bluuebunny/crossref_metadata_2025 huggingface dataset:
Horizontal soil water potential heterogeneity: simplifying approaches for crop water dynamics models
Authors: Couvreur V. , Vanderborght J. , Beff L. , Javaux M.
Published: May 2014

Abstract. Soil water potential (SWP) is known to affect plant water status, and even though observations demonstrate that SWP distribution around roots may limit plant water availability, its horizontal heterogeneity within the root zone is often neglected in hydrological models. As motive, using a horizontal discretisation significantly larger than one centimetre is often essential for computing time considerations, especially for large-scale hydrodynamics models. In this paper, we simulate soil and root system hydrodynamics at the centimetre scale and evaluate approaches to upscale variables and parameters related to root water uptake (RWU) for two crop systems: a densely seeded crop with an average uniform distribution of roots in the horizontal direction (winter wheat) and a wide-row crop with lateral variations in root density (maize). In a first approach, the upscaled water potential at soil–root interfaces was assumed to equal the bulk SWP of the upscaled soil element. Using this assumption, the 3-D high-resolution model could be accurately upscaled to a 2-D model for maize and a 1-D model for wheat. The accuracy of the upscaled models generally increased with soil hydraulic conductivity, lateral homogeneity of root distribution, and low transpiration rate. The link between horizontal upscaling and an implicit assumption on soil water redistribution was demonstrated in quantitative terms, and explained upscaling accuracy. In a second approach, the soil–root interface water potential was estimated by using a constant rate analytical solution of the axisymmetric soil water flow towards individual roots. In addition to the theoretical model properties, effective properties were tested in order to account for unfulfilled assumptions of the analytical solution: non-uniform lateral root distributions and transient RWU rates. Significant improvements were however only noticed for winter wheat, for which the first approach was already satisfying. This study confirms that the use of 1-D spatial discretisation to represent soil–plant water dynamics is a worthy choice for densely seeded crops. For wide-row crops, e.g. maize, further theoretical developments that better account for horizontal SWP heterogeneity might be needed in order to properly predict soil–plant hydrodynamics in 1-D.
Determining regional limits and sectoral constraints for water use under climate change
Authors: Lissner T. K. , Sullivan C. A. , Reusser D. E. , Kropp J. P.
Published: May 2014

Abstract. Water is an essential input to the majority of human activities. Often, access to sufficient water resources is limited by quality and infrastructure aspects, rather than by resource availability alone, and each activity has different requirements regarding the nature of these aspects. This paper develops an integrated approach to assess the adequacy of water resources for the three major water users, the domestic, agricultural and industrial sectors. Additionally, we include environmental water requirements. We first outline the main determinants of water adequacy for each sector. Subsequently, we present an integrated approach using fuzzy logic, with allows assessing sector-specific as well as overall water adequacy. We implement the approach in two case study settings to exemplify the main features of the approach. Using results from two climate models and two forcing RCPs (Representative Concentration Pathways) as well as population projections, we further assess the impacts of climate change and population growth on the adequacy of water resources. The results provide an important step forward in determining the most relevant factors, impeding adequate access to water, which remains an important challenge in many regions of the world. The methodology allows to directly identify those factors most decisive in determining the adequacy of water in each region, pointing towards the most efficient intervention points to improve conditions. Our findings underline the fact that in addition to water volumes, water quality is a limitation for all sectors and especially for the environmental sector, high levels of pollution are a threat to water adequacy.
Robust, multifunctional flood defenses in the Dutch rural riverine area
Authors: van Loon-Steensma J. M. , Vellinga P.
Published: May 2014

Abstract. This paper reviews the possible functions as well as strengths, weaknesses, opportunities, and threats for robust flood defenses in the rural riverine areas of the Netherlands on the basis of the recent literature and case studies at five locations in the Netherlands where dike reinforcement is planned. For each of the case studies semi-structured interviews with experts and stakeholders were conducted. At each of the five locations, suitable robust flood defenses could be identified that would contribute to the envisaged functions and ambitions for the respective areas. Primary strengths of a robust, multifunctional dike in comparison to a traditional dike appeared to be the more efficient space use due to the combination of different functions, a longer-term focus and greater safety.
A system-of-systems engineering approach to leadership and innovation: Sustainable STEM education and workforce development through the Smart Cities initiative
Authors: Karwowski Waldemar , Ahram Tareq , Amaba Ben
Published: May 2014

Given the most competitive nature of a global business environment today, an effective engineering management and leadership that supports innovation and entrepreneurship is a critical requirement for all levels of an organization. In view of the ever increasing complexity of contemporary urban systems and services they provide, it is important for planners and leaders to leverage individual and organizational learning processes to assure the highest levels of organizational performance. Development of engineering competence and leadership skills are also extremely important due to a general shortage of engineering talent and the need for mobility of highly trained professionals. Two factors emerge to have the greatest impact on growth and sustainability of the future smart cities and the variety of services they will be able to provide to their citizens: improving managerial, leadership and creative (innovative) skills of city employees, and integrating the concepts of the science, technology, engineering and mathematics (STEM) disciplines into the instructional training and development of the future smart city workforce. One of the most important factors for success of the above goal is integration of the complex adaptive systems engineering concepts into the smart city planning processes. This paper introduces a complex adaptive system-of-systems engineering approach to leadership and innovation by promoting sustainable STEM education and workforce development through the smart cities initiative. The core STEM leadership and innovation principles are integrated with systems engineering concepts for collaborative development of engineering skills and performance improvements in education, this is critical for modeling and design of the next generation sustainable smarter cities and services.
Grand Challenges of 21st-century engineering education
Authors: Ogmen Haluk
Published: May 2014

Our educational system needs to adapt to ever-changing scientific, industrial, economic, and social systems. However, since changes in the educational system have long-term repercussions, one has to apply care in preserving the relative stability of existing educational structures so that changes are adapted towards only those trends that have enduring and significant impact on society. At the turn of the 21st century, the U.S. National Academy of Engineering identified 14 engineering grand challenges for the 21st century. We discuss how undergraduate education can be shaped to address these grand challenges.
Perceptions of engineering students on industrial training in Malaysia
Authors: Phang Fatin Aliah , Yusof Khairiyah Mohd , Saat Maisarah Mat , Yusof Norazah Mohd
Published: May 2014

Industrial training or internship is an important part of a study program for an engineering student in all universities in Malaysia. This research explores the students' perception of their experience in industrial training, which includes the management of the industrial training at the universities, self-change, future career development and readiness to be an engineer. A questionnaire was given to 88 third-year engineering undergraduates from one public university and one private university, who had just undergone industrial training. The data was analyzed using descriptive and inferential statistics. The results show that the engineering students had moderate levels of perception on all the categories, except future career, which showed a low level of perception. This meant that they believed that industrial training had not given them the confidence that they will be able to obtain the future career they want in engineering. Another interesting finding of the research, through a correlational analysis (p < .05), shows that the longer the duration of industrial training, the higher the readiness and future career development among the engineering undergraduates. This may indicate that there is a need to lengthen the duration of industrial training during the study where the popular duration currently in most of the public universities is 10-12 weeks.
ICT in engineering educational content delivery: Challenges and opportunities
Authors: Ali Edriss Ahmed
Published: May 2014

Despite the attractive features of ICT in education, and the many advantages that successful use of these technological resources can offer to the education sector in general, their use in engineering educational content delivery is still lagging behind other educational disciplines. In this paper we look closely at the challenges that face full utilization of these technology resources in engineering educational content delivery, the great opportunities that ICT can offer, and actions that can be taken to overcome the challenges. The challenges are exemplified in: the quantitative nature of engineering discipline, lack of awareness of pedagogical use of ICT in education and the lack of clear policy of how and what type of engineering educational content delivery mode can benefit most from available ICT resources. Opportunities available for full utilization of ICT facilities are summarized in: the wide availability of computing resources, high speed internet access and general ICT knowhow among the young generations of both students and instructors among others. Actions to be taken for proper utilization of ICT resources in engineering education are given, and Blended Mode of learning, which combines face-to-face with online learning, is suggested as the most suitable mode for engineering educational content delivery.
Dialoguer, encore et toujours, avec les musulmans
Authors: Borrmans Maurice
Published: May 2014

Les Églises locales, en Europe, ont multiplié leurs institutions pour dialoguer avec les musulmans immigrés pour en développer toutes les possibilités : à côté de leurs fidèles engagés dans ce dialogue, beaucoup d’autres le critiquent ou le refusent pour mille raisons politiques ou culturelles, voire théologiques et spirituelles. Les papes Jean Paul II et Benoît XVI insistent sur la nécessité de le poursuivre « encore et toujours » au nom même de l’Évangile, malgré les difficultés du moment. Même l’incident de parcours que fut la conférence de Ratisbonne (12 septembre 2006) s’est révélé être une incitation à en approfondir les modalités et les limites. Quant à la Lettre des 138 personnalités musulmanes d’octobre 2007, riche en promesses, elle a été trop vite oubliée de part et d’autre. La Lettre du Cardinal Martini au peuple de Milan, de décembre 1990, est pourtant toujours d’actualité. Les chrétiens sont invités à rendre compte de leur foi, à bien connaître les musulmans et à leur faire découvrir les valeurs chrétiennes de la culture européenne. Tous doivent être réalistes dans leurs collaborations en y tenant compte des difficultés qu’il y a à « vivre ensemble » quand on appartient à des cultures différenciées : que chacun y fasse effort pour être plus proche de l’autre.
Beyond Extremism
Authors: Reynolds Thomas E.
Published: May 2014

Seeking to move beyond language of “extremism”, this article discusses some of the promises and perils of Muslim-Christian dialogue in an era after September 11, 2001. The author advocates for the public face of religion in secular societies, assesses several recent developments in Muslim-Christian engagements, and proposes steps for opening up a more fruitful contemporary collaboration between Muslims and Christians. Written from a Christian perspective, the article concludes by arguing for “dialogical openness” as a hopeful path toward interfaith mutuality.
Modernités concurrentes
Authors: Zathureczky Kornel , Houle Jacques-André
Published: May 2014

Cet article propose une évaluation critique des deux réponses d’envergure à « A Common Word » originaire de centres traditionnels de la chrétienté européenne. Dans les deux cas, la notion de bien commun joue un rôle central dans la détermination de la forme et de l’orientation de la coopération interreligieuse dans un contexte mondial. Alors que les réponses émanant du Vatican sont lues comme une expression de la pragmatique interreligieuse, la seconde, un engagement plus solide de Rowan Williams est présenté comme une tentative de développer une éthique interreligieuse de la communication. L’examen critique de ces deux visions de la solidarité interreligieuse conduit à des conclusions significatives quant à la notion d’autrui, une catégorie centrale partagée par toutes les traditions abrahamiques.
Les Églises de l’Orient arabe face à la mondialisation du dialogue islamo-chrétien
Authors: Daou Fadi
Published: May 2014

Cet article représente une étude comparative des programmes du dialogue interreligieux pour les musulmans et les chrétiens de l’Orient arabe. L’auteur défend la thèse que la période qui suit les attaques terroristes du 11 septembre 2001 voit une évolution majeure sur le plan du dialogue et pose de nouveaux défis pour ses protagonistes. L’entrée en force des grandes institutions politiques musulmanes, sur la scène du dialogue, le propulse en effet sur le plan mondial et inter-civilisationnel, sans pour autant résoudre ses enjeux locaux. Cette situation crée un décalage entre les attentes des chrétiens d’Orient face au dialogue — dialogue qui est vital pour leur présence et le maintien du « vivre ensemble » dans leurs sociétés —, et les attentes des musulmans qui cherchent à corriger par le dialogue l’image de l’islam qui est projetée mondialement. Ce décalage représente un enjeu, voire un risque pour l’avenir du dialogue au Moyen-Orient. Ce risque peut cependant être transformé en une circonstance favorable, suivant les hypothèses conclusives de l’auteur.
Théologies libanaises du dialogue islamo-chrétien
Authors: Chrabieh Pamela
Published: May 2014

Dans un contexte d’« hiver arabe », caractérisé par la guerre, la répression des libertés, les crises socio-économiques et la montée des extrémismes, il devient plus que crucial de mettre en avant les discours et les pratiques de dialogue, de convivialité et de construction de la paix au Liban, notamment théologiques. En ce sens, je présente dans cet article un aperçu des approches du métropolite grec-orthodoxe Georges Khodr et de l’érudit chiite Mahmoud Ayoub, lesquels font partie d’un courant que j’ai nommé « le courant de la culture du dialogue ». Khodr et Ayoub développent justement des théologies qui appellent, d’une part, à une certaine forme de séparation entre la politique et la religion, mais aussi, d’autre part, à l’implantation d’une « société pluraliste religieuse », formée de croyants en Dieu. Après avoir rappelé à grands traits le contexte libanais, je présente à deux reprises la pensée des auteurs : d’abord de manière globale, puis de manière plus analytique — par le biais conceptuel d’une théologie mystique et apophatique, mais aussi contextuelle et libérationniste (chez Khodr), et par le biais de l’al-iğtihād (chez Ayoub). Cela me permet, en conclusion, de montrer le front commun de leur combat, puis de cerner leurs apports et leurs limites respectives.
Le dialogue islamo-chrétien au Québec : quelques signes d’espérance
Authors: Amor Samia
Published: May 2014

Dans un contexte de mobilité humaine à l’échelle planétaire, l’implantation de l’islam au Québec est un fait de société qui entraîne une rupture avec la représentation classique des relations islamo-chrétiennes. On se demande comment envisager un renouvellement de la communication entre chrétiens et musulmans au Québec. Cette contribution s’attache à repérer les foyers de dialogue, ce qui rompt avec l’idée d’une absence de contact entre les deux communautés de croyants. Elle étudie la possibilité d’un Québec en tant qu’espace de dialogue, tout en s’interrogeant sur un cadre de référence pour un dialogue favorable à une cohésion sociale.
La série télévisée Little Mosque on the Prairie1 de Zarqa Nawaz et le discours de l’authenticité musulmane2
Authors: Greifenhagen Franz Volker
Published: May 2014

Mis au défi de se construire une identité religieuse viable, dans un contexte nord-américain où non seulement ils sont minoritaires et souvent membres de communautés immigrantes, mais où ils sont aussi victimes des stéréotypes négatifs courants, dans le discours politique et médiatique dominant, les musulmans empruntent souvent le discours de l’authenticité musulmane. Ce discours invoque notamment la distinction entre traditions culturelles, interprétées comme contextuelles et limitées, et « véritable islam », vu comme universel et éternel. Avec ce discours en toile de fond, le présent article analyse la série télévisée, Little Mosque on the Prairie, créée par Zarqa Nawaz. Plutôt que de rejeter les expressions culturelles de l’islam, l’oeuvre de Nawaz semble suggérer qu’une identité musulmane authentique, en tant que construction culturelle, peut s’acclimater en Amérique du Nord et, cela, en dépit des contre-discours, musulmans et non musulmans, qui représentent l’identité musulmane comme sans commune mesure avec les contextes culturels occidentaux.
Quasiperiodic VLF emissions with short‐period modulation and their relationship to whistlers: A case study
Authors: Manninen J. , Demekhov A. G. , Titova E. E. , Kozlovsky A. E. , Pasmanik D. L.
Published: May 2014

We study properties of quasiperiodic (QP) VLF emissions recorded on 24 December 2011 during the VLF campaign in northern Finland. The main attention is paid to interrelationships between different characteristic periods in the QP spectra. In particular, we analyze regular variations in the QP repetition intervals (1–10 min) during the event from 15:30 to 22 UT, their changes during substorms, and short periodic (several second) modulation observed within separate QP elements. We explained the variations of periods of QP emissions in terms of the model of auto‐oscillation regime of the cyclotron instability in the magnetosphere. During the considered event lasting about 7 h we observed a regular increase in the time intervals between the QP elements. We relate this increase with weakening of the magnetospheric source of energetic electrons. Significant variations in the QP period occurred during substorms. These variations can be due to a substorm‐related increase in the energetic‐electron flux and/or due to the precipitation of these electrons into the ionosphere which changes the reflection coefficient of VLF waves. We analyze the fine structure of QP element spectra and reveal the periods related to the time scales of guided propagation of whistler mode waves along the magnetic field line, which suggests that ducted propagation regime took place for the QP emissions. The periods were about 6–9 s for frequencies 1.2–4 kHz, respectively, which was similar to the period of almost simultaneously observed two‐hop whistlers. In the low‐frequency part of QP spectra periodic emissions with shorter periods of about 3 s were observed. Analysis of fine structure of QP elements shows that their formation is affected by both linear effects (i.e., group‐velocity dispersion) and quasi‐linear effects related to the modification of the energetic electron distribution function. It allows us to observe the transition from purely linear to quasi‐linear regime of wave‐particle interactions in the spectra of these short periodic emissions. The nonlinear regime can be understood in terms of passive mode locking in magnetospheric cyclotron maser.
Radar observations of MJO and Kelvin wave interactions during DYNAMO/CINDY2011/AMIE
Authors: DePasquale Amanda , Schumacher Courtney , Rapp Anita
Published: May 2014

Radar and sounding data collected during the Dynamics of the Madden‐Julian Oscillation (DYNAMO), the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 (CINDY2011), and the Atmospheric Radiation Measurement (ARM) Madden‐Julian Oscillation Investigation Experiment (AMIE) field campaigns in the equatorial Indian Ocean to study the initiation of the Madden‐Julian Oscillation (MJO) are used to examine the precipitation, cloud, and moisture characteristics during the MJO and convectively coupled Kelvin waves (KWs). Three MJO events and 10 KWs were identified from satellite data using different wave number frequency filters, although event identification varied based on the chosen range of latitude, frequency, and outgoing longwave radiation threshold. Radar and sounding data were composited for the three MJO events, four KWs during the active MJO, five KWs during the suppressed MJO, and one KW during the developing MJO. The MJO composite was generally consistent with past studies, although an increase in convective rain appeared to precede relative humidity increases at low‐ to middle‐levels. The active and developing MJO KWs produced more rain and cloud than suppressed MJO KWs and had a secondary peak in stratiform rain potentially associated with subsynoptic‐scale cloud clusters. The suppressed MJO KW composite displayed previously documented structure of vertical moisture buildup prior to the KW passage, whereas the developing MJO KW did not. The KW moisture signature during the active MJO was somewhat overwhelmed by the moist environment associated with the active MJO. Upper level moisture was enhanced after KW passage, regardless of MJO phase. However, upper level moisture was most enhanced after the developing MJO KW passage, providing deep tropospheric moisture that may have assisted MJO onset. Nonprecipitating upper level cloud and midlevel altocumulus/altostratus also persisted after most KW passages.
Physical simulation of atmospheric microbursts
Authors: Ferrero E. , Mortarini L. , Manfrin M. , Solari M. , Forza R.
Published: May 2014

A laboratory simulation of atmospheric microbursts is presented. The physical model of the atmospheric phenomenon is reproduced at a reduced scale in a rotating tank (TURLab, Italy), the similitude is based on the Froude number. Different experiments were carried out varying the Rossby number, and the analysis of four significant cases is presented. The velocity, vorticity, and turbulent kinetic energy fields are evaluated together with the swirling strength analysis. The comparison with the natural prototype is eventually shown and discussed.
Scales and drivers of temporal pCO2 dynamics in an Alpine stream
Authors: Peter Hannes , Singer Gabriel A. , Preiler Christian , Chifflard Peter , Steniczka Gertraud , Battin Tom J.
Published: May 2014

The role of inland waters for the global carbon cycle is now recognized and evidence increasingly suggests that stream ecosystems disproportionately contribute to the carbon cycle. Understanding the dynamics and drivers of stream water partial pressure of CO2 (pCO2) and CO2 evasion fluxes from streams to the atmosphere is imperative for assessing the role of climate change on the carbon cycle in stream ecosystems. Monitoring pCO2 over 3 years, we here report on the seasonal, diurnal, and event‐driven dynamics of pCO2 in the hyporheic zone and stream water of an Alpine stream and assess possible drivers of these dynamics. Our findings suggest that both catchment‐derived CO2 delivered by shallow groundwater into the stream and in‐stream respiration continuously build up pCO2 in the hyporheic zone. Depending on stream water temperature and assumedly on primary production (inferred from photosynthetically active radiation), hyporheic CO2 contributes to stream water pCO2 and ultimately to CO2 outgassing to the atmosphere. Diurnal patterns of stream water pCO2 increasingly built up during extended base flow and streambed‐scouring storms caused the collapse of these diurnal patterns. Post storm recovery of the diurnal pCO2 patterns was generally rapid. Our findings suggest that decreasing gas exchange velocity related to receding discharge drives recovery dynamics. We found that average CO2 outgassing fluxes during night exceeded those during day by up to 1.8 times. Our study highlights temperature and hydrology—key components of climate change—as major drivers of pCO2 dynamics in Alpine streams. They also underscore the necessity to consider day‐night differences in CO2 outgassing fluxes to properly establish carbon budgets and regional estimates of CO2 outgassing to the atmosphere.
Bayesian hierarchical approach and geophysical data sets for estimation of reactive facies over plume scales
Authors: Wainwright Haruko M. , Chen Jinsong , Sassen Douglas S. , Hubbard Susan S.
Published: May 2014

A stochastic model is developed to integrate multiscale geophysical and point data sets for characterizing coupled subsurface physiochemical properties over plume‐relevant scales, which is desired for parameterizing reactive transport models. We utilize the concept of reactive facies, which is based on the hypothesis that subsurface units can be identified that have distinct reactive‐transport‐property distributions. To estimate and spatially distribute reactive facies and their associated properties over plume‐relevant scales, we need to (1) document the physiochemical controls on plume behavior and the correspondence between geochemical, hydrogeological, and geophysical measurements; and (2) integrate multisource, multiscale data sets in a consistent manner. To tackle these cross‐scale challenges, we develop a hierarchical Bayesian model to jointly invert various wellbore and geophysical data sets that have different resolutions and spatial coverage. We use Markov‐chain Monte‐Carlo sampling methods to draw many samples from the joint posterior distribution and subsequently estimate the marginal posterior distribution of reactive‐facies field and their associated reactive transport properties. Synthetic studies demonstrate that our method can successfully integrate different types of data sets. We tested the framework using the data sets collected at the uranium‐contaminated Savannah River Site F‐Area, including wellbore lithology, cone penetrometer testing, and crosshole and surface seismic data. Results show that the method can estimate the spatial distribution of reactive facies and their associated reactive‐transport properties along a 300 m plume centerline traverse with high resolution (1.2 m by 0.305 m).
Scientists Focus on Land Subsidence Impacts on Coastal and Delta Cities
Authors: Showstack Randy
Published: May 2014

Some coastal and delta cities around the world are sinking but not necessarily due only to sea level rise and impacts from extreme weather events. Land subsidence that is caused by anthropogenic processes—including the extraction of groundwater, oil, and gas and the drainage of soils—is a significant concern for Jakarta, Indonesia; Manila, Philippines; New Orleans, La.; and many other coastal and delta cities, according to scientists at a 28 April briefing held at the European Geosciences Union's General Assembly in Vienna, Austria.
Advection of baroclinic eddies by depth mean flow
Authors: Klocker Andreas , Marshall David P.
Published: May 2014

Observed zonal propagation speeds of nonlinear eddies, derived using an eddy tracking algorithm, are compared with the classical long Rossby wave speed, Doppler shifted by just the depth mean velocity, the latter obtained from annual mean hydrography and an ocean atlas. Despite neglecting any Doppler shift from baroclinic background flows, the correspondence between observed eddy propagation speeds and theoretical long Rossby wave phase speeds is improved in the Antarctic Circumpolar Current region, where both show eastward propagation at speeds of 1–3 cm s−1, although the observed eastward eddy propagation speeds are systematically lower than the predicted Rossby wave phase speeds.
Discontinuities in the magnetic field near Enceladus
Authors: Simon Sven , Saur Joachim , van Treeck Shari C. , Kriegel Hendrik , Dougherty Michele K.
Published: May 2014

The plasma interaction of Saturn's icy moon Enceladus generates a hemisphere coupling current system that directly connects the giant planet's northern and southern polar magnetosphere. Based on Cassini magnetometer observations from all 20 targeted Enceladus flybys between 2004 and 2014, we study the magnetic field discontinuities associated with these hemisphere coupling currents. We identify a total number of 11 events during which the magnetic field was discontinuous at the surface of the Enceladus flux tube (defined by the bundle of magnetic field lines tangential to the solid body of the moon). A minimum variance analysis is applied to calculate the surface normals of these discontinuities. In agreement with theoretical expectations, the normals are found to be perpendicular to the surface of the Enceladus flux tube. The variation of the hemisphere coupling currents with Enceladean longitude leaves a clear imprint in the strengths of the observed magnetic field jumps as well.
Channel networks within lava flows: Formation, evolution, and implications for flow behavior
Authors: Dietterich Hannah R. , Cashman Katharine V.
Published: May 2014

New high‐resolution maps of Hawaiian lava flows highlight complex topographically controlled channel networks. Network geometries range from distributary systems dominated by branching around local obstacles, to tributary systems constricted by topography. We combine 2‐D network analysis tools developed for river systems and neural networks with 3‐D lidar morphologic analysis and historical records of flow emplacement to investigate both the origins of channel networks and their influence on flow morphology and behavior. We find that network complexity is a function of underlying slope and that the degree of flow branching, network connectivity, and longevity of individual channels all influence the final flow morphology (flow and channel widths and levee heights). Furthermore, because channel networks govern the distribution of lava supply within a flow, changes in the channel topology can dramatically alter the effective volumetric flux in any one branch, which affects both flow length and advance rate. Specifically, branching will slow and shorten flows, while merging can accelerate and lengthen them. Consideration of channel networks is thus important for predicting lava flow behavior and mitigating flow hazards with diversion barriers. Observed relationships between network geometry, flow parameters, and morphology also offer insight into the interpretation of these features elsewhere on Earth and other terrestrial planets.
Systematic Investigation of the Diffusion Welding Behavior of the Austenitic Stainless Steel 304 (1.4301)
Authors: Gietzelt Thomas , Toth Volker , Huell Andreas , Messerschmidt Florian , Dittmeyer Roland
Published: May 2014

The deformation behavior of SS 304 is investigated at three diffusion welding temperatures and different durations. Samples 100 mm in height consisting of five pieces and manufactured from pultrusion round stock are used for studying the diffusion across the bonding planes. The joining cross‐section varies from top to bottom covering bonding pressures from 15 to 25 MPa. From the results, a regression equation is derived allowing the calculation of expected deformation for any other temperature and duration within the investigated range. The approach is validated by an experiment with arbitrary temperature and welding duration. To study the influence of the grain size, orientation and passivation layers, a sample made of 51 sheets, 2 mm in thickness each, is diffusion welded and the results are compared.
Responsive Nanoporous Smectic Liquid Crystal Polymer Networks as Efficient and Selective Adsorbents
Authors: van Kuringen Huub P. C. , Eikelboom Geert M. , Shishmanova Ivelina K. , Broer Dirk J. , Schenning Albertus P. H. J.
Published: May 2014

An efficient and selective porous nanostructured polymer adsorbent is prepared from smectic liquid crystals. The adsorption study is performed by using hydrophilic dyes as water pollutants. The anionic pore interior of the nanoporous polymer is able to selectively adsorb cationic methylene blue over anionic methyl orange. Even zwitter ionic rhodamine B could hardly be adsorbed due to the presence of the anionic group in this dye. The confined pore dimensions allow size selective adsorption; a 4th generation cationic dendrimer is not able to diffuse into the nanometer sized pores. The porous nature of the polymer provides easy and fast accessibility of all adsorption sites. Stoichiometric ion exchange is obtained, which equates to an adsorption capacity of nearly 1 gram of methylene blue per 1 gram adsorbent. A competitive Langmuir adsorption constant and pseudo second order rate constant are determined. The adsorbent and adsorbate could both be retrieved after acid treatment of the polymer.
Testing hypothesized predictors of immune activation in tanzanian infants and children: Community, household, caretaker, and child effects
Authors: Hadley Craig , Decaro Jason A.
Published: May 2014

Objectives

There is increasing interest in the epidemiology of immune activation among young children because of the links with mortality and growth. We hypothesized that infant and child inflammation, as measured by elevated C‐reactive protein (CRP), would be associated with household assets, household size, measures of sanitation, and food insecurity. We also hypothesized that children in the poorest households and with elevated CRP would show evidence of growth faltering.

Methods

A nationally representative cross‐sectional study of Tanzania children 6–59 months of age. Survey data, anthropometrics, and dried blood spots were available for 1,387 children. Measures of elevated CRP (CRP ≥ 1.1 mg/l) were used to assess inflammation.

Results

Fifty‐four percent of the sample had CRP ≥ 1.1 mg/l. In bivariate analyses, several measures of sanitation were associated with elevated CRP but in multiple regression models only age, sex, literacy, maternal reports of illness, household size, and living in the wealthiest households predicted CRP. There were no associations between elevated CRP and any measure of child growth.

Conclusions

Among children in Tanzania, a single elevated CRP does not predict poor growth functioning. Elevated CRP is associated with individual, caretaker, household, and community‐level variables. Future work should strive to measure local biologies in more nuanced ways. Am. J. Hum. Biol. 26:523–529, 2014. © 2014 Wiley Periodicals, Inc.
Advanced bone age in a girl with Wiedemann–Steiner syndrome and an exonic deletion in KMT2A (MLL)
Authors: Mendelsohn Bryce A. , Pronold Melissa , Long Roger , Smaoui Nizar , Slavotinek Anne M.
Published: May 2014

Recognition of the gene implicated in a Mendelian disorder subsequently leads to an expansion of potential phenotypes associated with mutations in that gene as patients with features beyond the core phenotype are identified by sequencing. Here, we present a young girl with developmental delay, short stature despite a markedly advanced bone age, hypertrichosis without elbow hair, renal anomalies, and dysmorphic facial features, found to have a heterozygous, de novo, intragenic deletion encompassing exons 2–10 of the KMT2A (MLL) gene detected by whole exome sequencing. Heterozygous mutations in this gene were recently demonstrated to cause Wiedemann–Steiner syndrome (OMIM 605130). Importantly, retrospective analysis of this patient's chromosomal microarray revealed decreased copy number of two probes corresponding to exons 2 and 9 of the KMT2A gene, though this result was not reported by the testing laboratory in keeping with standard protocols for reportable size cutoffs for array comparative genomic hybridization. This patient expands the clinical phenotype associated with mutations in KMT2A to include variable patterns of hypertrichosis and a significantly advanced bone age with premature eruption of the secondary dentition despite her growth retardation. This patient also represents the first report of Wiedemann–Steiner syndrome due to an exonic deletion, supporting haploinsufficiency as a causative mechanism. Our patient also illustrates the need for sensitive guidelines for the reporting of chromosomal microarray findings that are below traditional reporting size cutoffs, but that impact exons or other genomic regions of known function. © 2014 Wiley Periodicals, Inc.
Synthesis of Tetrahydropyran/Tetrahydrofuran‐Containing Macrolides by Palladium‐Catalyzed Alkoxycarbonylative Macrolactonizations
Authors: Bai Yu , Davis Dexter C. , Dai Mingji
Published: May 2014

A novel Pd‐catalyzed cascade alkoxycarbonylative macrolactonization to construct tetrahydropyran/tetrahydrofuran‐containing bridged macrolactones in one step from alkendiols is described. Products with various ring sizes and substituents were obtained. Challenging macrolactones involving tertiary alcohols were synthesized smoothly as well. Mechanistically, experimental evidence to support a trans‐oxypalladation step has been provided. The method was applied to the synthesis of potent anticancer compound 9‐demethylneopeltolide.
Understanding review helpfulness as a function of reviewer reputation, review rating, and review depth
Authors: Chua Alton Y.K. , Banerjee Snehasish
Published: May 2014

This article examines review helpfulness as a function of reviewer reputation, review rating, and review depth. In drawing data from the popular review platform Amazon, results indicate that review helpfulness is positively related to reviewer profile and review depth but is negatively related to review rating. Users seem to have a proclivity for reviews contributed by reviewers with a positive track record. They also appreciate reviews with lambasting comments and those with adequate depth. By highlighting its implications for theory and practice, the article concludes with limitations and areas for further research.
Neural‐Adaptive Control and Nonlinear Observer for Waste‐To‐Energy Boilers
Authors: Mahmoodi Takaghaj S. , Macnab C.J.B. , Westwick D. , Boiko I.
Published: May 2014

This paper looks at the problem of controlling an incinerator that burns waste gas to generate power. The system is modelled as a standard utility boiler using one known and one unknown (waste) fuel input. Standard linear controls have trouble dealing with large variations in the waste input, and in practice boiler shutdowns can occur. In this work, a nonlinear adaptive control design accounts for uncertainty in the plant parameters, and an adaptive neural‐network estimates the effect of the waste input. Since a linear observer design cannot guarantee convergence away from a set point, a novel nonlinear observer design provides estimates of the states. The observer design uses fictitious states to estimate nonlinear terms in the observer dynamics. The analysis guarantees Lyapunov stability, thus the observer bounds depend on the accuracy of the observer initial conditions. Simulation results show the proposed method can obtain accurate performance and stability, improving over results obtained withproportional–integral control.
Amplifier Gain Tuning‐Based Slotine‐Li Adaptive Manipulator Control
Authors: Yih Chih‐Chen
Published: May 2014

Exploiting the linear parameterization and skew‐symmetric properties from the robot model, the Slotine‐Li adaptive control cannot directly be implemented in robot control because the control torque is produced by actuators with electrical drives and power amplifiers. Without considering the actuator dynamics and amplifier gains, the adaptive control can deteriorate in performance and the stability can be violated for the robot manipulators. This paper proposes a simple and novel approach that can represent the effects of actuators with electrical drives by a constant gain from the control signal to the torque and retain the Slotine‐Li adaptive control scheme by achieving a balance between actuator modeling and control implementation. Incorporating the adaptive tuning of the amplifier gain, we extend the adaptive control algorithm proposed by Slotine and Li. We explicitly define the error of amplifier gain, and we show from Lyapunov analysis that the estimation error is bounded. In the simulation, we numerically verify the effectiveness of our approach and the improved performance over the non‐adaptive amplifier gain algorithm.
Modest Impact on Risk for Autism Spectrum Disorder of Rare Copy Number Variants at 15q11.2, Specifically Breakpoints 1 to 2
Authors: Chaste Pauline , Sanders Stephan J. , Mohan Kommu N. , Klei Lambertus , Song Youeun , Murtha Michael T. , Hus Vanessa , Lowe Jennifer K. , Willsey A. Jeremy , Moreno‐De‐Luca Daniel , Yu Timothy W. , Fombonne Eric , Geschwind Daniel , Grice Dorothy E. , Ledbetter David H. , Lord Catherine , Mane Shrikant M. , Martin Donna M. , Morrow Eric M. , Walsh Christopher A. , Sutcliffe James S. , State Matthew W. , Martin Christa Lese , Devlin Bernie , Beaudet Arthur L. , Cook Edwin H. , Kim Soo‐Jeong
Published: May 2014

The proximal region of chromosome 15 is one of the genomic hotspots for copy number variants (CNVs). Among the rearrangements observed in this region,CNVsfrom the interval between the common breakpoints 1 and 2 (BP1 andBP2) have been reported cosegregating with autism spectrum disorder (ASD). Although evidence supporting an association betweenBP1‐BP2CNVsand autism accumulates, the magnitude of the effect ofBP1‐BP2CNVsremains elusive, posing a great challenge to recurrence‐risk counseling. To gain further insight into their pathogenicity forASD, we estimated the penetrance of theBP1‐BP2CNVsforASDas well as their effects onASD‐related phenotypes in a well‐characterizedASDsample (n = 2525 families). Transmission disequilibrium test revealed significant preferential transmission only for the duplicated chromosome in probands (20T:9NT). The penetrance of theBP1‐BP2CNVsforASDwas low, conferring additional risks of 0.3% (deletion) and 0.8% (duplication). Stepwise regression analyses suggest a greater effect of theCNVsonASD‐related phenotype in males and when maternally inherited. Taken together, the results are consistent withBP1‐BP2CNVsas risk factors for autism. However, their effect is modest, more akin to that seen for common variants. To be consistent with the currentAmericanCollege ofMedicalGenetics guidelines for interpretation of postnatalCNV, theBP1‐BP2 deletion and duplicationCNVswould probably best be classified as variants of uncertain significance (VOUS): they appear to have an impact on risk, but one so modest that theseCNVsdo not merit pathogenic status.Autism Res2014, 7: 355–362.© 2014 International Society for Autism Research, Wiley Periodicals, Inc.
Microbubble‐mediated sonoporation for highly efficient transfection of recalcitrant human B‐ cell lines
Authors: Ling Yong Charlene Li , Siak‐Wei Ow Dave , Tandiono Tandiono , Mei Heng Lisa Li , Kwok‐Keung Chan Ken , Ohl Claus‐Dieter , Klaseboer Evert , Ohl Siew‐Wan , Boon‐Hwa Choo1 Andre
Published: May 2014

Sonoporation has not been widely explored as a strategy for the transfection of heterologous genes into notoriously difficult‐to‐transfect mammalian cell lines such as B cells. This technology utilizes ultrasound to create transient pores in the cell membrane, thus allowing the uptake of extraneous DNA into eukaryotic and prokaryotic cells, which is further enhanced by cationic microbubbles. This study investigates the use of sonoporation to deliver a plasmid encoding green fluorescent protein (GFP) into three human B‐cell lines (Ramos, Raji, Daudi). A higher transfection efficiency (TE) of >42% was achieved using sonoporation compared with <3% TE using the conventional lipofectamine method for Ramos cells. Upon further antibiotic selection of the transfected population for two weeks, we successfully enriched a stable population of GFP‐positive Ramos cells (>70%). Using the same strategy, Raji and Daudi B cells were also successfully transfected and enriched to 67 and 99% GFP‐positive cells, respectively. Here, we present sonoporation as a feasible non‐viral strategy for stable and highly efficient heterologous transfection of recalcitrant B‐cell lines. This is the first demonstration of a non‐viral method yielding transfection efficiencies significantly higher (42%) than the best reported values of electroporation (30%) for Ramos B‐cell lines.
Effects of Metal Promotion on the Performance of CuZnAl Catalysts for Alcohol Synthesis
Authors: Beiramar Jorge M. , Griboval‐Constant Anne , Khodakov Andrei Y.
Published: May 2014

A series of CuZnAl catalysts modified with different promoters (Fe, Co, Ru, Zr, Mo, Mg, Mn, and Cr) have been prepared through co‐precipitation, characterised by applying a combination of techniques, and tested for carbon monoxide hydrogenation. Cu reducibility in CuZnAl catalysts was affected by the addition of promoters. The ease of Cu reduction in the promoted catalysts leads to more active catalysts for the hydrogenation of carbon monoxide and the production of C2+ alcohols, whereas lower catalytic activity was observed over less reducible catalysts. The promotion of CuZnAl catalysts even with small amounts of Cr, Mn, and Fe resulted in a significant modification in the reaction selectivity. The Fe‐containing catalyst demonstrated a dramatic increase in carbon monoxide conversion and C2+ alcohol productivity (30 mg g${{{- 1\hfill \atop {\rm cat}\hfill}}}$ h−1).
Application of the Electrodiffusion Method to Measure Wall Shear Stress: Integrating Theory and Practice
Authors: Böhm Lutz , Jankhah Sepideh , Tihon Jaroslav , Bérubé Pierre R. , Kraume Matthias
Published: May 2014

The electrodiffusion method has been used in fluid dynamic research for the past 50 years. It allows the measurement of wall shear stress, a crucial parameter, e.g., for the cleaning of membrane modules used in water filtration. Various authors have published articles dealing with the theory behind this technique. But no paper collects all the knowledge assembled over five decades of application. Here, comprehensive summary of the theory of steady flow, unsteady flow, and transient voltage step experiments is given. Factors influencing the accuracy of the measurements are discussed. Furthermore, a new approach to calibrate the system from voltage step experiments is introduced, and practical issues related to its application in flow measurements are discussed for an exemplary signal response to a near‐wall flow.
Stabilizing Lead Cathodes with Diammonium Salt Additives in the Deoxygenation of Aromatic Amides
Authors: Edinger Carolin , Grimaudo Valentine , Broekmann Peter , Waldvogel Siegfried R.
Published: May 2014

Lead is efficiently protected against cathodic corrosion by the addition of diammonium salts in the electrolyte. The cationic coating of the cathode allows the efficient electroreduction of benzamides to benzylamines. The electrochemical deoxygenation of the amide is achieved without the use of oxophilic agents or sacrificial anodes. The surface of the lead cathode stays smooth and the cathode can be reused for multiple runs, providing <2.5 ppm of the crude product. Cyclic voltammetry studies reveal a shift in the onset potential of the hydrogen evolution reaction by −157 mV.