bluuebunny/crossref_metadata_2025 huggingface dataset:
Refining a Pathogen's Genome to Know the Enemy Better for the Winning Battles
Authors: Mohammad Hazara Begum , Lee Seung‐Eun , Kim Min‐Sik
Published: March 2019

Clavibacter michiganensis, subsp. michiganens is a gram positive bacterial pathogen infecting tomato, resulting in the great losses of yield and quality worldwide. Despite its great impact on economics, we do not fully understand the virulence factors from its genome probably due to imperfect genome annotation. Peritore‐Galve et al. utilized proteogenomic approach to identify 26 novel protein‐coding regions, to extend 59 annotated open reading frames and to confirm protein expression for ≈70% of predicted gene models of Clavibacter michiganensis subsp. michiganensis. New findings by the proteogenomics technique were further confirmed using reverse transcription‐polymerase chain reaction. To win battles with pathogens, it is advantageous to know about our enemies accurately which can be achieved by mass spectrometry‐based identifications of novel protein‐coding regions in genomes.
Conformational studies of RGDechi peptide by natural‐abundance NMR spectroscopy
Authors: Farina Biancamaria , Del Gatto Annarita , Comegna Daniela , Di Gaetano Sonia , Capasso Domenica , Isernia Carla , Saviano Michele , Fattorusso Roberto , Zaccaro Laura , Russo Luigi
Published: March 2019

Integrins are heterodimeric cell‐surface proteins that play important roles during developmental and pathological processes. Diverse human pathologies involve integrin adhesion including thrombotic diseases, inflammation, tumour progression, fibrosis, and infectious diseases. Although in the past decade, novel integrin‐inhibitor drugs have been developed for integrin‐based medical applications, the structural determinants modulating integrin‐ligands recognition mechanisms are still poorly understood, reducing the number of integrin subtype exclusive antagonists. In this scenario, we have very recently showed, by means of chemical and biological assays, that a chimeric peptide (named RGDechi), containing a cyclic RGD motif linked to an echistatin C‐terminal fragment, is able to interact with the components of integrin family with variable affinities, the highest for αvβ3. Here, in order to understand the mechanistic details driving the molecular recognition mechanism of αvβ3by RGDechi, we have performed a detailed structural and dynamics characterization of the free peptide by natural abundance nuclear magnetic resonance (NMR) spectroscopy. Our data indicate that RGDechi presents in solution an heterogeneous conformational ensemble characterized by a more constrained and rigid pentacyclic ring and a largely unstructured acyclic region. Moreover, we propose that the molecular recognition of αvβ3integrin by RGDechi occurs by a combination of conformational selection and induced fit mechanisms. Finally, our study indicates that a detailed NMR characterization, by means of natural abundance15N and13C, of a mostly unstructured bioactive peptide may provide the molecular basis to get essential structural insights into the binding mechanism to the biological partner.
Zero‐Energy Vortices in Dirac Materials
Authors: Downing Charles A. , Portnoi Mikhail E.
Published: March 2019

In this brief review, the problem of electrostatic confinement of massless Dirac particles is surveyed via a number of exactly solvable one‐ and two‐body models. By considering bound states at zero energy, a route to obtain truly discrete states of massless Dirac particles in scalar potentials is presented, circumventing the celebrated Klein tunneling phenomenon. It is also shown how the coupling of two ultrarelativistic particles can arise, and its implications for cutting‐edge experiments with two‐dimensional Dirac materials are discussed. Finally, an analytic solution of the two‐body Dirac–Kepler problem is reported, which may be envisaged to bring about a deeper understanding of critical charge and atomic collapse in mesoscopic Dirac systems.
Role of package headspace on multilayer films subjected to high hydrostatic pressure
Authors: Al‐Ghamdi Saleh , Rasco Barbara , Tang Juming , Barbosa‐Cánovas Gustavo V. , Sablani Shyam S.
Published: March 2019

The objective of this study was to systematically examine the effect of high‐pressure processing and package headspace on package integrity and properties. Working pressures were 400 and 600 MPa, and starting vessel temperatures were 30°C, 60°C, and 90°C. Coextruded and laminated multilayers packaging films were studied: film A: (PA/EVOH/PP) and film B: (PET‐AlOx‐OC/PA6/PP), respectively. The films were made into pouches (0.05 m × 0.10 m) and filled with 30‐mL water as a model food. Various headspace volumes (0, 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30‐cc air/mL H2O) were introduced into the packaging before processing. Imaging was used to quantify defects such as the formation of white spots on the package surface and delamination of film layers. The results showed that the headspace level and processing initial temperature had a greater effect than the operating pressure on visual defects. The package with 0% headspace did not show any physical damage to the tested films. Furthermore, thermal and mechanical analyses showed that the coextruded film A had better resistance to testing conditions than the laminated structure of film B. The X‐ray diffraction results showed that film B had more defects than film A that altered the crystalline structure. Visual observation revealed white spots and delamination in the inside layer (PP) in both films. The same processing conditions affected the oxygen and water vapour transmission rates of film B more than film A. This work provides a basic guideline to select the right headspace for a given type of packaged food whenever heat and pressure are used simultaneously.
Vibration and acceleration levels of multimodal container shipping physical environment
Authors: Böröcz Péter
Published: March 2019

In global supply chains, multimodal transportation plays a dominant role in worldwide shipping. The rail, truck, and vessel combination is the most commonly used mode for non‐time sensitive shipments between continents. This study focused on measuring the transportation environment effects (vibration and acceleration levels) in 40‐foot ISO container shipments using multiple modes of transport, originating in Hungary and destined for Mexico, India, and China over several weeks. The study also measured multimodal shipping routes without vessel transportation to China over Trans‐Siberian and Trans‐Manchurian railway lines. The transshipments and handling events in container hubs and terminals were separately analyzed. The results show the comparison of vibration intensity (in PSD) of different route conditions between various continents, and the possibility of acceleration levels during transshipments and handling events. The measured data show that extreme acceleration levels in vertical direction (9.37 G) occur while containers are handled in a seaport, and in lateral (4.45 G) and longitudinal (5.55 G) directions while they are transshipped by truck to rail container terminals. The rail vibration levels in Russia and China showed a lower intensity in the frequency range of 1 to 15 Hz, and higher between 15 and 200 Hz than in Europe; the lowest vibration levels occurred when the containers traveled on the sea, and truck vibration levels were very similar to previous research and ISTA protocols.
Online detection of financial time series peaks and troughs: A probability‐based approach*
Authors: Bramante Riccardo , Facchinetti Silvia , Zappa Diego
Published: March 2019

The problem related to the identification of a change in time series trajectories plays a crucial role in many contexts. In this paper, we propose a flexible and computationally efficient procedure for turning point identification based on hypothesis testing applied to the difference between two consecutive slopes in a rolling regression framework. Along with the description of the methodology, to measure the performance of the method we have applied it to the S&P 500 Stock Index and its subsector indices. By using an in‐sample/out‐of‐sample approach we compare results with the profit/losses we could obtain by using the moving average crossover strategy. Results show that the operating signals obtained by our proposal may better enable financial analysts to make profitable decisions. Finally we present an extensive simulation study to show the weaknesses and strengths of the proposal under different expected returns and volatility scenarios.
Advancing the Sustainable Development Goals: Evidence from leading European banks
Authors: Avrampou Anna , Skouloudis Antonis , Iliopoulos George , Khan Nadeem
Published: March 2019

The sustainable development goals (SDGs) reflect grand challenges that the global community needs to address in order to ensure economic welfare, environmental quality, social cohesion and prosperity for future generations. In this respect, the role of the banking sector, among other critical business entities and key stakeholders, is vital. The purpose of our paper is to examine how comprehensively the reported performance of banks aligns with the endorsement of SDGs. We employ the well‐established framework of the Global Reporting Initiative (GRI) performance indicators for a comparative assessment of the nonfinancial performance disclosed in the annual sustainability reports. Focusing on a small sample of leading European banks, we find an overall low contribution to SDGs. Furthermore, each bank's contribution remains particularly heterogeneous towards most individual SDG goals. Likewise, bank‐specific strategies drive the most extensively addressed SDGs, overlooking any critical importance of certain GRI indicators with multifaceted impact across several SDGs. The study sets forth managerial implications for improving effective reporting of SDG performance. It concludes with emerging opportunities for enhancing disclosure of SDGs contribution and highlights future research perspectives towards industry‐wide shared‐value appraisal under the scope of these pressing grand challenges.
Negotiating access to water in central Mozambique: Implications for rural livelihoods
Authors: Walker Michael Madison
Published: March 2019

Access to water underpins a range of smallholder livelihood strategies. Consequently, it is the intersections of water and land use and access that structure rural livelihoods. Drawing on eighteen months of ethnographic research in the town of Sussundenga in central Mozambique, this article examines how residents differentiated by class and gender negotiate access to water under a fragmented water regime. Increasing competition for commercially valuable wetlands and stream‐bank plots is creating new exclusions from these sites that have long been central to subsistence production. While the commercialization of the town's rural water supply network also has the potential to exclude residents who are unable to pay new water users' fees, residents have been less willing to exclude poorer households from using the new infrastructure. Exploring how the commercialization of some water use produces exclusions while other forms do not, this article suggests that water's meanings and values change as it moves across the hydrosocial landscape.
Wide Identification of the Compounds in Licorice and Exploration of the Mechanism for Prostatitis Treatment by Combining UHPLC‐LTQ‐Orbitrap MS with Network Pharmacology
Authors: Li Xiuming , Liu Hui , Shao Yuanyang , Ma Guang , Song Dianbin , Xu Guojie , Wang Zhiyong
Published: March 2019

Licorice has been used as an important herbal medicine for treating chronic diseases in Asian countries for thousands of years. In this study, UHPLC‐LTQ‐Orbitrap MS was used to widely identify the compounds of licorices from Glycyrrhiza uralensis (Gu) and G. inflata (Gi) species by the methods of untargeted and targeted metabolomics and systemically predicted the mechanism in treating prostatitis. As a result, 91 compounds were successfully identified and most compounds showed remarkable difference between Gu and Gi samples. Multivariate statistics further demonstrated that the Gu samples were significantly discriminated from the Gi samples in the content level of main compounds. Interestingly, we also found that those compounds had two main accumulation patterns in licorice. Network pharmacology analysis predicted that those compounds in licorice interacted with a wide of targets in body and interrupted prostatitis by 17 key targets. This study would be of significance to the study on quality control and development of licorice‐related products and offer a scientific basis for exploring the mechanism of treating prostatitis.
Evaluation of Major Product Distribution Using Experimental‐Theoretical Comparative Studies on Toluene and Ethylbenzene Ethylation over Catalysts Zeolite MCM‐22 and Modified MCM‐22
Authors: Thakkar Riddhi , Bandyopadhyay Rajib
Published: March 2019

The activity of zeolite MCM‐22 and modified MCM‐22 catalyst were tested in the vapor phase alkylation of toluene and ethylbenzene by ethanol to investigate the influence of thermodynamic parameters, reaction temperature, and the molar ratio of toluene and ethylbenzene to ethanol. The reactions were evaluated with experimental and theoretical approaches. The catalysts were characterized by XRD, FE‐SEM, TGA, N2‐adsorption, and NH3 & Py‐TPD analyses. The superior catalytic performance of modified MCM‐22 was observed in ethylation of ethylbenzene and ethylation of toluene. The catalytic performance indicates that zeolite MCM‐22 retained shape selectivity resulting into para‐selectivity, while modified MCM‐22 possessed more mesopores and increased accessibility to the acid sites thereby increasing conversion of ethylbenzene.
Photodegradation Activity of Nitrogen‐rich Graphitic Carbon Nitride Intercalated ZnO\Mg‐Al Layered Double Hydroxide Ternary Nanocomposites on Methylene Blue Dye
Authors: Bhuvaneswari Kandasamy , Palanisamy Govindasamy , Pazhanivel Thangavelu , Maiyalagan Thandavarayan , Bharathi Ganapathi
Published: March 2019

Herein, we report the preparation and visible light‐triggered photocatalytic investigation of nitrogen‐rich graphitic carbon nitride (g‐C3N4) nanosheets intercalated ZnO\Mg−Al LDH (2D\2D) ternary nanocomposite. The ZnO nanoparticles, unique structured LDH, and g‐C3N4 are intercalated well by the hydrothermal treatment, showing a significant enhancement in the visible light absorption and corresponding photocatalytic activity. Formation of this new ternary nanocomposite was examined by using XRD, FE‐SEM, TEM, FTIR, EDX, Elemental mapping, XPS and UV‐Vis analysis. The ternary nanocomposite photocatalyst show remarkable performance towards the photodegradation of Methylene Blue (MB) dye. The ternary nanocomposite exhibited considerable improvement in the photocatalytic activity and is attributed to the N‐ rich g‐C3N4 and even distribution of ZnO\Mg−Al LDH over the g‐C3N4 surface. This work offers a facile approach to prepare a novel visible light‐ response photocatalyst for photocatalytic dye degradation of organic pollutants.
Dehydration of 1,5‐Pentanediol over ZrO2‐ZnO Mixed Oxides
Authors: Beasley Charles , Gnanamani Muthu Kumaran , Martinelli Michela , Góra‐Marek Kinga , Hamano Kaichiro , Shafer Wilson D. , Wanninayake Namal , Kim Doo Young
Published: March 2019

Zn addition was found to affect both activity and selectivity of ZrO2 for dehydration of 1,5‐pentanediol. ZrO2 tends to produce more or less equimolar mixture of tetrahydropyran (THP) derivatives and 4‐penten‐1‐ol from 1,5‐pentanediol. The conversion of 1,5‐pentanediol on ZrO2 increases with increasing Zn content up to 30–50 mole percent; however, catalyst containing Zn beyond 50 mole percent had an adverse effect on both conversion of diol and the selectivity for unsaturated alcohol (i. e., 4‐penten‐1‐ol). XRD and Raman analysis infer that the presence of tetragonal ZrO2, the amorphous phase (ZrO2, ZrZnOx, ZnO), and hexagonal wurtzite structure of ZnO in the catalysts. The interplanar spacing of ZrO2 (111) and ZnO (100) planes for catalysts indicate that Zn incorporates into ZrO2 lattice and vice‐versa. Basicity assessed from CO2‐TPD and acidity from FTIR‐pyridine adsorption techniques indicate that both basicity and Lewis acid sites density increases with increasing Zn proportion on ZrO2 up to 50:50 molar ratios of Zn to Zr. An optimum Zn:Zr mole ratio is required to achieve higher density of oxygen vacant metal sites (i. e., Lewis acidity) and balanced acid‐base strength which improves the diol conversion.
Metal–Organic Frameworks and Their Derived Materials: Emerging Catalysts for a Sulfate Radicals‐Based Advanced Oxidation Process in Water Purification
Authors: Wang Chaohai , Kim Jeonghun , Malgras Victor , Na Jongbeom , Lin Jianjian , You Jungmok , Zhang Ming , Li Jiansheng , Yamauchi Yusuke
Published: March 2019

With the ever‐growing environmental issues, sulfate radical (SO4•−)‐based advanced oxidation processes (SR‐AOPs) have been attracting widespread attention due to their high selectivity and oxidative potential in water purification. Among various methods generating SO4•−, employing heterogeneous catalysts for activation of peroxymonosulfate or persulfate has been demonstrated as an effective strategy. Therefore, the future advances of SR‐AOPs depend on the development of adequate catalysts with high activity and stability. Metal–organic frameworks (MOFs) with large surface area, ultrahigh porosity, and diversity of material design have been extensively used in heterogeneous catalysts, and more recently, enormous effort has been made to utilize MOFs‐based materials for SR‐AOPs applications. In this work, the state‐of‐the‐art research on pristine MOFs, MOFs composites, and their derivatives, such as oxides, metal/carbon hybrids, and carbon materials for SR‐AOPs, is summarized. The mechanisms, including radical and nonradical pathways, are also detailed in the discussion. This work will hopefully promote the future development of MOFs‐based materials toward SR‐AOPs applications.
Investigation of the Effects of Al2O3 Content and Cooling Rate on Crystallization in Fe2O3–CaO–Al2O3 System Using In Situ Confocal Laser Scanning Microscopy
Authors: Park Tae Jun , Choi Joon Sung , Min Dong Joon
Published: March 2019

Sinter is a major Fe source, that is, used extensively in blast furnace processes worldwide. The chemical and physical properties of sinter are crucial factors that affect the operating stability of blast furnaces. The quality of sinter is largely determined by the phase fraction of the silico‐ferrite of calcium and aluminum (SFCA), which is a low‐melting‐point bonding phase formed during sintering. Calcium ferrite (CF)‐containing alumina is known to be the structural basis for SFCA and SFCA‐1, and provides basic information regarding the influence of Al2O3 on the formation of CF solid solutions. In this work, experiments are conducted to investigate the crystallization behaviors of an Fe2O3–CaO–Al2O3 system based on its Al2O3 content and cooling rate. The effects of Al2O3 additions are used to analyze changes in the phase formation temperature, phase ratio, and rate of decrease by using an in situ confocal laser‐scanning microscope, optical microscope, electron probe micro analyzer, and horizontal tube furnace. The temperatures at which the primary phase forms for various Al2O3 contents and cooling rates differ from the equilibrium temperatures, and the phase‐formation temperature ranges vary with the cooling rate.
Thirty‐Five Years of the Gradual Release of Responsibility: Scaffolding Toward Complex and Responsive Teaching
Authors: Webb Sandra , Massey Dixie , Goggans Melinda , Flajole Kelly
Published: March 2019

It has been more than 35 years since Pearson and Gallagher's landmark study on the gradual release of responsibility. How has this instructional practice endured the test of time? In this article, the authors revisit the history of the gradual release of responsibility, explore current practices and challenges for educators, and provide implications for contemporary classrooms.
Photocatalytic degradation of ibuprofen in water using TiO2 and ZnO under artificial UV and solar irradiation
Authors: Tanveer Muhammad , Guyer Gokce Tezcanli , Abbas Ghulam
Published: March 2019

The degradation of anti‐inflammatory and antipyretic drug (Ibuprofen; IBP) has been described in this study by using photocatalytic‐based advanced oxidation processes. The catalysts (TiO2 and ZnO) were activated by irradiation of artificial UV lamp and solar rays for the generation of highly oxidizing species which resulted in the degradation of IBP to intermediates and finally to carbon dioxide and water. In solar reactor, quartz and borosilicate tubes were installed for absorption of required ultraviolet rays and curved chrome plates were used to reflect and concentrate rays on the tubes containing feed mixture. The liquid chromatography, Total organic carbon (TOC), and Chemical oxygen demand (COD) tests were employed to determine the degradation rates and demineralization of solution samples. At catalyst dosing of 1–1.5 g/L, TiO2‐based experiments showed high degradation rate under acidic conditions. Similarly, for ZnO catalyst, 1 g/L dozing rate was found to be effective under neutral conditions (pH = 7.0). UV lamp‐based photocatalysis had higher degradation rate as compared to that of solar reactor. Moreover, better absorption of solar rays by quartz tubes resulted in higher degradation than that in borosilicate tubes. For UV lamp photocatalysis, the TOC and COD reduction was higher. With improved catalyst doping and better solar reactor design, solar‐based IBP degradation could be more promising than UV‐based catalysis.

Practitioner points

TiO2 and ZnO were employed to generate oxidizing agents for comparative photocatalytic degradation.

Degradation rate of Ibuprofen with TiO2 was much higher compared to ZnO.

Quartz material was found more effective as radiation absorbing material than borosilicate glass for solar photo catalysis.

Influence of catalyst loading (TiO2 and ZnO) and pH conditions on degradation rate and mineralization of IBP was examined.

IBP is a carcinogenic and endocrine disrupting drug so its degradation in water can protect ecological and human life.
Livestock Herbivory Shapes Fire Regimes and Vegetation Structure Across the Global Tropics
Authors: Bernardi Rafael E. , Staal Arie , Xu Chi , Scheffer Marten , Holmgren Milena
Published: March 2019

Livestock grazing is the most extensive human land use and one of the key drivers of the conversion of tropical forests into grasslands. Livestock effects on vegetation structure are complex, as they can prevent tree recruitment and growth through browsing and trampling, but they can also affect vegetation indirectly through fire interactions. However, a systematic analysis of the overall effects of livestock across the global tropics is lacking. We analyzed remote sensing data on vegetation height and cover, climate, and fire as well as ground data on livestock density. We used generalized linear models and structural equation models to analyze the effects of livestock on fire regimes and vegetation structure. Across the global tropics, higher livestock densities are associated to lower fire frequency and a higher cover of shrubs and dwarf trees. This pattern occurs across continents, and is particularly pronounced at intermediate precipitation levels (1000–1500 mm y−1) where fire frequency is highest. In those regions, fire frequency is on average 49% lower in areas with high versus low livestock densities. South America has much higher livestock density and lower fire frequency than Africa and Asia–Australia across the whole precipitation gradient. Our findings suggest that livestock grazing reduces fire incidence through grass consumption and favors shrubs and a sparse cover of trees in regions where forests could potentially exist. Livestock can thus be a strong modifier of the climatic effect on vegetation structure, and livestock management changes can impact the structure and functioning of savannas and grasslands throughout the global tropics.
Building a novel classifier based on teaching learning based optimization and radial basis function neural networks for non-imputed database with irrelevant features
Authors: Dash Ch. Sanjeev Kumar , Kumar Behera Ajit , Dehuri Satchidananda , Cho Sung-Bae
Published: March 2019

This work presents a novel approach by considering teaching learning based optimization (TLBO) and radial basis function neural networks (RBFNs) for building a classifier for the databases with missing values and irrelevant features. The least square estimator and relief algorithm have been used for imputing the database and evaluating the relevance of features, respectively. The preprocessed dataset is used for developing a classifier based on TLBO trained RBFNs for generating a concise and meaningful description for each class that can be used to classify subsequent instances with no known class label. The method is evaluated extensively through a few bench-mark datasets obtained from UCI repository. The experimental results confirm that our approach can be a promising tool towards constructing a classifier from the databases with missing values and irrelevant attributes.
Uric Acid Levels Correlate with Sensory Nerve Function in Healthy Subjects
Authors: Abraham Alon , Katzberg Hans D. , Lovblom Leif E. , Perkins Bruce A. , Bril Vera
Published: March 2019

Background: High levels of uric acid (UA) are associated with various peripheral neuropathies. Furthermore, uric acid levels have been found to correlate with both the clinical and electrophysiological severity of diabetic sensorimotor polyneuropathy, mainly with sensory functions. Objectives: To determine whether higher UA levels are associated negatively with nerve function in healthy subjects. Methods: A total of 126 healthy subjects recruited prospectively for another study were included. We extracted demographic data, body mass index (BMI), blood pressure, Toronto Clinical Neuropathy Score (TCNS), electrophysiological findings, vibration perception thresholds (VPT), and laboratory test results including UA, hemoglobin A1c (HbA1c), estimated glomerular filtration rate (eGFR), and lipid levels. Results: The mean age of the cohort was 56 ± 17 years with 56% females. Males had higher UA values compared with females. Univariate beta regression coefficient analysis between UA levels and demographic, clinical, electrophysiological, and laboratory findings showed significant positive correlations with male gender, components of the metabolic syndrome, and with VPT, while an inverse correlation was found with electrophysiological sensory parameters. A multivariate regression model showed positive correlations only with BMI, finger VPT, and triglycerides. Conclusion: Higher UA levels correlate with lower sensory nerve function in healthy subjects, expanding the evidence of possible negative influence of UA on peripheral nerves, although a causative role has not yet established.
Long frontal waves and dynamic scaling in freely evolving equivalent barotropic flow
Authors: Burgess B. H. , Dritschel D. G.
Published: March 2019

We present a scaling theory that links the frequency of long frontal waves to the kinetic energy decay rate and inverse transfer of potential energy in freely evolving equivalent barotropic turbulence. The flow energy is predominantly potential, and the streamfunction makes the dominant contribution to potential vorticity (PV) over most of the domain, except near PV fronts of width $O(L_{D})$, where $L_{D}$ is the Rossby deformation length. These fronts bound large vortices within which PV is well-mixed and arranged into a staircase structure. The jets collocated with the fronts support long-wave undulations, which facilitate collisions and mergers between the mixed regions, implicating the frontal dynamics in the growth of potential-energy-containing flow features. Assuming the mixed regions grow self-similarly in time and using the dispersion relation for long frontal waves (Nycander et al., Phys. Fluids A, vol. 5, 1993, pp. 1089–1091) we predict that the total frontal length and kinetic energy decay like $t^{-1/3}$, while the length scale of the staircase vortices grows like $t^{1/3}$. High-resolution simulations confirm our predictions.
Gravity–capillary jet-like surface waves generated by an underwater bubble
Authors: Kang Youn J. , Cho Yeunwoo
Published: March 2019

Jet-like surface waves generated by an electric-spark-generated underwater bubble are experimentally studied. Three different motions of jet-like surface waves are observed depending on the inception position of the bubble ($d$: 0.28–7 mm) below the free surface and the maximum radius of the bubble ($R_{m}$: 1.5–3.6 mm). When $d/R_{m}>1.3$, the surface wave shows a simple smooth hump (case 1). When $0.82<d/R_{m}<1.3$, a single droplet or multiple droplets are pinched off sequentially or simultaneously at the tip or from some points of the jet-like surface wave (case 2). Finally, when $d/R_{m}<0.82$, a series of squirting and jetting phenomena are observed at the top of the jet-like surface wave (case 3). For case 1, a proportional relationship is found between $\unicode[STIX]{x1D70C}gh/\unicode[STIX]{x0394}p$ and $(d/R_{m})^{-4.4}$, where $\unicode[STIX]{x1D70C}$ is the density of the fluid, $g$ is the gravitational acceleration and $\unicode[STIX]{x0394}p$ is the difference between the reference atmospheric pressure and the vapour pressure inside a bubble. This proportional relationship is explained semi-analytically using a scaling argument and conservation of momentum and energy, with the help of the Kelvin impulse theory. In addition, we solve the relevant axisymmetric Cauchy–Poisson problem where the initial condition is a jet-like surface wave near its maximum height. By comparing the analytical wave solution with the observed surface wave pattern, it is found that the resultant surface waves are indeed gravity–capillary waves where both the gravity and the surface tension are equally important.
Pulsatile flow in a constricted channel: flow behaviour and equilibrium states
Authors: Isler João A. , Gioria Rafael S. , Carmo Bruno S.
Published: March 2019

Results are reported from linear and nonlinear stability analyses of pulsatile flow in a straight channel with a smooth constriction with 50 % occlusion. Physical mechanisms based on the energy variation of the two-dimensional modes are proposed to elucidate the equilibrium states and changes in the flow-field behaviour. When investigating how the energy of the two-dimensional modes varied with Reynolds number, an energy minimum was observed before the primary instability, so that it marked the Reynolds number value at which the flow field started to exhibit one pulse front per cycle downstream of the constriction. In addition, this flow is characterized by a bistable system in two dimensions, whose equilibrium states are related to the energy level of the two-dimensional mode. The energy difference between the equilibrium states surprisingly decreases from the lower to the higher Reynolds number, which indicates that the system should converge to a unique solution at high Reynolds number. Regarding the flow’s nature, the equilibrium state with higher energy presented a vortex pair soon after the constriction, with vorticity opposite to that of the base flow separating shear layers.
Quantifying the non-equilibrium characteristics of heterogeneous gas–solid flow of smooth, inelastic spheres using a computational fluid dynamics–discrete element method
Authors: Wang Jing , Chen Xizhong , Bian Wei , Zhao Bidan , Wang Junwu
Published: March 2019

Continuum modelling of dense gas–solid flows strongly depends on the constitutive relations used, including the interphase drag force, particle phase stress and the boundary condition for particle–wall interactions. The lack of scale separation is usually claimed to cause the breakdown of the Navier–Stokes (NS) order continuum theory. In this study, computational fluid dynamics–discrete element method (CFD-DEM) simulations of bubbling, turbulent and fast fluidization of smooth, inelastic spheres were conducted to systematically analyse the valid range of NS theory. An entropy-based criterion $I_{s}$ and Knudsen numbers defined using different characteristic length scales ($Kn_{frac}$, $Kn_{gran}$ and $Kn_{vel}$) were quantified. It was found that (i) except at the centre of bubbles where the solid concentration is quite low, NS theory for discrete particles was valid for bubbling fluidization irrespective of the breakdown criterion. Even at the boundary of the bubbles, values of $I_{s}$ and $Kn$ were small; and (ii) the conclusion depended on the criterion used in turbulent and fast fluidization. If $Kn_{frac}$ was used, NS theory would be generally valid. If $I_{s}$ was chosen, NS theory would be still valid but with lower confidence. However, if $Kn_{vel}$ or $Kn_{gran}$ was selected, NS theory broke down. Because $I_{s}$ includes the non-equilibrium effects caused by the gradient of hydrodynamic fields and particle inelasticity, we may conclude that NS theory was valid for all tested cases. This means that the continuum description of discrete particles is not the main source of the breakdown of NS theory.
Turbulent kinetic energy production and flow structures in flows past smooth and rough walls
Authors: Orlandi P.
Published: March 2019

Data available in the literature from direct numerical simulations of two-dimensional turbulent channels by Lee & Moser (J. Fluid Mech., vol. 774, 2015, pp. 395–415), Bernardini et al. (J. Fluid Mech., 742, 2014, pp. 171–191), Yamamoto & Tsuji (Phys. Rev. Fluids, vol. 3, 2018, 012062) and Orlandi et al. (J. Fluid Mech., 770, 2015, pp. 424–441) in a large range of Reynolds number have been used to find that $S^{\ast }$ the ratio between the eddy turnover time ($q^{2}/\unicode[STIX]{x1D716}$, with $q^{2}$ being twice the turbulent kinetic energy and $\unicode[STIX]{x1D716}$ the isotropic rate of dissipation) and the time scale of the mean deformation ($1/S$), scales very well with the Reynolds number in the wall region. The good scaling is due to the eddy turnover time, although the turbulent kinetic energy and the rate of isotropic dissipation show a Reynolds dependence near the wall; $S^{\ast }$, as well as $-\langle Q\rangle =\langle s_{ij}s_{ji}\rangle -\langle \unicode[STIX]{x1D714}_{i}\unicode[STIX]{x1D714}_{i}/2\rangle$ are linked to the flow structures, and also the latter quantity presents a good scaling near the wall. It has been found that the maximum of turbulent kinetic energy production $P_{k}$ occurs in the layer with $-\langle Q\rangle \approx 0$, that is, where the unstable sheet-like structures roll-up to become rods. The decomposition of $P_{k}$ in the contribution of elongational and compressive strain demonstrates that the two contributions present a good scaling. However, the good scaling holds when the wall and the outer structures are separated. The same statistics have been evaluated by direct simulations of turbulent flows in the presence of different types of corrugations on both walls. The flow physics in the layer near the plane of the crests is strongly linked to the shape of the surface and it has been demonstrated that the $u_{2}$ (normal to the wall) fluctuations are responsible for the modification of the flow structures, for the increase of the resistance and of the turbulent kinetic energy production.
Measuring Geographic Distribution for Political Research
Authors: Lee Dong Wook , Rogers Melissa
Published: March 2019

Political scientists are increasingly interested in the geographic distribution of political and economic phenomena. Unlike distribution measures at the individual level, geographic distributions depend on the “unit question” in which researchers choose the appropriate political subdivision to analyze, such as nations, subnational regions, urban and rural areas, or electoral districts. We identify concerns with measuring geographic distribution and comparing distributions within and across political units. In particular, we highlight the potential for threats to inference based on the modifiable areal unit problem (MAUP), whereby measuring concepts at different unit aggregations alters the observed value. We offer tangible options for researchers to improve their research design and data analysis to limit the MAUP. To help manage the measurement error when the unit of observation is unclear or appropriate data are not available, we introduce a new measure of geographic distribution that accounts for fluctuations in the scale and number of political units considered. We demonstrate using Monte Carlo simulations that our measure is more reliable and stable across political units than commonly used indicators because it reduces measurement fluctuations associated with the MAUP.
Aeolian delivery to Ulleung Basin, Korea (Japan Sea), during development of the East Asian Monsoon through the last 12 Ma
Authors: Anderson CH , Murray RW , Dunlea AG , Giosan L , Kinsley CW , McGee D , Tada R
Published: March 2019

We reconstruct the provenance of aluminosilicate sediment deposited in Ulleung Basin, Japan Sea, over the last 12 Ma at Site U1430 drilled during Integrated Ocean Drilling Program Expedition 346. Using multivariate partitioning techniques (Q-mode factor analysis, multiple linear regressions) applied to the major, trace and rare earth element composition of the bulk sediment, we identify and quantify four aluminosilicate components (Taklimakan, Gobi, Chinese Loess and Korean Peninsula), and model their mass accumulation rates. Each of these end-members, or materials from these regions, were present in the top-performing models in all tests. Material from the Taklimakan Desert (50–60 % of aluminosilicate contribution) is the most abundant end-member through time, while Chinese Loess and Gobi Desert components increase in contribution and flux in the Plio-Pleistocene. A Korean Peninsula component is lowest in abundance when present, and its occurrence reflects the opening of the Tsushima Strait at c. 3 Ma. Variation in dust source regions appears to track step-wise Asian aridification influenced by Cenozoic global cooling and periods of uplift of the Tibetan Plateau. During early stages of the evolution of the East Asian Monsoon, the Taklimakan Desert was the major source of dust to the Pacific. Continued uplift of the Tibetan Plateau may have influenced the increase in aeolian supply from the Gobi Desert and Chinese Loess Plateau into the Pleistocene. Consistent with existing records from the Pacific Ocean, these observations of aeolian fluxes provide more detail and specificity regarding the evolution of different Asian source regions through the latest Cenozoic.
STAIRWAYS IN THE DARK: SOUND, SYNTAX AND THE SUBLIME IN HAAS'SIN VAIN
Authors: Hutchinson Mark
Published: March 2019

The glowing critical response to Georg Friedrich Haas'sin vain(2000) has focused particularly on the visceral effect created by Haas's use of ‘endless’ scales, richly saturated microtonal chords, and passages that take place in total darkness. Discussion of these features has often led reviewers and commentators to use forms of description and praise which evoke the old (but lately rejuvenated) aesthetic category of the sublime. This article explores these connections with sublime aesthetics in more detail as a way of clarifying both philosophical and interpretative perspectives onin vain. The idea of the sublime serves as a thread connecting aspects of spectral technique and aesthetics, the mathematical visions of M.C. Escher, and the charged socio-political context in which the work was written.
WOVEN: THE MUSIC OF EGIDIJA MEDEKŠAITĖ
Authors: Fox Christopher
Published: March 2019

The Lithuanian composer Egidija Medekšaitė (b. 1979) has developed a practice in which she uses the principles of textile weaving to make musical compositions. This article introduces a series of works created in the last three years in which she has refined these techniques; it also considers the nature of the relationship between the textile patterns that Medekšaitė uses as the basis for these works and the resultant music. In particular the article focuses on an analytical account of four works: Âkâsha for string orchestra (2015), the string quartet Megh Malhar (2016), a setting of the Nunc dimittis (2018), and Sattva for electronics and accordion (2018).
GLIMMERS IN A DARK AGE: AN INTRODUCTION TO THE MUSIC OF GUILLAUME CONNESSON
Authors: Hughes Bernard
Published: March 2019

Guillaume Connesson (b. 1970) is one of the most widely performed living French composers, but his work is hardly programmed in Britain. He is well represented in commercial recordings and has been championed by the conductor Stéphane Denève across Europe and the United States. His music is in a post-minimalist, quasi-tonal language that is both engaging and contemporary, and he places himself in the firmly in the ‘musical family’ of French composers.
Adaptive Proxy-Based Controller of an Active Ankle Foot Orthosis to Assist Lower Limb Movements of Paretic Patients
Authors: Huo Weiguang , Arnez-Paniagua Victor , Ding Guangzheng , Amirat Yacine , Mohammed Samer
Published: March 2019

This paper deals with the control of an active ankle foot orthosis (AAFO) for paretic patients. State of the art methods using an AAFO try to track a predefined trajectory of the ankle joint while guaranteeing the wearer’s safety in the presence of a large tracking error. Combining the wearer’s safety and tracking accuracy is generally difficult to achieve at the same time, hence a trade-off should be found. Proxy-based sliding mode control (PSMC) offers great performances in both position tracking and safety guarantee. However, its tracking performance is subject to the influences of parameter uncertainties and external disturbances that generally occur during walking. This paper introduces an adaptation interaction method to the basic PSMC with an online adaptation of the proportional, integral and derivative parameters. At the same time, a gait phase-based ankle reference generation algorithm was proposed to adjust the joint reference trajectory in real time. The experiments using the AAFO show better tracking results with respect to basic PSMC while guaranteeing the safety.
Landscape correlates of anuran functional connectivity in rice crops: a graph-theoretic approach
Authors: Ribeiro Joana , Colli Guarino R. , Soares Amadeu
Published: March 2019

Habitat fragmentation is a major cause of biodiversity loss in agricultural landscapes. Studying habitat connectivity in fragmented landscapes is therefore pivotal for better understanding the factors that shape faunal communities in anthropogenic landscapes. Amphibians have limited dispersal abilities, strong site fidelity and often perform seasonal movements to reach relatively distant breeding habitats. This calls for a better knowledge of which landscape features might promote dispersal, especially in crops. We applied graph-theoretic network analyses to a set of 35 waterbodies embedded in 10 rice fields in a savanna–rain forest ecotone, Tocantins, Brazil, to assess the importance of landscape features (forest patches, waterbodies) for anuran functional connectivity within the entire network. We used taxonomic, functional and phylogenetic diversity as proxies of anuran functional connectivity (i.e. dispersal ability intrinsic to the taxa), based on previous associations uncovered between species diversity metrics and landscape connectivity. We found that, assuming individuals belonging to each of the 14 amphibian species recorded are unable to disperse over 800 m, forest and waterbody area and abundance are the most important predictors of waterbody importance for connectivity. Hence, pond network connectivity for amphibians in rice crops depends on (1) abundant and large forest patches in the area surrounding waterbodies, and (2) a network of abundant waterbodies.
Modelling diverse sources of Clostridium difficile in the community: importance of animals, infants and asymptomatic carriers
Authors: McLure A. , Clements A. C. A. , Kirk M. , Glass K.
Published: March 2019

Clostridium difficile infections (CDIs) affect patients in hospitals and in the community, but the relative importance of transmission in each setting is unknown. We developed a mathematical model of C. difficile transmission in a hospital and surrounding community that included infants, adults and transmission from animal reservoirs. We assessed the role of these transmission routes in maintaining disease and evaluated the recommended classification system for hospital- and community-acquired CDIs. The reproduction number in the hospital was <1 (range: 0.16–0.46) for all scenarios. Outside the hospital, the reproduction number was >1 for nearly all scenarios without transmission from animal reservoirs (range: 1.0–1.34). However, the reproduction number for the human population was <1 if a minority (>3.5–26.0%) of human exposures originated from animal reservoirs. Symptomatic adults accounted for <10% transmission in the community. Under conservative assumptions, infants accounted for 17% of community transmission. An estimated 33–40% of community-acquired cases were reported but 28–39% of these reported cases were misclassified as hospital-acquired by recommended definitions. Transmission could be plausibly sustained by asymptomatically colonised adults and infants in the community or exposure to animal reservoirs, but not hospital transmission alone. Under-reporting of community-onset cases and systematic misclassification underplays the role of community transmission.
Review of periodical articles
Authors: BUYLAERT FREDERIK , VERHOEVEN GERRIT , VERMOESEN REINOUD , VERLAAN TIM
Published: March 2019

From an empirical perspective, archaeologists and historians face a somewhat peculiar challenge, that is, to understand a past that is no longer with us through the discussion of wide range of objects – buildings, texts, textiles and so on – that are mere relics of that past. This challenge is complicated by what the anthropologist Arjun Appaduraj has famously called ‘the social life of things’. The material remnants of past societies do not survive in a vacuum: instead, these objects are used and re-used in new contexts in which they acquire new meanings, be it as cherished family heirlooms, as stuffy museum objects or as irritating obstacles for project developers. Consequently, these objects are suspended between the past and the present, in the sense that – as Joseph Morsel mordantly put it – ‘a restored castle is essentially a trophy of a new social system, whose might is expressed through the ruins of another social system’. Proceeding from the insight that the original meaning of objects is often clouded by the current context in which they function, historians and archaeologists are increasingly attentive to the question why – and if so, how – some material remnants of the past are re-used whereas others are not.
Why the Days Seem Shorter as We Get Older
Authors: Bejan Adrian
Published: March 2019

Why does it feel that the time passes faster as we get older? What is the physical basis for the impression that some days are slower than others? Why do we tend to focus on the unusual (the surprise), not on the ever present? This article unveils the physics basis for these common observations. The reason is that the measurable ‘clock time’ is not the same as the time perceived by the human mind. The ‘mind time’ is a sequence of images, i.e. reflections of nature that are fed by stimuli from sensory organs. The rate at which changes in mental images are perceived decreases with age, because of several physical features that change with age: saccades frequency, body size, pathways degradation, etc. The misalignment between mental-image time and clock time serves to unite the voluminous observations of this phenomenon in the literature with the constructal law of evolution of flow architecture, as physics.