149 research outputs found
Persistencia de los cambios provocados por los fuegos controlados en diferentes estructuras del bosque de caldén (Prosopis caldenia Burk.)
Fire may be reintroducted as prescribed burns for different purposes, mainly to remove accumulated fuels and the risk of intense fires or as a tool of range management in order to improve the forage offer. The objective of this study was to assess the vegetation response to burning 6 and 12 months after precribed fires in two different caldén woodlands: open woodland (BA) associated with torage species, and closed forest (BD) with a poor proportion of forage species a) in the community b) in the seed bank. The effect of prescribed burn in this study had less impact on the vegetation structure of both communities than expected, in terms of reduction of non palatable woody species and increasing of forage species abundance. The vegetation response is principally influenced by ils structural and floristic characteristics.La reintroducción del fuego en forma de quema prescriptas puede tener diferentes finalidades. El uso más frecuente es para la reducción de fitomasa altamente combustible, disminuyendo de esta manera los riesgos de propagación de incendio o como herramienta para mantener o aumentar la producción forrajera de las áreas. El objetivo del presente trabajo es evaluar la respuesta de la vegetación a la acción de la quema controlada en los 6 y 12 meses posteriores a la misma en dos variantes de la comunidad de bosque de caldén: bosque abierto (BA) con presencia de especies forrajeras y bosque denso (BD) con baja proporción de especies forrajeras a) en la vegetación b) en el banco de semillas de gramíneas. El efecto del fuego controlado observado en este trabajo para ambas comunidades no tuvo la magnitud de cambio estructural que se esperaba en lo que respecta a aumento de forrajeras y disminución de especies no forrajeras y leñosas. La respuesta de la vegetación estuvo principalmente condicionada por las características estructurales y florísticas de la comunidad
Biosimilar therapeutics—what do we need to consider?
Patents for the first generation of approved biopharmaceuticals have either expired or are about to expire. Thus the market is opening for generic versions, referred to as ‘biosimilars’ (European Union) or ‘follow-on protein products’ (United States). Healthcare professionals need to understand the critical issues surrounding the use of biosimilars to make informed treatment decisions
Detection of hepatitis viral E in clinical samples using real time methodology
El virus dela Hepatitis E (HEV) es trans-mitido a través de una ruta fecal-oral en áreas endémi-cas fundamentalmente por la ingesta de agua conta-minada y aunque la vía zoonótica está bien definida, la seroprevalencia en nuestra región debe aún ser esta-blecida. Este patógeno es de relevancia sanitaria fun-damentalmente entre las embarazadas, los trasplanta-dos y los pacientes inmunocomprometidos, por lo que desarrollar métodos diagnósticos rápidos, sensibles y específicos nos brinda la oportunidad de aplicar medi-das terapéuticas y preventivas apropiadas
Structure of the Reaction Center from Rhodopseudomonas sphaeroides R-26 and 2.4.1: Protein-Cofactor (Bacteriochlorophyll, Bacteriopheophytin and Carotenoid) Interactions
The three-dimensional structures of the cofactors and protein subunits of the reaction center (RC) from the carotenoidless mutant strain of Rhodobacter sphaeroides R-26 and the wild-type strain 2.4.1 have been determined by x-ray diffraction to resolutions of 2.8 Å and 3.0 Å with R values of 24% and 26%, respectively. The bacteriochlorophyll dimer (D), bacteriochlorophyll monomers (B), and bacteriopheophytin monomers (φ) form two branches, A and B, that are approximately related by a twofold symmetry axis. The cofactors are located in hydrophobic environments formed by the L and M subunits. Differences in the cofactor-protein interactions between the A and B cofactors, as well as between the corresponding cofactors of Rb, sphaeroides and Rhodopseudomonas viridis [Michel, H., Epp, O. & Deisenhofer, J. (1986) EMBO J. 3, 2445-2451], are delineated. The roles of several structural features in the preferential electron transfer along the A branch are discussed. Two bound detergent molecules of beta-octyl glucoside have been located near B_A and B_B. The environment of the carotenoid, C, that is present in RCs from Rb. sphaeroides 2.4.1 consists largely of aromatic residues of the M subunit. A role of B_B in the triplet energy transfer from D to C and the reason for the preferential ease of removal of B_B from the RC is proposed
Gestión de resultado de investigación en Instituciones de Educación Superior
"El presente libro se deriva del proyecto de investigación «La introducción de resultados de las investigaciones científicas "" tecnológicas en Instituciones de Educación Superior»: un análisis explicativo de sus alcances en la solución de problemas sociales, empresariales y académicos en tres instituciones de la ciudad de Medellín: Instituto Tecnológico Metropolitano, Politécnico Colombiano Jaime Isaza Cadavid y la Facultad de Ciencias Humanas y Sociales de la Universidad de Antioquia. Se propone como objetivo dar cuenta de los componentes necesarios a tener presente en la configuración de un modelo para la gestión de los resultados de la investigación en Ciencia, Tecnología e Innovación en las Instituciones de Educación Superior. Con este estudio se espera lograr una contribución a la gestión del conocimiento que dé cuenta de las posibles estrategias, para avanzar de la producción de la ciencia, la tecnología y la innovación, hacia la introducción, generalización y validación de sus resultados en los diversos contextos, donde se hacen necesarios para lograr metas coherentes con los procesos de construcción de una sociedad del conocimiento.""""This book is derived from the research project """"The introduction of results from scientific-technological research in Higher Education Institutions"""": a comprehensive analysis of their scope in the solution of social, business and academic problems in three institutions from Medellín: Instituto Tecnológico Metropolitano, Politécnico Colombiano Jaime Isaza Cadavid and the Faculty of Human and Social Sciences of the Universidad de Antioquia. The book aims at presenting the necessary components that must be present in the configuration of a model for the management of research results in Science, Technology and Innovation in Higher Education Institutions. This study is expected to be a contribution to knowledge management that presents the potential strategies for progress in the production of science, technology and innovation, aiming at the introduction, generalization and validation of the results in the various contexts in which they are needed to achieve goals consistent with the process of building a knowledge society.""
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Enhanced antitumor efficacy of cisplatin in combination with HemoHIM in tumor-bearing mice
<p>Abstract</p> <p>Background</p> <p>Although cisplatin is one of the most effective chemotherapeutic agents, cisplatin alone does not achieve a satisfactory therapeutic outcome. Also cisplatin accumulation shows toxicity to normal tissues. In this study, we examined the possibility of HemoHIM both to enhance anticancer effect with cisplatin and to reduce the side effects of cisplatin in melanoma-bearing mice.</p> <p>Methods</p> <p>HemoHIM was prepared by adding the ethanol-insoluble fraction to the total water extract of a mixture of 3 edible herbs, Angelica Radix, Cnidium Rhizoma and Paeonia Radix. Anticancer effects of HemoHIM with cisplatin were evaluated in melanoma-bearing mice. We used a Cr<sup>51</sup>-release assay to measure the activity of NK/Tc cell and ELISA to evaluate the production of cytokines.</p> <p>Results</p> <p>In melanoma-bearing mice, cisplatin (4 mg/kg B.W.) reduced the size and weight of the solid tumors, and HemoHIM supplementation with cisplatin enhanced the decrease of both the tumor size (p < 0.1) and weight (p < 0.1). HemoHIM itself did not inhibit melanoma cell growth <it>in vitro</it>, and did not disturb the effects of cisplatin <it>in vitro</it>. However HemoHIM administration enhanced both NK cell and Tc cell activity in mice. Interestingly, HemoHIM increased the proportion of NK cells in the spleen. In melanoma-bearing mice treated with cisplatin, HemoHIM administration also increased the activity of NK cells and Tc cells and the IL-2 and IFN-γ secretion from splenocytes, which seemed to contribute to the enhanced efficacy of cisplatin by HemoHIM. Also, HemoHIM reduced nephrotoxicity as seen by tubular cell of kidney destruction.</p> <p>Conclusion</p> <p>HemoHIM may be a beneficial supplement during cisplatin chemotherapy for enhancing the anti-tumor efficacy and reducing the toxicity of cisplatin.</p
S-allylmercaptocysteine scavenges hydroxyl radical and singlet oxygen in vitro and attenuates gentamicin-induced oxidative and nitrosative stress and renal damage in vivo
BACKGROUND: Oxidative and nitrosative stress have been involved in gentamicin-induced nephrotoxicity. The purpose of this work was to study the effect of S-allylmercaptocysteine, a garlic derived compound, on gentamicin-induced oxidative and nitrosative stress and nephrotoxicity. In addition, the in vitro reactive oxygen species scavenging properties of S-allylmercaptocysteine were studied. RESULTS: S-allylmercaptocysteine was able to scavenge hydroxyl radicals and singlet oxygen in vitro. In rats treated with gentamicin (70 mg/Kg body weight, subcutaneously, every 12 h, for 4 days), renal oxidative stress was made evident by the increase in protein carbonyl content and 4-hydroxy-2-nonenal, and the nitrosative stress was made evident by the increase in 3-nitrotyrosine. In addition, gentamicin-induced nephrotoxicity was evident by the: (1) decrease in creatinine clearance and in activity of circulating glutathione peroxidase, and (2) increase in urinary excretion of N-acetyl-β-D-glucosaminidase, and (3) necrosis of proximal tubular cells. Gentamicin-induced oxidative and nitrosative stress and nephrotoxicity were attenuated by S-allylmercaptocysteine treatment (100 mg/Kg body weight, intragastrically, 24 h before the first dose of gentamicin and 50 mg/Kg body weight, intragastrically, every 12 h, for 4 days along gentamicin-treatment). CONCLUSION: In conclusion, S-allylmercaptocysteine is able to scavenge hydroxyl radicals and singlet oxygen in vitro and to ameliorate the gentamicin-induced nephrotoxicity and oxidative and nitrosative stress in vivo
Hardwood seedling establishment below Aleppo pine depends on thinning intensity in two Mediterranean sites
Influence de l’hydromorphie sur la variabilité des stocks de carbone à l’échelle de versants dans une hêtraie (forêt de Fougères — Ouest de la France)
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