bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Control Strategy for DC-Link Voltage Balance and Reactive Power Equilibrium of a Single-Phase Cascaded H-Bridge Rectifier
Authors: Luo Chengwei , Luo Derong , Huang Shoudao , Wu Gongping , Zhu Hongzhang , He Qianjun
Published: December 2018

The dc-link voltage balance and reactive power equilibrium of the cascaded H-bridge rectifier (CHBR) are the prerequisites for the safe and stable operation of the system. However, the conventional PI (Proportional-Integral) control strategy only puts emphasis on the CHBR dc-link voltage balance without taking into account its reactive power equilibrium under capacitive and inductive working conditions. For this reason, this paper has proposed a novel control strategy for the CHBR that can not only balance dc-link voltage, but also achieve reactive power equilibrium and eliminate the coupling effect between the voltage-balancing controller (VBC) and original system controller (OSC). The control strategy can achieve dc-link voltage balance and the reactive power equilibrium of the CHBR through modifying the active duty cycle by closed loop control, and adjusting the reactive duty cycle relatively according to the modifiable amount of the active duty cycle. Moreover, the strategy can eliminate the coupling effect between the VBC and OSC by the open loop control modification of the active and reactive duty cycle of any H-bridge module in CHBR. Simulations and experiments have shown that the proposed control strategy is feasible and effective in performing the CHBR dc-link voltage balance and reactive power equilibrium under all working conditions and load variations.
China Progress on Renewable Energy Vehicles: Fuel Cells, Hydrogen and Battery Hybrid Vehicles
Authors: Liu Zhixiang , Kendall Kevin , Yan Xieqiang
Published: December 2018

Clean, renewable energy for Chinese cities is a priority in air quality improvement. This paper describes the recent Chinese advances in Polymer Electrolyte Membrane (PEM) hydrogen-fuel-cell-battery vehicles, including buses and trucks. Following the 2016 Chinese government plan for new energy vehicles, bus production in Foshan has now overtaken that in the EU, USA and Japan combined. Hydrogen infrastructure requires much advance to catch up but numbers of filling stations are now increasing rapidly in the large cities. A particular benefit in China is the large number of battery manufacturing companies which fit well into the energy storage plan for hybrid fuel cell buses. The first city to manufacture thousands of PEM-battery hybrid buses is Foshan where the Feichi (Allenbus) company has built a new factory next to a novel fuel cell production line capable of producing 500 MW of fuel cell units per year. Hundreds of these buses are running on local Foshan routes this year, while production of city delivery trucks has also been substantial. Results for energy consumption of these vehicles are presented and fitted to the Coulomb theory previously delineated.
Impacts of Load Profiles on the Optimization of Power Management of a Green Building Employing Fuel Cells
Authors: Wang Fu-Cheng , Lin Kuang-Ming
Published: December 2018

This paper discusses the performance improvement of a green building by optimization procedures and the influences of load characteristics on optimization. The green building is equipped with a self-sustained hybrid power system consisting of solar cells, wind turbines, batteries, proton exchange membrane fuel cell (PEMFC), electrolyzer, and power electronic devices. We develop a simulation model using the Matlab/SimPowerSystemTM and tune the model parameters based on experimental responses, so that we can predict and analyze system responses without conducting extensive experiments. Three performance indexes are then defined to optimize the design of the hybrid system for three typical load profiles: the household, the laboratory, and the office loads. The results indicate that the total system cost was reduced by 38.9%, 40% and 28.6% for the household, laboratory and office loads, respectively, while the system reliability was improved by 4.89%, 24.42% and 5.08%. That is, the component sizes and power management strategies could greatly improve system cost and reliability, while the performance improvement can be greatly influenced by the characteristics of the load profiles. A safety index is applied to evaluate the sustainability of the hybrid power system under extreme weather conditions. We further discuss two methods for improving the system safety: the use of sub-optimal settings or the additional chemical hydride. Adding 20 kg of NaBH4 can provide 63 kWh and increase system safety by 3.33, 2.10, and 2.90 days for the household, laboratory and office loads, respectively. In future, the proposed method can be applied to explore the potential benefits when constructing customized hybrid power systems.
Numerical Simulation Study on the Law of Attenuation of Hydrate Particles in a Gas Transmission Pipeline
Authors: Yongchao Rao , Yi Sun , Shuli Wang , Ru Jia
Published: December 2018

Based on the swirl flow of gas hydrate pipeline safety flow technology, the numerical simulation method is used to study the attenuation law of hydrate particles, which is of great significance for expanding the boundary of safe flow. The results show that the size of the initial swirl number is mainly related to the twist rate and has nothing to do with the Reynolds number; the smaller the twist rate, the greater the Reynolds number, the greater the number of swirling flow in the same position in the pipeline. The concentration has almost no effect on the change of the swirl number; for the non-dimensional swirl number, and the numerical simulation is roughly the same as the results of the paper, the attenuation coefficient beta and ln (Re) has a linear relationship. The no twist tape is six to eight times larger than the volume fraction of the twisted belt, and the smaller the twist tape twist, the smaller the particle deposition is, the higher the initial concentration of the particles in the pipe, and the larger the volume fraction of the hydrate particles deposited by the tube wall.
Numerical Analysis on the Effect of the Tunnel Slope on the Plug-Holing Phenomena
Authors: Kim Ji Tae , Hong Ki-Bae , Ryou Hong Sun
Published: December 2018

Preventing the plug-holing phenomena of a natural ventilation system in a shallow underground tunnel is important for improving the ventilation performance, and the tunnel slope has a significant influence on the smoke flow. In this study, the effect of the tunnel slope on plug-holing in a shallow underground tunnel was analyzed by numerical method. The tunnel slope was increased by 0–8 degrees and the fire source was assumed to be 5 MW, which is equivalent to one sedan vehicle. As a result, the possibility of plug-holing decreased as the tunnel slope increased. However, when the tunnel slope is more than 4°, the fresh air from the entrance of the tunnel and smoke are diluted before reaching the shaft, so the flow temperature passing through the shaft is lowered, and the ventilation performance begins to decrease. In particular, plug-holing does not occur at the tunnel slopes of 6 and 8°, but the ventilation performance is expected to decrease because the temperature of the smoke discharged to the shaft is much lower than the general smoke temperature. Therefore, it is necessary to design the natural ventilation system considering the influence of the tunnel slope.
Analysis of Nonlinear Dynamics of a Quadratic Boost Converter Used for Maximum Power Point Tracking in a Grid-Interlinked PV System
Authors: El Aroudi Abdelali , Al-Numay Mohamed , Garcia Germain , Al Hossani Khalifa , Al Sayari Naji , Cid-Pastor Angel
Published: December 2018

In this paper, the nonlinear dynamics of a PV-fed high-voltage-gain single-switch quadratic boost converter loaded by a grid-interlinked DC-AC inverter is explored in its parameter space. The control of the input port of the converter is designed using a resistive control approach ensuring stability at the slow time-scale. However, time-domain simulations, performed on a full-order circuit-level switched model implemented in PSIM© software, show that at relatively high irradiance levels, the system may exhibit undesired subharmonic instabilities at the fast time-scale. A model of the system is derived, and a closed-form expression is used for locating the subharmonic instability boundary in terms of parameters of different nature. The theoretical results are in remarkable agreement with the numerical simulations and experimental measurements using a laboratory prototype. The modeling method proposed and the results obtained can help in guiding the design of power conditioning converters for solar PV systems, as well as other similar structures for energy conversion systems.
Fuzzy Damage Analysis of the Seismic Response of a Long-Distance Pipeline under a Coupling Multi-Influence Domain
Authors: Zhang Peng , Wang Yihuan , Qin Guojin
Published: December 2018

For a long-distance pipeline, the seismic load is a four-dimensional space-time excitation that simultaneously changes with time and space. In this work, a novel random space-time seismic model is established for a long-distance pipeline, which uses the Clough-Penzien model based on a random process and model of a random field. The response analysis of a long-distance pipeline for multipoint excitation and a buried pressure pipeline are established, while the stress analysis of the buried pressure pipeline is carried out in combination with von Mises theory. In addition, we consider the impact of the site type. The application of the proposed methodology is proved through numerical simulation. A fuzzy damage model and fuzzy safety criteria are established to assess the degree of the structure. The results indicate that a reasonable assessment and design method should consider the coupling multi-influence domain. In particular, evaluation of the structural damage should be done to establish fuzzy damage models and fuzzy safety criteria. The effective measurement of the uncertainty of such parameters forms an important basis for subsequent structural reliability analysis and design.
Data-Based Sensing and Stochastic Analysis of Biodiesel Production Process
Authors: Ahmad Iftikhar , Ayub Ahsan , Ibrahim Uzair , Khattak Mansoor Khan , Kano Manabu
Published: December 2018

Biodiesel production is a field of outstanding prospects due to the renewable nature of its feedstock and little to no overall CO2 emissions to the environment. Data-based soft sensors are used in realizing stable and efficient operation of biodiesel production. However, the conventional data-based soft sensors cannot grasp the effect of process uncertainty on the process outcomes. In this study, a framework of data-based soft sensors was developed using ensemble learning method, i.e., boosting, for prediction of composition, quantity, and quality of product, i.e., fatty acid methyl esters (FAME), in biodiesel production process from vegetable oil. The ensemble learning method was integrated with the polynomial chaos expansion (PCE) method to quantify the effect of uncertainties in process variables on the target outcomes. The proposed modeling framework is highly accurate in prediction of the target outcomes and quantification of the effect of process uncertainty.
A Cluster-Based Baseline Load Calculation Approach for Individual Industrial and Commercial Customer
Authors: Song Tianli , Li Yang , Zhang Xiao-Ping , Li Jianing , Wu Cong , Wu Qike , Wang Beibei
Published: December 2018

Demand response (DR) in the wholesale electricity market provides an economical and efficient way for customers to participate in the trade during the DR event period. There are various methods to measure the performance of a DR program, among which customer baseline load (CBL) is the most important method in this regard. It provides a prediction of counterfactual consumption levels that customer load would have been without a DR program. Actually, it is an expected load profile. Since the calculation of CBL should be fair and simple, the typical methods that are based on the average model and regression model are the two widely used methods. In this paper, a cluster-based approach is proposed considering the multiple power usage patterns of an individual customer throughout the year. It divides loads of a customer into different types of power usage patterns and it implicitly incorporates the impact of weather and holiday into the CBL calculation. As a result, different baseline calculation approaches could be applied to each customer according to the type of his power usage patterns. Finally, several case studies are conducted on the actual utility meter data, through which the effectiveness of the proposed CBL calculation approach is verified.
Transient Temperature Calculation and Multi-Parameter Thermal Protection of Overhead Transmission Lines Based on an Equivalent Thermal Network
Authors: Hu Jian , Xiong Xiaofu , Chen Jing , Wang Wei , Wang Jian
Published: December 2018

The overload degree of a transmission line is represented by currents in traditional overload protection, which cannot reflect its safety condition accurately. The sudden rise in transmission line current may lead to cascading tripping under traditional protection during power flow transfer in a power system. Therefore, timely and accurate analysis of the transient temperature rise of overhead transmission lines, revealing their overload endurance capability under the premise of ensuring safety, and coordination with power system controls can effectively eliminate overloading. This paper presents a transient temperature calculation method for overhead transmission lines based on an equivalent thermal network. This method can fully consider the temperature-dependent characteristics with material properties, convective heat resistance, and radiation heat and can accurately calculate the gradient distribution and response of the conductor cross-section temperature. The validity and accuracy of the proposed calculation method are verified by a test platform. In addition, a multi-parameter thermal protection strategy is proposed on the basis of the abovementioned calculation method. The protection can adequately explore the maximum overload capability of the line, and prevent from unnecessary tripping to avoid the expansion of accidents. Finally, the validity of the proposed protection is verified by the modified 29-bus system.
Contrasting Rhizospheric and Heterotrophic Components of Soil Respiration during Growing and Non-Growing Seasons in a Temperate Deciduous Forest
Authors: Jiao Zhen , Wang Xingchang
Published: December 2018

The contributions of heterotrophic respiration (RH) to total soil respiration (RS) for the non-growing season, growing season, and annual period are 84.8%, 60.7%, and 63.3%, respectively.Few studies have partitioned RS into its rhizospheric (RR) and heterotrophic components throughout the year in northern forest ecosystems. Our objectives were to quantify the contributions of non-growing season and heterotrophic respiration. We conducted a trenching experiment to quantify RR and RH in a temperate deciduous forest in Northeast China over two years using chamber methods. Temperature sensitivities (Q10) for RS and for RH were both much higher in the non-growing season (November to April) than those in the growing season. The Q10 for RS was higher than Q10 for RH in both seasons, indicating a higher temperature sensitivity of roots versus microorganisms. Mean non-growing season RS, RH, and RR for the two years were 94, 79 and 14 g carbon (C) m−2, respectively, which contributed 10.8%, 14.5%, and 4.5% to the corresponding annual fluxes (869, 547 and 321 g C m−2 year−1, respectively). The contributions of RH to RS for the non-growing season, growing season, and annual period were 84.8%, 60.7%, and 63.3%, respectively. Using the same contribution of non-growing season RS to annual RS, to scale growing season measurements, to the annual scale would introduce significant biases on annual RH (−34 g C m−2 yr−1 or −6%) and RR (16 g C m−2 yr−1 or 5%).We concluded that it was important to take non-growing season measurements in terms of accurately partitioning RS components in northern forests.
Occurrence of the Invasive Bark Beetle Phloeosinus aubei on Common Juniper Trees in the Czech Republic
Authors: Fiala Tomáš , Holuša Jaroslav
Published: December 2018

The small cypress bark beetle Phloeosinus aubei is considered an invasive pest in several central European countries, and we have determined its current distribution on common juniper trees (Juniperus communis) in the Czech Republic. The results indicated that P. aubei is widely distributed in the country but is more common in the east than in the west. The beetle was mainly detected on older, damaged trees and on stems with diameters > 3 cm. The apparently widespread and abundant populations of P. aubei could explain infestations of the beetle on Thuja spp. and Juniperus spp. in gardens (three confirmed cases during the last 10 years). We consider P. aubei to be a potential pest on older, naturally occurring J. communis in protected areas where its population density could increase on weakened and damaged trees. We suggest that P. aubei can be monitored via simple inspection of dying and dead J. communis trees in the field.
Interannual and Seasonal Variations in Ecosystem Transpiration and Water Use Efficiency in a Tropical Rainforest
Authors: Aguilos Maricar , Stahl Clément , Burban Benoit , Hérault Bruno , Courtois Elodie , Coste Sabrina , Wagner Fabien , Ziegler Camille , Takagi Kentaro , Bonal Damien
Published: December 2018

Warmer and drier climates over Amazonia have been predicted for the next century with expected changes in regional water and carbon cycles. We examined the impact of interannual and seasonal variations in climate conditions on ecosystem-level evapotranspiration (ET) and water use efficiency (WUE) to determine key climatic drivers and anticipate the response of these ecosystems to climate change. We used daily climate and eddyflux data recorded at the Guyaflux site in French Guiana from 2004 to 2014. ET and WUE exhibited weak interannual variability. The main climatic driver of ET and WUE was global radiation (Rg), but relative extractable water (REW) and soil temperature (Ts) did also contribute. At the seasonal scale, ET and WUE showed a modal pattern driven by Rg, with maximum values for ET in July and August and for WUE at the beginning of the year. By removing radiation effects during water depleted periods, we showed that soil water stress strongly reduced ET. In contrast, drought conditions enhanced radiation-normalized WUE in almost all the years, suggesting that the lack of soil water had a more severe effect on ecosystem evapotranspiration than on photosynthesis. Our results are of major concern for tropical ecosystem modeling because they suggest that under future climate conditions, tropical forest ecosystems will be able to simultaneously adjust CO2 and H2O fluxes. Yet, for tropical forests under future conditions, the direction of change in WUE at the ecosystem scale is hard to predict, since the impact of radiation on WUE is counterbalanced by adjustments to soil water limitations. Developing mechanistic models that fully integrate the processes associated with CO2 and H2O flux control should help researchers understand and simulate future functional adjustments in these ecosystems.
Olive Leaves Extract from Algerian Oleaster (Olea europaea var. sylvestris) on Microbiological Safety and Shelf-life Stability of Raw Halal Minced Beef during Display
Authors: Djenane Djamel , Gómez Diego , Yangüela Javier , Roncalés Pedro , Ariño Agustín
Published: December 2018

Oleaster (wild olive tree) by-products represent a renewable and low-cost source of biopolyphenols. Leaf extracts (sylv.OLE) of Algerian oleaster, locally called a’hachad (Olea europaea subsp. europaea var. sylvestris), were applied at 1 and 5% (v/w) to raw Halal minced beef (HMB) in order to test its safety and shelf-life prolongation during retail/display. The total phenolic compound content in the extract was 198.7 ± 3.6 mg gallic acid equivalent. Ten compounds were identified in the sylv.OLE by High Performance Liquid Chromatography/Diode Array Detector (HPLC/DAD), of which oleuropein was the most abundant (43.25%). Samples treated with 5% sylv.OLE had significantly higher antimicrobial and antioxidant effects than those treated with 1% extract (p < 0.05). The addition of sylv.OLE reduced psychrotrophic counts as well as the level of pathogens (Salmonella enterica ser. Enteritidis and Shiga toxin-producing Escherichia coli O157:H7). A thiobarbituric acid reactive substance (TBARS) value of 2.42 ± 0.11 was reached throughout six days of retail/display in control samples, while the addition of 5% sylv.OLE reduced TBARS value by 58% (p < 0.05). The presence of sylv.OLE at the tested concentrations did not negatively influence the overall acceptability and bitterness of HMB.
On the Connection of Radio and γ-Ray Emission in Blazars
Authors: Boula Stella , Petropoulou Maria , Mastichiadis Apostolos
Published: December 2018

Blazars are a sub-category of radio-loud active galactic nuclei with relativistic jets pointing towards to the observer. They are well-known for their non-thermal variable emission, which practically extends over the whole electromagnetic spectrum. Despite the plethora of multi-wavelength observations, the issue about the origin of the γ -ray and radio emission in blazar jets remains unsettled. Here, we construct a parametric leptonic model for studying the connection between the γ -ray and radio emission in both steady-state and flaring states of blazars. Assuming that relativistic electrons are injected continuously at a fixed distance from the black hole, we numerically study the evolution of their population as it propagates to larger distances while losing energy due to expansion and radiative cooling. In this framework, γ -ray photons are naturally produced at small distances (e.g., 10 − 3 pc) when the electrons are still very energetic, whereas the radio emission is produced at larger distances (e.g., 1 pc), after the electrons have cooled and the emitting region has become optically thin to synchrotron self-absorption due to expansion. We present preliminary results of our numerical investigation for the steady-state jet emission and the predicted time lags between γ -rays and radio during flares.
Theoretical Discourse on Producing High Temporal Yields of Nuclear Excitations in Cosmogenic 26Al with a PW Laser System: The Pathway to an Astrophysical Earthbound Laboratory
Authors: Spohr Klaus Michael , Doria Domenico , Meyer Bradley Stewart
Published: December 2018

The development of the 10 PW laser system at the Extreme Light Infrastructure is a crucial step towards the realization of an astrophysical Earthbound laboratory. The interaction of high-power laser pulses with matter results in ultrashort (fs-ps) pulses of 10s of MeV ions and radiation that can create plasma and induce nuclear reactions therein. Due to the high fluxes of reaction-driving beam pulses, high yields of radioactive target nuclei in their ground and excited states can be provided in situ on short time scales. Cosmogenic 26Al, which is of pronounced astrophysical interest, is a prime candidate for evaluating these new experimental possibilities. We describe how, for a short duration of Δ t ∼ 200   ps , laser-driven protons with energies above E p ∼ 5   MeV can induce the compound nucleus reaction 26Mg(p, n)26Al leading to high and comparable yields of the three lowest-lying states in 26Al including the short-lived, t 1 / 2 = 1.20 ns state at 417 keV. In the aftermath of the reaction, for a short duration of t ∼ ns , the yield ratios between the ground and the two lowest-lying excited states will resemble those present at thermodynamic equilibrium at high temperatures, thus mimicking high 26Al entropies in cold environments. This can be seen as a possible first step towards an investigation of the interplay between those states in plasma environments. Theory suggests an intricate coupling of the ground state 26Alg.s. and the first excited isomer 26mAl via higher-lying excitations such as the J = 3 + state at 417 keV resulting in a dramatic reduction of the effective lifetime of 26Al which will influence the isotope’s abundance in our Galaxy.
Survival of Radioresistant Bacteria on Europa’s Surface after Pulse Ejection of Subsurface Ocean Water
Authors: Pavlov Anatoly , Cheptsov Vladimir , Tsurkov Denis , Lomasov Vladimir , Frolov Dmitry , Vasiliev Gennady
Published: December 2018

We briefly present preliminary results of our study of the radioresistant bacteria in a low temperature and pressure and high-radiation environment and hypothesize the ability of microorganisms to survive extraterrestrial high-radiation environments, such as the icy surface of Jupiter’s moon, Europa. In this study, samples containing a strain of Deinococcus radiodurans VKM B-1422T embedded into a simulated version of Europa’s ice were put under extreme environmental (−130 °C, 0.01 mbar) and radiation conditions using a specially designed experimental vacuum chamber. The samples were irradiated with 5, 10, 50, and 100 kGy doses and subsequently studied for residual viable cells. We estimate the limit of the accumulated dose that viable cells in those conditions could withstand at 50 kGy. Combining our numerical modelling of the accumulated dose in ice with observations of water eruption events on Europa, we hypothesize that in the case of such events, it is possible that putative extraterrestrial organisms might retain viability in a dormant state for up to 10,000 years, and could be sampled and studied by future probe missions.
Seismic Imaging of Seafloor Deformation Induced by Impact from Large Submarine Landslide Blocks, Offshore Oregon
Authors: Lenz Brandi L. , Sawyer Derek E. , Phrampus Benjamin , Davenport Kathy , Long Ashley
Published: December 2018

A series of large blocks from the 44-North Slide, offshore Oregon, impacted the seafloor with sufficient force to induce a broad zone of deformation. In 2017, we acquired a seismic profile from the headwall area to the outer toe of this slide. Previous work identified this slide, but it has not been imaged at high resolution before this survey. A striking surficial feature is a collection of blocks that lie downslope from an amphitheater-shaped headwall. The blocks traveled up to 20-km horizontally and about 1200-m vertically down a 13° slope and now cover an area of ~100 km2. The blocks have rough and angular edges that extend up to 400-m above the surrounding seafloor. Seaward of the blocks, a 10-km zone of sediment is deformed, horizontally shortened by 8%. We interpret the strain field to be a result of the dynamic impact forces of the slide. This suggests a high-mobility failure with tsunamigenic potential. It is unclear what preconditioned and triggered this event, however, earthquake-induced failure is one possibility. Gas hydrate dissociation may have also played a role due to the presence of a bottom-simulating reflector beneath the source area. This study underscores the need to understand the dynamic processes of submarine landslides to more accurately estimate their societal impacts.
Postharvest UV-C Treatment, Followed by Storage in a Continuous Low-Level Ethylene Atmosphere, Maintains the Quality of ‘Kensington Pride’ Mango Fruit Stored at 20 °C
Authors: Pristijono Penta , Golding John B. , Bowyer Michael C.
Published: December 2018

Mature green ‘Kensington Pride’ mangoes (Mangifera indica L.) were treated with a short-term UV-C light at four different intensities (0, 4.0, 8.3 and 11.7 kJ m−2). After treatment, mangoes were stored for 12 d in air (<0.005 μL L−1 ethylene) or 0.1 μL L−1 ethylene at 20 °C and 100% relative humidity (RH). Weight loss, peel colour, firmness, ethylene production, respiration rate, total soluble solids (TSS), titratable acidity (TA), total chlorophyll content, total phenolic content (TPC) and total antioxidant activity were assessed at 3-d intervals. The results showed that UV-C treatment delayed skin degreening, reduced endogenous ethylene production, suppressed respiration rate and lowered chlorophyll content compared to untreated control fruit. Fruit treated with UV-C had significantly higher TPC and total antioxidant activity at the end of the storage period than untreated fruits for both storage atmospheres. In addition, UV-C treated fruits remained significantly firmer than untreated fruits. UV-C treatment significantly affected TSS and TA levels in different ways. Storage of fruits in 0.1 μL L−1 ethylene significantly affected fruit firmness, respiration rate and ethylene production, while other fruit quality parameters were similar to fruit stored in air. These results indicated that UV-C irradiation could be used as an effective and rapid method to extend the postharvest life of mature green mangoes without adversely affecting certain quality attributes in the presence of low-level ethylene during storage.
“Living an Obstacle Course”: A Qualitative Study Examining the Experiences of Caregivers of Children with Rett Syndrome
Authors: Palacios-Ceña Domingo , Famoso-Pérez Pilar , Salom-Moreno Jaime , Carrasco-Garrido Pilar , Pérez-Corrales Jorge , Paras-Bravo Paula , Güeita-Rodriguez Javier
Published: December 2018

Background: Rett syndrome has considerable effects on the quality of life of affected children, impairing everyday activities and potentially impacting the life of both the caregivers and the family. Our aim was to explore the experiences of a group of caregivers of children with Rett syndrome with regards to living and caring for their children. Methods: We conducted a qualitative case study to examine how 31 caregivers of children with Rett syndrome perceived living with their children. Data were collected through in-depth interviews, focus groups, researchers’ field notes and caregivers’ personal documents. A thematic analysis was performed following the Consolidated Criteria for Reporting Qualitative Research (COREQ) guideline. Results: The experience of being a caregiver of a child with Rett syndrome was expressed as being akin to an “obstacle course”, and was described via three main themes: (a) looking for answers, with two subthemes identified, namely ‘the first symptoms’, and ‘the need for a diagnosis’; (b) managing day to day life, with the subthemes ‘applying treatments’, and ‘learning to care’; and (c) money matters. Conclusions: Rett syndrome has a considerable impact on the lives of the caregivers involved. The health-care process and the management of economic resources are some of the aspects highlighted by caregivers. These findings have important implications for the planning of support services, health systems and health policies.
Linking Industrial Hazards and Social Inequalities: Environmental Injustice in Gujarat, India
Authors: Chakraborty Jayajit , Basu Pratyusha
Published: December 2018

Industrial development in India has rarely been studied through the perspective of environmental justice (EJ) such that the association between industrial development and significant economic and social inequalities remains to be examined. Our article addresses this gap by focusing on Gujarat in western India, a leading industrial state that exemplifies the designation of India as an “emerging economy.” We link the geographic concentration of industrial facilities classified as major accident hazard (MAH) units, further subdivided by size (large or medium/small) and ownership (public or private), to the socio-demographic composition of the population at the subdistrict (taluka) level. Generalized estimating equations (GEEs) are used to analyze statistical associations between MAH unit density and explanatory variables related to the economic and social status of the residential population at the subdistrict level. Our results indicate a significant relationship between presence of socially disadvantaged populations (Scheduled Castes and Scheduled Tribes) and density of all types of MAH units, except those associated with the public sector. Higher urbanization and lower home ownership are also found to be strong predictors of MAH unit density. Overall, our article represents an important step towards understanding the complexities of environmental inequalities stemming from Gujarat’s industrial economy.
Supporting New Community-Based Participatory Research Partnerships
Authors: Teufel-Shone Nicolette I. , Schwartz Anna L. , Hardy Lisa J. , De Heer Hendrik D. , Williamson Heather J. , Dunn Dorothy J. , Polingyumptewa Kellen , Chief Carmenlita
Published: December 2018

Marginalized communities have a documented distrust of research grounded in negative portrayals in the academic literature. Yet, trusted partnerships, the foundation for Community-Based Participatory Research (CBPR), require time to build the capacity for joint decision-making, equitable involvement of academically trained and community investigators, and co-learning. Trust can be difficult to develop within the short time between a funding opportunity announcement and application submission. Resources to support community- and academic-based investigators’ time to discuss contexts, concerns, integration of expertise and locally acceptable research designs and data collection are limited. The National Institutes of Health (NIH) funded Center for American Indian Resilience and the Southwest Health Equity Research Collaborative have implemented an internal funding mechanism to support community and academic-based investigators’ travel cost and time to discuss complementary areas of interest and skills and to decide if moving forward with a partnership and a collaborative grant proposal would be beneficial to the community. The rationale and administration of this Community-Campus Partnership Support (CCPS) Program are described and four examples of supported efforts are provided. Centers and training programs frequently fund pilot grants to support junior investigators and/or exploratory research. This CCPS mechanism should be considered as precursor to pilot work, to stimulate partnership building without the pressure of an approaching grant application deadline.
Evaluating the Efficacy of Government Spending on Air Pollution Control: A Case Study from Beijing
Authors: Xie Xiaoyao , Wang Yuhong
Published: December 2018

The reform and opening up of the Chinese economy over the last 40 years has led to rapid economic development. However, with the rapid expansion of the economy, increasingly serious air pollution is apparent. In order to control urban air pollution effectively, Chinese governments at all levels have invested large sums every year. However, it has become a difficult issue which influences public government decisions with respect to how and according to what standard to distribute financial funds so as to improve air quality while saving money at the same time. Taking Beijing as an example, this paper investigates the ten-year change in the annual daily mean of inhalable particulate matter (PM10), sulfur dioxide (SO2), and nitrogen dioxide (NO2) from the year of 2006 to 2015, researches the invested funds in environmental protection in Beijing, and establishes a relationship between the atmospheric indexes of the above three parameters and government-invested funds in environmental protection. According to model analysis, government financial input has an obvious influence on the improvement of air quality. However, during the long period of financial input, the degree of air quality improvement will reduce gradually as time goes by. There exists a direct link between the effectiveness of government financial input to promote air quality and the air quality index, which means when the pollutant standards index is poor (i.e., the corresponding pollutant concentration is higher), the effectiveness will be more apparent. On the contrary, when the index is at a good level, the effectiveness of government financial input is very small. To achieve the best air quality conditions, the government should set the detailed financial input at or over the first-grade standard according to urban air quality standards.
Active Commuting Behaviours from High School to University in Chile: A Retrospective Study
Authors: Parra-Saldías Maribel , Castro-Piñero Jose , Castillo Paredes Antonio , Palma Leal Ximena , Díaz Martínez Ximena , Rodríguez-Rodríguez Fernando
Published: December 2018

Objective: To compare the differences in the modes and distance of the displacements in high school and university stage in the same sample. Methods: A total of 1288 volunteer university students (614 males and 674 females) participated, with an average age of 22.7 ± 5.8 years, belonging to four private and public universities in Chile where a validated self-report questionnaire was applied to the study, which included the modes, travel time, and distance at school and university. Results: The active commuting decreases from school to university when leaving home (males: 39.6% to 34.0%; p = 0.033 and females: 32.9% to 18.5%, p < 0.001), as well as when returning (males: 44.1% to 33.7%; p < 0.001 and females: 38.6% to 17.6%, p < 0.001). Conversely, non-active modes of transport increase, especially in females (go: 67.1% to 81.4%, return: 61.5% to 82.6%), affected by the increase in the use of public transportation in university. It was also defined that at both school and at university, the active commuting decreases the greater the distance travelled. Conclusion: The active modes of commuting decreased between high school and university and the non-active mode of commuting was the most frequent form of mobility to high school and university, observing that the active trips decreased when the distance from the home to high school or university increased. Public and private intervention policies and strategies are required to maintain or increase the modes of active commuting in the university stage for an active life in adulthood.
Exploring Behavior of People with Suicidal Ideation in a Chinese Online Suicidal Community
Authors: Wang Zheng , Yu Guang , Tian Xianyun
Published: December 2018

People with suicidal ideation (PSI) are increasingly using social media to express suicidal feelings. Researchers have found that their internet-based communication may lead to the spread of suicidal ideation, which presents a set of challenges for suicide prevention. To develop effective prevention and intervention strategies that can be efficiently applied in online communities, we need to understand the behavior of PSI in internet-based communities. However, to date there have been no studies that specifically focus on the behavior of PSI in Chinese online communities. A total of 4489 postings in which users explicitly expressed their suicidal ideation were labeled from 560,000 postings in an internet-based suicidal community on Weibo (one of the biggest social media platforms in China) to explore their behavior. The results reveal that PSI are significantly more active than other users in the community. With the use of social network analysis, we also found that the more frequently users communicate with PSI, the more likely that users would become suicidal. In addition, Chinese women may be more likely to be at risk of suicide than men in the community. This study enriches our knowledge of PSI’s behavior in online communities, which may contribute to detecting and assisting PSI on social media.
Co-Amendment of S and Si Alleviates Cu Toxicity in Rice (Oryza Sativa L.) Grown on Cu-Contaminated Paddy Soil
Authors: Lu Zhihong , Yan Xiao , Wei Zongqiang , Wu Jianfu
Published: December 2018

With irrigation using waste water, application of sewage sludge, and development of mine exploration, copper (Cu) contamination in some paddy fields has become increasingly serious. A greenhouse pot experiment was conducted using a factorial design with three sulfur (S) application rates (i.e., 0, 0.013, and 0.026 g S kg−1 soil) and three silicon (Si) application rates (i.e., 0, 0.05, and 0.1 g Si kg−1 soil) to test the effect of co-amendment of S and Si on alleviating Cu contamination in paddy soil. There were significant interaction effects between S and Si on soil Cu speciation and Cu uptake by rice plants (except brown rice). Sulfur addition decreased the content of soil-exchangeable Cu, whereas Si addition decreased the content of soil-reducible Cu, suggesting that co-amendment of S and Si generally reduced Cu availability. Copper was biominimized in the soil-rice plant system and rice root had the greatest Cu concentration (163–285 mg kg−1). Co-amendment of S and Si decreased the translocation of Cu from soil to rice root, possibly due to decreased soil Cu mobility and enhancement of the formation of iron plaque on rice root. Co-amendment of S-Si at a rate of 0.013 (S)–0.1 (Si) g kg−1 soil, respectively, was the optimal among all treatments.
Prevalence of Alcohol and Tobacco Use among Men and Women in Namibia
Authors: He Zhifei , Bishwajit Ghose , Yaya Sanni
Published: December 2018

Namibia is known to have a high prevalence of tobacco smoking and alcohol consumption. Individuals who smoke are more likely to drink, and vice versa. It was reported that the individual rewarding effect of drinking and smoking were reported to be higher than when they are used at the same time. In this study our objective was to examine the individual and combined prevalence of drinking and smoking and investigate their sociodemographic correlates among adolescent and adult men and women in Namibia. This study was based on data from Namibia Demographic and Health Survey (NDHS 2013). Sample population were 14,185 men and women aged between 15 and 64 years. Self-reported tobacco smoking and alcohol consumption patterns were the outcome variables. Data were analysed using complex sampling techniques to account for survey design. Bivariate and multivariate techniques were used to measure the association between drinking and smoking with the sociodemographic factors. The prevalence of alcohol and tobacco use was, respectively, 53.1% (51.5–54.6) and 8.8% (8.1–9.5), and that of both drinking and smoking was 6.9% (6.3–7.6). In the regression analysis, several sociodemographic factors were found to be significantly associated with alcohol and tobacco use including age, area of residence, religion and educational status. Overall, women had higher rates of drinking alcohol; however, men had higher rates of engaging in high risk drinking. Men and women who reported drinking alcohol had, respectively, 2.57 and 4.60 times higher odds of smoking. Findings suggest that the prevalence of drinking was higher than that of smoking, with men having higher prevalence of high risk drinking. Men and women who drink alcohol were more likely to be smokers. The prevalence of both alcohol and tobacco use showed important sociodemographic patterns which need to be taken into consideration in designing prevention and intervention programs. Strategic tobacco control and smoking cessation approaches should pay particular attention to alcohol users.
Applying Integrated Exposure-Response Functions to PM2.5 Pollution in India
Authors: Limaye Vijay S. , Schöpp Wolfgang , Amann Markus
Published: December 2018

Fine particulate matter (PM2.5, diameter ≤2.5 μm) is implicated as the most health-damaging air pollutant. Large cohort studies of chronic exposure to PM2.5 and mortality risk are largely confined to areas with low to moderate ambient PM2.5 concentrations and posit log-linear exposure-response functions. However, levels of PM2.5 in developing countries such as India are typically much higher, causing unknown health effects. Integrated exposure-response functions for high PM2.5 exposures encompassing risk estimates from ambient air, secondhand smoke, and active smoking exposures have been posited. We apply these functions to estimate the future cause-specific mortality risks associated with population-weighted ambient PM2.5 exposures in India in 2030 using Greenhouse Gas-Air Pollution Interactions and Synergies (GAINS) model projections. The loss in statistical life expectancy (SLE) is calculated based on risk estimates and baseline mortality rates. Losses in SLE are aggregated and weighted using national age-adjusted, cause-specific mortality rates. 2030 PM2.5 pollution in India reaches an annual mean of 74 μg/m3, nearly eight times the corresponding World Health Organization air quality guideline. The national average loss in SLE is 32.5 months (95% Confidence Interval (CI): 29.7–35.2, regional range: 8.5–42.0), compared to an average of 53.7 months (95% CI: 46.3–61.1) using methods currently applied in GAINS. Results indicate wide regional variation in health impacts, and these methods may still underestimate the total health burden caused by PM2.5 exposures due to model assumptions on minimum age thresholds of pollution effects and a limited subset of health endpoints analyzed. Application of the revised exposure-response functions suggests that the most polluted areas in India will reap major health benefits only with substantial improvements in air quality.
Selenium Species: Current Status and Potentials in Cancer Prevention and Therapy
Authors: Tan Heng Wee , Mo Hai-Ying , Lau Andy T. Y. , Xu Yan-Ming
Published: December 2018

Selenium (Se) acts as an essential trace element in the human body due to its unique biological functions, particularly in the oxidation-reduction system. Although several clinical trials indicated no significant benefit of Se in preventing cancer, researchers reported that some Se species exhibit superior anticancer properties. Therefore, a reassessment of the status of Se and Se compounds is necessary in order to provide clearer insights into the potentiality of Se in cancer prevention and therapy. In this review, we organize relevant forms of Se species based on the three main categories of Se—inorganic, organic, and Se-containing nanoparticles (SeNPs)—and overview their potential functions and applications in oncology. Here, we specifically focus on the SeNPs as they have tremendous potential in oncology and other fields. In general, to make better use of Se compounds in cancer prevention and therapy, extensive further study is still required to understand the underlying mechanisms of the Se compounds.
Whole-Genome Association Mapping and Genomic Prediction for Iron Concentration in Wheat Grains
Authors: Alomari Dalia Z. , Eggert Kai , Von Wirén Nicolaus , Polley Andreas , Plieske Jörg , Ganal Martin W. , Liu Fang , Pillen Klaus , Röder Marion S.
Published: December 2018

Malnutrition of iron (Fe) affects two billion people worldwide. Therefore, enhancing grain Fe concentration (GFeC) in wheat (Triticum aestivum L.) is an important goal for breeding. Here we study the genetic factors underlying GFeC trait by genome-wide association studies (GWAS) and the prediction abilities using genomic prediction (GP) in a panel of 369 European elite wheat varieties which was genotyped with 15,523 mapped single-nucleotide polymorphism markers (SNP) and a subpanel of 183 genotypes with 44,233 SNP markers. The resulting means of GFeC from three field experiments ranged from 24.42 to 52.42 μg·g−1 with a broad-sense heritability (H2) equaling 0.59 over the years. GWAS revealed 41 and 137 significant SNPs in the whole and subpanel, respectively, including significant marker-trait associations (MTAs) for best linear unbiased estimates (BLUEs) of GFeC on chromosomes 2A, 3B and 5A. Putative candidate genes such as NAC transcription factors and transmembrane proteins were present on chromosome 2A (763,689,738–765,710,113 bp). The GP for a GFeC trait ranged from low to moderate values. The current study reported GWAS of GFeC for the first time in hexaploid wheat varieties. These findings confirm the utility of GWAS and GP to explore the genetic architecture of GFeC for breeding programs aiming at the improvement of wheat grain quality.