bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential effects of land cover change on temperature extremes over Eurasia: current versus historical experiments
Authors: Li Xing , Chen Haishan , Liao Hong , Hua Wenjian , Sun Shanlei , Ma Hedi , Li Xiao , Gao Chujie , Zhu Siguang
Published: January 2017

Land use and land cover change (LUCC) is an important external forcing agent of climate change. The comparison of current (2000 A.D.) with historical (1850 A.D.) land cover maps suggests that most of the Eurasian continent has experienced robust and significant LUCC during the past century, especially evident transition from forests to croplands. Therefore, two experiments (control and sensitivity experiments with current and historical land cover maps, respectively) are conducted by using the Community Atmosphere Model Version 5.0 (CAM5.0) coupled with the Community Land Model Version 4.0 (CLM4.0) to investigate the potential effects of LUCC on temperature extremes over Eurasia. Results show significant increases (e.g., 0.2–0.7 °C) in extreme cold indices (e.g., TNn) over central and eastern China, India and mainland Southeast Asia in response to such robust LUCC. Broad and significant decreases (e.g., approximately −1 °C) in extreme warm indices (TXx) are mainly observed in Eastern Europe and western Siberia. Moreover, the effects of LUCC on high and low‐percentile extreme indices of minimum temperature (Tmin) are generally symmetrical, but those for maximum temperature (Tmax) indices are asymmetrical, which are characterized by stronger influences on high‐percentile indices rather than low ones. Further analyses suggest that LUCC‐induced changes in temperature extremes are mostly influenced by shifts in the mean state of Tmin/Tmax. Furthermore, the responses and sensitivities of Tmin/Tmax to LUCC are remarkably distinct among regions. This result mainly occurs because of different LUCC‐induced changes in surface energy components, which depend on the region‐specific climatology of each energy component and the dominant plant functional types.
Potential impacts of solar arrays on regional climate and on array efficiency
Authors: Nguyen Kim C. , Katzfey Jack J. , Riedl John , Troccoli Alberto
Published: January 2017

World population and industrialization have increased significantly, leading to an increase in global energy demand, mainly relying on fossil fuels. Use of alternative energy sources such as wind, hydro and solar has been steadily increasing. Australia is a vast continent which receives an average 58 million PJ of energy from the sun annually. Given this resource potential, one could envisage construction of massive solar farms to help meet energy demands. If such constructions went ahead, their potential benefits/impacts on the climate over and surrounding the solar arrays would need to be investigated. Here, we study the potential climatic impacts over and in the environment surrounding massive hypothetical solar sites across Australia using a global stretched grid atmospheric model. The solar farms are represented by modelling the effects of perturbing surface albedo and surface roughness. The sensitivity experiments incorporate different combinations of surface albedos, shapes and locations of the solar farms, with a focus on the summer season. Our study suggests that depending on array sizes, locations, orientations and surface albedo (potentially increased by means of highly reflective in‐fill material), the climate over solar arrays could be modified significantly. Over the arrays with positive albedo perturbation, rainfall would decrease by around 30–70%, and daytime maximum air temperatures would decrease up to 10 °C. In addition, solar irradiance would increase by around 5–20%, which combined with the air temperature cooling, would lead to an enhanced solar power yield up to 25%.
How Do Service Quality, Experiences and Enduring Involvement Influence Tourists' Behavior? An Empirical Study in the Picasso and Miró Museums in Barcelona
Authors: Forgas‐Coll Santiago , Palau‐Saumell Ramon , Matute Jorge , Tárrega Salomé
Published: January 2017

This study develops an integrated model that examines how service quality, perceived experiences and enduring involvement determine tourists' behavior. The model proposes that enduring involvement has both a direct and moderating influence on tourists' satisfaction with the destination. Data were collected from 1091 visitors of two museums in Barcelona: the Picasso Museum and the Miró Foundation. The results suggest that visit experience, service quality and involvement are drivers of satisfaction. Satisfaction influences the behavioral intentions of visitors to the museum. In addition, the visitors' level of art involvement negatively moderates the influence of perceived quality and experience on tourists' satisfaction. Copyright © 2017 John Wiley & Sons, Ltd.
Hepatic ischemia/reperfusion injury associates with acute kidney injury in liver transplantation: Prospective cohort study
Authors: Jochmans Ina , Meurisse Nicolas , Neyrinck Arne , Verhaegen Marleen , Monbaliu Diethard , Pirenne Jacques
Published: January 2017

Solid clinical prospective studies investigating the association between hepatic ischemia/reperfusion injury (HIRI) and acute kidney injury (AKI) after liver transplantation are missing. HIRI, reflected by transaminase release, induces AKI in rodents, and retrospective studies suggest a similar association in humans. This prospective cohort study determined risk factors for AKI in 80 adult liver‐only recipients. AKI defined by Risk, Injury, Failure, Loss, and End‐Stage Kidney Disease (RIFLE) criteria developed in 21 (26%) recipients at 12 hours after reperfusion (interquartile range, 6 hours to postoperative day [POD] 1); 13 progressed from “risk” to “injury”; 5 progressed to “failure.” In AKI patients, creatinine (Cr) increased during liver transplantation and was higher versus baseline at 6 hours to POD 4, whereas perioperative Cr remained stable in those without AKI. Plasma heart‐type fatty acid–binding protein was higher 12 hours after reperfusion in AKI patients, though urinary kidney injury molecule 1 and neutrophil gelatinase–associated lipocalin were similar between those with or without AKI. Peak aspartate aminotransferase (AST), occurring at 6 hours, was the only independent risk factor for AKI (adjusted odds ratio, 2.42; 95% confidence interval, 1.24‐4.91). Early allograft dysfunction occurred more frequently in AKI patients, and intensive care and hospital stays were longer. Patient survival at 1 year was 90% in those with AKI versus 98% in those without AKI. Chronic kidney disease stage ≥ 2 at 1 year was more frequent in patients who had had AKI (89% versus 58%, respectively). In conclusion, AKI is initiated early after liver reperfusion and its association with peak AST suggests HIRI as a determinant. Identifying operating mechanisms is critical to target interventions and to reduce associated morbidity. Liver Transplantation 23 634–644 2017 AASLD.
Dynamical behavior of systems of two phytoplankton and one zooplankton populations with toxin producing phytoplankton
Authors: De Silva Mihiri , Jang Sophia R.‐J.
Published: January 2017

Three‐compartment mathematical models of non‐toxic phytoplankton (NTP), toxin producing phytoplankton (TPP), and zooplankton are proposed to explore the role of TPP in algal blooms. The mutual interference between predator zooplankton and avoidance of TPP by zooplankton are incorporated into the model. The NTP and TPP engage in exploit competition and the toxin produced by TPP has no effect on NTP. Using the concept of uniform persistence, we establish coexistence of NTP, TPP, and zooplankton in certain parameter regimes. We study the effects of mutual interference and avoidance by zooplankton upon the population interactions. In addition to the toxin producing mechanism, it is concluded that mutual interference of zooplankton is an important factor for diminishing harmful blooms. Copyright © 2017 John Wiley & Sons, Ltd.
Global bifurcations and single‐pulse homoclinic orbits of a plate subjected to the transverse and in‐plane excitations
Authors: Zhang Dongmei , Chen Fangqi
Published: January 2017

The Shilnikov‐type single‐pulse homoclinic orbits and chaotic dynamics of a simply supported truss core sandwich plate subjected to the transverse and the in‐plane excitations are investigated in detail. The resonant case considered here is principal parametric resonance and 1:2 internal resonance. Based on the normal form theory, the desired form for the global perturbation method is obtained. By using the global perturbation method developed by Kovacic and Wiggins, explicit sufficient conditions for the existence of a Shilnikov‐type homoclinic orbit are obtained, which implies that chaotic motions may occur for this class of truss core sandwich plate in the sense of Smale horseshoes. Numerical results obtained by using the fourth‐order Runge–Kutta method agree with theoretical analysis at least qualitatively. Copyright © 2017 John Wiley & Sons, Ltd.
MHD Stokes flow and heat transfer in a lid‐driven square cavity under horizontal magnetic field
Authors: Gürbüz Merve , Tezer‐Sezgin M.
Published: January 2017

This study considers the steady flow of a viscous, incompressible and electrically conducting fluid in a lid‐driven square cavity under the effect of a uniform horizontally applied magnetic field. The governing equations are obtained from the Navier‐Stokes equations including buoyancy and Lorentz force terms and the energy equation including Joule heating and viscous dissipation terms. These equations are solved iteratively in terms of velocity components, stream function, vorticity, temperature, and pressure by using radial basis function approximation. Particular solution, which is approximated by radial basis functions to satisfy both differential equation and boundary conditions, becomes the solution of the differential equation itself. Vorticity boundary conditions are obtained from stream function equation using finite difference scheme. Normal derivative of pressure is taken as zero on the boundary. The numerical results are obtained for several values of Hartmann number and Grashof number for the Stokes approximation (Re << 1). The results show that when the viscous dissipation is present, the flow and isolines concentrate through the cold wall forming boundary layers as Grashof number increases. An increase in the magnetic field intensity retards the effect of buoyancy force in the square cavity, whereas the movement of the upper lid causes buoyancy force to be dominant. The solution is obtained in a considerably low computational expense through the use of radial basis function approximations for the MHD equations. Copyright © 2017 John Wiley & Sons, Ltd.
An axial‐ratio beam‐width enhancement of patch‐slot antenna based on EBG
Authors: Ke Wang Zhao , Yuan Bo , Zhang Xiao Hong , Luo Guo Qing
Published: January 2017

A low‐profile axial‐ratio beam‐width enhancement of patch‐slot antenna based on electromagnetic band gap (EBG) structure is proposed. To achieve the circularly polarized property, a diagonal slot is etched in the center of the radiation patch. The traditional mushroom‐like EBG unit cells around the patch are used to suppress the surface wave and improve the front to back ratio. This proposed antenna is printed on the FR4 substrate and fed by a single, conventional coaxial cable with 50 Ω impedance. Measured results show that the impedance bandwidth and 3‐dB axial ratio bandwidth of proposed antenna are 128 and 30 MHz, respectively. By using EBG unit cells, the 3‐dB AR beam‐width can be extended to 232.5° at x–z plane and 258° at y–z plane. The front to back ratio of the antenna is also improved to 25 dB. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:493–497, 2017
A low profile planar MIMO antenna with polarization diversity for LTE 1800/1900 applications
Authors: Malviya Leeladhar , Panigrahi R.K. , Kartikeyan M.V.
Published: January 2017

A four port MIMO antenna is proposed with polarization diversity technique to cover LTE 1800/1900 frequency standards. The antenna operates with a 2:1VSWR bandwidth of 560 MHz. The design covers −10 dB impedance band of 1.68–2.24 GHz. The minimum isolation measured among the adjacent and diagonal ports is 13 dB. The antenna offers suitable radiating characteristics for nonline of sight (NLOS) communication to solve the problem of multipath propagation. The gain of the MIMO is more than 3.0 dBi and ECC is less than 0.01 in the whole operating band. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:533–538, 2017
Parametric study of the complementary rose curve resonators (CRCRs) in miniaturization of the transmission lines
Authors: Savitri Betty , Alavikia Babak , Talbi Larbi , Hettak Khelifa
Published: January 2017

In this work, a parametric study of the complementary rose‐curve inclusion in size reduction applications is presented. Through numerical analysis and experimental data, we show the feasibility of controlling the electrical length and thus the physical length of the loaded transmission line by controlling the distributed capacitance of the rose‐curve resonators through their order. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:538–541, 2017
Reflective phase shifter based on wideband multi‐section hybrid coupler in slot‐coupled structure
Authors: Khajepour Somayeh , Asadi Shahrooz , Moradi Gholamreza
Published: January 2017

This article presents a novel reflective phase shifter based on wideband multi‐section 3‐dB hybrid coupler in slot‐coupled structure. By terminating coupled and transmission ports of coupler with rectangular microstrip loads, reflective phase shifter is achieved. It designed on multilayer Rogers RO4003C substrate. The configuration consists of elliptically shaped transmission line and the combination of rectangular and elliptical shaped slots on the ground plane. To improve characteristics of the designed coupler especially in lower frequency band, multi‐section transmission line and altering shape of the slot on ground is proposed. By etching extra rectangular slots on the ground plane the overall size reduction is achieved. Measurement results of the proposed coupler demonstrate coupling of 3 ± 0.7 dB with 90° ± 0.6 phase shift over 1–6 GHz (143%). The novel reflective phase shifter based on the designed coupler provides phase deviation less than 0.7° on 1.2–4.8 GHz (120%). The obtained return loss is better than 10 dB as well as insertion loss is less than 1.2 dB at the frequency band of interest. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:567–573, 2017
Wide‐band dual‐mode bandpass filter using a modified square‐loop resonator
Authors: Chen Hui , Chen Ke‐Song , Chen Xu
Published: January 2017

A novel and compact microstrip dual‐mode bandpass filter with multi‐transmission zeros is designed, fabricated, and measured in this letter. The presented filter consists of a modified square‐loop resonator (MSLR) with dual‐mode resonant characteristic and an improved input/output defected microstrip structure with a dual‐bandgap feature, which is overlapped with the MSLR at the input/output tapping location. Finally, a planar wideband filter with low insertion loss and high selectivity is simulated by the full‐wave electromagnetism solver, and verified by our circuit experiment. The measured results of proposed filter have agreed well with the simulated ones, and have shown an excellent electric characteristic with −3 dB fractional bandwidth 33.9% at the mid‐band frequency, minimum insertion loss 0.5 dB, maximum return loss better than −20 dB, and four transmission zeros nearby the lower and upper pass‐band edges. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:618–621, 2017
A 6‐GHz spread spectrum clock generation with EMI reduction of 30.2 dB for SATA‐III applications
Authors: Alsuraisry Hamed , Cheng Jen‐Hao , Lin Jian‐An , Kuo Yen‐Hong , Tsai Jeng‐Han , Huang Tian‐Wei
Published: January 2017

In this letter, a 6‐GHz spread spectrum clock generation for Serial AT Attachment Generation 3 (SATA—III) applications in 0.18‐pm CMOS technology is presented. The 3rd‐order loop filter is to reduce the ripple of control voltage of VCO and the loop bandwidth is 625 KHz. With the aid of second‐order delta‐sigma (ΔΣ) modulator and triangular profile counter, the division ratio of divider chain can be changed periodically. The modulation frequency is 37.04 KHz with upper bound of 19 for the triangular profile counter. The proposed circuit spreads 30‐MHz frequency range from 5.97 to 6.0 GHz with an EMI reduction of 20.3 dB. The dc power consumption is 34 mW with a chip size of 0.54 mm2. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:622–624, 2017
Compact planar microstrip branch‐line coupler using equal difference structure
Authors: Chen Ja‐Hao , Yuan Shih‐Yi , Liou Shi‐Rong , Liao Shry‐Sann
Published: January 2017

A compact planar microstrip branch‐line coupler using equal difference structures was implemented and measured. Using the equal difference structure effectively reduced the quarter‐wavelength microstrip line and minimized the branch‐line coupler dimension as a result of a novel triangular profile of the structure streamlining the circuit area. Compared with that of conventional planar microstrip branch‐line couplers, the optimized area of the proposed coupler was reduced by 84.2% at a 900 MHz operating frequency. The measured insertion loss, isolation, and return loss performances achieved superior results than 3.9, 23, and 16 dB, respectively, and the measured phase difference between the two output ports was 90° ± 0.1°. Notably, a coupler using equal difference structures can be implemented in standard printed circuit board processes without any lumped elements, bonding wires, or via‐holes, easing integration with wireless communication systems. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:664–668, 2017
A dual band stacked aperture coupled antenna array for WLAN applications
Authors: Agarwal Ayushi , Kaur Amanpreet
Published: January 2017

In this article, a dual band stacked micostrip antenna array is presented for wireless local area network. The antenna is designed and simulated using CST MWSv’14. Stacking of the patches is done to achieve dual band. Further resonant slots are cut on the patch to achieve greater bandwidth. The antenna uses aperture coupled feed with defected ground structure on reduced ground. The antenna is fabricated on FR4 substrate with a dielectric constant of 4.4. The simulated antenna shows a bandwidth of 228.3 MHz from 3.63 to 3.86 GHz and 232 MHz from 5.15 to 5.38 GHz. The simulated gain and envelope correlation coefficient was found to be 6.11 dB and 0.14. The testing of the prototype antenna (to measure S11) is done using vector network analyser. The measured results are matching to the simulated ones. The simulated and the measured results are presented in the article. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:648–654, 2017
Analytical and experimental study of the hexagonal metamaterial based on the distributions of the fields
Authors: Zhang JiaKai , Song YiChuan , Ding Jun , Guo ChenJiang
Published: January 2017

In this article, a simple hexagonal metamaterial is presented. Different from the design method of parameters optimization, the method based on the analysis of the distributions of the electric field, magnetic field, and the surface current distribution is proposed. For verification of proposed analytic method, the retrieval process is carried out. Besides, the situations of the other two frequencies point are studied to further verify the analytic method. The experimental study is introduced as well. The results show that the negative effective permittivity and the negative effective permeability with pass band character is achieved simultaneously in the frequency range between 9.58 GHz to 9.75 GHz, and the comparison between the result of the analysis and the experiment justifies the proposed analytic method. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:720–726, 2017
Employing Two‐stage Derivatisation and GC–MS to Assay for Cathine and Related Stimulant Alkaloids across the Celastraceae
Authors: Tembrock Luke R. , Broeckling Corey D. , Heuberger Adam L. , Simmons Mark P. , Stermitz Frank R. , Uvarov Jessica M.
Published: January 2017

Introduction

Catha edulis (qat, khat, mirra) is a woody plant species that is grown and consumed in East Africa and Yemen for its stimulant alkaloids cathinone, cathine and norephedrine. Two Celastraceae species, in addition to qat, have been noted for their stimulant properties in ethnobotanical literature. Recent phylogenetic reconstructions place four genera in a clade sister to Catha edulis, and these genera are primary candidates to search for cathine and related alkaloids.

Objective

Determine if cathine or related alkaloids are present in species of Celastraceae other than Catha edulis.

Methods

Leaf samples from 43 Celastraceae species were extracted in water followed by basification of the aqueous extract and partitioning with methyl‐t‐butyl ether to provide an alkaloid‐enriched fraction. The extract was derivatised in a two‐stage process and analysed using GC–MS for the presence of cathine. Related alkaloids and other metabolites in this alkaloid‐enriched fraction were tentatively identified.

Results

Cathinone, cathine and norephedrine were not detected in any of the 43 Celastraceae species assayed other than Catha edulis. However, the phenylalanine‐ or tyrosine‐derived alkaloid phenylethylamine was identified in five species. Nine species were found to be enriched for numerous sterol‐ and terpene‐like compounds.

Conclusion

These results indicate that cathine is unique to Catha edulis, and not the compound responsible for the stimulant properties reported in related Celastraceae species. Copyright © 2017 John Wiley & Sons, Ltd.
Synthesis of Quercetin‐imprinted Polymer Spherical Particles with Improved Ability to Capture Quercetin Analogues
Authors: Pardo Antonelle , Josse Thomas , Mespouille Laetitia , Blankert Bertrand , Dubois Philippe , Duez Pierre
Published: January 2017

Introduction

Molecularly imprinted polymers (MIPs) are composed of specific cavities able to selectively recognise a template molecule. Used as chromatographic sorbents, MIPs may not trap related structures due to the high rigidity of their cross‐linking.

Objective

To improve the capture of quercetin analogues by modulating the synthesis strategy for a quercetin‐imprinted polymer (Qu MIP).

Methodology

An additional comonomer bearing a short oligoethylene glycol (OEG) unit was used to prepare a Qu MIP that was compared to a traditional one formulated in a similar fashion, but without the OEG‐comonomer. The Qu MIPs were prepared in bead form through fluorocarbon suspension polymerisation. After solid phase extraction (SPE) assessment of their imprinted cavities, the MIPs were evaluated by HPLC for their recognition properties towards quercetin and other polyphenols, including flavonoids, phenolic acids and curcumin. The Qu MIPs were finally SPE‐tested on a white onion extract.

Results

The incorporation of OEG units modulated the selectivity of the Qu MIP by improving the recognition of quercetin related structures (12–61% increase in the imprinting effect for distant analogues). It also allowed limiting or suppressing non‐specific hydrophobic interactions (decrease of about 10% in the rate of quercetin retention on the non‐imprinted polymer). The SPE application of the MIP to a white onion extract indicates its interest for the selective extraction of quercetin and its analogues.

Conclusion

The OEG‐modified Qu MIP appears to be an attractive tool to discover new drug candidates from natural sources by extracting, amongst interfering compounds, structural analogues of quercetin. Copyright © 2017 John Wiley & Sons, Ltd.
Longitudinal impairment of lung function in school‐age children with extremely low birth weights
Authors: Hirata Katsuya , Nishihara Masahiro , Kimura Takeshi , Shiraishi Jun , Hirano Shinya , Kitajima Hiroyuki , Fujimura Masanori
Published: January 2017

OBJECTIVES

To assess lung function and long‐term respiratory outcomes in extremely low birth weight (ELBW) survivors.

WORKING HYPOTHESIS

ELBW, especially with respiratory complications in the neonatal period, affects lung function at a later age.

STUDY DESIGN

Longitudinal retrospective study.

PATIENT‐SUBJECT SELECTION

Lung function was evaluated in 89 ELBW survivors (at ages 8 and 12) with or without a history of bronchopulmonary dysplasia (BPD) or a bubbly/cystic lung appearance in the neonatal period.

METHODOLOGY

FVC, FEV1, FEF50, and FEF75 were measured using spirometry. Two‐way repeated‐measures ANOVA was used to compare lung function and deterioration time course from 8 to 12 years of age.

RESULTS

Lung function variables were significantly and positively correlated between 8 and 12 years: %FVC (R2 = 0.558), %FEV1 (R2 = 0.539), %FEF50 (R2 = 0.412), and %FEF75 (R2 = 0.429). Lung function values were lower than Japanese reference values, especially in children with a history of severe BPD or a bubbly/cystic appearance. %FEV1 and FEV1/FVC ratio worsened from 8 to 12 years of age: 83.0 ± 17.0% versus 76.6 ± 17.8% (mean difference, 95%CI: −6.43, −9.10 to −3.75) and 84.0 ± 10.1% versus 78.2 ± 13.4% (mean difference, 95%CI: −5.82, −8.56 to −3.08), regardless of whether or not there was a history of neonatal respiratory disease.

CONCLUSIONS

In ELBW survivors, the obstructive pattern of lung function impairment deteriorated from 8 to 12 years of age, independent of the presence of severe BPD or bubbly/cystic appearance in the neonatal period.
Chest physiotherapy can affect the lung clearance index in cystic fibrosis patients
Authors: Grosse‐Onnebrink Joerg , Mellies Uwe , Olivier Margarete , Werner Claudius , Stehling Florian
Published: January 2017

OBJECTIVES

The lung clearance index (LCI) is determined by multiple‐breath washout lung function (MBW). It is increasingly used as an endpoint in clinical trials. Chest physiotherapy (CP) is part of routine cystic fibrosis (CF) care. Whether the LCI is useful in detecting short‐term treatment effects of CP has not been sufficiently investigated. We assessed the short‐term influence of CP with highly standardized high‐frequency chest wall oscillation (HFCWO) on the LCI in CF patients.

METHODS

In this randomized controlled study, the LCI was obtained in 20 CF patients (7‐34 years) hospitalized for infective pulmonary exacerbation prior to and immediately after a single treatment of HFCWO. Twenty‐one control group CF patients (7‐51 years) received no treatment. We calculated the coefficient of repeatability (CR) to estimate the clinical relevance of possible treatment effects.

RESULTS

HFCWO improved (ie, decreased) the LCI by a median of 0.9 (range −0.45; 3.47; P = 0.002); the LCI decreased in 15 of 20 intervention group patients. In five patients the decrease in LCI exceeded the CR (2.15), indicating a clinically relevant treatment effect; in five patients the LCI increased but did not exceed the CR. The LCI did not change significantly in the control group patients.

CONCLUSIONS

HFCWO can have a short‐term decreasing effect on the LCI, but the treatment response is heterogeneous. In future trials using LCI as an endpoint, the timing of CP in relation to MBW should be considered a possible bias.
Evaluation and Social Research
Authors: Hall Irene , Hall David
Published: January 2017

Evaluation is a large and growing field with applications to a wide range of disciplines – including sociology, social work, social policy, psychology, health, nursing, education, community development, etc. This text explains the different perspectives and needs of researchers and practitioners at the local level in plain, accessible English and develops a model for small scale evaluation. It offers a practical approach to the challenges of evaluation research, well illustrated with examples, and suitable for students and practitioners alike.
Academic time during college: Associations with mood, tiredness, and binge drinking across days and semesters
Authors: Greene Kaylin M. , Maggs Jennifer L.
Published: January 2017

The current study examined the amount of time American college students spent on academics and explored whether functioning indicators (i.e., positive affect, negative affect, tiredness, and binge drinking) rose and fell with academic time across days and semesters. College students (N= 735) were followed longitudinally and completed 14 daily diaries within each of 7 semesters (N= 56,699 days). The results revealed that academic time decreased slightly during the middle semesters and then increased in later semesters. Furthermore, on days when students spent more time on academics, they reported less positive affect, more tiredness, and less binge drinking; however, the strength and direction of associations depended on the analysis level and whether it was a weekend. Positive affect, for instance, was inversely associated with academics across days, but the reverse was true across semesters. These results emphasize the importance of considering the temporal context in research on adolescent and young adult time use.
Posterior Reversible Encephalopathy Syndrome: A Review
Authors: Shankar Jai , Banfield Jillian
Published: January 2017

Radiologists may be the first to suggest the diagnosis of posterior reversible encephalopathy syndrome (PRES). PRES is associated with many diverse clinical entities, the most common of which are eclampsia, hypertension, and immunosuppressive treatment. Radiologists should be aware of the spectrum of imaging findings in PRES. When promptly recognized and treated, the symptoms and radiological abnormalities can be completely reversed. When unrecognized, patients can progress to ischemia, massive infarction, and death. In this review, we present an overview of the unique signs observed on computed tomography and magnetic resonance images in PRES that can help in the early diagnosis and treatment that is highly effective in this syndrome.
Diffusion-Weighted Imaging of the Brain: Beyond Stroke
Authors: Dmytriw Adam A. , Sawlani Vijay , Shankar Jai
Published: January 2017

Diffusion-weighted imaging provides image contrast that is different from that provided by conventional magnetic resonance imaging techniques. It is highly sensitive for detection of cytotoxic oedema, and as such has gained favor in the detection of acute infarcts. However, diffusion-weighted imaging is underrepresented in the characterisation of many other disease processes. Our objective is to differentiate diseases that manifest with various neurological disorders, based on diffusion contrast and apparent diffusion coefficient values and review of hyper- and hypointense lesions on diffusion-weighted imaging.
One more time, it is not about cost!
Authors: Ketokivi Mikko
Published: January 2017

In this JOM Forum article, published in conjunction with the Special Issue on Manufacturing in the High‐Cost Environment, two operations management heavyweights Richard Schonberger and Karen Brown examine the missing link between manufacturing research and practice.
On reduced models for gravity waves generated by moving bodies
Authors: Trinh Philippe H.
Published: January 2017

In 1983, Tulin published a report proposing a framework for reducing the equations for gravity waves generated by moving bodies into a single nonlinear differential equation solvable in closed form (Proceedings of the 14th Symposium on Naval Hydrodynamics, 1983, pp. 19–51). Several new and puzzling issues were highlighted by Tulin, notably the existence of weak and strong wave-making regimes, and the paradoxical fact that the theory seemed to be applicable to flows at low speeds, ‘but not too low speeds’. These important issues were left unanswered, and despite the novelty of the ideas, Tulin’s report fell into relative obscurity. Now, 30 years later, we will revive Tulin’s observations, and explain how an asymptotically consistent framework allows us to address these concerns. Most notably, we demonstrate, using the asymptotic method of steepest descents, how the production of free-surface waves can be related to the arrangement of integration contours connected to the shape of the moving body. This approach provides a new and powerful methodology for the study of geometrically nonlinear wave–body interactions.
Experimental study of oscillating-grid turbulence interacting with a solid boundary
Authors: McCorquodale Mark W. , Munro R. J.
Published: January 2017

The interaction between oscillating-grid turbulence and a solid, impermeable boundary (positioned below, and aligned parallel to, the grid) is studied experimentally. Instantaneous velocity measurements, obtained using two-dimensional particle imaging velocimetry in the vertical plane through the centre of the (horizontal) grid, are used to study the effect of the boundary on the root-mean-square velocity components, the vertical flux of turbulent kinetic energy (TKE) and the terms in the Reynolds stress transport equation. Identified as a critical aspect of the interaction is the blocking of a vertical flux of TKE across the boundary-affected region. Terms of the Reynolds stress transport equations show that the blocking of this energy flux acts to increase the boundary-tangential turbulent velocity component, relative to the far-field trend, but not the boundary-normal velocity component. The results are compared with previous studies of the interaction between zero-mean-shear turbulence and a solid boundary. In particular, the data reported here are in support of viscous and ‘return-to-isotropy’ mechanisms governing the intercomponent energy transfer previously proposed, respectively, by Perot & Moin (J. Fluid Mech., vol. 295, 1995, pp. 199–227) and Walkeret al.(J. Fluid Mech., vol. 320, 1996, pp. 19–51), although we note that these mechanisms are not independent of the blocking of energy flux and draw parallels to the related model proposed by Magnaudet (J. Fluid Mech., vol. 484, 2003, pp. 167–196).
Comparison between passive scalar and velocity fields in a turbulent cylinder wake
Authors: Chen J. G. , Zhou T. M. , Antonia R. A. , Zhou Y.
Published: January 2017

This work compares the enstrophy with the scalar dissipation rate, as well as the passive scalar variance with the turbulent kinetic energy, in the presence of coherent Kármán vortices in the intermediate wake of a circular cylinder. Measurements are made at$x/d=10$, 20 and 40, where$x$is the streamwise distance from the cylinder axis and$d$is the cylinder diameter, with a Reynolds number of$2.5\times 10^{3}$based on the cylinder diameter and the free-stream velocity. A probe consisting of eight hot wires (four X-wires) and four cold wires is used to measure simultaneously the three components of the fluctuating velocity and vorticity vectors, as well as the fluctuating temperature gradient vector at nominally the same point in the plane of the mean shear. It is found that the enstrophy and scalar dissipation spectra collapse approximately at all wavenumbers except around the Kármán vortex street wavenumber for$x/d\geqslant 20$. The spectral similarity between the streamwise velocity fluctuation$u$and the passive scalar$\unicode[STIX]{x1D703}$is better than that between the velocity fluctuation vector$\boldsymbol{q}$and$\unicode[STIX]{x1D703}$. This is closely related to the highly organized lateral velocity fluctuation$v$in this flow. The present observations are fully consistent with the expectation that small scales of the velocity and temperature fields are more likely to exhibit a close relationship than scales associated with the bulk of the turbulent energy or scalar variance. The variation across the wake of the time scale ratio between scalar and velocity fields is significantly smaller than that of the turbulent Prandtl number.
Wavelet decomposition of hydrodynamic and acoustic pressures in the near field of the jet
Authors: Mancinelli Matteo , Pagliaroli Tiziano , Di Marco Alessandro , Camussi Roberto , Castelain Thomas
Published: January 2017

An experimental investigation of pressure fluctuations generated by a single-stream compressible jet is carried out in an anechoic wind tunnel. Measurements are performed using a linear array of microphones installed in the near region of the jet and a polar arc of microphones in the far field. The main focus of the paper is on the analysis of the pressure fluctuations in the near field. Three novel signal processing techniques are presented to provide the decomposition of the near-field pressure into hydrodynamic and acoustic components. The procedures are all based on the application of the wavelet transform to the measured pressure data and possess the distinctive property of requiring a very simple arrangement to obtain the desired results (one or two microphones at most). The hydrodynamic and acoustic pressures are characterized separately in terms of their spectral and statistical quantities and a direct link between the acoustic pressure extracted from the near field and the actual noise in the far field is established. The analysis of the separated pressure components sheds light on the nearly Gaussian nature/intermittent behaviour of the acoustic/hydrodynamic pressure. The higher sensitivity of the acoustic component to the Mach number variation has been highlighted as well as the different propagation velocities of the two pressure components. The achieved outcomes are validated through the application to the same data of existing separation procedures evidencing the advantages and limitations of the new methods.
Pairwise interaction extended point-particle model for a random array of monodisperse spheres
Authors: Akiki G. , Jackson T. L. , Balachandar S.
Published: January 2017

This study introduces a new point-particle force model that attempts to account for the hydrodynamic influence of the neighbouring particles in an Eulerian–Lagrangian simulation. In previous point-particle models the force on a particle depends only on Reynolds number and mean volume fraction. Thus, as long as the mean local volume fraction is the same, the force on different particles will be estimated to be the same, even though the precise arrangement of neighbours can be vastly different. From direct numerical simulation (DNS) it has been observed that in a random arrangement of spheres that were distributed with uniform probability, the particle-to-particle variation in force can be as large as the mean drag. Since the Reynolds number and mean volume fraction of all the particles within the array are the same, the standard models fail to account for the significant particle-to-particle force variation within the random array. Here, we develop a model which can compute the drag and lateral forces on each particle by accounting for the precise location of a few surrounding neighbours. A pairwise interaction is assumed where the perturbation flow induced by each neighbour is considered separately, then the effects of all neighbours are linearly superposed to obtain the total perturbation. Faxén correction is used to quantify the force perturbation due to the presence of the neighbours. The single neighbour perturbations are mapped in the vicinity of a reference sphere and stored as libraries. We test the pairwise interaction extended point-particle (PIEP) model for random arrays at two different volume fractions of $\unicode[STIX]{x1D719}=0.1$ and 0.21 and Reynolds numbers in the range $16.5\leqslant Re\leqslant 170$. The PIEP model predictions are compared against drag and lift forces obtained from the fully resolved DNS simulations performed using the immersed boundary method. Although not perfect, we observe the PIEP model prediction to correlate much better with the DNS results than the classical mean drag model prediction.
Viscoplastic boundary layers
Authors: Balmforth N. J. , Craster R. V. , Hewitt D. R. , Hormozi S. , Maleki A.
Published: January 2017

In the limit of a large yield stress, or equivalently at the initiation of motion, viscoplastic flows can develop narrow boundary layers that provide either surfaces of failure between rigid plugs, the lubrication between a plugged flow and a wall or buffers for regions of predominantly plastic deformation. Oldroyd (Proc. Camb. Phil. Soc., vol. 43, 1947, pp. 383–395) presented the first theoretical discussion of these viscoplastic boundary layers, offering an asymptotic reduction of the governing equations and a discussion of some model flow problems. However, the complicated nonlinear form of Oldroyd’s boundary-layer equations has evidently precluded further discussion of them. In the current paper, we revisit Oldroyd’s viscoplastic boundary-layer analysis and his canonical examples of a jet-like intrusion and flow past a thin plate. We also consider flow down channels with either sudden expansions or wavy walls. In all these examples, we verify that viscoplastic boundary layers form as envisioned by Oldroyd. For each example, we extract the dependence of the boundary-layer thickness and flow profiles on the dimensionless yield-stress parameter (Bingham number). We find that, while Oldroyd’s boundary-layer theory applies to free viscoplastic shear layers, it does not apply when the boundary layer is adjacent to a wall, as has been observed previously for two-dimensional flow around circular obstructions. Instead, the boundary-layer thickness scales in a different fashion with the Bingham number, as suggested by classical solutions for plane-parallel flows, lubrication theory and, for flow around a plate, by Piau (J. Non-Newtonian Fluid Mech., vol. 102, 2002, pp. 193–218); we rationalize this second scaling and provide an alternative boundary-layer theory.
Equilibrium radial positions of neutrally buoyant spherical particles over the circular cross-section in Poiseuille flow
Authors: Morita Yusuke , Itano Tomoaki , Sugihara-Seki Masako
Published: January 2017

An experimental study of the inertial migration of neutrally buoyant spherical particles suspended in the Poiseuille flow through circular tubes has been conducted at Reynolds numbers $(Re)$ from 100 to 1100 for particle-to-tube diameter ratios of ${\sim}$0.1. The distributions of particles in the tube cross-section were measured at various distances from the tube inlet and the radial probability function of particles was calculated. At relatively high $Re$, the radial probability function was found to have two peaks, corresponding to the so-called Segre–Silberberg annulus and the inner annulus, the latter of which was first reported experimentally by Matas et al. (J. Fluid Mech. vol. 515, 2004, pp. 171–195) to represent accumulation of particles at smaller radial positions than the Segre–Silberberg annulus. They assumed that the inner annulus would be an equilibrium position of particles, where the resultant lateral force on the particles disappears, similar to the Segre–Silberberg annulus. The present experimental study showed that the fraction of particles observed on the Segre–Silberberg annulus increased and the fraction on the inner annulus decreased further downstream, accompanying an outward shift of the inner annulus towards the Segre–Silberberg annulus and a decrease in its width. These results suggested that if the tubes were long enough, the inner annulus would disappear such that all particles would be focused on the Segre–Silberberg annulus for $Re<1000$. At the cross-section nearest to the tube inlet, particles were absent in the peripheral region close to the tube wall including the expected Segre–Silberberg annulus position for $Re>700$. In addition, the entry length after which radial migration has fully developed was found to increase with increasing $Re$, in contrast to the conventional estimate. These results may be related to the developing flow in the tube entrance region where the radial force profile would be different from that of the fully developed Poiseuille flow and there may not be an equilibrium position corresponding to the Segre–Silberberg annulus.
Experimental observation of viscoelastic fluid–structure interactions
Authors: Dey Anita A. , Modarres-Sadeghi Yahya , Rothstein Jonathan P.
Published: January 2017

It is well known that when a flexible or flexibly mounted structure is placed perpendicular to the flow of a Newtonian fluid, it can oscillate due to the shedding of separated vortices. Here, we show for the first time that fluid–structure interactions can also be observed when the fluid is viscoelastic. For viscoelastic fluids, a flexible structure can become unstable in the absence of fluid inertia, at infinitesimal Reynolds numbers, due to the onset of a purely elastic flow instability. Nonlinear periodic oscillations of the flexible structure are observed and found to be coupled to the time-dependent growth and decay of viscoelastic stresses in the wake of the structure.
Postprandial glycaemic response to berry nectars containing inverted sucrose
Authors: Törrönen Riitta , Hellström Jarkko , Mattila Pirjo , Kilpi Kyllikki
Published: January 2017

Sucrose is commonly used for sweetening berry products. During processing and storage of berry products containing added sucrose, sucrose is inverted to glucose and fructose. We have previously shown that postprandial glycaemic response induced by intact sucrose is attenuated when sucrose is consumed with berries rich in polyphenols. It is not known how inversion of sucrose affects glycaemic response. We investigated postprandial glycaemic and insulinaemic responses to blackcurrant (Ribes nigrum) and lingonberry (Vaccinium vitis-idaea) nectars and a reference drink (water) sweetened with glucose and fructose, representing completely inverted sucrose. The nectars and reference drink (300 ml) contained 17·5 g glucose and 17·5 g fructose. Polyphenol composition of the nectars was analysed. A total of eighteen healthy volunteers participated in a randomised, controlled, cross-over study. Blood samples were collected at fasting and six times postprandially during 120 min. Inverted sucrose in the reference drink induced glycaemic and insulinaemic responses similar to those previously observed for intact sucrose. In comparison with the reference, the blackcurrant nectar attenuated the early glycaemic response and improved glycaemic profile, and the lingonberry nectar reduced the insulinaemic response. The responses induced by inverted sucrose in the berry nectars are similar to those previously observed for berry nectars containing intact sucrose, suggesting that inversion has no major impact on glycaemic response to sucrose-sweetened berry products. The attenuated glycaemic response after the blackcurrant nectar may be explained by inhibition of intestinal absorption of glucose by blackcurrant anthocyanins.
The Seclusion of Eustochium: Paschasius Radbertus and the Nuns of Soissons
Authors: Matis Hannah W.
Published: January 2017

This article examines three works by the ninth-century theologian, Paschasius Radbertus, all addressed to the Carolingian community of religious women at Notre Dame de Soissons. In addition to being valuable sources for the Mariologist, these sources provide insights into the complex social world of Carolingian religious women. Written at the time of the implementation of the monastic reforms of Benedict of Aniane, Radbert's texts can be read as responses to the imposition of a stricter form of claustration on women's communities. Drawing on the patristic model of Jerome and Eustochium in particular, the spirituality of these texts stresses the contributions of religious women through intercessory prayer, liturgy, and correct doctrine. Radbert alternately emphasizes the important role played by widows in Carolingian religious houses and encourages younger members not to leave the shelter of the religious life. In particular, Radbert's commentary on Psalm 44 (45) meditates on a text that would have been significant at the nuns' consecrations, deliberately employing language that would have paralleled the conventions of secular marriage. In conclusion, Radbert's three texts for Carolingian nuns bear interesting resemblances to twelfth-century Cistercian spirituality.