937 research outputs found
The relationship between the perception of distributed leadership in secondary schools and teachers' and teacher leaders' job satisfaction and organizational commitment
This study investigates the relation between distributed leadership, the cohesion of the leadership team, participative decision-making, context variables, and the organizational commitment and job satisfaction of teachers and teacher leaders. A questionnaire was administered to teachers and teacher leaders (n=1770) from 46 large secondary schools. Multiple regression analyses and path analyses revealed that the study variables explained significant variance in organizational commitment. The degree of explained variance for job satisfaction was considerably lower compared to organizational commitment. Most striking was that the cohesion of the leadership team and the amount of leadership support was strongly related to organizational commitment, and indirectly to job satisfaction. Decentralization of leadership functions was weakly related to organizational commitment and job satisfaction
Outer-Sphere Contributions to the Electronic Structure of Type Zero Copper Proteins
Bioinorganic canon states that active-site
thiolate coordination promotes rapid electron transfer (ET)
to and from type 1 copper proteins. In recent work, we have
found that copper ET sites in proteins also can be constructed
without thiolate ligation (called “type zero” sites). Here we
report multifrequency electron paramagnetic resonance
(EPR), magnetic circular dichroism (MCD), and nuclear
magnetic resonance (NMR) spectroscopic data together with
density functional theory (DFT) and spectroscopy-oriented
configuration interaction (SORCI) calculations for type zero Pseudomonas aeruginosa azurin variants. Wild-type (type 1) and type
zero copper centers experience virtually identical ligand fields. Moreover, O-donor covalency is enhanced in type zero centers
relative that in the C112D (type 2) protein. At the same time, N-donor covalency is reduced in a similar fashion to type 1
centers. QM/MM and SORCI calculations show that the electronic structures of type zero and type 2 are intimately linked to the
orientation and coordination mode of the carboxylate ligand, which in turn is influenced by outer-sphere hydrogen bonding
Statistical mechanics of voting
Decision procedures aggregating the preferences of multiple agents can
produce cycles and hence outcomes which have been described heuristically as
`chaotic'. We make this description precise by constructing an explicit
dynamical system from the agents' preferences and a voting rule. The dynamics
form a one dimensional statistical mechanics model; this suggests the use of
the topological entropy to quantify the complexity of the system. We formulate
natural political/social questions about the expected complexity of a voting
rule and degree of cohesion/diversity among agents in terms of random matrix
models---ensembles of statistical mechanics models---and compute quantitative
answers in some representative cases.Comment: 9 pages, plain TeX, 2 PostScript figures included with epsf.tex
(ignore the under/overfull \vbox error messages
The Complexity of Computing Minimal Unidirectional Covering Sets
Given a binary dominance relation on a set of alternatives, a common thread
in the social sciences is to identify subsets of alternatives that satisfy
certain notions of stability. Examples can be found in areas as diverse as
voting theory, game theory, and argumentation theory. Brandt and Fischer [BF08]
proved that it is NP-hard to decide whether an alternative is contained in some
inclusion-minimal upward or downward covering set. For both problems, we raise
this lower bound to the Theta_{2}^{p} level of the polynomial hierarchy and
provide a Sigma_{2}^{p} upper bound. Relatedly, we show that a variety of other
natural problems regarding minimal or minimum-size covering sets are hard or
complete for either of NP, coNP, and Theta_{2}^{p}. An important consequence of
our results is that neither minimal upward nor minimal downward covering sets
(even when guaranteed to exist) can be computed in polynomial time unless P=NP.
This sharply contrasts with Brandt and Fischer's result that minimal
bidirectional covering sets (i.e., sets that are both minimal upward and
minimal downward covering sets) are polynomial-time computable.Comment: 27 pages, 7 figure
Wnt signalling in adenomas of familial adenomatous polyposis patients
BACKGROUND: Epigenetic silencing of Wnt antagonists and expression changes in genes associated with Wnt response pathways occur
in early sporadic colorectal tumourigenesis, indicating that tumour cells are more sensitive to Wnt growth factors and respond
differently. In this study, we have investigated whether similar changes occur in key markers of the Wnt response pathways in the
genetic form of the disease, familial adenomatous polyposis (FAP).
METHODS: We investigated epigenetic and expression changes using pyrosequencing and real-time RT-PCR in samples from seven
patients without neoplasia, and matched normal and tumour tissues from 22 sporadic adenoma and 14 FAP patients.
RESULTS: We found that 17 out of 24 (71%) FAP adenomas were hypermethylated at sFRP1, compared with 20 out of 22 (91%) of
sporadic cases. This was reflected at the level of sFRP1 transcription, where 73% of FAP and 100% of sporadic cases were downregulated.
Increased expression levels of c-myc and FZD3 were less common in FAP (35 and 46% respectively) than sporadic tumours
(78 and 67% respectively).
CONCLUSION: Overall, the changes in expression and methylation were comparable, although the degree of change was generally
lower in the FAP adenomas. Molecular heterogeneity between multiple adenomas from individual FAP patients may reflect different
developmental fates for these premalignant tumours
Nurses' perceptions and experiences of communication in the operating theatre: a focus group interview
UNLABELLED: Nurses' perceptions and experiences of communication in the operating theatre: a focus group interview BACKGROUND: Communication programmes are well established in nurse education. The focus of programmes is most often on communicating with patients with less attention paid to inter-professional communication or skills essential for working in specialised settings. Although there are many anecdotal reports of communication within the operating theatre, there are few empirical studies. This paper explores communication behaviours for effective practice in the operating theatre as perceived by nurses and serves as a basis for developing training. METHODS: A focus group interview was conducted with seven experienced theatre nurses from a large London teaching hospital. The interview explored their perceptions of the key as well as unique features of effective communication skills in the operating theatre. Data was transcribed and thematically analysed until agreement was achieved by the two authors. RESULTS: There was largely consensus on the skills deemed necessary for effective practice including listening, clarity of speech and being polite. Significant influences on the nature of communication included conflict in role perception and organisational issues. Nurses were often expected to work outside of their role which either directly or indirectly created barriers for effective communication. Perceptions of a lack of collaborative team effort also influenced communication. CONCLUSION: Although fundamental communication skills were identified for effective practice in the operating theatre, there were significant barriers to their use because of confusion over clarity of roles (especially nurses' roles) and the implications for teamwork. Nurses were dissatisfied with several aspects of communication. Future studies should explore the breadth and depth of this dissatisfaction in other operating theatres, its impact on morale and importantly on patient safety. Interprofessional communication training for operating theatre staff based in part on the key issues identified in this study may help to create clarity in roles and focus attention on effective teamwork and promote clinical safety
The recording and characteristics of pulmonary rehabilitation in patients with COPD using The Health Information Network (THIN) primary care database
Pulmonary rehabilitation is recommended for patients with COPD to improve physical function, breathlessness and quality of life. Using The Health Information Network (THIN) primary care database in UK, we compared the demographic and clinical parameters of patients with COPD in relation to coding of pulmonary rehabilitation, and to investigate whether there is a survival benefit from pulmonary rehabilitation. We identified patients with COPD, diagnosed from 2004 and extracted information on demographics, pulmonary rehabilitation and clinical parameters using the relevant Read codes. Thirty six thousand one hundred and eighty nine patients diagnosed with COPD were included with a mean (SD) age of 67 (11) years, 53% were male and only 9.8% had a code related to either being assessed, referred, or completing pulmonary rehabilitation ever. Younger age at diagnosis, better socioeconomic status, worse dyspnoea score, current smoking, and higher comorbidities level are more likely to have a record of pulmonary rehabilitation. Of those with a recorded MRC of 3 or worse, only 2057 (21%) had a code of pulmonary rehabilitation. Survival analysis revealed that patients with coding for pulmonary rehabilitation were 22% (95% CI 0.69–0.88) less likely to die than those who had no coding. In UK THIN records, a substantial proportion of eligible patients with COPD have not had a coded pulmonary rehabilitation record. Survival was improved in those with PR record but coding for other COPD treatments were also better in this group. GP practices need to improve the coding for PR to highlight any unmet need locally
A Novel Microwave Sensor to Detect Specific Biomarkers in Human Cerebrospinal Fluid and Their Relationship to Cellular Ischemia During Thoracoabdominal Aortic Aneurysm Repair
Thoraco-abdominal aneurysms (TAAA) represents a particularly lethal vascular disease that without surgical repair carries a dismal prognosis. However, there is an inherent risk from
surgical repair of spinal cord ischaemia that can result in paraplegia. One method of reducing
this risk is cerebrospinal fluid (CSF) drainage. We believe that the CSF contains clinically
significant biomarkers that can indicate impending spinal cord ischaemia. This work
therefore presents a novel measurement method for proteins, namely albumin, as a precursor
to further work in this area. The work uses an interdigitated electrode (IDE) sensor and
shows that it is capable of detecting various concentrations of albumin (from 0 to 100 g/L)
with a high degree of repeatability at 200 MHz (R2 = 0.991) and 4 GHz (R2 = 0.975)
Assistive technology for hands-on learning by children with physical disabilities Perspectives or Theoretical Framework for the Research
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