scholarly journals The role of second coordination-sphere interactions in incommensurately modulated structures, using β-K5Yb(MoO4)4 as an example

2005 ◽  
Vol 61 (4) ◽  
pp. 400-406 ◽  
Author(s):  
Alla Arakcheeva ◽  
Gervais Chapuis ◽  
Vâclav Petricek ◽  
Vladimir Morozov
Keyword(s):  
Coordination Sphere ◽  
Driving Force ◽  
The Other ◽  
Structure Model ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
The Third ◽  
Modulated Structures ◽  
Coordination Spheres

The incommensurate palmierite-like structure of β-K5Yb(MoO4)4, potassium ytterbium tetramolydate, has been refined in the (3 + 1)-dimensional monoclinic superspace group X2/m(0ρ0)00, with X = [0 0 0 0; ½ ½ 0 0; 0 0 ½ ½; ½ ½ ½ ½] and the unit-cell parameters a = 10.4054 (16), b = 6.1157 (12), c = 19.7751 (18) Å, β = 136.625 (10)°; q = 0.6354 (30)b*. The occupations of the K and Yb atomic positions are described by crenel functions. The structure model reveals a balanced interaction between the atoms of the first and second coordination spheres. It is shown that the third coordination sphere should not be neglected in studies of modulated structures. The ordering of the K and Yb atoms appears to be the driving force for the modulation of all the other atoms.

Three Dimensional Structure of UMo8O26: Ordering of U-Vacancies

2002 ◽  
Vol 718 ◽  
Author(s):  
N.D. Zakharov ◽  
P. Werner
Keyword(s):  
Low Temperatures ◽  
Driving Force ◽  
Three Dimensional ◽  
Solid State Reaction Method ◽  
Dimensional Structure ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Edx Microanalysis

AbstractThe structure and composition of UMo8O26 synthesized by solid state reaction method have been investigated by High Resolution Transmission Electron Microscopy (HRTEM), Selected Area Electron Diffraction, and EDX microanalysis. The ordering of U vacancies results in considerable enlargement of unit cell parameters: an=6.44 nm, bn=1.45 nm, cn=1.6 nm. It is build up of four layers piled up in c direction. Each following layer is shifted relative to previous one by vector bn/4. Eight hexagonal tunnels in each layer are filled by U atoms, while the eight others are vacant (V). Interaction between U cations and vacancies is driving force for ordering. The variation of stoichiometry can be a reason for appearance of incommensurate modulations in these crystals. It seems plausible that this structure might also exhibit superconductivity at low temperatures.

Role of pro-opiomelanocortin-derived peptides in the regulation of steroid production by human fetal adrenal cells in culture

1983 ◽  
Vol 97 (3) ◽  
pp. 357-367 ◽  
Author(s):  
Andrew Baird ◽  
K. W. Kan ◽  
Samuel Solomon
Keyword(s):  
Peptide Hormones ◽  
The Other ◽  
Dehydroepiandrosterone Sulphate ◽  
Steroid Production ◽  
Adrenal Cells ◽  
The Third ◽  
Cells In Culture

Synthetic (1–39)ACTH, (1–24)ACTH, (18–39)ACTH, α-MSH, met-enkephalin and α-, βand γ-endorphin were tested for their ability to stimulate steroidogenesis by human fetal adrenal cells in culture. Adrenal cells were incubated with peptide hormones for two periods of 24 h. On the third day of the experiment the cells were incubated with progesterone (4 μg/2 ml) for 8 h. At the doses tested only (1–39)ACTH, (1–24)ACTH and α-MSH stimulated steroidogenesis. None of the other peptides had any corticotrophic effect on the formation of cortisol, corticosterone or dehydroepiandrosterone sulphate (DHAS). At the highest doses tested, α-MSH (100 μg/2 ml) had a corticotrophic effect that was not different from that obtained with 20 ng (1–39)ACTH or (1–24)ACTH. At the lower doses (0·2–2 μg/2 ml), α-MSH stimulated the formation of DHAS (P<0·01) without stimulating the formation of cortisol.

Inspiratory elevation of the ribs in the dog: primary role of the parasternals [published errata appear in J Appl Physiol 1991 Aug;71(2):following Table of Contents and 1991 Dec;71(6):following Author Index]

1991 ◽  
Vol 70 (4) ◽  
pp. 1447-1455 ◽  
Author(s):  
A. De Troyer
Keyword(s):  
Quantitative Analysis ◽  
Axial Displacement ◽  
The Other ◽  
Primary Role ◽  
Intercostal Muscles ◽  
The Third ◽  
Inspiratory Activity ◽  
Fourth Rib

To assess the relative contributions of the different groups of inspiratory intercostal muscles to the cranial motion of the ribs in the dog, we have measured the axial displacement of the fourth rib and recorded the electromyograms of the parasternal intercostal, external intercostal, and levator costae in the third interspace in 15 anesthetized animals breathing at rest. In eight animals, the parasternal intercostals were denervated in interspaces 1-5. This procedure caused a marked increase in the amount of external intercostal and levator costae inspiratory activity, and yet the inspiratory cranial motion of the rib was reduced by 55%. On the other hand, the external intercostals in interspaces 1-5 were sectioned in seven animals, and the reduction in the cranial rib motion was only 22%; the amount of parasternal and levator costae activity, however, was unchanged. When the parasternals in these animals were subsequently denervated, the levator costae inspiratory activity increased markedly, but the inspiratory cranial motion of the rib was abolished or reversed into an inspiratory caudal motion. These studies thus confirm that, in the dog breathing at rest, the parasternal intercostals have a larger role than the external intercostals and levator costae in causing the cranial motion of the ribs during inspiration. A quantitative analysis suggests that the parasternal contribution is approximately 80%.

Monoclinic-to-orthorhombic phase transition in Cu2(AsO4)(OH) olivenite at high temperature: strain and mode decomposition analyses

2018 ◽  
Vol 82 (2) ◽  
pp. 347-365 ◽  
Author(s):  
Serena C. Tarantino ◽  
Michele Zema ◽  
Athos M. Callegari ◽  
Massimo Boiocchi ◽  
Michael A. Carpenter
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Single Crystal ◽  
Volume Expansion ◽  
Monoclinic Phase ◽  
Orthorhombic Phase ◽  
Unit Cell ◽  
The Other ◽  
Unit Cell Parameters ◽  
Cell Parameters

ABSTRACTA natural olivenite single crystal was submitted to in situ high-temperature single-crystal X-ray diffraction from room temperature (RT) to 500°C. Unit-cell parameters were measured at regular intervals of 25°C, and complete datasets collected at T = 25, 50, 100, 150, 200, 250, 300, 400 and 500°C. Evolution of unit-cell parameters and structure refinements indicates that olivenite undergoes a structural phase transition from P21/n to Pnnm at ~200°C, and eventually becomes isostructural with the other members of the olivenite-mineral group. Volume expansion with temperature is larger in the monoclinic phase – where it follows a non-linear trend – than in the orthorhombic one. Axial and volume expansion coefficients of the orthorhombic olivenite phase are positive and linear and similar to those of the other Cu-bearing member of the mineral family, namely libethenite, but rather different from those of the Zn-analogue arsenate adamite.Distortion of Cu polyhedra is quite high in the olivenite monoclinic phase at RT and goes towards a relative regularization with increasing T until the phase transition occurs. In the orthorhombic phase, no significant variation of the polyhedral distortion parameters is observed with increasing temperature, and maximum expansion is along the b direction and governed by corner-sharing. Landau potential provides a good representation of the macroscopic changes associated with the phase transition, coupling between the strains and the order parameter is responsible for the nearly tricritical character of the transition.

scholarly journals Association between spectator and other roles in school bullying

2016 ◽  
Vol 26 (3) ◽  
pp. 352
Author(s):  
Marcela Almeida Zequinão ◽  
Pâmella De Medeiros ◽  
Beatriz Pereira ◽  
Fernando Luiz Cardoso
Keyword(s):  
Public Schools ◽  
Negative Reinforcement ◽  
Strong Association ◽  
School Bullying ◽  
The Other ◽  
Seventh Grade ◽  
Santa Catarina ◽  
The Third ◽  
Aggressive Behaviours

Introduction: The school bullying is characterized by repetitiveness of aggression and the intentionality to injure or cause suffering to others. The bystanders to this phenomenon tend to be mainly responsible for the course that bullying will take and its results. Objective: To analyse the association between the role of bystander with the other possible roles played in bullying. Method: A total of 409 children from the third to seventh grade participated in this study, with an average age of 11 years (SD = 1.61), enrolled in two municipal public schools in Florianópolis, Santa Catarina, Brazil. The instruments used were: one of the scales of the Questionnaire for the Study of Violence Among Peers, to identify bystanders, and the Olweus Questionnaire, to describe the possible roles played in school bullying. Results: It was found that most of the participants assumed the role of bystander in school bullying. However, an association was found with regard to gender and being a bystander. Also, strong association was found between being a bystander and the other roles played in bullying, primarily in relation to the bullies. Conclusion: These results reinforce the importance of bystanders in these aggressions, not only because they represent most of the participants, but mainly because of the positive or negative reinforcement they can offer in these aggressive behaviours. Therefore, the incentive and the encouragement of these students to denounce the aggressors, as well as defending the victims is essential to reduce school bullying.

scholarly journals Детерминизм локального атомного упорядочения в монослоях золота в формировании их электронной структуры

2022 ◽  
Vol 64 (3) ◽  
pp. 303
Author(s):  
В.Л. Карбовский ◽  
А.А. Романский ◽  
Л.И. Карбовская ◽  
В.В. Стонис
Keyword(s):  
Coordination Sphere ◽  
Electronic States ◽  
Mutual Arrangement ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
The Third ◽  
Long Range Interactions ◽  
Valence Bands ◽  
D Orbitals

The total and partial densities of electronic states of gold monolayer structures of different symmetry are calculated by the quantum mechanical calculations methods in the DFT approximation. It is shown that the first coordination sphere is determinant in the formation of the fine structure and the extent of the valence bands of the monolayer gold structures under study. The peaks splitting of the TDOS curve, which leads to its finer structure, is influenced not only by the lengths of interatomic bonds but also by the mutual arrangement of atoms. The influence of long-range interactions on the electronic structure of gold monolayers has been established. For example, for the (110) plane, a change in the atomic ordering in the third coordination sphere as a result of the introduction of a vacancy leads to noticeable changes in the TDOS curve, which indicates either a significant role of the atoms of the third coordination sphere or a significant redistribution of the interaction of d-orbitals of different symmetries of close neighbours. A correlation between the packing density, as well as the number of neighbours in the first coordination sphere, and the width of the energy band of gold monolayers has been established.

Socio-Cognitive Model of Trust

2009 ◽  
pp. 2316-2323
Author(s):  
Rino Falcone ◽  
Cristiano Castelfranchi
Keyword(s):  
Decision Making ◽  
Cognitive Model ◽  
Frame Of Reference ◽  
The Other ◽  
The Internet ◽  
The Third ◽  
Interaction Traces ◽  
Cooperative Models ◽  
Support Decision Making

Humans have learned to cooperate in many ways and in many environments, on different tasks, and for achieving different and several goals. Collaboration and cooperation in their more general sense (and, in particular, negotiation, exchange, help, delegation, adoption, and so on) are important characteristics - or better, the most foundational aspects - of human societies (Tuomela, 1995). In the evolution of cooperative models, a fundamental role has been played by diverse constructs of various kinds (purely interactional, technical-legal, organizational, socio-cognitive, etc.), opportunely introduced (or spontaneously emerged) to support decision making in collaborative situations. The new scenarios we are destined to meet in the third millennium transfigure the old frame of reference, in that we have to consider new channels and infrastructures (i.e., the Internet), new artificial entities for cooperating with artificial or software agents, and new modalities of interaction (suggested/imposed by both the new channels and the new entities). In fact, it is changing the identification of the potential partners, the perception of the other agents, the space-temporal context in which interaction happen, the nature of the interaction traces, the kind and role of the authorities and guarantees, etc. For coping with these scenarios, it will be necessary to update the traditional supporting decision-making constructs. This effort will be necessary especially to develop the new cybersocieties in such a way as not to miss some of the important cooperative characteristics that are so relevant in human societies.

scholarly journals Purification, crystallization and preliminary crystallographic analysis of DR0248, an MNT–HEPN fused protein fromDeinococcus radiodurans

2015 ◽  
Vol 71 (1) ◽  
pp. 49-53
Author(s):  
Gaelle Pesce ◽  
Simone Pellegrino ◽  
Sean McSweeney ◽  
AnaMaria Goncalves ◽  
Daniele de Sanctis
Keyword(s):  
Deinococcus Radiodurans ◽  
Crystallographic Analysis ◽  
Unit Cell ◽  
Nucleotide Binding Domain ◽  
Unit Cell Parameters ◽  
Dodecyldimethylamine Oxide ◽  
Space Group ◽  
Cell Parameters ◽  
Nucleotidyl Transferase

DR0248 is a protein identified in theDeinococcus radiodurans(DR) genome that is predicted to encompass two domains: an N-terminal minimal nucleotidyl transferase domain (MNT) and a C-terminal higher eukaryotes and prokaryotes nucleotide-binding domain (HEPN). These two domains, usually encoded in two ORFs, have been suggested to play the role of a toxin–antitoxin (TA) system in prokaryotes. Recombinant DR0248 was overexpressed and purified fromEscherichia coliand diffraction-quality crystals were obtained in the presence of the detergent molecules dodecyldimethylamine oxide (DDAO) and octaethylene glycol monododecyl ether (C12E8), which were used as crystallization additives. Crystals grown with DDAO diffracted to a resolution of 2.24 Å and belonged to space groupC2221, with unit-cell parametersa= 98.4,b= 129.9,c= 59.2 Å. Crystals grown with C12E8 diffracted to a resolution of 1.83 Å and belonged to space groupP212121, with unit-cell parametersa= 51.6,b= 87.2,c= 108.2 Å. The structure was solved by multiwavelength anomalous dispersion from zinc bound to the protein using a single crystal obtained in the presence of DDAO.

scholarly journals Intertextuality of Political Discourse in Germany (on the Example of “Political Ash Wedfnesday”)

2020 ◽  
pp. 76-90
Author(s):  
Maria A. Elizarieva ◽  
Marina A. Chigasheva ◽  
Boris Blahak ◽  
Maria Yu. Mikhina
Keyword(s):  
Literary Work ◽  
The Other ◽  
The Political ◽  
Ordinary People ◽  
Television Commercial ◽  
The Third ◽  
Christian Social Union ◽  
The One ◽  
The Relationship

The article is devoted to the role of intertext in public speeches of politicians of the Christian Social Union in Bavaria within the framework of the “political ash Wednesday”. On the example of the speeches of M. Söder, A. Scheuer and M. Blume in 2018, the relationship between the type of intertext and its pretext, on the one hand, and the speaker’s intention, on the other, was analyzed. As a result of the analysis of 23 intertextual inclusions, four intentions were revealed, among which (48 %) criticism of political opponents (SDPG, “The Greens”, AfD, “Free Voters”) prevails. Quotes from representatives of these parties, political slogans, a paraphrase of the name of the eco-movement and a quote from an artist are used to express it. As the intertextual analysis showed, to verbalize the second intention (appeal to authoritative opinion and emphasize the continuity of the party course), the former chairman of the CSU F. J. Strauss is cited, while the third intention (opposing Bavaria to the rest of Germany) is implemented using a quote from the Bavarian anthem, a paraphrase of a television commercial and quotations from a literary work. In addition, the authors found that the fourth intention (emphasizing the dialogic nature of communication with ordinary people) is found only in M. Söder’s speech in the form of a retelling of his dialogues with ordinary citizens.

scholarly journals Polymorphism and pseudosymmetry of 10,10′-oxybis(9-thia-10-hydro-10-boraanthracene)

2019 ◽  
Vol 75 (5) ◽  
pp. 690-694
Author(s):  
Julian Radtke ◽  
Hans-Wolfram Lerner ◽  
Michael Bolte
Keyword(s):  
Title Compound ◽  
The Other ◽  
Asymmetric Unit ◽  
Compound I ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Compound C ◽  
Centrosymmetric Space Group ◽  
Compound Ii

We have encountered two polymorphs of the title compound, C24H16B2OS2, both of which display almost the same unit-cell parameters. Compound (I) crystallizes in the non-centrosymmetric space group P21 with four molecules in the asymmetric unit. These molecules are related by pseudosymmetry. As a result, the space group looks like P21/c, but the structure cannot be refined successfully in that space group. Compound (II) on the other hand crystallizes in the centrosymmetric space group P21/c with only two molecules in the asymmetric unit. The crystals studied for (I) and (II) were both non-merohedral twins.

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