55 research outputs found
Interactions between the RepB initiator protein of plasmid pMV158 and two distant DNA regions within the origin of replication
Plasmids replicating by the rolling circle mode usually possess a single site for binding of the initiator protein at the origin of replication. The origin of pMV158 is different in that it possesses two distant binding regions for the initiator RepB. One region was located close to the site where RepB introduces the replication-initiating nick, within the nic locus; the other, the bind locus, is 84 bp downstream from the nick site. Binding of RepB to the bind locus was of higher affinity and stability than to the nic locus. Contacts of RepB with the bind and nic loci were determined through high-resolution footprinting. Upon binding of RepB, the DNA of the bind locus follows a winding path in its contact with the protein, resulting in local distortion and bending of the double-helix. On supercoiled DNA, simultaneous interaction of RepB with both loci favoured extrusion of the hairpin structure harbouring the nick site while causing a strong DNA distortion around the bind locus. This suggests interplay between the two RepB binding sites, which could facilitate loading of the initiator protein to the nic locus and the acquisition of the appropriate configuration of the supercoiled DNA substrate
A SRS2 homolog from Arabidopsis thaliana disrupts recombinogenic DNA intermediates and facilitates single strand annealing
Genetic and biochemical analyses of SRS2 homologs in fungi indicate a function in the processing of homologous recombination (HR) intermediates. To date, no SRS2 homologs have been described and analyzed in higher eukaryotes. Here, we report the first biochemical characterization of an SRS2 homolog from a multicellular eukaryote, the plant Arabidopsis thaliana. We studied the basic properties of AtSRS2 and were able to show that it is a functional 3′- to 5′-helicase. Furthermore, we characterized its biochemical function on recombinogenic intermediates and were able to show the unwinding of nicked Holliday junctions (HJs) and partial HJs (PX junctions). For the first time, we demonstrated strand annealing activity for an SRS2 homolog and characterized its strand pairing activity in detail. Our results indicate that AtSRS2 has properties that enable it to be involved in different steps during the processing of recombination intermediates. On the one hand, it could be involved in the unwinding of an elongating invading strand from a donor strand, while on the other hand, it could be involved in the annealing of the elongated strand at a later step
The Interdomain Linker of AAV-2 Rep68 Is an Integral Part of Its Oligomerization Domain: Role of a Conserved SF3 Helicase Residue in Oligomerization
The four Rep proteins of adeno-associated virus (AAV) orchestrate all aspects of its viral life cycle, including transcription regulation, DNA replication, virus assembly, and site-specific integration of the viral genome into the human chromosome 19. All Rep proteins share a central SF3 superfamily helicase domain. In other SF3 members this domain is sufficient to induce oligomerization. However, the helicase domain in AAV Rep proteins (i.e. Rep40/Rep52) as shown by its monomeric characteristic, is not able to mediate stable oligomerization. This observation led us to hypothesize the existence of an as yet undefined structural determinant that regulates Rep oligomerization. In this document, we described a detailed structural comparison between the helicase domains of AAV-2 Rep proteins and those of the other SF3 members. This analysis shows a major structural difference residing in the small oligomerization sub-domain (OD) of Rep helicase domain. In addition, secondary structure prediction of the linker connecting the helicase domain to the origin-binding domain (OBD) indicates the potential to form α-helices. We demonstrate that mutant Rep40 constructs containing different lengths of the linker are able to form dimers, and in the presence of ATP/ADP, larger oligomers. We further identified an aromatic linker residue (Y224) that is critical for oligomerization, establishing it as a conserved signature motif in SF3 helicases. Mutation of this residue critically affects oligomerization as well as completely abolishes the ability to produce infectious virus. Taken together, our data support a model where the linker residues preceding the helicase domain fold into an α-helix that becomes an integral part of the helicase domain and is critical for the oligomerization and function of Rep68/78 proteins through cooperative interaction with the OBD and helicase domains
Clinical phenotypes of acute heart failure based on signs and symptoms of perfusion and congestion at emergency department presentation and their relationship with patient management and outcomes
Objective
To compare the clinical characteristics and outcomes of patients with acute heart failure (AHF) according to clinical profiles based on congestion and perfusion determined in the emergency department (ED).
Methods and results
Overall, 11 261 unselected AHF patients from 41 Spanish EDs were classified according to perfusion (normoperfusion = warm; hypoperfusion = cold) and congestion (not = dry; yes = wet). Baseline and decompensation characteristics were recorded as were the main wards to which patients were admitted. The primary outcome was 1-year all-cause mortality; secondary outcomes were need for hospitalisation during the index AHF event, in-hospital all-cause mortality, prolonged hospitalisation, 7-day post-discharge ED revisit for AHF and 30-day post-discharge rehospitalisation for AHF. A total of 8558 patients (76.0%) were warm+ wet, 1929 (17.1%) cold+ wet, 675 (6.0%) warm+ dry, and 99 (0.9%) cold+ dry; hypoperfused (cold) patients were more frequently admitted to intensive care units and geriatrics departments, and warm+ wet patients were discharged home without admission. The four phenotypes differed in most of the baseline and decompensation characteristics. The 1-year mortality was 30.8%, and compared to warm+ dry, the adjusted hazard ratios were significantly increased for cold+ wet (1.660; 95% confidence interval 1.400-1.968) and cold+ dry (1.672; 95% confidence interval 1.189-2.351). Hypoperfused (cold) phenotypes also showed higher rates of index episode hospitalisation and in-hospital mortality, while congestive (wet) phenotypes had a higher risk of prolonged hospitalisation but decreased risk of rehospitalisation. No differences were observed among phenotypes in ED revisit risk.
Conclusions
Bedside clinical evaluation of congestion and perfusion of AHF patients upon ED arrival and classification according to phenotypic profiles proposed by the latest European Society of Cardiology guidelines provide useful complementary information and help to rapidly predict patient outcomes shortly after ED patient arrival
Identification of teaching skills in the implementation of training plans for university teaching staff
[ES] Este artículo presenta el proyecto desarrollado durante el año 2011 por las unidades y centros de
formación de las universidades públicas catalanas. El proyecto se orienta a la mejora de la calidad del
sistema de educación superior y de la actividad del profesorado universitario mediante planes de
formación específicamente diseñados con esta finalidad, centrándose primeramente en la identificación
de competencias docentes definidas por la comunidad académica. Partiendo del contexto de
implementación del Espacio Europeo de Educación Superior se identifican aquellas competencias propias
de la función docente, para que posteriormente puedan ser adquiridas, desarrolladas y evaluadas
mediante la formación, identificando modelos, estrategias, instrumentos y recursos que lo permitan. El
proceso de identificación de las competencias docentes del profesorado universitario se ha desarrollado
partiendo de una revisión bibliográfica del estado del arte, para posteriormente ser modificada y validada
por grupos de discusión conformados por expertos en competencias y formación docente. Los
resultados de identificación de dichas competencias han sido finalmente refrendados mediante una encuesta respondida por una muestra representativa de la comunidad académica de las ocho
universidades públicas catalanas. El objetivo fundamental del proyecto que aquí presentamos no es otro
que el de contribuir a una formación de calidad del profesorado universitario, que permita la
adquisición, desarrollo y evaluación de las competencias que, como docente, gran parte de la comunidad
académica considera que debe poseer para el ejercicio de su labor profesional, definidas como:
interpersonal, metodológica, comunicativa, de planificación y gestión de la docencia, de trabajo en
equipo y de innovación.[EN] This article present the project developed in 2011 by units and training centers from all public
universities in Catalonia. The project is devised towards the quality improvement of the higher
education system and of the activity undertaken by the faculty at the university. In order to achieve
these objectives, it focuses on the identification of teaching skills, defined by the academic community
through training programs specifically designed for this purpose. Taking the implementation of the
European Higher Education as starting point, the project intends to analyze the skills considered to
belong by nature to the teaching task, as well as to define the necessary procedures to acquire, develop
and evaluate them through training. At the same time it seeks to identify models, strategies, tools and
resources. To this identification process we will make the necessary bibliographical research, in which
the criteria of teaching excellence will allow us to select a representative sample of teachers. The
selection will be performed through a survey and its quality will be validated by experts. The primary
objective of the project shown here is basically to contribute to the quality training of university
teachers, allowing the acquisition, development and evaluation of the skills considered essential by the
academic community, in order to properly undertake their professional tasks, defined as: interpersonal,
methodology, communication, planning and management of teaching, teamwork and innovation.Torra Bitlloch, I.; De Corral Manuel De Villena, I.; Pérez Cabrera, MJ.; Pagès Costas, T.; Valderrama Valles, E.; Màrquez Cebrian, MD.; Sabaté Díaz, S.... (2012). Identificación de competencias docentes que orienten el desarrollo de planes de formación dirigidos a profesorado universitario. REDU. Revista de Docencia Universitaria. 10(2):21-56. https://doi.org/10.4995/redu.2012.6096OJS2156102Aylett, R. & Gregory, K. (1997). Criteria for teaching competence and teaching excellence in Higher Education. London: Lalmer Press.Cano, E. (2005). Cómo mejorar las competencias de los docentes. Guía para la autoevaluación y el desarrollo de las competencias del profesorado. Colección desarrollo profesional del profesorado. Barcelona: Grao.Fielden, J. (2001). "Higher education staff development continuing mission". En Thematic dabte of the follow-up to the World Conference on High Education. UNESCO.Galán, A. (2007). El perfil del profesor universitario. Situación actual y retos de futuro. Madrid: Ediciones Encuentro.GIFD -Grup Interuniversitari de Formació Docent (2011). "Identificación, desarrollo y evaluación de competencias docentes en la aplicación de planes de formación dirigidos a profesorado universitario" (EA2010-0099). Programa estudios y análisis destinado a la mejora de la calidad de la enseñanza superior y de la actividad del profesorado universitario, Ministerio de Educación, Gobierno de España.González Soto, Á. P. & Sánchez Delgado, P. (2005). "¿Qué sabemos de cómo aprenden los alumnos en la universidad?". En Chamorro Plaza, M. & Sánchez Delgado, P. (Coords.) (2005): Iniciación a la docencia universitaria: Manual de ayuda. Instituto de Ciencias de la Educación. Madrid: Universidad Complutense de Madrid. 11-44.González, F. & Wagenaar, R. (2003). Tuning Educational Structures in Europe. Final Repport. Phase One. Bilbao: Universidad de Deusto.OCDE (2001). Definition and selection of competencies: Theoretical and Conceptual Foundations. DeSeCo Background Paper.Perrenoud, P. (2004). Diez nuevas competencias para enseñar. Barcelona: Graó.Real Decreto 1393/2007, de 29 de octubre, por el que se establece la ordenación de las enseñanzas universitarias oficiales (BOE 30-10-07).Rodríguez Espinar, S. (2003). "La formación del profesorado universitario."Revista de Educación, Ministerio de Educación, Cultura y Deporte de España, nº 331, Mayo- Agosto. 67-99. En Rué, J. (2007): Enseñar en la universidad: el EEES como reto para la educación superior. Madrid: Narcea.Rope, F. & Tanguy, L. (Dirs.) (1994). Savoirs et compétences. De l'usage de ces notions dans l'école et dans l'entreprise. L'Harmattan, col. «Logiques Sociales», París. Citado en: HORMS, O. (2009) La formación profesional en España. Hacia la sociedad del conocimiento. Colección Estudios Sociales nº 25, Edición electrónica disponible en: http://obrasocial.lacaixa.es/ambitos/estudiossociales/volumenes09_es.html#vol25. [Consultado el 14 de marzo de 2011].Simpson, R.D. & Smith, K.S. (1995). "Validacing teaching competencies for graduate teaching assistants: a national study using the Delphi Method." En Innovative High Education, nº 2, 18, 133-146.Valcárcel, M. (Coord.) (2009). Modelos Prácticos y eficientes de formación y evaluación de competencias transversales en estudiantes y profesores. (Memoria EA2009-0127). Disponible en http://82.223.210.121/mec/ayudas. [Consultado el 10 de enero de 2011]Zabalza, M.A. (2007). Planes de formación del profesorado universitario. Encuentro ANECA sobre La evaluación del profesorado dentro de los Sistemas de Garantía de Calidad de las Instituciones Universitarias. http://www.aneca.es/servicios/docs/burgos07_09_zabalza.pdf [Consultado el 10 de enero de 2011]Zarifian, P. (1999). Objectif compétence. Pour une nouvelle logique. París: Éditions Liaisons, col. Enterprise et carrières
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.
BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK
Background
A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials.
Methods
This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674.
Findings
Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation.
Interpretation
ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials
Barragán al Marroc: una identitat retrobada
Anys després dels seus dos primers viatges en què va quedar fascinat pels jardins de l'Alhambra i Ferdinand Bac primer, i posteriorment per l'arquitectura racionalista d'avantguarda, Luis Barragán va emprendre, a l'edat de cinquanta anys i en un moment de maduresa i revaloració del local, una tercera travessia per Europa que va finalitzar amb un recorregut d'un mes pel Marroc al gener de 1953. Coneixedor de les experiències al nord de l'Àfrica dels artistes Miguel Covarrubias i Mathias Goeritz, la decisió de viatjar per les terres de l'Atles va ser conseqüència del desig de visitar la seva arquitectura tradicional profundament lligada al paisatge en una inquietud comuna a altres arquitectes del segle XX que li van precedir en el viatge. L'arquitectura primitiva i sense arquitectes havia empès Gunnar Asplund i Le Corbusier primer, seguits després per Jorn Utzon, Alvar Aalto, Sverre Fehn i Luis Barragán, entre d’altres, a viatjar pel nord de l'Àfrica, en un renovat interès envers el paisatge i tradicions locals, formant part del que Kenneth Frampton va denominar Regionalisme Crític, caracteritzat per la relació entre lloc i cultura, costums i arquitectura. L'obra de Barragán va manifestar després d'aquella travessia transcendental i desconeguda un llenguatge espacial auster, abstracte, laberíntic i interior, síntesi de la memòria del seu Mèxic d'origen i del descobriment de la sorprenent terra de l'Atles: què va veure Luis Barragán per dir que el viatge al Marroc va ser el que més li va impressionar a la seva vida?Years after his first two journeys in which he was fascinated by the gardens of the Alhambra and Ferdinand Bac first, and later by avant-garde rationalist architecture, Luis Barragán set out -at the age of fifty and at a time of maturity and revaluation of the local- on a third tour of Europe that ended with a month-long trip to Morocco in January 1953. Familiar with the experiences in North Africa of the artists Miguel Covarrubias and Mathias Goeritz, the decision to travel through the Atlas lands was a consequence of the desire to visit its traditional architecture -deeply linked to the landscape- in a concern common to other twentieth-century architects who preceded him on his journey. Primitive architecture without architects had pushed Gunnar Asplund and Le Corbusier first, followed later by Jorn Utzon, Alvar Aalto, Sverre Fehn and Luis Barragán, among others, to travel through North Africa, in a renewed interest in the landscape and local traditions, becoming part of what Kenneth Frampton called Critical Regionalism, characterized by the relationship between place and culture, customs and architecture. After that transcendental and unknown journey, Barragán's work manifested an austere, abstract, labyrinthine, and interior spatial language, a synthesis of the memory of his native Mexico and the discovery of the astounding land of the Atlas: What did Luis Barragán see to say that the trip to Morocco was the one that made the greatest impression on him in his life?Años después de sus dos primeros viajes en los que quedó fascinado por los jardines de la Alhambra y Ferdinand Bac primero, y posteriormente por la arquitectura racionalista de vanguardia, Luis Barragán emprendió, a la edad de cincuenta años y en un momento de madurez y revalorización de lo local, una tercera travesía por Europa que finalizó con un recorrido de un mes por Marruecos en enero de 1953. Conocedor de las experiencias en el norte de África de los artistas Miguel Covarrubias y Mathias Goeritz, la decisión de viajar por las tierras del Atlas fue consecuencia del deseo de visitar su arquitectura tradicional profundamente ligada al paisaje en una inquietud común a otros arquitectos del siglo XX que le precedieron en el viaje. La arquitectura primitiva y sin arquitectos había empujado a Gunnar Asplund y Le Corbusier primero, seguidos después por Jørn Utzon, Alvar Aalto, Sverre Fehn y Luis Barragán, entre otros, a viajar por el norte de África, en un renovado interés hacia el paisaje y tradiciones locales, formando parte de lo que Kenneth Frampton denominó Regionalismo Crítico, caracterizado por la relación entre lugar y cultura, costumbres y arquitectura. La obra de Barragán manifestó después de aquella travesía trascendental y desconocida un lenguaje espacial austero, abstracto, laberíntico e interior, síntesis de la memoria de su México de origen y del descubrimiento de la asombrosa tierra del Atlas: ¿qué vio Luis Barragán para decir que el viaje a Marruecos fue el que más le impresionó en su vida?Peer Reviewe
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