502 research outputs found
Observing the Location and Orientation of Nematocysts Through Aeolidiella Stephaniae
The anemone species Aiptasia is a nuisance pest that can quickly out-compete many species in a coral reef aquarium. The aeolid nudibranch Berghia verrucicornis, now officially known as Aeolidiella stephanieae, consumes only anemones of the Aiptasia species, a feature that has increased its popularity among aquarium overseers everywhere. Not much information exists on the digestive process of these aeolids, but what exists notes that A. stephaniae seem to house parts of the anemone it consumes in the cerata on its back, a practice commonly seen in other aeolids that feed on cnidarian species. By observing the location of nematocysts in A. stephaniae at different intervals, we may be able to determine the path that nematocysts take on their route to the cerata. To observe this trend, we tested three different live stains to determine its potential as a viable stain. The anemones were bathed in the selected stain and fed to the nudibranchs. We found that using a 6.8x10-5 M solution of Aniline Blue was the best for viewing. The A. stephaniae were collected at different times after feeding and fixed so that they might be viewed by light microscopy. Data based on the orientation and location of nematocysts was collected and analyzed
The Error in Trial and Error: Exercises on Phrasal Verbs
An analysis of 44 commercially available EFL textbooks found that it is common for textbooks to present learners with exercises on phrasal verbs without first providing relevant input to help them. In these cases, the learners are likely to resort to trial-and-error and are then expected to learn from feedback. We report an experiment conducted with Japanese EFL students (N=140) in which we compare the effectiveness of such a trial-and-error method with a retrieval procedure in which students first study a set of phrasal verbs and then complete an exercise. Scores on both an immediate and a one-week delayed post-test suggest superiority of retrieval over the trial-and-error procedure, where, despite the provision of feedback, 25% of the wrong exercise responses were reproduced in the delayed post-test
Contrastive focus and emphasis
The paper puts forward a discourse-semantic account of the notoriously evasive phenomena of contrastivity and emphasis. Based on new evidence from Chadic, it is argued that occurrences of focus that are treated in terms of âcontrastive focusâ, âkontrastâ (VallduvĂ-Vilkuna 1998) or âidentificational focusâ (Ă. Kiss 1998) in the literature should not be analyzed in familiar semantic terms as involving the introduction and subsequent exclusion of alternatives. Rather, an adequate analysis must take into account discourse-semantic notions like âhearer expectationâ or âdiscourse expectabilityâ of the focused content in a given discourse situation. The less expected the focus content is judged to be for the hearer, relative to the Common Ground, the more likely a speaker is to mark the focus constituent by means of special grammatical devices, thus giving rise to emphasis
Do online resources give satisfactory answers to questions about meaning and phraseology?
In this paper we explore some aspects of the differences between printed paper dictionaries and online dictionaries in the ways in which they explain meaning and phraseology. After noting the importance of the lexicon as an inventory of linguistic items and the neglect in both linguistics and lexicography of phraseological aspects of that inventory, we investigate the treatment in online resources of phraseology â in particular, the phrasal verbs wipe out and put down â and we go on to investigate a word, dope, that has undergone some dramatic meaning changes during the 20th century. In the course of discussion, we mention the new availability of corpus evidence and the technique of Corpus Pattern Analysis, which is important for linking phraseology and meaning and distinguishing normal phraseology from rare and unusual phraseology. The online resources that we discuss include Google, the Urban Dictionary (UD), and Wiktionary
Untersuchungen zur Reaktivität von Cyclopentadienylchromsulfiden gegenßber Luftsauerstoff und Elektrophilen und RÜntgenstrukturanalyse von Cp*2Cr2(Ο,Ρ2-S2)(Ο-S2) (Cp* = Ρ5-C5Me5)
RNA helicase A interacts with divergent lymphotropic retroviruses and promotes translation of human T-cell leukemia virus type 1
The 5Ⲡuntranslated region (UTR) of retroviruses contain structured replication motifs that impose barriers to efficient ribosome scanning. Two RNA structural motifs that facilitate efficient translation initiation despite a complex 5ⲠUTR are internal ribosome entry site (IRES) and 5Ⲡproximal post-transcriptional control element (PCE). Here, stringent RNA and protein analyses determined the 5ⲠUTR of spleen necrosis virus (SNV), reticuloendotheliosis virus A (REV-A) and human T-cell leukemia virus type 1 (HTLV-1) exhibit PCE activity, but not IRES activity. Assessment of SNV translation initiation in the natural context of the provirus determined that SNV is reliant on a cap-dependent initiation mechanism. Experiments with siRNAs identified that REV-A and HTLV-1 PCE modulate post-transcriptional gene expression through interaction with host RNA helicase A (RHA). Analysis of hybrid SNV/HTLV-1 proviruses determined SNV PCE facilitates Rex/Rex responsive element-independent Gag production and interaction with RHA is necessary. Ribosomal profile analyses determined that RHA is necessary for polysome association of HTLV-1 gag and provide direct evidence that RHA is necessary for efficient HTLV-1 replication. We conclude that PCE/RHA is an important translation regulatory axis of multiple lymphotropic retroviruses. We speculate divergent retroviruses have evolved a convergent RNAâprotein interaction to modulate translation of their highly structured mRNA
The source ambiguity problem: Distinguishing the effects of grammar and processing on acceptability judgments
Judgments of linguistic unacceptability may theoretically arise from either grammatical deviance or significant processing difficulty. Acceptability data are thus naturally ambiguous in theories that explicitly distinguish formal and functional constraints. Here, we consider this source ambiguity problem in the context of Superiority effects: the dispreference for ordering a wh-phrase in front of a syntactically âsuperiorâ wh-phrase in multiple wh-questions, e.g., What did who buy? More specifically, we consider the acceptability contrast between such examples and so-called D-linked examples, e.g., Which toys did which parents buy? Evidence from acceptability and self-paced reading experiments demonstrates that (i) judgments and processing times for Superiority violations vary in parallel, as determined by the kind of wh-phrases they contain, (ii) judgments increase with exposure, while processing times decrease, (iii) reading times are highly predictive of acceptability judgments for the same items, and (iv) the effects of the complexity of the wh-phrases combine in both acceptability judgments and reading times. This evidence supports the conclusion that D-linking effects are likely reducible to independently motivated cognitive mechanisms whose effects emerge in a wide range of sentence contexts. This in turn suggests that Superiority effects, in general, may owe their character to differential processing difficulty
Lexical deconstructionâreview of Giegerich, H., Lexical structures: Compounding and the modules of grammar, Edinburgh Studies in Theoretical Linguistics, vol. 1
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Doing politics in the recent Arab uprisings: Towards a political discourse analysis of the Arab Spring slogans
The present paper aims to analyse a number of those slogans collected from the sit-in quarters in Egypt,
Libya and Yemen. Using political discourse analysis, it unravels various typical discourse structures and
strategies that are used in slogans in the construction of a sub-genre of political discourse in the Arab world.
Drawing data from several mediums, including banners, wall graffiti, audio-visual instruments, chanting,
speeches and songs, this paper tries to show the extent to which the slogans serve as a medium by which
political complaints and comments are dispensed and consumed. This paper draws on a rhetorical analysis to
find out their persuasive effect on shaping the Arab intellect and on the change of the political atmosphere
in the region. Lastly, this paper attempts to show to what extent the slogans meet the standards of political
discourse and whether they can be considered as a sub-genre of political discourse or not.IS
Time-resolved crystallography using the Hadamard transform
YesWe describe a method for performing time-resolved X-ray crystallographic experiments based on the Hadamard transform, in which time resolution is defined by the underlying periodicity of the probe pulse sequence, and signal/noise is greatly improved over that for the fastest pump-probe experiments depending on a single pulse. This approach should be applicable on standard synchrotron beamlines and will enable high-resolution measurements of protein and small-molecule structural dynamics. It is also applicable to other time-resolved measurements where a probe can be encoded, such as pump-probe spectroscopy.Wellcome Trust 4-year PhD program âThe Molecular Basis of Biological Mechanismsâ 089312/Z/09/Z. This work was also supported by the EPSRC Award âDynamic Structural Science at the Research Complex at Harwellâ EP/I01974X/1 and by BBSRC Award BB/H001905/1
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