bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective Inhibition of Human Monoamine Oxidase B by Acacetin 7-Methyl Ether Isolated from Turnera diffusa (Damiana)
Authors: Chaurasiya Narayan D. , Zhao Jianping , Pandey Pankaj , Doerksen Robert J. , Muhammad Ilias , Tekwani Babu L.
Published: February 2019

The investigation of the constituents that were isolated from Turnera diffusa (damiana) for their inhibitory activities against recombinant human monoamine oxidases (MAO-A and MAO-B) in vitro identified acacetin 7-methyl ether as a potent selective inhibitor of MAO-B (IC50 = 198 nM). Acacetin 7-methyl ether (also known as 5-hydroxy-4′, 7-dimethoxyflavone) is a naturally occurring flavone that is present in many plants and vegetables. Acacetin 7-methyl ether was four-fold less potent as an inhibitor of MAO-B when compared to acacetin (IC50 = 50 nM). However, acacetin 7-methyl ether was >500-fold selective against MAO-B over MAO-A as compared to only two-fold selectivity shown by acacetin. Even though the IC50 for inhibition of MAO-B by acacetin 7-methyl ether was ~four-fold higher than that of the standard drug deprenyl (i.e., SelegilineTM or ZelaparTM, a selective MAO-B inhibitor), acacetin 7-methyl ether’s selectivity for MAO-B over MAO-A inhibition was greater than that of deprenyl (>500- vs. 450-fold). The binding of acacetin 7-methyl ether to MAO-B was reversible and time-independent, as revealed by enzyme-inhibitor complex equilibrium dialysis assays. The investigation on the enzyme inhibition-kinetics analysis with varying concentrations of acacetin 7-methyl ether and the substrate (kynuramine) suggested a competitive mechanism of inhibition of MAO-B by acacetin 7-methyl ether with Ki value of 45 nM. The docking scores and binding-free energies of acacetin 7-methyl ether to the X-ray crystal structures of MAO-A and MAO-B confirmed the selectivity of binding of this molecule to MAO-B over MAO-A. In addition, molecular dynamics results also revealed that acacetin 7-methyl ether formed a stable and strong complex with MAO-B. The selective inhibition of MAO-B suggests further investigations on acacetin 7-methyl as a potential new drug lead for the treatment of neurodegenerative disorders, including Parkinson’s disease.
Identification of Novel Benzoxa-[2,1,3]-diazole Substituted Amino Acid Hydrazides as Potential Anti-Tubercular Agents
Authors: Brown Alistair K. , Aljohani Ahmed K. B. , Gill Jason H. , Steel Patrick G. , Sellars Jonathan D.
Published: February 2019

Discovery and development of new therapeutic options for the treatment of Mycobacterium tuberculosis (Mtb) infection are desperately needed to tackle the continuing global burden of this disease and the efficacy and cost limitations associated with current medicines. Herein, we report the synthesis of a series of novel benzoxa-[2,1,3]-diazole substituted amino acid hydrazides in a two-step synthesis and evaluate their inhibitory activity against Mtb and selected bacterial strains of clinical importance utilising an end point-determined REMA assay. Alongside this, their potential for undesired cytotoxicity against mammalian cells was assessed employing standard MTT assay methodologies. It has been demonstrated using modification at three sites (the hydrazine, amino acid, and the benzodiazole) it is possible to change both the antibacterial activity and cytotoxicity of these molecules whilst not affecting their microbial selectivity, making them attractive architectures for further exploitation as novel antibacterial agents.
The Proanthocyanidin-Rich Fraction Obtained from Red Rice Germ and Bran Extract Induces HepG2 Hepatocellular Carcinoma Cell Apoptosis
Authors: Upanan Supranee , Yodkeeree Supachai , Thippraphan Pilaiporn , Punfa Wanisa , Wongpoomchai Rawiwan , Limtrakul (Dejkriengkraikul) Pornngarm
Published: February 2019

This study aims to determine the anti-carcinogenic effects of the proanthocyanidin-rich fraction (PRFR) obtained from red rice germ and bran extract on HepG2 cells. The PRFR obtained from red rice germ and bran extract could reduce the cell viability of HepG2 cells as shown by the IC50 value at 20 µg/mL. Notably, PRFR concentrations at 20 and 40 µg/mL significantly increased the number of cells in the G2/M phase from 25.7% ± 1.4%in the control group to 36.2% ± 3.4% (p < 0.01) and 48.9% ± 2.6% (p < 0.0001), respectively, suggesting that the cells were arrested in this phase, which was confirmed by the reduction of survival proteins, including cyclin B1 and cdc25. Moreover, the PRFR at 20 and 40 µg/mL could induce cell death via the apoptosis cascade, indicated by the percentage of total apoptotic cells from 9.9% ± 3.1% in the control group to 41.1 ± 3.9 (p < 0.0001) and 82.2% ± 5.8% (p < 0.0001), respectively. This was clarified by increasing apoptotic proteins (such as cleaved PARP-1, cleaved caspase-8 and cleaved caspase-3) and decreasing anti-apoptotic protein survivin without p53 alterations. These results demonstrated that the PRFR obtained from red rice germ and bran extract could inhibit cell proliferation and induce cell apoptosis in HepG2 cells via survivin, which could potentially serve as a new target for cancer therapeutics making it an excellent “lead candidate” molecule for in vivo proof-of concept studies.
Engineering of Antimicrobial Surfaces by Using Temporin Analogs to Tune the Biocidal/antiadhesive Effect
Authors: Oger Pierre-Carl , Piesse Christophe , Ladram Ali , Humblot Vincent
Published: February 2019

Proliferation of resistant bacteria on biomaterials is a major problem leading to nosocomial infections. Due to their broad-spectrum activity and their ability to disrupt bacterial membranes through a rapid membranolytic mechanism, antimicrobial peptides (AMPs) are less susceptible to the development of bacterial resistance and therefore represent good candidates for surface coating strategies to prevent biofilm formation. In this study, we report on the covalent immobilization of temporin-SHa, a small hydrophobic and low cationic antimicrobial peptide exhibiting broad-spectrum activity, and (SHa) analogs on modified gold surfaces. Several analogs derived from SHa with either a carboxamidated ([K3]SHa, d-[K3]SHa) or a carboxylated C-terminus ([K3]SHa-COOH) were used to achieve peptide grafting on gold surfaces modified by a thiolated self-assembled monolayer (SAM). Surface functionalization was characterized by polarization modulation infrared reflection absorption spectroscopy (PM-RAIRS) and X-ray photoemission spectroscopy (XPS). The antibacterial properties of the temporin-functionalized surfaces were tested against the Gram-positive Listeria ivanovii. Direct visualization of the peptide effects on the bacterial membrane was investigated by scanning electron microscopy equipped with a field emission gun (SEM-FEG). All active temporin analogs were successfully grafted and display significant antibacterial activity (from 80 to 90% killing efficiency) in addition to a 2-fold decrease of bacterial adhesion when all d-SHa analogs were used.
Microwave-Assisted Extraction of Multiple Trace Levels of Intermediate Metabolites for Camptothecin Biosynthesis in Camptotheca acuminata and Their Simultaneous Determination by HPLC-LTQ-Orbitrap-MS/MS and HPLC-TSQ-MS
Authors: Jin Zhaoxia , Wan Ruyi , Yan Ruxue , Su Yingying , Huang Honglan , Zi Lihan , Yu Fang
Published: February 2019

Camptothecin (CPT) has strong antitumor activity and is used as an anticancer therapeutic agent. To better understand and decipher the pathway of CPT biosynthesis in Camptotheca acuminata, the main purpose here was focused on creating an effective extraction strategy for a rich intermediate metabolite profile. In the present study, a 70% aqueous acetonitrile was verified as an optimal extraction solvent for microwave-assisted extraction (MAE) of metabolites by spiking experiments. Based on multi-objective optimization, the best extraction conditions of a solid-liquid ratio of 1:20, microwave power of 230 W, and a time of 4 min were achieved using a full factorial 34 experimental design. Crude extracts obtained from the shoot apex of C. acuminata using MAE have been qualitatively profiled by high-performance liquid chromatography coupled with linear ion trap quadrupole-orbitrap mass spectrometry (HPLC-LTQ-Orbitrap-MS/MS) and a HPLC triple quadrupole-MS (HPLC-TSQ-MS) analysis was conducted for their metabolite content in different tissues. CPT, and ten related metabolites and their isomers, including tryptamine, loganic acid, secologanic acid, strictosidinic acid, strictosamide, strictosamide epoxide, strictosamide diol, strictosamide ketolactam, pumiloside, and deoxypumiloside, were detected and tentatively identified. Scanning electron microscopy (SEM) imaging of the shoot apex demonstrated that severe cell disruption was evident after intensified extraction processes. The study showed the difference of metabolite profiles and the enhancement of metabolite content after microwave-pretreated techniques, and the established MAE procedure is an effective methodology to preserve valuable metabolite compounds for analysis.
Antimicrobial Activities of Tea Polyphenol on Phytopathogens: A Review
Authors: Yang Yuheng , Zhang Tong
Published: February 2019

The use of natural antimicrobial compounds in crop production has gained much attention from consumers and the agricultural industry. Consequently, interest in more natural, non-synthetic antimicrobials as potential alternatives to conventional chemical pesticides to combat phytopathogens has heightened. Tea polyphenol (TP), a unique and highly important functional component of tea plants, has been reported to possess antimicrobial properties against a wide spectrum of plant pathogens. The aim of this review is to discuss the emerging findings on the mechanisms of antimicrobial action, and the antimicrobial properties of TP, including their major components, effectiveness, and synergistic effects. More studies, particularly field studies, are still necessary to establish conclusive evidence for the effectiveness of TP against phytopathogens. However, the basic conclusion from existing studies suggests that TP is a potential antimicrobial agent for pesticide reduction in agricultural systems.
Analysis of 27 β-Blockers and Metabolites in Milk Powder by High Performance Liquid Chromatography Coupled to Quadrupole Orbitrap High-Resolution Mass Spectrometry
Authors: Cheng Jian-Qiao , Liu Tong , Nie Xue-Mei , Chen Feng-Ming , Wang Chuan-Sheng , Zhang Feng
Published: February 2019

This paper presents an application of high performance liquid chromatography coupled with quadrupole orbitrap high-resolution mass spectrometry (HPLC-Q-Orbitrap HRMS) for the analysis of 27 β-blockers and metabolites in milk powder. Homogenized milk power samples were extracted by acetonitrile and purified by using Oasis PRiME HLB solid-phase extraction cartridges. The Ascentis® C8 chromatographic column was used to separate the analytes. The quantification was achieved by using matrix-matched standard calibration curves with carazolol-d7 and propranolol-d7 as the internal standards. The results show an exceptional linear relationship with the concentrations of analytes over wide concentration ranges (0.5–500 μg kg−1) as all the fitting coefficients of determination r2 are > 0.995. All the limits of detection (LODs) and quantitation (LOQs) values were within the respective range of 0.2–1.5 μg kg−1 and 0.5–5.0 μg kg−1. Overall average recoveries were able to reach 66.1–100.4% with the intra- and inter-day variability under 10%. This method has been successfully applied to the screening of β-blockers and metabolites in commercial milk powders. At the same time, the corresponding characteristic fragmentation behavior of the 27 compounds was explored. The characteristic product ions were determined and applied to the actual samples screening.
Single Molecule Fluorescence Spectroscopy of PSI Trimers from Arthrospira platensis: A Computational Approach
Authors: Pishchalnikov Roman , Shubin Vladimir , Razjivin Andrei
Published: February 2019

Based on single molecule spectroscopy analysis and our preliminary theoretical studies, the linear and fluorescence spectra of the PSI trimer from Arthrospira platensis with different realizations of the static disorder were modeled at cryogenic temperature. Considering the previously calculated spectral density of chlorophyll, an exciton model for the PSI monomer and trimer including the red antenna states was developed taking into account the supposed similarity of PSI antenna structures from Thermosynechococcus e., Synechocystis sp. PCC6803, and Arthrospira platensis. The red Chls in the PSI monomer were assumed to be in the nearest proximity of the reaction center. The PSI trimer model allowed the simulation of experimentally measured zero phonon line distribution of the red states considering a weak electron-phonon coupling for the antenna exciton states. However, the broad absorption and fluorescence spectra of an individual emitter at 760 nm were calculated by adjusting the Huang-Rhys factors of the chlorophyll lower phonon modes assuming strong electron-phonon coupling.
Synthesis of Phthalides and α,β-butenolides by Transition Metal-Catalyzed Activation of C—H Bonds
Authors: Renzetti Andrea , Fukumoto Kozo
Published: February 2019

Phthalides and α,β-butenolides are two related classes of oxygenated heterocycles with a wide range of biological activities. An innovative strategy to prepare these compounds is based on C—H bond functionalization reactions, in which two simple, unfunctionalized molecules are coupled together with cleavage of a C—H bond and formation of a C—X bond (X=C or heteroatom). This paper reviews the methods for the synthesis of phthalides and α,β-butenolides by C—H bond functionalization from non-halogenated starting materials. Over 30 methods are reported, mostly developed during the past ten years.
In Vitro Infant Faecal Fermentation of Low Viscosity Barley β-Glucan and Its Acid Hydrolyzed Derivatives: Evaluation of Their Potential as Novel Prebiotics
Authors: Lam Ka-Lung , Ko Kin-Chun , Li Xiaojie , Ke Xinxin , Cheng Wai-Yin , Chen Tianfeng , You Lijun , Kwan Hoi-Shan , Cheung Peter Chi-Keung
Published: February 2019

Barley contains high level of β-1,3-1,4-glucans (BBGs) which can be fermented by microbes and are a potential prebiotic. In the present study, native BBG with low viscosity and a MW of 319 kDa was depolymerized by acid hydrolysis to produce a series of four structurally characterized fragments with MWs ranging from 6–104 kDa. In vitro fermentation of these BBG samples by infant faecal microbiome was evaluated using a validated deep-well plate protocol as parallel miniature bioreactors. Microbial taxa were identified using 16S amplicon sequencing after 40 h of anaerobic fermentation. Bioinformatics analysis including diversity indexes, predicted metagenomic KEGG functions and predicted phenotypes were performed on the sequenced data. Short chain fatty acids and dissolved ammonia were quantified and the SCFAs/NH3 ratio was used to evaluate the eubiosis/dysbiosis potential. Correlation analysis showed that most of the parameters investigated showed a parabolic function instead of a monotonous function with the BBG samples having different MWs. Among the five BBGs, it was concluded that BBG with an intermediate MW of 28 kDa is the most promising candidate to be developed as a novel prebiotic.
Menaquinone 7 Stability of Formulations and Its Relationship with Purity Profile
Authors: Orlando Patrick , Silvestri Sonia , Marcheggiani Fabio , Cirilli Ilenia , Tiano Luca
Published: February 2019

Menaquinone-7 (MK7) is a member of the vitamin K family in which interest has considerably increased over the last decade, mainly due to its beneficial role in human health. MK7 can be produced by synthesis or fermentation, and its purity profile can differ depending on methodologies and extraction procedures. Finished formulations show a high heterogeneity of purity profiles, as well as frequent discrepancies in the nominal content, compared to the actual title. The present study compared purity profiles of different raw material and related them to their stability in normal (12 months/25 °C/60%RH) and accelerated conditions (6 months/40 °C/75% RH) in order to test their performance in the presence of different common excipients. Results showed higher purity profile results in enhanced stability, and this could explain title discrepancies found in finished products, which are present on the market worldwide.
A Non-Enzymatic and Label-Free Fluorescence Bioassay for Ultrasensitive Detection of PSA
Authors: Sun Yujie , Wang Chenyun , Zhang Hong , Zhang Yulin , Zhang Guojun
Published: February 2019

The early diagnosis of prostate cancer is very vital for the improvement of patient survival chances. The content of prostate specific antigen (PSA) in serum is closely related to the status of the prostate cancer. We report a fluorescence bioassay, capable of detecting PSA in a non-enzymatic and label-free manner. PSA gives rise to the structural change of a hairpin, consequently triggering the hybridization chain reaction and forming a long-nicked double-helix, which is not adsorbed by graphene oxide. GelRed, as the signal indicator, then binds with dsDNA molecule, thereby producing the fluorescence. The established bioassay has the merits of simple operation, favorable cost-to-benefit ratios, good stability, and specificity. Moreover, the detection limit of this assay is as low as 10 pg/mL, and the linearity range is wide—from 100 pg/mL to 200 ng/mL. At the same time, this bioassay can realize the detection of PSA in biological samples (human serum, saliva, and urine). Therefore, the bioassay provides a potential means for the early diagnosis of prostate cancer.
Colistin Sulfate Chiral Stationary Phase for the Enantioselective Separation of Pharmaceuticals Using Organic Polymer Monolithic Capillary Chromatography
Authors: Fouad Ali , Shaykoon Montaser Sh. A. , Ibrahim Samy M. , El-Adl Sobhy M. , Ghanem Ashraf
Published: February 2019

A new functionalized polymer monolithic capillary with a macrocyclic antibiotic, namely colistin sulfate, as chiral selector was prepared via the copolymerization of binary monomer mixtures consisting of glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA) in porogenic solvents namely 1-propanol and 1,4-butanediol, in the presence of azobisiso-butyronitrile (AIBN) as initiator and colistin sulfate. The prepared capillaries were investigated for the enantioselective nano-LC separation of a group of racemic pharmaceuticals, namely, α- and β-blockers, anti-inflammatory drugs, antifungal drugs, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, antihistaminics, anticancer drugs, and antiarrhythmic drugs. Acceptable separation was achieved for many drugs using reversed phase chromatographic conditions with no separation achieved under normal phase conditions. Colistin sulfate appears to be useful addition to the available macrocyclic antibiotic chiral phases used in liquid chromatography.
Bioassay-Guided Isolation and Structure Elucidation of Fungicidal and Herbicidal Compounds from Ambrosia salsola (Asteraceae)
Authors: Perera Wilmer H. , Meepagala Kumudini M. , Fronczek Frank R. , Cook Daniel D. , Wedge David E. , Duke Stephen O.
Published: February 2019

The discovery of potent natural and ecofriendly pesticides is one of the focuses of the agrochemical industry, and plant species are a source of many potentially active compounds. We describe the bioassay-guided isolation of antifungal and phytotoxic compounds from the ethyl acetate extract of Ambrosia salsola twigs and leaves. With this methodology, we isolated and identified twelve compounds (four chalcones, six flavonols and two pseudoguaianolide sesquiterpene lactones). Three new chalcones were elucidated as (S)-β-Hydroxy-2′,3,4,6′-tetrahydroxy-5-methoxydihydrochalcone (salsolol A), (S)-β-Hydroxy-2′,4,4′,6′-tetrahydroxy-3-methoxydihydrochalcone (salsolol B), and (R)-α, (R)-β-Dihydroxy-2′,3,4,4′,6′-pentahydroxydihydrochalcone (salsolol C) together with nine known compounds: balanochalcone, six quercetin derivatives, confertin, and neoambrosin. Chemical structures were determined based on comprehensive direct analysis in real time-high resolution mass spectrometry (HR-DART-MS), as well as 1D and 2D NMR experiments: Cosy Double Quantum Filter (DQFCOSY), Heteronuclear Multiple Quantum Coherence (HMQC) and Heteronuclear Multiple Bond Coherence (HMBC), and the absolute configurations of the chalcones were confirmed by CD spectra analysis. Crystal structure of confertin was determined by X-ray diffraction. The phytotoxicity of purified compounds was evaluated, and neoambrosim was active against Agrostis stolonifera at 1 mM, while confertin was active against both, Lactuca sativa and A. stolonifera at 1 mM and 100 µM, respectively. Confertin and salsolol A and B had IC50 values of 261, 275, and 251 µM, respectively, against Lemna pausicotata (duckweed). The antifungal activity was also tested against Colletotrichum fragariae Brooks using a thin layer chromatography bioautography assay. Both confertin and neoambrosin were antifungal at 100 µM, with a higher confertin activity than that of neoambrosin at this concentration.
MicroRNA in Brain pathology: Neurodegeneration the Other Side of the Brain Cancer
Authors: Godlewski Jakub , Lenart Jacek , Salinska Elzbieta
Published: February 2019

The mammalian brain is made up of billions of neurons and supporting cells (glial cells), intricately connected. Molecular perturbations often lead to neurodegeneration by progressive loss of structure and malfunction of neurons, including their death. On the other side, a combination of genetic and cellular factors in glial cells, and less frequently in neurons, drive oncogenic transformation. In both situations, microenvironmental niches influence the progression of diseases and therapeutic responses. Dynamic changes that occur in cellular transcriptomes during the progression of developmental lineages and pathogenesis are controlled through a variety of regulatory networks. These include epigenetic modifications, signaling pathways, and transcriptional and post-transcriptional mechanisms. One prominent component of the latter is small non-coding RNAs, including microRNAs, that control the vast majority of these networks including genes regulating neural stemness, differentiation, apoptosis, projection fates, migration and many others. These cellular processes are also profoundly dependent on the microenvironment, stemness niche, hypoxic microenvironment, and interactions with associated cells including endothelial and immune cells. Significantly, the brain of all other mammalian organs expresses the highest number of microRNAs, with an additional gain in expression in the early stage of neurodegeneration and loss in expression in oncogenesis. However, a mechanistic explanation of the concept of an apparent inverse correlation between the odds of cancer and neurodegenerative diseases is only weakly developed. In this review, we thus will discuss widespread de-regulation of microRNAome observed in these two major groups of brain pathologies. The deciphering of these intricacies is of importance, as therapeutic restoration of pre-pathological microRNA landscape in neurodegeneration must not lead to oncogenesis and vice versa. We thus focus on microRNAs engaged in cellular processes that are inversely regulated in these diseases. We also aim to define the difference in microRNA networks between pro-survival and pro-apoptotic signaling in the brain.
Carbon Mineralization by Reaction with Steel-Making Waste: A Review
Authors: Ibrahim Mohamed H. , El-Naas Muftah H. , Benamor Abdelbaki , Al-Sobhi Saad S. , Zhang Zhien
Published: February 2019

Carbon capture and sequestration (CCS) is taking the lead as a means for mitigating climate change. It is considered a crucial bridging technology, enabling carbon dioxide (CO2) emissions from fossil fuels to be reduced while the energy transition to renewable sources is taking place. CCS includes a portfolio of technologies that can possibly capture vast amounts of CO2 per year. Mineral carbonation is evolving as a possible candidate to sequester CO2 from medium-sized emissions point sources. It is the only recognized form of permanent CO2 storage with no concerns regarding CO2 leakage. It is based on the principles of natural rock weathering, where the CO2 dissolved in rainwater reacts with alkaline rocks to form carbonate minerals. The active alkaline elements (Ca/Mg) are the fundamental reactants for mineral carbonation reaction. Although the reaction is thermodynamically favored, it takes place over a large time scale. The challenge of mineral carbonation is to offset this limitation by accelerating the carbonation reaction with minimal energy and feedstock consumption. Calcium and magnesium silicates are generally selected for carbonation due to their abundance in nature. Industrial waste residues emerge as an alternative source of carbonation minerals that have higher reactivity than natural minerals; they are also inexpensive and readily available in proximity to CO2 emitters. In addition, the environmental stability of the industrial waste is often enhanced as they undergo carbonation. Recently, direct mineral carbonation has been investigated significantly due to its applicability to CO2 capture and storage. This review outlines the main research work carried out over the last few years on direct mineral carbonation process utilizing steel-making waste, with emphasis on recent research achievements and potentials for future research.
Development of 3D Finite Element Method for Non-Aqueous Phase Liquid Transport in Groundwater as Well as Verification
Authors: Yu Wei , Li Hong
Published: February 2019

Groundwater contamination previously occurred at a broad range of locations in present-day China. There are thousands of kinds of contaminants which can be divided into soluble and insoluble categories in groundwater. In recent years, the non-aqueous phase liquid (NAPL) pollution that belongs to the multi-phase seepage flow phenomenon has become an increasingly prominent topic due to the challenge brought by groundwater purification and its treatment. Migrating with seepage flow and moving into the potable water sources, these contaminants directly endanger people’s health. Therefore, it is necessary to research how these contaminants not only migrate, but also are then accordingly remedied. First, as an analysis means, an effective numerical method is necessary to be built. A three-dimensional finite element method program for analyzing two-phase flow in porous media, which can be applied to the immiscible contaminant transport problem in subsurface flow has been developed in this paper. The fundamental theory and numerical discretization formulations are elaborated. The numerical difficulty brought about by the distinct non-linearity of the temporal evolution of saturation-dependent variables is overcome by the mixed-form formulation. The effectiveness of simultaneous solution (SS) method and its improvement in efficiency are explained. Finally, two computational examples are given for verifying the correctness and demonstrating the preliminary applicability. In addition, the function of two-phase immiscible flow, especially in Fast Lagrangian Analysis of Continua (FLAC) is used to simulate the same examples and the results are compared to further verify the correctness of the numerical development.
An Integrated Delphi-AHP and Fuzzy TOPSIS Approach toward Ranking and Selection of Renewable Energy Resources in Pakistan
Authors: Solangi Yasir Ahmed , Tan Qingmei , Mirjat Nayyar Hussain , Valasai Gordhan Das , Khan Muhammad Waris Ali , Ikram Muhammad
Published: February 2019

Pakistan has long relied on fossil fuels for electricity generation. This is despite the fact that the country is blessed with enormous renewable energy (RE) resources, which can significantly diversify the fuel mix for electricity generation. In this study, various renewable resources of Pakistan—solar, hydro, biomass, wind, and geothermal energy—are analyzed by using an integrated Delphi-analytical hierarchy process (AHP) and fuzzy technique for order of preference by similarity to ideal solution (F-TOPSIS)-based methodology. In the first phase, the Delphi method was employed to define and select the most important criteria for the selection of RE resources. This process identified four main criteria, i.e., economic, environmental, technical, and socio-political aspects, which are further supplemented by 20 sub-criteria. AHP is later used to obtain the weights of each criterion and the sub-criteria of the decision model. The results of this study reveal wind energy as the most feasible RE resource for electricity generation followed by hydropower, solar, biomass, and geothermal energy. The sensitivity analysis of the decision model results shows that the results of this study are significant, reliable, and robust. The study provides important insights related to the prioritizing of RE resources for electricity generation and can be used to undertake policy decisions toward sustainable energy planning in Pakistan.
Beyond Atheism and Atheology: The Divine Humanism of Emmanuel Levinas
Authors: Cruz Manuel A.
Published: February 2019

Is the divine a meaningful and indispensable element of moral responsibility? Emmanuel Levinas’ ethics have brought new expression to the question of God and the Good. Contemporary engagements with Levinas’ provocation, however, have generated a morass of contrary judgments and enigmatic explications, including praise and criticism for its atheology, secular transcendence, and crypto-religious conceit. The essay takes issue with secular and atheistic interpretations of Levinas, arguing that his mature ethics offer a philosophical species of divine humanism, one that justifies the indispensable significance of the divine for moral responsibility. It examines the philosophical problems that lead to the creation of new phenomenological descriptions for divine transcendence, and it sheds light on the seemingly erratic scattering of divine names—infinite, third person, trace, immemorial past, absence, beyond being, illeity—as improvisational orchestrations for God at the margins of moral responsibility.
Potential of Renewable Energy Resources with an Emphasis on Solar Power in Iraq: An Outlook
Authors: Al-Kayiem Hussain H. , Mohammad Sanan T.
Published: February 2019

This study presents an outlook on the renewable energies in Iraq, and the potential for deploying concentrated solar power technologies to support power generation in Iraq. Solar energy has not been sufficiently utilized at present in Iraq. However, this energy source can play an important role in energy production in Iraq, as the global solar radiation ranging from 2000 kWh/m2 to a 2500 kWh/m2 annual daily average. In addition, the study presents the limited current solar energy activities in Iraq. The attempts of the Iraqi government to utilize solar energy are also presented. Two approaches for utilizing concentrated solar power have been proposed, to support existing thermal power generation, with the possibility of being implemented as standalone plants or being integrated with thermal power plants. However, the cost analysis has shown that for 50 kW concentrated solar power in Iraq, the cost is around 0.23 US cent/kWh without integration with energy storage. Additionally, notable obstacles and barriers bounding the utilization of solar energy are also discussed. Finally, this study proposes initiatives that can be adopted by the Iraqi government to support the use of renewable energy resources in general, and solar energy in particular.
Determining Distribution for the Product of Random Variables by Using Copulas
Authors: Ly Sel , Pho Kim-Hung , Ly Sal , Wong Wing-Keung
Published: February 2019

Determining distributions of the functions of random variables is one of the most important problems in statistics and applied mathematics because distributions of functions have wide range of applications in numerous areas in economics, finance, risk management, science, and others. However, most studies only focus on the distribution of independent variables or focus on some common distributions such as multivariate normal joint distributions for the functions of dependent random variables. To bridge the gap in the literature, in this paper, we first derive the general formulas to determine both density and distribution of the product for two or more random variables via copulas to capture the dependence structures among the variables. We then propose an approach combining Monte Carlo algorithm, graphical approach, and numerical analysis to efficiently estimate both density and distribution. We illustrate our approach by examining the shapes and behaviors of both density and distribution of the product for two log-normal random variables on several different copulas, including Gaussian, Student-t, Clayton, Gumbel, Frank, and Joe Copulas, and estimate some common measures including Kendall’s coefficient, mean, median, standard deviation, skewness, and kurtosis for the distributions. We found that different types of copulas affect the behavior of distributions differently. In addition, we also discuss the behaviors via all copulas above with the same Kendall’s coefficient. Our results are the foundation of any further study that relies on the density and cumulative probability functions of product for two or more random variables. Thus, the theory developed in this paper is useful for academics, practitioners, and policy makers.
Low-Energy Data Collection in Wireless Sensor Networks Based on Matrix Completion
Authors: Xu Yi , Sun Guiling , Geng Tianyu , He Jingfei
Published: February 2019

Sparse sensing schemes based on matrix completion for data collection have been proposed to reduce the power consumption of data-sensing and transmission in wireless sensor networks (WSNs). While extensive efforts have been made to improve the recovery accuracy from the sparse samples, it is usually at the cost of running time. Moreover, most data-collection methods are difficult to implement with low sampling ratio because of the communication limit. In this paper, we design a novel data-collection method including a Rotating Random Sparse Sampling method and a Fast Singular Value Thresholding algorithm. With the proposed method, nodes are in the sleep mode most of the time, and the sampling ratio varies over time slots during the sampling process. From the samples, a corresponding algorithm with Nesterov technique is given to recover the original data accurately and fast. With two real-world data sets in WSNs, simulations verify that our scheme outperforms other schemes in terms of energy consumption, reconstruction accuracy, and rate. Moreover, the proposed sampling method enhances the recovery algorithm and prolongs the lifetime of WSNs.
Application of a Novel Long-Gauge Fiber Bragg Grating Sensor for Corrosion Detection via a Two-level Strategy
Authors: Cheng Yuyao , Zhao Chenyang , Zhang Jian , Wu Zhishen
Published: February 2019

Corrosion of main steel reinforcement is one of the most significant causes of structuraldeterioration and durability reduction. This research proposes a two-level detection strategy tolocate and quantify corrosion damage via a new kind of long-gauge fiber Bragg grating (FBG) sensor.Compared with the traditional point strain gauges, this new sensor has been developed for bothlocal and global structural monitoring by measuring the averaged strain within a long gauge length.Based on the dynamic macrostrain responses of FBG sensors, the strain flexibility of structures areidentified for corrosion locating (Level 1), and then the corrosion is quantified (Level 2) in terms ofreduction of sectional stiffness of reinforcement through the sensitivity analysis of strain flexibility.The two-level strategy has the merit of reducing the number of unknown structural parametersthrough corrosion damage location (Level 1), which guarantees that the corrosion quantification(Level 2) can be performed efficiently in a reduced domain. Both numerical and experimentalexamples have been studied to reveal the ability of distributed long-gauge FBG sensors for corrosionlocalization and quantification.
Indoor Visible Light Positioning: Overcoming the Practical Limitations of the Quadrant Angular Diversity Aperture Receiver (QADA) by Using the Two-Stage QADA-Plus Receiver
Authors: Cincotta Stefanie , He Cuiwei , Neild Adrian , Armstrong Jean
Published: February 2019

Visible light positioning (VLP), using LED luminaires as beacons, is a promising solution to the growing demand for accurate indoor positioning. In this paper, we introduce a two-stage receiver that has been specifically designed for VLP. This receiver exploits the advantages of two different VLP receiver types: photodiodes and imaging sensors. In this new receiver design a quadrant angular diversity aperture (QADA) receiver is combined with an off-the-shelf camera to form a robust new receiver called QADA-plus. Results are presented for QADA that show the impact of noise and luminaire geometry on angle of arrival estimation accuracy and positioning accuracy. Detailed discussions highlight other potential sources of error for the QADA receiver and explain how the two-stage QADA-plus can overcome these issues.
Agroecological Strategies for Reactivating the Agrarian Sector: The Case of Agrolab in Madrid
Authors: García-Llorente Marina , Pérez-Ramírez Irene , Sabán de la Portilla Clara , Haro Carmen , Benito Alejandro
Published: February 2019

Considering the social and ecological obsolescence of the conventional agricultural model and the crisis faced by rural areas, innovative models based on collective initiatives and agroecological practices are emerging. Here, we present the use of a participatory farming lab as a space to reactivate the agrarian sector in rural and periurban areas of Madrid. The specific objectives of this study are: (1) to describe the project; (2) to identify participants’ profiles and motivations and (3) to identify the most socially valued ecosystem services and the actions collectively taken to enhance them. To do so, we have used the living lab conceptual approach and the ecosystem service lens. Data gathering included a combination of qualitative and quantitative techniques, including participant observation, informal and formal meetings, interviews, workshops and surveys. We found a diversity of motivations for enrolling in the program and 20 ecosystem services were selected as socially important. We also describe how the project has contributed to adopting agroecological practices to sustain those ecosystem services. Finally, we discuss the contribution of the project towards new and integrated rural development strategies, including its potential to promote cooperative solutions that enhance farming activity by also providing ecosystem services.
Structure Dynamics and Risk Assessment of Water-Energy-Food Nexus: A Water Footprint Approach
Authors: Zhang Peng , Xu Zihan , Fan Weiguo , Ren Jiahui , Liu Ranran , Dong Xiaobin
Published: February 2019

The “Water-Energy-Food Nexus” is one of the present research hotspots in the field of sustainable development. Water resources are the key factors that limit local human survival and socioeconomic development in arid areas, and the water footprint is an important indicator for measuring sustainable development. In this study, the structural dynamics and complex relationships of the water-energy-food system in arid areas were analyzed from the perspective of the water footprint, and the risk characteristics were evaluated. The results show that: (1) Agriculture products and livestock products account for the largest water footprints (>90%), which is much higher than the water footprints of energy consumption (<5%). From the water footprint type, the blue water footprint (>50%) > the grey water footprint (20%–30%) > the green water footprint (<20%). (2) Since 2000, especially after 2005, while energy consumption drove rapid economic growth, it also led to the rapid expansion of the water footprint in the Manas River Basin. By 2015, the water deficit was relatively serious, with the surface water resource deficit reaching 16.21 × 108 m3. (3) The water-energy risk coupling degree of the water-energy-food system in this basin is comparatively significant, which means that it is facing the dual pressures of internal water shortage and external energy dependence, and it is vulnerable to global warming and fluctuations in the international and domestic energy markets. Thus, it is necessary to adjust the industrial structure through macroeconomic regulation and control, developing new energy sources, reducing the coupling degree of system risks, and achieving sustainable development.
How Does A Firm’s Previous Social Network Position Affect Innovation? Evidence from Chinese Listed Companies
Authors: Wei Xuan , Chen Wei
Published: February 2019

The impact of social network position on innovation has been widely confirmed in past studies. However, research on the time-lag structure of the impact is still insufficient. Within the time window 2010 to 2017, this study constructs a two-mode social network between Chinese listed companies and other participants. To analyze the lag structure of the effect of social network position on innovation, this study uses a panel negative binomial regression model transformed by the Almon polynomial. The results show that a firm does need an advantageous past social network position for innovation. Previous local and global centrality in a social network has a different influence on innovation. For the local centrality indices, degree centrality has a positive impact in the short-term, but has a negative impact in the long-term; the impact of betweenness centrality is not significant in the short-term and is negative in the long run. For the global centrality indices, closeness centrality has a positive influence that decreases with the increase of the time-lag. At the same time, using the method of necessary condition analysis (NCA), this study calculates the bottleneck for a given innovation level. Finally, based on these research conclusions, the theoretical implications and management practice implications are summarized.
Impact of Personality Traits and Entrepreneurship Education on Entrepreneurial Intentions of Business and Engineering Students
Authors: Vodă Ana Iolanda , Florea Nelu
Published: February 2019

Entrepreneurs bring an enormous contribution to a country’s economic growth. Developing individual’s interest into new venture creation represents an important asset, especially for less developed countries where entrepreneurial activities are fundamental in enhancing economic growth. The recent economic crisis turned the attention of European policymakers towards entrepreneurship as a driving force for the creation of new job opportunities, regional/national competitiveness and growth. The aim of this article is to verify what relations are between locus of control, need for achievement and entrepreneurial intention of youth, following a cognitive approach and how much entrepreneurial education consolidates entrepreneurial skills and informs the young that entrepreneurship is a career option. To analyse entrepreneurial intentions, locus of control, need for achievement and entrepreneurial education in the context of Romania, this research used a quantitative design based on the answers to the questionnaire conducted during March 2017 to October 2017 on a sample of 270 students from two important Romanian universities. From the methodological point of view, several hypotheses have been developed and tested using multivariate logistic regression estimates, frequency analysis, internal consistency reliability of the constructs and moderating effects. The results illustrate that locus of control, need for achievement and entrepreneurial education proved to be important determinants for venture creation among young students, both independently and under the action of control variables. Also, respondents’ gender had a significant influence on one’s intention of opening a business in the future, with males being more inclined to become entrepreneurs than females.
Understanding of Public–Private Partnership Stakeholders as a Condition of Sustainable Development
Authors: Wojewnik-Filipkowska Anna , Węgrzyn Joanna
Published: February 2019

The strategic goal of city management is to ensure its sustainable development which requires a balance of rare resources. From the operational perspective, namely projects implementing sustainable development, the balance refers to human resources. They can be classified into the public or private sector and their cooperation is known as Public–Private Partnership (PPP). Building on the concept of sustainable development and stakeholder theory, the research develops a conceptual framework of stakeholder analysis in PPP projects. More generally, the research aims to contribute to a theoretical understanding of the determinants of sustainable city development and PPP success factors. The research claims that the PPP procurement is consistent with sustainable urban development and the PPP model, accompanied by the stakeholder theory, requires evaluation which balances diverse stakeholders’ interests along the triple bottom of sustainable development. The conceptual framework combines stakeholder attributes of preferred benefits and power and urgency. It includes a time and scope perspective. The research has a descriptive but also a normative character as the framework could be helpful to understand and engage stakeholders in sustainable urban development. The developed framework can be considered for the future construction of a model that can be implemented and tested. This theoretical research is based on a literature survey, applying methods of critical analysis and construction. The innovative approach of the research is based on integrated application of already known concepts of sustainable development, stakeholder theory, and Public–Private Partnership, which are all necessary to create a new approach to management of city development consistent with the known facts.
Characteristics Analysis of Freight Mode Choice Model According to the Introduction of a New Freight Transport System
Authors: Shin Seungjin , Roh Hong-Seung , Hur Sung Ho
Published: February 2019

The purpose of this study is to identify the characteristics of freight mode choices made by shippers and carriers with the introduction of a new freight transport system. We set an area in which actual freight transport takes place as the analysis scope and performed a survey of the shippers and carriers that transport containers to identify their stated preference (SP) regarding the new freight mode. The SP survey was carried out through an experimental design and this study considered the three factors of transport time, transport cost, and service level. This study compared and analyzed the models by distance using an individual behavior model. The results of estimating the model showed that the explanatory power of the model classified by distance and the individual parameters have statistical significance. The hit ratio was also high, which confirms that the model was estimated properly. In addition, the range of elasticity and the value of travel time analyzed using the model were evaluated to be appropriate compared to previous studies. The findings of the elasticity analysis show that strategies for reducing the transport cost are effective to increase the demand for the new transport mode. The value of travel time of freight transport was found to be higher than the current value generally applied in Korea. Considering that the value of travel time currently used is based on road freight transport, further research is required to apply a new value of travel time that reflects the characteristics of the new transport mode in the future.