An interactive color pre-processing method to improve tumor segmentation in digital medical images

In the last few decades the medical imaging field has grown considerably, and new techniques such as computerized axial tomography (CAT) and Magnetic Resonance Imaging (MRI) are able to obtain medical images in noninvasive ways. These new technologies have opened the medical field, offering opportunities to improve patient diagnosis, education and training, treatment monitoring, and surgery planning. One of these opportunities is in the tumor segmentation field. Tumor segmentation is the process of virtually extracting the tumor from the healthy tissues of the body by computer algorithms. This is a complex process since tumors have different shapes, sizes, tissue densities, and locations. The algorithms that have been developed cannot take into account all these variations and higher accuracy is achieved with specialized methods that generally work with specific types of tissue data. In this thesis a color pre-processing method for segmentation is presented. Most tumor segmentation methods are based on grayscale values of the medical images. The method proposed in this thesis adds color information to the original values of the image. The user selects the region of interest (ROI), usually the tumor, from the grayscale medical image and from this initial selection, the image is mapped into a colored space. Tissue densities that are part of the tumor are assigned an RGB component and any tissues outside the tumor are set to black. The user can tweak the color ranges in real time to achieve better results, in cases where the tumor pixels are non-homogenous in terms of intensity. The user then places a seed in the center of the tumor and begins segmentation. A pixel in the image is segmented as part of the tumor if it\u27s within an initial 10% threshold. This threshold is determined if the seed is within the average RGB values of the tumor, and within the search region. The search region is calculated by growing or shrinking the previous region using the information or previous segmented regions of the set of slices. The method automatically segments all the slices on the set from the inputs of the first slice. All through the segmentation process the user can tweak different parameters and visualize the segmentation results in real time. The method was run on ten test cases several runs were performed for each test cases. 10 out of the 20 test runs gave false positives of 25% or less, and 10 out of the 20 test runs gave false negatives of 25% or less. Using only grayscale thresholding methods the results for the same test cases show a false positive of up to 52% on the easy cases and up to 284% on the difficult cases, and false negatives of up to 14% on the easy cases and up to 99% on the difficult cases. While the results of the grayscale and color pre-processing methods on easy cases were similar, the results of color pre-processing were much better on difficult cases, thus supporting the claim that adding color to medical images for segmentation can significantly improve accuracy of tumor segmentation

Human factors and performance considerations of visual spatial skills in medical context tasks

In the medical field, stereoscopic applications are present in diagnosis, pre-operative planning, minimally invasive surgery, instruction, and training. The use of stereoscopic applications has afforded new ways to interact with patient data, such as immersive virtual environments. This increased usage of stereoscopic applications also raises many basic research questions on human perception and performance. Current studies show mixed results on the benefits of stereoscopic applications with regards to general performance. The benefits depend on the specific task as well as the application domain. The work presented here attempts to answer the general question: How would adding the stereopsis depth cue affect the performance of visual spatial tasks in a medical context? Visual spatial tasks are needed in medicine to understand the relationships between shapes and organs for a variety of activities in patient diagnosis and treatment. The general research question was decomposed into specific hypotheses and three studies were conducted to study them. These studies measured performance of a visual spatial computer task using medical imaging data. Participants assessed the relative positions of three different objects located inside a 3D volumetric representation of a patient\u27s anatomy. The first study consisted of static views and recognition of the position of color objects. The second study consisted of static views using gray objects. The third study consisted of animated views of color objects. In all three studies the task was basically the same: To select which of two objects was closest to a reference object. In all three studies participants were first and second year medical students. Thirty-four participants completed the first study. The results of this study showed some emerging patterns in which the stereoscopic display condition had a positive benefit on performance. The stereoscopic condition had a positive effect on performance for the most difficult cases but did not yield higher results under every case and condition. The second study, completed by 44 participants, showed the stereoscopic condition had a positive benefit on performance in 20 out of the 40 tasks completed. These 40 tasks were divided into four cases, with varying degrees of difficulty, depending on the distances between the objects being judged (i.e. cylinders in this study). At distances between 5-15 mm, the stereoscopic condition yielded statistically significant higher performance. At other distance ranges, while stereopsis showed improvement it was not statistically significant. Thirty-one participants completed the third study. These participants completed a visual spatial task with the addition of an animation to the volume. This allowed the representation to be viewed from multiple angles before the task was completed. Overall the stereoscopic condition had a benefit in performance over the monoscopic condition. As in the previous studies tasks that had the objects between 5 - 15 mm apart had higher performance in the stereoscopic condition. Females performance in the stereoscopic condition was higher and statistically significant than for the monoscopic condition. Participants over 25 years also had a statistically significant higher performance under the stereoscopic condition. It was also observed that the stereoscopic condition did not outperform the monoscopic one in every condition. The results of these studies show that, in general, stereopsis has a positive benefit in performance for visual spatial tasks in medical contexts. This benefit certainly has a relationship with the difficulty of the task as well as age and gender. These initial insights are a step into further work to help generate design guidelines when developing stereoscopic applications

Using Vehicle Dynamics Simulation and Metamodels to Evaluate Factors and Mechanisms Affecting Roll Angle: An Initial Assessment

A rollover is defined as any vehicle rotation of 90 degrees or more about a longitudinal or lateral axis, according to NASS CDS. Rollover crashes are still represented highly in terms of frequency and fatalities when compared to other crash categories. Even though there are various vehicular technical innovations that act as a preventative or protective improvement, rollover crashes and subsequent loss of life and injuries are still prevalent in crash statistics. In 2015, rollovers represented 33% of occupant fatalities. Existing research on rollover as it relates to highway safety is often based on crash data analysis. Limited studies have investigated the initiating mechanisms contributing to vehicular propensity to rollover. Hence, there is a gap in knowledge to understand initiation factors that affect rollover events. Herein, vehicle dynamics simulations will be utilized to examine several vehicle rollover crash scenarios. A second aspect of this research is to develop a metamodel of vehicle roll angle as a function of initiation/influencing factors. A total of 282 vehicle rollover scenarios were created and data from the simulations was used to build metamodels. The vehicle rollover scenarios were split up into 16 categories. The surface metamodel, accuracy model, and global sensitivities were analyzed. These models show that for all the categories, speed had the greatest influence on the vehicle’s propensity to roll over. Friction held a greater influence on the deviation from the centerline of the right lane

Work, Risk and Health: Differences between Immigrants and Natives in Spain

We analyze the impact of working and contractual conditions, particularly exposure to job risks, on the probability of acquiring a disability. We postulate a model in which this impact is mediated by the choice of occupation, with a level of risk associated to it. We assume this choice is endogenous, and that it depends on preferences and opportunities in the labour market, both of which may differ between immigrants and natives. To test this hypothesis we use data from the Continuous Sample of Working Lives of the Spanish SS system. It contains individual, job and firm information of over a million workers, including a representative sample of immigrants. We find that risk exposure increases the probability of permanent disability by 5.3%; temporary employment also influences health. Migrant status – with differences among regions of origin – significantly affects both disability and the probability of being employed in a risky occupation. Most groups of immigrants work in riskier jobs, but have lower probability of becoming disabled. Nevertheless, our theoretical hypothesis that disability and risk are jointly determined is not valid for immigrants: i.e. for them working conditions is not a matter of choice in terms of health.disability, working conditions, immigration, Spain, MCVL

Valoración socio-cultural de los servicios ecosistémicos como acción estratégica de educación ambiental, en la comunidad de Las Tejas No. 1 del municipio de Matagalpa, durante el segundo semestre del año 2016

El presente trabajo de investigación tiene como tema “Valoración socio-cultural de los servicios ecosistémicos como acción estratégica de educación ambiental, en el departamento de Matagalpa, durante el 2016” y el Subtema “Valoración socio-cultural de los servicios ecosistémicos como acción estratégica de educación ambiental, en la comunidad Las Tejas No.1 del municipio de Matagalpa, departamento de Matagalpa, durante el segundo semestre del año 2016”, con el propósito de valorar aspectos socioculturales de los servicios ecosistémicos como estrategia de educación ambiental. Para realizar objetivamente este estudio de los servicios ecosistémicos presentes en la comunidad se trabajó con una muestra poblacional de 52 pobladores. Permitiendo analizar los factores socioculturales que influyen en los servicios ecosistémicos. Esta identificación se realizó a través de un análisis teórico y la aplicación de instrumentos como encuesta, entrevista y grupo focal a los actores sociales. Los resultados destacan que uno de los servicios ecosistémicos más importantes en el área de estudio es el agua que pertenece a los servicios de aprovisionamiento. Con las técnicas utilizadas se comprobó que la valoración sociocultural de los servicios ecosistémicos es de gran importancia para los pobladores por el valor de los servicios que los ecosistemas prestan para el beneficio de las personas y cómo esos valores se integran en la toma de decisiones para su conservación o uso sostenible. Palabras claves: valoración sociocultural, servicios ecosistémicos, educación ambiental

PENGARUH PEMANFAATAN TEKNOLOGI INFORMASI TERHADAP KINERJA KARYAWAN (Suatu Studi Pada PUSAT SAINS & TEKNOLOGI NUKLIR TERAPAN (PSTNT) Badan Tenaga Nuklir Nasional (Batan) Bandung)

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Sobre la Clonación de Mascotas Ven y Deb-ATE: Una propuesta pedagógica y didáctica para el fortalecimiento del pensamiento crítico y deliberativo

El presente artículo, producto de la investigación de maestría titulada “Actividades Tecnológicas Escolares y Formación de Sujetos. Significados y Relaciones. Aproximación Teórica y Práctica”, presenta uno de los resultados de los objetivos de dicha investigación, correspondiente al diseño e implementación de una propuesta pedagógica y didáctica, la cual se denomina “Sobre la clonación de mascotas ven y deb-ATE”. Ésta propuesta, es una Actividad Tecnológica Escolar, fundamentada en aspectos de la educación en ciencia, tecnología y sociedad, y en las habilidades comunes del pensamiento crítico y deliberativo como lo son: la argumentación, la participación, la toma de decisiones, la defensa de los puntos de vista y la solución de problemas. La metodología de trabajo sobre la cual se diseña la actividad, se hace a partir del caso simulado y el debate argumentado; técnicas utilizadas en la educación en ciencia, tecnología y sociedad y en el fomento del pensamiento. Por otro lado, dicha actividad, fue implementada con estudiantes de quinto grado de primaria del colegio Marruecos y Molinos de la localidad de Rafael Uribe Uribe y los resultados se orientan en dos vías, la primera corresponde a los logros alcanzados durante el fomento de las habilidades de pensamiento ya mencionadas, y la segunda a la valoración de la actividad

Implicaciones de la asociación de nodricismo sobre la biología reproductiva y establecimiento de nuevos individuos, de Mammillaria carnea

Mammillaria carnea Zucc. ex Pfeiff. es una cactácea globosa que se distribuye en los estados de Oaxaca, y Puebla, se sabe que presenta asociación de nodricismo y que al igual que para otras cactáceas su establecimiento se encuentra relacionado con dicha interacción. En esta interacción la planta nodriza provee de condiciones microclimaticas que protegen a la planta protegida frente a las condiciones ambientales que serían más severas si no se presentara esta interacción, posibilitando así el establecimiento y crecimiento de los individuos. No obstante algunos individuos pueden encontrarse en espacios sin protección de la nodriza, por esta razón en el presente trabajo se aborda la interacción nodrizaprotegido y planta-polinizador durante la etapa reproductiva de Mammillaria carnea, y al inicio del ciclo de vida la planta, mediante pruebas de germinación, y tiene como objetivo determinar si la condición de asociación de nodricismo o sin nodriza, tiene efectos sobre las estrategias que las plantas poseen para la reproducción sexual exitosa y establecimiento exitoso. En este trabajo se evaluó la germinación, fenología reproductiva y caracteres florales, además de la frecuencia y duración de visitantes florales, de individuos de M. carnea que presentan o no asociación con P. laevigata. Se encontró que la condición en la que se encuentran los individuos de M. carnea tiene efectos sobre biología reproductiva de esta especie.Mammillaria carnea Zucc. Ex Pfeiff. is a globose cactus that is distributed in the states of Oaxaca and Puebla. It is known to have facilitation with shrubby species and that as for other cacti their establishment is related to this interaction. In the interaction, the nurse plant provides microclimatic conditions that protect protege against severe environmental conditions, thus enabling the establishment and growth of individuals. Nevertheless, some individuals can be found in spaces without protection of the nurse, and therefore the purpose of this research is to determine if the nurse-protege interaction has any effect on the reproductive success and successful establishment. Towards this end, germination, reproductive phenology and floral traits were evaluated, in addition to the frequency and duration of floral visitors of M. carnea individuals with and without association with P. laevigata. The condition in which the individuals of M. carnea are found had effects on the reproductive biology of this species

Niveles de Colinesterasa sérica en agricultores expuestos a plaguicidas, del caserío Llícuar, (abril- noviembre), Sechura-2018

El presente proyecto de estudio titulado, \\"Niveles de colinesterasa sérica en agricultores expuestos a plaguicidas, del caserío Llícuar, (abril - noviembre), Sechura-2018\\"; cuyo objetivo fue determinar los niveles de colinesterasa sérica que presentan los pobladores agrícolas expuestos a plaguicidas del Caserío Llícuar; para ello, se utilizó como metodología una investigación de tipo descriptiva y de diseño no experimental, transversal. La población de estudio estuvo conformada por los pobladores agrícolas del caserío Llícuar?Distrito de Rinconada Llícuar-Sechura, cuyo número es de 800 habitantes y su muestra estuvo conformada por 30 pobladores agrícolas. Para la recolección de los datos se empleó las técnicas de la Observación y la Encuesta, con sus instrumentos de: Ficha Técnica de observación de campo y de laboratorio y el Cuestionario, respectivamente. Para el análisis de sangre y determinación de los niveles de colinesterasa sérica, se hará uso del Método Cinético a 405 nm para la determinación de Colinesterasa en Plasma por Espectrofotometría. Los datos recogidos fueron analizados y procesados a través de tablas de tabulación, tablas de frecuencia y gráficos estadísticos, haciendo usos del paquete informático estadístico SPSS. Los resultados obtenidos fueron confiables, porque nos permitió dar conclusiones científicamente probadas y así enfrentar este problema de salud pública.Tesi