bluuebunny/crossref_metadata_2025 huggingface dataset:
Electricity Price and Load Forecasting using Enhanced Convolutional Neural Network and Enhanced Support Vector Regression in Smart Grids
Authors: Zahid Maheen , Ahmed Fahad , Javaid Nadeem , Abbasi Raza Abid , Zainab Kazmi Hafiza Syeda , Javaid Atia , Bilal Muhammad , Akbar Mariam , Ilahi Manzoor
Published: January 2019

Short-Term Electricity Load Forecasting (STELF) through Data Analytics (DA) is an emerging and active research area. Forecasting about electricity load and price provides future trends and patterns of consumption. There is a loss in generation and use of electricity. So, multiple strategies are used to solve the aforementioned problems. Day-ahead electricity price and load forecasting are beneficial for both suppliers and consumers. In this paper, Deep Learning (DL) and data mining techniques are used for electricity load and price forecasting. XG-Boost (XGB), Decision Tree (DT), Recursive Feature Elimination (RFE) and Random Forest (RF) are used for feature selection and feature extraction. Enhanced Convolutional Neural Network (ECNN) and Enhanced Support Vector Regression (ESVR) are used as classifiers. Grid Search (GS) is used for tuning of the parameters of classifiers to increase their performance. The risk of over-fitting is mitigated by adding multiple layers in ECNN. Finally, the proposed models are compared with different benchmark schemes for stability analysis. The performance metrics MSE, RMSE, MAE, and MAPE are used to evaluate the performance of the proposed models. The experimental results show that the proposed models outperformed other benchmark schemes. ECNN performed well with threshold 0.08 for load forecasting. While ESVR performed better with threshold value 0.15 for price forecasting. ECNN achieved almost 2% better accuracy than CNN. Furthermore, ESVR achieved almost 1% better accuracy than the existing scheme (SVR).
Wave Energy Assessment around the Aegadian Islands (Sicily)
Authors: Lo Re Carlo , Manno Giorgio , Ciraolo Giuseppe , Besio Giovanni
Published: January 2019

This paper presents the estimation of the wave energy potential around the Aegadian islands (Italy), carried out on the basis of high resolution wave hindcast. This reanalysis was developed employing Weather Research and Forecast (WRF) and WAVEWATCH III ® models for the modelling of the atmosphere and the waves, respectively. Wave climate has been determined using the above-mentioned 32-year dataset covering the years from 1979 to 2010. To improve the information about wave characteristics regarding spatial details, i.e., increasing wave model resolution, especially in the nearshore region around the islands, a SWAN (Simulating WAves Nearshore) wave propagation model was used. Results obtained through the development of the nearshore analysis detected four energetic hotspots close to the coast of the islands. Near Marettimo island, only one hotspot was detected with a maximum wave energy flux of 9 kW/m, whereas, around Favignana, three hotspots were identified with a maximum wave energy flux of 6.5 kW/m. Such values of available wave energy resource are promising to develop different projects for wave energy converters in specific areas along the coast, in order to improve the energetic independence of Aegadian islands.
Decaying Swirl Flow and Particle Behavior through the Hole Cleaning Device for Horizontal Drilling of Fossil Fuel
Authors: Qu Jingyu , Yan Tie , Sun Xiaofeng , Li Zijian , Li Wei
Published: January 2019

The hole cleaning device is a powerful application which can effectively slow down the deposition of cuttings during drilling. However, in this complicated swirl flow created by the device, the decay of the swirl flow and the particle behavior are not evident yet. In this paper, the decay of the swirl flow and the particle behavior in the swirl flow field are studied by the Eulerian–Eulerian two-fluid model (TFM) coupled with the kinetic theory of granular flows (KTGF), and sliding mesh (SM) technique for simulating the fluid flow. The results show that the swirl intensity decays exponentially along the flow direction under laminar flow conditions. The swirl flow has a longer acting distance at a higher rotational speed, which can effectively slow down the deposition of cutting particles. The initial swirl intensity of swirl flow induced by the blades increases significantly with the increase of blade height and the decrease of the blade angle. The tangential velocity of the cutting particles in the annulus is more significant near the central region, gradually decreases toward the wall in the radial direction, and rapidly decreases to 0 at the wall surface. The decay rate is negatively correlated with the initial swirl intensity. The results presented here may provide a useful reference for the design of the hole cleaning device.
Robust Mixed

H
2

/

H
∞

Controller Design for Energy Routers in Energy Internet
Authors: Hua Haochen , Qin Yuchao , Geng Jianye , Hao Chuantong , Cao Junwei
Published: January 2019

In this paper, a class of mixed H 2 / H ∞ controller is designed for an energy router (ER) within the scenario of an energy Internet (EI). The considered ER is assumed to have access with photovoltaic panels, wind turbine generators, micro-turbines, fuel cells, diesel engine generators, battery energy storage devices, flywheel energy storage devices, loads, and other ERs. Two types of control targets are considered. First, due to the access of large-scale renewable energy sources, the DC bus voltage deviation within the ER system shall be regulated. Second, an optimal energy management strategy shall be achieved, such that the autonomous power supply-demand balance within each ER is achieved with priority and the rational utilization of controllable power generation devices and energy storage devices are realized. When these objectives are considered simultaneously, the control issues with respect to ER is formulated as a mixed robust H 2 / H ∞ control problem with analytical solutions provided. Several numerical examples are given, and the feasibility and effectiveness of the proposed method are demonstrated.
Optimal Deception Strategies in Power System Fortification against Deliberate Attacks
Authors: Jiang Peng , Huang Shengjun , Zhang Tao
Published: January 2019

As a critical infrastructure, the modern electrical network is faced with various types of threats, such as accidental natural disaster attacks and deliberate artificial attacks, thus the power system fortification has attracted great concerns in the community of academic, industry, and military. Nevertheless, the attacker is commonly assumed to be capable of accessing all information in the literature (e.g., network configuration and defensive plan are explicitly provided to the attacker), which might always be the truth since the grid data access permission is usually restricted. In this paper, the information asymmetry between defender and attacker is investigated, leading to an optimal deception strategy problem for power system fortification. Both the proposed deception and traditional protection strategies are formulated as a tri-level mixed-integer linear programming (MILP) problem and solved via two-stage robust optimization (RO) framework and the column-and-constraint generation (CCG) algorithm. Comprehensive case studies on the 6-bus system and IEEE 57-bus system are implemented to reveal the difference between these two strategies and identify the significance of information deception. Numerical results indicate that deception strategy is superior to protection strategy. In addition, detailed discussions on the performance evaluation and convergence analysis are presented as well.
Life Cycle Assessment of Building Renovation Measures–Trade-off between Building Materials and Energy
Authors: Ramírez-Villegas Ricardo , Eriksson Ola , Olofsson Thomas
Published: January 2019

The scope of this study is to assess how different energy efficient renovation strategies affect the environmental impacts of a multi-family house in a Nordic climate within district heating systems. The European Union has set ambitious targets to reduce energy use and greenhouse gas emissions by the year 2030. There is special attention on reducing the life cycle emissions in the buildings sector. However, the focus has often been on new buildings, although existing buildings represent great potential within the building stock in Europe. In this study, four different renovation scenarios were analyzed with the commercially available life cycle assessment software that follows the European Committee for Standardization (CEN) standard. This study covers all life cycle steps from the cradle to the grave for a residential building in Borlänge, Sweden, where renewable energy dominates. The four scenarios included reduced indoor temperature, improved thermal properties of building material components and heat recovery for the ventilation system. One finding is that changing installations gives an environmental impact comparable to renovations that include both ventilation and building facilities. In addition, the life cycle steps that have the greatest environmental impact in all scenarios are the operational energy use and the building and installation processes. Renovation measures had a major impact on energy use due to the cold climate and low solar irradiation in the heating season. An interesting aspect, however, is that the building materials and the construction processes gave a significant amount of environmental impact.
Complete Procedure for the Economic, Financial and Cost-Competitiveness of Photovoltaic Systems with Self-Consumption
Authors: Talavera D. L. , Muñoz-Cerón E. , de la Casa J. , Lozano-Arjona D. , Theristis M. , Pérez-Higueras P. J.
Published: January 2019

Nowadays, the integration of photovoltaic (PV) systems into the grid involves new and competitive ways to realize this. Thus, it is necessary to define procedures that not only include energy calculations but also incorporate economic and funding feasibility features. According to the literature review, there are numerous tools that are available to carry out a profitability analysis of a photovoltaic system. However, certain shortcomings have been identified, either in the definition of the economic and financial scenarios or in the results obtained, as they do not provide all the necessary information, do not use all the most common economic criteria, or in some cases the complexity and training requirements for their correct implementation may discourage their use. Therefore, in this paper a complete procedure that can be used as a preliminary decision tool prior to the design of an in-depth PV self-consumption system is proposed. Realistic input data makes it possible to not only obtain results for common economic and financial feasibility criteria (Net Present Value, Internal Rate of Return, Discounted Pay-Back Time and Net Cash Balance), but it also allow for a cost-competitiveness evaluation based on the Levelised Cost of Electricity (LCOE). The novel concept of the direct cost of PV self-consumed electricity is also introduced.
N-Doped Porous Carbon from Sargassum spp. as Efficient Metal-Free Electrocatalysts for O2 Reduction in Alkaline Fuel Cells
Authors: Pérez-Salcedo K. Y. , Shi Xuan , Kannan Arunachala Mada , Barbosa Romeli , Quintana Patricia , Escobar Beatriz
Published: January 2019

This work reports the synthesis of N-doped porous carbon (NPC) with a high surface area from Sargassum spp. as a low-cost alternative for electrocatalyst production for the oxygen reduction reaction (ORR). Sargassum spp. was activated with potassium hydroxide at different temperatures (700, 750, and 800 °C) and then doped with pyridine (N700, N750, and N800). As a result of the activation process, the 800 °C sample showed a high surface area (2765 m2 g−1) and good onset potential (0.870 V) and current density (4.87 mA cm−2). The ORR performance of the electrocatalysts in terms of their current density was N800 > N750 > N700 > 750 > 800 > 700, while the onset potential decreased in the following order: N800 > 800 > 750 > 700 > N700 > N750. The fuel cell performance of the membrane electrode assembly (MEA) prepared with electrocatalyst synthesized at 750 °C and doped with pyridine was 12.72 mW cm−2, which was close to that from Pt/C MEA on both the anode and cathode (14.42 mW cm−2). These results indicate that NPCs are an alternative to the problem of Sargassum spp. accumulation in the Caribbean due to their high efficiency as electrocatalysts for ORR.
Influence of Stoichiometry on the Two-Phase Flow Behavior of Proton Exchange Membrane Electrolyzers
Authors: Panchenko Olha , Giesenberg Lennard , Borgardt Elena , Zwaygardt Walter , Kardjilov Nikolay , Markötter Henning , Arlt Tobias , Manke Ingo , Müller Martin , Stolten Detlef , Lehnert Werner
Published: January 2019

In order for electrolysis cells to operate optimally, mass transport must be improved. The key initial component for optimal operation is the current collector, which is also essential for mass transport. Water as an educt of the reaction must be evenly distributed by the current collector to the membrane electrode assembly. As products of the reaction, hydrogen and oxygen must also be directed quickly and efficiently through the current collector into the channel and removed from the cell. The second key component is the stoichiometry, which includes the current density and water volume flow rate and represents the ratio between the water supplied and water consumed. This study presents the correlation of the stoichiometry, two-phase flow in the channel and gas fraction in the porous transport layer for the first time. The gas-water ratio in the channel and porous transport layer during cell operation with various stoichiometries was investigated by means of a model in the form of an ex situ cell without electrochemical processes. Bubble formation in the channel was observed using a transparent cell. The gas-water exchange in the porous transport layer was then investigated using neutron radiography.
A Model of Optimal Gas Supply to a Set of Distributed Consumers
Authors: Mikolajková-Alifov Markéta , Pettersson Frank , Björklund-Sänkiaho Margareta , Saxén Henrik
Published: January 2019

A better design of gas supply chains may lead to a more efficient use of locally available resources, cost savings, higher energy efficiency and lower impact on the environment. In optimizing the supply chain of liquefied natural gas (LNG), compressed natural gas (CNG) or biogas for smaller regions, the task is to find the best supplier and the most efficient way to transport the gas to the customers to cover their demands, including the design of pipeline networks, truck transportation and storage systems. The analysis also has to consider supporting facilities, such as gasification units, truck loading lines and CNG tanking and filling stations. In this work a mathematical model of a gas supply chain is developed, where gas may be supplied by pipeline, as compressed gas in containers or as LNG by tank trucks, with the goal to find the solution that corresponds to lowest overall costs. In order to efficiently solve the combinatorial optimization problem, it is linearized and tacked by mixed integer linear programming. The resulting model is flexible and can easily be adapted to tackle local supply chain problems with multiple gas sources and distributed consumers of very different energy demands. The model is illustrated by applying it on a local gas distribution problem in western Finland. The dependence of the optimal supply chain on the conditions is demonstrated by a sensitivity analysis, which reveals how the model can be used to evaluate different aspects of the resulting supply chains.
Process Disturbances in Agricultural Biogas Production—Causes, Mechanisms and Effects on the Biogas Microbiome: A Review
Authors: Theuerl Susanne , Klang Johanna , Prochnow Annette
Published: January 2019

Disturbances of the anaerobic digestion process reduce the economic and environmental performance of biogas systems. A better understanding of the highly complex process is of crucial importance in order to avoid disturbances. This review defines process disturbances as significant changes in the functionality within the microbial community leading to unacceptable and severe decreases in biogas production and requiring an active counteraction to be overcome. The main types of process disturbances in agricultural biogas production are classified as unfavorable process temperatures, fluctuations in the availability of macro- and micronutrients (feedstock variability), overload of the microbial degradation potential, process-related accumulation of inhibiting metabolites such as hydrogen (H2), ammonium/ammonia (NH4+/NH3) or hydrogen sulphide (H2S) and inhibition by other organic and inorganic toxicants. Causes, mechanisms and effects on the biogas microbiome are discussed. The need for a knowledge-based microbiome management to ensure a stable and efficient production of biogas with low susceptibility to disturbances is derived and an outlook on potential future process monitoring and control by means of microbial indicators is provided.
Multi-Dimensional Indexes for the Sustainability Evaluation of an Active Distribution Network
Authors: Sun Chenjun , Mi Zengqiang , Ren Hui , Jing Zhipeng , Lu Jinling , Watts David
Published: January 2019

An active distribution network (ADN) differs from a traditional distribution network in many aspects, one of which is the integration of a large amount of distributed generation (DG), especially intermittent photovoltaics (PVs). The integration of intermittent PVs has both pros and cons for the distribution system. As the platform on which new techniques work and the main body of a greener future energy system, the development of an ADN has to be sustainable, need-oriented, and environmentally friendly, and the traditional technical–economic evaluation method cannot meet the requirements and provide advice in the decision-making process. Based on the concept of sustainable development, we used an ADN with the integration of a large number of distributed PVs (DGPVs) as an example and established a multi-dimensional index system to evaluate the sustainable development level (SDI) of the ADN. The analysis was based on a platform we built with consideration of the investment feasibility of the DGPVs’ investors, state and industrial policies, and their interactions with the distribution system. We first compared the development of DGPVs and the SDI of the ADN as the carrier of DGPVs under different state policies, and second, we compared the SDIs of three city ADNs with different solar resources and demand levels, but under the same state policy. The analysis results showed that different integration levels of DGPVs can be set for a city/area ADN with different solar resources and demand to achieve a comparable SDI, and a comprehensive incentive mechanism could be adopted for the development of DGPVs. In this way, the benefits of different parties can be considered at the same time and finally, the coordination of the sustainable development of multi-parties can be achieved.
Switching Characteristics Optimization of Two-Phase Interleaved Bidirectional DC/DC for Electric Vehicles
Authors: Wang Feng , Luo Yutao , Li Hongluo , Xu Xiaotong
Published: January 2019

In electric vehicles (EVs), bidirectional DC/DC(Bi-DC/DC) is installed between the battery pack and the DC bus to step up the voltage. In the process of mode switching under step signal, the Bi-DC/DC will be affected by a large current inrush which threatens the safety of the circuit. In this paper, a Bi-DC/DC mode switching method based on the optimized Bézier curve is proposed. The Boost and Buck modes can be switched based on the proposed method with fast and non-overshoot switching performance. The experimental results show that the mode switching can be finished in 4 ms without overshoot based on the optimal switching curve.
Investigating the Effect of Urbanization on Weather Using the Weather Research and Forecasting (WRF) Model: A Case of Metro Manila, Philippines
Authors: Oliveros Jervie M. , Vallar Edgar A. , Galvez Maria Cecilia D.
Published: January 2019

The effect of urbanization of Metro Manila, particularly on the amount of sensible heat flux, rainfall and temperature of selected urban and rural areas, was investigated using the Weather Research and Forecasting Version 3.4.1 (WRFV3.4.1) model. National Center for Environmental Prediction - Final (NCEP-FNL) grib1 data from 2000 to 2010 were used as inputs into the model for meteorological data. The Mann–Kendall trend test (M–K test) was utilized to verify the significance of the trends while Sen’s slope estimator was used to quantify the measured trends. Results showed that, on average, the sensible heat flux of Metro Manila is about 1.5 × 108 Jm−2 higher than in selected areas outside Metro Manila. The occurrence of an urban heat island (UHI) effect was detected in Metro Manila by comparing the difference in the minimum and maximum temperatures. For the selected urban and rural areas, the minimum and maximum temperature differences (relative to Metro Manila) are around 0.4 to 2.4 °C and 0.83 to 2.3 °C, respectively. Metro Manila recorded higher 11-year average values of rainfall during the summer season (8% to 64%), rainy season (15% to 305%), and transition season (8% to 232%) when compared with selected areas from 25 to 100 km from Manila. These results show that the sensible heat flux, temperature and rainfall in Metro Manila is affected by Metro Manila’s urbanization.
Impact of Hydrolysis Methods on the Utilization of Agricultural Residues as Nutrient Source for D-lactic Acid Production by Sporolactobacillus inulinus
Authors: Brock Silvia , Kuenz Anja , Prüße Ulf
Published: January 2019

d-lactic acid is a building block for heat resistant polylactic acid, a biobased polymer with a high potential. Nevertheless, an economically efficient industrial process for d-lactic acid production still needs to be implemented. Yeast extract is an expensive nutrient source, which is used to fulfill the complex nutritional requirements in lactic acid fermentations. The substitution of yeast extract by cheap alternative nutrient sources is a challenge in many fermentation processes. In this study, chemical and enzymatic hydrolysis techniques for protein rich agricultural residues and their effectiveness are compared, as well as their impact on the d-lactic acid production of Sporolactobacillus inulinus. An efficient substitution of yeast extract could be achieved by a variety of agricultural residues, hydrolysed with 3M H2SO4, demonstrating the much higher versatility and effectiveness of this method compared to enzymatic methods. In a fed-batch experiment with chemically hydrolyzed rapeseed meal and minimal supplementation, a lactic acid titer of 221 g L−1 and an overall productivity of 1.55 g (L h)−1 (96% yield) were obtained.
On Adaptive Heuristics that Converge to Correlated Equilibrium
Authors: Bhattacharya Ayan
Published: January 2019

I study the path properties of adaptive heuristics that mimic the natural dynamics of play in a game and converge to the set of correlated equilibria. Despite their apparent differences, I show that these heuristics have an abstract representation as a sequence of probability distributions that satisfy a number of common properties. These properties arise due to the topological structure of the set of correlated equilibria. The characterizations that I obtain have useful applications in the study of the convergence of the heuristics.
Numerical Simulations of Jets from Active Galactic Nuclei
Authors: Martí José-María
Published: January 2019

Numerical simulations have been playing a crucial role in the understanding of jets from active galactic nuclei (AGN) since the advent of the first theoretical models for the inflation of giant double radio galaxies by continuous injection in the late 1970s. In the almost four decades of numerical jet research, the complexity and physical detail of simulations, based mainly on a hydrodynamical/magneto-hydrodynamical description of the jet plasma, have been increasing with the pace of the advance in theoretical models, computational tools and numerical methods. The present review summarizes the status of the numerical simulations of jets from AGNs, from the formation region in the neighborhood of the supermassive central black hole up to the impact point well beyond the galactic scales. Special attention is paid to discuss the achievements of present simulations in interpreting the phenomenology of jets as well as their current limitations and challenges.
Dementia and Challenging Behaviors in Gerontological Centers. A Case Report
Authors: Mouriz Romina , Caamaño Ponte José , García Tuñas Laura , Dosil Carlos , Facal David
Published: January 2019

Among the main challenges in geriatric and gerontological centers, we consider, central, the individualized attention to those elderly persons with challenging behaviors, to the extent that it is possible to design preventive strategies that delay cognitive deterioration and minimize consequences of behavior disorders. The first step will be to develop the correct interpretation of symptoms and deficits as a guarantee of a correct diagnosis which, in addition to not always being easy, has to be adapted to the progression of the disease. We present the case of a 68-year-old institutionalized individual, with an initial diagnosis of diffuse Lewy bodies dementia, analyzing his cognitive and behavioral evolution, and the pharmacological and non-pharmacological approach to the case.
Estimation of Ascorbic Acid in Intact Acerola (Malpighia emarginata DC) Fruit by NIRS and Chemometric Analysis
Authors: Moraes Francisca Pereira de , Costa Rosangela Câmara , Morais Camilo de Lelis Medeiros de , Medeiros Fábio Gonçalves Macêdo de , Fernandes Tássia Rayane Nascimento , Hoskin Roberta Targino , Lima Kássio Michell Gomes de
Published: January 2019

Acerola fruit is one of the richest natural sources of ascorbic acid ever known. As a consequence, acerola fruit and its products are demanded worldwide for the production of health supplements and the development of functional products. However, the analytical determination of ascorbic acid is time-consuming and costly. In this study, we show a non-destructive, reliable, and fast method to measure the ascorbic acid content in intact acerola, using near-infrared spectroscopy (NIRS) associated with multivariate calibration methods. Models using variable selection by means of interval partial least squares (iPLS) and a genetic algorithm (GA) were tested. The best model for ascorbic acid content, based on the prediction performance, was the GA-PLS method with second derivative spectral pretreatment, with a root mean square error of cross-validation equal to 22.9 mg/100 g, root mean square error of prediction equal to 46.3 mg/100 g, ratio of prediction to deviation equal to 8.0, determination coefficient for calibration equal to 0.98 and determination coefficient for prediction equal to 0.96. The current methodology, using NIR spectroscopy and chemometrics, is a promising and rapid tool to determine the ascorbic acid content of intact acerola fruit.
Exploring Disparities in Maternal Residential Proximity to Unconventional Gas Development in the Barnett Shale in North Texas
Authors: Ish Jennifer , Symanski Elaine , Whitworth Kristina W.
Published: January 2019

Background: This study explores sociodemographic disparities in residential proximity to unconventional gas development (UGD) among pregnant women. Methods: We conducted a secondary analysis using data from a retrospective birth cohort of 164,658 women with a live birth or fetal death from November 2010 to 2012 in the 24-county area comprising the Barnett Shale play, in North Texas. We considered both individual- and census tract-level indicators of sociodemographic status and computed Indexes of Concentration at the Extremes (ICE) to quantify relative neighborhood-level privilege/disadvantage. We used negative binomial regression to investigate the relation between these variables and the count of active UGD wells within 0.8 km of the home during gestation. We calculated count ratios (CR) and 95% confidence intervals (CI) to describe associations. Results: There were fewer wells located near homes of women of color living in low-income areas compared to non-Hispanic white women living in more privileged neighborhoods (ICE race/ethnicity + income: CR = 0.51, 95% CI = 0.48–0.55). Conclusions: While these results highlight a potential disparity in residential proximity to UGD in the Barnett Shale, they do not provide evidence of an environmental justice (EJ) issue nor negate findings of environmental injustice in other regions.
Hydrochemical Analysis and Fuzzy Logic Method for Evaluation of Groundwater Quality in the North Chengdu Plain, China
Authors: Mohamed Adam Khalifa , Liu Dan , Song Kai , Mohamed Mohamed A. A. , Aldaw Elsiddig , Elubid Basheer A.
Published: January 2019

Groundwater is a major water resource in the North Chengdu Plain, China. The research objective is to determine the quality and suitability of groundwater for drinking purposes within the vicinity of a shallow, unconsolidated aquifer of Quaternary age. In this study, a detailed investigation was conducted to define the hydrochemical characteristics that control the quality of groundwater, based on traditional methods. Considering the uncertainties linked with water resources and the environmental complications, the fuzzy logic method was used in the determination of groundwater quality for more precise findings that support decision-making. To achieve such an objective, sixteen water quality guidelines were used to determine groundwater quality status in six selected wells. The results showed that the groundwater is neutral, very hard, and fresh in nature. Dominating cations and anions are in the order of Ca 2 + > Na + > Mg 2 + > K + and HCO 3 − > SO 4 2 − > Cl − . The Piper trilinear diagram demonstrates that the hydrochemical facies of groundwater are mostly of Ca-HCO 3 type. Statistical analysis denotes a positive correlation between most of the chemical parameters. The study took the results of the fuzzy logic evaluation method into consideration, to classify the samples into five groups according to the Chinese groundwater quality standard (GB/T 14848-93) for their suitability for domestic use. The results demonstrated that the quality of the groundwater samples is within grade II and III, and is suitable for drinking purposes. The comprehensive evaluation of groundwater quality is critical to aid sensitive policy decisions, and the proposed approach can guarantee reliable findings to that effect. The results of this study would also be helpful to future researches related to groundwater quality assessment.
Distribution and Release Characteristics of Phosphorus in a Reservoir in Southwest China
Authors: Wang Yuanming , Li Kefeng , Liang Ruifeng , Han Shiqing , Li Yong
Published: January 2019

Dam construction changes the nutrient transport of a river system. Phosphorus is an important fundamental material in the global biochemical cycle and is always a limiting factor in the primary productivity of reservoirs. Extending the study of phosphorus in reservoirs is necessary given the dam construction in southwest China. Zipingpu Reservoir was chosen as the research site in this study. The form and distribution of phosphorus in the reservoir’s surface sediments and overlying water were analyzed. The results showed that overall, the total phosphorus (TP) content of surface sediments in the Zipingpu Reservoir decreased from the tail to the front of the dam. The TP content ranged from 682.39 to 1609.06 mg/kg, with an average value of 1121.08 mg/kg. The TP content at some sampling points was affected by exogenous input. Inorganic phosphorus (IP) was the main form of phosphorus in surface sediments and had a proportion of 89.38%. Among the forms of IP, the content of Ca-P was larger than that of O-P; Ex-P, Fe-P, and Al-P had the lowest contents. Particulate phosphorus (PP) was the main form of phosphorus in the overlying water of the Zipingpu Reservoir and was strongly affected by hydrodynamic conditions. The content of total dissolved phosphorus (TDP) in the overlying water was relatively low. To further understand the risk of phosphorus release in the surface sediments in the reservoir, the rate and flux of phosphorus exchange at the sediment-overlying water interface were investigated through laboratory experiments. The results showed that both water temperature and pH significantly affected the sediment release rate, but the influence of water temperature was more significant. Acidic and alkaline conditions were conducive to the release of phosphorus from sediment, while a neutral environment was not. The release rate significantly increased with increasing water temperature, and a positive linear relationship was found between these two parameters. The sediment exhibited absorption characteristics when the water temperature was extremely low and exhibited releasing characteristics at a high temperature. These results could provide a theoretical basis for the management and protection of reservoir water environments.
Breast-Feeding Protects Children from Adverse Effects of Environmental Tobacco Smoke
Authors: Moshammer Hanns , Hutter Hans-Peter
Published: January 2019

In a cross-sectional study on 433 schoolchildren (aged 6–9 years) from 9 schools in Austria, we observed associations between housing factors like passive smoking and lung function as well as improved lung function in children who had been breast-fed. The latter findings urged the question of whether the protective effects of breast-feeding act on environmental stressors or if they act independently. Therefore, the effect of passive smoking on lung function was stratified by breast-feeding. The detrimental effects of passive smoking were significant but restricted to the group of 53 children without breast-feeding. Breast-feeding counteracts the effect of environmental stressors on the growing respiratory organs.
Growth Hormone (GH) Therapy During the Transition Period: Should We Think about Early Retesting in Patients with Idiopathic and Isolated GH Deficiency?
Authors: Penta Laura , Cofini Marta , Lucchetti Laura , Zenzeri Letizia , Leonardi Alberto , Lanciotti Lucia , Galeazzi Daniela , Verrotti Alberto , Esposito Susanna
Published: January 2019

To investigate growth hormone (GH) secretion at the transition age, retesting of all subjects who have undergone GH replacement therapy is recommended when linear growth and pubertal development are complete to distinguish between transitional and persistent GH deficiency (GHD). Early retesting of children with idiopathic and isolated GHD (i.e., before the achievement of final height and/or the adult pubertal stage) can avoid possible over-treatment. Here, we report data from our population with idiopathic and isolated GHD to encourage changes in the management and timing of retesting. We recruited 31 patients (19 males) with idiopathic GHD who received recombinant GH (rGH) for at least 2 years. All of the patients were retested at the transition age at least 3 months after rGH discontinuation. Permanent GHD was defined as a GH peak of <19 ng/mL after administration of growth hormone–releasing hormone (GHRH) + arginine as a provocative test. Permanent GHD was confirmed in only five of 31 patients (16.13%). None of these patients presented low serum insulin-like growth factor (IGF)-1 levels (<−2 standard deviation score (SDS)). Only one male patient with an IGF-1 serum level lower than −2 SDS showed a normal GH stimulation response, with a GH peak of 44.99 ng/mL. Few patients with idiopathic and isolated GHD demonstrated persistence of the deficit when retested at the transition age, suggesting that the timing of retesting should be anticipated to avoid overtreatment.
The Urban Heat Island in an Urban Context: A Case Study of Mashhad, Iran
Authors: Naserikia Marzie , Asadi Shamsabadi Elyas , Rafieian Mojtaba , Leal Filho Walter
Published: January 2019

In this study, the spatio-temporal changes of urban heat island (UHI) in a mega city located in a semi-arid region and the relationships with normalized difference vegetation index (NDVI) and normalized difference built-up index (NDBI) are appraised using Landsat TM/OLI images with the help of ENVI and ArcGIS software. The results reveal that the relationships between NDBI, NDVI and land surface temperature (LST) varied by year in the study area and they are not suitable indices to study the land surface temperature in arid and semi-arid regions. The study also highlights the importance of weather conditions when appraising the relationship of these indices with land surface temperature. Overall, it can be concluded that LST in arid and steppe regions is most influenced by barren soil. As a result, built-up areas surrounded by soil or bituminous asphalt experience higher land surface temperatures compared to densely built-up areas. Therefore, apart from setting-up more green areas, an effective way to reduce the intensity of UHI in these regions is to develop the use of cool and smart pavements. The experiences from this paper may be of use to cities, many of which are struggling to adapt to a changing climate.
Social Determinants of Rural Health Workforce Retention: A Scoping Review
Authors: Cosgrave Catherine , Malatzky Christina , Gillespie Judy
Published: January 2019

Residents of rural and remote Australia have poorer health outcomes than their metropolitan counterparts. A major contributor to these health disparities is chronic and severe health workforce shortages outside of metropolitan areas—a global phenomenon. Despite emerging recognition of the important influence of place-based social processes on retention, much of the political attention and research is directed elsewhere. A structured scoping review was undertaken to describe the range of research addressing the influence of place-based social processes on turnover or retention of rural health professionals, to identify current gaps in the literature, and to formulate a guide for future rural health workforce retention research. A systematic search of the literature was performed. In total, 21 articles were included, and a thematic analysis was undertaken. The themes identified were (1) rural familiarity and/or interest, (2) social connection and place integration, (3) community participation and satisfaction, and (4) fulfillment of life aspirations. Findings suggest place-based social processes affect and influence the retention of rural health workforces. However, these processes are not well understood. Thus, research is urgently needed to build robust understandings of the social determinants of rural workforce retention. It is contended that future research needs to identify which place-based social processes are amenable to change.
Comparison between Two Types of Dental Unit Waterlines: How Evaluation of Microbiological Contamination Can Support Risk Containment
Authors: Lizzadro Jessica , Mazzotta Marta , Girolamini Luna , Dormi Ada , Pellati Tiziana , Cristino Sandra
Published: January 2019

Infection risk management in a dental unit waterline (DUWL) involves healthcare personnel and patients and is related to routine exposure to water and aerosols that may contain bacterial species. To improve water safety plans, maintenance, and sanitation procedures, analyses of heterotrophic plate counts (HPCs) at 36 °C, and two other microorganisms frequently associated with biofilms, Pseudomonas aeruginosa and Legionella spp., were performed in order to evaluate differences in microbiological contamination between two types of DUWLs: Type A, provided by a water tank, and Type B, directly connected to municipal water. The data showed that the water supply and water safety plan differentially influenced microbiological contamination: Type A DUWLs were more contaminated than Type B DUWLs for all microbiological parameters tested, with significant changes in the percentage of positive samples and contamination levels that were beyond the limits of standard guidelines. The results obtained show how the storage tank, the absence of anti-retraction valves, and the disinfection procedures performed are the main critical points of Type A DUWLs, which confirms that dental unit management (maintenance/sanitization) is often missed or not correctly applied by stakeholders, with an underestimation of the real risk of infection for patients and operators.
Current Outlook on Autophagy in Human Leukemia: Foe in Cancer Stem Cells and Drug Resistance, Friend in New Therapeutic Interventions
Authors: Rothe Katharina , Porter Vanessa , Jiang Xiaoyan
Published: January 2019

Autophagy is an evolutionarily conserved cellular recycling process in cell homeostasis and stress adaptation. It confers protection and promotes survival in response to metabolic/environmental stress, and is upregulated in response to nutrient deprivation, hypoxia, and chemotherapies. Autophagy is also known to sustain malignant cell growth and contributes to cancer stem cell survival when challenged by cytotoxic and/or targeted therapies, a potential mechanism of disease persistence and drug resistance that has gathered momentum. However, different types of human leukemia utilize autophagy in complex, context-specific manners, and the molecular and cellular mechanisms underlying this process involve multiple protein networks that will be discussed in this review. There is mounting preclinical evidence that targeting autophagy can enhance the efficacy of cancer therapies. Chloroquine and other lysosomal inhibitors have spurred initiation of clinical trials and demonstrated that inhibition of autophagy restores chemosensitivity of anticancer drugs, but with limited autophagy-dependent effects. Intriguingly, several autophagy-specific inhibitors, with better therapeutic indexes and lower toxicity, have been developed. Promising preclinical studies with novel combination approaches as well as potential challenges to effectively eradicate drug-resistant cells, particularly cancer stem cells, in human leukemia are also detailed in this review.
Vasoprotective Functions of High-Density Lipoproteins Relevant to Alzheimer’s Disease Are Partially Conserved in Apolipoprotein B-Depleted Plasma
Authors: Button Emily B. , Gilmour Megan , Cheema Harleen K. , Martin Emma M. , Agbay Andrew , Robert Jérôme , Wellington Cheryl L.
Published: January 2019

High-density lipoproteins (HDL) are known to have vasoprotective functions in peripheral arteries and many of these functions extend to brain-derived endothelial cells. Importantly, several novel brain-relevant HDL functions have been discovered using brain endothelial cells and in 3D bioengineered human arteries. The cerebrovascular benefits of HDL in healthy humans may partly explain epidemiological evidence suggesting a protective association of circulating HDL levels against Alzheimer’s Disease (AD) risk. As several methods exist to prepare HDL from plasma, here we compared cerebrovascular functions relevant to AD using HDL isolated by density gradient ultracentrifugation relative to apoB-depleted plasma prepared by polyethylene-glycol precipitation, a common high-throughput method to evaluate HDL cholesterol efflux capacity in clinical biospecimens. We found that apoB-depleted plasma was functionally equivalent to HDL isolated by ultracentrifugation in terms of its ability to reduce vascular Aβ accumulation, suppress TNFα-induced vascular inflammation and delay Aβ fibrillization. However, only HDL isolated by ultracentrifugation was able to suppress Aβ-induced vascular inflammation, improve Aβ clearance, and induce endothelial nitric oxide production.
Carbonic Anhydrase Inhibitors of Different Structures Dilate Pre-Contracted Porcine Retinal Arteries
Authors: Eysteinsson Thor , Gudmundsdottir Hrönn , Hardarson Arnar Oessur , Berrino Emanuela , Selleri Silvia , Supuran Claudiu T. , Carta Fabrizio
Published: January 2019

Carbonic anhydrase inhibitors (CAIs), such as dorzolamide (DZA), are used as anti-glaucoma drugs to lower intraocular pressure, but it has been found that some of these drugs act as vasodilators of retinal arteries. The exact mechanism behind the vasodilatory effect is not yet clear. Here we have addressed the issue by using small vessel myography to examine the effect of CAIs of the sulfonamide and coumarin type on the wall tension in isolated segments of porcine retinal arteries. Vessels were pre-contracted by the prostaglandin analog U-46619, and CAIs with varying affinity for five different carbonic anhydrase (CA) isoenzymes found in human tissue tested. We found that all compounds tested cause a vasodilation of pre-contracted retinal arteries, but with varying efficacy, as indicated by the calculated mean EC50 of each compound, ranging from 4.12 µM to 0.86 mM. All compounds had a lower mean EC50 compared to DZA. The dilation induced by benzolamide (BZA) and DZA was additive, suggesting that they may act on separate mechanisms. No clear pattern in efficacy and affinity for CA isoenzymes could be discerned from the results, although Compound 5, with a low affinity for all isoenzymes except the human (h) CA isoform IV, had the greatest potency, with the lowest EC50 and inducing the most rapid and profound dilation of the vessels. The results suggest that more than one isozyme of CA is involved in mediating its role in controlling vascular tone in retinal arteries, with a probable crucial role played by the membrane-bound isoform CA IV.
Identification of Premeiotic, Meiotic, and Postmeiotic Cells in Testicular Biopsies Without Sperm from Sertoli Cell-Only Syndrome Patients
Authors: Abofoul-Azab Maram , Lunenfeld Eitan , Levitas Eliahu , Zeadna Atif , Younis Johnny , Bar-Ami Shalom , Huleihel Mahmoud
Published: January 2019

Sertoli cell-only syndrome (SCOS) affects about 26.3–57.8% of azoospermic men, with their seminiferous tubules containing only Sertoli cells. Recently, it was reported that testicular biopsies from nonobstructive azoospermic (NOA) patients contained germ cells, and that sperm could be found in the tubules of 20% of SCOS patients using testicular sperm extraction technology. Since the patients without sperm in their testicular biopsies do not have therapy to help them to father a biological child, in vitro maturation of spermatogonial stem cells (SSCs) isolated from their testis is a new approach for possible future infertility treatment. Recently, the induction of human and mice SSCs proliferation and differentiation was demonstrated using different culture systems. Our group reported the induction of spermatogonial cell proliferation and differentiation to meiotic and postmeiotic stages in mice, rhesus monkeys, and prepubertal boys with cancer using 3D agar and methylcellulose (MCS) culture systems. The aim of the study was to identify the type of spermatogenic cells present in biopsies without sperm from SCOS patients, and to examine the possibility of inducing spermatogenesis from isolated spermatogonial cells of these biopsies in vitro using 3D MCS. We used nine biopsies without sperm from SCOS patients, and the presence of spermatogenic markers was evaluated by PCR and specific immunofluorescence staining analyses. Isolated testicular cells were cultured in MCS in the presence of StemPro enriched media with different growth factors and the development of colonies/clusters was examined microscopically. We examined the presence of cells from the different stages of spermatogenesis before and after culture in MCS for 3–7 weeks. Our results indicated that these biopsies showed the presence of premeiotic markers (two to seven markers/biopsy), meiotic markers (of nine biopsies, cAMP responsive element modulator-1 (CREM-1) was detected in five, lactate dehydrogenase (LDH) in five, and BOULE in three) and postmeiotic markers (protamine was detected in six biopsies and acrosin in three). In addition, we were able to induce the development of meiotic and/or postmeiotic stages from spermatogonial cells isolated from three biopsies. Thus, our study shows for the first time the presence of meiotic and/or postmeiotic cells in biopsies without the sperm of SCOS patients. Isolated cells from some of these biopsies could be induced to meiotic and/or postmeiotic stages under in vitro culture conditions.