111 research outputs found

    Insect and insect-inspired aerodynamics: unsteadiness, structural mechanics and flight control

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    Flying insects impress by their versatility and have been a recurrent source of inspiration for engineering devices. A large body of literature has focused on various aspects of insect flight, with an essential part dedicated to the dynamics of flapping wings and their intrinsically unsteady aerodynamic mechanisms. Insect wings flex during flight and a better understanding of structural mechanics and aeroelasticity is emerging. Most recently, insights from solid and fluid mechanics have been integrated with physiological measurements from visual and mechanosensors in the context of flight control in steady airs and through turbulent conditions. We review the key recent advances concerning flight in unsteady environments and how the multi-body mechanics of the insect structure‚ÄČ‚ÄĒ‚ÄČwings and body‚ÄČ‚ÄĒ‚ÄČare at the core of the flight control question. The issues herein should be considered when applying bio-informed design principles to robotic flapping wings

    Rather than resonance, flapping wing flyers may play on aerodynamics to improve performance

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    Saving energy and enhancing performance are secular preoccupations shared by both nature and human beings. In animal locomotion, flapping flyers or swimmers rely on the flexibility of their wings or body to passively increase their efficiency using an appropriate cycle of storing and releasing elastic energy. Despite the convergence of many observations pointing out this feature, the underlying mechanisms explaining how the elastic nature of the wings is related to propulsive efficiency remain unclear. Here we use an experiment with a self-propelled simplified insect model allowing to show how wing compliance governs the performance of flapping flyers. Reducing the description of the flapping wing to a forced oscillator model, we pinpoint different nonlinear effects that can account for the observed behavior ---in particular a set of cubic nonlinearities coming from the clamped-free beam equation used to model the wing and a quadratic damping term representing the fluid drag associated to the fast flapping motion. In contrast to what has been repeatedly suggested in the literature, we show that flapping flyers optimize their performance not by especially looking for resonance to achieve larger flapping amplitudes with less effort, but by tuning the temporal evolution of the wing shape (i.e. the phase dynamics in the oscillator model) to optimize the aerodynamics

    Factors Associated with Influenza Vaccination of Hospitalized Elderly Patients in Spain

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    Vaccination of the elderly is an important factor in limiting the impact of influenza in the community. The aim of this study was to investigate the factors associated with influenza vaccination coverage in hospitalized patients aged ‚Č• 65 years hospitalized due to causes unrelated to influenza in Spain. We carried out a cross-sectional study. Bivariate analysis was performed comparing vaccinated and unvaccinated patients, taking in to account sociodemographic variables and medical risk conditions. Multivariate analysis was performed using multilevel regression models. We included 1038 patients: 602 (58%) had received the influenza vaccine in the 2013-14 season. Three or more general practitioner visits (OR = 1.61; 95% CI 1.19-2.18); influenza vaccination in any of the 3 previous seasons (OR = 13.57; 95% CI 9.45-19.48); and 23-valent pneumococcal polysaccharide vaccination (OR = 1.97; 95% CI 1.38-2.80) were associated with receiving the influenza vaccine. Vaccination coverage of hospitalized elderly people is low in Spain and some predisposing characteristics influence vaccination coverage. Healthcare workers should take these characteristics into account and be encouraged to proactively propose influenza vaccination to all patients aged ‚Č• 65 year

    The words leader/líder and their resonances in an Italo-Latin American multinational corporation

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    ¬© 2017, ¬© The Author(s) 2017. The problems of ‚Äėlost in translation‚Äô are well known. Yet some terms of English managerial vocabulary, which are perfectly translatable in other languages, remain untranslated. One explanation of this phenomenon is what Linguistic anthropology call negative semantic resonances. Semantic resonances focused on the issue of which meanings can or cannot be expressed by a single word in different cultures. In this paper, based on an organisational ethnography of Latin American expatriates working for an Italo-Latin-American multinational corporation (Tubworld), we analyse the resonances of the word leader/l√≠der and director, direttore, capo, guida, coordinador, caudillo among a group of expatriates; all Italian, Spanish or multilingual speakers who use English as a second language in their everyday interactions. The paper explains how the different uses contribute to create a meaning of what a leader should and should not be; someone who leads without leading, sometimes a manager. The authors, an Italian native speaker who learnt Spanish during childhood and use English as his everyday language and a Spanish native speaker, argue that Italian or Spanish speakers not only avoid the words duce and caudillo (the vernacular vocabulary for leader, not in use due to the political and cultural meaning) but also the word leader/l√≠der itself, as it resonate to the other two (violent, authoritarian, autocratic, antidemocratic leadership) but furthermore because the word, a lexical loan from English, failed to encapsulate the complexity of leading multilingual organisations like Tubworld

    Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

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    Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

    Monitoring of species’ genetic diversity in Europe varies greatly and overlooks potential climate change impacts

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    Genetic monitoring of populations currently attracts interest in the context of the Convention on Biological Diversity but needs long-term planning and investments. However, genetic diversity has been largely neglected in biodiversity monitoring, and when addressed, it is treated separately, detached from other conservation issues, such as habitat alteration due to climate change. We report an accounting of efforts to monitor population genetic diversity in Europe (genetic monitoring effort, GME), the evaluation of which can help guide future capacity building and collaboration towards areas most in need of expanded monitoring. Overlaying GME with areas where the ranges of selected species of conservation interest approach current and future climate niche limits helps identify whether GME coincides with anticipated climate change effects on biodiversity. Our analysis suggests that country area, financial resources and conservation policy influence GME, high values of which only partially match species’ joint patterns of limits to suitable climatic conditions. Populations at trailing climatic niche margins probably hold genetic diversity that is important for adaptation to changing climate. Our results illuminate the need in Europe for expanded investment in genetic monitoring across climate gradients occupied by focal species, a need arguably greatest in southeastern European countries. This need could be met in part by expanding the European Union’s Birds and Habitats Directives to fully address the conservation and monitoring of genetic diversity

    VIII Encuentro de Docentes e Investigadores en Historia del Dise√Īo, la Arquitectura y la Ciudad

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    Acta de congresoLa conmemoraci√≥n de los cien a√Īos de la Reforma Universitaria de 1918 se present√≥ como una ocasi√≥n propicia para debatir el rol de la historia, la teor√≠a y la cr√≠tica en la formaci√≥n y en la pr√°ctica profesional de dise√Īadores, arquitectos y urbanistas. En ese marco el VIII Encuentro de Docentes e Investigadores en Historia del Dise√Īo, la Arquitectura y la Ciudad constituy√≥ un espacio de intercambio y reflexi√≥n cuya realizaci√≥n ha sido posible gracias a la colaboraci√≥n entre Facultades de Arquitectura, Urbanismo y Dise√Īo de la Universidad Nacional y la Facultad de Arquitectura de la Universidad Cat√≥lica de C√≥rdoba, contando adem√°s con la activa participaci√≥n de mayor√≠a de las Facultades, Centros e Institutos de Historia de la Arquitectura del pa√≠s y la regi√≥n. Orientado en su convocatoria tanto a docentes como a estudiantes de Arquitectura y Dise√Īo Industrial de todos los niveles de la FAUD-UNC promovi√≥ el debate de ideas a partir de experiencias concretas en instancias tales como mesas tem√°ticas de car√°cter interdisciplinario, que adoptaron la modalidad de presentaci√≥n de ponencias, entre otras actividades. En el √°mbito de VIII Encuentro, desarrollado en la sede Ciudad Universitaria de C√≥rdoba, se desplegaron numerosas posiciones sobre la ense√Īanza, la investigaci√≥n y la formaci√≥n en historia, teor√≠a y cr√≠tica del dise√Īo, la arquitectura y la ciudad; sum√°ndose el aporte realizado a trav√©s de sus respectivas conferencias de Ana Clarisa Ag√ľero, Bibiana Cicutti, Fernando Aliata y Alberto Petrina. El conjunto de ponencias que se publican en este Repositorio de la UNC son el resultado de dos intensas jornadas de exposiciones, cuyos contenidos han posibilitado actualizar viejos dilemas y promover nuevos debates. El evento recibi√≥ el apoyo de las autoridades de la FAUD-UNC, en especial de la Secretar√≠a de Investigaci√≥n y de la Biblioteca de nuestra casa, como as√≠ tambi√©n de la Facultad de Arquitectura de la UCC; va para todos ellos un especial agradecimiento

    Lift, Drag and Flow-Field Measurements Around a Small Ornithopter

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