The novel environment of a metabolic cage can be stressful for rodents, but few studies have attempted to quantify this stress-response. Therefore, we determined the effects on mean arterial pressure (MAP) and heart rate (HR), of placing mice of both sexes in metabolism cages for 2 days. After surgical implantation of a carotid artery catheter mice recovered individually in standard cages for 5 days. Mice then spent 2 days in metabolism cages. MAP and HR were monitored in the standard cage on Day 5 and in metabolism cages on Days 6-7. MAP increased by 18±3 and 22±4 %, while HR increased by 27±4 and 27±6 %, in males and females, respectively, during the first hours after cage switch. MAP decreased to baseline in the fourth and eighth h following metabolism cage switch in males and females, respectively. However, HR remained significantly elevated in both sexes during the entire two-day period in metabolism cages. Females had lower MAP than males both pre- and post- metabolism cage switch, but there were no sex differences in HR. These results demonstrate sustained changes in cardiovascular function when mice are housed in metabolism cages, which could potentially affect renal function., C. C. Hoppe ... [et al.]., and Obsahuje seznam literatury
To achieve a better understanding of learning and declarative memory under mild transient stress, we investigated the effect of brief hypobaric hypoxia on spatial orientation in rats. Young male Wistar rats aged 30 days were exposed for 60 min to hypobaric hypoxia, simulating an altitude of 7000 m (23 000 ft) either shortly prior to attempting or after mastering an allothetic navigation task in the Morris water maze with a submerged platform. The post-hypoxic group performed significantly better in the navigation task than the control animals (the mean difference in escape latencies was 11 seconds; P= 0.0033, two-way ANOVA with repeated measures, group × session). The experimental group also achieved a remarkably higher search efficiency (calculated as a percentage of su
ccessful trials per session), especially during the first four days following hypoxic stress (P= 0.0018). During the subsequent training, the post-hypoxic group performed better than the control animals, whilst the efficiency levels of both groups progressively converged. Spatial memory retention and recall of well-trained rats were not affected by the transient hyp
obaric hypoxia. These results indicate that brief hypobaric hypoxia enhances rats’ spatial orientation. Our findings are consistent with several studies, which also suggested that mild transient stress improves learning.
Protein kinase C (PKC) appears to play a significant role in the signal transduction of cardiac growth and development. The aim of this study was to determine changes in the total PKC activity and the expression of PKC isoforms α, δ and ε in the rat heart that was affected by pressure overload imposed at postnatal day (d) 2. Three groups of Wistar rats were employed for the experiment: rats submitted to the abdominal aortic constriction (AC), sham-operated controls (SO) and intact controls. Animals were sacrificed at d2, d3, d5 and d10. The total PKC activity was measured by the incorporation of 32P into histone IIIS and the expression of PKC was analyzed by immunoblotting in the homogenate of the left ventricular myocardium and in the cytosolic, membrane-enriched (105 × g) and nuclear-cytoskeletalmyofilament- enriched (103 × g) fractions. We observed the significant transient increase in both the total PKC activity and the expression of all isoforms at d5 (the 3rd day after the operation) in the cardiac homogenate of AC rats as compared with SO animals. Aortic constriction did not significantly affect the distribution of activity and isoform abundance among individual cellular fractions except for PKCδ, which increased significantly at d10 in the cytosolic fraction at the expense of the membraneenriched fraction. It is concluded that PKCα, PKCδ and PKCε undergo transient upregulation associated with the accelerated cardiac growth induced by pressure overload imposed in the very early postnatal period., B. Hamplová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Chlorophyll (Chl) fluorescence temperature cinve (FTC) of primary leaves of spring barley (Hordeum vulgare L.), cultivated imder a low irradiance, was studied at low actinic radiation excitation (436 nm, 2 W m'^) under a heating regime consisting of a linear increase of temperature (0.083 °C s’*), followed by a period of constant temperature. After prompt cooling of the sample to 77 K, Chl fluorescence spectra at defined points of the temperature regime were measured. Two distinct temperature and kinetic regions expressed by two discemible temperature maxima were observed for ťhis type of the FTC. Two triggering temperatures of successive irreversible changes are postulated at 45-48 “C and 53-55 °C temperature intervals, respectively; they may correlate with the heat inactivation of photosystem 2 and with changes of the chloroplast and cytoplasmic membrane integrity.
The article aims to introduce and explore the concept of „transculturation". Unlike the affiliated concept of „acculturation", capitalized widely in anthropology, sociology and other branches of social Sciences, the concept of transculturation had until recently commanded little attention outside the limited area of Latin American studies. The concept, originally formulated in the 1940s by Cuban sociologist Fernando Ortiz, accentuates the mutual character of cultural interaction, the active participation of „subordinate" groups in the process, as well as the unique character of the resulting cultural formation. That is,
the processes of enforced cultural exchange (for example, through colonial expansion) are preceived as not only destructive, but also Creative. While the concept of transculturation had commonly been applied within the frame of American or African history and anthropology, the present article proposes the advantages and possibilities of its use in the study of (Central) European millieu - be it in the study of German-Jewish-Czech interaction in the nineteenth century, or in the study of Protestant-Catholic cultural exchange after the year 1620.
Newtonova latinská formulace prvního zákona pohybu je od prvního překladu Principií (A. Mott 1729) až po současnost interpretována ve smyslu zákona setrvačnosti rovnoměrného přímočarého pohybu. Newton však svou formulací prvního zákona ve spojení s komentářem k ní vyjádřil zákon setrvačnosti rovnoměrného pohybu i rotačního. Je to dokázáno na základě Newtonových rukopisů a údajů v Príncípiích. Je navrženo odpovídající správné znění prvního zákona ve fyzikální literatuře a v učebnicích. Těleso setrvává ve svém stavu klidu nebo rovnoměrného pohybu [postupného, rotačního] v daném směru, pokud není působícími silami nuceno tento stav měnit., Newton‘s latin enunciation of the First law of motion is interpreted beginning with the first translation of the Principia till nowadays, in the sense of the law of the uniform rectilinear motion. Newton expressed, however, by his enunciation of the First law in connection with the commentary to it also the law of inertia of the unifom rotatory motion. This is proved on the basis of Newton's manuscripts and of the data given in the Principia. Corresponding correct wording of the First law is proposed to be used in the physical literature and in the textbooks., Martin Černohorský., and Obsahuje seznam literatury
By an analysis of the Brock’s model tests (Brock, 1969) conditions for forming of roll-waves are determined together with experimental equations of their parameters in relation to the channel inflow wave (Kunštátský, Maleňák, Pejchal, 1967; Kybast, 2002), aeration of flow (Douma, 1943; Haindl, Lískovec, 1973), channel slope and roughness along the whole range of the water flows. Calculations of lower and upper flow roll-waves discharge, depths, velocities, time periods, wave distances and volumes are presented. and Rozborem Brockových modelových zkoušek (Brock, 1969) jsou určeny podmínky tvoření translačních vln a experimentální rovnice jejich parametrů v souvislosti s rázovou vlnou napouštění koryta (Kunštátský, Maleňák, Pejchal, 1967; Kybast, 2002), s provzdušněním proudu (Douma, 1943; Haindl, Lískovec, 1973), sklonem koryta a s jeho drsností v celém rozsahu tohoto proudění vody. Předložen je výpočet dolního proudu a horního proudu s translačními vlnami, jejich průtoků, hloubek a výšek, rychlostí, časových period, vzdáleností a objemů vln.
Toto speciální vydání Časopisu zdravotnického práva a bioetiky je číslem mono-tematickým, které se zaměřuje na problematiku translidí, pohlavní identity a právního diskursu v této oblasti. Poukazuje na problémy, se kterými se translidé v praktickém životě setkávají. and This special issue of Journal of Medical Law and Bioethics is mono-thematic and focuses on transgender issues, sexual identity and legal discourse in this area. It highlights the problems transgender people meet in real life.
At various intervals after inoculation of the roots of groundnut plants with the fungus Macrophomina phaseoli, 14CO2 was administered to branch 2 (from the base) of the plants in the light. The effects of the disease on the translocation of 14C-photosynthates out of the source branch to the rest of the plant were studied 24 h after labelling. As the plant aged and the disease symptom development became more evident, an increasing percentage of the fixed 14C-photosynthates was exported from branch 2 of the inoculated plants (IP) compared to the non-inoculated plants (NIP). The apex, main stem, and branch 1 of NIP imported more of the total fixed 14C throughout the developmental stages of the plant except for day 10 after inoculation when branch 1 of IP imported almost 76 % of the total fixed 14C. The roots of IP were the major sink and imported higher percent of the total fixed 14C than the roots of NIP.