Biomedical subjects

J Groeneweg

Publications and source records attributed to J Groeneweg.

14 recordsLinked to original sources

PubMed2006

Assessing the effects of stimulation versus microswitch-based programmes on indices of happiness of students with multiple disabilities.

BACKGROUND: Stimulation and microswitch-based programmes are considered main strategies to promote indices of happiness in students with multiple disabilities. However, only limited attempts have been made to assess the relative effects of the two programmes. This study conducted such an assessment with seven students with multiple disabilities. METHODS: The first four phases of the study served to: (1) provide the students with a systematic exposure to each of the programmes; and (2) measure the programmes' effects on indices of happiness by comparing them with baseline levels. The fifth phase served to compare the programmes with each other. RESULTS: The first four phases of the study showed that the microswitch-based programme produced a significant increase in indices of happiness for all seven students, and the stimulation programme produced a significant increase for six students. During the fifth phase of the study (i.e. when the two programmes were alternated), the microswitch-based programme promoted significantly higher indices of happiness than the stimulation programme for four of the seven students. CONCLUSIONS: Microswitch-based programmes might be deemed preferable to stimulation programmes because they can promote higher or comparable indices of happiness while promoting the acquisition of adaptive responses and self-determination.

Child↗

PubMed2005

Microswitch clusters to enhance adaptive responses and head control: a programme extension for three children with multiple disabilities.

PURPOSE: We assessed the possibility of extending adaptive responding and head control in three children with multiple disabilities through the use of microswitch clusters. METHOD: The children had previously learned to perform an adaptive hand response and to control head position during that response. They were now taught one or two new adaptive responses (foot lifting, leg touching, or vocalization) and to combine such responses with appropriate head position. Microswitch clusters served to ensure that an adaptive response was followed by positive stimulation only if it was combined with appropriate head position. RESULTS: The results were positive with the children learning the new adaptive responses and combining them with appropriate head position. This performance was maintained during two- or three-month post-intervention checks. During these checks, the children were also successful in using the old adaptive hand response with appropriate head position. CONCLUSIONS: The use of microswitch clusters was effective to extend the level of adaptive responding and enhance appropriate head position during this responding. This outcome, which indicates a successful technical replication and procedural extension of previous work in the area, has positive practical implications for educational and occupational programmes for children with multiple disabilities.

Child↗

PubMed2005

Further evaluation of microswitch clusters to enhance hand response and head control in persons with multiple disabilities.

This study was a further evaluation of microswitch clusters (combinations of two microswitches) to improve adaptive responding together with correct head position in two persons with multiple disabilities. The two participants were 19.7 and 6.6 yr. old and had profound intellectual disabilities, spastic tetraparesis, and visual impairment. They were initially taught an adaptive hand response that activated a pressure microswitch and produced favorite stimulation. Thereafter, their performance of the hand response produced favorite stimulation only when it was combined with a correct head position (detected through a mercury microswitch). Analysis showed that both participants increased the frequency of the hand response and, subsequently, the percentage of times they emitted this response in combination with correct (upright) head position. In essence, they were able to coordinate constructive occupation with exercise of appropriate posture. Performance was maintained at a 2-mo. postintervention check.

Adult↗

PubMed2004

Microswitch clusters to support responding and appropriate posture of students with multiple disabilities: three case evaluations.

PURPOSE: This study extended the evaluation of microswitch clusters to support responding and appropriate posture with three students with multiple disabilities. METHOD: Initially, a baseline level was established for the target response selected for each student. Then, Intervention I was implemented to increase the frequency of that response through the presentation of favourite stimuli. During Intervention II, the response was followed by favourite stimuli only if the microswitch cluster detected it in combination with appropriate posture. Post-intervention checks were carried out within 2 or 3 months from the end of Intervention II. RESULTS AND CONCLUSIONS: All students showed an increase in the frequency of the target response during Intervention I and in the percentage of times the response occurred in combination with appropriate posture during Intervention II. These changes lasted over time. The importance of microswitch clusters to enhance the performance of students with multiple disabilities was underlined.

Child↗

PubMed2004

Effects of automatically delivered stimulation on persons with multiple disabilities during their use of a stationary bicycle.

We assessed the effects of automatically delivered favorite stimulation on engagement and indices of happiness of two adults with multiple disabilities during their use of a stationary bicycle. The participants typically received four 5-min. sessions per day over a period of about 3.5 mo. Analysis showed that one participant had a significant increase in both those measures while the other participant had a significant increase in engagement during the intervention phases of the study (when the stimulation was present) as opposed to the baseline periods (when the stimulation did not occur). Implications of the findings are discussed.

Abnormalities, Multiple↗

PubMed2004

Assessing influence of stimulation on mood and aberrant behavior of persons with multiple disabilities during brief treadmill sessions.

This study assessed the influence of favorite stimuli on indices of happiness, e.g., smiling or excited vocalizations, and aberrant behavior, e.g., cantilena-like vocalizations or hand waving, of two young adults with multiple disabilities during 5-min. treadmill sessions. Several favorite stimuli, e.g., music and vibratory events, were available for the participants. The stimuli were presented in a rotation fashion during the sessions. To control for the effects of the stimuli, treadmill sessions without stimuli were also conducted. Analysis showed that the treadmill sessions with stimuli led to higher indices of happiness and lower aberrant behavior for both participants, compared to the treadmill sessions without stimuli.

Abnormalities, Multiple↗

PubMed2003

Microswitch clusters to enhance non-spastic response schemes with students with multiple disabilities.

PURPOSE: The study explored whether the use of microswitch clusters could enhance the performance of correct (non-spastic) response schemes by two students with multiple disabilities. METHOD: The study started with baseline on the two responses selected for each student. Then, intervention was implemented on the first response. This was followed by new baseline and intervention on the second response. Subsequently, intervention sessions on the two responses were alternated. Post-intervention checks were carried out over periods of 4 and 2.5 months. RESULTS AND CONCLUSIONS: Both students had an increase in correct response schemes and, conversely, a decline in spastic response schemes. The importance and practicality of microswitch clusters to enhance appropriate responding in students with multiple disabilities were discussed.

Adolescent↗

PubMed2003

Microswitch responding and awareness of contingency in persons with profound multiple disabilities.

This study was aimed at evaluating acquisition of responding on microswitches and awareness of contingency with 3 adolescents who had profound multiple disabilities. Their favorite stimulation was used contingently and noncontingently on their responding on microswitches. Analysis showed that they acquired and maintained high responding frequencies only with contingent stimulation, indicating that such responding reflected an awareness of contingency rather than stimulation-related arousal and activity. Implications of the findings are discussed.

Abnormalities, Multiple↗

PubMed2003

Using microswitches with persons who have profound multiple disabilities: evaluation of three cases.

This study evaluated the effectiveness of microswitch programs in promoting and maintaining responding of persons with profound multiple disabilities. Three participants were provided one or two microswitches. Their responding (microswitch activation) produced favorite stimuli. Analysis showed that all participants increased responding significantly, albeit with clear differences among them, during the intervention period of a few weeks. Two participants continued with the microswitch program in the daily context and had 3-mo. follow-up data similar to the intervention data. One participant did not continue with the program (reportedly because of inconsistent/low responding) and so did not receive a follow-up assessment. Links between responding and vigilance conditions and stereotypy are discussed.

Adolescent↗

PubMed2002

Evaluating the use of multiple microswitches and responses for children with multiple disabilities.

BACKGROUND: The present study assessed the feasibility of (1) establishing multiple microswitches and responses (some of which had not been used before) with two children with multiple disabilities, and (2) maintaining such microswitches and responses in the children's daily contexts. METHODS: The microswitches were introduced individually and then combined. During the last part of treatment and the follow-up, each child had three microswitches. RESULTS: The data show that both children learned to use all three available microswitches. Moreover, they retained fairly high levels of responding with the microswitches in their daily contexts during follow-up periods of 4 and 6 months. CONCLUSIONS: The personal and practical implications of these findings are discussed.

Adolescent↗

PubMed2002

Promoting functional activity engagement at appropriate times with people with multiple disabilities.

This study was aimed at teaching three persons with multiple disabilities to carry out functional activities at appropriate times independently. To this end, an electronic time system that produced vibratory alarms at preset times and a board with object-cues (instructions for the activities) were used. Data indicated that all three persons learned to perform the scheduled activities at the preset times independent of prompts from staff. Implications of the data and the combination of these activities with structured occupational periods were discussed.

Activities of Daily Living↗

PubMed2001

Assisted ambulation and activities for persons with profound multiple disabilities: assessing different ambulation levels.

Two participants with profound multiple disabilities were exposed to two occupational situations, which included 1-min. and 3-min. robot-assisted ambulation prior to each activity, respectively. Analysis showed participants' mean percentages of engagement time (session time they spent ambulating or manipulating objects) were well above 90 in both situations. The amount of deviant behavior was somewhat higher in the latter occupational situation for one participant. Implications of the findings were discussed.

Adult↗

PubMed1999

Maintenance energy demand and starvation recovery dynamics of Nitrosomonas europaea and Nitrobacter winogradskyi cultivated in a retentostat with complete biomass retention.

Nitrosomonas europaea and Nitrobacter winogradskyi (strain "Engel") were grown in ammonia-limited and nitrite-limited conditions, respectively, in a retentostat with complete biomass retention at 25 degrees C and pH 8. Fitting the retentostat biomass and oxygen consumption data of N. europaea and N. winogradskyi to the linear equation for substrate utilization resulted in up to eight-times-lower maintenance requirements compared to the maintenance energy demand (m) calculated from chemostat experiments. Independent of the growth rate at different stages of such a retention culture, the maximum specific oxygen consumption rate measured by mass spectrometric analysis of inlet and outlet gas oxygen content always amounted to approximately 45 micromol of O2 mg-1 of biomass-C x h-1 for both N. europaea and N. winogradskyi. When bacteria were starved for different time periods (up to 3 months), the spontaneous respiratory activity after an ammonia or nitrite pulse decreased with increasing duration of the previous starvation time period, but the observed decrease was many times faster for N. winogradskyi than for N. europaea. Likewise, the velocity of resuscitation decreased with extended time periods of starvation. The increase in oxygen consumption rates during resuscitation referred to the reviving population only, since in parallel no significant increase in the cell concentrations was detectable. N. europaea more readily recovers from starvation than N. winogradskyi, explaining the occasionally observed nitrite accumulation in the environment after ammonia becomes available. From chloramphenicol (100 microg x ml-1) inhibition experiments with N. winogradskyi, it has been concluded that energy-starved cells must have a lower protein turnover rate than nonstarved cells. As pointed out by Stein and Arp (L. Y. Stein and D. J. Arp, Appl. Environ. Microbiol. 64:1514-1521, 1998), nitrifying bacteria in soil have to cope with extremely low nutrient concentrations. Therefore, a chemostat is probably not a suitable tool for studying their physiological properties during a long-lasting nutrient shortage. In comparison with chemostats, retentostats offer a more realistic approach with respect to substrate provision and availability.

Ammonia↗

PubMedDate not supplied

Micro-switch programmes for students with multiple disabilities and minimal motor behaviour: assessing response acquisition and choice.

This study assessed (a) whether three girls with multiple disabilities and minimal motor behaviour could acquire pairs of responses taught through micro-switch-based programmes and (b) how the girls would eventually choose between those responses. In relation to the choice issue, a response-choice analysis was conducted to find out whether possible differences in performance rates for the two responses were due to the stimuli linked to them and/or to potential response preferences. Results indicated that all three girls succeeded in the acquisition of the two responses programmed for them and showed clear response choices. The choices seemed to be largely motivated by the stimuli linked to the responses. Implications of these findings were discussed, including the need to assess their generality and extend the scope of the work in this area.

Adolescent↗