bluuebunny/crossref_metadata_2025 huggingface dataset:
Biphasic water splitting by osmocene
Authors: Ge Peiyu , Todorova Tanya K. , Patir Imren Hatay , Olaya Astrid J. , Vrubel Heron , Mendez Manuel , Hu Xile , Corminboeuf Clémence , Girault Hubert H.
Published: June 2012

The photochemical reactivity of osmocene in a biphasic water-organic solvent system has been investigated to probe its water splitting properties. The photoreduction of aqueous protons to hydrogen under anaerobic conditions induced by osmocene dissolved in 1,2-dichloroethane and the subsequent water splitting by the osmocenium metal-metal dimer formed during H
2
production were studied by electrochemical methods, UV-visible spectrometry, gas chromatography, and nuclear magnetic resonance spectroscopy. Density functional theory computations were used to validate the reaction pathways.
Room temperature femtosecond X-ray diffraction of photosystem II microcrystals
Authors: Kern Jan , Alonso-Mori Roberto , Hellmich Julia , Tran Rosalie , Hattne Johan , Laksmono Hartawan , Glöckner Carina , Echols Nathaniel , Sierra Raymond G. , Sellberg Jonas , Lassalle-Kaiser Benedikt , Gildea Richard J. , Glatzel Pieter , Grosse-Kunstleve Ralf W. , Latimer Matthew J. , McQueen Trevor A. , DiFiore Dörte , Fry Alan R. , Messerschmidt Marc , Miahnahri Alan , Schafer Donald W. , Seibert M. Marvin , Sokaras Dimosthenis , Weng Tsu-Chien , Zwart Petrus H. , White William E. , Adams Paul D. , Bogan Michael J. , Boutet Sébastien , Williams Garth J. , Messinger Johannes , Sauter Nicholas K. , Zouni Athina , Bergmann Uwe , Yano Junko , Yachandra Vittal K.
Published: June 2012

Most of the dioxygen on earth is generated by the oxidation of water by photosystem II (PS II) using light from the sun. This light-driven, four-photon reaction is catalyzed by the Mn4CaO5cluster located at the lumenal side of PS II. Various X-ray studies have been carried out at cryogenic temperatures to understand the intermediate steps involved in the water oxidation mechanism. However, the necessity for collecting data at room temperature, especially for studying the transient steps during the O–O bond formation, requires the development of new methodologies. In this paper we report room temperature X-ray diffraction data of PS II microcrystals obtained using ultrashort (< 50 fs) 9 keV X-ray pulses from a hard X-ray free electron laser, namely the Linac Coherent Light Source. The results presented here demonstrate that the ”probe before destroy” approach using an X-ray free electron laser works even for the highly-sensitive Mn4CaO5cluster in PS II at room temperature. We show that these data are comparable to those obtained in synchrotron radiation studies as seen by the similarities in the overall structure of the helices, the protein subunits and the location of the various cofactors. This work is, therefore, an important step toward future studies for resolving the structure of the Mn4CaO5cluster without any damage at room temperature, and of the reaction intermediates of PS II during O–O bond formation.
Feedback regulation of plastidic acetyl-CoA carboxylase by 18:1-acyl carrier protein in
Brassica napus
Authors: Andre Carl , Haslam Richard P. , Shanklin John
Published: June 2012

Plant seed oil represents a major renewable source of reduced carbon, but little is known about the biochemical regulation of its synthesis. The goal of this research was to identify potential feedback regulation of fatty acid biosynthesis in
Brassica napus
embryo-derived cell cultures and to characterize both the feedback signals and enzymatic targets of the inhibition. Fatty acids delivered via Tween esters rapidly reduced the rate of fatty acid synthesis in a dose-dependent and reversible manner, demonstrating the existence of feedback inhibition in an oil-accumulating tissue. Tween feeding did not affect fatty acid elongation in the cytosol or the incorporation of radiolabeled malonate into nascent fatty acids, which together pinpoint plastidic acetyl-CoA carboxylase (ACCase) as the enzymatic target of feedback inhibition. To identify the signal responsible for feedback, a variety of Tween esters were tested for their effects on the rate of fatty acid synthesis. Maximum inhibition was achieved upon feeding oleic acid (18:1) Tween esters that resulted in the intracellular accumulation of 18:1 free fatty acid, 18:1-CoA, and 18:1-acyl-carrier protein (ACP). Direct, saturable inhibition of ACCase enzyme activity was observed in culture extracts and in extracts of developing canola seeds supplemented with 18:1-ACP at physiological concentrations. A mechanism for feedback inhibition is proposed in which reduced demand for de novo fatty acids results in the accumulation of 18:1-ACP, which directly inhibits plastidic ACCase, leading to reduced fatty acid synthesis. Defining this mechanism presents an opportunity for mitigating feedback inhibition of fatty acid synthesis in crop plants to increase oil yield.
Mosquitoes survive raindrop collisions by virtue of their low mass
Authors: Dickerson Andrew K. , Shankles Peter G. , Madhavan Nihar M. , Hu David L.
Published: June 2012

In the study of insect flight, adaptations to complex flight conditions such as wind and rain are poorly understood. Mosquitoes thrive in areas of high humidity and rainfall, in which raindrops can weigh more than 50 times a mosquito. In this combined experimental and theoretical study, we here show that free-flying mosquitoes can survive the high-speed impact of falling raindrops. High-speed videography of those impacts reveals a mechanism for survival: A mosquito’s strong exoskeleton and low mass renders it impervious to falling drops. The mosquito’s low mass causes raindrops to lose little momentum upon impact and so impart correspondingly low forces to the mosquitoes. Our findings demonstrate that small fliers are robust to in-flight perturbations.
Multiscale natural moves refine macromolecules using single-particle electron microscopy projection images
Authors: Zhang Junjie , Minary Peter , Levitt Michael
Published: June 2012

The method presented here refines molecular conformations directly against projections of single particles measured by electron microscopy. By optimizing the orientation of the projection at the same time as the conformation, the method is well-suited to two-dimensional class averages from cryoelectron microscopy. Such direct use of two-dimensional images circumvents the need for a three-dimensional density map, which may be difficult to reconstruct from projections due to structural heterogeneity or preferred orientations of the sample on the grid. Our refinement protocol exploits Natural Move Monte Carlo to model a macromolecule as a small number of segments connected by flexible loops, on multiple scales. After tests on artificial data from lysozyme, we applied the method to the
Methonococcus maripaludis chaperonin
. We successfully refined its conformation from a closed-state initial model to an open-state final model using just one class-averaged projection. We also used Natural Moves to iteratively refine against heterogeneous projection images of
Methonococcus maripaludis chaperonin
in a mix of open and closed states. Our results suggest a general method for electron microscopy refinement specially suited to macromolecules with significant conformational flexibility. The algorithm is available in the program Methodologies for Optimization and Sampling In Computational Studies.
Direct reciprocity in structured populations
Authors: van Veelen Matthijs , García Julián , Rand David G. , Nowak Martin A.
Published: June 2012

Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that “indirect invasions” remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies.
Semimetallic dense hydrogen above 260 GPa
Authors: Lebègue Sébastien , Araujo Carlos Moyses , Kim Duck Young , Ramzan Muhammad , Mao Ho-kwang , Ahuja Rajeev
Published: June 2012

Being the lightest and the most abundant element in the universe, hydrogen is fascinating to physicists. In particular, the conditions of its metallization associated with a possible superconducting state at high temperature have been a matter of much debate in the scientific community, and progress in this field is strongly correlated with the advancements in theoretical methods and experimental techniques. Recently, the existence of hydrogen in a metallic state was reported experimentally at room temperature under a pressure of 260–270 GPa, but was shortly after that disputed in the light of more experiments, finding either a semimetal or a transition to an other phase. With the aim to reconcile the different interpretations proposed, we propose by combining several computational techniques, such as density functional theory and the GW approximation, that phase III at ambient temperature of hydrogen is the
Cmca
-12 phase, which becomes a semimetal at 260 GPa . From phonon calculations, we demonstrate it to be dynamically stable; calculated electron–phonon coupling is rather weak and therefore this phase is not expected to be a high-temperature superconductor.
Enabling single-mode behavior over large areas with photonic Dirac cones
Authors: Bravo-Abad Jorge , Joannopoulos John D. , Soljačić Marin
Published: June 2012

Many of graphene’s unique electronic properties emerge from its Dirac-like electronic energy spectrum. Similarly, it is expected that a nanophotonic system featuring Dirac dispersion (two conical bands touching at a single point, the so-called Dirac point) will open a path to a number of important research avenues. To date, however, all proposed realizations of a photonic analog of graphene lack fully omnidirectional out-of-plane light confinement, which has prevented creating truly realistic implementations of this class of systems able to mimic the two-dimensional transport properties of graphene. Here we report on a novel route to achieve all-dielectric three-dimensional photonic materials featuring Dirac-like dispersion in a quasi-two-dimensional system. We further discuss how this finding could enable a dramatic enhancement of the spontaneous emission coupling efficiency (the β-factor) over large areas, defying the common wisdom that the β-factor degrades rapidly as the size of the system increases. These results might enable general new classes of large-area ultralow-threshold lasers, single-photon sources, quantum information processing devices and energy harvesting systems.
Y chromosome mediates ribosomal DNA silencing and modulates the chromatin state inDrosophila
Authors: Zhou Jun , Sackton Timothy B. , Martinsen Lene , Lemos Bernardo , Eickbush Thomas H. , Hartl Daniel L.
Published: June 2012

Although theDrosophilaY chromosome is degenerated, heterochromatic, and contains few genes, increasing evidence suggests that it plays an important role in regulating the expression of numerous autosomal and X-linked genes. Here we use 15 Y chromosomes originating from a single founder 550 generations ago to study the role of the Y chromosome in regulating rRNA gene transcription, position-effect variegation (PEV), and the link among rDNA copy number, global gene expression, and chromatin regulation. Based on patterns of rRNA gene transcription indicated by transcription of the retrotransposonR2that specifically inserts into the 28S rRNA gene, we show that X-linked rDNA is silenced in males. The silencing of X-linked rDNA expression by the Y chromosome is consistent across populations and independent of genetic background. These Y chromosomes also vary more than threefold in rDNA locus size and cause dramatically different levels of PEV suppression. The degree of suppression is negatively associated with the number and fraction of rDNA units without transposon insertions, but not with total rDNA locus size. Gene expression profiling revealed hundreds of differentially expressed genes among these Y chromosome introgression lines, as well as a divergent global gene expression pattern between the low-PEV and high-PEV flies. Our findings suggest that the Y chromosome is involved in diverse phenomena related to transcriptional regulation including X-linked rDNA silencing and suppression of PEV phenotype. These results further expand our understanding of the role of the Y chromosome in modulating global gene expression, and suggest a link with modifications of the chromatin state.
Abstracts as orientation tools in a modular electronic environment
Authors: van der Tol Maarten
Published: June 2012

In an electronic publication environment, a scienti¼c article can be structured more e¬ectively and e~ciently if it is presented as a coherent collection of well-characterized and explicitly linked modules, rather than as a traditional linear essay. In a linear printed article, the abstract primarily ful¼lls a selection and substitution function. In a network of modular electronic articles, the abstract is primarily an orientation tool providing insight into the ½ow of the discourse. In order to ful¼ll this function, the abstract must provide a balanced representation that explicitly refers, in the informative mode, to the main stages in the problem-solving process. The orientation can be facilitated by hypertext links that connect phrases of the abstract to the related modules, enabling the reader to switch smoothly between the abstract and its source text. Each link has to carry a label that informs the reader about the speci¼c relationship between the phrase at hand and the module referred to.
The problem-solving potential of text evaluation
Authors: Carstens Adelia
Published: June 2012

Examination papers have until now received little attention in the field of document design. Although this theoretical framework and the domain of application may not be a perfect match, the principles of document design could have some heuristic value in the domain of assessment in education. The poor results of a group of South African technical college students from certain cultural and educational backgrounds merited an investigation into the diagnostic and remedial value of these principles. In this contribution examination papers are situated within a general model for problem-based text evaluation, representative of current thinking in document design. At a more specic level criteria for assessment in education are identied and validated as criteria for examination papers in particular. These criteria are mapped onto the textual elements of documents and represented in an evaluation matrix. The applicability of the matrix is demonstrated through the analysis of a selection of examples from national examination papers for career-oriented college subjects. It is suggested that any pretesting - text-focused, expert-focused or reader-focused - be preceded by thorough planning, taking cognizance of the macro-context of problem-based document design, valid micro-contextual criteria, and appropriate research methods. The outcomes should yield useful dividends at a practical as well as an academic level.
The intercultural validity of customer-complaint handling routines
Authors: Shaw Philip
Published: June 2012

Handbooks and consultants offer guidelines for customer-complaint reception which seem quite uniform across cultures. But one would expect different behavior patterns in different cultures. This paper describes a pilot investigation of this paradox. Four complaint-handling dialogues exhibiting different levels and types of politeness were written and shown to business students of various European nationalities, predominantly Danish and Spanish. The results showed that the Danes were much less tolerant of polite phrases and promotional language than the Spaniards, but that there was a ’concise, brief, sincere’ style acceptable to all cultural-national groups.
What’s in a crisis?
Authors: Jacobs Geert
Published: June 2012

This paper explores some of the presuppositions that underlie the analytical practice in crisis communication studies. Drawing from a wide-ranging corpus of contributions to the field, it distinguishes seven ‘fundamentals’ or basic assumptions. Next, the paper argues that these fundamentals provide evidence of a homogenizing approach to crisis communication for which the label ‘reductionism’ is proposed. The third and final part indicates new directions for further research in the field.
Structure and topic information in expository text overviews
Authors: Dupont Vincent , Bestgen Yves
Published: June 2012

The current wisdom on texts is that they should start by providing readers with an overview of the content (the topics discussed) and the structure (the relationship between the topics). However, in a recent paper Murray and McGlone (1997) reported that readers benefit from topic information but not from structural information provided in an overview of a very simple text. In the present experiments we ask whether these observations would be applicable to more complex texts in which structural information would be more important. Two experiments, which used a text with a complex hierarchical structure, replicated previous results on reading times. The second experiment also permitted us to rule out the effect of numerical signals in the text as the reason for the results.
No limits to borrowing
Authors: Yeon-Ju Lee , Sagart Laurent
Published: June 2012

Based on the large amount of Chinese-related basic vocabulary in Bai, scholars like Benedict, Starostin and Zhengzhang have claimed a special phylogenetic proximity between Bai and Chinese. In this paper we show that the Chinese vocabulary in Bai is stratified, forming successive layers of borrowings. We identify three such layers, describing the sound correspondences which characterize each of them: two Mandarin layers, one local, one regional for modern words; and an early Chinese layer, acquired during a long and complex period of intimate contact between Bai and Chinese, beginning in Han times and terminating in Late Tang, altogether a millennium or so. This last layer is subdivided into several sub-layers. The remaining part of the vocabulary forms the Bai indigenous layer, whose affiliation is clearly Sino-Tibetan, without having any particular proximity to Chinese. In particular, the numerals “1” and “2” have etymological connections among non-Chinese Sino-Tibetan languages such as Jingpo, Sulung and Tangut. The numerals above “2” are Chinese loanwords and even the numerals “1” and “2” have less colloquial variants of Chinese origin. Bai is of interest to comparative linguistics for the extraordinary amount of basic vocabulary it has borrowed from Chinese, all of it during the early period: 47% of the 100-word Swadesh list.
Input filters in second language acquisition
Authors: Lightbown Patsy M.
Published: June 2012

This paper reviews a variety of restrictions (input filters) on the conversion of input to intake and thence to acquisition. These filters are internal characteristics of the learner which seem to interfere with the ability to make use of L2 input for acquisition, even when that input seems, on the surface, to be appropriate and plentiful. Three sorts of filters are examined: affective filters, auditory/phonological filters, and cognitive filters. In the third category, three kinds of cognitive filters are discussed: (a) overload or conflict in the processing systems, (b) developmental filters, and (c) effects of previously learned languages. The discussion focuses on the role of instruction and feedback in making input more accessible to classroom learners and guiding them to perceive the difference between interlanguage patterns and those of the target language.
Motivation and attitudes towards L2
Authors: Muñoz Carmen , Tragant Elsa
Published: June 2012

This paper analyses the answers to a questionnaire in which learners of different age-groups and different proficiency levels were asked about their attitudes and types of motivation towards the L2 (EFL). First, motivation is seen to increase with school experience. Second, the younger learners show more intrinsic types of motivation, while the older groups show more extrinsic types and a preference for an instrumental type of motivation. That is, while the younger students do not, as a group, present higher motivation than the older students, they have a qualitatively different type of motivation. Third, significant statistical relations are shown between attitude towards language learning and achievement in some language tests, but not all. Significant relations are also found between achievement at the first measurement time and attitudes at the second in those students who were traced longitudinally, raising the issue of the directionality of the relation between motivation and second language achievement.
Text organisation in Italian L2 learning varieties
Authors: Ferraris Stefania
Published: June 2012

Connecting expressions reveal how the speaker copes with text organisation; and studying aspects of the development of these forms in L2 varieties helps us throw light on both pragmatic and syntactic text organisation in interlanguages. Syntactically, linking markers are involved in the development of subordination; pragmatically, their presence gives a map of learners’ discourse articulation. The present investigation of Italian L2 interlanguages showed that simple clauses and coordination appear before subordination, and that subordinate clauses seem to develop from adverbial to complement and relative clauses. At the pragmatic level, connecting particles emerge in less developed interlanguages. The data presented here are relevant to theoretical research on subordination hierarchies (central vs. marginal forms) and those cognitive categories (time, cause, concession, etc.) which are more likely to be expressed syntactically and/or pragmatically.
Form–meaning connections in the acquisition of English articles
Authors: Trenkic Danijela
Published: June 2012

This paper examines the acquisition of English articles by native speakers of Serbian, a language which has no article system. Data from a translation task, performed by four proficiency groups are presented to demonstrate that, contrary to previous research, learners do not associate articles with either ‘hearer knowledge’ or ‘specificity of referent’ (Huebner 1983, Master 1990, Tarone and Parish 1989, Thomas 1989). Rather, they establish non-target form–meaning connections, where ‘the’ is associated with a discrete referent, and ‘a(n)’ with the individuation of non-discrete referents.
Communicative potential vs. structural constraints
Authors: Benazzo Sandra
Published: June 2012

This study investigates the acquisition of scope items such as ‘only’, ‘even’, ‘also’, ‘still’, ‘again’, ‘already’ etc. in the longitudinal data of untutored second language learners of English, French and German. These items are found to appear in a fixed sequence: additive/restrictive > iterative > contrastive, which correlates crosslinguistically with the development of learner varieties from a prebasic to a postbasic level. Analysis of the discourse behaviour of these particles suggests that while the communicative potential of these items justifies their early appearance, their use is constrained by the global organisation of learner varieties. In other words, appearance of particular items is constrained by the learner’s developmental stage.
Communicating in English as a lingua franca
Authors: House Juliane
Published: June 2012

This paper will first discuss the role of English as a lingua franca from historical and socio-political perspectives; it will then review some relevant findings of research into actual interactions conducted in English as a lingua franca (ELF), before describing a study of ELF interactions. It will be argued that we need a new research agenda to adequately describe and explain the hitherto unknown global spread of one particular language, and the wide variety of functions, domains, situations and populations it has come to involve.
On rule complexity
Authors: Dietz Gunther
Published: June 2012

It is widely acknowledged by second language researchers that whether pedagogical rules should or can be explicitly taught is largely dependent on their complexity. Nevertheless, there is no consensus on what rule complexity exactly means. This paper first examines existing accounts of rule complexity and presents a conceptual analysis of the term ‘rule’. It then proposes that ‘complex’ should not be equated with ‘difficult’, but used in a purely structural sense. Specifically a conditional formulation is proposed in which the number of concepts in the antecedent and the consequent, the number of subconditions, and the number of ‘if-then’ connections (subrules) within a given rule domain govern complexity. Finally, a classification of strategies of complexity reduction in foreign language pedagogy is sketched. Throughout, examples will be given from the field of German as a foreign language.
Cross-linguistic influence and acceptability judgments of L2 and L1 collocations
Authors: Leśniewska Justyna , Witalisz Ewa
Published: June 2012

The paper presents an investigation of the extent and nature of cross-linguistic influence on both L2 and L1 phraseological competence of advanced Polish learners of English. We review relevant research studies, which describe various types of collocational deviation from native speaker norms in the language production of advanced learners, and indicate that the collocational choices of learners may be affected by their L1, which results either in incorrect collocations, or in patterns of underuse or overuse.

 We administered two acceptability judgment tests to 91 Polish advanced learners of English, aged 20–22. The collocations used in the test could be classified with respect to two criteria: firstly, they were either typical or unusual collocations; secondly, they were either congruent with their L1 or L2 equivalents or not. Despite the fact that there is both empirical and theoretical support for the idea that learners may show a preference for those L2 collocations which are congruent with L1, our findings do not support this hypothesis. There is no obvious pattern of cross-linguistic influence emerging from the data. The results of this study seem to give the picture of advanced learners who function in their L2 independently of the L1.
Interpersonal modification in the English noun phrase
Authors: Van de Velde Freek
Published: June 2012

This article gives an overview of the various interpersonal modifiers in the English noun phrase, several of which seem to have been overlooked in formal as well as functional grammars. On the theoretical side, this article is concerned with how to bring the constructions at issue under a Functional Discourse Grammar representation (Hengeveld and Mackenzie 2006, in prep.).
Expressing the notion of purpose in English and Spanish instructions
Authors: Murcia-Bielsa Susana , Delin Judy
Published: June 2012

Using a corpus of written consumer product instructions in English and Spanish, this paper provides a comparative description of the type and frequency of expressions used to convey the notion of an action’s PURPOSE or its goal. Based on our own observations and suggestions from previous literature, we present eight factors relevant to the choice between purpose expressions in both languages: the semantic relation underlying the purpose expression, the scope of the expression, whether the purpose expression constrains how the action is performed, whether the goal of the action is a process or a product, whether the goal is contrastive with some other possible goal, whether the information status of the goal needs to be expressed, whether the agent of the action needs to be specified, and whether the goal is optional. These features are either involved in the choice of which expression to use, in determining the placement of the expression in relation to the matrix action clause, or both. The paper presents the mappings between these features and the choice and placement of appropriate purpose expressions in each language.
Confrontation and support in bonobo-human discourse
Authors: Benson James D. , Fries Peter H. , Greaves William S. , Iwamoto Kazuyoshi , Savage-Rumbaugh E. Sue , Taglialatela Jared
Published: June 2012

As part of a program to explore the communicative abilities of bonobo apes within the human-ape culture at the Language Research Center at Georgia State University, we made two complementary analyses of a conversation between Sue Savage-Rumbaugh and Kanzi. We made both a conversation analysis and a lexico-grammatical analysis of their interaction. The conversation analysis revealed the participants negotiating the interpersonal meanings of confrontation and support, while the lexico-grammatical analysis revealed the ideational domain of the confrontation and support. Although many of the contributions of both participants did not fully express all the relevant meanings, both participants interpreted each others contributions in terms of their relevance to the patterns of interpersonal and ideational meanings being expressed in the conversation. We conclude that Kanzis considerable language abilities have been underestimated. First, Kanzi (despite his limited syntax) and Sue jointly construe a recognizable social world through discourse. Second, in exchanging discourse roles with Sue, Kanzi negotiates the asymmetrical power relation between himself and Sue. Finally, Kanzis accomplishment suggests that discourse semantics is a powerful motivation for the evolution of both interpersonal and ideational grammar.
Rhythmic hierarchy in monologue and dialogue
Authors: Martinec Radan
Published: June 2012

This paper presents a hierarchical model of rhythm and shows its functioning in both monologue and dialogue. Rhythm is seen as articulating speech in both linguistic expression and content, at several levels simultaneously. Each one of the rhythmic levels is formed by rhythmic waves and transitions. Isochrony within waves at one level is formed by periodic occurrences of wave accents from the next-lower level or from a level further below. Since it features both rhythmic regularity and irregularity at various rhythmic levels, the model can account for different degrees of rhythmicality of different types of texts. The hierarchical model of rhythm is placed in the context of other models and the rhythmic patterns of two dialogic passages are compared in detail. Different rhythmic patterns in dialogue are related to different relationships between interactants. The rhythmic analyses are supported by an independent analysis of discourse patterns.
Individual agency in language planning
Authors: Zhao Shouhui , Baldauf Richard B.
Published: June 2012

The literature of language policy and planning (LPP) focuses predominantly on the process of policy formulation and planning programs for implementation, i.e., to use Cooper’s terms, on ‘why’, ‘what’ and ‘how’. The question of the people (‘by whom’ and ‘to whom’) involved in the planning process — i.e. “Who are the actors?” and “What are their roles?” — remains largely unaddressed. Drawing upon experience in the modern history of Chinese script reform in the PRC, this paper extends Harrmann’s notion of the individual’s role in prestige language promotion by categorizing that role into three discrete groups (people with expertise, people with influence, people with power) and then examining their individual agency roles in relation to five stages on the LPP implementation continuum. The authors argue that, to meet the rapidly changing socio-political and technological environment in China today, greater participation of ‘experts’ and ‘influential actors’ — as opposed to those with power — is needed in order to institute effective LPP programs, given the increasing centrality of prestige planning frameworks to LPP implementation as suggested by Haarmann and Ager.
Droits linguistiques et droits de l’homme
Authors: Djité Paulin G.
Published: June 2012

En dépit de la Déclaration des Droits de l’Homme et du Citoyen (1789, article 11), suivie de la Charte des Nations Unies (1945), de la Déclaration universelle des droits de l’homme (1948 : article 2) et de la Convention européenne des droits de l’homme (1950 : articles 4, 6, 10 11, et 14) dont plusieurs articles renvoient à la langue ou présentent une pertinence spécifique à ce propos, de nombreux pays africains, dont la Côte d’Ivoire, ont choisi la langue de l’ancien colonisateur comme langue officielle au moment de leur accès à l’indépendance. Toutes leurs institutions, tous leurs textes juridiques et tous les droits fondamentaux de leurs citoyens sont formulés uniquement et exclusivement dans une langue que la majorité de la population ne parle pas et ne comprend pas. Les droits de l’homme et du citoyen ne trouveraient-ils leur expression que dans la langue de l’ancienne puissance coloniale ? Nous nous proposons ici, après un bref aperçu historique, de répondre à cette question du point de vue de la sociolinguistique du développement : c’est-à-dire, du point de vue de l’impact de la politique des langues, ou de l’absence de celle-ci, sur le quotidien du citoyen, et tout particulièrement dans le cas de la Côte d’Ivoire et terminons cet article avec une réflexion plus générale sur le comportement et les attitudes linguistiques de l’État de Côte d’Ivoire et de ses citoyens.
The Esperanto denaskulo
Authors: Fiedler Sabine
Published: June 2012

Native speakers traditionally occupy a special position in foreign language teaching and learning because their language use is norm-providing. In linguistic studies they are crucial as informants because they decide whether an utterance is correct or incorrect. Although Esperanto as a planned language aims at facilitating international communication by means of a common second language, there are also people who speak this language as a mother tongue, a fact that has recently received growing attention both within and beyond the Esperanto-speaking community. The phenomenon deserves attention because it throws light on the character of the speech community, and especially on questions of language loyalty and speaker identity. In addition, the use of Esperanto as a family language stimulates the development of the language. However, the status of Esperanto native speakers cannot be equated with the status of native speakers of an ethnic language both because of their limited number and also because Esperanto is only one of their mother tongues among several. Above all, native Esperanto speakers do not decide on the standard of the planned language.
Evaluating a Novel Passive Integrated Transponder Tag in Largemouth Bass
Authors: Siepker Michael J. , Knuth David S. , Ball Elizabeth L. , Koppelman Jeffrey B.
Published: June 2012

Passive integrated transponder (PIT) tags are used in fisheries evaluations as a means of marking individual fish because they often have high retention rates, can be passively detected, do not affect fish behavior, and typically do not increase the mortality rates of the study fish. One potential limitation of current PIT tag designs is their glass encapsulation, which could be hazardous to humans if inadvertently consumed. In response to these concerns, plastic infusion process (PIP) PIT tags that are fully encapsulated in food-grade polymers have recently been developed. We tested in experimental ponds the retention rates of two PIT tag types (i.e., glass and PIP) implanted into two anatomical locations (i.e., the intraperitoneal cavity and dorsal musculature) in two groups of largemouth bass Micropterus salmoides. Retention of both tag types was excellent, with only one glass tag being expelled during the study. Survival was higher in control fish than in tagged fish; however, tag type and anatomical tagging location did not influence mortality rates of tagged individuals. The mortality of tagged fish in one trial was related to fish size, the larger individuals surviving better in ponds than their smaller conspecifics. Overall, both tag types performed very well in both anatomical tagging locations. We recommend that fisheries personnel consider the new PIP PIT tags if their work involves tagging fish that could be captured and used for human consumption; however, the size of the study specimens could influence their survival.

Received August 4, 2011; accepted January 25, 2012
Environmental and Population Strain Effects on Survival of Lahontan Cutthroat Trout in Walker Lake, Nevada: A Bayesian Approach
Authors: Sedinger James S. , Blomberg Erik J. , VanDellen Amanda W. , Byers Stephanie
Published: June 2012

Lahontan cutthroat trout Oncorhynchus clarkii henshawi are listed as threatened under the U.S. Endangered Species Act. Populations inhabiting terminal lakes in the Great Basin of Utah and adjacent states face increasing salinity associated with increased anthropogenic use of water and climate change. We used tag recovery models and Markov chain–Monte Carlo methods to assess models of variation in annual survival and tag recovery rates for two genetic strains (Pilot Peak and Pyramid Lake) of Lahontan cutthroat trout stocked into Walker Lake, Nevada, from 1998 to 2008. The best-performing model of annual survival and tag recoveries allowed recovery probability in the first year after release to differ from subsequent recovery rates. The best model contained an interaction between strain and total dissolved solids (TDS) for annual survival. That is, the annual survival of both strains declined as TDS increased, but the Pilot Peak strain was more sensitive to TDS than was the Pyramid Lake strain. The annual survival of fish from the Pilot Peak strain was higher than that of the Pyramid Lake strain at all but the highest TDS levels. Although TDS levels in 2005–2008 were too high to warrant continued stocking of cutthroat trout into Walker Lake, if flows into Walker Lake are increased sufficiently to return TDS levels to those of the late 1990s, the Pilot Peak strain should be stocked.

Received August 24, 2011; accepted February 6, 2012
Tag Retention of T-Bar Anchor Tags and Passive Integrated Transponder Tags in Shovelnose Sturgeon
Authors: Hamel Martin J. , Hammen Jeremy J. , Pegg Mark A.
Published: June 2012

Capture–recapture methods are commonly used to estimate population parameters when the necessary assumptions are met. One of the broadest assumptions of capture–recapture models is that tags are not lost. Therefore, one must understand tag retention to be able to adjust estimates if tag loss occurs. Our objectives were to (1) determine retention rates of T-bar anchor tags and passive integrated transponder (PIT) tags injected into the dorsal musculature of shovelnose sturgeon Scaphirhynchus platorynchus and (2) determine whether using an alternative PIT-tagging location (the operculum) and a new tagging procedure (cyanoacrylate [i.e., superglue] to seal the tag insertion point) provided higher retention. The T-bar tags had a retention rate of 100%; PIT tag retention, however, was more variable. Injection of PIT tags along the dorsal fin resulted in a retention rate of 73%, and tag loss was observed throughout the 98-d experiment. The application of cyanoacrylate did not appear to deter PIT tag loss; retention rates before and after cyanoacrylate was applied were 73% and 77%, respectively. Further, we observed a similar trend of continual PIT tag loss throughout the experiment. The operculum location resulted in a 92% PIT tag retention rate and showed no trend in cumulative loss through time. The high retention rate of PIT tags placed in the operculum suggests that this location is a reliable alternative to inserting PIT tags along the dorsal fin of adult Scaphirhynchus species. In addition, the excellent retention of T-bar tags makes them a viable option for use in Scaphirhynchus studies.

Received October 8, 2011; accepted March 1, 2012
Comparison of Catch Efficiencies between Black and Galvanized Minnow Traps
Authors: Paradis Yves , Dupuch Angélique , Magnan Pierre
Published: June 2012

Minnow traps are widely used in aquatic ecology for the quantitative sampling of small-bodied fish. We used paired sampling stations to compare the catch efficiency of minnow traps constructed of galvanized steel with that of traps constructed of steel mesh covered with a black vinyl coating in field and laboratory conditions. Except for northern redbelly dace Phoxinus eos in field sampling, the catch efficiency of the galvanized minnow traps was higher than that of the black traps. Catches of pumpkinseed Lepomis gibbosus, creek chub Semotilus atromaculatus, and white sucker Catostomus commersonii were up to five times higher in the galvanized minnow traps than in the black ones. For the quantitative estimation of small-bodied fish, we recommend using only galvanized minnow traps to maximize catch efficiency. If data are intended for quantitative analyses, mixing minnow trap models in a field survey could lead to inappropriate catch comparisons.

Received October 31, 2011; accepted January 23, 2012
Correlation of Parasites with Growth of Yellow Perch
Authors: Cloutier Véronique B. , Glémet Hélène , Ferland-Raymond Bastien , Gendron Andrée D. , Marcogliese David J.
Published: June 2012

The possible influence of parasites on the short-term and long-term growth and condition of yellow perch Perca flavescens was examined by investigating correlations between parasite abundance and specific growth variables. The following parasites were enumerated in age-1 yellow perch collected from Lake St. Pierre in June 2008: Apophallus brevis, Diplostomum spp., Ichthyocotylurus spp., Tylodelphys scheuringi, Phyllodistomum superbum, and Raphidascaris acus. Short-term growth was estimated using RNA/DNA ratios and long-term growth via the total length and condition as measured by the Fulton index. No correlation was found between parasite abundance and short-term growth, but a negative influence of combined infections of T. scheuringi and P. superbum on long-term growth was detected. In addition, the abundance of Ichthyocotylurus spp. was positively correlated with the condition of the yellow perch. Together these results suggest that limited or subtle pathogenic effects in juvenile fish are not discernable in recent growth but only in long-term growth indices. Furthermore, in future studies examination of parasite effects on fish growth should account for multiple infections.

Received September 29, 2011; accepted January 20, 2012
Conservation Aquaculture of Northern Leatherside Chub and Effects of Temperature on Egg Survival
Authors: Bartley Matthew S , Wagner Eric J , Oplinger Randall W
Published: June 2012

We present 4 years of data that refine aquaculture protocols for the northern leatherside chub Lepidomeda copei, a species of conservation concern in the Intermountain West. Experiments examined life history traits (age at first spawning and thermal limits to egg hatching success) and aquaculture techniques (brood density, spawning substrate type and surface area, and feeding methods for fry). Tests showed that leatherside chub can reproduce as early as age 2. Multiple spawns per female during a year were also documented. Survival of eggs was compared at incubation temperatures of 18.4, 23.0, 24.6, and 26.8°C. Eggs at 18.4°C had the highest survival to hatching (54.0%); eggs at 26.8°C had significantly lower survival (1.5%). Egg survival at 23.0°C and 24.6°C (32–33%) was significantly lower than survival at 18.4°C. Aquaculture experiments showed that the mean total number of eggs produced did not significantly differ between brood densities of 8.4 (1,246 ± 1,236 eggs [mean ± SD]) or 16.8 (2,224 ± 1,600 eggs) fish/m3. Studies showed that leatherside chub preferred spawning over natural cobble substrate to spawning over marble substrate. More eggs were recovered from a three-substrate tray treatment (1,350 cm2) than from a single tray treatment (450 cm2). Fry given brine shrimp Artemia spp. with probiotic bacteria or fed with an automated, more continuous drip feeder did not show any advantages in growth over time. Juveniles at rearing densities of 800, 1,700, and 3,400 fish/m3 did not differ significantly in growth rates, deformities, or mortalities. This research provides general guidelines for rearing northern leatherside chub and some additional information on the species’ life history.
F-actin polymerization and retrograde flow drive sustained PLCγ1 signaling during T cell activation
Authors: Babich Alexander , Li Shuixing , O'Connor Roddy S. , Milone Michael C. , Freedman Bruce D. , Burkhardt Janis K.
Published: June 2012

Activation of T cells by antigen-presenting cells involves assembly of signaling molecules into dynamic microclusters (MCs) within a specialized membrane domain termed the immunological synapse (IS). Actin and myosin IIA localize to the IS, and depletion of F-actin abrogates MC movement and T cell activation. However, the mechanisms that coordinate actomyosin dynamics and T cell receptor signaling are poorly understood. Using pharmacological inhibitors that perturb individual aspects of actomyosin dynamics without disassembling the network, we demonstrate that F-actin polymerization is the primary driver of actin retrograde flow, whereas myosin IIA promotes long-term integrity of the IS. Disruption of F-actin retrograde flow, but not myosin IIA contraction, arrested MC centralization and inhibited sustained Ca2+ signaling at the level of endoplasmic reticulum store release. Furthermore, perturbation of retrograde flow inhibited PLCγ1 phosphorylation within MCs but left Zap70 activity intact. These studies highlight the importance of ongoing actin polymerization as a central driver of actomyosin retrograde flow, MC centralization, and sustained Ca2+ signaling.