scholarly journals Mechanism of translocation: relative arrangement of tRNA and mRNA on the ribosome.

1980 ◽  
Vol 77 (9) ◽  
pp. 5110-5114 ◽  
Author(s):  
A. J. Matzke ◽  
A. Barta ◽  
E. Kuechler
Keyword(s):  
Relative Arrangement

Revised structure of a delta-aminolevulinic acid derivative

1993 ◽  
Vol 39 (9) ◽  
pp. 1867-1871 ◽  
Author(s):  
M Kajiwara ◽  
K Hara ◽  
K Takatori ◽  
K Matsumoto
Keyword(s):  
Aminolevulinic Acid ◽  
Nuclear Overhauser Effect ◽  
Correlation Spectroscopy ◽  
Molecular Formula ◽  
X Ray ◽  
Overhauser Effect ◽  
13C Nuclear Magnetic Resonance ◽  
Relative Arrangement ◽  
Effect Difference ◽  
Nuclear Overhauser

Abstract The structure of the fluorescent derivative formed in the method of Okayama et al. (Clin Chem 1990; 36:1494-7) for determining delta-aminolevulinic acid (ALA) concentrations was reinvestigated after esterification. The molecular ion peak at m/z 303.1473 corresponded to the molecular formula of C17H21NO4 (calcd 303.1470). The infrared spectrum showed the presence of carbonyl and carboxyl groups. This compound contained two acetyl groups, two methyl groups, and one methoxycarbonylethyl group, as revealed by 1H and 13C nuclear magnetic resonance and 13C-1H shift-correlated spectroscopy. Experiments with correlation spectroscopy via long-range coupling indicated that the main skeleton is 3H-pyrrolizine. The relative arrangement of functional groups was determined by means of nuclear Overhauser effect difference experiments. We were led to the conclusion that the methyl ester of the derivative is 2,6-diacetyl-1,5-dimethyl-7-(2-methoxycarbonylethyl)-3H-pyrrolizine. This structure was unequivocally confirmed by x-ray analysis; therefore, the structure of the derivative itself is 2,6-diacetyl-1,5-dimethyl-7-(2-carboxyethyl)-3H-pyrrolizine.

SPH as an Inverse Numerical Tool for the Prediction of Diffusive Properties in Porous Media

2007 ◽  
Vol 553 ◽  
pp. 171-189 ◽  
Author(s):  
Antonio C.M. Sousa ◽  
Fangming Jiang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Porous Media ◽  
Fluid Flow ◽  
Effective Thermal Conductivity ◽  
Pore Scale ◽  
Relative Arrangement ◽  
Inclusion Shape ◽  
Micro Structures ◽  
Bulk Thermal Conductivity

Heat and mass transfer and fluid flow in porous media are usually characterized by, or associated with, the effective thermal conductivity, the effective mass diffusivity and the permeability, respectively. All these macroscopic quantities are conceptually established on a phenomenological “equivalence” basis. They may contain the influence of porous micro-structures upon the corresponding diffusive process; however, the detailed nature inside the porous medium is lumped and neglected. Pore scale numerical modelling has the potential of providing adequate meso-/micro- scale insight into the transport process in porous medium, as well as obtaining macroscopic properties, which can encompass the complex pore-structure details. Modelling heat/mass transfer and fluid flow in complicated porous micro-structures presents a major challenge to numerical methods due to their multiscale and multiphysics nature. A relatively-novel numerical technique - the meshless Lagrangian-based Smoothed Particle Hydrodynamics (SPH) method is thought to be capable of making a significant contribution to this research field. This work deals primarily with the SPH modelling of heat conduction and fluid flow in 2-D isotropic porous media. The porous matrix is formed by randomly including a different component into a base component. Various pore-structures are realized by changing the inclusion shape/size, or the relative arrangement condition between inclusions. Pore-scale heat transfer and fluid flow streams are visualized, and both heat transfer and fluid flow always follow, as expected, the paths of least resistance through the porous structures. In what concerns the effective thermal conductivity, for the porous media with the base component of larger bulk thermal conductivity, the “flexible” EMT model, which can accommodate, to some extent, the influence from the porous micro-structures on the effective thermal conductivity by adjusting the so-called flexible factor ff, gives effective thermal conductivities agreeable to the SPH predictions across the whole composition range if ff is taken to be ~ 4.5; the effective thermal conductivity shows a weak dependence on the inclusion shape/size and the relative arrangement condition between inclusions; however, for porous media with dispersed inclusions, which component has larger bulk thermal conductivity presents a strong effect upon the effective thermal conductivity. The SPH fluid flow simulation results confirm the macroscopic Darcy’s law to be valid only in the creeping flow regime; the dimensionless permeability (normalized by the squared characteristic dimension of the inclusions) is found to have an exponential dependence on the porosity within the intermediate porosity range, and the derived dimensionless permeability /""porosity relation is found to have only a minor dependence on either the relative arrangement condition between inclusions or the inclusion shape/area.

scholarly journals Postural Analysis of Male Football Athletes from Different Age Levels of Training

2021 ◽  
Vol 3 (4) ◽  
pp. 100-105
Author(s):  
Joana Filipa D.S. Lourenço ◽  
José Luís M. A. De Sousa ◽  
Denise P. Soares ◽  
Sónia C. Gonçalves-Lopes
Keyword(s):  
Injury Rate ◽  
Football Players ◽  
Body Parts ◽  
Average Deviation ◽  
Horizontal Alignment ◽  
Relative Arrangement ◽  
Spss Software ◽  
Definition Of ◽  
The Right ◽  
Postural Analysis

Introduction: The definition of body posture involves a relative arrangement of body parts. Football is the most popular sport in the world with an injury rate of 4.47 injuries per 1000 hours of play/training per athlete. Photogrammetry is a valid and reproductive method for evaluating postural differences with quantitative and accurate results. The aim of this study is to present a postural analysis of children and young football players, using photogrammetry. Method: The sample consisted of 263 athletes (ages between 4 and 18 years) where, through the photographic register and use of SAPO® software the main postural deviations of the children were calculated and subsequently analyzed descriptively in the IBM SPSS software. Results: The results obtained show deviations in point A1 - alignment of the acromion (21.4% to 50% of athletes on the right (R) and 16.7% to 40.5% of athletes on the left (L); A2 - alignment of the anterosuperior iliac spine (42.9% of athletes to (R) and 14.3% to 64.9% to the left (L); A3 alignment of tibia tuberosities (27.9% to 55% of athletes (R), 27% to 48.5% of athletes (L); A4 and A5 – angle Q (R and L) (50% to 91% of athletes with tendency to knee varus); A6 – horizontal alignment of the pelvis (tendency to hyperlordosis of 28% for juveniles with an average deviation of -15.4° ± 7.7). Conclusion: The postural analysis of the athletes allows a better knowledge about the most frequent deviations that, over time, can become painful, being important an intervention and specific planning at this level, trying to prevent future injuries.

scholarly journals Method for Calculating the Shape of Rolls for Helical Rolling

2022 ◽  
Author(s):  
S. Gorbatyuk
Keyword(s):  
Calculation Method ◽  
Deformation Zone ◽  
Helical Rolling ◽  
Rolling Mills ◽  
Cad Systems ◽  
Rolling Axis ◽  
Working Surface ◽  
Relative Arrangement ◽  
Calculation Results ◽  
Intuitive Interface

Abstract. The paper is devoted to solving the problem of determining the shape of the rolls of helical rolling mills, depending on the specified profile of the deformation zone. A universal calculation method has been proposed, thanks to which it is possible to determine the shape of the working surface of a roll for all types of helical rolling mills (with mushroom-shaped, cup-shaped, barrel-shaped and disc rolls), any relative arrangement of the rolling axis and rolls axes, and various locations of the deformation zone on the rolling axis. The proposed method is implemented as a standalone exe-application with a simple intuitive interface. The application allows you to output the calculation results into txt-files, which can then be imported into CAD systems to create 3D roll models.

The Volvo-Turbo Experimental Gas Turbine

1962 ◽  
Author(s):  
S. O. Kronogard
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Short Description ◽  
Reduction Gear ◽  
Working Cycle ◽  
Power Turbine ◽  
Relative Arrangement ◽  
Selection Of

This paper gives a brief description of the Volvo experimental turbine, its working cycle, its basic components and their relative arrangement as well as some of the basic thinking behind the selection of the same. The paper also gives a short description of the new concept of a dual-geared power turbine, the combined reduction gear and high-speed hydrodynamic retarder, as well as some other new features incorporated.

scholarly journals VI. Tabulated data for the examination of the 230 space-groups by homogeneous X-rays

1924 ◽  
Vol 224 (616-625) ◽  
pp. 221-257 ◽  
Keyword(s):  
Crystal Structures ◽  
Chemical Society ◽  
Unit Cell ◽  
X Rays ◽  
Screw Axis ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
Relative Arrangement

The object of the present paper is to express the conclusions of mathematical crystallography in a form which shall be immediately useful to workers using homogeneous X-rays for the analysis of crystal structures. The results are directly applicable to such methods as the Bragg ionisation method, the powder method, the rotating crystal method, etc., and summarise in as compact a form as possible what inferences may be made from the experimental observations, whichever one of the 230 possible space-groups may happen to be under examination. It is only in certain cases that the spacings of crystal planes as determined by the aid of homogeneous X-rays agree with the values of those spacings which would be expected from ordinary crystallographic calculations. In the majority of cases the relative arrangement of the molecules in the unit cell leads to apparent anomalies in the experimental results, the observed spacings of certain planes or sets of planes being sub-multiples of the calculated spacings. The simplest case (fig. 8) of such an apparent anomaly is found in the space-group C 2 2 of the monoclinic system, where the presence of a two-fold screw-axis, because it interleaves halfway the (010) planes by molecules which are exactly like those lying in the (010) planes, except that they have been rotated through 180°, leads to an observed periodicity which is half the periodicity to be inferred from the dimensions of the unit cell, that is, leads to an observed spacing for (010) which is half the calculated. All screw-axes produce similar results, and, in general, a p -fold screw-axis leads to an observed spacing for the plane perpendicular to it which is 1/ p th that to be inferred from the dimensions of the cell. Besides those produced by the screw-axes, other abnormalities arise out of the presence of glide-planes. The simplest case of this is shown by the space-group C s 2 (fig. 4) of the monoclinic system, in which the second molecule is obtained from the first by a reflection in a plane parallel to (010) and half a primitive translation parallel to that plane. If we look along a direction perpendicular to this glide-plane, the projections of the two molecules on the (010) plane are indistinguishable except in position, which is equivalent to saying that, for the purposes of X-ray interference, certain planes perpendicular to this plane of projection are interleaved by an identical molecular distribution. Furthermore, since the translation associated with the glide-plane must always be half a primitive translation parallel to the glide-plane, we know that the interleaving is always a submultiple of the full spacing and the periodicity is again reduced in a corresponding manner. The use of this method for discriminating between the various space-groups of the monoclinic system was described by Sir Wm. Bragg in a lecture to the Chemical Society. In the present paper the method has been extended to the whole of the 230 space-groups possible to crystalline structures. In general, it may be said that if a crystal possesses a certain glide-plane, a certain set of planes lying in the zone whose axis is perpendicular to that glide-plane will have their periodicity reduced by one-half.

scholarly journals On the effect of a longitudinal magnetic field on the internal viscosity of wires of nickel and iron, as shown by change of the rate of subsidence of torsional oscillations

1902 ◽  
Vol 70 (459-466) ◽  
pp. 294-302 ◽  
Keyword(s):  
Magnetic Field ◽  
Internal Friction ◽  
Physical Properties ◽  
Longitudinal Magnetic Field ◽  
Torsional Oscillations ◽  
Relative Arrangement ◽  
Internal Viscosity ◽  
Different Parts

We can obtain information as to the nature of the magnetisation of magnetisable bodies only by testing the various hypotheses with reference to effects which it seems likely should, under these hypotheses, be produced on the physical properties of the substance. Thus, for example, the internal friction of the different parts of a solid must depend upon the size and mode of arrangement of these parts, and any alteration in their dimensions or relative arrangement ought in general to produce some change in the amount of the internal friction.

scholarly journals The AWSEM-Amylometer: predicting amyloid propensity and fibril topology using an optimized folding landscape model

2017 ◽  
Author(s):  
Mingchen Chen ◽  
Nicholas P Schafer ◽  
Weihua Zheng ◽  
Peter G Wolynes
Keyword(s):  
Amyloid Fibrils ◽  
Protein Sequences ◽  
Landscape Model ◽  
Fiber Structure ◽  
Multiple Datasets ◽  
Folding Simulation ◽  
Relative Arrangement ◽  
Free Energy Landscapes ◽  
Amyloidogenic Peptides ◽  
Functional Amyloids

AbstractAmyloids are fibrillar protein aggregates with simple repeated structural motifs in their cores, usually β-strands but sometimes α-helices. Identifying the amyloid-prone regions within protein sequences is important both for understanding the mechanisms of amyloid-associated diseases and for understanding functional amyloids. Based on the crystal structures of seven cross-β amyloidogenic peptides with different topologies and one recently solved cross-α fiber structure, we have developed a computational approach for identifying amyloidogenic segments in protein sequences using the Associative memory, Water mediated, Structure and Energy Model. The AWSEM-Amylometer performs favorably in comparison with other predictors in predicting aggregation-prone sequences in multiple datasets. The method also predicts the specific topologies (the relative arrangement of β-strands in the core) of the amyloid fibrils well. An important advantage of the AWSEM-Amylometer over other existing methods is its direct connection with an efficient, optimized protein folding simulation model, AWSEM. This connection allows one to combine efficient and accurate search of protein sequences for amyloidogenic segments with the detailed study of the thermodynamic and kinetic roles that these segments play in folding and aggregation in the context of the entire protein sequence. We present new simulation results that highlight the free energy landscapes of peptides that can take on multiple fibril topologies. We also demonstrate how the Amylometer methodology can be straightforwardly extended to the study of functional amyloids that have the recently discovered cross-α fibril architecture.

scholarly journals Characterization of the oriI andoriII Origins of Replication in Phage-Plasmid P4

1999 ◽  
Vol 73 (9) ◽  
pp. 7308-7316 ◽  
Author(s):  
Arianna Tocchetti ◽  
Gloria Galimberti ◽  
Gianni Dehò ◽  
Daniela Ghisotti
Keyword(s):  
Complementation Test ◽  
Plasmid Replication ◽  
Deletion Mapping ◽  
Type I ◽  
Rich Region ◽  
Origins Of Replication ◽  
Essential Components ◽  
Relative Arrangement

ABSTRACT In the Escherichia coli phage-plasmid P4, two partially overlapping replicons with bipartite ori sites coexist. The essential components of the oriI replicon are the α andcnr genes and the ori1 and crrsites; the oriII replicon is composed of the α gene, with the internal ori2 site, and the crr region. The P4 α protein has primase and helicase activities and specifically binds type I iterons, present in ori1 and crr. Using a complementation test for plasmid replication, we demonstrated that the two replicons depend on both the primase and helicase activities of the α protein. Moreover, neither replicon requires the host DnaA, DnaG, and Rep functions. The bipartite origins of the two replicons share the crr site and differ forori1 and ori2, respectively. By deletion mapping, we defined the minimal ori1 and ori2regions sufficient for replication. The ori1 site was limited to a 123-bp region, which contains six type I iterons spaced regularly close to the helical periodicity, and a 35-bp AT-rich region. Deletion of one or more type I iterons inactivated oriI. Moreover, insertion of 6 or 10 bp within the ori1 region also abolished replication ability, suggesting that the relative arrangement of the iterons is relevant. The ori2 site was limited to a 36-bp P4 region that does not contain type I iterons. In vitro, the α protein did not bind ori2. Thus, the α protein appears to act differently at the two origins of replication.

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