Photothrombotic model of ischemia (PT) is based on free radical-mediated endothelial dysfunction followed by thrombosis. Free radicals are also involved in hypoxic preconditioning. We tested the sensitivity of PT to preconditioning with hypobaric hypoxia and to pretreatment with melatonin. In adult Wistar rats, after intravenous application of Rose Bengal, a stereo-tactically defined spot on the denuded skull was irradiated by a laser for 9 min. The first experimental group underwent hypobaric hypoxia three days before irradiation. In the second experimental group, melatonin was applied intraperitoneally one hour before irradiation. Three days after irradiation, animals were sacrificed, the brains perfused, and stained with TTC. Ischemic lesions were divided into grades (I, II, III). In the control group (where no manipulation preceded photothrombosis), most animals displayed deep damage involving the striatum (grade III). The group pre-exposed to hypoxia showed similar results. Only 28.57 % of the melatonin pretreated animals exhibited grade III lesions, and in 57.14 % no signs of lesions were detected. Pre-exposure to hypoxia was not protective in our model. Pretreatment with melatonin lead to a significant reduction of the number of large ischemic lesions. This result is probably caused by protection of endothelial cells by melatonin., I. Matějovská, K. Bernášková, D. Krýsl, J. Mareš., and Obsahuje bibliografii a bibliografické odkazy
Surface deformation due to underground exploitation affects the safety of overlying structures. Forecasting can predict risks to surface structures and facilitates actions designed to improve their resilience and reduce the potential impact of mining activities. However, forecasting accuracy is limited. Therefore, in practice, model parameters are determined within a certain margin to ensure that critical values of deformation indicators for surface objects are not exceeded. For economic reasons, it is important to minimize these margins while also ensuring that safety is maintained. One important factor influencing forecasting accuracy is the uncertainty in deformation model parameters used for calculations. Therefore, it is critical to adopt an appropriate methodology for determining and addressing the uncertainties in deformation model parameters used in forecasting. This study presents methods for estimating the Knothe's model parameters needed to forecast surface deformation caused by underground mining and defining the uncertainties in those forecasts. Depending on the parameter uncertainties, one of two methods for propagation is proposed: the Monte Carlo method or the law of propagation of uncertainty. Using this approach, it is possible to account for uncertainty and reduce forecast margins. A case study of hard coal mining in the Upper Silesian Coal Basin region of Poland is presented., Wojciech Gruszczyński, Zygmunt Niedojadło and Dawid Mrocheń., and Obsahuje bibliografii
Spalangia cameroni Perkins (Hymenoptera: Pteromalidae) is sold commercially as a biocontrol agent of filth flies, including the house fly, Musca domestica L. (Diptera: Muscidae). For this reason, S. cameroni is mass-reared for inundative releases to control harmful flies. However, the mass-rearing protocols include very little information on the influence of natal host on subsequent host selection by parasitoids with more than one potential host as in the genus Spalangia. Here, we report on the use of S. cameroni against M. domestica. The S. cameroni were reared using Ceratitis capitata Wiedemann (Diptera: Tephritidae) (natal host) pupae for several generations. Freeze-killed fly pupae were used in assays to determine the fecundity, number of adult progeny and sex-ratio of this parasitoid. Realized fecundity and number of adult progeny were greater when provided with house fly pupae than Mediterranean fruit fly pupae. Thus S. cameroni parasitized more house fly pupae than C. capitata pupae, even though the parasitoid was reared on Mediterranean fruit fly for many generations. These results indicate that S. cameroni reared on C. capitata can be successfully used in inundative releases against both fruit flies (agriculture) and house flies (livestock farming)., Francisco Beitia, Erik Valencia, Bernat Peris, Luis De Pedro, Josep D. Asís, José Tormos., and Obsahuje bibliografii
The influence of particle shape (aspect ratio) on the intrinsic viscosity is investigated, taking three Czech kaolin products (floated kaolins) as paradigmatic examples. An average aspect ratio is obtained for each kaolin from a comparison of particle size measurements using sedimentation and laser diffraction. The intrinsic viscosity is obtained by a multistep procedure: firstly, flow curves are recorded for each kaolin with the optimum deflocculant concentration, secondly, the (apparent) relative viscosities read off from the flow curves are plotted against the kaolin volume fraction and, thirdly, these data are fitted using the Krieger relation to obtain the intrinsic viscosity in the asymptotic dilute limit. It is shown that the data determined with the method proposed are within the Jeffery and Brenner bounds and that an average aspect ratio of about 20 (17-22) results in an intrinsic viscosity of about 10 (7-13), compared to 2.5 for spherical particles. Although currently th e measurement precision is not suffi cient to seriously assess the influence of Brownian motion, the method can principally be used to predict the intrinsic viscosity when the average aspect ratio of the system (and its particle size distribution) is known, and vice versa., Eva Gregorová, Willi Pabst and Jean-Baptiste Bouchet., and Obsahuje bibliografické odkazy
An ethanol vapor concentration of 1.6 mmol/l was used to test the diurnal variations of the olfactory response in two groups of snails, which were adapted to different light-dark cycles. The results revealed that the olfactory sensitivity to stimulation with ethanol was significantly increased during the day-time, which corresponds to the scotophase of the light-dark cycle, to which the animals had been adapted (c2-test, P < 0.01)., M. Voss, C. Büchert, C. Missfelder., and Obsahuje bibliografii
PPAR-α agonists improve insulin sensitivity in rodent models of obesity/insulin resistance, but their effects on insulin sensitivity in humans are less clear. We measured insulin sensitivity by hyperinsulinemic-isoglycemic clamp in 10 obese females with type 2 diabetes before and after three months of treatment with PPAR-α agonist fenofibrate and studied the possible role of the changes in endocrine function of adipose tissue in the metabolic effects of fenofibrate. At baseline, body mass index, serum glucose, triglycerides, glycated hemoglobin and atherogenic index were significantly elevated in obese women with type 2 diabetes, while serum HDL cholesterol and adiponectin concentrations were significantly lower than in the control group (n=10). No differences were found in serum resistin levels between obese and control group. Fenofibrate treatment decreased serum triglyceride concentrations, while both blood glucose and glycated hemoglobin increased after three months of fenofibrate administration. Serum adiponectin or resistin concentrations were not significantly affected by fenofibrate treatment. All parameters of insulin sensitivity as measured by hyperinsulinemic-isoglycemic clamp were significantly lower in an obese diabetic group compared to the control group before treatment and were not affected by fenofibrate administration. We conclude that administration of PPAR-α agonist fenofibrate for three months did not significantly affect insulin sensitivity or resistin and adiponectin concentrations in obese subjects with type 2 diabetes mellitus. The lack of insulin-sensitizing effects of fenofibrate in humans relative to rodents could be due to a generally lower PPAR-α expression in human liver and muscle., K. Anderlová, R. Doležalová, J. Housová, L. Bošanská, D. Haluzíková, J. Křemen, J. Škrha, M. Haluzík., and Obsahuje bibliografii a bibiografické odkazy
In Lepidoptera, larval dietary experience of volatile cues can induce adult preference for these cues. However, such induction may require several generations, depending in part on the degree of specialization of the insects. In a previous study, using species of noctuid stem borers with different diet breadths, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and monophagous Busseola nairobica, it was shown that in S. nonagrioides, one generation was enough to induce a preference for vanillin in the resulting gravid females, whereas even two generations failed to induce a response in adults of Busseola spp. In this study, we checked whether a higher number of generations of exposure to a vanillin-enriched medium could induce a significant olfactory preference for this medium in the species B. fusca and B. nairobica, which have narrower host-plant utilization ranges than S. nonagrioides. Larvae were reared to the adult stage on an artificial diet enriched with vanillin for periods of from 2 to 7 or 8 generations, followed by two-choice tests on gravid females using a Y-tube olfactometer. The results showed different responses according to the species: for the oligophagous B. fusca, there was no significant effect of the conditioning, while a significant preference for the odours emitted by this new vanillin-enriched diet was recorded for the polyphagous S. nonagrioides and monophagous B. nairobica, but after different numbers of generations. In conclusion, different diet breadths seem to be associated with different levels of plasticity in the odour preference of adults. The implication of this result for insects' adaptability in a changing landscape is discussed., Christophe Petit, Peter Ahuya, Bruno Le Ru, Laure Kaiser-Arnauld, Myriam Harry, Paul-André Calatayud., and Obsahuje bibliografii
The vault in Vladislav Hall is a structural masterpiece of great historical value. Its structural analysis revealed that the permanent load exerted by its self weight is uniformly transmitted into the vaults and ribs without any potential crack appearance. The topical issue, however, is its response to temperature changes with respect to actual effects. Computations show that temperature changes may cause problems., Petr Fajman, Jiří Máca and Pavel Beran., and Obsahuje bibliografii
Urban gardens can harbour a high diversity of insects, which are critically important components of urban ecosystems. In this work, we investigate the richness and diversity of a major taxon of economic and ecological importance, the aphids (Hemiptera: Aphididae), and their main insect predators, the hoverflies (Diptera: Syrphidae) and ladybirds (Coleoptera: Coccinellidae), in urban gardens. We examined how variation in environmental factors associated with urbanisation (garden host plant abundance, garden plant richness, garden size, proportion of impervious surfaces in the surrounding area) directly and indirectly (via prey and predator abundance) influence the local diversity and abundance of aphids, ladybirds, and hoverflies. Sixty-seven domestic gardens located in southern England were surveyed during the peak period of aphid abundance, and the numbers and identity of aphids and their predators were recorded. We observed 45 aphid species (179917 individuals in total), 15 hoverfly species (494 individuals) and 8 ladybird species (173 individuals). We found that aphid species richness and abundance were positively associated with utilised host plant abundance and garden plant species richness. Hoverfly abundance was positively correlated with garden plant richness. The abundance of ladybirds was positively correlated with aphid abundance and garden plant species richness, and negatively associated to the proportion of impervious surfaces in the surrounding environment. The difference in responses between the two major taxa of aphid predators may reflect differences in their behaviour and natural history. Our results indicate that overall increases in urban land cover are not favourable for ladybirds as a group, and that fine scale habitat variables that are determined by garden owners have the potential to greatly affect the diversity of aphids and their primary predators., Elise A. Rocha, Estevão N.F. Souza, Lewis A.D. Bleakley, Christopher Burley, Jade L. Mott, Gloria Rue-Glutting, Mark D.E. Fellowes., and Obsahuje bibliografii
Old-age pension savings is a system functionally linked to the general pension insurance scheme, which focuses on the capitalization of savings accumulated by the saver in their personal pension account. From the administrative-procedural point of view, the pre-contractual part of the pay-out phase of this system is built on the Central Information Bidding System (CIBS), which is thus an important and systemic element of old-age pension savings. The present contribution analyses the tasks and objectives of this information system in the pay-out phase of pensions and, at the same time, asks the question whether it fulfils the functions of current modern information systems and if it thus assists in securing the constitutional right of a natural person to adequate material security in old age or, on the contrary, if it is only an information system that duplicates the rules and approaches introduced by the legislation providing for the method of the savings in the Slovak pension model (by the individualisation of saving with a low economic guarantee) and especially in the process of concluding a contract on the pension insurance that does not support the implementation of the constitutional law in a serious way., Miloš Lacko., and Obsahuje bibliografické odkazy