On rooted directed path graphs

An asteroidal triple is a stable set of three vertices such that each pair is connected by a path avoiding the neighborhood of the third vertex. An asteroidal quadruple is a stable set of four vertices such that any three of them is an asteroidal triple. Two non adjacent vertices are linked by a special connection if either they have a common neighbor or they are the endpoints of two vertex-disjoint chordless paths satisfying certain technical conditions. Cameron, Ho`ang, and L´evˆeque [DIMAP Workshop on Algorithmic Graph Theory, 67–74, Electron. Notes Discrete Math., 32, Elsevier, 2009] proved that if a pair of non adjacent vertices are linked by a special connection then in any directed path model T the subpaths of T corresponding to the vertices forming the special connection have to overlap and they force T to be completely directed in one direction between these vertices. Special connections along with the concept of asteroidal quadruple play an important role to study rooted directed path graphs, which are the intersection graphs of directed paths in a rooted directed tree. In this work we define other special connections; these special connections along with the ones defined by Cameron, Ho`ang, and L´evˆeque are nine in total, and we prove that every one forces T to be completely directed in one direction between these vertices. Also, we give a characterization of rooted directed path graphs whose rooted models cannot be rooted on a bold maximal clique. As a by-product of our result, we build new forbidden induced subgraphs for rooted directed path graphs.Fil: Tondato, Silvia Beatriz. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Matemáticas; ArgentinaFil: Gutierrez, Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Special asteroidal quadruple on directed path graph non rooted path graph

An asteroidal triple in a graph G is a set of three non- adjacent vertices such that for any two of them there exists a path be- tween them that does not intersect the neighborhood of the third. Special asteroidal triple in a graph G is an asteroidal triple such that each pair is linked by a special connection. A special asteroidal triples play a central role in a characterization of directed path graphs by Cameron, Hoáng and Lévêque. They also introduce a related notion of asteroidal quadru- ple and conjecture a characterization of rooted path graphs. In its original form this conjecture is not complete, still in leafage four, as was showed in. But, as suggested by the conjecture, a characterization by forbidding particular types of asteroidal quadruples may hold. We prove that the conjecture in the original form is true on directed path graphs with leafage four having two minimal separators with multiplicity two. Thus we build the family of forbidden subgraphs in this case.Sociedad Argentina de Informática e Investigación Operativ

Special asteroidal quadruple on directed path graph non rooted path graph

An asteroidal triple in a graph G is a set of three non- adjacent vertices such that for any two of them there exists a path be- tween them that does not intersect the neighborhood of the third. Special asteroidal triple in a graph G is an asteroidal triple such that each pair is linked by a special connection. A special asteroidal triples play a central role in a characterization of directed path graphs by Cameron, Hoáng and Lévêque. They also introduce a related notion of asteroidal quadru- ple and conjecture a characterization of rooted path graphs. In its original form this conjecture is not complete, still in leafage four, as was showed in. But, as suggested by the conjecture, a characterization by forbidding particular types of asteroidal quadruples may hold. We prove that the conjecture in the original form is true on directed path graphs with leafage four having two minimal separators with multiplicity two. Thus we build the family of forbidden subgraphs in this case.Sociedad Argentina de Informática e Investigación Operativ

Influence of temperature on liquid - liquid equilibrium of methanol + toluene + hexane ternary system at atmospheric pressure

Abstract Liquid-liquid equilibrium of methanol + toluene+ hexane ternary system at 278.15,283.15, 288.15 and 293.15 K are reported. The effect of the temperature on liquid-liquidequilibrium is discussed. All chemicals were quantified by gas chromatography using athermal conductivity detector. Experimental data for the ternary system are compared withvalues calculated by the NRTL and UNIQUAC equations. It is found that the UNIQUACequation fitted to the experimental data is more accurate than the NRTL model for thisternary system for all temperatures studied.Fil: Veliz, Jonatan Hernan. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); ArgentinaFil: Cases, Alicia Marta. Universidad Nacional de Tucumán; ArgentinaFil: Varas Gutierrez, Constanza Geraldine. Universidad Nacional de Tucumán; ArgentinaFil: Gramajo, Monica Beatriz. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); Argentin

Mechanisms involved in the remyelinating effect of sildenafil

Remyelination occurs in demyelinated lesions in multiple sclerosis (MS) and pharmacological treatments that enhance this process will critically impact the long term functional outcome in the disease. Sildenafil, a cyclic GMP (cGMP)-specific phosphodiesterase 5 inhibitor (PDE5-I), is an oral vasodilator drug extensively used in humans for treatment of erectile dysfunction and pulmonary arterial hypertension. PDE5 is expressed in central nervous system (CNS) neuronal and glial populations and in endothelial cells and numerous studies in rodent models of neurological disease have evidenced the neuroprotective potential of PDE5-Is. Using myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) as a MS model, we previously showed that daily administration of sildenafil starting at peak disease rapidly ameliorates clinical symptoms while administration at symptoms onset prevents disease progression. These beneficial effects of the drug involved down-regulation of adaptive and innate immune responses, protection of axons and oligodendrocytes (OLs) and promotion of remyelination. In this work we have investigated mechanisms involved in the remyelinating effect of sildenafil. Using demyelinated organotypic cerebellar slice cultures we demonstrate that sildenafil stimulates remyelination by direct effects on CNS cells in a nitric oxide (NO)-cGMP-protein kinase G (PKG)-dependent manner. We also show that sildenafil treatment enhances OL maturation and induces expression of the promyelinating factor ciliary neurotrophic factor (CNTF) in spinal cord of EAE mice and in cerebellar slice cultures. Furthermore, we demonstrate that sildenafil promotes a M2 phenotype in bone marrow derived macrophages (BMDM) and increases myelin phagocytosis in these cells and in M2 microglia/macrophages in the spinal cord of EAE mice. Taken together these data indicate that promotion of OL maturation directly or through induction of growth factor expression, regulation of microglia/macrophage inflammatory phenotype and clearance of myelin debris may be relevant mechanisms involved in sildenafil enhancement of remyelination in demyelinated tissue and further support the contention that this well tolerated drug could be useful for ameliorating MS pathology

Tratamiento psicológico para el afrontamiento del cáncer de mama. Estudio comparativo entre estrategias de aceptación y de control cognitivo

The aim of current study was to analyze the psychological disorders associated with the diagnosis, treatment and consequences of breast cancer through the functional dimension of Emotional Avoidance, as well as to provide some empirical support for the usefulness of the Acceptance and Commitment Therapy (ACT) in this domain. Specifically, the impact of acceptance-based and cognitive-control-based strategies was compared, with the purpose of obtaining a better understanding of the elements that account for the changes observed with the respective psychological strategies. Twelve women diagnosed and treated with breast cancer who assisted to the Spanish Association against Cancer and who met certain selection criteria were randomly assigned to one of two treatment conditions: six women received an ACT-based protocol which addressed acceptance strategies and six women received a Cognitive-based protocol which addressed cognitive control strategies. Each treatment consisted of 8 sessions, 3 individual sessions and 5 group sessions; 3 women integrated each treatment group. Measures on anxiety, depression, life quality and affected valued life areas were obtained at pre- and post-intervention. Additionally, three follow-up were taken, at 3, 6 and 12 months. Results showed a higher impact of the ACT-based intervention, mainly when long-term changes were considered (12 months follow-up). Other remarkable finding was that the changes observed in the ACT condition were associated to a behavioural activation, even when discomfort and suffering were present.El objetivo principal de este estudio clínico es analizar los problemas psicológicos derivados del diagnóstico, tratamientos y secuelas del cáncer de mama como Trastorno de Evitación Experiencial (TEE) y aportar datos sobre las posibilidades de una intervención basada en la Terapia de Aceptación y Compromiso (ACT). Se pretende delimitar la eficacia de estrategias específicas de aceptación y de control cognitivo, definiendo más ajustadamente qué tipos de cambios propician unas estrategias en comparación con otras. 12 mujeres diagnosticadas y tratadas por cáncer de mama que acudían a la Asociación Española Contra el Cáncer y que cubrían criterios de selección, fueron asignadas al azar a dos condiciones de tratamiento, una basada en ACT, cuyo eje fue la estrategia de aceptación y otra basada en la terapia cognitiva, cuyo eje fueron las estrategias de control cognitivo. El tratamiento estuvo formado por 8 sesiones, 3 individuales y 5 grupales. Los grupos de tratamiento estuvieron formados por 3 mujeres. Se tomaron medidas de ansiedad, depresión, calidad de vida y áreas importantes afectadas, antes y después de la intervención (medidas pre, post test) y se realizaron tres seguimientos, a los 3, a los 6 y a los 12 meses. Los resultados mostraron una mayor repercusión de la intervención basada en ACT, especialmente cuando se tienen en cuenta los cambios a largo plazo (al año de seguimiento). También destaca que los cambios de la condición de ACT se centran en la activación conductual aún en presencia de malestar

La aplicación de la terapia de aceptación y compromiso (act) en el tratamiento de problemas psicológicos asociados al cáncer

El sufrimiento que se deriva verbalmente del hecho de padecer una enfermedad de cáncer es una circunstancia a la que se enfrentan todos los pacientes en esa situación. Sin embargo, y a pesar del impacto psicológico que engendra tal circunstancia, el curso de la vida de los pacientes se ve afectado por el afrontamiento ante los miedos, preocupaciones, recuerdos negativos y pensamientos sobre lo que ocurrirá. El afrontamiento con gran credibilidad en tales eventos privados conduce a una limitación y empobrecimiento vital que incrementa el sufrimiento personal. El Trastorno de Evitación Experiencial (TEE) sería un componente central en tales casos que se define por la rigidez conductual frente a los eventos privados. La Terapia de Aceptación y Compromiso (ACT) se está mostrando efectiva para alterar los contextos verbales que tienen atrapado al paciente en el TEE y, por tanto, promueve la flexibilidad conductual. El presente artículo sólo tiene como objetivo una exposición breve de la intervención de ACT con pacientes de cáncer de mama.The suffering correlated to having cancer is an experience that most patients confront. However, in spite of the psychological impact of such an event, the course of life is affected by the way patients cope with fears, worries, negative memories and thoughts about the future. High believability with such private events occur when a patient behaves according to them and, consequently, his or her life becomes limited and impoverished. Experiential Avoidance Disorder (EAD) is a core component in such cases and it is defined by behavioural rigidity. Acceptance and Commitment Therapy (ACT) is being shown effective in altering the verbal contexts that define EAD and, consequently, in promoting behavioral flexibility. The present paper is aimed only to briefly expose ACT interventions with breast-cancer patient

Análisis de la eficiencia de las políticas contra la desertificación llevada a cabo en la cuenca del río Guadalentin mediante Análisis Envolvente de Datos (DEA)

Mediante análisis envolvente de datos (DEA) CCR-input-orientado y DEA con ponderación cruzada se ha analizado la eficiencia de las diversas actuaciones aplicadas en ocho municipios de la cuenca del río Guadalentín, en búsqueda de la mejor política aplicada entre los años 1978 y 2003. Con el análisis CCR-input-orientado se han detectado los municipios claramente ineficientes y las causas de ineficiencia. Mediante el segundo análisis se ha obtenido una valoración de la eficiencia global de cada municipio y se ha podido estudiar la contribución unitaria de cada recurso en cada término municipal