1,156 research outputs found
Formality and informality in the summative assessment of motor vehicle apprentices: a case study
This article explores the interaction of formal and informal attributes of competenceâbased assessment. Specifically, it presents evidence from a small qualitative case study of summative assessment practices for competenceâbased qualifications within apprenticeships in the motor industry in England. The data are analysed through applying an adaptation of a framework for exploring the interplay of formality and informality in learning. This analysis reveals informal mentoring as a significant element which influences not only the process of assessment, but also its outcomes. We offer different possible interpretations of the data and their analysis, and conclude that, whichever interpretation is adopted, there appears to be a need for greater capacityâbuilding for assessors at a local level. This could acknowledge a more holistic role for assessors; recognise the importance of assessorsâ informal practices in the formal retention and achievement of apprentices; and enhance awareness of inequalities that may be reinforced by both informal and formal attributes of assessment practices
Silicon intercalation into the graphene-SiC interface
In this work we use LEEM, XPEEM and XPS to study how the excess Si at the
graphene-vacuum interface reorders itself at high temperatures. We show that
silicon deposited at room temperature onto multilayer graphene films grown on
the SiC(000[`1]) rapidly diffuses to the graphene-SiC interface when heated to
temperatures above 1020. In a sequence of depositions, we have been able to
intercalate ~ 6 ML of Si into the graphene-SiC interface.Comment: 6 pages, 8 figures, submitted to PR
Valence changes associated with the metal-insulator transition in BiLaNiO
Perovskite-type BiNiO is an insulating antiferromagnet in which a charge
disproportionation occurs at the Bi site. La substitution for Bi suppresses the
charge disproportionation and makes the system metallic. We have measured the
photoemission and x-ray absorption (XAS) spectra of BiLaNiO
to investigate how the electronic structure changes with La doping. From Ni
XAS, we observed an increase of the valence of Ni from 2+ toward 3+.
Combined with the core-level photoemission study, it was found that the average
valence of Bi remains and that the Ni valence behaves as , that is, La substitution results in hole doping at the Ni sites. In
the valence-band photoemission spectra, we observed a Fermi cutoff for ,
consistent with the metallic behavior of the La-doped compounds. The Ni
XAS, Ni core-level photoemission, and valence-band photoemission spectra
were analyzed by configuration-interaction cluster-model calculation, and the
spectral line shapes were found to be consistent with the gradual Ni
Ni valence change.Comment: 6 pages, 7 figure
Systemic inflammatory response syndrome after major abdominal surgery predicted by early upregulation of TLR4 and TLR5
OBJECTIVES
To study innate immune pathways in patients undergoing hepatopancreaticobiliary surgery to understand mechanisms leading to enhanced inflammatory responses and identifying biomarkers of adverse clinical consequences.
BACKGROUND
Patients undergoing major abdominal surgery are at risk of life-threatening systemic inflammatory response syndrome (SIRS) and sepsis. Early identification of at-risk patients would allow tailored postoperative care and improve survival.
METHODS
Two separate cohorts of patients undergoing major hepatopancreaticobiliary surgery were studied (combined nâ=â69). Bloods were taken preoperatively, on day 1 and day 2 postoperatively. Peripheral blood mononuclear cells and serum were separated and immune phenotype and function assessed ex vivo.
RESULTS
Early innate immune dysfunction was evident in 12 patients who subsequently developed SIRS (postoperative day 6) compared with 27 who did not, when no clinical evidence of SIRS was apparent (preoperatively or days 1 and 2). Serum interleukin (IL)-6 concentration and monocyte Toll-like receptor (TLR)/NF-ÎșB/IL-6 functional pathways were significantly upregulated and overactive in patients who developed SIRS (Pâ<â0.0001). Interferon α-mediated STAT1 phosphorylation was higher preoperatively in patients who developed SIRS. Increased TLR4 and TLR5 gene expression in whole blood was demonstrated in a separate validation cohort of 30 patients undergoing similar surgery. Expression of TLR4/5 on monocytes, particularly intermediate CD14CD16 monocytes, on day 1 or 2 predicted SIRS with accuracy 0.89 to 1.0 (areas under receiver operator curves).
CONCLUSIONS
These data demonstrate the mechanism for IL-6 overproduction in patients who develop postoperative SIRS and identify markers that predict patients at risk of SIRS 5 days before the onset of clinical signs
Isotope effects in underdoped cuprate superconductors: a quantum phenomenon
We show that the unusual doping dependence of the isotope effects on
transition temperature and zero temperature in - plane penetration depth
naturally follows from the doping driven 3D-2D crossover, the 2D quantum
superconductor to insulator transition (QSI) in the underdoped limit and the
change of the relative doping concentration upon isotope substitution. Close to
the QSI transition both, the isotope coefficient of transition temperature and
penetration depth approach the coefficient of the relative dopant
concentration, and its divergence sets the scale. These predictions are fully
consistent with the experimental data and imply that close to the underdoped
limit the unusual isotope effect on transition temperature and penetration
depth uncovers critical phenomena associated with the quantum superconductor to
insulator transition in two dimensions.Comment: 6 pages, 3 figure
Giant infrared intensity of the Peierls mode at the neutral-ionic phase transition
We present exact diagonalization results on a modified Peierls-Hubbard model
for the neutral-ionic phase transition. The ground state potential energy
surface and the infrared intensity of the Peierls mode point to a strong,
non-linear electron-phonon coupling, with effects that are dominated by the
proximity to the electronic instability rather than by electronic correlations.
The huge infrared intensity of the Peierls mode at the ferroelectric
transition is related to the temperature dependence of the dielectric constant
of mixed-stack organic crystals.Comment: 4 pages, 4 figure
Convection in colloidal suspensions with particle-concentration-dependent viscosity
The onset of thermal convection in a horizontal layer of a colloidal
suspension is investigated in terms of a continuum model for binary-fluid
mixtures where the viscosity depends on the local concentration of colloidal
particles. With an increasing difference between the viscosity at the warmer
and the colder boundary the threshold of convection is reduced in the range of
positive values of the separation ratio psi with the onset of stationary
convection as well as in the range of negative values of psi with an
oscillatory Hopf bifurcation. Additionally the convection rolls are shifted
downwards with respect to the center of the horizontal layer for stationary
convection (psi>0) and upwards for the Hopf bifurcation (psi<0).Comment: 8 pages, 6 figures, submitted to European Physical Journal
The significance of motivation in student-centred learning : a reflective case study
The theoretical underpinnings of student-centred learning suggest motivation to be an integral component. However, lack of clarification of what is involved in motivation in education often results in unchallenged assumptions that fail to recognise that what motivates some students may alienate others. This case study, using socio-cognitive motivational theory to analyse previously collected data, derives three fuzzy propositions which, collectively, suggest that motivation interacts with the whole cycle of episodes in the teachinglearning process. It argues that the development of the higherlevel cognitive competencies that are implied by the term, student-centred learning, must integrate motivational constructs such as goal orientation, volition, interest and attributions into pedagogical practices
Transgressing the moral economy: Wheelerism and management of the nationalised coal industry in Scotland
This article illuminates the links between managerial style and political economy in post-1945 Britain, and explores the origins of the 1984â1985 miners' strike, by examining in longer historical context the abrasive attitudes and policies of Albert Wheeler, Scottish Area Director of the National Coal Board (NCB). Wheeler built on an earlier emphasis on production and economic criteria, and his micro-management reflected pre-existing centralising tendencies in the industries. But he was innovative in one crucial aspect, transgressing the moral economy of the Scottish coalfield, which emphasised the value of economic security and changes by joint industrial agreement
Destruction of density-wave states by a pseudo-gap in high magnetic fields: application to (TMTSF)ClO
A model is presented for the destruction of density-wave states in
quasi-one-dimensional crystals by high magnetic fields. The model is consistent
with previously unexplained properties of the organic conductors
(TMTSF)ClO and (BEDT-TTF)MHg(SCN) (M=K,Rb,Tl). As the magnetic
field increases quasi-one-dimensional density-wave fluctuations increase,
producing a pseudo-gap in the electronic density of states near the transition
temperature. When the pseudo-gap becomes larger than the mean-field transition
temperature formation of a density-wave state is not possible.Comment: 4 pages, RevTeX, 2 figures in uuencoded compressed tar file. Small
changes to text and Figure 1. Final version to appear in Physical Review
Letter
- âŠ