Differential regulation of twitching motility and elastase production by Vfr in Pseudomonas aeruginosa

Vfr, a homolog of Escherichia coli cyclic AMP (cAMP) receptor protein, has been shown to regulate quorum sensing, exotoxin A production, and regA transcription in Pseudomonas aeruginosa. We identified a twitching motility-defective mutant that carries a transposon insertion in vfr and confirmed that vfr is required for twitching motility by construction of an independent allelic deletion-replacement mutant of vfr that exhibited the same phenotype, as well as by the restoration of normal twitching motility by complementation of these mutants with wild-type vfr. Vfr-null mutants exhibited severely reduced twitching motility with barely detectable levels of type IV pili, as well as loss of elastase production and altered pyocyanin production. We also identified reduced-twitching variants of quorum-sensing mutants (PAK lasl::Tc) with a spontaneous deletion in vfr (S. A. Beatson, C. B. Whitchurch, A. B. T. Semmler, and J. S. Mattick, J. Bacteriol., 184:3598-3604,2002), the net result of which was the loss of five residues (EQERS) from the putative cAMP-binding pocket or Vfr. This allele (VfrDeltaEQERS) was capable of restoring elastase and pyocyanin production to wild-type levels in vfr-null mutants but not their defects in twitching motility. Furthermore, structural analysis of Vfr and VfrDeltaEQERS in relation to E. coli CRP suggests that Vfr is capable of binding both cAMP and cyclic GMP whereas VfrDeltaEQERS is only capable of responding to cAMP. We suggest that Vfr controls twitching motility and quorum sensing via independent pathways in response to these different signals, bound by the same cyclic nucleotide monophosphate-binding pocket.

Working memory correlates of three symptom clusters in schizophrenia

This study was designed to examine whether discrete working memory deficits underlie positive, negative and disorganised symptoms of schizophrenia. Symptom dimension ratings were assigned to 52 outpatients with schizophrenia (ICD-10 criteria), using items drawn from the Positive and Negative Syndrome Scale (PANSS). Linear regression and correlational analyses were conducted to examine whether symptom dimension scores were related to performance on several tests of working memory function. Severity of negative symptoms correlated with reduced production of words during a verbal fluency task, impaired ability to hold letter and number sequences on-line and manipulate them Simultaneously, reduced performance during a dual task, and compromised visuospatial working memory under distraction-free conditions. Severity of disorganisation symptoms correlated with impaired visuospatial working memory under conditions of distraction, failure of inhibition during a verbal fluency task, perseverative responding on a test of set-shifting ability, and impaired ability to judge the veracity of simple declarative statements. Severity of positive symptoms was uncorrelated with performance on any of the measures examined. The present study provides evidence that the positive, negative and disorganised symptom dimensions of the PANSS constitute independent clusters, associated with unique patterns of working memory impairment. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

Organizational responses to a changing aid environment: the German Agency for Technical Cooperation (GTZ)

As a major European donor, German government development assistance faces a series of challenges. Recent political changes have raised expectations for demonstrable health outcomes as a result of German development assistance; there has been a deepened commitment to collaboration with other bilateral and multilateral donors; and partner countries are increasingly open to new approaches to development. German development assistance also reflects a new ethos of partnership and the shift to programmatic and sector based development approaches. At the same time, its particular organizational structure and administrative framework highlight the extent of structural and systems reforms required of donors by changing development relationships, and the tensions created in responding to these. This paper examines organizational changes within the German Agency for Technical Cooperation (Deutsche Gesellschaft fur Technische Zusammenarbeit) (GTZ), aimed at increasing its Regional, Sectoral, Managerial and Process competence as they affect health and related sectors. These include the decentralization of GTZ, the trend to integration of projects, the increasing focus on policy and health systems reform, increased inter-sectoral collaboration, changes in recruitment and training, new perspectives in planning and evaluation and the introduction of a quality management programme. Copyright (C) 2002 John Wiley Sons, Ltd.

Social rules for managing attempted interpersonal domination in the workplace: Influence of status and gender.

The present study utilized a social rules approach to investigate the relative influence of gender and status on managers' self-evaluations of their effectiveness in handling a dominating subordinate. In the first study 84 White middle-class participants identified the prescriptive and proscriptive rules for socially appropriate responding to a stimulus situation involving a pushy subordinate. Four rule sets were identified for female and male managers and subordinates, respectively. Rule-sets shared a number of common rules and showed some variation according to gender roles. In the second study, 91 White middle-class participants rated the individual rules for importance and also rated their personal and managerial effectiveness when responding to the stimulus situation using gender- and status-consistent and gender-and status-inconsistent response strategies. Both men and women rated the female gender and status- consistent strategy as most effective, and rated the status-inconsistent strategy as less effective than a gender-inconsistent response. Results were interpreted as providing more support for a situational gender-related theory of workplace behavior, rather than a traditional gender role perspective.

Microhabitat use by the rainbowfish Melanotaenia duboulayi in a subtropical Australian stream

Microhabitat use and feeding behavior of the rainbowfish Melanotaenia duboulayi (Castelnau) were investigated in a slow-flowing stream adjacent to riparian forest in south-eastern Queensland, Australia. Fish were more abundant in vegetated areas, but did not enter dense Vallisneria beds, where predators were observed. In sunny conditions shoals of juveniles occurred near the water surface feeding floating material on the surface, but larger fish tended to occur at the bottom near submerged vegetation, often utilizing the overhanging aquatic plant community as a refuge and food source. In the middle of the day, juveniles and small fish seemed to show behavioral thermoregulation at the surface in the warmest site. Under cloudy conditions, however, fish of all sizes preferred deeper water. The present study suggests that in still and sunny pools thermal change caused by sunlight influences the microhabitat choice of small fish. A field experiment using a kingfisher model implies that fish swimming at the surface could escape from aerial predators in sunlit conditions by responding to moving shadows, but could not do so under cloudy conditions.

The effectiveness of aphasia-friendly principles for printed health education materials for people with aphasia following stroke

Background: Provision of health information to people with aphasia is inadequate. Current practice in providing printed health education materials to people with aphasia does not routinely take into consideration their language and associated reading difficulties. Aims: This study aimed to investigate if people with aphasia can comprehend health information contained in printed health education materials and if the application of aphasia-friendly principles is effective in assisting them to comprehend health information. It was hypothesised that participants with aphasia would comprehend significantly more information from aphasia-friendly materials than from existing materials. Other aims included investigating if the effectiveness of the aphasia-friendly principles is related to aphasia severity, if people with aphasia are more confident in responding to health information questions after they have read the aphasia-friendly material, if they prefer to read the aphasia-friendly brochures, and if they prefer to read the brochure type that resulted in the greatest increase in their knowledge. Methods & Procedures: Twelve participants with mild to moderately severe aphasia were matched according to their reading abilities. A pre and post experimental design was employed with repeated measures ANOVA (p