original strength of the material. In particular, experimental investigations into the ballistic behaviour of such fragmented ceramics have indicated that this response is correlated to shattered ceramic morphology. This suggests that careful control of ceramic microstructure - and therefore failure paths - might provide a route to optimise post-impact ballistic performance, thereby enhancing multi-hit capability. In this study, building on previous in-house work, ballistic tests were conducted using pre-formed `fragmented-ceramic' analogues based around three morphologically differing (but chemically identical) alumina feedstock materials compacted into target `pucks. In an evolution of previous work, variation of target thickness provided additional insight into an apparent morphology-based contribution to ballistic response.

Can PC-9 Zhong chong replace K-1 Yong quan for the acupunctural resuscitation of a bilateral double-amputee? Stating the “random criterion problem” in its statistical analysis

PubMed Central

Inchauspe, Adrián Angel

2016-01-01

AIM: To present an inclusion criterion for patients who have suffered bilateral amputation in order to be treated with the supplementary resuscitation treatment which is hereby proposed by the author. METHODS: This work is based on a Retrospective Cohort model so that a certainly lethal risk to the control group is avoided. RESULTS: This paper presents a hypothesis on acupunctural PC-9 Zhong chong point, further supported by previous statistical work recorded for the K-1 Yong quan resuscitation point. CONCLUSION: Thanks to the application of the resuscitation maneuver herein proposed on the previously mentioned point, patients with bilateral amputation would have another alternative treatment available in case basic and advanced CPR should fail. PMID:27152257

Finite-time synchronization control of a class of memristor-based recurrent neural networks.

PubMed

Jiang, Minghui; Wang, Shuangtao; Mei, Jun; Shen, Yanjun

2015-03-01

This paper presents a global and local finite-time synchronization control law for memristor neural networks. By utilizing the drive-response concept, differential inclusions theory, and Lyapunov functional method, we establish several sufficient conditions for finite-time synchronization between the master and corresponding slave memristor-based neural network with the designed controller. In comparison with the existing results, the proposed stability conditions are new, and the obtained results extend some previous works on conventional recurrent neural networks. Two numerical examples are provided to illustrate the effective of the design method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mechanical control of Renilla luciferase.

PubMed

Tseng, Chiao-Yu; Zocchi, Giovanni

2013-08-14

We report experiments where the activity of the enzyme luciferase from Renilla reniformis is controlled through a DNA spring attached to the enzyme. In the wake of previous work on kinases, these results establish that mechanical stress applied through the DNA springs is indeed a general method for the artificial control of enzymes, and for the quantitative study of mechano-chemical coupling in these molecules. We also show proof of concept of the luciferase construct as a sensitive molecular probe, detecting a specific DNA target sequence in an easy, one-step, homogeneous assay, as well as SNP detection without melting curve analysis.

Punishment Sensitivity Predicts the Impact of Punishment on Cognitive Control

PubMed Central

Braem, Senne; Duthoo, Wout; Notebaert, Wim

2013-01-01

Cognitive control theories predict enhanced conflict adaptation after punishment. However, no such effect was found in previous work. In the present study, we demonstrate in a flanker task how behavioural adjustments following punishment signals are highly dependent on punishment sensitivity (as measured by the Behavioural Inhibition System (BIS) scale): Whereas low punishment-sensitive participants do show increased conflict adaptation after punishment, high punishment-sensitive participants show no such modulation. Interestingly, participants with a high punishment-sensitivity showed an overall reaction time increase after punishments. Our results stress the role of individual differences in explaining motivational modulations of cognitive control. PMID:24058520

Asynchronous discrete control of continuous processes

NASA Astrophysics Data System (ADS)

Kaliski, M. E.; Johnson, T. L.

1984-07-01

The research during this second contract year continued to deal with the development of sound theoretical models for asynchronous systems. Two criteria served to shape the research pursued: the first, that the developed models extend and generalize previously developed research for synchronous discrete control; the second, that the models explicitly address the question of how to incorporate system transition times into themselves. The following sections of this report concisely delineate this year's work. Our original proposal for this research identified four general tasks of investigation: (1.1) Analysis of Qualitative Properties of Asynchronous Hybrid Systems; (1.2) Acceptance and Control for Asynchronous Hybrid Systems.

Expected frontiers: Incorporating weather uncertainty into a policy analysis using an integrated bi-level multi-objective optimization framework

EPA Science Inventory

Weather is the main driver in both plant use of nutrients and fate and transport of nutrients in the environment. In previous work, we evaluated a green tax for control of agricultural nutrients in a bi-level optimization framework that linked deterministic models. In this study,...

The Effects of Education Quality on Income Growth and Mortality Decline

ERIC Educational Resources Information Center

Jamison, Eliot A.; Jamison, Dean T.; Hanushek, Eric A.

2007-01-01

Previous work shows that higher levels of education quality (as measured by international student achievement tests) increase growth rates of national income. This paper begins by confirming those findings in an analysis involving more countries over more time with additional controls. We then use the panel structure of our data to assess whether…

40 CFR Appendix to Subpart G of... - Applicant Questionnaire for Modification of Secondary Treatment Requirements

Code of Federal Regulations, 2014 CFR

2014-07-01

... waters as defined in 40 CFR 125.58(z)? If yes, what are the pollution sources contributing to the stress... amounts of effluent previously discharged from the treatment works for which you are applying for a..., at the ZID boundary, at other areas of potential discharge-related impact, and at reference (control...

40 CFR Appendix to Subpart G of... - Applicant Questionnaire for Modification of Secondary Treatment Requirements

Code of Federal Regulations, 2013 CFR

2013-07-01

... waters as defined in 40 CFR 125.58(z)? If yes, what are the pollution sources contributing to the stress... amounts of effluent previously discharged from the treatment works for which you are applying for a..., at the ZID boundary, at other areas of potential discharge-related impact, and at reference (control...

40 CFR Appendix to Subpart G of... - Applicant Questionnaire for Modification of Secondary Treatment Requirements

Code of Federal Regulations, 2012 CFR

2012-07-01

... waters as defined in 40 CFR 125.58(z)? If yes, what are the pollution sources contributing to the stress... amounts of effluent previously discharged from the treatment works for which you are applying for a..., at the ZID boundary, at other areas of potential discharge-related impact, and at reference (control...

From Accountability to Actionability: Making Sense of Multiple Measures in Local Control Accountability Plans. Policy Brief

ERIC Educational Resources Information Center

Beach, Paul; Thier, Michael; Lench, Sarah Collins; Coleman, Matt

2015-01-01

"Understanding Entry-Level Courses in American Institutions of Higher Education" outlines a study conducted by EPIC that empirically identifies the characteristics of work at the college- and career-readiness level in English/language arts, science, and social sciences courses. Using a previously collected national sample of over two…

Unit area control--its development and application

Treesearch

William E. Hallin

1954-01-01

Thirty years of research in the ponderosa pine and mixed conifer forests of the Sierra of California by Dunning and his associates have shown that previous methods of silviculture were not providing adequate restocking of pine. Analysis of records indicated a new approach was necessary. From this work, new procedures that gave most promise of success were formulated...

30 CFR 48.7 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2014 CFR

2014-07-01

... to new work tasks as mobile equipment operators, drilling machine operators, haulage and conveyor systems operators, roof and ground control machine operators, and those in blasting operations shall not... duties at times or places where production is not the primary objective; on (ii) Supervised operation...

30 CFR 48.27 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., drilling machine operators, haulage and conveyor systems operators, ground control machine operators, AMS... practice in the assigned tasks, and the performance of work duties at times or places where production is..., while under direct and immediate supervision and production is in progress, operation of the machine or...

30 CFR 48.27 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., drilling machine operators, haulage and conveyor systems operators, ground control machine operators, AMS... practice in the assigned tasks, and the performance of work duties at times or places where production is..., while under direct and immediate supervision and production is in progress, operation of the machine or...

30 CFR 48.27 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., drilling machine operators, haulage and conveyor systems operators, ground control machine operators, AMS... practice in the assigned tasks, and the performance of work duties at times or places where production is..., while under direct and immediate supervision and production is in progress, operation of the machine or...

30 CFR 48.27 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., drilling machine operators, haulage and conveyor systems operators, ground control machine operators, AMS... practice in the assigned tasks, and the performance of work duties at times or places where production is..., while under direct and immediate supervision and production is in progress, operation of the machine or...

30 CFR 48.7 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2012 CFR

2012-07-01

... to new work tasks as mobile equipment operators, drilling machine operators, haulage and conveyor systems operators, roof and ground control machine operators, and those in blasting operations shall not... duties at times or places where production is not the primary objective; on (ii) Supervised operation...

30 CFR 48.7 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2011 CFR

2011-07-01

... to new work tasks as mobile equipment operators, drilling machine operators, haulage and conveyor systems operators, roof and ground control machine operators, and those in blasting operations shall not... duties at times or places where production is not the primary objective; on (ii) Supervised operation...

30 CFR 48.7 - Training of miners assigned to a task in which they have had no previous experience; minimum...

Code of Federal Regulations, 2013 CFR

2013-07-01

... to new work tasks as mobile equipment operators, drilling machine operators, haulage and conveyor systems operators, roof and ground control machine operators, and those in blasting operations shall not... duties at times or places where production is not the primary objective; on (ii) Supervised operation...

Family Meals and Child Academic and Behavioral Outcomes

ERIC Educational Resources Information Center

Miller, Daniel P.; Waldfogel, Jane; Han, Wen-Jui

2012-01-01

This study investigates the link between the frequency of family breakfasts and dinners and child academic and behavioral outcomes in a panel sample of 21,400 children aged 5-15. It complements previous work by examining younger and older children separately and by using information on a large number of controls and rigorous analytic methods to…

Collembola population levels 7 years after installation of the North Carolina long term soil productivity study

Treesearch

Robert J. Eaton

2006-01-01

Collembola are among the most abundant microarthropods in terrestrial ecosystems and have been shown to affect litter decomposition and nutrient release rates. Previous work 0-n the Croatan National Forest Long Term Soil Productivity (LTSP) study indicated organic matter removal and vegetation control treatments affected collembolan populations. The present study...

Risk of Substance Use Disorders in Adolescents with Bipolar Disorder

ERIC Educational Resources Information Center

Wilens, Timothy E.; Biederman, Joseph; Kwon, Anne; Ditterline, Jeffrey; Forkner, Peter; Moore, Hadley; Swezey, Allison; Snyder, Lindsey; Henin, Aude; Wozniak, Janet; Faraone, Stephen V.

2004-01-01

Objective: Previous work in adults and youths has suggested that juvenile onset bipolar disorder (BPD) is associated with an elevated risk of substance use disorders (SUD). Considering the public health importance of this issue, the authors now report on a controlled study of adolescents with and without BPD to evaluate the risk of SUD. Method:…

Effectiveness of an experiential workshop for enhancing helping professionals' self-competence in death work in Hong Kong: a randomised controlled trial.

PubMed

Chan, Wallace Chi Ho; Tin, Agnes Fong; Wong, Karen Lok Yi

2017-05-01

Helping professionals require self-competence in coping with the existential and emotional challenges of death work. Previous training often focused on knowledge and skills rather than on this competence. This study aimed to examine the effectiveness of a 3-day workshop in Hong Kong to enhance helping professionals' self-competence in death work. A randomised controlled trial was conducted to examine the effects of the training between January and May 2014. Targeted participants were helping professionals who had been doing death work for at least 6 months. The 112 participants were openly recruited from hospitals and NGOs and were assigned to an intervention group or a waitlist control group. Data were collected at pre-intervention and post-intervention. Primary outcome was self-competence in death work. All participants were grouped for analysing the changes in outcomes at pre-intervention, post-intervention and 3-month follow-up. Participants in the intervention group experienced a significant increase in the total score of the Self-competence in Death Work Scale (SC-DWS) and in scores of the Existential and Emotional subscales of SC-DWS. The positive effects of training on self-competence in death work were maintained at the 3-month follow-up. This study provides evidence of the effectiveness of training in enhancing helping professionals' self-competence in death work. Further research is required to examine the long-term effects of training. © 2016 John Wiley & Sons Ltd.

The PILI@Work Program: a translation of the diabetes prevention program to Native Hawaiian-serving worksites in Hawai'i.

PubMed

Townsend, Claire K M; Miyamoto, Robin E S; Antonio, Mapuana; Zhang, Guangxing; Paloma, Diane; Basques, DeAnna; Braun, Kathryn L; Kaholokula, Joseph Keawe'aimoku

2016-06-01

A previously translated Diabetes Prevention Program Lifestyle Intervention (DPP-LI) was adapted for delivery as a worksite-based intervention, called PILI@Work, to address obesity disparities in Native Hawaiians/Pacific Islanders. This study examined the effectiveness of PILI@Work and factors associated with weight loss at post-intervention. Overweight/obese employees of 15 Native Hawaiian-serving organizations received the 3-month component of PILI@Work. Assessments included weight, systolic/diastolic blood pressure, physical activity and functioning, fat intake, locus of weight control, social support, and self-efficacy. Weight, systolic/diastolic blood pressure, physical functioning, physical activity frequency, fat intake, family support, and eating self-efficacy improved from pre- to post-intervention. Regression analysis indicated that worksite type, decreased diastolic blood pressure, increased physical activity, and more internalized locus of weight control were significantly associated with 3-month weight loss. PILI@Work initiated weight loss in Native Hawaiians/Pacific Islanders. DPP-LI translated to worksite settings and tailored for specific populations can be effective for addressing obesity.

Control Valve Trajectories for SOFC Hybrid System Startup

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

Gorrell, Megan; Banta, Larry; Rosen, William

2012-07-01

Control and management of cathode airflow in a solid oxide fuel cell gas turbine hybrid power system was analyzed using the Hybrid Performance (HyPer) hardware simulation at the National Energy Technology (NETL), U.S. Department of Energy. This work delves into previously unexplored operating practices for HyPer, via simultaneous manipulation of bypass valves and the electric load on the generator. The work is preparatory to the development of a Multi-Input, Multi-Output (MIMO) controller for HyPer. A factorial design of experiments was conducted to acquire data for 81 different combinations of the manipulated variables, which consisted of three air flow control valvesmore » and the electric load on the turbine generator. From this data the response surface for the cathode airflow with respect to bypass valve positions was analyzed. Of particular interest is the control of airflow through the cathode during system startup and during large load swings. This paper presents an algorithm for controlling air mass flow through the cathode based on a modification of the steepest ascent method.« less

On controlling networks of limit-cycle oscillators

NASA Astrophysics Data System (ADS)

Skardal, Per Sebastian; Arenas, Alex

2016-09-01

The control of network-coupled nonlinear dynamical systems is an active area of research in the nonlinear science community. Coupled oscillator networks represent a particularly important family of nonlinear systems, with applications ranging from the power grid to cardiac excitation. Here, we study the control of network-coupled limit cycle oscillators, extending the previous work that focused on phase oscillators. Based on stabilizing a target fixed point, our method aims to attain complete frequency synchronization, i.e., consensus, by applying control to as few oscillators as possible. We develop two types of controls. The first type directs oscillators towards larger amplitudes, while the second does not. We present numerical examples of both control types and comment on the potential failures of the method.

Controlling percolation with limited resources.

PubMed

Schröder, Malte; Araújo, Nuno A M; Sornette, Didier; Nagler, Jan

2017-12-01

Connectivity, or the lack thereof, is crucial for the function of many man-made systems, from financial and economic networks over epidemic spreading in social networks to technical infrastructure. Often, connections are deliberately established or removed to induce, maintain, or destroy global connectivity. Thus, there has been a great interest in understanding how to control percolation, the transition to large-scale connectivity. Previous work, however, studied control strategies assuming unlimited resources. Here, we depart from this unrealistic assumption and consider the effect of limited resources on the effectiveness of control. We show that, even for scarce resources, percolation can be controlled with an efficient intervention strategy. We derive such an efficient strategy and study its implications, revealing a discontinuous transition as an unintended side effect of optimal control.

Controlling percolation with limited resources

NASA Astrophysics Data System (ADS)

Schröder, Malte; Araújo, Nuno A. M.; Sornette, Didier; Nagler, Jan

2017-12-01

Connectivity, or the lack thereof, is crucial for the function of many man-made systems, from financial and economic networks over epidemic spreading in social networks to technical infrastructure. Often, connections are deliberately established or removed to induce, maintain, or destroy global connectivity. Thus, there has been a great interest in understanding how to control percolation, the transition to large-scale connectivity. Previous work, however, studied control strategies assuming unlimited resources. Here, we depart from this unrealistic assumption and consider the effect of limited resources on the effectiveness of control. We show that, even for scarce resources, percolation can be controlled with an efficient intervention strategy. We derive such an efficient strategy and study its implications, revealing a discontinuous transition as an unintended side effect of optimal control.

Large angle magnetic suspension test fixture

NASA Technical Reports Server (NTRS)

Britcher, Colin P. (Principal Investigator); Huang, Jen-Kuang (Principal Investigator)

1996-01-01

Good progress is being made in several major areas. These include eddy current modelling and analysis, design optimization methods, wind tunnel Magnetic Suspension and Balance Systems (MSBS), payload pointing and vibration isolation systems, and system identification. In addition, another successful International Symposium has been completed, with the Proceedings being printed at the time of writing. These activities continue current work under this Grant and extend previous work on magnetic suspension systems and devices in the Guidance and Control Branch and will permit the demonstration of several new developments in the field of magnetic suspension technology.

Energy-gap spectroscopy of superconductors using a tunneling microscope

NASA Technical Reports Server (NTRS)

Le Duc, H. G.; Kaiser, W. J.; Stern, J. A.

1987-01-01

A unique scanning tunneling microscope (STM) system has been developed for spectroscopy of the superconducting energy gap. High-resolution control of tunnel current and voltage allows for measurement of superconducting properties at tunnel resistance levels 100-1000 greater than that achieved in prior work. The previously used STM methods for superconductor spectroscopy are compared to those developed for the work reported here. Superconducting energy-gap spectra are reported for three superconductors, Pb, PbBi, and NbN, over a range of tunnel resistance. The measured spectra are compared directly to theory.

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

Needham, D.; Spearman, A.

This paper describes the design and development of a modular gas control installation which is completely buried, except for a small instrument housing and vent pipe. Buried installations controlling gas pressure have many advantages:- no unsightly or costly housings, protection from damage by vehicles or vandals, no problems of acquisition of sites in built-up areas, no need to divert mains to alternative locations, reduced noise, and easier planning permission associated with environmental aspects. It had not previously been possible to realise these advantages with conventional equipment but a novel concept has emerged which solves the problems and provides additional benefits.more » All the working components of a single stream governor station are installed under a 600mm diameter surface access cover. The essential control elements are contained in a lightweight cartridge which can be exchanged in about 15 minutes by two men working from ground level.« less

Multidimensional quantum entanglement with large-scale integrated optics.

PubMed

Wang, Jianwei; Paesani, Stefano; Ding, Yunhong; Santagati, Raffaele; Skrzypczyk, Paul; Salavrakos, Alexia; Tura, Jordi; Augusiak, Remigiusz; Mančinska, Laura; Bacco, Davide; Bonneau, Damien; Silverstone, Joshua W; Gong, Qihuang; Acín, Antonio; Rottwitt, Karsten; Oxenløwe, Leif K; O'Brien, Jeremy L; Laing, Anthony; Thompson, Mark G

2018-04-20

The ability to control multidimensional quantum systems is central to the development of advanced quantum technologies. We demonstrate a multidimensional integrated quantum photonic platform able to generate, control, and analyze high-dimensional entanglement. A programmable bipartite entangled system is realized with dimensions up to 15 × 15 on a large-scale silicon photonics quantum circuit. The device integrates more than 550 photonic components on a single chip, including 16 identical photon-pair sources. We verify the high precision, generality, and controllability of our multidimensional technology, and further exploit these abilities to demonstrate previously unexplored quantum applications, such as quantum randomness expansion and self-testing on multidimensional states. Our work provides an experimental platform for the development of multidimensional quantum technologies. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Considerations for conducting epidemiologic case-control studies of cancer in developing countries.

PubMed

Brinton, L A; Herrero, R; Brenes, M; Montalván, P; de la Guardia, M E; Avila, A; Domínguez, I L; Basurto, E; Reeves, W C

1991-01-01

The challenges involved in conducting epidemiologic studies of cancer in developing countries can be and often are unique. This article reports on our experience in performing a case-control study of invasive cervical cancer in four Latin American countries (Columbia, Costa Rica, Mexico, and Panama), the summary medical results of which have been published in a previous issue of this journal (1). The study involved a number of principal activities--mainly selecting, conducting interviews with, and obtaining appropriate biologic specimens from 759 cervical cancer patients, 1,467 matched female controls, and 689 male sex partners of monogamous female subjects. This presentation provides an overview of the planning and methods used to select the subjects, conduct the survey work, and obtain complete and effectively unbiased data. It also points out some of the important advantages and disadvantages of working in developing areas similar to those serving as locales for this study.

Are planning, working memory, and inhibition associated with individual differences in preschool ADHD symptoms?

PubMed

Sonuga-Barke, Edmund J S; Dalen, Lindy; Daley, Dave; Remington, Bob

2002-01-01

The association between executive function (EF; planning, working memory, and inhibition) and individual differences in symptoms of attention deficit hyperactivity disorder (ADHD) was explored in a sample of preschool children. One hundred sixty children (between the ages of 3 years, 0 months and 5 years, 6 months), selected so as to oversample high ADHD scorers, performed 3 tasks previously shown to measure planning (Tower of London), working memory (Noisy Book) and inhibition ("Puppet Says..."). EF measures were reliable (kappa > .77) and were correlated with IQ (rs > .38) and age (rs > .59). Once IQ and age were controlled, planning and working memory (r = .41) were correlated. Planning and working memory were not correlated with inhibition (rs < .20). There was no association between ADHD and working memory or planning (rs < .12). There was a significant negative association between ADHD and conduct problems and inhibition (r = -.30 and r = -.25, respectively). Only the link with ADHD persisted after the effects of other factors were controlled for in a multiple regression. Specific deficits in inhibitory control rather than general EF deficits are associated with ADHD in the preschool period. This association is linear in nature, supporting the idea that ADHD is better seen as a continuum rather than a discrete category. This association provides evidence for Barkley's (1997) view that ADHD is underpinned by inhibitory deficits in the preschool period.

Working on Sundays–effects on safety, health, and work-life balance.

PubMed

Wirtz, Anna; Nachreiner, Friedhelm; Rolfes, Katharina

2011-05-01

Several attributes of the work schedule can increase the risk of occupational injuries and accidents, health impairments, and reduced social participation. Although previous studies mainly focused on the effects of shiftwork and long working hours on employee health and safety, there is little evidence of a potential negative impact of working Sundays on the incidence of occupational accidents, health impairments, and work-life balance. A representative sample of employed workers in 31 member and associated states of the European Union (n = 23,934) served as the database for a cross-sectional analysis. The sample was collected via face-to-face interviews in the year 2005. The association of the risks of occupational accidents, health impairments, and decreases in work-life balance with working Sundays was calculated using logistic regression models, controlling for potential confounders, such as shiftwork, workload, and demographic characteristics. The results indicated that working one or more Sundays/month was associated with increase both in the risk of reporting one or more health impairments (odds ratio [OR]: 1.17, 95% confidence interval [CI]: 1.06-1.29) and poorer work-life balance (OR: 1.15, 95% CI: 1.02-1.28). These effects remained after controlling for potentially confounding factors, such as other work schedule attributes, intensity of physical and mental workload, and individual characteristics. Furthermore, working Sundays was also related to increased risk of occupational accidents within the last year (OR: 1.34, 95% CI: 1.03-1.73). Controlling again for individual, workload, and working-time characteristics, a significant association with accident risk, however, remained only in work sectors with low a priori risk of occupational accidents (OR: 1.40, 95% CI: 1.02-1.91), although the increased risk could be observed for both medium and high a priori risk sectors working Sundays (without controlling for additional confounders). The results thus indicate that the detrimental effects of working Sundays on safety, health, and social well-being should be taken into account when designing work schedules. The potential hazards to employees' safety, health, and work-life balance, in particular, should be considered in discussions concerning extending work on Sundays in certain sectors, e.g., retail.

Local cluster of germ cell cancer in a cohort of male automotive workers in Germany not explained by previous or concurrent activities and exposures in farming and forestry.

PubMed

Schmeisser, N; Behrens, T; Mester, B; Gottlieb, A; Langner, I; Ahrens, W

2011-02-01

To examine whether exposures or activities in farming, forestry and related occupations explain the excess incidence of germ cell cancer (GCC) observed among male employees in one of the six car-manufacturing plants that is located in a geographic area where farming is frequent. A cohort based case-control study was conducted among workers in six car-manufacturing plants located in areas with different industrial structure. The study involved 188 cases of germ cell cancer identified through active retrieval in 38 hospitals and 1000 controls, drawn from administrative accounting files, individually matched by year of birth (± 2 years). Information regarding tasks and exposures and potential confounding variables were obtained by face-to-face or telephone interviews. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using a conditional logistic regression model adjusted for cryptorchidism and other potential confounders. In this case-control study 5.3% of cases and 6.3% of controls ever worked in agriculture or livestock farming. No increased risks were observed for working in agriculture (OR=0.8 95% CI: 0.4-1.6), livestock farming (OR=0.8 95% CI: 0.4-1.6) or for exposure to pesticides (OR=0.7 95% CI: 0.3-1.7), for exposure to fertilizers (OR=0.8 95% CI: 0.4-1.8) and disinfectants (OR=1.0 95% CI: 0.3-2.8). There were no statistically significant increases in risk associated with ever exposure to salt based wood protection agents (OR=2.3 95% CI: 0.6-9.1), working with plywood (OR=1.4 95% CI: 0.6-3.2), coated wood (OR=1.4 95% CI: 0.5-3.9) or working in forestry (OR=1.7 95% CI: 0.5-6.4). Lagging of exposures did not alter the results. The observed excess incidence in the cohort of automotive workers can be hardly explained by previous or concurrent work in farming or forestry. Because of the small numbers of subjects ever employed in farming the statistical power in assessing associations between agricultural work and agricultural exposures was limited and does not allow final conclusions about the association of farming related exposures and GCC risk. Copyright © 2010 Elsevier Ltd. All rights reserved.

Nursing home work practices and nursing assistants' job satisfaction.

PubMed

Bishop, Christine E; Squillace, Marie R; Meagher, Jennifer; Anderson, Wayne L; Wiener, Joshua M

2009-10-01

To estimate the impact of nursing home work practices, specifically compensation and working conditions, on job satisfaction of nursing assistants employed in nursing homes. Data are from the 2004 National Nursing Assistant Survey, responses by the nursing assistants' employers to the 2004 National Nursing Home Survey, and county-level data from the Area Resource File. Multinomial logistic regression was used to estimate effects of compensation and working conditions on nursing assistants' overall job satisfaction, controlling for personal characteristics and local labor market characteristics. Wages, benefits, and job demands, measured by the ratio of nursing assistant hours per resident day, were associated with job satisfaction. Consistent with previous studies, job satisfaction was greater when nursing assistants felt respected and valued by their employers and had good relationships with supervisors. Nursing assistants were more satisfied when they had enough time to complete their work, when their work was challenging, when they were not subject to mandatory overtime, and where food was not delivered to residents on trays. This is the first investigation of nursing assistant job satisfaction using a nationally representative sample of nursing assistants matched to information about their employing nursing homes. The findings corroborate results of previous studies in showing that compensation and working conditions that provide respect, good relationships with supervisors, and better staffing levels are important to nursing assistant job satisfaction.

Trifocal Tensor-Based Adaptive Visual Trajectory Tracking Control of Mobile Robots.

PubMed

Chen, Jian; Jia, Bingxi; Zhang, Kaixiang

2017-11-01

In this paper, a trifocal tensor-based approach is proposed for the visual trajectory tracking task of a nonholonomic mobile robot equipped with a roughly installed monocular camera. The desired trajectory is expressed by a set of prerecorded images, and the robot is regulated to track the desired trajectory using visual feedback. Trifocal tensor is exploited to obtain the orientation and scaled position information used in the control system, and it works for general scenes owing to the generality of trifocal tensor. In the previous works, the start, current, and final images are required to share enough visual information to estimate the trifocal tensor. However, this requirement can be easily violated for perspective cameras with limited field of view. In this paper, key frame strategy is proposed to loosen this requirement, extending the workspace of the visual servo system. Considering the unknown depth and extrinsic parameters (installing position of the camera), an adaptive controller is developed based on Lyapunov methods. The proposed control strategy works for almost all practical circumstances, including both trajectory tracking and pose regulation tasks. Simulations are made based on the virtual experimentation platform (V-REP) to evaluate the effectiveness of the proposed approach.

Excessive work and risk of haemorrhagic stroke: a nationwide case-control study.

PubMed

Kim, Beom Joon; Lee, Seung-Hoon; Ryu, Wi-Sun; Kim, Chi Kyung; Chung, Jong-Won; Kim, Dohoung; Park, Hong-Kyun; Bae, Hee-Joon; Park, Byung-Joo; Yoon, Byung-Woo

2013-10-01

Adverse effect of excessive work on health has been suggested previously, but it was not documented in cerebrovascular diseases. The authors investigated whether excessive working conditions would associate with increased risk of haemorrhagic stroke. A nationwide matched case-control study database, which contains 940 cases of incident haemorrhagic stroke (498 intracerebral haemorrhages and 442 sub-arachnoid haemorrhages) with 1880 gender- and age- (± 5-year) matched controls, was analysed. Work-related information based on the regular job situation, including type of occupation, regular working time, duration of strenuous activity during regular work and shift work, was gathered through face-to-face interviews. Conditional logistic regression analyses were used for the multivariable analyses. Compared with white-collar workers, blue-collar workers had a higher risk for haemorrhagic stroke (odds ratio, 1.33 [95% confidence interval, 1.06-1.66]). Longer regular working time was associated with increased risk of haemorrhagic stroke [odds ratio, 1.38 (95% confidence interval, 1.05-1.81) for 8-12 h/day; odds ratio, 1.95 (95% confidence interval, 1.33-2.86) for ≥ 13 h/day; compared with ≤ 4 h/day]. Exposure to ≥ 8 h/week of strenuous activity also associated haemorrhagic stroke risk [odds ratio, 1.61 (95% confidence interval, 1.26-2.05); compared with no strenuous activity]. Shift work was not associated with haemorrhagic stroke (P = 0.98). Positive associations between working condition indices and haemorrhagic stroke risk were consistent regardless of haemorrhagic stroke sub-types and current employment status. Blue-collar occupation, longer regular working time and extended duration of strenuous activity during work may relate to an increased risk of haemorrhagic stroke. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

A novel simplified model for torsional vibration analysis of a series-parallel hybrid electric vehicle

NASA Astrophysics Data System (ADS)

Tang, Xiaolin; Yang, Wei; Hu, Xiaosong; Zhang, Dejiu

2017-02-01

In this study, based on our previous work, a novel simplified torsional vibration dynamic model is established to study the torsional vibration characteristics of a compound planetary hybrid propulsion system. The main frequencies of the hybrid driveline are determined. In contrast to vibration characteristics of the previous 16-degree of freedom model, the simplified model can be used to accurately describe the low-frequency vibration property of this hybrid powertrain. This study provides a basis for further vibration control of the hybrid powertrain during the process of engine start/stop.

The Virtual Tablet: Virtual Reality as a Control System

NASA Technical Reports Server (NTRS)

Chronister, Andrew

2016-01-01

In the field of human-computer interaction, Augmented Reality (AR) and Virtual Reality (VR) have been rapidly growing areas of interest and concerted development effort thanks to both private and public research. At NASA, a number of groups have explored the possibilities afforded by AR and VR technology, among which is the IT Advanced Concepts Lab (ITACL). Within ITACL, the AVR (Augmented/Virtual Reality) Lab focuses on VR technology specifically for its use in command and control. Previous work in the AVR lab includes the Natural User Interface (NUI) project and the Virtual Control Panel (VCP) project, which created virtual three-dimensional interfaces that users could interact with while wearing a VR headset thanks to body- and hand-tracking technology. The Virtual Tablet (VT) project attempts to improve on these previous efforts by incorporating a physical surrogate which is mirrored in the virtual environment, mitigating issues with difficulty of visually determining the interface location and lack of tactile feedback discovered in the development of previous efforts. The physical surrogate takes the form of a handheld sheet of acrylic glass with several infrared-range reflective markers and a sensor package attached. Using the sensor package to track orientation and a motion-capture system to track the marker positions, a model of the surrogate is placed in the virtual environment at a position which corresponds with the real-world location relative to the user's VR Head Mounted Display (HMD). A set of control mechanisms is then projected onto the surface of the surrogate such that to the user, immersed in VR, the control interface appears to be attached to the object they are holding. The VT project was taken from an early stage where the sensor package, motion-capture system, and physical surrogate had been constructed or tested individually but not yet combined or incorporated into the virtual environment. My contribution was to combine the pieces of hardware, write software to incorporate each piece of position or orientation data into a coherent description of the object's location in space, place the virtual analogue accordingly, and project the control interface onto it, resulting in a functioning object which has both a physical and a virtual presence. Additionally, the virtual environment was enhanced with two live video feeds from cameras mounted on the robotic device being used as an example target of the virtual interface. The working VT allows users to naturally interact with a control interface with little to no training and without the issues found in previous efforts.

Memorial familiarity remains intact for pictures but not for words in patients with amnestic mild cognitive impairment.

PubMed

Embree, Lindsay M; Budson, Andrew E; Ally, Brandon A

2012-07-01

Understanding how memory breaks down in the earliest stages of Alzheimer's disease (AD) process has significant implications, both clinically and with respect to intervention development. Previous work has highlighted a robust picture superiority effect in patients with amnestic mild cognitive impairment (aMCI). However, it remains unclear as to how pictures improve memory compared to words in this patient population. In the current study, we utilized receiver operating characteristic (ROC) curves to obtain estimates of familiarity and recollection for pictures and words in patients with aMCI and healthy older controls. Analysis of accuracy shows that even when performance is matched between pictures and words in the healthy control group, patients with aMCI continue to show a significant picture superiority effect. The results of the ROC analysis showed that patients demonstrated significantly impaired recollection and familiarity for words compared controls. In contrast, patients with aMCI demonstrated impaired recollection, but intact familiarity for pictures, compared to controls. Based on previous work from our lab, we speculate that patients can utilize the rich conceptual information provided by pictures to enhance familiarity, and perceptual information may allow for post-retrieval monitoring or verification of the enhanced sense of familiarity. Alternatively, the combination of enhanced conceptual and perceptual fluency of the test item might drive a stronger or more robust sense of familiarity that can be accurately attributed to a studied item. Copyright © 2012 Elsevier Ltd. All rights reserved.

Object positioning in storages of robotized workcells using LabVIEW Vision

NASA Astrophysics Data System (ADS)

Hryniewicz, P.; Banaś, W.; Sękala, A.; Gwiazda, A.; Foit, K.; Kost, G.

2015-11-01

During the manufacturing process, each performed task is previously developed and adapted to the conditions and the possibilities of the manufacturing plant. The production process is supervised by a team of specialists because any downtime causes great loss of time and hence financial loss. Sensors used in industry for tracking and supervision various stages of a production process make it much easier to maintain it continuous. One of groups of sensors used in industrial applications are non-contact sensors. This group includes: light barriers, optical sensors, rangefinders, vision systems, and ultrasonic sensors. Through to the rapid development of electronics the vision systems were widespread as the most flexible type of non-contact sensors. These systems consist of cameras, devices for data acquisition, devices for data analysis and specialized software. Vision systems work well as sensors that control the production process itself as well as the sensors that control the product quality level. The LabVIEW program as well as the LabVIEW Vision and LabVIEW Builder represent the application that enables program the informatics system intended to process and product quality control. The paper presents elaborated application for positioning elements in a robotized workcell. Basing on geometric parameters of manipulated object or on the basis of previously developed graphical pattern it is possible to determine the position of particular manipulated elements. This application could work in an automatic mode and in real time cooperating with the robot control system. It allows making the workcell functioning more autonomous.

Memorial familiarity remains intact for pictures but not for words in patients with amnestic mild cognitive impairment

PubMed Central

Embree, Lindsay M.; Budson, Andrew E.; Ally, Brandon A.

2012-01-01

Understanding how memory breaks down in the earliest stages of the Alzheimer’s disease (AD) process has significant implications, both clinically and with respect to intervention development. Previous work has highlighted a robust picture superiority effect in patients with amnestic mild cognitive impairment (aMCI). However, it remains unclear as to how pictures improve memory compared to words in this patient population. In the current study, we utilized receiver operating characteristic (ROC) curves to obtain estimates of familiarity and recollection for pictures and words in patients with aMCI and healthy older controls. Analysis of accuracy shows that even when performance is matched between pictures and words in the healthy control group, patients with aMCI continue to show a significant picture superiority effect. The results of the ROC analysis showed that patients demonstrated significantly impaired recollection and familiarity for words compared controls. In contrast, patients with aMCI demonstrated impaired recollection, but intact familiarity for pictures, compared to controls. Based on previous work from our lab, we speculate that patients can utilize the rich conceptual information provided by pictures to enhance familiarity, and perceptual information may allow for post-retrieval monitoring or verification of the enhanced sense of familiarity. Alternatively, the combination of enhanced conceptual and perceptual fluency of the test item might drive a stronger or more robust sense of familiarity that can be accurately attributed to a studied item. PMID:22705441

Lateral vibration control of a precise machine using magneto-rheological mounts featuring multiple directional damping effect

NASA Astrophysics Data System (ADS)

Kim, Hyung Tae; Jeong, An Mok; Kim, Hyo Young; An, Jong Wook; Kim, Cheol Ho; Jin, Kyung Chan; Choi, Seung-Bok

2018-03-01

In a previous work, magneto-rheological (MR) dampers were originally designed and implemented for reducing the vertical low-frequency vibration occurring in precise semi-conductor manufacturing equipment. To reduce the vibrations, an isolator levitated the manufacturing machine from the floor using pneumatic pressure which cut off the external vibration, while the MR damper was used to decrease the transient response of the isolator. However, it has been found that the MR damper also provides a damping effect on the lateral vibration induced by the high-speed plane motions. Therefore, in this work both vertical and lateral vibrations are controlled using the yield and shear stresses of the lateral directions generated from the MR fluids by applying a magnetic field. After deriving a vibration control model, an overall control logic is formulated considering both vertical and lateral vibrations. In this control strategy, a feedback loop associated with the laser sensor is used for vertical vibration control, while a feed-forward loop with the motion information is used for lateral vibration control. The experimental results show that the proposed concept is highly effective for lateral vibration control using the damping effect on multiple directions.

Challenging Cognitive Control by Mirrored Stimuli in Working Memory Matching

PubMed Central

Wirth, Maria; Gaschler, Robert

2017-01-01

Cognitive conflict has often been investigated by placing automatic processing originating from learned associations in competition with instructed task demands. Here we explore whether mirror generalization as a congenital mechanism can be employed to create cognitive conflict. Past research suggests that the visual system automatically generates an invariant representation of visual objects and their mirrored counterparts (i.e., mirror generalization), and especially so for lateral reversals (e.g., a cup seen from the left side vs. right side). Prior work suggests that mirror generalization can be reduced or even overcome by learning (i.e., for those visual objects for which it is not appropriate, such as letters d and b). We, therefore, minimized prior practice on resolving conflicts involving mirror generalization by using kanji stimuli as non-verbal and unfamiliar material. In a 1-back task, participants had to check a stream of kanji stimuli for identical repetitions and avoid miss-categorizing mirror reversed stimuli as exact repetitions. Consistent with previous work, lateral reversals led to profound slowing of reaction times and lower accuracy in Experiment 1. Yet, different from previous reports suggesting that lateral reversals lead to stronger conflict, similar slowing for vertical and horizontal mirror transformations was observed in Experiment 2. Taken together, the results suggest that transformations of visual stimuli can be employed to challenge cognitive control in the 1-back task. PMID:28503160

Neuropsychological Profiles on the WAIS-IV of Adults With ADHD.

PubMed

Theiling, Johanna; Petermann, Franz

2016-11-01

The aim of the study was to investigate the pattern of neuropsychological profiles on the Wechsler Adult Intelligence Scale-IV (WAIS-IV) for adults With ADHD relative to randomly matched controls and to assess overall intellectual ability discrepancies of the Full Scale Intelligence Quotient (FSIQ) and the General Ability Index (GAI). In all, 116 adults With ADHD and 116 controls between 16 and 71 years were assessed. Relative to controls, adults With ADHD show significant decrements in subtests with working memory and processing speed demands with moderate to large effect sizes and a higher GAI in comparison with the FSIQ. This suggests first that deficits identified with previous WAIS versions are robust in adults With ADHD and remain deficient when assessed with the WAIS-IV; second that the WAIS-IV reliably differentiates between patients and controls; and third that a reduction of the FSIQ is most likely due to a decrement in working memory and processing speed abilities. The findings have essential implications for the diagnostic process. © The Author(s) 2014.

Online Recorded Data-Based Composite Neural Control of Strict-Feedback Systems With Application to Hypersonic Flight Dynamics.

PubMed

Xu, Bin; Yang, Daipeng; Shi, Zhongke; Pan, Yongping; Chen, Badong; Sun, Fuchun

2017-09-25

This paper investigates the online recorded data-based composite neural control of uncertain strict-feedback systems using the backstepping framework. In each step of the virtual control design, neural network (NN) is employed for uncertainty approximation. In previous works, most designs are directly toward system stability ignoring the fact how the NN is working as an approximator. In this paper, to enhance the learning ability, a novel prediction error signal is constructed to provide additional correction information for NN weight update using online recorded data. In this way, the neural approximation precision is highly improved, and the convergence speed can be faster. Furthermore, the sliding mode differentiator is employed to approximate the derivative of the virtual control signal, and thus, the complex analysis of the backstepping design can be avoided. The closed-loop stability is rigorously established, and the boundedness of the tracking error can be guaranteed. Through simulation of hypersonic flight dynamics, the proposed approach exhibits better tracking performance.

Associations of self estimated workloads with musculoskeletal symptoms among hospital nurses

PubMed Central

Ando, S.; Ono, Y.; Shimaoka, M.; Hiruta, S.; Hattori, Y.; Hori, F.; Takeuchi, Y.

2000-01-01

OBJECTIVES—To investigate the prevalence of neck, shoulder, and arm pain (NSAP) as well as low back pain (LBP) among hospital nurses, and to examine the association of work tasks and self estimated risk factors with NSAP and LBP.
METHODS—A cross sectional study was carried out in a national university hospital in Japan. Full time registered nurses in the wards (n=314) were selected for analysis. The questionnaire was composed of items on demographic conditions, severity of workloads in actual tasks, self estimated risk factors for fatigue, and musculoskeletal pain in the previous month. Rate ratios (RRs) and 95% confidence intervals (95% CIs) were calculated by the Cox's proportional hazards model to study the association of pain with variables related to work and demographic conditions.
RESULTS—The prevalences of low back, shoulder, neck, and arm pain in the previous month were 54.7%, 42.8%, 31.3%, and 18.6%, respectively. The prevalence of musculoskeletal symptoms among hospital nurses was higher than in previous studies. In the Cox's models for LBP and NSAP, there were no significant associations between musculoskeletal pain and the items related to work and demographic conditions. The RRs for LBP tended to be relatively higher for "accepting emergency patients" and some actual tasks. Some items of self estimated risk factors for fatigue tended to have relatively higher RRs for LBP and NSAP.
CONCLUSIONS—It was suggested that musculoskeletal pain among hospital nurses may have associations with some actual tasks and items related to work postures, work control, and work organisation. Further studies, however, are necessary, as clear evidence of this potential association was not shown in the study.


Keywords: workloads; musculoskeletal pain; nurses PMID:10810105

Cognitive control in context: working memory capacity and proactive control.

PubMed

Redick, Thomas S

2014-01-01

Working memory is important for maintaining critical information in an active state to guide future behavior. The executive-attention theory of working memory capacity (WMC; Engle & Kane, 2004) argues that goal maintenance is important for response selection when stimuli are associated with competing responses. Braver, Burgess, and Gray (2007) have labeled this type of preparatory activity proactive control. Previous WMC studies have not allowed individuals to use goal information to prepare a specific response in advance of the stimulus. The current experiment used different versions of a cue-probe task to examine the relationship between individual differences in WMC and proactive control. Across three versions of the AX version of the Continuous Performance Test, the proportion of targets was manipulated to affect both the predictive validity of the A cue and the prepotency of the target response to X probes. The results indicated that the high-WMC individuals used the cue information to prepare responses in advance only when a specific probe was likely to occur. In contrast, the performance of the low-WMC individuals was less dependent upon the cue and more contingent upon overall response frequencies. The results indicate that individual differences in WMC are related to proactive control and anticipation, and important for translating cognition into action. © 2013 Elsevier B.V. All rights reserved.

Physical and psychosocial working conditions as explanations for occupational class inequalities in self-rated health.

PubMed

Kaikkonen, Risto; Rahkonen, Ossi; Lallukka, Tea; Lahelma, Eero

2009-10-01

Socio-economic health inequalities are well documented, but efforts to explain health inequalities are less. However, previous studies suggest that working conditions provide potential explanations for inequalities in health. Cross-sectional questionnaire survey data, collected from municipal employees of the City of Helsinki, aged 40-60 years (n = 8960, response rate 67%) in 2000-02, were examined using binomial regression analysis. Socio-economic position was measured by six occupational social classes ranging from top managers to manual workers, and the outcome was self-rated health (SRH). Key physical and psychosocial working conditions and work arrangements were included as explanatory factors for inequalities in health. Occupational class inequalities in SRH were clear among women [prevalence ratio (PR) 1.89, 95% confidence interval (CI) 1.54-2.32] and men (PR 1.78, 95% CI 1.40-2.25). Heavy physical workload explained a half of the health inequalities among women and almost one-third among men. Physical and chemical exposures at work explained one-fifth of the health inequalities among women and a half among men. Job control explained 24% of the men's and 40% of women's inequalities, whereas job demands widened the inequalities by 13-14%. The effects of shift work and working hours were negligible. In the fully adjusted model, 60% of the women's and 32% of the men's inequalities in SRH were explained. Physical working conditions explained a large part and job control, a somewhat smaller part of socio-economic inequalities in SRH. Improving physical working conditions and increasing job control provide potential routes to reduced inequalities in health among employees.

Associations Between Physical Fitness Indices and Working Memory in Breast Cancer Survivors and Age-Matched Controls

PubMed Central

Mackenzie, Michael J.; Zuniga, Krystle E.; Raine, Lauren B.; Awick, Elizabeth A.; Hillman, Charles H.; Kramer, Arthur F.

2016-01-01

Abstract Background: This study examined the effects of cardiorespiratory fitness, heart rate recovery, and physical activity on working memory in breast cancer survivors and age-matched controls. Method: Using a case-control design, 32 women who had received a breast cancer diagnosis and completed primary treatment within the past 36-months (11 radiation only; 21 chemotherapy) and 30 age-matched women with no previous cancer diagnosis completed a n-back continuous performance task commonly used as an assessment of working memory. In addition, cardiorespiratory fitness and heart rate recovery were measured during a submaximal graded exercise test and physical activity was measured using 7-days of accelerometer monitoring. Results: Breast cancer survivors who had received chemotherapy had poorer heart rate recovery (p = .010) and engaged in less physical activity than women who had received radiation only (p = .004) or non-cancer controls (p = .029). Cancer treatment (radiation; chemotherapy) predicted differences in reaction times on the 1-back working memory task (p = .029). However, more rapid heart rate recovery predicted shorter reaction times on the 1-back task in the age-matched control group (p = .002). All participants with greater cardiorespiratory fitness displayed greater accuracy independent of disease status on the 1-back task (p = .017). No significant group differences in reaction times were observed for 2-back target trials between breast cancer survivors and controls. However, greater total physical activity predicted shorter reaction times in breast cancer survivors (radiation, chemotherapy) on the 2-back task (p = .014). In addition, all participants who exhibited more rapid heart rate recovery demonstrated better greater accuracy regardless of disease status (p = .013). Conclusion: These findings support differences in physical activty participation, heart rate recovery, and 1- and 2-back working memory reaction times between breast cancer survivors and age-matched controls. Greater cardiorespiratory fitness, heart rate recovery, and physical activity were positively associated with better working memory performance across conditions. PMID:26418463

Psychoeducation to facilitate return to work in individuals on sick leave and at risk of having a mental disorder: protocol of a randomised controlled trial.

PubMed

Pedersen, Pernille; Søgaard, Hans Jørgen; Yde, Bjarne Frostholm; Labriola, Merete; Nohr, Ellen A; Jensen, Chris

2014-12-17

Sickness absence due to poor mental health is a common problem in many Western countries. To facilitate return to work, it may be important to identify individuals on sick leave and at risk of having a mental disorder and subsequently to offer appropriate treatment. Psychoeducation alone has not previously been used as a return to work intervention, but may be a promising tool to facilitate return to work. Therefore, the aim of the study is to evaluate the effectiveness of psychoeducation designed specifically to facilitate return to work for individuals on sick leave and at risk of having a mental disorder. The psychoeducation was a supplement to the various standard offers provided by the job centres. The study is a randomised controlled trial, in which individuals on sick leave either receive psychoeducation and standard case management or standard case management alone. Participants were individuals with mental health symptoms, who had been on sick leave from part-time or full-time work or unemployment for about 4-8 weeks. The psychoeducational intervention was group-based and the course consisted of 2 hour sessions once a week for 6 weeks. The course was given by psychiatric nurses, a psychologist, a social worker, a physiotherapist and a person who had previously been on sick leave due to mental health problems. The sessions focused on stress and work life, and the purpose was to provide individuals on sick leave the skills to understand and improve their mental functioning.The primary outcome is the duration of sickness absence measured by register data. Secondary outcomes include psychological symptoms, mental health-related quality of life, and locus of control. These outcomes are measured by questionnaires at the start of the intervention and at 3 and 6 months follow-up. On the basis of this trial, the effect of psychoeducation for individuals on sick leave and at risk of having a mental disorder will be studied. The results will contribute to the continuing research on sickness absence and mental health. It will primarily show whether psychoeducation can lead to faster and sustainable return to work. Clinical Trial.gov NCT01637363. Registered 6 July 2012.

Multi-Point Combustion System: Final Report

NASA Technical Reports Server (NTRS)

Goeke, Jerry; Pack, Spencer; Zink, Gregory; Ryon, Jason

2014-01-01

A low-NOx emission combustor concept has been developed for NASA's Environmentally Responsible Aircraft (ERA) program to meet N+2 emissions goals for a 70,000 lb thrust engine application. These goals include 75 percent reduction of LTO NOx from CAEP6 standards without increasing CO, UHC, or smoke from that of current state of the art. An additional key factor in this work is to improve lean combustion stability over that of previous work performed on similar technology in the early 2000s. The purpose of this paper is to present the final report for the NASA contract. This work included the design, analysis, and test of a multi-point combustion system. All design work was based on the results of Computational Fluid Dynamics modeling with the end results tested on a medium pressure combustion rig at the UC and a medium pressure combustion rig at GRC. The theories behind the designs, results of analysis, and experimental test data will be discussed in this report. The combustion system consists of five radially staged rows of injectors, where ten small scale injectors are used in place of a single traditional nozzle. Major accomplishments of the current work include the design of a Multipoint Lean Direct Injection (MLDI) array and associated air blast and pilot fuel injectors, which is expected to meet or exceed the goal of a 75 percent reduction in LTO NOx from CAEP6 standards. This design incorporates a reduced number of injectors over previous multipoint designs, simplified and lightweight components, and a very compact combustor section. Additional outcomes of the program are validation that the design of these combustion systems can be aided by the use of Computational Fluid Dynamics to predict and reduce emissions. Furthermore, the staging of fuel through the individually controlled radially staged injector rows successfully demonstrated improved low power operability as well as improvements in emissions over previous multipoint designs. Additional comparison between Jet- A fuel and a hydrotreated biofuel is made to determine viability of the technology for use with alternative fuels. Finally, the operability of the array and associated nozzles proved to be very stable without requiring additional active or passive control systems. A number of publications have been publish

Work activity in the process of recovery - an interpretive phenomenological analysis of the experiences of people with a schizophrenia spectrum diagnosis.

PubMed

Pańczak, Anna; Pietkiewicz, Igor

2016-01-01

Having the opportunity to work has been found meaningful for individuals suffering from severe mental illness, in order to boost their self-esteem, provide a sense of control over their lives and of belonging to a community. There are no studies in Polish literature on the process of recovery from schizophrenia with reference to work activity. The objective of this research was to explore personal experiences of people employed in Vocational Development Centers. Eight semi-structured interviews were conducted with adult patients. Their transcripts were subject to interpretative phenomenological analysis (IPA). Having the opportunity to work was significant for participants because it mobilized them and encouraged self-care. G oing to work helped them overcome social isolation by meeting people with similar difficulties and those who did not suffer from mental illness. Financial gratification enables a sense of independence and the ability to develop skills to plan and control their budget. This study finds that patients who lost their jobs due to mental illness should be encouraged to utilize rehabilitation institutions to help them undertake work activity and use previously acquired qualifications or develop new skills. Access to appropriate psychological support should be provided during vocation reorientation and adaptation into new work environments. This helps patients regain a sense of control and purpose, and cope with losing valued social roles. We also highlight the need for further studies into challenges in the workplace and the strategies patients use to cope with them.

Insulin and insulin-like growth factor-I (IGF-I) receptor phosphorylation in µ-calpain knockout mice

USDA-ARS?s Scientific Manuscript database

Numerous cellular processes are controlled by insulin and IGF-I signaling pathways. Due to previous work in our laboratories, we hypothesized that insulin (IR) and type 1 IGF-I (IGF-IR) receptor signaling is decreased due to increased protein tyrosine phosphatase 1B (PTP1B) activity. C57BL/6J mice...

The Effects of Grays Harbor Estuary Sediment on the Osmoregulatory Ability of Coho Salmon Smolts, Oncorhynchus Kisutch.

DTIC Science & Technology

1982-09-01

seawater for 24 hours ("seawater challenge"). These fish were able to osmoregulate as well as the control group, which was not exposed to sed- iment...what would be expected, based on previous work, and may be an artifact. There may be other fac- tors affecting the ability of fish to osmoregulate

Brief Report: Diminished Gaze Preference for Dynamic Social Interaction Scenes in Youth with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Shaffer, Rebecca C.; Pedapati, Ernest V.; Shic, Frederick; Gaietto, Kristina; Bowers, Katherine; Wink, Logan K.; Erickson, Craig A.

2017-01-01

In this study, we present an eye-tracking paradigm, adapted from previous work with toddlers, for assessing social-interaction looking preferences in youth ages 5-17 with ASD and typically-developing controls (TDC). Videos of children playing together (Social Scenes, SS) were presented side-by-side with animated geometric shapes (GS). Participants…

Understanding the Black-White Test Score Gap in the First Two Years of School. NBER Working Paper Series.

ERIC Educational Resources Information Center

Fryer, Roland G., Jr.; Levitt, Steven D.

In previous research, a substantial gap in test scores between white and black students persists, even after controlling for a wide range of observable characteristics. Using a data set made available by the National Center for Education Statistics, the Early Childhood Longitudinal Study, this paper demonstrates that in stark contrast to earlier…

Encouraging Survey Participation among Individuals Seeking HIV Prevention Services: Does a Community Identity Match Help or Hurt?

ERIC Educational Resources Information Center

Crowley, Jocelyn Elise; Roff, Brian H.; Lynch, Jeneve

2007-01-01

Understanding the behaviors and attitudes of at-risk populations is fundamental to controlling the spread of HIV, the virus that causes AIDS. The problem of nonresponse among these populations, however, plagues survey research designed to address these issues. Previous work undertaken to map out the dynamics of nonresponse--both noncontacts and…

The Skylab program - An overview

NASA Technical Reports Server (NTRS)

Disher, J. H.

1975-01-01

A brief survey is made of significant aspects of the Skylab missions, with emphasis on atmospheric control, electrical power, stabilization and attitude control, prevention of instrument contamination, habitability of the spacecraft, in-flight maintenance and repair, and crew training. Skylab, unlike previous manned spacecraft, had a two-gas atmosphere of oxygen and nitrogen. The station's 25-kW capability was the largest electrical system ever flown in space. Skylab was the first flight application of large control-moment gyroscopes for attitude control. The missions provided significant scientific data in the fields of solar physics, biomedicine, earth resources, and materials processing. Particularly important was the finding of no physical limitation to men's ability to work in space for long periods.

A curved piezo-structure model: implications on active structural acoustic control.

PubMed

Henry, J K; Clark, R L

1999-09-01

Current research in Active Structural Acoustic Control (ASAC) relies heavily upon accurately capturing the application physics associated with the structure being controlled. The application of ASAC to aircraft interior noise requires a greater understanding of the dynamics of the curved panels which compose the skin of an aircraft fuselage. This paper presents a model of a simply supported curved panel with attached piezoelectric transducers. The model is validated by comparison to previous work. Further, experimental results for a simply supported curved panel test structure are presented in support of the model. The curvature is shown to affect substantially the dynamics of the panel, the integration of transducers, and the bandwidth required for structural acoustic control.

A Study of Economical Incentives for Voltage Profile Control Method in Future Distribution Network

NASA Astrophysics Data System (ADS)

Tsuji, Takao; Sato, Noriyuki; Hashiguchi, Takuhei; Goda, Tadahiro; Tange, Seiji; Nomura, Toshio

In a future distribution network, it is difficult to maintain system voltage because a large number of distributed generators are introduced to the system. The authors have proposed “voltage profile control method” using power factor control of distributed generators in the previous work. However, the economical disbenefit is caused by the active power decrease when the power factor is controlled in order to increase the reactive power. Therefore, proper incentives must be given to the customers that corporate to the voltage profile control method. Thus, in this paper, we develop a new rules which can decide the economical incentives to the customers. The method is tested in one feeder distribution network model and its effectiveness is shown.

Balanced Cortical Microcircuitry for Spatial Working Memory Based on Corrective Feedback Control

PubMed Central

2014-01-01

A hallmark of working memory is the ability to maintain graded representations of both the spatial location and amplitude of a memorized stimulus. Previous work has identified a neural correlate of spatial working memory in the persistent maintenance of spatially specific patterns of neural activity. How such activity is maintained by neocortical circuits remains unknown. Traditional models of working memory maintain analog representations of either the spatial location or the amplitude of a stimulus, but not both. Furthermore, although most previous models require local excitation and lateral inhibition to maintain spatially localized persistent activity stably, the substrate for lateral inhibitory feedback pathways is unclear. Here, we suggest an alternative model for spatial working memory that is capable of maintaining analog representations of both the spatial location and amplitude of a stimulus, and that does not rely on long-range feedback inhibition. The model consists of a functionally columnar network of recurrently connected excitatory and inhibitory neural populations. When excitation and inhibition are balanced in strength but offset in time, drifts in activity trigger spatially specific negative feedback that corrects memory decay. The resulting networks can temporally integrate inputs at any spatial location, are robust against many commonly considered perturbations in network parameters, and, when implemented in a spiking model, generate irregular neural firing characteristic of that observed experimentally during persistent activity. This work suggests balanced excitatory–inhibitory memory circuits implementing corrective negative feedback as a substrate for spatial working memory. PMID:24828633

Numerical and Experimental Study on the Residual Stresses in the Nitrided Steel

NASA Astrophysics Data System (ADS)

Song, X.; Zhang, Zhi-Qian; Narayanaswamy, S.; Huang, Y. Z.; Zarinejad, M.

2016-09-01

In the present work, residual stresses distribution in the gas nitrided AISI 4140 sample has been studied using finite element (FE) simulation. The nitrogen concentration profile is obtained from the diffusion-controlled compound layer growth model, and nitrogen concentration controls the material volume change through phase transformation and lattice interstitials which results in residual stresses. Such model is validated through residual stress measurement technique—micro-ring-core method, which is applied to the nitriding process to obtain the residual stresses profiles in both the compound and diffusion layer. The numerical and experimental results are in good agreement with each other; they both indicate significant stress variation in the compound layer, which was not captured in previous research works due to the resolution limit of the traditional methods.

Identifying ADHD children using hemodynamic responses during a working memory task measured by functional near-infrared spectroscopy.

PubMed

Gu, Yue; Miao, Shuo; Han, Junxia; Liang, Zhenhu; Ouyang, Gaoxiang; Yang, Jian; Li, Xiaoli

2018-06-01

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting children and adults. Previous studies found that functional near-infrared spectroscopy (fNIRS) can reveal significant group differences in several brain regions between ADHD children and healthy controls during working memory tasks. This study aimed to use fNIRS activation patterns to identify ADHD children from healthy controls. FNIRS signals from 25 ADHD children and 25 healthy controls performing the n-back task were recorded; then, multivariate pattern analysis was used to discriminate ADHD individuals from healthy controls, and classification performance was evaluated for significance by the permutation test. The results showed that 86.0% ([Formula: see text]) of participants can be correctly classified in leave-one-out cross-validation. The most discriminative brain regions included the bilateral dorsolateral prefrontal cortex, inferior medial prefrontal cortex, right posterior prefrontal cortex, and right temporal cortex. This study demonstrated that, in a small sample, multivariate pattern analysis can effectively identify ADHD children from healthy controls based on fNIRS signals, which argues for the potential utility of fNIRS in future assessments.

Fuel composition effect on cathode airflow control in fuel cell gas turbine hybrid systems

NASA Astrophysics Data System (ADS)

Zhou, Nana; Zaccaria, Valentina; Tucker, David

2018-04-01

Cathode airflow regulation is considered an effective means for thermal management in solid oxide fuel cell gas turbine (SOFC-GT) hybrid system. However, performance and controllability are observed to vary significantly with different fuel compositions. Because a complete system characterization with any possible fuel composition is not feasible, the need arises for robust controllers. The sufficiency of robust control is dictated by the effective change of operating state given the new composition used. It is possible that controller response could become unstable without a change in the gains from one state to the other. In this paper, cathode airflow transients are analyzed in a SOFC-GT system using syngas as fuel composition, comparing with previous work which used humidified hydrogen. Transfer functions are developed to map the relationship between the airflow bypass and several key variables. The impact of fuel composition on system control is quantified by evaluating the difference between gains and poles in transfer functions. Significant variations in the gains and the poles, more than 20% in most cases, are found in turbine rotational speed and cathode airflow. The results of this work provide a guideline for the development of future control strategies to face fuel composition changes.

A case-crossover study of transient risk factors influence on occupational injuries: a study protocol based on a review of previous studies.

PubMed

Oesterlund, Anna H; Lander, Flemming; Lauritsen, Jens

2016-10-01

The occupational injury incident rate remains relatively high in the European Union. The case-crossover study gives a unique opportunity to study transient risk factors that normally would be very difficult to approach. Studies like this have been carried out in both America and Asia, but so far no relevant research has been conducted in Europe. Case-crossover studies of occupational injuries were collected from PubMed and Embase and read through. Previous experiences concerning method, exposure and outcome, time-related measurements and construction of the questionnaire were taken into account in the preparation of a pilot study. Consequently, experiences from the pilot study were used to design the study protocol. Approximately 2000 patients with an occupational injury will be recruited from the emergency departments in Herning and Odense, Denmark. A standardised questionnaire will be used to collect basic demographic data and information on eight transient risk factors. Based on previous studies and knowledge on occupational injuries the transient risk factors we chose to examine were: time pressure, performing a task with a different method/using unaccustomed technique, change in working surroundings, using a phone, disagreement, feeling ill, being distracted and using malfunctioning machinery/tools or work material. Exposure time 'just before the injury' will be compared with two control periods, 'previous day at the same time of the injury' (pair match) and the previous work week (usual frequency). This study protocol describes a unique opportunity to calculate the effect of transient risk factors on occupational injuries in a European setting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Evaluation of control laws and actuator locations for control systems applicable to deformable astronomical telescope mirrors

NASA Technical Reports Server (NTRS)

Ostroff, A. J.

1973-01-01

Some of the major difficulties associated with large orbiting astronomical telescopes are the cost of manufacturing the primary mirror to precise tolerances and the maintaining of diffraction-limited tolerances while in orbit. One successfully demonstrated approach for minimizing these problem areas is the technique of actively deforming the primary mirror by applying discrete forces to the rear of the mirror. A modal control technique, as applied to active optics, has previously been developed and analyzed. The modal control technique represents the plant to be controlled in terms of its eigenvalues and eigenfunctions which are estimated via numerical approximation techniques. The report includes an extension of previous work using the modal control technique and also describes an optimal feedback controller. The equations for both control laws are developed in state-space differential form and include such considerations as stability, controllability, and observability. These equations are general and allow the incorporation of various mode-analyzer designs; two design approaches are presented. The report also includes a technique for placing actuator and sensor locations at points on the mirror based upon the flexibility matrix of the uncontrolled or unobserved modes of the structure. The locations selected by this technique are used in the computer runs which are described. The results are based upon three different initial error distributions, two mode-analyzer designs, and both the modal and optimal control laws.

Job insecurity during recessions: effects on survivors' work stress.

PubMed

Modrek, Sepideh; Cullen, Mark R

2013-10-06

Previous studies show a variety of negative health consequences for the remaining workforce after downsizing events. This study examined self-reported work stress from 2009-2012 in the context of a large multi-site aluminum manufacturing company that underwent severe downsizing in 2009. This study examined the association between work stress and working at a work site that underwent severe downsizing. We assessed the level of downsizing across thirty plants in 2009 and categorized seven as having undergone severe downsizing. We linked plant-level downsizing information to individual workers' responses to an annual work engagement survey, which included three work stress questions. From 2009 to 2012 over 14, 000 employees were asked about their experience of work stress. Though the surveys were anonymous, the surveys captured employees' demographic and employment characteristic as well as plant location. We used hierarchical logistic regressions to compare responses of workers at severely downsized plants to workers at all other plant while controlling for demographic and plant characteristics. Responses to the work stress questions and one control question were examined. In all yearly surveys salaried workers consistently reported having more work stress than hourly workers. There was no differential in work stress for workers at severely downsized plants in 2009. In 2010 to 2012, salaried workers who remained at severely downsized plants reported significantly higher work stress than salaried workers at all other plants across multiple work stress questions. Examination of the 2006 survey confirmed that there were no pre-existing differences in work stress among salaried employees working at plants that would eventually experience severe downsizing. In addition, there was no difference in responses to the control question at severely downsized plants. Salaried workers at plants with high layoffs experienced more work stress after 2009 than their counterparts at non-high layoff plants. Increased work stress is important to monitor and may be a mediating pathway through which the external economic environment leads to adverse health outcomes.

Application of Copper Indium Gallium Diselenide Photovoltaic Cells to Extend the Endurance and Capabilities of the Raven RQ-11B Unmanned Aerial Vehicle

DTIC Science & Technology

2010-09-01

POWER POINT TRACKER A more suitable component used in photovoltaic appli- cations is the Maximum Power Point Tracker ( MPPT ). An MPPT ... MPPT / power converter (Solar Charge Controller ) weighed 6.5-Oz, but without the casing it weighed only 3.6-Oz. We preferred to use it without the...for this test was the GV-4 Low Power Charge Controller from GENASUN used in previous the- sis work [5]. This MPPT was programmed to charge up

Recognizing the Effects of Language Mode on the Cognitive Advantages of Bilingualism.

PubMed

Yu, Ziying; Schwieter, John W

2018-01-01

For bilinguals, it is argued that a cognitive advantage can be linked to the constant management and need for conflict resolution that occurs when the two languages are co-activated (Bialystok, 2015). Language mode (Grosjean, 1998, 2001) is a significant variable that defines and shapes the language experiences of bilinguals and consequently, the cognitive advantages of bilingualism. Previous work, however, has not sufficiently tested the effects of language mode on the bilingual experience. In this brief conceptual analysis, we discuss the significance of language mode in bilingual work on speech perception, production, and reading. We offer possible explanations for conflicting findings and ways in which future work should control for its modulating effects.

Work outcomes and their predictors in the Redesigning Daily Occupations (ReDO) rehabilitation programme for women with stress-related disorders.

PubMed

Eklund, Mona; Wästberg, Birgitta A; Erlandsson, Lena-Karin

2013-04-01

Previous research has shown that the Redesigning Daily Occupations programme reduced the degree of sick leave and increased return to work rates among women on sick leave for stress-related disorders when compared with "care as usual". To further investigate the Redesigning Daily Occupations intervention, this study explored changes in the work situation from baseline to a 12-month follow-up in the Redesigning Daily Occupations group compared with the "care as usual" group and analysed any predictors of change. A matched-control design was used and 84 women were recruited. Objective (return to work and sick leave) and subjective work outcomes (perceptions of the worker role and the work environment) were explored. Potential predictors were clinical and demographic variables and an anxiety-depression factor. In both groups, large positive effect sizes from baseline to follow-up were found regarding the objective outcomes, a moderate positive effect size was found for perceived work environment, whereas perceived worker role remained unaffected. Previous work rehabilitation predicted objective work outcomes in both groups. Higher education and older age were predictors of subjective outcomes in the Redesigning Daily Occupations group, whereas a more severe anxiety-depression rating was negative for work environment ratings in the "care as usual" group. Return to work seemed possible without a change in the women's perceptions of the worker role; rather they renegotiated their view of the work environment. The Redesigning Daily Occupations programme was found to be promising, with a positive effect on return to work and sick leave reduction. It seemed more suitable for the higher educated and older women. © 2012 The Authors Australian Occupational Therapy Journal © 2012 Occupational Therapy Australia.

Comparative study between two different active flutter suppression systems

NASA Technical Reports Server (NTRS)

Nissim, E.

1978-01-01

An activated leading-edge (LE)-tailing-edge (TE) control system is applied to a drone aircraft with the objective of enabling the drone to fly subsonically at dynamic pressures which are 44% above the open-loop flutter dynamic pressure. The control synthesis approach is based on the aerodynamic energy concept and it incorporates recent developments in this area. A comparison is made between the performance of the activated LE-TE control system and the performance of a TE control system, analyzed in a previous work. The results obtained indicate that although all the control systems achieve the flutter suppression objectives, the TE control system appears to be somewhat superior to the LE-TE control system, in this specific application. This superiority is manifested through reduced values of control surface activity over a wide range of flight conditions.

Risk factors control for primary prevention of cardiovascular disease in men: Evidence from the Aragon Workers Health Study (AWHS).

PubMed

Aguilar-Palacio, Isabel; Malo, Sara; Feja, Cristina; Lallana, MªJesús; León-Latre, Montserrat; Casasnovas, José Antonio; Rabanaque, MªJosé; Guallar, Eliseo

2018-01-01

Benefits of cardiovascular disease (CVD) risk factors control are well known, but goals achievement remains low. The objective of this study is to evaluate the prevalence of CVD risk factors among men ina worker's cohort with no previous CVD, to study control variations across time and the factors associated with poor control. To this end, we conducted a cohort reexamination (2010-2014) within the context of the Aragon Workers Health Study (AWHS). Data from working characteristics, analytical values and pharmacological prescription were included in the analysis. Prevalences of risk factor diagnosis and control were calculated, as well as factors associated with poor control. The prevalence of CVD risk factors was high. In 2014dyslipidaemia was the most prevalent (85.2%) followed by Hypertension (HT) (42.0%). People under treatment increased for the period analysed (p<0.001). The proportion of people treated varied from 72.2% in Diabetes Mellitus to 31.1% in dyslipidaemia in 2014. 46.2% of the workers with HT were controlled, decreasing to 21.9% in Diabetes and 11.0% in dyslipidaemia (2014). Working in a turn different to central shift was associated with poor control, especially for those working at night with HT (Odds Ratio in 2010: 3.6; Confidence Interval 95% 1.8-7.4) and dyslipidaemia (Odds Ratio 2010: 4.7; Confidence Interval 95% 1.3-16.4). We conclude that, although CVD control has increased significantly for the period studied, there are still many people that do not receive any treatment, and control goals are normally not achieved.

Experimental validation of flexible robot arm modeling and control

NASA Technical Reports Server (NTRS)

Ulsoy, A. Galip

1989-01-01

Flexibility is important for high speed, high precision operation of lightweight manipulators. Accurate dynamic modeling of flexible robot arms is needed. Previous work has mostly been based on linear elasticity with prescribed rigid body motions (i.e., no effect of flexible motion on rigid body motion). Little or no experimental validation of dynamic models for flexible arms is available. Experimental results are also limited for flexible arm control. Researchers include the effects of prismatic as well as revolute joints. They investigate the effect of full coupling between the rigid and flexible motions, and of axial shortening, and consider the control of flexible arms using only additional sensors.

Optical analysis for simplified astigmatic correction of non-imaging focusing heliostat

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

Chong, K.K.

2010-08-15

In the previous work, non-imaging focusing heliostat that consists of m x n facet mirrors can carry out continuous astigmatic correction during sun-tracking with the use of only (m + n - 2) controllers. For this paper, a simplified astigmatic correction of non-imaging focusing heliostat is proposed for reducing the number of controllers from (m + n - 2) to only two. Furthermore, a detailed optical analysis of the new proposal has been carried out and the simulated result has shown that the two-controller system can perform comparably well in astigmatic correction with a much simpler and more cost effectivemore » design. (author)« less

Validation of engineering methods for predicting hypersonic vehicle controls forces and moments

NASA Technical Reports Server (NTRS)

Maughmer, M.; Straussfogel, D.; Long, L.; Ozoroski, L.

1991-01-01

This work examines the ability of the aerodynamic analysis methods contained in an industry standard conceptual design code, the Aerodynamic Preliminary Analysis System (APAS II), to estimate the forces and moments generated through control surface deflections from low subsonic to high hypersonic speeds. Predicted control forces and moments generated by various control effectors are compared with previously published wind-tunnel and flight-test data for three vehicles: the North American X-15, a hypersonic research airplane concept, and the Space Shuttle Orbiter. Qualitative summaries of the results are given for each force and moment coefficient and each control derivative in the various speed ranges. Results show that all predictions of longitudinal stability and control derivatives are acceptable for use at the conceptual design stage.

Control strategies for crane systems: A comprehensive review

NASA Astrophysics Data System (ADS)

Ramli, Liyana; Mohamed, Z.; Abdullahi, Auwalu M.; Jaafar, H. I.; Lazim, Izzuddin M.

2017-10-01

Crane systems are tremendously utilised in numerous heavy load transportation industries, and therefore, the control of crane systems is a well-established research field. As the last review paper was published more than a decade ago, there is a lack of collected and organised information regarding the latest and the newest updates on control strategies for crane control systems. Hence, this paper presents a comprehensive review of crane control strategies discussing the latest research works during the years from 2000 to 2016. Various crane types and control issues are highlighted, followed by the main focus of this paper, an extensive review of the control schemes for diverse types of crane systems that have been carried out in the 21st century. A brief review on modelling of single-pendulum and double-pendulum crane systems is also given. In addition, anti-sway control systems for industrial cranes that are available on the market is described. This paper summarises most of the related work and also pays a special focus on research trends regarding the control of crane systems that have been previously published in the literature. It is envisaged that this review paper will be helpful to new researchers when identifying research directions for this particular area of interest.

Exposure to welding fumes is associated with hypomethylation of the F2RL3 gene: a cardiovascular disease marker

PubMed Central

Hossain, Mohammad B; Li, Huiqi; Hedmer, Maria; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

2015-01-01

Background Welders are at risk for cardiovascular disease. Recent studies linked tobacco smoke exposure to hypomethylation of the F2RL3 (coagulation factor II (thrombin) receptor-like 3) gene, a marker for cardiovascular disease prognosis and mortality. However, whether welding fumes cause hypomethylation of F2RL3 remains unknown. Methods We investigated 101 welders (median span of working as a welder: 7 years) and 127 unexposed controls (non-welders with no obvious exposure to respirable dust at work), age range 23–60 years, all currently non-smoking, in Sweden. The participants were interviewed about their work history, lifestyle factors and diseases. Personal sampling of respirable dust was performed for the welders. DNA methylation of F2RL3 in blood was assessed by pyrosequencing of four CpG sites, CpG_2 (corresponds to cg03636183) to CpG_5, in F2RL3. Multivariable linear regression analysis was used to assess the association between exposure to welding fumes and F2RL3 methylation. Results Welders had 2.6% lower methylation of CpG_5 than controls (p<0.001). Higher concentrations of measured respirable dust among the welders were associated with hypomethylation of CpG_2, CpG_4 and CpG_5 (β=−0.49 to −1.4, p<0.012); p<0.029 adjusted for age, previous smoking, passive smoking, education, current residence and respirator use. Increasing the number of years working as a welder was associated with hypomethylation of CpG_4 (linear regression analysis, β=−0.11, p=0.039, adjusted for previous smoking). Previous tobacco smokers had 1.5–4.7% (p<0.014) lower methylation of 3 of the 4 CpG sites in F2RL3 (CpG_2, CpG_4 and CpG_5) compared to never-smokers. A non-significant lower risk of cardiovascular disease with more methylation was observed for all CpG sites. Conclusions Welding fumes exposure and previous smoking were associated with F2RL3 hypomethylation. This finding links low-to-moderate exposure to welding fumes to adverse effects on the cardiovascular system, and suggests a potential mechanistic pathway for this link, via epigenetic effects on F2RL3 expression. PMID:26395445

Neural hyperactivity related to working memory in drug-naive boys with attention deficit hyperactivity disorder.

PubMed

Li, Yuanyuan; Li, Fei; He, Ning; Guo, Lanting; Huang, Xiaoqi; Lui, Su; Gong, Qiyong

2014-08-04

Impaired working memory is thought to be a core feature of attention deficit hyperactivity disorder (ADHD). Previous imaging studies investigating working memory in ADHD have used tasks involving different cognitive resources and ignoring the categorical judgments about objects that are essential parts of performance in visual working memory tasks, thus complicating the interpretation of their findings. In the present study, we explored differential neural activation in children and adolescents with ADHD and in healthy controls using functional magnetic resonance imaging (fMRI) with the categorical n-back task (CN-BT), which maximized demands for executive reasoning while holding memory demands constant. A total of 33 drug-naive, right-handed male ADHD without comorbidity (mean age 9.9±2.4 years) and 27 right-handed, healthy male controls (mean age 10.9±2.7 years) were recruited in the present study. Event-related fMRI was used to study differences in brain activity during the CN-BT between the two groups. The two groups did not differ in their accuracy in the CN-BT, although the ADHD patients showed significantly shorter reaction times to correct responses than did the controls. During the CN-BT, both ADHD patients and controls showed significant positive and negative activations by the correct responses, mainly in the sensory-motor pathways and the striato-cerebellum circuit. Additionally, the ADHD patients showed significantly higher activation in the bilateral globus pallidus and the right hippocampus compared with the controls. There was also a positive correlation between hyperactivation of the left globus pallidus and the reaction time to correct responses in ADHD. In contrast to controls, ADHD patients showed neural hyperactivation in the striatum and mediotemporal areas during a working memory task involving categorization. Hyperfunction in these areas might be the pathophysiological foundation of ADHD, related to the deficits of working memory and the impulsive symptoms. Copyright © 2014 Elsevier Inc. All rights reserved.

Working on wellness (WOW): A worksite health promotion intervention programme

PubMed Central

2012-01-01

Background Insufficient PA has been shown to cluster with other CVD risk factors including insufficient fruit and vegetable intake, overweight, increased serum cholesterol concentrations and elevated blood pressure. This paper describes the development of Working on Wellness (WOW), a worksite intervention program incorporating motivational interviewing by wellness specialists, targeting employees at risk. In addition, we describe the evaluation the effectiveness of the intervention among employees at increased risk for cardiovascular disease. Methods The intervention mapping (IM) protocol was used in the planning and design of WOW. Focus group discussions and interviews with employees and managers identified the importance of addressing risk factors for CVD at the worksite. Based on the employees’ preference for individual counselling, and previous evidence of the effectiveness of this approach in the worksite setting, we decided to use motivational interviewing as part of the intervention strategy. Thus, as a cluster-randomised, controlled control trial, employees at increased risk for CVD (N = 928) will be assigned to a control or an intervention group, based on company random allocation. The sessions will include motivational interviewing techniques, comprised of two face-to-face and four telephonic sessions, with the primary aim to increase habitual levels of PA. Measures will take place at baseline, 6 and 12 months. Secondary outcomes include changes in nutritional habits, serum cholesterol and glucose concentrations, blood pressure and BMI. In addition, healthcare expenditure and absenteeism will be measured for the economic evaluation. Analysis of variance will be performed to determine whether there were significant changes in physical activity habits in the intervention and control groups at 6 and 12 months. Discussion The formative work on which this intervention is based suggests that the strategy of targeting employees at increased risk for CVD is preferred. Importantly, this study extends the work of a previous, similar study, Health Under Construction, in a different setting. Finally, this study will allow an economic evaluation of the intervention that will be an important outcome for health care funders, who ultimately will be responsible for implementation of such an intervention. Trial registration United States Clinical Trails Register NCT 01494207 PMID:22625844

Working on wellness (WOW): a worksite health promotion intervention programme.

PubMed

Kolbe-Alexander, Tracy L; Proper, Karin I; Lambert, Estelle V; van Wier, Marieke F; Pillay, Julian D; Nossel, Craig; Adonis, Leegale; Van Mechelen, Willem

2012-05-24

Insufficient PA has been shown to cluster with other CVD risk factors including insufficient fruit and vegetable intake, overweight, increased serum cholesterol concentrations and elevated blood pressure. This paper describes the development of Working on Wellness (WOW), a worksite intervention program incorporating motivational interviewing by wellness specialists, targeting employees at risk. In addition, we describe the evaluation the effectiveness of the intervention among employees at increased risk for cardiovascular disease. The intervention mapping (IM) protocol was used in the planning and design of WOW. Focus group discussions and interviews with employees and managers identified the importance of addressing risk factors for CVD at the worksite. Based on the employees' preference for individual counselling, and previous evidence of the effectiveness of this approach in the worksite setting, we decided to use motivational interviewing as part of the intervention strategy. Thus, as a cluster-randomised, controlled control trial, employees at increased risk for CVD (N = 928) will be assigned to a control or an intervention group, based on company random allocation. The sessions will include motivational interviewing techniques, comprised of two face-to-face and four telephonic sessions, with the primary aim to increase habitual levels of PA. Measures will take place at baseline, 6 and 12 months. Secondary outcomes include changes in nutritional habits, serum cholesterol and glucose concentrations, blood pressure and BMI. In addition, healthcare expenditure and absenteeism will be measured for the economic evaluation. Analysis of variance will be performed to determine whether there were significant changes in physical activity habits in the intervention and control groups at 6 and 12 months. The formative work on which this intervention is based suggests that the strategy of targeting employees at increased risk for CVD is preferred. Importantly, this study extends the work of a previous, similar study, Health Under Construction, in a different setting. Finally, this study will allow an economic evaluation of the intervention that will be an important outcome for health care funders, who ultimately will be responsible for implementation of such an intervention. United States Clinical Trails Register NCT 01494207.

Trajectory following and stabilization control of fully actuated AUV using inverse kinematics and self-tuning fuzzy PID.

PubMed

Hammad, Mohanad M; Elshenawy, Ahmed K; El Singaby, M I

2017-01-01

In this work a design for self-tuning non-linear Fuzzy Proportional Integral Derivative (FPID) controller is presented to control position and speed of Multiple Input Multiple Output (MIMO) fully-actuated Autonomous Underwater Vehicles (AUV) to follow desired trajectories. Non-linearity that results from the hydrodynamics and the coupled AUV dynamics makes the design of a stable controller a very difficult task. In this study, the control scheme in a simulation environment is validated using dynamic and kinematic equations for the AUV model and hydrodynamic damping equations. An AUV configuration with eight thrusters and an inverse kinematic model from a previous work is utilized in the simulation. In the proposed controller, Mamdani fuzzy rules are used to tune the parameters of the PID. Nonlinear fuzzy Gaussian membership functions are selected to give better performance and response in the non-linear system. A control architecture with two feedback loops is designed such that the inner loop is for velocity control and outer loop is for position control. Several test scenarios are executed to validate the controller performance including different complex trajectories with and without injection of ocean current disturbances. A comparison between the proposed FPID controller and the conventional PID controller is studied and shows that the FPID controller has a faster response to the reference signal and more stable behavior in a disturbed non-linear environment.

Trajectory following and stabilization control of fully actuated AUV using inverse kinematics and self-tuning fuzzy PID

PubMed Central

Elshenawy, Ahmed K.; El Singaby, M.I.

2017-01-01

In this work a design for self-tuning non-linear Fuzzy Proportional Integral Derivative (FPID) controller is presented to control position and speed of Multiple Input Multiple Output (MIMO) fully-actuated Autonomous Underwater Vehicles (AUV) to follow desired trajectories. Non-linearity that results from the hydrodynamics and the coupled AUV dynamics makes the design of a stable controller a very difficult task. In this study, the control scheme in a simulation environment is validated using dynamic and kinematic equations for the AUV model and hydrodynamic damping equations. An AUV configuration with eight thrusters and an inverse kinematic model from a previous work is utilized in the simulation. In the proposed controller, Mamdani fuzzy rules are used to tune the parameters of the PID. Nonlinear fuzzy Gaussian membership functions are selected to give better performance and response in the non-linear system. A control architecture with two feedback loops is designed such that the inner loop is for velocity control and outer loop is for position control. Several test scenarios are executed to validate the controller performance including different complex trajectories with and without injection of ocean current disturbances. A comparison between the proposed FPID controller and the conventional PID controller is studied and shows that the FPID controller has a faster response to the reference signal and more stable behavior in a disturbed non-linear environment. PMID:28683071

Meal Disturbance Effect on Control of Blood Glucose Level for Critically-ill Patients using In-silico Works

NASA Astrophysics Data System (ADS)

Yusof, N. F. M.; Som, A. M.; Ali, S. A.; Azman, N. H.

2018-05-01

This study was conducted to determine the effect of meal disturbance on blood glucose level of the critically ill patients and to simulate the control algorithm previously developed using in-silico works. The study is significant so as to reduce the mortality rate of critically ill patients who usually encounter hyperglycaemia or/and hypoglycaemia while in treatment. The meal intake is believed to affect the blood glucose regulation and causes the hyperglycaemia to occur. Critically ill patients receive their meal through parenteral and enteral nutrition. Furthermore, by using in-silico works, time consumed and resources needed for clinical evaluation of the patients can be reduced. Hovorka model was employed in which the simulation study was carried out using MATLAB on the virtual patient and it was being compared with actual patient in which the data were provided by Institut Jantung Negara (IJN). Based on the simulation, the disturbance on enteral glucose supplied had affected the blood glucose level of the patient; however, it remained unchanged for the parental glucose. To reduce the occurrence of hypoglycaemia and hyperglycaemia, the patient was injected with 30 g/hr and 10 g/hr of enteral glucose, respectively. In conclusion, the disturbance of meal received can be controlled through in-silico works.

Changes in work affect in response to lunchtime walking in previously physically inactive employees: A randomized trial.

PubMed

Thøgersen-Ntoumani, C; Loughren, E A; Kinnafick, F-E; Taylor, I M; Duda, J L; Fox, K R

2015-12-01

Physical activity may regulate affective experiences at work, but controlled studies are needed and there has been a reliance on retrospective accounts of experience. The purpose of the present study was to examine the effect of lunchtime walks on momentary work affect at the individual and group levels. Physically inactive employees (N = 56; M age = 47.68; 92.86% female) from a large university in the UK were randomized to immediate treatment or delayed treatment (DT). The DT participants completed both a control and intervention period. During the intervention period, participants partook in three weekly 30-min lunchtime group-led walks for 10 weeks. They completed twice daily affective reports at work (morning and afternoon) using mobile phones on two randomly chosen days per week. Multilevel modeling was used to analyze the data. Lunchtime walks improved enthusiasm, relaxation, and nervousness at work, although the pattern of results differed depending on whether between-group or within-person analyses were conducted. The intervention was effective in changing some affective states and may have broader implications for public health and workplace performance. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Role of Cognitive Load in Intentional Forgetting Using the Think/No-Think Task.

PubMed

Noreen, Saima; de Fockert, Jan W

2017-01-01

We investigated the role of cognitive control in intentional forgetting by manipulating working memory load during the think/no-think task. In two experiments, participants learned a series of cue-target word pairs and were asked to recall the target words associated with some cues or to avoid thinking about the target associated with other cues. In addition to this, participants also performed a modified version of the n-back task which required them to respond to the identity of a single target letter present in the currently presented cue word (n = 0 condition, low working memory load), and in either the previous cue word (n = 1 condition, high working memory load, Experiment 1) or the cue word presented two trials previously (n = 2 condition, high working memory load, Experiment 2). Participants' memory for the target words was subsequently tested using same and novel independent probes. In both experiments it was found that although participants were successful at forgetting on both the same and independent-probe tests in the low working memory load condition, they were only successful at forgetting on the same-probe test in the high working memory load condition. We argue that our findings suggest that the high load working memory task diverted attention from direct suppression and acted as an interference-based strategy. Thus, when cognitive resources are limited participants can switch between the strategies they use to prevent unwanted memories from coming to mind.

Effects of Three Diagram Instruction Methods on Transfer of Diagram Comprehension Skills: The Critical Role of Inference While Learning

ERIC Educational Resources Information Center

Cromley, Jennifer G.; Bergey, Bradley W.; Fitzhugh, Shannon; Newcombe, Nora; Wills, Theodore W.; Shipley, Thomas F.; Tanaka, Jacqueline C.

2013-01-01

Can students be taught to better comprehend the diagrams in their textbooks? Can such teaching transfer to uninstructed diagrams in the same domain or even in a new domain? What methods work best for these goals? Building on previous research showing positive results compared to control groups in both laboratory studies and short-term…

Case control study of neuroblastoma in west-Germany after the Chernobyl accident.

PubMed

Michaelis, J; Haaf, H G; Zöllner, J; Kaatsch, P; Krummenauer, F; Berthold, F

1996-01-01

To explore possible causes of a 1988 incidence peak of infant neuroblastoma in west German regions which were contaminated with more than 6000 Bq/m2 Cs137 from the Chernobyl accident. The primary working hypothesis was that parents of the diseased children had been contaminated by an excessive intake of locally produced food, especially mushrooms or deer. Case control study with 1:2 (cases:controls) matching. Data were collected from the children's parents by questionnaires and telephone interviews. Nation-wide study (former FRG) based on the German Childhood Cancer Registry. Cases born in 1988 and reported with a neuroblastoma to the registry until March 1992. Population-based healthy controls, matched for age, sex and residence at time of diagnosis. The working hypothesis could not be confirmed by the study, because the parents of cases tended to eat less locally grown food than the parents of controls (RR = 0.63, 95% CI:0.20-1.97). Possible influence factors which previously have been described to be associated with neuroblastoma incidence could not be confirmed by the study. Parental exposure to herbicides and pesticides was associated with the occurrence of neuroblastoma (RR = 4.2, 95% CI:1.4-12.9). Neuroblastoma stage distribution in the contaminated regions was shifted towards lower stages as compared to the less contaminated regions and previous age cohorts. The study does not show additional evidence that the observed increase in neuroblastoma incidence might have been caused by exposure to fallout from the Chernobyl accident. The observed shift towards lower clinical stages may rather indicate increased diagnostic awareness. The association between neuroblastoma and parental exposure with herbicides and pesticides resulted from an extensive exploratory data analysis and needs to be confirmed in further studies.

Long-term cognitive impairments and attentional deficits in patients with Cushing's disease and cortisol-producing adrenal adenoma in remission.

PubMed

Ragnarsson, Oskar; Berglund, Peter; Eder, Derek N; Johannsson, Gudmundur

2012-09-01

Cognitive function is impaired in patients with active Cushing's syndrome (CS). The aim was to study cognitive function in patients with CS in long-term remission. We conducted a cross-sectional, case-controlled, single center study. Fifty-five patients previously treated for Cushing's disease (n = 43) and cortisol-producing adrenal adenoma (n = 12) and 55 controls matched for age, gender, and educational level participated in the study. Working memory, attention, information-processing speed, verbal fluency, and reading speed were studied using standardized neuropsychological testing and alerting, orienting, and executive control using the Attentional Network Test. Fatigue impact scale and the comprehensive psychopathological rating scale were used to evaluate fatigue and affective disorder. Median (interquartile range) duration of remission was 13 (5-19) yr and the mean ± SD age at follow-up was 54 ± 14 yr. Compared to controls, patients had a higher score on the fatigue impact scale, indicating greater burdens of fatigue, and a higher score on the comprehensive psychopathological rating scale subscales for depression and anxiety. In a multivariate analysis, attention, spatial orienting, alerting, working memory, verbal fluency, and reading speed were all diminished in comparison to controls, independent of scores for affective disorder and fatigue. No overall difference in outcome was seen between patients in long-term remission for Cushing's disease and cortisol-producing adrenal adenoma. Patients with CS in remission have impaired cognitive function that cannot be explained by the coexistence of affective disorder or chronic fatigue. The pattern of cognitive and attentional deficits suggests a more global involvement of the brain function than has previously been suggested.

Dynamic wake model with coordinated pitch and torque control of wind farms for power tracking

NASA Astrophysics Data System (ADS)

Shapiro, Carl; Meyers, Johan; Meneveau, Charles; Gayme, Dennice

2017-11-01

Control of wind farm power production, where wind turbines within a wind farm coordinate to follow a time-varying power set point, is vital for increasing renewable energy participation in the power grid. Previous work developed a one-dimensional convection-diffusion equation describing the advection of the velocity deficit behind each turbine (wake) as well the turbulent mixing of the wake with the surrounding fluid. Proof-of-concept simulations demonstrated that a receding horizon controller built around this time-dependent model can effectively provide power tracking services by modulating the thrust coefficients of individual wind turbines. In this work, we extend this model-based controller to include pitch angle and generator torque control and the first-order dynamics of the drive train. Including these dynamics allows us to investigate control strategies for providing kinetic energy reserves to the grid, i.e. storing kinetic energy from the wind in the rotating mass of the wind turbine rotor for later use. CS, CM, and DG are supported by NSF (ECCS-1230788, CMMI 1635430, and OISE-1243482, the WINDINSPIRE project). JM is supported by ERC (ActiveWindFarms, 306471). This research was conducted using computational resources at MARCC.

Implementation of a model based fault detection and diagnosis for actuation faults of the Space Shuttle main engine

NASA Technical Reports Server (NTRS)

Duyar, A.; Guo, T.-H.; Merrill, W.; Musgrave, J.

1992-01-01

In a previous study, Guo, Merrill and Duyar, 1990, reported a conceptual development of a fault detection and diagnosis system for actuation faults of the space shuttle main engine. This study, which is a continuation of the previous work, implements the developed fault detection and diagnosis scheme for the real time actuation fault diagnosis of the space shuttle main engine. The scheme will be used as an integral part of an intelligent control system demonstration experiment at NASA Lewis. The diagnosis system utilizes a model based method with real time identification and hypothesis testing for actuation, sensor, and performance degradation faults.

Protein A-like activity and streptococcal cross-reactions.

PubMed Central

Kingston, D

1981-01-01

Recognition of the protein A-like activity of some strains of group A streptococci has thrown doubt on much previous work suggesting antigenic cross-reactions between these streptococci and mammalian tissues. The strains used in our previous studies have now been examined by the mixed reverse passive antiglobulin reaction (MRPAH) for the 'non-specific' absorption of purified Fc portion of human IgG. They were found to have only traces of activity. The strain of Staphylococcus aureus used to control 'non-specific' absorption by bacterial cell walls was strongly positive. Protein A-like material as detected in this way was not therefore responsible for our earlier results. PMID:7039880

Is Job Control a Double-Edged Sword? A Cross-Lagged Panel Study on the Interplay of Quantitative Workload, Emotional Dissonance, and Job Control on Emotional Exhaustion.

PubMed

Konze, Anne-Kathrin; Rivkin, Wladislaw; Schmidt, Klaus-Helmut

2017-12-20

Previous meta-analytic findings have provided ambiguous evidence on job control as a buffering moderator of the adverse impact of job demands on psychological well-being. To disentangle these mixed findings, we examine the moderating effect of job control on the adverse effects of quantitative workload and emotional dissonance as distinct work-related demands on emotional exhaustion over time. Drawing on the job demands-control model, the limited strength model of self-control, and the matching principle we propose that job control can facilitate coping with work-related demands but at the same time may also require employees' self-control. Consequently, we argue that job control buffers the adverse effects of quantitative workload while it reinforces the adverse effects of emotional dissonance, which also necessitates self-control. We examine the proposed relations among employees from an energy supplying company ( N = 139) in a cross-lagged panel study with a six-month time lag. Our results demonstrate a mix of causal and reciprocal effects of job characteristics on emotional exhaustion over time. Furthermore, as suggested, our data provides evidence for contrasting moderating effects of job control. That is, job control buffers the adverse effects of quantitative workload while it reinforces the adverse effects of emotional dissonance on emotional exhaustion.

Is Job Control a Double-Edged Sword? A Cross-Lagged Panel Study on the Interplay of Quantitative Workload, Emotional Dissonance, and Job Control on Emotional Exhaustion

PubMed Central

Rivkin, Wladislaw; Schmidt, Klaus-Helmut

2017-01-01

Previous meta-analytic findings have provided ambiguous evidence on job control as a buffering moderator of the adverse impact of job demands on psychological well-being. To disentangle these mixed findings, we examine the moderating effect of job control on the adverse effects of quantitative workload and emotional dissonance as distinct work-related demands on emotional exhaustion over time. Drawing on the job demands-control model, the limited strength model of self-control, and the matching principle we propose that job control can facilitate coping with work-related demands but at the same time may also require employees’ self-control. Consequently, we argue that job control buffers the adverse effects of quantitative workload while it reinforces the adverse effects of emotional dissonance, which also necessitates self-control. We examine the proposed relations among employees from an energy supplying company (N = 139) in a cross-lagged panel study with a six-month time lag. Our results demonstrate a mix of causal and reciprocal effects of job characteristics on emotional exhaustion over time. Furthermore, as suggested, our data provides evidence for contrasting moderating effects of job control. That is, job control buffers the adverse effects of quantitative workload while it reinforces the adverse effects of emotional dissonance on emotional exhaustion. PMID:29261116

The impact of premorbid and current intellect in schizophrenia: cognitive, symptom, and functional outcomes

PubMed Central

Wells, Ruth; Swaminathan, Vaidy; Sundram, Suresh; Weinberg, Danielle; Bruggemann, Jason; Jacomb, Isabella; Cropley, Vanessa; Lenroot, Rhoshel; Pereira, Avril M; Zalesky, Andrew; Bousman, Chad; Pantelis, Christos; Weickert, Cynthia Shannon; Weickert, Thomas W

2015-01-01

Background: Cognitive heterogeneity among people with schizophrenia has been defined on the basis of premorbid and current intelligence quotient (IQ) estimates. In a relatively large, community cohort, we aimed to independently replicate and extend cognitive subtyping work by determining the extent of symptom severity and functional deficits in each group. Methods: A total of 635 healthy controls and 534 patients with a diagnosis of schizophrenia or schizoaffective disorder were recruited through the Australian Schizophrenia Research Bank. Patients were classified into cognitive subgroups on the basis of the Wechsler Test of Adult Reading (a premorbid IQ estimate) and current overall cognitive abilities into preserved, deteriorated, and compromised groups using both clinical and empirical (k-means clustering) methods. Additional cognitive, functional, and symptom outcomes were compared among the resulting groups. Results: A total of 157 patients (29%) classified as ‘preserved’ performed within one s.d. of control means in all cognitive domains. Patients classified as ‘deteriorated’ (n=239, 44%) performed more than one s.d. below control means in all cognitive domains except estimated premorbid IQ and current visuospatial abilities. A separate 138 patients (26%), classified as ‘compromised,’ performed more than one s.d. below control means in all cognitive domains and displayed greater impairment than other groups on symptom and functional measures. Conclusions: In the present study, we independently replicated our previous cognitive classifications of people with schizophrenia. In addition, we extended previous work by demonstrating worse functional outcomes and symptom severity in the compromised group. PMID:27336046

Acute myeloid and chronic lymphoid leukaemias and exposure to low-level benzene among petroleum workers

PubMed Central

Rushton, L; Schnatter, A R; Tang, G; Glass, D C

2014-01-01

Background: High benzene exposure causes acute myeloid leukaemia (AML). Three petroleum case–control studies identified 60 cases (241 matched controls) for AML and 80 cases (345 matched controls) for chronic lymphoid leukaemia (CLL). Methods: Cases were classified and scored regarding uncertainty by two haematologists using available diagnostic information. Blinded quantitative benzene exposure assessment used work histories and exposure measurements adjusted for era-specific circumstances. Statistical analyses included conditional logistic regression and penalised smoothing splines. Results: Benzene exposures were much lower than previous studies. Categorical analyses showed increased ORs for AML with several exposure metrics, although patterns were unclear; neither continuous exposure metrics nor spline analyses gave increased risks. ORs were highest in terminal workers, particularly for Tanker Drivers. No relationship was found between benzene exposure and risk of CLL, although the Australian study showed increased risks in refinery workers. Conclusion: Overall, this study does not persuasively demonstrate a risk between benzene and AML. A previously reported strong relationship between myelodysplastic syndrome (MDS) (potentially previously reported as AML) at our study's low benzene levels suggests that MDS may be the more relevant health risk for lower exposure. Higher CLL risks in refinery workers may be due to more diverse exposures than benzene alone. PMID:24357793

Using event-related fMRI to examine sustained attention processes and effects of APOE ε4 in young adults.

PubMed

Evans, Simon; Clarke, Devin; Dowell, Nicholas G; Tabet, Naji; King, Sarah L; Hutton, Samuel B; Rusted, Jennifer M

2018-01-01

In this study we investigated effects of the APOE ε4 allele (which confers an enhanced risk of poorer cognitive ageing, and Alzheimer's Disease) on sustained attention (vigilance) performance in young adults using the Rapid Visual Information Processing (RVIP) task and event-related fMRI. Previous fMRI work with this task has used block designs: this study is the first to image an extended (6-minute) RVIP task. Participants were 26 carriers of the APOE ε4 allele, and 26 non carriers (aged 18-28). Pupil diameter was measured throughout, as an index of cognitive effort. We compared activity to RVIP task hits to hits on a control task (with similar visual parameters and response requirements but no working memory load): this contrast showed activity in medial frontal, inferior and superior parietal, temporal and visual cortices, consistent with previous work, demonstrating that meaningful neural data can be extracted from the RVIP task over an extended interval and using an event-related design. Behavioural performance was not affected by genotype; however, a genotype by condition (experimental task/control task) interaction on pupil diameter suggested that ε4 carriers deployed more effort to the experimental compared to the control task. fMRI results showed a condition by genotype interaction in the right hippocampal formation: only ε4 carriers showed downregulation of this region to experimental task hits versus control task hits. Experimental task beta values were correlated against hit rate: parietal correlations were seen in ε4 carriers only, frontal correlations in non-carriers only. The data indicate that, in the absence of behavioural differences, young adult ε4 carriers already show a different linkage between functional brain activity and behaviour, as well as aberrant hippocampal recruitment patterns. This may have relevance for genotype differences in cognitive ageing trajectories.

The authentic worker's well-being and performance: the relationship between authenticity at work, well-being, and work outcomes.

PubMed

van den Bosch, Ralph; Taris, Toon W

2014-01-01

Previous research on authenticity has mainly focused on trait conceptualizations of authenticity (e.g., Wood et al., 2008), whereas in specific environments (e.g., at work) state conceptualizations of authenticity (cf. Van den Bosch & Taris, 2013) are at least as relevant. For example, working conditions are subject to change, and this could well have consequences for employees' perceived level of authenticity at work. The current study employs a work-specific, state-like conceptualization of authenticity to investigate the relations between authenticity at work, well-being, and work outcomes. A series of ten separate hierarchical regression analyses using data from 685 participants indicated that after controlling for selected work characteristics and demographic variables, authenticity at work accounted for on average 11% of the variance of various wellbeing and work outcomes. Of the three subscales of authenticity at work (i.e., authentic living, self-alienation, and accepting influence), self-alienation was the strongest predictor of outcomes, followed by authentic living and accepting external influence, respectively. These findings are discussed in the light of their practical and theoretical implications.

No association of IL-10 promoter SNP -592 and -1082 and SIDS.

PubMed

Courts, Cornelius; Madea, Burkhard

2011-01-30

Sudden infant death syndrome (SIDS) constitutes a considerable percentage of infant death of unknown etiology. The genetically controlled pathway of cytokine mediated response to inflammation is presumed to play a role in SIDS. The A allele of SNP -592 of the promoter region of the anti-inflammatory cytokine IL-10 has been suggested to be associated with SIDS. Herein we investigated whether we could confirm this finding by SNP genotyping a series of 123 cases of SIDS and 406 control cases. We did not find a correlation between the A allele or an A allele containing genotype of IL-10 promoter SNP -592 and SIDS which is in contrast to previous studies. Also, in concordance with previous work, no association of the A allele or A allele containing genotypes of IL-10 promoter SNP -1082 and SIDS was found. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

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

Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

2010-12-29

This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release withmore » unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway« less

Optimal Synthesis of Compliant Mechanisms using Subdivision and Commercial FEA (DETC2004-57497)

NASA Technical Reports Server (NTRS)

Hull, Patrick V.; Canfield, Stephen

2004-01-01

The field of distributed-compliance mechanisms has seen significant work in developing suitable topology optimization tools for their design. These optimal design tools have grown out of the techniques of structural optimization. This paper will build on the previous work in topology optimization and compliant mechanism design by proposing an alternative design space parameterization through control points and adding another step to the process, that of subdivision. The control points allow a specific design to be represented as a solid model during the optimization process. The process of subdivision creates an additional number of control points that help smooth the surface (for example a C(sup 2) continuous surface depending on the method of subdivision chosen) creating a manufacturable design free of some traditional numerical instabilities. Note that these additional control points do not add to the number of design parameters. This alternative parameterization and description as a solid model effectively and completely separates the design variables from the analysis variables during the optimization procedure. The motivation behind this work is to create an automated design tool from task definition to functional prototype created on a CNC or rapid-prototype machine. This paper will describe the proposed compliant mechanism design process and will demonstrate the procedure on several examples common in the literature.

Neural correlates of visuospatial working memory in attention-deficit/hyperactivity disorder and healthy controls.

PubMed

van Ewijk, Hanneke; Weeda, Wouter D; Heslenfeld, Dirk J; Luman, Marjolein; Hartman, Catharina A; Hoekstra, Pieter J; Faraone, Stephen V; Franke, Barbara; Buitelaar, Jan K; Oosterlaan, Jaap

2015-08-30

Impaired visuospatial working memory (VSWM) is suggested to be a core neurocognitive deficit in attention-deficit/hyperactivity disorder (ADHD), yet the underlying neural activation patterns are poorly understood. Furthermore, it is unclear to what extent age and gender effects may play a role in VSWM-related brain abnormalities in ADHD. Functional magnetic resonance imaging (fMRI) data were collected from 109 individuals with ADHD (60% male) and 103 controls (53% male), aged 8-25 years, during a spatial span working memory task. VSWM-related brain activation was found in a widespread network, which was more widespread compared with N-back tasks used in the previous literature. Higher brain activation was associated with higher age and male gender. In comparison with controls, individuals with ADHD showed greater activation in the left inferior frontal gyrus (IFG) and the lateral frontal pole during memory load increase, effects explained by reduced activation on the low memory load in the IFG pars triangularis and increased activation during high load in the IFG pars opercularis. Age and gender effects did not differ between controls and individuals with ADHD. Results indicate that individuals with ADHD have difficulty in efficiently and sufficiently recruiting left inferior frontal brain regions with increasing task difficulty. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Neural control of salivary glands in ixodid ticks.

PubMed

Šimo, Ladislav; Zitňan, Dušan; Park, Yoonseong

2012-04-01

Studies of tick salivary glands (SGs) and their components have produced a number of interesting discoveries over the last four decades. However, the precise neural and physiological mechanisms controlling SG secretion remain enigmatic. Major studies of SG control have identified and characterized many pharmacological and biological compounds that activate salivary secretion, including dopamine (DA), octopamine, γ-aminobutyric acid (GABA), ergot alkaloids, pilocarpine (PC), and their pharmacological relatives. Specifically, DA has shown the most robust activities in various tick species, and its effect on downstream actions in the SGs has been extensively studied. Our recent work on a SG dopamine receptor has aided new interpretations of previous pharmacological studies and provided new concepts for SG control mechanisms. Furthermore, our recent studies have suggested that multiple neuropeptides are involved in SG control. Myoinhibitory peptide (MIP) and SIFamide have been identified in the neural projections reaching the basal cells of acini types II and III. Pigment-dispersing factor (PDF)-immunoreactive neural projections reach type II acini, and RFamide- and tachykinin-immunoreactive projections reach the SG ducts, but the chemical nature of the latter three immunoreactive substances are unidentified yet. Here, we briefly review previous pharmacological studies and provide a revised summary of SG control mechanisms in ticks. Copyright © 2011 Elsevier Ltd. All rights reserved.

Diversified Control Paths: A Significant Way Disease Genes Perturb the Human Regulatory Network

PubMed Central

Wang, Bingbo; Gao, Lin; Zhang, Qingfang; Li, Aimin; Deng, Yue; Guo, Xingli

2015-01-01

Background The complexity of biological systems motivates us to use the underlying networks to provide deep understanding of disease etiology and the human diseases are viewed as perturbations of dynamic properties of networks. Control theory that deals with dynamic systems has been successfully used to capture systems-level knowledge in large amount of quantitative biological interactions. But from the perspective of system control, the ways by which multiple genetic factors jointly perturb a disease phenotype still remain. Results In this work, we combine tools from control theory and network science to address the diversified control paths in complex networks. Then the ways by which the disease genes perturb biological systems are identified and quantified by the control paths in a human regulatory network. Furthermore, as an application, prioritization of candidate genes is presented by use of control path analysis and gene ontology annotation for definition of similarities. We use leave-one-out cross-validation to evaluate the ability of finding the gene-disease relationship. Results have shown compatible performance with previous sophisticated works, especially in directed systems. Conclusions Our results inspire a deeper understanding of molecular mechanisms that drive pathological processes. Diversified control paths offer a basis for integrated intervention techniques which will ultimately lead to the development of novel therapeutic strategies. PMID:26284649

Psychosocial and cognitive factors associated with adherence to dietary and fluid restriction regimens by people on chronic haemodialysis.

PubMed

Sensky, T; Leger, C; Gilmour, S

1996-01-01

Failure by people on chronic haemodialysis to adhere adequately to dietary and fluid restrictions can have serious medical consequences. Numerous psychosocial factors possibly associated with adherence have been investigated in previous research. However, most previous studies have examined one or a few variables in isolation, and have tended to focus on sociodemographic variables not easily amenable to intervention. Much previous work has tended to ignore potential differences in adherence between male and female dialysands. Sociodemographic and psychosocial factors associated with adherence to dietary and fluid restrictions were investigated in 45 people on haemodialysis attending one renal unit, excluding those with a residual urine volume > 500 ml/day. Multiple regression analyses were used to estimate the contribution to adherence of a range of variables, including gender, age, duration of dialysis, affective disturbance, past psychiatric history, health locus of control, social adjustment and social supports. Adherence to diet (measured by predialysis serum potassium) and to fluid restriction (interdialysis weight gain) were not linked, and had different psychosocial correlates. Regression models of four different aspects of adherence revealed very distinct psychosocial correlates, with contributions to adherence from complex interactions between psychosocial and cognitive variables, notably gender, age, social adjustment, health locus of control, and depression. The findings cast doubt on the results of many previous studies which have used simple models of adherence. Adherence is likely to be influenced in a complex manner by multiple factors including age, gender, locus of control, social adjustment, and past psychiatric history.

Effect of Polymer Electrode Morphology on Performance of a Lithium/Polypyrrole Battery. M.S. Thesis

NASA Technical Reports Server (NTRS)

Nicholson, Marjorie Anne

1991-01-01

A variety of conducting polymer batteries were described in the recent literature. In this work, a Li/Polypyrrole secondary battery is described. The effect of controlling the morphology of the polymer on enhancement of counterion diffusion in the polymer phase is explored. A method of preparing conducting polymers was developed which yields high surface area per unit volume of electrode material. A porous membrane is used as a template in which to electrochemically polymerize pyrrole, then the membrane is dissolved, leaving the polymer in a fibrillar form. Conventionally, the polymer is electrochemically polymerized as a dense polymer film on a smooth Pt disk electrode. Previous work has shown that when the polymer is electrochemically polymerized in fribrillar form, charge transport rates are faster and charge capacities are greater than for dense, conventionally grown films containing the same amount of polymer. The purpose is to expand previous work by further investigating the possibilities of the optimization of transport rates in polypyrrole films by controlling the morphology of the films. The utility of fibrillar polypyrrole as a cathode material in a lithium/polymer secondary battery is then assessed. The performance of the fibrillar battery is compared to the performance of an analogous battery which employed a conventionally grown polypyrrole film. The study includes a comparison of cyclic voltammetry, shape of charge/discharge curves, discharge time and voltage, cycle life, coulombic efficiencies, charge capacities, energy densities, and energy efficiencies.

Caring for the Elderly at Work and Home: Can a Randomized Organizational Intervention Improve Psychological Health?

PubMed

Kossek, Ellen Ernst; Thompson, Rebecca J; Lawson, Katie M; Bodner, Todd; Perrigino, Matthew B; Hammer, Leslie B; Buxton, Orfeu M; Almeida, David M; Moen, Phyllis; Hurtado, David A; Wipfli, Brad; Berkman, Lisa F; Bray, Jeremy W

2017-12-07

Although job stress models suggest that changing the work social environment to increase job resources improves psychological health, many intervention studies have weak designs and overlook influences of family caregiving demands. We tested the effects of an organizational intervention designed to increase supervisor social support for work and nonwork roles, and job control in a results-oriented work environment on the stress and psychological distress of health care employees who care for the elderly, while simultaneously considering their own family caregiving responsibilities. Using a group-randomized organizational field trial with an intent-to-treat design, 420 caregivers in 15 intervention extended-care nursing facilities were compared with 511 caregivers in 15 control facilities at 4 measurement times: preintervention and 6, 12, and 18 months. There were no main intervention effects showing improvements in stress and psychological distress when comparing intervention with control sites. Moderation analyses indicate that the intervention was more effective in reducing stress and psychological distress for caregivers who were also caring for other family members off the job (those with elders and those "sandwiched" with both child and elder caregiving responsibilities) compared with employees without caregiving demands. These findings extend previous studies by showing that the effect of organizational interventions designed to increase job resources to improve psychological health varies according to differences in nonwork caregiving demands. This research suggests that caregivers, especially those with "double-duty" elder caregiving at home and work and "triple-duty" responsibilities, including child care, may benefit from interventions designed to increase work-nonwork social support and job control. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Fathers Matter: The Role of Father Autonomy Support and Control in Preschoolers' Executive Function Development

PubMed Central

Meuwissen, Alyssa S.; Carlson, Stephanie M.

2015-01-01

Although previous work has shown that mothers' parenting influences the development of child executive function (important self-control skills developed in the preschool years) the role of fathers' parenting has not been thoroughly investigated. We observed fathers' autonomy support and control in dyadic play with their 3-year-old children (N pairs = 110), and measured father and child EF independently with laboratory tasks. We found that fathers' controlling parenting was significantly inversely related to the child EF composite, above and beyond family income and child verbal ability. These results are consistent with the hypothesis that fathers are important for the development of EF in their children, and suggest fathers should be included in both research and parenting interventions. PMID:26209884

Pituitary gland levels of mercury, selenium, iron, and zinc in an Alzheimer`s disease study

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

Cornett, C.R.; Markesbery, W.R.; Wekstein, D.R.

1996-12-31

Mercury, iron, selenium, and zinc imbalances have been observed in comparisons between Alzheimer`s disease (AD) and control subject brains. Analyses of the pituitary gland have demonstrated that this organ retains relatively high concentrations of trace elements, including mercury, iron, and zinc. Our previous work has shown that the pituitary glands of AD and control subjects are typically higher in these trace elements than brain samples from the same subject. Instrumental neutron activation analysis (INAA) was used to compare the pituitary trace element levels of AD and control subjects. This study also describes the intrasubject relationships of brain trace element levelsmore » to those in the pituitary gland of AD and control subjects.« less

Adaptive neural control for a class of nonlinear time-varying delay systems with unknown hysteresis.

PubMed

Liu, Zhi; Lai, Guanyu; Zhang, Yun; Chen, Xin; Chen, Chun Lung Philip

2014-12-01

This paper investigates the fusion of unknown direction hysteresis model with adaptive neural control techniques in face of time-delayed continuous time nonlinear systems without strict-feedback form. Compared with previous works on the hysteresis phenomenon, the direction of the modified Bouc-Wen hysteresis model investigated in the literature is unknown. To reduce the computation burden in adaptation mechanism, an optimized adaptation method is successfully applied to the control design. Based on the Lyapunov-Krasovskii method, two neural-network-based adaptive control algorithms are constructed to guarantee that all the system states and adaptive parameters remain bounded, and the tracking error converges to an adjustable neighborhood of the origin. In final, some numerical examples are provided to validate the effectiveness of the proposed control methods.

Allee effects in tritrophic food chains: some insights in pest biological control.

PubMed

Costa, Michel Iskin da S; Dos Anjos, Lucas

2016-12-01

Release of natural enemies to control pest populations is a common strategy in biological control. However, its effectiveness is supposed to be impaired, among other factors, by Allee effects in the biological control agent and by the fact that introduced pest natural enemies interact with some native species of the ecosystem. In this work, we devise a tritrophic food chain model where the assumptions previously raised are proved correct when a hyperpredator attacks the introduced pest natural enemy by a functional response type 2 or 3. Moreover, success of pest control is shown to be related to the release of large amounts (i.e., inundative releases) of natural enemies. © The authors 2015. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Survey of asthma management in Thailand - the asthma insight and management study.

PubMed

Boonsawat, Watchara; Thompson, Philip J; Zaeoui, Uraiwan; Samosorn, Chanee; Acar, Gurbet; Faruqi, Rab; Poonnoi, Piriya

2015-03-01

Previous Thai surveys of asthma care have shown suboptimal management and poor control. Since then several editions of the Thailand National Asthma Guidelines have been distributed to help improve asthma control. A new survey was undertaken to see if any improvement in care had occurred. It examined patients' insights, attitudes and perceptions about their asthma and its treatment. Asthma patients (>12 years) were randomly selected and participated in face-to-face interviews. Patients answered 53 questions exploring general health, diagnosis, symptoms, exacerbations, patient burden, disease management, treatment and attitudes. The Global Initiative for Asthma guidelines were used to assess asthma control. Data were obtained from 400 asthma patients from 8,177 screened households. This showed that 36% had had exacerbations in the previous year, 17% had been hospitalized and 35% had had an unscheduled emergency visit to hospital or a doctor's office or clinic. Work or school was missed by 44% due to asthma while a similar number had had an asthma episode that made them feel their life was in danger. Only 8% had good asthma control. Patients had low expectations with respect to asthma treatment and their understanding of how to use therapies was poor. Forty-four percent of participants reported day-time symptoms and about one-third (34%) of adults and adolescents in the survey reported night-time symptoms at least once a week in the previous 4 weeks. Asthma patients in Thailand rated their average productivity when asthma was at its worst at 48%, on a scale of 0 to 100%, which equates to a 36% decline in productivity. Rescue medication during the previous four weeks had been used by 44% of asthma patients while 54% had used a controller medication. Pill controller medication is the most used form among those reporting controller medication use (67%), whereas 57% reported taking an inhaler. Oral steroids had been used in the previous 12 months by 40% of patients with the average number for 3 day or longer at 24 times, while the median was about 4 times. Asthma had a profound impact on patients' wellbeing, despite the availability of effective treatments and evidence-based management guidelines. A large proportion of asthma patients overestimate their asthma control and have inappropriate concepts about asthma treatment. Gaining better insight into patient's attitudes about self-care is critical to improve asthma management.

Long Range In-Plane Order of Oriented Diblock Copolymer Thin Films by Graphoepitaxy

NASA Astrophysics Data System (ADS)

Fontana, Scott; Dadmun, Mark; Lowndes, Douglas

2003-03-01

Previous work by Russell and coworkers has demonstrated that controlling the interfacial energies and wetting behavior of an asymmetric diblock copolymer enables the control of the orientation of its microphases. In particular the cylindrical phase can be readily aligned perpendicular to a substrate when it is placed on a surface that is neutral to both components of the copolymer. The minor phase, PMMA may then be removed using UV radiation leaving a nanoporous template. In this work, we will report long range, in-plane ordering of the hexagonally packed nanopores that is achieved using graphoepitaxy. The long range ordered and vertically aligned diblock copolymer film can be used to produce arrays of catalytic nickel dots, which grow vertically aligned carbon nano-fibers (VACNF), resulting in a well ordered array of VACNFs.

Control of microparticles packing density in a microfluidic channel for bead based immunoassays applications

NASA Astrophysics Data System (ADS)

Caballero-Robledo, Gabriel; Guevara-Pantoja, Pablo

2014-11-01

Bead based immunoassays in microfluidic devices have shown to greatly outperform conventional methods. But if functional point-of-care devices are to be developed, precise and reproducible control over the granulate packings inside microchannels is needed. In this work we study the efficiency of a nanoparticles magnetic trap previously developed by B. Teste et al. [Lab Chip 11, 4207 (2011)] when we vary the compaction of micrometric iron beads packed against a restriction inside a microfluidic channel. The packing density of the beads is finely and reproducibly changed by applying a vibrational protocol originally developed for macroscopic, dry granular systems. We find, counterintuitively, that the most compact and stable packings are up to four times less efficient in trapping nano particles than the loosest packings. This work has been supported by Conacyt, Mexico, under Grant No. 180873.

Telerobotic control of a mobile coordinated robotic server. M.S. Thesis Annual Technical Report

NASA Technical Reports Server (NTRS)

Lee, Gordon

1993-01-01

The annual report on telerobotic control of a mobile coordinated robotic server is presented. The goal of this effort is to develop advanced control methods for flexible space manipulator systems. As such, an adaptive fuzzy logic controller was developed in which model structure as well as parameter constraints are not required for compensation. The work builds upon previous work on fuzzy logic controllers. Fuzzy logic controllers have been growing in importance in the field of automatic feedback control. Hardware controllers using fuzzy logic have become available as an alternative to the traditional PID controllers. Software has also been introduced to aid in the development of fuzzy logic rule-bases. The advantages of using fuzzy logic controllers include the ability to merge the experience and intuition of expert operators into the rule-base and that a model of the system is not required to construct the controller. A drawback of the classical fuzzy logic controller, however, is the many parameters needed to be turned off-line prior to application in the closed-loop. In this report, an adaptive fuzzy logic controller is developed requiring no system model or model structure. The rule-base is defined to approximate a state-feedback controller while a second fuzzy logic algorithm varies, on-line, parameters of the defining controller. Results indicate the approach is viable for on-line adaptive control of systems when the model is too complex or uncertain for application of other more classical control techniques.

ADCS controllers comparison for small satellitess in Low Earth Orbit

NASA Astrophysics Data System (ADS)

Calvo, Daniel; Laverón-Simavilla, Ana; Lapuerta, Victoria

2016-07-01

Fuzzy logic controllers are flexible and simple, suitable for small satellites Attitude Determination and Control Subsystems (ADCS). In a previous work, a tailored Fuzzy controller was designed for a nanosatellite. Its performance and efficiency were compared with a traditional Proportional Integrative Derivative (PID) controller within the same specific mission. The orbit height varied along the mission from injection at around 380 km down to 200 km height, and the mission required pointing accuracy over the whole time. Due to both, the requirements imposed by such a low orbit, and the limitations in the power available for the attitude control, an efficient ADCS is required. Both methodologies, fuzzy and PID, were fine-tuned using an automated procedure to grant maximum efficiency with fixed performances. The simulations showed that the Fuzzy controller is much more efficient (up to 65% less power required) in single manoeuvres, achieving similar, or even better, precision than the PID. The accuracy and efficiency improvement of the Fuzzy controller increase with orbit height because the environmental disturbances decrease, approaching the ideal scenario. However, the controllers are meant to be used in a vast range of situations and configurations which exceed those used in the calibration process carried out in the previous work. To assess the suitability and performance of both controllers in a wider framework, parametric and statistical methods have been applied using the Monte Carlo technique. Several parameters have been modified randomly at the beginning of each simulation: the moments of inertia of the whole satellite and of the momentum wheel, the residual magnetic dipole and the initial conditions of the test. These parameters have been chosen because they are the main source of uncertainty during the design phase. The variables used for the analysis are the error (critical for science) and the operation cost (which impacts the mission lifetime and outcome). The analysis of the simulations has shown that, in overall, the PID error is over twice the Fuzzy error and the PID cost is over 40% bigger than the Fuzzy cost. This suggests that a Fuzzy controller may be a better solution in a wider range of configurations than other classical solutions like the PID.

Feedback Error Learning Controller for Functional Electrical Stimulation Assistance in a Hybrid Robotic System for Reaching Rehabilitation

PubMed Central

Resquín, Francisco; Gonzalez-Vargas, Jose; Ibáñez, Jaime; Brunetti, Fernando; Pons, José Luis

2016-01-01

Hybrid robotic systems represent a novel research field, where functional electrical stimulation (FES) is combined with a robotic device for rehabilitation of motor impairment. Under this approach, the design of robust FES controllers still remains an open challenge. In this work, we aimed at developing a learning FES controller to assist in the performance of reaching movements in a simple hybrid robotic system setting. We implemented a Feedback Error Learning (FEL) control strategy consisting of a feedback PID controller and a feedforward controller based on a neural network. A passive exoskeleton complemented the FES controller by compensating the effects of gravity. We carried out experiments with healthy subjects to validate the performance of the system. Results show that the FEL control strategy is able to adjust the FES intensity to track the desired trajectory accurately without the need of a previous mathematical model. PMID:27990245

Psychosocial aspects of working with video display terminals (VDTs) and employee physical and mental health.

PubMed

Smith, M J

1997-10-01

Psychosocial aspects of using video display terminals (VDTs) have been recognized as contributors to employees' mental and physical health problems for more than 15 years. Yet, little has been done by employers to change work organization conditions to improve the psychosocial work environment of VDT users. Thus, psychosocial aspects of work are emerging as one of the biggest problems for VDT users in the late 1990s. This paper explores how psychosocial aspects of VDT work are related to job stress, and their consequences for mental and physical health. Using the research literature, it defines various aspects of work organization and job design that have been shown to be related to VDT users' ill-health. Some of the important work design aspects uncovered include a lack of employee skill use, monotonous tasks, high job demands and work pressure, a lack of control over the job, poor supervisory relations, fear of job loss, and unreliable technology. These are the same job stressors that have been defined as problematic for a variety of blue collar jobs in previous research. Work organization improvements for healthier VDT jobs are proposed. These include organizational support, employee participation, improved task content, increased job control, reasonable production standards, career development, enhanced peer socialization, and improved workstation ergonomics. These organizational improvements are derived from a more detailed organizational strategy for job stress reduction. A model of job redesign through proper 'balancing' of work organization features is discussed.

Long-term sick leave and its risk factors during pregnancy among Danish hospital employees.

PubMed

Kaerlev, Linda; Jacobsen, Lene B; Olsen, Jørn; Bonde, Jens Peter

2004-01-01

The authors sought to describe risk indicators of long-term sick leave during pregnancy among hospital employees. A register-based study was undertaken of 4,852 female hospital employees aged 20-45 years from the second largest hospital in Denmark during 1995-99 based on job titles, working time, sick leave, and births combined with a survey among a total of 773 women who had been pregnant during their employment (response rate 85%). Altogether 236 (31%) were on sick leave for at least 10% of their scheduled work time during their latest pregnancy and 169 (22%) had been absent at least 20% of the time. The pregnant women had an average sickness absence of 6.1 days per month, non-pregnant women 0.95 days per month. Sick leave was more frequent in late than in early gestation. Women employed as nursing aides or hospital orderlies, launderers, and nurses had more sick leave days than other hospital employees. Part-time work, previous sickness absence not related to pregnancy, and previous chronic back pain were risk factors for long-term sick leave as were much walking or standing, long working days, high work level, little practical support from supervisors and colleagues, low job control, much lifting and night or shift work. Sick leave was unrelated to family size, support from the family and number of working years. Long-term sick leave during pregnancy was frequent and to some extent predictable. Efforts should be made to organize work for pregnant women in a manner that optimizes their health and well-being.

Balanced cortical microcircuitry for spatial working memory based on corrective feedback control.

PubMed

Lim, Sukbin; Goldman, Mark S

2014-05-14

A hallmark of working memory is the ability to maintain graded representations of both the spatial location and amplitude of a memorized stimulus. Previous work has identified a neural correlate of spatial working memory in the persistent maintenance of spatially specific patterns of neural activity. How such activity is maintained by neocortical circuits remains unknown. Traditional models of working memory maintain analog representations of either the spatial location or the amplitude of a stimulus, but not both. Furthermore, although most previous models require local excitation and lateral inhibition to maintain spatially localized persistent activity stably, the substrate for lateral inhibitory feedback pathways is unclear. Here, we suggest an alternative model for spatial working memory that is capable of maintaining analog representations of both the spatial location and amplitude of a stimulus, and that does not rely on long-range feedback inhibition. The model consists of a functionally columnar network of recurrently connected excitatory and inhibitory neural populations. When excitation and inhibition are balanced in strength but offset in time, drifts in activity trigger spatially specific negative feedback that corrects memory decay. The resulting networks can temporally integrate inputs at any spatial location, are robust against many commonly considered perturbations in network parameters, and, when implemented in a spiking model, generate irregular neural firing characteristic of that observed experimentally during persistent activity. This work suggests balanced excitatory-inhibitory memory circuits implementing corrective negative feedback as a substrate for spatial working memory. Copyright © 2014 the authors 0270-6474/14/346790-17$15.00/0.

Articulatory rehearsal in verbal working memory: a possible neurocognitive endophenotype that differentiates between schizophrenia and schizoaffective disorder.

PubMed

Gruber, Oliver; Gruber, Eva; Falkai, Peter

2006-09-11

Recent fMRI studies have identified brain systems underlying different components of working memory in healthy individuals. The aim of this study was to compare the functional integrity of these neural networks in terms of behavioural performance in patients with schizophrenia, schizoaffective disorder and healthy controls. In order to detect specific working memory deficits based on dysfunctions of underlying brain circuits we used the same verbal and visuospatial Sternberg item-recognition tasks as in previous neuroimaging studies. Clinical and performance data from matched groups consisting of 14 subjects each were statistically analyzed. Schizophrenic patients exhibited pronounced impairments of both verbal and visuospatial working memory, whereas verbal working memory performance was preserved in schizoaffective patients. The findings provide first evidence that dysfunction of a brain system subserving articulatory rehearsal could represent a biological marker which differentiates between schizophrenia and schizoaffective disorder.

The Quality of Work in the Belgian Service Voucher System.

PubMed

Mousaid, Sarah; Huegaerts, Kelly; Bosmans, Kim; Julià, Mireia; Benach, Joan; Vanroelen, Christophe

2017-01-01

Several European countries implemented initiatives to boost the growth of the domestic cleaning sector. Few studies investigated the quality of work in these initiatives, although effects on workers' health and on social health inequalities can be expected. This study contributes to the scant research on this subject, by investigating the quality of work in the Belgian service voucher system - a subsidized system for domestic work. The applied research methodology includes a qualitative content analysis of parliamentary debates, legislation and previous research about the service voucher system and of 40 in-depth interviews with service voucher workers. The study shows that the legal framework that regulates the system must be further enhanced in order to improve the quality of work in the service voucher system. In addition, the actors involved must be better controlled, and sanctioned in case of non-compliance with legislation. © The Author(s) 2016.

High-volume manufacturing device overlay process control

NASA Astrophysics Data System (ADS)

Lee, Honggoo; Han, Sangjun; Woo, Jaeson; Lee, DongYoung; Song, ChangRock; Heo, Hoyoung; Brinster, Irina; Choi, DongSub; Robinson, John C.

2017-03-01

Overlay control based on DI metrology of optical targets has been the primary basis for run-to-run process control for many years. In previous work we described a scenario where optical overlay metrology is performed on metrology targets on a high frequency basis including every lot (or most lots) at DI. SEM based FI metrology is performed ondevice in-die as-etched on an infrequent basis. Hybrid control schemes of this type have been in use for many process nodes. What is new is the relative size of the NZO as compared to the overlay spec, and the need to find more comprehensive solutions to characterize and control the size and variability of NZO at the 1x nm node: sampling, modeling, temporal frequency and control aspects, as well as trade-offs between SEM throughput and accuracy.

Cognitive predictors of a common multitasking ability: Contributions from working memory, attention control, and fluid intelligence.

PubMed

Redick, Thomas S; Shipstead, Zach; Meier, Matthew E; Montroy, Janelle J; Hicks, Kenny L; Unsworth, Nash; Kane, Michael J; Hambrick, D Zachary; Engle, Randall W

2016-11-01

Previous research has identified several cognitive abilities that are important for multitasking, but few studies have attempted to measure a general multitasking ability using a diverse set of multitasks. In the final dataset, 534 young adult subjects completed measures of working memory (WM), attention control, fluid intelligence, and multitasking. Correlations, hierarchical regression analyses, confirmatory factor analyses, structural equation models, and relative weight analyses revealed several key findings. First, although the complex tasks used to assess multitasking differed greatly in their task characteristics and demands, a coherent construct specific to multitasking ability was identified. Second, the cognitive ability predictors accounted for substantial variance in the general multitasking construct, with WM and fluid intelligence accounting for the most multitasking variance compared to attention control. Third, the magnitude of the relationships among the cognitive abilities and multitasking varied as a function of the complexity and structure of the various multitasks assessed. Finally, structural equation models based on a multifaceted model of WM indicated that attention control and capacity fully mediated the WM and multitasking relationship. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Deep Learning-Based Data Forgery Detection in Automatic Generation Control

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

Zhang, Fengli; Li, Qinghua

Automatic Generation Control (AGC) is a key control system in the power grid. It is used to calculate the Area Control Error (ACE) based on frequency and tie-line power flow between balancing areas, and then adjust power generation to maintain the power system frequency in an acceptable range. However, attackers might inject malicious frequency or tie-line power flow measurements to mislead AGC to do false generation correction which will harm the power grid operation. Such attacks are hard to be detected since they do not violate physical power system models. In this work, we propose algorithms based on Neural Networkmore » and Fourier Transform to detect data forgery attacks in AGC. Different from the few previous work that rely on accurate load prediction to detect data forgery, our solution only uses the ACE data already available in existing AGC systems. In particular, our solution learns the normal patterns of ACE time series and detects abnormal patterns caused by artificial attacks. Evaluations on the real ACE dataset show that our methods have high detection accuracy.« less

Motor cortical activity changes during neuroprosthetic-controlled object interaction.

PubMed

Downey, John E; Brane, Lucas; Gaunt, Robert A; Tyler-Kabara, Elizabeth C; Boninger, Michael L; Collinger, Jennifer L

2017-12-05

Brain-computer interface (BCI) controlled prosthetic arms are being developed to restore function to people with upper-limb paralysis. This work provides an opportunity to analyze human cortical activity during complex tasks. Previously we observed that BCI control became more difficult during interactions with objects, although we did not quantify the neural origins of this phenomena. Here, we investigated how motor cortical activity changed in the presence of an object independently of the kinematics that were being generated using intracortical recordings from two people with tetraplegia. After identifying a population-wide increase in neural firing rates that corresponded with the hand being near an object, we developed an online scaling feature in the BCI system that operated without knowledge of the task. Online scaling increased the ability of two subjects to control the robotic arm when reaching to grasp and transport objects. This work suggests that neural representations of the environment, in this case the presence of an object, are strongly and consistently represented in motor cortex but can be accounted for to improve BCI performance.

A Therapeutic Workplace for the Long-Term Treatment of Drug Addiction and Unemployment: Eight-Year Outcomes of a Social Business Intervention

PubMed Central

Aklin, Will M.; Wong, Conrad J.; Hampton, Jacqueline; Svikis, Dace S.; Stitzer, Maxine L.; Bigelow, George E.; Silverman, Kenneth

2014-01-01

This study evaluated the long-term effects of a Therapeutic Workplace social business on drug abstinence and employment. Pregnant and postpartum women (N=40) enrolled in methadone treatment were randomly assigned to a Therapeutic Workplace or Usual Care Control group. Therapeutic Workplace participants could work weekdays in training and then as employees of a social business, but were required to provide drug-free urine samples to work and maintain maximum pay. Three-year outcomes were reported previously. This paper reports 4- to 8- year outcomes. During year 4 when the business was open, Therapeutic Workplace participants provided significantly more cocaine- and opiate-negative urine samples than controls; reported more days employed, higher employment income, and less money spent on drugs. During the 3 years after the business closed, Therapeutic Workplace participants only reported higher income than controls. A Therapeutic Workplace social business can maintain long-term abstinence and employment, but additional intervention may be required to sustain effects. PMID:25124257

Silicon nanofin grating as a miniature chirality-distinguishing beam-splitter.

PubMed

Khorasaninejad, Mohammadreza; Crozier, Kenneth B

2014-11-12

The polarization of light plays a central role in its interaction with matter, in situations ranging from familiar (for example, reflection and transmission at an interface) to sophisticated (for example, nonlinear optics). Polarization control is therefore pivotal for many optical systems, and achieved using bulk devices such as wave-plates and beam-splitters. The move towards optical system miniaturization therefore motivates the development of micro- and nanostructures for polarization control. For such control to be complete, one must distinguish not only between linear polarizations, but also between left- and right-circular polarizations. Some previous works used surface plasmons to this end, but these are inherently lossy. Other works used complex-layered structures. Here we demonstrate a planar dielectric chirality-distinguishing beam-splitter. The beam-splitter consists of amorphous silicon nanofins on a glass substrate and deflects left- and right-circularly polarized beams into different directions. Contrary to intuitive expectations, we utilize an achiral architecture to realize a chiral beam-splitting functionality.

Neural network application to comprehensive engine diagnostics

NASA Technical Reports Server (NTRS)

Marko, Kenneth A.

1994-01-01

We have previously reported on the use of neural networks for detection and identification of faults in complex microprocessor controlled powertrain systems. The data analyzed in those studies consisted of the full spectrum of signals passing between the engine and the real-time microprocessor controller. The specific task of the classification system was to classify system operation as nominal or abnormal and to identify the fault present. The primary concern in earlier work was the identification of faults, in sensors or actuators in the powertrain system as it was exercised over its full operating range. The use of data from a variety of sources, each contributing some potentially useful information to the classification task, is commonly referred to as sensor fusion and typifies the type of problems successfully addressed using neural networks. In this work we explore the application of neural networks to a different diagnostic problem, the diagnosis of faults in newly manufactured engines and the utility of neural networks for process control.

Working memory capacity and controlled serial memory search.

PubMed

Mızrak, Eda; Öztekin, Ilke

2016-08-01

The speed-accuracy trade-off (SAT) procedure was used to investigate the relationship between working memory capacity (WMC) and the dynamics of temporal order memory retrieval. High- and low-span participants (HSs, LSs) studied sequentially presented five-item lists, followed by two probes from the study list. Participants indicated the more recent probe. Overall, accuracy was higher for HSs compared to LSs. Crucially, in contrast to previous investigations that observed no impact of WMC on speed of access to item information in memory (e.g., Öztekin & McElree, 2010), recovery of temporal order memory was slower for LSs. While accessing an item's representation in memory can be direct, recovery of relational information such as temporal order information requires a more controlled serial memory search. Collectively, these data indicate that WMC effects are particularly prominent during high demands of cognitive control, such as serial search operations necessary to access temporal order information from memory. Copyright © 2016 Elsevier B.V. All rights reserved.

Base Stock Policy in a Join-Type Production Line with Advanced Demand Information

NASA Astrophysics Data System (ADS)

Hiraiwa, Mikihiko; Tsubouchi, Satoshi; Nakade, Koichi

Production control such as the base stock policy, the kanban policy and the constant work-in-process policy in a serial production line has been studied by many researchers. Production lines, however, usually have fork-type, join-type or network-type figures. In addition, in most previous studies on production control, a finished product is required at the same time as arrival of demand at the system. Demand information is, however, informed before due date in practice. In this paper a join-type (assembly) production line under base stock control with advanced demand information in discrete time is analyzed. The recursive equations for the work-in-process are derived. The heuristic algorithm for finding appropriate base stock levels of all machines at short time is proposed and the effect of advanced demand information is examined by simulation with the proposed algorithm. It is shown that the inventory cost can decreases with little backlogs by using the appropriate amount of demand information and setting appropriate base stock levels.

Occupational solvent exposure and brain function: an fMRI study.

PubMed

Tang, Cheuk Ying; Carpenter, David M; Eaves, Emily L; Ng, Johnny; Ganeshalingam, Nimalya; Weisel, Clifford; Qian, Hua; Lange, Gudrun; Fiedler, Nancy L

2011-07-01

Deficits in cognitive function have been demonstrated among workers chronically exposed to solvents, but the neural basis for these deficits has not been shown. We used functional magnetic resonance imaging (fMRI) to compare pathophysiological changes in brain function between solvent-exposed and control workers. Painters, drywall tapers, and carpenters were recruited from the International Union of Painters and Allied Trades, District Council 9 in New York City and District Council 21 in Philadelphia, Pennsylvania, and from the Carpenters Union in New Jersey. Twenty-seven solvent-exposed and 27 control subjects of similar age, education, and occupational status completed the N-Back working memory test during fMRI. After controlling for confounders (age; lifetime marijuana, cocaine, and alcohol use; blood lead; symptoms of depression; verbal intelligence), voxelwise group analysis and regional activation levels were compared and then correlated with an index of lifetime solvent exposure. Solvent-exposed workers' performance on the N-Back was significantly worse than that of controls. Activation of the anterior cingulate, prefrontal, and parietal cortices--areas serving working memory function and attention--was also significantly lower for solvent-exposed workers relative to controls. After controlling for confounders, we observed a negative correlation between lifetime solvent exposure and activation in these same regions among the solvent-exposed workers. This study is one of the few to document neural structures affected by exposure to solvents. Our findings provide a biological mechanism for the neurobehavioral deficits in working memory and attention that have previously been reported by other groups studying the effects of chronic exposure to solvents. These imaging markers, which are consistent with the neurobehavioral measures in our subject population, are consistent with altered brain pathology caused by prolonged exposure to solvent mixtures during construction work.

Occupational Solvent Exposure and Brain Function: An fMRI Study

PubMed Central

Carpenter, David M.; Eaves, Emily L.; Ng, Johnny; Ganeshalingam, Nimalya; Weisel, Clifford; Qian, Hua; Lange, Gudrun; Fiedler, Nancy L.

2011-01-01

Background: Deficits in cognitive function have been demonstrated among workers chronically exposed to solvents, but the neural basis for these deficits has not been shown. Objectives: We used functional magnetic resonance imaging (fMRI) to compare pathophysiological changes in brain function between solvent-exposed and control workers. Methods: Painters, drywall tapers, and carpenters were recruited from the International Union of Painters and Allied Trades, District Council 9 in New York City and District Council 21 in Philadelphia, Pennsylvania, and from the Carpenters Union in New Jersey. Twenty-seven solvent-exposed and 27 control subjects of similar age, education, and occupational status completed the N-Back working memory test during fMRI. After controlling for confounders (age; lifetime marijuana, cocaine, and alcohol use; blood lead; symptoms of depression; verbal intelligence), voxelwise group analysis and regional activation levels were compared and then correlated with an index of lifetime solvent exposure. Results: Solvent-exposed workers’ performance on the N-Back was significantly worse than that of controls. Activation of the anterior cingulate, prefrontal, and parietal cortices—areas serving working memory function and attention—was also significantly lower for solvent-exposed workers relative to controls. After controlling for confounders, we observed a negative correlation between lifetime solvent exposure and activation in these same regions among the solvent-exposed workers. Conclusions: This study is one of the few to document neural structures affected by exposure to solvents. Our findings provide a biological mechanism for the neurobehavioral deficits in working memory and attention that have previously been reported by other groups studying the effects of chronic exposure to solvents. These imaging markers, which are consistent with the neurobehavioral measures in our subject population, are consistent with altered brain pathology caused by prolonged exposure to solvent mixtures during construction work. PMID:21296712

Cognitive Training Sustainably Improves Executive Functioning in Middle-Aged Industry Workers Assessed by Task Switching: A Randomized Controlled ERP Study

PubMed Central

Gajewski, Patrick D.; Freude, Gabriele; Falkenstein, Michael

2017-01-01

Recently, we reported results of a cross-sectional study investigating executive functions in dependence of aging and type of work. That study showed deficits in performance and electrophysiological activity in middle-aged workers with long-term repetitive and unchallenging work. Based on these findings, we conducted a longitudinal study that aimed at ameliorating these cognitive deficits by means of a trainer-guided cognitive training (CT) in 57 further middle-aged workers with repetitive type of work from the same factory. This study was designed as a randomized controlled trail with pre- (t1), post- (t2), and a 3-month follow-up (t3) measure. The waiting control group was trained between t2 and t3. The training lasted 3 months (20 sessions) and was evaluated with the same task switching paradigm used in the previous cross-sectional study. The CT improved performance in accuracy at the behavioral level and affected the electrophysiological correlates of retrieval of stimulus-response sets (P2), response selection (N2), and error detection (Ne), thus unveiling the neuronal background of the behavioral effects. The same training effects were observed in the waiting control group after CT at t3. Moreover, at t3, most of the behavioral and electrophysiological training-induced changes were found stable. Hence, CT appears to be an important intervention for compensating cognitive deficits in executive functions in middle-aged employees with cognitively unchallenging work. PMID:28275347

Exploring the relationship between personal control and the hospital environment.

PubMed

Williams, Anne M; Dawson, Sky; Kristjanson, Linda J

2008-06-01

This paper describes the further development of the substantive theory Optimising Personal Control to Facilitate Emotional Comfort. In previous work, emotional comfort was identified as a therapeutic state that was influenced by several factors, one of which was the hospital environment. This paper focuses on aspects within the hospital environment that patients perceive to influence their feelings of personal control. A relationship between control and health has been discussed in previous literature. There are indications that aspects of the hospital environment can impact on a patient's perception of control. This project explored personal control in relation to the hospital environment from the perspective of patients. Grounded theory method was used. Data were collected from patients' interviews and field observations and analysed using the constant comparative method. Interviews were tape-recorded and transcribed verbatim. A qualitative data computer program was used to manage the data. The results confirmed the findings of the original study where hospitalised patients were found to experience feelings of reduced personal control. The conditions of level of security, level of knowing and level of personal value were described in terms of their contribution to the patient's feelings of personal control. Specific directions for further research into the development and evaluation of therapeutic hospital environments that promote personal control and the associated emotional comfort are provided. This research highlights the importance of considering patients' feelings of personal control during their hospital stay. Several directions for establishment of therapeutic environments within hospitals are provided, but more research in this area is recommended.

Effect of Psychosocial Work Environment on Sickness Absence Among Patients Treated for Ischemic Heart Disease.

PubMed

Biering, Karin; Lund, Thomas; Andersen, Johan Hviid; Hjollund, Niels Henrik

2015-12-01

During the last decades mortality has declined in patients with coronary heart disease due to improvements in treatments and changes in life style, resulting in more people living with chronic heart disease. This implies that focus on rehabilitation and re-integration to the work-force becomes increasingly important. Previous studies among healthy workers suggest that the psychosocial working environment is associated with sickness absence. Whether the psychosocial working environment plays a role for patients with existing cardiovascular disease on return to work and sickness absence is less studied. A cohort of patients under 67 years and treated with percutaneous coronary intervention (PCI) was established in 2006. Three months after the procedure the patients (n = 625) answered a questionnaire about their psychosocial working environment. Patients were followed in registers for the following year. We examined the association between psychosocial working environment and sickness absence at 3 months, 1 year and new sick-listings during the first year with logistic regression. A total of 528 patients had returned to work 3 months after the PCI, while 97 was still sick-listed. After 1 year one was dead, 465 were working and 85 were receiving health related benefits, while 74 had left the workforce permanently. A number of 106 patients were sick-listed during the whole first year or had left the workforce permanently. After the initial return to work, 90 experienced a new sickness absence during the first year while the remaining 429 did not. High work pace, low commitment to the workplace, low recognition (rewards) and low job control were associated with sickness absence at 3 months, but not after 1 year. Low job control as well as job strain (combination of high demands and low control) was associated with new sick-listings. The psychosocial working environment was associated with sickness absence 3 months after the PCI, but not 1 year after.

In tobacco BY-2 cells xyloglucan oligosaccharides alter the expression of genes involved in cell wall metabolism, signalling, stress responses, cell division and transcriptional control.

PubMed

González-Pérez, Lien; Perrotta, Lara; Acosta, Alexis; Orellana, Esteban; Spadafora, Natasha; Bruno, Leonardo; Bitonti, Beatrice M; Albani, Diego; Cabrera, Juan Carlos; Francis, Dennis; Rogers, Hilary J

2014-10-01

Xyloglucan oligosaccharides (XGOs) are breakdown products of XGs, the most abundant hemicelluloses of the primary cell walls of non-Poalean species. Treatment of cell cultures or whole plants with XGOs results in accelerated cell elongation and cell division, changes in primary root growth, and a stimulation of defence responses. They may therefore act as signalling molecules regulating plant growth and development. Previous work suggests an interaction with auxins and effects on cell wall loosening, however their mode of action is not fully understood. The effect of an XGO extract from tamarind (Tamarindus indica) on global gene expression was therefore investigated in tobacco BY-2 cells using microarrays. Over 500 genes were differentially regulated with similar numbers and functional classes of genes up- and down-regulated, indicating a complex interaction with the cellular machinery. Up-regulation of a putative XG endotransglycosylase/hydrolase-related (XTH) gene supports the mechanism of XGO action through cell wall loosening. Differential expression of defence-related genes supports a role for XGOs as elicitors. Changes in the expression of genes related to mitotic control and differentiation also support previous work showing that XGOs are mitotic inducers. XGOs also affected expression of several receptor-like kinase genes and transcription factors. Hence, XGOs have significant effects on expression of genes related to cell wall metabolism, signalling, stress responses, cell division and transcriptional control.

A Dynamic Simulation of Musculoskeletal Function in the Mouse Hindlimb During Trotting Locomotion

PubMed Central

Charles, James P.; Cappellari, Ornella; Hutchinson, John R.

2018-01-01

Mice are often used as animal models of various human neuromuscular diseases, and analysis of these models often requires detailed gait analysis. However, little is known of the dynamics of the mouse musculoskeletal system during locomotion. In this study, we used computer optimization procedures to create a simulation of trotting in a mouse, using a previously developed mouse hindlimb musculoskeletal model in conjunction with new experimental data, allowing muscle forces, activation patterns, and levels of mechanical work to be estimated. Analyzing musculotendon unit (MTU) mechanical work throughout the stride allowed a deeper understanding of their respective functions, with the rectus femoris MTU dominating the generation of positive and negative mechanical work during the swing and stance phases. This analysis also tested previous functional inferences of the mouse hindlimb made from anatomical data alone, such as the existence of a proximo-distal gradient of muscle function, thought to reflect adaptations for energy-efficient locomotion. The results do not strongly support the presence of this gradient within the mouse musculoskeletal system, particularly given relatively high negative net work output from the ankle plantarflexor MTUs, although more detailed simulations could test this further. This modeling analysis lays a foundation for future studies of the control of vertebrate movement through the development of neuromechanical simulations. PMID:29868576

Composite pulses robust against charge noise and magnetic field noise for universal control of a singlet-triplet qubit

NASA Astrophysics Data System (ADS)

Wang, Xin; Barnes, Edwin; Kestner, Jason P.; Bishop, Lev S.; Das Sarma, Sankar

2013-03-01

We generalize our SUPCODE pulse sequences for singlet-triplet qubits to correct errors from imperfect control. This yields gates that are simultaneously corrected for both charge noise and magnetic field gradient fluctuations, addressing the two dominant T2* processes. By using this more efficient version of SUPCODE, we are able to introduce this capability while also substantially reducing the overall pulse time compared to the previous sequence. We show that our sequence remains realistic under experimental constraints such as finite bandwidth. This work is supported by LPS-NSA-CMTC, IARPA-MQCO and CNAM.

Dynamic optimization of ISR sensors using a risk-based reward function applied to ground and space surveillance scenarios

NASA Astrophysics Data System (ADS)

DeSena, J. T.; Martin, S. R.; Clarke, J. C.; Dutrow, D. A.; Newman, A. J.

2012-06-01

As the number and diversity of sensing assets available for intelligence, surveillance and reconnaissance (ISR) operations continues to expand, the limited ability of human operators to effectively manage, control and exploit the ISR ensemble is exceeded, leading to reduced operational effectiveness. Automated support both in the processing of voluminous sensor data and sensor asset control can relieve the burden of human operators to support operation of larger ISR ensembles. In dynamic environments it is essential to react quickly to current information to avoid stale, sub-optimal plans. Our approach is to apply the principles of feedback control to ISR operations, "closing the loop" from the sensor collections through automated processing to ISR asset control. Previous work by the authors demonstrated non-myopic multiple platform trajectory control using a receding horizon controller in a closed feedback loop with a multiple hypothesis tracker applied to multi-target search and track simulation scenarios in the ground and space domains. This paper presents extensions in both size and scope of the previous work, demonstrating closed-loop control, involving both platform routing and sensor pointing, of a multisensor, multi-platform ISR ensemble tasked with providing situational awareness and performing search, track and classification of multiple moving ground targets in irregular warfare scenarios. The closed-loop ISR system is fullyrealized using distributed, asynchronous components that communicate over a network. The closed-loop ISR system has been exercised via a networked simulation test bed against a scenario in the Afghanistan theater implemented using high-fidelity terrain and imagery data. In addition, the system has been applied to space surveillance scenarios requiring tracking of space objects where current deliberative, manually intensive processes for managing sensor assets are insufficiently responsive. Simulation experiment results are presented. The algorithm to jointly optimize sensor schedules against search, track, and classify is based on recent work by Papageorgiou and Raykin on risk-based sensor management. It uses a risk-based objective function and attempts to minimize and balance the risks of misclassifying and losing track on an object. It supports the requirement to generate tasking for metric and feature data concurrently and synergistically, and account for both tracking accuracy and object characterization, jointly, in computing reward and cost for optimizing tasking decisions.

Active Metamaterial Based Terahertz Polarimeter for Spectroscopic Detection of Chemical and Biological Hazards

DTIC Science & Technology

2014-04-01

13. SUPPLEMENTARY NOTES Author’s email: grace.d.metcalfe.civ@mail.mil 14. ABSTRACT Polarimetry is the analysis of the polarization state of...been virtually no polarimetry work at terahertz (THz) frequencies because, until recently, it has been difficult to create components to control the...develop the essential components such that THz polarimetry may enhance the ability to study previously unexploited spectral responses in the THz

Optimization of Extended Relational Database Systems

DTIC Science & Technology

1986-07-23

control functions are integrated into a single system in a homogeneoua way. As a first exam - ple, consider previous work in supporting various semantic...sizes are reduced and, wnk? quently, the number of materializations that will be needed is aba lower. For exam - pie, in the above query tuple...retrieve (EMP.name) where EMP hobbies instrument = ’ violin ’ When the various entries in the hobbies field are materialized, only those queries that

Competition between frontoparietal control and default networks supports social working memory and empathy

PubMed Central

Xin, Fei

2015-01-01

An extensive body of literature has indicated that there is increased activity in the frontoparietal control network (FPC) and decreased activity in the default mode network (DMN) during working memory (WM) tasks. The FPC and DMN operate in a competitive relationship during tasks requiring externally directed attention. However, the association between this FPC-DMN competition and performance in social WM tasks has rarely been reported in previous studies. To investigate this question, we measured FPC-DMN connectivity during resting state and two emotional face recognition WM tasks using the 2-back paradigm. Thirty-four individuals were instructed to perform the tasks based on either the expression [emotion (EMO)] or the identity (ID) of the same set of face stimuli. Consistent with previous studies, an increased anti-correlation between the FPC and DMN was observed during both tasks relative to the resting state. Specifically, this anti-correlation during the EMO task was stronger than during the ID task, as the former has a higher social load. Intriguingly, individual differences in self-reported empathy were significantly correlated with the FPC-DMN anti-correlation in the EMO task. These results indicate that the top-down signals from the FPC suppress the DMN to support social WM and empathy. PMID:25556209

Portion Size: Latest Developments and Interventions.

PubMed

Steenhuis, Ingrid; Poelman, Maartje

2017-03-01

The aim of this review is to provide an overview of (1) underlying mechanisms of the effect of portion size on energy intake, (2) external factors explaining the portion size effect and (3) interventions and measurements aimed at food portion size. Previous studies have shown that portion sizes have increased in recent decades. Many experimental studies have been conducted to unravel the mechanisms underlying the portion-size effect on food intake (e.g. the appropriateness mechanism, the 'unit bias' mechanism, the 'previous experience/expectation' mechanism, the 'visual cue' mechanism and the 'bite size' mechanism). In addition, external factors have been found to drive food portion selection and consumption (e.g. value for money, mindless eating, levels of awareness, estimation bias. Research on several interventions (ranging from 'providing information' to 'eliminating choice') have been conducted, but remain scarce, especially intervention studies in which portion size is a key focus in weight loss. Moreover, only three new instruments with respect to portion control behavior have been developed. There is considerable evidence for the portion-size effect on energy intake. However, the work on interventions targeting portion size and measurements for portion control behavior are limited. Moreover, from the literature it is not yet clear what type of interventions work best, for whom and in what context.

Eurasian otters, Lutra lutra, have a dominant mtDNA haplotype from the Iberian Peninsula to Scandinavia.

PubMed

Ferrando, Ainhoa; Ponsà, Montserrat; Marmi, Josep; Domingo-Roura, Xavier

2004-01-01

The Eurasian otter, Lutra lutra, has a Palaearctic distribution and has suffered a severe decline throughout Europe during the last century. Previous studies in this and other mustelids have shown reduced levels of variability in mitochondrial DNA, although otter phylogeographic studies were restricted to central-western Europe. In this work we have sequenced 361 bp of the mtDNA control region in 73 individuals from eight countries and added our results to eight sequences available from GenBank and the literature. The range of distribution has been expanded in relation to previous works north towards Scandinavia, east to Russia and Belarus, and south to the Iberian Peninsula. We found a single dominant haplotype in 91.78% of the samples, and six more haplotypes deviating a maximum of two mutations from the dominant haplotype restricted to a single country. Variability was extremely low in western Europe but higher in eastern countries. This, together with the lack of phylogeographical structuring, supports the postglacial recolonization of Europe from a single refugium. The Eurasian otter mtDNA control region has a 220-bp variable minisatellite in Domain III that we sequenced in 29 otters. We found a total of 19 minisatellite haplotypes, but they showed no phylogenetic information.

Characterization of a normal control group: are they healthy?

PubMed

Aine, C J; Sanfratello, L; Adair, J C; Knoefel, J E; Qualls, C; Lundy, S L; Caprihan, A; Stone, D; Stephen, J M

2014-01-01

We examined the health of a control group (18-81years) in our aging study, which is similar to control groups used in other neuroimaging studies. The current study was motivated by our previous results showing that one third of the elder control group had moderate to severe white matter hyperintensities and/or cortical volume loss which correlated with poor performance on memory tasks. Therefore, we predicted that cardiovascular risk factors (e.g., hypertension, high cholesterol) within the control group would account for significant variance on working memory task performance. Fifty-five participants completed 4 verbal and spatial working memory tasks, neuropsychological exams, diffusion tensor imaging (DTI), and blood tests to assess vascular risk. In addition to using a repeated measures ANOVA design, a cluster analysis was applied to the vascular risk measures as a data reduction step to characterize relationships between conjoint risk factors. The cluster groupings were used to predict working memory performance. The results show that higher levels of systolic blood pressure were associated with: 1) poor spatial working memory accuracy; and 2) lower fractional anisotropy (FA) values in multiple brain regions. In contrast, higher levels of total cholesterol corresponded with increased accuracy in verbal working memory. An association between lower FA values and higher cholesterol levels were identified in different brain regions from those associated with systolic blood pressure. The conjoint risk analysis revealed that Risk Cluster Group 3 (the group with the greatest number of risk factors) displayed: 1) the poorest performance on the spatial working memory tasks; 2) the longest reaction times across both spatial and verbal memory tasks; and 3) the lowest FA values across widespread brain regions. Our results confirm that a considerable range of vascular risk factors are present in a typical control group, even in younger individuals, which have robust effects on brain anatomy and function. These results present a new challenge to neuroimaging studies both for defining a cohort from which to characterize 'normative' brain circuitry and for establishing a control group to compare with other clinical populations. © 2013.

Measuring the mechanical efficiency of a working cardiac muscle sample at body temperature using a flow-through calorimeter.

PubMed

Taberner, Andrew J; Johnston, Callum M; Pham, Toan; June-Chiew Han; Ruddy, Bryan P; Loiselle, Denis S; Nielsen, Poul M F

2015-08-01

We have developed a new `work-loop calorimeter' that is capable of measuring, simultaneously, the work-done and heat production of isolated cardiac muscle samples at body temperature. Through the innovative use of thermoelectric modules as temperature sensors, the development of a low-noise fluid-flow system, and implementation of precise temperature control, the heat resolution of this device is 10 nW, an improvement by a factor of ten over previous designs. These advances have allowed us to conduct the first flow-through measurements of work output and heat dissipation from cardiac tissue at body temperature. The mechanical efficiency is found to vary with peak stress, and reaches a peak value of approximately 15 %, a figure similar to that observed in cardiac muscle at lower temperatures.

The impact of bilingualism on working memory in pediatric epilepsy

PubMed Central

Veenstra, Amy L.; Riley, Jeffrey D.; Barrett, Lauren E.; Muhonen, Michael G.; Zupanc, Mary; Romain, Jonathan E.; Lin, Jack J.; Mucci, Grace

2016-01-01

Impairments in executive skills broadly span across multiple childhood epilepsy syndromes and can adversely affect quality of life. Bilingualism has been previously shown to correlate with enhanced executive functioning in healthy individuals. This study seeks to determine whether the bilingual advantage in executive functioning exists in the context of pediatric epilepsy. We retrospectively analyzed neuropsychological data in 52 children with epilepsy and compared executive function scores in monolingual versus bilingual children with epilepsy, while controlling for socioeconomic status and ethnicity. Bilingual children performed significantly better on the Working Memory scale than did monolingual children. There were no significant differences on the remaining executive function variables. The bilingual advantage appears to persist for working memory in children with epilepsy. These findings suggest that bilingualism is potentially a protective variable in the face of epilepsy-related working memory dysfunction. PMID:26720703

Monitor design with multiple self-loops for maximally permissive supervisors.

PubMed

Chen, YuFeng; Li, ZhiWu; Barkaoui, Kamel; Uzam, Murat

2016-03-01

In this paper, we improve the previous work by considering that a control place can have multiple self-loops. Then, two integer linear programming problems (ILPPs) are formulated. Based on the first ILPP, an iterative deadlock control policy is developed, where a control place is computed at each iteration to implement as many marking/transition separation instances (MTSIs) as possible. The second ILPP can find a set of control places to implement all MTSIs and the objective function is used to minimize the number of control places. It is a non-iterative deadlock control strategy since we need to solve the ILPP only once. Both ILPPs can make all legal markings reachable in the controlled system, i.e., the obtained supervisor is behaviorally optimal. Finally, we provide examples to illustrate the proposed approaches. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Night work and breast cancer in women: a Swedish cohort study

PubMed Central

Åkerstedt, Torbjörn; Knutsson, Anders; Narusyte, Jurgita; Svedberg, Pia; Kecklund, Göran; Alexanderson, Kristina

2015-01-01

Objectives Recent research has suggested a moderate link between night work and breast cancer in women, mainly through case–control studies, but non-significant studies are also common and cohort studies are few. The purpose of the present study was to provide new information from cohort data through investigating the association between the number of years with night work and breast cancer among women. Design Cohort study of individuals exposed to night shift work in relation to incidence of breast cancer in women. Setting Individuals in the Swedish Twin registry, with follow-up in the Swedish Cancer Registry. Participants 13 656 women from the Swedish Twin Registry, with 3404 exposed to night work. Outcome measures Breast cancer from the Swedish Cancer Registry (463 cases) during a follow-up time of 12 years. Results A Cox proportional hazards regression analysis with control for a large number of confounders showed that the HR was HR=1.68 (95% CI 0.98 to 2.88) for the group with >20 years of night work. When the follow-up time was limited to ages below 60 years, those exposed >20 years showed a HR=1.77 (95% CI 1.03 to 3.04). Shorter exposure to night work showed no significant effects. Conclusions The present results, together with previous work, suggest that night work is associated with an increased risk of breast cancer in women, but only after relatively long-term exposure. PMID:25877283

The role of intrinsic muscle mechanics in the neuromuscular control of stable running in the guinea fowl

PubMed Central

Daley, Monica A; Voloshina, Alexandra; Biewener, Andrew A

2009-01-01

Here we investigate the interplay between intrinsic mechanical and neural factors in muscle contractile performance during running, which has been less studied than during walking. We report in vivo recordings of the gastrocnemius muscle of the guinea fowl (Numida meleagris), during the response and recovery from an unexpected drop in terrain. Previous studies on leg and joint mechanics following this perturbation suggested that distal leg extensor muscles play a key role in stabilisation. Here, we test this through direct recordings of gastrocnemius fascicle length (using sonomicrometry), muscle–tendon force (using buckle transducers), and activity (using indwelling EMG). Muscle recordings were analysed from the stride just before to the second stride following the perturbation. The gastrocnemius exhibits altered force and work output in the perturbed and first recovery strides. Muscle work correlates strongly with leg posture at the time of ground contact. When the leg is more extended in the drop step, net gastrocnemius work decreases (−5.2 J kg−1versus control), and when the leg is more flexed in the step back up, it increases (+9.8 J kg−1versus control). The muscle's work output is inherently stabilising because it pushes the body back toward its pre-perturbation (level running) speed and leg posture. Gastrocnemius length and force return to level running means by the second stride following the perturbation. EMG intensity differs significantly from level running only in the first recovery stride following the perturbation, not within the perturbed stride. The findings suggest that intrinsic mechanical factors contribute substantially to the initial changes in muscle force and work. The statistical results suggest that a history-dependent effect, shortening deactivation, may be an important factor in the intrinsic mechanical changes, in addition to instantaneous force–velocity and force–length effects. This finding suggests the potential need to incorporate history-dependent muscle properties into neuromechanical simulations of running, particularly if high muscle strains are involved and stability characteristics are important. Future work should test whether a Hill or modified Hill type model provides adequate prediction in such conditions. Interpreted in light of previous studies on walking, the findings support the concept of speed-dependent roles of reflex feedback. PMID:19359369

Identifying ADHD children using hemodynamic responses during a working memory task measured by functional near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Gu, Yue; Miao, Shuo; Han, Junxia; Liang, Zhenhu; Ouyang, Gaoxiang; Yang, Jian; Li, Xiaoli

2018-06-01

Objective. Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting children and adults. Previous studies found that functional near-infrared spectroscopy (fNIRS) can reveal significant group differences in several brain regions between ADHD children and healthy controls during working memory tasks. This study aimed to use fNIRS activation patterns to identify ADHD children from healthy controls. Approach. FNIRS signals from 25 ADHD children and 25 healthy controls performing the n-back task were recorded; then, multivariate pattern analysis was used to discriminate ADHD individuals from healthy controls, and classification performance was evaluated for significance by the permutation test. Main results. The results showed that 86.0% (p<0.001 ) of participants can be correctly classified in leave-one-out cross-validation. The most discriminative brain regions included the bilateral dorsolateral prefrontal cortex, inferior medial prefrontal cortex, right posterior prefrontal cortex, and right temporal cortex. Significance. This study demonstrated that, in a small sample, multivariate pattern analysis can effectively identify ADHD children from healthy controls based on fNIRS signals, which argues for the potential utility of fNIRS in future assessments.

Preventing academic difficulties in preterm children: a randomised controlled trial of an adaptive working memory training intervention - IMPRINT study.

PubMed

Pascoe, Leona; Roberts, Gehan; Doyle, Lex W; Lee, Katherine J; Thompson, Deanne K; Seal, Marc L; Josev, Elisha K; Nosarti, Chiara; Gathercole, Susan; Anderson, Peter J

2013-09-16

Very preterm children exhibit difficulties in working memory, a key cognitive ability vital to learning information and the development of academic skills. Previous research suggests that an adaptive working memory training intervention (Cogmed) may improve working memory and other cognitive and behavioural domains, although further randomised controlled trials employing long-term outcomes are needed, and with populations at risk for working memory deficits, such as children born preterm.In a cohort of extremely preterm (<28 weeks' gestation)/extremely low birthweight (<1000 g) 7-year-olds, we will assess the effectiveness of Cogmed in improving academic functioning 2 years' post-intervention. Secondary objectives are to assess the effectiveness of Cogmed in improving working memory and attention 2 weeks', 12 months' and 24 months' post-intervention, and to investigate training related neuroplasticity in working memory neural networks 2 weeks' post-intervention. This double-blind, placebo-controlled, randomised controlled trial aims to recruit 126 extremely preterm/extremely low birthweight 7-year-old children. Children attending mainstream school without major intellectual, sensory or physical impairments will be eligible. Participating children will undergo an extensive baseline cognitive assessment before being randomised to either an adaptive or placebo (non-adaptive) version of Cogmed. Cogmed is a computerised working memory training program consisting of 25 sessions completed over a 5 to 7 week period. Each training session takes approximately 35 minutes and will be completed in the child's home. Structural, diffusion and functional Magnetic Resonance Imaging, which is optional for participants, will be completed prior to and 2 weeks following the training period. Follow-up assessments focusing on academic skills (primary outcome), working memory and attention (secondary outcomes) will be conducted at 2 weeks', 12 months' and 24 months' post-intervention. To our knowledge, this study will be the first randomised controlled trial to (a) assess the effectiveness of Cogmed in school-aged extremely preterm/extremely low birthweight children, while incorporating advanced imaging techniques to investigate neural changes associated with adaptive working memory training, and (b) employ long-term follow-up to assess the potential benefit of improved working memory on academic functioning. If effective, Cogmed would serve as a valuable, available intervention for improving developmental outcomes for this population. Australian New Zealand Clinical Trials Registry ACTRN12612000124831.

Completion of the LANSCE Proton Storage Ring Control System Upgrade -- A Successful Integration of EPICS Into a Running Control System

NASA Astrophysics Data System (ADS)

Schaller, S. C.; Bjorklund, E. A.; Carr, G. P.; Faucett, J. A.; Oothoudt, M. A.

1997-05-01

The Los Alamos Neutron Scattering Center (LANSCE) Proton Storage Ring (PSR) control system upgrade was completed in 1996. In previous work, much of a PDP-11-based control system was replaced with Experimental Physics and Industrial Control System (EPICS) controls. Several parts of the old control system which used a VAX for operator displays and direct access to a CAMAC serial highway still remained. The old system was preserved as a "fallback" if the new EPICS-based system had problems. The control system upgrade completion included conversion of several application programs to EPICS-based operator interfaces, moving some data acquisition hardware to EPICS Input-Output Controllers (IOCs), and the implementation of new gateway software to complete the overall control system interoperability. Many operator interface (OPI) screens, written by LANSCE operators, have been incorporated in the new system. The old PSR control system hardware was removed. The robustness and reliability of the new controls obviated the need for a fallback capability.

Crewmember and mission control personnel interactions during International Space Station missions.

PubMed

Kanas, Nick A; Salnitskiy, Vyacheslav P; Boyd, Jennifer E; Gushin, Vadim I; Weiss, Daniel S; Saylor, Stephanie A; Kozerenko, Olga P; Marmar, Charles R

2007-06-01

Reports from astronauts and cosmonauts, studies from space analogue environments on Earth, and our previous research on the Mir Space Station have identified a number of psychosocial issues that can lead to problems during long-duration space missions. Three of these issues (time effects, displacement, leader role) were studied during a series of long-duration missions to the International Space Station (ISS). As in our previous Mir study, mood and group climate questions from the Profile of Mood States or POMS, the Group Environment Scale or GES, and the Work Environment Scale or WES were completed weekly by 17 ISS crewmembers (15 men, 2 women) in space and 128 American and Russian personnel in mission control. The results did not support the presence of decrements in mood and group cohesion during the 2nd half of the missions or in any specific quarter. The results did support the predicted displacement of negative feelings to outside supervisors in both crew and mission control subjects on all six questionnaire subscales tested. Crewmembers related cohesion in their group to the support role of their commander. For mission control personnel, greater cohesion was linked to the support role as well as to the task role of their leader. The findings from our previous study on the Mir Space Station were essentially replicated on board the ISS. The findings suggest a number of countermeasures for future on-orbit missions, some of which may not be relevant for expeditionary missions (e.g., to Mars).

[Symptoms related to the use of agricultural pesticides. The perspective from the primary care service].

PubMed

Subías Lorén, P J; Salvador Milian, M A; Moragues Farràs, C; Casanova Sandoval, J M; Marina Ortega, V

1995-12-01

To find whether agricultural workers seen in the general medical clinic attend due to symptoms connected with the use of pesticides. A crossover descriptive study comparing agricultural workers with a control group. Primary care. The clinical histories of 40 agricultural workers and a control group (sample of 58 paired for age and gender) who had been seen over the previous year. Age, gender, frequency of attendance, motives for consultation, risk factors and the number of consultations for symptoms possibly due to exposure to pesticides--in line with a previously composed list. There were no differences in frequency of attendance, overall reasons for consultation or risk factors. It was seen that agricultural workers consulted 4 times more than the control group for suspected pesticide poisoning (p = 0.0015). In our health area agricultural workers present symptoms which should probably be attributed to insufficient protection against pesticides. The primary care doctor working in rural zones where these products are heavily used must be able to identify these symptoms and take appropriate measures.

How Distinctive Processing Enhances Hits and Reduces False Alarms

PubMed Central

Hunt, R. Reed; Smith, Rebekah E.

2015-01-01

Distinctive processing is a concept designed to account for precision in memory, both correct responses and avoidance of errors. The principal question addressed in two experiments is how distinctive processing of studied material reduces false alarms to familiar distractors. Jacoby (Jacoby, Kelley, & McElree, 1999) has used the metaphors early selection and late correction to describe two different types of control processes. Early selection refers to limitations on access whereas late correction describes controlled monitoring of accessed information. The two types of processes are not mutually exclusive, and previous research has provided evidence for the operation of both. The data reported here extend previous work to a criterial recollection paradigm and to a recognition memory test. The results of both experiments show that variables that reduce false memory for highly familiar distracters continue to exert their effect under conditions of minimal post-access monitoring. Level of monitoring was reduced in the first experiment through test instructions and in the second experiment through speeded test responding. The results were consistent with the conclusion that both early selection and late correction operate to control accuracy in memory. PMID:26034343

Increased incidence of chromosomal aberrations in peripheral lymphocytes of retired nickel workers.

PubMed

Waksvik, H; Boysen, M; Høgetveit, A C

1984-11-01

Chromosomal aberrations and sister chromatid exchanges were analysed in the peripheral lymphocytes of nine retired nickel refinery workers 4-15 years after the retirement and compared with 11 matched non-nickel exposed controls. None of the controls had previous occupations with known relation to induction of chromosomal aberrations nor sister chromatid exchanges. The groups were equal as to socioeconomic status and environmental factors other than the occupational ones, which could influence the chromosome parameters, were to the largest possible extent excluded. The nickel workers' previous occupational employment involved exposure to inhalation of furnace dust of Ni3S2 and NiO or aerosols of NiCl2 and NiSO4. The concentration of nickel in the working atmospheres has been higher than 1.0 mg/m3 air and the exposure time more than 25 years. The retired nickel workers showed an increased incidence of breaks (p less than 0.001) and gaps (p less than 0.05) but no difference in the incidence of sister chromatid exchanges when compared with the controls.

Communication analysis for feedback control of civil infrastructure using cochlea-inspired sensing nodes

NASA Astrophysics Data System (ADS)

Peckens, Courtney A.; Cook, Ireana; Lynch, Jerome P.

2016-04-01

Wireless sensor networks (WSNs) have emerged as a reliable, low-cost alternative to the traditional wired sensing paradigm. While such networks have made significant progress in the field of structural monitoring, significantly less development has occurred for feedback control applications. Previous work in WSNs for feedback control has highlighted many of the challenges of using this technology including latency in the wireless communication channel and computational inundation at the individual sensing nodes. This work seeks to overcome some of those challenges by drawing inspiration from the real-time sensing and control techniques employed by the biological central nervous system and in particular the mammalian cochlea. A novel bio-inspired wireless sensor node was developed that employs analog filtering techniques to perform time-frequency decomposition of a sensor signal, thus encompassing the functionality of the cochlea. The node then utilizes asynchronous sampling of the filtered signal to compress the signal prior to communication. This bio-inspired sensing architecture is extended to a feedback control application in order to overcome the traditional challenges currently faced by wireless control. In doing this, however, the network experiences high bandwidths of low-significance information exchange between nodes, resulting in some lost data. This study considers the impact of this lost data on the control capabilities of the bio-inspired control architecture and finds that it does not significantly impact the effectiveness of control.

The Absolute Stability Analysis in Fuzzy Control Systems with Parametric Uncertainties and Reference Inputs

NASA Astrophysics Data System (ADS)

Wu, Bing-Fei; Ma, Li-Shan; Perng, Jau-Woei

This study analyzes the absolute stability in P and PD type fuzzy logic control systems with both certain and uncertain linear plants. Stability analysis includes the reference input, actuator gain and interval plant parameters. For certain linear plants, the stability (i.e. the stable equilibriums of error) in P and PD types is analyzed with the Popov or linearization methods under various reference inputs and actuator gains. The steady state errors of fuzzy control systems are also addressed in the parameter plane. The parametric robust Popov criterion for parametric absolute stability based on Lur'e systems is also applied to the stability analysis of P type fuzzy control systems with uncertain plants. The PD type fuzzy logic controller in our approach is a single-input fuzzy logic controller and is transformed into the P type for analysis. In our work, the absolute stability analysis of fuzzy control systems is given with respect to a non-zero reference input and an uncertain linear plant with the parametric robust Popov criterion unlike previous works. Moreover, a fuzzy current controlled RC circuit is designed with PSPICE models. Both numerical and PSPICE simulations are provided to verify the analytical results. Furthermore, the oscillation mechanism in fuzzy control systems is specified with various equilibrium points of view in the simulation example. Finally, the comparisons are also given to show the effectiveness of the analysis method.

Exposure to urban stressor and effects on free testosterone in female workers.

PubMed

Tomei, Gianfranco; Ciarrocca, Manuela; Fiore, Pina; Rosati, Maria Valeria; Pimpinella, Benedetta; Anzani, Maria Francesca; Giubilati, Roberto; Cangemi, Chiara; Tomao, Enrico; Tomei, Francesco

2008-03-25

The aim of the study is to evaluate if occupational exposure to chemical, physical and psycho-social urban stressor could cause alterations in plasma free testosterone (T) levels and related diseases in female traffic police vs. control group. The research was carried out on initial sample of 468 female Municipal Police employees (209 traffic police and 259 controls). After excluding the principal confounding factors, traffic police were matched with controls by age, working life, menstrual cycle day, BMI, drinking habit, cigarette smoking habit, liquorice and soy intake in diet, habitual consumption of Italian coffee. There were 96 female traffic police and 96 controls included in the study. T mean levels were significantly higher in female traffic police compared to controls (p=0.000). The distribution of T values in traffic police and in controls was significant (p=0.000). No significant differences were found comparing the percentage in traffic police and controls concerning dystocial, premature and post-term birth. An increase in mental health disorders was found in traffic police compared to controls but the difference was not significant. The increase in T plasma levels observed in traffic police vs. controls can be due to a chronic working exposure to low doses of environmental chemical urban stressor. According to our previous researches T could be used as an early biological marker even before the onset of the related disorders.

Health-related effects of early part-time sick leave due to musculoskeletal disorders: a randomized controlled trial.

PubMed

Shiri, Rahman; Kausto, Johanna; Martimo, Kari-Pekka; Kaila-Kangas, Leena; Takala, Esa-Pekka; Viikari-Juntura, Eira

2013-01-01

Previously we reported that early part-time sick leave enhances return to work (RTW) among employees with musculoskeletal disorders (MSD). This paper assesses the health-related effects of this intervention. Patients aged 18-60 years who were unable to perform their regular work due to MSD were randomized to part- or full-time sick leave groups. In the former, workload was reduced by halving working time. Using validated questionnaires, we assessed pain intensity and interference with work and sleep, region-specific disability due to MSD, self-rated general health, health-related quality of life (measured via EuroQol), productivity loss, depression, and sleep disturbance at baseline, 1, 3, 8, 12, and 52 weeks. We analyzed the repeated measures data (171-356 observations) with the generalized estimating equation approach. The intervention (part-time sick leave) and control (full-time sick leave) groups did not differ with regard to pain intensity, pain interference with work and sleep, region-specific disability, productivity loss, depression, or sleep disturbance. The intervention group reported better self-rated general health (adjusted P=0.07) and health-related quality of life (adjusted P=0.02) than the control group. In subgroup analyses, the intervention was more effective among the patients whose current problem began occurring <6 weeks before baseline and those with ≤30% productivity loss at baseline. Our findings showed that part-time sick leave did not exacerbate pain-related symptoms and functional disability, but improved self-rated general health and health-related quality of life in the early stage of work disability due to MSD.

Energy efficiency technologies in cement and steel industry

NASA Astrophysics Data System (ADS)

Zanoli, Silvia Maria; Cocchioni, Francesco; Pepe, Crescenzo

2018-02-01

In this paper, Advanced Process Control strategies aimed at energy efficiency achievement and improvement in cement and steel industry are proposed. A flexible and smart control structure constituted by several functional modules and blocks has been developed. The designed control strategy is based on Model Predictive Control techniques, formulated on linear models. Two industrial control solutions have been developed, oriented to energy efficiency and process control improvement in cement industry clinker rotary kilns (clinker production phase) and in steel industry billets reheating furnaces. Tailored customization procedures for the design of ad hoc control systems have been executed, based on the specific needs and specifications of the analysed processes. The installation of the developed controllers on cement and steel plants produced significant benefits in terms of process control which resulted in working closer to the imposed operating limits. With respect to the previous control systems, based on local controllers and/or operators manual conduction, more profitable configurations of the crucial process variables have been provided.

An fMRI investigation of cerebellar function during verbal working memory in methadone maintenance patients.

PubMed

Marvel, Cherie L; Faulkner, Monica L; Strain, Eric C; Mintzer, Miriam Z; Desmond, John E

2012-03-01

Working memory is impaired in opioid-dependent individuals, yet the neural underpinnings of working memory in this population are largely unknown. Previous studies in healthy adults have demonstrated that working memory is supported by a network of brain regions that includes a cerebro-cerebellar circuit. The cerebellum, in particular, may be important for inner speech mechanisms that assist verbal working memory. This study used functional magnetic resonance imaging to examine brain activity associated with working memory in five opioid-dependent, methadone-maintained patients and five matched, healthy controls. An item recognition task was administered in two conditions: (1) a low working memory load "match" condition in which participants determined whether target letters presented at the beginning of the trial matched a probe item, and (2) a high working memory load "manipulation" condition in which participants counted two alphabetical letters forward of each of the targets and determined whether either of these new items matched a probe item. Response times and accuracy scores were not significantly different between the groups. FMRI analyses indicated that, in association with higher working memory load ("manipulation" condition), the patient group exhibited hyperactivity in the superior and inferior cerebellum and amygdala relative to that of controls. At a more liberal statistical threshold, patients exhibited hypoactivity in the left prefrontal and medial frontal/pre-SMA regions. These results indicate that verbal working memory in opioid-dependent individuals involves a disrupted cerebro-cerebellar circuit and shed light on the neuroanatomical basis of working memory impairments in this population.

An fMRI Investigation of Cerebellar Function During Verbal Working Memory in Methadone Maintenance Patients

PubMed Central

Marvel, Cherie L.; Faulkner, Monica L.; Strain, Eric C.; Mintzer, Miriam Z.; Desmond, John E.

2011-01-01

Working memory is impaired in opioid-dependent individuals, yet the neural underpinnings of working memory in this population are largely unknown. Previous studies in healthy adults have demonstrated that working memory is supported by a network of brain regions that includes a cerebro-cerebellar circuit. The cerebellum, in particular, may be important for inner speech mechanisms that assist verbal working memory. This study used functional magnetic resonance imaging (fMRI) to examine brain activity associated with working memory in 5 opioid-dependent, methadone-maintained patients and 5 matched, healthy controls. An item recognition task was administered in two conditions: 1) a low working memory load “match” condition in which participants determined whether target letters presented at the beginning of the trial matched a probe item, and 2) a high working memory load “manipulation” condition in which participants counted two alphabetical letters forward of each of the targets and determined whether either of these new items matched a probe item. Response times and accuracy scores were not significantly different between the groups. FMRI analyses indicated that, in association with higher working memory load (“manipulation” condition), the patient group exhibited hyperactivity in the superior and inferior cerebellum and amygdala relative to that of controls. At a more liberal statistical threshold, patients exhibited hypoactivity in the left prefrontal and medial frontal/pre-SMA regions. These results indicate that verbal working memory in opioid-dependent individuals involves a disrupted cerebro-cerebellar circuit, and shed light on the neuroanatomical basis of working memory impairments in this population. PMID:21892700

Working conditions in mid-life and mental health in older ages.

PubMed

Wahrendorf, Morten; Blane, David; Bartley, Mel; Dragano, Nico; Siegrist, Johannes

2013-03-01

This article illustrates the importance of previous working conditions during mid-life (between 40 and 55) for mental health among older retired men and women (60 or older) across 13 European countries. We link information on health from the second wave (2006-2007) of the Survey of Health, Ageing and Retirement in Europe (SHARE) with information on respondents' working life collected retrospectively in the SHARELIFE interview (2008-2009). To measure working conditions, we rely on core assumptions of existing theoretical models of work stress (the demand-control-support and the effort-reward imbalance model) and distinguish four types of unhealthy working conditions: (1) a stressful psychosocial work environment (as assessed by the two work stress models) (2) a disadvantaged occupational position throughout the whole period of mid-life, (3) experience of involuntary job loss, and (4) exposure to job instability. Health after labour market exit is measured using depressive symptoms, as measured by the EURO-D depression scale. Main results show that men and women who experienced psychosocial stress at work or had low occupational positions during mid-life had significantly higher probabilities of high depressive symptoms during retirement. Additionally, men with unstable working careers and an involuntary job loss were at higher risks to report high depressive symptoms in later life. These associations remain significant after controlling for workers' health and social position prior mid-life. These findings support the assumption that mental health of retirees who experienced poor working conditions during mid-life is impaired. Copyright © 2012 Elsevier Ltd. All rights reserved.

Construct validity of the Work Productivity and Activity Impairment questionnaire across informal caregivers of chronically ill older patients.

PubMed

Giovannetti, Erin R; Wolff, Jennifer L; Frick, Kevin D; Boult, Chad

2009-09-01

To assess the validity of the Work Productivity and Activity Impairment questionnaire as adapted for caregiving (WPAI:CG) to measure productivity loss (hours missed from work, impairment while at work, and impairment in regular activities) due to unpaid caregiving for medically complex older adults. The WPAI:CG was administered along with the Caregiver Strain Index (CSI) and Center for Epidemiologic Studies Depression Scale (CESD) to a caregiving population (N = 308) enrolled with their older, medically complex care-recipient in a cluster-randomized controlled study. Correlation coefficients were calculated between each productivity variable derived from the WPAI:CG and CSI/CESD scores. Nonparametric tests for trend across ordered groups were carried out to examine the relationship between each productivity variable and the intensity of the caregiving. Significant positive correlations were found between work productivity loss and caregiving-related strain (r = 0.45) and depression (r = 0.30). Measures of productivity loss were also highly associated with caregiving intensity (P < 0.05) and care-recipient medical care use (P < 0.05). The average employed caregiver reported 1.5 hours absence from work in the previous week and 18.5% reduced productivity while at work due to caregiving. Employed and nonemployed caregivers reported 27.2% reduced productivity in regular activities in the previous week. The results indicate high convergent validity of the WPAI:CG questionnaire. This measure could facilitate research on the cost-effectiveness of caregiver-workplace interventions and provide employers and policy experts with a more accurate and comprehensive estimate of caregiving-related costs incurred by employers and society.

The Component Model of Infrastructure: A Practical Approach to Understanding Public Health Program Infrastructure

PubMed Central

Snyder, Kimberly; Rieker, Patricia P.

2014-01-01

Functioning program infrastructure is necessary for achieving public health outcomes. It is what supports program capacity, implementation, and sustainability. The public health program infrastructure model presented in this article is grounded in data from a broader evaluation of 18 state tobacco control programs and previous work. The newly developed Component Model of Infrastructure (CMI) addresses the limitations of a previous model and contains 5 core components (multilevel leadership, managed resources, engaged data, responsive plans and planning, networked partnerships) and 3 supporting components (strategic understanding, operations, contextual influences). The CMI is a practical, implementation-focused model applicable across public health programs, enabling linkages to capacity, sustainability, and outcome measurement. PMID:24922125

Achieving TASAR Operational Readiness

NASA Technical Reports Server (NTRS)

Wing, David J.

2015-01-01

NASA has been developing and testing the Traffic Aware Strategic Aircrew Requests (TASAR) concept for aircraft operations featuring a NASA-developed cockpit automation tool, the Traffic Aware Planner (TAP), which computes traffic/hazard-compatible route changes to improve flight efficiency. The TAP technology is anticipated to save fuel and flight time and thereby provide immediate and pervasive benefits to the aircraft operator, as well as improving flight schedule compliance, passenger comfort, and pilot and controller workload. Previous work has indicated the potential for significant benefits for TASAR-equipped aircraft, and a flight trial of the TAP software application in the National Airspace System has demonstrated its technical viability. This paper reviews previous and ongoing activities to prepare TASAR for operational use.

Performance analysis of the toroidal field ITER production conductors

NASA Astrophysics Data System (ADS)

Breschi, M.; Macioce, D.; Devred, A.

2017-05-01

The production of the superconducting cables for the toroidal field (TF) magnets of the ITER machine has recently been completed at the manufacturing companies selected during the previous qualification phase. The quality assurance/quality control programs that have been implemented to ensure production uniformity across numerous suppliers include performance tests of several conductor samples from selected unit lengths. The short full-size samples (4 m long) were subjected to DC and AC tests in the SULTAN facility at CRPP in Villigen, Switzerland. In a previous work the results of the tests of the conductor performance qualification samples were reported. This work reports the analyses of the results of the tests of the production conductor samples. The results reported here concern the values of current sharing temperature, critical current, effective strain and n-value from the DC tests and the energy dissipated per cycle from the AC loss tests. A detailed comparison is also presented between the performance of the conductors and that of their constituting strands.

Design and Integration of an All-Magnetic Attitude Control System for FASTSAT-HSV01's Multiple Pointing Objectives

NASA Technical Reports Server (NTRS)

DeKock, Brandon; Sanders, Devon; Vanzwieten, Tannen; Capo-Lugo, Pedro

2011-01-01

The FASTSAT-HSV01 spacecraft is a microsatellite with magnetic torque rods as it sole attitude control actuator. FASTSAT s multiple payloads and mission functions require the Attitude Control System (ACS) to maintain Local Vertical Local Horizontal (LVLH)-referenced attitudes without spin-stabilization, while the pointing errors for some attitudes be significantly smaller than the previous best-demonstrated for this type of control system. The mission requires the ACS to hold multiple stable, unstable, and non-equilibrium attitudes, as well as eject a 3U CubeSat from an onboard P-POD and recover from the ensuing tumble. This paper describes the Attitude Control System, the reasons for design choices, how the ACS integrates with the rest of the spacecraft, and gives recommendations for potential future applications of the work.

Burnout in the working population: relations to psychosocial work factors.

PubMed

Lindblom, Karin M; Linton, Steven J; Fedeli, Cecilia; Bryngelsson, Ing-Liss

2006-01-01

This study investigated levels of burnout in the general population irrespective of occupation and relations between burnout and psychosocial work factors. A cross-sectional survey featuring sleep problems, psychological distress, burnout (Maslach Burnout Inventory-General Survey), and psychosocial factors at work, was mailed to a random sample of 3,000 participants, aged 20-60. Response rate was 61%. A high level (18%), a low level (19%), and an intermediate group (63%) for burnout were constructed. The high level group was associated with those who were > 50 years old, women, those experiencing psychological distress, and those with a poor psychosocial work climate. The analyses on variables significant in previous analyses showed that the high level group was strongly related to high demands, low control, lack of social support, and disagreeing about values at the workplace even when accounting for age, gender, and psychological distress. We conclude that psychosocial work factors are important in association to burnout regardless of occupation.

Stopping the past from intruding the present: Social anxiety disorder and proactive interference.

PubMed

Moore, Harry T A; Gómez-Ariza, Carlos J; Garcia-Lopez, Luis-Joaquín

2016-04-30

It has recently been suggested that social anxiety disorder (SAD) entails a deficit in downregulating unwanted (even non-threatening) memories. In the present study we test this hypothesis by comparing a sample of young adults diagnosed with SAD and healthy controls in their ability to resist proactive interference in a working memory task. Where participants performed similarly in the control condition of the memory task, participants with SAD were more susceptible to interference in the experimental condition than the healthy controls. This finding is in line with previous studies that show anxiety to be associated with impoverished executive control and, specifically, suggests that SAD entails a reduced ability to get rid of interfering memories. Clinical implications are discussed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

How to mathematically optimize drug regimens using optimal control.

PubMed

Moore, Helen

2018-02-01

This article gives an overview of a technique called optimal control, which is used to optimize real-world quantities represented by mathematical models. I include background information about the historical development of the technique and applications in a variety of fields. The main focus here is the application to diseases and therapies, particularly the optimization of combination therapies, and I highlight several such examples. I also describe the basic theory of optimal control, and illustrate each of the steps with an example that optimizes the doses in a combination regimen for leukemia. References are provided for more complex cases. The article is aimed at modelers working in drug development, who have not used optimal control previously. My goal is to make this technique more accessible in the biopharma community.

High Reynolds Number Hybrid Laminar Flow Control (HLFC) Flight Experiment. Report 4; Suction System Design and Manufacture

NASA Technical Reports Server (NTRS)

1999-01-01

This document describes the design of the leading edge suction system for flight demonstration of hybrid laminar flow control on the Boeing 757 airplane. The exterior pressures on the wing surface and the required suction quantity and distribution were determined in previous work. A system consisting of porous skin, sub-surface spanwise passages ("flutes"), pressure regulating screens and valves, collection fittings, ducts and a turbocompressor was defined to provide the required suction flow. Provisions were also made for flexible control of suction distribution and quantity for HLFC research purposes. Analysis methods for determining pressure drops and flow for transpiration heating for thermal anti-icing are defined. The control scheme used to observe and modulate suction distribution in flight is described.

Resilience and well-being amongst seafarers: cross-sectional study of crew across 51 ships.

PubMed

Doyle, Niamh; MacLachlan, Malcolm; Fraser, Alistair; Stilz, Ralf; Lismont, Karlien; Cox, Henriette; McVeigh, Joanne

2016-02-01

Duration at sea was investigated as a potential chronic stressor amongst seafarers in addition to the mediating roles of previous seafaring experience and hardiness between duration and stress. In a cross-sectional design, questionnaires were emailed to 53 tanker vessels in an international shipping company with questions relating to duration at sea, perceived stress, personality hardiness and work characteristics. The sample comprised 387 seafarers (98% male) including ratings, crew, officers, engineers, and catering staff that had been on board their ship between 0 and 24 weeks. Duration at sea was unrelated to self-reported perceived stress, even after controlling for previous seafaring experience and hardiness. Additional regression analyses demonstrated that self-reported higher levels of resilience, longer seafaring experience and greater instrumental work support were significantly associated with lower levels of self-reported stress at sea. These results imply that at least for the first 24 weeks at sea, exposure to the seafaring environment did not act as a chronic stressor. The confined environment of a ship presents particular opportunities to introduce resilience and work support programmes to help seafarers manage and reduce stress, and to enhance their well-being at sea.

Return to work after early part-time sick leave due to musculoskeletal disorders: a randomized controlled trial.

PubMed

Viikari-Juntura, Eira; Kausto, Johanna; Shiri, Rahman; Kaila-Kangas, Leena; Takala, Esa-Pekka; Karppinen, Jaro; Miranda, Helena; Luukkonen, Ritva; Martimo, Kari-Pekka

2012-03-01

The purpose of this study was to assess the effects of early part-time sick leave on return to work (RTW) and sickness absence among patients with musculoskeletal disorders. A randomized controlled trial was conducted in six occupational health units of medium- and large-size enterprises. Patients aged 18-60 years with musculoskeletal disorders (N=63) unable to perform their regular work were randomly allocated to part- or full-time sick leave. In the former group, workload was reduced by restricting work time by about a half. Remaining work tasks were modified when necessary, as specified in a "fit note" from the physician. The main outcomes were time to return to regular work activities and sickness absence during 12-month follow-up. Time to RTW sustained for ≥4 weeks was shorter in the intervention group (median 12 versus 20 days, P=0.10). Hazard ratio of RTW adjusted for age was 1.60 [95% confidence interval (95% CI) 0.98-2.63] and 1.76 (95% CI 1.21-2.56) after further adjustment for pain interference with sleep and previous sickness absence at baseline. Total sickness absence during the 12-month follow-up was about 20% lower in the intervention than the control group. Compliance with the intervention was high with no discontinuations of part-time sick leave due to musculoskeletal reasons. Early part-time sick leave may provide a faster and more sustainable return to regular duties than full-time sick leave among patients with musculoskeletal disorders. This is the first study to show that work participation can be safely increased with early part-time sick leave.

Terminology tools: state of the art and practical lessons.

PubMed

Cimino, J J

2001-01-01

As controlled medical terminologies evolve from simple code-name-hierarchy arrangements, into rich, knowledge-based ontologies of medical concepts, increased demands are placed on both the developers and users of the terminologies. In response, researchers have begun developing tools to address their needs. The aims of this article are to review previous work done to develop these tools and then to describe work done at Columbia University and New York Presbyterian Hospital (NYPH). Researchers working with the Systematized Nomenclature of Medicine (SNOMED), the Unified Medical Language System (UMLS), and NYPH's Medical Entities Dictionary (MED) have created a wide variety of terminology browsers, editors and servers to facilitate creation, maintenance and use of these terminologies. Although much work has been done, no generally available tools have yet emerged. Consensus on requirement for tool functions, especially terminology servers is emerging. Tools at NYPH have been used successfully to support the integration of clinical applications and the merger of health care institutions. Significant advancement has occurred over the past fifteen years in the development of sophisticated controlled terminologies and the tools to support them. The tool set at NYPH provides a case study to demonstrate one feasible architecture.

Acting to gain information

NASA Technical Reports Server (NTRS)

Rosenchein, Stanley J.; Burns, J. Brian; Chapman, David; Kaelbling, Leslie P.; Kahn, Philip; Nishihara, H. Keith; Turk, Matthew

1993-01-01

This report is concerned with agents that act to gain information. In previous work, we developed agent models combining qualitative modeling with real-time control. That work, however, focused primarily on actions that affect physical states of the environment. The current study extends that work by explicitly considering problems of active information-gathering and by exploring specialized aspects of information-gathering in computational perception, learning, and language. In our theoretical investigations, we analyzed agents into their perceptual and action components and identified these with elements of a state-machine model of control. The mathematical properties of each was developed in isolation and interactions were then studied. We considered the complexity dimension and the uncertainty dimension and related these to intelligent-agent design issues. We also explored active information gathering in visual processing. Working within the active vision paradigm, we developed a concept of 'minimal meaningful measurements' suitable for demand-driven vision. We then developed and tested an architecture for ongoing recognition and interpretation of visual information. In the area of information gathering through learning, we explored techniques for coping with combinatorial complexity. We also explored information gathering through explicit linguistic action by considering the nature of conversational rules, coordination, and situated communication behavior.

The Nuka System of Care: improving health through ownership and relationships.

PubMed

Gottlieb, Katherine

2013-01-01

Southcentral Foundation's Nuka System of Care, based in Anchorage, Alaska, is a result of a customer-driven overhaul of what was previously a bureaucratic system centrally controlled by the Indian Health Service. Alaska Native people are in control as the "customer-owners" of this health care system. The vision and mission focus on physical, mental, emotional, and spiritual wellness and working together as a Native Community. Coupled with operational principles based on relationships, core concepts and key points, this framework has fostered an environment for creativity, innovation and continuous quality improvement. Alaska Native people have received national and international recognition for their work and have set high standards for performance excellence, community engagement, and overall impact on population health. In this article, the health care transformation led by Alaska Native people is described and the benefits and results of customer ownership and the relationship-based Nuka System of Care are discussed.

The Nuka System of Care: improving health through ownership and relationships

PubMed Central

Gottlieb, Katherine

2013-01-01

Southcentral Foundation’s Nuka System of Care, based in Anchorage, Alaska, is a result of a customer-driven overhaul of what was previously a bureaucratic system centrally controlled by the Indian Health Service. Alaska Native people are in control as the “customer-owners” of this health care system. The vision and mission focus on physical, mental, emotional, and spiritual wellness and working together as a Native Community. Coupled with operational principles based on relationships, core concepts and key points, this framework has fostered an environment for creativity, innovation and continuous quality improvement. Alaska Native people have received national and international recognition for their work and have set high standards for performance excellence, community engagement, and overall impact on population health. In this article, the health care transformation led by Alaska Native people is described and the benefits and results of customer ownership and the relationship-based Nuka System of Care are discussed. PMID:23984269

Process control of GMAW by detection of discontinuities in the molten weld pool

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

Carlson, N.M.; Kunerth, D.C.; Johnson, J.A.

1988-01-01

The use of ultrasonic sensors to detect discontinuities associated with the molten pool is one phase of a project to automate the welding process. In this work, ultrasonic sensors were used to interrogate the region around the molten/solid interface during gas metal arc welding (GMAW). The ultrasonic echoes from the interface and the molten pool provide information about the quality of the fusion zone and the molten pool. This information can be sent to a controller that can vary the welding parameters to correct the process. Previously ultrasonic shear waves were used to determine if the geometry of the molten/solidmore » interface was indicative of an acceptable weld. In this work, longitudinal waves were used to interrogate the molten weld pool for discontinuities. Unacceptable welding conditions that can result in porosity, incomplete penetration, or undercut were detected. 8 refs., 4 figs.« less

Handling Ibuprofen Increases Pain Tolerance and Decreases Perceived Pain Intensity in a Cold Pressor Test

PubMed Central

Rutchick, Abraham M.; Slepian, Michael L.

2013-01-01

Pain contributes to health care costs, missed work and school, and lower quality of life. Extant research on psychological interventions for pain has focused primarily on developing skills that individuals can apply to manage their pain. Rather than examining internal factors that influence pain tolerance (e.g., pain management skills), the current work examines factors external to an individual that can increase pain tolerance. Specifically, the current study examined the nonconscious influence of exposure to meaningful objects on the perception of pain. Participants (N = 54) completed a cold pressor test, examined either ibuprofen or a control object, then completed another cold pressor test. In the second test, participants who previously examined ibuprofen reported experiencing less intense pain and tolerated immersion longer (relative to baseline) than those who examined the control object. Theoretical and applied implications of these findings are discussed. PMID:23469170

Adding Support to the ALMA Common Software for Real-Time Operations through the Usage of a POSIX-Compliant RTOS

NASA Astrophysics Data System (ADS)

Tobar, R. J.; von Brand, H.; Araya, M. A.; Juerges, T.

2010-12-01

The ALMA Common Software (ACS) framework lacks of the real-time capabilities to control the antennas’ instrumentation — as has been probed by previous works — which has lead to non-portable workarounds to the problem. Indeed, the time service used in ACS, based in the Container/Component model, presents plenty of results that confirm this statement. This work addresses the problem of design and integrate a real-time service for ACS, providing to the framework an implementation such that the control operations over the different instruments could be done within real-time constraints. This implementation is compared with the current time service, showing the difference between the two systems when subjecting them to common scenarios. Also, the new implementation is done following the POSIX specification, ensuring interoperability and portability through different operating systems.

The Work Compatibility Improvement Framework: an integrated perspective of the human-at-work system.

PubMed

Genaidy, Ash; Salem, Sam; Karwowski, Waldemar; Paez, Omar; Tuncel, Setenay

2007-01-15

The industrial revolution demonstrated the limitations of a pure mechanistic approach towards work design. Human work is now seen as a complex entity that involves different scientific branches and blurs the line between mental and physical activities. Job design has been a traditional concern of applied psychology, which has provided insight into the interaction between the individual and the work environment. The goal of this paper is to introduce the human-at-work system as a holistic approach to organizational design. It postulates that the well-being of workers and work outcomes are issues that need to be addressed jointly, moving beyond traditional concepts of job satisfaction and work stress. The work compatibility model (WCM) is introduced as an engineering approach that seeks to integrate previous constructs of job and organizational design. The WCM seeks a balance between energy expenditure and replenishment. The implementation of the WCM in industrial settings is described within the context of the Work Compatibility Improvement Framework. A sample review of six models (motivation-hygiene theory; job characteristics theory; person-environment fit; demand-control model; and balance theory) provides the foundation for the interaction between the individual and the work environment. A review of three workload assessment methods (position analysis questionnaire, job task analysis and NASA task load index) gives an example of the foundation for the taxonomy of work environment domains. Previous models have sought to identify a balance state for the human-at-work system. They differentiated between the objective and subjective effects of the environment and the worker. An imbalance between the person and the environment has been proven to increase health risks. The WCM works with a taxonomy of 12 work domains classified in terms of the direct (acting) or indirect (experienced) effect on the worker. In terms of measurement, two quantitative methods are proposed to measure the state of the system. The first method introduced by Abdallah et al. (2004) identifies operating zones. The second method introduced by Salem et al. (2006) identifies the distribution of the work elements on the x/y coordinate plane. While previous efforts have identified some relevant elements of the systems, they failed to provide a holistic, quantitative approach combining organizational and human factors into a common framework. It is postulated that improving the well-being of workers will simultaneously improve organizational outcomes. The WCM moves beyond previous models by providing a hierarchical structure of work domains and a combination of methods to diagnose any organizational setting. The WCM is an attempt to achieve organizational excellence in human resource management, moving beyond job design to an integrated improvement strategy. A joint approach to organizational and job design will not only result in decreased prevalence of health risks, but in enhanced organizational effectiveness as well. The implementation of the WCM, that is, the Work Compatibility Improvement Framework, provides the basis for integrating different elements of the work environment into a single reliable construct. An improvement framework is essential to ensure that the measures of the WCM result in a system that is adaptive and self-regulated.

Driving behaviors and on-duty road accidents: a French case-control study.

PubMed

Fort, Emmanuel; Chiron, Mireille; Davezies, Philippe; Bergeret, Alain; Charbotel, Barbara

2013-01-01

A case-control study was carried out to identify driving behaviors associated with the risk of on-duty road accident and to compare driving behaviors according to the type of journey (on duty, commuting, and private) for on-duty road accident victims. Cases were recruited from the Rhône Road Trauma Registry between January 2004 and October 2005 and were on duty at the time of the accident. Control subjects were recruited from the electoral rolls of the case subjects' constituencies of residence. Cases' and controls' driving behavior data were collected by self-administered questionnaire. A logistic regression was performed to identify behavioral risk factors for on-duty road accidents, taking into account age, sex, place of residence, road accident risk exposure, socio-occupational category, and type of road user. A second analysis focused specifically on the case subjects, comparing their self-assessed usual behaviors according to the type of journey. Significant factors for multivariate analysis of on-duty road accidents were female gender, history of on-duty road accidents during the previous 10 years, severe time pressure at work, and driving a vehicle not belonging to the driver. On-duty road accident victims reported behavioral risk factors more frequently in relation to driving for work than driving for private reasons or commuting: nonsystematic seat belt use, cell phone use at least once daily while driving, and history of accidents with injury during the previous 10 years. This study provides knowledge on behavioral risk factors for on-duty road accidents and differences in behavior according to the type of journey for subjects who have been on-duty road accident victims. These results will be useful for the design of on-duty road risk prevention.

Biologically inspired design of feedback control systems implemented using DNA strand displacement reactions.

PubMed

Foo, Mathias; Sawlekar, Rucha; Kulkarni, Vishwesh V; Bates, Declan G

2016-08-01

The use of abstract chemical reaction networks (CRNs) as a modelling and design framework for the implementation of computing and control circuits using enzyme-free, entropy driven DNA strand displacement (DSD) reactions is starting to garner widespread attention in the area of synthetic biology. Previous work in this area has demonstrated the theoretical plausibility of using this approach to design biomolecular feedback control systems based on classical proportional-integral (PI) controllers, which may be constructed from CRNs implementing gain, summation and integrator operators. Here, we propose an alternative design approach that utilises the abstract chemical reactions involved in cellular signalling cycles to implement a biomolecular controller - termed a signalling-cycle (SC) controller. We compare the performance of the PI and SC controllers in closed-loop with a nonlinear second-order chemical process. Our results show that the SC controller outperforms the PI controller in terms of both performance and robustness, and also requires fewer abstract chemical reactions to implement, highlighting its potential usefulness in the construction of biomolecular control circuits.

Toddlers’ dysregulated fear predicts delta-beta coupling during preschool

PubMed Central

Phelps, Randi A.; Brooker, Rebecca J.; Buss, Kristin A.

2015-01-01

Dysregulated fear, or the persistence of high levels of fear in low-threat contexts, is an early risk factor for the development of anxiety symptoms. Previous work has suggested both propensities for over-control and under-control of fearfulness as risk factors for anxiety problems, each of which may be relevant to observations of dysregulated fear. Given difficulty disentangling over-control and under-control through traditional behavioral measures, we used delta-beta coupling to begin to understand the degree to which dysregulated fear may reflect propensities for over- or under-control. We found that toddlers who showed high levels of dysregulated fear evidenced greater delta-beta coupling at frontal and central electrode sites as preschoolers relative to children who were low in dysregulated fear. Importantly, these differences were not observed when comparisons were made based on fear levels in high threat contexts. Results suggest dysregulated fear may involve tendencies toward over-control at the neural level. PMID:26624221

Real-time and simultaneous control of artificial limbs based on pattern recognition algorithms.

PubMed

Ortiz-Catalan, Max; Håkansson, Bo; Brånemark, Rickard

2014-07-01

The prediction of simultaneous limb motions is a highly desirable feature for the control of artificial limbs. In this work, we investigate different classification strategies for individual and simultaneous movements based on pattern recognition of myoelectric signals. Our results suggest that any classifier can be potentially employed in the prediction of simultaneous movements if arranged in a distributed topology. On the other hand, classifiers inherently capable of simultaneous predictions, such as the multi-layer perceptron (MLP), were found to be more cost effective, as they can be successfully employed in their simplest form. In the prediction of individual movements, the one-vs-one (OVO) topology was found to improve classification accuracy across different classifiers and it was therefore used to benchmark the benefits of simultaneous control. As opposed to previous work reporting only offline accuracy, the classification performance and the resulting controllability are evaluated in real time using the motion test and target achievement control (TAC) test, respectively. We propose a simultaneous classification strategy based on MLP that outperformed a top classifier for individual movements (LDA-OVO), thus improving the state-of-the-art classification approach. Furthermore, all the presented classification strategies and data collected in this study are freely available in BioPatRec, an open source platform for the development of advanced prosthetic control strategies.

Acceleration control system for semi-active in-car crib with joint application of regular and inverted pendulum mechanisms

NASA Astrophysics Data System (ADS)

Kawashima, T.

2016-09-01

To reduce the risk of injury to an infant in an in-car crib (or in a child safety bed) collision shock during a car crash, it is necessary to maintain a constant force acting on the crib below a certain allowable value. To realize this objective, we propose a semi-active in-car crib system with the joint application of regular and inverted pendulum mechanisms. The arms of the proposed crib system support the crib like a pendulum while the pendulum system itself is supported like an inverted pendulum by the arms. In addition, the friction torque of each arm is controlled using a brake mechanism that enables the proposed in-car crib to decrease the acceleration of the crib gradually and maintain it around the target value. This system not only reduces the impulsive force but also transfers the force to the infant's back using a spin control system, i.e., the impulse force acts is made to act perpendicularly on the crib. The spin control system was developed in our previous work. This work focuses on the acceleration control system. A semi-active control law with acceleration feedback is introduced, and the effectiveness of the system is demonstrated using numerical simulation and model experiment.

Adolescent social defeat decreases spatial working memory performance in adulthood.

PubMed

Novick, Andrew M; Miiller, Leah C; Forster, Gina L; Watt, Michael J

2013-10-17

Adolescent social stress is associated with increased incidence of mental illnesses in adulthood that are characterized by deficits in cognitive focus and flexibility. Such enhanced vulnerability may be due to psychosocial stress-induced disruption of the developing mesocortical dopamine system, which plays a fundamental role in facilitating complex cognitive processes such as spatial working memory. Adolescent rats exposed to repeated social defeat as a model of social stress develop dopaminergic hypofunction in the medial prefrontal cortex as adults. To evaluate a direct link between adolescent social stress and later deficits in cognitive function, the present study tested the effects of adolescent social defeat on two separate tests of spatial working memory performance. Adult rats exposed to adolescent social defeat and their controls were trained on either the delayed win-shift task or the delayed alternating T-Maze task and then challenged with various delay periods. To evaluate potential differences in motivation for the food reward used in memory tasks, consumption and conditioned place preference for sweetened condensed milk were tested in a separate cohort of previously defeated rats and controls. Compared to controls, adult rats defeated in adolescence showed a delay-dependent deficit in spatial working memory performance, committing more errors at a 90 s and 5 min delay period on the T-maze and win-shift tasks, respectively. Observed memory deficits were likely independent of differences in reward motivation, as conditioned place preference for the palatable food used on both tasks was similar between the adolescent social defeat group and control. The results demonstrate that severe social stressors during adolescence can produce long term deficits in aspects of cognitive function. Given the dependence of spatial working memory on prefrontal dopamine, pharmacologically reversing dopaminergic deficiencies caused by adolescent social stress has the potential to treat such cognitive deficits.

Effects of working memory load, a history of conduct disorder, and sex on decision making in substance dependent individuals.

PubMed

Fridberg, Daniel J; Gerst, Kyle R; Finn, Peter R

2013-12-01

Substance dependence and antisocial psychopathology, such as a history of childhood conduct disorder (HCCD), are associated with impulsive or disadvantageous decision making and reduced working memory capacity (WMC). Reducing WMC via a working memory load increases disadvantageous decision making in healthy adults, but no previous studies have examined this effect in young adults with substance dependence and HCCD. Young adults with substance dependence (SubDep; n=158, 71 female), substance dependence and HCCD (SubDep+HCCD; n=72, 24 female), and control participants (n=152, 84 female) completed a test of decision making (the Iowa Gambling Task; IGT) with or without a concurrent working memory load intended to tax WMC. Outcomes were (i) net advantageous decisions on the IGT, and (ii) preferences for infrequent- versus frequent-punishment decks. SubDep+HCCD men made fewer advantageous decisions on the IGT than control men without a load, but there were no group differences among women in that condition. Load was associated with fewer advantageous decisions for SubDep+HCCD women and control men, but not for men or women in the other groups. Participants showed greater preference for infrequent-punishment, advantageous decks under load as well. There are gender differences in the effects of substance dependence, HCCD, and working memory load on decision making on the IGT. Decision making by control men and SubDep+HCCD women suffered the most under load. Load increases preferences for less-frequent punishments, similar to a delay discounting effect. Future research should clarify the cognitive and neural mechanisms underlying these effects. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Advanced Outage and Control Center: Strategies for Nuclear Plant Outage Work Status Capabilities

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

Gregory Weatherby

The research effort is a part of the Light Water Reactor Sustainability (LWRS) Program. LWRS is a research and development program sponsored by the Department of Energy, performed in close collaboration with industry to provide the technical foundations for licensing and managing the long-term, safe and economical operation of current nuclear power plants. The LWRS Program serves to help the US nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The Outage Control Center (OCC) Pilot Project was directed at carrying out the applied researchmore » for development and pilot of technology designed to enhance safe outage and maintenance operations, improve human performance and reliability, increase overall operational efficiency, and improve plant status control. Plant outage management is a high priority concern for the nuclear industry from cost and safety perspectives. Unfortunately, many of the underlying technologies supporting outage control are the same as those used in the 1980’s. They depend heavily upon large teams of staff, multiple work and coordination locations, and manual administrative actions that require large amounts of paper. Previous work in human reliability analysis suggests that many repetitive tasks, including paper work tasks, may have a failure rate of 1.0E-3 or higher (Gertman, 1996). With between 10,000 and 45,000 subtasks being performed during an outage (Gomes, 1996), the opportunity for human error of some consequence is a realistic concern. Although a number of factors exist that can make these errors recoverable, reducing and effectively coordinating the sheer number of tasks to be performed, particularly those that are error prone, has the potential to enhance outage efficiency and safety. Additionally, outage management requires precise coordination of work groups that do not always share similar objectives. Outage managers are concerned with schedule and cost, union workers are concerned with performing work that is commensurate with their trade, and support functions (safety, quality assurance, and radiological controls, etc.) are concerned with performing the work within the plants controls and procedures. Approaches to outage management should be designed to increase the active participation of work groups and managers in making decisions that closed the gap between competing objectives and the potential for error and process inefficiency.« less

Buck-boost converter for simultaneous semi-active vibration control and energy harvesting for electromagnetic regenerative shock absorber

NASA Astrophysics Data System (ADS)

Li, Peng; Zhang, Chongxiao; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

2014-04-01

Regenerative semi-active suspensions can capture the previously dissipated vibration energy and convert it to usable electrical energy for powering on-board electronic devices, while achieve both the better ride comfort and improved road handling performance at the same time when certain control is applied. To achieve this objective, the power electronics interface circuit connecting the energy harvester and the electrical loads, which can perform simultaneous vibration control and energy harvesting function is in need. This paper utilized a buck-boost converter for simultaneous semi-active vibration control and energy harvesting with electromagnetic regenerative shock absorber, which utilizes a rotational generator to converter the vibration energy to electricity. It has been found that when the circuit works in discontinuous current mode (DCM), the ratio between the input voltage and current is only related to the duty cycle of the switch pulse width modulation signal. Using this property, the buck-boost converter can be used to perform semi-active vibration control by controlling the load connected between the terminals of the generator in the electromagnetic shock absorber. While performing the vibration control, the circuit always draw current from the shock absorber and the suspension remain dissipative, and the shock absorber takes no additional energy to perform the vibration control. The working principle and dynamics of the circuit has been analyzed and simulations were performed to validate the concept.

Collaborative Protection and Control Schemes for Shipboard Electrical Systems

DTIC Science & Technology

2007-03-26

VSCs ) for fault current limiting and interruption. Revisions needed on the VSCs to perform these functions have been identified, and feasibility of this...disturbances very fast - less than 3-4 ms [3]. Next section summarizes the details of the agent based protection scheme that uses the VSC as the...fault currents. In our previous work [2, 3], it has been demonstrated that this new functionally for VSC can be achieved by proper selection of

Assessing the controls of the snow energy balance and water available for runoff in a rain-an-snow environment

Treesearch

Adam B. Mazurkiewicz; David G. Callery; Jeffrey J. McDonnell

2008-01-01

Rain-on-snow (ROS) melt production and its contribution to water available for runoff is poorly understood. In the Pacific Northwest (PNW) of the USA, ROS drives many runoff events with turbulent energy exchanges dominating the snow energy balance (EB). While previous experimental work in the PNW (most notably the H.J. Andrews Experimental Forest (HJA» has quantified...

Ho’ oponopono: A Radar Calibration CubeSat

DTIC Science & Technology

2011-10-13

100 photodiodes that act as sun sensors. Much of the development of the Kalman filter used to carry out these measurements is based on previous work...Deter- mination via Kalman Filtering of Magnetometer Data,” Journal of Guidance, Control and Dynam- ics, vol. 13, May-June 1990. 21. Flatley, T.W...participant in the AFOSR University Nanosatellite Program (UNP), Ho‘oponopono’s design is also con- strained to program requirements that include14

Low Control and High Demands at Work as Risk Factors for Suicide: An Australian National Population-Level Case-Control Study.

PubMed

Milner, Allison; Spittal, Matthew J; Pirkis, Jane; Chastang, Jean-François; Niedhammer, Isabelle; LaMontagne, Anthony D

2017-04-01

Previous research suggests that psychosocial job stressors may be plausible risk factors for suicide. This study assessed the relationship between psychosocial job stressors and suicide mortality across the Australian population. We developed a job exposure matrix to objectively measure job stressors across the working population. Suicide data came from a nationwide coronial register. Living controls were selected from a nationally representative cohort study. Incidence density sampling was used to ensure that controls were sampled at the time of death of each case. The period of observation for both cases and controls was 2001 to 2012. We used multilevel logistic regression to assess the odds of suicide in relation to 2 psychosocial job stressors (job control and job demands), after matching for age, sex, and year of death/survey and adjusting for socioeconomic status. Across 9,010 cases and 14,007 matched controls, our results suggest that low job control (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.26-1.44; p < .001) and high job demands (OR, 1.36; 95% CI, 1.26-1.46; p < .001) were associated with increased odds of male suicide after adjusting for socioeconomic status. High demands were associated with lower odds of female suicide (OR, 0.81; 95% CI, 0.72-0.92; p = .002). It seems that adverse experiences at work are a risk factor for male suicide while not being associated with an elevated risk among females. Future studies on job stressors and suicide are needed, both to further understand the biobehavioral mechanisms explaining the link between job stress and suicide, and to inform targeted prevention initiatives.

Salinity Trends in the Upper Colorado River Basin Upstream From the Grand Valley Salinity Control Unit, Colorado, 1986-2003

USGS Publications Warehouse

Leib, Kenneth J.; Bauch, Nancy J.

2008-01-01

In 1974, the Colorado River Basin Salinity Control Act was passed into law. This law was enacted to address concerns regarding the salinity content of the Colorado River. The law authorized various construction projects in selected areas or 'units' of the Colorado River Basin intended to reduce the salinity load in the Colorado River. One such area was the Grand Valley Salinity Control Unit in western Colorado. The U. S. Geological Survey has done extensive studies and research in the Grand Valley Salinity Control Unit that provide information to aid the U.S. Bureau of Reclamation and the Natural Resources Conservation Service in determining where salinity-control work may provide the best results, and to what extent salinity-control work was effective in reducing salinity concentrations and loads in the Colorado River. Previous studies have indicated that salinity concentrations and loads have been decreasing downstream from the Grand Valley Salinity Control Unit, and that the decreases are likely the result of salinity control work in these areas. Several of these reports; however, also document decreasing salinity loads upstream from the Grand Valley Salinity Control Unit. This finding was important because only a small amount of salinity-control work was being done in areas upstream from the Grand Valley Salinity Control Unit at the time the findings were reported (late 1990?s). As a result of those previous findings, the U.S. Bureau of Reclamation entered into a cooperative agreement with the U.S. Geological Survey to investigate salinity trends in selected areas bracketing the Grand Valley Salinity Control Unit and regions upstream from the Grand Valley Salinity Control Unit. The results of the study indicate that salinity loads were decreasing upstream from the Grand Valley Salinity Control Unit from 1986 through 2003, but the rates of decrease have slowed during the last 10 years. The average rate of decrease in salinity load upstream from the Grand Valley Salinity Control Unit was 10,700 tons/year. This accounts for approximately 27 percent of the decrease observed downstream from the Grand Valley Salinity Control Unit. Salinity loads were decreasing at the fastest rate (6,950 tons/year) in Region 4, which drains an area between the Colorado River at Cameo, Colorado (station CAMEO) and Colorado River above Glenwood Springs, Colorado (station GLEN) streamflow-gaging stations. Trends in salinity concentration and streamflow were tested at station CAMEO to determine if salinity concentration, streamflow, or both are controlling salinity loads upstream from the Grand Valley Salinity Control Unit. Trend tests of individual ion concentrations were included as potential indicators of what sources (based on mineral composition) may be controlling trends in the upper Colorado. No significant trend was detected for streamflow from 1986 to 2003 at station CAMEO; however, a significant downward trend was detected for salinity concentration. The trend slope indicates that salinity concentration is decreasing at a median rate of about 3.54 milligrams per liter per year. Five major ions (calcium, magnesium, sodium, sulfate, and chloride) were tested for trends. The results indicate that processes within source areas with rock and soil types (or other unidentified sources) bearing calcium, sodium, and sulfate had the largest effect on the downward trend in salinity load upstream from station CAMEO. Downward trends in salinity load resulting from ground-water sources and/or land-use change were thought to be possible reasons for the observed decreases in salinity loads; however, the cause or causes of the decreasing salinity loads are not fully understood. A reduction in the amount of ground-water percolation from Region 4 (resulting from work done through Federal irrigation system improvement programs as well as privately funded irrigation system improvements) has helped reduce annual salinity load from Region 4 by approxima

When is working memory important for arithmetic? The impact of strategy and age.

PubMed

Cragg, Lucy; Richardson, Sophie; Hubber, Paula J; Keeble, Sarah; Gilmore, Camilla

2017-01-01

Our ability to perform arithmetic relies heavily on working memory, the manipulation and maintenance of information in mind. Previous research has found that in adults, procedural strategies, particularly counting, rely on working memory to a greater extent than retrieval strategies. During childhood there are changes in the types of strategies employed, as well as an increase in the accuracy and efficiency of strategy execution. As such it seems likely that the role of working memory in arithmetic may also change, however children and adults have never been directly compared. This study used traditional dual-task methodology, with the addition of a control load condition, to investigate the extent to which working memory requirements for different arithmetic strategies change with age between 9-11 years, 12-14 years and young adulthood. We showed that both children and adults employ working memory when solving arithmetic problems, no matter what strategy they choose. This study highlights the importance of considering working memory in understanding the difficulties that some children and adults have with mathematics, as well as the need to include working memory in theoretical models of mathematical cognition.

Sleep problems and computer use during work and leisure: Cross-sectional study among 7800 adults.

PubMed

Andersen, Lars Louis; Garde, Anne Helene

2015-01-01

Previous studies linked heavy computer use to disturbed sleep. This study investigates the association between computer use during work and leisure and sleep problems in working adults. From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners on daytime schedule (N = 7883) replied to the Bergen insomnia scale and questions on weekly duration of computer use. Results showed that sleep problems for three or more days per week (average of six questions) were experienced by 14.9% of the respondents. Logistic regression analyses, controlled for gender, age, physical and psychosocial work factors, lifestyle, chronic disease and mental health showed that computer use during leisure for 30 or more hours per week (reference 0-10 hours per week) was associated with increased odds of sleep problems (OR 1.83 [95% CI 1.06-3.17]). Computer use during work and shorter duration of computer use during leisure were not associated with sleep problems. In conclusion, excessive computer use during leisure - but not work - is associated with sleep problems in adults working on daytime schedule.

Inhibitory Control and Working Memory in Post-Institutionalized Children

PubMed Central

Merz, Emily C.; McCall, Robert B.; Wright, Amanda J.; Luna, Beatriz

2013-01-01

Inhibitory control and working memory were examined in post-institutionalized (PI) children adopted into United States families from Russian institutions. The PI sample originated from institutions that were less severely depriving than those represented in previous studies and approximated the level of psychosocial deprivation, which is characterized by adequate physical resources but a lack of consistent and responsive caregiving. PI children (N=75; 29 male) ranged in age from 8–17 years (M=12.97; SD=3.03) and were grouped according to whether they were adopted after 14 months or before 9 months. A non-adopted comparison group (N=133; 65 male) ranged in age from 8–17 years (M=12.26; SD=2.75). PI children adopted after 14 months of age displayed poorer performance on the stop-signal and spatial span tasks relative to PI children adopted before 9 months of age after controlling for age at assessment. The two PI groups did not differ in their performance on a spatial self-ordered search task. Older-adopted PI children also showed poorer spatial span task performance compared to non-adopted children, but younger-adopted PI children did not. Task performance was significantly associated with parent-rated hyperactive-impulsive behavior in everyday contexts. These findings suggest that exposure to prolonged early institutional deprivation may be linked with inhibitory control and working memory difficulties years after adoption. PMID:23519375

The effects of autonomy-supportive and controlling teaching behaviour in biology lessons with primary and secondary experiences on students' intrinsic motivation and flow-experience

NASA Astrophysics Data System (ADS)

Hofferber, Natalia; Basten, Melanie; Großmann, Nadine; Wilde, Matthias

2016-09-01

Self-Determination Theory and Flow Theory propose that perceived autonomy fosters the positive qualities of motivation and flow-experience. Autonomy-support can help to maintain students' motivation in very interesting learning activities and may lead to an increase in the positive qualities of motivation in less interesting learning activities. This paper investigates whether autonomy-supportive or controlling teaching behaviour influence students' motivation and flow-experience in biology class. In study 1, 158 students of grade six worked on the adaptations of Harvest Mice (Micromys minutus) with living animals. The 153 sixth graders of study 2 dealt with the same content but instead worked with short films on laptops. Previous studies have shown that students perceive film sequences as less interesting than working with living animals. Students' intrinsic motivation and flow-experience were measured at the end of the first and the third lesson. In study 1, autonomy-supportive teaching behaviour led to significant differences in students' intrinsic motivation and flow-experience when compared to controlling teaching behaviour. In study 2, motivation and flow-experience were not always in line with theory. The positive effects of autonomy-supportive and the non-beneficial effects of the controlling teaching behaviour seem to be dependent on the interestingness of the teaching material.

Attitudes and concerns of Canadian animal health technologists toward postoperative pain management in dogs and cats.

PubMed

Dohoo, S E; Dohoo, I R

1998-08-01

Three hundred and twenty-two Canadian animal health technologists (AHTs) were surveyed to determine their attitudes toward postoperative pain management in dogs and cats following 6 surgical procedures, their concerns regarding the use of opioid analgesics, and their role within veterinary practices with respect to postoperative pain control. Two hundred and sixty-four (82%) returned the questionnaire. Pain perception was defined as the average of pain rankings for dogs and cats (on a scale of 1 to 10) following abdominal surgery, or the value for dogs or cats if the AHT worked with only 1 of the 2 species. Maximum concern about the risks associated with the postoperative use of morphine or oxymorphone was defined as the highest rating assigned to any of the 6 risks evaluated in either dogs or cats. Animal health technologists reported significantly higher pain perception scores than did veterinarians who completed a similar survey 2 years previously. Higher pain perception scores were associated with decreased satisfaction with the adequacy of analgesic therapy in their practice, higher pain control goals, and attendance at continuing education within the previous 12 months. The majority of AHTs (55%) agreed that one or more risks associated with the use of morphine or oxymorphone outweighed the benefits. The 3 issues that were perceived to pose the greatest risk were respiratory depression, bradycardia, and sedation and excitement, for dogs and cats, respectively. Most AHTs (68%) considered their knowledge related to the recognition and control of pain to be adequate, compared with 24% of veterinarians who responded to a similar previous survey. As for veterinarians, experience gained while in practice was ranked as the most important source of knowledge, while the technical program attended was ranked as least important. Over 88% of the AHTs provided nursing care during the postoperative period, monitored animals for side effects of postoperative analgesic therapy, informed veterinarians when animals were in pain, recommended analgesic therapy when they believed it was warranted, reported that animals received analgesics when they believed it was warranted, administered analgesics under the instruction of a veterinarian, and believed they were part of a team working to provide adequate postoperative pain control.

Microstructural Corpus Callosum Anomalies in Children With Prenatal Alcohol Exposure: An Extension of Previous Diffusion Tensor Imaging Findings

PubMed Central

Wozniak, Jeffrey R.; Muetzel, Ryan L.; Mueller, Bryon A.; McGee, Christie L.; Freerks, Melesa A.; Ward, Erin E.; Nelson, Miranda L.; Chang, Pi-Nian; Lim, Kelvin O.

2010-01-01

Background Several studies have now shown corpus callosum abnormalities using diffusion tensor imaging (DTI) in children with fetal alcohol spectrum disorders (FASD) in comparison with nonexposed controls. The data suggest that posterior regions of the callosum may be disproportionately affected. The current study builds on previous efforts, including our own work, and moves beyond midline corpus callosum to probe major inter-hemispheric white matter pathways with an improved DTI tractographic method. This study also expands on our prior work by evaluating a larger sample and by incorporating children with a broader range of clinical effects including full-criteria fetal alcohol syndrome (FAS). Methods Participants included 33 children with FASD (8 FAS, 23 partial FAS, 2 static encephalopathy) and 19 nonexposed controls between the ages of 10 and 17 years. Participants underwent DTI scans and intelligence testing. Groups (FASD vs. controls) were compared on fractional anisotropy (FA) and mean diffusivity (MD) in 6 white matter tracts projected through the corpus callosum. Exploratory analyses were also conducted examining the relationships between DTI measures in the corpus callosum and measures of intellectual functioning and facial dysmorphology. Results In comparison with the control group, the FASD group had significantly lower FA in 3 posterior tracts of the corpus callosum: the posterior mid-body, the isthmus, and the splenium. A trend-level finding also suggested lower FA in the genu. Measures of white matter integrity and cognition were correlated and suggest some regional specificity, in that only posterior regions of the corpus callosum were associated with visual-perceptual skills. Correlations between measures of facial dysmorphology and posterior regions of the corpus callosum were nonsignificant. Conclusions Consistent with previous DTI studies, these results suggest that microstructural posterior corpus callosum abnormalities are present in children with prenatal alcohol exposure and cognitive impairment. These abnormalities are clinically relevant because they are associated with cognitive deficits and appear to provide evidence of abnormalities associated with prenatal alcohol exposure independent of dysmorphic features. As such, they may yield important diagnostic and prognostic information not provided by the traditional facial characteristics. PMID:19645729

Exposure to welding fumes is associated with hypomethylation of the F2RL3 gene: a cardiovascular disease marker.

PubMed

Hossain, Mohammad B; Li, Huiqi; Hedmer, Maria; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

2015-12-01

Welders are at risk for cardiovascular disease. Recent studies linked tobacco smoke exposure to hypomethylation of the F2RL3 (coagulation factor II (thrombin) receptor-like 3) gene, a marker for cardiovascular disease prognosis and mortality. However, whether welding fumes cause hypomethylation of F2RL3 remains unknown. We investigated 101 welders (median span of working as a welder: 7 years) and 127 unexposed controls (non-welders with no obvious exposure to respirable dust at work), age range 23-60 years, all currently non-smoking, in Sweden. The participants were interviewed about their work history, lifestyle factors and diseases. Personal sampling of respirable dust was performed for the welders. DNA methylation of F2RL3 in blood was assessed by pyrosequencing of four CpG sites, CpG_2 (corresponds to cg03636183) to CpG_5, in F2RL3. Multivariable linear regression analysis was used to assess the association between exposure to welding fumes and F2RL3 methylation. Welders had 2.6% lower methylation of CpG_5 than controls (p<0.001). Higher concentrations of measured respirable dust among the welders were associated with hypomethylation of CpG_2, CpG_4 and CpG_5 (β=-0.49 to -1.4, p<0.012); p<0.029 adjusted for age, previous smoking, passive smoking, education, current residence and respirator use. Increasing the number of years working as a welder was associated with hypomethylation of CpG_4 (linear regression analysis, β=-0.11, p=0.039, adjusted for previous smoking). Previous tobacco smokers had 1.5-4.7% (p<0.014) lower methylation of 3 of the 4 CpG sites in F2RL3 (CpG_2, CpG_4 and CpG_5) compared to never-smokers. A non-significant lower risk of cardiovascular disease with more methylation was observed for all CpG sites. Welding fumes exposure and previous smoking were associated with F2RL3 hypomethylation. This finding links low-to-moderate exposure to welding fumes to adverse effects on the cardiovascular system, and suggests a potential mechanistic pathway for this link, via epigenetic effects on F2RL3 expression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation

PubMed Central

Segal, Ava D.; Zelik, Karl E.; Klute, Glenn K.; Morgenroth, David C.; Hahn, Michael E.; Orendurff, Michael S.; Adamczyk, Peter G.; Collins, Steven H.; Kuo, Arthur D.; Czerniecki, Joseph M.

2015-01-01

The lack of functional ankle musculature in lower limb amputees contributes to the reduced prosthetic ankle push-off, compensations at other joints and more energetically costly gait commonly observed in comparison to non-amputees. A variety of energy storing and return prosthetic feet have been developed to address these issues but have not been shown to sufficiently improve amputee biomechanics and energetic cost, perhaps because the timing and magnitude of energy return is not controlled. The goal of this study was to examine how a prototype microprocessor-controlled prosthetic foot designed to store some of the energy during loading and return it during push-off affects amputee gait. Unilateral transtibial amputees wore the Controlled Energy Storage and Return prosthetic foot (CESR), a conventional foot (CONV), and their previously prescribed foot (PRES) in random order. Three-dimensional gait analysis and net oxygen consumption were collected as participants walked at constant speed. The CESR foot demonstrated increased energy storage during early stance, increased prosthetic foot peak push-off power and work, increased prosthetic limb center of mass (COM) push-off work and decreased intact limb COM collision work compared to CONV and PRES. The biological contribution of the positive COM work for CESR was reduced compared to CONV and PRES. However, the net metabolic cost for CESR did not change compared to CONV and increased compared to PRES, which may partially reflect the greater weight, lack of individualized size and stiffness and relatively less familiarity for CESR and CONV. Controlled energy storage and return enhanced prosthetic push-off, but requires further design modifications to improve amputee walking economy. PMID:22100728

Application of Time-Delay Absorber to Suppress Vibration of a Dynamical System to Tuned Excitation.

PubMed

El-Ganaini, W A A; El-Gohary, H A

2014-08-01

In this work, we present a comprehensive investigation of the time delay absorber effects on the control of a dynamical system represented by a cantilever beam subjected to tuned excitation forces. Cantilever beam is one of the most widely used system in too many engineering applications, such as mechanical and civil engineering. The main aim of this work is to control the vibration of the beam at simultaneous internal and combined resonance condition, as it is the worst resonance case. Control is conducted via time delay absorber to suppress chaotic vibrations. Time delays often appear in many control systems in the state, in the control input, or in the measurements. Time delay commonly exists in various engineering, biological, and economical systems because of the finite speed of the information processing. It is a source of performance degradation and instability. Multiple time scale perturbation method is applied to obtain a first order approximation for the nonlinear differential equations describing the system behavior. The different resonance cases are reported and studied numerically. The stability of the steady-state solution at the selected worst resonance case is investigated applying Runge-Kutta fourth order method and frequency response equations via Matlab 7.0 and Maple11. Time delay absorber is effective, but within a specified range of time delay. It is the critical factor in selecting such absorber. Time delay absorber is better than the ordinary one as from the effectiveness point of view. The effects of the different absorber parameters on the system behavior and stability are studied numerically. A comparison with the available published work showed a close agreement with some previously published work.

The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation.

PubMed

Segal, Ava D; Zelik, Karl E; Klute, Glenn K; Morgenroth, David C; Hahn, Michael E; Orendurff, Michael S; Adamczyk, Peter G; Collins, Steven H; Kuo, Arthur D; Czerniecki, Joseph M

2012-08-01

The lack of functional ankle musculature in lower limb amputees contributes to the reduced prosthetic ankle push-off, compensations at other joints and more energetically costly gait commonly observed in comparison to non-amputees. A variety of energy storing and return prosthetic feet have been developed to address these issues but have not been shown to sufficiently improve amputee biomechanics and energetic cost, perhaps because the timing and magnitude of energy return is not controlled. The goal of this study was to examine how a prototype microprocessor-controlled prosthetic foot designed to store some of the energy during loading and return it during push-off affects amputee gait. Unilateral transtibial amputees wore the Controlled Energy Storage and Return prosthetic foot (CESR), a conventional foot (CONV), and their previously prescribed foot (PRES) in random order. Three-dimensional gait analysis and net oxygen consumption were collected as participants walked at constant speed. The CESR foot demonstrated increased energy storage during early stance, increased prosthetic foot peak push-off power and work, increased prosthetic limb center of mass (COM) push-off work and decreased intact limb COM collision work compared to CONV and PRES. The biological contribution of the positive COM work for CESR was reduced compared to CONV and PRES. However, the net metabolic cost for CESR did not change compared to CONV and increased compared to PRES, which may partially reflect the greater weight, lack of individualized size and stiffness and relatively less familiarity for CESR and CONV. Controlled energy storage and return enhanced prosthetic push-off, but requires further design modifications to improve amputee walking economy. Published by Elsevier B.V.

The effects of cognitive load on attention control in subclinical anxiety and Generalized Anxiety Disorder

PubMed Central

Najmi, Sadia; Amir, Nader; Frosio, Kristen E.; Ayers, Catherine

2014-01-01

Poor regulation of emotions may involve impaired attention control. In the current paper, we report the results of two studies examining the interaction of anxiety, attention control, and cognitive load. In Study I, using a performance-based task to assess attention control, we examined whether anxiety is associated with impaired attention control, and whether these effects are influenced by working memory load. In Study II we examined these effects in patients with a diagnosis of Generalized Anxiety Disorder (GAD) compared to non-anxious control (NAC) participants. Results of Study I showed that high anxiety was associated with increased attention control, that is decreased interference from distractors, but only under high cognitive load. These results were replicated in Study II such that individuals with GAD showed increased attention control relative to NACs, but only under high cognitive load. These results help clarify previous predictions regarding the effect of anxiety on attention control. PMID:25355423

Synchronization of coupled stochastic complex-valued dynamical networks with time-varying delays via aperiodically intermittent adaptive control

NASA Astrophysics Data System (ADS)

Wang, Pengfei; Jin, Wei; Su, Huan

2018-04-01

This paper deals with the synchronization problem of a class of coupled stochastic complex-valued drive-response networks with time-varying delays via aperiodically intermittent adaptive control. Different from the previous works, the intermittent control is aperiodic and adaptive, and the restrictions on the control width and time delay are removed, which lead to a larger application scope for this control strategy. Then, based on the Lyapunov method and Kirchhoff's Matrix Tree Theorem as well as differential inequality techniques, several novel synchronization conditions are derived for the considered model. Specially, impulsive control is also considered, which can be seen as a special case of the aperiodically intermittent control when the control width tends to zero. And the corresponding synchronization criteria are given as well. As an application of the theoretical results, a class of stochastic complex-valued coupled oscillators with time-varying delays is studied, and the numerical simulations are also given to demonstrate the effectiveness of the control strategies.

Industrial relations reform and the occupational transition of Australian workers: a critical discourse analysis.

PubMed

Lo Bartolo, Luciano; Sheahan, Marie

2009-01-01

The 2005 WorkChoices legislation delivered a significant diminution of Australian workers' rights in the form of choice and control over numerous aspects of working life. WorkChoices extended previous neoliberal reforms and consolidated the negative impacts of those reforms on marginalized groups of workers, especially those in precarious employment. This paper reports on the findings of an occupational science-based, critical discourse analysis of a government newspaper advertisement that promotes the reforms. The construction of a WorkChoices discourse, one that was based on and sought to extend neoliberal hegemony, is identified by exploring the ways that particular ideas are presented as natural and mutually beneficial and, in response, the development of a counter-hegemonic argument, based on occupational justice theory, is discussed. The broader application of critical social research is also recommended in extending the occupational justice paradigm.

A Phenomenological Study of the Work Environment in Long-Term Care Facilities for the Older Adults.

PubMed

Choi, Sandy Pin Pin; Yeung, Cheryl Chi Yan; Lee, Joseph Kok Long

2018-05-01

Attempts to meet the increasing demand for long-term care (LTC) services have been hindered by acute staff shortages and high turnover. Distinct from previous studies, a descriptive phenomenological approach with van Kaam's controlled explication method was adopted in this study, to delineate how attributes of the LTC work environment shape the workforce crisis. Individual interviews were conducted with 40 LTC workers from 10 facilities in Hong Kong. The results suggest that the work environment in LTC facilities is not only characterized by organization- and job-related attributes that influence staff outcomes but also is a socially constructed concept with derogatory connotations that can influence staff recruitment and retention. Concerted efforts from facility administrators and policy makers are needed to improve the quality of the work environment. Future initiatives should focus on developing a vision and strategic plan to facilitate the rise of the LTC sector as a profession.

Robust stability bounds for multi-delay networked control systems

NASA Astrophysics Data System (ADS)

Seitz, Timothy; Yedavalli, Rama K.; Behbahani, Alireza

2018-04-01

In this paper, the robust stability of a perturbed linear continuous-time system is examined when controlled using a sampled-data networked control system (NCS) framework. Three new robust stability bounds on the time-invariant perturbations to the original continuous-time plant matrix are presented guaranteeing stability for the corresponding discrete closed-loop augmented delay-free system (ADFS) with multiple time-varying sensor and actuator delays. The bounds are differentiated from previous work by accounting for the sampled-data nature of the NCS and for separate communication delays for each sensor and actuator, not a single delay. Therefore, this paper expands the knowledge base in multiple inputs multiple outputs (MIMO) sampled-data time delay systems. Bounds are presented for unstructured, semi-structured, and structured perturbations.

Does parental consent for birth control affect underage pregnancy rates? The case of Texas.

PubMed

Girma, Sourafel; Paton, David

2013-12-01

Previous work based on conjectural responses of minors predicted that the 2003 Texas requirement for parental consent for state-funded birth control to minors would lead to a large increase in underage pregnancies. We use state- and county-level data to test this prediction. The latter allow us to compare the impact of parental consent in counties with and without state-funded family planning clinics. We control for characteristics systematically correlated with the presence of state-funded clinics by combining difference-in-difference estimation with propensity score-weighted regressions. The evidence suggests that the parental consent mandate led to a large decrease in attendance at family planning clinics among teens but did not lead to an increase in underage pregnancies.

Patterned wafer geometry grouping for improved overlay control

NASA Astrophysics Data System (ADS)

Lee, Honggoo; Han, Sangjun; Woo, Jaeson; Park, Junbeom; Song, Changrock; Anis, Fatima; Vukkadala, Pradeep; Jeon, Sanghuck; Choi, DongSub; Huang, Kevin; Heo, Hoyoung; Smith, Mark D.; Robinson, John C.

2017-03-01

Process-induced overlay errors from outside the litho cell have become a significant contributor to the overlay error budget including non-uniform wafer stress. Previous studies have shown the correlation between process-induced stress and overlay and the opportunity for improvement in process control, including the use of patterned wafer geometry (PWG) metrology to reduce stress-induced overlay signatures. Key challenges of volume semiconductor manufacturing are how to improve not only the magnitude of these signatures, but also the wafer to wafer variability. This work involves a novel technique of using PWG metrology to provide improved litho-control by wafer-level grouping based on incoming process induced overlay, relevant for both 3D NAND and DRAM. Examples shown in this study are from 19 nm DRAM manufacturing.

An experimental study of a turbulent boundary layer in the trailing edge region of a circulation-control airfoil

NASA Technical Reports Server (NTRS)

Heinemann, K.; Brown, Jeff

1992-01-01

This report discusses progress made on NASA Cooperative Agreement NCC2-545, 'An Experimental Study of a Turbulent Boundary Layer in the Trailing-Edge Region of a Circulation-Control Airfoil' during the period 9/1/91 through 9/30/92. The study features 2-component laser Doppler velocimeter (LDV) measurements in the trailing edge and wake regions of a generic 2-dimensional circulation-control model. The final experimental phase of the study will be carried out in the Ames High Reynolds Number Channel 2 (HRC2) transonic blow-down-facility. During the 13-month period covered by this report, work continued on the development of the near-wall laser Doppler velocimeter (LDV) described in previous reports.

Admittance Survey of Type 1 Coronae on Venus: Implications for Elastic Thickness

NASA Technical Reports Server (NTRS)

Hoogenboom, T.; Smrekar, S. E.; Anderson, F. S.; Houseman, G.

2003-01-01

Coronae are volcano-tectonic features on Venus which range from 60km to 2600km and are defined by their nearly circular patterns of fractures. Type 1 (regular) coronae are classified as having >50% complete fracture annuli. Previous work has examined the factors controlling the morphology, size, and fracture pattern of coronae, using lithospheric properties, loading signature and geologic characteristics. However, these studies have been limited to Type 2 (topographic) coronae (e.g. coronaes with <50% fracture annuli), and the factors controlling the formation of Type 1 coronae remain poorly understood. In this study, we apply the methodology of to survey the admittance signature for Type 1 coronae to determine the controlling parameters which govern Type 1 coronae formation.

Which daily experiences can foster well-being at work? A diary study on the interplay between flow experiences, affective commitment, and self-control demands.

PubMed

Rivkin, Wladislaw; Diestel, Stefan; Schmidt, Klaus-Helmut

2018-01-01

Previous research has provided strong evidence for affective commitment as a direct predictor of employees' psychological well-being and as a resource that buffers the adverse effects of self-control demands as a stressor. However, the mechanisms that underlie the beneficial effects of affective commitment have not been examined yet. Drawing on the self-determination theory, we propose day-specific flow experiences as the mechanism that underlies the beneficial effects of affective commitment, because flow experiences as peaks of intrinsic motivation constitute manifestations of autonomous regulation. In a diary study covering 10 working days with N = 90 employees, we examine day-specific flow experiences as a mediator of the beneficial effects of interindividual affective commitment and a buffering moderator of the adverse day-specific effects of self-control demands on indicators of well-being (ego depletion, need for recovery, work engagement, and subjective vitality). Our results provide strong support for our predictions that day-specific flow experiences a) mediate the beneficial effects of affective commitment on employees' day-specific well-being and b) moderate (buffer) the adverse day-specific effects of self-control demands on well-being. That is, on days with high levels of flow experiences, employees were better able to cope with self-control demands whereas self-control demands translated into impaired well-being when employees experienced lower levels of day-specific flow experiences. We then discuss our findings and suggest practical implications. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Lung cancer risk among bricklayers in a pooled analysis of case–control studies

PubMed Central

Consonni, Dario; Matteis, Sara De; Pesatori, Angela C; Bertazzi, Pier Alberto; Olsson, Ann C; Kromhout, Hans; Peters, Susan; Vermeulen, Roel CH; Pesch, Beate; Brüning, Thomas; Kendzia, Benjamin; Behrens, Thomas; Stücker, Isabelle; Guida, Florence; Wichmann, Heinz-Erich; Brüske, Irene; Landi, Maria Teresa; Caporaso, Neil E; Gustavsson, Per; Plato, Nils; Tse, Lap Ah; Yu, Ignatius Tak-sun; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Merletti, Franco; Richiardi, Lorenzo; Simonato, Lorenzo; Forastiere, Francesco; Siemiatycki, Jack; Parent, Marie-Élise; Tardón, Adonina; Boffetta, Paolo; Zaridze, David; Chen, Ying; Field, John K; 't Mannetje, Andrea; Pearce, Neil; McLaughlin, John; Demers, Paul; Lissowska, Jolanta; Szeszenia-Dabrowska, Neonila; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Rudnai, Peter; Fabiánová, Eleonóra; Stanescu Dumitru, Rodica; Bueno-de-Mesquita, H B(as); Schüz, Joachim; Straif, Kurt

2015-01-01

Bricklayers may be exposed to several lung carcinogens, including crystalline silica and asbestos. Previous studies that analyzed lung cancer risk among these workers had several study design limitations. We examined lung cancer risk among bricklayers within SYNERGY, a large international pooled analysis of case–control studies on lung cancer and the joint effects of occupational carcinogens. For men ever employed as bricklayers we estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for study center, age, lifetime smoking history and employment in occupations with exposures to known or suspected lung carcinogens. Among 15,608 cases and 18,531 controls, there were 695 cases and 469 controls who had ever worked as bricklayers (OR: 1.47; 95% CI: 1.28–1.68). In studies using population controls the OR was 1.55 (95% CI: 1.32–1.81, 540/349 cases/controls), while it was 1.24 (95% CI: 0.93–1.64, 155/120 cases/controls) in hospital-based studies. There was a clear positive trend with length of employment (p < 0.001). The relative risk was higher for squamous (OR: 1.68, 95% CI: 1.42–1.98, 309 cases) and small cell carcinomas (OR: 1.78, 95% CI: 1.44–2.20, 140 cases), than for adenocarcinoma (OR: 1.17, 95% CI: 0.95–1.43, 150 cases) (p-homogeneity: 0.0007). ORs were still elevated after additional adjustment for education and in analyses using blue collar workers as referents. This study provided robust evidence of increased lung cancer risk in bricklayers. Although non-causal explanations cannot be completely ruled out, the association is plausible in view of the potential for exposure to several carcinogens, notably crystalline silica and to a lesser extent asbestos. What's new? In their work, bricklayers can be exposed to various airborne carcinogens, including crystalline silica and asbestos. Previous studies of cancer risk have not accounted for full employment history or smoking status, and failed to establish a firm relationship between bricklaying and lung cancer. In this study, the authors used data from the largest collection of case-control studies on lung cancer with complete occupational and smoking history existing today, the SYNERGY project. They found clear evidence that lung cancer risk increases in proportion to the length of time spent working as a bricklayer, paving the way for better protection and compensation for those in this occupation. PMID:24861979

Functional Connectivity of Cognitive Brain Networks in Schizophrenia during a Working Memory Task

PubMed Central

Godwin, Douglass; Ji, Andrew; Kandala, Sridhar; Mamah, Daniel

2017-01-01

Task-based connectivity studies facilitate the understanding of how the brain functions during cognition, which is commonly impaired in schizophrenia (SZ). Our aim was to investigate functional connectivity during a working memory task in SZ. We hypothesized that the task-negative (default mode) network and the cognitive control (frontoparietal) network would show dysconnectivity. Twenty-five SZ patient and 31 healthy control scans were collected using the customized 3T Siemens Skyra MRI scanner, previously used to collect data for the Human Connectome Project. Blood oxygen level dependent signal during the 0-back and 2-back conditions were extracted within a network-based parcelation scheme. Average functional connectivity was assessed within five brain networks: frontoparietal (FPN), default mode (DMN), cingulo-opercular (CON), dorsal attention (DAN), and ventral attention network; as well as between the DMN or FPN and other networks. For within-FPN connectivity, there was a significant interaction between n-back condition and group (p = 0.015), with decreased connectivity at 0-back in SZ subjects compared to controls. FPN-to-DMN connectivity also showed a significant condition × group effect (p = 0.003), with decreased connectivity at 0-back in SZ. Across groups, connectivity within the CON and DAN were increased during the 2-back condition, while DMN connectivity with either CON or DAN were decreased during the 2-back condition. Our findings support the role of the FPN, CON, and DAN in working memory and indicate that the pattern of FPN functional connectivity differs between SZ patients and control subjects during the course of a working memory task. PMID:29312020

Functional Connectivity of Cognitive Brain Networks in Schizophrenia during a Working Memory Task.

PubMed

Godwin, Douglass; Ji, Andrew; Kandala, Sridhar; Mamah, Daniel

2017-01-01

Task-based connectivity studies facilitate the understanding of how the brain functions during cognition, which is commonly impaired in schizophrenia (SZ). Our aim was to investigate functional connectivity during a working memory task in SZ. We hypothesized that the task-negative (default mode) network and the cognitive control (frontoparietal) network would show dysconnectivity. Twenty-five SZ patient and 31 healthy control scans were collected using the customized 3T Siemens Skyra MRI scanner, previously used to collect data for the Human Connectome Project. Blood oxygen level dependent signal during the 0-back and 2-back conditions were extracted within a network-based parcelation scheme. Average functional connectivity was assessed within five brain networks: frontoparietal (FPN), default mode (DMN), cingulo-opercular (CON), dorsal attention (DAN), and ventral attention network; as well as between the DMN or FPN and other networks. For within-FPN connectivity, there was a significant interaction between n -back condition and group ( p  = 0.015), with decreased connectivity at 0-back in SZ subjects compared to controls. FPN-to-DMN connectivity also showed a significant condition × group effect ( p  = 0.003), with decreased connectivity at 0-back in SZ. Across groups, connectivity within the CON and DAN were increased during the 2-back condition, while DMN connectivity with either CON or DAN were decreased during the 2-back condition. Our findings support the role of the FPN, CON, and DAN in working memory and indicate that the pattern of FPN functional connectivity differs between SZ patients and control subjects during the course of a working memory task.

Disruptions of working memory and inhibition mediate the association between exposure to institutionalization and symptoms of attention deficit hyperactivity disorder.

PubMed

Tibu, F; Sheridan, M A; McLaughlin, K A; Nelson, C A; Fox, N A; Zeanah, C H

2016-02-01

Young children raised in institutions are exposed to extreme psychosocial deprivation that is associated with elevated risk for psychopathology and other adverse developmental outcomes. The prevalence of attention deficit hyperactivity disorder (ADHD) is particularly high in previously institutionalized children, yet the mechanisms underlying this association are poorly understood. We investigated whether deficits in executive functioning (EF) explain the link between institutionalization and ADHD. A sample of 136 children (aged 6-30 months) was recruited from institutions in Bucharest, Romania, and 72 never institutionalized community children matched for age and gender were recruited through general practitioners' offices. At 8 years of age, children's performance on a number of EF components (working memory, response inhibition and planning) was evaluated. Teachers completed the Health and Behavior Questionnaire, which assesses two core features of ADHD, inattention and impulsivity. Children with history of institutionalization had higher inattention and impulsivity than community controls, and exhibited worse performance on working memory, response inhibition and planning tasks. Lower performances on working memory and response inhibition, but not planning, partially mediated the association between early institutionalization and inattention and impulsivity symptom scales at age 8 years. Institutionalization was associated with decreased EF performance and increased ADHD symptoms. Deficits in working memory and response inhibition were specific mechanisms leading to ADHD in previously institutionalized children. These findings suggest that interventions that foster the development of EF might reduce risk for psychiatric problems in children exposed to early deprivation.

Ovonic switching in tin selenide thin films. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Baxter, C. R.

1974-01-01

Amorphous tin selenide thin films which possess Ovonic switching properties were fabricated using vacuum deposition techniques. Results obtained indicate that memory type Ovonic switching does occur in these films the energy density required for switching from a high impedance to a low impedance state is dependent on the spacing between the electrodes of the device. The switching is also function of the magnitude of the applied voltage pulse. A completely automated computer controlled testing procedure was developed which allows precise control over the shape of the applied voltage switching pulse. A survey of previous experimental and theoretical work in the area of Ovonic switching is also presented.

The control of a manipulator by a computer model of the cerebellum.

NASA Technical Reports Server (NTRS)

Albus, J. S.

1973-01-01

Extension of previous work by Albus (1971, 1972) on the theory of cerebellar function to an application of a computer model of the cerebellum to manipulator control. Following a discussion of the cerebellar function and of a perceptron analogy of the cerebellum, particularly in regard to learning, an electromechanical model of the cerebellum is considered in the form of an IBM 1800 computer connected to a Rancho Los Amigos arm with seven degrees of freedom. It is shown that the computer memory makes it possible to train the arm on some representative sample of the universe of possible states and to achieve satisfactory performance.

A neuro approach to solve fuzzy Riccati differential equations

NASA Astrophysics Data System (ADS)

Shahrir, Mohammad Shazri; Kumaresan, N.; Kamali, M. Z. M.; Ratnavelu, Kurunathan

2015-10-01

There are many applications of optimal control theory especially in the area of control systems in engineering. In this paper, fuzzy quadratic Riccati differential equation is estimated using neural networks (NN). Previous works have shown reliable results using Runge-Kutta 4th order (RK4). The solution can be achieved by solving the 1st Order Non-linear Differential Equation (ODE) that is found commonly in Riccati differential equation. Research has shown improved results relatively to the RK4 method. It can be said that NN approach shows promising results with the advantage of continuous estimation and improved accuracy that can be produced over RK4.

Biofeedback therapy for migraine headaches.

PubMed

Turin, A; Johnson, W G

1976-04-01

We studied the biofeedback treatment of migraine headaches, attempting to control for some of the methodological limitations of previous work. Seven individuals suffering from migraine headache were trained in the usual finger warming procedure with the omission of autogenic phrases. Additionally, to control for placebo-expectance effects, three of these subjects received training in finger cooling prior to warming. With training in finger warming, headache activity was substantially reduced. In contrast, headache activity either remained at base line levels or increased during training in cooling despite positive therapeutic expectations. The results of this study indicate that finger temperature warming, without autogenic training, is effective in reducing migraine activity, independent of suggestion effects.

A neuro approach to solve fuzzy Riccati differential equations

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

Shahrir, Mohammad Shazri, E-mail: mshazri@gmail.com; Telekom Malaysia, R&D TM Innovation Centre, LingkaranTeknokrat Timur, 63000 Cyberjaya, Selangor; Kumaresan, N., E-mail: drnk2008@gmail.com

There are many applications of optimal control theory especially in the area of control systems in engineering. In this paper, fuzzy quadratic Riccati differential equation is estimated using neural networks (NN). Previous works have shown reliable results using Runge-Kutta 4th order (RK4). The solution can be achieved by solving the 1st Order Non-linear Differential Equation (ODE) that is found commonly in Riccati differential equation. Research has shown improved results relatively to the RK4 method. It can be said that NN approach shows promising results with the advantage of continuous estimation and improved accuracy that can be produced over RK4.

Estradiol concentrations and working memory performance in women of reproductive age.

PubMed

Hampson, Elizabeth; Morley, Erin E

2013-12-01

Estrogen has been proposed to exert a regulatory influence on the working memory system via actions in the female prefrontal cortex. Tests of this hypothesis have been limited almost exclusively to postmenopausal women and pharmacological interventions. We explored whether estradiol discernibly influences working memory within the natural range of variation in concentrations characteristic of the menstrual cycle. The performance of healthy women (n=39) not using hormonal contraceptives, and a control group of age- and education-matched men (n=31), was compared on a spatial working memory task. Cognitive testing was done blind to ovarian status. Women were retrospectively classified into low- or high-estradiol groups based on the results of radioimmunoassays of saliva collected immediately before and after the cognitive testing. Women with higher levels of circulating estradiol made significantly fewer errors on the working memory task than women tested under low estradiol. Pearson's correlations showed that the level of salivary estradiol but not progesterone was correlated inversely with the number of working memory errors produced. Women tested at high levels of circulating estradiol tended to be more accurate than men. Superior performance by the high estradiol group was seen on the working memory task but not on two control tasks, indicating selectivity of the effects. Consistent with previous studies of postmenopausal women, higher levels of circulating estradiol were associated with better working memory performance. These results add further support to the hypothesis that the working memory system is modulated by estradiol in women, and show that the effects can be observed under non-pharmacological conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

fMRI response to spatial working memory in adolescents with comorbid marijuana and alcohol use disorders☆

PubMed Central

Schweinsburg, Alecia D.; Schweinsburg, Brian C.; Cheung, Erick H.; Brown, Gregory G.; Brown, Sandra A.; Tapert, Susan F.

2008-01-01

Alcohol and marijuana use are prevalent in adolescence, yet the neural impact of concomitant use remains unclear. We previously demonstrated functional magnetic resonance imaging (fMRI) response to spatial working memory (SWM) among teens with alcohol use disorders (AUD) compared to controls, and predicted that adolescents with marijuana and alcohol use disorders would show additional abnormalities. Participants were three groups of 15−17-year-olds: 19 non-abusing controls, 15 AUD teens with limited exposure to drugs, and 15 teens with comorbid marijuana and alcohol use disorders (MAUD) and minimal other drug experience. After >2 days’ abstinence, participants performed a SWM task during fMRI acquisition. fMRI brain response patterns differed between groups, despite similar performance on the task. MAUD youths showed less activation in inferior frontal and temporal regions than controls, and more response in other prefrontal regions. Compared to AUD teens, MAUD youths also showed less inferior frontal and temporal activation, but more medial frontal response. Overall, MAUD youths showed different brain response abnormalities than teens with AUD alone, despite relatively short histories of substance involvement. This pattern could suggest compensation for marijuana-related attention and working memory deficits. However, relatively recent use and premorbid features may influence results, and should be examined in future studies. PMID:16002029

Ten-dimensional anthropomorphic arm control in a human brain-machine interface: difficulties, solutions, and limitations

NASA Astrophysics Data System (ADS)

Wodlinger, B.; Downey, J. E.; Tyler-Kabara, E. C.; Schwartz, A. B.; Boninger, M. L.; Collinger, J. L.

2015-02-01

Objective. In a previous study we demonstrated continuous translation, orientation and one-dimensional grasping control of a prosthetic limb (seven degrees of freedom) by a human subject with tetraplegia using a brain-machine interface (BMI). The current study, in the same subject, immediately followed the previous work and expanded the scope of the control signal by also extracting hand-shape commands from the two 96-channel intracortical electrode arrays implanted in the subject’s left motor cortex. Approach. Four new control signals, dictating prosthetic hand shape, replaced the one-dimensional grasping in the previous study, allowing the subject to control the prosthetic limb with ten degrees of freedom (three-dimensional (3D) translation, 3D orientation, four-dimensional hand shaping) simultaneously. Main results. Robust neural tuning to hand shaping was found, leading to ten-dimensional (10D) performance well above chance levels in all tests. Neural unit preferred directions were broadly distributed through the 10D space, with the majority of units significantly tuned to all ten dimensions, instead of being restricted to isolated domains (e.g. translation, orientation or hand shape). The addition of hand shaping emphasized object-interaction behavior. A fundamental component of BMIs is the calibration used to associate neural activity to intended movement. We found that the presence of an object during calibration enhanced successful shaping of the prosthetic hand as it closed around the object during grasping. Significance. Our results show that individual motor cortical neurons encode many parameters of movement, that object interaction is an important factor when extracting these signals, and that high-dimensional operation of prosthetic devices can be achieved with simple decoding algorithms. ClinicalTrials.gov Identifier: NCT01364480.

A multi-site randomised controlled trial of evidence-based supported employment for adults with severe and persistent mental illness.

PubMed

Waghorn, Geoffrey; Dias, Shannon; Gladman, Beverley; Harris, Meredith; Saha, Sukanta

2014-12-01

The Individual Placement and Support (IPS) approach is an evidence-based form of supported employment for people with severe and persistent mental illness. This approach is not yet widely available in Australia even though there is mounting evidence of its generalisability outside the USA. One previous Australian randomised controlled trial found that IPS is effective for young people with first episode psychosis. The aim of the current trial was to assess the effectiveness of evidence-based supported employment when implemented for Australian adult consumers of public mental health services by utilising existing service systems. A four-site randomised control trial design (n = 208) was conducted in Brisbane (two sites), Townsville and Cairns. The intervention consisted of an IPS supported employment service hosted by a community mental health team. The control condition was delivered at each site by mental health teams referring consumers to other disability employment services in the local area. At 12 months, those in the IPS condition had 2.4 times greater odds of commencing employment than those in the control condition (42.5% vs. 23.5%). The conditions did not differ on secondary employment outcomes including job duration, hours worked, or job diversity. Attrition was higher than expected in both conditions with 28.4% completing the baseline interview but taking no further part in the study. The results support previous international findings that IPS-supported employment is more effective than non-integrated supported employment. IPS can be successfully implemented this way in Australia, but with a loss of effect strength compared to previous USA trials. © 2014 Occupational Therapy Australia.

To create a cleanroom controlled environment using a mobile air decontamination unit for the preparation of antineoplastic drugs.

PubMed

Lecordier, Julien; Plivard, Claire; Gardeux, Michel; Daouadi, Karim; Lahet, Jean-Jacques

2016-02-01

To use a mobile air decontamination unit (MADU) for a microbial destruction and decreased particle burden making a cleanroom controlled environment in a Centralized Chemotherapy Preparation Unit (CCPU). Good manufacturing practices (GMP) in France specify that the ambient air in the vicinity of a class III biosafety cabinet (isolator) complies with air cleanliness ISO 8 level in CCPU. This guideline has a significant impact because implementing a dedicated air handling unit (AHU) brings some engineering constraints and generates substantial additional costs. Authors have previously studied some technical and economical aspects to evaluate the feasibility of the MADU option. Using a MADU was the chosen option. Qualification of the CCPU showed that results were in compliance with the French GMP. After one year of use, the efficiency of the MADU was confirmed. According to these results, using a MADU constitutes a beneficial option for CCPU previously equipped with an isolator when compared to renovation work involving a standard built-in AHU. © The Author(s) 2014.

Fast machine-learning online optimization of ultra-cold-atom experiments.

PubMed

Wigley, P B; Everitt, P J; van den Hengel, A; Bastian, J W; Sooriyabandara, M A; McDonald, G D; Hardman, K S; Quinlivan, C D; Manju, P; Kuhn, C C N; Petersen, I R; Luiten, A N; Hope, J J; Robins, N P; Hush, M R

2016-05-16

We apply an online optimization process based on machine learning to the production of Bose-Einstein condensates (BEC). BEC is typically created with an exponential evaporation ramp that is optimal for ergodic dynamics with two-body s-wave interactions and no other loss rates, but likely sub-optimal for real experiments. Through repeated machine-controlled scientific experimentation and observations our 'learner' discovers an optimal evaporation ramp for BEC production. In contrast to previous work, our learner uses a Gaussian process to develop a statistical model of the relationship between the parameters it controls and the quality of the BEC produced. We demonstrate that the Gaussian process machine learner is able to discover a ramp that produces high quality BECs in 10 times fewer iterations than a previously used online optimization technique. Furthermore, we show the internal model developed can be used to determine which parameters are essential in BEC creation and which are unimportant, providing insight into the optimization process of the system.

Fast machine-learning online optimization of ultra-cold-atom experiments

PubMed Central

Wigley, P. B.; Everitt, P. J.; van den Hengel, A.; Bastian, J. W.; Sooriyabandara, M. A.; McDonald, G. D.; Hardman, K. S.; Quinlivan, C. D.; Manju, P.; Kuhn, C. C. N.; Petersen, I. R.; Luiten, A. N.; Hope, J. J.; Robins, N. P.; Hush, M. R.

2016-01-01

We apply an online optimization process based on machine learning to the production of Bose-Einstein condensates (BEC). BEC is typically created with an exponential evaporation ramp that is optimal for ergodic dynamics with two-body s-wave interactions and no other loss rates, but likely sub-optimal for real experiments. Through repeated machine-controlled scientific experimentation and observations our ‘learner’ discovers an optimal evaporation ramp for BEC production. In contrast to previous work, our learner uses a Gaussian process to develop a statistical model of the relationship between the parameters it controls and the quality of the BEC produced. We demonstrate that the Gaussian process machine learner is able to discover a ramp that produces high quality BECs in 10 times fewer iterations than a previously used online optimization technique. Furthermore, we show the internal model developed can be used to determine which parameters are essential in BEC creation and which are unimportant, providing insight into the optimization process of the system. PMID:27180805

A novel mitochondrial carrier protein Mme1 acts as a yeast mitochondrial magnesium exporter.

PubMed

Cui, Yixian; Zhao, Shanke; Wang, Juan; Wang, Xudong; Gao, Bingquan; Fan, Qiangwang; Sun, Fei; Zhou, Bing

2015-03-01

The homeostasis of magnesium (Mg2+), an abundant divalent cation indispensable for many biological processes including mitochondrial functions, is underexplored. Previously, two mitochondrial Mg2+ importers, Mrs2 and Lpe10, were characterized for mitochondrial Mg2+ uptake. We now show that mitochondrial Mg2+ homeostasis is accurately controlled through the combined effects of previously known importers and a novel exporter, Mme1 (mitochondrial magnesium exporter 1). Mme1 belongs to the mitochondrial carrier family and was isolated for its mutation that is able to suppress the mrs2Δ respiration defect. Deletion of MME1 significantly increased steady-state mitochondrial Mg2+ concentration, while overexpression decreased it. Measurements of Mg2+ exit from proteoliposomes reconstituted with purified Mme1 provided definite evidence for Mme1 as an Mg2+ exporter. Our studies identified, for the first time, a mitochondrial Mg2+ exporter that works together with mitochondrial importers to ensure the precise control of mitochondrial Mg2+ homeostasis. Copyright © 2015 Elsevier B.V. All rights reserved.

Examining paid sickness absence by shift workers.

PubMed

Catano, V M; Bissonnette, A B

2014-06-01

Shift workers are at greater risk than day workers with respect to psychological and physical health, yet little research has linked shift work to increased sickness absence. To investigate the relationship between shift work and sickness absence while controlling for organizational and individual characteristics and shift work attributes that have confounded previous research. The study used archive data collected from three national surveys in Canada, each involving over 20000 employees and 6000 private-sector firms in 14 different occupational groups. The employees reported the number of paid sickness absence days in the past 12 months. Data were analysed using both chi-squared statistics and hierarchical regressions. Contrary to previous research, shift workers took less paid sickness absence than day workers. There were no differences in the length of the sickness absence between both groups or in sickness absence taken by female and male workers whether working days or shifts. Only job tenure, the presence of a union in the workplace and working rotating shifts predicted sickness absence in shift workers. The results were consistent across all three samples. In general, shift work does not seem to be linked to increased sickness absence. However, such associations may be true for specific industries. Male and female workers did not differ in the amount of sickness absence taken. Rotating shifts, regardless of industry, predicted sickness absence among shift workers. Consideration should be given to implementing scheduled time off between shift changes. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Surgical management of first branchial cleft anomaly presenting as infected retroauricular mass using a microscopic dissection technique.

PubMed

Chan, Kai-Chieh; Chao, Wei-Chieh; Wu, Che-Ming

2012-01-01

This is a detailed description of the clinical and anatomical presentation of the first branchial cleft anomaly presenting as retroauricular infected mass. Our experience with a microscopic dissection with control of the sinus lumen from within the cyst is also described. Between 2001 and 2008, patients with the final histologic diagnosis of first branchial cleft anomaly in the retroauricular area were managed with a microscopic dissection technique with control of the sinus lumen from within the cyst. Classifications were done in accordance with Work, Olsen, and Chilla. Outcomes measured intervention as a function of disease recurrence and complications including facial nerve function was used. Eight patients with a mean age of 14.2 years were enrolled, and this included 4 females and 4 males. Four type 1 and 4 type 2 lesions as per the Work's and Chilla's classification were found, and there were 5 sinuses, 2 fistulae, and 1 cyst according to Olsen's classification. All patients presented to the department with acute infection at the time of diagnosis. Five of the 8 patients had previous surgical treatment, 2 of those had up to 3 previous operations. None of the patients were complicated by disease recurrence or had surgical related complications (facial nerve paresis or paralysis, infection, canal stenosis) requiring reoperation with more than 1 year of follow-up. First branchial cleft anomaly presenting as retroauricular infected mass can be effectively treated by adopting a microscopic dissection technique with control of the sinus lumen from within the cyst. Copyright © 2012 Elsevier Inc. All rights reserved.

African Easterly Jet: Structure and Maintenance

NASA Technical Reports Server (NTRS)

Wu, Man-Li C.; Reale, Oreste; Schubert, Siegfried D.; Suarez, Max J.; Koster, Randy D.; Pegion, Philip J.

2009-01-01

This article investigates the African Easterly Jet (AEJ), its structure and the forcings contributing to its maintenance, critically revisiting previous work which attributed the maintenance of the jet to soil moisture gradients over tropical Africa. A state-of-the-art global model in a high-end computer framework is used to produce a 3-member 73-year ensemble run forced by observed SST to represent the Control run. The AEJ as produced by the Control is compared with the representation of the AEJ in the European Center for Medium Range Forecast Reanalyses (ERA-40) and other observational data sets and found very realistic. Five Experiments are then performed, each represented by sets of 3-member 22 year long (1980-2001) ensemble runs. The goal of the Experiments is to investigate the role of meridional soil moisture gradients, different land surface properties and orography. Unlike previous studies, which have suppressed soil moisture gradients within a highly idealized framework (i.e., the so-called bucket model), terrestrial evaporation control is here achieved with a highly sophisticated landsurface treatment and with an extensively tested and complex methodology. The results show that the AEJ is suppressed by a combination of absence of meridional evaporation gradients over Africa and constant vegetation, even if the individual forcings taken separately do not lead to the AEJ disappearance, but only its modification. Moreover, the suppression of orography also leads to a different circulation in which there is no AEJ. This work suggests that it is not just soil moisture gradients, but a unique combination of geographical features present only in northern tropical Africa, which causes and maintains the jet.

A two-phase model of resource allocation in visual working memory.

PubMed

Ye, Chaoxiong; Hu, Zhonghua; Li, Hong; Ristaniemi, Tapani; Liu, Qiang; Liu, Taosheng

2017-10-01

Two broad theories of visual working memory (VWM) storage have emerged from current research, a discrete slot-based theory and a continuous resource theory. However, neither the discrete slot-based theory or continuous resource theory clearly stipulates how the mental commodity for VWM (discrete slot or continuous resource) is allocated. Allocation may be based on the number of items via stimulus-driven factors, or it may be based on task demands via voluntary control. Previous studies have obtained conflicting results regarding the automaticity versus controllability of such allocation. In the current study, we propose a two-phase allocation model, in which the mental commodity could be allocated only by stimulus-driven factors in the early consolidation phase. However, when there is sufficient time to complete the early phase, allocation can enter the late consolidation phase, where it can be flexibly and voluntarily controlled according to task demands. In an orientation recall task, we instructed participants to store either fewer items at high-precision or more items at low-precision. In 3 experiments, we systematically manipulated memory set size and exposure duration. We did not find an effect of task demands when the set size was high and exposure duration was short. However, when we either decreased the set size or increased the exposure duration, we found a trade-off between the number and precision of VWM representations. These results can be explained by a two-phase model, which can also account for previous conflicting findings in the literature. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Intrinsic Sensing and Evolving Internal Model Control of Compact Elastic Module for a Lower Extremity Exoskeleton

PubMed Central

Wang, Likun; Du, Zhijiang; Dong, Wei; Shen, Yi; Zhao, Guangyu

2018-01-01

To achieve strength augmentation, endurance enhancement, and human assistance in a functional autonomous exoskeleton, control precision, back drivability, low output impedance, and mechanical compactness are desired. In our previous work, two elastic modules were designed for human–robot interaction sensing and compliant control, respectively. According to the intrinsic sensing properties of the elastic module, in this paper, only one compact elastic module is applied to realize both purposes. Thus, the corresponding control strategy is required and evolving internal model control is proposed to address this issue. Moreover, the input signal to the controller is derived from the deflection of the compact elastic module. The human–robot interaction is considered as the disturbance which is approximated by the output error between the exoskeleton control plant and evolving forward learning model. Finally, to verify our proposed control scheme, several experiments are conducted with our robotic exoskeleton system. The experiment shows a satisfying result and promising application feasibility. PMID:29562684

Intrinsic Sensing and Evolving Internal Model Control of Compact Elastic Module for a Lower Extremity Exoskeleton.

PubMed

Wang, Likun; Du, Zhijiang; Dong, Wei; Shen, Yi; Zhao, Guangyu

2018-03-19

To achieve strength augmentation, endurance enhancement, and human assistance in a functional autonomous exoskeleton, control precision, back drivability, low output impedance, and mechanical compactness are desired. In our previous work, two elastic modules were designed for human-robot interaction sensing and compliant control, respectively. According to the intrinsic sensing properties of the elastic module, in this paper, only one compact elastic module is applied to realize both purposes. Thus, the corresponding control strategy is required and evolving internal model control is proposed to address this issue. Moreover, the input signal to the controller is derived from the deflection of the compact elastic module. The human-robot interaction is considered as the disturbance which is approximated by the output error between the exoskeleton control plant and evolving forward learning model. Finally, to verify our proposed control scheme, several experiments are conducted with our robotic exoskeleton system. The experiment shows a satisfying result and promising application feasibility.

Pseudo-spectral control of a novel oscillating surge wave energy converter in regular waves for power optimization including load reduction

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

Tom, Nathan M.; Yu, Yi -Hsiang; Wright, Alan D.

The aim of this study is to describe a procedure to maximize the power-to-load ratio of a novel wave energy converter (WEC) that combines an oscillating surge wave energy converter with variable structural components. The control of the power-take-off torque will be on a wave-to-wave timescale, whereas the structure will be controlled statically such that the geometry remains the same throughout the wave period. Linear hydrodynamic theory is used to calculate the upper and lower bounds for the time-averaged absorbed power and surge foundation loads while assuming that the WEC motion remains sinusoidal. Previous work using pseudo-spectral techniques to solvemore » the optimal control problem focused solely on maximizing absorbed energy. This work extends the optimal control problem to include a measure of the surge foundation force in the optimization. The objective function includes two competing terms that force the optimizer to maximize power capture while minimizing structural loads. A penalty weight was included with the surge foundation force that allows control of the optimizer performance based on whether emphasis should be placed on power absorption or load shedding. Results from pseudo-spectral optimal control indicate that a unit reduction in time-averaged power can be accompanied by a greater reduction in surge-foundation force.« less

Pseudo-spectral control of a novel oscillating surge wave energy converter in regular waves for power optimization including load reduction

DOE PAGES

Tom, Nathan M.; Yu, Yi -Hsiang; Wright, Alan D.; ...

2017-04-18

The aim of this study is to describe a procedure to maximize the power-to-load ratio of a novel wave energy converter (WEC) that combines an oscillating surge wave energy converter with variable structural components. The control of the power-take-off torque will be on a wave-to-wave timescale, whereas the structure will be controlled statically such that the geometry remains the same throughout the wave period. Linear hydrodynamic theory is used to calculate the upper and lower bounds for the time-averaged absorbed power and surge foundation loads while assuming that the WEC motion remains sinusoidal. Previous work using pseudo-spectral techniques to solvemore » the optimal control problem focused solely on maximizing absorbed energy. This work extends the optimal control problem to include a measure of the surge foundation force in the optimization. The objective function includes two competing terms that force the optimizer to maximize power capture while minimizing structural loads. A penalty weight was included with the surge foundation force that allows control of the optimizer performance based on whether emphasis should be placed on power absorption or load shedding. Results from pseudo-spectral optimal control indicate that a unit reduction in time-averaged power can be accompanied by a greater reduction in surge-foundation force.« less

Training Working Memory in Childhood Enhances Coupling between Frontoparietal Control Network and Task-Related Regions.

PubMed

Barnes, Jessica J; Nobre, Anna Christina; Woolrich, Mark W; Baker, Kate; Astle, Duncan E

2016-08-24

Working memory is a capacity upon which many everyday tasks depend and which constrains a child's educational progress. We show that a child's working memory can be significantly enhanced by intensive computer-based training, relative to a placebo control intervention, in terms of both standardized assessments of working memory and performance on a working memory task performed in a magnetoencephalography scanner. Neurophysiologically, we identified significantly increased cross-frequency phase amplitude coupling in children who completed training. Following training, the coupling between the upper alpha rhythm (at 16 Hz), recorded in superior frontal and parietal cortex, became significantly coupled with high gamma activity (at ∼90 Hz) in inferior temporal cortex. This altered neural network activity associated with cognitive skill enhancement is consistent with a framework in which slower cortical rhythms enable the dynamic regulation of higher-frequency oscillatory activity related to task-related cognitive processes. Whether we can enhance cognitive abilities through intensive training is one of the most controversial topics of cognitive psychology in recent years. This is particularly controversial in childhood, where aspects of cognition, such as working memory, are closely related to school success and are implicated in numerous developmental disorders. We provide the first neurophysiological account of how working memory training may enhance ability in childhood, using a brain recording technique called magnetoencephalography. We borrowed an analysis approach previously used with intracranial recordings in adults, or more typically in other animal models, called "phase amplitude coupling." Copyright © 2016 Barnes et al.

Training Working Memory in Childhood Enhances Coupling between Frontoparietal Control Network and Task-Related Regions

PubMed Central

Barnes, Jessica J.; Nobre, Anna Christina; Woolrich, Mark W.; Baker, Kate

2016-01-01

Working memory is a capacity upon which many everyday tasks depend and which constrains a child's educational progress. We show that a child's working memory can be significantly enhanced by intensive computer-based training, relative to a placebo control intervention, in terms of both standardized assessments of working memory and performance on a working memory task performed in a magnetoencephalography scanner. Neurophysiologically, we identified significantly increased cross-frequency phase amplitude coupling in children who completed training. Following training, the coupling between the upper alpha rhythm (at 16 Hz), recorded in superior frontal and parietal cortex, became significantly coupled with high gamma activity (at ∼90 Hz) in inferior temporal cortex. This altered neural network activity associated with cognitive skill enhancement is consistent with a framework in which slower cortical rhythms enable the dynamic regulation of higher-frequency oscillatory activity related to task-related cognitive processes. SIGNIFICANCE STATEMENT Whether we can enhance cognitive abilities through intensive training is one of the most controversial topics of cognitive psychology in recent years. This is particularly controversial in childhood, where aspects of cognition, such as working memory, are closely related to school success and are implicated in numerous developmental disorders. We provide the first neurophysiological account of how working memory training may enhance ability in childhood, using a brain recording technique called magnetoencephalography. We borrowed an analysis approach previously used with intracranial recordings in adults, or more typically in other animal models, called “phase amplitude coupling.” PMID:27559180

The Association of Workplace Psychosocial Factors and Musculoskeletal Pain Among Korean Emotional Laborers.

PubMed

Baek, Kiook; Yang, Seonhee; Lee, Miyoung; Chung, Insung

2018-06-01

Many studies have reported negative psychological or physical effects of emotional labor. Relationship between work-related musculoskeletal disorder and psychosocial factors has been reported. To manage organizational and psychosocial factors of musculoskeletal disorder with work place intervention among emotional laborers, the factors contributing to musculoskeletal pain must be identified and clarified. Data from the fourth Korean Working Conditions Survey was analyzed. Based on the questionnaire, we selected emotional laborers and included 3,979 participants, excluding participants whose variables were of interest to the researcher. Weight variable was applied. The association with musculoskeletal pain and psychosocial factors, such as workload, monotonous work, job control, social support, and job satisfaction, was investigated. Univariate analysis demonstrated that there was a statistically significant relationship between social support, job satisfaction, and musculoskeletal pain. In multivariate analysis, job satisfaction showed a strong correlation with musculoskeletal pain at all sites. Social support was significantly associated with backache. Monotonous work seemed to reduce the pain in the neck and/or upper limbs. Job control and work intensity were not significantly associated with musculoskeletal pain. In this study, job satisfaction was significantly associated with musculoskeletal pain, and social support among the social psychological stressors could reduce musculoskeletal pain. However, unlike previously known, the presence of monotonous work resulted in reduced musculoskeletal pain. The results of this study will help to establish the direction of improvement of atmosphere in the workplace to prevent the musculoskeletal pain of emotional laborers.

Flow Physics of Synthetic Jet Interactions on a Sweptback Model with a Control Surface

NASA Astrophysics Data System (ADS)

Monastero, Marianne; Amitay, Michael

2016-11-01

Active flow control using synthetic jets can be used on aerodynamic surfaces to improve performance and increase fuel efficiency. The flowfield resulting from the interaction of the jets with a separated crossflow with a spanwise component must be understood to determine actuator spacing for aircraft integration. The current and previous work showed adjacent synthetic jets located upstream of a control surface hingeline on a sweptback model interact with each other under certain conditions. Whether these interactions are constructive or destructive is dependent on the spanwise spacing of the jets, the severity of separation over the control surface, and the magnitude of the spanwise flow. Measuring and understanding the detailed flow physics of the flow structures emanating from the synthetic jet orifices and their interactions with adjacent jets of varying spacings is the focus of this work. Wind tunnel experiments were conducted at the Rensselaer Polytechnic Institute Subsonic Wind Tunnel using stereo particle image velocimetry (SPIV) and pressure measurements to study the effect that varying the spanwise spacing has on the overall performance. Initial SPIV data gave insight into defining and understanding the mechanisms behind the beneficial or detrimental jets interactions.

Active room compensation for sound reinforcement using sound field separation techniques.

PubMed

Heuchel, Franz M; Fernandez-Grande, Efren; Agerkvist, Finn T; Shabalina, Elena

2018-03-01

This work investigates how the sound field created by a sound reinforcement system can be controlled at low frequencies. An indoor control method is proposed which actively absorbs the sound incident on a reflecting boundary using an array of secondary sources. The sound field is separated into incident and reflected components by a microphone array close to the secondary sources, enabling the minimization of reflected components by means of optimal signals for the secondary sources. The method is purely feed-forward and assumes constant room conditions. Three different sound field separation techniques for the modeling of the reflections are investigated based on plane wave decomposition, equivalent sources, and the Spatial Fourier transform. Simulations and an experimental validation are presented, showing that the control method performs similarly well at enhancing low frequency responses with the three sound separation techniques. Resonances in the entire room are reduced, although the microphone array and secondary sources are confined to a small region close to the reflecting wall. Unlike previous control methods based on the creation of a plane wave sound field, the investigated method works in arbitrary room geometries and primary source positions.

Do positive psychology exercises work? A replication of Seligman et al. (2005).

PubMed

Mongrain, Myriam; Anselmo-Matthews, Tracy

2012-04-01

The current work replicated a landmark study conducted by Seligman and colleagues (2005) that demonstrated the long-term benefits of positive psychology exercises (PPEs). In the original study, two exercises administered over 1 week ("Three Good Things" and "Using your Signature Strengths in a New Way") were found to have long-lasting effects on depression and happiness (Seligman, Steen, Park, & Peterson, 2005). These exercises were tested here using the same methodology except for improvements to the control condition, and the addition of a second "positive placebo" to isolate the common factor of accessing positive, self-relevant constructs. This component control design was meant to assess the effect of expectancies for success (expectancy control), as well the cognitive access of positive information about the self (positive placebo). Repeated measures analyses showed that the PPEs led to lasting increases in happiness, as did the positive placebo. The PPEs did not exceed the control condition in producing changes in depression over time. Brief, positive psychology interventions may boost happiness through a common factor involving the activation of positive, self-relevant information rather than through other specific mechanisms. Finally, the effects of PPEs on depression may be more modest than previously assumed. © 2012 Wiley Periodicals, Inc.

Defect quasi Fermi level control-based CN reduction in GaN: Evidence for the role of minority carriers

NASA Astrophysics Data System (ADS)

Reddy, Pramod; Kaess, Felix; Tweedie, James; Kirste, Ronny; Mita, Seiji; Collazo, Ramon; Sitar, Zlatko

2017-10-01

Compensating point defect reduction in wide bandgap semiconductors is possible by above bandgap illumination based defect quasi Fermi level (dQFL) control. The point defect control technique employs excess minority carriers that influence the dQFL of the compensator, increase the corresponding defect formation energy, and consequently are responsible for point defect reduction. Previous studies on various defects in GaN and AlGaN have shown good agreement with the theoretical model, but no direct evidence for the role of minority carriers was provided. In this work, we provide direct evidence for the role of minority carriers in reducing point defects by studying the predicted increase in work done against defect (CN-1) formation with the decrease in the Fermi level (free carrier concentration) in Si doped GaN at a constant illumination intensity. Comparative defect photoluminescence measurements on illuminated and dark regions of GaN show an excellent quantitative agreement with the theory by exhibiting a greater reduction in yellow luminescence attributed to CN-1 at lower doping, thereby providing conclusive evidence for the role of the minority carriers in Fermi level control-based point defect reduction.

Socio-psychological stressors as risk factors for low back pain in Chinese middle-aged women.

PubMed

Yip, Y B; Ho, S C; Chan, S G

2001-11-01

This study aims to explore the relationship between socio-psychological stress and low back pain (LBP) prevalence among Chinese middle-aged women. Women in mid-life experience increasing socio-psychological stress because of midlife transitions, stressful life events and housework or work factors. Encountering socio-psychological stress itself may result in the manifestation of LBP. A case-control study of Hong Kong community-based middle-aged women was conducted. The study subjects were either from the University Family Medicine Clinic or from a previous population-based cross-sectional study of middle-aged women conducted by Department of Community and Family Medicine. Among the 928 potential eligible subjects from both sources, a total of 182 cases and 235 controls participated in this study. Data were collected from face-to-face interviews and included demographic factors, menopausal status, socio-psychological stress and occurrence of LBP. Socio-psychological stress covered social factors, self-reported nature of housework/work, housework/work stress and stressful life events. Among the 182 cases who entered this study, 83 women (45.6%) had experienced 1-<14 days of LBP, and 99 women (54.4%) had at least 14 days of LBP in the previous 12 months. Those who reported that 'their family members, relatives or friends were very sick, died, needed her to take care of them or who they worried about in the past 12 months' had an increased risk of LBP of 67% (95% confidence interval (CI) 1.09-2.55). In addition women with a bad or ordinary relationship with cohabitants had an increased risk of LBP of 70% (95% CI 1.00-3.04). Lastly, women with a high housework or work stress had an increased risk of suffering both types of LBP of nearly two- and half-fold (95% CI 1.61-3.85). The results indicate that an association exists between high socio-psychological stress and LBP prevalence. Alleviating the impact of housework or work related factors would, however, involve improving both the work and home environment.

Verrucomicrobia and their role in soil methanol consumption

NASA Astrophysics Data System (ADS)

Fierer, N.

2015-12-01

Bacteria belonging to the phylum Verrucomicrobia are far more ubiquitous and abundant in soil than previous work would suggest. In many soils, a relatively small number of verrucomicrobial phylotypes or 'species' can represent more than 25% of the bacterial cells in soil. Since these phylotypes are not closely related to any known cultured isolates or any strains for which we have whole-genome data, we have limited information on what these bacteria are actually doing in soil, their metabolic capabilities, or the niches they inhabit. We have recently assembled the genomes of these dominant Verrucomicrobia from soil metagenomic data and found that these taxa appear to be oligotrophs that specialize in methanol oxidation. This is important because we have found in previous work that methanol likely represents an important source of labile organic carbon to soil microbes in many ecosystems with methanol fluxes likely representing an important, but under-studied, mechanism by which organic carbon is transferred from surface litter layers to mineral soils. Ongoing work has focused on using high-throughput cultivation methods to study soil Verrucomicrobia in vitro and better understand their controls on soil carbon dynamics. Together this work demonstrates how we can leverage recent methodological advances in metagenomics, high-throughput cultivation, and soil trace gas analyses to understand the biogeochemical relevance of an abundant, but mysterious, group of soil microorganisms.

Mechanical Validation of an MRI Compatible Stereotactic Neurosurgery Robot in Preparation for Pre-Clinical Trials.

PubMed

Nycz, Christopher J; Gondokaryono, Radian; Carvalho, Paulo; Patel, Nirav; Wartenberg, Marek; Pilitsis, Julie G; Fischer, Gregory S

2017-09-01

The use of magnetic resonance imaging (MRI) for guiding robotic surgical devices has shown great potential for performing precisely targeted and controlled interventions. To fully realize these benefits, devices must work safely within the tight confines of the MRI bore without negatively impacting image quality. Here we expand on previous work exploring MRI guided robots for neural interventions by presenting the mechanical design and assessment of a device for positioning, orienting, and inserting an interstitial ultrasound-based ablation probe. From our previous work we have added a 2 degree of freedom (DOF) needle driver for use with the aforementioned probe, revised the mechanical design to improve strength and function, and performed an evaluation of the mechanism's accuracy and effect on MR image quality. The result of this work is a 7-DOF MRI robot capable of positioning a needle tip and orienting it's axis with accuracy of 1.37 ± 0.06 mm and 0.79° ± 0.41°, inserting it along it's axis with an accuracy of 0.06 ± 0.07 mm , and rotating it about it's axis to an accuracy of 0.77° ± 1.31°. This was accomplished with no significant reduction in SNR caused by the robot's presence in the MRI bore, ≤ 10.3% reduction in SNR from running the robot's motors during a scan, and no visible paramagnetic artifacts.

Model-based Bayesian signal extraction algorithm for peripheral nerves

NASA Astrophysics Data System (ADS)

Eggers, Thomas E.; Dweiri, Yazan M.; McCallum, Grant A.; Durand, Dominique M.

2017-10-01

Objective. Multi-channel cuff electrodes have recently been investigated for extracting fascicular-level motor commands from mixed neural recordings. Such signals could provide volitional, intuitive control over a robotic prosthesis for amputee patients. Recent work has demonstrated success in extracting these signals in acute and chronic preparations using spatial filtering techniques. These extracted signals, however, had low signal-to-noise ratios and thus limited their utility to binary classification. In this work a new algorithm is proposed which combines previous source localization approaches to create a model based method which operates in real time. Approach. To validate this algorithm, a saline benchtop setup was created to allow the precise placement of artificial sources within a cuff and interference sources outside the cuff. The artificial source was taken from five seconds of chronic neural activity to replicate realistic recordings. The proposed algorithm, hybrid Bayesian signal extraction (HBSE), is then compared to previous algorithms, beamforming and a Bayesian spatial filtering method, on this test data. An example chronic neural recording is also analyzed with all three algorithms. Main results. The proposed algorithm improved the signal to noise and signal to interference ratio of extracted test signals two to three fold, as well as increased the correlation coefficient between the original and recovered signals by 10-20%. These improvements translated to the chronic recording example and increased the calculated bit rate between the recovered signals and the recorded motor activity. Significance. HBSE significantly outperforms previous algorithms in extracting realistic neural signals, even in the presence of external noise sources. These results demonstrate the feasibility of extracting dynamic motor signals from a multi-fascicled intact nerve trunk, which in turn could extract motor command signals from an amputee for the end goal of controlling a prosthetic limb.

Reinforcement Probability Modulates Temporal Memory Selection and Integration Processes

PubMed Central

Matell, Matthew S.; Kurti, Allison N.

2013-01-01

We have previously shown that rats trained in a mixed-interval peak procedure (tone = 4s, light = 12s) respond in a scalar manner at a time in between the trained peak times when presented with the stimulus compound (Swanton & Matell, 2011). In our previous work, the two component cues were reinforced with different probabilities (short = 20%, long = 80%) to equate response rates, and we found that the compound peak time was biased toward the cue with the higher reinforcement probability. Here, we examined the influence that different reinforcement probabilities have on the temporal location and shape of the compound response function. We found that the time of peak responding shifted as a function of the relative reinforcement probability of the component cues, becoming earlier as the relative likelihood of reinforcement associated with the short cue increased. However, as the relative probabilities of the component cues grew dissimilar, the compound peak became non-scalar, suggesting that the temporal control of behavior shifted from a process of integration to one of selection. As our previous work has utilized durations and reinforcement probabilities more discrepant than those used here, these data suggest that the processes underlying the integration/selection decision for time are based on cue value. PMID:23896560

Control theory based airfoil design for potential flow and a finite volume discretization

NASA Technical Reports Server (NTRS)

Reuther, J.; Jameson, A.

1994-01-01

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In previous studies it was shown that control theory could be used to devise an effective optimization procedure for two-dimensional profiles in which the shape is determined by a conformal transformation from a unit circle, and the control is the mapping function. The goal of our present work is to develop a method which does not depend on conformal mapping, so that it can be extended to treat three-dimensional problems. Therefore, we have developed a method which can address arbitrary geometric shapes through the use of a finite volume method to discretize the potential flow equation. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented, where both target speed distributions and minimum drag are used as objective functions.

Experimental study of adaptive pointing and tracking for large flexible space structures

NASA Technical Reports Server (NTRS)

Boussalis, D.; Bayard, D. S.; Ih, C.; Wang, S. J.; Ahmed, A.

1991-01-01

This paper describes an experimental study of adaptive pointing and tracking control for flexible spacecraft conducted on a complex ground experiment facility. The algorithm used in this study is based on a multivariable direct model reference adaptive control law. Several experimental validation studies were performed earlier using this algorithm for vibration damping and robust regulation, with excellent results. The current work extends previous studies by addressing the pointing and tracking problem. As is consistent with an adaptive control framework, the plant is assumed to be poorly known to the extent that only system level knowledge of its dynamics is available. Explicit bounds on the steady-state pointing error are derived as functions of the adaptive controller design parameters. It is shown that good tracking performance can be achieved in an experimental setting by adjusting adaptive controller design weightings according to the guidelines indicated by the analytical expressions for the error.

Transactive Control of Commercial Building HVAC Systems

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

Corbin, Charles D.; Makhmalbaf, Atefe; Huang, Sen

This document details the development and testing of market-based transactive controls for building heating, ventilating and air conditioning (HVAC) systems. These controls are intended to serve the purposes of reducing electricity use through conservation, reducing peak building electric demand, and providing demand flexibility to assist with power system operations. This report is the summary of the first year of work conducted under Phase 1 of the Clean Energy and Transactive Campus Project. The methods and techniques described here were first investigated in simulation, and then subsequently deployed to a physical testbed on the Pacific Northwest National Laboratory (PNNL) campus formore » validation. In this report, we describe the models and control algorithms we have developed, testing of the control algorithms in simulation, and deployment to a physical testbed. Results from physical experiments support previous simulation findings, and provide insights for further improvement.« less

Probabilistic DHP adaptive critic for nonlinear stochastic control systems.

PubMed

Herzallah, Randa

2013-06-01

Following the recently developed algorithms for fully probabilistic control design for general dynamic stochastic systems (Herzallah & Káarnáy, 2011; Kárný, 1996), this paper presents the solution to the probabilistic dual heuristic programming (DHP) adaptive critic method (Herzallah & Káarnáy, 2011) and randomized control algorithm for stochastic nonlinear dynamical systems. The purpose of the randomized control input design is to make the joint probability density function of the closed loop system as close as possible to a predetermined ideal joint probability density function. This paper completes the previous work (Herzallah & Káarnáy, 2011; Kárný, 1996) by formulating and solving the fully probabilistic control design problem on the more general case of nonlinear stochastic discrete time systems. A simulated example is used to demonstrate the use of the algorithm and encouraging results have been obtained. Copyright © 2013 Elsevier Ltd. All rights reserved.

Diet and Exercise in Parenthood: A Social Control Perspective

PubMed Central

Reczek, Corinne; Beth Thomeer, Mieke; Lodge, Amy C.; Umberson, Debra; Underhill, Megan

2014-01-01

Previous work on social control—the direct and indirect regulation of an individual’s health behaviors by others—suggests that parent–child relationships promote healthy diet and exercise. Yet parenthood is associated with less healthy diet and exercise patterns. The authors investigated this paradox by examining social control processes in 40 in-depth interviews with mothers and fathers. They found that parenthood involves social control processes that both promote and compromise healthy behavior, contributing to contradictory perceived effects of parenthood on health behavior. Moreover, the dynamics of social control appear to unfold in different ways for mothers and fathers and depend on the child’s gender and life stage, suggesting that gender and age dyads are central to understanding the seemingly contradictory consequences of parenthood at the population level. These articulations of gendered social control processes provide new insight into the consequences of the gendered organization of parenthood for diet and exercise. PMID:25328244

Toward agile control of a flexible-spine model for quadruped bounding

NASA Astrophysics Data System (ADS)

Byl, Katie; Satzinger, Brian; Strizic, Tom; Terry, Pat; Pusey, Jason

2015-05-01

Legged systems should exploit non-steady gaits both for improved recovery from unexpected perturbations and also to enlarge the set of reachable states toward negotiating a range of known upcoming terrain obstacles. We present a 4-link planar, bounding, quadruped model with compliance in its legs and spine and describe design of an intuitive and effective low-level gait controller. We extend our previous work on meshing hybrid dynamic systems and demonstrate that our control strategy results in stable gaits with meshable, low-dimension step- to-step variability. This meshability is a first step toward enabling switching control, to increase stability after perturbations compared with any single gait control, and we describe how this framework can also be used to find the set of n-step reachable states. Finally, we propose new guidelines for quantifying "agility" for legged robots, providing a preliminary framework for quantifying and improving performance of legged systems.

Psychological Detachment from Work during Off-job Time: Predictive Role of Work and Non-work Factors in Japanese Employees

PubMed Central

SHIMAZU, Akihito; DE JONGE, Jan; KUBOTA, Kazumi; KAWAKAMI, Norito

2014-01-01

Psychological detachment from work, an off-job experience of “switching off” mentally, seems to be crucial for promoting employee’s well-being. Previous studies on predictors of psychological detachment mainly focused on job-related factors, and only a few studies focused on family-related and personal factors. This study focuses not only on job-related factors (job demands, job control, workplace support) but also on family-related (family/friend support) and personal factors (workaholism), and examines the relation of these three factors with psychological detachment. Data of 2,520 Japanese employees was randomly split into two groups and then analyzed using cross-validation. Hierarchical multiple regression analyses revealed that family/friend support had a positive association with psychological detachment, whereas a subscale of workaholism (i.e. working compulsively) had negative associations with it across the two groups. Results suggest that family/friend support would facilitate psychological detachment whereas workaholism would inhibit it. PMID:24492761

Metallurgical Research Relating to the Development of Metals and Alloys for Use in the High-Temperature Components of Jet-Engines, Gas Turbines and Other Aircraft Propulsion Systems

NASA Technical Reports Server (NTRS)

1948-01-01

Considerable work has been done on report preparation. All items listed in the March program report will be reported during July. Fundamental studies are in progress to establish the fundamental processes by which treatments and composition control properties of commercial alloys at high temperatures. As yet work has been confined to Low-Carbon N155 alloy and progress has been reported twice previously. The work is divided into two sections: studies of solution treated and aged material and studies of rolled structures. Electron microscopic work has been started as an additional technique for the studies. Brief descriptions of experimental techniques used, results, and interpretation of the data obtained since the last report covering this field are summarized below. Since the work outlined is to a large extent still in progress, the discussion given is to be considered tentative and subject to further modification as additional data becomes available.

Organizational consequences of staff turnover in outpatient substance abuse treatment programs.

PubMed

Knight, Danica K; Becan, Jennifer E; Flynn, Patrick M

2012-03-01

The purpose of this study was to examine the impact of staff turnover on perceptions of organizational demands and support among staff who remained employed in substance abuse treatment programs. The sample consisted of 353 clinical staff from 63 outpatient agencies. Two scales from the Survey of Organizational Functioning measured work environment demands (stress and inadequate staffing), and 3 measured supportive work relationships (communication, cohesion, and peer collaboration). Results from a series of multilevel models documented that counselors working in programs that had previously experienced high staff turnover perceived higher demands and lower support within their organization, even after controlling for other potentially burdensome factors such as budget, census, and individual measures of workload. Two individual-level variables, caseload and tenure, were important determinants of work environment demands but were not related to supportive work relationships. Findings suggest that staff turnover increases workplace demands, decreases perceptions of support, and underscores the need to reduce stress and minimize subsequent turnover among clinical staff. Copyright © 2012 Elsevier Inc. All rights reserved.

History of concussion impacts electrophysiological correlates of working memory.

PubMed

Hudac, Caitlin M; Cortesa, Cathryn S; Ledwidge, Patrick S; Molfese, Dennis L

2017-10-10

Sports-related concussions occur in approximately 21% of college athletes with implications for long-term cognitive impairments in working memory. Working memory involves the capacity to maintain short-term information and integrate with higher-order cognitive processing for planning and behavior execution, critical skills for optimal cognitive and athletic performance. This study quantified working memory impairments in 36 American football college athletes (18-23years old) using event-related potentials (ERPs). Despite performing similarly in a standard 2-back working memory task, athletes with history of concussion exhibited larger P1 and P3 amplitudes compared to Controls. Concussion History group latencies were slower for the P1 and faster for the N2. Source estimation analyses indicated that previously concussed athletes engaged different brain regions compared to athletes with no concussion history. These findings suggest that ERPs may be a sensitive and objective measure to detect long-term cognitive consequences of concussion. Copyright © 2017 Elsevier B.V. All rights reserved.

An Australian study of possible selves perceived by undergraduate engineering students

NASA Astrophysics Data System (ADS)

Bennett, Dawn; Male, Sally A.

2017-11-01

In this study, we worked with second-year engineering students at an Australian university to examine previously identified threshold concepts within the theoretical framework of Possible Selves. Using workshops as the context for intensive work with students, students were encouraged to consider their future lives and work, including their engineering fears, expectations, and aspirations. The findings revealed many students to have a poor understanding of the realities of engineering work. Moreover, perceived gaps between self-efficacy and the requirements of engineering work appeared to be motivating if students deemed it possible to reduce the gap, but demotivating if they identified a characteristic over which there was perceived to be no control. The study suggests that these engineering students needed more opportunities to explore both the roles of engineers and their own possible selves. Overall, the findings indicate that higher education students may need encouragement and support to explore potential future roles, and they strengthen calls for further research in this area.

Organizational Consequences of Staff Turnover in Outpatient Substance Abuse Treatment Programs

PubMed Central

Knight, Danica K.; Edwards, Jennifer R.; Flynn, Patrick M.

2014-01-01

The purpose of this study was to examine the impact of staff turnover on perceptions of organizational demands and support among staff who remained employed in substance abuse treatment programs. The sample consisted of 353 clinical staff from 63 outpatient agencies. Two scales from the Survey of Organizational Functioning (SOF) measured work-environment demands (Stress, Inadequate Staffing), and three measured supportive work relationships (Communication, Cohesion, Peer Collaboration). Results from a series of multilevel models documented that counselors working in programs that had previously experienced high staff turnover perceived higher demands and lower support within their organization, even after controlling for other potentially burdensome factors such as budget, census, and individual measures of workload. Two individual-level variables, caseload and tenure, were important determinants of work-environment demands, but were not related to supportive work relationships. Findings suggest that staff turnover increases workplace demands and decreases perceptions of support, and underscore the need to reduce stress and minimize subsequent turnover among clinical staff. PMID:22154028

Indirect decentralized repetitive control

NASA Technical Reports Server (NTRS)

Lee, Soo Cheol; Longman, Richard W.

1993-01-01

Learning control refers to controllers that learn to improve their performance at executing a given task, based on experience performing this specific task. In a previous work, the authors presented a theory of indirect decentralized learning control based on use of indirect adaptive control concepts employing simultaneous identification and control. This paper extends these results to apply to the indirect repetitive control problem in which a periodic (i.e., repetitive) command is given to a control system. Decentralized indirect repetitive control algorithms are presented that have guaranteed convergence to zero tracking error under very general conditions. The original motivation of the repetitive control and learning control fields was learning in robots doing repetitive tasks such as on an assembly line. This paper starts with decentralized discrete time systems, and progresses to the robot application, modeling the robot as a time varying linear system in the neighborhood of the desired trajectory. Decentralized repetitive control is natural for this application because the feedback control for link rotations is normally implemented in a decentralized manner, treating each link as if it is independent of the other links.

Neural systems for preparatory control of imitation.

PubMed

Cross, Katy A; Iacoboni, Marco

2014-01-01

Humans have an automatic tendency to imitate others. Previous studies on how we control these tendencies have focused on reactive mechanisms, where inhibition of imitation is implemented after seeing an action. This work suggests that reactive control of imitation draws on at least partially specialized mechanisms. Here, we examine preparatory imitation control, where advance information allows control processes to be employed before an action is observed. Drawing on dual route models from the spatial compatibility literature, we compare control processes using biological and non-biological stimuli to determine whether preparatory imitation control recruits specialized neural systems that are similar to those observed in reactive imitation control. Results indicate that preparatory control involves anterior prefrontal, dorsolateral prefrontal, posterior parietal and early visual cortices regardless of whether automatic responses are evoked by biological (imitative) or non-biological stimuli. These results indicate both that preparatory control of imitation uses general mechanisms, and that preparatory control of imitation draws on different neural systems from reactive imitation control. Based on the regions involved, we hypothesize that preparatory control is implemented through top-down attentional biasing of visual processing.

Cortex Inspired Model for Inverse Kinematics Computation for a Humanoid Robotic Finger

PubMed Central

Gentili, Rodolphe J.; Oh, Hyuk; Molina, Javier; Reggia, James A.; Contreras-Vidal, José L.

2013-01-01

In order to approach human hand performance levels, artificial anthropomorphic hands/fingers have increasingly incorporated human biomechanical features. However, the performance of finger reaching movements to visual targets involving the complex kinematics of multi-jointed, anthropomorphic actuators is a difficult problem. This is because the relationship between sensory and motor coordinates is highly nonlinear, and also often includes mechanical coupling of the two last joints. Recently, we developed a cortical model that learns the inverse kinematics of a simulated anthropomorphic finger. Here, we expand this previous work by assessing if this cortical model is able to learn the inverse kinematics for an actual anthropomorphic humanoid finger having its two last joints coupled and controlled by pneumatic muscles. The findings revealed that single 3D reaching movements, as well as more complex patterns of motion of the humanoid finger, were accurately and robustly performed by this cortical model while producing kinematics comparable to those of humans. This work contributes to the development of a bioinspired controller providing adaptive, robust and flexible control of dexterous robotic and prosthetic hands. PMID:23366569

A quantum dynamics study of the benzopyran ring opening guided by laser pulses

NASA Astrophysics Data System (ADS)

Saab, Mohamad; Doriol, Loïc Joubert; Lasorne, Benjamin; Guérin, Stéphane; Gatti, Fabien

2014-10-01

The ring-opening photoisomerization of benzopyran, which occurs via a photochemical route involving a conical intersection, has been studied with quantum dynamics calculations using the multi-configuration time-dependent Hartree method (MCTDH). We introduce a mechanistic strategy to control the conversion of benzopyran to merocyanine with laser pulses. We use a six-dimensional model developed in a previous work for the potential energy surfaces (PES) based on an extension of the vibronic-coupling Hamiltonian model (diabatization method by ansatz), which depends on the most active degrees of freedom. The main objective of these quantum dynamics simulations is to provide a set of strategies that could help experimentalists to control the photoreactivity vs. photostability ratio (selectivity). In this work we present: (i) a pump-dump technique used to control the photostability, (ii) a two-step strategy to enhance the reactivity of the system: first, a pure vibrational excitation in the electronic ground state that prepares the system and, second, an ultraviolet excitation that brings the system to the first adiabatic electronic state; (iii) finally the effect of a non-resonant pulse (Stark effect) on the dynamics.

A therapeutic workplace for the long-term treatment of drug addiction and unemployment: eight-year outcomes of a social business intervention.

PubMed

Aklin, Will M; Wong, Conrad J; Hampton, Jacqueline; Svikis, Dace S; Stitzer, Maxine L; Bigelow, George E; Silverman, Kenneth

2014-01-01

This study evaluated the long-term effects of a therapeutic workplace social business on drug abstinence and employment. Pregnant and postpartum women (N = 40) enrolled in methadone treatment were randomly assigned to a therapeutic workplace or usual care control group. Therapeutic workplace participants could work weekdays in training and then as employees of a social business, but were required to provide drug-free urine samples to work and maintain maximum pay. Three-year outcomes were reported previously. This paper reports 4- to 8-year outcomes. During year 4 when the business was open, therapeutic workplace participants provided significantly more cocaine- and opiate-negative urine samples than controls; reported more days employed, higher employment income, and less money spent on drugs. During the 3 years after the business closed, therapeutic workplace participants only reported higher income than controls. A therapeutic workplace social business can maintain long-term abstinence and employment, but additional intervention may be required to sustain effects. Copyright © 2014 Elsevier Inc. All rights reserved.

Working memory capacity and the top-down control of visual search: Exploring the boundaries of "executive attention".

PubMed

Kane, Michael J; Poole, Bradley J; Tuholski, Stephen W; Engle, Randall W

2006-07-01

The executive attention theory of working memory capacity (WMC) proposes that measures of WMC broadly predict higher order cognitive abilities because they tap important and general attention capabilities (R. W. Engle & M. J. Kane, 2004). Previous research demonstrated WMC-related differences in attention tasks that required restraint of habitual responses or constraint of conscious focus. To further specify the executive attention construct, the present experiments sought boundary conditions of the WMC-attention relation. Three experiments correlated individual differences in WMC, as measured by complex span tasks, and executive control of visual search. In feature-absence search, conjunction search, and spatial configuration search, WMC was unrelated to search slopes, although they were large and reliably measured. Even in a search task designed to require the volitional movement of attention (J. M. Wolfe, G. A. Alvarez, & T. S. Horowitz, 2000), WMC was irrelevant to performance. Thus, WMC is not associated with all demanding or controlled attention processes, which poses problems for some general theories of WMC. Copyright 2006 APA, all rights reserved.

The face-specific proportion congruency effect: social stimuli as contextual cues.

PubMed

Jiménez-Moya, Gloria; Rodríguez-Bailón, Rosa; Lupiáñez, Juan

2018-06-18

Previous research shows that larger interference is observed in contexts associated with a high proportion of congruent trials than in those associated with a low proportion of congruent trials. Given that one of the most relevant contexts for human beings is social context, researchers have recently explored the possibility that social stimuli could also work as contextual cues for the allocation of attentional control. In fact, it has been shown that individuals use social categories (i.e., men and women) as cues to allocate attentional control. In this work, we go further by showing that individual faces (instead of the social categories they belong to) associated with a high proportion of congruent trials can also lead to larger interference effects compared to individual faces predicting a relatively low proportion of congruent trials. Furthermore, we show that faces associated with a high proportion of congruent trials are more positively evaluated than faces associated with a high proportion of incongruent trials. These results demonstrate that unique human faces are potential contextual cues than can be employed to apply cognitive control when performing an automatic task.

Chronic Stress Impairs Prefrontal Cortex-Dependent Response Inhibition and Spatial Working Memory

PubMed Central

Mika, Agnieszka; Mazur, Gabriel J.; Hoffman, Ann N.; Talboom, Joshua S.; Bimonte-Nelson, Heather A.; Sanabria, Federico; Conrad, Cheryl D.

2012-01-01

Chronic stress leads to neurochemical and structural alterations in the prefrontal cortex (PFC) that correspond to deficits in PFC-mediated behaviors. The present study examined the effects of chronic restraint stress on response inhibition (using a response-withholding task, fixed-minimum interval schedule of reinforcement, or FMI), and working memory (using a radial arm water maze, RAWM). Adult male Sprague Dawley rats were first trained on the RAWM and subsequently trained on FMI. Following acquisition of FMI, rats were assigned to a restraint stress (6h/d/28d in wire mesh restrainers) or control condition. Immediately after chronic stress, rats were tested on FMI and subsequently on RAWM. FMI results suggest that chronic stress reduces response inhibition capacity and motivation to initiate the task on selective conditions when food reward was not obtained on the preceding trial. RAWM results suggest that chronic stress produces transient deficits in working memory without altering previously consolidated reference memory. Behavioral measures from FMI failed to correlate with metrics from RAWM except for one in which changes in FMI timing precision negatively correlated with changes in RAWM working memory errors for the controls, a finding that was not observed following chronic stress. Fisher’s r to z transformation revealed no significant differences between control and stress with correlation coefficients. These findings are the first to show that chronic stress impairs both response inhibition and working memory, two behaviors that have never been direct compared within the same animals following chronic stress, using FMI, an appetitive task, and RAWM, a non-appetitive task. PMID:22905921

Walking on uneven terrain with a powered ankle prosthesis: A preliminary assessment.

PubMed

Shultz, Amanda H; Lawson, Brian E; Goldfarb, Michael

2015-01-01

A successful walking gait with a powered prosthesis depends heavily on proper timing of power delivery, or push-off. This paper describes a control approach which provides improved walking on uneven terrain relative to previous work intended for use on even (level) terrain. This approach is motivated by an initial healthy subject study which demonstrated less variation in sagittal plane shank angle than sagittal plane ankle angle when walking on uneven terrain relative to even terrain. The latter therefore replaces the former as the control signal used to initiate push-off in the powered prosthesis described herein. The authors demonstrate improvement in consistency for several gait characteristics, relative to healthy, as well as controller characteristics with the new control approach, including a 50% improvement in the consistency of the percentage of stride at which push-off is initiated.

Fuzzy Logic Based Control for Autonomous Mobile Robot Navigation

PubMed Central

Masmoudi, Mohamed Slim; Masmoudi, Mohamed

2016-01-01

This paper describes the design and the implementation of a trajectory tracking controller using fuzzy logic for mobile robot to navigate in indoor environments. Most of the previous works used two independent controllers for navigation and avoiding obstacles. The main contribution of the paper can be summarized in the fact that we use only one fuzzy controller for navigation and obstacle avoidance. The used mobile robot is equipped with DC motor, nine infrared range (IR) sensors to measure the distance to obstacles, and two optical encoders to provide the actual position and speeds. To evaluate the performances of the intelligent navigation algorithms, different trajectories are used and simulated using MATLAB software and SIMIAM navigation platform. Simulation results show the performances of the intelligent navigation algorithms in terms of simulation times and travelled path. PMID:27688748

Age-related changes in strategic variations during arithmetic problem solving: The role of executive control.

PubMed

Hinault, T; Lemaire, P

2016-01-01

In this review, we provide an overview of how age-related changes in executive control influence aging effects in arithmetic processing. More specifically, we consider the role of executive control in strategic variations with age during arithmetic problem solving. Previous studies found that age-related differences in arithmetic performance are associated with strategic variations. That is, when they accomplish arithmetic problem-solving tasks, older adults use fewer strategies than young adults, use strategies in different proportions, and select and execute strategies less efficiently. Here, we review recent evidence, suggesting that age-related changes in inhibition, cognitive flexibility, and working memory processes underlie age-related changes in strategic variations during arithmetic problem solving. We discuss both behavioral and neural mechanisms underlying age-related changes in these executive control processes. © 2016 Elsevier B.V. All rights reserved.

Stability Result For Dynamic Inversion Devised to Control Large Flexible Aircraft

NASA Technical Reports Server (NTRS)

Gregory, Irene M.

2001-01-01

High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper is an initial attempt to establish global stability results for dynamic inversion methodology as applied to a large, flexible aircraft. This work builds on a previous result for rigid fighter aircraft and adds a new level of complexity that is the flexible aircraft dynamics, which cannot be ignored even in the most basic flight control. The results arise from observations of the control laws designed for a new generation of the High-Speed Civil Transport aircraft.

Observing quantum control of up-conversion luminescence in Dy3+ ion doped glass from weak to intermediate shaped femtosecond laser fields

NASA Astrophysics Data System (ADS)

Liu, Pei; Cheng, Wenjing; Yao, Yunhua; Xu, Cheng; Zheng, Ye; Deng, Lianzhong; Jia, Tianqing; Qiu, Jianrong; Sun, Zhenrong; Zhang, Shian

2017-11-01

Controlling the up-conversion luminescence of rare-earth ions in real-time, in a dynamical and reversible manner, is very important for their application in laser sources, fiber-optic communications, light-emitting diodes, color displays and biological systems. In previous studies, the up-conversion luminescence control mainly focused on the weak femtosecond laser field. Here, we further extend this control behavior from weak to intermediate femtosecond laser fields. In this work, we experimentally and theoretically demonstrate that the up-conversion luminescence in Dy3+ ion doped glass can be artificially controlled by a π phase step modulation, but the up-conversion luminescence control behavior will be affected by the femtosecond laser intensity, and the up-conversion luminescence is suppressed by lower laser intensity while enhanced by higher laser intensity. We establish a new theoretical model (i.e. the fourth-order perturbation theory) to explain the physical control mechanism by considering the two- and four-photon absorption processes, and the theoretical results show that the relative weight of four-photon absorption in the whole excitation process will increase with the increase in laser intensity, and the interference between two- and four-photon absorptions results in up-conversion luminescence control modulation under different laser intensities. These theoretical and experimental works can provide a new method to control and understand up-conversion luminescence in rare-earth ions, and also may open a new opportunity to the related application areas of rare-earth ions.

Encoding and Decoding of Multi-Channel ICMS in Macaque Somatosensory Cortex.

PubMed

Dadarlat, Maria C; Sabes, Philip N

2016-01-01

Naturalistic control of brain-machine interfaces will require artificial proprioception, potentially delivered via intracortical microstimulation (ICMS). We have previously shown that multi-channel ICMS can guide a monkey reaching to unseen targets in a planar workspace. Here, we expand on that work, asking how ICMS is decoded into target angle and distance by analyzing the performance of a monkey when ICMS feedback was degraded. From the resulting pattern of errors, we found that the animal's estimate of target direction was consistent with a weighted circular-mean strategy-close to the optimal decoding strategy given the ICMS encoding. These results support our previous finding that animals can learn to use this artificial sensory feedback in an efficient and naturalistic manner.