Dynamical behaviour on the parameter space: new populational growth models proportional to beta densities

We present new populational growth models, generalized logistic models which are proportional to beta densities with shape parameters p and 2, where p > 1, with Malthusian parameter r. The complex dynamical behaviour of these models is investigated in the parameter space (r, p), in terms of topological entropy, using explicit methods, when the Malthusian parameter r increases. This parameter space is split into different regions, according to the chaotic behaviour of the models.

The importance of the program for the promotion of physical activity in perceived fatigue in people with multiple sclerosis

The aims of the study is to examine for intervention program of physical activity in the perception of fatigue, in patients with multiple sclerosis.

Influence of growth temperature and carrier flux on the structure and transport properties of highly oriented CrO2 on Al2O3 (0001)

In this work we report on the structure and magnetic and electrical transport properties of CrO2 films deposited onto (0001) sapphire by atmospheric pressure (AP)CVD from a CrO3 precursor. Films are grown within a broad range of deposition temperatures, from 320 to 410 degrees C, and oxygen carrier gas flow rates of 50-500 seem, showing that it is viable to grow highly oriented a-axis CrO2 films at temperatures as low as 330 degrees C i.e., 60-70 degrees C lower than is reported in published data for the same chemical system. Depending on the experimental conditions, growth kinetic regimes dominated either by surface reaction or by mass-transport mechanisms are identified. The growth of a Cr2O3 interfacial layer as an intrinsic feature of the deposition process is studied and discussed. Films synthesized at 330 degrees C keep the same high quality magnetic and transport properties as those deposited at higher temperatures.

The (well) informed piano : internalization and growth process

The subject matter of this book is about piano methodology, including technical, musical, artistic, ethical and philosophical issues and reflections. The purpose of this work is to share a personal professional experience insight in the field of piano performance. This text assumes a certain continuity to the major contributions of artists like Ludwig Deppe, Tobias Matthay, Grigory Kogan, Heinrich Neuhaus and George Kochevitsky. At the same time, it tries to integrate and complement this selected literature, bringing new ideas and hints to specific professional issues.

Seq����ncia de drogas consumidas por usu��rios de crack e fatores interferentes

OBJETIVO: Identificar, entre usu��rios de crack, uma progress��o no uso de drogas e seus fatores interferentes. M��TODOS: Utilizou-se metodologia qualitativa para uma investiga����o mais profunda, considerando o ponto de vista que o entrevistado tem do fen��meno. Foram aplicados entrevistas de longa dura����o e question��rios semi-estruturados. Foi delineada uma amostra intencional, e uma amostragem com crit��rios foi conseguida. Para atingir a satura����o te��rica, foram entrevistados 31 usu��rios ou ex-usu��rios de crack. RESULTADOS: Foram detectadas duas fases distintas de uso de drogas. A primeira, com drogas l��citas, sendo o cigarro e o ��lcool as mais citadas pela amostra. Parentes e amigos dos entrevistados foram os incentivadores do consumo, e o motivo alegado para o uso dessas subst��ncias foi a necessidade de autoconfian��a. A idade precoce do consumo e o uso pesado de uma ou ambas as drogas foram determinantes para o in��cio de uma escalada de drogas il��citas. A maconha foi a primeira droga dessa segunda fase. Uma postura mais ativa na busca da droga como fonte de prazer passou a ser o motivo do consumo. CONCLUS��ES: O estudo revela que a identifica����o de uma seq����ncia de drogas parece estar mais associada a fatores externos (press��es de grupo, influ��ncia do tr��fico etc.) do que �� prefer��ncia do usu��rio. Foram identificadas duas progress��es diferentes: entre os mais jovens (=30 anos), cuja a escalada come��ou com o cigarro e/ou ��lcool e passou pela maconha e coca��na aspirada at�� o uso de crack; e os mais velhos (>30 anos), que iniciaram o uso de drogas pelo cigarro e/ou ��lcool, seguido de maconha, medicamentos endovenosos, coca��na aspirada, coca��na endovenosa e, por fim, crack.

Dynamical analysis in growth models: Blumberg���s equation

We present a new dynamical approach to the Blumberg's equation, a family of unimodal maps. These maps are proportional to Beta(p, q) probability densities functions. Using the symmetry of the Beta(p, q) distribution and symbolic dynamics techniques, a new concept of mirror symmetry is defined for this family of maps. The kneading theory is used to analyze the effect of such symmetry in the presented models. The main result proves that two mirror symmetric unimodal maps have the same topological entropy. Different population dynamics regimes are identified, when the intrinsic growth rate is modified: extinctions, stabilities, bifurcations, chaos and Allee effect. To illustrate our results, we present a numerical analysis, where are demonstrated: monotonicity of the topological entropy with the variation of the intrinsic growth rate, existence of isentropic sets in the parameters space and mirror symmetry.

Lack of association between iron status at birth and growth of preterm infants

OBJECTIVE: To assess the association between iron status at birth and growth of preterm infants. METHODS: Ninety-five premature babies (26 to 36 weeks of gestational age) born from July 2000 to May 2001 in a public hospital in Rio de Janeiro, Southeastern Brazil, were followed up for six months, corrected by gestational age. Iron measurements at birth were available for 82 mothers and 78 children: hemoglobin, hematocrit, mean corpuscular volume and plasma iron. All children received free doses of iron supplement (2 mg/kg/day) during the follow-up period and up to two years of age. Multivariate linear regression analyses with repeated measurements were performed to assess factors associated to linear growth. RESULTS: Growth was more pronounced up to 40 weeks of gestational age, increasing about 1.0 cm/week and then slowing down to 0.75 cm/week. The multivariate analysis showed growth was positively associated with birth weight (0.4 cm/100 g; p<0.001) and negatively associated with gestational age at birth (-0.5 cm/week; p<0.001). There was no association between cord iron and mother iron measurements and growth (p>0.60 for all measures). Only two children had anemia at birth, whereas 43.9% of mothers were anemic (hemoglobin <11 g/dl). Also, there was no correlation between anemia indicators of mothers and children at birth (r<0.15; p>0.20). CONCLUSIONS: Maternal anemia was not associated with anemia in preterm infants and iron status of mothers and children at birth was not associated with short-term growth of preterm infants.

An Extension of Gompertzian Growth Dynamics Weibull and Frechet Models

In this work a new probabilistic and dynamical approach to an extension of the Gompertz law is proposed. A generalized family of probability density functions, designated by Beta* (p, q), which is proportional to the right hand side of the Tsoularis-Wallace model, is studied. In particular, for p = 2, the investigation is extended to the extreme value models of Weibull and Frechet type. These models, described by differential equations, are proportional to the hyper-Gompertz growth model. It is proved that the Beta* (2, q) densities are a power of betas mixture, and that its dynamics are determined by a non-linear coupling of probabilities. The dynamical analysis is performed using techniques of symbolic dynamics and the system complexity is measured using topological entropy. Generally, the natural history of a malignant tumour is reflected through bifurcation diagrams, in which are identified regions of regression, stability, bifurcation, chaos and terminus.

Topological Complexity and Predictability in the Dynamics of a Tumor Growth Model with Shilnikov's Chaos

Dynamical systems modeling tumor growth have been investigated to determine the dynamics between tumor and healthy cells. Recent theoretical investigations indicate that these interactions may lead to different dynamical outcomes, in particular to homoclinic chaos. In the present study, we analyze both topological and dynamical properties of a recently characterized chaotic attractor governing the dynamics of tumor cells interacting with healthy tissue cells and effector cells of the immune system. By using the theory of symbolic dynamics, we first characterize the topological entropy and the parameter space ordering of kneading sequences from one-dimensional iterated maps identified in the dynamics, focusing on the effects of inactivation interactions between both effector and tumor cells. The previous analyses are complemented with the computation of the spectrum of Lyapunov exponents, the fractal dimension and the predictability of the chaotic attractors. Our results show that the inactivation rate of effector cells by the tumor cells has an important effect on the dynamics of the system. The increase of effector cells inactivation involves an inverse Feigenbaum (i.e. period-halving bifurcation) scenario, which results in the stabilization of the dynamics and in an increase of dynamics predictability. Our analyses also reveal that, at low inactivation rates of effector cells, tumor cells undergo strong, chaotic fluctuations, with the dynamics being highly unpredictable. Our findings are discussed in the context of tumor cells potential viability.

Avalia����o da integridade estrutural de uma pr��tese cimentada por emiss��o ac��stica

Mestrado em Engenharia Electrot��cnica e de Computadores

Phase growth control in low temperature PLD Co: TiO2 films by pressure

This paper reports on the structural and optical properties of Co-doped TiO2 thin films grown onto (0001)Al2O3 substrates by non-reactive pulsed laser deposition (PLD) using argon as buffer gas. It is shown that by keeping constant the substrate temperature at as low as 310 degrees C and varying only the background gas pressure between 7 Pa and 70 Pa, it is possible to grow either epitaxial rutile or pure anatase thin films, as well as films with a mixture of both polymorphs. The optical band gaps of the films are red shifted in comparison with the values usually reported for undoped TiO2, which is consistent with n-type doping of the TiO2 matrix. Such band gap red shift brings the absorption edge of the Co-doped TiO2 films into the visible region, which might favour their photocatalytic activity. Furthermore, the band gap red shift depends on the films' phase composition, increasing with the increase of the Urbach energy for increasing rutile content. (C) 2012 Elsevier B.V. All rights reserved.

Growth responses of Macrocystis pyrifera (Laminariales), Southern Chile, juvenile sporophytes to nutrient limitation

1st Mares Conference on Marine Ecosystems Health and Conservation. Olh��o, Portugal 17-21 November 2014.

Caracteriza����o da cultura de crack na cidade de S��o Paulo: padr��o de uso controlado

OBJETIVO: Caracterizar a situa����o do uso de crack na cidade de S��o Paulo, assim como o perfil sociodemogr��fico de seu usu��rio. PROCEDIMENTOS METODOL��GICOS: Estudo qualitativo etnogr��fico com amostra intencional de usu��rios (n=45) e ex-usu��rios de crack (n=17). Os participantes foram recrutados pela t��cnica de amostragem em cadeias e responderam a uma entrevista semi-estruturada, direcionada por question��rio, durante os anos de 2004 e 2005. O conjunto de cada quest��o e suas respectivas respostas originou relat��rios espec��ficos que foram interpretados individualmente. AN��LISE DOS RESULTADOS: O perfil predominante do usu��rio de crack foi ser homem, jovem, solteiro, de baixa classe socioecon��mica, baixo n��vel de escolaridade e sem v��nculos empregat��cios formais. O padr��o de uso mais freq��entemente citado foi o compulsivo, caracterizado pelo uso m��ltiplo de drogas e desenvolvimento de atividades il��citas em troca de crack ou dinheiro. Entretanto, identificou-se o uso controlado que consiste no uso n��o-di��rio de crack, mediado por fatores individuais, desenvolvidos intuitivamente pelo usu��rio e semelhantes, em natureza, ��s estrat��gias adotadas por ex-usu��rios para o alcance do estado de abstin��ncia. CONCLUS��ES: A cultura do uso de crack tem sofrido mudan��as quanto ao padr��o de uso. Embora a maioria dos usu��rios o fa��a de forma compulsiva, observou-se a exist��ncia do uso controlado, que merece maior detalhamento, principalmente quanto ��s estrat��gias adotadas para seu alcance.

Influ��ncia do tipo de chuteira em vari��veis preditoras do risco de entorse lateral do tornozelo

Introdu����o: No futebol, a entorse lateral do tornozelo (ELT) destaca-se como sendo a les��o mais prevalente. Potenciada pela variedade de chuteiras dispon��veis no mercado e pela crescente utiliza����o de relvados sint��ticos, a intera����o entre o terreno e o cal��ado tem assumido elevada relev��ncia como fator de risco para a ELT. A maior incid��ncia de les��es na 2�� parte do jogo traduz a necessidade do estudo dessa intera����o durante tarefas que envolvam fadiga. Objetivo: Estudar a influ��ncia das chuteiras em vari��veis preditoras do risco de ELT em relvado sint��tico sob duas condi����es: sem e com fadiga dos m��sculos eversores do tornozelo M��todos: Foi utilizada uma amostra de atletas saud��veis. Todos os indiv��duos realizaram 3 s��ries de 5 saltos m��dio-laterais uni-pod��licos, cada uma com 1 de 3 modelos de chuteiras (Turf, Hard e Firm ground) em duas condi����es: sem e com fadiga induzida pelo dinam��metro isocin��tico. Durante a tarefa, a atividade eletromiogr��fica do longo e curto peroniais, o valor das for��as de rea����o do solo e o movimento do retro-p�� (plano frontal), foram recolhidos e usados para calcular vari��veis cinem��ticas (evers��o/invers��o do tornozelo, o deslocamento e velocidade do centro de press��o), cin��ticas (taxa de crescimento das for��as de rea����o do solo) e neuromusculares (tempo de ativa����o muscular dos peroniais). Resultados: �� exce����o do tempo de ativa����o do curto peronial com o modelo Hard ground (sem fadiga vs com fadiga (p=0,050), n��o foram identificadas diferen��as estatisticamente significativas nas vari��veis preditoras de les��o, entre chuteiras, nem entre as duas condi����es avaliadas. Conclus��o: Para o teste funcional escolhido e executado por atletas saud��veis em sint��tico de 3�� gera����o, nenhuma das chuteiras apresenta maior risco de les��o (com e sem fadiga), tendo em conta as vari��veis em estudo.

HIV/AIDS risk among female sex workers who use crack in Southern Brazil

OBJECTIVE: To understand the social context of female sex workers who use crack and its impact on HIV/AIDS risk behaviors. METHODODOLOGICAL PROCEDURES: Qualitative study carried out in Foz do Igua��u, Southern Brazil, in 2003. Twenty-six in-depth interviews and two focus groups were carried out with female commercial sex workers who frequently use crack. In-depth interviews with health providers, community leaders and public policy managers, as well as field observations were also conducted. Transcript data was entered into Atlas.ti software and grounded theory methodology was used to analyze the data and develop a conceptual model as a result of this study. ANALYSIS OF RESULTS: Female sex workers who use crack had low self-perceived HIV risk in spite of being engaged in risky behaviors (e.g. unprotected sex with multiple partners). Physical and sexual violence among clients, occasional and stable partners was widespread jeopardizing negotiation and consistent condom use. According to health providers, community leaders and public policy managers, several female sex workers who use crack are homeless or live in slums, and rarely have access to health services, voluntary counseling and testing, social support, pre-natal and reproductive care. CONCLUSIONS: Female sex workers who use crack experience a plethora of health and social problems, which apparently affect their risks for HIV infection. Low-threshold, user-friendly and gender-tailored interventions should be implemented, in order to increase the access to health and social-support services among this population. Those initiatives might also increase their access to reproductive health in general, and to preventive strategies focusing on HIV/AIDS and other sexually transmitted infections.