Developing and Refining Instruments and Methods for Diagnostic and Language Assessment of Young Children with Autism Spectrum Disorders (ASD).

Earlier provision of services and treatments is associated with better outcomes in Autism Spectrum Disorders (ASD). Researchers and clinicians recognize the increasing need for diagnostic instruments that are appropriate for toddlers and young preschoolers to capture the early signs of autism. However, comprehensive assessment of ASD for toddlers and young preschoolers has been compromised by lower diagnostic validity of preexisting instruments for these children. Therefore, the first two studies in this three-study dissertation focus on improving and expanding the valid use of pre-existing diagnostic measures for toddlers and young preschoolers with ASD from 12 to 47 months of age. The first study achieves this by developing new diagnostic algorithms for a widely used diagnostic instrument. The second study is focused on evaluating different diagnostic methods to use information from the instrument included in the first study and another commonly used diagnostic instrument in a way that maximizes the diagnostic validity of the instruments. Language skills in young children with ASD have been found to be one of the most important variables predicting better outcomes in later childhood and adulthood. However, there have not generally been standardized instruments that measure spontaneous expressive language of children with ASD in a relatively naturalistic setting. Therefore, the third study of this dissertation focuses on developing a new measure for children with ASD and other communication disorders from 2 to 12 years of age for the valid description of spontaneous language use in a standardized, but naturalistic, setting. Overall, this dissertation is focused on developing and refining instruments and methods for the diagnostic and language assessment of young children with ASD. The newly developed and identified diagnostic algorithms and methods for toddlers and preschoolers will enhance the early identification and provision of treatment for these young children. The new language measure will allow clinicians and researchers to describe the current level of language and quantify language impairments in relation to autism symptoms for children with ASD. These newly developed and improved diagnostic and language measures will provide useful information for treatment and education programs promoting more positive outcomes for young children with ASD.Ph.D.PsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/91478/1/sohkim_1.pd

Restricted and repetitive behaviors in toddlers and preschoolers with autism spectrum disorders based on the Autism Diagnostic Observation Schedule (ADOS)

Restricted and repetitive behaviors (RRBs) observed during the Autism Diagnostic Observation Schedule [ADOS: Lord et al., 2000] were examined in a longitudinal data set of 455 toddlers and preschoolers (age 8–56 months) with clinical diagnosis of Autism Spectrum Disorders (ASD; autism, n =121 and pervasive developmental disorders—not otherwise specified (PDD-NOS), n =71), a nonspectrum disorder (NS; n =90), or typical development (TD; n =173). Even in the relatively brief semi-structured observations, GEE analyses of the severity and prevalence of RRBs differentiated children with ASD from those with NS and TD across all ages. RRB total scores on the ADOS were stable over time for children with ASD and NS; however, typically developing preschoolers showed lower RRB scores than typically developing toddlers. Nonverbal IQ (NVIQ) was more strongly related to the prevalence of RRBs in older children with PDD-NOS, NS, and TD than younger children under 2 years and those with autism. Item analyses revealed different relationships between individual items and NVIQ, age, diagnosis, and gender. These findings are discussed in terms of their implications for the etiology and treatment of RRBs as well as for the framework of ASD diagnostic criteria in future diagnostic systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77983/1/142_ftp.pd

Effect of a Er, Cr:YSGG laser and a Er:YAG laser treatment on oral biofilm-contaminated titanium

Implant surface decontamination is a challenging procedure for therapy of peri-implant disease. Objective: This study aimed to compare the effectiveness of decontamination on oral biofilm-contaminated titanium surfaces in Er:YAG laser, Er, Cr:YSGG laser, and plastic curette. Methodology: For oral biofilms formation, six participants wore an acrylic splint with eight titanium discs in the maxillary arch for 72 hours. A total of 48 contaminated discs were distributed among four groups: untreated control; decontamination with plastic curettes; Er, Cr:YSGG laser; and Er:YAG laser irradiation. Complete plaque removal was estimated using naked-eye and the time taken was recorded; the residual plaque area was measured and the morphological alteration of the specimen surface was observed by scanning electron microscopy. The total bacterial load and the viability of adherent bacteria were quantified by live or dead cell labeling with fluorescence microscopy. Results: The mean treatment time significantly decreased based on the treatment used in the following order: Er:YAG, Er, Cr:YSGG laser, and plastic curettes (234.9±25.4 sec, 156.1±12.7 sec, and 126.4±18.6 sec, P=0.000). The mean RPA in the Er, Cr:YSGG laser group (7.0±2.5%) was lower than Er:YAG and plastic curettes groups (10.3±2.4%, 12.3±3.6%, p=0.023). The viable bacteria on the titanium surface after Er, Cr:YSGG laser irradiation was significantly lower compared to the decontamination with plastic curette (P=0.05) but it was not significantly different from the Er:YAG laser irradiation. Conclusion: We found that Er:YAG laser and Er, Cr:YSGG laser irradiation were effective methods for decontaminations without surface alterations

Effects of muscular response for the intensity of vibratory stimulus applied on the ankle tendon

The present study was conducted to measure the individual threshold value for the somatosensory system of the human body, the thresholds value of vibratory stimulus were assessed through the ascent and descent methods. In the interests of the attainment of this study`s goal, comparing the thresholds value measured and change of state of the muscles when applied on the ankle tendon connected to muscles, changes in threshold measurement accuracy due to the differences in measuring methods were discussed. The experiment was conducted by constructing systems to stimulate somethetic sensibility by vibratory stimulus, ultrasound imaging system and EMG system. Five adult males were involved in this experiment. According to the results of experiments, the threshold value of somatosensory stimulation measured by the ascent method was greater than the threshold values measured by the descent method. And the muscular response to the somatosensory stimulation applied to the tibialis anterior tendon showed a larger rate of change with the ascending stimulus than with the descending stimulus. The results of this study could serve as a basis to discuss the reliability of the measurement method of the human body’s individual threshold value for the somatosensory system through the ascent and descent methods and can be used as reference data for the integration and performance threshold measurement methods

A study on the changes in gait characteristics by applying sub-threshold vibration stimulus in the ankle

This study was conducted to suggest the potential use of a mechanical vibration stimulus in the ankle to correct gait abnormalities. As for the mechanical vibration stimulus, different locations and durations are suggested based on the detection results of real-time gait patterns. 5 young males participated in this study. They were asked to perform assigned gait tasks when either a threshold or sub-threshold stimulus was applied in the tibialis anterior and Achilles tendon. The analysis results of gait cycle and muscle activity showed the changes on gait cycle, the activity pattern of used muscle for gait and the movement pattern of the ankle were observed based on the applied locations of vibration stimulus. Also, the result of sub-threshold stimulus showed similar effects as that of threshold stimulus. As such, the mechanical vibration stimulus was considered to affect gait by being adjusted its characteristics and local stimulus also would affect human body systemically. The result of this study can be used as basic data for the correction of individual’s specific gait abnormality and rehabilitation using vibration stimulus

Partial Sum Minimization of Singular Values in Robust PCA: Algorithm and Applications

Robust Principal Component Analysis (RPCA) via rank minimization is a powerful tool for recovering underlying low-rank structure of clean data corrupted with sparse noise/outliers. In many low-level vision problems, not only it is known that the underlying structure of clean data is low-rank, but the exact rank of clean data is also known. Yet, when applying conventional rank minimization for those problems, the objective function is formulated in a way that does not fully utilize a priori target rank information about the problems. This observation motivates us to investigate whether there is a better alternative solution when using rank minimization. In this paper, instead of minimizing the nuclear norm, we propose to minimize the partial sum of singular values, which implicitly encourages the target rank constraint. Our experimental analyses show that, when the number of samples is deficient, our approach leads to a higher success rate than conventional rank minimization, while the solutions obtained by the two approaches are almost identical when the number of samples is more than sufficient. We apply our approach to various low-level vision problems, e.g. high dynamic range imaging, motion edge detection, photometric stereo, image alignment and recovery, and show that our results outperform those obtained by the conventional nuclear norm rank minimization method.Comment: Accepted in Transactions on Pattern Analysis and Machine Intelligence (TPAMI). To appea

Examining Information Systems Infusion over the Routinization

Information systems (IS) infusion becomes important from the management perspective because organizations can leverage IS investment only at the IS infusion stage. The model for the stages of IS implementation explains that IS infusion can be achieved through IS routinization. This study examined how to achieve IS infusion through routinization based on application of the psychological empowerment theory and the unified theory of acceptance and use of technology (UTAUT), respectively. This study adds value to the IS literature by explaining how IS routinization leads to IS infusion and how their antecedents are different and related across the two stages. This study also provides guidance on how organizations can promote IS infusion beyond IS routinization, which then helps organizations leverage their IS investments