Using Computer Algebra Packages to Complement the Spreadsheet Construction of Binomial Option Trees: The Example of Mathcad

In this paper we show how the mathematical programming package Mathcad can be used to complement the construction of a binomial option tree in Excel. A binomial option tree is first constructed in Excel using standard spreadsheet 'cut and paste' operations. The same binomial tree is then constructed in Mathcad. We conclude that spreadsheet construction of the tree provides students with a sound concept of the underlying mechanics of the option tree. Additionally, the Mathcad construction reinforces the mathematical notation found in many option pricing texts (e.g. summation signs and indices) and allows for the construction of a more flexible lattice that may be easily altered (e.g. the number of steps). In the process students are provided with an understanding of how to construct option trees in the increasingly important world of computer algebra packages.

Subcentimeter depth resolution using a single-photon counting time-of-flight laser ranging system at 1550 nm wavelength

We demonstrate subcentimeter depth profiling at a stand off distance of 330m using a time-of-flight approach based on time-correlated single-photon counting. For the first time to our knowledge, the photon-counting time-of-flight technique was demonstrated at a wavelength of 1550nm using a superconducting nanowire single-photon detector. The performance achieved suggests that a system using superconducting detectors has the potential for low-light-level and eye-safe operation. The system’s instrumental response was 70ps full width at half-maximum, which meant that 1cm surface-to-surface resolution could be achieved by locating the centroids of each return signal. A depth resolution of 4mm was achieved by employing an optimized signal-processing algorithm based on a reversible jump Markov chain Monte Carlo method

Vision dynamique pour la navigation d'un robot mobile

Les travaux présentés dans cette thèse concernent l’étude des fonctionnalités visuelles sur des scènes dynamiques et ses applications à la robotique mobile. Ces fonctionnalités visuelles traitent plus précisément du suivi visuel d’objets dans des séquences d’images. Quatre méthodes de suivi visuel ont été étudiées, dont trois ont été développées spécifiquement dans le cadre de cette thèse. Ces méthodes sont : (1) le suivi de contours par un snake, avec deux variantes permettant son application à des séquences d’images couleur ou la prise en compte de contraintes sur la forme de l’objet suivi, (2) le suivi de régions par différences de motifs, (3) le suivi de contours par corrélation 1D, et enfin (4) la méthode de suivi d’un ensemble de points, fondée sur la distance de Hausdorff, développée lors d’une thèse précédente. Ces méthodes ont été analysées pour différentes tâches relatives à la navigation d’un robot mobile; une comparaison dans différents contextes a été effectuée, donnant lieu à une caractérisation des cibles et des conditions pour lesquelles chaque méthode donne de bons résultats. Les résultats de cette analyse sont pris en compte dans un module de planification perceptuelle, qui détermine quels objets (amers plans) le robot doit suivre pour se guider le long d’une trajectoire. Afin de contrôler l’exécution d’un tel plan perceptuel, plusieurs protocoles de collaboration ou d’enchaînement entre méthodes de suivi visuel ont été proposés. Finalement, ces méthodes, ainsi qu’un module de contrôle d’une caméra active (site, azimut, zoom), ont été intégrées sur un robot. Trois expérimentations ont été effectuées: a) le suivi de route en milieu extérieur, b) le suivi de primitives pour la navigation visuelle en milieu intérieur, et c) le suivi d’amers plans pour la navigation fondée sur la localisation explicite du robot. ABSTRACT : The work presented on this thesis concerns the study of visual functionalities over dynamic scenes and their applications to mobile robotics. These visual functionalities consist on visual tracking of objects on image sequences. Four methods of visual tracking has been studied, from which tree of them has been developed specifically for the context of this thesis. These methods are: (1) snakes contours tracking, with two variants, the former, to be able to applying it to a sequence of color images and the latter to consider form constraints of the followed object, (2) the tracking of regions by templates differences, (3) contour tracking by 1D correlation, and (4) the tracking method of a set of points, based on Hausdorff distance, developed on a previous thesis. These methods have been analyzed for different tasks, relatives to mobile robot’s navigation. A comparison for different contexts has been done, given to a characterization of objects and conditions for which each method gives the best results. Results from this analysis has been take into account on a perceptual planification module, that determines which objects (plane landmarks) must be tracked by the robot, to drive it over a trajectory. In order to control the execution of perceptual plan, a lot of collaboration or chaining protocols have been proposed between methods. Finally, these methods and a control module of an active camera (pan, tilt, zoom), has been integrated on a robot. Three experiments have been done: a) road tracking over natural environments, b) primitives tracking for visual navigation over human environments and c) landmark tracking for navigation based on explicit localization of robo

Model Stitching: Looking For Functional Similarity Between Representations

Model stitching (Lenc & Vedaldi 2015) is a compelling methodology to compare different neural network representations, because it allows us to measure to what degree they may be interchanged. We expand on a previous work from Bansal, Nakkiran & Barak which used model stitching to compare representations of the same shapes learned by differently seeded and/or trained neural networks of the same architecture. Our contribution enables us to compare the representations learned by layers with different shapes from neural networks with different architectures. We subsequently reveal unexpected behavior of model stitching. Namely, we find that stitching, based on convolutions, for small ResNets, can reach high accuracy if those layers come later in the first (sender) network than in the second (receiver), even if those layers are far apart.Comment: 5 pages, 2 figure

Death receptor 5 expression is inversely correlated with prostate cancer progression.

Prostate carcinoma (PCa) is one of the most common cancers in men. Prostate-specific antigen (PSA) has been widely used to predict the outcome of PCa and screening with PSA has resulted in a decline in mortality. However, PSA is not an optimal prognostic tool as its sensitivity may be too low to reduce morbidity and mortality. Consequently, there is a demand for additional robust biomarkers for prostate cancer. Death receptor 5 (DR5) has been implicated in the prognosis of several cancers and it has been previously shown that it is negatively regulated by Yin Yang 1 (YY1) in prostate cancer cell lines. The present study investigated the clinical significance of DR5 expression in a prostate cancer patient cohort and its correlation with YY1 expression. Immunohistochemical analysis of protein expression distribution was performed using tissue microarray constructs from 54 primary PCa and 39 prostatic intraepithelial neoplasia (PIN) specimens. DR5 expression was dramatically reduced as a function of higher tumor grade. By contrast, YY1 expression was elevated in PCa tumors as compared with that in PIN, and was increased with higher tumor grade. DR5 had an inverse correlation with YY1 expression. Bioinformatic analyses corroborated these data. The present findings suggested that DR5 and YY1 expression levels may serve as progression biomarkers for prostate cancer

Influ?ncia da sazonalidade clim?tica na estabilidade de taludes em Vo?orocas no Complexo Metam?rfico do Ba??o.

Programa de P?s-Gradua??o em Geotecnia. N?cleo de Geotecnia, Escola de Minas, Universidade Federal de Ouro Preto.A regi?o de rochas gn?issicas e gran?ticas do Complexo do Ba??o, no interior do Quadril?tero Ferr?fero (MG), ? conhecida historicamente pela exist?ncia de alta densidade de vo?orocas de grandes dimens?es, alcan?ando at? 50m de profundidade, configurando uma situa??o de elevado risco geot?cnico para moradores e constru??es no entorno. Embora as causas que provocam tais eros?es sejam variadas, ? sabido que, ao atingir o n?vel fre?tico, o avan?o ? controlado por condi??es complexas de eros?o subsuperficial e, sobretudo, por escorregamentos rotacionais. Dados hist?ricos mostram que os escorregamentos nos taludes destas vo?orocas ocorrem n?o somente na esta??o chuvosa, como tamb?m na esta??o seca. Objetivando entender melhor a din?mica destes taludes, foi elaborado um modelo conceitual detalhado de uma vo?oroca inst?vel baseando-se em grande volume de dados pr?vios e de novos levantamentos de campo geof?sicos e de aerofotogrametria, al?m de novos ensaios de laborat?rio de caracteriza??o dos solos. Com este modelo conceitual, fez-se pelo per?odo de um ano hidrol?gico a an?lise de estabilidade do talude mais cr?tico desta vo?oroca por equil?brio-limite acoplada a uma simula??o num?rica de fluxo por elementos finitos. Os resultados mostraram duas varia??es c?clicas do n?vel fre?tico ao longo do ano hidrol?gico, 2,97m no sop? do talude e 1,24m no interior do talude, atingindo o n?vel m?ximo geral no per?odo de estiagem devido a recarga atrasada em consequ?ncia da espessa zona n?o saturada. Tamb?m foi constatada a exist?ncia de fluxos ascendentes no sop? do talude com elevados gradientes de sa?da. O fator de seguran?a do talude apresentou um comportamento c?clico e pouco vari?vel, com valores baixos ao longo do ano hidrol?gico, com uma diminui??o de 3% no per?odo de estiagem. Comprovou-se, portanto, que os taludes das vo?orocas apresentam condi??o metaest?vel e que podem se instabilizar tanto no per?odo ?mido, quando as ?guas recarregam o sop? do talude, como no per?odo seco, por recarga atrasada. Acredita-se que com estes resultados seja mais f?cil dimensionar m?todos de estabiliza??o destas fei??es.The gneissic and granitic rocks of the Ba??o Complex region, in the ?Quadril?tero Ferr?fero (MG)?, are historically known for the existence of high density of gullies of great dimensions, reaching up to 50 meters in depth, leading to a situation of high geotechnical risk for people and buildings. Although the causes for such erosion vary, it is known that when the water table is reached, its development is controlled by complex conditions of subsurface erosion and mostly by rotational landslides. Historical data shows that landslides in the gullies? slopes happened both in the rainy season and the dry season. To understand the dynamics of these slopes a detailed conceptual model of an unstable gully was developed based on an extensive volume of existing historical data, along with geophysical and aerophotogrammetry fieldwork. Additionally, a laboratory test for the characterization of soils was performed. The objective of this conceptual model was to develop a limit equilibrium stability analysis of the most critical slope of the gully throughout a hydrological year, along with numerical simulations of flow using finite elements. The results showed two cyclical variations in the groundwater table over the hydrological year; 2.97 meters at the toe of the slope, and 1.24 meters within the slope, reaching the general maximum level during the dry season as a result of late recharge due to the thickness of the unsaturated zone. The results also verified the existence of upward flows at the toe of the gully with high gradients of outflow. The safety factor of the slope presented a cyclical, slightly variable, behavior with low safety factors throughout the hydrological year, with a diminution of 3% in dry season. Therefore, the meta-stable condition of the gully slopes was verified, as well as its unstable condition during the wet season with the recharge at the toe of the slope, and during the dry season with late recharge. It is expected that with this result it will be easier to design stabilization methods for these erosive features

Cinética de liberación de cafeína en emulsiones múltiples estabilizadas por complejos solubles binarios y ternarios de carboximetilcelulosa, proteínas de suero y péptidos

Emulsiones múltiples (EM's) agua-en-aceite-en-agua conteniendo cafeína fueron desarrolladas para su aplicación como sistemas de liberación controlada, mediante el diseño de películas interfaciales formadas por complejos binarios y ternarios solubles (proteína de lactosuero (W), péptidos de lactosuero (P) y carboximetilcelulosa (C)). El tamaño de gota de aceite de todas las emulsiones múltiples no cambió significativamente a lo largo de 21 días de almacenamiento, pero el tamaño de gota inicial, las propiedades viscoelásticas y las tasas de liberación de cafeína dependieron de la composición de los complejos solubles. El peso molecular de la fracción de proteína predominante en los complejos solubles proteína-polisacárido fue un factor determinante de las propiedades de las emulsiones múltiples. Cuando la proteína de suero predominó en los complejos solubles, en oposición a los péptidos del suero, el tamaño de gota fue más pequeño, las propiedades viscoelásticas fueron más elevadas y la cinética de liberación de cafeína fue más lenta al ser determinada mediante el modelo de KorsmeyerPeppas

Biliary peritonitis due to a ruptured amebic liver abscess mimicking a periampullary tumor and liver metastases with the elevation of CA 19-9 and CA 125: a case report

Introduction: An amebic liver abscess is the most common presentation of extraintestinal amebiasis. This condition is the result of a parasite infection caused by Entamoeba histolytica. Materials and Methods: We report a case of a 53-year-old male who presented with abdominal pain in the right upper quadrant, jaundice, and a 10-kg weight loss within a 1-month span. Results and Conclusion: A wide range of symptoms and findings in the imaging tests suggestive of neoplasia, elevated levels of CA 19-9 and CA 125, and the presentation of biliary peritonitis as a complication makes this case a challenge for its approach and management.Revisión por pare

Impact of astigmatism and high-order aberrations on subjective best focus

12 págs.; 9 figs.; 1 tab.© 2015 ARVO. We studied the role of native astigmatism and ocular aberrations on best-focus setting and its shift upon induction of astigmatism in 42 subjects (emmetropes, myopes, hyperopes, with-the-rule [WTR] and against-the-rule [ATR] myopic astigmats). Stimuli were presented in a custom-developed adaptive optics simulator, allowing correction for native aberrations and astigmatism induction (+1 D; 6-mm pupil). Best-focus search consisted on randomized-step interleaved staircase method. Each subject searched best focus for four different images, and four different conditions (with/without aberration correction, with/without astigmatism induction). The presence of aberrations induced a significant shift in subjective best focus (0.4 D; p < 0.01), significantly correlated (p = 0.005) with the best-focus shift predicted from optical simulations. The induction of astigmatism produced a statistically significant shift of the best-focus setting in all groups under natural aberrations (p = 0.001), and in emmetropes and in WTR astigmats under corrected aberrations (p < 0.0001). Best-focus shift upon induced astigmatism was significantly different across groups, both for natural aberrations and AO-correction (p < 0.0001). Best focus shifted in opposite directions in WTR and ATR astigmats upon induction of astigmatism, symmetrically with respect to the best-focus shift in nonastigmatic myopes. The shifts are consistent with a bias towards vertical and horizontal retinal blur in WTR and ATR astigmats, respectively, indicating adaptation to native astigmatism.The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement n. [ERC-2011- AdC 294099]. This study was supported by grants FIS2011-24637 to SM and a collaborative research project funded by Essilor International. Optometric examinations were performed in the Faculty of Optometry Clinic of the University Complutense de Madrid (Madrid, Spain). GM and MH work for Essilor International.Peer Reviewe

Desequilíbrio muscular dos flexores e extensores do joelho associado ao surgimento de lesão musculoesquelética relacionada à corrida: um estudo de coorte prospectivo

ResumoO objetivo deste estudo foi verificar se o desequilíbrio dos músculos do joelho pode estar associado com o surgimento de lesões em corredores. Vinte corredores fizeram uma avaliação isocinética nas velocidades de 60, 180 e 300o/s e foram acompanhados por três meses para verificar a ocorrência de lesões. Quatro atletas (21%) apresentaram lesões que envolveram a região do joelho e o desequilíbrio muscular encontrado foi associado ao surgimento de lesões, nas três velocidades testadas (p<0,05).AbstractThe aim of this study was to determine whether a muscle imbalance of the knee is associated with running injuries. Twenty runners were evaluated by an isokinetic dynamometer at 60, 180 and 300 degrees/second. Runners were followed for three months to determine the incidence of injuries. We used the chi‐square test to verify the association between muscular imbalance and the appearance of injury. Four athletes experienced injuries (21%), all registered in the knee. Muscle imbalance was associated with running‐related injuries for the three tested velocities (p<0.05). To conclude, a muscle imbalance may be associated with running injuries