320 research outputs found

    Ice Dynamics and Morphological Changes During Proglacial Lake Development at Exploradores Glacier, Patagonia

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    Proglacial lakes are ubiquitous features formed during deglaciarization and are currently increasing in number in Patagonia and elsewhere. Proglacial lakes can affect glacier dynamics, catchment hydrology and have the potential to cause glacial lake outburst floods. Therefore, monitoring the onset and development of proglacial lake formation is relevant to understand glacial processes and anticipate glacier response to climate change. In this study, we integrate geomorphological and ice-dynamic information to assess proglacial lake development in Exploradores Glacier, Chilean Patagonia. We monitor recent spatial and temporal changes in the lower trunk of Exploradores Glacier (10 km2) to provide a 20-year observation record by combining eight uncrewed aerial vehicles (UAV) surveys between 2019 and 2020, with high-medium resolution satellite imagery (Rapid Eye and Landsat) between 2000 and 2018. We use feature tracking techniques, digital surface elevation model analysis and field data to create a multi-temporal scale (inter-annual and seasonal) and a multi-spatial (cm to km) data set. Our analysis shows that surface velocity overall trend has not changed over the last 20 years and that surface velocity near the terminus is significant (>10 m a−1). Moreover, an exceptional advance over moraine deposits was detected. We also found low downwasting rates (<0.5 m a−1) close to the glacier terminus which are attributed to sufficient ice flux and the insulation effect of the debris-covered surface. However, hundreds of supraglacial ponds were observed and are currently coalescing and expanding by ice-cliff backwasting favoring glacier disintegration. Lastly, it was found that calving losses at the east marginal lake equaled ice-flux input into the lake for the UAV monitored period. This study contributes to a better understanding of glacial lake dynamics during proglacial lake development, and our results may help ice modelling efforts to predict glacier response to future climate scenarios

    The Internationalisation of the Spanish food industry: The home market effect and European market integration

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    The objective of this study was to analyse, from a long-term perspective, the factors determining the process of the internationalisation of the Spanish agrifood industry. The paper concentrates on the empirical verification of the existence of a home market effect in the food and drink industries in Spain and on the effects on trade flows of integration into the European Union. With this aim in mind, we took into account the latest contributions to the estimation of the gravity equation for a sample of export flows from 13 agrifood subsectors between 1970 and 2012, with a destination of 175 markets. From the results of the study the existence of the “home market effect” stands out as the determining factor of the increasing process of internationalisation in the majority of the subsectors of the food industry. On this point, the presence of this effect is remarkable in the most dynamic industries, where the process of restructuring caused by the development of the internal market was more intense. Furthermore, the influence of the process of European integration has been shown by the literature to be a very important factor. Our results qualify in part the results of previous studies, since the positive effect appeared later than expected. The positive effects did not appear until the completion of the process of transition by the dismantling of the barriers established in the treaty of accession to the European Union

    Anti-biofilm multi drug-loaded 3D printed hearing aids

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    Over 5% of the world's population has disabling hearing loss, which affects approximately one third of individuals over 65 years. Hearing aids are commonly used in this population group, but prolonged use of these devices may cause ear infections. We describe for the first time, the use of 3D printing to fabricate hearing aids loaded with two antibiotics, ciprofloxacin and fluocinolone acetonide. Digital light processing 3D printing was employed to manufacture hearing aids from two polymer resins, ENG hard and Flexible. The inclusion of the antibiotics did not affect the mechanical properties of the hearing aids. All multi-drug-loaded devices exhibited a hydrophilic surface, excellent blood compatibility and anti-biofilm activity against P. aeruginosa and S. aureus. Hearing aids loaded with ciprofloxacin (6% w/w) and fluocinolone acetonide (0.5% w/w) sustained drug release for more than two weeks and inhibited biofilm formation on the surface of the devices and bacteria growth in the surrounding medium. In summary, this work highlights the potential of vat photopolymerization 3D printing as a versatile manufacturing approach to fabricate high-fidelity patient-specific medical devices with anti-bacterial properties

    Differential Regulation of Horizontally Acquired and Core Genome Genes by the Bacterial Modulator H-NS

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    Horizontal acquisition of DNA by bacteria dramatically increases genetic diversity and hence successful bacterial colonization of several niches, including the human host. A relevant issue is how this newly acquired DNA interacts and integrates in the regulatory networks of the bacterial cell. The global modulator H-NS targets both core genome and HGT genes and silences gene expression in response to external stimuli such as osmolarity and temperature. Here we provide evidence that H-NS discriminates and differentially modulates core and HGT DNA. As an example of this, plasmid R27-encoded H-NS protein has evolved to selectively silence HGT genes and does not interfere with core genome regulation. In turn, differential regulation of both gene lineages by resident chromosomal H-NS requires a helper protein: the Hha protein. Tight silencing of HGT DNA is accomplished by H-NS-Hha complexes. In contrast, core genes are modulated by H-NS homoligomers. Remarkably, the presence of Hha-like proteins is restricted to the Enterobacteriaceae. In addition, conjugative plasmids encoding H-NS variants have hitherto been isolated only from members of the family. Thus, the H-NS system in enteric bacteria presents unique evolutionary features. The capacity to selectively discriminate between core and HGT DNA may help to maintain horizontally transmitted DNA in silent form and may give these bacteria a competitive advantage in adapting to new environments, including host colonization

    Coal and plastic waste co-pyrolysis by thermal analysis–mass spectrometry

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    Simultaneous thermogravimetry–mass spectrometry studies of a pyrolytic decomposition of mixtures of different plastic wastes/coking coal were carried out. The investigation was performed at temperatures up to 1000 °C in a helium atmosphere under dynamic conditions at a heating rate of 25 °C/min. Five thermoplastics, commonly found in municipal wastes: low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and a plastic mixture rich in polyolefins were selected. Thermogravimetric parameters, together with different characteristic ion fragments from selected libraries of evolving products during the co-pyrolysis process were monitored, such as hydrogen, CO2 and aliphatic and aromatic hydrocarbons. Based on the results obtained, a synergistic effect between coal and individual residues has been found. The maximum interaction occurs at temperatures close to the maximum release of volatile matter of the plastic waste. There is a delay in the decomposition of the plastics that together with the changes in the composition of the volatile matter evolved, promote interactions between the components and have negative effects on coal fluidity. The polyolefinic wastes (HDPE, LDPE and PP) degrade at temperatures close to that of maximum coal degradation, modifying the thermal behaviour of the coal to a lesser degree. However, PS and PET, that release their volatile matter mostly in the early stage of the coal decomposition, show a more pronounced influence on the thermal behaviour. Moreover, the kinetic data demonstrates that the addition of polyolefins increases the energy required to initiate pyrolysis compared to PS and PET. All of these results agree with the fact that polyolefins reduce coal fluidity in a more moderate way than PET and PS

    Interaction of Mesoporous Silica Nanoparticles with Human Red Blood Cell Membranes: Size and Surface Effects

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    The interactions of mesoporous silica nanoparticles (MSNs) of different particle sizes and surface properties with human red blood cell (RBC) membranes were investigated by membrane filtration, flow cytometry, and various microscopic techniques. Small MCM-41-type MSNs (∼100 nm) were found to adsorb to the surface of RBCs without disturbing the membrane or morphology. In contrast, adsorption of large SBA-15-type MSNs (∼600 nm) to RBCs induced a strong local membrane deformation leading to spiculation of RBCs, internalization of the particles, and eventual hemolysis. In addition, the relationship between the degree of MSN surface functionalization and the degree of its interaction with RBC, as well as the effect of RBC−MSN interaction on cellular deformability, were investigated. The results presented here provide a better understanding of the mechanisms of RBC−MSN interaction and the hemolytic activity of MSNs and will assist in the rational design of hemocompatible MSNs for intravenous drug delivery and in vivo imaging

    The Spanish Mediterranean Fishing Guilds (Cofradias): An Example of Collaborative Management with a Key Role in Sustainable Fisheries

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    [EN] The management of Spanish coastal fisheries is based on a mixed model where the centralised action of the government is combined with the self-organisation of fishers in cofradias (guilds). These institutions have economic and political functions, intermediating between the State and the fishing sector and mediating in the conflicts that may occur. They also have welfare and mutualist tasks. This original and traditional co-management model is part of the social capital of traditional Spanish fishing. The aim of this article is to explore the possibilities of these Spanish fishers' organisations in order to improve the legitimacy of the fishery system and the sustainability of fisheries. Our hypothesis is that updating and adapting some aspects of the cofradias model could produce efficient forms of collaborative management and lead to improvements in the sustainability of fisheries. To validate this hypothesis the study analysed 69 face-to-face interviews in 21 Spanish-Mediterranean guilds. The analysis focused on three core aspects: the control of fishing resources; the integration of fishing knowledge in the management system; and, finally, the guilds contribution to the legitimacy of the system in the eyes of the fishers.This work was supported by National Plan for Scientific and Technological Research and Innovation (Spanish Economy and Competitiveness Ministry). Research Project CSO2016-76135-P. There is no conflict of interest declared in this article.Herrera-Racionero, P.; Lizcano, E.; Miret Pastor, LG.; Mascarell, Y. (2019). The Spanish Mediterranean Fishing Guilds (Cofradias): An Example of Collaborative Management with a Key Role in Sustainable Fisheries. Fisheries. 44(4):172-182. https://doi.org/10.1002/fsh.10224S172182444Alegret J. L.1999.Gestión comunitaria cogestión y mercado. La evolución histórica de la gestión de la pesca en el Mediterráneo español. Pages109–124inG.Allut andJ.Pascual editors. Antropología de la pesca/Santiago de Compostela: Asociación Galega de Antropoloxía.La pesca a la Mediterrània 2016 Universidad de Alicante Alicante J. L Alegret J. L. Sánchez Lizaso Les confraries de pescadors a Espanya 47 54Andalusian Decree 86/2004 of March 2 2004 about Fishers Guilds and their Institutions. Available:https://www.juntadeandalucia.es/boja/2004/52/3Ariza, E., Pons, F., & Breton, F. (2016). Is «socio-ecological culture» really being taken into account to manage conflicts in the coastal zone? Inputs from Spanish Mediterranean beaches. Ocean & Coastal Management, 134, 183-193. doi:10.1016/j.ocecoaman.2016.10.006Catalan Law 22/2002 of July 12 2002 of Fishers Guilds. «DOGC» n. 3684. Available:https://www.boe.es/buscar/pdf/2002/BOE-A-2002-15890-consolidado.pdfCochrane, K. L., & Garcia, S. M. (Eds.). (2009). A Fishery Manager’s Guidebook. doi:10.1002/9781444316315Corral-Quintana, S., Legna-de la Nuez, D., Legna Verna, C., Hernández, J. H., & Romero-Manrique de Lara, D. (2016). How to improve strategic decision-making in complex systems when only qualitative information is available. Land Use Policy, 50, 83-101. doi:10.1016/j.landusepol.2015.09.0045. European Comission.2013.Commission implementing regulation6. (EU) Nº 1419/2013. Availablehttp://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32013R1419&from=ES(May2017)European Commission.2014.Coastal zones: achieving sustainable management. Availablehttp://ec.europa.eu/environment/integration/research/newsalert/pdf/coastal_zones_sustainable_management_46si_en.pdf(May 2017).European Parliament.2012.Common position on the role of the RACS in the future Common Fisheries Policy Reform. Available:http://www.europarl.europa.eu/document/activities/cont/201203/20120322ATT41696/20120322ATT41696EN.pdf(May 2017).Frangoudes, K., Marugán-Pintos, B., & Pascual-Fernández, J. J. (2008). From open access to co-governance and conservation: The case of women shellfish collectors in Galicia (Spain). Marine Policy, 32(2), 223-232. doi:10.1016/j.marpol.2007.09.007Herrera-Racionero, P., Lizcano-Fernández, E., & Miret-Pastor, L. (2015). «Us» and «them». Fishermen from Gandía and the loss of institutional legitimacy. Marine Policy, 54, 130-136. doi:10.1016/j.marpol.2014.12.018Jentoft, S. (2000). Legitimacy and disappointment in fisheries management. Marine Policy, 24(2), 141-148. doi:10.1016/s0308-597x(99)00025-1Kosamu, I. B. M. (2015). Conditions for sustainability of small-scale fisheries in developing countries. Fisheries Research, 161, 365-373. doi:10.1016/j.fishres.2014.09.002Law 2/2007 of March 12 2007 of Marine Fishery and Aquaculture of Murcia region. Available inhttps://www.boe.es/boe/dias/2008/07/21/pdfs/A31793-31815.pdf(November 2018)Long, R. D., Charles, A., & Stephenson, R. L. (2015). Key principles of marine ecosystem-based management. Marine Policy, 57, 53-60. doi:10.1016/j.marpol.2015.01.013Mackinson, S., Wilson, D. C., Galiay, P., & Deas, B. (2011). Engaging stakeholders in fisheries and marine research. Marine Policy, 35(1), 18-24. doi:10.1016/j.marpol.2010.07.003MAGRAMA (Ministry of Agriculture Food and Environment).2015.Estadísticas pesqueras: Pesca marítima. Availablehttp://www.magrama.gob.es/es/estadistica/temas/estadisticas-pesqueras/pesca-maritima/(July 2017)Martínez-Novo, R., Lizcano, E., Herrera-Racionero, P., & Miret-Pastor, L. (2016). Innovation or ‘Inventions’? The conflict between latent assumptions in marine aquaculture and local fishery. Public Understanding of Science, 27(2), 214-228. doi:10.1177/0963662516651358Noy, C. (2008). Sampling Knowledge: The Hermeneutics of Snowball Sampling in Qualitative Research. International Journal of Social Research Methodology, 11(4), 327-344. doi:10.1080/13645570701401305Ostrom, E. (2009). A General Framework for Analyzing Sustainability of Social-Ecological Systems. Science, 325(5939), 419-422. doi:10.1126/science.1172133Pita, P., Fernández-Vidal, D., García-Galdo, J., & Muíño, R. (2016). The use of the traditional ecological knowledge of fishermen, cost-effective tools and participatory models in artisanal fisheries: Towards the co-management of common octopus in Galicia (NW Spain). Fisheries Research, 178, 4-12. doi:10.1016/j.fishres.2015.07.021Producer organisations are officially recognised bodies set up by fishery or aquaculture producers. They play an essential role in running the European Common Fisheries Policy.State Marine Fishery Law: Law 3/2001 of March 26 2001. BOE (State Official Gazette) number 75. Available:https://www.boe.es/buscar/doc.php?id=BOE-A-2001-600

    Investigation of the mechanism of chromium removal in (3-aminopropyl)trimethoxysilane functionalized mesoporous silica

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    We are proposed that a possible mechanism for Cr(VI) removal by functionalized mesoporous silica. Mesoporous silica was functionalized with (3-aminopropyl)trimethoxysilane (APTMS) using the post-synthesis grafting method. The synthesized materials were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), N-2 adsorption-desorption analysis, Fourier-transform infrared (FT-IR), thermogravimetric analyses (TGA), and X-ray photoelectron spectroscopy (XPS) to confirm the pore structure and functionalization of amine groups, and were subsequently used as adsorbents for the removal of Cr(VI) from aqueous solution. As the concentration of APTMS increases from 0.01 M to 0.25 M, the surface area of mesoporous silica decreases from 857.9 m(2)/g to 402.6 m(2)/g. In contrast, Cr(VI) uptake increases from 36.95 mg/g to 83.50 mg/g. This indicates that the enhanced Cr(VI) removal was primarily due to the activity of functional groups. It is thought that the optimum concentration of APTMS for functionalization is approximately 0.05 M. According to XPS data, NH3+ and protonated NH2 from APTMS adsorbed anionic Cr(VI) by electrostatic interaction and changed the solution pH. Equilibrium data are well fitted by Temkin and Sips isotherms. This research shows promising results for the application of amino functionalized mesoporous silica as an adsorbent to removal Cr(VI) from aqueous solution

    Bioresponsive Mesoporous Silica Nanoparticles for Triggered Drug Release

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    Mesoporous silica nanoparticles (MSNPs) have garnered a great deal of attention as potential carriers for therapeutic payloads. However, achieving triggered drug release from MSNPs in vivo has been challenging. Here, we describe the synthesis of stimulus-responsive polymer-coated MSNPs and the loading of therapeutics into both the core and shell domains. We characterize MSNP drug-eluting properties in vitro and demonstrate that the polymer-coated MSNPs release doxorubicin in response to proteases present at a tumor site in vivo, resulting in cellular apoptosis. These results demonstrate the utility of polymer-coated nanoparticles in specifically delivering an antitumor payload.National Science Foundation (U.S.) (grant R01-CA124427)National Science Foundation (U.S.) (grant U54-CA119349)National Science Foundation (U.S.) (grant U54-CA119335
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