Renormalization of the electron-phonon coupling in the one-band Hubbard model

We investigate the effect of electronic correlations on the coupling of electrons to Holstein phonons in the one-band Hubbard model. We calculate the static electron-phonon vertex within linear response of Kotliar-Ruckenstein slave-bosons in the paramagnetic saddle-point approximation. Within this approach the on-site Coulomb interaction U strongly suppresses the coupling to Holstein phonons at low temperatures. Moreover the vertex function does not show particularly strong forward scattering. Going to larger temperatures kT\sim t we find that after an initial decrease with U, the electron-phonon coupling starts to increase with U, confirming a recent result of Cerruti, Cappelluti, and Pietronero. We show that this behavior is related to an unusual reentrant behavior from a phase separated to a paramagnetic state upon decreasing the temperature.Comment: 4 pages, 6 figure

N-Cadherin cleavage during activated hepatic stellate cell apoptosis is inhibited by tissue inhibitor of metalloproteinase-1. [In supplement: 11th International Symposium on the Cells of the Hepatic Sinusoid and their Relation to Other Cells]

Apoptosis of hepatic stellate cells (HSC) has previously been shown to occur during spontaneous resolution of experimental liver fibrosis. TIMP-1 has also been shown to have a key role because of its ability to inhibit apoptosis of HSC via matrix metalloproteinase (MMP) inhibition. This has led to further study of novel substrates for MMPs that might impact on HSC survival. N-Cadherin is known to mediate cell-cell contacts in fibroblasts. In this study we demonstrate that N-Cadherin is expressed by activated rat HSC. Furthermore, during apoptosis of HSC, the N-Cadherin is cleaved into smaller fragments. Apoptosis of HSC may be inhibited by TIMP-1. This is associated with reduced fragmentation of N-Cadherin. N-Cadherin may have an important role in supporting HSC survival while N-Cadherin cleavage may play a part in promoting HSC apoptosis in recovery from liver fibrosis

Scott correction for large atoms and molecules in a self-generated magnetic field

We consider a large neutral molecule with total nuclear charge $Z$ in non-relativistic quantum mechanics with a self-generated classical electromagnetic field. To ensure stability, we assume that Z\al^2\le \kappa_0 for a sufficiently small $\kappa_0$, where \al denotes the fine structure constant. We show that, in the simultaneous limit $Z\to\infty$, \al\to 0 such that \kappa =Z\al^2 is fixed, the ground state energy of the system is given by a two term expansion $c_1Z^{7/3} + c_2(\kappa) Z^2 + o(Z^2)$. The leading term is given by the non-magnetic Thomas-Fermi theory. Our result shows that the magnetic field affects only the second (so-called Scott) term in the expansion

Présence de chimiorécepteurs sur l'aile des tsé-tsé (Diptera : Glossinidae)

Cette note signale pour la première fois l'existence de chimiorécepteurs sur les ailes des mouches tsé-tsé. Ceux-ci sont principalement localisés sur le milieu de la nervure costale. Leur morphologie est comparable à celle des chimiorécepteurs observés sur les pattes. Leur nombre ne différe pas entre les sexes comme pour les pattes, mais entre les espèces. Ceci suggère un rôle dans la perception chimique proche de l'environnement, par rapport aux chimiorécepteurs des pattes qui semblent impliqués dans le comportement sexuel. L'étude a été conduite sur six espèces ou sous-espèces de glossines. (Résumé d'auteur

Organizing product-oriented environmental management from a resource-based perspective

More and more the biophysical environment is being acknowledged as a critical business concern, while the environmental performance of products is becoming increasingly important to all parts of the product chain. Systematical attempts to decrease the environmental impact of a product throughout its life cycle could contribute to a firm's sustainable development potential, since product-oriented environmental management (POEM) addresses different themes of sustainable industrial development. POEM is defined as an approach to organizing a firm in such a way that improving the environmental performance of its products and processes becomes an integral part of both operations and strategy

L'archéologie française à l'étranger: Nouveaux enjeux de politique scientifique et de coopération internationale pour le Ministère des affaires étrangères et européennes

L'organisation et le financement de la recherche archéologique française hors du territoire national reposent pour une très large part sur le dispositif géré depuis plus d'un demi-siècle par le Ministère des Affaires Etrangères et Européennes : la Commission consultative de la recherche archéologique à l'étranger évalue et propose le financement des projets de recherche grâce à un appel d'offre annuel, les Instituts français de recherche à l'étranger, codirigés avec le CNRS, organisent dans bon nombre de pays hôtes la coordination des actions de recherche et l'accueil de chercheurs grâce à des structures pérennes. Cette double organisation, seule en France à être explicitement et uniquement dévolue à l'archéologie, prend en charge chaque année de 150 à 200 projets dans une organisation fortement internationalisée puisqu'elle permet à près de 1800 personnes, dont près de 800 non français, de travailler à l'étranger (chiffres année 2010). Elle répond avec une grande efficacité aux besoins des projets et des équipes qui s'en félicitent : une organisation administrative et gestionnaire légère permet une adaptation très rapide et souple aux conditions de travail à l'étranger ; un appel d'offre annuel totalement ouvert géographiquement et thématiquement laisse la capacité d'initiative aux acteurs de la discipline ; le soutien sur place des instituts et des services diplomatiques est un outil précieux pour la réalisation des projets en concertation avec les institutions et les collègues des pays hôtes. après avoir décrit le dispositif, le rapport traite quatre aspects : les relations entre les institutions françaises et étrangères intervenant dans la recherche archéologique à l'étranger les thématiques de recherche et l'évaluation des projets l'organisation et la réalisation des projets l'exploitation des projets à travers la production scientifique, la diffusion et la valorisation des résultats. Ces aspects nous permettent de concentrer l'attention sur les enjeux déterminants et les évolutions souhaitables du dispositif général

Uniqueness and Nondegeneracy of Ground States for (−Δ)sQ+Q−Qα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1} = 0 in R\mathbb{R}

We prove uniqueness of ground state solutions $Q = Q(|x|) \geq 0$ for the nonlinear equation $(-\Delta)^s Q + Q - Q^{\alpha+1}= 0$ in $\mathbb{R}$, where $0 < s < 1$ and $0 < \alpha < \frac{4s}{1-2s}$ for $s < 1/2$ and $0 < \alpha < \infty$ for $s \geq 1/2$. Here $(-\Delta)^s$ denotes the fractional Laplacian in one dimension. In particular, we generalize (by completely different techniques) the specific uniqueness result obtained by Amick and Toland for $s=1/2$ and $\alpha=1$ in [Acta Math., \textbf{167} (1991), 107--126]. As a technical key result in this paper, we show that the associated linearized operator $L_+ = (-\Delta)^s + 1 - (\alpha+1) Q^\alpha$ is nondegenerate; i.\,e., its kernel satisfies $\mathrm{ker}\, L_+ = \mathrm{span}\, \{Q'\}$. This result about $L_+$ proves a spectral assumption, which plays a central role for the stability of solitary waves and blowup analysis for nonlinear dispersive PDEs with fractional Laplacians, such as the generalized Benjamin-Ono (BO) and Benjamin-Bona-Mahony (BBM) water wave equations.Comment: 45 page

Neutralino Dark Matter in BMSSM Effective Theory

We study thermal neutralino dark matter in an effective field theory extension of the MSSM, called "Beyond the MSSM" (BMSSM) in Dine, Seiberg and Thomas (2007). In this class of effective field theories, the field content of the MSSM is unchanged, but the little hierarchy problem is alleviated by allowing small corrections to the Higgs/higgsino part of the Lagrangian. We perform parameter scans and compute the dark matter relic density. The light Higgsino LSP scenario is modified the most; we find new regions of parameter space compared to the standard MSSM. This involves interesting interplay between the WMAP dark matter bounds and the LEP chargino bound. We also find some changes for gaugino LSPs, partly due to annihilation through a Higgs resonance, and partly due to coannihilation with light stops in models that are ruled in by the new effective terms.Comment: 37 pages + appendi