Biomedical subjects

John Austin

Publications and source records attributed to John Austin.

9 recordsLinked to original sources

PubMed2006

Proteomic analysis of Campylobacter jejuni 11168 biofilms reveals a role for the motility complex in biofilm formation.

Campylobacter jejuni remains the leading cause of bacterial gastroenteritis in developed countries, and yet little is known concerning the mechanisms by which this fastidious organism survives within its environment. We have demonstrated that C. jejuni 11168 can form biofilms on a variety of surfaces. Proteomic analyses of planktonic and biofilm-grown cells demonstrated differences in protein expression profiles between the two growth modes. Proteins involved in the motility complex, including the flagellins (FlaA, FlaB), the filament cap (FliD), the basal body (FlgG, FlgG2), and the chemotactic protein (CheA), all exhibited higher levels of expression in biofilms than found in stationary-phase planktonic cells. Additional proteins with enhanced expression included those involved in the general (GroEL, GroES) and oxidative (Tpx, Ahp) stress responses, two known adhesins (Peb1, FlaC), and proteins involved in biosynthesis, energy generation, and catabolic functions. An aflagellate flhA mutant not only lost the ability to attach to a solid matrix and form a biofilm but could no longer form a pellicle at the air-liquid interface of a liquid culture. Insertional inactivation of genes that affect the flagellar filament (fliA, flaA, flaB, flaG) or the expression of the cell adhesin (flaC) also resulted in a delay in pellicle formation. These findings demonstrate that the flagellar motility complex plays a crucial role in the initial attachment of C. jejuni 11168 to solid surfaces during biofilm formation as well as in the cell-to-cell interactions required for pellicle formation. Continued expression of the motility complex in mature biofilms is unusual and suggests a role for the flagellar apparatus in the biofilm phenotype.

Bacterial Adhesion↗

PubMed2006

The effects of prompting and feedback on drivers' stopping at stop signs.

Complete stops at a high-traffic intersection on the campus of a public university were increased with a prompting and consequence intervention. Data were collected at two opposing stop signs (Stop A and Stop B); however, the intervention was implemented only at Stop A. During the intervention, a volunteer stood next to Stop A holding a poster that read, "Please Stop--I Care," with "Thank You For Stopping" on the reverse side. The poster was held by the volunteer so that drivers approaching Stop A could read the sign. Drivers approaching Stop B could see the volunteer but could not read the sign. When vehicles approaching Stop A made a complete stop, the volunteer flashed the "thank you" side of the poster to the driver. The strategy was evaluated using a multielement design. The intervention increased stops completed at Stop A from a baseline average of 13% to an intervention average of 52%. Stop B also showed improved stopping, from a baseline average of 6% to an intervention average of 28%. Data showed no relation between complete stops made and the drivers' use of turn signals and safety belts.

Attention↗

PubMed2005

Using task clarification, graphic feedback, and verbal feedback to increase closing-task completion in a privately owned restaurant.

An informant functional assessment was used to evaluate closing-task completion by servers and dishwashers at a restaurant. Based on the functional assessment results, an intervention consisting of task clarification, posted graphic feedback, and verbal feedback was implemented and evaluated with a multiple baseline design across two groups of employees. Results showed an increase of 15% and 38% in task completion for the two groups.

Adult↗

PubMed2005

The effects of a seatbelt-gearshift delay prompt on the seatbelt use of motorists who do not regularly wear seatbelts.

A seatbelt-gearshift delay was evaluated in two U.S. and three Canadian vehicles using a reversal design. The seatbelt-gearshift delay required unbelted drivers either to buckle their seatbelts or to wait a specified time before they could put the vehicle in gear. After collecting behavioral prebaseline data, a data logger was installed in all five vehicles to collect automated data on seatbelt use. Next the seatbelt-gearshift delay was introduced. The results showed that the delay increased all 5 drivers' seatbelt use, and that the duration of the delay that produced relatively consistent seatbelt use varied across drivers from 5 to 20 s. When the device was deactivated in four of the five vehicles, behavior returned to baseline levels.

Accidents, Traffic↗

PubMed2004

Agreement of function across methods used in school-based functional assessment with preadolescent and adolescent students.

As we begin to apply functional assessment procedures in mainstream educational settings, there is a need to explore options for identifying behavior function that are not only effective but efficient and practical for school personnel to employ. Attempts to simplify the functional assessment process are evidenced by the development of informant assessment measures (e.g., interviews, rating scales). In this study, the agreement (i.e., on relative rankings and primary function) across sources of information regarding behavior function was examined for 19 students in a middle school setting. These measures included teacher ratings, student ratings, student interviews, observer ratings, and conditional probabilities. In addition, for 1 student, whether information obtained through these sources was consistent with that obtained through a brief analog analysis of function was examined. Results indicated low agreement regarding rank order of behavior function and on primary function across all sources of information.

Adolescent↗

PubMed2004

Screening major binding sites on human serum albumin by affinity capillary electrophoresis.

A screening method is described for determining whether a drug or small solute has significant interactions at the two major binding sites on human serum albumin (HSA). This method uses affinity capillary electrophoresis (ACE) to perform a mobility shift assay, where the solute of interest is injected in both the presence of pH 7.4, 0.067 M phosphate buffer, and the same buffer containing a known concentration of HSA. Dextran is also used in the running buffer to adjust the mobility of HSA. Two types of modified HSA are used in this assay. The first is modified with 2-hydroxy-5-nitrobenzyl bromide (HNB), which selectively blocks HSA's warfarin-azapropazone site. The second type of HSA is modified with tetranitromethane (TNM), which decreases binding at the indole-benzodiazepine site. By comparing the mobility of a solute in the presence of these two modified forms of HSA vs normal HSA, it is possible to detect solute interactions at these binding sites. This approach is illustrated using warfarin and ibuprofen as examples of test solutes.

2-Hydroxy-5-nitrobenzyl Bromide↗

PubMed2004

The effects of conducting behavioral observations on the behavior of the observer.

Behavior-analytic approaches to occupational safety are often effective for improving safety in organizations, and have been successful in a wide variety of settings. The effects of these safety processes are thought to arise primarily from the behavioral observation process and the delivery of feedback. Typically, supervisors or employee observers involved in behavioral safety implementations conduct observations. The present study was an attempt to assess the effects of conducting observations on an observer's safety performance. An ABC multiple baseline counterbalanced across two sets of behaviors was conducted in a simulated office. The target behaviors involved knee and back positions during lifts; back, shoulder, and feet positions while sitting; neck and wrist positions while typing; and neck position during phone use. Substantial improvements in safety performance occurred after participants conducted observations on a videotape of a confederate's performance. The possible behavioral functions responsible for this change, and the implications of these findings for applied settings, are discussed.

Female↗

PubMed2002

Identification of drug-binding sites on human serum albumin using affinity capillary electrophoresis and chemically modified proteins as buffer additives.

A technique based on affinity capillary electrophoresis (ACE) and chemically modified proteins was used to screen the binding sites of various drugs on human serum albumin (HSA). This involved using HSA as a buffer additive, following the site-selective modification of this protein at two residues (tryptophan 214 or tyrosine 411) located in its major binding regions. The migration times of four compounds (warfarin, ibuprofen, suprofen and flurbiprofen) were measured in the presence of normal or modified HSA. These times were then compared and the mobility shifts observed with the modified proteins were used to identify the binding regions of each injected solute on HSA. Items considered in optimizing this assay included the concentration of protein placed into the running buffer, the reagents used to modify HSA, and the use of dextran as a secondary additive to adjust protein mobility. The results of this method showed good agreement with those of previous reports. The advantages and disadvantages of this approach are examined, as well as its possible extension to other solutes.

2-Hydroxy-5-nitrobenzyl Bromide↗

PubMed2002

Community mental health care: documenting the role of the nurse.

In Australia, the process of deinstitutionalisation has resulted in the closure or downsizing of many large stand-alone psychiatric hospitals. The aim of modern community mental health care is to provide treatment and rehabilitation for people, who have a mental illness, in their local community. This aim is supported by the Australian National Mental Health Strategy that outlines the importance of health professionals, carers, and consumers working together to obtain the best therapeutic outcomes. This study was undertaken to obtain information regarding the current role of the community mental health nurse (CMHN). All community mental health nurses working in the Adult Program at the Directorate of Mental Health Services, Fremantle Hospital and Health Service in Western Australia participated in the study. The study was completed in November 2000. The results showed that the CMHNs' role focused on six main areas. These areas included the day-to-day management of clients, working with carers and their families; crisis work for both existing andfirst time contacts; as well as liaison and advocacy work. Thefinding of this study demonstrate CMHN's work most often with acutely ill and psychotic patients and theirfamilies. Therefore, CMHN's play a pivotal role in promoting and sustaining the philosophy of community mental health care. In addition, the liaison work within the community completed by CMHN's is vital to address the mental health needs of the community and to reduce the stigma associated with mental illness. The documentedfindings of this study provide challengesfor thefurther expansion of the CMHN's role and the development of best practice initiatives in community mental health care.

Adult↗