bluuebunny/crossref_metadata_2025 huggingface dataset:
Teacher Feedback and the Acquisition of Simple Past Tense: A Case of EFL Learners
Authors: Shabani Karim , Ghasem Dizani Elham
Published: June 2015

English language teaching has been seeking new ways to teach grammar interactively. The present research looked into the crucial role of interactional feedback and focus on form in the acquisition of simple past tense in speaking tasks within a mixed-method approach. The study was conducted by the participation of 59 upper-intermediate learners between 17 to 30 years of age in 10 treatment sessions in an Iranian EFL (English as a foreign language) context. The learners were assigned into four groups of implicit, explicit, mixed, and control. The number of the structures focused in each interactional group varied, i.e. the implicit group received feedback as simple past, while the explicit was given corrective feedback (CF) on both simple past and past continuous. However, the mixed group dealt with simple past, past continuous, and also pronouns. Findings highlighted the effectiveness of CF since all the interactional groups could outperform the control group, which received no feedback type. Regarding the number of the structures focused, it was found that although implicit group only focused on a single structure, it could not outperform other groups. In other words, both explicit and mixed group performed significantly better than the implicit group in spite of being focused on more than one grammatical point. In sum, it could be inferred from the current study that the kind of feedback given to the learners, i.e. implicit or explicit, can lead to more opportunities of learning rather than being focused on a single structure. Therefore, teachers should provide learners with the correct form wherever possible without considering the number of points corrected in each feedback but by paying attention to the degree of explicitness of the CF given to the learners.
“Soper at Oure Aller Cost”:
Authors: Archer Jayne Elisabeth , Turley Richard Marggraf , Thomas Howard
Published: June 2015

The reward for the best storyteller among the pilgrims in Chaucer's Canterbury Tales is a meal: “soper at oure aller cost” (I 799). This narrative detail gives tangible form to the traditional association between literary creation and arable farming. Chaucer's diverse pilgrims and the tales they tell are woven together by the language, tropes, and contemporary concerns relating to anxieties about the production, supply, distribution, purity, and quality of food. Focusing on the figure of the Plowman, the apocryphal Plowman's Tale, and the Reeve's Tale, and reading them in the context of sociopolitical and religious dissent (the 1381 Peasants' Revolt and Lollardy respectively), this essay traces the ways in which the Canterbury Tales engages with the politics and poetics of food supply in the final decades of the fourteenth century.
Wynkyn de Worde's Lost Manuscript of the Canterbury Tales:
Authors: Tokunaga Satoko
Published: June 2015

Previous scholarship has argued that the manuscript (*W) used by Wynkyn de Worde for his 1498 edition of the Canterbury Tales (Wn) was derived from the same line of descent as Gg (Cambridge University Library MS Gg.4.27) and Ph1 (The University of Texas, The Harry Ransom Center MS 46). Most recently, Stephen Partridge, examining the glosses of Wn, has proposed a theory that two types of glossed text, an El-Ll2 type and a Gg-Ph1-Wn type, were derived from a common lost source, and that a further stage of copying of a Gg-Ph1-Wn type led to Gg and Ph1 with glosses largely omitted and Wn with glosses. My extensive textual analyses of Wn have advanced this theory, and show that Wn/*W is textually closer to Ph1 than Gg and retains more archetypal readings than these two manuscripts. These findings strengthen the possibility that a copying of *W led to the production of Gg and Ph1, or a manuscript behind them.
“Now Kynde me avenge”:
Authors: Pfrenger Andrew
Published: June 2015

This article considers the ambiguity underlying Conscience's call for vengeance in the final lines of Piers Plowman (B.20.385–86). Thorough analysis of Langland's treatment of vengeance as a form of justice elsewhere in the poem reveals a process of redefinition that transforms vengeance from a violent act of retributive justice to a tempered act of restorative justice. By contextualizing this process within the popular literature and influential moral theology of Langland's day, one discovers a theory of justice that includes a considered awareness of human psychology, specifically the influence of negative emotions like hatred and anger. Viewed in light of these factors, Conscience's call for vengeance becomes a cry for mercy and love in society.
Moral Obligations, Virtue Ethics, and Gentil Character in Chaucer's Franklin's Tale
Authors: Greene Darragh
Published: June 2015

The Franklin's Tale provides an answer to the ethical question par excellence: how ought one to live in order to secure happiness? It will be shown how Chaucer carefully chooses and constructs a fitting teller, for the Franklin's most distinctive characteristic, liberality or generosity, is essential to the solution of the ethical problem presented in his story. Moreover, the tale itself implicitly questions the coherence and efficacy of law-based morality, specifically that of deontological obligations. As an alternative, the Franklin recommends virtue ethics, that is, living in accordance with the value system of gentillesse in order to develop a gentil character, which secures such happiness as is possible in an imperfect world.
Bourgeois Ethics Again:
Authors: Critten Rory G.
Published: June 2015

This essay focuses on the interrelationship of the romances and the conduct poems contained in Oxford, Bodleian Library MS Ashmole 61 (ca. 1500). Drawing on the work of Felicity Riddy, it examines the contrasting ways in which these texts articulate a particular bourgeois ethos. Tensions that arise from their different approaches to this phenomenon are read as evidence of an attitude towards the matter of good conduct that is at once more searching and more provisional than that which has typically been attributed to the milieu in which Ashmole 61 was copied and read.
The Meanings of Middle English Wight
Authors: Farrell Thomas J.
Published: June 2015

E. Talbot Donaldson's emendation of CT, III 117 to “And of so parfit wis a wrighte ywroughte,” not adopted in the recent Variorum volume, rests on insufficiently established evidence. I demonstrate that Donaldson himself retracts crucial aspects of his argument; that Middle English usage shows both ambiguity and significant overlap between the word wight and divine beings (especially the second person of the Trinity); that Chaucer, who adheres to Donaldson's categorical distinction in Troilus, abandons it in the Canterbury Tales; and that various writers in the Christian tradition designate as the Creator (the point at issue in this line) Jesus the Christ: the second person of the Trinity whom it is unambiguously possible to call a wight. Donaldson's emendation remains possible, but the case for making it is much weaker than we have long supposed.
Staging the Reception of American Ethnic Authors in Women's Popular Magazines:
Authors: Vechinski Matthew James
Published: June 2015

This article investigates how Amy Tan's The Joy Luck Club penetrated the mainstream with the help of magazines read by millions of women and teenage girls. Seventeen and Ladies' Home Journal first published two stories from the book that were edited to isolate the relationships between Chinese immigrant mothers and their American-born daughters. This emphasis in turn simplified the stories' representation of Chinese-American families and peer groups, offering a way for the magazines to appeal to their audiences' existing cultural assumptions. The book's title story as edited for Ladies' Home Journal celebrates an adult daughter's renewed interest in her mother's traditions, and the version of “The Rules of the Game” that appeared in Seventeen champions a talented young daughter asserting her independence from her mother. In addition to the reception of these stories in the context of women's magazines, the article considers readers' responses to The Joy Luck Club book—an example of a short story cycle by an ethnic American author. Audiences outside the academy have found it difficult to read across interlinking stories, which limits their level of engagement with the text. The demanding fictional form of Tan's book, much like the truncated magazine versions of the stories, may actually encourage shallow interpretations of the struggles of its ethnic American characters.
Asian American Literature and Reading Formations:
Authors: Layfield Allison
Published: June 2015

Since the 1970s, literature by Asian American women writers has made a significant impact on the American literary canon. But despite these gains, this article argues that the reception of Asian American literature is limited not only by aesthetics and literary value, but by several factors specific to the perceived racial and national identity of its authors or characters. Through a reception study of two novels by Nora Okja Keller, Comfort Woman and Fox Girl, Layfield argues that a positive reception of Asian American women's literature depends on several key factors: first, readers want to experience the situation of Asian women; second, the story of this “other” needs to be told in a familiar structure associated with Asian American literature, such as the mother-daughter tale; and finally, this story needs to conform to successful immigration stories in which the heroine reaffirms the importance of the nuclear family and portrays immigration to the United States as a means of salvation.
Encountering the Islamic Other in Print:
Authors: Carter Perry L.
Published: June 2015

This article presents the results of a content analysis and a thematic analysis of undergraduate students’ essays on the Middle East, specifically on the nation of Iran. The students were all members of a world regional geography class taught at a public west Texas university during the Fall of 2002. These students’ writings provide a particular regional view of the Islamic world post- September 11, 2001. The essays are responses to Christiane Bird's travelogue Neither East nor West. Bird's book, published before the September 11, 2001, attacks, offers a balanced if not positive view of Islam in general and Iran in particular. The written narratives produced by students afford an aperture into their imagined geographies and figured worlds of the Middle East and the Muslim world.
Ten Years of Cooperation Between Mobile Robots and Sensor Networks
Authors: Capitán Fernández Jesus , Martinez-de-Dios Jose Ramiro , Maza Ivan , Ramon Fabresse Felipe , Ollero Anibal
Published: June 2015

This paper presents an overview of the work carried out by the Group of Robotics, Vision and Control (GRVC) at the University of Seville on the cooperation between mobile robots and sensor networks. The GRVC, led by Professor Anibal Ollero, has been working over the last ten years on techniques where robots and sensor networks exploit synergies and collaborate tightly, developing numerous research projects on the topic. In this paper, based on our research, we introduce what we consider some relevant challenges when combining sensor networks with mobile robots. Then, we describe our developed techniques and main results for these challenges. In particular, the paper focuses on autonomous self-deployment of sensor networks; cooperative localization and tracking; self-localization and mapping; and large-scale scenarios. Extensive experimental results and lessons learnt are also discussed in the paper.
Editor's Comments
Authors: Gerrity Robert
Published: June 2015

Editor's Comments
THE ORGANISATION OF DRILL PRODUCTION AT A NEOLITHIC LITHIC WORKSHOP SITE OF BAI BEN, CAT BA ISLAND, VIETNAM
Authors: Nguyen Dong Truong , Clarkson Chris
Published: June 2015

We investigate stone drill point production, use, maintenance, and discard from a technological perspective at the Late Neolithic workshop of Bai Ben on Cat Ba Island, Northeastern Vietnam. Bai Ben contains over 18,000 retouched chert flakes classified as drill points and dating to c.3000BP. Large scale production of drills most likely took place for reasons of mass production of drilled organic and inorganic objects. Few of such drilled objects are found at the site, perhaps due to poor organic preservation or removal of finished objects for trade and exchange. An analysis of attribute on drills and cores examines the time-ordering of dimensional and morphological changes as reduction continued at the site. The research finds that drills were produced from a diverse range of nodules sizes, blanks, core technologies and raw materials, but similar blanks were selected to produce very similar drill point forms.
Els exempla de Valeri Màxim a la literatura catalana medieval
Authors: Rovira Cerdà Helena
Published: June 2015

Resum: Diverses obres en llengua catalana dels s. XIV-XV contenen nombrosos exempla procedents, de forma directa o indirecta, dels Dictorum factorumque memorabilium libri novem de Valeri Màxim. En aquest article incloem una taula on es localitzen 233 episodis de l’autor romà en 24 obres escrites en català, tant originals com traduccions. A més, analitzem el procés de transmissió dels episodis inclosos en el Memorial del pecador remut de Felip de Malla, la Doctrina compendiosa atribuïda per uns a Francesc Eiximenis i per altres a Ramon Soler, la Doctrina moral de Nicolau de Pacs, el Llibre del joc dels escacs de Jaume de Cèssulis, el Recull d’exemples d’Arnau de Lieja, i altres obres amb una presència més esporàdica d’episodis dels Dicta com ara l’anònim Curial e Güelfa, La nau de Lleonard de Sors i les Flors de virtut e de costums traduïdes per Francesc de Santcliment.   Paraules clau: Valeri Màxim, exempla, oratòria, intertextualitat, literatura catalana medieval.   Abstract: Many works written in Catalan during the XIV and XV centuries transmit several exempla from the Dictorum factorumque memorabilium libri novem of Valerius Maximus. In this paper we include a table with the exact location of 233 episodes in 24 Catalan works. Moreover, we examine more deeply the transmission of these episodes in Felip de Malla’s Memorial del pecador remut, the Doctrina compendiosa attributed by some to Francesc Eiximenis and by others to Ramon Soler, the Doctrina moral of Nicolau de Pacs, the Llibre del joc dels escacs of Jacobus de Cessolis, the Recull d’exemples of Arnold of Liége, and some other works with less passages related to Valerius Maximus, as the anonymous Curial e Güelfa, La nau of Lleonard de Sors and the Flors de virtut e de costums translated by Francesc de Santcliment.   Key words: Valerius Maximus, exempla, oratory, intertextuality, medieval Catalan literature.
Omaggio a Joan Vinyoli
Authors: Ripa Valentina
Published: June 2015

Riassunto: In continuità con l’omaggio a Joan Vinyoli organizzato a Roma nel 2014, si propongono le traduzioni in italiano di alcuni suoi componimenti, con testo a fronte.   Parole chiave: Joan Vinyoli, traduzione dal catalano all’italiano, poesia catalana del Novecento.   Abstract: In continuity with the Joan Vinyoli Tribute organized in Rome in December 2014, I propose the translation from Catalan to Italian of some of his poems.  Keywords: Joan Vinyoli, translation from Catalan to Italian, twentieth-century Catalan poetry.
Italia e la Corona d’Aragona: Dai tempi dei Borgia ai nostri tempi
Authors: De Benedetto Nancy
Published: June 2015

Presentació del monogràfic.
The Evaluation of the Practical Implementation of Social Justice by the Judicial System of State
Authors: Iovan Marţian
Published: June 2015

Based on a sociological research, the author of this article aims to identify the beliefs and the attitudes of a group of BA and MA students enrolled in university programs of Juridical Science, regarding their apprehension of the principles of justice - as the central value of the Romanian judicial system. This would contribute to the implementation of justice in the actual Romanian economic, political, and judicial structure. The data analysis provides the necessary information for comprehending the extensions of justice and injustice within the specific social context. A real distance between reality and the political doctrines, and the classical and post-modern philosophical theories of justice as well can be noticed. The resulting conclusions could provide solid settings in order to develop a number of strategies/public policies to shape a more honest society.
Practice of European Court of Human Rights (ECHR) in the enforcement of courts’ final decisions
Authors: Gazidede Alkelina
Published: June 2015

The paper aims at highlighting the importance of enforcement of judicial decisions as a key factor in building Rule of Law. As courts do not have the opportunity to lead themselves the process of decisions’s execution and the respective institutions have performed poor results, many cases are presented in front of European Court of Human Rights due to the lack of efficiency in executing judicial decisions. Obtaining a favorable judicial decision does not imply necessarily the fulfillment of the general purpose, and ECHR through it’s judgements has argued that the right to proper administration of justice implies that the enforcement of court decisions should itself be effective and efficient. Being considered as a compulsory provision for the successful conclusion of a legal process, the enforcment of courts’ final decisions within a reasonable time is an essential element of a fair trial. Also, this paper analyses the circumstances when excuses such as case complexity or lack of funds are considered objective and what is the responsibility of the states toward organizing their judicial system so that the justice is awarded.
Individual Assessment of Judges in Albania - A General Overview and Comparative Analysis of Career Advancement and Reward Systems Based on Performance Evaluation
Authors: Malaj Alaudin
Published: June 2015

Assessment of judges in itself is one of the criteria in relation to the establishment of specific rules for the career of judges, creation of a healthy judicial system and a proper one. Professional Assessment process of judges based on objective, clear and transparent criteria, has a great importance for the consolidation of judicial power, because on its base, transfer and promotions of judges are performed only on the basis of individual merit. Considering the fact that the approximation of the Albanian legislation with the European one, has become a task of the Albanian legislator, the draft “On the evaluation system of judicial activity in RA” deserves special attention.This article takes in a comparative analysis the current law “On the individual assessment of judges in Albania” and the draft law “On the evaluation system of judicial activity in RA”. The main attention of the analysis focuses on some basic elements for evaluation of the judges, pointing to some basic procedures relevant and necessary in relation to the performance and their role in the process of administering justice in our country. In the analysis of this draft law we will mainly focus on the establishment of procedures, principles and criteria for professional and ethical assessment of the judges of courts of first instance and courts of appeal that predicts the draftlaw. In the following the article is focused on a comparative view of the assessment criteria, according to the Italian model. Analysis of the Italian system of individual assessment of judges may highlight on some the practical aspects of the most suitable model of assessment to be implemented in Albania.
Dictionary Use as Word Solving Strategy (WSS)
Authors: Mustafai Jusuf
Published: June 2015

L2 learners may try to pick up the unknown word’s meaning from a dictionary. Many different factors, such as how important the meaning of the word is in the passage, the number of unknown words, and the reason the students are working on it, etc., affect the frequency of the student’s use of the dictionary for help. However, trying to guess the meaning of the unknown word from the context before consulting a dictionary is more beneficial since this may help the learners to pick the correct meaning relevant to the text. Using a dictionary should be limited to those unguessable words whose meanings can hinder the learner’s understanding.
Dynamic subcellular localization of a respiratory complex controls bacterial respiration
Authors: Alberge François , Espinosa Leon , Seduk Farida , Sylvi Léa , Toci René , Walburger Anne , Magalon Axel
Published: June 2015

Respiration, an essential process for most organisms, has to optimally respond to changes in the metabolic demand or the environmental conditions. The branched character of their respiratory chains allows bacteria to do so by providing a great metabolic and regulatory flexibility. Here, we show that the native localization of the nitrate reductase, a major respiratory complex under anaerobiosis in Escherichia coli, is submitted to tight spatiotemporal regulation in response to metabolic conditions via a mechanism using the transmembrane proton gradient as a cue for polar localization. These dynamics are critical for controlling the activity of nitrate reductase, as the formation of polar assemblies potentiates the electron flux through the complex. Thus, dynamic subcellular localization emerges as a critical factor in the control of respiration in bacteria.
Loss of the liver X receptor LXRα/β in peripheral sensory neurons modifies energy expenditure
Authors: Mansuy-Aubert Virginie , Gautron Laurent , Lee Syann , Bookout Angie L , Kusminski Christine M , Sun Kai , Zhang Yuan , Scherer Philipp E , Mangelsdorf David J , Elmquist Joel K
Published: June 2015

Peripheral neural sensory mechanisms play a crucial role in metabolic regulation but less is known about the mechanisms underlying vagal sensing itself. Recently, we identified an enrichment of liver X receptor alpha and beta (LXRα/β) in the nodose ganglia of the vagus nerve. In this study, we show mice lacking LXRα/β in peripheral sensory neurons have increased energy expenditure and weight loss when fed a Western diet (WD). Our findings suggest that the ability to metabolize and sense cholesterol and/or fatty acids in peripheral neurons is an important requirement for physiological adaptations to WDs.
Argumentación en Enseñanza en Clase Completa y Aprendizaje de Ciencias
Authors: Larrain Antonia , Howe Christine , Cerda Julieta
Published: June 2015

La discusión de ideas contrarias entre estudiantes promueve el aprendizaje en ciencias. Existe evidencia que sugiere que la argumentación en clase completa tendría el mismo efecto, pero no está claro aún que se deba a la discusión. Este estudio evaluó el efecto de distintos aspectos de la argumentación en clase completa en el aprendizaje de ciencias. En una muestra no probabilística participaron 220 estudiantes (10 y 11 años de edad) de 18 escuelas municipales de Santiago, Chile. Once profesores dieron clases diseñadas para promover argumentación (grupo intervención) y 7 profesores lo hicieron en su forma habitual (grupo control). Los estudiantes fueron evaluados individualmente antes y después con pruebas de aprendizaje y argumentación y cuestionario de actitud hacia la ciencia. Se grabaron las clases. A través de análisis factoriales y regresiones lineares, los resultados mostraron que 2 factores predicen una parte de la varianza del aprendizaje: uno compuesto por enunciados justificativos y otro, por contra-argumentos de los estudiantes. Estos resultados sugieren que la contradicción entre pares no es el único aspecto de la argumentación en clase completa que promueve el aprendizaje.
Desarrollo de Habilidades de Observación en la Formación de Liderazgo Escolar a Través de Videos de Clases
Authors: Müller Magdalena , Volante Paulo , Grau Valeska , Preiss David D.
Published: June 2015

El estudio evalúa la efectividad en Chile de una intervención en el desarrollo de habilidades de observación de sala de clases en el marco de un programa de formación en liderazgo educacional con énfasis en prácticas de influencia instruccional. Se aplicó una estrategia de video formación a través de un formato semi-presencial con exposición simultánea y masiva a videos y prácticas de observación de clases. Se analizaron 171 registros de observación aplicados como pre y post-test en un lapso de 5 meses. Se analizó el foco con que observaban, operacionalizado en la noción de triángulo instruccional. Este permite apreciar cuán centrada o distribuida está la atención del observador en el desempeño del docente, la actividad del estudiante o el contenido curricular. Se realizaron pruebas de comparación de medias, utilizando la prueba t de Student para muestras relacionadas. También se analizaron las modalidades de observación, detectando énfasis descriptivos, interpretativos o evaluativos. Se evidencian cambios significativos en el patrón y modalidad de observación, lo que permite afirmar que las estrategias de video formación son efectivas para desarrollar habilidades de liderazgo instruccional.
Buenas Prácticas Pedagógicas Observadas en el Aula de Segundo Ciclo Básico en Chile
Authors: Preiss David D. , Calcagni Elisa , Espinoza Ana María , Gómez Daniela , Grau Valeska , Guzmán Valentina , Müller Magdalena , Ramírez Francisca , Volante Paulo
Published: June 2015

Se investigaron 1.482 videos de clases de profesores evaluados como competentes y destacados en los programas de evaluación y acreditación docente en Chile. Los videos se grabaron entre 2005 y 2010 en clases de segundo ciclo básico, en los subsectores de lenguaje y matemáticas. Aplicando la Pauta de Buenas Prácticas Docentes, se seleccionaron 151 videos que presentaban al menos un episodio con 2 o más prácticas destacadas en la pauta. Se realizaron análisis estadísticos descriptivos y correlacionales, análisis multivariados de varianza para evaluar diferencias por sexo y sector de enseñanza y un análisis de medidas repetidas para evaluar diferencias entre momentos de la clase en las variables identificadas. La mayoría de las buenas prácticas identificadas se implementa durante el desarrollo de la clase y busca concitar la participación de los estudiantes. La estrategia de enseñanza más observada es la explicitación de procesos de razonamiento. Estos patrones de enseñanza están vinculados a una concepción de la enseñanza como transmisión y son compatibles con el patrón externalista de enseñanza dominante en Chile.
Antenna Radiation Patterns
Authors: Chryssomallis Michael , Christodoulou Christos
Published: June 2015

The radiation pattern of an antenna is one of its basic properties since it shows the way the antenna distributes its energy in space. It generally consists of a number of lobes and if it is measured far away from the antenna it is independent of distance. It is a function of angles and can be expressed as field or power pattern. It usually can be completely specified from the patterns in two planes, perpendicular to each other, theEandHplanes, respectively. Related to the radiation pattern of an antenna, a number of important parameters exist, such as radiated power, radiation efficiency, directivity, gain, and antenna polarization.

The aim of this article is to provide an introduction to radiation patterns and all the related important parameters. The content is organized in five sections. The second section introduces several antenna patterns, giving the necessary definitions and presenting the common types. The field regions of an antenna are also pointed out. In the third section, after the introduction of Poynting vector and radiation power density, radiation performance measures such as the beam solid angle, directivity, and gain of an antenna are defined. In the fourth section, the concepts of wave and antenna polarizations are discussed. Finally, in the fifth section, a general case of antenna pattern calculation is considered, and numerical solutions are suggested for radiation patterns that are not available in simple closed‐form expressions.
Greedy Algorithms
Authors: Moshkov Mikhail
Published: June 2015

Greedy algorithms seek to find optimal solutions by making locally optimal steps. They form a class of usually simple (simple from the point of view of both description and time complexity) algorithms which often return optimal solutions or have good enough accuracy. This article presents representative greedy algorithms returning optimal solutions, such as Dijkstra's, Prim's, Huffman's, and Kruskal's algorithms. In addition, matroids, greedy algorithms for NP‐hard problems, the set cover problem as well as randomized greedy algorithms and greedy approaches for continuous models are also discussed.
A community benchmark for viscoplastic thermal convection in a 2‐D square box
Authors: Tosi N. , Stein C. , Noack L. , Hüttig C. , Maierová P. , Samuel H. , Davies D. R. , Wilson C. R. , Kramer S. C. , Thieulot C. , Glerum A. , Fraters M. , Spakman W. , Rozel A. , Tackley P. J.
Published: June 2015

Numerical simulations of thermal convection in the Earth's mantle often employ a pseudoplastic rheology in order to mimic the plate‐like behavior of the lithosphere. Yet the benchmark tests available in the literature are largely based on simple linear rheologies in which the viscosity is either assumed to be constant or weakly dependent on temperature. Here we present a suite of simple tests based on nonlinear rheologies featuring temperature, pressure, and strain rate‐dependent viscosity. Eleven different codes based on the finite volume, finite element, or spectral methods have been used to run five benchmark cases leading to stagnant lid, mobile lid, and periodic convection in a 2‐D square box. For two of these cases, we also show resolution tests from all contributing codes. In addition, we present a bifurcation analysis, describing the transition from a mobile lid regime to a periodic regime, and from a periodic regime to a stagnant lid regime, as a function of the yield stress. At a resolution of around 100 cells or elements in both vertical and horizontal directions, all codes reproduce the required diagnostic quantities with a discrepancy of at most
in the presence of both linear and nonlinear rheologies. Furthermore, they consistently predict the critical value of the yield stress at which the transition between different regimes occurs. As the most recent mantle convection codes can handle a number of different geometries within a single solution framework, this benchmark will also prove useful when validating viscoplastic thermal convection simulations in such geometries.
Driftcretions: The legacy impacts of driftwood on shoreline morphology
Authors: Kramer Natalie , Wohl Ellen
Published: June 2015

This research demonstrates how vegetation interacts with physical processes to govern landscape development. We quantify and describe interactions among driftwood, sedimentation, and vegetation for Great Slave Lake, which is used as proxy for shoreline dynamics and landforms before deforestation and wood removal along major waterways. We introduce driftcretion to describe large, persistent concentrations of driftwood that interact with vegetation and sedimentation to influence shoreline evolution. We report the volume and distribution of driftwood along shorelines, the morphological impacts of driftwood delivery throughout the Holocene, and rates of driftwood accretion. Driftcretions facilitate the formation of complex, diverse morphologies that increase biological productivity and organic carbon capture and buffer against erosion. Driftcretions should be common on shorelines receiving a large wood supply and with processes which store wood permanently. We encourage others to work in these depositional zones to understand the physical and biological impacts of large wood export from river basins.
On the evolution of Atlantic Meridional Overturning Circulation Fingerprint and implications for decadal predictability in the North Atlantic
Authors: Zhang Jinting , Zhang Rong
Published: June 2015

It has been suggested previously that the Atlantic Meridional Overturning Circulation (AMOC) anomaly associated with changes in the North Atlantic Deep Water formation propagates southward with an advection speed north of 34°N. In this study, using Geophysical Fluid Dynamics Laboratory Coupled Model version 2.1 (GFDL CM2.1), we show that this slow southward propagation of the AMOC anomaly is crucial for the evolution and the enhanced decadal predictability of the AMOC fingerprint—the leading mode of upper ocean heat content (UOHC) in the extratropical North Atlantic. A positive AMOC anomaly in northern high latitudes leads to a convergence/divergence of the Atlantic meridional heat transport (MHT) anomaly in the subpolar/Gulf Stream region, thus warming in the subpolar gyre (SPG) and cooling in the Gulf Stream region after several years. Recent decadal prediction studies successfully predicted the observed warm shift in the SPG in the mid‐1990s. Our results here provide the physical mechanism for the enhanced decadal prediction skills in the SPG UOHC.
A quantitative assessment of the relationship between precipitation deficits and air temperature variations
Authors: He B. , Wang H. L. , Wang Q. F. , Di Z. H.
Published: June 2015

Previous studies have reported precipitation deficits related to temperature extremes. However, how and to what extent precipitation deficits affect surface air temperatures is still poorly understood. In this study, the relationship between precipitation deficits and surface temperatures was examined in China from 1960 to 2012 based on monthly temperature and precipitation records from 565 stations. Significant negative correlations were identified in each season, with the strongest relationships in the summer, indicating that higher temperatures usually accompanied water‐deficient conditions and lower temperatures usually accompanied wet conditions. The examination of the correlations based on 30 year moving windows suggested that the interaction between the two variables has declined over the past three decades. Further investigation indicated a higher impact of extreme dry conditions on temperature than that of extreme wet conditions. In addition, a new simple index (Dry Temperature Index, DTI) was developed and used to quantitatively describe the relationship between water deficits and air temperature variations. We tested and compared the DTI in the coldest month (January) and the hottest month (July) of the year, station by station. In both months, the number of stations with a DThighI ≥ 50% was greater than those with a DThighI < 50%, indicating that a greater proportion of higher temperatures occurred during dry conditions. Based on the results, we conclude that water deficits in China are usually correlated to high temperatures but not to low temperatures.
Haematopoiesis
Authors: Kumar Ritu , Evans Todd
Published: June 2015

Haematopoiesis generates a variety of distinct blood cell types from a common stem cell. Secreted signalling molecules called cytokines modulate the survival, proliferation and differentiation of all the blood cell lineages, mediated by defined sets of transcription factors. Haematopoiesis is also influenced by external cues such as oxygen concentration. Haematopoiesis is an ongoing process continuing throughout lifetime, although the location of stem cells, and the specific cell types derived from them, changes during embryonic, foetal and early postnatal development. In the adult, haematopoiesis occurs primarily in the bone marrow, in association with a supportive niche. Haematopoietic stem cells are derived from cells bipotential for blood and endothelial cells, or directly from specialised endothelium. Blood lineages have a hierarchical relationship, but there is some flexibility among progenitors for deriving specific fates. Defects in haematopoiesis result in common and serious human diseases including anaemia and leukaemia.

Key Concepts

Haematopoiesis is the process of forming blood cells, which occurs during embryogenesis and throughout life.

Defects in haematopoiesis can result in some of the most common and serious human diseases, including anaemia and leukaemia.

Blood consists of many different kinds of cells with a diverse range of functions, controlling gaseous exchange and clotting and comprising the immune system.

All blood cells are derived from a common progenitor, the haematopoietic stem cell.

The sites where haematopoiesis occurs change during embryonic development, but in adult mammals, the bone marrow is the major site of haematopoiesis.

Haematopoietic stem cells in the bone marrow reside in a specialised microenvironment known as the haematopoietic stem cell niche, composed of osteoblasts, mesenchymal cells and sinusoidal vessels.

Growth factors called cytokines control the survival, self‐renewal and differentiation of haematopoietic stem cells and their progeny.

Blood cells have a close developmental relationship with endothelial cells, and haematopoietic stem cells appear to derive from ‘haemogenic endothelium’.

Haematopoiesis is also regulated by external factors. For example, hypoxia results in a compensatory increase in the number of erythrocytes.

Much effort is currently focused on generating and manipulating haematopoietic stem cells in vitro, to develop new regenerative therapies.
Ribosomal Proteins: Role in Ribosomal Functions
Authors: Nikolay Rainer , van den Bruck David , Achenbach John , Nierhaus Knud H
Published: June 2015

The assignment of specific ribosomal functions to individual ribosomal proteins is difficult due to the enormous cooperativity of the ribosome; however, important roles for distinct ribosomal proteins are becoming evident. Although ribosomal ribonucleic acid (rRNA) has the major claim to certain aspects of ribosome function, such as decoding and peptidyltransferase activity, there are also protein‐dominated functional hot‐spots on the ribosome such as the messenger RNA (mRNA) entry pore, the translation factor‐binding site and the exit of the ribosomal tunnel. The latter is binding site for both chaperones and complexes associated with protein transport through membranes. Furthermore, the contribution of ribosomal proteins is essential for the assembly and optimal functioning of the ribosome.

Key Concepts

A universal nomenclature for the ribosomal proteins was introduced in 2014, which terminates the babylonic chaos of the various nomenclature systems.

About two thirds of the bacterial ribosomal proteins have counterparts in archaeal and eukaryotic ribosomes.

Both rRNA and ribosomal proteins are essential for assembly, structure and function of the ribosomes.

A few ribosomal proteins are essential for the assembly, but lack a function in the mature ribosome.

In addition to rRNA‐dominated functional hot‐spots such as the decoding centre and the peptidyl‐transferase centre, there are also protein‐dominated functional hot‐spots such as the entry pore for the mRNA on the 30S subunit, the docking site for G‐protein factors and the exit of the tunnel harbouring the nascent peptide chain.
Xenopus
Embryo: Neural Induction
Authors: Pla Patrick , Monsoro‐Burq Anne‐Hélène
Published: June 2015

In embryos, the prospective nervous system forms during early development by a series of molecular events named neural induction. This includes the early action of mesoderm‐derived fibroblast growth factors (FGFs), followed by the blockade of bone morphogenetic protein (BMP) signalling by the dorsal mesoderm during gastrulation, and finally comprises the regionalisation of the neural plate along the anterior‐posterior and medial‐lateral axes, under the complex and combined actions of FGFs, retinoids and Wnts. Founding experiments using frog embryos have initiated intensive research on neural induction 90 years ago. Molecular approaches combined to classical experimental embryology strategies provide a powerful way of deciphering those complex regulations in frogs and more recently in other vertebrates. This article describes the current model of neural induction in the frog model system
Xenopus,
a model largely conserved between aquatic species and amniotes.

Key Concepts

The formation of neural precursors from the embryonic ectoderm is one of the earliest embryonic inductions.

Neural induction results in the formation of a neural plate regionalised along its anterior‐posterior and medial‐lateral axis.

Neural induction is subdivided into at least three steps: acquisition of neural competence, induction of anterior neural tissue, and posteriorisation of the neural tissue.

Almost a century after the discovery of the Spemann–Mangold organiser in frogs, the exploration of the molecular mechanisms driving neural induction remains a very active field of research.

The models and molecular mechanisms discovered in frogs are largely conserved in other vertebrates including amniotes.
T‐Lymphocyte Responses: Development
Authors: Cosmi Lorenzo , Liotta Francesco , Annunziato Francesco
Published: June 2015

CD4+ T cells can be subdivided from a functional point of view into two main subsets: effector cells, which provide protection against exogenous agents, and regulatory T (Treg) cells whose function is to avoid autoimmune reactions and to stop the effector response against exogenous antigens, when the response itself becomes dangerous for the host.

Human effector T helper (Th) lymphocytes can be additionally classified into lineages based mainly on their immunological functions that are supported by distinct profile of cytokine, transcription factor and homing receptor expression. Recently, beyond the well‐known Th1 and Th2 cells, other populations have been discovered. These include the Th17 subset, which is certainly the most intensively studied, but also Th22, Th9 and T follicular helper (Tfh) lymphocytes. T effector lymphocytes are not only responsible for different types of protective responses but also for the pathogenesis of many disorders.

Regarding Treg cells, there are two main categories, one emerging from the thymus as a population already planned to suppress the response against self antigens and another population which also emerges from the thymus, but acquires its suppressive activity in the periphery and is devoted to regulating the response towards non‐self antigens.

Key Concepts

CD4+ Th cells exist in two main functional subsets: effector cells that fight with exogenous agents and regulatory cells that protect from the damage induced by immune response.

Effector Th lymphocytes can be distinguished into three main phenotypes based on their immunological functions, the Th1, Th2 and Th17 subsets.

Cytokines produced by cells of innate immunity at the moment of the encounter of the naive Th cell with the specific antigen are crucial in the acquisitions of the different effector phenotypes.

T effector lymphocytes are also responsible for the pathogenesis of many disorders, Th1 and Th17 cells playing a role in chronic inflammatory diseases and Th2 cells in atopic diseases.

T regulatory cells provide protection from autoimmune phenomena and from the potential damage induced by persisting of the immune response.

T regulatory cells that achieve the regulatory phenotype in the thymus protect from self‐reactions, while the ones that acquire the regulatory properties in the periphery suppress the responses to exogenous antigens, when they may become dangerous for the host.
Human Genome Project, Personalised Medicine and Future Health Care
Authors: Tempini Niccolò , Leonelli Sabina
Published: June 2015

At the turn of the millennium, the Human Genome Project and the upcoming publication of the human genome sequence promised to open an entirely new approach to healthcare, based on the genotype of the individual. This approach was dubbed personalised medicine (PM). However, the analysis of sequencing results revealed that the complexity of the biological world had been underestimated. The major project of revolutionising medicine through genomics requires a more sophisticated and multilevel understanding of living systems, which in turn demands new data, models and modes of intervention on humans and non‐human organisms. Thus, the most advanced applications of PM involve a complex interweaving of biological and medical knowledge, as well as increasing attention to the technical systems through which data about any specific individual could be processed. Further, the development of PM needs to include consideration of several key ethical issues, ranging from privacy and data control to the risk that dependence on sophisticated technologies will widen the gap between haves and have‐nots both globally and within any one country.

Key Concepts

Personalised medicinedescribes the direction medical solutions are expected to evolve, towards personalisation and individual tailoring of therapies and treatment regimes that will cut and divide through patient populations. The motor of this promised innovation will be genomic profiling techniques, of nuclear DNA but also ones of latter development such as proteomics, metabolomics, transcriptomics and so on.

Biomedicineis an interdisciplinary space involving biological and medical knowledge/expertise as well as IT, where scientific knowledge about biological phenomena is mobilised in order to devise solutions to medical problems.

Data‐intensive sciencedescribes the mode of scientific research that is emerging as paramount in an age characterised by the increasing reliance and dependence of researchers on the development of complex, distributed infrastructures for data sharing and analysis.

Postgenomicsindicates efforts at creating and understanding models of life and disease that put genomic science and other biosciences at all levels of complexity in relation to each other.

Translational medicineindicates the fast‐developing domain of efforts and debate aimed at improving the translatability of discoveries and techniques from the lab into solutions, drugs and therapies that can be effectively implemented at the point of healthcare delivery.
Gamete Donation and ‘Race’
Authors: Hudson Nicky
Published: June 2015

Examining processes of gamete donation offers an opportunity to expose ideas about ‘race’ and examine perceptions about the racial substance that is ‘passed on’ from donor to offspring. Racial categories are of interest in the context of gamete donation because established ideas about the transmission of racial markers between generations and within racialised communities infuse the way in which donation is organised in clinical settings. The use and maintenance of these categories in donation practice has wider political implications because it reinscribes and re‐legitimises problematic and contested categories. This short article begins with an overview of the conceptual challenges associated with categorisations of race, considers the subsequent complexities of differentiating gamete donors in racial terms and concludes with a discussion of the implications of these debates for clinical practice, kinship relations and beyond.

Key Concepts

Ideas about the existence of discrete racial groups have been largely resigned to the history of scientific racism and colonialism.

Despite their contested nature, racial categories endure as a powerful visible signifier for relatedness and belonging in biological terms as well as carrying ideas about cultural and social relatedness, which are highly pertinent in understanding kinship.

Gamete donation, a form of assisted reproduction, offers a useful lens through which to expose ideas about race and examine perceptions about the racial substance that is ‘passed on’ from donor to offspring.

The ways people think about and select donors based on their racial or ethnic identities are often flexible and contingent and can therefore be at odds with commonly understood or clinically defined racial categories.

Whilst it is unlikely that racial categorisation will be omitted from use in assisted reproduction practices, we should remain cautious about the value that is attributed to such characteristics, particularly in relation to the growing globalised market in fertility treatment.