A Gradual Polymorphic Type System with Subtyping for Prolog

Although Prolog was designed and developed as an untyped language, there have been numerous attempts at proposing type systems suitable for it. The goal of research in this area has been to make Prolog programming easier and less error-prone not only for novice users, but for the experienced programmer as well. Despite the fact that many of the proposed systems have deep theoretical foundations that add types to Prolog, most Prolog vendors are still unwilling to include any of them in their compiler\u27s releases. Hence standard Prolog remains an untyped language. Our work can be understood as a step towards typed Prolog. We propose an extension to one of the most extensively studied type systems proposed for Prolog, the Mycroft-O\u27Keefe type system, and present an implementation in XSB-Prolog. The resulting type system can be characterized as a Gradual type system, where the user begins with a completely untyped version of his program, and incrementally obtains information about the possible types of the predicates he defines from the system itself, until type signatures are found for all the predicates in the source code

Application of chemometric methods for assessment and modelling of microbiological quality data concerning coastal bathing water in Greece

Background. Worldwide, the aim of managing water is to safeguard human health whilst maintaining sustainable aquatic and associated terrestrial, ecosystems. Because human enteric viruses are the most likely pathogens responsible for waterborne diseases from recreational water use, but detection methods are complex and costly for routine monitoring, it is of great interest to determine the quality of coastal bathing water with a minimum cost and maximum safety. Design and methods. This study handles the assessment and modelling of the microbiological quality data of 2149 seawater bathing areas in Greece over 10-year period (1997-2006) by chemometric methods. Results. Cluster analysis results indicated that the studied bathing beaches are classified in accordance with the seasonality in three groups. Factor analysis was applied to investigate possible determining factors in the groups resulted from the cluster analysis, and also two new parameters were created in each group; VF1 includes E. coli, faecal coliforms and total coliforms and VF2 includes faecal streptococci/enterococci. By applying the cluster analysis in each seasonal group, three new groups of coasts were generated, group A (ultraclean), group B (clean) and group C (contaminated). Conclusions. The above analysis is confirmed by the application of discriminant analysis, and proves that chemometric methods are useful tools for assessment and modeling microbiological quality data of coastal bathing water on a large scale, and thus could attribute to effective and economical monitoring of the quality of coastal bathing water in a country with a big number of bathing coasts, like Greece

Seroprevalence of IgG Antibodies against Echinococcus granulosus in the Population of the Region of Thessaly, Central Greece

Echinococcosis notification rate in Greece, based on the most recent data, is below 0.25 per 100,000 population. To further investigate the epidemiology of echinococcosis in Greece a study was designed to determine the seroprevalence of Echinococcus granulosus antibodies in the population of Thessaly, Central Greece. Five hundred and forty two left over blood samples in Thessaly laboratories, were collected using a stratified convenient sampling procedure. Samples were analyzed with enzyme linked immunosorbent assay. The seropositivity found was 1.1%(95% C.I., 0.5–2.5), with 5 out of 6 seropositive results to be in the age group of over 65 (OR = 17.95, 95%CI 2.04–157.11, p value 0.009). Rural residence was also found as a risk factor to seropositivity (RR = 7.60, 95% CI 0.89–64.64, p value 0.039). Surveillance data and our study results converge that echinococcosis is being reduced in Greece, with older population to be affected mostly. These might be due to the disease transmission restriction, by the control measures being implemented. Efforts should be continued, in both animals and humans side, by increasing training campaigns and public awareness

Regional differences in mortality in Greece (1984–2004): The case of Thrace

<p>Abstract</p> <p>Background</p> <p>Mortality differences at national level can generate hypothesis on possible causal association that could be further investigated. The aim of the present study was to identify regions with high mortality rates in Greece.</p> <p>Methods</p> <p>Age adjusted specific mortality rates by gender were calculated in each of the 10 regions of Greece during the period 1984–2004. Moreover standardized mortality rates (SMR) were also calculated by using population census data of years 1981, 1991, 2001. The mortality rates were examined in relation to GDP per capita, the ratio of hospital beds, and doctors per population for each region.</p> <p>Results</p> <p>During the study period, the region of Thrace recorded the highest mortality rate at almost all age groups in both sexes among the ten Greek regions. Thrace had one of the lowest GDP per capita (11 123 Euro) and recorded low ratios of Physicians (284) per 100 000 inhabitants in comparison to the national ratios. Moreover the ratio of hospital beds per population was in Thrace very low (268/100 000) in comparison to the national ratio (470/100 000). Thrace is the Greek region with the highest percentage of Muslim population (33%). Multivariate analysis revealed that GDP and doctors/100000 inhabitants were associated with increased mortality in Thrace.</p> <p>Conclusion</p> <p>Thrace is the region with the highest mortality rate in Greece. Further research is needed to assess the contribution of each possible risk factor to the increased mortality rate of Thrace which could have important public health implications.</p

Θεωρίες επιλογής εφαρμοστέου δικαίου και forum non conveniens στις ΗΠΑ

Η παρούσα διπλωματική ασχολείται με τις επιλογές εφαρμοστέου δικαίου και τον δικονομικό κανόνα forum non conveniens στις ΗΠΑ. Στο πρώτο μέρος γίνεται ανάπτυξη των θεωριών επιλογής εφαρμοστέου δικαίου στις Ηνωμένες Πολιτείες, με έμφαση στις θεωρίες εκείνες, οι οποίες μπορεί να παρουσιάζουν μεγαλύτερο σύνδεσμο με το δικονομικό κανόνα forum non conveniens, αναπτύσσεται. Στο δεύτερο μέρος αναπτύσσεται δικονομικός κανόνας forum non conveniens, εξετάζοντας μεταξύ άλλων και το σκοπό πίσω από το εν λόγω δόγμα, και οι προϋποθέσεις εφαρμογής του, οι οποίες εξετάζονται αναλυτικά στο παρόν έργο.The diploma thesis focuses on the considerations of choice of law and the forum non conveniens doctrine in the US. The first part analyzes the considerations of choice of law in the United States, with emphasis on those theories, which may have a greater connection to the forum non conveniens doctrine. The second part analyzes the forum non conveniens doctrine and examines the purpose behind this doctrine and the terms of its implementation, which are discussed in detail in this thesis

Management of environmental health issues for the 2004 Athens Olympic Games: is enhanced integrated environmental health surveillance needed in every day routine operation?

BACKGROUND: Management of environmental health issues is an integral part of public health systems. An active integrated environmental health surveillance and response system was developed for the Athens Olympics to monitor and prevent exposure to environmental hazards. The potential for permanent implementation of the program was examined. METHODS: The environmental health surveillance and response system included standardization, computerization and electronic transmission of data concerning environmental inspections of 17 site categories (restaurants, swimming pools etc) of public health interest, drinking and recreational water examinations and suggested corrective actions. The Olympic Planning Unit integrated and centrally managed data from 13 public health agencies, recommended, supervised and coordinated prompt corrective actions. Methods used to test the effectiveness of the program were the assessment of water quality test and inspection results trends over time using linear regression and epidemiological surveillance findings. RESULTS: Between January 2003 and September the 30th, 2004, 196 inspectors conducted 8562 inspections, collected 5024 water samples and recommended 17 027 corrective actions. In 10 cruise ships used as floating hotels inspectors conducted 10 full inspections, 2 re-inspections, and 27 follow-up inspections. Unsatisfactory inspection results (r = 0.44, p < 0.0001) and positive water quality tests (r = 0.39, p < 0.001) presented an overall decrease trend over time. In August, 2003, an outbreak of salmonellosis was linked to a hotel restaurant which accommodated athletes during a test event. CONCLUSION: Lessons learned for future events include timely implementation and installation of communication processes, and rapid and coordinated response to unsatisfactory inspection results. Routine national programs need to adopt enhanced environmental health surveillance aimed at public health decision-making, but with a different perspective

Health Promotion Programs Related to the Athens 2004 Olympic and Para Olympic Games

Background: The Olympic Games constitute a first-class opportunity to promote athleticism and health messages. Little is known, however on the impact of Olympic Games on the development of health-promotion programs for the general population. Our objective was to identify and describe the population-based health-promotion programs implemented in relation to the Athens 2004 Olympic and Para Olympic Games. Methods: A cross-sectional survey of all stakeholders of the Games, including the Athens 2004 Organizing Committee, all ministries of the Greek government, the National School of Public Health, all municipalities hosting Olympic events and all official private sponsors of the Games, was conducted after the conclusion of the Games. Results: A total of 44 agencies were surveyed, 40 responded (91%), and ten (10) health-promotion programs were identified. Two programs were implemented by the Athens 2004 Organizing Committee, 2 from the Greek ministries, 2 from the National School of Public Health, 1 from municipalities, and 3 from official private sponsors of the Games. The total cost of the programs was estimated at 943,000 Euros; a relatively small fraction (0.08%) of the overall cost of the Games. Conclusion: Greece has made a small, however, significant step forward, on health promotion, in the context of the Olympic Games. The International Olympic Committee and the future hosting countries, including China, are encouraged to elaborate on this idea and offer the world a promising future for public health

Factors associated with adolescent cigarette smoking in Greece: Results from a cross sectional study (GYTS Study)

<p>Abstract</p> <p>Background</p> <p>Data about the predictors of smoking among adolescents in Greece are sparse. We tried to identify factors associated with current cigarette smoking among in-school adolescents in Greece in the context of GYTS study.</p> <p>Methods</p> <p>A secondary analysis of data from a questionnaire study using the Global Youth Tobacco Survey methodology was conducted to identify factors associated with smoking among adolescents in Greece. Data were collected in 2004–2005. The outcome variable was cigarette smoking within the past 30 days preceding the survey while independent variables included age, gender, parental educational status, parental smoking, perception of harmfulness of smoking, and the amount of pocket money at the adolescent's disposal.</p> <p>Results</p> <p>6141 adolescents (51.5% males and 48.5% females) participated in the study. In multivariate analysis, cigarette smoking was associated with male gender (OR: 1.62; 95% CI: 1, 08–3.08), parental smoking (OR: 2.59; 95% CI: 1.45–5.89), and having pocket money ≥ 16 Euros (OR: 2.64; 95% CI: 1.19–5.98).</p> <p>Conclusion</p> <p>Male gender, parental smoking, and having pocket-money ≥ 16 Euros were independently associated with current smoking among Greek students. These findings could be taken into account in order to formulate a comprehensive anti-smoking strategy in Greece.</p