bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Saliency Aggregation-Based Approach for Insulator Flashover Fault Detection Using Aerial Images
Authors: Zhai Yongjie , Cheng Haiyan , Chen Rui , Yang Qiang , Li Xiaoxia
Published: February 2018

Accurate and timely detection of insulator flashover on power transmission lines is of paramount importance to power utilities. Most available solutions mainly focus on the exploitation of the flashover mechanism or the discharge area detection, rather than the identification of a damaged area due to flashovers using captured aerial images. To this end, this paper proposes a multi-saliency aggregation-based porcelain insulator flashover fault detection approach. The target area of the insulator is determined using the Faster-Pixelwise Image Saliency by Aggregating (F-PISA) algorithm based on the color and structural features. The color model can be established based on the color feature of the damaged areas on the insulator surface, and hence the damaged area can be identified. Based on the information obtained above, the contour information can be extracted. With the preceding process, the fault location can be confirmed with a good accuracy. The performance of the proposed detection approach is assessed through a comparative study with other available solutions. The numerical result demonstrates that the suggested solution can detect the insulator flashover with improved performance in terms of the average detection rate and average efficient detection rate. Additional analysis is carried out to evaluate its robustness and real-time performance, which confirms its deployment feasibility in practice.
Fuzzy Stochastic Unit Commitment Model with Wind Power and Demand Response under Conditional Value-At-Risk Assessment
Authors: Yin Jiafu , Zhao Dongmei
Published: February 2018

With the increasing penetration of wind power and demand response integrated into the grid, the combined uncertainties from wind power and demand response have been a challenging concern for system operators. It is necessary to develop an approach to accommodate the combined uncertainties in the source side and load side. In this paper, the fuzzy stochastic conditional value-at-risk criterions are proposed as the risk measure of the combination of both wind power uncertainty and demand response uncertainty. To improve the computational tractability without sacrificing the accuracy, the fuzzy stochastic chance-constrained goal programming is proposed to transfer the fuzzy stochastic conditional value-at-risk to a deterministic equivalent. The operational risk of forecast error under fuzzy stochastic conditional value-at-risk assessment is represented by the shortage of reserve resource, which can be further divided into the load-shedding risk and the wind curtailment risk. To identify different priority levels for the different objective functions, the three-stage day-ahead unit commitment model is proposed through preemptive goal programming, in which the reliability requirement has the priority over the economic operation. Finally, a case simulation is performed on the IEEE 39-bus system to verify the effectiveness and efficiency of the proposed model.
Investigation of Unsteady Flow Interactions in a Transonic High Pressure Turbine Using Nonlinear Harmonic Method
Authors: Asghar Muhammad , Liu Yangwei , Cui Jiahuan , Lu Lipeng
Published: February 2018

The performance of a transonic high pressure turbine is mainly influenced by the unsteady interactions associated with the passing blades. In this paper, the unsteady flow interactions in a transonic turbine have been numerically investigated using the nonlinear harmonic (NLH) method in comparison with the steady and unsteady Reynolds-averaged Navier–Stokes (RANS). The comparison shows that the NLH method using three harmonics could capture the main unsteady flow interactions efficiently with about seven times smaller computational cost than the unsteady RANS, resulting in a more accurate time-averaged flow than for steady RANS. However, the continuity of the flow variables across the rotor-stator interface has shown some discrepancies compared with the unsteady RANS, which can be further satisfied by increasing the numbers of harmonics. The unsteady interactions are analyzed in detail; the results show that the wake and trailing edge shock from the upstream stator are the major sources of unsteadiness in the downstream rotor passage. The stator trailing edge shock impinges on the suction side of the passing rotor blades and generates pressure waves. These pressure waves are periodically reflected back to trigger the stator wake shedding. These waves are strong enough to travel through the rotor passage, and eventually affect the flow at the rotor’s trailing edge. The stator wakes are chopped by the downstream rotor, and travel through the rotor passage. This significantly enhances the unsteadiness of the flow near the rotor trailing edge. Lastly, the deterministic stresses and enthalpy distributions extracted from the NLH method have revealed that the effects of the unsteadiness are relatively weaker in the axial direction. Furthermore, the deterministic correlations analysis has shown that, some empirical deterministic correlations models based on the decay concept of compressors are not suitable for turbines.
Study of the Energy Conversion Process in the Electro-Hydrostatic Drive of a Vehicle
Authors: Grzesikiewicz Wiesław , Knap Lech , Makowski Michał , Pokorski Janusz
Published: February 2018

In the paper, we describe a study of an electro-hydrostatic hybrid drive of a utility van intended for city traffic. In this hybrid drive, the electric drive is periodically accompanied by hydrostatic drive, especially during acceleration and regenerative braking of the vehicle. We present a mathematical model of the hybrid drive as a set of dynamics and regulation equations of the van traveling at a given speed. On this basis, we construct a computer program which we use to simulate the processes of energy conversion in the electro-hydrostatic drive. The main goal of the numerical simulation is to assess the possibility of reducing energy intensity of the electric drive through such a support of the hydrostatic drive. The obtained results indicate that it is possible to reduce the load on elements of the electric system and, therefore, improve energy conversion.
The Third Quantization: To Tunnel or Not to Tunnel?
Authors: Bouhmadi-López Mariam , Krämer Manuel , Morais João , Robles-Pérez Salvador
Published: February 2018

Within the framework of the third quantization, we consider the possibility that an initially recollapsing baby universe can enter a stage of near de Sitter inflation by tunnelling through a Euclidean wormhole that connects the recollapsing and inflationary geometries. We present the solutions for the evolution of the scale factor in the Lorentzian and Euclidean regions as well as the probability that the baby universe indeed crosses the wormhole when it reaches its maximum size.
Genome-Wide Identification and Expression Analysis of the HD-Zip Gene Family in Wheat (Triticum aestivum L.)
Authors: Yue Hong , Shu Duntao , Wang Meng , Xing Guangwei , Zhan Haoshuang , Du Xianghong , Song Weining , Nie Xiaojun
Published: February 2018

The homeodomain-leucine zipper (HD-Zip) gene family, as plant-specific transcription factors, plays an important role in plant development and growth as well as in the response to diverse stresses. Although HD-Zip genes have been extensively studied in many plants, they had not yet been studied in wheat, especially those involved in response to abiotic stresses. In this study, 46 wheat HD-Zip genes were identified using a genome-wide search method. Phylogenetic analysis classified these genes into four groups, numbered 4, 5, 17 and 20 respectively. In total, only three genes with A, B and D homoeologous copies were identified. Furthermore, the gene interaction networks found that the TaHDZ genes played a critical role in the regulatory pathway of organ development and osmotic stress. Finally, the expression profiles of the wheat HD-Zips in different tissues and under various abiotic stresses were investigated using the available RNA sequencing (RNA-Seq) data and then validated by quantitative real-time polymerase chain reaction (qRT-PCR) to obtain the tissue-specific and stress-responsive candidates. This study systematically identifies the HD-Zip gene family in wheat at the genome-wide level, providing important candidates for further functional analysis and contributing to the better understanding of the molecular basis of development and stress tolerance in wheat.
Professional Well-Being of Practicing Physicians: The Roles of Autonomy, Competence, and Relatedness
Authors: Babenko Oksana
Published: February 2018

This study investigated the roles of basic psychological needs—autonomy, competence, and relatedness—in physicians’ professional well-being, specifically satisfaction with professional life, work-related engagement, and exhaustion. Using an online survey, quantitative data were collected from 57 practicing physicians. Overall, 65% of the participants were female; 49% were family medicine (FM) physicians, with the rest of the participants practicing in various non-FM specialties (e.g., internal medicine, pediatrics, surgery); and 47% were in the early-career stage (≤10 years in practice). Multivariate regression analyses indicated that of the three psychological needs, the need for relatedness had the largest unique contributions to physicians’ satisfaction with professional life, work-related engagement, and exhaustion, respectively. The unique contributions of the needs for autonomy and competence were relatively small. These findings extend basic psychological needs theory to the work domain of practicing physicians in an attempt to examine underpinnings of physicians’ professional well-being, a critical component of quality patient care.
Residents’ Self-Reported Health Effects and Annoyance in Relation to Air Pollution Exposure in an Industrial Area in Eastern-Estonia
Authors: Orru Hans , Idavain Jane , Pindus Mihkel , Orru Kati , Kesanurm Kaisa , Lang Aavo , Tomasova Jelena
Published: February 2018

Eastern Estonia has large oil shale mines and industrial facilities mainly focused on electricity generation from oil shale and shale oil extraction, which produce high air pollution emissions. The “Study of the health impact of the oil shale sector—SOHOS” was aimed at identifying the impacts on residents’ health and annoyance due to the industrial processing. First, a population-wide survey about health effects and annoyance was carried out. Second, the total and oil shale sectors’ emitted concentrations of benzene, phenol, and PM2.5 were modelled. Third, the differences between groups were tested and relationships between health effects and environmental pollution studied using multiple regression analysis. Compared to the control groups from non-industrial areas in Tartu or Lääne-Viru, residents of Ida-Viru more frequently (p < 0.05) reported wheezing, chest tightness, shortness of breath, asthma attacks, a long-term cough, hypertension, heart diseases, myocardial infarction, stroke, and diabetes. All health effects except asthma were reported more frequently among non-Estonians. People living in regions with higher levels of PM2.5, had significantly higher odds (p < 0.05) of experiencing chest tightness (OR = 1.13, 95% CI 1.02–1.26), shortness of breath (1.16, 1.03–1.31) or an asthma attack (1.22, 1.04–1.42) during the previous year. People living in regions with higher levels of benzene had higher odds of experiencing myocardial infarction (1.98, 1.11–3.53) and with higher levels of phenol chest tightness (1.44, 1.03–2.00), long-term cough (1.48, 1.06–2.07) and myocardial infarction (2.17, 1.23–3.83). The prevalence of adverse health effects was also higher among those who had been working in the oil shale sector. Next to direct health effects, up to a quarter of the residents of Ida-Viru County were highly annoyed about air pollution. Perceived health risk from air pollution increased the odds of being annoyed. Annoyed people in Ida-Viru had significantly higher odds of experiencing respiratory symptoms during the last 12 months, e.g., wheezing (2.30, 1.31–4.04), chest tightness (2.88, 1.91–4.33 or attack of coughing (1.99, 1.34–2.95).
Enhanced Portfolio Performance Using a Momentum Approach to Annual Rebalancing
Authors: Mattei Michael
Published: February 2018

After diversification, periodic portfolio rebalancing has become one of the most widely practiced methods for reducing portfolio risk and enhancing returns. Most of the rebalancing strategies found in the literature are generally regarded as contrarian approaches to rebalancing. A recent article proposed a rebalancing approach that incorporates a momentum approach to rebalancing. The momentum approach had a better risk adjusted return than either the traditional approach or a Buy-and-Hold approach. This article identifies an improvement to the momentum approach and then examines the impact of transactions costs and taxes on the portfolio performance of four active rebalancing approaches.
Microfinance and the Decision to Invest in Children’s Education
Authors: Viswanath PV
Published: February 2018

Although one of the primary objectives of microfinance has been the reduction of poverty through the provision of credit for income-generating purposes, evidence of its impact on poverty has been mixed. Even if there is no direct impact of microfinance, there may be an indirect positive impact through the effect of microcredit availability on families’ decisions to invest in their children’s education. In this paper, I describe a study undertaken to gauge the impact of microcredit availability on education expenditures for children of clients of a South Indian microfinance institution. I first look at some determinants of the demand for education and then go on to consider what we know about how microcredit affects this demand. I find that microcredit has an impact on the demand for education as mediated by wealth effects and status effects, i.e., microloans increase spending on education the greater the wealth and the greater the social status of the family. Focus group interviews suggest that the impact of microcredit on the demand for education comes mainly from the greater access to financial resources and, to a lesser degree, from an accompanying appreciation of the value of education.
Role of Galectins in Tumors and in Clinical Immunotherapy
Authors: Chou Feng-Cheng , Chen Heng-Yi , Kuo Chih-Chi , Sytwu Huey-Kang
Published: February 2018

Galectins are glycan-binding proteins that contain one or two carbohydrate domains and mediate multiple biological functions. By analyzing clinical tumor samples, the abnormal expression of galectins is known to be linked to the development, progression and metastasis of cancers. Galectins also have diverse functions on different immune cells that either promote inflammation or dampen T cell-mediated immune responses, depending on cognate receptors on target cells. Thus, tumor-derived galectins can have bifunctional effects on tumor and immune cells. This review focuses on the biological effects of galectin-1, galectin-3 and galectin-9 in various cancers and discusses anticancer therapies that target these molecules.
Photodynamic Inactivation Potentiates the Susceptibility of Antifungal Agents against the Planktonic and Biofilm Cells of Candida albicans
Authors: Huang Mu-Ching , Shen Mandy , Huang Yi-Jhen , Lin Hsiao-Chi , Chen Chin-Tin
Published: February 2018

Photodynamic inactivation (PDI) has been shown to be a potential treatment modality against Candida infection. However, limited light penetration might leave some cells alive and undergoing regrowth. In this study, we explored the possibility of combining PDI and antifungal agents to enhance the therapeutic efficacy of Candida albicans and drug-resistant clinical isolates. We found that planktonic cells that had survived toluidine blue O (TBO)-mediated PDI were significantly susceptible to fluconazole within the first 2 h post PDI. Following PDI, the killing efficacy of antifungal agents relates to the PDI dose in wild-type and drug-resistant clinical isolates. However, only a 3-log reduction was found in the biofilm cells, suggesting limited therapeutic efficacy under the combined treatment of PDI and azole antifungal drugs. Using confocal microscopic analysis, we showed that TBO-mediated PDI could partially remove the extracellular polymeric substance (EPS) of biofilm. Finally, we showed that a combination of PDI with caspofungin could result in the complete killing of biofilms compared to those treated with caspofungin or PDI alone. These results clearly indicate that the combination of PDI and antifungal agents could be a promising treatment against C. albicans infections.
Improvement of the Chondrocyte-Specific Phenotype upon Equine Bone Marrow Mesenchymal Stem Cell Differentiation: Influence of Culture Time, Transforming Growth Factors and Type I Collagen siRNAs on the Differentiation Index
Authors: Branly Thomas , Contentin Romain , Desancé Mélanie , Jacquel Thibaud , Bertoni Lélia , Jacquet Sandrine , Mallein-Gerin Frédéric , Denoix Jean-Marie , Audigié Fabrice , Demoor Magali , Galéra Philippe
Published: February 2018

Articular cartilage is a tissue characterized by its poor intrinsic capacity for self-repair. This tissue is frequently altered upon trauma or in osteoarthritis (OA), a degenerative disease that is currently incurable. Similar musculoskeletal disorders also affect horses and OA incurs considerable economic loss for the equine sector. In the view to develop new therapies for humans and horses, significant progress in tissue engineering has led to the emergence of new generations of cartilage therapy. Matrix-associated autologous chondrocyte implantation is an advanced 3D cell-based therapy that holds promise for cartilage repair. This study aims to improve the autologous chondrocyte implantation technique by using equine mesenchymal stem cells (MSCs) from bone marrow differentiated into chondrocytes that can be implanted in the chondral lesion. The optimized protocol relies on culture under hypoxia within type I/III collagen sponges. Here, we explored three parameters that influence MSC differentiation: culture times, growth factors and RNA interference strategies. Our results suggest first that an increase in culture time from 14 to 28 or 42 days lead to a sharp increase in the expression of chondrocyte markers, notably type II collagen (especially the IIB isoform), along with a concomitant decrease in HtrA1 expression. Nevertheless, the expression of type I collagen also increased with longer culture times. Second, regarding the growth factor cocktail, TGF-β3 alone showed promising result but the previously tested association of BMP-2 and TGF-β1 better limits the expression of type I collagen. Third, RNA interference targeting Col1a2 as well as Col1a1 mRNA led to a more significant knockdown, compared with a conventional strategy targeting Col1a1 alone. This chondrogenic differentiation strategy showed a strong increase in the Col2a1:Col1a1 mRNA ratio in the chondrocytes derived from equine bone marrow MSCs, this ratio being considered as an index of the functionality of cartilage. These data provide evidence of a more stable chondrocyte phenotype when combining Col1a1 and Col1a2 siRNAs associated to a longer culture time in the presence of BMP-2 and TGF-β1, opening new opportunities for preclinical trials in the horse. In addition, because the horse is an excellent model for human articular cartilage disorders, the equine therapeutic approach developed here can also serve as a preclinical step for human medicine.
Apoptosis: A Target for Anticancer Therapy
Authors: Pfeffer Claire , Singh Amareshwar
Published: February 2018

Apoptosis, the cell’s natural mechanism for death, is a promising target for anticancer therapy. Both the intrinsic and extrinsic pathways use caspases to carry out apoptosis through the cleavage of hundreds of proteins. In cancer, the apoptotic pathway is typically inhibited through a wide variety of means including overexpression of antiapoptotic proteins and under-expression of proapoptotic proteins. Many of these changes cause intrinsic resistance to the most common anticancer therapy, chemotherapy. Promising new anticancer therapies are plant-derived compounds that exhibit anticancer activity through activating the apoptotic pathway.
Beyond the Matrix: The Many Non-ECM Ligands for Integrins
Authors: LaFoya Bryce , Munroe Jordan , Miyamoto Alison , Detweiler Michael , Crow Jacob , Gazdik Tana , Albig Allan
Published: February 2018

The traditional view of integrins portrays these highly conserved cell surface receptors as mediators of cellular attachment to the extracellular matrix (ECM), and to a lesser degree, as coordinators of leukocyte adhesion to the endothelium. These canonical activities are indispensable; however, there is also a wide variety of integrin functions mediated by non-ECM ligands that transcend the traditional roles of integrins. Some of these unorthodox roles involve cell-cell interactions and are engaged to support immune functions such as leukocyte transmigration, recognition of opsonization factors, and stimulation of neutrophil extracellular traps. Other cell-cell interactions mediated by integrins include hematopoietic stem cell and tumor cell homing to target tissues. Integrins also serve as cell-surface receptors for various growth factors, hormones, and small molecules. Interestingly, integrins have also been exploited by a wide variety of organisms including viruses and bacteria to support infectious activities such as cellular adhesion and/or cellular internalization. Additionally, the disruption of integrin function through the use of soluble integrin ligands is a common strategy adopted by several parasites in order to inhibit blood clotting during hematophagy, or by venomous snakes to kill prey. In this review, we strive to go beyond the matrix and summarize non-ECM ligands that interact with integrins in order to highlight these non-traditional functions of integrins.
Alternative Erythropoietin Receptors in the Nervous System
Authors: Ostrowski Daniela , Heinrich Ralf
Published: February 2018

In addition to its regulatory function in the formation of red blood cells (erythropoiesis) in vertebrates, Erythropoietin (Epo) contributes to beneficial functions in a variety of non-hematopoietic tissues including the nervous system. Epo protects cells from apoptosis, reduces inflammatory responses and supports re-establishment of compromised functions by stimulating proliferation, migration and differentiation to compensate for lost or injured cells. Similar neuroprotective and regenerative functions of Epo have been described in the nervous systems of both vertebrates and invertebrates, indicating that tissue-protective Epo-like signaling has evolved prior to its erythropoietic function in the vertebrate lineage. Epo mediates its erythropoietic function through a homodimeric Epo receptor (EpoR) that is also widely expressed in the nervous system. However, identification of neuroprotective but non-erythropoietic Epo splice variants and Epo derivatives indicated the existence of other types of Epo receptors. In this review, we summarize evidence for potential Epo receptors that might mediate Epo’s tissue-protective function in non-hematopoietic tissue, with focus on the nervous system. In particular, besides EpoR, we discuss three other potential neuroprotective Epo receptors: (1) a heteroreceptor consisting of EpoR and common beta receptor (βcR), (2) the Ephrin (Eph) B4 receptor and (3) the human orphan cytokine receptor-like factor 3 (CRLF3).
Effects of Pre-Workout Supplements on Power Maintenance in Lower Body and Upper Body Tasks
Authors: Lane Michael , Byrd Mark
Published: February 2018

Recently, the use of pre-workout supplements has become popular. Research has shown their ability to increase performance for single bouts but little exists showing their ability to maintain this increase in performance over multiple bouts. Purpose: To investigate the effects of supplements on power production and the maintenance of upper and lower body tasks. Methods: Twenty-three males (22.9 ± 3.6 years, 175.6 ± 6.5 cm, 86.9 ± 15.1 kg, 19.1 ± 8.4 BF% mean ± standard deviation (SD)) were familiarized with the testing protocols and maximal bench press performances were attained (109.1 ± 34.0 kg). Utilizing a double-blind crossover design, subjects completed three trials of five countermovement vertical jumps before and after a high-intensity cycle sprint protocol, which consisted of ten maximal 5 s cycle ergometer sprints utilizing 7.5% of the subject’s body weight as resistance, with 55 s of recovery between each sprint. Subjects ingested in a randomized order a commercially available pre-workout supplement (SUP), placebo + 300 mg caffeine (CAF), or a placebo (PLA). Peak power (PP), mean power (MP), and minimum power (MNP) were recorded for each sprint. Subjects performed a velocity bench press test utilizing 80% of their predetermined one repetition maximum (1RM) for 10 sets of 3 repetitions for maximal speed, with one-minute rests between sets. Maximal velocity from each set was recorded. For analysis, bike sprint and bench press data were normalized to the placebo trial. Results: Cycle sprint testing showed no significant differences through the testing sessions. In the bench press, the peak velocity was higher with both the SUP and CAF treatments compared to the placebo group (1.09 ± 0.17 SUP, 1.10 ± 0.16 CAF, and 1 ± 0 PLA, p < 0.05) and the supplement group was higher than the PLA for mean velocity (1.11 ± 0.18 SUP and 1 ± 0 PLA, p < 0.05). Vertical jump performance and lactate levels were not significantly different (RMANOVA showed no significant differences from any treatments). Conclusions: Supplementation with a pre-workout supplement or placebo with caffeine showed positive benefits in performance in bench press velocity.
Ovarian Cancers: Genetic Abnormalities, Tumor Heterogeneity and Progression, Clonal Evolution and Cancer Stem Cells
Authors: Testa Ugo , Petrucci Eleonora , Pasquini Luca , Castelli Germana , Pelosi Elvira
Published: February 2018

Four main histological subtypes of ovarian cancer exist: serous (the most frequent), endometrioid, mucinous and clear cell; in each subtype, low and high grade. The large majority of ovarian cancers are diagnosed as high-grade serous ovarian cancers (HGS-OvCas). TP53 is the most frequently mutated gene in HGS-OvCas; about 50% of these tumors displayed defective homologous recombination due to germline and somatic BRCA mutations, epigenetic inactivation of BRCA and abnormalities of DNA repair genes; somatic copy number alterations are frequent in these tumors and some of them are associated with prognosis; defective NOTCH, RAS/MEK, PI3K and FOXM1 pathway signaling is frequent. Other histological subtypes were characterized by a different mutational spectrum: LGS-OvCas have increased frequency of BRAF and RAS mutations; mucinous cancers have mutation in ARID1A, PIK3CA, PTEN, CTNNB1 and RAS. Intensive research was focused to characterize ovarian cancer stem cells, based on positivity for some markers, including CD133, CD44, CD117, CD24, EpCAM, LY6A, ALDH1. Ovarian cancer cells have an intrinsic plasticity, thus explaining that in a single tumor more than one cell subpopulation, may exhibit tumor-initiating capacity. The improvements in our understanding of the molecular and cellular basis of ovarian cancers should lead to more efficacious treatments.
Electrospray Deposition of ZnO Thin Films and Its Application to Gas Sensors
Authors: Li Wenwang , Lin Jinghua , Wang Xiang , Jiang Jiaxin , Guo Shumin , Zheng Gaofeng
Published: February 2018

Electrospray is a simple and cost-effective method to fabricate micro-structured thin films. This work investigates the electrospray process of ZnO patterns. The effects of experimental parameters on jet characteristics and electrosprayed patterns are studied. The length of stable jets increases with increasing applied voltage and flow rate, and decreases with increasing nozzle-to-substrate distance, while electrospray angles exhibit an opposite trend with respect to the stable jet lengths. The diameter of electrosprayed particles decreases with increasing applied voltage, and increases with flow rate. Furthermore, an alcohol gas sensor is presented. The ZnAc is calcined into ZnO, which reveals good repeatability and stability of response in target gas. The sensing response, defined as the resistance ratio of R0/Rg, where R0 and Rg are resistance of ZnO in air and alcohol gas, increases with the concentration of alcohol vapors and electrospray deposition time.
Tulbaghia violacea and Allium ursinum Extracts Exhibit Anti-Parasitic and Antimicrobial Activities
Authors: Krstin Sonja , Sobeh Mansour , Braun Markus , Wink Michael
Published: February 2018

Garlic has played an important role in culinary arts and remedies in the traditional medicine throughout human history. Parasitic infections represent a burden in the society of especially poor countries, causing more than 1 billion infections every year and leading to around one million deaths. In this study, we investigated the mode of anti-parasitic activity of “wild garlics” Tulbaghia violacea and Allium ursinum dichloromethane extracts against parasites Trypanosoma brucei brucei and Leishmania tarentolae with regard to their already known antimicrobial activity. We also evaluated their cytotoxic potential against human cells. Both extracts showed a relevant trypanocidal and leishmanicidal activity, although L. tarentolae was less sensitive. We determined that the probable mode of action of both extracts is the irreversible inhibition of the activity of Trypanosoma brucei trypanothione reductase enzyme. The extracts showed a mild cytotoxic activity against human keratinocytes. They also exhibited weak—in most cases comparable—antibacterial and antifungal activity. HPLC-MS/MS analysis showed that both extracts are abundant in sulfur compounds. Thus, for the first time, the ability of Allium ursinum and Tulbaghia violacea to kill Trypanosoma sp. and Leishmania sp. parasites, probably by binding to and inactivating sulfur-containing compounds essential for the survival of the parasite, is shown.
Molecularly Imprinted Polymers as Extracting Media for the Chromatographic Determination of Antibiotics in Milk
Authors: Bitas Dimitrios , Samanidou Victoria
Published: February 2018

Milk-producing animals are typically kept stationary in overcrowded large-scale farms and in most cases under unsanitary conditions, which promotes the development of infections. In order to maintain sufficient health status among the herd or promote growth and increase production, farmers administer preventative antibiotic doses to the animals through their feed. However, many antibiotics used in cattle farms are intended for the treatment of bacterial infections in humans. This results in the development of antibiotic-resistant bacteria which pose a great risk for public health. Additionally, antibiotic residues are found in milk and dairy products, with potential toxic effects for the consumers. Hence the need of antibiotic residues monitoring in milk arises. Analytical methods were developed for the determination of antibiotics in milk, with key priority given to the analyte extraction and preconcentration step. Extraction can benefit from the production of molecularly imprinted polymers (MIPs) that can be applied as sorbents for the extraction of specific antibiotics. This review focuses on the principals of molecular imprinting technology and synthesis methods of MIPs, as well as the application of MIPs and MIPs composites for the chromatographic determination of various antibiotic categories in milk found in the recent literature.
Carbamates as Potential Prodrugs and a New Warhead for HDAC Inhibition
Authors: King Kristina , Hauser Alexander-Thomas , Melesina Jelena , Sippl Wolfgang , Jung Manfred
Published: February 2018

We designed and synthesized carbamates of the clinically-approved HDAC (histone deacetylase) inhibitor vorinostat (suberoylanilide hydroxamic acid, SAHA) in order to validate our previously-proposed hypothesis that these carbamates might serve as prodrugs for hydroxamic acid containing HDAC inhibitors. Biochemical assays proved our new compounds to be potent inhibitors of histone deacetylases in vitro, and they also showed antiproliferative effects in leukemic cells. These results, as well as stability analysis led to the suggestion that the intact carbamates are inhibitors of histone deacetylases themselves, representing a new zinc-binding warhead in HDAC inhibitor design. This suggestion was further supported by the synthesis and evaluation of a carbamate derivative of the HDAC6-selective inhibitor bufexamac.
Feasibility of Using Gluconolactone, Trehalose and Hydroxy-Propyl Gamma Cyclodextrin to Enhance Bendroflumethiazide Dissolution Using Lyophilisation and Physical Mixing Techniques
Authors: Saleh Ashraf , McGarry Kenneth , Chaw Cheng , Elkordy Amal
Published: February 2018

Purpose: Hydrophobic drugs are facing a major challenge in dissolution rate enhancement and solubility in aqueous solutions; therefore, a variety of methods have been used to improve dissolution rate and/or solubility of bendroflumethiazide as a model hydrophobic drug. Methods: In this study, two main methods (physical mixing and lyophilisation) were used with gluconolactone, hydroxyl propyl γ-ccyclodextrin, and trehalose to explore this challenge. Bendroflumethiazide, practically insoluble in water, was mixed with one of the three excipients gluconolactone, hydroxyl propyl γ-cyclodextrin, and trehalose in three different ratios 1:1, 1:2, 1:5. To the best of our knowledge, the dissolution of the drug has not been previously enhanced by using either these methods or any of the used excipients. Samples containing drug and each of the excipients were characterized via dissolution testing, Fourier Transform infra-red spectroscopy, differential scanning calorimetry, and scanning electron microscopy. Results: The used methods showed a significant enhancement in dug dissolution rate; physical mixing significantly, p < 0.05, increased the percentage of the drug released with time; for example, bendroflumethiazide dissolution in distilled water was improved from less than 20% to 99.79% within 90 min for physically mixed drug-cyclodextrin 1:5. The lyophilisation process was enhanced and the drug dissolution rate and the highest drug dissolution was achieved for (drug-gluconolactone 1:1) with 98.98% drug release within 90 min. Conclusions: the physical mixing and freeze drying processes significantly increased the percentage of drug release with time.
A Holistic Concept to Design Optimal Water Supply Infrastructures for Informal Settlements Using Remote Sensing Data
Authors: Rausch Lea , Friesen John , Altherr Lena , Meck Marvin , Pelz Peter
Published: February 2018

Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.
The Correlation Coefficient as a Simple Tool for the Localization of Errors in Spectroscopic Imaging Data
Authors: Inamdar Deep , Leblanc George , Soffer Raymond , Kalacska Margaret
Published: February 2018

The correlation coefficient (CC) was substantiated as a simple, yet robust statistical tool in the quality assessment of hyperspectral imaging (HSI) data. The sensitivity of the metric was also characterized with respect to artificially-induced errors. The CC was found to be sensitive to spectral shifts and single feature modifications in hyperspectral ground data despite the high, artificially-induced, signal-to-noise ratio (SNR) of 100:1. The study evaluated eight airborne hyperspectral images that varied in acquisition spectrometer, acquisition date and processing methodology. For each image, we identified a uniform ground target region of interest (ROI) that was comprised of a single asphalt road pixel from each column within the sensor field-of-view (FOV). A CC was calculated between the spectra from each of the pixels in the ROI and the data from the center pixel. Potential errors were located by reductions in the CCs below a designated threshold, which was derived from the results of the sensitivity tests. The spectral range associated with each error was established using a windowing technique where the CCs were recalculated after removing the spectral data within various windows. Errors were isolated in the spectral window that removed the previously-identified reductions in the CCs. Finer errors were detected by calculating the CCs across the ROI in the spectral range surrounding various atmospheric absorption features. Despite only observing deviations in the CCs from the 3rd–6th decimal places, non-trivial errors were detected in the imagery. An error was detected within a single band of the shortwave infrared imagery. Errors were also observed throughout the visible-near-infrared imagery, especially in the blue end. With this methodology, it was possible to immediately gauge the spectral consistency of the HSI data across the FOV. Consequently, the effectiveness of various processing methodologies and the spectral consistency of the imaging spectrometers themselves could be studied. Overall, the research highlights the utility of the CC as a simple, low monetary cost, analytical tool for the localization of errors in spectroscopic imaging data.
New Adaptable All-in-One Strategy for Estimating Advanced Tropospheric Parameters and Using Real-Time Orbits and Clocks
Authors: Douša Jan , Václavovic Pavel , Zhao Lewen , Kačmařík Michal
Published: February 2018

We developed a new strategy for a synchronous generation of real-time (RT) and near real-time (NRT) tropospheric products. It exploits the precise point positioning method with Kalman filtering and backward smoothing, both supported by real-time orbit and clock products. The strategy can be optimized for the latency or the accuracy of NRT production. In terms of precision, it is comparable to the traditional NRT network solution using deterministic models in the least-square adjustment. Both RT and NRT solutions provide a consistent set of tropospheric parameters such as zenith total delays, horizontal tropospheric gradients and slant delays, all with a high resolution and optimally exploiting all observations from available GNSS multi-constellations. As the new strategy exploits RT processing, we assessed publicly precise RT products and results of RT troposphere monitoring. The backward smoothing applied for NRT solution, when using an optimal latency of 30 min, reached an improvement of 20% when compared to RT products. Additionally, multi-GNSS solutions provided more accurate (by 25%) tropospheric parameters, and the impact will further increase when constellations are complete and supported with precise models and products. The new strategy is ready to replace our NRT contribution to the EUMETNET EIG GNSS Water Vapour Programme (E-GVAP) and effectively support all modern multi-GNSS tropospheric products.
Energy Level-Based Abnormal Crowd Behavior Detection
Authors: Zhang Xuguang , Zhang Qian , Hu Shuo , Guo Chunsheng , Yu Hui
Published: February 2018

The change of crowd energy is a fundamental measurement for describing a crowd behavior. In this paper, we present a crowd abnormal detection method based on the change of energy-level distribution. The method can not only reduce the camera perspective effect, but also detect crowd abnormal behavior in time. Pixels in the image are treated as particles, and the optical flow method is adopted to extract the velocities of particles. The qualities of different particles are distributed as different value according to the distance between the particle and the camera to reduce the camera perspective effect. Then a crowd motion segmentation method based on flow field texture representation is utilized to extract the motion foreground, and a linear interpolation calculation is applied to pedestrian’s foreground area to determine their distance to the camera. This contributes to the calculation of the particle qualities in different locations. Finally, the crowd behavior is analyzed according to the change of the consistency, entropy and contrast of the three descriptors for co-occurrence matrix. By calculating a threshold, the timestamp when the crowd abnormal happens is determined. In this paper, multiple sets of videos from three different scenes in UMN dataset are employed in the experiment. The results show that the proposed method is effective in characterizing anomalies in videos.
Amyloid Beta Detection by Faradaic Electrochemical Impedance Spectroscopy Using Interdigitated Microelectrodes
Authors: Park Jin , Kim Hye , Lee Ji-Hoon , Park Jung , Kim Jinsik , Hwang Kyo , Lee Byung
Published: February 2018

Faradaic electrochemical impedance spectroscopy (f-EIS) in the presence of redox reagent, e.g., [Fe(CN)6]3−/4−, is widely used in biosensors owing to its high sensitivity. However, in sensors detecting amyloid beta (Aβ), the redox reagent can cause the aggregation of Aβ, which is a disturbance factor in accurate detection. Here, we propose an interdigitated microelectrode (IME) based f-EIS technique that can alleviate the aggregation of Aβ and achieve high sensitivity by buffer control. The proposed method was verified by analyzing three different EIS-based sensors: non-faradaic EIS (nf-EIS), f-EIS, and the proposed f-EIS with buffer control. We analyzed the equivalent circuits of nf-EIS and f-EIS sensors. The dominant factors of sensitivity were analyzed, and the impedance change rates via Aβ reaction was compared. We measured the sensitivity of the IME sensors based on nf-EIS, f-EIS, and the proposed f-EIS. The results demonstrate that the proposed EIS-based IME sensor can detect Aβ with a sensitivity of 7.40-fold and 10.93-fold higher than the nf-EIS and the f-EIS sensors, respectively.
A New Real-Time Cycle Slip Detection and Repair Method under High Ionospheric Activity for a Triple-Frequency GPS/BDS Receiver
Authors: Liu Wanke , Jin Xueyuan , Wu Mingkui , Hu Jie , Wu Yun
Published: February 2018

Cycle slip detection and repair is a prerequisite for high-precision global navigation satellite system (GNSS)-based positioning. With the modernization and development of GNSS systems, more satellites are available to transmit triple-frequency signals, which allows the introduction of additional linear combinations and provides new opportunities for cycle slip detection and repair. In this paper, we present a new real-time cycle slip detection and repair method under high ionospheric activity for undifferenced Global Positioning System (GPS)/BeiDou Navigation Satellite System (BDS) triple-frequency observations collected with a single receiver. First, three optimal linearly independent geometry-free pseudorange minus phase combinations are selected to correctly and uniquely determine the cycle slips on the original triple-frequency carrier phase observations. Then, a second-order time-difference algorithm is employed for the pseudorange minus phase combinations to mitigate the impact of between-epoch ionospheric residuals on cycle slip detection, which is especially beneficial under high ionospheric activity. The performance of the approach is verified with static GPS/BDS triple-frequency observations that are collected with a 30 s sampling interval under active ionospheric conditions, and observations are manually inserted with simulated cycle slips. The results show that the method can correctly detect and repair cycle slips at a resolution as small as 1 cycle. Moreover, kinematic data collected from car-driven and airborne experiments are also processed to verify the performance of the method. The experimental results also demonstrate that the method is effective in processing kinematic data.
Experimental Study of Multispectral Characteristics of an Unmanned Aerial Vehicle at Different Observation Angles
Authors: Zheng Haijing , Bai Tingzhu , Wang Quanxi , Cao Fengmei , Shao Long , Sun Zhaotian
Published: February 2018

This study investigates multispectral characteristics of an unmanned aerial vehicle (UAV) at different observation angles by experiment. The UAV and its engine are tested on the ground in the cruise state. Spectral radiation intensities at different observation angles are obtained in the infrared band of 0.9–15 μm by a spectral radiometer. Meanwhile, infrared images are captured separately by long-wavelength infrared (LWIR), mid-wavelength infrared (MWIR), and short-wavelength infrared (SWIR) cameras. Additionally, orientation maps of the radiation area and radiance are obtained. The results suggest that the spectral radiation intensity of the UAV is determined by its exhaust plume and that the main infrared emission bands occur at 2.7 μm and 4.3 μm. At observation angles in the range of 0°–90°, the radiation area of the UAV in MWIR band is greatest; however, at angles greater than 90°, the radiation area in the SWIR band is greatest. In addition, the radiance of the UAV at an angle of 0° is strongest. These conclusions can guide IR stealth technique development for UAVs.
Accurate Energy Consumption Modeling of IEEE 802.15.4e TSCH Using Dual-Band OpenMote Hardware
Authors: Daneels Glenn , Municio Esteban , Van de Velde Bruno , Ergeerts Glenn , Weyn Maarten , Latré Steven , Famaey Jeroen
Published: February 2018

The Time-Slotted Channel Hopping (TSCH) mode of the IEEE 802.15.4e amendment aims to improve reliability and energy efficiency in industrial and other challenging Internet-of-Things (IoT) environments. This paper presents an accurate and up-to-date energy consumption model for devices using this IEEE 802.15.4e TSCH mode. The model identifies all network-related CPU and radio state changes, thus providing a precise representation of the device behavior and an accurate prediction of its energy consumption. Moreover, energy measurements were performed with a dual-band OpenMote device, running the OpenWSN firmware. This allows the model to be used for devices using 2.4 GHz, as well as 868 MHz. Using these measurements, several network simulations were conducted to observe the TSCH energy consumption effects in end-to-end communication for both frequency bands. Experimental verification of the model shows that it accurately models the consumption for all possible packet sizes and that the calculated consumption on average differs less than 3% from the measured consumption. This deviation includes measurement inaccuracies and the variations of the guard time. As such, the proposed model is very suitable for accurate energy consumption modeling of TSCH networks.