scholarly journals Structural organization and tooth development in aHomoaff.erectusjuvenile mandible from the Early Pleistocene site of Garba IV at Melka Kunture, Ethiopian highlands

2016 ◽  
Vol 162 (3) ◽  
pp. 533-549 ◽  
Author(s):  
Clément Zanolli ◽  
M. Christopher Dean ◽  
Yared Assefa ◽  
Priscilla Bayle ◽  
José Braga ◽  
...  
Keyword(s):  
Structural Organization ◽  
Tooth Development ◽  
Early Pleistocene ◽  
Ethiopian Highlands

scholarly journals Inner structural organization of the mandibular corpus in the late Early Pleistocene human specimens Tighenif 1 and Tighenif 2

2019 ◽  
Vol 18 (8) ◽  
pp. 1073-1082 ◽  
Author(s):  
Lisa Genochio ◽  
Arnaud Mazurier ◽  
Jean Dumoncel ◽  
Charlotte E.G. Theye ◽  
Clément Zanolli
Keyword(s):  
Structural Organization ◽  
Early Pleistocene

Characterization and structural organization of the organic matrix of the radula teeth of the chiton Acanthopleura hirtosa

1990 ◽  
Vol 329 (1252) ◽  
pp. 87-96 ◽  
Keyword(s):  
Mechanical Properties ◽  
Structural Organization ◽  
Tooth Development ◽  
Discrete Distribution ◽  
Organic Matrix ◽  
High Magnification ◽  
Fibre Density ◽  
Anterior Section ◽  
Major Structural Component ◽  
The Matrix

The organic matrix of the radula teeth of the chiton Acanthopleura hirtosa has been examined by a variety of techniques to identify and partially characterize the major structural component and to elucidate the complex architectural arrangement of matrix fibres. The teeth are initially composed solely of organic material, a major component of which has been identified as the partially deacetylated α-polymorph of the polysaccharide, chitin. The matrix consists of organic fibres, with significant changes in the organization and distribution of fibres occurring in the early stages of tooth development, presumably in preparation for the onset of mineralization. Organic fibres in the posterior region of the tooth cusp become progressively more sparse and poorly ordered. In contrast, the anterior section of the cusp becomes more structured, consisting of a series of highly ordered rope-like fibres. At high magnification these fibres can be seen to consist of hollow tubules linked by fine strands or bridges. Demineralized mature teeth show the same variation in the fibre density and arrangement. It is suggested both that mineralization occurs on a preformed organic framework of which the fibrous bridges are an integral component and that the organization of the matrix fibres together with the architecturally discrete distribution of minerals contributes significantly to the overall mechanical properties of the tooth.

The expansion of the Acheulian to the Southeastern Ethiopian Highlands: Insights from the new early Pleistocene site-complex of Melka Wakena

2021 ◽  
Vol 253 ◽  
pp. 106763
Author(s):  
Erella Hovers ◽  
Tegenu Gossa ◽  
Asfawossen Asrat ◽  
Elizabeth M. Niespolo ◽  
Angesom Resom ◽  
...  
Keyword(s):  
Early Pleistocene ◽  
Ethiopian Highlands

scholarly journals A new cercopithecoid dentognathic specimen attributed to Theropithecus from the late Early Pleistocene (c. 1 Ma) deposits of Simbiro, at Melka Kunture, Ethiopian highlands

2015 ◽  
Vol 14 (8) ◽  
pp. 657-669 ◽  
Author(s):  
Amélie Beaudet ◽  
Clément Zanolli ◽  
Blade Engda Redae ◽  
Metasebia Endalamaw ◽  
José Braga ◽  
...  
Keyword(s):  
Early Pleistocene ◽  
Ethiopian Highlands

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Early Pleistocene (Calabrian) marine bottom oxygenation and palaeoclimate at the southern margin of the Central Anatolian Plateau

2018 ◽  
Vol 137 (3) ◽  
pp. 425-464 ◽  
Author(s):  
Nazik Öğretmen ◽  
Virgilio Frezza ◽  
Natália Hudáčková ◽  
Elsa Gliozzi ◽  
Paola Cipollari ◽  
...  
Keyword(s):  
Early Pleistocene ◽  
Anatolian Plateau ◽  
Southern Margin

RIBONUCLEOPROTEIN PARTICLES CONTAINING mRNA and pre-mRNA

1973 ◽  
Vol 74 (Suppl) ◽  
pp. S130-S167 ◽  
Author(s):  
O. P. Samarina ◽  
E. M. Lukanidin ◽  
G. P. Georgiev
Keyword(s):  
Structural Organization ◽  
General Scheme ◽  
Biological Significance ◽  
Mrna Transport ◽  
Ribonucleoprotein Particles ◽  
Mrna Precursor

ABSTRACT This paper is a review of the data concerning the nature, structural organization, properties and biological significance of the particles, containing mRNA and pre-mRNA (precursor of mRNA), i. e., (1) nuclear pre-mRNA-containing particles (2) free cytoplasmic mRNP (ribonucleoproteins), or informosomes (3) polysome-bound mRNP. Some new data on the comparison of nuclear and cytoplasmic particles, the nature of poly A-containing structures, involvement of informofers in Adenovirusspecific RNA transfer are presented. The general scheme of mRNA transport from nucleus to cytoplasm is discussed.

Sign in / Sign up

Export Citation Format

Share Document