bluuebunny/crossref_metadata_2025 huggingface dataset:
The genetic variance but not the genetic covariance of life‐history traits changes towards the north in a time‐constrained insect
Authors: Sniegula Szymon , Golab Maria J. , Drobniak Szymon M. , Johansson Frank
Published: March 2018

Seasonal time constraints are usually stronger at higher than lower latitudes and can exert strong selection on life‐history traits and the correlations among these traits. To predict the response of life‐history traits to environmental change along a latitudinal gradient, information must be obtained about genetic variance in traits and also genetic correlation between traits, that is the genetic variance‐covariance matrix,G. Here, we estimatedGfor key life‐history traits in an obligate univoltine damselfly that faces seasonal time constraints. We exposed populations to simulated native temperatures and photoperiods and common garden environmental conditions in a laboratory set‐up. Despite differences in genetic variance in these traits between populations (lower variance at northern latitudes), there was no evidence for latitude‐specific covariance of the life‐history traits. At simulated native conditions, all populations showed strong genetic and phenotypic correlations between traits that shaped growth and development. The variance–covariance matrix changed considerably when populations were exposed to common garden conditions compared with the simulated natural conditions, showing the importance of environmentally induced changes in multivariate genetic structure. Our results highlight the importance of estimating variance–covariance matrixes in environments that mimic selection pressures and not only trait variances or mean trait values in common garden conditions for understanding the trait evolution across populations and environments.
High‐efficiency genome editing using a dmc1 promoter‐controlled CRISPR/Cas9 system in maize
Authors: Feng Chao , Su Handong , Bai Han , Wang Rui , Liu Yalin , Guo Xianrui , Liu Chang , Zhang Jing , Yuan Jing , Birchler James A. , Han Fangpu
Published: March 2018

Previous studies revealed that the promoters for driving both Cas9 and sgRNAs are quite important for efficient genome editing by CRISPR/Cas9 in plants. Here, we report our results of targeted genome editing using the maize dmc1 gene promoter combined with the U3 promoter for Cas9 and sgRNA, respectively. Three loci in the maize genome were selected for targeting. The T0 plants regenerated were highly efficiently edited at the target sites with homozygous or bi‐allelic mutants accounting for about 66%. The mutations in T0 plants could be stably transmitted to the T1 generation, and new mutations could be generated in gametes or zygotes. Whole‐genome resequencing indicated that no off‐target mutations could be detected in the predicted loci with sequence similarity to the targeted site. Our results show that the dmc1 promoter‐controlled (DPC) CRISPR/Cas9 system is highly efficient in maize and provide further evidence that the optimization of the promoters used for the CRISPR/Cas9 system is important for enhancing the efficiency of targeted genome editing in plants. The evolutionary conservation of the dmc1 gene suggests its potential for use in other plant species.
Genetic differentiation in populations of Exserohilum turcicum from maize and sorghum in South Africa
Authors: Nieuwoudt A. , Human M. P. , Craven M. , Crampton B. G.
Published: March 2018

Exserohilum turcicum is the causal agent of northern leaf blight, a devastating foliar disease of maize and sorghum. Specificity of E. turcicum to either maize or sorghum has been observed previously, but molecular evidence supporting host specialization is lacking. The aim of this study was to compare the genetic structure of E. turcicum isolates collected from adjacent maize and sorghum fields in Delmas and Greytown in South Africa. In addition, the mode of reproduction of this pathogen was investigated. Isolates from maize (N = 62) and sorghum (N = 64) were screened with 12 microsatellite markers as well as a multiplex mating type PCR assay. No shared haplotypes were observed between isolates from different hosts, although shared haplotypes were detected between isolates from maize from Delmas and Greytown. Population structure and principal coordinate analyses revealed genetic differentiation between E. turcicum isolates from maize and sorghum. Analysis of molecular variance indicated higher among‐population variation when comparing populations from different hosts, than comparing populations from different locations. Lack of shared haplotypes, high proportion of private alleles, greater among‐population variance between hosts than locations and significant pairwise population differentiation indicates genetic separation between isolates from maize and sorghum. The high haplotypic diversity in combination with unequal mating type ratios and significant linkage equilibrium indicates that both sexual and asexual reproduction contributes to the population genetic structure of E. turcicum in South Africa.
Cytosolic invertases contribute to cellulose biosynthesis and influence carbon partitioning in seedlings of Arabidopsis thaliana
Authors: Barnes William J. , Anderson Charles T.
Published: March 2018

In plants, UDP‐glucose is the direct precursor for cellulose biosynthesis, and can be converted into other NDP‐sugars required for the biosynthesis of wall matrix polysaccharides. UDP‐glucose is generated from sucrose by two distinct metabolic pathways. The first pathway is the direct conversion of sucrose to UDP‐glucose and fructose by sucrose synthase. The second pathway involves sucrose hydrolysis by cytosolic invertase (CINV), conversion of glucose to glucose‐6‐phosphate and glucose‐1‐phosphate, and UDP‐glucose generation by UDP‐glucose pyrophosphorylase (UGP). Previously, Barratt et al. (Proc. Natl Acad. Sci. USA, 106, 2009 and 13124) have found that an Arabidopsis double mutant lacking CINV1 and CINV2 displayed drastically reduced growth. Whether this reduced growth is due to deficient cell wall production caused by limited UDP‐glucose supply, pleiotropic effects, or both, remained unresolved. Here, we present results indicating that the CINV/UGP pathway contributes to anisotropic growth and cellulose biosynthesis in Arabidopsis. Biochemical and imaging data demonstrate that cinv1 cinv2 seedlings are deficient in UDP‐glucose production, exhibit abnormal cellulose biosynthesis and microtubule properties, and have altered cellulose organization without substantial changes to matrix polysaccharide composition, suggesting that the CINV/UGP pathway is a key metabolic route to UDP‐glucose synthesis in Arabidopsis. Furthermore, differential responses of cinv1 cinv2 seedlings to exogenous sugar supplementation support a function of CINVs in influencing carbon partitioning in Arabidopsis. From these data and those of previous studies, we conclude that CINVs serve central roles in cellulose biosynthesis and carbon allocation in Arabidopsis.
Pilot study utilizing Fluorine‐18 fluorodeoxyglucose‐positron emission tomography/computed tomography for glycolytic phenotyping of canine mast cell tumors
Authors: Griffin Lynn R. , Thamm Doug H. , Selmic Laura E. , Ehrhart E.J. , Randall Elissa
Published: March 2018

The goal of this prospective pilot study was to use naturally occurring canine mast cell tumors of various grades and stages as a model for attempting to determine how glucose uptake and markers of biologic behavior are correlated. It was hypothesized that enhanced glucose uptake, as measured by 2‐[fluorine‐18]fluoro‐d‐glucose‐positron emission tomography/computed tomography (F18 FDG PET‐CT), would correlate with histologic grade. Dogs were recruited for this study from a population referred for treatment of cytologically or histologically confirmed mast cell tumors. Patients were staged utilizing standard of care methods (abdominal ultrasound and three view thoracic radiographs), followed by a whole body F18 FDG PET‐CT. Results of the F18 FDG PET‐CT were analyzed for possible metastasis and standard uptake value maximum (SUVmax) of identified lesions. Incisional or excisional biopsies of the accessible mast cell tumors were obtained and histology performed. Results were then analyzed to look for a possible correlation between the grade of mast cell tumors and SUVmax. A total of nine animals were included in the sample. Findings indicated that there was a correlation between grade of mast cell tumors and SUVmax as determined by F18 FDG PET‐CT (p‐value = 0.073, significance ≤ 0.1). Based on the limited power of this study, it is felt that further research to examine the relationship between glucose utilization and biologic aggressiveness in canine mast cell tumors is warranted. This study was unable to show that F18 FDG PET‐CT was a better staging tool than standard of care methods.
Modeling Missed Care: Implications for Evidence‐Based Practice
Authors: Blackman Ian , Lye Che Yee , Darmawan I Gusti Ngurah , Henderson Julie , Giles Tracey , Willis Eileen , Toffoli Luisa , Xiao Lily , Verrall Claire
Published: March 2018

Background

There is a growing nursing literature that views missed care as an inevitable consequence of work intensification associated with the rationing of nursing and material resources available to deliver care. Global studies recognize that missed care is now ubiquitous, although studies tend to be conducted in one region, rather than nationwide. This study seeks to understand the Australian context of missed care.

Aims

To explore self‐reported reasons for missed care and to identify the main factors for predicting missed care within a sample of Australian nurses and midwives working in public and private hospitals in New South Wales, Victoria, Tasmania, and South Australia.

Methods

A nonexperimental, descriptive method using Kalisch's (2006) MISSCARE survey was used. Responses from 1,195 nursing and midwifery staff with differing qualifications, English language skills, and Australian employment settings were analyzed using Rasch analysis and then modeled using the Structural Equation Modeling.

Results

The frequency of missed care on the morning shift directly impacted on higher priority care missed during the afternoon shift. Staff skill mix imbalances and perceived inadequacy of staff numbers for the work demands further exacerbated all aspects of care during afternoon shifts. Other major factors associated with missed care were the different clinical work settings and staff to patient ratios.

Linking Evidence to Action

The incidences, types, and reasons behind missed care are a multidimensional construct which can be predicted when known significant factors behind missed care are simultaneously accounted for.
AM Needs MEs
Authors: Simpson Timothy W.
Published: March 2018

This article discusses how mechanical engineers can help in filling the gaps in additive manufacturing technology. Traditionally, mechanical engineers have designed parts by selecting a material with the best known properties and then creating the shape they want. With additive manufacturing, the process is reversed. The shape is first printed, and then other processes are completed later. Every step of the process has numerous unknowns right now, and the tools, methods, and fundamental understanding needed to answer these questions do not exist. Modeling laser-powder interactions is difficult, especially since the physics and heat transfer phenomena are not fully understood in additive manufacturing systems, particularly powder-bed fusion systems. The models and simulations that have been created are computationally expensive and still undergoing validation and verification. Models are also needed to predict the residual stresses that will result and distortions that will occur. In short, mechanical engineers have a lot of work to do to help additive manufacturing reach its full potential.
Embracing 3D Printing
Authors: Vasquez Mike
Published: March 2018

This article reviews the challenges for companies while adopting three-dimensional (3D) printing technology. A big challenge for companies figuring out whether they need to invest in 3-D printing is the different types of printing systems available in the market. At a high level, there are seven different families of 3-D printing processes. Each of the seven technologies is differentiated by the materials used and how the materials are fused together to create three-dimensional objects. Another barrier is that most companies have not yet found it viable to put the processes in place to incorporate the change in design, engineering, and manufacturing production that is required. Not only capital funds are needed to purchase machines, but to effectively use the technology to create a sellable product, one also needs to have a targeted product line and clear vision of the ways that 3-D printing can help lower material costs, save energy, and simplify manufacturing and assembly.
Short Road to Next Ride
Authors: Gibson Tom
Published: March 2018

This article discusses about the Virginia Smart Road that is frequently used by automobile researchers to test new ideas and concepts. The Virginia Smart Road is a unique, state-of-the-art, closed test-bed research facility managed by the Virginia Tech Transportation Institute and owned and maintained by the Virginia Department of Transportation. Over two-dozen major non-proprietary research projects use the Smart Road for testing in a given year. Participating organizations include heavy hitters such as car manufacturers, the Department of Transportation, the National Highway Traffic Safety Administration, and the Federal Highway Administration’s Research and Innovative Technology Administration. The Smart Road features two paved lanes and three bridges, one of which ranks, at 175 feet, as the tallest state-maintained bridge in Virginia. It also has a signalized intersection; in-pavement sensors for moisture, temperature, strain, vibration, and weighing in motion; a lighting test bed; and the half-mile-long weather-making section. Some other features include an on-site data acquisition system, a high-bandwidth fiber network, a differential global positioning system base station, and traffic signal phase and timing using remote controls.
Work Buddies
Authors: Brown Alan S.
Published: March 2018

This article presents a study on the evolution and future of low cost and flexible new generation of robots. These collaborative robots – designed to work safely with and around people – combine low cost and ease of use. They are finding their way into large plants and into small factories, which can now automate batch runs that would never be economical with a conventional industrial robot. Most of these robots are similar to conventional industrial robots, but are smaller, lighter, and simpler to use. As robotics technology has matured, programming the robots (and just about everything else) has grown easier and more intuitive. Key components, such as motion and impact sensors and vision systems, combine better performance with costs low enough to sell in cheap video game controllers. Today’s robots may not be very interactive, however, the first wave of collaborative robots are finding simple tasks where they can make a difference.
Laboratories of Policy
Authors: Bhushan Bharat
Published: March 2018

This is a memoir of Bharat Bhushan about experience with technical policy and working with these policies in favor of technological advancements. According to Bhushan, engineers cannot remain outside the political process, because their expertise is needed to ensure that technical policy is crafted to do the most good {AQ: An edit is made in this sentence “According to… most good.”. Please check its validity and correct if necessary.}. Working in collaboration with politicians ensures that engineers can lobby legislators in favor of policies, educate fellow citizens on the engineering view of issues – or even run for office. There are many ways that engineers can get involved, including directly, by taking up positions on the staff of state or federal representatives – or even by running for office themselves. There is a need for engineers to gain the training and experience required to reach out to the public, both in speaking skills and in writing for a general audience. Engineers have to be champions for pro-science and pro-technology policies. They have the knowledge, passion, and drive to encourage state and federal lawmakers to implement these policies.
Analysis LED Design in Subsea Engineering
Authors: Marotta Egidio (Ed)
Published: March 2018

This article highlights some of the analysis challenges, which must be resolved, such as the examples of complex subsea equipment analyses conducted on trees and manifolds, and a vision for the future as it pertains to modeling and simulation in the context of an analysis-led design {AQ: Some edits are made in this sentence, “This article…led analysis.”. Please check and correct if necessary.}. This is just one roadmap that can have a profound impact on innovation within the Oil & Gas Industry, especially, for subsea and onshore production equipment and systems engineering. The advantages of optimization in design, especially in the early up-front engineering stages, can be best illustrated when designing a heat exchanger. While technical challenges still exist with respect to developing more accurate models, whether fluid, structural, acoustic, magnetic or multiphase flow models for boosting pumps, for subsea applications, the concept of using analysis led design methods in the up-front engineering phase has been well proven in many industries. The challenge still lies in gaining its acceptance as a routine practice for offshore and onshore applications to increase engineering efficiency.
Shape Shifting Target
Authors: Friswell Michael I.
Published: March 2018

This article is a study of morphing aircrafts, which has attracted many research groups around the globe. The unmanned aerial vehicles (UAV) have some attractive features for aeronautic research. An important factor in morphing systems is the scale of the air vehicle on which they will be incorporated. With the development of more accurate analysis tools and advanced smart materials, researchers are once again investigating compliant morphing aircraft to improve aircraft performance. Such an aircraft would have the potential to adapt and optimize their shape to improve flight performance or to achieve multi-objective mission roles. Low aspect ratio wings provide more manoeuvrability and allow for high flight speeds, but at the cost of efficiency. An aircraft can be fast or efficient, but not both. Compliant control surfaces also lack the discontinuities found in hinged mechanisms, and thus have the potential to reduce drag and noise significantly. Compliant structures are promising solutions because of their low weight and maintenance costs. Large-scale morphing on commercial aircraft may not be practical in the near term. But the application of morphing to secondary structures, such as a compliant control surface, is a realistic goal.
Making Tracks
Authors: Mintz Testa Bridget
Published: March 2018

This review discusses various challenges and solutions to tackle them on the route that the Texas Central is developing between Houston and Dallas. A privately funded high-speed rail line promises to whisk passengers from Houston to Dallas at 200 mph; however, building the project may divide rural areas even as it unites cities. Inter-regional passenger car travel and three- to five-hour air flights are increasingly plagued by delays, hassles, and bureaucratic security theater. Researchers believe high-speed rail can compete in that market, potentially transforming the way business is conducted and national geography is conceived. That is, of course, if the companies building high-speed rail lines can find the right alignments between cities without alienating residents, businesses, and farmers along the way. Texas Central Railway has chosen the Japanese Shinkansen bullet train technology for its trainsets and rail. The current plan is for all the power and passenger cars to be made in Japan.
Engine Architecture for High Efficiency at Small Core Size
Authors: Lord Wesley K. , Suciu Gabriel L. , Pratt  , Whitney
Published: March 2018

This technical article discusses architectural design and requirements for high-efficiency engines. Advanced fuel-efficient commercial aircrafts for entry into service in 2035 have quite different configurations than current transports, requiring new architectures for their jet engines. The alternative engine architecture potentially enables a high-overall pressure ratio all-axial compression system at small core size, while maintaining high compressor and turbine efficiencies. The concept engine also makes use of the reverse angled core to address the FAA 1-in-20 rule. It is noted that the reverse angled core engine concept architecture is only feasible at ultra-high bypass ration such that the core engine can be packaged within ducting positioned crosswise to the fan exit flow. Future studies would consider 3D design of the high turning ducts and compressor design technology for reduced exit Mach number to further increase exit annulus height and reduce sensitivity to tip clearances.
Sodium Metal Halide Battery Thermal Design for Improved Reliability
Authors: Bhamidipati Kanthi , Lindsey Jim , Frutschy Kris , Ajdari Amin , Browell Jim , Hólló Sandor
Published: March 2018

Cell temperature uniformity inside most batteries is important, because temperature variation leads to cell resistance variation and thus cell voltage variation during discharge–charge cycling. Voltage variation among the cells leads to accelerated degradation of the overall battery. Goal of this work was to improve cell temperature uniformity of the General Electric DurathonTM E620 battery module (600 V class, 20 kWh, 280 °C nominal temperature), which uses the sodium metal halide chemistry and convection air cooling. Computation fluid dynamics (CFD) study and bench-top testing were used to evaluate multiple battery design options. The optimized battery design was prototyped and tested, which demonstrated 3.5× increase in cooling power and 30% reduction in cell temperature difference during discharge–charge cycling. Cell temperature difference during battery float was reduced 50%. The hardware design changes were implemented into production batteries, which showed 450% improvement in reliability performance during discharge–charge cycling.
Viscoelastic Effect on the Wrinkling of an Inflated Dielectric-Elastomer Balloon
Authors: Mao Guoyong , Xiang Yuhai , Huang Xiaoqiang , Hong Wei , Lu Tongqing , Qu Shaoxing
Published: March 2018

Viscoelasticity plays an important role in the instability and performance of soft transducers. Wrinkling, an instability phenomenon commonly observed on soft materials, has been studied extensively. In this paper, we theoretically investigate the viscoelastic effect on the wrinkle formation of a dielectric-elastomer (DE) balloon subjected to combined electromechanical loads. Results show that the critical voltage for the wrinkle formation of a DE balloon gradually decreases as the material undergoes viscoelastic relaxation and finally reaches a stable value. The wrinkles in the lateral direction always have critical voltages equal to or lower than those in the longitudinal direction. What is more, the nucleation sites of wrinkles always move from the apex to the rim of DE balloon with the viscoelastic relaxation of DE. It takes less time for the DE balloon with higher pressure to reach the stable state. Higher pressure also leads to the stable wrinkle nucleation site moving closer to the fixed edge of the DE balloon. An experiment is conducted to illustrate the effect of viscoelasticity on the wrinkle propagation of a DE balloon, and the results agree well with the model predictions. This study provides a guide in the wrinkling control of a DE balloon and may help the future design of DE transducers.
Inertial Properties of Football Helmets
Authors: Funk James R. , Quesada Roberto E. , Miles Alexander M. , Crandall Jeff R.
Published: March 2018

The inertial properties of a helmet play an important role in both athletic performance and head protection. In this study, we measured the inertial properties of 37 football helmets, a National Operating Committee on Standards for Athletic Equipment (NOCSAE) size 7¼ headform, and a 50th percentile male Hybrid III dummy head. The helmet measurements were taken with the helmets placed on the Hybrid III dummy head. The center of gravity and moment of inertia were measured about six axes (x, y, z, xy, yz, and xz), allowing for a complete description of the inertial properties of the head and helmets. Total helmet mass averaged 1834±231 g, split between the shell (1377±200 g) and the facemask (457±101 g). On average, the football helmets weighed 41±5% as much as the Hybrid III dummy head. The center of gravity of the helmeted head was 1.1±3.0 mm anterior and 10.3±1.9 mm superior to the center of gravity of the bare head. The moment of inertia of the helmeted head was approximately 2.2±0.2 times greater than the bare head about all axes.
Applying a Hybrid Experimental-Computational Technique to Study Elbow Joint Ligamentous Stabilizers
Authors: Sharifi Kia Danial , Willing Ryan
Published: March 2018

Much of our understanding of the role of elbow ligaments to overall joint biomechanics has been developed through in vitro cadaver studies using joint motion simulators. The principle of superposition can be used to indirectly compute the force contributions of ligaments during prescribed motions. Previous studies have analyzed the contribution of different soft tissue structures to the stability of human elbow joints, but have limitations in evaluating the loads sustained by those tissues. This paper introduces a unique, hybrid experimental-computational technique for measuring and simulating the biomechanical contributions of ligaments to elbow joint kinematics and stability. in vitro testing of cadaveric joints is enhanced by the incorporation of fully parametric virtual ligaments, which are used in place of the native joint stabilizers to characterize the contribution of elbow ligaments during simple flexion–extension (FE) motions using the principle of superposition. Our results support previously reported findings that the anterior medial collateral ligament (AMCL) and the radial collateral ligament (RCL) are the primary soft tissue stabilizers for the elbow joint. Tuned virtual ligaments employed in this study were able to restore the kinematics and laxity of elbows to within 2 deg of native joint behavior. The hybrid framework presented in this study demonstrates promising capabilities in measuring the biomechanical contribution of ligamentous structures to joint stability.
Prediction of Pressure Variation at an Elbow Subsequent to a Liquid Slug Impact by Using Smoothed Particle Hydrodynamics
Authors: Ersin Dinçer Ali , Bozkuş Zafer , Tijsseling A. S.
Published: March 2018

Liquid slug flow driven by pressurized air in an inclined pipe with a downstream elbow is investigated numerically. As the liquid slug hits the elbow, the impact pressure and the associated force generated at the elbow may damage pipe supports as well as the pipe itself. It is essential for the design engineers of pipeline systems to accurately predict the pressure trace during the impact for safe operation. The slug arrival velocity and slug length (i.e., mass) at the elbow directly affect that pressure. In order to calculate these slug parameters just before the impact, an improved one-dimensional (1D) model proposed in the literature is used. At the elbow, pressure variation with respect to time is calculated by a recently developed computer code which uses a two-dimensional (2D) smoothed particle hydrodynamics (SPH) method. In the numerical setup, two representative initial slug lengths, one for short slugs and one for long slugs, and three different initial air tank pressures are used. The obtained numerical data are validated with available experimental results. For both short and long slugs, calculated peak pressures show great agreement with measured peak pressures.
Development of a Flexible Turbine Cooling Prediction Tool for Preliminary Design of Gas Turbines
Authors: Yin Feijia , Tiemstra Floris S. , Rao Arvind G.
Published: March 2018

As the overall pressure ratio (OPR) and turbine inlet temperature (TIT) of modern gas turbines are constantly being increased in the pursuit of increasing efficiency and specific power, the effect of bleed cooling air on the engine performance is increasingly becoming important. During the thermodynamic cycle analysis and optimization phase, the cooling bleed air requirement is either neglected or is modeled by simplified correlations, which can lead to erroneous results. In this current research, a physics-based turbine cooling prediction model, based on semi-empirical correlations for heat transfer and pressure drop, is developed and verified with turbine cooling data available in the open literature. Based on the validated model, a parametric analysis is performed to understand the variation of turbine cooling requirement with variation in TIT and OPR of future advanced engine cycles. It is found that the existing method of calculating turbine cooling air mass flow with simplified correlation underpredicts the amount of turbine cooling air for higher OPR and TIT, thus overpredicting the estimated engine efficiency.
A Numerical Investigation on NO2 Formation in a Natural Gas–Diesel Dual Fuel Engine
Authors: Li Yu , Li Hailin , Guo Hongsheng , Li Yongzhi , Yao Mingfa
Published: March 2018

This research numerically simulates the formation and destruction of nitrogen dioxide (NO2) in a natural gas (NG)–diesel dual fuel engine using commercial CFD software converge coupled with a reduced primary reference fuel (PRF) mechanism consisting of 45 species and 142 reactions. The model was validated by comparing the simulated cylinder pressure, heat release rate (HRR), and nitrogen oxide (NOx) emissions with experimental data. The validated model was used to simulate the formation and destruction of NO2 in a NG–diesel dual fuel engine. The formation of NO2 and its correlation with the local concentration of nitric oxide (NO), methane, and temperature were examined and discussed. It was revealed that NO2 was mainly formed in the interface region between the hot NO-containing combustion products and the relatively cool unburnt methane–air mixture. The NO2 formed at the early combustion stage is usually destructed to NO after the complete oxidation of methane and n-heptane, while NO2 formed during the postcombustion process survives through the expansion process and exits the engine. The increased NO2 emissions from NG–diesel dual fuel engines was formed during the post combustion process due to higher concentration of HO2 produced during the oxidation process of the unburned methane at low temperature. A detailed analysis of the chemical reactions occurring in the NO2 containing zone consisting of NO2, NO, O2, methane, etc., was conducted using a quasi-homogeneous constant volume (QHCV) model to identify the key reactions and species dominating NO2 formation and destruction. The HO2 produced during the postcombustion process of methane was identified as the primary species dominating the formation of NO2 during the post combustion expansion process. The simulation revealed the key reaction path for the formation of HO2 noted as CH4 → CH3 → CH2O → HCO → HO2, with conversion ratios of 98%, 74%, 90%, 98%, accordingly. The backward reaction of OH + NO2 = NO + HO2 consumed 34% of HO2 for the production of NO2.
The big city by-pass: Origin is important in medical students’ preference for future practice in regional cities and large towns
Authors: Weston Kathryn Mary , Garne David Lyndon , Bushnell John Alexander , Hudson Judith (Nicky)
Published: March 2018

Background: Rural clinical placement during medical training has been identified as important in addressing workforce mal-distribution in Australia. The University of Wollongong (UOW) medical school is unique in Australia in that all students undertake a 12-month continuous longitudinal-integrated-clerkship (LIC) placement in rural or regional NSW, or in the non-capital city urban centre where the university main campus is located. This paper investigates whether origin is important in medical students’intentions and preferences for future practice.Methods: Between 2010 and 2015, rural clinical school (RCS) students from Australian medical school programmes, including UOW, completed the same survey. The responsesfrom UOW students were compared to other students. The main outcome measuresinvestigated were preference for location of future practice and training, and careerpreferences. These were investigated with respect to location of origin of students.Results: UOW students preferred regional city/large town locations for future practicecompared to other RCS students. This finding strongly correlated with the non-capital city origin of UOW students. General practice/rural medicine was the career preference for one third of UOW students compared to one quarter of other students. Generalist specialist was the preference for almost half of other students. Skills developmentexperiences and outcomes were similar in both groups.Conclusions: Many students who have experienced a LIC placement in a regional or rural setting during training prefer smaller regional cities, towns or rural locations for future practice. Augmenting the rural clinical experience by affirmative action in preferential selection of students of non-capital city origin can result in more medical graduates wanting to “by-pass” the big cities.
Active feedforward noise control and signal tracking of headsets: Electroacoustic analysis and system implementation
Authors: Bai Mingsian R. , Pan Weichi , Chen Hungyu
Published: March 2018

Active noise control (ANC) of headsets is revisited in this paper. An in-depth electroacoustic analysis of the combined loudspeaker-cavity headset system is conducted on the basis of electro-mechano-acoustical analogous circuits. Model matching of the primary path and the secondary path leads to a feedforward control architecture. The ideal controller sheds some light on the key parameters that affect the noise reduction performance. Filtered-X least-mean-squares algorithm is employed to implement the feedforward controller on a digital signal processor. Since the relative delay of the primary path and the secondary path is crucial to the noise reduction performance, multirate signal processing with polyphase implementation is utilized to minimize the effective analog-digital conversion delay in the secondary path. Ad hoc decimation and interpolation filters are designed in order not to introduce excessive phase delays at the cutoff. Real-time experiments are undertaken to validate the implemented ANC system. Listening tests are also conducted to compare the fixed controller and the adaptive controller in terms of noise reduction and signal tracking performance for three noise types. The results have demonstrated that the fixed feedforward controller achieved satisfactory noise reduction performance and signal tracking quality.
Do Not Forget About Public Transportation: Analysis of the Association of Active Transportation to School Among Washington, DC Area Children With Parental Perceived Built Environment Measures
Authors: Roberts Jennifer D. , Rodkey Lindsey , Ray Rashawn , Saelens Brian E.
Published: March 2018

Background: Although the active transportation (AT) indicator received an F grade on the 2016 US Report Card on Physical Activity for Children and Youth, this AT assessment excluded public transportation. An objective of the Built Environment and Active Play Study was to assess youth AT, including public transportation, among Washington, DC area children in relation to parental perceptions of neighborhood built environment (BE) variables. Methods: Questionnaires were mailed to 2000 parents of children aged 7–12 years. AT to school (ATS) was assessed with the question: “In an average school week, how many days does your child use each of the following ways to get to and from school? (a) Walk; (b) Bike; (c) Car; (d) Bus or Metro.” Parental perceived BE data were obtained through questionnaire items, and logistic regression was conducted to determine if BE variables were associated with youth ATS. Results: The sample included 144 children (50% female; average age 9.7 years; 56.3% white; 23.7% African American; 10.4% Asian American). Over 30% used ATS-public transportation 5 days per week, and nearly 13% used ATS-walking daily. Parental perceived BE variables significantly predicted youth ATS-walking and ATS-public transportation. Conclusions: ATS-public transportation is common among Washington, DC area youth, and parental perceptions of BE can significantly predict ATS.
Adults Engaged in Sports in Early Life Have Higher Bone Mass Than Their Inactive Peers
Authors: Mantovani Alessandra Madia , de Lima Manoel Carlos Spiguel , Gobbo Luis Alberto , Ronque Enio Ricardo Vaz , Romanzini Marcelo , Turi-Lynch Bruna Camilo , Codogno Jamile Sanches , Fernandes Rômulo Araújo
Published: March 2018

Purpose: To analyze the relationship between engagement in sports in early life and bone variables among adults of both sexes.Methods: The sample was composed of 225 men and women. Demographic data were collected, and dual-energy X-ray absorptiometry was used to assess bone mineral density, bone mineral content, and lean soft tissue. Sports participation in early life was assessed by an interview including childhood and adolescence. Consumption of tobacco and alcohol was also assessed by interview and the habitual physical activity level by a pedometer.Results: Inactive men had bone mineral content around 11% lower than active men in childhood or adolescence, whereas for women, this difference represented around 14%. Active men had 74% less fat mass than inactive men in early life, and the difference was 67% for women. Early sports participation explained the differences in whole-body bone mineral content (16.8%,P-value = .005) and bone mineral density (8.8%,P-value = .015), as well as bone mineral density in lower limbs (18.9%,P-value = .001) among women.Conclusion: Adults engaged in sports in early life have higher bone mass than their inactive peers, especially women.
Oriented chiral water wires in artificial transmembrane channels
Authors: Kocsis Istvan , Sorci Mirco , Vanselous Heather , Murail Samuel , Sanders Stephanie E. , Licsandru Erol , Legrand Yves-Marie , van der Lee Arie , Baaden Marc , Petersen Poul B. , Belfort Georges , Barboiu Mihail
Published: March 2018

Chiral dipolar oriented water wires are observed inside artificial water channels embedded in supported bilayer membranes.
Stabilizing electrochemical interfaces in viscoelastic liquid electrolytes
Authors: Wei Shuya , Cheng Zhu , Nath Pooja , Tikekar Mukul D. , Li Gaojin , Archer Lynden A.
Published: March 2018

Viscoelastic liquid electrolytes composed of ultrahigh molecular weight polymer solutions stabilize electrodeposition of metals by suppressing electroconvection.
Dislocation-driven growth of two-dimensional lateral quantum-well superlattices
Authors: Zhou Wu , Zhang Yu-Yang , Chen Jianyi , Li Dongdong , Zhou Jiadong , Liu Zheng , Chisholm Matthew F. , Pantelides Sokrates T. , Loh Kian Ping
Published: March 2018

Inherent strain in lattice mismatched lateral heterostructures can help to create quantum-well superlattices in the 2D limit.
Assessment of Passive Traps Combined with High-Throughput Sequencing To Study Airborne Fungal Communities
Authors: Aguayo Jaime , Fourrier-Jeandel Céline , Husson Claude , Ioos Renaud
Published: March 2018

Techniques based on high-throughput sequencing (HTS) of environmental DNA have provided a new way of studying fungal diversity. However, these techniques suffer from a number of methodological biases which may appear at any of the steps involved in a metabarcoding study. Air is one of the most important environments where fungi can be found, because it is the primary medium of dispersal for many species. Looking ahead to future developments, it was decided to test 20 protocols, including different passive spore traps, spore recovery procedures, DNA extraction kits, and barcode loci. HTS was performed with the Illumina MiSeq platform targeting two subloci of the fungal internal transcribed spacer. Multivariate analysis and generalized linear models showed that the type of passive spore trap, the spore recovery procedure, and the barcode all impact the description of fungal communities in terms of richness and diversity when assessed by HTS metabarcoding. In contrast, DNA extraction kits did not significantly impact these results. Although passive traps may be used to describe airborne fungal communities, a study using specific real-time PCR and a mock community showed that these kinds of traps are affected by environmental conditions that may induce losses of biological material, impacting diversity and community composition results.

IMPORTANCEThe advent of high-throughput sequencing (HTS) methods, such as those offered by next-generation sequencing (NGS) techniques, has opened a new era in the study of fungal diversity in different environmental substrates. In this study, we show that an assessment of the diversity of airborne fungal communities can reliably be achieved by the use of simple and robust passive spore traps. However, a comparison of sample processing protocols showed that several methodological biases may impact the results of fungal diversity when assessed by metabarcoding. Our data suggest that identifying these biases is of paramount importance to enable a correct identification and relative quantification of community members.
Implementation of Failure Mode and Effects Analysis to the specimens flow in a population-based colorectal cancer screening programme using immunochemical faecal occult blood tests: a quality improvement project in the Milan colorectal cancer screening programme
Authors: Deandrea Silvia , Tidone Enrica , Bellini Aldo , Bisanti Luigi , Leonardo Nico Gerardo , Silvestri Anna Rita , Consonni Dario
Published: March 2018

Background

A multidisciplinary working group applied the Healthcare Failure Mode and Effects Analysis (HFMEA) approach to the flow of kits and specimens for the first-level test of a colorectal cancer screening programme using immunochemical faecal occult blood tests.

Methods

HFMEA comprised four steps: (1) identification and mapping of the process steps (subprocesses); (2) analysis of failure modes and calculation of the risk priority numbers (RPNs); (3) identification of corrective actions; and (4) follow-up and evaluation of corrective actions.

Results

The team identified 9 main failure modes, 12 effects and 34 associated causes. RPN scores ranged from 2 to 96. Failure modes within the first five positions in the ranking list ordered by RPN concerned: ‘degraded haemoglobin in the specimen’, ‘mixed-up kits’ and ‘anonymous specimen’. All of these could lead to false-negative results and/or subjects with positive tests not being recalled for assessment. The team planned corrective actions for those failure modes. As a result, the follow-up of corrective actions showed a significant decrease in the proportion of anonymous kits from 11.6 to 4.8 per 1000 (relative reduction of 59%). The HFMEA exercise led to a reduction in: missed positive tests; missed cancer and high-risk adenomas; complaints about the communication of test results to a person who never did the test; and false-negative results due either to haemoglobin degradation or an expired sampling tube.

Conclusions

HFMEA is a useful tool for reducing errors in colorectal cancer screening programmes using faecal occult blood tests and is characterised by a straightforward interpretation of results and ease of communication to healthcare managers and decision makers.
Stochastic win-stay-lose-learn promotes cooperation in the spatial public goods game
Authors: Fu Ming-Jian , Yang Han-Xin
Published: March 2018

In this paper, we propose a stochastic win-stay-lose-learn in which an individual is more likely to imitate one of its nearest neighbor’s strategy if its aspiration is not achieved. The results on the spatial public good game show that the cooperation can be greatly enhanced when the aspiration is moderate. Besides, we have studied the time evolution of the spatial distribution of strategies and the probability that cooperators and defectors choose to learn respectively.
Modeling of stellar wind from fast rotating stars
Authors: Bogovalov S. V. , Romanikhin S. M.
Published: March 2018

Two-dimensional (2D) axisymmetric hydrodynamic model for the stellar wind outflow from a fast rotating star is created. Nonuniform distribution of the pressure over the surface of the star corresponding to the condition of equilibrium in every point of plasma in the gravitational and centrifugal fields is taken into account. We also take into account the turbulence of the flow excited in the wind at Reynolds numbers [Formula: see text]. Calculations show the formation of the disklike outflow from the surface of the star at the equator which rather quickly (on the scale of the order of the radius of the star) expands into polar regions. Huge vertex is formed at high latitudes where high level of turbulence makes possible efficient diffusion of the angular moment. At the same time the turbulence is not excited at the equator. This prevents formation of the large scale disklike outflow at the equatorial plane. Dependence of the mass flux outflow on the velocity of the star rotation is obtained.
AGN torus threaded by large scale magnetic field
Authors: Dorodnitsyn A. , Kallman T.
Published: March 2018

Large scale magnetic field can be easily dragged from galactic scales toward AGN along with accreting gas. There, it can contribute to both the formation of AGN “torus” and help to remove angular momentum from the gas which fuels AGN accretion disk. However the dynamics of such gas is also strongly influenced by the radiative feedback from the inner accretion disk. Here we present results from the three-dimensional simulations of pc-scale accretion which is exposed to intense X-ray heating.
Laboratory simulation of astrophysical jets within facilities of plasma focus type
Authors: Krauz Vyacheslav I. , Beskin Vasily S. , Velikhov Evgeny P.
Published: March 2018

A laboratory simulation of astrophysical processes is one of the intensively developed areas of plasma physics. A new series of experiments has been launched recently on the plasma focus type facility in NRC Kurchatov Institute. The main goal is to study the mechanisms of the jet stabilization, due to which it can propagate at distances much greater than their transverse dimensions. The experiments with stationary gas filling revealed regimes in which a narrowly collimated plasma jet was formed, the head of which was no wider than several centimeters at jet propagation distances of up to 100[Formula: see text]cm. The PF-1000 (IFPiLM, Warsaw, Poland) and KPF-4 (SFTI, Sukhum, Abkhazia) experiments are aimed at creating profiled initial gas distributions to control the conditions of plasma jet propagation in the ambient plasma. Estimations of the dimensionless parameters, i.e. the Mach, Reynolds and Peclet numbers which were achieved during the experiments, showed that the PF-facilities can be used for the YSO jets modeling. The future experiments, which can allow one to understand the nature of the stable plasma ejections observed in many astrophysical sources, are discussed.