Ciencia y Tecnología

Entre la historia y la memoria: A 40 años del golpe de Estado en la Argentina

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Entre la historia y la memoria: A 40 años del golpe de Estado en la Argentina; Between history and memory: 40 years after the coup d’état in Argentina Crenzel, Emilio Ariel Este artículo historiza las etapas que ha recorrido, desde hace cuarenta años cuando se produjo el último golpe de Estado, la memoria social de la dictadura y el período de violencia política que recorrió la Argentina durante los años setenta del siglo XX y su figura emblemática, los desaparecidos. Luego de trazar un perfil general de las dimensiones cuantitativas y cualitativas de la violencia de Estado que atravesó el país, se presentan los diversos contextos políticos e institucionales que signaron cada etapa por el cual atravesó la memoria social sobre este proceso, los actores principales que intervinieron en las luchas por dotar de sentido a este pasado, y las claves narrativas e interpretativas que enarbolaron en esos enfrentamientos. El artículo propone y demuestra que la historia de la memoria no es resultado directo de la voluntad del poder y que, en el caso argentino, la memoria dominante ha sido y es producto de las iniciativas de verdad y justicia que propuso, en diversas coyunturas, el movimiento de derechos humanos. Esa perspectiva fue, luego, asumida por diversas conducciones del Estado. En cambio, las propuestas de olvido e impunidad, impulsadas por diversas conducciones estatales, fueron derrotadas por la hegemonía construida, en la esfera pública, por el movimiento de derechos humanos respecto a cómo tramitar las violaciones a los derechos humanos sucedidas en el país.; This article historicizes the stages, since the last coup d’état, of the construction of the social memory of the dictatorship and the period of political violence of 1970s Argentina and its emblematic figure, the disappeared. It begins with a general outline of the quantitative and qualitative dimensions of the state violence that affected the country during this process, and goes on to examine the various political and institutional contexts that marked each stage of the social memory of these processes, the actors engaged in the struggles to give meaning to that past, and the key narrative and interpretative strategies deployed in such confrontations. The article proposes and demonstrates that the history of the social memory of the human rights abuses is not a direct result of the will of the power and. On the contrary, in the case of Argentina, the dominant memory has been and is a product of the initiatives of truth and justice proposed, at various junctures, by the human rights movement. That perspective was then taken over by various state governments. Instead, the proposals of forgetfulness and impunity, launched by several state governments were defeated by the hegemony built, in the public scenario, by the human rights movement regarding how to deal with human rights violations occurred in the country.

La Juventud Universitaria Peronista en las memorias de la militancia estudiantil reformista y marxista de la UBA, 1973 - 1976

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La Juventud Universitaria Peronista en las memorias de la militancia estudiantil reformista y marxista de la UBA, 1973 - 1976; The Juventud Universitaria Peronista in the Memories of the Reformist and Marxist student militancy of UBA, 1973-1976 Millán, Mariano Ignacio Recorremos aquí las memorias de la militancia estudiantil reformista y marxista de la UBA acerca de la Juventud Universitaria Peronista entre 1973 y 1976. Analizamos 15 testimonios orales de activistas de diversas organizaciones, en los que encontramos cuatro tópicos centrales: la JUP era una fuerza de formación reciente, con escasa trayectoria y conocimiento del medio universitario; esta agrupación carecía de un proyecto universitario consistente; tenía relaciones conflictivas con sus aliados y, con el pasaje de Montoneros a la clandestinidad, se agudizaron las tensiones con las otras agrupaciones de la UBA.; In this paper we visit the memories of the reformist and marxist student activism of the UBA about the Juventud Universitaria Peronista between 1973 and 1976. We analyzed 15 oral testimonies of activists from various organizations and found four main topics: the JUP was a organization of recent formation, with little experience and knowledge of the university environment; this group lacked a consistent university project; the JUP had conflictive relations with its allies and, with the passage of Montoneros to clandestinity, the tensions with the other militant groupings of the UBA were exacerbated.

Molecular variability and genetic relationship among Brazilian strains of the sugarcane smut fungus

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Molecular variability and genetic relationship among Brazilian strains of the sugarcane smut fungus Benevenuto, Juliana; Longatto, Daniel P.; Reis, Gislaine V.; Mielnichuk, Natalia; Palhares, Alessandra C.; Carvalho, Giselle; Saito, Suzane; Quecine, Maria C.; Sanguino, Alvaro; Vieira, Maria Lucia C.; Camargo, Luis Eduardo A.; Creste, Silvana; Monteiro-Vitorello, Claudia B. Sporisorium scitamineum is the fungus that causes sugarcane smut disease. Despite of the importance of sugarcane for Brazilian agribusiness and the persistence of the pathogen in most cropping areas, genetic variation studies are still missing for Brazilian isolates. In this study, sets of isolates were analyzed using two molecular markers (AFLP and telRFLP) and ITS sequencing. Twenty-two whips were collected from symptomatic plants in cultivated sugarcane fields of Brazil. A total of 41 haploid strains of compatible mating types were selected from individual teliospores and used for molecular genetic analyses. telRFLP and ITS analyses were expanded to six Argentine isolates, where the sugarcane smut was first recorded in America. Genetic relationship among strains suggests the human-mediated dispersal of S. scitamineum within the Brazilian territory and between the two neighboring countries. Two genetically distinct groups were defined by the combined analysis of AFLP and telRFLP. The opposite mating-type strains derived from single teliospores were clustered together into these main groups, but had not always identical haplotypes. telRFLP markers analyzed over two generations of selfing and controlled outcrossing confirmed the potential for emergence of new variants and occurrence of recombination, which are relevant events for evolution of virulence and environmental adaptation.

Enrique Pezzoni: los casos literarios en la enseñanza de la teoría (1984-1986)

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Enrique Pezzoni: los casos literarios en la enseñanza de la teoría (1984-1986) Gerbaudo, Analía Isabel Este artículo gira sobre una marca de las clases de teoría literaria dictadas por Enrique Pezzoni en la carrera de letras de la Universidad de Buenos Aires entre 1984 y 1986: el trabajo con casos literarios. En primer lugar se realizan aclaraciones metodológicas respecto del análisis de clases desgrabadas. Luego se diferencian las lógicas del caso y del ejemplo literarios enmarcadas en el conjunto de sus operaciones didácticas mientras se hipotetiza sobre las tensiones del campo respecto de las que estas decisiones tomaban posición. Finalmente se recobra la relación entre teoría y literatura en su enseñanza a partir de cuentos de sus entonces alumnos, de colegas y de sus propias clases.; This article deals with one of the marks left by the literary theory lessons taught by Enrique Pezzoni in the Spanish course at Universidad de Buenos Aires between 1984 and 1986: the work on "literary cases”. First, some methodological clarifications regarding the transcribed lessons will be presented. Then, within the framework of Pezzoni’s didactics, the article will focus on the differences between the rationale of the literary "case" and the one of the "example”. At the same time, the link between the tensions within the literary field and Pezzoni’s didactics will be analyzed. Finally, the relationship between theory and literature in Pezzoni’s teaching is retraced in the testimonials from his former students, coworkers and his own lessons.

Micromamíferos del sitio arqueológico Cueva Galpón (Río Negro, Argentina): Aspectos tafonómicos y reconstrucción paleoambiental para el Holoceno Tardío en Norpatagonia oriental

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Micromamíferos del sitio arqueológico Cueva Galpón (Río Negro, Argentina): Aspectos tafonómicos y reconstrucción paleoambiental para el Holoceno Tardío en Norpatagonia oriental; Micromammals from the Cueva Galpón archaeological site (Río Negro, Argentina): Taphonomic issues and paleoenvironmental reconstruction during the late Holocene in Northeastern Patagonia Fernández, Fernando Julián; Teta, Pablo Vicente; Mange, Emiliano; Prates, Luciano Raúl; González Venanzi, Lucio; Pardiñas, Ulises Francisco J. Cueva Galpón se emplaza en la Sierra Colorada o Pailemán, en cercanías del borde oriental de la Altiplanicie del Somuncurá. Los fechados radiocarbónicos ubican el depósito arqueológico en el Holoceno tardío y lo convierten en un registro relevante para inferir la evolución ambiental del Desierto del Monte durante los últimos 3.000 años. En este trabajo se presenta el estudio de los restos de microma - míferos de Cueva Galpón (NISP = 4.594 y MNI = 566). El registro de egagrópilas preservadas y de restos óseos y dentarios con corrosión digestiva ligera indica que la acumulación fue producida mayoritariamente por Strigiformes. Se identificaron dos especies de marsupiales, siete de roedores sigmodontinos y al menos cuatro de roedores caviomorfos. Dos de los mamíferos registrados -Lestodelphys halli y Tympanoctomys kirchnerorum- se habrían extinguido regionalmente. La composición taxonómica del conjunto indica un ambiente general de Estepa Patagónica ecotonal con el Monte, posiblemente bajo un régimen de menores temperaturas y de precipitaciones levemente mayores que las actuales. Sin embargo, la ausencia en Cueva Galpón de elementos típicos de la Altiplanicie del Somuncurá, como roedores abrotriquinos o Euneomys petersoni, sugiere que las fluctuaciones ambientales del Holoceno tardío no habrían tenido la magnitud suficiente como para provocar cambios faunísticos significativos.; Cueva Galpón is located in the Sierra Colorada or Pailemán, close to the eastern edge of the Somuncurá plateau. Radiocarbon dates situate the archaeological deposit within the Late Holocene, thus the assemblage provides a relevant record for inferring environmental change in the montane desert during the last 3,000 years. For this article, micromammalian bone accumulations from the archaeological sequence (NISP = 4.594 and MNI = 566) were studied. Preserved owl pellets and skeletal specimens with light digestive corrosion, suggest that the micromammal remains were mainly deposited by strigiform birds. Two marsupials, seven sigmodontines, and at least four caviomorph species were recorded. Two of them –Lestodelphys halli and Tympanoctomys kirchnerorum- are now no longer present in the area. The taxonomic composition of the studied sample suggests an ecotonal environment between the Patagonian steppe and montane desert. It is possible that at the time, temperatures would have been lower and precipitation slightly higher than at present. However, the lack of faunal elements typical of the Somuncurá plateau, such as abrotrichines or Euneomys petersoni, indicates that Late Holocene environment

El Comité de Vigilance des Intellectuels Antifascistes, la prensa periódica y L'esprit des annés trente

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El Comité de Vigilance des Intellectuels Antifascistes, la prensa periódica y L'esprit des annés trente Pasolini, Ricardo Oscar El artículo examina el rol del Comité de Vigilancia de Intelectuales Antifascistas (C.V.I.A.) constituido en Francia en marzo de 1934. Propone la hipótesis de que la acción del C.V.I.A. fue parte de un clima mayor de renovación de la vida intelectual y política francesa de los años ‘30, y en él, ocupó un lugar importante en los debates referidos al surgimiento del fascismo; al pacifismo; a la tradición republicana y liberal; y al papel de los intelectuales en la lucha antifascista. Apoyado en el estudio de fuentes originales, se analiza la prensa periódica del período, tanto el boletín del C.V.I.A., Vigilance, como otras del campo más amplio del antifascismo cultural (Vigilance, Monde, Commune, Europe, Esprit, La Révolution Prolétariènne). Por último, se propone una reflexión historiográfica que vincula el estudio de los intelectuales con la Nueva Historia Política francesa.; The article examines the role of the Vigilance Committee of Antifascist Intellectuals (C.V.I.A.) incorporated in France in March 1934. It proposes the hypothesis that the action of C.V.I.A. was a part of a larger climate of renewal of French intellectual life and politics of the ‘30s. In that framework it occupies an important place in discussions relating to the rise of fascism; pacifism; the republican and liberal tradition; and the role of intellectuals in the antifascist struggle. It also analyzes the periodical press of cultural anti–fascism (Vigilance, Monde, Commune, Europe, Esprit, La Révolution Prolétariènne), and finally it proposes a historiographical reflection about the relationship between the study of intellectuals and New French Political History.

Adult neurogenesis beyond the niche: its potential for driving brain plasticity

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Adult neurogenesis beyond the niche: its potential for driving brain plasticity Sailor, Kurt A.; Schinder, Alejandro Fabián; Lledo, Pierre-Marie Adult neurogenesis emerges as a tremendous form of plasticity with the continuous addition and loss of neurons in the adult brain. It is unclear how preexisting adult circuits generated during development are capable of modifying existing connections to accommodate the thousands of new synapses formed and exchanged each day. Here we first make parallels with sensory deprivation studies and its ability to induce preexisting non-neurogenic adult circuits to undergo massive reorganization. We then review recent studies that show high structural and synaptic plasticity in circuits directly connected to adult-born neurons. Finally, we propose future directions in the field to decipher how host circuits can accommodate new neuron integration and to determine the impact of adult neurogenesis on global brain plasticity.

Complex Filling Dynamics in Mesoporous Thin Films

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Complex Filling Dynamics in Mesoporous Thin Films Mercuri, Magalí; Pierpaulli, Karina; Bellino, Martin Gonzalo; Berli, Claudio Luis Alberto The fluid-front dynamics resulting from the coexisting infiltration and evaporation phenomena in nanofluidic systems has been investigated. More precisely, water infiltration in both titania and silica mesoporous films was studied through a simple experiment: a sessile drop was deposited over the film and the advancement of the fluid front into the porous structure was optically followed and recorded in time. In the case of titania mesoporous films, capillary infiltration was arrested at a given distance, and a steady annular region of the wetted material was formed. A simple model that combines Lucas-Washburn infiltration and surface evaporation was derived, which appropriately describes the observed filling dynamics and the annulus width in dissimilar mesoporous morphologies. In the case of wormlike mesoporous morphologies, a remarkable phenomenon was found: instead of reaching a steady infiltration-evaporation balance, the fluid front exhibits an oscillating behavior. This complex filling dynamics opens interesting possibilities to study the unusual nanofluidic phenomena and to discover novel applications.

Effectiveness of Mexican oregano essential oil from the Dominican Republic (Lippia graveolens) against maize pests (Sitophilus zeamais and Fusarium verticillioides)

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Effectiveness of Mexican oregano essential oil from the Dominican Republic (Lippia graveolens) against maize pests (Sitophilus zeamais and Fusarium verticillioides); Efectividad del aceite esencial de orégano mexicano de República Dominicana (Lippia graveolens) contra plagas del maíz (Sitophilus zeamais y Fusarium verticillioides) Peschiutta, María Laura; Arena, Julieta Soledad; Ramirez Sanchez, A.; Gomez Torres, E.; Pizzolitto, Romina Paola; Merlo, Carolina; Zunino, María Paula; Omarini, Alejandra Beatriz; Dambolena, José Sebastián; Zygadlo, Julio Alberto The insecticidal and antifungal properties of Mexican oregano (Lippia graveolens) essential oil from the Dominican Republic were investigated under laboratory conditions against two main pests of stored grains: Sitophilus zeamais and Fusarium verticillioides. Although oregano essential oil at 600 μl/l air did not result in a significant mortality of S. zeamais after 24 hours of exposure by fumigation, this essential oil was a powerful acetylcholinesterase (AChE) inhibitor in vitro. One of the main components of oregano essential oil, p-cymene, presented fumigant toxicity and AChE inhibition activity against the maize weevil. The L. graveolens essential oil antifungal activity against F. verticillioides was evaluated at 50, 100 and 200 µl/l, and it was found that growth parameters were affected by the presence of oregano essential oil in the media, whereas FB1 production was not inhibited. The results demonstrate that oregano essential oil and p-cymene can be used as alternatives to synthetic pesticides against F. verticillioides and S. zeamais, respectively.; Se estudiaron en condiciones de laboratorio las propiedades insecticidas y fungicidas del aceite esencial de orégano mexicano (Lippia graveolens) de República Dominicana contra dos plagas principales de granos almacenados: Sitophilus zeamais y Fusarium verticillioides. Aunque el aceite esencial de orégano a 600 μl/l de aire no resultó en una mortalidad significativa de S. zeamais después de 24 horas de exposición a la fumigación, fue un potente inhibidor de la acetilcolinesterasa (AChE) in vitro. El p-cimeno, uno de los principales componentes del aceite esencial, presentó actividad fumigante y de inhibición de la AChE contra el gorgojo del maíz. Además se evaluó la actividad antifúngica frente a F. verticillioides a 50, 100 y 200 µl/l y se encontró que los parámetros de crecimiento del hongo fueron afectados por la presencia del aceite esencial de orégano en el medio, mientras que la producción de fumonisina B1 (FB1) no se inhibió. Los resultados demuestran que el aceite esencial de orégano y el p-cimeno se pueden usar como alternativas a los pesticidas sintéticos contra F. verticillioides y S. zeamais, respectivamente.

Bioprospecting for native microalgae as an alternative source of sugars for the production of bioethanol

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Bioprospecting for native microalgae as an alternative source of sugars for the production of bioethanol Sánchez Rizza, Lara; Sanz Smachetti, María Eugenia; Do Nascimento, Mauro; Salerno, Graciela Lidia; Curatti, Leonardo While the production of biofuels holds potential to contribute to energy security, concerns on food prices, land use, and carbon emissions have arisen from increased production of first-generation bioethanol. While second-generation bioethanol from lignocellulosic agricultural waste faces difficult-to-overcome technological barriers, renewed promise is held in microalgae biomass as an alternative feedstock. In this work we show the results of bioprospecting for microalgae native of South America for accumulation of carbohydrates under conditions of nitrogen deficiency, and constant light and temperature. After a preliminary analysis of seventeen strains, we selected strain SP2-3, because its biomass could be enriched in carbohydrates over 70% (w/w) on a dry biomass basis, and Desmodesmus sp. strain FG for its fermentable sugars productivity. After optimization of microalgae culture conditions, biomass hydrolysis and fermentation with baker´s yeast Saccharomyces cerevisiae, we demonstrated ethanol yields of up to 0.24 g ethanol·g of biomass− 1, and an ethanol concentration in the fermentation broth of 24 g ethanol·L of fermentation broth− 1, for up to 87.4% of the maximum theoretical value. These results contribute to support the potential of microalgae biomass as an alternative feedstock for bioethanol and the value of bioprospecting programs to identified candidate strains among natural biodiversity.

La arquitectura escolar de Martorell, Bohigas y Mackay: El modelo concentrado como oportunidad educativa

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La arquitectura escolar de Martorell, Bohigas y Mackay: El modelo concentrado como oportunidad educativa Durá Gúrpide, Isabel María En un momento de importante reformulación del edificio escolar, los arquitectos Martorell, Bohigas y Mackay definieron un modelo escolar de gran riqueza espacial, con una gran capacidad didáctica y especial énfasis social. Esto fue facilitado por su amplio conocimiento de experiencias destacadas, la colaboración con expertos en la enseñanza y su carácter crítico e inconformista. Sus escuelas fueron unos de los ejemplos más destacados realizados en los años 60 en España y consiguieron un importante reconocimiento internacional. El estudio de estos edificios permite no sólo poner en relieve su valor patrimonial sino también recuperarlos como referencia en la actualidad.

Una escuela pública de vanguardia: La escuela Timbaler del Bruc de Oriol Bohigas y Josep Martorell (Barcelona, 1957)

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Una escuela pública de vanguardia: La escuela Timbaler del Bruc de Oriol Bohigas y Josep Martorell (Barcelona, 1957); An innovative public school: Timbaler del Bruc School by Oriol Bohigas and Josep Martorell (Barcelona, 1957) Durá Gúrpide, Isabel María En un momento de intensa actividad en la reformulación de los espacios educativos, la escuela Timbaler del Bruc de Oriol Bohigas y Josep Martorell incorporó avances en arquitectura escolar de acuerdo a las nuevas necesidades pedagógicas y destacó como una obra ejemplar. Esta investigación sitúa la obra en su contexto, analiza en detalle el edificio a partir de su documentación original y el redibujado de sus planos e identifica sus principales valores. Si bien el proyecto partió de patrones establecidos, añadió aportaciones particulares que contribuyeron al desarrollo de la tipología escolar y se convirtió en una referencia para proyectos posteriores, tanto de sus autores como de otros profesionales. Este artículo no sólo se dirige a investigadores de la historia de la arquitectura sino también al conjunto de los arquitectos por la vigencia del valor de la obra como proyecto arquitectónico.

De políticas y subjetividades: nuevas estrategias de intervención en dispositivos de inclusión socio-educativa y laboral para jóvenes en argentina (2008-2016)

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De políticas y subjetividades: nuevas estrategias de intervención en dispositivos de inclusión socio-educativa y laboral para jóvenes en argentina (2008-2016); Policies and subjectivities: new strategies of intervention in devices including socio-educational and labor for youth in argentina (2008-2016) Ferraris, Sabrina Alejandra; Roberti, María Eugenia; Burgos, Edgardo Alejandro; Pozzer Pianalto, José Antonio El trabajo se propone aportar a los estudios que complejizan el análisis de las transiciones entre educación y trabajo. Así, se analizan dispositivos de inclusión socio-educativo y laboral que pretenden intervenir en la subjetividad de las personas que participan de ellos, en pos de mejorar las oportunidades de inclusión socio-laboral. Se presentan dos casos, con particularidades propias: el Programa Jóvenes con Más y Mejor Trabajo y un Centro de Formación Profesional, ambos radicados en dos municipios del conurbano bonaerense de la Argentina. Los casos se abordan desde una doble mirada: la institucional a través de la normativa que los regula y las voces de sus gestores, y el discurso de los propios sujetos participantes.; The paper aims to contribute to studies that complicate the analysis of transitions between education and work. Thus, are analyzed devices including socio-educational and job seeking to intervene in the subjectivity of people who participate in them, after improving opportunities for socio-labor inclusion. Two cases are presented, with particular features: The Youth Program for More and Better Jobs and a Vocational Training Center, both based in two municipalities of Argentina. The cases are approached from a double perspective: institutional through the regulations governing them and the voices of their managers, and the speech of participants subjects themselves.

Socioeconomic correlations and stratification in social-communication networks

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Socioeconomic correlations and stratification in social-communication networks Leo, Yannick; Fleury, Eric; Alvarez Hamelin, Jose Ignacio; Sarraute, Carlos; Karsai, Márton The uneven distribution of wealth and individual economic capacities are among the main forces, which shape modern societies and arguably bias the emerging social structures. However, the study of correlations between the social network and economic status of individuals is difficult due to the lack of large-scale multimodal data disclosing both the social ties and economic indicators of the same population. Here, we close this gap through the analysis of coupled datasets recording the mobile phone communications and bank transaction history of one million anonymized individuals living in a Latin American country. We show that wealth and debt are unevenly distributed among people in agreement with the Pareto principle; the observed social structure is strongly stratified, with people being better connected to others of their own socioeconomic class rather than to others of different classes; the social network appears to have assortative socioeconomic correlations and tightly connected ‘rich clubs’; and that individuals from the same class live closer to each other but commute further if they are wealthier. These results are based on a representative, society-large population, and empirically demonstrate some long-lasting hypotheses on socioeconomic correlations, which potentially lay behind social segregation, and induce differences in human mobility.

On the regularity of human mobility

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On the regularity of human mobility Mucelli Rezende Oliveira, Eduardo; Carneiro Viana, Aline; Sarraute, Carlos; Brea, Jorge Nicolás; Alvarez Hamelin, Jose Ignacio Understanding human mobility patterns is crucial to fields such as urban mobility and mobile network planning. For this purpose, we make use of large-scale datasets recording individuals spatio-temporal locations, from eight major world cities: Beijing, Tokyo, New York, Paris, San Francisco, London, Moscow and Mexico City. Our contributions are two-fold: first, we show significant similarities in people’s mobility habits regardless of the city and nature of the dataset. Second, we unveil three persistent traits present in an individual’s urban mobility: repetitiveness, preference for shortest-paths, and confinement. These characteristics uncover people’s tendency to revisit few favorite venues using the shortest-path available.

Relativistic Jets in Active Galactic Nuclei and Microquasars

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Relativistic Jets in Active Galactic Nuclei and Microquasars Romero, Gustavo Esteban; Boettcher, Markus; Markoff, Sera; Tavecchio, Fabrizio Collimated outflows (jets) appear to be a ubiquitous phenomenon associated with the accretion of material onto a compact object. Despite this ubiquity, many fundamental physics aspects of jets are still poorly understood and constrained. These include the mechanism of launching and accelerating jets, the connection between these processes and the nature of the accretion flow, and the role of magnetic fields; the physics responsible for the collimation of jets over tens of thousands to even millions of gravitational radii of the central accreting object; the matter content of jets; the location of the region(s) accelerating particles to TeV (possibly even PeV and EeV) energies (as evidenced by (Formula presented.)-ray emission observed from many jet sources) and the physical processes responsible for this particle acceleration; the radiative processes giving rise to the observed multi-wavelength emission; and the topology of magnetic fields and their role in the jet collimation and particle acceleration processes. This chapter reviews the main knowns and unknowns in our current understanding of relativistic jets, in the context of the main model ingredients for Galactic and extragalactic jet sources. It discusses aspects specific to active Galactic nuclei (especially blazars) and microquasars, and then presents a comparative discussion of similarities and differences between them.

Inhomogeneous diffusion and ergodicity breaking induced by global memory effects

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Inhomogeneous diffusion and ergodicity breaking induced by global memory effects Budini, Adrian Adolfo We introduce a class of discrete random walk model driven by global memory effects. At any time the right-left transitions depend on the whole previoushistory of the walker, being defined by an urn-like memory mechanism. The characteristic function is calculated in an exact way, which allows us todemonstrate that the ensemble of realizations is ballistic. Asymptoticallyeach realization is equivalent to that of a biased Markovian diffusion process with transition rates that strongly differs from one trajectory to another. Using this "inhomogeneous diffusion" feature the ergodic properties of the dynamics are analytically studied through the time-averaged moments. Even in the long time regime they remain random objects. While their average over realizations recover the corresponding ensemble averages, departure between time and ensemble averages is explicitly shown through their probability densities. For the density of the second time-averaged moment an ergodic limit and the limit of infinite lag times do not commutate. All these effects are induced by the memory effects. A generalized Einstein fluctuation-dissipation relation is also obtained for the time-averaged moments.

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