The specificity of frutalin lectin using biomembrane models

Frutalin is a homotetrameric alpha-D-galactose (D-Gal)-binding lectin that activates natural killer cells in vitro and promotes leukocyte migration in vivo. Because lectins are potent lymphocyte stimulators, understanding the interactions that occur between them and cell surfaces can help to the action mechanisms involved in this process. In this paper, we present a detailed investigation of the interactions of frutalin with phospho- and glycolipids using Langmuir monolayers as biomembrane models. The results confirm the specificity of frutalin for D-Gal attached to a biomembrane. Adsorption of frutalin was more efficient for the galactose polar head lipids, in contrast to the one for sulfated galactose, in which a lag time is observed, indicating a rearrangement of the monolayer to incorporate the protein. Regarding ganglioside GM1 monolayers, lower quantities of the protein were adsorbed, probably due to the farther apart position of D-galactose from the interface. Binary mixtures containing galactocerebroside revealed small domains formed at high lipid packing in the presence of frutalin, suggesting that lectin induces the clusterization and the forming of domains in vitro, which may be a form of receptor internalization. This is the first experimental evidence of such lectin effect, and it may be useful to understand the mechanism of action of lectins at the molecular level. (C) 2010 Elsevier B.V. All rights reserved.

The Mobility of Chondroitin Sulfate in Articular and Artificial Cartilage Characterized by (13)C Magic-Angle Spinning NMR Spectroscopy

We have studied the molecular dynamics of one of the major macromolecules in articular cartilage, chondroitin sulfate. Applying (13)C high-resolution magic-angle spinning NMR techniques, the NMR signals of all rigid macromolecules in cartilage can be suppressed, allowing the exclusive detection of the highly mobile chondroitin sulfate. The technique is also used to detect the chondroitin sulfate in artificial tissue-engineered cartilage. The tissue-engineered material that is based on matrix producing chondrocytes cultured in a collagen gel should provide properties as close as possible to those of the natural cartilage. Nuclear relaxation times of the chondroitin sulfate were determined for both tissues. Although T(1) relaxation times are rather similar, the T(2) relaxation in tissue-engineered cartilage is significantly shorter. This suggests that the motions of chondroitin sulfate in data:rat and artificial cartilage different. The nuclear relaxation times of chondroitin sulfate in natural and tissue-engineered cartilage were modeled using a broad distribution function for the motional correlation times. Although the description of the microscopic molecular dynamics of the chondroitin sulfate in natural and artificial cartilage required the identical broad distribution functions for the correlation times of motion, significant differences in the correlation times of motion that are extracted from the model indicate that the artificial tissue does not fully meet the standards of the natural ideal. This could also be confirmed by macroscopic biomechanical elasticity measurements. Nevertheless, these results suggest that NMR is a useful tool for the investigation of the quality of artificially engineered tissue. (C) 2010 Wiley Periodicals, Inc. Biopolymers 93: 520-532, 2010.

Skew-normal linear calibration: a Bayesian perspective

In this paper, we present a Bayesian approach for estimation in the skew-normal calibration model, as well as the conditional posterior distributions which are useful for implementing the Gibbs sampler. Data transformation is thus avoided by using the methodology proposed. Model fitting is implemented by proposing the asymmetric deviance information criterion, ADIC, a modification of the ordinary DIC. We also report an application of the model studied by using a real data set, related to the relationship between the resistance and the elasticity of a sample of concrete beams. Copyright (C) 2008 John Wiley & Sons, Ltd.

The impact of foreign direct investment and openness on Vietnamese economy

This thesis examines the impact of foreign direct investment (FDI) on Vietnamese economy based on Partial Adjustment Model and time series data from 1976 to 2004. FDI is shown to have not only short run but also long run effect on gross domestic product (GDP) of Vietnam. However, elasticity of GDP with respect to FDI is small and it will take many years to fully manifest itself. The impact of trade openness on GDP has also been examined and it is shown to be stronger than that of FDI. The paper offers a number of explanations and discusses briefly suggestions in order to increase the contribution of FDI to Vietnam’s economic development.

The Relationship between Transport Infrastructure and EconomicGrowth: An Empirical Analysis Comparing Developing and DevelopedCountries

Gross domestic product (GDP) is generally considered as the most important index and comprehensive measure of the size of economy. This paper investigates empirically the relationship between transport infrastructure (focus on highways) and GDP growth based on a production function approach. The physical stocks of transport infrastructure were used instead of monetary data to measure public capital together with several other variables (labor and private capital) that were hypothesized to affect economic growth. Then we explore a number of subsequent studies that use panel data covering the period between 1992 and 2004. An investigation was done to compare developed countries and developing countries. Results indicate that physical units are positively and significantly related to economic growth. Furthermore there was an interesting finding that the output elasticity with respect to physical units for developed countries is higher than developing countries.

The program and treatment effect of summer jobs on girls’ post-schooling incomes

Public programs (of disputed effect) offering summer jobs or work while in high school to smooth the transition from school to work is commonplace. In this paper, 1447 girls in their first grade of high school between 1997-2003 and randomly allotted summer jobs via a program in Falun (Sweden) are followed 5-12 years after graduation. The program led to a substantially larger accumulation of income while in high school. The causal effect of the high school income on post-schooling incomes was substantial and statistically significant. The implied elasticity of 0.4 is however potentially inflated dueto heterogeneous effects.

Investigation of effective material properties in composites with internal defect or reinforcement particles

This paper is concerned with the investigation of the effective material properties of internally defective or particle-reinforced composites. An analysis was carried out with a novel method using the two-dimensional special finite element method mixing the concept of equivalent homogeneous materials. A formulation has been developed for a series of special finite elements containing an internal defect or reinforcement in order to assure the high accuracy especially in the vicinity of defects or reinforcements. The adoption of the special finite element can greatly simplify numerical modeling of particle-composites. The numerical result provides the effective material properties of particle-reinforced composite and explains that the size of particles has great influence on the material properties. Numerical examples also demonstrate the validity and versatility of the proposed method by comparing with existing results from literatures.

Pricing segmentation and MBA course choice

The consensus from studies of the price-demand relationship for higher education is that this relationship is negative but small. This paper investigates the circumstances in which demand for an MBA is positive to price increases. A survey of currently enrolled MBA students, and prospective MBA students, found that most students displayed the expected price elasticity in a conjoint analysis of hypothetical MBA course ratings. However, 12 per cent of respondents exhibited “reversal” behaviour regarding price. Profiling these respondents using discriminant analysis suggested that “reversals” seemed prepared to pay more for a course at a high prestige university, if they could study off-campus using print-based materials.

Dymanic mechanical analysis of polyvinylalcohol/silica nanocomposite

Polyvinylalcohol/Silica (PVA/SiO₂) nanocomposites with different SiO₂ contents are synthesized by employing a novel self-assembly monolayer (SAM) technique. The influence of the silica on dynamic mechanical properties of the nanocomposites is investigated by conducting dynamic mechanical analysis (DMA) and quasi-thermal mechanical analysis (Q-TMA). It is found that the storage modulus (E′), loss factor (tga), glass transition temperature (T_g), and activation energy (E_a) of prepared nanocomposites all show a strong dependence on the SiO₂ content. The Q-TMA results indicate that under a constant force, the elasticity of nanocomposites decreases with SiO₂ content, and the softening temperature moves to a higher temperature when more SiO₂ is added.

A panel cointegration analysis of the demand for oil in the Middle East

This article applies recently developed panel unit root and panel cointegration techniques to estimate the long-run income and price elasticities for oil in the Middle East. The results for the panel indicate that demand for oil is highly price inelastic and slightly income elastic in the Middle East. There is considerable variation in the results for the income variable across countries, with the coefficient on the income variable statistically insignificant for several countries. The coefficient on the price variable is statistically significant in all cases with the expected sign and the price elasticity is uniformly low. While the results for the income variable differ across countries, the results for the panel as a whole suggest that the demand for oil in the Middle East is being driven largely by strong economic growth, while consumers are largely insensitive to price changes.

Protection versus promotion: an empirical investigation

Using Turkish industry-level data from 1983 to 1990, we find that politically organized industries receive both higher protection and promotion than unorganized ones. Tariff rates are decreasing (increasing) in the import-penetration ratio and the absolute value of the import-demandelasticity for organized (unorganized) industries. Subsidy rates are decreasing (increasing) in the output-supply elasticity for organized (unorganized) industries. The results are consistent with the predictions of the Grossman–Helpman model and its extension in this paper. The mix of protection and promotion is inversely related to the ratio of their respective marginal deadweight cost measures.

Small diameter Polyurethane vascular graft reinforced by elastic weft-knitted tubular fabric of polyester / spandex

Small diameter vascular grafts were fabricated from pure Polyurethane (PU) as well as PU reinforced with a tubular weft-knitted fabric. The tensile properties of the reinforced composite vascular grafts were compared with that of the tubular fabric itself and the pure PU vascular grafts. The elasticity and strength of the reinforced vascular grafts were improved compared with the tubular fabric. Strength of the reinforced vascular grafts was 5–10 times of the strength of the pure PU vascular grafts. Expanding the tubular fabric to increase the inner diameter of the reinforced vascular graft reduced the graft’s strength and initial modulus, but the difference was reduced as the PU content was increased. For grafts of the same inner diameter, increasing the PU content increased the thickness and strength of the graft wall, which led to a general increase in the strength and initial modulus of the composite vascular grafts.

A test of the Wagner's hypothesis for the Fiji Islands

In this article we examine Wagner's law for Fiji for the period 1970 to 2002. Using the Johansen (1988) test for cointegration, we find one cointegration relationship between national output and government expenditure. Using five different long run estimators, we find robust results on the impact of national income on government expenditure. The elasticity ranges from 1.36 to 1.44, implying that a 1% increase in income leads to a 1.36-1.44% increase in government expenditure. Moreover, we find that in the long run national income Granger causes government expenditure. While these results are consistent with Wagner's law, we warn policy makers that because Fiji's total debt stands at around 69% of GDP, in future the bulk of expenditure will go towards debt financing at the expense of productive sectors.

Modelling income group differences in the health and economic impacts of targeted food taxes and subsidies

Objective : To examine the effects, by income group, of targeted food taxes and subsidies on nutrition, health and expenditure in the UK.

Methods : A model based on consumption data and demand elasticity was constructed to predict the effects of four food taxation-subsidy regimens. Resulting changes in demand, expenditure, nutrition, cardiovascular disease (CVD) and cancer mortality were estimated.

Data : Expenditure data were taken from the Expenditure and Food Survey; estimates of price elasticities of demand for food were taken from a report based on the National Food Survey 1988–2000. Estimates of effect on CVD and cancer mortality of changing fat, salt, fruit and vegetable intake were taken from previous meta-analyses.

Results : (i) Taxing principal sources of dietary saturated fat is unlikely to reduce cardiovascular disease (CVD) or cancer mortality. (ii) Taxing ‘less healthy’ foods (defined by the WXYfm nutrient profiling model) could increase CVD and cancer deaths by 35–1300 yearly. (iii) Taxing ‘less healthy’ foods and subsidising fruits and vegetables by 17.5% could avert up to 2900 CVD and cancer deaths yearly. (iv) Taxing ‘less healthy’ foods and using all tax revenue to subsidize fruits and vegetables could avert up to 6400 CVD and cancer deaths yearly. Few obesity-related CVD deaths are averted by any of the regimens. All four regimens would be economically regressive and positive health effects will not necessarily be greater in lower-income groups where the need for dietary improvement is higher.

Conclusions : A targeted food tax combined with the appropriate subsidy on fruits and vegetables could reduce deaths from CVD and cancer.

Relative responsiveness of bargaining solutions to changes in status-quo payoffs

It is a well-known fact that several prominent bargaining solutions are responsive to changes in status-quo (i.e., disagreement or fallback) payoffs. When an agent’s status-quo payoff increases, his solution payoff either stays the same or increases. A fully general result for these solutions’ status-quo point ranking is impossible to establish. In this paper, using an important class of bargaining problems, a ranking of the relative status-quo point responsiveness of prominent bargaining solutions is obtained. Using the Constant Elasticity of Substitution class of bargaining problems, regardless of the concavity of the Pareto frontier and the level of increase in one’s status-quo payoff, we find the equal gains solution is the most responsive with respect to changes in status-quo payoffs, followed by the Nash solution. The equal sacrifice solutions is the least responsive, followed by the Kalai/Smorodinsky solution.