Towards a graph-based model of computer games

This paper proposes a new holistic approach to a formal model of computer games. The story and structure of a computer game is represented by a hierarchical layered graph, meanwhile the way that the game is played – by graph transformations. This approach enables comparative description of different games, analysis of dependencies between a game structure and players’ strategies, automatic gameplay generation, and switching from single- to multi­player mode

Mean glandular dose values used for the mammography screening program in Poland according to the type of image registration system

Between 2007–2014, there have been considerable changes in the use of different types of detector systems at mammography facilities undertaking screening programs in Poland. The use of screen-film systems (termed SF systems) has largely decreased and been replaced by either computed radiography (termed CR systems) or digital radiography systems (termed DR systems); this inevitably affecting mean glandular dose values. The study aim was to evaluate changes of mean glandular dose values for a dose exposure of 4.5 cm (MGD4,5cmPMMA) achieved by using different image detectors. The study consisted of analysing 1499 protocols for quality control tests carried out by medical physicists at 16 Regional Coordination Offices in 2007, 2011, 2012 and 2013. The mean CR system values were higher than for SF systems; by 25% in 2011, by 26% in 2012, and by 28% in 2013. In subsequent years, the MGD4,5cmPMMA mean values for DR systems were higher than for SF systems by respectively 15%, 4% and 5%. Also in the subsequent years, the MGD4,5cmPMMA mean values for CR systems were higher than for DR systems by respectively 13%, 23% and 24%. In all cases, the MGD4,5cmPMMA mean values were within the acceptable level of 2.5 mGy. The MGD4,5cmPMMA mean values were different, depending on the detection system used for mammography screening in Poland

Expression of the membrane complement regulatory proteins (CD55 and CD59) in human thymus.

CD59 is one of the key molecules involved in cell protection against autologus complement. The fact that complement regulatory proteins are able to prevent hyperacute rejection of organs in pig to primate model, raises the question of possible complement regulatory protein (CRP) involvement in the maturation of immunological system. We report here that in foetal and postnatal human thymus, CD59 and CD55 are primarily located on Hassall's corpuscles and medullary epithelial cells. This localization highly correlates with the expression of CD30L, which is the member of the tumour necrosis factor superfamily. Additionally, TUNEL technique was used to visualize distribution of apoptotic cells in the thymus, which revealed the presence of apoptotic cells closely associated with the Hassall's corpuscles. The observed co-localization of CD59, CD55 and CD30L might suggest an involvement of the complement system in thymic selection in humans

Quantifying origin and character of long-range correlations in narrative texts

In natural language using short sentences is considered efficient for communication. However, a text composed exclusively of such sentences looks technical and reads boring. A text composed of long ones, on the other hand, demands significantly more effort for comprehension. Studying characteristics of the sentence length variability (SLV) in a large corpus of world-famous literary texts shows that an appealing and aesthetic optimum appears somewhere in between and involves selfsimilar, cascade-like alternation of various lengths sentences. A related quantitative observation is that the power spectra S(f) of thus characterized SLV universally develop a convincing `1/f^beta' scaling with the average exponent beta =~ 1/2, close to what has been identified before in musical compositions or in the brain waves. An overwhelming majority of the studied texts simply obeys such fractal attributes but especially spectacular in this respect are hypertext-like, "stream of consciousness" novels. In addition, they appear to develop structures characteristic of irreducibly interwoven sets of fractals called multifractals. Scaling of S(f) in the present context implies existence of the long-range correlations in texts and appearance of multifractality indicates that they carry even a nonlinear component. A distinct role of the full stops in inducing the long-range correlations in texts is evidenced by the fact that the above quantitative characteristics on the long-range correlations manifest themselves in variation of the full stops recurrence times along texts, thus in SLV, but to a much lesser degree in the recurrence times of the most frequent words. In this latter case the nonlinear correlations, thus multifractality, disappear even completely for all the texts considered. Treated as one extra word, the full stops at the same time appear to obey the Zipfian rank-frequency distribution, however.Comment: 28 pages, 8 figures, accepted for publication in Information Science

Trendy zmian wartości dawek promieniowania X w mammograficznych badaniach skriningowych w Polsce vs zmiany używanych rejestratorów obrazu

Na przestrzeni lat 2007–2014 znacznie zmieniły się rodzaje rejestratora obrazu w placówkach mammograficznych realizujących program badań przesiewowych w Polsce. Odsetek systemów z detektorem filmowym (zwanych dalej systemami SF — screen-film systems) zmniejszył się w znacznym stopniu. Zostały one zastąpione przez systemy z płytami obrazowymi (zwanymi dalej systemami CR — computed radiography systems) i systemami z pełnopolowym detektorem cyfrowym (zwanymi DR — digital radiography systems), co miało wpływ na dawkę promieniowania X otrzymywaną przez kobiety podczas badań. Celem niniejszej pracy była ocena zmian, jakim podlegają wartości średnich dawek gruczołowych dla ekspozycji 4,5 cm PMMA (MGD4,5cmPMMA) w związku ze zmianą rodzaju rejestratora obrazu. Materiał pracy stanowiło 1499 protokołów z kontroli przeprowadzonych przez fizyków z 16 wojewódzkich ośrodków koordynujących w latach 2007, 2011, 2012 i 2013. Analiza wyników wykazała, że w kolejnych latach, począwszy od roku 2011, wartości średnie MGD4,5cmPMMA dla systemów CR były wyższe niż dla systemów SF: o 25%, 26% i o 28%; dla systemów DR były wyższe niż dla systemów SF: o 15%, 4% i o 5%; dla systemów CR były wyższe niż dla systemów DR o 13%, 23% i o 24%. Jednak we wszystkich przypadkach wartości średnie MGD4,5cmPMMA były na akceptowalnym poziomie 2,5 mGy. Średnie wartości MGD4,5cmPMMA znacznie różnią się w zależności od stosowanego rejestratora obrazu

Complex network analysis of literary and scientific texts

We present results from our quantitative study of statistical and network properties of literary and scientific texts written in two languages: English and Polish. We show that Polish texts are described by the Zipf law with the scaling exponent smaller than the one for the English language. We also show that the scientific texts are typically characterized by the rank-frequency plots with relatively short range of power-law behavior as compared to the literary texts. We then transform the texts into their word-adjacency network representations and find another difference between the languages. For the majority of the literary texts in both languages, the corresponding networks revealed the scale-free structure, while this was not always the case for the scientific texts. However, all the network representations of texts were hierarchical. We do not observe any qualitative and quantitative difference between the languages. However, if we look at other network statistics like the clustering coefficient and the average shortest path length, the English texts occur to possess more clustered structure than do the Polish ones. This result was attributed to differences in grammar of both languages, which was also indicated in the Zipf plots. All the texts, however, show network structure that differs from any of the Watts-Strogatz, the Barabasi-Albert, and the Erdos-Renyi architectures

GWAS links variants in neuronal development and actin remodeling related loci with pseudoexfoliation syndrome without glaucoma

Pseudoexfoliation syndrome (PEXS) is an age-related elastosis, strongly associated with the development of secondary glaucoma. It is clearly suggested that PEXS has a genetic component, but this has not been extensively studied. Here, a genome-wide association study (GWAS) using a DNA-pooling approach was conducted to explore the potential association of genetic variants with PEXS in a Polish population, including 103 PEXS patients without glaucoma and 106 perfectly (age- and gender-) matched controls. Individual sample TaqMan genotyping was used to validate GWAS-selected single-nucleotide polymorphism (SNP) associations. Multivariate binary logistic regression analysis was applied to develop a prediction model for PEXS. In total, 15 SNPs representing independent PEXS susceptibility loci were selected for further validation in individual samples. For 14 of these variants, significant differences in the allele and genotype frequencies between cases and controls were identified, of which 12 remained significant after Benjamini-Hochberg adjustment. The minor allele of five SNPs was associated with an increased risk of PEXS development, while for nine SNPs, it showed a protective effect. Beyond the known LOXL1 variant rs2165241, nine other SNPs were located within gene regions, including in OR11L1, CD80, TNIK, CADM2, SORBS2, RNF180, FGF14, FMN1, and RBFOX1 genes. None of these associations with PEXS has previously been reported. Selected SNPs were found to explain nearly 69% of the total risk of PEXS development. The overall risk prediction accuracy for PEXS, expressed by the area under the ROC curve (AUC) value, increased by 0.218, from 0.672 for LOXL1 rs2165241 alone to 0.89 when seven additional SNPs were included in the proposed 8-SNP prediction model. In conclusion, several new susceptibility loci for PEXS without glaucoma suggested that neuronal development and actin remodeling are potentially involved in either PEXS onset or inhibition or delay of its conversion to glaucoma

Evaluation of imaging parameters of ultrasound scanners : baseline for future testing

Background: Regular quality control is required in Poland only for those methods of medical imaging which involve the use of ionizing radiation but not for ultrasonography. It is known that the quality of ultrasound images may be affected by the wearing down or malfunctioning of equipment. Material/Methods: An evaluation of image quality was carried out for 22 ultrasound scanners equipped with 46 transducers. The CIRS Phantom model 040GSE was used. A set of tests was established which could be carried out with the phantom, including: depth of penetration, dead zone, distance measurement accuracy, resolution, uniformity, and visibility of structures. Results: While the dead zone was 0 mm for 89% of transducers, it was 3 mm for the oldest transducer. The distances measured agreed with the actual distances by 1 mm or less in most cases, with the largest difference of 2.6 mm. The resolution in the axial direction for linear transducers did not exceed 1 mm, but it reached even 5 mm for some of the convex and sector transducers, especially at higher depths and in the lateral direction. For 29% of transducers, some distortions of anechoic structures were observed. Artifacts were detected for several transducers. Conclusions: The results will serve as a baseline for future testing. Several cases of suboptimal image quality were identified along with differences in performance between similar transducers. The results could be used to decide on the applicability of a given scanner or transducer for a particular kind of examination