2,039 research outputs found
Ethnicity, gender, social class and citizenship: comparative views from England and Sweden
Please note.
What follows is a summary of the second stage of ongoing research comparing the experiences of students and teachers of Citizenship Education in Sweden and England. A more complete and detailed version is expected to appear in a leading refereed journal later in the year, and a book proposal relating to all stages of the research is currently under consideration. While we await confirmation of the submitted proposals we cannot identify the journal or the prospective book publisher, but it is in those sources that more detailed and nuanced analysis and explanation will be located.
Introduction
The National Curriculum provision for Citizenship Education in England clearly requires that the subject must be taught throughout KS 3 and KS 4, with content indicated and a public examination available at KS4; until recently, there was also an A level. In Sweden - where Citizenship Education is not a separate subject - the content is vague and teachers’ interpretations of the assignment differ distinctively between the different schools and programmes. This contrasting provision between two countries which have both prided themselves on their welfare provision and policies of inclusive citizenship was considered ideal to examine the extent to which different approaches produce more or less aware, articulate and active citizens
Chemokines in depression in health and in inflammatory illness: a systematic review and meta-analysis
Inflammatory illness is associated with depression. Preclinical work has shown that chemokines are linked with peripheral–central crosstalk and may be important in mediating depressive behaviours. We sought to establish what evidence exists that differences in blood or cerebrospinal fluid chemokine concentration discriminate between individuals with depression and those without. Following PRISMA guidelines, we systematically searched Embase, PsycINFO and Medline databases. We included participants with physical illness for subgroup analysis, and excluded participants with comorbid psychiatric diagnoses. Seventy-three studies met the inclusion criteria for the meta-analysis. Individuals with depression had higher levels of blood CXCL4 and CXCL7 and lower levels of blood CCL4. Sensitivity analysis of studies with only physically healthy participants identified higher blood levels of CCL2, CCL3, CCL11, CXCL7 and CXCL8 and lower blood levels of CCL4. All other chemokines examined did not reveal significant differences (blood CCL5, CCL7, CXCL9, CXCL10 and cerebrospinal fluid CXCL8 and CXCL10). Analysis of the clinical utility of the effect size of plasma CXCL8 in healthy individuals found a negative predictive value 93.5%, given the population prevalence of depression of 10%. Overall, our meta-analysis finds evidence linking abnormalities of blood chemokines with depression in humans. Furthermore, we have demonstrated the possibility of classifying individuals with depression based on their inflammatory biomarker profile. Future research should explore putative mechanisms underlying this association, attempt to replicate existing findings in larger populations and aim to develop new diagnostic and therapeutic strategies
Mean lifetimes of V-particles and heavy mesons
A maximum-likelihood procedure for determining mean lifetimes of V-particles from cloud-chamber data is applied to samples taken from a group of 134 neutral V-particle decays. For 74 events which were consistent with a decay into a proton and a negative π-meson, a lifetime of (2.5±0.7)×10-10 sec is obtained. Dividing the data into "low Q" and "high Q" groups on the basis of the calculated energy release in the decay, a value of τL=(2.9±0.8)×10-10 sec is found for those cases with 0<~Q<~50 Mev and a value of τH=(1.6±0.5)×10-10 sec is found for those cases with 50<Q<~150 Mev. While no significant difference exists between these two values, the difference is greater than for other plausible division schemes which are considered.
A qualitative discussion of lifetimes is given for the case of 23 charged V-particle decays. For the charged V-particles these data suggest either a lifetime less than that of the neutral V-particles, provided the sample is homogeneous, or, more likely, an apparent average lifetime less than that of the neutral V-particles, if the sample is a mixture of two or more types of particles. The possibility that κ- and/or χ-mesons make up a part of these decays is considered
Vertex Sparsifiers: New Results from Old Techniques
Given a capacitated graph and a set of terminals ,
how should we produce a graph only on the terminals so that every
(multicommodity) flow between the terminals in could be supported in
with low congestion, and vice versa? (Such a graph is called a
flow-sparsifier for .) What if we want to be a "simple" graph? What if
we allow to be a convex combination of simple graphs?
Improving on results of Moitra [FOCS 2009] and Leighton and Moitra [STOC
2010], we give efficient algorithms for constructing: (a) a flow-sparsifier
that maintains congestion up to a factor of , where , (b) a convex combination of trees over the terminals that maintains
congestion up to a factor of , and (c) for a planar graph , a
convex combination of planar graphs that maintains congestion up to a constant
factor. This requires us to give a new algorithm for the 0-extension problem,
the first one in which the preimages of each terminal are connected in .
Moreover, this result extends to minor-closed families of graphs.
Our improved bounds immediately imply improved approximation guarantees for
several terminal-based cut and ordering problems.Comment: An extended abstract appears in the 13th International Workshop on
Approximation Algorithms for Combinatorial Optimization Problems (APPROX),
2010. Final version to appear in SIAM J. Computin
On the Number of Iterations for Dantzig-Wolfe Optimization and Packing-Covering Approximation Algorithms
We give a lower bound on the iteration complexity of a natural class of
Lagrangean-relaxation algorithms for approximately solving packing/covering
linear programs. We show that, given an input with random 0/1-constraints
on variables, with high probability, any such algorithm requires
iterations to compute a
-approximate solution, where is the width of the input.
The bound is tight for a range of the parameters .
The algorithms in the class include Dantzig-Wolfe decomposition, Benders'
decomposition, Lagrangean relaxation as developed by Held and Karp [1971] for
lower-bounding TSP, and many others (e.g. by Plotkin, Shmoys, and Tardos [1988]
and Grigoriadis and Khachiyan [1996]). To prove the bound, we use a discrepancy
argument to show an analogous lower bound on the support size of
-approximate mixed strategies for random two-player zero-sum
0/1-matrix games
The detection of tethered and rising bubbles using multiple acoustic techniques
There exists a range of acoustic techniques for characterizing bubble populations within liquids. Each technique has limitations, and complete characterization of a population requires the sequential or simultaneous use of several, so that the limitations of each find compensation in the others. Here, nine techniques are deployed using one experimental rig, and compared to determine how accurately and rapidly they can characterize given bubble populations. These are, specifically (i) two stationary bubbles attached to a wire; and (ii) injected, rising bubble
Kolb in de klas: vijf docenten in het hoger onderwijs onderzoeken de waarde van Kolbs leerstijlen voor hun eigen onderwijspraktijk
Deze bundel bevat de resultaten van vijf kortlopende onderzoeken door deelnemers aan de masteropleiding Teaching in Higher Education, allen docenten in het hoger onderwijs, naar de waarde van de leerstijlen van Kolb voor hun eigen lespraktijk. Uit de onderzoeken komt naar voren dat het onderwijsaanbod niet geheel bepaald wordt door de leerstijl van de docent, maar dat het zou kunnen zijn dat het wel deels hierdoor beïnvloed wordt. Ook zijn vier manieren geïdentificeerd waarop docenten rekening houden met individuele verschillen tussen studenten. Ten aanzien van het verrichten van dit type onderzoek blijkt een noodzaak om het vóórkomen van en voorkeuren voor bepaalde leerstijlen op verschillende manieren te meten en om zowel met kwalitatieve als kwantitatieve methoden te werken; daarbij kan de Chi-square goodness-of-fit test voor één groep, goede diensten bewijzen. Ook lijkt het dat aangetroffen verschillen in leerstijlen wel eens veroorzaakt zouden kunnen zijn tussen verschillen in wat en hoe men meet, en geen reflectie zijn van feitelijke verschillen in leerstijlen
The Geometry of Entanglement Sudden Death
In open quantum systems, entanglement can vanish faster than coherence. This
phenomenon is usually called sudden death of entanglement. In this paper sudden
death of entanglement is discussed from a geometrical point of view, in the
context of two qubits. A classification of possible scenarios is presented,
with important known examples classified. Theoretical and experimental
construction of other examples is suggested as well as large dimensional and
multipartite versions of the effect.Comment: 6 pages, 2 figures, references added, initial paragraph corrected,
sectioning adopted, some parts rewritten; accepted by New J. Phy
Does the Babcock--Leighton Mechanism Operate on the Sun?
The contribution of the Babcock-Leighton mechanism to the generation of the
Sun's poloidal magnetic field is estimated from sunspot data for three solar
cycles. Comparison of the derived quantities with the A-index of the
large-scale magnetic field suggests a positive answer to the question posed in
the title of this paper.Comment: 5 pages, 2 figures, to apper in Astronomy Letter
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