Biomedical subjects

Michael M Mueller

Publications and source records attributed to Michael M Mueller.

5 recordsLinked to original sources

PubMed2004

Targeted gene knockout reveals a role in meiotic recombination for ZHP-3, a Zip3-related protein in Caenorhabditis elegans.

The meiotically expressed Zip3 protein is found conserved from Saccharomyces cerevisiae to humans. In baker's yeast, Zip3p has been implicated in synaptonemal complex (SC) formation, while little is known about the protein's function in multicellular organisms. We report here the successful targeted gene disruption of zhp-3 (K02B12.8), the ZIP3 homolog in the nematode Caenorhabditis elegans. Homozygous zhp-3 knockout worms show normal homologue pairing and SC formation. Also, the timing of appearance and the nuclear localization of the recombination protein Rad-51 seem normal in these animals, suggesting proper initiation of meiotic recombination by DNA double-strand breaks. However, the occurrence of univalents during diplotene indicates that C. elegans ZHP-3 protein is essential for reciprocal recombination between homologous chromosomes and thus chiasma formation. In the absence of ZHP-3, reciprocal recombination is abolished and double-strand breaks seem to be repaired via alternative pathways, leading to achiasmatic chromosomes and the occurrence of univalents during meiosis I. Green fluorescent protein-tagged C. elegans ZHP-3 forms lines between synapsed chromosomes and requires the SC for its proper localization.

Amino Acid Sequence↗

PubMed2004

Increasing variety of foods consumed by blending nonpreferred foods into preferred foods.

UNLABELLED: A treatment with differential or noncontingent reinforcement and nonremoval of the spoon increased the acceptance of one or two of 16 foods for 2 participants with severe food refusal. These differential levels of acceptance were demonstrated empirically in an ABAB design in which A was the presentation of the accepted (preferred) foods and B was the presentation of foods the participants refused (nonpreferred foods). Subsequently, we implemented a blending treatment that consisted of mixing (blending) nonpreferred foods into preferred foods in various ratios (e.g., 10% nonpreferred/90% preferred, 20% nonpreferred/80% preferred). We then presented nonpreferred foods that had been exposed to blending to determine if consumption of nonpreferred foods would increase following the blending treatment. We also conducted periodic reversals in which we presented nonpreferred foods that had not been exposed to the blending treatment. Following initial implementation of the blending treatment, consumption was high for nonpreferred foods that had been blended and low for nonpreferred foods that had not been blended. Consumption increased for all foods (i.e., foods that had been exposed to blending and foods that had not been exposed to blending) after seven or eight foods had been exposed to the blending treatment. Thus, the variety of foods consumed by the participants increased from one or two to 16. These results are discussed in terms of stimulus fading, conditioned food preferences, and escape extinction. DESCRIPTORS: conditioned food preferences, food refusal, negative reinforcement, stimulus fading

Child, Preschool↗

PubMed2003

Training parents to implement pediatric feeding protocols.

Four different multicomponent training packages were evaluated to increase the treatment integrity of parents implementing pediatric feeding protocols. In Study 1 we exposed 3 parents to a training package that consisted of written protocols (baseline), verbal instructions, therapist modeling, and rehearsal training. Results suggested that the package was successful in increasing treatment integrity of the feeding protocols to high levels. Study 2 investigated three different parent-training packages comprised of components used in Study 1. Two parents were exposed to written protocols, verbal instructions, and modeling; 2 parents were exposed to written protocols, verbal instructions, and rehearsal; and 2 parents were exposed to written protocols and verbal instructions. Results of Study 2 showed that each parent-training package produced very high treatment integrity. Follow-up data in the clinic and home for 5 participants suggested that the results were durable for up to 3 months. These results demonstrate a first step in the transfer and application of research findings into routine clinical practice because we evaluated several methods for training parents to implement behavioral feeding protocols, and we demonstrated that these methods resulted in high levels of treatment integrity in a controlled clinical setting.

Behavior Therapy↗

PubMed2003

Translating multiple assessment techniques into an intervention selection model for classrooms.

Translating current research to school-based clinical practice highlights issues not often encountered in laboratory settings. With the assistance of a consultant, teachers conducted functional analyses, brief multielement treatment comparisons, and controlled treatment evaluations under naturalistic conditions in the classroom. Teachers also provided input on treatment selection. Treatment integrity data collected throughout the study suggested that teachers implemented analyses and treatments with high integrity. The functional analysis outcomes combined with effectiveness and acceptability data led to the selection of interventions that reduced problem behavior in the classrooms for each of 3 children.

Behavior Therapy↗

PubMed2002

The influence of therapist attention on self-injury during a tangible condition.

This study investigated the effects of therapist attention on the self-injurious behavior (SIB) of a 6-year-old girl with developmental disabilities. After results of a functional analysis indicated that SIB was maintained by attention and tangible reinforcement, tangible conditions with and without contingent verbal attention were compared. Results suggested that the inclusion of verbal attention in a tangible condition may confound functional analysis outcomes for behavior that is maintained by attention.

Attention↗