Podle tradice přenesl geometrii do Řecka Thalés z Mílétu. Ačkoli v diskusích o povaze Thalétovy geometrie nepanuje konsensus, zdá se, že zformulované teorémy byly až dodatečně uplatněny na jeho konkrétní měření. Již o Thalétově „žákovi a nástupci“, Anaximandrovi z Mílétu, však nemáme žádné zprávy, které by se týkaly geometrie. Výjimku představuje lexikon Súda, který uvádí, že Anaximandros „vůbec ukázal základy geometrie“. Lexikon zároveň vyjmenovává momenty, v nichž může být užití geometrie spatřeno. V prvé řadě se jedná o gnómón, s jehož pomocí mohla být realizována řada měření. Zřejmé znaky uplatnění geometrie vykazuje též celá Anaximandrova koncepce kosmologie: tvar Země a její umístění ve středu univerza, i samotný popis nebeských těles. Podobně lze uplatnění geometrie spatřovat za mapou světa a sférou. Ačkoli tedy Anaximandros není explicitně s geometrií spojován, dochované texty ukazují, že její poznatky významně využil, když propojil konkrétní pozorování s geometrickým uspořádáním celého univerza., According to tradition Thales brought geometry to Greece from Miletus. Although discussion of the nature of Thales’ geometry has not arrived at a consensus, it seems that the theorems formulated were retrospectively applied in his concrete measurements. So far, however, we have no information about the geometry of Thales’ pupil and successor, Anaximander of Miletus. An exception is presented in the lexicon Suda which claims that Anaximander “in general showed the basics of geometry”. This lexicon at the same time states the points at which the employment of the geometry can be discerned. Most importantly, we have the question of the gnomon, with the help of which an order of measurement is realisable. Clear signs of the application of geometry are likewise shown by Anaximander’s whole conception of cosmology: the shape of the earth and its position at the centre of the universe, and the very description of the heavenly bodies. In addition one can discern geometry involved in the map of the world and the sphere. Thus, although Anaximander is not explicitly connected with geometry, extant texts demonstrate that he significantly exploited geometrical knowledge when he connected concrete observation with the geometrical organisation of the universe as a whole., and Radim Kočandrle.
Structural changes of thoracic aorta (TA), carotid (CA) and iliac artery (IA) were assessed in Wistar and spontaneously hypertensive rats (SHR) aged 3, 17, and 52 weeks. Systolic blood pressure (sBP) was measured by plethysmography weekly. After perfusion fixation the arteries were processed for electron microscopy. The wall thickness (WT), cross-sectional area (CSA), inner diameter (ID), and WT/ID in all arteries and volume densities of endothelial cells (ECs), muscle cells (SMCs), and extracellular matrix (ECM) in TA were measured and their CSAs were calculated. In 3-week-old SHR compared to Wistar rats, sBP did not differ; in the TA, all parameters (WT, CSA, ID, WT/ID, CSA of SMCs, CSA of ECs, and CSA of ECM) were decreased; in CA, WT and CSA did not differ, ID was decreased, and WT/ID was increased; in IA, WT, CSA, and ID were increased. In 17- and 52-week-old SHRs, sBP and all parameters in all arteries were increased, only ID in IE in 52-week-old SHRs and CSA of ECs in the TA in 17-week-old SHRs did not change. Disproportionality between BP increase and structural alterations during ontogeny in SHR could reflect the flexibility of the arterial tree to the different needs of supplied areas.
We construct a class of special homogeneous Moran sets, called {mk}-quasi homogeneous Cantor sets, and discuss their Hausdorff dimensions. By adjusting the value of {mk}k\geqslant 1, we constructively prove the intermediate value theorem for the homogeneous Moran set. Moreover, we obtain a sufficient condition for the Hausdorff dimension of ho- mogeneous Moran sets to assume the minimum value, which expands earlier works., Xiaomei Hu., and Obsahuje seznam literatury
The aim of this article is to sketch a certain method of indirect reconstruction of the process by which mathematics as a deductive discipline emerged in ancient Greece. We try out this method in a reconstruction of Thales' mathematics, but the main aim for which this method has been developed is the work of Pythagoras. We consider the process of the emergence of mathematics as a process of the constitution of a new language in the framework of which one can carry out deductive proofs. Therefore we base the method of indirect reconstruction of the emergence of mathematics on the theoretical findings in the book L. Kvasz: Vedecká revolúcia ako lingvistická událosť (The Scientific Revolution as a linguistic event, Prague, Filosofia 2013)., Ladislav Kvasz., and Obsahuje poznámky a bibliografii
This review compares the geometry of conduit coronary arteries in man and animals, namely the wall/diameter ratio (1:7.4 and 1:15 respectively). The left and right ventricle volume determines the geometry (segment length and diameter) of both branches of the left coronary artery: ramus interventricularis anterior and ramus circumflexus; the range of deformation of the latter was substantially smaller. The heterogeneity of deformation was also found along the ramus interventricularis anterior, the deformation decreasing towards the apex. The above relations have consequences (i) on the haemodynamics (passive changes in conduit segment resistance), (ii) the deformation of coronary arteries triggers metabolic processes in the coronary wall. Four hours' lasting cardiac volume or pressure overload brought about an increase in the RNA content not only in the myocardium, but also in the coronary artery. The process is reversible. Moreover, the range of the RNA increase is in full concert with the heterogeneous deformability of the respective segment of the coronary tree.