991 resultados para linear transformation
Resumo:
PURPOSE: To report the lethal course of malignant transformation of retinoma in an adult. METHODS: Case report. A 40-year-old patient presented with retinoma in his right eye and retinoblastoma in his left eye. Enucleation was recommended but refused and the patient received whole eye radiotherapy elsewhere. Five years later he presented again, with temporal hemianopsia of the left eye secondary to chiasmatic invasion. RESULTS: Diagnosis of retinoblastoma infiltration was confirmed by stereotactic biopsy of the chiasmatic lesion. Treatment with intravenous and intrathecal chemotherapy led to partial remission, and was followed by stereotactic irradiation of the chiasmatic mass and right optic nerve. The left eye was enucleated. Death occurred one year later due to cerebrospinal fluid metastases. CONCLUSION: Extraocular extension of retinoblastoma diagnosed in adulthood has never, to our knowledge, been reported. This case stresses the importance of lifelong retinoma monitoring and the necessity for radical treatment in the event of malignant transformation.
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Microphthalmia with linear skin defects (MLS) syndrome is an X-linked male-lethal disorder also known as MIDAS (microphthalmia, dermal aplasia, and sclerocornea). Additional clinical features include neurological and cardiac abnormalities. MLS syndrome is genetically heterogeneous given that heterozygous mutations in HCCS or COX7B have been identified in MLS-affected females. Both genes encode proteins involved in the structure and function of complexes III and IV, which form the terminal segment of the mitochondrial respiratory chain (MRC). However, not all individuals with MLS syndrome carry a mutation in either HCCS or COX7B. The majority of MLS-affected females have severe skewing of X chromosome inactivation, suggesting that mutations in HCCS, COX7B, and other as-yet-unidentified X-linked gene(s) cause selective loss of cells in which the mutated X chromosome is active. By applying whole-exome sequencing and filtering for X-chromosomal variants, we identified a de novo nonsense mutation in NDUFB11 (Xp11.23) in one female individual and a heterozygous 1-bp deletion in a second individual, her asymptomatic mother, and an affected aborted fetus of the subject's mother. NDUFB11 encodes one of 30 poorly characterized supernumerary subunits of NADH:ubiquinone oxidoreductase, known as complex I (cI), the first and largest enzyme of the MRC. By shRNA-mediated NDUFB11 knockdown in HeLa cells, we demonstrate that NDUFB11 is essential for cI assembly and activity as well as cell growth and survival. These results demonstrate that X-linked genetic defects leading to the complete inactivation of complex I, III, or IV underlie MLS syndrome. Our data reveal an unexpected role of cI dysfunction in a developmental phenotype, further underscoring the existence of a group of mitochondrial diseases associated with neurocutaneous manifestations.
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In this work we study the integrability of a two-dimensional autonomous system in the plane with linear part of center type and non-linear part given by homogeneous polynomials of fourth degree. We give sufficient conditions for integrability in polar coordinates. Finally we establish a conjecture about the independence of the two classes of parameters which appear in the system; if this conjecture is true the integrable cases found will be the only possible ones.
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In this work we study the integrability of two-dimensional autonomous system in the plane with linear part of center type and non-linear part given by homogeneous polynomials of fifth degree. We give a simple characterisation for the integrable cases in polar coordinates. Finally we formulate a conjecture about the independence of the two classes of parameters which appear on the system; if this conjecture is true the integrable cases found will be the only possible ones.
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This thesis addresses the issue of the moving boundaries between family and friends' roles in personal networks, adopting a life-course perspective and using Switzerland as a case study. In a period of major changes in personal life happening in contemporary Western societies, understanding the organization of personal networks intertwined with the unfolding of individual life courses is of prime importance in facing new challenges with regard to social integration. The data stem from a representative national survey carried out in 2011 named Family tiMes, including 803 individuals born either in 1950-1955 or in 1970-1975. An innovative research design was adopted, combing cross-sectional ego-centered network data and retrospective longitudinal life-course data. The results show continuing boundaries between family and friends' roles and that family keeps a prominent role in personal networks despite the notable importance of friendship ties. One relationship stands out above all, that with the partner, followed quite a few steps behind by those with children. Regarding life courses, de-standardization tendencies were found in family formation and also a persistent gendering of occupational trajectories. Two kinds of life trajectories are particularly intertwined with personal networks, co-residence and partnership trajectories, both related to the unfolding of family life. In particular, transition to parenthood functions as a turning point in individuals' lives, deeply transforming their sociability. Finally, a twofold pluralization process was identified, affecting simultaneously the organization of personal networks and the unfolding of individual life courses. This thesis contributes to the literature on the sociology of family and personal life, and to fruitful interlinkage between the network approach and the life-course perspective.
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Background: Design of newly engineered microbial strains for biotechnological purposes would greatly benefit from the development of realistic mathematical models for the processes to be optimized. Such models can then be analyzed and, with the development and application of appropriate optimization techniques, one could identify the modifications that need to be made to the organism in order to achieve the desired biotechnological goal. As appropriate models to perform such an analysis are necessarily non-linear and typically non-convex, finding their global optimum is a challenging task. Canonical modeling techniques, such as Generalized Mass Action (GMA) models based on the power-law formalism, offer a possible solution to this problem because they have a mathematical structure that enables the development of specific algorithms for global optimization. Results: Based on the GMA canonical representation, we have developed in previous works a highly efficient optimization algorithm and a set of related strategies for understanding the evolution of adaptive responses in cellular metabolism. Here, we explore the possibility of recasting kinetic non-linear models into an equivalent GMA model, so that global optimization on the recast GMA model can be performed. With this technique, optimization is greatly facilitated and the results are transposable to the original non-linear problem. This procedure is straightforward for a particular class of non-linear models known as Saturable and Cooperative (SC) models that extend the power-law formalism to deal with saturation and cooperativity. Conclusions: Our results show that recasting non-linear kinetic models into GMA models is indeed an appropriate strategy that helps overcoming some of the numerical difficulties that arise during the global optimization task.
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This work proposes the detection of red peaches in orchard images based on the definition of different linear color models in the RGB vector color space. The classification and segmentation of the pixels of the image is then performed by comparing the color distance from each pixel to the different previously defined linear color models. The methodology proposed has been tested with images obtained in a real orchard under natural light. The peach variety in the orchard was the paraguayo (Prunus persica var. platycarpa) peach with red skin. The segmentation results showed that the area of the red peaches in the images was detected with an average error of 11.6%; 19.7% in the case of bright illumination; 8.2% in the case of low illumination; 8.6% for occlusion up to 33%; 12.2% in the case of occlusion between 34 and 66%; and 23% for occlusion above 66%. Finally, a methodology was proposed to estimate the diameter of the fruits based on an ellipsoidal fitting. A first diameter was obtained by using all the contour pixels and a second diameter was obtained by rejecting some pixels of the contour. This approach enables a rough estimate of the fruit occlusion percentage range by comparing the two diameter estimates.
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Tele- ja dataviestinnän yhdistyminen digitaaliseen sisältöön luo uusia palveluideoita sekä mobiili- että internetverkkoihin. Nämä palvelut kehitetään usein erikseen, jolloin saman sisällön käyttäminen eri pääsymenetelmin ei ole mahdollista. Sisältömuunnos on mahdollista sisällön ja muotoilun eriyttämisellä, joka puolestaan vaatii informaatioyksiköiden merkkauksen sisältöä kuvaavilla lisätiedoilla. Tässä diplomityössä tutkitaan Extensible Markup Languagen (XML) käyttöä yhdistyneiden palvelujen sisältömuunnoksessa. Nykyisiä ja tulevia palveluita ja verkkoja tarkastellaan sekä sisällön että liiketoiminnan kannalta. Lisäksi esitellään lyhyesti omia ajatuksia ja käsityksiä yhdistyneistä palveluista ja informaation täsmällisyydestä. Työn käytännön osuudessa kuvataan itse suunniteltu palvelualusta sekä esitellään sen avulla rakennettuja sovelluksia