Chemical shielding of H2O and HF encapsulated inside a C60 cage.

Molecular surgery provides the opportunity to study relatively large molecules encapsulated within a fullerene cage. Here we determine the location of an H2O molecule isolated within an adsorbed buckminsterfullerene cage, and compare this to the intrafullerene position of HF. Using normal incidence X-ray standing wave (NIXSW) analysis, coupled with density functional theory and molecular dynamics simulations, we show that both H2O and HF are located at an off-centre position within the fullerene cage, caused by substantial intra-cage electrostatic fields generated by surface adsorption of the fullerene. The atomistic and electronic structure simulations also reveal significant internal rotational motion consistent with the NIXSW data. Despite this substantial intra-cage interaction, we find that neither HF or H2O contribute to the endofullerene frontier orbitals, confirming the chemical isolation of the encapsulated molecules. We also show that our experimental NIXSW measurements and theoretical data are best described by a mixed adsorption site model.

An Evaluation of a Behaviorally Based Social Skills Group for Individuals Diagnosed with Autism Spectrum Disorder.

In this study we evaluated a social skills group which employed a progressive applied behavior analysis model for individuals diagnosed with autism spectrum disorder. A randomized control trial was utilized; eight participants were randomly assigned to a treatment group and seven participants were randomly assigned to a waitlist control group. The social skills group consisted of 32, 2 h sessions. Teachers implemented a variety of behaviorally based procedures. A blind evaluator measured participants' behavior immediately prior to intervention, immediately following intervention, and during 16 and 32-week maintenance probes. Results of the study demonstrated that participants made significant improvements with their social behavior (p < .001) following intervention, and the results were maintained up to 32 weeks after intervention had concluded.

The Effects of the Cool Versus Not Cool Procedure to Teach Social Game Play to Individuals Diagnosed with Autism Spectrum Disorder.

This study evaluated the utility of the cool versus not cool procedure for teaching three structured indoor games to eight children diagnosed with autism spectrum disorder (ASD). The study took place as part of a social skills group for individuals diagnosed with ASD, and this study was one component of that group. The cool versus not cool procedure consisted of the teacher demonstrating each game the cool (i.e., appropriate) and not cool (i.e., inappropriate) way and having the participants provide a rationale as to why the demonstration was either cool or not cool. This was followed by giving the participants the opportunity to role-play the game in front of the group. The teachers utilized unprompted performance probes with no programmed reinforcement to create opportunities for the participants to display the targeted behavior (s). A multiple baseline design across behaviors and replicated across participants was utilized. The results indicated that seven of the eight participants mastered each of the games taught.

Evaluation of multiple-alternative prompts during tact training.

This study compared 2 methods of fading prompts while teaching tacts to 3 individuals who had been diagnosed with autism spectrum disorder (ASD). The 1st method involved use of an echoic prompt and prompt fading. The 2nd method involved providing multiple-alternative answers and fading by increasing the difficulty of the discrimination. An adapted alternating-treatments design showed that both procedures were more effective than a no-intervention control condition. Providing multiple alternatives did not increase error rates or teaching time, and better maintenance was shown for tacts taught with the multiple-alternative prompt.

Changing preference from tangible to social activities through an observation procedure.

Individuals with autism spectrum disorder (ASD) have qualitative impairments in social interaction and often prefer food or tangible reinforcement to social reinforcement. Thus, therapists who work with children with ASD often use food or tangible items as reinforcers to increase appropriate behaviors or decrease problem behaviors. The goal of the present study was to shift children's preferences from a highly preferred tangible item to an initially nonpreferred social reinforcer using an observational conditioning procedure. Participants observed a known peer engage in a simple task and select the social reinforcer that was not preferred by the participant. This procedure resulted in a shift of preference toward the social reinforcer by all participants. Maintenance data showed that although the preference change did not maintain for 1 of the participants, it was quickly reestablished with additional observational trials. Results provide further support for the use of observational procedures to alter preferences.

Comparing the teaching interaction procedure to social stories: a replication study.

This study compared the teaching interaction procedure to social stories implemented in a group setting to teach social skills to three children diagnosed with autism spectrum disorder. The researchers taught each participant one social skill with the teaching interaction procedure, one social skill with the social story procedure, and one social skill was assigned to a no intervention condition. The teaching interaction procedure consisted of didactic questions, teacher demonstration, and role-play; the social story procedure consisted of reading a book and answering comprehension questions. The researchers measured participants' performances during probes, responses to comprehension questions, and responding during role-plays. The results indicated that the teaching interaction procedure was more efficacious than the social story procedure across all three participants.

Growth factor directed chondrogenic differentiation of porcine bone marrow-derived progenitor cells.

BACKGROUND: Despite advances in surgical technique, reconstruction of a mandibular condyle still causes significant donor-site morbidity. The purpose of this study was to compare the effect of 3 different growth factors and define optimal cell culture conditions for bone marrow-derived progenitor cells to differentiate into chondrocytes for mandibular condyle reconstruction. METHODS: Porcine bone marrow-derived progenitor cells (pBMPCs) were cultured as a pellet for 2, 3, and 4 weeks under the following conditions: group 1, TGF-ß3 + standard medium; group 2, TGF-ß3 + BMP-2 + standard medium; group 3, TGF-ß3 + IGF-1 + standard medium; and group 4, TGF-ß3 + BMP-2 + IGF-1 + standard medium. Chondrogenic differentiation was evaluated using 3 lineage differentiation markers. RESULTS: The mean type II collagen positive area increased over weeks 2, 3, and 4 in group 4 compared to all the other groups (ANOVA; P = 0.005). At week 4, there was significantly greater type II collagen production in group 4 compared to all the other groups (ANOVA; P = 0.003). The medium in group 4 produces the greatest amount of cartilage when compared to groups 1, 2, and 3, and that 4 weeks produces the greatest amount of type II collagen. CONCLUSIONS: The results of this study indicate that the most efficacious medium for chondrogenic differentiation of pBMPCs was group 4 medium and the most type II collagen was produced at 4 weeks.

The engineering of craniofacial tissues in the laboratory: a review of biomaterials for scaffolds and implant coatings.

Tissue engineering is a rapidly growing interdisciplinary field that focuses on the interactions between cells, growth factors, and scaffolds to produce replacement tissue and organs. Recent developments in tissue engineering technology include refinements in isolation and differentiation of progenitor cells, 3-D printing technology to produce scaffolds, new biomaterials for scaffolds, and growth factor delivery systems. The purpose of this article is to review advances in biomaterials, scaffolds, and implant coatings for craniomaxillofacial (bone) tissue engineering.