PI3kinases in diabetes mellitus and its related complications

Recent studies have shown that phosphoinositide 3-kinases (PI3Ks) have become the target of many pharmacological treatments, both in clinical trials and in clinical practice. PI3Ks play an important role in glucose regulation, and this suggests their possible involvement in the onset of diabetes mellitus. In this review, we gather our knowledge regarding the effects of PI3K isoforms on glucose regulation in several organs and on the most clinically-relevant complications of diabetes mellitus, such as cardiomyopathy, vasculopathy, nephropathy, and neurological disease. For instance, PI3K α has been proven to be protective against diabetes-induced heart failure, while PI3K γ inhibition is protective against the disease onset. In vessels, PI3K γ can generate oxidative stress, while PI3K β inhibition is anti-thrombotic. Finally, we describe the role of PI3Ks in Alzheimer’s disease and ADHD, discussing the relevance for diabetic patients. Given the high prevalence of diabetes mellitus, the multiple effects here described should be taken into account for the development and validation of drugs acting on PI3Ks

Spherical orbit closures in simple projective spaces and their normalizations

Let G be a simply connected semisimple algebraic group over an algebraically closed field k of characteristic 0 and let V be a rational simple G-module of finite dimension. If G/H \subset P(V) is a spherical orbit and if X is its closure, then we describe the orbits of X and those of its normalization. If moreover the wonderful completion of G/H is strict, then we give necessary and sufficient combinatorial conditions so that the normalization morphism is a homeomorphism. Such conditions are trivially fulfilled if G is simply laced or if H is a symmetric subgroup.Comment: 24 pages, LaTeX. v4: Final version, to appear in Transformation Groups. Simplified some proofs and corrected minor mistakes, added references. v3: major changes due to a mistake in previous version

Gravitational waves from galaxy encounters

We discuss the emission of gravitational radiation produced in encounters of dark matter galactic halos. To this aim we perform a number of numerical simulations of typical galaxy mergers, computing the associated gravitational radiation waveforms as well as the energy released in the processes. Our simulations yield dimensionless gravitational wave amplitudes of the order of $10^{-13}$ and gravitational wave frequencies of the order of $10^{-16}$ Hz, when the galaxies are located at a distance of 10 Mpc. These values are of the same order as those arising in the gravitational radiation originated by strong variations of the gravitational field in the early Universe, and therefore, such gravitational waves cannot be directly observed by ground-based detectors. We discuss the feasibility of an indirect detection by means of the B-mode polarization of the Cosmic Microwave Background (CMB) induced by such waves. Our results show that the gravitational waves from encounters of dark matter galactic halos leave much too small an imprint on the CMB polarization to be actually observed with ongoing and future missions.Comment: 9 pages with revtex style, 3 ps figures; to be published in Physical Review

Alström Syndrome: Genetics and Clinical Overview

Alström syndrome is a rare autosomal recessive genetic disorder characterized by cone-rod dystrophy, hearing loss, childhood truncal obesity, insulin resistance and hyperinsulinemia, type 2 diabetes, hypertriglyceridemia, short stature in adulthood, cardiomyopathy, and progressive pulmonary, hepatic, and renal dysfunction. Symptoms first appear in infancy and progressive development of multi-organ pathology leads to a reduced life expectancy. Variability in age of onset and severity of clinical symptoms, even within families, is likely due to genetic background

Aplicação da dispersão da matriz em fase sólida (DMFS) na determinação residual de acaricidas em sangue bovino

A metodologia desenvolvida, DMFS-GC/MS, mostrou-se sensível, precisa e reprodutível, para analisar resíduos dos acaricidas cipermetrina, clorfenvinfos e fipronil em plasma bovino

CLOVER - A new instrument for measuring the B-mode polarization of the CMB

We describe the design and expected performance of Clover, a new instrument designed to measure the B-mode polarization of the cosmic microwave background. The proposed instrument will comprise three independent telescopes operating at 90, 150 and 220 GHz and is planned to be sited at Dome C, Antarctica. Each telescope will feed a focal plane array of 128 background-limited detectors and will measure polarized signals over angular multipoles 20 < l < 1000. The unique design of the telescope and careful control of systematics should enable the B-mode signature of gravitational waves to be measured to a lensing-confusion-limited tensor-to-scalar ratio r~0.005.Comment: 4 pages, 5 figures. To appear in the proceedings of the XXXVIXth Rencontres de Moriond "Exploring the Universe