Using Positive Youth Development Constructs to Design a Money Management Curriculum for Junior Secondary School Students in Hong Kong

This paper aims to discuss the relationships between the selected positive youth development constructs and the enhancement of Hong Kong junior secondary school students' money management skills, values, and attitudes. Various issues of money management of adolescents are reviewed. These issues include the need for money management programs for adolescents, the content and coverage of an appropriate money management program, and its relationships with the selected positive youth development constructs. The curriculum units for secondary 3 students are taken as examples to illustrate the design of the program. It is believed that promoting cognitive competence, self-efficacy, and spirituality could be an effective way to enhance students' money management skills, values, and attitudes, thus preparing them better for facing the finance-related issues in life

Diffusive Evolution of Stable and Metastable Phases II: Theory of Non-Equilibrium Behaviour in Colloid-Polymer Mixtures

By analytically solving some simple models of phase-ordering kinetics, we suggest a mechanism for the onset of non-equilibrium behaviour in colloid-polymer mixtures. These mixtures can function as models of atomic systems; their physics therefore impinges on many areas of thermodynamics and phase-ordering. An exact solution is found for the motion of a single, planar interface separating a growing phase of uniform high density from a supersaturated low density phase, whose diffusive depletion drives the interfacial motion. In addition, an approximate solution is found for the one-dimensional evolution of two interfaces, separated by a slab of a metastable phase at intermediate density. The theory predicts a critical supersaturation of the low-density phase, above which the two interfaces become unbound and the metastable phase grows ad infinitum. The growth of the stable phase is suppressed in this regime.Comment: 27 pages, Latex, eps

Role of Multipoles in Counterion-Mediated Interactions between Charged Surfaces: Strong and Weak Coupling

We present general arguments for the importance, or lack thereof, of the structure in the charge distribution of counterions for counterion-mediated interactions between bounding symmetrically charged surfaces. We show that on the mean field or weak coupling level, the charge quadrupole contributes the lowest order modification to the contact value theorem and thus to the intersurface electrostatic interactions. The image effects are non-existent on the mean-field level even with multipoles. On the strong coupling level the quadrupoles and higher order multipoles contribute additional terms to the interaction free energy only in the presence of dielectric inhomogeneities. Without them, the monopole is the only multipole that contributes to the strong coupling electrostatics. We explore the consequences of these statements in all their generality.Comment: 12 pages, 3 figure

Leaf segmentation and tracking using probabilistic parametric active contours

Active contours or snakes are widely used for segmentation and tracking. These techniques require the minimization of an energy function, which is generally a linear combination of a data fit term and a regularization term. This energy function can be adjusted to exploit the intrinsic object and image features. This can be done by changing the weighting parameters of the data fit and regularization term. There is, however, no rule to set these parameters optimally for a given application. This results in trial and error parameter estimation. In this paper, we propose a new active contour framework defined using probability theory. With this new technique there is no need for ad hoc parameter setting, since it uses probability distributions, which can be learned from a given training dataset

The Role of Solid Friction in the Sedimentation of Strongly Attractive Colloidal Gels

We study experimentally and theoretically the sedimentation of gels made of strongly aggregated colloidal particles, focussing on the long time behavior, when mechanical equilibrium is asymptotically reached. The asymptotic gel height is found to vary linearly with the initial height, a finding in stark contrast with a recent study on similar gels [Manley \textit{et al.} 2005 \textit{Phys. Rev. Lett.} \textbf{94} 218302]. We show that the asymptotic compaction results from the balance between gravity pull, network elasticity, and solid friction between the gel and the container walls. Based on these ingredients, we propose a simple model to account for the dependence of the height loss on the initial height and volume fraction. As a result of our analysis, we show that the static friction coefficient between the gel and the container walls strongly depends on volume fraction: the higher the volume fraction, the weaker the solid friction. This nonintuitive behavior is explained using simple scaling arguments.Comment: 13 pages, 5 figures. Submitted to JSTA

Phase behaviour of additive binary mixtures in the limit of infinite asymmetry

We provide an exact mapping between the density functional of a binary mixture and that of the effective one-component fluid in the limit of infinite asymmetry. The fluid of parallel hard cubes is thus mapped onto that of parallel adhesive hard cubes. Its phase behaviour reveals that demixing of a very asymmetric mixture can only occur between a solvent-rich fluid and a permeated large particle solid or between two large particle solids with different packing fractions. Comparing with hard spheres mixtures we conclude that the phase behaviour of very asymmetric hard-particle mixtures can be determined from that of the large component interacting via an adhesive-like potential.Comment: Full rewriting of the paper (also new title). 4 pages, LaTeX, uses revtex, multicol, epsfig, and amstex style files, to appear in Phys. Rev. E (Rapid Comm.

Strong Coupling Electrostatics in the Presence of Dielectric Inhomogeneities

We study the strong-coupling (SC) interaction between two like-charged membranes of finite thickness embedded in a medium of higher dielectric constant. A generalized SC theory is applied along with extensive Monte-Carlo simulations to study the image charge effects induced by multiple dielectric discontinuities in this system. These effects lead to strong counterion crowding in the central region of the inter-surface space upon increasing the solvent/membrane dielectric mismatch and change the membrane interactions from attractive to repulsive at small separations. These features agree quantitatively with the SC theory at elevated couplings or dielectric mismatch where the correlation hole around counterions is larger than the thickness of the central counterion layer.Comment: 4 pages, 3 figure

Theory and simulation of short-range models of globular protein solutions

We report theoretical and simulation studies of phase coexistence in model globular protein solutions, based on short-range, central, pair potential representations of the interaction among macro-particles. After reviewing our previous investigations of hard-core Yukawa and generalised Lennard-Jones potentials, we report more recent results obtained within a DLVO-like description of lysozyme solutions in water and added salt. We show that a one-parameter fit of this model based on Static Light Scattering and Self-Interaction Chromatography data in the dilute protein regime, yields demixing and crystallization curves in good agreement with experimental protein-rich/protein-poor and solubility envelopes. The dependence of cloud and solubility points temperature of the model on the ionic strength is also investigated. Our findings highlight the minimal assumptions on the properties of the microscopic interaction sufficient for a satisfactory reproduction of the phase diagram topology of globular protein solutions.Comment: 17 pages, 8 figures, Proc. of Conference "Structural Arrest Transitions in Colloidal Systems with Short-Range Attractions", Messina (ITALY) 17-20 December 200