bluuebunny/crossref_metadata_2025 huggingface dataset:
Incretin‐based therapies and risk of pancreatic cancer in patients with type 2 diabetes: A meta‐analysis of randomized controlled trials
Authors: Wang Haining , Liu Ye , Tian Qing , Yang Jin , Lu Ran , Zhan Siyan , Haukka Jari , Hong Tianpei
Published: November 2017

Aims

To perform a meta‐analysis of randomized controlled trials (RCTs), including 6 recently published large‐scale cardiovascular outcome trials (CVOTs), to evaluate the risk of pancreatic cancer with incretin‐based therapies in patients with type 2 diabetes (T2DM).

Materials and Methods

For the period January 1, 2007 to May 1, 2017, the PubMed, Embase, Cochrane Central Register and ClininalTrials.gov databases were searched for RCTs in people with T2DM that compared incretin drugs with placebo or other antidiabetic drugs, with treatment and follow‐up durations of ≥52 weeks. Two reviewers screened the studies, extracted the data and assessed the risk of bias independently and in duplicate.

Results

A total of 33 studies (n = 79 971), including the 6 CVOTs, with 87 pancreatic cancer events were identified. Overall, the pancreatic cancer risk was not increased in patients administered incretin drugs compared with controls (Peto odds ratio [OR] 0.67, 95% confidence interval [CI] 0.44‐1.02). In the 6 CVOTs, 79 pancreatic cancer events were identified in 55 248 participants. Pooled estimates of the 6 CVOTs showed an identical tendency (Peto OR 0.65, 95% CI 0.42‐1.01). Notably, in the subgroup of participants who received treatment and follow‐up for ≥104 weeks, 84 pancreatic cancer events were identified in 59 919 participants, and a lower risk of pancreatic cancer was associated with incretin‐based therapies (Peto OR 0.62, 95% CI 0.41‐0.95).

Conclusions

Treatment with incretin drugs was not associated with an increased risk of pancreatic cancer in people with T2DM. Instead, it might protect against pancreatic malignancy in patients treated for ≥104 weeks.
Muscle strength and motor function throughout life in a cross‐sectional cohort of 180 patients with spinal muscular atrophy types 1c–4
Authors: Wadman R. I. , Wijngaarde C. A. , Stam M. , Bartels B. , Otto L. A. M. , Lemmink H. H. , Schoenmakers M. A. G. C. , Cuppen I. , van den Berg L. H. , van der Pol W. L.
Published: November 2017

Background and purpose

Natural history studies in spinal muscular atrophy (SMA) have primarily focused on infants and children. Natural history studies encompassing all age groups and SMA types are important for the interpretation of treatment effects of recently introduced survival motor neuron gene‐augmenting therapies.

Methods

We conducted a cross‐sectional study to investigate muscle strength, Hammersmith Functional Motor Scale (Expanded) score and the patterns of muscle weakness in relation to age and SMA type.

Results

We included 180 patients with SMA types 1–4 in the age range 1–77.5 years with median disease duration of 18 (range 0–65.8) years. With the exception of the early phases of disease in which children with SMA types 2 and 3 may achieve new motor skills and show a temporary increase in muscle strength, cross‐sectional data suggested that declining muscle strength and loss of motor skills over time are characteristic of all SMA types. Mean loss of strength was at least 1 point on the Medical Research Council score and 0.5 point on the Hammersmith Functional Motor Scale (Expanded) score per year. Trend lines compatible with deterioration of motor function and muscle strength started in childhood and continued into adulthood. The age at loss of specific motor skills was associated with disease severity. Triceps, deltoid, iliopsoas and quadriceps were the weakest muscles in all patients. Hierarchical cluster analysis did not show a segmental distribution of muscle weakness as suggested previously.

Conclusions

Progressive muscle weakness and loss of motor function are characteristic of all SMA types and all ages.
Optical performances of mono‐dispersed spherical YAG:Ce3+ nano‐phosphor achieved by one‐pot synthesis
Authors: Zhao Yunyun , Zhang Xiuyun , Yan Dongliang , Zhu Guisheng , Liang CaiHang , Yang Xiaoqing , Xu Huarui , Yu Aibing
Published: November 2017

Mono‐dispersed spherical YAG:Ce3+ nano‐phosphors were successfully synthesized by a one‐pot glycol‐thermal process using aluminum isopropoxide, yttrium, and cerium acetate hydrates as the precursor, (1,4)‐butanediol as the solvent, ethidenediamine as the additive agent that can both control the morphology and improve the optical performances of the as‐achieved products. The as‐prepared YAG:Ce3+ nano‐phosphors displayed mono‐dispersed spheres of about 150 nm and an improved optical performance with a quantum yield (QY) of 41% and good photostability, indicating that they have a considerable potential to be applied in solid‐state lighting or used as coatings in other optical electronic devices.
Physical forces modulate cell differentiation and proliferation processes
Authors: Schwartz Laurent , da Veiga Moreira Jorgelindo , Jolicoeur Mario
Published: November 2017

Currently, the predominant hypothesis explains cellular differentiation and behaviour as an essentially genetically driven intracellular process, suggesting a gene‐centrism paradigm. However, although many living species genetic has now been described, there is still a large gap between the genetic information interpretation and cell behaviour prediction. Indeed, the physical mechanisms underlying the cell differentiation and proliferation, which are now known or suspected to guide such as the flow of energy through cells and tissues, have been often overlooked. We thus here propose a complementary conceptual framework towards the development of an energy‐oriented classification of cell properties, that is, a mitochondria‐centrism hypothesis based on physical forces‐driven principles. A literature review on the physical–biological interactions in a number of various biological processes is analysed from the point of view of the fluid and solid mechanics, electricity and thermodynamics. There is consistent evidence that physical forces control cell proliferation and differentiation. We propose that physical forces interfere with the cell metabolism mostly at the level of the mitochondria, which in turn control gene expression. The present perspective points towards a paradigm shift complement in biology.
Hepatic Fibrosis in Dogs
Authors: Eulenberg V.M. , Lidbury J.A.
Published: November 2017

Hepatic fibrosis is commonly diagnosed in dogs, often as a sequela to chronic hepatitis (CH). The development of fibrosis is a crucial event in the progression of hepatic disease that is of prognostic value. The pathophysiology of hepatic fibrosis in human patients and rodent models has been studied extensively. Although less is known about this process in dogs, evidence suggests that fibrogenic mechanisms are similar between species and that activation of hepatic stellate cells is a key step. Diagnosis and staging of hepatic fibrosis in dogs requires histopathological examination of a liver biopsy specimen. However, performing a liver biopsy is invasive and assessment of fibrotic stage is complicated by the absence of a universally accepted staging scheme in veterinary medicine. Serum biomarkers that can discriminate among different fibrosis stages are used in human patients, but such markers must be more completely evaluated in dogs before clinical use. When successful treatment of its underlying cause is feasible, reversal of hepatic fibrosis has been shown to be possible in rodent models and human patients. Reversal of fibrosis has not been well documented in dogs, but successful treatment of CH is possible. In human medicine, better understanding of the pathomechanisms of hepatic fibrosis is leading to the development of novel treatment strategies. In time, these may be applied to dogs. This article comparatively reviews the pathogenesis of hepatic fibrosis, its diagnosis, and its treatment in dogs.
Surgical treatment of the residual periodontal pocket
Authors: Graziani Filippo , Karapetsa Dimitra , Mardas Nikolaos , Leow Natalie , Donos Nikolaos
Published: November 2017

The ultimate goal of periodontal therapy is to prevent further disease progression in order to reduce the risk of tooth loss. This objective can be achieved through a number of therapeutic modalities comprising both the nonsurgical and surgical phases of periodontal therapy. Nonsurgical periodontal treatment has been shown to control periodontal infection and to arrest progression of the disease in a significant number of cases. However, despite completion of nonsurgical treatment, a number of periodontal pockets, defined as ‘residual’, often remain. The presence of residual pockets may jeopardize tooth survival and be a risk factor of further disease progression, and ultimately tooth loss. Therefore, the aim of this review is to analyze the knowledge available on the indications for and the performance of periodontal surgical treatment of residual pockets in terms of ‘traditional’ (clinical, microbiological), patient‐based and systemic health outcomes.
Factors Driving the Promotion of Hydroelectricity: A Qualitative Comparative Analysis
Authors: Kammermann Lorenz
Published: November 2017

In the wake of the COP21 conference in Paris, the transition to a low‐carbon energy supply remains a central issue on the political agenda. The deployment of renewable energies is often challenged by multiple issues (e.g., public acceptance, landscape protection, and so forth). Political actors try to overcome such challenges with various measures; however, the policy instruments used vary greatly in their strength. This article questions what factors lead to the adoption of strong policy instruments promoting hydroelectricity. Explanatory factors are derived from Kingdon's multiple streams framework and are analyzed with fuzzy‐set qualitative comparative analysis within the Swiss cantons. The findings show that the strength of policy promoting hydroelectricity depends on the conjunction of mainly two factors: ambitious climate targets and an already well‐established hydroelectricity sector that generates large tax revenues for the cantons. Depending on the context, the strength of left‐wing and green parties as well as the current level of exploitation play an important role with the aforementioned factors.
Reviewer Acknowledgements
Authors: Smith Robert
Published: November 2017

Journal of Education and Training Studies (JETS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether JETS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 5, Number 12Anne M. Hornak, Central Michigan University, USAAntónio Calha, Polytechnic Institute of Portalegre, PortugalAubri Rote, University of North Carolina at Asheville, USACagla Atmaca, Pamukkale University, TurkeyErica D. Shifflet-Chila, Michigan State University, USAFatma Ozudogru, Usak University, TurkeyIntakhab Khan, King Abdulaziz University, Saudi ArabiaIoannis Syrmpas, University of Thessaly, GreeceJohn Bosco Azigwe, Bolgatanga Polytechnic, GhanaJohn Cowan, Edinburgh Napier University, UKKatya De Giovanni, University of Malta, MaltaLaima Kyburiene, Kaunas University of Applied Sciences, LithuaniaLinda J. Rappel, Yorkville University/University of Calgary, CanadaLisa Marie Portugal, Grand Canyon University, USALorna T. Enerva, Polytechnic University of the Philippines, PhilippinesMarcie Zaharee, The MITRE Corporation, USAMarco Antonio Catussi Paschoalotto, University of São Paulo, BrazilMaria Pavlis Korres, Hellenic Open University, GreeceMatthews Tiwaone Mkandawire, Central China Normal University, MalawiMaurizio Sajeva, Pellervo Economic Research PTT, FinlandMehmet Inan, Marmara University, TurkeyMeral Seker, Alanya Alaaddin Keykubat University, TurkeyMichail Kalogiannakis, University of Crete, GreeceMin Gui, Wuhan University, ChinaMu-hsuan Chou, Wenzao Ursuline University of Languages, TaiwanMustafa Uğraş, Fırat University, TurkeyNele Kampa, Leibniz-Institute for Science and Mathematics Education (IPN), GermanyPhil Sirinides, University of Pennsylvania, USAPuneet S. Gill, Texas A&M International University, USARichard H. Martin, Mercer University, USASamad Mirza Suzani, Islamic Azad University, IranSelloane Pitikoe, University of Kwazulu-Natal, South AfricaSimona Savelli, Università degli Studi Guglielmo Marconi, ItalySisi Chen, American University of Health Sciences, USAStamatis Papadakis, University of Crete, GreeceSuzan Kavanoz, Yıldız Technical University, TurkeyThomas K. F. Chiu, The University of Hong Kong, Hong KongTilanka Chandrasekera, Oklahoma State University, USAVeronica Rosa, University Rome, ItalyYerlan Seisenbekov, Kazakh National Pedagogical University, Kazakhstan                            Robert SmithEditorial AssistantOn behalf of,The Editorial Board of Journal of Education and Training StudiesRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAURL: http://jets.redfame.com
Hybrid-Electric Turbocharger and High-Speed SiC Variable-Frequency Drive Using Sensorless Control Algorithm
Authors: Carpenter Andrew L. , Beechner Troy L. , Tews Brian E. , Yelvington Paul E.
Published: November 2017

Electrically-assisted engine boosting systems lend themselves to better throttle response, wider effective operating ranges, and can provide the ability to extract excess energy during deceleration and high-load events (and store it in a vehicle’s onboard batteries). This can lead to better overall vehicle performance, emissions, and efficiency while allowing for further engine downsizing and increased power density.

In this research effort, a hybrid-electric turbocharger, variable-frequency drive (VFD), and novel sensorless control algorithm were developed. An 11kW permanent-magnet machine was coupled to a commercial turbocharger via an in-line, bolt-on housing attached to the compressor inlet. A high-efficiency, high-temperature variable-frequency drive, consisting of custom control and power electronics, was also developed. The variable-frequency drive uses SiC MOSFETS to achieve high-switching frequency and can be cooled using an existing engine coolant loop operating at up to 105 °C at an efficiency greater than 98%. A digital sliding mode-observer (DSMO) sensorless speed control algorithm was created to command and regulate speed and achieved ramp rates of over 68,000 rpm/sec.

A two-machine benchtop motor/generator test stand was constructed for initial testing and tuning of the VFD and sensorless control algorithm. A gas blow-down test stand was constructed to test the mechanical operation of the hybrid-electric turbocharger and speed control using the VFD. In addition, a liquid-pump cart was assembled for high-temperature testing of the VFD. Initial on-engine testing is planned for later this year. This paper intends to present a design overview of the in-line, hybrid-electric device, VFD, and performance characterization of the electronics and sensorless control algorithm.
Development of Optimal Control Strategy for a Plug-In Series Hybrid Electric Vehicle With an On-Board Engine-Generator System for Overall Fuel Economy Improvement and Reduction in Tail-Pipe Emissions
Authors: Kalia Aman V. , Fabien Brian C.
Published: November 2017

This research study focuses on determining optimal points of operation for the engine-generator system and regenerative braking at the wheels in a plug-in series hybrid electric Chevrolet Camaro. The goal is to improve overall fuel economy of the vehicle as well as reducing overall tail-pipe emissions. An abstract mathematical model of the series hybrid electric Chevrolet Camaro is being used to simulate the overall energy consumption of the vehicle. Previously tested and published control algorithms and strategies are studied, discussed and a viable scheme is chosen for optimization. The results from the optimal strategy considered are compared against the unoptimized results. An improvement of ∼ 8.9% in fuel economy and ∼ 8.2% reduction in tail-pipe emissions is estimated.
Modeling the Fuel Spray of a High Reactivity Gasoline Under Heavy-Duty Diesel Engine Conditions
Authors: Pei Yuanjiang , Torelli Roberto , Tzanetakis Tom , Zhang Yu , Traver Michael , Cleary David J. , Som Sibendu
Published: November 2017

Recent experimental studies on a production heavy-duty diesel engine have shown that gasoline compression ignition (GCI) can operate in both conventional mixing-controlled and low-temperature combustion modes with similar efficiency and lower soot emissions compared to diesel at a given engine-out NOx level. This is primarily due to the high volatility and low aromatic content of high reactivity, light-end fuels. In order to fully realize the potential of GCI in heavy-duty applications, accurate characterization of gasoline sprays for high-pressure fuel injection systems is needed to develop quantitative, three-dimensional computational fluid models that support simulation-led design efforts. In this work, the non-reacting fuel spray of a high reactivity gasoline (research octane number of ∼60, cetane number of ∼34) was modeled under typical heavy-duty diesel engine operating conditions, i.e., high temperature and pressure, in a constant-volume combustion chamber. The modeling results were compared to those of a diesel spray at the same conditions in order to understand their different behaviors due to fuel effects. The model was developed using a Lagrangian-Particle, Eulerian-Fluid approach. Predictions were validated against available experimental data generated at Michigan Technological University for a single-hole injector, and showed very good agreement across a wide range of operating conditions, including ambient pressure (3–10 MPa), temperature (800–1200 K), fuel injection pressure (100–250 MPa), and fuel temperature (327–408 K). Compared to a typical diesel spray, the gasoline spray evaporates much faster, exhibiting a much shorter liquid length and wider dispersion angle which promote gas entrainment and enhance air utilization. For gasoline, the liquid length is not sensitive to different ambient temperatures above 800 K, suggesting that the spray may have reached a “saturated” state where the transfer of energy from the hot gas to liquid has already been maximized. It was found that higher injection pressure is more effective at promoting the evaporation process for diesel than it is for gasoline. In addition, higher ambient pressure leads to a more compact spray and fuel temperature variation only has a minimal effect for both fuels.
Application of Hyperbolic Tangent Approximation Model to Gasoline Direct Injection Engine Simulation
Authors: Hosaka Tomoyuki , Sugii Taisuke , Ishii Eiji , Oryoji Kazuhiro , Sukegawa Yoshihiro
Published: November 2017

The improved fuel economy and low pollutant emissions are highly demanded for internal combustion engines. Gasoline Direct Injection (GDI) engine is the one of promising devices for highly efficient engine. However, GDI engines generally tend to emit more Particulate Matter (PM) than Port Fuel Injection (PFI) engine because the fuel sprayed from the injector can easily attach to the wall, which is the major origin of PM. Therefore, the precise analysis of the fuel/air mixture formation and the prediction of emissions are required. From the view of industrial use, Computational Fluid Dynamics (CFD) becomes a necessary tool for the various analyses including the fuel/air mixture formation, spray attachment on the cylinder wall, the in-cylinder turbulence formation, the combustion and emission etc.

In our previous study, the flow and spray simulation in internal combustion engine has been conducted using OpenFOAM®, the open-source CFD toolbox. Since the engine involves the dynamic motion such as valve and piston, the morphing and mapping approach was employed. Furthermore, by virtue of open-source code, we have developed the methodology of the hybrid simulation from the internal nozzle flow to the fuel/air mixture in order to take into account detailed breakup process nearby injector nozzle.

We expand the above research to the combustion simulation. For the combustion model, the Hyperbolic Tangent Approximation (HTA) model is adopted. The HTA model has a simple form of equation and one can easily implement; moreover, the HTA model has the following features: 1. capability of both laminar and turbulent flow, 2. the clearness of analytical derivation based on the functional approximation of the reaction progress variable distribution in a one-dimensional laminar flame. In the current study, the premixed flame is studied on a gasoline combustion engine. The simulations for in-cylinder engine are conducted with different Air/Fuel (A/F) ratio conditions, and the results are compared with the experimental results. The in-cylinder pressure agrees well with experimental results and the validity of the current methodology is confirmed.
Influence of Injection Parameters and Operating Conditions on Ignition and Combustion in Dual-Fuel Engines
Authors: Grochowina Marcus , Schiffner Michael , Tartsch Simon , Sattelmayer Thomas
Published: November 2017

Dual-Fuel (DF) engines offer great fuel flexibility since they can either run on gaseous or liquid fuels. In the case of Diesel pilot ignited DF-engines the main source of energy is provided by gaseous fuel, whereas the Diesel fuel acts only as an ignition source. Therefore, a proper autoignition of the pilot fuel is of utmost importance for combustion in DF-engines. However, autoignition of the pilot fuel suffers from lower compression temperatures of Miller or Atkinson valve timings. These valve timings are applied to increase efficiency and lower nitrogen oxide engine emissions. In order to improve the ignition, it is necessary to understand which parameters influence the ignition in DF-engines. For this purpose, experiments were conducted and the influence of parameters such as injection pressure, pilot fuel quantity, compression temperature and air-fuel equivalence ratio of the homogenous natural gas-air mixture were investigated. The experiments were performed on a periodically chargeable combustion cell using optical high-speed recordings and thermodynamic measurement techniques for pressure and temperature. The study reveals that the quality of the Diesel pilot ignition in terms of short ignition delay and a high number of ignited sprays significantly depends on the injection parameters and operating conditions. In most cases, the pilot fuel suffers from too high dilution due to its small quantity and long ignition delays. This results in a small number of ignited sprays and consequently leads to longer combustion durations. Furthermore, the experiments confirm that the natural gas of the background mixture influences the autoignition of the Diesel pilot oil.
Methods to Improve Combustion Stability, Efficiency, and Power Density of a Small, Port-Injected, Spark-Ignited, Two-Stroke Natural Gas Engine
Authors: Johnson Derek , Darzi Mahdi , Ulishney Chris , Bade Mehar , Zamani Nima
Published: November 2017

Two-stroke engines are often used for their low cost, simplicity, and power density. However, these engines suffer efficiency penalties due to fuel short-circuiting. Increasing power density has previously been an area of focus for performance two-stroke engines — such as in dirt bikes. Smaller-displacement engines have also been used to power remote controlled cars, boats, and aircraft. These engines typically rely on gasoline or higher-octane liquid fuels. However, natural gas is an inherently knock-resistant fuel and small natural gas engines and generators could see increased market penetration. Power generators typically operate at a fixed frequency with varied load, which can take advantage of intake and exhaust system tuning. In addition, stationary engines may not be subject to size restrictions of optimal intake and exhaust systems.

This paper examines methods to improve combustion stability, efficiency, and power density of a 29cc air-cooled two-stroke engine converted to operate on natural gas. Initial conversion showed significant penalties on delivery ratio, which lowered power density and efficiency. To overcome these issues a tuned intake pipe, two exhaust resonators, and a combustion dome were designed and tested. The engine was operated at 5400 RPM and fueling was adjusted to yield maximum brake-torque (MBT). All tests were conducted under wide-open throttle conditions. The intake and exhaust systems were designed based on Helmholtz resonance theory and empirical data. The engine utilized a two-piece cylinder head with removable combustion dome. The combustion dome was modified for optimal compression ratio while decreasing squish area and volume. With all designs incorporated, power increased from 0.22 kW to 1.07 kW — a factor of 4.86. Efficiency also increased from 7% to 12%. In addition to these performance gains, the coefficient of variation (COV) of indicated mean effective pressure (IMEP) decreased from just above 11% to less than 4%.
Modeling the Formation of Pollutant Emissions in Large-Bore, Lean-Burn Gas Engines
Authors: Pundle Anamol , Nicol David G. , Malte Philip C. , Hiltner Joel D.
Published: November 2017

This paper discusses chemical kinetic modeling used to analyze the formation of pollutant emissions in large-bore, lean-burn gas reciprocating engines. Pollutants considered are NOx, CO, HCHO, and UHC. A quasi-dimensional model, built as a chemical reactor network (CRN), is described. In this model, the flame front is treated as a perfectly stirred reactor (PSR) followed by a plug flow reactor (PFR), and reaction in the burnt gas is modeled assuming a batch reactor of constant-pressure and fixed-mass for each crank angle increment. The model treats full chemical kinetics. Engine heat loss is treated by incorporating the Woschni model into the CRN. The mass burn rate is selected so that the modeled cylinder pressure matches the experiment pressure trace. Originally, the model was developed for large, low speed, two-stoke, lean-burn engines. However, recently, the model has been formatted for the four-stroke, open-chamber, lean-burn engine. The focus of this paper is the application of the model to a four-stroke engine. This is a single-cylinder non-production variant of a heavy duty lean-burn engine of about 5 liters cylinder displacement Engine speed is 1500 RPM. Key findings of this work are the following. 1) Modeled NOx and CO are found to agree closely with emission measurements for this engine over a range of relative air-fuel ratios tested. 2) This modeling shows the importance of including N2O chemistry in the NOx calculation. For λ = 1.7, the model indicates that about 30% of the NOx emitted is formed by the N2O mechanism, with the balance from the Zeldovich mechanism. 3) The modeling shows that the CO and HCHO emissions arise from partial oxidation late in the expansion stroke as unburned charge remaining mixes into the burnt gas. 4) Model generated plots of HCHO versus CH4 emission for the four-stroke engine are in agreement with field data for large-bore, lean-burn, gas reciprocating engines. Also, recent engine tests show the correlation of UHC and CO emissions to crevice volume. These tests suggest that HCHO emissions also are affected by crevice flows through partial oxidation of UHC late in the expansion stroke.
Pilot Injection of Reactive Fuels as Ignition Source in Natural Gas Engines With Lean Burn Concept
Authors: Rosenthal Felix , Kubach Heiko , Koch Thomas
Published: November 2017

Recent gas engines developments tend to use more excess air to reduce NOx emissions. Under these circumstances the ignition in a single cylinder research gas engine with micro pilot injection of highly ignitable fuels has been investigated. Three igniting fuels, Hydrogenated Vegetable Oil (HVO), 2-ethoxyethyl ether (2-EEE) and a Diesel/2-ethylhexyl nitrate blend have been selected by a systematical assessment and their properties have been analyzed. These fuels have been evaluated concerning their aptitude as igniting fuels and compared with diesel as reference fuel. A higher ignitability of igniting fuel reduced the ignition delay of the injected fuel and enabled the diminution of the igniting fuel fraction. A significant share of NOx emissions have been attributed to the ignition injection, therefore micro pilot injection is necessary to reach emission targets. The micro pilot injection of 2-EEE as a highly ignitable fuel with the highest Cetane Number showed favorably low ignition delay. Depending on the selected fuel and the igniting fuel fraction, the combustion phasing can be controlled directly by the injection timing. In the last section, the results for pilot injection with 2-EEE as an igniting fuel have been compared with the results using a conventional spark plug. Advantages and disadvantages for both ignition systems have been identified at constant Air Fuel Ratio (AFR). A thermodynamical comparison with each ignition system has been performed to explain the different effects on combustion.
An Experimental Investigation on Performance, Combustion and Emission Characteristics of a Low Heat Rejection Engine Using Diesel and Diethyl Ether Blends
Authors: Selvaraj Krishnamani , Thangavel Mohanraj , Bikramsingh Ravikumar
Published: November 2017

This research work investigates the performance, combustion and emission characteristics of a low heat rejection engine operated on diesel and diethyl ether blends. The combustion chamber walls of the diesel engine insulated by ceramic material were referred to as low heat rejection (LHR) engine. In the LHR engine, an improvement in fuel economy would be obtained by recovering the waste heat rejected to the cooling system as useful work. Initially, the diesel fuel was tested in the conventional engine as a baseline reading for comparison. Then the engine was insulated by coating the engine components of the piston crown and the cylinder liner with aluminum titanate using plasma spray method. In this work, the experiments are conducted using diesel and diethyl ether blends in a conventional and low heat rejection engine at constant speed condition. The experimental results indicate that the brake thermal efficiency increases with increased percentage of diethyl ether in the blends. The maximum brake thermal efficiency was found to be 33.24% for LHR engine using diesel-diethyl ether blend (Diesel 85% & Diethyl ether 15% by volume) at full load condition. The emissions of carbon monoxide and hydrocarbon are decreased due to better combustion characteristics and higher NOx emissions are observed with low heat rejection engine (LHR) compared to the conventional engine using diesel and blended fuels.
Boston University geologist fights for his job
Authors: Wadman Meredith
Published: November 2017

Marchant appeals finding that he sexually harassed grad student in Antarctica 18 years ago
3.9 Å structure of the yeast Mec1-Ddc2 complex, a homolog of human ATR-ATRIP
Authors: Wang Xuejuan , Ran Tingting , Zhang Xuan , Xin Jiyu , Zhang Zhihui , Wu Tengwei , Wang Weiwu , Cai Gang
Published: November 2017

Holding a master regulator in check

A family of eukaryotic protein kinases, the phosphatidylinositol 3-kinase-related kinases (PIKKs), has key functions in DNA repair and nutrient sensing. In humans, ATR kinase locates DNA damage through its partner, ATRIP. Once activated, ATR initiates a cell-cycle cascade that culminates in cell-cycle arrest. Wang
et al.
determined the high-resolution structure of Mec1-Ddc2 (the yeast homolog of ATR-ATRIP) by electron microscopy. The structure shows the detailed architecture of the multidomain complex that overall forms a dimer of heterodimers. The detailed analysis of the structure reveals how an allosteric mechanism may activate the kinase.

Science
, this issue p.
1206
Giant nonlinear response at a plasmonic nanofocus drives efficient four-wave mixing
Authors: Nielsen Michael P. , Shi Xingyuan , Dichtl Paul , Maier Stefan A. , Oulton Rupert F.
Published: November 2017

A plasmonic route for mixing waves

Nonlinear optics typically requires photons to interact over distances spanning hundreds or thousands of wavelengths. Nonlinear optical devices therefore tend to be bulk components. Nielsen
et al.
used a polymer material with a high nonlinear coefficient that they embedded within a plasmonic cavity to show that the interaction length scale could be reduced dramatically. The plasmonic cavity focused the light down to the nanoscale, providing an intense electromagnetic field that induced the nonlinear process of four-wave mixing in the polymer. The technique provides a versatile platform for compact nonlinear optical devices.

Science
, this issue p.
1179
European normative values for physical fitness in children and adolescents aged 9–17 years: results from 2 779 165 Eurofit performances representing 30 countries
Authors: Tomkinson Grant R , Carver Kevin D , Atkinson Frazer , Daniell Nathan D , Lewis Lucy K , Fitzgerald John S , Lang Justin J , Ortega Francisco B
Published: November 2017

Objective

To develop sex-specific and age-specific normative values for the nine Eurofit tests in European children and adolescents aged 9–17 years.

Methods

A systematic review was undertaken to identify papers that explicitly reported descriptive results for at least one of nine Eurofit tests (measuring balance, muscular strength, muscular endurance, muscular power, flexibility, speed, speed-agility and cardiorespiratory fitness (CRF)) on children and adolescents. Data were included on apparently healthy (free from known disease/injury) children and adolescents aged 9–17 years. Following harmonisation for methodological variation where appropriate, pseudodata were generated using Monte Carlo simulation, with population-weighted sex-specific and age-specific normative centiles generated using the Lambda Mu Sigma (LMS) method. Sex-specific and age-specific differences were expressed as standardised differences in means, with the percentage of children and adolescents with healthy CRF estimated at the sex-age level.

Results

Norms were displayed as tabulated centiles and as smoothed centile curves for the nine Eurofit tests. The final dataset included 2 779 165 results on children and adolescents from 30 European countries, extracted from 98 studies. On average, 78% of boys (95% CI 72% to 85%) and 83% of girls (95% CI 71% to 96%) met the standards for healthy CRF, with the percentage meeting the standards decreasing with age. Boys performed substantially (standardised differences >0.2) better than girls on muscular strength, muscular power, muscular endurance, speed-agility and CRF tests, but worse on the flexibility test. Physical fitness generally improved at a faster rate in boys than in girls, especially during the teenage years.

Conclusion

This study provides the largest and most geographically representative sex-specific and age-specific European normative values for children and adolescents, which have utility for health and fitness screening, profiling, monitoring and surveillance.
Mitotic instability in triploid and tetraploid one-year-old eastern oyster, Crassostrea virginica, assessed by cytogenetic and flow cytometry techniques
Authors: de Sousa Joana Teixeira , Allen Standish K. , Wolfe Brittany M. , Small Jessica Moss
Published: November 2017

For commercial oyster aquaculture, triploidy has significant advantages. To produce triploids, the principal technology uses diploid × tetraploid crosses. The development of tetraploid brood stock for this purpose has been successful, but as more is understood about tetraploids, it seems clear that chromosome instability is a principal feature in oysters. This paper is a continuation of work to investigate chromosome instability in polyploid Crassostrea virginica. We established families between tetraploids—apparently stable (non-mosaic) and unstable (mosaic)—and normal reference diploids, creating triploid groups, as well as tetraploids between mosaic and non-mosaic tetraploids. Chromosome loss was about the same for triploid juveniles produced from either mosaic or non-mosaic tetraploids or from either male or female tetraploids. However, there was a statistically significant difference in chromosome loss in tetraploid juveniles produced from mosaic versus non-mosaic parents, with mosaics producing more unstable progeny. These results confirm that chromosome instability, as manifested in mosaic tetraploids, is of little concern for producing triploids, but it is clearly problematic for tetraploid breeding. Concordance between the results from cytogenetics and flow cytometry was also tested for the first time in oysters, by assessing the ploidy of individuals using both techniques. Results between the two were non-concordant.
First-principles study of intrinsic defects in CdO
Authors: Zhukov V. P. , Medvedeva N. I. , Krasilnikov V. N.
Published: November 2017

Using the density functional theory (DFT) in the GGA and LSDA + U approximations, we studied the effect of cadmium atoms in the interstitial sites and vacancies in the oxygen and cadmium sublattices on the electronic structure of rock-salt cadmium oxide (CdO). Migration of cadmium atoms into interstitial sites was shown to be unlikely. In the presence of oxygen vacancies, the behavior of CdO remains semiconducting and nonmagnetic. Cadmium vacancies induce d0 ferromagnetism and spin-dependent conductivity, which is semiconducting for spin-up electrons and is p-type metallic for spin-down electrons. The formation energies and free energies were calculated for oxygen vacancies and metallic cadmium phase, which allowed an explanation to be offered for the large number of vacancies and the metallic phase formed during reduction in hydrogen atmosphere.
The PLA and Taiwan Policy under Xi Jinping: One Joint Actor without Its Own Agenda
Authors: DING ARTHUR S.
Published: November 2017

After the Chinese Communist Party’s 18th Party Congress was held in the fall of 2012, frequently asked questions were: Is Xi Jinping able to rein in the Chinese People’s Liberation Army (PLA) and what is the state of Chinese party-military relations? What are the implications of this status for the PLA in China’s Taiwan policy-making? What is the potential impact of Taiwan’s leadership transition on China’s Taiwan policy and on the PLA’s role?

This author argues that through a stick and carrot approach, Xi has become the leader of China, and has been able to rein in the PLA. His proactive and assertive approach in the context of China’s growing capabilities has empowered him to control the discourse of Taiwan policy. In these circumstances, the PLA will continue to be one joint actor within the relevant apparatus executing Taiwan policy without its own agenda. Uncertainty as a result of the ruling party rotation in Taiwan is unlikely to change the PLA’s role.
Sustained Activation of Rho GTPases Promotes a Synthetic Pulmonary Artery Smooth Muscle Cell Phenotype in Neprilysin Null Mice
Authors: Karoor Vijaya , Fini Mehdi A. , Loomis Zoe , Sullivan Timothy , Hersh Louis B. , Gerasimovskaya Evgenia , Irwin David , Dempsey Edward C.
Published: November 2017

Objective—

Pulmonary artery smooth muscle cells (PASMCs) from neprilysin (NEP) null mice exhibit a synthetic phenotype and increased activation of Rho GTPases compared with their wild-type counterparts. Although Rho GTPases are known to promote a contractile SMC phenotype, we hypothesize that their sustained activity decreases SM-protein expression in these cells.

Approach and Results—

PASMCs isolated from wild-type and NEP
−/−
mice were used to assess levels of SM-proteins (SM-actin, SM-myosin, SM22, and calponin) by Western blotting, and were lower in NEP
−/−
PASMCs compared with wild-type. Rac and Rho (ras homology family member) levels and activity were higher in NEP
−/−
PASMCs, and ShRNA to Rac and Rho restored SM-protein, and attenuated the enhanced migration and proliferation of NEP
−/−
PASMCs. SM-gene repressors, p-Elk-1, and Klf4 (Kruppel lung factor 4), were higher in NEP
−/−
PASMCs and decreased by shRNA to Rac and Rho. Costimulation of wild-type PASMCs with PDGF (platelet-derived growth factor) and the NEP substrate, ET-1 (endothelin-1), increased Rac and Rho activity, and decreased SM-protein levels mimicking the NEP knock-out phenotype. Activation of Rac and Rho and downstream effectors was observed in lung tissue from NEP
−/−
mice and humans with chronic obstructive pulmonary disease.

Conclusions—

Sustained Rho activation in NEP
−/−
PASMCs is associated with a decrease in SM-protein levels and increased migration and proliferation. Inactivation of RhoGDI (Rho guanine dissociation inhibitor) and RhoGAP (Rho GTPase activating protein) by phosphorylation may contribute to prolonged activation of Rho in NEP
−/−
PASMCs. Rho GTPases may thus have a role in integration of signals between vasopeptides and growth factor receptors and could influence pathways that suppress SM-proteins to promote a synthetic phenotype.
Both Autocrine Signaling and Paracrine Signaling of HB-EGF Enhance Ocular Neovascularization
Authors: Inoue Yuki , Shimazawa Masamitsu , Nakamura Shinsuke , Takata Shinsuke , Hashimoto Yuhei , Izawa Hiroshi , Masuda Tomomi , Tsuruma Kazuhiro , Sakaue Tomohisa , Nakayama Hironao , Higashiyama Shigeki , Hara Hideaki
Published: November 2017

Objective—

The incidence of blindness is increasing because of the increase in abnormal ocular neovascularization. Anti-VEGF (vascular endothelial growth factor) therapies have led to good results, although they are not a cure for the blindness. The purpose of this study was to determine what role HB-EGF (heparin-binding epidermal growth factor–like growth factor) plays in ocular angiogenesis.

Approach and Results—

We examined the role played by HB-EGF in ocular neovascularization in 2 animal models of neovascularization: laser-induced choroidal neovascularization (CNV) and oxygen-induced retinopathy. We also studied human retinal microvascular endothelial cells in culture. Our results showed that the neovascularization was decreased in both the CNV and oxygen-induced retinopathy models in HB-EGF conditional knockout mice compared with that in wild-type mice. Moreover, the expressions of HB-EGF and VEGF were increased after laser-induced CNV and oxygen-induced retinopathy, and their expression sites were located around the neovascular areas. Exposure of human retinal microvascular endothelial cells to HB-EGF and VEGF increased their proliferation and migration, and CRM-197 (cross-reactive material-197), an HB-EGF inhibitor, decreased the HB-EGF–induced and VEGF-induced cell proliferation and migration. VEGF increased the expression of
HB-EGF
mRNA. VEGF-dependent activation of EGFR (epidermal growth factor receptor)/ERK1/2 (extracellular signal-regulated kinase 1/2) signaling and cell proliferation of endothelial cells required stimulation of the ADAM17 (a disintegrin and metalloprotease) and ADAM12. CRM-197 decreased the grades of the fluorescein angiograms and size of the CNV areas in marmoset monkeys.

Conclusions—

These findings suggest that HB-EGF plays an important role in the development of CNV. Therefore, further investigations of HB-EGF are needed as a potential therapeutic target in the treatment of exudative age-related macular degeneration.
Drawing New Boundaries: Finding the Origins of Dragons in Carboniferous Plant Fossils
Authors: Poli DorothyBelle , Stoneman Lisa
Published: November 2017

Dragons thrive in gaps between and beyond spatial boundaries. Can science help explain their existence? Did humans’ investigation of natural phenomena create bits and pieces of dragon lore across cultures? The researchers used a transdisciplinary lens to reveal data unique among extant dragon origin explanations, including fossil evidence and descriptions of Carboniferous-Period plants, dragon folklore descriptions and locations and geographic correlations between the fossils and folklore. The hypothesis is that early humans came across these fossils, constructed meaning for them contextualized by current knowledge of the natural world and created or enhanced dragon lore narratives.
Boundary Layer Height and Buoyancy Determine the Horizontal Scale of Convective Self-Aggregation
Authors: Yang Da
Published: November 2017

Organized rainstorms and their associated overturning circulations can self-emerge over an ocean surface with uniform temperature in cloud-resolving simulations. This phenomenon is referred to as convective self-aggregation. Convective self-aggregation is argued to be an important building block for tropical weather systems and may help regulate tropical atmospheric humidity and thereby tropical climate stability. Here the author presents a boundary layer theory for the horizontal scale λ of 2D (x, z) convective self-aggregation by considering both the momentum and energy constraints for steady circulations. This theory suggests that λ scales with the product of the boundary layer height h and the square root of the amplitude of density variation between aggregated moist and dry regions in the boundary layer, and that this density variation mainly arises from the moisture variation due to the virtual effect of water vapor. This theory predicts the following: 1) the order of magnitude of λ is ~2000 km, 2) the aspect ratio of the boundary layer λ/h increases with surface warming, and 3) λ decreases when the virtual effect of water vapor is disabled. These predictions are confirmed using a suite of cloud-resolving simulations spanning a wide range of climates.
Monte Carlo Study of UAV-Measurable Albedo over Arctic Sea Ice
Authors: Podgorny Igor , Lubin Dan , Perovich Donald K.
Published: November 2017

In anticipation that unmanned aerial vehicles (UAVs) will have a useful role in atmospheric energy budget studies over sea ice, a Monte Carlo model is used to investigate three-dimensional radiative transfer over a highly inhomogeneous surface albedo involving open water, sea ice, and melt ponds. The model simulates the spatial variability in 550-nm downwelling irradiance and albedo that a UAV would measure above this surface and underneath an optically thick, horizontally homogeneous cloud. At flight altitudes higher than 100 m above the surface, an airborne radiometer will sample irradiances that are greatly smoothed horizontally as a result of photon multiple reflection. If one is interested in sampling the local energy budget contrasts between specific surface types, then the UAV must fly at a low altitude, typically within 20 m of the surface. Spatial upwelling irradiance variability in larger open water features, on the order of 1000 m wide, will remain apparent as high as 500 m above the surface. To fully investigate the impact of surface feature variability on the energy budget of the lower troposphere ice–ocean system, a UAV needs to fly at a variety of altitudes to determine how individual features contribute to the area-average albedo.