71 research outputs found

    Potential phytotoxic and shading effects of invasive Fallopia (Polygonaceae) taxa on the germination of dominant native species

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    Two species of the genus Fallopia (F. sachalinensis, F. japonica, Polygonaceae) native to Asia, and their hybrid (F. ×bohemica), belong to the most noxious plant invaders in Europe. They impact highly on invaded plant communities, resulting in extremely poor native species richness. The low number of native species in invaded communities points to the possible existence of mechanisms suppressing their germination. In this study we assessed, under laboratory conditions, whether there are phytotoxic effects of the three Fallopia congeners on seed germination of three target species: two native species commonly growing in habitats that are often invaded by Fallopia taxa (Urtica dioica, Calamagrostis epigejos), and Lepidium sativum, a species commonly used in allelopathic bioassays as a control. Since Fallopia taxa form dense stands with high cover, we included varying light conditions as an additional factor, to simulate the effects of shading by leaf canopy on germination. The effects of aqueous extracts (2.5%, 5.0%, and 0% as a control) from dry leaves and rhizomes of the Fallopia congeners on germination of the target species were thus studied under two light regimes, simulating full daylight (white light) and light filtered through canopy (green light), and in dark as a control regime. Rhizome extracts did not affect germination. Light treatments yielded inconclusive results, indicating that poor germination and establishment of species in invaded stands is unlikely to be caused by shading alone. However, we found a pronounced phytotoxic effect of leaf extracts of Fallopia taxa, more so at 5.0% than 2.5% extract concentration. Fallopia sachalinensis exerted the largest negative effect on the germination of Urtica dioica, F. ×bohemica on that of C. epigejos, and F. japonica had invariably the lowest inhibitory effect on all test species. The weak phytotoxic effect of F. japonica corresponds to the results of previous studies that found this species to be generally a weaker competitor than its two congeners. Although these results do not necessarily provide direct evidence for allelopathic effects in the field, we demonstrate the potential phytotoxic effect of invasive Fallopia taxa on the germination of native species. This suggests that allelopathy may play a role in the impact of Fallopia invasion on species diversity of invaded communities

    Potential phytotoxic and shading effects of invasive Fallopia (Polygonaceae) taxa on the germination of dominant native species

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    Two species of the genus Fallopia (F. sachalinensis, F. japonica, Polygonaceae) native to Asia, and their hybrid (F. ×bohemica), belong to the most noxious plant invaders in Europe. They impact highly on invaded plant communities, resulting in extremely poor native species richness. The low number of native species in invaded communities points to the possible existence of mechanisms suppressing their germination. In this study we assessed, under laboratory conditions, whether there are phytotoxic effects of the three Fallopia congeners on seed germination of three target species: two native species commonly growing in habitats that are often invaded by Fallopia taxa (Urtica dioica, Calamagrostis epigejos), and Lepidium sativum, a species commonly used in allelopathic bioassays as a control. Since Fallopia taxa form dense stands with high cover, we included varying light conditions as an additional factor, to simulate the effects of shading by leaf canopy on germination. The effects of aqueous extracts (2.5%, 5.0%, and 0% as a control) from dry leaves and rhizomes of the Fallopia congeners on germination of the target species were thus studied under two light regimes, simulating full daylight (white light) and light filtered through canopy (green light), and in dark as a control regime. Rhizome extracts did not affect germination. Light treatments yielded inconclusive results, indicating that poor germination and establishment of species in invaded stands is unlikely to be caused by shading alone. However, we found a pronounced phytotoxic effect of leaf extracts of Fallopia taxa, more so at 5.0% than 2.5% extract concentration. Fallopia sachalinensis exerted the largest negative effect on the germination of Urtica dioica, F. ×bohemica on that of C. epigejos, and F. japonica had invariably the lowest inhibitory effect on all test species. The weak phytotoxic effect of F. japonica corresponds to the results of previous studies that found this species to be generally a weaker competitor than its two congeners. Although these results do not necessarily provide direct evidence for allelopathic effects in the field, we demonstrate the potential phytotoxic effect of invasive Fallopia taxa on the germination of native species. This suggests that allelopathy may play a role in the impact of Fallopia invasion on species diversity of invaded communities

    The Hurdy Gurdy Lesson at Art School

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    The thesis focuses on playing the hurdy gurdy and materials dealing with this theme. The work first presents the historical background of this musical instrument, its development, mechanics and possibilities of the instrument. Furthermore, it processes and compares the literature available for players dealing with the topic of playing the hurdy gurdy. The main content of the work is the creation of methodical material for playing the hurdy gurdy suitable as an aid for teaching in the Art school environment, as well as study material for self-taught students. This material contains the necessary information that a player needs to know during the beginnings of the hurdy gurdy playing, i.e., information starting with the functions of the individual parts of the instrument, through the adjustment and maintenance of the instrument to the explanation of the playing the instrument itself separately for the right- and left-hand technique. It also includes sheet music with a repertoire of widely played pieces on the hurdy gurdy. The benefit of the methodology is also the Czech language in which it is written, which can supplement the necessary, but currently missing information about playing this instrument in the Czech environment. The material was used for the teaching of playing the hurdy gurdy in the...Diplomová práce se zaměřuje na hru na niněru a materiály zpracovávající tuto tematiku. Práce nejdříve představuje historické pozadí tohoto hudebního nástroje, jeho vývoj, mechaniku a možnosti nástroje. Dále zpracovává a porovnává pro hráče dostupnou literaturu zabývající se tématem hry na niněru. Hlavní náplní práce je tvorba metodického materiálu pro hru na niněru využitelného jako pomůcku jak při výuce v prostředí ZUŠ, tak i jako studijního materiálu v rukou samouků. Tento materiál obsahuje potřebné informace, které hráč v začátcích hry na niněru potřebuje znát, tj. informace počínaje funkcemi jednotlivých částí nástroje, přes seřízení a údržbu niněry, až po vysvětlení hry samotné zvlášť pro techniku pravé a levé ruky. Součástí je i notový materiál s repertoárem skladeb na niněru hojně hraných. Přínosem metodiky je také český jazyk, ve kterém je napsána, čímž může doplnit potřebné, ale momentálně chybějící informace o hře na tento nástroj právě v českém prostředí. Materiál byl využit při výuce hry na niněru v základní umělecké škole, součástí práce je tedy i návrh školního vzdělávacího programu pro tento obor. Vhodnost materiálu byla ozkoušena v průběhu jednoho pololetí školního roku 2022/2023 v prostředí ZUŠ a taktéž v rukou několika samouků. V poslední části je poté popsána zpětná vazba a...Katedra hudební výchovyFaculty of EducationPedagogická fakult

    Determination of Bitter Compounds in Hops – Effect of Crop Year and Hops Age

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    Our study is focused on mutual comparison of four methods of determination of alpha acids in hops (EBC 7.4, EBC 7.5, ČSN and EBC 7.7) and their application in evaluation of hops stored under different conditions. Furthermore, the results of the comparison of predicted and actual alpha acid values in the long-term monitoring of harvesting of three Czech hop varieties are discussed. The largest differences were found between the EBC 7.5 (LCV) and EBC 7.7 (HPLC) methods; the first method gives systematically higher results and the difference exponentially increases with the hop storage index (HIS) value. The difference in HSI in fresh hops is 10 – 15% rel. while the difference in older hops with HSI 0.6 – 0.7 is 25 – 45% rel. Pre-harvest prognosis and harvest estimate of alpha acids in the Saaz variety are in good agreement with the facts (kr = 0.93, kr = 0.95) and the same holds for the harvest estimation relation and the reality of the varieties Sládek and Premiant (kr = 0.93; 0.97)

    Dark side of the fence: ornamental plants as a source of wild-growing flora in the Czech Republic

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    Ornamental plants constitute an important source of alien, and potentially invasive species, but also include a substantial part of native flora and consist of taxa that occur both in the wild and in cultivation; yet garden floras are largely ignored in ecological studies.We studied ornamental plants in the Czech Republic in order to provide detailed information, based on field sampling, on the diversity of taxa grown in cultivation in private gardens. Sampling was done in accessible public areas, private gardens and private areas in villages, town- and city neighbourhoods, garden allotments, cemeteries, areas of dispersed farmhouse settlements not accessible to the public, and in new urban sprawl. The data can be used to estimate the propagule pressure of individual taxa, measured in terms of the frequency with which they are planted in the gardens. To make the data comparable across sites, we adopted a two-level approach that resulted in producing a detailed list (including all the taxa recorded) and an aggregated list (merging closely related and similar taxa, which was necessary in order to assess the frequency of planting across sites). Each species on the detailed list was assigned an origin, status, life history and cultivation requirements. Comparing the field records with national checklists of both native and alien vascular plants we quantified particular components of the ornamental flora. The floristic inventories for 174 sites yielded 1842 taxa on the detailed list, consisting of 1642 species (standard binomials), 9 cultivars assigned to genera, 147 hybrids and hybridogenous taxa, and 44 taxa identified at higher than species level. Of these taxa 1417 (76.9%) were alien and 420 (22.8%) native. The ornamental flora consisted of not-escaping aliens, escaping aliens and cultivated natives. Of the recorded taxa, 841 (45.6%) occur both in cultivation and the wild. The aggregated list comprised 1514 taxa and resulted from merging 533 taxa from the detailed list into 205 taxa. Most alien ornamentals are native to Asia and Americas. The proportion of escaped and not-escaping aliens significantly differed from wild aliens in the spontaneous flora with underrepresentation of escaped, which originated from Australia, Africa and the Mediterranean area. Taxa from Africa and anecophytes were overrepresented and those from Australia, the Mediterranean and other parts of Europe underrepresented among not escaping aliens. The assessment of planting frequency revealed that 270 taxa were found at more than 25% of the sites, while 584 (40%) occurred at only one or two sites.Winter annuals and shrubs are most represented among the commonly planted aliens; the only native species with comparably high planting frequencies among the aliens, are Vinca minor, Hedera helix and Aquilegia vulgaris. Related to the invasion potential of ornamental garden flora we analysed the recorded taxa with respect to the transient/persistent character of their occurrence. The core (persistent) part of the flora comprised 599 taxa (32% of the total number of taxa) and the transient 240 (13%) taxa. The “grey zone” between the two included 1003 taxa (55%). The results reported here provide quantitative insights into the role of horticulture as a major pathway of plant invasions

    Classification of Czech Hops According to their Contents of Prenylflavonoids

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    The prenylated flavonoids are hop components with the most beneficial health effects. Information about their content and the dynamics of their decrease during hops processing is necessary for the production of beer with an increased content of these substances. This study deals with the long-term monitoring of the prenylflavonoids and α-bitter acids contents and their ratios in the whole spectrum of domestic hop varieties as well as with changes in these parameters during storage and hop processing. It was confirmed that the newly cultivated Agnus and Vital varieties are the varieties with the highest contents of prenylated flavonoids. As a result, the Vital variety is particularly useful in non-brewing applications. Based on the monitoring of the decrease in the levels of these components during hop processing it was recognised that development of new gentler methods, particularly for the hop drying would be necessary. These methods should minimize the risk of thermal and oxidative degradation

    Characterization of insulin crystalline form in isolated β-cell secretory granules

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    Insulin is stored in vivo inside the pancreatic β-cell insulin secretory granules. In vitro studies have led to an assumption that high insulin and Zn2+ concentrations inside the pancreatic β-cell insulin secretory granules should promote insulin crystalline state in the form of Zn2+-stabilized hexamers. Electron microscopic images of thin sections of the pancreatic β-cells often show a dense, regular pattern core, suggesting the presence of insulin crystals. However, the structural features of the storage forms of insulin in native preparations of secretory granules are unknown, because of their small size, fragile character and difficult handling. We isolated and investigated the secretory granules from MIN6 cells under near-native conditions, using cryo-electron microscopic (Cryo-EM) techniques. The analysis of these data from multiple intra-granular crystals revealed two different rhomboidal crystal lattices. The minor lattice has unit cell parameters (a ≃ b ≃ 84.0 Å, c ≃ 35.2 Å), similar to in vitro crystallized human 4Zn2+-insulin hexamer, whereas the largely prevalent unit cell has more than double c-axis (a ≃ b ≃ c ≃ 96.5 Å) that probably corresponds to two or three insulin hexamers in the asymmetric unit. Our experimental data show that insulin can be present in pancreatic MIN6 cell granules in a microcrystalline form, probably consisting of 4Zn2+-hexamers of this hormone

    Catalogue of alien plants of the Czech Republic (2nd edition): checklist update, taxonomic diversity and invasion patterns

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    A complete list of all alien taxa ever recorded in the flora of the Czech Republic is presented as an update of the original checklist published in 2002. New data accumulated in the last decade are incorporated and the listing and status of some taxa are reassessed based on improved knowledge. Alien flora of the Czech Republic consists of 1454 taxa listed with information on their taxonomic position, life history, geographic origin (or mode of origin, distinguishing anecophyte and hybrid), invasive status (casual; naturalized but not invasive; invasive), residence time status (archaeophyte vs neophyte), mode of introduction into the country (accidental, deliberate), and date of the first record. Additional information on species performance that was not part of the previous catalogue, i.e. on the width of species’ habitat niches, their dominance in invaded communities, and impact, is provided. The Czech alien flora consists of 350 (24.1%) archaeophytes and 1104 (75.9%) neophytes. The increase in the total number of taxa compared to the previous catalogue (1378) is due to addition of 151 taxa and removal of 75 (39 archaeophytes and 36 neophytes), important part of the latter being the reclassification of 41 taxa as native, mostly based on archaeobotanical evidence. The additions represent taxa newly recorded since 2002 and reported in the national literature; taxa resulting from investigation of sources omitted while preparing the previous catalogue; redetermination of previously reported taxa; reassessment of some taxa traditionally considered native for which the evidence suggests the opposite; and inclusion of intraspecific taxa previously not recognized in the flora. There are 44 taxa on the list that are reported in the present study for the first time as aliens introduced to the Czech Republic or escaped from cultivation.Práce přináší úplný seznam nepůvodních taxonů zaznamenaných na území České republiky; je aktualizací a doplněním předchozího seznamu publikovaného v roce 2002. Zahrnuje nové údaje shromážděné za poslední desetiletí a přehodnocuje zařazení a status některých druhů, vyplývající z rozvoje taxonomického poznání. Nepůvodní flóra České republiky zahrnuje 1454 taxonů, které jsou uvedeny v Apendixu 2 s informacemi o taxonomické příslušnosti, životní formě, oblasti původu, invazním statusu (zda jde o druh přechodně zavlečený, naturalizovaný avšak neinvazní, nebo invazní), charakteru výskytu v krajině, době zavlečení (archeofyt nebo neofyt), způsobu introdukce do země a u neofytů o datu prvního nálezu. Oproti původnímu katalogu je uveden počet typů biotopů, ve kterých se druh vyskytuje, pokryvnost v rostlinných společenstvech a impakt. Podíl zavlečených druhů v české flóře je značný: tvoří jej 350 (24,1%) archeofytů a 1104 (75.9%) neofytů. Nárůst počtu taxonů oproti původnímu katalogu, který uváděl 1378 taxonů, vyplývá z toho, že bylo přidáno 151 taxonů. Celkem 75 (39 archeofytů a 36 neofytů) bylo naproti tomu vypuštěno; značná část tohoto počtu jde na vrub přeřazení 41 taxonů mezi původní druhy, a to vesměs na základě archeobotanických dokladů. Přírůstky na seznamu představují taxony nově objevené a uvedené v botanické literatuře od roku 2002, taxony zařazené na základě excerpce dříve opominutých zdrojů či revize zdrojů použitých, nebo přehodnocení statusu některých taxonů tradičně považovaných za původní. Vněkterých případech jde o infraspecifické taxony, které nebyly dříve v české flóře rozeznávány. Seznam obsahuje 44 taxonů, které jsou uváděny pro Českou republiku poprvé jako zavlečené, nebo pro něž je podán první důkaz o jejich zplaňování

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Consumer behavior and its impact on the sharing economy

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    Diplomová práce se zabývá spotřebitelským chováním, resp. sdílenou ekonomikou. Práce se věnuje analýze těchto dvou pojmů a jejich vlivu, který mají vůči sobě navzájem. Cílem je prokázání vlivu spotřebitelského chování na služby sdílené ekonomiky a dokázání toho, že značný rozvoj sdílené ekonomiky v posledních letech úzce souvisí s vývojem, resp. změnou spotřebitelského chování. Závěr práce se věnuje také doporučení pro oblast sdílené ekonomiky.The master thesis deals with a consumer behavior, resp. with a sharing economy. The purpose of the thesis is an analysis of these two concepts and of their impact on each other. The aim of the thesis is to demonstrate the influence of the consumer behavior on the services of sharing economy. Furthermore, the master thesis should prove that the significant expansion of the sharing economy in last years is closely related to the changes in the consumer behavior. The conclusion of this master thesis is devoted to recommendations for the future development of the sharing economy
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