bluuebunny/crossref_metadata_2025 huggingface dataset:
Well‐being‐oriented human resource management practices and employee performance in the Chinese banking sector: The role of social climate and resilience
Authors: Cooper Brian , Wang Jue , Bartram Timothy , Cooke Fang Lee
Published: August 2018

Drawing upon positive psychology and a social relational perspective, this article examines the relationship between well‐being‐oriented human resource management (HRM) practices and employee performance. Our multilevel model examines relationships among collectively experienced well‐being‐oriented HRM practices, social climate (characterized by trust, cooperation, and shared codes and language that exist among individuals within the organization), employee resilience, and employee (in‐role) performance. Based on the two‐wave data obtained from 561 employees and their managers within 62 bank branches in 16 Chinese banks, our multilevel analyses provide support for our four hypotheses. First, we found a positive relationship between well‐being‐oriented HRM practices and social climate. Second, social climate mediated the relationship between well‐being‐oriented HRM practices and employee resilience. Third, we found a positive relationship between resilience and employee performance. Finally, employee resilience mediated the relationship between social climate and employee performance. This study is one of the first to unpack the social mechanisms through which well‐being‐oriented HRM practices increase development of resilience and subsequent employee performance at the workplace, namely through influencing group feelings of social climate.
Ecosystem Resilience on Human Terms
Authors: von Stackelberg Katherine
Published: August 2018

Linked socioecological systems consist of economies in societies in nature and make explicit the relationship between the natural environment and human well-being using the language of ecosystem services. A growth-based economy within a constrained biophysical planet (e.g., human activities) has led to a need for ecosystem resilience. Valuation of ecosystem services using the language of economics appears insufficient in the face of human activity. All ecosystems are resilient but will demonstrate that resilience in unexpected and potentially unwanted ways, particularly as human pressures and influences lead to tipping points of extinction (e.g., complete die-off of coral reefs) in these linked socioecological systems. Structured approaches for evaluating the risks, benefits, and impacts of human activities exist but are not effectively applied and when applied, focus on downstream outcomes rather than on upstream actions (e.g., responding to climate change impacts rather than addressing causes of climate change). Ecosystem resilience in the face of unprecedented environmental challenges may not result in the hoped-for set of ecosystem services. Integr Environ Assess Manag 2018;14:598–600. © 2018 SETAC

Key Points

Linked socioecological systems consist of economies in societies in nature and make explicit the relationship between the natural environment and human well-being through the language of ecosystem services. All ecosystems are resilient but will demonstrate that resilience in unexpected and potentially unwanted ways, particularly as human pressures and influences lead to tipping points of extinction (e.g., complete die-off of coral reefs) in these linked socioecological systems. Structured approaches for evaluating the risks, benefits, and impacts of human activities exist but are not effectively applied and when applied, focus on downstream outcomes rather than upstream actions (e.g., responding to pollution impacts rather than addressing causes of pollution). Ecosystem resilience in the face of unprecedented environmental challenges may not result in the hoped-for set of ecosystem services.
Short-term to long-term extrapolation of lethal effects of an herbicide on the marine mysid shrimp Americamysis Bahia by use of the General Unified Threshold Model of Survival (GUTS)
Authors: Gabsi Faten , Solga Andreas , Bruns Eric , Leake Christopher , Preuss Thomas G
Published: August 2018

Risk assessments for plant protection products and their active ingredients that are based on standard laboratory tests performed under constant exposure conditions may result in an overestimation of risks because exposure in the environment is often characterized by a few short peaks. Here, the General Unified Threshold Model of Survival (GUTS) was used to conduct a refined risk assessment for the herbicide tembotrione and its effects on the marine invertebrate Americamysis bahia, for which the standard chronic effect assessment failed. The GUTS model was first calibrated with time-to-effect and concentration–response data from 2 independent acute experiments with A. bahia. Model parameters for both toxicodynamic assumptions of stochastic death (SD) and individual tolerance (IT) were estimated with the reduced GUTS model (GUTS-RED) using the scaled internal concentration as a dose metric. Both the calibrated GUTS-RED-SD and GUTS-RED-IT models described survival dynamics well. Model validation using datasets of 2 independent chronic tests yielded robust predictions of long-term toxicity of tembotrione on A. bahia, with GUTS-RED-IT being more reliable than GUTS-RED-SD. The validated model was subsequently used to predict survival from time-variable exposure profiles, as derived from the FOrum for Co-ordination of pesticide fate models and their USe (FOCUS). Because ecotoxicological independence of peaks had not been empirically verified, the link between exposure and effects was assessed with complete exposure profiles. Effect thresholds resulting from different peak exposure concentrations and durations were determined with GUTS and directly compared with the exposure concentrations from the FOCUS surface water scenarios. The derived values were higher than the predicted FOCUS critical concentrations. Additionally, comparing the areas under the curve (AUCs) derived with GUTS for multiple peak exposure profiles to those from FOCUS revealed significant additional safety margins, demonstrating that only unrealistically high exposure concentrations would produce significant effects. In conclusion, no unacceptable effects of tembotrione on aquatic invertebrates under realistic environmental exposure conditions are expected. Integr Environ Assess Manag 2019;15:29–39. © 2018 SETAC
The Oil and Gas Digital Engineering Journey
Authors: Hause Matthew , Ashfield Steve
Published: August 2018

Model‐based systems engineering (MBSE) is the formalized application of modeling to support system requirements, design, analysis, verification and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases. The INCOSE Integrated Systems Engineering Vision 2025 [INCOSE, 2014] describes how future systems engineering tools will facilitate systems engineering practices as part of a fully integrated engineering environment. A shift towards an integrated, digital engineering environment enables rapid transformation of concepts and designs to digitalized virtual prototypes and then to physical prototypes through the application of additive manufacturing technologies, such as 3D printers and the digital twin in operations. This capability enables engineers to rapidly and continually assess and update their designs prior to committing costs to production hardware.

Implementing this vision will require an integrated suite of tools, technologies, and standards to support the full systems engineering and product lifecycles from requirements to design to implementation and maintenance. MBSE models are digital and executable, and using an MBSE simulation engine, they can shift risk towards early stages of project development as the asset can be tested before it is built. In operations, IoT technologies enable companies to capture and leverage information about a product's performance during operation – with the potential to dramatically improve existing and future products. Service Lifecycle Management (SLM) solutions combine IoT platform technology with service solutions. This integrated closed loop systems engineering toolset applied to the Oil and Gas Industry will ensure success of the Digital Engineering Journey. This paper will describe this Digital Engineering Journey using a Coal Seam Gas example.
Framework for Mission Engineering Competencies
Authors: Hutchison Nicole , Tao Hoong Yan See , Miller William , Verma Dinesh , Vesonder Gregg
Published: August 2018

Mission engineering is the application of systems of systems (SoS) engineering in an operational context. The focus is on execution of the mission and this can often require interoperability across an array of heterogeneous systems. This paper presents research resulting in the identification of the critical skills required to successfully accomplish and shepherd mission engineering. The competency model presented herein uses the grounded theory methodology and leverages the Helix methodology. It is based on a combination of interviews with mission engineers together with research in the open and seminal literature. Subject interviews and open source literature cover 1) mission engineering definition and organizational support, 2) identification of competencies and gaps, and 3) future vision. There is an overlap in mission engineering and systems engineering competencies with important differentiation in 1) governance, 2) foundational math/science/general engineering skills, 3) operational concepts, 4) interpersonal skills, 5) and leadership skills.
Envisioning Systems Engineering as a Transdisciplinary Venture
Authors: Sillitto Hillary , Griego Regina , Arnold Eileen , Dori Dov , Martin James , McKinney Dorothy , Godfrey Patrick , Krob Daniel , Jackson Scott
Published: August 2018

We envision that Systems Engineering (SE) can be transformed into a truly transdisciplinary discipline – a foundational meta‐discipline that supports and enables collaboration between all the disciplines that should be involved in conceiving, building, using and evolving a system so that it will continue to be successful and fit for purpose as time passes. SE can be applied in different ways depending on the situation and how well current SE process patterns are matched to the problem in hand. We identify four elements of this new transdisciplinary framework: SE Tenets; SE Approach; SE Process; and SE Toolbox. We suggest that the use of SE then needs to be considered in three domains: problem space, solution space, and transformation space that helps us along the development‐delivery‐evolution trajectory. We propose twelve SE tenets and show how they should be applied in these three domains. We perceive that even though all elements of the current SE Process can be justified in terms of the twelve tenets applied to these three domains, the current commonly used, standardized SE Process is not suitable for all situations requiring an SE Approach or an application of the SE Tenets. We claim that the framework presented in this paper can act as a unifying structure that facilitates the evolution of Systems Engineering from the current focus on a “standardized” process model suited to a particular class of problem, to a more agile and capable “transdiscipline” that will provide an enabling construct for more successful collaborations that can better deal with a wider range of complicated, complex and chaotic problem situations.
MBSE Applicability Analysis in Chinese Industry
Authors: Lu Jinzhi , Wen Yuejie , Liu Qi , Gürdür Didem , Törngren Martin
Published: August 2018

Model‐based systems engineering (MBSE) is an emerging technique widely used in current industry. It is a leading way expected to become a next generation standard practice in the systems engineering. Fundamental principles of systems engineering can be supported by a model‐based approach to minimize design risks and avoid design changes in late development stages. The models can be used to formalize, analyze, design, optimize, verify and validate target products integrating engineering developments, organizations and products across domains. Though model‐based development is well established in specific domains, such as software, mechanical system, electric systems, its role in integrated development from a system perspective is still a big challenge for current Chinese industry. In this paper, a survey from volunteers related with MBSE is taken by using questionnaires. The purpose of this survey is to highlight the usage and status of MBSE in current Chinese industry and address the rough understandings of MBSE concepts among system developers in China based on the answers about usages, advantages, barriers, concerns, trends of MBSE, particularly the perspective of tool‐chain development.
ADAPTIVE CYBER‐PHYSICAL‐HUMAN SYSTEMS: Exploiting Cognitive Modeling and Machine Learning in the Control Loop
Authors: Madni Azad M. , Sievers Michael , Madni Carla Conaway
Published: August 2018

Cyber‐Physical‐Human (CPH) Systems are purposeful arrangements of sensors, computers, communication devices, and humans to perform tasks that achieve specific mission objectives. These systems typically allow other systems, devices, and data streams to connect/disconnect as needed during mission execution. The roles of humans in CPH systems are quite varied. In adaptive CPH systems, humans collaborate with the cyber‐physical elements to jointly accomplish tasks, and adapt to changing contexts to accomplish mission goals. Mutual adaptation based on prior knowledge, cognitive modeling, and online machine learning are key characteristics of adaptive CPH systems. This paper presents key challenges in realizing adaptive CPH systems. It discusses learning and adaptation, as well as human and CPS roles in adaptive CPH systems. It offers a functional (reference) architecture to inform and guide the development of adaptive CPH systems. It concludes with a discussion of research needed to advance the state‐of‐the‐art of adaptive CPH systems.
Developing Case‐Based Costs Estimation: A Recursive Approach and Case Study
Authors: Zhu Haifeng
Published: August 2018

Today many complex systems are built starting from certain prior products. Traditional cost estimation methods assuming products are built from scratch and using simple methods such as linear regressions can lead to significant errors. This paper studies the switching costs, the costs of developing a new product that is built based upon a previously developed product. It presents a series of systematic study results including its concept, properties, an estimation method, and operation principles. Our approach is an automated method that is able to minimize manual efforts. It can leverage historical data, acquisition information, existing cost models, commercial costing tools, and Expert Judgments (EJ). An HVAC (Heating, Ventilation, and Air Conditioning) system design example case was used to demonstrate our approach.
Implementing the United Nations Sustainable Development Goals for the Systems Engineering of Multinational Corporations
Authors: Brooks Ian , Longhurst James , Kossmann Mario , Odeh Mohammed
Published: August 2018

The United Nations Sustainable Development Goals (SDGs) were adopted in 2015 by 193 countries. They can be characterised as sustainability ‘requirements’ for the global system. This paper provides a vision of how Multinational Companies (MNCs) are likely to experience the SDGs and their implications for Systems Engineering (SE) of the Enterprise. The SDGs do not have the status of international law and may be implemented differently in different countries over the period to 2030. MNCs will face choices about how they wish to comply today in anticipation of future requirements. Thereby, they also have the opportunity to avoid systems sustainability failures later on. This paper presents an initial approach to implementing the SDGs in the form of business requirements. The research will pave the ground for the development of a systematic framework for the adoption, monitoring and assessment of the SDGs in an SE context.
Towards Solving MBSE Adoption Challenges: The D3 MBSE Adoption Toolbox
Authors: Chami Mohammad , Aleksandraviciene Aiste , Morkevicius Aurelijus , Bruel Jean‐Michel
Published: August 2018

Increasing competition drives organizations to continually seek ways to improve the quality of their products and services, time to market and pricing pressures. Model‐Based Systems Engineering (MBSE) promises many benefits to solve document‐based engineering problems. However, the journey of MBSE adoption relies on several human, financial, organizational and technological factors. Organizations that decide to adopt MBSE must be aware of those factors. This paper outlines the MBSE adoption experience of a series of projects and presents an approach to support and guide organizations in overcoming MBSE adoption challenges.
A Tailoring of the Unified Architecture Framework's Meta‐Model for the Modeling of Systems‐of‐Systems
Authors: Tirone Lucio , Guidolotti Emanuele , Fornaro Lorenzo
Published: August 2018

Being used by single companies and by coalitions of governments at the same time, Architecture Frameworks have spread widely as a key tool for the enablement of the Model Based Systems Engineering approach. The Unified Architecture Framework, promoted by the Object Management Group, is rapidly emerging as the reference framework to describe Enterprise Architecture, providing a standard representation for both defense and non‐defense organizations’ architecture descriptions. The work described in the present paper concerns the implementation of a simplified meta‐model, derived as a tailoring of the Unified Architecture Framework's full meta‐model, aimed at allowing the usage of the UAF for the description of System Architectures, rather than Enterprise Architectures. The main UAF View Domains concerned with Systems having the characteristics of Systems‐of‐Systems (Operational, Strategic and Resources), will be analyzed and a solution will be shown to allow a simple implementation of SysML models, as an architectural description of such Systems. A study case will also be presented, developed as a joint effort of Leonardo and Aster for the modeling of naval Combat Systems.
Minimum SysML Representations to Enable Rapid Evaluation using Agent‐Based Simulation
Authors: Maheshwari Apoorv , Raz Ali K. , Dervisevic Aleksandra , Campbell Robert , DeLaurentis Daniel A. , Colligan William , Murphy Andrew , Kolawole Oluwatomi
Published: August 2018

The changing operational requirements and demands for new capabilities, often makes it necessary for systems architects to make substantial changes in a system's architecture. However, the traditional systems engineering processes advocate finalization of architecture at early stages of the design process with little or no change at the later stages of the design. The simulation development is often done towards the end of the design phase and thus, the traditional systems engineering approaches do not support a rapid architecture evolution. In this paper, we propose a Model‐Based Systems Engineering (MBSE) process to facilitate rapid evaluation of changes in a system architecture and/or design artifact for complex systems. This process specifies the minimum set of information that needs to be included in system architecture using SysML diagrams with traceability between the diagrams and agent‐based simulation (ABS) models of a complex system. We demonstrate this SysML‐driven analysis approach to perform a rapid evaluation of evolving system architectures using a NASA‐sponsored project to analyzeab initioarchitectures for the National Airspace System. We also demonstrate how the proposed approach enables early‐on investigation during the architecture development whether an architecture will yield the desired operational benefit.
A Consecutive Condensation, Cyclization, and Dehydration for the Synthesis of Benzimidazopyrroloquinazolines Catalyzed by TsOH
Authors: Wang Yi‐Ping , Ou Xue‐Rong , Wang Yue , Liu Jian‐Quan , Wang Xiang‐Shan
Published: August 2018

A consecutive condensation, cyclization, and dehydration of 2‐(1H‐benzo[d]imidazol‐2‐yl) anilines and ketonic acid in toluene catalyzed by TsOH gave a series of benzo[4,5]imidazo [1,2‐c]pyrrolo[1,2‐a]quinazolin‐3(2H)‐one derivatives in good to high yields. The structure of 3e was further confirmed unambiguously by X‐ray diffraction analysis.
Novel Bridgehead Thiadiazolopyrimidine Derivatives with Antimicrobial and Antitumor Activities
Authors: Azab Mohammad E. , Abdel‐Wahab Salwa S. , Mahmoud Naglaa F. , Elsayed Galal A.
Published: August 2018

Because of the remarkable pharmacodynamics and chemotherapeutics activities of thiadiazolopyrimidines, a new series of 1,3,4‐thiadiazolo[3,2‐a] pyrimidine derivatives have been synthesized by reacting 5‐substituted‐2‐aminothiadiazoles 1a,b with different reagents: active methylenic compounds, benzaldehyde under different conditions, isatin, and cyclic ketones. The structures of the novel compounds have been inferred by spectroscopic methods (infrared, 1H‐NMR, 13C‐NMR, and mass spectrometry) and elemental analyses. The newly synthesized compounds were screened against four bacterial strains (Staphylococcus aureus and Listeria monocytogenes as Gram positive and Pseudomonas aeruginosa and Salmonella typhimurium as Gram negative) and two fungi (Aspergillus niger and Candida albicans) using agar diffusion assay. Most of the compounds showed activity against the tested microorganisms with different extents. The in vitro anticancer activities of these compounds were assessed against four human tumor cell lines; they were found to exhibit different cytotoxic effects. Such results mean that these derivatives can be further utilized as promising anticancer agents.
A morphological study of the male reproductive tract, post‐testicular acrosome maturation and spermatophore formation in the black tiger prawn (Penaeus monodon)
Authors: Feng Tianyi , Paterson Brian , Johnston Stephen
Published: August 2018

Inferior larval production rates of domesticated Penaeus monodon broodstock has been a major hurdle to the expansion of its aquaculture, so that a better understanding of basic male reproductive biology is critical to improve the reproductive performance of this commercially important penaeid species. Following our previous study of spermatogenesis in the species, this study explored the mechanism of spermatophore formation with regards to the contribution of the reproductive tract epithelium by light and transmission electron microscopy. Four types of epithelial secretions (S1–4) were observed contributing to the three layers of the spermatophore. The primary layer of spermatophore was composed of S1 and S2, which were released from the secretory epithelial cells of the proximal vas deferens (PVD) and the secretory epithelial cells of the sperm‐bearing lumen of the mid vas deferens, respectively. The secondary layer of the spermatophore was composed of S3, the secretory product of epithelial cells in the accessory tubule lumen of the mid vas deferens. The outer layer of the spermatophore was formed from S4 which was secreted by the epithelial cells in the posterior mid vas deferens and the terminal ampulla. Unique folds of the vas deferens epithelium appeared to play an important role in the formation of the spermatophore, particularly in the formation of the laminated structure of the spermatophore appendage. With respect to acrosome maturation along the reproductive tract, most spermatozoa did not have a fully developed anterior spike and a subacrosomal region when in the PVD, whereas both structures were fully formed by the time the spermatozoa reached the mid vas deferens and increased electron density when in the terminal ampulla; this observation represents the first morphological evidence of post‐testicular acrosome maturation in this taxon.
The functional anatomy of external genitalia in the black tiger prawn (Penaeus monodon) studied by micro‐computed tomography and scanning electron microscopy
Authors: Feng Tianyi , Paterson Brian , Panagiotopoulou Olga , Green Kathryn , Mardon Karine , Johnston Stephen
Published: August 2018

Although artificial insemination has been used for decades in Penaeus monodon aquaculture, the interaction of male and female external genitalia during spermatophore transfer has not been fully documented. As a result, studying the functional anatomy of this process may help to better refine the insemination technique. The sexual act in penaeoid prawns is virtually impossible to observe directly; as a result, this study aimed to describe the functional anatomy and interaction of external genitalia, such as the petasma, appendices masculinae and genital papillae of the male, with that of the thelycum and genital lobes of the female, using a combination of micro‐computed tomography and scanning electron microscopy. We hypothesise that the spermatophores are ejaculated into the ventromedial groove of the petasma and squeezed by abdominal flexure into the spermathecae of female's thelycum. During this process, the ‘spike‐like’ setae observed on the petasma and appendices masculinae are speculated to control the transferring direction of the spermatophores. The approach of three dimensional remodelling and animation reported in this study may prove useful in the examination of further hypotheses related to the functional anatomy of external genitalia and/or appendages for other crustacean species.
Projected changes in the annual cycle of precipitation over central Asia by CMIP5 models
Authors: Yu Xiaojing , Zhao Yong , Ma Xiaojiao , Yao Junqiang , Li Hongjun
Published: August 2018

Future changes in the annual cycle of the precipitation in central Asia (CA) were estimated based on the historical and representative concentration pathway 8.5 (RCP8.5) experiments from 25 models of the Coupled Model Intercomparison Project phase 5. Compared with the Global Precipitation Climatology Project observations, the historical (1979–1999) experiments showed that most models can capture the migration of rainfall centres, but remarkable discrepancies exist in the location and intensity of rainfall centres between simulations and observations. Considering the skill scores of precipitation and pattern correlations of circulations, which are closely related to the precipitation for each month, for the 25 models, the four best models (e.g., CanESM2, CMCC‐CMS, MIROC5 and MPI‐ESM‐LR) with relatively good performance were selected. The four models' ensemble mean indicated that the migration and location of the precipitation centres were better reproduced, except the intensity of the centres was overestimated, compared with the result that only took the precipitation into consideration. Based on the four best models' ensemble mean under RCP8.5 scenarios, precipitation was projected to increase dramatically over most of the CA region in the boreal cold seasons (November, December, January, February, March and April) and May, with the maximum in December at the end of 21st century (2079–2099), and several positive centres were located in the Pamirs Plateau, the Tianshan Mountains and the northern Himalayas. The precipitation changes were weak in the boreal warm seasons (June, July, August, September and October), with a dry centre located in the Pamirs Plateau and a wet centre in the northern Himalayas. These projected changes can be directly attributed to the overlay of anomalous moisture convergence and evaporation, and other possible mechanisms of dynamic and thermodynamic factors need to be further elucidated.
Assessing the impact of El Niño–Southern Oscillation on South African temperatures during austral summer
Authors: Lakhraj‐Govender Rakhee , Grab Stefan W.
Published: August 2018

Using composite analysis, the timing and extent of El Niño–Southern Oscillation (ENSO) impacts on maximum (Tmax) and minimum temperatures (Tmin) during austral summer are investigated for South Africa over the period 1940–2016. Pearson correlation coefficients determined between temperature data at stations within regions indicate that temperature records are coherent. During austral summer, composite analysis exhibits positive Tmax/Tmin anomalies for El Niño years while negative anomalies are recorded during La Niña years across all regions of South Africa. Statistical significance of composite average temperature anomalies was determined using the Student's t‐test. Tmax for El Niño years are significantly different from the neutral years over the central interior of South Africa for the period 1940–2016. The most notable finding of this study is that El Niño events have had a stronger warming effect during austral summer over many regions in South Africa after the late 1970s, than before. Such an impact has been most prominent over the northern and central interior regions, where, respectively, associated Tmax record an average of 1.1 °C and 0.73 °C higher values for the period 1979–2016 compared to the earlier period (1940–1978). Chi‐squared statistics indicate that ENSO phases exert a stronger influence on temperatures over the interior of South Africa than along the coast.
High‐turbidity events in Western Lake Erie during ice‐free cycles: Contributions of river‐loaded vs. resuspended sediments
Authors: Niu Qianru , Xia Meng , Ludsin Stuart A. , Chu Philip Y. , Mason Doran M. , Rutherford Edward S.
Published: August 2018

High‐turbidity events (HTEs) are common phenomena in shallow‐water environments that can alter ecological interactions. The relative contributions of river input (external loading) vs. resuspension (internal loading) to the occurrence, duration, and influenced areas of HTEs are not fully understood in most systems, owing to the lack of long‐term, source‐specified sediment maps. Using a Finite Volume Community Ocean Model‐based wave‐current forced sediment model, we investigated sediment dynamics in the shallow, river‐dominated Western Lake Erie during ice‐free cycles (April–November) of 2002–2012. Results indicated that wind waves predominated sediment dynamics in the offshore areas, with river discharges causing substantial inshore to offshore gradients. Owing to varying wind waves and river discharges, both the mean and extreme sediment dynamics had distinctive seasonal variations. The basin was turbid during spring and fall, with frequent (> 15%), broad (O [102–103 km2]), and more persistent (means of 3.2/4.4 d during spring/fall) HTEs caused mainly by resuspension events. During summer, the basin was clearer with occasional (< 1%), small (O [1–102 km2]), and short (mean of 1.5 d) HTEs near the mouths generated by pulsing river loadings. Although river loading rarely induced basin‐wide HTEs, they were important during floods, enlarging the high‐turbidity areas by 11.3%. Overall, by delineating the drivers of HTEs in Western Lake Erie, this study furthered the understanding of sediment dynamics in shallow ecosystems and provides a basis for investigating the ecological impact of sediments from different sources in river‐ and wave‐energetic systems.
Nanoparticle–Polymer Synergies in Nanocomposite Hydrogels: From Design to Application
Authors: Chen Tao , Hou Kai , Ren Qianyi , Chen Guoyin , Wei Peiling , Zhu Meifang
Published: August 2018

Hydrogels are an important class of soft materials with high water retention that exhibit intelligent and elastic properties and have promising applications in the fields of biomaterials, soft machines, and artificial tissue. However, the low mechanical strength and limited functions of traditional chemically cross‐linked hydrogels restrict their further applications. Natural materials that consist of stiff and soft components exhibit high mechanical strength and functionality. Among artificial soft materials, nanocomposite hydrogels are analogous to these natural materials because of the synergistic effects of nanoparticle (NP) polymers in hydrogels construction. In this article, the structural design and properties of nanocomposite hydrogels are summarized. Furthermore, along with the development of nanocomposite hydrogel‐based devices, the shaping and potential applications of hydrogel devices in recent years are highlighted. The influence of the interactions between NPs and polymers on the dispersion as well as the structural stability of nanocomposite hydrogels is discussed, and the novel stimuli‐responsive properties induced by the synergies between functional NPs and polymeric networks are reviewed. Finally, recent progress in the preparation and applications of nanocomposite hydrogels is highlighted. Interest in this field is growing, and the future and prospects of nanocomposite hydrogels are also reviewed.
Effect of Semi‐Fluorinated Alkyl Side Chains on Conjugated Polymers with Planar Backbone in Organic Field‐Effect Transistors
Authors: Lee Min‐Hye , Kang Minji , Jeong Hyung‐Gu , Park Jong‐Jin , Hwang Kyoungtae , Kim Dong‐Yu
Published: August 2018

Newly synthesized donor–acceptor (D–A) type of conjugated copolymer (PCTV‐BTzF) with semi‐fluorinated alkyl side chains, which has good solubility in common organic solvents, is described. Unlike polymers with hydrocarbon‐based alkyl side chains, semi‐fluorocabonated polymer leads to intriguing results. First, the self‐organization behavior of the semi‐fluoroalkyl side chains by the self‐aggregate propensity between hydrocarbon and fluorocarbon induces patterned microstructural morphology in polymer films; second, it dominates the molecular orientation of polymers with planar back structure. Such unusual properties of the polymer with semi‐fluoroalkyl side chains compared to that with the hydrocarbon ones are verified and characterized though various systematic characterizations, including temperature‐dependent UV–Vis absorption spectroscopy, atomic force microscopy, and 2D‐grazing incident X‐ray diffraction measurement. As a result, PCTV‐BTzF‐based OFETs show the maximum p‐type field‐effect mobility of 1.02 cm2 V−1 s−1 in the 200 °C annealed films.
Genomic characterization of Nocardia seriolae strains isolated from diseased fish
Authors: Han Hyun‐Ja , Kwak Min‐Jung , Ha Sung‐min , Yang Seung‐Jo , Kim Jin Do , Cho Kyoung‐hee , Kim Tae‐Wook , Cho Mi Young , Kim Byung‐Yong , Jung Sung‐Hee , Chun Jongsik
Published: August 2018

Members of the genus Nocardia are widespread in diverse environments; a wide range of Nocardia species are known to cause nocardiosis in several animals, including cat, dog, fish, and humans. Of the pathogenic Nocardia species, N. seriolae is known to cause disease in cultured fish, resulting in major economic loss. We isolated two N. seriolae strains, CK‐14008 and EM15050, from diseased fish and sequenced their genomes using the PacBio sequencing platform. To identify their genomic features, we compared their genomes with those of other Nocardia species. Phylogenetic analysis showed that N. seriolae shares a common ancestor with a putative human pathogenic Nocardia species. Moreover, N. seriolae strains were phylogenetically divided into four clusters according to host fish families. Through genome comparison, we observed that the putative pathogenic Nocardia strains had additional genes for iron acquisition. Dozens of antibiotic resistance genes were detected in the genomes of N. seriolae strains; most of the antibiotics were involved in the inhibition of the biosynthesis of proteins or cell walls. Our results demonstrated the virulence features and antibiotic resistance of fish pathogenic N. seriolae strains at the genomic level. These results may be useful to develop strategies for the prevention of fish nocardiosis.
Community composition of arbuscular mycorrhizal fungi associated with native plants growing in a petroleum‐polluted soil of the Amazon region of Ecuador
Authors: Garcés‐Ruiz Mónica , Senés‐Guerrero Carolina , Declerck Stéphane , Cranenbrouck Sylvie
Published: August 2018

Arbuscular mycorrhizal fungi (AMF) are worldwide distributed plant symbionts. However, their occurrence in hydrocarbon‐polluted environments is less investigated, although specific communities may be present with possible interest for remediation strategies. Here, we investigated the AMF community composition associated with the roots of diverse plant species naturally recolonizing a weathered crude oil pond in the Amazon region of Ecuador. Next generation 454 GS‐Junior sequencing of an 800 bp LSU rRNA gene PCR amplicon was used. PCR amplicons were affiliated to a maximum‐likelihood phylogenetic tree computed from 1.5 kb AMF reference sequences. A high throughput phylogenetic annotation approach, using an evolutionary placement algorithm (EPA) allowed the characterization of sequences to the species level. Fifteen species were detected. Acaulospora species were identified as dominant colonizers, with 73% of relative read abundance, Archaeospora (19.6%) and several genera from the Glomeraceae (Rhizophagus, Glomus macrocarpum‐like, Sclerocystis, Dominikia and Kamienskia) were also detected. Although, a diverse community belonging to Glomeraceae was revealed, they represented <10% of the relative abundance in the Pond. Seventy five % of the species could not be identified, suggesting possible new species associated with roots of plants under highly hydrocarbon‐polluted conditions.
Threshold behavior in a stochastic HTLV‐I infection model with CTL immune response and regime switching
Authors: Qi Kai , Jiang Daqing
Published: August 2018

We investigate the stochastic HTLV‐I infection model with CTL immune response, which is disturbed by both white and telegraph noises. First, we obtain that the model solution is positive and global. Furthermore, we obtain the existence of ergodic stationary distribution of the solution by stochastic Lyapunov functions with regime switching, and we also establish sufficient conditions for the extinction of system with regime switching. Meanwhile, the threshold
between ergodic property and extinction of the stochastic system is acquired. Finally, our theoretical results are verified by numerical simulation.
Constructing variable coefficient nonlinear integrable coupling super AKNS hierarchy and its self‐consistent sources
Authors: Wei Hanyu , Xia Tiecheng
Published: August 2018

Constructing variable coefficient super integrable equation hierarchy is an important problem in soliton theory. In this letter, new Lax pairs with some arbitrary functions are proposed and a variable coefficient integrable coupling of super AKNS hierarchy is generated. The super Hamiltonian structures of variable coefficient coupling equation hierarchy is derived with the aid of the super trace identity. Furthermore, the self‐consistent sources of variable coefficient super integrable coupling hierarchy are established. It is indicated that this method is an efficient way to construct the variable coefficient super integrable equation hierarchy.
Justification of a quadrature method for an integral equation to the external Neumann problem for the Helmholtz equation
Authors: Khalilov Elnur H. , Aliev Araz R.
Published: August 2018

This work presents a justification of a quadrature method for a hypersingular integral equation to the three‐dimensional external Neumann problem for the Helmholtz equation.
Duhamel's formula for time‐fractional Schrödinger equations
Authors: Zhou Yong , Peng Li , Huang Yunqing
Published: August 2018

In this paper, we consider the time‐fractional order Schrödinger equation that is a fundamental equation in fractional quantum mechanics. By using the spectral theorem, we prove Duhamel's formula and give some properties of solution operators, which can be used to study the local existence and the global existence of time‐fractional Schrödinger equations on a Hilbert space.
Data‐driven respiratory motion compensation for four‐dimensional cone‐beam computed tomography (4D‐CBCT) using groupwise deformable registration
Authors: Riblett Matthew J. , Christensen Gary E. , Weiss Elisabeth , Hugo Geoffrey D.
Published: August 2018

Purpose

To demonstrate the feasibility of using a purely data‐driven, a posteriori respiratory motion modeling and reconstruction compensation method to improve 4D‐CBCT image quality under clinically relevant image acquisition conditions.

Methods

Evaluated workflows that utilized a combination of groupwise deformable image registration and motion‐compensated image reconstruction algorithms. Groupwise registration is an approach that simultaneously registers all temporal frames of a 4D image to a common reference instead of one at a time so as to minimize the influence of any individual time point on the global smoothness or accuracy of the resulting deformation model. Four‐dimensional cone‐beam CT (4D‐CBCT) Feldkamp–Davis–Kress (FDK) reconstructions were registered to either iteratively computed mean respiratory phase (mean‐frame) or preselected respiratory phase (fixed‐frame) reference images to model respiratory motion. The resulting 4D transformations were used to deform projection data during the FDK backprojection operation to create motion‐compensated reconstructions. Tissue interface sharpness (TIS) was defined as the slope of a sigmoid curve fit to a mobile tissue boundary and was used to evaluate image quality in regions susceptible to motion artifacts. Image quality improvement was assessed for 19 clinical cases by evaluating mitigation of view aliasing artifacts, TIS, image noise reduction, and contrast for implanted fiducial markers.

Results

Average (standard deviation) diaphragm TIS recovery relative to initial 4D‐CBCT reconstructions was observed to be 87% (46%) using fixed‐frame registration alone; 87% (47%) using fixed frame with motion‐compensated reconstruction; 101% (68%) using mean‐frame registration alone; and 99% (65%) using mean frame with motion‐compensated reconstruction. Noise was reduced in sampled soft tissue ROIs by 58% for both fixed‐frame registration and registration with motion compensation and by 57% and 58% on average for the corresponding mean‐frame methods, respectively. Average improvement in local CNR was observed to be respectively 93% and 98% for fixed‐frame registration and registration with motion compensation methods and 116% and 111% for the corresponding mean‐frame methods.

Conclusion

Data‐driven groupwise registration and motion‐compensated reconstruction offer a feasible means of improving the quality of 4D‐CBCT images acquired under clinical conditions. The addition of motion compensation reconstruction after groupwise registration visibly reduced the impact of view aliasing artifacts for the clinical image datasets studied.
Reduced order modeling of random linear dynamical systems based on a new a posteriori error bound
Authors: Hossain Md. Nurtaj , Ghosh Debraj
Published: August 2018

Reduced order models (ROMs) are becoming increasingly useful for saving computational cost in response prediction of vibrating systems. In a number of applications such as uncertainty quantification, ROMs require robustness over a wide variation of parameters. Accordingly, often they are classified as local and global, based on their performance in the parametric domain. Availability of an error bound of a ROM helps in achieving this robustness, mainly by allowing adaptivity. In this work, for a linear random dynamical system, first, an a posteriori error bound is developed based on the residual in the governing differential equation. Next, based on this error bound, two adaptive methods are proposed for building robust ROMs, that is, one for local, and another for global. While both methods are based on a greedy search approach, a modification is proposed in the training stage of the global ROM for accelerated convergence. These methods are then applied to an uncertainty quantification problem in a statistical simulation framework, and accordingly, two algorithms are developed. A detailed numerical study on vibration of a bladed disk assembly is conducted to study the accuracy and efficiency of the proposed error bound and adaptive ROMs. It is found that these adaptive ROMs provide a considerable speed‐up in estimating the probability of failure.
Evidence for differences in activity between socioeconomic groups at Kulubnarti, Nubia (550–800 CE), from osseous modifications of the proximal femur
Authors: Lawrence Austin B. , Sandberg Paul A. , Van Gerven Dennis P. , Sponheimer Matt
Published: August 2018

Past bioarchaeological analyses of human remains from the Early Christian Period site of Kulubnarti, Nubia (550–800 CE), have revealed differences in patterns of stress between two contemporaneous cemeteries (mainland [21‐R‐2] and island [21‐S‐46]) that are thought to represent separate socioeconomic groups. However, to this point, differences in activity between cemetery groups and sexes at Kulubnarti have been poorly understood. In this study, we compare patterns of two nonmetric traits (Poirier's facets and plaque) that occur on the proximal femur and have been linked to activity and femoroacetabular impingement (FAI) to better understand activity patterns at Kulubnarti. The remains of 134 adult individuals (252 femora) from two cemeteries at Kulubnarti were analyzed for the presence of Poirier's facet, plaque, and FAI. Frequencies of Poirier's facet and plaque were significantly different between cemeteries and sexes, and Poirier's facet was found only in males. Morphology consistent with FAI was significantly more common in males, and patterns of FAI morphology were different between cemeteries. Patterns in the frequencies of Poirier's facet, plaque, and FAI may indicate a difference in activity between sexes and cemeteries (socioeconomic groups), possibly related to the intensity of agricultural activity. Poirier's facet and plaque may arise via similar processes to FAI in modern athletes or may be different forms of FAI. New work should be undertaken to clarify the etiologies of Poirier's facets and plaque and to better understand their relationship to FAI.
Osteophageous insect damage on human bone from Je'reftheel, a Maya mortuary cave site in west‐central Belize
Authors: Wrobel Gabriel D. , Biggs Jack
Published: August 2018

Human bones from the Maya mortuary cave of Je'reftheel in west‐central Belize show evidence of taphonomic modifications attributed to insects, with termites and dermestid beetles being the most likely culprits. This study represents the first detailed exploration of the effects of osteophageous insects on bones from the Maya area and thus expands on recent efforts by other researchers working in the region to document taphonomic processes and distinguish them from intentional mortuary treatments.
An equivalent approximation approach for the Hamilton‐Jacobi‐Bellman equations in intertemporal decision problems
Authors: Xiang Shengpeng , Chen Shou , He Hongbo
Published: August 2018

In this paper, we develop an equivalent approximation approach to obtain the Hamilton‐Jacobi‐Bellman (HJB) equations of intertemporal decision problems under uncertainty. An implicit discount function is adopted in the derivation of the rate of change of value function for the HJB equations to provide the broadest coverage of time preferences. Meanwhile, we provide an illustrative example for application by revisiting the intertemporal consumption and portfolio decisions problem. Furthermore, we verify the validity of our approach in robustness tests by incorporating exponential, nonconstant, and stochastic hyperbolic discounting functions, respectively. The HJB equations and their resulting decision rules in the finite and infinite planning horizons have confirmed that our approach provides an efficient and reliable alternative to acquire the HJB equations in the intertemporal economic issues under uncertainty.