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32802. Water - source of life but also its threat: two views upon water, two motifs of science and research activities in the Institute of Hydrology, Slovak Academy of Sciences (IH SAS) during past fifty years
- Creator:
- Sútor, Július
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Slovak
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32803. Water as symbol: transformation and/or re-birth in the Indian anglophone novel
- Creator:
- Volná, Ludmila
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Water, symbol, and Indian anglophone
- Language:
- English
- Description:
- This article deals with the Hindu cosmological imagery of water as presented in the Indian novel in English. The writers show a great interest in water as a means of depicting a transformation and/or re-birth of both the Indian society and the individuals in it relying on the water as symbolizing a beginning of a new life/identity in the Hindu cosmology. This is rendered vividly, for example, through the Nārada and Mārkandeya myths, where the two sages, after a passage through water, experience a new identity or a world perception totally different from that known to them before. R. K. Narayan, an author who lived all his life in India, deals in his novel The English Teacher with the spiritual transformation of the main character, Krishnan, which is accompanied and accomplished by different entities of water. He is oppressed both by the colonial condition and by personal tragedy, whereas Saleem, the main character of Salman Rushdie’s Midnight’s Children, who is made to represent the country, acquires in the jungle of the Sundarbans an understanding of the necessity of adopting elements of other cultures. Two other authors, Anita Desai and Chitra Banerjee Divakaruni, develop the theme of the woman’s condition as a representation of the counterpart and contradictory images of water and sun/fire. Desai’s Fasting, Feasting relates the Indian condition to that of another culture and Divakaruni’s The Mistress of Spices addresses the problems of the Indian concept of marriage in the diaspora while using mythological imageries of other cultures.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
32804. Water flow in a single fracture with variable aperture
- Creator:
- Veselý, Marek and Mls, Jiří
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- fracture flow, variable aperture, percolation probability, contact area, puklinové proudění, proměnlivé rozevření, perkolační pravděpodobnost, and kontaktní plocha
- Language:
- Slovak
- Description:
- Water flow in a single fracture with variable aperture was studied by means of numerical modeling. For this purpose, two numerical models were developed. Computer simulations of water flow rates, fracture contact areas and transmissivities for fractal and nonfractal fractures were performed. Water flow rates were approximated by a trend function. The effect of the grid size upon the stability of results as well as the dependence of the fracture transmissivity on rate of contact area were studied. The achieved results were compared with measured data. and Studie se věnuje proudění podzemní vody v samostatné puklině metodou numerického modelování. K tomu účelu jsme vyvinuli dva numerické modely. Byly provedeny série numerických simulací proudění vody a výpočtu kontaktní plochy a transmisivity pukliny pro obecný typ pukliny. Byly studovány vliv velikosti sítě generované pukliny na stabilitu perkolačních charakteristik a závislost propustnosti pukliny na poměrné velikosti kontaktní plochy. Získané výsledky byly vyhodnocovány ve vztahu ke známým experimentálním datům.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32805. Water relations and gas exchange in Coespeletia moritziana (Sch. Bip) Cuatrec., a giant rosette species of the high tropical Andes
- Creator:
- Rada, F., Azócar, A., and Rojas-Altuve, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, net photosynthetic rate, osmotic adjustment, plant growth stages, stomatal conductance, tropical mountains, 2, and 58
- Language:
- Multiple languages
- Description:
- Giant rosettes are ones of the most striking features of the vegetation in the high tropical Andes, with Coespeletia moritziana reaching the highest altitudes up to 4,600 m a.s.l. Different from other giant rosettes, this species grows on rock outcrops with poorly developed soils and where water availability may be limited. Two questions are addressed in this study: How does this species respond in terms of water relations to maintain favorable gas-exchange conditions? Considering that adult plants rely on a water-reserving central pith, how do early stages respond to this environment’s extreme conditions? Water relations and gas-exchange studies were carried out on juveniles, intermediate and adult C. moritziana plants during wet and dry seasons in Páramo de Piedras Blancas at 4,200 m a.s.l. Adult plants maintained higher leaf water potentials (ΨL) during the wet season, however, no differences between stages were found for the dry season. Minimum dry season ΨL were never near the turgor loss point in any of the stages. Juveniles show a more strict stomatal control during the dry season to maintain a favorable water status. Net photosynthesis significantly decreased in intermediate and juvenile stages from wet to dry seasons. Our results suggest that C. moritziana resists more extreme conditions compared to other Andean giant rosettes., F. Rada, A. Azócar, A. Rojas-Altuve., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32806. Water relations and leaf anatomy of the tropical species, Jatropha gossypifolia and Alternanthera crucis, grown under an elevated CO2 concentration
- Creator:
- Rengifo, E., Urich, R., and Herrera, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- drought, parenchyma, open-top chamber, osmotic potential, pressure potential, stomatal density, volumetric elasticity modulus, water potential, and water supply
- Language:
- Multiple languages
- Description:
- In order to address the question of how elevated CO2 concentration (EC) will affect the water relations and leaf anatomy of tropical species, plants of Jatropha gossypifolia L. and Alternanthera crucis (Moq.) Bondingh were grown in five EC open top chambers (677 μmol mol-1) and five ambient CO2 concentration (AC) open top chambers (454 μmol mol-1) with seasonal drought. No effect of EC was found on morning xylem water potential, leaf osmotic potential, and pressure potential of plants of J. gossypifolia. In A. crucis EC caused a significant increase in morning xylem water potential of watered plants, a decrease in osmotic potential, and an increase of 24-79 % in pressure potential of moderately droughted plants. This ameliorated the effects of drought. Stomatal characteristics of both leaf surfaces of J. gossypifolia and A. crucis showed time-dependent, but not [CO2]-dependent changes. In J. gossypifolia the thickness of whole leaf, palisade parenchyma, and spongy parenchyma, and the proportion of whole leaf thickness contributed by these parenchymata decreased significantly in response to EC. In A. crucis EC caused an increase in thickness of whole leaf, bundle sheath, and mesophyll, while the proportion of leaf cross-section comprised by the parenchymata remained unchanged. These effects disappeared with time under treatment, suggesting that acclimation of the leaf anatomy to the chambers and to EC took place in the successive flushes of leaves produced during the experiment. and E. Rengifo, R. Urich, A. Herrera.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32807. Water relations, chlorophyll a fluorescence, and contents of saccharides in tree species of a tropical forest in response to flood
- Creator:
- Rengifo, E., Tezara, W., and Herrera, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Acosmium nitens, Campsiandra laurifolia, Eschweilera tenuifolia, net photosynthetic rate, Psidium ovatifolium, soluble sugars, starch, stomatal conductance, and Symmeria paniculata
- Language:
- Multiple languages
- Description:
- We studied the seasonal changes in water relations, chlorophyll a fluorescence, and leaf saccharide contents of the tropical flood-tolerant trees Acosmium nitens, Campsiandra laurifolia, Eschweilera tenuifolia, Symmeria paniculata, and Psidium ovatifolium. Xylem water potential increased with flooding to a larger extent than leaf sap osmotic potential in all the species, and soluble sugars contributed up to 66 % of osmotic potential at maximum flooding. Starch was accumulated in leaves. Maximum quantum yield of photosystem 2 decreased in emerged leaves, values being always higher than 0.76. Daily maximum net photosynthetic rate and leaf conductance decreased in all the species. This reduction was associated in all the species but S. paniculata with the absence of a compensatory increase in non-photochemical quenching. and E. Rengifo, W. Tezara, A. Herrera.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32808. Water relations, gas exchange, photochemical efficiency, and peroxidative stress of four plant species in the Heihe drainage basin of northern China
- Creator:
- Gong, J. R., Zhao, A. F., Huang, Y. M., Zhang, X. S., and Zhang, C. L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- active oxygen, antioxidative ability, desert plants, drought stress, mesophytic plants, photochemical efficiency, photosynthesis, stomatal conductance, transpiration rate, and water use efficiency
- Language:
- Multiple languages
- Description:
- Haloxylon ammodendron, Calligonum mongolicum, Elaeagnus angustifolia, and Populus hosiensis had different adaptations to limited water availability, high temperature, and high irradiance. C. mongolicum used water more efficiently than did the other species. Because of low transpiration rate (E) and low water potential, H. ammodendron had low water loss suitable for desert conditions. Water use efficiency (WUE) was high in E. angustifolia, but high E and larger leaf area made this species more suitable for mesic habitats; consequently, this species is important in tree shelterbelts. P. hosiensis had low WUE, E, and photosynthesis rates, and therefore, does not prosper in arid areas without irrigation. High irradiances caused photoinhibition of the four plants. The decrease of photochemical efficiency was a possible non-stomata factor for the midday depression of C. mongolicum. However, the species exhibited different protective mechanisms against high irradiance under drought stress. H. ammodendron and C. mongolicum possessed a more effective antioxidant defence system than E. angustifolia. These three species showed different means of coping with oxidative stress. Hence an enzymatic balance is maintained in these plants under adverse stress conditions, and the concerted action of both enzymatic and non-enzymatic reactive oxygen species scavenging mechanisms is vital to survive adverse conditions. and J. R. Gong ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32809. Water stable aggregates of Japanese Andisol as affected by hydrophobicity and drying temperature
- Creator:
- Leelamanie, D.A.L. and Karube, Jutaro
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- aggregate stability, contact angle, floating time, Japanese Andisol, hydrophobicity, and wetting rate
- Language:
- Slovak
- Description:
- Hydrophobicity is a property of soils that reduces their affinity for water, which may help impeding the pressure build-up within aggregates, and reducing aggregate disruption. The purpose of this study was to examine the relation of soil hydrophobicity and drying temperature to water stability of aggregates while preventing the floating of dry aggregates using unhydrophobized and hydrophobized surface Andisol. Soil was hydrophobized using stearic acid into different hydrophobicities. Hydrophobicity was determined using sessile drop contact angle and water drop penetration time (WDPT). Water stability of aggregates (%WSA) was determined using artificially prepared model aggregates. The %WSA increased as the contact angle and WDPT increased. Contact angle and WDPT, which provided maximum %WSA showing less than 1 s of floating, was around 100° and 5 s, respectively. Although the %WSA gradually increased with increasing contact angle and WDPT above this level, high levels of hydrophobicity initiated aggregate floating, which would cause undesirable effects of water repellency. Heating at 50°C for 5 h d-1 significantly affected %WSA and hydrophobicity in hydrophobized samples, but did not in unhydrophobized samples. The results indicate that the contact angle and wetting rate (WDPT) are closely related with the water stability of aggregates. The results further confirm that high levels of hydrophobicities induce aggregate floating, and the drying temperature has differential effects on hydrophobicity and aggregate stability depending on the hydrophobic materials present in the soil.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
32810. Water stress and abscisic acid treatments induce the CAM pathway in the epiphytic fern Vittaria lineata (L.) Smith
- Creator:
- Minardi, B. D., Voytena, A. P. L., Santos, M., and Randi, Á. M.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, pigmenty, photosynthesis, pigments, Brazílie, Brasil, chlorophyll fluorescence, malate, morphoanatomy, photosynthetic pathway, Vittaria lineata, 2, and 581
- Language:
- Multiple languages
- Description:
- Among various epiphytic ferns found in the Brazilian Atlantic Forest, we studied Vittaria lineata (L.) Smith (Polypodiopsida, Pteridaceae). Anatomical characterization of the leaf was carried out by light microscopy, fluorescence microscopy, and scanning electron microscopy. V. lineata possesses succulent leaves with two longitudinal furrows on the abaxial surface. We observed abundant stomata inside the furrows, glandular trichomes, paraphises, and sporangia. We examined malate concentrations in leaves, relative water content (RWC), photosynthetic pigments, and chlorophyll (Chl) a fluorescence in control, water-deficient, and abscisic acid (ABA)-treated plants. Plants subjected to drought stress (DS) and treated by exogenous ABA showed significant increase in the malate concentration, demonstrating nocturnal acidification. These findings suggest that V. lineata could change its mode of carbon fixation from C3 to the CAM pathway in response to drought. No significant changes in RWC were observed among treatments. Moreover, although plants subjected to stress treatments showed a significant decline in the contents of Chl a and b, the concentrations of carotenoids were stable. Photosynthetic parameters obtained from rapid light curves showed a significant decrease after DS and ABA treatments., B. D. Minardi, A. P. L. Voytena, M. Santos, Á. M. Randi., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public