bluuebunny/crossref_metadata_2025 huggingface dataset:
The Energetic Viability of Δ1-Piperideine Dimerization in Lysine-derived Alkaloid Biosynthesis
Authors: Sato Hajime , Uchiyama Masanobu , Saito Kazuki , Yamazaki Mami
Published: August 2018

Lys-derived alkaloids widely distributed in plant kingdom have received considerable attention and have been intensively studied; however, little is known about their biosynthetic mechanisms. In terms of the skeleton formation, for example, of quinolizidine alkaloid biosynthesis, only the very first two steps have been identified and the later steps remain unknown. In addition, there is no available information on the number of enzymes and reactions required for their skeletal construction. The involvement of the Δ 1 -piperideine dimerization has been proposed for some of the Lys-derived alkaloid biosyntheses, but no enzymes for this dimerization reaction have been reported to date; moreover, it is not clear whether this dimerization reaction proceeds spontaneously or enzymatically. In this study, the energetic viability of the Δ 1 -piperideine dimerizations under neutral and acidic conditions was assessed using the density functional theory computations. In addition, a similar type of reaction in the dipiperidine indole alkaloid, nitramidine, biosynthesis was also investigated. Our findings will be useful to narrow down the candidate genes involved in the Lys-derived alkaloid biosynthesis.
Nano and Microsensors for Mammalian Cell Studies
Authors: Voiculescu Ioana , Toda Masaya , Inomata Naoki , Ono Takahito , Li Fang
Published: August 2018

This review presents several sensors with dimensions at the nano- and micro-scale used for biological applications. Two types of cantilever beams employed as highly sensitive temperature sensors with biological applications will be presented. One type of cantilever beam is fabricated from composite materials and is operated in the deflection mode. In order to achieve the high sensitivity required for detection of heat generated by a single mammalian cell, the cantilever beam temperature sensor presented in this review was microprocessed with a length at the microscale and a thickness in the nanoscale dimension. The second type of cantilever beam presented in this review was operated in the resonant frequency regime. The working principle of the vibrating cantilever beam temperature sensor is based on shifts in resonant frequency in response to temperature variations generated by mammalian cells. Besides the cantilever beam biosensors, two biosensors based on the electric cell-substrate impedance sensing (ECIS) used to monitor mammalian cells attachment and viability will be presented in this review. These ECIS sensors have dimensions at the microscale, with the gold films used for electrodes having thickness at the nanoscale. These micro/nano biosensors and their mammalian cell applications presented in the review demonstrates the diversity of the biosensor technology and applications.
A Molecular Dynamics Study of the Mechanical Properties of Twisted Bilayer Graphene
Authors: Liu Aaron , Peng Qing
Published: August 2018

Graphene is one of the most important nanomaterials. The twisted bilayer graphene shows superior electronic properties compared to graphene. Here, we demonstrate via molecular dynamics simulations that twisted bilayer graphene possesses outstanding mechanical properties. We find that the mechanical strain rate and the presence of cracks have negligible effects on the linear elastic properties, but not the nonlinear mechanical properties, including fracture toughness. The “two-peak” pattern in the stress-strain curves of the bilayer composites of defective and pristine graphene indicates a sequential failure of the two layers. Our study provides a safe-guide for the design and applications of multilayer grapheme-based nanoelectronic devices.
Origin of Platinum Group Minerals (PGM) Inclusions in Chromite Deposits of the Urals
Authors: Zaccarini Federica , Garuti Giorgio , Pushkarev Evgeny , Thalhammer Oskar
Published: August 2018

This paper reviews a database of about 1500 published and 1000 unpublished microprobe analyses of platinum-group minerals (PGM) from chromite deposits associated with ophiolites and Alaskan-type complexes of the Urals. Composition, texture, and paragenesis of unaltered PGM enclosed in fresh chromitite of the ophiolites indicate that the PGM formed by a sequence of crystallization events before, during, and probably after primary chromite precipitation. The most important controlling factors are sulfur fugacity and temperature. Laurite and Os–Ir–Ru alloys are pristine liquidus phases crystallized at high temperature and low sulfur fugacity: they were trapped in the chromite as solid particles. Oxygen thermobarometry supports that several chromitites underwent compositional equilibration down to 700 °C involving increase of the Fe3/Fe2 ratio. These chromitites contain a great number of PGM including—besides laurite and alloys—erlichmanite, Ir–Ni–sulfides, and Ir–Ru sulfarsenides formed by increasing sulfur fugacity. Correlation with chromite composition suggests that the latest stage of PGM crystallization might have occurred in the subsolidus. If platinum-group elements (PGE) were still present in solid chromite as dispersed atomic clusters, they could easily convert into discrete PGM inclusions splitting off the chromite during its re-crystallization under slow cooling-rate. The presence of primary PGM inclusions in fresh chromitite of the Alaskan-type complexes is restricted to ore bodies crystallized in equilibrium with the host dunite. The predominance of Pt–Fe alloys over sulfides is a strong indication for low sulfur fugacity, thereby early crystallization of laurite is observed only in one deposit. In most cases, Pt–Fe alloys crystallized and were trapped in chromite between 1300 and 1050 °C. On-cooling equilibration to ~900 °C may produce lamellar unmixing of different Pt–Fe phases and osmium. Precipitation of the Pt–Fe alloys locally is followed by an increase of sulfur fugacity leading to crystallize erlichmanite and Ir–Rh–Ni–Cu sulfides, occurring as epitaxic overgrowth on the alloy. There is evidence that the system moved quickly into the stabilization field of Pt–Fe alloys by an increase of the oxygen fugacity marked by an increase of the magnetite component in the chromite. In summary, the data support that most of the primary PGM inclusions in the chromitites of the Urals formed in situ, as part of the chromite precipitation event. However, in certain ophiolitic chromitites undergoing annealing conditions, there is evidence for subsolidus crystallization of discrete PGM from PGE atomic-clusters occurring in the chromite. This mechanism of formation does not require a true solid solution of PGE in the chromite structure.
Correlation between Quality and Geographical Origins of Poria cocos Revealed by Qualitative Fingerprint Profiling and Quantitative Determination of Triterpenoid Acids
Authors: Zhu Li-Xia , Xu Jun , Wang Ru-Jing , Li Hong-Xiang , Tan Yu-Zhu , Chen Hu-Biao , Dong Xiao-Ping , Zhao Zhong-Zhen
Published: August 2018

Poria cocos (Schw.) Wolf (PC) is a well-known saprophytic fungus, and its sclerotium without the epidermis (PCS) is widely used in traditional Chinese medicine and as a functional food in many countries. PCS is normally collected from multiple geographical regions, but whether and how the quality of PCS correlates with where it grows have not been determined. This correlation could be significant both for quality control and optimum utilization of PCS as a natural resource. In this study, a qualitative fingerprint profiling method performed by ultra-performance liquid chromatography (UHPLC) with diode array detection (DAD) combining quadrupole time-of-flight-mass spectrometry (QTOF-MS/MS) and a quantitative UHPLC coupled with triple quadrupole mass spectrometry (QqQ-MS/MS) approach were established to investigate whether and how the quality of PCS correlates with its collection location. A standard fingerprint of PCS was generated by median simulation of 25 tested samples collected from four main producing areas of China, and similarity analysis was applied to evaluate the similarities between the fingerprints of samples and the standard fingerprint. Twenty three common peaks occurring in the fingerprint were unequivocally or tentatively identified by UHPLC-QTOF-MS/MS. Meanwhile, principal component analysis (PCA), supervised orthogonal partial least squares-discriminate analysis (OPLS-DA) and hierarchical cluster analysis (HCA) were employed to classify 25 batches of PCS samples into four groups, which were highly consistent with the four geographical regions. Ten compounds were screened out as potential markers to distinguish the quality of PCS. Nine triterpene acids, including five compounds that played important roles in the clusters between different samples collected from the four collection locations, were simultaneously quantified by using the multiple reaction monitoring (MRM) mode of UHPLC-QqQ-MS/MS. The current strategy not only clearly expounded the correlation between quality and geographical origins of PCS, but also provided a fast, accurate and comprehensive qualitative and quantitative method for assessing the quality of PCS.
5-Hydroxymethylfurfural (HMF) Production from Real Biomasses
Authors: Menegazzo Federica , Ghedini Elena , Signoretto Michela
Published: August 2018

The present paper reviews recent advances on the direct synthesis of 5-hydroxymethylfurfural (HMF) from different kinds of raw biomasses. In particular, in the paper HMF production from: (i) edible biomasses; (ii) non-edible lignocellulosic biomasses; (iii) food wastes (FW) have been reviewed. The different processes and catalytic systems have been reviewed and their merits, demerits and requirements for commercialisation outlined.
A New Chemoenzymatic Synthesis of the Chiral Key Intermediate of the Antiepileptic Brivaracetam
Authors: Ciceri Samuele , Grisenti Paride , Reza Elahi Shahrzad , Ferraboschi Patrizia
Published: August 2018

Brivaracetam is a new anticonvulsant compound, recently approved as an antiepileptic drug. This drug substance presents a 4-substituted pyrrolidone structure: the (4R)-configuration of the stereocenter present on the heterocyclic ring is the main target of the synthesis. The described method allows to prepare the suitable optically pure 2-substituted primary alcohol by means of a Pseudomonas fluorescens lipase-catalyzed transesterification. The obtained (2R)-alcohol was easily transformed into the (3R)-3-propylbutyrolactone, an advanced intermediate of brivaracetam. The described synthetic pathway is completed with the chromatographic methods and the NMR analyses necessary to establish the chemical and the optical purity of the intermediates and of the final lactone.
Machine Learning for Drug-Target Interaction Prediction
Authors: Chen Ruolan , Liu Xiangrong , Jin Shuting , Lin Jiawei , Liu Juan
Published: August 2018

Identifying drug-target interactions will greatly narrow down the scope of search of candidate medications, and thus can serve as the vital first step in drug discovery. Considering that in vitro experiments are extremely costly and time-consuming, high efficiency computational prediction methods could serve as promising strategies for drug-target interaction (DTI) prediction. In this review, our goal is to focus on machine learning approaches and provide a comprehensive overview. First, we summarize a brief list of databases frequently used in drug discovery. Next, we adopt a hierarchical classification scheme and introduce several representative methods of each category, especially the recent state-of-the-art methods. In addition, we compare the advantages and limitations of methods in each category. Lastly, we discuss the remaining challenges and future outlook of machine learning in DTI prediction. This article may provide a reference and tutorial insights on machine learning-based DTI prediction for future researchers.
Comparative Phytochemical Profiles and Antioxidant Enzyme Activity Analyses of the Southern Highbush Blueberry (Vaccinium corymbosum) at Different Developmental Stages
Authors: Sun Yueting , Li Min , Mitra Sangeeta , Hafiz Muhammad Rizwan , Debnath Biswojit , Lu Xiaocao , Jian Hongxiang , Qiu Dongliang
Published: August 2018

In this study, the fruit quality, anthocyanin content and antioxidant enzyme activities of skin and pulp of southern blueberries (Vaccinium corymbosum) from China y at five developmental stages (green, pink, red, purple and blue) were investigated and anthocyanins were characterized and quantified by HPLC during the considered developmental stages. The results indicatated that the contents of phenolic, flavonoids and anthocyanin as well as antioxidant enzyme activities varied depending on the developmental stages. The correlation values between total phenolic content (TPC), total flavonoids content (TFC) and total anthocyanin content (TAC) were significant. The highest activity of peroxidase (POD) and catalase (CAT) was found in red fruit, and the variety of monomeric anthocyanin increased gradually, skin from blue fruit possessed higher TAC. However, the highest activity of polyphenol oxidase (PPO) and superoxide dismutase (SOD) were detected in green and blue fruit, respectively. In the present work, the differences regarding phytochemical profiles and antioxidant enzyme activities were mainly correlated with developmental stages of fruit.
Oxygen-Carrying Micro/Nanobubbles: Composition, Synthesis Techniques and Potential Prospects in Photo-Triggered Theranostics
Authors: Khan Muhammad Saad , Hwang Jangsun , Lee Kyungwoo , Choi Yonghyun , Kim Kyobum , Koo Hyung-Jun , Hong Jong Wook , Choi Jonghoon
Published: August 2018

Microbubbles and nanobubbles (MNBs) can be prepared using various shells, such as phospholipids, polymers, proteins, and surfactants. MNBs contain gas cores due to which they are echogenic and can be used as contrast agents for ultrasonic and photoacoustic imaging. These bubbles can be engineered in various sizes as vehicles for gas and drug delivery applications with novel properties and flexible structures. Hypoxic areas in tumors develop owing to an imbalance of oxygen supply and demand. In tumors, hypoxic regions have shown more resistance to chemotherapy, radiotherapy, and photodynamic therapies. The efficacy of photodynamic therapy depends on the effective accumulation of photosensitizer drug in tumors and the availability of oxygen in the tumor to generate reactive oxygen species. MNBs have been shown to reverse hypoxic conditions, degradation of hypoxia inducible factor 1α protein, and increase tissue oxygen levels. This review summarizes the synthesis methods and shell compositions of micro/nanobubbles and methods deployed for oxygen delivery. Methods of functionalization of MNBs, their ability to deliver oxygen and drugs, incorporation of photosensitizers and potential application of photo-triggered theranostics, have also been discussed.
Residue Depletion of Florfenicol and Florfenicol Amine in Broiler Chicken Claws and a Comparison of Their Concentrations in Edible Tissues Using LC–MS/MS
Authors: Pokrant Ekaterina , Riquelme Ricardo , Maddaleno Aldo , San Martín Betty , Cornejo Javiera
Published: August 2018

Antimicrobial residues might persist in products and by-products destined for human or animal consumption. Studies exploring the depletion behavior of florfenicol residues in broiler chicken claws are scarce, even though claws can enter the food chain directly or indirectly. Hence, this study intended to assess the concentrations of florfenicol (FF) and florfenicol amine (FFA)—its active metabolite—in chicken claws from birds that were treated with a therapeutic dose of florfenicol. Furthermore, concentrations of these analytes in this matrix were compared with their concentrations in edible tissues at each sampling point. A group of 70 broiler chickens were raised under controlled conditions and used to assess residue depletion. Sampling points were on days 5, 10, 20, 25, 30, 35, and 40 after ceasing treatment, thus extending beyond the withdrawal period established for muscle tissue (30 days). Analytes were extracted using HPLC-grade water and acetone, and dichloromethane was used for the clean-up stage. Liquid chromatography coupled to mass spectroscopy detection (LC–MS/MS) was used to detect and quantify the analytes. The analytical methodology developed in this study was validated in-house and based on the recommendations described in the Commission Decision 2002/657/EC from the European Union. Analyte concentrations were calculated by linear regression analysis of calibration curves that were fortified using an internal standard of chloramphenicol-d5 (CAF-d5). The depletion time of FF and FFA was set at 74 days in claws, based on a 95% confidence level and using the limit of detection (LOD) as the cut-off point. Our findings show that FF and FFA can be found in chicken claws at higher concentrations than in muscle and liver samples at each sampling point.
Tracing the Thermal History of Seafood Products through Lysophospholipid Analysis by Hydrophilic Interaction Liquid Chromatography–Electrospray Ionization Fourier Transform Mass Spectrometry
Authors: Losito Ilario , Facchini Laura , Catucci Rosa , Calvano Cosima Damiana , Cataldi Tommaso R. I. , Palmisano Francesco
Published: August 2018

Low temperature treatments commonly applied to seafood products have been shown to influence their phospholipid (PL) profile through enzymatic hydrolysis. In the present study, the generation of lysophospholipids (LPL) resulting from this process was systematically investigated for selected, commercially relevant seafood products, namely oysters, clams, octopuses, and shrimps. These products were subjected to thermal treatments like refrigeration or freezing after being purchased as fresh, defrozen, or frozen products depending on the case. The coupling between hydrophilic interaction liquid chromatography (HILIC) and electrospray ionization with high resolution/accuracy Fourier transform mass spectrometry (ESI-FTMS) was exploited to evaluate the PL profile of the cited products, especially the incidence of LPL related to the two main PL classes of seafood products—phosphatidylcholines (PC) and phosphatidylethanolamines (PE)—in the lipid extracts. The lyso forms of PE (LPE) were found to be generally more sensitive than those of PC (LPC) to thermal treatments, usually exhibiting a significant increase upon prolonged refrigeration at 4 °C in all types of investigated products except European flat oysters. Moreover, the distinction between fresh and frozen or defrozen products could be achieved in the case of octopuses and shrimps, respectively.
Phosphate-Catalyzed Succinimide Formation from an NGR-Containing Cyclic Peptide: A Novel Mechanism for Deammoniation of the Tetrahedral Intermediate
Authors: Kirikoshi Ryota , Manabe Noriyoshi , Takahashi Ohgi
Published: August 2018

Spontaneous deamidation in the Asn-Gly-Arg (NGR) motif that yields an isoAsp-Gly-Arg (isoDGR) sequence has recently attracted considerable attention because of the possibility of application to dual tumor targeting. It is well known that Asn deamidation reactions in peptide chains occur via the five-membered ring succinimide intermediate. Recently, we computationally showed by the B3LYP density functional theory method, that inorganic phosphate and the Arg side chain can catalyze the NGR deamidation using a cyclic peptide, c[CH2CO–NGRC]–NH2. In this previous study, the tetrahedral intermediate of the succinimide formation was assumed to be readily protonated at the nitrogen originating from the Asn side chain by the solvent water before the release of an NH3 molecule. In the present study, we found a new mechanism for the decomposition of the tetrahedral intermediate that does not require the protonation by an external proton source. The computational method is the same as in the previous study. In the new mechanism, the release of an NH3 molecule occurs after a proton exchange between the peptide and the phosphate and conformational changes. The rate-determining step of the overall reaction course is the previously reported first step, i.e., the cyclization to form the tetrahedral intermediate.
Protective Properties of a Microstructure Composed of Barrier Nanostructured Organics and SiOx Layers Deposited on a Polymer Matrix
Authors: Prikryl Radek , Otrisal Pavel , Obsel Vladimir , Svorc Lubomír , Karkalic Radovan , Buk Jan
Published: August 2018

The SiOx barrier nanocoatings have been prepared on selected polymer matrices to increase their resistance against permeation of toxic substances. The aim has been to find out whether the method of vacuum plasma deposition of SiOx barrier nanocoatings on a polyethylene terephthalate (PET) foil used by Aluminium Company of Canada (ALCAN) company (ALCAN Packaging Kreuzlingen AG (SA/Ltd., Kreuzlingen, Switzerland) within the production of CERAMIS® packaging materials with barrier properties can also be used to increase the resistance of foils from other polymers against the permeation of organic solvents and other toxic liquids. The scanning electron microscopy (SEM) microstructure of SiOx nanocoatings prepared by thermal deposition from SiO in vacuum by the Plasma Assisted Physical Vapour Deposition (PA-PVD) method or vacuum deposition of hexamethyldisiloxane (HMDSO) by the Plasma-enhanced chemical vapour deposition (PECVD) method have been studied. The microstructure and behavior of samples when exposed to a liquid test substance in relation to the barrier properties is described.
Insights into Bacterial Cellulose Biosynthesis from Different Carbon Sources and the Associated Biochemical Transformation Pathways in Komagataeibacter sp. W1
Authors: Wang Shan-Shan , Han Yong-He , Chen Jia-Lian , Zhang Da-Chun , Shi Xiao-Xia , Ye Yu-Xuan , Chen Deng-Long , Li Min
Published: August 2018

Cellulose is the most abundant and widely used biopolymer on earth and can be produced by both plants and micro-organisms. Among bacterial cellulose (BC)-producing bacteria, the strains in genus Komagataeibacter have attracted wide attention due to their particular ability in furthering BC production. Our previous study reported a new strain of genus Komagataeibacter from a vinegar factory. To evaluate its capacity for BC production from different carbon sources, the present study subjected the strain to media spiked with 2% acetate, ethanol, fructose, glucose, lactose, mannitol or sucrose. Then the BC productivity, BC characteristics and biochemical transformation pathways of various carbon sources were fully investigated. After 14 days of incubation, strain W1 produced 0.040–1.529 g L−1 BC, the highest yield being observed in fructose. Unlike BC yields, the morphology and microfibrils of BCs from different carbon sources were similar, with an average diameter of 35–50 nm. X-ray diffraction analysis showed that all membranes produced from various carbon sources had 1–3 typical diffraction peaks, and the highest crystallinity (i.e., 90%) was found for BC produced from mannitol. Similarly, several typical spectra bands obtained by Fourier transform infrared spectroscopy were similar for the BCs produced from different carbon sources, as was the Iα fraction. The genome annotation and Kyoto Encyclopedia of Genes and Genomes analysis revealed that the biochemical transformation pathways associated with the utilization of and BC production from fructose, glucose, glycerol, and mannitol were found in strain W1, but this was not the case for other carbon sources. Our data provides suggestions for further investigations of strain W1 to produce BC by using low molecular weight sugars and gives clues to understand how this strain produces BC based on metabolic pathway analysis.
An Evaluation of MODIS-Retrieved Aerosol Optical Depth over AERONET Sites in Alaska
Authors: McPhetres Alyson , Aggarwal Srijan
Published: August 2018

The air quality monitoring network in Alaska is currently limited to ground-based observations in urban areas and national parks, leaving a large proportion of the state unmonitored. The use of Moderate Resolution Imaging Spectroradiometer MODIS aerosol optical depth (AOD) to estimate ground-level particulate pollution concentrations has been successfully demonstrated around the world and could potentially be used in Alaska. In this work, MODIS AOD measurements at 550 nm were validated against AOD derived from two ground-based Aerosol Robotic Network (AERONET) sunphotometers in Alaska, located at Utqiagvik (previously known as Barrow) and Bonanza Creek, to determine if MODIS AOD from the Terra and Aqua satellites could be used to estimate ground-level particulate pollution concentrations. The MODIS AOD was obtained from MODIS collection 6 using the dark target Land and Ocean algorithms from years 2000 to 2014. MODIS data could only be obtained between the months of April and October; therefore, it was only evaluated for those months. Individual and combined Terra and Aqua MODIS data were considered. The results showed that MODIS collection 6 products at 10-km resolution for Terra and Aqua combined are not valid over land but are valid over the ocean. Note that the individual Terra and Aqua MODIS collection 6 AOD products at 10-km resolution are valid over land individually but not when combined. Results also suggest the MODIS collection 6 AOD products at 3-km resolution are valid over land and ocean and perform better over land than the 10-km product. These findings indicate that MODIS collection 6 AOD products can be used quantitatively in air quality applications in Alaska during the summer months.
Hurricane Maria in the U.S. Caribbean: Disturbance Forces, Variation of Effects, and Implications for Future Storms
Authors: Van Beusekom Ashley E. , Álvarez-Berríos Nora L. , Gould William A. , Quiñones Maya , González Grizelle
Published: August 2018

The impact of Hurricane Maria on the U.S. Caribbean was used to study the causes of remotely-sensed spatial variation in the effects of (1) vegetation index loss and (2) landslide occurrence. The vegetation index is a measure of canopy ‘greenness’, a combination of leaf chlorophyll, leaf area, canopy cover and structure. A generalized linear model was made for each kind of effect, using idealized maps of the hurricane forces, along with three landscape characteristics that were significantly associated. In each model, one of these characteristics was forest fragmentation, and another was a measure of disturbance-propensity. For the greenness loss model, the hurricane force was wind, the disturbance-propensity measure was initial greenness, and the third landscape characteristic was fraction forest cover. For the landslide occurrence model, the hurricane force was rain, the disturbance-propensity measure was amount of land slope, and the third landscape characteristic was soil clay content. The model of greenness loss had a pseudo R2 of 0.73 and showed the U.S. Caribbean lost 31% of its initial greenness from the hurricane, with 51% lost from the initial in the Luquillo Experimental Forest (LEF) from Hurricane Maria along with Hurricane Irma. More greenness disturbance was seen in areas with less wind sheltering, higher elevation and topographic sides. The model of landslide occurrence had a pseudo R2 of 0.53 and showed the U.S. Caribbean had 34% of its area and 52% of the LEF area with a landslide density of at least one in 1 km2 from Hurricane Maria. Four experiments with parameters from previous storms of wind speed, storm duration, rainfall, and forest structure over the same storm path and topographic landscape were run as examples of possible future scenarios. While intensity of the storm makes by far the largest scenario difference, forest fragmentation makes a sizable difference especially in vulnerable areas of high clay content or high wind susceptibility. This study showed the utility of simple hurricane force calculations connected with landscape characteristics and remote-sensing data to determine forest susceptibility to hurricane effects.
Assessing the Resilience of Coastal Wetlands to Extreme Hydrologic Events Using Vegetation Indices: A Review
Authors: Tahsin Subrina , Medeiros Stephen C. , Singh Arvind
Published: August 2018

Coastal wetlands (CWs) offer numerous imperative functions that support a diverse array of life forms that are poorly adapted for other environments and provide an economic base for human communities. Unfortunately, CWs have been experiencing significant threats due to meteorological and climatic fluctuations as well as anthropogenic impacts. The wetlands and marshes in Apalachicola Bay, Florida have endured the impacts of several extreme hydrologic events (EHEs) over the past few decades. These extreme hydrologic events include drought, hurricane, heavy precipitation and fluvial flooding. Remote sensing has been used and continues to demonstrate promise for acquiring spatial and temporal information about CWs thereby making it easier to track and quantify long term changes driven by EHEs. These wetland ecosystems are also adversely impacted by increased human activities such as wetland conversion to agricultural, aquaculture, industrial or residential use; construction of dikes along the shoreline; and sprawl of built areas. In this paper, we review previous works on coastal wetland resilience to EHEs. We synthesize these concepts in the context of remote sensing as the primary assessment tool with focus on derived vegetation indices to monitor CWs at regional and global scales.
Blind UAV Images Deblurring Based on Discriminative Networks
Authors: Wang Ruihua , Ma Guorui , Qin Qianqing , Shi Qiang , Huang Juntao
Published: August 2018

Unmanned aerial vehicles (UAVs) have become an important technology for acquiring high-resolution remote sensing images. Because most space optical imaging systems of UAVs work in environments affected by vibrations, the optical axis motion and image plane jitter caused by these vibrations easily result in blurring of UAV images. In the paper; we propose an advanced UAV image deblurring method based on a discriminative model comprising a classifier for blurred and sharp UAV images which is embedded into the maximum a posteriori framework as a regularization term that constantly optimizes ill-posed problem of blind image deblurring to obtain sharper UAV images. Compared with other methods, the results show that in image deblurring experiments using both simulated and real UAV images the proposed method delivers sharper images of various ground objects.
An Energy Conserving and Transmission Radius Adaptive Scheme to Optimize Performance of Energy Harvesting Sensor Networks
Authors: Ju Xin , Liu Wei , Zhang Chengyuan , Liu Anfeng , Wang Tian , Xiong Neal N. , Cai Zhiping
Published: August 2018

In energy harvesting wireless sensor networks (EHWSNs), the energy tension of the network can be relieved by obtaining the energy from the surrounding environment, but the cost on hardware cannot be ignored. Therefore, how to minimize the cost of energy harvesting hardware to reduce the network deployment cost, and further optimize the network performance, is still a challenging issue in EHWSNs. In this paper, an energy conserving and transmission radius adaptive (ECTRA) scheme is proposed to reduce the cost and optimize the performance of solar-based EHWSNs. There are two main innovations of the ECTRA scheme. Firstly, an energy conserving approach is proposed to conserve energy and avoid outage for the nodes in hotspots, which are the bottleneck of the whole network. The novelty of this scheme is adaptively rotating the transmission radius. In this way, the nodes with maximum energy consumption are rotated, balancing energy consumption between nodes and reducing the maximum energy consumption in the network. Therefore, the battery storage capacity of nodes and the cost on hardware. Secondly, the ECTRA scheme selects a larger transmission radius for rotation when the node can absorb enough energy from the surroundings. The advantages of using this method are: (a) reducing the energy consumption of nodes in near-sink areas, thereby reducing the maximum energy consumption and allowing the node of the hotspot area to conserve energy, in order to prevent the node from outage. Hence, the network deployment costs can be further reduced; (b) reducing the network delay. When a larger transmission radius is used to transmit data in the network, fewer hops are needed by data packet to the sink. After the theoretical analyses, the results show the following advantages compared with traditional method. Firstly, the ECTRA scheme can effectively reduce deployment costs by 29.58% without effecting the network performance as shown in experiment analysis; Secondly, the ECTRA scheme can effectively reduce network data transmission delay by 44–71%; Thirdly, the ECTRA scheme shows a better balance in energy consumption and the maximum energy consumption is reduced by 27.89%; And lastly, the energy utilization rate is effectively improved by 30.09–55.48%.
The Profitability of Residential Photovoltaic Systems. A New Scheme of Subsidies Based on the Price of CO2 in a Developed PV Market
Authors: D’Adamo Idiano
Published: August 2018

Photovoltaic (PV) resource drives the clean global economy of the future. Its sustainability is widely confirmed in literature, however some countries present a growth very low in the last years. A new policy proposal is examined in this work. It aims to stimulate a new diffusion of PV plants in mature markets (e.g., Italy) regarding residential consumers. The subsidy is given to the amount of energy produced by PV plant for a period of 20 years (equal to its lifetime) and its value is calculated according to the scheme of European Emissions Trading System (EU ETS). Discounted Cash Flow (DCF) is used as economic method and two indexes are proposed: Net Present Value (NPV) and Discounted Payback Time (DPBT). The baseline case studies vary in function of two variables; (i) the share of self-consumption (30%, 40% and 50%) and (ii) the price of emissions avoided (10, 35 and 70 € per ton of CO2eq). Results confirms the environmental advantages of PV sources as alternative to the use of fossil fuels (685 gCO2eq/kWh) and economic opportunities are verified in several scenarios (from 48 €/kW to 1357 €/kW). In particular, the profitability of PV systems is greater with a subsidized rate of fiscal deduction of 50% in comparison to subsidies with a value of carbon dioxide lower than 18.50 €/tCO2eq.
Wetland Raised-Field Agriculture and Its Contribution to Sustainability: Ethnoecology of a Present-Day African System and Questions about Pre-Columbian Systems in the American Tropics
Authors: Comptour Marion , Caillon Sophie , Rodrigues Leonor , McKey Doyle
Published: August 2018

One adaptation for farming wetlands is constructing raised fields (RF), i.e., elevated earth structures. Studies of RF agriculture have focused mostly on the vestiges of RF that were cultivated by pre-Columbian populations in the Americas. Ironically, whereas RF agriculture is still practiced nowadays in many parts of the world, including the Congo Basin, these actively farmed RF have received scant attention. Yet, studying how RF function today can shed new light on ongoing debates about pre-Columbian RF agriculture. Also, in a context of climate change and widespread degradation of wetlands, the study of RF agriculture can help us evaluate its potential as part of an environmentally sustainable use of wetlands. We carried out an ethnoecological study of RF agriculture combining qualitative and quantitative methods over a total of eight months’ fieldwork in the Congo Basin. We found that RF show great diversity in size and shape and perform several functions. Incorporation of grasses such as green manure, allows RF to produce high yields, and RF agriculture decreases flooding risk. However, it is labor-intensive and is likely always only one component of a multi-activity subsistence system, in which fishing plays a great role, that is both resilient and sustainable.
On Non-Linear Behavior of Viscosity in Low-Concentration Solutions and Aggregate Structures
Authors: Oikonomou Vasilis K.
Published: August 2018

In this paper, an experimental method that may reveal possible aggregate symmetrical structures in highly diluted solutions is proposed, generated by the method of the release activity, which is not yet completely proven. The release activity phenomenon (regardless of whether or not it is real) could be viewed as being quite controversial. However, the focus of this paper is to reveal any possible higher-order, pragmatic, underlying symmetry or structure supporting this theory, by proposing an experiment based on viscosity. Our proposal is based on the sequential measurement of the viscosity of a highly diluted solution and the perturbative expansion of the viscosity as a function of the concentration. The coefficients of this perturbative expansion directly quantify the modification of the hydrodynamic flow around particles and around higher-order structures. Any deviation from a linear dependence of the viscosity, as a function of the concentration, could potentially reveal a collective structure of some sort, or some symmetrical pattern in the solvent. We describe our experimental proposal for non-electrolyte solutes, and future directions for revealing collective structures in solutions are discussed as related to the release activity method. Regardless of whether or not the release activity is pragmatic, it needs to be scrutinized in order to reveal its inner workings. Finally, some theoretical arguments are presented to support the proposal.
Water Footprint Accounting Along the Wheat-Bread Value Chain: Implications for Sustainable and Productive Water Use Benchmarks
Authors: Matohlang Mohlotsane Pascalina , Owusu-Sekyere Enoch , Jordaan Henry , Barnard Jonannes Hendrikus , Van Rensburg Leon Daniel
Published: August 2018

Efficient and wise management of freshwater resources in South Africa has become critical because of the alarming freshwater scarceness. The situation requires a thorough examination of how water is utilized across various departments that use water. This paper reports on an examination of the water footprint and economic water productivities of the wheat-bread value chain. The assessment methodology of the Water Footprint Network was employed. The findings reveal that 954.07 m3 and 1026.07 m3 of water are utilized in the production of a ton of wheat flour in Bainsvlei and Clovelly in South Africa. The average water footprint for wheat bread was 954.53 m3 per ton in Bainsvlei and 1026.53 m3 per ton in Clovelly. More than 99% of the water is used in producing the grain at the farm level. The processing stage of the value chain uses less than 1% of the total water footprint. About 80% of all the water utilised along the wheat bread value chain is attributed to blue water. The findings revealed a significant shift from green water consumption to higher blue water use, and this is a major concern for water users and stakeholders along the wheat-bread value chain, given that blue water is becoming scarce in South Africa. The groundwater contributes about 34% and 42% of the average total water footprint of wheat at the farm level in Clovelly and Bainsvlei, respectively, suggesting the need to have an idea of the contribution of groundwater in water footprint evaluation and water management decision of farmers. This insight will aid in minimizing irrigation water use and pressure on groundwater resources. A total of ZAR 4.27 is obtained for every m3 of water utilized along the wheat-bread value chain. Water footprint assessment has moved away from sole indicator assessment, as a deeper awareness of and insight into the productive use of water at different stages has become vital for policy. To make a correct judgment and to assess the efficient and wise use of water, there is a need for catchment- or region-specific water footprint benchmarks, given that water footprint estimates and economic water productivities vary from one geographical area to another.
Impact of Rain Gauges Distribution on the Runoff Simulation of a Small Mountain Catchment in Southern Ecuador
Authors: Sucozhañay Adrián , Célleri Rolando
Published: August 2018

In places with high spatiotemporal rainfall variability, such as mountain regions, input data could be a large source of uncertainty in hydrological modeling. Here we evaluate the impact of rainfall estimation on runoff modeling in a small páramo catchment located in the Zhurucay Ecohydrological Observatory (7.53 km2) in the Ecuadorian Andes, using a network of 12 rain gauges. First, the HBV-light semidistributed model was analyzed in order to select the best model structure to represent the observed runoff and its subflow components. Then, we developed six rainfall monitoring scenarios to evaluate the impact of spatial rainfall estimation in model performance and parameters. Finally, we explored how a model calibrated with far-from-perfect rainfall estimation would perform using new improved rainfall data. Results show that while all model structures were able to represent the overall runoff, the standard model structure outperformed the others for simulating subflow components. Model performance (NSeff) was improved by increasing the quality of spatial rainfall estimation from 0.31 to 0.80 and from 0.14 to 0.73 for calibration and validation period, respectively. Finally, improved rainfall data enhanced the runoff simulation from a model calibrated with scarce rainfall data (NSeff 0.14) from 0.49 to 0.60. These results confirm that in mountain regions model uncertainty is highly related to spatial rainfall and, therefore, to the number and location of rain gauges.
Exploring the Effects of Tourism and Economic Growth in Fiji: Accounting for Capital, Labor, and Structural Breaks
Authors: Kumar Nikeel , Kumar Ronald Ravinesh , Patel Arvind , Stauvermann Peter Josef
Published: August 2018

Fiji's tourism industry has evolved considerably in the past 30 years with past and present governments striving to support and promote the sector despite competing development priorities. This study examines the effects of tourism on the economic growth of Fiji, a small island economy,
over the period 1975 to 2015. Using a neoclassical framework and the autoregressive distributed lag bound procedure, the short-run and the long-run effects are explored while accounting for structural breaks. The long-run and short-run results indicate that a 1% increase in visitor arrivals
contribute about 0.13% and 0.20% to the per capita income, respectively. Additionally, a unidirectional causality from economic growth to tourism and a mutually reinforcing effect between capital investment and tourism are noted. Thus, greater impact of tourism on the economic growth can be
realized through tourism-related investment activities such as improvements in airports, roads, transportation, telecommunications, financial sector, technology, and natural parks and beaches.
Rotation in the NGC 1333 IRAS 4C Outflow
Authors: Zhang Yichen , Higuchi Aya E. , Sakai Nami , Oya Yoko , López-Sepulcre Ana , Imai Muneaki , Sakai Takeshi , Watanabe Yoshimasa , Ceccarelli Cecilia , Lefloch Bertrand , Yamamoto Satoshi
Published: August 2018

We report molecular line observations of the NGC 1333 IRAS 4C outflow in the Perseus Molecular Cloud with the Atacama Large Millimeter/Submillimeter Array. The CCH and CS emission reveal an outflow cavity structure with clear signatures of rotation with respect to the outflow axis. The rotation is detected from about 120 au up to about 1400 au above the envelope/disk midplane. As the distance to the central source increases, the rotation velocity of the outflow decreases while the outflow radius increases, which gives a flat specific angular momentum distribution along the outflow. The mean specific angular momentum of the outflow is about 100

. On the basis of reasonable assumptions on the outward velocity of the outflow and the protostar mass, we estimate the range of outflow-launching radii to be 5–15 au. Such a launching radius rules out that this outflow is launched as an X-wind, but rather, it is more consistent to be a slow disk wind launched from relatively large radii on the disk. The radius of the centrifugal barrier is roughly estimated, and the role of the centrifugal barrier in the outflow launching is discussed.
2-phenyl-1-(3-pyrrolidin-1-il-propyl)-1 H-indole hydrochloride (SS-68): Antiarrhythmic and cardioprotective activity and its molecular mechanisms of action (Part I)
Authors: Bogus Saida K. , Galenko-Yaroshevsky Pavel A. , Suzdalev Konstantin F. , Sukoyan Galina V. , Abushkevich Valery G.
Published: August 2018

Introduction. The problem of heart rhythm disturbances is one of the most urgent topics of modern cardiology. According to the currently available concepts, 1,2- and 1,3-disubstituted aminoindole derivatives, which compound 2-phenyl-1-(3-pyrrolidin-1-il-propyl)-1H-indole hydrochloride (SS-68) belongs to, are a promising chemical group in terms of their cardio-pharmacological activity.

Materials and methods. To study the anti-arrhythmic activity of SS-68 compound, the following models were used: 1) Models of cardiogenic arrhythmia: aconitine-inducedic, calcium chloride-induced, barium chloride-induced, cesium chloride-induced, adrenaline model of arrhythmia, strophanthine-induced arrhythmias, as well as arrhythmias caused by electrostimulation and acute myocardial ischemia; 2) neurogenic arrhythmias: arrhythmias caused by administration of aconitine, strophanthine K, cesium chloride into the IV ventricle of the brain and also by applying carbachol on the somatosensory cortex. To assess the antianginal activity of SS-68 in various models, the effect of this drug and comparators on the intact and ischemic myocardium was studied.

Results. It was found that with cardiogenic arrhythmias, SS-68 compound exhibits a pronounced antiarrhythmic effect and brings to normal the electrophysiological pattern of the heart, in most cases exceeding the analogous effect of reference drugs (amiodarone, lidocaine, aymaline, ethacizine, etmozine, quinidine anaprilin). In neurogenic arrhythmias, SS-68 also had a stopping effect, and, in addition, reduced the epileptiform activity of the brain in the model with the application of carbachol on the somatosensory cortex. In the study of antianginal and coronary vasolidating activities, SS-68 demonstrated pronounced thrombolytic and anti-ischemic activities, manifested in an increase in the coronary blood flow, a positive effect on ST-segment depression, and a decrease in the area of necrosis in experimental myocardial infarction.

Discussion. The antiarrhythmic and antianginal activities of SS-68 compound create the prerequisites for further study of the pharmacological properties of this molecule. In addition, it seems appropriate to continue studying the pharmacodynamics, pharmacokinetics and molecular mechanisms of SS-68 action.

Conclusions. SS-68 compound is a promising pharmacological agent with a high activity towards various electrophysiological disorders in the heart, and, in addition, it has significant antiischemic and coronary vasolidating properties.
L’industrie du gaz en Espagne dans la période de l’entre-deux-guerres
Authors: Fernández Paradas Mercedes , Larrinaga Carlos
Published: August 2018

L'article donne un aperçu de l'industrie du gaz en Espagne pendant l'entre-deux-guerres. Il s'agit d'une période particulièrement pertinente, de 1919, la première année après la Première Guerre mondiale, à 1935, l'année avant le déclenchement de la guerre civile espagnole. Nous parlons d'une période importante pour deux raisons. Tout d'abord, parce que pendant une grande partie de cette période, entre 1913 et 1929, l'Espagne a connu quelques années de prospérité économique qui se sont matérialisées par un progrès substantiel dans le processus d'industrialisation, avec une amélioration conséquente du niveau de vie et, par conséquent, de la consommation. Et deuxièmement, parce que le secteur gazier espagnol a connu de graves difficultés pendant la Grande Guerre, à laquelle s'est ajouté par la suite le développement spectaculaire de l'électricité, ce qui a placé le gaz dans une situation délicate, de sorte qu'il a dû revoir sa stratégie pour pouvoir continuer à croître en Espagne.