Virtual reality versus conventional clinical role-play for radiographic positioning training: A students' perception study.

INTRODUCTION: Simulated learning environments (SLEs) are commonly utilised by educational institutions. The aim of this study was to assess if students perceptions varied relating to the effectiveness of either a virtual reality (VR) simulation or traditional clinical role-play scenario in developing radiographic hand positioning skills. METHODS: A split-cohort study was performed with Year 1 Undergraduate Radiography students (n = 76). Students were randomly assigned to undertake training for radiographic hand positioning tasks using either the CETSOL VR Clinic software (Group 1) or traditional clinical role-play (Group 2). Following completion of their positioning training, students' perceived impact of the SLE on developing practical and technical skills were assessed using a 5-point Likert scale questionnaire and free text option. RESULTS: Quantitative student perception scores indicated no significant difference between the two simulation modalities, the mean agreement scores (combined strongly agree + agree) for Groups 1 and 2 were 74.8% and 83.8%, respectively, where χ2 (4, n = 66) = 9.5, p-value = 0.394. Key themes expressed by students following a thematic analysis were "engagement with the learning environment, positioning practice and comparability to clinical practice. CONCLUSION: The perceptions of novice students in training for radiographic hand positioning tasks, using either a VR SLE or clinical role-play scenario, did not differ. There was a strong similarity in common themes, however, a key point of difference identified was the benefit of repetition afforded by the VR simulation, in contrast to the need for more time using traditional role-play in a constrained laboratory setting. IMPLICATIONS FOR PRACTICE: The lack of difference in student perceptions between VR and clinical role-play training, could offer a different approach to clinical training which is easily accessible and allows users to correct mistakes at their own pace.

Hydrogen on Cobalt Phosphide.

Cobalt phosphide (CoP) is one of the most promising earth-abundant replacements for noble metal catalysts for the hydrogen evolution reaction (HER). Critical to HER is the binding of H atoms. While theoretical studies have computed preferred sites and energetics of hydrogen bound to transition metal phosphide surfaces, direct experimental studies are scarce. Herein, we describe measurements of stoichiometry and thermochemistry for hydrogen bound to CoP. We studied both mesoscale CoP particles, exhibiting phosphide surfaces after an acidic pretreatment, and colloidal CoP nanoparticles. Treatment with H2 introduced large amounts of reactive hydrogen to CoP, ca. 0.2 H per CoP unit, and on the order of one H per Co or P surface atom. This was quantified using alkyne hydrogenation and H-atom transfer reactions with phenoxy radicals. Reactive H atoms were even present on the as-prepared materials. On the basis of the reactivity of CoP with various molecular hydrogen donating and accepting reagents, the distribution of binding free energies for H atoms on CoP was estimated to be roughly 51-66 kcal mol-1 (ΔG°H ≅ 0 to -0.7 eV vs H2). Operando X-ray absorption spectroscopy gave preliminary indications about the structure of hydrogenated CoP, showing a slight lattice expansion and no significant change of the effective nuclear charge of Co under H2-flow. These results provide a new picture of catalytically active CoP, with a substantial amount of reactive H atoms. This is likely of fundamental relevance for its catalytic and electrocatalytic properties. Additionally, the approach developed here provides a roadmap to examine hydrogen on other materials.

Abnormalities in the Visual Processing of Viewing Complex Visual Stimuli Amongst Individuals With Body Image Concern.

Individuals with body dysmorphic disorder (BDD) and clinically concerning body-image concern (BIC) appear to possess abnormalities in the way they perceive visual information in the form of a bias towards local visual processing. As inversion interrupts normal global processing, forcing individuals to process locally, an upright-inverted stimulus discrimination task was used to investigate this phenomenon. We examined whether individuals with nonclinical, yet high levels of BIC would show signs of this bias, in the form of reduced inversion effects (i.e., increased local processing). Furthermore, we assessed whether this bias appeared for general visual stimuli or specifically for appearance-related stimuli, such as faces and bodies. Participants with high-BIC (n = 25) and low-BIC (n = 30) performed a stimulus discrimination task with upright and inverted faces, scenes, objects, and bodies. Unexpectedly, the high-BIC group showed an increased inversion effect compared to the low-BIC group, indicating perceptual abnormalities may not be present as local processing biases, as originally thought. There was no significant difference in performance across stimulus types, signifying that any visual processing abnormalities may be general rather than appearance-based. This has important implications for whether visual processing abnormalities are predisposing factors for BDD or develop throughout the disorder.

Imaging early consolidation of perceptual learning with face stimuli during rest.

Studies investigating visual perceptual learning (VPL) have traditionally used simple visual tasks and focused on assessing the active (online) processes of learning and memory: encoding and retrieval. The assessment of complex stimuli and the passive (offline) process of consolidation is, however, necessary for a full understanding of the development of VPL and has received little direct analysis. In the current study, 30 young adults completed a VPL task with face stimuli while undergoing an fMRI scan. Activity was assessed within offline rest breaks both during and after the learning task. Changes in baseline activity within functionally-relevant regions were identified during these rest periods. Furthermore, differences in consolidation-related resting activity were evident between individuals who performed well on the active task, and those who performed less well. These findings provide preliminary evidence that activity during offline rest breaks, which immediately follow the active task, is associated with consolidation and learning, in VPL.

Extrastriate cortex and medial temporal lobe regions respond differentially to visual feature overlap within preferred stimulus category.

It has been proposed that domain-specific regions in extrastriate cortex, parahippocampal cortex and the medial temporal lobe (MTL, particularly the hippocampus, HC, and perirhinal cortex, PrC) may respond differently to the degree of feature complexity present in sets of visual stimuli, with the latter two regions tuned to represent the differences among stimuli with a high degree of visual overlap or featural ambiguity (Graham, Barense, & Lee, 2010; Cowell, Bussey, & Saksida, 2010a). To test this prediction, healthy participants viewed blocks containing visually similar or visually different exemplars from four stimulus categories (scenes, faces, inanimate objects and animate objects). Independent functional regions of interest were identified in extrastriate and MTL regions that were preferentially responsive to one or more of these visual categories, and the main experimental data interrogated for any evidence of an interaction between visual category and degree of feature overlap. In PrC and posterior HC (PostHC) viewing sets of stimuli with a large number of overlapping features resulted in greater activity than blocks containing items that were more visually distinct. The opposite pattern was found in fusiform face area (FFA), parahippocampal place area (PPA) and lateral occipital complex (LOC). The increased response in the HC and PrC to high visual similarity was seen only for visual categories that effectively activate these regions (PrC-faces and objects; PostHC-scenes). This study confirms that regions throughout the visual ventral stream, parahippocampal cortex and MTL are engaged differentially by visual complexity, consistent with recent lesion experiments in which MTL damage affects discrimination and learning of, as well as recognition memory for, exemplars with a high degree of visual feature overlap.

Simultaneous presentation of similar stimuli produces perceptual learning in human picture processing.

Human participants received unsupervised exposure to difficult-to-discriminate stimuli (e.g., A and A'), created with a morphing procedure from photographs of faces, before learning a discrimination between them. Experiments 1 and 2 demonstrated that prior exposure enhanced later discrimination and that intermixed exposure (A, A', A, A'...) resulted in better subsequent discrimination than blocked exposure (B, B, ...B', B'...). Experiments 3 and 4 showed that simultaneous exposure to 2 similar stimuli facilitated the later acquisition of both a simultaneous and a successive discrimination, and this effect was observed even though simultaneous exposure to 2 stimuli fostered the development of an excitatory association between them (Experiment 5). The findings of Experiments 1 and 2 revealed a perceptual learning effect with pictures of faces, and the findings of Experiments 3-5 are difficult to reconcile with associative analyses of perceptual learning.

Inhibitory associations contribute to perceptual learning in humans.

Perceptual learning in humans was examined in 2 experiments. In Experiment 1, participants received intermixed exposure to 2 similar compounds (AX, BX, AX, BX, . . .) and blocked exposure to a 2nd pair of similar compounds (CY, CY, . . . , DY, DY, . . .). Aversions established to AX and CY generalized less to BX than to DY. In Experiment 2, 1 pair of compounds was presented in a forward order (i.e., AX3BX), whereas the 2nd pair of compounds was presented in a backward order (i.e., DY-->CY). Aversions established to AX and CY generalized less to BX than to DY. These results indicate that inhibitory associations contribute to perceptual learning in humans and thereby establish a fundamental similarity between the mechanisms that underlie perceptual learning in humans and rats.

Otitis media in childhood in relation to preschool language and school readiness skills among black children.

OBJECTIVE: To examine whether otitis media with effusion (OME) and associated hearing loss (HL) during the first 5 years of life were related to children's language skills during the preschool years and to school readiness skills at entry to kindergarten. METHODS: In a prospective study, the ears of 85 black children primarily from low-income families and recruited from community-based childcare programs were repeatedly examined from 6 months to 5 years of age for the presence of OME and from 6 months to 4 years of age for HL when well and ill with OME. Assessments were made annually of the children's child-rearing environments at home and in childcare, and children's language skills between 3 and 5 years of age and readiness skills in literacy and math were evaluated at entry into kindergarten. RESULTS: Children had either bilateral or unilateral OME approximately 30.4% and HL 19.6% of the observation time. OME and associated HL were significantly positively correlated with some measures of expressive language at 3 and 4 years of age; however, these direct relationships were no longer significant when the child's gender, socioeconomic status, maternal educational level, and the responsiveness and support of the home and childcare environments were also considered. Further, both OME and HL were moderately correlated with school readiness skills at entry to school, with children having more OME scoring lower in verbal math problems and with children with more HL scoring lower in math and recognizing incomplete words. These associations continued to remain significant even after partialing out the child and family background factors. CONCLUSIONS: There was not a significant relationship between children's early OME history or HL and language skills during the preschool years. However, children with more frequent OME had lower scores on school readiness measures. These associations were moderate in degree, however, and the home environment was more strongly related to academic outcomes than was OME or HL. These results should be interpreted cautiously when generalizing to other populations.

The dynamics of trust: comparing humans to automation.

Complex industrial environments involve cooperation between operators and automation. The strategies used to allocate tasks to automation are a crucial component of that cooperation and are known to be affected by the operators' trust in the automation. In 2 simulated process control experiments, the authors compared trust in automation with trust in human partners in equivalent situations. Experiment 1 found the relationship between trust and task allocation to be qualitatively identical, but quantitatively attenuated, for human partners as compared with automation. Experiment 2 additionally identified the operators' trustworthiness, as they thought it would be perceived by a human partner, as crucial to task allocation under human collaboration but not under automation. The results imply that human collaboration benefits from calibration of people's assessment of how others perceive them.

A comparison of nebulized budesonide, intramuscular dexamethasone, and placebo for moderately severe croup.

BACKGROUND: In children with croup, treatment with nebulized budesonide decreases symptoms, but it is uncertain how budesonide compares with dexamethasone, the conventional therapy for croup, and whether either reduces the rate of hospitalization. METHODS: We performed a double-blind, randomized trial involving 144 children with moderately severe croup. The children were treated with racepinephrine and a single dose of 4 mg of nebulized budesonide (48 children), 0.6 mg of intramuscular dexamethasone per kilogram of body weight (47 children), or placebo (49 children). The children were assessed before treatment and then hourly for five hours after treatment. Physicians who were unaware of the treatment assignments determined the children's need for further treatment and hospitalization. RESULTS: The characteristics of the groups were similar at base line, including the types of viruses identified, the types of croup, and the clinical severity of the illness. The overall rates of hospitalization were 71 percent in the placebo group (35 of 49 children), 38 percent in the budesonide group (18 of 48 children), and 23 percent in the dexamethasone group (11 of 47 children) (unadjusted P=0.001 for the comparison of budesonide with placebo, P<0.001 for the comparison of dexamethasone with placebo, and P=0.18 for the comparison of budesonide with dexamethasone). Children treated with budesonide or dexamethasone had a greater improvement in croup scores than those given placebo (P=0.03 and P<0.001, respectively), and those treated with dexamethasone had a greater improvement than those treated with budesonide (P=0.003). CONCLUSIONS: In children with moderately severe croup, treatment with intramuscular dexamethasone or nebulized budesonide resulted in more rapid clinical improvement than did the administration of placebo, with dexamethasone offering the greatest improvement. Treatment with either glucocorticoid resulted in fewer hospitalizations.

Otitis media, the caregiving environment, and language and cognitive outcomes at 2 years.

OBJECTIVE: To examine the relationship between otitis media with effusion (OME) and associated hearing loss between 6 and 24 months of age and children's language and cognitive development at 2 years of age. STUDY DESIGN: A prospective cohort design in which 86 African-American infants who attended group child-care centers were recruited between 6 and 12 months of age. Between 6 and 24 months, assessments included serial ear examinations using otoscopy and tympanometry, serial hearing tests, two ratings of the childrearing environment at home and in child care, and language and cognitive outcomes at 2 years. RESULTS: Children experienced either unilateral or bilateral OME an average of 63% and reduced hearing sensitivity an average of 44% of the time between 6 and 24 months of age. Although proportion of time with OME or with hearing loss was modestly correlated with measures of language and cognitive skills, these relationships were no longer significant when the ratings of the home and child-care environments were also considered. Children with more OME or hearing loss tended to live in less responsive caregiving environments, and these environments were linked to lower performance in expressive language and vocabulary acquisition at 2 years. CONCLUSIONS: Both OME and hearing loss were more strongly related to the quality of home and child-care environments than to children's language and cognitive development. Study results might be explained either by suggesting that children in less responsive caregiving environments experience conditions that make them more likely to experience OME and/or by suggesting that it may be more difficult for caregivers to be responsive and stimulating with children with more OME.

A comparison of Culture-Free Self-Esteem Scale means from different child and adolescent groups.

The Culture-Free Self-Esteem Inventory (CFSEI-2) was administered to 7 groups of children: 84 White Catholic school students from a New Orleans suburb, 78 White rural public school students from Virginia, 62 Hispanic Migrant student from Florida, 90 Aboriginal and White students from an isolated Canadian community, 199 African American students attending an inner city school, 60 Hispanic and White international students from Venezuela, and 61 Innuit students from isolated community in Labrador. The four elder groups also wrote three words to describe themselves (the Adjective Generation Technique [AGT]). Significant differences in responding between groups were found on all CFSEI-2 scales and for AGT favorability means. Although several possible reasons for these results are discussed, we conclude that the CFSEI-2 is not culture-free. Recommendations are: change the title of the test to avoid misrepresentation, limit test usage to elementary school children, develop an adolescent version with age appropriate language, and construct local norms before using the CFSEI-2 to make decisions about a child's self-esteem. To determine relevance of scores, a team of professionals and lay persons should review items from this or any test given to children who may be different from the normative or standardization group.

Developmental changes in static admittance and tympanometric width in infants and toddlers.

Longitudinal measures of peak-compensated static acoustic admittance and tympanometric width are reported for infants and toddlers from 6 months to 30 months of age, based on over 1600 assessments of 88 children during a 24-month period. The subjects were all African-American children in full-time day care. Significant age effects were observed, with younger children displaying lower static admittance values and wider tympanograms. The results of this investigation underscore the importance of age- and population-specific norms when using acoustic admittance measures to evaluate middle ear status in children.

Otitis media, hearing sensitivity, and maternal responsiveness in relation to language during infancy.

The relation of otitis media with effusion (OME) and associated hearing loss to language and cognitive skills at 1 year of age was studied to determine whether OME-related hearing loss had a direct association with language and cognitive outcomes at 1 year of age or an indirect association with these outcomes, as mediated by the child-rearing environment. Subjects were 61 black infants attending community-based child care programs. The presence of OME was assessed biweekly from 6 to 12 months of age by otoscopy and tympanometry. Hearing was assessed with visual reinforcement audiometry when children were well and when ill with OME. Language and cognitive skills and the child-rearing environment at home and in child care were examined. The results indicated a modest correlation between hearing loss associated with OME and receptive language. However, the direct association between OME-related hearing loss and all the language and cognitive measures was negligible. Hearing loss had an indirect association with receptive and expressive language, cognitive development, and overall communication as mediated by child-rearing factors. That is, children with more frequent hearing loss tended to have less responsive mothers and home environments, and this association was linked to lower performance on the infant assessments.

The effect of eating on transit through the small intestine.

The effect of eating on the transit of radiolabelled particles through the small intestine has been monitored in eight healthy subjects dosed after an overnight fast. Each subject participated on three occasions and either remained fasting for 9 h after dosing or consumed a meal at 1.5 h or 4 h. The mean +/- 1 S.D. small intestinal transit time during the fasting study was 5.5 +/- 2.1 h and during the 1.5h and 4 h fed studies 4.8 +/- 2.9 h and 4.7 +/- 2.2 h, respectively. These times were not significantly different, nor were the rates of entry of the particles into the colon. These findings indicate that once in the small intestine the efficacy of orally administered pharmaceutical preparations is unlikely to be affected by eating.

Sensorineural hearing loss: infectious agents.

Twenty-eight children with sensorineural hearing loss resulting from viral (17) or infectious (11) agents were analyzed according to the degree and stability of the loss and the age at identification. Early identification and determination of etiology is enhanced when a viral screen is performed in the nursery, and of questionable value when viral studies are done later. Eighty percent of the the children who sustained a permanent loss as a result of meningitis had severe-profound losses. Serial hearing testing should be done every 6 months for these children who are at risk for progression or fluctuations in their hearing loss.