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.
Transkatétrová implantácia aortálnej chlopne (Transcatheter Aortic Valve Implantation – TAVI) predstavuje intervenčnú metódu liečby závažnej aortálnej stenózy. TAVI je určená pre pacientov, ktorí boli tzv. srdcovým tímom (heart team) označení za chirurgicky inoperabilných resp. operabilných len pri veľmi vysokom operačnom riziku. Výhodou tohto terapeutického výkonu je miniinvazívnosť s absenciou sternotómie a potreby mimotelového krvného obehu. Intervenčná procedúra neumožňuje priamo (zrakovo) vizualizovať anatomické pomery v mieste implantácie (aortálny anulus). Z tohto dôvodu je nevyhnuté zabezpečiť presný obraz prostredníctvom kvalitného zobrazovacieho zariadenia. Štandardnou metódou posúdenia anatomických pomerov pred TAVI je multidetektorová počítačová tomografia (MDCT) s 3D rekonštrukciou. V budúcnosti by MDCT mohla byť nahradená trojrozmernou transezofageálnou echokardiografiou (3D TEE), ktorá na rozdiel od MDCT nie je zaťažená ionizačným žiarením, rizikom postkontrastnej nefropatie a hypersenzitívnej reakcie na jód. Navyše umožňuje usmerňovať intervenciu a zabezpečuje ľahšiu a lacnejšiu dispenzarizáciu pacienta. Multicentrická randomizovaná štúdia PARTNER jasne preukázala signifikantný prínos TAVI pre inoperabilných pacientov so závažnou aortálnou stenózou. Nedávno uverejnená CoreValve US Pivotal randomizovaná štúdia preukázala vyššiu efektivitu a bezpečnosť TAVI v priamom porovnaní s chirurgickou liečbou. Cieľom tohto prehľadového článku je sprostredkovať tie najaktuálnejšie informácie týkajúce sa TAVI, a to na úrovni predintervenčnej prípravy, priebehu intervencie, dispenzarizácie ako aj ovplyvnenia kvality života pacientov., Transcatheter aortic valve implantation (TAVI) is an interventional method for the treatment of severe aortic stenosis. TAVI is indicated in patients who have been identified by the heart team as surgically inoperable or operable at very high risk. The advantage is minimal invasive approach with the absence of sternotomy and extracorporeal blood circulation. Interventional procedure does not allow direct visualization of the anatomical relations at the site of the final valve position (aortic anulus). For this reason it is essential to ensure appropriate view by high quality imaging methods. A standard method for the evaluation of the anatomical relations before TAVI is multidetector computed tomography (MDCT) with 3D reconstruction. In the future, the MDCT would be replaced by three-dimensional transesophageal echocardiography (3D TEE), which does not require ionizing radiation, there is no postcontrast nephropathy and hypersensitive reaction to iodine compared to MDCT. Furthermore, it provides direct measurements during the procedure and ensures easier and cheaper dispensarisation of the patients. A multicenter randomized PARTNER trial clearly demonstrated significant benefits of inoperable patients with severe aortic stenosis treated by TAVI. Recently published CoreValve US Pivotal randomized trial demonstrated higher efficiency and safety of TAVI in direct comparison with surgical treatment. The aim of this review is to provide current knowledge of TAVI, preparation of the patients before the intervention, the process of intervention, dispensarisation, as well as affecting the quality of patients life., and Marián Kurečko, Gabriel Valočik, Marianna Vachalcová, Mariana Dvorožňáková
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
In this paper, we give necessary and sufficient conditions on $(p_n)$ for $| R,p_n| _k$, $k\ge 1$, to be translative. So we extend the known results of Al-Madi [1] and Cesco $\left[ 4\right] $ to the case $k>1$.
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., 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., and Adam Doležal, Petr Agha
The European hedgehog, Erinaceus europaeus Linnaeus, 1758, is a common host of Ixodes ricinus L. and I. hexago-nus Leach, vectors of the Lyme disease spirochaete, Borrelia burgdorferi sensu iato. To investigate whether hedgehogs are reservoirs for li- burgdorferi, hedgehogs were captured in a suburban area suitable for both tick species and in an urban area where /. ricinus is absent. The infection status of the hedgehogs was determined by xenodiagnosis using I. ricinus and I. hexagonus larvae. /. hexagonus and/or I. ricinus were found on all hedgehogs (n = 8) from the suburban area. In contrast, only I. hexagonus was infesting animals (n = 5) from the urban area. A total of 12/13 hedgehogs harboured B. burgdorferi infected ticks. Xeno-diagnostic I. ricinus and I. hexagonus larvae that fed on hedgehogs became infected. The results clearly show that European hedgehogs are reservoir hosts of the Lyme disease spirochetes. DNA of B. burgdorferi sensu stricto, В. garinii and В. afzelii was detected in culture from ear biopsy and needle aspiration material and characterized by using a genospecies-specific PCR assay. One hedgehog presented a mixed infection of the skin with fi. burgdorferi sensu stricto and fi. garinii. This study also identifies an enzootic transmission cycle in an urban area involving E europaeus and /. hexagonus. The close association of /. hexagonus with the burrows of its hosts mean that the risks of contact between /. hexagonus and humans may be low.
In the adult fish trematode Crepidostomum metoecus (Braun, 1900), four types of sensory receptors were observed inside the forebody tegument and one type beneath the tegument basal lamina. Two types of sensory receptors extend through the thickness of tegument and have a free cilium inside a pit (types I and II). Two types (III and IV) are nonciliate and entirely intra-tegumental in location. Type IV receptor with large horizontal and thin vertical rootlets was described earlier in aspidogastreans only. Below the basal lamina, nerve endings in close association with muscle fibres, comparable with those in the Aspidogastrea, were detected.
Five types of presumed ciliate sensory receptors were detected in the forebody papillae of the adult fish trematode, Crepidostomum metoecus (Braun, 1900). The cilia are short and submerged in a tegumental pit. The apical bulb part of all types of receptors observed is supported by a dense collar and connected to the tegument basal plasma membrane by a circular septate junction. In sensory receptors types I and III no rootlet is present; the bulbs of sensory receptors types III and IV contain an electron-dense formation.
Extrasporogonic stages of Sphaerospora sp. from the kidneys of Atlantic salmon (Salmo salar L.) were successfully transmitted via intra-peritoneal injection to naive Atlantic salmon and brown trout (Salmo trutta L.). Rainbow trout (Oncorhynchus mykiss Walbaum) could not be infected in this way. Transmitted extrasporogonic stages continued their development to form sporogonie stages and mature spores in the kidney tubules. Extrasporogonic stages, sporogonie stages and mature spores of the parasite in both experimentally infected hosts were morphologically identical to the equivalent stage in naturally infected Atlantic salmon, although minor differences were seen in spore dimensions. A farm-based exposure experiment confirmed the susceptibility of brown trout to the salmon Sphaerospora, These results are consistent with the view that the salmon Sphaerospora is Sphaerospora truttae Fischer-Scherl, El-Matbouli et Hoffmann, 1986. The parasite is redescribed according to the guidelines of Lom and Arthur (1989) since details of extrasporogonie stages, the ultrastructure of extrasporogonic and sporogonie stage development, and of the parasite’s epidemiology are known from Atlantic salmon but not from other reports.