Influence of Ag Electrodes Asymmetry Arrangement on Their Erosion Wear and Nanoparticle Synthesis in Spark Discharge

For nanoparticle synthesis in a spark discharge, the influence of the degree of electrode asymmetry in the rod-to-rod configuration, using the example of silver electrodes, on the energy efficiency and nanoparticle composition is studied. The asymmetry degree was determined by the angle between electrodes’ end faces. Two types of discharge current pulses were used: oscillation-damped and unipolar, in which electrodes changed their polarities and had a constant polarity during a single discharge, respectively. A significant influence of the asymmetry degree of the electrode arrangement on the synthesized nanoparticle size, agglomeration and concentration, and on the synthesis energy efficiency, has been established. An increase in the degree of the electrode asymmetry with the oscillation-damped discharge current pulse led to an increased mass production rate and energy efficiency of nanoparticle synthesis, a significant fraction of which had large dimensions of more than 40 nm. The effect of the transfer of synthesized nanoparticles to the opposite electrode at the unipolar discharge current pulse led to the appearance of electroerosive instability, manifested in the formation of a protrusion on the anode surface, around which spark discharges, leading to its further growth and electrode gap closure.

Question tags in Cameroon English

Although English is one of the two official languages in Cameroon, it is seldom used out of official circles where indigenous languages, French, and Pidgin English reign supreme (Jikong & Koenig, 1983). This has made the language a matter of concern for teachers, learners, and researchers. An aspect of the language which has so far been little investigated, but which is significant to English proficiency, is question tags. In fact, question tags contribute tremendously to the flow of language. They are ‘a very conspicuous phenomenon of spoken language’ (Tottie & Hoffman, 2006: 284). These short questions (tags), tagged onto a main statement (the anchor) play an important role in spoken English. While the question tag is taught from Sixième to Terminale (Grade 8 to Grade 13, i.e. the first to last years of secondary education in the Francophone subsystem of education), and from primary to secondary school in the Anglophone subsystem of education in Cameroon, researchers are still to question its teaching against the backdrop of its actual use in a country where the nativisation process of English is generally agreed upon (Schneider, 2009). Also, given that the canonical ‘type of tag question with reversed or constant polarity, (. . .) is typical of English’ (Tottie & Hoffman, 2006: 283), its teaching (textbooks focus solely on question tags with reversed or constant polarity) in a non-native setting like Cameroon is likely to foretell a conscious or unconscious desire to keep a certain standard of English. If one concurs with Schneider (2009) that Cameroon is on Phase Three of the Dynamic model (at least in the Anglophone part of the country) – that is, Nativisation where ‘structural nativization has made substantial progress’ (p. 298) – then keeping a native-like standard on school programmes (Ministry of Secondary Education, 2014), textbooks (see for illustration the English textbook Forbin et al., 2019), and official examinations would be likely to indicate some contradictions as per the apparent desire to cut the umbilical cord with the former colonial power.

The prosody of question tags in English

The prosodic realization of English question tags (QTs) has received some interest in the literature; yet corpus studies on the factors affecting their phrasing and intonational realization are very rare or limited to a certain aspect. This article presents a quantitative corpus study of 370 QTs from theInternational Corpus of Englishthat were annotated for prosodic phrasing and intonational realization of the QT and the host. Factors tested were polarity, position in the sentence and the turn as well as verb type. Generally, prosodic phrasing and intonational realization were highly correlated: separate QTs were mostly realized with a falling contour, while integrated QTs were mostly rising. Results from regression models showed a strong effect of polarity: QTs with an opposite polarity were more often phrased separately compared to QTs with constant polarity, but the phrasing of opposite polarity QTs was further dependent on whether the QT was negative or positive (more separate phrasing in negative QTs). Furthermore, prosodic separation was more frequent at the end of syntactic phrases and clauses compared to phrase-medial QTs. At the end of a turn, speakers realized more rising contours compared to QTs within a speaker's turn. Verb type also had an effect on the phrasing of the tag. Taken together, our results confirm some of the claims previously held for QTs, while others are modified and new findings are added.

A cross-linguistic study of grammatically-dependent question tags

This article proposes a new categorization of confirmation-seeking question tags, based on how the use of such tags is restricted in relation to the preceding clause, the anchor. The focus is on a category labelled grammatically-dependent question tags (GDQTs). Earlier research has claimed that almost only English has such question tags, but this article presents and compares data on GDQTs from more than ten languages, and suggests a hierarchy for features of grammatical dependence in question tags: polarity < tense < number/person < (semantic) gender (possibly also < verb substitution). The GDQT structures vary in different ways: all GDQT languages have negative GDQTs, but not all have positive GDQTs; verb substitution is not always applied and constant polarity instead of reversed polarity is also found.

Tag questions in Welsh

Modern Colloquial Welsh (MCW) displays a considerable variety of tag question patterns. In this paper we offer a unified account for the divergent developments in modern Welsh dialects, focusing on tags attached to “normal” or VSO clauses. We propose a scenario of how the MCW system of tags is descended from the pre-modern system by processes of reanalysis and grammaticalization. We show that South Walian dialects have elaborated a system of tag questions in which the tag reverses the polarity of the anchor to which it is attached, while North Walian dialects have followed a principle of constant polarity in which tags anticipate the polarity of the expected response.

Abstracts: Pragmatics

07–645Félix-Brasdefer, J. César (Indiana U, Bloomington, USA; [email protected]), Linguistic politeness in Mexico: Refusal strategies among male speakers of Mexican Spanish. Journal of Pragmatics (Elsevier) 38.12 (2006), 2158–2187.07–646Fukushima, Kazuhiko (Kansai Gaidai U, Osaka, Japan; [email protected]), Conspiracy of form and context for proper semantic interpretation: The implications of lonesome numeral classifiers in Japanese. Journal of Pragmatics (Elsevier) 39.5 (2007), 960–989.07–647Graham, Sage Lambert (U Memphis, USA; [email protected]), Disagreeing to agree: Conflict, (im)politeness and identity in a computer-mediated community. Journal of Pragmatics (Elsevier) 39.4 (2007), 742–759.07–648Hatipoğlu, Çiler (Middle East Technical U, Ankara, Turkey; [email protected]), (Im)politeness, national and professional identities and context: Some evidence from e-mailed ‘Call for Papers’. Journal of Pragmatics (Elsevier) 39.4 (2007), 760–773.07–649Haugh, Michael (Griffith U, Nathan, Queensland, Australia; [email protected]), The co-constitution of politeness implicature in conversation. Journal of Pragmatics (Elsevier) 39.1 (2007), 84–110.07–650Haugh, Michael (Griffith U, Nathan, Queensland, Australia; [email protected]), Emic conceptualisations of (im)politeness and face in Japanese: Implications for the discursive negotiation of second language learner identities. Journal of Pragmatics (Elsevier) 39.4 (2007), 657–680.07–651Hsieh, Shelley Ching-yu (National Cheng Kung U, Taiwan; [email protected]), A corpus-based study on animal expressions in Mandarin Chinese and German. Journal of Pragmatics (Elsevier) 38.12 (2006), 2206–2222.07–652Huth, Thorsten (Utah State U, Logan, USA; [email protected]), Negotiating structure and culture: L2 learners' realization of L2 compliment-response sequences in talk-in-interaction. Journal of Pragmatics (Elsevier) 38.12 (2006), 2025–2050.07–653Ji, Shaojun (Chinese Culture U, Taipei, Taiwan; [email protected]), A textual perspective on Givón's quantity principle. Journal of Pragmatics (Elsevier) 39.2 (2007), 292–304.07–654Kimps, Ditte (U Leuven, Belgium; [email protected]), Declarative constant polarity tag questions: A data-driven analysis of their form, meaning and attitudinal uses. Journal of Pragmatics (Elsevier) 39.2 (2007), 270–291.07–655Lee, Duck-Young (The Australian National U, Canberra, Australia; [email protected]), Involvement and the Japanese interactive particlesneandyo. Journal of Pragmatics (Elsevier) 39.2 (2007), 363–388.07–656Loock, Rudy (Université de Lille III, Villeneuve d'Ascq, France; [email protected]), Appositive relative clauses and their functions in discourse. Journal of Pragmatics (Elsevier) 39.2 (2007), 336–362.07–657Manetta, Emily (U Vermont, Burlington, USA; [email protected]), Unexpected left dislocation: An English corpus study. Journal of Pragmatics (Elsevier) 39.5 (2007), 1029–1035.07–658Mzushima, Lisa & Paul Stapleton (Hokkaido U, Sapporo, Japan; [email protected]), Analyzing the function of meta-oriented critical comments in Japanese comic conversations. Journal of Pragmatics (Elsevier) 38.12 (2006), 2105–2123.07–659Netz, Hadar & Ron Kuzar (U Haifa, Israel; [email protected]), Three marked theme constructions in spoken English. Journal of Pragmatics (Elsevier) 39.2 (2007), 305–335.07–660Rogerson-Revell, Pamela (U Leicester, UK; [email protected]), Humour in business: A double-edged sword. A study of humour and style shifting in intercultural business meetings. Journal of Pragmatics (Elsevier) 39.1 (2007), 4–28.07–661Ruhi, Şükriye (Middle East Technical U, Ankara, Turkey; [email protected]) & Hale Işık-Güler, Conceptualizing face and relational work in (im)politeness: Revelations from politeness lexemes and idioms in Turkish. Journal of Pragmatics (Elsevier) 39.4 (2007), 681–711.07–662Selting, Margret (Universität Potsdam, Germany; [email protected]), Lists as embedded structures and the prosody of list construction as an interactional ressource. Journal of Pragmatics (Elsevier) 39.3 (2007), 483–526.07–663Soares da Silva, Augusto (Universidade Católica Portuguesa, Braga, Portugal; [email protected]), The polysemy of discourse markers: The case ofprontoin Portuguese. Journal of Pragmatics (Elsevier) 38.12 (2006), 2188–2205.07–664Takimoto, Masahiro (Tezukayama U, Japan; [email protected]), The effects of explicit feedback and form–meaning processing on the development of pragmatic proficiency in consciousness-raising tasks. System (Elsevier) 34.4 (2006), 601–614.

Effect of specific proteolytic cleavages on tubulin polymer formation

The capacity for self-polymerization and shape of the tubulin polymers assembled after digestion with trypsin, Pronase, chymotrypsin, subtilisin, Staphylococcus aureus proteinase V8 and proteinase K were investigated. Digestion with trypsin, Pronase or chymotrypsin resulted in a decrease in the ability of tubulin for self-assembly, whereas limited proteolysis with subtilisin, S. aureus proteinase V8 or proteinase K resulted in an increase in such ability. The shape of the assembled polymers varied from typical microtubules (after the treatment with trypsin or Pronase) to sheets (after the treatment with chymotrypsin) and from hooked microtubules with a constant polarity (after the treatment with subtilisin) to the disappearance of a defined polarity of such polymers (after the treatment with S. aureus V8 proteinase or proteinase K). These results indicate that the tubulin C-terminal regions are involved in the regulation of microtubule polymerization, shape, directional growth and lateral interactions between tubulin protofilaments.