bluuebunny/crossref_metadata_2025 huggingface dataset:
New Exact Solutions of the New Hamiltonian Amplitude-Equation and Fokas Lenells Equation
Authors: Demiray Seyma , Bulut Hasan
Published: August 2015

In this paper, exact solutions of the new Hamiltonian amplitude equation and Fokas-Lenells equation are successfully obtained. The extended trial equation method (ETEM) and generalized Kudryashov method (GKM) are applied to find several exact solutions of the new Hamiltonian amplitude equation and Fokas-Lenells equation. Primarily, we seek some exact solutions of the new Hamiltonian amplitude equation and Fokas-Lenells equation by using ETEM. Then, we research dark soliton solutions of the new Hamiltonian amplitude equation and Fokas-Lenells equation by using GKM. Lastly, according to the values of some parameters, we draw two and three dimensional graphics of imaginary and real values of certain solutions found by utilizing both methods.
Combined X-ray and Raman Studies on the Effect of Cobalt Additives on the Decomposition of Magnesium Borohydride
Authors: Zavorotynska Olena , Deledda Stefano , Vitillo Jenny , Saldan Ivan , Guzik Matylda , Baricco Marcello , Walmsley John , Muller Jiri , Hauback Bjørn
Published: August 2015

Magnesium borohydride (Mg(BH4)2) is one of the most promising hydrogen storage materials. Its kinetics of hydrogen desorption, reversibility, and complex reaction pathways during decomposition and rehydrogenation, however, present a challenge, which has been often addressed by using transition metal compounds as additives. In this work the decomposition of Mg(BH4)2 ball-milled with CoCl2 and CoF2 additives, was studied by means of a combination of several in-situ techniques. Synchrotron X-ray diffraction and Raman spectroscopy were used to follow the phase transitions and decomposition of Mg(BH4)2. By comparison with pure milled Mg(BH4)2, the temperature for the γ → ε phase transition in the samples with CoF2 or CoCl2 additives was reduced by 10–45 °C. In-situ Raman measurements showed the formation of a decomposition phase with vibrations at 2513, 2411 and 766 cm−1 in the sample with CoF2. Simultaneous X-ray absorption measurements at the Co K-edge revealed that the additives chemically transformed to other species. CoF2 slowly reacted upon heating till ~290 °C, whereas CoCl2 transformed drastically at ~180 °C.
Blade Fault Diagnosis in Small Wind Power Systems Using MPPT with Optimized Control Parameters
Authors: Chen Jui-Ho , Hung Weir
Published: August 2015

A systematic experiment verification of Chaos Embedded Sliding Mode Extremum Seeking Control for maximum power point tracking and a method for detecting possible faults in small wind turbine systems in advance are proposed in this paper. The chaotic logistic map is used to replace the random function in the particle swarm optimization algorithm for faster searching the optimal control parameter . From the experimental results, it is verified that the Chaos Embedded Sliding Mode Extremum Seeking Control scheme has a better dynamic response than traditional Extremum Seeking Control scheme and Hill-Climbing Search scheme for maximum power point tracking. In the proposed scheme for fault detection, a chaotic synchronization method is used to transform the maximum power point tracking signal into a chaos synchronization error distribution diagram. It is then taken as the characteristic for fault diagnosis purposes. Finally, an extension theory pattern recognition technique is applied to diagnose the fault. Notably, the use of the chaotic dynamic errors as the fault diagnosis characteristic reduces the number of extracted features required, and therefore greatly reduces both the computation time and the hardware implementation cost. From the experimental results, it is shown that the fault diagnosis rate of the proposed method exceeds 98% not only in non-real-time but also in real-time of faults detection of the blades.
Food Safety in Low and Middle Income Countries
Authors: Grace Delia
Published: August 2015

Evidence on foodborne disease (FBD) in low and middle income countries (LMICs) is still limited, but important studies in recent years have broadened our understanding. These suggest that developing country consumers are concerned about FBD; that most of the known burden of FBD disease comes from biological hazards; and, that most FBD is the result of consumption of fresh, perishable foods sold in informal markets. FBD is likely to increase in LMICs as the result of massive increases in the consumption of risky foods (livestock and fish products and produce) and lengthening and broadening value chains. Although intensification of agricultural production is a strong trend, so far agro-industrial production and modern retail have not demonstrated clear advantages in food safety and disease control. There is limited evidence on effective, sustainable and scalable interventions to improve food safety in domestic markets. Training farmers on input use and good practices often benefits those farmers trained, but has not been scalable or sustainable, except where good practices are linked to eligibility for export. Training informal value chain actors who receive business benefits from being trained has been more successful. New technologies, growing public concern and increased emphasis on food system governance can also improve food safety.
Analyzing Trends in Software Product Lines Evolution Using aCladistics Based Approach
Authors: Benlarabi Anissa , Khtira Amal , Asri Bouchra
Published: August 2015

A software product line is a complex system the aim of which is to provide a platform dedicated to large reuse. It necessitates a great investment. Thus, its ability to cope with customers’ ever-changing requirements is among its key success factors. Great effort has been made to deal with the software product line evolution. In our previous works, we carried out a classification of these works to provide an overview of the used techniques. We also identified the following key challenges of software product lines evolution: the ability to predict future changes, the ability to define the impact of a change easily and the improvement in understanding the change. We have already tackled the second and the third challenges. The objective of this paper is to deal with the first challenge. We use the cladistics classification which was used in biology to understand the evolution of organisms sharing the same ancestor and their process of descent at the aim of predicting their future changes. By analogy, we consider a population of applications for media management on mobile devices derived from the same platform and we use cladistics to construct their evolutionary tree. We conducted an analysis to show how to identify the evolution trends of the case study products and to predict future changes.
Processing, Structural Characterization and Comparative Studies on Uniaxial Tensile Properties of a New Type of Porous Twisted Wire Material
Authors: Wu Fei , Zhou Zhaoyao , Duan Liuyang , Xiao Zhiyu
Published: August 2015

A self-developed rotary multi-cutter device cuts stainless steel wire ropes into segments to fabricate twisted wires. Stainless steel porous twisted wire materials (PTWMs) with a spatial composite intertexture structure are produced by the compaction and subsequent vacuum solid-phase sintering of twisted wires. The stainless steel PTWMs show two types of typical uniaxial tensile failure modes, i.e., a 45° angle fracture mode and an auxetic failure mode (the PTWMs expand along the direction perpendicular to the tension). The effects of the sintering parameters, porosities, wire diameters, and sampling direction on the tensile properties of the PTWMs are carefully investigated. By increasing the sintering temperature from 1130 °C to 1330 °C, the tensile strength of the PTWMs with 70% target porosity increased from 7.7 MPa to 28.6 MPa and the total failure goes down to 50%. When increasing the sintering time from 90 min to 150 min, the tensile strength increases from 12.4 MPa to 19.1 MPa and the total failure elongation drops to 78.6%. The tensile strength of the PTWMs increases from 28.9 MPa to 112.7 MPa with decreasing porosity from 69.5% to 46.0%, and the total failure elongation also increases from 14.8% to 40.7%. The tensile strength and the failure strain of the PTWMs with fine wires are higher than those of the PTWMs with coarse wires under the same porosity. Sampling direction has a small influence on the tensile properties of the PTWMs.
Influence of Flame Retardants on the Melt Dripping Behaviour of Thermoplastic Polymers
Authors: Matzen Melissa , Kandola Baljinder , Huth Christian , Schartel Bernhard
Published: August 2015

Melt flow and dripping of the pyrolysing polymer melt can be both a benefit and a detriment during a fire. In several small-scale fire tests addressing the ignition of a defined specimen with a small ignition source, well-adjusted melt flow and dripping are usually beneficial to pass the test. The presence of flame retardants often changes the melt viscosity crucially. The influence of certain flame retardants on the dripping behaviour of four commercial polymers, poly(butylene terephthalate) (PBT), polypropylene (PP), polypropylene modified with ethylene-propylene rubber (PP-EP) and polyamide 6 (PA 6), is analysed based on an experimental monitoring of the mass loss due to melt dripping, drop size and drop temperature as a function of the furnace temperature applied to a rod-shaped specimen. Investigating the thermal transition (DSC), thermal and thermo-oxidative decomposition, as well as the viscosity of the polymer and collected drops completes the investigation. Different mechanisms of the flame retardants are associated with their influence on the dripping behaviour in the UL 94 test. Reduction in decomposition temperature and changed viscosity play a major role. A flow limit in flame-retarded PBT, enhanced decomposition of flame-retarded PP and PP-EP and the promotion of dripping in PA 6 are the salient features discussed.
Separation and Recycling for Rare Earth Elements by Homogeneous Liquid-Liquid Extraction (HoLLE) Using a pH-Responsive Fluorine-Based Surfactant
Authors: Saito Shotaro , Ohno Osamu , Igarashi Shukuro , Kato Takeshi , Yamaguchi Hitoshi
Published: August 2015

A selective separation and recycling system for metal ions was developed by homogeneous liquid-liquid extraction (HoLLE) using a fluorosurfactant. Sixty-two different elemental ions (e.g., Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Hg, Ho, In, Ir, La, Lu, Mg, Mn, Mo, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Re, Rh, Ru, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W, Y, Yb, Zn, and Zr) were examined. By changing pH from a neutral or alkaline solution (pH ≥ 6.5) to that of an acidic solution (pH < 4.0), gallium, zirconium, palladium, silver, platinum, and rare earth elements were extracted at >90% efficiency into a sedimented Zonyl FSA® (CF3(CF2)n(CH2)2S(CH2)2COOH, n = 6–8) liquid phase. Moreover, all rare earth elements were obtained with superior extraction and stripping percentages. In the recycling of rare earth elements, the sedimented phase was maintained using a filter along with a mixed solution of THF and 1 M sodium hydroxide aqueous solution. The Zonyl FSA® was filtrated and the rare earth elements were recovered on the filter as a hydroxide. Furthermore, the filtrated Zonyl FSA was reusable by conditioning the subject pH.
Identification of N-Acetyldopamine Dimers from the Dung Beetle Catharsius molossus and Their COX-1 and COX-2 Inhibitory Activities
Authors: Lu Juan , Sun Qin , Tu Zheng-Chao , Lv Qing , Shui Pi-Xian , Cheng Yong-Xian
Published: August 2015

Recent studies focusing on identifying the biological agents of Catharsius molossus have led to the identification of three new N-acetyldopamine dimers molossusamide A–C (1-3) and two known compounds 4 and 5. The structures of the new compounds were identified by comprehensive spectroscopic evidences. Compound 4 was found to have inhibitory effects towards COX-1 and COX-2.
Molecular Cloning and Characterization of a Xanthone Prenyltransferase from Hypericum calycinum Cell Cultures
Authors: Fiesel Tobias , Gaid Mariam , Müller Andreas , Bartels Joana , El-Awaad Islam , Beuerle Till , Ernst Ludger , Behrends Sönke , Beerhues Ludger
Published: August 2015

In plants, prenylation of metabolites is widely distributed to generate compounds with efficient defense potential and distinct pharmacological activities profitable to human health. Prenylated compounds are formed by members of the prenyltransferase (PT) superfamily, which catalyze the addition of prenyl moieties to a variety of acceptor molecules. Cell cultures of Hypericum calycinum respond to elicitor treatment with the accumulation of the prenylated xanthone hyperxanthone E. A cDNA encoding a membrane-bound PT (HcPT) was isolated from a subtracted cDNA library and transcript preparations of H. calycinum. An increase in the HcPT transcript level preceded hyperxanthone E accumulation in cell cultures of H. calycinum treated with elicitor. The HcPT cDNA was functionally characterized by expression in baculovirus-infected insect cells. The recombinant enzyme catalyzed biosynthesis of 1,3,6,7-tetrahydroxy-8-prenylxanthone through regiospecific C–8 prenylation of 1,3,6,7-tetrahydroxyxanthone, indicating its involvement in hyperxanthone E formation. The enzymatic product shared significant structural features with the previously reported cholinesterase inhibitor γ-mangostin. Thus, our findings may offer a chance for semisynthesis of new active agents to be involved in the treatment of Alzheimer’s disease.
Ascorbic Acid-Initiated Tandem Radical Cyclization of N-Arylacrylamides to Give 3,3-Disubstituted Oxindoles
Authors: Liu Sheng , Cheng Pi , Liu Wei , Zeng Jian-Guo
Published: August 2015

An ascorbic acid-promoted and metal-free tandem room temperature cyclization of N-arylacrylamides with 4-nitrobenzenediazonium generated in situ was developed. This reaction proceeds smoothly through a radical mechanism and provides an environmentally friendly alternative approach to biologically active 3-alkyl-3-benzyloxindoles, avoiding the use of excess oxidants and light irradiation.
Comparison of the in Vitro Uptake and Toxicity of Collagen- and Synthetic Polymer-Coated Gold Nanoparticles
Authors: Marisca Oana , Kantner Karsten , Pfeiffer Christian , Zhang Qian , Pelaz Beatriz , Leopold Nicolae , Parak Wolfgang , Rejman Joanna
Published: August 2015

We studied the physico-chemical properties (size, shape, zeta-potential), cellular internalization and toxicity of gold nanoparticles (NPs) stabilized with the most abundant mammalian protein, collagen. The properties of these gold NPs were compared to the same sized gold NPs coated with synthetic poly(isobutylene-alt-maleic anhydride) (PMA). Intracellular uptake and cytotoxicity were assessed in two cell lines (cervical carcinoma and lung adenocarcinoma cells) by employing inductively-coupled plasma-mass spectrometry (ICP-MS) analysis and a cell viability assay based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), respectively. We found that the collagen-coated gold NPs exhibit lower cytotoxicity, but higher uptake levels than PMA-coated gold NPs. These results demonstrate that the surface coating of Au NPs plays a decisive role in their biocompatibility.
Association between Serum Copper Status and Working Memory in Schoolchildren
Authors: Zhou Guoping , Ji Xiaopeng , Cui Naixue , Cao Siyuan , Liu Chang , Liu Jianghong
Published: August 2015

Trace elements such as copper are essential micronutrients. Traditionally, copper has been studied in the context of micronutrient deficiencies. Recent studies in both animals and humans, however, have revealed that elevated blood copper can also have adverse effects on cognitive function since free copper can cross the blood-brain barrier and subsequently impose oxidative stress to neuronal cells. However, most of these human studies were conducted in adult populations with and without cognitive decline, and there are few studies on the effect of excess copper on cognitive function in children. This project seeks to look at the effects of elevated copper levels on cognitive development in a population of school age children (ages 10–14 years with mean age of 12.03 years and standard deviation (SD) of 0.44) from Jintan, China. Briefly, serum copper levels and working memory test scores were collected from a sample of 826 children with a mean serum copper level of 98.10 (SD 0.75). Copper level was considered as a categorical variable (taking the first group as those with as ≤84.3 μg/dL, the second group as >84.3 and ≤110.4 μg/dL, and the third group as >110.4 μg/dL with the cut-off values defined by the first and third quartiles of the sample). Results showed a significant association between high copper levels (>110.4 μg/dL) and poorer working memory in boys but this association was not seen in lower copper levels in either sex. These results suggests that in school age children, like in adults, elevated copper levels have the potential to adversely affect cognition.
Four-Wave Mixing of a Laser and Its Frequency-Doubled Version in a Multimode Optical Fiber
Authors: Pourbeyram Hamed , Mafi Arash
Published: August 2015

It is shown that it is possible to couple a laser beam and its frequency-doubled daughter into a multimode optical fiber through the four-wave mixing nonlinear process and generate a new wavelength. The frequency-doubled daughter can be generated in an external crystal with a large second order nonlinearity. It is argued that while this possibility is within the design parameter range of conventional multimode optical fibers, it necessitates a lower-bound for the core-cladding refractive index contrast of the multimode optical fiber.
Groundwater Quality Changes in a Karst Aquifer of Northeastern Wisconsin, USA: Reduction of Brown Water Incidence and Bacterial Contamination Resulting from Implementation of Regional Task Force Recommendations
Authors: Erb Kevin , Ronk Eric , Koundinya Vikram , Luczaj John
Published: August 2015

In the Silurian Dolostone region of eastern Wisconsin, the combination of thin soils and waste application (animal manure, organic waste) has led to significant groundwater contamination, including Brown Water Incidents (BWIs—contamination resulting in a color or odor change in well water) and detections of pathogen indicator bacteria such as E. coli and others. In response, a Karst Task Force (KTF) was convened to identify risks and recommend solutions. This article looks at the impact eight years after the 2007 Karst Task Force report—both the actions taken by local resource managers and the changes to water quality. We present the first regional analysis of the 2007 Karst Task Force report and subsequent regulatory changes to determine if these regulations impacted the prevalence of wells contaminated with animal waste and the frequency of BWIs. While all of the counties in the KTF area promoted increased awareness, landowner/manager and waste applicator education alone did not result in a drop in BWIs or other water quality improvements. The two counties in the study that adopted winter manure spreading restrictions on frozen or snow-covered ground showed statistically significant reductions in the instances of BWIs and other well water quality problems.
Prediction of Canopy Heights over a Large Region Using Heterogeneous Lidar Datasets: Efficacy and Challenges
Authors: Gopalakrishnan Ranjith , Thomas Valerie , Coulston John , Wynne Randolph
Published: August 2015

Generating accurate and unbiased wall-to-wall canopy height maps from airborne lidar data for large regions is useful to forest scientists and natural resource managers. However, mapping large areas often involves using lidar data from different projects, with varying acquisition parameters. In this work, we address the important question of whether one can accurately model canopy heights over large areas of the Southeastern US using a very heterogeneous dataset of small-footprint, discrete-return airborne lidar data (with 76 separate lidar projects). A unique aspect of this effort is the use of nationally uniform and extensive field data (~1800 forested plots) from the Forest Inventory and Analysis (FIA) program of the US Forest Service. Preliminary results are quite promising: Over all lidar projects, we observe a good correlation between the 85th percentile of lidar heights and field-measured height (r = 0.85). We construct a linear regression model to predict subplot-level dominant tree heights from distributional lidar metrics (R2 = 0.74, RMSE = 3.0 m, n = 1755). We also identify and quantify the importance of several factors (like heterogeneity of vegetation, point density, the predominance of hardwoods or softwoods, the average height of the forest stand, slope of the plot, and average scan angle of lidar acquisition) that influence the efficacy of predicting canopy heights from lidar data. For example, a subset of plots (coefficient of variation of vegetation heights <0.2) significantly reduces the RMSE of our model from 3.0–2.4 m (~20% reduction). We conclude that when all these elements are factored into consideration, combining data from disparate lidar projects does not preclude robust estimation of canopy heights.
A Combination of Genetic Algorithm and Particle Swarm Optimization for Vehicle Routing Problem with Time Windows
Authors: Xu Sheng-Hua , Liu Ji-Ping , Zhang Fu-Hao , Wang Liang , Sun Li-Jian
Published: August 2015

A combination of genetic algorithm and particle swarm optimization (PSO) for vehicle routing problems with time windows (VRPTW) is proposed in this paper. The improvements of the proposed algorithm include: using the particle real number encoding method to decode the route to alleviate the computation burden, applying a linear decreasing function based on the number of the iterations to provide balance between global and local exploration abilities, and integrating with the crossover operator of genetic algorithm to avoid the premature convergence and the local minimum. The experimental results show that the proposed algorithm is not only more efficient and competitive with other published results but can also obtain more optimal solutions for solving the VRPTW issue. One new well-known solution for this benchmark problem is also outlined in the following.
Saliency-Guided Detection of Unknown Objects in RGB-D Indoor Scenes
Authors: Bao Jiatong , Jia Yunyi , Cheng Yu , Xi Ning
Published: August 2015

This paper studies the problem of detecting unknown objects within indoor environments in an active and natural manner. The visual saliency scheme utilizing both color and depth cues is proposed to arouse the interests of the machine system for detecting unknown objects at salient positions in a 3D scene. The 3D points at the salient positions are selected as seed points for generating object hypotheses using the 3D shape. We perform multi-class labeling on a Markov random field (MRF) over the voxels of the 3D scene, combining cues from object hypotheses and 3D shape. The results from MRF are further refined by merging the labeled objects, which are spatially connected and have high correlation between color histograms. Quantitative and qualitative evaluations on two benchmark RGB-D datasets illustrate the advantages of the proposed method. The experiments of object detection and manipulation performed on a mobile manipulator validate its effectiveness and practicability in robotic applications.
Multi-Sensor Detection with Particle Swarm Optimization for Time-Frequency Coded Cooperative WSNs Based on MC-CDMA for Underground Coal Mines
Authors: Xu Jingjing , Yang Wei , Zhang Linyuan , Han Ruisong , Shao Xiaotao
Published: August 2015

In this paper, a wireless sensor network (WSN) technology adapted to underground channel conditions is developed, which has important theoretical and practical value for safety monitoring in underground coal mines. According to the characteristics that the space, time and frequency resources of underground tunnel are open, it is proposed to constitute wireless sensor nodes based on multicarrier code division multiple access (MC-CDMA) to make full use of these resources. To improve the wireless transmission performance of source sensor nodes, it is also proposed to utilize cooperative sensors with good channel conditions from the sink node to assist source sensors with poor channel conditions. Moreover, the total power of the source sensor and its cooperative sensors is allocated on the basis of their channel conditions to increase the energy efficiency of the WSN. To solve the problem that multiple access interference (MAI) arises when multiple source sensors transmit monitoring information simultaneously, a kind of multi-sensor detection (MSD) algorithm with particle swarm optimization (PSO), namely D-PSO, is proposed for the time-frequency coded cooperative MC-CDMA WSN. Simulation results show that the average bit error rate (BER) performance of the proposed WSN in an underground coal mine is improved significantly by using wireless sensor nodes based on MC-CDMA, adopting time-frequency coded cooperative transmission and D-PSO algorithm with particle swarm optimization.
Enhanced Dibutyl Phthalate Sensing Performance of a Quartz Crystal Microbalance Coated with Au-Decorated ZnO Porous Microspheres
Authors: Zhang Kaihuan , Fan Guokang , Hu Ruifen , Li Guang
Published: August 2015

Noble metals addition on nanostructured metal oxides is an attractive way to enhance gas sensing properties. Herein, hierarchical zinc oxide (ZnO) porous microspheres decorated with cubic gold particles (Au particles) were synthesized using a facile hydrothermal method. The as-prepared Au-decorated ZnO was then utilized as the sensing film of a gas sensor based on a quartz crystal microbalance (QCM). This fabricated sensor was applied to detect dibutyl phthalate (DBP), which is a widely used plasticizer, and its coating load was optimized. When tested at room temperature, the sensor exhibited a high sensitivity of 38.10 Hz/ppb to DBP in a low concentration range from 2 ppb to 30 ppb and the calculated theoretical detection limit is below 1 ppb. It maintains good repeatability as well as long-term stability. Compared with the undecorated ZnO based QCM, the Au-decorated one achieved a 1.62-time enhancement in sensitivity to DBP, and the selectivity was also improved. According to the experimental results, Au-functionalized ZnO porous microspheres displayed superior sensing performance towards DBP, indicating its potential use in monitoring plasticizers in the gaseous state. Moreover, Au decoration of porous metal oxide nanostructures is proved to be an effective approach for enhancing the gas sensing properties and the corresponding mechanism was investigated.
Designing an Optimal Subsidy Scheme to Reduce Emissions for a Competitive Urban Transport Market
Authors: Qin Feifei , Zhang Xiaoning
Published: August 2015

With the purpose of establishing an effective subsidy scheme to reduce Greenhouse Gas (GHG) emissions, this paper proposes a two-stage game for a competitive urban transport market. In the first stage, the authority determines operating subsidies based on social welfare maximization. Observing the predetermined subsidies, two transit operators set fares and frequencies to maximize their own profits at the second stage. The detailed analytical and numerical analyses demonstrate that of the three proposed subsidy schemes, the joint implementation of trip-based and frequency-related subsidies not only generates the largest welfare gains and makes competitive operators provide equilibrium fares and frequencies, which largely resemble first-best optimal levels but also greatly contributes to reducing Greenhouse Gas (GHG) emissions on major urban transport corridors.
Hybrid Metric-Palatini Gravity
Authors: Capozziello Salvatore , Harko Tiberiu , Koivisto Tomi , Lobo Francisco , Olmo Gonzalo
Published: August 2015

Recently, the phenomenology of f(R) gravity has been scrutinized. This scrutiny has been motivated by the possibility to account for the self-accelerated cosmic expansion without invoking dark energy sources. Besides, this kind of modified gravity is capable of addressing the dynamics of several self-gravitating systems alternatively to the presence of dark matter. It has been established that both metric and Palatini versions of these theories have interesting features but also manifest severe and different downsides. A hybrid combination of theories, containing elements from both these two formalisms, turns out to be also very successful accounting for the observed phenomenology and is able to avoid some drawbacks of the original approaches. This article reviews the formulation of this hybrid metric-Palatini approach and its main achievements in passing the local tests and in applications to astrophysical and cosmological scenarios, where it provides a unified approach to the problems of dark energy and dark matter.
Estimating the Rainwater Potential per Household in an Urban Area: Case Study in Central Mexico
Authors: Lizárraga-Mendiola Liliana , Vázquez-Rodríguez Gabriela , Blanco-Piñón Alberto , Rangel-Martínez Yamile , González-Sandoval María
Published: August 2015

In cities with problems of aridity and a shortage of drinking water supply, there is an urgent need to establish alternatives for an adequate water management program. This study proposes an estimation through which users can select a rainwater harvesting system for non-drinking water consumption. For the cities of Pachuca and Mineral de la Reforma, State of Hidalgo, Central Mexico, the historical record of rainfall analyzed covers a period of 33 years (1980–2013). We calculated the monthly volume of rainwater harvestable from roof areas (VR, m3) with household roof areas (Hra) of 45 m2, 50 m2, 100 m2 and 200 m2. It is proposed to replace in each single house the flush toilets and washing machine with ecological devices with consumptions of 4.8 L/flush and 70 L/load, respectively. Furthermore, a maximum and a minimum consumption of eight and six flushes/day/person (flush toilets) and five and four loads/week (washing machine), respectively, are proposed. From these considerations, our estimations of the harvestable rainwater showed that households with Hra of 45 m2 and 50 m2 would depend on the water supply system of the public network during part of the year. On the other hand, households with Hra of 100 m2 and 200 m2 might be able to store enough water to meet other needs besides toilet flushing and laundry.
Water Security in the Syr Darya Basin
Authors: Wegerich Kai , Van Rooijen Daniel , Soliev Ilkhom , Mukhamedova Nozilakhon
Published: August 2015

The importance of water security has gained prominence on the international water agenda, but the focus seems to be directed towards water demand. An essential element of water security is the functioning of public organizations responsible for water supply through direct and indirect security approaches. Despite this, there has been a tendency to overlook the water security strategies of these organizations as well as constraints on their operation. This paper discusses the critical role of water supply in achieving sustainable water security and presents two case studies from Central Asia on the management of water supply for irrigated agriculture. The analysis concludes that existing water supply bureaucracies need to be revitalized to effectively address key challenges in water security.
A review of predictive factors of student success in and satisfaction with online learning
Authors: Kauffman Heather
Published: August 2015

Students perceive online courses differently than traditional courses. Negative perceptions can lead to unfavourable learning outcomes including decreased motivation and persistence. Throughout this review, a broad range of factors that affect performance and satisfaction within the online learning environment for adult learners will be examined including learning outcomes, instructional design and learner characteristics, followed by suggestions for further research, and concluding with implications for online learning pertinent to administrators, instructors, course designers and students. Online learning may not be appropriate for every student. Identifying particular characteristics that contribute to online success versus failure may aid in predicting possible learning outcomes and save students from enrolling in online courses if this type of learning environment is not appropriate for them. Furthermore, knowing these learner attributes may assist faculty in designing quality online courses to meet students’ needs. Adequate instructional methods, support, course structure and design can facilitate student performance and satisfaction.Keywords: online learning; learner characteristics; instructional design; online learning outcomes(Published: 27 August 2015)Responsible Editor: Meg O’Reilly, Southern Cross University, AustraliaCitation: Research in Learning Technology 2015, 23: 26507 - http://dx.doi.org/10.3402/rlt.v23.26507
Surface engineering of nanoporous substrate for solid oxide fuel cells with atomic layer-deposited electrolyte
Authors: Ji Sanghoon , Tanveer Waqas Hassan , Yu Wonjong , Kang Sungmin , Cho Gu Young , Kim Sung Han , An Jihwan , Cha Suk Won
Published: August 2015

Solid oxide fuel cells with atomic layer-deposited thin film electrolytes supported on anodic aluminum oxide (AAO) are electrochemically characterized with varying thickness of bottom electrode catalyst (BEC); BECs which are 0.5 and 4 times thicker than the size of AAO pores are tested. The thicker BEC ensures far more active mass transport on the BEC side and resultantly the thicker BEC cell generates ≈11 times higher peak power density than the thinner BEC cell at 500 °C.
IMPROVING EFFICIENCY IN EMERGENCY RESPONSE FOR CONSTRUCTION SITE FIRES: AN EXPLORATORY CASE STUDY
Authors: TSAI Ming-Kuan
Published: August 2015

This study proposes an approach to assist construction managers with fire management. Since accidental fires at construction sites often go undetected until they begin to spread, they can cause serious damage. Although researchers have applied information technology to construction site safety management, few studies have focused on the relation­ship between information techniques and construction site fires. After investigating this relationship, the results revealed two problems: difficult fire detection and disorderly emergency response. Therefore, the intent of this study was to build an intelligent construction site fire management platform by integrating image recognition for automatic fire detection and knowledge models for immediate emergency response. Based on several tests on three common types of acciden­tal fires at construction sites, the results demonstrated that the platform can detect fires and alert construction manag­ers quickly. Through mobile information transmission, the construction managers were able to understand the status of on-site fires and respond appropriately. This study offers a useful reference for similar applications in construction site safety management.
Randomized Controlled Trial of the NS5A Inhibitor Daclatasvir plus Pegylated Interferon and Ribavirin for HCV Genotype-4 (COMMAND-4)
Authors: Hézode Christophe , Alric Laurent , Brown Ashley , Hassanein Tarek , Rizzetto Mario , Buti Maria , Bourlière Marc , Thabut Dominique , Molina Esther , Rustgi Vinod , Samuel Didier , McPhee Fiona , Liu Zhaohui , Yin Philip D , Hughes Eric , Treitel Michelle ,   the COMMAND-4 study team
Published: August 2015

Background

Treatment options for HCV genotype-4 (GT4) are limited. This Phase III study (COMMAND-4; AI444-042) evaluated the efficacy and safety of daclatasvir (DCV), a pan-genotypic HCV NS5A inhibitor, with pegylated interferon-α2a/ribavirin (PEG-IFN/RBV) in treatment-naive patients with HCV GT4 infection.

Methods

Patients were randomly assigned (2:1; blinded) to treatment with DCV 60 mg ( n=82) or placebo ( n=42) once daily plus PEG-IFN 180 μg weekly and RBV 1,000–1,200 mg/ day (weight-based) twice daily. DCV-treated patients with undetectable HCV RNA at weeks 4 and 12 (eRVR) received 24 weeks of DCV plus PEG-IFN/RBV; those without eRVR received an additional 24 weeks of PEG-IFN/RBV. All placebo-treated patients received 48 weeks of PEG-IFN/RBV. The primary end point was sustained virological response (SVR) at post-treatment week 12 (SVR12).

Results

Patients were 75% IL28B non-CC and 11% had cirrhosis. SVR rates (HCV RNA < lower limit of quantitation [LLOQ]) at post-treatment week 12 or later (imputed to include patients missing SVR12 assessments but had SVR after post-treatment week 12) were 82% (67/82) with DCV plus PEG-IFN/RBV versus 43% (18/42) with PEG-IFN/RBV ( P<0.0001). In DCV recipients, SVR12 rates were comparable across subgroups. The safety and tolerability profile of DCV plus PEG-IFN/RBV was comparable to that of PEG-IFN/RBV. Discontinuations due to adverse events occurred in 4.9% of patients receiving DCV plus PEG-IFN/RBV and 7.1% of patients receiving PEG-IFN/RBV.

Conclusions

In treatment-naive patients with HCV GT4 infection, DCV plus PEG-IFN/RBV achieved higher SVR12 rates than PEG-IFN/RBV alone. These data support DCV-based regimens for treatment of HCV GT4 infection, including all-oral combinations with other direct-acting antivirals (AI444-042; ClinicalTrials.gov NCT01448044).
Differential Diagnosis of Linear Eruptions in Children
Authors: Kruse Lacey L.
Published: August 2015

A 3-year-old girl presented with a linear eruption on her leg for 2 months. She was otherwise healthy and well-appearing. Physical examination showed many small, erythematous, flat-topped papules coalescing into a linear erythematous plaque. At a follow-up visit 9 months later, the eruption had resolved, leaving postinflammatory hypopigmentation.When approaching a cutaneous eruption, appreciating the pattern of the lesions can be instrumental to arriving at the correct diagnosis. For this patient with the acute onset of a plaque on the leg, the differential diagnosis is narrowed by the linear distribution of the skin lesions. The differential diagnosis of linear eruptions in children includes lichen striatus, linear lichen planus, linear psoriasis, inflammatory linear verrucous epidermal nevus, incontinentia pigmenti, phytophotodermatitis, and allergic contact dermatitis. Of note, many of these conditions manifest in a linear manner as a result of cutaneous mosaicism, whereas others are caused by external agents contacting the skin.

[
Pediatr Ann
. 2015;44(8):e194–e198.]
A Review of Annular Eruptions in Children
Authors: Todd Patricia S. , Orlowski Timothy , Schumacher-Kim Wendy
Published: August 2015

Annular, or ring-like, skin lesions are a distinctive cutaneous morphology. Dermatologic diagnosis is based on morphology and distribution, and therefore the generation of a differential diagnosis based on these criteria can lead to proper identification of an eruption. For many dermatologic conditions, considering a differential that includes infection, immune phenomenon, neoplastic process, physical etiology, and idiopathic process will assure that one thinks broadly and is likely to reveal the best diagnosis. Several of these categories are covered in this review of annular eruptions in children.

[
Pediatr Ann
. 2015;44(8):e199–e204.]
Myositis Ossificans in the Thigh of a Lacrosse Player
Authors: Goyal Kamal , Pettis Christopher R. , Bancroft Ashley E. , Wasyliw Christopher W. , Scherer Kurt F.
Published: August 2015

An 18-year-old man presented with mid left thigh pain after sequential lacrosse injuries 1 month and 2 weeks prior. Physical examination was significant for a tender mass in the mid left thigh.
One-Stage External Fixation Using a Locking Plate: Experience in 116 Tibial Fractures
Authors: Zhang Jingwei , Ebraheim Nabil A. , Li Ming , He Xianfeng , Liu Jiayong
Published: August 2015

The authors report the results of 1-stage external fixation using a locking plate in 116 tibial fractures (85 closed and 31 open). The patients were followed for an average of 22 months. The mean duration of surgery was 42 minutes. The mean fracture healing time was 12 weeks for proximal, 20 weeks for shaft, 14 weeks for distal, and 24 weeks for multisegmental tibial fractures. Nonunion, deep infection, and breakage of screws did not occur. External plate fixation is effective for tibial fractures and especially for metaphyseal fractures. It has the advantages of being easy to perform and less invasive, and the plate is conveniently located for removal. [
Orthopedics.
2015; 38(8):494–497.]
What Does Digital Media Allow Us to “Do” to One Another?
Authors: Alvermann Donna E. , Beach Crystal L. , Boggs George L.
Published: August 2015

The purpose of this integrative review of theory and research is to assess the economic impact of digital media in ways that are unreached by instrumental means of measuring economic activity. Specifically, we use three overarching arguments identified from a review of the literature that broadly defines the economic force of digital media content in contemporary society. We contextualize those arguments in terms of current issues in the field and gaps in the research base before concluding with a discussion of the implications of what we learned for education, civic engagement, social practice, and policy.
Moving beyond the Basics
Authors: Dickenson Patricia , Hall Martin T. , Courduff Jennifer
Published: August 2015

The evolution of the web has transformed the way persons communicate and interact with each other, and has reformed institutional operations in various sectors. Examining these changes through the theoretical framework Connectivism, provides a detailed analysis of how the web impacts individuals' context within communities as well as the larger society. This chapter examines the evolution of the web and the characteristics of various iterations of the web. A discussion on the emergence of participatory media and other participatory processes provides insight as to how the web influences personal and professional interactions. Research on how the web has changed cultural contexts as well as systems such as education, governments and businesses is shared and analyzed to identify gaps and provide direction for future research.
Digital Storytelling
Authors: Davis Alan , Foley Leslie
Published: August 2015

Digital storytelling, especially in the form of short personally-narrated stories first pioneered by the Center for Digital Storytelling in Berkeley in 1993, is a practice that has now expanded throughout English speaking countries and Western Europe, and has a smaller but growing presence in the developing world. This review examines the origins of the practice and early dissemination, and its current uses in community-based storytelling, education, and by cultural institutions. Research regarding the impacts and benefits of digital storytelling and relationships between storytelling, cognition and identity, and mediating technologies are examined. Current issues in the field, including issues of voice, ownership, power relationships, and dissemination are considered, along with possible future directions for research and implications for social practice and policy.
Children and Youth Making Digital Media for the Social Good
Authors: Denner Jill , Martinez Jacob
Published: August 2015

This chapter describes how children and youth are using digital media to address inequity in their schools, communities, and in society. The chapter begins with a review of the historical and cultural roots of children making digital media for the social good, and situates the approach in the context of other civic and community-based movements. The next section focuses on the range of ways that children and youth are making digital media, including who is participating, and the social and institutional factors involved. The next sections describe the benefits for the participants and for society, as well as the barriers to broader participation. Two case studies highlight key strategies for engaging marginalized youth in making digital media for the social good, and ways to expand the popularity of this approach. The chapter concludes with suggestions for future research, and the broader implications for education, civic engagement, social practice and policy.
New and Strange Sorts of Texts
Authors: Hundley Melanie Kittrell , Holbrook Teri
Published: August 2015

Dennis Baron (1999) writes about the impact of digital technology on literacy practices and thus is a good exemplar for considering how communication technologies are changing the ways in which stories are told. In this chapter, we argue that young adult literature authors and readers are currently in what Baron terms an inventive stage as they devise new ways of producing storied texts. Young adult authors, aware of their readers as avid, exploring, and savvy tech users, experiment with text formats to appeal to readers growing up in a digital “participatory culture” (Jenkins, Purushotma, Weigel, Clinton & Robins, 2009). In a cultural climate where the very notion of what constitutes a book is changing, our chapter responds to Baron's (2009) claim that readers and writers are in the process of “[learning] to trust a new technology and the new and strange sorts of texts that it produces” (p. x).
Instant Messaging and Texting
Authors: Jacobs Gloria E.
Published: August 2015

This chapter contains an examination of the research into texting and instant messaging. Instant messaging and texting are shown to be powerful technologies for maintaining relationships, building identities, and functioning within an information based society. The author raises questions about the implications of these social practices for those individuals who remain on the digital margins. The chapter provides an overview of the research, including a brief history of the technology and a theoretical framing of the terms used to discuss the phenomenon. A discussion of who uses instant messaging and why, and what the research has found regarding the conventions of use associated with instant messaging and texting follows. The chapter ends with a discussion of the current issues in the field, locates gaps in the research, and identifies implications and recommendations for education, civic engagement, social practice, and policy.
Cyberbullying and Internet Safety
Authors: Kelly Deirdre M. , Arnold Chrissie
Published: August 2015

The chapter considers cyberbullying in relation to Internet safety, concentrating on recent, high quality empirical studies. The review discusses conventional debates over how to define cyberbullying, arguing to limit the term to repeated, electronically-mediated incidents involving intention to harm and a power imbalance between bully and victim. It also takes note of the critical perspective that cyberbullying—through its generic and individualistic framing—deflects attention from the racism, sexism, ableism, and heterosexism that can motivate or exacerbate the problem of such bullying. The review concludes that: (a) cyberbullying, rigorously defined, is a phenomenon that is less pervasive and dire than widely believed; and (b) cyber-aggression and online harassment are more prevalent, yet understudied. Fueled by various societal inequalities, these latter forms of online abuse require urgent public attention. The chapter's recommendations are informed by a view of young people as apprentice citizens, who learn democratic participation by practicing it.