To investigate damaging mechanisms of chilling and salt stress to peanut (Arachis hypogaea L.) leaves, LuHua 14 was used in the present work upon exposure to chilling temperature (4°C) accompanied by high irradiance (1,200 μmol m-2 s-1) (CH), salt stress accompanied by high irradiance (1,200 μmol m-2 s-1) (SH), and high-irradiance stress (1,200 μmol m-2 s-1) at room temperature (25°C) (NH), respectively. Additionally, plants under low irradiance (100 μmol m-2 s-1) at room temperature (25°C) were used as control plants (CK). Relative to CK and NH treatments, both the maximal photochemical efficiency of PSII (Fv/Fm) and the absorbance at 820 nm decreased greatly in peanut leaves under CH and SH stress, which indicated that severe photoinhibition occurred in peanut leaves under such conditions. Initial fluorescence (F0), 1 - qP and nonphotochemical quenching (NPQ) in peanut leaves significantly increased under CH- and SH stress. Additionally, the activity of superoxide dismutase (SOD), one of the key enzymes of water-water cycle, decreased greatly, the accumulation of malondialdehyde (MDA) and membrane permeability increased. These results suggested that damages to peanut photosystems might be related to the accumulation of reactive oxygen species (ROS) induced by excess energy, and the water-water cycle could not dissipate energy efficiently under the stress of CH and SH, which caused the accumulation of ROS greatly. CH and SH had similar damaging effects on peanut photosystems, except that CH has more severe effects. All the results showed that CH- and SH stress has similar damaging site and mechanisms in peanut leaves. and L.-Q. Qin ... [et al.].
Henneguya pilosa sp. n., a new species of myxosporean from the gill filaments of the white piranha, Serrasalmus altuvei Ramirez, 1965 (Characidae), a freshwater teleost fish collected in the Zoological Garden of the city of Teresina (Piauí), Brazil, is described from light and transmission electron microscope observations. This myxosporean produced small plasmodia (up to 0.2 mm in diameter), each one containing all life-cycle stages of the parasite, including numerous spores. The spores, laterally compressed, averaged 54.2 (52.3-56.0) µm in total length and consisted of two unequal valves adhering together along the suture line and two caudal processes. The spore body measured 21.1 (20.0-23.1) µm in length, 5.9 (5.5-6.3) µm in width, and 2.2 (1.9-2.6) µm in thickness. The two equal ellipsoidal polar capsules of 7.4 (7.1-7.6) µm long and 1.2 (1.0-1.3) µm wide possessed a polar filament with 11-12 (rarely 13) turns. All surfaces of the spores were covered with a tightly adherent complex network of numerous densely ramified granulo-fibrillar masses, the longest measuring 1.5 µm long, observed around the caudal processes. The prevalence of infection was 30%. The taxonomic affinities of this parasite with other of the same genus in freshwater South American fish species are discussed.
Four myxosporean species were found on the gills of Ictiobus bubalus from Illinois (USA). Myxobolus endovasus (Davis, 1947) Grinham et Cone, 1990 is revised. Three new species are recorded. Myxobolus enoblei sp. n. has spores ovoid in frontal view, 14.3 x 13 pm in size. Myxobolus morrisonae sp. n. has spores subcircular in frontal view, 10 x 9.5 pm in size; the surface of shell valves appears hairy when studied by SEM. Triangula illinoisensis sp. n. has spores rounded semicircular in frontal view, 10.2 x 12.8 pm in size. Triangula illinoisensis is the fourth species of its genus to be described from fishes.
Photography started to be applied in sciences shortly after the announcement of the daguerreotype in 1839 and become one of the most important supporting disciplines for science. This review concentrates on the history of scientific research on photographing processes which was conducted at Charles University. The most important was development of sensitometry which started by work of Vojtěch Šafařík (1829-1902) who thoroughly studied the dry proces. Photographic work in the Institute of Physics (IP) of the Czech part of "Carlo-Ferdinand University" was initiated due to studies of X-rays (from 1895) and later the Institute of Photochemistry and Scientific Photography was founded within IP by Professor Viktorin Vojtěch (1879-1948). In 1950-s this institute disappear and splitted into chemical part (colloidal chemistry and photochemistry) at Faculty of Natural Sciences and physical part (photophysics, studies of latent image and silver halogenides) at Faculty of Mathematics and Physics under leadership of Professor Ladislav Zachoval (1906-1982). His follower Professor Karel Vacek then turned interest from scientific photography into modern subjects of chemical physics and biophysics., Jan Valenta., and Obsahuje bibliografii
In the paper we obtain several characteristics of pre-T2 of strongly preirresolute topological vector spaces and show that the extreme point of a convex subset of a strongly preirresolute topological vector space X lies on the boundary.
To fulfill the requirements on the laser ranging systems, the soft/hardware package of the Helwan station was significantly modified in period 1982-84. The max. ranging reprate was increased up to 5 pps. The mount pointing accuracy was increased implementing the mechanical inaccuracies software model. The automatical comparison of the time base to the Loran C signal was put into operation.
The author analyzes the influence of the EU enlargement on women's and feminist NGOs and women's groups in the Czech Republic. She identifies main proceeding changes in non-governmental sphere and civic mobilization which are analyzed as consequences of Czech Republic's accession to the EU. Namely she discuss processes of professionalization - hence establishment of professional women's and feminist NGOs and development of political lobby; processes of developing of project-orientation - it reflects the necessity to apply for grants largely in EU to finance operation of organizations. Finally she identifies processes of acceptation of reform-orientation of women's NGOs in the Czech Republic - which means orientation on mainstream issues that are encouraged by EU policies. As a result of these changes some small and marginal NGOs disappeared and others were determined to make strategic partnership across the thematic focus.