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31442. The influence of angiotensin II on sex-dependent proliferation of aortic VSMC isolated from SHR
- Creator:
- Loukotová, J., Bačáková, L., Zicha, J., and Kuneš, J.
- Type:
- article, model:article, and TEXT
- Subject:
- spontaneously hypertensive rat, gender, tissue culture, aortic smooth muscle cells, and angiotensin II
- Language:
- English
- Description:
- The growth response to angiotensin II (Ang II) was studied using cultured vascular smooth muscle cells (VSMC) isolated from the aortae of male and female spontaneously hypertensive rats (SHR). Systolic and mean arterial blood pressure of 10-week-old males was significantly higher when compared to age-matched females. The specific growth rate of male VSMC was significantly higher on the third and sixth day after synchronisation. Angiotensin II in concentration 10~7 M stimulated the specific growth rate only in male VSMC during the exponential phase of growth. Moreover, doubling time was 3 hours shorter in male VSMC in comparison with the females. Our results suggest that both the increased specific growth rate and augmented growth-response of male VSMC to Ang II may explain the higher sensitivity of males to hypertensive stimuli.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31443. The influence of antimycin A on pigment composition and functional activity of photosynthetic apparatus in Triticum aestivum L. under high temperature
- Creator:
- Batjuka, A., Škute, N., and Petjukevičs, A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- alternativní cesta dýchání, chlorofyl a fluorescence, obsah pigmentu, pšenice setá, alternative respiratory pathway, chlorophyll a fluorescence, pigment content, 2, and 581
- Language:
- Multiple languages
- Description:
- The purpose of the current investigation was to evaluate the influence of antimycin A (AA) as an activator of the alternative respiratory pathway (AP) on photosynthetic pigment composition and functional activity of the photosynthetic apparatus of wheat seedlings (Triticum aestivum L.) under exposure to high temperature as well as their acclimation. Our results indicated that a significant decrease (44-74%) of photosynthetic pigment contents was caused by a long-term exposure to high temperature (42°C), while the short-term exposure resulted in 20-46% decline. However, a combined effect of AA and long-term high temperature reduced the total pigment contents by 28-41%. Our results demonstrated that the reduction of the chlorophyll a/b ratio was less significant under the combined effect of AA and high temperature than that under the stressful condition without AA. We observed that short-term and long-term high temperature modified PSII functionality of the first leaves in wheat seedlings, which was manifested by the low maximal quantum yield of PSII photochemistry, maximum fluorescence yield in the dark-adapted state, and by high minimum fluorescence yield in the dark-adapted state. The quantum yield of PSII photochemistry decreased rapidly by 16-24% under the combination of AA and high temperature. Overall, these results suggest that the activation of the alternative pathway, induced by AA, contributed to the stabilization of the photosynthetic apparatus in wheat seedlings under high temperature., A. Batjuka, N. Škute, A. Petjukevičs., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31444. The influence of ascorbic acid on the hepatic cytochrome P-450, and glutathione in guinea-pigs exposed to 2,4-dichlorophenol
- Creator:
- Nagyová, A. and Ginter, E.
- Type:
- article, model:article, and TEXT
- Subject:
- cytochrome P-450, ascorbic acid, glutathione, guinea-pig liver, and 2,4-dichlorophenol
- Language:
- English
- Description:
- Chlorophenols, mainly used as biocides, are compounds with a wide spectrum of toxic effects including teratogenic and carcinogenic actions. In this study, the effects of 2,4-dichlorophenol (2,4-DCP) on hepatic microsomal cytochrome P-450, NADPH-cytochrome c reductase activity, liver ascorbic acid (AA) and glutathione (GSH) content were studied in guinea-pigs with a low (2 mg/day/animal) or a high (50 mg/day/animal) ascorbic acid intake. The high AA intake significantly increased liver AA and GSH levels. There was a clear-cut correlation between liver AA and GSH levels. Administration of 2,4-DCP significantly decreased cytochrome P-450 and f iADPH-cytochrome c reductase activity in hepatic microsomes isolated from guinea-pigs with the low AA intake. Such a reduction was not observed in intoxicated guinea-pigs with the high AA intake. The results suggest that AA can play a protective role in 2,4-DCP toxicity.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31445. The influence of Bernoulli's effect on the function of the vocal cords
- Creator:
- Hrůza, Václav
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- vocal cords, Bernoulli's effect, fluid-structure interaction, suction, and frequency
- Language:
- English
- Description:
- This research is a follow-up to the previous research which was dealing with the creation of the simulation of the vocal cords function using FEM. This paper focuses on how the vocal cords function is affected by Bernoulli's effect, while using model [1] is used. It is well known, that Bernoulli's effect is connected with the suction in the air space between the vocal cords. This is caused by the high air flow in glottis. The fastest and easiest way how to eliminate the influence of this effect is the change of every negative air pressure on the vocal cords to zero (i.e. the pressure applied as the loads on the vocal cords). Authors of some vocal cords models presume that Bernoulli's effect is the main force causing vocal cords vibrations. Changing the negative pressures to zero should cause that the vocal cords would not vibrate. However, the results of this research show the opposite. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31446. The influence of continental water storage on gravity rates estimates: case study using absolute gravity measurements from area of Lower Silesia, Poland
- Creator:
- Rajner, Marcin, Olszak, Tomasz, Rogowski, Jerzy, and Walo, Janusz
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, gravitace, hydrologie, gravity, hydrology, Dolní Slezsko, absolute gravity, FG5 instrument, hydrology loading, 7, and 551
- Language:
- English
- Description:
- In order to utilize the absolute gravity ( AG) measurements in terms of tectonic study it is necessary to reduce all disturbing environmental and instrumental effects. Many of those can be easily modelled and this step is done routinely during measurements (i.e. tide, polar motion, ocean tidal loading). Other remains in data and there is a lack of conventional models for them. Significant gravity variation is associated with changes of soil water at global scale. We study this effect for the Lower Silesia (South-western Poland) territory. Computed gravity changes can reach up to 2 μgal peak-to-peak amplitude with seasonal time scale. This effect is beyond of accuracy of modern ballistic gravimeter. Using real data collected with FG5 gravimeter we show here that neglecting of this phenomenon can lead to serious misinterpretation in term of secular gravity changes. This is emphasized especially when only sparse data of a few year time span is at our disposal. No attempt of modelling of local hydrology impact on effect was made, while in this study we concentrate on large scale water storage influence on measured gravity., Marcin Rajner, Tomasz Olszak, Jerzy Rogowski and Janusz Walo., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31447. The influence of controlled bushing movement on behaviour of a rotor in sliding bearings
- Creator:
- Tůma, Jiří, Šimek, Jiří, Škuta, Jaromír, and Klečka, Radim
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- test stand, hydrodynamic journal bearings, rigid rotor, controlled bushing movement, piezoactuator, relative sensor, oil whirl instability, and elastic support
- Language:
- English
- Description:
- Test stand for investigation of the influence of bearing bushing movement control on behaviour of a rigid rotor supported in sliding journal bearings was designed. The stand was equipped with two pairs of piezoactuators, enabling to move each bearing bushing in two directions, and with two pairs of relative sensors tracing shaft movement at both bearings. The initial tests showed quite unexpected phenomena, which should be cleared up, before experiments with controlled bearing bushing movement could be started. Finally the system began to operate according to predictions and it was possible to start intended experiments. Some results of the rotor behaviour with and without piezoactuator action are presented.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31448. The influence of current on the height of wind wave run-up: a comparison of experimental results with the Czech National Standard
- Creator:
- Říha, Jaromír and Špano, Miroslav
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- levee, dike, wind wave, wave height, wave run-up, current, freeboard design, ochranná hráz, hrázka, větrová vlna, výška vlny, výběh vlny, proudění, and návrh převýšení
- Language:
- Slovak
- Description:
- One of the basic questions related to the safety of dikes and river levees is the size of the freeboard. One of the important parameters for freeboard design is the height of waves and wave run-up on levee slopes. Routine and standardised calculations of wave run-up deal with the freeboards of dams where wind waves originate on the still water of the reservoir. In the case of running water in streams (thereinafter only ''currents'') the effect of wave and current interaction on wave run-up is usually not taken into account due to the lack of reliable knowledge regarding the phenomenon. In the Czech Republic this question is topical in the case of large rivers such as the Elbe, the Vltava and the Morava. Within the framework of the projects Hydralab III and NAZV QI 92A139, hydraulic research and further analysis focused on wave run-up as a result of the combination of current and wind wave parameters were performed. The laboratory research was carried out in a hydraulic flume with a wavemaker on the right bank and a levee with a slope of 1:3 installed on the left bank opposite the wavemaker. Waves were generated both perpendicular and oblique to the levee axis; the angle of oblique wave attack varied within the range of ± 30°. The aim of this paper is to compare the results of the mentioned research with recommendations mentioned in the Czech National Standard CSN 75 0255 Calculation of wave effects on water structures and to quantify the effect of current on the wave run-up height. and Jednou ze základních otázek spojených s bezpečností hráze je návrh převýšení její koruny nad maximální hladinou vzdouvané vody. Důležitým parametrem ovlivňujícím návrh převýšení je výška vln vybíhajících po svahu hráze. Běžné postupy výpočtu výšky výběhu vlny na svah jsou realizovány za předpokladu, že vlny vznikají na stojatých vodách. Vliv proudění se obvykle vzhledem k nízké úrovni znalostí tohoto jevu na tekoucích vodách zanedbává. V podmínkách České Republiky je otázka vlivu proudění na výšku výběhu relevantní zejména na velkých tocích jako Labe, Vltava nebo Morava. V rámci projektů Hydralab III a NAZV QI 92A139 byl uskutečněn hydraulický výzkum a analýza dat se speciálním zaměřením na výšku výběhu větrových vln při započtení vlivu proudění. Výzkum byl realizován na modelu hráze se sklonem svahu 1 : 3, který byl umístěn ve zkušební nádrži osazené vlnoproduktorem vedeným rovnoběžně s modelem hráze. Vlny zde byly generovány jednak kolmo vzhledem k podélné ose hráze, jednak šikmo v rozsahu úhlů ± 30°. Výsledky výzkumu byly porovnány s doporučeními uvedenými v České státní normě ČSN 75 0255 Výpočet účinků vln na stavby na vodních nádržích a zdržích.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31449. The influence of dietary lipid composition on skeletal muscle mitochondria from mice following eight months of calorie restriction
- Creator:
- Chen, Y., Hagopian, K., Bibus, D., Villalba, J. M., López, Lluch, G., Navas, P., Kim, K., and Ramsey, J. J.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, mitochondrie, mitochondrias, dietary lipids, energy restriction, phospholipids, reactive oxygen species, 14, and 612
- Language:
- English
- Description:
- Calorie restriction (CR) has been shown to decrease reactive oxygen species (ROS) production an d retard aging in a variety of species. It has been proposed that alterations in membrane saturation are central to these ac tions of CR. As a step towards testing this theory, mice were assigned to 4 dietary groups (control and 3 CR groups) and fed AIN-93G diets at 95 % (control) or 60 % (CR) of ad libitum for 8 months. To manipulate membrane composition, the primary dietary fats for the CR groups were soybean oil (also used in the control diet), fish oil or lard. Skeletal muscle mitochondrial lipid composition, proton leak, and H 2 O 2 production were measured. Phospholipid fatty acid composition in CR mice was altered in a manner that reflected the n-3 and n-6 fatty acid profiles of their respective dietary lipid sources. Dietary lipid composition did not alter proton leak kinetics between the CR groups . However, the capacity of mitochondrial complex III to produce ROS was decreased in the CR lard compared to the other CR groups. The results of this study indicate that dietary lipid composition can influence ROS production in muscle mitochondria of CR mice. It remains to be determined if lard or other dietary oils can maximize the CR- induced decreases in ROS production., Y. Chen ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31450. The influence of effective rainfall on modeled runoff hydrograph
- Creator:
- Šraj, Mojca, Dirnbek, Luka, and Brilly, Mitja
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- rainfall loss model, rainfall temporal variability, maximum rainfall position, rainfall runoff relationship, synthetic hyetograph, HEC-HMS, model odtoku, časová závislosť rozdelenia intenzít zrážok, čas maximálnej intenzity zrážky, závislosť zrážka-odtok, and syntetický hyetograf
- Language:
- Slovak
- Description:
- Influence of the pattern of effective rainfall on modeled hydrograph was investigated in the study. The modelling was performed with the U.S. Army Corps of Engineers hydrograph package HEC-HMS 3.2 and calibrated and validated on measured hydrographs of Glinscica watershed. Six different models of rainfall loss were applied and their effect on modeled hydrograph was evaluated. Peak discharge, time of peak discharge and runoff volume were compared. The best results with the lowest RMSE in the study was obtained with the SCS curve number loss method. Also synthetic hyetographs of different probability and duration were used. Three positions of the maximum rainfall intensity at 25, 50 and 75 % of the rainfall duration were applied. The results showed essential differences in simulated time to peak and also differences in peak discharge. The differences in time to peak increases considerably with the increasing of the rainfall duration. Finally, the results of constant intensity distribution of rainfall of different durations were compared with those obtained with typical rainfall distribution with the position of the maximum intensity at 50 %. Results showed considerable differences in peak discharge and time to peak by longer durations of the rainfall. and Práca obsahuje výsledky výskumu vplyvu efektívnych zrážok na modelovaný hydrograf. Odtok bol modelovaný pomocou nástroja U.S. Army Corps of Engineers hydrograph package HEC-HMS 3.2, potom kalibrovaný a verifikovaný na meraných hydrografoch povodia Glinscica. Vplyv zrážok na modelovaný hydrograf bol vypočítaný pre šesť rôznych modelov priebehu zrážok. Porovnali sme maximálne prietoky, časy ich trvania a odtečené množstvá. Najlepšie výsledky s najnižším RMSE sme získali s SCS modelom odtoku. Použili sme tiež syntetické hyetografy rozdielnej pravdepodobnosti a trvania. Použili sa tri polohy maximálnych intenzít zrážok; pre 25, 50 a 75 % ich trvania. Výsledky ukázali zásadný rozdiel v simulovaných časoch maximálneho prietoku a tiež rozdiely v maximálnych prietokoch. Rozdiely v časoch dosiahnutia maximálnych odtokov sa výrazne zvyšovali s časom trvania zrážky. Nakoniec sme porovnali výsledky výpočtov s konštantnými intenzitami rozdelenia s rôznym trvaním zrážky s tými, ktoré boli vypočítané s použitím typických rozdelení, s polohou maximálnej intenzity zrážok pri 50 % ich trvania. Výsledky ukazujú významné rozdiely v maximálnych prietokoch a v časoch ich dosiahnutia v závislosti od trvania zrážky.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public