bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conserved and non‐conserved triggers of 24‐nucleotide reproductive phasiRNAs in eudicots
Authors: Pokhrel Suresh , Huang Kun , Meyers Blake C. 
Published: June 2021

SUMMARYSmall RNAs play important roles in plant growth and development by modulating expression of genes and transposons. In many flowering plant species, male reproductive organs, the anthers, produce abundant phased small interfering RNAs (phasiRNAs). Two classes of reproductive phasiRNAs are generally known, mostly from monocots: (i) pre‐meiotic 21‐nucleotide (nt) phasiRNAs triggered by miR2118 and (ii) meiotic 24‐nt phasiRNAs triggered by miR2275. Here, we describe conserved and non‐conserved triggers of 24‐nt phasiRNAs in several eudicots. We found that the abundant 24‐nt phasiRNAs in the basal eudicot columbine (Aquilegia coerulea) are produced by the canonical trigger miR2275, as well as by other non‐canonical triggers, miR482/2118 and miR14051. These triggering microRNAs (miRNAs) are localized in microspore mother cells and tapetal cells of meiotic and post‐meiotic stage anthers. Furthermore, we identified a lineage‐specific trigger (miR11308) of 24‐nt phasiRNAs and an expanded number of 24‐PHAS loci in wild strawberry (Fragaria vesca). We validated the presence of the miR2275‐derived 24‐nt phasiRNA pathway in rose (Rosa chinensis). Finally, we evaluated all eudicots that have been validated for the presence of 24‐nt phasiRNAs as possible model systems in which to study the biogenesis and function of 24‐nt phasiRNAs. We conclude that columbine (Aquilegia coerulea) would be a strong model because of its extensive number of 24‐PHAS loci and its diversity of trigger miRNAs.
Process and procedural adjustments to improve CD34+ collection efficiency of hematopoietic progenitor cell collections in sickle cell disease
Authors: Avecilla Scott T. , Boulad Farid , Yazdanbakhsh Karina , Sadelain Michel , Shi Patricia A. 
Published: June 2021

AbstractBackgroundAdequate CD34+ collection efficiency (CE) is critical to achieve target CD34+ cell doses in hematopoietic progenitor cell (HPC) collections. Autologous HPC collection in sickle cell disease (SCD) is associated with unstable collection interfaces and low CD34+ CEs. We hypothesized that variables specific to SCD, activation of blood cells and elevated viscosity, might contribute to these issues and made adjustments to the collection process and procedure to address our hypothesis.Study design and methodsIn two patients with SCD undergoing autologous HPC collection on our clinical trial (NCT02193191), we therefore implemented adjustments to the process and procedure in the following areas: proximity of RBC exchange to HPC collection, the type of anticoagulation, and the packing factor setting.ResultsThere was no collection interface instability. Our CD34+ CE1s were high at 70% and 51%, and granulocyte CE, platelet CE, and product granulocyte % were remarkably low. Product hematocrits were not as high as previously reported to be required to obtain adequate CEs. Interestingly, one HPC product showed a hemoglobin S (HbS) of 91% at the same time that the peripheral blood (PB) showed a HbS of 22%.DiscussionAdjustments to the HPC collection process and procedure were associated with adequate CD34+ CEs and low granulocyte and platelet contamination in HPC products from SCD patients. Given the discrepancy in the percentage of sickle RBCs in the product versus the PB, we hypothesize that CD34+ cells and RBCs may aggregate. Our interventions and hypothesis should be further investigated in larger studies.
In vivo operating lengths of the gastrocnemius muscle during gait in children who idiopathically toe‐walk
Authors: Harkness‐Armstrong Carla , Maganaris Constantinos , Walton Roger , Wright David M. , Bass Alfie , Baltzopoulos Vasilios , O'Brien Thomas D. 
Published: June 2021

New Findings
What is the central question of this study?
What are the in vivo operating lengths of the gastrocnemius muscle in children who idiopathically toe‐walk?
What is the main finding and its importance?
Children who idiopathically toe‐walk operate at more plantarflexed positions but at longer fascicle lengths than typically developing children during gait. However, these ranges utilised during gait correspond to where children who idiopathically toe‐walk are optimally strong. This should be considered when prescribing clinical treatments to restore typical gait.
AbstractChildren who idiopathically toe‐walk (ITW) habitually operate at greater plantarflexion angles than typically developing (TD) children, which might result in shorter, sub‐optimal gastrocnemius fascicle lengths. However, currently no experimental evidence exists to substantiate this notion. Five children who ITW and 14 TD children completed a gait analysis, whilst gastrocnemius fascicle behaviour was simultaneously quantified using ultrasound. The moment–angle (hip, knee and ankle) and moment–length (gastrocnemius) relationships were determined from isometric maximum voluntary contractions (MVC) on an isokinetic dynamometer combined with ultrasound. During gait, children who ITW operated at more plantarflexed angles (Δ = 20°; P = 0.013) and longer muscle fascicle lengths (Δ = 12 mm; P = 0.008) than TD children. During MVC, no differences in the peak moment of any joint were found. However, peak plantarflexor moment occurred at significantly more plantarflexed angles (−16 vs. 1°; P = 0.010) and at longer muscle fascicle lengths (44 vs. 37 mm; P = 0.001) in children who ITW than TD children. Observed alterations in the moment–angle and moment–length relationships of children who ITW coincided with the ranges used during gait. Therefore, the gastrocnemius muscle in children who ITW operates close to the peak of the force–length relationship, similarly to TD children. Thus, this study indicates that idiopathic toe‐walking is truly an ankle joint pathology, and children who ITW present with substantial alterations in the gastrocnemius muscle functional properties, which appear well adapted to the characteristic demands of equinus gait. These findings should be considered when prescribing clinical treatments to restore typical gait.
Functional reserve and sex differences during exercise to exhaustion revealed by post‐exercise ischaemia and repeated supramaximal exercise
Authors: Martin‐Rincon Marcos , Gelabert‐Rebato Miriam , Perez‐Valera Mario , Galvan‐Alvarez Victor , Morales‐Alamo David , Dorado Cecilia , Boushel Robert , Hallen Jostein , Calbet Jose A. L. 
Published: June 2021

Key points
Females have lower fatigability than males during single limb isometric and dynamic contractions, but whether sex‐differences exist during high‐intensity whole‐body exercise remains unknown.
This study shows that males and females respond similarly to repeated supramaximal whole‐body exercise, and that at task failure a large functional reserve remains in both sexes.
Using post‐exercise ischaemia with repeated exercise, we have shown that this functional reserve depends on the glycolytic component of substrate‐level phosphorylation and is almost identical in both sexes.
Metaboreflex activation during post‐exercise ischaemia and the O2 debt per kg of active lean mass are also similar in males and females after supramaximal exercise.
Females have a greater capacity to extract oxygen during repeated supramaximal exercise and reach lower , experiencing a larger drop in brain oxygenation than males, without apparent negative repercussion on performance.
Females had no faster recovery of performance after accounting for sex differences in lean mass.
AbstractThe purpose of this study was to ascertain what mechanisms explain sex differences at task failure and to determine whether males and females have a functional reserve at exhaustion. Exercise performance, cardiorespiratory variables, oxygen deficit, and brain and muscle oxygenation were determined in 18 males and 18 females (21–36 years old) in two sessions consisting of three bouts of constant‐power exercise at 120% of until exhaustion interspaced by 20 s recovery periods. In one of the two sessions, the circulation of both legs was occluded instantaneously (300 mmHg) during the recovery periods. Females had a higher muscle O2 extraction during fatiguing supramaximal exercise than males. Metaboreflex activation, and lean mass‐adjusted O2 deficit and debt were similar in males and females. Compared to males, females reached lower and brain oxygenation during supramaximal exercise, without apparent negative consequences on performance. After the occlusions, males and females were able to restart exercising at 120% of , revealing a similar functional reserve, which depends on glycolytic component of substrate‐level phosphorylation and its rate of utilization. After ischaemia, muscle O2 extraction was increased, and muscle was similarly reduced in males and females. The physiological response to repeated supramaximal exercise to exhaustion is remarkably similar in males and females when differences in lean mass are considered. Both sexes fatigue with a large functional reserve, which depends on the glycolytic energy supply, yet females have higher oxygen extraction capacity, but reduced and brain oxygenation.
Frequencies of a Flexible Circular Plate Attached to the Surface of a Light Elastic Half-Space
Authors: Bycroft G. N. 
Published: June 2021

Abstract
The frequencies of free vibration of a thin, flexible, circular plate stuck to the surface of a massless elastic half-space are solved by an application of the Rayleigh-Ritz principle. The approximate fundamental frequency is considered in detail when the plate is clamped, free, or hinged at its periphery. The method of obtaining the higher frequencies, such as those involving nodal diameters, is indicated.
Stress Distribution and Plastic Deformation in Rotating Cylinders of Strain-Hardening Material
Authors: Davis E. A. , Connelly F. M. 
Published: June 2021

Abstract
Equations for the stress distribution in plastic rotating cylinders are developed for both hollow and solid cylinders. It is assumed that the stress-strain relations may depend upon either the maximum shearing stress or the octahedral shearing stress and the corresponding shearing strain. A triaxiality factor proportional to the ratio of the hydrostatic tension to the octahedral shearing stress is introduced. This factor may be useful in evaluating the ductility of metals under combined stress.
A Definition of Stable Inelastic Material
Authors: Drucker D. C. 
Published: June 2021

Abstract
The definitions given previously for work-hardening and perfect plasticity are broadened to cover viscous effects. As before, the system considered is isothermal and includes both the body and the time-dependent set of forces acting upon it. An external agency is supposed to apply an additional set of forces to the already loaded body. It is now postulated that the work done by the external agency on the additional displacements it produces is positive. Some of the restrictions thus imposed on permissible stress-strain relations are explored. Especial attention is paid to simple laws of creep. Uniqueness of solution also is studied.
The Effect of Turbulence on Slider-Bearing Lubrication
Authors: Chou Ye Tsang , Saibel Edward 
Published: June 2021

Abstract
Based on Prandtl’s mixing-length mechanism, the pressure equation for turbulent flow in slider-bearing lubrication is derived. An analytical solution is given and compared with the one for laminar flow. It is found that the turbulent effect increases the pressure and, consequently, the load-carrying capacity. However, the power loss also increases.
A Theory of Oil Whip
Authors: Hori Yukio 
Published: June 2021

Abstract
Oil whip was investigated theoretically and experimentally. In the paper it is shown that the inherent instability of the rotor in previous theories can be avoided by assuming zero pressure in place of negative pressure in the oil film and that the “inertia effect” in occurrences of oil whip can be understood by distinguishing small vibrations and large vibrations of the rotor. It is also shown that oil whip of higher order and the effect of oil viscosity on amplitude of oil whip give possible causes of some peculiar phenomena.
Displacements and Stresses of a Laterally Loaded Semicircular Plate With Clamped Edges
Authors: Jurney W. H. 
Published: June 2021

Abstract
A solution is obtained for the case of the clamped semicircular plate of constant thickness, subjected to a uniformly distributed normal load. The method employed is superposition of solutions for a circular plate with fixed edges. The technique involved could be extended to study more general types of loading of the clamped semicircular plate. Results are based on the assumption that the Kirchhoff, or small deflection, theory applies.
Determination of the Creep Deflection of a Rivet in Double Shear
Authors: Marin Joseph 
Published: June 2021

Abstract
Structural components of modern aircraft are subjected to elevated temperatures by jet power plants and by skin friction resulting from supersonic speeds. Some of these high-temperature-aircraft structural components are riveted connections. Considerable experimental data are available on the creep of riveted connections used in aircraft [1]. However, a survey of the literature shows a lack of results on the theoretical prediction of creep in riveted connections from the usual creep and creep-rupture data for simple tension. The creep of a riveted joint is dependent on various factors including rivet diameter, rivet lengths, and plate thicknesses. This influence of size means that each particular riveted joint must be tested to obtain the necessary information. A basic approach to the problem is theoretically to predict the creep behavior of riveted joints from creep in simple tension. One of the important parts of the creep deformation of a riveted connection, Fig. 1(a), is the creep of the rivet. This paper deals with an approximate theoretical prediction of the creep deflection in a rivet based upon the creep constants of the material in simple tension.
Viscous Damping in Flexural Vibrations of Bars
Authors: Newman M. K. 
Published: June 2021

Abstract
Energy dissipation in flexural vibrations is considered by introducing into the Timoshenko beam equation viscous-damping terms proportional to the time rate of extensional strain. Two modes of wave transmission arise from the roots of a quartic equation. On the lower mode, a solution is indicated in terms of characteristic functions which represent the damped natural vibrations. For a specified range of values of damping, the amplitudes of natural vibrations are governed by characteristic damping factors which exhibit a maximum in the region of frequencies where wave velocities are dispersed. There can be no frequency cut-offs. In the higher mode of wave motion, the characteristic damping factors exhibit a monotone increase toward short wave-length limits analogous to those obtained in the Bernoulli-Euler-Sezawa equation.
Thermal Stresses in Moderately Thick Elastic Plates
Authors: Gatewood B. E. 
Published: June 2021

Abstract
The three-dimensional stresses in the plate are investigated without using the plane-stress or plane-strain assumptions, the thickness of the plate being limited so that the normal stress in the thickness direction can be taken as a polynomial in the thickness variable. The temperature is taken as a polynomial in the thickness variable but with relatively large, though restricted, gradients with respect to the co-ordinates of the plane of the plate. For the case of the temperature constant in thickness variable, the stresses in the plane of the plate are presented as the plane-stress solution plus correcting terms due to the plate thickness, where the correcting terms involve the product of the temperature gradient and the ratio of the plate thickness to the plate length in the direction of the temperature gradient. In many cases the corrections are small even for moderately thick plates.
Boundary-Layer Solution for a Flow in a Diverging Passage Having a Swirl Component
Authors: Sinbel M. A. 
Published: June 2021

Abstract
In this paper a solution is given to estimate the boundary-layer thickness owing to translational and rotational motion. The solution is an attempt to derive the boundary-layer equations when the main stream possesses both swirl and axial velocity. The development of the boundary layer in a conical duct is influenced by centrifugal action in addition to the pressure and viscous forces. The boundary-layer momentum integral equations are derived and presented herein for a set of spherical polar co-ordinates. The solution has been carried out for laminar flow. A turbulent form of the solution can be obtained by the introduction of the mixing-length theory. A numerical solution is carried out to make a comparison between the estimated and actual measured values.
Thermal Stresses Owing to a Hot Spot in a Rectangular Strip
Authors: Nelson C. W. 
Published: June 2021

Abstract
The thermal stresses for the plane-stress problem of a circular hot spot in an infinitely long straight strip of rectangular cross section are derived by a Fourier integral approach. The hot spot is located on the longitudinal center line of the strip, and its radius is such that the boundary of the hot spot is tangent to both edges of the strip. The temperature may be any function of the radius within the hot spot and is assumed to have a constant value (zero) throughout the rest of the strip. Numerical values are given for the stresses on the edges and both center lines of the strip for a particular case.
Axially Symmetric Extensional Vibrations of a Circular Disk With a Concentric Hole
Authors: Gustafsson O. G. , Kane T. R. 
Published: June 2021

Abstract
In a paper by T. R. Kane and R. D. Mindlin, a two-dimensional theory was developed for high-frequency extensional vibrations of elastic, isotropic plates. This theory is now used to study vibrations of a circular disk with a concentric hole.
Carrying Capacity of Elastic-Plastic Shells With Various End Conditions, Under Hydrostatic Compression
Authors: Paul Burton 
Published: June 2021

Abstract
This paper considers the influence of the beam-column effect on the carrying capacity of hydrostatically loaded elastic-plastic cylindrical shells. Specific problems considered include shells with clamped ends, simply supported ends, and a combination thereof. It is shown that in all cases considered there exist two characteristic modes of failure corresponding, respectively, to long and short shells where the terms “long” and “short” are unambiguously defined. Detailed results are presented graphically along with general conclusions useful for design purposes.
Incremental Stress-Strain Law Applied to Work-Hardening Plastic Materials
Authors: Hwang Chintsun 
Published: June 2021

Abstract
For problems involving work-hardening plastic materials, the incremental stress-strain law is considered to be a more rational approach than the conventional total stress-strain law. Up to the present the incremental stress-strain law was not subject to widespread use because it is mathematically inconvenient to handle. In this paper a method is developed in which the incremental law is applied to a work-hardening material in plane stress corresponding to the yield condition of von Mises. The method is illustrated by an analysis of the plastic bending of a simply supported work-hardening circular plate under uniformly distributed transverse load. The resulting difference-differential equations are solved by the NCR 304 digital computer.
On the Plastic Flow of Coulomb Solids Beyond Original Failure
Authors: Jenike A. W. , Shield R. T. 
Published: June 2021

Abstract
Principles developed for rigid-plastic solids exhibiting Coulomb’s properties are adapted to the analysis of flow beyond original failure. A variable yield function is proposed to account for the changes of cohesion during flow and equations are evolved for the stress field in two dimensions. It is shown that, while in the stress field an effective angle of friction larger than the actual angle of friction is mandatory for these materials, in the velocity field the materials can be assumed incompressible.
Piping Flexibility Analysis by Stiffness Matrix
Authors: Chen L. H. 
Published: June 2021

Abstract
A method of analysis is formalized for the solution of thermal-expansion stress problems in piping systems. The method is particularly suited for a complex system involving many anchors, closed loops within loops and/or interconnecting branch lines but without intermediate partial constraints. A summary of formulas and procedures necessary for practical application is included in the Appendix. Emphasis has been placed on the simplicity of the procedures which are well suited for automatic computation in digital computers.
The Fundamental Frequency of a Thin, Flat, Circular Plate Simply Supported Along a Circle of Arbitrary Radius
Authors: Bodine R. Y. 
Published: June 2021

Abstract
The fundamental transverse frequency is determined for a thin, flat, circular plate simply supported along a circle of arbitrary radius. It is shown that there are three support locations which coincide with “classical” plate solutions. The dimensionless frequency is plotted against the ratio of the support radius and outer-edge radius, showing the frequency variation with support location. The maximum frequency occurs when the support is located at the diameter of the first nodal circle of a free-edge plate.
Principal Component Analysis of Knee Joint Differences Between Bilateral and Unilateral Total Knee Replacement Patients During Level Walking
Authors: Yocum Derek , Reinbolt Jeffrey , Weinhandl Joshua T. , Standifird Tyler W. , Fitzhugh Eugene , Cates Harold , Zhang Songning 
Published: June 2021

Abstract
Many unilateral total knee replacement (TKR) patients will need a contralateral TKR. Differences in knee joint biomechanics between bilateral patients and unilateral patients are not well established. The purpose of this study was to examine knee joint differences in level walking between bilateral and unilateral patients, and asymptomatic controls, using principal component analysis. Knee joints of 1st replaced limbs of 15 bilateral patients (69.40 ± 5.04 years), 15 replaced limbs of unilateral patients (66.47 ± 6.15 years), and 15 asymptomatic controls (63.53 ± 9.50 years) were analyzed during level walking. Principal component analysis examined knee joint sagittal- and frontal-plane kinematics and moments, and vertical ground reaction force (GRF). A one-way analysis of variance analyzed differences between principal component scores of each group. TKR patients exhibited more flexed and abducted knees throughout stance, decreased sagittal knee range of motion (ROM), increased early-stance adduction ROM, decreased loading-response knee extension and push-off knee flexion moments, decreased loading-response and push-off peak knee abduction moment (KAbM), increased KAbM at midstance, increased midstance vertical GRF, and decreased loading-response and push-off vertical GRF. Additionally, bilateral patients exhibited reduced sagittal knee ROM, increased adduction ROM, decreased sagittal knee moments throughout stance, decreased KAbM throughout stance, an earlier loading-response peak vertical GRF, and a decreased push-off vertical GRF, compared to unilateral patients. TKR patients, especially bilateral patients had stiff knee motion in the sagittal-plane, increased frontal-plane joint laxity, and a quadriceps avoidance gait.