On the stability of network structures with public goods

This paper explores the formation of stable network structures in a model with public goods. The multiplicity of equilibria in the non-cooperative formulation of network formation games brings out further difficulties in analyzing stability of network structures. This contrasts with the cooperative game approach where payoffs for agents are predetermined and thereby the multiplicity of equilibrium issues are sidestepped. We took issue with the multiplicity of equilibrium effort levels exerted on a given network structure, and we suggested different stability definitions for such network structures under multiplicity of equilibria. We demonstrated how these stability notions work for the network structures with four agents where breaking and forming links is costless, and the cost of exerting effort level is linear.

Application of the Laplace-Borel transformation to the representation of analytical solutions of Duffing's equation

Various features of the solutions of Duffing's equation are described using a representation of the solutions in the Laplace-Borel transform domain. An application of this technique is illustrated for the symmetry-breaking bifurcation of a hard spring

Comparing primary prevention with secondary prevention to explain decreasing Coronary Heart Disease death rates in Ireland, 1985-2000.

BACKGROUND: To investigate whether primary prevention might be more favourable than secondary prevention (risk factor reduction in patients with coronary heart disease(CHD)). METHODS: The cell-based IMPACT CHD mortality model was used to integrate data for Ireland describing CHD patient numbers, uptake of specific treatments, trends in major cardiovascular risk factors, and the mortality benefits of these specific risk factor changes in CHD patients and in healthy people without recognised CHD. RESULTS: Between 1985 and 2000, approximately 2,530 fewer deaths were attributable to reductions in the three major risk factors in Ireland. Overall smoking prevalence declined by 14% between 1985 and 2000, resulting in about 685 fewer deaths (minimum estimate 330, maximum estimate 1,285) attributable to smoking cessation: about 275 in healthy people and 410 in known CHD patients. Population total cholesterol concentrations fell by 4.6%, resulting in approximately 1,300 (minimum estimate 1,115, maximum estimate 1,660) fewer deaths attributable to dietary changes(1,185 in healthy people and 115 in CHD patients) plus 305 fewer deaths attributable to statin treatment (45 in people without CHD and 260 in CHD patients). Mean population diastolic blood pressure fell by 7.2%, resulting in approximately 170 (minimum estimate 105, maximum estimate 300) fewer deaths attributable to secular falls in blood pressure (140 in healthy people and 30 in CHD patients), plus approximately 70 fewer deaths attributable to antihypertensive treatments in people without CHD. Of all the deaths attributable to risk factor falls, some 1,715 (68%) occurred in people without recognized CHD and 815(32%) in CHD patients. CONCLUSION: Compared with secondary prevention, primary prevention achieved a two-fold larger reduction in CHD deaths. Future national CHD policies should therefore prioritize nationwide interventions to promote healthy diets and reduce smoking

Nanoplasmonic surfaces enabling strong surface-normal electric field enhancement

Cataloged from PDF version of article.Conventional two-dimensional (2D) plasmonic arrays provide electric field intensity enhancement in the plane, typically with a surface coverage around 50% in the plan-view. Here, we show nanoplasmonic three-dimensional (3D) surfaces with 100% surface coverage enabling strong surface-normal field enhancement. Experimental measurements are found to agree well with the full electromagnetic solution. Along with the surface-normal localization when using the plasmonic 3D-surface, observed maximum field enhancement is 7.2-fold stronger in the 3D-surface than that of the 2D counterpart structure. 3D-plasmonic nonplanar surfaces provide the ability to generate volumetric field enhancement, possibly useful for enhanced plasmonic coupling and interactions. © 2013 Optical Society of America

A new approach for improving coronary plaque component analysis based on intravascular ultrasound images

Virtual histology intravascular ultrasound (VH-IVUS) is a clinically available technique for atherosclerosis plaque characterization. It, however, suffers from a poor longitudinal resolution due to electrocardiogram (ECG)-gated acquisition. This article presents an effective algorithm for IVUS image-based histology to overcome this limitation. After plaque area extraction within an input IVUS image, a textural analysis procedure consisting of feature extraction and classification steps is proposed. The pixels of the extracted plaque area excluding the shadow region were classified into one of the three plaque components of fibro-fatty (FF), calcification (CA) or necrotic core (NC) tissues. The average classification accuracy for pixel and region based validations is 75% and 87% respectively. Sensitivities (specificities) were 79% (85%) for CA, 81% (90%) for FF and 52% (82%) for NC. The kappa (kappa) = 0.61 and p value = 0.02 indicate good agreement of the proposed method with VH images. Finally, the enhancement in the longitudinal resolution was evaluated by reconstructing the IVUS images between the two sequential IVUS-VH images

Effects of dietary fish oil and flax seed on cholesterol and fatty acid composition of egg yolk and blood parameters of laying hens

This study was conducted to determine the effects of the supplementation of different levels of fish oil (FO) and flax seed (FS) in the diets of layers on the content of egg yolk fatty acid, cholesterol, blood parameters, egg production and egg quality criteria. In the experiment, a total of 120 Isa-White laying hens of 34 weeks of age were used. Hens were divided randomly into five groups and fed different diets containing no FO and FS; 1.5% FO; 4.32% FS; 1.5% FO+4.32% FS and 8.64% FS for eight weeks. A significant decrease in yolk cholesterol content (mg/g yolk) was found in the eggs from hens fed the diets containing 1.5 % FO and 8.64% FS as compared with the control. Adding FO and FS to diets significantly increased the total omega-3 fatty acids in eggs at 28 (phase 1) and 56 (phase 2) days of the trial. By contrast, the addition of both FO and FS to diets had no effect on total omega-6 fatty acids in eggs in phase 1. But dietary 1.5% FO, 4.32% FS and 1.5% FO+4.32% FS supplementation decreased significantly the total omega-6 fatty acids compared to the controls in phase 2. The linolenic acid content of eggs was the highest in eggs from hens fed the diet with added FS, while docosahexaenoic acid content was the highest in eggs from hens fed diets with added FO. Dietary supplementation of FO and FS did not significantly affect the concentrations of serum trigliceride and high density lipoprotein. The serum cholesterol level of hens fed diets containing 1.5% FO+4.32% FS and 8.64% FS was lower than the control group. The addition of FO and FS to diets did not cause any negative effect on some egg quality criteria such as egg weight, yolk weight, yolk ratio, albumen weight, albumen ratio, shell weight, shell ratio, shell strength and shell thickness. The egg production of hens fed a diet containing 4.32% FS was significantly higher than the controls. Feed intake and feed conversion were not affected by all treatments. Keywords: Omega-3 fatty acids, Cholesterol eggs, Flax seed, Fish oil South African Journal of Animal Science Vol.33(4) 2003: 266-27

Potential benefits of healthy food and lifestyle policies for reducing coronary heart disease mortality in Turkish adults by 2025: a modelling study

Objective This study uses a modelling approach to compare the potential impact of future risk factor scenarios relating to smoking, physical activity levels, dietary salt, saturated fat intake, mean body mass index (BMI) levels, diabetes prevalence and fruit and vegetable (F&V) consumption on future coronary heart disease (CHD) mortality in Turkey for year 2025. Design A CHD mortality model previously developed and validated in Turkey was extended to predict potential trends in CHD mortality from 2008 to 2025. Setting Using risk factor trends data from recent surveys as a baseline, we modelled alternative evidence-based future risk factor scenarios (modest/ideal scenarios). Probabilistic sensitivity analyses were conducted to account for uncertainties. Subject Projected populations in 2025 (aged 25–84) of 54 million in Turkey. Results Assuming lower mortality, modest policy changes in risk factors would result in ∼25 635 (range: 20 290–31 125) fewer CHD deaths in the year 2025; 35.6% attributed to reductions in salt consumption, 20.9% to falls in diabetes, 14.6% to declines in saturated fat intake and 13.6% to increase in F&V intake. In the ideal scenario, 45 950 (range: 36 780–55 450) CHD deaths could be prevented in 2025. Again, 33.2% of this would be attributed to reductions in salt reduction, 19.8% to increases in F&V intake, 16.7% to reductions in saturated fat intake and 14.0% to the fall in diabetes prevalence. Conclusions Only modest risk factor changes in salt, saturated/unsaturated fats and F&V intake could prevent around 16 000 CHD deaths in the year 2025 in Turkey, even assuming mortality continues to decline. Implementation of population-based, multisectoral interventions to reduce salt and saturated fat consumption and increase F&V consumption should be scaled up in Turkey

Metamaterial based telemetric strain sensing in different materials

Cataloged from PDF version of article.We present telemetric sensing of surface strains on different industrial materials using split-ring-resonator based metamaterials. For wireless strain sensing, we utilize metamaterial array architectures for high sensitivity and low nonlinearity-errors in strain sensing. In this work, telemetric strain measurements in three test materials of cast polyamide, derlin and polyamide are performed by observing operating frequency shift under mechanical deformation and these data are compared with commercially-available wired strain gauges. We demonstrate that hard material (cast polyamide) showed low slope in frequency shift vs. applied load (corresponding to high Young's modulus), while soft material (polyamide) exhibited high slope (low Young's modulus). (C) 2010 Optical Society of America

Design and Realization of a Fully On-Chip High-Q Resonator at 15 GHz on Silicon

Cataloged from PDF version of article.We develop and demonstrate an on-chip resonator working at 15 GHz with a high quality factor (Q-factor) of 93.81 while only requiring a small chip size of 195 mu m x 195 mu m on Si by using our new design methodology. In our design, unlike previous approaches, we avoid the need for any external capacitance for tuning; instead, we utilize the film capacitance as the capacitor of the LC tank circuit and realize a fully on-chip resonator that shows a strong transmission dip of > 30 dB on resonance as required for telemetric-sensing applications. We present the design, theory, methodology, microfabrication, experimental characterization, and theoretical analysis of these resonators. We also demonstrate that the experimental results are in excellent agreement with the theoretical (both analytical and numerical) results. Based on our proof-of-concept demonstration, such high-Q on-chip resonators hold great promise for use in transmissive telemetric sensors