We introduce and discuss the test space problem as a part of the whole copula fitting process. In particular, we explain how an efficient copula test space can be constructed by taking into account information about the existing dependence, and we present a complete overview of bivariate test spaces for all possible situations. The practical use will be illustrated by means of a numerical application based on an illustrative portfolio containing the S&P 500 Composite Index, the JP Morgan Government Bond Index and the NAREIT All index.
According to the standard cosmological model, 27 % of the Universe consists of some mysterious dark matter, 68 % consists of even more mysterious dark energy, whereas only less than 5 % corresponds to baryonic matter composed from known elementary particles. The main purpose of this paper is to show that the proposed ratio 27 : 5 between the amount of dark matter and baryonic matter is considerably overestimated. Dark matter and partly also dark energy might result from inordinate extrapolations, since reality is identified with its mathematical model. Especially, we should not apply results that were verified on the scale of the Solar System during several hundreds of years to the whole Universe and extremely long time intervals without any bound of the modeling error.
We derive a curvature identity that holds on any 6-dimensional Riemannian manifold, from the Chern-Gauss-Bonnet theorem for a 6-dimensional closed Riemannian manifold. Moreover, some applications of the curvature identity are given. We also define a generalization of harmonic manifolds to study the Lichnerowicz conjecture for a harmonic manifold "a harmonic manifold is locally symmetric" and provide another proof of the Lichnerowicz conjecture refined by Ledger for the 4-dimensional case under a slightly more general setting., Yunhee Euh, Jeong Hyeong Park, Kouei Sekigawa., and Obsahuje bibliografii
The correlation between baroreflex sensitivity (BRS) and the spectrum component at a frequency of 0.1 Hz of pulse intervals (PI) and systolic blood pressure (SBP) was studied. SBP and PI of 51 subjects were recorded beat-to-beat at rest (3 min), during exercise (0.5 W/kg of body weight, 9 min), and at rest (6 min) after exercise. BRS was determined by a spectral method (a modified alpha index technique). The subjects were divided into groups according to the spectral amplitude of SBP at a frequency of 0.1 Hz. The following limits of amplitude (in mm Hg) were used: very high ≥ 5.4 (VH); high 5.4 > H ≥ 3 (H); medium 3 > M ≥ 2 (M), low < 2 (L). We analyzed the relationships between 0.1 Hz variability in PI and BRS at rest, during the exercise and during recovery in subgroups VH, H, M, L. The 0.1 Hz variability of PI increased significantly with increasing BRS in each of the groups with identical 0.1 Hz variability in SBP. This relationship was shifted to the lower values of PI variability at the same BRS with a decrease in SBP variability. The primary SBP variability increased during exercise. The interrelationship between the variability of SBP, PI and BRS was identical at rest and during exercise. A causal interrelationship between the 0.1 Hz variability of SBP and PI, and BRS was shown. During exercise, the increasing primary variability in SBP due to sympathetic activation was present, but it did not change the relationship between variability in pulse intervals and BRS., N. Honzíková, A. Krtička, Z. Nováková, E. Závodná., and Obsahuje bibliografii
A workable nonstandard definition of the Kurzweil-Henstock integral is given via a Daniell integral approach. This allows us to study the HL class of functions from . The theory is recovered together with a few new results.
A special case of a combinatorial theorem of De Bruijn and Erdős asserts that every noncollinear set of $n$ points in the plane determines at least $n$ distinct lines. Chen and Chvátal suggested a possible generalization of this assertion in metric spaces with appropriately defined lines. We prove this generalization in all metric spaces where each nonzero distance equals $1$ or $2$.
Two new species of coccidian parasites are described from African reptiles. Oocysts of Eimeria foulshami sp. n. from the plated lizard Gerrhosaurus major bottegoi Del Prato of Sudan are ellipsoidal, 24.1 × 14.9 (23-26.5 × 14-17.8) µm with a bilayered, colourless oocyst wall and lack polar granules. The ellipsoidal sporocysts average 8.6 × 4.6 (7-10.6 × 4.4-7) µm and possess a prominent, globular, sporocyst residuum. Oocysts of Caryospora regentensis sp. n. from the green mamba Dendroaspis viridis Hallowell of Kenya are spherical to subspherical, 16.8 × 16.4 (16-17.6 × 15-17.2) µm with a bilayered oocyst wall and a single polar granule. The ellipsoidal sporocysts average 13.0 × 10.3 (10.2-14 × 9.2-11) µm and possess a Stieda and substieda body and a prominent globular sporocyst residuum. Oocysts of Caryospora legeri Hoare, 1933 are reported from a hissing sand snake, Psammophis sibilans sibilans L. from Nigeria, representing a new geographical record. The oocysts are slightly larger than the type, but otherwise identical. Caryospora psammophi Bray, 1960 and C. hermae Bray, 1960 from Psammophis sibilans phillipsi, oocysts of which are morphologically similar to and overlap in dimensions with C. legeri Hoare, 1933, are synonymised with the latter species. Eimeria samiae Iskander et Tadros, 1979 is emended to E. samyadeli to reflect the gender of the person the species was named after and because E. sami is preoccupied. In addition to these findings, Eimeria bohemi Modrý, Šlapeta et Koudela, 2000 and oocysts of an unidentified spherical Eimeria sp. are reported from Chamaeleo dilepis dilepis Leach from Cameroon.
We have developed a PCR assay that in a single reaction distinguishes between Leishmania infantum and Leishmania donovani strains on the basis of different size of the amplicon. The targeted intergenic region between putative biopterin transporter and nucleotide binding protein on chromosome 35 is highly variable, species-specific and can be amplified from clinical samples. Based on the assay, five tested Leishmania archibaldi and L. infantum strains from the Sudan and Ethiopia clearly belong to L. donovani, which is in accordance with a recent multifactorial analysis of these strains. The nucleotide sequence reported in this paper has been submitted to the GenBankTM with accession number EU068004.