The kk-th derivatives of the immanant and the χ\chi-symmetric power of an operator

In recent papers, R. Bhatia, T. Jain and P. Grover obtained formulas for directional derivatives, of all orders, of the determinant, the permanent, the $m$-th compound map and the $m$-th induced power map. In this paper we generalize these results for immanants and for other symmetric powers of a matrix

Extremal dichotomy for uniformly hyperbolic systems

We consider the extreme value theory of a hyperbolic toral automorphism $T: \mathbb{T}^2 \to \mathbb{T}^2$ showing that if a H\"older observation $\phi$ which is a function of a Euclidean-type distance to a non-periodic point $\zeta$ is strictly maximized at $\zeta$ then the corresponding time series $\{\phi\circ T^i\}$ exhibits extreme value statistics corresponding to an iid sequence of random variables with the same distribution function as $\phi$ and with extremal index one. If however $\phi$ is strictly maximized at a periodic point $q$ then the corresponding time-series exhibits extreme value statistics corresponding to an iid sequence of random variables with the same distribution function as $\phi$ but with extremal index not equal to one. We give a formula for the extremal index (which depends upon the metric used and the period of $q$). These results imply that return times are Poisson to small balls centered at non-periodic points and compound Poisson for small balls centered at periodic points.Comment: 21 pages, 4 figure

INSERÇÃO DE PESSOAS COM DEFICIÊNCIA EM ORGANIZAÇÕES BRASILEIRAS: UM ESTUDO COM EMPRESAS SOCIALMENTE RESPONSÁVEIS

This research is under the Organizational Behavior Studies and it intended to investigate the relation between two basic aspects of management of diversity related to insertion of people with disabilities in organizationsconsidered social responsible: the way how the disability is seen by managers; and the suitability of the practices and work conditions. It was used quantitative methodology. A survey was carried out among 18 Brazilian enterprises. The results confirmed the theoretical purpose that several conceptions of disability existed and showed that enterprises have prioritized the changes at the work conditions more than the actions of sensitization and Human Resource practices which insure the insertion. Moreover, significant relations between conceptions of disability and suitability of the practices and work conditionswere examined, showing the importance of actions of Human Resource in the process of insertion

Stem cells and their applications in Dentistry: a Literature Review

Since stem cells were discovered, professionals in many different areas of healthcare have been using them as an important tool for fighting diseases, particularly diseases for which science has been unable to find cures. A stem cell is an undifferentiated unit with powerful self-renewal properties that is capable of organizing other cell types in the body. Many studies have shown the utility of embryonic or adult stem cells for forming teeth and for regeneration of bone and soft tissues. In view of the importance of the subject, this article provides a review of the literature on studies of stem cells and their potential applications in dentistry

Ultra-low noise, high-frame rate readout design for a 3D-stacked CMOS image sensor

Due to the switch from CCD to CMOS technology, CMOS based image sensors have become smaller, cheaper, faster, and have recently outclassed CCDs in terms of image quality. Apart from the extensive set of applications requiring image sensors, the next technological breakthrough in imaging would be to consolidate and completely shift the conventional CMOS image sensor technology to the 3D-stacked technology. Stacking is recent and an innovative technology in the imaging field, allowing multiple silicon tiers with different functions to be stacked on top of each other. The technology allows for an extreme parallelism of the pixel readout circuitry. Furthermore, the readout is placed underneath the pixel array on a 3D-stacked image sensor, and the parallelism of the readout can remain constant at any spatial resolution of the sensors, allowing extreme low noise and a high-frame rate (design) at virtually any sensor array resolution. The objective of this work is the design of ultra-low noise readout circuits meant for 3D-stacked image sensors, structured with parallel readout circuitries. The readout circuit’s key requirements are low noise, speed, low-area (for higher parallelism), and low power. A CMOS imaging review is presented through a short historical background, followed by the description of the motivation, the research goals, and the work contributions. The fundamentals of CMOS image sensors are addressed, as a part of highlighting the typical image sensor features, the essential building blocks, types of operation, as well as their physical characteristics and their evaluation metrics. Following up on this, the document pays attention to the readout circuit’s noise theory and the column converters theory, to identify possible pitfalls to obtain sub-electron noise imagers. Lastly, the fabricated test CIS device performances are reported along with conjectures and conclusions, ending this thesis with the 3D-stacked subject issues and the future work. A part of the developed research work is located in the Appendices.Devido à mudança da tecnologia CCD para CMOS, os sensores de imagem em CMOS tornam se mais pequenos, mais baratos, mais rápidos, e mais recentemente, ultrapassaram os sensores CCD no que respeita à qualidade de imagem. Para além do vasto conjunto de aplicações que requerem sensores de imagem, o próximo salto tecnológico no ramo dos sensores de imagem é o de mudar completamente da tecnologia de sensores de imagem CMOS convencional para a tecnologia “3D-stacked”. O empilhamento de chips é relativamente recente e é uma tecnologia inovadora no campo dos sensores de imagem, permitindo vários planos de silício com diferentes funções poderem ser empilhados uns sobre os outros. Esta tecnologia permite portanto, um paralelismo extremo na leitura dos sinais vindos da matriz de píxeis. Além disso, num sensor de imagem de planos de silício empilhados, os circuitos de leitura estão posicionados debaixo da matriz de píxeis, sendo que dessa forma, o paralelismo pode manter-se constante para qualquer resolução espacial, permitindo assim atingir um extremo baixo ruído e um alto debito de imagens, virtualmente para qualquer resolução desejada. O objetivo deste trabalho é o de desenhar circuitos de leitura de coluna de muito baixo ruído, planeados para serem empregues em sensores de imagem “3D-stacked” com estruturas altamente paralelizadas. Os requisitos chave para os circuitos de leitura são de baixo ruído, rapidez e pouca área utilizada, de forma a obter-se o melhor rácio. Uma breve revisão histórica dos sensores de imagem CMOS é apresentada, seguida da motivação, dos objetivos e das contribuições feitas. Os fundamentos dos sensores de imagem CMOS são também abordados para expor as suas características, os blocos essenciais, os tipos de operação, assim como as suas características físicas e suas métricas de avaliação. No seguimento disto, especial atenção é dada à teoria subjacente ao ruído inerente dos circuitos de leitura e dos conversores de coluna, servindo para identificar os possíveis aspetos que dificultem atingir a tão desejada performance de muito baixo ruído. Por fim, os resultados experimentais do sensor desenvolvido são apresentados junto com possíveis conjeturas e respetivas conclusões, terminando o documento com o assunto de empilhamento vertical de camadas de silício, junto com o possível trabalho futuro

O uso do DNA barcoding para identificar barbatanas de tubarão comercializadas ilegalmente no Brasil.

A demanda por barbatanas de tubarão tem aumentado nos últimos anos, estimulando o comércio ilegal e técnicas de captura predatórias que ameaçam a sobrevivência das populações naturais. As barbatanas de tubarão são normalmente removidas imediatamente após a captura e o corpo do animal é jogado de volta ao mar, o que impede a identifi cação morfológica da espécie. Quando a identifi cação morfológica está comprometida, a identifi cação genética pode ser usada para associar amostras desconhecidas com amostras de referência por meio da comparação de sequências de genes mitocondriais. Neste estudo, nós usamos sequências de 650 pares de base da subunidade I do gene citocromo c oxidase (COI) associadas com o Barcode of Life Database (BOLD) para identifi car uma carga de barbatanas de tubarão apreendidas pela Polícia Federal do Brasil em 2011. Nós conseguimos associar com sucesso 25 das 26 amostras encaminhadas para o laboratório com três espécies diferentes, sendo elas Prionace glauca, Isurus oxyrinchus e Sphyrna zygaena. Embora as três espécies não estejam atualmente protegidas pelas leis brasileiras, este estudo reforça a utilidade da ferramenta do DNA barcoding na casuística forense.The demand for shark fi ns has increased in the last years, stimulating the illegal trade and predatory capture techniques that threaten the survival of natural populations. Shark fi ns are usually removed immediately after the catch and the body of the animal is thrown back into the ocean, preventing the morphological identifi cation of the species. When morphological identifi cation is compromised, genetic identifi cation can be used to associate unknown samples to a reference sample by comparing sequences of mitochondrial genes. In this study we used sequences of 650 base pair of the subunit I of cytochrome c oxidase gene (COI) associated with the Barcode of Life Database (BOLD) to identify a cargo of shark fi ns seized by the Brazilian Federal Police in 2011. We have successfully matched 25 of 26 samples sent to the laboratory to three different species, Prionace glauca, Isurus oxyrinchus and Sphyrna zygaena. Although none of them are currently protected by Brazilian laws, this study reinforces the utility of DNA barcoding in forensic casework

On derivatives and norms of generalized matrix functions and respective symmetric powers

In recent papers, the authors obtained formulas for directional derivatives of all orders, of the immanant and of the m-th xi-symmetric tensor power of an operator and a matrix, when xi is a character of the full symmetric group. The operator norm of these derivatives was also calculated. In this paper, similar results are established for generalized matrix functions and for every symmetric tensor power