bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence and Exposure Assessment of Mycotoxins in Ready-to-Eat Tree Nut Products through Ultra-High Performance Liquid Chromatography Coupled with High Resolution Q-Orbitrap Mass Spectrometry
Authors: Narváez Alfonso , Rodríguez-Carrasco Yelko , Castaldo Luigi , Izzo Luana , Graziani Giulia , Ritieni Alberto
Published: August 2020

Tree nuts have become popular snacks due to their attributed benefits in the health state. Nevertheless, their susceptibility to fungal contamination lead to the occurrence of potentially dangerous mycotoxins. Hence, the aim of this work was to evaluate the presence of mycotoxins in ready-to-eat almonds, walnuts, and pistachios from Italian markets. The most relevant mycotoxin found in almonds was α-zearalanol in 18% of samples (n = 17) ranging from 3.70 to 4.54 µg/kg. Walnut samples showed frequent contamination with alternariol, present in 53% of samples (n = 22) at levels from 0.29 to 1.65 µg/kg. Pistachios (n = 15) were the most contaminated commodity, with β-zearalenol as the most prevalent toxin present in 59% of samples ranging from 0.96 to 8.60 µg/kg. In the worst-case scenario, the exposure to zearalenone-derived forms accounted for 15.6% of the tolerable daily intake, whereas it meant 12.4% and 21.2% of the threshold of toxicological concern for alternariol and alternariol monomethyl-ether, respectively. The results highlighted the extensive presence of Alternaria toxins and zearalenone-derived forms, scarcely studied in ready-to-eat tree nut products, highlighting the necessity to include these mycotoxins in analytical methods to perform more realistic risk assessments.
Effect of KDP-Crystal Material Properties on Surface Morphology in Ultra-Precision Fly Cutting
Authors: Chen Dongju , Li Shupei , Fan Jinwei
Published: August 2020

To study the effect of material properties on the surface morphology of potassium dihydrogen phosphate (KDP) crystals, an ultra-precision fly cutting machine tool with a single-point diamond tool was used to perform a cutting experiment on (100) crystal plane of the KDP crystal. The elastic modulus, shear modulus, hardness, and dislocation of KDP crystals are taken into the cutting force model by introducing the strain gradient plasticity theory. Since the size effect and dynamic response will affect the surface roughness during ultra-precision machining, the surface roughness of workpieces in ultra-precision fly cutting is hard to predict. Based on the previously established strain gradient plasticity theoretical model, cutting force model, and the dynamic characteristics of the ultra-precision fly cutting system, a surface morphology prediction model under the influence of KDP crystal material properties was established. Finally, the accuracy of the surface morphology prediction model was verified by ultra-precision fly cutting experiments, and identified the frequency range of the characteristic signal caused by the anisotropy of the KDP crystal from the frequency, thereby verifying the KDP crystal material properties has a significant effect on the surface of the machined workpiece roughness.
Effect of Charging Parameter on Fruit Battery-Based Oil Palm Maturity Sensor
Authors: Misron Norhisam , Kamal Azhar Nisa Syakirah , Hamidon Mohd Nizar , Aris Ishak , Tashiro Kunihisa , Nagata Hirokazu
Published: August 2020

Oil palm is one of the key industries highly observed in Malaysia, due to its high demand both whether locally or internationally. The oil extraction rate (OER) in palm oil production is used as an element to identify the performance of the mills, estates and producers. In view of this, there are specific instrument or sensor needs to be implemented at the mills especially during the reception of fresh fruit bunches (FFB) transported from the field for oil content processing. This paper aims to study and propose the use of a fruit battery-based oil palm maturity sensor to analyse the effect of the sensor to various parameters. The study utilizes a charging method with different parameters, including a moisture content test on the palm oil samples. Three types of parameters are tested along with the different grades of oil palm fruit from different bunches, such as the load resistance, charging voltage and charging time. The repeatability data of the samples are obtained with the used list of values in each parameter. The results show that the parameters tested for the unripe, under ripe and ripe samples can affect the sensor sensitivity.
The Growth Promotion of Peppers (Capsicum annuum L.) by Trichoderma guizhouense NJAU4742-Based Biological Organic Fertilizer: Possible Role of Increasing Nutrient Availabilities
Authors: Liu Qiumei , Meng Xiaohui , Li Tuo , Raza Waseem , Liu Dongyang , Shen Qirong
Published: August 2020

Trichoderma spp. is a cosmopolitan group of soil fungi which plays a remarkable role in stimulating plant growth after interacting with plant roots and has good application prospects in intensive agriculture. In this study, rice straw and amino acids improved the population of Trichoderma guizhouense NJAU4742 under solid-state fermentation and helped us develop a new type of organic fertilizer. The effects of this biological organic fertilizer were evaluated in the growth of peppers (Capsicum annuum L.) for two seasons under sandy and mountain soils. In the first season, the yields in T6 (0.06% solid fermentation products in soil) and AT6 (added 0.06% solid fermentation products and 1% amino acid organic fertilizer in soil) treatments were increased by 41.8% and 52.3% in sandy soil and by 51.6% and 46.5% in mountain soil, respectively, compared with chemical fertilizer. During the second season, the same trend was obtained in both sandy and mountain soils. Soil peroxidase activity (125.2 μmol·g−1 dw), urease activity (58.7 μmol·g−1 dw) and invertase activity (13.11 mg·g−1 dw) reached their highest levels in biological organic fertilizer compared to the treatments with chemical fertilizer and solid fermentation products. Redundancy analysis showed that crop yield was positively correlated with enzyme activities, soil organic carbon, total nitrogen, and available phosphorus. Thus, we demonstrated that NJAU4742-enriched biological organic fertilizer could accelerate the transformation of nutrients and promote pepper growth.
A Novel Primer Mixture for GH48 Genes: Quantification and Identification of Truly Cellulolytic Bacteria in Biogas Fermenters
Authors: Rettenmaier Regina , Lo Yat Kei , Schmidt Larissa , Munk Bernhard , Lagkouvardos Ilias , Neuhaus Klaus , Schwarz Wolfgang , Liebl Wolfgang , Zverlov Vladimir
Published: August 2020

Genomic studies revealed the glycoside hydrolases of family 48 (GH48) as a powerful marker for the identification of truly cellulolytic bacteria. Here we report an improved method for detecting cellulolytic bacteria in lab-scale biogas fermenters by using GH48 genes as a molecular marker in DNA and RNA samples. We developed a mixture of primers for the specific amplification of a GH48 gene region in a broad range of bacteria. Additionally, we built a manually curated reference database containing GH48 gene sequences directly linked to the corresponding taxonomic information. Phylogenetic correlation analysis of GH48 to 16S rRNA gene sequences revealed that GH48 gene sequences with 94% identity belong with high confidence to the same genus. Applying this analysis, GH48 amplicon reads revealed that at mesophilic fermenter conditions, 50–99% of the OTUs appear to belong to novel taxa. In contrast, at thermophilic conditions, GH48 gene sequences from the genus Hungateiclostridium dominated with 60–91% relative abundance. The novel primer combinations enabled detection and relative quantification of a wide spectrum of GH48 genes in cellulolytic microbial communities. Deep phylogenetic correlation analysis and a simplified taxonomic identification with the novel database facilitate identification of cellulolytic organisms, including the detection of novel taxa in biogas fermenters.
Formation and Maturation of the Phagosome: A Key Mechanism in Innate Immunity against Intracellular Bacterial Infection
Authors: Lee Hyo-Ji , Woo Yunseo , Hahn Tae-Wook , Jung Young Mee , Jung Yu-Jin
Published: August 2020

Phagocytosis is an essential mechanism in innate immune defense, and in maintaining homeostasis to eliminate apoptotic cells or microbes, such as Mycobacterium tuberculosis, Salmonella enterica, Streptococcus pyogenes and Legionella pneumophila. After internalizing microbial pathogens via phagocytosis, phagosomes undergo a series of ‘maturation’ steps, to form an increasingly acidified compartment and subsequently fuse with the lysosome to develop into phagolysosomes and effectively eliminate the invading pathogens. Through this mechanism, phagocytes, including macrophages, neutrophils and dendritic cells, are involved in the processing of microbial pathogens and antigen presentation to T cells to initiate adaptive immune responses. Therefore, phagocytosis plays a role in the bridge between innate and adaptive immunity. However, intracellular bacteria have evolved diverse strategies to survive and replicate within hosts. In this review, we describe the sequential stages in the phagocytosis process. We also discuss the immune evasion strategies used by pathogens to regulate phagosome maturation during intracellular bacterial infection, and indicate that these might be used for the development of potential therapeutic strategies for infectious diseases.
Up in the Air: Evidence of Dehydration Risk and Long-Haul Flight on Athletic Performance
Authors: Zubac Damir , Buoite Stella Alex , Morrison Shawnda A.
Published: August 2020

The microclimate of an airline cabin consists of dry, recirculated, and cool air, which is maintained at lower pressure than that found at sea level. Being exposed to this distinctive, encapsulated environment for prolonged durations, together with the short-term chair-rest immobilization that occurs during long-haul flights, can trigger distinct and detrimental reactions to the human body. There is evidence that long-haul flights promote fluid shifts to the lower extremity and induce changes in blood viscosity which may accelerate dehydration, possibly compromising an athlete’s potential for success upon arrival at their destination. Surprisingly, and despite several recent systematic reviews investigating the effects of jet lag and transmeridian travel on human physiology, there has been no systematic effort to address to what extent hypohydration is a (health, performance) risk to travelers embarking on long journeys. This narrative review summarizes the rationale and evidence for why the combination of fluid balance and long-haul flight remains a critically overlooked issue for traveling persons, be it for health, leisure, business, or in a sporting context. Upon review, there are few studies which have been conducted on actual traveling athletes, and those that have provide no real evidence of how the incidence rate, magnitude, or duration of acute dehydration may affect the general health or performance of elite athletes.
Association between Dairy Intake and Linear Growth in Chinese Pre-School Children
Authors: Duan Yifan , Pang Xuehong , Yang Zhenyu , Wang Jie , Jiang Shan , Bi Ye , Wang Shuxia , Zhang Huanmei , Lai Jianqiang
Published: August 2020

Stunting remains a major public health issue for pre-school children globally. Dairy product consumption is suboptimal in China. The aim of this study was to investigate the relationship between dairy intake and linear growth in Chinese pre-school children. A national representative survey (Chinese Nutrition and Health Surveillance) of children aged under 6 years was done in 2013. Stratified multistage cluster sampling was used to select study participants. A food frequency questionnaire was used to collect dietary information. We calculated height-for-age Z-scores (HAZs) and estimated stunting using the 2006 WHO growth standard. In total, 12,153 children aged two to four years old (24 to <60 months) were studied from 55 counties in 30 provinces in China. Approximately 39.2% (4759/12,153) of those children consumed dairy at least once per day, 11.9% (1450/12,153) consumed dairy at least once in the last week, and nearly half (48.9%, 5944/12,153) did not have any dairy in the last week. The HAZ was −0.15 ± 1.22 and the prevalence of stunting was 6.5% (785/12,153). The HAZ for children who consumed dairy at least once per day or per week was 0.11 points or 0.13 points higher than the children without dairy intake. The risk of stunting for children who consumed dairy at least once per day was 28% lower than the children without dairy intake in the last week, and the risk was similar between weekly dairy consumption and no dairy consumption (AOR: 1.03, 95% CI: 0.74–1.42) after adjusting for potential confounders, including socioeconomic characteristics, lifestyle, health status, and the intake frequency of other foods. Dairy intake was significantly associated with a higher HAZ and a lower risk of stunting for children aged 2–4 years old in China. The proportion of dairy intake was still low in Chinese pre-school children. The promotion of dairy consumption might be an effective and feasible measurement for improving linear growth in Chinese pre-school children.
The Association of Demographic Characteristics and Food Choice Motives with the Consumption of Functional Foods in Emerging Adults
Authors: Vorage Lieke , Wiseman Nicola , Graca Joana , Harris Neil
Published: August 2020

The functional food market is one of the fastest growing segments of the global food industry. The aims of this study were to understand the association of demographic characteristics and food choice motives (FCMs) with (a) attitudes toward functional foods and (b) consumption of functional foods in Australian emerging adults. Data were collected through a paper-based and online questionnaire completed by 370 young adults aged between 17 and 29 years. A binomial logistic regression was used to determine the association between demographic characteristics and FCMs with attitudes towards functional foods. The logistic regression model was statistically significant at χ2(11) = 48.310 (p < 0.001) and explained 18.1% of the variance in attitude towards functional food. Of the several predictors, only the FCMs natural content and weight control were statistically significant. A binomial logistic regression was also used to determine the association between demographic characteristics and FCMs with the consumption of functional foods. The logistic regression model was statistically significant at χ2(9) = 37.499 (p < 0.001) and explained 14.1% of the variance in functional food consumption. Of the eight predictors, three were statistically significant: living situation, natural content and health. Findings highlight that when targeting emerging adults, functional food companies could benefit from promoting the natural and health properties of their products. Furthermore, consumption can be increased by targeting the parents of emerging adults and by designing functional foods that attract emerging adults interested in controlling weight.
Fat-Free Mass Is Better Related to Serum Uric Acid Than Metabolic Homeostasis in Prader-Willi Syndrome
Authors: Marzullo Paolo , Mele Chiara , Minocci Alessandro , Mai Stefania , Scacchi Massimo , Sartorio Alessandro , Aimaretti Gianluca , Grugni Graziano
Published: August 2020

Background: Prader-Willi syndrome (PWS) is conventionally regarded as a model of genetic obesity carrying a metabolically healthier profile and fat compartmentalization than subjects with non-syndromic obesity. Serum uric acid (sUA) is a recognized surrogate marker of metabolic derangement. As no information is currently available on sUA levels in adults with PWS, we aimed to analyze sUA in a large cohort of adult patients with PWS in comparison to a control counterpart; secondly, we aimed to investigate the metabolic and non-metabolic determinants of sUA in PWS. Methods: A cross-sectional study was conducted on 89 consecutive adult patients with genetically confirmed PWS spanning a wide BMI range (17.2–56.7 kg/m2). As controls, 180 age-, sex- and BMI-matched healthy controls were included. sUA levels were analyzed in relation to the PWS status, metabolic variables, hormone status, body composition, and resting energy expenditure (REE). Bivariate correlation and multivariable regression studies were used to test for predictors of sUA in PWS. Results: Despite having similar BMI values, patients with PWS presented with higher FM (p < 0.0001), lower FFM (p < 0.0001) and REE values than controls (p < 0.0001). In PWS, sUA levels were non-significantly different between subjects with and without obesity (5.4 ± 1.3 vs. 4.9 ± 1.1 mg/dL, p = 0.09), and did not vary significantly in relation to genotype, sex steroid or GH replacement, as well as psychiatric treatments. Rates of hyperuricaemia (19.1% vs. 33.7%, p < 0.01) and absolute sUA levels were lower in patients with PWS compared to controls owing to significant differences between subgroups with obesity (5.5 ± 1.4 vs. 6.6 ± 1.6 mg/dL, p < 0.0001). In merged populations, sUA increased in parallel with age, BMI, FM, FFM, REE, glucolipid homeostasis, and inflammatory markers. In a separate analysis in PWS, however, sUA correlations with BMI, FM, and inflammatory markers were null. Stepwise multivariable regression analysis in the PWS group adjusted for karyotype, age, sex, FM, FFM, obesity, triglycerides, and HDL cholesterol, showed that sUA levels were independently associated with FFM (β = 0.35, p < 0.0001) and, albeit less significantly, with triglycerides (β = 0.23, p < 0.05). The introduction of height-normalized FFM (FFM index) in the regression model, however, abrogated the predictive role of FFM on sUA. Conclusions: FFM mass is a strong predictor of sUA. PWS is associated to lower sUA levels than controls likely due to genetic predisposition to different body composition and healthier metabolic phenotype. Further studies are warranted to assess purine metabolism and the clinical significance of the FFM index in PWS.
An Overview of Antibody Conjugated Polymeric Nanoparticles for Breast Cancer Therapy
Authors: Juan Alberto , Cimas Francisco J. , Bravo Iván , Pandiella Atanasio , Ocaña Alberto , Alonso-Moreno Carlos
Published: August 2020

Nanoparticles (NPs) are promising drug delivery systems (DDS) for identifying and treating cancer. Active targeting NPs can be generated by conjugation with ligands that bind overexpressed or mutant cell surface receptors on target cells that are poorly or not even expressed on normal cells. Receptor-mediated endocytosis of the NPs occurs and the drug is released inside the cell or in the surrounding tissue due to the bystander effect. Antibodies are the most frequently used ligands to actively target tumor cells. In this context, antibody-based therapies have been extensively used in HER2+ breast cancer. However, some patients inherently display resistance and in advanced stages, almost all eventually progress. Functionalized NPs through conjugation with antibodies appear to be a promising strategy to optimize targeted therapies due to properties related to biocompatibility, suitable delivery control and efficiency of functionalization. This review is focused on the different strategies to conjugate antibodies into polymeric NPs. Recent antibody conjugation approaches applied to the improvement of breast cancer therapy are highlighted in this review.
Verification of P-Glycoprotein Function at the Dermal Barrier in Diffusion Cells and Dynamic “Skin-On-A-Chip” Microfluidic Device
Authors: Bajza Ágnes , Kocsis Dorottya , Berezvai Orsolya , Laki András József , Lukács Bence , Imre Tímea , Iván Kristóf , Szabó Pál , Erdő Franciska
Published: August 2020

The efficacy of transdermal absorption of drugs and the irritation or corrosion potential of topically applied formulations are important areas of investigation in pharmaceutical, military and cosmetic research. The aim of the present experiments is to test the role of P-glycoprotein in dermal drug delivery in various ex vivo and in vitro platforms, including a novel microchip technology developed by Pázmány Péter Catholic University. A further question is whether the freezing of excised skin and age have any influence on P-glycoprotein-mediated dermal drug absorption. Two P-glycoprotein substrate model drugs (quinidine and erythromycin) were investigated via topical administration in diffusion cells, a skin-on-a-chip device and transdermal microdialysis in rat skin. The transdermal absorption of both model drugs was reduced by P-glycoprotein inhibition, and both aging and freezing increased the permeability of the tissues. Based on our findings, it is concluded that the process of freezing leads to reduced function of efflux transporters, and increases the porosity of skin. P-glycoprotein has an absorptive orientation in the skin, and topical inhibitors can modify its action. The defensive role of the skin seems to be diminished in aged individuals, partly due to reduced thickness of the dermis. The novel microfluidic microchip seems to be an appropriate tool to investigate dermal drug delivery.
Efficient Transfection of Large Plasmids Encoding HIV-1 into Human Cells—A High Potential Transfection System Based on a Peptide Mimicking Cationic Lipid
Authors: Janich Christopher , Ivanusic Daniel , Giselbrecht Julia , Janich Elena , Pinnapireddy Shashank Reddy , Hause Gerd , Bakowsky Udo , Langner Andreas , Wölk Christian
Published: August 2020

One major disadvantage of nucleic acid delivery systems is the low transfection or transduction efficiency of large-sized plasmids into cells. In this communication, we demonstrate the efficient transfection of a 15.5 kb green fluorescent protein (GFP)-fused HIV-1 molecular clone with a nucleic acid delivery system prepared from the highly potent peptide-mimicking cationic lipid OH4 in a mixture with the phospholipid DOPE (co-lipid). For the transfection, liposomes were loaded using a large-sized plasmid (15.5 kb), which encodes a replication-competent HIV type 1 molecular clone that carries a Gag-internal green fluorescent protein (HIV-1 JR-FL Gag-iGFP). The particle size and charge of the generated nanocarriers with 15.5 kb were compared to those of a standardized 4.7 kb plasmid formulation. Stable, small-sized lipoplexes could be generated independently of the length of the used DNA. The transfer of fluorescently labeled pDNA-HIV1-Gag-iGFP in HEK293T cells was monitored using confocal laser scanning microscopy (cLSM). After efficient plasmid delivery, virus particles were detectable as budding structures on the plasma membrane. Moreover, we observed a randomized distribution of fluorescently labeled lipids over the plasma membrane. Obviously, a significant exchange of lipids between the drug delivery system and the cellular membranes occurs, which hints toward a fusion process. The mechanism of membrane fusion for the internalization of lipid-based drug delivery systems into cells is still a frequently discussed topic.
Efficacy of Emu Oil Transfersomes for Local Transdermal Delivery of 4-OH Tamoxifen in the Treatment of Breast Cancer
Authors: Sundralingam Usha , Chakravarthi Srikumar , Radhakrishnan Ammu Kutty , Muniyandy Saravanan , Palanisamy Uma D.
Published: August 2020

Oral tamoxifen used in the prevention and treatment of ductal carcinoma in situ (DCIS) (estrogen-positive) patients has limited acceptance, due to its adverse side effects. The efficacy of tamoxifen is related to its major metabolite, 4-hydroxytamoxifen. Local transdermal therapy of 4-hydroxytamoxifen to the breast might avert the toxicity of oral tamoxifen, while maintaining efficacy. We aim to study the skin irritancy, as well as to evaluate the efficacy of the developed transfersome formulations, with/without emu oil, using a syngeneic mouse model of breast cancer. We also quantified tamoxifen/4-hydroxytamoxifen concentrations in blood plasma and performed histopathology. The skin irritancy test showed that the pure emu oil and transfersome formulations with or without the emu oil did not cause skin irritancy in the animals studied. A sensitive and specific LC–MS/MS method for the quantification of tamoxifen and 4-hydroxytamoxifen was developed and validated. Studies on tumor volume and necrosis (histopathology) using the breast cancer mouse model showed that the 4-OHT transfersomal formulations, with and without emu oil, showed comparable efficacy with that of orally administered tamoxifen. However, the transfersomal formulations, with and without emu oil, resulted in significantly lower (10.24 ± 0.07 and 32.45 ± 0.48 ng/mL, respectively) plasma concentrations of 4-hydroxytamoxifen, compared to the oral tamoxifen (TAMX) group (634.42 ± 7.54 ng/mL). This study demonstrated the potential use of emu oil in a local transdermal formulation for the treatment of breast cancer and its reduced adverse effects.
Preparation and Thermomechanical Properties of Ketone Mesogenic Liquid Crystalline Epoxy Resin Composites with Functionalized Boron Nitride
Authors: Lin Yi-Sheng , Hsu Steve Lien-Chung , Ho Tsung-Han , Jheng Li-Cheng , Hsiao Yu-Hsiang
Published: August 2020

In order to enhance the thermomechanical behaviors of epoxy molding compounds, the hexagonal boron nitride (h-BN) fillers were incorporated in a ketone mesogenic liquid crystalline epoxy (K–LCE) matrix to prepare a high-performance epoxy composites. The h-BN was modified by surface coupling agent 3-aminopropyltriethoxysilane (APTES). The grafting of silane molecules onto the surface of BN fillers improved the compatibility and homogeneous dispersion state of BN fillers in the K–LCE matrix with a strong interface interaction. The surface-modified BN fillers were characterized using Fourier transform infrared spectroscopy. The thermomechanical properties and morphologies of K–LCE/BN composites loading with different contents of modified BN fillers, ranging from 0.50 to 5.00 wt%, were investigated. These results show that modified BN fillers uniformly dispersed in K–LCE matrix, contributing to the enhancement in storage modulus, glass transition temperatures, impact strength and reduction in the coefficient of thermal expansion (CTE). The thermal stability and char yield of the K–LCE/BN composites were increased by increasing the amount of modified BN fillers and the thermal decomposition temperatures of composites were over 370 °C. The thermal conductivity of the K–LCE/BN composites was up to 0.6 W/m·K, for LC epoxy filled with 5.00-wt%-modified BN fillers. Furthermore, the K–LCE/BN composites have excellent thermal and mechanical properties compared to those of the DGEBA/BN composites.
Ciprofloxacin-Collagen-Based Materials with Potential Oral Surgical Applications
Authors: Ioan Daniel-Cristian , Rău Ileana , Albu Kaya Mădălina Georgiana , Radu Nicoleta , Bostan Marinela , Zgârian Roxana Gabriela , Tihan Graţiela Teodora , Dinu-Pîrvu Cristina-Elena , Lupuliasa Alina , Ghica Mihaela Violeta
Published: August 2020

We report in this paper the synthesis and characterization of a new collagen-based material. This material was obtained in a spongy form and was functionalized with an antibiotic, ciprofloxacin. The targeted applications of these kind of materials concern the post-operative prophylaxis. The in vitro tests (antimicrobial, cytotoxic, drug release) showed that sponges with a concentration of 0.75 g of ciprofloxacin per gram of collagen could be beneficial for the desired applications.
Rheological Investigation of Relaxation Behavior of Polycarbonate/Acrylonitrile-Butadiene-Styrene Blends
Authors: Seo Jae Sik , Jeon Ho Tak , Han Tae Hee
Published: August 2020

The rheological properties of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends with various blend ratios are investigated at different temperatures to determine the shear dependent chain motions in a heterogeneous blend system. At low frequency levels under 0.1 rad/s, the viscosity of the material with a blend ratio of 3:7 (PC:ABS) is higher than that of pure ABS polymer. As the temperature increases, the viscosities of ABS-rich blends increase rather than decrease, whereas PC-rich blends exhibit decrease in viscosity. Results from the time sweep measurements indicate that ordered structures of PC and the formation and breakdown of internal network structures of ABS polymer occur simultaneously in the blend systems. Newly designed sequence test results show that the internal structures formed between PC and ABS polymers are dominant at low shear conditions for the blend ratio of 3:7 and effects of structural change and the presence of polybutadiene (PBD) become dominant at high shear conditions for pure ABS. The results of yield stress and relaxation time for PC/ABS blends support this phenomenon. The specimen with a blend ratio of 3:7 exhibited the highest value of yield stress at high temperature among others, which implies that the internal structure become stronger at higher temperature. The heterogeneity of ABS-rich blends increases whereas that of PC-rich blends decreases as temperature increases.
Self-Healing EPDM Rubbers with Highly Stable and Mechanically-Enhanced Urea-Formaldehyde (UF) Microcapsules Prepared by Multi-Step In Situ Polymerization
Authors: Jeoung Hyeong-Jun , Kim Kun Won , Chang Yong Jun , Jung Yong Chae , Ku Hyunchul , Oh Kyung Wha , Choi Hyung-Min , Chung Jae Woo
Published: August 2020

The mechanically-enhanced urea-formaldehyde (UF) microcapsules are developed through a multi-step in situ polymerization method. Optical microscope (OM) and field emission scanning electron microscope (FE-SEM) prove that the microcapsules, 147.4 μm in diameter with a shell thickness of 600 nm, are well-formed. From 1H-nuclear magnetic resonance (1H-NMR) analysis, we found that dicyclopentadiene (DCPD), a self-healing agent encapsulated by the microcapsules, occupies ca. 40.3 %(v/v) of the internal volume of a single capsule. These microcapsules are mixed with EPDM (ethylene-propylene-diene-monomer) and Grubbs’ catalyst via a solution mixing method, and universal testing machine (UTM) tests show that the composites with mechanically-enhanced microcapsules has ca. 47% higher toughness than the composites with conventionally prepared UF microcapsules, which is attributed to the improved mechanical stability of the microcapsule. When the EPDM/microcapsule rubber composites are notched, Fourier-transform infrared (FT-IR) spectroscopy shows that DCPD leaks from the broken microcapsule to the damaged site and flows to fill the notched valley, and self-heals as it is cured by Grubbs’ catalyst. The self-healing efficiency depends on the capsule concentration in the EPDM matrix. However, the self-healed EPDM/microcapsule rubber composite with over 15 wt% microcapsule shows an almost full recovery of the mechanical strength and 100% healing efficiency.
Optimal Non-Convex Combined Heat and Power Economic Dispatch via Improved Artificial Bee Colony Algorithm
Authors: Rabiee Abbas , Jamadi Mohammad , Mohammadi-Ivatloo Behnam , Ahmadian Ali
Published: August 2020

It is well accepted that combined heat and power (CHP) generation can increase the efficiency of power and heat generation at the same time. With the increasing penetration of CHPs, determination of economic dispatch of power and heat becomes more complex and challenging. The CHP economic dispatch (CHPED) problem is a challenging optimization problem due to non-linearity and non-convexity in both objective function and constraints. Hence, in this paper a novel meta-heuristic algorithm, namely improved artificial bee colony (IABC) algorithm is proposed to solve the CHPED problem. The valve-point effects, power losses as well as the feasible operation region of CHP units are taken into account in the proposed CHPED problem model and the optimal dispatch of power/heat outputs of CHP units is determined via the proposed IABC algorithm. The proposed algorithm is applied on three test systems, in which two of them are large-scale CHPED benchmarks. The obtained results and comprehensive comparison with available methods, demonstrate the superiority of the proposed algorithm for dealing with non-convex and constrained CHPED problem.
Morphological Differentiation of Streptomyces clavuligerus Exposed to Diverse Environmental Conditions and Its Relationship with Clavulanic Acid Biosynthesis
Authors: Yepes-García Jeferyd , Caicedo-Montoya Carlos , Pinilla Laura , Toro León F. , Ríos-Estepa Rigoberto
Published: August 2020

Clavulanic acid (CA) is a potent inhibitor of class A β-lactamase enzymes produced by Streptomyces clavuligerus (S. clavuligerus) as a defense mechanism. Due to its industrial interest, the process optimization is under continuous investigation. This work aimed at identifying the potential relationship that might exist between S. clavuligerus ATCC 27064 morphology and CA biosynthesis. For this, modified culture conditions such as source, size, and age of inoculum, culture media, and geometry of fermentation flasks were tested. We observed that high density spore suspensions (1 × 107 spores/mL) represent the best inoculum source for S. clavuligerus cell suspension culture. Further, we studied the life cycle of S. clavuligerus in liquid medium, using optic, confocal, and electron microscopy; results allowed us to observe a potential relationship that might exist between the accumulation of CA and the morphology of disperse hyphae. Reactor geometries that increase shear stress promote smaller pellets and a quick disintegration of these in dispersed secondary mycelia, which begins the pseudosporulation process, thus easing CA accumulation. These outcomes greatly contribute to improving the understanding of antibiotic biosynthesis in the Streptomyces genus.
Hegemonic Religions, Majoritarianism, and the Legitimate Limits of Governmental Religious Bias
Authors: Perez Nahshon
Published: August 2020

Recent major court decisions and important political events in democratic countries demonstrated, explicitly or implicitly, governmental bias in favor of a given religious tradition. Some prominent cases include the Swiss minarets ban of 2009, the 2011 ECtHR decision in the Lautsi case (Lautsi vs. Italy (2011) Application No. 30814/06) as well as the recent decision of the U.S. Supreme Court in the American Legion v. American Humanist Association case (No. 17-1717, 588 U.S. (2019), legitimizing the usage of public funds to maintain the Maryland Bladensburg Cross. Major scholars, such as David Miller, Joseph Weiler, and Cecile Laborde suggested a novel, detailed argument, justifying the rights of majorities in given countries to structure religion–state institutions following the majority religion, as long as the rights of minority communities and individuals are upheld. The aim of the current article is twofold: First, in section one, we shall attentively define the ‘religious majoritarian approach’ (RMA), that upholds the presumed rights of majorities to structure religion–state institutions according to the majority-religion. The core features of the RMA will be defined, and three pre-conditions the model requires in order to ‘fit’ any given case will be described (‘shared understanding’; ‘tradition’ and ‘democratic challenge’). Second, in section two, once we have a precise understanding of the RMA, to suggest a critical discussion of this approach. For the sake of the argument, and in order to enable a proper conversation with RMA proponents, this article will not assume that the RMA is illegitimate to begin with, as would be the case if our starting point would have been some version of liberal-neutrality. Rather, the main critical argument will be that the positive case for the RMA is under-studied. In ‘positive’, it would mean here the arguments for the RMA, rather than focusing on the mere permissibility of it. After all, if a government wishes to adopt a certain policy, it is not sufficient to argue that it does not violate certain moral or legal standards, rather, the citizens of said country would like to know what is the utility of this policy? What does it attempt to achieve? How is it justified? The ‘positive’ examination of the RMA will be divided into two categories: The first, examining the merits and plausibility of the pre-conditions and the arguments made by RMA scholars themselves. Therefore, in cases in which they are not met, the RMA should be rejected according to the RMA itself. The second is to confront RMA models with further critiques and difficulties, focusing on concerns raised regarding the entanglement between religion and state that the RMA entails, from the perspective of both religion and government. Somewhat schematically, we can label the former critique as ‘internal’, and the latter as ‘external’.
Hedging on Betting Markets
Authors: Axén Gustav , Cortis Dominic
Published: August 2020

The possibility to use hedging strategies is an often neglected aspect in the literature on prediction/betting markets, as most papers assume that bettors will bet according to their beliefs about the probability of the outcome of the event, as opposed to the direction in which the odds will move. This ignores strategies that try to buy low and sell high through exploiting price changes, which is an important aspect to incorporate to fully understand market pricing. In this paper, we derive the key mathematical results in using hedging strategies through taking opposite positions to an initial bet after the market odds have changed and show that a profit can be made without explicitly speculating on the probability of the outcomes. We also discuss two sources of inefficiency that can arise when using hedging strategies in practice: (i) the need to pay a fee when using a betting exchange and (ii) the lack of a lay option (the possibility to bet against outcomes) on some markets, and we analyze how they affect the possibilities to hedge. Many of the results have interesting properties when expressed in terms of the naive probabilities implied by the odds.
Application of Advanced Machine Learning Algorithms to Assess Groundwater Potential Using Remote Sensing-Derived Data
Authors: Kamali Maskooni Ehsan , Naghibi Seyed Amir , Hashemi Hossein , Berndtsson Ronny
Published: August 2020

Groundwater (GW) is being uncontrollably exploited in various parts of the world resulting from huge needs for water supply as an outcome of population growth and industrialization. Bearing in mind the importance of GW potential assessment in reaching sustainability, this study seeks to use remote sensing (RS)-derived driving factors as an input of the advanced machine learning algorithms (MLAs), comprising deep boosting and logistic model trees to evaluate their efficiency. To do so, their results are compared with three benchmark MLAs such as boosted regression trees, k-nearest neighbors, and random forest. For this purpose, we firstly assembled different topographical, hydrological, RS-based, and lithological driving factors such as altitude, slope degree, aspect, slope length, plan curvature, profile curvature, relative slope position, distance from rivers, river density, topographic wetness index, land use/land cover (LULC), normalized difference vegetation index (NDVI), distance from lineament, lineament density, and lithology. The GW spring indicator was divided into two classes for training (434 springs) and validation (186 springs) with a proportion of 70:30. The training dataset of the springs accompanied by the driving factors were incorporated into the MLAs and the outputs were validated by different indices such as accuracy, kappa, receiver operating characteristics (ROC) curve, specificity, and sensitivity. Based upon the area under the ROC curve, the logistic model tree (87.813%) generated similar performance to deep boosting (87.807%), followed by boosted regression trees (87.397%), random forest (86.466%), and k-nearest neighbors (76.708%) MLAs. The findings confirm the great performance of the logistic model tree and deep boosting algorithms in modelling GW potential. Thus, their application can be suggested for other areas to obtain an insight about GW-related barriers toward sustainability. Further, the outcome based on the logistic model tree algorithm depicts the high impact of the RS-based factor, such as NDVI with 100 relative influence, as well as high influence of the distance from river, altitude, and RSP variables with 46.07, 43.47, and 37.20 relative influence, respectively, on GW potential.
Comparison of Harmonic Analysis of Time Series (HANTS) and Multi-Singular Spectrum Analysis (M-SSA) in Reconstruction of Long-Gap Missing Data in NDVI Time Series
Authors: Ghafarian Malamiri Hamid Reza , Zare Hadi , Rousta Iman , Olafsson Haraldur , Izquierdo Verdiguier Emma , Zhang Hao , Mushore Terence Darlington
Published: August 2020

Monitoring vegetation changes over time is very important in dry areas such as Iran, given its pronounced drought-prone agricultural system. Vegetation indices derived from remotely sensed satellite imageries are successfully used to monitor vegetation changes at various scales. Atmospheric dust as well as airborne particles, particularly gases and clouds, significantly affect the reflection of energy from the surface, especially in visible, short and infrared wavelengths. This results in imageries with missing data (gaps) and outliers while vegetation change analysis requires integrated and complete time series data. This study investigated the performance of HANTS (Harmonic ANalysis of Time Series) algorithm and (M)-SSA ((Multi-channel) Singular Spectrum Analysis) algorithm in reconstruction of wide-gap of missing data. The time series of Normalized Difference Vegetation Index (NDVI) retrieved from Landsat TM in combination with 250m MODIS NDVI time image products are used to simulate and find periodic components of the NDVI time series from 1986 to 2000 and from 2000 to 2015, respectively. This paper presents the evaluation of the performance of gap filling capability of HANTS and M-SSA by filling artificially created gaps in data using Landsat and MODIS data. The results showed that the RMSEs (Root Mean Square Errors) between the original and reconstructed data in HANTS and M-SSA algorithms were 0.027 and 0.023 NDVI value, respectively. Further, RMSEs among 15 NDVI images extracted from the time series artificially and reconstructed by HANTS and M-SSA algorithms were 0.030 and 0.025 NDVI value, respectively. RMSEs of the original and reconstructed data in HANTS and M-SSA algorithms were 0.10 and 0.04 for time series 6, respectively. The findings of this study present a favorable option for solving the missing data challenge in NDVI time series.
A Novel Deep Forest-Based Active Transfer Learning Method for PolSAR Images
Authors: Qin Xingli , Yang Jie , Zhao Lingli , Li Pingxiang , Sun Kaimin
Published: August 2020

The information extraction of polarimetric synthetic aperture radar (PolSAR) images typically requires a great number of training samples; however, the training samples from historical images are less reusable due to the distribution differences. Consequently, there is a significant manual cost to collecting training samples when processing new images. In this paper, to address this problem, we propose a novel active transfer learning method, which combines active learning and the deep forest model to perform transfer learning. The main idea of the proposed method is to gradually improve the performance of the model in target domain tasks with the increase of the levels of the cascade structure. More specifically, in the growing stage, a new active learning strategy is used to iteratively add the most informative target domain samples to the training set, and the augmented features generated by the representation learning capability of the deep forest model are used to improve the cross-domain representational capabilities of the feature space. In the filtering stage, an effective stopping criterion is used to adaptively control the complexity of the model, and two filtering strategies are used to accelerate the convergence of the model. We conducted experiments using three sets of PolSAR images, and the results were compared with those of four existing transfer learning algorithms. Overall, the experimental results fully demonstrated the effectiveness and robustness of the proposed method.
Optimization of Sensors to be Used in a Voltammetric Electronic Tongue Based on Clustering Metrics
Authors: Sarma Munmi , Romero Noelia , Cetó Xavier , Valle Manel del
Published: August 2020

Herein we investigate the usage of principal component analysis (PCA) and canonical variate analysis (CVA), in combination with the F factor clustering metric, for the a priori tailored selection of the optimal sensor array for a given electronic tongue (ET) application. The former allows us to visually compare the performance of the different sensors, while the latter allows us to numerically assess the impact that the inclusion/removal of the different sensors has on the discrimination ability of the ET. The proposed methodology is based on the measurement of a pure stock solution of each of the compounds under study, and the posterior analysis by PCA/CVA with stepwise iterative removal of the sensors that demote the clustering when retained as part of the array. To illustrate and assess the potential of such an approach, the quantification of paracetamol, ascorbic acid, and uric acid mixtures were chosen as the study case. Initially, an array of eight different electrodes was considered, from which an optimal array of four sensors was derived to build the quantitative ANN model. Finally, the performance of the optimized ET was benchmarked against the results previously reported for the analysis of the same mixtures, showing improved performance.
Burnout Syndrome, Engagement and Goal Orientation in Teachers from Different Educational Stages
Authors: Usán Supervía Pablo , Salavera Bordás Carlos
Published: August 2020

Teaching is a demanding occupation, physically, mentally, and emotionally, that, depending on personal characteristics, can have a negative impact on health and personal wellbeing, which can affect the way professors work and teach in schools. The aim of this study is to analyze the relationship between burnout, engagement, and goal orientation in a sample of teachers from different educational stages. The sample comprised 576 teachers from different schools, both male (N = 244; 42.36%) and female (N = 332; 57.63%) aged between 21 and 65 years (M = 38.55; DT = 12.15). The instruments used were the Maslach Burnout Inventory–General Survey (MBI-GS), the Work Engagement Scale (UWES) and the Perception of Success Questionnaire (POSQ). The results revealed that task orientation presents a significant correlation with engagement and self-efficacy, and negative correlation with burnout, in line with adaptive behaviors, and that ego orientation is correlated with engagement and commitment. It is concluded that both forms of goal orientation have a positive effect on teacher commitment and that they help to prevent burnout syndrome and also that self-efficacy plays a role in determining goal orientation in teachers in their work assignments.