bluuebunny/crossref_metadata_2025 huggingface dataset:
Opportunities for microbiome research to enhance farmed freshwater fish quality and production
Authors: Parata Lara , Sammut Jesmond , Egan Suhelen
Published: April 2021

Freshwater fish farming is the largest sub‐sector of the global aquaculture industry, with its continued success dependent on the industry’s ability to be productive and sustainable. In recent years, microorganisms have been increasingly recognised for their role in the health and overall performance of aquatic organisms, providing the aquaculture industry with a promising avenue for further success. Here, we review the literature on freshwater fish microbiology to evaluate the potential for microbial research to enhance freshwater aquaculture. A systematic review revealed that the existing freshwater fish microbiology literature incorporates <1% of freshwater fish species, with most studies focussed on Cyprinidae, Salmonidae and to a lesser extent Cichlidae. Using social network analyses, this review identified 25 key research areas commonly addressed in the existing literature highlighting the narrow focus of existing studies. Microbial community structure was the most frequently researched area, followed by environment and diet. These studies often evaluated microbiota changes associated with diadromous migrations, new technologies and advancements in feed formulations. However, research areas, such as the role of microorganisms in fish fecundity, omega‐3 content, sustainability and palatability, were underrepresented in the literature despite their influence on aquaculture success. These underrepresented research areas are examples of where additional investments in microbial research are needed to ensure the continued expansion and success of freshwater aquaculture.
A systematic review of oral health educational media innovation for visually impaired children: Which one brings the best impact of change?
Authors: Maulanti Titis , Nurmala Ira
Published: April 2021

Aim

Various innovations of oral health education media were used to bring an impact on oral health behavior and status among visually impaired children. This paper was aimed to systematically investigate which innovation brings the best impact of change.

Methods

A systematic searching strategy in Scopus, PubMed, ProQuest, ScienceDirect, EBSCO, SAGE, and Cochrane Library database was applied in this study, then followed Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guideline. Studies from the last 10 years that investigate the innovation of oral health education media for visually impaired children and its impact on change were included.

Results

Of 653 studies identified, 10 were included in the data synthesis. Audio, Braille, audio‐tactile performance, verbal, tactile, or combinations were found to be utilized as the alternative media innovation of oral health education for visually impaired children. The combination of two or more media brings the best impacts of oral health behavior and oral health status among them.

Conclusions

The combination of oral health education media may involve various senses of learning. Due to its impact on the improvement of oral health behavior and status among visually impaired children, this innovation should be chosen.
Complications associated with continuous renal replacement therapy
Authors: Kovvuru Karthik , Velez Juan C. Q.
Published: April 2021

With the evolution of standardized replacement fluids, newer machines, and high flux membranes, continuous renal replacement therapy (CRRT) has made remarkable progress in the field of extracorporeal therapies. CRRT is the preferred dialytic modality for patients in intensive care unit setting (ICU). Standardized protocols are implemented by many institutions to avoid errors and ensure patient safety. However, complications related to CRRT are not uncommon. Understanding CRRT operations is essential to analyze the complications and further assist in developing measures to mitigate the risk. Overview of CRRT complications and potential preventive strategies are discussed in the current review.
Rethinking the “buffering” theory of neighborhood racial transition
Authors: Wright Richard , Ellis Mark
Published: April 2021

In metropolitan areas with significant numbers of Latinx and Black people, Santiago (1991) hypothesized that Latinx groups may “buffer” white neighborhoods from Black ones. Farley and Frey (1994, https://doi.org/10.2307/2096131) subsequently suggested that Latinx and Asian groups provide a social or spatial “buffer” that enables White and Black neighborhood coresidence. In predominantly White spaces, increases in the neighborhood shares of Latinx and Asian populations moderates White resistance to the presence of Blacks, and this helps explain growing neighborhood racial diversity in the United States. This essay suggests expanding the thesis in several ways. We first consider reversing the theory wherein Latinx and Asian groups provide a “buffer” enabling White and Black coresidence because Blacks are cushioned from the actions of Whites. This view requires us to include not only White tolerance but also White intolerance in the buffering logic. Second, we point out that racially mixed neighborhoods may also come about because people want to live in such diverse environments. Third, this leads to a consideration of processes of neighborhood racial mixing that include the roles of real estate markets actors in shaping neighborhood outcomes as well as the motivations of Latinx, Asian, and mixed‐race populations.
Gendering a New Marker of Adulthood: Home Ownership in Southwest China
Authors: Kane Danielle , Li Ke
Published: April 2021

Life course researchers have made important advances in understanding the Western transition to adulthood but have paid less attention to global variations and gender differences. This paper draws on Risman’s (2004, 2018) theory of gender as a social structure to examine the gendered meanings of establishing an independent household, a relatively new marker of adulthood in China that has evolved to focus on home ownership. Drawing on 100 interviews with men and women in two cities in southwest China, we find that men’s ability to buy a house was typically seen as an indicator of competence, potential, and independence. By contrast, for women a house was often described as something men or parents provided to spare them from having to attain this marker of adulthood on their own. This depiction of women as vulnerable and fragile was at odds with interviewees’ expectations for women’s actual financial contributions toward a house. This rhetoric made home ownership a “male marker” of adulthood that undermined women’s relationship to property, a key component of wealth in China.
Meat‐related cognitive dissonance: The social psychology of eating animals
Authors: Rothgerber Hank , Rosenfeld Daniel L.
Published: April 2021

As the practice of eating animals as meat faces increased scrutiny for its ethical, health, and environmental implications, a subfield devoted to its psychology has begun to flourish. Researchers have been especially interested in understanding how individuals morally care for animals and wish them no harm yet simultaneously eat them as food. Merging theories of cognitive dissonance, moral disengagement, and neutralization, the current review aims to provide a framework ofmeat‐related cognitive dissonance (MRCD)that explains this belief–behavior inconsistency. First, we evaluate the existing research on mechanisms that (a) prevent MRCD from occurring and (b) reduce MRCD once it has occurred. Second, we highlight promising avenues for further research on MRCD. The purpose of this review, ultimately, is to synthesize findings from this emerging area of research and to highlight its exciting future directions for the field of social psychology.
Positive psychological well‐being and cardiovascular disease: Exploring mechanistic and developmental pathways
Authors: Boehm Julia K.
Published: April 2021

Empirical research regarding the health benefits of positive psychological well‐being (e.g., positive emotions, life satisfaction, purpose in life, and optimism) has flourished in recent years, particularly with regard to cardiovascular disease. This paper reviews the state of evidence for well‐being's association with cardiovascular disease in both healthy individuals and those diagnosed with a disease. Prospective studies consistently indicate well‐being reduces cardiovascular events in healthy and, to a lesser extent, patient populations. Potential pathways that link well‐being with cardiovascular disease are discussed (including health behaviors, physiological processes, and stress buffering), although the existing evidence is mostly cross‐sectional which limits conclusions about directionality. Issues related to development across the lifespan are considered and childhood is identified as a crucial period for establishing healthy cardiovascular trajectories. Outstanding questions for future research are provided with recommendations to focus on well‐powered and prospective study designs with rigorous assessment of both well‐being and cardiovascular‐related outcomes.
Physician autonomy and patient rights: lessons from an enforced blood transfusion and the role of patient blood management
Authors: Bolcato Matteo , Shander Aryeh , Isbister James P. , Trentino Kevin M. , Russo Marianna , Rodriguez Daniele , Aprile Anna
Published: April 2021

This article provides an ethical and medico‐legal analysis of ruling no. 465 of 30 May 2018 issued by the Court of Termini Imerese (Palermo) and confirmed on appeal on 11 November 2020, which, in the absence of similar historical precedents in Europe, convicted a medical doctor of a crime of violent assault for having ordered the administration of a blood transfusion to a patient specifically declining blood transfusion on religious grounds. We analyse the Court’s decision regarding the identification of assault in performing the blood transfusion and its decision not to accept exculpatory urgent ‘necessity’ as a defence. In addition, we present an updated revision of the current standard of care in transfusion medicine as well as the ethical principles governing the patient's declining of transfusion. In doing so, we highlight that respect for the patient's self‐determination in declining transfusions and respect for the professional autonomy of the doctor protecting the safety and life of the patient could be equally satisfied by applying the current peer‐reviewed evidence.
Timing of and risk factors for deep surgical site infection requiring implant removal following canine tibial plateau leveling osteotomy
Authors: McDougall Renee A. , Spector Daniel I. , Hart Robert C. , Dycus David L. , Erb Hollis N.
Published: April 2021

Objective

To identify demographic risk factors for deep surgical site infection (SSI) requiring tibial plateau leveling osteotomy (TPLO) implant removal and time to implant removal.

Animals

Four hundred and thirty‐three dogs that underwent a TPLO (144 that developed a deep SSI and required implant removal, 289 that did not).

Study Design

Retrospective case–control study.

Methods

Records of dogs undergoing implant removal due to a deep SSI after TPLO between 2006 and 2018 at two referral centers were reviewed. These records were frequency‐matched by date to dogs undergoing TPLO that did not require implant removal. Multivariable analyses tested associations between demographics and implant removal as well as timing of implant removal.

Results

Deep SSI and implant removal occurred in 144 of 4813 (3.0%; 95% CI: 2.5, 3.5) dogs treated with TPLO. Implant removal was performed at a median of 279 days (range 49–2394 days) postoperatively. Male dogs (OR 1.8; 95% CI: 1.2, 2.7) and German Shepherd dogs (GSDs) (OR 7.4; 95% CI: 2.6, 20.5) were associated with plate removal. Earlier TPLO plate removal was associated with GSDs only (HR 2.4; 95% CI: 1.4, 4.1).

Conclusion

Implant removal due to SSI after TPLO was uncommon, although male dogs and GSDs seemed predisposed to this complication.

Significance

These demographic risk factors can be used to educate owners regarding perioperative management.
Fluid Flow Through Porous Metals
Authors: Green Leon , Duwez Pol
Published: April 2021

A method is outlined for correlating experimental data obtained in studies of the flow of gases and liquids through porous metals. The correlation is based upon the suggestion of Forcheimer that the pressure gradient attending the flow of a liquid through a porous medium can be expressed as a function of flow rate by a simple quadratic equation. An equation of this type defines two length parameters necessary for characterization of a porous structure and permits a general definition of the Reynolds number for a structure of arbitrary complexity.
A Superposition Analysis of the Turbulent Boundary Layer in an Adverse Pressure Gradient
Authors: Ross Donald , Robertson J. M.
Published: April 2021

As an interim solution to the problem of the turbulent boundary layer in an adverse pressure gradient, a super-position method of analysis has been developed. In this method, the velocity profile is considered to be the result of two effects: the wall shear stress and the pressure recovery. These are superimposed, yielding an expression for the velocity profiles which approximate measured distributions. The theory also leads to a more reasonable expression for the wall shear-stress coefficient.
Vibration of Rectangular and Skew Cantilever Plates
Authors: Barton M. V.
Published: April 2021

The Ritz method is used to determine approximate solutions for the frequencies and modes of vibration of uniform rectangular and skew cantilever plates. The functions used to represent the plate deflection correspond to those which define the normal modes of vibration of a uniform beam. Solutions are obtained for (a) uniform rectangular cantilever plates with cantilever span-to-breadth ratios of 1/2, 1, 2, and 5; (b) uniform skew cantilever plates with sides of equal length and skew angles of 15 deg, 30 deg, and 45 deg. Experimental values are presented and the correlation with analytical results discussed.
Axially Symmetrical Plates With Linearly Varying Thickness
Authors: Conway H. D.
Published: April 2021

The most practical problem in the bending of symmetrically loaded circular plates of variable thickness is probably that in which the thickness decreases linearly with the distance from the center of the plate. A general solution of the small-deflection problem of such plates is given here in closed form for the special case when Poisson’s ratio is 1/3. Numerical results are given for two particular examples, and these are compared with the results for corresponding plates of constant thickness.
The Limit Design of Space Frames
Authors: Heyman Jacques
Published: April 2021

The Greenberg-Prager maximum-minimum method for the limit design of plane frames is extended to space frames. This method furnishes upper and lower bounds for the load factor at collapse, and the bounds may be made as close as is considered necessary by a rational system of successive approximation.
Analysis of Deep Beams
Authors: Conway H. D. , Chow L. , Morgan G. W.
Published: April 2021

This paper presents a method of analyzing the stress distribution in a deep beam of finite length by superimposing two stress functions. The first stress function is chosen in the form of a trigonometric series which satisfies all but one of the boundary conditions—that of zero normal stress on the ends of the beam. The principle of least work is then used to obtain a second stress function giving the distribution of normal stress on the ends which is left by the first stress function. By superimposing the two solutions, all the boundary conditions are satisfied. Two particular cases of a given type of loading are solved in this way to investigate the stresses in a deep beam and their deviation from the ordinary beam theory. In addition, an approximate solution by the numerical method of finite difference is worked out for one of the two cases. Results from the two methods are compared and discussed. A method of obtaining an exact solution to the problem is given in an Appendix.
The Torsion of Elastic Spheres in Contact
Authors: Lubkin J. L.
Published: April 2021

A small torsional couple is applied about the axis of symmetry of a system of two elastic spheres (or solids of revolution) which have been pressed together by a force perpendicular to their common tangent plane. This problem may be reduced to a “problem of the plane,” and it has been found that in the absence of slip on the interface, the tangential traction is singular on the bounding circle. Hence the assumption of no slip is physically untenable. In the present solution allowance is made for slip by assuming that the tangential component of traction, for the area over which slip has progressed, is equal to the product of a constant friction coefficient and the normal or Hertzian distribution. A continuous expression for the traction is developed. A formula relating the radial depth of penetration of slip to the magnitude of the applied moment is given, and another relating this moment to the rotation of the contact surface of one of the bodies with respect to remote points in that body.
Analysis of Straight and Curved Beam-Columns
Authors: Tyler C. M. , Christiano J. G.
Published: April 2021

A method of analysis is developed for calculating the effects of deflection and axial force on the bending moments of structural members having both beam and column loadings. The member is divided into a number of segments and analyzed by a relaxation method directly in terms of the bending moments at each segment. This analysis is applicable to beam-columns of any shape and stiffness, and for any type of loading. A numerical example of an irregularly curved beam-column is included.
The Behavior of Graphite Under Alternating Stress
Authors: Green Leon
Published: April 2021

The fatigue properties of grade AUF extruded polycrystalline graphite were investigated at ambient and elevated temperatures. Specimens cut parallel to the axis of extrusion were stressed in reversed bending at room temperature and at 3550 F. The endurance limit of this graphite was found to increase from 2500 psi at room temperature to about 4400 psi at 3550 F. The increase in endurance limit is correlative with the increase in short-time tensile strength with temperature observed in earlier studies of graphite.
On Symmetrical Strain in Solids of Revolution in Spherical Co-Ordinates
Authors: Ling Chih-Bing , Yang Kuo-Liang
Published: April 2021

This paper presents the expressions for the displacements and stresses in the spherical co-ordinates, in terms of a stress function, for a solid of revolution in the state of symmetrical strain. Such expressions are useful in dealing with solids of revolution, which consist of spherical boundaries. The expressions are applied, as an illustration, to find the stresses in a large tension member having a spherical cavity. The required stress function is constructed in terms of Legendre polynomials. It may be interesting to compare this solution with the known solutions.
The Calculated Performance of Dynamically Loaded Sleeve Bearings—III
Authors: Burwell J. T.
Published: April 2021

In parts I and II of this series (6, 7), the performance of dynamically loaded sleeve bearings was calculated neglecting the transverse flow in the oil film, i.e., the bearing was assumed to be wide compared to its diameter, and then side-leakage factors based upon constant-load calculations were applied. In the present paper the performance is calculated for bearings assumed to be so narrow that film flow due to pressure in the direction of motion can be neglected. In this case the dependence upon bearing width appears explicitly and no side-leakage factors are required. Conclusions about the performance of the bearing under various simple types of loading are drawn. The two solutions for the limiting cases of very wide and very narrow bearings are compared and found to be qualitatively similar. From this it is concluded that bearings of arbitrary width should show the same qualitative behavior. Finally, the present solution is compared with exact calculations for certain narrow bearings, and the error involved in the present approximation is thereby determined.
The Theory of Plasticity Applied to a Problem of Machining
Authors: Lee E. H. , Shaffer B. W.
Published: April 2021

The recently developed methods of analyzing stress and strain distributions in the plane plastic flow of an ideally plastic material are applied to the problem of machining. It is shown that the idealized stress-strain relationship involves justifiable assumptions for this application. Analytical expressions are obtained for orthogonal machining which give the machining force, the chip thickness, and the chip deformation in terms of the tool geometry, the relevant coefficients of friction, and the appropriate yield stress of the work. With increasing friction at the tool face or decreasing rake angle the development of a built-up nose arises naturally as a consequence of the analysis. The theory includes this phenomenon. The results of this theory are compared with published experimental results, and with other theoretical analyses. Satisfactory agreement with experiment is obtained.
Critical Loads on Variable-Section Columns in the Elastic Range
Authors: Silver Gordon
Published: April 2021

This paper concerns the calculation of that loading (single or compound) on a variable-section column which causes elastic instability failure. The columns have the following end conditions: One end fixed with the opposite end free, both ends pinned, both ends fixed, one end fixed with the opposite end pinned.
Several Approximate Analyses of the Bending of a Rectangular Cantilever Plate by Uniform Normal Pressure
Authors: Nash W. A.
Published: April 2021

Three methods of approximating the deflections and moments occurring in a rectangular cantilever plate subjected to uniform normal pressure over its entire surface are presented in this paper. The first is the application of the well-known finite-difference procedure. The second and third are collocation methods, one based upon polynomial solutions of the Lagrange equation, the other employing “mixed” hyperbolic-trigonometric terms satisfying this equation. In the last two methods the boundary conditions are satisfied exactly along the clamped edge and at a finite number of points along the free edges of the plate. The results obtained for the particular case of a cantilever plate with uniform normal load indicate that the use of a relatively small number of points in the collocation method yields values of deflections and moments that are in substantial agreement with those given by the finite-difference procedure. It cannot be concluded from these results that the collocation method using the assumed functions will give satisfactory results with fewer points than the finite-difference method for cantilever plates with loading different from the one investigated.
The Calculation of Rectangular Bar Helical Springs
Authors: Wahl A. M.
Published: April 2021

Formulas and charts are given for calculating deflection and stress in helical compression or tension springs of rectangular cross section taking curvature effects into account. Such curvature effects are of importance particularly in small index springs in calculating stress (where fatigue is involved) and in calculating deflections for springs coiled flatwise.
On the Stresses in a Notched Strip
Authors: Ling Chih-Bing
Published: April 2021

In a previous paper by the author (1), a theoretical solution for a notched strip under longitudinal tension is given. The result demands the solution of an infinite system of linear equations. A considerable amount of labor is involved in solving such a system. It seems, however, that the labor can be diminished by adapting to the solution a process known as the promotion of rank. In this paper such a process is described and then applied to solve the problem of a notched strip under transverse bending. The solution of this problem seems also to be new. The numerical results obtained are compared graphically with the experimental results available.
Large Deflections of Circular Plates
Authors: Stippes M. , Hausrath A. H.
Published: April 2021

This paper contains a solution of von Kármán’s equations for a uniformly loaded, simply supported circular plate. The method used to obtain the solution is the perturbation procedure. Series expansions for the deflection and stresses in the plate are obtained. The legitimacy of these expansions is demonstrated in the Appendix. Critical values of stress and deflection are presented in graphical form. Furthermore, tables of coefficients for the afore-mentioned series are presented if anyone desires to extend the results which are presented here.
Bending of Elastoplastic Circular Plates With Large Deflection
Authors: Naghdi P. M.
Published: April 2021

A general theory for the elastoplastic bending of thin circular plates with polar symmetrical loading is developed, and a numerical integration method is given for the complete solution of problems within the scope of the general theory. In the development of the theory, stress-strain relations of the deformation type (theory of plastic deformation) are employed. As special examples, simply supported circular plates with a central concentrated loading are considered. Using a stress-strain curve for 24S-T aluminum which is determined experimentally, numerical solutions for bending moments, membrane forces, and deflections are obtained for two cases. In one case, the plate experiences large elastic deformation and in the second case, the plate undergoes large elastoplastic deformation. Several plate specimens, made of the same sheet of 24S-T aluminum for which the foregoing stress-strain curve was determined, are tested and a comparison is made between the theoretically determined and the experimentally obtained values of deflection.
A Study of Vanes Singing in Water
Authors: Gongwer C. A.
Published: April 2021

In the course of propulsion experiments in the ring-channel and rotating-boom facility at the Aerojet Engineering Corporation, it was discovered that certain struts which are used to support underwater bodies would “sing” at surprisingly low speeds, e.g., 5 to 7 knots. Tail surfaces also sang. The note emitted was a clear musical tone in most instances, and, as the speed was increased, the note would fade, disappear, and then reappear as a note of higher frequency. This singing caused considerable apprehension as it was feared that the strut would fail at high speeds due to build-up of the vibrations. Analysis for flutter stability and torsional divergence had been conducted, and it was known that the operation was well away from the ranges where flutter or torsional divergence might occur. However, the severity of the singing did not tend to become greater at high speeds, and there were usually quiet speed zones at high speeds as well as at low speeds.
Vibrations of Elastic Shells in a Fluid Medium and the Associated Radiation of Sound
Authors: Junger Miguel C.
Published: April 2021

This is a study of the vibrations of thin elastic shells freely suspended in a compressible fluid medium. The effect of the fluid reaction on the dynamic characteristics and, in particular, on the natural frequencies is investigated for cylindrical and spherical shells. The dynamic configuration of such shells undergoing forced vibration and the associated radiation of sound are determined. The problem is analyzed by means of the classical methods of the theory of mechanical vibrations; the Lagrange equations for the system are derived, the fluid reaction being introduced in the form of generalized forces. From the boundary condition that the normal shell deflection be equal to the normal fluid-particle displacement at the shell surface, and introducing the concept of acoustic impedance, it is shown that the fluid reaction is equivalent to an accession to the inertia of the shell and to a damping force. Numerical examples show that the effect of the fluid reaction on the dynamic characteristics of a shell may be of such magnitude as to render valueless calculations neglecting it.
Bending of a Uniformly Loaded Rectangular Plate With Two Adjacent Edges Clamped and the Others Either Simply Supported or Free
Authors: Huang M. K. , Conway H. D.
Published: April 2021

The distribution of deflection and bending moment in a uniformly loaded rectangular plate having two adjacent edges clamped and the others either simply supported or free, are obtained by a method of superposition. Numerical values are given for square plates and, in one case, the results are compared with those obtained by another method.
Deflection and Stresses in Beams Subjected to Bending and Creep
Authors: Pao Yoh-Han , Marin Joseph
Published: April 2021

This paper presents theories for the determination of deflections and stresses in beams subjected to bending and creep. The theories are based on a creep-stress-time relation in simple tension which gives an accurate fit of most test data. The theory takes into account the variation in stress distribution in bending with time. For this purpose a time-hardening theory is used to express the stress variation or stress relaxation of each fiber in bending. A comparison between actual creep deflections for Plexiglas specimens subjected to pure bending and values predicted by the proposed theory shows good agreement between experimental and theoretical results. The creep behavior for other materials in tension indicates that this method could be used for predicting bending creep deflections for these materials. The application of the theory to the determination of deflections in various kinds of beams is also explained.
A Simple Method of Determining Plastic Stresses and Strains in Rotating Disks With Nonuniform Metal Properties
Authors: Wu M. H. Lee
Published: April 2021

This paper presents a simple method of solving plastic deformation of a rotating disk having nonuniform metal properties. A stress-strain surface, which is formed by stress-strain curves obtained from the tensile specimens cut at different radii of the disk in the tangential direction, is introduced. The distributions of plastic stresses and strains can be obtained by a simple multiplication with the use of a short table given in the paper and a stress-strain curve along the radius of the disk determined from the stress-strain surface. The rotating-speed parameter is simplified to a simple algebraic function of maximum octahedral shear strain of the disk, and a parameter determined directly from the stress-strain curve along the radius of the disk. A chart calculated from such relations is given. The relation between rotating speed and maximum strain determined from the chart are compared with the experimental data of disk test; results agree well.
Stress Singularities Resulting From Various Boundary Conditions in Angular Corners of Plates in Extension
Authors: Williams M. L.
Published: April 2021

As an analog to the bending case published in an earlier paper, the stress singularities in plates subjected to extension in their plane are discussed. Three sets of boundary conditions on the radial edges are investigated: free-free, clamped-clamped, and clamped-free. Providing the vertex angle is less than 180 degrees, it is found that unbounded stresses occur at the vertex only in the case of the mixed boundary condition with the strength of the singularity being somewhat stronger than for the similar bending case. For vertex angles between 180 and 360 degrees, all the cases considered may have stress singularities.

In amplification of some work of Southwell, it is shown that there are certain analogies between the characteristic equations governing the stresses in extension and bending, respectively, if ν, Poisson’s ratio, is replaced by −ν. Finally, the free-free extensional plate behaves locally at the origin exactly the same as a clamped-clamped plate in bending, independent of Poisson’s ratio.

In conclusion, it is noted that the free-free case analysis may be applied to stress concentrations in V-shaped notches.
The Stresses in a Flat Curved Bar Due to Concentrated Radial Loads
Authors: Nelson C. W. , Ancker C. J. , Wu Ning-Gau
Published: April 2021

This paper presents a Fourier integral solution for the plane-stress problem of a curved bar bounded by two concentric circles and loaded by any combination of radial loads on the circular boundaries. It is an extension of an earlier investigation (1) which dealt with only the particular case of a curved bar in equilibrium under the action of two equal and opposite radial forces, one on each boundary. Numerical results are given for one of two basic cases from which the stresses for any combination of concentrated radial loads may be obtained by superposition. An example is included to show how superposition may be used to obtain the stresses for a loading condition which may occur frequently in practical machine-design problems. It is believed that the procedures developed in this paper will be useful in the solution of other elasticity problems by the Fourier integral method.
Resolving Pitching Airfoil Transonic Aerodynamics by Computational Fluid Dynamics Data Modeling1
Authors: Kaul Upender K.
Published: April 2021

A detailed numerical study of harmonically pitching airfoils of NACA00 series is presented here. Based on the analysis of the computational fluid dynamics (CFD) results, a hypothesis is made that a simple data model can capture the dynamics of the airfoils in pitch. The data model is based on the cl−α (lift coefficient–angle of attack) hysteresis loops that retain generic geometrical characteristics for a wide range of reduced frequency, k, encountered in flutter in transonic flows for all the NACA00 airfoils considered. The model was trained on a subset of the considered NACA00 airfoils and then tested on the remaining NACA00 set, for a subset of the reduced frequencies. The model predictions of the cl−α hysteresis loops for the test set are shown to be in excellent agreement with the CFD results for the range of k typical of transonic flutter. The data model offers a paradigm shift in the prediction of transonic flow dynamics of pitching airfoils and will guide the development of a new transfer function that will be incorporated in a new aeroelastic framework leading to an appropriate transonic flutter model for use in the development of future aircraft.
A Comparison of the Turbine Tower Damping Effects of a Series of Back Twisted Active Pitch-to-Stall Blades for a Spar and a Semi-Submersible FOWT
Authors: Ward Dawn , Collu Maurizio , Sumner Joy
Published: April 2021

Floating offshore wind turbines are subjected to higher tower fatigue loads than their fixed-to-seabed counterparts, which could lead to reductions in turbine life. The worst increases are generally seen in the tower axial fatigue, associated with the tower fore-aft bending moment. For a spar type platform, this has been shown to increase by up to 2.5 times and for a semi-submersible platform, by up to 1.8 times. Reducing these loads would be beneficial, as the alternative of strengthening the towers leads to increase in cost. Here, two offshore floating wind turbine systems, of the spar type, are analyzed and selected responses and tower fatigue are compared: one incorporates a variable-speed, variable-pitch-to-stall blade control system and a back twisted blade, and the other a conventional pitch-to-feather control. The results are then compared with those obtained in an earlier study, where the same turbine configurations were coupled to a semi-submersible platform. A weighted wind frequency analysis at three mean turbulent wind speeds of 8, 13, and 18 m/s highlights that the impact of the back twist angle magnitude and initiation point on tower axial fatigue life extension was the same for both platform types. Compared with their respective feather base models, an increase in the tower axial fatigue life of 18.8% was seen with a spar platform and 10.2% with a semi-submersible platform, when a back twist angle to the tip of −6 deg was imposed along with the variable-speed, variable-pitch-to-stall control.
WraptMor: Confirmation of an Approach to Estimate Ligament Fiber Length and Reactions With Knee-Specific Morphology
Authors: Zaylor William , Halloran Jason P.
Published: April 2021

Knee ligament length can be used to infer ligament recruitment during functional activities and subject-specific morphology affects the interplay between ligament recruitment and joint motion. This study presents an approach that estimated ligament fiber insertion-to-insertion lengths with wrapping around subject-specific osseous morphology (WraptMor). This represents an advancement over previous work that utilized surrogate geometry to approximate ligament interaction with bone surfaces. Additionally, the reactions each ligament imparted onto bones were calculated by assigning a force–length relationship (kinetic WraptMor model), which assumed that the insertion-to-insertion lengths were independent of the assigned properties. Confirmation of the approach included comparing WraptMor predicted insertion-to-insertion length and reactions with an equivalent displacement-controlled explicit finite element model. Both models evaluated 10 ligament bundles at 16 different joint positions, which were repeated for five different ligament prestrain values for a total of 80 simulations per bundle. The WraptMor and kinetic WraptMor models yielded length and reaction predictions that were similar to the equivalent finite element model. With a few exceptions, predicted ligament lengths and reactions agreed to within 0.1 mm and 2.0 N, respectively, across all tested joint positions and prestrain values. The primary source of discrepancy between the models appeared to be caused by artifacts in the finite element model. The result is a relatively efficient approach to estimate ligament lengths and reactions that include wrapping around knee-specific bone surfaces.
Kinematic Analysis and Optimal Design of a Novel Schönflies-Motion Parallel Manipulator With Rotational Pitch Motion for Assembly Operations
Authors: Yang Xiansheng , Zhao Zhilong , Xiong Hao , Li Qinchuan , Lou Yunjiang
Published: April 2021

This paper presents a novel Schönflies-motion Parallel Manipulator with RotationalPitch motion (SPM-RP) based on a single-platform fully parallel mechanism. An analysis of the position, workspace, velocity, and singularity of the SPM-RP is carried out in detail, and a dimensionless Jacobian is proposed to evaluate the manipulability of the SPM-RP. The analysis shows that the SPM-RP is with position-decoupled kinematics, a large singularity-free workspace, and excellent manipulability. The SPM-RP is actuated by four parallel prismatic actuators, enabling the manipulator to provide the identical kinematic performance at all generic cross sections perpendicular to the prismatic joint axes within its workspace. This paper thus proposes a reduced design optimization formulation, where the traditional optimization over the entire workspace is reduced to the optimization on a representative workspace cross section of the SPM-RP. According to this approach, the design optimization of the SPM-RP is carried out by maximizing its manipulability over the total orientation workspace, which is crucial for precision assembly. Based on the achieved optimal design, an SPM-RP prototype is developed. The mobility, orientation capability, total orientation workspace, and repeatability of the optimal design are tested and verified by the developed SPM-RP prototype. Experiments show that the SPM-RP can achieve a large total orientation workspace with excellent precision performance.
A Reformulation of Degree of Disequilibrium Analysis for Automatic Selection of Kinetic Constraints in the Rate-Controlled Constrained-Equilibrium Method
Authors: Hadi Fatemeh , Roy Shrabanti , Askari Omid , Beretta Gian Paolo
Published: April 2021

The rate-controlled constrained equilibrium (RCCE) is a model reduction scheme for chemical kinetics. It describes the evolution of a complex chemical system with acceptable accuracy with a number of rate controlling constraints on the associated constrained-equilibrium states of the system, much lower than the number of species in the underlying detailed kinetic model (DKM). Successful approximation of the constrained-equilibrium states requires accurate identification of the constraints. One promising procedure is the fully automatable Approximate Singular Value Decomposition of the Actual Degrees of Disequilibrium (ASVDADD) method that is capable of identifying the best constraints for a given range of thermodynamic conditions and a required level of approximation. ASVDADD is based on simple algebraic analysis of the results of the underlying DKM simulation and is focused on the behavior of the degrees of disequilibrium (DoD) of the individual chemical reactions. In this paper, we introduce an alternative ASVDADD algorithm. Unlike the original ASVDADD algorithm that require the direct computation of the DKM-derived DoDs and the identification of the set of linearly independent reactions, in the alternative algorithm, the components of the overall degree of disequilibrium vector can be computed directly by casting the DKM as an RCCE simulation considering a set of linearly independent constraints equaling the number of chemical species in size. The effectiveness and robustness of the derived constraints from the alternative procedure is examined in hydrogen/oxygen and methane/oxygen ignition delay simulations and the results are compared with those obtained from DKM.
Urolithin A improves muscle function by inducing mitophagy in muscular dystrophy
Authors: Luan Peiling , D’Amico Davide , Andreux Pénélope A. , Laurila Pirkka-Pekka , Wohlwend Martin , Li Hao , Imamura de Lima Tanes , Place Nicolas , Rinsch Chris , Zanou Nadège , Auwerx Johan
Published: April 2021

The mitophagy inducer urolithin A reverts muscular dystrophies.
Druggable cancer phosphatases
Authors: Vainonen Julia P. , Momeny Majid , Westermarck Jukka
Published: April 2021

Progress has been made in pharmacological targeting of tumor suppressor and oncogenic phosphatases for cancer therapy.
Metagenomic Characterization of Soil Microbial Communities in the Luquillo Experimental Forest (Puerto Rico) and Implications for Nitrogen Cycling
Authors: Karthikeyan Smruthi , Orellana Luis H. , Johnston Eric R. , Hatt Janet K. , Löffler Frank E. , Ayala-del-Río Héctor L. , González Grizelle , Konstantinidis Konstantinos T.
Published: April 2021

Tropical rainforests are the largest terrestrial sinks of atmospheric CO
2
and the largest natural source of N
2
O emissions, two greenhouse gases that are critical for the climate. The microbial communities of rainforest soils that directly or indirectly, through affecting plant growth, contribute to these fluxes remain poorly described by cultured-independent methods.
Draft Genome Sequences of Avian Chlamydia abortus Genotype G2 Strain 15-49d3, Isolated from Mallard, and Genotype 1V Strain 15-58d44, Isolated from Magpie in Poland
Authors: Zaręba-Marchewka Kinga , Szymańska-Czerwińska Monika , Niemczuk Krzysztof
Published: April 2021

Here, we report the draft genome sequences of avian
Chlamydia abortus
genotype G2 strain 15-49d3, isolated from mallard, and genotype 1V strain 15-58d44, isolated from magpie in Poland. The total genome assembly lengths are 1,140,139 bp and 1,158,207 bp, respectively.
Origin and age of the Shenshan tectonic mélange in the Jiangshan-Shaoxing-Pingxiang Fault and late Early Paleozoic juxtaposition of the Yangtze Block and the West Cathaysia terrane, South China
Authors: Wang Lijun , Zhang Kexin , Lin Shoufa , He Weihong , Yin Leiming
Published: April 2021

When and how the Yangtze Block (Yangtze) and the West Cathaysia terrane (West Cathaysia) in South China were amalgamated are critical to a better understanding of the Neoproterozoic to early Paleozoic tectonic evolution of South China and remain highly debatable. A key to this debate is the tectonic significance of the Jiangshan-Shaoxing-Pingxiang (JSP) Fault, the boundary between Yangtze and West Cathaysia. The Shenshan mélange along the JSP Fault has the typical block-in-matrix structure and is composed of numerous shear zone-bounded slivers/lenses of rocks of different types and ages that formed in different tectonic environments, including middle to late Tonian volcanic and volcanogenic sedimentary rocks (turbidite) of arc/back-arc affinity, a series of middle Tonian ultramafic to mafic plutonic rocks of oceanic island basalt affinity, a carbonaceous shale that was deposited in a deep marine environment, and a red mudstone. U-Pb zircon ages and acritarch assemblages (Leiosphaeridia-Brocholaminaria association) found in the turbidite confirm its Tonian age, and fossils from the carbonaceous shale (Asteridium-Comasphaeridium and Skiagia-Celtiberium-Leiofusa) constrains its age to the Early to Middle Cambrian. Field relationships and available age data leave no doubt that the ultramafic-mafic rocks are exotic blocks (rather than intrusions) in the younger metasedimentary rocks. We conclude that the Shenshan mélange is not an ophiolitic mélange, but rather a tectonic mélange that formed as a result of movement along the JSP Fault in the early Paleozoic. We suggest that Yangtze and West Cathaysia were two separate microcontinents, were accreted to two different parts of the northern margin of Gondwana in the early Early Paleozoic, and juxtaposed in the late Early Paleozoic through strike-slip movement along the JSP Fault. We further suggest that the ca. 820 Ma collision in the Jiangnan Orogen took place between Yangtze and a (micro)continent that is now partly preserved as the Huaiyu terrane and was not related to West Cathaysia. We compare our model for South China with the accretion of terranes in the North American Cordillera and propose a similar model for the relationship between the Avalon and Meguma terranes in the Canadian Appalachians, i.e., the two terranes were accreted to two different parts of the Laurentian margin and were later juxtaposed through margin-parallel strike slip faulting.
Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome in pregnancy
Authors: Balachandran Nair Deepa , Bloomfield Mariana , Parasuraman Rajeswari , Howe David T
Published: April 2021

The syndrome of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) is a rare mitochondrial disease with few documented cases in pregnancy. In this case report, we discuss the presentation and management of a 39-year-old grand multiparous lady with MELAS syndrome, which was diagnosed prior to her eighth pregnancy, discuss potential implications of the condition in pregnancy and summarise the current guidelines for the management of this rare condition.
Mid-oesophageal traction diverticulum in a patient with systemic lupus erythematosus
Authors: Chillarge Gauri , O'Neill Robert , Safranek Peter
Published: April 2021

In this report, a case of a large mid-oesophageal traction diverticulum in a 66-year-old woman with systemic lupus erythematosus has been presented. She was initially managed conservatively with active surveillance for 6 years. When her symptoms progressed, she had repeat endoscopy and CT scan which showed an increase in size of the diverticulum to 6 cm in diameter. Her dysphagia had progressively deteriorated and she was only managing a liquid diet. She, therefore, proceeded to resection of the diverticulum by right thoracotomy and stapled diverticulectomy. She made an excellent postoperative recovery and at last review, 5 months after the operation, she was back at work, had put on weight, and was tolerating a normal diet.