A statistical approach to sensitivity zone definition in remote sensing methods

Osnovni predmet istraživanja u disertaciji je analiza metodologije daljinskog uzorkovanja s aspekta prikupljanja i pripreme podataka u formu pogodnu za obradu, i posebno obrade podataka statističkim metodama u svrhu klasifikacije, sa ciljem identifikacije određenih pojava. Poseban akcenat istraživanja je predlaganje metodologije za definisanje zone osetljivosti pri klasifikaciji pojava, primarmo pomoću statističkih metoda multivarijacione analize. Daljinsko uzorkovanje se najčešće opisuje kao naučna oblast i tehnika za prikupljanje informacija o objektu (najčešće Zemljinoj površini) bez dolaženja u kontakt sa njim. Sprovodi se uzorkovanjem (očitavanjem) putem beleženja reflektovane ili emitovane energije (elektromagnetno zračenje, akustičnost, itd.) objekta, procesiranjem, analiziranjem i primenom informacija. Danas, daljinsko uzorkovanje je prepoznata interdisciplinarna oblast širom sveta. Često je uparena sa disciplinama obrade slika i geografskog informacionog sistema (GIS) za široku oblast geospatijalne nauke i tehnologije, te se u disertaciji čini osvrt na povezanost GIS-a i daljinskog uzorkovanja, gde je GIS nezaobilazan alat u analizi prostornih podataka. Svaka digitalna slika je sastavljena od piksela, koji čine najsitnije komponente jedne slike i koji imaju svoju osvetljenost i zabeležni spektar boja, a koje možemo smatrati pojedinačnim entitetima statističkog uzorka koji predstavlja sama slika. U disertaciji je od posebnog značaja klasifikacija daljinski uzorkovanih podataka i koristi se da identifikuje i klasifikuje delove ili piksele slike. Klasifikacija se izvodi na višestrukim skupovima podataka a cilj je dodeljivanje svakog piksela slike određenoj klasi na osnovu statističkih karakteristika intenziteta i obojenosti piksela. Termin multivarijaciona analiza se koristi da predstavi višedimenzionalni aspekt analize podataka. Mnogobrojne pojave i fenomeni opisani su većim brojem različitih promenljivih, a to se svakako odnosi i na podatke dobijene daljinskim uzorkovanjem gde je svako piksel tipično predstavljen u tri ili više različitih opsega svetlosnog spektra. Multivarijaciona analiza se opisuje kao skup statističkih metoda koje simultano analiziraju višedimenziona merenja dobijena za svaku jedinicu posmatranja iz skupa objekata koji ispitujemo. U disertaciji su naročito opisane tehnike Analize grupisanja, koja je od manjeg značaja za kasnije predloženi metod, i Diskriminacione analize, koja je u srži predloženog metoda. Posebno je opisana Bajesova teorija odlučivanja kao fundamentalan statistički pristup problemu klasifikacije. Pristup bazira na kvantifikaciji kompromisa između različitih odluka klasifikacije pomoću verovatnoće i cene ili napora koji se javljaju tokom odlučivanja. Bajesova teorija odlučivanja pretpostavlja da je problem odlučivanja postavljen u probabilističkom kontekstu. Diskriminaciona analiza se bavi problemom razdvajanja grupa i alokacijom opservacija u ranije definisane grupe. U disertaciji je od posebnog značaja cilj diskriminacione analize koji se naziva klasifikacija a koji se odnosi na utvrđivanje postupka za klasifikaciju opservacija na osnovu vrednosti nekoliko promenljivih u dve ili više razdvojenih, unapred definisanih grupa...The main topic of the research in this dissertation is the analysis of remote sensing methodology from the aspect of collecting and preparing data in a form suitable for processing, and in particular data processing by the means of statistical methods for the purpose of classification, to identify certain phenomena. A particular emphasis of the research is to propose a methodology for defining the sensitivity zone in the classification of phenomena, primarily using statistical methods of multivariate analysis. Remote sensing is typically described as a scientific field and technique for collecting information about an object (usually the Earth's surface) without being in direct contact with the object. It is carried out by sampling through recording reflected or emitted energy (electromagnetic radiation, acoustics, and others) of the object, processing, analysing, and applying the information. Today, remote sensing is recognized as an interdisciplinary field all over the world. It is often paired with image processing disciplines and a geographic information system (GIS) for a vast area of geospatial science and technology, hence, in this dissertation a link between GIS and remote sensing is described, where GIS is a necessary tool in spatial data analysis. Each digital image is composed of pixels, which are the smallest components of a single image and have their brightness and a color spectrum recorded, which we can consider as individual entities of a statistical sample representing the image. In this dissertation, the classification of remotely-sensed data is of particular importance and is used to identify and classify parts or the pixels of the image. The classification is performed on multiple data sets, and the goal is to assign each pixel of an image to a particular class based on the statistical characteristics of the intensity and color of the pixels. The term multivariate analysis is used to present a multidimensional aspect of data analysis. Numerous phenomena are described by many different variables, and this certainly applies to data obtained by remote sensing where each pixel is typically represented in three or more different light spectrum bandwidths. Multivariate analysis is described as a set of statistical methods that simultaneously analyze multidimensional measurements obtained for each observation unit from a set of objects that we are examining. This dissertation describes the Data clustering techniques, which are, though, of less importance to the proposed method, and the Discriminant Analysis, which is at the core of the proposed method. Bayesian decision theory is described as a fundamental statistical approach to the problem of classification. The approach is based on the quantification of the compromise between different classification decisions using the probability and cost or effort that arise during decision-making. Bayesian decision theory assumes that the decision-making problem is set in a probabilistic context. Discriminant analysis deals with the problem of group separation and the allocation of observations in previously defined groups. In this dissertation, it is of particular importance the objective of discriminant analysis called classification, which refers to the establishment of a procedure for classifying observations based on the value of several variables in two or more separated, predefined a group..

Алгоритм диагностики и лечения отравления грибами

Facultatea de Medicina “Victor Papilian”, Sibiu, România, Spitalul Militar de Urgenţă, Sibiu, România, Conferinţa Ştiinţifico-Practică „Medicina modernă, actualităţi şi perspective”, consacrată aniversării de 40 de ani ai Spitalului Clinic al Ministerului Sănătăţii, 27-28 mai, 2010, Chişinău, Republica MoldovaSince information about natural exposures is often insufficient and incorrect, a new syndromic classification of mushroom poisoning is recommended to guide clinicians in making earlier diagnoses – especially in cases where only advanced critical care, including liver transplantation, may be life saving. In 2005, Diaz proposed a classification system based on presentation timing and target organ systemic toxicity (14 major syndromes, 4 new syndromes). The diagnosis is based on clinical evaluation and urinary amatoxin evaluation. The treatment objectives are: to prevent absorption of the toxin from the gastrointestinal tract and to promote elimination from the systemic circulation (primary and secondary detoxification); regarding amatoxin poisoning, to lower the serum concentration of amanitin as soon as possible and thereby shorten the period of time that hepatocytes and renal tubular cells are exposed (extracorporeal detoxification and liver transplant).Отсутствие в настоящее время систематизированной информации об отравлении грибами вызвало необходимость разработки новой классификации для оказания помощи врачам в ранней диагностике. В 2005 году Диас предложил классификацию отравлений грибами на основе двух критериев: скорость проявления симптомов интоксикации и системная токсичность. Позитивная диагностика основывается на клинической оценке и определении мочевого аматоксина. Целью лечения является: предотвращение всасывания токсинов из желудочно-кишечного тракта, а также первичная и вторичная детоксикация системы кровообращения

Prediction of improvement in skin fibrosis in diffuse cutaneous systemic sclerosis: a EUSTAR analysis

OBJECTIVES Improvement of skin fibrosis is part of the natural course of diffuse cutaneous systemic sclerosis (dcSSc). Recognising those patients most likely to improve could help tailoring clinical management and cohort enrichment for clinical trials. In this study, we aimed to identify predictors for improvement of skin fibrosis in patients with dcSSc. METHODS We performed a longitudinal analysis of the European Scleroderma Trials And Research (EUSTAR) registry including patients with dcSSc, fulfilling American College of Rheumatology criteria, baseline modified Rodnan skin score (mRSS) ≥7 and follow-up mRSS at 12±2 months. The primary outcome was skin improvement (decrease in mRSS of >5 points and ≥25%) at 1 year follow-up. A respective increase in mRSS was considered progression. Candidate predictors for skin improvement were selected by expert opinion and logistic regression with bootstrap validation was applied. RESULTS From the 919 patients included, 218 (24%) improved and 95 (10%) progressed. Eleven candidate predictors for skin improvement were analysed. The final model identified high baseline mRSS and absence of tendon friction rubs as independent predictors of skin improvement. The baseline mRSS was the strongest predictor of skin improvement, independent of disease duration. An upper threshold between 18 and 25 performed best in enriching for progressors over regressors. CONCLUSIONS Patients with advanced skin fibrosis at baseline and absence of tendon friction rubs are more likely to regress in the next year than patients with milder skin fibrosis. These evidence-based data can be implemented in clinical trial design to minimise the inclusion of patients who would regress under standard of care

Factors associated with disease progression in early-diagnosed pulmonary arterial hypertension associated with systemic sclerosis: longitudinal data from the DETECT cohort

OBJECTIVE: Pulmonary arterial hypertension (PAH) is a severe complication of systemic sclerosis (SSc). In this longitudinal study, we aimed to identify factors associated with an unfavourable outcome in patients with SSc with early PAH (SSc-PAH) from the DETECT cohort. METHODS: Patients with SSc-PAH enrolled in DETECT were observed for up to 3 years. Associations between cross-sectional variables and disease progression (defined as the occurrence of any of the following events: WHO Functional Class worsening, combination therapy for PAH, hospitalisation or death) were analysed by univariable logistic regression. RESULTS: Of 57 patients with PAH (median observation time 12.6 months), 25 (43.9%) had disease progression. The following factors (OR (95% CI)) were associated with disease progression: male gender (4.1 (1.2 to 14.1)), high forced vital capacity % predicted/carbon monoxide lung diffusion capacity (DLCO)% predicted ratio (3.6 (1.2 to 10.7)), high Borg Dyspnoea Index (1.7 (1.1 to 2.6)) and low DLCO% predicted (non-linear relationship). CONCLUSION: More than 40% of early-diagnosed patients with SSc-PAH had disease progression during a short follow-up time, with male gender, functional capacity and pulmonary function tests at PAH diagnosis being associated with progression. This suggests that even mild PAH should be considered a high-risk complication of SSc

Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study

Objectives: Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2). Methods: In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation), with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task) being performed before and after exercise on each occasion. Results: In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99) or omnivores (p = 0.27); nor was there any effect when data from both groups were pooled (p = 0.19). Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27). In study 2, exercise improved cognitive function across all tests (P0.05) of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise. Conclusion: 28 d of beta-alanine supplementation at 6.4g d-1 appeared not to influence brain homocarnosine/ carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists

Development and validation of a patient-reported outcome measure for systemic sclerosis: the EULAR Systemic Sclerosis Impact of Disease (ScleroID) questionnaire

OBJECTIVES: Patient-reported outcome measures (PROMs) are important for clinical practice and research. Given the high unmet need, our aim was to develop a comprehensive PROM for systemic sclerosis (SSc), jointly with patient experts. METHODS: This European Alliance of Associations for Rheumatology (EULAR)-endorsed project involved 11 European SSc centres. Relevant health dimensions were chosen and prioritised by patients. The resulting Systemic Sclerosis Impact of Disease (ScleroID) questionnaire was subsequently weighted and validated by Outcome Measures in Rheumatology criteria in an observational cohort study, cross-sectionally and longitudinally. As comparators, SSc-Health Assessment Questionnaire (HAQ), EuroQol Five Dimensional (EQ-5D), Short Form-36 (SF-36) were included. RESULTS: Initially, 17 health dimensions were selected and prioritised. The top 10 health dimensions were selected for the ScleroID questionnaire. Importantly, Raynaud's phenomenon, impaired hand function, pain and fatigue had the highest patient-reported disease impact. The validation cohort study included 472 patients with a baseline visit, from which 109 had a test-retest reliability visit and 113 had a follow-up visit (85% female, 38% diffuse SSc, mean age 58 years, mean disease duration 9 years). The total ScleroID score showed strong Pearson correlation coefficients with comparators (SSc-HAQ, 0.73; Patient's global assessment, Visual Analogue Scale 0.77; HAQ-Disability Index, 0.62; SF-36 physical score, -0.62; each p<0.001). The internal consistency was strong: Cronbach's alpha was 0.87, similar to SSc-HAQ (0.88) and higher than EQ-5D (0.77). The ScleroID had excellent reliability and good sensitivity to change, superior to all comparators (intraclass correlation coefficient 0.84; standardised response mean 0.57). CONCLUSIONS: We have developed and validated the EULAR ScleroID, which is a novel, brief, disease-specific, patient-derived, disease impact PROM, suitable for research and clinical use in SSc

Prospective evaluation of the capillaroscopic skin ulcer risk index in systemic sclerosis patients in clinical practice: a longitudinal, multicentre study.

Nailfold capillaroscopy (NC) is an important tool for the diagnosis of systemic sclerosis (SSc). The capillaroscopic skin ulcer risk index (CSURI) was suggested to identify patients at risk of developing digital ulcers (DUs). This study aims to assess the reliability of the CSURI across assessors, the CSURI change during follow-up and the value of the CSURI in predicting new DUs. This multicentre, longitudinal study included SSc patients with a history of DUs. NC images of all eight fingers were obtained at baseline and follow-up and were separately analysed by two trained assessors. Sixty-one patients were included (median observation time 1.0 year). In about 40% of patients (assessor 1, n = 24, 39%; assessor 2, n = 26, 43%) no megacapillary was detected in any of the baseline or follow-up images; hence the CSURI could not be calculated. In those 34 patients in whom CSURI scores were available from both assessors (26% male; median age 57 years) the median baseline CSURI was 5.3 according to assessor 1 (IQR 2.6-16.3), increasing to 5.9 (IQR 1.3-12.0) at follow-up. According to assessor 2, the CSURI diminished from 6.4 (IQR 2.4-12.5) to 5.0 (IQR 1.7-10.0). The ability of a CSURI ≥ 2.96 category to predict new DUs was low (for both assessors, positive predictive value 38% and negative predictive value 50%) and the inter-assessor agreements for CSURI categories were fair to moderate. In this study, around 40% of patients could not be evaluated with the CSURI due to the absence of megacapillaries. Clinical decisions based on the CSURI should be made with caution. Current Controlled Trials, ISRCTN04371709 . Registered on 18 March 2011

Polymorphisms of glutathione-S-transferase M1, T1, P1 and the risk of prostate cancer: a case-control study

<p>Abstract</p> <p>Background</p> <p>It has been suggested that polymorphisms in glutathione-<it>S</it>-transferases (GST) could predispose to prostate cancer through a heritable deficiency in detoxification pathways for environmental carcinogens. Yet, studies linking <it>GST </it>polymorphism and prostate cancer have so far failed to unambiguously establish this relation in patients. A retrospective study on healthy, unrelated subjects was conducted in order to estimate the population <it>GST </it>genotype frequencies in the Slovak population of men and compare our results with already published data (GSEC project-Genetic Susceptibility to Environmental Carcinogens). A further aim of the study was to evaluate polymorphisms in <it>GST </it>also in patients with prostate cancer in order to compare the evaluated proportions with those found in the control subjects.</p> <p>Methods</p> <p>We determined the <it>GST </it>genotypes in 228 healthy, unrelated subjects who attended regular prostate cancer screening between May 2005 and June 2007 and in 129 histologically verified prostate cancer patients. Analysis for the <it>GST </it>gene polymorphisms was performed by PCR and PCR-RFLP.</p> <p>Results</p> <p>We found that the <it>GST </it>frequencies are not significantly different from those estimated in a European multicentre study or from the results published by another group in Slovakia. Our results suggest that <it>Val/Val </it>genotype of <it>GSTP1 </it>gene could modulate the risk of prostate cancer, even if this association did not reach statistical significance. We did not observe significantly different crude rates of the <it>GSTM1 </it>and <it>GSTT1 </it>null genotypes in the men diagnosed with prostate cancer and those in the control group.</p> <p>Conclusion</p> <p>Understanding the contribution of <it>GST </it>gene polymorphisms and their interactions with other relevant factors may improve screening diagnostic assays for prostate cancer. We therefore discuss issues of study feasibility, study design, and statistical power, which should be taken into account in planning further trials.</p