86 research outputs found
Peer assessment without assessment criteria
Peer assessment typically requires students to judge peers' work against assessment criteria. We tested an alternative approach in which students judged pairs of scripts against one another in the absence of assessment criteria. First year mathematics undergraduates (N = 194) sat a written test on conceptual understanding of multivariable calculus, then assessed their peers' responses using pairwise comparative judgement. Inter-rater reliability was investigated by randomly assigning the students to two groups and correlating the two groups' assessments. Validity was investigated by correlating the peers' assessments with (i) expert assessments, (ii) novice assessments, and (iii) marks from other module tests. We found high validity and inter-rater reliability, suggesting that the students performed well as peer assessors. We interpret the results in the light of survey and interview feedback, and discuss directions for further research into the benefits and drawbacks of peer assessment without assessment criteria
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The mechanical properties of amniotic membrane influence its effect as a biomaterial for ocular surface repair
The human amniotic membrane (AM) is a tissue of fetal origin and has proven to be clinically useful as
a biomaterial in the management of various ocular surface disorders including corneal stem cell
transplantation. However, its success rate displays a degree of clinical unpredictability. We suggest that
the measured variability inAMstiffness offers an explanation for the poor clinical reproducibility when
it is used as a substrate for stem cell expansion and transplantation. Corneal epithelial stem cells were
expanded upon AM samples possessing different mechanical stiffness. To investigate further the
importance of biological substrate stiffness on cell phenotype we replaced AM with type I collagen gels
of known stiffness. Substrate stiffness was measured using shear rheometry and surface topography
was characterized using scanning electron microscopy and atomic force microscopy. The
differentiation status of epithelial cells was examined using RT-PCR, immunohistochemistry and
Western blotting. The level of corneal stem cell differentiation was increased in cells expanded upon
AM with a high dynamic elastic shear modulus and cell expansion on type I collagen gels confirmed
that the level of corneal epithelial stem cell differentiation was related to the substrate’s mechanical
properties. In this paper we provide evidence to show that the preparatory method of AM for clinical
use can affect its mechanical properties and that these measured differences can influence the level of
differentiation within expanded corneal epithelial stem cells
The outsourcing of social care in Britain : what does it mean for voluntary sector workers?
While recent decades have witnessed a growth in the outsourcing of public services in Britain, the post-1997 UK Labour governments have sought to put in place mechanisms aimed at encouraging long-term collaborative contracting relationships marked by less reliance on cost-based competition. This article explores empirically how far these mechanisms have achieved their aims and thereby acted to protect the employment conditions of staff, and links this exploration to debates concerning the employment implications of organizational reforms within public sectors internationally. It concludes that in terms of bringing income security to the voluntary sector and stability to employment terms and conditions these efforts have been unsuccessful, and consequently casts doubts on more optimistic interpretations of the employment effects of organizational restructuring in the British public sector
Pollen exposure and hospitalization due to asthma exacerbations: daily time series in a European city.
Exposure to pollen can contribute to increased hospital admissions for asthma exacerbation. This study applied an ecological time series analysis to examine associations between atmospheric concentrations of different pollen types and the risk of hospitalization for asthma in London from 2005 to 2011. The analysis examined short-term associations between daily pollen counts and hospital admissions in the presence of seasonal and long-term patterns, and allowed for time lags between exposure and admission. Models were adjusted for temperature, precipitation, humidity, day of week, and air pollutants. Analyses revealed an association between daily counts (continuous) of grass pollen and adult hospital admissions for asthma in London, with a 4-5-day lag. When grass pollen concentrations were categorized into Met Office pollen 'alert' levels, 'very high' days (vs. 'low') were associated with increased admissions 2-5 days later, peaking at an incidence rate ratio of 1.46 (95%, CI 1.20-1.78) at 3 days. Increased admissions were also associated with 'high' versus 'low' pollen days at a 3-day lag. Results from tree pollen models were inconclusive and likely to have been affected by the shorter pollen seasons and consequent limited number of observation days with higher tree pollen concentrations. Future reductions in asthma hospitalizations may be achieved by better understanding of environmental risks, informing improved alert systems and supporting patients to take preventive measures
Challenges in mathematical cognition: a collaboratively-derived research agenda
This paper reports on a collaborative exercise designed to generate a coherent agenda for research on mathematical cognition. Following an established method, the exercise brought together 16 mathematical cognition researchers from across the fields of mathematics education, psychology and neuroscience. These participants engaged in a process in which they generated an initial list of research questions with the potential to significantly advance understanding of mathematical cognition, winnowed this list to a smaller set of priority questions, and refined the eventual questions to meet criteria related to clarity, specificity and practicability. The resulting list comprises 26 questions divided into six broad topic areas: elucidating the nature of mathematical thinking, mapping predictors and processes of competence development, charting developmental trajectories and their interactions, fostering conceptual understanding and procedural skill, designing effective interventions, and developing valid and reliable measures. In presenting these questions in this paper, we intend to support greater coherence in both investigation and reporting, to build a stronger base of information for consideration by policymakers, and to encourage researchers to take a consilient approach to addressing important challenges in mathematical cognition
Austerity, personalisation and the degradation of voluntary sector employment conditions
This qualitative study of two social care organisations, explores how public sector austerity and policies to personalise social care services through introducing individual budgets in the UK combine to reshape employment conditions. It further explores how these new market relations impact on staff morale and commitment. The individual case summaries reveal a remarkable degree of similarity in terms of employment outcomes, with social care workers experiencing an erosion of the standard employment relationship. Workers experience greater insecurity in areas of pay and conditions, working time, training and development, career prospects, along with work intensification. Worker morale appeared vulnerable as employees struggled to cope with worsening working conditions, but also expressed concerns with quality of care in an era of austerity
Conserved motifs reveal details of ancestry and structure in the small tim chaperones of the mitochondrial intermembrane space
The mitochondrial inner and outer membranes are composed of a variety of integral membrane proteins, assembled into the membranes posttranslationally. The small translocase of the inner mitochondrial membranes (TIMs) are a group of ∼10 kDa proteins that function as chaperones to ferry the imported proteins across the mitochondrial intermembrane space to the outer and inner membranes. In yeast, there are 5 small TIM proteins: Tim8, Tim9, Tim10, Tim12, and Tim13, with equivalent proteins reported in humans. Using hidden Markov models, we find that many eukaryotes have proteins equivalent to the Tim8 and Tim13 and the Tim9 and Tim10 subunits. Some eukaryotes provide "snapshots" of evolution, with a single protein showing the features of both Tim8 and Tim13, suggesting that a single progenitor gene has given rise to each of the small TIMs through duplication and modification. We show that no "Tim12" family of proteins exist, but rather that variant forms of the cognate small TIMs have been recently duplicated and modified to provide new functions: the yeast Tim12 is a modified form of Tim10, whereas in humans and some protists variant forms of Tim9, Tim8, and Tim13 are found instead. Sequence motif analysis reveals acidic residues conserved in the Tim10 substrate-binding tentacles, whereas more hydrophobic residues are found in the equivalent substrate-binding region of Tim13. The substrate-binding region of Tim10 and Tim13 represent structurally independent domains: when the acidic domain from Tim10 is attached to Tim13, the Tim8–Tim13¹⁰ complex becomes essential and the Tim9–Tim10 complex becomes dispensable. The conserved features in the Tim10 and Tim13 subunits provide distinct binding surfaces to accommodate the broad range of substrate proteins delivered to the mitochondrial inner and outer membranes
Challenges in mathematical cognition: a collaboratively-derived research agenda
This paper reports on a collaborative exercise designed to generate a coherent agenda for research on mathematical cognition. Following an established method, the exercise brought together 16 mathematical cognition researchers from across the fields of mathematics
education, psychology and neuroscience. These participants engaged in a process in which they generated an initial list of research questions with the potential to significantly advance understanding of mathematical cognition, winnowed this list to a smaller set of priority questions, and refined the eventual questions to meet criteria related to clarity, specificity and
practicability. The resulting list comprises 26 questions divided into six broad topic areas: elucidating the nature of mathematical thinking, mapping predictors and processes of competence development, charting developmental trajectories and their interactions, fostering conceptual understanding and procedural skill, designing effective interventions, and developing valid and reliable measures. In presenting these questions in this paper, we
intend to support greater coherence in both investigation and reporting, to build a stronger base of information for consideration by policymakers, and to encourage researchers to take a consilient approach to addressing important challenges in mathematical cognition
Improving the reach of vaccines to low-resource regions, with a needle-free vaccine delivery device and long-term thermostabilization
Dry-coated microprojections can deliver vaccine to abundant antigen-presenting cells in the skin and induce efficient immune responses and the dry-coated vaccines are expected to be thermostable at elevated temperatures. In this paper, we show that we have dramatically improved our previously reported gas-jet drying coating method and greatly increased the delivery efficiency of coating from patch to skin to from 6.5% to 32.5%, by both varying the coating parameters and removing the patch edge. Combined with our previous dose sparing report of influenza vaccine delivery in a mouse model, the results show that we now achieve equivalent protective immune responses as intramuscular injection (with the needle and syringe), but with only 1/30th of the actual dose. We also show that influenza vaccine coated microprojection patches are stable for at least 6 months at 23 degrees C. inducing comparable immunogenicity with freshly coated patches. The dry-coated microprojection patches thus have key and unique attributes in ultimately meeting the medical need in certain low-resource regions with low vaccine affordability and difficulty in maintaining "cold-chain" for vaccine storage and transport. (C) 2011 Elsevier B.V. All rights reserved
Challenges in Mathematical Cognition: A Collaboratively-Derived Research Agenda
This paper reports on a collaborative exercise designed to generate a coherent agenda for research on mathematical cognition. Following an established method, the exercise brought together 16 mathematical cognition researchers from across the fields of mathematics education,psychology and neuroscience. These participants engaged in a process in which they generated an initial list of research questions with the potential to significantly advance understanding of mathematical cognition, winnowed this list to a smaller set of priority questions, and refined the eventual questions to meet criteria related to clarity, specificity and practicability. The resulting list comprises 26 questions divided into sixbroad topic areas: elucidating the nature of mathematical thinking, mapping predictors and processes of competence development, charting developmental trajectories and their interactions, fostering conceptual understanding and procedural skill, designing effective interventions, and developing valid and reliable measures. In presenting these questions in this paper, we intend to support greater coherence in both investigation and reporting, to build a stronger base of information for consideration by policymakers, and to encourage researchers to take a consilient approach to addressing important challenges in mathematical cognition.</p
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