No (5624)
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Význam polních mokřadů v zemědělské krajině
Šumberová, Kateřina; Vymyslický, T.; Fabšičová, Martina; Fránková, Markéta
2021 - Czech
Polní mokřady představují mimořádně cenný biotop v zemědělské krajině, nejen z hlediska hospodaření s vodou, ale i z hlediska biodiverzity různých skupin organismů. Druhy obývající tyto biotopy přežívají nepříznivá období ve formě semen, spor a vajíček v půdě, řada z nich patří k ohroženým skupinám organismů. Náš výzkum přinesl nové nálezy vzácných druhů cévnatých rostlin, ale i zajímavé nálezy rozmanitých druhů mikro i makroskopických řas. K nejvýznamnějším nálezům patří některé teplomilné a mírně slanomilné druhy rostlin a řas, jejichž výskyt u nás je vázán především na jižní Moravu. Nalezeno bylo 17 druhů rostlin z aktuálního Červeného seznamu tři druhy v kategorii kriticky ohrožených (C1: Hibiscus trionum, Pulicaria dysenterica, P vulgaris), šest druhů silně ohrožených (C2: Lythrum hyssopifolia, Malva pusilla, Rumex tenophyllus, Schoenoplectus tabernaemontani, Veronica anagalloides), pět druhů v kategorii ohrožených (C3: Centaurium pulchellum, Cyperus fuscus, Lemna trisulca, Lotus tenuis, Veronica catenata) a pět vzácnějších druhů vyžadujících pozornost (C4: Bolboschoenus laticarpus, B planiculmis, Butomus umbellatus, Limosella aquatica, Schoenoplectus lacustris). Vegetaci na studovaných lokalitách bylo možno zařadit do pěti syntaxonomických tříd: Lemnetea, Potametea, Isoëto-Nanojuncetea, Bidentetea tripartitae a Phragmito-Magnocaricetea. Cévnaté rostliny byly zastoupeny několika ekologickými skupinami: jednoleté mokřadní rostliny, vytrvalé druhy rákosin a vlhkých narušovaných trávníků, vlhkomilné plevele a ruderální druhy, vodní rostliny. Makroskopické řasy byly zastoupeny především vláknitými zelenými řasami rodů žabí vlas (Cladophora) šroubatka (Spirogyra a Oedogonium), méně pak různobrvkami (Vaucheria spp.) a sinicemi (Nostoc spp.). Parožnatky (Characeae) osídlovaly mokřady s delším obdobím zaplavení. Kvantitativně nejvíce zastoupenou a zároveň druhově nejbohatší skupinou mikroskopických řas zkoumaných mokřadů byly rozsivky (Achnanthidium, Amphora, Gomphonema, Navicula, Nitzschia, Pinnularia, Surirella aTryblionella) následovala krásnoočka (Colacium, Euglena, Trachelomonas), zelené řasy (Desmodesmus) a sinice (Homoeothrix a Phormidium).Byla zaznamenána vysoká variabilita v počtu druhů cévnatých rostlin a celkovém druhovém složení i v zastoupení jednotlivých skupin řas a jejich druhové bohatosti. Byly patrné velké změny mezi lety i během roku. Field wetlands represent an extremely valuable biotope in agricultural landscapes, not only in terms of water management, but also in terms of biodiversity of various groups of organisms. Species living in these habitats survive adverse periods in the form of seeds, spores and eggs in the soil, many of them belonging to endangered groups of organisms. Our research has yielded in new findings of rare vascular plant species, as well as interesting findings of diverse species of micro- and macroscopic algae. Among the most important findings are some thermophilic and slightly halophilic vascular and algae species, whose occurrence in our country is mainly linked to southern Moravia. Seventeen plant species from the current Red List were found, three species in the critically endangered category (C1: Hibiscus trionum, Pulicaria dysenterica, P vulgaris), six species in the severely endangered category (C2: Lythrum hyssopifolia, Malva pusilla, Rumex tenophyllus, Schoenoplectus tabernaemontani, Veronica anagalloides), five species in the endangered category (C3: Centaurium pulchellum, Cyperus fuscus, Lemna trisulca, Lotus tenuis, Veronica catenata) and five rarer species requiring attention (C4: Bolboschoenus laticarpus, B planiculmis, Butomus umbellatus, Limosella aquatica, Schoenoplectus lacustris). The vegetation at the study sites could be classified into five syntaxonomic classes: Lemnetea, Potametea, Isoëto-Nanojuncetea, Bidentetea tripartitae and Phragmito-Magnocaricetea. Vascular plants were represented by several ecological groups: annual wetland plants, perennial species of reed beds and wet disturbed grasslands, hydrophilous weeds and ruderal species, and aquatic plants. Macroscopic algae were represented primarily by filamentous green algae of the genera Cladophora, Spirogyra and Oedogonium, and to a lesser extent by the genus Vaucheria spp., and by cyanobacteria (Nostoc spp.). The representatives of the genus Chara inhabited wetlands with longer periods of inundation. Diatoms (Achnanthidium, Amphora, Gomphonema, Navicula, Nitzschia, Pinnularia, Surirella and Tryblionella) were the most quantitatively represented and species-rich group of microalgae in the studied wetlands, followed by the genera Colacium, Euglena and Trachelomonas, by green algae (Desmodesmus), and by cyanobacteria (Homoeothrix and Phormidium).There was a high variability in the number of vascular plants and overall species composition, as well as in the representation of different algal groups and their species richness. Large changes were evident between and within years.
Keywords:
biodiversity; agriculture; drought
Available at various institutes of the ASCR
Význam polních mokřadů v zemědělské krajině
Polní mokřady představují mimořádně cenný biotop v zemědělské krajině, nejen z hlediska hospodaření s vodou, ale i z hlediska biodiverzity různých skupin organismů. Druhy obývající tyto biotopy ...
A variety of transpiration in the young spruce stands with different thinning management
Zavadilová, Ina; Szatniewska, Justyna; Vágner, Lukáš; Krejza, Jan; Pavelka, Marian
2021 - English
Managing the spruce forest growing beyond its favourable conditions is trading between water consumption and increasing biomass. We examined tree transpiration in four stands with different thinning intensities in a 40-year-old spruce forest in South Moravia. Tree transpiration was significantly higher under moderate and heavy intensity compared to low intensity and control plots. Tree transpiration differed also among trees of different sizes within the treatments and also between the treatments. The stem increment was visibly increasing with the intensity of treatment, particularly for suppressed trees. The findings show an ecological tree response two years after the thinning.
Keywords:
norway spruce; norway spruce; water consumption; sap flow; biomass production; thinning treatment
Available at various institutes of the ASCR
A variety of transpiration in the young spruce stands with different thinning management
Managing the spruce forest growing beyond its favourable conditions is trading between water consumption and increasing biomass. We examined tree transpiration in four stands with different thinning ...
Metalothioneiny jako biomarkery znečištění životního prostředí
Šestáková, Ivana; Křivská, D.; Navrátil, Tomáš
2021 - Czech
Sledování obsahu metalothioneinů jako biomarkeru znečištění vodního prostředí je\npředmětem řady studií i mezinárodního programu (Mediterranean Action Plan of The United\nNations Environment Program, 1999). Pro sledování vlivu kontaminace půdy jsou vhodnou\nmožností volně žijící drobní savci, kde hladiny metalothioneinů závisí na obsazích kovů\nv půdě, a i na dietních zvyklostech (omnivoři, herbivoři, karnivoři). V posledním desetiletí\nnabývají na významu studie vlivu parazitů, kde je popisován jak pozitivní, tak negativní vliv\nparazitů na obsahy kovů ve tkáních hostitele. U některých parazitů ryb byl zjištěn řádový nárůst\nobsahu kovů ve tkáních parazitu, který vedl k uvažování možnosti užití právě parazitů jako\nindikátoru znečištění. Small wild mammals living at contaminated soil are exploited for monitoring of their metal and\nmetallothionein (MT) levels, which can be influenced by presence of parasites. This has been\ntested in laboratory experiment with white rats (Rattus norvegicus) infected with tapeworm\nHimenolepis diminuta and given diet enriched with lead or zinc. The influence of parasite was\nconfirmed with analysis of samples, where metal concentrations in infected groups were\nlowered in comparison with the uninfected rats. Within infected groups, tapeworms MT levels\nwere 6 or 3 times higher than MT in tapeworms of the control group. Obtained results support\npossibility of using MT concentration in Himenolepis diminuta for biomonitoring.
Keywords:
metallothioneins; lead; zinc; rats
Available on request at various institutes of the ASCR
Metalothioneiny jako biomarkery znečištění životního prostředí
Sledování obsahu metalothioneinů jako biomarkeru znečištění vodního prostředí je\npředmětem řady studií i mezinárodního programu (Mediterranean Action Plan of The United\nNations Environment Program, ...
Voltametrické stanovení těžkých kovů ve včelím jedu za použití rtuťové kapkové elektrody a uhlíkového vodivého filamentu pro 3D tisk
Navrátil, Tomáš; Choińska-Mlynarczyk, Marta; Šestáková, Ivana; Hrdlička, Vojtěch
2021 - Czech
Včelí jed představuje sekret z jedového ústrojí včelích dělnic nebo včelí matky (nikoliv trubců).\nSmrtelná dávka pro člověka je asi 400-700 žihadel, LD50 myší i.v.=0,6 mg/kg. Po vysušení\nvzniká světle žlutý, velmi jemný prášek. Je rozpustný ve vodě za vzniku opaleskujícího roztoku.\nTypické složení (procenta představují podíl látky v sušině):\n -50-55 % silně bazický polypeptid melitin (poškozuje červené i bílé krvinky), 2-3 %\nappamin (vliv na nervovou soustavu), MCD (mast cell degranulating) peptid (narušuje\nčinnost buněčných membrán,\n Enzymy: 13-14 % fosfolypáza A a B, 2-3 % hyaluronidáza,\n Biogenní aminy: histamin, dopamin, noradrenalin.\nKromě výše uvedených látek jsou v jedu, podobně jako ve včelím medu, obsaženy látky, se\nkterými přichází tento blanokřídlý hmyz do styku během svého života. Jedná se tedy i o těžké\nkovy, kterými je kontaminováno naše životní prostředí. Analýza včelího jedu včel\nmedonosných žijících ve zvolené oblasti může tedy poskytnout informaci o plošném znečištění\npoměrně velké oblasti. Heavy metals belong to typical contaminants of our environment. It is known that they are\nmetabolized and incorporated into bee products as honey as well as honeybee venom (apitoxin).\nIt is supposed that their composition can reflect contamination of the “bee environment” and\ncan give us information about the environment in the neighborhood of human dwellings.\nThis study aimed to develop a simple method for the determination of heavy metals in honeybee\nvenom. Due to the complicated matrix, wet microwave mineralization with sulfuric acid, nitric\nacid, under increased temperature and pressure, and repeated boiling with concentrated nitric\nacid had to be applied. Voltammetry proved to be very suitable for the determination of heavy\nmetals.\nTwo types of working electrodes have been used: pen-type hanging mercury drop electrode and\ncarbon conductive filaments for 3D printers. Results achieved using both of them and their\nadvantages and limitations have been compared.
Keywords:
anodic stripping voltammetry; heavy metals; honeybee venom
Available on request at various institutes of the ASCR
Voltametrické stanovení těžkých kovů ve včelím jedu za použití rtuťové kapkové elektrody a uhlíkového vodivého filamentu pro 3D tisk
Včelí jed představuje sekret z jedového ústrojí včelích dělnic nebo včelí matky (nikoliv trubců).\nSmrtelná dávka pro člověka je asi 400-700 žihadel, LD50 myší i.v.=0,6 mg/kg. Po vysušení\nvzniká ...
Rozdíly v elektrochemické redukci jedno- a vícejaderných acylgermanů
Šimková, Ludmila; Dunlop, David; Liška, Alan; Ludvík, Jiří
2021 - Czech
Derivaty titanocenu nachazeji bohate vyuziti jako katalyzatory pri cele fade chemickych\ntransformaci. Nicmene v posledni dobe se zkouma i jejich potencialni vyuziti jako cytostatik\npri lecbe onkologickych onemocneni. Nedavne studie poukazaly na vyssi cytotoxicitu u cele\nfady titanocen difluoridovych derivatu v porovnani s jejich dichloridovymi analogy.\nNasledne zkoumani mechanismu ucinku titanocemi poukazalo na rozpad endoplasmatickeho\nretikula rakovinnych bunek pusobenim reaktivnich kyslikovych castic (ROS). Tyto castice\ngenerovane pomoci redoxne aktivnich kovu (v nasem pripade titanocenu) muzou byt ucinnym\nprostredkem pro selektivni likvidaci rakovinovych bunek, jejichz homeostaza je na pritomnost\nROS citlivejsi V porovnani se zdravymi bunkami. Recently, titanocene derivatives have been investigated in term of their potential use as\ncytostatics in the treatment of oncological diseases. The potentials for reduction or oxidation of\nindividual substances are one of the key properties which fundamentally affect the cytostatic\nefficiency. Our previous results led us to investigate the redox properties of series of titanocene\ndifluoride and dichloride derivatives. This study is mainly focused on the effect of the\nsubstitution of cyclopentadienyl ring and the halide anion on the redox properties of the\nderivative.
Keywords:
Titanocene derivatives; Tuning of redox behavior; Substitution of cyclopentadienyl ring
Available on request at various institutes of the ASCR
Rozdíly v elektrochemické redukci jedno- a vícejaderných acylgermanů
Derivaty titanocenu nachazeji bohate vyuziti jako katalyzatory pri cele fade chemickych\ntransformaci. Nicmene v posledni dobe se zkouma i jejich potencialni vyuziti jako cytostatik\npri lecbe ...
Effect of elevated CO2 concentration and nitrogen nutrition on mais response to short-term high temperature and drought stress
Simor, J.; Klem, Karel
2021 - English
Within an experiment conducted in open top chambers in which two mais genotypes differing in stay-green trait were cultivated under elevated atmospheric CO2 concentration (EC) in comparison\nwith ambient CO2 concentration (AC), and in two contrast levels of nitrogen nutrition, the effect of acclimation to these factors on photosynthetic performance and water use efficiency, and subsequent response to short-term high temperature and drought stress was studied. Although EC improved water use efficiency, this effect did not alleviate the response to drought stress, and under some combinations of factors even led to a decrease in CO2 assimilation rate under drought stress. Differences in the stay- green trait between genotypes did not have a major effect on the response to high temperature and drought stress. Differences between genotypes were manifested mainly in the interaction with nitrogen nutrition, while in the Korynt genotype, non fertilised variants showed a lower response of CO2 assimilation rate to drought. Slight alleviating effect of higher nitrogen dose was found under EC conditions, while no nitrogen fertilisation rather increased drought resilience under AC conditions.
Keywords:
mais; elevated carbon dioxide; nitrogen nutrition; drought stress
Available at various institutes of the ASCR
Effect of elevated CO2 concentration and nitrogen nutrition on mais response to short-term high temperature and drought stress
Within an experiment conducted in open top chambers in which two mais genotypes differing in stay-green trait were cultivated under elevated atmospheric CO2 concentration (EC) in comparison\nwith ...
Preparation, Testing and Application of Amalgam Screen-Printed Electrodes
Josypčuk, Bohdan; Langmaier, Jan; Tvorynska, Sofiia
2021 - English
Silver amalgam screen-printed electrodes (AgA-SPEs) were designed, prepared, and tested for\nthe first time as perspective representatives among SPEs for measuring at high negative\npotentials. The precise coulometric preparation procedure for mercury deposition at the\nworking electrode surface of the commercial silver-SPE was developed. An optimal\nelectrolyzer construction for the mercury deposition, electrolyte composition, and electrolysis\nconditions were proposed. The maximum value of hydrogen overvoltage (-1979 ± 4 mV) was\nfound on AgA-SPE with 50% (w/w) of Hg content in 0.1 mol L-1 NaOH, which is more negative\nthan with the original silver-SPE for 387 mV (-1592 ± 12 mV).
Keywords:
electrochemistry; screen-printed electrodes; silver amalgam
Available on request at various institutes of the ASCR
Preparation, Testing and Application of Amalgam Screen-Printed Electrodes
Silver amalgam screen-printed electrodes (AgA-SPEs) were designed, prepared, and tested for\nthe first time as perspective representatives among SPEs for measuring at high negative\npotentials. The ...
Electrochemistry of Phospholes
Koláčná, Lucie; Liška, Alan; Ludvík, Jiří
2021 - English
Seventeen pentasubstituted phospholes with expected application in organic electronics were\nsynthesized and characterized electrochemically and by UV-vis spectra. Quantum chemical\ncalculations ofredox potentials and HOMO-LUMO energies were performed and experimental\nand theoretical data were successfully correlated. Tuning of redox properties can be achieved\nby combination of induction and resonance effects of substituents, extension / diminution of\nthe pi- delocalized system and by steric changes which affect intramolecular electron\ncommunication.
Keywords:
Pentasubstituted phospholes; Electrochemistry; UV-vis spectra
Available on request at various institutes of the ASCR
Electrochemistry of Phospholes
Seventeen pentasubstituted phospholes with expected application in organic electronics were\nsynthesized and characterized electrochemically and by UV-vis spectra. Quantum chemical\ncalculations ...
Electrochemical Characterization of Molecular Conductors Containing Redox Switching Element
Nováková Lachmanová, Štěpánka; Vavrek, František; Sebechlebská, Táňa; Šebera, Jakub; Kolivoška, Viliam; Lukášek, J.; Balzer, N.; Valášek, M.; Mayor, M.; Hromadová, Magdaléna
2021 - English
Electrochemical properties of new molecules containing tripodal anchor and redox switching\nelement have been studied by cyclic voltammetry and DFT quantum mechanical calculations.\nComparison of their redox properties with individual organometallic [Ru(terpy)2]2+t3+ and\n[Os(terpy)2]2+t3+ redox centers shows that covalently bonded tripodal anchor does not\ncompromise the reversibility of a redox process and has no effect on the stability of new\nmolecules. New molecular conductors have smaller HOMO-LUMO gap and both are oxidized\nat only slightly more positive potentials after tripodal substitution making them suitable for the\ndevelopment of molecular conductors with switching abilities.
Keywords:
Tripodal anchor; Cyclic voltammetry; DFT calculations
Available on request at various institutes of the ASCR
Electrochemical Characterization of Molecular Conductors Containing Redox Switching Element
Electrochemical properties of new molecules containing tripodal anchor and redox switching\nelement have been studied by cyclic voltammetry and DFT quantum mechanical calculations.\nComparison of ...
Electroplating of 3D Printed Electrodes for Selective Electrochemical Reduction of C02
Vaněčková, Eva; Bouša, Milan; Shestivska, Violetta; Kubišta, Jiří; Rathouský, Jiří; Sebechlebská, Táňa; Kolivoška, Viliam
2021 - English
In this work, computer assisted design and fused deposition modelling 3D printing are\nemployed to devise and manufacture electrodes from polylactic acid-carbon nanotube\nconductive composite. Electrodes are further modified by copper electroplating to prepare\ncatalysts for the electrochemical reduction of carbon dioxide. Scanning electron microscopy\nand energy dispersive X-ray analysis are used to inspect the surface morphology and chemical\ncomposition of obtained catalysts. Cyclovoltammetric investigations reveal that the copper\nelectroplating leads to the increase of electrode activity by three orders of magnitude.
Keywords:
3D printing; electrochemical reduction of carbon dioxide; electroplating
Available on request at various institutes of the ASCR
Electroplating of 3D Printed Electrodes for Selective Electrochemical Reduction of C02
In this work, computer assisted design and fused deposition modelling 3D printing are\nemployed to devise and manufacture electrodes from polylactic acid-carbon nanotube\nconductive composite. ...
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