bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Drivetime – Performing Non-Driving Related Tasks While Driving Highly Automated
Authors: Gold Christian , Berisha Ilirjan , Bengler Klaus
Published: October 2015

To utilize drivetime by engaging in non-driving related (secondary) tasks while driving highly automated is very likely to occur as soon as Level 3 (see NHTSA, 2013) automated vehicles enter the market. For this reason, it has to be investigated in advance whether different tasks are impeding drivers’ capabilities of regaining control in take-over situations and thereby compromising safety. For this purpose, studies regarding take-over in highly automated vehicles were reviewed and an experiment in a high fidelity driving simulator involving 24 participants was conducted, comparing four different types of non-driving related tasks. Results show differences in the dependent variables, dependent on criticality and complexity of the situation. Compared to drivers with visual and motoric tasks, take-over performance of drivers with a cognitive task was superior in well-practiced and noncomplex situations. Although the take-over situations of this study were well practiced and complexity and time criticality of the take-over situations were rather low, drivers reacted faster in manual mode than under the presence of the automated system. Furthermore, the participants reported engaging in those tasks as being rather dangerous and impeding their take-over performance and capability of reaction.
Distraction Becomes Engagement in Automated Driving
Authors: Miller David , Sun Annabel , Johns Mishel , Ive Hillary , Sirkin David , Aich Sudipto , Ju Wendy
Published: October 2015

As vehicle automation proliferates, the current emphasis on preventing driver distraction needs to transition to maintaining driver availability. During automated driving, vehicle operators are likely to use brought-in devices to access entertainment and information. Do these media devices need to be controlled by the vehicle in order to manage driver attention? In a driving simulation study ( N=48) investigating driver performance shortly after transitions from automated to human control, we found that participants watching videos or reading on a tablet were far less likely (6% versus 27%) to exhibit behaviors indicative of drowsiness than when overseeing the automated driving system; irrespective of the pre-driving activity, post- transition driving performance after a five-second structured handoff was not impaired. There was not a significant difference in collision avoidance reaction time or minimum headway distance between supervision and media consumption conditions, irrespective of whether messages were presented on the tablet device, or only presented on the instrument panel, or whether there was a single or two-stage handoff.
The Effects of a Scheduled Driver Engagement Strategy in Automated Driving
Authors: Blommer Mike , Curry Reates , Kochhar Dev , Swaminathan Rads , Talamonti Walter , Tijerina Louis
Published: October 2015

This simulator study investigated a driver engagement (DE) strategy designed to keep the driver-in-the-loop during automated driving in the face of two different types of secondary tasks. The method, first reported by Carsten et al. (2012), involved driving in fully automated driving mode for 6 minutes followed by 1 minute of manual driving, after which this fixed schedule was repeated several times throughout the drive. This scheduled strategy was compared to a reference condition in which different participants experienced continuous automated driving without interruptions. For each condition, some participants watched a video and others listened to the radio. All drives ended in automated driving mode with a surprise forward collision (FC) hazard to which the participant had to manually intervene. Compared to video watchers, r adio listeners responded faster, looked to the road scene more, and they were more often looking forward at FC event onset. The DE strategy had no effect on radio listeners. In contrast, video watchers responded to the hazard more quickly with the scheduled strategy than without it. However, there was no reliable statistical difference between DE conditions in percent-eye-glance-time looking to the forward road scene during automated driving or in the number of drivers looking forward at FC event onset. Thus, the scheduled driver engagement strategy appears beneficial in the face of the visual ( video) secondary task, but the reasons for this advantage remain to be determined.
Electroluminescent Materials Can Improve Nighttime Pedestrian Conspicuity When Added to Retroreflective Garments
Authors: Fekety Drea K. , Edewaard Darlene , Sewall Ashley Stafford , Adams Stanton , Ormson T.Keanau , Eddy Brian , Moore Peyton , Tyrrell Richard A.
Published: October 2015

Retroreflective materials make nighttime pedestrians more conspicuous to drivers, especially when configured in a biological motion pattern. Because retroreflectors are only effective when they are illuminated by a light source near the driver, they are not useful for pedestrians who are positioned outside the beam of a vehicle’s headlamps. Electroluminescent materials have the potential to enhance conspicuity in these conditions. We investigated the conspicuity benefits of adding electroluminescent material to clothing containing retroreflectors. We compared, using an open-road course at night, the distances at which 120 observers responded to a test pedestrian wearing one of two garments at one of three roadside locations. Response distances to the garment that contained both electroluminescent and retroreflective materials were significantly longer, particularly when the pedestrian was more poorly illuminated as a result of being positioned on the left shoulder. These findings suggest electroluminescent materials have the potential to enhance the conspicuity of pedestrians.
Psychological Response not Physiological Response Predicts Aggression behind the Wheel during Cold Stress
Authors: Morris Drew M , Pilcher June J
Published: October 2015

Cold environments alter human behavior and limit performance through cold stress. Driving is commonly performed during cold winter months when vehicle cabin temperatures induce short-term cold stress. Skin temperature was experimentally manipulated to study the impact of cold stress on driving behavior. Forty-four participants drove a high-fidelity driving simulator during a thermal neutral or cooled condition. Results showed that participants who had higher subjective ratings of cold followed lead vehicles closer and applied brakes harder. Participants in the cold condition followed the lead car 22% (0.82 seconds) closer and applied the brakes 7% harder when presented with a stop sign during a following task. This behavior was predicted by subjective sensation and not by physiological response to cold. The current results suggest that drivers exposed to cold environmental conditions are more likely to display aggressive driving behavior.
Micro interactions and Multi dimensional Graphical User Interfaces in the Design of Wrist Worn Wearables
Authors: Motti Vivian Genaro , Caine Kelly
Published: October 2015

Advances in technology in the past decades, including miniaturized components, flexible materials and novel sensors, fostered advances in Wearable Computing. With many different form factors available and diverse potential features, wearable computers have been successfully applied in various domains. Despite the large potential and versatility of wearable devices, and wrist worn computers in particular, it is still a major challenge to design efficiently their user interfaces and interactive solutions. The design of efficient interaction solutions is complex due to the dynamic constraints and requirements of the contexts of use where the user interaction takes place and also due to inherent limitations of wearable devices, which involve processing, power, and interactive surfaces. This paper presents the main challenges in the design of interaction and interfaces for wrist worn wearables, and to address a major requirement in this domain, of quick interactions through small displays, it also discusses two interaction paradigms in a design approach for wrist worn devices, integrating micro interactions and multi dimensional graphical user interfaces.
Combined use of Cognitive Task Analysis and Observational Research Data to Identify Deficiencies of Support for Situation Awareness
Authors: van Doorn Ellemieke , Horváth Imre , Rusák Zoltán
Published: October 2015

Designers require insight into deficiencies of current support for situation awareness (SA) to be able to improve operators’ SA through better system design. The current methods proposed in literature to gain insight into sources of SA errors are not suitable to identify deficiencies in the field of nautical operational network management. This paper proposes a structured approach for syntactic and semantic processing of cognitive task analysis (CTA) data and observational research data to identify deficiencies. The results show that analysis of CTA data and observational research data complement each other and are best used in parallel.
Assessing the Situation Awareness of Operators Using Maritime Augmented Reality System (MARS)
Authors: Hong Teo Chee , Andrew Ho Si Yong , Kenny Chua Wei Liang
Published: October 2015

Operators controlling vehicles remotely are required to perceive and process information from several sources such as video feeds, maps and radar. These sources of information are often located on different screens and in order to make informed decisions, they require good Situation Awareness (SA) and the ability to locate information easily. To reduce the frequency of instrument scanning, it is proposed that information from other sources such as maps and radar can be co-located on the same screen using Augmented Reality (AR). In Maritime Augmented Reality System (MARS) interface, information from the Automatic Identification System for vessels in the maritime environment is augmented on the video feed so that operators can have ready access to vessel location and heading while navigating. Experiments were carried out to assess the SA and workload of the operator using evaluation methods such as SAGAT and SART. Results suggest that by providing additional information through the use of AR, SA of the operator improved even though there might be a suggestion of an increase in workload.
Communication Between Human Factors Psychologists and Engineers
Authors: Stowers Kimberly
Published: October 2015

Human factors psychology has evolved as a field to include research that reaches across many disciplines, including engineering, medicine, and education. This interdisciplinary work can be accompanied by barriers to communication between human factors psychologists and other professionals. This paper addresses challenges in communication between human factors psychologists and engineers as they work together on interdisciplinary projects. The primary purpose of this paper is therefore to examine these challenges and propose possible solutions that may aid in communication. This paper secondarily serves as a call for dialogue and research examining interdisciplinary communication in human factors.
Air Force Human Systems Integration – Capabilities and Requirements Tool
Authors: Patel Arpan , Cooks Andrea , Cosing Sheryl , Cybenko Anne , Kosnik William D. , Plaga John A. , Shihady Jessica
Published: October 2015

Establishing human-centered requirements early in the system design, development and acquisition process is key to delivering effective and useable systems to the warfighter. To achieve this goal, it would be beneficial for the HSI practitioner to have a standardized, data-driven tool to assist in generating, tracking, and documenting human-centered requirements. The Survivability/Vulnerability Information Analysis Center created the Human Systems Integration – Capabilities and Requirements Tool in order to provide a means for identifying human related risks and concerns. The HSI-CRT uses domain-based questions to analyze human related risks in Capabilities-Based Assessment, Analysis of Alternatives, and Concept Development. The questions were developed by leveraging Department of Defense and Air Force requirements guides for these three processes. HSI-CRT is based on a risk management approach that is familiar to system engineering and program management disciplines. The practitioner responds to a set of questions with simple yes/no answers that query the status of human centered risks at any point in the requirements planning process. The practitioner is then prompted to rate the potential human performance risk using the standard DoD risk methodology. The tool also allows the practitioner to document the HSI status by entering data that supports the risk rating. Based on user responses, the HSI-CRT provides a report documenting the human performance risks associated with the analysis being performed. The tool was released to the Air Force in July 2015.
The Bad Touch
Authors: Dorton Stephen , Samaroo Laura
Published: October 2015

The number of extraneous touches, or number of user touches on a Touch Screen Display (TSD) that were in excess of the minimum required to perform a procedural task, was investigated as an implicit usability metric during a usability study. Data for this pilot study were obtained from a usability assessment performed to evaluate old and new versions of a TSD for adjusting system configuration settings on a system for the US Navy. Participants ( N = 28) performed a training mission on a gunnery trainer, during which they engaged simulated enemy boats while being interrupted to perform procedural tasks on a TSD at regular intervals. The count of extraneous touches was significantly correlated with task completion time and System Usability Scale (SUS) scores, providing notional support for its use as a usability metric. The advantages of this metric and limitations of these findings are discussed.
A Micro-Task Method for Assessing Performance Effects of Innovative Interface Elements
Authors: Hildebrandt Michael , Eitrheim Maren Helene Rø
Published: October 2015

This paper describes a data collection method for obtaining high volumes of performance data from a short testing session. The method is aimed at documenting the performance benefits and drawbacks of innovative interface features in terms of identification times and error rate on a component and system level. Higher-level aspects of control room operation, such as teamwork, communication, context and situation awareness, are not currently within the scope of this method (we consider this methodology as one element of a larger evaluation process where these higher-level aspects are tested separately). The benefits of this methodology are economy of data collection (amount of data points per unit of time), economy of analysis, objectivity of measures, and clarity of results.
Observer Perceptions of Overall System Quality – the Lake Wobegon Effect
Authors: Smith Thomas J.
Published: October 2015

Objective: For three different system categories—fabricated artifacts, built environments, and software interfaces, to compare and contrast observer rankings of the overall quality of a selected topic or artifact pertaining to that category, relative to rankings of the quality of different specific attributes of the same topic. Method: A paired samples t-test was applied to ascertain the degree of statistical similarity between the overall quality rankings, and the average specific attribute quality rankings. Result: For each of the three system categories, the grouped average for overall quality rankings is higher than the grouped average for averaged specific attribute quality rankings. Conclusion: Two alternative interpretations of the results are offered, informed by either Gestalt psychology or by neurobiological reference to cognitive versus affective decision-making. Understanding of the basis of the findings will require further research. Application: Usability analysis assumes that evaluating the quality of specific attributes of a selected design will predict overall design quality. It can be argued that findings reported here call into question widely accepted assumptions about the general utility of usability analysis.
Guidelines and Caveats for Manipulating Expectancies in Experiments Involving Human Participants
Authors: Minotra Dev , Burns Catherine M. , McNeese Michael D.
Published: October 2015

In a number of domains involving decision making under high time pressure, the appearance of an unexpected critical event can startle operators causing errors that may potentially lead to a chain reaction of unfavorable events. Simulating such situations in a laboratory requires overcoming several challenges tied to human responses to unexpected and rare critical events. We discuss cases of experimental studies that have incorporated simulations, critical events, interruptions, predictive displays and ecological displays involving naïve and expert participants. We spell out guidelines and caveats pertaining to training, expertise, temporal variables, critical event frequencies, scenario design, mediator and moderator variables to name a few. The guidelines and caveats may inform researchers in the design of generalizable and reproducible experiments and in the analysis of data.
Experimental Evaluation of Indoor Navigation Devices
Authors: Rehman Umair , Cao Shi
Published: October 2015

Augmented reality (AR) interfaces for indoor navigation on handheld mobile devices seem to greatly enhance directional assistance and user engagement, but it is sometimes challenging for users to hold the device at specific position and orientation during navigation. Previous studies have not adequately explored wearable devices in this context. In the current study, we developed a prototype AR indoor navigation application in order to evaluate and compare handheld devices and wearable devices such as Google Glass, in terms of performance, workload, and perceived usability. The results showed that although the wearable device was perceived to have better accuracy, its overall navigation performance and workload were still similar to a handheld device. We also found that digital navigation aids were better than paper maps in terms of shorter task completion time and lower workload, but digital navigation aids also resulted in worse route/map retention.
Relationship between smartphone use and the severity of head flexion of college students
Authors: Lee Sojeong , Shin Gwanseob
Published: October 2015

Frequent and prolonged head forward flexion posture of smartphone users has been considered as a key risk factor for various pain symptoms or musculoskeletal problems of the neck and neighboring areas. Although smartphone users are known to make large head flexion to look down the smartphone while holding the phone with their hands, it has not yet been studied whether the duration of smartphone use and the severity of head flexion angle would linearly related or not. In this study, the correlation between the total duration of smartphone use and the severity of head flexion was quantitatively evaluated from the unobtrusively collected head flexion angle data and smartphone usage history data of 22 participants. In results, it was found that participants spent more than 2 hours (out of 8-hour period) with their smartphone and more than 90 minutes with the head flexed between 30 and 50 degrees. Correlation coefficient between the two variable was 0.293. While the result of this study indicates relatively weak correlation between the two, it still suggests that heavy smartphone users would make the large head flexion longer than light smartphone users. Further research with more samples of various occupations and smartphone usage patterns would strengthen the findings of this study.
A Comparison Between WarnGen System and Probabilistic Hazard Information System for Severe Weather Forecasting
Authors: Ling Chen , Hua Lesheng , Karstens Christopher D. , Stumpf Gregory J. , Smith Travis M. , Kuhlman Kristin M. , Rothfusz Lans
Published: October 2015

To increase the nation’s preparedness for severe weather, it is important to design effective ways to communicate severe weather information. This study reports an experiment conducted in the 2014 Hazardous Weather Testbed (HWT) comparing the deterministic severe weather warning system WarnGen, and a prototype Probabilistic Hazard Information (PHI) system. Six National Weather Service (NWS) forecasters used both systems to forecast severe hail events. With minimal training, the PHI system received similar levels of system usability and weather situation awareness rating as the WarnGen system. Meanwhile, the PHI system resulted in significantly less temporal stress for the forecaster and all forecasters preferred the prototype PHI system to the WarnGen system. Forecasters believed the PHI system allowed them to convey richer and better weather information to the public, which could result in better service overall.
Model-Based Pilot Training Syllabus
Authors: Rister Frank , Osterloh Jan-Patrick , Lüdtke Andreas , Specht Paul
Published: October 2015

Technical progress takes place rapidly in every industry and so it does in aviation. Nowadays formerly acquired flying skills of a pilot doing transition training from one aircraft to another are completely ignored. Thus, the trainee is faced with a lot of training on already existing knowledge, without being properly advised to the fine differences and specific characteristics of the new aircraft. Our idea for solving this deficit is a tool that compares the knowledge a pilot already has to the knowledge needed for the new aircraft type. To do so, we modeled the whole set of tasks for flying an aircraft, down to the lowest level of key-strokes, for the different aircraft types. Based on the models, our algorithm finds the differences in the task models and creates syllabi which properly incur to the sticking points of these differences and allow recognizing what kind of learning transfers will occur.
Hand Videos in Virtual Collaboration for Map-Based Planning Activities
Authors: Cheng Xuan , Hayes Caroline
Published: October 2015

The tools studied in this work are map-based virtual environments that help people at different locations to solve map-based tasks together. The goal of this work is to evaluate the question: does adding real-time videos of the hands and arms of virtual collaborators to a map-based virtual environment help people to be more effective than simpler technologies (e.g. drawing on an electronic map, or telephone only)? Real-time videos of the participants’ hands, when overlaid on a shared electronic map, allow them to use their hands to indicate a route by tracing it with a finger, or draw attention to a location of interest. This information can also be conveyed via simpler and less expensive technologies, such as electronically drawing on a shared map, or verbally describing the route via telephone, but are equally effective? The answer to this question will help developers of virtual collaboration tools to assess whether it is worth the extra effort to include such features in their software.
Mitigating Visually Induced Motion Sickness
Authors: Curtis Michael K , Dawson Kayla , Jackson Kelli , Litwin Liat , Meusel Chase , Dorneich Michael C. , Gilbert Stephen B. , Kelly Jonathan , Stone Richard , Winer Eliot
Published: October 2015

Virtual reality has grown rapidly over the past decade, yet visually induced motion sickness (VIMS), continues to affect the usability of this technology. Aside from medicine, physical hand-eye-coordination tasks have been found to be effective in mitigating symptoms of VIMS, however the need for equipment outside of virtual reality limits the usefulness of these mitigation techniques. In this study, 21 participants were sickened via a virtual obstacle course and used one of two mitigation techniques. The first, natural decay, is simply waiting outside the virtual environment (VE) for symptoms to subside; the other was a virtual peg-in-hole task, performed in the VE with a gamepad. A paired samples t-test confirmed that the virtual obstacle course induced VIMS. Both mitigation techniques significantly lessened the symptoms of VIMS, but there were no significant differences in the effectiveness of mitigation between the two techniques. A virtual mitigation method allowing continued immersion in a VE would pave the way for long-term immersion virtual reality studies, involving topics such as vigilance or training.
Developing a Low-Cost, Portable Virtual Environment for Aircraft Carrier Launch Officers
Authors: Korzatkowski Jeffrey , Kolsch Mathias , Sciarini Lee W.
Published: October 2015

The primary purpose of a United States aircraft carrier is to transport its embarked air wing in order to project combat power through the launch and recovery of various aircraft. In order to get airborne, the air wing depends upon the skills of a small number of officers responsible for the safe and rapid launch of aircraft from the carrier deck. These officers, known as “shooters”, receive initial classroom training on the systems they use then receive qualification to be launch officers through on-the-job training. Due to scheduling complexities the training to achieve qualification is disjointed and often requires trainees to go underway with different aircraft carriers to complete their training. The current approach results in burdens on the parent command, host commands, and the trainees. Of greater concern is the lack of consistency in the training of such a high risk activity. This paper describes the results of a job task analysis conducted to provide insights into the skills required to perform the duties of a launch officer. Further, the information from the job task analysis was examined and a representative finite state machine was developed and is presented. Finally, a portable, low-cost virtual environment created based on the work described above is discussed. It is proposed that the current virtual reality system used for this demonstration faithfully recreates the required attributes and scenarios to train launch officer tasks and that the prototype system, with proof of training transfer can reduce the burden on commands, trainees, and perhaps most importantly, provide consistent training.
Assessing Mental Rotation Ability in a Virtual Environment with an Oculus Rift
Authors: Foroughi Cyrus K. , Wren W. Chris , Barragán Daniela , Mead Patrick R. , Boehm-Davis Deborah A.
Published: October 2015

Many studies have found gender differences in mental rotation ability in young adults when completing mental rotation tests on paper and pencil (e.g., Peters et al., 1995; Vandenberg & Kuse, 1978). Two previous studies have been unable to replicate these findings when testing mental rotation ability inside of a virtual environment (Parsons et al., 2004; Rizzo et al., 2001). We created a new virtual mental rotation test (VMRT) based on a full, validated test of mental rotation ability (MRT-A; Peters et al., 1995) that 128 participants (79 females) completed while wearing an Oculus Rift DK1. Our data replicate previous findings of paper and pencil tests of mental rotation ability: men scored approximately one standard deviation higher ( d = .90) than women.
Investigation of Videogame Flow
Authors: Gascon Jolie G. , Doherty Shawn M. , Liu Dahai
Published: October 2015

The current study sought to investigate an empirical exploration of the flow engagement concept through videogame play between experts and novices. Eighty participants engaged in various levels of the videogame Super Mario Bros. Twenty experts and twenty novices experienced the easier level of World 1-2 while the other twenty experts and novices were exposed to the more difficult level World 6-1. After gameplay, participants completed a modified survey measuring flow. This survey, along with overall percentage game score, was analyzed. A significant interaction was found between game level (challenge level) and skill levels in perceived flow, with significant main effects for expertise in perceived skill, for game level (challenge level) in perceived challenge, and for game level (challenge level) in overall percentage score. These findings are relevant for understanding videogame flow in videogames of varying degrees of challenge and in players of different expertise levels. Discussion on these findings highlights the purpose of this paper.
Feedback Source Modality Effects in Game-Based Training
Authors: Goldberg Benjamin
Published: October 2015

In this paper we explore available tools for integrating intelligent tutoring communications in game-based learning platforms and examine theory-based techniques for delivering explicit feedback in such environments. The primary tool influencing the design of this research is the open-source Generalized Intelligent Framework for Tutoring (GIFT), a modular domain-independent architecture that provides the tools to author, deliver, and evaluate intelligent tutoring technologies. Influenced by social cognitive theory and cognitive load theory based research, the resulting experiment looks at varying approaches for using an Embodied Pedagogical Agent (EPA) defined as a tutor in a game-based training environment. Treatments were authored to examine tradeoffs between embedding an EPA directly in a game, embedding an EPA in GIFT’s browser-based Tutor-User Interface (TUI), or using audio prompts alone with no social grounding. A condition effectiveness evaluation is presented examining treatment effects on performance, reported mental demand, and perceived usefulness of feedback. Outcomes support the use of an EPA present in GIFT’s TUI when compared to effectiveness scores on audio prompts alone and the game embedded EPA.
Does Poststroke Lower-Limb Spasticity Influence the Recovery of Standing Balance Control? A 2-Year Multilevel Growth Model
Authors: Singer Jonathan C. , Nishihara Kanako , Mochizuki George
Published: October 2015

Background. Poststroke lower-limb spasticity (LLS) has been shown to degrade standing balance control by disrupting the temporal synchronization between individual limb centers of pressure (COPs). Time-varying changes in standing balance control associated with alterations in the extent of LLS have yet to be documented and are important to informing treatment strategies to improve such functional outcomes. Objective. The present work aimed to understand the natural recovery of standing balance control among stroke survivors with LLS using limb-specific indices of standing balance control. Furthermore, we sought to understand if time-varying changes in LLS were associated with alterations in standing balance control. Methods. A retrospective analysis of 92 participants was performed; 47 participants never exhibited LLS during the study (No_LLS), and 45 participants exhibited LLS during at least 1 testing session (LLS). Quiet standing for a duration of 30 s on 2 force platforms was recorded. Temporal synchrony and spatial symmetry of COP displacements were assessed, along with interlimb weight-bearing symmetry. Results. All variables, except spatial symmetry, indicated initial improvement followed by deceleration in the rate of balance control recovery. Limb-specific measures indicated that individuals with LLS exhibited deficits in balance control. The recovery trajectories were not different between groups, suggesting a similar rate, but reduced extent, of balance control recovery among the LLS relative to the No_LLS group. Only temporal synchrony was altered by time-varying changes in spasticity. Conclusions. The present results suggest that the reduction in spasticity may be beneficial to balance control recovery.
Utility of Indocyanine Green Fluorescence Imaging for Intraoperative Localization in Reoperative Parathyroid Surgery
Authors: Sound Sara , Okoh Alexis , Yigitbas Hakan , Yazici Pinar , Berber Eren
Published: October 2015

Background. Due to the variations in anatomic location, the identification of parathyroid glands may be challenging. Although there have been advances in preoperative imaging modalities, there is still a need for an accurate intraoperative guidance. Indocyanine green (ICG) is a new agent that has been used for intraoperative fluorescence imaging in a number of general surgical procedures. Its utility for parathyroid localization in humans has not been reported in the literature. Results. We report 3 patients who underwent reoperative neck surgery for primary hyperparathyroidism. Using a video-assisted technique with intraoperative ICG fluorescence imaging, the parathyroid glands were recognized and removed successfully in all cases. Surrounding soft tissue structures remained nonfluorescent, and could be distinguished from the parathyroid glands. Conclusions. This report suggests a potential utility of ICG imaging in intraoperative localization of parathyroid glands in reoperative neck surgery. Future work is necessary to assess its benefit for first-time parathyroid surgery.
CT-guided percutaneous skull biopsy using a drill-assisted system: Technical report of two cases
Authors: Wallace Adam N , Tomasian Anderanik , Hsi Andy C , Chang Randy O , Jennings Jack W
Published: October 2015

The OnControl coaxial biopsy system (Vidacare Corporation, Shavano Park, TX) includes an inner diamond-tipped access needle and hollow biopsy needle that engage with a battery-powered hand drill. Herein, we report the use of this novel device to perform two CT-guided percutaneous skull biopsies. Both procedures were performed without complication and facilitated a pathologic diagnosis.
Endovascular glue embolization of dissecting aneurysm of type-3 accessory middle cerebral artery: A contralateral approach
Authors: Parthasarathy Rajsrinivas , Goel Gaurav , Gupta Vipul , Narang Karanjit Singh , Anand Saurabh , Jha Ajaya Nand
Published: October 2015

Pediatric intracranial aneurysms are rare with a reported prevalence of 0.5–4.6%. Likewise, anomalous arterial patterns are uncommon in the cerebral circulation. Recognition of these variations and knowledge of vascular territory forms the key to managing pathological conditions associated with these anomalous vessels. Ruptured dissecting aneurysm of type-3 accessory middle cerebral artery (aMCA) has not been reported in the pediatric age group. In addition to type-3 aMCA, the child in this case report had an ipsilateral type-1 aMCA with cortical supply. We describe the patterns of accessory MCA and their vascular territory, state the perplexity involved in deciding the best management strategy, and describe the technical approach we undertook to catheterize this small caliber recurrent artery (type-3 aMCA) originating at an acute angle from the anterior cerebral artery.
Fabrication and characterization of ultraviolet photodetectors based on silicon nitride nanostructures prepared by magnetron sputtering
Authors: Hammadi Oday A , Khalaf Mohammad K , Kadhim Firas J
Published: October 2015

In this work, ultraviolet photodetectors have been fabricated by depositing silicon nitride nanoparticles on a p-type silicon substrate by closed-field unbalanced dual magnetron sputtering technique. The structural characteristics of silicon nitride have been identified through X-ray diffraction and scanning electron microscopy. Ultraviolet–visible transmission and absorption spectra of the silicon nitride thin films have been recorded. The maximum spectral responsivities of these photodetectors have been measured. The results show that these photodetectors have quantum efficiencies between 0.421 and 0.479 and specific detectivity up to 2.33 × 1011 cm W−1 Hz−1 at 10 kHz. Accordingly, silicon nitride can be considered as an applicable candidate for ultraviolet photodetectors.
Labour market developments and their significance for VET in Germany: An overview
Authors: Ebner Christian
Published: October 2015

The German labour market has seen substantial structural changes, especially over the past decades: there has been a major shift in labour market policy, the service industry is booming and skills requirements have changed dramatically. This article discusses these trends, offering an empirical analysis of the extent to which the German dual VET system is prepared to meet them. For this purpose, the article explores representative data for Germany and looks at the labour market integration of dual VET graduates. The basic assumption is that a mismatch between the dual VET system and the labour market will also become evident at the micro level of individuals. The results show that dual VET graduates enjoy far better protection against unemployment than people without a vocational training qualification. Likewise, they are far less likely to work in temporary employment. The dual VET system thus functions as a ‘safety net’. At the same time, however, the earnings of dual VET graduates are markedly lower than those of higher education graduates. The article concludes by discussing some of the future challenges and opportunities facing the dual VET system.
The ‘academization’ of the German qualification system: Recent developments in the relationships between vocational training and higher education in Germany
Authors: Wolter Andrä , Kerst Christian
Published: October 2015

The traditional German model of skill formation was based on the rather strict segmentation between vocational training and higher education. However, during recent years this differentiation has slowly dissolved, partly by politically motivated developments to increase the permeability between both sectors and partly as a result of latent changes in the participation in higher education leading to a higher degree of ‘academization’. After a short description and analysis of recent trends in higher education and vocational training, especially the expansion of higher education, the article focuses on two processes to achieve more permeability and cooperation between both parts of the German qualification system: (1) the introduction and extending of dual study programmes and (2) the opening of access to higher education for vocational qualified people without the usual school credentials (e.g. the Abitur). The article concludes with two scenarios regarding trends in the participation in higher education.
Use of Expressed Breast Milk With the Ketogenic Diet
Authors: Fenton Cagla , Randall Rebecca , Groveman Sue A. , Chee Claire M. , Bergqvist A. G. Christina
Published: October 2015

Breastfeeding continues to be the recommended mode of infant feeding with numerous nutritive and nonnutritive benefits to both mothers and babies. The ketogenic diet (KD) is a high-fat, adequate protein, and very low carbohydrate diet prescribed for infants and children with treatment-resistant epilepsy. Due to the high carbohydrate content of breast milk (BM) and the extremely low carbohydrate allowance of the KD, these 2 modes of feeding are typically not used together. We report our experience to demonstrate that BM can be part of a successful KD treatment. A retrospective chart review was performed and 4 patients met criteria. They were younger than 2 years and were fed BM before KD initiation. All achieved ketosis at low (2-3:1) ratios and remained ketotic while using BM. The average amount of BM consumed was 139 ± 50 mL/day, equivalent to 11 ± 4.5 grams of carbohydrates per day. Three patients achieved >50% reduction in seizure frequency within 2 months of treatment. Patients continued using BM for an average of 105 ± 50 days. For all cases, BM was discontinued due to maternal preference. BM is a viable, preferred, carbohydrate source for infants prescribed the KD.
Mandibular Cartilage Collagen Network Nanostructure
Authors: Vanden Berg-Foels Wendy S.
Published: October 2015

Background

Mandibular condyle cartilage (MCC) has a unique structure among articular cartilages; however, little is known about its nanoscale collagen network architecture, hampering design of regeneration therapies and rigorous evaluation of regeneration experiment outcomes in preclinical research. Helium ion microscopy is a novel technology with a long depth of field that is uniquely suited to imaging open 3D collagen networks at multiple scales without obscuring conductive coatings.

Objective

The objective of this research was to image, at the micro- and nanoscales, the depth-dependent MCC collagen network architecture.

Design

MCC was collected from New Zealand white rabbits. Images of MCC zones were acquired using helium ion, transmission electron, and light microscopy. Network fibril and canal diameters were measured.

Results

For the first time, the MCC was visualized as a 3D collagen fibril structure at the nanoscale, the length scale of network assembly. Fibril diameters ranged from 7 to 110 nm and varied by zone. The articular surface was composed of a fine mesh that was woven through thin layers of larger fibrils. The fibrous zone was composed of approximately orthogonal lamellae of aligned fibrils. Fibrocyte processes surrounded collagen bundles forming extracellular compartments. The proliferative, mature, and hypertrophic zones were composed of a branched network that was progressively remodeled to accommodate chondrocyte hypertrophy. Osteoid fibrils were woven around osteoblast cytoplasmic processes to create numerous canals similar in size to canaliculi of mature bone.

Conclusion

This multiscale investigation advances our foundational understanding of the complex, layered 3D architecture of the MCC collagen network.
A Novel Cross-Linked Hyaluronic Acid Porous Scaffold for Cartilage Repair
Authors: Bauer Christoph , Berger Manuela , Baumgartner Renate R. , Höller Sonja , Zwickl Hannes , Niculescu-Morzsa Eugenia , Halbwirth Florian , Nehrer Stefan
Published: October 2015

Purpose

An important feature of biomaterials used in cartilage regeneration is their influence on the establishment and stabilization of a chondrocytic phenotype of embedded cells. The purpose of this study was to examine the effects of a porous 3-dimensional scaffold made of cross-linked hyaluronic acid on the expression and synthesis performance of human articular chondrocytes.

Materials and Methods

Osteoarthritic chondrocytes from 5 patients with a mean age of 74 years were passaged twice and cultured within the cross-linked hyaluronic acid scaffolds for 2 weeks. Analyses were performed at 3 different time points. For estimation of cell content within the scaffold, DNA-content (CyQuant cell proliferation assay) was determined. The expression of chondrocyte-specific genes by embedded cells as well as the total amount of sulfated glycosaminoglycans produced during the culture period was analyzed in order to characterize the synthesis performance and differentiation status of the cells.

Results

Cells showed a homogenous distribution within the scaffold. DNA quantification revealed a reduction of the cell number. This might be attributed to loss of cells from the scaffold during media exchange connected with a stop in cell proliferation. Indeed, the expression of cartilage-specific genes and the production of sulfated glycosaminoglycans were increased and the differentiation index was clearly improved.

Conclusions

These results suggest that the attachment of osteoarthritic P2 chondrocytes to the investigated material enhanced the chondrogenic phenotype as well as promoted the retention.
Superficial Zone Extracellular Matrix Extracts Enhance Boundary Lubrication of Self-Assembled Articular Cartilage
Authors: Peng Gordon , McNary Sean M. , Athanasiou Kyriacos A. , Reddi A. Hari
Published: October 2015

Objective

Previous work has shown that increasing the production of boundary lubricant, superficial zone protein (SZP), did not reduce the friction coefficient of self-assembled articular cartilage constructs and was possibly due to poor retention of the lubricant. The aim of this investigation was to reduce the friction coefficient of self-assembled articular cartilage constructs through enhancing SZP retention by the exogenous addition of extracellular matrix (ECM) extracted from the superficial zone of native articular cartilage.

Design

Superficial zone cartilage was shaved from juvenile bovine femoral condyles using a dermatome, minced finely with razor blades, extracted with 4 M guanidine-hydrochloride, buffer exchanged with culture medium, and added directly to the culture medium of self-assembled articular cartilage constructs at low (10 µg/mL) and high (100 µg/mL) concentrations for 4 weeks. Biochemical and biomechanical properties were determined at the conclusion of 4 weeks culture.

Results

ECM treatment increased compressive and tensile stiffness of self-assembled articular cartilage constructs and decreased the friction coefficient. Glycosaminoglycan content decreased and collagen content increased significantly in self-assembled constructs by the ECM treatment.

Conclusions

Friction coefficients of self-assembled articular cartilage constructs were reduced by adding extracted superficial zone ECM into the culture medium of self-assembled articular cartilage constructs.
Bisphosphonate-adsorbed ceramic nanoparticles increase bone formation in an injectable carrier for bone tissue engineering
Authors: Cheng Tegan L , Murphy Ciara M , Ravarian Roya , Dehghani Fariba , Little David G , Schindeler Aaron
Published: October 2015

Sucrose acetate isobutyrate (SAIB) is a sugar-based carrier. We have previously applied SAIB as a minimally invasive system for the co-delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2) and found synergy when co-delivering zoledronic acid (ZA) and hydroxyapatite (HA) nanoparticles. Alternative bioceramics were investigated in a murine SAIB/rhBMP-2 injection model. Neither beta-tricalcium phosphate (TCP) nor Bioglass (BG) 45S5 had a significant effect on bone volume (BV) alone or in combination with the ZA. 14C-labelled ZA binding assays showed particle size and ceramic composition affected binding with nano-HA > micro-HA > TCP > BG. Micro-HA and nano-HA increased BV in a rat model of rhBMP-2/SAIB injection (+278% and +337%), and BV was further increased with ZA–adsorbed micro-HA and nano-HA (+530% and +889%). These data support the use of ZA–adsorbed nanoparticle-sized HA as an optimal additive for the SAIB/rhBMP-2 injectable system for bone tissue engineering.
Acute cholecystitis after urological surgery: A report of 11 cases in our department and a review of the literature
Authors: Yokoyama Hitoshi , Hara Hiroaki , Ogawa Teruyuki , Ishizuka Osamu
Published: October 2015

Objective:

Postoperative acute cholecystitis (PAC) after gastrointestinal surgery is considered to be a relatively common complication. However, PAC after urological surgery is extremely rare.

Patients and methods:

We conducted a retrospective review of 2583 patients who underwent urological surgery in our department from 2006 to 2014 to identify those who developed acute cholecystitis in the postoperative period.

Results:

Of the 2583 patients, 11 (0.4%) were diagnosed with PAC. The study population consisted of 10 (91%) men and one (9%) woman. Among them, five (45%) patients had acalculous cholecystitis. The median interval between the preceding urological surgery and the onset of PAC was 16 days (range, 3–39 days). Emergent cholecystectomy and/or gallbladder drainage was performed in eight (73%) cases. Although four (36%) patients developed septic shock and were treated in the intensive care unit, cholecystitis improved in all cases. One patient died of her underlying disease (adrenal cancer) two months after PAC.

Conclusion:

Most routinely performed urological surgeries can cause PAC. The symptoms of PAC may be masked in the postoperative period. Urologists must be aware of PAC and should not hesitate to perform further inspection and consultation with a gastroenterologist in cases in which it is suspected.