bluuebunny/crossref_metadata_2025 huggingface dataset:
Flutter Stability of a Long-Span Suspension Bridge During Erection in Mountainous Areas
Authors: Chen Xingyu , Hu Ruijie , Tang Haojun , Li Yongle , Yu Enbo , Wang Lei
Published: June 2020

In mountainous areas, more challenges are expected for the construction of long-span bridges. The flutter instability during erection is an outstanding issue due to flexible structural characteristics and strong winds with large angles of attack. Taking the suspension bridge as an example, the flutter stability of the bridge with different suspending sequences was investigated. First, the dynamic characteristics of the bridge during erection were computed by the finite element software ANSYS, along with the effects on flutter stability discussed. Then, different aerodynamic shapes of the bridge girder during erection were considered. The aerodynamic coefficients and the critical flutter state were determined by wind tunnel tests. Based on the above analysis, some structural measures are proposed for improving the flutter stability of the bridge during erection. The results show that the flutter stability of the bridge during erection is related to the suspending sequence and the aerodynamic shape of the girder. Owing to the structural dynamic characteristics, the bridge has better flutter stability when the girder segments are suspended symmetrically from the two towers to the mid-span. Considering the construction requirement that the bridge deck should be laid without intervals, this structural superiority is seriously weakened by the unfavorable aerodynamic shape of the girder. In order to improve the flutter stability of the bridge during erection, an effective way is to adopt some temporary structural strengthening measures.
Vortex-Induced Vibration of a Tall Bridge Tower with Four Columns and the Wake Effects on the Nearby Suspenders
Authors: Fang Chen , Wang Zewen , Tang Haojun , Li Yongle , Deng Zhouquan
Published: June 2020

With the increasing span of suspension bridges, the towers have higher heights and have become more flexible, and so do the nearby suspenders. Not only are the towers easy to be affected by winds, but also the nearby suspenders by the wake flow of the towers. To enhance the structural stiffness, a bridge tower may be designed with more columns, but this design may lead to strong aerodynamic interference among the columns, complicating the wind-induced behaviors of the tower and nearby suspenders. In this paper, wind tunnel tests and numerical simulations were carried out to investigate the vortex-induced vibration of a tall bridge tower with four columns, and the wake effects on nearby suspenders. The results show that the displacement response at the tower top increases with the increasing wind speed. No obvious lock-in region is observed, as different cross-sections of the tower show different vortex shedding characteristics. The vortex shedding characteristics are determined mainly by the aerodynamic forces acting on the leeward columns. In the wake of the tower, the aerodynamic forces of the suspenders have the same dominant frequencies as the shedding frequencies of the vortices from the tower. The frequencies may approach the natural frequencies of the suspenders, causing possible wake-induced vibration that should be avoided for a good design.
A Developed Damage Constitutive Model for Circular Steel Tubes of Reticulated Shells
Authors: He Sheng , Wang Haosen , Bordas Stéphane P. A. , Yu Peng
Published: June 2020

The aim of this paper is that the precise description of damage behavior is crucial to well catch the mechanical behavior of structures in the dynamic numerical simulation, and address the issue on the coupled plastic-damage constitutive model for circular steel tubes of reticulated shells under severe earthquake. Continuum Damage Mechanics (CDM) constitutive model established by Lemaitre is reviewed at the beginning. Then, an improved damage model for circular steel tubes of reticulated shells is developed based on Lemaitre’s model by replacing the original damage evolution law with a new one suitable for circular steel tubes. In addition, we introduce the stress update process. In this procedure, the well-known operator split strategy, which leads to the standard elastic predictor/return mapping algorithm, is adopted to solve the evolution problem of the improved model. Exploiting user-defined material subroutine, the implementation of the model is achieved within software ANSYS using BEAM189 element. Finally, the dynamic response of reticulated shells under severe earthquake are numerically simulated with the proposed model and with the conventional Prandtl-Reuss model, respectively. The comparison results show that the consideration of material damage accumulation, on the one hand, may change the failure mode of reticulated shells from dynamic instability to strength failure; on the other, may reduce the dynamic ultimate load obviously. This consideration should be taken into account when conducting nonlinear dynamic analysis of reticulated shells.
Theoretical elucidation of the energy conversion rate in organic photovoltaic cells of the fullerene nanostructure derivatives. A density functional theory study
Authors: Deddouche Nadjet , Chemouri Hafida
Published: June 2020

A comparative theoretical study of the kinetics of the Diels–Alder (DA) reaction between empty fullerene (C[Formula: see text]) and lithium ion encapsulated fullerene ([Formula: see text]) with 1,3 cyclohexadiene (C[Formula: see text]H[Formula: see text]) was carried out. This reaction takes place in a photovoltaic cell. The effect of the encapsulated [Formula: see text] ion on the conversion rate of solar energy into electricity has been highlighted through calculations based on the density functional theory (DFT). In addition, a static study using the global conceptual DFT indices, as part of the demonstration of the significant electrophilic power of the fullerene nanostructure, was carried out to show the effect of encapsulating the [Formula: see text] ion in this nanoparticle on the electrophilic power of Li[Formula: see text]@C[Formula: see text] and therefore on the acceleration of the reaction. The relationship between the HOMOdonor–LUMOacceptor energy difference and the DA reaction acceleration, and therefore the acceleration of light conversion (a rapid conversion implies a small gap), has been thoroughly examined. Moreover, a mechanistic study of the kinetics of the DA reaction of the fullerene involved in an organic photovoltaic cell has been carried out. In this section, a concerted synchronous mechanism with no effect of [Formula: see text] encapsulation on the synchronicity of the reaction was observed. Finally, it was revealed that Li[Formula: see text]@C[Formula: see text] reacted approximately 2466 times faster than C[Formula: see text]. Moreover, the experimental results were found in good agreement with the computer calculations.
A class of maximally singular sets for rational approximation
Authors: Poëls Anthony
Published: June 2020

We say that a subset of [Formula: see text] is maximally singular if its contains points with [Formula: see text]-linearly independent homogenous coordinates whose uniform exponent of simultaneous rational approximation is equal to [Formula: see text], the maximal possible value. In this paper, we give a criterion which provides many such sets including Grassmannians. We also recover a result of the author and Roy about a class of quadratic hypersurfaces.
The high energy density and efficiency of PVDF-based composites with double-shell Nd-BaTiO3 particles as fillers
Authors: Yang Zhong , Wang Jing , He Long , Deng Chaoyong , Zhu Kongjun
Published: June 2020

Flexible dielectric capacitors are becoming shining stars in modern electronic devices. Ceramic particles with large dielectric constants and benign compatibility are attractive candidates to enhance the energy storage density of pristine polymer capacitors while guaranteeing their flexibility. In this work, double-shell structure of Al2O3 (AO) and dopamine (PDA) were successively coated on the Nd-doped BaTiO3 (NBT) particles and then introduced into the Poly(vinylidene fluoride) (PVDF) matrix. Obvious enhancement in dielectric constants was observed while the dielectric loss remained nearly constant. For the composite films with 1–4[Formula: see text]vol.% NBT@AO@PDA NPs, the maximum energy density of 9.1[Formula: see text]J/cm3 and energy efficiency of 65% was achieved at 430[Formula: see text]MV/m in the sample with 1[Formula: see text]vol.% filling ratio, which are 1.4 and 1.3 times larger than those of pristine PVDF at 450[Formula: see text]MV/m. The finite element simulation reveals the effective relief of the electric field concentration in the composite film induced by the AO and PDA layers. The greater improvement in the energy storage performance could be anticipated if the dispersity of NBT@AO@PDA NPs was further improved.
Emergence of Business Ecosystems by Transformation of Platforms Through the Process of Organizational Learning
Authors: Rupčić Nataša , Majić Tomislava , Stjepandić Josip
Published: June 2020

Innovation of products and services is a key success factor for the manufacturing industry. Development of upgraded and innovative products and services usually takes place in partnerships. In this regard, in the manufacturing industry, original equipment manufacturers (OEMs) distribute the development of new and innovative products to many different locations in various countries across the world. Suppliers, especially first-tier suppliers (FTSs), are then involved in the development of new products and services based on strategic firm-specific competences. The OEM–supplier relationship is characterized by a sequential interaction whereby OEMs specify product and production requirements to the suppliers and the suppliers then produce and deliver products or services to OEMs. Tight collaboration between FTSs and OEMs is essential to reduce costs and risks, anticipate potential downstream errors and enable fruitful implementation of FTSs’ knowledge and competencies. The paper presents recent developments in the OEM–FTS supply chain management with particular emphasis on the design of shared platforms which emerge as ecosystems on the basis of the joint organizational learning and stakeholder management. Development of such ecosystems could be viewed as a transdisciplinary process, combining expertise from various fields ranging from engineering, especially IT engineering, to management, especially supply chain, strategic and knowledge management.
Chapter 3 Pre-Late Cretaceous basement terranes of the Gondwana active margin of New Caledonia
Authors: Maurizot P. , Cluzel D. , Meffre S. , Campbell H. J. , Collot J. , Sevin B.
Published: June 2020

The basement under the Late Cretaceous unconformity in New Caledonia consists of three amalgamated terranes. They are all oceanic, arc-related and developed offshore from the eastern Gondwana active margin during periods of marginal basin development. Téremba Terrane is composed of deep sea Permian to Mesozoic arc-derived volcanic rocks and greywackes. The Koh–Central Terrane includes at its base an ophiolite with island arc tholeiites and boninites (Koh Ophiolite) of Late Carboniferous to Early Permian age overlain by a thick sequence of greywacke (Central Range Volcaniclastic Rocks) of Permian to Late Jurassic age. The Téremba Terrane and the Koh–Central Terrane may be part of the same forearc basin, with the rocks from the Koh–Central Terrane deposited in a deeper environment. The Boghen Terrane is a metamorphic complex composed of schists, broken formations and mafic–ultramafic mélange, derived from mixed terrigenous and volcanic sources. The overall fine grain size and laminar bedding suggest deep sea and more distal deposition than the other terranes. The maximum depositional ages from detrital zircons suggest deposition during the Early Jurassic to Early Cretaceous. The terrane is interpreted as a metamorphosed subduction complex that includes blueschist and greenschist facies metamorphic rocks exhumed through the Koh–Central Terrane. At a regional scale, the nature of these three pre-Late Cretaceous terranes confirms the existing palaeogeographical reconstructions, which locate New Caledonia outboard the ocean–continent subduction that surrounded Gondwana during the Paleozoic and Early Mesozoic. A detailed analysis of these terranes and their relationship with East Australian terranes of the same age shows that a marginal basin system probably existed between mainland Gondwana and proto-New Caledonia and closed before the Late Cretaceous. A tentative detailed reconstruction of this margin during the Carboniferous–Early Cretaceous period is proposed.
Chapter 9 Mineral resources and prospectivity of non-ultramafic rocks of New Caledonia
Authors: Maurizot P. , Sevin B. , Lesimple S. , Collot J. , Jeanpert J. , Bailly L. , Robineau B. , Patriat M. , Etienne S. , Monnin C.
Published: June 2020

The mineral resources of the non-ultramafic rocks of New Caledonia and its Exclusive Economic Zone can be classified according to their host rocks. The metallic mineral resources are essentially associated with volcanic and magmatic activity. Non-economic volcanogenic massive sulfide deposits with Cu and Au are located in the Late Carboniferous Koh Ophiolite and in the Late Cretaceous Poya Terrane. Base metals, Au and Ag of the sedimentary–exhalative type are present in the metamorphic Diahot-Panié Metamorphic Complex, associated with syn-rift volcanism. An Au–Sb metallogenic province is associated with the post-obduction Late Oligocene granitoids and co-genetic hydrothermal silica–carbonate (listwanite) zones in the Peridotite Nappe; Au is disseminated in the granites and Sb occurs as lodes in the silica–carbonate. Among the non-metallic mineral resources, barite, gypsum, magnesite, phosphate, clays, dimension stones, limestone for use as cement and as a neutralizer, and aggregates are all present. Gemstones such as jade and chrysoprase are only used locally. Late Cretaceous coal, which was briefly exploited in the past, is now considered to be a source rock for an offshore potential oil and gas system. Petroleum prospectivity is currently focused on the Fairway Basin. Several low-enthalpy thermo-mineral springs with a weak geothermal energy potential are known on Grande Terre.
Chapter 4 Late Cretaceous to Eocene cover of New Caledonia: from rifting to convergence
Authors: Maurizot P. , Bordenave A. , Cluzel D. , Collot J. , Etienne S.
Published: June 2020

In New Caledonia, the cover refers to the autochthonous Late Cretaceous to Paleogene sedimentary and volcanic formations unconformably overlying the basement rocks and underlying the allochthonous nappes. The first period of deposition, broadly from the Late Cretaceous to Paleocene (
c.
105–56 Ma) was controlled by extension and rifting. The second period, broadly the Eocene (
c.
56–34 Ma), was dominated by convergence and contraction. The Late Cretaceous part of the cover consists of synrift conglomerates and coal-bearing deposits with interlayered bimodal, subduction-related and intra-plate volcanic rocks. The post-rift deposits are deep water sedimentary rocks deposited under anoxic conditions with reduced terrigenous input. The Paleocene to Eocene formations, mainly carbonates, attest to profound palaeogeographical changes and a switch to a different geodynamic regime, linked to the onset of Eocene convergence. The Middle to Late Eocene formations are typically composed of turbidites and breccias. They were deposited in a typical flexural foreland basin context as an upwards-coarsening sequence topped by an olistostrome. They are associated with tectonic convergence and east-dipping subduction that led to the end-Eocene obduction of ophiolitic nappes. This two-fold evolution, extension then compression, can be integrated in the wider framework of the plate tectonic evolution of the SW Pacific.
Chapter 6 The Loyalty Islands and Ridge, New Caledonia
Authors: Maurizot P. , Collot J. , Cluzel D. , Patriat M.
Published: June 2020

The Loyalty Ridge lies to the east and NE of the Norfolk Ridge. The three main Loyalty Islands (Maré, Lifou and Ouvéa) emerge from the ridge at the same latitude as Grande Terre. The islands are uniformly composed of carbonate deposits, except for Maré, where Middle Miocene intra-plate basalts and associated volcaniclastic rocks form restricted outcrops. Miocene rhodolith limestones constitute the bulk of the carbonate cover of the three islands. On Maré, these platform accumulations are locally topped by a dolomitic hardground, which, in turn, is covered by Pliocene–Pleistocene coral-bearing formations. These coral reef constructions are preserved as elevated rims over all three islands and define an atoll stage in their development. The Pleistocene–Holocene palaeoshoreline indicators include fringing bioconstructions and marine notches and record both eustatic sea-level changes and tectonic deformation. The ridge has been in the forebulge region in front of the active Vanuatu subduction zone since the Pliocene and each of the three islands has been uplifted and tilted to varying degrees. Offshore, the Loyalty Ridge continues northwards to the d'Entrecasteaux Zone and southwards to the Three Kings Ridge. Although typically volcanic, the nature of the deep Loyalty Ridge remains unknown.
Chapter 7 Post-obduction evolution of New Caledonia
Authors: Sevin B. , Maurizot P. , Cluzel D. , Tournadour E. , Etienne S. , Folcher N. , Jeanpert J. , Collot J. , Iseppi M. , Meffre S. , Patriat M.
Published: June 2020

The post-obduction formations of Grande Terre, New Caledonia, comprise igneous intrusions, regolith cover, and marine and terrestrial sedimentary rocks. Two restricted Late Oligocene granitoid bodies are intruded into the Peridotite Nappe and its substrate in the south of the island. Thick regolith cover developed over the Peridotite Nappe from the Late Oligocene or earlier. The Népoui Group comprises Late Oligocene–Early Miocene mixed marine carbonate and siliciclastic deposits. It mainly reworks the Peridotite Nappe and its regolith cover. Its development pattern is mainly controlled by tectonic uplift and subsidence. The Gwa N'Doro Formation on the eastern coast and the Fluvio-lacustrine Formation in the south are remnants of the Miocene–Present river network. Offshore, thick Oligocene to Neogene sedimentary successions are imaged by seismic surveys on the margins of Grande Terre, although these successions have not been drilled and remain undated. Several dredges have recovered shallow Miocene sedimentary rocks, indicating substantial Neogene subsidence. Quaternary formations are represented inland by aeolianite, vertisols and calcrete and offshore by the large barrier reef–lagoon complex, the onset of which is dated at
c.
400 ka. This chapter discusses the different models proposed for the post-obduction evolution of Grand Terre.
WISE
Authors: Ammar Mahmoud , Crispo Bruno
Published: June 2020

The Internet of Things (IoT) is shaped by increasing number of low-cost Internet-connected embedded devices that are becoming ubiquitous in every aspect of modern life, including safety- and privacy-critical application scenarios. Such devices offer limited or no security features, creating a large new attack surface. One key component in securing these devices is software integrity checking, which is typically attained with
Remote Attestation
(RA). RA is a security service that helps in detecting malware-infected IoT devices through remotely verifying their internal state by a trusted party. In the vast majority of IoT application domains, IoT devices operate in swarms or groups to achieve common tasks. Existing swarm attestation techniques are still rigid and not smart enough to address heterogeneity and adapt the different requirements of various IoT devices connected to a swarm, thus triggering the need for more efficient swarm attestation schemes.

In this article, we present WISE, the first intelligent swarm attestation scheme that takes into account the various characteristics, differences, and requirements of connected devices in a swarm, aiming at minimizing the communication overhead while preserving an adequate level of security. WISE depends on a resource-efficient smart broadcast authentication scheme where devices are organized in fine-grained multi-clusters, and whenever needed, the most likely compromised devices are attested. The candidate devices are selected intelligently taking into account the attestation history and diverse characteristics and constraints of each device in the swarm. We show that WISE is suitable for resource-constrained embedded devices, highly efficient and scalable in static and dynamic heterogeneous IoT networks, and offers an adjustable level of security.
The Effects of Computer Science Stereotypes and Interest on Middle School Boys’ Career Intentions
Authors: Dou Remy , Bhutta Karina , Ross Monique , Kramer Laird , Thamotharan Vishodana
Published: June 2020

Like other STEM fields, computer science (CS) lacks representation of minorities, such as Black and Hispanic individuals, both in the number of bachelor’s degrees obtained and the number of individuals in the CS workforce. Out-of-school CS programs are often designed with the intent to inspire young people to pursue careers in CS. Much of this programming focuses on developing student interest in CS and CS careers. Nevertheless, it is not well understood how the stereotypes that children hold about computer scientists contribute to CS interest and career choice. In this study, we set out to examine the complex relationships between CS interest, held stereotypes, and CS career choice. We surveyed participants in an after-school CS program offered to middle school boys who identified with racial and ethnic minority groups (N= 110). We tested three linear regression models and confirmed that CS interest and socially divergent stereotypes—those that diverged from societal norms—of computer scientists play unique and contrary roles in young boys’ career decision-making process even when controlling for home and school factors. These models suggest educational CS programs should include curriculum to dispel participants’ socially divergent stereotypes about computer scientists rather than targeting CS interest alone, particularly if a goal is to inspire diverse young people to pursue careers in CS.
Review of Market Design
Authors: Nagaraj S.V.
Published: June 2020

Nowadays, supply has to be matched with demand for various types of goods and services. For designing real-world markets, the study of market design becomes essential, which is the focus of this book. The book comprises four parts and consists of twelve chapters. A brief introductory chapter provides an outline of the book. The first part focuses on microeconomic fundamentals. The second part is on multi-object auction design. The third part looks at approximation and matching markets. The fourth part has appendices on linear optimization, and algorithms and complexity At the end of the book, there are references to the literature and a helpful index. Many chapters include questions for comprehension and problems for practice. The book is intended to be a textbook for a single semester course on market design. The prerequisites for the book include familiarity with linear programming, integer linear programming, rudimentary calculus and probability theory. The intended audience comprises students with backgrounds in computer science, information systems, mathematics, and management science. The book is available in hardcover and eBook formats. The ISBN/price are 9781107173187 / US $ 64.99 and 9781316805350 / US $ 52 for the hardback and eBook respectively.
Guest Column
Authors: Chattopadhyay Eshan
Published: June 2020

Randomness is a valuable resource in computation. Randomness is used to run various Monte Carlo simulations of complex systems such as the stock market or weather prediction systems. Various randomized algorithms have been discovered that often vastly outperform known deterministic counterparts (see [MR10] for examples). Cryptography is another area that crucially relies on access to random bits, and it is known that various basic cryptographic primitives fail to be secure if the quality of the randomness used is poor [DOPS04]. However natural sources of randomness are typically defective. This leads to the following basic question: \Can we efficiently produce truly random bits given access to defective sources of randomness?"
Omega-3 Fatty Acids and Adipose Tissue: Inflammation and Browning
Authors: Kalupahana Nishan Sudheera , Goonapienuwala Bimba Lakmini , Moustaid-Moussa Naima
Published: June 2020

White adipose tissue (WAT) and brown adipose tissue (BAT) are involved in whole-body energy homeostasis and metabolic regulation. Changes to mass and function of these tissues impact glucose homeostasis and whole-body energy balance during development of obesity, weight loss, and subsequent weight regain. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), which have known hypotriglyceridemic and cardioprotective effects, can also impact WAT and BAT function. In rodent models, these fatty acids alleviate obesity-associated WAT inflammation, improve energy metabolism, and increase thermogenic markers in BAT. Emerging evidence suggests that ω-3 PUFAs can also modulate gut microbiota impacting WAT function and adiposity. This review discusses molecular mechanisms, implications of these findings, translation to humans, and future work, especially with reference to the potential of these fatty acids in weight loss maintenance.
What Can We Learn from Experimenting with Survey Methods?
Authors: De Weerdt Joachim , Gibson John , Beegle Kathleen
Published: June 2020

This review covers a nascent literature that experiments with survey design to measure whether the way in which we collect socio-economic data in developing countries influences the data and affects the results of subsequent analyses. We start by showing that survey methods matter and the size of the survey design effects can be nothing short of staggering, affecting basic stylized facts of development (such as country rankings by poverty levels) and conclusions drawn from econometric analyses (such as what the returns to education are or whether small farm plots are more productive than large ones). We describe some of the emerging best practices for conducting survey experiments, including benchmarking against the truth, delving into the error-generating mechanisms, and documenting the costs of different survey approaches.
Eco-Labels: Modeling the Consumer Side
Authors: van 't Veld Klaas
Published: June 2020

The theoretical literature analyzing eco-label programs has focused mainly on how intricate interactions between firms, eco-label certifiers, and regulators shape these programs’ economic and environmental outcomes. Far less attention has been paid to the consumer side, which has typically been modeled very simply. Meanwhile, empirical researchers in behavioral economics, social psychology, and market research have accumulated a large body of empirical evidence that paints a rich, complex picture of that consumer. In this review, I survey a range of these empirical findings, as well as attempts by theorists to incorporate them in their models. The survey is organized around three themes: ( a) varieties of consumer ignorance, ( b) context dependence of consumer motivations, and ( c) motivational spillover effects across time and people. I also touch on the relative importance of private and public benefits of eco-label programs and on the debate over whether the private benefits should even be counted in welfare.
Acute insulin deprivation results in altered mitochondrial substrate sensitivity conducive to greater fatty acid transport
Authors: Miotto Paula M. , Petrick Heather L. , Holloway Graham P.
Published: June 2020

Type 1 and type 2 diabetes are both tightly associated with impaired glucose control. Although both pathologies stem from different mechanisms, a reduction in insulin action coincides with drastic metabolic dysfunction in skeletal muscle and metabolic inflexibility. However, the underlying explanation for this response remains poorly understood, particularly since it is difficult to distinguish the role of attenuated insulin action from the detrimental effects of reactive lipid accumulation, which impairs mitochondrial function and promotes reactive oxygen species (ROS) emission. We therefore utilized streptozotocin to examine the effects of acute insulin deprivation, in the absence of a high-lipid/nutrient excess environment, on the regulation of mitochondrial substrate sensitivity and ROS emission. The ablation of insulin resulted in reductions in absolute mitochondrial oxidative capacity and ADP-supported respiration and reduced the ability for malonyl-CoA to inhibit carnitine palmitoyltransferase I (CPT-I) and suppress fatty acid-supported respiration. These bioenergetic responses coincided with increased mitochondrial-derived H2O2emission and lipid transporter content, independent of major mitochondrial substrate transporter proteins and enzymes involved in fatty acid oxidation. Together, these data suggest that attenuated/ablated insulin signaling does not affect mitochondrial ADP sensitivity, whereas the increased reliance on fatty acid oxidation in situations where insulin action is reduced may occur as a result of altered regulation of mitochondrial fatty acid transport through CPT-I.
Effect of Thymoquinone on Acute Kidney Injury Induced by Sepsis in BALB/c Mice
Authors: Guo Li-Peng , Liu Si-Xu , Yang Qin , Liu Hong-Yang , Xu Lu-Lu , Hao Yu-Hua , Zhang Xiao-Qing
Published: June 2020

Acute kidney injury (AKI) is a common complication of sepsis and has also been observed in some patients suffering from the new coronavirus pneumonia COVID‐19, which is currently a major global concern. Thymoquinone (TQ) is one of the most active ingredients in Nigella sativa seeds. It has a variety of beneficial properties including anti‐inflammatory and antioxidative activities. Here, we investigated the possible protective effects of TQ against kidney damage in septic BALB/c mice. Eight‐week‐old male BALB/c mice were divided into four groups: control, TQ, cecal ligation and puncture (CLP), and TQ+CLP. CLP was performed after 2 weeks of TQ gavage. After 48 h, we measured the histopathological alterations in the kidney tissue and the serum levels of creatinine (CRE) and blood urea nitrogen (BUN). We also evaluated pyroptosis (NLRP3, caspase‐1), apoptosis (caspase‐3, caspase‐8), proinflammatory (TNF‐α, IL‐1β, and IL‐6)‐related protein and gene expression levels. Our results demonstrated that TQ inhibited CLP‐induced increased serum CRE and BUN levels. It also significantly inhibited the high levels of NLRP3, caspase‐1, caspase‐3, caspase‐8, TNF‐α, IL‐1β, and IL‐6 induced by CLP. Furthermore, NF‐κB protein level was significantly decreased in the TQ+CLP group than in the CLP group. Together, our results indicate that TQ may be a potential therapeutic agent for sepsis‐induced AKI.
Bilinear Minimax Optimal Control Problems for a von Kárman System with Long Memory
Authors: Hwang Jin-soo
Published: June 2020

In the present article, we consider a von Kárman equation with long memory. The goal is to study a quadratic cost minimax optimal control problems for the control system governed by the equation. First, we show that the solution map is continuous under a weak assumption on the data. Then, we formulate the minimax optimal control problem. We show the first and twice Fréchet differentiabilities of the nonlinear solution map from a bilinear input term to the weak solution of the equation. With the Fréchet differentiabilities of the control to solution mapping, we prove the uniqueness and existence of an optimal pair and find its necessary optimality condition.
Self-Navigating UAVs for Supervising Moving Objects over Large-Scale Wireless Sensor Networks
Authors: Van Tien Pham , Van Nguyen Pham , Duyen Trung Ha
Published: June 2020

Increasingly inexpensive unmanned aerial vehicles (UAVs) are helpful for searching and tracking moving objects in ground events. Previous works either have assumed that data about the targets are sufficiently available, or they solely rely on on-board electronics (e.g., camera and radar) to chase them. In a searching mission, path planning is essentially preprogrammed before taking off. Meanwhile, a large-scale wireless sensor network (WSN) is a promising means for monitoring events continuously over immense areas. Due to disadvantageous networking conditions, it is nevertheless hard to maintain a centralized database with sufficient data to instantly estimate target positions. In this paper, we therefore propose an online self-navigation strategy for a UAV-WSN integrated system to supervise moving objects. A UAV on duty exploits data collected on the move from ground sensors together with its own sensing information. The UAV autonomously executes edge processing on the available data to find the best direction toward a target. The designed system eliminates the need of any centralized database (fed continuously by ground sensors) in making navigation decisions. We employ a local bivariate regression to formulate acquired sensor data, which lets the UAV optimally adjust its flying direction, synchronously to reported data and object motion. In addition, we also construct a comprehensive searching and tracking framework in which the UAV flexibly sets its operation mode. As a result, least communication and computation overhead is actually induced. Numerical results obtained from NS-3 and Matlab cosimulations have shown that the designed framework is clearly promising in terms of accuracy and overhead costs.
Epidemiological Study of Adamantinoma from US Surveillance, Epidemiology, and End Results Program: III Retrospective Analysis
Authors: Aytekin Mahmut Nedim , Öztürk Recep , Amer Kamil
Published: June 2020

Objective. Adamantinomas are rare low-grade malignant bone tumors. This study aims to describe the demographic characteristics and survival rates of patients suffering from adamantinomas. Methods. The National Institute of Cancer Surveillance, Epidemiology, and Recent Results (SEER) database was used, and patients diagnosed with adamantinoma between 1973 and 2016 were screened. Patients were classified according to sex, age, race/ethnicity, and marital status, and also tumors were classified according to year of diagnosis, laterality, type of treatment, and follow-up. Results. The mean age of patients was 30.8 ± 16.7 (range: 4–75). A total of 92 patients were identified; of these, 43 were females and 49 were males. The mean follow-up period was 138.1 ± 90.3 (range: 1–156) months. Mean survival duration was 287.8 ± 15.4 (95% CI: 257.7–317.9) months. Five- and ten-year survival rates were 98.8% and 91.5%, respectively. Besides, survival time was also observed to be independent of gender, age groups, race, marital status, tumor location, and year of diagnosis. Conclusion. Adamantinoma is a very rare bone tumor that affects the long bones in lower extremities and is more common in men. Five- and 10-year survival prognoses are reasonably satisfactory. Also, survival time is independent of variables such as gender, age, and tumor location.
Adsorptive Desulfurization of Organic Sulfur from Model Fuels by Active Carbon Supported Mn (II): Equilibrium, Kinetics, and Thermodynamics
Authors: Wang Jianhong , Zhang Qi , Yang Hao , Qiao Congzhen
Published: June 2020

Mn (II)/AC adsorbents were prepared by ultrasonic impregnation. The 2 wt. % Mn/AC showed best adsorptive performance, and the optimal adsorption temperature was 313 K. Benzene, methylbenzene, and naphthalene were used to explore the adsorptive selectivity of Mn/AC, indicating that Mn could enhance the adsorptive capacity but could not improve the adsorptive selectivity. The adsorptive mechanism was mostly like to be π-complex. Adsorptive isotherms and kinetics were investigated, and the parameters were calculated. The R2, RMSE, and AICc were used to assess the optimal model. The results showed that Temkin adsorptive isotherm was more suitable to describe the isothermal data; the MPnO kinetics model was more superior to other kinetic models. The order of reaction was between 1 and 2. The outcome of adsorptive thermodynamics indicated that removal of DBT onto Mn/AC was a spontaneous and exothermic process.
Nurses’ Safety in Caring for Tuberculosis Patients at a Teaching Hospital in South West Nigeria
Authors: Fadare Risikat Idowu , Akpor Oluwaseyi Abiodun , Ifechukwude Ifeanyi Goodness , Richard D Agbana , Bello Cecilia Bukola
Published: June 2020

Background. Tuberculosis remains the leading cause of death due to infectious diseases worldwide ranking above HIV/AIDS, and Nigeria is rated as the 7th worldwide and the 2nd in Africa among the 30 countries highly burdened with tuberculosis worldwide. Aim. To investigate the challenges encountered by nurses in the care of TB patients in a Federal Teaching Hospital in Nigeria. Setting. Ekiti State, Southwest Nigeria. Methods. A qualitative contextual method was utilized with the sample size determined by data saturation. Data collection was done through an audiotaped, semistructured interview. The study sample consisted of 20 professional nurses working in the medical and paediatric wards of a selected Federal Teaching Hospital in South West, Nigeria. Data was analysed using Tesch’s content analysis approach. Results. The majority of the participants were females within the age group of 31–40 years. Challenges included inadequate availability of personal protective equipment (PPE), lack of isolation wards, delegating the care of tuberculosis patients to young inexperienced nurses, long process in diagnosing patients with tuberculosis, lack of policies protecting the nurses from exposure to tuberculosis, and inadequate training. The major concern was the fear of contracting tuberculosis. Conclusion. The study suggested that there should be a provision of adequate personal protective equipment; tuberculosis designated wards and provision of periodic training to update the nurses on care of tuberculosis patients. Establishment and execution of hospital policies and practices along with support are equally essential in facilitating a safe workplace for nurses.
Fixed Points of Integral Type Multivalued Contractive Mappings with w-Distance
Authors: Gao Haiyan , Wang Haoyue , Zhang Lili , Zhao Liangshi
Published: June 2020

Two fixed point theorems for multivalued contractive mappings involving w-distance and inequalities of integral type are proved. Our results generalize a few results in the literature. Two illustrative examples are given.
Hormone Replacement Therapy: Lebanese Women’s Awareness, Perception, and Acceptance
Authors: Salame A. Anastasia , Jaffal Mohammad J. , Khalifeh Fatin , Khalife Dalia , Ghazeeri Ghina
Published: June 2020

Objectives. Hormone replacement therapy (HRT) had been the gold standard for the treatment of menopausal symptoms until the publication of the World Health Initiative (WHI) study. After the WHI study, the use of HRT changed among the physicians and patients all over the world despite newer more reassuring data. This study aimed to investigate the knowledge and attitudes of women towards HRT and the factors affecting it for better counseling. Study design. A clinic-based cross-sectional study using a survey was offered to women aged 40 years and above coming to the women’s health center at the American University of Beirut Medical Center (AUBMC) from October 1st, 2017, till March 31st, 2018. The questionnaire included questions about demographics and menopausal symptoms in addition to knowledge and attitudes towards menopause and HRT. Main outcome measures. Our main hypothesis was that women would be aware of HRT as a treatment modality; however, the majority would have a negative attitude towards its usage. Results. The response rate was 87.8%. Seventy-three percent of the respondents had already heard about HRT with 57.9% supporting the use of HRT; however, 47.9% did not know when to use it. The significant predictor for having heard about HRT and a positive attitude towards HRT were having HRT prescribed as a part of treatment and employment status, respectively. Conclusions. Lebanese women are aware of HRT as a treatment option; however, a lack of both proper information and positive attitude towards HRT use was noted.
The Relationship between the Unicost Set Covering Problem and the Attribute Reduction Problem in Rough Set Theory
Authors: Xu Qingyuan , Li Jinjin
Published: June 2020

The unicost set covering problem and the attribute reduction problem are NP-complete problems. In this paper, the relationship between these two problems are discussed. Based on the transformability between attribute reductions and minimal solutions in unicost set covering models, two methods are provided. One is to induce an information table from a given unicost set covering model. With no doubt, it shows that the unicost set covering problem can be investigated by rough set theory. The other is to induce a unicost set covering model from a given information table. Similarly, it shows that the attribute reduction problem can be studied by set covering theory. As an application of the proposed theoretical results, a rough set heuristic algorithm is presented for the unicost set covering problem.
Simvastatin Attenuates Abdominal Aortic Aneurysm Formation Favoured by Lack of Nrf2 Transcriptional Activity
Authors: Kopacz Aleksandra , Werner Ewa , Grochot-Przęczek Anna , Klóska Damian , Hajduk Karolina , Neumayer Christoph , Józkowicz Alicja , Piechota-Polanczyk Aleksandra
Published: June 2020

Surgical intervention is currently the only option for an abdominal aortic aneurysm (AAA), preventing its rupture and sudden death of a patient. Therefore, it is crucial to determine the pathogenic mechanisms of this disease for the development of effective pharmacological therapies. Oxidative stress is said to be one of the pivotal factors in the pathogenesis of AAAs. Thus, we aimed to evaluate the significance of nuclear factor erythroid 2-related factor 2 (Nrf2) transcriptional activity in the development of AAA and to verify if simvastatin, administered as pre- and cotreatment, may counteract this structural malformation. Experiments were performed on mice with inhibited transcriptional activity of Nrf2 (tKO) and wild-type (WT) counterparts. We used a model of angiotensin II- (AngII-) induced AAA, combined with a fat-enriched diet. Mice were administered with AngII or saline for up to 28 days via osmotic minipumps. Simvastatin administration was started 7 days before the osmotic pump placement and then continued until the end of the experiment. We found that Nrf2 inactivation increased the risk of development and rupture of AAA. Importantly, these effects were reversed by simvastatin in tKO mice, but not in WT. The abrupt blood pressure rise induced by AngII was mitigated in simvastatin-treated animals regardless of the genotype. Simvastatin-affected parameters that differed between the healthy structure of the aorta and aneurysmal tissue included immune cell infiltration of the aortic wall, VCAM1 mRNA and protein level, extracellular matrix degradation, TGF-β1 mRNA level, and ERK phosphorylation, but neither oxidative stress nor the level of Angiotensin II Type 1 Receptor (AT1R). Taken together, the inhibition of Nrf2 transcriptional activity facilitates AAA formation in mice, which can be prevented by simvastatin. It suggests that statin treatment of patients with hypercholesterolemia might have not only a beneficial effect in terms of controlling atherosclerosis but also potential AAA prevention.
Soporific Effect of Modified Suanzaoren Decoction and Its Effects on the Expression of CCK‐8 and Orexin‐A
Authors: Zhan Liang-Hui , Dong Ying-Jie , Yang Ke , Lei Shan-Shan , Li Bo , Teng Xi , Zhou Cong , Luo Rong , Yu Qiao-Xian , Jin Hai-Ying , Lv Gui-Yuan , Chen Su-hong
Published: June 2020

Suanzaoren decoction (SZRT), a classic Chinese herbal prescription, has been used as a treatment for insomnia for more than a thousand years. However, recent studies have found no significant effects of SZRT as a treatment for insomnia caused by gastric discomfort. Herein, we studied the effects of modified Suanzaoren decoction (MSZRD) on gastrointestinal disorder‐related insomnia. The main constituents of MSZRD were spinosin (2.21 mg/g) and 6‐feruloylspinosin (0.78 mg/g). A pentobarbital‐induced animal model of insomnia showed that MSZRD shortened sleep latency and prolonged sleep time of the male Institute of Cancer Research (ICR) mice treated for 7 days with oral MSZRD. Sprague‐Dawley male rats were treated daily with oral MSZRD or placebo for 11 days and then deprived of sleep for the last 4 days to establish a model of insomnia. Of note, MSZRD‐treated animals had significantly improved body weight, organ index scores, and fecal moisture relative to placebo‐treated animals, as well as reduced temperature. Sleep‐deprived rats exhibited more exploratory behaviors in an open‐field anxiety test; however, this effect was significantly reduced in MSZRD‐treated animals. We found that MSZRD treatment decreased gastric acid pH, decreased the production of gastrin, pepsin, and Orexin‐A, and increased the expression of MTL and CCK‐8. Importantly, serum GABA concentration was increased by treatment with MSZRD, as reflected by a decreased Glu/GABA ratio. Treated animals had increased the expression of GAD1, GABARA1, and CCKBR but decreased the expression of Orexin R1. In summary, these results suggest that MSZRD has soporific and gastroprotective effects that may be mediated by differential expression of CCK‐8 and Orexin‐A.
Synthesis of a New Polycarboxylate at Room Temperature and Its Influence on the Properties of Cement Pastes with Different Supplementary Cementitious Materials
Authors: Xiang Shuncheng , Gao Yingli , Shi Caijun
Published: June 2020

Three polycarboxylates with different comb structures (i.e., the same degree of polymerization in side chains but different main chains) were synthesized via radical polymerization reaction at room temperature. The effect of polycarboxylates on the surface tension and the flowability in cement pastes was determined. The best product was selected to study its effects on the hydration heat evolution, compressive strength, autogenous shrinkage, and drying shrinkage of cement pastes with different kinds and contents of supplementary cementitious materials. The results showed that with the increase of molar ratio between AA and TPEG to 6 : 1, we could synthesis the best product. When the water‐binder ratio was 0.4, with the increase of polycarboxylates, the cement hydration heat evolution had been slowed down, and the more the dosage was, the more obvious the effect was. Adding supplementary cementitious materials to cement under the same experimental conditions also played a mitigation role in slowing down the hydration heat. When the water‐binder ratio was 0.3, supplementary cementitious materials could increase the strength of cement by 24.5% in maximum; its autogenous shrinkage and drying shrinkage could be decreased, respectively, by 60.1% and 21.9% in the lowest.