A new species of caligid copepod (Siphonostomatoida), Anuretes grandis sp. п., parasitic on the painted sweetlips [Diagrammapictum (Thunberg)] in Taiwan is described. The new species is distinguished from its congeners by having: (1) free margin of céphalothorax not covering fourth pediger, (2) large genital complex longer than 2/3 of the cephalic shield, (3) no maxillary whip, (4) leg 3 with 9 setae on the terminal segment of exopod and 8 plumose setae on the terminal segment of endopod, and (5) armature of I,III on leg 4 exopod. Genus Anuretes Heller, 1865 is reviewed and redefined. Based on the new diagnosis three species (A. chelatus Prahha et Pillai, A. fedderni Price and A. parvulus Wilson) were transferred to Pseudanureles, and two species (A.furcatus Capart and A. renalis Ileegaard) were transferred to Lepeophtheirus. In addition, the following three species of caligids were transferred to Anuretes: Lepeophtheirus fallolunulus Lewis, Heniochophilus indicus Pillai, and Lepeophtheirus rotundigenitalis Prabha et Pillai. The latter is renamed Anuretes occullus nom. n. due to the homonym encountered through this transfer. “Anuretes plectorhynchi Yamaguti” reported by Prabha and Pillai (1986) is renamed Anuretes similis sp. n. and Anuretes yamagutii Prabha et Pillai is relegated to the synonym of Anuretes anomalus Pillai. A key to the 18 species of Anuretes is provided.
Energy transfer from resynthesized protochlorophyllide (PChlide) to chlorophyll (Chl) appeared after 5 h irradiation and additional redarkening of etiolated barley leaves. The transfer was more effective after a longer greening. Benzyladenine (BA) removed delay at the onset of the energy transfer and this process was effective even at very low Chl contents. BA enhanced Chl accumulation more strongly than the development of photosystems. The balance between the rate of Chl synthesis and that of its efflux from PChlide-containing site may determine the number of Chl molecules near PChlide, and thereby the probability of the energy transfer. At a high rate of Chl synthesis a part of its molecules remained near the PChlide synthesis site. Under various conditions of irradiation the slower rate of Chl accumulation corresponded to the more efficient energy transfer. Chl accumulation at PChlide forming site probably Controls the activity of the multienzyme systém of Chl biosynthesis by a feedback mechanism. The BA addition increased the number of EF-mtramembrane particles and the munber of enzyme systems of Chl biosynthesis to the same extent.
Genetic distances and phylogenetic clustering are calculated for sympatric populations of Rhipicephalus pusillus (Gil Collado) 1939 ticks, using cuticular hydrocarbon analysis and several statistical tools (stepwise discriminant analysis, Nei’s genetic distance using different sets of compounds, and Cavalli-Sforza’s Brownian motion model). Discriminant analysis on genic frequencies permits the detection of the most ancient geographic relationships between the populations, while the genetic distance method determines current evolutive affinities. However, methods based on quantitative estimation provide a poor resolution. Genetic distances are very high in the populations studied, suggesting a strong reproductive isolation of the specimens involved.
Properties and functional activity of the photosynthetic apparatus in Vida faba L. plants grown at 10, 50, 100 and 150 W PAR were studied. Responses of the photosynthetic apparatus in high, HI (125 W m-^) and low irradiance, LI (10 W m-2) plants to a change in irradiance (/) depended on the leaf age. The chlorophyll (a + b) content per unit of the leaf area remained relatively constant during the first 3 d after a shift in /. Acclimation of the photosynthetic electron transport activity to I depended on / in the preceding period and on the phase of leaf development.
Prestel introduced a generalization of the notion of an ordering of a field, which is called a semiordering. Prestel’s axioms for a semiordered field differ from the usual (Artin-Schreier) postulates in requiring only the closedness of the domain of positivity under $x \rightarrow x a^2$ for nonzero $a$, instead of requiring that positive elements have a positive product. In this work, this type of ordering is studied in the case of a division ring. It is shown that it actually behaves the same as in the commutative case. Further, it is shown that the bounded subring associated with that ordering is a valuation ring which is preserved under conjugation, so one can associate a natural valuation to a semiordering.
The appearance of isolated sunspot groups as well as clustering in large active regions depends upon a complex dynamo process. Evidence of this dynamo process may be deduced from three different outstanding studies. a) The emergence of new fluxes (spots or flares) is preceded by local cyclonic motions, observed at
the photospheric level. In regions of weak magnetic fields ; for example polarity inversion lines, gaps between magnetic "hills" or borders of the facula. This velocity structure is a response with a short scale in time and space to local subphotospheric perturbation and thus creates currents and new magnetic flux. b) Magnetic tracers such as long lived H filaments and sunspots, show that the regions of emergence of new flux (family of sunspot groups, eruptive sites or parasitic polaritics) are related to the existence of limited areas rotating rigidly. These "pivot points" which do not follow dlffcrential rotation, could be anchored more deeply than the active centers themselves. c) A large scale circulation, tied to the global rotation, reflects the motions of the underlying
fluid (frozen field). Recent results show the existence of azimuthal rolls which transport upward the deep magnetic field. They move slowly toward the poles, and they appear to govern the cyclicity
and to modulate the observed solar rotation. These observational results need to be considered to understand the production and the development of active regions.
Photoinhibition is a significant constraint for improvement of radiation-use efficiency and yield potential in cereal crops. In this work, attached fully expanded leaves of seedlings were used to assay the factors determining photoinhibition and for evaluation of tolerance to photoinhibition in wheat (Triticum aestivum L.). Our results showed that even 1 h under PPFD of 600 µmol(photon) m-2 s-1 could significantly reduce maximal quantum yield of PSII photochemistry (Fv/Fm) and performance index (PI) compared to low light [300 µmol(photon) m-2 s-1]. The decrease of Fv/Fm and PI was more noticeable with the increase of light intensity; irradiance higher than 800 µmol(photon) m-2 s-1 resulted in photoinhibition. Compared to 25°C, lower (20°C) or higher temperature (≥ 35°C) aggravated photoinhibition, while slightly high temperature (28°) alleviated photoinhibition. At 25°C, irradiance of 1,000 µmol(photon) m-2 s-1 for 1 h was enough to cause photoinhibition and a significant decrease of Fv/Fm, PI, trapped energy flux, electron transport flux, and density of reaction center as well as increase of dissipated energy flux per cross section were observed. In addition, seedlings at 21-32 days after planting showed a relatively stable phenotype, while the younger or older seedlings indicated an increased susceptibility to photoinhibition, especially in senescing leaves. Finally, six wheat varieties with relative tolerance to photoinhibition were identified from 22 Chinese winter wheat varieties by exposing attached leaves of the 25-d old seedlings for 1 h to 1,000 µmol(photon) m-2 s-1 at 25°C. Therefore, our work established a possible method for development of new wheat varieties with enhanced tolerance to photoinhibition., H. Li, Q. Zheng, J. Zhang, B. Li, Z. Li., and Obsahuje bibliografii