Laser guide stars wavefront sensors for the EELT

The Adaptive Optics is the measurement and correction in real time of the wavefront aberration of the star light caused by the atmospheric turbulence, that limits the angular resolution of ground based telescopes and thus their capabilities to deep explore faint and crowded astronomical objects. The lack of natural stars enough bright to be used as reference sources for the Adaptive Optics, over a relevant fraction of the sky, led to the introduction of artificial reference stars. The so-called Laser Guide Stars are produced by exciting the Sodium atoms in a layer laying at 90km of altitude, by a powerful laser beam projected toward the sky. The possibility to turn on a reference star close to the scientific targets of interest has the drawback in an increased difficulty in the wavefront measuring, mainly due to the time instability of the Sodium layer density. These issues are increased with the telescope diameter. In view of the construction of the 42m diameter European Extremely Large Telescope a detailed investigation of the achievable performances of Adaptive Optics becomes mandatory to exploit its unique angular resolution . The goal of this Thesis was to present a complete description of a laboratory Prototype development simulating a Shack-Hartmann wavefront sensor using Laser Guide Stars as references, in the expected conditions for a 42m telescope. From the conceptual design, through the opto-mechanical design, to the Assembly, Integration and Test, all the phases of the Prototype construction are explained. The tests carried out shown the reliability of the images produced by the Prototype that agreed with the numerical simulations. For this reason some possible upgrades regarding the opto-mechanical design are presented, to extend the system functionalities and let the Prototype become a more complete test bench to simulate the performances and drive the future Adaptive Optics modules design.

Self-identification of problems in the process of listening to English in pre-service interpreters

Questa tesi ha come oggetto di studio i problemi riscontrati nelle trascrizioni di testi orali in lingua inglese prodotte da 39 studenti della laurea magistrale in Interpretazione. Nel Capitolo 1 viene presentato l’ascolto, che viene definito prima da un punto di vista storico, poi analizzato come processo composto da quattro fasi, come sostiene Michael Rost (2011). Il capitolo si conclude con l’ascolto nell’ambito dell’interpretazione. Nel Capitolo 2 viene analizzato in maniera contrastiva l’apprendimento dell’ascolto nella prima e nella seconda lingua. I primi due capitoli forniscono le basi per comprendere il caso di studio. Il Capitolo 3 concerne la metodologia dello studio. Vengono presentati il metodo di analisi delle trascrizioni, la categorizzazione dei problemi riscontrati e il processo di creazione del sistema di analisi utilizzato. Nel Capitolo 4 vengono presentati i dati ottenuti seguendo il metodo esposto nel Capitolo 3. Si presentano i problemi riscontrati, che vengono suddivisi in categorie in base a ciò che può averli causati. Il Capitolo 5 è dedicato alle conclusioni. Qui vengono suggerite possibili strategie mirate ad aiutare gli studenti di Interpretazione a migliorare le proprie capacità di ascolto in lingua inglese. Esta tesis quiere analizar los problemas encontrados en transcripciones de textos orales en inglés hechas por 39 estudiantes del máster en Interpretación. En el Capítulo 1 se presenta la escucha, que se define primero desde una perspectiva histórica, y luego como un proceso formado por cuatro fases, como argumenta Michael Rost (2011). El capítulo se cierra con la escucha en el ámbito de la interpretación. En el Capítulo 2 se analizan de forma contrastiva el aprendizaje de la escucha en la primera y segunda lengua. Los primeros dos capítulos constituyen la base para comprender el caso de estudio. El Capítulo 3 atañe a la metodología del estudio. Se presentan el método de análisis de las transcripciones, la categorización de los problemas encontrados y el proceso de creación del sistema de análisis que se ha empleado. En el Capítulo 4 se proporcionan los datos obtenidos gracias al método presentado en el Capítulo 3. Se presentan los problemas encontrados, que han sido divididos en categorías según qué puede haberlos ocasionado. El Capítulo 5 está dedicado a las conclusiones. Aquí se sugieren posibles estrategias cuyo objetivo es ayudar a los estudiantes de Interpretación a mejorar sus capacidades de escucha en inglés.

Il popolo finlandese nella letteratura umoristica: proposta di traduzione di “Xenophobe's guide to the Finns”

Nel presente elaborato è analizzato il popolo finlandese attraverso la traduzione in italiano della guida umoristica "Xenophobe's guide to the Finns". L'analisi consiste in un primo capitolo sull'approfondimento del viaggio e della letteratura ad esso ispirata fino ai giorni nostri. Il secondo capitolo è incentrato sul popolo finlandese e gli stereotipi che lo caratterizzano, e il terzo analizza le difficoltà riscontrate nella traduzione.

The canine hair cycle - a guide for the assessment of morphological and immunohistochemical criteria

The hair follicle has a lifelong capacity to cycle through recurrent phases of controlled growth (anagen), regression (catagen) and quiescence (telogen), each associated with specific morphological changes. A comprehensive classification scheme is available for mice to distinguish the cycle stages anagen I-VI, catagen I-VIII and telogen. For dogs, such a classification system does not exist, although alopecia associated with hair cycle arrest is common. We applied analogous morphological criteria and various staining techniques to subdivide the canine hair cycle stages to the same extent as has been done in mice. Of all the staining techniques applied, haematoxylin and eosin stain, Sacpic, Masson Fontana and immunohistochemistry for vimentin and laminin proved to be most useful. To evaluate the applicability of our criteria, we investigated skin biopsies from healthy beagle dogs (n=20; biopsies from shoulder and thigh) kept in controlled conditions. From each biopsy, at least 50 hair follicles were assessed. Statistical analysis revealed that 30% of the follicles were in anagen (12% early and 18% late), 8% in catagen (2% early, 5% late and 1% not determinable) and 27% in telogen. Thirty-five per cent of hair follicles could not be assigned to a specific cycle stage because not all follicles within one biopsy were oriented perfectly. In conclusion, this guide will not only be helpful for the investigation of alopecic disorders and possibly their pathogenesis, but may also serve as a basis for research projects in which the comparison of hair cycle stages is essential, e.g. comparative analysis of gene expression patterns.

The Locking Compression Paediatric Hip Plate: technical guide and critical analysis

Osteotomies of the proximal femur and stable fixation of displaced femoral neck fractures are demanding operations. An LCP Paediatric Hip Plate was developed to make these operations safer and less demanding. The article focuses on the surgical technique and critically analyses the device.

A guide to sparkology: the taxonomy of elementary cellular Ca2+ signaling events

Since the discovery of the Ca(2+) spark as an elementary event of cellular Ca(2+) signaling almost 15 years ago, the family of newly described Ca(2+) signal entities has been ever growing. While scientists working in Ca(2+) signaling may have maintained an overview over the specifics of this nomenclature, those outside the field often make the complaint that they feel hopelessly lost. With the present review we collect and summarize systematic information on the many Ca(2+) signaling events described in a variety of tissues and cells, and we emphasize why and how each of them has its own importance. Most of these signals are taking place in the cytosol of the respective cells, but several events have been recorded from intracellular organelles as well, where they may serve their own specific functions. Finally, we also try to convey an integrated view as to why cellular microdomain signaling is of fundamental biological importance.

Bayesian statistics in oncology: a guide for the clinical investigator

The rise of evidence-based medicine as well as important progress in statistical methods and computational power have led to a second birth of the >200-year-old Bayesian framework. The use of Bayesian techniques, in particular in the design and interpretation of clinical trials, offers several substantial advantages over the classical statistical approach. First, in contrast to classical statistics, Bayesian analysis allows a direct statement regarding the probability that a treatment was beneficial. Second, Bayesian statistics allow the researcher to incorporate any prior information in the analysis of the experimental results. Third, Bayesian methods can efficiently handle complex statistical models, which are suited for advanced clinical trial designs. Finally, Bayesian statistics encourage a thorough consideration and presentation of the assumptions underlying an analysis, which enables the reader to fully appraise the authors' conclusions. Both Bayesian and classical statistics have their respective strengths and limitations and should be viewed as being complementary to each other; we do not attempt to make a head-to-head comparison, as this is beyond the scope of the present review. Rather, the objective of the present article is to provide a nonmathematical, reader-friendly overview of the current practice of Bayesian statistics coupled with numerous intuitive examples from the field of oncology. It is hoped that this educational review will be a useful resource to the oncologist and result in a better understanding of the scope, strengths, and limitations of the Bayesian approach.

Critical appraisal of meta-analyses: an introductory guide for the practicing surgeon

ABSTRACT: Meta-analyses are an essential tool of clinical research. Meta-analyses of individual randomized controlled trials frequently constitute the highest possible level of scientific evidence for a given research question and allow surgeons to rapidly gain a comprehensive understanding of an important clinical issue. Moreover, meta-analyses often serve as cornerstones for evidence-based surgery, treatment guidelines, and knowledge transfer. Given the importance of meta-analyses to the medical (and surgical) knowledge base, it is of cardinal importance that surgeons have a basic grasp of the principles that guide a high-quality meta-analysis, and be able to weigh objectively the advantages and potential pitfalls of this clinical research tool. Unfortunately, surgeons are often ill-prepared to successfully conduct, critically appraise, and correctly interpret meta-analyses. The objective of this educational review is to provide surgeons with a brief introductory overview of the knowledge and skills required for understanding and critically appraising surgical meta-analyses as well as assessing their implications for their own surgical practice.