Ceramide 1-phosphate/ceramide, a switch between life and death

AbstractCeramide is a well-characterized sphingolipid metabolite and second messenger that participates in numerous biological processes. In addition to serving as a precursor to complex sphingolipids, ceramide is a potent signaling molecule capable of regulating vital cellular functions. Perhaps its major role in signal transduction is to induce cell cycle arrest, and promote apoptosis. In contrast, little is known about the metabolic or signaling pathways that are regulated by the phosphorylated form of ceramide. It was first demonstrated that ceramide-1-phosphate (C1P) had mitogenic properties, and more recently it has been described as potent inhibitor of apoptosis and inducer of cell survival. C1P and ceramide are antagonistic molecules that can be interconverted in cells by kinase and phosphatase activities. An appropriate balance between the levels of these two metabolites seems to be crucial for cell and tissue homeostasis. Switching this balance towards accumulation of one or the other may result in metabolic dysfunction, or disease. Therefore, the activity of the enzymes that are involved in C1P and ceramide metabolism must be efficiently coordinated to ensure normal cell functioning

Core excitation effects in halo nuclei using a transformed oscillator basis

A recent generalization of the Transformed Harmonic Oscillator basis, intended to consider core excitations in the structure of one nucleon halo nuclei, is applied to the break up of 11Be. The reaction studied is 11Be+208Pb at 69 MeV/nucleon. The experimental set up is designed to ensure pure dipole Coulomb excitations. Making use of the Equivalent Photon Method and the electromagnetic transition probabilities obtained with the transformed oscillator basis, a relevant contribution of the quadrupole excitations of the core is found. The inclusion of core excitations is, therefore, necessary for the correct extraction of the dipole electromagnetic transition probability of halo nuclei.Ministerio de Ciencia e Innovación FIS2011-28738-c02-01, FPA2009- 07653, FPA2009-08848, CSD2007-00042Junta de Andalucía FQM160, P07-FQM-0289

Stabilization method in two-body systems with core excitations

The validity of the stabilization method in core+valence systems including the possibility of exciting the core is studied. A pseudostate method, based on the transformed harmonic oscillator basis, is extended to include the core degrees of freedom. The method is applied to the case of 11Be structure considering the 0+ ground state and the 2+ first excited state of the 10Be core. The stabilization method is defined in terms of one parameter that can be chosen either discrete or continuous. In the application to 11Be, both cases are analyzed.Ministerio de Ciencia e Innovación FIS2011-28738-c02-01, FPA2009-07653, FPA2009-08848, CSD2007-00042Junta de Andalucía FQM160, P07-FQM-0289

Transfer to the continuum calculations of quasifree (p,pn) and (p,2p) reactions

Nucleon removal (p, pn) and (p, 2p) reactions at intermediate energies have gained renewed attention in recent years as a tool to extract information from exotic nuclei. The information obtained from these experiments is expected to be sensitive to deeper portions of the wave function of the removed nucleon than knockout reactions with heavier targets. In this contribution, we present calculations for (p, 2p) and (p, pn) reactions performed within the so-called transfer to the continuum method (TR*). Results for stable and unstable nuclei are presented, and compared with experimental data, when availabl

Influence of target deformation and deuteron breakup in ( d , p ) transfer reactions

Background: The effect of core excitations in transfer reactions of the form A ( d , p ) B has been reexamined by some recent works by using the Faddeev–Alt–Grassberger–Sandhas reaction formalism. The effect was found to affect significantly the calculated cross sections and to depend strongly and nonlinearly on the incident deuteron energy. Purpose: Our goal is to investigate these effects within a coupled-channel formulation of the scattering problem which, in addition to being computationally less demanding than the Faddeev counterpart, may help shed some light onto the physical interpretation of the cited effects. Method: We use an extended version of the continuum-discretized coupled-channel (CDCC) method with explicit inclusion of target excitations within a coupled-channel Born approximation (CDCC-BA) formulation of the transfer transition amplitude. We compare the calculated transfer cross sections with those obtained with an analogous calculation omitting the effect of target excitation. We consider also an adiabatic coupled-channel (ACC) method. Our working example is the 10 Be ( d , p ) 11 Be reaction. Results: We find that the two considered methods (CDCC-BA and ACC) reproduce fairly well the reported energy dependence of the core excitation effect. The main deviation from the pure three-body model calculation (i.e., omitting core excitations) is found to mostly originate from the destructive interference of the direct one-step transfer and the two-step transfer following target excitation. Conclusions: The proposed method; namely, the combination of the CDCC method and the CCBA formalism, provides a useful and accurate tool to analyze transfer reactions including explicitly, when needed, the effect of target excitations and projectile breakup. The method could be useful for other transfer reactions induced by weakly bound projectiles, including halo nuclei.Ministerio de Economía y Competitividad de España y Fondos FEDER. FIS2014-53448-C2-1-PPrograma Horizonte 2020 de la Unión Europea. 65400

Interplay of projectile breakup and target excitation in reactions induced by weakly bound nuclei

Reactions involving weakly bound nuclei require formalisms able to deal with continuum states. The majority of these formalisms struggle to treat collective excitations of the systems involved. For continuumdiscretized coupled channels (CDCC), extensions to include target excitation have been developed but have only been applied to a small number of cases.Junta de Andalucía FQM160 P07-FQM-02894Ministerio de Economía y Competitividad FIS2014-53448-C2-1-

Recent developments for the calculation of elastic and non-elastic breakup of weakly-bound nuclei

In this contribution, we review some recent theoretical advances for the calculation of breakup cross sections in reactions induced by weakly-bound nuclei.Ministerio de Economía y Competitividad FIS2013-41994-P, CSD2007-00042Junta de Andalucía FQM160, P07-FQM-02894European Commission 60037

Influence of target deformation and deuteron breakup in ( d , p ) transfer reactions

Background: The effect of core excitations in transfer reactions of the form A ( d , p ) B has been reexamined by some recent works by using the Faddeev–Alt–Grassberger–Sandhas reaction formalism. The effect was found to affect significantly the calculated cross sections and to depend strongly and nonlinearly on the incident deuteron energy. Purpose: Our goal is to investigate these effects within a coupled-channel formulation of the scattering problem which, in addition to being computationally less demanding than the Faddeev counterpart, may help shed some light onto the physical interpretation of the cited effects. Method: We use an extended version of the continuum-discretized coupled-channel (CDCC) method with explicit inclusion of target excitations within a coupled-channel Born approximation (CDCC-BA) formulation of the transfer transition amplitude. We compare the calculated transfer cross sections with those obtained with an analogous calculation omitting the effect of target excitation. We consider also an adiabatic coupled-channel (ACC) method. Our working example is the 10 Be ( d , p ) 11 Be reaction. Results: We find that the two considered methods (CDCC-BA and ACC) reproduce fairly well the reported energy dependence of the core excitation effect. The main deviation from the pure three-body model calculation (i.e., omitting core excitations) is found to mostly originate from the destructive interference of the direct one-step transfer and the two-step transfer following target excitation. Conclusions: The proposed method; namely, the combination of the CDCC method and the CCBA formalism, provides a useful and accurate tool to analyze transfer reactions including explicitly, when needed, the effect of target excitations and projectile breakup. The method could be useful for other transfer reactions induced by weakly bound projectiles, including halo nuclei.Ministerio de Economía y Competitividad de España y Fondos FEDER. FIS2014-53448-C2-1-PPrograma Horizonte 2020 de la Unión Europea. 65400

Study of the decomposition of Vacuum Gas Oils-Low Density Polyethylene blends: evolution of the gases

Presentado como póster en el 11th Mediterranean Congress of Chemical Engineering, Barcelona 2008. Resumen publicado en el libro de actas del congreso.The growth of the production and consumption of plastics has been increased drastically in this decade. An alternative approach of the tertiary recycling is based on the fact that it is possible to mix polymers of olefinic base (polyethylene, polypropylene) and of styrene base in the usual feed of the process of fluid catalytic cracking of hydrocarbons (FCC) in the refineries, and to turn them into products in the range of gasoline. Previous studies focused on the behaviour of different samples of vacuum gas oil (VGO), polyethylene (PE) and vacuum gas oil-polyethylene blends (VGO-PE) in the thermal and catalytic pyrolysis process, showed that the pyrolysis of the blends goes through two decomposition steps, being the first step related to the elimination of the VGO fraction, and the second to the pyrolysis of PE. Moreover, the presence of catalyst mainly affects the PE decomposition. In this work, the evolution with the temperature (or time) of the composition of the gases evolved in the thermal and catalytic pyrolysis of VGO, PE and a VGO-PE blend have been studied by GC/MS. The results obtained yield valuable information for designing processes of plastic recycling by this route, where the VGO-PE mixture can be treated in a unit similar to the industrial FCC unit, since the presence of polyethylene does not considerably affect the global composition of the gases with respect to the VGO, but adds an additional decomposition step at higher temperatures. Moreover, its presence favours the formation of iso-butane, propane, and butane, which form part of the liquefied petroleum gas (LP).Comisión de Investigación Científica y Tecnológica de la Secretaría de Estado de Educación, Universidades, Investigación y Desarrollo and the European Community (FEDER refunds) (CICYT PPQ2004-02187), Generalitat Valenciana (ACOMP06/162 and ACOMP/2007/094), and University of Alicante; Grupo de Procesado y Pirólisis de Polímeros (VIGROB099)

Reaction theory: status and perspectives

The current status of the reaction theory of nuclear collisions involving weakly-bound exotic nuclei is presented. The problem is addressed within the Continuum Discretized Coupled Channel (CDCC) framework, recalling its foundations and applications, as well as its connection with the Faddeev formalism. Recent developments and improvements of the method, such as core and target excitations and the extension to three-body projectiles, are presented. The use of the CDCC wave function in the calculation of inclusive breakup reactions is also introduce