bluuebunny/crossref_metadata_2025 huggingface dataset:
Living Together in the Mediatized City: The Figurations of Young People’s Urban Communities
Authors: Hepp Andreas , Simon Piet , Sowinska Monika
Published: November 2017

What does deep mediatization mean to young people in their daily urban sense of community? Posing this question, the chapter analyzes the mediatization of young people’s urban community building in two German cities: Bremen and Leipzig. In doing so, ‘urban sense of community’ is not treated as a given, but as communicatively constructed in an open process that can assume different empirical forms. The chapter demonstrates that for young urban dwellers—besides family, acquaintances and colleagues—it is their network of friends that remains the primary figuration of their experience of community construction. However, mediatization is not only of importance when it comes to the communicative networking of young people via different digital devices. In addition, the frequented locations that are of importance for an ‘urban sense of community’ are highly mediatized. This can be understood as the figurative quality of individual sites of community construction; that is, the way the mediatization of particular locations in the city lends them a particular quality of community construction. Such an analysis leads to the question concerning the extent to which the city can, for young people, be something like an imagined community.
The Transformation of Journalism: From Changing Newsroom Cultures to a New Communicative Orientation?
Authors: Kramp Leif , Loosen Wiebke
Published: November 2017

This chapter draws on three research projects on journalism, audience practices and newsroom cultures and uses them to illustrate the changing nature of the communicative relationship between journalists and audiences operating in a media environment characterized by digital technologies. This development in communicative practices is already yielding changes in traditional newsroom routines and could lead to a shift in the communicative orientation of journalism that puts an emphasis on dialogue, moderation and curation, instead of the unidirectional dissemination of news, a kind of dissemination that might not suffice any longer as a unique characteristic for journalism in the pluralistic information ecosphere of the digital realm. However, this chapter highlights that this transition follows neither a linear nor a simultaneous process for all segments of journalism, for all journalists or all audience members. In sum, this chapter confronts expectations about innovative journalistic practices and highlights how communicative forms and media ensembles, which were not available in the predigital era, establish new modes of dialogue with audiences. The conclusion discusses how this transformation of communicative figurations among journalists and media users affects their self-conception with regards to their roles and core functions in their given community and in society as a whole.
Understanding Power Anomalies in Mediation Analysis
Authors: Wang Kai
Published: November 2017

Previous studies have found some puzzling power anomalies related to testing the indirect effect of a mediator. The power for the indirect effect stagnates and even declines as the size of the indirect effect increases. Furthermore, the power for the indirect effect can be much higher than the power for the total effect in a model where there is no direct effect and therefore the indirect effect is of the same magnitude as the total effect. In the presence of direct effect, the power for the indirect effect is often much higher than the power for the direct effect even when these two effects are of the same magnitude. In this study, the limiting distributions of related statistics and their non-centralities are derived. Computer simulations are conducted to demonstrate their validity. These theoretical results are used to explain the observed anomalies.
Political Participation Today: A Radical Shift, But with a Positive or Negative Outcome?
Authors: Hartleb Florian
Published: November 2017

Political participation can be regarded as a basic need in democracies. After a worrying 2016, a year of populism and post-truth politics, two different narratives for the future have emerged: one optimistic, the other pessimistic. The former refers to a growing pro-European spirit and the arrival of a new civic culture, epitomised by movements such as Pulse of Europe. The latter sees the worrying growth of fake news and the decline of traditional institutions, as well as the rise of authoritarian tendencies, which seems to indicate that political engagement is seen as old-fashioned. In any case, today's reality in this age of new technology requires a project- and network-based approach.
Geopolitics and Security in the Arctic: What Role for the EU?
Authors: Østhagen Andreas
Published: November 2017

The Arctic has received considerable attention over the last decade due to climate change, positive resource appraisals and the increased military presence in the region. Portrayals range from those that warn of impending conflicts to those that emphasise the region's unique cooperative environment. To what extent are the generalisations about Arctic security and geopolitics accurate? What fuels these generalisations? Moreover, what is the role of the EU in this changing geopolitical environment? This article examines the causes of conflict in the Arctic and argues that the disputes over territory, resources and the North Pole are limited in magnitude. At the same time, the security dynamics within the Arctic are relevant, given each state's relations to Russia. The EU's role, however, is less a geopolitical one and more concerned with two dimensions, namely awareness and support. For EU policymakers and decision-makers, understanding the complexities of the north should take priority over re-inventing the Union's role in the region.
Constraints on the Genesis of the Jiande Polymetallic Copper Deposit in South China Using Fluid Inclusion and O-H-Pb Isotopes
Authors: Chen Hui , Ni Pei , Chen Ren-Yi , Lü Zhi-Cheng , Ye Tian-Zhu , Wang Guo-Guang , Pan Jun-Yi , Pang Zhen-Shan , Xue Jian-Ling , Yuan Hui-Xiang
Published: November 2017

The Jiande copper deposit is located in the Qin-Hang metallogenic belt, South China. The deposit is dominated by “stratiform-like” ores, which are hosted in the dolomite of the Upper Carboniferous Huanglong Formation. These ore bodies were previously proposed to be Carboniferous sedimentary exhalative (Sedex) style mineralization, but they also appear to be related to the Late Mesozoic granodiorite porphyry at Jiande. Three stages of mineralization can be observed. The prograde skarn minerals garnet and diopside were formed in the pre-ore stage. The “stratiform-like” ores, with minor quartz-polymetallic veins, were formed in the main mineralization stage. The post-ore stage is characterized by quartz-calcite ± pyrite veins. Fluid inclusions in quartz from the pre-ore skarn, the main stage of mineralization, and post-ore quartz–calcite ± pyrite veins were studied. Fluid inclusion petrography shows that two-phase liquid-rich (Type I), two-phase vapor-rich (Type II), and halite-bearing (Type III) fluid inclusions can be identified in the studied hydrothermal quartz samples. Primary Type II and Type III fluid inclusions only occur in quartz from the the main stage, whereas Type I fluid inclusions are present in all three stages of hydrothermal quartz. Type I fluid inclusions in pre-ore stage have homogenization temperatures of 290-368°C and salinities of 2.6-8.8 wt.% NaCl equiv. Type II and coexisting Type III fluid inclusions in the main stage share similar homogenization temperatures of 293 to 334 °C and 290 to 326 °C,but have two contrasting salinity ranges of 1.2 to 2.2 wt.% and 31.87 to 38.16 wt.% NaCl equiv, respectively. The coexistence of Type II and Type III fluid inclusions and their similar homogenization temperatures but contrasting salinities suggest that fluid boiling processes occurred. Type I fluid inclusions in the post-ore quartz–calcite veins have homogenization temperatures of 202-278 °C and salinities of 0.2-6.5 wt.% NaCl equiv. The hydrogen and oxygen isotopes (δD ranges from -78 ‰ to -61 ‰, δ18OH2O calculated from quartz are from 8.1 ‰ to 10.6 ‰) of fluid inclusions in quartz imply that ore fluids were principally derived from magmatic water. The lead isotopes of sulfide from the ores are close to the orogenic Pb evolution curve and are also similar to those of the Jiande Jurassic igneous rocks, suggesting that the metals were sourced mostly from the Jurassic igneous rocks. The skarn alteration, inferred boiling fluid inclusion assemblages, stable isotopic features of magmatic fluids, and metal source imply that the main stages of mineralization in the Jiande polymetallic copper deposit is of skarn-type, related to Jurassic granodiorites.
Volatiles Associated with Granitoid Intrusives around Orogenic Gold Deposits in Ramagiri and Penakacherla Regions of Eastern Dharwar Craton, South India
Authors: Bhattacharya Sourabh , Panigrahi Mruganka K.
Published: November 2017

The nature of magmatic fluid has been tested well in varied type of auriferous deposits. However, in context of orogenic gold deposits, there are not many studies that clearly point out the nature of fluids exsolved out of crystallizing granitoids. This study compares the fluid of late-stage magmatic origin with that causative for mineralization in gold camps of Ramagiri and Penakacherla in Eastern Dharwar Craton. Various types of fluid inclusion assemblages (FIAs) were identified in granitoid matrix quartz, pegmatites, quartz segregations and greenstone-hosted gold-quartz veins. The aqueous-carbonic (CH4-poor) and carbonic (CH4- and H2O-poor) inclusions are most common in pegmatites and quartz segregations, while the matrix quartz grains are generally devoid of CO2-bearing inclusions. On the other hand, auriferous veins in greenstone rocks show predominance of low to moderate salinity, aqueous-carbonic (variably CH4-bearing) inclusions. Inconsistencies in H2O/CO2 ratio and final homogenization properties of aqueous-carbonic inclusions within individual FIAs, apart from common occurrence of the FIA comprising aqueous-carbonic, carbonic and aqueous biphase inclusions, point to immiscibility in the ore fluid regime. Based on estimated microthermometric results, we attempt to deduce the evolution path of magmatic fluid with respect to that of fluid in ore zone. On this basis, a case for magmatic derivation of the ore fluid has been put forward. The difference in magmatic and auriferous fluid in terms of CO2/CH4 ratio are justifiable and allows us to visualize that aqueous-carbonic composition of orogenic gold fluid does not signify its exclusive origin through any particular process (or source), for example metamorphism.
Source and Causes of 2015 Great Pluvial Flood of Chennai, Tamil Nadu and its Surroundings
Authors: Akilan A. , Balaji S. , Abdul Azeez K. K. , Satyanarayanan M.
Published: November 2017

A catastrophic heavy downpour was recorded in the month of November-December 2015 which devastated wealth, lives, disturbed the livelihood and regular activity of common man of Chennai city and its surroundings. Indian Metrological Department (IMD), Chennai warned the people in Chennai in advance about the atmospheric depression developed in the Indian Ocean region and moving towards Tamil Nadu coast. The Numerical Weather Modeling (NWM) retrieved parameters such as temperature and Zenith Total Delay (ZTD) along with the ISC earthquake catalog were analysed for the root cause of this phenomena and found a relation between the onset of the atmospheric weather change and the swarms of 8th to 9th November 2015 in the Indian Ocean region and associated thermal radiation. These swarms are generally associated with the submarine volcanic activity which released the thermal radiation from ocean floor that caused the ocean water to warm and evaporate. The consequence of incessant rainfall and the weather condition deviated from the normal climate and monsoon pattern. Thus, the abnormal and distinct weather condition that prevailed during the period has been triggered by the swarms in the north Sumatra oceanic region and the resultant effect was the great pluvial flood disaster in Chennai and its surroundings in November-December 2015.
Composite technology for high volume lightweight manufacturing
Authors: Bank Dave H. , James Allan , Belli Selamawit , Reese Jason R. , Baumer Richard E. , Balijepalli Bharati , Ma Liangkai , Reimers Martin , Königer Rainer , Morley Timothy , Lotti Luca
Published: November 2017

This article describes two composite solutions – prepregs and resin transfer molding (RTM). Prepregs describes a new compression molding process that enables mass productions, short cycle times and reduced waste.
Interview with Sebastian Raffauf, Team Sonnenwagen Aachen
Authors: Raffauf Sebastian
Published: November 2017

Reinforced Plastics spoke with Sebastian Raffauf from Team Sonnenwagen Aachen about the development of their solar car.
The African Growth and Opportunity Act and the African Continental Free Trade Area
Authors: Davis William
Published: November 2017

This essay assesses and evaluates the extent to which the African Growth and Opportunity Act (AGOA) increased imports from AGOA eligible countries to the United States from 2001 to 2015. The essay then examines how African countries can make the most of the preferences granted under AGOA, arguing that AGOA national utilization strategies have proven successful. In the final part, the essay explores options for future U.S.-Africa trade relations after the AGOA expires in 2025, proposing approaches that would best support African development. In this regard, this essay argues that, since Congress is unlikely to renew AGOA in its current form and since AGOA will likely be replaced with an arrangement requiring some degree of reciprocity, it will be very important for (1) the African Union's Continental Free Trade Area (CFTA) to be implemented before any new U.S.-Africa trading arrangement comes into force and (2) for negotiations for any future U.S.-Africa trading arrangement not to mimic the negotiations conducted for the Economic Partnership Agreements with the European Union.
Rethinking the AGOA Model: How to Create a Pro-Structural Transformation of the U.S.-Africa Trade Partnership
Authors: Kategekwa Joy
Published: November 2017

Seventeen years into the life of the African Growth and Opportunities Act (AGOA), two key issues stand out: first, that the preference utilization rate—as indicated by the meagre increases in African exports to the United States—remains marginal; and second, that the AGOA initiative has not helped build diversified African economies. This reality in turn raises two critical issues: that Africa's structural challenges need to be addressed; and that extensions of the AGOA in and of themselves may not be the solution for the continent's economic development. Therefore, looking toward 2025 is an opportunity to have a fresh discussion with the United States, one focused on placing the African economic development challenge at the heart of the dialogue. This requires designing a new model grounded in Africa's aspirations for structural transformation of its economies from primary product to industrial product exporters.
Observations and modelling of first-year ice growth and simultaneous second-year ice ablation in the Prydz Bay, East Antarctica
Authors: Zhao Jiechen , Cheng Bin , Yang Qinghua , Vihma Timo , Zhang Lin
Published: November 2017

The seasonal cycle of fast ice thickness in Prydz Bay, East Antarctica, was observed between March and December 2012. In March, we observed a 0.16 m thickness gain of 0.22 m-thick first-year ice (FYI), while 1.16 m-thick second-year ice (SYI) nearby simultaneously ablated by 0.59 m. A 1-D thermodynamic sea-ice model was applied to identify the factors that led to the simultaneous growth of FYI and melt of SYI. The different evolutions were explained by the difference in the conductive heat flux between the FYI and SYI. As the FYI was thin, there was a large temperature gradient between the ice base and the colder ice surface. This generated an upward conductive heat flux, which was larger than the heat flux from the ocean to the ice base, yielding basal growth of ice. In the case of the thicker SYI the temperature gradient and, hence, the conductive heat flux were smaller, and not sufficient to balance the oceanic heat flux at the ice base, yielding basal ablation. Penetration of solar radiation affected the conductive heat flux in both cases, and the model results were sensitive to the initial ice temperature profile and the uncertainty of the oceanic heat flux.
Linking winter and spring thermodynamic sea-ice states at critical scales using an object-based image analysis of Sentinel-1
Authors: Scharien RK , Segal R , Yackel JJ , Howell SEL , Nasonova S
Published: November 2017

Changing Arctic sea-ice extent and melt season duration, and increasing economic interest in the Arctic have prompted the need for enhanced marine ecosystem studies and improvements to dynamical and forecast models. Sea-ice melt pond fraction fp has been shown to be correlated with the September minimum ice extent due to its impact on ice albedo and heat uptake. Ice forecasts should benefit from knowledge of fp as melt ponds form several months in advance of ice retreat. This study goes further back by examining the potential to predict fp during winter using backscatter data from the commonly available Sentinel-1 synthetic aperture radar. An object-based image analysis links the winter and spring thermodynamic states of first-year and multiyear sea-ice types. Strong correlations between winter backscatter and spring fp, detected from high-resolution visible to near infrared imagery, are observed, and models for the retrieval of fp from Sentinel-1 data are provided (r2 ≥ 0.72). The models utilize HH polarization channel backscatter that is routinely acquired over the Arctic from the two-satellite Sentinel-1 constellation mission, as well as other past, current and future SAR missions operating in the same C-band frequency. Predicted fp is generally representative of major ice types first-year ice and multiyear ice during the stage in seasonal melt pond evolution where fp is closely related to spatial variations in ice topography.
Water Cultures Are More Sensitive Than Swab Cultures for the Detection of EnvironmentalLegionella
Authors: Decker Brooke K. , Harris Patricia L. , Toy Diana L. , Muder Robert R. , Sonel Ali F. , Clancy Cornelius J.
Published: November 2017

Water cultures were significantly more sensitive than concurrently collected swab cultures (n=2,147 each) in detectingLegionella pneumophilawithin a Veterans Affairs healthcare system. Sensitivity for water versus swab cultures was 90% versus 30% overall, 83% versus 48% during a nosocomial Legionnaires’ disease outbreak, and 93% versus 22% post outbreak.

Infect Control Hosp Epidemiol2018;39:108–110
Oscillations of confined fibres transported in microchannels
Authors: Nagel M. , Brun P.-T. , Berthet H. , Lindner A. , Gallaire F. , Duprat C.
Published: November 2017

We investigate the trajectories of rigid fibres as they are transported in a pressure-driven flow, at low Reynolds number, in shallow Hele-Shaw cells. The transverse confinement and the resulting viscous friction on these elongated objects, as well as the lateral confinement (i.e. the presence of lateral walls), lead to complex fibre trajectories that we characterize with a combination of microfluidic experiments and simulations using modified Brinkman equations. We show that the transported fibre behaves as an oscillator for which we obtain and analyse a complete state diagram.
Pore-scale modelling of Ostwald ripening
Authors: de Chalendar Jacques A. , Garing Charlotte , Benson Sally M.
Published: November 2017

In a saturated solution with dispersed clusters of a second phase, the mechanism by which the larger clusters grow at the expense of the smaller ones is called Ostwald ripening. Although the mechanism is well understood in situations where multiple clusters of gas exist in a liquid solution, evolution is much more complicated to predict when the two phases interact with a solid matrix, since the solid plays a significant role in determining the shape of the interface. In this paper, we study capillary dominated regimes in porous media where the driving force is inter-cluster diffusion. By decomposing the Ostwald ripening mechanism into two processes that operate on different time scales – the diffusion of solute gas in the liquid and the readjustment of the shape of the gas–liquid interface to accommodate a change in mass – we develop a sequential algorithm to solve for the evolution of systems with multiple gas ganglia. In the absence of a solid matrix, thermodynamic equilibrium is reached when all of the gas phase aggregates to form one large bubble. In porous media on the other hand, we find that ripening can lead to equilibrium situations with multiple disconnected ganglia, and that evolution is highly dependent on initial conditions and the structure of the solid matrix. The fundamental difference between the two cases is in the relationship between mass and capillary pressure.
Turbulent flows over superhydrophobic surfaces: flow-induced capillary waves, and robustness of air–water interfaces
Authors: Seo Jongmin , García-Mayoral Ricardo , Mani Ali
Published: November 2017

Superhydrophobic surfaces can retain gas pockets within their microscale textures when submerged in water. This property reduces direct contact between water and solid surfaces and presents opportunities for improving hydrodynamic performance by decreasing viscous drag. In most realistic applications, however, the flow regime is turbulent and retaining the gas pockets is a challenge. In order to overcome this challenge, it is crucial to develop an understanding of physical mechanisms that can lead to the failure of superhydrophobic surfaces in retaining gas pockets when the overlying liquid flow is turbulent. We present a study of the onset of failure in gas retention by analysing direct numerical simulations (DNS) of turbulent flows over superhydrophobic surfaces coupled with the deformation of air–water interfaces that hold the gas pockets. The superhydrophobic surfaces are modelled as periodic textures with patterned slip and no-slip boundary conditions on the overlying water flow. The liquid–gas interface is modelled via a linearized Young–Laplace equation, which is solved coupled with the overlying turbulent flow. A wide range of texture sizes and interfacial Weber numbers are considered in this study. Our analysis identifies flow-induced upstream-travelling capillary waves that are coherent in the spanwise direction as one mechanism for failure in retention of gas pockets. To confirm physical understanding of these waves, a semianalytical inviscid linear analysis is developed; the wave speeds obtained from the space–time correlations in the DNS data were found to match with the predictions of the semianalytical model. The magnitude of the pressure fluctuations due to these waves was found to increase with decreasing surface tension, and increase with a much stronger dependence on the slip velocity, when all numbers are reported in wall units. Based on a fitted scaling, a threshold criterion for the failure of superhydrophobic surfaces is developed that is based on estimates of the onset condition required for the motion of contact lines. The second contribution of this work is the development of boundary maps that identify stable and unstable zones in a parameter space consisting of working parameter and design parameters including texture size and material contact angle. We provide a brief description of previously identified failure modes of superhydrophobic surfaces, namely the stagnation pressure and shear-driven drainage mechanisms. In an overlay map, the stable and unstable zones due to each mechanism are presented. For various input conditions, we provide scaling laws that identify the most critical mechanism limiting the stability of gas retention by superhydrophobic surfaces.
Turbulent boundary layers absent mean shear
Authors: Johnson Blair A. , Cowen Edwin A.
Published: November 2017

We perform an experimental study to investigate the turbulent boundary layer above a stationary solid glass bed in the absence of mean shear. High Reynolds number $(Re_{\unicode[STIX]{x1D706}}\sim 300)$ horizontally homogeneous isotropic turbulence is generated via randomly actuated synthetic jet arrays (RASJA – Variano & Cowen J. Fluid Mech. vol. 604, 2008, pp. 1–32). Each of the arrays is controlled by a spatio-temporally varying algorithm, which in turn minimizes the formation of secondary mean flows. One array consists of an $8\times 8$ grid of jets, while the other is a $16\times 16$ array. Particle image velocimetry measurements are used to study the isotropic turbulent region and the boundary layer formed beneath as the turbulence encounters a stationary wall. The flow is characterized with statistical metrics including the mean flow and turbulent velocities, turbulent kinetic energy, integral scales and the turbulent kinetic energy transport equation, which includes the energy dissipation rate, production and turbulent transport. The empirical constant in the Tennekes (J. Fluid Mech. vol. 67, 1975, pp. 561–567) model of Eulerian frequency spectra is calculated based on the dissipation results and temporal frequency spectra from acoustic Doppler velocimetry measurements. We compare our results to prior literature that addresses mean shear free turbulent boundary layer characterizations via grid-stirred tank experiments, moving-bed experiments, rapid-distortion theory and direct numerical simulations in a forced turbulent box. By varying the operational parameters of the randomly actuated synthetic jet array, we also find that we are able to control the turbulence levels, including integral length scales and dissipation rates, by changing the mean on-times in the jet algorithm.
Scaling law for the lift force of autorotating falling seeds at terminal velocity
Authors: Lee Injae , Choi Haecheon
Published: November 2017

We provide a scaling law for the lift force of autorotating falling seeds at terminal velocity to describe the relation among the lift force, seed geometry and terminal descending and rotating velocities. Two theories, steady wing-vortex theory and actuator-disk theory, are examined to derive the scaling law. In the steady wing-vortex theory, the strength of a leading-edge vortex is scaled with the circulation around a wing and the lift force is modelled by the time derivative of vortical impulse, whereas the conservations of mass, linear and angular momentum, and kinetic energy across the autorotating falling seed are applied in the actuator-disk theory. To examine the validity of the theoretical results, an unsteady three-dimensional numerical simulation is conducted for flow around an autorotating seed (Acer palmatum) during free fall. The sectional lift coefficient predicted from the steady wing-vortex theory reasonably agrees with that from the numerical simulation, whereas the actuator-disk theory fails to provide an estimation of the sectional lift coefficient. The weights of 11 different species of autorotating falling seeds fall on the scaling law derived from the steady wing-vortex theory, suggesting that even a simple theoretical approach can explain how falling seeds support their weights by autorotation once the circulation from a leading-edge vortex is properly included in the theory.
Evolution and stationarity of liquid toroidal drop in compressional Stokes flow
Authors: Ee B. K. , Lavrenteva O. M. , Smagin I. , Nir A.
Published: November 2017

Dynamics of fluid tori in slow viscous flow is studied. Such tori are of interest as future carriers of biological and medicinal substances and are also viewed as potential building blocks towards more complex particles. In this study the immiscible ambient fluid is subject to a compressional flow (i.e., bi-extensional flow), and it comprises a generalization of our earlier report on the particular case with viscosity ratio$\unicode[STIX]{x1D706}=1$(see Zabarankinet al.,J. Fluid Mech., vol. 785, 2015, pp. 372–400), where$\unicode[STIX]{x1D706}$is the ratio between the torus viscosity and that of the ambient fluid. It is found that, for all viscosity ratios, the torus either collapses towards the axis of symmetry or expands indefinitely, depending on the initial conditions and the capillary number,Ca. During these dynamic patterns the cross-sections exhibit various forms of deformation. The collapse and expansion dynamic modes are separated by a limited deformation into a deformed stationary state which appears to exist in a finite interval of the capillary number,$0<Ca<Ca_{cr}(\unicode[STIX]{x1D706})$, and is unstable to axisymmetric disturbances, which eventually cause the torus either to collapse or to expand indefinitely. The characteristic dimensions and shapes of these unstable stationary tori and their dependence on the physical parametersCaand$\unicode[STIX]{x1D706}$are reported.
On the multiple solutions of coating and rimming flows on rotating cylinders
Authors: Lopes André v. B. , Thiele Uwe , Hazel Andrew L.
Published: November 2017

We consider steady solutions of the Stokes equations for the flow of a film of fluid on the outer or inner surface of a cylinder that rotates with its axis perpendicular to the direction of gravity. We find that previously unobserved stable and unstable steady solutions coexist over an intermediate range of rotation rates for sufficiently high values of the Bond number (ratio of gravitational forces relative to surface tension). Furthermore, we compare the results of the Stokes calculations to the classic lubrication models of Pukhnachev (J. Appl. Mech. Tech. Phys., vol 18, 1977, pp. 344–351) and Reisfeld & Bankoff (J. Fluid Mech., vol. 236, 1992, pp. 167–196); an extended lubrication model of Benilov & O’Brien (Phys. Fluids, vol. 17, 2005, 052106) and Evans et al. (Phys. Fluids, vol. 16, 2004, pp. 2742–2756); and a new lubrication approximation formulated using gradient dynamics. We quantify the range of validity of each model and confirm that the gradient-dynamics model is most accurate over the widest range of parameters, but that the new steady solutions are not captured using any of the simplified models because they contain features that can only be described by the full Stokes equations.
DNS of a turbulent Couette flow at constant wall transpiration up to
Authors: Kraheberger S. , Hoyas S. , Oberlack M.
Published: November 2017

We present a new set of direct numerical simulation data of a turbulent plane Couette flow with constant wall-normal transpiration velocity $V_{0}$, i.e. permeable boundary conditions, such that there is blowing on the lower side and suction on the upper side. Hence, there is no net change in flux to preserve periodic boundary conditions in the streamwise direction. Simulations were performed at $Re_{\unicode[STIX]{x1D70F}}=250,500,1000$ with varying transpiration rates in the range $V_{0}^{+}\approx 0.03$ to 0.085. Additionally, a classical Couette flow case at $Re_{\unicode[STIX]{x1D70F}}=1000$ is presented for comparison. As a first key result we found a considerably extended logarithmic region of the mean velocity profile, with constant indicator function $\unicode[STIX]{x1D705}=0.77$ as transpiration increases. Further, turbulent intensities are observed to decrease with increasing transpiration rate. Mean velocities and intensities collapse only in the cases where the transpiration rate is kept constant, while they are largely insensitive to friction Reynolds number variations. The long and wide characteristic stationary rolls of classical turbulent Couette flow are still present for all present DNS runs. The rolls are affected by wall transpiration, but they are not destroyed even for the largest transpiration velocity case. Spectral information indicates the prevalence of the rolls and the existence of wide structures near the blowing wall. The statistics of all simulations can be downloaded from the webpage of the Chair of Fluid Dynamics.
Dynamics and structure of an apolar active suspension in an annulus
Authors: Chen Sheng , Gao Peng , Gao Tong
Published: November 2017

We study the complex dynamics of a two-dimensional suspension comprising non-motile active particles confined in an annulus. A coarse-grained liquid crystal model is employed to describe the nematic structure evolution, and is hydrodynamically coupled with the Stokes equation to solve for the induced active flows in the annulus. For dilute suspensions, coherent structures are captured by varying the particle activity and gap width, including unidirectional circulations, travelling waves and chaotic flows. For concentrated suspensions, the internal collective dynamics features motile disclination defects and flows at finite gap widths. In particular, we observe an intriguing quasi-steady-state at certain gap widths during which $+1/2$-order defects oscillate around equilibrium positions accompanying travelling-wave flows that switch circulating directions periodically. We perform linear stability analyses to reveal the underlying physical mechanisms of pattern formation during a concatenation of instabilities.
Pressure Work and Viscous Dissipation Effects on Heat Transfer in a Parallel–Plate Microchannel Gas Flow
Authors: Ramadan K. M.
Published: November 2017

Convective heat transfer in a parallel plate microchannel gas flow is investigated analytically and numerically, considering the effects of viscous dissipation, pressure work, shear work, axial conduction and rarefaction. Analysis is performed with constant wall temperature and constant wall heat flux boundary conditions for both gas cooling and heating. The results presented demonstrate the significance of the combined effect of pressure work and viscous dissipation, shear work, rarefaction degree and axial conduction on microchannel convective heat transfer, in both the thermally developing and fully developed flow regions. Viscous dissipation and pressure work in a pressure-driven microchannel gas flow are of comparable magnitudes and may not be neglected from the energy equation. The shear work at the wall, which is effectively the combined effect of viscous dissipation and pressure work, needs to be included in the Nusselt number for better predictions of heat transfer.
Gender, individualism–collectivism and individuals’ propensity to trust: A comparative exploratory study
Authors: Zeffane Rachid
Published: November 2017

We explore the impact of gender, individualism–collectivism on individual’s propensity to trust. The study draws on data from three groups of individuals in the United Arab Emirates: students; (n=370); small business owners/operators (n=324), and employed individuals (n=376). Three main hypotheses are tested. We develop and explore three main hypotheses. Statistical results reveal that females are generally more collectivist and less trusting than their males counterparts. Further analysis revealed that small business/operators are generally more trusting than the other cohorts of respondents. Propensity to trust was also found to be strongly associated with collectivist (rather than individualist) aspirations. Implications for future research and management practice are discussed.
On the Dynamics of Ideological Identification: The Puzzle of Liberal Identification Decline
Authors: Coggins Elizabeth , Stimson James A.
Published: November 2017

Our focus is a puzzle: that ideological identification as “liberal” is in serious decline in the United States, but at the same time support for liberal policies and for the political party of liberalism is not. We aim to understand this divorce in “liberal” in name and “liberal” in policy by investigating how particular symbols rise and fall as associations with the ideological labels “liberal” and “conservative.” We produce three kinds of evidence to shed light on this macro-level puzzle. First, we explore the words associated with “liberal” and “conservative” over time. Then we take up a group conception by examining the changing correlations between affect toward “liberals” and affect toward other groups. Finally, we consider the changing policy correlates of identification.
Effect of maternal dyslipidaemia on the cardiorespiratory physiology and biochemical parameters in male rat offspring
Authors: Guimarães Keyth Sulamitta L. , de Araújo Emmanuel Veríssimo , Aquino Jailane Souza , Gadelha Danilo Assis , Balarini Camille Moura , Costa-Silva João Henrique , Magnani Marciane , Vidal Hubert , Braga Valdir Andrade , de Brito Alves José Luiz
Published: November 2017

The present study evaluated the effects of maternal dyslipidaemia on blood pressure (BP), cardiorespiratory physiology and biochemical parameters in male offspring. Wistar rat dams were fed either a control (CTL) or a dyslipidaemic (DLP) diet during pregnancy and lactation. After weaning, both CTL and DLP offspring received standard diet. On the 30th and 90th day of life, blood samples were collected for metabolic analyses. Direct measurements of BP, respiratory frequency (RF), tidal volume (VT) and ventilation (VE) under baseline condition, as well as during hypercapnia (7 % CO2) and hypoxia (KCN, 0·04 %), were recorded from awake 90-d-old male offspring. DLP dams exhibited raised serum levels of total cholesterol (TC) (4·0-fold), TAG (2·0-fold), VLDL+LDL (7·7-fold) and reduced HDL-cholesterol (2·4-fold), insulin resistance and hepatic steatosis at the end of lactation. At 30 d of age, the DLP offspring showed an increase in the serum levels of TC (P<0·05) and VLDL+LDL (P<0·05) in comparison with CTL offspring. At 90 d of age, DLP offspring exhibited higher mean arterial pressure (MAP, approximately 34 %). In the spectral analysis, the DLP group showed augmented low-frequency (LF) power and LF:high-frequency (HF) ratio when compared with CTL offspring. In addition, the DLP animals showed a larger delta variation in arterial pressure after administration of the ganglionic blocker (P=0·0003). We also found that cardiorespiratory response to hypercapnia and hypoxia was augmented in DLP offspring. In conclusion, the present data show that maternal dyslipidaemia alters cardiorespiratory physiology and may be a predisposing factor for hypertension at adulthood.
DO IN UTERO SHOCKS HAVE ADVERSE EFFECTS ON CHILD HEALTH OUTCOMES AND CAN WELFARE SCHEMES AMELIORATE SUCH EFFECTS? EVIDENCE FROM ANDHRA PRADESH, INDIA
Authors: Ahmed Salma , Ray Ranjan
Published: November 2017

This study aimed to assess whether shocks experienced by children in the mother’s womb can have an adverse effect on their future health, and whether these effects can be ameliorated by government welfare schemes. Data were taken from three phases of the Young Lives Survey carried out in the Indian state of Andhra Pradesh in 2002, 2007 and 2009–2010. Different types of in utero shock were distinguished from the data. Using ordinary least squares (OLS) estimation, it was observed that multiple in utero shocks reduced children’s weight-for-age and height-for-age z-scores by 0.07–0.08 and 0.08–0.15 units respectively. The roles of two Indian government welfare schemes – the Midday Meal Scheme (MDMS) and the National Rural Employment Guarantee Scheme (NREGS) – in mitigating the adverse effects of in utero shocks were examined. While the effect of the MDMS was statistically insignificant, that of the NREGS was significant. Although not designed to protect child health, the NREGS has been playing a more effective role than the MDMS in acting as a buffer against the damaging effects of in utero shocks on child health. The study points to the need for greater co-ordination between the two welfare schemes.
25(OH)D3-enriched or fortified foods are more efficient at tackling inadequate vitamin D status than vitamin D3
Authors: Guo Jing , Lovegrove Julie A. , Givens D. Ian
Published: November 2017

The ability to synthesise sufficient vitamin D through sunlight in human subjects can be limited. Thus, diet has become an important contributor to vitamin D intake and status; however, there are only a few foods (e.g. egg yolk, oily fish) naturally rich in vitamin D. Therefore, vitamin D-enriched foods via supplementing the animals’ diet with vitamin D or vitamin D fortification of foods have been proposed as strategies to increase vitamin D intake. Evidence that cholecalciferol (vitamin D3) and calcifediol (25(OH)D3) content of eggs, fish and milk increased in response to vitamin D3 supplementation of hens, fish or cows’ diets was identified when vitamin D-enrichment studies were reviewed. However, evidence from supplementation studies with hens showed only dietary 25(OH)D3, not vitamin D3 supplementation, resulted in a pronounced increase of 25(OH)D3 in the eggs. Furthermore, evidence from randomised controlled trials indicated that a 25(OH)D3 oral supplement could be absorbed faster and more efficiently raise serum 25(OH)D concentration compared with vitamin D3 supplementation. Moreover, evidence showed the relative effectiveness of increasing vitamin D status using 25(OH)D3 varied between 3·13 and 7·14 times that of vitamin D3, probably due to the different characteristics of the investigated subjects or study design. Therefore, vitamin D-enrichment or fortified foods using 25(OH)D3 would appear to have advantages over vitamin D3. Further well-controlled studies are needed to assess the effects of 25(OH)D3 enriched or fortified foods in the general population and clinical patients.
Behavioral consequences of mild traumatic brain injury in preschoolers
Authors: Gagner Charlotte , Landry-Roy Catherine , Bernier Annie , Gravel Jocelyn , Beauchamp Miriam H.
Published: November 2017

Background

Pediatric traumatic brain injury (TBI) is a leading cause of long-term disability in children and adolescents worldwide. Amongst the wide array of consequences known to occur after pediatric TBI, behavioral impairments are among the most widespread and may particularly affect children who sustain injury early in the course of development. The aim of this study was to investigate the presence of internalizing and externalizing behavioral problems 6 months after preschool (i.e. 18–60 months old) mild TBI.

Methods

This work is part of a prospective, longitudinal cohort study of preschool TBI. Participants (N = 229) were recruited to one of three groups: children with mild TBI, typically developing children and orthopedic injured (OI) children. Mothers of children in all three groups completed the Child Behavior Checklist as a measure of behavioral outcomes 6-month post-injury. Demographics, injury-related characteristics, level of parental distress, and estimates of pre-injury behavioral problems were also documented.

Results

The three groups did not differ on baseline characteristics (e.g. demographics and pre-injury behavioral problems for the mild TBI and OI groups) and level of parental distress. Mothers’ ratings of internalizing and externalizing behaviors were higher in the mild TBI group compared with the two control groups. Pre-injury behavioral problems and maternal distress were found to be significant predictors of outcome.

Conclusion

Our results show that even in its mildest form, preschool TBI may cause disruption to the immature brain serious enough to result in behavioral changes, which persist for several months post-injury.
Endogenous Participation
Authors: Falleti Tulia G. , Riofrancos Thea N.
Published: November 2017

Why and how do institutions strengthen? This article offers an explanation of institutional strength based on the study of participatory institutions. Combining the insights of historical institutionalism and participatory democracy literatures, the authors propose an endogenous theory of participation and argue that the strength of participatory institutions depends on the historic process of their creation and the subsequent political incorporation of the mobilized groups that bring them about. The authors comparatively study prior consultation in Bolivia and Ecuador since its inception in the 1990s. This institution is highly relevant in Latin America, particularly as countries in the region intensify the extraction of nonrenewable resources. The article shows that different paths of political incorporation of the groups mobilized for institutional adoption were consequential to the resulting institutional strength. The findings shed light on the tensions between participatory democracy and resource extraction in Latin America and have important implications for the study of participatory and political institutions worldwide.
Sit-to-stand and stand-to-sit assistance for paraplegic patients with CUHK-EXO exoskeleton
Authors: Chen Bing , Zhong Chun-Hao , Ma Hao , Guan Xiao , Qin Lai-Yin , Chan Kai-Ming , Law Sheung-Wai , Qin Ling , Liao Wei-Hsin
Published: November 2017

In this paper, we introduce a lower extremity exoskeleton CUHK-EXO that is developed to help paraplegic patients, who have lost the motor and sensory functions of their lower limbs to perform basic daily life motions. Since the sit-to-stand and stand-to-sit (STS) motion is the first step for paraplegic patients toward walking, analysis of the exoskeleton's applicability to the STS motion assistance is performed. First, the human-exoskeleton system (HES) is modeled as a five-link model during the STS motion, and the center of pressure (COP) on the ground and center of gravity of the whole system are calculated. Then, a description of the CUHK-EXO hardware design is presented, including the mechatronics design and actuator selection. The COP position is an important factor indicating system balance and wearer's comfort. Based on the COP position, a trajectory online modification algorithm (TOMA) is proposed for CUHK-EXO to counteract disturbances, stabilize system balance, and improve the wearer's comfort in the STS motion. The results of STS motion tests conducted with a paraplegic patient demonstrate that CUHK-EXO can provide a normal reference pattern and proper assistive torque to support the patient's STS motion. In addition, a pilot study is conducted with a healthy subject to verify the effectiveness of the proposed TOMA under external disturbances before future clinical trials. The testing results verify that CUHK-EXO can counteract disturbances, and help the wearer perform the STS motion safely and comfortably.
The magnitude of a graph
Authors: LEINSTER TOM
Published: November 2017

The magnitude of a graph is one of a family of cardinality-like invariants extending across mathematics; it is a cousin to Euler characteristic and geometric measure. Among its cardinality-like properties are multiplicativity with respect to cartesian product and an inclusion-exclusion formula for the magnitude of a union. Formally, the magnitude of a graph is both a rational function over ℚ and a power series over ℤ. It shares features with one of the most important of all graph invariants, the Tutte polynomial; for instance, magnitude is invariant under Whitney twists when the points of identification are adjacent. Nevertheless, the magnitude of a graph is not determined by its Tutte polynomial, nor even by its cycle matroid, and it therefore carries information that they do not.