The present study was aimed to evaluate the mechanisms involved in the vasorelaxant effects of red wine polyphenol compounds (RWPC) in small mesenteric rat arteries. RWPC produce relaxation in small mesenteric arteries. This relaxant effect was abolished by endothelial denudation, NO-synthase blockade with L-NAME and partial depolarization with KCl or L-NAME plus KCl. Incubation with the reactive oxygen species scavenger, superoxide dismutase (SOD) plus catalase, or inhibition of NAD(P)H-dependent oxidoreductases with diphenyleneiodonium also inhibited RWPC induced vascular relaxation. Application of RWPC elicited a transient increase in intracellular calcium concentration ([Ca2+]i) in bovine aortic endothelial cells (BAEC), which was attenuated by a mixture of SOD and catalase. Incubation of BAEC with RWPC increased the SOD inhibitable production of O2-. These results suggest the involvement of O2- in the [Ca2+]i increase evoked by RWPC, leading to the activation of enzymes involved in the release of endothelial relaxant factors and subsequent vasodilatation of resistance arteries.
The aim of the present study was to test the hypothesis that short-winged (brachypterous) and long-winged (macropterous) adult males of a flightless bug Pyrrhocoris apterus differ in fertilization success. For this purpose, 5, 10 and 28 days old brachypterous and macropterous males were mated for the same period of time with reproductively active 5 days old brachypterous females. The average hatchability of five egg batches of these females was used as a measure of the fertilization success of the males. The results revealed significantly higher hatchability of the eggs laid by females that copulated with 5 or 10 days old brachypterous males than with same-aged macropterous males. In contrast, the average hatchability of eggs of females that copulated with 28 days old brachypterous males was significantly lower than of those mated with same-aged macropterous males. It is the first report of wing morph- and age-related differences in fertilization success of males in insects with a non-functional wing-polymorphism. The possible relationship between wing- and age-related differential fertilization and the mating success of P. apterus males, and differences in the amount of secretion transferred from their accessory glands into the reproductive tract of females during copulation, is discussed.
In Thailand, Anopheles (Cellia) epiroticus Linton et Harbach (Diptera: Culicidae) is the secondary vector of human malaria along coastal regions. While there are some studies of phenotypic variability and population structure of A. epiroticus, more information on morphological variation would enhance epidemiological understanding of medically important mosquito vectors. This research examined morphological variation at three different distances from coastlines of Samut Songkhram Province, Thailand, using landmark-based geometric morphometrics. Wing shape of A. epiroticus was significantly different in the area 0.2 km away from the sea compared to areas 2 and 4 km away from the sea (p < 0.05). Phenotypic variability in wing shape is associated with distance from the sea. Morphological variations in the area closest to the sea were most pronounced, showing a relationship between A. epiroticus and the ecosystem that affects wing geometry. These results provide important information to understand morphological variation of A. epiroticus in coastal areas., Tanawat Chaiphongpachara and Sedthapong Laojun., and Obsahuje bibliografii
Patterns of daily activity and the factors affecting it were studied in an invading Mediterranean population of American mink, Neovison vison, radiotracked in the northeast of Spain during the post breeding season (winter – half year). We distinguished between local activity, defined as active behaviour without spatial displacement, locomotion activity as active locomotion behaviour while foraging or travelling, and inactivity. We studied the effect of sex, age, daylight (nocturnal or diurnal), month, river flow and average rainfall on the activity of eight males and three females. Male mink presented more locomotion activity than females and subadult mink had more locomotion activity than adult mink. Average rainfall per day had a negative effect on locomotion, while daylight had no effect on either total activity or locomotion activity. Studied mink spent most of their time inactive in-den. These results are accordance with the patterns of activity shown by other native and invasive populations.
Overwintering insects must avoid injury and death from the freezing of tissues and from metabolic disruptions associated with exposure to low, non-freezing temperatures. The winter climates of the world are classified in relation to insect overwintering on the basis of their minimum temperatures and the duration of the winter (when temperatures are below the thermal range for activity and development). Outside the Tropical Wet zone, the severity of exposure to cold (temperature, snowfall, duration of exposure, predictability, variability) can vary from a few days at 0°C to months below -20°C with extremes as low as -60°C. The severity of the temperature exposure may be ameliorated by the selection by insects of overwintering sites (exposed, partly-exposed, protected). The relationships among overwintering habitats, the minimum winter temperature in climatic zones, and the supercooling points (SCP) of over 350 terrestrial insects from published reports were examined. Variability in the SCP among insects within each climatic zone and habitat was wide. Among the freeze-susceptible species that overwintered in exposed or partly-protected habitats the SCP and the cold severity of climate were correlated. This was not the case for insects that overwintered in protected habitats. The SCP's of freeze-tolerant insects were generally higher than the freeze-susceptible insects, and the SCP's were not tightly linked with the cold severity of climatic zone. Insects, both freeze-susceptible and freeze-tolerant, overwintering in exposed habitats had lower SCP's than insects from habitats that offered some protection from ambient temperatures. Thirty-eight species had reports of SCP's for different geographical locations. Although there were occasionally differences in the SCP's, there was no consistent pattern of insects having lower SCP's when overwintering in colder habitats. The incidence of freeze-tolerance was higher in boreal and polar climatic zones than in climatic zones with warmer winters. Holometabola insects had a higher incidence of freeze-tolerance than hemimetabola insects. Suggestions for future research directions are outlined.
The winter diet of the great cormorant (Phalacrocorax carbo) was studied by means of examining regurgitated pellets, individual fish bones and fish remains collected from below the roosting trees in two sites on the River Vltava in Vyšší Brod and at Slapy Reservoir, Czech Republic, and by analysis of stomach contents of birds shot on the River Vltava in Prague. Using diagnostic bones (os pharyngeum, dentale, maxillare, praeoperculare) and own linear regression equations between measured dimension of the diagnostic bone and fish total length (LT), a total of 1152 fish of 22 species and 6 families were identified in the diet of great cormorants and their sizes were reconstructed. At all three localities on the main stream of the River Vltava, roach (Rutilus rutilus), bream (Abramis brama), bleak (Alburnus alburnus), European chub (Squalius cephalus), European perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus) made up at least 74.2 % of the cormorants’ diet. A great potential for fish stock losses was identified for the River Vltava at Vyšší Brod and in Prague where the loss of fish due to overwintering great cormorants was estimated to be 22 kg ha–1 and up to 79 kg ha–1 respectively, i.e. belonging among the highest ever published figures for fish withdrawal caused by great cormorants from any inland waters (carp fishponds excluded). Most probably, both great cormorants and anglers are responsible for the decrease in catches of brown trout (Salmo trutta m. fario) and grayling (Thymallus thymallus) from the River Vltava in Vyšší Brod.
The food composition of noctule bats (Nyctalus noctula) was investigated using droppings analyses methods (29 samples/ 322 pellets) over two winters (2001/2002 and 2002/2003) in ten urban and rural localities in Central Europe (Slovakia, Czech Republic). Two orders of arachnids (Araneida, Acarina) and nine orders of insects (Homoptera, Heteroptera, Psocoptera, Neuroptera, Coleoptera, Hymenoptera, Lepidoptera, Diptera, Siphonaptera) were identified in the droppings. The most important order in all samples was Lepidoptera (mean F = 53 %, mean V = 35 %), followed by Diptera (F = 38 %, V = 12 %), Coleoptera (F = 21 %, V = 9 %) and Araneida (F = 15 %, V = 3 %). Differences were found in the composition of the most important food components among two urban and one rural locality as well as in the portion of secondary components (hair, slime). Regarding seasonal changes in the food composition, three periods were identified in winter – the beginning (November – January), the middle (February) and the end of the season (March). Some seasonal trends could be identified in the Diptera and Coleoptera, with a decrease in frequency and volume in the middle of the winter. The most important food component (Lepidoptera) showed no seasonal trend over winter. The bats could hunt insects outside or collect them also very probably directly in the shelters.
Winter habitat use, niche breadth and overlap between the native and invasive species of medium sized predators, the red fox, pine marten and raccoon dog in particular, were studied in three landscapes with different habitat structure in Lithuania. Meadows were preferred by foxes but avoided by raccoon dogs and pine martens. Pine martens intensively used various forest habitats, whilst raccoon dogs tended to prefer swamps. The habitat niche breadth (Hurlbert’s standardized niche breadth) varied with respect to both the species and the study site. The habitat niche overlap was larger between raccoon dog and pine marten than that between raccoon dog and red fox. Our results suggest a low impact of the invasive raccoon dog on red fox and pine marten in studied landscapes.
Otter (Lutra lutra) diet was studied by analysing of 180 spraints and 29 partly consumed fish remains found in winter around fishponds in South Bohemia (Czech Republic). The proportion of fish found in spraints was 95.6% of all prey items, roach (Rutilus rutilus), topmouth gudgeon (Pseudorasbora parva) and common carp (Cyprinus carpio) being the most numerically abundant species with 37.3, 21.3 and 19.0% respectively. Carp dominated the diet bymass (47.8%), whilst roach and “other commercial fish species” (predatory and herbivorous fish, tench, Tinca tinca) formed 21.8 and 15.3% of total biomass, respectively. Small fish (< 200 mm) predominated in the diet and only 4.0% of all fish found in spraints exceeded 300 mm TL. Large fish remains were very scarce in spraints and were best recorded from uneaten prey remains. The partially eaten remains of carp, pike (Esox lucius) and common bream (Abramis brama) were found on banks or ice, but most (86%) were carp. The original length of carp corpses ranged between 283 and 530 mm TL, and the proportion of body mass consumed varied between 5.0 – 90.1%. The length of pike remains ranged from 386 to 754 mm TL, of which 84.0% of body mass on average was consumed by otters. The otter diet apparently reflects food availability in fishponds and supply channels. Small water basins with a high stock density can be vulnerable to serious damage especially during the winter period and at such places, where no better accessible source of food is available to otters. However, in many such places simple mitigation measures may be able to reduce otter predation.
The article investigates how the Holocaust distorted and exploited in Cold War debates on the example of genesis and reception of the book Ghetto Warschau. Tagebücher aus dem Chaos [Warsaw Ghetto: Diaries from Chaos]. The book is a translation of the essay Stosunki polsko-żydowskie w czasie drugiej wojny światowej [Polish-Jewish relations during the Second World War], written by the Jewish historian and creator of the underground archive of the Warsaw Ghetto Emanuel Ringelblum while hiding from the German Occupiers in Warsaw in 1944. Ringelblum addressed his essay to the Polish reader discussing the relation of Christian Poles and Polish Jews under German occupation based on his own experience and the material he had collected. It was originally published in several portions in the Bulletin of the Jewish Historical Institute, an early Holocaust Research Center based in Warsaw. The German translation was based on this publication and published in summer 1967 in a Stuttgart-based publishing house. However, the new title, introduced by its German editors, suggested it was Ringelblum’s diary. Above that the blurb and many footnotes highlighted the role of Poles as perpetrators in the Holocaust, while minimizing that of Germans. As the article shows, the book was prepared by the Göttinger Arbeitskreis ostdeutscher Wissenschaftler [Göttingen Working Group of Eastern German Scholars], a Think Tank with close ties to the German expellee community, campaigning for a revision of the Polish western border. Göttinger Arbeitskries used the book and earlier on excerpts of Ringelblum’s text for a smear-campaign in the West-German expellee press. Through the biased presentation and distorted context of the work these former Ostforschers sought to portrait Poles as eternal anti-Semites and the factual perpetrators of the mass murder of Polish and European Jews following their anti-Polish agenda. Polish nationalist within the ruling Polish United Workers Party in turn exploited the book and the campaign based on it, which coincided with the anti-Semitic campaign in Poland. Though the Institute was not involved in the publication of the German book, the Polish national communists accSome reform Communists who went into exile after the Soviet-led military intervention in Czechoslovakia, in August 1968, began to work in the Listy group led by Jiří Pelikán (1923-1999), a former Director of Czechoslovak Television, the publisher of the Rome-based exile bimonthly Listy, and, later, a Member of the European Parliament. In the search for political allies against Husák’s regime of ''normalization'' (the return to hard-line Communist rule), they tried to establish contact mainly with infl uential representatives of the West European Left. This article, however, examines an area of their involvement in exile, which has previously not received attention - namely, their efforts to develop contacts with Chinese Communists who in the period after August 1968 were vociferously speaking out at international forums and criticizing Soviet expansionism. The author demonstrates how the exiles tried to take advantage of this in order to strengthen their positions as members of the foreign socialist opposition to the normalization regime. When establishing these contacts, they could build particularly upon those that Pelikán had developed in China while working in the International Union of Students. In the second half of the 1970s his erstwhile Chinese colleagues, led by Hu Yaobang (1915-1989), rose to leading positions in the Party, thus creating considerable opportunities for the exiles to work with them. From China, they received continuous funding for their activities, while the Chinese were interested in the Czechoslovak attempt to reform state socialism in the late 1960s. The author acquaints the reader with visits by Listy ‘envoys’ to China, who acquainted their partners there with current developments in central Europe, including information about dissidents and the opposition movement. A special initiative as part of this collaboration was their attempt to get their own representatives involved in the Czech broadcasts of Radio Peking. Though they briefl y succeeded in this, their plan to infl uence the content of transmissions to Czechoslovakia, and thereby make it an information source for listeners which would provide an alternative to state-controlled Czechoslovak mass media, ultimately came to naught: members of the Listy group worked at Radio Peking only as language advisers for the Czech broadcasts. and Překlad: Blanka Medková