Image enhancement techniques applied to solar feature detection

This dissertation presents the development of automatic image enhancement techniques for solar feature detection. The new method allows for detection and tracking of the evolution of filaments in solar images. Series of H-alpha full-disk images are taken in regular time intervals to observe the changes of the solar disk features. In each picture, the solar chromosphere filaments are identified for further evolution examination. The initial preprocessing step involves local thresholding to convert grayscale images into black-and-white pictures with chromosphere granularity enhanced. An alternative preprocessing method, based on image normalization and global thresholding is presented. The next step employs morphological closing operations with multi-directional linear structuring elements to extract elongated shapes in the image. After logical union of directional filtering results, the remaining noise is removed from the final outcome using morphological dilation and erosion with a circular structuring element. Experimental results show that the developed techniques can achieve excellent results in detecting large filaments and good detection rates for small filaments. The final chapter discusses proposed directions of the future research and applications to other areas of solar image processing, in particular to detection of solar flares, plages and sunspots

Semiclassical Analysis of Constrained Quantum Systems

Exact procedures that follow Dirac's constraint quantization of gauge theories are usually technically involved and often difficult to implement in practice. We overview an "effective" scheme for obtaining the leading order semiclassical corrections to the dynamics of constrained quantum systems developed elsewhere. Motivated by the geometrical view of quantum mechanics, our method mimics the classical Dirac-Bergmann algorithm and avoids direct reference to a particular representation of the physical Hilbert space. We illustrate the procedure through the example of a relativistic particle in Minkowski spacetime.Comment: 8 pages, Proceedings of "The Planck Scale" (XXV Max Born Symposium, Wroclaw

Neural Correlates of Cognitive-Attentional Syndrome: An fMRI Study on Repetitive Negative Thinking Induction and Resting State Functional Connectivity

AimCognitive-attentional syndrome (CAS) is the main factor underlying depressive and anxiety disorders in the metacognitive approach to psychopathology and psychotherapy. This study explore neural correlates of this syndrome during induced negative thinking, abstract thinking, and resting states.Methodsn = 25 people with high levels of CAS and n = 33 people with low levels of CAS were chosen from a population-based sample (N = 1225). These groups filled-in a series of measures of CAS, negative affect, and psychopathology; they also underwent a modified rumination induction procedure and a resting state fMRI session. Resonance imaging data were analyzed using static general linear model and functional connectivity approaches.ResultsThe two groups differed with large effect sizes on all used measures of CAS, negative affect, and psychopathology. We did not find any group differences in general linear model analyses. Functional connectivity analyses showed that high levels of CAS were related to disrupted patterns of connectivity within and between various brain networks: the default mode network, the salience network, and the central executive network.ConclusionWe showed that low- and high-CAS groups differed in functional connectivity during induced negative and abstract thinking and also in resting state fMRI. Overall, our results suggest that people with high levels of CAS tend to have disrupted neural processing related to self-referential processing, task-oriented processing, and emotional processing

Zależność pomiędzy wartościami stężeń kwasów żółciowych w surowicy krwi ciężarnych kobiet z cholestazą wewnątrzwątrobową a stanem noworodka po urodzeniu

Objectives: The aim of the study was to determine a relation between the level of total serum bile acids in pregnant women and the condition of their newborns on the basis of select parameters of acid-base balance in the cord blood. Material and methods: The study group consisted of 64 pregnant women with Intrahepatic Cholestasis of Pregnancy and 78 healthy pregnant women constituted the control group. Colorimetric enzymatic measurements of serum total bile acids were performed in both groups. Results: In the mild cholestasis group, mean concentration of bile acids amounted to 20.6 +/- 1.0 μmol/l and was statistically significantly lower as compared to women with severe cholestasis (58.9 +/- 9.5 μmol/l). In the control group, mean concentration of bile acids was 4.1 +/-0.3 μmol/l and was statistically significantly lower as compared to groups with cholestasis. Caesarean section was performed in 60.9% of women with cholestasis as compared to 19.2% of controls. Also, neonatal condition in the first minute of life was worse in the group with cholestasis as compared to the infants in the control group. The body weight of newborns of mothers with cholestasis was statistically significantly lower than in infants born to controls. Lowered neonatal pH (below 7.20) was noted in 2.6% of the newborns from the control group and was statistically significantly less frequent as compared to infants from the group with cholestasis. Conclusions: Periodic measurements of total bile acid concentrations in serum of pregnant women with cholestasis is of high value in establishing the diagnosis and determining severity of the disease in the mother, as well as potential hazard for the fetus. Simultaneous monitoring of the changes total bile acids concentrations in the blood serum and the well-being allows to reduce the rates of neonatal distresses after birth and cesarean sections.Cel pracy: Celem pracy jest ustalenie zależności pomiędzy stężeniami całkowitych kwasów żółciowych w surowicy krwi ciężarnych a stanem urodzeniowym noworodka ocenionym na podstawie wybranych parametrów równowagi kwasowo-zasadowej w krwi pępowinowej. Materiał i metody: Grupę badaną stanowiły 64 ciężarne z cholestazą wewnątrzwątrobową, grupę kontrolną 78 zdrowych ciężarnych. W obu grupach oznaczano stężenia całkowite kwasów żółciowych, które wykonywano kolorymetrycznie stosując testy enzymatyczne. Wyniki: W grupie badanej z łagodną cholestazą średnie stężenie kwasów żółciowych wyniosło 20,6+/-1,0 μmol/l i było znamiennie statystycznie niższe niż dla kobiet z ciężką cholestazą (58,9+/-9,5 μmol/l). W grupie kontrolnej średnia wartość stężenia kwasów żółciowych wyniosła 4,1+/-0,3 μmol/l i była znamiennie statystycznie niższa niż dla grup z cholestazą. Cięcie cesarskie wykonano u 60,9% z cholestazą w porównaniu do 19,2% w grupie kontrolnej. W grupie ciężarnych z cholestazą stwierdzono gorszy stan po urodzeniu noworodków w 1 minucie życia w porównaniu do grupy kontrolnej. Masa ciała noworodków matek z cholestazą była znamiennie statystycznie niższa niż w grupie kontrolnej. Obniżenie urodzeniowego pH poniżej 7,20 wystąpiło u 2,6% noworodków z grupy kontrolnej i wystąpiło znamiennie rzadziej niż w grupach badanych z cholestazą. Wnioski: Cykliczne oznaczenia stężeń całkowitych kwasów żółciowych w surowicy krwi ciężarnych z cholestazą ma wysoką wartość praktyczną w rozpoznaniu, ocenie stopnia ciężkości schorzenia u matki oraz określeniu potencjalnego zagrożenia dla płodu w przebiegu choroby. Jednoczasowe monitorowanie zmian stężeń całkowitych kwasów żółciowych w surowicy krwi oraz dobrostanu pozwala na zmniejszenie odsetka ciężkich stanów noworodków po urodzeniu i odsetka cięć cesarskich

Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

Fluorescent pyrene–linker–nucleobase (nucleobase = thymine, adenine) conjugates with carbonyl and hydroxy functionalities in the linker were synthesized and characterized. X-ray single-crystal structure analysis performed for the pyrene–C(O)CH2CH2–thymine (2) conjugate reveals dimers of molecules 2 stabilized by hydrogen bonds between the thymine moieties. The photochemical characterization showed structure-dependent fluorescence properties of the investigated compounds. The conjugates bearing a carbonyl function represent weak emitters as compared to compounds with a hydroxy function in the linker. The self-assembly properties of pyrene nucleobases were investigated in respect to their binding to single and double strand oligonucleotides in water and in buffer solution. In respect to the complementary oligothymidine T10 template in water, compounds 3 and 5 both show a self-assembling behavior according to canonical base–base pairing. However, in buffer solution, derivative 5 was much more effective than 3 in binding to the T10 template. Furthermore the adenine derivative 5 binds to the double-stranded (dA)10–T10 template with a self-assembly ratio of 112%. Such a high value of a self-assembly ratio can be rationalized by a triple-helix-like binding, intercalation, or a mixture of both. Remarkably, compound 5 also shows dual staining pattern in living HeLa cells. Confocal microscopy confirmed that 5 predominantly stains mitochondria but it also accumulates in the nucleoli of the cells

AVALIAÇÃO DO EFEITO DA AREIA DE FUNDIÇÃO NAS PROPRIEDADES MECÂNICAS DO CONCRETO

A indústria é o segmento de mercado responsável pelo maior consumo de recursos naturais. Sendo assim, há um desafio em otimizar essa relação que envolve a preservação ambiental e o desenvolvimento tecnológico. Em paralelo, a indústria da construção civil apresenta uma grande potencialidade em incorporar esses resíduos nos materiais de construção. Considerando a problemática da pesquisa, é proposto neste artigo, avaliar as propriedades mecânicas do concreto com a substituição parcial do agregado miúdo por areia descartada de fundição (ADF). Para isso, o trabalho experimental está principalmente direcionado a avaliar a resistência à tração, compressão e o módulo de elasticidade estático e dinâmico de concretos com diferentes teores de ADF e diferentes idades. Os resultados obtidos para a mistura com substituição de 20% do agregado miúdo, demonstram uma redução nominal pouco expressiva na resistência mecânica em relação ao concreto de referência. Desta forma, como substituta do agregado miúdo, a areia descartada de fundição (ADF) apresentou um desempenho considerável em suas propriedades mecânicas. E desde que atenda aos requisitos mínimos de durabilidade, demonstra ser uma alternativa válida nas misturas de concreto

AVALIAÇÃO DO EFEITO DA AREIA DE FUNDIÇÃO NAS PROPRIEDADES MECÂNICAS DO CONCRETO

A indústria é o segmento de mercado responsável pelo maior consumo de recursos naturais. Sendo assim, há um desafio em otimizar essa relação que envolve a preservação ambiental e o desenvolvimento tecnológico. Em paralelo, a indústria da construção civil apresenta uma grande potencialidade em incorporar esses resíduos nos materiais de construção. Considerando a problemática da pesquisa, é proposto neste artigo, avaliar as propriedades mecânicas do concreto com a substituição parcial do agregado miúdo por areia descartada de fundição (ADF). Para isso, o trabalho experimental está principalmente direcionado a avaliar a resistência à tração, compressão e o módulo de elasticidade estático e dinâmico de concretos com diferentes teores de ADF e diferentes idades. Os resultados obtidos para a mistura com substituição de 20% do agregado miúdo, demonstram uma redução nominal pouco expressiva na resistência mecânica em relação ao concreto de referência. Desta forma, como substituta do agregado miúdo, a areia descartada de fundição (ADF) apresentou um desempenho considerável em suas propriedades mecânicas. E desde que atenda aos requisitos mínimos de durabilidade, demonstra ser uma alternativa válida nas misturas de concreto

Gold-Induced Desulfurization in a Bis(ferrocenyl) Alkane Dithiol

Thiol-modified ferrocenes on gold have been archetypical model systems for many fundamental charge transfer and other studies, since both thiol-gold and ferrocene redox chemistry are considered to be well-understood. Thus unexpectedly, we found that for a representative of a new class of flexibly linked bis-ferrocenyl compounds, namely, 1-10-bis­(1-ferrocenyl)­decane dithiol, surface immobilization on gold failed. Instead, in the presence of gold, molecular decomposition took place, resulting in sulfur-based adlayers and well-defined molecular elimination products, for which we provide spectroscopic evidence. Careful control experiments and comparison with related ferrocene compounds provide insight into the mechanism of the observed elimination reactions, as a combined effect of the molecular structure and the nature of the gold/sulfur bond. These findings, thus, have a broader impact on the design of molecular adlayers, for example, in the context of surface functionalization in sensing or the synthesis of gold nanoparticles

3D PET image reconstruction based on Maximum Likelihood Estimation Method (MLEM) algorithm

Positron emission tomographs (PET) do not measure an image directly. Instead, they measure at the boundary of the field-of-view (FOV) of PET tomograph a sinogram that consists of measurements of the sums of all the counts along the lines connecting two detectors. As there is a multitude of detectors build-in typical PET tomograph structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Decisive improvement in PET image quality was reached with the introduction of iterative reconstruction techniques. This stage was reached already twenty years ago (with the advent of new powerful computing processors). However, three dimensional (3D) imaging remains still a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines-of-responce (LOR) and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.Comment: 10 pages, 7 figure