Informed Consent Versus Presumed Consent The Role of the Family in Organ Donations

Two types of legislation underlie cadaveric organ donations: presumed consent (PC) and informed consent (IC). In informed consent countries, people are only donors when deceased if they registered to do so while alive. Conversely, in presumed consent countries, anybody is a potential donor when deceased. People have thus to register if they do not want to donate their body. PC has always been perceived as the “best” system for society in terms of organ donations whereas IC is supposed to be more ethical. However, in both systems, the family has a say, especially for the deceased who did not sign anything while alive. Taking the family decision into account, we show that the previous results may be reversed. The difference between both systems resides in the way an individual can commit to his/her will, eventually against the opinion of his/her family. IC can dominate PC in terms of organ donations whereas PC can be a more ethical system. In the general case, two opposite effects are at stake and the result depends on the extent to which people stay in the default situation. We discuss several causes of inactions (death taboo, procrastination, anticipated regret,...) and their impact on both the individual and the family.

Lattice Boltzmann schemes with relative velocities

In this contribution, a new class of lattice Boltzmann schemes is introduced and studied. These schemes are presented in a framework that generalizes the multiple relaxation times method of d'Humi\`eres. They extend also the Geier's cascaded method. The relaxation phase takes place in a moving frame involving a set of moments depending on a given relative velocity field. We establish with the Taylor expansion method that the equivalent partial differential equations are identical to the ones obtained with the multiple relaxation times method up to the second order accuracy. The method is then performed to derive the equivalent equations up to third order accuracy

On the stability of a relative velocity lattice Boltzmann scheme for compressible Navier-Stokes equations

This paper studies the stability properties of a two dimensional relative velocity scheme for the Navier-Stokes equations. This scheme inspired by the cascaded scheme has the particularity to relax in a frame moving with a velocity field function of space and time. Its stability is studied first in a linear context then on the non linear test case of the Kelvin-Helmholtz instability. The link with the choice of the moments is put in evidence. The set of moments of the cascaded scheme improves the stability of the d'Humi\`eres scheme for small viscosities. On the contrary, a relative velocity scheme with the usual set of moments deteriorates the stability

Convolution powers in the operator-valued framework

We consider the framework of an operator-valued noncommutative probability space over a unital C*-algebra B. We show how for a B-valued distribution \mu one can define convolution powers with respect to free additive convolution and with respect to Boolean convolution, where the exponent considered in the power is a suitably chosen linear map \eta from B to B, instead of being a non-negative real number. More precisely, the Boolean convolution power is defined whenever \eta is completely positive, while the free additive convolution power is defined whenever \eta - 1 is completely positive (where 1 stands for the identity map on B). In connection to these convolution powers we define an evolution semigroup related to the Boolean Bercovici-Pata bijection. We prove several properties of this semigroup, including its connection to the B-valued free Brownian motion. We also obtain two results on the operator-valued analytic function theory related to the free additive convolution powers with exponent \eta. One of the results concerns analytic subordination for B-valued Cauchy-Stieltjes transforms. The other gives a B-valued version of the inviscid Burgers equation, which is satisfied by the Cauchy-Stieltjes transform of a B-valued free Brownian motion.Comment: 33 pages, no figure

Partnerships aimed at adding value to organic residues on Réunion Island

The rational management of organic matter produced locally by agricultural, agro-industrial and urban units is a real challenge for Reunion Island. However, this organic matter represents an important opportunity for sugarcane farmers who are heavily dependent on the importation of mineral fertilisers. Four projects have been initiated to optimize the use of these resources from agronomic, economic and environmental perspectives. These projects propose to answer four major questions about the optimal use of organic matter resources to replace mineral fertilisers either totally or partially: 1) what are the environmental impacts; 2) what are their fertilising properties; 3) how to optimize fertilisation advice to farmers; and 4) how to manage the available materials? In response, CIRAD through the SOERE-PRO project, is assessing the environmental impacts of organic matter applications by means of a highly instrumented experimental system. This includes time domain reflectometry and use of tensiometers, lysimeters and an automated soil gas flux measurement system for N2O and CO2 determinations. This mechanism allows the impacts of organic matter to be followed within the soil, air, water and plant 'compartments'. At the same time, eRcane and CTICS, within the TERO project, are utilizing four test sites, corresponding to different soil and climate conditions, to characterize the composition of organic matter and evaluate their nitrogen (N) fertilising power. This will be done by determining apparent use coefficients and equivalences to fertiliser N. Closer to the farmers, the Ferti-Sol project of La Chambre d'Agriculture proposes to use soil analyses to develop balanced fertilisation trials with organic residues and mineral fertilisers. The use of these manures will be compared to the farmers' current fertilisation practices. The results will provide fertilisation advices that will allow for the farmers to improve their practices. Finally, in order to optimize the management of organic matter, the multi-partnership Gabir project, led by CIRAD, will analyze the biomass transfers between stakeholders. They will also simulate various valuation scenarios based on the principles of a circular economy. These four projects are conducted in partnership and complementarity by the following research and development organizations: CIRAD, eRcane, CTICS and Chambre d'Agriculture. This initiative reflects Reunion Island's intention for sustainable management of the territory resources over the long term, especially through agriculture

OUTLIERS IN THE SPECTRUM OF LARGE DEFORMED UNITARILY INVARIANT MODELS

44 pages, LaTeX, one figure. Several changes form the previous version, including a correction in Lemma 3.1 and the addition of several remarks and of a numerical example, kindly provided by Charles Bordenave. Same title as http://arxiv.org/abs/1207.5443, which it greatly expands.International audienceIn this paper we characterize the possible outliers in the spectrum of large deformed unitarily invariant additive and multiplicative models, as well as the eigenvectors corresponding to them. We allow both the non-deformed unitarily invariant model and the perturbation matrix to have non-trivial limiting spectral measures and spiked outliers in their spectrum. We uncover a remarkable new phenomenon: a single spike can generate asymptotically several outliers in the spectrum of the deformed model. The free subordination functions play a key role in this analysis

Variability of nitrogen use efficiency of urea in Réunion

In Reunion, sugarcane covers more than half of the cultivated area. Its production is highly dependent on the importation of mineral fertilisers such as nitrogen (N), a major driver for yield. Fertiliser materials from agro-industrial, urban and farming waste products (MAFOR) are locally available. Although these are important sources of nutrients, their fertiliser value, particularly N, remains unknown. The TERO project was launched in 2014 for this purpose. The behaviour of eight “MAFOR” products are being compared with urea (the most commonly used mineral fertiliser) via response curves. TERO has implemented four trials in sites in high-contrast production areas - an altitude gradient of more than 500 m, average minimum temperatures between 15.6 and 20.8 °C and maximum temperatures between 22.7 and 28.7 °C, rainfall variation of 3,500 mm and soils with variable physico-chemical properties. In each trial, the N requirements (X) were calculated from soil analysis results and based on the expected cane yield. Response curves were obtained from five treatments (0X, 0.5X, 0.75X, 0.9X, 1.5X) replicated three times. In the plant crop, half of the urea was buried at planting and the other half was spread on the soil surface four months later. Cane (including trash and tops) was harvested and weighed. The N content (NDumas) and N recovery was determined. Nitrogen use efficiency (NUE) values were calculated from the N response curves. Data from three trials were available for this poster. Nitrogen response curves and NUE were very different from site to site. The trial conducted in the north of the island, on a Nitisol at an altitude of 50 m, resulted in a response curve that was sigmoidal, with an NUE of 0.35. The trial in the west, on a brown Dystric Cambrisol (Humic) at an altitude of 570 m, resulted in a response curve that was also sigmoidal, but with an NUE of only 0.12. In contrast, the trial conducted on the eastern side of the island, on an Haplic Umbrisols at an altitude of 330 m, resulted in a linear response between 0X and 0.9X. The calculated NUE was 0.92, highlighting better recovery of urea. The variability in the responses to N, from one production area to another, justifies the diversity of trial sites in order to evaluate the NUE of the available MAFOR. The study will be conducted over two seven-year cane cycles to assess the direct and indirect effects of eight MAFOR products