Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments

This research is focused on secondary alkane sulfonates (SAS), anionic surfactants widely used in household applications that access aquatic environments mainly via sewage discharges.We studied their sorption capacity and anaerobic degradation in marine sediments, providing the first data available on this topic. SAS partition coefficients increased towards those homologues having longer alkyl chains(from up to 141 L kg 1 for C14 to up to 1753 L kg 1 for C17), which were those less susceptible to undergo biodegradation. Overall, SAS removal percentages reached up to 98% after 166 days of incubation using anoxic sediments. The degradation pathway consisted on the formation of sulfocarboxylic acids after an initial fumarate attack of the alkyl chain and successive b-oxidations. This is the first study showing that SAS can be degraded in absence of oxygen, so this new information should be taken into account for future environmental risk assessments on these chemicals

Local induction and provably total computable functions

Let I¦− 2 denote the fragment of Peano Arithmetic obtained by restricting the induction scheme to parameter free ¦2 formulas. Answering a question of R. Kaye, L. Beklemishev showed that the provably total computable functions of I¦− 2 are, precisely, the primitive recursive ones. In this work we give a new proof of this fact through an analysis of certain local variants of induction principles closely related to I¦− 2 . In this way, we obtain a more direct answer to Kaye’s question, avoiding the metamathematical machinery (reflection principles, provability logic,...) needed for Beklemishev’s original proof. Our methods are model–theoretic and allow for a general study of I¦− n+1 for all n ¸ 0. In particular, we derive a new conservation result for these theories, namely that I¦− n+1 is ¦n+2–conservative over I§n for each n ¸ 1.Ministerio de Ciencia e Innovación MTM2008–06435Ministerio de Ciencia e Innovación MTM2011–2684

Local Induction and Provably Total Computable Functions: A Case Study

Let IΠ−2 denote the fragment of Peano Arithmetic obtained by restricting the induction scheme to parameter free Π2 formulas. Answering a question of R. Kaye, L. Beklemishev showed that the provably total computable functions (p.t.c.f.) of IΠ−2 are, precisely, the primitive recursive ones. In this work we give a new proof of this fact through an analysis of the p.t.c.f. of certain local versions of induction principles closely related to IΠ−2 . This analysis is essentially based on the equivalence between local induction rules and restricted forms of iteration. In this way, we obtain a more direct answer to Kaye’s question, avoiding the metamathematical machinery (reflection principles, provability logic,...) needed for Beklemishev’s original proof.Ministerio de Ciencia e Innovación MTM2008–0643

Identificación de nuevos agentes reguladores del inflamasoma: posibilidades para el desarrollo de fármacos antiinflamatorios

El contenido de esta revisión parte de un conocimiento global sobre el inflamasoma. Comenzando por los receptores de reconocimiento de patrones o PRR, que pueden tener una localización transmembranal o bien en orgánulos intracelulares. Los PRR se unen a ligandos que van a permitir que se desencadene el proceso de regulación o activación de los inflamasomas. Hay distintos tipos clasificados, según su modo de activación, en canónicos y no canónicos y también en distintas familias. El más conocido es el inflamasoma NLRP3, que se trascribe en respuesta a diversos estímulos y en su ensamblaje participa ASC y caspasa-1, activándose la última y produciéndose la liberación de IL-1β e IL-18 que da lugar a procesos inflamatorios de muerte celular. Algunas enfermedades como la fibromialgia, las enfermedades inflamatorias intestinales y las enfermedades cardiovasculares son causadas por la activación del inflamasoma. El conocimiento del proceso que da lugar a la activación y regulación del inflamasoma abre una ventana para reconocer posibles agentes reguladores que permitan tratar las patologías en las que interviene. Actualmente se ha conocido el mecanismo de acción de moléculas como el levornidazol (que disminuye la liberación de ROS, el creosol que reduce la expresión de NLRP3 y de proIL-1β), el resveratrol (inhibidor de la α-tubulina desacetilasa), la melatonina (que presenta efectos inhibidores sobre NF- κβ, suprime la liberación de histonas extracelulares e impide la expresión de genes que traducen el NLRP3), partenolida y BH 11-7082 (con capacidad de alquilar restos de cisteína que inhiben la activación de NF- κβ), el aspartato y glutamato (que van a inhibir la transcripción de la proteína NLRP3 y de la pro-IL- 1β al activar los canales NMDA) y el γ-tocotrienol (que actúa inhibiendo la señalización de NF-κB).Universidad de Sevilla. Grado en Farmaci

Existentially Closed Models in the Framework of Arithmetic

We prove that the standard cut is definable in each existentially closed model of IΔ0 + exp by a (parameter free) П1–formula. This definition is optimal with respect to quantifier complexity and allows us to improve some previously known results on existentially closed models of fragments of arithmetic.Ministerio de Educación y Ciencia MTM2011–2684

Provably Total Primitive Recursive Functions: Theories with Induction

A natural example of a function algebra is R (T), the class of provably total computable functions (p.t.c.f.) of a theory T in the language of first order Arithmetic. In this paper a simple characterization of that kind of function algebras is obtained. This provides a useful tool for studying the class of primitive recursive functions in R (T). We prove that this is the class of p.t.c.f. of the theory axiomatized by the induction scheme restricted to (parameter free) Δ1(T)–formulas (i.e. Σ1–formulas which are equivalent in T to Π1–formulas). Moreover, if T is a sound theory and proves that exponentiation is a total function, we characterize the class of primitive recursive functions in R (T) as a function algebra described in terms of bounded recursion (and composition). Extensions of this result are related to open problems on complexity classes. We also discuss an application to the problem on the equivalence between (parameter free) Σ1–collection and (uniform) Δ1–induction schemes in Arithmetic. The proofs lean upon axiomatization and conservativeness properties of the scheme of Δ1(T)–induction and its parameter free version

Carlos Gardel. Su vida, su música, su época

Desde que en 1986 apostó la University of Pittsburgh Press por publicar The life, music & times of Carlos Gardel, resurgió mundialmente el tango como música pero también como un concepto. En aquella línea, el aporte del profesor Simon Collier fue crucial, pues por vez primera desde la academia se ahondaba en el estudio conjunto de la música y la biografía como un aporte para la historia cultural, convirtiendo al libro en un clásico

On the quantifier complexity of Δ n+1 (T)– induction

In this paper we continue the study of the theories IΔ n+1 (T), initiated in [7]. We focus on the quantifier complexity of these fragments and theirs (non)finite axiomatization. A characterization is obtained for the class of theories such that IΔ n+1 (T) is Π n+2 –axiomatizable. In particular, IΔ n+1 (IΔ n+1 ) gives an axiomatization of Th Π n+2 (IΔ n+1 ) and is not finitely axiomatizable. This fact relates the fragment IΔ n+1 (IΔ n+1 ) to induction rule for Δ n+1 –formulas. Our arguments, involving a construction due to R. Kaye (see [9]), provide proofs of Parsons’ conservativeness theorem (see [16]) and (a weak version) of a result of L.D. Beklemishev on unnested applications of induction rules for Π n+2 and Δ n+1 formulas (see [2]).Ministerio de Educación y Cultura DGES PB96-134