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622. A coupled model of stomatal conductance and photosynthesis for winter wheat
- Creator:
- Ye, Z.-P. and Yu, Q.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- BWB model, irradiance, and Triticum
- Language:
- Multiple languages
- Description:
- The model couples stomatal conductance (gs) and net photosynthetic rate (PN) describing not only part of the curve up to and including saturation irradiance (Imax), but also the range above the saturation irradiance. Maximum stomatal conductance (gsmax) and Imax can be calculated by the coupled model. For winter wheat (Triticum aestivum) the fitted results showed that maximum PN (Pmax) at 600 µmol mol-1 was more than at 350 µmol mol-1 under the same leaf temperature, which can not be explained by the stomatal closure at high CO2 concentration because gsmax at 600 µmol mol-1 was less than at 350 µmol mol-1. The irradiance-response curves for winter wheat had similar tendency, e.g. at 25 °C and 350 µmol mol-1 both PN and gs almost synchronously reached the maximum values at about 1 600 µmol m-2 s-1. At 25 °C and 600 µmol mol-1 the Imax corresponding to Pmax and gsmax was 2 080 and 1 575 µmol m-2 s-1, respectively. and Z.-P. Ye, Q. Yu.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
623. A crazy century of memories
- Creator:
- Olšáková, Doubravka
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- English
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
624. A critique of the standard cosmological model
- Creator:
- Křížek , Michal and Somer, Lawrence
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Dark matter, dark energy, antigravity, modeling error, manifold, extrapolation, and cosmological parameters
- Language:
- English
- Description:
- According to the standard cosmological model, 27 % of the Universe consists of some mysterious dark matter, 68 % consists of even more mysterious dark energy, whereas only less than 5 % corresponds to baryonic matter composed from known elementary particles. The main purpose of this paper is to show that the proposed ratio 27 : 5 between the amount of dark matter and baryonic matter is considerably overestimated. Dark matter and partly also dark energy might result from inordinate extrapolations, since reality is identified with its mathematical model. Especially, we should not apply results that were verified on the scale of the Solar System during several hundreds of years to the whole Universe and extremely long time intervals without any bound of the modeling error.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
625. A curvature identity on a 6-dimensional Riemannian manifold and its applications
- Creator:
- Euh, Yunhee, Park, Jeong Hyeong, and Sekigawa, Kouei
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, Chern-Gauss-Bonnet theorem, curvature identity, locally harmonic manifold, 13, and 51
- Language:
- English
- Description:
- We derive a curvature identity that holds on any 6-dimensional Riemannian manifold, from the Chern-Gauss-Bonnet theorem for a 6-dimensional closed Riemannian manifold. Moreover, some applications of the curvature identity are given. We also define a generalization of harmonic manifolds to study the Lichnerowicz conjecture for a harmonic manifold "a harmonic manifold is locally symmetric" and provide another proof of the Lichnerowicz conjecture refined by Ledger for the 4-dimensional case under a slightly more general setting., Yunhee Euh, Jeong Hyeong Park, Kouei Sekigawa., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
626. A dampening effect of pulse interval variability on blood pressure variations with respect to primary variability in blood pressure during exercise
- Creator:
- Nataša Honzíková, Krtička, A., Nováková, Z., and Eva Závodná
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, srdeční rytmus, krevní tlak, tělesná cvičení, heart rate, blood pressure, exercises, baroreflex sensitivity, spectral analysis, heart rate variability, blood pressure variability, 14, and 612
- Language:
- English
- Description:
- The correlation between baroreflex sensitivity (BRS) and the spectrum component at a frequency of 0.1 Hz of pulse intervals (PI) and systolic blood pressure (SBP) was studied. SBP and PI of 51 subjects were recorded beat-to-beat at rest (3 min), during exercise (0.5 W/kg of body weight, 9 min), and at rest (6 min) after exercise. BRS was determined by a spectral method (a modified alpha index technique). The subjects were divided into groups according to the spectral amplitude of SBP at a frequency of 0.1 Hz. The following limits of amplitude (in mm Hg) were used: very high ≥ 5.4 (VH); high 5.4 > H ≥ 3 (H); medium 3 > M ≥ 2 (M), low < 2 (L). We analyzed the relationships between 0.1 Hz variability in PI and BRS at rest, during the exercise and during recovery in subgroups VH, H, M, L. The 0.1 Hz variability of PI increased significantly with increasing BRS in each of the groups with identical 0.1 Hz variability in SBP. This relationship was shifted to the lower values of PI variability at the same BRS with a decrease in SBP variability. The primary SBP variability increased during exercise. The interrelationship between the variability of SBP, PI and BRS was identical at rest and during exercise. A causal interrelationship between the 0.1 Hz variability of SBP and PI, and BRS was shown. During exercise, the increasing primary variability in SBP due to sympathetic activation was present, but it did not change the relationship between variability in pulse intervals and BRS., N. Honzíková, A. Krtička, Z. Nováková, E. Závodná., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
627. A Daniell integral approach to nonstandard Kurzweil-Henstock integral
- Creator:
- Bianconi, Ricardo, Prandini, João C., and Possani, Cláudio
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- math, Daniell integral, and Kurzweil-Henstock integral
- Language:
- English
- Description:
- A workable nonstandard definition of the Kurzweil-Henstock integral is given via a Daniell integral approach. This allows us to study the HL class of functions from . The theory is recovered together with a few new results.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
628. A data base for scaling up from the leaf to the canopy
- Creator:
- Pan, X., Hesketh, J. D., Huck, M. G., and Alm, D. M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Gossypium hirsutum, internode, leaf area index, node number, plant height, stem, and Zea mays
- Language:
- Multiple languages
- Description:
- A data base was generated for quantifying effects of thermal time (degree-days) on the appearance of new leaves, the expansion of such leaves to maximum area, their death, the appearance of new internodes below the node associated with such leaves, and the extension of these internodes to maximum length. The data base for a list of crop (agronomic and horticultural), weed, and native Tallgrass Prairie plants has been summarized, with equations for the above events as a function of degree days, with appropriate base temperatures and maximum cut-off temperatures, in a Java applet which is available at a website with the URL <http://th190-50.agn.uiuc.edu>. Associated graphical plots such as shown in this paper are also given. Branching behavior was accounted for. These events predict the effect of thermal time on leaf age and its height in the plant canopy, both important factors needed for upscaling functions for leaf behavior to those for behavior of the plant canopy. The data base is evolving to include coefficients for other species. Coefficients are used to predict the leaf area index of the canopy, which is important for predicting evapotranspiration from the crop and the protection of the soil from erosion. and X. Pan ... [et al,].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
629. A De Bruijn-Erdős theorem for $1$-$2$ metric spaces
- Creator:
- Chvátal, Vašek
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- line in metric space and De Bruijn-Erd\H os theorem
- Language:
- English
- Description:
- A special case of a combinatorial theorem of De Bruijn and Erdős asserts that every noncollinear set of $n$ points in the plane determines at least $n$ distinct lines. Chen and Chvátal suggested a possible generalization of this assertion in metric spaces with appropriately defined lines. We prove this generalization in all metric spaces where each nonzero distance equals $1$ or $2$.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
630. A description of two new species of coccidia (Apicomplexa: Eimeriidae) from African reptiles with nomenclatural corrections for two Caryospora and one Eimeria species from snakes
- Creator:
- Daszak, Peter and Ball, Stanley John
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Coccidia, Apicomplexa, Eimeriidae, Eimeria, Caryospora, Reptilia, Sauria, Serpentes, Gerrhosaurus, Chamaeleo, Dendroaspis, Python, and Psammophis
- Language:
- English
- Description:
- Two new species of coccidian parasites are described from African reptiles. Oocysts of Eimeria foulshami sp. n. from the plated lizard Gerrhosaurus major bottegoi Del Prato of Sudan are ellipsoidal, 24.1 × 14.9 (23-26.5 × 14-17.8) µm with a bilayered, colourless oocyst wall and lack polar granules. The ellipsoidal sporocysts average 8.6 × 4.6 (7-10.6 × 4.4-7) µm and possess a prominent, globular, sporocyst residuum. Oocysts of Caryospora regentensis sp. n. from the green mamba Dendroaspis viridis Hallowell of Kenya are spherical to subspherical, 16.8 × 16.4 (16-17.6 × 15-17.2) µm with a bilayered oocyst wall and a single polar granule. The ellipsoidal sporocysts average 13.0 × 10.3 (10.2-14 × 9.2-11) µm and possess a Stieda and substieda body and a prominent globular sporocyst residuum. Oocysts of Caryospora legeri Hoare, 1933 are reported from a hissing sand snake, Psammophis sibilans sibilans L. from Nigeria, representing a new geographical record. The oocysts are slightly larger than the type, but otherwise identical. Caryospora psammophi Bray, 1960 and C. hermae Bray, 1960 from Psammophis sibilans phillipsi, oocysts of which are morphologically similar to and overlap in dimensions with C. legeri Hoare, 1933, are synonymised with the latter species. Eimeria samiae Iskander et Tadros, 1979 is emended to E. samyadeli to reflect the gender of the person the species was named after and because E. sami is preoccupied. In addition to these findings, Eimeria bohemi Modrý, Šlapeta et Koudela, 2000 and oocysts of an unidentified spherical Eimeria sp. are reported from Chamaeleo dilepis dilepis Leach from Cameroon.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public