Time-scale analysis non-local diffusion systems, applied to disease models

The objective of the present paper is to use the well known Ross-Macdonald models as a prototype, incorporating spatial movements, identifying different times scales and proving a singular perturbation result using a system of local and non-local diffusion. This results can be applied to the prototype model, where the vector has a fast dynamics, local in space, and the host has a slow dynamics, non-local in space

Vasectomy and gerbil ventral prostate: cell proliferation, apoptosis and estrom-epithelium interaction

Orientador: Wílson de Mello JuniorTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Doenças como o câncer e hiperplasia benigna de próstata estão relacionadas à falha no mecanismo de regulação do equilíbrio funcional entre os processos de proliferação celular e apoptose nas células prostáticas. O equilíbrio entre esses processos é controlado por níveis séricos de andrógenos e por fatores de crescimento. A vasectomia pode alterar tal equilíbrio por mecanismo ainda desconhecido. Durante os processos de carcinogênese da próstata, as interações parácrinas entre epitélio e estroma podem ser perturbadas, causando prejuízos tanto para epitélio quanto para musculatura lisa, e resultando em progressão para um estado anaplásico. Assim, o presente trabalho teve como objetivo avaliar a influência da vasectomia sobre os processos de proliferação e morte celular, bem como avaliar a estrutura e a ultra-estrutura da próstata ventral de gerbilo após vasectomia. Foram realizados estudos estruturais (Hematoxilina-eosina; tricrômico de Masson, reticulina de Gömöri e reação de Feulgen), ultra-estrutural (Microscopia eletrônica de transmissão) e imuno-histoquímicos (anti-Ki67, anti-PCNA e anti-Caspase-9) na próstata ventral de gerbilos. Os índices de proliferação celular prostática aumentaram nos gerbilos vasectomizados, porém os índices de apoptose não sofreram alteração pós-vasectomia. O volume relativo do epitélio aumentou, enquanto o volume relativo da luz diminuiu após vasectomia. Contudo, a morfologia geral da próstata ventral de gerbilo não se alterou. Portanto, a vasectomia não provoca alterações estruturais ou ultra-estruturais significativas na próstata ventral de gerbilo. Porém, promove um desequilíbrio entre os processos de proliferação celular e apoptose, em favor da proliferação celular do epitélio na próstata ventral de gerbiloAbstract: Diseases such as cancer and benign prostatic hyperplasia are related to the disruption in the mechanism of regulating the balance between both processes of cell proliferation and apoptosis in the prostatic cells. That balance is controlled by androgens and growth factors. Vasectomy might alter that balance by unknown mechanism yet. During process of prostatic carcinogenesis, the paracrine interaction between epithelium and stroma can be disrupted, causing damage to epithelium and smooth muscle cells. This results in progression to anaplastic state. Thus this study evaluates the influence of the vasectomy on both processes of cell proliferation and apoptosis in the epithelium of the gerbil ventral prostate, and evaluates structural and ultra-structural alterations induced by vasectomy on the gerbil ventral prostate. It was accomplished structural (Hematoxylineosin, Masson's trichrome, Gömöri¿s reticulin and Feulgen's reaction), ultra-structural (Transmission electron microscopy) and immunohistochemical (anti-Ki67, anti-PCNA e anti-Caspase-9) studies in the ventral prostate of the vasectomized and sham-operated gerbils. The indices of cell proliferation increased significantly in the vasectomized gerbil significantly after vasectomy. The epithelium relative volume increased, while the lumen relative volume decreased post-vasectomy. However the general morphology of the gerbil ventral prostate did not alter. Thus the vasectomy did not promote structural and ultrastructural alterations in the gerbil ventral prostate. But, cause imbalance between both processes of cell proliferation and apoptosis in favor cell proliferation in the epithelium of the gerbil ventral prostateDoutoradoAnatomiaDoutor em Biologia Celular e Estrutura

Solid immersion lens at the aplanatic condition for enhancing the spectral bandwidth of a waveguide grating coupler

We report a technique to substantially boost the spectral bandwidth of a conventional waveguide grating coupler by using a solid immersion cylindrical lens at the aplanatic condition to create a highly anamorphic beam and reach a much larger numerical aperture, thus enhancing the spectral bandwidth of a free-space propagating optical beam coupled into a single-mode planar integrated optical waveguide (IOW). Our experimental results show that the broadband IOW spectrometer thus created almost doubles (94% enhancement) the coupled spectral bandwidth of a conventional configuration. To exemplify the benefits made possible by the developed approach, we applied the technique to the broadband spectroscopic characterization of a protein submonolayer; our experimental data confirm the enhanced spectral bandwidth (around 380–nm) and illustrate the potentials of the developed technology. Besides the enhanced bandwidth, the broadband coupler of the single-mode IOW spectrometer described here is more robust and user-friendly than those previously reported in the literature and is expected to have an important impact on spectroscopic studies of surface-adsorbed molecular layers and surface phenomena

Stabilization of an arbitrary profile for an ensemble of half-spin systems

We consider the feedback stabilization of a variable profile for an ensemble of non interacting half spins described by the Bloch equations. We propose an explicit feedback law that stabilizes asymptotically the system around a given arbitrary target profile. The convergence proof is done when the target profile is entirely in the south hemisphere or in the north hemisphere of the Bloch sphere. The convergence holds for initial conditions in a H^1 neighborhood of this target profile. This convergence is shown for the weak H^1 topology. The proof relies on an adaptation of the LaSalle invariance principle to infinite dimensional systems. Numerical simulations illustrate the efficiency of these feedback laws, even for initial conditions far from the target profile.Comment: 6 pages, 2 figure

E-commerce and Business Case of a US E-commerce firm

What do we know as E-commerce and E-Business? Unique features of E-commerce. Types of E-commerce. History and feature of E-commerce. Why does E-commerce develop better in some places than in others? What make a current E-commerce success? Introduction of the US E-commerce firm studied. Bussiness case (customer, product, company and competition). Conclusions.Outgoin

Stabilization of photon-number states via single-photon corrections: a first convergence analysis under an ideal set-up

This paper presents a first mathematical convergence analysis of a Fock states feedback stabilization scheme via single-photon corrections. This measurement-based feedback has been developed and experimentally tested in 2012 by the cavity quantum electrodynamics group of Serge Haroche and Jean-Michel Raimond. Here, we consider the infinite-dimensional Markov model corresponding to the ideal set-up where detection errors and feedback delays have been disregarded. In this ideal context, we show that any goal Fock state can be stabilized by a Lyapunov-based feedback for any initial quantum state belonging to the dense subset of finite rank density operators with support in a finite photon-number sub-space. Closed-loop simulations illustrate the performance of the feedback law.Comment: 2 figures, extended version of the IEEE CDC2015 conference pape