Recently we derived a new star catalog EOC-4 that contains not only the mean positions and linear proper motions, but also periodic changes, due to orbital motions, for double and multiple star systems. The catalog contains 4418 stars that were observed in programs monitoring Earth orientation by optical astrometry during the 20th century. 599 stars of the catalog have significant periodic components. This catalog is now used, as a basic celestial frame, to obtain the Earth orientation parameters from optical astrometric observations of latitude/universal time/altitude in the interval 1899.7-1992.0. Polar motion is determined in 5-day steps for the whole interval studied, Universal time covers the interval 1956.0-1992.0 (i.e., after the invention of atomic clocks) also in 5-day steps, and celestial pole offsets (with respect to recent IAU2000 and IAU2006 models of nutation and precession) are modeled by second-order polynomials of time. In addition to these, a combination of Love and Shida numbers for each observing site is computed., Jan Vondrák, Cyril Ron and Vojtěch Štefka., and Obsahuje bibliografii
The European Academies Science Advisory Council was formed by the national science academies of EU Member States to enable them to collaborate with each other in providing advice to European policy-makers. It thus offers the means for the collective voice of European science to be heard. The EASAC covers all scientific and technical disciplines, and its experts are drawn from all coutries of the European Union. The most recent EASAC meeting was held in June 2008 in Prague. and Luděk Svoboda, Gabriela Adámková.
The study attempts to identify two finds of East Islamic pottery from the Middle Ages in the Czech Lands. It is highly likely that both pieces are standard early stonepaste wares of Syrian provenance whose occurrence in the Czech Lands can be linked to a period with increased contact between Central Europe and Palestine in the 12th – 1st half of 13th century. Unlike Syrian glass and its imitations, Levant pottery did not become goods with powerful, socially distinct or self-identifying symbolism; to the contrary, the role of isolated pottery imports remained limited to the sphere of “social memory”. and Studie se pokouší o identifikaci dvou dosavadních nálezů předovýchodní keramiky ve středověkých českých zemích. V obou případech se s velkou pravděpodobností jedná o standardní fajánse syrské, resp. předovýchodní provenience, jejichž výskyt v Čechách lze zřejmě spojit s obdobím zvýšeného kontaktu mezi střední Evropou a Palestinou ve 12. až 1. pol. 13. století. Na rozdíl od syrského skla a jeho napodobenin se levantská keramika nestala zbožím se silnou sociálně distinktivní či sebeidentifikační symbolikou; role izolovaných keramických importů zřejmě zůstala omezena na sféru tzv. sociální paměti.
A new genus and species of Hemiptera: Heteroptera: Enicocephalomorpha: Aenictopecheidae: Aenictopecheinae, Ulugurocoris grebennikovi gen. et sp. n., based on micropterous females from Tanzania, Uluguru Mts, Budunki, is described and differentiated. The males are probably macropterous. Some general aspects of morphology of U. grebennikovi are discussed in a broader context, such as presence of cephalic trichobothria (suggested to be a groundplan character of Heteroptera), presence of “gular sulci” (suggested to have an ecdysial function), lack of cephalic neck (symplesiomorphy with other Hemiptera), presence of posterior lobe of pronotum associated with the epimeroid (a new term for so called “proepimeral lobe”), and presence of notopleural sulcus on the propleuron. Diagnostic characters of the Aenictopecheinae are summarized and distribution of their seven genera is reviewed. Ulugurocoris grebennikovi is the first representative of the basal family Aenictopecheidae in the Afrotropical Region. The type locality is situated in the Eastern Arc Mountains (Tanzania), a recently identified hotspot of Afrotropical diversity characterized by a high degree of endemism caused by high rates of speciation combined with low rates of extinction. A brief characterization of the area is provided., Pavel Štys, Petr Baňař., and Obsahuje seznam literatury
Commercial chambers for in vivo gas exchange are usually designed to measure on vascular plants, but not on cryptogams and other organisms forming biological soil crusts (BSCs). We have therefore designed two versions of a chamber with different volumes for determining CO2 exchange with a portable photosynthesis system, for three main purposes: (1) to measure in situ CO2 exchange on soils covered by BSCs with minimal physical and microenvironmental disturbance; (2) to acquire CO2-exchange measurements comparable with the most widely employed systems and methodologies; and (3) to monitor CO2 exchange over time. Different configurations were tested in the two versions of the chamber and fluxes were compared to those measured by four reference commercial chambers: three attached to two respirometers, and a conifer chamber attached to a portable photosynthesis system. Most comparisons were done on biologically crusted soil samples. When using devices in a closed system, fluxes were higher and the relationships to the reference chambers were weaker. Nevertheless, high correlations between our chamber operating in open system and measurements of commercial respiration and photosynthetic chambers were found in all cases (R2 > 0.9), indicating the suitability of the chamber designed for in situ measurements of CO2 gas exchange on BSCs., M. Ladrón De Guevara, R. Lázaro, J. L. Quero, S. Chamizo, F. Domingo., and Obsahuje bibliografii
Reduced physical activity and abundant energy intake are two most common factors leading to uncontrolled body weight gain. But these factors are not under entire internal consciousness control; they are also partially genetically determined and are affected by for example food marketing practices. In addition to these two widely accepted factors, there are some other factors, whose could also contribute to the recent increase of obesity prevalence. For example, non-exercise activity thermogenesis, sleeping habits, more stable inside room temperatures (using of heating and air conditioning), high prescription of medications with weight gain as side effect, psychosocial factors, unfavourable socioeconomic status and unpleasant urban environment are the background factors which should not be omitted if obesity/BMI determination should be fully understood and kept under control. In conclusion, unhealthy life style is necessary, but not sufficient for obesity development., J. A. Hubáček., and Obsahuje seznam literatury