Ensemble classification of incomplete data – a non-imputation approach with an application in ovarian tumour diagnosis support

Wydział Matematyki i InformatykiW niniejszej pracy doktorskiej zająłem się problemem klasyfikacji danych niekompletnych. Motywacja do podjęcia badań ma swoje źródło w medycynie, gdzie bardzo często występuje zjawisko braku danych. Najpopularniejszą metodą radzenia sobie z tym problemem jest imputacja danych, będąca uzupełnieniem brakujących wartości na podstawie statystycznych zależności między cechami. W moich badaniach przyjąłem inną strategię rozwiązania tego problemu. Wykorzystując opracowane wcześniej klasyfikatory można przekształcić je do formy, która zwraca przedział możliwych predykcji. Następnie, poprzez zastosowanie operatorów agregacji oraz metod progowania, można dokonać finalnej klasyfikacji. W niniejszej pracy pokazuję jak dokonać ww. przekształcenia klasyfikatorów oraz jak wykorzystać strategie agregacji danych przedziałowych do klasyfikacji. Opracowane przeze mnie metody podnoszą jakość klasyfikacji danych niekompletnych w problemie wspomagania diagnostyki guzów jajnika. Dodatkowa analiza wyników na zewnętrznych zbiorach danych z repozytorium uczenia maszynowego Uniwersytetu Kalifornijskiego w Irvine (UCI) wskazuje, że przedstawione metody są komplementarne z imputacją.In this doctoral dissertation I focus on the problem of classification of incomplete data. The motivation for the research comes from medicine, where missing data phenomena are commonly encountered. The most popular method of dealing with data missingness is imputation; that is, inserting missing data on the basis of statistical relationships among features. In my research I choose a different strategy for dealing with this issue. Classifiers of a type previously developed can be transformed to a form which returns an interval of possible predictions. In the next step, with the use of aggregation operators and thresholding methods, one can make a final classification. I show how to make such transformations of classifiers and how to use aggregation strategies for interval data classification. These methods improve the quality of the process of classification of incomplete data in the problem of ovarian tumour diagnosis. Additional analysis carried out on external datasets from the University of California, Irvine (UCI) Machine Learning Repository shows that the aforementioned methods are complementary to imputation

Simulations of Colorado Potato Beetle Development in Poland Based on Four Climate Change Scenarios

The simulations were conducted using actual data and virtual data. The actual data were recorded in the period of 1986–2005 at 16 localities representing 16 regions of Poland. The virtual data were obtained after transformation of the recorded data to reflect a temperature changes under RCP2.6, RCP4.5, RCP6.0 and RCP8.5 scenarios according to giss_e2_r climate model. The model used in the study was based on scientific reports describing the influence of temperature on acceleration of the onset of egg laying and on successive stages of Colorado potato beetle as well as publications on the effects of photoperiod on the pest diapause. The study showed a growing threat to potato from Colorado potato beetles as a result of the temperature rise. The fastest development of the pest appeared in simulations under RCP8.5 scenario. Of 16 regions surveyed in the study, the south-western part of Poland was found to be most threatened by Colorado potato beetle as a result of anticipated climate change

Use of negative ion mass spectrometry for simultaneous determination of sulfur isotope ratios δ33S and δ34S

We describe a newly constructed dual inlet system and triple collector for precision study of sulfur isotope anomalies, Δ33S, using negative ion mass spectrometry. SO2 gas is admitted to the ion source where it is ionized ether to SO- or S- by low energy electrons (resonant ionization) and the ion beam is analyzed by a single focusing magnetic analyzer. Another gas which can be used for  δ33S and δ34S analysis by negative ion mass spectrometry  is SF6 on mass spectrum of SF5- ions

Automated Meter Reading For Water Demand Forecast And Hydraulic Modelling Of The Municipal Water Distribution System In Mikołów, Poland

This paper presents preliminary results of a project aimed at utilising automated meter reading (AMR) system for water demand forecasting and hydraulic modelling of Mikołów (Poland) water distribution system. This system will allow for near-real time collection of hydraulic data. Accurate estimation and prediction of the demand patterns of the customers is a crucial element affecting accuracy of hydraulic model. AMR will be used to analyse the behaviour of individual household-based water consumption. Calibration and validation of the model will be realised by combining existing SCADA system and mobile (temporary) measurement points. Total length of the main water distribution system in Mikołów (pop. 40 000) is about 310 km, with 117 km of service pipelines. Water in amount of 300 000 m3 per month is supplied to over 7600 individual clients and bulk (industrial) customers. All connections to water network will be equipped with automated meter and incorporated into existing monitoring system. The existing telemetry system for Mikołów is composed of 30 stations measuring flow rate and pressure in the water distribution network (WDN). A hybrid AMR system will be used. It combines local reading of meters by two-way RF units with telemetry stations sending signals using mobile network (GSM) to the main database server. This server contains a database of water consumption readings for individual customers. To take advantage of the AMR system a detailed hydraulic model of the Mikołów WDN was build. The hydraulic model will be later coupled with an integrated ICT system for comprehensive management of the water distribution network. The seamless connection between model and GIS, CIS and SCADA modules will allow for the network topology update, automatic re-calibration, water demand reading and forecasting

Hydraulic Modelling And Calibration Of The Upper Silesian Waterworks In Poland

Our paper presents the preliminary results of hydraulic modelling and calibration of a complex water transfer and distribution system of Upper Silesian Waterworks PLC (USW). A new approach to quasi real-time model calibration and validation in connection with an integrated ICT system will be presented. The USW is the biggest water company in Poland and one of the biggest in Europe delivering water to over 3 million customers in Silesian Metropolis, on the area covering about 4.3 thousand square kilometres, with the main water network which is over 880 km long. This water distribution system incorporates central and western sub-regions of Silesia (Silesian Metropolis) supplying water in the amount of about 400 000 m3/d. The USW water transportation system is a mix of pressure and gravity mains (with diameters ranging between 300 mm and 1800 mm) conveying the water to several local (municipal) distribution systems and bulk buyers (industrial). The area is characterised by a great diversity of terrain altitude, heavy concentration of industry and severe mining damages. This dynamic environment requires constant update of WDN topology and real-time water demand from wholesale customers (towns and cities, coal mines, steel, energy, automotive, machinery and chemical industry). For calibration and validation of hydraulic model we used the extensive telemetry system composed of 180 monitoring stations (including wholesale customers meters, reservoirs, tanks, pumping stations etc.). This system contains over 800 sensors measuring flow rate, pressure, turbidity and chlorine residual. The existing database of measurements will be temporarily supported by mobile measurement points used for identification of hydraulic properties of selected groups of pipelines. Hydraulic model (based on EPANET) is an element of the integrated ICT system for comprehensive water network management, consisting of several modules: GIS, CIS, SCADA as well as tools for multi-criteria optimisation and forecasting

Physiological aspects of sex differences and Haldane’s rule in Rumex hastatulus

Haldane’s rule (HR, impairment of fertility and/or viability of interracial hybrids) seems to be one of few generalizations in evolutionary biology. The validity of HR has been confirmed in animals, and more recently in some dioecious plants (Silene and Rumex). Dioecious Rumex hastatulus has two races differing in the sex chromosome system: Texas (T) and North Carolina (NC), and T × NC males showed both reduced pollen fertility and rarity—two classical symptoms of Haldane’s rule (HR). The reduced fertility of these plants has a simple mechanistic explanation, but the reason for their rarity was not elucidated. Here, we measured selected physiological parameters related to the antioxidant defense system in parental races and reciprocal hybrids of R. hastatulus. We showed that the X-autosome configurations, as well as asymmetries associated with Y chromosomes and cytoplasm, could modulate this system in hybrids. The levels and quantitative patterns of the measured parameters distinguish the T × NC hybrid from the other analyzed forms. Our observations suggest that the rarity of T × NC males is caused postzygotically and most likely related to the higher level of oxidative stress induced by the chromosomal incompatibilities. It is the first report on the physiological aspects of HR in plants

Trigone ventricular meningiomas — clinical characteristics, histopathology and results of surgical treatment

Aim of the study. Intraventricular meningiomas (IVMs) are rare tumours accounting for 0.5–3.0% of all meningiomas. IVMs require different surgical approaches and preparation in deep brain areas. The aim of our study was to present the clinico- -histopathological characteristics and treatment outcomes of trigone IVMs in a series of 15 patients. Materials and methods. Eight women and seven men (mean age 52) with 15 trigone IVMs were retrospectively analysed. Patients presented with headache (47%), psychoorganic syndrome (40%), hemianopsia (33%) or paresis (20%), including three (20%) patients with Karnofsky Performance Scale (KPS) < 80. Mean tumour size was 55.2 mm (range: 30–100 mm). Results. Gross total tumour resection was performed in 14 (93%) cases, and subtotal in one (7%). A new deficit appeared in 83% (5/6) following a transparietal approach, in 14% (1/7) following a transtemporal approach, and in none of two patients following a transoccipital approach. Postoperative complications occurred in six (40%) patients; no patient died, but in two (13%) the new deficit was permanent. Tumour re-growth was found in two (13%) patients after 14 and 31 months. Meningiomas of WHO grade I occurred in 12, grade II in three, and grade III in one tumour recurrence. In long-term follow-up (mean: 60.8 months), including the results of revision operations, KPS: 80–100 was in 13 (87%) patients, KPS: 50 in one (severe hemiparesis after revision) and one patient was lost to follow-up (KPS: 100 on discharge). Conclusions. 20% of IVMs in our series were atypical. The results of surgery for IVMs, although satisfactory in general, require further improvement by reducing the rate of focal deficits resulting from a surgical approach

Effect of the spray volume adjustment model on the efficiency of fungicides and residues in processing tomato

This study compared the effects of a proportionate spray volume (PSV) adjustment model and a fixed model (300 L/ha) on the infestation of processing tomato with potato late blight (Phytophthora infestans (Mont.) de Bary) (PLB) and azoxystrobin and chlorothalonil residues in fruits in three consecutive seasons. The fungicides were applied in alternating system with or without two spreader adjuvants. The proportionate spray volume adjustment model was based on the number of leaves on plants and spray volume index. The modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was optimized and validated for extraction of azoxystrobin and chlorothalonil residue. Gas chromatography with a nitrogen and phosphorus detector and an electron capture detector were used for the analysis of fungicides. The results showed that higher fungicidal residues were connected with lower infestation of tomato with PLB. PSV adjustment model resulted in lower infestation of tomato than the fixed model (300 L/ha) when fungicides were applied at half the dose without adjuvants. Higher expected spray interception into the tomato canopy with the PSV system was recognized as the reasons of better control of PLB. The spreader adjuvants did not have positive effect on the biological efficacy of spray volume application systems. The results suggest that PSV adjustment model can be used to determine the spray volume for fungicide application for processing tomato crop

Surgical treatment for spinal dural arteriovenous fistulas: Outcome, complications and prognostic factors

Background and purpose Spinal dural arteriovenous fistulas (SDAVFs) are rare, acquired pathology and they inevitably lead to severe disability if untreated. The aim of this study is to present the outcome and complications, and to find factors that may affect the outcome after surgical treatment. Methods Seventeen consecutive patients (men – 14, women – 3, age: 41–79) were retrospectively analyzed. The patients presented with paraparesis (88%), bladder symptoms (71%) and/or sensory disturbances (65%). The fistula was found in the upper thoracic spine in 2 cases, in the lower thoracic (T7–Th12) in 11 cases, and in the lumbar spine in 4 cases. Microsurgical shunt interruption was performed in all, followed by epidural arteries coagulation in 12 cases. Results In the long term, improvement or achievement of a good stable condition was observed in 13 patients (76%), and no patient deteriorated. All 5 paraplegic patients improved by at least 1 grade in MCS. Satisfactory results (modified McCormick Scale grades I–II) were found in 10 patients (59%), and 15(88%) were independent. Postoperative complications occurred in 4 patients (24%), two of them (12%) required revision surgery for epidural hematoma. The success rate was 94%; one patient required revision surgery for recurrent SDAVF. Better neurological condition on admission (p=0.0098) and age >60 years (p=0.0498) were the factors associated with satisfactory outcome. Conclusions Microsurgical closing of a SDAVF brings good and stable results over time. Aggressive treatment should be attempted even in cases of total loss of spinal cord function. Neurological condition before surgery and age may influence the outcome