A pilot study characterizing gravesoil bacterial communities a decade after swine decomposition.

Vertebrate decomposition leads to an efflux of fluids rich with biochemicals and microbes from the carcass into the surrounding soil affecting the endogenous soil bacterial community. These perturbations are detectable in soils associated with carcasses (gravesoil) and influence soil bacterial ecology for years after the decomposition event, but it is unknown for how long. Measuring these impacts over extended timescales is critical to expanding vertebrate decomposition's role in the ecosystem and may provide useful information to forensic science. Using 16S rRNA gene amplicon data, this study surveyed bacterial composition in terrestrial soils associated with surface-exposed swine decomposition for 10 years after carcass placement. This pilot study utilizes the increased statistical power associated with repeated measure/within-subjects sampling to analyze bacterial diversity trends over time. Our results demonstrate that the soil bacterial diversity was significantly impacted by decomposition, with this impact being localized to the area underneath the carcass. Bacterial community dissimilarity was greatest 12 months postmortem before beginning recovery. Additionally, random forest regressions were utilized to determine 10 important genera for distinguishing decomposition timepoints, an important component of forensic investigations. Of these 10 genera, four were further analyzed for their significant relative abundance shifts underneath the carcass. This pilot study helps expand the current knowledge of long-term effects of carcass decomposition on soil bacterial communities, and is the first to our knowledge to characterize these communities temporally from placement through a decade of decomposition.

Evaluation of the cognitive effects of travel technique in complex real and virtual environments.

We report a series of experiments conducted to investigate the effects of travel technique on information gathering and cognition in complex virtual environments. In the first experiment, participants completed a non-branching multilevel 3D maze at their own pace using either real walking or one of two virtual travel techniques. In the second experiment, we constructed a real-world maze with branching pathways and modeled an identical virtual environment. Participants explored either the real or virtual maze for a predetermined amount of time using real walking or a virtual travel technique. Our results across experiments suggest that for complex environments requiring a large number of turns, virtual travel is an acceptable substitute for real walking if the goal of the application involves learning or reasoning based on information presented in the virtual world. However, for applications that require fast, efficient navigation or travel that closely resembles real-world behavior, real walking has advantages over common joystick-based virtual travel techniques.

The Agrobacterium rhizogenes GALLS gene encodes two secreted proteins required for genetic transformation of plants.

Agrobacterium tumefaciens and Agrobacterium rhizogenes are related pathogens that cause crown gall and hairy root diseases, which result from integration and expression of bacterial genes in the plant genome. Single-stranded DNA (T strands) and virulence proteins are translocated into plant cells by a type IV secretion system. VirD2 nicks a specific DNA sequence, attaches to the 5' end, and pilots the DNA into plant cells. A. tumefaciens translocates single-stranded DNA-binding protein VirE2 into plant cells where it likely binds T strands and may aid in targeting them into the nucleus. Although some A. rhizogenes strains lack VirE2, they transfer T strands efficiently due to the GALLS gene, which complements an A. tumefaciens virE2 mutant for tumor formation. Unlike VirE2, full-length GALLS (GALLS-FL) contains ATP-binding and helicase motifs similar to those in TraA, a strand transferase involved in conjugation. GALLS-FL and VirE2 contain nuclear localization signals (NLS) and secretion signals. Mutations in any of these domains abolish the ability of the GALLS gene to substitute for virE2. Here, we show that the GALLS gene encodes two proteins from one open reading frame: GALLS-FL and a protein comprised of the C-terminal domain, which initiates at an internal in-frame start codon. On some hosts, both GALLS proteins were required to substitute for VirE2. GALLS-FL tagged with yellow fluorescent protein localized to the nucleus of tobacco cells in an NLS-dependent manner. In plant cells, the GALLS proteins interacted with themselves, VirD2, and each other. VirD2 interacted with GALLS-FL and localized inside the nucleus, where its predicted helicase activity may pull T strands into the nucleus.

Virtual reality exposure therapy and standard (in vivo) exposure therapy in the treatment of fear of flying.

This controlled clinical trial tested virtual reality exposure (VRE) therapy for the fear of flying (FOF), a relatively new and innovative way to do exposure therapy, and compared it to standard (in vivo) exposure therapy (SE) and a wait list (WL) control with a 6- and 12-month follow-up. Eighty-three participants with FOF were randomly assigned to VRE, SE, or WL. Seventy-five participants, 25 per group, completed the study. Twenty-three WL participants completed randomly assigned treatment following the waiting period. Treatment consisted of 4 sessions of anxiety management training followed either by exposure to a virtual airplane (VRE) or an actual airplane at the airport (SE) conducted over 6 weeks. Results indicate that VRE was superior to WL on all measures, including willingness to fly on the posttreatment flight (76% for VRE and SE; 20% for WL). VRE and SE were essentially equivalent on standardized questionnaires, willingness to fly, anxiety ratings during the flight, self-ratings of improvement, and patient satisfaction with treatment. Follow-up assessments at 6 and 12 months indicated that treatment gains were maintained, with more than 70% of respondents from both groups reporting continued flying at follow-up. Based on these findings, the use of VRE in the treatment of FOF was supported in this controlled study, suggesting that experiences in the virtual world can change experiences in the real world.

Cognitive behavior therapy for fear of flying: sustainability of treatment gains after September 11.

This study examines the long-term efficacy of cognitive-behavioral therapy (CBT) for fear of flying (FOF) after a catastrophic fear-relevant event, the September 11, 2001, terrorist attacks. Participants (N = 115) were randomly assigned to and completed treatment for FOF using 8 sessions of either virtual reality exposure therapy (VRE) or standard exposure therapy (SE) prior to September 11, 2001. Individuals were reassessed in June, 2002, an average of 2.3 years after treatment, with a response rate of 48% (n = 55). Analyses were run on the original data and, using multiple imputation procedures, on imputed data for the full sample. Individuals maintained or improved upon gains made in treatment as measured by standardized FOF questionnaires and by number of flights taken. There were no differences between VRE and SE. Thus, results suggest that individuals previously treated for FOF with cognitive-behavioral therapy can maintain treatment gains in the face of a catastrophic fear-relevant event, even years after treatment is completed.

Responses to a virtual reality grocery store in persons with and without vestibular dysfunction.

People with vestibular dysfunction often complain of having difficulty walking in visually complex environments. Virtual reality (VR) may serve as a useful therapeutic tool for providing physical therapy to these people. The purpose of this pilot project was to explore the ability of people with and without vestibular dysfunction to use and tolerate virtual environments that can be used in physical therapy. We have chosen grocery store environments, which often elicit complaints from patients. Two patients and three control subjects were asked to stand and navigate in VR grocery stores while finding products. Perceived discomfort, simulator sickness symptoms, distance traveled, and speed of head movement were recorded. Symptoms and discomfort increased in one subject with vestibular dysfunction. The older subjects traveled a shorter distance and had greater speed of head movements compared with young subjects. Environments with a greater number of products resulted in more head movements and a shorter distance traveled.

Cognitive enhancers as adjuncts to psychotherapy: use of D-cycloserine in phobic individuals to facilitate extinction of fear.

BACKGROUND: Traditional pharmacological approaches to treating psychiatric disorders focus on correcting presumed biochemical abnormalities. However, some disorders, particularly the anxiety-related disorders exemplified by specific phobia, have an emotional learning component to them that can be facilitated with psychotherapy. OBJECTIVE: To determine whether D-cycloserine (DCS), a partial agonist at the N-methyl-d-aspartate receptor that has previously been shown to improve extinction of fear in rodents, will also improve extinction of fear in human phobic patients undergoing behavioral exposure therapy. DESIGN: Randomized, double-blind, placebo-controlled trial examining DCS vs placebo treatment in combination with a precisely controlled exposure paradigm. SETTING: Participants were recruited from the general community to a research clinic. PARTICIPANTS: Twenty-eight subjects with acrophobia diagnosed by the Structured Clinical Interview for DSM-IV were enrolled. INTERVENTIONS: After we obtained pretreatment measures of fear, subjects were treated with 2 sessions of behavioral exposure therapy using virtual reality exposure to heights within a virtual glass elevator. Single doses of placebo or DCS were taken prior to each of the 2 sessions of virtual reality exposure therapy. Subjects, therapists, and assessors were blind to the treatment condition. Subjects returned at 1 week and 3 months posttreatment for measures to determine the presence and severity of acrophobia symptoms. MAIN OUTCOME MEASURES: Included were measures of acrophobia within the virtual environment, measures of acrophobia in the real world, and general measures of overall improvement. An objective measure of fear, electrodermal skin fluctuation, was also included during the virtual exposure to heights. Symptoms were assessed by self-report and by independent assessors at approximately 1 week and 3 months posttreatment. RESULTS: Exposure therapy combined with DCS resulted in significantly larger reductions of acrophobia symptoms on all main outcome measures. Subjects receiving DCS had significantly more improvement compared with subjects receiving placebo within the virtual environment (1 week after treatment, P

Comparison of path visualizations and cognitive measures relative to travel technique in a virtual environment.

We describe a between-subjects experiment that compared four different methods of travel and their effect on cognition and paths taken in an immersive virtual environment (IVE). Participants answered a set of questions based on Crook's condensation of Bloom's taxonomy that assessed their cognition of the IVE with respect to knowledge, understanding and application, and higher mental processes. Participants also drew a sketch map of the IVE and the objects within it. The users' sense of presence was measured using the Steed-Usoh-Slater Presence Questionnaire. The participants' position and head orientation were automatically logged during their exposure to the virtual environment. These logs were later used to create visualizations of the paths taken. Path analysis, such as exploring the overlaid path visualizations and dwell data information, revealed further differences among the travel techniques. Our results suggest that, for applications where problem solving and evaluation of information is important or where opportunity to train is minimal, then having a large tracked space so that the participant can walk around the virtual environment provides benefits over common virtual travel techniques.

A pilot and feasibility study of virtual reality as a distraction for children with cancer.

OBJECTIVE: To pilot and test the feasibility of a novel technology to reduce anxiety and pain associated with an invasive medical procedure in children with cancer. METHOD: Children with cancer (ages 7-19) whose treatment protocols required access of their subcutaneous venous port device (port access) were randomly assigned to a virtual reality distraction intervention, a non-virtual reality distraction, or treatment as usual without a distraction. The researchers obtained assessments of the child's pain and anxiety from the parent, child, and unblinded nurses. Pulse rate was monitored throughout the procedure, and behavioral indices of distress were recorded, as observed by the researchers. RESULTS: Reductions in pain and anxiety were found for children who used the virtual reality distraction in comparison with the no distraction condition as evidenced by lower pulse rate and reports of pain by nurses. No significant differences were found for the non-virtual reality condition versus the no distraction condition on pulse rate. CONCLUSIONS: These findings suggest that virtual reality may be a useful tool for distraction during painful medical procedures, but further studies are needed to test potential efficacy and feasibility during other, more distressing medical procedures with larger sample sizes.

Twelve-month follow-up of virtual reality and standard exposure therapies for the fear of flying.

This study reports the 12-month follow-up from patients with the fear of flying who were treated in a controlled study and randomly assigned (n = 49) to virtual reality exposure (VRE) therapy, standard exposure (SE) therapy, or to a wait-list control (WL). VRE and SE were equally superior to WL. At 12 months posttreatment, data were gathered on 24 of the 30 (80%) patients who were assigned to VRE or SE. Patients maintained their treatment gains, and 92% of VRE participants and 91% of SE participants had flown on a real airplane since the graduation flight. This is the 1st year-long follow-up of patients having been treated with VRE and indicates that short-term treatment can have lasting effects.

Simulator sickness when performing gaze shifts within a wide field of view optic flow environment: preliminary evidence for using virtual reality in vestibular rehabilitation.

BACKGROUND: Wide field of view virtual environments offer some unique features that may be beneficial for use in vestibular rehabilitation. For one, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. However, wide FOV devices also have been found to result in greater simulator sickness. Before a wide FOV device can be used in a clinical setting, its safety must be demonstrated. METHODS: Symptoms of simulator sickness were recorded by 9 healthy adult subjects after they performed gaze shifting tasks to locate targets superimposed on an optic flow background. Subjects performed 8 trials of gaze shifting on each of the six separate visits. RESULTS: The incidence of symptoms of simulator sickness while subjects performed gaze shifts in an optic flow environment was lower than the average reported incidence for flight simulators. The incidence was greater during the first visit compared with subsequent visits. Furthermore, the incidence showed an increasing trend over the 8 trials. CONCLUSION: The performance of head unrestrained gaze shifts in a wide FOV optic flow environment is tolerated well by healthy subjects. This finding provides rationale for testing these environments in people with vestibular disorders, and supports the concept of using wide FOV virtual reality for vestibular rehabilitation.

Use of virtual reality as a distractor for painful procedures in a patient with pediatric cancer: a case study.

Virtual reality (VR) has been demonstrated as an effective tool to help people overcome a variety of anxiety disorders. In this case study, the use of VR as a distractor to alleviate pain and anxiety associated with an invasive medical procedure for a pediatric cancer patient was explored. An A-B-C-A design during four consecutive medical appointments in an outpatient oncology clinic compared no distraction (A), non-VR distraction on a computer screen (B), and VR distraction with a head set (C). Behavioral observations of distress by the researcher and reports of pain and anxiety by the patient, parent, and nurse were taken before and during the procedure. The child's pulse was monitored throughout the procedure. The findings from this case study suggest benefit from using VR distraction, as indicated by lower pain and anxiety ratings, reduced pulse, and fewer observed behavioral indices of distress. The need for larger scale studies and application of VR with younger children is discussed in the context of confirming effectiveness of this technique and providing more generalizable information about efficacy.

Effects of virtual human animation on emotion contagion in simulated inter-personal experiences.

We empirically examined the impact of virtual human animation on the emotional responses of participants in a medical virtual reality system for education in the signs and symptoms of patient deterioration. Participants were presented with one of two virtual human conditions in a between-subjects experiment, static (non-animated) and dynamic (animated). Our objective measures included the use of psycho-physical Electro Dermal Activity (EDA) sensors, and subjective measures inspired by social psychology research included the Differential Emotions Survey (DES IV) and Positive and Negative Affect Survey (PANAS). We analyzed the quantitative and qualitative measures associated with participants’ emotional state at four distinct time-steps in the simulated interpersonal experience as the virtual patient’s medical condition deteriorated. Results suggest that participants in the dynamic condition with animations exhibited a higher sense of co-presence and greater emotional response as compared to participants in the static condition, corresponding to the deterioration in the medical condition of the virtual patient. Negative affect of participants in the dynamic condition increased at a higher rate than for participants in the static condition. The virtual human animations elicited a stronger response in negative emotions such as anguish, fear, and anger as the virtual patient’s medical condition worsened.

Virtual human versus human administration of photographic lineups.

One solution to mistaken identification by a crime's victims and eyewitnesses is to use a virtual officer to conduct identification procedures. Results from a study comparing a virtual officer with a live human investigator indicate that the virtual officer performs comparably to the human in terms of identification accuracy, emotional affect, and ease of use.

Agrobacterium rhizogenes GALLS protein contains domains for ATP binding, nuclear localization, and type IV secretion.

Agrobacterium tumefaciens and Agrobacterium rhizogenes are closely related plant pathogens that cause different diseases, crown gall and hairy root. Both diseases result from transfer, integration, and expression of plasmid-encoded bacterial genes located on the transferred DNA (T-DNA) in the plant genome. Bacterial virulence (Vir) proteins necessary for infection are also translocated into plant cells. Transfer of single-stranded DNA (ssDNA) and Vir proteins requires a type IV secretion system, a protein complex spanning the bacterial envelope. A. tumefaciens translocates the ssDNA-binding protein VirE2 into plant cells, where it binds single-stranded T-DNA and helps target it to the nucleus. Although some strains of A. rhizogenes lack VirE2, they are pathogenic and transfer T-DNA efficiently. Instead, these bacteria express the GALLS protein, which is essential for their virulence. The GALLS protein can complement an A. tumefaciens virE2 mutant for tumor formation, indicating that GALLS can substitute for VirE2. Unlike VirE2, GALLS contains ATP-binding and helicase motifs similar to those in TraA, a strand transferase involved in conjugation. Both GALLS and VirE2 contain nuclear localization sequences and a C-terminal type IV secretion signal. Here we show that mutations in any of these domains abolished the ability of GALLS to substitute for VirE2.

Cognitive behavioral therapy for public-speaking anxiety using virtual reality for exposure.

This study used an open clinical trial to test a cognitive-behavioral treatment for public-speaking anxiety that utilized virtual reality as a tool for exposure therapy. Treatment was completed by participants (n = 10) meeting the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria for social phobia, or panic disorder with agoraphobia in which public speaking was the predominantly feared stimulus. Treatment was conducted by a licensed psychologist in an outpatient clinic. Treatment consisted of eight individual therapy sessions, including four sessions of anxiety management training and four sessions of exposure therapy using a virtual audience, according to a standardized treatment manual. Participants completed standardized self-report questionnaires assessing public-speaking anxiety at pre-treatment, post-treatment, and 3-month follow-up. Participants were asked to give a speech to an actual audience at pre- and post-treatment. Results showed decreases on all self-report measures of public-speaking anxiety from pre- to post-treatment, which were maintained at follow-up (n = 8; all P = 05). Participants were no more likely to complete a speech post-treatment than at pre-treatment. This study provides preliminary evidence that a cognitive-behavioral treatment using virtual reality for exposure to public speaking may reduce public-speaking anxiety and suggests that further research with a controlled design is needed.

Agrobacterium rhizogenes GALLS protein substitutes for Agrobacterium tumefaciens single-stranded DNA-binding protein VirE2.

Agrobacterium tumefaciens and Agrobacterium rhizogenes transfer plasmid-encoded genes and virulence (Vir) proteins into plant cells. The transferred DNA (T-DNA) is stably inherited and expressed in plant cells, causing crown gall or hairy root disease. DNA transfer from A. tumefaciens into plant cells resembles plasmid conjugation; single-stranded DNA (ssDNA) is exported from the bacteria via a type IV secretion system comprised of VirB1 through VirB11 and VirD4. Bacteria also secrete certain Vir proteins into plant cells via this pore. One of these, VirE2, is an ssDNA-binding protein crucial for efficient T-DNA transfer and integration. VirE2 binds incoming ssT-DNA and helps target it into the nucleus. Some strains of A. rhizogenes lack VirE2, but they still transfer T-DNA efficiently. We isolated a novel gene from A. rhizogenes that restored pathogenicity to virE2 mutant A. tumefaciens. The GALLS gene was essential for pathogenicity of A. rhizogenes. Unlike VirE2, GALLS contains a nucleoside triphosphate binding motif similar to one in TraA, a strand transferase conjugation protein. Despite their lack of similarity, GALLS substituted for VirE2.