Holanďan Christiaan Huygens významně přispěl k rozvoji mechaniky a optiky v návaznosti na problémy, které řešila astronomie. Je vynálezcem kyvadlových hodin, nejpřesnějšího časoměrného přístroje doby umožňujícího poprvé stanovení zeměpisné délky plujících lodí., The article deals with the life and work of Dutch astronomer, physicist and mathematician Christiaan Huygens. Describing his extensive scientific work, we start with his activities in the field of observational astronomy (e.g. the discovery of the rings and moon of Saturn and the summary of the existing knowledge of the planets in his publication Cosmotheoros). His discovery and quantitative description of centrifugal force contributed significantly to solving problems describes in Newton´s Principia. Huygens is also well-known as a technician and technical designer. He constructed the first pendulum clocks. Last but not least, we describe his work on the impact of solid bodies, when he reflected on the work of R. Descartes and J. Marek Marci., František Jáchim., and Obsahuje seznam literatury
Sofia Kovalevskaya was not only a great Russian mathematician, but also a writer and advocate of women's rights in the 19th century. After concluding her sexondary schooling, Sofia was determined to continue her education at the university level. She travelled to Heidelberg to study mathematics, but discovered there that as a woman she could not graduate. In 1870 she moved to Berlin to study with Karl Meierstrass, in 1874 she was granted a Ph.D. from the Göttingen University. In 1883 she received an invitation from Gösta Mittag-Leffler to lecture at the University of Stockholm. Sophia's most famous work is on the theory of partial differential equations, and on the rotation of a solid body about a fixed point. Sophia died very young, at the age of 41, from pneumonia., Ivo Kraus., and Obsahuje bibliografii
Contamination of Enterocytozoon bieneusi Desportes, Charpentier, Galian, Bernard, Cochand-Priollet, Laverne, Ravisse, et Modigliani, 1985 in water sources may cause outbreaks of microsporidiosis. To examine the occurrence of E. bieneusi, 108 raw wastewater samples were collected from three wastewater treated plants in Zhengzhou, China. In total, 46 samples were PCR positive for E. bieneusi. A total of 15 ITS genotypes was identified, including ten known genotypes (D, BEB6, I, J, PigEbIX, PigEBITS5, EbpA, Peru6, Peru8, Type IV) and five novel genotypes (HNWW1, HNWW2, HNWW3, HNWW4, HNWW5). Nine genotypes belonged to a known zoonotic group (group 1) and the other genotypes belonged to potential zoonotic group (group 2). Most of the genotypes had been identified in wildlife or domestic animals in former reports in Zhengzhou. The occurrence of E. bieneusi in wastewater was probably related to the rainfall day before sampling. Of 36 sampling days, 20 days had rainfall on the previous day and 16 days had none. As many as 43 of 60 samples were found to be E. bieneusi-positive in the 20 days which had rainfall on the previous day. Only three of 48 samples were found to be E. bieneusi-positive in the 16 days without rainfall the day before. The significant difference of the occurrence of E. bieneusi was observed between wet days and dry days by t-test (43/60 vs 3/48, p < 0.01). This indicates that the occurrence of E. bieneusi in wastewater in Zhengzhou mainly originated from animals and was probably related to rainfall the day before sample collection. Given the zoonotic genotypes detected in wastewater, animal faeces should be treated appropriately before being drained into the water source., Jianbin Ye, Ji Yan, Jia Xu, Ke Ma, Xuepeng Yang., and Obsahuje bibliografii
Fyzikálne vzdelávanie v rámci prírodovedného a technického vzdelávania je vo vyspelých krajinách považované za dôležité. Pritiahnuť mladých ľudí a inšpirovať ich učiteľov pri vzdelávaní v týchto školských predmetoch je viacročnou ambíciou aj autorov tohto článku. V tomto článku sa zameriavame na využitie lacnej vývojovej dosky s jednočipovým mikropočítačom Arduino Uno R3 pri konštrukcii jednoduchého hudobného zariadenia - syntetizátora - a jeho následného využitia vo výučbe. Samotná konštrukcia zariadenia môže byť námetom na časovo náročnejšiu bádateľskú aktivitu (v zmysle IBSE - Inquiry Based Science Education). Súčasťou článku sú aj námety na ďalšie bádateľské aktivity, od časovo náročnejšej, venovanej konštrukcii syntetizátora, až po jednoduchšie, zrealizovateľné v rámci jednej vyučovacej hodiny., Physics education is considered to be important in science and technology education in developed countries. Attracting young people and inspiring their teachers for these subjects is a long-term ambition of the authors of this article. In this paper, we focus on using a low-cost development board with a single-chip microcomputer Arduino Uno R3 in the construction of a simple music device - a synthesizer - and its subsequent use in teaching. The design of the device itself can be the subject of a time-consuming inquiry-based activity (in terms of IBSE - Inquiry Based Science Education). This article also includes suggestions for further inquiry-based activities, from the more time-consuming construction of the synthesizer to simpler ones, that can be achieved within one lesson., Martin Hruška, Miriam Spodniaková Pfefferová, Stanislav Holec., and Obsahuje bibliografické odkazy
The Japanese Hossô-monk Jôkei (1155-1213) is one of the better-known contemporaries of the famous Hônen (1133-1212), whose Pure Land School (Jôdo-shû) became so influential in medieval Japanese society. The Tôshôdaiji shaka-nenbutsu ganmon of Jôkei, however, is an interesting example for the often overlooked renaissance of the Japanese Vinaya School (Kairistu-shû) at that time. Being the second in a series of translations of important texts by Jôkei, the present article tries also to discuss this ganmon in the context of Jôkei´s thought.
One of the most abundant immunologic cell types in early decidua is the uterine natural killer (UNK) cell that despite the presence of cytoplasmic granules rich in perforin and granzymes does not degranulate in normal pregnancy. UNK cells are important producers of angiogenic factors that permit normal dilation of uterine arteries to provide increased blood flow for the growing feto-placental unit. Gram-negative bacteria lipopolysaccharide (LPS) administration can trigger an imbalance of pro-inflammatory and anti-inflammatory cytokines impairing the normal immune cells activity as well as uterine homeostasis. The present study aimed to evaluate by immunohistochemistry the reactivity of perforin and α-actin on UNK cell from LPStreated pregnant mice. For the first time, we demonstrate that LPS injection in pregnant mice causes α-actin down regulation, concomitantly with perforin loss in UNK cells. This suggests that LPS alters UNK cell migration and activates cytotoxic granule release., B. Zavan, A. M. do Amarante-Paffaro, V. A. Paffaro Jr., and Obsahuje bibliografii
The concept of α-ideals in posets is introduced. Several properties of α-ideals in 0-distributive posets are studied. Characterization of prime ideals to be α-ideals in 0- distributive posets is obtained in terms of minimality of ideals. Further, it is proved that if a prime ideal I of a 0-distributive poset is non-dense, then I is an α-ideal. Moreover, it is shown that the set of all α-ideals α Id(P) of a poset P with 0 forms a complete lattice. A result analogous to separation theorem for finite 0-distributive posets is obtained with respect to prime α-ideals. Some counterexamples are also given.