Two 10-μm interplanetary dust particles collected in the stratosphere, have been analyzed with X-ray fluorescence excited by white synchrotron radiation (SYXFA) at the HASYLAB (DESY) in Hamburg. The measured abundances of the minor and trace elements with 16 < Z < 76 are in good agreement with abundances determined by PIXE analysis [1] of the same particles.
The results demonstrate that SYXFA is indeed a powerful
non-destructive technique for multi-element analysis of
micron-sized samples. Moreover we find that the combined
application of two such techniques, SYXFA and PIXE, to the same valuable particle lends high credibility to the results.
Energy-dependent quenching of chlorophyll fluorescence and its reversion in intact isolated spinách chloroplasts were recorded at temperatures between 0 and 20 ®C. A temperature-dependence of Ihe quenching formation (and of quenching relaxation) corresponding to Qio values between 2 and 3 was found. Long-term cold acclimation of the plants resulted in a decrease of die fluorescence dechne half-time. The finál steady-state extent of quenching (q^) was not influenced by temperature shifts or cold acclimation.
To date, three species of Isospora Schneider, 1881 have been described from lizards of the genus Acanthodactylus Wiegmann. Two of these, although representing separate species parasitizing two different hosts, Acanthodactylus boskianus Daudin in Egypt and A. schmidti Haas in Saudi Arabia, were described under the name Isospora acanthodactyli. The third species is Isospora abdallahi Modrý, Koudela et Šlapeta, 1998 from A. boskianus in Egypt. In the present study, Isospora alyousifi nom. n. is proposed to accommodate Isospora acanthodactyli Alyousif et Al-Shawa, 1997 (homonym of I. acanthodactyli Sakran, Fayed, El-Toukhy et Abdel-Gawad, 1994) and its redescription based on newly collected material is provided.