Název Centrum pro výzkum věřejného mínění nebo jeho zkratku CVVM zná asi každý. Přinejmenším z televizního zpravodajství týkajícího se stranických preferencí, volebních modelů či předvolebních průzkumů. Málokdo však ví, že jed o pracoviště Sociologického ústavu AV ČR. Ještě překvapivější bude asi zjištění, že v CVVM pracuje pouhých 15 lidí. and Luděk Svoboda.
This study introduces an emblematic scheme within the stucco decoration of the Palace Chapel in Červené Poříčí. The given emblematic sheme glorifies the Most Sacred Heart of Jesus. It was inspired by the emblem book of the Bavarian theologian Anton Ginther, which was published in 1706. The article tries to place the programme of the decoration into the context of Middle European evolution of the devotion to the Most Sacred Heart of Jesus - a cult that was very popular at the time. Finally, the article places the decorative scheme into political and historical context and discusses the role its patron played in determining the decoration’s commission and execution., Daniela Štěrbová., and Obsahuje bibliografické odkazy
Proč se nekříží kočka se psem? Proč se sice může zkřížit kůň s oslem, ale jejich potomci - mulové či mezci - jsou neplodní? Z jakého důvodu jsou někdy strilní i kříženci dvou blízce příbuzných poddruhů, třeba myší, a souvisí to nějak se vznikem nových živočišných druhů? Jeden z nejdůležitějších článků tété záhady odhalil Jiří Forejt z Ústavu molekulární genetiky Akademie věd ČR, kterýá identifikoval první gen u savců zodpovědný za samčí neplodnost mezidruhových kříženců, přečetl ho a ukázal, jak je regulován. and Jana Olivová, Stanislava Kyselová.
Survival and Lt50 after exposures at constant low temperature were compared to the values obtained at alternating temperatures in two active (summer acclimated) temperate terrestrial arthropods. The experimental regimes used interruptions - daily transfers from the lower temperature to various higher temperatures for two hours or to one high temperature for Various durations. In both species the alternating conditions improved survival, implying reparation of the chill injury. In the collembolan Orchesella cincta, there was a maximum Lt50 when the higher exposure temperature was equal to the temperature of rearing (19°C). In the bug Pyrrhocoris apterus, Lt50 increased strongly with increasing higher temperature from 0 to 15°C, and was subsequently constant over the entire physiological range suitable for development (to 35°C). Exposure at 0°C was harmful if continuously applied, but survival increased, relative to a constant exposure at -5°C, if the temperature alternated between -5 and 0°C., Zdeněk Hanč, Oldřich Nedvěd, and Lit
Winter climate determines the success of the two main reproductive strategies employed by aphids. Permanent parthenogens survive as parthenogenetic females in mild winters, but are regularly eliminated by low temperatures; while cyclical parthenogens, which switch to sexual reproduction by the end of summer, produce every year fertilised diapausing eggs resistant to frost.
We have studied the variation in sexual morph production of several clones of the cereal aphid Rhopalosiphum padi (L.) showing both strategies. Twenty clones of this species differing by their geographic origin and their mode of reproduction were placed in two laboratory environments mimicking the changes of photoperiod and thermoperiod occurring naturally from the end of summer and during the autumn in oceanic and continental conditions. The analysis of clonal responses in both climatic conditions showed (i) a wide variation in investment of clones in sexual reproduction with, in particular, evidence for a mixed strategy employed by clones producing both sexuals without ceasing parthenogenetic reproduction, (ii) no geographic adaptation among clones belonging to cyclical parthenogenetic populations, (iii) an earlier production of sexuals in continental conditions and a higher production of males in oceanic conditions.
Furthermore, we have compared the dates of first appearance of sexuals in our experiments with those occurring in the field based on a suction trap database and found that sexuals were caught in nature at least four weeks earlier than in the lab. These results underline the need for a better understanding of the influence of the whole array of environmental factors inducing the transition from parthenogenetic to sexual reproduction in aphids., Maurice Hullé, Damien Maurice, Claude Rispe, Jean-Christophe Simon, and Lit