bluuebunny/crossref_metadata_2025 huggingface dataset:
A diagnostic tool for improved detection of Xanthomonas fragariae using a rapid and highly specific LAMP assay designed with comparative genomics
Authors: Gétaz M. , Bühlmann A. , Schneeberger P. H. H. , Van Malderghem C. , Duffy B. , Maes M. , Pothier J. F. , Cottyn B.
Published: December 2016

Molecular diagnostics of plant pathogens are crucial to prevent disease spread and to enhance food quality and security. A comparative genomics approach using genomes of different Xanthomonas species and pathovars was applied to identify highly specific targets in the genome of Xanthomonas fragariae, the causal agent of angular leaf spot of strawberry, listed under quarantine regulations in Europe. A reliable and sensitive loop‐mediated isothermal amplification (LAMP) assay was designed using a unique marker, providing a highly specific and rapid detection technique, convenient for on‐site detection. Specificity of the designed assay was tested on 37 strains from a culture collection of X. fragariae, 82 strains of other Xanthomonas species and pathovars and 11 strains of other bacterial genera isolated from strawberry leaves. A detection limit of 102 fg was achieved, approximating to 20 genome copies per reaction. When performing analyses with crude plant material, a consistent lower detection efficiency of 102 CFU mL−1 was achieved. The LAMP assay designed in this study was adapted to work on crude plant material without any prior extensive extraction steps or incubation period; moreover, it does not require advanced analytical knowledge or a fully equipped laboratory. Results were produced within 7–20 min, depending on the pathogen concentration, thus providing a high‐throughput and user‐friendly method for detection and screening of plant material in support of quarantine regulations.
Assessing Climate Change Impacts on Wildfire Exposure in Mediterranean Areas
Authors: Lozano Olga M. , Salis Michele , Ager Alan A. , Arca Bachisio , Alcasena Fermin J. , Monteiro Antonio T. , Finney Mark A. , Del Giudice Liliana , Scoccimarro Enrico , Spano Donatella
Published: December 2016

We used simulation modeling to assess potential climate change impacts on wildfire exposure in Italy and Corsica (France). Weather data were obtained from a regional climate model for the period 1981–2070 using the IPCC A1B emissions scenario. Wildfire simulations were performed with the minimum travel time fire spread algorithm using predicted fuel moisture, wind speed, and wind direction to simulate expected changes in weather for three climatic periods (1981–2010, 2011–2040, and 2041–2070). Overall, the wildfire simulations showed very slight changes in flame length, while other outputs such as burn probability and fire size increased significantly in the second future period (2041–2070), especially in the southern portion of the study area. The projected changes fuel moisture could result in a lengthening of the fire season for the entire study area. This work represents the first application in Europe of a methodology based on high resolution (250 m) landscape wildfire modeling to assess potential impacts of climate changes on wildfire exposure at a national scale. The findings can provide information and support in wildfire management planning and fire risk mitigation activities.
Mechanical and biological approaches to alleviate soil compaction in tropical soils: assessed by root growth and activity (Rb uptake) of soybean and maize grown in rotation with cover crops
Authors: Rosolem C. A. , Pivetta L. A.
Published: December 2016

Chiselling has been used to alleviate soil compaction but cover crops with deep, vigorous roots can improve root growth and activity of the cash crop for a longer time. The determination of root activity in addition to root mass or length may improve the understanding of plant response to compaction. The objective of this experiment was to evaluate root growth and activity as affected by the alleviation of soil compaction using mechanical and biological methods. The experiment was conducted in Botucatu, São Paulo, Brazil, from 2009 to 2011, on a clay, Typic Rhodudalf soil. Crop rotations including pear millet (Pennisetum glaucum), soybean (Glycine max), grain sorghum (Sorghum bicolor), maize (Zea mays), ruzi grass (Brachiaria ruziziensis) and castor bean (Ricinus communis) in plots, either chiselled or not. Root growth was assessed by core sampling and root activity was determined indirectly using rubidium injected at several depths as a marker. Root activity was instrumental in interpreting the effects of tillage and crop rotations on soil amelioration. Compared with the initial compacted condition, chiselling increased root growth and activity just for the first 18 months of the experiment, but crop rotations, mainly including ruzi grass and castor bean, increased root growth and activity in the soil profile from the second year on. Generally, root mass was poorly correlated with root activity, except in the case of ruzi grass. Introduction of ruzi grass plus castor bean into the cropping system improves not only root growth and activity in the soil profile but also soybean yield.
The tomato I gene for Fusarium wilt resistance encodes an atypical leucine‐rich repeat receptor‐like protein whose function is nevertheless dependent on SOBIR1 and SERK3/BAK1
Authors: Catanzariti Ann‐Maree , Do Huong T. T. , Bru Pierrick , de Sain Mara , Thatcher Louise F. , Rep Martijn , Jones David A.
Published: December 2016

We have identified the tomato I gene for resistance to the Fusarium wilt fungus Fusarium oxysporum f. sp. lycopersici (Fol) and show that it encodes a membrane‐anchored leucine‐rich repeat receptor‐like protein (LRR‐RLP). Unlike most other LRR‐RLP genes involved in plant defence, the I gene is not a member of a gene cluster and contains introns in its coding sequence. The I gene encodes a loopout domain larger than those in most other LRR‐RLPs, with a distinct composition rich in serine and threonine residues. The I protein also lacks a basic cytosolic domain. Instead, this domain is rich in aromatic residues that could form a second transmembrane domain. The I protein recognises the Fol Avr1 effector protein, but, unlike many other LRR‐RLPs, recognition specificity is determined in the C‐terminal half of the protein by polymorphic amino acid residues in the LRRs just preceding the loopout domain and in the loopout domain itself. Despite these differences, we show that I/Avr1‐dependent necrosis in Nicotiana benthamiana depends on the LRR receptor‐like kinases (RLKs) SERK3/BAK1 and SOBIR1. Sequence comparisons revealed that the I protein and other LRR‐RLPs involved in plant defence all carry residues in their last LRR and C‐terminal LRR capping domain that are conserved with SERK3/BAK1‐interacting residues in the same relative positions in the LRR‐RLKs BRI1 and PSKR1. Tyrosine mutations of two of these conserved residues, Q922 and T925, abolished I/Avr1‐dependent necrosis in N. benthamiana, consistent with similar mutations in BRI1 and PSKR1 preventing their interaction with SERK3/BAK1.
TaADF4, an actin‐depolymerizing factor from wheat, is required for resistance to the stripe rust pathogen Puccinia striiformis f. sp. tritici
Authors: Zhang Bing , Hua Yuan , Wang Juan , Huo Yan , Shimono Masaki , Day Brad , Ma Qing
Published: December 2016

Actin filament assembly in plants is a dynamic process, requiring the activity of more than 75 actin‐binding proteins. Central to the regulation of filament assembly and stability is the activity of a conserved family of actin‐depolymerizing factors (ADFs), whose primarily function is to regulate the severing and depolymerization of actin filaments. In recent years, the activity of ADF proteins has been linked to a variety of cellular processes, including those associated with response to stress. Herein, a wheat ADF gene, TaADF4, was identified and characterized. TaADF4 encodes a 139‐amino‐acid protein containing five F‐actin‐binding sites and two G‐actin‐binding sites, and interacts with wheat (Triticum aestivum) Actin1 (TaACT1), in planta. Following treatment of wheat, separately, with jasmonic acid, abscisic acid or with the avirulent race, CYR23, of the stripe rust pathogen Puccinia striiformis f. sp. tritici, we observed a rapid induction in accumulation of TaADF4 mRNA. Interestingly, accumulation of TaADF4 mRNA was diminished in response to inoculation with a virulent race, CYR31. Silencing of TaADF4 resulted in enhanced susceptibility to CYR23, demonstrating a role for TaADF4 in defense signaling. Using a pharmacological‐based approach, coupled with an analysis of host response to pathogen infection, we observed that treatment of plants with the actin‐modifying agent latrunculin B enhanced resistance to CYR23, including increased production of reactive oxygen species and enhancement of localized hypersensitive cell death. Taken together, these data support the hypothesis that TaADF4 positively modulates plant immunity in wheat via the modulation of actin cytoskeletal organization.
Analysis of plant hormone profiles in response to moderate dehydration stress
Authors: Urano Kaoru , Maruyama Kyonoshin , Jikumaru Yusuke , Kamiya Yuji , Yamaguchi‐Shinozaki Kazuko , Shinozaki Kazuo
Published: December 2016

Plant responses to dehydration stress are mediated by highly complex molecular systems involving hormone signaling and metabolism, particularly the major stress hormone abscisic acid (ABA) and ABA‐dependent gene expression. To understand the roles of plant hormones and their interactions during dehydration, we analyzed the plant hormone profiles with respect to dehydration responses in Arabidopsis thaliana wild‐type (WT) plants and ABA biosynthesis mutants (nced3‐2). We developed a procedure for moderate dehydration stress, and then investigated temporal changes in the profiles of ABA, jasmonic acid isoleucine (JA‐Ile), salicylic acid (SA), cytokinin (trans‐zeatin, tZ), auxin (indole‐acetic acid, IAA), and gibberellin (GA4), along with temporal changes in the expression of key genes involved in hormone biosynthesis. ABA levels increased in a bi‐phasic pattern (at the early and late phases) in response to moderate dehydration stress. JA‐Ile levels increased slightly in WT plants and strongly increased in nced3‐2 mutant plants at 72 h after the onset of dehydration. The expression profiles of dehydration‐inducible genes displayed temporal responses in an ABA‐dependent manner. The early phase of ABA accumulation correlated with the expression of touch‐inducible genes and was independent of factors involved in the major ABA regulatory pathway, including the ABA‐responsive element‐binding (AREB/ABF) transcription factor. JA‐Ile, SA, and tZ were negatively regulated during the late dehydration response phase. Transcriptome analysis revealed important roles for hormone‐related genes in metabolism and signaling during dehydration‐induced plant responses.
MAGNETIC RESONANCE IMAGING FEATURES OF INTRAVENTRICULAR EPENDYMOMAS IN Five CATS
Authors: DeJesus Antonia , Cohen Eli B. , Galban Evelyn , Suran Jantra Ngosuwan
Published: December 2016

Intraventricular ependymoma is a rare type of feline intracranial neoplasia and published information on magnetic resonance imaging (MRI) characteristics is currently lacking. The purpose of this retrospective case series study was to describe the clinical and MRI characteristics of histopathologically confirmed intraventricular ependymomas in a group of cats. Five cats met inclusion criteria. In relation to normal gray matter, ependymomas appeared hyperintense on T2W, T2W‐FLAIR, PD, and DW‐EPI images; isointense on ADC images; and had subtle to strong contrast enhancement. Some variability was seen on T2*GRE and on T1W images with masses being isointense to hyperintense. Four ependymomas were small and homogeneous, and one was centrally cavitated. All cats had obstructive hydrocephalus, transtentorial herniation, and foramen magnum herniation. Perilesional edema was identified in most cats but was questionable in one. Intraventricular ependymoma should be considered as a differential diagnosis for cats with this combination of MRI signs.
A comparative outcomes analysis evaluating clinical effectiveness in two different human placental membrane products for wound management
Authors: Johnson Eric L. , Marshall James T. , Michael Georgina M.
Published: December 2016

Advances in tissue preservation have led to the commercialization of human placental membranes for the purposes of wound management with each product being characterized by different compositions and properties. The a priori specification of the research question in this investigator‐initiated study focused on the clinical outcomes in two nonrandomized, however statistically equal and homogenous patient cohorts receiving either a viable intact cryopreserved human placental membrane (vCPM) or a dehydrated human amnion/chorion membrane (dHACM), for the management of wounds at a single center. A total of 79 patients with 101 wounds were analyzed: 40 patients with 46 wounds received vCPM and 39 patients with 55 wounds received dHACM. The proportion of wounds achieving complete wound closure was 63.0% (29/46) for vCPM and 18.2% (10/55) for dHACM (p < 0.0001) for all treated wounds combined. This is the first comparative effectiveness study to report on the clinical outcomes associated with the use of different placental wound care products once broadly implemented in the clinical setting.
Adaption of Talent Management Scale into Turkish: Sinop University Case
Authors: Kilic Elife Dogan , Serin Huseyin , Karakus Ozge , Ergene Ozkan , Corbaci E. Cihat , Kilic Nayil
Published: December 2016

As a result of globalization, talented employees have been needed in the workplace anymore. With being hired of talented employees, new understanding of management has appeared and talent management has gained importance due to this new understanding. Talent management is a kind of management understanding according to which employees feel motivated and have desire to move forward by taking the initiative, trust in their knowledge and expertise has increased, they believe that they can control the incidents and the conditions which enable them to fulfill the tasks which are suitable and meaningful for them for the sake of organizational purposes have been composed (Doğan, 2006). Talent management is composed of a five-step process, which these steps are hiring, keeping, improving, performance and strengthening personnel. The purpose of this study is to adapt the scale which was used by Oehley (2007) in the thesis of “The Development and Evaluation of a Partial Talent Management Competency Model” for prospective teachers in Turkey. The adaptation study was conducted with 133 prospective teachers who are continuing their education in the Faculty of Education of Sinop University. In the adaptation study, exploratory factor analysis and confirmatory factor analysis were conducted. The original scale is composed of 44 items. In the first step of the adaptation study, 40 items are included in the Turkish form with regard to expert opinions. As a result of exploratory factor analysis conducted, item 8 was excluded from the scale. The scale has come up with 8 sub-dimensions as it is in the original scale. To test its accuracy, confirmatory factor analysis was conducted for 39 items.
Noninvasive Parameter Identification in Rotordynamics Via Fluid Film Bearings—Linking Active Lubrication and Operational Modal Analysis
Authors: Santos Ilmar Ferreira , Svendsen Peter Kjær
Published: December 2016

In recent years, theoretical and experimental efforts have transformed the conventional tilting-pad journal bearing (TPJB) into a smart mechatronic machine element. The application of electromechanical elements into rotating systems makes feasible the generation of controllable forces over the rotor as a function of a suitable control signal. The servovalve input signal and the radial injection pressure are the two main parameters responsible for dynamically modifying the journal oil film pressure and generating active fluid film forces in controllable fluid film bearings. Such fluid film forces, resulting from a strong coupling between hydrodynamic, hydrostatic, and controllable lubrication regimes, can be used either to control or to excite rotor lateral vibrations. If “noninvasive” forces are generated via lubricant fluid film, “in situ” parameter identification can be carried out, enabling evaluation of the mechanical condition of the rotating machine. Using the lubricant fluid film as a “noninvasive calibrated shaker” is troublesome, once several transfer functions among mechanical, hydraulic, and electronic components become necessary. In this framework, the main original contribution of this paper is to show experimentally that the knowledge about the several transfer functions can be bypassed by using output-only identification techniques. This paper links controllable (active) lubrication techniques with operational modal analysis, allowing for in situ parameter identification in rotordynamics, i.e., estimation of damping ratio and natural frequencies. The experimental analysis is carried out on a rigid rotor-level system supported by one single pair of pads. The estimation of damping and natural frequencies is performed using classical experimental modal analysis (EMA) and operational modal analysis (OMA). Very good agreements between the two experimental approaches are found. Maximum values of the main input parameters, namely, servovalve voltage and radial injection pressure, are experimentally found with the objective of defining ranges of noninvasive perturbation forces.
Numerical Investigation of Film Cooling Enhancement Using Staggered Row Mixed Hole Arrangements
Authors: Jindal Prakhar , Agarwal Shubham , Sharma R. P. , Roy A. K.
Published: December 2016

The paper presents a novel study on film cooling effectiveness of a 3D flat plate with a multihole arrangement of mixed hole shapes. The film cooling arrangement consists of two rows of coolant holes, organized in a staggered pattern with an L/D (length to diameter ratio) of 10. The two rows consist of varied combinations of triangular and semi-elliptic shaped holes for the enhancement of film-cooling effectiveness. The results were obtained for a coolant to mainstream temperature ratio of 0.5 and a blowing ratio of 1.0. The computed flow temperature fields are presented in addition to the local two-dimensional streamwise and spanwise distribution of film cooling effectiveness. Validation of the results obtained from the turbulence model has been done with the experimental data of centerline film cooling effectiveness downstream of the cooling holes available in the open literature. The results showed the rapid merging of coolant jets emerging from front row of multiholes with the secondary staggered row of mixed holes. Due to the mainstream–coolant jet interaction, the strength of the counter rotating vortex pair was mitigated in the downstream region for certain arrangement of mixed hole shapes. The optimal hole combination with maximum overall effectiveness has been deduced from this study. The best configuration (M.R. VI) not only favored for the developed film, but also enhanced the averaged film cooling effectiveness to a large extent.
Physically Realizable Three-Dimensional Bone Prosthesis Design With Interpolated Microstructures
Authors: Cramer Andrew D. , Challis Vivien J. , Roberts Anthony P.
Published: December 2016

We present a new approach to designing three-dimensional, physically realizable porous femoral implants with spatially varying microstructures and effective material properties. We optimize over a simplified design domain to reduce shear stress at the bone-prosthetic interface with a constraint on the bone resorption measured using strain energy. This combination of objective and constraint aims to reduce implant failure and allows a detailed study of the implant designs obtained with a range of microstructure sets and parameters. The microstructure sets are either specified directly or constructed using shape interpolation between a finite number of microstructures optimized for multifunctional characteristics. We demonstrate that designs using varying microstructures outperform designs with a homogeneous microstructure for this femoral implant problem. Further, the choice of microstructure set has an impact on the objective values achieved and on the optimized implant designs. A proof-of-concept metal prototype fabricated via selective laser melting (SLM) demonstrates the manufacturability of designs obtained with our approach.
Parallel Computing Scheme for Three-Dimensional Long Train System Dynamics
Authors: Wu Qing , Spiryagin Maksym , Cole Colin
Published: December 2016

Simulations of three-dimensional train system dynamics for long freight railway trains with consideration being given to all degrees-of-freedom of all essential components of all vehicles have not been reported due to the challenge of long computing time. This paper developed a parallel computing scheme for three-dimensional train system dynamics. Key modeling techniques were discussed, which include modeling of longitudinal train dynamics, single vehicle system dynamics and multibody coupler systems. Assume that there are n vehicles in the train, then, n + 2 cores are needed. The first core (core 0) is used as the master core; the last core (core n + 1) is used for air brake simulation; the rest of the cores (core 1 to core n) are used for the computing of single vehicle system dynamics for all n vehicles in parallel. During the simulation, the master core collects the results from core n + 1 and then sends the air brake pressures and knuckle forces to core 1 to core n. core 1 to core n execute vehicle system dynamics simulations and then send the coupler kinematics to the master core. The details of the parallel computing scheme were presented in this paper. The feasibility of the computing scheme has been demonstrated by a simulation of a long heavy haul train that has 214 vehicles. A 3 h train trip was simulated; 216 cores were used. The accumulated computing time of all cores was about 253 days, while the wall-clock time was about 29 h. Such computing speed has made the simulations of three-dimensional train system dynamics practical.
Tool Point Frequency Response Prediction for Micromilling by Receptance Coupling Substructure Analysis
Authors: Xiaohong Lu , Zhenyuan Jia , Haixing Zhang , Shengqian Liu , Yixuan Feng , Liang Steven Y.
Published: December 2016

One of the challenges in micromilling processing is chatter, an unstable phenomenon which has a larger impact on the microdomain compared to macro one. The minimization of tool chatter is the key to good surface quality in the micromilling process, which is also related to the milling tool and the milling structure system dynamics. Frequency response function (FRF) at micromilling tool point describes dynamic behavior of the whole micromilling machine-spindle-tool system. In this paper, based on receptance coupling substructure analysis (RCSA) and the consideration of rotational degree-of-freedom, tool point frequency response function of micromilling dynamic system is obtained by combining two functions calculated from beam theory and obtained by hammer testing. And frequency response functions solved by Timoshenko's and Euler's beam theories are compared. Finally, the frequency response function is identified as the modal parameters, and the modal parameters are transformed into equivalent structural parameters of the physical system. The research work considers the difference of theoretical modeling between the micromilling and end-milling tool and provides a base for the dynamic study of the micromilling system.
A McKibben Type Sleeve Pneumatic Muscle and Integrated Mechanism for Improved Stroke Length
Authors: Cullinan Michael F. , Bourke Eamonn , Kelly Kevin , McGinn Conor
Published: December 2016

Sleeve pneumatic muscles have shown significant performance improvements over conventional air muscle design, offering increased energy efficiency, force output, and stroke length, while allowing the actuator to become a structural component. However, there remain comparatively few studies involving sleeve muscles, and current applications have not focused on their potential advantages for joints actuated antagonistically with two muscles or their application to a more general class of pneumatic artificial muscle. This research presents a modular sleeve muscle design using the McKibben type construction, with a separate membrane and braid. To further increase stroke length, an internal pulley mechanism is implemented. The performance of the sleeve muscle is compared to an equivalent unaltered muscle and shows substantial improvements in force output, stroke length, and energy efficiency. Further testing shows that the internal pulley mechanism increased the effective stroke length by 82%, albeit at the cost of reduced maximum force output.
Revisiting the Instability and Bifurcation Behavior of Soft Dielectrics
Authors: Yang Shengyou , Zhao Xuanhe , Sharma Pradeep
Published: December 2016

Development of soft electromechanical materials is critical for several tantalizing applications such as human-like robots, stretchable electronics, actuators, energy harvesting, among others. Soft dielectrics can be easily deformed by an electric field through the so-called electrostatic Maxwell stress. The highly nonlinear coupling between the mechanical and electrical effects in soft dielectrics gives rise to a rich variety of instability and bifurcation behavior. Depending upon the context, instabilities can either be detrimental, or more intriguingly, exploited for enhanced multifunctional behavior. In this work, we revisit the instability and bifurcation behavior of a finite block made of a soft dielectric material that is simultaneously subjected to both mechanical and electrical stimuli. An excellent literature already exists that has addressed the same topic. However, barring a few exceptions, most works have focused on the consideration of homogeneous deformation and accordingly, relatively fewer insights are at hand regarding the compressive stress state. In our work, we allow for fairly general and inhomogeneous deformation modes and, in the case of a neo-Hookean material, present closed-form solutions to the instability and bifurcation behavior of soft dielectrics. Our results, in the asymptotic limit of large aspect ratio, agree well with Euler's prediction for the buckling of a slender block and, furthermore, in the limit of zero aspect ratio are the same as Biot's critical strain of surface instability of a compressed homogeneous half-space of a neo-Hookean material. A key physical insight that emerges from our analysis is that soft dielectrics can be used as actuators within an expanded range of electric field than hitherto believed.
Effects of Groundwater Flow on a Ground Source Heat Pump System
Authors: Funabiki Ayako , Oguma Masahito
Published: December 2016

Heat advection by groundwater flow is known to improve the performance of ground heat exchangers (GHEs), but the effect of groundwater advection on performance is not yet fully understood. This numerical study examined how parameters related to groundwater flow, such as aquifer thickness, porosity, lithology, and groundwater flow velocity, affected the performance of a borehole GHE. Under a thin-aquifer condition (10 m, or 10% of the entire GHE length in this study), groundwater flow velocity had the greatest effect on heat flux. At a groundwater flow velocity of at least 10−4 m/s through a low-porosity aquifer filled with granite gravel with high thermal conductivity, the heat flux of a GHE was as much as 60% higher than that of a GHE in a setting without an aquifer. If the aquifer was as thick as 50 m, the high thermal conductivity of granite gravel doubled the heat flux of the GHE at a groundwater flow velocity of at least 10−5 m/s. Thus, not only groundwater flow velocity but also aquifer thickness and thermal conductivity were important factors. However, groundwater seldom flows at such high velocities, and porosity, gravel size and composition, and aquifer thickness vary regionally. Thus, in the design of ground source heat pump systems, it is not appropriate to assume a large groundwater effect.
Incorporation of Al or Hf in atomic layer deposition TiO2 for ternary dielectric gate insulation of InAlN/GaN and AlGaN/GaN metal-insulator-semiconductor-heterojunction structure
Authors: Colon Albert , Stan Liliana , Divan Ralu , Shi Junxia
Published: December 2016

This article investigates high dielectric constant gate insulators for GaN-based devices. Exploiting TiO2 as a high-κ insulator typically compromises leakage current and temperature stability of the film. In this work, the authors compare TiO2 mixed with either Al2O3 or HfO2 to form composite films Ti-Al-O and Ti-Hf-O, respectively, deposited by atomic layer deposition on both AlGaN/GaN and InAlN/GaN substrates. The authors investigated the compositional effects of the ternary compounds by varying the Al or Hf concentration, and the authors find that leakage current is reduced with increasing Al or Hf content in the film; with a maximum Al-content of 45%, leakage current is suppressed by about 2 orders of magnitude while for a maximum Hf-content of 31%, the leakage current is suppressed by more than 2 orders of magnitude compared to the reference TiO2 sample. Although the dielectric constant is reduced with increasing Al or Hf content, it is maintaining a high value down to 49, within the investigated compositional range. The crystallization temperature of the insulators was also studied and the authors found that the crystallization temperature depends on both composition and the content. For a Ti-Al-O film with Al concentration of 45%, the crystallization temperature was increased upward of 600 °C, much larger compared to that of the reference TiO2 film. The interface trap densities of the various insulators were also studied on both AlGaN/GaN and InAlN substrates. The authors found a minimal trap density of 2.2×1012 eV−1 cm−2 for the Ti-Hf-O compound with 35% Hf. In conclusion, our study reveals that the desired high-κ properties of TiO2 can be adequately maintained while improving other insulator performance factors. Moreover, Ti-Hf-O compounds displayed overall better performance than the Ti-Al-O composites.
Virtual Images: Going Through the Looking Glass
Authors: Mota Ana Rita , dos Santos João Lopes
Published: December 2016

Virtual images are often introduced through a “geometric” perspective, with little conceptual or qualitative illustrations, hindering a deeper understanding of this physical concept. In this paper, we present two rather simple observations that force a critical reflection on the optical nature of a virtual image. This approach is supported by the reflect-view, a useful device in geometrical optics classes because it allows a visual confrontation between virtual images and real objects that seemingly occupy the same region of space.
Schools and students
Authors: White Susan C.
Published: December 2016

Since October, we have been looking at two different numbers that have been used to describe the availability of physics in U.S. high schools: 60% and 95%. The U.S. Department of Education Office of Civil Rights (OCR) uses data from all public schools to calculate the 60%. AIP Statistics uses data from public and private regular and vocational schools to calculate the 95%. Last month we noted that a large part of the difference is explained by differences in the number of schools used in the denominator of the calculation. We also noted that the 95% is the proportion of seniors enrolled in schools that offer physics regularly (that is, at least in alternating years). Smaller schools are more likely to offer physics in alternating years.
Scattering of turbulent-jet wavepackets by a swept trailing edge
Authors: Piantanida Selene , Jaunet Vincent , Huber Jérôme , Wolf William R. , Jordan Peter , Cavalieri André V. G.
Published: December 2016

Installed jet noise is studied by means of a simplified configuration comprising a flat plate in the vicinity of a round jet. The effects of Mach number, jet-plate radial distance, and trailing-edge sweep angle are explored. Acoustic measurements are performed using a traversable 18-microphone azimuthal array, providing pressure data at 360 points on a cylindrical surface surrounding the jet-plate system. Key observations include a decrease, with increasing Mach number, of the relative level of the scattered field in comparison to the uninstalled jet; an exponential dependence of the scattered sound pressure level on the radial jet-plate separation; and considerable sideline noise reductions with increasing sweep angle, with which there is an overall reduction in acoustic efficiency. The measurements are compared with results obtained using a kinematic wavepacket source model, whose radiation is computed in two ways. A TGF for a semi-infinite flat plate is used to provide a low-order approximation of the scattering effect. Use of a more computationally intensive boundary element method provides additional precision. Good agreement between model predictions and experiment, encouraging from the perspective of low-cost prediction strategies, demonstrates that the models comprise the essential sound generation mechanisms.
Factors responsible for remote-frequency masking in children and adults
Authors: Leibold Lori J. , Buss Emily
Published: December 2016

Susceptibility to remote-frequency masking in children and adults was evaluated with respect to three stimulus features: (1) masker bandwidth, (2) spectral separation of the signal and masker, and (3) gated versus continuous masker presentation. Listeners were 4- to 6-year-olds, 7- to 10-year-olds, and adults. Detection thresholds for a 500-ms, 2000-Hz signal were estimated in quiet or presented with a band of noise in one of four frequency regions: 425–500 Hz, 4000–4075 Hz, 8000–8075 Hz, or 4000–10 000 Hz. In experiment 1, maskers were gated on in each 500-ms interval of a three-interval, forced-choice adaptive procedure. Masking was observed for all ages in all maskers, but the greatest masking was observed for the 4000–4075 Hz masker. These findings suggest that signal/masker spectral proximity plays an important role in remote-frequency masking, even when peripheral excitation associated with the signal and masker does not overlap. Younger children tended to have more masking than older children or adults, consistent with a reduced ability to segregate simultaneous sounds and/or listen in a frequency-selective manner. In experiment 2, detection thresholds were estimated in the same noises, but maskers were presented continuously. Masking was reduced for all ages relative to gated conditions, suggesting improved segregation and/or frequency-selective listening.
Multichannel active noise control for spatially sparse noise fields
Authors: Zhang Jihui , Abhayapala Thushara D. , Samarasinghe Prasanga N. , Zhang Wen , Jiang Shouda
Published: December 2016

Multi-channel active noise control (ANC) is currently an attractive solution for the attenuation of low-frequency noise fields, in three-dimensional space. This paper develops a controller for the case when the noise source components are sparsely distributed in space. The anti-noise signals are designed as in conventional ANC to minimize the residual errors but with an additional term containing an ℓl norm regularization applied to the signal magnitude. This results in that only secondary sources close to the noise sources are required to be active for cancellation of sparse noise fields. Adaptive algorithms with low computational complexity and faster convergence speeds are proposed.
Intestinal cells purge to eliminate pathogens
Authors: VanHook Annalisa M.
Published: December 2016

Bacterial pore-forming toxins cause intestinal epithelial cells to extrude their cytoplasm.
Risk factors for extubation failure at a level I trauma center: does the specialty of the intensivist matter?
Authors: Weinberg Jordan A , Stevens Lily R , Goslar Pamela W , Thompson Terrell M , Sanford Jessica L , Petersen Scott R
Published: December 2016

Introduction

Extubation failure in critically ill patients is associated with higher morbidity and mortality. Although predictors of failed extubation have been previously determined in intensive care unit (ICU) cohorts, relatively less attention has been directed toward this issue in patients with trauma. The aim of this study was to identify predictors of extubation failure among patients with trauma in a multidisciplinary ICU setting.

Methods

A prospective observational study of extubation failures (EF) was conducted at an American College of Surgeons level I trauma center over 3 years (2011–2013). Case–control patients (CC) were then compared with the study group (EF) with respect to demographic/clinical characteristics and outcomes. Failure of extubation was defined as reintubation within 72 hours following planned extubation.

Results

7830 patients were admitted to the trauma service and 1098 (14%) underwent mechanical ventilation. 63 patients met inclusion criteria for the EF group and 63 comprised the CC group. The overall rate of extubation failure was 5.7% and mean time to reintubation was 13.0 hours. Groups (EF vs CC) were similar for Injury Severity Score (21 vs 21), Glasgow Coma Scale at extubation (11 vs 10), number of comorbidities (1.5 vs 1.7), injury mechanism (blunt 79% vs 74%), and body mass index (27.9 vs 27.2). In addition, groups were similar with respect to weaning protocol compliance (84% vs 89%, p=0.57). EF group had significantly increased ICU length of stay (LOS) (15.7 vs 7.4 days, p<0.001), ventilator days (13.3 vs 4.8, p<0.001), and mortality (9.5% vs 0%, p=0.03). Multiple regression analysis identified that EF was associated with increased odds of: (1) temperature >38°C at time of extubation (OR 5.9, 95% CI 1.7 to 20.8), and (2) non-surgeon intensivist consultation (OR 24.2, 95% CI 5.5 to 105.9).

Conclusions

Extubation failure is associated with increased LOS, ventilator days, and mortality in patients with trauma. Fever at time of extubation is associated with extubation failure, and the presence of such should give pause in the decision to extubate. Non-surgeon intensivist involvement increases risk of extubation failure, and a surgical critical care service may be most appropriate for the management of ventilated patients with trauma.

Level of evidence

III, Prognostic and epidemiological.
An empirical method for predicting post-construction settlement of concrete face rockfill dams
Authors: Kermani Mohammad , Konrad Jean-Marie , Smith Marc
Published: December 2016

In this study, employing a database of 19 concrete face rockfill dam (CFRD) cases, two prediction methods for post-construction settlement of CFRDs are presented. In the first method, post-construction settlements are estimated using height of the embankment. In the second method, characterization of the stress–strain behavior of the compacted rockfill layers during construction allows prediction of the subsequent stress–strain–time behavior of the embankment. Knowledge of rock particles strength is necessary in both methods. In the presented methods, settlements are estimated separately for each of the three life-cycle phases: before, during, and after impoundment. The presented results show that, in addition to addressing some limitations of previous methods, the proposed approach is precise and highly practical. It also allows a better understanding of rockfill deformation mechanisms. Apart from using this method for predictive purposes, the presented graphs can be used to distinguish unexpected settlement behavior of a CFRD during its post-construction lifespan.
Object-based analysis of UAS imagery to map emergent and submerged invasive aquatic vegetation: a case study
Authors: Chabot Dominique , Dillon Christopher , Ahmed Oumer , Shemrock Adam
Published: December 2016

Small unmanned aircraft systems (UAS) combined with automated image analysis may provide an efficient alternative or complement to labour-intensive boat-based monitoring of invasive aquatic vegetation. A small mapping drone was assessed for collecting high-resolution (≤5 cm/pixel) true-colour and near-infrared imagery revealing the distribution of invasive water soldier (Stratiotes aloides) in the Trent–Severn Waterway, Ontario (Canada). We further evaluated the capacity of an object-based image analysis approach based on the Random Forests classification algorithm to map features in the imagery, chiefly emergent and submerged water soldier colonies. The imagery contained flaws and inconsistencies resulting from data collection in suboptimal weather conditions that likely negatively impacted classification performance. Nevertheless, our best-performing classification had a producer’s and user’s accuracy for water soldier of 81% and 74%, respectively, an overall accuracy of 78%, and a kappa value of 61%, indicating “substantial” accuracy. This trial provides an instructive case study on results achieved in a “real-world” application of a UAS for environmental monitoring, notably characterized by time constraints for data collection and analysis. Beyond avoiding data collection in unfavourable weather conditions, adaptations of the image segmentation process and use of a true discrete-band multispectral camera may help to improve classification accuracy, particularly of submerged vegetation.
INCOMPLETE EXCHANGE RATE PASS-THROUGH TRANSMISSION TO PRICES: AN SVAR MODEL FOR TUNISIA
Authors: CHARFI FATMA MARRAKCHI , KADRIA MOHAMED
Published: December 2016

In this paper, we tried to revisit the transmission degree of exchange rate variations to domestic prices (import prices, MPI; producer prices, PPI; and consumer prices, CPI) in Tunisia. To do this, we used the VAR–SVAR methodology, over the 2000:1–2013:12 period. The adopted mode is gathering national prices, nominal exchange rates, foreign prices and a control variable that is the interest rate. The findings highlights that the pass-through is incomplete for all considered prices. However, the degree of the exchange rate pass-through is the highest on import prices, is moderate on producer prices and is the lowest on consumer prices. Besides, the incomplete pass-through of MPI results from the pricing to market behavior and the lowest pass-through for CPI is due basically to the composition of this index which is administrated by 30% of its components. The impulse response functions analysis, that largely corroborates to the variance decomposition, shows that when the central bank conducts a restrictive monetary policy the inflation decreases without widening the output gap.
From giant birds to X-rays: Victor Lemoine (1837–97), physician and palaeontologist
Authors: Buffetaut Eric
Published: December 2016

After studying at medical schools in Reims and Paris, Victor Lemoine (1837–97) practised and taught medicine in his native city of Reims in eastern France before moving to Paris in 1889. However, his main interest was vertebrate palaeontology. He is particularly remembered for his work on the Paleocene vertebrate fauna from the Cernay Conglomerate, a fossiliferous formation that crops out at Berru hill, a short distance from Reims. From the 1870s to his death in 1897, Lemoine published a large number of papers on this fossil assemblage, which at that time was the oldest-known Tertiary vertebrate fauna in Europe, concentrating on choristoderes, giant birds and mammals. Diverging interpretations of the choristodere material resulted in conflict with the Belgian palaeontologist Louis Dollo. Lemoine's work on
Gastornis
was marred by the erroneous inclusion of non-avian elements into his skeletal reconstruction of that giant bird; the flawed reconstruction hindered for many years the recognition of the real affinities of
Gastornis
. Lemoine devoted particular attention to the diverse archaic mammals from Cernay. He emphasized their primitive and generalized characters, which made it difficult to refer them to modern orders. His medical background led him to apply innovative approaches, such as palaeohistology and palaeoneurology, to his studies on the fossils from Cernay. Lemoine's discoveries soon attracted the attention of American palaeontologists working on fossil vertebrates of similar geological age, and both E.D. Cope and H.F. Osborn visited him in Reims to examine his collections. In 1889, Lemoine moved to Paris to be closer to major scientific institutions and to devote himself exclusively to palaeontology. After Röntgen's discovery of X-rays in 1895 he quickly realized their potential for palaeontological investigations, but his untimely death at the age of 60 prevented him from developing this new approach more fully. Despite the fact that he never held an official position in a palaeontological institution, Lemoine's medical background certainly helped him to tackle interesting palaeobiological questions and his contribution to that field of research was significant.
Diversity, Serendipity, Novelty, and Coverage
Authors: Kaminskas Marius , Bridge Derek
Published: December 2016

What makes a good recommendation or good list of recommendations?

Research into recommender systems has traditionally focused on accuracy, in particular how closely the recommender’s predicted ratings are to the users’ true ratings. However, it has been recognized that other recommendation qualities—such as whether the list of recommendations is diverse and whether it contains novel items—may have a significant impact on the overall quality of a recommender system. Consequently, in recent years, the focus of recommender systems research has shifted to include a wider range of “beyond accuracy” objectives.

In this article, we present a survey of the most discussed beyond-accuracy objectives in recommender systems research: diversity, serendipity, novelty, and coverage. We review the definitions of these objectives and corresponding metrics found in the literature. We also review works that propose optimization strategies for these beyond-accuracy objectives. Since the majority of works focus on one specific objective, we find that it is not clear how the different objectives relate to each other.

Hence, we conduct a set of offline experiments aimed at comparing the performance of different optimization approaches with a view to seeing how they affect objectives other than the ones they are optimizing. We use a set of state-of-the-art recommendation algorithms optimized for recall along with a number of reranking strategies for optimizing the diversity, novelty, and serendipity of the generated recommendations. For each reranking strategy, we measure the effects on the other beyond-accuracy objectives and demonstrate important insights into the correlations between the discussed objectives. For instance, we find that rating-based diversity is positively correlated with novelty, and we demonstrate the positive influence of novelty on recommendation coverage.
The Effect of Embodied Interaction in Visual-Spatial Navigation
Authors: Zhang Ting , Li Yu-Ting , Wachs Juan P.
Published: December 2016

This article aims to assess the effect of embodied interaction on attention during the process of solving spatio-visual navigation problems. It presents a method that links operator's physical interaction, feedback, and attention. Attention is inferred through networks called Bayesian Attentional Networks (BANs). BANs are structures that describe cause-effect relationship between attention and physical action. Then, a utility function is used to determine the best combination of interaction modalities and feedback. Experiments involving five physical interaction modalities (vision-based gesture interaction, glove-based gesture interaction, speech, feet, and body stance) and two feedback modalities (visual and sound) are described. The main findings are: (i) physical expressions have an effect in the quality of the solutions to spatial navigation problems; (ii) the combination of feet gestures with visual feedback provides the best task performance.