Using 'approach goals' to increase student motivation for independent study: a randomised controlled field trial

Motivation has an important influence on the extent to which students engage in study. Reported here is a large-scale randomised controlled trial comparing the effect of Mastery-Approach (MAp) goals, which focus on development of task mastery, and Performance-Approach (PAp) goals, which focus on demonstration of competence. The achievement goals were embedded within an online learning platform for students aged 16-18 years in England. In a sample of 1,791 students, intention to treat analysis showed students randomly allocated to receive the MAp goals (treatment group 1) engaged in more effortful learning activities on the platform, compared to students assigned to receive the PAp goals (treatment group 2) or no achievement goal messages (control group). The PAp messages had no significant impact on student effort. The research addresses a need for more ecologically valid causal evidence on achievement goal theory and has direct implications for educators managing remote learning

A treatment of the exclusion volume term in the inhomogeneous Poisson-Boltzmann theory for an ion-dipole mixture

The exclusion volume approximation in the Poisson-Boltzmann theory is analysed at the mean field level for an ion-dipole mixture against a plane, uniformly charged hard wall. An earlier treatment is extended to take account of the deviation of the exclusion volume term from the uncharged wall – uncharged hard sphere distribution function. Preliminary numerical results are presented for a 1:1 electrolyte at c = 1.0 mole/dm³ with unequal ion and dipole sizes.Наближення виключеного об’єму в теорії Пуассона-Больцмана аналізується на рівні середнього поля для іонно-дипольної суміші біля плоскої, однорідно зарядженої твердої стінки. Попередній розгляд є розширений до врахування відхилення члена виключеного об’єму від функції розподілу незаряджена стінка – незаряджена тверда сфера. Попередні числові результати є представлені для електроліту 1:1 при c=1.0 моль/дм³ з нерівними розмірами іонів і диполів

How Multivalency controls Ionic Criticality

To understand how multivalency influences the reduced critical temperatures, Tce (z), and densities, roce (z), of z : 1 ionic fluids, we study equisized hard-sphere models with z = 1-3. Following Debye, Hueckel and Bjerrum, association into ion clusters is treated with, also, ionic solvation and excluded volume. In good accord with simulations but contradicting integral-equation and field theories, Tce falls when z increases while roce rises steeply: that 80-90% of the ions are bound in clusters near T_c serves to explain these trends. For z \neq 1 interphase Galvani potentials arise and are evaluated.Comment: 4 pages, 4 figure

The Urgency of Critical Theory Today: Towards Optimism and Renewal in a Neoliberal World

This article takes the form of a critical conversation between three generations of critical theorists, examining the role of critical theory in the neoliberal academy: does this sort of intellectual project still have a place in an academic and educational system that tends to favour empirical research and policy-driven projects? Through a discussion of the relationship between critical theory and power, privilege, and positionality, the article addresses the ongoing urgency of such intellectual activities in the present context. The dialogue between the three participants acknowledges critical theory’s historical, and continuing, fragility within the university, while elucidating the ways that it can provide a vehicle for challenging dominant forms of power. In doing so, this cross-generational exchange demonstrates that critical theory remains a vital space of rebellion, optimism, and social change

Charge Oscillations in Debye-Hueckel Theory

The recent generalized Debye-Hueckel (GDH) theory is applied to the calculation of the charge-charge correlation function G_{ZZ}(r). The resulting expression satisfies both (i) the charge neutrality condition and (ii) the Stillinger-Lovett second-moment condition for all T and rho_N, the overall ion density, and (iii) exhibits charge oscillations for densities above a "Kirkwood line" in the (rho_N,T) plane. This corrects the normally assumed DH correlations, and, when combined with the GDH analysis of the density correlations, leaves the GDH theory as the only complete description of ionic correlation functions, as judged by (i)-(iii), (iv) exact low-density (rho_N,T) variation, and (v) reasonable behavior near criticality.Comment: 6 pages, EuroPhys.sty (now available on archive), 1 eps figur

Correlation functions in ionic liquid at coexistence with ionic crystal. Results of the Brazovskii-type field theory

Correlation functions in the restricted primitive model are calculated within a field-theoretic approach in the one-loop self-consistent Hartree approximation. The correlation functions exhibit damped oscillatory behavior as found before in the Gaussian approximation [Ciach at. al., J. Chem. Phys. {\bf 118}, 3702 (2003)]. The fluctuation contribution leads to a renormalization of both the amplitude and the decay length of the correlation functions. The renormalized quantities show qualitatively different behavior than their mean-field (MF) counterparts. While the amplitude and the decay length both diverge in MF when the $\lambda$-line is approached, the renormalized quantities remain of order of unity in the same dimensionless units down to the coexistence with the ionic crystal. Along the line of the phase transition the decay length and the period of oscillations are independent of density, and their values in units of the diameter of the ions are $\alpha_0^{-1}\approx 1$ and $2\pi/\alpha_1\approx 2.8$ respectively.Comment: 21 pages including 9 figure

Field-theoretic description of ionic crystallization in the restricted primitive model

Effects of charge-density fluctuations on a phase behavior of the restricted primitive model (RPM) are studied within a field-theoretic formalism. We focus on a $\lambda$-line of continuous transitions between charge-ordered and charge-disordered phases that is observed in several mean-field (MF) theories, but is absent in simulation results. In our study the RPM is reduced to a $\phi^6$ theory, and a fluctuation contribution to a grand thermodynamic potential is obtained by generalizing the Brazovskii approach. We find that in a presence of fluctuations the $\lambda$-line disappears. Instead, a fluctuation-induced first-order transition to a charge-ordered phase appears in the same region of a phase diagram, where the liquid -- ionic-crystal transition is obtained in simulations. Our results indicate that the charge-ordered phase should be identified with an ionic crystal.Comment: 31 pages, 10 figure

Mesoscopic theory for size- and charge- asymmetric ionic systems. I. Case of extreme asymmetry

A mesoscopic theory for the primitive model of ionic systems is developed for arbitrary size, $\lambda=\sigma_+/\sigma_-$, and charge, $Z=e_+/|e_-|$, asymmetry. Our theory is an extension of the theory we developed earlier for the restricted primitive model. The case of extreme asymmetries $\lambda\to\infty$ and $Z \to\infty$ is studied in some detail in a mean-field approximation. The phase diagram and correlation functions are obtained in the asymptotic regime $\lambda\to\infty$ and $Z \to\infty$, and for infinite dilution of the larger ions (volume fraction $n_p\sim 1/Z$ or less). We find a coexistence between a very dilute 'gas' phase and a crystalline phase in which the macroions form a bcc structure with the lattice constant $\approx 3.6\sigma_+$. Such coexistence was observed experimentally in deionized aqueous solutions of highly charged colloidal particles

European Permanent Grasslands: A Systematic Review of Economic Drivers of Change, Including a Detailed Analysis of the Czech Republic, Spain, Sweden, and UK

\ua9 2024 by the authors. Permanent grasslands (PG) feature in the European rural landscape and represent a major agricultural production resource. They support multiple non-provisioning ecosystem services (ES), including climate regulation, flood control, biodiversity, and pollination. PG are at risk of loss or degradation due to agricultural land use and land management changes. The objective of this systematic review is to identify the main economic influences shaping management and maintenance of PG, and the risks and opportunities for delivery of a range of ES. A total of 51 papers were included. Relevant policy interventions and economic drivers are identified in relation to how they shape the management of EU grasslands over time and across farming systems, countries, or biogeographic zones. A high reliance on public payments from the EU Common Agricultural Policy (CAP), with uneven impact on mitigating PG losses and associated ES provisions, was identified, which needs to be considered in relation to ongoing CAP reform. There is a gap in the literature regarding economic tipping points for change. Future research needs to identify and map ES provisions by PG along with trade-offs and synergies, and link this to policy. There are substantive challenges to maintaining Europe’s PG area and management, which must be addressed through EU-wide instruments

Tradition and Innovation in Classical Sociology: Tenth Anniversary Report of JCS

Perhaps the very idea of ‘classical sociology’ is a contradiction in terms; sociology was originally that social science peculiarly concerned with the study of the processes of modernization and the condition of modernity, that is, with the critical examination of ‘post-traditional’ developments and hence ‘post-classical’ forms of social organization. Its concerns have broadened subsequently, but the focus of sociology remains on the exploration of the nature and development of social structure and social action in the post-traditional world. In the nineteenth century, sociologists invented new concepts and experimented with new methods to study the emergence of unprecedented social phenomena and the rise of a type of society that was variously called ‘modern society’, ‘industrial society’, and ‘capitalist society’. In the twentieth century, there was a further elaboration of key sociological concepts, and it became increasingly popular to proclaim the rise of yet another form of society, described as ‘post-industrial society’, ‘late modern society’, ‘post-modern society’, or ‘network society’. In the current century, the idea of globalization has swept everything before it, leading to the notion that ‘society’ has now been replaced by flows and networks of people, objects, and ideas. With the transition from traditional to modern societies, the integrative power of Gemeinschaft began to compete with the systemic power of Gesellschaft; with the transition from modern to late modern societies, the local horizons of our Lebenswelt appear to be increasingly shaped by the deterritorialized networks of the Weltgesellschaft. If we are ‘post-traditional’, surely we are also ‘post-classical’. It is hardly surprising, therefore, that many contemporary sociologists have some difficulty accepting the very idea of classical sociology