The effect of the chronic and acute antioxidant tempol (superoxide dismutase mimetic) treatment on cardiac ischemic tolerance was investigated in adult male Wistar rats. The first experimental group was given tempol (1 mM) in drinking water for three weeks, the second group received tempol (100 mg/kg, i.v.) 10 min before test ischemia, and control rats received the same volume of solvent. Anesthetized open-chest animals (pentobarbitone 60 mg/kg, i.p.) were subjected to 20-min coronary artery occlusion and 3-h reperfusion for infarct size determination. Ventricular arrhythmias were monitored during ischemia and at the beginning (5 min) of reperfusion. Acute tempol administration shifted the time profile of ischemic arrhythmias to the later phase and significantly increased the number of ischemic and reperfusion premature ventricular complexes, respectively (504±127 and 84±21) as compared with the chronically treated group (218±36 and 47±7) or controls (197±26 and 31±7). Acute tempol-treated rats exhibited a tendency to decrease infarct size (P = 0.087). The mechanism of proarrhythmic tempol action during ischemia and reperfusion remains to be elucidated., J. Neckář, B. Ošťádal, F. Kolář., and Obsahuje bibliografii a bibliografické odkazy
Diapause is a common dormancy strategy exhibited by many species of invertebrates and insects to temporarily avoid seasonally recurring unfavourable conditions for their development, most usually in winter. Less frequently, a prolonged diapause lasting two or more years is described in species living in unpredictable environments where it is adaptive, but with significant costs. In this paper we examine the occurrence of prolonged diapause in the lycaenid butterfly Tomares ballus. Pupae of this species undergo an obligate diapause from mid-May to late January the following year. However, during our rearing experiments (from 2009 to 2016) the emergence of adults occurred sequentially and a fraction of the pupae remained in diapause for up to seven years. The annual percentage emergence after the first year of diapause was 45.6%, and only barely exceeded 50.0% in 2015. Remarkably, 12 pupae (11.4% of the initial brood) remained in diapause in their eighth year. The negative exponential equation fitted to the emergence data suggests that further emergences may occur within the next five years. Therefore, the potential for successful prolonged diapause of T. ballus pupae may be more than 10 years. The adaptive value of this strategy is discussed in relation to the effects of adverse and unpredictable weather during the flight period of the butterfly, intra-guild competition, parasitoids and changes in habitat quality. We suggest that this strategy may also be exhibited by other species of Mediterranean lycaenids., Rafael Obregón, Juan Fernández Haeger, Diego Jordano., and Obsahuje bibliografii
Dlouhou dobu se předpokládalo, že populace obývající určitá území Evropy také tato území na konci doby ledové kolonizovaly jako první. Nové výzkumy však ukázaly, že v některých případech byla první příchozí populace později nahrazena jinou, pocházející z jiného glaciálního refugia. Náš článek ukazuje, že k takovému nahrazení jedné populace druhou došlo při kolonizaci Velké Británie norníkem rudým (Clethrionomys glareolus) a že při tom hrály roli fyziologické adaptace způsobené mutací v hemoglobinu., It has long been assumed that the populations that first colonized particular empty territory after the last ice age have remained there until the present day. However, recent findings in small mammals suggest that replacements involving a population from one glacial refugium at the cost of a population from another refugium may have been a not infrequent event. The article demonstrates that such population replacement took place during post-glacial colonization of Great Britain by the Bank Vole (Clethrionomys glareolus) and that physiological differences conferred by haemoglobin have probably played a role in this process., and Petr Kotlík, Silvia Marková, Karolína Filipi, Michaela Strážnická, Jeremy B. Searle.
Serum levels of adiponectin were measured in patients with benign prostatic hyperplasia and prostate cancer of pT2 and pT3 stage. Adiponectin ELISA assay, immunohistochemistry, and selected metabolic and biochemical parameters measurement was performed in 25 patients with benign prostatic hyperplasia and 43 with prostate cancer (17 patients with organ-confined and 26 patients with locally advanced disease). Serum adiponectin levels did not differ between prostate benign hyperplasia and cancer clinical stage T2, but was significantly higher in pT3 relative to pT2 group (14.51± 4.92 vs. 21.41±8. 12, P = 0.003). Tissue immunohistochemistry showed enhanced staining in neoplastic prostate glands and intraepithelial neoplasia relative to benign prostatic hyperplasia without distinction between disease grade and stage. Serum adiponectin levels are higher in locally advanced relative to organ-confined prostate cancer and may thus serve as an auxiliary marker providing further improvement for discrimination between pT2 and pT3 stages., D. Housa, Z. Vernerová, J. Heráček, B. Procházka, P. Čechák, J. Kuncová, M. Haluzík., and Obsahuje bibliografii a bibliografické odkazy
Ve střední Evropě (Česko, Maďarsko a Polsko) jsme zaznamenali 9 případů zajímavé adopce mláďat káně lesní (Buteo buteo) v hnízdech orlů mořských (Haliaeetus albicilla). Adoptovaná mláďata byla v dobré kondici, dospělí orli mořští se o ně starali a mláďata byla nakonec úspěšně vyvedena., Nine interesting cases of young Common Buzzards (Buteo buteo) adopted in nests of White-tailed Sea Eagle (Haliaeetus albicilla) in central Europe (Czech Republic, Poland and Hungary) are reviewed. The B. buteo nestlings adopted were in good condition, the adult H. albicilla fed and cared for them properly, and the young birds successfully fledged., and Ivan Literák, Jakub Mráz.
1_The adult demographic parameters, mobility, nectar choice and how the spatial distribution of males and females of Z. polyxena is affected by the distribution and abundance of host-plants, and adults of the opposite sex was studied in a population of this species inhabiting a dense network of permanent habitats (totalling 8.7 ha). The population size was estimated to be ca. 300 individuals. The average adult lifespan was 4.4 days and the maximum 23 (male) and 20 (female) days. The capture probability was higher for males than females due to the more conspicuous behaviour and bounded area of activity of males. A slow increase was followed by a slow decrease in the sex specific parabolic recruitment curve, indicating slight protandry and long emergence period, probably due to habitat heterogeneity. The spatial distribution of host plants (Aristolochia lutea) is the key factor determining the spatial distribution of adults. There was a strong positive correlation between male and female density at each patch, both of which were dependent on the cover of host plants growing in sunny conditions. In searching for A. lutea plants suitable for oviposition, females fly greater distances and move more frequently between patches than males. The size, shape and orientation of the male home range were influenced by the size, shape and orientation of stands of host-plants in sunny positions, but not by patch area. Such adult fidelity to stands of host-plants in sunny positions indicates that the spatial distributions of oviposition sites, mate-locating sites and larval habitats of Z. polyxena overlap. The better statistical fit and much lower probabilities for long-distance movements generated by a negative exponential function than an inverse power function are probably due to the small size and high habitat connectivity of the site studied. Adults were opportunistic in their use of nectar plants., 2_Traditional management is the key factor for maintaining permanent habitats for this species in a grassland biotope., Tatjana Čelik., and Obsahuje seznam literatury
The central-marginal model is widely accepted in chromosomally polymorphic species of Drosophila. In fact, geographically and ecologically central populations of Drosophila show higher levels of polymorphism for paracentric inversions, whereas marginal populations tend to be monomorphic. This fact has been variously explained. Chromosomal polymorphisms in grasshoppers have also been attributed to show such geographical structuring, as in the case of the South-American grasshopper Dichroplus pratensis Bruner (Orthoptera: Acrididae). However, in three other cases involving Acrididae – Leptysma argentina Bruner, Trimerotropis pallidipennis (Burmeister) and Cornops aquaticum (Bruner), it is clear that chromosomal polymorphisms (sometimes with a wide extension over the Argentine area) do not conform to this pattern, and show instead clear correlations with environmental variables, especially minimum temperature, showing low or null frequencies of the rearrangements at one extreme of the environmental gradient and with high or fixed frequencies at the other. Furthermore, this correlation with temperature might also be true in the case of D. pratensis. These aforementioned examples emphasise the dangers of over-generalization when discussing chromosomal polymorphisms, and suggests that such polymorphisms should be considered very much in a case-specific manner in terms of the particular genetic system under study., Pablo C. Colombo., and Obsahuje seznam literatury
Článek podrobně popisuje autorovo neobvyklé setkání s kojoty (Canis latrans) v roce 2010 v kostarickém národním parku Braulio Carillio v části Sector Volcán Barva. Pořízené dokumentační fotografie umožnily analyzovat agresivní chování kojotů vůči člověku a jeho etologickou interpretaci na základě znalostí etologie psovitých šelem., In August 2010, the author visited Braulio Carrillo National Park in Costa Rica and approached three coyotes (Canis latrans). The article describes their attack, probably due to maternal aggression combined with fear-induced and territorial aggressions., and Ivan Literák.
Agrolesnické systémy v tropických oblastech nabízejí možnost, jak zajistit trvale udržitelnou produkci na obdělávaných pozemcích, a často představují jediný zalesněný ekosystém v okolní odlesněné krajině. Tento článek se věnuje problematice agrolesnictví v tropech se zaměřením na kávové plantáže pěstované v Peru., Agroforestry systems present a way to keep sustainable production in cultivated areas, especially in the tropical zone. At the same time it is often the only forested ecosystem in otherwise deforested landscape. This article is about agroforestry in tropical areas, with the focus on coffee (Coffea) plantations in Peru., and Lenka Ehrenbergerová.
Ground-dwelling sciurids, including prairie dogs (Cynomys), marmots (Marmota) and several genera of ground squirrels (e.g. Ammospermophilus, Spermophilus, Notocitellus, Ictidomys, Urocitellus), emit alarm calls in the presence of predators to warn their kin. These calls show high intra- and inter-species variation. The alarm calls of many species have potential to encode information about caller identity, and possibly enable the ground squirrels to recognize unreliable callers or to estimate the degree of risk. The alarm calls can be used to determine species or subspecies, and can also help resolve some taxonomic complexities. and Irena Schneiderová.