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.

Characterization of a novel nuclear envelope protein restricted to certain cell types

1988 ◽  
Vol 90 (2) ◽  
pp. 237-245
Author(s):  
J.M. Lord ◽  
J.A. Thick ◽  
C.M. Bunce ◽  
A.M. Taylor ◽  
P.H. Gallimore ◽  
...  
Keyword(s):  
Nuclear Envelope ◽  
Envelope Protein ◽  
Cell Types ◽  
Integral Membrane Protein ◽  
Nuclear Pores ◽  
Cellular Processes ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

The monoclonal antibody AGF2.3 identifies a nuclear envelope protein that is restricted to certain cell types. In particular, this antigen shows a reduced level of expression during haemopoietic cell maturation. In this study, we have examined the relationship of this protein to known nuclear envelope proteins that have a similar molecular mass. Antigen extraction and immunoelectron microscope studies revealed that the AGF2.3 protein is an integral membrane protein present at both the inner and outer aspects of the nuclear envelope. The protein is not associated with nuclear pores and therefore is distinct from pore complex proteins. The AGF2.3 protein does not have ATPase activity. Therefore, this protein is also distinct from a myosin heavy chain-like ATPase that is associated with the nuclear envelope. The AGF2.3 antibody identifies a novel nuclear envelope protein. Further studies of the biochemical nature of the AGF2.3 protein should provide insight into novel cellular processes at the nuclear envelope relating to the lineage or maturation status of cells.

On Metaphysics and the Political: A Polemics of Reading Baudelaire in the 1930s

2019 ◽  
Vol 58 (2) ◽  
pp. 249-259
Author(s):  
Joseph Acquisto
Keyword(s):  
Twentieth Century ◽  
Political Crisis ◽  
The Political ◽  
Modern Poetry ◽  
Progressive Politics ◽  
The World ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

This essay examines a polemic between two Baudelaire critics of the 1930s, Jean Cassou and Benjamin Fondane, which centered on the relationship of poetry to progressive politics and metaphysics. I argue that a return to Baudelaire's poetry can yield insight into what seems like an impasse in Cassou and Fondane. Baudelaire provides the possibility of realigning metaphysics and politics so that poetry has the potential to become the space in which we can begin to think the two of them together, as opposed to seeing them in unresolvable tension. Or rather, the tension that Baudelaire animates between the two allows us a new way of thinking about the role of esthetics in moments of political crisis. We can in some ways see Baudelaire as responding, avant la lettre, to two of his early twentieth-century readers who correctly perceived his work as the space that breathes a new urgency into the questions of how modern poetry relates to the world from which it springs and in which it intervenes.

scholarly journals Common Phase and Structure Misidentifications in High-Resolution TEM Characterization of Perovskite Materials

2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Yu-Hao Deng
Keyword(s):  
High Resolution ◽  
Research Field ◽  
Structure Characterization ◽  
Phase Identification ◽  
Lead Iodide ◽  
Perovskite Materials ◽  
High Resolution Tem ◽  
Methylammonium Lead Iodide ◽  
Dose Imaging

High-resolution TEM (HRTEM) is a powerful tool for structure characterization. However, methylammonium lead iodide (MAPbI3) perovskite is highly sensitive to electron beams and easily decomposes into lead iodide (PbI2). Misidentifications, such as PbI2 being incorrectly labeled as perovskite, are widely present in HRTEM characterization and would negatively affect the development of perovskite research field. Here misidentifications in MAPbI3 perovskite are summarized, classified, and corrected based on low-dose imaging and electron diffraction (ED) simulations. Corresponding crystallographic parameters of intrinsic tetragonal MAPbI3 and the confusable hexagonal PbI2 are presented unambiguously. Finally, the method of proper phase identification and some strategies to control the radiation damage in HRTEM are provided. This warning paves the way to avoid future misinterpretations in HRTEM characterization of perovskite and other electron beam-sensitive materials.

The impact of tinnitus characteristics and associated variables on tinnitus-related handicap

2015 ◽  
Vol 130 (1) ◽  
pp. 25-31 ◽  
Author(s):  
S Degeest ◽  
P Corthals ◽  
I Dhooge ◽  
H Keppler
Keyword(s):  
Additional Insight ◽  
Tinnitus Handicap Inventory ◽  
Hearing Status ◽  
Questionnaire Score ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship ◽  
Sample Case ◽  
Insight Into ◽  
Associated Variables

AbstractObjective:This study aimed to determine the characteristics of tinnitus and tinnitus-related variables and explore their possible relationship with tinnitus-related handicap.Methods:Eighty-one patients with chronic tinnitus were included. The study protocol measured hearing status, tinnitus pitch, loudness, maskability and loudness discomfort levels. All patients filled in the Tinnitus Sample Case History Questionnaire, the Hyperacusis Questionnaire and the Tinnitus Handicap Inventory. The relationship of each variable with the Tinnitus Handicap Inventory score was evaluated by univariate and multivariate analyses.Results:Five univariables were associated with the Tinnitus Handicap Inventory score: loudness discomfort level, subjective tinnitus loudness, tinnitus awareness, noise intolerance and Hyperacusis Questionnaire score. Multiple regression analysis showed that the Hyperacusis Questionnaire score and tinnitus awareness were independently associated with the Tinnitus Handicap Inventory score.Conclusion:Hyperacusis and tinnitus awareness were independently associated with the Tinnitus Handicap Inventory score. Questionnaires on tinnitus and hyperacusis are especially suited to providing additional insight into tinnitus-related handicap and are therefore useful for evaluating tinnitus patients.

Structural Characterization of Epitaxial GMR Magnetic Multilayers and Spin Valves Grown by Sputter Deposition

2000 ◽  
Vol 614 ◽  
Author(s):  
H. Geng ◽  
R. Loloee ◽  
J.W. Heckman ◽  
J. Bass ◽  
W.P. Pratt ◽  
...  
Keyword(s):  
High Resolution ◽  
Epitaxial Growth ◽  
Magnetic Multilayers ◽  
Sputter Deposition ◽  
Dc Magnetron Sputtering ◽  
Cu Films ◽  
Electron Backscatter ◽  
High Resolution Tem ◽  
Fcc Structure

ABSTRACTEpitaxial Cu/Py/FeMn and (Cu/Co)×20 GMR magnetic multilayers were grown on single crystal (011) Nb that was deposited on (1121) Al2O3 substrates by dc magnetron sputtering. Electron backscatter patterns (EBSPs) revealed that the Cu films display two twin variants, corresponding to two stacking sequences of {111} planes in fcc. The epitaxial orientation relationship between the bcc Nb and both fcc Cu variants was the Nishiyama-Wasserman (N-W) relationship. Conventional TEM observations revealed epitaxial growth for both the Cu/Py/FeMn and (Cu/Co)×20 multilayers. High-resolution TEM confirmed epitaxial growth of close packed (011) Nb on (1120) Al2O3 substrates with [111]Nb∥[0001]Al2O3. Numerous small twins were observed in the Cu near the Cu-Nb interface of the Cu/Py/FeMn multilayer. In the Cu/Co multilayer, the growth planes of the Cu and Co were found to be {100} instead of the expected close-packed {111} planes of the fcc structure.

scholarly journals Non-negative sparse Laplacian regularized latent multi-view subspace clustering

2021 ◽  
Vol 15 ◽  
pp. 174830262110249
Author(s):  
Cong-Zhe You ◽  
Zhen-Qiu Shu ◽  
Hong-Hui Fan
Keyword(s):  
Subspace Clustering ◽  
Structural Features ◽  
Space Representation ◽  
Graph Regularization ◽  
Structure Information ◽  
Cluster Data ◽  
Latent Space ◽  
Low Dimensional ◽  
Relationship Of ◽  
The Relationship

Recently, in the area of artificial intelligence and machine learning, subspace clustering of multi-view data is a research hotspot. The goal is to divide data samples from different sources into different groups. We proposed a new subspace clustering method for multi-view data which termed as Non-negative Sparse Laplacian regularized Latent Multi-view Subspace Clustering (NSL2MSC) in this paper. The method proposed in this paper learns the latent space representation of multi view data samples, and performs the data reconstruction on the latent space. The algorithm can cluster data in the latent representation space and use the relationship of different views. However, the traditional representation-based method does not consider the non-linear geometry inside the data, and may lose the local and similar information between the data in the learning process. By using the graph regularization method, we can not only capture the global low dimensional structural features of data, but also fully capture the nonlinear geometric structure information of data. The experimental results show that the proposed method is effective and its performance is better than most of the existing alternatives.

scholarly journals TARGETED ADVERTISING IN THE BREAKFAST CEREAL INDUSTRY

2017 ◽  
Vol 49 (3) ◽  
pp. 382-399 ◽  
Author(s):  
JOSHUA BERNING ◽  
ADAM N. RABINOWITZ
Keyword(s):  
Product Differentiation ◽  
Food Product ◽  
Television Advertising ◽  
Breakfast Cereal ◽  
Data Set ◽  
Policy Makers ◽  
Relationship Of ◽  
Cereal Industry ◽  
The Relationship ◽  
Insight Into

AbstractWe examine the relationship of product characteristics of ready-to-eat breakfast cereal and targeted television advertising to specific consumer segments. We compile a unique data set that includes brand-packaging characteristics, including on-box games, nutrition information, and cobranding. We find that the relationship of television advertising and a cereal's brand-packaging characteristics varies by target audience. Our results provide insight into understanding how manufacturers strategically utilize branding, packaging, and television advertising. This can help industry and policy makers develop food product advertising policy. This analysis extends to other product markets where extensive product differentiation and promotion are present as well.

scholarly journals Structure and function of factor XI

Blood ◽  
2010 ◽  
Vol 115 (13) ◽  
pp. 2569-2577 ◽  
Author(s):  
Jonas Emsley ◽  
Paul A. McEwan ◽  
David Gailani
Keyword(s):  
Catalytic Domain ◽  
Structural Features ◽  
Factor Ix ◽  
Missense Mutations ◽  
Factor Xi ◽  
Disk Structure ◽  
Ligand Binding Sites ◽  
And Function ◽  
Insight Into

AbstractFactor XI (FXI) is the zymogen of an enzyme (FXIa) that contributes to hemostasis by activating factor IX. Although bleeding associated with FXI deficiency is relatively mild, there has been resurgence of interest in FXI because of studies indicating it makes contributions to thrombosis and other processes associated with dysregulated coagulation. FXI is an unusual dimeric protease, with structural features that distinguish it from vitamin K–dependent coagulation proteases. The recent availability of crystal structures for zymogen FXI and the FXIa catalytic domain have enhanced our understanding of structure-function relationships for this molecule. FXI contains 4 “apple domains” that form a disk structure with extensive interfaces at the base of the catalytic domain. The characterization of the apple disk structure, and its relationship to the catalytic domain, have provided new insight into the mechanism of FXI activation, the interaction of FXIa with the substrate factor IX, and the binding of FXI to platelets. Analyses of missense mutations associated with FXI deficiency have provided additional clues to localization of ligand-binding sites on the protein surface. Together, these data will facilitate efforts to understand the physiology and pathology of this unusual protease, and development of therapeutics to treat thrombotic disorders.

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