Astrophysical S17(0) factor extraction from breakup of 8B on 58Ni at energies near the Coulomb barrier

We have performed continuum-discretized coupled channels (CDCC) calculations of the breakup of 8B on 58Ni and direct proton transfer for the 8B+58Ni system at laboratory energies of 20-28.4 MeV. The influence of the 7Be core-target optical potential (OP) on the breakup cross section was investigated. Elastic scattering angular distributions for the 7Be+58Ni and 8B+58Ni systems at five different energies around the Coulomb barrier were studied, and a reasonable energy-independent OP for each system was obtained. Using these OPs and two different 7Be-p relative motion wave functions, and summing breakup and direct proton transfer contributions, we were able to fit the experimental cross section at a 8B laboratory energy of 25.75 MeV. We calculated the excitation function for the 7Be emission in the 8B+58Ni reaction, where 7Be products were measured at the forward angle θlab=45° in the energy interval Elab=20-28.4 MeV. In view of the peripheral character of the B8 breakup reaction at near-barrier energies, we could extract the asymptotic normalization coefficient for the 7Be-p system, which was found to be CBe-p,p3/22=0.543±0.027 fm-1. Finally, the astrophysical S17(0) factor was found to be S17(0)=20.8±1.1 eV b.Ministerio de Ciencia e Innovación FPA2006-13807-c02-01Programa Consolider-Ingenio 2010 CSD2007-0004

Reaction mechanisms in the scattering of 8 Li on 208 Pb around the Coulomb barrier

We present an analysis of the reaction 8 Li + 208 Pb , which has been recently measured at energies around the Coulomb barrier. The study is focused on the elastic and one-neutron removal channels. The elastic angular distribution has been analyzed by means of the optical model and coupled-channels method. The measured 7 Li yield has been assumed to come from the one-neutron transfer reaction 208 Pb ( 8 Li , 7 Li ) 209 Pb and the breakup reaction 8 Li + 208 Pb → n + 7 Li + 208 Pb . For the former, an analysis in terms of the distorted wave Born approximation and coupled-channels Born approximation (CCBA) methods has been performed. For the breakup reaction, a generalization of the CCBA method has been used, in which the final states are described as n + 208 Pb continuum states. Transfer and breakup are then treated consistently. The summed angular distribution for the two processes reproduces the shape and absolute magnitude of the measured 7 Li distribution. We conclude that most of the measured 7 Li yield comes from the one-neutron transfer channel. We also show that the elastic scattering is notably affected by the strong coupling to transfer channels.Fundaçao para a Ciência e a Tecnología (FCT) de Portugal. POCTI/36282/99Ministerio de Ciencia y Tecnología de España. FPA2002-04181-C04-0

LA INVERSIÓN EN ACTIVOS FIJOS REALES PRODUCTIVOS: INCENTIVOS Y OBSTÁCULOS TRIBUTARIOS

RESUMENLas inversiones empresariales dirigidasa mejorar los procesos y a reducircostos, en ciertos casos, suscitan dificultadesde interpretación contablefrente a la jurídica impositiva. Estecaso describe la situación que afrontóSugar S.A. al utilizar la deducción tributariaespecial del 40% del valor desus inversiones efectivas realizadas,para disminuir la base de liquidacióny a su vez su impuesto de renta. LaAdministración de Impuestos rechazaparte de la deducción y notifica sanción.El caso deja al lector la tareade realizar el análisis que lleve aencontrar la solución que debe asumirla dirección de la compañía y queminimice costos y riesgos.Deducciones, Activos Fijos RealesProductivos, Inversión, RequerimientoEspecial, Declaración de Renta.

Conducting Polymers Films Deposited on Carbon Steel and Their Interaction with Crude Oil

The formation of scale/solids deposits inside the pipelines is a frequent problem in the petrochemical industry. These scales can be organic as the asphaltenes and inorganic as the accumulations of salts, which apart from blocking the inside of the pipes can also cause a change in the integrity of the steel. Therefore, it is necessary to avoid the conditions where deposition occurs, together with chemical and mechanical methods of remediation to mitigate the deposition. In this work we intend to use conductive polymers in order to inhibit the deposition of asphaltenes on carbon steel surfaces, by using polypyrrole (PPy) as material capable of conducting electrical current. The electrodeposition of PPy on carbon steel were performed by cyclic voltammetry (CV) and chronoamperometry (CA). The results showed that under certain experimental conditions it is possible to make a PPy film with adequate characteristics. Important factors were the grip and electrochemical stability of the formed film on steel, which depends on the electrosynthesis technique and in some cases favoured by a pre-treatment with a 10% HNO3 solution applied to the steel prior to electropolymerization. The PPy films deposited with pre-treatment completely covered the steel surface and showed better stability, adherence and generated a hydrophobic material

Deciphering the roadmap of in vivo reprogramming toward pluripotency

Differentiated cells can be converted into pluripotent stem cells by expressing the transcription factors OCT4, SOX2, KLF4, and MYC (OSKM) in a process known as reprogramming. Here, using single-cell RNA sequencing of pancreas undergoing reprogramming, we identify markers along the trajectory from acinar cell identity to pluripotency. These markers allow direct in situ visualization of cells undergoing dedifferentiation and acquiring features of early and advanced intermediate reprogramming. We also find that a fraction of cells do not dedifferentiate upon OSKM expression and are characterized by stress markers of the REG3 and AP-1 families. Importantly, most markers of intermediate reprogramming in the pancreas are also observed in stomach, colon, and cultured fibroblasts expressing OSKM. Among them is LY6A, a protein characteristic of progenitor cells and generally upregulated during tissue repair. Our roadmap defines intermediate reprogramming states that could be functionally relevant for tissue regeneration and rejuvenation.Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved

Grupos de trabajo de SCELE

La formación de Grupos de trabajo, en el marco de la Sociedad Científica de Enfermería, facilitará el cumplimiento de los objetivos y fines de esta Sociedad. La constitución del Grupo de trabajo de SCELE destinado a la Docencia e Investigación (GDI) se propuso desde la Junta Directiva de SCELE (Vocalías de Docencia y de Investigación), en la asamblea ordinaria del 26 de febrero de 2009. La constitución efectiva fue el día 9 de marzo de 2009. Su contribución es indispensable para el avance de la Enfermería como ciencia. Además, constituye un elemento de difusión de resultados basados en revisiones sistemáticas, aportando rigor científico a las recomendaciones que elaboren. Esta es la Misión del Grupo de Docencia y de Investigación de SCELE (GDI)

Towards an eco-friendly coffee rust control : compilation of natural alternatives from a nutritional and antifungal perspective

Hemileia vastatrix (HV) is the pathogen responsible for the coffee leaf rust (CLR) disease that has spread globally. CLR causes losses of up to a billion dollars annually and affects all types of crops regardless of their production regime (organic or inorganic). Additionally, smallholders produce approximately 80% of coffee in developing countries. The condition causes losses of up to a billion dollars annually. It affects all types of crops regardless of their production regime (organic or inorganic). Approximately 80% of coffee is produced by smallholders in developing countries. Until the 90s, shaded-production systems and native varieties were encouraged; however, the rapid spread of CLR has forced farmers to migrate towards inorganic schemes, mainly due to a lack of knowledge about natural alternatives to pesticides that can be implemented to control HV. Therefore, the purpose of this article is to compile the currently existing options, emphasizing two key factors that guarantee efficient rust control: selective fungicidal activity against HV and the nutrition of coffee crops. Thus, by comprehending how these natural compounds (such as plant, bacteria, fungi, animals, or algae metabolites) impact coffee rust proliferation. Furthermore, since a various range of biochar effects contributes to the control of foliar fungal pathogens through modification of root exudates, soil properties, and nutrient availability, which influence the growth of antagonist microorganisms, we present a review of the pathogen-suppressive effects of biochar, and new control strategies suitable for organic schemes can be developed.Publisher PDFPeer reviewe

In vascular smooth muscle cells paricalcitol prevents phosphate-induced Wnt/β-catenin activation

The present study investigates the differential effect of two vitamin D receptor agonists, calcitriol and paricalcitol, on human aortic smooth muscle cells calcification in vitro. Human vascular smooth muscle cells were incubated in a high phosphate (HP) medium alone or supplemented with either calcitriol 10−8M (HP + CTR) or paricalcitol 3·10−8 M (HP + PC). HP medium induced calcification, which was associated with the upregulation of mRNA expression of osteogenic factors such as bone morphogenetic protein 2 (BMP2), Runx2/Cbfa1, Msx2, and osteocalcin. In these cells, activation of Wnt/β-catenin signaling was evidenced by the translocation of β-catenin into the nucleus and the increase in the expression of direct target genes as cyclin D1, axin 2, and VCAN/versican. Addition of calcitriol to HP medium (HP + CTR) further increased calcification and also enhanced the expression of osteogenic factors together with a significant elevation of nuclear β-catenin levels and the expression of cyclin D1, axin 2, and VCAN. By contrast, the addition of paricalcitol (HP + PC) not only reduced calcification but also downregulated the expression of BMP2 and other osteoblastic phenotype markers as well as the levels of nuclear β-catenin and the expression of its target genes. The role of Wnt/β-catenin on phosphate- and calcitriol-induced calcification was further demonstrated by the inhibition of calcification after addition of Dickkopf-related protein 1 (DKK-1), a specific natural antagonist of the Wnt/β-catenin signaling pathway. In conclusion, the differential effect of calcitriol and paricalcitol on vascular calcification appears to be mediated by a distinct regulation of the BMP and Wnt/β-catenin signaling pathways

Inventario de localidades con evidencias de paleosuperficies en Paraguay

El geopatrimonio de Paraguay es muy variado, tiene un gran valor científico y en muchos casos estético, constituyéndose así en un recurso susceptible de ser aprovechado mediante el uso turístico/recreativo. Una parte importante de este capital geológico está compuesto por afloramientos rocosos que se corresponden con superficies antiguas, labradas por la erosión en distintos lapsos pre-terciarios (King, 1956). El presente trabajo incluye un inventario, simplificado en cuanto a lo descriptivo, de los sitios dentro del territorio paraguayo, en donde se ha constatado con mayor o menor certeza, la exposición superficial de estas paleosuperficies.Facultad de Ciencias Naturales y Muse

Formación de taumasita en morteros hidráulicos mediante la deposición de SO2 atmosférico

Sulphation of mortars and concretes is a function of diverse environmental factors (SO2 aerosol, temperature, etc) as well as some material characteristics. One of the phases that could be formed as consequence of the sulphation of the hydraulic binder is thaumasite. In this paper different hydraulic mortars have been exposed to laboratory exposure chambers in order to reproduce thaumasite formation due to atmospheric SO2. Under the laboratory exposure conditions, thaumasite was formed in hydraulic lime mortars, and mortars elaborated with ordinary Portland cement as well as mineralized white portland cement. However, thaumasite was not formed in mortars made of lime and pozzolan. The first product formed as a result of the SO2-mortar interaction was gypsum. Gypsum reacted with calcite and C-S-H gel, present in the samples, giving place to thaumasite. Low temperature promotes thaumasite formation.La sulfatación de morteros y hormigones depende de las condiciones ambientales (SO2 aerosol, temperatura, etc.), así como de las características del material. Una de las fases que se puede formar como consecuencia de la sulfatación de los ligantes hidráulicos es la taumasita. En este trabajo se han expuesto diferentes morteros hidráulicos en cámaras de laboratorio con el fin de reproducir la formación de taumasita por efecto del SO2 atmosférico. Bajo las condiciones de laboratorio se formó taumasita en los morteros de cal hidráulica y en los morteros fabricados con cemento portland y cemento blanco mineralizado. Sin embargo, cuando el ligante utilizado en los morteros fue cal y puzolana, no se formó taumasita. El yeso fue el primer producto formado en la interacción entre los morteros y el SO2. A continuación, este yeso reaccionó con la calcita y el gel C-S-H dando lugar a la formación de taumasita. Las bajas temperaturas favorecieron la formación de taumasita