bluuebunny/crossref_metadata_2025 huggingface dataset:
A Joint Confidence Region for an Overall Ranking of Populations
Authors: Klein Martin , Wright Tommy , Wieczorek Jerzy
Published: March 2020

National statistical agencies lack statistical methodology to express uncertainty in their released estimated overall rankings. For example, the US Census Bureau produced an ‘explicit’ ranking of the states based on observed sample estimates during 2011 of mean travel time to work. Current literature provides measures of uncertainty in estimated individual ranks, but not a direct measure of uncertainty for the estimated overall ranking. We construct and visualize a joint confidence region for the true unknown overall ranking that provides a measure of uncertainty in the estimated overall ranking.
Does educational inequality predict exercise of users' choice? Survey evidence from domiciliary care services among elderly in Oslo, Norway
Authors: Trætteberg Håkon S. , Fladmoe Audun
Published: March 2020

The traditional goal of equality in services remains at the heart of the Scandinavian welfare model; however, in recent decades, policymakers have also placed increased emphasis on user influence over services. Voice and choice are two channels to achieve this goal. The possibility to give feedback and voicing dissatisfaction to service providers (voice) is a well‐established channel of service users' influence, however it is increasingly supplemented by user choice schemes (choice), where one can choose between different public and private service providers. We use the case of domiciliary care for the elderly to examine how the traditional goal of user equality is associated with the growing emphasis on user influence through voice and choice. The analyses are based on user surveys carried out by the municipality in the city of Oslo, which is arguably the only municipality in Norway where user choice plays a significant role in elderly care. Since the municipality subsidizes the private providers, individual economic resources should have less relevance. However, voicing dissatisfaction and choosing between different providers may anticipate cognitive resources that are not equally distributed among the users. The survey data indicate that there is an association between level of education and propensity to exploit all channels of user influence. Expanding user influence by introducing user choice thus confirms the differences between highly educated and less educated.
The rice/maize pathogen Cochliobolus spp. infect and reproduce on Arabidopsis revealing differences in defensive phytohormone function between monocots and dicots
Authors: Völz Ronny , Park Ju‐Young , Kim Soonok , Park Sook‐Young , Harris William , Chung Hyunjung , Lee Yong‐Hwan
Published: March 2020

The fungal genus Cochliobolus describes necrotrophic pathogens that give rise to significant losses on rice, wheat, and maize. Revealing plant mechanisms of non‐host resistance (NHR) against Cochliobolus will help to uncover strategies that can be exploited in engineered cereals. Therefore, we developed a heterogeneous pathosystem and studied the ability of Cochliobolus to infect dicotyledons. We report here that C. miyabeanus and C. heterostrophus infect Arabidopsis accessions and produce functional conidia, thereby demonstrating the ability to accept Brassica spp. as host plants. Some ecotypes exhibited a high susceptibility, whereas others hindered the necrotrophic disease progression of the Cochliobolus strains. Natural variation in NHR among the tested Arabidopsis accessions can advance the identification of genetic loci that prime the plant’s defence repertoire. We found that applied phytotoxin‐containing conidial fluid extracts of C. miyabeanus caused necrotic lesions on rice leaves but provoked only minor irritations on Arabidopsis. This result implies that C. miyabeanus phytotoxins are insufficiently adapted to promote dicot colonization, which corresponds to a retarded infection progression. Previous studies on rice demonstrated that ethylene (ET) promotes C. miyabeanus infection, whereas salicylic acid (SA) and jasmonic acid (JA) exert a minor function. However, in Arabidopsis, we revealed that the genetic disruption of the ET and JA signalling pathways compromises basal resistance against Cochliobolus, whereas SA biosynthesis mutants showed a reduced susceptibility. Our results refer to the synergistic action of ET/JA and indicate distinct defence systems between Arabidopsis and rice to confine Cochliobolus propagation. Moreover, this heterogeneous pathosystem may help to reveal mechanisms of NHR and associated defensive genes against Cochliobolus infection.
SNPeffect: identifying functional roles of SNPs using metabolic networks
Authors: Sarkar Debolina , Maranas Costas D.
Published: March 2020

Genetic sources of phenotypic variation have been a focus of plant studies aimed at improving agricultural yield and understanding adaptive processes. Genome‐wide association studies identify the genetic background behind a trait by examining associations between phenotypes and single‐nucleotide polymorphisms (SNPs). Although such studies are common, biological interpretation of the results remains a challenge; especially due to the confounding nature of population structure and the systematic biases thus introduced. Here, we propose a complementary analysis (SNPeffect) that offers putative genotype‐to‐phenotype mechanistic interpretations by integrating biochemical knowledge encoded in metabolic models. SNPeffect is used to explain differential growth rate and metabolite accumulation in A. thaliana and P. trichocarpa accessions as the outcome of SNPs in enzyme‐coding genes. To this end, we also constructed a genome‐scale metabolic model for Populus trichocarpa, the first for a perennial woody tree. As expected, our results indicate that growth is a complex polygenic trait governed by carbon and energy partitioning. The predicted set of functional SNPs in both species are associated with experimentally characterized growth‐determining genes and also suggest putative ones. Functional SNPs were found in pathways such as amino acid metabolism, nucleotide biosynthesis, and cellulose and lignin biosynthesis, in line with breeding strategies that target pathways governing carbon and energy partition.
The Influence of Emotional State on Mobile Phone Addiction Tendency in College Students: The Mediation Role of Regulatory Emotion Self-efficacy
Authors: Fu Guifang , Liu Jingwen , Liu Haichun
Published: March 2020

In order to explore the situation of college students’ emotional state, regulatory emotion self-efficacy and mobile phone addiction tendency as well as their relationships, a total of 350 college students were assessed with Mobile Phone Addiction Tendency Scale (MPATS), Positive Affect and Negative Affect Scale (PANAS) and the Scale of Regulatory Emotional Self-efficacy (SRESE). The result showed that: (1) 40.86% of college students had the tendency of cell phone addiction, which was serious; 72.0% of college students were in a positive emotional state, 22% were in a negative emotional state; college students' regulatory emotion self-efficacy was in the middle level; (2) there was no gender, grade, major type, household registration type (rural and urban) and whether only child difference in mobile phone addiction tendency; (3) the positive emotions of college students were negatively correlated with the tendency of mobile phone addiction, while the negative emotions were positively correlated with the tendency of mobile phone addiction, and the positive emotion was positively correlated with regulatory emotional self-efficacy；(4) the regulatory emotion self-efficacy had a partial mediating effect between the positive emotions and mobile phone addiction tendency and had no mediating effect between the negative emotions and mobile phone addiction tendency.
A Nonlinear Mechanics Model of Zigzag Cellular Substrates for Stretchable Electronics
Authors: Zhao Shiwei , Zhu Feng , Yan Zhengang , Li Daochun , Xiang Jinwu , Huang Yonggang , Luan Haiwen
Published: March 2020

The use of cellular elastomer substrates not only reduces its restriction on natural diffusion or convection of biofluids in the realm of stretchable electronics but also enhances the stretchability of the electronic systems. An analytical model of “zigzag” cellular substrates under finite deformation is established and validated in this paper. The deformed shape, nonlinear stress–strain curve, and Poisson’s ratio–strain curve of the cellular elastomer substrate calculated using the reported analytical model agree well with those from finite element analysis (FEA). Results show that lower restriction on the natural motion of human skin could be achieved by the proposed zigzag cellular substrates compared with the previously reported hexagonal cellular substrates, manifesting another leap toward mechanically “invisible” wearable, stretchable electronic systems.
Parallelized Multiscale Off-Road Vehicle Mobility Simulation Algorithm and Full-Scale Vehicle Validation
Authors: Yamashita Hiroki , Chen Guanchu , Ruan Yeefeng , Jayakumar Paramsothy , Sugiyama Hiroyuki
Published: March 2020

In this work, a scalable parallel computing scheme for the hierarchical multiscale off-road vehicle mobility simulation capability is developed with the hybrid message passing interface (MPI)/OpenMP framework, and it is validated against full-scale vehicle test data. While the hierarchical multiscale modeling approach has been introduced to high-fidelity off-road mobility simulations to eliminate limitations of existing single-scale deformable terrain models, computational complexities associated with the large dimensionality of multibody vehicle equations, involving nonlinear finite element tires and multiscale terrain models, need to be addressed for use in full-scale vehicle mobility predictions. To this end, a co-simulation framework for the multiscale off-road vehicle mobility model is proposed by exploiting the moving soil patch technique. This allows for systematically extracting four moving soil patches for four tires in a vehicle model from the deformable terrain domain, and time integrations of the four tire–soil subsystems are performed concurrently to enable computational speedup. Furthermore, an automated updating scheme for multiscale moving soil patches for a full vehicle model is developed, considering the multipass effect in various vehicle maneuvering scenarios. To demonstrate the off-road mobility prediction capability using the proposed parallelized multiscale vehicle–terrain interaction simulation algorithm, full-scale vehicle validation is presented for the vehicle drawbar pull as well as variable grade hill climb tests on soft soil.
Parametric Estimation of Volterra Kernel for the Dynamic Response of an Offshore Structure Using Laguerre Polynomials
Authors: Son Jae-Hyeon , Kim Yooil
Published: March 2020

The behavior of a nonlinear dynamic system under arbitrary excitation can be represented by the Volterra series if the Volterra kernels of different orders are known. This study presents a methodology for a direct estimation of the Volterra kernel coefficients up to the second-order using prepared data obtained by running a time-domain analysis of the system of interest. To avoid potential problems during kernel estimation, the Volterra kernel is expanded into a polynomial series using the Laguerre polynomials, and the coefficients of the Laguerre polynomials are then estimated using a least-square method. A nonlinear oscillator with a quadratic stiffness term is introduced, and the methodology is applied to check the applicability and accuracy. The methodology is applied to a more realistic engineering problem of a simplified riser under irregular wave excitation.
Fatigue Life Estimation for HFMI-Treated Weldments Considering Weld Toe Magnification Factors
Authors: Kim Dong-Yub , Kim Myung-Hyun
Published: March 2020

High-frequency mechanical impact (HFMI) post-treatment is a proven method to improve the fatigue life of welded structures. The positive effects of HFMI treatment are influenced by the weld toe geometries and residual stresses. This study investigates the effect of geometric and mechanical improvements by HFMI treatment on fatigue strength with explicit consideration of the weld toe magnification factor. General fatigue life estimation method is based on experiment data, and residual stress may be considered in addition. In terms of HFMI-treated structures, geometric improvement also affects the fatigue life. Thus, a more efficient method is suggested by considering the weld toe magnification factor to assess the effects of HFMI treatment. First, the weld toe magnification factor in HFMI-treated conditions is calculated to consider the geometrical effect of HFMI treatment at the weld toe region. Second, a stress ratio model is introduced to consider the compressive residual stress by HFMI treatment based on the Paris equation. The results were validated by comparing them with the estimated fatigue life from previous studies on HFMI-treated welded specimens.
Transient Fuel Spray Structure for Simulated Injection Strategies in Direct Injection, Spark Ignition Engines
Authors: Hutchison P. A. , Wicker R. B.
Published: March 2020

For two production DISI fuel injectors, flow visualization and particle image velocimetry (PIV) were utilized to illustrate the effect of fuel rail pressure and in-cylinder density (using in-cylinder pressure) on instantaneous fuel spray structure. Studies were performed within a non-motored research cylinder for two fuel rail pressures (3 MPa and 5 MPa) and two in-cylinder pressures (2 atm and 6 atm). Instantaneous flow visualization demonstrated the effects of changes in fuel rail pressure and in-cylinder density on transient spray structure. Increased fuel rail pressure resulted in increased narrowing of the spray cross-section and increased spray penetration distance. Increased in-cylinder density produced sprays with increased narrowing of the spray cross-section and shorter penetration distances. Spray velocities were shown to increase with increased fuel rail pressure and decrease with increased in-cylinder density.
A Study on the Breakdown Voltage Analysis of the Spark Plug Gap for Extraction of the Information About the Pressure in Cylinder
Authors: Park Jaekeun , Chae Jaeou
Published: March 2020

In-cylinder pressure of an internal combustion engine is considered to be a major source of information about combustion process. It is a generally accepted method to obtain an in-cylinder pressure signal using a pressure sensor (transducer). A different method of approach is presented in this study. The information about the in-cylinder pressure can be obtained by measuring breakdown voltage across the spark-plug gap.

The density of gas inside the combustion chamber effect on the breakdown voltage of the spark plug, which is derived by the application of a high bias voltage (30kV) to the sparkplug gap continuously. The correlation between maximum breakdown voltage position and peak pressure position is established by this principle. So it is possible to detect the peak pressure position by measuring the breakdown voltage of the spark plug. The analyzing method of the breakdown voltage signal is also presented.
Applying the Representative Interactive Flamelet Model to Evaluate the Potential Effect of Wall Heat Transfer on Soot Emissions in a Small-Bore DI Diesel Engine
Authors: Hergart Carl , Peters Norbert
Published: March 2020

Due to the wide spectrum of turbulent and chemical length- and time scales occurring in a HSDI diesel engine, capturing the correct physics and chemistry underlying combustion poses a tremendous modeling challenge. The processes related to the two-phase flow in a DI diesel engine add even more complexity to the total modeling effort. The Representative Interactive Flamelet (RIF) model has gained widespread attention owing to its ability of correctly describing ignition, combustion and pollutant formation phenomena. This is achieved by incorporating very detailed chemistry for the gas phase as well as the soot particle growth and oxidation, without imposing any significant computational penalty. The model, which is based on the laminar flamelet concept, treats a turbulent flame as an ensemble of thin, locally one-dimensional flame structures, whose chemistry is fast. A potential explanation for the significant underprediction of part load soot observed in previous studies applying the model is the neglect of wall heat losses in the flamelet chemistry model. By introducing an additional source term in the flamelet temperature equation, directly coupled to the wall heat transfer predicted by the CFD-code, flamelets exposed to walls are assigned heat losses of various magnitudes. Results using the model in three-dimensional simulations of the combustion process in a small-bore direct injection diesel engine indicate that the experimentally observed emissions of soot may have their origin in flame quenching at the relatively cold combustion chamber walls.
Theoretical Investigation on the Influence of Physical Parameters on Soot and NOx Engine Emissions
Authors: de Risi Arturo , Donateo Teresa , Laforgia Domenico
Published: March 2020

CFD simulations need a certain number of parameters to calibrate both empirical and analytical models. The present investigation aims at identifying the effects of these parameters on the numerical prediction of a modified version of Kiva 3V code, which includes the use of the RNG k-ε model for turbulence, the gas/wall convective heat transfer model proposed by Han, Kelvin-Helmholtz Rayleigh-Taylor spray injection and breakup models. Ignition delay was modeled with the Shell model, whereas the laminar-turbulent characteristic time model was used for combustion. Soot formation and oxidation were calculated using Hiroyasu and Nagle and Strickland-Constable models, respectively. NOx was predicted by using the extended Zel’dovich mechanism.

This study was carried out for a common-rail direct injection, small-bore Diesel engine, including the investigation of both numerical and physical parameters. Numerical parameters are intended to be variables related to breakup, turbulence, and combustion models that are adjusted according to grid resolution, engine and injection system geometry, and operating conditions. In particular, the effect of laminar and turbulent time scales, characteristic breakup length and time scales, initial turbulence kinetic energy density, initial swirl velocity profile, on engine emissions was analyzed.

The investigated physical parameters were initial swirl ratio, air water content, Schmidt number for mass diffusion.

All simulations were performed by changing one of the above parameters at each run and keeping approximately the same pressure and heat release rate curves. Results show that similar pressure vs. crank angle curves can be obtained with different values of these parameters but they lead to very different values of predicted emissions levels. In particular, changes of laminar and turbulent characteristic time resulted in a strong influence on NOx emissions but their effects on soot levels were minor. Mass diffusion characteristics (e.g. Schmidt number) were found to strongly affect both soot and NOx emissions. Spray parameters were found mainly to affect soot formation. Furthermore, NOx and soot emissions showed a dependence on swirl ratio and velocity profile.
The Effect of Subgrid Modeling on the In-Cylinder Unsteady Mixing Process in a Direct Injection Engine
Authors: Sone Kazuo , Menon Suresh
Published: March 2020

The process of fuel-air mixing in the Direct Injection Spark Ignition (DISI) engine is highly unsteady and three-dimensional with wide cycle-to-cycle variations involving vaporization of droplets and its interaction with large-scale turbulent flow field. Although the majority of the past numerical studies of mixing in an Internal Combustion (IC) engines have employed Reynolds-Averaged Navier-Stokes (RANS) equations with empirical turbulence model, here we have implemented a Large-Eddy Simulations (LES) with the Linear-Eddy Model (LEM) for subgrid scalar mixing into a commercial IC engine simulation code (KIVA-3V). This study shows that when time-accurate effects are included significantly different results are obtained. These differences between the original KTVA-3V and the new KIVALES in predicting the in-cylinder turbulent fuel-air mixing are discussed. LES shows highly unsteady, anisotropic in-cylinder fuel-air mixing process compared to the original KIVA-3V. The implications for combustion is also discussed.
Laser Based Measurements of Instantaneous Characteristics in High Pressure Fuel Injection and Swirl Spray
Authors: Ismailov Murad M.
Published: March 2020

Transient dynamics of two injection flows, upstream and downstream from a swirl injector, are investigated. Capillary n-heptane pipe flow is measured using laser Doppler anemometer to obtain the instantaneous time series of centerline velocity and to reconstruct a series of instantaneous and integrated flow rates and pressure gradients. A collimated laser sheet and a high-speed video camera visualize injected spray flow. Finally, the phase Doppler anemometer measurements are introduced to analyze instantaneous patterns of droplets, velocity-size and number density in the fuel spray.

All measurements are employed at similar temporal resolution close to 30 μs. Results indicate that both flows are strongly time-dependent and well correlated in time-phases. Initial transitions are completed by 100 μs. Opening or closing of the injector valve affects both flows as strong delta oscillation causes spray penetration dynamics and a post injection effect.

A combination of non-intrusive laser-based techniques allows indication of the basic injection and spraying characteristics needed to optimize high-pressure fuel injectors and the late injection combustion mode.
A Study on Cylinder Bore Deformation of a Diesel Engine With Dry Liner Structure
Authors: Yamamoto Shigeto , Sakita Hiroshi , Takiguchi Masaaki , Sasaki Shinichi
Published: March 2020

The deformation of the cylinder liner of a diesel engine in actual operation have been measured by the means of a rotary piston, and the deformation has been compared with those measured statically at room temperature. As a result, it is found that the deformation of the liner in engine operation is hardly affected by the deformation at room temperature, but it follows the deformation of the cylinder block where the liner is inserted. It is also found as follows: The deformation of the liner upper portion varies according to the head bolts and the engine load, while the effect of the cylinder pressure is insignificant. The deformation at the middle of the liner changes mainly by the thermal expansion in the thrust direction, while the deformation at the lower portion is not affected by the engine speed or the load.
Piston Slap Induced Noise Simulation Considering Elasto-Hydrodynamic Contact Conditions
Authors: Priebsch Hans H. , Herbst Hubert M. , Offner Günter
Published: March 2020

Main aims in the development process for the cylinder assembly of internal combustion engines are the reduction of friction and wear due to the contact between piston and liner as well as the minimization of piston slap induced noise.

In this paper, the authors extend their methodology for the simulation of structural dynamics in the area of piston and liner with the aim of predicting structure borne noise excited by the piston slap phenomenon. The simulation model uses linear, flexible bodies subjected to highly non-linear joint forces, as occurring in the piston-to-liner contact. Both, the theoretical background and the advantages of the coupled simulation procedure for such complex systems are discussed. The models are validated by comparison of measured and computed values of piston movements and modal structure behavior.

The result examples focus on the effects of piston secondary movement, the resulting impact on the lubricated liner and the analysis of vibration transfer behavior in the block structure. It is shown how noise excitation and structure borne vibration transfer paths can be analyzed in order to assess engine design. Result plots show typical results on the surface of a 4 Cylinder Diesel engine and the contribution of piston slap induced noise.
Analysis of Oil Film Thickness on a Piston Ring of Diesel Engine: Effect of Oil Film Temperature
Authors: Harigaya Yasuo , Suzuki Michiyoshi , Takiguchi Masaaki
Published: March 2020

This paper describes that an analysis of oil film thickness on a piston ring of diesel engine. The oil film thickness has been performed by using Reynolds equation and unsteady, two-dimensional (2-D) energy equation with a heat generated from viscous dissipation. The temperature distribution in the oil film is calculated by using the energy equation and the mean oil film temperature is computed. Then the viscosity of oil film is estimated by using the mean oil film temperature. The effect of oil film temperature on the oil film thickness of a piston ring was examined. This model has been verified with published experimental results. Moreover, the heat flow at ring and liner surfaces was examined. As a result, the oil film thickness could be calculated by using the viscosity estimated from the mean oil film temperature and the calculated value is agreement with the measured values.
Study on Wear of Piston Rings in Diesel Engines With Exhaust Gas Recirculation
Authors: Sato Tokuro , Saito Hideki , Korematsu Koji , Tanaka Junya
Published: March 2020

The wear of piston rings in the diesel engines with EGR system is studied experimentally. In order to clarify the effect of PM on the wear, the wear of the piston rings in the test engine is measured,

(1) when the non-soluble in the lubricating oil is removed by the oil filters,

(2) when PM in the re-circulating gas is removed by the DPF,

(3) when the carbon black is added in the lubricating oil.

The experimental results are discussed with the measured time history of kinematic viscosity, total base number, total acid number, ZDTP survival rate, and carbon residual content and its particle size in the engine oil.
Model Based Analysis of Turbocharger Power Assist Systems for Reduced Turbo-Lag
Authors: Upadhyay Devesh , Rizzoni Giorgio
Published: March 2020

As Diesel engines continue to find favor amongst automakers, two aspects common to all Diesel engines remain at the center of all research activity. While reduction of Diesel emissions, such as NOx, Particulate Matter (PM) and smoke continues to be the more serious challenge, the issue of acceleration performance remains to be fully resolved. If the diesel engine is to find acceptance amongst the US passenger car users, it must perform at the level of the Spark Ignition (SI) engine in terms of brisk acceleration response. It is imperative that the Diesel engine shakes off the image of “the sluggish machine”. Technically this amounts to either reducing turbo-Lag to an indiscernible level or eliminating it completely. Since turbo-Lag is linked directly to turbocharger (T/C) inertial dynamics, several techniques have been tried over the years to reduce this effect. In this paper we present a model-based evaluation of four techniques, namely:

1. Variable Geometry turbocharging (VGT).

2. Electrical Assist of turbochargers.

3. Hyperbar (HB) turbocharging.

4. External Air assist.

Variable Geometry turbocharging has already found wide application and is now considered an essential feature on all modern Diesel engines. Electrical assist of turbochargers for automotive application is still in its developmental stages but holds great promise. Hyperbar T/C and external air assist are unconventional techniques but offer possibilities of improvement for the T/C.
Dynamic Performance of Conventional and Electrically Activated Engine Thermostats
Authors: Gunter L. Alan , Nalim M. Razi
Published: March 2020

This study concerns the dynamic performance of passive and active wax-actuator driven thermostats. The study is extended to wax actuator driven thermostats that have been fitted with a heating device, such that the thermostat can be actuated electrically. The thermostat valve type chosen for this study is a balanced, sleeve-type thermostat typically used in large over-the-road and industrial diesel engines. The valve operates like a spool valve to direct the flow of the engine coolant to the bypass, the heat exchanger, or partially to each. Since conventional thermostats are passive devices they lag in response to dynamic engine conditions, and under certain circumstances overheating can occur as a result of the device’s inability to respond quickly. Also, conventional thermostats are designed to protect an engine against overheating year round. Therefore, a thermostat designed to protect against overheating in the summer will often result in an overcooling condition in the winter. One possible solution to the problem is to control the thermostat electrically through the electronic engine control system, or other system, making the thermostat an active control device instead of a passive one. In this study, a mathematical model is developed to determine wax temperature, and thereby predict the thermostat operation and response. The wax temperature depends on the heat transfer from the engine coolant through the brass cup that encapsulates the wax, as well as heat transfer from the heater. The simulations are compared with measurements of temperature, thermostat position and flow at several locations around the thermostat in an experimental set-up. The outcome is used to analyze the accuracy of the methods used in the thermodynamic calculations.
Bearing Characteristic Parameters to Estimate the Optimum Counterweight Mass of a 6-Cylinder In-Line Engine
Authors: Stanley Richard E. , Taraza Dinu
Published: March 2020

Two dimensionless relationships that estimate the maximum and average bearing load of a 6-cylinder 4-stroke in-line engine have been found. These relationships may assist the design engineer in choosing a desired counterweight mass. It has been demonstrated that: 1) the average bearing load increases with engine speed and 2) the maximum bearing load initially decreases with engine speed, reaches a minimum, then increases quickly with engine speed. This minimum refers to a critical speed at which the contribution of the inertia force overcomes the contribution of the maximum pressure force to the maximum bearing load. The critical speed increases with an increase of counterweight mass and is a function of maximum cylinder pressure and the operating parameters of the engine.
Air Bearing Models and Solutions for Sub-5 nm Spacings
Authors: Bogy D. B. , Wu Lin
Published: March 2020

When the flying height is below 5 nm, some physical phenomena that can be ignored for higher flying sliders need to be included in the modeling equations. Another challenging issue is the unavoidable asperity contact problem. It is known that zero spacing at asperities may cause some of the existing modified Reynolds equations to predict unphysical unbounded contact pressure singularities. In this paper we first review the source of these pressure singularities, showing which models have this problem and which do not. We also review here a new derivation of a compressible lubrication equation by using a different slip velocity boundary condition, in which additional slippage at the gas-solid interface due to pressure gradient is introduced. The new equation is free of any contact singularity [1]. Next we review our recent work on the non-negligible effect of the intermolecular forces on the slider’s flying attitude when the spacing is below 5 nm [2]. The additional force is attractive until the spacing is below about 0.1 nm for example and then it is repulsive. Finally we show the effect of these new force contributions on the flying attitude of a low flying slider.
Thermal Behavior of Magnetoresistive Heads: An Analysis of the Thermal Asperity Problem
Authors: Kennedy Francis E. , Chen Li , Bogy David B.
Published: March 2020

It is well known that the resistance of a magnetoresistive (MR) or giant magnetoresistive (GMR) head, and therefore its output, varies as its temperature changes. This causes uncertainty in the interpretation of magnetic output, and this uncertainty becomes more important when an asperity or particle passes by or comes into contact with the slider, causing a voltage transient during read back. The temperature variation during non-contact is caused by changes in the cooling of the air bearing surface as the flying height changes. When contact occurs an even more significant temperature spike, called a ‘thermal asperity’ (or TA), is caused by frictional heating at the contact interface. These temperature fluctuations are analyzed in this paper.

Results show that the temperature of the MR read coil is influenced by bias current in read coil, slider materials and flying height (which is sensitive to surface topography). The temperature variation without contact causes MR output signal variations which can be used to characterize surface topography. The flash temperature rise that occurs with asperity contact can be as much as 150 degrees (C) or more at the contact interface, but it lasts less than a microsecond. The magnitude of the TA temperature spike is affected by contact force, sliding velocity, and geometry and properties of slider and disk materials, including surface films.
Spectral integration of infrasound at threshold
Authors: Friedrich Björn , Joost Holger , Fedtke Thomas , Verhey Jesko L.
Published: March 2020

The present study investigated the effect of the number of spectral components on the threshold in quiet of infrasound stimuli. Stimuli with one, two, or three sinusoidal components were presented monaurally to the ear with a low-distortion infrasound reproduction system. All components of the complex tones had the same level relative to their respective pure-tone threshold. The data are consistent with the assumption of a (perceptually weighted) intensity integration at threshold: The level at threshold for each component is 3 dB lower when two components were presented simultaneously. Thresholds decrease further, when a three-tone complex is used.
The mechanism of Hsp90-induced oligomerizaton of Tau
Authors: Weickert S. , Wawrzyniuk M. , John L. H. , Rüdiger S. G. D. , Drescher M.
Published: March 2020

The chaperone Hsp90 remodels the structural ensemble of Tau, resulting in the formation of potentially neurotoxic oligomers.
Hyena paleogenomes reveal a complex evolutionary history of cross-continental gene flow between spotted and cave hyena
Authors: Westbury Michael V. , Hartmann Stefanie , Barlow Axel , Preick Michaela , Ridush Bogdan , Nagel Doris , Rathgeber Thomas , Ziegler Reinhard , Baryshnikov Gennady , Sheng Guilian , Ludwig Arne , Wiesel Ingrid , Dalen Love , Bibi Faysal , Werdelin Lars , Heller Rasmus , Hofreiter Michael
Published: March 2020

Westbury
et al.
reveal the genome-level evolutionary relationships between extinct cave and extant spotted hyena.
Soft, wireless periocular wearable electronics for real-time detection of eye vergence in a virtual reality toward mobile eye therapies
Authors: Mishra Saswat , Kim Yun-Soung , Intarasirisawat Jittrapol , Kwon Young-Tae , Lee Yongkuk , Mahmood Musa , Lim Hyo-Ryoung , Herbert Robert , Yu Ki Jun , Ang Chee Siang , Yeo Woon-Hong
Published: March 2020

A device combining soft, wireless wearable electronics with virtual reality offers portable therapeutics for eye disorders.
Rebound of self-lubricating compound drops
Authors: Blanken Nathan , Saleem Muhammad Saeed , Antonini Carlo , Thoraval Marie-Jean
Published: March 2020

An oil shell encapsulating a water drop promotes rebound after impact on a solid surface, irrespective of substrate wettability.
A reconstituted mammalian APC-kinesin complex selectively transports defined packages of axonal mRNAs
Authors: Baumann Sebastian , Komissarov Artem , Gili Maria , Ruprecht Verena , Wieser Stefan , Maurer Sebastian P.
Published: March 2020

In vitro reconstitutions reveal the essential components of a mammalian, cytoplasmic mRNA transport system and their functions.
Combining scaling relationships overcomes rate versus overpotential trade-offs in O
2
molecular electrocatalysis
Authors: Martin Daniel J. , Mercado Brandon Q. , Mayer James M.
Published: March 2020

Combining two scaling relationships shows how to improve advanced electrochemical energy conversion catalysis.
Cytidine deaminase 2 is required for
VLRB
antibody gene assembly in lampreys
Authors: Morimoto Ryo , O’Meara Connor P. , Holland Stephen J. , Trancoso Inês , Souissi Ahmed , Schorpp Michael , Vassaux Danièle , Iwanami Norimasa , Giorgetti Orlando B. , Evanno Guillaume , Boehm Thomas
Published: March 2020

Functional assembly of lamprey antibody genes depends on
CDA2
, a gene related to mammalian activation-induced cytidine deaminase, AID.
Significant Efficacy of a Single Low Dose of Primaquine Compared to Stand-Alone Artemisinin Combination Therapy in Reducing Gametocyte Carriage in Cambodian Patients with Uncomplicated Multidrug-Resistant Plasmodium falciparum Malaria
Authors: Vantaux Amélie , Kim Saorin , Piv Eakpor , Chy Sophy , Berne Laura , Khim Nimol , Lek Dysoley , Siv Sovannaroth , Mukaka Mavuto , Taylor Walter R. , Ménard Didier
Published: March 2020

Since 2012, a single low dose of primaquine (SLDPQ; 0.25 mg/kg of body weight) with artemisinin-based combination therapies has been recommended as the first-line treatment of acute uncomplicated
Plasmodium falciparum
malaria to interrupt its transmission, especially in low-transmission settings of multidrug resistance, including artemisinin resistance. Policy makers in Cambodia have been reluctant to implement this recommendation due to primaquine safety concerns and a lack of data on its efficacy.
A Novel Growth-Based Selection Strategy Identifies New Constitutively Active Variants of the Major Virulence Regulator PrfA in Listeria monocytogenes
Authors: Hansen Sabine , Hall Michael , Grundström Christin , Brännström Kristoffer , Sauer-Eriksson A. Elisabeth , Johansson Jörgen
Published: March 2020

The Gram-positive bacterium
Listeria monocytogenes
is a human pathogen affecting mainly the elderly, immunocompromised people, and pregnant women. It can lead to meningoencephalitis, septicemia, and abortion. The major virulence regulator in
L. monocytogenes
is the PrfA protein, a transcriptional activator. Using a growth-based selection strategy, we identified mutations in the PrfA protein leading to constitutively active virulence factor expression. We provide structural evidence for the existence of an intermediately activated PrfA state, which gives new insights into PrfA protein activation.
Comparison of the management recommendations of the Kaiser Permanente neonatal early-onset sepsis risk calculator (SRC) with NICE guideline CG149 in infants ≥34 weeks’ gestation who developed early-onset sepsis
Authors: Morris Rachel , Jones Steve , Banerjee Sujoy , Collinson Andrew , Hagan Hannah , Walsh Hannah , Thornton Graham , Barnard Ian , Warren Chris , Reid Jennifer , Busfield Alison , Matthes Jean
Published: March 2020

Objective

To compare the management recommendations of the Kaiser Permanente neonatal early-onset sepsis risk calculator (SRC) with National Institute for Health and Care Excellence (NICE) guideline CG149 in infants ≥34 weeks’ gestation who developed early-onset sepsis (EOS).

Design

Retrospective multicentre study.

Setting

Five maternity services in South West of England and Wales.

Patients

70 infants with EOS (<72 hours) confirmed on blood or cerebrospinal fluid culture.

Methods

Retrospective virtual application of NICE and SRC through review of maternal and neonatal notes.

Main outcome measure

The number of infants recommended antibiotics by 4 hours of birth.

Results

The incidence of EOS ≥34 weeks was 0.5/1000 live births. Within 4 hours of birth, antibiotics were recommended for 39 infants (55.7%) with NICE, compared with 27 (38.6%) with SRC. The 12 infants advised early treatment by NICE but not SRC remained well, only one showing transient mild symptoms after 4 hours. Another four babies received antibiotics by 4 hours outside NICE and SRC guidance. The remaining 27 infants (38.6%) received antibiotics when symptomatic after 4 hours. Only one infant who was unwell from birth, died. Eighty-one per cent of all EOS infants were treated for clinical reasons rather than for risk factors alone.

Conclusion

While both tools were poor in identifying EOS within 4 hours, NICE was superior to SRC in identifying asymptomatic cases. Currently, four out of five EOS have symptoms at first identification, the majority of whom present within 24 hours of birth. Antibiotic stewardship programmes using SRC should include enhanced observation for infants currently treated within NICE guidance.
Examining which clinicians provide admission hospital care in a high mortality setting and their adherence to guidelines: an observational study in 13 hospitals
Authors: Ogero Morris , Akech Samuel , Malla Lucas , Agweyu Ambrose , Irimu Grace , English Mike
Published: March 2020

Background

We explored who actually provides most admission care in hospitals offering supervised experiential training to graduating clinicians in a high mortality setting where practices deviate from guideline recommendations.

Methods

We used a large observational data set from 13 Kenyan county hospitals from November 2015 through November 2018 where patients were linked to admitting clinicians. We explored guideline adherence after creating a cumulative correctness of Paediatric Admission Quality of Care (cPAQC) score on a 5-point scale (0–4) in which points represent correct, sequential progress in providing care perfectly adherent to guidelines comprising admission assessment, diagnosis and treatment. At the point where guideline adherence declined the most we dichotomised the cPAQC score and used multilevel logistic regression models to explore whether clinician and patient-level factors influence adherence.

Results

There were 1489 clinicians who could be linked to 53 003 patients over a period of 3 years. Patients were rarely admitted by fully qualified clinicians and predominantly by preregistration medical officer interns (MOI, 46%) and diploma level clinical officer interns (COI, 41%) with a median of 28 MOI (range 11–68) and 52 COI (range 5–160) offering care per study hospital. The cPAQC scores suggest that perfect guideline adherence is found in ≤12% of children with malaria, pneumonia or diarrhoea with dehydration. MOIs were more adherent to guidelines than COI (adjusted OR 1.19 (95% CI 1.07 to 1.34)) but multimorbidity was significantly associated with lower guideline adherence.

Conclusion

Over 85% of admissions to hospitals in high mortality settings that offer experiential training in Kenya are conducted by preregistration clinicians. Clinical assessment is good but classifying severity of illness in accordance with guideline recommendations is a challenge. Adherence by MOI with 6 years’ training is better than COI with 3 years’ training, performance does not seem to improve during their 3 months of paediatric rotations.
Perinatal stabilisation of infants born with congenital diaphragmatic hernia: a review of current concepts
Authors: Horn-Oudshoorn Emily J J , Knol Ronny , Te Pas Arjan B , Hooper Stuart B , Cochius-den Otter Suzan C M , Wijnen René M H , Schaible Thomas , Reiss Irwin K M , DeKoninck Philip L J
Published: March 2020

Congenital diaphragmatic hernia (CDH) is associated with high mortality rates and significant pulmonary morbidity, mainly due to disrupted lung development related to herniation of abdominal organs into the chest. Pulmonary hypertension is a major contributor to both mortality and morbidity, however, treatment modalities are limited. Novel prenatal and postnatal interventions, such as fetal surgery and medical treatments, are currently under investigation. Until now, the perinatal stabilisation period immediately after birth has been relatively overlooked, although optimising support in these early stages may be vital in improving outcomes. Moreover, physiological parameters obtained from the perinatal stabilisation period could serve as early predictors of adverse outcomes, thereby facilitating both prevention and early treatment of these conditions. In this review, we focus on the perinatal stabilisation period by discussing the current delivery room guidelines in infants born with CDH, the physiological changes occurring during the fetal-to-neonatal transition in CDH, novel delivery room strategies and early predictors of adverse outcomes. The combination of improvements in the perinatal stabilisation period and early prediction of adverse outcomes may mitigate the need for specific postnatal management strategies.
Carcinoma of the gallbladder presenting as haemorrhagic cholecystitis
Authors: Gomes Ana Freire , Fernandes Sara , Martins Joaquim , Coutinho João
Published: March 2020

Gallbladder carcinoma has several atypical presentations, but one of the rarest is intraluminal haemorrhage, which occurs in 1% of patients. We report a case of gallbladder cancer diagnosed by an emergency cholecystectomy, performed for acute cholecystitis caused by a hemocholecyst.
Real-world management of treatment-naïve diabetic macular oedema: 2-year visual outcome focusing on the starting year of intervention from STREAT-DMO study
Authors: Shimura Masahiko , Kitano Shigehiko , Muramatsu Daisuke , Fukushima Harumi , Takamura Yoshihiro , Matsumoto Makiko , Kokado Masahide , Kogo Jiro , Sasaki Mariko , Morizane Yuki , Utsumi Takuya , Koto Takashi , Sonoda Shozo , Hirano Takao , Ishikawa Hiroto , Mitamura Yoshinori , Okamoto Fumiki , Kinoshita Takamasa , Kimura Kazuhiro , Sugimoto Masahiko , Yamashiro Kenji , Suzuki Yukihiko , Hikichi Taiichi , Washio Noriaki , Sato Tomohito , Ohkoshi Kishiko , Tsujinaka Hiroki , Kusuhara Sentaro , Kondo Mineo , Takagi Hitoshi , Murata Toshinori , Sakamoto Taiji
Published: March 2020

Background/aims

To investigate the yearly change of real-world outcomes for best corrected visual acuity (BCVA) after 2-year clinical intervention for treatment-naïve diabetic macular oedema (DMO).

Methods

Retrospective analysis of aggregated, longitudinal medical records obtained from 27 retina specialised institutions in Japan from Survey of Treatment for DMO database. A total of 2049 treatment-naïve centre involving DMO eyes of which the initial intervention started between 2010 and 2015, and had been followed for 2 years, were eligible. As interventions, antivascular endothelial growth factor (VEGF) agents, local corticosteroids, macular photocoagulation and vitrectomy were defined. In each eye, baseline and final BCVA, the number of each intervention for 2 years was extracted. Each eye was classified by starting year of interventional treatment.

Results

Although baseline BCVA did not change by year, 2-year improvement of BCVA had been increased, and reached to +6.5 letters in the latest term. There is little difference among starting year about proportions of eyes which BCVA gained >15 letters, in contrast to those which lost >15 letters were decreased by year. The proportion of eyes receiving anti-VEGF therapy was dramatically increased, while those receiving the other therapies were gradually decreased. The proportion of eyes which maintained socially good vision of BCVA>20/40 has been increased and reached to 59.0% in the latest term.

Conclusion

For recent years, treatment patterns for DMO have been gradually but certainly changed; as a result, better visual gain, suppression of worsened eyes and better final BCVA have been obtained. Anti-VEGF therapy has become the first-line therapy and its injection frequency has been increasing.