Functional organization of the gene cluster involved in the synthesis of the pneumococcal capsule

Streptococcus pneumoniae is a major human pathogen and its capsular polysaccharide has been shown to be the main virulence factor. The molecular organization of the genes governing the formation of this capsule was not studied until the 1990s. The capsular clusters (cap) of eight of the 90 known pneumococcal types have now been studied. The cap operon, located between the dexB and aliA genes, is arranged as a central region comprising the genes coding for the specifictype polysaccharide, flanked by open reading frames that are mostly common to all of the serotypes. The biochemical functions of 24 genes required for capsular polysaccharide biosynthesis have been elucidated but the precise role of the flanking regions in capsular formation is unknown. The natural genetic transformation characteristic of pneumococci, the arrangement of the cap locus and the abundance of transposable elements at this locus favor the genetic variability of the capsule in this microorganism. These well-documented observations together with the finding that some genes located outside the cap cluster may also participate in capsule formation increase the complexity of pneumococcal infection control

Evaluación y calidad en los programas y cursos online en la enseñanza superior

Distance Education has been always considered with certain skepticism for the quality of the programs in contrast with the education in presence. The distance education based on virtual networks has managed to diminish the mistrust, but it has not made it disappear. The evaluation, as critical aspect of the quality, up to today has not been an object of a deep examination in relation to the new contexts, which implies that the conventionaland proper systems of evaluation of the formation in presence are applied to the environments online. Nevertheless, there exists a widespread intuition in which such systems do not correspond completely to the nature of the education and of learningin virtual communities, Aspect that has been particularly sensitive in case of the Project Alfa-Miforcal, illustrated with a pair of examples. The scenario of the education online is changing dramatically with the emergence of new ways of teaching and of learning, going on from models of reproduction of knowledge to models of collaborative learning and shared knowledge focused on the activity of the student in Learning Virtual Communities. In these, it is possible to come to a grade of interaction in which theformative evaluation reaches similar levels to those of the best orientation of learning in presence.La Educación a Distancia (EAD) ha sido siempre considerada con cierto escepticismo en cuanto a la calidad de los programas en contraste con la enseñanza en presencia. La EAD basada en redes telemáticas ha logrado disminuir el recelo, pero no lo ha hecho desaparecer. La evaluación, como aspecto crítico de la calidad, hasta hoy no ha sido objeto de un examen profundo en relación a los nuevos contextos y en general se trasvasan los sistemas de evaluación convencionales y propios de la formación en presencia a los entornos online. Sin embargo, existe una intuición extendida en que tales sistemas no son del todo congruentes con la naturaleza de la enseñanza y del aprendizaje en comunidades virtuales, aspecto que ha sido particularmente sensible en el caso del Proyecto Alfa-Miforcal, ilustrándose con un par de ejemplos. El escenario de la educación online está cambiando dramáticamente con el surgimiento de nuevas formas de enseñar y aprender,pasando de modelos de reproducción de conocimientos a modelos del aprendizaje colaborativo y conocimiento compartido centrados en la actividad del estudiante en Comunidades Virtuales de Aprendizaje. En estas se puede llegar a un grado de interacciónen el que la evaluación formativa alcanza niveles semejantes a los de la mejor orientación del aprendizaje en presencia

Polarised light sheet tomography

The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no. 608133 and Scottish Funding Council (SFC) Horizon fund.The various benefits of light sheet microscopy have made it a widely used modality for capturing three- dimensional images. It is mostly used for fluorescence imaging, but recently another technique called Light Sheet Tomography solely relying on scattering was presented. The method was successfully applied to imaging of plant roots in transparent soil, but is limited when it comes to more turbid samples. This study presents a Polarised Light Sheet Tomography system and its advantages when imaging in highly scattering turbid media. The experimental configuration is guided by Monte Carlo Radiation Transfer methods, which model the propagation of a polarised light sheet in the sample. Images of both reflecting and absorbing phantoms in a complex collagenous matrix were acquired, and the results for different polarisation configurations are compared. Focus scanning methods were then used to reduce noise and produce three-dimensional reconstructions of absorbing targets.PostprintPeer reviewe

Multi-platform experiments, numerical simulations and data science techniques for generation of new altimetric products: focus on mesoscale and sub- mesoscale variability (MANATEE – OSTST proposal)

Trabajo presentado en la Ocean Surface Topography Science Team Meeting (OSTST), celebrada online del 19 al 23 de octubre de 2020

PpiA, a Surface PPIase of the Cyclophilin Family in Lactococcus lactis

Background: Protein folding in the envelope is a crucial limiting step of protein export and secretion. In order to better understand this process in Lactococcus lactis, a lactic acid bacterium, genes encoding putative exported folding factors like Peptidyl Prolyl Isomerases (PPIases) were searched for in lactococcal genomes. Results: In L. lactis, a new putative membrane PPIase of the cyclophilin subfamily, PpiA, was identified and characterized. ppiA gene was found to be constitutively expressed under normal and stress (heat shock, H2O2) conditions. Under normal conditions, PpiA protein was synthesized and released from intact cells by an exogenously added protease, showing that it was exposed at the cell surface. No obvious phenotype could be associated to a ppiA mutant strain under several laboratory conditions including stress conditions, except a very low sensitivity to H2O2. Induction of a ppiA copy provided in trans had no effect i) on the thermosensitivity of an mutant strain deficient for the lactococcal surface protease HtrA and ii) on the secretion and stability on four exported proteins (a highly degraded hybrid protein and three heterologous secreted proteins) in an otherwise wild-type strain background. However, a recombinant soluble form of PpiA that had been produced and secreted in L. lactis and purified from a culture supernatant displayed both PPIase and chaperone activities. Conclusions: Although L. lactis PpiA, a protein produced and exposed at the cell surface under normal conditions, displaye

Cruise Plan: Fine-Scale ocean currents from integrated multi-platform experiments and numerical simulations: contribution to the new SWOT satellite mission (FaSt-SWOT, PID2021-122417NB-I00)

The FaSt-SWOT project is funded by the Spanish Research Agency and the European Regional Development Fund (AEI/FEDER, UE) under Grant Agreement (PID2021-122417NB-I00). The present research is conducted within the framework of the activities of the Spanish Government through the "María de Maeztu Centre of Excellence'' accreditation to IMEDEA (CSIC-UIB) (CEX2021-001198). The Spanish Ministry of Science and Innovation, the Regional Government of the Balearic Islands and the Spanish Research Council (CSIC) are acknowledged for their support to the ICTS SOCIB. A. P., B. M. and B. B. L. thank the European Union funding through the EuroSea project an Horizon 2020 research and innovation programme under grant agreement No 862626.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001198).Peer reviewe

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion