What happened to risk dispersion?

The turbulence in credit and funding markets in the second half of 2007 is disturbing evidence that risk dispersion in financial markets has been less effective than expected. Investors appear to have acquired risks that they did not understand. Much more worrisome, however, is the evidence that major financial firms did not succeed in shedding risks so much as in transferring them among their own business lines, resulting in an unintended concentration of risks on their own balance sheets. In order to restore confidence in the near term, and to put credit creation on a more sustainable path in the future, supervisory authorities, central banks and governments will first need to understand why the much-vaunted dispersion of risk fell so far short of expectations. The “reluctance to lend” which underlies these strains in money markets was widely attributed to concerns about the financial condition of borrowers, as a consequence of uncertainty about the value of assets on the borrowers’ balance sheets, and also to insuffi cient attention to liquidity management by financial firms. But the focus on uncertainty about borrowers ignores the awkward fact that the major financial intermediaries are both lenders and borrowers themselves and their reluctance to lend significantly reflects a defensive reaction to their own uncertainties about their own balance sheets. Better stress testing for liquidity as well as solvency would certainly be beneficial. Yet a major cause of the strains in credit and funding markets has been the apparent inability of many firms to anticipate the interaction of their various on- and off-balance sheet exposures and, particularly, to understand the velocity of their off-balance sheet activities and how these affected their overall exposures. In considering potential remedies to the credit market’s turbulence and to the apparent failure of risk dispersion, the authorities should first reflect on their own role in the trend of pushing risks off of bank balance sheets.

Peer education and empowerment: perspectives from young women working as peer educators with Home-Start

This paper focuses on peer education and specifically on young women peer educators working within the charity Home-Start in the north of England. This work is undertaken in a social context where educational achievement is increasingly measured by certification and occupational hierarchies have been ‘professionalised’ whilst notions of professionalism have been drained of meaning in ways which can be potentially democratising. State educational imperatives in the UK have focussed on concepts such as academic excellence and the promotion of vocational opportunities (for those from ‘hard working families’). Within this paper the peer educator is positioned as generally similar to the individuals and groups with which they work in that they are likely to share characteristics including age, gender, ethnicity, social class, and educational attainment. The peer educators who participated in the study support each other in circumstances that lead to mutual benefits which are largely outside the educational mainstream. The paper considers motivations for involvement as a peer educator, peer educators’ perspectives on the benefits/value of this work, the impact on confidence and aspiration, as well as their experiences of engagement and encounters with professionals. The paper, which focusses on empowerment, is informed by thinking on the importance of recognition and suggests that peer education holds potential for propagating forms of pedagogy which are relatively free of the authoritative relationships typically associated with ‘teaching’

Cluster approach study of intersite electron correlations in pyrochlore and checkerboard lattices

To treat effects of electron correlations in geometrically frustrated pyrochlore and checkerboard lattices, an extended single-orbital Hubbard model with nearest neighbor hopping $\sim t$ and Coulomb repulsion $\sim V$ is applied. Infinite on-site repulsion, $U\to\infty$, is assumed, thus double occupancies of sites are forbidden completely in the present study. A variational Gutzwiller type approach is extended to examine correlations due to short-range $V-$interaction and a cluster approximation is developed to evaluate a variational ground state energy of the system. Obtained analytically in a special case of quarter band filling appropriate to LiV$_2$O$_4$, the resulting simple expression describes the ground state energy in the regime of intermediate and strong coupling $V$. Like in the Brinkman-Rice theory based on the standard Gutzwiller approach to the Hubbard model, the mean value of the kinetic energy is shown to be reduced strongly as the coupling $V$ approaches a critical value $V_{c}$. This finding may contribute to explaining the observed heavy fermion behavior in LiV$_2$O$_4$

Integration of Technology in Math and Science Education – A Model for Teaching Elementary and Middle School Pre-Service Teachers

This paper describes the development and implementation of a course, Integration of Technology in Math and Science Education, to introduce elementary and middle school pre-service teachers to real technology skills that they can use in their future classrooms. Activities allowed the students to learn technology skills while using the Internet to enrich their content skills and share information with their fellow students. The course was designed to allow students to master a variety of technology skills, and see how these skills can be used appropriately in their future classrooms, while also increasing their comfort level to use the technology and reduce their resistance and anxiety to use it later in their real-time classrooms. During the class hands-on activities, the students became fluent at using the Internet for enrichment and communication, and at developing strategies for using their new skills to present SOL-relevant lesson plans. Students enter this course with very little in the way of educational technology skills, but leave with a teaching toolbox filled with new skills

Observation of fine one-dimensionally disordered layers in silicon carbide

The improved resolution of synchrotron edge-topography is enabling thinner (less than 100 microns), silicon carbide crystals to be studied, and is providing a more detailed and wider database on polytype depth profiles. Fine long-period and one-dimensionally-disordered layers, 5-25 microns thick, can now be confidently resolved and are found to be very common features, often in association with high-defect density bands. These features are illustrated in this paper using three examples. A new long period polytype LPP (152H/456R) has been discovered and reported here for the first time

An Unsplit, Cell-Centered Godunov Method for Ideal MHD

We present a second-order Godunov algorithm for multidimensional, ideal MHD. Our algorithm is based on the unsplit formulation of Colella (J. Comput. Phys. vol. 87, 1990), with all of the primary dependent variables centered at the same location. To properly represent the divergence-free condition of the magnetic fields, we apply a discrete projection to the intermediate values of the field at cell faces, and apply a filter to the primary dependent variables at the end of each time step. We test the method against a suite of linear and nonlinear tests to ascertain accuracy and stability of the scheme under a variety of conditions. The test suite includes rotated planar linear waves, MHD shock tube problems, low-beta flux tubes, and a magnetized rotor problem. For all of these cases, we observe that the algorithm is second-order accurate for smooth solutions, converges to the correct weak solution for problems involving shocks, and exhibits no evidence of instability or loss of accuracy due to the possible presence of non-solenoidal fields.Comment: 37 Pages, 9 Figures, submitted to Journal of Computational Physic

Quantum critical phenomena of long-range interacting bosons in a time-dependent random potential

We study the superfluid-insulator transition of a particle-hole symmetric system of long-range interacting bosons in a time-dependent random potential in two dimensions, using the momentum-shell renormalization-group method. We find a new stable fixed point with non-zero values of the parameters representing the short- and long-range interactions and disorder when the interaction is asymptotically logarithmic. This is contrasted to the non-random case with a logarithmic interaction, where the transition is argued to be first-order, and to the $1/r$ Coulomb interaction case, where either a first-order transition or an XY-like transition is possible depending on the parameters. We propose that our model may be relevant in studying the vortex liquid-vortex glass transition of interacting vortex lines in point-disordered type-II superconductors.Comment: 10 pages, 3 figure

Partial breakdown of quantum thermalization in a Hubbard-like model

We study the possible breakdown of quantum thermalization in a model of itinerant electrons on a one-dimensional chain without disorder, with both spin and charge degrees of freedom. The eigenstates of this model exhibit peculiar properties in the entanglement entropy, the apparent scaling of which is modified from a "volume law" to an "area law" after performing a partial, site-wise measurement on the system. These properties and others suggest that this model realizes a new, non-thermal phase of matter, known as a quantum disentangled liquid (QDL). The putative existence of this phase has striking implications for the foundations of quantum statistical mechanics.Comment: As accepted to PR

Actinomycosis-Like Lesions Caused By Corynebacterium

On February 11, 1942, a veterinarian was called to treat an eight month old purebred Hereford steer. The caretaker gave a history of a slowly developing enlargement posterior to the mandible. The condition was diagnosed as parotitis and the animal was treated with an organic iodide per orum