The effect of photoperiod on nymphal development in the cricket Modicogryllus siamensis was studied. In constant long-days with 16 hr light at 25°C, nymphs matured within 40 days undergoing 7 moults, while in constant short-days with 12 hr light, 12~23 weeks and 11 or more moults were necessary for nymphal development. When nymphs were transferred from long to short day conditions in the 2nd instar, both the number of nymphal instars and the nymphal duration increased. However, only the nymphal duration increased when transferred to short day conditions in the 3rd instar or later. When the reciprocal transfer was made, the accelerating effect of long-days was less pronounced. The earlier the transfer was made, the fewer the nymphal instars and the shorter the nymphal duration. The decelerating effect of short-days or accelerating effect of long-days on nymphal development varied depending on instar. These results suggest that the photoperiod differentially controls the number of nymphal instars and the duration of each instar, and that the stage most important for the photoperiodic response is the 2nd instar.
Lichen thalli were exposed to 4 regimes differing in irradiance and duration of irradiation. Photosynthetic efficiency of thalli was monitored by chlorophyll fluorescence parameters and xanthophyll cycle analysis. Maximal quantum yield of photosystem 2 (FV/FM) decreased gradually with time in long-term treatment. The effect of additional short-term high irradiance (HI) treatment applied each 24 h was not significant. Nevertheless, short-term HI applied repeatedly on thalli kept in the dark led to a significant decrease of FV/FM. Non-photochemical quenching recorded during the long-term treatment corresponded to the content of zeaxanthin (Z). In short-term treatment, however, proportion of Z (and antheraxanthin) to total amount of xanthophyll cycle pigments recovered to the initial values every 24 h after each repeated short-term HI event in thalli kept in dark. Thus duration of irradiation rather than irradiance and frequency of HI events is important for a decrease in primary photosynthetic processes in wet thalli of Lasallia pustulata. Rapidly responding photoprotective mechanisms, such as conversion of xanthophyll cycle pigments, are involved mainly in short-term irradiation events, even at HI. and M. Barták ... [et al.].
Text se zaměřuje na při jetí a vnímání darwinismu v českých zemích v 19. století, kdy bylo šíření a interpretace Darwinova učení paradoxně spjato s dvěma profesory estetiky z Karlo-Ferdinandovy un verzity v Praze, Josefem Durdíkem a Otakarem Hostinským. Ačkoliv poněkud zjednodušovali teorii přírodního výběru, Darwinovu teorii chápali jako příchod nového paradigmatu (na rozdíl od tehdejších biologů působících v Čechách). Tento text představuje a srovnává interpretaci darwinismu u obou estetiků, zejména jejich stanoviska k teorii přírodního výběru, možnostem aplikace této teorie v estetice a teorii umění, a také jejich vztah k Darwinově
výkladu estetických jevů v přírodě. Jako dodatek následuje krátké vyzdvižení Darwinova učení v textech dalších českých estetiků (Tyrš, Klácel, Volek)., The text is focused on the acceptance and perception of
Darwinism in 19th-century Bohemia, when the diffusion and interpretation of Darwin’s teachings were paradoxical connected with two professors of aesthetics from Charles-Ferdinand University in Prague, Josef Durdík and Otakar Hostinský. Although they somewhat simplified the theory of natural selection, they understood Darwin’s theory to be the arrival of a new paradigm (in contrast to contemporary biologists working in the Czech lands). This text presents and compares both aestheticians’ interpretations of Darwinism, mainly their stance on the theory of natural selection, the possibilities for applying this theory to aesthetics and art theory, as well as their relationship to Darwin’s interpretation of aesthetic phenomena in nature. As a supplement, a short emphasis on Darwin’s teaching in texts of other Czech aesteticians (Tyrš, Klácel, Vol ek) follows., and Karel Stibral.
Based especially on The Elementary Forms of Religious Life (1912) the text tries to delimitate contours of „Durkheim’s epistemology“ (i. e. relatively coherent group of assertions). It argues that the deep „objective“ of this connection is to ensure autonomy and specific field for the new-born scientific province, sociology, through the claim that this contribution can solve and actually does solve (from the French sociologist’s point of view) „traditional epistemological hardships“ into which philosophical empiricism and rationalism fall. Durkheim’s sociological deduction of categories (instead of transcendental deduction), as Ernst Cassirer calls it, is presented in contrast to the „holy positivists interpretations“ of his writing, exclusively intentional conceptualizations of action and notion formation, and correspondence theory of truth. The text concludes that despite noticeable inconsistencies Durkheim’s suggestions provide inspiring material even for today’s sociological production in this field., Jiří Chvátal., Následující text vychází z bakalářské práce Durkheim a pragmatismus: dva přístupy k otázce srozumitelnosti sociálního světa, když přebírá mnohé její pasáže., and Obsahuje bibliografii