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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Design, Fabrication and Functional Analysis of a New Protein Array Based on ssDNA-based Assembly

Ajikumar, Parayil Kumaran, Ng, Jin Kiat, Tang, Yew Chung, Lee, Jim Yang, Stephanopoulos, Gregory, Too, Heng-Phon 01 1900 (has links)
In the post genomic era, proteomics has enormous potential in biology and medicine. Among the various bioanalytical tools developed, protein microarray is one of the recent advancements which offer high throughput profiling of cellular proteins to provide insights into the mechanisms of biological processes. Fundamentally, the protein microarray involves the immobilization of interacting elements, proteins, on a few square microns of a solid support and in principle, it is capable of detecting analytes with a higher sensitivity than conventional macroscopic immunoassays. Here in the present report we delineates the design, fabrication and functional analysis of protein microarray using semi-synthetic ssDNA tagged-proteins as capturing moiety as well as address on a solid support. Optimization of the platform has been carried out by investigating various parameters such as surface chemistry, signal amplification, and conditions for homogenous liguid phase protein-protein interaction. / Singapore-MIT Alliance (SMA)
12

A função logaritmo e a régua de cálculo / The logarithm function and the slide rule

Tania Cristina Maggioni Pippa 17 March 2014 (has links)
No início do século XVII, o escocês John Napier revolucionou os métodos de cálculo da época com a invenção dos logaritmos. O logaritmo de Napier não era exatamente o que usamos hoje. Naquela época, o trabalho de multiplicação, divisão, cálculo de potências e extração de raízes eram trabalhosos e feitos a partir de senos. Surgiram as primeiras tábuas de logaritmos, inventadas independentemente por John Napier (1550-1617) e Jost Bürgi (1552-1632). Pouco depois, Henry Briggs (1561-1631) aperfeiçoou essas tábuas, apresentando os logaritmos decimais. A contribuição fundamental dos logaritmos é a de facilitar os cálculos através da transformação de operações de multiplicação em adição e de operações de divisão em subtração. Essas transformações foram de grande importância nos cálculos trabalhosos que estavam envolvidos em Astronomia e Navegação. Em 1632, um matemático inglês chamado William Oughtred inventou a régua de cálculo, com base na \"Tábua de Napier\". Esse foi um grande passo em direção à calculadora e à construção dos computadores. Nesse trabalho propomos a utilização da régua de cálculo no ensino das propriedades dos logaritmos. Para tanto, foram estudados tópicos como a história dos logaritmos, a função logaritmo, a caracterização das funções logarítmicas, a associação de logaritmos a progressões aritméticas e geométricas e o uso de uma régua de cálculo / In the early seventeenth century, the Scotsman John Napier revolutionized the calculation methods of that time with the invention of logarithms. The Napier logarithm was not exactly the same as we use now. At that time, the multiplication, division, exponents calculation and extracting roots were demanded extensive labor. John Napier (1550-1617) and Jost Bürgi (1552-1632) invented independently the first logarithm tables. Shortly after, Henry Briggs (1561-1631) improved these boards, presenting the decimal logarithms. The main contribution of logarithms is to make calculations easier by transforming multiplication operations into addition ones and division operations into subtraction ones. These changes have been of great importance in laborious calculations that involved Astronomy and Navigation. In 1632, an English mathematician called William Oughtred invented the slide ruler, based on the \"Napier board\". This was a big step towards the invention of the calculator and the computer. In this work we propose the use of the slide ruler in teaching the properties of logarithms. Thus, topics such as the history of logarithms, the logarithm function, the characterization of logarithmic functions, the association of the logarithms with arithmetical and geometrical progressions, and the use of a slide ruler were studied
13

Mitotic Cell Detection in H&E Stained Meningioma Histopathology Slides

Huiwen Cheng (8090174) 14 January 2021 (has links)
<p>Meningioma represent more than one-third of all primary central nervous system (CNS) tumors,and it can be classified into three grades according to WHO (World Health Organization) in terms of clinical aggressiveness and risk of recurrence. A key component of meningioma grades is the mitotic count, which is defined as quantifying the number of cells in the process of dividing (i.e., undergoing mitosis) at a specific point in time. Currently, mitosis counting is done manually by a pathologist looking at 10 consecutive high-power fields (HPF) on a glass slide under a microscope, which is an extremely laborious and time-consuming process. The goal of this thesis is to investigate the use of computerized methods to automate the detection of mitotic nuclei with limited labeled data.We built computational methods to detect and quantify the histological features of mitotic cells on a whole slides image which mimic the exact process of pathologist workflow. Since we do not have enough training data from meningioma slide, we learned the mitotic cell features through public available breast cancer datasets, and predicted on meingioma slide for accuracy. We use either handcrafted features that capture certain morphological, statistical, or textural attributes of mitoses or features learned with convolutional neural networks (CNN). Hand crafted features are inspired by the domain knowledge, while the data-driven VGG16models tend to be domain agnostic and attempt to learn additional feature bases that cannot be represented through any of the handcrafted features. Our work on detection of mitotic cells shows 100% recall, 9% precision and 0.17 F1 score. The detection using VGG16performs with 71% recall, 73% precision, and 0.77 F1 score.Finally, this research of automated image analysis could drastically increase diagnostic efficiency and reduce inter-observer variability and errors in pathology diagnosis, which would allow fewer pathologists to serve more patients while maintaining diagnostic accuracy and precision. And all these methodologies will increasingly transform practice of pathology, allowing it to mature toward a quantitative science.</p>
14

Identifying the Vulnerability of Earthen Levees to Slump Slides using Geotechnical and Geomorphological Parameters

Sehat, Sona 13 December 2014 (has links)
The main goal of this research is to investigate vulnerability of levees to future slump slides. In the first part, polarimetric synthetic aperture radar (PolSAR) imagery is used as input in an automated classification system for characterizing areas on the levee having anomalies. In addition, a set of in-situ soil data is collected to provide detailed soil properties over the study area. In-situ soil properties of different classes characterized by the classifier are analyzed to determine how similarities between different areas. The second part, a database including of 34 slump slides that occurred in the lower Mississippi River levee system over a period of two years is used. The impacts of rainfall as well as several spatial geometrical and geomorphological variables (including channel width, river sinuosity index, riverbank erosion, channel shape condition and distance to river) are analyzed and tested for significance and used for developing a logistic regression model.
15

A Study of Sporulation and Spore Germination in Two-Spored Yeasts

Grewal, Narinder Singh January 1971 (has links)
Nuclear divisions during sporulation of 15 predominantly two-spored and 2 predominantly four-spored yeasts were followed by Giemsa staining and light microscopy. The number of nuclei present per ascus was related to the presence or absence of conjugation at the time of germination of the spores. Plating experiments and a modification of the Finder Slide technique were used to determine whether progeny cells that developed from single spores of 2 two-spored and one four-spored strain could sporulate. The ploidy of these yeasts at different stages of their life cycles was estimated by DNA extractions. The spores of the two-spored yeasts were very difficult to separate following removal of their ascus walls, and electron microscopy was employed in an attempt to account for this. / Thesis / Master of Science (MSc)
16

Deep Autofocusing for Digital Pathology Whole Slide Imaging

Li, Qiang January 2024 (has links)
The quality of clinical pathology is a critical index for evaluating a nation's healthcare level. Recently developed digital pathology techniques have the capability to transform pathological slides into digital whole slide images (WSI). This transformation facilitates data storage, online transmission, real-time viewing, and remote consultations, significantly elevating clinical diagnosis. The effectiveness and efficiency of digital pathology imaging often hinge on the precision and speed of autofocusing. However, achieving autofocusing of pathological images presents challenges under constraints including uneven focus distribution and limited Depth of Field (DoF). Current autofocusing methods, such as those relying on image stacks, need to use more time and resources for capturing and processing images. Moreover, autofocusing based on reflective hardware systems, despite its efficiency, incurs significant hardware costs and suffers from a lack of system compatibility. Finally, machine learning-based autofocusing can circumvent repetitive mechanical movements and camera shots. However, a simplistic end-to-end implementation that does not account for the imaging process falls short of delivering satisfactory focus prediction and in-focus image restoration. In this thesis, we present three distinct autofocusing techniques for defocus pathology images: (1) Aberration-aware Focal Distance Prediction leverages the asymmetric effects of optical aberrations, making it ideal for focus prediction within focus map scenarios; (2) Dual-shot Deep Autofocusing with a Fixed Offset Prior is designed to merge two images taken at different defocus distances with fixed positions, ensuring heightened accuracy in in-focus image restoration for fast offline situations; (3) Semi-blind Deep Restoration of Defocus Images utilizes multi-task joint prediction guided by PSF, enabling high-efficiency, single-pass scanning for offline in-focus image restoration. / Thesis / Doctor of Philosophy (PhD)
17

The Integration of the Brain Bank Imaging Workflow into the Infrastructure of the Multiple Sclerosis Research Network

Svanadze, Lika 27 February 2019 (has links)
No description available.
18

Light-Controlled Mechanically Interlocked Molecules and Materials

Boelke, Jan 28 March 2024 (has links)
Im Zusammenhang mit auf Reize reagierenden Materialien ist Licht aufgrund seiner hohen räumlichen und zeitlichen Auflösung von besonderer Bedeutung. Hierfür können molekulare Photoschalter, wie z.B. Azobenzole, in das Material eingebaut werden, um eine Reaktion auf Lichteinstrahlung von der molekularen auf die makroskopische Ebene zu übertragen. Fortschrittliche Moleküldesigns, wie z.B. Ortho-Fluorierung, führen dabei zu hervorragenden bistabilen Photoschaltern, die in Kombination mit Cyclodextrinen (CDs) als supramolekulare Bausteine eine Vielfalt an lichtempfindlichen Materialien ermöglichen. Um ein grundlegendes Verständnis der Wechselwirkungen von ortho-Fluorazobenzolen (FAzos) mit CDs zu erlangen, wurde in Kapitel II deren supramolekulare Wirt-Gast-Komplexierung untersucht. Hierbei konnte eine veränderte Barriere des Auffädelns der CDs beobachtet werden. Durch detaillierte Untersuchungen an polymeren Modellverbindungen in Kapitel III konnte gezeigt werden, dass das Auffädeln über die Z- im Vergleich zu den E-Isomeren der FAzos deutlich reduziert ist und dadurch die Bildung von Pseudo-Polyrotaxanen durch Bestrahlung mit Licht kontrolliert werden kann. Durch speziell konzipierte DOSY-Experimente konnte die Abfädelungskinetik aus Polyrotaxanen, bei denen die CDs durch das Z-Azobenzol auf der Achse fixiert wurden, verfolgt werden. Somit konnte gezeigt werden, dass eine Kontrolle der Bewegung von CDs durch Licht möglich ist. Auf Grundlage dieser Ergebnisse wurden in Kapitel IV neuartige lichtempfindliche Slide-Ring Materialien entwickelt, die bei Lichteinstrahlung eine reversible Änderung ihrer Steifigkeit aufweisen. Die Materialien wurden so konzipiert, dass sie ortho-Fluorazobenzole enthalten, die als durch Licht schaltbare Barrieren für das Gleiten von CDs entlang des Polymerrückgrats dienen. Hierdurch konnte eine reversible Änderung des Elastizitätsmoduls durch Bestrahlung mit Licht erzielt werden und somit ein erfolgreicher Konzeptnachweis erbracht werden. / In the context of stimuli-responsive materials, light is of particular importance due to its high spatial and temporal resolution. For this purpose, molecular photoswitches, such as azobenzenes, can be incorporated into the material to transfer a response to light irradiation from the molecular to the macroscopic level. Advanced molecular designs, such as ortho-fluorination, lead to excellent bistable photoswitches which, in combination with cyclodextrins (CDs) as supramolecular building blocks, enable a variety of light-responsive materials. To gain a fundamental understanding of the interactions of ortho-fluoroazobenzenes (FAzos) with CDs, their supramolecular host-guest complexation was investigated in Chapter II. An altered barrier for the threading of CDs was thereby observed. Detailed studies on polymeric model compounds in Chapter III showed that threading over the Z-isomers of the FAzos is significantly reduced compared to the E-isomers and that the formation of pseudo-polyrotaxanes can thus be controlled by irradiation with light. Using specially designed DOSY experiments, the threading kinetics from polyrotaxanes, in which the CDs where fixed on the axis by the Z-azobenzene, could be followed. This showed that it is possible to control the movement of CDs by light. Based on these results, novel photoresponsive slide-ring materials were developed in Chapter IV, which exhibit a reversible change in stiffness when exposed to light. The materials were designed to contain ortho-fluoroazobenzenes, which serve as photoswitchable barriers for the sliding of CDs along the polymer backbone. This enabled a reversible change of the elastic modulus to be accomplished by irradiation with light, thus providing a successful proof of concept.
19

Moderní tréninkové pomůcky pro lední hokej / Modern training equipmens for ice hockey

Křepelka, Jonáš January 2014 (has links)
Title of work: Modern training equipmens for ice hockey Goal of work: Using standardized interviews to determine the frequency of use of modern hockey equipment abroad, then through a questionnaire survey, the frequency and the current status of the use of modern hockey equipment for ice hockey players aged 12-13 years in the Czech Republic. According to the findings recommend examples of training exercises that are suitable for the development of skills for players to prepare for the ice and off the ice. Method: Observation, indirect observation, document analysis, questionnaire survey, data analysis, standardized interview. Results: The results of the thesis we have shown that the frequency and condition using modern training aids for ice hockey in the Czech Republic compared to other countries at a low level. Some tools are used by us all. 40% of those surveyed teams in our equipment in use. On this basis, I recommend examples of training exercises with the use of modern equipment for ice hockey, and I brought a few suggestions on how to properly work with modern tools. Keywords: Ice Hockey, Skating, Stickhandling, Equipmens, Slide Board, Passmaster, Attack triangle, SweetHands
20

Musikaliskt lärande : Musikers syn på sitt musikaliska lärande

Ekström, Simon January 2014 (has links)
Syftet med detta arbete har varit att undersöka hur musiker inom den afroamerikanska musiktraditionen ser på sitt musikaliska lärande. Deltagarna har haft olika musikaliska bakgrunder så som låtskrivare, frilansmusiker och instrumentallärare. Undersökningen tar sin teoretiska utgångspunkt ur ett kulturpsykologsikt perspektiv där synen på lärande ses som en process som utvecklas mellan individer i en lokalt rådande kultur. Informanterna har i undersökning fått prova att spela lap steel och dobro i fyra olika stämningar som därefter avslutats med en intervju. Vid dessa tillfällen har deltagarna reflekterat och delat med sig av sina åsikter och erfarenheter som berör deras musikaliska lärande.Resultatet av undersökningen pressenteras i tre kategorier som jag i detta arbete kallar för, det speltekniska perspektivet, gehöret och det visuella lärandet samt det musikaliska uttrycket. Dessa tre kategorier återspeglar vilka parametrar informanterna intagit och redogjort för när de reflekterat över sitt musikaliska lärande. Undersökning visar i detta på en nyansrikedom som berör musikaliskt lärande där både likheter och olikheter bland de medverkande informanterna redovisas.

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