Temporal analysis of political instability through descriptive subgroup discovery

This paper analyzes the Political Instability Task Force (PITF) data set using a new methodology based on machine learning tools for subgroup discovery. While the PITF used static data, this study employs both static and dynamic descriptors covering the 5-year period before onset. The methodology provides several descriptive models of countries especially prone to political instability. For the most part, these models corroborate the PITF’s findings and support earlier theoretical works. The paper also shows the value of subgroup discovery as a tool for developing a unified concept of political instability as well as for similar research designs

Expert-Guided Subgroup Discovery: Methodology and Application

This paper presents an approach to expert-guided subgroup discovery. The main step of the subgroup discovery process, the induction of subgroup descriptions, is performed by a heuristic beam search algorithm, using a novel parametrized definition of rule quality which is analyzed in detail. The other important steps of the proposed subgroup discovery process are the detection of statistically significant properties of selected subgroups and subgroup visualization: statistically significant properties are used to enrich the descriptions of induced subgroups, while the visualization shows subgroup properties in the form of distributions of the numbers of examples in the subgroups. The approach is illustrated by the results obtained for a medical problem of early detection of patient risk groups

Autonomna kontrola srčane frekvencije kod akutne ozljede vratne kralježnice

Spinal cord injury may cause loss of cardiovascular reflexes mediated by sympathetic drive due to interruption in the supraspinal control of spinal sympathetic motoneurons. The aim of this study was to analyze sympathovagal balance after acute spinal cord injury demonstrated by linear measures in time and frequency domain of heart rate variability (HRV ). The study included 40 tatraplegic patients after acute spinal cord injury and 40 healthy subjects as controls. Cardiac autonomic balance was evaluated by HRV analysis in time and frequency domain. The ratio of low to high frequencies (LF /HF ) was statistically significantly (Mann-Whitney U=0.0; Z=-7.7; P<0.001) different between the group with cervical spine injuries 0.41 (0158) and control group 1.71 (1875). LH /HF was significantly reduced in the group of patients with acute trauma. This study established HRV analysis by linear methods as an objective measure of normal and abnormal function of the autonomic nervous system. In conclusion, spinal cord injury causes dysfunction of the autonomic cardiovascular regulation and leads to disturbances of the modulatory sympathetic activity on the cardiovascular system. The HRV parameters analyzed indicate decreased but still present sympathetic activity and suggest that descending and ascending fibers of the sympathetic nervous system in isolated segment are undamaged, although without supraspinal control after acute spinal cord injury.Ozljedom vratne kralježnice može doći do gubitka simpatički posredovanih kardiovaskularnih refleksa zbog prekida supraspinalne kontrole spinalnih simpatičkih motoneurona. Cilj rada bio je analiza simpatovagalne ravnoteže nakon akutne ozljede vratne kralježnice prikazom rezultata varijabilnosti srčanog ritma (VSR) linearnim metodama u vremenskoj i frekvencijskoj domeni. Istraživanje je provedeno na 40 ispitanika s akutnom ozljedom vratne kralježnice i kralježnične moždine i s posljedičnim neurološkim deficitom tipa tetraplegije te na 40 zdravih ispitanika kontrolne skupine. Analizom parametara varijabilnosti srčanog ritma u vremenskoj i frekvencijskoj domeni praćena je autonomna kontrola srca. Omjer niskih i visokih frekvencija (LF /HF ) bio je statistički značajno (Mann-Whitney U=0,0; Z=-7,7; P<0,001) različit između skupine s ozljedom vratne kralježnice 0,41 (0,158) i kontrolne skupine 1,71 (1,875). Ispitivanje parametara VSR ukazuje na značajno snižen LF /HF nakon akutne ozljede kralježnice. Provedeno istraživanje potvrđuje ispitivanje varijabilnosti srčanog ritma linearnim metodama kao objektivnog pokazatelja normalne i poremećene funkcije autonomnog živčanog sustava. U zaključku, akutnom ozljedom vratne kralježnice dolazi do poremećaja autonomne kardiovaskularne regulacije i poremećaja modulacijske aktivnosti n. simpatikusa na kardiovaskularni sustav. Analiza parametara VSR pokazuju sniženu, ali prisutnu funkciju n. simpatikusa predmnijevajući da su aferentne i eferentne sveze simpatičkog autonomnog sustava u izoliranom segmentu ostale funkcijski neoštećene, iako bez kontrole viših centara kod akutne traume vratne kralježnice

Heart failure ontology

Abstract Ontology represents explicit specification of knowledge in a specific domain of interest in the form of concepts and relations among them. This paper presents a medical ontology describing the domain of heart failure (HF). Construction of ontology for a domain like HF is recognized as an important step in systematization of existing medical knowledge. The main virtue of ontology is that the represented knowledge is both computer and humanreadable. The current development of the HF ontology is one of the main results of the EU Heartfaid project. The ontology has been implemented using Ontology Web Language and Protégé editing tool. It consists of roughly 200 classes, 100 relations and 2000 instances. The ontology is a precise, voluminous, portable, and upgradable representation of the HF domain. It is also a useful framework for building knowledge based systems in the HF domain, as well as for unambiguous communication between professionals. In the process of developing the HF ontology there have been significant technical and medical dilemmas. The current result should not be treated as the ultimate solution but as a starting point that will stimulate further research and development activities that can be very relevant for both intelligent computer systems and precise communication of medical knowledge

Clusters of male and female Alzheimer's disease patients in the Alzheimer's Disease Neuroimaging Initiative (ADNI) database

This paper presents homogeneous clusters of patients, identified in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) data population of 317 females and 342 males, described by a total of 243 biological and clinical descriptors. Clustering was performed with a novel methodology, which supports identification of patient subpopulations that are homogeneous regarding both clinical and biological descriptors. Properties of the constructed clusters clearly demonstrate the differences between female and male Alzheimer’s disease patient groups. The major difference is the existence of two male subpopulations with unexpected values of intracerebral and whole brain volumes

Good Governance Problems and Recent Financial Crises in Some EU Countries

The starting point for the research has been the list of 147 banking crises within the period 1976– 2011 prepared by the International Monetary Fund. The countries with crises have been analysed with respect to publicly available World Bank indicators in the periods of three years before the crises. The machine learning methodology for subgroup discovery has been used for the analysis. It enabled identification of five subsets of crises. Two of them have been identified as especially useful for the characterization of EU countries with banking crises in the year 2008. Fast growing credit activity is characteristic for the first subgroup while socioeconomic problems recognized by non-increasing quality of public health are decisive for the second subgroup. Comparative analysis of EU countries included into these subgroups demonstrated statistically significant differences with respect to World Bank good governance indicator values for the period before the crisis. Control of corruption, rule of law, and government effectiveness are the indicators which are statistically different for these sets of countries. The significance of the result is in the segmentation of the corpus of countries with banking crises and the recognition of connections between banking crises, socioeconomic problems, and governance effectiveness in some EU countries

Discovery of relevant response in infected potato plants from time series of gene expression data

The paper presents a methodology for analyzing time series of gene expression data collected from the leaves of potato virus Y (PVY) infected and non-infected potato plants, with the aim to identify significant differences between the two sets of potato plants’ characteristic for various time points. We aim at identifying differentially- expressed genes whose expression values are statistically significantly different in the set of PVY infected potato plants compared to non- infected plants, and which demonstrate also statistically significant changes of expression values of genes of PVY infected potato plants in time. The novelty of the approach includes stratified data randomization used in estimating the statistical properties of gene expression of the samples in the control set of non-infected potato plants. A novel estimate that computes the relative minimal distance between the samples has been defined that enables reliable identification of the differences between the target and control datasets when these sets are small. The relevance of the outcomes is demonstrated by visualizing the relative minimal distance of gene expression changes in time for three different types of potato leaves for the genes that have been identified as relevant by the proposed methodology

Dairy workers education in Croatia

Promjene u našem odgojno-obrazovnom sistemu, uvođenjem usmjerenog obrazovanja uz rad, obuhvatile su i školske centre za obrazovanje mljekarskih radnika. Obrazovanje za zanimanje "mljekar" obavlja se u SR Hrvatskoj u 7 školskih centara (1979/80.) s ukupno 240 polaznika. Pored toga obrazuje se određen broj učenika za zanimanje "stručni radnik za operativno vođenje automatiziranih procesa", koji će raditi u mljekarskoj industriji