The interactive brain hypothesis

Enactive approaches foreground the role of interpersonal interaction in explanations of social understanding. This motivates, in combination with a recent interest in neuroscientific studies involving actual interactions, the question of how interactive processes relate to neural mechanisms involved in social understanding. We introduce the Interactive Brain Hypothesis (IBH) in order to help map the spectrum of possible relations between social interaction and neural processes. The hypothesis states that interactive experience and skills play enabling roles in both the development and current function of social brain mechanisms, even in cases where social understanding happens in the absence of immediate interaction. We examine the plausibility of this hypothesis against developmental and neurobiological evidence and contrast it with the widespread assumption that mindreading is crucial to all social cognition. We describe the elements of social interaction that bear most directly on this hypothesis and discuss the empirical possibilities open to social neuroscience. We propose that the link between coordination dynamics and social understanding can be best grasped by studying transitions between states of coordination. These transitions form part of the self-organization of interaction processes that characterize the dynamics of social engagement. The patterns and synergies of this self-organization help explain how individuals understand each other. Various possibilities for role-taking emerge during interaction, determining a spectrum of participation. This view contrasts sharply with the observational stance that has guided research in social neuroscience until recently. We also introduce the concept of readiness to interact to describe the practices and dispositions that are summoned in situations of social significance (even if not interactive). This latter idea links interactive factors to more classical observational scenarios.

Towards complex system design and management in the engineering domain – the smart grid challenge

This is an Author's Accepted Manuscript of an article published in “Emergence: Complexity and Organization”, 15 (2), pp. 14-22 (2013), copyright Taylor & Francis.

Design of antenna-coupled lumped-element titanium nitride KIDs for long-wavelength multi-band continuum imaging

Many applications in cosmology and astrophysics at millimeter wavelengths including CMB polarization, studies of galaxy clusters using the Sunyaev-Zeldovich effect (SZE), and studies of star formation at high redshift and in our local universe and our galaxy, require large-format arrays of millimeter-wave detectors. Feedhorn and phased-array antenna architectures for receiving mm-wave light present numerous advantages for control of systematics, for simultaneous coverage of both polarizations and/or multiple spectral bands, and for preserving the coherent nature of the incoming light. This enables the application of many traditional "RF" structures such as hybrids, switches, and lumped-element or microstrip band-defining filters.

Simultaneously, kinetic inductance detectors (KIDs) using high-resistivity materials like titanium nitride are an attractive sensor option for large-format arrays because they are highly multiplexable and because they can have sensitivities reaching the condition of background-limited detection. A KID is a LC resonator. Its inductance includes the geometric inductance and kinetic inductance of the inductor in the superconducting phase. A photon absorbed by the superconductor breaks a Cooper pair into normal-state electrons and perturbs its kinetic inductance, rendering it a detector of light. The responsivity of KID is given by the fractional frequency shift of the LC resonator per unit optical power.

However, coupling these types of optical reception elements to KIDs is a challenge because of the impedance mismatch between the microstrip transmission line exiting these architectures and the high resistivity of titanium nitride. Mitigating direct absorption of light through free space coupling to the inductor of KID is another challenge. We present a detailed titanium nitride KID design that addresses these challenges. The KID inductor is capacitively coupled to the microstrip in such a way as to form a lossy termination without creating an impedance mismatch. A parallel plate capacitor design mitigates direct absorption, uses hydrogenated amorphous silicon, and yields acceptable noise. We show that the optimized design can yield expected sensitivities very close to the fundamental limit for a long wavelength imager (LWCam) that covers six spectral bands from 90 to 400 GHz for SZE studies.

Excess phase (frequency) noise has been observed in KID and is very likely caused by two-level systems (TLS) in dielectric materials. The TLS hypothesis is supported by the measured dependence of the noise on resonator internal power and temperature. However, there is still a lack of a unified microscopic theory which can quantitatively model the properties of the TLS noise. In this thesis we derive the noise power spectral density due to the coupling of TLS with phonon bath based on an existing model and compare the theoretical predictions about power and temperature dependences with experimental data. We discuss the limitation of such a model and propose the direction for future study.

Mass spectrometry coupled to imaging techniques: The better the view the greater the challenge

These are definitively exciting times for membrane lipid researchers. Once considered just as the cell membrane building blocks, the important role these lipids play is steadily being acknowledged. The improvement occurred in mass spectrometry techniques (MS) allows the establishment of the precise lipid composition of biological extracts. However, to fully understand the biological function of each individual lipid species, we need to know its spatial distribution and dynamics. In the past 10 years, the field has experienced a profound revolution thanks to the development of MS-based techniques allowing lipid imaging (MSI). Images reveal and verify what many lipid researchers had already shown by different means, but none as convincing as an image: each cell type presents a specific lipid composition, which is highly sensitive to its physiological and pathological state. While these techniques will help to place membrane lipids in the position they deserve, they also open the black box containing all the unknown regulatory mechanisms accounting for such tailored lipid composition. Thus, these results urges to different disciplines to redefine their paradigm of study by including the complexity revealed by the MSI techniques.

Environmental taxes and the Double dividend hypothesis

In this End of Degree Dissertation I built a basic economic model, where two perfectly competitive markets interact, as a tool to understand, illustrate and evaluate environmentalfiscal reforms that have already been implemented or have been announced in many developed countries. Thus, in this dissertation I try to explain as simply as possible the theorical aspects of the “double dividend” hyphotesis and provide a numerical example with illustrative purpose.

Ética para além da moral: os apelos para o reconhecimento na escola

Este trabalho tem como proposta problematizar os atos de transgressões operados no cotidiano escolar sob os preceitos da ética e dos valores morais. Na interseção entre filosofia, psicanálise e educação tecemos nossa reflexão sobre o assunto, deflagrando alguns estudos pertinentes aos discursos conceituais, à questão da constituição dos sujeitos e das regras sociais, bem como de um fazer docente que questione os atos de transgressão no espaço da educação. Tal pesquisa se deve à inquietação provocada pelo contexto da sociedade hodierna, a qual, mergulhada numa grave crise de violência e de valores éticos, reavalia e revalida princípios e conceitos que, nitidamente, diante de uma conjuntura cada vez mais inclinada aos apelos do capital, vem deixando de nortear as relações sociais no decorrer dos anos. Neste contexto, o docente é cada vez mais convocado a desempenhar papéis que outrora pertenciam a outras categorias sociais, principalmente, com o avanço das escolas públicas de tempo integral. Aludimos assim a esta realidade, o desafio de engajar a ação educativa em demandas de eticidade. Aparar as arestas de um objeto de investigação tão amplo não é tarefa simples, portanto, consideraremos alguns recortes da constituição psíquica e social dos sujeitos. Analisando o lugar da ética na relação ensino/aprendizagem, no processo de formação escolar e no fazer docente, trabalhamos com o pressuposto de que a tensão sofrida cotidianamente pela criança e pelo adolescente, de um lado pelo tecido social, família, escola e Estado e do outro, pelo desejo de ser reconhecido nos grupos sociais, podem mesmo acirrar comportamentos inadequados e violentos na escola. Portanto, a postura adotada pelo educador frente aos conflitos internos e externos do aluno poderá, paradoxalmente, facilitar ou mesmo impedir uma dada má ação no seio da escola. Nossa finalidade é promover reflexões possíveis sobre as dimensões da ética nas relações manifestadas principalmente entre o docente e o aluno, acreditando que a existência de um espaço coletivo de discussão poderá contribuir para que ambos encontrem saídas próprias frente aos impasses que a questão ético/moral no âmbito educativo impõe.