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44332. Vegetation of lowland wet meadows along a climatic continentality gradient in Central Europe
- Creator:
- Botta-Dukát, Zoltán, Chytrý, Milan, Hájková, Petra, and Havlová, Marcela
- Type:
- article and TEXT
- Subject:
- Czech Republic, fidelity, Hungary, Molinio-Arrhenatheretea, numerical analysis, optimal number of clusters, phytosociological classification, Slovakia, and vegetation survey
- Language:
- English
- Description:
- Central European lowland wet meadows are habitats of great conservation interest, however, their phytosociological status has been to a large extent dependent on specific phytosociological traditions in different countries. In order to bridge the gaps between different national schemes of vegetation classification, a statistical analysis of variation in species composition of these meadows in the Czech Republic, E Austria, Slovakia, Hungary and NE Croatia was performed, using a data set of 387 geographically stratified vegetation relevés sampled at altitudes < 350 m. Principal coordinates analysiswas used to identify and partial out the noise component in the variation in this data set. The relevés were classified by cluster analysis. A new method for identifying the optimal number of clusters was developed, based on species fidelity to particular clusters. This method suggested the optimum level of classification with three clusters and secondary optimum levels with five and nine clusters. Classification based on three clusters separated the traditional phytosociological alliances of Calthion palustris and Molinion caeruleae, both with a suboceanic phytogeographical affinity, and a group of flooded meadows of large river alluvia, with a continental affinity. The latter group included the traditional alliances of Agrostion albae, Alopecurion pratensis, Cnidion venosi, Deschampsion cespitosae and Veronico longifoliae-Lysimachion vulgaris; however, the internal heterogeneity of this group did not reflect putative boundaries between these alliances as proposed in the phytosociological literature. Therefore we suggest to unite these alliances in a single alliance Deschampsion cespitosae Horvatić 1930 (the oldest valid name). Classification with nine clusters was interpreted at the level of broad phytosociological associations. Particular clusters were characterized by statistically defined groups of diagnostic species and related to macroclimatic variables.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
44333. Vegetation succession over broad geographical scales
- Creator:
- Prach, Karel and Řehounková, Klára
- Type:
- article and TEXT
- Subject:
- environmental factors, landscape context, restoration ecology, species pool, and vegetation succession
- Language:
- English
- Description:
- We reviewed 37 studies on vegetation succession in which the succession started on bare ground, was followed in at least six sites, and where these sites were spatially separated over at least 10 km2. The effect of environmental factors, which were explored in at least five studies, on the course of succession was assessed, based on the proportion of significant and non-significant results. Surrounding vegetation, macroclimate, soil moisture, amount of nitrogen and soil texture appeared to have the highest influence on the course of succession. Less influential were the size of a disturbed site, pH, organic matter and phosphorus content. Surrounding vegetation exhibited a significant effect in all cases where this was considered. These results imply that succession cannot be studied without the landscape context. The large-scale approach to succession has the potential to contribute substantially to both the theory of succession and practical applications, especially in restoration ecology.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
44334. Vegetation types of dry-mesic oak forests in Slovakia
- Creator:
- Roleček, Jan
- Type:
- article and TEXT
- Subject:
- classification, phytosociology, Quercetalia pubescenti.petraeae, Quercus, syntaxonomy, vegetation typology, and vegetation survey
- Language:
- English
- Description:
- Typology of dry-mesic oak forest vegetation of Slovakia is presented. Seven vegetation types were distinguished based on a Braun-Blanquetian relevé data analysis using a TWINSPAN classification algorithm. The identified vegetation types are related to seven syntaxa traditionally used by Central European phytosociologists: dry-mesic oak forest on sandy soils – Carici fritschii-Quercetum roboris, dry-mesic oak forest on heavy soils – Potentillo albae-Quercetum, dry-mesic oak forest on basic rocky substrates – Corno-Quercetum, dry-mesic oak forest on acidic substrates – Sorbo torminalis-Quercetum, dry oak forest on loess – Quercetum pubescenti-roboris, dry-mesic oak forest on loess – Convallario-Quercetum roboris, dry-mesic forest of Turkey oak – Quercetum petraeae-cerris. Detrended correspondence analysis was used to visualize the similarity of vegetation types. Some aspects of dry-mesic oak forest ecology, distribution and dynamics in Slovakia are discussed; their general retreat due to mesophilous tree species expansion is stressed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
44335. Vegetation-plot data and databases in Europe
- Creator:
- Schaminée, Joop H. J., Hennekens, Stephan M., Chytrý, Milan, and Rodwell, John S.
- Type:
- article and TEXT
- Subject:
- biodiversity, eco-informatics, Habitats Directive, macroecology, nature conservation, phytosociology, relevé, and TURBOVEG
- Language:
- English
- Description:
- During the last decade many electronic databases of vegetation plots, mainly phytosociological relevés, were established in different European countries. These databases contain information which is extremely valuable for both testing various macroecological hypotheses and for nature conservation surveying or monitoring. The aim of this paper is to provide estimates of the number of vegetation plots there are in Europe, how many are stored in an electronic format and to assess their distribution across European countries and regions.We sent a questionnaire to the managers of national or regional databases of vegetation plots and other prominent vegetation ecologists. Meta-data obtained in this way indicate that there are > 4,300,000 vegetation-plot records in Europe, of which > 1,800,000 are already stored electronically. Of the electronic plots, 60% are stored in TURBOVEG databases. Most plot records probably exist in Germany, the Netherlands, France, Poland, Spain, Czech Republic, Italy, UK, Switzerland and Austria. The largest numbers of plots per unit area are in the Netherlands, Belgium, Denmark and countries of central Europe. The most computerized plots per country exist in the Netherlands (600,000), followed by France, the Czech Republic and the UK. Due to its strong phytosociological tradition, Europe has many more vegetation plots than any other part of the world. This wealth of unique ecological information is a challenge for future biodiversity studies. With the alarming loss in biodiversity and environmental problems like global warming and ongoing changes in land use, there is an urgent need for wide-scale scientific and applied vegetation research. Developments of information systems such as SynBioSys Europe and facilitation of data flow between the national and regional databases should make it easier to use these vegetation-plot data.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
44336. Vehicles' weight method under operation
- Creator:
- Kadleček, B., Pejsa, L., and Kovanda, J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Dynamic weighing of vehicles, telematic system, torque, forward thrust on the wheels, road gradient, and running ressistance
- Language:
- English
- Description:
- The article contains an example detailing the application and analysis of the accuracy of the method called continuous dynamic vehicle weighing during travel, using the telematic system. A model was built using the input data obtained through laboratory experiments on a running vehicle. This model was then applied to study the effects of error probability for the measured input data on the resulting expected accuracy of vehicle weight measuring in a normal running regime. Based on this point, hereby presented is a proposal of selected measured variables of great importance, and a proposal for the computation relationship of the used variables. By statistically processing a set of measured data taken during one vehicle travel, it is possible to attain -10.7% extreme relative error of the given method for the dynamic determination of vehicle weight.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44337. Věkem podmíněná makulární degenerace
- Creator:
- Fišer, Ivan
- Type:
- model:article, article, Text, and TEXT
- Subject:
- lidé, staří, věk při počátku nemoci, aptamery nukleotidové--terapeutické užití, monoklonální protilátky--terapeutické užití, vaskulární endoteliální růstový faktor A--terapeutické užití, anti-VEGF, Avastin, Lucentis, and Macugen
- Language:
- Czech and English
- Description:
- Věkem podmíněná makulární degenerace (VPMD) je v rozvinutých zemích nejčastější příčinou ztráty zraku lidí starších 55 let. Vlhká forma této choroby je příčinou těžké ztráty zraku u 90 % postižených. VPMD vzniká spolupůsobením genetických faktorů a faktorů životního stylu. Klíčovým mechanizmem vzniku vlhké formy VPMD je novotvorba cév, stimulovaná růstovým faktorem VEGF. Léčbou volby VPMD jsou proto preparáty anti-VEGF, podávané formou injekcí do sklivce. V mezinárodních studiích jsou zkoumány nové léky na VPMD. Léčbu je třeba zahájit včas, dokud není vážně postižena zraková ostrost., Age-related macular degeneration (AMD) is the most common cause of vision loss in developed countries in people older than 55 years. The wet form of this disease is the cause of severe vision impairment in 90 percent of patients. AMD develops as a result of an interaction between genetic and lifestyle factors. The key mechanism in the development of wet AMD is the growth of new vessels, stimulated by the vascular endothelial growth factor (VEGF). The treatment of choice is, therefore, the use of anti-VEGF agents administered as intravitreal injections. International clinical studies are evaluating new AMD treatments. It is necessary to start the treatment early, before severe visual impairment occurs., I. Fišer, and Lit.: 20
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44338. Věkové a mezipohlavní rozdíly v rozměrech zubního oblouku dolní čelisti nedospělých jedinců: Brněnská sbírka sádrových ortodontických modelů chrupu
- Creator:
- Dadejová, Vlasta, Králík, Miroslav, and Urbanová, Petra
- Format:
- 13-29, print, text, and regular print
- Type:
- model:article, article, Text, biography, historické články, and TEXT
- Subject:
- maxila--anatomie a histologie--růst a vývoj, zubní oblouk--anatomie a histologie--růst a vývoj, cefalometrie--metody, sexuální faktory, věkové faktory, statistická rozdělení, ortodoncie korekční--metody, lidé, věkové skupiny, ženské pohlaví, and mužské pohlaví
- Language:
- Czech and English
- Description:
- Hodnocení mezipohlavních rozdílů v utváření dolní čelisti je jednou z mála možností, jak lze u nedospělých skeletů morfo-- logicky odhadovat pohlaví. V této průřezové studii jsme se pokusili morfometricky prostudovat věkové rozdíly a ověřit existenci pohlavního dimorfismu ve velikosti a tvaru zubního oblouku dolní čelisti u nedospělých jedinců recentní české populace. Vzorek tvořilo 163 sádrových modelů dolních čelistí ortodontických pacientů, vybraných z Brněnské sbírky sádrových ortodontických modelů chrupu na základě stupně prořezání a nepřítomnosti zjevných patologií v rozsahu I(i)1–M1. Mladší kategorie od 7,5 let včetně do 9,5 let sestávala ze 77 případů (35 mužů a 42 žen), starší kategorie od 14 let včetně do 20 let z 86 případů (36 mužů a 50 žen). Velikost a tvar zubního oblouku jsme na standar dizovaných fotografiích okluzní roviny hodnotili morfometricky pomocí jedenácti rozměrů, definovaných význačnými body na předních řezácích, špičácích a prvních trvalých stoličkách. Tvar jsme hodnotili pomocí šesti indexů. Ženy měly celkově menší rozměry zubního oblouku než muži stejné věkové kategorie, ve vyšší věkové kategorii byl velikostní dimorfismus mírně vyšší, ve většině rozměrů však nepřesahoval 5%. Rozdíly mezi věkovými kategoriemi nejsou jen odrazem prostého zvětšování čelisti v průběhu postnatálního růstu. Délka distální části zubního oblouku (C(c)–M1) je ve vyšším věku u obou pohlaví menší. To může být způsobeno stěsnáváním mesiálnějších zubů s tím, jak se postupně prořezávají zuby distálnější. Ve většině hodnocených indexů se pohlaví výrazně nelišila, výjimkou byl Index vystupování špičáku v mladší věkové kategorii. Špičák vystupoval z oblouku bukálním směrem výrazněji ženám než mužům. Diskuse je věnována srovnání zjištěného dimorfismu s předchozími studiemi a vlivům, jejichž prostřednictvím mohl klinický charakter sbírky a způsob výběru vzorku ov- livnit zjištěné mezipohlavní rozdíly., The evaluation of sex differences in mandibular development of subadult skeletons is one of the few possible methods of determining sex using morphological characteristics. In this cross-sectional study, we attempted to morphometrically investigate age differences and to confirm the existence of sexual dimorphism using the size and shape of mandibular dental arch in subadults from a recent Czech population. The sample consisted of 163 plaster casts of mandibles from orthodontic patients in the Brno Collection of Orthodontic Den - tal Plaster Casts , selected on the basis of the degree of tooth eruption and the absence of visible pathological conditions in the I(i)1–M1 range. The younger age category ranging from 7,5 years to 9,5 years accounted for 77 cases (35 males and 42 females) and the older age category rang- ing from 14 to 20 years accounted for 86 cases (36 males and 50 females). The size and shape of the dental arch was evaluated using standar- dized photographs of the occlusal plane by employing eleven dimensions, with landmarks on central incisors, canines and first permanent molars. Shape was evaluated using six indices. The mean size of the dental arch was smaller in females than in males in the same age category. In the older age category the sexual dimorphism was slightly greater, but did not exceed 5% in most measurements. Differences between age categories cannot be explained as a simple reflection of increasing size of the mandible with postnatal growth. The length of the distal segment of the dental arch (C(c)–M1 range) is shorter in the older category in both sexes. This could be caused by crowding of mesial teeth, with gradual eruption of distal teeth. Sex differences were not recorded in most shape indices, except for the Canine Protrusion Index in the younger age category. Canine protrusion from the arch in the buccal direction was greater in females than in males. The discussion is focused on comparison of the observed dimorphism with results found in previous studies and also on possible ways in which the clinical character of the collection and method of sample selection could have affected the detected inter-sex differences., Vlasta Dadejová, Miroslav Králík, Petra Urbanová, and Literatura
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
44339. Velehrad na křižovatkách evropských dějin /
- Creator:
- Altrichter, Michal,
- Type:
- text, katalogy výstav, monografie kolektivní, and publikace obrazové
- Subject:
- Liturgie. Křesťanské umění a symbolika. Duchovní život, kláštery, místa poutní, tradice cyrilometodějská, české (československé) sborníky a kolektivní monografie, přehledná zpracování dějin českých zemí (chronologicky), and církevní řády a kongregace, náboženská bratrstva, kláštery
- Language:
- Czech and English
- Rights:
- unknown
44340. Velehrad na křižovatkách evropských dějin /
- Creator:
- Altrichter, Michal,
- Type:
- text, katalogy výstav, monografie kolektivní, and publikace obrazové
- Subject:
- Liturgie. Křesťanské umění a symbolika. Duchovní život, kláštery, místa poutní, tradice cyrilometodějská, české (československé) sborníky a kolektivní monografie, přehledná zpracování dějin českých zemí (chronologicky), and církevní řády a kongregace, náboženská bratrstva, kláštery
- Language:
- Czech and English
- Rights:
- unknown