Mathematical models for vulnerable plaques

A plaque is an accumulation and swelling in the artery walls and typically consists of cells, cell debris, lipids, calcium deposits and fibrous connective tissue. A person is likely to have many plaques inside his/her body even if they are healthy. However plaques may become "vulnerable", "high-risk" or "thrombosis-prone" if the person engages in a high-fat diet and does not exercise regularly. In this study group, we proposed two mathematical models to describe plaque growth and rupture. The first model is a mechanical one that approximately treats the plaque as an inflating elastic balloon. In this model, the pressure inside the core increases and then decreases suggesting that plaque stabilization and prevention of rupture is possible. The second model is a biochemical one that focuses on the role of MMPs in degrading the fibrous plaque cap. The cap stress, MMP concentration, plaque volume and cap thickness are coupled together in a system of phenomenological equations. The equations always predict an eventual rupture since the volume, stresses and MMP concentrations generally grow without bound. The main weakness of the model is that many of the important parameters that control the behavior of the plaque are unknown. The two simple models suggested by this group could serve as a springboard for more realistic theoretical studies. But most importantly, we hope they will motivate more experimental work to quantify some of the important mechanical and biochemical properties of vulnerable plaques

Reflecting random walk in fractal domains

In this paper, we show that reflecting Brownian motion in any bounded domain D can be approximated, as $k\to\infty$, by simple random walks on "maximal connected" subsets of $(2^{-k}\mathbb{Z}^d)\cap D$ whose filled-in interiors are inside of D.Comment: Published in at http://dx.doi.org/10.1214/12-AOP745 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

AN IMPACT ASSESSMENT OF THE FUTURE CAP REFORM ON THE ITALIAN TOMATO SECTOR

The Health Check (HC) document traces the path for a new revision of the CAP. The communication content can be summarised in the following points: decoupling at regional and not at historical level, a more intensive modulation mechanism differentiated according to the total volume of subsidy received by the farm and a new implementation of the art. 69. The aim of this paper is to assess the effect of the HC on the farms producing fruits and vegetables in Italy, with a particular emphasis on the processed tomato production. The model based on the PMP approach simulates the regionalisation mechanism and the new modulation per brackets. The analysis carried out on a FADN sample of farms located in Emilia-Romagna region highlights as the HC new measures affect the farm economic performances but not the input allocation choice. The flat rate doesn’t produce perturbation in the relative convenience of the crops maintaining unchanged the degree of substitution among activities. Only when the CAP mechanism moves from a coupling scenario to a total decoupling one and in the case of a variation in price levels the modifications inside the production plan are evident.Future CAP reforms, Tomato sector, CAP assessment, Agricultural and Food Policy, Political Economy, Q10, Q18,

Quark-nova explosion inside a collapsar: application to Gamma Ray Bursts

If a quark-nova occurs inside a collapsar, the interaction between the quark-nova ejecta (relativistic iron-rich chunks) and the collapsar envelope, leads to features indicative of those observed in Gamma Ray Bursts. The quark-nova ejecta collides with the stellar envelope creating an outward moving cap (Gamma ~ 1-10) above the polar funnel. Prompt gamma-ray burst emission from internal shocks in relativistic jets (following accretion onto the quark star) become visible after the cap becomes optically thin. Model features include: (i) precursor activity (optical, X-ray, gamma-ray), (ii) prompt gamma-ray emission, and (iii) afterglow emission. We discuss SN-less long duration GRBs, short hard GRBs (including association and non-association with star forming regions), dark GRBs, the energetic X-ray flares detected in Swift GRBs, and the near-simultaneous optical and gamma-ray prompt emission observed in GRBs in the context of our model.Comment: 10 journal pages and 5 figures (updated references and extended discussions; accepted for publication in Advances in Astronomy

Effect of temperature, relative humidity and moisture content on germination percentage of wheat stored in different storage structures

The paper presents information regarding the pattern of changes in the environmental conditions (i.e. temperature, relative humidity and moisture content) on the stored wheat in Galvanized Iron Corrugated (GIC) silo, Godown storage and CAP storage.  The grain moisture content in the silo increased from 11.20% to 17.08% wet basis (w.b.), in bag storage increased from 11.20% to 17.25%, and in CAP storage increased from 11.20% to 17.19% wet basis (w.b.) during the storage period from April 06 to November 06.  The moisture content of the wheat grain then slightly decreased during the storage period from November 06 to April 07.  The temperature of the grain inside silo was 29.30℃ while at the end of the storage period, the temperature was 42.90℃.  The initial grain temperature inside Godown storage was 29.30℃ and at the end of the storage period, it was 32.31℃.  The initial grain temperature inside CAP storage was 29.10℃ and it increased to 39.94℃ at the end of the storage period.  The relative humidity in the silo was 16.1% lower than the ambient relative humidity.  The germination percentage of grain inside the silo was decreased from 86.70% to 78.60%, in Godown storage it decreased from 86.70% to 53.30%, and in CAP storage it decreased from 86.70% to 46.60% during the storage period from April to September. Keywords: temperature, moisture content, relative humidity, germination percentage, wheat, GIC, silo, Godown, CA