The past decade has witnessed tremendous advances in the synthesis of polymers that contain elements from the main groups beyond those found in typical organic polymers. Unique properties that arise ...from dramatic differences in bonding and molecular geometry, electronic structure, and chemical reactivity, are exploited in diverse application fields. Herein we highlight recent advances in inorganic backbone polymers, discuss how Lewis acid/base functionalization of polymers results in unprecedented reactivity, and survey conjugated hybrids with unique electronic structures for sensor and device applications.
Polymers go main group! This Review shows how the incorporation of the full range of available main‐group elements into polymers leads to new functional hybrid materials with potential use in diverse application fields ranging from advanced elastomers, responsive gels, biodegradable materials, to organic electronics, imaging agents, sensors, and supported catalysts.
If personhood is the quality or condition of being an individual person, brainhood could name the quality or condition of being a brain. This ontological quality would define the `cerebral subject' ...that has, at least in industrialized and highly medicalized societies, gained numerous social inscriptions since the mid-20th century. This article explores the historical development of brainhood. It suggests that the brain is necessarily the location of the `modern self', and that, consequently, the cerebral subject is the anthropological figure inherent to modernity (at least insofar as modernity gives supreme value to the individual as autonomous agent of choice and initiative). It further argues that the ideology of brainhood impelled neuroscientific investigation much more than it resulted from it, and sketches how an expanding constellation of neurocultural discourses and practices embodies and sustains that ideology.
Performing Brains on Screen deals with film enactments and representations of the belief that human beings are essentially their brains, a belief that embodies one of the most influential modern ways ...of understanding the human. Films have performed brains in two chief ways: by turning physical brains into protagonists, as in the “brain movies" of the 1950, which show terrestrial or extra-terrestrial disembodied brains carrying out their evil intentions; or by giving brains that remain unseen inside someone’s head an explicitly major role, as in brain transplantation films or their successors since the 1980s, in which brain contents are transferred and manipulated by means of information technology. Through an analysis of filmic genres and particular movies, Performing Brains on Screen documents this neglected filmic universe, and demonstrates how the cinema has functioned as a cultural space where a core notion of the contemporary world has been rehearsed and problematized.
Este trabajo propone aportes teórico-metodológicos para el análisis de memes en internet publicados en páginas “jujeñas” de Facebook, entendiendo la circulación de memes como un fenómeno de la ...comunicación digital interactiva. En este sentido, consideramos posibles instancias de mediación del meme que implican competencias y usos posibles en su diseño y en su lectura. Esto, para finalmente proponer un abordaje que piensa Facebook como plataforma, en tanto sus posibilidades de interacción significativa.
This study explores for the first time the shape, volume, and configuration of nasal cavity structures of the endangered Patagonian huemul deer via computed tomography (CT). Three-dimensional (3D) ...reconstructions derived from data sets obtained from five Patagonian huemul deer skulls were analyzed. Using semiautomatic segmentation, 3D models were created of all the sinus compartments and nasal conchae. Volumetric measurements were taken of seven sinus compartments. The Patagonian huemul deer has a wide, large nasal cavity, with an osseous nasal aperture typical of cervids and a choana with characteristics that differentiate it from the pudu and roe deer. It also has six nasal meatuses and three nasal conchae, with the ventral nasal concha having the greatest volume and surface, which given its extension ensures a greater ability to humidify and heat the air. Further analysis showed the complex system of paranasal sinuses to be characterized by a rostroventral and interconnected group, where communication with the nasal cavity is common through the nasomaxillary opening, and a caudodorsal group that communicates with the nasal cavity through openings in the nasal meatuses. Our study of the endangered Patagonian huemul deer documents an intricate, and in some nasal cavity structures, unique morphological construction which may predispose it to higher rates of sinonasal afflictions due largely to its nasal complex anatomy, thus affecting its high cultural value.
Classical Lewis pairs (LPs) between unhindered electron-poor Lewis acids (LAs) and electron-rich Lewis bases (LBs) present an overlooked motif with tremendous potential as dynamic cross-links in ...transient polymer networks (TPNs) for self-healing and stimuli-responsive applications. We demonstrate that simple and intuitive matching of weak/strong organoborane LA and amine LB pairs offers access to a large set of binding equilibrium constants, K eq, that span ∼6 orders and dissociation rate constants, k diss, that span ∼7 orders of magnitude. The implementation in polystyrene (PS)/polydimethylsiloxane (PDMS) blends results in dynamically cross-linked networks with bulk thermomechanical properties that are directly correlated with the strength and kinetic parameters for the LP interactions. The LP dynamic cross-link design is highly versatile and broadly applicable to different polymer architectures as demonstrated in the formation of reprocessable elastomers from Lewis base-decorated high molecular weight PDMS in combination with Lewis acid-decorated PS when reinforced with fumed silica as a filler.
Although widely used in catalysis, the multistep syntheses and high loadings typically employed are limiting broader implementation of highly active tailor-made arylborane Lewis acids and Lewis ...pairs. Attempts at developing recyclable systems have thus far met with limited success, as general and versatile platforms are yet to be developed. We demonstrate a novel approach that is based on the excellent control and functional group tolerance of ring-opening metathesis polymerization (ROMP). The ROMP of highly Lewis acidic borane-functionalized phenylnorbornenes afforded both a soluble linear copolymer and a cross-linked organogel. The polymers proved highly efficient as recyclable catalysts in the reductive N-alkylation of arylamines under mild conditions and at exceptionally low catalyst loadings. The modular design presented herein can be readily adapted to other finely tuned triarylboranes, enabling wide applications of ROMP-borane polymers as well-defined supported organocatalysts.
Tactile rendering has been implemented in digital musical instruments (DMIs) to offer the musician haptic feedback that enhances his/her music playing experience. Recently, this implementation has ...expanded to the development of sensory substitution systems known as haptic music players (HMPs) to give the opportunity of experiencing music through touch to the hearing impaired. These devices may also be conceived as vibrotactile music players to enrich music listening activities. In this review, technology and methods to render musical information by means of vibrotactile stimuli are systematically studied. The methodology used to find out relevant literature is first outlined, and a preliminary classification of musical haptics is proposed. A comparison between different technologies and methods for vibrotactile rendering is performed to later organize the information according to the type of HMP. Limitations and advantages are highlighted to find out opportunities for future research. Likewise, methods for music audio-tactile rendering (ATR) are analyzed and, finally, strategies to compose for the sense of touch are summarized. This review is intended for researchers in the fields of haptics, assistive technologies, music, psychology, and human–computer interaction as well as artists that may make use of it as a reference to develop upcoming research on HMPs and ATR.
Desde meados do século XX, numerosos discursos e práticas, dentro e fora das disciplinas científicas e filosóficas, têm apresentado o desenvolvimento da noção de ser humano como um ‘sujeito ...cerebral’. O cérebro é concebido como a única parte do corpo que devemos possuir, e que deve ser nossa, para que sejamos nós mesmos. Já que a personalidade é a qualidade ou condição para ser considerado um indivíduo, a ‘cerebralidade’ é, dessa forma, a qualidade ou condição de ser um cérebro. Esta propriedade define o sujeito cerebral. A antropologia da ‘cerebralidade’ pode parecer uma conseqüência natural do progresso das neurociências – mas procede de desenvolvimentos das filosofias da matéria e da identidade pessoal do século XVII. As neurociências confirmam e reforçam esta perspectiva. O autor delineia a narrativa histórica relacionada ao desenvolvimento do sujeito cerebral assim como alguns temas contemporâneos que surgem a partir das neurociências.
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