Volunteering for all? Explaining patterns of volunteering and identifying strategies to promote it

In policy terms in the UK, as elsewhere, volunteering has become increasingly associated with training for the workplace; a view which offers little to individuals ‘beyond’ the labour market because of age, disability or care commitments. Applying a neo-Durkheimian framework to a study of volunteers we examine how far the patterns of volunteering can be explained by the underlying institutional factors of strong and weak social regulation and social integration. This framework can offer insights into a range of possible policy levers for individuals rather than a ‘one size fits all’ emphasis on volunteering for personal gain for the workplace

Toward a social pedagogy of classroom group work

In any classroom, pupils will be drawn together for many purposes and we can refer to such within classroom contexts as 'groupings'. The teacher often creates these, and the way that they are set up, and how they are used for particular learning purposes. If the relationships between grouping size, interaction type and learning tasks in groups are planned strategically then learning experiences will be more effective. However, research suggests that the relationships between these elements are often unplanned and the 'social pedagogic' potential of classroom learning is therefore unrealised. In this paper we explore the notion of social pedagogy in relation to group work. It is argued that research and theory relevant to group work in classrooms is limited, and that a new approach, sensitive to group work under everyday classroom conditions is required. This paper identifies key features of a social pedagogy of classroom group work, which can inform effective group work in classrooms. It also describes the background to a current large scale UK project which has been set up to design with teachers a programme of high quality group work in classrooms at both primary and secondary phases. © 2003 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

Classroom contexts: Connections between class size and within class grouping

Background. There has been a vigorous debate for many years about the educational effects of class size differences, but even if differences have an impact on pupils' academic progress this still leaves unanswered important questions about what mediates the effect. Aims. This paper is informed by a classroom contextual perspective, and examines associations between class size and within class groupings (in terms of size and number of groups, adult presence in groups, and type of interaction between grouping members). Age differences in these relationships are also explored. Samples. The quantitative study is based on analysis of 3157 groupings, from 672 Reception, Year 2 and Year 5 classes in 331 schools. The qualitative study was based on 12 classes in 8 case study schools, and questionnaire responses completed by over 100 class teachers. Methods. Links between size of class and within class groupings were examined on the basis of a 'grouping mapping survey', in which teachers at a given time in the school day provided information on group size and number, adult presence, and type of interaction between pupils, and complementary qualitative analyses of data from teacher-completed questionnaires, and interviews. Results. The number of groups in a class increased with the size of the class. Over all three year groups, small classes had on average just over three groups, while large classes approached six groups. The size of groups in the class decreased with size of class. In class sizes over 25, pupils were more likely to be in a large group of 7-10, while in classes under 25 they were more likely to be in whole class groupings. Qualitative analyses showed that teachers felt that groups of 7-10 pupils had negative educational effects, for example, in terms of the quality and quantity of teaching and children's concentration and contribution in groups. Conclusions. Results suggest that the effects of class size can be best seen as through the size and number of groups, which will then have implications for learning experiences. So while debate about size of class has often been in terms of reduced size of class resulting in pupil academic gains, it is also important educationally to consider within class grouping size and number, and their effects.link_to_subscribed_fulltex

Magnetic field induced non-Fermi liquid to Fermi liquid crossover at the quantum critical point of YbCu5−x_{5-x}Aux_{x}

The temperature (T) dependence of the muon and $^{63}$Cu nuclear spin-lattice relaxation rates $1/T_1$ in YbCu4.4Au0.6 is reported over nearly four decades. It is shown that for $T\to 0$ $1/T_1$ diverges following the behaviour predicted by the self-consistent renormalization (SCR) theory developed by Moriya for a ferromagnetic quantum critical point. On the other hand, the static uniform susceptibility $\chi_s$ is observed to diverge as $T^{-2/3}$ and $1/T_1T\propto \chi_s^2$, a behaviour which is not accounted for by SCR theory. The application of a magnetic field $H$ is observed to induce a crossover to a Fermi liquid behaviour and for $T\to 0$ $1/T_1$ is found to obey the scaling law $1/T_1(H)= 1/T_1(0)[1+(\mu_BH/k_BT)^2]^{-1}$.Comment: 4 pages, 4 figure

Hydraulic flow through a channel contraction: multiple steady states

We have investigated shallow water flows through a channel with a contraction by experimental and theoretical means. The horizontal channel consists of a sluice gate and an upstream channel of constant width $b_0$ ending in a linear contraction of minimum width $b_c$. Experimentally, we observe upstream steady and moving bores/shocks, and oblique waves in the contraction, as single and multiple steady states, as well as a steady reservoir with a complex hydraulic jump in the contraction occurring in a small section of the $b_c/b_0$ and Froude number parameter plane. One-dimensional hydraulic theory provides a comprehensive leading-order approximation, in which a turbulent frictional parametrization is used to achieve quantitative agreement. An analytical and numerical analysis is given for two-dimensional supercritical shallow water flows. It shows that the one-dimensional hydraulic analysis for inviscid flows away from hydraulic jumps holds surprisingly well, even though the two-dimensional oblique hydraulic jump patterns can show large variations across the contraction channel

Dictyostelium discoideum as a model for the evaluation of teratogenic compounds

Before new chemicals can be put on the market, they must be evaluated for toxicological safety. Evaluating the safety of new chemicals, for either medical, cosmetic or environmental application, is tightly regulated by worldwide legislation. A critical aspect of toxicity evaluation is developmental and reproductive toxicity (DART) testing. Traditionally, DART testing has been conducted in vivo in mammalian model systems. In fact, current EU DART testing guidelines accounts for the majority of animals used and the financial costs of new compound compliance testing. Therefore, because of the need to reduce the financial and animal costs associated with DART testing, there is a growing demand for new alternative model systems for toxicity evaluation. Dictyostelium discoideum is a eukaryotic amoeba which due to its unique developmental cycle has the potential to serve as a non-animal alternative model in DART testing. However, for a new alternative model to be proven effective it must allow for high-throughput screening, whilst maintaining biological complexity; allowing developmental toxicity results to be predictive of mammalian systems. To address these concerns, we developed new high-throughput D. discoideum growth and developmental toxicity assays. We use the assays to characterise toxicity across a broad range of test compounds, thereby revealing a significant relationship between D. discoideum and mammalian toxicity values. Our data demonstrates that D. discoideum has the biological complexity necessary to be predictive of mammalian toxicity. We further assess whether D. discoideum could be used to genetically characterise developmentally toxic compounds. Using next generation functional genomic screens, we show how the developmentally toxicity compounds, lithium and VPA can be globally genetically phenotyped. Using this genetic phenotyping approach, we were also able to identify the biological targets and processes that mediate lithium and VPA toxicity. Together, these studies illustrate the potential of D. discoideum to be developed as a new alternative model in DART testing

Role of the Mitochondrion in Programmed Necrosis

In contrast to the “programmed” nature of apoptosis and autophagy, necrotic cell death has always been believed to be a random, uncontrolled process that leads to the “accidental” death of the cell. This dogma, however, is being challenged and the concept of necrosis also being “programmed” is gaining ground. In particular, mitochondria appear to play a pivotal role in the mediation of programmed necrosis. The purpose of this review, therefore, is to appraise the current concepts regarding the signaling mechanisms of programmed necrosis, with specific attention to the contribution of mitochondria to this process

Anomalously slow spin dynamics and short-range correlations in the quantum spin ice systems Yb2Ti2O7 and Yb2Sn2O7

We report a positive muon spin relaxation and rotation (\muSR) study of the quantum spin ice materials Yb2Ti2O7 and Yb2Sn2O7 focusing on the low field response. In agreement with earlier reports, data recorded in small longitudinal fields evidence anomalously slow spin dynamics in the microsecond range below the temperature T_c at which the specific heat displays an intense peak, namely T_c = 0.24 K and 0.15 K, respectively, for the two systems. We found that slow dynamics extends above T_c up to at least 0.7 K for both compounds. The conventional dynamical Gaussian Kubo-Toyabe model describes the \muSR spectra recorded above T_c. At lower temperatures a published analytical extension of the Gaussian Kubo-Toyabe model provides a good description, consistent with the existence of short-range magnetic correlations. While the physical response of the two systems is qualitatively the same, Yb2Ti2O7 exhibits a much larger local magnetic susceptibility than Yb2Sn2O7 below T_c. Considering previously reported ac susceptibility, neutron scattering and \muSR results, we suggest the existence of anomalously slow spin dynamics to be a common physical property of pyrochlore magnetic materials. The possibility of molecular spin substructures to be associated to the slow dynamics and therefore the short-range correlations is mentioned. The slow spin dynamics observed under field does not exclude the presence of much faster dynamics detected in extremely low or zero field.Comment: 11 pages, 10 figure