Detection and discrimination of cosmological non-Gaussian signatures by multi-scale methods

Recent Cosmic Microwave Background (CMB) observations indicate that the temperature anisotropies arise from quantum fluctuations in the inflationary scenario. In the simplest inflationary models, the distribution of CMB temperature fluctuations should be Gaussian. However, non-Gaussian signatures can be present. They might have different origins and thus different statistical and morphological characteristics. In this context and motivated by recent and future CMB experiments, we search for, and discriminate between, different non-Gaussian signatures. We analyse simulated maps of three cosmological sources of temperature anisotropies: Gaussian distributed CMB anisotropies from inflation, temperature fluctuations from cosmic strings and anisotropies due to the kinetic Sunyaev-Zel'dovich (SZ) effect both showing a non-Gaussian character. We use different multi-scale methods, namely, wavelet, ridgelet and curvelet transforms. The sensitivity and the discriminating power of the methods is evaluated using simulated data sets. We find that the bi-orthogonal wavelet transform is the most powerful for the detection of non-Gaussian signatures and that the curvelet and ridgelet transforms characterise quite precisely and exclusively the cosmic strings. They allow us thus to detect them in a mixture of CMB + SZ + cosmic strings. We show that not one method only should be applied to understand non-Gaussianity but rather a set of different robust and complementary methods should be used.Comment: Accepted for publication in A&A. Paper with high resolution figures can be found at http://jstarck.free.fr/cmb03.pd

Antiviral-hyperactivation limiting therapeutics for the treatment of viral diseases and cancer

Current anti-HIV drugs target several of viral enzymes that HIV requires to replicate and survive. Hyperactivation of the immune system is now recognized as the major driver of progression to AIDS and of the emergence of both AIDS-defining and non-AIDS events which negatively impact upon morbidity and mortality despite fully suppressive ART. AV-HALTs are a new class of antiretrovirals that both reduce HIV replication and excessive immune activation. By targeting a human rather than a viral enzyme the chances of the virus developing resistance are decreased, an improvement over traditional antiretroviral drugs. The proof of concept for this new class of drugs was achieved with a Phase IIa study in which the HU/ddI combination (first generation AV-HALTs) safely achieved the goals established for the AV-HALT class. The idea of AV-HALTs was further expanded in order to join both the antiproliferative and antiviral activities into a single molecule. CDK9 inhibitors were tested with the goal to identify second generation AV-HALTs. Compounds with good toxicity and activity profile were moved to preclinical development and were tested for ADME properties and preliminary in vivo experiments in rodent species. In addition, CDK9 inhibitors were found to be active against other viruses such as HSV-1, HSV-2, EBV and HPV. This class of compounds also proved to inhibit proliferation of tumor cells both in vitro and in vivo

Evento “Ecologias Digitais do Sul”: novas epistemologias diante da Agenda Sustentável e às formas de produzir, consumir e comunicar, com focos em demarketing e educomunicação

Presentation text for the Extraprensa dossier: Digital Ecologies of the SouthTexto de presentación del dossier Extraprensa: Ecologías Digitales del SurTexto de apresentação para o dossiê da Extraprensa: Ecologias digitais do Su

Fiscal foresight and the effects of government spending

We study the effects of government spending by using a structural, large dimensional, dynamic factor model. We find that the government spending shock is non-fundamental for the variables commonly used in the structural VAR literature, so that its impulse response functions cannot be consistently estimated by means of a VAR. Government spending raises both consumption and investment, with no evidence of crowding out. The impact multiplier is 1.7 and the long run multiplier is 0.6

2011: the immune hallmarks of cancer

Ten years after the publication of the position paper “The hallmarks of cancer” (Hanahan and Weinberg Cell 100:57–70, 2000), it has become increasingly clear that mutated cells on their way to giving rise to a tumor have also to learn how to thrive in a chronically inflamed microenvironment, evade immune recognition, and suppress immune reactivity. Genetic and molecular definition of these three immune hallmarks of cancer offers the opportunity to learn how to deploy specific countermeasures to reverse the situation in favor of the immune system and, eventually, the patient. This new information could be channeled to address what seem to be the three major hallmarks for the immune control of cancer progression: effective procedures to activate immune reactivity; characterization of not-disposable oncoantigens; and counteraction of immune suppression

Macroeconomic shocks and the business cycle : evidence from a structural factor model

We use a dynamic factor model to provide a semi-structural representation for 101 quarterly US macroeconomic series. We find that (i) the US economy is well described by a number of structural shocks between two and six. Focusing on the four-shock specification, we identify, using sign restrictions, two non-policy shocks, demand and supply, and two policy shocks, monetary and fiscal. We obtain the following results. (ii) Both supply and demand shocks are important sources of fluctuations; supply prevails for GDP, while demand prevails for employment and inflation. (ii) Policy matters, Both monetary and fiscal policy shocks have sizeable effects on output and prices, with little evidence of crowding out; both monetary and fiscal authorities implement important systematic countercyclical policies reacting to demand shocks. (iii) Negative demand shocks have a large long-run positive effect on productivity, consistently with the Schumpeterian "cleansing" view of recessions

Testing for sufficient information in structural VARs

We derive necessary and sufficient conditions under which a set of variables is informationally sufficient, i.e. it contains enough information to estimate the structural shocks with a VAR model. Based on such conditions, we suggest a procedure to test for informational sufficiency. Moreover, we show how to amend the VAR if informational sufficiency is rejected. We apply our procedure to a VAR including TFP, unemployment and per-capita hours worked. We find that the three variables are not informationally sufficient. When adding missing information, the effects of technology shocks change dramatically