bluuebunny/crossref_metadata_2025 huggingface dataset:
Postprandial C-Peptide to Glucose Ratio as a Marker of β Cell Function: Implication for the Management of Type 2 Diabetes
Authors: Saisho Yoshifumi
Published: May 2016

C-peptide is secreted from pancreatic β cells at an equimolar ratio to insulin. Since, in contrast to insulin, C-peptide is not extracted by the liver and other organs, C-peptide reflects endogenous insulin secretion more accurately than insulin. C-peptide is therefore used as a marker of β cell function. C-peptide has been mainly used to assess the presence of an insulin-dependent state for the diagnosis of type 1 diabetes. However, recent studies have revealed that β cell dysfunction is also a core deficit of type 2 diabetes, and residual β cell function is a key factor in achieving optimal glycemic control in patients with type 2 diabetes. This review summarizes the role of C-peptide, especially the postprandial C-peptide to glucose ratio which likely better reflects maximum β cell secretory capacity compared with the fasting ratio in assessing β cell function, and discusses perspectives on its clinical utility for managing glycemic control in patients with type 2 diabetes.
Multilingual Language Mixing and Creativity
Authors: Bhatia Tej , Ritchie William
Published: May 2016

The aim of this paper is to explore a facet of bi/multilingual creativity in language mixing. The first aspect of creativity is driven by the consideration of formal principles, which fall outside monolingual or single language competence, e.g., [1]. The rule-governed mechanism, which allows the integration of the embedded language verbs into the matrix language, is accounted for. This objective is achieved by employing two distinct data sets: (1) grammatical competence (intuitional data) involving the embedded lexical verb mixing in the Light Verb Construction in a variety of languages, particularly in South Asian languages (e.g., Hindi-English); and (2) an experimental data set that exhibits the relationships involved in the generative perspective through consideration of Universal Grammar. The underlying motivation for focusing on India is that language mixing constitutes a grass-roots phenomenon in India since the pre-Christian era; hence it is a stable and time-tested phenomenon which allows us to overcome key methodological issues in the study of language mixing.
Surface Functionalization of Polyethersulfone Membrane with Quaternary Ammonium Salts for Contact-Active Antibacterial and Anti-Biofouling Properties
Authors: Hu Xiao , Lin Xiaohui , Zhao Huabing , Chen Zihao , Yang Jian , Li Fan , Liu Changjun , Tian Feng
Published: May 2016

Biofilm is a significant cause for membrane fouling. Antibacterial-coated surfaces can inhibit biofilm formation by killing bacteria. In this study, polyethersulfone (PES) microfiltration membrane was photografted by four antibiotic quaternary ammonium compounds (QACs) separately, which were synthesized from dimethylaminoethyl methacrylate (DMAEMA) by quaternization with butyl bromide (BB), octyl bromide (OB), dodecyl bromide (DB), or hexadecyl bromide (HB). XPS, ATR-FTIR, and SEM were used to confirm the surfaces’ composition and morphology. After modification, the pores on PES-g-DMAEMA-BB and PES-g-DMAEMA-OB were blocked, while PES-g-DMAEMA-DB and PES-g-DMAEMA-HB were retained. We supposed that DMAEMA-BB and DMAEMA-OB aggregated on the membrane surface due to the activities of intermolecular or intramolecular hydrogen bonds. Bacteria testing found the antibacterial activities of the membranes increased with the length of the substituted alkyl chain. Correspondingly, little bacteria were observed on PES-g-DMAEMA-DB and PES-g-DMAEMA-HB by SEM. The antifouling properties were investigated by filtration of a solution of Escherichia coli. Compared with the initial membrane, PES-g-DMAEMA-DB and PES-g-DMAEMA-HB showed excellent anti-biofouling performance with higher relative flux recovery (RFR) of 88.3% and 92.7%, respectively. Thus, surface functionalization of the PES membrane with QACs can prevent bacteria adhesion and improve the anti-biofouling activity by the contact-active antibacterial property.
Antitumor Effect of the Mannich Base(1,3-bis-((3-Hydroxynaphthalen-2-yl)phenylmethyl)urea) on Hepatocellular Carcinoma
Authors: Vedarethinam Vadanasundari , Dhanaraj Karthik , Ilavenil Soundharrajan , Arasu Mariadhas , Choi Ki , Al-Dhabi Naif , Srisesharam Srigopalram , Lee Kyung , Kim Da , Dhanapal Tamilvenvendan , Sivanesan Ravikumar , Choi Han , Kim Young
Published: May 2016

The present study was designed to evaluate the antitumor effects of the synthetic Mannich base 1,3-bis-((3-hydroxynaphthalen-2-yl)phenylmethyl)urea (1,3-BPMU) against HEP-G2 hepatoma cells and diethylnitrosamine (DEN)-induced hepatocarcinoma (HCC) in albino rats. In vitro analysis results revealed that 1,3-BPMU showed significant cytotoxicity and cell growth inhibition in HEP-G2 hepatoma cells in a concentration-dependent manner. Furthermore, flow cytometry results indicated that 1,3-BPMU enhanced early and late apoptosis. The maximum apoptosis was exhibited at a concentration of 100 μg/mL of 1,3-BPMU. In in vivo analysis, DEN treatment increased the content of nucleic acids, LPO and the activities of AST, ALT, ALP, LDH, γGT and 5’NT with decreased antioxidant activity as compared to control rats. However, 1,3-BPMU treatment to DEN-induced rats decreased the content of nucleic acids, LPO and the activities of AST, ALT, ALP, LDH, γGT and 5’NT and increased the activities of SOD, CAT, GPx, GST and GR (p < 0.05). Furthermore, 1,3-BPMU enhanced the apoptosis via upregulation of caspase-3 and caspase-9 and the downregulation of Bcl-2 and Bcl-XL mRNA expression as compared to DEN-induced rats. Histological and ultrastructural investigation showed that 1,3-BPMU treatment renovated the internal architecture of the liver in DEN-induced rats. In this study, the molecular and pre-clinical results obtained by treatment of DEN-induced rats with 1,3-BPMU suggested that 1,3-BPMU might be considered as an antitumor compound in the future.
Supramolecular Nanostructures Based on Cyclodextrin and Poly(ethylene oxide): Syntheses, Structural Characterizations and Applications for Drug Delivery
Authors: Zheng Yue , Wyman Ian
Published: May 2016

Cyclodextrins (CDs) have been extensively studied as drug delivery carriers through host–guest interactions. CD-based poly(pseudo)rotaxanes, which are composed of one or more CD rings threading on the polymer chain with or without bulky groups (or stoppers), have attracted great interest in the development of supramolecular biomaterials. Poly(ethylene oxide) (PEO) is a water-soluble, biocompatible polymer. Depending on the molecular weight, PEO can be used as a plasticizer or as a toughening agent. Moreover, the hydrogels of PEO are also extensively studied because of their outstanding characteristics in biological drug delivery systems. These biomaterials based on CD and PEO for controlled drug delivery have received increasing attention in recent years. In this review, we summarize the recent progress in supramolecular architectures, focusing on poly(pseudo)rotaxanes, vesicles and supramolecular hydrogels based on CDs and PEO for drug delivery. Particular focus will be devoted to the structures and properties of supramolecular copolymers based on these materials as well as their use for the design and synthesis of supramolecular hydrogels. Moreover, the various applications of drug delivery techniques such as drug absorption, controlled release and drug targeting based CD/PEO supramolecular complexes, are also discussed.
The Regulatory Networks That Control Clostridium difficile Toxin Synthesis
Authors: Martin-Verstraete Isabelle , Peltier Johann , Dupuy Bruno
Published: May 2016

The pathogenic clostridia cause many human and animal diseases, which typically arise as a consequence of the production of potent exotoxins. Among the enterotoxic clostridia, Clostridium difficile is the main causative agent of nosocomial intestinal infections in adults with a compromised gut microbiota caused by antibiotic treatment. The symptoms of C. difficile infection are essentially caused by the production of two exotoxins: TcdA and TcdB. Moreover, for severe forms of disease, the spectrum of diseases caused by C. difficile has also been correlated to the levels of toxins that are produced during host infection. This observation strengthened the idea that the regulation of toxin synthesis is an important part of C. difficile pathogenesis. This review summarizes our current knowledge about the regulators and sigma factors that have been reported to control toxin gene expression in response to several environmental signals and stresses, including the availability of certain carbon sources and amino acids, or to signaling molecules, such as the autoinducing peptides of quorum sensing systems. The overlapping regulation of key metabolic pathways and toxin synthesis strongly suggests that toxin production is a complex response that is triggered by bacteria in response to particular states of nutrient availability during infection.
Isolation of human salivary extracellular vesicles by iodixanol density gradient ultracentrifugation and their characterizations
Authors: Iwai Kazuya , Minamisawa Tamiko , Suga Kanako , Yajima Yasutomo , Shiba Kiyotaka
Published: May 2016

Diagnostic methods that focus on the extracellular vesicles (EVs) present in saliva have been attracting great attention because of their non‐invasiveness. EVs contain biomolecules such as proteins, messenger RNA (mRNA) and microRNA (miRNA), which originate from cells that release EVs, making them an ideal source for liquid biopsy. Although there have been many reports on density‐based fractionation of EVs from blood and urine, the number of reports on EVs from saliva has been limited, most probably because of the difficulties in separating EVs from viscous saliva using density gradient centrifugation. This article establishes a protocol for the isolation of EVs from human saliva using density gradient centrifugation. The fractionated salivary EVs were characterized by atomic force microscopy, western blot and reverse transcription polymerase chain reaction. The results indicate that salivary EVs have a smaller diameter (47.8±12.3 nm) and higher density (1.11 g/ml) than EVs isolated from conditioned cell media (74.0±23.5 nm and 1.06 g/ml, respectively). Additionally, to improve the throughput of density‐based fractionation of EVs, the original protocol was further modified by using a fixed angle rotor instead of a swinging rotor. It was also confirmed that several miRNAs were expressed strongly in the EV‐marker‐expressing fractions.
Les limites de la cité des Atrébates (nouvelle approche d'un vieux problème)
Authors: Delmaire Bernard , Delmaire Roland
Published: May 2016

Les historiens ont accepté jusqu'ici comme une évidence que les limites de la cité des Atrebates se sont perpétuées dans celles de l'ancien diocèse d' Arras. Cet article démontre la justesse de cette vue par les arguments traditionnels et surtout par le recours aux sources médiévales. Il corrige aussi des vues erronées sur l'extension de la cité au contact des Ménapiens au nord-est et des Nerviens au sud-est. Une annexe recense les lieux que les sources du Ve au XIIe siècle placent dans un des pagi de l'ancienne cité.
Repères pour l'histoire du nationalisme dans les communautés algériennes du Nord et du Pas-de-Calais.
Authors: Genty Jean-René
Published: May 2016

Depuis 1910, des migrants originaires d'Algérie viennent travailler dans les mines et les industries chimiques de la région. Fuyant un pays en crise, ils restèrent pour des séjours de plus en plus longs. Ce fut dans ce milieu de l'immigration que se construisit l'idée nationaliste moderne autour d'un homme, Messali Hadj.

A partir de 1949, les communautés algériennes immigrées adhérèrent massivement à l'organisation nationaliste. Confronté extérieurement à une répression accrue, le mouvement traversa une crise profonde. Le soulèvement du 1er novembre 1954 recueillit son adhésion. Mais les tensions se transformèrent en une effroyable guerre civile qui opposa les deux mouvements nationalistes. Jusqu'en 1962, les partisans de Messali Hadj réussirent à se maintenir dans le Nord. Cette particularité caractérisa bien après 1962 l'immigration algérienne dans notre région.
Les Harkis chaouïas, des Aurès au bassin de la Sambre (1954-1996).
Authors: Boulhaïs Nordine
Published: May 2016

Les Harkis sont des Algériens qui ont combattu aux côtés de la France durant la guerre d'Algérie. La région de Maubeuge en compte une communauté originaire du massif berbère des Aurès, théâtre de l'insurrection en 1954 et de la création des premières unités résultant de la mise à profit par l'administration coloniale d'une rivalité entre tribus. Au cessez-le-feu en 1962, l'irréalisme sur le terrain des solutions qui leur étaient proposées et l'abandon les a exposés aux représailles du FLN. Cependant, beaucoup ont pu être rapatriés dans les camps du Midi. La perspective d'embauché à Usinor les a amenés dans le bassin de la Sambre où ils se sont installés dans un ensemble Sonacotra. Aujourd'hui, ils connaissent des difficultés (chômage, drogue, racisme) mais également une intégration réussie, une association dynamique et des liens communautaires garants de leur culture.
Le « marché augmenté » de l’énergie, des transports et du numérique
Authors: Bainée Jonathan , Le Goff Richard
Published: May 2016

Cet article s’intéresse à la dynamique contemporaine de décloisonnement entre les industries de l’énergie, des transports et du « numérique », auparavant organisées en silos. En cela, il s’inscrit dans le prolongement des travaux portant sur les objets connectés, l’Internet des objets et les « big data », mais s’en distingue en proposant une interprétation originale en termes de « stratégie de marché augmenté ». Elle se saisit comme une stratégie visant à étendre les frontières d’un marché, grâce à la mise en réseau d’industries mobilisant concomitamment un même soubassement immatériel (connaissances, informations…) ou physique (infrastructure, technologie…), à différents niveaux de la chaîne de la valeur. L’ambition de cet article est double. Il s’agit, d’une part, de contribuer à l’analyse exploratoire de telles stratégies, de les caractériser, d’en identifier les déterminants et d’en illustrer les expressions contemporaines. Il s’agit, d’autre part, d’évaluer la portée théorique de nos concepts et de les positionner dans le champ de la convergence industrielle. Codes JEL : L11, L16, L22, L25, L62, L90
Les inventeurs prolifiques comme déterminants des performances technologiques des firmes
Authors: Le Bas Christian
Published: May 2016

L’analyse menée dans cet article prend appui sur la récente littérature soulignant l’importance des inventeurs très productifs pour expliquer les performances technologiques des firmes. Notre contribution est triple : on étudie la performance technologique des firmes dans son champ technologique dominant, nous travaillons sur des firmes de tous les secteurs, on utilise l’indicateur des avantages technologiques révélés comme proxy pour les performances technologiques des firmes. Les données sont issues de la base de brevets du NBER. Les estimations faites confirment que les inventeurs prolifiques et les inventeurs hautement prolifiques (les stars) contribuent aux performances technologiques des firmes. Nos résultats indiquent que les stars contribuent plus que les inventeurs simplement prolifiques. Codes JEL : D22, O31, O32
L’émergence d’une stratégie d’innovation pérenne en très petite entreprise (TPE) : retour sur expérience d’une petite cave coopérative vinicole
Authors: Ceccaldi Valérie
Published: May 2016

L’examen minutieux de l’élaboration d’une stratégie, en TPE, permet de concevoir le principe d’« innovation ». En effet, son fonctionnement, centralisé, oblige à tenir compte des pensées, des visions et du rôle de l’entrepreneur dans chacune des phases de cette construction. L’environnement instable dans lequel vivent les entreprises depuis plus de trois décennies, demande une grande souplesse managériale. Ainsi, alors même que le cheminement stratégique semble suivre un plan défini en amont, sa réalisation surprend par l’importance donnée aux initiatives et aux actes d’apprentissage. Dans ces conditions, peut-on envisager que l’innovation soit pérenne ? La réponse à cette question dépendra du projet imaginé par le dirigeant et de sa motivation à dynamiser le cadre vertueux de sa réalisation. Codes JEL : M190
Le crowdsourcing au service de la collecte d’informations marketing : le cas Clic and Walk
Authors: Renault Sophie
Published: May 2016

Le déploiement des Technologies de l’Innovation et de la Communication (TIC) permet aux organisations d’avoir recours à un fournisseur singulier : la foule. Il est alors question de crowdsourcing pour qualifier cette forme d’externalisation. En matière de crowdsourcing tous les individus parmi la foule sont susceptibles d’apporter leurs ressources et compétences afin de générer de la valeur pour une organisation. Tandis que la contribution de la foule s’exerce dans de nombreux registres, notre recherche s’intéresse plus spécifiquement à la mobilisation de la foule dans un processus de collecte d’informations marketing. Dans une perspective qualitative, fondée sur l’étude de cas Clic and Walk, nous analysons les caractéristiques et les enjeux associés à cette modalité de crowdsourcing . Codes JEL : O32
Les circuits courts alimentaires « pour tous », outils d’analyse de l’innovation sociale
Authors: Chiffoleau Yuna , Paturel Dominique
Published: May 2016

Le renouveau des circuits courts alimentaires en France croise la problématique de l’innovation sociale à travers l’émergence d’initiatives visant à faciliter l’accès des consommateurs précaires à une alimentation de qualité. Cet article montre l’intérêt d’analyser ces initiatives pour comprendre les mécanismes de construction de l’innovation sociale et explorer les conditions de son changement d’échelle. L’approche repose sur un croisement entre sociologie économique et approche par le care , permettant d’intégrer les personnes et le contexte socio-politique dans l’analyse des dynamiques relationnelles qui construisent l’innovation. Basés sur deux études de cas, les résultats montrent en quoi l’innovation sociale se développe à travers de nouveaux types de liens et de ressources valorisant l’expérience de la vie quotidienne. Ils invitent à penser que sa portée transformatrice tient à la fois aux produits découplés de ces liens et à l’évolution des statuts des personnes. L’article appelle à approfondir l’analyse de l’innovation sociale à travers les circuits courts et inversement. Codes JEL : O35, Q13, Q18, A13
Implementation of a Dual Mesh Method for Longitudinal Rolling in QForm V8
Authors: Gerasimov Dmitry , Biba Nikolay , Stebunov Sergei , Kadach Maksim
Published: May 2016

Numerical modeling of longitudinal rolling usually requires high computational power meanwhile it still takes long time to simulate multi pass process. Different methods for increasing of accuracy and speed of rolling simulation have being proposed recently. One of them is simultaneous use of two finite element meshes of different density, i.e. dual mesh method. The article is dedicated to solving of important problems of rolling technology and presents several examples of rolling simulation in QForm V8 based on dual mesh method.
Hybrid Modeling of Materials Properties for Improved CAE-Simulations
Authors: Diekmann Uwe , Miron Alex , Trasca Andreea
Published: May 2016

The new MatPlus software supports the multi-dimensional modelling of materials properties using different data sources. Extensive mathematical functions allow curve fitting of data from different sources to any constitutive models and selectively combining models and datapoints along different dimensions. Physically consistent extrapolation of measured data within the complete multi-dimensional parametric space can be achieved. An integrated library of models can be extended by the user and already contains many popular equations like Hensel-Spittel and Zerilli-Armstrong for flow curves.
Comparison of Numerical Simulation and Experiment for the Microstructure Development of a Cold-Rolled Multiphase Steel during Annealing
Authors: Kwiaton Norbert , Kuziak Roman , Pietrzyk Maciej
Published: May 2016

JAMK model, developed as part of RFSR-project “VADPsheets”, was applied to analyse different time temperature cycles from industrial time temperature cycle. The results of numerical simulation are compared with experimentally determined mechanical properties and microstructures. By distinguishing of recrystallized ferrite, ferrite after transformation, tempered martensite, bainite and martensite can be explained the experimentally obtained mechanical properties. The results of simulation can be used to optimizing the properties and to generate a better understanding of process parameters.
Power Cooling
Authors: Opitz Erich , Seilinger Alois , Pichler Lukas , Silbermann Olaf , Rimnac Axel
Published: May 2016

During the last years international steel producers have been following a market trend to develop and produce new steel grades with higher strength and larger thickness. When attempting to improve the metallurgical properties in the cooling section, the existing cooling equipment in hot strip mills often reaches its limit. Primetals Technologies offers its Power Cooling solution to upgrade existing cooling lines as well as for new hot strip mills. With this type of equipment highest cooling rates can be achieved and therefore steel producers are capable of producing new steel grades with higher strength at lower costs. A new power cooling system was installed immediately behind the finishing mill gauge house at Wuhan Iron and Steel Company’s (WISCO) HSM No. 2 in Wuhan, China. The Power Cooling system widens the product range and gives WISCO the capability to produce high-strength steel grades (AHSS) with strength levels of more than 1,000 MPa, e.g. HSLA steel or as-hot-rolled multi-phase steel. Due to the extremely wide control range of the flow rate, the installation allows for maximum metallurgical flexibility. On the other hand, the new equipment allows for the most economic production of line-pipe material like API X80 in a thickness range up to 25.4 mm (1 inch).
Effect of Parameters in the Physical Simulated Rough Rolling Stage on Microstructure Evaluation and Tensile Properties of a Bainitic Pipeline Steel
Authors: Soliman Mohamed , Palkowski Heinz
Published: May 2016

Microstructure evolution and tensile properties were studied in a bainitic pipeline steel grade by performing a number of physical simulations on samples machined out of an industrially produced transfer bar. In these simulations, the cooling interval between roughing and finishing stages (tV) was varied from 5 s to 180 s. The austenite status after this cooling interval, regarding the prior austenite grain size and precipitates, simulates the condition of austenite before entering the finishing mill. The finishing parameters and the subsequent cooling strategy were kept unchanged throughout all the applied simulation processes. The gradual increase in tV resulted in a gradual increase of the granular bainite phase on the expense of the aciculare ferrite. This resulted in an incremental decrease in ultimate tensile strength and yield strength with increasing tV. However, this behavior approached a steady state condition after which the tV has limited/insignificant effect on the ultimate-and yield strength. This saturating value of tV is process parameter dependent.
The Effect of Sheet Thickness, Loading Rate and Punch Diameter on the Deformation Behaviour of AZ31 during 3-Point Bending
Authors: Berge Franz , Winderlich Heiko , Krbetschek Christina , Ullmann Madlen , Kawalla Rudolf
Published: May 2016

In this study, the influence of sheet thickness, loading rate, and punch diameter on the bending behaviour of twin-roll cast, rolled and heat-treated AZ31 magnesium alloy was investigated. Therefore, the 3-point bending test was performed at room temperature using an electromechanical testing machine (v = 0.1−10 mm/s) with different punch diameters (D = 2 mm, 8 mm, 16 mm). The initial material has a recrystallized microstructure with grain sizes of 6−9 µm. It is shown by the mechanical investigations that the bending force increases with the sheet thickness. In contrast to this, the bending angle is independent of the sheet thickness. In addition, the punch diameter and the loading rate do not influence the maximum force and the bending angle significantly.
Synthesis of Few-Layer Graphene on Copper Using a Low-Cost Atmospheric Thermal Chemical Vapour Deposition System with Methane and Forming Gas
Authors: Shamsudin M.S. , Fishlock S.J. , Rusop M. , Sanip S.M. , Pu Suan Hui
Published: May 2016

Graphene has attracted wide interest across a range of applications due to its electrical, mechanical and optical properties. The use of a low-cost, table-top chemical vapour deposition system to deposit few-layer graphene onto copper is reported in this work. Characterisation of the graphene is performed using Raman spectroscopy and atomic force microscopy. The results show that few-layer graphene can be deposited at 1000 °C using CH4 as a carbon precursor, and 5% H2, 95% N2 forming gas as a diluent. The effects of deposition temperature, deposition time, and forming gas addition on graphene film quality was studied experimentally. An increase in graphene quality was observed when forming gas was added during deposition.
Coevolution of RAC Small GTPases and their Regulators GEF Proteins
Authors: Jiménez-Sánchez Alejandro
Published: May 2016

RAC proteins are small GTPases involved in important cellular processes in eukaryotes, and their deregulation may contribute to cancer. Activation of RAC proteins is regulated by DOCK and DBL protein families of guanine nucleotide exchange factors (GEFs). Although DOCK and DBL proteins act as GEFs on RAC proteins, DOCK and DBL family members are evolutionarily unrelated. To understand how DBL and DOCK families perform the same function on RAC proteins despite their unrelated primary structure, phylogenetic analyses of the RAC, DBL, and DOCK families were implemented, and interaction patterns that may suggest a coevolutionary process were searched. Interestingly, while RAC and DOCK proteins are very well conserved in humans and among eukaryotes, DBL proteins are highly divergent. Moreover, correlation analyses of the phylogenetic distances of RAC and GEF proteins and covariation analyses between residues in the interacting domains showed significant coevolution rates for both RAC–DOCK and RAC–DBL interactions.
Back to the Future: What Learning Communities Offer to Medical Education
Authors: Osterberg Lars G. , Goldstein Erika , Hatem David S. , Moynahan Kevin , Shochet Robert
Published: May 2016

Learning communities (LCs) have increasingly been incorporated into undergraduate medical education at a number of medical schools in the United States over the past decade. In an Association of Medical Colleges survey of 140 medical schools, 102 schools indicated that they had LC (described as colleges or mentorship groups; https://www.aamc.org/initiatives/cir/425510/19a.html ). LCs share an overarching principle of establishing longitudinal relationships with students and faculty, but differ in the emphasis on specific components that may include curriculum delivery, advising/ mentoring, student wellness, and community. The creation of LCs requires institutional commitment to reorganize educational processes to become more student centered. LCs are beginning to show positive outcomes for students including benefits related to clinical skills development, advising, and student wellness, in addition to positive outcomes for LC faculty.
Chebyshev-Legendre Spectral Domain Decomposition Method for Two-Dimensional Vorticity Equations
Authors: Wu Hua , Pan Jiajia , Zheng Haichuan
Published: May 2016

We extend the Chebyshev-Legendre spectral method to multi-domain case for solving the two-dimensional vorticity equations. The schemes are formulated in Legendre-Galerkin method while the nonlinear term is collocated at Chebyshev-Gauss collocation points. We introduce proper basis functions in order that the matrix of algebraic system is sparse. The algorithm can be implemented efficiently and in parallel way. The numerical analysis results in the case of one-dimensional multi-domain are generalized to two-dimensional case. The stability and convergence of the method are proved. Numerical results are given.
3D Simulations of Blood Flow Dynamics in Compliant Vessels: Normal, Aneurysmal, and Stenotic Arteries
Authors: Kim Yongsam , Park Yunyoung , Lim Sookkyung
Published: May 2016

Arterial diseases such as aneurysm and stenosis may result from the mechanical and/or morphological change of an arterial wall structure and correspondingly altered hemodynamics. The development of a 3D computational model of blood flow can be useful to study the hemodynamics in major blood vessels and may provide an insight into the noninvasive technique to detect arterial diseases in early stage. In this paper, we present a three-dimensional model of blood flow in the aorta, which is based on the immersed boundary method to describe the interaction of blood flow with the aortic wall. Our simulation results show that the hysteresis loop is evident in the pressure-diameter relationship of the normal aorta when the arterial wall is considered to be viscoelastic. In addition, it is shown that flow patterns and pressure distributions are altered in response to the change of aortic morphology.
Solving Maxwell's Equation in Meta-Materials by a CG-DG Method
Authors: Xie Ziqing , Wang Jiangxing , Wang Bo , Chen Chuanmiao
Published: May 2016

In this paper, an approach combining the DG method in space with CG method in time (CG-DG method) is developed to solve time-dependent Maxwell's equations when meta-materials are involved. Both the unconditional L2-stability and error estimate of order are obtained when polynomials of degree at most r is used for the temporal discretization and at most k for the spatial discretization. Numerical results in 3D are given to validate the theoretical results.
Computational Study of Traveling Wave Solutions of Isothermal Chemical Systems
Authors: Qi Yuanwei , Zhu Yi
Published: May 2016

This article studies propagating traveling waves in a class of reaction-diffusion systems which model isothermal autocatalytic chemical reactions as well as microbial growth and competition in a flow reactor. In the context of isothermal autocatalytic systems, two different cases will be studied. The first is autocatalytic chemical reaction of order m without decay. The second is chemical reaction of order m with a decay of order n, where m and n are positive integers and m>n≥1. A typical system in autocatalysis is A+2B→3B and B→C involving two chemical species, a reactant A and an auto-catalyst B and C an inert chemical species.

The numerical computation gives more accurate estimates on minimum speed of traveling waves for autocatalytic reaction without decay, providing useful insight in the study of stability of traveling waves.

For autocatalytic reaction of order m = 2 with linear decay n = 1, which has a particular important role in chemical waves, it is shown numerically that there exist multiple traveling waves with 1, 2 and 3 peaks with certain choices of parameters.
Two-Grid Method for Miscible Displacement Problem by Mixed Finite Element Methods and Mixed Finite Element Method of Characteristics
Authors: Chen Yanping , Hu Hanzhang
Published: May 2016

The miscible displacement of one incompressible fluid by another in a porous medium is governed by a system of two equations. One is elliptic form equation for the pressure and the other is parabolic form equation for the concentration of one of the fluids. Since only the velocity and not the pressure appears explicitly in the concentration equation, we use a mixed finite element method for the approximation of the pressure equation and mixed finite element method with characteristics for the concentration equation. To linearize the mixed-method equations, we use a two-grid algorithm based on the Newton iteration method for this full discrete scheme problems. First, we solve the original nonlinear equations on the coarse grid, then, we solve the linearized problem on the fine grid used Newton iteration once. It is shown that the coarse grid can be much coarser than the fine grid and achieve asymptotically optimal approximation as long as the mesh sizes satisfy h = H2 in this paper. Finally, numerical experiment indicates that two-grid algorithm is very effective.
Nanoparticle-Based Histidine-Rich Protein-2 Assay for the Detection of the Malaria Parasite Plasmodium falciparum
Authors: Castro-Sesquen Yagahira E. , Kim Chloe , Gilman Robert H. , Sullivan David J. , Searson Peter C.
Published: May 2016

A nanoparticle-based assay for detection and quantification of Plasmodium falciparum histidine-rich protein 2 (HRP2) in urine and serum is reported. The assay uses magnetic beads conjugated with anti-HRP2 antibody for protein capture and concentration, and antibody-conjugated quantum dots for optical detection. Western blot analysis demonstrated that magnetic beads allow the concentration of HRP2 protein in urine by 20-fold. The concentration effect was achieved because large volume of urine can be incubated with beads, and magnetic separation can be easily performed in minutes to isolate beads containing HRP2 protein. Magnetic beads and quantum dots conjugated to anti-HRP2 antibodies allows the detection of low concentrations of HRP2 protein (0.5 ng/mL), and quantification in the range of 33–2,000 ng/mL corresponding to the range associated with non-severe to severe malaria. This assay can be easily adapted to a noninvasive point-of-care test for classification of severe malaria.
Oxygenation of the Newborn
Authors: Saugstad Ola D
Published: May 2016

Newborn infants in need of positive pressure ventilation at birth should initially be given 21% O2from term to gestational age 33 weeks. Gestational ages 29-32 weeks could be given initially FiO2of 0.21-0.30. For ≤ 28 weeks FiO2of 0.30 or more should be given initially. FiO2should then be adjusted according to the oxygen saturation response assessed by pulse oximetry.

After delivery room stabilisation oxygen saturation targets of 85-89% increases the risk of mortality and necrotizing enterocolitis. In spite an oxygen target of 90-95% increases the risk of ROP this is presently the recommended range.

How to cite this article

Saugstad OD. Oxygenation of the Newborn. Donald School J Ultrasound Obstet Gynecol 2016;10(2):170-171.
Cell-free DNA Testing: Where are We now?
Authors: Goynumer Gokhan , Sen Cihat , Api Olus , Yayla Murat
Published: May 2016

Prenatal screening for fetal aneuploidies has been focused on mainly Down syndrome in the last 40 years. The method of screening has changed from maternal age in the 1970s, with a detection rate of 30 and 5% false positive rate (FPR), to a combination of maternal age and second-trimester serum biochemical markers (triple test and quadruple test) in the 1980s and 1990s, with 60 to 75% detection rate and 5% false positive rate (FPR). Following this, the era of first trimester screening for Down syndrome has started with the clinical implementation of fetal nuchal translucency screening. The combination of maternal age, NT thickness and serum free beta-human chorionic gonadotropin (â-hCG) and pregnancy-associated plasma protein A (PAPP-A) in the first trimester has yielded a 90% detection rate with a 5% FPR. Starting from the year 2008, studies have shown that the performance of screening may be improved by analysis of cell-free deoxyribonucleic acid (DNA) (cfDNA) in maternal blood. Several studies in the last few years have reported the clinical validation of cell free fetal DNA test in the maternal serum in screening for trisomies 21, 18, and 13 and sex chromosome aneuploidies.

Its widespread use is limited by the relatively high cost of the test and the lack of consensus about the optimal way for its clinical implementation. Until the optimal way of incorporating cfDNA into the clinical practice gets identified, it would be wise not to substitute cfDNA testing in place of first-trimester screening for fetal defects and other major complications of pregnancy. Furthermore, it would be preferable for clinicians managing individual patients not to counsel them for their result as positive or negative, rather the clinicians should use the risk estimate from the first-line method of screening as the prior risk and modify this by the appropriate positive or negative likelihood ratio from the cfDNA test.

How to cite this article

Sen C, Api O, Yayla M, Goynumer G. Cell-free DNA Testing: Where are We now? Donald School J Ultrasound Obstet Gynecol 2016;10(2):172-177.
Potential of polarization lidar to provide profiles of CCN- and INP-relevant aerosol parameters
Authors: Mamouri Rodanthi-Elisavet , Ansmann Albert
Published: May 2016

Abstract. We investigate the potential of polarization lidar to provide vertical profiles of aerosol parameters from which cloud condensation nucleus (CCN) and ice nucleating particle (INP) number concentrations can be estimated. We show that height profiles of particle number concentrations n50, dry considering dry aerosol particles with radius  > 50 nm (reservoir of CCN in the case of marine and continental non-desert aerosols), n100, dry (particles with dry radius  >  100 nm, reservoir of desert dust CCN), and of n250, dry (particles with dry radius  >  250 nm, reservoir of favorable INP), as well as profiles of the particle surface area concentration sdry (used in INP parameterizations) can be retrieved from lidar-derived aerosol extinction coefficients σ with relative uncertainties of a factor of 1.5–2 in the case of n50, dry and n100, dry and of about 25–50 % in the case of n250, dry and sdry. Of key importance is the potential of polarization lidar to distinguish and separate the optical properties of desert aerosols from non-desert aerosol such as continental and marine particles. We investigate the relationship between σ, measured at ambient atmospheric conditions, and n50, dry for marine and continental aerosols, n100, dry for desert dust particles, and n250, dry and sdry for three aerosol types (desert, non-desert continental, marine) and for the main lidar wavelengths of 355, 532, and 1064 nm. Our study is based on multiyear Aerosol Robotic Network (AERONET) photometer observations of aerosol optical thickness and column-integrated particle size distribution at Leipzig, Germany, and Limassol, Cyprus, which cover all realistic aerosol mixtures. We further include AERONET data from field campaigns in Morocco, Cabo Verde, and Barbados, which provide pure dust and pure marine aerosol scenarios. By means of a simple CCN parameterization (with n50, dry or n100, dry as input) and available INP parameterization schemes (with n250, dry and sdry as input) we finally compute profiles of the CCN-relevant particle number concentration nCCN and the INP number concentration nINP. We apply the method to a lidar observation of a heavy dust outbreak crossing Cyprus and a case dominated by continental aerosol pollution.
Effects of aerosols on clear-sky solar radiation in the ALADIN-HIRLAM NWP system
Authors: Gleeson Emily , Toll Velle , Nielsen Kristian Pagh , Rontu Laura , Mašek Ján
Published: May 2016

Abstract. The direct shortwave radiative effect of aerosols under clear-sky conditions in the Aire Limitee Adaptation dynamique Developpement InterNational – High Resolution Limited Area Model (ALADIN-HIRLAM) numerical weather prediction system was investigated using three shortwave radiation schemes in diagnostic single-column experiments: the Integrated Forecast System (IFS), acraneb2 and the hlradia radiation schemes. The multi-band IFS scheme was formerly used operationally by the European Centre for Medium Range Weather Forecasts (ECMWF) whereas hlradia and acraneb2 are broadband schemes. The former is a new version of the HIRLAM radiation scheme while acraneb2 is the radiation scheme in the ALARO-1 physics package. The aim was to evaluate the strengths and weaknesses of the numerical weather prediction (NWP) system regarding aerosols and to prepare it for use of real-time aerosol information. The experiments were run with particular focus on the August 2010 Russian wildfire case. Each of the three radiation schemes accurately (within ±4 % at midday) simulates the direct shortwave aerosol effect when observed aerosol optical properties are used. When the aerosols were excluded from the simulations, errors of more than +15 % in global shortwave irradiance were found at midday, with the error reduced to +10 % when standard climatological aerosols were used. An error of −11 % was seen at midday if only observed aerosol optical depths at 550 nm, and not observation-based spectral dependence of aerosol optical depth, single scattering albedos and asymmetry factors, were included in the simulations. This demonstrates the importance of using the correct aerosol optical properties. The dependency of the direct radiative effect of aerosols on relative humidity was tested and shown to be within ±6 % in this case. By modifying the assumptions about the shape of the IFS climatological vertical aerosol profile, the inherent uncertainties associated with assuming fixed vertical profiles were investigated. The shortwave heating rates in the boundary layer changed by up to a factor of 2 in response to the aerosol vertical distribution without changing the total aerosol optical depth. Finally, we tested the radiative transfer approximations used in the three radiation schemes for typical aerosol optical properties compared to the accurate DISORT model. These approximations are found to be accurate to within ±13 % even for large aerosol loads.
Clustering, Methodology, and Mechanistic Insights Into Acetate Chemical Ionization Using High-Resolution Time-of-Flight Mass Spectrometry
Authors: Brophy Patrick , Farmer Delphine K.
Published: May 2016

Abstract. We present a comprehensive characterization of cluster control and transmission through the Tofwerk atmospheric pressure interface installed on various chemical ionization time-of-flight mass spectrometers using authentic standards. This characterization of the atmospheric pressure interface allows for a detailed investigation of the acetate chemical ionization mechanisms and the impact of controlling these mechanisms on sensitivity, selectivity, and mass spectral ambiguity with the aim of non-targeted analysis. Chemical ionization with acetate reagent ions is controlled by a distribution of reagent ion-neutral clusters that vary with relative humidity and the concentration of acetic anhydride precursor. We show that the majority, if not all, ion-neutral chemistry occurs in the ion molecule reactor where incoming sample air mixes with the output of the ion source. Deprotonated carboxylic acids are primarily detected only if sufficient declustering is employed inside the atmospheric pressure interface. The configuration of a high-resolution time-of-flight chemical ionization mass spectrometer (HR-TOF-CIMS) using an acetate chemical ionization source for non-targeted analysis is discussed. Recent approaches and studies characterizing acetate chemical ionization as it applies to the HR-TOF-CIMS are evaluated in light of the work presented herein.
Response of soil respiration to nitrogen addition along a degradation gradient in a temperate steppe of northern China
Authors: Chen Jinbin , Xu Xiaotian , Liu Hongyan , Wang Wei
Published: May 2016

Abstract. Although numerous studies have been conducted on the responses of soil respiration (Rs) to nitrogen (N) addition in grassland ecosystems, it remains unclear whether a nonlinear relationship between Rs and N addition exists and whether there is a uniform response across grasslands with different degradation status. We established a field experiment with six N treatments (0, 10, 20, 30, 40, and 50 g N m−2 y−1) on four grassland sites, each with a varied degradation states in the Inner Mongolia steppe of northern China during the growing seasons of 2012 and 2013. Rs and its major influential factors, including aboveground biomass, root biomass, plant tissues carbon (C) and N concentrations, soil organic carbon (SOC) and soil total nitrogen (STN), microbial biomass and soil pH, were measured. Results show that N fertilization did not change the seasonal patterns of Rs but it changed the magnitude of Rs in grasslands with a different degradation status and only degradation had signification effects on Rs. This shows that variations of Rs in degraded grasslands were due to the difference in SOC content. The response of Rs to N addition differed with the severity of degradation. Furthermore, the response of Rs to N addition slowed down over time. The dominant factor controlling Rs changed across different degradation grasslands. The leading factors for Rs were SOC and STN in non-degraded and moderately degraded grassland; soil pH in severely degraded grassland; and aboveground biomass and root biomass in extremely degraded grassland. Our results highlight the importance of considering the degradation level of grassland to identify soil carbon emissions in grassland ecosystems, and N addition may alter the difference of soil carbon emissions in different degraded grasslands and change its soil carbon emissions pattern.
Identification of anthropogenic and natural inputs of sulfate into a karstic coastal groundwater system in northeast China: evidence from major ions, δ13CDIC and δ34SSO4
Authors: Han Dongmei , Song Xianfang , Currell Matthew J.
Published: May 2016

Abstract. The hydrogeochemical processes controlling groundwater evolution in the
Daweijia area of Dalian, northeast China, were characterised using
hydrochemistry and isotopes of carbon and sulfur (δ13CDIC and δ34SSO4). The aim was to distinguish anthropogenic impacts as distinct from natural processes, with a particular focus on sulfate, which is found at elevated levels (range: 54.4 to 368.8 mg L−1; mean: 174.4 mg L−1) in fresh and brackish groundwater. The current investigation reveals minor seawater intrusion
impact (not exceeding 5 % of the overall solute load), in contrast with
extensive impacts observed in 1982 during the height of intensive
abstraction. This indicates that measures to restrict groundwater abstraction
have been effective. However, hydrochemical facies analysis shows that the
groundwater remains in a state of ongoing hydrochemical evolution (towards
Ca–Cl type water) and quality degradation (increasing nitrate and
sulfate concentrations). The wide range of
NO3 concentrations (74.7–579 mg L−1) in the Quaternary aquifer indicates considerable input of fertilisers and/or leakage from septic
systems. Both δ13C (−14.5 to −5.9 ‰) and
δ34SSO4 (+5.4 to +13.1 ‰) values in groundwater show increasing trends along groundwater flow paths. While carbonate minerals may contribute to increasing δ13CDIC and δ34SSO4 values in deep karstic groundwater, high
loads of agricultural fertilisers reaching the aquifer via irrigation return
flow are likely the main source of the dissolved sulfate in Quaternary
groundwater, as shown by distinctive isotopic ratios and a lack of evidence
for other sources in the major ion chemistry. According to isotope mass
balance calculations, the fertiliser contribution to overall sulfate has
reached an average of 62.1 % in the Quaternary aquifer, which has a strong
hydraulic connection to the underlying carbonate aquifer. The results point
to an alarming level of impact from the local intensive agriculture on the
groundwater system, a widespread problem throughout China.