bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of Mixture Formation of Diesel Fuel in a Small CI Engine: The Effect of Water (H2O) Injection Into Intake Port
Authors: Min Se Hun , Park Jeonghyun , Suh Hyun Kyu
Published: November 2017

The objective of this study is to investigate the effect of water injection into intake port on the performance of small CI engine. The ECFM-3Z model was applied for the combustion analysis model, and the amount of injected water were varied 10%, 20% and 30% of injected fuel mass. The results of this work were compared in terms of cylinder pressure, rate of heat release (ROHR), and the ISNO and soot emissions. It was found that the cylinder pressure was decreased from 1.2% to 9.2% when the amount of injected water was increased from 10% to 30%. In the results, NO emission significantly decreased from about 24% to about 85% when the amount of injected water increased due to the specific heat and latent heat of water. Considering the test results, the best conditions for the simultaneous reduction of NO and soot is the BTDC 05deg of injection timing and 30% of water injection mass. It can be expected the best IMEP and ISFC characteristics.
Analysis of Crank Angle-Resolved Vortex Characteristics Under High Swirl Condition in a Spark-Ignition Direct-Injection Engine
Authors: Zhao Fengnian , Ge Penghui , Zhuang Hanyang , Hung David L. S.
Published: November 2017

In-cylinder air flow structure makes significant impacts on fuel spray dispersion, fuel mixture formation, and flame propagation in spark ignition direct injection (SIDI) engines. While flow vortices can be observed during the early stage of intake stroke, it is very difficult to clearly identify their transient characteristics because these vortices are of multiple length scales with very different swirl motion strength. In this study, a high-speed time-resolved 2D particle image velocimetry (PIV) is applied to record the flow structure of in-cylinder flow field along a swirl plane at 30 mm below the injector tip. First, a discretized method using flow field velocity vectors is presented to identify the location, strength, and rotating direction of vortices at different crank angles. The transients of vortex formation and dissipation processes are revealed by tracing the location and motion of the vortex center during the intake and compression strokes. In addition, an analysis method known as the wind-rose diagram, which is implemented for meteorological application, has been adopted to show the velocity direction distributions of 100 consecutive cycles. Results show that there exists more than one vortex center during early intake stroke and their fluctuations between each cycle can be clearly visualized. In summary, this approach provides an effective way to identify the vortex structure and to track the motion of vortex center for both large-scale and small-scale vortices.
Implementation of Detailed Chemistry Mechanisms in Engine Simulations
Authors: Kundu Prithwish , Ameen Muhsin M. , Xu Chao , Unnikrishnan Umesh , Lu Tianfeng , Som Sibendu
Published: November 2017

The stiffness of large chemistry mechanisms has been proved to be a major hurdle towards predictive engine simulations. As a result, detailed chemistry mechanisms with a few thousand species need to be reduced based on target conditions so that they can be accommodated within the available computational resources. The computational cost of simulations typically increase super-linearly with the number of species and reactions. This work aims to bring detailed chemistry mechanisms within the realm of engine simulations by coupling the framework of unsteady flamelets and fast chemistry solvers. A previously developed Tabulated Flamelet Model (TFM) framework for non-premixed combustion was used in this study. The flamelet solver consists of the traditional operator-splitting scheme with VODE (Variable coefficient ODE solver) and a numerical Jacobian for solving the chemistry. In order to use detailed mechanisms with thousands of species, a new framework with the LSODES (Livermore Solver for ODEs in Sparse form) chemistry solver and an analytical Jacobian was implemented in this work. Results from 1D simulations show that with the new framework, the computational cost is linearly proportional to the number of species in a given chemistry mechanism. As a result, the new framework is 2–3 orders of magnitude faster than the conventional VODE solver for large chemistry mechanisms. This new framework was used to generate unsteady flamelet libraries for n-dodecane using a detailed chemistry mechanism with 2,755 species and 11,173 reactions. The Engine Combustion Network (ECN) Spray A experiments which consist of an igniting n-dodecane spray in turbulent, high-pressure engine conditions are simulated using large eddy simulations (LES) coupled with detailed mechanisms. A grid with 0.06 mm minimum cell size and 22 million peak cell count was implemented. The framework is validated across a range of ambient temperatures against ignition delay and liftoff lengths. Qualitative results from the simulations were compared against experimental OH and CH2O PLIF data. The models are able to capture the spatial and temporal trends in species compared to those observed in the experiments. Quantitative and qualitative comparisons between the predictions of the reduced and detailed mechanisms are presented in detail. The main goal of this study is to demonstrate that detailed reaction mechanisms (∼1000 species) can now be used in engine simulations with a linear increase in computation cost with number of species during the tabulation process and a small increase in the 3D simulation cost.
Multi-Dimensional CFD Simulations of Knocking Combustion in a CFR Engine
Authors: Pal Pinaki , Wu Yunchao , Lu Tianfeng , Som Sibendu , See Yee Chee , Le Moine Alexandra
Published: November 2017

Knock is a major impediment to achieving higher efficiency in Spark-Ignition (SI) engines. The recent trends of boosting, downsizing and downspeeding have exacerbated this issue by driving engines toward higher power density and higher load duty cycles. Apart from the engine operating conditions, fuel anti-knock quality is a major determinant of the knocking tendency in engines, as quantified by its octane number (ON). The ON of a fuel is based on an octane scale which is defined according to the standard octane rating methods for Research Octane Number (RON) and Motor Octane Number (MON). These tests are performed in a single cylinder Cooperative Fuel Research (CFR) engine. In the present work, a numerical approach was developed based on multidimensional computational fluid dynamics (CFD) to predict knocking combustion in a CFR engine. The G-equation model was employed to track the propagation of the turbulent flame front and a multi-zone model based on temperature and equivalence ratio was used to capture auto-ignition in the endgas ahead of the flame front. Furthermore, a novel methodology was developed wherein a lookup table generated from a chemical kinetic mechanism could be employed to provide laminar flame speed as an input to the G-equation model, instead of using empirical correlations. To account for fuel chemistry effects accurately and lower the computational cost, a compact 121-species primary reference fuel (PRF) skeletal mechanism was developed from a more detailed gasoline surrogate mechanism using the directed relation graph assisted sensitivity analysis (DRGASA) reduction technique. Extensive validation of the skeletal mechanism was performed against experimental data available in the literature for both homogeneous ignition delay and laminar flame speed. The skeletal mechanism was used to generate the lookup tables for laminar flame speed as a function of pressure, temperature and equivalence ratio. The engine CFD model incorporating the skeletal mechanism was employed to perform numerical simulations under RON and MON conditions for different PRFs. Parametric tests were conducted at different compression ratios and the predicted values of critical compression ratio (at knock onset), delineating the boundary between “no knock” and “knock”, were found to be in good agreement with the available experimental data. The virtual CFR engine model was, therefore, demonstrated to be capable of adequately capturing the sensitivity of knock propensity to fuel chemistry.
The Effects of Injection Timing and Injected Fuel Mass on Local Charge Conditions and Emissions for Gasoline Direct Injection Engines
Authors: Kim Doohyun , Violi Angela , Boehman André
Published: November 2017

Increased Particulate Matter (PM) emissions from Gasoline Direct Injection (GDI) engines compared to conventional Port Fuel Injection (PFI) engines have been raising concerns because of the PM’s detrimental health effects and the stringent emissions regulations. One of the widely accepted hypotheses is that local rich pockets inside the combustion chamber are the primary reason for the increased PM emissions. In this paper, we investigate the effects of injection strategies on the charge composition and local thermodynamic conditions of a light duty GDI engine, and determine their impact on PM emissions. The operation of a 1.6L GDI engine is simulated using a 3-D Computational Fluid Dynamics (CFD) code. Combustion characteristics of a 3-component gasoline surrogate (n-heptane/iso-octane/toluene) are analyzed and the effects of injection timing (300° vs 240° vs 180° BTDC) and injected fuel mass (globally stoichiometric vs fuel rich) are explored at 2000 rpm, 9.5 bar BMEP condition, focusing on the homogeneity of the charge and the formation of the gaseous species that are soot precursors. The results indicate that when the physical time for air/fuel mixing is not long enough, fuel-rich pockets are present until combustion occurs, where high concentrations of soot precursors are found, such as acetylene and pyrene. In addition, simulation results indicate that the location of wetted surface as well as the in-cylinder flow structure induced by the fuel jet hitting the piston bowl is significantly influenced by varying the injection timing, which affects subsequent air/fuel mixing. When the injected fuel mass is increased, the equivalence ratio distribution inside the combustion chamber shifts toward fuel-rich side, generating more mixtures with Φ > 1.5, where formation of acetylene and pyrene are favored.
Steady-State Calibration of a Diesel Engine in CFD Using a GPU-Based Chemistry Solver
Authors: Gao Jian , Grover Ronald O. , Gopalakrishnan Venkatesh , Diwakar Ramachandra , Elwasif Wael , Edwards K. Dean , Finney Charles E. A. , Whitesides Russell
Published: November 2017

The prospect of analysis-driven pre-calibration of a modern diesel engine is extremely valuable in order to significantly reduce hardware investments and accelerate engine designs compliant with stricter EPA fuel economy regulations. Advanced modeling tools, such as CFD, are often used with the goal of streamlining significant portions of the calibration process. The success of the methodology largely relies on the accuracy of analytical predictions, especially engine-out emissions. However, the effectiveness of CFD simulation tools for in-cylinder engine combustion is often compromised by the complexity, accuracy, and computational overhead of detailed chemical kinetics necessary for combustion calculations. The standard approach has been to use skeletal kinetic mechanisms (∼50 species) which consume acceptable computational time but with degraded accuracy.

In this work, a comprehensive demonstration and validation of the analytical pre-calibration process is presented for a passenger car diesel engine using CFD simulations with CONVERGE™ and a GPU-based chemical kinetics solver (Zero-RK, developed at Lawrence Livermore National Laboratory) on high performance computing resources to enable the use of detailed kinetic mechanisms. Diesel engine combustion computations have been conducted over 600 operating points spanning in-vehicle speed-load map, using massively parallel ensemble simulation sets on the Titan supercomputer located at the Oak Ridge Leadership Computing Facility. The results with different mesh resolutions have been analyzed to compare differences in combustion and emissions (NOx, Carbon Monoxide CO, Unburned Hydrocarbons UHC, and Smoke) with actual engine measurements. The results show improved agreement in combustion and NOx predictions with a large n-heptane mechanism consisting of 144 species and 900 reactions with refined mesh resolution; however; agreement in CO, UHC and Smoke remain a challenge.
Discharge Characteristics of Current Boosted Spark Events Under Flow Conditions
Authors: Yu Xiao , Yang Zhenyi , Yu Shui , Ives Mark , Zheng Ming
Published: November 2017

With the advancement of spark ignition engines, lean or diluted in-cylinder charge is often used to improve the engine performance. Enhanced in-cylinder charge motion is widely applied under such conditions to promote the flame propagation, which raise challenges for the spark ignition system. In this work, the spark discharging process is investigated under different flow conditions via both optical diagnosis and electrical measurement. Results show that the spark plasma channel is stretched under flow conditions. A higher discharge current can maintain the stretched spark plasma for a longer duration. Re-strikes are observed when the spark plasma is stretched to a certain extent. The frequency of re-strikes increases with increased flow velocity and decreased discharge current level. The discharge duration reduces with the increased flow velocity. The effects of gas flow on the ignition and flame kernel development are studied in a constant volume optical combustion chamber with premixed lean and stoichiometric methane air mixture. Two spark strategies with low and high discharge current are used for the ignition. The flame propagation speed of both lean and stoichiometric mixtures increases with the increased gas flow velocity. A higher discharge current level retains a more stable spark channel and improves the flame kernel development for both lean and stoichiometric conditions, especially under the higher gas flow velocity of 20 m/s.
Influence of Swirl Ratio on Diesel-Methane Dual Fuel Combustion: A CFD Investigation
Authors: Jha P. R. , Srinivasan K. K. , Krishnan S. R.
Published: November 2017

Dual fuel combustion has garnered attention in recent years because of its potential for reducing emissions of oxides of nitrogen (NOx) and particulate matter (PM) while sustaining diesel-like fuel conversion efficiencies. However, most dual fuel combustion strategies suffer from higher engine-out hydrocarbon (HC) and carbon monoxide (CO) emissions, leading to poor combustion efficiencies, especially at low loads. The present work examined computationally the effect of in-cylinder swirl on diesel-ignited methane dual fuel combustion with a focus on devising strategies for improving part-load combustion efficiencies. For this purpose, diesel-methane dual fuel combustion was studied on a heavy-duty single cylinder research engine (SCRE) platform using CONVERGE computational fluid dynamics (CFD) software. A typical low load condition (IMEP = 5.1 bar) was selected at an engine speed of 1500 rpm and a relatively high methane percentage energy substitution (PES) of 80 percent (because experiments show poorer combustion efficiencies at high methane PES) at a nominal diesel injection timing of 2 degrees BTDC (358 CAD). The closed cycle simulation was first validated with experimental results (cylinder pressure and heat release histories as well as engine-out exhaust emissions) for neat diesel and diesel-methane dual fuel combustion, respectively. Subsequently, the influence of increasing swirl ratio from 0 to 1.5 on diesel-methane dual fuel combustion was characterized. Analysis of the computational results showed that peak cylinder pressure and heat release rate increased with increasing swirl ratio while the combustion duration (as determined by CA10-80) decreases from 25 CAD at a swirl ratio of 0.05 to nearly 15 CAD at a swirl ratio of 1.5. Indicated-specific hydrocarbon (ISHC) and indicated-specific carbon monoxide (ISCO) emissions decreased by about 60 percent and 50 percent, respectively, when swirl ratio was increased from 0.05 to 1.2; however, these reductions were accompanied by a 26 percent increase in indicated-specific NOx (ISNOx) emissions under these conditions. Therefore, the present study indicates that swirl optimization is a potentially viable strategy for reducing engine-out HC and CO emissions and for improving low-load combustion efficiencies in dual fuel engines, assuming additional NOx mitigation strategies are also employed simultaneously.
Short Report: Using complaints about communication in the emergency department in communication- skills teaching
Authors: Woodward-Kron Robyn , FitzDowse Andrew , Shahbal Ibtissam , Pryor Elizabeth
Published: November 2017

Introduction: Communication is an ongoing cause of complaints in emergency departments (EDs). These complaints can be used to inform communication skills teaching. Junior doctors are an important part of the ED team, and targeting junior doctors’ communication skills, including raising awareness about why patients complain, can contribute to an improvement in quality and safety.Context: Two interns, a patient liaison officer and a communication researcher, developed an evidence-informed teaching module for junior doctors. The module aimed to raise awareness of why people complain about communication in the ED and to engage junior doctors in identifying strategies at the individual and system level to reduce patient complaints about communication. Complaints about doctors’ communication in the ED of a regional hospital over an 18-month period were collated and analysed thematically and the findings incorporated into the teaching module. Innovation: De-identified complaints were used as triggers for discussion about quality and safety, with junior doctors being asked to consider the case studies from the dual perspectives of the doctor and the patient involved, using a series of question prompts. Implications: Patient-complaint case studies from the hospital in which the teaching is implemented are a powerful way to engage junior doctors in communication quality and safety issues. Staff from quality and safety units can work collaboratively with educators to tailor this low-cost approach to different practice settings and health professional groups. The two-part module has been implemented in intern training and transition to practice for medical students.
Morphological abnormalities in some stigmaeid species of Eustigmaeus, Stigmaeus and Storchia (Acari: Raphignathoidea: Stigmaeidae)
Authors: Bingül Meryem , Doğan Sibel , Doğan Salih
Published: November 2017

Although the family Stigmaeidae is one of the most studied mite groups because of its economically important members, data on their morphological variations are very limited and still rather poorly studied. In the present study, asymmetric and numerical variations in the body setae occurring in some adult females and males are provided. The known data on morphological variations based on literature data are also provided.
Automatic error spotter gains in popularity
Authors: Chawla Dalmeet Singh
Published: November 2017

Algorithm that checks statistics in papers is highly accurate, its developers say
A wet blanket for theories of liquid water on Mars
Authors: Hand Eric
Published: November 2017

The mystery of dark streaks endures for Alfred McEwen
Obesity and the tumor microenvironment
Authors: Olson Oakley C. , Quail Daniela F. , Joyce Johanna A.
Published: November 2017

Obesity-associated inflammation promotes tumor growth and metastatic spread
How pterosaurs bred
Authors: Deeming D. Charles
Published: November 2017

Hundreds of fossil eggs elucidate embryo development and nesting behaviors of pterosaurs
Global semi-empirical relationships for correlating soil unit weight with shear wave velocity by void-ratio function
Authors: Moon Sung-Woo , Ng Yannick C.H. , Ku Taeseo
Published: November 2017

Numerous studies have attempted to relate shear wave velocity (Vs) to the geotechnical properties of soils. However, most correlations were empirically developed only for a particular site or soil type. In this study, we propose a novel approach to incorporate a generalized void ratio function with analytical phase relations for estimating the total unit weight of soils. Based on an extensively compiled soil database, the validation of the semi-empirical model was carried out and its performance was also compared against existing Vs– total unit weight correlations. Moreover, a sensitivity analysis of the model input parameters was conducted to assess their significance on total unit weight estimates. It is demonstrated that the proposed semi-empirical model is successful in providing a first-order estimate of the total unit weight of soils based on the Vs, without consideration of the overburden stresses.
Individual variation in avian avoidance behaviours in response to repeated, simulated vehicle approach
Authors: DeVault T.L. , Seamans T.W. , Blackwell B.F. , Lima S.L. , Fernández-Juricic E.
Published: November 2017

Birds exhibit variation in alert and flight behaviours in response to vehicles within and between species, but it is unclear how properties inherent to individuals influence variation in avoidance responses over time. We examined individual variation in avoidance behaviours of Brown-headed Cowbirds (Molothrus ater (Boddaert, 1783)) in response to repeated presentation of a simulated vehicle approach in a video playback scenario. We modeled temporal alert and flight behaviours to determine whether overall behavioural variation resulted primarily from variation within individuals (i.e., intraindividual variation) or between individuals (i.e., interindividual variation). We examined reaction norms (individual × treatment day) and whether birds showed plasticity in responses via habituation or sensitization. Repeatability in the response metrics for individuals was low (∼0.22 for alert and flight), indicating that model variation was due primarily to within-individual variation rather than between-individual variation. We observed sensitization in alert responses over time, but no sensitization or habituation in flight responses. Our results indicate that individuals learned to anticipate the vehicle approach but did not vary their escape behaviour, suggesting that alert and flight behaviours might be affected differently by cues associated with oncoming objects or experience with them. We consider our findings in light of the ongoing development of strategies to reduce animal–vehicle collisions.
Evaluating the Drivers to Information and Communication Technology for Effective Sustainability Initiatives in Supply Chains
Authors: Luthra Sunil , Mangla Sachin Kumar , Chan Felix T. S. , Venkatesh V. G.
Published: November 2017

Supply chain (SC) sustainability has become a global issue. To develop sustainability focused SC networks, the role of Information and Communication Technologies (ICTs) is of great significance. An effective information system and management can help not only in improving better customer service and in cost control, but also can assist planning to achieve the three pillars of sustainability (ecological, economic, and societal development), thereby enhancing business efficiency. This paper aims to identify and evaluate the drivers relevant to ICT for sustainability initiatives in SCs. The drivers are finalized through a literature survey and use of the Delphi technique. The finalized drivers are analyzed by a procedure using the fuzzy DEMATEL approach. The research findings suggest that “Government support systems and subsidies”, “Knowledge and awareness of ICT tools and techniques,” and “Information systems network design” drivers have the most significant influences in the implementation of ICT for incorporating sustainability in SCs. This work may help practitioners and researchers in strategic decision-making and in formulating effective plans for the implementation of ICT and for incorporating sustainable concepts in SCs.
EXECUTIVE’S PERSONALITY AND GROUP PERFORMANCE: THE MEDIATING ROLE OF ABSORPTIVE CAPACITY
Authors: NOWAK RADOSLAW
Published: November 2017

This project investigates whether personality could explain variance in unit’s performance via absorptive capacity. Consequently, the study proposes that an executive’s personality traits (e.g., openness to new experience) may be related to absorptive capacity — impacting in different ways the development of externally oriented potential absorptive capacity and internally oriented realised absorptive capacity. To test this model empirically, the study uses a dataset that was collected in the healthcare industry. Results obtained using structural equation modelling confirm some of the proposed relationships. Contribution to research and practitioners is discussed.
Cytoprotective Effects of Cell‐Permeable Bifunctional Antioxidant Enzyme, GST‐TAT‐SOD, against Cisplatin‐Induced Cell Damage
Authors: Pan Jianru , Li Lingling , Liang Lili , He Huocong , Su Ying , Wang Xiangling , Liu Shutao
Published: November 2017

GST‐TAT‐SOD, a cell‐permeable bifunctional antioxidant enzyme, is a potential selective radioprotector. This study aimed to investigate the cytoprotective activity of GST‐TAT‐SOD against cisplatin‐induced damage. The current study showed that cisplatin induced the formation of reactive oxygen species in normal L‐02 cells. GST‐TAT‐SOD (2000 U/mL) executed its antioxidant role by directly scavenging excess intracellular free radicals and augmenting cellular antioxidant defense such as reducing MDA level, enhancing the SOD activity, GST activity, and T‐AOC. Thus, it suppressed the growth inhibition and apoptosis of cisplatin‐treated normal cells. Meanwhile, the growth inhibition of tumor cells (SMMC‐7721) caused by cisplatin was unaffected by GST‐TAT‐SOD pretreatment. GST‐SOD, as a comparison, seemed to be powerless for related indicators as it could not enter into cells without cell‐permeating peptide. These results suggest that GST‐TAT‐SOD might be a potential cytoprotective agent for cisplatin‐induced side effects.
Contractile Responses in Spontaneously Hypertensive Rats after Transient Middle Cerebral Artery Occlusion
Authors: Grell Anne-Sofie , Mostajeran Maryam , Edvinsson Lars , Ansar Saema
Published: November 2017

Stroke is one of the leading causes of mortality and morbidity worldwide, and few therapeutic treatments have shown beneficial effect clinically. One reason for this could be the lack of risk factors incorporated into the preclinical stroke research. We have previously demonstrated phenotypic receptor changes to be one of the injurious mechanisms occurring after stroke but mostly in healthy rats. The aim of this study was to investigate if hypertension has an effect on vasoconstrictive receptor responses to endothelin 1, sarafotoxin 6c and angiotensin II after stroke by inducing transient middle cerebral artery occlusion in spontaneously hypertensive rats and Wistar-Kyoto rats using the wire-myograph. We demonstrated an increased contractile response to endothelin 1 and extracellular potassium as well as an increased carbachol-induced dilator response in the middle cerebral arteries from hypertensive rats after stroke. This study demonstrates the importance of including risk factors in experimental stroke research.
The Effect of Motion Artifacts on Near-Infrared Spectroscopy (NIRS) Data and Proposal of a Video-NIRS System
Authors: Satoh Masayuki , Okamoto Keisuke , Tabei Ken-ichi , Kida Hirotaka , Tomimoto Hidekazu , Eda Hideo
Published: November 2017

Aims: The aims of this study were (1) to investigate the influence of physical movement on near-infrared spectroscopy (NIRS) data, (2) to establish a video-NIRS system which simultaneously records NIRS data and the subject’s movement, and (3) to measure the oxygenated hemoglobin (oxy-Hb) concentration change (Δoxy-Hb) during a word fluency (WF) task. Experiment 1: In 5 healthy volunteers, we measured the oxy-Hb and deoxygenated hemoglobin (deoxy-Hb) concentrations during 11 kinds of facial, head, and extremity movements. The probes were set in the bilateral frontal regions. The deoxy-Hb concentration was increased in 85% of the measurements. Experiment 2: Using a pillow on the backrest of the chair, we established the video-NIRS system with data acquisition and video capture software. One hundred and seventy-six elderly people performed the WF task. The deoxy-Hb concentration was decreased in 167 subjects (95%). Experiment 3: Using the video-NIRS system, we measured the Δoxy-Hb, and compared it with the results of the WF task. Δoxy-Hb was significantly correlated with the number of words. Conclusion: Like the blood oxygen level-dependent imaging effect in functional MRI, the deoxy-Hb concentration will decrease if the data correctly reflect the change in neural activity. The video-NIRS system might be useful to collect NIRS data by recording the waveforms and the subject’s appearance simultaneously.
N-Terminal Prohormone of Brain Natriuretic Peptide but not C-Terminal Pre-Pro Vasopressin (Copeptin) Level is Associated with the Response to Antihypertensive Therapy in Haemodialysis Patients
Authors: Wyskida Katarzyna , Ficek Joanna , Ficek Rafał , Adamska Dagmara , Jędrzejowska Patrycja , Wajda Jarosław , Klein Dariusz , Witkowicz Joanna , Rotkegel Sylwia , Spiechowicz-Zatoń Urszula , Kocemba-Dyczek Joanna , Ciepał Jarosław , Więcek Andrzej , Olszanecka-Glinianowicz Magdalena , Chudek Jerzy
Published: November 2017

Background/Aims: Volume overload, frequently clinically asymptomatic is considered as a causative factor limiting the effectiveness of antihypertensive therapy in haemodialysis (HD) patients. Therefore, the aim of this study was to assess plasma levels of N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) and a C-terminal portion of the precursor of vasopressin (CT-proAVP, copeptin), surrogate markers of volume overload in HD patients in relation to the number of antihypertensive drugs used in the hypertension treatment. Methods: One hundred and fifty adult HD patients (92 males) were enrolled into this study. Clinical data concerning blood pressure (BP) measurements prior haemodialysis session and pharmacotherapy were collected from all patients. In addition to routine laboratory parameters, plasma levels of NT-proBNP and CT-proAVP were measured, and daily sodium and water consumption were estimated with a portion-size food frequency questionnaire. Results: Among 145 (96.7%) hypertensive HD patients, 131 were receiving antihypertensive medication. Despite antihypertensive therapy, 31.0% had inadequate BP control. Plasma concentration of NT-proBNP was associated with systolic (R=0.19; p=0.02) but not diastolic BP values and with the number of received antihypertensive drugs (R=0.21; p=0.01). The highest NT-proBNP values were observed in patients receiving 3 or more antihypertensive drugs. In contrast, no significant correlation was found between plasma CT-proAVP concentrations and BP values as well as and the number of antihypertensive drugs. Receiver operator curve analysis showed that NT-proBNP values over 13,184 pg/mL predicted the use of at least 3 antihypertensive drugs in maximal doses in the therapy of hypertension, similar analyses performed for CT-proAVP showed much less specificity. Conclusions: 1. Increased levels of NT-proBNP seems to be a better biomarker of multidrug antihypertensive therapy requirement than CT-proAVP. 2. Whether estimation of NT-proBNP in these patients will be also better biomarker than copeptin in the prediction of cardiovascular complications related to hypertension needs further investigations.
Challenge and Yield of Enrolling Racially and Ethnically Diverse Patient Populations in Low Event Rate Clinical Trials
Authors: Sheffet Alice J. , Howard George , Sam Albert , Jamil Zafar , Weaver Fred , Chiu David , Voeks Jenifer H. , Howard Virginia J. , Hughes Susan E. , Flaxman Linda , Longbottom Mary E. , Brott Thomas G.
Published: November 2017

Background and Purpose—

We report patient enrollment and retention by race and ethnicity in the CREST (Carotid Revascularization Endarterectomy Versus Stent Trial) and assess potential effect modification by race/ethnicity. In addition, we discuss the challenge of detecting differences in study outcomes when subgroups are small and the event rate is low.

Methods—

We compared 2502 patients by race, ethnicity, baseline characteristics, and primary outcome (any periprocedural stroke, death, or myocardial infarction and subsequent ipsilateral stroke up to 10 years).

Results—

Two hundred forty (9.7%) patients were minority by race (6.1%) or ethnicity (3.6%); 109 patients (4.4%) were black, 32 (1.3%) Asian, 2332 (93.4%) white, 11 (0.4%) other, and 18 (0.7%) unknown. Ninety (3.6%) were Hispanic, 2377 (95%) non-Hispanic, and 35 (1.4%) unknown. The rate of the primary end point for all patients was 10.9%±0.9% at 10 years and did not differ by race or ethnicity (
P
inter
>0.24).

Conclusions—

The proportion of minorities recruited to CREST was below their representation in the general population, and retention of minority patients was lower than for whites. Primary outcomes did not differ by race or ethnicity. However, in CREST (like other studies), the lack of evidence of a racial/ethnic difference in the treatment effect should be interpreted with caution because of low statistical power to detect such a difference.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00004732.
Bread and Class in Medieval Society: Foodways in Anatolia
Authors: Izdebski Adam , Jaworski Marcin , Üstündağ Handan , Sołtysiak Arkadiusz
Published: November 2017

Bread was a basic food staple as well as a marker of status in medieval societies. A study of Byzantine and Islamic textual sources combined with an archaeological scientific study of teeth remains from four excavated sites in modern Turkey demonstrates that literary stereotypes about access to high-quality bread may have held in densely populated urban settlements but not in society on a wider scale. Peasants, the lowest social group, also had access to high-quality bread. In regions inhabited by diverse groups, differences in food consumption did not depend on religion or culture.
Quantum Computing and Complexity in Art
Authors: Heaney Libby
Published: November 2017

The author draws on her research experience in quantum computing to discuss the conception and form of an interactive installation, CLOUD. CLOUD explores complexity in the postdigital by referencing the principles of quantum superposition, quantum entanglement and quantum measurement.
The Resurgence of the Niger-Delta Avengers (ndas) Group in the Niger-Delta Region of Nigeria: Where Does the Economic Deprivation Lie?
Authors: Bamidele Seun
Published: November 2017

The region of Niger-Delta has been emerging as a danger zone for militants. The affected states and the federal government have responded to this threat with several strategies raging from the introduction of an amnesty programme to the deployment of security forces, which are dominated by efforts to improve military capabilities, with the aim to deter militancy in the region. Despite these efforts, the Niger-Delta Avengers (ndas) militant group has remained undeterred in the region. Beyond looking at the conventional military power reductionism of militancy in the Niger-Delta region, especially in Ogoniland, this study examines the ndas’ activities in the region. The motivations and capabilities for resurgence of ndas members in the Niger-Delta region are examined along the patterns of distribution of wealth of nations, institutional capacity and stability of the states in the region. The study examines the ndas’ groups in the region with special focus on issues of deprivation and marginalisation of the inhabitants of the region. The study recommends a comprehensive strategy against ndas militant groups in the region.
Indonesian Religion as a Hybrid Media Space: Social Dramas in a Contested Realm
Authors: Postill John , Epafras Leonard Chrysostomos
Published: November 2017

The popularity of social media in Indonesia, along with the rise of political Islam, is changing the ways in which people engage with religious matters in the country. In this article, we deploy post-Bourdieuan field theory to explore Indonesia’s religious domain as a ‘hybrid media space’ – a social space mediated by old and new media agents interacting to produce viralized forms of public communication. We undertake this exploration through three viral controversies, or ‘social dramas’, triggered by a perceived breach of the religious space’s order. All three dramas involved political Islamists in contention with various political actors, namely the Muslim senator Fahira Fahmi, the West Sumatran atheist Alexander Aan, and the then governor of Jakarta, ‘Ahok’. These examples shed light on the current state of Indonesia’s religious space and its multiple mediations, as well as taking field theory into new communicative and religious terrain.
Automation and the Welfare State: Technological Change as a Determinant of Redistribution Preferences
Authors: Thewissen Stefan , Rueda David
Published: November 2017

Technological change is widely considered to be a key driver of the economic and occupational structure of affluent countries. Current advances in information technology have led to a significant substitution of routine work by capital, while occupations with abstract or interpersonal manual task structures are complemented or unaffected. We develop a simple theoretical framework for the reasons why individuals in routine task-intensive occupations would prefer public insurance against the increased risk of future income loss resulting from automation. Moreover, we contend that this relation will be stronger for richer individuals who have more to lose from automation. We focus on the role of occupational elements of risk exposure and challenge some general interpretations of the determinants of redistribution preferences. We test the implications of our theoretical framework with survey data for 17 European countries between 2002 and 2012. While up to now the political economy literature has emphasized other occupational risks, we find vulnerability to automation to be an important determinant of the demand for redistribution that should not be ignored.
Virginia’s Slavery Deliberations
Authors: Warnke Georgia
Published: November 2017

For many deliberative theorists, the importance of a public exchange of reasons lies in its capacity to improve the quality of democratic decision making. The 1831-1832 debate over abolishing slavery in Virginia in the state’s House of Delegates raises the question of whether it can do so on its own. The bigotry of those opposing the abolition of Virginian slavery was matched only by the prejudice of those advocating for its end. This paper examines James Bohman’s sophisticated defense of deliberative democracy but argues for the value of negative and disclosive experience.
Bleeding during veno-venous ECMO cannot reliably be predicted by rotational thrombelastometry (ROTEM™)
Authors: Hellmann Christina , Schmutz Axel , Kalbhenn Johannes
Published: November 2017

Introduction:

Veno-venous extracorporeal membrane oxygenation (vvECMO) used for respiratory support is associated with clinical bleeding in at least one third of patients. Mechanisms promoting bleeding, like acquired von Willebrand syndrome, cannot be identified by routine coagulation tests. This study was performed to evaluate rotational Thrombelastography (ROTEM™) for specific results predicting bleeding events during vvECMO.

Methods:

Five hundred and thirty-four ROTEM™ analyses of 57 patients over 574 days have been evaluated. Patients were graded into three groups according to the severity of bleeding, following the Freiburg ECMO bleeding assessment. ROTEM™ results and basic as well as comprehensive laboratory coagulation tests have been compared among the three groups and overall between defined time points.

Results:

Fourteen patients (25 %) presented without bleeding, 22 patients (39 %) showed mild bleeding and 21 patients (36 %) became evident with relevant clinical bleeding. No bleeding shock and no fatal bleeding event occurred. No case of hyperfibrinolysis was observed. Neither a statistical difference for ECMO blood flow nor duration of therapy among the groups could be shown. The only significant difference was clotting time (CT) in the InTEM analysis, with a median (IQR) of 175 (37.5) seconds in Group 1, 190 (54.5) seconds in Group 2 and 204 (90) seconds in Group 3. When comparing overall ROTEM™ analyses between defined time points, continuous worsening of CT can be found in ExTEM, FibTEM and ApTEM. Reduced A10, A20 and congruently maximum clot firmness, especially, developed in ExTEM and ApTEM and with a minor characteristic in InTEM, but not in FibTEM. ROTEM™ and coagulation-parameter results before 19 clinical relevant bleeding episodes compared to all other results only showed differences in FibTEM.

Conclusion:

ROTEM™ as a functional viscoelastic analysis does not provide additional information to basic and comprehensive laboratory tests during vvECMO. Bleeding events cannot be predicted by the means of specific ROTEM™ results.
Autocratic political cycle and international conflict
Authors: Bak Daehee
Published: November 2017

This article reveals a temporal pattern of conflict behavior over the course of autocratic leaders’ tenure. By identifying a commonly observed domestic political cycle in autocracies, I discuss how the level of domestic constraints on autocrats’ conflict behavior changes over time in three distinct periods: (1) power struggle in the early period of tenure; (2) power consolidation; and (3) power dissipation in the later period of power transition. The empirical analysis on autocratic conflict cycle reveals that the likelihood of autocratic crisis initiation significantly increases during the early years of autocratic leadership tenure, after which it moderately decreases over time. This finding suggests that autocrats’ tenure is a substantively important predictor of autocratic leaders’ conflict behavior.
Developmental Trajectories of Child Sexual Behaviors on the Path of Sexual Behavioral Problems: Evidence From a Prospective Longitudinal Study
Authors: Lussier Patrick , McCuish Evan , Mathesius Jeff , Corrado Raymond , Nadeau Danielle
Published: November 2017

There is little information about the onset and the developmental course of child sexual behavior problems (SBPs), including sexually intrusive behaviors (SIBs). Using data from the Vancouver Longitudinal Study on the Psychosocial Development of Children, the current study examined the presence of distinct patterns of sexual development among children. A normative sample of preschoolers ( N = 354) with a small clinical subsample were followed from age 3 to 8 with repetitive measurements of sexual behaviors using a revised version of Child Sexual Behavior Inventory. Semiparametric group-based modeling identified four distinct sexual development trajectories: the very low (10.5%), the low declining (27.8%), the moderate stable (48.3%), and the high-rate increasing (13.4%). In contrast to the other developmental trajectories found, the high-rate-increasing pattern showed that sexual behaviors became increasingly extensive after school entry. Children characterized by this developmental pattern, especially boys, were more likely to be involved in SIBs after elementary school entry than those in the other groups. Findings highlight the presence of multiple developmental trajectories of sexual development with significantly different behavioral patterns after school entry.
The infrastructural power of the military: The geoeconomic role of the US Army Corps of Engineers in the Arabian Peninsula
Authors: Khalili Laleh
Published: November 2017

In analysing the role of the US in the global expansion of capitalist relations, most critical accounts see the US military’s invasion and conquest of various states as paving the way for the arrival of US businesses and capitalist relations. However, beyond this somewhat simplified image, and even in peacetime, the US military has been a major geoeconomic actor that has wielded its infrastructural power via its US Army Corps of Engineers’ overseas activities. The transformation of global economies in the 20th century has depended on the capitalisation of the newly independent states and the consolidation of liberal capitalist relations in the subsequent decades. The US Army Corps of Engineers has not only extended lucrative contracts to private firms (based not only in the US and host country, but also in geopolitically allied states), but also, and perhaps most important, has itself established a grammar of capitalist relations. It has done so by forging both physical infrastructures (roads, ports, utilities and telecommunications infrastructures) and virtual capitalist infrastructures through its practices of contracting, purchasing, design, accounting, regulatory processes and specific regimes of labour and private property ownership.
“Whatever Happened to Predictability?”: Fuller House, (Post)Feminism, and the Revival of Family-Friendly Viewing
Authors: Loock Kathleen
Published: November 2017

This article examines the Netflix revival of Full House, the family sitcom about three single men raising three girls that was part of the family-friendly “TGIF” (Thank Goodness It’s Funny) lineup ABC aired on Friday nights in the 1980s and 1990s. The 2016 release of Fuller House, I argue, was driven not only by the possibility to exploit an existing property with ongoing media and cultural presence in times of “peak TV” but also by Netflix’s strategic efforts to revive the bygone days of TGIF-style programming and reinvent family-friendly viewing in the era of complex television and online streaming platforms. In analyzing the Full House revival—its production and reception contexts, its carefully crafted text and paratexts, its position among complex dramas and edgy sitcoms—I will also trace the ways in which Fuller House engages in postfeminist discourse and raises pertinent questions about family values, gender roles, and ethnic diversity.
The Burdens of Offering: Ethical and Practical Considerations
Authors: Kirsch Roxanne E. , Coronado Jillian , Roeleveld Peter P. , Tweddell James , Mott Antonio M. , Roth Stephen J.
Published: November 2017

We reflect upon highlights of a facilitated panel discussion from the 2016 Pediatric Cardiac Intensive Care Society Meeting. The session was designed to explore challenges, share practical clinical experiences, and review ethical underpinnings surrounding decisions to offer intensive, invasive therapies to patients who have a poor prognosis for survival or are likely to be burdened with multiple residual comorbidities if survival is achieved. The discussion panel was representative of a variety of disciplines including pediatric cardiology, cardiac intensive care, nursing, and cardiovascular surgery as well as different health-care delivery systems. Key issues discussed included patient’s best interests, physician obligations, moral distress, and communication in the context of decisions about providing therapy for patients with a poor prognosis.
Tricuspid Valve Repair in Infancy Using Neochordae: Three-Dimensional Echocardiographic Imaging
Authors: Martin Billie-Jean , Khoo Nee S. , Smallhorn Jeffrey , Aklabi Mohammed Al
Published: November 2017

Tricuspid regurgitation (TR) in infancy poses a surgical challenge. Both two- and three-dimensional echocardiography (3DE) can provide detailed information about the mechanism(s) of valve failure and insights into valve adaptation during follow-up. We report two patients who underwent tricuspid valve repair using Gore-Tex neochordae, repairs which were facilitated by and assessed with 3DE. Both infants had less than mild residual TR and no valve tethering at hospital discharge. Furthermore, follow-up 3DEs have helped to confirm valve competence, lack of tethering, and growth of the valve and valve apparatus.