bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Modeling and Analysis of Steering Systems for Hybrid Vehicles
Authors: Mills Val D. , Wagner John R. , Dawson Darren M.
Published: November 2021

Hybrid vehicles integrate an internal combustion engine, electric motor with accompanying battery pack and generator, and potentially fuel cells to realize greater fuel economy and reduced emission levels. An attractive advantage of multiple energy sources is the increased travel range, reduced stationary recharging times, and availability of greater power for acceleration and payloads. A variety of operating scenarios exist for hybrid vehicle powertrains including engine (and belt driven generator), electric motor using battery back and/or fuel cell, and finally, engine and electric motor. Therefore, automotive subsystems such as hydraulic power steering cannot be consistently powered by a conventional belt driven hydraulic pump since the engine may be frequently turned-off to conserve energy. A need exists to investigate the dynamic behavior of various steering systems for hybrid vehicles in terms of platform steering characteristics, power consumption, and identification of performance requirements for a servo-motor steering system. In this paper, empirical and analytical mathematical models will be presented for power (e.g., hydraulic, electric, and steer-by-wire) rack and pinion steering units. The influence of vehicle and steering system nonlinearities will be introduced for greater accuracy in predicting the vehicle’s transient response. Representative results will be presented and discussed to investigate the response of the vehicle to different driver inputs as the steering system configurations are adjusted. An analysis of the numerical results will ultimately allow the prediction of vehicle trajectory, feedback torque, and power consumption during the driving maneuvers.
A Numerical Study of Three-Dimensional Natural Convective Heat Transfer From a Plate With a “Wavy” Surface
Authors: Oosthuizen Patrick H. , Garrett Matt
Published: November 2021

Natural convective heat transfer from a wide isothermal plate which has a “wavy” surface, i.e., has a surface which periodically rises and falls, has been numerically studied. The surface waves run parallel to the direction of flow over the surface and have a relatively small amplitude. Two types of wavy surface have been considered here — saw-tooth and sinusoidal. Surfaces of the type considered are approximate models of situations that occur in certain window covering applications, for example, and are also sometimes used to try to enhance the heat transfer rate from the surface. The flow has been assumed to be laminar. Because the surface waves are parallel to the direction of flow, the flow over the surface will be three-dimensional. Fluid properties have been assumed constant except for the density change with temperature that gives rise to the buoyancy forces, this being treated by means of the Boussinesq type approximation. The governing equations have been written in dimensionless form, the height of the surface being used as the characteristic length scale and the temperature difference between the surface temperature and the temperature of the fluid far from the plate being used as the characteristic temperature. The dimensionless equations have been solved using a finite-element method. Although the flow is three-dimensional because the surface waves are all assumed to have the same shape, the flow over each surface thus being the same, and it was only necessary to solve for the flow over one of the surface waves. The solution has the following parameters: the Grashof number based on the height, the Prandtl number, the dimensionless amplitude of the surface waviness, the dimensionless pitch of the surface waviness, and the form of the surface waviness (saw-tooth or sinusoidal). Results have been obtained for a Prandtl number of 0.7 for Grashof numbers up to 106. The effects of Grashof number, dimensionless amplitude and dimensionless pitch on the mean heat transfer rate have been studied. It is convenient to introduce two mean heat transfer rates, one based on the total surface area and the other based on the projected frontal area of the surface. A comparison of the values of these quantities gives a measure of the effectiveness of the surface waviness in increasing the mean heat transfer rate. The results show that while surface waviness increases the heat transfer rate based on the frontal area, the modifications of the flow produced by the surface waves are such that the increase in heat transfer rate is less than the increase in surface area.
An Interferometric Study of Convective Heat Transfer From an Irradiated Complex Window Assembly
Authors: Collins M. , Harrison S. J. , Naylor D. , Oosthuizen P. H.
Published: November 2021

The present experimental study examines the influence of heated, horizontal, and rotateable louvers on the convective heat transfer from a heated or cooled vertical isothermal surface. The system represents an irradiated Venetian blind adjacent to the indoor surface of a window. Detailed temperature field and local surface flux data were obtained using a Mach-Zehnder Interferometer for two window temperatures (warm and cool compared to ambient) and irradiation levels, two louver to plate spacings, and three louver angles. The results have been used to validate a previous numerical study, in which a steady, laminar, two-dimensional, conjugate conduction / convection / radiation finite element model of this problem had been developed.

The effect of the heated louvers on the heat transfer rate from the plate surface has been demonstrated and the results of the previous numerical study have been validated. With few exceptions, steady but periodic heat flux along the plate has been confirmed. More importantly, increased independence of the results from the louver angle as louver to plate distance increased was observed. Blind temperatures measured during the experiment also correlated well with those predicted numerically.
Tracer Dispersion in Stochastically Reconstructed Porous Media
Authors: Galani A. N. , Kainourgiakis M. E. , Kikkinides E. S. , Stubos A. K. , Chatzichristos C. , Muller J. , Papaioannou A.
Published: November 2021

Aim of the present study is the simulation of tracer transport in porous media. Three-dimensional images of porous materials are generated using stochastic reconstruction techniques. Two phases, one mobile and one immobile, fill the pore space. A simulated annealing algorithm determines the spatial distribution of the immobile phase. A finite amount (slug) of tracer is injected at a certain position of the domain and its concentration at the outlet is monitored with respect to time. The resulting response curves depend on the spatial distribution of the immobile phase, the diffusivity ratio and the relative solubility of the tracer in the two phases. A sensitivity study is performed to investigate the effect of the tracer partitioning coefficient and its diffusive properties in water and oil, on the predicted outlet concentration curve.
Effect of Subcooling on the Quenching of a Simulated Nuclear Fuel Rod
Authors: Sinha J. , Hochreiter L. E. , Cheung F. B.
Published: November 2021

An experimental study of the effect of liquid subcooling on the minimum film boiling temperature during quenching of a simulated nuclear fuel rod was performed under carefully controlled laboratory conditions. The rod was designed and fabricated with a proper combination of cladding and filler materials and was instrumented with embedded thermocouples distributed at various axial and radial locations. Quenching of the rods was done using distilled water with various degrees of subcooling as the working fluid. It was found that the rate of quenching depends strongly on the liquid subcooling. Multiple maxima were observed between film and nucleate boiling in the boiling curve for high subcoolings. Increasing subcooling had the effect of moving the entire boiling curve up and to the right, resulting in a considerably high minimum film boiling temperature. The strong effect of liquid subcooling on the quenching of a fuel rod should be properly accounted for in the study of reflood heat transfer in a nuclear reactor following a design-based accident.
Growth and Collapse of a Vapor Bubble Under Impulsive Heating
Authors: Prosperetti A. , Yuan He , Yin Zhizhong
Published: November 2021

In the first part of the paper a micropump based on the periodic growth and collapse of a single vapor bubble in a small channel is described. An explanation of the pumping principle and some preliminary experimental results are presented. In the implementation described the liquid is electrically conductive and is heated by passing a current through it; the same principle would be applicable to the case of non-conducting liquids by using heaters embedded in the channel walls. In the second part of the paper a model for the growth of a bubble onto a heater in a liquid is presented and some numerical results are discussed.
An Improved Time Domain Simulation for Dynamic Milling at Small Radial Immersions and Large Depths of Cut
Authors: Campomanes Marc L. , Altintas Yusuf
Published: November 2021

This paper presents an improved time domain model for milling, which can simulate vibratory cutting conditions at very small radial widths of cut and large depths of cut. The improved kinematics model allows simulation of very small radial immersions. The varying dynamics modeled along the cutting depth allows milling with very flexible cutters and/or flexible workpieces at very deep cuts to be simulated. The model can predict forces, surface finish, and chatter stability, accurately accounting for non-linear effects that are difficult to model analytically. The discretized cutter and workpiece kinematics and dynamic models are used to represent the exact trochoidal motion of the cutter, and to investigate the effects of forced vibrations and changing radial immersion due to deflection and vibrations on chatter stability. Three dimensional surface finish profiles are predicted and are compared to measured results. Stability lobes generated from the time domain simulation are also shown for various cases.
Using the Eigenvalues of Multivariate Spectral Matrices to Monitor Equipment
Authors: Roth John T.
Published: November 2021

There is a strong need in industry for monitoring techniques that are capable of tracking the health of cutting tools under varying conditions. Unfortunately, most monitoring techniques that are currently available are dependent on the cutting direction and/or the sensor orientation, limiting their effectiveness in the typical industrial environment. With this in mind, this research focuses on developing a monitoring technique that is independent of both of these factors. This is accomplished by using multivariate autoregressive models that are fit to the output from a tri-axial accelerometer. The work shows that the eigenvalues of multivariate spectral matrices, calculated at the machining frequencies, are sensitive to the condition of the tool. Furthermore, it is theoretically demonstrated that these eigenvalues are independent of the direction of cutting and the orientation of the sensor. This independence is verified experimentally through tests conducted under a variety of cutting directions and sensor orientations.
A Model for the Tool Temperature During Machining With a Rotary Tool
Authors: Kishawy Hossam A. , Gerber Andrew G.
Published: November 2021

In this paper a model is developed to analyze heat transfer and temperature distribution resulting during machining with rotary tools. The presented model is based on a finite-volume discretization approach applied to a general conservation of energy statement for the rotary tool and chip during machining. The tool rotational speed is modeled and its effect on the heat partitioning between the tool and the chip is investigated. The model is also used to examine the influence of tool speed on the radial temperature distribution on the tool rake face. A comparison between the predicted and previously measured temperature data shows good agreement. In general the results show that the tool-chip partitioning is influenced dramatically by increasing the tool rotational speed at low to moderate levels of tool speed. Also, there is an optimum tool rotational speed at which further increase in the tool rotational speed increases the average tool temperature.
Machining Simulation of Ductile Iron and its Constituents: Part II — Numerical Simulation and Experimental Validation of Machining
Authors: Chuzhoy L. , DeVor R. E. , Kapoor S. G.
Published: November 2021

To understand the influence of cast iron microstructure on its machinability, a numerical model that simulates machined material on a microstructure scale was developed. This microstructure-level model assembles individual constituents into a composite material based on microstructural composition, grain size, and distribution. Extensive experimentation was performed to determine strain, strain rate, temperature, and load history dependent material properties. The purpose of this work is to validate the microstructure-level model on machining of ductile iron and two of its constituents: pearlite and ferrite. Orthogonal cutting experiments were conducted of the three materials. The measured chip morphology and machining forces were compared with the model predictions, and a good correlation between them was found.
Stream of Variation Based Analysis and Synthesis of Measurement Schemes in Multi-Station Machining Systems
Authors: Djurdjanovic Dragan , Ni Jun
Published: November 2021

The choice of a measurement strategy in multi-station machining systems is crucial for subsequent successful identification of the root causes of machining errors. The measurement strategy selection is currently not a systematic process and it involves human and expert intervention. Recent advances in the linear state-space modeling of multi-station machining processes facilitate a more formal characterization of measurements in machining and a more systematic approach in the selection of the features that need to be measured. In this paper, we employ the Stream of Variation methodology to evaluate various measurement schemes in multi-station machining systems. Based on this evaluation, measurement synthesis procedures are presented, such that the resulting measurement scheme achieves a tradeoff between measurement uncertainty and the cost of measurements.
Heat Input Control in 3D Laser Cladding Based on Infrared Sensing
Authors: Hu Dongming , Wu Yunxin , Kovacevic Radovan
Published: November 2021

Solid Freeform Fabrication (SFF) methods for building metallic part, such as 3D laser cladding, are generally less stable and less repeatable than other rapid prototyping methods. The infrared image of the molten pool is a promising sensing technique for the closed-loop control of the cladding process. In this paper, the closed-loop control of heat input based on infrared image sensing in 3D laser cladding is introduced. A high frame-rate (up to 800frame/s) camera is installed coaxially at the top of the laser-nozzle setup. A full view of the infrared images of the molten pool can be acquired with a short nozzle-substrate distance in different scanning directions, eliminating the noise from the metal powder. The features of the images show a clear relationship with the variation of the cladding process parameters. The closed-loop control results show a great improvement in the geometrical accuracy and microstructure of the built part.
Development of the Cylindrical Wire Electrical Discharge Machining Process
Authors: Qu Jun , Shih Albert J. , Scattergood Ron
Published: November 2021

Results of applying the wire Electrical Discharge Machining (EDM) process to generate precise cylindrical forms on hard, difficult-to-machine materials are presented. The design of an underwater rotary spindle is first introduced. The spindle is added to a conventional two-axis wire EDM machine to enable the generation of free-form cylindrical geometry. Mathematical models for material removal rate and surface finish in cylindrical wire EDM of the free-form cylindrical workpiece are derived. Experiments are conducted for cylindrical and 2D wire EDM of brass and carbide work-materials. Comparing to the conventional 2D wire EDM of the same work-material, higher maximum material removal rates could be achieved in the cylindrical wire EDM. The surface finish and roundness of parts generated by cylindrical wire EDM at different part rotational speeds and wire traverse speeds are measured and analyzed.
A Precision Alignment Method to <100> Direction on (110) Silicon Wafer
Authors: Tseng Fan-Gang , Chang Kai-Chen
Published: November 2021

This paper proposes a novel pre-etch method to determine the lt;100gt; direction on (110) silicon wafers for bulk etching. Series of circular windows were arranged in an arc of radius 48.9 mm, and bulk-etched to form hexagonal shapes for crystal orientation finding. The corners of the hexagons can be used as an alignment reference for the indication of the lt;100gt; direction on (110) silicon wafers. This innovative approach has been demonstrated experimentally to give an orientation-alignment accuracy of ± 0.03° for (110) wafers with 4-inch diameter.
The Resonant Micro Fan for Fluidic Transport, Mixing and Particle Filtering
Authors: Linderman Ryan J. , Sett Subham , Bright Victor M.
Published: November 2021

A novel micro actuator for fluidic transport, mixing and particle filtering is presented. The technology uses a torsionally supported plate driven with an electrostatic signal at first-mode resonance to produce long-term reliable fluidic interactions at the chip level. Resonant frequencies from 10–20kHz have been tested with maximum fan deflections of approximately 30 microns. The resonant fans are fabricated using surface micro-machining techniques and flip-chip assembly. A simple flow visualization technique is also presented using laser illuminated smoke particles contained within the device packaging. The flow visualization setup allows for both overhead and side views as well as infinite ceiling and channel flow simulation in order to fully characterize the three dimensional flow produced by the resonant fans. Flow speeds of over 10 mm/s have been observed to exit single micro fans with large fan arrays producing over 2mL/min of volumetric flow. Fan testing in 600-micron deep channels has demonstrated the potential for suspended particle collection and filtering applications.
A Sub-Millimeter Solenoid Device for Trapping Paramagnetic Microbeads
Authors: García Luis D. , Cheung Lawrence C. , Mikkelsen James C. , Santiago Juan G. , Bernhardt Anthony F. , Malba Vincent
Published: November 2021

We present the design and preliminary evaluation of a paramagnetic microsphere trapping and separation device consisting of a copper solenoid wrapped around a 1.3 mm diameter glass capillary. The magnetization and subsequent dipole-dipole interaction of paramagnetic spheres under an applied magnetic field results in the formation of bead chains that persist and grow under the applied field, but quickly disperse upon field removal. The chaining of paramagnetic spheres is important to the design of magnetic-based separation devices because the viscous-drag-limited velocities of chains are typically several times larger than that of individual particles. We have performed a set of experiments designed to evaluate the performance of a sub-millimeter solenoid device including measurements of the temperature versus field strength of the device, observations of the controlled chain formation process, and preliminary observations regarding the maximum flow rate over which the bead chains can be held in place by magnetic forces. These results are applicable to the design and characterization of magnetically induced microsphere trapping and separation systems which use pressure driven flow.
Pt Heater/Sensor Microarray for Distributed Fluidic Cooling Assessment
Authors: Yoon Yong-Kyu , Allen Mark G.
Published: November 2021

This paper presents the design, fabrication, and characterization of a one-dimensional microscale heater array testbed that allows assessment of the spatial variation of temperature. Each pixel of the array acts as both a heater and a resistive temperature sensor simultaneously. The heater/sensor array is designed to mimic heat generation by line arrays of vertical-cavity surface emitting lasers (VCSELs), in order to assess microfluidic cooling schemes for these laser arrays. The array discussed in this paper is a linear micro array consisting of 100 heater elements, each of which has a 75μm pitch, and a nominal 20μmx20μm resistive heating area. Platinum is used for the heater as well as the resistive thermal sensor, since the resistance of platinum as a function of temperature shows extremely good linearity. A total of 101 probe pads are placed between the pixels to apply current for the heater function or to determine temperature for the sensor function. The array is fabricated on a silicon substrate and is diced to a size of 1.2mm × 8mm to match a typical VCSEL array size. Local heating and local cooling experiments (i.e., individual heater pixel or pixel groups) have been performed and demonstrate the versatility of the fabricated thermal testbed.
Fabrication of an Electromagnetic Micropump for Cerebrospinal Fluid Shunt
Authors: Kim Myung Sik , Kwon Kee Young , Lee Sang Wook , Yang Sang Sik
Published: November 2021

This paper presents the design and fabrication of a micropump for cerebrospinal fluid shunt. The micropump is to be implanted in hydrocephalus patients, The micropump consist of a corrugated parylene diaphragm and a set of nozzle and diffuser. The electromagnetic force drives the diaphragm. The static or dynamic characteristics of the fabricated devices have been obtained experimentally. The size of the micropump is 14 × 12 × 8mm3. The increased flow rate of the micropump is about 50 μl/min at operational range.
Characterization of Drying Techniques for Micro-Stereolithography
Authors: Wu Dongmin , Fang Nicholas , Sun Cheng , Zhang Xiang
Published: November 2021

Micro-stereolithography (μSL) is an advanced technology that enables fabrication of highly complex three-dimensional polymer microstructures out of UV curable resin. However, releasing of polymerized structures from un-polymerized resin is found to influence substantially the fabrication reliability of μSL, as the surface tension tends to push the fine structures together and cause collapse or adhesion. A theoretical model is developed to analyze the deflection and adhesion between thin polymer beams under capillary force. The detachment length of the test structures and solid surface tension of a typical μSL polymer (HDDA) are obtained experimentally. In this paper, we applied sublimation process to overcome the adhesion problem With the new drying process, no adhesion phenomenon was observed.
Sound Radiation From a Flow-Excited Rectangular Plate With Visco-Elastic Supports
Authors: Park Junhong , Siegmund Thomas , Mongeau Luc
Published: November 2021

In road vehicles, one dominant “wind noise” generating mechanism is the flow-induced vibration of side-glass windows. Side-glass windows are excited by unsteady surface pressures associated with turbulent flows over the vehicle body. In this study, experiments were performed in order to investigate the sound radiated by a seal-supported, rectangular aluminum panel excited by separated/reattached flow. The primary goal of this investigation was to assess the influence of seal mechanical properties and geometries on the sound transmission loss of the side-glass window. Experimental modal analysis test was conducted to accurately measure the resonance frequencies and the modal damping ratios of the panel. Surface pressure measurements were performed using small-diameter condenser microphones. The influence of the excitation spectrum on the radiated noise level was determined. The results were compared with theoretical predictions obtained using an analytical model based on a variational formulation of the problem. The flow-excited vibration response was predicted accurately for two different turbulent flows. The vibration energy dissipation at the sealing system reduced the amplitude of the plate vibration at resonance and the radiated sound.
Shape Sensitivity Analysis Applied to Exterior Acoustics
Authors: Feijóo Gonzalo R. , Oberai Assad A. , Pinsky Peter M.
Published: November 2021

We present a method to calculate the derivative of a functional that depends on the shape of a body immersed in an acoustic media. The functional depends implicitly on the shape through the solution of an exterior acoustic problem. The derivative is calculated in terms of the solution of the primal problem and an auxiliary problem, the adjoint problem. An important aspect of this method is that the cost of calculating the derivative is independent of the number of parameters used to represent the shape of the body. This allows for efficient solution of optimization problems in structural acoustics.
Investigation of the Transmission Loss Behavior of an Advanced Grid-Stiffened Structure
Authors: Vipperman Jeffrey S. , Li Deyu , Avdeev Ilya
Published: November 2021

The vibroacoustic behavior of an advanced grid-stiffened (AGS) composite structure which is reminiscent of a mock-scale fairing has been investigated. Both finite element analysis (FEA) and experimental modal analysis have been performed and the results corroborated. The lightly-coupled structurally-dominant modes and acoustically-dominant modes can be used to determine the structural acoustic coupling coefficients for the fairing. In addition, the certain critical structural acoustic frequencies have been computed. These results can be assimilated in order to provide insight into the theoretical performance limits of various potential transmission control mechanisms, including geometry or property tuning, the inclusion of passive control materials, or the addition of secondary structural and/or acoustic control inputs.
The Role of the National Energy Technology Laboratory (NETL) in the Advancement of Energy and Environmental Technologies: Reference Material
Authors: Baldwin Arthur L.
Published: November 2021

• Why is Energy Important?

• Energy, and the Future

• What is NETL?

• NETL’s Role in Energy and Environmental Technology Advancement

• Partnerships
Bell's theorem, non-computability and conformal cyclic cosmology: A top-down approach to quantum gravity
Authors: Palmer T. N.
Published: November 2021

This paper draws on a number of Roger Penrose's ideas—including the non-Hamiltonian phase-space flow of the Hawking Box, conformal cyclic cosmology, non-computability, and gravitationally induced quantum state reduction—in order to propose a radically unconventional approach to quantum gravity: Invariant Set Theory (IST). In IST, the fundamental laws of physics describe the geometry of the phase portrait of the universe as a whole: “quantum” process is associated with fine-scale fractal geometry, “gravitational” process with larger-scale heterogeneous geometry. With this, it becomes possible to explain the experimental violation of Bell inequalities without having to abandon key ingredients of general relativity: determinism and local causality. Ensembles in IST can be described by complex Hilbert states over a finite set ℂp of complex numbers, where p is a large finite integer. The quantum mechanics of finite-dimensional Hilbert spaces is emergent as a singular limit when p→∞. A small modification to the field equations of general relativity is proposed to make it consistent with IST.
Reading aloud in clear speech reduces sentence recognition memory and recall for native and non-native talkers
Authors: Keerstock Sandie , Smiljanic Rajka
Published: November 2021

Speaking style variation plays a role in how listeners remember speech. Compared to conversational sentences, clearly spoken sentences were better recalled and identified as previously heard by native and non-native listeners. The present study investigated whether speaking style variation also plays a role in how talkers remember speech that they produce. Although distinctive forms of production (e.g., singing, speaking loudly) can enhance memory, the cognitive and articulatory efforts required to plan and produce listener-oriented hyper-articulated clear speech could detrimentally affect encoding and subsequent retrieval. Native and non-native English talkers' memories for sentences that they read aloud in clear and conversational speaking styles were assessed through a sentence recognition memory task (experiment 1; N = 90) and a recall task (experiment 2; N = 75). The results showed enhanced recognition memory and recall for sentences read aloud conversationally rather than clearly for both talker groups. In line with the “effortfulness” hypothesis, producing clear speech may increase the processing load diverting resources from memory encoding. Implications for the relationship between speech perception and production are discussed.
Broadband ultra-long acoustic jet based on double-foci Luneburg lens
Authors: Zhao Liuxian , Horiuchi Timothy , Yu Miao
Published: November 2021

In this paper, a gradient index acoustic metamaterial is proposed based on the concept of the optical modified generalized Luneburg lens (MGLL). With the MGLL, double-foci and high energy density between the two foci can be achieved, which enables the realization of an ultra-long acoustic jet between the two foci. This capability of the MGLL is theoretically and numerically demonstrated with an acoustic metamaterial lens. Numerical simulation results show that based on this design, ultra-long acoustic jets with a jet length of up to 30 λ can be achieved, covering both the near field and far field.
Evidence-Based Classification in Powerchair Football: Determining the Determinants
Authors: Barfield J.P. , Williams Stephanie , Currie Madison R. , Guo Xiuyan
Published: November 2021

The purpose of this study was to initiate the development of an evidence-based sport classification system for powerchair football, a sport that serves athletes with physical impairments. Sport classification is designed to increase participation by minimizing the impact of impairment on competition outcome, and powerchair football lacks an evidence-based system of classification which is required of Paralympic sports. A number of approaches were used to build the theoretical model of sport performance (Step 2 of the International Paralympic Committee model). Key sport activities were identified through surveys of stakeholders and underlying determinants of those key activities were identified through game and database analyses. Current findings support drive control, ball control, communication, and adjustment to the ball as key activities in powerchair football with joint-specific strength and range of motion, sensory, and neurological variables identified as underlying determinants.
OCT4-mediated inflammation induces cell reprogramming at the origin of cardiac valve development and calcification
Authors: Farrar Emily J. , Hiriart Emilye , Mahmut Ablajan , Jagla Bernd , Peal David S. , Milan David J. , Butcher Jonathan T. , Puceat Michel
Published: November 2021

Cell reprogramming is at the origin of valve calcification.
High-impact
FN1
mutation decreases chondrogenic potential and affects cartilage deposition via decreased binding to collagen type II
Authors: van Hoolwerff Marcella , Rodríguez Ruiz Alejandro , Bouma Marga , Suchiman H. Eka D. , Koning Roman I. , Jost Carolina R. , Mulder Aat A. , Freund Christian , Guilak Farshid , Ramos Yolande F. M. , Meulenbelt Ingrid
Published: November 2021

Fibronectin binding to collagen type II is crucial for articular chondrocytes to stay in a healthy steady state.
Disruption of autophagy by increased 5-HT alters gut microbiota and enhances susceptibility to experimental colitis and Crohn’s disease
Authors: Haq Sabah , Wang Huaqing , Grondin Jensine , Banskota Suhrid , Marshall John K. , Khan Irfan I. , Chauhan Usha , Cote Francine , Kwon Yun Han , Philpott Dana , Brumell John H. , Surette Michael , Steinberg Gregory R. , Khan Waliul I.
Published: November 2021

Elevated gut serotonin inhibits autophagy via mTOR promoting a disrupted microbiota and enhanced susceptibility to colitis.
Making peace with oil palm
Authors: Rochmyaningsih Dyna
Published: November 2021

Some scientists are helping make palm plantations greener. Others say that doing so legitimizes a destructive industry.
Boosting engineered T cells
Authors: Singh Nathan , June Carl H.
Published: November 2021

Vaccines augment the antitumor activity of cellular therapy
Stronger artificial muscles, with a twist
Authors: Tawfick Sameh , Tang Yichao
Published: November 2021

Tailored fiber-shaped actuators with twisted and coiled designs have high energy densities
Mapping global protein contacts
Authors: Vajda Sandor , Emili Andrew
Published: November 2021

Genome-scale coevolution experiments expand bacterial protein interactomes
Protecting fetal development
Authors: Kellam Paul , Weiss Robin A.
Published: November 2021

Control of cell fusion in the placenta affects the balance between health and harm
Balancing science and security
Authors: Coleman Mary Sue
Published: November 2021

Federal elected officials and members of the United States intelligence community have expressed concern about the security of the nation's scientific and technological information, articulating worries about China, Russia, and Iran. The fears include potential academic espionage, theft of intellectual property, and threats to academic integrity. As federal policy-makers respond, it is critical that they work with the scientific community to balance securing strategically important information with maintaining the free flow of fundamental scientific knowledge and international talent necessary for scientific progress. History is a guide to striking this balance.
Mitochondria—More than just ATP for CTLs
Authors: Maltzman Jonathan S.
Published: November 2021

Cytotoxic T cells require protein synthesis in mitochondria for prolonged killing.
“Extreme dinosaurs” and the continuing evolution of dinosaur paleoart
Authors: Allmon Warren D.
Published: November 2021

Humans have made visual representations of what they think dinosaurs looked like since before the term and concept of “dinosaur” were first published in 1842. Over the next 175 years, these images have varied widely. The current era of dinosaur paleobiology began in the late 1960s and emphasized scientific and artistic conceptions of dinosaurs as more active and diverse in their metabolism, ecology, and behavior than previously thought. Over the past 25 years in particular, the rise of computer-generated images and the discovery of spectacularly preserved fossils from the Early Cretaceous of China and elsewhere have further revolutionized our understanding of the biology and external appearance (especially integument) of dinosaurs. Yet despite these innovations, dinosaur paleoart is still fundamentally shaped by the same basic set of influences that affected previous, now-discarded, images. These include (1) the fossils; (2) debates about which modern animals are the best bases for uniformitarian comparison with extinct taxa; (3) extrapolation (i.e., how far can we go from the known to the unknown); (4) the enabling effects of new artistic techniques; and (5) the ever-present pressures of the marketplace.
Mexico: Basement framework and pre-Cretaceous stratigraphy
Authors: Martens Uwe C. , Garza Roberto S. Molina
Published: November 2021

Provenance determinations of sediment deposited in circum–Gulf of Mexico basins rely on understanding the geologic elements present in the basement provinces located from northeast Mexico to Honduras. Relevant geologic features of these provinces are herein summarized in text and pictorial form, and they include the Huizachal-Peregrina uplift, western Gulf of Mexico, Huayacocotla, Zapoteco, Mixteca, Xolapa, Juchatengo, Cuicateco, Mixtequita, south-central Chiapas, southeast Chiapas, western Guatemala, central Guatemala, Maya Mountains, and the Chortis block. We recognized basement elements of local character that serve as fingerprints for specific source areas. However, many elements are ubiquitous, such as 1.4–0.9 Ga, high-grade metamorphic rocks that occur both as broad exposures and as inliers in otherwise reworked crust. Xenocrystic and detrital zircon of Mesoproterozoic age is very common and hence not diagnostic of provenance. Neoproterozoic rocks are very scarce in Mexican basement provinces. However, Ediacaran–Cambrian detrital zircon grains are found in Mexican Paleozoic strata; these were possibly derived from distant sources in Gondwana and Pangea. Ordovician–Silurian magmatism is present in approximately half the provinces; magmatic detrital zircon of such age is somewhat informative in terms of provenance. More useful populations are detrital zircon grains with Ordovician–Silurian metamorphic overgrowth, which seem to be mainly sourced from the Mixteca region or the southern Chiapas Massif. Devonian basement has only been discovered in the Maya Mountains of Belize, and detrital zircon of such age seems to be characteristic of that source. A similar case can be made about Carboniferous zircon and the Acatlán Complex, Middle Pennsylvanian zircon and Juchatengo plutons, and Late Triassic zircon and the basement exposed in central Guatemala. In all these cases, the age and geographic extent of the zircon source are restricted and serve as a distinct fingerprint. Plutons of Permian–Early Triassic age are widespread, and detrital zircon grains from them are rather nonspecific indicators of source area. Future dating of detrital white mica using 40Ar-39Ar could help in recognizing Carboniferous–Triassic schist from more restricted schist occurrences such as west Cuicateco (Early Cretaceous) and central Guatemala (Late Cretaceous).
Supplemental Material: The Guerrero terrane, a para-autochthonous block on the paleo-Pacific continental margin of North America: Evidence from zircon U-Pb dating and Hf isotopes
Authors: Ortega-Flores Berlaine , al. et
Published: November 2021

Table S1: Results of U-Pb geochronology; and Table S2: Results of Hf isotope analysis
Immune thrombocytopenic purpura secondary to SARS-CoV-2 infection in a child with acute lymphoblastic leukaemia: a case report and review of literature
Authors: Dongre Amol , Jameel Patel Zeeshan , Deshmukh Mahesh , Bhandarkar Shweta
Published: November 2021

Immune thrombocytopenic purpura (ITP) is characterised by isolated thrombocytopenia which may be idiopathic or due to a secondary aetiology. ITP is being increasingly recognised secondary to SARS-CoV-2 infection in the current pandemic. Here, we report a case of a five-and-a-half-year-old female child on maintenance chemotherapy for acute lymphoblastic leukaemia who subsequently developed ITP secondary to SARS-CoV-2 infection. Our patient had prolonged thrombocytopenia secondary to ITP, requiring the use of second-line agents including romiplostim and eltrombopag. This is a unique case where ITP was recognised secondary to SARS-CoV-2. In such cases of thrombocytopenia, ITP should be considered as an important differential in addition to relapse of leukaemia or thrombocytopenia due to chemotherapy drugs.
Ethical and sociocultural challenges in managing dead bodies during epidemics and natural disasters
Authors: Suwalowska Halina , Amara Fatu , Roberts Nia , Kingori Patricia
Published: November 2021

Background

Catastrophic natural disasters and epidemics claim thousands of lives and have severe and lasting consequences, accompanied by human suffering. The Ebola epidemic of 2014–2016 and the current COVID-19 pandemic have revealed some of the practical and ethical complexities relating to the management of dead bodies. While frontline staff are tasked with saving lives, managing the bodies of those who die remains an under-resourced and overlooked issue, with numerous ethical and practical problems globally.

Methods

This scoping review of literature examines the management of dead bodies during epidemics and natural disasters. 82 articles were reviewed, of which only a small number were empirical studies focusing on ethical or sociocultural issues that emerge in the management of dead bodies.

Results

We have identified a wide range of ethical and sociocultural challenges, such as ensuring dignity for the deceased while protecting the living, honouring the cultural and religious rituals surrounding death, alleviating the suffering that accompanies grieving for the survivors and mitigating inequalities of resource allocation. It was revealed that several ethical and sociocultural issues arise at all stages of body management: notification, retrieving, identification, storage and burial of dead bodies.

Conclusion

While practical issues with managing dead bodies have been discussed in the global health literature and the ethical and sociocultural facets of handling the dead have been recognised, they are nonetheless not given adequate attention. Further research is needed to ensure care for the dead in epidemics and that natural disasters are informed by ethical best practice.
Prevalence, incidence, and risk factors for myopia among urban and rural children in southern China: protocol for a school-based cohort study
Authors: Chen Xin , Ye Guofang , Zhong Yuxin , Jin Ling , Liang Xiaoling , Zeng Yangfa , Zheng Yingfeng , lan Morgan , Liu Yizhi
Published: November 2021

Introduction

Myopia is the common cause of reduced uncorrected visual acuity among school-age children. It is more prevalent in urban than in rural areas. Although many myopia studies have focused on the effect of urbanisation, it remains unclear how visual experience in urban regions could affect childhood myopia. This study aims to investigate the incidence and prevalence of myopia among school-age children in urban and rural settings, thereby identifying the environmental factors that affect the onset and progression of myopia.

Methods and analysis

A school-based cohort study will be conducted. We will enroll all first-grade students from an urban (10 primary schools) and a rural (10 primary schools) regions of Zhaoqing city, China. Over 3-year follow-up period, students will receive detailed eye examinations annually and complete questionnaires about living habits and environment. In a 5% random subsample of the cohort, physical activity, light intensity and eye-tracking data will be obtained using wearable devices, and high-resolution macular images will be obtained by optical coherence tomography (OCT). The primary outcome is incident myopia, defined as myopia (spherical equivalent refractive of at least −0.5D) detected during follow-up among those without myopia at baseline.

Ethics and dissemination

Ethics approval was obtained from the ethics committee of the Zhongshan Ophthalmic Center (number: 2019KYPJ171). Study findings will be published in a peer-reviewed journal.

Trial registration number

NCT04219228.
Secondary attack rate of COVID-19 among contacts and risk factors, Tamil Nadu, March–May 2020: a retrospective cohort study
Authors: Karumanagoundar Kolandaswamy , Raju Mohankumar , Ponnaiah Manickam , Kaur Prabhdeep , viswanathan Vidhya , Rubeshkumar Polani , Sakthivel Manikandanesan , Shanmugiah Porchelvan , Ganeshkumar Parasuraman , Muthusamy Santhosh Kumar , Sendhilkumar Muthappan , Venkatasamy Vettrichelvan , Sambath Irene , Ilangovan Kumaravel , Murugesan Jagadeesan , Govindarajan Rameshkumar , Shanmugam Soundammal , Rajarathinam Selvakumar , Suresh KST , Varadharajan M , Thiagarajan Manivannan , Jagadeeshkumar K , Ganesh Velmurugan , Kumar Sateesh , Venkatesan Prakash , Nallathambi Yogananth , Palani Sampath , Selvavinayagam TS , Reddy Madhusudhan , Rajesh Beela , Murhekar Manoj V
Published: November 2021

Objective

To describe the characteristics of contacts of patients with COVID-19 case in terms of time, place and person, to calculate the secondary attack rate (SAR) and factors associated with COVID-19 infection among contacts.

Design

A retrospective cohort study

Setting and participants

Contacts of cases identified by the health department from 14 March 2020to 30 May 2020, in 9 of 38 administrative districts of Tamil Nadu. Significant proportion of cases attended a religious congregation.

Outcome measure

Attack rate among the contacts and factors associated with COVID-19 positivity.

Results

We listed 15 702 contacts of 931 primary cases. Of the contacts, 89% (n: 14 002) were tested for COVID-19. The overall SAR was 4% (599/14 002), with higher among the household contacts (13%) than the community contacts (1%). SAR among the contacts of primary cases with congregation exposure were 5 times higher than the contacts of non-congregation primary cases (10% vs 2%). Being a household contact of a primary case with congregation exposure had a fourfold increased risk of getting COVID-19 (relative risk (RR): 16.4; 95% CI: 13 to 20) than contact of primary case without congregation exposure. Among the symptomatic primary cases, household contacts of congregation primaries had higher RR than household contacts of other cases ((RR: 25.3; 95% CI: 10.2 to 63) vs (RR: 14.6; 95% CI: 5.7 to 37.7)). Among asymptomatic primary case, RR was increased among household contacts (RR: 16.5; 95% CI: 13.2 to 20.7) of congregation primaries compared with others.

Conclusion

Our study showed an increase in disease transmission among household contacts than community contacts. Also, symptomatic primary cases and primary cases with exposure to the congregation had more secondary cases than others.
Perspectives of primary care physicians on acceptance and barriers to COVID-19 vaccination
Authors: Day Philip , Strenth Chance , Kale Neelima , Schneider F David , Arnold Elizabeth Mayfield
Published: November 2021

Objectives

The purpose of this study was to examine the perspectives of primary care physicians in Texas around vaccine acceptance and potential patient barriers to vaccination. National surveys have shown fluctuating levels of acceptance for COVID-19 vaccination, and primary care physicians could play a crucial role in increasing vaccine uptake.

Design

This study employed a cross-sectional anonymous survey design to collect data using an online questionnaire. Participants were asked about vaccination practices and policies at their practice site, perceptions of patient and community acceptance and confidence in responding to patient vaccine concerns.

Setting

From November 2020 to January 2021, family medicine physicians and paediatricians completed an online questionnaire on COVID-19 vaccination that was distributed by professional associations.

Participants

The survey was completed by 573 practising physicians, the majority of whom identified as family medicine physicians (71.0%) or paediatricians (25.7%), who are currently active in professional associations in Texas.

Results

About three-fourths (74.0%) of participants reported that they would get the vaccine as soon as it became available. They estimated that slightly more than half (59.2%) of their patients would accept the vaccine, and 67.0% expected that the COVID-19 vaccine would be accepted in their local community. The majority of participants (87.8%) reported always, almost always or usually endorsing vaccines, including high levels of intention to recommend COVID-19 vaccination (81.5%). Participants felt most confident responding to patient concerns related to education about vaccine types, safety and necessity and reported least confidence in responding to personal or religious objections to COVID-19 vaccination.

Conclusions

The majority of the physicians surveyed stated that they would receive the COVID-19 vaccination when it was available to them and were confident in their ability to respond to patient concerns. With additional education, support and shifting COVID-19 vaccinations into primary care settings, primary care physicians can use the trust they have built with their patients to address vaccine hesitancy and potentially increase acceptance and uptake.