bluuebunny/crossref_metadata_2025 huggingface dataset:
Структура вузовской сети: от советского к российскому «мастер-плану»
Authors: Kuzminov Yaroslav , Semyonov Dmitry , Froumin Isak
Published: July 2015

Кузьминов Ярослав Иванович - кандидат экономических наук, ректор Национального исследовательского университета «Высшая школа эконо-мики», научный руководитель Института институциональных исследований.  E-mail: kouzminov@hse.ruСеменов Дмитрий Сергеевич - заведующий проектно-учебной лабораторией «Развитие университетов» Национального исследовательского университета «Высшая школа экономики». E-mail: dsemyonov@hse.ruФрумин Исак Давидович - доктор педагогических наук, научный руководитель Института образования Национального исследовательскогоуниверситета «Высшая школа эконо-мики».  E-mail: ifroumin@hse.ruОбсуждаются основания структурного анализа в системе высшего образования. Обосновывается использование ориентации на специфические сегменты рынка труда и характера основного продукта университета в качестве оснований типологии и выделения групп организаций. На основе сформулированного подхода к типологии реконструируется советский «мастер-план», поскольку, с точки зрения авторов, сегодняшняя структура российской системы высшего образования во многом определяется советским опытом ее развития. Показано, что советский проект был построен на идее административного регулирования рынка труда и в целом реализовывал модель квазикорпоративной системы высшего профессионального образования. Анализируются изменения, произошедшие в структуре системы высшего образования, доставшейся России от СССР, под влиянием внешних для системы образования факторов и весьма в малой степени — за счет сознательной государственной политики. На основании анализа количественных данных описывается типология организаций высшего образования, возникшая в результате этих изменений. Рассматриваются возможные направления структурной политики в сфере высшего профессионального образования как основы для создания «мастер-плана» реструктуризации системы высшего образования в России. Сформулированы цели, которым должна отвечать модернизация структуры высшего образования.
Исследование социальных сетей в высшем образовании (пер.с англ. Н. Микшиной)
Authors: Biancani Susan , McFarland Daniel
Published: July 2015

Бьянкани Сьюзан - научный сотрудник Педагогической школы Стэнфордского университета. E-mail: biancani@standford.eduАдрес: School of Education, Stanford Universit y, 485 Lasuen Mall, Stanford, C A94305, USA.Макфарланд Дэниел А. - научный сотрудник Педагогической школы Стэнфордского университета. E-mail: mcfarland@stanford.eduАдрес: School of Education, Stanford Universit y, 485 Lasuen Mall, Stanford, C A94305, USA.В обзоре литературы, посвященной исследованию социальных сетей в высшем образовании, работы представлены как аналитически, так и эмпирически. Обзор организован следующим образом: описательные работы; исследования, в которых сети выступают зависимой переменной; исследования, в которых сети выступают независимой переменной. Рассматриваются закономерности образования дружеских связей между студентами, влияние расовых и этнических различий на формирование социальных связей в студенческой среде,  воздействие этих связей на академическую успешность учащихся.
Por onde anda a louca da casa?
Authors: Carneiro Flávio
Published: July 2015

Anunciamos um seqüestro e propomos uma investigação detetivesca: por onde anda, ou por onde não anda, a imaginação? Parte-se de uma premissa: desde os seus primórdios, a literatura, para crianças e adultos, tem servido tanto como instrumento de abertura quanto de repressão do imaginário. Das várias formas de fascismo, talvez a mais cruel seja aquela que toma emprestadas as armas de sedução do texto literário para anunciar falsas promessas de liberdade, vetando a imaginação quando parece franqueá-la. Daí a importância, hoje, de se perguntar: não seria o caso de nos dedicarmos às vezes à delicada arte de não ler?
Temperando o conhecimento: narrativas míticas
Authors: Barbosa Tereza Virgínia Ribeiro
Published: July 2015

Retomamos o entendimento de mito desenvolvido por Luciano de Samósata, séc. II d. C., no prolaliá Acerca do âmbar ou Os cisnes. Nesse pequeno exercício retórico, o autor ataca o uso da narrativa mítica no processo educativo, qualificando-a de equivocada e comparando-a com as distorções visuais que um corpo submerso na água aparenta sofrer (refração). Em seguida, conjugamos o texto referido a dois tratados de Plutarco de Queronea, séc. I d. C. (De Liberis e De audientis poetis). Voltamos ao gênero ficcional, na intenção de definir o mito e utilizamos as sugestões de Apuleio, séc. II d. C., em seu romance O asno, acerca da função da narrativa mítica. Concluímos ampliando a aplicação da metáfora estabelecida por Luciano.

We retake the myth agreement developed for Lucian (II d. C), in the prolalia Concerning the amber or The swans. In this small rhetorical exercise, the author attacks the use of mythical narrative in the educative process, by characterizing it as a kind of a mistake and comparing it with the visual distortions that a submerged body seems to suffer (refraction). After that, we conjugate the cited text and two Treatises of Plutarch of Queronea, (I d. C.), De Liberis and De poetis audientis. We come back to the ficcional genre, aiming at define the myth. Therefore, we use the suggestions of Apuleius (II d. C.) in his romance The golden ass, concerning the function of the mythical narrative. We conclude extending the application of the metaphor established by Lucian.
Sintoma e estilo
Authors: Vidigal Cristina
Published: July 2015

A partir do relato de um fragmento da análise uma criança de seis anos, este texto visa associar sintoma e estilo.

A partir du récit d’un fragment de l’analyse d’un enfant âgé de six ans, ce texte cherche à associer symptôme et style.
A criatividade da infância e sua capacidade de lidar com a morte em José Cardoso Pires e Guimarães Rosa
Authors: Duarte Lélia Parreira
Published: July 2015

José Cardoso Pires e Guimarães Rosa são autores que dedicam especial carinho às suas personagens crianças, vistas como sensíveis e muitas vezes vítimas de violências, mas também como criativas e capazes de lidar, com uma outra linguagem, com o sofrimento, o medo e a morte. É o que pretendo mostrar nos contos “Os reis-mandados”, de José Cardoso Pires, e “Pirlimpsiquice”, “A menina de lá” e “Partida do audaz navegante”, de João Guimarães Rosa.

José Cardoso Pires and Guimarães Rosa are deeply involved with their characters as children, sensitive and often the victims of violence, but also creative and able to deal with suffering, fear and death through the use of another language. This paper concerns that aspect of those authors in the short stories ‘Os reis-mandados’, by José Cardoso Pires, and ‘Pirlimpsiquice’, ‘A menina de lá’ and ‘Partida do audaz navegante’, by João Guimarães Rosa.
Cidade, infância e memória em Os rios morrem de sede, de Wander Piroli
Authors: Freitas Marcus Vinicius De
Published: July 2015

Este artigo analisa as relações entre memória e espaço urbano no romance Os rios morrem de sede, de Wander Piroli. A deterioração das condições de vida nas grandes cidades, com a conseqüente perda da identificação entre o homem e o espaço configura um tema central na obra do autor, do qual emerge a força da memória como mecanismo de resgate do passado e construção da identidade.

This article aims at analizing the links among memory and urban space in Wander Piroli’s Os rios morrem de sede. The deterioration of life conditions inside large cities as well as the lack of identificantion between human beings and the surrounding space constitute the central themes of Piroli’s work, from where memory emerges as a strategy of reconciling the past and building a new identity.
Le développement de l'autonomie dans l'apprentissage des langues et cultures étrangères : Le cas de l'Université de Strasbourg
Authors: Poteaux Nicole
Published: July 2015

Dans cet article, nous abordons la question du développement de l’autonomie d’apprentissage, appliquée au domaine des langues étrangères, à l’université, en particulier. En corollaire, les notions d’autoformation et d’auto-évaluation seront discutées en articulation. Nous présenterons ensuite une réflexion sur les dispositifs pédagogiques qui favorisent le développement de l’autonomie de l’apprentissage des langues avec une attention particulière portée aux postures et rôles des enseignants. Un exemple pris dans l’expérience des Centres de Ressources de Langues de l’Université de Strasbourg, menée depuis vingt ans, illustrera le propos. Enfin, nous questionnerons les perspectives d’évolution de l’enseignement /apprentissage des langues dans le contexte socio-politique européen actuel.
Les compétences en français : Agentivité et motivation des étudiants universitaires
Authors: Baranowski Krystyna
Published: July 2015

L’agence de recrutement de l’Université de St-Boniface, petite université francophone de l’Ouest canadien, cherche à recruter des étudiantes et étudiants au sein de ses programmes de 1er cycle auprès des écoles d’immersion française, des écoles françaises ainsi que des collectivités d’immigrants francophones. Cependant, un pourcentage important des étudiants admis éprouve des difficultés relatives aux compétences linguistiques.Les résultats préliminaires de ma recherche qualitative fondée sur une série d’entretiens avec des étudiants allophones, anglophones et francophones révèlent une « responsabilisation linguistique » des apprenants grâce à l’intégration de certains éléments du Portfolio canadien des langues pour enseignants (CASLT/ACPLS, 2010) dans le cadre du cours de rattrapage, Français 1001 : Grammaire de l’écrit. Les répercussions sur l’encadrement linguistique des étudiants, la formation initiale des enseignants de langue et le rôle primordial des écoles secondaires sont mis en valeur dans ce rapport.
Engaging the hidden curriculum within the Canadian Language Benchmarks (2000 and 2012) as a complicated conversation
Authors: Fleming Douglas
Published: July 2015

This article examines the Canadian Language Benchmarks (Pawlikowska-Smith, 2000; Hajer and Kaskens 2012) within the context of national second language programming. I argue that students and teachers can view such documents as hidden curriculum with which they can engage as complicated conversations (Pinar, 2012).
Towards narrative-centred digital texts for advanced second language learners
Authors: Bazinet Nolan
Published: July 2015

Recently, there has been a steady influx of language development software and games intended for use both at home and in the classroom. Although some of these technologies are effective for language learners to develop certain skills such as sight word recognition, many of them lack aspects of advanced level literacy such as expanded narrative and character development, which can allow for higher cognitive function and thus greater language mastery. While recent research emphasizes the pedagogical possibilities for video games and interactive fiction when teaching basic L1 literacy and literature respectively (Simanowski, Schäfer and Gendolla, 2010; Beavis, O’Mara and McNeice, 2012), this paper makes the argument that similar texts and media can help advanced L2 language learners further develop a knowledge of figurative, culturally imbued language which they could analyze and substantiate in relatively autonomous environments. Furthermore, these digital texts function as dynamic, pedagogical tools that can elicit critical technological literacy, a skill that is ever more crucial in our increasingly mediatised and technological age.
Reaping the benefits of using Twitter in advanced language learning
Authors: Johnson Stacia Beverley
Published: July 2015

The need to use and integrate digital literacy tools is critical in the current landscape of advanced language learning. Microblogging (e.g. Twitter) is one such tool that fosters student interaction and collaboration among language learners. This article will conceptualize the practice of tweeting, in relation to social constructivist theory and to new literacies, in senior high school language classes using CEFR’s B1 and B2 proficiency level tasks. The perceived benefits of using Twitter for language learning will be listed. Guides to getting educators started with Twitter, suggestions for tweet tasks and connections for CEFR C1 and C2 advanced language learners will also be included.
Open Problems on Connectivity of Fibers with Positive Margins in Multi-dimensional Contingency Tables
Authors: Yoshida Ruriko
Published: July 2015

Abstract. Diaconis-Sturmfels developed an algorithm for sampling from conditional distributionsfor a statistical model of discrete exponential families, based on the algebraic theory of toricideals. This algorithm is applied to categorical data analysis through the notion of Markov bases.Initiated with its application to Markov chain Monte Carlo approach for testing statistical fittingof the given model, many researchers have extensively studied the structure of Markov bases formodels in computational algebraic statistics. In the Markov chain Monte Carlo approach fortesting statistical fitting of the given model, a Markov basis is a set of moves connecting allcontingency tables satisfying the given margins. Despite the computational advances, there areapplied problems where one may never be able to compute a Markov basis. In general, the numberof elements in a minimal Markov basis for a model can be exponentially many. Thus, it is importantto compute a reduced number of moves which connect all tables instead of computing a Markovbasis. In some cases, such as logistic regression, positive margins are shown to allow a set ofMarkov connecting moves that are much simpler than the full Markov basis. Such a set is calleda Markov subbasis with assumption of positive margins.In this paper we summarize some computations of and open problems on Markov subbases forcontingency tables with assumption of positive margins under specific models as well as developalgebraic methods for studying connectivity of Markov moves with margin positivity to developMarkov sampling methods for exact conditional inference in statistical models where the Markovbasis is hard to compute.
Array Variate Random Variables with Multiway Kro- necker Delta Covariance Matrix Structure
Authors: Akdemir Deniz , Gupta Arjun K.
Published: July 2015

Standard statistical methods applied to matrix random variables often fail to describethe underlying structure in multiway data sets. After a review of the essential background material,this paper introduces the notion of array variate random variable. A normal array variate randomvariable is dened and a method for estimating the parameters of array variate normal distributionis given. We introduce a technique called slicing for estimating the covariance matrix of highdimensional data. Finally, principal component analysis and classication techniques are developedfor array variate observations and high dimensional data.
Detecting epistasis via Markov bases
Authors: Malaspinas Anna-Sapfo , Uhler Caroline
Published: July 2015

Rapid research progress in genotyping techniques have allowed large genome-wide associationstudies. Existing methods often focus on determining associations between single loci anda specic phenotype. However, a particular phenotype is usually the result of complex relationshipsbetween multiple loci and the environment. In this paper, we describe a two-stage methodfor detecting epistasis by combining the traditionally used single-locus search with a search formultiway interactions. Our method is based on an extended version of Fisher's exact test. Toperform this test, a Markov chain is constructed on the space of multidimensional contingencytables using the elements of a Markov basis as moves. We test our method on simulated data andcompare it to a two-stage logistic regression method and to a fully Bayesian method, showing thatwe are able to detect the interacting loci when other methods fail to do so. Finally, we apply ourmethod to a genome-wide data set consisting of 685 dogs and identify epistasis associated withcanine hair length for four pairs of single nucleotide polymorphisms (SNPs).
Geometry of Higher-Order Markov Chains
Authors: Sturmfels Bernd
Published: July 2015

We determine an explicit Grobner basis, consisting of linear forms and determinantalquadrics, for the prime ideal of Raftery's mixture transition distribution model for Markov chains.When the states are binary, the corresponding projective variety is a linear space, the model itselfconsists of two simplices in a cross-polytope, and the likelihood function typically has two localmaxima. In the general non-binary case, the model corresponds to a cone over a Segre variety.
Hilbert Polynomial of the Kimura 3-Parameter Model
Authors: Kubjas Kaie
Published: July 2015

In [2] Buczy´nska and Wi´sniewski showed that the Hilbert polynomial of the algebraicvariety associated to the Jukes-Cantor binary model on a trivalent tree depends only on the numberof leaves of the tree and not on its shape. We ask if this can be generalized to other group-basedmodels. The Jukes-Cantor binary model has Z2 as the underlying group. We consider the Kimura3-parameter model with Z2 × Z2 as the underlying group. We show that the generalization of thestatement about the Hilbert polynomials to the Kimura 3-parameter model is not possible as theHilbert polynomial depends on the shape of a trivalent tree.
Binary hidden Markov models and varieties
Authors: Critch Andrew
Published: July 2015

This paper closely examines HMMs in which all the hidden random variables arebinary. Its main contributions are (1) a birational parametrization for every such HMM, with anexplicit inverse for recovering the hidden parameters in terms of observables, (2) a semialgebraicmodel membership test for every such HMM, and (3) minimal dening equations for the 4-nodefully binary model, comprising 21 quadrics and 29 cubics, which were computed using Grobnerbases in the cumulant coordinates of Sturmfels and Zwiernik. The new model parameters in (1) arerationally identiable in the sense of Sullivant, Garcia-Puente, and Spielvogel, and each model'sZariski closure is therefore a rational projective variety of dimension 5. Grobner basis computationsfor the model and its graph are found to be considerably faster using these parameters. In thecase of two hidden states, item (2) supersedes a previous algorithm of Schonhuth which is onlygenerically dened, and the dening equations (3) yield new invariants for HMMs of all lengths 4. Such invariants have been used successfully in model selection problems in phylogenetics, andone can hope for similar applications in the case of HMMs.
Higher Connectivity of Fiber Graphs of Gröbner Bases
Authors: Potka Samu
Published: July 2015

Fiber graphs of Gröbner bases from contingency tables are important in statisticalhypothesis testing, where one studies random walks on these graphs using the Metropolis-Hastingsalgorithm. The connectivity of the graphs has implications on how fast the algorithm converges. Inthis paper, we study a class of fiber graphs with elementary combinatorial techniques and provideresults that support a recent conjecture of Engström: the connectivity is given by the minimumvertex degree.
Varieties with maximum likelihood degree one
Authors: Huh June
Published: July 2015

We show that algebraic varieties with maximum likelihood degree one are exactlythe images of reduced A-discriminantal varieties under monomial maps with nite bers. Themaximum likelihood estimator corresponding to such a variety is Kapranov's Horn uniformization.This extends Kapranov's characterization of A-discriminantal hypersurfaces to varieties of arbitrarycodimension.
Maximum Likelihood for Matrices with Rank Constraints
Authors: Hauenstein Jonathan
Published: July 2015

Maximum likelihood estimation is a fundamental optimization problem in statistics. Westudy this problem on manifolds of matrices with bounded rank. These represent mixtures of distributionsof two independent discrete random variables. We determine the maximum likelihood degree for a rangeof determinantal varieties, and we apply numerical algebraic geometry to compute all critical points oftheir likelihood functions. This led to the discovery of maximum likelihood duality between matrices ofcomplementary ranks, a result proved subsequently by Draisma and Rodriguez.
Estimation for Dyadic-Dependent Exponential Random Graph Models
Authors: Yang Xiaolin , Rinaldo Alessandro , Fienberg Stephen E.
Published: July 2015

Graphs are the primary mathematical representation for networks, with nodes or verticescorresponding to units (e.g., individuals) and edges corresponding to relationships. ExponentialRandom Graph Models (ERGMs) are widely used for describing network data because of theirsimple structure as an exponential function of a sum of parameters multiplied by their correspondingsucient statistics. As with other exponential family settings the key computational dicultyis determining the normalizing constant for the likelihood function, a quantity that depends onlyon the data. In ERGMs for network data, the normalizing constant in the model often makesthe parameter estimation intractable for large graphs, when the model involves dependence amongdyads in the graph. One way to deal with this problem is to approximate the likelihood functionby something tractable, e.g., by using the method of pseudo-likelihood estimation suggested inthe early literature. In this paper, we describe the family of ERGMs and explain the increasingcomplexity that arises from imposing dierent edge dependence and homogeneous parameter assumptions.We then compare maximum likelihood (ML) and maximum pseudo-likelihood (MPL)estimation schemes with respect to existence and related degeneracy properties for ERGMs involvingdependencies among dyads.
Generic Identication of Binary-Valued Hidden Markov Processes
Authors: Schönhuth Alexander
Published: July 2015

The generic identication problem is to decide whether a stochastic process (Xt) is ahidden Markov process and if yes to infer its parameters for all but a subset of parametrizationsthat form a lower-dimensional subvariety in parameter space. Partial answers so far availabledepend on extra assumptions on the processes, which are usually centered around stationarity.Here we present a general solution for binary-valued hidden Markov processes. Our approach isrooted in algebraic statistics hence it is geometric in nature. We nd that the algebraic varietiesassociated with the probability distributions of binary-valued hidden Markov processes are zerosets of determinantal equations which draws a connection to well-studied objects from algebra. Asa consequence, our solution allows for algorithmic implementation based on elementary (linear)algebraic routines.
Los 68: encuentro de muchas historias y culminación de muchas batallas
Authors: Pozas Horcasitas Ricardo
Published: July 2015

El presente texto se mueve en el entramado de los eventos que fueron forjando la imagen y la representación de los sesenta por los habitantes de ese tiempo histórico, hasta desembocar en los movimientos estudiantiles de 1968, movimientos sociales que son su culminación y que condensan, política y culturalmente, las transformaciones surgidas durante la segunda posguerra mundial.AbstractIn this essay the author wanders through the events that forged the image and the representation of the sixties, culminating in the 1968 student movements. These movements are the cultural and political condensation of the transformations that emerged in the post- World War II period.
Propuesta de un modelo de co-gestión para los Pequeños Abastos Comunitarios de Agua en Colombia
Authors: Bernal Andrea , Rivas Luis , Peña Pilar
Published: July 2015

Este artículo recopila la evolución conceptual de la gestión comunitaria a partir de diferentes perspectivas: capital social, bienes comunes y co-gestión o gestión colaborativa y presenta las principales estrategias de co-gestión aplicadas al abastecimiento de agua: el modelo de desarrollo local conducido por la comunidad y la localidad o LCDD y el modelo consensuado de suministro o Triple S. Con este sustento teórico, se propone un modelo conceptual de co-gestión para pequeños abastos comunitarios de agua en Colombia, modelo de enfoque territorial y funcional que incorpora diferentes niveles de gobernanza (comunitario/local, regional y nacional) con funciones articuladas en espacios anidados, para garantizar el acceso al agua potable en comunidades rurales.AbstractThis paper reviews the conceptual evolution of Community Based Monitoring (CBM) from different approaches : social capital, common pool resources and co-management or collaborative management, and presents the main co-management strategies applied to water supply at small scale: local and community driven development (LCDD) and sustainable services at scale (SSS). Supported by this theoretical background, and in order to improve access to drinking water in rural communities in Colombia, the authors propose a co-management model for small and community water supplies.
Las remesas y el bienestar en las familias de migrantes
Authors: Corona Miguel Ángel
Published: July 2015

En este artículo se presentan los resultados de una investigación sobre el uso de las remesas en familias de migrantes y la repercusión en su bienestar, así como sobre la migración como estrategia para sobrevivir, adaptarse y participar en la globalización, dentro de un contexto económico nacional desfavorable. Nos situamos particularmente en la comunidad de San Jerónimo Coyula, en el estado de Puebla, caracterizada por su alta migración. Los resultados obtenidos muestran que las remesas en los hogares encuestados tuvieron un efecto positivo en su desarrollo y bienestar, por lo que se infiere que la migración ha sido y seguirá siendo la estrategia de los hogares para integrarse a los flujos de la globalización y alejarse de los riesgos del empobrecimiento en el lugar de origen.AbstractThis article explores the use of remittances in migrant households of San Jeronimo Coyula, Puebla, and its impact on their well-being. San Jeronimo Coyula is the hometown of many migrants of the state of Puebla living in New York. Results show that households believe that remittances have significantly improved their life conditions. It is inferred that migration has been and will continue to be the strategy of households to join in globalization flows and move away from the risks of impoverishment in their place of origin.
The Right to the City. Popular Contention in Contemporary Buenos Aires de Gabriela Ippolito-O´Donnell
Authors: Alarcón Olguín Víctor
Published: July 2015

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Hydrological and biogeochemical controls on watershed dissolved organic matter transport: pulse‐shunt concept
Authors: Raymond Peter A. , Saiers James E. , Sobczak William V.
Published: July 2015

Hydrological precipitation and snowmelt events trigger large “pulse” releases of terrestrial dissolved organic matter (DOM) into drainage networks due to an increase in DOM concentration with discharge. Thus, low‐frequency large events, which are predicted to increase with climate change, are responsible for a significant percentage of annual terrestrial DOM input to drainage networks. These same events are accompanied by marked and rapid increases in headwater stream velocity; thus they also “shunt” a large proportion of the pulsed DOM to downstream, higher‐order rivers and aquatic ecosystems geographically removed from the DOM source of origin. Here we merge these ideas into the “pulse‐shunt concept” (PSC) to explain and quantify how infrequent, yet major hydrologic events may drive the timing, flux, geographical dispersion, and regional metabolism of terrestrial DOM. The PSC also helps reconcile long‐standing discrepancies in C cycling theory and provides a robust framework for better quantifying its highly dynamic role in the global C cycle. The PSC adds a critical temporal dimension to linear organic matter removal dynamics postulated by the river continuum concept. It also can be represented mathematically through a model that is based on stream scaling approaches suitable for quantifying the important role of streams and rivers in the global C cycle. Initial hypotheses generated by the PSC include: (1) Infrequent large storms and snowmelt events account for a large and underappreciated percentage of the terrestrial DOM flux to drainage networks at annual and decadal time scales and therefore event statistics are equally important to total discharge when determining terrestrial fluxes. (2) Episodic hydrologic events result in DOM bypassing headwater streams and being metabolized in large rivers and exported to coastal systems. We propose that the PSC provides a framework for watershed biogeochemical modeling and predictions and discuss implications to ecological processes.
Body size‐based trophic structure of a deep marine ecosystem
Authors: Romero‐Romero Sonia , Molina‐Ramírez Axayacatl , Höfer Juan , Acuña José Luis
Published: July 2015

Nitrogen stable isotope ratios (δ15N) and body size were used to describe the size‐based trophic structure of a deep‐sea ecosystem, the Avilés submarine Canyon (Cantabrian Sea, Southern Bay of Biscay). We analyzed δ15N of specimens collected on a seasonal basis (March 2012, October 2012, and May 2013), from a variety of zones (benthic, pelagic), taxa (from zooplankton through invertebrates and fishes to giant squids and cetaceans), or depths (from surface to 4700 m) that spanned nine orders of magnitude in body mass. Our data reveal a strong linear dependence of trophic level on body size when data were considered either individually, aggregated into taxonomical categories, or binned into size classes. The three approaches render similar results that were not significantly different and yielded predator:prey body mass ratios (PPMR) of 1156:1, 3792:1 and 2718:1, respectively. Thus, our data represent unequivocal evidence of interspecific, size‐based trophic structure of a whole ecosystem based on taxonomic/functional categories. We studied the variability in δ15N not explained by body mass (W) using linear mixed modeling and found that the δ15N vs. log10Wrelationship holds for both pelagic and benthic systems, with benthic organisms isotopically enriched relative to pelagic organisms of the same size. However there is a marked seasonal variation potentially related to the recycling state of the system.
Negative competitive effects of invasive plants change with time since invasion
Authors: Iacarella Josephine C. , Mankiewicz Phoebe S. , Ricciardi Anthony
Published: July 2015

Competitive impacts of invasive species may vary across invaded ranges, owing to spatio‐temporal gradients in adapted traits and abundance levels. Higher levels of interspecific competition in recently invaded areas may lead invaders to be more competitive. Here, using meta‐analysis and home range estimation techniques, we examine how negative competitive effects of invasive species vary across different spatio‐temporal invasion contexts. We conducted a meta‐analysis of 26 studies that used greenhouse microcosm and common garden pairwise experiments to measure the growth response of native plants in the presence of terrestrial plant invaders (totaling 36 species), and compared this to the time since invasion at the collection site (number of years between the estimated year of initial invasion, by spread of the invader, and the time of collection for the study). We show that negative competitive effects decline across sites that had been invaded for longer periods of time, with effects of invasive grasses declining more rapidly over time than forbs, herbs and shrubs. To our knowledge, only two studies have directly measured competitive or consumptive effects of invaders across a gradient of time since invasion; our study is the first to identify a general pattern of temporal variation of competitive effects that may be attributed to intraspecific trait differences. Management efforts may be guided by such spatio‐temporal patterns of invader impact, particularly for grasses.
Acid-Soluble Plugs—Pressure-Tight Solution for a Preperforated Liner
Authors: Livingston E.. , Bjornen K.. , Burkhead D. W. , Gilbert W. W. , Kent A. W. , Leitch J.. , Zhou L..
Published: July 2015

This paper covers the development, laboratory testing, and field testing of acid-soluble-plug (ASP) technology as a viable completion alternative to wireline- or tubing-conveyed perforating. The ASPs are installed in a preperforated reservoir liner and dissolve when soaked in acid, allowing access to the reservoir. This allows the technology to be easily applied in reservoirs in which matrix acid jobs or acid-fracturing techniques are used.

The ASP technology was developed to reduce risk and cost associated with wireline- and tubing-conveyed perforating. ASPs were designed, manufactured, and field tested in both 5-in. and 7.625-in. reservoir liner sizes for wells in the Ekofisk field. The combination of laboratory testing and large-scale field testing influenced the design of the ASPs as well as the additives used in the acid systems used to dissolve them. From concept to initial field implementation, the process of ASP-engineering development took more than 2 years.

The concept was in the beginning field-tested in deviated injectors, with ASPs installed in the deepest section of the reservoir liner. The field tests proved the ASP concept before depending on the technology in a horizontal producer with an uncemented, tubing-in-liner completion solution. The field tests showed that acid soaking dissolved the ASPs in the downhole environment and allowed efficient acid stimulation of the reservoir. It also reduced the number of wireline runs necessary to complete the well.

When field tested in a tubing-in-liner completion application, installation of the ASPs in the reservoir liner eliminated tubing-conveyed-perforating runs. The reservoir liner was uncemented with mechanical openhole packers for zonal isolation. The ASPs provided a pressure-tight reservoir liner to set the packers against and eliminated fluid loss during the running of the inner completion string.

Optimization of this technology is an ongoing process. The plug design itself continues to evolve as well as the operational steps to minimize the soaking time necessary to dissolve the plugs and to gain access to the reservoir.
Acute Versus Progressive Onset of Diabetes in NOD Mice: Potential Implications for Therapeutic Interventions in Type 1 Diabetes
Authors: Mathews Clayton E. , Xue Song , Posgai Amanda , Lightfoot Yaima L. , Li Xia , Lin Andrea , Wasserfall Clive , Haller Michael J. , Schatz Desmond , Atkinson Mark A.
Published: July 2015

Most natural history models for type 1 diabetes (T1D) propose that overt hyperglycemia results after a progressive loss of insulin-secreting β-cell mass and/or function. To experimentally address this concept, we prospectively determined morning blood glucose measurements every other day in multiple cohorts (total n = 660) of female NOD/ShiLtJ mice starting at 8 weeks of age until diabetes onset or 26 weeks of age. Consistent with this notion, a majority of mice that developed diabetes (354 of 489 [72%]) displayed a progressive increase in blood glucose with transient excursions >200 mg/dL, followed by acute and persistent hyperglycemia at diabetes onset. However, 135 of the 489 (28%) diabetic animals demonstrated normal glucose values followed by acute (i.e., sudden) hyperglycemia. Interestingly, diabetes onset occurred earlier in mice with acute versus progressive disease onset (15.37 ± 0.3207 vs. 17.44 ± 0.2073 weeks of age, P < 0.0001). Moreover, the pattern of onset (i.e., progressive vs. acute) dramatically influenced the ability to achieve reversal of T1D by immunotherapeutic intervention, with increased effectiveness observed in situations of a progressive deterioration in euglycemia. These studies highlight a novel natural history aspect in this animal model, one that may provide important guidance for the selection of subjects participating in human trials seeking disease reversal.
Hippocampal Insulin Resistance Impairs Spatial Learning and Synaptic Plasticity
Authors: Grillo Claudia A. , Piroli Gerardo G. , Lawrence Robert C. , Wrighten Shayna A. , Green Adrienne J. , Wilson Steven P. , Sakai Randall R. , Kelly Sandra J. , Wilson Marlene A. , Mott David D. , Reagan Lawrence P.
Published: July 2015

Insulin receptors (IRs) are expressed in discrete neuronal populations in the central nervous system, including the hippocampus. To elucidate the functional role of hippocampal IRs independent of metabolic function, we generated a model of hippocampal-specific insulin resistance using a lentiviral vector expressing an IR antisense sequence (LV-IRAS). LV-IRAS effectively downregulates IR expression in the rat hippocampus without affecting body weight, adiposity, or peripheral glucose homeostasis. Nevertheless, hippocampal neuroplasticity was impaired in LV-IRAS–treated rats. High-frequency stimulation, which evoked robust long-term potentiation (LTP) in brain slices from LV control rats, failed to evoke LTP in LV-IRAS–treated rats. GluN2B subunit levels, as well as the basal level of phosphorylation of GluA1, were reduced in the hippocampus of LV-IRAS rats. Moreover, these deficits in synaptic transmission were associated with impairments in spatial learning. We suggest that alterations in the expression and phosphorylation of glutamate receptor subunits underlie the alterations in LTP and that these changes are responsible for the impairment in hippocampal-dependent learning. Importantly, these learning deficits are strikingly similar to the impairments in complex task performance observed in patients with diabetes, which strengthens the hypothesis that hippocampal insulin resistance is a key mediator of cognitive deficits independent of glycemic control.
Improving bridge infrastructure through rehabilitation
Authors: Manjure Padmakar
Published: July 2015

Bridges are the vital infrastructure elements of Indian Railways and Highways network. There are more than 200,000 bridges on this system. Maintaining them in safe and serviceable condition gets high priority. At times, they get adversely affected and are required to be rehabilitated by adopting novel techniques. In the process, study of causes of deterioration has revealed that there is potential improvement possible to enhance durability aspects.

Similarly, improvements are required to be done in bridge structures due to situational, environmental and loading changes. How these improvements are done is described in this article.
Replacement of the Woodrow Wilson Memorial Bridge Bascule Span
Authors: Arzoumanidis Serafim G. , Bluni Sean A.
Published: July 2015

A mile-long signature replacement structure has been designed to replace the Woodrow Wilson Memorial Bridge on the I-95 Interstate System. With eight independent bascule leaves and a movable mass of 19000 metric tons, the bascule span is the largest movable bridge in the U.S. and possibly the world. To meet extraordinary public demands, the new bascule bridge has been constructed with many unique features including aesthetic V-shaped concrete piers, fully-composite concrete decks, moment-transferring span locking system, details to accommodate a future transit system, and a fully-redundant electrical control system. These components are amongst the innovative, interdisciplinary features described in this paper.
Parameter- and system identification on bridges with optimization methods
Authors: Schlegel Roger , Will Johannes
Published: July 2015

Close to reality computation of the serviceability, durability and load-carrying capacity of old masonry and concrete arch bridges for rising live loads is a current problem. In Germany many of such road- and railway bridges exist. Some of the most important features for applicable numerical evaluation of arch bridges are a realistic structural model, the consideration of the nonlinear load history and in particular the inclusion of realistic nonlinear material models applicable for historical masonry.

Often input parameters necessary for a realistic simulation are unknown. Then e.g. material and geometry data must be determined by measurements. In particular at historical masonry bridges these data can show relatively strong variance. By sensitivity studies can be determined correlation between the input data variance and output value variation of the computation model. As basis of measuring program so the most important input values can be determined. Sometimes some input values can be measured only indirectly. In these cases parameter identifications can be used for the determination of the input values and for validating the computation model.

The paper presents powerful strategies for sensitivity analysis with stochastic sampling methods and for identification problems with optimization algorithms. Several examples from a masonry arch bridge demonstrate the application of these methods. The material behaviour described by the presented practical applications with powerful three-dimensional continuum models for regular and irregular masonry types. On this basis it is possible to simulate masonry specific failure and damage mechanisms.
Modeling of bearings in structural systems for bridges
Authors: Freundt Ursula , Vogt Ralf
Published: July 2015

This paper deals with the representation of laminated rubber bearings in structural systems of bridges. First the main properties of rubber bearings, including the load-deflection-behavior and the moment-rotation-behavior, are presented. These are obtained from experiments and from numerical calculations. Since the properties are in general nonlinear, a series of idealizations are used and explained.

From these properties linearizations are derived, that are commonly used in an analysis of a bridge structure.

For the use with finite- element analysis of structural systems, then a special finite element is introduced, which is able to map some nonlinear characteristics of a real rubber bearing and can handle the interaction between horizontal, vertical and rotational loads. In addition, geometrical nonlinear effects will be taken into account.

The paper closes with an example of a calculation of a bridge structure using the different concepts and representations of the bearings in the structural model. The differences in internal forces and displacements are shown.
Automation based structural monitoring systems for ordinary bridges
Authors: Kiviluoma Risto
Published: July 2015

Demography of bridge stocks in various organisations and countries show great number of small bridges, making them of special interest in bridge management and life-cycle engineering. Improvements in analysis methods, input reliability or accuracy of bridge management systems will have notable impact to overall life-cycle costs. Recent progress in automation technology has revealed possibility to develop bridge monitoring systems, which by their properties are suitable to widespread usage for ordinary small bridges. In the near future, bridge management systems may consist on two bridge groups for “not instrumented” and “instrumented” bridges. Aim of this paper is to describe one example of implementing automation based bridge monitoring system, and discuss its integration into bridge management. It also addresses some envisaged developments in various disciplines to fully take benefit of the possibilities of the technology.
Experimental study on vibration mitigation of long stay cables using cross ties
Authors: Sun Limin , Zhou Yagang
Published: July 2015

Stay cables in cable-stayed bridges are susceptible to large-amplitude vibration caused by wind, rain and support motion due to their large flexibility, small mass and low inherent damping. Using cross ties is one of the considerable countermeasures for vibration mitigation of stay cables, especially longer ones. In this study, free vibration tests were conducted using a scaled cable system model which consists of three stayed cables connected by a cross tie. The effects of tensioning method, initial tension and stiffness of cross ties on in-plane and out-of-plane vibration mitigation of the cable system were investigated. The test results were explained based on the theoretical analyses by the finite element method and the energy based method. The measured frequencies of cable system are approximately the same as the theoretical ones and the measured damping has the same tendency as that from the theoretical studies.
Facility Management for an improved serviceability of road tunnels
Authors: Heimbecher Frank , Kaundinya Ingo
Published: July 2015

A very high service availability is important for the operator and for the user of road tunnels, too.
The service availability of a structure is directly related to its quality. The earlier quality assurance
measures are being considered during the life cycle, the better a structure of high quality can be
guaranteed. Problems which occur during the operation period of a structure often result from
design errors or from inadequate realisation during the construction phase. They may also occur as
a result of wrongly planned maintenance and refurbishment works. Thus, the transfer of specific
data, information and experiences through the whole life cycle is very important. In this context
methods of facility management can provide efficient assistance when they have already been used
throughout all three classic phases of a structure‘s life cycle - planning, construction and operation.
Finally the tunnel drainage system of German road tunnels is considered as an example as practical
application possibility.
End-to-end Maintenance Management of Major Bridges and Tunnels using the Internet-based DANBRO+ System
Authors: Bjerrum John , Tuxen Jens Kristian , Lassen Bjørn Nordgaard , Jensen Finn M.
Published: July 2015

This paper presents DANBRO+, which is an Internet-based client-server system, tailor-made for handling of all activities such as routine, principal and special inspections together with all maintenance, rehabilitation and repair activities on major bridges and tunnels. DANBRO+ has been developed during 2003-2006 and will used for all operation and maintenance tasks related to the 40 major bridges and traffic tunnels administered by The Danish Road Directorate beginning in the spring of 2007. The system is based on 30 years of experience with systematic maintenance of major structures and 20 years of experience with the DANBRO system for minor bridges. DANBRO+ has been designed to support all management levels of the bridge owner’s organization as well as consultants, contractors, suppliers and others participating in the operation and maintenance of the structures.
Differences in maintenance of bridges and real estate buildings
Authors: Bargstaedt Hans-Joachim , Ailland Karin
Published: July 2015

The paper considers the differently developed maintenance strategies and lifecycle considerations of federal bridges and industrial facilities. These differences are mostly caused by the interests and objectives of the stakeholders. The maintenance management of bridges can be defined more easily owing to objectives that stand firm. The type of use won’t change in a bridges lifetime. By contrast the requirements of an industrial building can change rapidly and frequently. Other differences are on one hand the improvement of infrastructure and on the other hand the increase of facility output.

The different goals of facility management activities are discussed in the aspect of economy, of maintaining the value and substance respectively, and in terms of bound capital.