1. Categorical Perception of a vowel contrast in native speakers and second language learners.Alessandra Zappoli, 2022, published scientific conference contribution abstract Abstract: The perceptual space of a speaker is shaped in infancy according to the phonological inventory of the L1. Phonological categories correlate with Categorical Perception (CP) and Perceptual Magnet (PM) effects, lowering the discrimination rate between the same category’s sounds and increasing it at the Category Boundaries (Liberman et al., 1967; Kuhl et al., 1992).
Second Language (L2) learning in adulthood requires creating new categories, some overlapping with the existing ones. When L2 and L1 categories overlap, the PM and CP effects might block the creation of the target L2 sounds, linked to Foreign Accented speech.
In this study, I investigate with the CP paradigm, the categorization, and discrimination of two German words: ʃɔːn] (‘already’) vs. [ʃøːn] (‘beautiful’) distinguished by a vowel contrast existing in German but not in Italian. I tested: i) 20 L1 speakers of German (L1); 34 L2 learners of German, L1 speakers of Italian – ii) 14 exposed to native speech (Tandem); iii) 18 not exposed to it; iv) 20 L1 speakers of Italian (Naïve). The oddball discrimination task presented the stimuli in 6 orders: AAB, ABA, ABB, BAA, BAB, BBA. L2 learners performed the LEXTALE in German (Lemhöfer & Broersma, 2012).
Results show that the categorization and discrimination performance linearly increase with language proficiency. Categorization only correlates with LEXTALE. Exposure to native speech is relevant. The presence of CP - as classically reported in the literature - is affected by the order of presentation of the stimuli in the oddball paradigm, emerging with BAB, ABA, BBA orders.
Keywords: vowel categorization, speech categorization, naive listeners, native speakers, L2 learners, categorical perception paradigm, perceptual space
Published in RUNG: 30.08.2022; Views: 1236; Downloads: 0
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2. WEAK CLOSURE OPERATIONS WITH SPECIAL TYPES IN LOWER BCK-SEMILATTICESHashem Bordbar, Young Bae Jun, 2017, original scientific article Abstract: The notions of (strong) quasi prime mapping on the set of all ideals, t- type weak closure operation, and tender (resp., naive, sheer, feeble tender) weak closure operation are introduced, and their relations and properties are investigated. Conditions for a weak closure operation to be of t-type are provided. Given a weak closure operation, conditions for the new weak closure operation to be of t-type and to be a naive (sheer, feeble tender) weak closure operation are considered. We show that the new weak closure operation is the smallest tender weak closure operation containing the given weak closure operation.
Keywords: (strong) quasi prime mapping, t-type weak closure operation, naive (sheer, tender, feeble tender) weak closure operation.
Published in RUNG: 02.12.2019; Views: 2845; Downloads: 0
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3. Tender and naive weak closure operations on lower BCK-semilattices.Hashem Bordbar, 2018, original scientific article Abstract: The notion of tender and naive weak closure operation is introduced, and their relations and properties are investigated. Using a weak closure operation "d" and an ideal A of a lower BCK-semilattice X with the greatest element 1, a new ideal K of X containing the ideal Acl of X is established. Using this ideal K, a new function clt : I(X) → I(X); A → K is given, and related properties are considered. We show that if "cl" is a tender (resp., naive) weak closure operation on I(X), then so are "clt" and clf.
Keywords: zeromeet element, meet ideal, relative annihilator, (finite type, tender, naive) weak closure operation.
Published in RUNG: 02.12.2019; Views: 2742; Downloads: 0
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4. Recombinant nanobodies as cheap and customizable reagents for unicellular algae detectionElisa Mazzega, Ario De Marco, Marina Cabrini, Alfred Beran, published scientific conference contribution abstract Abstract: At the present, the identification of planktonic species in coastal water mainly relies on light microscopy
observations. This kind of analyses is performed by highly trained personnel, requires lab equipment and long
processing time. High-throughput and easy-to-perform methods are instead highly needed for routine costal and
ballast water monitoring.
Immuno-reagents are widely employed in the medical field for routine diagnostics, where they provide the necessary
sensitivity and specificity, as for example for cancer subtype characterization. Reagents of similar grade are so far not
widely available for both diagnostics and basic research of microalgae. We describe the first successful isolation of a
single-domain antibody (nanobody or VHH) from a pre-immune library, its engineering into application-ready
reagents, and its inexpensive production as recombinant fusion protein.
Alexandrium minutum was chosen as a model organism to test the feasibility of the procedure. The procedure foresees
the panning of a pre-immune phage library of VHHs that was used for in vitro selection against directly the target cells.
Monoclonal nanobodies specific for A. minutum cells were identified and optimized for recombinant production as
fusion with fluorescent proteins in bacterial hosts. Such fluorescently-tagged VHHs were validated by
immunofluorescence and cytofluorimetry for their selectivity by testing unicellular algal species that can be found in
the same environment of A. minutum. Two nanobodies were found to be highly specific for the target cells, were able
to bind also cysts of A. minutum and they gave no cross-reaction, even for a not-toxic strain of the closely related A.
tamutum.
Different tags can be then fused to the selected nanobodies and used instead of the fluorescent proteins to obtain a
reagent immediately applicable to further techniques, such as cell Enzyme Linked Immuno Sorbent Assay (ELISA) or
biosensor surface functionalization. The newly produced reagents can be applied for direct whole-cell detection in
seawater, bypassing the need of cell processing required for DNA or RNA diagnostics, and can be used for both alive
and fixed cells, guaranteeing the possibility to check old samples and to perform confirmatory morphological studies.
Keywords: Nanobodies, toxic algae, detection, recombinant reagent, naive library, phage display
Published in RUNG: 21.12.2018; Views: 3592; Downloads: 0
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