bluuebunny/crossref_metadata_2025 huggingface dataset:
Mysterious Circle Numbers. Does πp,q Approach πp When q Is Tending to p?
Authors: Richter Wolf-Dieter , Wenzel Vincent
Published: September 2019

This paper aims to introduce a mathematical-philosophical type of question from the fascinating world of generalized circle numbers to the widest possible readership. We start with recalling well-known (in part from school) properties of the polygonal approximation of the common circle when approximating the famous circle number π by convergent sequences of upper and lower bounds being based upon the lengths of polygons. Next, we shortly refer to some results from the literature where suitably defined generalized circle numbers of l p - and l p , q -circles, π p and π p , q , respectively, are considered and turn afterwards over to the approximation of an l p -circle by a family of l p , q -circles with q converging to p, q → p . Then we ask whether or not there holds the continuity property π p , q → π p as q → p . The answer to this question leads us to the answer of the question stated in the paper’s title. Presenting here for illustration true paintings instead of strong technical or mathematical drawings intends both to stimulate opening heart and senses of the reader for recognizing generalized circles in his real life and to suggest the philosophical challenge of the consequences coming out from the demonstrated non-continuity property.
Predictors of Obesity among Gut Microbiota Biomarkers in African American Men with and without Diabetes
Authors: Barengolts Elena , Green Stefan J. , Chlipala George E. , Layden Brian T. , Eisenberg Yuval , Priyadarshini Medha , Dugas Lara R.
Published: September 2019

Gut microbiota and their biomarkers may be associated with obesity. This study evaluated associations of body mass index (BMI) with circulating microbiota biomarkers in African American men (AAM) (n = 75). The main outcomes included fecal microbial community structure (16S rRNA), gut permeability biomarkers (ELISA), and short-chain fatty acids (SCFAs, metabolome analysis). These outcomes were compared between obese and non-obese men, after adjusting for age. The results showed that lipopolysaccharide-binding protein (LBP), the ratio of LBP to CD14 (LBP/CD14), and SCFAs (propionic, butyric, isovaleric) were higher in obese (n = 41, age 58 years, BMI 36 kg/m2) versus non-obese (n = 34, age 55 years, BMI 26 kg/m2) men. BMI correlated positively with LBP, LBP/CD14 (p < 0.05 for both) and SCFAs (propionic, butyric, isovaleric, p < 0.01 for all). In the regression analysis, LBP, LBP/CD14, propionic and butyric acids were independent determinants of BMI. The study showed for the first time that selected microbiota biomarkers (LBP, LBP/CD14, propionic and butyric acids) together with several other relevant risks explained 39%–47% of BMI variability, emphasizing that factors other than microbiota-related biomarkers could be important. Further research is needed to provide clinical and mechanistic insight into microbiota biomarkers and their utility for diagnostic and therapeutic purposes.
Metagenomic Evaluation of Bacterial and Fungal Assemblages Enriched within Diffusion Chambers and Microbial Traps Containing Uraniferous Soils
Authors: Jaswal Rajneesh , Pathak Ashish , Chauhan Ashvini
Published: September 2019

Despite significant technological advancements in the field of microbial ecology, cultivation and subsequent isolation of the vast majority of environmental microorganisms continues to pose challenges. Isolation of the environmental microbiomes is prerequisite to better understand a myriad of ecosystem services they provide, such as bioremediation of contaminants. Towards this end, in this culturomics study, we evaluated the colonization of soil bacterial and fungal communities within diffusion chambers (DC) and microbial traps (MT) established using uraniferous soils collected from a historically contaminated soil from Aiken, USA. Microbial assemblages were compared between the DC and MT relative to the native soils using amplicon based metagenomic and bioinformatic analysis. The overall rationale of this study is that DC and MT growth chambers provide the optimum conditions under which desired microbiota, identified in a previous study to serve as the “core” microbiomes, will proliferate, leading to their successful isolation. Specifically, the core microbiomes consisted of assemblages of bacteria (Burkholderia spp.) and fungi (Penicillium spp.), respectively. The findings from this study further supported previous data such that the abundance and diversity of the desired “core” microbiomes significantly increased as a function of enrichments over three consecutive generations of DC and MT, respectively. Metagenomic analysis of the DC/MT generations also revealed that enrichment and stable populations of the desired “core” bacterial and fungal microbiomes develop within the first 20 days of incubation and the practice of subsequent transfers for second and third generations, as is standard in previous studies, may be unnecessary. As a cost and time cutting measure, this study recommends running the DC/MT chambers for only a 20-day time period, as opposed to previous studies, which were run for months. In summation, it was concluded that, using the diffusion chamber-based enrichment techniques, growth of desired microbiota possessing environmentally relevant functions can be achieved in a much shorter time frame than has been previously shown.
What Is Known About the Nutritional Intake of Women during Pregnancy Following Bariatric Surgery? A Scoping Review
Authors: Maslin Kate , James Alison , Brown Anne , Bogaerts Annick , Shawe Jill
Published: September 2019

Optimising the diet and weight of women prior to and during pregnancy is of paramount importance to both maternal and offspring health. In women who become pregnant after bariatric surgery, evidence suggests a better overall obstetric outcome in comparison to women with severe obesity managed conservatively. Historically, most studies in this population group have monitored supplement adherence or serum concentrations of micronutrients, rather than dietary intake. The aim of this study was to synthesise current knowledge of the dietary intake of women during pregnancy following bariatric surgery. A systematic search of search engines was conducted using the following databases: MEDLINE, Embase, CINAHL, Cochrane database, Scopus, Trip, NHS Evidence, UK Clinical Trials, ClinicalTrials.gov, Prospero, Epistemonikos and Open Grey. Titles and abstracts were screened independently by two reviewers against predefined inclusion and exclusion criteria. After removal of duplicates, 1594 titles were identified, of which 1586 were initially excluded. Following full-text review, four articles were included. In total, across all four studies, data from only 202 bariatric surgery participants were included, the majority of whom had had one type of surgery. Just one study included a control group. Reporting of nutritional outcomes was heterogenous, with none of the studies including complete macro and micronutrient intake results in their articles. An insufficient intake of protein was noted as a concern in two studies and associated with poor fetal growth in one study. Overall, this review has identified a paucity of data about the dietary intake of women during pregnancy after bariatric surgery.
Caffeine Supplementation Improves Anaerobic Performance and Neuromuscular Efficiency and Fatigue in Olympic-Level Boxers
Authors: San Juan Alejandro F. , López-Samanes Álvaro , Jodra Pablo , Valenzuela Pedro L. , Rueda Javier , Veiga-Herreros Pablo , Pérez-López Alberto , Domínguez Raúl
Published: September 2019

Background: this study examined the effects of caffeine supplementation on anaerobic performance, neuromuscular efficiency and upper and lower extremities fatigue in Olympic-level boxers. Methods: Eight male athletes, members of the Spanish National Olympic Team, were enrolled in the study. In a randomized double-blind, placebo-controlled, counterbalanced, crossover design, the athletes completed 2 test sessions after the intake of caffeine (6 mg·kg−1) or placebo. Sessions involved initial measures of lactate, handgrip and countermovement jump (CMJ) performance, followed by a 30-seconds Wingate test, and then final measures of the previous variables. During the sessions, electromiography (EMG) data were recorded on the gluteus maximus, biceps femoris, vastus lateralis, gastrocnemius lateral head and tibialis anterior. Results: caffeine enhanced peak power (6.27%, p < 0.01; Effect Size (ES) = 1.26), mean power (5.21%; p < 0.01; ES = 1.29) and reduced the time needed to reach peak power (−9.91%, p < 0.01; ES = 0.58) in the Wingate test, improved jump height in the CMJ (+2.4 cm, p < 0.01), and improved neuromuscular efficiency at peak power in the vastus lateralis (ES = 1.01) and gluteus maximus (ES = 0.89), and mean power in the vastus lateralis (ES = 0.95) and tibialis anterior (ES = 0.83). Conclusions: in these Olympic-level boxers, caffeine supplementation improved anaerobic performance without affecting EMG activity and fatigue levels in the lower limbs. Further benefits observed were enhanced neuromuscular efficiency in some muscles and improved reaction speed.
Distribution and Community Assembly of Trees Along an Andean Elevational Gradient
Authors: Worthy Samantha J. , Jiménez Paz Rosa A. , Pérez Álvaro J. , Reynolds Alex , Cruse-Sanders Jennifer , Valencia Renato , Barone John A. , Burgess Kevin S.
Published: September 2019

Highlighting patterns of distribution and assembly of plants involves the use of community phylogenetic analyses and complementary traditional taxonomic metrics. However, these patterns are often unknown or in dispute, particularly along elevational gradients, with studies finding different patterns based on elevation. We investigated how patterns of tree diversity and structure change along an elevation gradient using taxonomic and phylogenetic diversity metrics. We sampled 595 individuals (36 families; 53 genera; 88 species) across 15 plots along an elevational gradient (2440–3330 m) in Ecuador. Seventy species were sequenced for the rbcL and matK gene regions to generate a phylogeny. Species richness, Shannon–Weaver diversity, Simpson’s Dominance, Simpson’s Evenness, phylogenetic diversity (PD), mean pairwise distance (MPD), and mean nearest taxon distance (MNTD) were evaluated for each plot. Values were correlated with elevation and standardized effect sizes (SES) of MPD and MNTD were generated, including and excluding tree fern species, for comparisons across elevation. Taxonomic and phylogenetic metrics found that species diversity decreases with elevation. We also found that overall the community has a non-random phylogenetic structure, dependent on the presence of tree ferns, with stronger phylogenetic clustering at high elevations. Combined, this evidence supports the ideas that tree ferns have converged with angiosperms to occupy the same habitat and that an increased filtering of clades has led to more closely related angiosperm species at higher elevations.
Hydrogen Peroxide and Superoxide Anion Radical Photoproduction in PSII Preparations at Various Modifications of the Water-Oxidizing Complex
Authors: Khorobrykh Andrey
Published: September 2019

The photoproduction of superoxide anion radical (O2−•) and hydrogen peroxide (H2O2) in photosystem II (PSII) preparations depending on the damage to the water-oxidizing complex (WOC) was investigated. The light-induced formation of O2−• and H2O2 in the PSII preparations rose with the increased destruction of the WOC. The photoproduction of superoxide both in the PSII preparations holding intact WOC and the samples with damage to the WOC was approximately two times higher than H2O2. The rise of O2−• and H2O2 photoproduction in the PSII preparations in the course of the disassembly of the WOC correlated with the increase in the fraction of the low-potential (LP) Cyt b559. The restoration of electron flow in the Mn-depleted PSII preparations by exogenous electron donors (diphenylcarbazide, Mn2+) suppressed the light-induced formation of O2−• and H2O2. The decrease of O2−• and H2O2 photoproduction upon the restoration of electron transport in the Mn-depleted PSII preparations could be due to the re-conversion of the LP Cyt b559 into higher potential forms. It is supposed that the conversion of the high potential Cyt b559 into its LP form upon damage to the WOC leads to the increase of photoproduction of O2−• and H2O2 in PSII.
Study of 4,4‘-Methylene Diisocyanate Phenyl Ester-Modified Cassava Residues/Polybutylene Succinate Biodegradable Composites: Preparation and Performance Research
Authors: Huang Lijie , Zhao Hanyu , Xu Hao , An Shuxiang , Li Chunying , Huang Chongxing , Wang Shuangfei , Liu Yang , Chen Jie
Published: September 2019

Biomass materials have become a research focus for humankind, due to the decreasing availability of fossil fuels and the increasing release of greenhouse gas. In this work, we prepared biodegradable composites with waste cassava residues and polybutylene succinate (PBS) by modifying cassava residues using 4,4’-methylene diisocyanate phenyl ester (MDI) and tested their properties. The effects of MDI modification on the structure, mechanical properties, water absorption, microstructure, and thermal stability of the composites were studied via Fourier transform infrared spectroscopy, contact angle measurement, mechanical property testing, water absorption analysis, scanning electron microscopy, and thermogravimetric analysis, respectively. The results showed that the tensile strength and flexural strength of the material increased by 72% and 20.89%, respectively, when the MDI-modified cassava residue content was 30%. When 10% MDI-modified cassava residues were added, the tensile strength increased by 19.46% from 16.96 MPa to 20.26 MPa, while the bending strength did not change significantly. The water contact angle of the MDI-treated cassava residues exceeded 100°, indicating excellent hydrophobicity. Thus, MDI modification can significantly improve the mechanical properties and thermal stability of the biocomposite. The composites were immersed in distilled water for 96 h. The water absorption of the cassava residues/PBS composite was 2.19%, while that of the MDI-modified cassava residues/PBS composite was 1.6%; hence, the water absorption of the MDI-modified cassava residues/PBS composite was reduced to 26.94%. This technology has wide application potential in packaging, construction, and allied fields.
Adsorption of Arsenic and Lead onto Stone Powder and Chitosan-Coated Stone Powder
Authors: Jung Kyungho , Oh Sanghwa , Bak Hun , Song Gun-Ho , Kim Hong-Tae
Published: September 2019

Stone powder (SP) produced from masonry mills has been treated as a specific waste and rarely used for environmental purposes. In this study, we tested its potential as an adsorbent to remove arsenic (As) and lead (Pb) from water. The single-solute sorption isotherms for As(V) and Pb(II) onto SP and chitosan-coated SP (CSP) were investigated. Several sorption models, such as the Langmuir, Freundlich, and Dubinin–Radushkevich (DR) models, were used to analyze the adsorption features. The results demonstrated that As and Pb were successfully adsorbed onto SP and CSP, indicating that SP and CSP had potential as adsorbents of As and Pb. The maximum adsorption capacities of SP and CSP for Pb were 22.8 and 54.5 times higher than those for As, respectively. Chitosan coating increased the adsorption potential in Pb adsorption by 5% but decreased it in As adsorption. The adsorption potential also depended on the pH and temperature. The adsorption amount of As increased with pH but that of Pb decreased as pH increased. In addition, the ln b in the Langmuir model increased with 1/T (K), indicating that the adsorption of As and Pb occurred exothermically and spontaneously.
Design and Implementation of a Quadruped Amphibious Robot Using Duck Feet
Authors: Kashem Saad Bin Abul , Jawed Shariq , Ahmed Jubaer , Qidwai Uvais
Published: September 2019

Roaming complexity in terrains and unexpected environments pose significant difficulties in robotic exploration of an area. In a broader sense, robots have to face two common tasks during exploration, namely, walking on the drylands and swimming through the water. This research aims to design and develop an amphibious robot, which incorporates a webbed duck feet design to walk on different terrains, swim in the water, and tackle obstructions on its way. The designed robot is compact, easy to use, and also has the abilities to work autonomously. Such a mechanism is implemented by designing a novel robotic webbed foot consisting of two hinged plates. Because of the design, the webbed feet are able to open and close with the help of water pressure. Klann linkages have been used to convert rotational motion to walking and swimming for the animal’s gait. Because of its amphibian nature, the designed robot can be used for exploring tight caves, closed spaces, and moving on uneven challenging terrains such as sand, mud, or water. It is envisaged that the proposed design will be appreciated in the industry to design amphibious robots in the near future.
Dynamic Cone Penetrometer Incorporated with Time Domain Reflectometry (TDR) Sensors for the Evaluation of Water Contents in Sandy Soils
Authors: Hong Won-Taek , Yu Jung-Doung , Kim Sang Yeob , Lee Jong-Sub
Published: September 2019

Ground moisture content and strength properties are the most important factors for a proper assessment of ground stability. This study developed a dynamic cone penetrometer incorporated with time domain reflectometry (TDR) sensors (TDCP). The TDCP is composed of an anvil, a driving rod, and a TDCP probe. Three wave guides and a K-type thermocouple are installed on the TDCP probe. For utilization of TDCP, relationships between relative permittivities measured by TDCP and those measured by standard TDR probe, temperature, and volumetric water content of the soils were investigated. In addition, the relationship between penetration indices by TDCP (TPI) and by standard dynamic cone penetrometer was established. In the field application test, relative permittivity, ground temperature, and TPI were measured along the depth. Moreover, gravimetric water contents were also measured for comparison. The experimental results showed that volumetric water contents compensated by ground temperature showed good agreement with the volumetric water contents estimated from the gravimetric water contents of the soil samples and TPI. This study suggests that the TDCP may be effectively used for the evaluation moisture contents and for the strength characterization of the subsurface.
Cooperative Localization Approach for Multi-Robot Systems Based on State Estimation Error Compensation
Authors: Zhang Shijie , Cao Yi
Published: September 2019

In order to improve the localization accuracy of multi-robot systems, a cooperative localization approach with communication delays was proposed in this paper. In the proposed method, the reason for the time delay of the robots’ cooperative localization approach was analyzed first, and then the state equation and measure equation were reconstructed by introducing the communication delays into the states and measurements. Furthermore, the cooperative localization algorithm using the extended Kalman filtering technique based on state estimation error compensation was proposed to reduce the state estimation error of delay filtering. Finally, the simulation and experiment results demonstrated that the proposed algorithm can achieve good performance in location in the presence of communication delay while having reduced computational and communicative cost.
Bidirectional Piezoelectric Energy Harvester
Authors: Čeponis Andrius , Mažeika Dalius , Kilikevičius Artūras
Published: September 2019

This paper represents a numerical and experimental investigation of the bidirectional piezoelectric energy harvester. The harvester can harvest energy from the vibrating base in two perpendicular directions. The introduced harvester consists of two cantilevers that are connected by a particular angle and two seismic masses. The first mass is placed at a free end of the harvester while the second mass is fixed at the joining point of the cantilevers. The piezoelectric energy harvester employs the first and the second out of plane bending modes. The numerical investigation was carried out to obtain optimal geometrical parameters and to calculate the mechanical and electrical characteristics of the harvester. The energy harvester can provide stable output power during harmonic and impact-based excitation in two directions. The results of the investigations showed that energy harvester provides a maximum output power of 16.85 µW and 15.9 4 µW when the base has harmonic vibrations in y and z directions, respectively. Maximum output of 4.059 nW/N and 3.1 nW/N in y and z directions were obtained in case of impact based excitation
Virtual Dual-Loop Feedback Control with Model-Construction Linear Extended State Observer for Free Space Optical Communication
Authors: Nie Kang , Ren Wei , Zhou Xi , Mao Yao
Published: September 2019

The stable alignment and transmission of free space optical communication (FSO) is susceptible to internal dynamics and external disturbances. In this paper, a virtual dual-loop feedback control (VDFC) with model-construction linear extended state observer (MCLESO), which is applied to the fast tip-tilt mirror platform to enhance the disturbance suppression ability (DSA) for FSO. MCLESO, which is modified on a classical linear extended state observer by introducing the available model information, is shown to use the input and output signal data of the system to observe total disturbances, including internal dynamics and external disturbance. Since the position and velocity signals are both observed only with the optoelectronic target detector and MCLESO, the controllers of the dual-loop feedback control (DFC) system are employed directly. This method has a more accurate control performance after model construction, which enhances the DSA of the tip-tilt mirror control system in low and medium frequency. It is also beneficial to miniaturization and cost saving by not using velocity sensors. Both simulations and experiments validate the effectiveness of the proposed method in the tip-tilt mirror control system under the condition of disturbance.
Stabilization of Polymeric Nanofibers Layers for Use as Real-Time and In-Flow Photonic Sensors
Authors: Ponce-Alcántara Salvador , Martínez-Pérez Paula , Pérez-Márquez Ana , Maudes Jon , Murillo Nieves , García-Rupérez Jaime
Published: September 2019

In order to increase the sensitivity of a sensor, the relationship between its volume and the surface available to be functionalized is of great importance. Accordingly, porous materials are becoming very relevant, because they have a notable surface-to-volume ratio. Moreover, they offer the possibility to infiltrate the target substances on them. Among other porous structures, polymeric nanofibers (NFs) layers fabricated by electrospinning have emerged as a very promising alternative to low-cost and easy-to-produce high-performance photonic sensors. However, experimental results show a spectrum drift when performing sensing measurements in real-time. That drift is responsible for a significant error when trying to determine the refractive index variation for a target solution, and, because of that, for the detection of the presence of certain analytes. In order to avoid that problem, different chemical and thermal treatments were studied. The best results were obtained for thermal steps at 190 °C during times between 3 and 5 h. As a result, spectrum drifts lower than 5 pm/min and sensitivities of 518 nm/refractive index unit (RIU) in the visible range of the spectrum were achieved in different electrospun NFs sensors.
Effects of pH Conditions and Application Rates of Commercial Humic Substances on Cu and Zn Mobility in Anthropogenic Mine Soils
Authors: Pérez-Esteban Javier , Escolástico Consuelo , Sanchis Inés , Masaguer Alberto , Moliner Ana
Published: September 2019

We studied the effects of commercial humic substances derived from leonardite at different rates (0, 0.25, 2, 10 g kg−1) and pH (4.5, 6.0, 8.0) on Cu and Zn mobility, to evaluate their use for remediation of metal contaminated mine soils and to optimize their application conditions. We conducted a single-step extraction experiment and analyzed extracts for metal concentrations, soluble organic carbon and their E4/E6 ratio (ratio of absorption at 465 to 665 nm). Metal speciation in a soil solution was simulated by the non-ideal competitive adsorption-Donnan (NICA-Donnan) model. Increasing the amount of humic substances and the pH caused higher release rates of soluble organic carbon with a lower humic/fulvic acids ratio. This led to a higher mobility of metals (up to 110 times Cu concentration in control and 12 times for Zn) due to the formation of soluble metal-humic complexes. Speciation modeling predicted that increasing rates of humic substances would result in a higher proportion of Cu and Zn associated with fulvic acids, more mobile than the humic acids fraction. Application of commercial leonardite humic substances at 2–10 g kg−1 and with pH levels similar to or below natural soil could be useful for assisted-phytoextraction of contaminated anthropogenic soils. High rates of humic substances in more alkaline conditions could entail a considerable risk of metal leaching to groundwater, toxicity and transfer to the trophic chain.
The Effects of Energy Consumption, Economic Growth and Financial Development on CO2 Emissions in China: A VECM Approach
Authors: Jian Jianhui , Fan Xiaojie , He Pinglin , Xiong Hao , Shen Huayu
Published: September 2019

As one of the largest energy consumers and the greatest emitter of CO2 in the world, China now confronts the dual challenge of reducing energy use while continuing to foster economic growth. To overcome this issue, there is a need of comprehensive economic, financial, and energy policy reforms to promote sustainable development. The objective of this paper is to examine the effects of economic growth, financial development and energy consumption on carbon dioxide emission (CO2) in China from 1982 to 2017. The study applies Johansen cointegration test and vector error correction model (VECM) to investigate the long-term equilibrium and short-term causality relationship among the four variables. The causality is also checked by using the innovative accounting approach (IAA). The empirical results show the long-term cointegration relationship between them. Evidence shows that a unidirectional Granger causality running from energy consumption to financial development. Financial development and energy consumption have a statistically significant positive impact on CO2 emissions. In the long run, economic growth can curb CO2 emissions. Hence, financial innovation should be encouraged in the country to meet the demand of sustainable development. Nevertheless, optimizing energy structure and increasing the efficiency of energy utilization can never be left out from the process of development. We add light to policy makers with the construction of carbon trading to effectively address greenhouse effects in China.
The Impact of Big Data Analytics on Company Performance in Supply Chain Management
Authors: Oncioiu Ionica , Bunget Ovidiu Constantin , Türkeș Mirela Cătălina , Căpușneanu Sorinel , Topor Dan Ioan , Tamaș Attila Szora , Rakoș Ileana-Sorina , Hint Mihaela Ștefan
Published: September 2019

Big data analytics can add value and provide a new perspective by improving predictive analysis and modeling practices. This research is centered on supply-chain management and how big data analytics can help Romanian supply-chain companies assess their experience, strategies, and professional capabilities in successfully implementing big data analytics, as well as assessing the tools needed to achieve these goals, including the results of implementation and performance achievement based on them. The research method used in the quantitative study was a sampling survey, using a questionnaire as a data collection tool. It included closed questions, measured with nominal and ordinal scales. A total of 205 managers provided complete and useful answers for this research. The collected data were analyzed with the Statistical Package for the Social Sciences (SPSS) package using frequency tables, contingency tables, and main component analysis. The major contributions of this research highlight the fact that companies are concerned with identifying new statistical methods, tools, and approaches, such as cloud computing and security technologies, that need to be rigorously explored.
Environmental Performance and Green Culture: The Mediating Effect of Green Innovation. An Application to the Automotive Industry
Authors: García-Machado Juan J. , Martínez-Ávila Minerva
Published: September 2019

Globalization and the ever-growing presence of technology have paved the way for better developmental opportunities in society. Nonetheless, these have also been to the detriment of the environment as well as sustainable development. The aim of this study is to discover the mediating effect of green innovation with regard to the relationship which exists between green culture and environmental performance in the State of Mexico’s automotive sector. The research hypotheses were formulated following an extensive study of the literature available and were based on resource- and capability-based theory, specifically, the natural-resource view of the firm (NRBV). The design of the study was non-experimental and cross-sectional with a confirmatory reach, applied to a sample of 157 observations. The proposed theoretical model was tested using partial least squares structural equation modeling (PLS-SEM). The findings provide empirical evidence that green innovation acts as a mediator variable on the relationship between green culture and environmental performance. The scientific merit of the study is found in its proposal of a hierarchical second-order model, categorized as reflective-formative, and the study’s confirmation of the role of green innovation as a mediating construct. Therefore, the findings herein can be considered as complementary to the existing body of knowledge in the field. The practical implications derived from this study will contribute to sustainable development and expand knowledge in the following areas: Government institutions, companies that operate in the sector, decision makers, academics, and practitioners who are working on this issue at different levels.
A QoE Evaluation Method for RT-HDMV Based on Multipath Relay Service
Authors: Zhan Yuzhuo , Lei Weimin , Guan Yunchong
Published: September 2019

Multipath diversity leads to a possible higher performance for real-time high definition video, especially for medical video transmission, which would improve the stability of multiple transmission paths in the symmetrical state, and avoid the potential losses of imaging information in the communication process. Most of the previous works are always based on the single-path end-to-end transmission, although the service had been demonstrated that it is unable to meet the rigorous demand for the RT-HDMV. In the paper, a multipath relay service based on the QoE (quality of experience) evaluation method is proposed for the RT-HDMV (real-time high definition medical video). The method eliminates several of the limitations in the existing methods for some conventional single-path transmission. It can fully utilize the finite network resources and transmission bandwidth to meet the users’ demands of the RT-HDMV to get a better score of the QoE. We use a four-stage framework to evaluate the QoE, which consists of constructing the multipath relay transmission for the RT-HDMV, calculating the weights of diversified QoS parameters in the multipath, designing the load distribution strategy by the mapping between the QoS (quality of service) and QoE, and redefining the rule of the QoE evaluation. Many experiments show that the proposed design scheme achieves weighting of the transmission sub-paths and computes the QoE score. Compared with the state-of-art methods in the single path transmission scene, our framework mainly gains the excellent performance for the RT-HDMV.
Heat and Mass Transfer in a Viscous Nanofluid Containing a Gyrotactic Micro-Organism Over a Stretching Cylinder
Authors: Ferdows Mohammad , Reddy M. Gnaneswara , Alzahrani Faris , Sun Shuyu
Published: September 2019

This work consists of a theoretical boundary layer analysis of heat and mass transport in a viscous fluid-embracing gyrotactic micro-organism over a cylinder. The flow governing equations are modeled through boundary layer approximations. The governing non-linear partial differential equations are lessened to a set of nonlinear ordinary differential equations using similitude transformation. The boundary layer equations are elucidated numerically, applying the spectral relaxation method with the aid of the computational software MATLAB. The impact of several pertinent parameters on flow convective characteristic phenomena are explored through the use of graphs and tables and are discussed with in-depth physical descriptions. In addition, the friction factor, the rate of heat transfer, rate of mass transfer, and the density number of the motile microorganism are also presented with respect to the above controlled parameters. It is noticed that for the increasing values of the magnetic parameter with reductions and enhancements, the density of the motile microorganism is a declining function of, and the concentration field enhances with the strengthening of, whereas it reduces with the rise of. Furthermore, the streamline patters are emphasized for the impact of controlled flow variables. Current outcomes are compared with the available results from previous cases and are observed to be in agreement.
Study on a Surrounding Rock Pressure Calculation Method for Super-Large Section Highway Tunnels
Authors: Gao Hongjie , He Ping , Chen Zheng , Li Xinyu
Published: September 2019

This paper presents new correlations for estimating the surrounding rock pressure of symmetrically shaped tunnels based on a symmetrical numerical model. Surrounding rock pressure is defined as the load acting on the support structure due to the deformation of the surrounding rock after tunnel excavation. Surrounding rock pressure is directly related to the selection of the lining structure and the determination of support parameters. The main challenge in designing and proceeding with the construction process is choosing a calculation method for the surrounding rock pressure for super-large sections, and this has been the focus of research among the tunnel research community. The excavation area of Liantang tunnel of Shenzhen Eastern Transit Expressway (China) is over 400 m2, making it the largest highway tunnel in the world so far. Based on this project, this paper analyses the applicability of various traditional methods of calculating the surrounding rock pressure for super-large section tunnels. In addition, based on the Tunneling Quality Index (Q), the factor of span is introduced into the method of calculating the surrounding rock pressure using the numerical simulation results of super-large symmetrical tunnels with different values of Q and different spans. Additionally, calculated correlations that could quickly estimate the surrounding rock pressure of tunnels are obtained. The comparison of surrounding rock pressures between the estimated and monitoring results of Liantang tunnel and more than 30 projects around the world effectively proves the rationality and universal applicability of the proposed correlations. This method could provide engineers and designers with a quick way to predict the surrounding rock pressure of deep super-large section underground structures during their design and construction stage.
Twenty Years of Progress Toward West Nile Virus Vaccine Development
Authors: Kaiser Jaclyn A. , Barrett Alan D.T.
Published: September 2019

Although West Nile virus (WNV) has been a prominent mosquito-transmitted infection in North America for twenty years, no human vaccine has been licensed. With a cumulative number of 24,714 neurological disease cases and 2314 deaths in the U.S. since 1999, plus a large outbreak in Europe in 2018 involving over 2000 human cases in 15 countries, a vaccine is essential to prevent continued morbidity, mortality, and economic burden. Currently, four veterinary vaccines are licensed, and six vaccines have progressed into clinical trials in humans. All four veterinary vaccines require multiple primary doses and annual boosters, but for a human vaccine to be protective and cost effective in the most vulnerable older age population, it is ideal that the vaccine be strongly immunogenic with only a single dose and without subsequent annual boosters. Of six human vaccine candidates, the two live, attenuated vaccines were the only ones that elicited strong immunity after a single dose. As none of these candidates have yet progressed beyond phase II clinical trials, development of new candidate vaccines and improvement of vaccination strategies remains an important area of research.
The Current View of Retroviruses as Seen from the Shoulders of a Giant
Authors: Hejnar Jiří , Ruml Tomáš
Published: September 2019

It has now been more than two years since we said our last goodbye to Jan Svoboda (14 [...]
Comprehensive Evaluation and Source Apportionment of Potential Toxic Elements in Soils and Sediments of Guishui River, Beijing
Authors: Wang Jiankang , Gao Bo , Yin Shuhua , Liu Laisheng , Xu Dongyu , Li Yanyan
Published: September 2019

This study investigated the concentrations and spatial distributions, ecological risks, and potential pollution sources of potential toxic elements (PTEs) in the soils and sediments collected from the Guishui River (GSR) in Beijing, China. Multiple methods for pollution assessment and source identification of PTEs in the sediments/soils were used, including analysis of the physicochemical properties, Geo-accumulation index (Igeo), potential ecological risk index (RI), Pearson correlation, principal component analysis (PCA), and Pb isotopic ratio analysis. The results showed that PTE concentrations in the sediments/soils were similar to the soil background values (BV) of Beijing, except for Cd. Maximum Cd concentrations in soils were far below the guideline of the Environmental Quality Standard for Soils in China. PTE concentrations in the soils were slightly higher than those in the sediments. Upstream to downstream of GSR, PTEs concentrations in the soils and sediments remained stable. Pollution assessment based on Igeo and RI indicated that Cd was the main contaminant with moderate pollution levels. PCA results showed that Cd originated from anthropogenic sources, mainly including pesticide and fertilizer residues, while other metals mainly originated from natural sources. Further source identification using Pb isotopic ratios and PCA indicated that Cu, Pb, and Zn in GSR originated from anthropogenic sources (aerosols and coal combustion) and atmospheric deposition was considered as the primary input pathway.
Reverse QMRA as a Decision Support Tool: Setting Acceptable Concentration Limits for Pseudomonas aeruginosa and Naegleria fowleri
Authors: Rasheduzzaman Md , Singh Rajveer , Haas Charles , Tolofari Dienye , Yassaghi Hamed , Hamilton Kerry , Yang Zhao , Gurian Patrick
Published: September 2019

Opportunistic premise plumbing pathogens such as Pseudomonas aeruginosa and Naegleria fowleri are a growing concern in building water systems because of their potential risks to human health. The aim of this study was to determine the critical concentrations of P. aeruginosa and N. fowleri in water that are associated with meaningful public health risks. To determine these concentrations, a reverse quantitative microbial risk assessment (QMRA) was conducted. Environmental concentrations of P. aeruginosa and N. fowleri corresponding to the risk target of one micro-disability-adjusted life year (DALY) per person per year and 10−4 annual risks of illness were calculated for several applicable exposure scenarios. To calculate the concentration of P. aeruginosa, cleaning contact lenses with potentially contaminated tap water in the absence of an appropriate cleaning solution was considered. For N. fowleri, two exposure scenarios, recreational exposure (swimming) and nasal cleansing (via the use of a neti pot™ or similar device) were considered. The highest critical concentration for P. aeruginosa was found to be 33 CFU/L with a 95% confidence interval of (2.0, 118) for the drop exposure scenario using the 10−4 annual risk target. For N. fowleri, based on the DALY approach, critical concentrations were 0.000030 N. fowleri/L for swimming and 0.00000060 N. fowleri/L for neti pot™ use scenario. Considering heat inactivation, the critical concentration limits for P. aeruginosa using the DALY approach and the 10−4 annual risk target approach were found to be 0.55 CFU/L and 55 CFU/L, respectively. For N. fowleri, the 10−4 annual risk target approach resulted in 0.022 N. fowleri/L and the DALY approach resulted in 0.00000064 N. fowleri/L for the neti pot™ scenario. For P. aeruginosa, N50 (the median infective dose) and alpha (α) contributed the most and contact rates the least to the variability and uncertainty of the estimates for all the scenarios. For N. fowleri, N50 and contact rates contributed the most and α the least to the variability and uncertainty to calculate the concentrations for all the scenarios. The QMRA framework implemented in this research can be used to incorporate more information regarding opportunistic pathogens to inform management decisions, and to prioritize the best interventions regarding estimated reduction in infections caused by opportunistic pathogens.
Algae Growth Distribution and Key Prevention and Control Positions for the Middle Route of the South-to-North Water Diversion Project
Authors: Zhu Jie , Lei Xiaohui , Quan Jin , Yue Xia
Published: September 2019

The Middle Route of the South-to-North Water Diversion Project (MRP) is an important water supply for 20 large cities and 100 counties in Northern China. However, since 2016, the growth of large filamentous algae clusters has threatened the safety of the main canal water supply and water quality. In this study, a field investigation, monitoring, and hydrodynamic simulation were performed to analyze the hydrodynamic habitat conditions in areas with vigorous algae growth and establish a relationship between the hydrodynamic habitat conditions of the main canal and the growth, distribution, and correlation of macrobenthic algae in the main canal. The results showed that: (1) algae zones in the main canal are more likely to appear along curves, and the largest algal zone was at the front of the large curved section; (2) the length of the algae growth zone is related to the flow rate; and (3) a lower flow velocity in the main canal facilitates faster growth of an algae zone. This study provides specific and effective suggestions for the key prevention and control positions, which has important guidance on improving the efficiency of algae control in the main canal.
Morphological Changes of the Lower Tedori River, Japan, over 50 Years
Authors: Minh Hai Dang , Umeda Shinya , Yuhi Masatoshi
Published: September 2019

Long-term variation in the morphological characteristics of rivers is complicated as a result of temporally and spatially variable natural processes and anthropogenic disturbances. Better understanding of their relationship is therefore important for river basin management. The present study conducted a detailed analysis of a long-term dataset consisting of a 58-year topographic survey and related data on human impact to clarify the long-term variation in the morphological characteristics of the lower Tedori River in Japan. An empirical model was established through the assessment of spatiotemporal variations in nonlinear rates of adjustment. The results indicated that sediment extraction and dam construction profoundly affected the morphological characteristics of the lower Tedori River and that the vertical adjustment of the river channel experienced five phases. Degradation occurred from 7 to 16 km upstream from the river mouth over all phases. Two aggradation phases following two degradation phases were observed from the river mouth to 2 km upstream. Aggradation and degradation phases appeared alternately from 2 to 7 km. The representative nonlinear rates of vertical adjustment in the second phase were the highest compared with those in the other phases in the entire reach. The correlation analysis revealed that the incision phase was mostly coupled with channel narrowing, while widening followed the deposition phase. It was deduced from aerial photo analysis and a comparison between slope and empirical critical slope that the pattern in the lower Tedori River was braided during the period 1950–2000.
Queratocisto odontogênico em região anterior da maxila: relato de caso
Authors: Araújo Stella , Kindely Ramos De Oliveira Laisa , Mombrini Pigatti Fernanda , Mayrink Gabriela
Published: September 2019

Introdução: O queratocisto odontogênico é uma lesão cística intra-óssea que se origina do resto celular da lâmina dentária. Possui crescimento lento, assintomático e é comumente encontrado em radiografias de rotina. É mais prevalente no sexo masculino entre a 2ª e 3ª décadas de vida e acomete preferencialmente a mandíbula. Objetivo: relatar um caso de queratocisto em região anterior da maxila e realizar uma revisão dos tratamentos que estão disponíveis para essa lesão. Relato de caso: paciente do sexo feminino, 46 anos de idade, durante exame radiográfico de rotina, exibiu área radiolúcida unilocular com borda esclerótica definida que se estendia do dente 11 ao 24. No exame clínico não foi possível notar nenhuma expansão da cortical óssea. Foi realizada biópsia e instalado, no mesmo momento cirúrgico, dispositivo para descompressão da lesão. Após análise histopatológica e confirmação diagnóstica, a paciente foi submetida a enucleação cirúrgica. Conclusão: o paciente permanece em acompanhamento há 3 anos sem sinais clínicos ou radiográficos de recidiva da lesão.