Geoffrey Meen and Christine Whitehead,Understanding Affordability. The Economics of Housing Markets

Journal of Housing and the Built Environment -     

Plasma leptin is not associated with insulin resistance and proinsulin in non-diabetic South Asian Indians

In an earlier study, we observed only a weak association between plasma insulin (non-specific assay) and leptin in South Asian Indians. This was in contrast to the observations in many other ethnic groups. With the availability of measurements of specific insulin (SI) and proinsulin (PI) in the same study group, we have reanalysed the data to look for possible correlation of leptin with proinsulin and with insulin resistance calculated from the fasting values of specific insulin and glucose using the HOMA model. Subjects with normoglycaemia (n = 117) and impaired glucose tolerance (n = 27, WHO criteria) were included in the analysis. Leptin values were higher in women. Multiple linear regression analysis showed that the variations in leptin concentrations in men were associated with BMI, WHR, and 2 h SI values (R2 = 56.2%) while fasting SI and proinsulin concentrations had no significant association. In women BMI and age showed a significant association with serum leptin values (R2 = 40.1%). Univariate and multivariate analyses using insulin resistance as the dependent variable showed that it had no association with leptin in both genders. Leptin had no correlation with proinsulin also. This study confirmed that in Asian Indians the association between plasma leptin and insulin concentrations is weak and that leptin has no influence on insulin resistance. Proinsulin and leptin are also not correlated in this population. Insulin resistance shows correlation with the beta-cell function both in men and women.     

Subsidization as motor to residential mortgage securitization in the US

Residential mortgage securitization on the secondary mortgage market in the United States has grown enormously since 1970. This contribution describes the growth, especially the growth of the large special circuit housing finance system within the secondary mortgage market. Fannie Mae and Freddie Mac are at the heart of it. Different housing finance systems are introduced first in order to position the system of securitization. The technicalities of securitization are then briefly covered, before the focus shifts to the development of residential mortgage securitization in the United States. The reasons for expansion of the secondary mortgage market are traced, and especially of Fannie Mae and Freddie Mac and the benefits they offer to homeowners and the buyers of securities. The success of securitization by Fannie Mae and Freddie Mac does not seem to be based on a miracle of competition in the housing finance market, but largely on regulation and subsidization of these organizations. Nowadays, the question has become whether the undesired effects of this large part of the housing finance market outbalance the desired effects.

Computer-assisted evaluation of undergraduate courses in frequency-domain techniques for system control

An innovative computer-assisted teaching technique is proposed as an effective way to help in the assessment of undergraduate courses in classical control theory. Using an iterative Matlab/Simulink based algorithm, the task of identifying an unknown linear system from its frequency response is given to the students. At each step, the student improves his/her approximation to minimize the frequency response of the mismatch and decides whether the estimate is sufficient. The proposed self-evaluation task gives the students a means to analyze Bode diagrams and system identification techniques, nontrivial issues in introductory courses in control systems theory.     

Gradient-based learning applied to document recognition

Multilayer neural networks trained with the back-propagation algorithm constitute the best example of a successful gradient based learning technique. Given an appropriate network architecture, gradient-based learning algorithms can be used to synthesize a complex decision surface that can classify high-dimensional patterns, such as handwritten characters, with minimal preprocessing. This paper reviews various methods applied to handwritten character recognition and compares them on a standard handwritten digit recognition task. Convolutional neural networks, which are specifically designed to deal with the variability of 2D shapes, are shown to outperform all other techniques. Real-life document recognition systems are composed of multiple modules including field extraction, segmentation recognition, and language modeling. A new learning paradigm, called graph transformer networks (GTN), allows such multimodule systems to be trained globally using gradient-based methods so as to minimize an overall performance measure. Two systems for online handwriting recognition are described. Experiments demonstrate the advantage of global training, and the flexibility of graph transformer networks. A graph transformer network for reading a bank cheque is also described. It uses convolutional neural network character recognizers combined with global training techniques to provide record accuracy on business and personal cheques. It is deployed commercially and reads several million cheques per day     

Costs and fiscal subsidies in owner occupation: Method and outcomes

This article formulates an answer to the followingquestion: Which concept is most suitable to compare the levels ofhousing costs and fiscal subsidies among owner-occupiers and how canthis concept be applied? First, the concepts of housing expenditure anduser costs of capital are evaluated. The preference for the latter conceptis then explained and the notion of subsidy is defined within the usercost framework. Finally, the use of the preferred concept is illustratedwith hypothetical calculations for sample households in Denmark,England, the Netherlands and Germany.     

Genetic relationship between measures of HDL phenotypes and insulin concentrations

Stimulation of T cells via the T cell receptor (TCR) leads to an increase intracellular in free Ca2+ levels ([Ca2+]i) and the activation of the MAP kinase signaling pathway. This study analyzes for the first time Ca2+ fluxes in naive cytotoxic T cells stimulated with full agonists, partial agonists, or antagonists. Four different types of Ca2+ responses could be observed. Full agonists triggered a strong and sustained increase in [Ca2+]i. In contrast, partial T cell agonists induced either a strong but transient Ca2+ flux or very low to no increases in [Ca2+]i, while T cell antagonists failed to induce any measurable Ca2+ flux. The ability of peptides to induce elevated [Ca2+]i perfectly paralleled their ability to trigger TCR internalization and T cell activation. Thus, stimulation of naive cytotoxic T cells with a panel of defined altered peptide ligands reveals a consistent picture, where Ca2+ fluxes predict agonist, partial agonist and antagonist properties of peptides.     

Bridging the Gap between Housing Stress and Financial Stress: The Case of Australia

In recent decades, housing affordability has been increasingly linked to household financial outcomes where high housing costs relative to income are perceived to negatively affect financial well-being. However, the traditional measure of housing affordability in Australia is housing stress, which is subject to widespread criticism as an inadequate representation of overall financial stress. This methodological paper first determines the extent to which housing stress correlates with experiences of financial stress and, second, demonstrates ways in which the measure can be modified to deliver a more reliable indication of how housing costs affect financial well-being. The study contributes to the international literature by showing how the use of longitudinal data can improve the measure of housing stress providing a more accurate assessment of the relationship between housing costs and financial well-being.     

Bisphenol A (BPA) in U.S. food

Bisphenol A (BPA) is a chemical used for lining metal cans and in polycarbonate plastics, such as baby bottles. In rodents, BPA is associated with early sexual maturation, altered behavior, and effects on prostate and mammary glands. In humans, BPA is associated with cardiovascular disease, diabetes, and male sexual dysfunction in exposed workers. Food is a major exposure source. We know of no studies reporting BPA in U.S. fresh food, canned food, and food in plastic packaging in peer reviewed journals. We measured BPA levels in 105 fresh and canned foods, foods sold in plastic packaging, and in cat and dog foods in cans and plastic packaging. We detected BPA in 63 of 105 samples, including fresh turkey, canned green beans, and canned infant formula. Ninety-three of these samples were triplicates which had similar detected levels. Detected levels ranged from 0.23 to 65.0 ng/g ww and were not associated with type of food or packaging but did vary with pH. BPA levels were higher for foods of pH 5 compared to more acidic and alkaline foods. Detected levels were comparable to those found by others. Further research is indicated to determine BPA levels in U.S. food in larger, representative sampling.