bluuebunny/crossref_metadata_2025 huggingface dataset:
Text Readability and Drivers’ Reading Time
Authors: Ghazizadeh Mahtab , Venkatraman Vindhya , Torres Miralis , Gibson Madeleine C. , Lee John D. , Boyle Linda Ng
Published: October 2013

Internet access, vehicle diagnostics, and real-time communication are becoming increasingly common in all vehicles and the complexity of the information displayed is a major concern. Current guidelines focus on the number of characters in a text message, but other measures of text readability might be more sensitive. This study examined how well different metrics of text readability predict the time it takes a driver to read a message on an in-vehicle display. Participants completed reading tasks while seated in the driver’s seat of a driving simulator. Occlusion goggles were used to mimic the timesharing between the driving task and the secondary reading tasks, according to the ISO 16673 (2007) guidelines. The results showed that message length (number of characters) predicts the total time spent on the task (Total Shutter Open Time [TSOT]) and that the combination of number of words in the message and Shannon entropy of the message predicts TSOT only as well as number of characters alone. Applying the model human processor calculations of reading rates (Card, Moran, & Newell, 1983) showed that participants likely read the messages word-byword in successive saccades, instead of letter-by-letter or phrase-by-phrase. Findings provide direction for more in-depth lexical analyses of text readability related to in-vehicle displays.
Looking or Listening?
Authors: Mizobuchi Sachi , Chignell Mark , Canella David , Eizenman Moshe , Yoshizu Sayaka , Sannomiya Chihiro , Nawa Kazunari
Published: October 2013

We conducted an experiment with 22 participants to investigate the effect of presentation style of a secondary task on a 1-D tracking task that simulated gap control in driving. Participants operated the tracking task with a foot pedal while performing a secondary task (counting vowels in a list of multiple letters) under conditions involving different modalities (audio/ visual), presentation styles (simultaneous/ sequential), task complexity (the number of distractors), and time dependency (list length). Our results showed that audio conditions with a longer and/or more complex secondary task did not improve primary (tracking) task performance, even though eye gaze dwelling time on the primary monitor in these cases tended to be substantially longer than the corresponding times in visual conditions. For a more complex version of the secondary task (longer list lengths) visual presentation of the task all at once (simultaneously) led to better performance then sequential presentation (whether visual or auditory). When given a choice people also tended to prefer simultaneous visual presentation of the secondary task. We discuss the effect of presentation modality of the secondary task in terms of its implications for user interface design in vehicles.
Inattentional Blindness in a Simulated Driving Task
Authors: Kennedy Kellie D. , Bliss James P.
Published: October 2013

This study was a subset of a larger investigation on the role of task load on IB occurrences in the context of driving. The focus of this study was the relationship between mental demand and inattentional blindness (IB) occurrences for a critical stimulus that is directly relevant to primary task performance. Forty-four undergraduates followed a series of auditory directives in a simulated driving environment to reach a destination. The final directive instructed participants to turn left at an intersection clearly marked with a “no left turn” sign. Of the total number of participants in this study, 79.5% (35 of 44) failed to detect the “no-left turn” road sign critical stimulus. Results revealed that individuals who detected the “no left turn” sign had significantly higher scores on the mental demand component of the NASA-TLX compared to those who failed to detect the sign. The negative relationship between IB occurrences and the subjective mental demand ratings suggest another factor, such as task engagement, may also impact IB occurrences.
Gender Factor in Lane Keeping and Speech Comprehension Dual Tasks
Authors: Cao Shi , Liu Yili
Published: October 2013

Driving-related dual-task performance has been studied by many transportation human factors studies; however, previous studies on the effects of cognitive load on driving performance have obtained mixed results. In the current study, we focus on the analysis of the effect of gender factor on lane keeping and speech comprehension dual-task performance with improved experimental control of potential confounding factors. The results showed that the speech comprehension task did not significantly affect lane keeping performance when priority was given to lane keeping, at least within the approximate 80 min of the experiment. The speech comprehension performance in dual-task showed a speed-accuracy tradeoff that sacrificed accuracy for speed. Males showed better lane keeping ability in single-task, because the increase of standard deviation of lane position ( SDLP) with higher driving speed was less dramatic in males than females. Females showed better speech comprehension ability indicated by higher comprehension correct rate. The interaction between the gender and dual-task factors was only significant in a three-way interaction involving vehicle speed. It shows that females, in comparison to males, had a trend of dual-task lane keeping improvement with increasing speed. Implications from the results are discussed.
Supporting drivers in concurrent lane and speed tracking tasks with novel visual, auditory, and tactile speedometer displays
Authors: Yang Shiyan , You No Young , Ferris Thomas K.
Published: October 2013

Driving can be described as performing multiple concurrent tracking tasks. These tasks primarily involve processing visual feedback, and the competition for visual resources may limit overall performance. Providing feedback via different sensory channels may improve multi-tracking performance; however, not much is known about basic human abilities to perform multiple controlled tracking tasks, nor about the use of nonvisual feedback in those tasks. This study measured the performance of participants in lane and speed tracking tasks when speed information was encoded into ambient visual, auditory, and tactile displays. The findings show that all three of these novel displays significantly improved speed tracking over a baseline condition without significantly impacting lane tracking performance. Dual-tracking performance was best supported with ambient visual and auditory displays, and participants preferred the auditory and tactile displays. The findings provide insight into multi-tracking abilities when feedback is distributed among sensory channels, and can inform design of in-vehicle displays.
Drivers’ Selected Settings for Adaptive Cruise Control (ACC)
Authors: Xiong Huimin , Boyle Linda Ng
Published: October 2013

Adaptive Cruise Control (ACC) is a system that assists drivers on longitudinal control by automatically adjusting the throttle. Users can set the speed and gap setting based on their driving preferences. In this study, drivers’ ACC use pattern and selection choices are examined based on their level of experience and geographical location. Experienced ACC users from urban settings in Washington are compared to less urbanized areas in Iowa. Information on novice ACC users were also collected in Washington and compared with experienced ACC users within the same area. The outcomes show that although similar use patterns do exist, there are differences in geographical locations and experience levels that impact drivers’ choice of ACC settings. In Iowa, experienced ACC drivers select faster speed and closer time headway distance than drivers in Washington State. This suggests that use of ACC differ given environmental surroundings. Within Washington, experienced ACC users set faster speed, closer time headway distance, and intervened less compared with novice ACC users. This suggests that drivers’ behavior may change with greater exposure to ACC, which can provide insights on drivers’ automation reliance after extended use.
The effect of context and ergonomic design of traffic signs on driver comprehension – a preliminary evaluation
Authors: Ben-Bassat Tamar
Published: October 2013

A previous study found high and statistically significant correlations between the probability of compre-hending a traffic sign and the extent to which the sign complies with three ergonomic principles of design: sign-content compatibility, familiarity, and standardization. The current study examined whether providing participants with the context in which the sign is presented might help them understand the meaning of the sign. In addition, the study presented a preliminary attempt to overcome misunderstood and poorly unders-tood signs, according to two ergonomic guidelines (compatibility and standardization). Participants were presented with 20 local road signs, both with and without providing the context in which the signs were presented, and were asked to describe their meaning. In a second experiment, the most poorly understood signs were redesigned and driver comprehension was tested again, using a new set of participants. Results showed that context had a significant positive effect on sign comprehension, and partly showed an increase in driver understanding of signs as a result of ergonomic-based redesign.
Role of Expectancy, Motion and Overhead Lighting on Nighttime Visibility
Authors: Bhagavathula Rajaram , Gibbons Ronald B.
Published: October 2013

More than half of the pedestrian fatalities occur at night. It is important to understand the factors that lead to pedestrian detection for designing and implementing effective countermeasures in order to reduce pedes-trian fatalities. Research has shown that expectancy, motion and overhead lighting affect pedestrian visibil-ity. This goal of this study is to understand the combined effect of these three factors on nighttime visibil-ity. Twenty four participants were recruited to drive on a test track under different conditions of expectancy and overhead lighting. The participants were asked to identify static and moving objects. The results showed that as the level of expectancy increases the detection distances also increase. Moving objects were detected from farther than static objects and presence of overhead lighting also increased the detection dis-tances. Motion tends to draw more attention than expectancy when detecting new objects. These results have implications in the areas of pedestrian safety, novice driver training and work zone safety. They also reiterate the safety benefits of providing overhead lighting at high pedestrian-vehicle conflict areas.
Associations between drivers’ safety records and driving styles
Authors: Merrikhpour Maryam , Donmez Birsen , Wang Chongbo , Hayes Benjamin , Grush Bern
Published: October 2013

Identifying potentially at-risk drivers based on their driving styles may help target these individuals with effective countermeasures, such as individual counselling, triggering alarms for degraded driving style, and assessing risk for insurance. The primary objective of this research was to investigate the relation between riskiness (as measured through self-reported at-fault crash and moving violation records in the previous five years) and driving style, as measured through speed and acceleration profiles. A field trial was conducted with 40 participants in two age groups: younger (ages 25 to 35) and older (ages 45 to 65). Through an initial questionnaire, 19 drivers with worse safety records (defined as one or more at-fault traffic crashes in the last five years and/or two or more at fault crashes since licensure and/or two or more speeding tickets in the last five years) and 21 drivers with better safety records (defined as no at-fault crashes in the last five years and no more than one at-fault crash since licensure and no more than one speeding ticket in the last five years) were selected for participation. Within each group, age was approximately counterbalanced. Naturalistic data including vehicle position, speed, and acceleration were collected through a GPS-enabled telematics platform, which was installed in participants’ vehicles. Data were collected from each participant over a one month period. No statistically significant relation was identified between safety record and driving style. However, three groups of drivers emerged in a cluster analysis, with one group exhibiting speeding and abrupt deceleration behaviours significantly less than the other two. These other two groups, which did exhibit riskier behaviours, differed regarding the extent of which behaviour they exhibited more. One group was more likely to exhibit speeding and the other more likely to exhibit abrupt acceleration and deceleration behaviours.
Developing and Testing a Tool for Human Factors Design and Evaluation
Authors: Ford R. L. , Andre T. S. , Sebok A. , Meyer R. E. , Laux L. , Bzostek J. , Wong D. T.
Published: October 2013

Designing complex systems such as those used in spaceflight operations requires a coordinated effort among a variety of engineering teams. In these large-scale efforts, it is not uncommon for human factors issues to be missed until late in the design process, perhaps when an integration test is performed. To help solve this problem, TiER1 Performance Solutions and Alion Science and Technology developed H-FAST (Human Factors Analysis Support Tool). H-FAST is a research and development effort to increase human factors awareness among design engineers, facilitate communication between human factors engineers and design engineers, and promote the application of human factors best practices earlier in the design cycle. H-FAST also provides detailed guidance regarding human factors evaluations and the capability to store data and provide feedback on the results of these evaluations. In this paper, we describe the development strategy for H-FAST and report on our progress to date. In particular, we describe the identification and development of relevant human factors information to include in the tool, discuss the methods and results of a user test at NASA, and provide an overview of our plans forward.
Janus
Authors: John Mark F.
Published: October 2013

Operators must increasingly multi-task their supervision across multiple systems. This multi-tasking supervision requires effective support tools to allow operators to quickly scan across systems and direct their attention to problems. Typical plant control displays, as well as many dashboard designs, offer too much data, and take up too much room, for efficient scanning. A new mini-dashboard display, called a Janus display, supports more effective scanning by incorporating a number of human factors design principles for supporting supervision and rapid scanning. The Janus design and these principles are described here. This description is followed by report of a laboratory study confirming the performance benefits of Janus and a description of the process of developing a Janus display for a network telecommunications system. Janus displays offer significant benefits for supplementing, rather than replacing, primary system displays.
Visual representation of connectivity information for efficient system understanding
Authors: Romero David Dorantes , Graven Tone-Grete
Published: October 2013

This paper describes how User Center Design (UCD) methodology has been applied to develop a new visualization concept to support operation and maintenance of an oil and gas facility. The ultimate goal of the work is to improve energy efficiency in plant operation by creating an interactive visual representation of process and equipment dependencies at a modern industrial plant. This visualization concept aims to highlight important information which is today hidden in disparate information sources, and to support collaboration between personnel from different technical disciplines. The paper explains how user studies were used to promote the knowledge elicitation process and how UCD methods are being applied to the definition of functional requirements and to the creation of early concept prototypes.
Comparing Physical and Virtual Simulation Use in UGV Research
Authors: Talone Andrew , Fincannon Thomas , Schuster David , Jentsch Florian , Hudson Irwin
Published: October 2013

This paper details lessons learned from human-robot interaction (HRI) research conducted with physical and virtual unmanned vehicle (UV) test beds. Two subject matter experts (SMEs) were interviewed regarding their experiences using the test beds, and content was categorized to address validity issues and practical concerns that researchers should consider when studying human operation of UVs. Interview data revealed that from a practical standpoint, virtual simulation is favored over physical simulation. Virtual simulation was also highlighted for permitting greater internal and construct validity than physical simulation. For tele-operation studies, however, physical simulation was identified as more externally valid than virtual simulation, but this advantage diminished for research at higher levels of autonomy. In general, this paper can serve as a resource for researchers who must choose between the two simulation methods.
Development of a Distributed Representative Human Model Generation and Analysis System for Multiple-Size Product Design
Authors: Lee Baekhee , Jung Kihyo , You Heecheon
Published: October 2013

The aim of the study is to develop a distributed representative human model (DRHM) generation and analysis system. DRHMs are used for a product with multiple-size categories such as clothing and gloves. It is not easy for a product designer to explore an optimal sizing system by applying various DRHM generation methods because of their complexity and time demands. The existing studies related to DRHM generation protocols and RHM generation methods of three digital human model simulation systems (Jack®, RAMSIS®, and CATIA Human®) were reviewed in the study. The DRHM generation protocol was implemented by providing sophisticated interfaces which offer various statistical and visualization techniques. The system can analyze the multivariate accommodation percentage of a sizing system, provide body sizes of generated DRHMs, and visualize generated DRHMs. The DRHM generation and analysis system can be of great use to efficiently determine an optimal sizing system for a multiple-size product by comparing various sizing system candidates with each other.
Spatial Orientation Aware Smartphones for Tele-operated Robot Control in Military Environments
Authors: Walker Amber M. , Miller David P. , Ling Chen
Published: October 2013

We report an experiment conducted to assess the usability of a smartphone-based controller for use by dismounted troops using unmanned ground vehicles for reconnaissance and surveillance. A virtual joystick controller is compared to a specially designed tilt-based controller intended to limit the device’s touch interface while providing intuitive control. Participants drove a small tracked robot on an indoor course using both controller options where metrics regarding performance, mental workload, and user satisfaction represented various measures of controller usability. Results indicate that the tilt controller is preferred by users and performs equally as well, if not better, on most performance metrics. These results support the development of a smartphone-based control option for military robotics, with a focus on gestural input methods which overcome deficiencies of current touch-based systems, namely lack of physical feedback, high attention demands, and unreliability in field environments.
Speaking the user’s language
Authors: Campbell Susan G. , Wayland Sarah C. , Goldman Alina , Blok Sergey , Powell Allison L.
Published: October 2013

Translation technology, including translation memory software, can make the work of professional translators more efficient and effective. Using a multi-disciplinary approach with converging methods, we evaluated translation memory software in the context of a work environment in which it was to be deployed. Our evaluation had three phases: (1) a contextual inquiry of translation practice, (2) a usability test of the candidate software package, and (3) a heuristic evaluation to evaluate the ways that the software package matched or did not match the needs identified in the contextual inquiry. From this, we derived a set of recommendations for incorporating translation technology into the organization’s processes. Suggestions included incorporating shared translation memory in the workflow and working with the software vendor to improve text handling for non-European languages. Problems with both the software under evaluation and standard workplace software highlighted the need for developers to evaluate language technology with non-Roman orthography.
The Effects of Image Set Size and Time Pressure on Human Performance and Mental Workload in a Cyber Image Search Task
Authors: Zhao Guozhen , Wu Changxu
Published: October 2013

Visual image search on the web is a common behavior that provides people immediate access to the world of published graphical information and the power to search for a desired image. Previous research in the visual search literature primarily focused on the visual search performance (search speed and accuracy), and few studies paid attention to the investment of mental resources in a visual search task. In this study, 40 participants were recruited to perform an image search task. Image set size and time pressure served as two within-subject variables. Performance was evaluated in terms of image search reaction time (RT), the slope of RT × set size function, and search accuracy. Mental workload was assessed based on four physiological indices (heart rate, the power in the 0.1 Hz component of heart rate variability, respiration, and endogenous eye blink) and subjective ratings. The current study found that, regardless of the manipulation of time pressure, the average image search reaction time decreased as the set size increased, producing shallow slopes of the RT × set size functions. There was a positive relationship between task difficulty and mental workload. Higher mental workload was observed when people performed an image search task under time pressure. Moreover, the power in the 0.1 Hz component of heart rate variability was more sensitive to measures relatively low or moderate changes in mental workload.
Usability Analysis of a Business Process Management Software Platform
Authors: Blumberg Eric J. , Kelly Alan C. , Olmstead Ryan , Youmans Robert J.
Published: October 2013

This study reports the results of a usability analysis on a leading suite of software for the creation, management, tracking, and automation of business process management (BPM) software, a system designed to make collaborative work quicker and easier to complete. The analysis focuses on two tools within the suite, and their effectiveness in enabling end users to model processes. Diverse methodologies that may be of interest to other BPM developers were used to examine how users would conceptualize, model, and execute processes using the software. A number of resulting recommendations are made to enhance usability and to better examine similar webbased software.
The Evaluation of a Tactile Display for Dismounted Soldiers in a Virtusphere Environment
Authors: Chapman Roger J. , Nemec MAJ Lou , Ness COL James
Published: October 2013

Here we describe the evaluation of the THATO (TeleHaptic Assistance for Tactical Operations) mobile tactile messaging system in a “virtusphere” environment. THATO was developed to aid dismounted soldier-to-soldier communications, situation awareness, and navigation during tactical operations. The THATO Android application stores tactile message designs that are instantiated with context specifics and played through its interface to Tactile Control Units (TCUs) when a command is received from another soldier, the soldier’s location relative to a planned route or landmark/entity of interest triggers a message, or the soldier requests information (e.g. through voice recognition). Two previous evaluations of THATO and its evolving language produced promising results, but only six participants were involved in each and the fidelity was limited with participants simply standing and verbalizing their interpretations of messages played in a random order. Here the results of a lab experiment are presented where twenty participants were involved and fidelity was improved by having participants also respond to messages with appropriate physical behaviors within a 10 foot hollow sphere capable of rotating upon wheels placed beneath it. Overall, participants received twelve types of message, each with between one and four pieces of information, and recognized all parts of a message 95.9% of the time.
Using Learners’ Internal States to Drive Feedback Decisions
Authors: Vogel-Walcutt Jennifer J. , Carper Teresa Marino , Bowers Clint , Nicholson Denise
Published: October 2013

The overarching goal of learner assessments is to identify areas of skill and deficit and to use this infor-mation to guide future instruction or error correction through feedback. To date, a variety of methods have been used to better understand individual learners. However, the tools used to assess learners’ internal states have only allowed researchers to infer these states and, as a result, the information provided lacks the prescriptive specificity needed to most appropriately address learners’ needs. The technological advances of current neuro-physiological measures may provide such specificity in real-time learning environments. These data show preliminary support for the use of electroencephalography measurements of workload and engagement to predict learning and knowledge acquisition. Additionally, the data suggest that the relation-ship between these two internal states may differ based on the level of information being assessed.
Error Training and Adaptive Remediation
Authors: McDermott Patricia L. , Gronowski Mark R. , Carolan Thomas F. , Fisher Alia
Published: October 2013

An experiment investigated the relative effectiveness of three training strategies for improving transfer performance in a cognitively complex decision-making task. Error Management is an exploratory training approach in which trainees learn by exploring and making errors. Error Prevention training includes structured training on likely errors. Adaptive Remediation is error management training supplemented with practice scenarios tailored to the types of errors made. The study is an important addition to the literature because it examines training and transfer performance in a cognitively complex militarily-relevant task. Participants used a digital system to plan, execute, and monitor unmanned vehicles in reconnaissance missions. Transfer scenarios tested the ability to adapt what was learned when attempting new tasks and in an error prone environment. The results showed that transfer performance was better when participants did not complete adaptive remediation scenarios. It is believed that the adaptive remediation tasks encouraged participants to focus on single tasks and as a result they spent less time exploring the whole task. The implication is that the cost and effort required to create an adaptive remediation training program may not be justified in a cognitively complex task like the planning task used in the experiment.
Examining an Improved Pilot Training Program for TCAS
Authors: Fleming Elizabeth S. , Pritchett Amy R.
Published: October 2013

This paper discusses the development and evaluation of a training program intended to train pilots to understand Traffic alert and Collision Avoidance System (TCAS) use for collision avoidance in the actual traffic and operational environment. The training program was developed using the integration of two training methods: Demonstration Based Training and Event Based Training. The impact of the training program was evaluated by comparing of two experiments examining pilot response to TCAS advisories in an aircraft simulator that incorporated the full context of an air traffic environment. Pilot participants were initially trained using the improved training program, and their performance was compared to the performance of baseline pilots who did not complete the training program. An analysis of pilot responses showed that overall the training program had a significant impact on the pilots’ behavior and response to TCAS advisories.
Producing reusable engineered systems through ontology: implementing an information sciences approach to architecture-driven, model-based, concurrent engineering
Authors: Ball George L. , Runge Christopher (Kit)
Published: October 2013

The engineering community faces multiple challenges as it moves toward a future that will consist of virtual reality, model-based enterprises, and a heavy reliance on simulation for requirements development, design, manufacturing, assembly, and training for future products. The focus on model-based activities (e.g. design, systems engineering, manufacturing) is seen as a way to better reuse knowledge, ensure higher quality, and reduce costs through virtual design and testing. However, the combination of discipline-focused decomposition, the functional to physical progression, proprietary data formats, and poor communication between disciplines due to different language and contexts leads to longer development times, increased rework, and a failure in product realization. Raytheon has been researching aspects of this future, targeted at shortening the product development lifecycle by an order of magnitude. One such recent Raytheon-funded study has indicated that a potentially more complete approach might be to address the problem from an information sciences perspective and the adoption of “product” models as the primary representation. In particular, the development of a workable rapid engineering environment will require an information architecture-leveraging product ontology designed specifically for this type of approach.
Acute brain ischemia as a complication of the Ehlers–Danlos syndrome, the case series
Authors: Pajak Michal , Majos Marcin A , Szubert Wojciech , Stefanczyk Ludomir , Majos Agata
Published: October 2013

Vascular type of Ehlers–Danlos syndrome involves many severe complications leading not only to organ-specific symptoms but often ends in a sudden death. The aim of this paper was to present a diagnostic possibilities and its efficiency rate in patients with vascular complications of Ehlers–Danlos syndrome who suffered from artery dissection resulting in acute brain or limb ischemia. We analysed three patients with diagnosed Ehlers–Danlos syndrome who were referred to radiology department for diagnostic imaging of affected vascular beds, each experienced brain ischemia. The paper also aims at offering some general recommendations for patients suffering from possible complications of type IV Ehlers–Danlos syndrome basing on our own experience and available literature data.
Nodular fasciitis of the hand: excision preserving ‘vital’ structures
Authors: Al-Qattan M. M. , Arafah M. M.
Published: October 2013

Nodular fasciitis is an extremely rare benign fibrous tumour of the hand. Although benign, the tumour is frequently adherent to tendons/nerves and joints of the hand. However, the tumour may spontaneously regress and does not tend to recur following excision with histologically positive margins. For the last 20 years, the author has adopted a specific management approach for these and other benign fibrous tumours of the hand. Following the clinical/radiological diagnosis, tumour excision is done preserving ‘vital’ structures within the hand. The diagnosis is confirmed histologically and by immune stains, and the patient is then followed up for local recurrence. Over a 20-year period, the author has treated four cases of nodular fasciitis of the hand using this management approach. Despite the positive margins in all cases, there were no recurrences at a minimum follow-up interval of 3 years.
Subphysiological Compressive Loading Reduces Apoptosis Following Acute Impact Injury in a Porcine Cartilage Model
Authors: Vernon Lauren , Abadin Andre , Wilensky David , Huang C.-Y. Charles , Kaplan Lee
Published: October 2013

Background:

Acute cartilage injuries induce cell death and are associated with an increased incidence of osteoarthritis development later in life. The objective of this study was to investigate the effect of posttraumatic cyclic compressive loading on chondrocyte viability and apoptosis in porcine articular cartilage plugs.

Hypothesis:

Compressive loading of acutely injured cartilage can maintain chondrocyte viability by reducing apoptosis after a traumatic impact injury.

Study Design:

In vitro controlled laboratory study.

Level of Evidence:

Level 5.

Methods:

Each experiment compared 4 test groups: control, impact, impact with compressive loading (either 0.5 or 0.8 MPa), and no impact but compressive loading (n = 15 per group). Flat, full-thickness articular cartilage plugs were harvested from the trochlear region of porcine knees. A drop tower was utilized to introduce an impact injury. The articular plugs were subjected to two 30-minute cycles of either 0.5 or 0.8 MPa of dynamic loading. Cell viability, apoptosis, and gene expression of samples were evaluated 24 hours postimpaction.

Results:

Cell viability staining showed that 0.5 MPa of dynamic compressive loading increased cell viability compared with the impact group. Apoptotic analysis revealed a decrease in apoptotic expression in the group with 0.5 MPa of dynamic compressive loading compared with the impact group. Significantly higher caspase 3 and lower collagen II expressions were observed in impacted samples without compressive loading, compared with those with. Compressive loading of nonimpacted samples significantly increased collagen II and decreased caspase 3 expressions.

Conclusion:

In this porcine in vitro model, dynamic compressive loading at subphysiological levels immediately following impact injury decreases apoptotic expression, thereby maintaining chondrocyte viability.

Clinical Relevance:

Therapeutic exercises could be designed to deliver subphysiological loading to the injured cartilage, thereby minimizing injury.
Inequalities in Risks and Outcomes in a Health Transitioning Country
Authors: Yiengprugsawan Vasoontara , Friel Sharon , Seubsman Sam-ang , Sleigh Adrian C. ,   The Thai Cohort Study Team
Published: October 2013

This article reviews inequalities in health risks and outcomes based on a large longitudinal cohort study of distance-learning adult students enrolled at Sukhothai Thammathirat Open University ( n = 87,134). The study began in 2005 and the first follow-up was completed in 2009. Risks analyzed for health inequalities were divided into demographic, socioeconomic, geographical, behavioral, and environmental groups. Unequal risks and outcomes identified that would be amenable to policy interventions in transitional Thailand include the following: heat stress—contributing to many adverse outcomes, including occupational injury, psychological distress, and kidney disease; urbanization—unhealthy eating, sedentary lifestyles, low social capital, and poor mental health; obesity—increasingly common especially with rising income and age among men; and injury—big problem for young males and associated with excessive alcohol and dangerous transport. These substantial inequalities require attention from multisectoral policy makers to reduce the gaps and improve health of the Thai population.
Critical Issues in the Identification of Gifted Students With Co-Existing Disabilities
Authors: Gilman Barbara Jackson , Lovecky Deirdre V. , Kearney Kathi , Peters Daniel B. , Wasserman John D. , Silverman Linda Kreger , Postma Michael G. , Robinson Nancy M. , Amend Edward R. , Ryder-Schoeck Michelle , Curry Patricia Hedges , Lyon Sally K. , Rogers Karen B. , Collins Linda E. , Charlebois Gerry M. , Harsin Colleen M. , Rimm Sylvia B.
Published: October 2013

Federal law ensures all students with disabilities the right to a Free, Appropriate Public Education (FAPE). However, current policies governing a student’s eligibility for services may contribute to the underidentification of gifted children with co-existing disabilities—the Twice-Exceptional. The emphasis on below-grade-level (or lower) performance, without regard to ability or potential weaknesses, misses twice-exceptional students. Those who perform at grade level, by using advanced conceptual abilities and hard work to compensate, may still require interventions and accommodations to manage increasing educational demands. Otherwise, college and even high school graduation may be out of reach. This article reviews changing laws and policies, explores case studies of twice-exceptional students missed, and examines the diagnosis of twice-exceptionality through comprehensive assessment. Appropriate best practices for the identification of twice-exceptional learners, maintenance of their civil rights, and provision of FAPE are offered for educators, parents, advocates, and legislators as federal, state, and district laws/policies evolve.
Neutropenia in HIV-Infected Kenyan Women Receiving Triple Antiretroviral Prophylaxis to Prevent Mother-to-Child HIV Transmission Is Not Associated with Serious Clinical Sequelae
Authors: Iuliano A. Danielle , Weidle Paul J. , Brooks John T. , Masaba Rose , Girde Sonali , Ndivo Richard , Ogindo Paul , Omolo Paul , Zeh Clement , Thomas Timothy K.
Published: October 2013

Background:

Absolute neutrophil counts (ANCs) are lower in East African adults. To assess the impact of lower ANCs, we reviewed data from HIV-infected Kenyan women receiving antiretroviral therapy antepartum and postpartum.

Methods:

The Kisumu Breastfeeding Study (KiBS) participants received an antiretroviral regimen from 34 weeks’ gestation through 6 months postpartum. Measured ANCs and subsequent illnesses were reviewed. Adverse events (AEs) potentially attributable to neutropenia were identified, and ANCs were graded using the 2004 Division of AIDS table for Grading the Severity of AEs.

Results:

Among 478 women with ≥1 postpartum ANC measured, 298 (62.1%) women met criteria for an AE (<1.3 × 109 cells/L). Of those, 38 (12.5%) women experienced a nonlife-threatening illness potentially attributable to neutropenia.

Conclusion:

More than half of KiBS women met criteria for neutropenia. The mild clinical experience of most participants with low ANCs supports that these values might be typical for this population and may not result in adverse clinical sequelae.
Hybrid laser arc welding of X80 and X120 steel grade
Authors: Gook S. , Gumenyuk A. , Rethmeier M.
Published: October 2013

The aim of the present work was to investigate the possibilities of hybrid laser arc welding regarding reliable production of longitudinal welds of high strength pipe steels X80 and X120 and to evaluate achievable mechanical properties of laser hybrid welds. The study focused on weld toughness examination in low temperature range up to −60°C. Suitable filler materials were identified in the context of this task. It could be shown that metal cored electrodes guaranteed sufficient Charpy impact toughness at low temperature for both investigated materials. Modern arc welding technologies such as modified pulsed spray arc were used to promote deeper penetration of the filler material into the narrow laser welding gap. Edge preparation with a 14 mm deep root face was considered as optimum, because no penetration of the filler material could be detected beyond this depth limit, and therefore, any metallurgical influences on the weld metal properties through the welding wire could be excluded.
Friction stir welding of co-cast aluminium clad sheet
Authors: Fallu J. , Izadi H. , Gerlich A. P.
Published: October 2013

The effects of welding parameters on material consolidation are examined during friction stir butt welding of 2 mm Al 5083 alloy aluminium sheet with a surface cladding of Al 3025 alloy, which was co-cast from the melt. The influence of welding parameters on joint consolidation is investigated when tool revolutions per minute, travel speed and penetration depth were varied. It was found that modifying the pin of the welding tool to have a two-flat profile improves material consolidation and avoids defect formation during welding, and optimum welding parameters involve a combination of high tool rotation speed and travel speed. Optical and electron microscopy revealed that the integrity of the surface cladding layer could be maintained during friction stir welding while avoiding defect formation within the stir zone of the weld. The tensile strength of the joint was ∼58% of the base material due to softening within the stir zone.
Quantitative infrared analysis of welding processes: temperature measurement during RSW and CMT-MIG welding
Authors: Frappier R. , Benoit A. , Paillard P. , Baudin T. , Le Gall R. , Dupuy T.
Published: October 2013

This article deals with temperature characterisation by infrared thermography during welding. To demonstrate the versatility of this technique, two welding processes were investigated with different materials: cold metal transfer metal inert gas welding of al alloy and resistance spot welding of galvanised steel. Two experimental methods were used to characterise temperature without requiring implementation of thermocouples. The validity of these methods is demonstrated by metallurgical characterisations. The error on the measured values of temperature is assessed regarding the initial uncertainty on the apparent surface emissivity. The results show that it is possible to obtain absolute temperature values, cooling rates and informative visualisation of temperature gradients with a reasonable uncertainty.
Comment on ‘Constant intermittent flow of dislocations: Central problems in plasticity’ by L. M. Brown
Authors: Mughrabi H.
Published: October 2013

Brown′s recent impressive review on crystal plasticity is discussed, in particular with respect to the results obtained on stage II work hardening in face-centred cubic crystals. An important issue is the modelling of slip bands as ellipsoids which allows Brown to derive in analytical form many properties of slip bands, in agreement with observation. Nonetheless, some questions are raised as to whether the representation of slip bands as ellipsoids conforms to reality or whether it should be viewed as a convenient approximation for the purpose of an analytical description of a complex situation.
Small punch creep testing: Review on modelling and data interpretation
Authors: Rouse J P , Cortellino F , Sun W , Hyde T H , Shingledecker J
Published: October 2013

In many situations where the characterisation of the mechanical behaviour of a specific material is required, source material for manufacture of conventional test specimens may be at a premium. Examples include the validation of new alloys for use in the power industry, the description of the heat affected zone (HAZ) of weldments 1 or performing a remnant life study on an in service component (such as steam pipe work used extensively in the power generation industry). The potential for a limit in sample material has necessitated the development of small specimen designs and associated test methods, particularly for the determination of the creep behaviour of a sample material. The small punch creep test (SPCT) has the potential to characterise the full uniaxial creep curve (as the specimen is taken to fracture). It is for this reason that the small punch creep test has attracted much interest from the research community. Owing to the complex deformation mechanism interactions experienced in the small punch creep test, interpretation of the results has received attention from many authors since its application was proposed by Parker et al. in the 1990s 2 (based on small punch plasticity test by Manahan et al. in the 1980s 3 – 5 ). In this review paper, several methods for the interpretation of small punch creep test (SPCT) data are reported and compared, together with examples of their application. Considerations for finite element (FE) modelling of small punch creep tests are highlighted and critiqued. Recommendations for potential areas of future research are also presented based on the authors’ investigation into published literature and research.
Study on squeeze casting of an in situ 5 vol.- TiB2/2014 Al composite
Authors: Xue J , Han Y F , Wang J , Sun B D
Published: October 2013

An in situ 5 vol.- TiB2/2014 composite was prepared by an exothermic reaction of K2TiF6, KBF4 and Al melts. The effect of introduction of in situ formed TiB2 particles on the squeeze-casting formability of the composite was discussed. The microstructural evolution and changes in the mechanical properties of the composite at different squeeze pressures were investigated. The results showed that a pouring temperature of 710°C, a die temperature of 200°C and a squeeze pressure of 90 MPa were found to be sufficient to get the qualified squeeze cast and maximum mechanical properties for an Al 2014 alloy. However, the pouring temperature, die temperature and squeeze pressure need to be increased to 780°C, 250°C and 120 MPa for the composite to get the qualified squeeze cast and maximum mechanical properties as a result of the effect of introduction of in situ formed TiB2 particles on the solidification process, plasticity and fluidity of the composite. The microstructural refinement, elimination of casting defects such as shrinkage porosities and gas porosities and improved distribution of TiB2 particles in the case of the composite result when pressure was applied during solidification. Compared with the gravity-cast composite, the tensile strength, yield strength and elongation of the squeeze-cast composite at 120 MPa increased by 21, 16 and 200.
Partial transformation of austenite in Al–Mn–Si TRIP steel upon tensile straining: An in situ EBSD study
Authors: Lomholt T N , Adachi Y , Bastos A , Pantleon K , Somers M A J
Published: October 2013

The transformation of austenite to martensite in an Al–Mn–Si transformation-induced plasticity steel was investigated with in situ electron backscatter diffraction (EBSD) measurements under tensile straining. The visualisation of the microstructure upon straining allows for an investigation of the stability of austenite grains against strain-induced transformation, with particular focus on the grain size and the location of the austenite grains. The findings confirm that size and location of austenite grains are significant parameters for their stability. Small austenite grains were observed to be more stable than large grains, while austenite grains located beside bainitic ferrite are the most stable. Moreover, it is demonstrated that austenite grains transform gradually.
Effect of creep deformation on Z phase formation in Gr.91 steel
Authors: Sawada K. , Kushima H. , Tabuchi M. , Kimura K.
Published: October 2013

In order to make clear the effect of creep deformation on Z phase formation in Gr.91 steel, creep interrupted tests were performed for 10 000, 20 000, 30 000, 50 000 and 70 000 h at 600°C under 70 MPa. The time to rupture was 80 736·8 h at 600°C under 70 MPa. Z phase was observed in the vicinity of prior austenite grain boundaries in the grip and gauge portions after creep deformation for 10 000 h and more. Number density of Z phase particles increased with increasing creep time in the grip and gauge portions. The number densities of MX carbonitrides particles in the grip and gauge portions clearly started to decrease after 30 000 h corresponding to increase in number density of Z phase. In the gauge portion, the number density of MX carbonitrides particles was almost the same as that of Z phase particles after creep rupture, meaning that a large number of MX carbonitrides particles were disappeared. The number density of Z phase particles in the gauge portion was 2·5 times of that in the grip portion after creep rupture. This indicates that creep deformation promotes the Z phase formation.