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
This paper presents a new technique for fingerprint image matching in biometric security applications, based on the hybrid of Neural Network and Delaunay Triangulation methodology. The Delaunay triangulation of the minutiae set is transformed to a set of points in the discretized space using duality. This translation results in a sampling method be acquiring which the system tolerates displacement and noise of the input image. Finally, Transiently Chaotic Associative Network (TCAN) is used to learn the obtained pattern. Experimental results show a significant improvement in the False Rejection Rate over both the traditional Delaunay Triangulation based approach and direct Neural Network application.
Amphicrossus japonicus is the first known facultatively aquatic nitidulid. The adult beetles breed in bamboo sap and subsequently enter water-filled bamboo culms. In water they breathe via a ventral air sheath held by hydrofuge pubescence. The beetles are facultative predators and hunt mosquito larvae, which they grab with their forelegs. The trend to facultative predation in Cucujoidea and the transition for beetles in general from semi-liquid decaying organic matter into water is discussed.
Central pattern generators (CPGs) play an important role in controlling rhythmic movements in vivo. Increased insight into mechanisms of CPGs can be obtained by perturbing neuron activities so as to study a range of behaviors. By applying this method, a series of simulations were performed to research different transition modes between firing patterns in a pacemaker neuron model of stomatogastric ganglion (STG). Firstly, with the perturbation of parameters in model, such as external stimulus, parameters in compartments and connection between compartments, different firing patterns and bifurcation of inter-spike intervals (ISIs) were obtained to exhibit the impact of single parameter on the transions between spiking and bursting. Moreover, perturbing two parameters gCa, Iext simultaneously induced the continuous variation of the bifurcation mode, which implied the crucial role of calcium channel in regulating the rhythm generation. Finally, a two-dimensional parameter space (gCa, Iext) was constructed by spike-counting method to capture the distribution of the firing patterns and different transition mode between them in a comprehensive aspect. In this parameter space, three basic transition modes were concluded: bifurcation ring, period-doubling mode and period-adding mode.
The distributions of the tetraploid Anthoxanthum odoratum and diploid A. alpinum were first studied in the Krkonoše Mts (part of the Sudetes Mts) to find the transition zone where both species occur together and then their ecological requirements in this zone were determined. The distribution was studied at two spatial scales, geographic and local; the latter included detailed distribution at a locality level, where the relationships of both species to plant communities were investigated. The zone where the overlap occurs is between 800–1290 m a.s.l. Anthoxanthum alpinum is able to descend to even lower altitudes, where it grows in vegetation dominaned by Nardus stricta. The species commonly occur in a fine mosaic of plant communities of Polygono-Trisetion (A. odoratum), Nardion (A. alpinum) or Nardo-Agrostion tenuis (both species). Anthoxanthum alpinum also occurs in areas that are currently not in direct contact with either alpine or subalpine vegetation (the Rýchory ridge, Černá hora Mt).
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