Restructuring of the "Macaronesia" biogeografic unit: a marine multi-taxon biogeographical approach

The Azores, Madeira, Selvagens, Canary Islands and Cabo Verde are commonly united under the term “Macaronesia”. This study investigates the coherency and validity of Macaronesia as a biogeographic unit using six marine groups with very different dispersal abilities: coastal fishes, echinoderms, gastropod molluscs, brachyuran decapod crustaceans, polychaete annelids, and macroalgae. We found no support for the current concept of Macaronesia as a coherent marine biogeographic unit. All marine groups studied suggest the exclusion of Cabo Verde from the remaining Macaronesian archipelagos and thus, Cabo Verde should be given the status of a biogeographic subprovince within the West African Transition province. We propose to redefine the Lusitanian biogeographical province, in which we include four ecoregions: the South European Atlantic Shelf, the Saharan Upwelling, the Azores, and a new ecoregion herein named Webbnesia, which comprises the archipelagos of Madeira, Selvagens and the Canary Islandsinfo:eu-repo/semantics/publishedVersio

Activated Random Walkers: Facts, Conjectures and Challenges

We study a particle system with hopping (random walk) dynamics on the integer lattice $\mathbb Z^d$. The particles can exist in two states, active or inactive (sleeping); only the former can hop. The dynamics conserves the number of particles; there is no limit on the number of particles at a given site. Isolated active particles fall asleep at rate $\lambda > 0$, and then remain asleep until joined by another particle at the same site. The state in which all particles are inactive is absorbing. Whether activity continues at long times depends on the relation between the particle density $\zeta$ and the sleeping rate $\lambda$. We discuss the general case, and then, for the one-dimensional totally asymmetric case, study the phase transition between an active phase (for sufficiently large particle densities and/or small $\lambda$) and an absorbing one. We also present arguments regarding the asymptotic mean hopping velocity in the active phase, the rate of fixation in the absorbing phase, and survival of the infinite system at criticality. Using mean-field theory and Monte Carlo simulation, we locate the phase boundary. The phase transition appears to be continuous in both the symmetric and asymmetric versions of the process, but the critical behavior is very different. The former case is characterized by simple integer or rational values for critical exponents ($\beta = 1$, for example), and the phase diagram is in accord with the prediction of mean-field theory. We present evidence that the symmetric version belongs to the universality class of conserved stochastic sandpiles, also known as conserved directed percolation. Simulations also reveal an interesting transient phenomenon of damped oscillations in the activity density

Twenty-six years of HIV science: an overview of anti-HIV drugs metabolism

From the identification of HIV as the agent causing AIDS, to the development of effective antiretroviral drugs, the scientific achievements in HIV research over the past twenty-six years have been formidable. Currently, there are twenty-five anti-HIV compounds which have been formally approved for clinical use in the treatment of AIDS. These compounds fall into six categories: nucleoside reverse transcriptase inhibitors (NRTIs), nucleotide reverse transcriptase inhibitors (NtRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), cell entry inhibitors or fusion inhibitors (FIs), co-receptor inhibitors (CRIs), and integrase inhibitors (INIs). Metabolism by the host organism is one of the most important determinants of the pharmacokinetic profile of a drug. Formation of active or toxic metabolites will also have an impact on the pharmacological and toxicological outcomes. Therefore, it is widely recognized that metabolism studies of a new chemical entity need to be addressed early in the drug discovery process. This paper describes an overview of the metabolism of currently available anti-HIV drugs.Da identificação do HIV como o agente causador da AIDS, ao desenvolvimento de fármacos antirretrovirais eficazes, os avanços científicos na pesquisa sobre o HIV nos últimos vinte e seis anos foram marcantes. Atualmente, existem vinte e cinco fármacos anti-HIV formalmente aprovados pelo FDA para utilização clínica no tratamento da AIDS. Estes compostos são divididos em seis classes: inibidores nucleosídeos de transcriptase reversa (INTR), inibidores nucleotídeos de transcriptase reversa (INtTR), inibidores não-nucleosídeos de transcriptase reversa (INNTR), inibidores de protease (IP), inibidores da entrada celular ou inibidores de fusão (IF), inibidores de co-receptores (ICR) e inibidores de integrase (INI). O metabolismo consiste em um dos maiores determinantes do perfil farmacocinético de um fármaco. A formação de metabólitos ativos ou tóxicos terá impacto nas respostas farmacológicas ou toxicológicas do fármaco. Portanto, é amplamente reconhecido que estudos do metabolismo de uma nova entidade química devem ser realizados durante as fases iniciais do processo de desenvolvimento de fármacos. Este artigo descreve uma abordagem do metabolismo dos fármacos anti-HIV atualmente disponíveis na terapêutica

Status Report Of The Schenberg Gravitational Wave Antenna

Here we present a status report of the Schenberg antenna. In the past three years it has gone to a radical upgrading operation, in which we have been installing a 1K pot dilution refrigerator, cabling and amplifiers for nine transducer circuits, designing a new suspension and vibration isolation system for the microstrip antennas, and developing a full set of new transducers, microstrip antennas, and oscillators. We are also studying an innovative approach, which could transform Schenberg into a broadband gravitational wave detector.3631Aguiar, O.D., (2002) Class. Quantum Grav., 19, p. 1949Aguiar, O.D., (2004) Class. Quantum Grav., 21, pp. S457Aguiar, O.D., (2005) Class. Quantum Grav., 22, pp. S209Aguiar, O.D., (2006) Class. Quantum Grav., 23, pp. S239Aguiar, O.D., (2008) Class. Quantum Grav., 25, p. 114042Costa, C.A., (2008) Class. Quantum Grav., 25, p. 184002Johnson, W.W., Merkowitz, S.M., (1993) Phys. Rev. Lett., 70, p. 2367Coccia, E., Lobo, J.A., Ortega, J.A., (1995) Phys. Rev. D, 52, p. 3735Thorne, K.S., (1978) Phys. Rev. Lett., 40, p. 667Tobar, M.E., Ivanov, E.N., Blair, D.G., (2000) Gen. Rel. Grav., 32, p. 1799De Waard, (2005) Class. Quantum Grav., 22, pp. S215Vinet, J.-Y., (2010) Research in Astron Astrophys., 10, p. 956Costa, C.A., Aguiar, O.D., Magalhães, N.S., (2004) Class. Quantum Grav., 21, pp. S827Forward, R.L., (1971) Gen. Rel. Grav., 2, p. 149Eardley, D.M., Lee, D.L., Lightman, A.P., Wagoner, R.V., Will, C.M., (1973) Phys. Rev. Lett., 30, p. 884Bianchi, M., Coccia, E., Colacino, C.N., Fafone, V., Fucito, F., (1996) Class. Quantum Grav., 13, p. 2865Andrade, L.A., (2009) Microwave and Optical Tech. Lett., 51, p. 1120Furtado, S.R., (2012), in preparationIvanov, E.N., Hartnett, J.G., Tobar, M.E., (2000) IEEE Trans. Ultrason., Ferroelect., Freq. Contr., 47, p. 1526Pimentel, G.L., (2008) J. Phys. Conf. Series, 122, p. 012028Aguiar, (2009) Int. J. Modern Phys. D, 18, p. 2317Furtado, S.R., (2009), Ph.D. Thesis at INPE, not publishedBraginsky, V.B., Vorontsov, Y.I., Thorne, K.S., (1980) Science, 209, p. 547Thorne, K.S., The Quantum Limit for Gravitational-Wave Detectors and Methods of Circumventing It (1979) Sources of Gravitational Waves, p. 49. , ed. L L Smarr, Cambridge University Press, Cambridge, US