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3. Black leaf-clips increased minimum fluorescence emission in clipped leaves exposed to high solar radiation during dark adaptation

Creator:
Giorio, P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, leaf-clip effect, pepper, photochemical efficiency, radiation, temperature, and tomato
Language:
Multiple languages
Description:
Tomato and pepper leaves were clipped with black leaf clips for dark adaptation under solar radiation in the late spring or early summer 2010 in southern Italy. The leaves showed highly variable maximum PSII quantum yield (Fv/Fm = 0.026-0.802) using a continuous-excitation fluorometer Pocket PEA. These results were confirmed using the modulated fluorometer FMS1 on tomato leaves in mid summer, with Fv/Fm as low as 0.222 ± 0.277 due to nearly equal minimum (F0) and maximum (Fm) fluorescence emission. A significant clip effect on Fv/Fm occurred after only 12 (tomato) or 25 (pepper) min. Increasing the leaf temperature from 25 to 50°C reportedly induced an F0 increase and Fm decrease so that Fv/Fm approached zero. The hypothesis that black leaf clips overheated under intense solar irradiance was verified by shrouding the clipped leaves with aluminum foil. In clipped leaves of pepper, Fv/Fm with the black clip/Pocket-PEA was 0.769 ± 0.025 (shrouded) and as low as 0.271 ± 0.163 (nonshrouded), the latter showing a double F0 and 32% lower Fm. An 8% clip effect on Fv/Fm was observed with the white clip/FMS1. To avoid the clip effect in high irradiance environments, Fv/Fm measurements with black clip/Pocket PEA system required leaf dark adaptation with radiation-reflecting shrouds. It would be useful if manufacturing companies could develop better radiation-reflecting leaf clips for the Pocket PEA fluorometer. and P. Giorio.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. George F. Smoot: životopis

Creator:
Smoot, George F. and Gregora, Ivan
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
Smoot, George, 1945-, 20.-21. století, fyzici, záření, ceny a vyznamenání, Nobelova cena (ocenění), physicists, radiation, awards, Nobel Prizes, Spojené státy americké, United States, 6, and 53
Language:
Czech and English
Description:
Získat Nobelovu cenu je událost, která změní život. Bod zlomu. Mnoho lidí chce vědět, jak toho laureát dosáhl, a také se po něm žádá, aby dodal svůj životopis. To všechno a události provázející udělení Nobelovy ceny způsobí, že se každý z nás zamyslí nad svým životem, zavzpomíná a pokusí se vystihnout všechny události, které ho dovedly až do přítomnosti., George F. Smoot ; přeložil Ivan Gregora., and přeloženo z angličtiny
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Od Lemaîtra k reliktnímu záření a Jamesi Peeblesovi

Creator:
Chýla, Jiří
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fyzikální kosmologie, záření, physical cosmology, radiation, 6, and 53
Language:
Czech
Description:
Half of this year‘s Nobel Prize in Physics was awarded to American cosmologist James Peebles "for theoretical discoveries in physical cosmology". In this article we describe the emergence of the BigBang model of the Universe, recall the people who made decisive contributions to its formulation, emphasize the crucial importance of the discovery of Cosmic Microwave Background radiation, and outline the contribution James Peebles made for the understanding of our Universe. and Jiří Chýla.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Physiological responses of Pterocladiella capillacea (Rhodophyta, Gelidiales) under two light intensities

Creator:
Harb, T. B., Nardelli, A., and Chow, F.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
řasy, pigmenty, produktivita, záření, Algae, pigments, productivity, radiation, chlorophyll fluorescence, growth rate, 2, and 581
Language:
Multiple languages
Description:
Macroalgae must be able to survive in conditions of different light intensities with no damage to their physiological performance or vital processes. Irradiance can stimulate the biosynthesis of certain photoprotective compounds of biotechnological interest, such as pigments and proteins. Pterocladiella capillacea is a shade-grown alga, which play a role key in the balance of marine ecosystems. In addition, it is considered one of the best sources of bacteriological agar and agarose with a wide pharmacological potential. In order to evaluate the photosensitivity in P. capillacea under 60 (control) and moderate light intensity of 300 μmol(photon) m-2 s-1, photosynthetic performance and chemical composition were assessed. P. capillacea showed photosensitivity without evidence of photodamage. The results indicate the possibility to increase a growth rate and probably infer productivity in long-term cultivation by stimulation at moderate light intensity. Increasing photosynthetic pigment and protein contents were also observed under medium light, an interesting result for functional ingredient approaches., T. B. Harb, A. Nardelli, F. Chow., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7. Vilém Santholzer: vědec a avantgardista mezi krásou stroje a záření

Creator:
Vítů, Viktorie
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Vilém Santholzer, radiation, art, and photo
Language:
Czech
Description:
Vilém Santholzer byl český radiolog, který v druhé polovině dvacátých let na stránkách avantgardních periodik publikoval ke třem desítkám článků a několik vlastních fotografií radiového záření. Článek sleduje tuto jeho aktivitu a zasazuje ji do kontextu zájmu evropské avantgardy o strojovou estetiku na jedné straně a vědeckou fotografii na straně druhé. Ukazuje, že pro Santholzera je krása vždy přímým důsledek jiných vlastností objektu spojených s pravdou: stroje jsou podle něho krásné, jsou-li účelné, fotografie, jsou-li autentické. Zatímco jeho úvahy věnované strojové estetice můžeme dát do souvislostí s myšlenkami ruského konstruktivismu, Le Corbusiera, Karla Teiga či Wernera Graeffa, v případě jeho fotografií lze hledat paralely u autorů tematizujících možnosti fotografie zviditelnit neviditelné, tedy především u László Mohly-Nagye a opět u Karla Teiga. Zvláštním rysem Santholzerova myšlení pak zůstává jeho přesvědčení o kráse čisté, neaplikované matematiky, které je představeno prostřednictvím Santholzerovy polemiky s Karlem Honzíkem na stránkách Pásma. and Vilém Santholzer was a Czech radiologist who in the second half of the 1920s published around thirty articles and several of his own photographs of radiation on the pages of avant-garde journals. The article explores his activities and situates them in the context of the interest of the European avant-garde in the machine aesthetic on the one hand and scientific photography on the other. It shows that for Santholzer beauty was always the direct result of other properties of an object associated with truth; in his view, machines were something beautiful if they were functional, and photographs were beautiful if they were authentic. While we can connect his thought on the machine aesthetic with the ideas of Russian constructivism, Le Corbusier, Karel Teige or Werner Graeff, in the case of his photographs we can find parallels among authors interested in the power of photography to make the invisible visible, i.e. above in the work of László Moholy-Nagy and once again Karel Teige. What then remains a peculiar feature of Santholzer’s thought is his belief in the beauty of pure, unapplied mathematics, which he set out in his polemics with Karel Honzík on the pages of Pásmo.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. Výsledky a trendy ve výzkumu scintilačních materiálů

Creator:
Nikl, Martin
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
energetické zdroje, záření, scintilace, power resources, radiation, scintillation, 6, and 53
Language:
Czech
Description:
Využití energetických zdrojů záření, především rentgenových (rtg.) a gama paprsků, případně částic (urychlené elektrony, protony, alfa částice, neutrony), ve vědeckých, průmyslových, lékařských a dalších aplikacích v posledních desetiletích výrazně narůstá, a proto probíhá intenzivní výzkum scintilačních materiálů, které tvoří nezbytnou součást jejich detektorů., Martin Nikl., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public