3,338 research outputs found

    Comunicar ciencia en México: Tendencias y narrativas

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    Para que sea útil, el conocimiento debe fluir desde las aulas, los laboratorios o la mente de los investigadores y creadores hacia el público en general y al especializado. Tarea primordial de la comunicación de la ciencia es tender los puentes que generen los diálogos y una retroalimentación enriquecedora entre ambos polos, y construir así una cultura que incorpore de una manera crítica y efectiva el conocimiento científico a la práctica cotidiana y al quehacer colectivo en aras de un desarrollo más armónico de la sociedad y con el entorno. Bajo esta perspectiva, en esta obra se presentan diversos trabajos que muestran desde las tendencias de la investigación académica internacional en la comunicación pública de la ciencia hasta la utilización de los periódicos, la televisión, los blogs u otros medios para vincular a los científicos y el público, y trasformar las relaciones entre ellos en beneficio común, ya sea a través del análisis y difusión de problemas médicos, como el Sida, o socioambientales, como la contaminación del agua, hasta el utilizar los principios del branding (construcción de marca) para una mejor difusión del conocimiento científico. Una obra de interés para todas aquellas personas involucradas en la generación y divulgación de la ciencia y la tecnología.ITESO, A.C

    Variación espacial y temporal del índice gonadal de Diadema antillarum (Echinodermata: Echinoidea) en las Islas Canarias

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    Diadema antillarum Philippi occurs in high density populations in the Canary Islands, creating extensive barren areas. During one year we determined seasonal changes in the algal abundance and population densities, test diameter, gut contents and gonad index of sea urchins in two localities (Abades and Boca Cangrejo). Boca Cangrejo shows higher algae cover and species richness than Abades. The sea urchin population at Abades had a higher density and smaller urchins than Boca Cangrejo. Boca Cangrejo sea urchins showed higher specific richness in gut contents than Abades urchins. The sea urchin population at Abades did not have a clearer reproductive periodicity or higher gonad index than the Boca Cangrejo population. Temporal and spatial changes in gonad periodicity of Diadema antillarum are attributed, at least in part, to benthic food availability (algal cover and algal species number) and intra-specific competition.Diadema antillarum Philippi presenta unas densidades altísimas en las islas Canarias, eliminando casi por completo la cubierta vegetal de los fondos rocosos litorales. Durante un año, hemos muestreado estacionalmente los cambios en la abundancia de algas y las densidades poblacionales, diámetros de caparazón, contenidos intestinales e índice gonadal de los erizos en dos localidades (Abades y Boca Cangrejo). Boca Cangrejo presenta mayores coberturas y riqueza algal que Abades. La población de erizos en Abades es más densa y esta formada por erizos de menor tamaño que en Boca Cangrejo. La riqueza algal en los contenidos estomacales es mayor en los erizos de Boca Cangrejo que la de los de Abades. Los erizos de Boca Cangrejo presentan una clara periodicidad reproductiva e índices gonadales superiores a los erizos de Abades. Las variaciones espaciales y estacionales en la periodicidad gonadal de Diadema antillarum pueden ser atribuidas, al menos en parte, a la disponibilidad bentónica de alimento (recubrimiento y número de especies de algas) y a la competencia intraespecífica.

    Progastrin Represses the Alternative Activation of Human Macrophages and Modulates Their Influence on Colon Cancer Epithelial Cells

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    Macrophage infiltration is a negative prognostic factor for most cancers but gastrointestinal tumors seem to be an exception. The effect of macrophages on cancer progression depends on their phenotype, which may vary between M1 (pro-inflammatory, defensive) to M2 (tolerogenic, pro-tumoral). Gastrointestinal cancers often become an ectopic source of gastrins and macrophages present receptors for these peptides. The aim of the present study is to analyze whether gastrins can affect the pattern of macrophage infiltration in colorectal tumors. We have evaluated the relationship between gastrin expression and the pattern of macrophage infiltration in samples from colorectal cancer and the influence of these peptides on the phenotype of macrophages differentiated from human peripheral monocytes in vitro. The total number of macrophages (CD68+ cells) was similar in tumoral and normal surrounding tissue, but the number of M2 macrophages (CD206+ cells) was significantly higher in the tumor. However, the number of these tumor-associated M2 macrophages correlated negatively with the immunoreactivity for gastrin peptides in tumor epithelial cells. Macrophages differentiated from human peripheral monocytes in the presence of progastrin showed lower levels of M2-markers (CD206, IL10) with normal amounts of M1-markers (CD86, IL12). Progastrin induced similar effects in mature macrophages treated with IL4 to obtain a M2-phenotype or with LPS plus IFNγ to generate M1-macrophages. Macrophages differentiated in the presence of progastrin presented a reduced expression of Wnt ligands and decreased the number and increased cell death of co-cultured colorectal cancer epithelial cells. Our results suggest that progastrin inhibits the acquisition of a M2-phenotype in human macrophages. This effect exerted on tumor associated macrophages may modulate cancer progression and should be taken into account when analyzing the therapeutic value of gastrin immunoneutralization

    Novel swirl flow-focusing microfluidic device for the production of monodisperse microbubbles

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    A novel swirl flow-focusing microfluidic axisymmetric device for the generation of monodisperse microbubbles at high production rates to be used as in-line contrast agents for medical applications is presented. The swirl effect is induced upstream of the discharge orifice by a circular array of microblades which form a given angle with the radial direction. The induced vortical component on the focusing liquid stabilizes the gas meniscus by the vorticity amplification due to vortex stretching as the liquid is forced through the discharge orifice. The stabilized meniscus tapers into a steady gas ligament that breaks into monodisperse microbubbles. A reduction up to 57% in the microbubble diameter is accomplished when compared to conventional axisymmetric flow-focusing microdevices. An exhaustive experimental study is performed for various blade angles and numerous gas to liquid flow rate ratios, validating previous VoF numerical simulations. The microbubbles issued from the stabilized menisci verify prior scaling law of flow-focusing

    Polymorphisms in DNA-repair genes in a cohort of prostate cancer patients from different areas in Spain: heterogeneity between populations as a confounding factor in association studies

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    Background: Differences in the distribution of genotypes between individuals of the same ethnicity are an important confounder factor commonly undervalued in typical association studies conducted in radiogenomics. Objective: To evaluate the genotypic distribution of SNPs in a wide set of Spanish prostate cancer patients for determine the homogeneity of the population and to disclose potential bias. Design, Setting, and Participants: A total of 601 prostate cancer patients from Andalusia, Basque Country, Canary and Catalonia were genotyped for 10 SNPs located in 6 different genes associated to DNA repair: XRCC1 (rs25487, rs25489, rs1799782), ERCC2 (rs13181), ERCC1 (rs11615), LIG4 (rs1805388, rs1805386), ATM (rs17503908, rs1800057) and P53 (rs1042522). The SNP genotyping was made in a Biotrove OpenArrayH NT Cycler. Outcome Measurements and Statistical Analysis: Comparisons of genotypic and allelic frequencies among populations, as well as haplotype analyses were determined using the web-based environment SNPator. Principal component analysis was made using the SnpMatrix and XSnpMatrix classes and methods implemented as an R package. Non-supervised hierarchical cluster of SNP was made using MultiExperiment Viewer. Results and Limitations: We observed that genotype distribution of 4 out 10 SNPs was statistically different among the studied populations, showing the greatest differences between Andalusia and Catalonia. These observations were confirmed in cluster analysis, principal component analysis and in the differential distribution of haplotypes among the populations. Because tumor characteristics have not been taken into account, it is possible that some polymorphisms may influence tumor characteristics in the same way that it may pose a risk factor for other disease characteristics. Conclusion: Differences in distribution of genotypes within different populations of the same ethnicity could be an important confounding factor responsible for the lack of validation of SNPs associated with radiation-induced toxicity, especially when extensive meta-analysis with subjects from different countries are carried out

    Compositional mapping by Z-contrast imaging

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    This research was sponsored by the Office of Basic Energy Sciences, Materials Sciences and Engineering Division, U.S. Department of Energy (SJP, MV), by the Spanish MCI (projects CONSOLIDER INGENIO 2010 CSD2009-00013 andTEC2008-06756-C03-02/TEC,) and the Junta de Andalucía (PAI research’s groups TEP-120 and TIC-145; project P08-TEP-03516).Peer Reviewe

    La experimentación del ECTS en trabajo social: la experiencia desde la Universidad de La Laguna

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    La experimentación del ECTS en trabajo social: la experiencia desde la Universidad de La Lagun

    Characterization of source rocks and groundwater radioactivity at the Chihuahua valley

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    As part of a scientific research project about alpha radioactivity in groundwater for human consumption at the Chihuahua City, the charac-terization of rock sources of radioactivity around de Chihuahua valley was developed. The radioactivity of groundwater and sediments wasdetermined, too. The radioactivity of uranium- and thorium- series isotopes contained in rocks was obtained by high resolution gamma-rayspectroscopy. Some representative values are 50 Bq/kg for the mean value of Bi-214 activity, and 121.5 Bq/kg for the highest value at Westof the city. The activity of sediments, extracted during wells perforation, was determined using a NaI(Tl) detector. A non-reported beforeuranium ore was localized at the San Marcos range formation. Its outcrops are inside the Chihuahua-Sacramento valley basin and its activ-ity characterization was performed. Unusually high specific uranium activities, determined by alpha spectrometry, were obtained in water,plants, sediments and fish extracted at locations close to outcrops of uranium minerals. The activity of water of the San Marcos dam reached7.7 Bq/L. The activity of fish, trapped at San Marcos dam, is 0.99 Bq/kg. Conclusions about the contamination of groundwater at North ofChihuahua City were obtained.Como parte de un proyecto cient ́ıfico sobre actividad alfa en agua subterr ́anea de consumo humano en la ciudad de Chihuahua, se hadesarrollado la caracterizaci ́on de las rocas fuentes de la radiactividad en el valle de Chihuahua. Se determin ́o tambi ́en la actividad de muestrasde agua subterr ́anea y de sedimentos. La actividad de los is ́otopos de las series radiactivas en las rocas se obtuvo usando espectroscop ́ıagamma de alta resoluci ́on. Algunos valores representativos son 50 Bq/kg para el valor medio de la actividad del Bi-214 y 121.5 Bq/kg para elvalor m ́as alto al oeste de la ciudad. La actividad de los sedimentos extra ́ıdos durante la perforaci ́on de pozos para agua potable, se determin ́ousando un detector de NaI(Tl). En la formaci ́on monta ̃nosa de San Marcos se localiz ́o un dep ́osito de uranio no publicado. Sus afloramientosse encuentran dentro de la cuenca del valle Chihuahua-Sacramento y se realiz ́o la caracterizaci ́on de su radiactividad. Se determinaronactividades por espectrometr ́ıa alfa de agua, plantas, sedimentos y peces extra ́ıdos en emplazamientos cercanos a los afloramientos deminerales de uranio. La actividad del agua en la presa de san Marcos lleg ́o a 7.7 Bq/L. La actividad de pescados de la misma presa alcanza0.99 Bq/kg. Se obtuvieron conclusiones sobre la contaminaci ́on del agua subterr ́anea al norte de la ciudad de Chihuahua
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