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241.
Anton Petrík Zuzana Dúbravcová Ivan Jarolímek Ján Kliment Jozef Šibík Milan Valachovič 《Biologia》2006,61(4):393-412
We present a syntaxonomic account of the communities of the alliances of Oxytropido-Elynion
Br.-Bl. 1949 and Festucion versicoloris
Krajina 1933 from Western Carpathians. Both alliances comprise naked-rush, cushion form and dwarf-shrub heath communities typical
of wind-exposed habitats occurring at the highest altitudes of the Tatra Mts. They represent a relic vegetation of the cold
stages of the Pleistocene (probably Late Glacial Maximum) and they can be classified within the class of Carici rupestris-Kobresietea bellardii
Ohba 1974. A set of relevés was subject to numerical-classification analysis. Floristics and ecology of the communities were characterised
and the relationships to similar syntaxa were discussed.
The Oxytropido-Elynion is restricted to the extreme ridge positions in the highest altitudes of the Belianske Tatry Mts. Five associations were
distinguished, such as the Pyrolo carpaticae-Salicetum reticulatae, the Festuco versicoloris-Oreochloetum distichae, the Festucetum versicoloris, the Oxytropido carpaticae-Elynetum myosuroides and the Drabo siliquosae-Festucetum versicoloris.
The Festucion versicoloris is limited to the mylonite zone of the alpine and subnival belt of the Vysoké Tatry and Západné Tatry Mts (and found as rare
in the Nízke Tatry Mts). The stands of these communities prefer terraces of steep rocky faces and cliffs and stabilised small-grained
screes below the cliffs. Within this alliance, three associations were described, including the Agrostio alpinae-Festucetum versicoloris, the Silenetum acaulis and the Salicetum kitaibelianae. 相似文献
242.
Musova Z Hedvicakova P Mohrmann M Tesarova M Krepelova A Zeman J Sedlacek Z 《Biochemical and biophysical research communications》2006,347(1):145-149
L1 elements are mammalian retrotransposons contributing to genome evolution and causing rare mutations in human. We describe a de novo insertion of an L1 element into the dystrophin gene resulting in skipping of exon 44 and causing Duchenne muscular dystrophy in a boy. The L1 element was rearranged due to the twin-priming mechanism, but contrary to all described L1 rearrangements the 5' region of the inverted L1 sequence ended within the poly(A) tail of the element. Furthermore, the target site for the insertion was located only 87 bp from the insertion site in another patient described previously. These findings can contribute to the understanding of the mechanisms of L1 element rearrangement, and may support the notion that some subregions of the human genome could be preferred targets for retroelements using the L1 enzymatic machinery. 相似文献
243.
Bencokova Z Kaufmann MR Pires IM Lecane PS Giaccia AJ Hammond EM 《Molecular and cellular biology》2009,29(2):526-537
The ATM kinase has previously been shown to respond to the DNA damage induced by reoxygenation following hypoxia by initiating a Chk 2-dependent cell cycle arrest in the G(2) phase. Here we show that ATM is both phosphorylated and active during exposure to hypoxia in the absence of DNA damage, detectable by either comet assay or 53BP1 focus formation. Hypoxia-induced activation of ATM correlates with oxygen concentrations low enough to cause a replication arrest and is entirely independent of hypoxia-inducible factor 1 status. In contrast to damage-activated ATM, hypoxia-activated ATM does not form nuclear foci but is instead diffuse throughout the nucleus. The hypoxia-induced activity of both ATM and the related kinase ATR is independent of NBS1 and MRE11, indicating that the MRN complex does not mediate the DNA damage response to hypoxia. However, the mediator MDC1 is required for efficient activation of Kap1 by hypoxia-induced ATM, indicating that similarly to the DNA damage response, there is a requirement for MDC1 to amplify the ATM response to hypoxia. However, under hypoxic conditions, MDC1 does not recruit BRCA1/53BP1 or RNF8 activity. Our findings clearly demonstrate that there are alternate mechanisms for activating ATM that are both stress-specific and independent of the presence of DNA breaks. 相似文献
244.
Ellenberg's indicator values (simple ordinal classes of plants with a similar realized ecological niche along a gradient) were tested to describe the changing environment and water resources recharge in the upper plateau of the Jizera Mountains. (Czech Republic). In the 1980s, the acid atmospheric deposition led to the decline and clear-cut of spruce plantations (Picea abies): Junco effusi-Calamagrostietum villosae became a new dominant community there. Ellenberg's indices for light (L), moisture (F), nitrogen (N) and acidity (R) were compared with hydrological parameters of a small catchment (soil water content, evapotranspiration, retention, stream-flow pH and nitrate content) in 1982–2008. Ellenberg's indicators F and L describe well the plant succession related to microclimate and hydrology at clear-cut sites. Also, the indices N and R follow trends in the atmospheric deposition and water quality; however, with lower sensitivity. Ellenberg's indices reflect the observed changes in water phenomena with a lag period of 3–10 years. 相似文献
245.
Nohrdent D Cattaneo C Gabriel P Ohlrogge S Poppa P Schmitt R Tutkuviene J Rizgeliene R Ratnayake M Obertová Z Ritz-Timme S 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》2010,68(1):101-109
Recruiting test persons is crucial in many scientific fields. The recognition of motivators or barriers to survey participation may support the design and recruitment strategy of future studies. The recruitment of under age test persons is very complex and sensitive. This paperpresents and analyses the experiences in recruitment of female juveniles (10-18 years old) in Germany, Italy and Lithuania within the context of an EU funded project concerning the extremely sensitive topic of "child pornography". The purpose of the project was to develop a method for age estimation of juveniles on photographs and videos. The faces of the test persons were photographed and anthropologically measured after an informed consent was signed by their parents and themselves. The analysis of the recruitment strategies and response rates revealed that culturally influenced factors played a significant role in the individual decision for or against a participation in the study. In all countries, the sensitive topic of child pornography had a great influence on the decision process. Many German parents agreed especially in light of this topic while in Italy and Lithuania the word "child pornography" triggered a very negative response. In Germany, the anthropological investigation of the faces provoked negative associations with the anthropometric surveys in the Third Reich. Social and political climate were further relevant factors for decision-making especially in Lithuania. The "top-down" principle of recruitment proved to be very effective for this kind of study. The authorities of headmasters, scientists and institutions positively influenced the decisions of the parents. 相似文献
246.
Kalina Danova Eva Čellárová Anna Macková Zuzana Daxnerová Veneta Kapchina-Toteva 《In vitro cellular & developmental biology. Plant》2010,46(5):422-429
The Balkan endemic species, Hypericum rumeliacum, Guttiferae was introduced in vitro for the first time with the aim to study the type of morphogenetic response to plant growth regulators and ability to produce
phenolics and flavonoid compounds. The morphoregulatory effect of 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphtaleneacetic
acid (NAA), 6-benzyladenine (BA) and combination of BA with NAA in Murashige–Skoog's basal medium on leaf lamina, internode
stem segment, stem node and root cuttings was studied. Histological analysis of the structures regenerated from the primary
explants proved the presence of both, embryoids and meristemoids. The node explants cultivated on BA-supplemented medium were
the most favourable for regeneration through meristemoids. Therefore a double-stage culture approach, allowing an effective
multiplication of large quantities of plant shoots in vitro along with maintenance of the biosynthetic capacity of the culture was developed. It comprised one subculture of three-nodal
stem explants derived from the stock shoot cultures on MS medium supplemented with 0.2 mg/l BA followed by subculture of the
induced multiple shoots on cytokinin-free MS medium. Determination of the total phenolics and flavonoids showed that the decrease
of the levels of these secondary metabolites is transitional, as the exclusionof BA from the medium resulted in an increase
of their total content. 相似文献
247.
Milan Gryndler Zuzana Egertová Lucie Soukupová Hana Gryndlerová Jan Borovička Hana Hršelová 《Mycological Progress》2010,9(1):27-36
Seventeen isolates of Entoloma clypeatum, a fungus associated with rosaceous woody plants and suspected to act as a root pathogen, were obtained from fruit-bodies
collected at 7 localities in the Czech Republic. The fungus grew best on the medium supplied with cellobiose. The growth of
E. clypeatum was inhibited by fungicide preparation Ridomil Gold MZ 68WP. A part of the LSU rRNA gene of 11 selected isolates was sequenced
and two reverse primers recognizing the sequence motifs in the LSU rRNA gene of E. clypeatum and other related species associated with rosaceous woody plants were designed. One of these primers, NL4EC2, showed high
specificity towards DNA of Entoloma spp. of interest and may be used for detection of these organisms in soil, in roots or in the substrate where the fruit trees
are cultivated. The results of in vitro inoculation experiment suggest a resistance of roots of young Prunus domestica plants to colonization by Entoloma clypeatum, and the fungus could be detected only in the surrounding substrate. We were able to detect Entoloma spp. in soil and in roots of Prunus avium but only if the fructification of the fungus occurred at the locality. The method is robust towards the false positive detection
caused by nonspecific amplification of DNA of other soil microorganisms. 相似文献
248.
Irina N. Krasnova Zuzana Justinova Bruce Ladenheim Subramaniam Jayanthi Michael T. McCoy Chanel Barnes John E. Warner Steven R. Goldberg Jean Lud Cadet 《PloS one》2010,5(1)
Methamphetamine (meth) is an illicit psychostimulant that is abused throughout the world. Repeated passive injections of the drug given in a single day or over a few days cause significant and long-term depletion of dopamine and serotonin in the mammalian brain. Because meth self-administration may better mimic some aspects of human drug-taking behaviors, we examined to what extent this pattern of drug treatment might also result in damage to monoaminergic systems in the brain. Rats were allowed to intravenously self-administer meth (yoked control rats received vehicle) 15 hours per day for 8 days before being euthanized at either 24 hours or at 7 and 14 days after cessation of drug taking. Meth self-administration by the rats was associated with a progressive escalation of daily drug intake to 14 mg/kg per day. Animals that self-administered meth exhibited dose-dependent decreases in striatal dopamine levels during the period of observation. In addition, there were significant reductions in the levels of striatal dopamine transporter and tyrosine hydroxylase proteins. There were also significant decreases in the levels of dopamine, dopamine transporter, and tyrosine hydroxylase in the cortex. In contrast, meth self-administration caused only transient decreases in norepinephrine and serotonin levels in the two brain regions, with these values returning to normal at seven days after cessation of drug taking. Importantly, meth self-administration was associated with significant dose-dependent increases in glial fibrillary acidic protein in both striatum and cortex, with these changes being of greater magnitude in the striatum. These results suggest that meth self-administration by rats is associated with long-term biochemical changes that are reminiscent of those observed in post-mortem brain tissues of chronic meth abusers. 相似文献
249.
250.
Tanja Grimm Roswitha Skrabala Zuzana Chovanová Jana Muchová Katarína Sumegová Anna Liptáková Zdeňka Ďuračková Petra Högger 《BMC clinical pharmacology》2006,6(1):1-12