Discrete-Time Fractional Variational Problems

We introduce a discrete-time fractional calculus of variations on the time scale $h\mathbb{Z}$, $h > 0$. First and second order necessary optimality conditions are established. Examples illustrating the use of the new Euler-Lagrange and Legendre type conditions are given. They show that solutions to the considered fractional problems become the classical discrete-time solutions when the fractional order of the discrete-derivatives are integer values, and that they converge to the fractional continuous-time solutions when $h$ tends to zero. Our Legendre type condition is useful to eliminate false candidates identified via the Euler-Lagrange fractional equation.Comment: Submitted 24/Nov/2009; Revised 16/Mar/2010; Accepted 3/May/2010; for publication in Signal Processing

To Value Pain In Children: A Reflection Oriented To Praxis

Introdução: A dor, ao ser considerada em Portugal como 5º sinal vital em 2003, obriga à sua mensuração, registo e implementação de medidas adequadas para a minimizar. Contudo, sendo um fenómeno subjetivo, a sua mensuração é difícil. Os Enfermeiros que prestam cuidados a utentes pediátricos têm na avaliação da dor um desafio acrescido. Objetivo: Descrever a forma como os Enfermeiros questionados valorizam a dor das crianças a quem prestam cuidados; confrontar a valorização da dor, expressa pelos enfermeiros questionados, com o Guia Orientador de Boa Prática (GOBP) sobre a dor, da Ordem dos Enfermeiros. Material e Métodos: Foram questionados 41 Enfermeiros da prática clínica pediátrica, sobre o significado da valorização da dor na criança e efetuada uma análise qualitativa das suas respostas, classificando-as em Unidades de Texto (UT). Resultados: Da análise das 41 respostas dadas pelos Enfermeiros emergiram 4 Categorias principais. Assim, a dor é afirmada como o Quinto Sinal Vital em 12 UT, como Reconhecimento e Cuidado Personalizado em 26 UT, como Exigência Profissional em 6 UT; e como Caminho de Excelência em 18 UT, sendo que estes conceitos estão de acordo com o GOBP. Conclusões: Concluímos que valorizar a dor da criança como 5º Sinal Vital é uma Exigência Profissional que Reconhece a criança como pessoa a quem se presta um Cuidado Personalizado de forma a que os cuidados prestados se encontrem cada vez mais no Caminho da Excelência

Low level of virological failure and drug resistance among patients receiving antiretroviral treatment under programme conditions in Maputo, Mozambique

Mexico AIDS Conference 200

Produção de mudas de goiabeira.

A goiaba ocupa lugar de destaque dentre as frutas tropicais brasileiras. No Vale do São Francisco, a área plantada com a cultura é de 5.000 hectares, distribuídos entre os estados de Pernambuco e Bahia. A goiaba é uma ótima opção para a diversificação, entretanto, com os problemas surgidos por causa do nematoide, muitos pomares foram erradicados. Visando contribuir para a redução desses problemas, deve-se dar importância especial à produção de mudas livres de nematoides, pois, é no preparo delas que grande parte das áreas são contaminadas por essa praga. A produção de mudas é uma das etapas fundamentais no processo de implantação de um pomar e pode ser determinante para o sucesso da cultura a ser implantada. As técnicas de produção devem atender às necessidades do produtor, levando-se em consideração a disponibilidade e a localização de áreas, o grau de tecnologia e os recursos financeiros disponíveis.bitstream/item/54791/1/COT148.pd

Biorreatores: aspectos gerais e sua utilização para cultura de tecidos vegetais.

Cultura de Tecidos Vegetais; Biorreatores na cultura de tecidos vegetais; Vantagens do uso de biorreatores em relação ao processo de micropropagação convencional; Problemas no uso de biorreatores e como contorná-los; Principais tipos de biorreatores; Principais parâmetros físicoquímicos em um biorreator; Formas e efeitos da agitação; Formas de transferência e efeitos do oxigênio dissolvido; Efeitos provocados pelas variações de CO2 e pH.bitstream/CPATSA-2009-09/40172/1/SDC214.pd

Proof of Principle of an On-Line Digitizer with +18 ppm Repeatability and 1.2 μs Real-Time Delay for Power Converters Control Loop

The proof of principle of an on-line digitizer designed to be integrated into the digital control loop of a high-voltage modulator for ultra-repeatable power converters is presented. The presented selective analogue zoom allows digitizing with 18 ppm repeatability the voltage around the nominal level (10V1 V) and, at the same time, the initial transients with relaxed performance. In addition, in order not to jeopardize the digital control loop stability, the whole digitizing system has to introduce a low real-time delay; this is assessed to be less than 1:2 s. Initially, the specifications of the real-time control are presented and translated into data acquisition requirements. Then, the main design choices of the digitizer are discussed and Pspice simulation results are reported to validate the concept design. Finally, experimental results of a validation case study developed for the power converter designed at ETH Zurich and University of Laval for the new linear particle accelerator under study at CERN, the Compact LInear Collider CLIC, are reported and compared with the simulation outcomes

Participatory varietal selection of potato using the mother & baby trial design: A gender-responsive trainer’s guide.

This guide aims to provide step-by-step guidance on facilitating and documenting the PVS dynamics using the MBT design to select, and eventually release, potato varieties preferred by end-users that suit male and female farmers ’different needs, diverse agro-systems, and management practices, as well as traders ’and consumers’ preferences

Modelling post-fire vegetation recovery in Portugal

Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion. <br><br> The main goals of the present work are (i) to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii) to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii) to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively. <br><br> The study relies on monthly values of NDVI over 11 years (1998–2009), at 1 km × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of <i>Pinus pinaster</i> over the area, and by the fact that coniferous forests tend to recover slower than transitional woodland-shrub, which tend to dominate the areas following the fire event

Drought impacts on vegetation in the pre- and post-fire events over Iberian Peninsula

The present work aims to study the combined effect of drought and large wildfires in the Iberian Peninsula relying on remotely sensed data of vegetation dynamics and leaf moisture content, in particular monthly NDVI, NDWI and NDDI time series from 1999–2009, derived from VEGETATION dataset. The impact of the exceptional 2004/2005 drought on vegetation was assessed for vegetation recovering from the extraordinary fire season of 2003 and on the conditions that contributed to the onsetting of the fire season of 2005. Drought severity was estimated by the cumulative negative effect on photosynthetic activity (NDVI) and vegetation dryness (NDDI), with about 2/3 of Iberian Peninsula presenting vegetative stress and low water availability conditions, in spring and early summer of 2005. Furthermore, NDDI has shown to be very useful to assess drought, since it combines information on vegetation and water conditions. Moreover, we show that besides looking at the inter-annual variability of NDVI and NDDI, it is useful to evaluate intra-annual changes (δNDVI and δNDDI), as indicators of change in vegetation greenness, allowing a detailed picture of the ability of the different land-cover types to resist to short-term dry conditions. In order to assess drought impact on post-fire regeneration, recovery times were evaluated by a mono-parametric model based on NDVI data and values corresponding to drought months were set to no value. Drought has shown to delay recovery times for several months in all the selected scars from 2003. The analysis of vegetation dynamics and fire selectivity in 2005 suggests that fires tended to occur in pixels presenting lower vegetative and water stress conditions during spring and early summer months. Additionally, pre-fire vegetation dynamics, in particular vegetation density and water availability during spring and early summer, has shown to influence significantly the levels of fire damage. These results stress the role of fuel availability in fire occurrence and impact on the Iberian Peninsula