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A learning module for nursing attempts to prepare nurses to understand philosophical inquiry and develop critical thinking skills. Teaching strategies used included exercises involving verbal disagreement and ambiguity and critical examination of publications. (Contains 42 references.) (SK)

Seventy-three caregivers of persons with Angelman syndrome completed the Aberrant Behavior checklist and Reiss Screen for Maladaptive Behavior. Responses indicate that 15q- Angelman syndrome is associated with problems such as lack of speech, over activity, restlessness, and eating and sleeping problems. Inappropriate laughter was only reported for 57 percent. (Contains references.) (Author/CR)

Problem behaviors of 38 individuals with Cri-du-Chat syndrome, 55 individuals with Prader Willi syndrome, and 21 individuals with Smith-Magenis syndrome were investigated. All three disorders were Associated with greater ratings of problem behaviors (besides eating abnormalities and sleep abnormalities) than comparison groups. (Author/CR)

Sedentary behaviour (SB) is associated with negative health outcomes and is prevalent post-stroke. This study explored SB after stroke from the perspective of stroke service staff. Qualitative mixed-methods study. Non-participant observations in two stroke services (England/Scotland) and semi-structured interviews with staff underpinned by the COM-B model of behaviour change. Observations were analysed thematically; interviews were analysed using the Framework approach. One hundred and thirty-two observation hours (October - December 2017), and 31 staff interviewed (January –June 2018). Four themes were identified: (1) Opportunities for staff to support stroke survivors to reduce SB; (2) Physical and psychological capability of staff to support stroke survivors to reduce SB; (3) Motivating factors influencing staff behaviour to support stroke survivors to reduce SB; (4) Staff suggestions for a future intervention to support stroke survivors to reduce SB. Staff are aware of the consequences of prolonged sitting but did not relate to SB. Explicit knowledge of SB was limited. Staff need training to support stroke survivors to reduce SB. Sedentary behaviour in the community was not reported to change markedly, highlighting the need to engage stroke survivors in movement from when capable in hospital, following through to home. Stroke survivor sedentary behaviour is influenced, directly and indirectly, by the actions and instructions of stroke service staff in the inpatient and community setting. The built and social environment, both in the inpatient and community settings, may limit opportunities for safe movement and can result in stroke survivors spending more time sedentary. Stroke service staff appreciate the benefit of encouraging stroke survivors to stand and move more, if it is safe for them to do so. Staff would be amenable to encourage stroke survivors to reduce sedentary behaviour, provided they have the knowledge and resources to equip them to support this. [ABSTRACT FROM AUTHOR]

Examines one mode of mathematical communication--student journal writing. The evaluation of the experimental use in one school of journal writing in mathematics demonstrates a link between language and mathematics and suggests a relationship between students' mathematical writings and their perceptions of mathematics. (Contains 21 references.) (Author/MDH)

Presented are practical methods exemplifying principles of assessment that involve minimal disruption of the instructional process and not impose additional work on the teacher. Informal assessment methods include annotated class lists and student work folios. Formal assessment methods include practical tests, student-constructed tests, and students' self-evaluation. (MDH)

We have developed an automated quench-flow microreactor which interfaces directly to an electrospray ionization (ES1) mass spectrometer. We have used this device in conjunction with ESI Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) to demonstrate the potential of this approach for studying the mechanistic details of enzyme reactions. For the model system chosen to test this device, namely, the pre-steady-state hydrolysis of p-nitrophenyl acetate by the enzyme chymotrypsin, the kinetic parameters obtained are in good agreement with those in the literature. To our knowledge, this is the first reported use of online quench-flow coupled with FrICR MS. Furthermore, we have exploited the power of FTICR MS to interrogate the quenched covalently bound enzyme intermediate using top-down fagmentafion. The accurate mass capabilities of FTICR MS permitted the nature of the intermediate to be assigned with high confidence. Electron capture dissociation (ECD) fragmentation allowed us to locate the intermediate to a five amino acid section of the protein-which includes the known catalytic residue, [Ser.sub.195]. This experimental approach, which uniquely can provide both kinetic and chemical details of enzyme mechanisms, is a potentially powerful tool for studies of enzyme catalysis. 10.1021/ac9026302

The Rcs phosphorelay is composed of RcsC, RcsD and the response regulator RcsB, and this signalling pathway has been implicated in virulence and biofilm formation in many enteric bacteria. It was previously shown that a mutation in rcsC resulted in defective biofilm formation in Escherichia coli [Ferrieres, L. & Clarke, D. J. (2003) Mol Microbiol 50, 1665-1682]. To identify the molecular mechanisms underlying the observed biofilm defect we carried out a screen looking for suppressor mutants that restored biofilm formation in the rcsC mutant background. One of the mutants was identified to be in rprA, a gene encoding a small RNA molecule that is involved in the post-transcriptional control of the alternative sigma factor, [[sigma].sup.s]. The expression of rprA is regulated by the Rcs phosphorelay, and there are elevated as levels present in the rcsC mutant due to the overexpression of rprA in this background. Using different approaches, we have established that the increase in as levels is responsible for the biofilm defect. Therefore, the Rcs phosphorelay is involved in maintaining appropriate levels of as during biofilm formation in E. coli. DOI 10.1099/mic.0.032722-0

The species that presently constitute the Burkholderia cepacia complex (Bcc) have multiple roles; they include soil and water saprophytes, bioremediators, and plant, animal and human pathogens. Since the first description of pathogenicity in the Bcc was based on sour skin rot of onion bulbs, this study returned to this plant host to investigate the onion-associated phenotype of the Bcc. Many Bcc isolates, which were previously considered to be non-mucoid, produced copious amounts of exopolysaccharide (EPS) when onion tissue was provided as the sole nutrient. EPS production was not species-specific, was observed in isolates from both clinical and environmental sources, and did not correlate with the ability to cause maceration of onion tissue. Chemical analysis suggested that the onion components responsible for EPS induction were primarily the carbohydrates sucrose, fructose and fructans. Additional sugars were investigated, and all alcohol sugars tested were able to induce EPS production, in particular mannitol and glucitol. To investigate the molecular basis for EPS biosynthesis, we focused on the highly conserved bce gene cluster thought to be involved in cepacian biosynthesis. We demonstrated induction of the bce gene cluster by mannitol, and found a clear correlation between the inability of representatives of the Burkholderia cenocepacia ET1 2 lineage to produce EPS and the presence of an 11 bp deletion within the bceB gene, which encodes a glycosyltransferase. Insertional inactivation of bceB in Burkholderia ambifaria AMMD results in loss of EPS production on sugar alcohol media. These novel and surprising insights into EPS biosynthesis highlight the metabolic potential of the Bcc and show that a potential virulence factor may not be detected by routine laboratory culture. Our results also highlight a potential hazard in the use of inhaled mannitol as an osmolyte to improve mucociliary clearance in individuals with cystic fibrosis.

The human-pathogenic yersiniae represent an ideal species group to study the evolution of highly virulent bacteria, with Yersinia pestis having emerged from the enteropathogen Y. pseudotuberculosis an estimated 20 000 years ago. Sequence data reveal that the Y. pestis genome is in the early stages of decay and contains hundreds of non-functioning pseudogenes, some of which may be important in the enteric lifestyle of Y. pseudotuberculosis. Bioinformatic analysis of pseudogenes from seven Y. pestis genome sequences identified rcsD as a gene disrupted early in the evolution of this organism. This phosphotransfer protein is part the of the Rcs phosphorelay, a two-component system present in the Enterobacteriaceae which has been shown to regulate the expression of capsular polysaccharide and other virulence determinants in several species including Escherichia coil and Salmonella. Using microarray analysis, we determined that the Y. pseudotuberculosis Rcs phosphorelay regulates the expression of 136 coding sequences, of which 60 o/0 are predicted to affect the cell envelope. Several putative virulence determinants were identified as being regulated by this phosphorelay, along with proteins involved in biofilm formation, motility, mammalian cell adhesion and stress survival. Phenotypic assays on defined mutants confirmed a role for the phosphorelay in these processes in both Y. pseudotuberculosis and Y. enterocolitica.

The RcsCDB phosphorelay was originally identified as the main regulator of colanic acid biosynthesis in Escherichia coli K-12. However, recent transcriptomic analyses have identified more than 150 genes belonging to the Rcs regulon, including yjbE, yjbF, yjbG and yjbH. These genes are clustered on the genome and oriented in the same direction but their function remains unknown. In this work it is shown that yjbE, yjbF, yjbG and yjbH are transcribed as a single operon and it is confirmed that the expression of this operon is controlled by the Rcs phosphorelay, in a manner that is dependent on the auxiliary regulatory protein RcsA. Interestingly, Northern blot analysis revealed that the amount of yjbE transcripts in the cell is higher than the amount of yjbEFGH transcripts and it is proposed that this differential expression is mediated by the presence of a strong stem-loop structure in theyjbE-yjbF intergenic region. Finally, evidence is provided that the overexpression of yjbEFGH affects colony morphology and leads to the production of an extracellular polysaccharide that binds Congo red and toluidine blue-O.

Photorhabdus is a genus of Gram-negative bacteria from the family Enterobacteriaceae. Members of Photorhabdus have a complex life cycle during which the bacterium has a pathogenic interaction with insect larvae whilst also maintaining a mutualistic relationship with nematodes from the family Heterorhabditidae. During growth in the insect, Photorhabdus bacteria produce a broad-spectrum antibiotic identified as 3,5-dihydroxy-4-isopropylstilbene (ST). The biochemical pathway responsible for the production of this antibiotic has not been characterized. In this report, a mutant strain of Photorhabdus luminescens subsp, laumondii TT01, BMM901, has been isolated, by transposon mutagenesis, that is unable to produce the ST antibiotic. Using in silico studies, feeding experiments and biochemical analyses, it is shown that the gene mutated in this strain, stlA, encodes phenylalanine ammonia-lyase (PAL). PAL catalyses the non-oxidative deamination of L-phenylalanine to trans-cinnamic acid and the enzyme is ubiquitous in plants, where it is involved in the production of phenylpropanoids such as lignin and phytoalexins. However, this is the first report of PAL activity in a member of the Proteobacteria.