bluuebunny/crossref_metadata_2025 huggingface dataset:
Quick, Easy, and Economic Mineralogical Studies of Flooded Chalk for EOR Experiments Using Raman Spectroscopy
Authors: Borromeo Laura , Egeland Nina , Wetrhus Minde Mona , Zimmermann Udo , Andò Sergio , Madland Merete , Korsnes Reidar
Published: May 2018

Understanding the chalk-fluid interactions and the associated mineralogical and mechanical alterations on a sub-micron scale are major goals in Enhanced Oil Recovery. Mechanical strength, porosity, and permeability of chalk are linked to mineral dissolution that occurs during brine injections, and affect the reservoir potential. This paper presents a novel “single grain” methodology to recognize the varieties of carbonates in rocks and loose sediments: Raman spectroscopy is a non-destructive, quick, and user-friendly technique representing a powerful tool to identify minerals down to 1 µm. An innovative working technique for oil exploration is proposed, as the mineralogy of micron-sized crystals grown in two flooded chalk samples (Liége, Belgium) was successfully investigated by Raman spectroscopy. The drilled chalk cores were flooded with MgCl2 for ca. 1.5 (Long Term Test) and 3 years (Ultra Long Term Test) under North Sea reservoir conditions (Long Term Test: 130 °C, 1 PV/day, 9.3 MPa effective stress; Ultra Long Term Test: 130 °C, varying between 1–3 PV/day, 10.4 MPa effective stress). Raman spectroscopy was able to identify the presence of recrystallized magnesite along the core of the Long Term Test up to 4 cm from the injection surface, down to the crystal size of 1–2 µm. In the Ultra Long Term Test core, the growth of MgCO3 affected nearly the entire core (7 cm). In both samples, no dolomite or high-magnesium calcite secondary growth could be detected when analysing 557 and 90 Raman spectra on the Long and Ultra Long Term Test, respectively. This study can offer Raman spectroscopy as a breakthrough tool in petroleum exploration of unconventional reservoirs, due to its quickness, spatial resolution, and non-destructive acquisition of data. These characteristics would encourage its use coupled with electron microscopes and energy dispersive systems or even electron microprobe studies.
Kinetic Basis of the Bifunctionality of SsoII DNA Methyltransferase
Authors: Timofeyeva Nadezhda A. , Ryazanova Alexandra Yu. , Norkin Maxim V. , Oretskaya Tatiana S. , Fedorova Olga S. , Kubareva Elena A.
Published: May 2018

Type II restriction–modification (RM) systems are the most widespread bacterial antiviral defence mechanisms. DNA methyltransferase SsoII (M.SsoII) from a Type II RM system SsoII regulates transcription in its own RM system in addition to the methylation function. DNA with a so-called regulatory site inhibits the M.SsoII methylation activity. Using circular permutation assay, we show that M.SsoII monomer induces DNA bending of 31° at the methylation site and 46° at the regulatory site. In the M.SsoII dimer bound to the regulatory site, both protein subunits make equal contributions to the DNA bending, and both angles are in the same plane. Fluorescence of TAMRA, 2-aminopurine, and Trp was used to monitor conformational dynamics of DNA and M.SsoII under pre-steady-state conditions by stopped-flow technique. Kinetic data indicate that M.SsoII prefers the regulatory site to the methylation site at the step of initial protein–DNA complex formation. Nevertheless, in the presence of S-adenosyl-l-methionine, the induced fit is accelerated in the M.SsoII complex with the methylation site, ensuring efficient formation of the catalytically competent complex. The presence of S-adenosyl-l-methionine and large amount of the methylation sites promote efficient DNA methylation by M.SsoII despite the inhibitory effect of the regulatory site.
Involvement of CYP4F2 in the Metabolism of a Novel Monophosphate Ester Prodrug of Gemcitabine and Its Interaction Potential In Vitro
Authors: Wang Yedong , Li Yuan , Lu Jia , Qi Huixin , Cheng Isabel , Zhang Hongjian
Published: May 2018

Compound-3 is an oral monophosphate prodrug of gemcitabine. Previous data showed that Compound-3 was more potent than gemcitabine and it was orally active in a tumor xenograft model. In the present study, the metabolism of Compound-3 was investigated in several well-known in vitro matrices. While relatively stable in human and rat plasma, Compound-3 demonstrated noticeable metabolism in liver and intestinal microsomes in the presence of NADPH and human hepatocytes. Compound-3 could also be hydrolyzed by alkaline phosphatase, leading to gemcitabine formation. Metabolite identification using accurate mass- and information-based scan techniques revealed that Compound-3 was subjected to sequential metabolism, forming alcohol, aldehyde and carboxylic acid metabolites, respectively. Results from reaction phenotyping studies indicated that cytochrome P450 4F2 (CYP4F2) was a key CYP isozyme involved in Compound-3 metabolism. Interaction assays suggested that CYP4F2 activity could be inhibited by Compound-3 or an antiparasitic prodrug pafuramidine. Because CYP4F2 is a key CYP isozyme involved in the metabolism of eicosanoids and therapeutic drugs, clinical relevance of drug-drug interactions mediated via CYP4F2 inhibition warrants further investigation.
Compounds Identification in Semen Cuscutae by Ultra-High-Performance Liquid Chromatography (UPLCs) Coupled to Electrospray Ionization Mass Spectrometry
Authors: Zhang Ying , Xiong Hui , Xu Xinfang , Xue Xue , Liu Mengnan , Xu Shuya , Liu Huan , Gao Yan , Zhang Hui , Li Xiangri
Published: May 2018

Semen Cuscutae is commonly used in traditional Chinese medicine and contains a series of compounds such as flavonoids, chlorogenic acids and lignans. In this study, we identified different kinds of compositions by ultra-high-performance liquid chromatography (UPLC) coupled to electrospray ionization mass spectrometry (MS). A total of 45 compounds were observed, including 20 chlorogenic acids, 23 flavonoids and 2 lignans. 23 of them are reported for the first time including 6-O-caffeoyl-β-glucose, 3-O-(4′-O-Caffeoylglucosyl) quinic acid, etc. Their structures were established by retention behavior, extensive analyses of their MS spectra and further determined by comparison of their MS data with those reported in the literature. As chlorogenic acids and flavonoids are phenolic compounds that are predominant in Semen Cuscutae, in conclusion, phenolic compounds are the major constituents of Semen Cuscutae.
Identification of Insecticidal Constituents from the Essential Oil from the Aerial Parts Stachys riederi var. japonica
Authors: Quan Meirong , Liu Qi Zhi , Liu Zhi Long
Published: May 2018

The essential oil of Stachys riederi var. japonica (Family: Lamiaceae) was extracted by hydrodistillation and determined by GC and GC-MS. A total of 40 components were identified, representing 96.01% of the total oil composition. The major compounds in the essential oil were acetanisole (15.43%), anisole (9.43%), 1,8-cineole (8.07%), geraniol (7.89%), eugenol (4.54%), caryophyllene oxide (4.47%), caryophyllene (4.21%) and linalool (4.07%). Five active constituents (acetanisole, anisole, 1,8-cineole, eugenol and geraniol) were identified by bioactivity-directed fractionation. The essential oil possessed fumigant toxicity against maize weevils (Sitophilus zeamais) and booklice (Liposcelis bostrychophila), with LC50 values of 15.0 mg/L and 0.7 mg/L, respectively. Eugenol and anisole exhibited stronger fumigant toxicity than the oil against booklice. 1,8-Cineole showed stronger toxicity, and anisole as well as eugenol exhibited the same level of fumigant toxicity as the essential oil against maize weevils. The essential oil also exhibited contact toxicity against S. zeamais adults and L. bostrychophila, with LC50 values of 21.8 µg/adult and 287.0 µg/cm2, respectively. The results indicated that the essential oil of S. riederi var. japonica and its isolates show potential as fumigants, and for their contact toxicity against grain storage insects.
Interrelationships among Fatty Acid Composition, Staphyloxanthin Content, Fluidity, and Carbon Flow in the Staphylococcus aureus Membrane
Authors: Tiwari Kiran , Gatto Craig , Wilkinson Brian
Published: May 2018

Fatty acids play a major role in determining membrane biophysical properties. Staphylococcus aureus produces branched-chain fatty acids (BCFAs) and straight-chain saturated fatty acids (SCSFAs), and can directly incorporate exogenous SCSFAs and straight-chain unsaturated fatty acids (SCUFAs). Many S. aureus strains produce the triterpenoid pigment staphyloxanthin, and the balance of BCFAs, SCSFAs and staphyloxanthin determines membrane fluidity. Here, we investigated the relationship of fatty acid and carotenoid production in S. aureus using a pigmented strain (Pig1), its carotenoid-deficient mutant (Pig1ΔcrtM) and the naturally non-pigmented Staphylococcus argenteus that lacks carotenoid biosynthesis genes and is closely related to S. aureus. Fatty acid compositions in all strains were similar under a given culture condition indicating that staphyloxanthin does not influence fatty acid composition. Strain Pig1 had decreased membrane fluidity as measured by fluorescence anisotropy compared to the other strains under all conditions indicating that staphyloxanthin helps maintain membrane rigidity. We could find no evidence for correlation of expression of crtM and fatty acid biosynthesis genes. Supplementation of medium with glucose increased SCSFA production and decreased BCFA and staphyloxanthin production, whereas acetate-supplementation also decreased BCFAs but increased staphyloxanthin production. We believe that staphyloxanthin levels are influenced more through metabolic regulation than responding to fatty acids incorporated into the membrane.
Identification and Expression of miRNAs Related to Female Flower Induction in Walnut (Juglans regia L.)
Authors: Zhou Li , Quan Shaowen , Xu Hang , Ma Li , Niu Jianxin
Published: May 2018

Flower induction is an essential stage in walnut (Juglans regia L.) trees, directly affecting yield, yield stability, fruit quality and commodity value. The objective of this study was to identify miRNAs related to female flower induction via high-throughput sequencing and bioinformatics analysis. A total of 123 miRNAs were identified including 51 known miRNAs and 72 novel miRNAs. Differential expression was observed in 19 of the known miRNAs and 34 of the novel miRNAs. Twelve miRNAs were confirmed by RT-qPCR. A total of 1339 target genes were predicted for the differentially expressed miRNAs. The functions of 616 of those target genes had been previously annotated. The target genes of the differentially expressed miRNAs included: (i) floral homeotic protein APETALA 2 (AP2) and ethylene-responsive transcription factor RAP2-7 which were targeted by jre-miRn69; (ii) squamosa promoter-binding protein 1 (SPB1) and various SPLs (squamosa promoter-binding-like protein) which were targeted by jre-miR157a-5p; (iii) various hormone response factors which were targeted by jre-miR160a-5p (ARF18) and jre-miR167a-5p (ARF8) and (iv) transcription factor SCL6 which was targeted by jre-miR171b-3p, jre-miRn46 and jre-miRn49. The KEGG pathway analysis of the target genes indicated that the differentially expressed miRNAs were mainly enriched to ubiquitin mediated proteolysis, RNA degradation and various carbohydrate metabolism pathways. Many miRNAs were detected in J. regia during female flower induction. Some miRNAs (jre-miR157a-5p, jre-miR160a-5p, jre-miR167a-5p, miR171b-3p jre-miRn69 and jre-miRn49) were involved in female flower induction. The results of this experiment will contribute valuable information for further research about the function of miRNAs in flower induction of J. regia and other fruit trees.
Characterization of Cyclodextrin/Volatile Inclusion Complexes: A Review
Authors: Kfoury Miriana , Landy David , Fourmentin Sophie
Published: May 2018

Cyclodextrins (CDs) are a family of cyclic oligosaccharides that constitute one of the most widely used molecular hosts in supramolecular chemistry. Encapsulation in the hydrophobic cavity of CDs positively affects the physical and chemical characteristics of the guests upon the formation of inclusion complexes. Such a property is interestingly employed to retain volatile guests and reduce their volatility. Within this scope, the starting crucial point for a suitable and careful characterization of an inclusion complex is to assess the value of the formation constant (Kf), also called stability or binding constant. This task requires the application of the appropriate analytical method and technique. Thus, the aim of the present paper is to give a general overview of the main analytical tools used for the determination of Kf values for CD/volatile inclusion complexes. This review emphasizes on the advantages, inconvenients and limits of each applied method. A special attention is also dedicated to the improvement of the current methods and to the development of new techniques. Further, the applicability of each technique is illustrated by a summary of data obtained from the literature.
Optimisation of Ethanol-Reflux Extraction of Saponins from Steamed Panax notoginseng by Response Surface Methodology and Evaluation of Hematopoiesis Effect
Authors: Hu Yupiao , Cui Xiuming , Zhang Zejun , Chen Lijuan , Zhang Yiming , Wang Chengxiao , Yang Xiaoyan , Qu Yuan , Xiong Yin
Published: May 2018

The present study aims to optimize the ethanol-reflux extraction conditions for extracting saponins from steamed Panax notoginseng (SPN). Four variables including the extraction time (0.5–2.5 h), ethanol concentration (50–90%), water to solid ratio (W/S, 8–16), and times of extraction (1–5) were investigated by using the Box-Behnken design response surface methodology (BBD-RSM). For each response, a second-order polynomial model with high R2 values (>0.9690) was developed using multiple linear regression analysis and the optimum conditions to maximize the yield (31.96%), content (70.49 mg/g), and antioxidant activity (EC50 value of 0.0421 mg/mL) for saponins extracted from SPN were obtained with a extraction time of 1.51 h, ethanol concentration of 60%, extraction done 3 times, and a W/S of 10. The experimental values were in good consistency with the predicted ones. In addition, the extracted SPN saponins could significantly increase the levels of blood routine parameters compared with the model group (p < 0.01) and there was no significant difference in the hematopoiesis effect between the SPN group and the SPN saponins group, of which the dose was 15 times lower than the former one. It is suggested that the SPN saponins extracted by the optimized method had similar functions of “blood tonifying” at a much lower dose.
A Case-Control Study of the Association between Vitamin D Levels and Gastric Incomplete Intestinal Metaplasia
Authors: Singh Kevin , Gandhi Soren , Batool Raffat
Published: May 2018

Aim: Low circulating vitamin D levels are associated with gastric adenocarcinoma, but whether vitamin D levels are associated with premalignant gastric mucosal changes is unknown. Here, we determined associations between vitamin D levels and gastric incomplete intestinal metaplasia, a known gastric adenocarcinoma risk factor. Methods: This was a retrospective, unmatched, case-control study comparing serum 25-hydroxyvitamin D levels among subjects with gastric incomplete intestinal metaplasia (cases; n = 103) and those without gastric incomplete intestinal metaplasia (controls; n = 216). The 25-hydroxyvitamin D levels were categorized as normal (30–100 ng/dL), vitamin D insufficiency (VDi; 20–29 ng/dL), and vitamin D deficiency (VDd; <20 ng/dL). Using multivariable logistic regression, odds ratios (ORs) were calculated and adjusted to age, gender, ethnicity, body mass index, history of hypertension or diabetes mellitus, and timing of vitamin D collection to assess associations between 25-hydroxyvitamin D levels and gastric incomplete intestinal metaplasia. Results: A majority of case subjects were male, Hispanic, and did not have hypertension or diabetes mellitus. The average serum 25-hydroxyvitamin D level was significantly lower in the intestinal metaplasia group than the control group (19.7 ng/dL vs. 34.7 ng/dL; p < 0.001). Hypovitaminosis D was more common in subjects with incomplete intestinal metaplasia in a multivariable regression model (OR 54.1, 95% CI 21.8–134.3; p < 0.001). VDd (OR 129.0, 95% CI 43.7–381.2; p < 0.001) and VDi (OR 31.0, 95% CI 11.9–80.3; p < 0.001) were more common in patients with incomplete intestinal metaplasia than healthy subjects, with VDd slightly more prevalent than VDi (OR 4.0, 95% CI 1.7–9.6; p < 0.001). Conclusions: Vitamin D deficiency and insufficiency are more common in patients with gastric incomplete intestinal metaplasia than healthy subjects and may play a role in the development of premalignant phenotypes related to gastric adenocarcinoma.
Quality of Life in Patients with Gluten Neuropathy: A Case-Controlled Study
Authors: Zis Panagiotis , Sarrigiannis Ptolemaios Georgios , Rao Dasappaiah Ganesh , Hadjivassiliou Marios
Published: May 2018

Background: Gluten neuropathy (GN) is defined as an otherwise idiopathic peripheral neuropathy in the presence of serological evidence of gluten sensitivity (positive native gliadin antibodies and/or transglutaminase or endomysium antibodies). We aimed to compare the quality of life (QoL) of GN patients with that of control subjects and to investigate the effects of a gluten-free diet (GFD) on the QoL. Methods: All consecutive patients with GN attending a specialist neuropathy clinic were invited to participate. The Overall Neuropathy Limitations Scale (ONLS) was used to assess the severity of the neuropathy. The 36-Item Short Form Survey (SF-36) questionnaire was used to measure participants’ QoL. A strict GFD was defined as effectively being able to eliminate all circulating gluten sensitivity-related antibodies. Results: Fifty-three patients with GN and 53 age- and gender-matched controls were recruited. Compared to controls, GN patients showed significantly worse scores in the physical functioning, role limitations due to physical health, energy/fatigue, and general health subdomains of the SF-36. After adjusting for age, gender, and disease severity, being on a strict GFD correlated with better SF-36 scores in the pain domain of the SF-36 (beta 0.317, p = 0.019) and in the overall health change domain of the SF-36 (beta 0.306, p = 0.017). Conclusion: In GN patients, physical dysfunctioning is the major determinant of poor QoL compared to controls. Routine checking of the elimination of gluten sensitivity-related antibodies that results from a strict GFD should be encouraged, as such elimination ameliorates the overall pain and health scores, indicating a better QoL.
Vitamin K Antagonists and Cognitive Decline in Older Adults: A 24-Month Follow-Up
Authors: Brangier Antoine , Ferland Guylaine , Rolland Yves , Gautier Jennifer , Féart Catherine , Annweiler Cedric
Published: May 2018

Vitamin K participates in brain physiology. This study aimed to determine whether using vitamin K antagonists (VKAs), which interfere with the vitamin K cycle, were (i) cross-sectionally associated with altered cognitive performance, and (ii) independent predictors of cognitive changes in older adults over 24 months. Information was collected on the use of VKAs (i.e., warfarin, acenocoumarol, and fluindione) among 378 geriatric outpatients (mean, 82.3 ± 5.6 years; 60.1% female). Global cognitive performance and executive functions were assessed with Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) scores, respectively, at baseline and after 12 and 24 months of follow-up. Age, gender, body mass index, mean arterial pressure, disability, gait speed, comorbidities, atrial fibrillation, stroke, carotid artery stenosis, leukoaraiosis grade on computed tomography (CT) scan, psychoactive drugs, antidementia drugs, blood-thinning drugs (i.e., anticoagulants other than VKAs, antiplatelet medications), serum creatinine levels, and vitamin B12 concentrations were considered as potential confounders. Using VKAs was associated with lower (i.e., worse) FAB score at baseline (adjusted β = −2.1, p = 0.026), and with a decrease in FAB score after 24 months (adjusted β = −203.6%, p = 0.010), but not after 12 months (p = 0.659). Using VKAs was not associated with any change in MMSE score at baseline (p = 0.655), after 12 months (p = 0.603), or after 24 months (p = 0.201). In conclusion, we found more severe executive dysfunction at baseline and incident executive decline over 24 months among geriatric patients using VKAs, when compared with their counterparts.
Evaluation of Band-Selective HSQC and HMBC: Methodological Validation on the Cyclosporin Cyclic Peptide and Application for Poly(3-hydroxyalkanoate)s Stereoregularity Determination
Authors: Caytan Elsa , Ligny Romain , Carpentier Jean-François , Guillaume Sophie M.
Published: May 2018

Band-selective (bs) HSQC, improving spectral resolution by restriction of the heteronuclear dimension without inducing spectral folding, has been recently used for polymer tacticity determination. Herein is reported an evaluation of various bs-HSQC and bs-HMBC sequences, first from a methodological point of view (selectivity, dependence to INEPT interpulse delay or relaxation delay), using the cyclic peptide cyclosporin selected as a model compound, and then from an applicative approach, comparing tacticity determined from bs-HSQC and bs-HMBC experiments to the one obtained from 1D 13C{1H} on poly(3-hydroxyalkanoate)s samples. For HSQC sequences, the 13C selectivity scheme consisting in substituting a 13C broadband refocalization by a selective one revealed itself problematic, with unwanted aliased signals, whereas the insertion of double pulsed field gradients spin-echo (DPFGSE) or the use of opposite sign gradients bracketing a selective refocalization gave satisfactory results. Determination of the probability of syndiotactic enchainments, Ps, by bs-HSQC is fully consistent and no precision loss was observed when decreasing acquisition time (37 min vs. 106 min for 1D 13C{1H}). Bs-HMBC, although not straightforwardly applicable for tacticity determination, could provide (after a calibration step) an alternative for compounds of which only 13C carbonyl signals are resolved enough for discriminating between syndiotactic and isotactic configurations.
Multifunctional Polymer Nanocomposites Reinforced by Aligned Carbon Nanomaterials
Authors: Wu Shuying , Peng Shuhua , Wang Chun H.
Published: May 2018

Carbon nanomaterials such as carbon black (CB), carbon nanotubes (CNTs), and graphene have demonstrated significant potential as fillers to improve the electrical, thermal, and mechanical properties of polymers and their fiber-reinforced polymer composites. The level of improvement has been found to depend significantly on the degree of alignment of carbon nanomaterials. Due to the very small scale and complex interactions of carbon nanomaterials with polymers and structural fibers, alignment in a given direction has been a major challenge. Over the past decade, considerable effort has been devoted to developing effective strategies to align carbon nanomaterials in polymer matrices. However, significant technological challenges remain, and there is still a lack of understanding of the alignment mechanisms and their effects on the properties of polymers and composites. This paper reviews in situ alignment techniques including shear deformation, mechanical stretching, electrospinning, and application of an external magnetic or electric field, and ex situ techniques including using vertically grown CNTs or graphene. This review particularly focuses on physical mechanisms underpinning the magnetic or electric field-induced alignment and theoretical analyses that describe the different motions occurring and the major parameters controlling alignment. Moreover, this review highlights the recent research findings of the effects of alignment on the properties of polymer nanocomposites. The outlook towards the challenges and opportunities in this field are also discussed in this review.
Preparation of Functionalized Magnetic Fe3O4@Au@polydopamine Nanocomposites and Their Application for Copper(II) Removal
Authors: Li Yanxia , Huang Lu , He Wenxuan , Chen Yiting , Lou Benyong
Published: May 2018

Polydopamine (PDA) displays many striking properties of naturally occurring melanin in optics, electricity, and biocompatibility. Another valuable feature of polydopamine lies in its chemical structure that incorporates many functional groups such as amine, catechol and imine. In this study, a nanocomposite of magnetic Fe3O4@Au@polydopamine nanopaticles (Fe3O4@Au@ PDA MNPs) was synthesized. Carboxyl functionalized Fe3O4@Au nanoparticles (NPs) were successfully embedded in a layer of PDA through dopamine oxypolymerization in alkaline solution. Through the investigation of adsorption behavior to Cu(II), combined with high sensitive electrochemical detection, the as-prepared magnetic nanocomposites (MNPs) have been successfully applied in the separation and analysis of Cu(II). The experimental parameters of temperature, Cu(II) concentration and pH were optimized. Results showed that the as-prepared MNPs can reach saturation adsorption after adsorbing 2 h in neutral environment. Furthermore, the as-prepared MNPs can be easily regenerated by temperature control and exhibits a good selectivity compared to other metal ions. The prepared Fe3O4@Au@PDA MNPs are expected to act as a kind of adsorbent for Cu(II) deep removal from contaminated waters.
Polymer Interface Molecular Engineering for E-Textiles
Authors: Zhu Chuang , Li Yi , Liu Xuqing
Published: May 2018

Wearable electronics, regarded as the next generation of conventional textiles, have been an important concept in the study of e-textiles. Conductive fibres are the upstreaming of e-textiles and have witnessed the booming development in recent years. However, little work has focused on improving the wash ability and durability of conductive fibres. As a new approach to manufacturing conductive fibres, Polymer Interface Molecular Engineering (PIME) is starting to be employed recently, to build up an interfacial layer on polymeric fibre surfaces; this interfacial layer services as a platform to anchor catalysts for the following metal Electroless Deposition (ELD). The designed interfacial layer significantly increases adhesion between polymeric substrates and coating metal layers, to improve the durability of e-textiles. This review highlights recent research into different molecular and architectural design strategies, and its potential application for wearable electronics. Further challenges and opportunities in this field are also discussed critically.
Precise Synthesis, Properties, and Structures of Cyclic Poly(ε-caprolactone)s
Authors: Xiang Li , Ryu Wonyeong , Kim Heesoo , Ree Moonhor
Published: May 2018

Cyclic PCL (c-PCL) has drawn great attention from academia and industry because of its unique, unusual structure and property characteristics due to the absence of end groups in addition to the biocompatibility and biodegradability of its linear analogue. As a result of much research effort, several synthetic methods have been developed to produce c-PCLs so far. Their chain, morphology and property characteristics were investigated even though carried out on a very limited basis. This feature article reviews the research progress made in the synthesis, morphology, and properties of c-PCL; all results and their pros and cons are discussed in terms of purity and molecular weight distribution in addition to the cyclic topology effect. In addition, we attempted to synthesize a series of c-PCL products of high purity by using intramolecular azido-alkynyl click cyclization chemistry and subsequent precise and controlled separation and purification; and their thermal degradation and phase transitions were investigated in terms of the cyclic topology effect.
Determination of Pressure Dependence of Polymer Phase Transitions by pVT Analysis
Authors: Pionteck Jürgen
Published: May 2018

Glass transitions, melting, crystallization, and the isotropization of polymers are connected with changes in the density, respectively the specific volume (Vsp), which can be analyzed by dilatometric methods. Here, the pressure dependence of such transitions is determined by pressure volume temperature (pVT) analysis for different thermoplastic polymers in the pressure range of 10 to 200 MPa, and the temperature range from room temperature to 350 °C. The values for ambient pressure are extrapolated. It is shown that polymer transitions always increase with pressure, and that the melting temperature and glass transition temperature are nearly linearly dependent on pressure. This information, as well as the observed density changes with pressure and temperature, is very important for the processing of thermoplastics, including their simulation, as well as for the thermodynamic interpretations of the transition’s nature.
Impact of Metaheuristic Iteration on Artificial Neural Network Structure in Medical Data
Authors: Salman Ihsan , Ucan Osman N. , Bayat Oguz , Shaker Khalid
Published: May 2018

Medical data classification is an important factor in improving diagnosis and treatment and can assist physicians in making decisions about serious diseases by collecting symptoms and medical analyses. In this work, hybrid classification optimization methods such as Genetic Algorithm (GA), Particle Swam Optimization (PSO), and Fireworks Algorithm (FWA), are proposed for enhancing the classification accuracy of the Artificial Neural Network (ANN). The enhancement process is tested through two experiments. First, the proposed algorithms are applied on five benchmark medical data sets from the repository of the University of California in Irvine (UCI). The model with the best results is then used in the second experiment, which focuses on tuning the parameters of the selected algorithm by choosing a different number of iterations in ANNs with different numbers of hidden layers. Enhanced ANN with the three optimization algorithms are tested on biological gene sequence big dataset obtained from The Cancer Genome Atlas (TCGA) repository. GA and FWA are statistically significant but PSO was statistically not, and GA overcame PSO and FWA in performance. The methodology is successful and registers improvements in every step, as significant results are obtained.
Religious Knowledge, Ineffability and Gender
Authors: Baiasu Roxana
Published: May 2018

The issue of ineffability constitutes a significant challenge in the philosophy of religion. In this paper, I first argue that it is difficult to see how the traditional approach, which I call ‘the metaphysical approach’, can address this challenge. I consider then a post-metaphysical approach inspired by Wittgenstein which does look more promising in dealing with the ineffable. Finally, I argue that there are, however, new challenges that have to be taken into account; in particular, I focus here on the problem raised by contemporary feminist philosophers of the gendering of religious knowledge.
Using Cutting-Edge Tree-Based Stochastic Models to Predict Credit Risk
Authors: Halteh Khaled , Kumar Kuldeep , Gepp Adrian
Published: May 2018

Credit risk is a critical issue that affects banks and companies on a global scale. Possessing the ability to accurately predict the level of credit risk has the potential to help the lender and borrower. This is achieved by alleviating the number of loans provided to borrowers with poor financial health, thereby reducing the number of failed businesses, and, in effect, preventing economies from collapsing. This paper uses state-of-the-art stochastic models, namely: Decision trees, random forests, and stochastic gradient boosting to add to the current literature on credit-risk modelling. The Australian mining industry has been selected to test our methodology. Mining in Australia generates around $138 billion annually, making up more than half of the total goods and services. This paper uses publicly-available financial data from 750 risky and not risky Australian mining companies as variables in our models. Our results indicate that stochastic gradient boosting was the superior model at correctly classifying the good and bad credit-rated companies within the mining sector. Our model showed that ‘Property, Plant, & Equipment (PPE) turnover’, ‘Invested Capital Turnover’, and ‘Price over Earnings Ratio (PER)’ were the variables with the best explanatory power pertaining to predicting credit risk in the Australian mining sector.
On the Moments and the Distribution of Aggregate Discounted Claims in a Markovian Environment
Authors: Li Shuanming , Lu Yi
Published: May 2018

This paper studies the moments and the distribution of the aggregate discounted claims (ADCs) in a Markovian environment, where the claim arrivals, claim amounts, and forces of interest (for discounting) are influenced by an underlying Markov process. Specifically, we assume that claims occur according to a Markovian arrival process (MAP). The paper shows that the vector of joint Laplace transforms of the ADC occurring in each state of the environment process by any specific time satisfies a matrix-form first-order partial differential equation, through which a recursive formula is derived for the moments of the ADC occurring in certain states (a subset). We also study two types of covariances of the ADC occurring in any two subsets of the state space and with two different time lengths. The distribution of the ADC occurring in certain states by any specific time is also investigated. Numerical results are also presented for a two-state Markov-modulated model case.
Application of Thermal and Phenological Land Surface Parameters for Improving Ecological Niche Models of Betula utilis in the Himalayan Region
Authors: Bobrowski Maria , Bechtel Benjamin , Böhner Jürgen , Oldeland Jens , Weidinger Johannes , Schickhoff Udo
Published: May 2018

Modelling ecological niches across vast distribution ranges in remote, high mountain regions like the Himalayas faces several data limitations, in particular nonavailability of species occurrence data and fine-scale environmental information of sufficiently high quality. Remotely sensed data provide key advantages such as frequent, complete, and long-term observations of land surface parameters with full spatial coverage. The objective of this study is to evaluate modelled climate data as well as remotely sensed data for modelling the ecological niche of Betula utilis in the subalpine and alpine belts of the Himalayan region covering the entire Himalayan arc. Using generalized linear models (GLM), we aim at testing factors controlling the species distribution under current climate conditions. We evaluate the additional predictive capacity of remotely sensed variables, namely remotely sensed topography and vegetation phenology data (phenological traits), as well as the capability to substitute bioclimatic variables from downscaled numerical models by remotely sensed annual land surface temperature parameters. The best performing model utilized bioclimatic variables, topography, and phenological traits, and explained over 69% of variance, while models exclusively based on remotely sensed data reached 65% of explained variance. In summary, models based on bioclimatic variables and topography combined with phenological traits led to a refined prediction of the current niche of B. utilis, whereas models using solely climate data consistently resulted in overpredictions. Our results suggest that remotely sensed phenological traits can be applied beneficially as supplements to improve model accuracy and to refine the prediction of the species niche. We conclude that the combination of remotely sensed land surface temperature parameters is promising, in particular in regions where sufficient fine-scale climate data are not available.
Developing an Acoustic Sensing Yarn for Health Surveillance in a Military Setting
Authors: Hughes-Riley Theodore , Dias Tilak
Published: May 2018

Overexposure to high levels of noise can cause permanent hearing disorders, which have a significant adverse effect on the quality of life of those affected. Injury due to noise can affect people in a variety of careers including construction workers, factory workers, and members of the armed forces. By monitoring the noise exposure of workers, overexposure can be avoided and suitable protective equipment can be provided. This work focused on the creation of a noise dosimeter suitable for use by members of the armed forces, where a discrete dosimeter was integrated into a textile helmet cover. In this way the sensing elements could be incorporated very close to the ears, providing a highly representative indication of the sound level entering the body, and also creating a device that would not interfere with military activities. This was achieved by utilising commercial microelectromechanical system microphones integrated within the fibres of yarn to create an acoustic sensing yarn. The acoustic sensing yarns were fully characterised over a range of relevant sound levels and frequencies at each stage in the yarn production process. The yarns were ultimately integrated into a knitted helmet cover to create a functional acoustic sensing helmet cover prototype.
Automated Geo/Co-Registration of Multi-Temporal Very-High-Resolution Imagery
Authors: Han Youkyung , Oh Jaehong
Published: May 2018

For time-series analysis using very-high-resolution (VHR) multi-temporal satellite images, both accurate georegistration to the map coordinates and subpixel-level co-registration among the images should be conducted. However, applying well-known matching methods, such as scale-invariant feature transform and speeded up robust features for VHR multi-temporal images, has limitations. First, they cannot be used for matching an optical image to heterogeneous non-optical data for georegistration. Second, they produce a local misalignment induced by differences in acquisition conditions, such as acquisition platform stability, the sensor’s off-nadir angle, and relief displacement of the considered scene. Therefore, this study addresses the problem by proposing an automated geo/co-registration framework for full-scene multi-temporal images acquired from a VHR optical satellite sensor. The proposed method comprises two primary steps: (1) a global georegistration process, followed by (2) a fine co-registration process. During the first step, two-dimensional multi-temporal satellite images are matched to three-dimensional topographic maps to assign the map coordinates. During the second step, a local analysis of registration noise pixels extracted between the multi-temporal images that have been mapped to the map coordinates is conducted to extract a large number of well-distributed corresponding points (CPs). The CPs are finally used to construct a non-rigid transformation function that enables minimization of the local misalignment existing among the images. Experiments conducted on five Kompsat-3 full scenes confirmed the effectiveness of the proposed framework, showing that the georegistration performance resulted in an approximately pixel-level accuracy for most of the scenes, and the co-registration performance further improved the results among all combinations of the georegistered Kompsat-3 image pairs by increasing the calculated cross-correlation values.
Development of a Cloud Computing-Based Pier Type Port Structure Stability Evaluation Platform Using Fiber Bragg Grating Sensors
Authors: Jo Byung Wan , Jo Jun Ho , Khan Rana Muhammad Asad , Kim Jung Hoon , Lee Yun Sung
Published: May 2018

Structure Health Monitoring is a topic of great interest in port structures due to the ageing of structures and the limitations of evaluating structures. This paper presents a cloud computing-based stability evaluation platform for a pier type port structure using Fiber Bragg Grating (FBG) sensors in a system consisting of a FBG strain sensor, FBG displacement gauge, FBG angle meter, gateway, and cloud computing-based web server. The sensors were installed on core components of the structure and measurements were taken to evaluate the structures. The measurement values were transmitted to the web server via the gateway to analyze and visualize them. All data were analyzed and visualized in the web server to evaluate the structure based on the safety evaluation index (SEI). The stability evaluation platform for pier type port structures involves the efficient monitoring of the structures which can be carried out easily anytime and anywhere by converging new technologies such as cloud computing and FBG sensors. In addition, the platform has been successfully implemented at “Maryang Harbor” situated in Maryang-Meyon of Korea to test its durability.
A Statistical Approach to Detect Jamming Attacks in Wireless Sensor Networks
Authors: Osanaiye Opeyemi , Alfa Attahiru S. , Hancke Gerhard P.
Published: May 2018

Wireless Sensor Networks (WSNs), in recent times, have become one of the most promising network solutions with a wide variety of applications in the areas of agriculture, environment, healthcare and the military. Notwithstanding these promising applications, sensor nodes in WSNs are vulnerable to different security attacks due to their deployment in hostile and unattended areas and their resource constraints. One of such attacks is the DoS jamming attack that interferes and disrupts the normal functions of sensor nodes in a WSN by emitting radio frequency signals to jam legitimate signals to cause a denial of service. In this work we propose a step-wise approach using a statistical process control technique to detect these attacks. We deploy an exponentially weighted moving average (EWMA) to detect anomalous changes in the intensity of a jamming attack event by using the packet inter-arrival feature of the received packets from the sensor nodes. Results obtained from a trace-driven simulation show that the proposed solution can efficiently and accurately detect jamming attacks in WSNs with little or no overhead.
Anthropometric and Physical Performance of Youth Handball Players: The Role of the Relative Age
Authors: Camacho-Cardenosa Alba , Camacho-Cardenosa Marta , González-Custodio Adrián , Martínez-Guardado Ismael , Timón Rafael , Olcina Guillermo , Brazo-Sayavera Javier
Published: May 2018

Background: The relative age effect is essential throughout all of the talent selection processes in sports, especially during adolescence, which leaves fewer athletes within each cohort that are born late in the selected year. The aim of the present study was to examine the role of relative age in anthropometric and physical performance characteristics of youth handball players by gender. Methods: The sample that was selected included 47 participants (male n = 23, female n = 24). The data collection included anthropometric, body compositions parameters, and physical performance levels. Results: There was a significantly higher representation of players in the first semester in comparison with the second semester, for all of the gender groups, except for the selected male players. In males, statistically significant differences were found in height, sitting height, weight, wingspan, arm and leg circumferences, and in throws speed (in support and in suspension) between those players that were born in the first and second semester. Conclusion: The results confirmed an effect of relative age in the players born in 2002 that were selected to participate in the Spanish Championship, which was different for males and females. In spite of this effect, which only appeared in females, significant differences in the anthropometric and physical conditions appeared in the male players.
Analysing Emotions and Social Skills in Physical Education
Authors: Cañabate Dolors , Martínez Georgina , Rodríguez David , Colomer Jordi
Published: May 2018

The purpose of this study is to explore the assessment of emotions and social skills of sixth-year primary education students in a physical education (PE) teaching unit. Two instruments of analysis are used: the GES (Games and Emotion Scale) to evaluate emotions, and an ad-hoc questionnaire to measure the social skills of 21 students in their sixth year of primary education. The data analysis was carried out using a generalised estimating equation model (GEE), taking into account the correlation between the different scores of the same subject and the asymmetry of the data. The results show that positive emotions (happiness and joy) are significantly more highly evaluated than negative (fear, anger, and sadness) and ambiguous (surprise) emotions throughout all of the PE sessions.
A Life Cycle Explanation of Cooperative Longevity
Authors: Cook Michael L.
Published: May 2018

A micro analytical, interdisciplinary informed framework is presented to postulate why and how some cooperatives endure for long periods of time. This five-phase framework was developed through an extended research process employing inductive and deductive approaches. The paper concludes that cooperative longevity is associated with multiple factors, primarily among them, ability to adapt and ameliorate frictions and subgroup factions. This adaptability leads to multi “life cycles”. Cooperative multi life cycle regeneration is facilitated by a learned and embedded process called “cooperative genius”.
Polycentric Development and the Role of Urban Polycentric Planning in China’s Mega Cities: An Examination of Beijing’s Metropolitan Area
Authors: Liu Zhen , Liu Shenghe
Published: May 2018

An emerging polycentric spatial structure in China’s mega cities has been confirmed in the literature, but few studies have addressed the linkage between the change in spatial structure and urban development policies. Using Beijing as a case study, this paper examines the role of urban polycentric planning in the polycentric evolution process from a morphological perspective. We observed that urban polycentric planning significantly promoted the emergence of a polycentric urban form in Beijing’s metropolitan area from 2001 to 2010. Firstly, most of the planned subcenters were identified as real employment subcenters by a relative threshold method in 2001 and 2010 and comprised the majority of the employment subcenters. Secondly, the planned subcenters significantly increased their employment share and influence on employment and population distribution from 2001 to 2010, and their performances referring to these aspects were much better than the unplanned subcenters. Thus, our findings provide evidence that changes in urban spatial structure can be strongly affected by urban development policies, although it is determined by market forces in theory.