7,736 research outputs found

    The Whooping Crane in Mexico: Past, Present, and Future?

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    We reviewed ornithological, historic, anthropological, and archaeological records for evidence of whooping cranes (Grus americana) in Mexico. Records of whooping cranes in Mexico span 88 years (1863-1951) and cluster in 3 areas. Wintering records come from the northern highlands (Durango, and possibly Chihuahua), the central highlands (Guanajuato, Jalisco), and northeastern Tamaulipas, where the bird was also found in summer and might have bred. Later records (1970’s and 1980’s) of whooping cranes in the northern highlands are from individual birds released into the experimental migratory population that formerly migrated from Idaho to New Mexico, USA. Many of the wetlands used by whooping cranes remain and, though faced with a variety of threats, are conservation priority areas and some are already protected. We suggest 3 scenarios by which whooping cranes might return to winter in Mexico. The first 2 involve dispersal by birds wintering at the Aransas National Wildlife Refuge, Texas, USA, by either population growth or ecosystem changes or degradation (e.g., climate change, reduced freshwater inflows) at the refuge. Finally, reintroduction of a migratory population might target part of Mexico as a wintering area. We encourage investigation of wetlands in Mexico, especially in northeastern Tamaulipas for their potential as future wintering areas. Our preliminary survey of historic Spanish language publications covering the 1500’s to early 1600’s found clear references to cranes in which, for example, cranes are described feeding with geese in grain fields. Cranes are mentioned in accounts of the DeSoto and Coronado expeditions as well as the travels of Bishop Alonso de la Mota y Escobar. Unfortunately, these accounts do not adequately describe the birds for species identification. Only, the Florentine Codex by Fray Bernardino de Sahagun provides a description of the sandhill crane (G. canadensis) from near Mexico City at the time of Spanish conquest of the Aztecs. Continued searches of early Spanish language publications might yield more information of the historic distribution of cranes in Mexico

    Implementation of routine first trimester combined screening for pre-eclampsia: a clinical effectiveness study.

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    OBJECTIVE: Evaluate clinical effectiveness of the first trimester combined (FMF) pre-eclampsia screening programme when implemented in a public healthcare setting. DESIGN: Retrospective cohort study. SETTING: London tertiary hospital from January 2017 to March 2019. METHODS: 7720 women screened for pre-eclampsia according to National Institute for Health and Care Excellence (NICE) risk-based guidance and 4841 by the Fetal Medical Foundation (FMF) algorithm which combined maternal risk factors, blood pressure, PAPP-A and uterine artery Doppler indices in the first trimester. High risk was defined by standard NICE criteria in the pre-intervention cohort (prescribed 75 mg aspirin) or a risk of ≥1:50 for preterm pre-eclampsia from the FMF algorithm in the post-intervention cohort (prescribed 150 mg aspirin). MAIN OUTCOME MEASURES: Screening effectiveness, rates of pre-eclampsia. RESULTS: The FMF screening programme resulted in a significant reduction in the screen-positive rate (16.1 versus 8.2%, odds ratio [OR] 0.50, 95% confidence interval [CI] 0.41-0.53) with a concurrent increase in targeted aspirin use in women classified as high risk for pre-eclampsia (28.9 versus 99.0%, OR 241.6, 95% CI 89.6-652.0). Screening indices were uniformly improved for the FMF algorithm with receiver operating characteristic (ROC) analysis demonstrating excellent discrimination for preterm pre-eclampsia (area under the curve [AUC] = 0.846, 95% CI 0.778-0.915, P value <.001). Interrupted time series analysis showed that the FMF screening programme resulted in a significant 21-month relative effect reduction of 80% (P = .025) and 89% (P = .017), for preterm and early pre-eclampsia, respectively. CONCLUSIONS: First trimester combined screening for pre-eclampsia is both feasible and effective in a public healthcare setting. Such an approach results in a two-fold de-escalation of risk, doubling of pre-eclampsia detection, near total physician compliance of aspirin use and a significant reduction in the prevalence of preterm pre-eclampsia. TWEETABLE ABSTRACT: Implementation of 1st trimester combined pre-eclampsia screening effectively reduces prevalence of the disorder

    Niche partitioning of feather mites within a seabird host, Calonectris borealis

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    According to classic niche theory, species can coexist in heterogeneous environments by reducing interspecific competition via niche partitioning, e.g. trophic or spatial partitioning. However, support for the role of competition on niche partitioning remains controversial. Here, we tested for spatial and trophic partitioning in feather mites, a diverse and abundant group of arthropods. We focused on the two dominant mite species, Microspalax brevipes and Zachvatkinia ovata, inhabiting flight feathers of the Cory's shearwater, Calonectris borealis. We performed mite counts across and within primary and tail feathers on free-living shearwaters breeding on an oceanic island (Gran Canaria, Canary Islands). We then investigated trophic relationships between the two mite species and the host using stable isotope analyses of carbon and nitrogen on mite tissues and potential host food sources. The distribution of the two mite species showed clear spatial segregation among feathers; M. brevipes showed high preference for the central wing primary feathers, whereas Z. ovata was restricted to the two outermost primaries. Morphological differences between M. brevipes and Z. ovata support an adaptive basis for the spatial segregation of the two mite species. However, the two mites overlap in some central primaries and statistical modeling showed that Z. ovata tends to outcompete M. brevipes. Isotopic analyses indicated similar isotopic values for the two mite species and a strong correlation in carbon signatures between mites inhabiting the same individual host suggesting that diet is mainly based on shared host-associated resources. Among the four candidate tissues examined (blood, feather remains, skin remains and preen gland oil), we conclude that the diet is most likely dominated by preen gland oil, while the contribution of exogenous material to mite diets is less marked. Our results indicate that ongoing competition for space and resources plays a central role in structuring feather mite communities. They also illustrate that symbiotic infracommunities are excellent model systems to study trophic ecology, and can improve our understanding of mechanisms of niche differentiation and species coexistence

    Influence of Polyol/Crosslinker Blend Composition on Phase Separation and Thermo-Mechanical Properties of Polyurethane Thin Films

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    [EN] Polyurethanes (PUs) from Polyethylene glycol (PEG) and polycaprolactone diol (PCL) and a crosslinker, Pentaerythritol (PE), were synthetized with isophorone diisocyanate (IPDI). In this study, we investigated the effect of polyol and crosslinker composition on phase separation and thermo-mechanical properties. The properties were studied through dynamic mechanical analysis, X-ray scattering, atomic force microscopy (AFM), and thermogravimetric analysis (TGA). The results showed changes in PUs properties, microphase structure, and separation due to the composition of polyol/crosslinker blend. So, the largest concentration of PE produced multimodal loss factor patterns, indicating segment segregation while PUs with a PEG/PCL = 1 displayed a monomodal loss factor pattern, indicating a homogeneously distributed microphase separation. Additionally, the increase of the PEG concentration enhanced the damping capacity. On the other hand, agglomeration and thread-like structures of hard segments (HS) were observed through AFM. Finally, the thermal behavior of PUs was affected by chemical composition. Lower concentration of PE reduced the crosslinking; hence, the temperature with the maximum degradation rate.This work was supported by: Universidad de La Sabana (Grant number ING-176-2016); COLCIENCIAS, today Minister of Science, Technology and Innovation of the republic of Colombia, (Grant number 808-2018); Fondo Francisco Jose de Caldas (Contract number CT22-2017). CIBER-BBN is an initiative funded by the VI National R&D & I Plan 2008-2011, "IniciativaIngenio 2010", Consolider Program. CIBER actions are financed by the "Instituto de Salud Carlos III" with assistance from the European Regional Development Fund. DocumentArevalo-Alquichire, S.; Morales-Gonzalez, M.; Navas-Gomez, K.; Diaz, LE.; Gómez-Tejedor, J.; Serrano, M.; Valero, MF. (2020). Influence of Polyol/Crosslinker Blend Composition on Phase Separation and Thermo-Mechanical Properties of Polyurethane Thin Films. Polymers. 12(3):1-13. https://doi.org/10.3390/polym12030666S113123Kim, H.-N., Lee, D.-W., Ryu, H., Song, G.-S., & Lee, D.-S. (2019). Preparation and Characterization of Isosorbide-Based Self-Healable Polyurethane Elastomers with Thermally Reversible Bonds. Molecules, 24(6), 1061. doi:10.3390/molecules24061061Arévalo-Alquichire, S., Morales-Gonzalez, M., Diaz, L., & Valero, M. (2018). Surface Response Methodology-Based Mixture Design to Study the Influence of Polyol Blend Composition on Polyurethanes’ Properties. Molecules, 23(8), 1942. doi:10.3390/molecules23081942Brzeska, J., Elert, A., Morawska, M., Sikorska, W., Kowalczuk, M., & Rutkowska, M. (2018). Branched Polyurethanes Based on Synthetic Polyhydroxybutyrate with Tunable Structure and Properties. Polymers, 10(8), 826. doi:10.3390/polym10080826Klinedinst, D. B., Yilgör, I., Yilgör, E., Zhang, M., & Wilkes, G. L. (2012). The effect of varying soft and hard segment length on the structure–property relationships of segmented polyurethanes based on a linear symmetric diisocyanate, 1,4-butanediol and PTMO soft segments. Polymer, 53(23), 5358-5366. doi:10.1016/j.polymer.2012.08.005Guazzini, T., Bronco, S., Carignani, E., & Pizzanelli, S. (2019). Tunable ionization degree in cationic polyurethanes and effects on phase separation. European Polymer Journal, 114, 298-307. doi:10.1016/j.eurpolymj.2019.02.023Ordon, K., Szlachta, M., Szatkowski, P., & Pielichowska, K. (2019). Examining the effect of starch and hydroxyapatite crosslinking on the thermal properties of polyurethane-based biomaterials. Thermochimica Acta, 682, 178414. doi:10.1016/j.tca.2019.178414Mondal, S., & Martin, D. (2012). Hydrolytic degradation of segmented polyurethane copolymers for biomedical applications. Polymer Degradation and Stability, 97(8), 1553-1561. doi:10.1016/j.polymdegradstab.2012.04.008Wang, C., Xie, J., Xiao, X., Chen, S., & Wang, Y. (2019). Development of Nontoxic Biodegradable Polyurethanes Based on Polyhydroxyalkanoate and L-lysine Diisocyanate with Improved Mechanical Properties as New Elastomers Scaffolds. Polymers, 11(12), 1927. doi:10.3390/polym11121927Li, J.-W., Lee, H.-T., Tsai, H.-A., Suen, M.-C., & Chiu, C.-W. (2018). Synthesis and Properties of Novel Polyurethanes Containing Long-Segment Fluorinated Chain Extenders. Polymers, 10(11), 1292. doi:10.3390/polym10111292Amrollahi, M., Sadeghi, G. M. M., & Kashcooli, Y. (2011). Investigation of novel polyurethane elastomeric networks based on polybutadiene-ol/polypropyleneoxide mixture and their structure–properties relationship. Materials & Design, 32(7), 3933-3941. doi:10.1016/j.matdes.2011.02.039Tan, C., Tirri, T., & Wilen, C.-E. (2017). Investigation on the Influence of Chain Extenders on the Performance of One-Component Moisture-Curable Polyurethane Adhesives. Polymers, 9(12), 184. doi:10.3390/polym9050184Imre, B., Gojzewski, H., Check, C., Chartoff, R., & Vancso, G. J. (2017). Properties and Phase Structure of Polycaprolactone-Based Segmented Polyurethanes with Varying Hard and Soft Segments: Effects of Processing Conditions. Macromolecular Chemistry and Physics, 219(2), 1700214. doi:10.1002/macp.201700214Mondal, S., & Hu, J. L. (2006). Structural characterization and mass transfer properties of nonporous segmented polyurethane membrane: Influence of hydrophilic and carboxylic group. Journal of Membrane Science, 274(1-2), 219-226. doi:10.1016/j.memsci.2005.08.016Coleman, M. M., Pehlert, G. J., & Painter, P. C. (1996). Functional Group Accessibility in Hydrogen Bonded Polymer Blends. Macromolecules, 29(21), 6820-6831. doi:10.1021/ma9604045Lei, W., Zhou, X., Fang, C., Li, Y., Song, Y., Wang, C., & Huang, Z. (2019). New approach to recycle office waste paper: Reinforcement for polyurethane with nano cellulose crystals extracted from waste paper. Waste Management, 95, 59-69. doi:10.1016/j.wasman.2019.06.003Lei, W., Fang, C., Zhou, X., Li, Y., & Pu, M. (2018). Polyurethane elastomer composites reinforced with waste natural cellulosic fibers from office paper in thermal properties. Carbohydrate Polymers, 197, 385-394. doi:10.1016/j.carbpol.2018.06.036Ma, C., Chen, E., Sun, T., Shi, S., & Fang, Q. (2012). Preparation and characterization of tetrapod-shaped ZnO whisker filled polyurethane cross-linked epoxy/polyurethane damping composites. Journal of Reinforced Plastics and Composites, 31(22), 1564-1575. doi:10.1177/0731684412446856HUDA, M., DRZAL, L., MOHANTY, A., & MISRA, M. (2006). Chopped glass and recycled newspaper as reinforcement fibers in injection molded poly(lactic acid) (PLA) composites: A comparative study. Composites Science and Technology, 66(11-12), 1813-1824. doi:10.1016/j.compscitech.2005.10.015Li, T., Zheng, T., Han, J., Liu, Z., Guo, Z.-X., Zhuang, Z., … Guo, B.-H. (2019). Effects of Diisocyanate Structure and Disulfide Chain Extender on Hard Segmental Packing and Self-Healing Property of Polyurea Elastomers. Polymers, 11(5), 838. doi:10.3390/polym11050838Cao, Q., & Liu, P. (2007). Crystalline-amorphous phase transition of hyperbranched polyurethane phase change materials for energy storage. Journal of Materials Science, 42(14), 5661-5665. doi:10.1007/s10853-006-0884-zPang, G. K. ., Baba-Kishi, K. ., & Patel, A. (2000). Topographic and phase-contrast imaging in atomic force microscopy. Ultramicroscopy, 81(2), 35-40. doi:10.1016/s0304-3991(99)00164-3Lu, X., Xu, M., Sheng, Y., Li, Z., & Li, H. (2019). Preparation of polyurethanes with broad damping temperature range and self-healing properties. Journal of Elastomers & Plastics, 52(5), 410-431. doi:10.1177/0095244319863153Schön, P., Bagdi, K., Molnár, K., Markus, P., Pukánszky, B., & Julius Vancso, G. (2011). Quantitative mapping of elastic moduli at the nanoscale in phase separated polyurethanes by AFM. European Polymer Journal, 47(4), 692-698. doi:10.1016/j.eurpolymj.2010.09.029Sui, H. L., Liu, X. Y., Zhong, F. C., Li, X. Y., & Ju, X. (2013). A study of radiation effects on polyester urethane using two-dimensional correlation analysis based on thermogravimetric data. Polymer Degradation and Stability, 98(1), 255-260. doi:10.1016/j.polymdegradstab.2012.10.003Parcheta, P., Głowińska, E., & Datta, J. (2020). Effect of bio-based components on the chemical structure, thermal stability and mechanical properties of green thermoplastic polyurethane elastomers. European Polymer Journal, 123, 109422. doi:10.1016/j.eurpolymj.2019.10942

    Sensitivity of tumor cells towards CIGB-300 anticancer peptide relies on its nucleolar localization

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    CIGB-300 is a novel anticancer peptide that impairs the casein kinase 2-mediated phosphorylation by direct binding to the conserved phosphoacceptor site on their substrates. Previous findings indicated that CIGB-300 inhibits tumor cell proliferation in vitro and induces tumor growth delay in vivo in cancer animal models. Interestingly, we had previously demonstrated that the putative oncogene B23/nucleophosmin (NPM) is the major intracellular target for CIGB-300 in a sensitive human lung cancer cell line. However, the ability of this peptide to target B23/NPM in cancer cells with differential CIGB-300 response phenotype remained to be determined. Interestingly, in this work, we evidenced that CIGB-300's antiproliferative activity on tumor cells strongly correlates with its nucleolar localization, the main subcellular localization of the previously identified B23/NPM target. Likewise, using CIGB-300 equipotent doses (concentration that inhibits 50% of proliferation), we demonstrated that this peptide interacts and inhibits B23/NPM phosphorylation in different cancer cell lines as evidenced by in vivo pull-down and metabolic labeling experiments. Moreover, such inhibition was followed by a fast apoptosis on CIGB-300-treated cells and also an impairment of cell cycle progression mainly after 5 h of treatment. Altogether, our data not only validates B23/NPM as a main target for CIGB-300 in cancer cells but also provides the first experimental clues to explain their differential antiproliferative response. Importantly, our findings suggest that further improvements to this cell penetrating peptide-based drug should entail its more efficient intracellular delivery at such subcellular localization.Fil: Perera, Yasser. Centro de Ingeniería Genética y Biotecnología; CubaFil: Costales, Heydi C.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Diaz, Yakelin. Centro de Ingeniería Genética y Biotecnología; CubaFil: Reyes, Osvaldo. Centro de Ingeniería Genética y Biotecnología; CubaFil: Farina, Hernán Gabriel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mendez, Lissandra. Centro de Ingeniería Genética y Biotecnología; CubaFil: Gómez, Roberto E.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Acevedo, Boris E.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Gomez, Daniel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perea, Silvio E.. Centro de Ingeniería Genética y Biotecnología; Cub

    Search for the rare decay Λc+ →pμ+μ-

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    The flavor-changing neutral-current (FCNC) decay Λþ c → pμþμ− (inclusion of the charge-conjugate processes is implied throughout) is expected to be heavily suppressed in the Standard Model (SM) by the Glashow-IliopoulosMaiani mechanism [1]. The branching fractions for shortdistance c → ulþl− contributions to the transition are expected to be of Oð10−9Þ in the SM but can be enhanced by effects beyond the SM. However, long-distance contributions proceeding via a tree-level amplitude, with an intermediate meson resonance decaying into a dimuon pair [2,3], can increase the branching fraction up to Oð10−6Þ [4]. The short-distance and hadronic contributions can be separated by splitting the data set into relevant regions of dimuon mass. The Λþ c → pμþμ− decay has been previously searched for by the BABAR Collaboration [5], yielding 11.1 5.0 2.5 events and an upper limit on the branching fraction of 4.4 × 10−5 at 90% C.L. Similar FCNC transitions for the b-quark system (b → slþl−) exhibit a pattern of consistent deviations from the current SM predictions both in branching fractions [6] and angular observables [7], with the combined significance reaching 4 to 5 standard deviations [8,9]. Processes involving c → ulþl− transitions are far less explored at both the experimental and theoretical levels, which makes such measurements desirable. Similar analyses of the D system have reported evidence for the longdistance contribution [10]; however, the short-distance contributions have not been established [11]

    Perspectivas literarias: traducción e intertextualidad

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    En este libro hemos reunido un conjunto de trabajos que exploran temas relacionados con la traducción literaria y con los estudios literarios desde una perspectiva múltiple y comparada, pues creemos que, en estos tiempos, es valioso detenerse a analizar experiencias complejas con respecto a las prácticas literarias que permiten la comunicación intercultural, ya que ésta es una vía para cuestionar visiones nacionalistas que, en ocasiones, tienden a achatar el panorama en lugar de reconocer la hibridez y la heterogeneidad de los discursos literarios. Se trata de analizar estos temas desde distintos ángulos, tales como la traducción, las intertextualidades temáticas, la formación de traductores, la perspectiva de los lectores, la construcción del canon por distintas instancias culturales y los estudios comparados

    Non-invasive ventilation in obesity hypoventilation syndrome without severe obstructive sleep apnoea

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    Background Non-invasive ventilation (NIV) is an effective form of treatment in patients with obesity hypoventilation syndrome (OHS) who have concomitant severe obstructive sleep apnoea (OSA). However, there is a paucity of evidence on the efficacy of NIV in patients with OHS without severe OSA. We performed a multicentre randomised clinical trial to determine the comparative efficacy of NIV versus lifestyle modification (control group) using daytime arterial carbon dioxide tension (PaCO2) as the main outcome measure. Methods Between May 2009 and December 2014 we sequentially screened patients with OHS without severe OSA. Participants were randomised to NIV versus lifestyle modification and were followed for 2 months. Arterial blood gas parameters, clinical symptoms, health-related quality of life assessments, polysomnography, spirometry, 6-min walk distance test, blood pressure measurements and healthcare resource utilisation were evaluated. Statistical analysis was performed using intention-to-treat analysis. Results A total of 365 patients were screened of whom 58 were excluded. Severe OSA was present in 221 and the remaining 86 patients without severe OSA were randomised. NIV led to a significantly larger improvement in PaCO2 of -6 (95% CI -7.7 to -4.2) mm Hg versus -2.8 (95% CI -4.3 to -1.3) mm Hg, (p<0.001) and serum bicarbonate of -3.4 (95% CI -4.5 to -2.3) versus -1 (95% CI -1.7 to -0.2 95% CI) mmol/L (p<0.001). PaCO2 change adjusted for NIV compliance did not further improve the inter-group statistical significance. Sleepiness, some health-related quality of life assessments and polysomnographic parameters improved significantly more with NIV than with lifestyle modification. Additionally, there was a tendency towards lower healthcare resource utilisation in the NIV group. Conclusions NIV is more effective than lifestyle modification in improving daytime PaCO2, sleepiness and polysomnographic parameters. Long-term prospective studies are necessary to determine whether NIV reduces healthcare resource utilisation, cardiovascular events and mortality
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