Cenozoic contractional tectonics in the Fuegian Andes, southernmost South America: a model for the transference of orogenic shortening to the foreland

The Fuegian thrust-fold belt has been subjected to significant shortening during the Cenozoic. Although contemporaneous shortening and uplift was also recognized in the Fuegian Andes central belt (hinterland), previous studies stated that most of that deformation developed out-of-sequence with the thrust-fold belt and hence did not contribute to its shortening. Therefore, no suitable geometric and kinematic model has been proposed for the mechanism that links deformation in both domains. Here we address the style and timing of the younger (Late Cretaceous-Paleogene) structures of the central belt and the structural evolution of the thrust-fold belt, based on published and own data. We reinterpret the style of the central belt structures, proposing a new model in which all the shortening in the foreland cover was caused by basement thrusting in the central belt. We postulate that the basement was involved in a regional-scale duplex whose roof thrust was the décollement of the thin-skinned thrust-fold belt. Therefore, the total slip transferred through the roof thrust accounted for the shortening in the cover rocks. The basement duplex incorporated the underthrust crust from the footwall of the orogenic wedge through forward propagation, in sequence with the thrust-fold belt from the Late Cretaceous to the Miocene.Fil: Torres Carbonell, Pablo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Dimieri, Luis Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Bahía Blanca. Instituto Geológico del Sur; Argentina

Evaluation of strain and structural style variations along the strike of the Fuegian thrust-fold belt front, Argentina

The Fuegian thrust-fold belt (TFB) forms the thin-skinned outer wedge of the Andes in Tierra del Fuego. Using subsurface and outcrop data from two areas (Western and Eastern) of the TFB front in Argentina we aimed to verify and characterize the apparent structural variations along the strike. Both areas reveal pro- and retro-vergent faultrelated folds detached at similar horizons, with a youngest early to middle (?) Miocene deformation age. However, the Western Area has gentle, large-wavelength folds whereas the Eastern Area is characterized by a very tight structural geometry, with closer fold geometries. This difference manifests itself in the shortening of analogous structures: below 5.5% in the west as against ~22% in the Eastern Area. Our findings verify structural style variations along the strike and suggest that the Eastern Area endured higher strain. We evaluate two possible causes of this strain gradient, assuming homogeneous regional shortening: (i) lateral rheological variations at the base of the thrust wedge, namely the occurrence of more competent beds which would have restrained the propagation of the detachment toward the east; and (ii) the effect of strong buttressing in the eastern TFB exerted by the Río Chico arch basement promontory during deformation. Published results, together with our current subsurface and outcrop data, rule out significant rheological gradients in a preferred direction along the TFB. On the other hand, we present evidence of the nucleation of frontal thrusts above basement steps at the Río Chico arch western margin, which comprise local buttresses. We speculate that this buttressing was mantained along the TFB front and is enhanced toward the east, where forward TFB propagation was hindered due to the southern projection of the Río Chico promontory. This would explain the higher strain and more complex structural style in the Eastern AreaEvaluación de variaciones en el grado de deformación y el estilo estructural a lo largo del frente de la faja corrida y plegada Fueguina, Argentina. La faja corrida y plegada Fueguina (FCP) comprende el cinturón de piel fina en el antepaís de los Andes en Tierra del Fuego. Con la finalidad de verificar y caracterizar posibles variaciones estructurales a lo largo del frente de la FCP en Argentina, hemos analizado datos de subsuelo y superficie en dos áreas (occidental y oriental). Ambas revelan pliegues relacionados con fallas, tanto provergentes como retrovergentes, que despegan en niveles similares, y tienen una edad mínima miocena temprana a media (?). Sin embargo, en el área occidental el plegamiento es suave y de alta longitud de onda mientras que en el área oriental la estructura es muy apretada, con pliegues más cerrados. Esta diferencia se manifiesta al comparar el acortamiento en estructuras análogas: menor a 5,5% en el oeste contra ~22% en el área oriental. Por lo tanto, queda verificada la existencia de variaciones en el estilo estructural a lo largo del rumbo, y se pone en evidencia que el área oriental fue sometida a mayor deformación. Evaluamos dos causas posibles para este gradiente de deformación, asumiendo una magnitud de acortamiento regional homogénea: (i) variaciones laterales en la reología de la base de la FCP, por ejemplo capas más competentes hacia el este que podrían haber dificultado la propagación del despegue en ese sector, y (ii) una fuerte obstaculización al avance de la FCP en el este, ejercida por el promontorio de basamento del Arco Río Chico. La información publicada previamente, así como los datos de este trabajo, descartan un gradiente reológico significativos en una dirección preferencial a lo largo de la FCP. Al contrario, nuestros datos evidencian localización de corrimientos frontales sobre escalones en el basamento del Arco Río Chico en el área occidental, que localmente obstaculizan el avance de la deformación. Especulamos con que este efecto obstaculizador se mantuvo a lo largo del frente de la FCP, con mayor intensidad hacia el este, donde el avance de la FCP fue restringido por la proyección austral del arco Río Chico. De esta manera se puede explicar la mayor deformación y el estilo estructural más complejo en el área oriental.Fil: Torres Carbonell, Pablo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Dimieri, Luis Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Bahía Blanca. Instituto Geológico del Sur; Argentina;Fil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

On hidden Markov models and cyclic strings for shape recognition

Shape descriptions and the corresponding matching techniques must be robust to noise and invariant to transformations for their use in recognition tasks. Most transformations are relatively easy to handle when contours are represented by strings. However, starting point invariance is difficult to achieve. One interesting possibility is the use of cyclic strings, which are strings that have no starting and final points. We propose new methodologies to use Hidden Markov Models to classify contours represented by cyclic strings. Experimental results show that our proposals outperform other methods in the literature

Thrust-fold belt kinematics and orogenic growth in Tierra del Fuego, Argentina: implications of backthrusting for critical Coulomb wedge development

Analysis of balanced cross-sections and of the chronostratigraphy of the deformed foreland basin successions allows to solve the structural kinematics of the eastern Fuegian thrust-fold belt. Based on the Coulomb wedge theory, we propose a chronologically and geometrically well-constrained growth history for the frontal Fuegian Andes orogen. The mountain front behaved in a critical manner during the Early Eocene, characterized by forward thrusting. The wedge became subcritical after that, until renewed forward propagation of the thrust front in the Early Miocene. The long period as a subcritical wedge enhanced retrodeformation, recorded by out-of-sequence thrusting and backthrusting. We suggest that backthrusts should be considered an important mechanism for accommodating shortening in subcritical orogenic wedges.Fil: Torres Carbonell, Pablo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Dimieri, Luis Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; ArgentinaFil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Is there life beyond the Spanish government’s aid to furloughed employees by COVID-19?

This paper examines the perceptions of firms in April 2020, one month after the Spanish Government declared the state of alarm, about how the COVID-19 pandemic will affect their business activity in the following months, and what employment decisions they expect to make in response. The data for the study was collected by the Government of the region of Aragon (Spain) through a survey of a non-randomly selected sample of firms located in the region. In addition to prospects and intended actions, firms were asked whether or not they had applied for ERTE aid (the Spanish job retention scheme to contain the pandemic crisis). We find that firms participating (voluntarily and anonymously) in the survey anticipated rather well the severity of the effects of the pandemic in the following months. The ERTE aid helped firms to maintain the jobs of their inactive employees, while firms that did not ask for aid responded by laying off employees. Further, the ERTE aid helped to maintain the jobs of furloughed employees, but the firms receiving ERTE aid expected to lay off the same proportion of employees as firms without that aid, controlling for the different anticipated effects of the pandemic in the two groups of firms

Structural and petrographic constraints on the stratigraphy of the Lapataia Formation, with implications for the tectonic evolution of the Fuegian Andes

The structure of the Fuegian Andes central belt is characterized by a first phase of peak metamorphism and ductile deformation, followed by a brittle-ductile thrusting phase including juxtaposition of different (first phase) structural levels; both related to the closure and inversion of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The second phase involved thrust sheets of pre-Jurassic basement, as well as Upper Jurassic and Lower Cretaceous units from the volcanic-sedimentary fill of the basin. Rock exposures in the Parque Nacional Tierra del Fuego reveal a diversity of metamorphic mineral assemblages, dynamic recrystallization grades and associated structures, evidencing a variety of protoliths and positions in the crust during their orogenic evolution. Among the units present in this sector, the Lapataia Formation portrays the higher metamorphic grade reported in the Argentine side of the Fuegian Andes, and since no precise radiometric ages have been established to date, its stratigraphic position remains a matter of debate: the discussion being whether it belongs to the pre-Jurassic basement, or the Upper Jurassic volcanic/volcaniclastic initial fill of the Rocas Verdes basin. The mapping and petrographic/microstructural study of the Lapataia Formation and those of undoubtedly Mesozoic age, allow to characterize the former as a group of rocks with great lithological affinity with the Upper Jurassic metamorphic rocks found elsewhere in the central belt of the Fuegian Andes. The main differences in metamorphic grade are indebted to its deformation at deeper crustal levels, but during the same stages than the Mesozoic rocks. Accordingly, we interpret the regional structure to be associated with the stacking of thrust sheets from different structural levels through the emplacement of a duplex system during the growth of the Fuegian Andes.Fil: Cao, Sebastián José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego. Instituto de Ciencias Polares, Recursos Naturales y Ambiente; ArgentinaFil: Torres Carbonell, Pablo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Dimieri, Luis Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; Argentin

Plagio y uso de tecnología en estudiantes de secundaria

The use of the different tools and resources available on the web has the potential to affect the level of plagiarism at all educational levels. This article approaches the relationship between the use of Internet resources and the levels of plagiarism among high school students in Ecuador. Quantitatively, 16,546 surveys of high school students were conducted and the students were classified using the k-means method according to the use of Internet tools. Cause-effect relationships were established through logistic regression between classifications and the levels of plagiarism. The results show that Internet skills and student confidence in the Internet directly affect plagiarism levels. It was found that plagiarism depends on the confidence levels of the students and on the variables connection days per week, level of Internet knowledge, hours connected per day and years of experience as an Internet userEl uso de las diferentes herramientas y recursos de la web tiene el potencial de afectar el nivel de plagio. Este artículo aborda la relación entre el uso de recursos de Internet y los niveles de plagio entre estudiantes de secundaria en Ecuador. Cuantitativamente, se realizaron 16.546 encuestas a estudiantes de secundaria y se clasificó a los estudiantes mediante el método de k-medias según el uso de herramientas de Internet. Las relaciones causa-efecto se establecieron mediante regresión logística entre las clasificaciones y los niveles de plagio. Los resultados muestran que las habilidades de Internet y la confianza de los estudiantes en Internet afectan directamente los niveles de plagio. Se encontró que el plagio depende de los niveles de confianza de los estudiantes y de las variables días de conexión a la semana, nivel de conocimiento de Internet, horas conectadas por día y años de experiencia como internaut

COPD severity score as a predictor of failure in exacerbations of COPD. The ESFERA study

SummaryBackgroundExacerbations are a frequent cause of morbidity and mortality in COPD. It is crucial to identify risk factors for failure after treatment of exacerbations of COPD. This study evaluates the COPD severity score (COPDSS) as a predictor of clinical failure, together with other severity, activity and quality of life measurements, in patients with exacerbated COPD.MethodMulticenter, prospective, observational study in ambulatory patients with exacerbation of COPD. The patients completed the COPDSS, the London Chest Activities of Daily Living (LCADL) and the EuroQol 5D (EQ-5D). A follow-up visit was scheduled one month after presentation with the exacerbation to assess the clinical evolution.ResultsA total of 346 patients were included (mean age 68.5 years (SD = 9.5 years and 90.7% male) and mean FEV1(% predicted) 46.9% (SD = 17)). After one month, 28.2% of episodes were classified as failures, with half of them requiring hospital admission. Patients who failed were more frequently active smokers, with more severe dyspnoea at presentation and worse lung function. They had significantly worse scores of COPDSS, LCADL, EQ-5D index and EQ-5D visual analogue score (VAS) and shorter mean time walking per day. ROC analysis of relationship between COPDSS and failure gave AUC 0.72, which improved only to 0.77 when the other significant variables in univariate analysis were considered.ConclusionsClinical failure after ambulatory treatment of exacerbation of COPD is frequent. Usual markers of severity (impaired lung function, active smoking and severe dyspnoea) are associated with failure; however, a short severity questionnaire (COPDSS) provides better predictive value than the usual variables

Interferences in Locally Resonant Sonic Metamaterials Formed from Helmholtz Resonators

[EN] The emergence of materials artificially designed to control the transmission of waves, generally called metamaterials, has been a hot topic in the field of acoustics for several years. The design of these metamaterials is usually carried out by overlapping different wave control mechanisms. An example of this trend is the so-called Locally Resonant Sonic Materials, being one of them the Phononic Crystals with a local resonant structure. These metamaterials are formed by sets of isolated resonators in such a way that the control of the waves is carried out by resonances and by the existence of Bragg bandgaps, which appear due to the ordered distribution of the resonators. Their use is based on the creation of resonance peaks to form additional nontransmission bands mainly in the low frequency regime, usually below the first Bragg frequency. The coupling of both gaps has been made in some cases, but it is not always so. In this work, using a periodic structure formed by Helmholtz resonators, we report the existence of interferences between the resonances and the Bragg bandgaps when they are working in nearby frequency ranges, so that they prevent the coupling of both gaps. We explain their physical principles and present possible solutions to mitigate them. To this end, we have developed numerical models based on the finite element method, and the results have been verified by means of accurate experimental results obtained under controlled conditions. Published under license by AIP Publishing.M.P.P.T. is grateful for the support of pre-doctoral Grant by the "Ministerio de Economia y Competitividad" of Spain through reference No. DI-15-08100.Peiró-Torres, MDP.; Castiñeira Ibáñez, S.; Redondo, J.; Sánchez Pérez, JV. (2019). Interferences in Locally Resonant Sonic Metamaterials Formed from Helmholtz Resonators. 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StateML + : From Graphical State Machine Models to Thread-Safe Ada Code

This paper presents the StateML+ tool aimed at designing state-machines and automatically generating thread-safe and multi-tasking modular Ada code from them, following a Model-Driven Engineering approach. The StateML+ meta-model is an extension of a previous version, and now it offers improved modeling capabilities, which include regions and macro-state definition. In this paper, a case study regarding the design of a robotic system will be used to demonstrate the benefits of the proposed approach.This research has been funded by the Spanish CICYT project MEDWSA (TIN2006-15175-C05-02) and the Regional Government of Murcia Seneca Program (02998-PI-05)