The entropy region is a fundamental object of study in mathematics, statistics, and information theory. On the one hand, it involves pure group theory, governing inequalities satisfied by subgroup indices, whereas on the other hand, computing network coding capacities amounts to a convex optimization over this region. In the case of four random variables, the points in the region that satisfy the Ingleton inequality (corresponding to abelian groups and to linear network codes) form a well-understood polyhedron, and so attention has turned to Ingleton-violating points in the region. How far these points extend is measured by their Ingleton score, where points with positive score are Ingleton-violating. The Four-Atom Conjecture stated that the Ingleton score cannot exceed 0.089373, but this was disproved by Matúš and Csirmaz. In this paper we employ two methods to investigate Ingleton-violating points and thereby produce the currently largest known Ingleton scores. First, we obtain many Ingleton-violating examples from non-abelian groups. Factorizability appears in many of those and is used to propose a systematic way to produce more. Second, we rephrase the problem of maximizing Ingleton score as an optimization question and introduce a new Ingleton score function, which is a limit of Ingleton scores with maximum unchanged. We use group theory to exploit symmetry in these new Ingleton score functions and the relations between them. Our approach yields some large Ingleton scores and, using this methodology, we find that there are entropic points with score 0.09250007770, currently the largest known score., Nigel Boston and Ting-Ting Nan., and Obsahuje bibliografické odkazy
During a survey of the coccidian parasites of reptiles, caryosporan oocysts were found in the faeces of wild and captive European viperid snakes Vipera berus (L.) and V. ammodytes (L.). Thirty two of 37 examined V. herus (86%) and 9 of 17 examined V. ammodytes (53%) specimens were found to be passing caryosporan oocysts. Morphological characters of all caryosporan isolates were identical and fitted well with the description of Caryospora simplex Léger, 1904. Experimental inoculation of severe combined immunodeficient (SC1D) mice with seven isolates of C. simplex from V. berus or V. ammodytes confirmed the heteroxenous life cycle pattern, for the first time for isolates of evidently European origin. Caryosporan developmental stages were observed in the connective tissues of the nose, cheeks, ear and scrotum in all inoculated SCID mice. V. berus and V. ammodytes represent new hosts for C. simplex. The present paper represents the first widely based report on coccidian parasites of the genus Caryospora Léger in European viperids. Our findings indicate a wide distribution of C. simplex throughout the range of distribution of snakes of the genus Vipera.
Mechanical behavior of biological structures under dynamic loading generally depends on elastic as well as viscous properties of biological materials. The significance of “viscous” parameters in real situations remains to be elucidated. Behavior of rheological models consisting of a combination of inertial body and two Voigt’s bodies were described mathematically with respect to inverse problem solution, and behavior in impulse and harmonic loadings was analyzed. Samples of walls of porcine and human aorta thoracica in transverse direction and samples of human bone (caput femoris, substantia compacta) were measured. Deformation responses of human skin in vivo were also measured. Values of elastic moduli of porcine aorta walls were in the interval from 102 kPa to 103 kPa, values of viscous coefficients were in the interval from 102 Pa.s to 103 Pa.s. The value of shear stress moduli of human caput femoris, substantia compacta range from 52.7 to 161.1 MPa, and viscous coefficients were in the interval from 27.3 to 98.9 kPa.s. The role of viscous coefficients is significant for relatively high loading frequencies - in our materials above 8 Hz in aorta walls and 5 Hz for bones. In bones, the viscosity reduced maximum deformation corresponding to short rectangular stress., M. Kuchařová, S. Ďoubal, P. Klemera, P. Rejchrt, M. Navrátil., and Obsahuje bibliografii
Visfatin is a multi-functional molecule that can act intracellularly and extracellularly as an adipokine, cytokine and enzyme. One of the main questions concerning visfatin is the mechanism of its secretion; whether, how and from which cells visfatin is released. The objective of this in vitro study was to observe the active secretion of visfatin from 3T3-L1 preadipocytes and adipocytes, HepG2 hepatocytes, U-937, THP-1 and HL-60 monocytes and macrophages. The amount of visfatin in media and cell lysate was always related to the intracellular enzyme, glyceraldehyde-3- phosphate dehydrogenase (GAPDH), to exclude the passive release of visfatin. Visfatin was not found in media of 3T3-L1 preadipocytes. In media of 3T3-L1 adipocytes and HepG2 hepatocytes, the ratio of visfatin to the amount of GAPDH was identical to cell lysates. Hence, it is likely that these cells do not actively secrete visfatin in a significant manner. However, we found that significant producers of visfatin are differentiated macrophages and that the amount of secreted visfatin depends on used cell line and it is affected by the mode of differentiation. Results show that 3T3-L1 adipocytes and HepG2 hepatocytes released visfatin only passively during the cell death. U-937 macrophages secrete visfatin in the greatest level from all of the tested cell lines., P. Svoboda, E. Křížová, K. Čeňková, K. Vápenková, J. Zídková, V. Zídek, V. Škop., and Obsahuje bibliografii
Visual cognitive responses (P300) to moving stimuli were tested in 36 subjects with the aim to find the normal range of P300 parameters. Concomitantly, the circadian intra-individual variability of the P300 was studied in a subgroup of 6 subjects. Visual stimuli consisted of either coherent (frequent stimulus) or non-coherent motion (random stimulus). The oddball paradigm was applied for recording cognitive responses. P300 to rare stimuli had an average latency of 447.3±46.6 ms and amplitude of 12.9±6.0 mV. The average reaction time was in the range from 322 to 611 ms and there was no correlation between the reaction time and P300 latency. We did not find any significant circadian changes of the P300 parameters in the 6 subjects tested four times during the same day. Cognitive (event-related) responses (P300) displayed distinctly greater inter-individual variability (S.D. of 50 ms) when compared with pattern-reversal and motion-onset VEPs (S.D. of 6.0 ms and 14 ms, respectively). For this reason, the clinical use of P300 elicited by this kind of visual stimuli seems to be rather restricted and the evaluation of its intra-individual changes is preferable., Z. Kubová, J. Kremláček, J. Szanyi, J. Chlubnová, M. Kuba., and Obsahuje bibliografii
The West Bohemia earthquake swarm foci are approximated by a circular seismic source model, which radius is assumed to depend only on magnitude of the event. We consider two different models of average slip (i) a constant slip and (ii) a slip exponentially scaled to the magnitude of the event. Based on these assumptions, we stacked the contributions of individual events into representative final fault slip. We processed in such a way four significant swarms recorded during the last three decades in 1986, 1997, 2000 and 2008. Constant slip model indicates final slip was composed of 2 or 3 principal asperities located on one or two different planes. On the contrary, scaled slip model indicates that one big asperity prevails. It is not possible yet to select the preferred slip model. Analysis of the temporal activity of all swarms generally shows three principal phases: starting phase, main phase and fading phase; the upwards trend of activity spreading was observed (slip animation is presented in www supplement http://www.ig.cas.cz/kolar/StopPhase/Asperity). The maximal possible cumulative slip value may have reached the order of meters., Petr Kolář, Bohuslav Růžek, Alena Boušková and Josef Horálek., and Obsahuje bibliografii
In this review we summarize recent opinions on the possible role of vitamin D in the risk of thyroid diseases development. It may be concluded from the available data that vitamin D deficiency, particularly levels below 12.5 ng/ml should be considered as an additional, but important risk factor for development of thyroid autoimmunity, both chronic autoimmune thyroiditis and Graves´ disease. A higher risk of Graves´ disease development is also associated with several polymorphisms in the gene encoding for vitamin D binding protein and for the specific receptor of active form of vitamin D - 1,25-(OH)2D3 in the respective target cells. Important for development of thyroid cancer appeared polymorphisms of genes encoding for vitamin D receptors and of genes encoding for the participating hydroxylating enzymes in thyroid tissue, leading to a diminished local 1,25-(OH)2D3 formation capacity with following alteration of antiproliferatory, antiapoptotic and prodifferentiating efficacy of the latter. Whether supplementation with high doses of vitamin D or its analogues possesses preventive or therapeutic effect is an object of intensive studies., K. Vondra, L. Stárka, R. Hampl., and Obsahuje bibliografii
Reduced levels of vitamin or its metabolites have been reported in various psychiatric disorders. Insufficient levels of vitamin D in depressive patients have been confirmed by many authors, but there have been conflicting results in subjects with anxiety disorders. In the present cross-sectional study, levels of calcidiol were determined in groups of depressive men and women and in men and women with anxiety disorders and compared with age matched controls. Significantly lower levels of calcidiol were found in men and women with depression as well as in age matched patients with anxiety disorders., M. Bičíková, M. Dušková, J. Vítků, B. Kalvachová, D. Řípová, P. Mohr, L. Stárka., and Obsahuje bibliografii
The relationship between vitamin D receptor (VDR) intragenic polymorphisms FokI, BsmI, ApaI and TaqI and bone mineral density (BMD) or biochemical markers of bone remodeling were investigated in 114 Czech postmenopausal women, on the average 62.5±8.9 years of age. Restriction fragment length polymorphisms in the VDR gene were assessed by PCR amplification and digestion with restriction enzymes FokI, BsmI, ApaI, and TaqI recognizing polymorphic sites in the VDR locus. Bone mineral density was measured at the lumbar spine and at the hip by dual-energy X-ray absorptiometry (DEXA, g/cm2). After adjusting for age and the body mass index (BMI), subjects with the ff genotype had 9.4 % lower BMD at the hip than those with the Ff genotype (p=0.0459, Tukey´s test). FF individuals had an intermediate BMD at the hip. A similar pattern of lower lumbar spine BMD was also found in ff individuals, but it did not reach statistical significance. There was no relationship between BsmI, ApaI and TaqI VDR polymorphisms and BMD at any skeletal site. Subjects with Aa (ApaI) genotypes had higher levels of propeptide of type I collagen (PICP) than homozygous AA (p=0.0459, Tukey´s test). In FokI, BsmI and TaqI restriction sites the biochemical markers of bone remodeling did not differ by genotype. In addition, no significant difference was observed in VDR genotypic distribution between osteoporotic women and non-osteoporotic controls in the study group. To conclude, the FokI genotype of the vitamin D receptor gene is related to bone mass at the hip in Czech postmenopausal women, whereas the importance of remaining VDR genotypes was not evident., K. Zajíčková, I. Žofková, R. Bahbouh, A. Křepelová., and Obsahuje bibliografii
In women with chronic autoimmune thyroiditis and vitamin D deficiency we have found reference levels of relevant metabolichormonal parameters except for parathormone and total calcium. Three months supplementation with vitamin D (4300 IU/day, cholekalciferol) did not lead to significant changes of investigated hormonal parameters, while the levels of parathormone and calcium reached normal levels. However, a correlation analysis revealed marked changes in mutual relations. First, an inverse correlation of vitamin D with parathormone, insulin secretion (C peptide, insulin) and its efficiency (HOMA IR) disappeared. Relationships of vitamin D to hepatic insulin resistance (insulin/C peptide), to DHEA (both negative), and to DHEAS/DHEA ratio (positive) were newly found. Second, a positive correlation of CRP with insulin secretion remained, while its relation to insulin efficiency (HOMA IR, insulin/ C peptide) was newly observed. Analogical positive correlations appeared also among anti TPO and insulinemia, insulin/C peptide, HOMA IR, and anti Tg to C peptide. A relationship of the CRP with anti TPO became significant (+). Third, out of glucose metabolism parameters only insulin/C peptide and glycemia did not correlate with vitamin D during its deficiency, while after supplementation insulin/ C peptide alone correlated positively with both DHEAS and DHEA, and negatively with vitamin D., K. Vondra, R. Bílek, P. Matucha, M. Salátová, M. Vosátková, L. Stárka, R. Hampl., and Obsahuje bibliografii