bluuebunny/crossref_metadata_2025 huggingface dataset:
Zugverankerung von gelenkig aufgelagerten Kranbahnträgern – Unerwartet hohe Ermüdungsbeanspruchung und verbesserte Detaillösung
Authors: Unterweger Harald , Taras Andreas , Kugler Paul
Published: April 2015

Kranbahnträger, die gelenkig auf Stützen aufgelagert sind, weisen häufig konstruktive Zugverankerungen gegen Abhebekräfte in Form von vertikalen Schrauben zwischen Trägeruntergurt und Stützenkopf auf. Bei Kranüberfahrt führt die vertikale Trägerdurchbiegung auch zu Auflagerverdrehungen. Die dadurch bedingten Relativverformungen zwischen Trägeruntergurt und Stützenkopfplatte führen zu außergewöhnlich hohen Zwängungsbeanspruchungen dieser Schrauben, wie anhand der FEM‐Analyse eines Beispiels dargestellt wird. Für die Abschätzung der Zwängungsbeanspruchung in den Schrauben wird ein einfaches Ingenieurmodell vorgestellt, das alle wesentlichen Parameter für die unterschiedlichen Ausführungsformen beinhaltet und am FEM‐Modell überprüft wurde. Abschließend werden erste Ansätze für eine verbesserte Detaillösung dargestellt.

Uplift fixing bolts in simply supported crane girders – unexpectedly high fatigue stresses and improved detailing solution. Crane girders with hinged supports on top of the columns are often fixed to the column head by placing vertical bolts between the girder’s lower flange and the column’s head plate, in order to prevent uplift of the girder. The passing of the crane load over the girder causes a deflection of the latter, which in turn leads to rotations of the girder end cross‐sections. The relative movements and rotations between the girder’s lower flange and the column’s head plate can lead to exceptionally large bending stresses in the fixing bolts, as is illustrated by means of a numerical (FEM) example in this paper. A simple engineering model, which is however capable of capturing all the relevant parameters for the different types of fixing detailing, is developed for the determination of these additional bending stresses and was verified by comparisons with the FEM models. Finally, proposals for an improved detailing solution are presented.
Die neue Straßenbrücke in Torun´, Polen – Teil 1: Planung und Bau
Authors: Wąchalski Krzysztof , Cywin´ski Zbigniew
Published: April 2015

Die neue Straßenbrücke Torun´ (deutsch: Thorn) wurde 2013 errichtet und ist heute die vierte Querung der Weichsel im Stadtgebiet – historisch aber ist sie die fünfte. Der vorliegende Beitrag stellt nach einem kurzen historischen Rückblick die Überbauten der Bogenbrücke vor – zwei Bögen mit 270 m Spannweite und 50 m Pfeilhöhe. Im ersten Teil werden der Entwurf und der Bau beschrieben sowie auf die kulturelle Bedeutung der Brücke eingegangen. Die theoretischen und experimentellen Nachweise sind Gegenstand von Teil 2, der in der nächsten Ausgabe dieser Zeitschrift publiziert werden wird.

Der Aufsatz ist dem unlängst verstorbenen Marek Sudak gewidmet, der neben dem erstgenannten Verfasser der zweite Hauptprojektant dieser Brücke war.

The new road bridge in Torun´, Poland – Part 1: design and construction. The new road bridge represents in modern times the fourth and historically already the fifth crossing of the river Vistula in Torun´ (Thorunium). Together with a short reference to the history of the city and its earlier constructed bridges, this paper shows the newest bridge – an arch bridge of 270 m span length and 50 m rise of both its superstructures. The first part contains details on the design and the construction, as well as the cultural background of the bridge. Part 2 presents the theoretical and experimental controls, which are competent for the bridge mounting and load test.

This contribution is devoted to the lately passed Marek Sudak, who was besides the first here mentioned author the second chief designer of that bridge.
Zur Biegebemessung von Flachdecken in Verbundbauweise
Authors: Schäfer Markus
Published: April 2015

Basierend auf den Forderungen nach schlanken Konstruktionen und einer Optimierung des Bauablaufs, gewinnt die Slim‐Floor‐Bauweise zunehmend an Bedeutung. Die Bemessung solcher Bauteile kann jedoch nicht allein auf Grundlage der Europäischen Regelwerke für den Verbundbau erfolgen. Es gelten einige Besonderheiten, die durch ergänzende Bemessungsregeln zu erfassen sind. An dieser Stelle wird die Aufmerksamkeit auf die Bemessung im Bauzustand, die Querschnittsklassifizierung und die Biegebemessung gelenkt. Neben den klassischen Querschnitten, bestehend aus gewalzten Profilen mit untergeschweißter Gurtplatte, werden dabei auch in die Decke integrierte hohlkastenartige Profilformen untersucht.

Determination of moment resistance for composite shallow‐floor beams – Additional design rules for slim‐floor beams. Due to the demand for sustainable buildings and slim constructions, composite slim‐floor systems become more important. The present European Codes do not include complete design rules for shallow‐floor beams. In the design, additional regulations have to be considered for ultimate limit state, serviceability limit state and fire design. In this paper the characteristics in erection state, for the cross section classification, the plastic moment resistance and the influence of transverse bending moments are presented. Apart from traditional sections consisting of rolled profiles also floor slabs with integrated steel box‐sections have been considered.
Development of a Fluorescent Reporter System to Delineate Cancer Stem Cells in Triple-Negative Breast Cancer
Authors: Thiagarajan Praveena S. , Hitomi Masahiro , Hale James S. , Alvarado Alvaro G. , Otvos Balint , Sinyuk Maksim , Stoltz Kevin , Wiechert Andrew , Mulkearns-Hubert Erin , Jarrar Awad M. , Zheng Qiao , Thomas Dustin , Egelhoff Thomas T. , Rich Jeremy N. , Liu Huiping , Lathia Justin D. , Reizes Ofer
Published: April 2015

Advanced cancers display cellular heterogeneity driven by self-renewing, tumorigenic cancer stem cells (CSCs). The use of cell lines to model CSCs is challenging due to the difficulty of identifying and isolating cell populations that possess differences in self-renewal and tumor initiation. To overcome these barriers in triple-negative breast cancer (TNBC), we developed a CSC system using a green fluorescent protein (GFP) reporter for the promoter of the well-established pluripotency gene NANOG. NANOG-GFP+ cells gave rise to both GFP+ and GFP− cells, and GFP+ cells possessed increased levels of the embryonic stem cell transcription factors NANOG, SOX2, and OCT4 and elevated self-renewal and tumor initiation capacities. GFP+ cells also expressed mesenchymal markers and demonstrated increased invasion. Compared with the well-established CSC markers CD24−/CD44+, CD49f, and aldehyde dehydrogenase (ALDH) activity, our NANOG-GFP reporter system demonstrated increased enrichment for CSCs. To explore the utility of this system as a screening platform, we performed a flow cytometry screen that confirmed increased CSC marker expression in the GFP+ population and identified new cell surface markers elevated in TNBC CSCs, including junctional adhesion molecule-A (JAM-A). JAM-A was highly expressed in GFP+ cells and patient-derived xenograft ALDH+ CSCs compared with the GFP− and ALDH− cells, respectively. Depletion of JAM-A compromised self-renewal, whereas JAM-A overexpression induced self-renewal in GFP− cells. Our data indicate that we have defined and developed a robust system to monitor differences between CSCs and non-CSCs in TNBC that can be used to identify CSC-specific targets for the development of future therapeutic strategies. Stem Cells. Stem Cells 2015;33:2114–2125
A Kindergartner's Emergent Strategy Use During Wordless Picture Book Reading
Authors: Lysaker Judith , Hopper Elizabeth
Published: April 2015

Decades of research in emergent reading demonstrate that children don't come to print reading as if it were a completely new activity. Emergent reading practices such as wordless book reading are often seen as precursors to the meaning making that comes later during print reading. Yet often, the specific strategies noted in children's emergent readings are seen as distinct, and not readily linked to those they will use later in more mature print reading. In this article, we examine the strategy use of one kindergartener as she engages in wordless book reading. Using Clay's overarching idea of monitoring and the related strategies of searching, cross‐checking, self‐correcting and rereading, we analyze children's wordless book readings for “print like” strategy use. We suggest that wordless book reading is an underutilized context for developing emergent comprehension prior to a focus on decoding.
Courage to Love
Authors: Wall Heather , Palmer Michelle
Published: April 2015

Instructional coaches continue to be an important part of school reform and professional development, and yet few studies have examined the impact of the language coaches use when working with teachers. The authors work to contribute towards filling this gap by describing a self‐;study examining their own language as instructional coaches and its impact on teachers. Paulo Freire's theories about dialogical interactions are used as a model framework. Freire outlined five conditions that must be in place to allow dialogue to occur: love, humility, faith in humankind, hope, and critical thinking. Each of these is examined regarding its impact on the coach‐teacher relationship and specific examples of situations from the self‐study are described. The authors describe how coaching dialogically can lead to greater teacher empowerment and stronger approaches to professional development.
Building Intercultural Understandings Through Global Literature
Authors: Martens Prisca , Martens Ray , Doyle Michelle Hassay , Loomis Jenna , Fuhrman Laura , Furnari Christie , Soper Elizabeth , Stout Robbie
Published: April 2015

In this article the authors share how they use global literature picturebooks with pre‐kindergarten, kindergarten, and first grade children in the context of A Curriculum That is International to develop the children's intercultural understandings. The picturebooks, shared through read alouds, individual and partner reading, and browsing, is focused particularly on children's personal identities as cultural beings and their identifying issues for which they take action to make the world a better place. In addition, the illustrations are discussed to develop the children's understandings of creating meaning through art. The authors argue that by through experiences with global literature children develop richer understandings of themselves as complex cultural beings and a perception of themselves as capable problem‐solvers who identify issues and take action to solve them.
Re: Maternal venous Doppler characteristics are abnormal in pre‐eclampsia but not in gestational hypertension. W. Gyselaers, A. Staelens, T. Mesens, K. Tomsin, J. Oben, S. Vonck, L. Verresen and G. Molenberghs. Ultrasound Obstet Gynecol 2015; 45: 421–426
Authors: Duvekot J. J.
Published: April 2015

Linked Comment: Ultrasound Obstet Gynecol 2015; 45: 421–426
Re: Diagnosis of fetal submicroscopic chromosomal abnormalities in failed array CGH samples: copy number by sequencing as an alternative to microarrays for invasive fetal testing. K. Cohen, A. Tzika, H. Wood, S. Berri, P. Roberts, G. Mason and E. Sheridan. Ultrasound Obstet Gynecol 2015; 45: 394–401
Authors: McMullan D. J.
Published: April 2015

Linked Comment: Ultrasound Obstet Gynecol 2015; 45: 394–401
Serum free β‐human chorionic gonadotropin in the three trimesters of pregnancy: effects of maternal characteristics and medical history
Authors: Wright D. , Papadopoulos S. , Silva M. , Wright A. , Nicolaides K. H.
Published: April 2015

Objective

To define the contribution of maternal variables which influence the measured level of maternal serum free β‐human chorionic gonadotropin (β‐hCG) in screening for pregnancy complications.

Methods

Maternal characteristics and medical history were recorded and serum free β‐hCG was measured in women with a singleton pregnancy attending for three routine hospital visits at 11 + 0 to 13 + 6, 19 + 0 to 24 + 6 and 30 + 0 to 34 + 6 weeks' gestation. For pregnancies delivering phenotypically normal live births or stillbirths ≥ 24 weeks' gestation, variables from maternal demographic characteristics and medical history that are important in the prediction of free β‐hCG were determined from a linear mixed‐effects multiple regression.

Results

Serum free β‐hCG was measured in 94 985 cases in the first trimester, 7879 in the second trimester and 8424 in the third trimester. Significant independent contributions to serum free β‐hCG were provided by gestational age, maternal weight, age and racial origin, cigarette smoking, method of conception, diabetes mellitus and family history of pre‐eclampsia (PE) in the mother of the patient. The effects of some variables were similar and those for others differed in each trimester. Random‐effects multiple regression analysis was used to define the contribution of maternal variables that influence the measured level of serum free β‐hCG and express the values as multiples of the median (MoMs). The model was shown to provide an adequate fit of MoM values for all covariates both in pregnancies that developed PE and in those without this pregnancy complication.

Conclusions

A model was fitted to express measured serum free β‐hCG across the three trimesters of pregnancy as MoMs after adjusting for variables from maternal characteristics and medical history that affect this measurement. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Serum pregnancy‐associated plasma protein‐A in the three trimesters of pregnancy: effects of maternal characteristics and medical history
Authors: Wright D. , Silva M. , Papadopoulos S. , Wright A. , Nicolaides K. H.
Published: April 2015

Objective

To define the contribution of maternal variables which influence the measured level of maternal serum pregnancy‐associated plasma protein‐A (PAPP‐A) in screening for pregnancy complications.

Methods

Maternal characteristics and medical history were recorded and serum PAPP‐A was measured in women with a singleton pregnancy attending for three routine hospital visits at 11 + 0 to 13 + 6, 19 + 0 to 24 + 6 and 30 + 0 to 34 + 6 weeks' gestation. For pregnancies delivering phenotypically normal live births or stillbirths ≥ 24 weeks' gestation, variables from maternal demographic characteristics and medical history that are important in the prediction of PAPP‐A were determined from a linear mixed‐effects multiple regression.

Results

Serum PAPP‐A was measured in 94 966 cases in the first trimester, 7785 in the second trimester and 8286 in the third trimester. Significant independent contributions to serum PAPP‐A were provided by gestational age, maternal weight, height, racial origin, cigarette smoking, diabetes mellitus, method of conception, previous pregnancy with or without pre‐eclampsia (PE) and birth‐weight Z‐score of the neonate in the previous pregnancy. The effects of some variables were similar and those for others differed in the three different trimesters. Random‐effects multiple regression analysis was used to define the contribution of maternal variables that influence the measured level of serum PAPP‐A and express the values as multiples of the median (MoMs). The model was shown to provide an adequate fit of MoM values for all covariates, both in pregnancies that developed PE and in those without this pregnancy complication.

Conclusions

A model was fitted to express the measured serum PAPP‐A across the three trimesters of pregnancy as MoMs, after adjusting for variables from maternal characteristics and medical history that affect this measurement. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
PSF: nuclear busy‐body or nuclear facilitator?
Authors: Yarosh Christopher A. , Iacona Joseph R. , Lutz Carol S. , Lynch Kristen W.
Published: April 2015

PTB‐associated splicing factor (PSF) is an abundant and essential nucleic acid‐binding protein that participates in a wide range of gene regulatory processes and cellular response pathways. At the protein level, PSF consists of multiple domains, many of which remain poorly characterized. Although grouped in a family with the proteins p54nrb/NONO and PSPC1 based on sequence homology, PSF contains additional protein sequence not included in other family members. Consistently, PSF has also been implicated in functions not ascribed to p54nrb/NONO or PSPC1. Here, we provide a review of the cellular activities in which PSF has been implicated and what is known regarding the mechanisms by which PSF functions in each case. We propose that the complex domain arrangement of PSF allows for its diversity of function and integration of activities. Finally, we discuss recent evidence that individual activities of PSF can be regulated independently from one another through the activity of domain‐specific co‐factors. WIREs RNA 2015, 6:351–367. doi: 10.1002/wrna.1280

This article is categorized under:

RNA Processing > Splicing Regulation/Alternative Splicing

RNA Processing > 3' End Processing
Simplified homogenization technique for engineering applications
Authors: Bäcker Dennis
Published: April 2015

Adapted from the parallel and series connections of materials a homogenization method for the calculation of effective material constants of composite materials is derived. A complex structure is divided into small volumes and each volume represents a different material. Thereby the volume fraction of complex‐formed inclusions can be approximated. Then, considering the position of volumes to each other (parallel / series connection) the effective material constants for elastic and piezoelectric materials are calculated.
Blow up threshold for the Gross‐Pitaevskii system with trapped dipolar quantum gases
Authors: Liu Baiyu , Ma Li , Wang Jing
Published: April 2015

In this paper, we study the Gross‐Pitaevskii system with trapped dipolar quantum gases. We obtain both the stable regime and the unstable regime. Moreover, via a construction of cross minimization problem, the blow up threshold is established.
Finite element methods for the incompressible Stokes equations with variable viscosity
Authors: John Volker , Kaiser Kristine , Novo Julia
Published: April 2015

Finite element error estimates are derived for the incompressible Stokes equations with variable viscosity. The ratio of the supremum and the infimum of the viscosity appears in the error bounds. Numerical studies show that this ratio can be observed sometimes. However, often the numerical results show a weaker dependency on the viscosity.
Early adolescent temperament, parental monitoring, and substance use in Mexican‐origin adolescents
Authors: Clark D. Angus , Donnellan M. Brent , Robins Richard W. , Conger Rand D.
Published: April 2015

Previous studies suggest that temperamental dispositions are associated with substance use. However, most research supporting this association has relied on European American samples (Stautz & Cooper, 2013). We addressed this gap by evaluating the prospective relations between 5th grade temperament and 9th grade substance use in a longitudinal sample of Mexican‐origin youth (N = 674). Effortful control and trait aggressiveness predicted 9th grade substance use, intentions, and expectations, even after controlling for 5th grade substance use. Additionally, we found an interaction between temperament and parental monitoring such that monitoring is a protective factor for early substance use primarily for youth with temperamental tendencies associated with risk for substance use (e.g., low effortful control and aggression). Results add to the growing literature demonstrating that early manifestations of self‐control are related to consequential life outcomes.
Culturally Inclusive Curriculum in Higher Education
Authors: Pridham Bruce , Martin Dona , Walker Kym , Rosengren Rosie , Wadley Danielle
Published: April 2015

The Australian National Program Standards for Teacher Education prioritises knowledge of culturally inclusive practices and challenges the educational community to present research on well-structured, inclusive, cross-curricula education partnerships. This article meets this challenge as it explores a core unit of work for undergraduate teachers with Indigenous education as its foundation. Most importantly, the paper presented here provides an overview of how to develop culturally appropriate pedagogical practice through culturally inclusive curriculum. Both the unit of work and the paper are built on the principles of Constructive Alignment. In engaging with the article, the reader will use the 4Rs of reflection, as used by the pre-service teachers within the unit of work, to personally engage with curriculum conversations. This engagement demonstrates excellence in education design and offers clear alignment with the Australian Curriculum Studies Association's (ACSA’s) principles for Australian curriculum.
ACHAEMENID ELITE CAVALRY: FROM XERXES TO DARIUS III
Authors: Charles Michael B.
Published: April 2015

A proper understanding of any military establishment is predicated on a sound understanding of the distinctions of its various components, including the relationship of elite units to those of lesser standing. The infantry of Achaemenid Persia has been given increased attention in recent years, especially in my three recent articles on (a) the permanent Achaemenid infantry, these being the 10,000 so-called Immortals (ἀθάνατοι) and the 1,000 Apple Bearers (μηλοφόροι), (b) the κάρδακες, whom I identified as a kind of general-purpose infantry of indeterminate ethnicity, and (c) the defensive equipment of Achaemenid infantry. In these articles, the Persian cavalry, orasabārain Old Persian, was mentioned in passing, yet a thorough appraisal of elite Achaemenid cavalry is still required. For example, in his overview of Xerxes' army, Barkworth pays particular attention to the elite infantry, but the cavalry is mentioned only in passing, while Shabazi, in his entry on the Achaemenid army orspāda, does not mention elite cavalry at all. In a recent important study, Tuplin looked carefully at the evidence for Achaemenid cavalry and the degree of importance attached to cavalry among the Persians, but only mentioned what might be termed elite cavalry twice – he did not offer any in-depth commentary on their relationship to other cavalry units.
GIVEN TO A DEITY? RELIGIOUS AND SOCIAL REAPPRAISAL OF HUMAN CONSECRATIONS IN THE HELLENISTIC AND ROMAN EAST
Authors: Caneva Stefano G. , Pizzi Aurian Delli
Published: April 2015

The adjective ἱερός is a central term in Greek religion and is used in various contexts. Generally translated ‘sacred’, it indicates that an object has been conceded to the gods and is now in relation with them (relation of belonging, protection, etc.). It appears frequently in Greek inscriptions in the expression τὰ ἱερά, to designate sacred objects or, in a more abstract meaning, sacred matters.
ΩΣΠΕΡ ΟΙ ΚΟΡYΒΑΝΤΙΩΝΤΕΣ: THE CORYBANTIC RITES IN PLATO'S DIALOGUES
Authors: Wasmuth Ellisif
Published: April 2015

Plato makes explicit references to Corybantic rites in six of his dialogues, spanning from the so-called earlyCritoto the laterLaws. In all but one of these an analogy is established between aspects of the Corybantic rites and some kind of λόγος: the words of the poets in theIon, Lysias' speech in thePhaedrus, and the arguments of Euthydemus and Dionysodorus, the personified Laws and Socrates in theEuthydemus,CritoandSymposiumrespectively. Plato's use of Corybantic analogies is thus quite extensive. Indeed, according to Ivan M. Linforth, whose 1946 article is still the most rigorous treatment of our sources on Corybantic rites in classical Athens, Plato is our ‘principal witness concerning Corybantic rites and their function’.
Police Misconduct and Political Legitimacy in Central America
Authors: CRUZ JOSÉ MIGUEL
Published: April 2015

What is the political impact of police corruption and abuse? From the literature, we know that police misconduct destroys people's confidence in police forces and hampers public collaboration with the criminal-justice system; but, what about the political regime, especially in countries striving for democratic governance? Does police wrongdoing affect the legitimacy of the overall regime? Focusing on Central America, this article provides empirical evidence showing that corruption and abuse perpetrated by police officers erode public support for the political order. Results indicate that, under some circumstances, police transgressions can have a greater impact on the legitimacy of the political system than crime or insecurity. They also show that police misconduct not only affects democratising regimes, such as El Salvador and Guatemala, but also consolidated democracies, such as Costa Rica.
MULTIVARIATE AR SYSTEMS AND MIXED FREQUENCY DATA: G-IDENTIFIABILITY AND ESTIMATION
Authors: Anderson Brian D.O. , Deistler Manfred , Felsenstein Elisabeth , Funovits Bernd , Koelbl Lukas , Zamani Mohsen
Published: April 2015

This paper is concerned with the problem of identifiability of the parameters of a high frequency multivariate autoregressive model from mixed frequency time series data. We demonstrate identifiability for generic parameter values using the population second moments of the observations. In addition we display a constructive algorithm for the parameter values and establish the continuity of the mapping attaching the high frequency parameters to these population second moments. These structural results are obtained using two alternative tools viz. extended Yule Walker equations and blocking of the output process. The cases of stock and flow variables, as well as of general linear transformations of high frequency data, are treated. Finally, we briefly discuss how our constructive identifiability results can be used for parameter estimation based on the sample second moments.
Restriction results for multilinear multipliers in weighted settings
Authors: Rodríguez-López Salvador
Published: April 2015

We obtain restriction results of de Leeuw’s type for maximal operators defined through multilinear Fourier multipliers of either strong or weak type acting on weighted Lebesgue spaces. We give some applications of our development. In particular, we obtain periodic weighted results for Coifman–Meyer-, Hörmander- and Hörmander–Mihlin-type multilinear multipliers.
Existence and uniqueness of positive solutions of nonlinear Schrödinger systems
Authors: Liu Haidong , Liu Zhaoli , Chang Jinyong
Published: April 2015

We prove that the Schrödinger system

where n = 1, 2, 3, N ≥ 2, λ1 = λ2 = … = λN = 1, βij = βji > 0 for i, j = 1, …, N, has a unique positive solution up to translation if the βij (i ≠ j) are comparatively large with respect to the βjj. The same conclusion holds if n = 1 and if the βij (i ≠ j) are comparatively small with respect to the βjj. Moreover, this solution is a ground state in the sense that it has the least energy among all non-zero solutions provided that the βij (i ≠ j) are comparatively large with respect to the βjj, and it has the least energy among all non-trivial solutions provided that n = 1 and the βij (i ≠ j) are comparatively small with respect to the βjj. In particular, these conclusions hold if βij = (i ≠ j) for some β and either β > max{β11, β22, …, βNN} or n = 1 and 0 < β < min{β11, β22, …, βNN}.
Global attractivity and extinction for Lotka–Volterra systems with infinite delay and feedback controls
Authors: Faria Teresa , Muroya Yoshiaki
Published: April 2015

The paper deals with a multiple species Lotka–Volterra model with infinite distributed delays and feedback controls, for which we assume a weak form of diagonal dominance of the instantaneous negative intra-specific terms over the infinite delay effect in both the population variables and controls. General sufficient conditions for the existence and attractivity of a saturated equilibrium are established. When the saturated equilibrium is on the boundary of , sharper criteria for the extinction of all or part of the populations are given. While the literature usually treats the case of competitive systems only, here no restrictions on the signs of the intra- and inter-specific delayed terms are imposed. Moreover, our technique does not require the construction of Lyapunov functionals.
Positive solutions for a class of quasilinear problems with critical growth in ℝN
Authors: Wang Jun , An Tianqing , Zhang Fubao
Published: April 2015

In this paper, we study the existence, multiplicity and concentration of positive solutions for a class of quasilinear problems

where —Δp is the p-Laplacian operator for is a small parameter, f(u) is a superlinear and subcritical nonlinearity that is continuous in u. Using a variational method, we first prove that for sufficiently small ε > 0 the system has a positive ground state solution uε with some concentration phenomena as ε → 0. Then, by the minimax theorems and Ljusternik–Schnirelmann theory, we investigate the relation between the number of positive solutions and the topology of the set of the global minima of the potentials. Finally, we obtain some sufficient conditions for the non-existence of ground state solutions.
Teaching with SimCity: Using Sophisticated Gaming Simulations to Teach Concepts in Introductory American Government
Authors: Woessner Matthew
Published: April 2015

One of the key challenges of teaching a college survey course such as introductory American government is the lack of interest on the part of students, many of whom take the course to satisfy a general-education requirement. Recognizing that young people are fascinated by video games, the author devised a governance simulation built on the popular computer game SimCity. Although the video-game industry designed these sophisticated simulations to be played by a single participant rather than a large group, the author created a simple set of rules that allows students to run them collectively. This article examines five factors for which an instructor must account if games such as SimCity are to have educational value. The author argues that, if conducted properly, this type of in-class exercise provides a fun and interesting way to teach students about the inherent challenges of governing in a democracy.
Social Science Mechanics: A Graduate Training Module that “Looks under the Hood” at Innovative Research Designs
Authors: Cahill Katie A. , Brownstein Michael R. , Burke Amanda E. , Kulesza Christopher , McCann James A.
Published: April 2015

Scholars in the fields of instructional development and pedagogy note that learning outcomes can be improved when teachers use “narratives” to communicate how complex processes work or how problems are addressed. In this article, the authors describe a narrative-centered approach to graduate-level instruction in research methodology. This approach is intended to supplement, not replace, conventional graduate seminars in quantitative or qualitative methods. In a series of lectures, scholars reflected on how their published articles originally were framed, the trade-offs that were necessary to advance the investigation, the methodological challenges and non-findings that had to be addressed—but may not have been printed—and the evolution of a piece as it progressed through the peer-review stages. This approach to exposing graduate students to the entirety of the research process is termedSocial Science Mechanics: A Look under the Hood at Innovative Research Designs. Surveys used to evaluate the series confirmed that graduate students who attended the presentations found them to be highly engaging and beneficial. Many faculty members also attended and found the lectures to be equally instructive.
Turning Introductory Comparative Politics and Elections Courses into Social Science Research Communities Using Wikipedia: Improving Both Teaching and Research
Authors: Kennedy Ryan , Forbush Eric , Keegan Brian , Lazer David
Published: April 2015

This article advocates a lesson plan for introductory comparative politics and elections courses. The authors argue that Wikipedia (yes, Wikipedia) provides a unique platform for improving learning outcomes and a useful social good from traditional student papers on elections. The proposed lesson plan can achieve this in at least three ways: (1) by providing social incentives for learning and a method for students to contribute to social science knowledge from their earliest courses, the incorporation of Wikipedia editing can improve student learning and retention; (2) incorporating an online information component can help both future students and researchers by improving the quality and quantity of easily accessible and well-referenced information about historical and upcoming elections; and (3) the use of the Wiki format is becoming increasingly common in both business and government. Teaching the basics of editing is an increasingly useful skill for students to learn for future employment.
The Internationalisation of the Academy: Convergence and Divergence across Disciplines
Authors: Rostan Michele , Antonio Ceravolo Flavio
Published: April 2015

The internationalisation of the academy varies according to individual, institutional and structural characteristics. Among factors influencing it, discipline plays a major role. Relying on data collected by two international comparative studies – the Changing Academic Profession Study and the Academic Profession in Europe Study – this article focuses on two aspects of the internationalisation of the academy – namely, international research collaboration and international mobility – asking whether these two aspects are associated with academic disciplines and how. Results from multivariate data analyses – comparing Europe and the Rest of the World or other meaningful macro-regions – show that in some areas, such as international research collaboration and educational circulation, the international behaviours of academics belonging to different disciplines diverge, while in some others, such as research productivity related to international research collaboration and short-term professional circulation, they converge.
Dynamics of Academic Mobility: Hegemonic Internationalisation or Fluid Globalisation
Authors: Scott Peter
Published: April 2015

Two broad frameworks are used to describe and analyse the mobility of academic staff. The first, and dominant, framework focuses on flows from the ‘periphery’ to the ‘core’, although that ‘core’ is also evolving (and is no longer dominated by North America and Western Europe but is increasingly likely to embrace dynamic East Asia systems). This first approach is labelled ‘hegemonic internationalisation’. The second framework focuses instead on issues of development, the emergence of global communities and social movements. This is labelled ‘fluid globalisation’. The article argues that the latter may be more useful for understanding trends in academic mobility.
International Academic Mobility: Towards a Concentration of the Minds in Europe
Authors: Van Der Wende Marijk
Published: April 2015

International mobility of academics has risen over the last few decades, especially among PhD students and post-docs. This may be the result of deliberate policies to stimulate such mobility on the one hand and of growing imbalances in academic career opportunities on the other. The general belief that attracting international talents helps to ensure that a country plays a leading role in research and innovation, stimulates countries to develop initiatives to attract international students to doctoral programmes or to attract researchers who emigrated back to the country of origin. More traditional intercontinental mobility patterns from the south to the north and the east to the west, are now paralleled within Europe, where the disparities between countries in terms of R&D investment and skills shortages increase, related to the economic crisis. Consequently, brain circulation may easily turn into brain drain, and cultural diversity may decline. Related policy questions are whether this will unavoidably result in a (further) concentration of the minds in a limited number of regions or hubs and how this should be considered from the point of view of quality, competitiveness, diversity, and the future of the comprehensive research university in Europe.
Negative feedback loop between p66Shc and ZEB1 regulates fibrotic EMT response in lung cancer cells
Authors: Li X , Gao D , Wang H , Li X , Yang J , Yan X , Liu Z , Ma Z
Published: April 2015

The epithelial-to-mesenchymal transition (EMT) program is crucial for the epithelial cancer progression and fibrotic diseases. Our previous work has demonstrated that p66Shc, a focal adhesion-associated adaptor protein, is frequently downregulated in lung cancers and its depletion promotes metastasis behavior through anoikis resistance. However, mechanism underlying loss of p66Shc and EMT response is not fully understood. Here, we showed that p66Shc deficiency enhanced the expression of ZEB1, the known mesenchymal transcription factor and consequently increased Vimentin, and decreased epithelial markers of E-cadherin and β-catenin. p66Shc depletion also increased cell invasion and migration. In addition, ChIP and luciferase assays showed that these effects were directly mediated by ZEB1 repression of p66Shc promoter. Thus, our findings define a critical role of p66Shc in the suppression of fibrotic EMT response with a negative feedback loop between p66Shc and ZEB1 in lung epithelial cancer cells.
Reduced mtDNA copy number increases the sensitivity of tumor cells to chemotherapeutic drugs
Authors: Mei H , Sun S , Bai Y , Chen Y , Chai R , Li H
Published: April 2015

Many cancer drugs are toxic to cells by activating apoptotic pathways. Previous studies have shown that mitochondria have key roles in apoptosis in mammalian cells, but the role of mitochondrial DNA (mtDNA) copy number variation in the pathogenesis of tumor cell apoptosis remains largely unknown. We used the HEp-2, HNE2, and A549 tumor cell lines to explore the relationship between mtDNA copy number variation and cell apoptosis. We first induced apoptosis in three tumor cell lines and one normal adult human skin fibroblast cell line (HSF) with cisplatin (DDP) or doxorubicin (DOX) treatment and found that the mtDNA copy number significantly increased in apoptotic tumor cells, but not in HSF cells. We then downregulated the mtDNA copy number by transfection with shRNA-TFAM plasmids or treatment with ethidium bromide and found that the sensitivity of tumor cells to DDP or DOX was significantly increased. Furthermore, we observed that levels of reactive oxygen species (ROS) increased significantly in tumor cells with lower mtDNA copy numbers, and this might be related to a low level of antioxidant gene expression. Finally, we rescued the increase of ROS in tumor cells with lipoic acid or N-acetyl-L-cysteine and found that the apoptosis rate decreased. Our studies suggest that the increase of mtDNA copy number is a self-protective mechanism of tumor cells to prevent apoptosis and that reduced mtDNA copy number increases ROS levels in tumor cells, increases the tumor cells’ sensitivity to chemotherapeutic drugs, and increases the rate of apoptosis. This research provides evidence that mtDNA copy number variation might be a promising new therapeutic target for the clinical treatment of tumors.
Pseudocapacitance of MXene nanosheets for high-power sodium-ion hybrid capacitors
Authors: Wang Xianfen , Kajiyama Satoshi , Iinuma Hiroki , Hosono Eiji , Oro Shinji , Moriguchi Isamu , Okubo Masashi , Yamada Atsuo
Published: April 2015

High-power Na-ion batteries have tremendous potential in various large-scale applications. However, conventional charge storage through ion intercalation or double-layer formation cannot satisfy the requirements of such applications owing to the slow kinetics of ion intercalation and the small capacitance of the double layer. The present work demonstrates that the pseudocapacitance of the nanosheet compound MXene Ti2C achieves a higher specific capacity relative to double-layer capacitor electrodes and a higher rate capability relative to ion intercalation electrodes. By utilizing the pseudocapacitance as a negative electrode, the prototype Na-ion full cell consisting of an alluaudite Na2Fe2(SO4)3 positive electrode and an MXene Ti2C negative electrode operates at a relatively high voltage of 2.4 V and delivers 90 and 40 mAh g−1 at 1.0 and 5.0 A g−1 (based on the weight of the negative electrode), respectively, which are not attainable by conventional electrochemical energy storage systems.
Ptch1 and Gli regulate Shh signalling dynamics via multiple mechanisms
Authors: Cohen Michael , Kicheva Anna , Ribeiro Ana , Blassberg Robert , Page Karen M. , Barnes Chris P. , Briscoe James
Published: April 2015

In the vertebrate neural tube, the morphogen Sonic Hedgehog (Shh) establishes a characteristic pattern of gene expression. Here we quantify the Shh gradient in the developing mouse neural tube and show that while the amplitude of the gradient increases over time, the activity of the pathway transcriptional effectors, Gli proteins, initially increases but later decreases. Computational analysis of the pathway suggests three mechanisms that could contribute to this adaptation: transcriptional upregulation of the inhibitory receptor Ptch1, transcriptional downregulation of Gli and the differential stability of active and inactive Gli isoforms. Consistent with this, Gli2 protein expression is downregulated during neural tube patterning and adaptation continues when the pathway is stimulated downstream of Ptch1. Moreover, the Shh-induced upregulation of Gli2 transcription prevents Gli activity levels from adapting in a different cell type, NIH3T3 fibroblasts, despite the upregulation of Ptch1. Multiple mechanisms therefore contribute to the intracellular dynamics of Shh signalling, resulting in different signalling dynamics in different cell types.
Selective enhancement of topologically induced interface states in a dielectric resonator chain
Authors: Poli Charles , Bellec Matthieu , Kuhl Ulrich , Mortessagne Fabrice , Schomerus Henning
Published: April 2015

The recent realization of topological phases in insulators and superconductors has advanced the search for robust quantum technologies. The prospect to implement the underlying topological features controllably has given incentive to explore optical platforms for analogous realizations. Here we realize a topologically induced defect state in a chain of dielectric microwave resonators and show that the functionality of the system can be enhanced by supplementing topological protection with non-hermitian symmetries that do not have an electronic counterpart. We draw on a characteristic topological feature of the defect state, namely, that it breaks a sublattice symmetry. This isolates the state from losses that respect parity-time symmetry, which enhances its visibility relative to all other states both in the frequency and in the time domain. This mode selection mechanism naturally carries over to a wide range of topological and parity-time symmetric optical platforms, including couplers, rectifiers and lasers.
Demonstration of entanglement-enhanced phase estimation in solid
Authors: Liu Gang-Qin , Zhang Yu-Ran , Chang Yan-Chun , Yue Jie-Dong , Fan Heng , Pan Xin-Yu
Published: April 2015

Precise parameter estimation plays a central role in science and technology. The statistical error in estimation can be decreased by repeating measurement, leading to that the resultant uncertainty of the estimated parameter is proportional to the square root of the number of repetitions in accordance with the central limit theorem. Quantum parameter estimation, an emerging field of quantum technology, aims to use quantum resources to yield higher statistical precision than classical approaches. Here we report the first room-temperature implementation of entanglement-enhanced phase estimation in a solid-state system: the nitrogen-vacancy centre in pure diamond. We demonstrate a super-resolving phase measurement with two entangled qubits of different physical realizations: an nitrogen-vacancy centre electron spin and a proximal 13C nuclear spin. The experimental data shows clearly the uncertainty reduction when entanglement resource is used, confirming the theoretical expectation. Our results represent an elemental demonstration of enhancement of quantum metrology against classical procedure.
Preference for concentric orientations in the mouse superior colliculus
Authors: Ahmadlou Mehran , Heimel J Alexander
Published: April 2015

The superior colliculus is a layered structure important for body- and gaze-orienting responses. Its superficial layer is, next to the lateral geniculate nucleus, the second major target of retinal ganglion axons and is retinotopically organized. Here we show that in the mouse there is also a precise organization of orientation preference. In columns perpendicular to the tectal surface, neurons respond to the same visual location and prefer gratings of the same orientation. Calcium imaging and extracellular recording revealed that the preferred grating varies with retinotopic location, and is oriented parallel to the concentric circle around the centre of vision through the receptive field. This implies that not all orientations are equally represented across the visual field. This makes the superior colliculus different from visual cortex and unsuitable for translation-invariant object recognition and suggests that visual stimuli might have different behavioural consequences depending on their retinotopic location.
Quantitating and Dating Recent Gene Flow between European and East Asian Populations
Authors: Qin Pengfei , Zhou Ying , Lou Haiyi , Lu Dongsheng , Yang Xiong , Wang Yuchen , Jin Li , Chung Yeun-Jun , Xu Shuhua
Published: April 2015

Historical records indicate that extensive cultural, commercial and technological interaction occurred between European and Asian populations. What have been the biological consequences of these contacts in terms of gene flow? We systematically estimated gene flow between Eurasian groups using genome-wide polymorphisms from 34 populations representing Europeans, East Asians and Central/South Asians. We identified recent gene flow between Europeans and Asians in most populations we studied, including East Asians and Northwestern Europeans, which are normally considered to be non-admixed populations. In addition we quantitatively estimated the extent of this gene flow using two statistical approaches and dated admixture events based on admixture linkage disequilibrium. Our results indicate that most genetic admixtures occurred between 2,400 and 310 years ago and show the admixture proportions to be highly correlated with geographic locations, with the highest admixture proportions observed in Central Asia and the lowest in East Asia and Northwestern Europe. Interestingly, we observed a North-to-South decline of European gene flow in East Asians, suggesting a northern path of European gene flow diffusing into East Asian populations. Our findings contribute to an improved understanding of the history of human migration and the evolutionary mechanisms that have shaped the genetic structure of populations in Eurasia.