844 research outputs found
Application of neural networks in the classification of medical images textures
Neural networks have been widely used in medical diagnostic processes. Imaging results obtained from medical devices can be analyzed in many ways. One of them is to analyze the texture of the received images. Examination of the textures of diagnostic images is based on the determination of specific parameters and characteristics of examined tissue or organ. The main goal is to assign the analyzed area to one of two basic groups: as a healthy tissue or a tissue with pathological changes. By using supervised classification and setting up a training base, it is possible to achieve 93% accuracy in classification results.Нейронні мережі широко застосовуються в медичних діагностичних процесах. Результати обробки зображень, отримані з медичних приладів, можна аналізувати багатьма способами. Один з них - це аналіз текстури отриманих зображень. Вивчення текстур діагностичних зображень ґрунтується на визначенні конкретних параметрів та характеристик досліджуваної тканини або органу. Основна мета полягає в тому, щоб класифікувати аналізовану ділянку як одну з двох основних груп: як здорову тканину або тканину з патологічними змінами. Використовуючи контрольовану класифікацію та налаштовану навчальну базу, можна досягти точності результатів класифікації 93%
The impact of type 1 diabetes on the development of the craniofacial mineralised tissues (bones and teeth): literature review
Background: There are many reports on the impact of diabetes on periodontium as well as the state of organs in diabetics; however, there is little research on the impact of the disease on morphological and anatomical changes in the mineralised tissues like teeth and craniofacial bones. The aim of this study was to present a review of literature on morphological and anatomical changes of mineralised tissues in the course of type 1 diabetes.
Materials and methods: A review of PubMed database was made using the keywords: morphological changes, anatomical changes, enamel hypoplasia, type 1 diabetes, induced diabetes and the names of individual anatomical and morphological structures of the teeth.
Results: The analysis of experimental studies have shown that in induced type 1 diabetes in rats there is a substantial reduction in the thickness of the enamel and dentin, compared with the control group. The changes in the content of individual minerals in the tissues of the tooth have been shown — a decrease in the concentration of calcium and fluoride ions and an increase in the concentration of magnesium. In a study conducted on embryos of rats born of diabetic dams, defects were observed in enamel organ, which can cause delayed enamel hypoplasia. Literature analysis revealed morphological disorders also in some clinical cases of patients with type 1 diabetes.
Conclusions: Type 1 diabetes mellitus as a metabolic disorder may affect changes in the structure of mineralised tissues, thereby increasing their susceptibility to caries development and orthognathic disorders
Air temperature changes in Toruń (central Poland) from 1871 to 2010
The article presents a detailed analysis of changes in air temperature in Toruń in the period 1871–2010 on the basis of homogenised monthly, seasonal and annual air temperature series which have been newly constructed (i.e. extended by the 50 years of 1871–1920). Over the 140-year study period, a sizeable and statistically significant increase of 0.1 °C per decade was found in the air temperature in Toruń. The greatest increases occurred for spring and winter, at 0.12 and 0.11 °C, respectively. A lesser warming, meanwhile, was recorded for autumn (0.10 °C/10 years), and particularly for summer (0.07 °C/10 years). The air temperature trends are statistically significant for all seasons. Air temperature differences between the monthly averages of three analysed subperiods (1871–1900, 1901–1950 and 1951–2010) and averages for the entire period under review rarely exceeded ± 0.5 °C. In all of these periods, the highest average air temperatures occurred in July and the lowest in January. The period of 1981–2010 had the highest frequency of occurrence of very and extremely warm seasons and years. Meanwhile, the highest frequency of very and extremely cool seasons and years was recorded in the 1940s and in the nineteenth century. In the period of 1871–2010, winters shortened markedly (by 7%) and summers lengthened by 3.8%. All of the presented aspects of air temperature in Toruń, which is representative of the climate of central Poland, are in close agreement with the findings of analogous studies of the same for other areas of Poland and Central Europe
Generalized Quantum Walk in Momentum Space
We consider a new model of quantum walk on a one-dimensional momentum space
that includes both discrete jumps and continuous drift. Its time evolution has
two stages; a Markov diffusion followed by localized dynamics. As in the well
known quantum kicked rotor, this model can be mapped into a localized
one-dimensional Anderson model. For exceptional (rational) values of its scale
parameter, the system exhibits resonant behavior and reduce to the usual
discrete time quantum walk on the line.Comment: 11 pages, 5 figure
The Nylon Scintillator Containment Vessels for the Borexino Solar Neutrino Experiment
Borexino is a solar neutrino experiment designed to observe the 0.86 MeV Be-7
neutrinos emitted in the pp cycle of the sun. Neutrinos will be detected by
their elastic scattering on electrons in 100 tons of liquid scintillator. The
neutrino event rate in the scintillator is expected to be low (~0.35 events per
day per ton), and the signals will be at energies below 1.5 MeV, where
background from natural radioactivity is prominent. Scintillation light
produced by the recoil electrons is observed by an array of 2240
photomultiplier tubes. Because of the intrinsic radioactive contaminants in
these PMTs, the liquid scintillator is shielded from them by a thick barrier of
buffer fluid. A spherical vessel made of thin nylon film contains the
scintillator, separating it from the surrounding buffer. The buffer region
itself is divided into two concentric shells by a second nylon vessel in order
to prevent inward diffusion of radon atoms. The radioactive background
requirements for Borexino are challenging to meet, especially for the
scintillator and these nylon vessels. Besides meeting requirements for low
radioactivity, the nylon vessels must also satisfy requirements for mechanical,
optical, and chemical properties. The present paper describes the research and
development, construction, and installation of the nylon vessels for the
Borexino experiment
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