Nonintersecting random walks in the neighborhood of a symmetric tacnode

Consider a continuous time random walk in $\mathbb{Z}$ with independent and exponentially distributed jumps $\pm1$. The model in this paper consists in an infinite number of such random walks starting from the complement of $\{-m,-m+1,\ldots,m-1,m\}$ at time -t, returning to the same starting positions at time t, and conditioned not to intersect. This yields a determinantal process, whose gap probabilities are given by the Fredholm determinant of a kernel. Thus this model consists of two groups of random walks, which are contained within two ellipses which, with the choice $m\simeq2t$ to leading order, just touch: so we have a tacnode. We determine the new limit extended kernel under the scaling $m=\lfloor2t+\sigma t^{1/3}\rfloor$, where parameter $\sigma$ controls the strength of interaction between the two groups of random walkers.Comment: Published in at http://dx.doi.org/10.1214/11-AOP726 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Cacao agroforestry systems do not increase pest and disease incidence compared with monocultures under good cultural management practices

Pests and diseases threaten cacao production worldwide. Agroforestry systems are traditionally seen by farmers as one of the causes of increased pest and disease incidence, in contrast with full-sun monocultures. Cultural management practices - e.g. regular tree pruning, frequent pod harvest, regular removal of infested pods, weed management - have been reported to be crucial for pest and disease management. We performed two experiments for the purpose of assessing the effect of (i) different cacao production systems, and (ii) the frequency of harvest and removal of infested pods on the incidence of pests and diseases and on the cacao yield. The first experiment was performed in a long-term system comparison trial in Bolivia, where data on pest and disease incidence were recorded for three years in five production systems: two monocultures and two agroforestry system under organic and conventional farming, and one successional agroforestry system, i.e. a high tree density multi-strata system. Pest and disease management did not differ between systems and relied on cultural management practices. Overall, the incidence of pests and diseases did not differ between production systems, which indicated they were not the driver of yield differences between them. Across production systems, only 14% of the pods were affected by pests and diseases; 70% of these were affected by frosty pod rot. More than 80% of the pods infected by frosty pod rot were removed before the sporulation phase. In the second experiment, the effects of the frequency of harvest and removal of infected pods - every 15 days versus every 25 days - on pest and disease incidence and yield were tested in four farmers’ fields. Fortnightly harvest and diseased pod removal significantly decreased disease incidence and increased cacao yield, by 25% and 46% respectively. Our results show that cacao agroforestry systems do not increase pest and disease incidence compared with monocultures when good cultural management practices are implemented, which, in turn, can increase the productivity of the cacao plantations

The cost of import prohibition for political reason: CGE analysis of the Russian ban on agri-food products

In August 2014, Russia imposed a one year import ban on most agri-food products from countries enforcing Ukraine-related sanctions against Russia. A computable general equilibrium (CGE) model is used to simulate effects of this retaliatory policy shift across the European Union (EU), Russia and a selection of key trade partners. Sensitivity analysis of factor mobility is performed to better capture short term and long term implications of this import prohibition, while latest trade data are carefully prepared and exploited. In the short term, due to high factor immobility, production has very little leeway to adjust, provoking notable variations in prices which absorb most of the import ban shock. At EU level, price and production decrease by about 1.9% and 0.3% respectively, while in the longer term (if the ban is maintained beyond one year) these figures amount 1.4% and 1.2% respectively. Interestingly, results indicate that Russia is the region with the highest welfare loss (about 3.4 billion euros) while the EU can recover around 25% of the lost trade volume with Russia through expansion of exports to other markets

Matrice de comptabilité sociale désagrégée de l'économie sénégalaise en 2014

Ce rapport documente une Matrice de comptabilité sociale (MCS) désagrégée de l'économie sénégalaise en 2014. Elle comprend 218 comptes répartis en 55 activités économiques (dont 14 comptes de ménages en tant que producteurs), 57 comptes de produits commercialisés et 9 comptes de produits autoconsommés, 3 catégories de travail distingué selon la qualification (qualifié, semi-qualifié et non-qualifié) dans 14 régions sénégalaises et 1 région représentant le reste du monde; 5 comptes de capital (agricoles, non agricoles, terre non irriguée, terre irriguée et élevage), 5 comptes d'impôts et taxes (directs, indirects, ventes, facteur travail et importations), 33 catégories de ménages représentatifs (régionalisés) et un compte de marges, un compte d'épargne-investissement, 4 comptes allouant les investissements (routes, irrigation, autres infrastructures, reste des investissements), un compte d'entreprises, du gouvernement et du reste du monde.JRC.D.4-Economics of Agricultur

Analysis of the impact of Croatia's accession to the EU on the agri-food sectors. A focus on trade and agricultural policies.

This report analyses the likely effects of Croatia's accession to the European Union (EU) on the agricultural and food sectors in terms of trade, production, employment and GDP for Croatia, the EU-27 and their main trading partners. Using a multi-country Computable General Equilibrium model (MAGNET) this study evaluates the impacts of the harmonisation of trade and agricultural policies that occur after this enlargement on July 1st, 2013. The results show that both Croatia's GDP and employment will slightly increase. The main conclusions point out significant market price effects as well as changes in trade patterns.JRC.J.4-Agriculture and Life Sciences in the Econom

Impact of Sub-Ambient Temperature on Aging Rate and Gas Separation Properties of Polymers of Intrinsic Microporosity

Aging in polymers of intrinsic microporosity has slowed exploitation due to a decay in performance over time since densification makes them unsuitable for industrial applications. This work aimed to study the impact of the operation and storage temperature on the gas separation properties and aging rates of PIM-1 self-standing films. The permeability, diffusivity, and solubility of the tested membranes were monitored through permeation tests for pure carbon dioxide and nitrogen at a maximum upstream pressure of 1.3 bar for temperatures ranging from −20 °C to 25 °C. This study found significant benefits in the operation of glassy polymeric membranes at low temperatures, resulting in a favourable trade-off in separation performance and a reduction in the aging rate by three orders of magnitude. This brings new opportunities for the industrial application of PIMs in innovative carbon capture processes

Can we translate vitamin D immunomodulating effect on innate and adaptive immunity to vaccine response?

Vitamin D (VitD), which is well known for its classic role in the maintenance of bone mineral density, has now become increasingly studied for its extra-skeletal roles. It has an important influence on the body's immune system and modulates both innate and adaptive immunity and regulates the inflammatory cascade. In this review our aim was to describe how VitD might influence immune responsiveness and its potential modulating role in vaccine immunogenicity. In the first instance, we consider the literature that may provide molecular and genetic support to the idea that VitD status may be related to innate and/or adaptive immune response with a particular focus on vaccine immunogenicity and then discuss observational studies and controlled trials of VitD supplementation conducted in humans. Finally, we conclude with some knowledge gaps surrounding VitD and vaccine response, and that it is still premature to recommend "booster" of VitD at vaccination time to enhance vaccine response

Policy impact assessment in developing countries using Social Accounting Matrices: the Kenya SAM 2014

This paper describes the structure and estimation of a Social Accounting Matrix (SAM) of Kenya for the year 2014. Among its specificities, this SAM includes a very high disaggregation of the agri-food sector and accounts for the double role of households as producers and consumers. Accounting for these characteristics is crucial to provide robust socioeconomic analysis in the context of developing countries. Indeed, this type of database is valuable to perform ex-ante evaluations of economic policies with various economic models and techniques. In this paper, we present an application with a linear multiplier analysis (backward linkages and value chain decomposition). The results show the capacity of the primary sector in Kenya to generate value added and employment, with this growth distributed more intensely in rural households whose main livelihood is semi-subsistence agriculture