bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Photovoltaics (PV) in the Present and Future Situation of Suriname
Authors: Raghoebarsing Amrita , Reinders Angèle
Published: January 2019

The aim of this paper is to give an overview of the energy sector and the current status of photovoltaic (PV) systems in Suriname and to investigate which role PV systems can play in this country’s future energy transition. At this moment, 64% of the power is available from diesel/heavy fuel oil (HFO) gensets while 36% is available from renewables namely hydroelectric power systems and PV systems. Suriname has renewable energy (RE) targets for 2017 and 2022 which already have been achieved by this 36%. However, the RE target of 2027 of 47% must be achieved yet. As there is abundant irradiance available, on an average 1792 kWh/m2/year and because several PV systems have already been successfully implemented, PV can play an important role in the energy transition of Suriname. In order to achieve the 2027 target with only PV systems, an additional 110 MWp of installed PV capacity will be required. Governmental and non-governmental institutes have planned PV projects. If these will be executed in the future than annually 0.8 TWh electricity will be produced by PV systems. In order to meet the electricity demand of 2027 fully, 2.2 TWh PV electricity will be required which implies that more PV systems must be implemented in Suriname besides the already scheduled ones.
Risk Assessment and Its Visualization of Power Tower under Typhoon Disaster Based on Machine Learning Algorithms
Authors: Hou Hui , Yu Shiwen , Wang Hongbin , Huang Yong , Wu Hao , Xu Yan , Li Xianqiang , Geng Hao
Published: January 2019

For power system disaster prevention and mitigation, risk assessment and visualization under typhoon disaster have important scientific significance and engineering value. However, current studies have problems such as incomplete factors, strong subjectivity, complicated calculations, and so on. Therefore, a novel risk assessment and its visualization system consisting of a data layer, knowledge extraction layer, and visualization layer on power towers under typhoon disaster are proposed. On the data layer, a spatial multi-source heterogeneous information database is built based on equipment operation information, meteorological information, and geographic information. On the knowledge extraction layer, six intelligent risk prediction models are established based on machine learning algorithms by hyperparameter optimization. Then the relative optimal model is selected by comparing five evaluation indicators, and the combined model consisting of five relatively superior models is established by goodness of fit method with unequal weight. On the visualization layer, the predicted results are visualized with accuracy of 1   km × 1   km by ArcGIS 10.4. In results, the power tower damage risk assessment is carried out in a Chinese coastal city under the typhoon ‘Mujigae’. By comparing predicted distribution and similarity indicator of the combined model with those of the other models, it is shown that the combined model is superior not only in quality but also in quantity.
Igniting Soaring Droplets of Promising Fuel Slurries
Authors: Bogomolov Alexander , Valiullin Timur , Vershinina Ksenia , Shevyrev Sergey , Shlegel Nikita
Published: January 2019

High rates of environmental pollution by boilers and thermal power plants burning coal of different grades are the main reason for active research in the world aimed at the development of alternative fuels. The solution to the formulated problem acceptable in terms of environmental, technical and economic criteria is the creation of composite slurry fuels with the use of fine coal or coal processing and enrichment waste, water of different quality, and oil sludge additive. This study considers modern technologies of burning slurry fuels as well as perspective research methods of the corresponding processes. A model combustion chamber is developed for the adequate study of ignition processes. The calculation of the basic geometric dimensions is presented. The necessity of manufacturing the combustion chamber in the form of an object of complex geometry is substantiated. With its use, several typical modes of slurry fuel ignition are determined. Principal differences of ignition conditions of a single droplet and group of fuel droplets are shown. Typical vortex structures at the fuel spray injection are shown. A comparison with the trajectories of fuel aerosol droplets in real combustion chambers used for the combustion of slurry fuels is undertaken.
Regulating Reserve Dynamic Scheduling and Optimal Allocation in Systems with a Large Share of Wind-Power Generation
Authors: Srpak Dunja , Havaš Ladislav , Polajžer Boštjan
Published: January 2019

This paper proposes an approach to schedule and allocate regulating reserve in systems with a large share of generation from wind power plants (WPPs). The method for scheduling regulating power is based on the correction of day-ahead schedules planned by the known variations of the load- and wind-power from the previous hour. The correction term incorporates the tendency of changes for previous hours. In this way, more of the regulating power can be reserved during sudden changes in the intensity of the wind. Hence, available existing operational data are required, instead of historical data. The method for allocation of regulating power to regulating units is based on minimization of the transmission losses with optional correction according to economic criteria. The qualitative analysis of the relevant economic features is introduced, as well as the possibilities for applying advanced information and communications technology. The methods discussed were tested for the standard test network RTS 96 and for the Croatian transmission network. Test results showed considerable reduction of the unnecessary positive and negative regulating reserve with increased safety compared to the classic method. Furthermore, optimal allocation of regulating reserve reduced transmission losses for all the cases discussed. Reductions were more significant when the layouts of WPPs and regulating capacities were more geographically dispersed.
Daily Natural Gas Load Forecasting Based on a Hybrid Deep Learning Model
Authors: Wei Nan , Li Changjun , Duan Jiehao , Liu Jinyuan , Zeng Fanhua
Published: January 2019

Forecasting daily natural gas load accurately is difficult because it is affected by various factors. A large number of redundant factors existing in the original dataset will increase computational complexity and decrease the accuracy of forecasting models. This study aims to provide accurate forecasting of natural gas load using a deep learning (DL)-based hybrid model, which combines principal component correlation analysis (PCCA) and (LSTM) network. PCCA is an improved principal component analysis (PCA) and is first proposed here in this paper. Considering the correlation between components in the eigenspace, PCCA can not only extract the components that affect natural gas load but also remove the redundant components. LSTM is a famous DL network, and it was used to predict daily natural gas load in our work. The proposed model was validated by using recent natural gas load data from Xi’an (China) and Athens (Greece). Additionally, 14 weather factors were introduced into the input dataset of the forecasting model. The results showed that PCCA–LSTM demonstrated better performance compared with LSTM, PCA–LSTM, back propagation neural network (BPNN), and support vector regression (SVR). The lowest mean absolute percentage errors of PCCA–LSTM were 3.22% and 7.29% for Xi’an and Athens, respectively. On these bases, the proposed model can be regarded as an accurate and robust model for daily natural gas load forecasting.
Long Term Exposure to Low Ethylene and Storage Temperatures Delays Calyx Senescence and Maintains ‘Afourer’ Mandarins and Navel Oranges Quality
Authors: Alhassan Nasiru , Golding John B. , Wills Ron B. H. , Bowyer Michael C. , Pristijono Penta
Published: January 2019

Calyx browning and internal quality loss are major physiological causes for the loss of quality in citrus fruit during storage. While the symptoms of calyx senescence are only superficial, it can affect the appearance and consumer acceptability of citrus fruit. In this study, continuous ethylene exposure at different storage temperatures was investigated to assess their effect on calyx senescence and internal qualities in ‘Afourer’ mandarin and Navel orange fruit during storage. ‘Afourer’ mandarin fruit were stored at ≤0.001 (equivalent to ethylene-free air), 0.01, 0.1 and 1 µL L−1 of ethylene at either 5, 10 or 20 °C, whilst in a parallel experiment, Navel oranges were exposed to ≤0.001, 0.1 and 1 µL L−1 ethylene at either 1 or 10 °C. Changes in external and internal postharvest quality parameters were assessed for up to 8 weeks for ‘Afourer’ mandarins and 10 weeks for Navel oranges. At all storage temperatures, high levels of ethylene were found to increase the level of calyx senescence, weight loss, loss of fruit firmness and respiration rates. Also, there were significant effects of ethylene and storage temperatures on total soluble solids (TSS) content, titratable acidity (TA), and ethanol accumulation in both citrus species. Continuous exposure to high ethylene also significantly reduced vitamin C and ferric reducing antioxidant power (FRAP) in ‘Afourer’ mandarins after 8 weeks of storage. Overall, ethylene treatments had a significant effect on both the external and internal qualities of the fruit during storage. The relationship between ethylene concentrations and storage temperatures demonstrate that lowering atmospheric ethylene levels at reduced storage temperatures maintain fruit quality during long term storage.
Antihyperuricemia, Antioxidant, and Antibacterial Activities of Tridax procumbens L.
Authors: Andriana Yusuf , Xuan Tran Dang , Quy Tran Ngoc , Minh Truong Ngoc , Van Truong Mai , Viet Tran Duc
Published: January 2019

Tridax procumbens L. is a medicinal plant and used as a drink to treat bronchial catarrh, diarrhea, dysentery and liver diseases. In this study, we evaluated the potential use of T. procumbens to treat hyperuricemia, oxidative stress, and bacterial infection. Ethyl acetate extract of this plant was separated to different fractions by column chromatography (CC) using chloroform and methanol as eluents and subjected to xanthine oxidase (XO) inhibitory, antioxidant, and antibacterial assays. The results showed that the F45–47 fraction exhibited the strongest XO inhibitory activity (IC50 = 133.17 µg/mL), while the F48–50 fraction possessed maximum antioxidant activity assessed by DPPH (2,2-diphenyl-2-picrylhydrazyl) and ABTS (2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assays (IC50 = 0.51 and 1.04 mg/mL, respectively). In addition, the F4–5 fraction presented the most effective inhibition on the growth of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Proteus mirabilis. Gas chromatography-mass spectrophotometry (GS-MS) and liquid chromatography-electrospray ionization-mass spectrophotometry (LC-ESI-MS) results revealed that fatty acids, glycerides, and flavonoids were the major compounds of the F45–47 fraction. Glycerides, triose sugar alcohols, and fatty acids were dominant compounds of the F48–50 fraction, while sterols were principal components of the F4–5 fraction. This study indicated that T. procumbens had potent inhibitory effects on XO inhibitory, antioxidant, and antibacterial activities. These biological activities may be attributed to the presence of fatty acids, flavonoids, and sterols in this plant. It is suggested that T. procumbens can be utilized as a healthy source to develop beverages and foods to treat antihyperuricemia, oxidative stress, and bacterial infection.
Two-Temperature Magnetohydrodynamics Simulations of Propagation of Semi-Relativistic Jets
Authors: Ohmura Takumi , Machida Mami , Nakamura Kenji , Kudoh Yuki , Asahina Yuta , Matsumoto Ryoji
Published: January 2019

In astrophysical jets observed in active galactic nuclei and in microquasars, the energy exchange rate by Coulomb collision is insufficient for thermal equilibrium between ions and electrons. Therefore, it is necessary to consider the difference between the ion temperature and the electron temperature. We present the results of two-temperature magnetohydrodynamics(MHD) simulations to demonstrate the effects of Coulomb coupling. It is assumed that the thermal dissipation heats only ions. We find that the ion and electron temperatures are separated through shocks. Since the ion entropy is increased by energy dissipation at shocks and the Coulomb collisions are inefficient, electron temperature becomes about 10 times lower than the ion temperature in the hotspot ahead of the jet terminal shock. In the cocoon, electron temperature decreases by gas mixing between high temperature cocoon gas and low temperature shocked-ambient gas even when we neglect radiative cooling, but electrons can be heated through collisions with ions. Radiation intensity maps are produced by post processing numerical results. Distributions of the thermal bremsstrahlung radiation computed from electron temperature have bright filament and cavity around the jet terminal shock.
Local Structure of Ca2+ Alginate Hydrogels Gelled via Competitive Ligand Exchange and Measured by Small Angle X-Ray Scattering
Authors: Yamamoto Kyoko , Yuguchi Yoshiaki , Stokke Bjørn Torger , Sikorski Pawel , Bassett David C.
Published: January 2019

Alginates, being linear anionic co-polymers of 1,4-linked residues β-d-ManA (M) and α-l-GulA (G), are widely applied as hydrogel biomaterials due to their favourable in vivo biocompatibility and convenient ionic crosslinking. The “egg-box” model is the prevailing description of the local structure of junction zones that form between the alginate chains and divalent cations, such as Ca2+, when ionic gelation occurs. In the present study we address to what extent signatures of lateral dimerization and further lateral association of junction zones also represent a valid model for the gelation of alginate using the recently reported method of competitive ligand exchange of chelated Ca2+ ions as a method for introducing gelling ions at constant pH. Small angle X-ray scattering with a q range from 0.1 to 3.3 nm−1 was employed to determine local structure in the hydrogel, using a custom-made fluid sample cell inserted in the X-ray beam. The scattering volume was intended to be localized to the contact zone between the two injected aqueous alginate solutions, and data was captured to resolve the kinetics of the structure formation at three different conditions of pH. The data show evolution of the local structure for the Ca2+ induced formation of junction zones in an alginate with 68% G residues, characterized by cross-sectional radii that could be accounted for by a two-component, broken rod like model. The evolution of the two component weight fractions apparently underpinned the connectivity, as reflected in the rheological data.
Using a Chemical Genetic Screen to Enhance Our Understanding of the Antimicrobial Properties of Gallium against Escherichia coli
Authors: Gugala Natalie , Chatfield-Reed Kate , Turner Raymond J. , Chua Gordon
Published: January 2019

The diagnostic and therapeutic agent gallium offers multiple clinical and commercial uses including the treatment of cancer and the localization of tumors, among others. Further, this metal has been proven to be an effective antimicrobial agent against a number of microbes. Despite the latter, the fundamental mechanisms of gallium action have yet to be fully identified and understood. To further the development of this antimicrobial, it is imperative that we understand the mechanisms by which gallium interacts with cells. As a result, we screened the Escherichia coli Keio mutant collection as a means of identifying the genes that are implicated in prolonged gallium toxicity or resistance and mapped their biological processes to their respective cellular system. We discovered that the deletion of genes functioning in response to oxidative stress, DNA or iron–sulfur cluster repair, and nucleotide biosynthesis were sensitive to gallium, while Ga resistance comprised of genes involved in iron/siderophore import, amino acid biosynthesis and cell envelope maintenance. Altogether, our explanations of these findings offer further insight into the mechanisms of gallium toxicity and resistance in E. coli.
Structural Control of a Dissolution Network in a Limestone Reservoir Forced by Radial Injection of CO2 Saturated Solution: Experimental Results Coupled with X-ray Computed Tomography
Authors: Privalov Vitaliy , Randi Aurélien , Sterpenich Jérôme , Pironon Jacques , Morlot Christophe
Published: January 2019

This study was conducted in the framework of the PILOT CO2-DISSOLVED project, which provides an additional approach for CO2 sequestration, with the aims of capturing, injecting, and locally storing the CO2 after being dissolved in brine. The brine acidity is expected to induce chemical reactions with the mineral phase of the host reservoir. A set of continuous radial CO2 flow experiments was performed on cylindrical carbonate rock samples under geological storage conditions. The objective was to interpret the dissolution network morphology and orientation involved. To explore the three-dimensional architecture of dissolution arrays and their connection integrity within core samples, we used computed tomography. A structural investigation at different scales revealed the impact of the rock heterogeneity on the dissolution pathways. The initial strike of the observed mesoscopic wormholes appears to be parallel to dilatational fractures, with a subsequent change in major trends of dissolution along master shears or, more specifically, a combination of synthetic shears and secondary synthetic shears. Antithetic shears organize themselves as slickolitic surfaces, which may be fluid-flow barriers due to different mineralogy, thus affecting the permeability distribution-wormhole growth geometry induced by CO2-rich solutions.
Kriging with a Small Number of Data Points Supported by Jack-Knifing, a Case Study in the Sava Depression (Northern Croatia)
Authors: Malvić Tomislav , Ivšinović Josip , Velić Josipa , Rajić Rajna
Published: January 2019

The semivariogram and the ordinary kriging analyses of porosity data from the Sava Depression (Northern Croatia), are presented relative to the Croatian part of the Pannonian Basin system. The data are taken from hydrocarbon reservoirs of the Lower Pontian (Upper Miocene) age, which belong to the Kloštar Ivanić Formation. The original datasets had been jack-knifed with the purpose of re-sampling and calculating the more reliable semivariograms. The results showed that such improvements can assist in the interpolation of more reliable maps. Both sets, made by the original and re-sampled data, need to be compared using geological recognition of isoline’s shapes (such as “bull-eye” or “butterfly” effects) as well as cross-validation results. This comparison made it possible to select the most appropriate porosity interpolation.
The Evolving Role of Mucosal Histology in the Evaluation of Pediatric Functional Dyspepsia: A Review
Authors: Friesen Craig A. , Colombo Jennifer M. , Schurman Jennifer V.
Published: January 2019

Although not required to establish the diagnosis, endoscopy with mucosal biopsy is commonly performed in the evaluation of children with dyspepsia. Traditionally, esophagogastroduodenoscopy (EGD) has been performed in children with abdominal pain to identify pathology or conversely, to “rule-out” organic disease in order to establish a diagnosis of FD. In this review, we discuss the current diagnostic yield of endoscopically-obtained biopsies in identifying disease in children and adolescents with dyspepsia including an expanded discussion of common histologic diagnoses where clinical significance has not been definitively established. In turn, we discuss the transition of endoscopy from a search for disease to a search for biologic contributors to symptom generation, while considering the growing evidence linking non-diagnostic mucosal inflammation to FD, specifically mast cells and eosinophils.
Archaeologists, Treasure Hunters and Collectors: Heritage in the Spotlight
Authors: Salerno Virginia M. , Mazzia Natalia , González María Isabel , Pérez de Micou Cecilia
Published: January 2019

This paper inquiries into different aspects involved in gathering archaeological materials practices in the contemporary world. Archaeological objects comprise an intricate network of interests such as social, academic, scientific, touristic, historical, territorial, and economic, among others. It is based on those interests that the objects are appropriated and re-signified depending on specific contexts. We introduce two Argentinean cases in order to look into the relations between people and collected objects, and how those relations intertwine with social and political issues. Founded on these cases, we assess the need to create a broad-encompassing framework to study the collecting practices and the great diversity of actors involved.
Self-Efficacy as a Moderator between Stress and Professional Burnout in Firefighters
Authors: Makara-Studzińska Marta , Golonka Krystyna , Izydorczyk Bernadetta
Published: January 2019

The purpose of the study is to analyze the importance of individual resources in firefighting, one of the highest risk professions. Firefighters from 12 different Polish provinces (N = 580; men; M (mean age) = 35.26 year, SD = 6.74) were analyzed regarding the perceived stress at work, burnout, self-efficacy, and a broad range of sociodemographic variables. The Perceived Stress Scale (PSS), the Link Burnout Questionnaire (LBQ), and the General Self-Efficacy Scale (GSES) were used in the study. To explore the relationships between work-related stress, burnout, and self-efficacy, separate regression models for each burnout dimension were analyzed. The results revealed that self-efficacy is a significant moderator that changes the direction and strength of the relationships between perceived stress and psychophysical exhaustion, sense of professional inefficacy, and disillusion. However, self-efficacy did not moderate the relationship between stress and lack of engagement in relationships (relationship deterioration). The results indicate that self-efficacy in firefighters is a crucial personal resource that buffers the impact of perceived stress on most burnout symptoms. It may be concluded that in high risk professions, special attention should be paid to developing self-efficacy as an important part of burnout prevention programs, pro-health activities, and psychoeducation.
Controversies Surrounding Vitamin D: Focus on Supplementation and Cancer
Authors: Minisola Salvatore , Ferrone Federica , Danese Vittoria , Cecchetti Veronica , Pepe Jessica , Cipriani Cristiana , Colangelo Luciano
Published: January 2019

There has recently been a huge number of publications concerning various aspects of vitamin D, from the physiological to therapeutic fields. However, as a consequence of this very fast-growing scientific area, some issues still remain surrounded by uncertainties, without a final agreement having been reached. Examples include the definitions of vitamin D sufficiency and insufficiency, (i.e., 20 vs. 30 ng/mL), the relationship between 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone, (i.e., linear vs. no linear), the referent to consider, (i.e., total vs. free determination), the utility of screening versus universal supplementation, and so on. In this review, the issues related to vitamin D supplementation in subjects with documented hypovitaminosis, and the role of vitamin D in cancer will be concisely considered. Daily, weekly, or monthly administration of cholecalciferol generally leads to essentially similar results in terms of an increase in 25(OH)D serum levels. However, we should also consider possible differences related to a number of variables, (i.e., efficiency of intestinal absorption, binding to vitamin D binding protein, and so on). Thus, adherence to therapy may be more important than the dose regimen chosen in order to allow long-term compliance in a sometimes very old population already swamped by many drugs. It is difficult to draw firm conclusions at present regarding the relationship between cancer and vitamin D. In vitro and preclinical studies seem to have been more convincing than clinical investigations. Positive results in human studies have been mainly derived from post-hoc analyses, secondary end-points or meta-analyses, with the last showing not a decrease in cancer incidence but rather in mortality. We must therefore proceed with a word of caution. Until it has been clearly demonstrated that there is a causal relationship, these positive “non-primary, end-point results” should be considered as a background for generating new hypotheses for future investigations.
Parental Correlates of Outdoor Play in Boys and Girls Aged 0 to 12—A Systematic Review
Authors: Boxberger Karolina , Reimers Anne Kerstin
Published: January 2019

Outdoor play is one major source of physical activity (PA) in children. In particular, parents act as gatekeepers, because they can enable their children’s outdoor play. This systematic review aims to provide an overview of parental correlates of outdoor play. A systematic literature research of six electronic databases (ERIC, PsycARTICLES, PsycINFO, PubMed/Medline, SCOPUS, and Web of Science Core Collection) was conducted with previously defined search terms, focusing on children 0–12 years old. In total, 1719 potentially publications were screened based on eligibility criteria. Included studies were scored for overall study quality. Findings were summarized using a semi-quantitative method. Twenty-one peer-reviewed publications which examined the relationship of parental correlates and outdoor play were included. Overall, five parental correlates were associated with children’s amount of outdoor play: mothers’ ethnicity, mothers’ employment status, parents’ education level, the importance parents assign to outdoor play, and perceived social cohesion in the neighborhood. Merely four studies reported sex/gender-stratified results. In summary, only parents’ encouragement/support provided evidence for girls’ amount of outdoor play. The findings are considered to be of public health relevance for developing intervention programs to increase outdoor play and for improving child’s health. More research, especially considering sex/gender of the child, is required.
Remote Sensing in Environmental Justice Research—A Review
Authors: Weigand Matthias , Wurm Michael , Dech Stefan , Taubenböck Hannes
Published: January 2019

Human health is known to be affected by the physical environment. Various environmental influences have been identified to benefit or challenge people’s physical condition. Their heterogeneous distribution in space results in unequal burdens depending on the place of living. In addition, since societal groups tend to also show patterns of segregation, this leads to unequal exposures depending on social status. In this context, environmental justice research examines how certain social groups are more affected by such exposures. Yet, analyses of this per se spatial phenomenon are oftentimes criticized for using “essentially aspatial” data or methods which neglect local spatial patterns by aggregating environmental conditions over large areas. Recent technological and methodological developments in satellite remote sensing have proven to provide highly detailed information on environmental conditions. This narrative review therefore discusses known influences of the urban environment on human health and presents spatial data and applications for analyzing these influences. Furthermore, it is discussed how geographic data are used in general and in the interdisciplinary research field of environmental justice in particular. These considerations include the modifiable areal unit problem and ecological fallacy. In this review we argue that modern earth observation data can represent an important data source for research on environmental justice and health. Especially due to their high level of spatial detail and the provided large-area coverage, they allow for spatially continuous description of environmental characteristics. As a future perspective, ongoing earth observation missions, as well as processing architectures, ensure data availability and applicability of ’big earth data’ for future environmental justice analyses.
Investigating the Utility Potential of Low-Cost Unmanned Aerial Vehicles in the Temporal Monitoring of a Landfill
Authors: Incekara Abdullah Harun , Delen Ahmet , Seker Dursun Zafer , Goksel Cigdem
Published: January 2019

The collection of solid waste is a challenging issue, especially in highly urbanized areas. In developing countries, landfilling is currently the preferred method for disposing of solid waste, but each landfill has a limited lifecycle. Therefore, changes in the amount of stored waste should be monitored for the sustainable management of such areas. In this study, volumetric changes in a landfill were examined using a low-cost unmanned aerial vehicle (UAV). Aerial photographs obtained from five different flights, covering approximately two years, were used in the volume calculations. Values representing the amount of remaining space between the solid waste and a reference plane were determined using digital elevation models, which were produced based on the structure from motion (SfM) approach. The obtained results and potential of UAVs in the photogrammetric survey of a landfill were further evaluated and interpreted by considering other possible techniques, ongoing progress, and the information existing in an environmental impact assessment report. As a result of the study, it was proved that SfM carried out using a low-cost UAV has a high potential for use in the reconstruction of a landfill. Outcomes were obtained over a short period, without the need for direct contact with the solid waste, making the UAV preferable for use in planning and decision-making studies.
Application of UAV Photogrammetry in Displacement Measurement of the Soil Nail Walls Using Local Features and CPDA Method
Authors: Esmaeili Farid , Ebadi Hamid , Saadatseresht Mohammad , Kalantary Farzin
Published: January 2019

The high cost of land across urban areas has made the excavation a typical practice to construct multiple underground stories. Various methods have been used to restrain the excavated walls and keep them from a possible collapse, including nailing and anchorage. The excavated wall monitoring, especially during the drilling and restraining operations, is necessary for preventing the risk of such incidents as an excavated wall collapse. In the present research, an unmanned aerial vehicle (UAV) photogrammetry-based algorithm was proposed for accurate, fast and low-cost monitoring of excavated walls. Different stages of the proposed methodology included design of the UAV photogrammetry network for optimal imaging, local feature extraction from the acquired images, a special optimal matching method and finally, displacement estimation through a combined adjustment method. Results of implementations showed that, using the proposed methodology, one can achieve a precision of ±7 mm in positioning local features on the excavated walls. Moreover, the wall displacement could be measured at an accuracy of ±1 cm. Having high flexibility, easy implementation, low cost and fast pace; the proposed methodology provides an appropriate alternative to micro-geodesic procedures and the use of instrumentations for excavated wall displacement monitoring.
Differential Immunomodulatory Effect of Graphene Oxide and Vanillin-Functionalized Graphene Oxide Nanoparticles in Human Acute Monocytic Leukemia Cell Line (THP-1)
Authors: Gurunathan Sangiliyandi , Kang Min-Hee , Jeyaraj Muniyandi , Kim Jin-Hoi
Published: January 2019

Graphene and its derivatives are emerging as attractive materials for biomedical applications, including antibacterial, gene delivery, contrast imaging, and anticancer therapy applications. It is of fundamental importance to study the cytotoxicity and biocompatibility of these materials as well as how they interact with the immune system. The present study was conducted to assess the immunotoxicity of graphene oxide (GO) and vanillin-functionalized GO (V-rGO) on THP-1 cells, a human acute monocytic leukemia cell line. The synthesized GO and V-rGO were characterized by using various analytical techniques. Various concentrations of GO and V-rGO showed toxic effects on THP-1 cells such as the loss of cell viability and proliferation in a dose-dependent manner. Cytotoxicity was further demonstrated as an increased level of lactate dehydrogenase (LDH), loss of mitochondrial membrane potential (MMP), decreased level of ATP content, and cell death. Increased levels of reactive oxygen species (ROS) and lipid peroxidation caused redox imbalance in THP-1 cells, leading to increased levels of malondialdehyde (MDA) and decreased levels of anti-oxidants such as glutathione (GSH), glutathione peroxidase (GPX), super oxide dismutase (SOD), and catalase (CAT). Increased generation of ROS and reduced MMP with simultaneous increases in the expression of pro-apoptotic genes and downregulation of anti-apoptotic genes suggest that the mitochondria-mediated pathway is involved in GO and V-rGO-induced apoptosis. Apoptosis was induced consistently with the significant DNA damage caused by increased levels of 8-oxo-dG and upregulation of various key DNA-regulating genes in THP-1 cells, indicating that GO and V-rGO induce cell death through oxidative stress. As a result of these events, GO and V-rGO stimulated the secretion of various cytokines and chemokines, indicating that the graphene materials induced potent inflammatory responses to THP-1 cells. The harshness of V-rGO in all assays tested occurred because of better charge transfer, various carbon to oxygen ratios, and chemical compositions in the rGO. Overall, these findings suggest that it is essential to better understand the parameters governing GO and functionalized GO in immunotoxicity and inflammation. Rational design of safe GO-based formulations for various applications, including nanomedicine, may result in the development of risk management methods for people exposed to graphene and graphene family materials, as these nanoparticles can be used as delivery agents in various biomedical applications.
New Structures and Gating of Voltage-Dependent Potassium (Kv) Channels and Their Relatives: A Multi-Domain and Dynamic Question
Authors: Barros Francisco , Pardo Luis A. , Domínguez Pedro , Sierra Luisa Maria , De la Peña Pilar
Published: January 2019

Voltage-dependent potassium channels (Kv channels) are crucial regulators of cell excitability that participate in a range of physiological and pathophysiological processes. These channels are molecular machines that display a mechanism (known as gating) for opening and closing a gate located in a pore domain (PD). In Kv channels, this mechanism is triggered and controlled by changes in the magnitude of the transmembrane voltage sensed by a voltage-sensing domain (VSD). In this review, we consider several aspects of the VSD–PD coupling in Kv channels, and in some relatives, that share a common general structure characterized by a single square-shaped ion conduction pore in the center, surrounded by four VSDs located at the periphery. We compile some recent advances in the knowledge of their architecture, based in cryo-electron microscopy (cryo-EM) data for high-resolution determination of their structure, plus some new functional data obtained with channel variants in which the covalent continuity between the VSD and PD modules has been interrupted. These advances and new data bring about some reconsiderations about the use of exclusively a classical electromechanical lever model of VSD–PD coupling by some Kv channels, and open a view of the Kv-type channels as allosteric machines in which gating may be dynamically influenced by some long-range interactional/allosteric mechanisms.
Improved In Vitro Test Procedure for Full Assessment of the Cytocompatibility of Degradable Magnesium Based on ISO 10993-5/-12
Authors: Jung Ole , Smeets Ralf , Hartjen Philip , Schnettler Reinhard , Feyerabend Frank , Klein Martin , Wegner Nils , Walther Frank , Stangier Dominic , Henningsen Anders , Rendenbach Carsten , Heiland Max , Barbeck Mike , Kopp Alexander
Published: January 2019

Magnesium (Mg)-based biomaterials are promising candidates for bone and tissue regeneration. Alloying and surface modifications provide effective strategies for optimizing and tailoring their degradation kinetics. Nevertheless, biocompatibility analyses of Mg-based materials are challenging due to its special degradation mechanism with continuous hydrogen release. In this context, the hydrogen release and the related (micro-) milieu conditions pretend to strictly follow in vitro standards based on ISO 10993-5/-12. Thus, special adaptions for the testing of Mg materials are necessary, which have been described in a previous study from our group. Based on these adaptions, further developments of a test procedure allowing rapid and effective in vitro cytocompatibility analyses of Mg-based materials based on ISO 10993-5/-12 are necessary. The following study introduces a new two-step test scheme for rapid and effective testing of Mg. Specimens with different surface characteristics were produced by means of plasma electrolytic oxidation (PEO) using silicate-based and phosphate-based electrolytes. The test samples were evaluated for corrosion behavior, cytocompatibility and their mechanical and osteogenic properties. Thereby, two PEO ceramics could be identified for further in vivo evaluations.
Abiotic Stresses Intervene with ABA Signaling to Induce Destructive Metabolic Pathways Leading to Death: Premature Leaf Senescence in Plants
Authors: Asad Muhammad Asad Ullah , Zakari Shamsu Ado , Zhao Qian , Zhou Lujian , Ye Yu , Cheng Fangmin
Published: January 2019

Abiotic stresses trigger premature leaf senescence by affecting some endogenous factors, which is an important limitation for plant growth and grain yield. Among these endogenous factors that regulate leaf senescence, abscisic acid (ABA) works as a link between the oxidase damage of cellular structure and signal molecules responding to abiotic stress during leaf senescence. Considering the importance of ABA, we collect the latest findings related to ABA biosynthesis, ABA signaling, and its inhibitory effect on chloroplast structure destruction, chlorophyll (Chl) degradation, and photosynthesis reduction. Post-translational changes in leaf senescence end with the exhaustion of nutrients, yellowing of leaves, and death of senescent tissues. In this article, we review the literature on the ABA-inducing leaf senescence mechanism in rice and Arabidopsis starting from ABA synthesis, transport, signaling receptors, and catabolism. We also predict the future outcomes of investigations related to other plants. Before changes in translation occur, ABA signaling that mediates the expression of NYC, bZIP, and WRKY transcription factors (TFs) has been investigated to explain the inducing effect on senescence-associated genes. Various factors related to calcium signaling, reactive oxygen species (ROS) production, and protein degradation are elaborated, and research gaps and potential prospects are presented. Examples of gene mutation conferring the delay or induction of leaf senescence are also described, and they may be helpful in understanding the inhibitory effect of abiotic stresses and effective measures to tolerate, minimize, or resist their inducing effect on leaf senescence.
Continuous Passive Motion Promotes and Maintains Chondrogenesis in Autologous Endothelial Progenitor Cell-Loaded Porous PLGA Scaffolds during Osteochondral Defect Repair in a Rabbit Model
Authors: Wang Hsueh-Chun , Lin Tzu-Hsiang , Chang Nai-Jen , Hsu Horng-Chaung , Yeh Ming-Long
Published: January 2019

Continuous passive motion (CPM) is widely used after total knee replacement. In this study, we investigated the effect of CPM combined with cell-based construct-transplantation in osteochondral tissue engineering. We created osteochondral defects (3 mm in diameter and 3 mm in depth) in the medial femoral condyle of 36 knees and randomized them into three groups: ED (empty defect), EPC/PLGA (endothelial progenitor cells (EPCs) seeded in the poly lactic-co-glycolic acid (PLGA) scaffold), or EPC/PLGA/CPM (EPC/PLGA scaffold complemented with CPM starting one day after transplantation). We investigated the effects of CPM and the EPC/PLGA constructs on tissue restoration in weight-bearing sites by histological observation and micro-computed tomography (micro-CT) evaluation 4 and 12 weeks after implantation. After CPM, the EPC/PLGA construct exhibited early osteochondral regeneration and prevention of subchondral bone overgrowth and cartilage degeneration. CPM did not alter the microenvironment created by the construct; it up-regulated the expression of the extracellular matrix components (glycosaminoglycan and collagen), down-regulated bone formation, and induced the biosynthesis of lubricin, which appeared in the EPC/PLGA/CPM group after 12 weeks. CPM can provide promoting signals during osteochondral tissue engineering and achieve a synergistic effect when combined with EPC/PLGA transplantation, so it should be considered a non-invasive treatment to be adopted in clinical practices.
Interplay among Vaginal Microbiome, Immune Response and Sexually Transmitted Viral Infections
Authors: Torcia Maria Gabriella
Published: January 2019

The vaginal ecosystem is important for women’s health and for a successful reproductive life, and an optimal host-microbial interaction is required for the maintenance of eubiosis. The vaginal microbiota is dominated by Lactobacillus species in the majority of women. Loss of Lactobacillus dominance promotes the colonization by anaerobic bacterial species with an increase in microbial diversity. Vaginal dysbiosis is a very frequent condition which affects the immune homeostasis, inducing a rupture in the epithelial barrier and favoring infection by sexually transmitted pathogens. In this review, we describe the known interactions among immune cells and microbial commensals which govern health or disease status. Particular attention is given to microbiota compositions which, through interplay with immune cells, facilitate the establishment of viral infections, such as Human Immunodeficiency Virus (HIV), Human Papilloma Virus (HPV), Herpes Simplex Virus 2 (HSV2).
Generalized RDP Code Based Concurrent Repair Scheme in Cloud Storage Nodes
Authors: Xie Guojun , Shen Jiquan , Yang Huanhuan
Published: January 2019

With the development and popularization of cloud storage technology, cloud storage has become a main method of data storage. Aiming at the problem of large delay and low availability incurred by multiple invalid nodes in cloud storage, a new type of concurrent nodes repair scheme called Distributed-Cross Repair Solution (DCRS) is proposed. In this scheme, system repair operation is performed in replacement nodes, and all of the replacement nodes cooperatively and crossly repair data to ensure that the data blocks that are required for repairing are only transmitted once within the system. This will solve the system repair bottleneck in the traditional repair scheme and resolve the problem of large internal network throughput and other problems, which can effectively reduce the repair delay of the system. At the same time, the repair trigger mechanism is adopted in order to avoid the repair failure problem caused by the coming of additional damaged nodes during the system reparation, which increases the system’s reliability. The simulation results show that the DCRS has obvious effects in reducing system repair delay and increasing system availability.
Temperature Dependent Growth and Mortality of Agrotis segetum
Authors: Esbjerg Peter , Sigsgaard Lene
Published: January 2019

From 1905 to present, cutworm outbreaks have caused substantial yield losses in North Western (NW) Europe. Early authors pointed to dry summers as the trigger; around 1980, the explanation was improved via modelling of historical data. The number of precipitation days and the July temperature proved to be important, and in experiments, moist soil caused considerable mortality. This information was used in preliminary forecasting with pheromone trap catches as biofix for estimations of occurrence and survival. As more precise information on temperature effects on growth and survival was needed, we performed experiments on growth and mortality effects on egg, all larval instars and pupae. We found clear positive relations between temperatures below 35 °C and development rates of eggs, all larval instars and pupae. Mortality was also affected, and low temperature caused pronounced mortality of young larvae. The severe mortality under cold, moist conditions versus high survival under warm, dry conditions may explain both the lack of relation between captures and injuries and the pronounced fluctuations of cutworm attacks in NW Europe reported from 1905 to present. These variations are likely to increase with the climate change and suggest a reanalysis of data on trap capture and injuries to improve decision support and sustainability in Integrated Pest Management.
Initial Exposure of Wax Foundation to Agrochemicals Causes Negligible Effects on the Growth and Winter Survival of Incipient Honey Bee (Apis mellifera) Colonies
Authors: Payne Alexandria N. , Walsh Elizabeth M. , Rangel Juliana
Published: January 2019

Widespread use of agrochemicals in the U.S. has led to nearly universal contamination of beeswax in honey bee hives. The most commonly found agrochemicals in wax include beekeeper-applied miticides containing tau-fluvalinate, coumaphos, or amitraz, and field-applied pesticides containing chlorothalonil or chlorpyrifos. Wax contaminated with these pesticides negatively affects the reproductive quality of queens and drones. However, the synergistic effects of these pesticides on the growth and survival of incipient colonies remain understudied. We established new colonies using frames with wax foundation that was pesticide free or contaminated with field-relevant concentrations of amitraz alone, a combination of tau-fluvalinate and coumaphos, or a combination of chlorothalonil and chlorpyrifos. Colony growth was assessed by estimating comb and brood production, food storage, and adult bee population during a colony’s first season. We also measured colony overwintering survival. We found no significant differences in colony growth or survivorship between colonies established on pesticide-free vs. pesticide-laden wax foundation. However, colonies that had Varroa destructor levels above 3% in the fall were more likely to die over winter than those with levels below this threshold, indicating that high Varroa infestation in the fall played a more important role than initial pesticide exposure of wax foundation in the winter survival of newly established colonies.