Intact flagellar motor of Borrelia burgdorferi revealed by cryo-electron tomography: evidence for stator ring curvature and rotor/C-ring assembly flexion.

The bacterial flagellar motor is a remarkable nanomachine that provides motility through flagellar rotation. Prior structural studies have revealed the stunning complexity of the purified rotor and C-ring assemblies from flagellar motors. In this study, we used high-throughput cryo-electron tomography and image analysis of intact Borrelia burgdorferi to produce a three-dimensional (3-D) model of the in situ flagellar motor without imposing rotational symmetry. Structural details of B. burgdorferi, including a layer of outer surface proteins, were clearly visible in the resulting 3-D reconstructions. By averaging the 3-D images of approximately 1,280 flagellar motors, a approximately 3.5-nm-resolution model of the stator and rotor structures was obtained. flgI transposon mutants lacked a torus-shaped structure attached to the flagellar rod, establishing the structural location of the spirochetal P ring. Treatment of intact organisms with the nonionic detergent NP-40 resulted in dissolution of the outermost portion of the motor structure and the C ring, providing insight into the in situ arrangement of the stator and rotor structures. Structural elements associated with the stator followed the curvature of the cytoplasmic membrane. The rotor and the C ring also exhibited angular flexion, resulting in a slight narrowing of both structures in the direction perpendicular to the cell axis. These results indicate an inherent flexibility in the rotor-stator interaction. The FliG switching and energizing component likely provides much of the flexibility needed to maintain the interaction between the curved stator and the relatively symmetrical rotor/C-ring assembly during flagellar rotation.

The impact of traditional psychiatric services and case management services on the functioning of people with schizophrenia: A cross-national study in Nova Scotia and Texas

The purpose of this study was to determine the impact of traditional psychiatric services with case management services on the functioning of people with schizophrenia. Traditional services were defined as routine clinic services consisting of medication follow-along, psychotherapy, and support services. Case management consisted of activities involved in linking, planning, and monitoring services for the outpatient client who has schizophrenia. The target population was adult schizophrenics who had been receiving outpatient clinic services for a minimum of six months. Structured interviews were conducted using standardized scales (e.g., Quality of Life, Self-Efficacy, and Brief Symptom Inventory) with 78 outpatient client volunteers from two sites: Nova Scotia (Canada) and Texas (USA). The researcher tested for differences in psychiatric symptomatology, recidivism, and quality of life for persons with schizophrenia receiving traditional psychiatric services in Nova Scotia and traditional plus case management services in Texas. Data were collected from the structured interviews and medical records review forms. Types of services were blocked into low and high levels of Intensity (frequency x minutes) and compared to determine the relative contribution of each. Finally, the role of clients' self-efficacy was tested as an intervening variable. Although the findings did not support the hypotheses in the direction anticipated, there were some interesting and useful results. From the Nova Scotia site, clients who received low levels of services were hospitalized less compared to the Texas site. The more psychotic a patient was the higher their involvement in medication follow-along and the more monitoring they received. The more psychotherapy received, the lower the reported satisfaction with social relationships. Of particular interest is the role that self-efficacy played in improved client outcomes. Although self-efficacy scores were related to improved functioning, the mechanism for this still needs to be clarified through subsequent research. ^

Booster Breaks in the workplace: Effects on employee stress

The current study examined the effects of a 15-minute daily physical activity break on the stress levels of white collar employees. An innovative group physical activity program, the Booster Break, was implemented in two worksites, both located in a large metropolitan area. One hundred sixteen participants were randomly assigned to one of three conditions; 43 participants were assigned to the Booster Break condition, 40 participants were assigned to an individual, computer-based physical activity condition, and 32 were assigned to a no-physical activity control condition. Self-report and objective measures were taken at baseline and after the completion of the intervention. There were no significant differences among conditions in perceived stress or blood pressure after the intervention. However, the data showed trends in the direction predicted with a decrease in perceived stress among Booster Break (change in perceived stress = -0.1) and computer prompt participants (change in perceived stress = -0.2) and an increase in perceived stress among the control group (change in perceived stress = 0.2). More research is recommended to fully understand the effects of worksite physical activity on stress.^