Asymmetric Exclusion Process with Global Hopping

We study a one-dimensional totally asymmetric simple exclusion process with one special site from which particles fly to any empty site (not just to the neighboring site). The system attains a non-trivial stationary state with density profile varying over the spatial extent of the system. The density profile undergoes a non-equilibrium phase transition when the average density passes through the critical value 1-1/[4(1-ln 2)]=0.185277..., viz. in addition to the discontinuity in the vicinity of the special site, a shock wave is formed in the bulk of the system when the density exceeds the critical density.Comment: Published version (v2

Multicritical continuous random trees

We introduce generalizations of Aldous' Brownian Continuous Random Tree as scaling limits for multicritical models of discrete trees. These discrete models involve trees with fine-tuned vertex-dependent weights ensuring a k-th root singularity in their generating function. The scaling limit involves continuous trees with branching points of order up to k+1. We derive explicit integral representations for the average profile of this k-th order multicritical continuous random tree, as well as for its history distributions measuring multi-point correlations. The latter distributions involve non-positive universal weights at the branching points together with fractional derivative couplings. We prove universality by rederiving the same results within a purely continuous axiomatic approach based on the resolution of a set of consistency relations for the multi-point correlations. The average profile is shown to obey a fractional differential equation whose solution involves hypergeometric functions and matches the integral formula of the discrete approach.Comment: 34 pages, 12 figures, uses lanlmac, hyperbasics, eps

Fine roots distribution, light conditions and yield in a tree-based intercrop system

Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013."In tree-based intercrop systems (TBI), trees are planted in widely spaced rows to allow agricultural activities to continue. These agroforestry systems are new in Qu_bec but well known in Europe, USA and China (Baldy et al., 1993; Rivest and Olivier, 2007). The integration of trees into an agroforestry system has the potential to enhance soil fertility, reduce erosion, improve water quality, increase biodiversity and aesthetics, and sequester carbon (Jose, 2009; Montagnini and Nair, 2004). However, the presence of trees also results in aboveground and belowground interspecific interactions with crop, which can include competition, facilitation or complementarity (Jose et al., 2004; Rivest and Olivier, 2007; Van Noordwijk et al., 1996). In theory, TBI systems can be more productive than the respective monocultures if trees have the capacity to take resources like water and nutrients in deeper soil layers than those used by crops (Cannell et al., 1996)."--Introduction.L�a Bouttier (1), Alain Paquette (2), Christian Messier (2) and Alain Cogliastro (1) ; 1. Institut de Recherche en Biologie V�g�tale, 4101 Sherbrooke Est, Montr�al, QC H1X 2B2, Canada. 2. Universit� du Qu�bec a Montr�al, 270 Rue Saint Antoine Ouest, Montreal, QC H2Y 0A3, Canada.Includes bibliographical references

Coupling of hard dimers to dynamical lattices via random tensors

We study hard dimers on dynamical lattices in arbitrary dimensions using a random tensor model. The set of lattices corresponds to triangulations of the d-sphere and is selected by the large N limit. For small enough dimer activities, the critical behavior of the continuum limit is the one of pure random lattices. We find a negative critical activity where the universality class is changed as dimers become critical, in a very similar way hard dimers exhibit a Yang-Lee singularity on planar dynamical graphs. Critical exponents are calculated exactly. An alternative description as a system of `color-sensitive hard-core dimers' on random branched polymers is provided.Comment: 12 page

Critical and Tricritical Hard Objects on Bicolorable Random Lattices: Exact Solutions

We address the general problem of hard objects on random lattices, and emphasize the crucial role played by the colorability of the lattices to ensure the existence of a crystallization transition. We first solve explicitly the naive (colorless) random-lattice version of the hard-square model and find that the only matter critical point is the non-unitary Lee-Yang edge singularity. We then show how to restore the crystallization transition of the hard-square model by considering the same model on bicolored random lattices. Solving this model exactly, we show moreover that the crystallization transition point lies in the universality class of the Ising model coupled to 2D quantum gravity. We finally extend our analysis to a new two-particle exclusion model, whose regular lattice version involves hard squares of two different sizes. The exact solution of this model on bicolorable random lattices displays a phase diagram with two (continuous and discontinuous) crystallization transition lines meeting at a higher order critical point, in the universality class of the tricritical Ising model coupled to 2D quantum gravity.Comment: 48 pages, 13 figures, tex, harvmac, eps

Mechanism of Splicing Regulation of Spinal Muscular Atrophy Genes

Spinal muscular atrophy (SMA) is one of the major genetic disorders associated with infant mortality. More than 90% cases of SMA result from deletions or mutations of Survival Motor Neuron 1 (SMN1) gene. SMN2, a nearly identical copy of SMN1, does not compensate for the loss of SMN1due to predominant skipping of exon 7. However, correction of SMN2 exon 7 splicing has proven to confer therapeutic benefits in SMA patients. The only approved drug for SMA is an antisense oligonucleotide (Spinraza™/Nusinersen), which corrects SMN2 exon 7 splicing by blocking intronic splicing silencer N1 (ISS-N1) located immediately downstream of exon 7. ISS-N1 is a complex regulatory element encompassing overlapping negative motifs and sequestering a cryptic splice site. More than 40 protein factors have been implicated in the regulation of SMN exon 7 splicing. There is evidence to support that multiple exons of SMN are alternatively spliced during oxidative stress, which is associated with a growing number of pathological conditions. Here, we provide the most up to date account of the mechanism of splicing regulation of the SMN genes

Description d'une chambre photographique pour la prise de diagrammes de Debye˗Scherrer, d'échantillons portés à très basses températures

On décrit une chambre photographique pour la prise de diagrammes de Debye˗Scherrer d'échantillons portés à très basse température. Le système de refroidissement de l'échantillon se fait par passage d'un courant d'air très froid passant sur l'échantillon, un couple thermoélectrique permet de contrôler à tout instant la température de l'échantillon. On peut, avec le dispositif décrit, porter l'échantillon à des températures comprises entre + 200° C et — 155° C à ± 1° près. Le centrage de l'échantillon dans la chambre est réalisé par construction et ne peut donc être déréglé.Bouttier L., Dunoyer J.-M. Description d'une chambre photographique pour la prise de diagrammes de Debye˗Scherrer, d'échantillons portés à très basses températures. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 76, 1-3, 1953. pp. 79-85

Effet de deux conduites du pâturage sur les performances des vaches laitières, la valorisation des prairies et les restitutions d'azote

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Effet des conditions de pâturage et de l'apport de concentré sur les quantités ingérées par les vaches laitières

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Effet de la reduction de la fertilisation azotee sur la qualite de l'herbe selectionnee par les vaches laitieres

L'extensification en production fourragereNational audienc