bluuebunny/crossref_metadata_2025 huggingface dataset:
Topological insulators and the Kane–Mele invariant: Obstruction and localization theory
Authors: Bunk Severin , Szabo Richard J.
Published: November 2019

We present homotopy theoretic and geometric interpretations of the Kane–Mele invariant for gapped fermionic quantum systems in three dimensions with time-reversal symmetry. We show that the invariant is related to a certain 4-equivalence which lends it an interpretation as an obstruction to a block decomposition of the sewing matrix up to non-equivariant homotopy. We prove a Mayer–Vietoris Theorem for manifolds with [Formula: see text]-actions which intertwines Real and [Formula: see text]-equivariant de Rham cohomology groups, and apply it to derive a new localization formula for the Kane–Mele invariant. This provides a unified cohomological explanation for the equivalence between the discrete Pfaffian formula and the known local geometric computations of the index for periodic lattice systems. We build on the relation between the Kane–Mele invariant and the theory of bundle gerbes with [Formula: see text]-actions to obtain geometric refinements of this obstruction and localization technique. In the preliminary part we review the Freed–Moore theory of band insulators on Galilean spacetimes with emphasis on geometric constructions, and present a bottom-up approach to time-reversal symmetric topological phases.
Adaptive observation control for synchronization of coronary artery time-delay systems
Authors: Guo Jie , Zhao Zhanshan , Zhang Jing , Ding Gang
Published: November 2019

This paper investigates novel adaptive observation control for synchronization of uncertain chaotic coronary artery system (CCAS). Novel adaptive observers are developed to obtain the estimated system states of uncertain CCAS which has unknown parameters. By utilizing the adaptive observers and controller we proposed, the adaptation of unknown parameters has been achieved and the asymptotic stability of the synchronization error as well as the estimation errors are guaranteed. For the purpose of further reducing the conservatism, new Lyapunov Krasovskii functions (LKFs) which maintain more system states have been constructed in terms of Wirtinger-based inequality, a new double integral inequality and improved reciprocally convex inequality. Using [Formula: see text] control to ensure robust performance of CCAS which has unknown parameters and external disturbance. The adaptive observer gain matrices and controller gain matrix could be obtained by employing a decoupling approach. The effectiveness of this control methodology has been illustrated by a numerical simulation result.
Lump and interaction solutions to linear PDEs in 2+1 dimensions via symbolic computation
Authors: Ma Wen-Xiu
Published: November 2019

The aim of this paper is to show that there exist lump solutions and interaction solutions to linear partial differential equations in 2[Formula: see text]+[Formula: see text]1 dimensions. Through symbolic computations with Maple, we exhibit a great variety of exact solutions to a class of (2[Formula: see text]+[Formula: see text]1)-dimensional linear partial differential equations, and present a specific example which possesses lump, lump-kink and lump-soliton solutions. This supplements the study on lump, rogue wave and breather solutions and their interaction solutions to nonlinear integrable equations.
Quarter mode rectangular cavity-based perfect metamaterial absorber in the terahertz region
Authors: Lu Xiaojie , Xiao Zhongyin , Chen Mingming
Published: November 2019

In this work, we present the analysis and design of a perfect metamaterial absorber (MA) based on quarter mode rectangular cavity in the terahertz region. This structure is consisted of a metal plate where three different size quarter mode rectangular cavities are vertically placed on. Based on rectangular-cavity-theory, a formula is proposed to calculate the resonant frequency, which provides a guidance for designing MAs of such type. In terms of normal incidence, the simulated results show that the MA has three resonance points on 4.1301 THz, 4.6051 THz and 5.1088 THz, respectively, which is in good agreement with the calculated results. Furthermore, we present the distribution of E-field in the cavity and use the standing wave theory to explain the physical mechanism of the perfect absorption. These results verify the application of resonant cavities in the field of MA.
Machine Learning Techniques for Assisted Reproductive Technology: A Review
Authors: Ranjini K. , Suruliandi A. , Raja S. P.
Published: November 2019

Infertility is becoming a public health issue in almost all countries. Assisted Reproductive Technology (ART) is considered as a method of last resort for treating infertility. The treatment of ART is highly expensive and painful, and also the probability of success is low since the success is affected by a large number of variables. Researchers are now trying to identify patterns comprising significant variables, their impact on success, and the interdependence of different variables to enumerate the status of the patient and to support the doctors and biologists to prescribe treatment to improve the probability of success of ART. Machine learning technique is a tool that is used by various researchers in the field of ART to identify the interlink between the variables. The objective of this review paper is to find the appliance of machine learning techniques in ART and to find further enrichment needed for future research. From the literature, it is found that some research works were done using machine learning techniques to predict ART outcome. On analyzing the reviews qualitatively and quantitatively, it is understood that various classifiers are used for ART outcome prediction but they are trained using limited amount of static data collected from fertility centers. The exact prediction of ART outcome may be improved by training the classifier with large amount of dynamic data. But building such a classifier is difficult by the already existing techniques. This may be made possible by introducing Big Data Analytics in ART.
MULTI-LEVEL PERSPECTIVE TO FACILITATE SUSTAINABLE TRANSITIONS — A PATHWAY FOR GERMAN OEMS TOWARDS ELECTRIC VEHICLES
Authors: KRÄTZIG OLIVER , FRANZKOWIAK VALERIA , SICK NATHALIE
Published: November 2019

Sustainable transitions within industrial branches are a complex problem since they involve emerging technologies, as well as cultural, market and policy-related changes. Recent studies emphasise the need for analytical approaches that not only do justice to this complexity by reflecting relevant trends and determinants, but also reveal insights that are intuitive enough to be implemented without major effort. Aiming at addressing this trade-off, we pursue a strategic analytical procedure that links external factors from multi-level perspective and internal, company-specific dynamic capabilities. We draw on expert interviews and subsequent qualitative analytical evaluation to obtain insights regarding individual motives, visions and boundary conditions of actors from the German automotive industry. Our contribution is both conceptually and practically important, as it unveils manifestations of significant dynamic capabilities and provides recommendations for change managers and policy makers leading to successful, sustainable transition in the automotive industry.
The Three-factor Model and China’s Multiple Stock Markets
Authors: Han Shi-Zhuan , Zhang Li , Han Guang-Yu , Wang Lei
Published: November 2019

This paper aims at discussing the applicability of the three-factor model in China’s multiple security markets. The monthly returns of Shenzhen Main Board Market, Shanghai Stock Market, GEM Securities Market and Small and Medium Board Securities Market from January 2012 to December 2016 are selected as samples. The following conclusions are drawn: the three-factor model is applicable in Shenzhen Main Board Market, that is, the change of stock return is proportional to market factor, book-to-market ratio factor, and inversely proportional to scale factor. Moreover, in terms of the explanatory power of the change of stock return, the market factor is the highest, the scale factor is the second, and the book-to-market ratio factor is the lowest. But in the other three markets, the two-factors model that excludes the ratio of book market value can explain the change of stock return better. In addition, the explanatory power of market factor is better than scale factor.
China’s Belt and Road Initiative 2.0
Authors: Cao Jiahan
Published: November 2019

As China’s Belt and Road Initiative (BRI) quickly evolves into an updated version for realizing high-quality development, its long-term success will increasingly depend on how well it can earn international legitimacy and credibility. Since sustainability is a critical source of credibility for the BRI, it is necessary to move the BRI forward by amplifying its role as a development agenda and tapping its potential to support global sustainable development and facilitate implementation of the United Nations’ 2030 Agenda for Sustainable Development (2030 Agenda) through delivering more public goods to other developing countries. The BRI projects designed to strengthen infrastructure inter-connectivity can greatly fit the developmental needs of countries along the routes and expedite their achievement of sustainable development goals (SDGs), both explicitly and implicitly. Besides, the growing alignment between the BRI and the 2030 Agenda will generate more strengths and opportunities for China to be recognized as an indispensable player in international development cooperation, enhance the capacity of the BRI to manage environmental, social and governance risks in host countries, promote social cohesion and inclusiveness along the routes, and ultimately transcend short-term economic and political interests for China to win the hearts and minds of other stakeholders involved in the BRI.
Toward the Unification of Physics and Number Theory
Authors: Irwin Klee
Published: November 2019

This paper introduces the notion of simplex-integers and shows how, in contrast to digital numbers, they are the most powerful numerical symbols that implicitly express the information of an integer and its set theoretic substructure. A geometric analogue to the primality test is introduced: when [Formula: see text] is prime, it divides [Formula: see text] for all [Formula: see text]. The geometric form provokes a novel hypothesis about the distribution of prime-simplexes that, if solved, may lead to a proof of the Riemann hypothesis. Specifically, if a geometric algorithm predicting the number of prime simplexes within any bound [Formula: see text]-simplex or associated [Formula: see text] lattice is discovered, a deep understanding of the error factor of the prime number theorem would be realized — the error factor corresponding to the distribution of the non-trivial zeta zeros, which might be the mysterious link between physics and the Riemann hypothesis [D. Schumayer and D. A. W. Hutchinson, Colloquium: Physics of the Riemann hypothesis, Rev. Mod. Phys. 83 (2011) 307]. It suggests how quantum gravity and particle physicists might benefit from a simplex-integer-based quasicrystal code formalism. An argument is put forth that the unifying idea between number theory and physics is code theory, where reality is information theoretic and 3-simplex integers form physically realistic aperiodic dynamic patterns from which space, time and particles emerge from the evolution of the code syntax.
Illiberals and Autocrats Unite to Craft a New World Media Order
Authors: Dorsey James M.
Published: November 2019

Underlying global efforts to counter fake news, psychological warfare and manipulation of public opinion is a far more fundamental battle: the global campaign by civilizationalists, illiberals, autocrats and authoritarians to create a new world media order that would reject freedom of the press and reduce the fourth estate to scribes and propaganda outlets.

The effort appears to have no limits. Its methods range from seeking to reshape international standards defining freedom of expression and the media; the launch and/or strengthening of government-controlled global, regional, national and local media in markets around the world; government acquisition of stakes in privately-owned media; advertising in independent media dependent on advertising revenue; funding of think-tanks; demonization; coercion; repression; and even assassination.

The effort to create a new media world order is closely linked to attempts to a battle between liberals and non-liberals over concepts of human rights, the roll-out of massive Chinese surveillance systems in China and beyond and a contest between the United States and China for dominance of the future of technology.

The stakes in these multiple battles could not be higher. They range from basic human and minority rights to issues of transparency, accountability and privacy, human rights, the role of the fourth estate as an independent check on power, freedom of expression and safeguards for human and physical dignity.

The battles are being waged in an environment in which a critical mass of world leaders appears to have an unspoken consensus on the principles of governance that should shape a new world order. Men like Xi Jinping, Vladimir Putin, Recep Tayyip Erdoğan, Victor Orbán, Benjamin Netanyahu, Mohammed bin Salman, Mohammed bin Zayed, Narendra Modi, Rodrigo Duterte, Jair Bolsonaro, Win Myint and Donald J. Trump have all to varying degrees diluted the concepts of human rights and undermined freedom of the press. If anything, it is this tacit understanding among the world’s foremost leaders that in shaping a new world order constitutes the greatest threat to liberal values.
Consensus Tracking of Fractional‐Order Multiagent Systems via Fractional‐Order Iterative Learning Control
Authors: Lv Shuaishuai , Pan Mian , Li Xungen , Ma Qi , Lan Tianyi , Li Bingqiang , Cai Wenyu
Published: November 2019

In this work, the consensus problem of fractional‐order multiagent systems with the general linear model of fixed topology is studied. Both distributed PDα‐type and Dα‐type fractional‐order iterative learning control (FOILC) algorithms are proposed. Here, a virtual leader is introduced to generate the desired trajectory, fixed communication topology is considered, and only a subset of followers can access the desired trajectory. The convergence conditions are proved using graph theory, fractional calculus, and λ norm theory. The theoretical analysis shows that the output of each agent completely tracks the expected trajectory in a limited time as the iteration number increases for both PDα‐type and Dα‐type FOILC algorithms. Extensive numerical simulations are given to demonstrate the feasibility and effectiveness.
Analysis of the Sedimentation Characteristics of Ultrafine Tailings Based on an Orthogonal Experiment
Authors: Li Chang-hong , Shi Yue-qi , Liu Peng , Guo Ning
Published: November 2019

Due to continuous improvements in the beneficiation process, the size of tailings has decreased. In many mines, more than 50% of the total tailings are finer than 74 μm. Ultrafine tailings exhibit a slow settling velocity and uneven settling, which pose new challenges to the safety and stability of tailings dams. In this paper, ultrafine iron tailings from the Makeng Iron Mine in Longyan City, Fujian Province, were used as the research object. A four-factor, three-level orthogonal test method was used to study the sedimentation characteristics of ultrafine tailings with four common curing agent materials, including polyacrylamide, polyaluminum chloride, polyaluminum sulfate, and polyferric sulfate. The results show that when the pulp concentration is 30%, the polyacrylamide is cationic and the molecular weight is 10 million, the optimal content of the flocculant is 3‰, the optimum dose of the polyaluminum chloride with a content of 28 is 0.1‰, the optimum dose of polyaluminum sulfate is 1‰, and the optimum dose of polymeric ferric sulfate is 1‰. When the flocculant is mixed according to the proportion of 2‰ polyacrylamide, 0.05‰ polyaluminum chloride, 1‰ polyaluminum sulfate, and 1.0‰ polyferric sulfate, the sedimentation speed of the ultrafine tailings is fast, and the supernatant liquid is clear. The results of multivariate nonlinear regression analysis of the sedimentation curve show that the primary and secondary factors affecting sedimentation are polyacrylamide > polyaluminum sulfate > polyaluminum chloride > polyferric sulfate. When the optimal ratio is applied, the cohesion (c) of ultrafine tailings increases from 27 kPa to 68.75 kPa and the internal friction angle (φ) increases from 25.53° to 27.53°, which shows that the shear strength improves and the stability of the tailings dam increases. The economic analysis of the composite flocculant with the optimal ratio shows that the flocculant with the optimal proportion has an obvious economic advantage over polyacrylamide alone.
An Experimental Study of the Uniaxial Failure Behaviour of Rock‐Coal Composite Samples with Pre‐existing Cracks in the Coal
Authors: Chen Shaojie , Ge Yao , Yin Dawei , Yang Huisan
Published: November 2019

Many hazards encountered during coal mining can be caused by the instability and failure of the composite structure of the coal seam and the surrounding rock strata. The defects present in the coal affect the structural stability of the composite structure. In this study, uniaxial compression tests were conducted on sandstone‐coal composite samples with pre‐existing cracks in the coal, combined with tests performed with an acoustic emission (AE) device and a digital video camera. The strength, macrofailure initiation (MFI), and failure characteristics of composite samples, as influenced by the coal’s pre‐existing cracks, were analysed. The coal’s pre‐existing cracks were shown to reduce the strength, promote the occurrence of MFI, and affect the failure characteristics of the samples. Vertical penetration cracks had much more pronounced effects on strength and MFI occurrence, especially vertical penetration cracks that penetrated through the centre of the coal. Horizontal penetration cracks had a much reduced effect on strength and MFI occurrence. The MFI caused a step shape in the stress‐strain curve accompanied with a peak energy index signal and occurred around the original coal cracks. The MFI models predominantly exhibited crack initiation from the pre‐existing coal cracks and surface spalling caused by crack propagation. The intact composite sample failure presented as an instantaneous failure, whereas the composite samples containing the pre‐existing cracks showed a progressive failure. The failures of composite samples occurred predominantly within the coal and displayed an X‐typed shear failure accompanied by a small splitting failure. Both the coal and sandstone were destroyed in the composite sample with vertical penetration cracks through the centre of the coal. Failure of the coal occurred through a splitting failure accompanied by a small X‐typed shear failure, while the sandstone showed a splitting failure induced by crack propagation in the coal.
Prevention of Potential Adverse Metabolic Effects of a Supplementation with Omega-3 Fatty Acids Using a Genetic Score Approach
Authors: Franck Maximilien , de Toro-Martín Juan , Guénard Frédéric , Rudkowska Iwona , Lemieux Simone , Lamarche Benoît , Couture Patrick , Vohl Marie-Claude
Published: November 2019

Introduction: The consumption of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) has been reported to have beneficial health effects, notably, by reducing plasma triglyceride levels. Nonetheless, a concomitant decrease in insulin sensitivity has also been observed, but is highly variable among subjects. Herein, we aimed to determine the importance of the genetic background in the interindividual variability of the insulin sensitivity response following an n-3 PUFA supplementation. Methods: A total of 210 participants completed a 6-week n-3 PUFA supplementation with 5 g/day of fish oil (providing 1.9–2.2 g of eicosapentaenoic acid + 1.1 g of docosahexaenoic acid). Insulin resistance was estimated by the homeostatic model assessment (HOMA-IR), and participants were further classified as high-risk or low-risk depending on their HOMA-IR change following the n-3 PUFA supplementation, as compared to pre-supplementation values. Genome-wide genotyping data were obtained for 138 participants using HumanOmni-5-Quad BeadChips containing 4,301,331 single nucleotide polymorphisms. A genome-wide association analysis (GWAS) was carried out between high-risk and low-risk participants. The population study was split into training (60%) and testing (40%) datasets to assess the predictive accuracy of a genetic risk score (GRS) constructed by summing the number of risk alleles. Results: Following the n-3 PUFA supplementation, 32 participants had increased HOMA-IR as compared to initial values and were classified as high risk (23.2%), whereas remaining subjects were classified as low risk (n = 106, 76.8%). A total of 8 loci had frequency differences between high-risk and low-risk participants at a suggestive GWAS association threshold (p value <1 × 10–5). After applying 10-fold cross validation, the GRS showed a significant association with the risk of increased HOMA-IR in the testing dataset (OR = 3.16 [95% CI, 1.85–7.14]), with a predictive accuracy of 0.85, and explained 40% of variation in HOMA-IR change. Conclusions: These results suggest that the genetic background has a relevant role in the interindividual variability observed in the insulin sensitivity response following an n-3 PUFA supplementation. Subjects being at risk of insulin sensitivity lowering following an n-3 PUFA supplementation may be identified using genetic-based precision nutrition approaches.
Usefulness of Percutaneous Transesophageal Gastro-Tubing in Patients Receiving Chemoradiotherapy for Advanced Esophageal Cancer: A Case Report
Authors: Naganuma Atsushi , Kishi Ayaka , Ogawa Yusuke , Kudo Tomohiro , Kitamoto Yoshizumi , Ogawa Tetsushi , Oishi Hideto
Published: November 2019

Percutaneous endoscopic gastrostomy (PEG) is often performed for nutritional management in advanced esophageal cancer. We here report a patient who initially received enteral nutrition via a nasogastric tube and in whom the subsequent use of percutaneous transesophageal gastro-tubing (PTEG) circumvented the need for a gastrostomy. It is believed that PEG is less painful than a nasogastric tube. However, we selected PTEG because a PEG would have been within the planned irradiation field and there was concern about radiation dermatitis. We were able to administer chemoradiotherapy with sufficient nutrition via an enteral feeding tube via esophagostomy. PTEG is a very useful tool in patients at risk of radiation dermatitis of the abdomen.
Synthetic Glucocorticoid-Induced Leucine Zipper Peptide Inhibits Lipopolysaccharide-Induced Ocular Inflammation in Rats
Authors: Guo Yue , Gu Ruiping , Yu Jian , Lei Boya , Gan Dekang , Xu Gezhi
Published: November 2019

Purpose: To demonstrate the anti-inflammatory action of a synthetic glucocorticoid-induced leucine zipper (GILZ98–134) peptide (GILZ-p) in a model of endotoxin-induced uveitis (EIU) in rats. Methods: The EIU model was induced in Sprague Dawley rats with an intravitreal injection of lipopolysaccharide (LPS). Synthetic GILZ-p was injected intravitreally 6 h after the LPS injection. To evaluate the anti-inflammatory effects of GILZ-p, the inflammatory response in the anterior chamber and iris of the rat eyes was evaluated with a slitlamp microscope on days 0, 1, 2, 3, and 4 after GILZ-p injection. The retinal expression of inflammatory cytokines was measured on days 0, 1, 2, 3, and 4 after GILZ-p injection. Müller cell gliosis was also detected at planned time points after GILZ-p injection. Results: Anterior segment inflammation peaked at 24 h after LPS injection in the EIU model. Compared with the controls, intravitreal GILZ-p significantly suppressed LPS-induced anterior segment inflammation in the EIU rats. The levels of retinal inflammatory factors IL-1β, TNF-α, MCP-1, and ICAM-1 were simultaneously reduced by the intravitreal GILZ-p injection. The expression of vimentin in the EIU retina was significantly reduced by GILZ-p, and the downregulated aquaporin 4 in the EIU retina was significantly restored by GILZ-p. Conclusion: The synthetic GILZ-p inhibited the inflammatory reaction in the EIU model and may have utility in the treatment of inflammatory ocular disease.
Impact of Intravitreal Ranibizumab Therapy on Vision Outcomes in Diabetic Macular Edema Patients: A Meta-Analysis
Authors: Falcão Manuel
Published: November 2019

Purpose: Evaluation of the impact of the injection frequency of ranibizumab on best-corrected visual acuity (BCVA) outcomes in patients with diabetic macular edema (DME). Methods: A meta-analysis of randomized controlled trials (RCTs) and real-world studies was performed to quantify the effect of ranibizumab treatment on BCVA and central foveal thickness (CFT) in DME as well as the relationship between the number of injections and the change in BCVA/CFT. Results: All combined sources (29 RCTs and 11 real-life studies) showed a significant increase in BCVA from baseline following anti-vascular endothelial growth factor (VEGF) treatment (8.2, 9.4, and 10.3 ETDRS letters gained after 12, 24, and 36 months of ranibizumab treatment, respectively). The largest changes in BCVA were observed in RCTs and the smallest in real-life studies at 12 months. A significant relationship was found between the number of injections and change in BCVA at 12 months. Conclusions: Inferior vision outcomes were observed in clinical practice compared with RCTs and might be partly attributable to administration of fewer anti-VEGF injections. Physicians should be aware that early and appropriate anti-VEGF treatment regimens are necessary to obtain the results reported in RCTs and help prevent irreversible vision loss in DME patients.
Infallible or Final?: Revisiting the Legitimacy of the International Court of Justice as the “Invisible” International Supreme Court
Authors: Nucup Neil B.
Published: November 2019

With the anarchic multiplication of international courts and tribunals, and the concomitant possibility for jurisdictional and decisional conflicts among them to occur, treating the International Court of Justice as the “invisible” international supreme court seems an attractive solution. After all, it is the principal judicial organ of the United Nations and the only court with universal general jurisdiction. Revisiting this proposal, the article argues that the World Court suffers not only from political (extrinsic) constraints, but also from institutional (intrinsic) limitations, thereby endangering its sociological and normative legitimacy. Nonetheless, this does not mean rectifying them for the purpose of enabling it to discharge its envisioned role as the international supreme court. Rather the problem is not so much improving the World Court, but understanding the merits of maintaining the status quo, that is, a decentralised judiciary.
International Court of Justice: The Role of Consent in the Context of Judicial Propriety Deconstructed in Light of Chagos Archipelago
Authors: Polonskaya Ksenia
Published: November 2019

This article examines the notion of consent as an element of judicial propriety as defined by the International Court of Justice (ICJ) in the context of its advisory function. The article situates the issue of judicial propriety within a broader conversation on the Court’s normative outlooks in international law, and examines the most recent advisory opinion on the Chagos Archipelago to understand how the Court itself views its role in international law. The article concludes that the Court’s advisory opinions do not provide much clarity as to the circumstances in which a lack of consent will become a compelling enough reason to justify a refusal to give an advisory opinion. The Court appears to ritually recite consent as a relevant element in its assessment of judicial propriety, however, it continues to limit such relevance.
(Not) Proving the Public Good: Scientific Evidence and the Margin of Appreciation
Authors: Burke Ciarán , Molitorisová Alexandra
Published: November 2019

The article offers a critical look at the complex relationship between the European Court of Human Rights (ECtHR) and policy-supportive (scientific) evidence. In particular, due to now commonplace, evidence-based policy-making of national governments, the Court is effectively supplemented with various statistics and studies and tasked with reviewing policy measures aiming to improve the public good. This article investigates the ECtHR’s use and interpretation of policy-supportive evidence in the proportionality analysis, and how this affects the margin of appreciation. The recent case of Dubská and Krejzová concerning the ban on home births, which the article explores in detail, is illustrative in this regard. Although the Court appears to review scientific evidence substantively, an increased proliferation of statistics and studies may bring about controversy in relation to legal cases, without having a conclusive impact upon the outcome of a dispute.
Working in the ‘White Man’s Grave’: Wages and Migration from Europe to the Gold Coast in the Eighteenth Century
Authors: Rönnbäck Klas , Öberg Stefan , Galli Stefania
Published: November 2019

This article examines the economic incentives for Europeans to migrate to the so-called ‘white man’s grave’ of West Africa. Ignorance and coercion have been proposed as explanations for migration to high mortality areas. We use data on the Royal African Company and their European employees on the Gold Coast during the period 1707–1740. We found that the employees received a premium above the wage they would have received in England. Economic reasons might therefore have swayed the decision to migrate. Nevertheless, the wage premium was low in relation to the very high risk of dying. The migrating men either placed a low value on their own lives, or did not understand the risks they were facing.
Description of a female and variation of Microgomphus alani Kosterin, 2016 (Odonata: Gomphidae) in Cambodia, with a note on sexual dimorphism in Microgomphus spp.
Authors: KOSTERIN OLEG E.
Published: November 2019

Microgomphus alani Kosterin, 2016 was described from two teneral males from the Cardamom Mts. in SW Cambodia; it turned out that the description was based on the holotype with the anal appendages not fully expanded. Further specimens of M. alani (all mature) are reported: a male and two females from the Phnom Kulen Mts, NW Cambodia and five males and one female from Mondulkiri Province, E Cambodia. The appendage shape in mature males is illustrated and discussed and the female is described for the first time. The specimens from E Cambodia are ca 15-20% larger than those from SW and NW Cambodia and exhibit some differences in the shapes of the male epiproct and anterior hamulus and face maculation, however evaluated as insufficient to erect a new taxon. A hitherto neglected manifestation of sexual dimorphism in probably most Microgomphus spp. and at least some Heliogomphus spp. is pointed out. It concerns the mid- and metafemur, in males armed with numerous, dense and small spinulets but with two rows of long, sparse spines in females. An earlier report of Microgomphus jurzitzai Karube, 2000 for Cambodia was based on a misidentified M. alani specimen and is cancelled. A female specimen earlier identified and described from Thailand as Heliogomphus selysi Fraser, 1925 most probably was M. alani as well.
An Optical Model for Quantitative Raman Microspectroscopy
Authors: Razzell Hollis Joseph , Rheingold David , Bhartia Rohit , Beegle Luther W.
Published: November 2019

Raman spectroscopy is an invaluable technique for identifying compounds by the unique pattern of their molecular vibrations and is capable of quantifying the individual concentrations of those compounds provided that certain parameters about the sample and instrument are known. We demonstrate the development of an optical model to describe the intensity distribution of incident laser photons as they pass through the sample volume, determine the limitations of that volume that may be detected by the spectrometer optics, and account for light absorption by molecules within the sample in order to predict the total Raman intensity that would be obtained from a given, uniform sample such as an aqueous solution. We show that the interplay between the shape and divergence of the laser beam, the position of the focal plane, and the dimensions of the spectrometer slit are essential to explaining experimentally observed trends in deep ultraviolet Raman intensities obtained from both planar and volumetric samples, including highly oriented pyrolytic graphite and binary mixtures of organic nucleotides. This model offers the capability to predict detection limits for organic compounds in different matrices based on the parameters of the spectrometer, and to define the upper/lower limits within which concentration can be reliably determined from Raman intensity for such samples. We discuss the potential to quantify more complex samples, including as solid phase mixtures of organics and minerals, that are investigated by the unique instrument parameters of the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) investigation on the upcoming Mars 2020 rover mission.
Long-term offshore wind power prediction using spatiotemporal kriging: A case study in China’s Guangdong Province
Authors: Hu Hongda , Hu Zhiyong , Zhong Kaiwen , Xu Jianhui , Wu Pinghao , Zhao Yi , Zhang Feifei
Published: November 2019

The predicted wind power in coastal waters is an important factor when planning and developing offshore wind farms. The stochastic wind field challenges the accuracy of these predictions. Using single-point wind measurements, most previous studies have focused on the prediction of short-term wind power, ranging from minutes to several days. Longer-term wind power predictions would better support decision-making related to offshore wind power balance management and reserve capacities. In addition, larger-scale wind power predictions, based on gridded wind field data, would provide a more comprehensive understanding of the spatiotemporal variations of wind energy resources. In this study, a spatiotemporal ordinary kriging model was developed to predict the offshore wind power density on a monthly basis using the cross-calibrated multiplatform gridded wind field data. The spatiotemporal variations of wind power density were directly quantified through the development of spatiotemporal variograms that integrated spatial and temporal distances. The proposed model achieved a notable performance with an overall R2 of 0.94 and a relative prediction error of 16.35% in the validation experiment of predicting the monthly wind power density from 2013 in the coastal waters of China’s Guangdong Province. Using this model, the spatial distributions of wind power density along Guangdong’s coastal waters at monthly, seasonal, and annual time-scales from 2013 were accurately predicted. The experiment results demonstrated the remarkable potential of the spatiotemporal ordinary kriging model to provide reliable long-term prediction for offshore wind energy resources.
Synchronous state of unbalanced rotors in a three-dimensional space and far-resonance system
Authors: Fang Pan , Peng Huan , Changcheng Du , Zou Min , Hou Duyu , Du Mingjun , Chai Guodong
Published: November 2019

The unreasonable dynamic characteristics results in decrease of screening efficiency of the vibrating screen. However, the synchronous behavior of motors is key factor to determine dynamic characteristics of the screens. In this paper, two unbalanced rotors actuated with motors in a three-dimensional space are proposed. To understand the synchronous mechanism, the dynamic equation of the system is firstly confirmed based on Lagrangian formulation; meanwhile, synchronization condition of the system is calculated with average and small parameter method; then, synchronization stability of the system is explored by Lyapunov method; finally, some numerical simulations are given to validate the theoretical computations. It is found that, to implement the stable synchronous rotation between the rotors, the values of the parameter in this system must be satisfied by synchronous condition and synchronous stability; the synchronous state is determined by the rotation direction, the damping ratio, the frequency ratio, and the motor position; the system is a planar motion when the identical mass rotors oppositely actuated, but the system is a spatial motion in the other cases.
Assessment of Genomic Instability in Medical Workers Exposed to Chronic Low-Dose X-Rays in Northern China
Authors: Fang Lianying , Li Jieqing , Li Weiguo , Mao Xuesong , Ma Ya , Hou Dianjun , Zhu Wei , Jia Ximing , Qiao Jianwei
Published: November 2019

The increasing use of ionizing radiation (IR) in medical diagnosis and treatment has caused considerable concern regarding the effects of occupational exposure on human health. Despite this concern, little information is available regarding possible effects and the mechanism behind chronic low-dose irradiation. The present study assessed potential genomic damage in workers occupationally exposed to low-dose X-rays. A variety of analyses were conducted, including assessing the level of DNA damage and chromosomal aberrations (CA) as well as cytokinesis-block micronucleus (CBMN) assay, gene expression profiling, and antioxidant level determination. Here, we report that the level of DNA damage, CA, and CBMN were all significantly increased. Moreover, the gene expression and antioxidant activities were changed in the peripheral blood of men exposed to low-dose X-rays. Collectively, our findings indicated a strong correlation between genomic instability and duration of low-dose IR exposure. Our data also revealed the DNA damage repair and antioxidative mechanisms which could result in the observed genomic instability in health-care workers exposed to chronic low-dose IR.
An Analysis of Emerging Patterns of Consumption in the Age of Globalization and Digitalization
Authors: Yeganeh Hamid
Published: November 2019

This paper analyzes emerging patterns of consumption in the modern world marked by the forces of globalization and digitalization. The study adopts a multidisciplinary approach and relies on the existing literature to identify seven key trends including the rise of the global middle class, urbanized consumption, glocalization, shortening products lifecycles, the rising cost of consumers’ attention, digital consumers, and the collaborative consumption. The findings and implications are discussed and some avenues for future research are suggested.
From Budd-Chiari syndrome to acquired von Willebrand syndrome: thrombosis and bleeding complications in the myeloproliferative neoplasms
Authors: Stein Brady L. , Martin Karlyn
Published: November 2019

Stein and Martin provide a review of the thrombotic and bleeding complications of myeloproliferative neoplasms and provide a roadmap for appropriate therapy.
Empagliflozin, a sodium glucose co-transporter-2 inhibitor, alleviates atrial remodeling and improves mitochondrial function in high-fat diet/streptozotocin-induced diabetic rats
Authors: Shao Qingmiao , Meng Lei , Lee Sharen , Tse Gary , Gong Mengqi , Zhang Zhiwei , Zhao Jichao , Zhao Yungang , Li Guangping , Liu Tong
Published: November 2019

Background

Diabetes mellitus is an important risk factor for atrial fibrillation (AF) development. Sodium–glucose co-transporter-2 (SGLT-2) inhibitors are used for the treatment of type 2 diabetes mellitus (T2DM). Their cardioprotective effects have been reported but whether they prevent AF in T2DM patients are less well-explored. We tested the hypothesis that the SGLT-2 inhibitor, empagliflozin, can prevent atrial remodeling in a diabetic rat model.

Methods

High-fat diet and low-dose streptozotocin (STZ) treatment were used to induce T2DM. A total of 96 rats were randomized into the following four groups: (i) control (ii) T2DM, (iii) low-dose empagliflozin (10 mg/kg/day)/T2DM; and (iv) high-dose empagliflozin (30 mg/kg/day)/T2DM by the intragastric route for 8 weeks.

Results

Compared with the control group, left atrial diameter, interstitial fibrosis and the incidence of AF inducibility were significantly increased in the DM group. Moreover, atrial mitochondrial respiratory function, mitochondrial membrane potential, and mitochondrial biogenesis were impaired. Empagliflozin treatment significantly prevented the development of these abnormalities in DM rats, likely via the peroxisome proliferator-activated receptor-c coactivator 1α (PGC-1α)/nuclear respiratory factor-1 (NRF-1)/mitochondrial transcription factor A (Tfam) signaling pathway.

Conclusions

Empagliflozin can ameliorate atrial structural and electrical remodeling as well as improve mitochondrial function and mitochondrial biogenesis in T2DM, hence may be potentially used in the prevention of T2DM-related atrial fibrillation.
The effects of daily meteorological perturbation on pregnancy outcome: follow-up of a cohort of young women undergoing IVF treatment
Authors: Zhao Mingpeng , Zhang Haoyang , Waters Tarah H. B. , Chung Jacqueline Pui Wah , Li Tin Chiu , Chan David Yiu Leung
Published: November 2019

Background

Human reproduction follows a seasonal pattern with respect to spontaneous conception, a phenomenon wherein the effect of meteorological fluctuations might not be unique. However, the effect of seasonal variations on patients who underwent in vitro fertilization (IVF) treatment is unclear. We aimed to evaluate the effects of meteorological variation on the pregnancy rate in a cohort undergoing IVF treatment by performing multivariable analyses.

Methods

We conducted a cohort study in a sub-tropical region with prominent seasonal variations (2005–2016). Women aged < 35 years who were treated with a long ovarian stimulation protocol and underwent fresh embryo transfer (ER) were included. Data on gonadotropin administration (CYCL), oocyte retrieval (OR), ER, and pregnancy outcomes were prospectively recorded. For each patient, the daily average of meteorological data (temperature, humidity, sunlight duration, solar radiation) was recorded from the date of CYCL to ER. Multiple logistic regression analysis adjusted for age, fertilization method, year of the cycle, gonadotropin dose, and transferred embryo grade was performed to determine the relationship between the meteorological parameters and clinical pregnancy. Patients with one successful cycle and one failed cycle were subtracted for a case-control subgroup analysis through mixed effect logistics regressions. Time-series analysis of data in the epidemic level was conducted using the distributed lag linear and non-linear models (DLNMs).

Results

There were 1029 fresh cycles in 860 women (mean age 31.9 ± 2.0 years). Higher mean temperature from CYCL to OR (adjusted odds ratio [aOR] 1.04; 95% confidence interval [CI] 1.01–1.07, P = 0.01) increased the odds of pregnancy, while OR to ER did not show any statistical significance. Compared to that in winter, the odds of becoming pregnant were higher during higher temperature seasons, summer and autumn (aOR 1.47, 95%CI 0.97–2.23, P = 0.07 (marginally significant) and aOR 1.73, 95%CI 1.12–2.68, P = 0.02, respectively). Humidity, sunlight duration, and solar radiation had no effect on the outcome. The subgroup analysis confirmed this finding. The time-series analysis revealed a positive association between temperature and relative risk for pregnancy.

Conclusions

In IVF treatment, the ambient temperature variation alters the pregnancy rates; this aspect must be considered when obtaining patient consent for assisted conception.
Workplace bullying and its impact on the quality of healthcare and patient safety
Authors: Al Omar Munirah , Salam Mahmoud , Al-Surimi Khaled
Published: November 2019

Background

Workplace bullying (WPB) is a physical or emotional harm that may negatively affect healthcare services. The aim of this study was to determine to what extent healthcare practitioners in Saudi Arabia worry about WPB and whether it affects the quality of care and patient safety from their perception.

Methods

A cross-sectional study was conducted in 2018. An online survey was distributed among all practitioners at a multi-regional healthcare facility. A previously validated tool was sourced from an integrative literature review by Houck and Colbert. Responses to 15 themes were rated on a 5-point Likert scale, converted to percentage mean scores (PMS) and compared across participants’ characteristics using bivariate and regression analyses.

Results

A total of 1074/1350 (79.5%) completed the questionnaire. The overall median [interquartile range] score of worrying about WPB was 81.7 [35.0]. Participants were mainly worried about the effect of WPB on their stress, work performance, and communication between staff members. A significant negative relationship developed between the quality of care and worrying about WPB,P< 0.001. More educated practitioners were 1.7 times more likely to be worried about WPB compared with their counter group, adj.P= 0.034. Junior practitioners were 1.6 times more likely to be worried about WPB, adj.P= 0.017. The group who has not been trained in handling WPB (1.7 times), and those who had been exposed to WPB (2.2 times) were both more likely to be worried about WPB compared with their counter groups, adj.P= 0.026 and adj.P< 0.001 respectively.

Conclusions

Most healthcare practitioners worry about WPB, especially its negative impact on the quality of care and patient safety. A greater proportion of practitioners with higher levels of education and their less experienced counterparts were more worried about WPB. Previous exposure to a WPB incident amplifies the practitioners’ worry, but being trained on how to counteract bullying incidents makes them less likely to be worried.
The glucagon-like peptide-1 receptor agonist reduces inflammation and blood-brain barrier breakdown in an astrocyte-dependent manner in experimental stroke
Authors: Shan Yilong , Tan Sha , Lin Yinyao , Liao Siyuan , Zhang Bingjun , Chen Xiaodong , Wang Jihui , Deng Zhezhi , Zeng Qin , Zhang Lei , Wang Yuge , Hu Xueqiang , Qiu Wei , Peng Lisheng , Lu Zhengqi
Published: November 2019

Background

Preserving the integrity of the blood-brain barrier (BBB) is beneficial to avoid further brain damage after acute ischemic stroke (AIS). Astrocytes, an important component of the BBB, promote BBB breakdown in subjects with AIS by secreting inflammatory factors. The glucagon-like peptide-1 receptor (GLP-1R) agonist exendin-4 (Ex-4) protects the BBB and reduces brain inflammation from cerebral ischemia, and GLP-1R is expressed on astrocytes. However, the effect of Ex-4 on astrocytes in subjects with AIS remains unclear.

Methods

In the present study, we investigated the effect of Ex-4 on astrocytes cultured under oxygen-glucose deprivation (OGD) plus reoxygenation conditions and determined whether the effect influences bEnd.3 cells. We used various methods, including permeability assays, western blotting, immunofluorescence staining, and gelatin zymography, in vitro and in vivo.

Results

Ex-4 reduced OGD-induced astrocyte-derived vascular endothelial growth factor (VEGF-A), matrix metalloproteinase-9 (MMP-9), chemokine monocyte chemoattractant protein-1 (MCP-1), and chemokine C-X-C motif ligand 1 (CXCL-1). The reduction in astrocyte-derived VEGF-A and MMP-9 was related to the increased expression of tight junction proteins (TJPs) in bEnd.3 cells. Ex-4 improved neurologic deficit scores, reduced the infarct area, and ameliorated BBB breakdown as well as decreased astrocyte-derived VEGF-A, MMP-9, CXCL-1, and MCP-1 levels in ischemic brain tissues from rats subjected to middle cerebral artery occlusion. Ex-4 reduced the activation of the JAK2/STAT3 signaling pathway in astrocytes following OGD.

Conclusion

Based on these findings, ischemia-induced inflammation and BBB breakdown can be improved by Ex-4 through an astrocyte-dependent manner.