Následující řádky přinášejí informaci o významném buněčném mechanismu, který pomáhá udržovat energetickou rovnováhu buněk v okamžicích náhlého zvýšení požadavku na dodávku energie. Tento mechanismus také usnadňuje přenos energeticky bohatých substrátů v buněčném prostoru k místům jeho spotřeby a je zvláště rozvinutý v buňkách, jejichž požadavky na dodávku energie v průběhu času značně kolísají a jsou schopné vysokého výkonu. Můžeme jej pozorovat ve svalových vláknech, srdečních myocytech, neuronech, ale i ve spermatických buňkách, které se po probuzení k aktivitě pokouší vyhrát závod s ostatními a splnit tím svoji biologickou úlohu., The article presents information on an important cell mechanism that helps to maintain the energy balance in cells at moments when there is a sudden increase in demand for energy supply. This mechanism also facilitates the transfer of energy-rich substrata in cellular space to the locations of its consumption, and it is particularly well-developed in cells that are capable of high performance and their energy requirements vary considerably over time. We can observe it in muscle fibres, cardiac myocytes, neurons and sperm cells., and Jitka Žurmanová.
Puchýřka útlá (Coleanthus subtilis) je vysoce ekologicky specializovaný druh jednoleté trávy (čeleď lipnicovité - Poaceae), rostoucí ve vodních nádržích a tocích po dočasném poklesu vodní hladiny. Přežít na stanovištích, která často podléhají rychlým a nečekaným změnám, jí napomáhá řada adaptací, např. velmi krátký vývojový cyklus (5-7 týdnů) a jeho proměnlivost v závislosti na konkrétních podmínkách prostředí, drobná, snadno šiřitelná semena a tvorba dlouhodobé semenné banky. Je rozšířena na třech kontinentech, avšak nejvíce lokalit je známo z rybníků v České republice, zejména v jihočeských rybničních pánvích a na Českomoravské vrchovině. Vedle příznivé kombinace přírodních faktorů (klima, geologická stavba) se za velkou koncentrací lokalit na našem území nepochybně skrývá pozoruhodná synchronizace životního cyklu puchýřky s po staletí se opakujícím hospodářským cyklem chovu kapra., Coleanthus subtilis, a highly ecologically specialised annual grass species (Poaceae), grows in water bodies and watercourses after a temporary decrease of water level, and shows a range of adaptations to this habitat subjected to fast and unexpected changes (e.g., short life cycle, phenotypic plasticity, small, easily dispersible seeds, long-term soil seed bank). The highest number of sites is known from the Czech Republic (especially South Bohemian fishpond basins and the Bohemian-Moravian Uplands). Besides natural factors (climate, geology), the remarkable synchronisation of Moss Grass life cycle with the farming cycle of Common Carp (Cyprinus carpio) is undoubtedly the reason for its disjunct distribution., Kateřina Šumberová, Michal Ducháček., and Obsahuje seznam literatury
Pro rok 2016 se evropským pavoukem roku stal křižák Cyclosa conica. Po morfologické stránce je tento druh nezaměnitelný díky přítomnosti hrbolku na zadním konci hřbetu zadečku. Jeho kolová síť je vybavena vertikálním stabilimentem se zapředenými zbytky kořisti či detritu. Pavouk na kořist číhá uprostřed stabilimenta. Při ohrožení je schopen na síti vibrovat tak, že se pro predátora stane takřka nedetekovatelným., The araneid Cyclosa conica was chosen as European Spider of the Year for 2016. Morphologically the spider is characterised by a single tubercle on the hind part of the dorsal abdomen. Its web carries a vertical stabilimentum with remnants of prey and other detritus. The spider waits for its prey in the middle of the stabilimentum. When disturbed, it vibrates on the web, so it becomes almost undetectable., and Milan Řezáč.
Armenia is a small country situated in the Transcaucasus on the border of Europe and Asia. For visitors from Central Europe, the huge landscape variety from the perspective of geological, geomorfological and climatic factors is surprising, as well as the vegetation and floristic diversity. Here alpine vegetation, semideserts, phryganoid vegetations and mountain steppes occurre in the same area, together with interesting forest vegetation types. Beautiful country - side rich in ancient historical monuments is a great treasure for this small country lying at the crossroads of cultures, biogeo - graphical regions and migration routes. and Ester Ekrtová, Libor Ekrt.
Forest vegetation occupied some 20 % of this Armenian area, with forests of three types. Open forests consist of short, rather sparse trees (juniper/pistachio/oak). Alluvial vegetation occurs as a narrow belt of trees or scrub along rivers and streams. Deciduous forests usually develop in more humid places and may show interesting parallels to our lowland and upland forests. Traditional management (in Europe practi - sed in the past) is maintained, providing an inspiration for our nature conservation. and Ester Ekrtová, Libor Ekrt.
In Armenia, more than 50 % of the territory lies at an altitude of over 2 000 metres a. s. l. The overall landscape and the mountain flora and vegetation are determined by volcanic areas alternating with crystalline massif or limestone areas. and Ester Ekrtová, Libor Ekrt.
The extremely dry lower altitudes of Armenia are occupied by semi-desert and phryganoid xerophyte plant communities with many rare endemics, useful wild plant species and wild relatives of cultivated plants. The rather high proportion of semi- -desert vegetation was transformed to agricultural areas due to irrigation. At higher altitudes, steppes and meadow-steppes are abundant and thorn-cushion communities are rather widespread too. In regions with high annual precipitation, meadows represent species rich and ornamental forest-free vegetation. and Ester Ekrtová, Libor Ekrt.
This article provides a brief summary of initiatives to establish the National Park in 1963 and describes the first activities in its administration and the problems it faced under the impact of industrial pollution in the 1980s. In that time, it was put on the list of the 12 most endangered national parks in the world. In the 1990s the cooperation of the Dutch FACE Foundation with its fi nancial support, the University of Amster dam with its scientific expertise and the enthusiasm of the National Park working team gave rise to a restoration process, which is still going on to this day, bringing the park back to its position as one of the most valuable natural areas in the country. and Josef Fanta.
During a survey the occurrence of Kudoa quraishii Mansour, Harrath, Abd-Elkader, Alwasel, Abdel-Baki et Al Omar, 2014, recently identified in the muscles of the Indian mackerel, Rastrelliger kanagurta (Cuvier), a species of Kudoa Meglitsch, 1947 infecting oocytes of mature females of the same host fish was found. The new species, for which the name Kudoa saudiensis sp. n. is proposed, infects oocytes that are enlarged with a whitish colour. The parasite develops in vesicular polysporous plasmodia within the oocyte. Infection occurs with a mean prevalence of 20% (7/35) of examined females. Mature spores are quadratic in shape in apical view, having four equal valves and four symmetrical polar capsules. Fresh spores are 2.4-3.6 µm long (mean ± SD 3.1 ± 0.3 µm), 4.3-5.4 µm (4.7 ± 0.3 µm) wide and 3.4-4.3 µm (3.8 ± 0.3 µm) in thickness and long. The smaller size of the new Kudoa species was the distinctive feature that separates it from all previously described species. Molecular analysis based on the SSU rDNA sequences shows that the highest percentage of similarity of 98.5% was observed with K. ovivora Swearer et Robertson, 1999, reported from oocytes of labroid fish from the Caribbean coasts of Panama. The percentage of similarity was 98% with K. azevedoi Mansour, Thabet, Chourabi, Harrath, Gtari, Al Omar et Ben Hassine, 2013 and 89% with K. quraishii. Phylogenetic analysis of the SSU and LSU rDNA data revealed a consistent of the new species with K. azevedoi and K. ovivora. Our findings support the creation of Kudoa saudiensis sp. n. that infects oocytes of the Indian mackerel Rastrelliger kanagurta., Lamjed Mansour, Abdel Halim Harrath, Abdel-Azeem S. Abdel-Baki, Saleh Alwasel, Saleh Al-Quraishy, Suliman Y. Al Omar., and Obsahuje bibliografii