bluuebunny/crossref_metadata_2025 huggingface dataset:
An outbreak of Sarcocystis calchasi encephalitis in multiple psittacine species within an enclosed zoological aviary
Authors: Rimoldi Guillermo , Speer Brian , Wellehan James F. X. , Bradway Daniel S. , Wright Lewis , Reavill Drury , Barr Bradd C. , Childress April , Shivaprasad H. L. , Chin Richard. P.
Published: October 2013

A total of 5 psittacine birds in an enclosed zoological exhibit, including 2 princess parrots and 3 cockatoos of 2 different species, developed severe central nervous system clinical signs over a 2–3-month period and died or were euthanized. Histologically, all birds had a lymphoplasmacytic and histiocytic encephalitis with intralesional protozoa consistent with a Sarcocystis species in addition to intramuscular tissue sarcocysts. By immunohistochemical staining, merozoites in brain and tissue cysts in muscle did not react with polyclonal antisera against Sarcocystis falcatula, Sarcocystis neurona, Toxoplasma gondii, and Neospora caninum, or with a monoclonal antibody to S. neurona. Transmission electron microscopy on sarcocyst tissue cyst walls from 2 birds was morphologically consistent with Sarcocystis calchasi. Polymerase chain reaction (PCR) amplification and sequencing of partial 18S ribosomal RNA from muscle tissue cysts and brain schizonts from 3 birds was consistent with a clade containing S. calchasi and Sarcocystis columbae but could not distinguish these closely related Sarcocystis species. However, PCR amplification and sequencing of the internal transcribed spacer 1 RNA segment in the brain from 2 birds and muscle from 2 birds specifically identified the isolates as S. calchasi. The current report documents that multiple psittacine species are susceptible intermediate hosts of S. calchasi, and that infection can cause encephalitis resulting in significant morbidity and mortality in psittacine aviaries.
Fatal outbreak of systemic pasteurellosis in a wild boar (Sus scrofa) population from southwest Spain
Authors: Risco David , Fernández-Llario Pedro , Cuesta Jesús M. , García-Jiménez Waldo L. , Gil María , Gonçalves Pilar , Martínez Remigio , Gómez Luis , García Alfredo , Rey Joaquín , Hermoso de Mendoza Miguel , Hermoso de Mendoza Javier
Published: October 2013

Pasteurella multocida is a common pathogen of swine that causes specific diseases with great economic impact. However, the importance of this pathogen in wild boar is still unknown. In the current work, an outbreak of systemic pasteurellosis in wild boar with a high mortality rate is described. A total of 23 wild boar of all ages were found dead over a 5-day period on a game estate in southwest Spain (11.11% mortality). Three animals were necropsied and showed subcutaneous edema, a generalized congestion, and fibrin deposits in the peritoneal cavity. Hemorrhages, general congestion, and intravascular thrombosis were microscopically observed. Pasteurella multocida type B was isolated from all of the studied organs. Outbreaks of systemic pasteurellosis have been described in domestic pigs from Asia and Australia, but not to date in Europe. This outbreak suggests that systemic pasteurellosis affecting wild boar populations may be an important cause of mortality.
Connecting relatives in virtual worlds: The kinship networks
Authors: Carchiolo Vincenza , Longheu Alessandro , Di Martino Vincenzo , Malgeri Michele , Mangioni Giuseppe
Published: October 2013

The effect of the Internet on everyday life is huge, especially for what concerns the number and quality of our social relationships, including friendships and kinship. Fortunately, the complex network theory recently made it feasible to analyze real and large social networks, making it possible to understand their behavior and dynamics, including why and how social connections are established and what actually imply in the real world, the attitudes toward collaboration, and many other issues. In this article, a proposal for building and enhancing personal kinship networks is presented; this Kinship Search System allows each user to craft his or her genealogical tree by exploring and searching existing acquaintances and friendship relations that connect relatives among themselves and with other people.
A Phonologically Based Intervention for School-Age Children With Language Impairment
Authors: Ritter Michaela J. , Park Jungjun , Saxon Terrill F. , Colson Karen A.
Published: October 2013

This study was conducted utilizing a quasi-experimental pre- and postgroup design to examine the effects of a phonologically based intervention aimed to improve phonological awareness (PA) and reading abilities in school-age children with language impairment (LI) in Grades 1 through 3. The intervention included instruction in PA and sound-symbol correspondence. Sixty-four school-age children with LI (Grades 1-3) were assigned to either an experimental ( n = 34) or a control group ( n = 30). Eleven kindergarten-age children with LI were then included as a comparison grade group to investigate whether the magnitude of treatment effect changed across grade level in the experimental group (K-3). Participants in the experimental group (Grades 1-3) made significantly greater gains in PA and reading (e.g., decoding and text comprehension) than the control group. Similar gains were observed across the varying grade levels (K-3). These results suggest that, despite being at risk of reading failure, school-age children with LI in Grades 1 through 3 have the potential to make accelerated gains in their reading development and in the PA skills that are essential to successful literacy acquisition.
Early Mover or Late Mover Advantage for Hotels?
Authors: Lee Seul Ki , Jang SooCheong (Shawn)
Published: October 2013

Theories on early and late mover advantages predicate that competitive operating advantages can occur with respect to the relative timing of market entry. Suspecting that “early mover” hotels can preempt desirable micro-locations for hotel operations, the current study tests for early mover advantage created by locations not fully imitable. Estimation of spatial econometric model reveals evidence of an early mover advantage. We also find that the effect of depreciation of older hotels may serve as a competitive advantage for new entrants with new facilities, although there was no considerable benefit for late movers. Furthermore, through additional tests we find the early mover advantage consistently significant for both chain and independent hotels. Implications and suggestions for future research are discussed.
Squeeze film lubrication of coupled stress electrically conducting inertial fluids in wide parallel rectangular conjunctions subjected to a magnetic field
Authors: Daliri M , Jalali-Vahid D , Rahnejat H
Published: October 2013

The paper presents analytical solution of squeeze film characteristics in wide parallel rectangular conjunctions with incompressible electrically conducting couple stress fluids subjected to a magnetic field. Analytical expressions are obtained by combined solution of modified Reynolds equation and Stokes micro-continuum for couple stress fluids with averaged inertia. Various cases of magneto-hydrodynamic, conducting and non-conducting fluid characteristics with and without convective inertial contributions are investigated. It is shown that, in general, couple stress fluids enhance the load carrying capacity of the contact and inhibit the incidence of thin films which can result in direct contact of surfaces. Convective inertia also significantly improves the load carrying capacity. However, with impulsive loading the response time of couple stress fluids deteriorates relative to Newtonian lubricants on account of their increased viscosity. An important conclusion of the study is that magneto-hydrodynamic couple stress fluids are best suited to applications with high relatively steady load applications.
How children with experiences of intimate partner violence towards the mother understand and relate to their father
Authors: Staf Anna Georgsson , Almqvist Kjerstin
Published: October 2013

The aim of this study was to describe how, in the aftermath of intimate partner violence against the mother, children understand and relate to their father. Face-to-face interviews with four girls and four boys, aged between eight and twelve, were analysed using an interpretative phenomenological approach. All of the children had been exposed to the father’s violence towards the mother. Two super ordinate themes were identified in the analysis: the disjunctive image of the father and being entangled in a conflict. The children’s understanding of the father and their relationship with him was built on different versions of the father and his actions; those experienced by the child and those recounted to them. The situational context surrounding the described experience pervaded the image of the father. An ambiguity appeared to exist in the sense of different versions of the father and children described different emotions that could both hinder and elicit other feelings connected to the father. Children also conveyed the sense of being trapped or entangled in a conflict where their own needs and desires could be deemed as unsafe to express, and that they felt responsibility for dealing with the father’s influence.
The Role of HRD in Stimulating, Supporting, and Sustaining Creativity and Innovation
Authors: Loewenberger Pauline
Published: October 2013

Challenging environments call for creativity and innovation, dynamic processes that depend upon the interaction of the individual with the social and organizational environment, placing people issues in the foreground. Extant literature suggests a number of problems. First, the frequent confusion that surrounds what this actually means in practice. Second, regardless of the potential for all creative idea generation is not common for most individuals. Finally, successful exploitation of new ideas must overcome social and organizational barriers in the work environment. All are problems that HRD is well placed to address. Integration with creativity and innovation research is essential for HRD to effectively stimulate capability and commitment across multiple levels of the organizational system. An integrated review of literature sources supports the suggestion that integration remains in its infancy. This article proposes a synthesis of extant literature in the field of creativity and innovation with HRD leading to an exploration of practical implications.
Postures and Motions Library Development for Verification of Ground Crew Human Factors Requirements
Authors: Stambolian Damon , Henderson Gena , Jackson Mariea Dunn , Dischinger Charles
Published: October 2013

Spacecraft and launch vehicle ground processing activities require a variety of unique human activities. These activities are being documented in a primitive motion capture library. The library will be used by human factors engineering analysts to infuse real to life human activities into the CAD models to verify ground systems human factors requirements. As the primitive models are being developed for the library, the project has selected several current human factors issues to be addressed for the Space Launch System (SLS) and Orion launch systems. This paper explains how the motion capture of unique ground systems activities is being used to verify the human factors engineering requirements for ground systems used to process the SLS and Orion vehicles, and how the primitive models will be applied to future spacecraft and launch vehicle processing.
The Impact of Adaptive Automation Invoking Thresholds on Cognitive Workload and Situational Awareness
Authors: Rusnock Christina F. , Geiger Christopher D.
Published: October 2013

Adaptive automation is expected to reduce workload and increase situational awareness; however, these measures can either converge or diverge. Thus, whether the adaptive system improves both, or just one of these, depends on the relationship between these measures for a particular system. By varying the invoking threshold, system designers impact the levels of these measures. This study uses discrete event simulation to characterize the relationship between workload and situational awareness in an adaptive system and finds that the relationship between workload and situational awareness is dependent on the invoking threshold and the level of task load.
A Shocking lack of Difference
Authors: Falcone Brian , McKendrick Ryan , Parasuraman Raja
Published: October 2013

Enhancing working memory through brain stimulation can contribute to the neuroergonomic goal of improving cognitive functioning at work and in everyday life. Imaging and lesion studies suggest that verbal and spatial working memory processing may be controlled in separate brain regions. Specifically, verbal working memory has been associated with the left dorsolateral prefrontal cortex (DLPFC) and spatial working memory with the right DLPFC. The current study used noninvasive brain stimulation to further examine this cortical dissociation between verbal and spatial working memory. We administered 2mA or 0.1mA of anodal transcranial direct current stimulation (tDCS) to the left and right DLPFC while participants performed verbal and spatial working memory tasks. Contrary to our initial hypotheses, stimulation of the left DLPFC improved spatial working memory but not verbal working memory. Furthermore, stimulation of right DLPFC did not affect verbal or spatial working memory.
What does it mean for an interruption to be relevant? An investigation of relevance as a memory effect
Authors: Gould Sandy J. J. , Brumby Duncan P. , Cox Anna L.
Published: October 2013

Interruptions cause slower, more error prone performance. Research suggests these disruptive effects are mitigated when interruptions are relevant to the task at hand. However, previous work has usually defined relevance as the degree of similarity between the content of interruptions and tasks. Using a lab-based experiment, we investigated the extent to which memory effects should be considered when assessing the relevance of an interruption. Participants performed a routine data-entry task during which they were interrupted. We found that when participants were interrupted between subtasks, reinforcement and interference effects meant that relevance had a significant effect on interruption disruptiveness. However, this effect was not observed when participants were interrupted within subtasks. These results suggest that interruption relevance is contingent on the contents of working memory during an interruption and that interruption management systems could be improved by modelling potential interfering and reinforcing effects of incoming interruptions.
The Relationship Between Levels of User Experience with a Product and Perceived System Usability
Authors: Kortum Philip , Johnson Megan
Published: October 2013

The System Usability Scale (SUS) is a ten-point assessment tool developed as a reliable low-cost subjective usability scale that can be applied to systems in any number of contexts. Research has demonstrated higher usability ratings from users who claim greater experience with an interface than from those who rate themselves as having less experience. This paper describes research to extend this work by experimentally controlling the experience levels of the users over the course of the study, rather than relying on users’ self-report. Two studies were conducted. In the first, Microsoft Publisher was used over three one hour sessions, with usability being measured with the SUS at the completion of each session. In the second study, MathWorks MATLAB was used over the course of 14 weeks, and SUS usability was measured near the beginning, the middle and end of this time frame. Results from the MS publisher study showed an increase in reported usability with increased experience consistent with the literature, but the data from the MATLAB study did not show this trend. Reasons for this discrepancy are discussed, as are future research directions that could shed further light on these unexpected findings.
Agent-Based Model of a Cyber Security Defense Analyst Team
Authors: Rajivan Prashanth , Janssen Marco A. , Cooke Nancy J
Published: October 2013

Cyber security defense is often performed by a group of people called cyber defense analysts and yet team work and collaboration in cyber defense is almost non-existent. This study, using an agent-based model of the cyber defense analyst’s task and interactions, explored the effects of different collaboration strategies and team sizes on performance measures such as number of intrusion alerts accurately processed by the analysts and rewards they accrue from accurately processing the alerts. This study also explored the feasibility of using agent-based modeling methodologies for studying team processes in the cyber defense context. The model revealed that specific collaboration strategies lead to better performance and that large teams are detrimental to performance.
Designing for Interpersonal Trust – The Power of Trust Tokens
Authors: Morita Plinio P. , Burns Catherine M.
Published: October 2013

Computer mediated communication systems (CMCSs) are increasingly being used to support activities of virtual teams, improving information exchange and capacity of these teams. However, the technology that enables these teams to benefit from effective and timely information exchange suffers from constraints of media richness, limiting the amount of social information that can be transmitted. This missing information can affect the formation of trust between members of these teams. In this paper, we conducted an ethnographic study to identify behaviors that facilitate the development of trust within face-to-face teams as an opportunity to design interface design objects with similar effects. A key observation was trust tokening, where trust is conveyed through social referents. Trust tokening has the potential to be adapted for use in computer support systems where establishing interpersonal trust is just as important as face-to-face collaborations.
Human Redundancy as Safety Measure in Automation Monitoring
Authors: Manzey Dietrich , Boehme Karl , Schoebel Markus
Published: October 2013

The present study addresses effects of human redundancy on automation monitoring performance. Fourty-six participants performed a multi-task, consisting of three sub-tasks which simulate basic demands of operators in a chemical plant. One of the tasks involved the monitoring of an automated process. Participants were randomly assigned to three groups: (1) “Non-Redundant”: participants worked on all tasks alone. (2) “Redundant”: participants were informed that a second crewmate would work in parallel on the monitoring task. (3) “Redundant-Feedback”: like the “redundant” condition with the additional information that crewmembers’ individual monitoring performance would be tracked and fed back. Results provide evidence of social loafing effects in monitoring performance. Participants in the “redundant” condition cross-checked the automation significantly less than participants in the other groups. Moreover they were more prone to miss automation failures which occurred surprisingly. The anticipation that individual performance will be tracked and fed back after the task in the “redundant-feedback” group reduced this effect. The results suggest that human redundancy does not necessarily constitute an effective measure for enhancing reliability of automation monitoring and that expected positive effects can at least partially be off-set by a sort of social-loafing effect.
Employing User-Created Pictures to Enhance the Recall of System-Generated Mnemonic Phrases and the Security of Passwords
Authors: Fraune Marlena R. , Juang Kevin A. , Greenstein Joel S. , Madathil Kapil Chalil , Koikkara Reshmi
Published: October 2013

User-created passwords are typically higher in usability but lower in security than computer-generated passwords. This study evaluates the usability and security of a password scheme in which users are assigned computer-generated random passwords and corresponding computer-generated mnemonic phrases. Users created images that matched the phrases to cue password recall at the time of login. Different picture creation methods (drawing, online images, and a combination of both) and a control condition (no picture) were used to examine the effects of picture creation method on password memorability. Login success was measured the day of account creation and after approximately one week. To measure security during the second session, participants were also asked to simulate attackers by attempting to derive others’ passwords from viewing their images. Analysis revealed that pictures enhanced password memorability but picture creation method had no effect on password memorability. There were no significant differences in security across the four conditions.
Usability, Engagement, and Satisfaction of Two e-Textbook Applications
Authors: Jardina Jo R. , Chaparro Barbara S.
Published: October 2013

Many schools and universities are starting to offer e-Textbooks in place of traditional paper textbooks. While this option is typically more cost-effective, limited research has been done to demonstrate whether e-Textbooks are a viable alternative in the classroom. This study investigated the satisfaction, perceived workload, engagement, and comprehension of two separate e-Textbook applications, Kindle and Inkling, for tasks involved in studying for a college-level quiz. The ability to use the e-Textbook for studying, to make notes and bookmarks, and to navigate throughout a chapter was examined. Participants using each application demonstrated an improvement in their comprehension scores. Despite this, participants discovered several issues which impacted overall ease of use on both applications. For instance, the table of contents was problematic on the Kindle and locating a specific page was problematic on Inkling. Details on these findings and design implications are discussed.
Benefits of a Proactive Office Ergonomics Program
Authors: Hedge Alan
Published: October 2013

Ergonomics surveys were conducted in a software company with a proactive ergonomics program before and after moving to a new headquarters building in which workstations were equipped with ergonomic products. Sixty-seven workers voluntarily completed surveys of their workstations, workplace environment, work-related health and well-being (job satisfaction, happiness). Post-move results showed that after moving to the ergonomic workstations the prevalence of musculoskeletal discomfort was reduced, overall satisfaction with workstations improved, and employees were happier and more satisfied with their job.
People, Places and Potentialities in Design – Research Tools to Examine Challenges in Behind-the-Counter Work
Authors: Mullick Abir , Kar Gourab
Published: October 2013

This paper describes the use of research tools that examined challenges of American older adults involved in behind-the-counter (BhC) work. The study investigated human-environment interactions in BhC Workspaces and learned about environmental fit or how the capacity of a person combines with environmental demands to determine performance in a given situation. Three sequential research tools trace study, marginal participant observation and user interviews, were employed to evaluate four types of BhC workspaces—library circulation counter, hotel check-in counter, airport check-in counter and office reception counter. The interdependent, sequential cycle of adoption of these tools offered important means to learn about worker needs in BhC work, identify environmental problems and develop inclusive design solutions that offer safety, prevent injury, and prolong work-life. The multi-pronged approach helped develop information about BhC work and confirm interdependent methods.
Human Differences in Navigational Approaches during Tele-Robotic Search
Authors: Stone Richard T. , Dorneich Michael , Gilbert Stephen , McLaurin Elease
Published: October 2013

This study investigated the navigational approaches used by humans when operating a simple tele-robot in a simulated search and rescue operation. Tele-robots are being increasingly used in safety-critical operations. During tele-operation, the situational awareness of tele-robot operators needs to be supported. Navigation depends on psychological skills of perception and cognition, and can utlize different problem solving strategies. However, there is limited knowledge of how operators develop situational awareness while navigating tele-robots. The study was conducted to understand if there were distinctive, identifiable strategies in the way operators navigated. When participants manually tele-operated a robot in a remote physical environment, two distinct navigation strategies were found (labeled driver method and searcher method). The result of this work can be used to inform the design of human-centric tele-robot navigational algorithms that can support a variety of human navigation strategies.
Strategies for Training Technical and Non-technical Surgical Skills
Authors: Miller A. , Sun T. , Pyatka N. , Brewer J. , Ganapathy S. , Weyhrauch P. , Niehaus J. , Cao C.G.L.
Published: October 2013

Even though laparoscopic surgery has become the preferred technique for many surgeons, the methods of training are not standardized. Most simulators and training programs focus on training technical skills, neglecting very important non-technical skills. This study examined the benefits of different strategies of training both technical and non-technical skills amongst different experience levels. Twenty-seven subjects participated in the study (9 novices, 9 intermediate experience level subjects, and 9 advanced subjects). They were divided into 3 groups: technical, non-technical, and combined. Subjects practiced a purely technical, purely non-technical, and a combined technical and non-technical simulated surgical task. Data from pre-test and post-test scores as well as the last training block of combined training were analyzed for time to completion, number of technical errors and number of non-technical errors. Results suggest that there may be a benefit to training non-technical skills alone first, or in conjunction with technical surgical skills in novices during the beginning phases of learning.
Evaluating the Redesign of an ICU Bedside Emergency Equipment Drawer
Authors: Harris Bonnie , Ford Nicholas , Grundgeiger Tobias , Venkatesh Bala , Sanderson Penelope
Published: October 2013

Patient safety can be improved by redesigning how medication and bedside equipment is stored in the intensive care unit (ICU). Grundgeiger (2011) noted that an ICU emergency bedside drawer often was not fully stocked. He used human factors principles to design an illustrated and divided drawer that significantly improved drawer restocking compliance and is still in use in the ICU. In two studies we set out to clarify exactly why Grundgeiger’s redesign succeeded. In Experiment 1 we tested the redesigned vs. old drawer design using stationery contents and psychology student participants. In Experiment 2 we used the tests developed in Experiment 1 to compare ICU nurses’ performance with the redesigned vs. old drawer design. Both experiments indicate that the divided and illustrated drawer leads to faster restocking times and overwhelmingly positive user acceptance.
Medical Decision Making Performance in Dual-task Scenarios
Authors: Cao Shi , Liu Yili
Published: October 2013

Physicians often perform multiple tasks concurrently, such as diagnosing a disease while talking with another physician about other patients. However, little experimental evidence is available to determine whether a concurrent task affects the quality and timely performance of diagnostic decisions. In this study, we employed a representative medical diagnostic task to examine the effects of concurrent tasks on diagnostic decision making, in which potential confounding factors are controlled to allow the quantification of diagnostic performance and strategies. The results showed that diagnostic performance was negatively affected by a complex concurrent memorization task that required participants to listen to verbal updates and remember information about other patients while performing the diagnostic task. In contrast, a simple concurrent sound monitoring task did not affect diagnostic performance. Participants used the same diagnostic strategies in the single- and dual-task conditions. These findings provide new insights into the cognitive mechanisms underlying medical diagnostic decision and physician multitasking. Implications for the improvement of healthcare quality are discussed.
Using Meta-Analyses Results and Data Gathering to Support Human Performance Model Development
Authors: Sebok Angelia , Wickens Christopher , Sargent Robert
Published: October 2013

Human performance modeling provides a tool to facilitate the development of well-designed systems that support their users. However, models need to be based on and compared against empirical human-in-the-loop data to ensure that the human performance predictions are correct. This paper describes an approach to gathering already-existing empirical data to support the development of a model of astronaut performance in long-duration space missions.
First Steps Toward Modeling ADHD Under a Dual-Task Paradigm Using a Markovian Framework for Diagnosis
Authors: Lu Sara A.
Published: October 2013

Attention-Deficit Hyperactivity Disorder (ADHD) is a common cognitive disorder afflicting many children and adults. Since most ADHD diagnostic procedures are based on subjective assessments, the goal of this study was to develop an objective assessment that takes into account performance differences between ADHD and non-ADHD individuals under a dual-task paradigm. Specifically, a model using a Markovian framework was used to determine the probability people with and without ADHD would switch between two tasks. Two studies were used, one to develop the model and one to validate the model. The values from the Ewen et al. (2012) study were used to determine the values of interest: the percentage of time spent on the each task, the probabilities remaining on each task, and the probabilities of switching between tasks. The developed multiplier value equations, which established the predicted values, were validated using the values from the Cepeda et al. (2000) study. The differences between the predicted values were all within 15% of the actual values. Overall, the study provides the initial stepping stone toward developing an objective ADHD diagnostic tool based on dual-task performance.
Complex Systems And Human Performance Modeling
Authors: Warwick Walter , Marusich Laura , Buchler Norbou
Published: October 2013

The development of a human performance model is an exercise in complexity. Despite this, techniques that are commonplace in the study of complex dynamical systems have yet to find their way into human performance modeler’s toolbox. In this paper, we describe our efforts to develop new generative and analytical methods within a task network modeling environment. Specifically, we present task network modeling techniques for generating inter-event times series typical of a complex system. We focus on communication patterns. In addition, we describe the associated analytical techniques needed to verify the time series. Again, while these analytical techniques will be familiar to the complexity scientist, they have significant and largely unrecognized methodological implications for the human performance modeler.
Towards Biomechanical Digital Human Modeling of Elderly People for Simulations in Virtual Product Development
Authors: Miehling Jörg , Geißler Bastian , Wartzack Sandro
Published: October 2013

This contribution illustrates a methodology to customize biomechanical digital human models to resemble people of different age and ability groups for the use in simulations to support user-centered design. Especially the conception of man models of elderly people holds potential for analyzing and optimizing products to yield more universal designs, due to the high heterogeneity of needs, wants and capabilities in this specific age group. The present approach considers age-related performance restrictions, but is also extendable to disease-related limitations. The conception process itself includes the scaling of anthropometry, muscle forces, range of motion as well as motion speed based on data from literature or manual measurements. The parameters are either selected by percentiles or the specific values itself.
Carpal Tunnel Syndrome Among Occupational Workers in India
Authors: Singh Dheeraj , Singh Greesh Kumar , Srivastava Sanjay
Published: October 2013

Carpal tunnel syndrome (CTS) is one of the most widely observed peripheral neuropathies among industrial workers. Occupations involving use of wrist for long working hours are associated with increased occurrence of CTS. Exposure to machine vibrations, force and stress, and repetitive motions further add to the risk. We study the prevalence of CTS among a variety of such workers viz., tempo-drivers, masonry workers, bottom-passing shoe workers and tailors. Motor nerve conduction velocity (MNCV) experiments are performed to find out the percentage occurrence of CTS using RMS Aleron 201 electromyography machine. Workers’ gripping strength data is also collected using hand dynamometer (SS25, Biopac MP 150 system, Biopac Inc., USA). MNCV studies of the median nerve are performed on 34 workers belonging to four occupations mentioned; out of them nearly 47% workers are found to have CTS. The results suggest that use of wrist for long working hours (10 hours or more) attribute to the incidence of CTS among listed occupational workers. It is observed that per day work duration of tailors, masonry workers, and tempo-drivers is more than that of bottom-passing shoe workers. However tailors are found to be worst affected owing to frequent pinch force exertions and awkward working posture. Bottom-passing shoe workers are less affected due to their shorter working hours (7-8 hours), simple posture, and sufficient rest breaks.
An Application of a Job Exposure Profile in Work-related Shoulder Disorders Study
Authors: Bao Stephen , Fan Joyce , Silverstein Barbara
Published: October 2013

This study aimed at presenting a method that creates an exposure profile for a combined physical exposure of forceful exertions and work postures. Hand/wrist work posture and forceful exertion data were collected simultaneously through observations from recorded videos from a total of 733 subjects from 12 different workplaces. Combined exposures of the forceful hand exertion and hand/wrist postures were grouped into 32 categories (5 types of forceful exertion each with 3 levels and one exertion category of no forceful exertion, and two categories of wrist flexion/extension postures, (i.e. 5x3+1)x2) = 32). Distributions of the combined exposures were then calculated for each of the subjects. An Exposure Profile Index (EPI) was created by assigning different weights on each of the 32 combined exposure categories. Distribution of the EPI for the eligible 716 subjects was calculated. Logistic regression was performed adjusting for age and gender for the EPI to calculate the odds ratios of being a clinical shoulder case. Clinical shoulder cases were determined by workers’ self-reports and physical examinations performed by a physician.
Virtual Exertions
Authors: Radwin Robert G. , Chen Karen B. , Ponto Kevin , Tredinnick Ross D.
Published: October 2013

This paper introduces the concept of virtual exertions, which utilizes real-time feedback from electromyograms (EMG), combined with tracked body movements, to simulate forceful exertions (e.g. lifting, pushing, and pulling) against projections of virtual reality objects. The user acts as if there is a real object and moves and contracts the same muscles normally used for the desired activities to suggest exerting forces against virtual objects actually viewed in their own hands as they are grasped and moved. In order to create virtual exertions, EMG muscle activity is monitored during rehearsed co-contractions of agonist/antagonist muscles used for specific exertions, and contraction patterns and levels are combined with tracked motion of the user’s body and hands for identifying when the participant is exerting sufficient force to displace the intended object. Continuous 3D visual feedback to the participant displays mechanical work against virtual objects with simulated inertial properties. A pilot study, where four participants performed both actual and virtual dumbbell lifting tasks, observed that ratings of perceived exertions (RPE), biceps EMG recruitment, and localized muscle fatigue (mean power frequency) were consistent with the actual task. Biceps and triceps EMG co-contractions were proportionally greater for the virtual case.
Powered Ambulance Cots
Authors: Sommerich CM , Lavender SA , Umar RZ Radin , Park SH , Li J , Dutt M
Published: October 2013

An experiment was conducted in order to examine the effect of differences in the design of two powered ambulance cots on operators. Experienced EMS workers performed two common tasks, loading and unloading the cots from a simulated ambulance bed. Dependent measures included muscle activity (trunk, shoulder, and arm muscles) and subjective perceptions. Independent variables were cot (Cot R and Cot Y), and weight on the cot (100, 150, and 200 lbs., to simulate patients of different weights). Muscle activity was found to be significantly lower when using Cot R, for both tasks, in comparison to Cot Y. Subjective preferences were mixed, with many subjects preferring the handle design of Cot Y, while preferring Cot R overall. This study showed that it is possible to substantially reduce the physical stress imposed on operators when loading and unloading a cot to and from an ambulance through improvements in cot design.
An Ergonomic Evaluation of Hand-Carried, Track-Type, and Sled-Type Stair Descent Devices Used for High Rise Building Evacuation
Authors: Lavender Steven A. , Mehta Jay P. , Hedman Glenn E. , Park Sanghyun , Reichelt Paul A. , Conrad Karen M.
Published: October 2013

Professional firefighters participated in a study that compared physical demands and task performance measures as three hand-carried devices, three track-type evacuation chairs, and three evacuation sleds were used to transport an occupant down flights of stairs that included two landings. Two staircase widths, 1.1 and 1.3 m, were evaluated as the width of the stairs was hypothesized to affect the dependent measures which included heart rate, electromyographic response, and decent velocity. The data indicate there were trade-offs between the types of evacuation devices with some showing high physical demands on the stairs while others showed high demands on the landings. Overall, track-type devices and sled-type devices resulted in reduced physical demands relative to the hand-carried devices.
Benefit of Adjustability When Depalletizing
Authors: Ramsey Todd , Davis Kermit G , Kotowski Susan E.
Published: October 2013

Manual material handling is very prevalent in warehousing and large home improvement stores. Product is often shipped on pallets and then loaded to carts or pallet jacks. The objective of the current study was to evaluate two potential interventions: an adjustable pallet carousel and adjustable cart, using the NIOSH lifting index. Thirteen experienced males completed de-palletizing tasks under 4 conditions: pallet to flat cart, pallet to adjustable cart, carousel to flat cart, and carousel to adjustable cart. The carousel reduced the LI by about 20% while the adjustable cart had limited impact. Based on the NIOSH LI, the carousel provide a reduction in risk but remained elevated (e.g. LI>3.0) and the adjustable cart was less effective (LI>4.6). Caution is needed to interpret these results as the spine loads may be significantly reduced and provide a different picture.
Writing Aviation Maintenance Procedures That People Can/Will Follow
Authors: Drury Colin G. , Johnson William B.
Published: October 2013

As safety-critical industries attempt to reduce error rates with the high reliance on procedural tasks, the error of “procedure not followed” becomes prominent. This paper focuses on aviation maintenance where the need is still urgent although much HF/E research exists to guide procedure designers. The occupation is tightly regulated, but this type of error is still the most prevalent in studies. In practice, new delivery technologies are emerging but that does not ensure that good HF/E practice is followed. The results of a 2012 FAA workshop are used to identify challenges and map future directions for error reduction.
Two-level Force Input on TouchPad and the Effects of Feedback on Performance
Authors: Sheik-Nainar Mohamed , Ostberg Anna , Matic Nada
Published: October 2013

Human fingers are accustomed to applying force in everyday activities and this dimension is not captured with today’s TouchPads. We developed a prototype TouchPad with force sensors capable of detecting force applied by a finger. We evaluated two-level force interaction by creating a modified Fitts’ task with two colored targets – one selected by light press and the other selected by heavy press. We evaluated the effects of modality of force level feedback on task performance time and error using audio and visual feedback and compared it to a no-feedback control condition. Results showed no difference in Fitts’ movement time between the various feedback conditions. Most participants preferred the simple audio feedback over other feedbacks. Many participants also commented that feedback helped them learn the force thresholds for each level but with practice they would prefer to have no additional force level feedback.
Managing Performance Complexity and Manpower Sustainability with Systems Engineering
Authors: Ahram Tareq , Karwowski Waldemar , Amaba Ben
Published: October 2013

Researchers and engineers are finding themselves in a dilemma where supply is not meeting demand with an exponential growing population and complex systems putting more demands on power systems. The demand and supply of natural resources used to generate, transmit, and consume the power make the challenge for the human race even more complex. This research paper provides a motivation and quest for sustainable human factors and ergonomics (HF/E), specifically human performance elements in complex systems design and development. The advancements achieved in complex systems engineering show that the application of sustainable HF/E can lead to highly sophisticated and useable applications to ensure sustainability of limited resources such as energy and clean water. The integration of HF/E and Human-Centered design concepts with systems engineering proves critical for building complex systems and to support meeting the needs for future workforce skills and capabilities.
Optical Detection of Buried Explosive Hazards
Authors: Staszewski James J. , Hibbitts Charles A. , Bailey Drew , Bursley James , Davis Luke
Published: October 2013

Visual detection of soil disturbances is an effective, but imperfect method for detecting buried explosive threats such as landmines and improvised explosive devices (IEDs). Building upon prior studies of optical detection, this study uses signal detection methods to measure observer sensitivity to images of soil disturbances asking “How detectable are disturbed soil signatures recorded in visible (VIS), short-wave infrared (SWIR), and thermal infrared (TIR) bands?” “How effective is each band for detection?” and “How is signature salience in each band effected by extended exposure in the natural environment?” Young adults viewed photos showing either soil disturbed by landmine burial or adjacent undisturbed surfaces and made yes/no decisions about the presence of a disturbance. Stimuli spanned a six-week time period over which VIS, SWIR, and TIR images were collected. Results show that (a) substantial signal strength lasts over the six-week period, (b) generally, SWIR and VIS show consistently strong performance for large anti-tank mines and (c) the soil signatures for the small, anti-personnel mine stay remarkably strong in SWIR. TIR sensitivity lags SWIR and VIS, but shows promising hit rates for anti-tank mine signatures under some conditions. Generally, results show that optical detection, particularly using the SWIR and VIS bands, shows promise for explosive hazards detection, at least under the conditions observed.
Prefrontal Cortex Activity During Walking While Multitasking
Authors: Hill Audrey , Bohil Corey , Lewis Joanna , Neider Mark
Published: October 2013

Previous work has demonstrated that walking while carrying out secondary cognitive tasks (e.g., talking on a cell phone) can lead to decrements in performance on both tasks. Studying these decrements in an ecologically valid setting has generally been limited to behavioral data (e.g., error rates, task completion times). Recently, the advent of portable neuroimaging technology – specifically, functional Near-Infrared spectroscopy (fNIR) – has made it possible to measure cortical activity while a participant is walking. We conducted an experiment using fNIR to measure cortical blood flow (in dorsolateral prefrontal cortex) while participants walked and carried out cognitive tasks of varying difficulty. Participants walked 25 feet on each trial, and performed either a low-load condition (counting backward by 1), or a high-load condition (counting backward by 7). Participants in the high load condition walked more slowly and performed the counting task more slowly and with more errors than those in the low load condition. fNIR results indicated a higher level of Prefrontal Cortex (PFC) activity during the high load condition. The difference in blood flow between load conditions was slightly more pronounced in the left hemisphere than in the right.
The Use of Paired Comparisons for Evaluating Complex Route Matching Performance in a Spatial Awareness Task
Authors: Yee Anthony Soung , Milgram Paul
Published: October 2013

A method is proposed for evaluating participants’ performance in a global spatial awareness task involving identification of complex winding routes. Rather than using coarse measures of spatial error, the method of paired comparisons employs impartial judges to compare sets of aggregated experimental data generated by the participants with respect closeness in shape to the target route. The method was applied to a set of data in an experimental investigation of the effect of height on a participant’s ability to identify the route he had just flown over (in a 20 second video). Seven participants performed a total of 48 trials in a 4 (heights) X 2 (trial blocks) within-subjects experiment. Results from the paired comparison analysis suggested that height had a statistically significant effect on correct route identification. Of equal importance in the context of the present paper, the method of paired comparison analysis proved to be effective in quantifying performance data that did not otherwise lend themselves to conventional methods of quantification.
Temporal Complexity in Team Coordination Associated with Increased Performance in a Fast-Paced Puzzle Task
Authors: Strang Adam J. , Epling Samantha , Funke Gregory J. , Russell Sheldon M.
Published: October 2013

Coordination is a critical component of team performance. Nonlinear time-series measures, such as Sample Entropy (SEn), provide a novel means to examine temporal structure in team coordination. The goal for this study was to apply SEn to the continuous motor responses (gamepad button presses) of dyadic teams who performed a fast-paced puzzle task (Quadra – a variant of videogame Tetris). Inferential analyses were used to: a) determine if meaningful (i.e., deterministic) temporal structure existed in team responses using SEn, and b) examine correlations between team performance and coordination metrics (including SEn). Results confirmed that meaningful temporal structure existed in the sequential type and time of team motor responses. In addition, SEn was the only coordination metric to exhibit a significant relationship with team performance outcomes. Together, these findings support the viability and salience of nonlinear measures such as SEn in assessment of team coordination.