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Computer-mediated communications (CMC) can be used as a substitute for face-to-face (FtF) meetings but their effectiveness is highly context dependent. This paper describes a theoretical framework and initial experimental design for characterizing a travel replacement threshold. This effort begins with a use case of remote engineering maintenance training, conducted in three conditions: side-by-side (physically proximate), teleconference (using off-the-shelf software), and a custom VR/AR system designed to provide the apprentice with a virtual view of both the instructor’s larger scale lab and smaller scale workbench. The research hypotheses, experimental protocol, and dependent measures are described. The task involves an instructor demonstrating a circuit board troubleshooting task to a remote apprentice. The apprentice then completes the trained task independently, and performance and subject preferences are compared across conditions. The details of this paper, the result of extensive literature review and winnowing of variables, may assist researchers exploring CMC, training, or social communication.

Computer-mediated communication (CMC) has become the new normal in the era of pandemic-induced physical distancing. CMC has dramatically reduced business travel and daily commuting for knowledge workers able to work from home, which in turn reduces carbon emissions and energy expenditure. CMC offers a different communication experience compared to in-person interactions, and its impact on the success of communication is complex. Here, we report the Communication Objectives Model (COM), a framework developed to: a) understand differences in the performance of communication objectives between CMC and face-to-face interactions, and b) guide future research on measurement of such communication objectives. Given that effective communication is essentially the result of a team activity, the psychosocial constructs that comprise our framework are derived from team research across multiple domains (e.g., social psychology, human-computer interaction, and computer supported cooperative work). Constructs of interest include trust, rapport, engagement, conflict management, collective efficacy, mental models, and shared situation awareness. For each construct, we provide a definition, empirical evidence, and theoretical bases for its observable behavioral markers, as well as potential measurement methods and analytical techniques. The contributions of this research include a framework for characterizing differences between different communication media, a hypothetical implementation demonstrating how the framework can inform the decision to travel in-person versus to deploy CMC (i.e., a travel replacement threshold), and an inventory of tools and techniques that can be used to measure and assess the psychosocial constructs involved in CMC.

Business travel leads to the consumption of large amounts of energy. Circuit World (CW), a Unity virtual environment, uses avatars and realistic simulations of electrical circuits to test the effectiveness of teaching complex engineering tasks without travel. To evaluate CW, a study compares how well participants learn to repair a circuit when trained face-to-face, via Zoom, and within CW wearing an HMD. After training and completion of a knowledge quiz, learners are given a circuit to repair by themselves using a non-immersive desktop version of CW. Participants repair it again two weeks later to test retention. Each study session involves three people: learner, trainer, and researcher. The learner and trainer control avatars and the researcher, invisible, observes over the learner’s shoulder. Collected data includes task performance logs from CW, knowledge quiz scores, and, based on video recordings, eye gaze tracking, behavioral coding, and measures of facial synchrony between trainer and learner.

This work evaluates the impact of augmented reality (AR) technology to support operators during manual industrial tasks. The work focuses specifically on monitor-based augmented reality as a solution to provide instructions to the operator. Instructions are superimposed directly onto a video representation of the physical workspace and are displayed on a standard monitor. In contrast to previous AR solutions proposed to support manual tasks, the current work is more industrially acceptable because it meets most of the industrial requirements and it is cost effective for a deployment in an industrial environment. The developed prototype is described and evaluated by means of a user study to compare the monitor-based augmented reality solution to provide instructions and the traditional method. The test shows that AR can be a valid substitute to support the operators during manual tasks because it allows them to be more time efficient and it reduces their mental workload compared to traditional instructional manuals.

Reaction of vertebrate serum complement with different Borrelia burgdorferi sensu lato species is used as a basis in determining reservoir hosts among domesticated and wild animals. Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii were tested for their sensitivity to sera of exotic vertebrate species housed in five zoos located in the Czech Republic. We confirmed that different Borrelia species have different sensitivity to host serum. We found that tolerance to Borrelia infection possessed by hosts might differ among individuals of the same genera or species and is not affected by host age or sex. Of all zoo animals included in our study, carnivores demonstrated the highest apparent reservoir competency for Lyme borreliosis spirochetes. We showed that selected exotic ungulate species are tolerant to Borrelia infection. For the first time we showed the high tolerance of Siamese crocodile to Borrelia as compared to the other studied reptile species. While exotic vertebrates present a limited risk to the European human population as reservoirs for the causative agents of Lyme borreliosis, cases of incidental spillover infection could lead to successful replication of the pathogens in a new host, changing the status of selected exotic species and their role in pathogen emergence or maintenance. The question if being tolerant to pathogen means to be a competent reservoir host still needs an answer, simply because the majority of exotic animals might never be exposed to spirochetes in their natural environment.

OBJECTIVES: The objective of this study was to a) determine the feasibility of eating in virtual reality (VR) environment while wearing a head mounted display (HMD) and b) determine the effect of eating in a virtual restaurant on food intake, sensory evaluation of the test food and masticatory parameters. METHODS: Fifteen adults were asked to report to the laboratory on two occasions, separated by at least one week, at their usual lunchtime. On reporting to the laboratory, surface electrodes were attached to the left and right masseter muscles to measure masticatory activity and a wristband placed on the non-dominant wrist to collect physiological data. The participant sat quietly for 5 minutes before a VR (HMD) was placed on their head. The HMD displayed either a virtual restaurant (pizzeria) or a blank scene (consisting of a white background and a table). The participant's hand movements were captured using an infrared camera mounted on the HMD so when the participant moved their hands this was represented by computer generated model hands in the VR scene. The test foods (pizza bites) were represented in VR using a 3D model of pizza bites. The test foods were arranged so that when the participant touched the test food model in the VR scene they touched the test food in real life allowing them to locate and pick up the test food. The participant was instructed to eat the test food until they felt comfortably full. When the participant finished eating the equipment was removed and they completed questionnaires regarding their feelings of presence and experiences in the VR environment and their ratings of the test food attributes. RESULTS: Participants were able to successfully locate and eat the pizza rolls while in the VR environment. The participants feeling of presence was higher in the restaurant scene compared to the blank scene (P

Sperm induction pores, tubuli annulati, rami sacculi, sacculus foemineus, cornu sacculus and acantho-membranous hood in female Dermanyssus gallinae support the probability of coxal insemination as reported for some other mesostigmatid species. Development of the circular testis in males (from fusion of two anterolaterally projecting protonymphal testicular arms) and formation of haploid (n = 3) spermatids from haploid (n = 3) spermatogonial cells is entirely mitotic. Spermatogenesis begins within one hour after protonymphal feeding and continues through adult ecdysis in normally fed individuals. Nutritional deficit causes cessation of spermatogenic divisions in deutonymphs starved 23 days, but is rapidly rejuvenated upon feeding. No rejuvenation of division was observed in adult males given the opportunity to feed, thus adult males might not feed.

Single esophageal and paired cheliceral, palpal, pedal (I-IV), and opisthosomal nerves enter the synganglion and form specific neuropilar ganglia. The ganglia are integrated by a complex series of commissures and connectives. Eighteen paraldehyde-fuchsin-positive neurosecretory regions, which vary greatly in size and amount of granular neurosecretory material, are each associated (one or more) with neuropilar ganglia. Presumably transport of neurosecretory materials to target tissues occurs through axonal pathways, perineurial-neural lamella associations, and the neurohemal retrocerebral organ complex.

The task of locating a source based on the measurements of the signal emitted/emanating from it is called the source-seeking problem. In the past few years, there has been a lot of interest in deploying autonomous platforms for source-seeking. Some of the challenging issues with implementing autonomous source-seeking are the lack of a priori knowledge about the distribution of the emitted signal and presence of noise in both the environment and on-board sensor measurements. This paper proposes a planner for a swarm of robots engaged in seeking an electromagnetic source. The navigation strategy for the planner is based on Particle Swarm Optimization (PSO) which is a population-based stochastic optimization technique. An equivalence is established between particles generated in the traditional PSO technique, and the mobile agents in the swarm. Since the positions of the robots are updated using the PSO algorithm, modifications are required to implement the PSO algorithm on real robots to incorporate collision avoidance strategies. The modifications necessary to implement PSO on mobile robots, and strategies to adapt to real environments are presented in this paper. Our results are also validated on an experimental testbed.

This research investigates different visual features for augmented reality (AR)–based assembly instructions. Since the beginning of AR research, one of its most popular application areas has been manual assembly assistance. A typical AR assembly application indicates the necessary manual assembly operations by generating visual representations of parts that are spatially registered with, and superimposed on, a video representation of the physical product to be assembled. Research in this area indicates the advantages of this type of assembly instruction presentation. This research investigates different types of visual features for different assembly operations. The hypothesis is that in order to gain an advantage from AR, the visual features used to explain a particular assembly operation must correspond to its relative difficulty level. The final goal is to associate different types of visual features to different levels of task complexity. A user study has been conducted in order to compare different v...

Detection of Borrelia burgdorferi sensu stricto in Amblyomma americanum ticks in the southeastern United States: the case of selective compatibility

Many interfaces exist for locomotion in virtual reality, although they are rarely considered fully natural. Past research has found that using such interfaces places cognitive demands on the user, with unnatural actions and concurrent tasks competing for finite cognitive resources. Notably, using semi-natural interfaces leads to poor performance on concurrent tasks requiring spatial working memory. This paper presents an adaptive system designed to track a user's concurrent cognitive task load and adjust interface parameters accordingly, varying the extent to which movement is fully natural. A fuzzy inference system is described and the results of an initial validation study are presented. Users of this adaptive interface demonstrated better performance than users of a baseline interface on several movement metrics, indicating that the adaptive interface helped users manage the demands of concurrent spatial tasks in a virtual environment. However, participants experienced some unexpected difficulties when faced with a concurrent verbal task.

This paper presents a novel speak-to-VR virtual-reality peripheral network (VRPN) server based on speech processing. The server uses a microphone array as a speech source and streams the results of the process through a Wi-Fi network. The proposed VRPN server provides a handy, portable and wireless human machine interface that can facilitate interaction in a variety interfaces and application domains including HMD- and CAVE-based virtual reality systems, flight and driving simulators and many others. The VRPN server is based on a speech processing software development kits and VRPN library in C++. Speak-to-VR VRPN works well even in the presence of background noise or the voices of other users in the vicinity. The speech processing algorithm is not sensitive to the user's accent because it is trained while it is operating. Speech recognition parameters are trained by hidden Markov model in real time. The advantages and disadvantages of the speak-to-VR server are studied under different configurations. Then, the efficiency and the precision of the speak-to-VR server for a real application are validated via a formal user study with ten participants. Two experimental test setups are implemented on a CAVE system by using either Kinect Xbox or array microphone as input device. Each participant is asked to navigate in a virtual environment and manipulate an object. The experimental data analysis shows promising results and motivates additional research opportunities.

A novel method is presented for enhancing the natural visual perception afforded by augmented reality (AR) workstations. The approach incorporates a method for simulating perspective viewing using a monitor-based AR workstation that acts as a window to the physical workspace in front of it. Although similar AR workstations are often used in industry, they do not provide natural visual perception. By incorporating user head tracking and a spherical mirror, the method proposed enhances visual perception by simulating the depth cue of perspective viewing. The method interactively adjusts the viewing parameters to provide accurate perspective viewing of both the video stream (representing the physical environment) as well as the virtual objects superimposed within it. Hence, the user gains the impression of 3D viewing of the entire AR scene when moving ones head in front of the monitor. This paper describes the hardware setup and the method for perspective simulation within an AR software application. Finally, an experimental evaluation of the accuracy of the system is described to demonstrate the feasibility of the approach.

There is currently no fully natural, general-purpose locomotion interface. Instead, interfaces such as gamepads or treadmills are required to explore large virtual environments (VEs). Furthermore, sensory feedback that would normally be used in real-world movement is often restricted in VR due to constraints such as reduced field of view (FOV). Accommodating these limitations with locomotion interfaces afforded by most virtual reality (VR) systems may induce cognitive demands on the user that are unrelated to the primary task to be performed in the VE. Users of VR systems often have many competing task demands, and additional cognitive demands during locomotion must compete for finite resources. Two studies were previously reported investigating the working memory demands imposed by semi-natural locomotion interfaces (Study 1) and reduced sensory feedback (Study 2). This paper expands on the previously reported results and adds discussion linking the two studies. The results indicated that locomotion with a less natural interface increases spatial working memory demands, and that locomotion with a lower FOV increases general attentional demands. These findings are discussed in terms of their practical implications for selection of locomotion interfaces when designing VEs.

The rare ospC allele L was detected in 30% of Borrelia burgdorferi sensu stricto strains cultured from a tick species, Ixodes affinis , and two rodent host species, Peromyscus gossypinus and Sigmodon hispidus , collected in a coastal plain area of Georgia and South Carolina, in the southeastern United States.