301 research outputs found
Surgical and Oncological Updates in the Management of Gastric Cancer: the Role of Neoadjuvant Therapy and Minimally Invasive Surgery
No full textAlgoritms for image analysis of neural tissue for the evaluation of HIV therapies
No full textGli effetti della progressiva degenerazione del tessuto neurale causata dal virus dell’ HIV può essere simulata su culture di neuroni somministrando il composto virale neuro-tossico 3NP. É possibile quantificare la capacità di composti terapeutici a base di Paroxetina di ridurre gli effetti di degenerazione e morte del tessuto neurale per mezzo della valutazione dello stato di salute di culture di neuroni, analizzando immagini delle culture ottenute per mezzo di un microscopio a fluorescenza. L’obbiettivo di questo progetto é di analizzare questo tipo di immagini, con lo scopo di quantificarne tre principali caratteristiche: l’area totale dei neuron cell bodies la lunghezza totale dei neurite branches e il numero totale di small beads. Tramite l’implementazione di un programma di analisi di immagine e da una valutazione di tali risultati, è stato possibile confermare che i composti di Paroxetina usati hanno un effetto protettivo asso-dendritico sulle culture di neuron
Stratospheric Flight: Aeronautics at the Limit
No full textIn this book, Dr. Andras Sobester reviews the science behind high altitude flight. He takes the reader on a journey that begins with the complex physiological questions involved in taking humans into the "death zone." How does the body react to falling ambient pressure? Why is hypoxia (oxygen deficiency associated with low air pressure) so dangerous and why is it so difficult to 'design out' of aircraft, why does it still cause fatalities in the 21st century? What cabin pressures are air passengers and military pilots exposed to and why is the choice of an appropriate range of values such a difficult problem? How do high altitude life support systems work and what happens if they fail? What happens if cabin pressure is lost suddenly or, even worse, slowly and unnoticed? The second part of the book tackles the aeronautical problems of flying in the upper atmosphere. What loads does stratospheric flight place on pressurized cabins at high altitude and why are these difficult to predict? What determines the maximum altitude an aircraft can climb to? What is the 'coffin corner' and how can it be avoided? The history of aviation has seen a handful of airplanes reach altitudes in excess of 70,000 feet - what are the extreme engineering challenges of climbing into the upper stratosphere? Flying high makes very high speeds possible -- what are the practical limits? The key advantage of stratospheric flight is that the aircraft will be 'above the weather' - but is this always the case? Part three of the book investigates the extreme atmospheric conditions that may be encountered in the upper atmosphere. How high can a storm cell reach and what is it like to fly into one? How frequent is high altitude 'clear air' turbulence, what causes it and what are its effects on aircraft? The stratosphere can be extremely cold - how cold does it have to be before flight becomes unsafe? What happens when an aircraft encounters volcanic ash at high altitude? Very high winds can be encountered at the lower boundary of the stratosphere - what effect do they have on aviation? Finally, part four looks at the extreme limits of stratospheric flight. How high will a winged aircraft will ever be able to fly? What are the ultimate altitude limits of ballooning? What is the greatest altitude that you could still bail out from? And finally, what are the challenges of exploring the stratospheres of other planets and moons? The author discusses these and many other questions, the known knowns, the known unkonwns and the potential unknown unknowns of stratospheric flight through a series of notable moments of the recent history of mankind's forays into the upper atmospheres, each of these incidents, accidents or great triumphs illustrating a key aspect of what makes stratospheric flight aeronautics at the limit
Notes on meteorological balloon mission planning
No full textIn the 21st century the high altitude gas balloon remains an indispensable tool in atmospheric science, meteorology and other applications requiring stratospheric observations. A prerequisite of the effectiveness of many types of balloon operations is an accurate trajectory forecasting capability, complete with appropriate error estimates. This is particularly important in targeted flights, sample return missions or flights of expensive instruments, whose recovery is essential. The ASTRA (Atmospheric Science Through Robotic Aircraft) initiative led to the development of such a forecast model, which is at the centre of the present paper. A key source of error in such models is our incomplete understanding of the drag opposing the rise of balloons in the free atmosphere – here we propose a new, stochastic model based on empirical data derived from thousands of radiosonde flights. We also examine other sources of prediction error affecting the accuracy of the flight path forecast, such as uncertainties in the wind profile and balloon envelope manufacturing variability. A Monte Carlo framework is used to provide probabilistic touchdown point estimates taking these error sources into account. The above elements have been integrated into a web service, which can be used as a flight planning tool – here we review the key features of its architecture
Optimization models for shape-constrained function estimation problems involving nonnegative polynomials and their restrictions
No full textIn this thesis function estimation problems are considered that involve constraints on the shape of the estimator or some other underlying function. The function to be estimated is assumed to be continuous on an interval, and is approximated by a polynomial spline of given degree. First the estimation of univariate functions is considered under constraints that can be represented by the nonnegativity of affine functionals of the estimated function. These include bound constraints, monotonicity, and convexity constraints. A general framework is presented in which arbitrary combination of such constraints can be modeled and handled in a both theoretically and practically efficient manner, using semidefinite programming. The approach is illustrated by a variety of applications in statistical estimation. Numerical results are compared to those obtained using methods previously proposed in the statistical literature. Next, multivariate problems are considered. Shape constraints that are tractable in the univariate case are intractable in the multivariate setting. Hence, instead of following the univariate approach, polyhedral and spectrahedral (semidefinite) approximations are proposed, which are obtained by replacing nonnegative splines by piecewise weighted-sum-of-squares polynomial splines. A decomposition method for solving very large scale multivariate problems is also investigated. In order to include more constraints in the same unified framework, the notion of weighted-sum-of-squares functions is generalized to weighted-sum-of-squares cones in finite-dimensional real linear spaces endowed with a bilinear multiplication. It is shown that such cones are semidefinite representable, and the representation is explicitly constructed. Finally, seeking a method to circumvent the use of semidefinite programming in the solution of optimization problems over nonnegative and weighted-sum-of-squares polynomials, we study the conditions of optimality, as well as barrier functions in such optimization problems. For univariate polynomials, a method based on fast Fourier transform is provided that accelerates the evaluation of the logarithmic barrier function (and its first two derivatives) of the moment cone. This reduces the running time of some interior point methods for semidefinite programming from O(n^6) to O(n^3) when solving problems involving polynomial nonnegativity constraints.Ph.D.Includes bibliographical referencesIncludes vitaby Dávid Pap
A possible examination method for observing agriculture
No full textOn the basis of our examinations we have come to the conclusion that longitudinal examinations are the simplest and most up-to-date methods as well as the most cost-efficient ones to follow the decision-making, preparatory data collecting, processing and analysing opportunities serving the sustainability of agriculture better and better together with tracing down the feedback about the decisions to see if the given measure has really resulted in reaching the objectives. The method was proved to be able to supply both micro-and macro-level information in the desired breakdown, groupings and systems of connections. The development successive (panel) examination that we applied can serve as the basis of making decisions affecting huge areas by means of total listings and breakdowns. Moreover, it can also control their effects and aftermaths. We suggest the implementation of introducing this data collecting and information supplying method declared to be desirable also by the European Union. Implementation could be eased to a great extent by the fact that it is available for the organisations, as well.longitudinal examination, method, application, Research Methods/ Statistical Methods,
Estimation of overall mass transfer coefficient in osmotic distillation for gentle sour cherry juice concentration
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Du Symptôme au sacrifice. Histoire de Khady Fall
No full textAndras Zempléni, From Symptom to Sacrifice. The Story of Khady Fall. — This clinical case study is largely devoted to the presentation and interpretation of the autobiography of a Wolof priestess-therapeutist (nddpkat) whom the author saw regularly from 1962 to 1964. She continues to officiate the cult of ancestral spirits (rab) in a Dakar congregation of possessed. From about the age of 2 or 3 until becoming a nddpkat, Khady went through many pathological phases which a Western psychiatrist would undoubtedly class as hysterical episodes. In analysing, step by step, the contents of their conversations, the author shows how Khady gradually elaborated a symbolic structure — how she integrated and articulated the rab as signifiers of descent and affinity — in her efforts to solve a set of personal problems that are neither more nor less complex or "exotic" than those of Western sick. The commentaries are destined to bring out certain criticisms of the psychoanalytical and ethnological statements on the indefinite subject (from the "sons" of Totem and Taboo to the neuter pronoun so dear to psychoanalytical anthropology and to most ethnologists). They also seek a method by which individual situations, expressed by and in the language of the socio-religious signifiers of traditional cultures, can be understood clinically. The ethnologist could benefit by using this method when the teachings of his informants undeniably reveal their individual fate ; he could thus delimit the socio-symbolic processes — undetectable by mere fieldwork — that constitute, structure and support social relations.Résumé
Andras Zempléni, Du Symptôme au sacrifice. Histoire de Khady Fall. — Le corps de cette étude de cas clinique est constitué par la présentation et l'interprétation de l'autobiographie d'une prêtresse-thérapeute (nddpkat) wolof que l'auteur a fréquentée régulièrement de 1962 à 1964 et qui continue à exercer ses fonctions d'officiante du culte des esprits ancestraux (rab) dans une congrégation de possédées de Dakar. De l'âge de 2-3 ans jusqu'à son accession à la position de nddpkat, Khady avait traversé de nombreux épisodes pathologiques que le psychiatre occidental aurait sans doute catalogués comme des épisodes d'hystérie. En analysant, pas à pas, le contenu des entretiens, l'auteur montre comment Khady est parvenue à élaborer une structure symbolique — à intégrer et à articuler ces signifiants de filiation et d'alliance que sont les rab — dans ses efforts de résolution d'un ensemble de problèmes personnels qui ne sont, eux, ni plus ni moins complexes ou « exotiques » que ceux du malade occidental. Les commentaires sont destinés à mieux faire apparaître les éléments d'une critique des énoncés psychanalytiques et ethnologiques sur le sujet indéfini (des « fils » de Totem et tabou au pronom neutre affectionné par l'anthropologie psychanalytique et par la plupart des ethnologues), et à définir une méthode qui permettrait de rendre accessibles à la clinique des conjonctures individuelles exprimées par et dans le langage des signifiants socio-religieux des cultures traditionnelles. A s'en servir aux heures où les leçons de ses informateurs laissent deviner indéniablement leur destin d'individu, l'ethnologue pourrait bénéficier largement de cette méthode : elle lui permettrait de cerner les processus socio-symboliques — inaccessibles à l'enquête — qui constituent, structurent et étayent les rapports sociaux.Zempleni Andras. Du Symptôme au sacrifice. Histoire de Khady Fall. In: L'Homme, 1974, tome 14 n°2. pp. 31-77
Coupled simulator for research on the interaction between pedestrians and (automated) vehicles
No full textDriving simulators are regarded as valuable tools for human factors research on automated driving and traffic safety. However, simulators that enable the study of human-human interactions are rare. In this study, we present an open-source coupled simulator developed in Unity. The simulator supports input from head-mounted displays, motion suits, and game controllers. It facilitates research on interactions between pedestrians and humans inside manual and automated vehicles. We present results of a demo experiment on the interaction between a passenger in an automated car equipped with an external human-machine interface, a driver of a manual car, and a pedestrian. We conclude that the newly developed open-source coupled simulator is a promising tool for future human factors research.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Human-Robot InteractionMedical Instruments & Bio-Inspired Technolog
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