552 research outputs found
Asymptotic Analysis of a Cucker–Smale System with Leadership and Distributed Delay
No full textWe extend the analysis developed in Pignotti and Reche Vallejo (J Math Anal Appl 464:1313–1332, 2018) [34] in order to prove convergence to consensus results for a Cucker–Smale type model with hierarchical leadership and distributed delay. Flocking estimates are obtained for a general interaction potential with divergent tail. We analyze also the model when the ultimate leader can change its velocity. In this case we give a flocking result under suitable conditions on the leader’s acceleration
Leis e planos urbanos na produção da cidade: o caso de Chapecó, SC
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Urbanismo, História e Arquitetura da CidadeO presente trabalho discute a relação entre as Leis e Planos Urbanos e a organização espacial das cidades. Para isso, desenvolve a análise do Plano de Desenvolvimento Urbano de Chapecó, no Oeste de Santa Catarina, da metade da década de 70 e da Lei de Zoneamento aprovada no início da década de 80. O estudo objetiva compreender, à luz das condições sociais, políticas, econômicas de cada período, que tipo de repercussões espaciais essas Leis e Planos provocaram no espaço urbano de Chapecó, identificando seu papel como indutor de transformações urbanas no município, aliados aos interesses dos demais agentes urbanos, principalmente do capital agroindustrial. Sendo assim, a partir do estudo de um caso concreto relacionando os Planos e Leis Urbanas e sua proposta de intervenção em uma realidade urbana determinada, o trabalho contribui para a discussão dos alcances, limites, potencialidades e, principalmente, as repercussões espaciais atribuídas aos Planos e Leis Urbanas no espaço urbano, dando maior ênfase aos aspectos da distribuição sócio-espacial da população. The present work discusses the relationship between the Urban Laws and Plans and the spatial organization of the cities. For this, it develops the analysis of the Urban Development Planning of Chapecó, in the West of Santa Catarina, from the half of the 70´s and the approved Zoning Law at the beginning of the 80´s. The study aims to understand what kind of spatial consequences these Laws and Plans had provoked in the urban space of Chapecó, considering the social conditions, politics and economy of each period, identifying its roll as an inductive agent of urban transformations in the city, along with the interests of others urban agents, mainly the agroindustrial capital one. This way, from the study of a concrete case relating the Plans and Urban Laws and its proposal of intervention in a determined urban reality, the work contribute for the discussion of the reach, limits, potentialities and, mainly, the spatial consequences attributed to the Plans and Urban Laws in the urban space, putting more emphasis on the aspects of the partner-spatial distribution of the population
Gesta Romanorum
No full textEste volumen de versos constituye la primera traducción al español de una obra de Giovanni Raboni, uno de los poetas italianos más importantes de la segunda mitad del siglo XX. Y además supone la puesta en escena en un solo volumen del puzzle que supuso su primer libro, Gesta Romanorum. El volumen se compone de los textos canónicos y de un cuantioso apéndice que reúne los textos que en su día formaron parte de GR, pero que nunca acompañaron a estos de manera exenta; una noticia inesperada, por lo tanto, también para el lector italiano
La recepción en Italia del Examen de Ingenios de Huarte de San Juan (1575): nuevas perspectivas
No full textEl medico Juan Huarte de San Juan desarrolló la teoría clásica de los humores en su celebre obra Examen de ingenios, donde argumentaba que cada hombre tenía una predisposición natural para ciertas profesiones, determinada por su ‘ingenio’, una capacidad innata y masculina influida por los humores. En el siglo xvii, el médico italiano Pompeo Caimo revisó el trabajo de Huarte en su obra Dell'ingegno humano (1629), donde criticó punto por punto las propuestas de Huarte; de este tratado no existe una edición moderna, y de hecho Caimo es recordado por otras obras. El refutó la idea de la inferioridad intelectual femenina, y reinterpretó los conceptos tradicionales sobre los temperamentos defendiendo la capacidad de las mujeres para el pensamiento crítico
Anxiety and depressive symptoms among youth in Italy, Spain, and Portugal: A three-year post-pandemic study
No full textThe COVID-19 pandemic disrupted the population's lives. Stressful conditions during the lockdown and the reintroduction to a changed social environment emotionally affected children and adolescents. The aim of this work was to study anxiety and depressive symptoms in Italian, Spanish, and Portuguese children and adolescents aged 3 to 18 years at different moments of the COVID-19 pandemic: April 2020 (during confinement), September 2020 (with the schools' reopening), and September 2023 (with the situation restored). Parents of 1,097 children participated in at least one assessment, completing measures of child emotional symptoms online. Cases with subclinical symptoms of anxiety and depression were higher compared to pre-pandemic studies. Overall, anxiety increased from April 2020 to September 2020, decreasing in September 2023 with no differences compared to the first assessment. Depression was high in April 2020 but decreased in September 2020, with no significant differences three years later, in September 2023. Cross-country comparisons at each point are discussed. Moreover, boys showed higher levels of depression during the pandemic compared to girls. Older children, compared to younger ones, had more anxiety and depressive symptoms throughout all the moments. These findings highlight the emotional impact of the pandemic and its conditions on children and adolescents
G-Quadruplex DNA as a Target in Pathogenic Bacteria: Efficacy of an Extended Naphthalene Diimide Ligand and Its Mode of Action
No full textGuanidine DNA quadruplex (G4-DNA) structures convey a distinctive layer of epigenetic information that is critical for regulating key biological activities and processes as transcription, replication, and repair in living cells. The information regarding their role and use as therapeutic drug targets in bacteria is still scarce. Here, we tested the biological activity of a G4-DNA ligand library, based on the naphthalene diimide (NDI) pharmacophore, against both Gram-positive and Gram-negative bacteria. For the best compound identified, NDI-10, a different action mechanism was described for Gram-positive or negative bacteria. This asymmetric activity profile could be related to the different prevalence of putative G4-DNA structures in each group, the influence that they can exert on gene expression, and the different roles of the G4 structures in these bacteria, which seem to promote transcription in Gram-positive bacteria and repress transcription in Gram-negatives
Cuida tu cerebro con deporte: avances neuroeducativos / Take care of your brain with sport: neuroeducational advances
No full textCÓMO CITAR: Castillo, P. (2021). Cuida tu cerebro con deporte: avances neuroeducativos. En J. M. Romero Rodríguez, M. P. Cáceres Reche, J. C. De la Cruz Campos y M. Ramos Navas-Parejo (Eds.), Investigación educativa ante los actuales retos migratorios (pp. 245-260). Dykinson
Engineering challenges in high temperature liquid lead storage for concentrated solar power systems
No full textToday the technical limit for central receiver thermodynamic solar systems (solar towers) is represented by the temperature (about Tmax = 560 ° C) that can be reached with current storage and exchange fluids (molten salts). This paper deals with a full-scale experimental technology test to transfer and improve current technologies by applying the experience, actually consolidated in the field of liquid lead exchangers in nuclear sector, to accumulate solar energy at higher temperature. With the adoption of liquid lead as a means of storing heat and exchange fluid with highly efficient air systems, it is possible to reach and exceed 800 ° C with undoubted advantages in terms of efficiency. This is a real innovative technical gap solved. The adoption of molten lead as a storage and heat exchange material, however, poses important problems both in terms of corrosion and resistance to creep for the temperatures reached, the paper describes the technical solutions adopted to overcome these problems in an unexplored region
Land-use on the watershed determines the quality of water in south-eastern Iberian Peninsula reservoirs
No full text[EN] We studied the total nitrogen (TN) concentration, the total phosphorus (TP) concentration, and the TN/TP ratios in 12 reservoirs located in the southern Iberian Peninsula, to study the influence of land-use in the reservoir watershed on the trophic status of these systems. The TN/TP ratios indicated limitation by P or co-limitation depending on the system. Only the percentage of agriculture areas significantly classified the reservoirs by their P and N concentrations, while the percentage of urban areas also grouped the reservoirs by their N contents, according to the univariate tree regression analyses. We found a positive relationship between the percentage of agriculture areas and the trophic state of the reservoirs, according to the Carlson index (TSI), that indicates a deterioration in water quality in the reservoirs induced by agricultural activity.[ES] Se examinan los contenidos de nitrógeno total (NT), fósforo total (PT) y las relaciones NT/PT, en 12 embalses del sur-este de la Península Ibérica, con objeto de indagar en la influencia del uso del suelo en las cuencas de captación sobre el estado trófico de estos sistemas. Los embalses mostraron relaciones NT/PT que indican limitación por P o co-limitación según el sistema considerado. Según los análisis de regresión en árbol univariados efectuados, sólo el porcentaje de áreas cultivadas clasifica significativamente a los embalses por sus contenidos en P y N, mientras el porcentaje de áreas urbanas agrupa, además, a los embalses por los contenidos en N. La relación positiva encontrada entre el porcentaje de áreas cultivadas y el estado trófico de los embalses, cuantificado según el índice de Carlson (TSI), indica un deterioro en la calidad del agua en los embalses inducido por la actividad agrícola.La financiación para el presente trabajo fue obtenida del Ministerio de Economía y Competitividad (HERA, CGL2014-52362-R), por el Ministerio de Ciencia, Innovación y Universidades (CRONOS RTI2018-098849-B-I00), y fondos FEDER. E.L-P. tuvo un contrato predoctoral de Formación del Profesorado Universitario (FPU014/02917).León-Palmero, E.; Reche, I.; Morales-Baquero, R. (2021). El uso del suelo en las cuencas de captación condiciona la calidad del agua en embalses del sudeste peninsular ibérico. Ingeniería del agua. 25(3):205-213. https://doi.org/10.4995/ia.2021.15690OJS205213253Álvarez-Salgado, X.A., Miller, A.E.J. 1998. Simultaneous determination of dissolved organic carbon and total dissolved nitrogen in seawater by high temperature catalytic oxidation: conditions for precise shipboard measurements, Marine Chemistry, 62(3), 325-333. https://doi.org/10.1016/S0304-4203(98)00037-1American Public Health Association (APHA) 1992. Standard methods for the examination of water and wastewater Washington, DC, USA: American Public Health Association. 18th edn. Edited by A.E. Greenberg, L.S. Clesceri, y A.D. Eaton.Carlson, R.E. 1977. A trophic state index for lakes. Limnology and Oceanography, 22, 361-369. https://doi.org/10.4319/lo.1977.22.2.0361Crawley, M.J. 2002. Statistical computing. An introduction to data analysis using S-Plus. Wiley, Chichester.Downing, J.A., McCauley, E. 1992. The nitrogen:phosphorus relationship in lakes. Limnology and Oceanography, 37(5), 936-945. https://doi.org/10.4319/lo.1992.37.5.0936Hayes, N.M., Deemer, B.R., Corman, J.R., Razavi, N.R., Strock, K.E. 2017. Key differences between lakes and reservoirs modify climate signals: A case for a new conceptual model. Limnology and Oceanography Letter, 2(2), 47-62. https://doi.org/10.1002/lol2.10036Guildford, S.J., Hecky, R.E. 2000. Total nitrogen, total phosphorus, and nutrient limitation in lakes and oceans: Is there a common relationship? Limnology and Oceanography, 45(6), 1213-1223. https://doi.org/10.4319/lo.2000.45.6.1213Knoll, L.B., Hagenbuch, E.J., Stevens, M.H., Vanni, M.J., Renwick, W.H., Denlinger, J.C., Hale, R.S., Gonzalez, M.J. 2015. Predicting eutrophication status in reservoirs at large spatial scales using landscape and morphometric variables. Inland Waters, 5, 203-214. https://doi.org/10.5268/IW-5.3.812León-Palmero, E., Reche, I., Morales-Baquero, R. 2019. Atenuación de luz en embalses del sur-este de la Península Ibérica. Ingeniería del Agua, 23(1), 65-75. https://doi.org/10.4995/Ia.2019.10655León-Palmero, E., Morales-Baquero, R., Reche, I. 2020. Greenhouse gas fluxes from reservoirs determined by watershed lithology, morphometry, and anthropogenic pressure. Environmental Research Letters, 15(4), 044012. https://doi.org/10.1088/1748-9326/ab7467Prats-Rodríguez, J., Morales-Baquero, R., Dolz-Ripollés, J., Armengol-Bachero, J. 2014. Aportaciones de la limnología a la gestión de embalses. Ingeniería del Agua, 18(1), 83-97. https://doi.org/10.4995/ia.2014.3145R Core Team. 2019. R: A Language and Environment for Statistical Computing Vienna, Austria: R Foundation for Statistical Computing. Available at: https://www.R-project.org/.Rockström, J., W. Steffen, K. Noone, Å. Persson, F.S. Chapin, III, E. Lambin, T.M. Lenton, M. Scheffer, C. Folke, H. Schellnhuber, B. Nykvist, C.A. De Wit, T. Hughes, S. van der Leeuw, H. Rodhe, S. Sörlin, P.K. Snyder, R. Costanza, U. Svedin, M. Falkenmark, L. Karlberg, R.W. Corell, V.J. Fabry, J. Hansen, B. Walker, D. Liverman, K. Richardson, P. Crutzen, and J. Foley. 2009. Planetary boundaries: exploring the safe operating space for humanity. Ecology and Society, 14(2), 32. https://doi.org/10.5751/ES-03180-140232Smith, VH., Schindler D.W. 2009. Eutrophication science: where do we go from there? Trends in Ecology and Evolution, 24, 201-207. https://doi.org/10.1016/j.tree.2008.11.009Thornton, K.W., Kimmel B.L., Payne F.E. (eds.) 1990. Reservoir limnology: Ecological perspectives. John Wiley& Sons.Tong, S.T.Y., Chen, W. 2002. Modeling the relationship between land use and surface water quality. Journal of Environmental Management, 66, 377-393. https://doi.org/10.1006/jema.2002.0593Vollenweider, R.A. 1989. Eutrophication. In: Global Freshwater Quality-A First Assessment. (Meybeck, M., D. Chapman, and R. Helmer eds). World Health Organization and the United Nations Environmental Programme, 107-120
Thiosugar naphthalene diimide conjugates: G-quadruplex ligands with antiparasitic and anticancer activity
No full textGlycosyl conjugation to drugs is a strategy being used to take advantage of glucose transporters (GLUT) overexpression in cancer cells in comparison with non-cancerous cells. Its extension to the conjugation of drugs to thiosugars tries to exploit their higher biostability when compared to O-glycosides. Here, we have synthesized a series of thiosugar naphthalene diimide conjugates as G-quadruplex ligands and have explored modifications of the amino sidechain comparing dimethyl amino and morpholino groups. Then, we studied their antiproliferative activity in colon cancer cells, and their antiparasitic activity in T. brucei and L. major parasites, together with their ability to bind quadruplexes and their cellular uptake and location. We observed higher toxicity for the sugar-NDI-NMe2 derivatives than for the sugar-NDI-morph compounds, both in mammalian cells and in parasites. Our experiments indicate that a less efficient binding to quadruplexes and a worse cellular uptake of the carb-NDI-morph derivatives could be the reasons for these differences. We found small variations in cytotoxicity between O-carb-NDIs and S-carb-NDIs, except against non-cancerous human fibroblasts MRC-5, where thiosugar-NDIs tend to be less toxic. This leads to a notable selectivity for β-thiomaltosyl-NDI-NMe2 12 (9.8 fold), with an IC50 of 0.3 μM against HT-29 cells. Finally, the antiparasitic activity observed for the carb-NDI-NMe2 derivatives against T. brucei was in the nanomolar range with a good selectivity index in the range of 30- to 69- fold
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