Search

Start Over Rights http://creativecommons.org/licenses/by-nc-sa/4.0/ Date Unknown

32753. Vegetative growth and photosynthesis in coffee plants under different watering and fertilization managements in Yunnan, SW China

Creator:
Cai, C.-T., Cai, Z.-Q., Yao, T.-Q., and Qi, X.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence kinetics, Coffea arabica, drip irrigation, gas exchange parameters, mulching, photochemical efficiency, relative growth rate, and stomatal conductance
Language:
Multiple languages
Description:
In a field experiment Coffea arabica L. was subjected to various moisture and fertilizer regimes in Simao, Yunan, SW China. The experimental treatments consisted of eight factorial combinations of two fertilization levels (high and low) and four watering treatments applied in the dry season: application of dry rice straw mulch, drip irrigation, mulching plus drip irrigation on the soil surface, and control (no mulching or irrigation). The growth of the coffee plants was monitored throughout the course of a full year. Two clear growth peaks were detected (one at the beginning and one in the middle of the wet season) in plants subjected to all treatments, and the growth rhythm of coffee plants was not regulated by extrinsic abiotic factors. High fertilization resulted in a significantly higher relative growth rates for both height and length of the branches during the growth peaks than the low fertilization treatment. In the dry season, increasing the soil moisture contents by irrigation and/or mulching enhanced the plants' gas exchange, but the soil water status had no significant effects on the internal fluorescence parameters of photosystem 2. More fertilized plants had a greater ability to acclimate to high-irradiance environments than the lightly fertilized plants, showing significant lower diurnal photoinhibition, associated with higher energy utilization through photochemistry and energy dissipation through the xanthophyll cycle. Hence the wet season is the optimum period for photosynthetic carbon fixation and vegetative growth of coffee plants. Higher than routinely applied levels of fertilization are required to optimize the coffee plants' photosynthetic acclimation and growth in the studied environment. Both soil moisture conserving practices tested, mulching and drip irrigation, had significant effects on the growth and photosynthesis of the coffee plants, but the former was more practical than the latter. and C.-T. Cai ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

32754. Vegetative growth, compatible solute accumulation, ion partitioning and chlorophyll fluorescence of ‘Malas-e-Saveh’ and ‘Shishe-Kab’ pomegranates in response to salinity stress

Creator:
Khayyat, M., Tehranifar, A., Davarynejad, G. H., and Sayyari-Zahan, M. H.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, chloridy, fluorescence, chlorid sodný, draslík, sodík, photosynthesis, chlorides, sodium chloride, potassium, sodium, chloride, growth, NaCl, proline, total carbohydrates, 2, and 581
Language:
Multiple languages
Description:
The present research was conducted to assess physiological responses of ‘Malas-e-Saveh’ (Malas) and ‘Shishe-Kab’ (Shishe) pomegranates to water of different salt content and electrical conductivity (1.05, 4.61, and 7.46 dS m-1). Both cultivars showed a reduced trunk length due to salinity. Relative water content and stomatal conductivity of both cultivars were significantly reduced under salt stress, but ion leakage increased. In both cultivars, total chlorophyll (Chl) and carbohydrates decreased with rise in salinity, while proline accumulation increased. With salinity increment, the Chl fluorescence parameters (maximum photochemical efficiency of PSII and effective quantum yield of PSII) declined significantly in both cultivars, with higher reduction observed in Shishe. Generally, more Na+ accumulated in shoots and more Cl- was observed in leaves. Cl- accumulation increased by salinity in leaves of Malas, but it was reduced in Shishe. The K+/Na+ ratio in leaves decreased in both cultivars by salinity increment. Malas was less affected by osmotic effects of NaCl, but it accumulated more Cl- in its leaves. Thus, Malas might be more affected by negative effects of salinity., M. Khayyat, A. Tehranifar, G. H. Davarynejad, M. H. Sayyari-Zahan., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

32757. Věková homogamie českých sňatků 1920-2000

Creator:
Fučík, Petr
Format:
print
Type:
model:internalpart and TEXT
Subject:
sociology of the family, marriage market, assortative mating, age homogamy, and Czech Republic
Language:
Czech
Description:
The article examines the long-term changes and the age homogamy of marriages that took place in the Czech Republic between 1920 and 2000. The analysis of data acquired from a study of vital registration is divided into a descriptive part - describing the age structure of the marriage market and the absolute degree of age homogamy - and an exploratory part - creating a log-linear model of the structure and changes of relative age homogamy. Three hypotheses are formulated in connection with the latter part of the analysis, of which the hypothesis about increasing age homogamy seems acceptable. Results from the descriptive analysis and the models show that age homogamy has been increasing during the 20th century, both in the case of first marriages and remarriages. The hypothesis about the greater degree of age heterogamy in the case of remarriages can also be accepted, while the testing of the third hypothesis, that the older the marital partners are the more heterogamous their age structure, proved inconclusive and requires further investigation.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

32758. Vektorová Kerrova magnetometrie s vysokým prostorovým rozlišením

Creator:
Flajšman, Lukáš, Urbánek, Michal, Křižáková, Viola, Vaňatka, Marek, Turčan, Igor, and Šikola, Tomáš
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
vectorial magnetometry, Kerr effect, MOKE, magnetic vortices, and domain wall
Language:
Czech
Description:
The article reports on the development of a high-resolution scanning Kerr magnetometer which fully exploits the vectorial nature of the magneto-optical Kerr effect. The response of a magnetic micro and nanostructures to the external stimuli is often accompanied with non-trivial magnetizing processes. Correct interpretation of the data obtained from the magneto-optical measurement is often hard to carry out. The magneto-optical signal is generally given by all the components of magnetization vector, thus the task to separate individual components of the magnetization vector is not trivial. Our scanning Kerr magnetometer uses a light beam that has been deterministically deviated from the microscope objective symmetry axis. Using a high-numerical aperture microscope objective we can precisely control the light propagation vector k (hence control the probed components of magnetization), therefore both in-plane (via the longitudinal Kerr effect), and out-of-plane (via the polar Kerr effect) components of the magnetization vector may be detected. These components are then separated by exploiting the symmetries of the polar and longitudinal Kerr effects. From four consecutive measurements we are able to directly obtain the three orthogonal components of the magnetization vector with a resolution < 600 nm. Performance of the apparatus is demonstrated by a characterization of a domain walls in an yttrium-iron-garnet (YIG) film and on a study of magnetization reversal in magnetic disk. and Článek popisuje vývoj skenovacího Kerrova magnetometru s vysokým prostorovým rozlišením. Představené zařízení beze zbytku využívá možností Kerrova jevu pro vektorovou magnetometrii. Odezva magnetických mikro a nanostruktur na vnější podnět je často provázena netriviálními magnetizačními procesy. K pochopení a správné interpretaci experimentálních dat je nutné a zároveň poměrně obtížné získat úplnou informaci o vektoru magnetizace, neboť měřený signál je často kombinací signálů od všech komponent vektoru magnetizace. Námi vyvinutý skenovací Kerrův magnetometr využívá přesně determinovaného mimoosového šíření svazku v mikroskopovém objektivu s vysokou numerickou aperturou k vytvoření téměř libovolného propagačního vektoru světla k (určujícího detekovanou magnetizaci) k měření obou komponent magnetizace ležících v rovině vzorku (s využitím takzvaného longitudinálního Kerrova jevu) a taktéž k měření komponenty magnetizace se směrem kolmým na rovinu vzorku (pomocí polárního Kerrova jevu). Jednotlivé komponenty jsou z naměřených dat získány za pomocí symetrií polárního a longitudinálního Kerrova jevu, jež jsou implicitně dány geometrií experimentu. Pomocí čtyřkrokové procedury jsme schopni určit všechny složky vektoru magnetizace s rozlišením < 600 nm. Zařízení bylo využito k charakterizaci doménové stěny v YIG vzorku a dále při studiu přepínání magnetizace v magnetických discích.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

32759. Velcí mlži a jejich hostitelské vazby

Creator:
Douda, Karel
Format:
print, bez média, and svazek
Type:
article, text, články, journal articles, model:article, and TEXT
Subject:
Biologické vědy, mlži, sladkovodní živočichové, parazit a hostitel, vodní měkkýši, aquatic molluscs, parasite and host, freshwater animals, Bivalvia, glochidia, Unionida, 2, and 57/59
Language:
Czech
Description:
Parazitické stádium velkých mlžů (řád Unionida) vytváří velmi těsné spojení mezi těmito druhy a jejich rybími hostiteli. Tento článek představuje variabilitu mezidruhových interakcí na příkladech středoevropských druhů., The parasitic stage of freshwater mussels (order Unionida) constitutes a tight host-affiliate linkage between mussels and their host fish. This article presents the variability of interactions using the Central European species as a model group., and Karel Douda.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

32760. Velemyš dinagatská - znovuobjevení a nové české jméno domněle vyhynulého hlodavce =

Creator:
Řeháková, Milada and Řehák, Václav
Format:
print
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Zoologie, savci, myšovití, vyhynulé druhy, Filipíny, Philippines, 2, and 59
Language:
Czech
Description:
Velemyši, dříve nazývané krysy obláčkové, jsou největší myšovití hlodavci žijící endemicky na Filipínách. Velemyš dinagatskou (Crateromys australis), považovanou za potenciálně vyhynulou, se nám podařilo znovuobjevit 37 let od jejího posledního (a zároveň prvního) nálezu a vědeckého popisu. To bylo také impulzem k návrhu nového českého jména velemyši pro celou skupinu obláčkových krys. Velemyš dinagatská byla nalezena na severu ostrova Dinagat. Nyní je řazena mezi kriticky ohrožené druhy. Ohrožené jsou také ostatní druhy této skupiny, a to zejména kvůli masivní těžbě dřeva a nerostných surovin a tím ničením jejich přirozeného prostředí. Proto je cílená ochrana je nezbytná k přežití tohoto i ostatních druhů velemyší., Cloud rats are the largest murid rodents endemic to the Philippines. The Dinagat Cloud Rat (Crateromys australis), considered to be potentially extinct, was rediscovered in the north of Dinagat Island after 37 years from its first discovery and scientific description. We have also proposed a new Czech name. The species is now listed as critically endangered. All cloud rats are threatened by the destruction of their natural habitats by logging and mining. Targeted protection is therefore essential for their survival., and Milada Řeháková, Václav Řehák.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

Limit your search

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »