bluuebunny/crossref_metadata_2025_split huggingface dataset:
A conserved and seemingly redundant Escherichia coli biotin biosynthesis gene expressed only during anaerobic growth
Authors: Song Xuejiao , Cronan John E. 
Published: October 2021

AbstractBiotin is an essential metabolic cofactor and de novo biotin biosynthetic pathways are widespread in microorganisms and plants. Biotin synthetic genes are generally found clustered into bio operons to facilitate tight regulation since biotin synthesis is a metabolically expensive process. Dethiobiotin synthetase (DTBS) catalyzes the penultimate step of biotin biosynthesis, the formation of 7,8‐diaminononanoate (DAPA). In Escherichia coli, DTBS is encoded by the bio operon gene bioD. Several studies have reported transcriptional activation of ynfK a gene of unknown function, under anaerobic conditions. Alignments of YnfK with BioD have led to suggestions that YnfK has DTBS activity. We report that YnfK is a functional DTBS, although an enzyme of poor activity that is poorly expressed. Supplementation of growth medium with DAPA or substitution of BioD active site residues for the corresponding YnfK residues greatly improved the DTBS activity of YnfK. We confirmed that FNR activates transcriptional level of ynfK during anaerobic growth and identified the FNR binding site of ynfK. The ynfK gene is well conserved in γ‐proteobacteria.
Transgenerational effects of obesogenic diets in rodents: A meta‐analysis
Authors: Anwer Hamza , Morris Margaret J. , Noble Daniel W. A. , Nakagawa Shinichi , Lagisz Malgorzata 
Published: October 2021

SummaryObesity is a major health condition that affects millions worldwide. There is an increased interest in understanding the adverse outcomes associated with obesogenic diets. A multitude of studies have investigated the transgenerational impacts of maternal and parental obesogenic diets on subsequent generations of offspring, but results have largely been mixed. We conducted a systematic review and meta‐analysis on rodent studies to elucidate how obesogenic diets impact the mean and variance of grand‐offspring traits. Our study focused on transgenerational effects (i.e., F2 and F3 generations) in one‐off and multigenerational exposure studies. From 33 included articles, we obtained 407 effect sizes representing pairwise comparisons of control and treatment grand‐offspring groups pertaining to measures of body weight, adiposity, glucose, insulin, leptin, and triglycerides. We found evidence that male and female grand‐offspring descended from grandparents exposed to an obesogenic diet displayed phenotypes consistent with metabolic syndrome, especially in cases where the obesogenic diet was continued across generations. Further, we found stronger evidence for the effects of grand‐maternal than grand‐paternal exposure on grand‐offspring traits. A high‐fat diet in one‐off exposure studies did not seem to impact phenotypic variation, whereas in multigenerational exposure studies it reduced variation in several traits.
Trends in fever case management for febrile inpatients in a low malaria incidence setting of Tanzania
Authors: Madut Deng B. , Rubach Matthew P. , Bonnewell John P. , Cutting Elena R. , Carugati Manuela , Kalengo Nathaniel , Maze Michael J. , Morrissey Anne B. , Mmbaga Blandina T. , Lwezaula Bingileki F. , Kinabo Grace , Mbwasi Ronald , Kilonzo Kajiru G. , Maro Venance P. , Crump John A. 
Published: October 2021

AbstractObjectivesIn 2010, WHO published guidelines emphasising parasitological confirmation of malaria before treatment. We present data on changes in fever case management in a low malaria transmission setting of northern Tanzania after 2010.MethodsWe compared diagnoses, treatments and outcomes from two hospital‐based prospective cohort studies, Cohort 1 (2011–2014) and Cohort 2 (2016–2019), that enrolled febrile children and adults. All participants underwent quality‐assured malaria blood smear‐microscopy. Participants who were malaria smear‐microscopy negative but received a diagnosis of malaria or received an antimalarial were categorised as malaria over‐diagnosis and over‐treatment, respectively.ResultsWe analysed data from 2098 participants. The median (IQR) age was 27 (3–43) years and 1047 (50.0%) were female. Malaria was detected in 23 (2.3%) participants in Cohort 1 and 42 (3.8%) in Cohort 2 (p = 0.059). Malaria over‐diagnosis occurred in 334 (35.0%) participants in Cohort 1 and 190 (17.7%) in Cohort 2 (p < 0.001). Malaria over‐treatment occurred in 528 (55.1%) participants in Cohort 1 and 196 (18.3%) in Cohort 2 (p < 0.001). There were 30 (3.1%) deaths in Cohort 1 and 60 (5.4%) in Cohort 2 (p = 0.007). All deaths occurred among smear‐negative participants.ConclusionWe observed a substantial decline in malaria over‐diagnosis and over‐treatment among febrile inpatients in northern Tanzania between two time periods after 2010. Despite changes, some smear‐negative participants were still diagnosed and treated for malaria. Our results highlight the need for continued monitoring of fever case management across different malaria epidemiological settings in sub‐Saharan Africa.
A New Approach to Solve Inverse Boundary Design of a Radiative Enclosure With Specular–Diffuse Surfaces
Authors: Mosavati Babak , Mosavati Maziar 
Published: October 2021

Abstract
The maintenance of uniform temperature distribution affects the efficiency in most industrial applications. In this study, a novel strategy has been developed for inverse radiative boundary design problems in radiant enclosures with participating medium. This study presents the Backward Monte Carlo method to investigate the inverse boundary design of an enclosure composed of specular and diffuse surfaces. A new optimized Monte Carlo method is proposed to determine the temperature distribution of heaters to achieve desirable prescribed uniform heat flux on the design surfaces. The proposed approach is highly efficient and simple to implement with appropriate results. The evaluated heat fluxes on design surfaces and temperature distribution of heaters are compared with the case where the reradiating walls are assumed to be perfectly diffuse. In the proposed approach, for a specific range of specularity, the absorptivity of the reradiating surfaces does not affect the temperature distribution of heaters. Compared to the diffuse walls, the specular walls have a more uniform temperature distribution and heat flux of heaters. This finding will provide insight into solar furnaces design to enhance temperature uniformity, making specular surfaces suitable in many industrial applications.
Hydrocavitation Piezoelectric Ocean Wave Energy Harvesting
Authors: Arias Francisco J. , De Las Heras Salvador 
Published: October 2021

AbstractThe possibility to convert the ocean wave energy into electrical energy by piezoelectric layers has excited the imagination of ocean wave energy conversion designers for decades owing to its relative robustness (no mechanical parts are needed), the capability to cover large areas, and its relatively low cost. Unfortunately, the very poor efficiency featured by piezoelectric layers in the application of ocean waves has prevented its application even as an energy harvester. Here, the possibility to induce hydrocavitation and then working with higher local pressures for substantial efficiency enhancement is discussed. Utilizing a simplified geometrical and physical model and the linear and potential theory, a first theoretical estimation for the energy enhancement driven by hydrocavitation was calculated. It was found that the power could be enhanced several orders of magnitude which, although still rather low, however, the enhanced electric outputs can be used now as energy harvesters. Additional R&D is encouraged in order to explore the possibilities to harness hydrocavitation to enhance piezoelectric converters.
Photo-Responsive Hydrogel Microneedles With Interlocking Control for Easy Extraction in Sustained Ocular Drug Delivery
Authors: Amer Maher , Ni Xiang , Xian Ming , Chen Roland K. 
Published: October 2021

Abstract
Microneedle arrays provide a minimally invasive platform for ocular drug delivery. Self-adhesive microneedle arrays, which incorporate barb-like locking features, have been developed to secure the array in place without using any adhesive. However, these locking features may increase extraction forces when removing the microneedle array once the drug delivery is completed. In this study, we demonstrated a photoresponsive hydrogel microneedle array that can self-adhere to the application site upon swelling and can deswell for easy removal when illuminated with light. The photoresponsive hydrogel microneedle arrays were made by a mixture of polyvinyl alcohol and spiropyran-conjugated N-isopropylacrylamide (NIPPAM). Experimental results show a significant decrease in extraction force after the microneedle of 20% spiropyran-conjugated NIPPAM was illuminated with light for 15 min. At the same time, the width of the interlocking feature also deswelled by 20% due to the photoresponsive behavior. However, the addition of the spiropyran-conjugated NIPPAM also weakens the mechanical properties of the microneedle and thus increase in insertion force.
Influence of Deep-Discharge Rate on Recycle Process of High Energy Density Traction Batteries
Authors: Liu Shiqiang , Ma Tianyi , Wang Fang , Bai Guangli , Wei Zhen , Wei Mohan , Li Yupeng , Lin Chunjing , Hu Jian , Hao Weijian 
Published: October 2021

AbstractLithium-ion traction batteries are increasingly used in transportation, such as electric vehicles and buses. To reduce the life cycle cost of traction batteries, material recycling is a technical route that must be considered. Deep discharge is one of the necessary steps in battery disassembly and material recycle; however, the thermal stability and internal material changes caused by deep discharge can affect the subsequent recycling processes. In this paper, we study the influence of deep-discharge rate on the recycling process of a commercial traction battery with LiNi1/3Co1/3Mn1/3O2 cathode and a graphite anode. Combine with multi-analysis methods, we systematically explored the evolution of an electrode structure under different deep-discharge current densities. Our results show that the deep-discharge current density has different effects on the internal structure of the battery and may affect its thermal safety.
Parametric Study on Wing-Lambda-Shock Formation
Authors: Chainok Sirikorn , Rungroch Thanapol , Chairach Pattarasuda , Prapamonthon Prasert , Yooyen Soemsak , Yin Bo , Yang Guowei , Ju Shengjun 
Published: October 2021

Abstract
It is well-known that a wing is one of the most important parts of an aircraft as it is used to generate lift force. According to a wing moving at sufficiently high subsonic speeds, the flow speed on the wing’s upper surface can be supersonic due to acceleration through the curvature-created suction, thereby forming a shock wave in a lambda shape. Additionally, the lambda shock can interact with the boundary layer flow. These phenomena relate to disturbances in the flow field, including flow separation, thus causing undesirable effects on lift production. Hence, a better understanding of the phenomenon of wing-lambda-shock formation and its nature is essential. This study presents a numerical investigation of the lambda-shock formation on an ONERA M6 wing, which is known as a swept, semi-span wing with no twist, under parametric effects of angle-of-attack, and free-stream Mach number, which is increased up to the supersonic regime. The pressure coefficients obtained by simulations are validated by open data. Then, numerical results in terms of the local pressure coefficient, local Mach number, averaged lift and drag coefficients, and λ-shape characteristics based on Mach number and pressure coefficients are discussed under an investigated range of the parameters. Results show that the angle-of-attack and free-stream Mach number can affect the lambda shock formation on the wing upper surface physically. Specifically, an iso-sonic surface with lambda shock waves is disturbed when the angle-of-attack and free-stream Mach number vary in an investigated range. This also affects lift and drag coefficients of the wing.
Computational Study on Radiative Aerothermodynamics of a Reentry Space Vehicle
Authors: Li Qi , Zhang Sijun 
Published: October 2021

Abstract
Under hypersonic flight conditions, a vehicle travelling through the atmosphere could excite the air that flows around the body to very high temperatures as the kinetic energy of the vehicle is dissipated to the gas. Depending on the flight velocity, various chemical reactions will be produced behind a shock wave for stagnation region. These reactions greatly change the properties of air and cause considerable deviation from those of a thermally and calorically perfect gas. A vehicle flying through the higher altitude of the atmosphere at high velocities may also experience thermal non-equilibrium since the lower density reduces the collision frequency and the high velocity results in smaller transit times for the air molecules. Under such extremely thermal circumstances, the heat transfer by convection and radiation around a vehicle has been one of key issues for thermal protection system (TPS). In this paper, the computational aerothermodynamics with fully coupled radiative heat transfer is developed. To validate the proposed approach, it is employed to simulate the thermal and chemical nonequilibrium flows over Stardust. The computed results on the reentry space vehicle reveal both of convective flux and radiative flux are in good agreements with other predicted results.
Dual-Luminescence Imaging and Particle Tracking Velocimetry for Simultaneous Temperature and Velocity Field Measurements in Hydrocarbons Liquid
Authors: Hayashi Tatsunori , Farahani Hamed F. , Rangwala Ali S. , Sakaue Hirotaka 
Published: October 2021

Abstract
Arctic oil spills are particularly detrimental as they could cause extensive ice melting in addition to the environmental pollution they create. Floating oil slicks amongst ice floes absorb ambient energy and transfer that energy to the ice to aggravate melting in the thaw season. However, few studies have been undertaken to reveal how oil-ice interactions impact ice melting. This research employs a measurement technique to investigate the heat transfer pathways from oil slicks to the ice. Dual-luminescence imaging and particle imaging velocimetry (PIV) in a side cooled cavity is performed for temperature and velocity measurements of Toluene, respectively. Dual-luminescence imaging captured the spatial temperature distribution of the fuel. Consecutive imaging of the seeding particles in PIV provided the spatial velocity field of the fuel in the cavity. The results show that the convective field is directly coupled with the temperature field, i.e., the temperature difference instigates a flow in the liquid. Successful implementation of the two measuring techniques together is a step toward analyzing heat transfer pathways in a liquid fuel adjacent to an ice body, indicating the extent of melting.
Parametric Identification of Rotating Cavitation in a Three-Bladed Axial Inducer
Authors: Costanzo Antonio , Valentini Dario , Pace Giovanni , Hadavandi Ruzbeh , Torre Lucio , Pasini Angelo , d’Agostino Luca 
Published: October 2021

Abstract
The article illustrates the application of Bayesian estimation to the identification of flow instabilities, with special reference to rotating cavitation, in a three-bladed axial inducer using the unsteady pressure readings of a single transducer mounted on the casing just behind the leading edges of the impeller blades. The typical trapezoidal pressure distribution in the blade channels is parametrized and modulated in time and space for theoretically reproducing the expected pressure generated by known forms of cavitation instabilities (cavitation auto-oscillations, n-lobed rotating cavitation, higher-order surge/rotating cavitation modes).
The Fourier spectra of the theoretical pressure so obtained in the rotating frame are transformed in the stationary frame, frequency broadened to better approximate the experimental results, and parametrically fitted by maximum likelihood estimation to the measured auto-correlation spectra. Each form of instability generates a characteristic distribution of sidebands in addition to its fundamental frequency. The identification makes use of this information for effective detection and characterization of multiple simultaneous flow instabilities with intensities spanning over about 20 dB down to about 4 dB signal-to-noise ratios. The same information also allows for effectively bypassing the aliasing limitations of traditional cross-correlation methods in the discrimination of multiple-lobed azimuthal instabilities from dual-sensor measurements on the same axial station of the machine. The method returns both the estimates of the model parameters and their standard deviations, providing the information needed for the assessment of the statistical significance of the results. The proposed approach represents therefore a promising tool for experimental research on flow instabilities in high-performance turbopumps.
Causal Inference Analysis to Find Relationships Found in Boundary-Layer Transition – Part I: Theoretical
Authors: Rodriguez Arturo , Terrazas Jose , Adansi Richard , Kotteda V. M. Krushnarao , Munoz Jorge A. , Kumar Vinod 
Published: October 2021

Abstract
Understanding the transition from laminar to turbulent flow – Boundary-Layer Transition (BLT), we can design better state-of-the-art vehicles for defense and space applications, which can mitigate the limitations in current high-speed temperature conditions. BLT is a subject of fluid flow disturbances created by geometric parameters and flow conditions, such as surface roughness, increased velocity, and high-pressure fluctuations, to name a few. These disturbances lead to the development of turbulent spots and differential heating. Historically, the Reynolds number has been used to predict whether a system will develop turbulent flow. However, it has been known for decades that it is not always reliable and cannot indicate where the BLT will occur: some experiments present scenarios where the flow is laminar at a high Reynolds number and vice versa. We can predict the BLT from performing physical experiments, but they are expensive and physical configurations are limited. Despite many community efforts and successes, no general computational solution to simulate different flows and vehicle types that fully incorporate BLT exists. Many are a considerable number of parameters that affect BLT. Therefore, we use Causal Inference to predict BLT by cause-and-effect analysis on multivariate data obtained from BLT studies. Data generated using high-fidelity Computational Fluid Dynamics (CFD) with resolved Large-Eddy Simulations (LES) scales, will be analyzed for turbulence intensity by decomposing velocity in mean and fluctuations. In this paper, we will be discussing approaches on how we predict BLT scenarios using cause and effect relationships driven by causal inference analysis.
Effect of Aerodynamic Moment on High-Speed Maglev Train Under Complicated Conditions
Authors: Hao Zhanzhou , Yin Bo , Yang Guowei , Xiao Pan 
Published: October 2021

Abstract
As the next generation of high-speed rail transportation, the high-speed maglev train has a design speed of 600km/h, whose Mach number is about 0.49. The severe aerodynamic effect caused by this high speed has a substantial impact on the train’s stability and safety. In this paper, the aerodynamic moments of two three-carriage maglev trains passing by each other in open air are investigated by numerical simulation. To get transient moments acting on the train, this study adopted the sliding mesh method and the k-ε turbulent model, and a user-defined function was compiled to define the motion of maglev. The results show that the pitching moment is the most important factor for the steady of maglev trains running in the open air. The oscillation of the total aerodynamic moment mainly comes from the moment acting on the lower part. The coupling of the pitching moment acting on the upper and lower part of carriages make the peak of the total pitching moment behind the total yawing moment.
Swimming of the Trophont Zooid of Vorticella Convallaria
Authors: Kizghin Dilziba , Ryu Sangjin , Park Younggil , Jung Sunghwan 
Published: October 2021

Abstract
Vorticella convallaria is a ciliated protozoan found in freshwater habitats. In the sessile or stalked trophont form, V. convallaria is shaped somewhat like a balloon as it has a body or zooid (the head of the balloon) that is about 40 μm large with cilia around its oral part, and a stalk (the string of a balloon) anchoring the zooid to a solid surface. When a trophont zooid of V. convallaria detached from the stalk, the zooid swims around in water by creating water flow using its oral cilia. In contrast to the stalk contraction of V. convallaria that has been well studied, the swimming motility of V. convallaria is little known. In this study, we measured the swimming trajectories of the stalkless trophont zooid of V. convallaria using video microscopy and Hele-Shaw cells with a gap height of 25 μm, traced the swimming zooid using image processing, and analyzed the swimming motion in terms of swimming velocity and mean square displacement. The stalkless trophont zooid of V . convallaria was found to swim in circular patterns with intermittent ballistic motions in the confinement, and the average swimming speed ranged from 20 μm/s to 110 μm/s. Since the swimming pattern of V. convallaria appeared to be affected by the level of confinement, we will continue characterizing the ciliate’s swimming in the Hele-Shaw cell with different gap heights. Our study is expected to reveal the swimming motility of V. convallaria and to advance general understanding of swimming of microorganisms.
RANS-VOF Simulations of Fully Developed Density-Stratified Air-Water Flow in a 3D Rectangular Duct
Authors: Jana Maiti Chandrima , Ghia Urmila , Turkevich Leonid A. 
Published: October 2021

Abstract
We perform RANS-VOF simulation of turbulent, fully developed, density-stratified air-water flow in a 3D rectangular duct cross section of height twice the width. Flow through an open or partially-filled duct is characterized by the presence of an air-water interface interacting with a solid wall, forming a mixed-boundary corner. A novel feature of the mixed-boundary corner for turbulent flow is the interaction of wall turbulence with the air-water interface. In the current study, the RANS-VOF equations (for fully developed flow) are solved in a rectangular duct, using periodic inlet/outlet boundary conditions. The flow is completely specified by the (common) driving pressure gradient down the duct and by the fill factor (relative height of the heavier phase to the total height of the duct). Varying the pressure gradient and fill factor results in different flow combinations, namely, laminar air/laminar water, turbulent air/laminar water, turbulent air/turbulent water, laminar air/turbulent water. Since RANS-VOF simulations are computationally less expensive compared to LES and DNS, we systematically investigated a range of flow combinations. The Reynolds stresses are tracked near the mixed-boundary corner for the different flow combinations. The structure of the secondary vortices near the mixed-boundary corner differs from that in the corner formed by the solid vertical and horizontal duct walls.