1,049 research outputs found
Hyperthermophily and the origin and earliest evolution of life
The possibility of a high-temperature origin of life has gained support based on indirect evidence of a hot, early Earth and on the basal position of hyperthermophilic organisms in rRNA-based phylogenies. However, although the availability of more than 80 completely sequenced cellular genomes has led to the identification of hyperthermophilic-specific traits, such as a trend towards smaller genomes, reduced proteinencoding gene sizes, and glutamic-acid-rich simple sequences, none of these characteristics are in themselves an indication of primitiveness. There is no geological evidence for the physical setting in which life arose, but current models suggest that the Earth’s surface cooled down rapidly. Moreover, at 100°C the half-lives of several organic compounds, including ribose, nucleobases, and amino acids, which are generally thought to have been essential for the emergence of the first living systems, are too short to allow for their accumulation in the prebiotic environment. Accordingly, if hyperthermophily is not truly primordial, then heat-loving lifestyles may be relics of a secondary adaptation that evolved after the origin of life, and before or soon after separation of the major lineages
La agricultura periurbana multifuncional y sus aportaciones hacia la sustentabilidad regional en la Zona Metropolitana de Guadalajara, Jalisco, México
Un modelo de desarrollo basado en relaciones asimétricas y desequilibradas entre la ciudad y el campo, y entre la sociedad y sus ecosistemas, ha dado como resultado que en la Zona Metropolitana de Guadalajara (ZMG), en Jalisco, México, se generen conflictos ambientales en un entorno de creciente insustentabilidad regional. Algunas expresiones de esta situación se manifiestan en las áreas periurbanas y rurales con el avance descontrolado de la urbanización, la disminución de la superficie agropecuaria, la pérdida de vegetación y agrodiversidad, la deforestación, el agotamiento de los suelos, la disminución y contaminación del agua, la sanidad de los alimentos, las afectaciones a la salud pública y el deterioro del nivel de vida de sus habitantes. La importancia poblacional, económica y política de esta región y el aumento de los conflictos ambientales, demandan a los actores sociales e institucionales, la construcción de alternativas hacia la sustentabilidad regional, y en ellas juegan un papel fundamental la múltiples funciones que desempeña la agricultura periurbana o agricultura de proximidad.
En este capítulo se presentan reflexiones y avances del proyecto de investigación e intervención “Agua, agrodiversidad y medio ambiente en la región Guadalajara-Chapala-Santiago” que a partir de una perspectiva de complejidad, ubicada en las ciencias de la sustentabilidad, ha realizado investigación interdisciplinaria en torno a tres procesos relevantes que generan conflictos ambientales en la región: a) uso y manejo del agua, b) relaciones ciudad campo, y c) gestión pública y social. El trabajo de intervención se ha orientado a la vinculación entre grupos y redes, a la formación campesino a campesino, al dialogo de saberes y al impulso de procesos sociales y organizativos, como parte del acompañamiento universitario a los actores locales en la construcción y fortalecimiento de sus alternativas hacia la sustentabilidad regional.ITESO, A.C
Paper Session II-D - Project Vision (Very Intensive Scientific Intercurricular Onsite Education): A Partnership Among NASA/John F. Kennedy Space Center, Florida International University, Universidad del Turabo, Dade County Public Schools, and the Caguas/Gurabo Public Schools.
Project VISION is a joint effort among NASA/John F. Kennedy Space Center, Florida International University, Universidad del Turabo, Dade County Public Schools and the Caguas/ Gurabo Public Schools. The project’s main mission is to institutionalize change among the 7th grade science and mathematics teachers at participating public middle schools. A further aspect of the mission is to enhance the science and math education of the public middle school students during the phase of institutionalization. Project VISION will not need to generate any new educational materials to fulfill its mission. Rather than generating new materials, Project VISION will use the vast quantities of high quality learning modules, lessons, hands-on experiments and other educational materials available at NASA and other scientific depositories. The project will identify, adopt and then adapt these learning modules or learning materials to best meet the needs and capabilities of the target student and teacher populations. A further goal of this project lies within the realm of NASA’s Mission - to specifically focus our activities on middle schools that serve socially and economically disadvantaged students. Additionally, the project will invite members of the private and public sectors to serve as lecturers, mentors and role models. The project will perform program evaluations to measure the levels of success and accomplishments of each of the proposed activities
Contribución al conocimiento de la flora de Andalucía: citas novedosas e interesantes de la provincia de Almería
Contribution to the knowledge about Andalusian flora: new and interesting cites of the Almería province.Palabras clave. Corología, Isla de Alborán, sureste ibérico, xenófitas.Key words. Corology, Alborán Island, South-Eastern Iberian Peninsula, xenophytes
Biochemical and structural characterization of a novel thermophilic esterase EstD11 provide catalytic insights for the HSL family
[Abstract]: A novel esterase, EstD11, has been discovered in a hot spring metagenomic library. It is a thermophilic and thermostable esterase with an optimum temperature of 60 C. A detailed substrate preference analysis of EstD11 was done using a library of chromogenic ester substrate that revealed the broad substrate specificity of EstD11 with significant measurable activity against 16 substrates with varied chain length, steric hindrance, aromaticity and flexibility of the linker between the carboxyl and the alcohol moiety of the ester. The tridimensional structures of EstD11 and the inactive mutant have been determined at atomic resolutions. Structural and bioinformatic analysis, confirm that EstD11 belongs to the family IV, the hormone-sensitive lipase (HSL) family, from the α/β-hydrolase superfamily. The canonical a/b hydrolase domain is completed by a cap domain, composed by two subdomains that can unmask of the active site to allow the substrate to enter. Eight crystallographic complexes were solved with different substrates and reaction products that allowed identification of the hot-spots in the active site underlying the specificity of the protein. Crystallization and/or incubation of EstD11 at high temperature provided unique information on cap dynamics and a first glimpse of enzymatic activity in vivo. Very interestingly, we have discovered a unique Met zipper lining the active site and the cap domains that could be essential in pivotal aspects as thermo-stability and substrate promiscuity in EstD11Ministerio de Ciencia e Innovación; BFU2017-90030-
A Educación Global na Educación Secundaria Obligatoria: unha investigación diagnóstica nos centros educativos de Galicia
The collaborative research project "Exploring the possibilities of extending the global dimension of Education for Development in the ESO. Diagnostic investigation in the schools" is conducted between the GI "Education Policy, History and Society" of the UDC and Solidariedade International of Galician, funded by the Xunta de Galicia. The aim is to identify the needs of teachers and the school for mainstreaming Global Education in the curriculum. We started from the experience of UK, experts and Galician teachers to provide descriptions and resources for teachers to integrate this dimension in the classroom.O Proxecto de Investigación “Explorando as posibilidades de estender a dimensión global da educación para o desenvolvemento na ESO. Unha investigación diagnóstica en centros educativos” é unha proposta de investigación colaborativa entre o Grupo de Investigación Política Educativa, Historia e Sociedade da Universidade da Coruña e Solidariedade Internacional de Galicia, financiado pola Xunta de Galicia (PR804A 2014/07). O obxectivo é identificar as necesidades do profesorado e do centro educativo que colabora nos proxectos de Educación para o Desenvolvemento (EpD) de ONGDs para que estas accións sexan máis significativas para o alumnado. Tomamos como referencia a experiencia do Reino Unido. Trátase dunha investigación cualitativa para o quese aplicaron distintas estratexias de recollida de datos arredor de tres obxectivos: (i) saber como integraron no Reino Unido a dimensión global no curriculum e cales son as súas porpostas didácticas, (ii) coñecer outras experiencias , e (iii) desvelar cales son os intereses e necesidades do profesorado galego para integrar a dimensión global. Para abordar estos obxectivos utilizáronse técnicas que permitisen comprender as experiencias sociais nos escenarios naturais desde a perspectiva dos protagonistas, en concreto: 1. Análise de documentos para caracterizar a dimensión global no curriculo e nas propostas didácticas do Reino Unido, estructurando en unidades de significado as distintas fontes documentais a través de categorías. 2. Microestudos de caso en 6 centros educativos para coñecer os intereses e necesidades do profesorado individualmente e do centro no seu conxunto, mediante entrevistas –de corte narrativo e semiestructuradas– a tres tipos de informantes (membros do equipo directivo, responsables das bibliotecas e profesorado que xa desenvolve actividades de EpD nas aulas). 3. Os grupos focais para contrastar as distintas realidades dos centros educativos e contrastar posicionamentos de forma simultánea. 4. Entrevistas semiestructuradas a persoas expertas en Educación Global e 5. Elaboración de forma colaborativa dunha plataforma. Como estratexia xeral de análise aplicouse a codificación temática. A meta do estudo é proporcionar descripcións e interpretacións, e non xeralizacións, que permitan a outros docentes aplicar algunhas das conclusións e recomendacións a súa experiencia nas aulas. Con esta finalidade creouse unha plataforma dixital para facilitar o acceso a bibliografía, compartir experieincias e fomentar o intercambio
Plasma-Derived Extracellular Vesicles as Potential Biomarkers in Heart Transplant Patient with Chronic Chagas Disease
Chagas disease is emerging in countries to which it is not endemic. Biomarkers for earlier therapeutic response assessment in patients with chronic Chagas disease are needed. We profiled plasma-derived extracellular vesicles from a heart transplant patient with chronic Chagas disease and showed the potential of this approach for discovering such biomarkers
Sustainable strategies for management of the “false root-knot nematode” Nacobbus spp.
The genus Nacobbus, known as the false root-knot nematode, is native to the American continent and comprises polyphagous species adapted to a wide range of climatic conditions. Alone or in combination with other biotic and abiotic factors, Nacobbus spp. can cause significant economic yield losses on main food crops such as potato, sugar beet, tomato, pepper and bean, in South and North America. Although the genus distribution is restricted to the American continent, it has quarantine importance and is subject to international legislation to prevent its spread to other regions, such as the European Union. The management of Nacobbus spp. remains unsatisfactory due to the lack of information related to different aspects of its life cycle, survival stages in the soil and in plant material, a rapid and reliable diagnostic method for its detection and the insufficient source of resistant plant genotypes. Due to the high toxicity of chemical nematicides, the search for alternatives has been intensified. Therefore, this review reports findings on the application of environmentally benign treatments to manage Nacobbus spp. Biological control strategies, such as the use of different organisms (mainly bacteria, fungi and entomopathogenic nematodes) and other eco-compatible approaches (such as metabolites, essential oils, plant extracts, phytohormones and amendments), either alone or as part of a combined control strategy, are discussed. Knowledge of potential sources of resistance for genetic improvement for crops susceptible to Nacobbus spp. are also reported. The sustainable strategies outlined here offer immediate benefits, not only to counter the pathogen, but also as good alternatives to improve crop health and growth
What can we learn from GRBs?
We review our recent results on the classification of long and short gamma-ray bursts (GRBs) in different subclasses. We provide observational evidences for the binary nature of GRB progenitors. For long bursts the induced gravitational collapse (IGC) paradigm proposes as progenitor a tight binary system composed of a carbon-oxygen core (COcore) and a neutron star (NS) companion; the supernova (SN) explosion of the COcore triggers a hypercritical accretion process onto the companion NS. For short bursts a NS–NS merger is traditionally adopted as the progenitor. We also indicate additional sub-classes originating from different progenitors: (COcore)–black hole (BH), BH–NS, and white dwarf–NS binaries. We also show how the outcomes of the further evolution of some of these sub-classes may become the progenitor systems of other sub-classes
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