Methods of Assessment and Clinical Relevance of QT Dynamics

The dependence on heart rate of the QT interval has been investigated for many years and several mathematical formulae have been proposed to describe the QT interval/heart rate (or QT interval/RR interval) relationship. While the most popular is Bazett’s formula, it overcorrects the QT interval at high heart rates and under-corrects it at slow heart rates. This formulae and many others similar ones, do not accurately describe the natural behaviour of the QT interval. The QT interval/RR interval relationship is generally described as QT dynamics. In recent years, several methods of its assessment have been proposed, the most popular of which is linear regression. An increased steepness of the linear QT/RR slope correlates with the risk of arrhythmic death following myocardial infarction. It has also been demonstrated that the QT interval adapts to heart rate changes with a delay (QT hysteresis) and that QT dynamics parameters vary over time. New methods of QT dynamics assessment that take into account these phenomena have been proposed. Using these methods, changes in QT dynamics have been observed in patients with advanced heart failure, and during morning hours in patients with ischemic heart disease and history of cardiac arrest. The assessment of QT dynamics is a new and promising tool for identifying patients at increased risk of arrhythmic events and for studying the effect of drugs on ventricular repolarisation

How do landscape structure, management and habitat quality drive the colonization of habitat patches by the Dryad Butterfly (Lepidoptera : Satyrinae) in fragmented grassland?

Most studies dealing with species distribution patterns on fragmented landscapes focus on the characteristics of habitat patches that influence local occurrence and abundance, but they tend to neglect the question of what drives colonization of previously unoccupied patches. In a study of the dryad butterfly, we combined classical approaches derived from metapopulation theory and landscape ecology to investigate the factors driving colonization from a recent refugium. In three consecutive transect surveys, we recorded the presence and numbers of imagos in 27 patches of xerothermic grassland and 26 patches of wet meadow. Among the predictors affecting the occurrence and abundance of the dryad, we considered environmental variables reflecting (i) habitat patch quality (e.g., goldenrod cover, shrub density, vegetation height); (ii) factors associated with habitat spatial structure (patch size, patch isolation and fragmentation); and (iii) features of patch surroundings (100-m buffers around patches) that potentially pose barriers or provide corridors. Patch colonization by the dryad was strongly limited by the distance from the species refugium in the region; there was a slight positive effect of shrub density in this respect. Butterfly abundance increased in smaller and more fragmented habitat patches; it was negatively impacted by invasive goldenrod cover, and positively influenced by the density of watercourses in patch surroundings. Nectar plant availability was positively related to species abundance in xerothermic grassland, while in wet meadow the effect was the reverse. We conclude that dryad colonization of our study area is very recent, since the most important factor limiting colonization was distance from the refugium, while the habitat quality of target patches had less relevance. In order to preserve the species, conservation managers should focus on enhancing the quality of large patches and should also direct their efforts on smaller and more fragmented ones, including those with relatively low resource availability, because such habitat fragments have an important role to play for specialist species

Resource use in two contrasting habitat types raises different challenges for the conservation of the dryad butterfly Minois dryas

The suitability of any location for a given species is determined by the available resources. However, there are many species that occur in more than one habitat type and their successful conservation may be particularly difficult. The dryad Minois dryas, a locally endangered butterfly, occurs in two contrasting habitats-xerothemic and wet grasslands. We investigated the influence of various habitat characteristics, such as vegetation height, grass cover, proximity of shrubs, plant species composition, Ellenberg indices of trophic and microclimatic conditions, on the microhabitat selection by the species. The nectaring of randomly selected butterflies was observed and habitat characteristics were compared at random points within the meadow and at the butterfly’s nectaring and resting places. The butterflies generally preferred to stay close to shrubs and avoided invasive goldenrods. Thermal conditions and the availability of nectar plants were the factors limiting the dryad’s use of wet grassland. In xerothermic habitats grass cover affected the distribution of butterflies. Concerning the availability of larval host plants, wet meadows proved potentially more favourable, whereas nectar resources for adults were more abundant in xerothermic grasslands. Based on our findings, conservation strategies for this butterfly must differ in the two habitats. Rotational mowing in xerothermic grasslands and the removal of invasive goldenrods in wet grasslands are the recommended actions. At a larger spatial scale, a habitat mosaic composed of xerothermic and wet grasslands in close proximity would seem to be the most suitable areas for the conservation of the dryad

All natural habitat edges matter equally for endangered Maculinea butterflies

An obvious consequence of habitat fragmentation is an increasing role of habitat edges for species survival. Recently it has been suggested that the endangered butterfly Maculinea nausithous prefers forested edges of its meadow habitats. However, the prevalence of forests in the study area used for this analysis makes it impossible to distinguish whether the effect detected is a genuine preference for forest edges or a preference for any natural patch edges as opposed to patch interiors. We investigated habitat selection by Maculinea nausithous and Maculinea teleius occurring sympatrically at five habitat patches surrounded by mosaic landscape. Butterfly capture positions were marked with GPS and subsequently analysed with GIS software. Both species avoided the interiors of their patches and concentrated in the edge zone, but these preferences were visible only at three larger patches exceeding 1 ha in area. Among different types of edges those bordering densely built-up areas were avoided, whereas all natural edges (adjacent to forests, reeds or grasslands) were similarly used. We hypothesise that preferences towards natural patch edges, regardless of their type, can be explained by the spatial interactions between Maculinea butterflies and Myrmica ants they parasitise. Patch surroundings constitute refuge space for the ants, and hence their densities may be expected to be higher near patch edges. Our findings indicate the importance of patch surroundings for the persistence of Maculinea populations. Regretfully, current legal framework makes it difficult to protect patch surroundings, where neither priority species nor their habitats occur

Analysis of the Accuracy of Prediction of the Celestial Pole Motion

VLBI observations carried out by global networks provide the most accurate values of the precession-nutation angles determining the position of the celestial pole; as a rule, these results become available two to four weeks after the observations. Therefore, numerous applications, such as satellite navigation systems, operational determination of Universal Time, and space navigation, use predictions of the coordinates of the celestial pole. In connection with this, the accuracy of predictions of the precession- nutation angles based on observational data obtained over the last three years is analyzed for the first time, using three empiric nutation models---namely, those developed at the US Naval Observatory, the Paris Observatory, and the Pulkovo Observatory. This analysis shows that the last model has the best of accuracy in predicting the coordinates of the celestial pole. The rms error for a one-month prediction proposed by this model is below 100 microarcsecond.Comment: 13 p

"Bo na tym świecie Śmierć wszystko zmiecie..." : tragiczny wymiar maskarad w wybranych utworach literatury romantyzmu

According to Mikhail Bakhtin, in Romanticism the ludic element of the mask blurs. The mask gains a number of new meanings, at the same time losing its associations with rebirth, characteristic of folk culture, and acquiring a new, gloomy expression. This article traces this gloomy and tragic aspect of masquerades as presented in Romanic literature. The analysis is based on three texts: Mikhail Lermontov’s Masquerade, Juliusz Słowacki’s Jan Bielecki and Antoni Malczewski’s Maria. The motif of masquerade, present in all three works, is discussed both from the perspective of the theory of literature and with reference to the cultural contexts of the mask

Alchemia pod znakiem Saturna : tragizm i melancholia w "Sędziwoju" Józefa Bohdana Dziekońskiego

In the novel Sędziwój by Józef Bohdan Dziekoński, alchemists are shown as people strongly connected with the night. In accordance with Romantic poetics, the night makes it possible for the human being to reach beyond the limitations of rational thinking, traditionally associated with the day. Alchemists’ way of life, different from the widely adopted one, contributes to their isolation from the society – a situation which they themselves treat as one of the factors indispensable for the development of their skill. In Dziekoński’s view, alchemists are melancholic geniuses, forever alone, consciously sinking in despair and aware of the fact that happiness is one of the greatest obstacles on the way to excellence. The real value of the protagonists’ life consists in the determination and readiness to sacrifice everything to achieve their set goals rather than in any tangible effects of their work. The sacrifice of earthly life is the proof of reaching the height of humanity, which in the novel is symbolically expressed as possessing the secret of the philosopher’s stone

Oświeceniowa krytyka zabobonu : "Wieczory badeńskie" Józefa Maksymiliana Ossolińskiego

The article aims to analyze Wieczory badeńskie (Baden Evenings) by Józef Maksymilian Ossoliński as a work representative of the Enlightenment struggle with superstitions. Ideas typical to the Enlightenment are analyzed with regards to the motifs that refer to the exaggerated fear of the deceased found in a collection by Ossoliński. Analyzed are the methods by means of which Ossoliński mocks a superstitious way of thinking that was typical to that age. Particular works, whose echoes are found in the text, are examined in relation to the Polish Enlightenment culture as well as in further European contexts