bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent advances in capillary electrophoresis separation of monosaccharides, oligosaccharides, and polysaccharides
Authors: Mantovani Veronica , Galeotti Fabio , Maccari Francesca , Volpi Nicola
Published: August 2017

This article illustrates the basis and applications of methodologies for the analysis of simple and complex carbohydrates by means of CE. After a description of the most common and novel approaches useful for the analysis and characterization of carbohydrates, this review covers the recent advances in CE separation of monosaccharides, oligosaccharides, and polysaccharides. Various CE techniques are also illustrated for the study of carbohydrates derived from complex glyco‐derivatives such as glycoproteins and glycolipids, essential for biopharmaceutical and glycoproteomics applications as well as for biomarker detection. Most glycans have no significant UV absorption, and derivatization with fluorophore groups prior to separation usually results in higher sensitivity and an improved electrophoretic profile. We also discuss the recent applications and separations by CE of derivatized simple and more complex carbohydrates with different chromophoric active tags. Overall, this review aims to give an overview of the most recent state‐of‐the‐art techniques used in carbohydrate analysis by CE.
Earthquake‐induced structural response output‐only identification by two different Operational Modal Analysis techniques
Authors: Pioldi Fabio , Rizzi Egidio
Published: August 2017

Output‐only system identification is developed here towards assessing current modal dynamic properties of buildings under seismic excitation. Earthquake‐induced structural response signals are adopted as input channels for two different Operational Modal Analysis (OMA) techniques, namely, a refined Frequency Domain Decomposition (rFDD) algorithm and an improved Data‐Driven Stochastic Subspace Identification (SSI‐DATA) procedure. Despite that short‐duration, non‐stationary, earthquake‐induced structural response signals shall not fulfil traditional OMA assumptions, these implementations are specifically formulated to operate with seismic responses and simultaneous heavy damping (in terms of identification challenge), for a consistent estimation of natural frequencies, mode shapes, and modal damping ratios. A linear ten‐storey frame structure under a set of ten selected earthquake base‐excitation instances is numerically simulated, by comparing the results from the two identification methods. According to this study, best up‐to‐date, reinterpreted OMA techniques may effectively be used to characterize the current dynamic behaviour of buildings, thus allowing for potential Structural Health Monitoring approaches in the Earthquake Engineering range.
A damage model for structures with degrading response
Authors: Do Thanh. N. , Filippou Filip. C.
Published: August 2017

The paper presents a hysteretic damage model for the response simulation of structural components with strength and stiffness deterioration under cyclic loading. The model is based on 1D continuum damage mechanics and relates any 2 work‐conjugate response variables such as force‐displacement, moment‐rotation, or stress‐strain. The strength and stiffness deterioration is described by a continuous damage variable. The formulation uses a criterion based on the hysteretic energy and the maximum or minimum deformation for damage initiation with a cumulative probability distribution function for the damage evolution. A series of structural component response simulations showcase the ability of the model to describe different types of hysteretic behavior. The relation of the model's damage variable to the Park‐Ang damage index is also discussed. Because of its consistent and numerically robust formulation, the model is suitable for the large‐scale seismic response simulation of structural systems with strength and stiffness deterioration.
Friendly foes: The evolution of host protection by a parasite
Authors: Ashby Ben , King Kayla C.
Published: August 2017

Hosts are often infected by multiple parasite species, yet the ecological and evolutionary implications of the interactions between hosts and coinfecting parasites are largely unknown. Most theoretical models of evolution among coinfecting parasites focus on the evolution of virulence, but parasites may also evolve to protect their hosts by reducing susceptibility (i.e., conferring resistance) to other parasites or reducing the virulence of coinfecting parasites (i.e., conferring tolerance). Here, we analyze the eco-evolutionary dynamics of parasite-conferred resistance and tolerance using coinfection models. We show that both parasite-conferred resistance and tolerance can evolve for a wide range of underlying trade-offs. The shape and strength of the trade-off qualitatively affects the outcome causing shifts between the minimisation or maximization of protection, intermediate stable strategies, evolutionary branching, and bistability. Furthermore, we find that a protected dimorphism can readily evolve for parasite-conferred resistance, but find no evidence of evolutionary branching for parasite-conferred tolerance, in general agreement with previous work on host evolution. These results provide novel insights into the evolution of parasite-conferred resistance and tolerance, and suggest clues to the underlying trade-offs in recent experimental work on microbe-mediated protection. More generally, our results highlight the context dependence of host-parasite relationships in complex communities.
Development of water content sensor composed of small copper electrodes for use during fire resistance tests of concrete and cement mortar elements
Authors: Lee Jaeyoung , Harada Kazunori , Kwon Youngjin
Published: August 2017

The purpose of this study is to develop a sensor for measuring the water content in concrete and cement mortar elements usable in fire tests. Annealed copper wires were used as electrodes of the water content sensor. Each electrode is 20 mm in length and 0.8 mm in diameter. The separation distance between the electrodes is 2 mm. By measuring the electric resistance, water content can be monitored continuously. Mortar bar specimens were used to calibrate the sensor by measuring electric resistance as a function of water content at a constant temperature of 26°C. The temperature dependence of the electrical resistance was approximated by a functional relationship developed by Ichinose for a similar type of sensor. As a result, a calibration formula was derived for electrical resistances in the range of 1.51 to 2330 kΩ, temperatures in the range of 10 to 175°C, and volumetric water content in the range of 0.084 to 0.201 m3/m3. To verify the applicability, the sensors were embedded in a wall specimen heated by ISO 834 fire for 30 minutes. As a result, it was possible to measure the water contents continuously.
The effect of the trimerization catalyst on the thermal stability and the fire performance of the polyisocyanurate‐polyurethane foam
Authors: Xu Qianwei , Hong Tao , Zhou Zhiping , Gao Jianwu , Xue Liang
Published: August 2017

In this work, 3 currently used trimerization catalysts, TMR‐2 (quaternary ammonium), K‐15 (potassium octoate), and PU‐1792 (potassium acetate) were used to produce rigid polyisocyanurate (PIR) foams with certain amounts of isocyanurate contents. The results from Fourier transform infrared (FTIR) quantitative analysis showed that PU‐1792 had the highest catalytic efficiency in isocyanurate formation. Then, the effect of different amounts of PU‐1792 catalyst on isocyanurate ring output was further investigated, and the result showed that the highest amount of isocyanurate ring formation could be attained by the 5 pphp of PU‐1792 catalyst. It was also found that the increased amount of isocyanurate ring could result in reduced cell size, improved compressive strength, and lowered thermal conductivity of PIR foam. The results from thermogravimetric analysis (TGA) and cone calorimeter (CONE) test revealed that the thermal stability and fire performance of PIR foam could be improved with the increased amount of isocyanurate ring. Furthermore, the CONE test indicated that the smoke production of PIR foam decreased approximately 51.7% in comparison to the reference polyurethane (PU) foam, and the SEM image of char morphology showed that the char of PIR foam was more compact than PU foam.
An efficient antioxidant system and heavy metal exclusion from leaves make Solanum cheesmaniae more tolerant to Cu than its cultivated counterpart
Authors: Branco‐Neves Simão , Soares Cristiano , de Sousa Alexandra , Martins Viviana , Azenha Manuel , Gerós Hernâni , Fidalgo Fernanda
Published: August 2017

Copper (Cu) is an abundant metal in the environment coming from anthropogenic activities and natural sources that, in excess, easily becomes phytotoxic to most species, being its accumulation in plants considered an environmental threat. This study aimed to compare the physiological and molecular responses of Solanum lycopersicum and its wild counterpart Solanum cheesmaniae to Cu stress. In particular, we wanted to address the hypothesis that S. cheesmaniae is more adapted to Cu stress than S. lycopersicum, since the former is equipped with a more efficient antioxidant defense system than the latter. Biomarkers of oxidative status (lipid peroxidation, hydrogen peroxide (H2O2) and superoxide anion () levels) revealed a more pronounced imbalance in the redox homeostasis in shoots of S. lycopersicum than in S. cheesmaniae in response to Cu. Furthermore, the activity of key antioxidant enzymes clearly differed in both species in response to Cu. Catalase (CAT) activity increased in S. cheesmaniae shoots but decreased in the domestic species, as well as ascorbate peroxidase (APX). Both species preferentially accumulated Cu in the radicular system, although a great increase in the aerial parts of S. lycopersicum was measured, while in leaves of Cu‐treated S. cheesmaniae, the levels of Cu were not changed. Overall, results validated the hypothesis that S. cheesmaniae is more tolerant to excess Cu than S. lycopersicum and the data provided will help the development of breeding strategies toward the improvement of the resistance/tolerance of cultivated tomato species to heavy metal stress.
Coupling of finite element method and discontinuous Galerkin method to simulate viscoelastic flows
Authors: Gao Puyang , Ouyang Jie , Zhou Wen
Published: August 2017

In this paper, a numerical method, which is about the coupling of continuous and discontinuous Galerkin method based on the splitting scheme, is presented for the calculation of viscoelastic flows of the Oldroyd‐B fluid. The momentum equation is discretized in time by using the Adams‐Bashforth second‐order algorithm, and then decoupled via the splitting approach. Considering the Oldroyd‐B constitutive equation, the second‐order Runge‐Kutta approach is selected to complete the temporal discretization. As for the spatial discretizations, the fundamental purpose is to make the best of finite element method (FEM) and discontinuous Galerkin (DG) method to handle different types of equations. Specifically speaking, for the subequations, FEM is chosen to treat the Poisson and Helmholtz equations, and DG is employed to deal with the nonlinear convective term. In addition, because of the hyperbolic nature, DG is also utilized to discretize the Oldroyd‐B constitutive equation spatially. This coupled method avoids resorting to extra stabilization technique occurred in standard FEM framework even for moderately high values of Weissenberg number and also reduces the complexity compared with unified DG scheme. The Oldroyd‐B model is applied to investigate several typical and challenging benchmarks, such as the 4:1 planar contraction flow and the lid‐driven cavity flow, with a wide range of Weissenberg number to illustrate the feasibility, robustness, and validity of our coupled method.
Transcription factors—Intricate players of the bone morphogenetic protein signaling pathway
Authors: Ampuja M. , Kallioniemi Anne
Published: August 2017

Bone morphogenetic proteins (BMPs) are a family of growth factors, some of which are known by the name growth and differentiation factor (GDF). BMPs were discovered in the 1960s in an attempt to find factors capable of inducing bone formation. By the end of 1980s, several different BMPs had been found and to date, around 20 members are known. Together with TGFβ, nodal, and activins, they comprise the TGFβ superfamily. BMPs are known to regulate cell fate both in development and adult tissues, and as such they are also involved in many disease states. Understanding the impact of BMPs in these processes requires intimate knowledge of the regulation of the BMP signaling pathway. The intracellular BMP pathway has been studied extensively but the various transcription factors (TFs) necessary for the BMP‐mediated gene expression changes have remained under less scrutiny. Most of the studies have focused on specific TFs in the context of differentiation or development. Varying cell types and BMPs have been used, but no large‐scale studies have yet been performed. Here we aim to summarize the current knowledge on BMP pathway‐related TFs, focusing on those involved in the canonical BMP signaling pathway through the SMAD proteins.
Sequence stratigraphy and depositional system analysis in Paleogene Nanpu Sag: Sequence model and sediment partition
Authors: Jia Haibo , Ji Hancheng , Lu Chaojin , Chen Liang , Yang Xuan , Sun Simin , Zhang Hui
Published: August 2017

In this study, we use 3D seismic, well‐log, and core data to investigate the sequence stratigraphy and facies associations of the Paleogene in the Nanpu Sag, Bohai Bay Basin, East China. Three second‐order sequences—SQEs3‐SQEs2, SQEs1, and SQEd—and 12 third‐order sequences are identified. Fan‐delta, braid‐delta, sublacustrine fan, and lacustrine systems are identified. Four types of tectonic‐induced sequence models are distinguished, which consist of fault‐cliff type, fault‐slope type, axial ramp type, and multiple fault‐terrace type. Sequence architecture of third‐order sequences is dominated by thin lowstand systems tracts with thick transgressive systems tracts (TST) and highstand systems tracts (HST). High‐resolution sediment‐partition pattern analysis shows that a large volume of sediments can be delivered into prodelta/deep‐lacustrine environments during transgressive periods and lake‐level highstand. This study also shows that sand/strata ratios in fan‐delta/braid‐delta front of systems tracts scale have a negative correlation with the subsidence rate, which is demonstrated by the finding that higher subsidence rates correspond to lower sand/strata ratios. This result suggests that subsidence rate has a significant influence on high‐frequency sequences. The occurrence of the high volume of sand‐rich deposits developed in TST and HST and relatively high sand/strata ratios within these sequence units reveal that TST and HST could also have a high hydrocarbon potential. The strongly asymmetrical accommodation generated by an early rapid tectonic subsidence and late tectonic quiescence results in sequence architecture variations between passive‐margin basins and rift basins. Different subsidence rates among different structural belts result in sequence architecture variations within different sequence models.
Dynamic processes and mechanisms for collision to post‐orogenic extension in the Western Dabie Orogen: Insights from numerical modeling
Authors: Dai Liming , Li Sanzhong , Li Zhong‐Hai , Somerville Ian , Liu Xiaochun
Published: August 2017

Post‐orogenic extension is the last stage of a tectonic process towards the end of each Wilson cycle in both ancient and modern continental collisional zones, but their dynamics, controlling factors, and roles for the post‐orogenic extension processes remain debatable. We present the first two‐dimensional thermo‐mechanical numerical model of double sutures inspired by the Western Dabie Orogen to investigate the dynamics of post‐orogenic extension. Our results indicate that the pro‐continent re‐subduction can delay or stop regional extensional deformation and subsequent voluminous magmatic activity caused by slab breakoff in the collision zone. After the end of the collision stage, the re‐subduction slab under the residual lithosphere in the model with lower convergence, as a strong unit, can maintain the gravitational balance of the whole post‐orogen system, whether crust eclogitization is considered or not. If the oceanic crust and micro‐continental crust eclogitization are applied to the model with medium convergence, the lower crust and the residual lithospheric mantle in the collision zone will be completely removed by the gravitational instability and upwelling of asthenospheric mantle. The lithospheric architecture of this model with the medium convergence and crust eclogitization is very similar to the present‐day tomography. However, in the model with higher convergence, lithosphere delamination can occur only by upwelling of asthenosphere, whether crustal eclogitization is considered or not. On the basis of a comparison of numerical results with field data from the Western Dabie Orogen, we suggest that the dynamics of post‐orogenic extension in the Western Dabie Orogen is controlled by re‐subduction of the North China Block and crustal eclogitization after high pressure/ultrahigh pressure collision. Thus, the observed regional extensional deformation and voluminous magmatic activity in the Western Dabie Orogen can be self‐consistently explained by interactions between the two sutures and crustal eclogitization.
Ecological water requirement of plant–soil systems along the Silk Road Economic Belt: A case study of the Guanzhong–Tianshui region, China
Authors: Wang Lixia , Zhang Juan , Liu Zhao , Han Jichang , Mao Zhongan
Published: August 2017

“The Belt and Road” refers to the Silk Road Economic Belt and the 21st‐Century Maritime Silk Road. In this paper, the Guanzhong–Tianshui region is selected as a case study, which is located at the starting point of the Silk Road Economic Belt. First, the spatial distribution maps of plant and soil types are obtained based on the TM remote sensing images and the soil texture data. The boundaries of the third‐level watershed are extracted based on the digital elevation model data. Then the corresponding mathematical models are used to evaluate the ecological water requirements of the plant–soil systems. Also, the spatial distribution characteristics are analysed at the landscape scale and the third‐level watershed scale. The results show that the spatial differences of ecological water requirement in the Guanzhong–Tianshui are obvious. At the plant–soil landscape scale, the ecological water requirement per unit area of the woodland‐clay loam is the highest, about 0.4777 m3/m2, while that of the grassland‐gravel loam is the lowest, about 0.2813 m3/m2. At the third‐level watershed scale, the ecological water requirement per unit area in the Weihe watershed (Jinghezhangjiashan above) is the highest, about 0.4123 m3/m2, while that in the Weihe watershed (Longmen to Sanmenxia) is the lowest, about 0.3002 m3/m2. The study offers scientific references for the regional ecological environment protection and ecosystem management.
Oligodendrocyte RasG12V expressed in its endogenous locus disrupts myelin structure through increased MAPK, nitric oxide, and notch signaling
Authors: Titus Haley E. , López‐Juárez Alejandro , Silbak Sadiq H. , Rizvi Tilat A. , Bogard Madeleine , Ratner Nancy
Published: August 2017

Costello syndrome (CS) is a gain of function Rasopathy caused by heterozygous activating mutations in the HRAS gene. Patients show brain dysfunction that can include abnormal brain white matter. Transgenic activation of HRas in the entire mouse oligodendrocyte lineage resulted in myelin defects and behavioral abnormalities, suggesting roles for disrupted myelin in CS brain dysfunction. Here, we studied a mouse model in which the endogenous HRas gene is conditionally replaced by mutant HRasG12V in mature oligodendrocytes, to separate effects in mature myelinating cells from developmental events. Increased myelin thickness due to decompaction was detectable within one month of HRasG12V expression in the corpus callosum of adult mice. Increases in active ERK and Nitric Oxide (NO) were present in HRas mutants and inhibition of NO synthase (NOS) or MEK each partially rescued myelin decompaction. In addition, genetic or pharmacologic inhibition of Notch signaling improved myelin compaction. Complete rescue of myelin structure required dual drug treatments combining MAPK, NO, or Notch inhibition; with MEK + NOS blockade producing the most robust effect. We suggest that individual or concomitant blockade of these pathways in CS patients may improve aspects of brain function.
The relationship of bilingualism to cognitive decline: The Australian Longitudinal Study of Ageing
Authors: Mukadam Naaheed , Jichi Fatima , Green David , Livingston Gill
Published: August 2017

Objectives

We wished to clarify the link between bilingualism and cognitive decline, and examine whether improved executive function due to bilingualism may be a factor in preventing cognitive decline.

Methods

We used the Australian Longitudinal Study of Ageing which collected data on 2087 participants aged over 65 over 20 years. We compared baseline demographics, health, and social characteristics between bilingual and non‐bilingual participants. We used linear mixed models analysis to explore the effect of bilingualism on MMSE score over time and linear regression to explore the effect of bilingualism on baseline MMSE scores, controlling for pre‐specified potential confounders.

Results

Bilingual participants had lower baseline MMSE scores than the non‐bilingual population (mean difference = −2.3 points; 95% confidence intervals = 1.56–2.90). This was fully explained by education and National Adult Reading Test scores (17.4; standard deviation [SD] =7.7 versus 28.1; SD = 8.2) which also partly explained baseline executive function test scores differences. Bilingual and non‐bilingual participants did not differ in MMSE decline over time (−0.33 points, P = 0.31) nor on baseline tests of executive function (−0.26, P = 0.051).

Conclusions

In this cohort, education rather than bilingualism was a predictor of MMSE score, and being bilingual did not protect from cognitive decline. We conclude that bilingualism is complex, and when it is not the result of greater educational attainment, it does not always protect from cognitive decline. Neuroprotective effects of bilingualism over time may be attributable to the precise patterns of language use but not to bilingualism per se.
Gray matter asymmetries in aging and neurodegeneration: A review and meta‐analysis
Authors: Minkova Lora , Habich Annegret , Peter Jessica , Kaller Christoph P. , Eickhoff Simon B. , Klöppel Stefan
Published: August 2017

Inter‐hemispheric asymmetries are a common phenomenon of the human brain. Some evidence suggests that neurodegeneration related to aging and disease may preferentially affect the left—usually language‐ and motor‐dominant—hemisphere. Here, we used activation likelihood estimation meta‐analysis to assess gray matter (GM) loss and its lateralization in healthy aging and in neurodegeneration, namely, mild cognitive impairment (MCI), Alzheimer's dementia (AD), Parkinson's disease (PD), and Huntington's disease (HD). This meta‐analysis, comprising 159 voxel‐based morphometry publications (enrolling 4,469 patients and 4,307 controls), revealed that GM decline appeared to be asymmetric at trend levels but provided no evidence for increased left‐hemisphere vulnerability. Regions with asymmetric GM decline were located in areas primarily affected by neurodegeneration. In HD, the left putamen showed converging evidence for more pronounced atrophy, while no consistent pattern was found in PD. In MCI, the right hippocampus was more atrophic than its left counterpart, a pattern that reversed in AD. The stability of these findings was confirmed using permutation tests. However, due to the lenient threshold used in the asymmetry analysis, further work is needed to confirm our results and to provide a better understanding of the functional role of GM asymmetries, for instance in the context of cognitive reserve and compensation. Hum Brain Mapp 38:5890–5904, 2017. © 2017 Wiley Periodicals, Inc.
Continuous renal replacement therapy is associated with reduced serum ammonia levels and mortality in acute liver failure
Authors: Cardoso Filipe S. , Gottfried Michelle , Tujios Shannan , Olson Jody C. , Karvellas Constantine J. ,   For the US Acute Liver Failure Study Group
Published: August 2017

Hyperammonemia has been associated with intracranial hypertension and mortality in patients with acute liver failure (ALF). We evaluated the effect of renal replacement therapy (RRT) on serum ammonia level and outcomes in ALF. This was a multicenter cohort study of consecutive ALF patients from the United States ALF Study Group registry between January 1998 and December 2016. First, we studied the association of ammonia with hepatic encephalopathy (HE) and 21‐day transplant‐free survival (TFS; n = 1,186). Second, we studied the effect of RRT on ammonia for the first 3 days post study admission (n = 340) and on 21‐day TFS (n = 1,186). Higher admission (n = 1,186) median ammonia level was associated with grade 3‐4 HE (116 vs. 83 μmol/L) and mortality at day 21 attributed to neurological (181 vs. 90 μmol/L) and all causes (114 vs. 83 μmol/L; P < 0.001 for all). Among 340 patients with serial ammonia levels, 61 (18%) were on continuous RRT (CRRT), 59 (17%) were on intermittent RRT (IRRT), and 220 (65%) received no RRT for the first 2 days. From days 1 to 3, median ammonia decreased by 38%, 23%, and 19% with CRRT, IRRT, and no RRT, respectively. Comparing to no RRT use, whereas ammonia reduction with CRRT was significant (P = 0.007), with IRRT it was not (P = 0.75). After adjusting for year of enrollment, age, etiology, and disease severity, whereas CRRT (odds ratio [OR], 0.47 [95% confidence interval {CI}, 0.26‐0.82]) was associated with reduction in 21‐day transplant‐free all‐cause mortality, IRRT (OR, 1.68 [95% CI, 1.04‐2.72]) was associated with an increase. Conclusion: In a large cohort of ALF patients, hyperammonemia was associated with high‐grade HE and worse 21‐day TFS. CRRT was associated with a reduction in serum ammonia level and improvement of 21‐day TFS. (Hepatology 2018;67:711‐720).
Theory‐of‐Mind development and early sibling relationships after the birth of a sibling: Parental discipline matters
Authors: Song Ju‐Hyun , Volling Brenda L.
Published: August 2017

This study investigated relations among children's Theory‐of‐Mind (ToM) development, early sibling interactions, and parental discipline strategies during the transition to siblinghood. Using a sample of firstborn children and their parents (N = 208), we assessed children's ToM before the birth of a sibling and 12 months after the birth, and sibling interactions (i.e., positive engagement and antagonism) and parental discipline strategies (i.e., child‐centred and parent‐centred discipline) at 4 and 8 months in the first year of siblinghood. Structural equation modelling analyses revealed that children's ToM before the birth of the sibling predicted children's positive engagement with the infant sibling, whereas children's antagonistic behaviours towards the infant sibling negatively predicted children's ToM at 12 months, but only when mothers used low levels of child‐centred discipline. These findings emphasize the role of parents in the development of young children's social‐cognitive understanding in the context of early sibling interactions.

Highlights

This study investigated relations among firstborns' Theory‐of‐Mind (ToM), early sibling relationships, and parental discipline during the first year of siblinghood.

Multigroup analyses showed that ToM predicted higher sibling positive engagement, and early sibling antagonism predicted poorer ToM when mothers used low child‐centred discipline.

Parental discipline plays an important role in the development of young children's social understanding and sibling relationships as early as the first year of siblinghood.
Estimating coastal wetland gain and losses in Galveston County and Cameron County, Texas, USA
Authors: Entwistle Clare , Mora Miguel A , Knight Robert
Published: August 2017

Coastal wetlands serve many important ecological services. One of these important ecological services is their use as storm buffers. Coastal wetlands provide habitat for migratory birds and aquatic species and can improve water quality. In the late 1990s, the US Fish and Wildlife Service (USFWS) published a study outlining the trends of coastal wetlands from the 1950s to early 1990s. In the present study, wetland gains and losses were calculated for Galveston County and Cameron County, Texas, USA, between 2001 and 2011. Maps from the National Land Cover Database were used to determine wetland areas for the years 2001, 2006, and 2011. ArcGIS was used to compare land cover between the study periods to determine overall wetland losses and gains. A statistical analysis was performed between wetland loss and population data to determine whether increased population density led to a higher loss of wetlands. Our analysis indicates that wetland loss is still occurring, however at a lower rate of loss (0.14%–0.18% annually) than the USFWS study predicted earlier (2.7%). In addition, the majority of wetland losses were due to conversion to upland areas. We found a positive correlation between increased population density and decreased wetland area; however, the trend was not significant. The present study shows how the majority of wetland loss in Galveston and Cameron counties is occurring as a result of increased upland areas. In addition, the present study shows that the use of online mapping systems can be used as a low-cost alternative to assess land changes when field tests are not feasible. Integr Environ Assess Manag 2018;14:120–129. © 2017 SETAC

Key Points

Wetland loss is occurring at a slower rate than historically shown along the Texas coast, USA. Aerial photography can be used if field testing is not easily achieved.
By inhibiting PFKFB3, aspirin overcomes sorafenib resistance in hepatocellular carcinoma
Authors: Li Sainan , Dai Weiqi , Mo Wenhui , Li Jingjing , Feng Jiao , Wu Liwei , Liu Tong , Yu Qiang , Xu Shizan , Wang Wenwen , Lu Xiya , Zhang Qinghui , Chen Kan , Xia Yujing , Lu Jie , Zhou Yingqun , Fan Xiaoming , Xu Ling , Guo Chuanyong
Published: August 2017

Hepatocellular carcinoma (HCC) is one of the few cancers with a continuous increase in incidence and mortality. Drug resistance is a major problem in the treatment of HCC. In this study, two sorafenib‐resistant HCC cell lines and a nude mouse subcutaneously tumor model were used to explore the possible mechanisms leading to sorafenib resistance, and to investigate whether aspirin could increase the sensitivity of hepatoma cells to sorafenib. The combination of aspirin and sorafenib resulted in a synergistic antitumor effect against liver tumors both in vitro and in vivo. High glycolysis and PFKFB3 overexpression occupied a dominant position in sorafenib resistance, and can be targeted and overcome by aspirin. Aspirin plus sorafenib induced apoptosis in tumors without inducing weight loss, hepatotoxicity or inflammation. Our results suggest that aspirin overcomes sorafenib resistance and their combination may be an effective treatment approach for HCC.
Challenging Architects in Education: the Smart Environments Integration Project
Authors: Bonnema G. Maarten
Published: August 2017

Educating systems engineers is a challenge. Most attention in literature is on educating systems engineers on the job; after completion of an educational program at university. Architecting is even more difficult because it encompasses dealing with uncertainty, answering a very open problem and integrating disciplines. While on the job training remains important in developing systems engineers and architects, we present in this paper an effort to start this training already in university. We present systems design and engineering as embedded in a university program. The design of, and experiences with, an individual student project aimed at practicing systems architecting is treated. This involves the set‐up of the project, students' results and their experiences.
Defence requires Enterprise‐Level Innovation: Using a Systems Approach to secure superior Value from Ideas
Authors: Wilkinson Mike , Jewell Simon
Published: August 2017

The UK Ministry of Defence (MOD) has embraced innovation as a means of leveraging operational advantage by pulling ideas through to operational capabilities more effectively and efficiently. As a result it has announced the Defence Innovation Initiative (DII) aimed at attracting investment from government and non‐government sources and to improve value for money. This paper explores the challenges associated with delivering enterprise‐level innovation and suggests that holistic systems approaches that are sensitive to the locus of innovation within an enterprise system are needed to secure superior value from ideas. Our early findings show the utility of addressing innovation system coherence through an understanding of the models, constructs and time constants within the innovation landscape when viewed from the perspective of the Operate function within the Defence Operating Model. The insights derived have the potential to inform the approach taken by the UK DII and, by generalisation, the design of innovation systems within the context of any complex adaptive system (CAS).
The U.S. Department of Defense Systems Engineering Competency Model
Authors: Whitcomb Clifford A. , White Corina , Khan Rabia , Grambow Dana , Velez Jose , Delgado Jessica
Published: August 2017

The US Department of Defense has created a comprehensive systems engineering career competency model for use in defense acquisition. The model was developed and verified by a collaborating team with members from the US Office of Personnel Management, Navy, Army, Air Force, Marine Corps, and the Missile Defense Agency to develop and verify the competencies used by defense systems engineers. Verification of the competency model was critical to allow it to be used as a basis for “high stakes” human resource functions for all of the US Department of Defense. The US Deputy Assistant Secretary of the Navy, Research, Development, Test and Evaluation, sponsored the development of the model. This paper presents an outline of the model and an analysis of the contents for critical competencies by experience level and how the model relates to processes in the INCOSE Handbook, Version 4.
Evolving tolerance management for increased robustness of subsea installation operations
Authors: Bryn Lars Petter , Muller Gerrit
Published: August 2017

Low oil prices leads to a need for large cost reductions and improved effectiveness in the subsea oil and gas industry. At the same time, production in harsher environment and deeper water is inducing a need for more complex production systems. Increasing complexity reduces the tolerances for successful manufacturing and installation. Increasing robustness of the installation process can reduce installation costs. Robustness of the installation process is dependent on successful tolerance management. This paper investigates different methods for tolerance management. The conclusion is that successful tolerance management partly is independent on the chosen method for tolerance analysis. The research shows that successful tolerance management relies on understanding of the tolerance chain, cooperation, and early initiation. We applied system modelling as a system engineering approach to support manually calculated tolerance budgets. The research finds that this supports understanding, exploration, and communication. We recommend this as best practice. The research shows that tolerance management can contribute to increased robustness of the installation process by including manufacturing and operational factors in the tolerance analysis. System modelling and budgeting support discussion and exploration of these factors.
Toward Systems Engineering Modeling Standards: Proposed System Architecture Core Model Elements and Composition
Authors: Malone Robert , Herrold John , Friedland Brittany , Green Gregory
Published: August 2017

Through successful employment of large scale Model Based Systems Engineering (MBSE) over many years, The Boeing Company has developed an elaborate data model and associated constraining business rules that form part of its MBSE tool suite specifications. The core elements of this data model and business rule set are presented in this paper as a set of UML 2.0 class diagrams. Advantages inherent in this core data model and business rule set are detailed. These core data model elements and business rules should be applicable to modeling efforts across engineering domains. It is proposed that these core data model elements and business rules be considered for incorporation into an omnibus data model standard and associated constraining business rule standard that reflects the modeling needs of the MBSE community at large. This modeling standard could serve as the basis of an MBSE ontology, as well as the basis of tool suite and data exchange specifications.
Alternate Reality Games in the Systems Engineering Classroom
Authors: Williams Klew , Agloro Alexandrina , Virani Shamsnaz S.
Published: August 2017

What can systems engineers learn from playing a game? As part of a liberal arts and engineering collaborative grant, game designers were recruited to create an Alternate Reality Game (ARG) to be played as an educational activity in a systems engineering course. The purpose of the ARG was to get students to think more deeply about “the diversity of the human in the loop,” or how every best laid engineering plan must take into account the uncertainty of human responses and how they will interact within their system. This paper envisions the classroom as a community and discusses the design process of creating an ARG for a college classroom and the interdisciplinary collaboration that such a process requires.
Developing an Operational Concept Framework to support government policy and regulation on Connected and Automated Vehicles
Authors: Fullalove Richard
Published: August 2017

The connected and automated vehicle (CAV) has experienced rapid capability growth with a related high tempo of innovation. Road and mass public transport authorities have struggled to keep up with this rapid rate of innovation. Every day we see in the news that a vehicle or sub‐system supplier has introduced a new innovative solution to a problem, and that transport authorities have introduced interim (and sometimes ad‐hoc) policy and regulation to govern the test and evaluation or full implementation of CAVs on the road network.

This paper proposes use of an established systems engineering method, the operational concept (OpsCon) as a means to facilitate systematic identification and analysis of “a day in the life” user story for a CAV from a transport authority perspective, and how this method can best be used to review and develop well‐structured public and private transport policy and associated new or altered road regulations to enable the safe and efficient introduction of CAVs on roads.
The Application of MBSE to Inform Workforce Decision Making
Authors: Bransden Thomas , Do Quoc , Farrell Damien , Taylor Stuart
Published: August 2017

A novel application of Model Based Systems Engineering (MBSE) to a workforce context is presented. The DoDAF 2.02 metamodel (DM2) and associated architectural views are used to communicate key workforce information and relationships. This is implemented through a model‐centric system engineering methodology that ensures a common language, traceability, rationale and data integrity. Preliminary results indicate benefits to multiple stakeholders from organisational leaders to human resource professionals. Decisions relating to workforce design, development and realignment can be based on better understanding of interdependencies and traceability to organisational objectives.
Systems Security Engineering: What Every System Engineer Needs to Know
Authors: Nejib Perri , Beyer Dawn , Yakabovicz Edward
Published: August 2017

This paper addresses System Security Engineering (SSE) roles and responsibilities in a framework concept. The framework is a tool to be used with existing guidance for SSE and System Engineering (SE); and, to demonstrate that program protection is not just the responsibility of any one engineer or discipline, it is the responsibility of an entire team. SSE is a specialty engineering discipline of SE. The SSE discipline provides the security approach to SE processes, activities, tasks, products, and artifacts for engineering trustworthy and resilient secure systems. The authors working this project for the INCOSE SSE working group have extensive international experience and exposure including the UK and Australia and have focused their efforts on the international perspective to ensure its relevance and value to the broader international SE community. The framework presented should be leveraged by SEs so they can better understand and integrate SSE into their overall SE processes.
Requirements engineering for radical innovation – Application to helicopter engine fuel system
Authors: Monsimer Adrien , Maré Jean‐Charles , Sicaire Pierre
Published: August 2017

Requirements engineering (RE) is a major step of the System Engineering Process. Thus, when considering radical innovation, this step appears to be crucial to generate original designs. The paper is built around a case study of the helicopter engine fuel system at Safran Helicopter Engines, a major helicopter engines manufacturer. Its fuel system architecture has been incrementally evolving for more than thirty years. In order to anticipate the future expectations of stakeholders, it seems necessary to deeply rethink the fuel system through radical innovation. In this communication, a literature‐based methodology for RE applied to radical innovation is proposed. This methodology has been deployed in an industrial case of a critical embedded power system and provided valuable feedback for adapting and improving the proposed methodology.
System Theoretic Safety Analysis of the Sewol‐Ho Ferry Accident in South Korea
Authors: Kwon Yisug , Leveson Nancy
Published: August 2017

This paper is to show the application of CAST, Causal Analysis based on STAMP (Systems Theoretic Accident Model and Processes) accident analysis tool to investigate the Sewol‐Ho Ferry Accident at the entire maritime transportation sociotechnological system level and to provide the system level safety improvements to the system safety control structure; to show that CAST is an accident analysis tool to effectively and holistically analyze the entire maritime transportation sociotechnological system level disaster; and to show that CAST can provide preventive solutions in a holistic view of top‐down system safety engineering.
Semantically‐enabled Model‐based Systems Engineering of Safety‐critical Network of Systems
Authors: Petnga Leonard , Austin Mark , Blackburn Mark
Published: August 2017

This paper describes a novel approach to the development and integration of semantics to the model‐based systems engineering and operation of safety‐critical network of systems. Engineering models work directly with formal domain and meta‐domain (especially time and space) knowledge that are determinate, provable (ambiguity free) and executable. Knowledge is encoded as semantic blocks, which are an integration of ontologies, rules, and communication and computation interfaces. These concepts are exercised in a collision avoidance problem involving autonomous agents at a traffic intersection.
Model Based Engineering and Product Line Engineering: Combining Two Powerful Approaches at Raytheon
Authors: Young Bobbi , Clements Paul
Published: August 2017

Model based engineering (MBE) refers to a systems engineering approach that employs models as an integral part of a system's engineering stream, providing a formality and semantic rigor that lends itself to analysis and prediction, thus enabling earlier detection of problems. Product line engineering (PLE) is a way to engineer a portfolio of related products in an efficient manner, taking full advantage of the products' similarities while respecting and managing their differences. Raytheon, one of the world's largest defense contractors, is applying PLE and MBE together and combining the benefits of each. This paper will show how Raytheon is using the two methodologies to support each other, and the lessons it is learning as it does so.
Modeling system modes, states, configurations with Arcadia and Capella: method and tool perspectives
Authors: Bonnet Stéphane , Voirin Jean‐Luc , Exertier Daniel , Normand Véronique
Published: August 2017

Management of modes and states is a wide, complex, and often underestimated part of systems engineering. As systems and missions become more complex, the potential combination of modes and states across system, subsystem, and component levels becomes exponential and difficult to master. This paper proposes a methodological approach for studying and integrating the impact of modes and states on the architecture definition. It establishes the concepts of configuration and situation as keys to analyzing these impacts.
System Scenario Selection Method for Faster Analysis
Authors: Ferris Timothy L.J. , Barker Stephen
Published: August 2017

Scenario analysis is a frequently‐used method to explore what a proposed system is required to do in the early phases of system development leading towards finding system requirements. A system which is intended to perform a variety of roles under a range of conditions is likely to result in the need for a quantity of scenarios that becomes intractably pluriform. The consequence of too many scenarios is that either the number of scenarios to be analyzed must be reduced to a manageable number or the analysis is likely to be perfunctory, diminishing the value of the analysis, or the total effort required for the analyses may become unjustifiably great given the value of the project and the risks associated with it. We present a method for reducing the number of scenarios to be analyzed through study of the organization of the factors which distinguish scenarios from each other, and for selecting which scenarios need analysis through identifying their points of commonality and identifying where differences may impact system capability. Our method organizes the types and potential values of factors related to a particular system development in order to reduce the number of scenarios to be investigated. We illustrate our approach with a simple case developed for the purpose of this paper.
Systemic Design Engineering
Authors: Wade Jon , Hoffenson Steven , Gerardo Hortense
Published: August 2017

The Concept Phase of Systems Engineering, also known as Design, is most critical for it determines most of the cost, complexity and value of a system. Given the interdisciplinary nature of Design, it is no wonder that a wide variety of tools and approaches have been developed to aid in addressing design problems. Even within the engineering community, designers from different disciplines working on different types of problems have devised their own frameworks to demystify the design process. This paper describes several major paradigms in designing complex products: design thinking, systems thinking, systemic design, engineering design, and systems engineering. The commonalities and differences, as well as the strengths and weaknesses, of each approach are outlined and discussed, and a unified approach is proposed for designers who seek to leverage the strengths of each of these existing paradigms.