The littoral zone of shallow water bodies in the Czech Republic has been studied quite consistently at several fishponds. The use of algae, especially diatoms, for the monitoring of the state of lotic freshwater also has a long tradition. The main objective of the presented paper is to validate the feasibility of the use of littoral periphyton comunities for the biomonitoring of standing waters. At the investigated sites, littoral periphytic diatoms were studied together with selected enviromental variables (pH, conductivity, nutrients – especially total phosphorus) on three types of natural substrates (epilithon, epiphyton, epipelon). The evaluation of the diatom community was performed on the basis of the checklists of algal indicator species published by authors from the Czech Republic, Austria and the Netherlands. The data were subjected to statistical software NCCS 2000 (GLM Anova and ``Ward's minimum'' variance cluster analysis). Littoral periphytic diatoms appear to be good indicators of the fishpond water quality. The selected substrates show non-significant differences therefore the average values from all substrates were used. The best indicatory system for evaluation of Czech fishponds was van Dam's index.
The seasonal history and phenology of an indigenous field population ofTyphlodromus pyri Scheuten inhabiting a commercial apple orchard in South Bohemia are described. Data on population dynamics, number of generations, feeding, mating and reproductive habits as well as seasonal distribution within the apple tree canopy are discussed. Recommendations for mass retrieval ofT. pyri from apple orchards, their transfer to, and release in other orchards, are given. The conclusions and recommendations can be used for improving integrated pest management strategies in commercial apple orchards. 相似文献
Denervated fast-twitch rabbit muscles were progressively losing their fresh weight and the yield of sarcotubular protein was increasing. The activity of Ca(2+)-ATPase was affected but very slightly, the basal Mg(2+)-ATPase and the Mg(2+)-ATPase/Ca(2+)-ATPase ratio however increased together with a simultaneous depression of the membrane-bound acetylcholinesterase activity. We did not observe any differences in density properties of sarcotubular fractions between control and denervated muscle. However, a relative enrichment in SM and H fraction could be seen after denervation with small changes in the content of the Ca(2+)-pump protein, increased levels of calsequestrin and cholesterol, mostly in the heavy and the SM fraction. After denervation the binding sites for 3H-PN-200-110 did not show any changes in receptor affinity, but the number of putative Ca(2+)-channels increased twice along with a depression of 3H-ouabain binding sites. We suggest that the denervation of fast-twitch muscle leads to the hypertrophy of the junctional sarcoplasmic reticulum and the T-system. Changes in the cholesterol content, in the number of putative Ca(2+)-channels and in Na+, K(+)-ATPase can affect the muscle contraction. 相似文献
MicromelesDecaisne emend.Koehne (Rosaceae, Maloideae) is shown to be generically distinct fromSorbus L. emend.Crantz. Problems in the taxonomy of the genus are reviewed. The genus appears to be most closely related toRaphiolepisLindl. but is readily distinguished by a constant set of characters. Both genera may be derived fromSorbus L. emend.Crantz subg.AriaPers. Analysis of morphological characters is provided. A survey for flavonoids revealed the presence of vitexin and/or luteolin 7-O-glucoside in some members of the genus in a pattern similar to that found in certain Asian species ofSorbus. There are also brief taxonomic notes on some of the species which were examined. 相似文献
13C-N.m.r. spectra of all possible 1,6:2,3- and 1,6:3,4-dianhydro-β-D-hexo-pyranoses and their O-acetyl and deoxy derivatives are presented. Relations between chemical shifts of certain carbon atoms and the structure of the dianhydrides are outlined, and their application in structural analysis is discussed. Inversion of configuration of the oxirane ring from the endo to the exo position is associated with typical upfield-shifts for oxirane-ring carbon atoms C-2 or C-4, respectively. Possible inter-relationships between 13C-chemical shifts and steric and polar interactions in the dianhydro derivatives are discussed. 相似文献
Naturalistic grazing by large herbivores is an increasingly practiced way of managing habitats with conservational value. It has the potential to restore and enhance biodiversity, creating self-sustainable environments vital for organisms requiring regular disturbances to moderate and/or reverse successional changes. European bison, Exmoor pony, and Tauros cattle were introduced in 2015 to a former military training area in Milovice, Czech Republic. The prevailing vegetation type is a forest-steppe savanna with Bromus erectus-dominated xeric grasslands mixed with deciduous shrubs and trees. After the cessation of military use, the area was abandoned which led to successional changes, including the dominance of tall grasses, litter accumulation, and bush encroachment. In 2017–2021, we monitored grassland vegetation in 30 grazed permanent plots (2?×?2 m) and 5 control plots representative of ungrazed, abandoned vegetation adjacent to the grazed areas. Naturalistic grazing increased species richness and the cover of forbs, while the cover of grasses and legumes was minimally affected. Grazing increased functional diversity of plant community, promoted a compositional change to small statured species and an increased incidence of red-list species. Seven years of continuous grazing increased the conservation value of this forest-steppe vegetation, a habitat type rapidly declining in Europe.
Glycosylation of viral proteins is required for the progeny formation and infectivity of virtually all viruses. It is increasingly clear that distinct glycans also play pivotal roles in the virus's ability to shield and evade the host's immune system. Recently, there has been a great advancement in structural identification and quantitation of viral glycosylation, especially spike proteins. Given the ongoing pandemic and the high demand for structure analysis of SARS-CoV-2 densely glycosylated spike protein, mass spectrometry methodologies have been employed to accurately determine glycosylation patterns. There are still many challenges in the determination of site-specific glycosylation of SARS-CoV-2 viral spike protein. This is compounded by some conflicting results regarding glycan site occupancy and glycan structural characterization. These are probably due to differences in the expression systems, form of expressed spike glycoprotein, MS methodologies, and analysis software. In this review, we recap the glycosylation of spike protein and compare among various studies. Also, we describe the most recent advancements in glycosylation analysis in greater detail and we explain some misinterpretation of previously observed data in recent publications. Our study provides a comprehensive view of the spike protein glycosylation and highlights the importance of consistent glycosylation determination. 相似文献