5,150 research outputs found

    A Multi-level Analysis on Implementation of Low-Cost IVF in Sub-Saharan Africa: A Case Study of Uganda.

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    Introduction: Globally, infertility is a major reproductive disease that affects an estimated 186 million people worldwide. In Sub-Saharan Africa, the burden of infertility is considerably high, affecting one in every four couples of reproductive age. Furthermore, infertility in this context has severe psychosocial, emotional, economic and health consequences. Absence of affordable fertility services in Sub-Saharan Africa has been justified by overpopulation and limited resources, resulting in inequitable access to infertility treatment compared to developed countries. Therefore, low-cost IVF (LCIVF) initiatives have been developed to simplify IVF-related treatment, reduce costs, and improve access to treatment for individuals in low-resource contexts. However, there is a gap between the development of LCIVF initiatives and their implementation in Sub-Saharan Africa. Uganda is the first country in East and Central Africa to undergo implementation of LCIVF initiatives within its public health system at Mulago Women’s Hospital. Methods: This was an exploratory, qualitative, single, case study conducted at Mulago Women’s Hospital in Kampala, Uganda. The objective of this study was to explore how LCIVF initiatives have been implemented within the public health system of Uganda at the macro-, meso- and micro-level. Primary qualitative data was collected using semi-structured interviews, hospital observations informal conversations, and document review. Using purposive and snowball sampling, a total of twenty-three key informants were interviewed including government officials, clinicians (doctors, nurses, technicians), hospital management, implementers, patient advocacy representatives, private sector practitioners, international organizational representatives, educational institution, and professional medical associations. Sources of secondary data included government and non-government reports, hospital records, organizational briefs, and press outputs. Using a multi-level data analysis approach, this study undertook a hybrid inductive/deductive thematic analysis, with the deductive analysis guided by the Consolidated Framework for Implementation Research (CFIR). Findings: Factors facilitating implementation included international recognition of infertility as a reproductive disease, strong political advocacy and oversight, patient needs & advocacy, government funding, inter-organizational collaboration, tension to change, competition in the private sector, intervention adaptability & trialability, relative priority, motivation &advocacy of fertility providers and specialist training. While barriers included scarcity of embryologists, intervention complexity, insufficient knowledge, evidence strength & quality of intervention, inadequate leadership engagement & hospital autonomy, poor public knowledge, limited engagement with traditional, cultural, and religious leaders, lack of salary incentives and concerns of revenue loss associated with low-cost options. Research contributions: This study contributes to knowledge of factors salient to implementation of LCIVF initiatives in a Sub-Saharan context. Effective implementation of these initiatives requires (1) sustained political support and favourable policy & legislation, (2) public sensitization and engagement of traditional, cultural, and religious leaders (3) strengthening local innovation and capacity building of fertility health workers, in particular embryologists (4) sustained implementor leadership engagement and inter-organizational collaboration and (5) proven clinical evidence and utilization of LCIVF initiatives in innovator countries. It also adds to the literature on the applicability of the CFIR framework in explaining factors that influence successful implementation in developing countries and offer opportunities for comparisons across studies

    Scaling up integrated photonic reservoirs towards low-power high-bandwidth computing

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    Z-Numbers-Based Approach to Hotel Service Quality Assessment

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    In this study, we are analyzing the possibility of using Z-numbers for measuring the service quality and decision-making for quality improvement in the hotel industry. Techniques used for these purposes are based on consumer evalu- ations - expectations and perceptions. As a rule, these evaluations are expressed in crisp numbers (Likert scale) or fuzzy estimates. However, descriptions of the respondent opinions based on crisp or fuzzy numbers formalism not in all cases are relevant. The existing methods do not take into account the degree of con- fidence of respondents in their assessments. A fuzzy approach better describes the uncertainties associated with human perceptions and expectations. Linguis- tic values are more acceptable than crisp numbers. To consider the subjective natures of both service quality estimates and confidence degree in them, the two- component Z-numbers Z = (A, B) were used. Z-numbers express more adequately the opinion of consumers. The proposed and computationally efficient approach (Z-SERVQUAL, Z-IPA) allows to determine the quality of services and iden- tify the factors that required improvement and the areas for further development. The suggested method was applied to evaluate the service quality in small and medium-sized hotels in Turkey and Azerbaijan, illustrated by the example

    RELATIONSHIP BETWEEN BODY-SEAT INTERFACE PRESSURE AND DISCOMFORT DURING ROWING

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    Discomfort and pressure-related tissue injury to the buttocks are common complaints among rowers. The soft tissues of the buttocks are non-uniformly loaded during rowing. The current state of literature on seating discomfort is inconclusive as to a desirable body-seat interface pressure pattern. The purpose of this study was to determine whether localising pressure under bony protuberances or diffusing pressure over soft tissues would result in the least amount of discomfort. Force sensing arrays were used to measure body-seat interface pressures in 11 elite female rowers during rowing. Peak pressure measures were identified and pressure gradients were calculated. Discomfort was quantified using a questionnaire, and pressure data were then correlated with discomfort scores.Discomfort was weakly correlated with each of maximal pressure gradient (r=0.45) and peak pressure (r=0.43). The findings indicate pressure should be redistributed in order to avoid concentrating pressure under the bony protuberances o f the buttocks

    Porous Silicon Photonics for Label-Free Interferometric Biosensing and Flat Optics

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    This dissertation uses porous silicon as a material platform to explore novel optical effects in three domains: (i) It studies dispersion engineering in integrated waveguides to achieve high performance group index sensing. With proper design parameters, the sensor waveguides can theoretically achieve 6 times larger group index shift compared to the actual bulk effective refractive index shift. We demonstrate the guided mode confinement factor to be a key parameter in design and implementation of these waveguides. (ii) It explores multicolor laser illumination to experimentally demonstrate perceptually enhanced colorimetric sensing, overcoming the limitations faced by many contemporary colorimetric sensors. Our technique allows our sensor to achieve ~ 7 to 30 times higher sensitivities and ~ 30 to 1000 times lower limits of detection compared to current colorimetric sensors. (iii) It develops a novel imprinting technique to laterally pattern arbitrary refractive index on the porous silicon surface to realize nanoscale flat optical components. We demonstrate and characterize imprinted flat lens arrays and show how myriads of possible applications are to be implemented using this nanoimprinting technique. While the material primarily used in this dissertation is porous silicon, many of the demonstrated techniques are generalizable and can be extended towards other materials of interest to achieve high performance patterning and sensing

    Deposição de filmes do diamante para dispositivos electrónicos

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    This PhD thesis presents details about the usage of diamond in electronics. It presents a review of the properties of diamond and the mechanisms of its growth using hot filament chemical vapour deposition (HFCVD). Presented in the thesis are the experimental details and discussions that follow from it about the optimization of the deposition technique and the growth of diamond on various electronically relevant substrates. The discussions present an analysis of the parameters typically involved in the HFCVD, particularly the pre-treatment that the substrates receive- namely, the novel nucleation procedure (NNP), as well as growth temperatures and plasma chemistry and how they affect the characteristics of the thus-grown films. Extensive morphological and spectroscopic analysis has been made in order to characterise these films.Este trabalho discute a utilização de diamante em aplicações electrónicas. É apresentada uma revisão detalhada das propriedades de diamante e dos respectivos mecanismos de crescimento utilizando deposição química a partir da fase vapor com filament quente (hot filament chemical vapour deposition - HFCVD). Os detalhes experimentais relativos à otimização desta técnica tendo em vista o crescimento de diamante em vários substratos com relevância em eletrónica são apresentados e discutidos com detalhe. A discussão inclui a análise dos parâmetros tipicamente envolvidos em HFCVD, em particular do pré-tratamento que o substrato recebe e que é conhecido na literatura como "novel nucleation procedure" (NNP), assim como das temperaturas de crescimento e da química do plasma, bem como a influência de todos estes parâmetros nas características finais dos filmes. A caracterização morfológica dos filmes envolveu técnicas de microscopia e espetroscopia.Programa Doutoral em Engenharia Eletrotécnic

    Scalable software and models for large-scale extracellular recordings

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    The brain represents information about the world through the electrical activity of populations of neurons. By placing an electrode near a neuron that is firing (spiking), it is possible to detect the resulting extracellular action potential (EAP) that is transmitted down an axon to other neurons. In this way, it is possible to monitor the communication of a group of neurons to uncover how they encode and transmit information. As the number of recorded neurons continues to increase, however, so do the data processing and analysis challenges. It is crucial that scalable software and analysis tools are developed and made available to the neuroscience community to keep up with the large amounts of data that are already being gathered. This thesis is composed of three pieces of work which I develop in order to better process and analyze large-scale extracellular recordings. My work spans all stages of extracellular analysis from the processing of raw electrical recordings to the development of statistical models to reveal underlying structure in neural population activity. In the first work, I focus on developing software to improve the comparison and adoption of different computational approaches for spike sorting. When analyzing neural recordings, most researchers are interested in the spiking activity of individual neurons, which must be extracted from the raw electrical traces through a process called spike sorting. Much development has been directed towards improving the performance and automation of spike sorting. This continuous development, while essential, has contributed to an over-saturation of new, incompatible tools that hinders rigorous benchmarking and complicates reproducible analysis. To address these limitations, I develop SpikeInterface, an open-source, Python framework designed to unify preexisting spike sorting technologies into a single toolkit and to facilitate straightforward benchmarking of different approaches. With this framework, I demonstrate that modern, automated spike sorters have low agreement when analyzing the same dataset, i.e. they find different numbers of neurons with different activity profiles; This result holds true for a variety of simulated and real datasets. Also, I demonstrate that utilizing a consensus-based approach to spike sorting, where the outputs of multiple spike sorters are combined, can dramatically reduce the number of falsely detected neurons. In the second work, I focus on developing an unsupervised machine learning approach for determining the source location of individually detected spikes that are recorded by high-density, microelectrode arrays. By localizing the source of individual spikes, my method is able to determine the approximate position of the recorded neuriii ons in relation to the microelectrode array. To allow my model to work with large-scale datasets, I utilize deep neural networks, a family of machine learning algorithms that can be trained to approximate complicated functions in a scalable fashion. I evaluate my method on both simulated and real extracellular datasets, demonstrating that it is more accurate than other commonly used methods. Also, I show that location estimates for individual spikes can be utilized to improve the efficiency and accuracy of spike sorting. After training, my method allows for localization of one million spikes in approximately 37 seconds on a TITAN X GPU, enabling real-time analysis of massive extracellular datasets. In my third and final presented work, I focus on developing an unsupervised machine learning model that can uncover patterns of activity from neural populations associated with a behaviour being performed. Specifically, I introduce Targeted Neural Dynamical Modelling (TNDM), a statistical model that jointly models the neural activity and any external behavioural variables. TNDM decomposes neural dynamics (i.e. temporal activity patterns) into behaviourally relevant and behaviourally irrelevant dynamics; the behaviourally relevant dynamics constitute all activity patterns required to generate the behaviour of interest while behaviourally irrelevant dynamics may be completely unrelated (e.g. other behavioural or brain states), or even related to behaviour execution (e.g. dynamics that are associated with behaviour generally but are not task specific). Again, I implement TNDM using a deep neural network to improve its scalability and expressivity. On synthetic data and on real recordings from the premotor (PMd) and primary motor cortex (M1) of a monkey performing a center-out reaching task, I show that TNDM is able to extract low-dimensional neural dynamics that are highly predictive of behaviour without sacrificing its fit to the neural data

    Study of the Degradation of New Lubricant Oil Formulations with the Design and Demands of Current and Future Engines

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    [ES] El análisis de los aceites lubricantes de motor, englobado dentro de las tareas realizadas en el Oil Condition Monitoring (OCM), resulta ser una herramienta poderosa con la cual se es capaz de extraer información de utilidad. Por este motivo, en esta Tesis se decidió explotar este campo realizando un estudio en profundidad centrado en tres aspectos: mejorar las técnicas y protocolos ya existentes, desarrollar procedimientos propios acorde con las necesidades y requisitos del momento y, para terminar, poner en valor la información obtenida del análisis de los lubricantes mediante el uso de tratamientos estadísticos y quimiométricos. Bajo estas tres premisas, se ha desarrollado toda la tarea de investigación de esta Tesis. En primer lugar, en relación con el análisis de los aceites lubricantes, se realizó un estudio acerca de la degradación de cuatro formulaciones de aceites lubricantes. En este estudio se analizaron aspectos propios de los aceites como: su viscosidad cinemática, oxidación, nitración, caída de los aditivos antioxidantes, etc. así como parámetros de desgaste de motor (monitorizando la presencia de metales). Como resultado de este estudio fue posible encontrar limitaciones en las técnicas actuales, lo cual condujo a realizar mejoras y/o adaptaciones de estas técnicas para conseguir obtener la información deseada. El siguiente aspecto tratado en esta Tesis es una consecuencia de la necesidad de, en ciertas situaciones, disponer de información acerca de uno o varios parámetros de una determinada forma y con un grado de precisión elevado. El caso en cuestión analizado en la Tesis está relacionado con la cuantificación de hollín en el aceite lubricante. Respecto a la cuantificación del hollín se requirió encontrar una técnica que fuera capaz de aportar información de una forma rápida y, además, poder detectar pequeños cambios. Esta técnica fue la espectroscopia Ultravioleta-Visible, con la cual se diseñó un protocolo analítico que permitiera trabajar con muestras de aceites lubricante con muy poco uso y, por ende, poca cantidad de hollín disuelta, consiguiendo resultados muy satisfactorios en periodos de tiempo cortos. Por último, debido a la disponibilidad de una cantidad de datos considerable fruto del trabajo realizado durante todo el tiempo de duración de la Tesis, se decidió emplear toda ella para conseguir extraer la máxima información posible gracias al uso de tratamientos estadísticos y quimiométricos. Este trabajo, nuevo en la línea, se dividió en dos vertientes: la primera focalizada en el conjunto de datos de los aceites ya caracterizados (procedentes del estudio de la degradación de los aceites) y la otra parte en encontrar sinergias entre las técnicas espectroscópicas (FT-IR y NIR) y los ensayos de caracterización de los lubricantes. Como resultado de ello, se obtuvieron relaciones entre parámetros que anteriormente no se tenían presentes, así como modelos predictivos de propiedades de los lubricantes a partir del análisis de sus espectros. El presente documento de Tesis se encuentra redactado en dos idiomas: en español y en inglés. Principalmente el documento se encuentra redactado en inglés para hacer especial énfasis en aquellas labores de investigación desarrolladas en esta etapa, así como los resultados derivados de los diferentes estudios realzados. Mientras que, la parte confeccionada en español hace referencia a aquellos aspectos más descriptivos del documento de Tesis.[CA] L'anàlisi dels olis lubrificants de motor, englobat dins de les tasques realitzades en el Oil Condition Monitoring (OCM), resulta ser una eina poderosa amb la qual s'és capaç d'extraure informació d'utilitat. Per aquest motiu, en aquesta Tesi es va decidir explotar aquest camp realitzant un estudi en profunditat centrat en tres aspectes: millorar les tècniques i protocols ja existents, desenvolupar procediments propis d'acord amb les necessitats i requisits del moment i, per a acabar, posar en valor la informació obtinguda de l'anàlisi dels lubrificants mitjançant l'ús de tractaments estadístics i quimiomètrics. Sota aquestes tres premisses, s'ha desenvolupat tota la tasca d'investigació d'aquesta Tesi. En primer lloc, en relació a l'anàlisi dels olis lubrificants, es va realitzar un estudi sobre la degradació de quatre formulacions d'olis lubrificants. En aquest estudi es van analitzar aspectes propis dels olis com: la seua viscositat cinemàtica, oxidació, nitració, caiguda dels additius antioxidants, etc. així com paràmetres de desgast de motor (monitorant la presència de metalls). Com a resultat d'aquest estudi va ser possible trobar limitacions en les tècniques actuals, la qual cosa va conduir a realitzar millores i/o adaptacions d'aquestes tècniques per a aconseguir obtindre la informació desitjada. El següent aspecte tractat en aquesta Tesi és una conseqüència de la necessitat de, en unes certes situacions, disposar d'informació sobre un o diversos paràmetres d'una determinada forma i amb un grau de precisió elevat. El cas en qüestió analitzat en la Tesi està relacionat amb la quantificació de sutge (soot en anglès). Respecte a la quantificació del soot es va requerir trobar una tècnica que fora capaç d'aportar informació d'una forma ràpida i, a més, poder detectar xicotets canvis. Aquesta tècnica va ser l'espectroscòpia Ultravioleta-Visible, amb la qual es va dissenyar un protocol analític que permetera treballar amb mostres d'oli lubrificant amb molt poc ús i, per tant, poca quantitat de soot dissolta, aconseguint resultats molt satisfactoris en períodes de temps curts. Finalment, a causa de la disponibilitat d'una quantitat de dades considerable fruit del treball realitzat durant tot el temps de duració de la Tesi, es va decidir emprar tota ella per a aconseguir extraure la màxima informació possible gràcies a l'ús de tractaments estadístics i quimiomètrics. Aquest treball, nou en la línia, es va dividir en dos vessants: la primera focalitzada en el conjunt de dades dels olis ja caracteritzats (procedents de l'estudi de la degradació dels olis) i l'altra part a trobar sinergies entre les tècniques espectroscòpiques (FT-IR i NIR) i els assajos de caracterització dels lubrificants. Com a resultat d'això, es van obtindre relacions entre paràmetres que anteriorment no es tenien presents així com models predictius de propietats dels lubrificants a partir de l'anàlisi dels seus espectres. El present document de Tesi es troba redactat en dos idiomes: en espanyol i en anglès. Principalment el document es troba redactat en anglès per a fer especial èmfasi en aquelles labors d'investigació desenvolupades en aquesta etapa així com els resultats derivats dels diferents estudis realitzats. Mentre que, la part confeccionada en espanyol, fa referència a aquells aspectes més descriptius del document de Tesi.[EN] The analysis of engine lubricating oils, encompassed within the tasks carried out in Oil Condition Monitoring (OCM), is a powerful tool with which it is possible to extract useful information. For this reason, in this Thesis it has been decided to exploit this field by carrying out an in-depth study focusing on three aspects: improving existing techniques and protocols, developing our own procedures in accordance with current needs and requirements and finally, adding value to the information obtained from the analysis of lubricants through the use of statistical and chemometric treatments. All the research work in this Thesis has been carried out under these three premises. Firstly, in relation to the analysis of lubricating oils, a study was carried out on the degradation of four lubricating oil formulations. This study analysed aspects of the oils, such as their kinematic viscosity, oxidation, nitration, antioxidant additives depletion, etc. as well as engine wear parameters (monitoring the presence of metals). Using this study, it was possible to find limitations in the current techniques, which led to improvements and/or adaptations of these techniques in order to obtain the desired information. The next aspect dealt with in this Thesis is a consequence of the need, in certain situations, to have information about one or more parameters in a certain form and with a high degree of accuracy. The case in question analysed in the Thesis is related to the quantification of soot. With regard to soot quantification, it was necessary to find a technique that was capable of providing information quickly and, in addition, being able to detect small changes. This technique was Ultraviolet-Visible spectroscopy, with which an analytical protocol was designed to work with samples of lubricating oils with very little use and therefore, with a small amount of dissolved soot, achieving very satisfactory results in short periods of time. Finally, due to the availability of a considerable amount of information resulting from the work carried out throughout the duration of the Thesis, it was decided to use all of these data to extract as much information as possible, thanks to the use of statistical and chemometric treatments. This work, new in the research line, was divided into two parts: the first focused on the dataset of oils already characterised (from the study of oil degradation) and the other on finding synergies between spectroscopic techniques (FT-IR and NIR) and lubricant characterisation tests. As a result, relationships between previously unknown parameters were obtained, as well as predictive models of lubricant properties based on the analysis of their spectra. This Thesis document is written in two languages: Spanish and English. The document is mainly written in English in order to place special emphasis on the research work carried out at this stage, as well as the results derived from the different studies carried out. The part written in Spanish refers to the more descriptive aspects of the Thesis document.García Barberá, A. (2022). Study of the Degradation of New Lubricant Oil Formulations with the Design and Demands of Current and Future Engines [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181668TESI

    Understanding Drugs Markets

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    Drawing on anthropology, historical sociology and social-epidemiology, this multidisciplinary book investigates how pharmaceuticals are produced, distributed, prescribed, (and) consumed, and regulated in order to construct a comprehensive understanding of the issues that drive (medicine) pharmaceutical markets in the Global South today.   Based on primary research conducted in Benin and Ghana, and additional data collected in Cambodia and the Ivory Coast, this volume uses artemisinin-based combination therapies (ACTs) against malaria as a central case study. It highlights the influence of the countries colonial and post-colonial history on their models for state regulation, production, and distribution, explores the determining role transnational actors as well as industries from the North but also and increasingly from the South play in influencing local pharmaceutical markets and looks at the behaviour of health care professionals and individuals. Stepping back, the authors then unpick the pharmaceuticalization process and the multiple regulations at stake by looking at the workings of, and linkages between, (biomedical health) pharmaceutical systems, (representatives of companies) industries, actors in private distribution, and consumer practices.   Providing a thorough comparative analysis of the advantages and disadvantages of different pharmaceutical systems, it is an important contribution to the literature on pharmaceutalization and the governance of medication. It is of interest to students, researchers and policy-makers interested in medical anthropology, the sociology of health and illness, global health, healthcare management and pharmacy. The Open Access version of this book, available at http://www.taylorfrancis.com/books/9780429329517, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license
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