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4542. Chain correlation between variables of gas exchange and yield potential in different winter wheat cultivars
- Creator:
- Jiang, G. M., Hao, N. B., Bai, K. Z., Zhang, Q. D., Sun, J. Z., Guo, R. J., Ge, Q. Y., and Kuang, T. Y.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- apparent quantum yield of CO2 fixation, compensation irradiance, cultivars with high and low yield potentials, dark respiration, flag leaf, net photosynthetic rate, stomatal conductance, transpiration, and water use efficiency
- Language:
- Multiple languages
- Description:
- Variables of gas exchange of flag leaves and grain yield potentials of five representative winter wheat (Triticum aestivum L.) cultivars varied greatly across different development stages under the same management and irrigation. The cultivars with high yield potential had higher net photosynthetic rate (PN), PPFD (photosynthetic photon flux density) saturated photosynthetic rate (Psat), stomatal conductance (gs), and maximum apparent quantum yield of CO2 fixation (Φm,app) than those with low grain yield, but their dark respiration rate (RD) and compensation irradiance (Ic) were remarkably lower. Compared with overall increase of yield potential of 71 % from low yield cultivars to high yield ones, PN, Psat, Φm,app, and gs were 13, 19, 57, and 32 % higher, respectively; but RD and Ic decreased by 19 and 76 %, respectively. Such difference was evidently large during anthesis stage (e.g., PN by 33 %), which indicated that this period could be the best for assisting further selection for better cultivars. However, transpiration rate (E) and water use efficiency (WUE) differed only little. At different development stages, especially at anthesis, PN and Psat were positively correlated with Φm,app, gs, and yield potential, and negatively correlated with RD and Ic. Thus the high-yield-potential winter wheat cultivars possess many better characters in photosynthesis and associated parameters than the low-yield cultivars. and G. M. Jiang ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4543. Chalíl Džibrán: Písek a pěna
- Creator:
- Pantůček, Svetozár
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4544. Challenges and problems of neuroeconomics: several tasks for social scientists
- Creator:
- Müller, Michal
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- decision-making, methodology, neuroeconomics, philosophy of economics, philosophy of science, filosofie ekonomie, filosofie vědy, metodologie, neuroekonomie, and rozhodování
- Language:
- Czech
- Description:
- Neuroscience is a fascinating discipline – its dynamic progress has led to the emergence of new interdisciplinary research programmes with great potential. One of these research areas is neuroeconomics. As will be shown in this article, this discipline, which is diffi cult to clearly characterize and defi ne, is faced with many problems. Th is paper argues that social scientists should be interested in the problems and tendencies in social neuroscience for several reasons. Neuroeconomics, and other disciplines inspired by neuroscience, will compete with their parent disciplines in many fi elds of interest. On one hand it will be necessary for scientists to defi ne and defend the irreplaceable roles of their disciplines, but also critically evaluate the potential of new approaches on the other. In the context of this discussion, which reopens questions about the scientifi c status of economics and its roles, this paper introduces the main problems related to neuroeconomics. Th is paper concludes that these problems represent a wide domain for social scientists and methodologists of science. and Neurověda je fascinující disciplínou – její dynamický rozvoj podněcuje vznik nových interdisciplinárních výzkumných programů s velkým potenciálem. Jednou takovou oblastí je i neuroekonomie. Jak se ukáže v článku, tato disciplína, kterou je obtížné jednoznačně vymezit a určit její defi nici, se potýká se spoustou problémů. Článek y jj fi argumentuje, že by se společenští vědci měli těmito problémy a tendencemi v sociální neurovědě zabývat, a to hned z několika důvodů. Neuroekonomie, a také další neurovědou inspirované disciplíny, budou svým mateřským oborům konkurovat v mnoha oblastech, přičemž bude nezbytné, aby vědci byli schopni na jedné straně defi novat a obhájit nezastupitelné role svých disciplín, na straně druhé kriticky vyhodnocovat potenciál nových přístupů. V kontextu této diskuze, která znovu otevírá otázky ohledně vědeckého statusu ekonomie a jejích rolí, článek vymezuje základní problémy, s nimiž se neuroekonomie potýká. Práce dospívá k závěru, že tyto problémy představují široké pole působnosti pro společenské vědce a metodology vědy.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4545. Challenges to the theories of B stars circumstellar environment
- Creator:
- Krtička, J., Korčáková, D., and Kubát, J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- stars: winds, stars: outflows, stars: mass-loss, stars: early-type, hydrodynamics, and instabilities
- Language:
- Czech
- Description:
- We review recent developments in the field of B stars circumstellar environment modelling and discuss future improvements which are necessary to obtain more realistic models of the circumstellar environment of B stars.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4546. Chamber response time: A neglected issue in gas exchange measurements
- Creator:
- Weiss, I., Mizrahi, Y., and Raveh, E.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chamber steady state, Hylocereus, infrared gas analyser, laboratory-made chambers, net CO2 uptake, open system, and self-clamping chambers
- Language:
- Multiple languages
- Description:
- When the dimensions of standard commercial chambers for measuring gas exchange cannot accommodate the object being measured, scientists construct their own chambers. The time needed to reach chamber steady state (chamber response time) depends on net system volume (e.g. chamber and tubing volume) and airflow. Unfortunately, some authors take chamber response time into consideration while others ignore it. We present the formula for calculating chamber response time. and I. Weiss, Y. Mizrahi, E. Raveh.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4547. Chamber series and space-scale analysis of CO2 gas-exchange in grassland vegetation: A novel approach
- Creator:
- Czóbel, Sz., Fóti , Sz., Balogh, J., Nagy, Z., Bartha, S., and Tuba, Z.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- canopy chamber, grassland, loess, sand, and stand CO2 measurements
- Language:
- Multiple languages
- Description:
- Significant part of our work was developing a new type of CO2 and H2O gas exchange chambers fit for measuring stand patches. Ground areas of six chambers (ranged between 0.044-4.531 m2) constituted a logarithmic series with doubling diameters from 7.5 to 240.0 cm. We demonstrate one of the first results for stand net ecosystem CO2 exchange (NEE) rates and temporal variability for two characteristic Central European grassland types: loess and sand. The measured mean NEE rates and their ranges in these grasslands were similar to values reported in other studies on temperate grasslands. We also dealt with the spatial scale dependence from ecophysiological point of view. Our chamber-series measurement was performed in a perennial ruderal weed association. The variability of CO2-assimilation of this weed vegetation showed clear spatial scale-dependence. We found the lowest variability of the vegetation photosynthesis at the small-middle scales. The results of spatial variability suggest the 0.2832 m2 patch size is the characteristic unit of the investigated weed association and there is a kind of synphysiological minimi-area with characteristic size for each vegetation type. and Sz. Czóbel ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4548. Chamber with controlled atmosphere for the project AIRFLY
- Creator:
- Vacek, Václav, Doubrava, Michal, Nožka, Libor, Hrabovský, Miroslav, Řídký, Jan, Schovánek, Petr, Palatka, Miroslav, Boháčová, Martina, Pech, Miroslav, and Mandát, Dušan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Czech
- Description:
- The aim of the AIRFLY (air fluorescence yield) project is to simulate and to measure the process of the fluorescence and Cherenkov emission produced by impact of cosmic rays on molecules of nitrogen in high level atmosphere. Several setups were designed to measure fluorescent and Cherenkov light. In this paper we report the chamber with controlled atmosphere to simulate conditions in various levels of the Earth atmosphere. The chamber was designed in the Institute of Physics of Academy of Sciences of the Czech Republic in cooperation with the Faculty of Mechanical Engineering, Czech Technical University and the Joint Laboratory of Optics of Palacky University and Institute of Physics of Academy of Sciences in Olomouc. and Cílem projektu AIRFLY je napodobit a proměřit proces fluorescenční a Čerenkovské emise vznikající dopadem kosmického záření na molekuly dusíku ve vyšších vrstvách atmosféry. Bylo navrženo několik uspořádání pro měření fluorescenčního a Čerenkovského světla. V tomto článku je popsána komora s řízenou atmosférou pro modelování podmínek v různých výškách zemské atmosféry. Komora byla zkonstruována ve Fyzikálním ústavu AV ČR ve spolupráci se Strojní fakultou ČVUT a Společnou laboratoří optiky Univerzity Palackého a FZÚ AV ČR v Olomouci.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4549. Chamois introductions to Central Europe and New Zealand
- Creator:
- Martínková, Natália, Zemanová, Barbora, Kranz, Andreas, Giménez, Mabel D., and Hájková, Petra
- Type:
- article, model:article, and TEXT
- Subject:
- Alpine chamois, animal translocations, introduction, invasive species, and Rupicapra rupicapra
- Language:
- English
- Description:
- Chamois (Rupicapra rupicapra) introductions were popular at the beginning of the 20th century when first animals were shipped from Austria to the Czech Republic and New Zealand. The historical record of the Czech introduction indicates Neuberg Mürzsteg Game Reserve in Eastern Alps, Styria, Austria as the main area of origin of founders. First animals for the New Zealand population are thought to have originated from Ebensee, Upper Austria, Austria and later more animals came from the Mürzsteg region. We sequenced mitochondrial control region of chamois from the introduced populations and their putative source areas, and we applied median-joining networks and Bayesian inference analysis to distinguish the regions of origin of female founders. We found the Mürzsteg region as the most likely source population for introductions to the Czech Republic and New Zealand, supplemented with close association with sequences from Ebensee in populations from the Czech Republic. Genetic diversity present in the Czech Republic was further relocated to the introduced populations in Slovakia in the 1960’s.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4550. Chandrasekhar: 19-10-1910
- Creator:
- Bičák, Jiří
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- Chandrasekhar, S. (Subrahmanyan), 1910-1995, fyzici, physicists, Indie, India, 53-051, (540), 6, and 53
- Language:
- Czech
- Description:
- Jednou, krátce před půlnocí, tížen příslibem redakci Československého časopisu pro fyziku, nechávám běžné práce, otevřu Word a po nadpisu mě napadne podívat se do kalendáře: opravdu, za chvíli začíná 19. říjen 2010. Právě před 100 lety, 19-10-1910 (tak sám rád psal), se narodil Subrahmanyan Chandrasekhar, velká postava vědy 20. století, jeden z nejuniverzálnějších astrofyziků, nositel Nobelovy ceny za fyzku v roce 1983, ve vědeckých kruzích známý jako Chandra. O fyzikálním a astronomickém významu jeho Nobelovy ceny, kterou získal společně s W. A. Fowlerem, jsem již v tomto časopisu psal [1]. V následujícím se chci více zaměřit na události a postavy v okolí jeho světočáry; přitom čerpám především z podrobné biografie [2]. Na závěr připojím několik osobních vzpomínek na interakci s ním, nebudu však již opakovat ty, které jsou uvedeny v článku psaném před 27 lety., Jiří Bičák., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public