3,199 research outputs found

    Uses of Native Plant Species of a Communal Rangeland within ‘Sierra de Huautla’ Protected Area, México

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    Sustainability of communal rangelands has become a major concern at national and international levels because land use conflicts and associated social conflicts allows for over-utilization of selected species making a high pressure on them and given away their places to species with no use at all becoming lands degraded and unproductive. The objective of the study was to determine floristic composition and native plant uses by local peasants. The range surface is of 4262 ha, belongs to the communal land ‘El Limon’, in Tepalcingo, Morelos, Mexico, and it is within the Natural Reserve Area “Sierra de Huautla”. Native vegetation is mainly of deciduous shrubs, high temperatures year round and a rainy season of 4 months. Local peasants were surveyed on uses of the collected and previously identified plants. Number of species was 456, distributed in 266 and 76 botanical genders and families, respectively. Of the species identified 66, 22 and 12% had one, two or more than two uses according to local peasants. Among uses: 59% of the species were used as forage, 8% eatable, 7% firewood or ornamental, 6% medical herb, lumber or other use 4 %, construction material 3 % and for resin or handcraft 1%. The range showed a very high plant biodiversity, this feature allows for a high resiliency toward human activities

    Mesoscopic model and free energy landscape for protein-DNA binding sites: Analysis of cyanobacterial promoters

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License.The identification of protein binding sites in promoter sequences is a key problem to understand and control regulation in biochemistry and biotechnological processes. We use a computational method to analyze promoters from a given genome. Our approach is based on a physical model at the mesoscopic level of protein-DNA interaction based on the influence of DNA local conformation on the dynamics of a general particle along the chain. Following the proposed model, the joined dynamics of the protein particle and the DNA portion of interest, only characterized by its base pair sequence, is simulated. The simulation output is analyzed by generating and analyzing the Free Energy Landscape of the system. In order to prove the capacity of prediction of our computational method we have analyzed nine promoters of Anabaena PCC 7120. We are able to identify the transcription starting site of each of the promoters as the most populated macrostate in the dynamics. The developed procedure allows also to characterize promoter macrostates in terms of thermo-statistical magnitudes (free energy and entropy), with valuable biological implications. Our results agree with independent previous experimental results. Thus, our methods appear as a powerful complementary tool for identifying protein binding sites in promoter sequences.This work was supported by the Spanish Goverment under DGICYT Projects No. FIS2011-25167, BFU2009-07424, BFU2012-31458 cofinanced by FEDER funds, Gobierno de Aragon (projects B18 and E19), “Proyecto Intramural” (BIFI) and Spanish government fellowship FPU-2012-2608 (RTR).Peer Reviewe

    Plasticity of Dendritic Spines. Not Only for Cognitive Processes

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    Excitatory synaptic transmission is associated with the input of “new” information at synaptic junctions established by dendritic spines. The role that each type of spine plays in the transmission of the synaptic impulses is different. Indeed, there is a close relationship between the shape of spines and the differential processing of the excitatory synaptic information that is relayed to them, influencing in turn the transmission of synaptic information related to several psychoneural processes

    Evaluación preliminar de la calidad de biofertilizante para <i>Bursera bipinnata</i>

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    La Bursera bipinnata se reproduce difícilmente en su medio natural, el constante ramoneo, pisoteo y cambios en su hábitat impiden que las plantas logren madurar para que puedan aprovecharse. Por esta situación, es necesario buscar alternativas que favorezcan la supervivencia del copal, una de ellas es mediante establecimiento de simbiosis con Hongos Micorrizógenos Arbusculares (HMA). Por lo anterior, el objetivo de este trabajo fue preparar un biofertilizante de HMA, con la finalidad evaluar de su calidad y disponer de una alternativa que favorezca el establecimiento de las plántulas de copal. La evaluación preliminar de la calidad del biofertizante se basó en el indicador “concentración de esporas” y se comparó con biofertilizantes comerciales. Los resultados indican que la calidad del biofertilizante para B. bipinnata es baja. Faltando aún por evaluar los siguientes indicadores de calidad: infectividad, efectividad e inocuidad del producto.The Bursera bipinnata hardly it reproduces in their natural environment, constant grazing, trampling and Changes in habitat and prevent the plants mature so they can achieve profit. For this situation, it is necessary to find alternatives that favor the survival of copal, one of them is by establishing symbiosis with Arbuscular mycorrhizal fungi (AMF). Therefore, the objective of this work was to prepare a biofertilizer of AMF, in order to assess their quality and have an alternative that promotes seedling establishment of copal. The preliminary assessment of the quality of biofertizante was based on the "concentration of spores" indicator and compared with commercial biofertilizers. The results indicate that the quality of biofertilizer to B. bipinnata is low. Still lacking to evaluate the following quality indicators: infectivity, effectiveness and safety of the product.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos).Facultad de Ciencias Agrarias y Forestale

    A young double stellar cluster in a HII region, emerging from its parent molecular cloud

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    We report the properties of a new young double stellar cluster in the region towards IRAS 07141-0920 contained in the HII region Sh2-294. High-resolution optical UBVRI and Halpha images, near-infrared JHKs and H2 filter images were used to make photometric and morphological studies of the point sources and the nebula seen towards Sh2-294. The optical images reveal an emission nebula with very rich morphological details, composed mainly of UV scattered light and of Halpha emission. Contrasting with the bright parts of the nebula, opaque, elongated patches are seen. Our optical photometry confirms that the illuminator of the nebula is likely to be a B0.5V star located at a distance of about 3.2 kpc. Our near-IR images reveal an embedded cluster, extending for about 2 pc and exhibiting sub-clustering: a denser, more condensed, sub-cluster surrounding the optical high-mass B0.5V illuminator star; and a more embedded, optically invisible, sub-cluster located towards the eastern, dark part of the nebula and including the luminous MSX source G224.1880+01.2407, a massive protostellar candidate that could be the origin of jets and extended features seen at 2.12 micron. The double cluster appears to be clearing the remaining molecular material of the parent cloud, creating patches of lower extinction and allowing some of the least reddened members to be detected in the optical images. We find 12 MS and 143 PMS members using 3 different methods: comparison with isochrones in optical colour-magnitude diagrams, detection of near-IR excess, and presence of Halpha emission. The most massive star fits a 4 Myr post-MS isochrone. The age of the optically selected PMS population is estimated to be 7-8 Myr. The IR-excess population shows sub-clustering on scales as small as 0.23 pc and is probably much younger.Comment: 15 pages, 16 figure

    Evaluación preliminar de la calidad de biofertilizante para <i>Bursera bipinnata</i>

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    La Bursera bipinnata se reproduce difícilmente en su medio natural, el constante ramoneo, pisoteo y cambios en su hábitat impiden que las plantas logren madurar para que puedan aprovecharse. Por esta situación, es necesario buscar alternativas que favorezcan la supervivencia del copal, una de ellas es mediante establecimiento de simbiosis con Hongos Micorrizógenos Arbusculares (HMA). Por lo anterior, el objetivo de este trabajo fue preparar un biofertilizante de HMA, con la finalidad evaluar de su calidad y disponer de una alternativa que favorezca el establecimiento de las plántulas de copal. La evaluación preliminar de la calidad del biofertizante se basó en el indicador “concentración de esporas” y se comparó con biofertilizantes comerciales. Los resultados indican que la calidad del biofertilizante para B. bipinnata es baja. Faltando aún por evaluar los siguientes indicadores de calidad: infectividad, efectividad e inocuidad del producto.The Bursera bipinnata hardly it reproduces in their natural environment, constant grazing, trampling and Changes in habitat and prevent the plants mature so they can achieve profit. For this situation, it is necessary to find alternatives that favor the survival of copal, one of them is by establishing symbiosis with Arbuscular mycorrhizal fungi (AMF). Therefore, the objective of this work was to prepare a biofertilizer of AMF, in order to assess their quality and have an alternative that promotes seedling establishment of copal. The preliminary assessment of the quality of biofertizante was based on the "concentration of spores" indicator and compared with commercial biofertilizers. The results indicate that the quality of biofertilizer to B. bipinnata is low. Still lacking to evaluate the following quality indicators: infectivity, effectiveness and safety of the product.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos).Facultad de Ciencias Agrarias y Forestale

    Triple-Negative Breast Cancer: A Review of Conventional and Advanced Therapeutic Strategies

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    Triple-negative breast cancer (TNBC) cells are deficient in estrogen, progesterone and ERBB2 receptor expression, presenting a particularly challenging therapeutic target due to their highly invasive nature and relatively low response to therapeutics. There is an absence of specific treatment strategies for this tumor subgroup, and hence TNBC is managed with conventional therapeutics, often leading to systemic relapse. In terms of histology and transcription profile these cancers have similarities to BRCA-1-linked breast cancers, and it is hypothesized that BRCA1 pathway is non-functional in this type of breast cancer. In this review article, we discuss the different receptors expressed by TNBC as well as the diversity of different signaling pathways targeted by TNBC therapeutics, for example, Notch, Hedgehog, Wnt/b-Catenin as well as TGF-beta signaling pathways. Additionally, many epidermal growth factor receptor (EGFR), poly (ADP-ribose) polymerase (PARP) and mammalian target of rapamycin (mTOR) inhibitors effectively inhibit the TNBCs, but they face challenges of either resistance to drugs or relapse. The resistance of TNBC to conventional therapeutic agents has helped in the advancement of advanced TNBC therapeutic approaches including hyperthermia, photodynamic therapy, as well as nanomedicine-based targeted therapeutics of drugs, miRNA, siRNA, and aptamers, which will also be discussed. Artificial intelligence is another tool that is presented to enhance the diagnosis of TNBC

    Performance Evaluation of HL-LHC Crab Cavity Prototypes in a CERN Vertical Test Cryostat

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    Three proof-of-principle compact crab cavity designs have been fabricated in bulk niobium and cold tested at their home labs, as a first validation step towards the High Luminosity LHC project. As a cross check, all three bare cavities have been retested at CERN, in order to cross check their performance, and cross-calibrate the CERN SRF cold test facilities. While achievable transverse deflecting voltage is the key performance indicator, secondary performance aspects derived from multiple cavity monitoring systems are also discussed. Temperature mapping profiles, quench detection, material properties, and trapped magnetic flux effects have been assessed, and the influence on performance discussed. The significant effort invested in developing expertise in preparation and testing of these crab cavities has already been fruitful for all partners, and more is to come within this ongoing program
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