Looking at Human Cytosolic Sialidase NEU2 Structural Features with an Interdisciplinary Approach

Biochemistry ◽  
2014 ◽  
Vol 53 (32) ◽  
pp. 5343-5355 ◽  
Author(s):  
Eugenio Monti ◽  
Giuliana Benaglia ◽  
Alessandra Mozzi ◽  
Paola Fusi ◽  
Giovanna Longhi ◽  
...  
Keyword(s):  
Interdisciplinary Approach ◽  
Structural Features ◽  
Cytosolic Sialidase

scholarly journals Hummingbird iridescence: an unsuspected structural diversity influences colouration at multiple scales

2019 ◽  
Author(s):  
Hugo Gruson ◽  
Marianne Elias ◽  
Christine Andraud ◽  
Chakib Djediat ◽  
Serge Berthier ◽  
...  
Keyword(s):  
Multiple Scales ◽  
Interdisciplinary Approach ◽  
Structural Diversity ◽  
Structural Features ◽  
Optical Systems ◽  
Evolutionary Transitions ◽  
Layer Width ◽  
Novel Approach ◽  
Single Colour ◽  
Angular Dependency

AbstractIridescent colours are colours that change depending on the angle of illumination or observation. They are produced when light is reflected by multilayer structures or diffracted by gratings. While this phenomenon is well understood for simple optical systems, it remains unclear how complex biological structures interact with light to produce iridescence. There are very few comparative studies at interspecific level (often focusing on a single colour patch for each species), resulting in an underestimation of structure diversity. Using an interdisciplinary approach combining physics and biology, we here quantify the colour and structure of 36 hummingbirds species evenly distributed across the phylogeny. We explore at least 2 patches per species, which are assumed to be under different selective regimes. For each patch, we measure structural features (number of layers, layer width, irregularity, spacing, etc.) of the feathers at different scales using both optical and electronic microscopy and we measure colour using a novel approach we developed to encompass the full complexity of iridescence, including its angular dependency. We discover an unsuspected diversity of structures producing iridescence in hummingbirds. We also study the effect of several structural features on the colour of the resulting signal, using both an empirical and modelling approach. Our findings demonstrate the need to take into account multiple patches per species and suggest possible evolutionary pressures causing the evolutionary transitions from one melanosome type to another.

scholarly journals Applying Close Range Non-Destructive Techniques for the Detection of Conservation Problems in Rock-Carved Cultural Heritage Sites

2021 ◽  
Vol 13 (5) ◽  
pp. 1040
Author(s):  
William Frodella ◽  
Mikheil Elashvili ◽  
Daniele Spizzichino ◽  
Giovanni Gigli ◽  
Akaki Nadaraia ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Interdisciplinary Approach ◽  
Integrated Approach ◽  
Structural Features ◽  
Slope Instability ◽  
Conservation Strategies ◽  
Weak Rocks ◽  
Heritage Sites ◽  
Mountainous Regions ◽  
Close Range

Rock-carved cultural heritage sites are often developed in slopes formed by weak rocks, which due to their peculiar lithological, geotechnical, and morpho-structural features are characterized by excellent carvability, which at the same time makes them prone to weathering, deterioration, and slope instability issues. In this context the use of advanced close-range nondestructive techniques, such as Infrared Thermography (IRT) and Unmanned Aerial vehicle-based Digital Photogrammetry (UAV-DP) can be profitably used for the rapid detection of conservation issues (e.g., open fractures, unstable ledges-niches, water seepage and moisture) that can lead to slope instability phenomena. These techniques, when combined with traditional methods (e.g., field surveys, laboratory analysis), can provide fundamental data (such as 3D maps of the kinematic mechanisms) to implement a site-specific and interdisciplinary approach for the sustainable protection and conservation of such fragile cultural heritage sites. In this paper some examples of conservation problems in several rupestrian sites characterized by different geological contexts, from the mountainous regions of Georgia to the ancient city of Petra in Jordan, are presented, with the aim of evaluating the potential of the proposed integrated approach. The final aim is to provide conservators, practitioners, and local authorities with a useful, versatile, and low-cost methodology, to be profitably used in the protection and conservation strategies of rock-carved sites.

scholarly journals Sevastopol in the Historical Memory of the Great Patriotic War: Media Space Analysis

2021 ◽  
Vol 30 (2) ◽  
pp. 3369-3379
Author(s):  
Olga Yarmak ◽  
Mariya Bolshakova ◽  
Anastasiya Maranchak ◽  
Zoya Savina
Keyword(s):  
Historical Memory ◽  
Interdisciplinary Approach ◽  
Structural Features ◽  
Information Flows ◽  
Media Communication ◽  
Information Spaces ◽  
The Social ◽  
Great Patriotic War ◽  
Media Monitoring ◽  
Great Victory

This article identifies the content and structural features of social and media communication of Runet users in relation to the information presence of Sevastopol in the construction of the historical memory of the Great Patriotic War. An interdisciplinary approach is used to fully implement the goal and objectives of the research being conducted. Media and information spaces cybermetry intrinsic to modern sociology make it possible to identify new trends in the formation of unconventional historical attitudes about the Great Victory, including the presence of Sevastopol in the historical memory of the Great Patriotic War. The use of the social media monitoring system "Medialogia" enabled an analysis of information flows about the Great Patriotic War and the role of Sevastopol in the Great Victory. The results of the study can contribute to the development of a guide aimed at intensifying the activities in the field of formation of the historical memory of the Great Victory. The authors believe that it will positively affect the consistent upholding of Russia's historical victories and their preservation in the modern digital space by shaping the agenda and managing information flows in the context of the ideological confrontation of the main world actors.

scholarly journals Applications of Stratigraphic Analysis to Enhance the Inspection and Structural Characterization of Historic Bridges

2021 ◽  
Vol 6 (1) ◽  
pp. 7
Author(s):  
Francesca Savini ◽  
Carlo Rainieri ◽  
Giovanni Fabbrocino ◽  
Ilaria Trizio
Keyword(s):  
Geographical Area ◽  
Central Italy ◽  
Interdisciplinary Approach ◽  
Integrated Approach ◽  
Structural Features ◽  
Existing Structures ◽  
3D Data ◽  
Bridge Structures ◽  
First Results ◽  
Landscape Value

Road networks are disseminated of bridge structures whose typology reflects the time of design and construction of the transportation infrastructure and its relevance in the reference geographical area. Among others, masonry bridges are still widely operational, especially in those regions affected by a limited urbanization and a very high landscape value. As a consequence, the maintenance and the reliability of existing structures is a key issue for owners and managers of road and railway infrastructures. This circumstance leads to the development of an integrated approach able to cover the needs of knowledge of the technological and structural features of the bridge along with its history and current conditions. The main contribution of the study lies in the implementation of such an interdisciplinary approach through the application of archaeological stratigraphic method and 3D data management to historical masonry bridges. The survey and inspection protocol, whose first results are here presented, aims to improve the knowledge of the assets, and facilitate the visual inspection. The results refer to a road infrastructure located along the Aterno River in the surroundings of L’Aquila (Central Italy) and point out promising perspectives in terms of feasibility and scalability of the approach to large stocks of assets.

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

Some Structural Features of Metaphase Chromosomes of Mice and Men

1967 ◽  
Vol 25 ◽  
pp. 190-191
Author(s):  
Godfrey C. Hoskins ◽  
Betty B. Hoskins
Keyword(s):  
Electron Microscopy ◽  
Electron Micrographs ◽  
Structural Features ◽  
Metaphase Chromosomes ◽  
The Future ◽  
Of Mice And Men ◽  
Mouse Cells ◽  
Human And Mouse

Metaphase chromosomes from human and mouse cells in vitro are isolated by micrurgy, fixed, and placed on grids for electron microscopy. Interpretations of electron micrographs by current methods indicate the following structural features.Chromosomal spindle fibrils about 200Å thick form fascicles about 600Å thick, wrapped by dense spiraling fibrils (DSF) less than 100Å thick as they near the kinomere. Such a fascicle joins the future daughter kinomere of each metaphase chromatid with those of adjacent non-homologous chromatids to either side. Thus, four fascicles (SF, 1-4) attach to each metaphase kinomere (K). It is thought that fascicles extend from the kinomere poleward, fray out to let chromosomal fibrils act as traction fibrils against polar fibrils, then regroup to join the adjacent kinomere.

Observations on the Structure of Ta2O5

1972 ◽  
Vol 30 ◽  
pp. 540-541
Author(s):  
P. S. Kotval ◽  
C. J. Dewit
Keyword(s):  
Electron Microscope ◽  
Structural Features ◽  
Amorphous Structure ◽  
Polished Surface ◽  
Distilled Water ◽  
Anodic Films ◽  
Amorphous Films ◽  
Beam Heating ◽  
Diffraction Patterns ◽  
Hexagonal Arrays

The structure of Ta2O5 has been described in the literature in several different crystallographic forms with varying unit cell lattice parameters. Earlier studies on films of Ta2O5 produced by anodization of tantalum have revealed structural features which are not consistent with the parameters of “bulk” Ta2O5 crystalsFilms of Ta2O5 were prepared by anodizing a well-polished surface of pure tantalum sheet. The anodic films were floated off in distilled water, collected on grids, dried and directly examined in the electron microscope. In all cases the films were found to exhibit diffraction patterns representative of an amorphous structure. Using beam heating in the electron microscope, recrystallization of the amorphous films can be accomplished as shown in Fig. 1. As suggested by earlier work, the recrystallized regions exhibit diffraction patterns which consist of hexagonal arrays of main spots together with subsidiary rows of super lattice spots which develop as recrystallization progresses (Figs. 2a and b).

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