bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Farmer’s Choices for Climate Change Adaptation Practices in South-Western Uganda, 1980–2009
Authors: Zizinga Alex , Kangalawe Richard , Ainslie Andrew , Tenywa Moses , Majaliwa Jackson , Saronga Naome , Amoako Esther
Published: December 2017

Climate change is a serious threat to the livelihoods of rural communities, particularly in mountainous areas because they are very sensitive to such changes. In this study, we assessed the household determinants to climate change adaptation drawing from a case study of agricultural adaptation in the Mount Rwenzori area of South Western Uganda. The study identified the major adaptation practices that are adopted by farmers to cope with the impacts of climate change and using available on-farm technologies. A total of 143 smallholder farmers were sampled and interviewed using field based questionnaires, field observations, and key informant interviews. Data was cleaned, entered and analysed using SPSS and Stata software for descriptive statistics. Thereafter, a Multinomial logistic regression model was used to assess the drivers of farmers’ choice for adaptation practices, factors influencing the choice of adaptation, and barriers. The major adaptation practices that were identified included; use of different crop varieties, tree planting, soil and water conservation, early and late planting, and furrow irrigation. Discrete choice model results indicated the age of the household head, experience in farming, household size, climate change shocks, land size, use of agricultural inputs, landscape position (location), and crop yield varied significantly (p > 0.05), which influenced farmers’ choice of climate change adaptation practices. The main barriers to adaptation included inadequate information on adaptation methods and financial constraints, leading us to conclude that contextual adaptation practices are more desirable for adoption to farmers. Adapting to climate change needs support from government and other stakeholders, however the implementation is more successful when appropriate and suitable choices are employed.
Entropic Updating of Probabilities and Density Matrices
Authors: Vanslette Kevin
Published: December 2017

We find that the standard relative entropy and the Umegaki entropy are designed for the purpose of inferentially updating probabilities and density matrices, respectively. From the same set of inferentially guided design criteria, both of the previously stated entropies are derived in parallel. This formulates a quantum maximum entropy method for the purpose of inferring density matrices in the absence of complete information.
Phase Equilibria of the CH4-CO2 Binary and the CH4-CO2-H2O Ternary Mixtures in the Presence of a CO2-Rich Liquid Phase
Authors: Legoix Ludovic , Ruffine Livio , Donval Jean-Pierre , Haeckel Matthias
Published: December 2017

The knowledge of the phase behavior of carbon dioxide (CO2)-rich mixtures is a key factor to understand the chemistry and migration of natural volcanic CO2 seeps in the marine environment, as well as to develop engineering processes for CO2 sequestration coupled to methane (CH4) production from gas hydrate deposits. In both cases, it is important to gain insights into the interactions of the CO2-rich phase—liquid or gas—with the aqueous medium (H2O) in the pore space below the seafloor or in the ocean. Thus, the CH4-CO2 binary and CH4-CO2-H2O ternary mixtures were investigated at relevant pressure and temperature conditions. The solubility of CH4 in liquid CO2 (vapor-liquid equilibrium) was determined in laboratory experiments and then modelled with the Soave–Redlich–Kwong equation of state (EoS) consisting of an optimized binary interaction parameter kij(CH4-CO2) = 1.32 × 10−3 × T − 0.251 describing the non-ideality of the mixture. The hydrate-liquid-liquid equilibrium (HLLE) was measured in addition to the composition of the CO2-rich fluid phase in the presence of H2O. In contrast to the behavior in the presence of vapor, gas hydrates become more stable when increasing the CH4 content, and the relative proportion of CH4 to CO2 decreases in the CO2-rich phase after gas hydrate formation.
Hybrid Hydrogen and Mechanical Distributed Energy Storage
Authors: Ubertini Stefano , Facci Andrea Luigi , Andreassi Luca
Published: December 2017

Effective energy storage technologies represent one of the key elements to solving the growing challenges of electrical energy supply of the 21st century. Several energy storage systems are available, from ones that are technologically mature to others still at a research stage. Each technology has its inherent limitations that make its use economically or practically feasible only for specific applications. The present paper aims at integrating hydrogen generation into compressed air energy storage systems to avoid natural gas combustion or thermal energy storage. A proper design of such a hybrid storage system could provide high roundtrip efficiencies together with enhanced flexibility thanks to the possibility of providing additional energy outputs (heat, cooling, and hydrogen as a fuel), in a distributed energy storage framework. Such a system could be directly connected to the power grid at the distribution level to reduce power and energy intermittence problems related to renewable energy generation. Similarly, it could be located close to the user (e.g., office buildings, commercial centers, industrial plants, hospitals, etc.). Finally, it could be integrated in decentralized energy generation systems to reduce the peak electricity demand charges and energy costs, to increase power generation efficiency, to enhance the security of electrical energy supply, and to facilitate the market penetration of small renewable energy systems. Different configurations have been investigated (simple hybrid storage system, regenerate system, multistage system) demonstrating the compressed air and hydrogen storage systems effectiveness in improving energy source flexibility and efficiency, and possibly in reducing the costs of energy supply. Round-trip efficiency up to 65% can be easily reached. The analysis is conducted through a mixed theoretical-numerical approach, which allows the definition of the most relevant physical parameters affecting the system performance.
Fuzzy Logic Based MPPT Controller for a PV System
Authors: Robles Algarín Carlos , Taborda Giraldo John , Rodríguez Álvarez Omar
Published: December 2017

The output power of a photovoltaic (PV) module depends on the solar irradiance and the operating temperature; therefore, it is necessary to implement maximum power point tracking controllers (MPPT) to obtain the maximum power of a PV system regardless of variations in climatic conditions. The traditional solution for MPPT controllers is the perturbation and observation (P&O) algorithm, which presents oscillation problems around the operating point; the reason why improving the results obtained with this algorithm has become an important goal to reach for researchers. This paper presents the design and modeling of a fuzzy controller for tracking the maximum power point of a PV System. Matlab/Simulink (MathWorks, Natick, MA, USA) was used for the modeling of the components of a 65 W PV system: PV module, buck converter and fuzzy controller; highlighting as main novelty the use of a mathematical model for the PV module, which, unlike diode based models, only needs to calculate the curve fitting parameter. A P&O controller to compare the results obtained with the fuzzy control was designed. The simulation results demonstrated the superiority of the fuzzy controller in terms of settling time, power loss and oscillations at the operating point.
Improving an Integer Linear Programming Model of an Ecovat Buffer by Adding Long-Term Planning
Authors: Goeijen Gijs , Smit Gerard , Hurink Johann
Published: December 2017

The Ecovat is a seasonal thermal storage solution consisting of a large underground water tank divided into a number of virtual segments that can be individually charged and discharged. The goal of the Ecovat is to supply heat demand to a neighborhood throughout the entire year. In this work, we extend an integer linear programming model to describe the charging and discharging of such an Ecovat buffer by adding a long-term (yearly) planning step to the model. We compare the results from the model using this extension to previously obtained results and show significant improvements when looking at the combination of costs and the energy content of the buffer at the end of the optimization. Furthermore, we show that the model is very robust against prediction errors. For this, we compare two different cases: one case in which we assume perfect predictions are available and one case in which we assume no predictions are available. The largest observed difference in costs between these two cases is less than 2%.
New Performance Indices for Voltage Stability Analysis in a Power System
Authors: Adebayo Isaiah , Sun Yanxia
Published: December 2017

The frequent occurrence of voltage instability in a modern power system is alarming and thus, has been of great concern to power system utilities. In this paper, a new performance index based on the power flow solutions for voltage stability assessment of a power system is presented. First, the voltage deviation with respect to reactive power load variation at each load bus is found. Thereafter, the performance voltage bus index for each load bus is computed. An improved modal analysis technique (IMAT) is used to identify weak nodes that are liable to voltage instability in a power system. This technique uses a submatrix of the full Jacobian matrix for voltage stability analysis. Comparison of the proposed method is done with existing voltage stability indices and the conventional modal analysis technique (CMAT). The effectiveness of all the approaches presented are tested on both Western system coordinating Council (WSCC) 9-bus, IEEE 30 bus and IEEE 57 bus test systems. Results obtained show that the proposed techniques can serve as an alternative tool to other conventional techniques for voltage stability assessment in a power system and can be of tremendous benefits in the planning and operation of a power system by system operators.
An Improved Continuous-Time Model Predictive Control of Permanent Magnetic Synchronous Motors for a Wide-Speed Range
Authors: Su Dandan , Zhang Chengning , Dong Yugang
Published: December 2017

This paper proposes an improved continuous-time model predictive control (CTMPC) of permanent magnetic synchronous motors (PMSMs) for a wide-speed range, including the constant torque region and the flux-weakening (FW) region. In the constant torque region, the mathematic models of PMSMs in dq-axes are decoupled without the limitation of DC-link voltage. However, in the FW region, the mathematic models of PMSMs in dq-axes are cross-coupled together with the limitation of DC-link voltage. A nonlinear PMSMs mathematic model in the FW region is presented based on the voltage angle. The solving of the nonlinear mathematic model of PMSMs in FW region will lead to heavy computation load for digital signal processing (DSP). To overcome such a problem, a linearization method of the voltage angle is also proposed to reduce the computation load. The selection of transiting points between the constant torque region and FW regions is researched to improve the performance of the driven system. Compared with the proportional integral (PI) controller, the proposed CTMPC has obvious advantages in dealing with systems’ nonlinear constraints and improving system performance by restraining overshoot current under step torque changing. Both simulation and experimental results confirm the effectiveness of the proposed method in achieving good steady-state performance and smooth switching between the constant torque and FW regions.
Predicted Release and Analysis of Novel ACE-I, Renin, and DPP-IV Inhibitory Peptides from Common Oat (Avena sativa) Protein Hydrolysates Using in Silico Analysis
Authors: Bleakley Stephen , Hayes Maria , O’ Shea Nora , Gallagher Eimear , Lafarga Tomas
Published: December 2017

The renin-angiotensin-aldosterone system (RAAS) plays an important role in regulating hypertension by controlling vasoconstriction and intravascular fluid volume. RAAS itself is largely regulated by the actions of renin (EC 3.4.23.15) and the angiotensin-I-converting enzyme (ACE-I; EC 3.4.15.1). The enzyme dipeptidyl peptidase-IV (DPP-IV; EC 3.4.14.5) also plays a role in the development of type-2 diabetes. The inhibition of the renin, ACE-I, and DPP-IV enzymes has therefore become a key therapeutic target for the treatment of hypertension and diabetes. The aim of this study was to assess the bioactivity of different oat (Avena sativa) protein isolates and their ability to inhibit the renin, ACE-I, and DPP-IV enzymes. In silico analysis was carried out to predictthe likelihood of bioactive inhibitory peptides occurring from oat protein hydrolysates following in silico hydrolysis with the proteases papain and ficin. Nine peptides, including FFG, IFFFL, PFL, WWK, WCY, FPIL, CPA, FLLA, and FEPL were subsequently chemically synthesised, and their bioactivities were confirmed using in vitro bioassays. The isolated oat proteins derived from seven different oat varieties were found to inhibit the ACE-I enzyme by between 86.5 ± 10.7% and 96.5 ± 25.8%, renin by between 40.5 ± 21.5% and 70.9 ± 7.6%, and DPP-IV by between 3.7 ± 3.9% and 46.2 ± 28.8%. The activity of the synthesised peptides was also determined.
Accumulation of De-Icing Salt and Leaching in Spanish Soils Surrounding Roadways
Authors: Asensio Esther , Ferreira Víctor J. , Gil Gonzalo , García-Armingol Tatiana , López-Sabirón Ana M. , Ferreira Germán
Published: December 2017

The environmental implications of soil salinity caused by accumulation of de-icing salt and leaching in soils of northeastern Spain were examined. For this purpose, the concentrations of ions associated with diagnosing and managing this problem were evaluated from several measurements performed over one year along a road. This analysis demonstrated a higher concentration of soluble Na+ in the soil 3 m from a road in the northernmost part of the study area in February, which made the soil saline-sodic. Data from the rest of the study period (during the spring and summer) demonstrated that the de-icing salt moved to areas farther south by runoff water, which caused environmental impacts by modifying soil characteristics. These results suggest that leaching of Ca2+ and Mg2+ cations occurred faster in the studied systems in sodic soils. Leaching of these cations may affect plant yield, and results in environmental impacts within 3–30 m from the road. Awareness of this impact will be useful for developing future strategies for evaluating and reporting these complex relationships within Spain’s transport system and environment.
The Synergetic Effect of Cash Transfers for Families, Child Sensitive Social Protection Programs, and Capacity Building for Effective Social Protection on Children’s Nutritional Status in Nepal
Authors: Renzaho Andre , Chitekwe Stanley , Chen Wen , Rijal Sanjay , Dhakal Thakur , Dahal Pradiumna
Published: December 2017

Objective: The aim of this study was to evaluate the effectiveness of the synergetic effect of child sensitive social protection programs, augmented by a capacity building for social protection and embedded within existing government’s targeted resource transfers for families on child nutritional status. Design: A repeat cross-sectional quasi-experimental design with measures taken pre- (October–December 2009) and post- (December 2014–February 2015) intervention in the intervention and comparison district. The comparison district received standard social welfare services in the form of targeted resource transfers (TRTs) for eligible families. The intervention district received the TRTs plus a child cash payment, augmented by a capacity building for effective social protection outcomes. Propensity scores were used in difference-in-differences models to compare the changes over time between the intervention and control groups. Results: Propensity score matched/weighted models produced better results than the unmatched analyses, and hence we report findings from the radius matching. The intervention resulted in a 5.16 (95% CI: 9.55, 0.77), 7.35 (95% CI: 11.62, 3.08) and 2.84 (95% CI: 5.58, 0.10) percentage point reduction in the prevalence of stunting, underweight, and wasting among children under the age, respectively. The intervention impact was greater in boys than girls for stunting and wasting; and greater in girls than boys for underweight. The intervention also resulted in a 6.66 (95% CI: 2.13, 3.18), 11.40 (95% CI: 16.66, 6.13), and 4.0 (95% CI: 6.43, 1.78) percentage point reduction in the prevalence of stunting, underweight, and wasting among older children (≥24 months). No impact was observed among younger children (<24 months). Conclusions: Targeted resource transfers for families, augmented with a child sensitive social protection program and capacity building for social protection can address effectively child malnutrition. To increase the intervention effectiveness on younger children, the child cash payment amount needs to be revisited and closely embedded into infant and young child feeding initiatives, but also adjusted to equate to 20% of household expenditure or more to maximize the diversity of food available to young children.
Low Levels of Physical Activity and Sedentary Behavior in Adults with Intellectual Disabilities
Authors: Hsieh Kelly , Hilgenkamp Thessa , Murthy Sumithra , Heller Tamar , Rimmer James
Published: December 2017

Adults with intellectual disabilities (ID) are more likely to lead sedentary lifestyles and have low levels of physical activity (LLPA). The present study investigated the prevalence of reported LLPA and time spent watching TV in adults with ID and identified the associated factors for these behaviors. The proxy informants of 1618 adults with ID completed the surveys regarding their health behaviors. Multiple logistic regressions were employed for LLPA and multiple linear regressions for time spent watching TV. About 60% of adults with ID had LLPA and average time spent watching TV was 3.4 h a day. Some characteristics and health and function variables were identified as associated factors. While engaging in community activities and involvement in Special Olympics were inversely associated with LLPA, they were not associated with time spent watching TV. Attending day/educational programs or being employed were associated with spending less time watching TV. Findings highlight differential factors associated with LLPA versus TV-watching behavior in adults with ID. Hence, a key strategy aimed at increasing physical activity includes promoting participation in social and community activities, while targeted activities for reducing sedentary behavior might focus on providing day programs or employment opportunities for adults with ID.
Microbial and Plant-Assisted Bioremediation of Heavy Metal Polluted Environments: A Review
Authors: Ojuederie Omena , Babalola Olubukola
Published: December 2017

Environmental pollution from hazardous waste materials, organic pollutants and heavy metals, has adversely affected the natural ecosystem to the detriment of man. These pollutants arise from anthropogenic sources as well as natural disasters such as hurricanes and volcanic eruptions. Toxic metals could accumulate in agricultural soils and get into the food chain, thereby becoming a major threat to food security. Conventional and physical methods are expensive and not effective in areas with low metal toxicity. Bioremediation is therefore an eco-friendly and efficient method of reclaiming environments contaminated with heavy metals by making use of the inherent biological mechanisms of microorganisms and plants to eradicate hazardous contaminants. This review discusses the toxic effects of heavy metal pollution and the mechanisms used by microbes and plants for environmental remediation. It also emphasized the importance of modern biotechnological techniques and approaches in improving the ability of microbial enzymes to effectively degrade heavy metals at a faster rate, highlighting recent advances in microbial bioremediation and phytoremediation for the removal of heavy metals from the environment as well as future prospects and limitations. However, strict adherence to biosafety regulations must be followed in the use of biotechnological methods to ensure safety of the environment.
Influence of the Grinding Wheel Topography on the Thermo-Mechanical Stress Collective in Grinding
Authors: Barth Sebastian , Klocke Fritz
Published: December 2017

The grinding process is used for both high-performance machining and surface finishing of hardened steel. In addition to the grinding parameters and the grinding fluid supply, the topography of the grinding wheel mainly determines the grinding process behavior and the grinding process result. An alteration of the topography by a variation of the volumetric composition of the grinding wheel, by a variation of the grinding wheel conditioning, or by wear causes a change in the contact conditions. The state of the art shows a substantial knowledge deficit about the influence of the volumetric grinding wheel composition and the resulting grinding wheel topography on the thermo-mechanical stress collective acting on the workpiece external zone. Thus, it is not possible to make a quantitative statement about the influence of the volumetric grinding wheel composition on the external zone properties of a component after grinding. Therefore, the aim of the current research is an empirical-analytical model for the prediction of the thermo-mechanical stress collective as a function of the grinding wheel topography. For this purpose, a methodology is developed, which enables the prediction of the topography-dependent thermo-mechanical load in a grinding process. Therefore, the topography is characterized by means of quantitative parameters and the main influencing variables on the grinding process behavior are investigated. The findings are used to analyze the influence of a change in the topography on the grinding temperature and the grinding force. The obtained results are summarized and are used to explain the thermo-mechanical stress collective as a function of the grinding wheel topography.
Olive Plantation Mapping on a Sub-Tree Scale with Object-Based Image Analysis of Multispectral UAV Data; Operational Potential in Tree Stress Monitoring
Authors: Karydas Christos , Gewehr Sandra , Iatrou Miltiadis , Iatrou George , Mourelatos Spiros
Published: December 2017

The objective of this study was to develop a methodology for mapping olive plantations on a sub-tree scale. For this purpose, multispectral imagery of an almost 60-ha plantation in Greece was acquired with an Unmanned Aerial Vehicle. Objects smaller than the tree crown were produced with image segmentation. Three image features were indicated as optimum for discriminating olive trees from other objects in the plantation, in a rule-based classification algorithm. After limited manual corrections, the final output was validated by an overall accuracy of 93%. The overall processing chain can be considered as suitable for operational olive tree monitoring for potential stresses.
Study on the Ingredient Proportions and After-Treatment of Laser Sintering Walnut Shell Composites
Authors: Yu Yueqiang , Guo Yanling , Jiang Ting , Li Jian , Jiang Kaiyi , Zhang Hui
Published: December 2017

To alleviate resource shortage, reduce the cost of materials consumption and the pollution of agricultural and forestry waste, walnut shell composites (WSPC) consisting of walnut shell as additive and copolyester hot melt adhesive (Co-PES) as binder was developed as the feedstock of selective laser sintering (SLS). WSPC parts with different ingredient proportions were fabricated by SLS and processed through after-treatment technology. The density, mechanical properties and surface quality of WSPC parts before and after post processing were analyzed via formula method, mechanical test and scanning electron microscopy (SEM), respectively. Results show that, when the volume fraction of the walnut shell powder in the WSPC reaches the maximum (40%), sintered WSPC parts have the smallest warping deformation and the highest dimension precision, although the surface quality, density, and mechanical properties are low. However, performing permeating resin as the after-treatment technology could considerably increase the tensile, bending and impact strength by 496%, 464%, and 516%, respectively.
Effect of Anisotropy on the Resilient Behaviour of a Granular Material in Low Traffic Pavement
Authors: Jing Peng , Nowamooz Hossein , Chazallon Cyrille
Published: December 2017

Granular materials are often used in pavement structures. The influence of anisotropy on the mechanical behaviour of granular materials is very important. The coupled effects of water content and fine content usually lead to more complex anisotropic behaviour. With a repeated load triaxial test (RLTT), it is possible to measure the anisotropic deformation behaviour of granular materials. This article initially presents an experimental study of the resilient repeated load response of a compacted clayey natural sand with three fine contents and different water contents. Based on anisotropic behaviour, the non-linear resilient model (Boyce model) is improved by the radial anisotropy coefficient γ3 instead of the axial anisotropy coefficient γ1. The results from both approaches (γ1 and γ3) are compared with the measured volumetric and deviatoric responses. These results confirm the capacity of the improved model to capture the general trend of the experiments. Finally, finite element calculations are performed with CAST3M in order to validate the improvement of the modified Boyce model (from γ1 to γ3). The modelling results indicate that the modified Boyce model with γ3 is more widely available in different water contents and different fine contents for this granular material. Besides, based on the results, the coupled effects of water content and fine content on the deflection of the structures can also be observed.
Thymoquinone Inhibits the Migration and Invasive Characteristics of Cervical Cancer Cells SiHa and CaSki In Vitro by Targeting Epithelial to Mesenchymal Transition Associated Transcription Factors Twist1 and Zeb1
Authors: Li Jun , Khan Md. , Wei Chunli , Cheng Jingliang , Chen Hanchun , Yang Lisha , Ijaz Iqra , Fu Junjiang
Published: December 2017

Cervical cancer is one of the most common gynecological malignant tumors worldwide, for which chemotherapeutic strategies are limited due to their non-specific cytotoxicity and drug resistance. The natural product thymoquinone (TQ) has been reported to target a vast number of signaling pathways in carcinogenesis in different cancers, and hence is regarded as a promising anticancer molecule. Inhibition of epithelial to mesenchymal transition (EMT) regulators is an important approach in anticancer research. In this study, TQ was used to treat the cervical cancer cell lines SiHa and CaSki to investigate its effects on EMT-regulatory proteins and cancer metastasis. Our results showed that TQ has time-dependent and dose-dependent cytotoxic effects, and it also inhibits the migration and invasion processes in different cervical cancer cells. At the molecular level, TQ treatment inhibited the expression of Twist1, Zeb1 expression, and increased E-Cadherin expression. Luciferase reporter assay showed that TQ decreases the Twist1 and Zeb1 promoter activities respectively, indicating that Twist1 and Zeb1 might be the direct target of TQ. TQ also increased cellular apoptosis in some extent, but apoptotic genes/proteins we tested were not significant affected. We conclude that TQ inhibits the migration and invasion of cervical cancer cells, probably via Twist1/E-Cadherin/EMT or/and Zeb1/E-Cadherin/EMT, among other signaling pathways.
Improving the Catalytic Property of the Glycoside Hydrolase LXYL-P1–2 by Directed Evolution
Authors: Chen Jing-Jing , Liang Xiao , Li Hui-Xian , Chen Tian-Jiao , Zhu Ping
Published: December 2017

The glycoside hydrolase LXYL-P1–2 from Lentinula edodes can specifically hydrolyze 7-β-xylosyltaxanes to form 7-β-hydroxyltaxanes for the semi-synthesis of paclitaxel. In order to improve the catalytic properties of the enzyme, we performed error-prone PCR to construct the random mutant library of LXYL-P1–2 and used the methanol-induced plate method to screen the mutants with improved catalytic properties. Two variants, LXYL-P1–2-EP1 (EP1, S91D mutation) and LXYL-P1–2-EP2 (EP2, T368E mutation), were obtained from the library and exhibited 17% and 47% increases in their catalytic efficiencies on 7-β-xylosyl-10-deacetyltaxol. Meanwhile, compared with LXYL-P1–2, EP1 and EP2 showed elevated stabilities in the range of pH ≥ 6 conditions. After treatment at pH 12 for 48 h, EP1 and EP2 retained 77% and 63% activities, respectively, while the wild-type only retained 33% activity under the same condition. Molecular docking results revealed that the S91D mutation led to a shorter distance between the R-chain and the substrate, while the T368E mutation increased negative charge at the surface of the enzyme, and may introduce alterations of the loop near the active pocket, both of which may result in improved stabilities and catalytic activities of enzymes. This study provides a practical directed evolution method for exploring catalytically improved glycoside hydrolase.
Using the SPE and Micro-HPLC-MS/MS Method for the Analysis of Betalains in Rat Plasma after Red Beet Administration
Authors: Sawicki Tomasz , Juśkiewicz Jerzy , Wiczkowski Wiesław
Published: December 2017

The objective of this study was to develop a simple and reproducible method for the qualitative and quantitative analysis of betalains in plasma samples, based on Solid Phase Extraction (SPE) and micro-high performance liquid chromatography coupled with mass spectrometry (micro-HPLC-MS/MS). The eight betalain compounds detected and quantified were characterized in the fortified rat blood plasma samples. The developed method showed a good coefficient of determination (R2 = 0.999), good recovery, precision, and appropriate limits of detection (LOD) and quantification (LOQ) for these compounds. Application of this method for the treatment of rat plasma samples collected after the betalain preparation administration, for the first time, revealed the presence of native betalains and their metabolites in plasma samples. Moreover, among them, betanin (2.14 ± 0.06 µmol/L) and isobetanin (3.28 ± 0.04 µmol/L) were found at the highest concentration. The results indicated that the combination of an SPE method with a micro-HPLC-MS/MS analysis may be successfully applied for the determination of betalains in the blood plasma.
Synthesis of Novel Nitrogen-Containing Heterocycle Bromophenols and Their Interaction with Keap1 Protein by Molecular Docking
Authors: Feng Xiu E. , Wang Qin Jin , Gao Jie , Ban Shu Rong , Li Qing Shan
Published: December 2017

We previously reported 5,2’-dibromo-2,4’,5’-trihydroxydiphenylmethanoe (LM49), a bromophenol analogue that shows strong protection from oxidative stress injury owing to its superior anti-inflammatory, antioxidant, and anti-apoptotic properties. A series of novel nitrogen-containing heterocycle bromophenols were herein synthesized by introducing substituted piperidine, piperazine, and imidazole to modify 2-position of the lead compound LM49. By further evaluating their cytoprotective activity against H2O2 induced injury in EA.hy926 cells, 14 target bromophenols showed moderate-to-potent activity with EC50 values in the range of 0.9–6.3 μM, which were stronger than that of quercetin (EC50: 18.0 μM), a positive reference compound. Of these, the most potent compound 22b is a piperazine bromophenol with an EC50 value of 0.9 μM equivalent to the LM49. Molecular docking studies were subsequently performed to deduce the affinity and binding mode of derived halophenols toward the Keap1 Kelch domain, the docking results exhibited that the small molecule 22b is well accommodated by the bound region of Keap1-Kelch and Nrf2 through stable hydrogen bonds and hydrophobic interaction, which contributed to the enhancement of affinity and stability between the ligand and receptor. The above facts suggest that 22b is a promising pharmacological candidate for further cardiovascular drug development. Moreover, the targeting Keap1-Nrf2 protein-protein interaction may be an emerging strategy for halophenols to selectively and effectively activate Nrf2 triggering downstream protective genes defending against injury.
Comprehensive Profiling and Quantification of Ginsenosides in the Root, Stem, Leaf, and Berry of Panax ginseng by UPLC-QTOF/MS
Authors: Lee Jae Won , Choi Bo-Ram , Kim Young-Chang , Choi Doo Jin , Lee Young-Seob , Kim Geum-Soog , Baek Nam-In , Kim Seung-Yu , Lee Dae Young
Published: December 2017

The effective production and usage of ginsenosides, given their distinct pharmacological effects, are receiving increasing amounts of attention. As the ginsenosides content differs in different parts of Panax ginseng, we wanted to assess and compare the ginsenosides content in the ginseng roots, leave, stems, and berries. To extract the ginsenosides, 70% (v/v) methanol was used. The optimal ultra-performance liquid chromatography-quadrupole time of flight mass spectrometry (UPLC-QTOF/MS) method was used to profile various ginsenosides from the different parts of P. ginseng. The datasets were then subjected to multivariate analysis including principal component analysis (PCA) and hierarchical clustering analysis (HCA). A UPLC-QTOF/MS method with an in-house library was constructed to profile 58 ginsenosides. With this method, a total of 39 ginsenosides were successfully identified and quantified in the ginseng roots, leave, stem, and berries. PCA and HCA characterized the different ginsenosides compositions from the different parts. The quantitative ginsenoside contents were also characterized from each plant part. The results of this study indicate that the UPLC-QTOF/MS method can be an effective tool to characterize various ginsenosides from the different parts of P. ginseng.
A Combined Approach of Sensor Data Fusion and Multivariate Geostatistics for Delineation of Homogeneous Zones in an Agricultural Field
Authors: Castrignanò Annamaria , Buttafuoco Gabriele , Quarto Ruggiero , Vitti Carolina , Langella Giuliano , Terribile Fabio , Venezia Accursio
Published: December 2017

To assess spatial variability at the very fine scale required by Precision Agriculture, different proximal and remote sensors have been used. They provide large amounts and different types of data which need to be combined. An integrated approach, using multivariate geostatistical data-fusion techniques and multi-source geophysical sensor data to determine simple summary scale-dependent indices, is described here. These indices can be used to delineate management zones to be submitted to differential management. Such a data fusion approach with geophysical sensors was applied in a soil of an agronomic field cropped with tomato. The synthetic regionalized factors determined, contributed to split the 3D edaphic environment into two main horizontal structures with different hydraulic properties and to disclose two main horizons in the 0–1.0-m depth with a discontinuity probably occurring between 0.40 m and 0.70 m. Comparing this partition with the soil properties measured with a shallow sampling, it was possible to verify the coherence in the topsoil between the dielectric properties and other properties more directly related to agronomic management. These results confirm the advantages of using proximal sensing as a preliminary step in the application of site-specific management. Combining disparate spatial data (data fusion) is not at all a naive problem and novel and powerful methods need to be developed.
Zinc Ameliorate Oxidative Stress and Hormonal Disturbance Induced by Methomyl, Abamectin, and Their Mixture in Male Rats
Authors: Mansour Sameeh A. , Abbassy Mostafa A. , Shaldam Hassan A.
Published: December 2017

Exposure to mixtures of toxicants (e.g., pesticides) is common in real life and a subject of current concern. The present investigation was undertaken to assess some toxicological effects in male rats following exposure to methomyl (MET), abamectin (ABM), and their combination (MET+ABM), and to evaluate the ameliorative effect of zinc co-administration. Three groups of rats were designated for MET, ABM, and the mixture treatments. Three other groups were designated for zinc in conjunction with the pesticides. Additionally, one group received water only (control), and the other represented a positive zinc treatment. The obtained results revealed that MET was acutely more toxic than ABM. The tested pesticides induced significant elevation in lipid peroxidation and catalase levels, while declined the levels of the other tested parameters e.g., Superoxide dismutase (SOD), Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Glutathione reductase (GR), Cytochrome P450 (CYP450), testosterone, and thyroxine). Biochemical alterations induced by the mixture were greater than those recorded for each of the individual insecticides. The joint action analysis, based on the obtained biochemical data, revealed the dominance of antagonistic action among MET and ABM. Zinc supplementation achieved noticeable ameliorative effects. It was concluded that zinc may act as a powerful antioxidant, especially in individuals who are occupationally exposed daily to low doses of such pesticides.
What contributes to an effective mannose recognition domain?
Authors: Sager Christoph P , Eriş Deniz , Smieško Martin , Hevey Rachel , Ernst Beat
Published: December 2017

In general, carbohydrate–lectin interactions are characterized by high specificity but also low affinity. The main reason for the low affinities are desolvation costs, due to the numerous hydroxy groups present on the ligand, together with the typically polar surface of the binding sites. Nonetheless, nature has evolved strategies to overcome this hurdle, most prominently in relation to carbohydrate–lectin interactions of the innate immune system but also in bacterial adhesion, a process key for the bacterium’s survival. In an effort to better understand the particular characteristics, which contribute to a successful carbohydrate recognition domain, the mannose-binding sites of six C-type lectins and of three bacterial adhesins were analyzed. One important finding is that the high enthalpic penalties caused by desolvation can only be compensated for by the number and quality of hydrogen bonds formed by each of the polar hydroxy groups engaged in the binding process. In addition, since mammalian mannose-binding sites are in general flat and solvent exposed, the half-lives of carbohydrate–lectin complexes are rather short since water molecules can easily access and displace the ligand from the binding site. In contrast, the bacterial lectin FimH benefits from a deep mannose-binding site, leading to a substantial improvement in the off-rate. Together with both a catch-bond mechanism (i.e., improvement of affinity under shear stress) and multivalency, two methods commonly utilized by pathogens, the affinity of the carbohydrate–FimH interaction can be further improved. Including those just described, the various approaches explored by nature to optimize selectivity and affinity of carbohydrate–lectin interactions offer interesting therapeutic perspectives for the development of carbohydrate-based drugs.
The Constant Average Relationship between Dust-obscured Star Formation and Stellar Mass from z = 0 to z = 2.5
Authors: Whitaker Katherine E. , Pope Alexandra , Cybulski Ryan , Casey Caitlin M. , Popping Gergö , Yun Min S.
Published: December 2017

The total star formation budget of galaxies consists of the sum of the unobscured star formation, as observed in the rest-frame ultraviolet (UV), together with the obscured component that is absorbed and re-radiated by dust grains in the infrared. We explore how the fraction of obscured star formation depends on stellar mass for mass-complete samples of galaxies at

. We combine GALEX and WISE photometry for SDSS-selected galaxies with the 3D-HST treasury program and Spitzer/MIPS 24 μm photometry in the well-studied five extragalactic Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) fields. We find a strong dependence of the fraction of obscured star formation (f
obscured = SFRIR/SFRUV+IR) on stellar mass, with remarkably little evolution in this fraction with redshift out to z = 2.5. 50% of star formation is obscured for galaxies with log(M/M
⊙) = 9.4; although unobscured star formation dominates the budget at lower masses, there exists a tail of low-mass, extremely obscured star-forming galaxies at

. For log(M/M
⊙) > 10.5, >90% of star formation is obscured at all redshifts. We also show that at fixed total SFR,

is lower at higher redshift. At fixed mass, high-redshift galaxies are observed to have more compact sizes and much higher star formation rates, gas fractions, and hence surface densities (implying higher dust obscuration), yet we observe no redshift evolution in

with stellar mass. This poses a challenge to theoretical models, where the observed compact sizes at high redshift seem in tension with lower dust obscuration.
Action Dynamics of the Local Supercluster
Authors: Shaya Edward J. , Tully R. Brent , Hoffman Yehuda , Pomarède Daniel
Published: December 2017

The fully nonlinear gravitationally induced trajectories of a nearly complete set of galaxies, groups, and clusters in the Local Supercluster are constructed in a numerical action method model constrained by data from the CosmicFlows survey and various distance indicators. We add the gravity field due to inhomogeneities external to the sample sphere by making use of larger-scale peculiar flow measurements. Assignments of total masses were made to find the best overall set of mutual attractions, as determined by a goodness criterion based on present-day radial velocities, individually for the Virgo Cluster, M31, and the Milky Way (MW), and via a mass-to-light ratio relationship for other masses. The low median chi-square found indicates that the model fits the present-day velocity flow well, but a slightly high mean chi-square may indicate that some masses underwent complex orbits. The best fit, when setting the value of H
0 to the CosmicFlows value of 75 km s−1 Mpc−1 and the WMAP value for Ω
m
 = 0.244 consistent with that H
0, occurs with the following parameters: Ωorphan = 0.077 ± 0.016,

(L
10 is the K-band luminosity in units of 1010
L
☉), a Virgo mass of 6.3 ± 0.8 × 1014
M
☉ (M/L

K
= 113 ± 15 M
☉/L
☉), and a mass for the MW plus M31 of 5.15 ± 0.35 × 1012
M
☉. The best constant mass-to-light ratio is M/L

K
 = 58 ± 3 M
☉/L
☉. The Virgocentric turnaround radius is 7.3 ± 0.3 Mpc. We explain several interesting trends in peculiar motions for various regions now that we can construct the 3D orbital histories.
The Hard X-Ray Emission of the Blazar PKS 2155–304
Authors: Gaur Haritma , Chen Liang , Misra R. , Sahayanathan S. , Gu M. F. , Kushwaha P. , Dewangan G. C.
Published: December 2017

The synchrotron peak of the X-ray bright High Energy Peaked Blazar PKS 2155–304 occurs in the UV-EUV region and hence its X-ray emission (0.6–10 keV) lies mostly in the falling part of the synchrotron hump. We aim to study the X-ray emission of PKS 2155–304 during different intensity states in 2009–2014 using the XMM-Newton satellite. We studied the spectral curvature of all of the observations to provide crucial information on the energy distribution of the nonthermal particles. Most of the observations show curvature or deviation from a single power law and can be well modeled by a log parabola model. In some of the observations, we find spectral flattening after 6 keV. In order to find the possible origin of the X-ray excess, we built the Multiband Spectral Energy distribution. We find that the X-ray excess in PKS 2155–304 is difficult to fit in the one zone model but, could be easily reconciled in the spine/layer jet structure. The hard X-ray excess can be explained by the inverse Comptonization of the synchrotron photons (from the layer) by the spine electrons.
Direct Observations of Different Sunspot Waves Influenced by Umbral Flashes
Authors: Sharma Aishawnnya , Gupta G. R. , Tripathi Durgesh , Kashyap V. , Pathak Amit
Published: December 2017

We report the simultaneous presence of chromospheric umbral flashes and associated umbral waves, and propagating coronal disturbances, in a sunspot and related active region. We have analyzed time–distance maps obtained using the observations from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. These maps show the simultaneous occurrence of different sunspot oscillations and waves such as umbral flashes, umbral waves, and coronal waves. Analysis of the original light curves, i.e., without implementing any Fourier filtering on them, shows that the amplitudes of different sunspot waves observed at different atmospheric layers change in synchronization with the light curves obtained from the umbral flash region, thus demonstrating that these oscillations are modulated by umbral flashes. This study provides the first observational evidence of the influence of sunspot oscillations within the umbra on other sunspot waves extending up to the corona. The properties of these waves and oscillations can be utilized to study the inherent magnetic coupling among different layers of the solar atmosphere above sunspots.
The Formation of Super-Earths by Tidally Forced Turbulence
Authors: Yu Cong
Published: December 2017

The Kepler observations indicate that many exoplanets are super-Earths, which brings about a puzzle for the core-accretion scenario. Since observed super-Earths are in the range of critical mass, they accrete gas efficiently and become gas giants. Theoretically, super-Earths are predicted to be rare in the core-accretion framework. To resolve this contradiction, we propose that the tidally forced turbulent diffusion may affect the heat transport inside the planet. Thermal feedback induced by turbulent diffusion is investigated. We find that the tidally forced turbulence generates pseudo-adiabatic regions within radiative zones, which pushes the radiative-convective boundaries inward. This decreases the cooling luminosity and enhances the Kelvin–Helmholtz (KH) timescale. For a given lifetime of protoplanetary disks (PPDs), there exists a critical threshold for the turbulent diffusivity, ν
critical. If ν
turb > ν
critical, the KH timescale is longer than the disk lifetime and the planet becomes a super-Earth, rather than a gas giant. We find that even a small value of turbulent diffusion has influential effects on the evolution of super-Earths. The ν
critical increases with the core mass. We further ascertain that, within the minimum-mass extrasolar nebula, ν
critical increases with the semimajor axis. This may explain the feature that super-Earths are common in inner PPD regions, while gas giants are common in outer PPD regions. The predicted envelope mass fraction is not fully consistent with observations. We discuss physical processes, such as late core assembly and mass-loss mechanisms, that may be operating during super-Earth formation.