Towards an Ashtekar formalism in eight dimensions

We investigate the possibility of extending the Ashtekar theory to eight dimensions. Our approach relies on two notions: the octonionic structure and the MacDowell-Mansouri formalism generalized to a spacetime of signature 1+7. The key mathematical tool for our construction is the self-dual (antiself-dual) four-rank fully antisymmetric octonionic tensor. Our results may be of particular interest in connection with a possible formulation of M-theory via matroid theory.Comment: 15 pages, Latex, minor changes, to appear in Class. Quantum Gra

Pursuing Gravitational S-Duality

Recently a strong-weak coupling duality in non-abelian non-supersymmetric theories in four dimensions has been found. An analogous procedure is reviewed, which allows to find the `dual action' to the gauge theory of dynamical gravity constructed by the MacDowell-Mansouri model plus the superposition of a $\Theta$ term.Comment: Invited paper to appear in the special issue of the `Journal of Chaos, Solitons and Fractals' on: "Superstrings, M,F,S,... Theory" (M.S. El Naschie and C. Castro, editors), 19 pages, LaTeX file, no figure

Self-dual gravity and self-dual Yang-Mills in the context of Macdowell-Mansouri formalism

In this work we propose an action which unifies self-dual gravity and self-dual Yang-Mills in the context of the Macdowell-Mansouri formalism. We claim that such an action may be used to find the S-dual action for both self-dual gravity and self-dual Yang-Mills.Comment: 8 pages, Revtex, no figures, submitted to Phys. Rev.

Gravitational Duality in MacDowell-Mansouri Gauge Theory

Strong-weak duality invariance can only be defined for particular sectors of supersymmetric Yang-Mills theories. Nevertheless, for full non-Abelian non-supersymmetric theories, dual theories with inverted couplings, have been found. We show that an analogous procedure allows to find the dual action to the gauge theory of gravity constructed by the MacDowell-Mansouri model plus the superposition of a $\Theta$ term.Comment: 9 pages, LaTeX, no figure

Laminin and Fibronectin Treatment Leads to Generation of Dendritic Cells with Superior Endocytic Capacity

Copyright: 2010 Garcı´a-Nieto et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Sampling the microenvironment at sites of microbial exposure by dendritic cells ( DC) and their subsequent interaction with T cells in the paracortical area of lymph nodes are key events for initiating immune responses. Most of our knowledge of such events in human is based on in vitro studies performed in the absence of extracellular matrix (ECM) proteins. ECM in basement membranes and interstitial spaces of different tissues, including lymphoid organs, plays an important role in controlling specific cellular functions such as migration, intracellular signalling and differentiation. The aim of this study was, therefore, to investigate the impact of two abundant ECM components, fibronectin and laminin, on the phenotypical and functional properties of DC and how that might influence DC induced T-cell differentiation. Methodology/Principal Findings: Human monocyte derived DC were treated with laminin and fibronectin for up to 48 hours and their morphology and phenotype was analyzed using scanning electron microscopy, flow cytometry and real time PCR. The endocytic ability of DC was determined using flow cytometry. Furthermore, co-culture of DC and T cells were established and T cell proliferation and cytokine profile was measured using H(3)-thymidine incorporation and ELISA respectively. Finally, we assessed formation of DC-T cell conjugates using different cell trackers and flow cytometry. Our data show that in the presence of ECM, DC maintain a 'more immature' phenotype and express higher levels of key endocytic receptors, and as a result become significantly better endocytic cells, but still fully able to mature in response to stimulation as evidenced by their superior ability to induce antigen-specific T cell differentiation. Conclusion: These studies underline the importance of including ECM components in in vitro studies investigating DC biology and DC-T cell interaction. Within the context of antigen specific DC induced T cell proliferation, inclusion of ECM proteins could lead to development of more sensitive assays.Peer reviewedFinal Published versio

Melatonin Modulation of Radiation and Chemotherapeutics-induced Changes on Differentiation of Breast Fibroblasts

Melatonin exerts oncostatic actions and sensitizes tumor cells to chemotherapeutics or radiation. In our study, we investigated the e ects of docetaxel, vinorelbine, and radiation on human breast fibroblasts and its modulation by melatonin. Docetaxel or vinorelbine inhibits proliferation and stimulates the di erentiation of breast preadipocytes, by increasing C/EBP and PPAR expression and by downregulating tumor necrosis factor (TNF ), interleukin 6 (IL-6), and IL-11 expression. Radiation inhibits both proliferation and di erentiation through the downregulation of C/EBP and PPAR and by stimulating TNF expression. In addition, docetaxel and radiation decrease aromatase activity and expression by decreasing aromatase promoter II and cyclooxygenases 1 and 2 (COX-1 and COX-2) expression. Melatonin potentiates the stimulatory e ect of docetaxel and vinorelbine on di erentiation and their inhibitory e ects on aromatase activity and expression, by increasing the stimulatory e ect on C/EBP and PPAR expression and the downregulation of antiadipogenic cytokines and COX expression. Melatonin also counteracts the inhibitory e ect of radiation on di erentiation of preadipocytes, by increasing C/EBP and PPAR expression and by decreasing TNF expression. Melatonin also potentiates the inhibitory e ect exerted by radiation on aromatase activity and expression by increasing the downregulation of promoter II, and COX-1 and COX-2 expression. Our findings suggest that melatonin modulates regulatory e ects induced by chemotherapeutic drugs or radiation on preadipocytes, which makes it a promising adjuvant for chemotherapy and radiotherapy sensibilization.Funding: This work was supported by a grant from the Spanish Economy and Competitiveness Ministry (SAF2016-77103-P) and from Instituto de Investigación Sanitaria Valdecilla (IDIVAL) (APG/12)

Gold(i)-catalyzed nucleophilic cyclization of β-monosubstituted o-(alkynyl)styrenes: a combined experimental and computational study

The stereospecific gold(I)-catalyzed nucleophilic cyclization of β-monosubstituted o-(alkynyl)styrenes to produce C-1 functionalized 1H-indenes including challenging substrates and nucleophiles, such as β-(cyclo)alkyl-substituted o-(alkynyl)styrenes and a variety of alcohols as well as selected electron-rich aromatics, is reported. DFT calculations support the stereochemical outcome of the process that involves the formation of a key cyclopropyl gold carbene intermediate through a regiospecific 5-endo cyclization.Ministerio de Economía y Competitividad (MINECO) and FEDER (CTQ2016-75023-C2-1-P and 2-P), and Junta de Castilla y León and FEDER (BU291P18) and Xunta de Galicia (ED431C 2017/70 and ED431E 2018/07

GEHEP 010 study: Prevalence and distribution of hepatitis B virus genotypes in Spain (2000–2016)

[Objective] To study the prevalence and distribution of HBV genotypes in Spain for the period 2000–2016.[Methods] Retrospective study recruiting 2559 patients from 17 hospitals. Distribution of HBV genotypes, as well as sex, age, geographical origin, mode of transmission, HDV-, HIV- and/or HCV-coinfection, and treatment were recorded.[Results] 1924 chronically HBV native Spanish patients have been recruited. Median age was 54 years (IQR: 41–62), 69.6% male, 6.3% HIV-coinfected, 3.1% were HCV-coinfected, 1.7% HDV-co/superinfected. Genotype distribution was: 55.9% D, 33.5% A, 5.6% F, 0.8% G, and 1.9% other genotypes (E, B, H and C). HBV genotype A was closely associated with male sex, sexual transmission, and HIV-coinfection. In contrast, HBV genotype D was associated with female sex and vertical transmission. Different patterns of genotype distribution and diversity were found between different geographical regions. In addition, HBV epidemiological patterns are evolving in Spain, mainly because of immigration. Finally, similar overall rates of treatment success across all HBV genotypes were found.[Conclusions] We present here the most recent data on molecular epidemiology of HBV in Spain (GEHEP010 Study). This study confirms that the HBV genotype distribution in Spain varies based on age, sex, origin, HIV-coinfection, geographical regions and epidemiological groups.This study has been funded in part by the funds of the research project GEHEP-2018-010, granted by the Hepatitis Group of the Spanish Society of Infectious Diseases and Clinical Microbiology (Grupo de Hepatitis de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica, GEHEP/SEIMC)

Orientaciones para la implementación de la Cátedra de Paz con enfoque de cultura ciudadana : lineamientos para la implementación de políticas, programas y proyectos educativos

La Secretaría de Educación del Distrito de Bogotá, D. C. (SED) presenta a los colegios estas Orientaciones para la implementación de la Cátedra de Paz con enfoque de cultura ciudadana, con las cuales se les invita a reflexionar y generar diálogos sobre por qué es importante una educación para la paz en el contexto particular de su escuela, de la ciudad y del país

Guía de práctica clínica para el manejo de covid-19 en el seguro social del Perú (EsSalud)

Introduction: Since the beginning of the COVID-19 pandemic, different drugs and medications have been used for the prevention and treatment of COVID-19 infection. Likewise, various investigations have been carried out to evaluate the efficacy and safety of these interventions, many of which have been shown to generate more harm than benefit for the patient, for this reason it is necessary to standardize the management of adult patients with COVID-19 in our context. Objective: To provide evidence-based clinical recommendations for the management of adults with COVID-19. Methods: A guideline development group (GEG) was formed that included medical specialists and methodologists. For its elaboration, GEG decided to carry out a rapid adaptation of the Guide for the care of critical adult patients with COVID-19 in the Americas of the Pan American Health Organization (PAHO) as well as to carry out searches for novo questions. For the formulation of the recommendations, the evidence frameworks for the decision (EtD) of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology were developed. Results: This CPG addressed 28 clinical questions, divided into three topics: prevention, diagnosis and management. Based on these questions, 33 recommendations (16 strong and 17 conditional), 26 good clinical practices (GCP) and 2 flowcharts were formulated. This CPG was published in its third version in December 2021 Conclusion: This article summarizes the methodology and evidence-based conclusions of the CPG for the management of adults with COVID 19 in EsSalud.Introducción: Desde el inicio de la pandemia por el COVID-19 se han utilizado distintos fármacos y medicamentos para la prevención y tratamiento de la infección por COVID-19. Asimismo, se han desarrollado diversas investigaciones que evalúan la eficacia y seguridad de estas intervenciones, muchas de las cuales han demostrado generar más daño que beneficio para el paciente, por tal motivo es necesario estandarizar el manejo del paciente adulto con COVID-19 en nuestro contexto. Objetivo: Proveer recomendaciones clínicas basadas en evidencia para el manejo del adulto con COVID-19. Métodos: Se conformó un grupo elaborador de la guía (GEG) que incluyó médicos especialistas y metodólogos. El Para su elaboración se GEG decidió realizar una adaptación rápida de la Guía para el cuidado de pacientes adultos críticos con COVID-19 en las Américas de la Organización Panamericana de la Salud (OPS) así como realizar búsquedas para preguntas de novo. Para la formulación de las recomendaciones se elaboró los marcos de evidencia para la decisión (EtD) de la metodología Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Resultados: La presente GPC abordó 28 preguntas clínicas, divididas en tres temas: prevención, diagnóstico y manejo. En base a dichas preguntas se formularon 33 recomendaciones (16 fuertes y 17 condicionales), 26 buenas prácticas clínicas (BPC) y 2 flujogramas. Esta GPC se publicó en su tercera versión en diciembre del 2021 Conclusión: El presente artículo resume la metodología y las conclusiones basadas en evidencias de la GPC para el manejo del adulto con COVID 19 en EsSalud