Field experiments were conducted to explore the relationship between canopy apparent photosynthesis (F’N,can) ^nd grain yield of maize {Zea mays L.) and to determine over two years the effects of plant population density (PPD) on /'N.can- Yedan No. 4 hybrid (vertical leaf type) were grown at fíve PPD in 1989 and 1990. Measurements of /"n can were made throughout the growth period in a large plastic covered chamber put over a segment of the canopy. Maximum values of /^N.can ca. 1500 pmol(photon) m'^ s'* were about 2.8 mg(C02) m‘2(soil area) s'* at the anthesis stage and they decreased with age throughout grain filling. Differences in /^N can between PPD could be attributed to leaf area index (LAI) or radiant energy interception. There was a quadratic regression between and LAI. The critical LAI for Pn can was about 4 to 6 for Shendan No. 7 and Yendan 4, respectively. Grain yield also differed between PPD, the range was 850 to 1140 g m'^ in the two cultivars. Increasing PPD of Yedan No. 4 up to about 9 plants per m^ and decreasing PPD of Shendan No. 7 to about 4 plants per m^ in a non-stressed environment should increase grain yield. Pfj can anthesis was positively correlated with biological {r = 0.8750** to 0.9797**) and grain (r = 0.8932** to 0.9914**) yields.
Though the evidence of rapid variability in early-type stars is rather old, we have passed through the ignition stages of a more recent information explosion on this subject. This explosion started with introduction of new detectors capable to detect even very subtle variations. But the old evidence based on much important changes remains. Different types of rapid variability in 0, B, UR and CP2 stars and their relation are discussed.
The professional structure of the Romani ethnics developed in an uneven pace and in a regressive way. The traditional blacksmiths, horse-dealers, musicians or artists were outweighed by wage-workers , home-producers and unproductive persons with illegal sources of income. Because of this the experiences and usages passed over from one generation to another were disappearing. The only thing left was the coarse work force and even this was possible to be used casually and in season. Outside the summer months members of some families had to complement their incomes by begging, petty thefts and other forms of sponging.
Proliferation and migration of retinal endothelial cells (RECs) contribute to the development of diabetic retinopathy. PLAG1 (pleomorphic adenoma gene 1) functions as a zinc-finger transcription factor to participate in the development of lipoblastomas or pleomorphic adenomas of the salivary glands through regulation of cell proliferation and migration. The role of PLAG1 in diabetic retinopathy was investigated in this study. Firstly, RECs were induced under high glucose conditions, which caused reduction in viability and induction of apoptosis in the RECs. Indeed, PLAG1 was elevated in high glucosetreated RECs. Functional assays showed that silence of PLAG1 increased viability and suppressed apoptosis in high glucose-induced RECs, accompanied with up-regulation of Bcl-2 and down-regulation of Bax and cleaved caspase-3. Moreover, migration of RECs was promoted by high glucose conditions, while repressed by knockdown of PLAG1. High glucose also triggered angiogenesis of RECs through up-regulation of vascular endothelial growth factor (VEGF). However, interference of PLAG1 reduced VEGF expression to retard the angiogenesis. Silence of PLAG1 also attenuated high glucose-induced up-regulation of Wnt3a, β-catenin and c-Myc in RECs. Moreover, silence of PLAG1 ameliorated histopathological changes in the retina of STZ-induced diabetic rats through down-regulation of β-catenin. In conclusion, knockdown of PLAG1 suppressed high glucose-induced angiogenesis and migration of RECs, and attenuated diabetic retinopathy by inactivation of Wnt/ β-catenin signalling.