bluuebunny/crossref_metadata_2025 huggingface dataset:
11.5.1 Early Formulation Model‐Centric Engineering on NASA's Europa Mission Concept Study
Authors: Bayer Todd , Chung Seung , Cole Bjorn , Cooke Brian , Dekens Frank , Delp Chris , Gontijo I. , Lewis Kari , Moshir Mehrdad , Rasmussen Robert , Wagner David
Published: November 2014

By leveraging the existing Model‐Based Systems Engineering (MBSE) infrastructure at JPL and adding a modest investment, the Europa Mission Concept Study made striking advances in mission concept capture and analysis. This effort has reaffirmed the importance of architecting and successfully harnessed the synergistic relationship of system modeling to mission architecting. It clearly demonstrated that MBSE can provide greater agility than traditional systems engineering methods. This paper will describe the successful application of MBSE in the dynamic environment of early mission formulation, the significant results produced and lessons learned in the process.
Dependency Analysis in Complex System Design using the FireSat example
Authors: Groß Johannes , Rudolph Stephan
Published: November 2014

Using the FireSat mission from literature (see Larson 1999), the satellite design process is analyzed. Prior to this analysis, the physical and functional properties of the satellite system are encoded in a graph‐based design language. During the automated design language compilation process several graph representations are generated. These graph representations are generated from the design constraints. From the mathematical analysis of the graphs three important interpretations can be derived. The first interpretation concerns the derivation of the exchange rates based on the analysis of the functional coupling. The second interpretation yields a feasible design sequence. Third, a generic backtracking method for resolving engineering design conflicts is presented and illustrated with an antenna example. All three interpretations are illustrated through a detailed view into the FireSat communication subsystem. Furthermore, the demonstration of the method closes with a system‐level analysis of the satellite design process to show its applicability to all levels of detail in system design.
Documents are an Essential Part of Model Based Systems Engineering
Authors: Logan Paul , Harvey David , Spencer Daniel
Published: November 2014

Model Based Systems Engineering (MBSE) existed long before the recent emphasis on its merits compared with traditional document‐based methods. Advocates disparage documents per se, failing to recognise their importance as information artefacts essential to MBSE. While the digital data model may be the ‘source of truth’, stakeholders view, verify, and use the model via screen‐rendered artefacts, which if made permanent to any degree, constitutes ‘printing’ a document. This paper examines the nature and use of documents, both paper and electronic, in traditional and model‐based methodologies, and identifies the evidentiary qualities of paper‐based documents required for legal acceptance of electronic documents. Document templates are used to initially structure the model schema, populate the model, and progressively auto‐generate output documents as complex views on the developed system model. The essential need for documents as information artefacts in gathering, developing, maintaining and reporting the ‘truth’ in a model‐based (and model‐centric) paradigm is demonstrated.
Model‐based Interface Specification for Systems Integration in Systems of Systems Engineering
Authors: Gianni Daniele , D'Ambrogio Andrea , Simone Pierluigi De , Lisi Marco , Luglio Michele
Published: November 2014

The key to enable systems integration is that systems inter‐communications are accurately and unambiguously specified. In line with ongoing Model‐based Systems Engineering (MBSE) initiatives aiming to support systems engineering activities by means of formal and graphical models, we have introduced a logical model for the definition of Interface Communication Modelling Language (ICML), to enable a model‐based approach for interface specification. ICML is based on UML and can potentially be integrated with other systems models in similar forms, e.g., SySML, and with systems of systems models in UPDM or related frameworks. We have designed ICML basing on a preliminary domain analysis on radio signal specifications, with application to space systems. In the analysis, we have specifically considered simple digital and unidirectional signals, and subsequently we have included a method to use ICML for Time‐Division Multiplexed signals. We also present an excerpt of the ICML metamodel and a simple example application.
A Performance‐based Statistical Expert Judgment Model to Assess Technical Performance and Risk
Authors: Eggstaff Justin W. , Mazzuchi Thomas A. , Sarkani Shahram
Published: November 2014

The rapidly changing environment and asymmetric threats currently encountered on the modern battlefield requires the timely delivery of effective weapons systems. Unfortunately in fiscal year 2008, according to the US Government Accountability Office, research and development costs of the United States Department of Defense major weapons acquisition programs increased 42 percent above original estimates, and delays in initial operational capability deliveries slipped to 22 months. While there are several quantitative methods to estimate acquisition program cost and schedule performance and to identify their risks (e.g., Earned Value Management), the estimation of technical performance and technical risk identification is generally heuristic in nature and based on expert judgment because of limited quantitative data for constructive modeling. The proposed research in this paper expands upon the Technical Risk Index Distribution method developed by Lewis, Mazzuchi and Sarkani by incorporating a performance‐based method of mathematically combining quantified expert opinion for technical performance estimation and risk analysis.
A Principle Modeling Framework for Software Intensive Systems
Authors: Tomer Amir
Published: November 2014

A systematic modeling framework for utilizing UML for effective modeling is introduced, keeping consistency and traceability among the various aspects and elements of the system. The proposed framework defines five conceptual decomposition levels for software‐intensive systems modeling, namely, the Business level, the Software‐Intensive System (SWIS) level, the Computer Software Configuration Item (CSCI) level, the Computer Software Component level (CSC) and the Computer Software Unit (CSU) level. Each system‐element at each level is considered a “system‐of‐interest” on its own, while all of them adhere to a unified common definition of the term “system”. In addition, each of the analysis and design levels is associated with integration and testing level, and a consistent modeling between the operational configurations and the testing configurations is introduced. Consideration is also given to modeling of configurations in other stages of the life cycle. The framework has been successfully deployed and proven usable in a graduate level systems engineering course as well as in an undergraduate software engineering course.
Teaching Them How to Fish: Industry‐Focused Student Projects in Systems Engineering
Authors: Valerdi Ricardo , Zonnenshain Avigdor
Published: November 2014

This paper provides an overview of industry‐focused systems engineering team projects for university students. The projects described are from two universities: the University of Arizona (U.S.A.) and Technion (Israel). The role of such projects in teaching and learning of systems engineering is explored, specifically in the context of constructivist learning theory. Characteristics of successful student projects are discussed together with examples of such projects and their resulting artifacts. We conclude by proposing measures of success of such projects.
What's in a Wiki?: Using Collaborative Technology for Developing, Reviewing, and Publishing the Systems Engineering Body of Knowledge (SEBoK)
Authors: Hutchison Nicole , Pyster Arthur , Enck Stephanie , de Koning Hans‐Peter
Published: November 2014

I am rubbish at abstracts. Help?
Managing and understanding complex systems using traceability and open source software
Authors: Brörkens Mark , Gürsoy Ömer
Published: November 2014

Bi‐directional traceability from requirements via architecture and design to code and test and vice versa is identified as a good practice for improving the quality of system development processes. This paper provides methodological guidelines for adding traceability to existing tool chains and proposes an implementation based on open source frameworks.
Model‐Based Systems Engineering as an Enabler for Regulatory Design Compliance
Authors: Dean Jered , Henderson Cody , Gardner John
Published: November 2014

Whether working in the FDA regulated medical field or explosive industrial environments, using model‐based systems engineering provides the confidence, traceability and structure to meet regulatory requirements. In addition, the authors propose the methodology to be a means to optimize schedule predictability and development of the most appropriate products. In this paper, the systems engineering process being employed is briefly described and two case studies are explored that make the case for MBSE as a key enabler of efficient design to complex regulations.
4.2.1 Can Systems Engineering be Agile? Development Lifecycles for Systems, Hardware, and Software
Authors: Carson Ronald S.
Published: November 2014

“Agile” development is alluring because of the promise of shorter cycle times and improved customer satisfaction. Some characteristics of software development and systems (and hardware) development are identified as key differentiators in selecting traditional, plan‐driven vs. agile development. Additional underlying or root reasons are identified to substantiate these differences. These include gated vs. serialized processes, comprehensive vs. incremental system design, independent vs. dependent fabrication, up‐front definition vs. continuous validation, and finish‐to‐start vs. finish‐to‐finish planning and execution. Some additional programmatic and technical criteria are identified for selecting traditional, plan‐driven SE vs. agile methods. The two methods do not appear to be reconcilable when developmental hardware is involved.
Linked Lifecycle Data – Connecting Distributed Engineering Data and harvesting its inherent value
Authors: Fisher Amit , Williams Ben , Matthews Schuyler
Published: November 2014

Systems engineers have many different ways to search, locate and analyze engineering data. However, just like in the days before the World Wide Web, this data is being stored, managed and represented in different proprietary formats and locations that make it hard to discover and analyze. In parallel, search engines and Internet style hyperlinks have been proven to be very powerful technologies that change the way we all find and consume information every day. We believe that adopting a similar technical approach can enable organizations to overcome the complexity inherent in modern product design. In this paper we will review this new approach, named Linked Lifecycle Data, and the new opportunities it presents for improving efficiency, quality and productivity in the design and development of complex products and systems.
5.6.2 A Lean Approach to Improving SE Visibility in Large Operational Systems Evolution
Authors: Turner Richard , Lane Jo Ann , Ingold Dan , Madachy Ray
Published: November 2014

It is often difficult to understand the status of capability development in large operational systems. Schedules are rarely stable. This is due to factors such as: the size and complexity of capabilities; unexpected changes in priorities; depth of supplier chains; variety and availability of special engineering resources; contract structure; and the inherently complex nature of such operations. Lean approaches use the concepts of work in progress (WIP) and capacity to maximize flow through a process. Under certain circumstances, these concepts can be applied to systems engineering and development processes. This paper describes an example implementation of the concept in a large health care system of systems. To enhance both visibility and flow, the approach utilizes visualization techniques, pull‐scheduling processes, and a services approach to systems engineering.
4.2.2 A Framework and Metrics for Addressing an Agile Enterprise
Authors: Harris Pritchett
Published: November 2014

When attempting to design or specify agile solutions for an enterprise with long acquisition timeframes, both the solutions and the enterprise itself must be considered in the same framework to understand the value of time and money spent at one time and performance measured at another. A broad overview of techniques, artifacts, and measurements developed for, and used to, address Enterprise Agility is presented and discussed. Emphasis is placed on treating the distance between both ends of the traditional engineering ‘V’ in a common framework, and on ‘virtual’ feedback between operations and design or portfolio management spaces.
10.1.2 Call for an Effective Alignment of Program Management and Systems Engineering Risk Management Practices
Authors: Arnold Eileen P.
Published: November 2014

Systems Engineering (SE) and Project / Program Management (pM / PM) struggle with Risk Management confusion in organizations embracing certifications of the two disciplines. Some of that confusion may remain even if an organization has standardized on their own Risk Management process if it adds yet another view and language of Risk Management (RM) process and activities. This Call is to encourage the collaboration of multiple organizations and standards committees, citing instances where alignment has been achieved and providing twelve recommendations for exploration of opportunities for improved program and systems engineering RM function. This paper is an elaboration of the RM section of last year's paper, (Arnold, 2012) based on the two certification bases. The Systems Engineering Handbook (Haskins, 2011), the Project Management Body of Knowledge (PMBoK) (PMI, 2008), and the Systems Engineering Body of Knowledge (SEBoK) (Pyster et al, 2012) are explored, with other RM contributors.
Clarifying the Context of SE for the SEBoK
Authors: Boehm Barry , Pyster Art , Olwell David
Published: November 2014

The Systems Engineering Body of Knowledge (SEBoK) (Pyster and Olwell 2012) (see http://www.sebokwiki.org) portion of the Body of Knowledge and Curriculum to Advance Systems Engineering (BKCASE) project (see http://www.bkcase.org) involved three years of extensive and intensive discussions among its 70 authors and over‐200 external reviewers worldwide. These helped the SEBoK effort better understand the implications of various candidate definitions of systems engineering (SE)‐related terms and to shape the resulting SEBoK content. This paper focuses on the resulting clarification of four key aspects of SE: (1) What is the historical context of SE? (2) What is the system boundary of SE? (3) Who are SE's users? and (4) What are the relations among SE and other disciplines?
3.5.1 Model as You Write, or Write as You Model – A Grammar‐Based Approach to Modeling and Documentation
Authors: Yamada Takahiro
Published: November 2014

Model‐Based Systems Engineering (MBSE) is the formalized application of modeling to support activities necessary for development of systems and is expected to replace the document‐centric approach that has been practiced by systems engineers. Many models of systems are being developed by many engineers, but most engineers still write documents in addition to developing models. This is because the semantics of the models is not embedded in the models and is usually provided in documents.

This paper proposes a novel approach to development of documents and models at the same time. In this approach, technical information is encoded with an artificial language. The grammar of this language specifies how the semantics of situations should be encoded into sentences. Generated sentences can be converted to other forms such as diagrams, tables, and/or text in any natural language. Generated sentences can also be converted to electronic data, which can be used by any application program. With this approach, documents can be used as models, too, because documents are written according to strict syntactic and semantic rules. At the same time, models can be used as documents, too, because the semantic information necessary for interpreting models is embedded in the model. This approach can be applied to any technical information, which includes requirement specifications, design specifications, interface specifications, development plans, test plans, test procedures, and operation procedures.
5.2.1 Systems Engineering Complexity in Context
Authors: Sheard Sarah A
Published: November 2014

Systems engineering literature identifies many different kinds of complexity. One paper cataloging complexity for the purpose of modifying systems engineering cost estimates identified more than 30 types. The research described in this paper investigates the idea of sorting and organizing the many concepts of complexity and showing the relationships between them on a single two‐dimensional chart.

The Systems Engineering Complexity Contexts (SECC) chart was developed to show how a large number of complexity concepts relate to systems engineering and to each other. All but two of the 30 types from the paper mentioned above fit on this chart. Those two appear as aspects that may apply to all other boxes on the chart instead of as orthogonal elements, which was the desired representation.
4.5.2 Model Integration – Extracting Value from MBSE
Authors: Broodney Henry , Shani Uri , Sela Aviad
Published: November 2014

Model‐Based Systems Engineering is making its way into the design processes of many Systems builders. But as with any new concept, it must prove its worth by demonstrating significant Return‐On‐Investment. One of the benefits of having designs formalized in models is sharing information, models and data, between designers and teams, and allowing valuable analytics to be performed over that collection of information. This paper will discuss a gradually evolving approach to model integration, sharing and collaboration, from simple indexing and relationship maintenance to comprehensive frameworks for information integration based on the recent advances in ontology‐based data fusion and model transformations.
Developing an Allocation of System of Systems Requirements for Border Security
Authors: Flanigan David , Brouse Peggy
Published: November 2014

During the initial concept development of a System of Systems (SoS) capability, a methodical process is required to develop the SoS requirements and then allocate them to their constituent systems. Review of existing Systems and SoS Engineering requirements literature do not identify such a process. This paper develops a process in order to create the SoS requirements, decompose and allocate them to their systems, develop a model to represent these requirements, and then assess their allocation properties.
A Semantic Framework for Systems Engineering Standards
Authors: Price David , Feeney Allison Barnard , Jones Albert
Published: November 2014

Systems engineers and asset managers create and maintain models of components and systems associated with long‐lived, engineering assets. Component models come from many domains, disciplines and applications. System models typically require integration of these component models. This paper presents the results of an investigation into the convergence of three distinct themes: the growing numbers of standards for engineering data, the maturing of Semantic Web technology, and a framework for architecting and relating engineering vocabularies and data. This investigation sought to determine whether these themes, used together, could enable industry to make significant progress toward model‐based systems engineering in the areas of collaboration, knowledge management, data integration and timely decision making. This paper argues that semantic technologies have matured to the point where they should be the preferred choice for developing future standards and frameworks.
10.4.1 Goals for a New Paradigm of Behavior Modeling
Authors: Brown Barclay
Published: November 2014

The goal of this approach is to develop a new paradigm integrating the practices of business process modeling and use case modeling. These two modeling approaches describe the behavior of organizations and systems, and their interactions, but rest on different paradigms and serve different needs. An integrated approach would have advantages in efficiency, consistency and completeness of the overall behavioral model. In many cases, business process modeling is employed as a precursor to the development of a system to be used in a business organization. Developing a new paradigm and modeling approach that achieves the objectives of both business process modeling and use case modeling in an integrated form, in one analysis pass, should result in time savings, increased accuracy and improved communication. This paper presents a set of goals for the new paradigm and modeling approach.
5.6.1 System Engineering Enabling Transformational Change: Engineering a New Healthcare Ecosystem
Authors: O'Neil Meaghan
Published: November 2014

The healthcare industry is approaching a tipping point, which could lead to a radical transformation from closed system medical devices to a fully interconnected and integrated healthcare ecosystem. In fact, the change catalyst, an engineered future‐state system architecture, is currently under development through the MD PnP program's NIH‐funded Quantum Medical Device Interoperability (QMDI) project. The healthcare industry will require the support and input of systems engineers in the coming years more than ever before. Shared cross industry learning will be crucial for success. This paper provides a perspective on the need for transformative change and outlines the industry's progression towards evolution, including the planned outcomes of the Quantum project.
Systems Processes and Pathologies: Creating An Integrated Framework for Systems Science
Authors: Troncale Len
Published: November 2014

Among the several official projects of the INCOSE Systems Science Working Group, one focuses on integrating the plethora of systems theories, sources, approaches, and tools developed over the past half‐century with the purpose of enabling a new and unified “science” of systems as a fundamental basis for SE. Another seeks to develop a much more SE‐usable Systems Pathology also grounded in a “science” of systems. This paper introduces the wider SE community to the current status of this unique knowledge base produced over the past three years by an INCOSE‐ISSS alliance summarizing the current output of 7 Workshops, 12 Papers, >24 Presentations or Webinars, and 5 Reports. It describes the need for integration of systems knowledge by demonstrating the extensive fragmentation of numerous contributing fields. It presents the current 12‐step “protocol” used by the current group to guide its efforts at synthesis across systems domains, disciplines, tools, and scales asking for feedback to improve the approach. It introduces 15 Working Assumptions or Hypotheses that form the foundation for this attempt at unification citing why these could be used as working principles but why it may be undesirable to call them “principles” as others often do. The paper presents working frameworks for integration and criteria used to judge whether results are a “science” of systems or not with reminders that these early guidelines are being subjected to constant testing and revision. The paper ends with images of the resulting “system” of systems processes theory (SoSPT) and its major spin‐off, the new top‐down Systems Pathology. Fifty‐five key Systems Processes are listed that are dynamically and causally joined by more than 200 Linkage Propositions resulting in a much more detailed general theory of how systems work than previously known. The paper argues these products and the networked community of scholars working on them could prove very useful to future SE design, testing, modeling/simulation, and gradual evolution of better SE understanding of the sustainability, maintenance, and repair of systems of all kinds, far beyond those currently served by SE.
Applied Systems Thinking for Organization Success
Authors: Wilson Mark
Published: November 2014

Systems Engineers are taught to establish formal structures and processes as they manage development activities in an environment framed by detailed schedules and specifications. This tactical orientation can optimize the outcomes of an individual project, but often ignores the long‐term impact on the strategic goals of the parent enterprise system. “Systems thinking” considers the systems in which a project operates and can shift the focus from managing “tasks” using systems engineering to managing the strategic direction of the organization. Addressing projects from a systems perspective while factoring in the role of enabling systems is fundamental to the success of the overall enterprise system, especially in a resource‐constrained environment. Traditional systems engineering training often focuses on methods and tools to execute project tasks; this tutorial helps participants adopt a holistic, systems approach as a logical foundation for decision‐making that benefits the overall enterprise. The tutorial materials provide participants a unique perspective on how to apply systems thinking, systems engineering methods, and quality management principles to the challenge of developing and managing organizational strategy. Participants will explore systems thinking concepts that help them understand how systems interact within the extended enterprise; they will grapple with the practical problems of analyzing organization performance; and they will learn how to select strategic initiatives to maximize organizational benefit. The tutorial is highly interactive, leveraging the participants' own experiences as well as a prepared case study designed to reinforce concepts and give students practical experience in applying systems thinking techniques to organization systems.
On Principles of Complex Systems Engineering‐Complex Systems Made Simple
Authors: White Brian
Published: November 2014

On Principles of Complex Systems Engineering‐Complex Systems Made Simple Systems engineering (SE) activity in System of Systems (SoS), Enterprise Systems Engineering (ESE), and Complex Systems Engineering (CSE) continues to increase. There is still some controversy as to how well conventional methods of SE are able to handle our most difficult complex systems problems, and whether new ways of systems thinking will help. This tutorial will: 1) explain and give examples of complex systems and CSE; 2) review related definitions and terminology; 3) present CSE principles to create “mindsights” that will accelerate progress in your application domains; 4) provide artifacts for characterizing SE environments and what is being done about it; and 5) suggest a methodology for CSE. Teamed class exercises will stimulate creative thought and interactions among participants. The presentation materials and accompanying discussions should deepen our understanding of SE and better prepare us for future SE endeavors.
The System Engineering of Interfaces
Authors: Woodcock Hazel , Davies Paul
Published: November 2014

This course is designed for systems engineering practitioners with some practical experience of requirements specification and / or integration. Some previous experience handling interfaces is desirable, but not essential. If you are newly transferred into systems engineering, this training will provide you with the structure and fundamental skills required to grow in your role. It will also work well as a refresher with challenging exercises for those that are well established as a design authority or systems engineering manager. Unresolved interface issues, and mishandling of interface requirements, are huge cost drivers in today's complex system projects. More than just running through a standard process, the thinking behind best practice and cost avoidance is explained. The course capitalizes as much as possible on the instructors' real‐life experience and from delegates' experiences. It incorporates group work to demonstrate the practices and the difficulties that can arise. The style of the course is interactive, based on an exercise for a hypothetical system, rather than delivered by PowerPoint. However, a set of reference notes and slides will be provided. By the end of the course you will be able to: · Identify necessary interfaces using context diagrams and N‐squared charts · Understand how to separate functional design from interface specification · Flow down system design and external interfaces to subsystems and interfaces between them · Specify the characteristics of interfaces · Plan the negotiation of interfaces with other organisations · Construct a complete and coherent documentation set · Manage changes to the design of interfaces · Plan a testing program for interfaces The tutorial is intended for SE practitioners with some practical experience of requirements and / or integration. Some previous experience handling interfaces is encouraged, but not essential.
Progressive plateau root form dental implant osseointegration: A human retrieval study
Authors: Gil Luiz F. , Suzuki Marcelo , Janal Malvin N. , Tovar Nick , Marin Charles , Granato Rodrigo , Bonfante Estevam A. , Jimbo Ryo , Gil Jose N. , Coelho Paulo G.
Published: November 2014

Although preclinical and sparse human histology retrieval studies have shown that the interface between implant and bone is constantly remodeling, no human retrieval database has been developed to determine the effect of functional loading time and other clinical/implant design variables on osseointegration. The present study tested the hypothesis that bone‐to‐implant contact (BIC) and bone area fraction occupancy (BAFO) increase over functional loading time around dental implants. Due to prosthetic retreatment reasons, 93 human implant retrievals from the same manufacturer (Bicon LLC, Boston, MA, USA) were obtained over a period of approximately 15 years. The retrieved implants were under functional loading from 120 days to ∼18 years and were histomorphologic/metrically evaluated. BIC/BAFO were assessed as a function of multiple independent variables: implant surface type, diameter, length, jaw (maxilla/mandible), region (anterior/posterior), and time of functional loading. The results showed that both BIC and BAFO increased over time independently of implant design/clinical variables, supporting the postulated hypothesis. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1328–1332, 2015.
Disparity in population structuring of Southwestern Willow Flycatchers based on geographic distance, movement patterns, and genetic analyses
Authors: Stumpf Katie J. , Theimer Tad C. , McLeod Mary Anne , Koronkiewicz Thomas J.
Published: November 2014

Estimates of population connectivity often are based on demographic analysis of movements among subpopulations, but this approach may fail to detect rare migrants or overestimate the contribution of movements into populations when migrants fail to successfully reproduce. We compared movement data of endangered Southwestern Willow Flycatchers among isolated populations in Nevada and Arizona from 1997 to 2008 to genetic analyses of samples collected between 2004 and 2008 to determine the degree to which these two methods were concordant in their estimates of population structuring. Given that documented movements of 13 color‐banded adults and 23 juveniles over 10 years indicated low rates of long‐distance movements, we predicted that genetic analyses would show significant population structuring between a northern (Nevada) deme and a southern (Arizona) deme. We genotyped 93 adult individuals at seven microsatellite loci and used two Bayesian clustering programs, STRUCTURE and GENELAND, to predict population structure. Both clustering algorithms produced the same structuring pattern; a cluster containing birds breeding in Pahranagat National Wildlife Refuge, the northern‐most Nevada site, and a cluster comprised of all other populations. These results highlight that estimates of subpopulation connectivity based on demographic analyses may differ from those based on genetics, suggesting either temporal changes in the pattern of movements, the importance of undetected movements, or differential contribution of migrants to the subpopulations they enter. J. Exp. Zool. 321A: 577–585, 2014. © 2014 Wiley Periodicals, Inc.
Ultrastructure of antennal sensilla of the peach aphid Myzus persicae Sulzer, 1776
Authors: Ban Li‐Ping , Sun Yin‐Peng , Wang Ying , Tu Xiong‐Bing , Zhang Shan‐Gan , Zhang Yun‐Ting , Wu Yun‐Sheng , Zhang Ze‐Hua
Published: November 2014

The antennal sensilla of alate Myzus persicae were mapped using transmission electron microscopy and the ultrastructure of sensilla trichoidea, coeloconica, and placoidea are described. Trichoid sensilla, located on the tip of the antennae, are innervated by 2–4 neurons, with some outer dendrites reaching the distal end of the hair. Coeloconic sensilla in primary rhinaria are of two morphological types, both equipped with two dendrites. Dendrites of Type II coeloconic sensilla are enveloped in the dendrite sheath, containing the sensillum lymph. In sensilla coeloconica of Type I, instead, dendrites are enclosed by an electron opaque solid cuticle, with no space left for the sensillum lymph. The ultrastructure of big placoid sensillum reveals the presence of three groups of neurons, with 2–3 dendrites in each neuron group, while both small placoid sensilla are equipped with a single group of neurons, consisting of three dendrites. Both large and small placoid sensilla bear multiple pores on the outer cuticle. The function of these sensilla is also discussed. J. Morphol. 276:219–227, 2015. © 2014 Wiley Periodicals, Inc.
Modern reconstructive techniques for abdominal wall defects after oncologic resection
Authors: Khansa Ibrahim , Janis Jeffrey E.
Published: November 2014

Resection of abdominal wall tumors often leaves patients with debilitating soft tissue defects. Modern reconstructive techniques can be used to restore abdominal wall integrity. In this article, we present an overview of preoperative patient evaluation, analysis of the defect, surgical planning, and the spectrum of available surgical techniques, ranging from simple to complex. The established clinical evidence in the field of abdominal wall reconstruction is summarized and a case example is provided. J. Surg. Oncol. 2015 111:587–598. © 2014 Wiley Periodicals, Inc.
Central nervous system complications after liver transplantation: Common but mostly transient phenomena
Authors: Bernhardt Martina , Pflugrad Henning , Goldbecker Annemarie , Barg‐Hock Hannelore , Knitsch Wolfgang , Klempnauer Jürgen , Strassburg Christian P. , Hecker Hartmut , Weissenborn Karin , Tryc Anita Blanka
Published: November 2014

Although central nervous system complications (CNSCs) are common after orthotopic liver transplantation (OLT), standardized prospective studies are still lacking. This prospective study was aimed at determining the incidence of CNSCs, describing their clinical presentations, and establishing predicting factors. One hundred thirty‐six adult patients who underwent OLT at Hannover Medical School between December 2008 and June 2011 were included. Weekly examinations were performed by a neurologist during the hospital stay after OLT. Patient data, donor data, and operative and postoperative variables were collected. Patients with cerebral dysfunction after OLT underwent a diagnostic work‐up, which included brain imaging and, if necessary, cerebrospinal fluid analysis. Patients with central nervous system (CNS) symptoms but negative imaging and cerebrospinal fluid results and patients with pontine myelinolysis or posterior reversible encephalopathy syndrome were placed in a metabolic‐toxic CNSC group, and patients with strokes, intracranial hemorrhaging, or CNS infections were placed in a nonmetabolic CNSC group. Multiple regression analysis was used to identify independent risk factors for the development of metabolic‐toxic CNSCs. After excluding two patients that died after OLT without regaining consciousness, forty‐four (32.8%) patients developed CNSCs: 37 of these patients (27.6%) had metabolic‐toxic CNSCs, and 7 (5.2%) had nonmetabolic CNSCs. Acute‐on‐chronic liver failure, the number of subsequent surgeries, and primary sclerosing cholangitis were identified as independent predictors for the development of metabolic‐toxic CNSCs. Metabolic‐toxic CNSCs were associated with prolonged hospital stays, and nonmetabolic CNSCs were associated with higher mortality. In conclusion, CNSCs are common and relevant complications after OLT. Patients after OLT, especially with risk factors, should undergo a regular standardized neurological examination that would allow early detection of these complications. Liver Transpl 21:224‐232, 2015. © 2014 AASLD.
Effect of Amphiphilic PCL–PEG Nano‐Micelles on HepG2 Cell Migration
Authors: Shen Yang , Leng Mengtian , Yu Hongchi , Zhang Qin , Luo Xianglin , Gregersen Hans , Wang Guixue , Liu Xiaoheng
Published: November 2014

Uptake of nanoparticles (NPs) affects cell migration but the mechanism remains poorly understood. In this study, the amphiphilic block PCL–PEG nano‐micelles with well‐controlled hydrophilic/hydrophobic chains were used to investigate the effect of internalized nano‐micelles on cancer cell migration. Our results indicated that the nano‐micelles with medium PCL and PEG chains increased expression of Rho GTPases and impeded focal adhesion components. This could enhance Hep G2 cell motility. The nano‐micelles with large PCL and PEG chains showed lower Rho GTPase levels and higher FA components. This is consistent with slower cell migration. Understanding the mechanism of NPs regulating cell behaviors may help the design of efficient drug delivery systems based on polymer micelles.
Illuminating Flash Point: Comprehensive Prediction Models
Authors: Le Tu C. , Ballard Mathew , Casey Phillip , Liu Ming S. , Winkler David A.
Published: November 2014

Flash point is an important property of chemical compounds that is widely used to evaluate flammability hazard. However, there is often a significant gap between the demand for experimental flash point data and their availability. Furthermore, the determination of flash point is difficult and costly, particularly for some toxic, explosive, or radioactive compounds. The development of a reliable and widely applicable method to predict flash point is therefore essential. In this paper, the construction of a quantitative structure – property relationship model with excellent performance and domain of applicability is reported. It uses the largest data set to date of 9399 chemically diverse compounds, with flash point spanning from less than −130 °C to over 900 °C. The model employs only computed parameters, eliminating the need for experimental data that some earlier computational models required. The model allows accurate prediction of flash point for a broad range of compounds that are unavailable or not yet synthesized. This single model with a very broad range of chemical and flash point applicability will allow accurate predictions of this important property to be made for a broad range of new materials.
Compatibilization of PUR/PVAC polymer blend by addition of calcium carbonate filler
Authors: Vrsaljko Domagoj , Bao Xujin
Published: November 2014

The influence of untreated and stearic acid surface pretreated calcium carbonate (CaCO3) nanofiller (U1 – untreated CaCO3 and U1S2 – stearic acid treated CaCO3) on the properties of polyurethane/poly(vinyl acetate) (PUR/PVAC) polymer blends was investigated. Adhesion between fillers and polymers in the polymer blend composite, and filler position in regard to the polymer phases, are predicted on the basis of calculated adhesion parameters and wetting factor ωa of PUR, PVAC, U1, and U1S2. U1 is located in the PUR matrix phase and U1S2 is located at the interface between matrix PUR domain and dispersed PVAC domain. Polymer blend composites with predominant U1S2 showed lower tensile strength and elongation compared to these of polymer blend composites with predominant U1 mainly due to the fillers' different surface properties, which confirmed that the mechanical properties of polymer blend composites were dependent on overall system morphology rather than the filler location. POLYM. COMPOS. 37:1274–1281, 2016. © 2014 Society of Plastics Engineers
Vibrational entropy differences between mesophile and thermophile proteins and their use in protein engineering
Authors: Frappier Vincent , Najmanovich Rafael
Published: November 2014

We recently introduced ENCoM, an elastic network atomic contact model, as the first coarse‐grained normal mode analysis method that accounts for the nature of amino acids and can predict the effect of mutations on thermostability based on changes vibrational entropy. In this proof‐of‐concept article, we use pairs of mesophile and thermophile homolog proteins with identical structures to determine if a measure of vibrational entropy based on normal mode analysis can discriminate thermophile from mesophile proteins. We observe that in around 60% of cases, thermophile proteins are more rigid at equivalent temperatures than their mesophile counterpart and this difference can guide the design of proteins to increase their thermostability through series of mutations. We observe that mutations separating thermophile proteins from their mesophile orthologs contribute independently to a decrease in vibrational entropy and discuss the application and implications of this methodology to protein engineering.
Maize (Zea mays) seeds can detect above‐ground weeds; thiamethoxam alters the view
Authors: Afifi Maha , Lee Elizabeth , Lukens Lewis , Swanton Clarence
Published: November 2014

BACKGROUND

Far red light is known to penetrate soil and delay seed germination. Thiamethoxam as a seed treatment has been observed to enhance seed germination. No previous work has explored the effect of thiamethoxam on the physiological response of buried maize seed when germinating in the presence of above‐ground weeds. We hypothesised that the changes in red:far red reflected from above‐ground weeds would be detected by maize seed phytochrome and delay seed germination by decreasing the level of GA and increasing ABA. We further hypothesised that thiamethoxam would overcome this delay in germination.

RESULTS

Thiamethoxam enhanced seed germination in the presence of above‐ground weeds by increasing GA signalling and downregulating DELLA protein and ABA signalling genes. An increase in amylase activity and a degradation of starch were also observed.

CONCLUSIONS

Far red reflected from the above‐ground weeds was capable of penetrating below the soil surface and was detected by maize seed phytochrome. Thiamethoxam altered the effect of far red on seed germination by stimulating GA and inhibiting ABA synthesis. This is the first study to suggest that the mode of action of thiamethoxam involves both GA synthesis and ABA inhibition. © 2014 Society of Chemical Industry
Linear instability of warm core, constant potential vorticity, eddies in a two‐layer ocean
Authors: Cohen Yair , Dvorkin Yona , Paldor Nathan
Published: November 2014

Linear instability of warm‐core eddies of constant potential vorticity (PV) is studied in a two layer, finite depth, shallow‐water ocean. The basic state flow in the constant PV eddy that obeys the gradient balance cannot be described by explicit expressions and can be solved only numerically. The various cases of gradient balance are classified by constructing a canonical formulation that relates any PV value to a value of the angular velocity that has to prevail near the centre of the constant PV eddy. The growth rates of perturbations imposed on the basic state are calculated for a variety of values of the (constant) PV and the depth of the surrounding ocean. The growth‐rates, i.e. the eigenvalues, are calculated numerically by using a shooting to fitting point method which guarantees that the corresponding eigenfunctions are regular at all singular points. The maximal growth rates are contoured as functions of the PV and ocean depth for azimuthal wavenumbers 2 and 3 and the maximum of these growth rates is of the order of 1 day, which is similar to that of a solidly rotating eddy. The range of angular velocity and ocean depth where the constant PV eddy is unstable, however, is greatly reduced compared with that of a solidly rotating eddy. The instabilities found here are classified in terms of wave–wave interactions by comparing our results in each PV value with the known instabilities of the solidly rotating eddy with the same angular velocity. In the constant PV eddy the Baroclinic instability is filtered out and the range of angular velocity where the Hybrid instability exists is significantly reduced. All instabilities decay monotonically with the increase in ocean depth.
Event‐triggered control for networked Markovian jump systems
Authors: Wang Huijiao , Shi Peng , Lim Cheng‐Chew , Xue Qianqian
Published: November 2014

The problem of H∞ control for networked Markovian jump system under event‐triggered scheme is studied in this paper. In order to reduce the utilization of limited network bandwidth, a dynamic discrete event‐triggered scheme to choose the transmitted data is designed. A Markovian jump time‐delay system model is employed to describe the event‐triggered scheme and the network related behavior, such as transmission delay, data package dropout, and disorder. Furthermore, a sufficient condition is derived to guarantee that the resulting closed‐loop system is stable and has a prescribed performance index. A co‐design method for the H∞ controller and the event‐triggered scheme is then proposed. The effectiveness and potential of the theoretic results obtained are illustrated by a simulation example. Copyright © 2014 John Wiley & Sons, Ltd.
Production and characterization of raw starch degrading enzyme from a newly isolated thermophilic filamentous bacterium, Laceyella sacchari LP175
Authors: Lomthong Thanasak , Chotineeranat Sunee , Kitpreechavanich Vichien
Published: November 2014

Medium optimization for production of raw starch degrading enzyme (RSDE) from a newly isolated thermophilic filamentous bacterium, Laceyella sacchari LP175, is described. Yeast extract and raw cassava starch were found to be the best nitrogen and carbon sources, respectively, for enzyme production. Response surface methodology with Plackett–Burman design and central composite design showed that an optimized concentration of 4.93 g/L raw cassava starch and 2.8 g/L yeast extract in basal medium yielded 181.1 U/mL RSDE activity in a shaking flask at 50°C and pH 7.0 after 48 h. Maximum RDSE activity in crude enzyme was achieved at pH 6.5 and 50°C. The major end product of raw cassava starch hydrolysis was maltose (88%). The Km and Ki values of raw cassava starch and maltose, respectively, were found to be 2.85 mg/mL and 1.04 mg/mL. Raw cassava starch at 100 g/L was hydrolyzed with 200 U/mL RSDE for 12 h, yielding 36.8% hydrolysis. The addition of commercial glucoamylase (1.6 U/mL) synergistically enhanced the hydrolysis reaction, yielding 70% hydrolysis (equivalent to 78.0 g/L glucose). The high efficiency of RSDE produced from L. sacchari LP175 could be useful for replacing conventional enzymes currently used in various raw starch processing industries.