Evolution of the fine-structure constant in runaway dilaton models

We study the detailed evolution of the fine-structure constant $\alpha$ in the string-inspired runaway dilaton class of models of Damour, Piazza and Veneziano. We provide constraints on this scenario using the most recent $\alpha$ measurements and discuss ways to distinguish it from alternative models for varying $\alpha$. For model parameters which saturate bounds from current observations, the redshift drift signal can differ considerably from that of the canonical $\Lambda$CDM paradigm at high redshifts. Measurements of this signal by the forthcoming European Extremely Large Telescope (E-ELT), together with more sensitive $\alpha$ measurements, will thus dramatically constrain these scenarios.Comment: 11 pages, 4 figure

The pten–pi3k axis in cancer

The PI3K–AKT–mTOR signal transduction pathway regulates a variety of biological processes including cell growth, cell cycle progression and proliferation, cellular metabolism, and cytoskeleton reorganization. Fine-tuning of the phosphatidylinositol 3-kinase (PI3K) pathway signaling output is essential for the maintenance of tissue homeostasis and uncontrolled activation of this cascade leads to a number of human pathologies including cancer. Inactivation of the tumor suppressor phosphatase and tensin homologue deleted on Chromosome 10 (PTEN) and/or activating mutations in the proto-typical lipid kinase PI3K have emerged as some of the most frequent events associated with human cancer and as a result the PI3K pathway has become a highly sought-after target for cancer therapies. In this review we summarize the essential role of the PTEN–PI3K axis in controlling cellular behaviors by modulating activation of key proto-oncogenic molecular nodes and functional targets. Further, we highlight important functional redundancies and peculiarities of these two critical enzymes that over the last few decades have become a central part of the cancer research field and have instructed hundreds of pre-clinical and clinical trials to better cancer treatments

Boundary Controllability and Observability of a Viscoelastic String

In this paper we consider an integrodifferential system, which governs the vibration of a viscoelastic one-dimensional object. We assume that we can act on the system at the boundary and we prove that it is possible to control both the position and the velocity at every point of the body and at a certain time $T$, large enough. We shall prove this result using moment theory and we shall prove that the solution of this problem leads to identify a Riesz sequence which solves controllability and observability. So, the result as presented here are constructive and can lead to simple numerical algorithms

A novel technique to close large perforation of sinus membrane

Maxillary sinus floor elevation is generally accepted as a regenerative procedure to facilitate dental implants placement in the posterior atrophic maxilla. Although the sinus lift procedure is relatively safe, some potential problems could be occur. The most prevalent intraoperative complication is perforation of sinus membrane, which can lead to graft infection and early failure. The Aim of this work. Is to present a new technique to repair large perforation of sinus membrane. This case report. Is focused on a 10 mm perforation of sinus membrane occurred during preparation of the sinus window. The obliteration of the perforation was obtained by means of suturing sinus membrane with a resorbable material to the bone directly lateral to the osteotomy site. Sinus augmentation procedure could complete and the insertion of a graft was permitted

Intravital imaging reveals p53-dependent cancer cell death induced by phototherapy via calcium signaling.

One challenge in biology is signal transduction monitoring in a physiological context. Intravital imaging techniques are revolutionizing our understanding of tumor and host cell behaviors in the tumor environment. However, these deep tissue imaging techniques have not yet been adopted to investigate the second messenger calcium (Ca2+). In the present study, we established conditions that allow the in vivo detection of Ca2+ signaling in three-dimensional tumor masses in mouse models. By combining intravital imaging and a skinfold chamber technique, we determined the ability of photodynamic cancer therapy to induce an increase in intracellular Ca2+ concentrations and, consequently, an increase in cell death in a p53-dependent pathway

Dag-Rali

Ce terme désigne un important clan tributaire de la confédération des Kel-Ahaggar. Les Dag-Rali seraient les descendants de Takamat présentée soit comme la sœur cadette soit comme la servante de Tin-Hinan, ancêtre mythique des principaux groupes nobles (ou parfois des seuls Kel-Rela) de l’Ahaggar*. Selon la version la plus souvent reprise (Foucauld, 1951 p. 535), Takamat* serait arrivée dans l’Ahaggar en même temps que Tin-Hinan* et aurait eu deux filles. De l’aînée descendraient les Ihadanar..

Eseber

L’éseber (pl. isebrân) est une natte-paravent constituée de tiges de panic (Panicum turgidum Forsk.) reliées entre elles par de fines lanières de cuir. Ces nattes-paravent, d’une hauteur comprise entre 80 et 100 cm, mesurent de 5 à 10 mètres de long. A l’intérieur des tentes, déroulées le long des piquets, sous le vélum, elles protègent les occupants du vent, du sable et des regards indiscrets. Durant la journée, les isebrân servent aussi à enclore devant la tente un espace où l’on peut se ré..

Hadj Ahmed

El-Hadj Ahmed ag-el-Hadj-el-Bekri (Elkhaj Akhmed en tamâhaq) fut amenûkal de l’Ahaggar de 1861 à 1877. Il succéda à Ag-Mama ag Sidi et, à sa mort, fut remplacé à la tête des Kel-Ahaggar par Ahitaγel ag Mokhammed-Biska, fils de sa tante maternelle. L’accession au pouvoir Le premier amenûkal connu des Kel-Ahaggar fut Salah à qui succéda son fils Mokhammed el-Kheir lui même remplacé, à la fin du xviiie siècle, par son fils Sidi. Ce dernier épousa Kella, considérée comme une descendante de Tin-Hi..

The worldwide costs of marine protected areas

Declines in marine harvests, wildlife, and habitats have prompted calls at both the 2002 World Summit on Sustainable Development and the 2003 World Parks Congress for the establishment of a global system of marine protected areas (MPAs). MPAs that restrict fishing and other human activities conserve habitats and populations and, by exporting biomass, may sustain or increase yields of nearby fisheries. Here we provide an estimate of the costs of a global MPA network, based on a survey of the running costs of 83 MPAs worldwide. Annual running costs per unit area spanned six orders of magnitude, and were higher in MPAs that were smaller, closer to coasts, and in high-cost, developed countries. Models extrapolating these findings suggest that a global MPA network meeting the World Parks Congress target of conserving 20–30% of the world’s seas might cost between $5 billion and$19 billion annually to run and would probably create around one million jobs. Although substantial, gross network costs are less than current government expenditures on harmful subsidies to industrial fisheries. They also ignore potential private gains from improved fisheries and tourism and are dwarfed by likely social gains from increasing the sustainability of fisheries and securing vital ecosystem services