Assessing the Efficiency of Mother-to-Child HIV Prevention in Low- and Middle-Income Countries using Data Envelopment Analysis

AIDS is one of the most significant health care problems worldwide. Due to the difficulty and costs involved in treating HIV, preventing infection is of paramount importance in controlling the AIDS epidemic. The main purpose of this paper is to explore the potential of using Data Envelopment Analysis (DEA) to establish international comparisons on the efficiency implementation of HIV prevention programmes. To this effect we use data from 52 low- and middle-income countries regarding the prevention of mother-to-child transmission of HIV. Our results indicate that there is a remarkable variation in efficiency of prevention services across nations, suggesting that a better use of resources could lead to more and improved services, and ultimately, prevent the infection of thousands of children. These results also demonstrate the potential strategic role of DEA for the efficient and effective planning of scarce resources to fight the epidemic.HIV Prevention; DEA; Mother-to-Child HIV Transmission.

A Globo no mundo: internacionalização de uma empresa televisiva com sotaque brasileiro

Este artigo analisa a política internacional da Globo e observa as características dessa internacionalização. O foco principal é o jornalismo da emissora, analisado por meio das reportagens produzidas no exterior e veiculadas no Jornal Nacional, o telejornal de maior audiência. A expansão para o mercado externo faz parte da própria formação da emissora, influenciada pela escola norte-americana que moldou o “fazer jornalismo” da Globo e também influenciou na produção ficcional e na sua comercialização

O novo media na imprensa: as notícias sobre a Internet no jornal Público

Este estudo visa analisar quais são as fontes que o jornal Público utiliza em suas páginas para retratar o media Internet, e como esse novo meio está alterando a forma de se fazer jornalismo, com base nas relações que envolvem os jornalistas, as fontes e os leitores. Para isso foram analisadas as notícias veiculadas no Público, durante todo o ano de 2004, que estão na base de dados do projeto Mediascópio - uma iniciativa da Universidade do Minho que recolhe e analisa reportagens que falam sobre os media, veiculadas nos principais jornais portugueses. O Público foi escolhido como referência por ser um dos mais conceituados diários de Portugal, tendo sido publicado pela primeira vez em 5 de Março de 1990. É um jornal que apresenta uma estreita ligação com a Internet. Desde 1995 está presente na Web e, de acordo com uma pesquisa publicada em 2005, se tornou o site mais visitado pelos portugueses, entre os jornais do País que disponibilizam seus conteúdos em versão on-line. Além disso, no iníci

Análisis cuantitativo y modelización del metabolismo de la levadura Pichia pastoris

Consultable des del TDXTítol obtingut de la portada digitalitzadaEl presente trabajo está centrado en el análisis y modelización del metabolismo central de la levadura Pichia pastoris. Concretamente, el objetivo de este trabajo consistió en analizar la distribución de flujos en las principales vías metabólicas del metabolismo central de esta levadura mediante distintas aproximaciones experimentales y matemáticas basadas en un modelo metabólico estequiométrico y compartimentalizado. Los datos experimentales fueron obtenidos en su mayor parte del trabajo de tesis de A. Solà (Solà, 2004, tesis doctoral, Universitat Autònoma de Barcelona), centrado en experimentos de marcaje isotópico con 13C de cultivos de P. pastoris operados en quimiostato a =0,05 y 0,16 h-1 con diferentes fuentes de carbono (glucosa, glicerol, metanol y mezclas de glicerol/metanol). Los datos fisiológicos experimentalmente obtenidos en dicho estudio se han reconciliado a través de ecuaciones de balances elementales y por grado de reductancia; además, se ha propuesto una ecuación estequiométrica para la formación de biomasa para cada condición de cultivo estudiada. Los datos reconciliados a través de ecuaciones de balances elementales se han usado para el análisis de flujos metabólicos; en primer lugar, se ha utilizado la metodología clásica; los resultados obtenidos en esta primera aproximación se compararon con datos experimentales previamente obtenidos mediante técnicas de marcaje isotópico de 13C por A. Solà. El segundo estudio ha consistido en el cálculo de flujos metabólicos introduciendo restricciones derivadas de cocientes de flujos metabólicos estimados experimentalmente mediante técnicas de 13C-RMN. Dado el reducido número de restricciones derivadas de experimentos de 13C-RMN que se pueden aplicar en este modelo metabólico (3 o 4), en un tercer estudio se ha realizado una primera aproximación a metodologías de simulación y optimización del diseño de experimentos de marcaje isotópico con el objetivo de implementar un procedimiento experimental que permitiera obtener datos suficientes para determinar con más precisión los flujos a través de determinadas rutas de la red, particularmente los relacionados a la vía de las pentosas fosfato (PP). Concretamente, para explorar esta estrategia se han realizado estudios para la optimización de un experimento de marcaje para un cultivo operado en quimiostato utilizando glicerol como fuente de carbono a =0,05h-1; la estrategia de marcaje optimizada se llevó posteriormente a cabo en el laboratorio y se analizó los patrones de marcaje de los principales metabolitos (incluyendo algunos aminoácidos) y aminoácidos proteinogénicos mediante LC-MS/MS y 2D-RMN, respectivamente. Ello ha permitido comparar y combinar datos experimentales obtenidos mediante dos estrategias de análisis para la estimación de flujos metabólicos. Así, globalmente, este trabajo permite concluir que el análisis clásico de flujos metabólicos (MFA) es una herramienta de cálculo que está limitada a redes poco complejas; sin embargo cuando se aplican restricciones derivadas del análisis por 13C-RMN al MFA, se observa que esta metodología de análisis presenta alta sensibilidad para la determinación de distribución de flujos metabólicos en el ciclo de los ácidos tricarboxílicos (TCA) y reacciones de transporte entre el citoplasma y la mitocondria. Por el contrario, utilizando una metodología de 13C-MFA basada en datos derivados de 13C-LC-MS, se observa que este método presenta poca sensibilidad en redes metabólicas compartimentalizadas, pues no permite distinguir los pools de metabolitos de un compartimiento dado (mitocondria/citoplasma). Sin embargo, este método presenta alta sensibilidad para la determinación de flujos a través de la vía de las PP. Así pues, la combinación de distintas metodologías basadas en datos de experimentos de marcaje isotópico ha permitido mejorar la información sobre el comportamiento del sistema. Finalmente, se ha llevado a cabo un análisis estructural de la red metabólica a través de la metodología del análisis de módulos elementales, así como una primera aproximación para su combinación con el análisis de flujos metabólicos basados en datos de marcaje isotópico con el objetivo de facilitar la interpretación fisiológica de los resultados, es decir, determinar cuales son las principales vías metabólicas activas bajo un estado fisiológico dado y cual es el flujo a través de dichas rutas.This study is focused on the analysis and modelling of the central carbon metabolism of the yeast Pichia pastoris. In particular, the major aim of this study was to analyze de flux distribution through the main metabolic pathways of the central metabolism of this yeast by jeans of different experimental and mathematical approaches, based on a stoichiometric and compartmentalized metabolic model. Experimental data was mostly obtained from previous studies from A. Solà (Solà, 2004, PhD thesis, Universitat Autònoma de Barcelona), describing isotopic labelling experiments with 13C of P. pastoris cells growing on chemostat cultures at a growth rate of =0.05 and 0.16 h-1, on different carbon sources (glucose, glycerol, methanol and mixtures of glycerol/methanol). The experimental physiological data obtained in A. Solà's study have been reconciliated by means of elementary and grade of reductance balance equations; moreover, a stoichiometric equation for the formation of biomass has been proposed for each of the studied growth condition. The data reconciliated by elementary balance equations have been used for metabolic flux analysis. First, the classic metabolic flux analysis methodology has been applied; the obtained results in this first approximation were compared with the experimental data previously generated from 13C-labeling experiments by A. Solà. Second, metabolic fluxes have been calculated introducing a number of restrictions derived from metabolic flux ratios experimentally estimated by 13C-NMR. Third, given the reduced number of restrictions derived from these experiments that are actually aplicable to the defined metabolic model (3 or 4), we performed a first approximation to methodologies for simulation and optimisation of isotopic labeling experiments; the aim of such approach was to implement an experimental procedure to allow for the generation of labelling data needed for the precise determination of fluxes through some pathways of the network, particularly those related to the pentose phosphate pathway (PPP). In order to explore this strategy, studies for the optimisation of a labelling experiment of cells growing on glycerol in chemostat cultures at a growth rate of 0.05 h-1 were performed. The optimised labelling strategy was subsequently implemented in the laboratory; the labelling patterns of the major metabolites (including some amino acids) of the central carbon metabolism and, of the proteinogenic amino acids, were analysed by LC-MS/MS and 2D-NMR, respectively. This allowed us comparing and combining experimental labelling data derived from two analytical strategies for the calculation of metabolic fluxes. Overall, this study illustrates that classic metabolic flux análisis (MFA) is a mathematical tool limited to networks of low complexity. Nevertheless, when restrictions derived from 13C-NMR analyses are introduced MFA, this methodology shows a high sensitivity for the calculation of the metabolic flux distribution in the tricarboxylic acid cycle (TCA) and transport reactions of TCA intermediates between cytoplasm and mitochondria. In contrast, by using a 13C-MFA methodology using data derived from 13C-LC-MS, we observe that this method shows low sensitivity for compartimentalized metabolic networks, as it did not allow distinguishing pools of a given metabolite found in different compartments (e.g. mitochondria/cytoplasm). Nevertheless, this method shows high sensitivity for determining fluxes through the PPP

Behavioral changes in experimentally infected Rattus norvegicus by Toxocara cati or T. canis

Toxocara canis e T. cati são nematódeos parasitos de cães e gatos, transmitidos pela ingestão de ovos larvados, pela via transmamária, por predação de hospedeiro paratênico e via transplacentária; essa última via ocorre na infecção por T. canis. Muitos parasitos apresentam mecanismos para alterar o comportamento de seus hospedeiros e garantir sua transmissão. Vários pesquisadores demonstraram ocorrência de alterações comportamentais, utilizando camundongos como modelo de hospedeiro paratênico para T. canis. Porém, não há na literatura, estudos sobre a ocorrência de alterações de comportamento de Rattus norvegicus experimentalmente infectados por T. cati. Os objetivos do presente trabalho foram verificar a distribuição de larvas de T.cati em exemplares de R. norvegicus e determinar as fases miotrópica e neurotrópica na infecção deste parasito; bem como comparar comportamentos de fêmeas e machos deste roedor experimentalmente infectado com inóculo de T. canis ou T. cati, nos períodos agudo e crônico da infecção. As variáveis avaliadas foram: ansiedade, atividade motora e força muscular. Inicialmente utilizaram-se 21 ratos com idade de oito semanas, infectados com 300 ovos de T. cati. Nos dias 3, 5, 8, 10, 15, 30 e 60 pósinfecção três animais foram mortos para contagem das larvas em seus órgãos. A seguir foram utilizados 50 exemplares fêmeas e 50 machos de R. norvegicus, com seis a oito semanas. Para cada sexo os animais foram divididos em três grupos: T. canis - 20 ratos infectados com 300 ovos de T. canis, T.cati -20 ratos infectados com 300 ovos de T. cati e controle - 10 ratos sem infecção. Nos dias 5, 15, 40 e 70 após a infecção, os animais dos grupos infectados e controle foram submetidos à avaliação das variáveis comportamentais e determinação da força muscular. Pôde-se verificar que a fase neurotrópica das larvas ocorreu principalmente no 15º dpi e 30º dpi. A fase miotrópica ocorreu em todo o período do experimento, porém especialmente no 15º e 60º dpi. Em relação à força muscular das fêmeas, pode-se observar diferença significante nos três grupos apenas no 40º dpi. Nos machos houve diferença significante entre os três grupos durante todo experimento. Nas variáveis comportamentais, somente as fêmeas do grupo infectado com T. canis apresentaram diferença significativa no 40º dpi em relação ao grupo controle. Os machos não apresentaram diferenças significantes na avaliação do comportamento. Pode-se concluir que T. cati teve comportamento migratório diferenciado, exemplares de R. norvegicus independente do sexo apresentaram maior decréscimo na força muscular quando infectados com T. cati e que apenas fêmeas infectadas por T. canis tiveram seu comportamento alterado permanecendo por mais tempo em condições de exposição em campo aberto.Toxocara canis and T. cati are parasitic nematodes of dogs and cats, transmitted by the ingestion of embryonated eggs, by the transmamary and transplacentary routes or by predation of paratenic hosts harboring third-stage larvae in their bodies. The transplacentary route occurs only in T. canis infection. Many parasites have mechanisms to change the host\'s behavior in order to ensure their transmission. Several researchers have demonstrated the occurrence of behavioral changes, using mice as a model of paratenic host for T. canis. However, there are no studies on the occurrence of changes in behavior of Rattus norvegicus experimentally infected with T. cati. The aims of this study were to investigate the distribution of T.cati larvae in R. norvegicus and determine the myotropic and neurotropic phases in the infection of this parasite, and to compare behavior of male and female rodents experimentally infected with either T. canis or T. cati, in the acute and chronic periods of infection. The variables measured were: anxiety, motor activity and muscle strength. Initially we used 21 rats aged eight weeks, infected with 300 eggs of T. cati. On days 3, 5, 8, 10, 15, 30 and 60 post-infection three animals were killed to count the larvae in the organs and muscle. In the second experiment 50 females and 50 males of R. norvegicus, with six to eight weeks of age were used. For each sex the animals were divided into three groups: T. canis - 20 rats infected with 300 eggs of T. canis, T.cati -20 rats infected with 300 eggs of T. cati and control - 10 rats infection free. On days 5, 15, 40 and 70 post-infection, the infected animals and control groups were submitted to evaluation of behavioral variables and determination of forepaws\' muscle strength. It was verified that the neurotropic phase of larvae occurred mainly in the 15th dpi and 30 dpi. Myotropic phase occurred during all experimental period, but especially 15th and 60th dpi. In regard to muscle strength in females, a significant difference in the three groups was observed only after 40th post-infection. In males there was significant difference among the three groups throughout the experiment. In the behavioral variables, only the female of the group infected with T. canis showed significant differences after 40th dpi when compared to control group. Males showed no significant differences in the performance evaluation. It can be concluded that T. cati migration behavior was different, R. norvegicus regardless of sex showed greater decrease in muscle strength when infected with T. cati and only infected females by T. canis showed behavioral changes remaining more time under conditions of exposure in the open field

Implementation obstacles and strategy implementation failure

Purpose – The paper addresses the following question: How do strategy implementation obstacles relate to each other and affect strategy implementation? Method – The research methodology is qualitative and based on an extensive review of the literature and on an in-depth case study analysis. Findings – This paper draws two main conclusions. The first is that the many obstacles that impact the strategy implementation process can interact and be strongly interrelated in dynamic and complex manners. The second is that obstacles can lead to and reinforce other obstacles, eventually forming long chains of blockages. Originality – Strategy implementation remains a difficult task with improbable success. This paper provides a contribution to an explanation on why so many strategy implementation efforts fail. It is one of the very few papers addressing the issue of the relationships between strategy implementation obstacles.info:eu-repo/semantics/publishedVersio

Sustainable Approach to Weed Management: The Role of Precision Weed Management

In the last few decades, the increase in the world’s population has created a need to produce more food, generating, consequently, greater pressure on agricultural production. In addition, problems related to climate change, water scarcity or decreasing amounts of arable land have serious implications for farming sustainability. Weeds can affect food production in agricultural systems, decreasing the product quality and productivity due to the competition for natural resources. On the other hand, weeds can also be considered to be valuable indicators of biodiversity because of their role in providing ecosystem services. In this sense, there is a need to carry out an effective and sustainable weed management process, integrating the various control methods (i.e., cultural, mechanical and chemical) in a harmonious way, without harming the entire agrarian ecosystem. Thus, intensive mechanization and herbicide use should be avoided. Herbicide resistance in some weed biotypes is a major concern today and must be tackled. On the other hand, the recent development of weed control technologies can promote higher levels of food production, lower the amount of inputs needed and reduce environmental damage, invariably bringing us closer to more sustainable agricultural systems. In this paper, we review the most common conventional and non-conventional weed control strategies from a sustainability perspective, highlighting the application of the precision and automated weed control technologies associated with precision weed management (PWM).info:eu-repo/semantics/publishedVersio

Sustainable Approach to Weed Management: The Role of Precision Weed Management

In the last few decades, the increase in the world’s population has created a need to produce more food, generating, consequently, greater pressure on agricultural production. In addition, problems related to climate change, water scarcity or decreasing amounts of arable land have serious implications for farming sustainability. Weeds can affect food production in agricultural systems, decreasing the product quality and productivity due to the competition for natural resources. On the other hand, weeds can also be considered to be valuable indicators of biodiversity because of their role in providing ecosystem services. In this sense, there is a need to carry out an effective and sustainable weed management process, integrating the various control methods (i.e., cultural, mechanical and chemical) in a harmonious way, without harming the entire agrarian ecosystem. Thus, intensive mechanization and herbicide use should be avoided. Herbicide resistance in some weed biotypes is a major concern today and must be tackled. On the other hand, the recent development of weed control technologies can promote higher levels of food production, lower the amount of inputs needed and reduce environmental damage, invariably bringing us closer to more sustainable agricultural systems. In this paper, we review the most common conventional and non-conventional weed control strategies from a sustainability perspective, highlighting the application of the precision and automated weed control technologies associated with precision weed management (PWM).info:eu-repo/semantics/publishedVersio

Equity valuation: Netflix, Inc

This dissertation concerns the estimation of the fair value of Netflix, Inc. share at the end of December 31, 2020. After a review of the entertainment and media industry and Netflix’s past business and financial performance, two approaches will be presented to value the company. The first is a DCF analysis based on Netflix’s financial statements, using WACC as the discount rate. As a second stage valuation, an analysis comparing the company’s multiples with those of similar companies was made to assess both the DCF’s forecasts and Netflix’s performance with the competition. Additionally, we complemented our valuation by conducting a sensitivity analysis to check the robustness of our assumptions and respective estimations. Through our DCF analysis, we reached a target price of $306.60. By emphasizing the results of the two valuation methodologies applied, the premise is that Netflix is overvalued in comparison to the market price of$540.73 as of the end of 2020. Thus, the results obtained lead us to recommend selling Netflix’s shares.Esta dissertação tem como objetivo estimar o justo valor da ação da Netflix, Inc. a 31 de dezembro de 2020. Após uma revisão da indústria de entretenimento e media e do desempenho financeiro e operacional histórico da Netflix, apresentam-se duas abordagens para avaliar a empresa. A primeira é uma análise DCF com base nas demonstrações financeiras da Netflix, usando o WACC como taxa de desconto. A segunda é uma análise comparando os múltiplos da empresa com os de empresas semelhantes para avaliar os resultados da análise DCF e o desempenho da Netflix face à concorrência. Adicionalmente, complementámos a nossa avaliação conduzindo uma análise de sensibilidade para verificar a robustez dos nossos pressupostos e das respetivas projeções. Através da nossa análise de DCF, alcançámos um preço-alvo de $306.60. Dando ênfase aos resultados dos dois métodos de avaliação utilizados, a conclusão é a de que a Netflix está sobrevalorizada em comparação com o preço de fecho de$540.73 no final de 2020. Desta forma, os resultados obtidos levam-nos a recomendar a venda das ações da Netflix