bluuebunny/crossref_metadata_2025 huggingface dataset:
Song but not plumage varies geographically among willow flycatcher Empidonax traillii subspecies
Authors: Mahoney Sean M. , Reudink Matthew W. , Pasch Bret , Theimer Tad C.
Published: November 2020

Plumage and song are important signals used by birds to attract mates and repel rivals. Divergence in sexual signals can lead to reproductive isolation among incipient species, but the relative importance of each modality may vary among taxa. Tyrannid flycatchers exhibit evolutionarily conservative plumage coloration but distinct song structure among subfamilies and species. Thus, tyrannids are an interesting group in which to study the relative role of plumage and song in contributing to population divergence. In this study, we assessed character divergence among four willow flycatcher Empidonax traillii subspecies by measuring spectral reflectance of plumage modeled in tetrahedral colorspace from museum specimens collected on putative breeding grounds. We also quantified differences in song structure based on publicly available and field‐recorded songs across the species range. Using unsupervised and unbiased clustering algorithms that assigned group membership independent of a priori taxonomic designations, we found that currently recognized subspecies did not consistently sort in accordance with subspecies designation based on plumage color. However, song analyses grouped birds into two clusters; one that included 89% of all putative E. t. extimus, and another that included 100% of specimens designated as E. t. adastus, E. t. brewsteri, E. t. traillii and a small percentage of E. t. extimus (11%). Our results are consistent with previous hypotheses of conservative plumage evolution in tyrannids and species differentiation based on song, and support the subspecific status of E. t. extimus.
Lessons learned on student engagement from the nature of pervasive socio‐digital interests and related network participation of adolescents
Authors: Kruskopf Milla , Hakkarainen Kai , Li Shupin , Lonka Kirsti
Published: November 2020

The rise of modern socio‐digital technologies has fundamentally changed the everyday environments in which young people communicate with each other and cultivate interests. To gain a more sophisticated understanding of this phenomenon, this study provides in‐depth, qualitative insights into adolescents' experiences of their socio‐digital developmental ecologies. The 15 interview participants were recruited based on a previously conducted questionnaire. The semi‐structured theme interview addressed the socio‐digital aspects of the participants' interest‐driven behaviours and related networks with the aid of participant‐generated egocentric maps. The data not only qualitatively enrich the picture on adolescents' friendship‐ and interest‐driven socio‐digital participation but also provide new perspectives on the phenomena through the added network‐layer of analysis. The youth seem to vary in their motivational profiles related to their participation and the potential relevant psychological background factors for this variation are considered. Educational implications of these results are discussed when it comes to effective student engagement and connected learning.
Improving representation of collective memory in socio‐hydrological models and new insights into flood risk management
Authors: Song Shuang , Wang Shuai , Fu Bojie , Dong Yuxiang , Liu Yanxu , Chen Haibin , Wang Yaping
Published: November 2020

Collective memory plays a controlling role in adaptation to potential flood risks, by learning from past disasters. However, with little quantitative empirical data, previous socio‐hydrological models have conceptualized the decaying process of flood memory in an oversimple approach. Here, based on survey data of 683 respondents on Ningxia Floodplain, we confirmed that flood memory decays overtime via two channels: oral communication (communicative memory) and physical recording of information (cultural memory). Using the Universal Decay Model (UDM) proposed by previous researchers provides better fitting of results to the decay of flooding memory (adjusted R2 coefficient are 0.97, 0.90, 0.95 when data of all, rural or urban respondents used, respectively) compared with the original exponential model (adjusted R2 coefficient are 0.91, 0.74, 0.59, corresponding). Then, significantly reduced losses for the same flood sequence predicted by integrating the UDM into a socio‐hydrological model by 16% and the differences between different clusters (urban and rural respondents) can even reach 22.81%. These differences suggest that previous socio‐hydrological models have been too simplistic in their conceptualizations of decaying processes associated with collective memory, which may have limited deeper insights into flood risk management.
Labour Constitutions and Occupational Communities: Social Norms and Legal Norms at Work
Authors: DUKES RUTH , STREECK WOLFGANG
Published: November 2020

This paper considers the interaction of legal norms and social norms in the regulation of work and working relations, observing that, with the contraction of collective bargaining, this is a matter that no longer attracts the attention that it deserves. Drawing upon two concepts from sociology – Max Weber's ‘labour constitution’ and Seymour Martin Lipset's ‘occupational community’ – it focuses on possibilities for the emergence, within groups of workers, of shared normative beliefs concerning ‘industrial justice’ (Selznick); for collective solidarity and agency; for the transformation of shared beliefs into legally binding norms; and for the enforcement of those norms. If labour law is currently in ‘crisis’, then a promising route out of the crisis, we argue, is for the law to recover its procedural focus, facilitating and encouraging these processes.
A retrospective cohort study reporting rituximab treatment for 33 patients with immunobullous disease
Authors: Watson Nicola , Carrozzo Marco , Hampton Philip
Published: November 2020

Background

Autoimmune bullous disorders, encompassing pemphigus and pemphigoid diseases, are associated with significant morbidity and mortality. This is in part due to high cumulative doses of corticosteroids in combination with immunosuppressant agents used in traditional treatment regimes. Rituximab is an antiCD20 monoclonal antibody which can induce complete remission, but it is currently unlicensed in the UK and approved only after other treatments have failed.

Methods

We report a retrospective cohort study of 33 patients with pemphigus and pemphigoid diseases treated with rituximab from a single tertiary centre from 2013 to 2019.

Results

“Complete remission off therapy” was achieved by 27.3% (n = 9), and a further 27.3% (n = 9) had complete remission on minimal therapy. Twenty‐one per cent (n = 7) had “partial remission on minimal therapy”; 9.1% (n = 3) patients were in the “consolidation phase,” and 12.1% (n = 4) had a “relapse/flare.” A steady reduction in prednisolone doses was observed post‐Rituximab infusion. Pre‐Rituximab the median dose of prednisolone was 20mg (range 10‐35, IQR 25), 15mg (range 9.5‐22.5, IQR 13) at 1 month, 9mg (range 5‐10, IQR 5) at 6 months, 4mg (range 0‐5mg, IQR 5) at 12 months and 0 (0‐4.35, IQR 4.25) at 18 months. Twelve per cent (n = 4) of patients had documented infusion reaction symptoms. Twelve per cent (n = 4) had later infective complications.

Conclusion

This real clinic data adds to the evidence that Rituximab is a safe and effective treatment for both pemphigus and pemphigoid autoimmune blistering conditions. Significantly, we were able to demonstrate a substantial reduction in corticosteroid dosage in our cohort of patients following rituximab treatment.
Respiratory viral infections in hospitalised paediatric patients in the tropics
Authors: Tan Keng Wein Jeanette , Yung Chee Fu , Maiwald Matthias , Saffari Seyed E , Thoon Koh Cheng , Chong Chia Yin
Published: November 2020

Aim

Respiratory viruses are a huge disease burden globally. An understanding of the seasonal trends and the ability to predict peak periods of respiratory virus disease incidence is useful for clinical care.

Methods

This is a retrospective analysis of paediatric hospitalizations of laboratory‐confirmed viral respiratory tract infections in KK Women's and Children's Hospital, Singapore, from 1 January 2011 to 31 December 2016. Standard direct immunofluorescence was used to detect respiratory syncytial virus (RSV), influenza A and B viruses, parainfluenza 1, 2 and 3 viruses, metapneumovirus and adenovirus.

Results

A total of 97 840 specimens were analysed with a positive detection rate of 23.8%. RSV made up the largest proportion (42% of the total positive results), predominating between May to September. Influenza A had two peaks, June to July and December to January. Type 3 was the most common parainfluenza virus and showed annually recurring peaks. In contrast, parainfluenza 1 and 2, metapneumovirus and adenovirus had a biennial pattern. The test of seasonality detected identifiable seasonality for RSV and parainfluenza 3 virus.

Conclusions

In conclusion, respiratory viruses have different and overlapping seasonality in tropical Singapore. Respiratory virus testing for patients admitted for acute respiratory infection is useful to target antiviral therapies and appropriate infection control practices.
Prokinetic actions of luminally acting 5‐HT4 receptor agonists
Authors: Konen John R. , Haag Melody M. , Guseva Daria , Hurd Molly , Linton Alisha A. , Lavoie Brigitte , Kerrigan Colleen B. , Joyce Emily , Bischoff Stephan C. , Swann Steve , Griffin Luana , Matsukawa Jun , Falk Matthew D. , Gibson Tony S. , Hennig Grant W. , Wykosky Jill , Mawe Gary M.
Published: November 2020

Background

5‐HT4 receptor (5‐HT4R) agonists exert prokinetic actions in the GI tract, but non‐selective actions and potential for stimulation of non‐target 5‐HT4Rs have limited their use. Since 5‐HT4Rs are expressed in the colonic epithelium and their stimulation accelerates colonic propulsion in vitro, we tested whether luminally acting 5‐HT4R agonists promote intestinal motility.

Methods

Non‐absorbed 5‐HT4R agonists, based on prucalopride and naronapride, were assessed for potency at the 5‐HT4R in vitro, and for tissue and serum distribution in vivo in mice. In vivo assessment of prokinetic potential included whole gut transit, colonic motility, fecal output, and fecal water content. Colonic motility was also studied ex vivo in mice treated in vivo. Immunofluorescence was used to evaluate receptor distribution in human intestinal mucosa.

Key Results

Pharmacological screening demonstrated selectivity and potency of test agonists for 5‐HT4R. Bioavailability studies showed negligible serum detection. Gavage of agonists caused faster whole gut transit and colonic motility, increased fecal output, and elevated fecal water content. Prokinetic actions were blocked by a 5‐HT4R antagonist and were not detected in 5‐HT4R knockout mice. Agonist administration promoted motility in models of constipation. Evaluation of motility patterns ex vivo revealed enhanced contractility in the middle and distal colon. Immunoreactivity for 5‐HT4R is present in the epithelial layer of the human small and large intestines.

Conclusions and Inferences

These findings demonstrated that stimulation of epithelial 5‐HT4Rs can potentiate propulsive motility and support the concept that mucosal 5‐HT4Rs could represent a safe and effective therapeutic target for the treatment of constipation.
Reflections on a registered report replicating a body of dyadic cross‐sectional research
Authors: Baker Zachary G. , Gentzis Ersie‐Anastasia , Watlington Emily M. , Castejon Sabrina , Petit Whitney E. , Britton Maggie , Haddad Sana , DiBello Angelo M. , Rodriguez Lindsey M. , Derrick Jaye L. , Knee C. Raymond
Published: November 2020

This article reflects on a new kind of registered report (RR) that replicated the work of an early career researcher. The research items targeted in this RR were peer‐reviewed, cross‐sectional, dyadic studies to which the first author of this RR had contributed. The findings being replicated are not noteworthy for their prestige or representativeness of the wider field. Instead, this method of replication may have several benefits and less desirable qualities for the researcher and research team whose work is being replicated, for science more broadly, and for relationship science specifically, reviewed herein. The authors hope that this reflection inspires researchers to improve upon their methodology by incorporating replication of their work early and often into their own research process.
Photosynthetic fluctuation accompanied by translocation of chloroplasts in Ulva conglobata (Ulvophyceae) grown under a low irradiance regime
Authors: Saco Jayvee Ablaña , Sekida Satoko , Mine Ichiro
Published: November 2020

Fluctuations in photosynthetic characteristics related to chloroplast translocation have been known in the foliose green algae Ulva lactuca var. latissima and var. rigida and U. mutabilis according to photoperiod. In Ulva, the single parietal chloroplast is found along the thallus surface wall and exhibits high photosynthetic activity during the light period; the chloroplast then moves towards the side walls and shows low photosynthetic activity during the dark period. In this study, we re‐investigated whether the photosynthetic ability is dependent on chloroplast location in a unialgal culture of U. conglobata grown and maintained under low irradiance regime by analyzing in vivo absorption spectra, oxygen evolution, and pulse amplitude modulation chlorophyll fluorescence. The light absorbance of the thallus was higher when chloroplast was along the thallus surface wall than when along the side walls and, therefore, the thallus absorbance at 680 nm was used as an index of chloroplast position. Some photosynthetic parameters such as maximum net photosynthetic rate per thallus area and effective quantum yield of photosystem II correlated with the thallus absorbance. The highest rate and absorption were reached 3 to 9 h after the beginning of light period (12 h), which gradually decreased at 10 to 15 h after the beginning of light or dark period. The lowest rate and absorption was observed after the beginning of the dark period. The chloroplast movement was inhibited for 12 h by colchicine, and photosynthetic parameters were found to be dependent on various chloroplast positions in the thallus. Interestingly, the chloroplast moved to the surface and the side walls of the cells under continuous dark and light conditions, respectively, at approximately 48 to 72 h. However, decreased maximum quantum yield was observed under both continuous dark and light conditions.
Pollution permits, green taxes, and the environmental poverty trap
Authors: Wei Sichao , Aadland David
Published: November 2020

We compare the steady states and transition dynamics under pollution permits and under green taxes in an overlapping generations model with endogenous longevity. Multiple steady states can emerge under pollution permits. One nontrivial steady state is an environmental poverty trap (EPT). This steady state is characterized by low capital and high pollution. An economy operating in the neighborhood will gravitate toward this steady state in the long run. The other nontrivial steady state featuring high capital and low pollution is desirable. A saddle path may lead to this desirable steady state. In contrast, the steady state under green taxes is unique and locally stable. We also design policies that prevent an economy from falling into the EPT under pollution permits. Our conclusion is that an economy can continue to consider pollution permits as an efficient environmental regulation but proceed with caution given the possibility of being drawn into an EPT.
Genomic full‐length sequence of the HLA‐A*26:89 allele was identified by full‐length group‐specific sequencing
Authors: An Run , Jiao Shuxian , Chi Xiaoyun , Pang Shutao
Published: November 2020

Genomic full‐length sequence of HLA‐A*26:89 was identified by group‐specific sequencing in a Chinese individual.
Invasive pulmonary aspergillosis associated with COVID‐19 in a kidney transplant recipient
Authors: Trujillo Hernando , Fernández‐Ruiz Mario , Gutiérrez Eduardo , Sevillano Ángel , Caravaca‐Fontán Fernando , Morales Enrique , López‐Medrano Francisco , Aguado José María , Praga Manuel , Andrés Amado
Published: November 2020

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) might increase the risk of invasive pulmonary aspergillosis (IPA). Although several case reports and small series have been reported in the general population, scarce information is available regarding coronavirus disease 2019 (COVID‐19)‐associated IPA in the setting of solid organ transplantation. We describe a case of a kidney transplant recipient with severe COVID‐19 that was subsequently diagnosed with probable IPA on the basis of the repeated isolation of Aspergillus fumigatus in sputum cultures, repeatedly increased serum (1 → 3)‐β‐d‐glucan levels, and enlarging cavitary nodules in the CT scan. The evolution was favorable after initiation of isavuconazole and nebulized liposomal amphotericin B combination therapy and the withdrawal of immunosuppression.
Direct Eulerian Formulation of Anisotropic Hyperelasticity
Authors: Volokh K. Y.
Published: November 2020

Many soft materials and biological tissues comprise isotropic matrix reinforced by fibers in the characteristic directions. Hyperelastic constitutive equations for such materials are usually formulated in terms of a Lagrangian strain tensor referred to the initial configuration and Lagrangian structure tensors defining characteristic directions of anisotropy. Such equations are “pushed forward” to the current configuration. Obtained in this way, Eulerian constitutive equations are often favorable from both theoretical and computational standpoints. In the present note, we show that the described two-step procedure is not necessary, and anisotropic hyperelasticity can be introduced directly in terms of an Eulerian strain tensor and Eulerian structure tensors referring to the current configuration. The newly developed constitutive equation is applied to the particular case of the transverse isotropy for the sake of illustration.
Time-Dependent System Kinematic Reliability Analysis for Robotic Manipulators
Authors: Zhao Qiangqiang , Guo Junkang , Zhao Dingtang , Yu Dewen , Hong Jun
Published: November 2020

Time-dependent system kinematic reliability of robotic manipulators, referring to the probability of the end-effector’s pose error falling into the specified safe boundary over the whole motion input, is of significant importance for its work performance. However, investigations regarding this issue are quite limited. Therefore, this work conducts time-dependent system kinematic reliability analysis defined with respect to the pose error for robotic manipulators based on the first-passage method. Central to the proposed method is to calculate the outcrossing rate. Given that the errors in robotic manipulators are very small, the closed-form solution to the covariance of the joint distribution of the pose error and its derivative is first derived by means of the Lie group theory. Then, by decomposing the outcrossing event of the pose error, calculating the outcrossing rate is transformed into a problem of determining the first-order moment of a truncated multivariate Gaussian. Then, based on the independent assumption that the outcrossing events occur independently, the analytical formula of the outcrossing rate is deduced for the stochastic kinematic process of robotic manipulators via taking advantage of the moment generating function of the multivariate Gaussian, accordingly leading to achievement of the time-dependent system kinematic reliability. Finally, a six-degrees-of-freedom (6-DOF) robotic manipulator is used to demonstrate the effectiveness of the proposed method by comparison with the Monte Carlo simulation and finite-difference-based outcrossing rate method.
A Comprehensive Study of Auxiliary Arrangements for Attaining Omnidirectionality in Additive Manufacturing Machine Tools
Authors: Singh Ambrish , Negi Seema , Kapil Sajan , Karunakaran K. P. , Das Manas
Published: November 2020

Anisotropy and omnidirectionality are the two most significant impediments to the growth of additive manufacturing (AM). While anisotropy is a property of the part, omnidirectionality is a characteristic of the machine tool. Omnidirectionality, implying invariance in AM processes with the goal of minimizing variations in material and geometric properties of the as-built parts, is often ignored during systems and process design. Disregard to directional sensitivity, which in some cases are inherent to the process (and/ or system), inadvertently changes the process parameter in-situ consequently, producing parts with non-uniform and often erratic properties. AM, attributing to its sheer number of processing variables, is especially susceptible to this subtle, yet significant system property. While some AM platforms, due to their nature of part production, are inherently omnidirectional, others require additional setup to ensure the same. Having an omnidirectional AM platform ensures that the parts are fabricated with process variables that are equally sensitive in all directions. In most AM systems, given a fixed set of process parameters, the spatial orientation of fusion (or joining) source vector, feedstock-delivery vector, and travel direction vector relative to each other governs omnidirectionality. Inconsistency or change in orientation of these three vectors results in non-uniform part properties and variations in geometric dimensions. Therefore, AM systems have to be omnidirectional to improve part performance and promote industrial acceptance. This paper, through a formal definition of omnidirectionality, analyses these three vectors individually along with their interplay with other process parameters and design variables.
Effect of a Combined Hot-Streak and Swirl Profile on Cooled 1.5-Stage Turbine Aerodynamics: An Experimental and Computational Study
Authors: Adams Maxwell G. , Beard Paul F. , Stokes Mark R. , Wallin Fredrik , Chana Kam S. , Povey Thomas
Published: November 2020

Recently developed lean-burn combustors offer reduced NOx emissions for gas turbines. The flow at exit of lean-burn combustors is dominated by hot streaks and residual swirl, which have been shown—individually—to impact turbine aerodynamic performance. Studies have shown that residual swirl at inlet to the high-pressure (HP) stage predominantly affects the vane aerodynamics, while hot streaks affect the rotor aerodynamics. Studies have also shown that these changes to the HP stage aerodynamics can affect the downstream intermediate-pressure (IP) vane aerodynamics. Yet, to date, there have been no published studies presenting experimental turbine test data with both swirl and hot streaks simultaneously present at inlet. This paper presents the first experimental and computational investigation into the effects of combined hot streaks and swirl on turbine aerodynamics. Experimental measurements were conducted in the Oxford Turbine Research Facility (OTRF), a short-duration rotating transonic facility, in which the nondimensional parameters relevant to turbine fluid mechanics and heat transfer are matched to engine conditions. The turbine under investigation is the recently commissioned LEMCOTEC turbine, which has been designed to represent modern aero-engine architectures and for robustness to lean-burn combustor-representative inlet flows. The turbine comprises an unshrouded HP stage with fully film-cooled vanes followed by low-turning IP vanes in an S-shaped duct. Two turbine inlet flows are considered. The first is uniform in total pressure, total temperature, and flow angle. The second features a nonuniform total temperature (hot streak) profile featuring strong radial and weak circumferential variation superimposed on a swirling velocity profile. This combined nonuniform profile is generated using a new combustor simulator that has recently been commissioned in the OTRF. Detailed area surveys of the flow were conducted at turbine inlet, HP rotor exit, and IP vane exit, and loading distributions were measured on the HP and IP vanes. Measurements and unsteady Reynolds-averaged Navier–Stokes (URANS) predictions suggest that the inlet temperature nonuniformity was relatively well preserved upon being convected through the turbine: the predicted root-mean-square variation in the IP vane exit total temperature field was approximately double that with uniform inlet conditions. Relatively poor comparisons between URANS and experiment highlight the challenge of accurately predicting the complex IP vane flow. In particular, small differences in exit whirl angle resulted in substantial differences in IP vane exit velocity and thus radial pressure gradient.
Wall Temperature Measurements in a Full-Scale Gas Turbine Combustor Test Rig With Fiber Coupled Phosphor Thermometry
Authors: Nau Patrick , Görs Simon , Arndt Christoph , Witzel Benjamin , Endres Torsten
Published: November 2020

Wall temperature measurements with fiber coupled online phosphor thermometry were, for the first time, successfully performed in a full-scale H-class Siemens gas turbine combustor. Online wall temperatures were obtained during high-pressure combustion tests up to 8 bar at the Siemens Clean Energy Center (CEC) test facility. Since optical access to the combustion chamber with fibers being able to provide high laser energies is extremely challenging, we developed a custom-built measurement system consisting of a water-cooled fiber optic probe and a mobile measurement container. A suitable combination of chemical binder and thermographic phosphor was identified for temperatures up to 1800 K on combustor walls coated with a thermal barrier coating (TBC). To our knowledge, these are the first measurements reported with fiber coupled online phosphor thermometry in a full-scale high-pressure gas turbine combustor. Details of the setup and the measurement procedures will be presented. The measured signals were influenced by strong background emissions probably from CO*2 chemiluminescence. Strategies for correcting background emissions and data evaluation procedures are discussed. The presented measurement technique enables the detailed study of combustor wall temperatures and using this information an optimization of the gas turbine cooling design.
Influences of Elastic Supports on Moving Load Identification of Euler–Bernoulli Beams Using Angular Velocity
Authors: Qiao Guandong , Rahmatalla Salam
Published: November 2020

This work investigates the effect of elastic support stiffness on the accuracy of moving load identification of Euler–Bernoulli beams. It uses the angular velocity response in solving the ill-posed inverse vibration problem and Tikhonov regularization in the load identification process of two moving loads. The effects from moving loads’ traveling direction, measurement location arrangements, number of participant measurements, and damping ratios are considered in the studies under noisy disturbance conditions. Results show that the stiffness of the translational rotational springs at the boundaries can impact the accuracy of identified moving loads considerably. Angular velocities presented much better results than accelerations under low stiffness conditions when vertical elastic supports were used. However, acceleration showed better performance when a very soft translational spring was used at one end and a much stiffer translational spring at the other end, as well as when rotational springs with large stiffness were used with simply supported beam conditions. The combination of angular velocities and accelerations provided a balanced solution for a wide range of elastic supports with different stiffnesses.
Impact and Bandgap Characteristics of Periodic Rods With Viscoelastic Inserts and Local Resonators
Authors: Alsaffar Y. , Aldraihem O. , Baz A.
Published: November 2020

A comprehensive theoretical and experimental study is presented of the bandgap behavior of periodic viscoelastic material (VEM) composites subjected to impact loading. The composites under consideration consist of an assembly of aluminum sections integrated with periodic inserts which are arranged in one-dimensional configurations. The investigated inserts are manufactured either from VEM only or VEM with local resonators (LR). A finite element model (FEM) is developed to predict the dynamics of this class of VEM composites by integrating the dynamics of the solid aluminum sections with those of VEM using the Golla-Hughes-Mctavish (GHM) mini-oscillator approach. The integrated model enables, for the first time, the accurate predictions of the bandgap characteristics of periodic viscoelastic composites unlike previous studies where the viscoelastic damping is modeled using the complex modulus approach with storage modulus and loss factor are assumed constants and independent of the frequency or the unrealistic and physically inaccurate Kelvin–Voigt viscous-damping models. The predictions of the developed FEM are validated against the predictions of the commercial finite element package ansys. Furthermore, the FEM predictions are checked experimentally using prototypes of the VEM composites with VEM and VEM/LR inserts. Comparisons are also established against the behavior of plain aluminum rods in an attempt to demonstrate the effectiveness of the proposed class of composites in mitigation of the structural response under impact loading. Close agreements are demonstrated between the theoretical predictions and the obtained experimental results.
Influence of the Carbon Content on the Surface Integrity of Deep Rolled Steels
Authors: Figueiredo dos Santos Filipe , da Costa Silva Sandro , Abrão Alexandre Mendes , Denkena Berend , Breidenstein Bernd , Meyer Kolja
Published: November 2020

Surface integrity refers to a set of characteristics of the surface and subsurface layers that have great influence on the functional performance of mechanical components under conditions of wear, corrosion, and fatigue and is determined by the manufacturing processes employed. Thus, surface treatments are used to generate a surface integrity suited to the desired function. Deep rolling is one of the surface treatments that involve cold working of the surface and subsurface layers. This work addresses the influence of selected deep rolling parameters (pressure, speed, feed, and number of passes) on the surface integrity (roughness, surface and subsurface microhardness, and microstructure) of AISI 1020, AISI 1065, and AISI 1080 carbon steels. Deep rolling significantly improved the surface finish; however, the excessive increase in pressure, associated with the reduction of the carbon content, and in feed, associated with the increase in the carbon content, increased the roughness. An increase in the number of passes, on the other hand, improved the surface finish in some cases. Under all conditions tested, deep rolling increased the microhardness of the subsurface layer and affected depth. Finally, the microstructure analysis showed that the increase in the carbon content promoted a reduction in grain deformation caused by deep rolling. Grain deformation was found to increase in AISI 1020 and AISI 1065 steels with increasing pressure and to reduce with the elevation of rolling speed and feed. The number of passes, on the other hand, affected only the subsurface layer of AISI 1020 steel.
A Mathematical Model for the Laminar Entrance Region of a Newtonian Fluid in a Cylindrical Pipe
Authors: Gross Richard J. , Garafolo Nicholas G. , McHugh Garrett R.
Published: November 2020

This paper develops equations for velocity, pressure drop, and wall shear stress in the entrance or development region of a cylindrical pipe. The model quantifies the velocity and wall shear stress contributions to the entrance region pressure drop and illustrates how data are used to determine the numerical values of parameters needed to complete the model. It assumes a Newtonian fluid, laminar flow, steady-state, and a constant mass density fluid. The fluid axial velocity profile at the entrance region inlet is modeled by an equation that is close to a flat axial velocity and drops off to zero as the radius approaches the wall. The fluid velocity at the entrance region exit is modeled as the axial, fully developed, laminar flow parabolic velocity profile. The inlet velocity profile is multiplied by a decaying function F(x) that is unity at the entrance region inlet and decreases to zero at the entrance region exit. The exit velocity profile is multiplied by a growing function G(x) that is zero at the entrance region inlet and increases to unity at the entrance region exit. The pressure drop through the entrance region is expressed in terms of the wall viscous friction and the change in axial momentum of the fluid. Two mathematical models for F(x) and G(x) are presented. One is more advantageous when pressure drop data and a few centerline velocity data points are available, and the second is more advantageous when only velocity data are available.
Computational Protocol for Spray Flow Simulations Including Primary Atomization
Authors: Lee T.-W. , Greenlee B. , Park J. E.
Published: November 2020

Primary atomization is the key element in spray flow simulations. We have, in our previous work, used and validated the integral form of the conservation equations, leading to the “quadratic formula” for determination of the drop size during spray atomization in various geometry. A computational protocol has been developed where this formulation is adapted to existing computational frameworks for continuous and dispersed (droplet) liquid phase, for simulations of pressure-atomized sprays with and without swirl. In principle, this protocol can be applied to any spray geometry, with appropriate modifications in the atomization criterion. The preatomization continuous liquid motion (e.g., liquid column or sheet) is computed using volume-of-fluid (VOF) or similar methods, then the velocity data from this computation is input to the quadratic formula for determination of the local drop size. This initial drop size, along with the local liquid velocities from VOF, is then used in a Lagrangian tracking algorithm for the postatomization dispersed droplet calculations. This protocol can be implemented on coarse-grid, time-averaged simulations of spray flows, and produces convincing results when compared with experimental data for pressure-atomized sprays with and without swirl. This approach is general, and can be adapted in any spray geometries for complete and efficient computations of spray flows.
Motion Planning, Guidance, and Control System for Autonomous Surface Vessel
Authors: Hinostroza M. A. , Xu Haitong , Guedes Soares C.
Published: November 2020

This paper presents a motion planning, guidance, and control system for an autonomous surface vessel in a practical maritime environment. The motion planning algorithm is based on the angle-guidance fast-marching square method (AFMS), and the guidance system is based on the line-of-sight (LOS) trajectory tracking algorithm. To validate the motion planning algorithm, numerical simulations were carried out to compute the optimal path in a static environment including various obstacles. The guidance and control system were tested with an autonomous surface vehicle (ASV) tracking a pre-established trajectory including static obstacles. The autonomous surface vehicle is a self-propelled scaled ship model of 2.5 m equipped with sensors and actuators, inertial measurement unit (IMU), global positioning system (GPS), propulsion direct current (DC) motors, and wireless communication. From the experiments and numerical simulations, a good agreement was found.
Simulation Analysis of the System Integrating Oxy-Fuel Combustion and Char Gasification
Authors: Liu Ruochen , Graebner Martin , Tsiava Remi , Zhang Ting , Xu Shenqi
Published: November 2020

To explore the feasibility of converting hot flue gas into valuable syngas through char gasification process, Aspen Plus is applied to evaluate the performance of the integrated system including oxy-combustion, pyrolysis, gasification, and flue gas recirculation. The impact of feedstock type (reed straw and municipal solid waste (MSW)), feeding rate (0.1–1 t/h), and flue gas recycle ratio (FGR) (10%–30%) is investigated. The economic analysis of the integrated system is also performed. The results indicate that higher oxygen consumption is required for biomass gasification to reach the same temperature as MSW gasification. The gasification temperature is 750 °C–950 °C under 10%–30% FGR. The CO + H2 content in syngas from biomass gasification is slightly higher than that from MSW gasification. For the integrated system, more natural gas (NG) can be saved and more fossil CO2 can be reduced under biomass gasification. When the feedstock input is 1 t/h, the fossil CO2 emission can be reduced by 70% when taking biomass, the CO2 reduction is double of that when taking MSW. The total OPEX cost can be 26% saved by biomass and 62% saved by MSW due to the government subsidy. If CO2 tax is considered, the advantage of biomass for saving OPEX cost will be more obvious.
Morphological ontogeny of Lopheremaeus mirabilis (Acari: Oribatida: Plateremaeidae), and comments on Lopheremaeus Paschoal

Authors: Seniczak Stanisław , Ivan Otilia , Kaczmarek Sławomir , Seniczak Anna
Published: November 2020

The morphological ontogeny of Lopheremaeus mirabilis (Csiszár 1962), the type species of Lopheremaeus Paschoal, 1988 (Plateremaeidae) is described and illustrated. The adult of this species has six pairs of notogastral setae (lp, h1, h2 and p-series), epimeral and anogenital hypertrichy, and 4–5 pairs of anal setae. The cuticle of juveniles is plicate, the larva lacks the gastronotal setae c3, la, lm and h3, the nymphs are multideficient (they lack also setae of d-series) and eupheredermous, i.e. they carry the exuvial scalps of previous instars on the gastronotum. In the adult, dorsal and ventral crests are present on all femora and trochanter III, and dorsal crest is present on trochanter IV, the nymphs have also dorsal and ventral crests on genua, whereas the larva has no crests. In all instars, seta d on all genua and tibiae is present, and all tarsi have basal bulb (containing muscles) and uniformly narrow distal stalk (with only tendons) at about mid-length. This species was reported only from Bulgaria, Bosnia-Herzegovina and North Macedonia, Romania and Georgia.
Social Media Usage During Live Sport Consumption: Generation Gap and Gender Differences Among Season Ticket Holders
Authors: Abdourazakou Yann , Deng Xuefei (Nancy) , Abeza Gashaw
Published: November 2020

This study sought to examine season ticket holders’ usage of social networking sites during live sport consumption. Informed by uses and gratifications theory, the study examined three types of social media use by fans—Twitter/Facebook posting, Instagram/Snapchat posting, and mobile app use—during a live game. Survey data of 400 season ticket holders of a professional National Basketball Association team were analyzed. Regression results showed that age was a significant predictor of the fans’ in-game social media use in terms of Instagram/Snapchat posting and mobile app use, whereas gender was a significant predictor of their Twitter/Facebook posting behavior. Moreover, the study showed a mixed result for the predicted moderating effect of the season ticket holders’ tenure on the predicted relationships between the two personal characteristics (age and gender) and the three types of social media use. Theoretical and practical implications of the study for sports marketing management are discussed.
Short-Term Precision Error of Body Composition Assessment Methods in Resistance-Trained Male Athletes
Authors: Farley Ava , Slater Gary J. , Hind Karen
Published: November 2020

Athletic populations require high-precision body composition assessments to identify true change. Least significant change determines technical error via same-day consecutive tests but does not integrate biological variation, which is more relevant for longitudinal monitoring. The aim of this study was to assess biological variation using least significant change measures from body composition methods used on athletes, including surface anthropometry (SA), air displacement plethysmography (BOD POD), dual-energy X-ray absorptiometry (DXA), and bioelectrical impedance spectroscopy (BIS). Thirty-two athletic males (age = 31 ± 7 years; stature = 183 ± 7 cm; mass = 92 ± 10 kg) underwent three testing sessions over 2 days using four methods. Least significant change values were calculated from differences in Day 1 Test 1 versus Day 1 Test 2 (same-day precision), as well as Day 1 Test 1 versus Day 2 (consecutive-day precision). There was high agreement between same-day and consecutive-day fat mass and fat-free mass measurements for all methods. Consecutive-day precision error in comparison with the same-day precision error was 50% higher for fat mass estimates from BIS (3,607 vs. 2,331 g), 25% higher from BOD POD (1,943 vs. 1,448 g) and DXA (1,615 vs. 1,204 g), but negligible from SA (442 vs. 586 g). Consecutive-day precision error for fat-free mass was 50% higher from BIS (3,966 vs. 2,276 g) and SA (1,159 vs. 568 g) and 25% higher from BOD POD (1,894 vs. 1,450 g) and DXA (1,967 vs. 1,461 g) than the same-day precision error. Precision error in consecutive-day analysis considers both technical error and biological variation, enhancing the identification of small, yet significant changes in body composition of resistance-trained male athletes. Given that change in physique is likely to be small in this population, the use of DXA, BOD POD, or SA is recommended.
Effects of Collagen Peptides on Recovery Following Eccentric Exercise in Resistance-Trained Males—A Pilot Study
Authors: Prowting Joel L. , Bemben Debra , Black Christopher D. , Day Eric A. , Campbell Jason A.
Published: November 2020

The authors sought to determine whether consuming collagen peptides (CP) enhances musculoskeletal recovery of connective tissues following a damaging exercise bout. Resistance-trained males consumed 15 g/day of CP (n = 7) or placebo (n = 8), and after 7 days, maximal voluntary isometric contraction (MVIC), countermovement jump height, soreness, and collagen turnover were examined. Five sets of 20 drop jumps were performed and outcome measures were collected 24, 48, and 120 hr postexercise. Countermovement jump height was maintained in the CP group at 24 hr (PRE = 39.9 ± 8.8 cm vs. 24 hr = 37.9 ± 8.9 cm, p = .102), whereas the CP group experienced a significant decline at 24 hr (PRE = 40.4 ± 7.9 cm vs. 24 hr = 35.5 ± 6.4 cm, p = .001; d = 0.32). In both groups, muscle soreness was significantly higher than PRE at 24 hr (p = .001) and 48 hr (p = .018) but not at 120 hr (p > .05). MVIC in both legs showed a significant time effect (left: p = .007; right: p = .010) over the 5-day postexercise period. Neither collagen biomarker changed significantly at any time point. CP supplementation attenuated performance decline 24 hr following muscle damage. Acute consumption of CP may provide a performance benefit the day following a bout of damaging exercise in resistance-trained males.
Effectiveness of Accentuated Eccentric Loading: Contingent on Concentric Load
Authors: Merrigan Justin J. , Tufano James J. , Falzone Michael , Jones Margaret T.
Published: November 2020

Purpose: To identify acute effects of a single accentuated eccentric loading (AEL) repetition on subsequent back-squat kinetics and kinematics with different concentric loads. Methods: Resistance-trained men (N = 21) participated in a counterbalanced crossover design and completed 4 protocols (sets × repetitions at eccentric/concentric) as follows: AEL65, 3 × 5 at 120%/65% 1-repetition maximum (1-RM); AEL80, 3 × 3 at 120%/80% 1-RM; TRA65, 3 × 5 at 65%/65% 1-RM; and TRA80, 3 × 3 at 80%/80% 1-RM. During AEL, weight releasers disengaged from the barbell after the eccentric phase of the first repetition and remained off for the remaining repetitions. All repetitions were performed on a force plate with linear position transducers attached to the barbell, from which eccentric and concentric peak and mean velocity, force, and power were derived. Results: Eccentric peak velocity (−0.076 [0.124] m·s−1; P = .01), concentric peak force (187.8 [284.4] N; P = .01), eccentric mean power (−145.2 [62.0] W; P = .03), and eccentric peak power (−328.6 [93.7] W; P < .01) during AEL65 were significantly greater than TRA65. When collapsed across repetitions, AEL65 resulted in slower eccentric velocity and power during repetition 1 but faster eccentric and concentric velocity and power in subsequent repetitions (P ≤ .04). When comparing AEL80 with TRA80, concentric peak force (133.8 [56.9] N; P = .03), eccentric mean power (−83.57 [38.0] W; P = .04), and eccentric peak power (−242.84 [67.3] W; P < .01) were enhanced. Conclusions: Including a single supramaximal eccentric phase of 120% 1-RM increased subsequent velocity and power with concentric loads of 65% 1-RM, but not 80% 1-RM. Therefore, AEL is sensitive to the magnitude of concentric loads, which requires a large relative difference to the eccentric load, and weight releasers may not need to be reloaded to induce performance enhancement.
Effective vaccine offers shot of hope for pandemic
Authors: Cohen Jon
Published: November 2020

Pioneering RNA candidate seems to work well, although its makers revealed scant data.
A divided Congress could narrow Biden's ambitious plans
Authors: Mervis Jeffrey
Published: November 2020

But president-elect has vowed to flex executive power.
India's COVID-19 teacher
Authors: Chandrashekhar Vaishnavi
Published: November 2020

Kerala health minister K. K. Shailaja has fought the pandemic with preparation, calm, and compassion.
Pandemic dooms Danish mink—and mink research
Authors: Lesté-Lasserre Christa
Published: November 2020

Mass culling ordered after discovery of mutations that may affect vaccine efficacy.
Rising from the ashes
Authors: Popkin Gabriel
Published: November 2020

An effort to breed North American ash trees that can resist a deadly beetle could accelerate the return of a forest icon.
A programmable fate decision landscape underlies single-cell aging in yeast
Authors: Li Yang , Jiang Yanfei , Paxman Julie , O’Laughlin Richard , Klepin Stephen , Zhu Yuelian , Pillus Lorraine , Tsimring Lev S. , Hasty Jeff , Hao Nan
Published: November 2020

Programmed aging in yeast cells

Following the fate of individual yeast cells has revealed aging to be more of a programmable decision process rather than a simple accumulation of deleterious events. Li
et al.
combined single-cell studies and mathematical modeling to show that yeast cells showed two different forms of aging: one with less ribosomal DNA silencing, in which nucleoli were degraded, and another with less heme accumulation and hemedependent transcription, in which mitochondria were more affected. Overexpression of the lysine deacetylase Sir2, which contributes to ribosomal DNA silencing, led to a third cell-aging fate in which the average life span was extended. If other cells age in similar ways, then this study may provide new ways to consider dynamics of aging and strategies to extend the health span.

Science
this issue p.
325
Astronomical context of Solar System formation from molybdenum isotopes in meteorite inclusions
Authors: Brennecka Gregory A. , Burkhardt Christoph , Budde Gerrit , Kruijer Thomas S. , Nimmo Francis , Kleine Thorsten
Published: November 2020

Timing Solar System formation

The oldest solids that formed in the Solar System are calcium-aluminium–rich inclusions (CAIs), small metallic droplets that were later incorporated into meteorites. The ages of CAIs are conventionally taken as the age of the Solar System, but which exact moment in star formation they correspond to has been unclear. Brennecka
et al.
measured molybdenum isotope ratios in CAIs and found a wide range of origins in both the inner and outer Solar System. They propose that CAIs formed from heterogeneous material accreting from the presolar nebula and that the ages of CAIs coincide with the Sun's transition from a protostar to a pre–main sequence star.

Science
, this issue p.
837