280 research outputs found
Cohomology theories on locally conformal symplectic manifolds
In this note we introduce primitive cohomology groups of locally conformal
symplectic manifolds . We study the relation between
the primitive cohomology groups and the Lichnerowicz-Novikov cohomology groups
of , using and extending the technique of spectral
sequences developed by Di Pietro and Vinogradov for symplectic manifolds. We
discuss related results by many peoples, e.g. Bouche, Lychagin, Rumin,
Tseng-Yau, in light of our spectral sequences. We calculate the primitive
cohomology groups of a -dimensional locally conformal symplectic
nilmanifold as well as those of a l.c.s. solvmanifold. We show that the l.c.s.
solvmanifold is a mapping torus of a contactomorphism, which is not isotopic to
the identity.Comment: 43 pages, improved presentation, final versio
Terapijska i neuroprotektivna djelotvornost profilakse i primjene protuotrova u liječenju akutnog otrovanja tabunom odnosno somanom s posebnim osvrtom na profilaksu PANPAL-om
A good knowledge of the basic mechanisms of acute toxicity of organophosphorus compounds has lead to the development of specific antidotes able to counteract their acute toxic effects. Unfortunately, there are still some highly toxic organophosphorus compounds, called nerve agents, that are resistant to standard antidotal treatment. Relatively unsatisfactory antidotal treatment of acute poisonings with some nerve agents has prompted studies of pretreatment possibilities that would increase the resistance of organisms exposed to nerve agents. Current protection against nerve agent poisoning is pyridostigmine, but its prophylactic efficacy is rather limited. To increase the effectiveness of pharmacological pretreatment of soman or tabun poisoning, a prophylactic mixture called PANPAL and consisting of pyridostigmine and two anticholinergic drugs – benactyzine and trihexyphenidyle was developed, produced and introduced into the Czech Army to protect soldiers against nerve agent exposure. This review describes the evaluation of the potency of PANPAL to counteract acute soman or tabun poisoning and to increase the therapeutic and neuroprotective efficacy of current post-exposure antidotal treatment in comparison with pyridostigmine given alone as pretreatment.Uvid u osnovne mehanizme akutnog otrovanja organofosfornim spojevima omogućio je razvoj specifičnih protuotrova koji su u stanju poništiti akutno toksično djelovanje otrova. Nažalost još postoje veoma toksični organofosforni spojevi poznati kao živčani otrovi, a koji su otporni na liječenje standardnim protuotrovima. Relativno slabi rezultati dosadašnjeg liječenja akutnog otrovanja živčanim otrovima potaknuli su istraživanje mogućnosti profilakse koja bi povećala otpornost izloženih organizama. Dosada se u te svrhe rabio piridostigmin, ali je njegovo profilaktičko djelovanje prilično ograničeno. Kako bi se povećala djelotvornost profilakse protiv trovanja somanom odnosno tabunom, u oružanim snagama Češke Republike razvijena je kombinirana profilaksa pod nazivom PANPAL, a koja obuhvaća piridostigmin i dva antikolinergika, benaktizin i triheksifenidil. Svrha joj je bolje zaštititi vojnike kod izlaganja živčanim otrovima. Ovaj pregledni rad opisuje testiranje djelotvornosti PANPAL-a protiv akutnog otrovanja somanom odnosno tabunom te poboljšanje terapijskoga i neuroprotektivnog djelovanja kod akutnog otrovanja tabunom odnosno somanom u odnosu na isključivu primjenu piridostigmina kao uobičajene profilakse kod trovanja živčanim agensima
The art of science: interview with Professor John Archibald Wheeler
During the conference on the methods of differential geometry in physics in
Warsaw in June 1976, Professor Wheeler gave an interview for the Czechoslovak
Journal of Physics A. After Professor Wheeler authorized the English version in
January 1977, the Czech translation was published in \v{C}eskoslovensk\'y
\v{c}asopis pro fyziku A (1978) and soon afterwards the Polish translation
appeared in Postepy fizyky. After John Wheeler's recent death it occurred to me
that it would now be appropriate to publish the original interview from 1976 so
that it would not be lost to English readers; and so, despite being more than
30 years old, the interview appeared in the special issue on quantum gravity of
"General Relativity and Gravitation" dedicated to the memory of J. A. Wheeler.
John Wheeler would now surely add more about black holes in nuclei of
galaxies, not mentioning just Cygnus X-1, when discussing cosmology he would
undoubtedly address the problem of dark energy etc. However, in the
conversation about Einstein and Bohr, about the need for choosing appropriate
names, or about the relation of science and philosophy and art, he would
probably give answers as he did more than 30 years ago
First records of Parergodrilus heideri (“Polychaeta”: Parergodrilidae) and Hrabeiella periglandulata (“Polychaeta”: Hrabeiellidae) from Slovakia and new records of both species from Czechia
In the course of a study on microannelids of spring fens and adjacent grasslands in the Western Carpathians (within Czechia and Slovakia), conducted in spring and autumn of 2015 and 2016, the two terrestrial, soil-dwelling polychaetes Parergodrilus heideri and Hrabeiella periglandulata were recorded for the first time in Slovakia at six sites and one site, respectively. The find of P. heideri in the eastern part of Slovakia represents the second eastern-most published record within its known European range (only a recent record from Estonia lies further in the east). Within Czechia, P. heideri (hitherto known from a single site in the north of Bohemia) was found at four sites and H. periglandulata at three sites, all in north-eastern Moravia close to the Polish and Slovak borders
Use of Impact Penetrometer to Determine Changes in Soil Compactness After Entracon Sioux EH30 Timber Harvesting
Wood harvesting with the use of wheeled harvesters is now common in Polish and Czech
forests. While moving in the forest, the wheels of these machines affect the forest soil and the
extent of this impact is interesting. The paper presents the results of measurements of the
changes that occur in the soil on the operational trails after the timber harvesting using the
Entracon Sioux EH30 thinning harvester. The measurements were taken on fragments of three
operational trails, in and between the ruts and at a distance of 1.0 m off the trail. An impact
penetrometer was used to measure the penetration resistance, soil samples were collected to
determine the bulk density and moisture content, and soil deformations on the trail were
measured with a profile meter. Unit pressures exerted by harvester wheels on the ground were
determined. It was shown that in the places where the harvester wheels pass, even of a small
weight (5.73 tons, 8 wheels) and with unit pressures of the wheels on the ground <50 kPa,
changes in soil parameters occurred. A statistically significant increase in penetration resistance
in relation to the control occurred at a depth of up to 35 cm, while at a depth of up to
5 cm the increase was more than 2-fold. There was also a slight decrease in soil moisture
content (up to 7.9%) and an increase (up to 8.4%) in bulk density in the ruts, while rut depths
were small and reached 4 cm. As it was shown, the impact penetrometer, simple in design,
which was assumed to be used for measurements, and which is not used in this type of research
in forestry, despite its limitations, can be used to determine the compactness of the soil and its
changes resulting from machine work
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