Complimentary Image Processing Techniques: Critical Review with C#

Image Enhancement is one of the most essential and laborious techniques in image researches. The scheme of image enhancement is to improve the visual semblance of an image, or to afford a “correct transform representation for future automated image processing. Many images like medical images, satellite images, aerial images and even real life photographs suffer from indigent contrast and noise. It is necessary to enhance the contrast and remove the noise to enhance image quality. One of the most significant stages in medical images detection and analysis is Image Enhancement techniques which improves the quality (clearness) of images for human look, removing blurring and noise, increasing contrast, and unveil details are examples of enhancement operations. The enhancement technique varies from one field to another according to its objective. The existent techniques of image enhancement can be classified into two categories: Spatial Domain and Frequency domain enhancement. In this research, we present an overview of image enhancement projection techniques in spatial domain. More specifically, we categorise processing methods based typical techniques of Image enhancement. Thus the contribution of this paper is to arrange and review image enhancement procedure techniques, attempt an evaluation of shortcomings and universal needs in this field of active research and in last we will stage out promising directions on research for image enhancement for prospective research. Keywords: Frequency based domain enhancement, Image Enhancement, Spatial based domain enhancement, Histogram Equalization

Measuring light scattering and absorption in corals with Inverse Spectroscopic Optical Coherence Tomography (ISOCT): a new tool for non-invasive monitoring

Abstract: The success of reef-building corals for >200 million years has been dependent on the mutualistic interaction between the coral host and its photosynthetic endosymbiont dinoflagellates (family Symbiodiniaceae) that supply the coral host with nutrients and energy for growth and calcification. While multiple light scattering in coral tissue and skeleton significantly enhance the light microenvironment for Symbiodiniaceae, the mechanisms of light propagation in tissue and skeleton remain largely unknown due to a lack of technologies to measure the intrinsic optical properties of both compartments in live corals. Here we introduce ISOCT (inverse spectroscopic optical coherence tomography), a non-invasive approach to measure optical properties and three-dimensional morphology of living corals at micron- and nano-length scales, respectively, which are involved in the control of light propagation. ISOCT enables measurements of optical properties in the visible range and thus allows for characterization of the density of light harvesting pigments in coral. We used ISOCT to characterize the optical scattering coefficient (μs) of the coral skeleton and chlorophyll a concentration of live coral tissue. ISOCT further characterized the overall micro- and nano-morphology of live tissue by measuring differences in the sub-micron spatial mass density distribution (D) that vary throughout the tissue and skeleton and give rise to light scattering, and this enabled estimates of the spatial directionality of light scattering, i.e., the anisotropy coefficient, g. Thus, ISOCT enables imaging of coral nanoscale structures and allows for quantifying light scattering and pigment absorption in live corals. ISOCT could thus be developed into an important tool for rapid, non-invasive monitoring of coral health, growth and photophysiology with unprecedented spatial resolution

Characterization of Saccharomyces cerevisiae pseudohyphal development

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 1994.Includes bibliographical references.by Carlos Joaquí­n Gimeno.Ph.D

Towards Data-Driven Large Scale Scientific Visualization and Exploration

Technological advances have enabled us to acquire extremely large datasets but it remains a challenge to store, process, and extract information from them. This dissertation builds upon recent advances in machine learning, visualization, and user interactions to facilitate exploration of large-scale scientific datasets. First, we use data-driven approaches to computationally identify regions of interest in the datasets. Second, we use visual presentation for effective user comprehension. Third, we provide interactions for human users to integrate domain knowledge and semantic information into this exploration process. Our research shows how to extract, visualize, and explore informative regions on very large 2D landscape images, 3D volumetric datasets, high-dimensional volumetric mouse brain datasets with thousands of spatially-mapped gene expression profiles, and geospatial trajectories that evolve over time. The contribution of this dissertation include: (1) We introduce a sliding-window saliency model that discovers regions of user interest in very large images; (2) We develop visual segmentation of intensity-gradient histograms to identify meaningful components from volumetric datasets; (3) We extract boundary surfaces from a wealth of volumetric gene expression mouse brain profiles to personalize the reference brain atlas; (4) We show how to efficiently cluster geospatial trajectories by mapping each sequence of locations to a high-dimensional point with the kernel distance framework. We aim to discover patterns, relationships, and anomalies that would lead to new scientific, engineering, and medical advances. This work represents one of the first steps toward better visual understanding of large-scale scientific data by combining machine learning and human intelligence

Función de los antiportadores NHX1 y NHX2 de arabidopsis thaliana en la acumulación de potasio en las vacuolas vegetales

Tesis descargada desde TESEOEl potasio (K+) es un macronutriente esencial para las células vegetales y de su alta movilidad dependen el correcto ajuste osmótico responsable de la generación y los cambios de turgencia que dirigen, entre otros procesos, la expansión celular y los movimientos estomáticos. Debido a que la vacuola constituye el mayor reservorio de potasio celular, los flujos de potasio a través del tonoplasto son de gran importancia para el correcto funcionamiento celular y deben estar rigurosamente regulados. La entrada de potasio al interior vacuolar va en contra de su gradiente electroquímico, por tanto se ha sugerido que un antiportador K+/H+ energetizado por un gradiente de pH a través del tonoplasto controlaría la acumulación de K+ vacuolar. En este trabajo, se ha realizado el análisis exhaustivo de la función y regulación de los antiportadores catión/H+ de Arabidopsis AtNHX1 y AtNHX2. Con los resultados obtenidos se concluye que: 1. Las proteínas localizadas en el tonoplasto AtNHX1 y AtNHX2 desempeñan un papel crítico en la acumulación de K+ en la vacuola, que es esencial para la regulación osmótica, la expansión celular y el crecimiento de las plantas; 2. Los transportadores AtNHX1 y AtNHX2 son esenciales para la actividad estomática ya que median la acumulación de K+ en la vacuola de las células guarda; 3. No existen otros transportadores de K+ que sustituyan funcionalmente su función en las células guarda, mientras que la presencia de Na+ parcialmente exime el requerimiento de las proteínas AtNHX1 y AtNHX2; 4. Los cambios morfológicos que se producen en las vacuolas de las células guarda durante los procesos de apertura y cierre estomáticos son incondicionalmente dependientes de la entrada de K+ al lumen vacuolar mediada por las proteínas AtNHX1 y AtNHX2; 5. Las levaduras poseen kinasas capaces de fosforilar al antiportador AtNHX2 en la serina 532, y esta fosforilación es esencial para la actividad de AtNHX2 en levaduras; 6. Los antiportadores AtNHX1 y AtNHX2, que pueden formar homodímeros y heterodímeros entre ellos, interaccionan in planta con diversos miembros de la familia de kinasas CBL-Interacting Protein Kinases (CIPKs)

Focused optical beams for driving and sensing helical and biological microobjects

A novel and interesting approach to detect microfluidic dynamics at a very small scale is given by optically trapped particles that are used as optofluidic sensors for microfluidic flows. These flows are generated by artificial as well as living microobjects, which possess their own dynamics at the nanoscale. Optical forces acting on a small particle in a laser beam can evoke a three dimensional trapping of the particle. This phenomenon is called optical tweezing and is a consequence of the momentum transfer from incident photons to the confined object. An optically confined particle shows Brownian motion in an optical tweezer, but is prevented from long term diffusion. A careful analysis of the motion of the confined particle allows a precise detection of microfluidic flows generated by an artificial or living source in the close vicinity of the particle. Thus, the particle can be used as a sensitive optofluidic detector. For this aim, several optical tweezers at different wavelengths are integrated into a dark-field microscope, combined with a high speed camera, to achieve a precise detection of the motion of the center-of-mass of the trapped particle. With this unique experimental system, a gold sphere is used as an optofluidic nanosensor to analyze for the first time the microfluidic oscillations generated by a biological sample. Here, a freely swimming larva of Copepods serves as the living source of flow. However, even if the trapping laser wavelength is off-resonant to the plasmon resonance of the flow detector, a finite heating of the gold nanoparticle occurs which reduces the sensitivity of detection. To increase the sensitivity of the optofluidic detection, a non-absorbing, dielectric microparticle is introduced as the optofluidic sensor for the microflows. It enables a quantitative, two dimensional mapping of the vectorial velocity field around a microscale oscillator in an aqueous environment. This paves the way for an alternative and sensitive detection approach for the microfluidic dynamics of artificial and living objects at a very small scale. To this aim and as a first step, an optically trapped microhelix serves as a model system for the mechanical and dynamical properties of a living microorganism. An optical tweezer is implemented for initiating a light-driven rotation of the chiral microobject in an aqueous environment and the optofluidic detection of its flow field is established. The method is then adopted for the measurement of the microfluidic flow generated by a biological system with similar dynamics, in this case a bacterium. The experimental approach is used to quantify the time-dependent changes of the flow generated by the flagella bundle rotation at a single cell level. This is achieved by observing the hydrodynamic interaction between a dielectric particle and a bacterium that are both trapped next to each other in a dual beam optical tweezer. This novel experimental technique allows the extraction of quantitative information on bacterial motility without the necessity of observing the bacterium directly. These findings can be of great relevance for an understanding of the response of different strains of bacteria to environmental changes and to discriminate between different states of bacterial activity

XXI Fungal Genetics Conference Abstracts

XXI Fungal Genetics Conference Abstract