The present-day mass function (PDMF) of field stars in the solar neighborhood is discussed. Major uncertainties in the derivation exist, in partlcular the luminosity-mass relation and the bolometric corrections. Consequently, It is not clear whether the PDMF turns over at very low masses (M < 0.3 Mq), and the slope at the
high-mass end (M > 10 Mq) is more uncertain than usually assumed. The reality of two features in the PDMF (at M = 1.2 Mq and M = 3 Mq respectively) is an open question. Next, the concept of a bimodal IMF is critically examined. Both Gůsten and Mezger's (1983) and Larson's (1986) bimodal models may run into problems. If the effects of high-mass stars prevent low-mass stars from forming, the term "biassed IMF" is a better
description of the situation than "bimodal IMF". The IMF is probably not universal; reported IMF variations in open clusters and globular clusters are unlikely to be spurious. Finally the physics of the IMF is discussed. The. fact that the mass of a star in the making depends on many random-valued (multlplicative) input parameters
suggests a stochastic rather than a deterministic approach for the origin of the IMF.
Some results about the continuity of special linear maps between $F$-spaces recently obtained by Drewnowski have motivated us to revise a closed graph theorem for quasi-Suslin spaces due to Valdivia. We extend Valdivia's theorem by showing that a linear map with closed graph from a Baire tvs into a tvs admitting a relatively countably compact resolution is continuous. This also applies to extend a result of De Wilde and Sunyach. A topological space $X$ is said to have a (relatively countably) compact resolution if $X$ admits a covering $\{A_{\alpha }\:\alpha \in \Bbb N^{\Bbb N}\}$ consisting of (relatively countably) compact sets such that $A_{\alpha }\subseteq A_{\beta }$ for $\alpha \leq \beta $. Some applications and two open questions are provided.
A recent infestation of Gyrodactylus cichlidarum Paperna, 1968 on yolk sac fry of Nile tilapia, Oreochromis niloticus niloticus (L.), in an isolated aquarium system in the UK resulted in high mortalities and provided an opportunity to study this species in greater detail. A tentative identification was made using the measurements and drawings of the ventral bar and hamuli provided in the original description; however, details on the morphology of the marginal hooks were lacking. A comparison of the gyrodactylid material collected from O. n. niloticus with the holotype of G. cichlidarum, the only known available specimen, from Mango tilapia, Sarotherodon galilaeus galilaeus (L.), confirmed its identity. Proteolytic digestion and image analysis of the opisthaptoral hard parts were used to obtain tissue-free, accurate measurements as part of a complete revised description of G. cichlidarum. Further, a comparison of G. cichlidarum from both hosts with the holotype and several paratypes of Gyrodactylus niloticus Cone, Arthur et Bondad-Reantaso, 1995 cited as parasitizing captive stocks of Nile tilapia in the Philippines revealed the two species to be synonymous. An 803 bp fragment of the ribosomal internal transcribed spacers 1 and 2 and the 5.8S was obtained and is provided with the revised description. This is the first DNA sequence from a Gyrodactylus species originating from the African continent. The sequence is very divergent from other species in the genus and only the 5.8S sequence places it unambiguously in the genus Gyrodactylus. In addition to G. cichlidarum, two specimens of another morphological similar species of Gyrodactylus were also found on the UK held stock of O. n. niloticus. These latter specimens, Gyrodactylus sp., differed from G. cichlidarum in having a longer hamulus point with a smaller hamulus aperture and possessing marginal hook sickles that had a shorter shaft with a longer point giving the sickles a more rounded, closed appearance.
Using ideas from John Searle, Roy Harris, Michael Reddy, and Nelson Goodman, I argue that texts, such as they are commonly conceived, lack brute existence. The common idea of texts is a conceptual construction which is useful in practical everyday contexts but not in serious theorizing, where it creates illusions and contradictions. One of these illusions is the idea of an objective textual meaning, a meaning which is ''in the text'': what we actually have in the way of textual meaning are the ideas of various persons – authors, readers, and commentators – about the meaning of the text. When applied to fictional characters, this way of viewing things explains why it makes sense to regard fictional characters as being created and as lacking brute existence., Použitím nápadů od Johna Searleho, Roy Harris, Michaela Reddyho a Nelsona Goodmana, tvrdím, že texty, tak jak jsou běžně koncipovány, postrádají hrubou existenci. Společná myšlenka textů je koncepční konstrukce, která je užitečná v praktických každodenních kontextech, ale ne ve vážném teoretizování, kde vytváří iluze a protiklady. Jednou z těchto iluzí je myšlenka objektivního textuálního významu, významu, který je "v textu": to, co vlastně máme ve způsobu textuálního významu, jsou myšlenky různých osob - autorů, čtenářů a komentátorů - o významu textu. Při použití na fiktivní postavy vysvětluje tento způsob prohlížení věci, proč má smysl považovat fiktivní postavy za vytvořené a chybějící hrubou existenci., and Anders Pettersson
This essay outlines a generalized Riemann approach to the analysis of random variation and illustrates it by a construction of Brownian motion in a new and simple manner.
Hypoxic pulmonary vasoconstric tion (HPV) is an important homeostatic mechanism in which increases of [Ca2+] i are primary events. In this study, primary cultured, human pulmonary artery smooth muscle cells (hPASMC) were used to examine the role of TRPC channels in mediating [Ca2+] i elevations during hypoxia. Hypoxia (PO2 about 20 mm Hg) evoked a transient [Ca2+] i elevation that was reduced by removal of extracellular calcium. Nifedipine and verapamil, blockers of vo ltage-gated calcium channels (VGCCs), attenuated th e hypoxia-induced [Ca2+] i elevation by about 30 %, suggesting the presence of alternate Ca2+ entry pathways. Expression of TRPC1 an d TRPC6 in hPASMC were found by RT-PCR and confirmed by Western blot analysis. Antagonists for TRPC, 2APB and SKF96365, significantly reduced hypoxia-induced [Ca2+] i elevation by almost 60 %. Both TRPC6 and TRPC1 were knocked down by siRNA, the loss of TRPC6 decreased hypoxic response down to 21 % of control, whereas the knockdown of TRPC1 reduced the hypoxia respon se to 85 %, suggesting that TRPC6 might play a central role in mediating hypoxia response in hPASMC. However, blockade of PLC pathway caused only small inhibition of the hypoxia response. In contrast, AICAR, the agonist of AMP-activated kinase (AMPK), induced a gradual [Ca2+] i elevation, whereas compound C, an antagonist of AMPK, almost abolished the hypoxia response. Ho wever, co-immunoprecipitation revealed that AMPK α was not colocalized with TRPC6. Our data supports a role for TRPC6 in mediation of the [Ca2+] i elevation in response to hypoxia in hPASMC and suggests that this response may be linked to cellular energy status via an activation of AMPK., C. Tang, W. K To, F. Meng, Y. Wang, Y. Gu., and Obsahuje bibliografii
The aim of this contribution is to study the role of the coefficient r in the qualitative theory of the equation (r(t)Φ(y ∆))∆+p(t)Φ(y σ ) = 0, where Φ(u) = |u| α−1 sgn u with α > 1. We discuss sign and smoothness conditions posed on r, (non)availability of some transformations, and mainly we show how the behavior of r, along with the behavior of the graininess of the time scale, affect some comparison results and (non)oscillation criteria. At the same time we provide a survey of recent results acquired by sophisticated modifications of the Riccati type technique, which are supplemented by some new observations.
This paper describes the reliability analysis of a concrete containment for VVER 440 under a high internal overpressure. The probabilistic safety assessment (PSA) level 3 aims at an assessment of the probability of the concrete structure failure under the excessive overpressure. The non-linear analysis of the concrete structure was considered. The uncertainties of the loads level (long-time temperature and dead loads), the material model (concrete cracking and crushing, behavior of the reinforcement and liner), degradation effects and other influences following from the inaccuracy of the calculated model and numerical methods were taken into account in the response surface method (RSM). The results of the reliability analysis of the NPP structues are presented. and Obsahuje seznam literatury