Light emission from gold and silver thin films in a scanning tunneling microscope: role of contamination and interpretation of grain structure in photon maps

Scanning tunnelling microscope (STM) tip-induced light emission from Au and Ag has been studied. Thin film samples similar to100nm thick were prepared by thermal evaporation at 0.5nm/s onto a room-temperature glass substrate to produce grains of 20-50nm in lateral dimension at the surface. Light emission from the samples in the STM was quasi-simultaneously recorded with the topography, at 1.8V tip bias and 3-40nA current, alternating pixel by pixel at the same bias. Typically, a surface scan range of 150 nm x 150 nm was surveyed. Au, W and PtIr tips were used.

Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes.

Research in autophagy continues to accelerate,(1) and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.(2,3) There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.

Sleepwalking certainties: agency, aesthetics, and incapacity in W.G. Sebald’s 'Austerlitz' and Hermann Broch’s 'The Sleepwalkers'

When we first encounter the narrator of Austerlitz, he is wandering around the unfamiliar town of Antwerp with, he tells us, “unsicheren Schritten” (1; 9). As well as reflecting the unfamiliarity of the locale, these “uncertain steps” evince a proud modesty characteristic of the classic Sebaldian narrator, a wanderer who discreetly relays the stories of the people and places he is privileged to encounter. Although Sebald does not use the phrase, steps of this sort, unpurposed yet unerring, are made with what is commonly known in German as somnambule Sicherheit: the legendary surefootedness of the sleepwalker. The convergence of sleepwalking and certainty in a single phrase poses an interesting challenge to one of the central tenets of the English-language canonization of Sebald, for his writing has been most highly valued for its ability to move the reader through apparent certainties towards a salutary uncertainty. But somnambule Sicherheit also presents the possibility that the current may be reversed, that narrative may move under cover of uncertainty towards certainty. That Sebald criticism has not been more troubled by this possibility is in no small part due to the fact that it tends to deploy the notion of sleepwalking with a minimum of reflection on its theoretical ramifications. To evoke some of the complexities of this matter, I first offer a brief cultural history of sleepwalking, as well as a brief account of the topic of uncertainty in Sebald criticism. Most of my argument, however, involves an extended comparative analysis of sleepwalking in Sebald's Austerlitz and Hermann Broch's 1933 trilogy The Sleepwalkers. Although these writers have not previously been the object of any sustained comparison, sleepwalking in Broch's novels illuminates much that is left implicit on the topic in Sebald's fiction and points toward some difficult questions regarding the role of aesthetics and agency in Sebald's work.

Description and interpretation of Cenozoic vertebrate ichnofossils in Rio Grande do Sul State, Brazil

In the neighborhood of the city of Boqueirão do Leão (State of Rio Grande do Sul, Brazil) a set of three big-sized tunnels has been found. One of the tunnels is only partially filled with sand and accessible along its entire length. It is horizontal, slightly sinuous, 36 m long, up to 4.2 m wide and up to 2.0 m high. The surface morphology of the walls is composed of anthropogenic marks, speleothems, black incrustations and traces like digging scratches and smoothed surfaces. The 2nd tunnel has its entrance blocked by sand and sandstone cobbles, but the end of the tunnel is only partially clogged and therefore accessible. This accessible portion is 12 m long, 3 m wide and 1.5 m high. The 3rd tunnel is completely filled and collapsed and is nowadays only indicated by concave roof features at its end. The general features of the tunnel system and the analysis of the surface morphology of the walls of the accessible portions permit to conclude that the tunnels were produced by ground sloths of the Cenozoic South American megafauna. The size of the tunnels suggests that its excavation was gradually carried out by successive generations of sloth herds, and not by a single individual animal. The primary function of the tunnels probably was not protection from predators, which had easy access to structures of this size, but to shelter during a drier climate. However, it is not yet possible to relate the tunnels to a specific ground sloth genus, a task that depends on the discovery of better-preserved tunnel systems. © 2013 by the Sociedade Brasileira de Paleontologia.

Guidelines for the use and interpretation of assays for monitoring autophagy

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes

Research in autophagy continues to accelerate,(1) and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.(2,3) There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.

Guidelines for the use and interpretation of assays for monitoring cell death in higher eukaryotes

Cell death is essential for a plethora of physiological processes, and its deregulation characterizes numerous human diseases. Thus, the in-depth investigation of cell death and its mechanisms constitutes a formidable challenge for fundamental and applied biomedical research, and has tremendous implications for the development of novel therapeutic strategies. It is, therefore, of utmost importance to standardize the experimental procedures that identify dying and dead cells in cell cultures and/or in tissues, from model organisms and/or humans, in healthy and/or pathological scenarios. Thus far, dozens of methods have been proposed to quantify cell death-related parameters. However, no guidelines exist regarding their use and interpretation, and nobody has thoroughly annotated the experimental settings for which each of these techniques is most appropriate. Here, we provide a nonexhaustive comparison of methods to detect cell death with apoptotic or nonapoptotic morphologies, their advantages and pitfalls. These guidelines are intended for investigators who study cell death, as well as for reviewers who need to constructively critique scientific reports that deal with cellular demise. Given the difficulties in determining the exact number of cells that have passed the point-of-no-return of the signaling cascades leading to cell death, we emphasize the importance of performing multiple, methodologically unrelated assays to quantify dying and dead cells.

La crítica y sus (in)certezas : Hacia una articulación de las teorías sociológicas de Horkheimer, Adorno y Bourdieu: teoría crítica, sociología reflexiva y sus potencialidades para una crítica del presente

La problemática a ser investigada se articula en torno al interrogante acerca de cómo elaborar una perspectiva crítica de los mecanismos de reproducción de la desigualdad social de nuestro presente, que no se asiente en un referente de certeza producto de algún tipo de fundamento normativo. Con este fin se estudiarán, centralmente, dos registros de la teoría sociológica del siglo XX: la teoría crítica de la sociedad producida por Horkheimer y Adorno, y la sociología reflexiva de P. Bourdieu. Buscando, en la tensión entre ambas, los elementos conceptuales que permitan dar cuenta del interrogante planteado. De allí que esta investigación se enfoque en la forma en que estos autores construyen sus respectivas críticas culturales, estudiando los "fundamentos metódico-conceptuales" de las mismas. Así la puesta en diálogo de las teorías sociológicas alemana y francesa será la vía por la cual hacernos de los hilos conceptuales con los que elaborar la trama de una teoría crítica de nuestro presente que no se funde en un referente de certeza. Pero que aun así sea capaz de abordar diversos materiales culturales para, a través de esa crítica cultural, aprehender los mecanismos que reproducen la forma en que la sociedad se da un orden a sí misma, la estructuración de lo político. En pos de luchar por la desarticulación de aquellas estructuras funcionales a la reproducción de las relaciones de dominación establecidas.

La crítica y sus (in)certezas : Hacia una articulación de las teorías sociológicas de Horkheimer, Adorno y Bourdieu: teoría crítica, sociología reflexiva y sus potencialidades para una crítica del presente

La problemática a ser investigada se articula en torno al interrogante acerca de cómo elaborar una perspectiva crítica de los mecanismos de reproducción de la desigualdad social de nuestro presente, que no se asiente en un referente de certeza producto de algún tipo de fundamento normativo. Con este fin se estudiarán, centralmente, dos registros de la teoría sociológica del siglo XX: la teoría crítica de la sociedad producida por Horkheimer y Adorno, y la sociología reflexiva de P. Bourdieu. Buscando, en la tensión entre ambas, los elementos conceptuales que permitan dar cuenta del interrogante planteado. De allí que esta investigación se enfoque en la forma en que estos autores construyen sus respectivas críticas culturales, estudiando los "fundamentos metódico-conceptuales" de las mismas. Así la puesta en diálogo de las teorías sociológicas alemana y francesa será la vía por la cual hacernos de los hilos conceptuales con los que elaborar la trama de una teoría crítica de nuestro presente que no se funde en un referente de certeza. Pero que aun así sea capaz de abordar diversos materiales culturales para, a través de esa crítica cultural, aprehender los mecanismos que reproducen la forma en que la sociedad se da un orden a sí misma, la estructuración de lo político. En pos de luchar por la desarticulación de aquellas estructuras funcionales a la reproducción de las relaciones de dominación establecidas.

La crítica y sus (in)certezas : Hacia una articulación de las teorías sociológicas de Horkheimer, Adorno y Bourdieu: teoría crítica, sociología reflexiva y sus potencialidades para una crítica del presente

La problemática a ser investigada se articula en torno al interrogante acerca de cómo elaborar una perspectiva crítica de los mecanismos de reproducción de la desigualdad social de nuestro presente, que no se asiente en un referente de certeza producto de algún tipo de fundamento normativo. Con este fin se estudiarán, centralmente, dos registros de la teoría sociológica del siglo XX: la teoría crítica de la sociedad producida por Horkheimer y Adorno, y la sociología reflexiva de P. Bourdieu. Buscando, en la tensión entre ambas, los elementos conceptuales que permitan dar cuenta del interrogante planteado. De allí que esta investigación se enfoque en la forma en que estos autores construyen sus respectivas críticas culturales, estudiando los "fundamentos metódico-conceptuales" de las mismas. Así la puesta en diálogo de las teorías sociológicas alemana y francesa será la vía por la cual hacernos de los hilos conceptuales con los que elaborar la trama de una teoría crítica de nuestro presente que no se funde en un referente de certeza. Pero que aun así sea capaz de abordar diversos materiales culturales para, a través de esa crítica cultural, aprehender los mecanismos que reproducen la forma en que la sociedad se da un orden a sí misma, la estructuración de lo político. En pos de luchar por la desarticulación de aquellas estructuras funcionales a la reproducción de las relaciones de dominación establecidas.

OSIRIS observations of meter-sized exposures of H2O ice at the surface of 67P/Churyumov-Gerasimenko and interpretation using laboratory experiments

Since OSIRIS started acquiring high-resolution observations of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko, over one hundred meter-sized bright spots have been identified in numerous types of geomorphologic regions, but mostly located in areas receiving low insolation. The bright spots are either clustered, in debris fields close to decameter-high cliffs, or isolated without structural relation to the surrounding terrain. They can be up to ten times brighter than the average surface of the comet at visible wavelengths and display a significantly bluer spectrum. They do not exhibit significant changes over a period of a few weeks. All these observations are consistent with exposure of water ice at the surface of boulders produced by dislocation of the weakly consolidated layers that cover large areas of the nucleus. Laboratory experiments show that under simulated comet surface conditions, analog samples acquire a vertical stratification with an uppermost porous mantle of refractory dust overlaying a layer of hard ice formed by recondensation or sintering under the insulating dust mantle. The evolution of the visible spectrophotometric properties of samples during sublimation is consistent with the contrasts of brightness and color seen at the surface of the nucleus. Clustered bright spots are formed by the collapse of overhangs that is triggered by mass wasting of deeper layers. Isolated spots might be the result of the emission of boulders at low velocity that are redepositioned in other regions.

O PROCESSO FORMATIVO E A ATUAÇÃO DO ARTE-EDUCADOR: POSSIBILIDADES E CONTRIBUIÇÕES DA TEORIA IRONISTA

A presente pesquisa visa a revisão bibliográfica do processo formativo e, ao mesmo tempo, a investigação e problematização da atuação contemporânea do educador ironista na Educação. O autor Imanol Aguirre, concebe este título ao educador que seja provocativo, inteirado e propositor de experiências estéticas frente às complexidades contemporâneas, amalgamadas num tecido histórico-social caracterizado pelo trânsito da pluralidade, dos imaginários, da construção de identidade e da mobilidade social. O ironista atua dialogicamente “in loco” criando respostas às variadas demandas com os seus educandos. A fomentação da crítica, a mobilização da dúvida e da ironia, a conexão dos territórios das competências e habilidades, são os objetivos pelos quais o educador ironista intenciona um cenário educacional mais efetivo e emancipador ante as reais necessidades contemporâneas.

A MULHER ALÉM DO BEM E DO MAL: Malévola e a representação cinematográfica do feminino integrado

Estudo sobre as construções simbólicas e identitárias da mulher presentes na narrativa e na estrutura das personagens femininas do filme Malévola (2014) – produção dos estúdios Disney (EUA). A narrativa é inspirada no conto de fadas “A Bela Adormecida do Bosque” e distingue-se pela perspectiva feminina, modificando as possibilidades de interpretação, além de possibilitar a quebra do paradigma dicotômico relacionado ao Bem e ao Mal. A pesquisa tem por objetivo estudar a evolução das construções imaginárias da mulher no cinema e traçar paralelos entre as características arquetípicas das personagens de Malévola em relação à identidade da mulher na contemporaneidade. Para tal, será tomado como referencial teórico os estudos do imaginário social, com as obras de Gilbert Durand, Edgar Morin e, em especial, Michel Maffesoli; conceitos da psicanálise a partir dos trabalhos de C.G. Jung, Erich Neumann, Marie-Louise Von Franz e Clarissa Pinkola Estés; as teorias de Stuart Hall, Laura Mulvey e Gilles Lipovetsky relacionadas aos estudos culturais com ênfase em gênero; e também o ecofeminismo através dos trabalhos de autoras como Vandana Shiva e Maria Mies. Nosso referencial teórico-metodológico é a Hermenêutica de Profundidade (HP) visando à interpretação da estrutura simbólica de nosso objeto. Resultam desta pesquisa a verificação de um processo de saturação de padrões identitários e simbólicos provindos da modernidade e a evolução de novas dinâmicas nas narrativas presentes nas mídias e na comunicação