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72. Evoluce tolerance
- Creator:
- Natália Martínková
- Format:
- print, bez média, and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, plísně, netopýři, biology, molds (Fungi), bats, 2, and 57/59
- Language:
- Czech
- Description:
- Czech White-Nose Syndrome Team together with international collaborators discovered mechanisms of tolerance that protect Palearctic bats from white-nose syndrome (WNS), the disease that caused mass die-off in North America. The discovery raises hope for a better future of bats in North American ecosystems. White-nose syndrome (WNS) is caused by a generalist pathogen Pseudogymnoascus destructans with the worst possible characteristics of an infectious fungal agent. The generalist nature of the WNS fungus means that it can infect any bat hibernating in a contaminated cave or mine and, moreover, it may remain viable and virulent, waiting for its hosts until the next hibernation period. Harmless to humans, the WNS fungus kills hibernating North American bats in winter. However, loss of voracious insectivorous bats from agricultural ecosystems may result in economic costs required for increased pest control. Without mass die-offs of bats harbouring the WNS agent in Europe, the response to disease is an enigma. To study the survival crossroads, the Czech WNS Team focused on the relationship between pathogen quantity and disease under natural conditions. High disease prevalence together with high fungal loads in absence of bat population declines in Eurasia indicates disease tolerance mechanisms, where hosts limit harm inflicted by the pathogen but do not hinder its growth. The tolerance mechanisms revealed by the Czech WNS Team is a function of bat adaptation to the presence of the pathogen. and Natália Martínková.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
73. Fylogeneze a vzájemné vztahy určují nejpřirozenější systém živočichů
- Creator:
- Jitka Vilímová
- Format:
- print, bez média, and svazek
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, fylogeneze, živočichové, phylogeny, animals, 2, and 57/59
- Language:
- Czech
- Description:
- Jitka Vilímová.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
74. Fylogeneze živočichů: ohlédnutí roku 2015
- Creator:
- Jan Zrzavý
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, fylogeneze živočichů, mnohobuněční, biology, animal phylogeny, Metazoa, molekulární fylogenetika, fylogenetická metodika, molekulární fylogeneze, fylogenetický přístup, 2, and 57/59
- Language:
- Czech
- Description:
- Článek přináší přehled současných znalostí o fylogenezi mnohobuněčných živočichů, tak jak vycházejí ze současného fylogenomického výzkumu. Zvláštní pozornost je věnována skupinám s konfliktním postavením (Ctenophora, Xenacoelomorpha, Bryozoa) a skupinám, o jejichž postavení dosud nevíme téměř nic (Dendrogramma, Dicyemida, Orthonectida)., We present an overview of current knowledge on the phylogeny of multicellular animals, based on current phylogenomic research. This overview pays special attention to groups with uncertain positions (Ctenophora, Xenacoelomorpha, Bryozoa) and groups whose position is still largely unknown (Dendrogramma, Dicyemida, Orthonectida)., and Jan Zrzavý.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
75. Growth and photosynthetic responses of four landscape shrub species to elevated ozone
- Creator:
- Zhang, L., Su, B. Y., Xu, H., and Li, Y. G.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- biologie, biology, biomass, Chionanthus retusus Lindl.& Paxt, chlorophyll a fluorescence, Cornus alba, Euonymus bungeanus, gas exchange, ozone, Photinia x fraseri, 2, and 57/59
- Language:
- Multiple languages
- Description:
- a1_Attention should be paid to ozone (O3) sensitivity of greening plant since ground-level O3 concentrations are increasing especially in urban and suburban area. We studied the ecophysiological responses to elevated O3 of four shrub species [Euonymus bungeanus Maxim. (EB), Photinia × fraseri (PF), Chionanthus retusus Lindl. & Paxt. (CR) and Cornus alba L. (CA)], which are often used for garden greening in China. Saplings of those species were exposed to high O3 concentration (70 nmol mol-1, 7 h d-1 for 65 d) in open-top growth chambers. Responses to O3 were assessed by gas exchanges, chlorophyll (Chl) fluorescence and dry mass. We found that elevated O3 significantly decreased lightsaturated net photosynthetic rate (PNsat), transpiration rate (E) and stomatal conductance (gs). The ratio of intercellular CO2 to ambient CO2 concentration (Ci/Ca) did not reduce under O3 fumigation which suggested that the O3-induced depressions of P Nsat under O3 fumigation were probably due to limitation of mesophyll processes rather than stomatal limitation. High O3 exposure also significantly depressed the maximum efficiency of photosystem II (PSII) photochemistry in the dark-adapted state (Fv/Fm) which meant the O3-induced photoinhibition. Both root dry mass and root/shoot ratios were significantly decreased under ozone fumigation, but the total mass was unchanged. The responses of gas exchange such as PNsat in these four shrubs to O3 exposure were species-specific. Highest loss of PNsat was observed in EB (-49.6%), while the CR had the lowest loss (-36.5%). Moreover, the O3-exposed CR showed similar gs as CF, reflecting that its O3 flux might be unchanged under elevated O3 environment. Ozone drastically decreased actual quantum yield of PSII (ΦPSII) and electron transport rate (ETR) in EB while increased ΦPSII and ETR in CR., a2_Furthermore, the relative losses in P Nsat positively correlated with the relative decreases in ΦPSII and ETR which indicated that the impairment of photosynthesis was probably affected by the light reaction process. The light reaction of EB was impaired most seriously but that of CR was not damaged. All results indicated that EB was probably the most sensitive shrub species to O3 while CR the most tolerant one. Therefore, CR might be an ideal choice for greening in ozone-polluted areas., L. Zhang ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
76. Growth and physiological changes in saplings of Minquartia guianensis and Swietenia macrophylla during acclimation to full sunlight
- Creator:
- Azevedo, G. F. C. and Marenco, R. A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- biologie, biology, gas exchange, growth rates, photoinhibition, photosynthsis, Rubisco activity, tropical trees, 2, and 57/59
- Language:
- Multiple languages
- Description:
- a1_Low light availability under a forest canopy often limits plant growth; however, sudden increase in light intensity may induce photoinhibition of photosynthesis. The aim of this study was to evaluate the ecophysiological changes that occur in potted plants of Minquartia guianensis and Swietenia macrophylla during the acclimation process to full sunlight. We used six full-sun independent acclimation periods (30, 60, 90, 120, 150, and 180 days) and a control kept in the shade. Shading was obtained by placing plants under the canopy of a small forest. The Fv/Fm ratio, net photosynthetic rate (PN), the maximum carboxylation velocity of Rubisco (Vcmax), maximum electron transport rate (Jmax), specific leaf area (SLA), and growth were assessed at the end of each of the six acclimation periods. Plant exposure to full sunlight caused a sudden decrease in the Fv/Fm ratio (photoinhibition) particularly in Minquartia. Photooxidation (necrotic patches) of the leaf tissue was observed in upper leaves of Minquartia. The higher PN values were observed in Swietenia under full sun, about 12 μmol(CO2) m-2 s-1. Vcmax25 values were higher after 90 days of acclimation, about 14 μmol(CO2) m-2 s-1 for Minquartia, and 35 μmol(CO2) m-2 s-1 for Swietenia. At the end of a 180-d acclimation period Jmax25 was 35 μmol(electron) m-2 s-1 for Minquartia and 60 μmol(electron) m-2 s-1 for Swietenia. SLA was higher in Swietenia than in Minquartia. In Minquartia, monthly rate of leaf production per plant (MRLP) was positive (0.22 leaf month-1) after four months in the open. Whereas, in Swietenia MRLP was positive (0.56 leaf month-1) after an acclimation period of two months. After six months in the open, height growth rates were 3.5 and 28 mm month-1 for Minquartia and Swietenia, respectively., a2_The greater acclimation capacity of Swietenia was associated to an enhanced photosynthetic plasticity under full sun. In Minquartia, transition to full-sun conditions and lack of physiological adjustment resulted in severe photoinhibition and loss of leaves., G. F. C. Azevedo, R. A. Marenco., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
77. Guyanské pobřežní ekosystémy
- Creator:
- Jozef Májsky
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biologické vědy, pobřežní rostlinná společenstva, pobřežní živočišná společenstva, pobřeží, pobřežní biotopy, ekosystémy, tropické ekosystémy, chráněná území, coastal plant communities, coastal animal communities, sea coast, coastal biotopes, ecosystems, tropical ecosystems, protected areas, Guyana, 2, and 57/59
- Language:
- Czech
- Description:
- Autor čerpá ze své návštěvy pobřežního pásu Francouzské Guyany a Surinamu, především několika tamních chráněných území, v r. 2008, a představuje charakteristické ekosystémy na pobřeží této části Latinské Ameriky. Jde o mangrovy, nížinné zaplavované lesy, močály a vlhké savany, i mělké laguny a suchomilná společenstva na písčitém pobřeží. Na základě pozorování a literatury jsou uvedeny typické nebo něčím zvláštní druhy zdejší flóry i fauny. Za zmínku stojí např. pozorování ohrožených mořských želv kladoucích vejce, včetně kožatky obrovské (Dermochelys coriacea)., The author presents the characteristic coastal ecosystems of French Guyana and Surinam (based on his visit to this coastal area, especially to several protected areas located there, in 2008). The ecosystems include mangroves, lowland flooded forests, swamps and wet savannas, as well as shallow lagoons and xeric communities on the sand coast. Based on observations and literature survey, the article mentions typical or remarkable species of the local fauna and flora. For example, it is worth mentioning observation of threatened sea turtles laying eggs, including the Leatherback Sea Turtle (Dermochelys coriacea)., and Jozef Májsky.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
78. Had číslo 54 žije
- Creator:
- Janoušek, Karel
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, užovka stromová, ohrožené druhy živočichů, biology, Elaphe longissima, endangered animals, Poohří (Česko), Zamenis longissimus, 2, and 57/59
- Language:
- Czech
- Description:
- Užovka stromová (Zamenis longissimus) patří mezi kriticky ohrožené druhy naší fauny. V České republice se průkazně vyskytuje pouze ve třech oblastech, přičemž nejzranitelnější je populace v údolí řeky Ohře v západních Čechách, izolovaná stovky kilometrů od souvislého areálu druhu. V letech 2005-07 jsme v Poohří provedli systematický výzkum hadů pod záštitou Fakulty životního prostředí České zemědělské univerzity v Praze a Agentury ochrany přírody a krajiny ČR. Jedinci užovky stromové byli po odchycení změřeni, zváženi, označeni pomocí zástřihů na břišních štítcích (odebrané části štítků posloužily pro analýzu DNA) a detailně vyfotografováni se zaměřením na individuální charakter ošupení (folidózu) hlavy. Na základě zpětných odchytů pak byla odhadována početnost zdejší populace. Během tříletého sledování jsme takto označili a zdokumentovali celkem 432 exemplářů užovky stromové. Jeden ze současných projektů záchranného programu pro užovku stromovou zahrnuje i další odhad početnosti spojený s individuálním značením. Tato aktivita se opakuje zhruba po 10 letech a cílem je zaznamenat změny v početnosti jedinců. V dubnu 2015 se podařilo opětovně odchytit samce označeného v prvním výzkumu pod pořadovým číslem 54. Během výzkumů jsme ho chytili 10x (5x v r. 2005, 2x v r. 2006, 2x v r. 2007 a 1x v r. 2015). To umožnilo zodpovězení i nastolení různých otázek souvisejících např. s věkem a rychlostí růstu., The Aesculapian snake (Zamenis longissimus) is a critically endangered species of Czech fauna. In the Czech Republic it demonstrably occurs in three areas. Its population is most vulnerable in the Ohře river valley in western Bohemia, systematic research into which is presented here. During our three-year research we determined and documented the size and weight of 432 Aesculapian snakes, as well as performing DNA analysis and taking photographs of the individual nature of the scaliness involved. An estimate was made of population figures based on repeated captures., and Karel Janoušek, Radka Musilová, Vít Zavadil.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
79. Helena Illnerová: Čas pro světlo. Rozhovor s Pavlem Kovářem
- Creator:
- Rudolf Zahradník
- Format:
- bez média and svazek
- Type:
- article, text, recenze, recensions, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, biology, 2, and 57/59
- Language:
- Czech
- Description:
- [autor recenze] Rudolf Zahradník.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
80. Herbářovaná šedesátka: položka Echium alias Hadinec Jiří
- Creator:
- Pavel Kovář, Lustyk, Pavel, Petr Sklenář, and Michal Štefánek
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biologické vědy, Hadinec, Jiří, 1955-, Univerzita Karlova., Přírodovědecká fakulta, herbáře, botanika, výročí, botanici, herbaria, botany, anniversaries, botanics, 2, and 57/59
- Language:
- Czech
- Description:
- Pavel Kovář, Pavel Lustyk, Petr Sklenář, Michal Štefánek.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public