bluuebunny/crossref_metadata_2025 huggingface dataset:
Central North Pacific SST anomalies linked late winter haze to Arctic sea ice
Authors: Yang Quan , Yuan Dongmin
Published: February 2020

Haze pollution in the North China Plain is becoming more serious and consequently causes inconvenience in daily life and harms health. The inter‐annual variation of haze days in the North China Plain in late winter (February and March) is closely related to the East Siberian Sea and Chukchi Sea ice in October, and the Pacific sea surface temperature (SST) plays a key role in delivering the effects of the sea ice on the haze. When the East Siberian Sea and Chukchi Sea ice increases in October, the October and November SST in the region over Minami‐Tori Shima and Midway Atoll decreases. This reduced SST then lowers the January and February SST around the northwestern side of the Hawaiian Islands. The lower SST around the northwestern side of the Hawaiian Islands modulates the atmospheric circulation and makes the diffusion conditions and water vapour conditions in the North China Plain more conducive to the accumulation and growth of pollutants. Large ensemble simulations from the Community Earth System Model validate the process whereby the East Siberian Sea and Chukchi Sea ice affects the SST in the aforementioned regions. The effect of changes in the SST around the northwestern side of the Hawaiian Islands on the meteorological conditions over the North China Plain was verified by numerical experiments using version 4 of the Community Atmosphere Model.
Improved bone regeneration using bone anabolic drug conjugates (C3 and C6) with deproteinized bovine bone mineral as a carrier in rat mandibular defects
Authors: Sheikh Zeeshan , Abdallah Mohamed‐Nur , Al‐Jaf Faik , Chen Gang , Hamdan Nader , Young Robert N. , Grynpas Marc D. , Glogauer Michael
Published: February 2020

Background

Deproteinized bovine bone mineral (DBBM) has been extensively studied and used for bone regeneration in oral and maxillofacial surgery. However, it lacks an osteoinductive ability. We developed two novel bone anabolic conjugated drugs, known as C3 and C6, of an inactive bisphosphonate and a bone activating synthetic prostaglandin agonist. The aim was to investigate whether these drugs prebound to DBBM granules have the potential to achieve rapid and enhanced bone regeneration.

Methods

Bilateral defects (4.3 mm diameter circular through and through) were created in mandibular angles of 24 Sprague‐Dawley rats were filled with DBBM Control, DBBM with C3 or DBBM with C6 (n = 8 defects per group/ each timepoint). After 2 and 4 weeks, postmortem samples were analyzed by microcomputed tomography followed by backscattering electron microscopy and histology.

Results

DBBM grafts containing the C3 and C6 conjugated drugs showed significantly more bone formation than DBBM control at 2 and 4 weeks. The C6 containing DBBM demonstrated the highest percentage of new bone formation at 4 weeks. There was no significant difference in the percentage of the remaining graft between the different groups at 2 or 4 weeks.

Conclusions

DBBM granules containing conjugated drugs C3 and C6 induced greater new bone volume generated and increased the bone formation rate more than the DBBM controls. This is expected to allow the development of clinical treatments that provide more predictable and improved bone regeneration for bone defect repair in oral and maxillofacial surgery.
Online analysis of minerals from sulfide ore using near‐infrared Raman spectroscopy
Authors: Uusitalo Sanna , Soudunsaari Tuomas , Sumen Juha , Haavisto Olli , Kaartinen Jani , Huuskonen Jarmo , Tuikka Aki , Rahkamaa‐Tolonen Katariina , Paaso Janne
Published: February 2020

Efficient recovery of minerals from bedrock ore requires precise knowledge of the mineral levels during enrichment processes. Froth flotation is a commonly used method for efficient separation of different minerals from finely grinded sulfide ore. The mineral level information is an important tool for the optimization of flotation process parameters as it is uneconomical to make mineral products with unacceptably low concentrations and to lose a share of the valuable minerals of the ore to the tailings. Online mineral control is commonly executed with X‐ray fluorescence detection or laser‐induced breakdown spectroscopy, which detect the elements of the minerals during flotation. Unfortunately, in case of sulfide ores, the method suffers from inadequate detection of lightweight materials such as sulfur and the common nature of iron, as iron is constantly present in several different minerals found in sulfide ores. Raman spectroscopy can be used to detect the minerals instead of mere elements of ore. This paper presents the study of Raman spectroscopy for online detection of enriched sulfide ore minerals from froth flotation. The Raman instrument with a custom‐made probe connector allowed for the recording of good quality Raman spectra during froth flotation and for the identification and analysis of the valuable minerals levels. The comparison of Raman analysis to online X‐ray fluorescence and offline mineral liberation analysis show that Raman spectroscopy is a suitable method for the online analysis of sulfide ores.
Can degraded soils be improved by ripping through the hardpan and liming? A field experiment in the humid Ethiopian Highlands
Authors: Tebebu Tigist Y. , Bayabil Haimanote K. , Steenhuis Tammo S.
Published: February 2020

Land degradation in developing countries is exacerbating hardpan development that causes the formation of perched watertable, which in turn results in increased runoff and erosion. To reduce overland flow and erosion, percolation through the hardpan needs to be improved. One successful way to achieve this is ripping off the hardpan and plausibly liming. However, in the highlands of Ethiopia, there is little information available on these two techniques. The objectives of this study were, therefore, to determine the effects of ripping off degraded soils on runoff and erosion rates and whether liming would improve the effectiveness of ripping. A field study was conducted in the Anjeni watershed. Thirty‐two experimental runoff plots were installed across the watershed. Conventional tillage at 15 cm depth and ripping to 30, 45, and 60 cm depths were applied with and without lime amendments. Results showed that ripping to 60 cm depth resulted in a significant reduction of runoff. However, liming increased runoff response, on average by 10%. In contrast to the reduction in runoff amounts, an increase in ripping depth increased the amount of soil loss especially during the first storms at the beginning of the monsoon rainy season. Liming significantly decreased soil loss by up to 35%. Although plots with deep ripping plus liming had greater runoff production than other plots, soil loss was less. Overall, the findings suggest that deep ripping has promise but more research is needed before widely implemented.
Stochastic dynamics of Cyanobacteria in long‐term high‐frequency observations of a eutrophic lake
Authors: Carpenter Stephen R. , Arani Babak M. S. , Hanson Paul C. , Scheffer Marten , Stanley Emily H. , Van Nes Egbert
Published: February 2020

Concentrations of phycocyanin, a pigment of Cyanobacteria, were measured at 1‐min intervals during the ice‐free seasons of 2008–2018 by automated sensors suspended from a buoy at a central station in Lake Mendota, Wisconsin, U.S.A. In each year, stochastic‐dynamic models fitted to time series of log‐transformed phycocyanin concentration revealed two alternative stable states and random factors that were much larger than the difference between the alternate stable states. Transitions between low and high states were abrupt and apparently driven by stochasticity. Variation in annual magnitudes of the alternate states and the stochastic factors were not correlated with annual phosphorus input to the lake. At daily time scales, however, phycocyanin concentration was correlated with phosphorus input, precipitation, and wind velocity for time lags of 1–15 d. Multiple years of high‐frequency data were needed to discern these patterns in the noise‐dominated dynamics of Cyanobacteria.
THE LEADER’S CHS ROLE: CHIEF HELP SEEKER
Authors: Baker Wayne
Published: February 2020

This article explains the importance of leaders asking for help, which can be difficult for leaders. Various research is cited, including from the author's book All You Have to Do Is Ask, and from related academic studies. Four reasons in particular are examined in detail for why it can be difficult to ask for help: The Sage Syndrome, Fear of Looking Foolish, No One Can Help, and Not Knowing How to Make an Effective Request. Within the latter, Effective requests follow SMART criteria, though my definition of key elements are different from the conventional definition of SMART. In particular, S is for specific. M is for meaningful. A is action‐oriented. R means realistic. T means time bound. In addition, five ways to be the Chief Help Seeker are outlined: 1. Be a Giver‐Requester. 2. Start at the Top. 3. Build Your Brain Trust. 4. Tap Your Dormant Ties. 5. Use Your Technology Megaphone. Many technologies can be tapped to generate a culture of asking for, giving, and receiving help; such as videoconferencing, messaging apps like Yammer or Chatter, and customized collaboration technology platforms such as Givitas, one that I helped to develop based on the principles in the book.
Smart Designing of Tragacanth Gum by Graft Functionalization for Advanced Materials
Authors: Verma Chetna , Pathania Deepak , Anjum Sadiya , Gupta Bhuvanesh
Published: February 2020

Tragacanth gum is a novel polysaccharide which offers interesting features in terms of high hydrophilicity, good biocompatibility, and biodegradability. The engineering of hydrogels requires careful designing of their macromolecular structures so that desirable features may be incorporated into the material. Graft polymerization has come up as an interesting approach to develop molecules for drug delivery, wound care systems, and infection‐resistant materials. The most important aspect of graft functionalization is the proper control over physico‐chemical properties of the grafted matrix. The extent of functionalization may be governed by the grafting parameters and may lead to the chemical designing of the molecule in a controlled manner. This opens up enormous possibilities of developing materials for a wide range of applications as advanced materials.
On the evolution equation of compressible vortex sheets
Authors: Morando A. , Secchi P. , Trebeschi P.
Published: February 2020

We are concerned with supersonic vortex sheets for the Euler equations of compressible inviscid fluids in two space dimensions. For the problem with constant coefficients we derive an evolution equation for the discontinuity front of the vortex sheet. This is a pseudo‐differential equation of order two. In agreement with the classical stability analysis, if the Mach number satisfies , the symbol is elliptic and the problem is ill‐posed. On the contrary, if then the problem is weakly stable, and we are able to derive a wave‐type a priori energy estimate for the solution, with no loss of regularity with respect to the data. Then we prove the well‐posedness of the problem, by showing the existence of the solution in weighted Sobolev spaces.
Global relaxation and nonrelativistic limit of nonisentropic Euler‐Maxwell systems
Authors: Chao Na , Yang Yongfu
Published: February 2020

The aim of this paper is to investigate smooth solutions to Cauchy (or periodic) problem for a nonisentropic Euler‐Maxwell system with small parameters. For initial data close to constant equilibrium states, we prove the global‐in‐time convergence of the Euler‐Maxwell system as parameters go to zero. The limit systems are the drift‐diffusion system and the nonisentropic Euler‐Poisson system, respectively.
Differential gene regulation in selected lines for high and low sperm production in male guppies
Authors: Cattelan Silvia , Vidotto Michele , Devigili Alessandro , Pilastro Andrea , Grapputo Alessandro
Published: February 2020

In species where females mate with more than one male during the same reproductive event, males typically increase the number of sperm produced to boost their fertilization share. Sperm is not limitless, however, and theory predicts that their production will come at the cost of other fitness‐related traits, such as body growth or immunocompetence, although these evolutionary trade‐offs are notoriously difficult to highlight. To this end, we combined artificial selection for sperm production with a transcriptome analysis using Poecilia reticulata, a fish characterized by intense sperm competition in which the number of sperm transferred during mating is the most important predictor of fertilization success, yet sperm production is highly variable among males. We compared the brain and testes transcriptome in male guppies of lines artificially selected for high and low sperm production by identifying pivotal differentially expressed gene sets that may regulate spermatogenesis and immune function in this species. Despite the small differences in single genes' expression, gene set enrichment analysis showed coordinated gene expression differences associated with several pathways differentially regulated in the two selection lines. High sperm production males showed an upregulation of pathways related to immunosuppression and development of spermatozoa indicating a possible immunological cost of sperm production.
Evaluating alerts: All alerts are not equally effective
Authors: Cheng Eric M. , Wu Allan D. , Wilson Andrew M.
Published: February 2020

See article on pages 640–644 in this issue.
Community oriented in‐network caching and edge caching for over‐the‐top services in adaptive network conditions to improve performance
Authors: Pandey Suman , Park Soyoung , Choi Mi Jung
Published: February 2020

Over‐the‐top (OTT) services such as Netflix, Amazon Prime, and YouTube generate the most dominant form of traffic on the Internet today. There is increasingly high demand for resource intensive 3D contents, interactive media, 360 media, and user‐generated contents. As the amount of contents keep increasing in multiple folds, it is important to cache contents intelligently. Caching algorithm needs to exploit in‐network caching, community‐based pre‐caching, and a combined approach. Hence, we survey CDN‐based edge caching infrastructures including OpenConnect (Netflix) and Google Edge, followed by CCN based in‐network caching. We implement and compare four different approaches for caching contents including (1) in‐network caching, (2) edge caching, (3) community‐based in‐network caching, and (4) community‐based edge caching. We run our algorithms on adaptive network conditions with different topologies, cache size, content popularity, and request arrivals in and compared the delay for all these four approaches. We verify our model by calculating important performance parameters including hop count, redundancy, and hop count variances. Hopcount is an important performance parameter as it influences the processing, queuing, and transmission delays. We focus on determining if an in‐network caching approach is any better than edge caching. We reach several conclusions. First, in most of the scenarios, community‐based in‐network caching performs the best. Second, if the cache size is lesser than 30% of the total content size then community‐based edge caching is better for less popular contents. Finally, our statistical analysis also reveals that a community‐based edge caching mechanism is least affected by varying cache sizes and dynamic user behavior, which makes it a better choice for providing Service Level Agreement.
Flexible electrospun PET/TiO2 nanofibrous structures: Morphology, thermal and mechanical properties
Authors: Gallah Hajer , Mighri Frej , Ajji Abdellah , Bandyopadhyay Jayita
Published: February 2020

In this study, a solvothermal method was used to synthesize anatase titanium dioxide (TiO2) nanoparticles in the presence of oleic acid (OA) and oleylamine (OM) as morphology‐directing agents. Functional nanocomposite fibers of poly(ethylene terephtalate) (PET) containing surfactants‐capped TiO2 nanoparticles were developed by electrospinning technique. The morphology, thermal stability and mechanical properties of PET/TiO2 nanocomposite mats were investigated as a function of TiO2 concentration. Morphology investigation showed interesting results in terms of the level of TiO2 dispersion inside the fibers and the improvement of the quality (smoothness) of the fibers' surface when the synthesized nanorhombic TiO2 nanoparticles were used compared to a commercial P25 TiO2 (AEROXIDE P25). The presence of OA and OM on the surface of the nanorhombic synthesized TiO2 led to a significant improvement of TiO2 dispersion inside the PET matrix. Furthermore, the physical interaction between the PET matrix and TiO2 nanoparticles resulted in an enhanced thermal stability, and an increase of the Young's modulus and tensile strength for TiO2 concentration up to 10 wt%.
Differential activation of G protein‐mediated signaling by synthetic cannabinoid receptor agonists
Authors: Sachdev Shivani , Banister Samuel D. , Santiago Marina , Bladen Chris , Kassiou Michael , Connor Mark
Published: February 2020

Synthetic cannabinoid receptor agonists (SCRAs) are new psychoactive substances associated with acute intoxication and even death. However, the molecular mechanisms through which SCRAs may exert their toxic effects remain unclear—including the potential differential activation of G protein subtypes by cannabinoid receptor type 1 (CB1), a major target of SCRA. We measured CB1‐mediated activation of Gαs and Gαi/o proteins by SCRAs by examining stimulation (pertussis toxin, PTX treated) as well as inhibition (non‐PTX treated) of forskolin (FSK)‐induced cyclic adenosine monophosphate (cAMP) accumulation in human embryonic kidney (HEK) cells stably expressing CB1. Real‐time measurements of stimulation and inhibition of cAMP levels were made using a BRET biosensor. We found that the maximum concentration of SCRAs tested (10 µmol L−1), increased cAMP levels 12%‐45% above that produced by FSK alone, while the phytocannabinoid THC did not significantly alter cAMP levels in PTX‐treated HEK‐CB1 cells. All SCRAs had greater potency to inhibit FSK‐induced cAMP levels than to stimulate cAMP levels. The rank order of potencies for SCRA stimulation of cAMP (Gαs) was PB‐22 > 5F‐MDMB‐PICA > JWH‐018 ≈ AB‐FUBINACA > XLR‐11. By contrast, the potency of SCRAs for inhibition of cAMP (Gαi/o) was 5F‐MDMB‐PICA > AB‐FUBINACA > PB‐22 > JWH‐018 > XLR‐11. The different rank order of potency and EMax of the SCRAs to stimulate Gαs‐like signaling compared to Gαi/o signaling suggests differences in G protein preference between SCRAs. Understanding the apparent differences among these drugs may contribute to unravelling their complex effects in humans.
Autonomous aerial robot using dual‐fisheye cameras
Authors: Gao Wenliang , Wang Kaixuan , Ding Wenchao , Gao Fei , Qin Tong , Shen Shaojie
Published: February 2020

Safety is undoubtedly the most fundamental requirement for any aerial robotic application. It is essential to equip aerial robots with omnidirectional perception coverage to ensure safe navigation in complex environments. In this paper, we present a light‐weight and low‐cost omnidirectional perception system, which consists of two ultrawide field‐of‐view (FOV) fisheye cameras and a low‐cost inertial measurement unit (IMU). The goal of the system is to achieve spherical omnidirectional sensing coverage with the minimum sensor suite. The two fisheye cameras are mounted rigidly facing upward and downward directions and provide omnidirectional perception coverage: 360° FOV horizontally, 50° FOV vertically for stereo, and whole spherical for monocular. We present a novel optimization‐based dual‐fisheye visual‐inertial state estimator to provide highly accurate state‐estimation. Real‐time omnidirectional three‐dimensional (3D) mapping is combined with stereo‐based depth perception for the horizontal direction and monocular depth perception for upward and downward directions. The omnidirectional perception system is integrated with online trajectory planners to achieve closed‐loop, fully autonomous navigation. All computations are done onboard on a heterogeneous computing suite. Extensive experimental results are presented to validate individual modules as well as the overall system in both indoor and outdoor environments.
Study of Molybdenum Disulfide as a Negative Electrode Additive for Stationary Flooded Lead Acid Batteries with Tubular Positive Plates
Authors: Arun S. , Arul C. , Mithin Kumar S. , Venkat Kiran Uday , Mayavan Sundar
Published: February 2020

Two dimensional layered molybdenum disulfide (MoS2) nanosheets possess great potential for lithium‐ion batteries, but their role in lead‐acid batteries (LAB) is not well known and documented. In this work, for the first time, full scale tubular positive flooded lead‐acid battery containing MoS2 in negative electrode was compared to control battery containing only carbon black for stationary/float application. Discharge capacity and an endurance test for 2000 h under constant current charging regime were investigated as per the Indian standard for testing stationary LAB (with tubular positive plate) in monobloc container (IS 13369 : 1992, reaffirmed in 2017). Inclusion of MoS2 does not negatively impact discharge capacity or endurance performance; instead, it improves these parameters 2–5 % over control battery. A significant drop in charging voltage is observed in the battery containing MoS2 throughout 2000 h of endurance testing. A battery containing MoS2 passes a similar current of 15 A at 15.2 V as control battery at 15.8 V. Battery containing MoS2, therefore, could be recharged at lower voltages than control batteries to reach identical Ah, thus delaying the onset of common failure mechanism, i. e., grid corrosion associated with high charging voltages.
Oxygen Defects in Promoting the Electrochemical Performance of Metal Oxides for Supercapacitors: Recent Advances and Challenges
Authors: Zhang Xiyue , Liu Xiaoqing , Zeng Yinxiang , Tong Yexiang , Lu Xihong
Published: February 2020

Metal oxides (MOs) with multiple active sites are regarded as one of the most potential active materials for high‐performance supercapacitor (SC) constructions. Engineering oxygen vacancies into MOs can effectively modulate their electronic properties, subtly induce impurity states in their bandgaps, and considerably optimize their electrical conductivity. Benefiting from these advantageous properties, the resultant oxygen‐defective electrodes generally embed more electrochemical active sites and present better charge storage capability in contrast to the pristine sample. Particular research attention has been given to the realization of precise oxygen vacancy introduction into MOs and the fine tuning of their properties. This review presents an overview of recent accomplishments in developing new oxygen‐defective MOs for advanced SC assembly. Different strategies for oxygen vacancy productions are summarized and compared. The specific roles of oxygen vacancies in the electrochemical performance enhancement are fully addressed and the relevant impact factors are discussed in detail. Finally, the key challenges and future opportunities in this rapidly developing field are highlighted.
Efficient CO2 Reduction to HCOOH with High Selectivity and Energy Efficiency over Bi/rGO Catalyst
Authors: Duan Yan‐Xin , Liu Kai‐Hua , Zhang Qi , Yan Jun‐Min , Jiang Qing
Published: February 2020

The electroreduction of carbon dioxide (CO2) to value‐added fuels is of great significance to meet the ever‐increasing energy and environmental challenges. So far, desirable selectivity and Faradaic efficiency for CO2 reduction can be obtained over most electrocatalysts. However, improving cathodic energy efficiency is still neglected in research. Herein, a facile reduction method is first presented to synthesize the ultrafine non‐noble bismuth (Bi) nanoparticles anchored on rGO (Bi/rGO). As expected, the Bi/rGO catalyst exhibits excellent electrochemical performance on CO2 reduction to form formic acid (HCOOH), with very high Faradaic efficiency (up to 98%), favorable stability (over 12 h), and especially outstanding cathodic energy efficiency (up to 71%). Further, density functional theory (DFT) calculations are performed to investigate the possible reaction mechanism for reduction of CO2 to HCOOH.
Constructing a Spectral Down Converter to Enhance Cu(In,Ga)Se2 Solar Cell Performance Using Yttrium Aluminum Garnet:Ce3+ Ceramics
Authors: Xiong Zhiyu , Gong Junbo , Xiong Yuan , Lan Yuchi , Yin Min , Ding Zejun , Zhang Zengming , Xiao Xudong
Published: February 2020

Spectral conversion has been widely applied in the field of luminescence and is potentially beneficial for photovoltaic solar cells. However, more was said than done for the down‐conversion effect in the past, and quite a number of existing reports overclaimed the observed performance enhancement from down conversion either by wrongly identifying the contributions or by unfairly comparing with an inappropriate reference. Herein, Ce‐doped Y3Al5O12 ceramics with suitable absorption and photoluminescence properties are chosen as the down‐conversion material for Cu(In,Ga)Se2 (CIGS) solar cells. By properly designing optical structures to integrate the down‐conversion material with the CIGS solar cell, the fluorescent photons are efficiently guided to the CIGS absorber layer in addition to eliminating the scattering and maintaining the antireflection (AR) for incident light. The Y3Al5O12:Ce3+ ceramic down converter on CIGS solar cells can bring an enhancement of 0.53 mA cm−2 to the short‐circuit current density solely from down conversion, which is responsible for the major increase in conversion efficiency from 18.5% to 19.0%. A positive down‐conversion effect is demonstrated over AR layer‐coated CIGS solar cells without misclaiming contributions from other accompanied effects or jeopardizing any other accompanying effects.
Tank Vibration Analysis of an Extra‐High‐Voltage Transformer
Authors: Konishi Yoshinori , Kato Masamichi , Hasegawa Masayuki , Aoyama Hikaru , Onuki Motohiko , Matsumoto Satoshi
Published: February 2020

In recent years, measurement of transformer vibration is being carried out as a means of detecting the looseness and deformation of its windings. Conventionally, the vibration components of even multiples of the power supply frequency (electrically generated vibration) were analyzed to diagnose the transformer. On the other hand, the natural vibrational frequencies of the winding structures represent their conditions, and the changes of these frequencies must be representing the changes in their pre‐stress or displacement. We have measured the tank vibration of an extra‐high‐voltage transformer and investigated the dependence of load current, voltage, and temperature of the oil. As a result, although the electrically generated vibration has a complicated dependence, the winding's natural frequency is not affected by the current and voltage, and the influence of the oil temperature is not very large. It is considered that the natural vibrational frequencies of the windings are a suitable index for transformer diagnosis. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Studying method of underivatized determination glyphosate, glufosinate and their metabolites in drinking water
Authors: Giang Le Truong , Thien Tran Lam Thanh , Yen Dao Hai
Published: February 2020

In Vietnam, glyphosate, one of the most popular herbicides, has recently been prohibited in agriculture due to indiscriminate use and its negative effect on the environment and human's health. Direct analysis and determination glyphosate, glufosinate and their metabolites in environmental samples such as water has get in numerous difficulties due to their simple structure, high polarity and complex formation with different components in the matrices. Therefore, in this research study, we have initially developed a method using ultra‐high performance liquid chromatography (UPLC) coupled with high resolution mass spectrometry with Q‐Orbitrap mass analyzer to analyze anionic compounds such as glyphosate, glufosinate and their metabolites. The use of this system provides low limit of detection (LOD) and quantification (LOQ) of method were 0.003 mg/kg and 0.015 mg/kg, respectively. With respect of sample treatment, we combined C18 and MAX materials in order to obtain the most effective clean up section and high recovery varying from 70 to 120 %.
The effect of nano‐silver on the properties of epoxidized rubber seed oil composite
Authors: Thuy Nguyen Thi , Van Trung Nguyen , Tuan Pham Anh , Duc Vu Minh
Published: February 2020

The Unidrive X1000 CAT mixer was used to disperse nano‐silver into matrix resin. The field emission scanning electron micrograph showed the flock of nano‐silver has burst into smaller clusters and dispersed evenly in epoxidized rubber seed oil. Two bacterial strains: gram‐positive bacterial (S. aureus) and gram‐negative bacterial (E. coli) were used to evaluate the antibacterial property of sample. The results showed matrix resin without nano‐silver possessed antibacterial property with both strains. The presence of nano‐silver raised the gram‐positive antibacterial property but reduced gram‐negative antibacterial property of matrix resin. The viscosity of matrix resin containing different nano‐silver contents was unchanged except 100 ppm. Moreover, the presence of nano‐silver has prolonged the and curing time but increased maximum exothermal temperature of emission. In general, the presence of nano‐silver improved strongly in mechanical properties of composite especially nano‐silver content of 20 to 60 ppm.
Preparation of magnetic nanocomposite with modified polyguanidine and its antibacterial properties
Authors: Lan Pham Thi , Mai Phan Thi Tuyet , Minh Vu Xuan , Hanh Le Thi My , Van Bien Tran , Thao Do Thi , Dung Nguyen Tuan
Published: February 2020

Guanidine‐based polymers are well‐known strong antimicrobial agents against a wide range of microorganisms. However, the high water solubility restricted their potential applications in the field of water treatment. In this study, polyguanidine (PG) has been modified with epichlorohydrin (Ep) and then used for synthesis of nanocomposite with Fe3O4 nanoparticles. The intrinsic viscosity measurements of modified product showed clearly that the viscosity increased with the increasing of Ep content. The characterization results indicated that magnetite Fe3O4/PG‐Ep nanocomposites were successfully synthesized, with 20‐30 nm particle size and high saturation magnetization, 62 emu.g‐1. The TGA results showed that PG‐Ep amount containing in the nanocomposite was about 10 % (wt.). As‐prepared nanocomposite Fe3O4/PG‐Ep demonstrated good antibacterial activity against Escherichia coli and had the potential to be used in disinfection applications.
Localization elements and zip codes in the intracellular transport and localization of messenger RNAs in Saccharomyces cerevisiae
Authors: Chaudhuri Anusha , Das Subhadeep , Das Biswadip
Published: February 2020

Intracellular trafficking and localization of mRNAs provide a mechanism of regulation of expression of genes with excellent spatial control. mRNA localization followed by localized translation appears to be a mechanism of targeted protein sorting to a specific cell‐compartment, which is linked to the establishment of cell polarity, cell asymmetry, embryonic axis determination, and neuronal plasticity in metazoans. However, the complexity of the mechanism and the components of mRNA localization in higher organisms prompted the use of the unicellular organism Saccharomyces cerevisiae as a simplified model organism to study this vital process. Current knowledge indicates that a variety of mRNAs are asymmetrically and selectively localized to the tip of the bud of the daughter cells, to the vicinity of endoplasmic reticulum, mitochondria, and nucleus in this organism, which are connected to diverse cellular processes. Interestingly, specific cis‐acting RNA localization elements (LEs) or RNA zip codes play a crucial role in the localization and trafficking of these localized mRNAs by providing critical binding sites for the specific RNA‐binding proteins (RBPs). In this review, we present a comprehensive account of mRNA localization in S. cerevisiae, various types of localization elements influencing the mRNA localization, and the RBPs, which bind to these LEs to implement a number of vital physiological processes. Finally, we emphasize the significance of this process by highlighting their connection to several neuropathological disorders and cancers.

This article is categorized under:

RNA Export and Localization > RNA Localization
Synthesis and Structure of Trimethylplatinum(IV) Iodide Complex of 4'‐(4‐Methoxyphenyl)‐2,2':6',2''‐terpyridine Ligand and its Halogen Bonding Property
Authors: Das Dipankar , Sutradhar Sourav , Rissanen Kari , Ghosh Biswa Nath
Published: February 2020

The synthesis and structural characterization of a new trimethylplatinum(IV) iodide complex of 4'‐(4‐methoxyphenyl)‐2,2':6',2''‐terpyridine ligand L, {PtMe3IL} (1) is reported. The X‐ray crystal structure shows that the terpyridine ligand L binds the platinum(IV) metal center in bidentate fashion, which is well supported by the 1H NMR spectrum of 1. The complex 1 upon crystallization with 1,4‐diiodotetrafluorobenzene (DITFB) forms the halogen bonded complex 1a (1·DITFB). The structural investigation shows that 1a exhibits the halogen bonding interaction in which the non‐coordinated pyridyl nitrogen acts as halogen bond acceptors by forming I···N interaction with iodine atom of DITFB. In addition iodine atom of complex 1 also acts as weak halogen bond acceptor.
Electronic Simulation of Neutronic Transient Studies for PWR‐900 MW(e)
Authors: Nagla Tarek F. , Abdel‐Rahman Mohamed A. E.
Published: February 2020

To study different functionalities of the PWR‐900 MW(e) reactor core, an electronic model of Simulation Program with Integrated Circuit Enfesied (PSPICE) for electronic circuit design was adopted to model the mathematical models. A classical breadboard electronically simulates the physical terminal characteristics of each network. The electronic simulator, parity simulator, for reactor core can simulate six‐delayed neutron groups, single prompt neutron, neutron source, fuel channel, the coolant, reactor poisons, temperature feedback, control rods, safety rods, and boron injection. Positive/negative step or sin reactivity functions are two case studies were analyzed. The obtained results were found to be in a good agreement with the available data of El‐Dabaa PWR 900 MW(e) basic simulator.
Educating for Environmental Citizenship in Non-formal Frameworks for Secondary Level Youth
Authors: Paraskeva-Hadjichambi Demetra , Goldman Daphne , Hadjichambis Andreas Ch. , Parra Gema , Lapin Katharina , Knippels Marie-Christine , Van Dam Frans
Published: February 2020

Non-formal education is an integral component to lifelong learning and its aim is for young people and adults to acquire and maintain the skills and competencies necessary to adapt to a continuously changing environment. Non-formal education implements different learning activities and is supplementary to formal education, taking place outside, but supplementary, to the formal educational system. From the conception and throughout the ongoing evolution of environmental education, non-formal education has been identified as an important framework for conducting Environmental Education and Education for Sustainability. Therefore, non-formal settings for secondary education level can contribute to Education for Environmental Citizenship by providing the opportunity and conditions that enable young people to acquire the body of knowledge as well as the skills, values, attitudes and pro-environmental actions necessary to become an Environmental Citizen. In addition, an Environmental Citizen is empowered and motivated to participate in society as an agent-of-change in the direction of solving contemporary environmental problems, preventing the creation of new ones, and achieving sustainability and restoring our (human) relationships with nature. Pedagogies including place-based education, civic ecology education, ecojustice pedagogy, action competence and socio-scientific inquiry-based learning can contribute to building students’ competencies for the deep civic participation necessary to realise environmental and social change. However, due to the novelty of the concept, the lack of a complete pedagogical framework for Education in Environmental Citizenship in non-formal settings presents a major challenge.
Environmental Citizenship and Youth Activism
Authors: Reis Pedro
Published: February 2020

A citizen’s capacity to act in society as an agent of change is an important element of Environmental Citizenship. This chapter discusses the concept of activism and the importance of activism initiatives in the development of citizens’ willingness and competences for critical, active and democratic engagement in preventing and solving environmental problems. Several possible ways for young people to get involved in environmental activism are presented. Also discussed is the possible and desirable combination of youth activism with citizen science, as a catalyst for empowering future citizens with the willingness and the higher-level abilities for participating in the global effort for a sustainable development and assuming the responsibility for future generations. Youth activism represents a key element in Education for Environmental Citizenship, allowing students to exercise their environmental rights and duties and to develop the knowledge, skills, values and attitudes that empower them as problem-solvers capable of facing the contemporary environmental problems.
Higgs vacuum (in)stability during inflation. The dangerous relevance of de Sitter departure and Planck-suppressed operators
Authors: Fumagalli Jacopo , Renaux-Petel Sébastien , Ronayne John W.
Published: February 2020

Abstract

The measured Standard Model parameters lie in a range such that the Higgs potential, once extrapolated up to high scales, develops a minimum of negative energy density. This has important cosmological implications. In particular, during inflation, quantum fluctuations could have pushed the Higgs field beyond its potential barrier, triggering the formation of anti-de Sitter regions, with fatal consequences for our universe. By requiring that this did not happen, one can in principle connect (and constrain) Standard Model parameters with the energy scale of inflation. In this context, we highlight the sensitivity of the fate of our vacuum to seemingly irrelevant physics. In particular, the departure of inflation from an exact de Sitter phase, as well as Planck-suppressed derivative operators, can, already and surprisingly, play a decisive role in (de)stabilizing the Higgs during inflation. Furthermore, in the stochastic dynamics, we quantify the impact of the amplitude of the noise differing from the one of a massless field, as well as of going beyond the slow-roll approximation by using a phase-space approach. On a general ground, our analysis shows that relating the period of inflation to precision particle physics requires a knowledge of these “irrelevant” effects.
Natural neutrino sector in a 331-model with Froggatt-Nielsen mechanism
Authors: Huitu Katri , Koivunen Niko , Kärkkäinen Timo J.
Published: February 2020

Abstract

The extensions of the Standard Model based on the SU(3)c × SU(3)L × U(1)X gauge group (331-models) have been advocated to explain the number of fermion families in nature. It has been recently shown that the Froggatt-Nielsen mechanism, a popular way to explain the mass hierarchy of the charged fermions, can be incorporated into the 331-setting in an economical fashion (FN331). In this work we extend the FN331-model to include three right-handed neutrino singlets. We show that the seesaw mechanism is realized in this model. The scale of the seesaw mechanism is near the SU(3)L × U(1)X-breaking scale. The model we present here simultaneously explains the mass hierarchy of all the fermions, including neutrinos, and the number of families.
Correction to: Photo-reactivity of dissolved organic carbon in the freshwater continuum
Authors: Panneer Selvam Balathandayuthabani , Lapierre Jean-François , Soares Ana R. A. , Bastviken David , Karlsson Jan , Berggren Martin
Published: February 2020

The original publication of this paper contains a mistake in Figure 3.
Demailly’s notion of algebraic hyperbolicity: geometricity, boundedness, moduli of maps
Authors: Javanpeykar Ariyan , Kamenova Ljudmila
Published: February 2020

Demailly’s conjecture, which is a consequence of the Green–Griffiths–Lang conjecture on varieties of general type, states that an algebraically hyperbolic complex projective variety is Kobayashi hyperbolic. Our aim is to provide evidence for Demailly’s conjecture by verifying several predictions it makes. We first define what an algebraically hyperbolic projective variety is, extending Demailly’s definition to (not necessarily smooth) projective varieties over an arbitrary algebraically closed field of characteristic zero, and we prove that this property is stable under extensions of algebraically closed fields. Furthermore, we show that the set of (not necessarily surjective) morphisms from a projective variety Y to a projective algebraically hyperbolic variety X that map a fixed closed subvariety of Y onto a fixed closed subvariety of X is finite. As an application, we obtain that $${{\,\mathrm{Aut}\,}}(X)$$

Aut

(
X
)

is finite and that every surjective endomorphism of X is an automorphism. Finally, we explore “weaker” notions of hyperbolicity related to boundedness of moduli spaces of maps, and verify similar predictions made by the Green–Griffiths–Lang conjecture on hyperbolic projective varieties.
A duality for Guichard nets
Authors: Szewieczek Gudrun
Published: February 2020

In this paper we study G-surfaces, a rather unknown surface class originally defined by Calapso, and show that the coordinate surfaces of a Guichard net are G-surfaces. Based on this observation, we present distinguished Combescure transformations that provide a duality for Guichard nets. Another class of special Combescure transformations is then used to construct a Bäcklund-type transformation for Guichard nets. In this realm a permutability theorem for the dual systems is proven.
The clinicopathological significance of the adipophilin and fatty acid synthase expression in salivary duct carcinoma
Authors: Hirai Hideaki , Tada Yuichiro , Nakaguro Masato , Kawakita Daisuke , Sato Yukiko , Shimura Tomotaka , Tsukahara Kiyoaki , Kano Satoshi , Ozawa Hiroyuki , Okami Kenji , Sato Yuichiro , Fushimi Chihiro , Shimizu Akira , Okamoto Isaku , Takase Soichiro , Okada Takuro , Sato Hiroki , Imanishi Yorihisa , Otsuka Kuninori , Watanabe Yoshihiro , Sakai Akihiro , Ebisumoto Koji , Togashi Takafumi , Ueki Yushi , Ota Hisayuki , Saigusa Natsuki , Takahashi Hideaki , Ando Mizuo , Urano Makoto , Hanazawa Toyoyuki , Nagao Toshitaka
Published: February 2020

Salivary duct carcinoma (SDC) is an aggressive, uncommon tumor histologically comparable to high-grade mammary ductal carcinoma. SDCs are usually androgen receptor (AR)–positive and often HER2-positive. Recently, therapies targeting these molecules for SDC have attracted attention. Lipid metabolism changes have been described in association with biological behavior in various cancers, although no such relationship has yet been reported for SDC. We therefore analyzed the clinicopathological relevance of the immunohistochemical expression of adipophilin (ADP) and fatty acid synthase (FASN), representative lipid metabolism–related proteins, in 147 SDCs. ADP and FASN were variably immunoreactive in most SDCs (both 99.3%), and the ADP and FASN expression was negatively correlated (P = 0.014). ADP-positive (≥ 5%) SDCs more frequently exhibited a prominent nuclear pleomorphism and high-Ki-67 labeling index than those ADP-negative (P = 0.013 and 0.011, respectively). In contrast, a high FASN score, calculated by the staining proportion and intensity, (≥ 120) was correlated with the high expression of AR and FOXA1 (P < 0.001 and = 0.003, respectively). The ADP and FASN expression differed significantly among the subtypes based on biomarker immunoprofiling, as assessed by the AR, HER2, and Ki-67 status (P = 0.017 and 0.003, respectively). A multivariate analysis showed that ADP-positive expression was associated with a shorter overall and progression-free survival (P = 0.018 and 0.003, respectively). ADP was associated with an aggressive histopathology and unfavorable prognosis, and FASN may biologically interact with the AR signaling pathway in SDC. ADP may, therefore, be a new prognostic indicator and therapeutic target in SDC.
Gas well integrity and methane migration: evaluation of published evidence during shale-gas development in the USA
Authors: Hammond Patrick A. , Wen Tao , Brantley Susan L. , Engelder Terry
Published: February 2020

More than 1 million wells may have been completed using hydraulic fracturing techniques in the USA alone; however, there have been few case studies exploring the impacts on water resources due to methane migration. This study evaluated the results of three investigations initiated by the US Environmental Protection Agency, that were subsequently described in published studies at Dimock in Pennsylvania, Parker-Hood County in Texas, and Pavillion in Wyoming, as well as another study completed at Sugar Run in northeast Pennsylvania. In addition, earlier investigations at Shaws Corner in Pennsylvania, Jackson County in West Virginia, Garfield County in Colorado, and Bainbridge in Ohio are summarized. The most common cause of incidents was the presence of uncemented sections of production casings in wells that allowed gas migration from intermediate depths to shallow freshwater aquifers. In three cases, an inadequate depth of the primary top of cement (TOC) also contributed to impacts. Sources of methane were best identified through analyses of isotopes on samples from production casings, annular spaces, and water wells. In Dimock, some isotope signatures changed with time, after the completion of remedial actions. In Parker-Hood County, where impacts were not related to gas well activity, noble gas analyses were also needed to determine the source of gas. At Pavillion, where maximum methane concentrations in water wells were <1 mg/L, no significant impacts were documented. For all the sites, most or all of the fugitive gas incidents may have been prevented by fully cementing production casings to the land surface.
Gap Functions and Error Bounds for Variational–Hemivariational Inequalities
Authors: Hung Nguyen Van , Migórski Stanislaw , Tam Vo Minh , Zeng Shengda
Published: February 2020

In this paper we investigate the gap functions and regularized gap functions for a class of variational–hemivariational inequalities of elliptic type. First, based on regularized gap functions introduced by Yamashita and Fukushima, we establish some regularized gap functions for the variational–hemivariational inequalities. Then, the global error bounds for such inequalities in terms of regularized gap functions are derived by using the properties of the Clarke generalized gradient. Finally, an application to a stationary nonsmooth semipermeability problem is given to illustrate our main results.