The mountain type of climate, which is typical for the Sudety Mountains, is well known for its rapid and frequent changes in pressure, temperature and humidity. The fluctuations in meteorological parameters cause fast changes of the tropospheric delay, as a correlated value, and in consequence difficulties in GPS heights determination. The tropospheric delay is a function of the meteorological parameters obtained directly from synoptic stations and models. The paper presents the procedure of tropospheric delay estimation on the European Permanent Network and International GNSS Service (EPN/IGS) stations, using meteorological observations from synoptic stations (Wrocław Airport, Śnieżka) of the Polish Meteorology Service (IMGW), stations (Cervena, Praha-Kbely) of the Czech Hydrometeorological Institute (CHMU), and sensors mounted close to the antennas of the permanent GNSS stations (BISK, SNEC, WROC, GOPE). The values obtained from Global Pressure and Temperature (GPT) model were bases for the meteorological data calibration at EPN/IGS stations. The tropospheric delay (Zenith Total Delay - ZTD) on EPN/IGS stations was obtained from Saastamoinen formula and compared with ZTD from EPN solutions., Witold Rohm and Jarosław Bosy., and Obsahuje bibliografické odkazy
7β-hydroxy-epiandrosterone (7β-OH-EpiA) is an endogenous androgen metabolite that has been shown to exert neuroprotective, anti-inflammatory and anti-estrogenic effects. However, to the best of our knowledge no information is available about this androgen steroid in relation to sperm quality. We analyzed 7β-OH-EpiA in plasma and seminal plasma using a newly developed isotope dilution ultra-high performance liquid chromatography - mass spectrometry method. Validation met the requirements of FDA guidelines. Levels of 7β-OH-EpiA were measured in 191 men with different degrees of infertility. One-way analysis of variance followed by multiple comparison and correlation analysis adjusted for age, BMI and abstinence time were performed to evaluate the relationships between this steroid and sperm quality. Concentrations of 7β-OH-EpiA in seminal plasma were significantly higher in severely infertile men in comparison with healthy men and slightly infertile men. The same trend was found when blood plasma was evaluated. Furthermore, plasma 7β-OH-EpiA negatively correlated with sperm concentration (-0.215; p<0.01) and total count (-0.15; p<0.05). Seminal 7β-OH-EpiA was negatively associated with motility (-0.26; p<0.01), progressively motile spermatozoa (-0.233; p<0.01) and nonprogressively motile spermatozoa (-0.188; p<0.05). 7β-OH-EpiA is associated with lower sperm quality and deserves more research in that respect., J. Vitku, L. Kolatorova, C. Ricco, C. Ferroud, O. Hennebert, T. Skodova, J. Heracek, L. Starka., and Obsahuje bibliografii
We consider the solution operator $S\:\mathcal F_{\mu ,(p,q)}\rightarrow L^2(\mu )_{(p,q)}$ to the $\bar{\partial }$-operator restricted to forms with coefficients in $\mathcal F_{\mu }= \bigl \lbrace f\: f \text{is} \text{entire} \text{and} \int _{\mathbb{C}^n} |f(z)|^2\mathrm{d}\mu (z) <\infty \bigr \rbrace $. Here $\mathcal F_{\mu ,(p,q)}$ denotes $(p,q)$-forms with coefficients in $\mathcal F_{\mu }$, $L^2(\mu )$ is the corresponding $L^2$-space and $\mu $ is a suitable rotation-invariant absolutely continuous finite measure. We will develop a general solution formula $S$ to $\bar{\partial }$. This solution operator will have the property $Sv\bot \mathcal F_{(p,q)}\, \forall \,v \in \mathcal F_{(p,q+1)}$. As an application of the solution formula we will be able to characterize compactness of the solution operator in terms of compactness of commutators of Toeplitz-operators $[T_{\bar{z_i}},T_{z_i}]= [T^*_{{z_i}},T_{z_i}]\:\mathcal F_\mu \rightarrow L^2(\mu )$.
Since the 19th century, crafts for Japan have been as important for trade and the economy as they have been for national and cultural identity. The discourse of "Japaneseness" has been central to the national and public debate in the craft world. As the Japanese empire expanded into North East China in the 1930s, Japan became interested in the cultures of greater China, including Taiwan. Japan´s continuous obsession with the idea of the "Japaneseness" in craft products was complicated by its effort to redefine itself in terms of its "Orientalness". This involved the location of its identity within the three-way positioning of Occident-Jaoan-Orient rather than the simple binary position of Japan versus the Occident. This aper firstly examines how Japanese craft and design experts confronted these multiple and different shades of the Orient and constructed the notion of "Japaneseness" as part of the Orient in the design discourse. Secondly, it will investigate the Japan centric hybrid design concept of "Greater Oriental Design", articulated by Japan as the leading power and authority of crafts in Asia. Finally, this paper will explore how this design discourse and these concepts were creatively interpreted in actual design terms and in experimentation, as well as the resulting implications for Japanese design history.
Suppose that some polynomial f with rational coefficients takes only natural values at natural numbers, i. e., L={f(n)∣n∈N}⊆N. We show that the base-q representation of L is a context-free language if and only if f is linear, answering a question of Shallit. The proof is based on a new criterion for context-freeness, which is a combination of the Interchange lemma and a generalization of the Pumping lemma.
The concept of rank of a commutative cancellative semigroup is extended to all commutative semigroups S by defining rank S as the supremum of cardinalities of finite independent subsets of S. Representing such a semigroup S as a semilattice Y of (archimedean) components Sα, we prove that rank S is the supremum of ranks of various Sα. Representing a commutative separative semigroup S as a semilattice of its (cancellative) archimedean components, the main result of the paper provides several characterizations of rank S; in particular if rank S is finite. Subdirect products of a semilattice and a commutative cancellative semigroup are treated briefly. We give a classification of all commutative separative semigroups which admit a generating set of one or two elements, and compute their ranks.
Suppose that A is a real symmetric matrix of order n. Denote by m_{A}(0) the nullity of A. For a nonempty subset α of {1, 2,..., n}, let A(α) be the principal submatrix of A obtained from A by deleting the rows and columns indexed by α. When m_{A(\alpha )}(0) = m_{A}(0)+|α|, we call α a P-set of A. It is known that every P-set of A contains at most \left \lfloor n/2 \right \rfloorelements. The graphs of even order for which one can find a matrix attaining this bound are now completely characterized. However, the odd case turned out to be more difficult to tackle. As a first step to the full characterization of these graphs of odd order, we establish some conditions for such graphs G under which there is a real symmetric matrix A whose graph is G and contains a P-set of size (n − 1)/2., Zhibin Du, Carlos M. da Fonseca., and Obsahuje seznam literatury
The article introduces the results achieved in the creation of feasible assemblies of NdFeB magnets assembled following an already published design of a practical arrangement of magnets derived from an ideal magnetization pattern, leading to the strongest possible stray field at a remote point. It presents a method of the implementation of these assembled sets and the relevant measured dependences of magnetic induction By = f(y) and By = f(x) including their comparison with already published dependences determined by a simulation. It further presents similar dependences of magnetic induction found in the case of a trial magnetic circuit with large blocks from NdFeB magnets, and these dependences are compared both with the mentioned computer-determined dependences and the dependences measured with the corresponding implemented assembly of magnets., Václav Žežulka and Pavel Straka., and Obsahuje bibliografii
The aim of this study was to gain more complete information about the relationships between some endogenous antioxidants and the malondialdehyde (MDA) as a marker of lipid peroxidati on, during D -galactose induced senescence. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and the concentrations of uric acid (UA) in plasma and MDA in erythrocyte’s hemolysate, were determined in 15 D -galactose (D-gal), treated rats and compared with 15 placebo. The activity of the erythrocyte’s CAT was found significantly increased due to the senescence. The ratio of the activities of antioxidant enzymes R =SOD/(GPx+CAT) was significantly decreased due to the sen escence and negatively correlated with the MDA ( ρ = -0.524, p=0.045). The antioxidant enzymes SOD and GPx negatively correlated with the MDA, while CAT displayed no correlation. Further, the UA positively correlated with the ratio of activities of the antioxidant enzymes R=SOD/(GPx+CAT), ( ρ =0.564, p=0.029 for senescent rats). Obtained results may contribute t o better understanding of the process of D-gal induced senescence in the erythrocytes., M. Mladenov, M. Gokik, N. Hadzi-Petrushev, I. Gjorgoski, N. Jankulovski., and Obsahuje bibliografii
a1_In a series of studies in the late 1950s and early 1960s, Jan Bures introduced cortical spreading depression to the field of behavioral neuroscience (eg. Bures 1960). This technique offered a unique way to study the role of cortex in learning and memory, and attracted the attention of many who began their graduate studies at that time, including one of us (LN, cf. Nadel 1966). An NIH postdoctoral fellowship to study with the master himself brought LN to Prague in September 1967. Thus began a relationship that included science, politics, and personal life, and has lasted over 30 years1,2. The first scientific exchange began with Jan pulling a piece of paper from his desk with a long list of possible experiments written on it -- “pick one”, he said. This led to a series of studies on interhemispheric transfer of learning under conditions of monocular input, demonstrating, amongst other things, that such transfer is not a uniform process. Depending on the kind of trials given with both hemispheres intact, and the eye which remained open to input, transfer can either be non-specific, likely involving some kind of procedural knowledge, or highly specific, likely involving knowledge about the trained discrimination itself (Nadel and Buresova, 1970). These studies anticipated LN’s future work on multiple memory systems, a research enterprise pursued in the following decades by many labs (including LN’s: e.g. Nadel and O’Keefe 1974, O’Keefe et al. 1975). In this paper we focus on several scientific issues that Jan has been thinking about for the past 25 years. In particular, we consider spatial learning, the hippocampus, and memory. To this mix we add stress, something well known to anyone living in Prague in 1968., a2_LN left Prague after the 1968 invasion and stayed in London for seven months, during which time arrangements were made for an eventual return to the Medical Research Council Cerebral Functions Research Group in 1970. Thus it was that LN happened to be down the hall when John O’Keefe and Jonathan Dostrovsky discovered place cells (O’Keefe and Dostrovsky 1971) and began the program of research leading to the cognitive map theory of hippocampal function (O’Keefe and Nadel 1978)., L. Nadel, J.D. Payne., and Obsahuje bibliografii