scholarly journals Publisher's Note: Role of adiabaticity in controlling alkali-metal fine-structure mixing induced by rare gases [Phys. Rev. A 95, 042708 (2017)]

2017 ◽  
Vol 95 (5) ◽  
Author(s):  
Ben Eshel ◽  
Joseph A. Cardoza ◽  
David E. Weeks ◽  
Glen P. Perram
2017 ◽  
Vol 95 (4) ◽  
Author(s):  
Ben Eshel ◽  
Joseph A. Cardoza ◽  
David E. Weeks ◽  
Glen P. Perram

Author(s):  
Alan N. Hodgson

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.


Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1013
Author(s):  
Stefanie Gärtner

Alkali metal thallides go back to the investigative works of Eduard Zintl about base metals in negative oxidation states. In 1932, he described the crystal structure of NaTl as the first representative for this class of compounds. Since then, a bunch of versatile crystal structures has been reported for thallium as electronegative element in intermetallic solid state compounds. For combinations of thallium with alkali metals as electropositive counterparts, a broad range of different unique structure types has been observed. Interestingly, various thallium substructures at the same or very similar valence electron concentration (VEC) are obtained. This in return emphasizes that the role of the alkali metals on structure formation goes far beyond ancillary filling atoms, which are present only due to charge balancing reasons. In this review, the alkali metals are in focus and the local surroundings of the latter are discussed in terms of their crystallographic sites in the corresponding crystal structures.


1990 ◽  
Vol 59 (3) ◽  
pp. 898-901 ◽  
Author(s):  
Atsushi Fukuroda ◽  
Nobuo Kobayashi ◽  
Yozaburo Kaneko

2004 ◽  
Vol 116 (28) ◽  
pp. 3814-3817 ◽  
Author(s):  
Anne Bleuzen ◽  
Virginie Escax ◽  
Alban Ferrier ◽  
Françoise Villain ◽  
Michel Verdaguer ◽  
...  

2021 ◽  
Author(s):  
jacky even ◽  
philippe tamarat ◽  
philipe bourges ◽  
guido roma ◽  
claudine katan ◽  
...  

1971 ◽  
Vol 9 (3) ◽  
pp. 581-601
Author(s):  
D. G. ROBINSON ◽  
R. D. PRESTON

Naked swarmers of both Cladophora rupestris and Chaetomorpha melagonium have been examined by the freeze-etching technique. The swarmers of Cladophora, collected just after settling, reveal several layers of granules external to the plasmalemma and internal to the so-called ‘fibrous-layer’. Chaetomorpha swarmers collected just before settling show extrusion of vesicles through the plasmalemma. The structures associated with the membranes are discussed in relation to known features of these swarmers already observed by sectioning. The role of granules in the synthesis of cell wall microfibrils is strengthened though the spatial arrangement of the granules seen in this investigation does not completely fulfil the ‘ordered granule’ hypothesis. Description of, and comments on, features related to cell wall synthesis, particularly the Golgi and vacuolar systems, are given.


Polyhedron ◽  
2011 ◽  
Vol 30 (2) ◽  
pp. 397-404 ◽  
Author(s):  
Eugenia Katsoulakou ◽  
Konstantis F. Konidaris ◽  
Aris Terzis ◽  
Catherine P. Raptopoulou ◽  
Spyros P. Perlepes ◽  
...  

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