5,047 research outputs found

    The acquisition of English L2 prosody by Italian native speakers: experimental data and pedagogical implications

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    This paper investigates Yes-No question intonation patterns in English L2, Italian L1, and English L1. The aim is to test the hypothesis that L2 learners may show different acquisition strategies for different dimensions of intonation, and particularly the phonological and phonetic components. The study analyses the nuclear intonation contours of 4 target English words and 4 comparable Italian words consisting of sonorant segments, stressed on the semi-final or final syllable, and occurring in Yes-No questions in sentence-final position (e.g., Will you attend the memorial?, Hai sentito la Melania?). The words were contained in mini-dialogues of question-answer pairs, and read 5 times by 4 Italian speakers (Padova area, North-East Italy) and 3 English female speakers (London area, UK). The results show that: 1) different intonation patterns may be used to realize the same grammatical function; 2) different developmental processes are at work, including transfer of L1 categories and the acquisition of L2 phonological categories. These results suggest that the phonetic dimension of L2 intonation may be more difficult to learn than the phonological one

    CT-based tumour response criteria compared after combined treatment for liver metastases of colorectal cancer

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    open6noPurpose: The aim of this analysis is to compare different tumour response criteria (TRC) after chemotherapy combined with bevacizumab in liver metastases from colorectal cancer (mCRC) to ascertain the best early prognostic indicator of response. Methods and Materials: 103 target liver metastases from 65 mCRC patients treated with chemoterapy plus bevacizumab were examined at the Istituto Oncologico Veneto IOV-IRCSS (March 2008-January 2013). All patients had baseline CT and at least one follow-up scan. Tumour response was retrospectively analyzed by two radiologists using RECIST1.1, modified Choi, and Chun morphologic criteria. Tumour response, classified as good (complete or partial response) or poor (stable or progressive disease), was compared with progression-free survival (PFS) at first follow-up (t1) and time of best response. Interobserver agreement and concordance between TRC were measured. Results: At t1, 32.31% showed a good response according to RECIST1.1 (median PFS 11.1), 84.62% according to Choi (median PFS 10.8). These percentages rose to 49.23% (median PFS 12.1) and 87.69% (median PFS 10.8), respectively, at the time of best response. According to Chun, 67.69% showed a good response at the time of best response (median PFS 10.8). The Choi criteria detected a higher proportion of good responders at t1, showing a better correlation with PFS; all methods correlated with PFS at the time of best response. Conclusion: The Choi criteria proved more consistent in the early detection of response in mCRC treated with chemotherapy plus bevacizumab, underscoring the importance of using these criteria in the early assessment of response to combined treatment.openopenVarotto, A.; Di Grazia, L.; Aliberti, C.; Bergamo, F.; Nardin, M.; Pomerri, F.Varotto, A.; Di Grazia, L.; Aliberti, C.; Bergamo, F.; Nardin, M.; Pomerri, Fabi

    The Vehicle Routing Problem with Divisible Deliveries and Pickups

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    The vehicle routing problem with divisible deliveries and pickups is a new and interesting model within reverse logistics. Each customer may have a pickup and delivery demand that have to be served with capacitated vehicles. The pickup and the delivery quantities may be served, if beneficial, in two separate visits. The model is placed in the context of other delivery and pickup problems and formulated as a mixed-integer linear programming problem. In this paper, we study the savings that can be achieved by allowing the pickup and delivery quantities to be served separately with respect to the case where the quantities have to be served simultaneously. Both exact and heuristic results are analysed in depth for a better understanding of the problem structure and an average estimation of the savings due to the possibility of serving pickup and delivery quantities separately

    Structure and electronic properties of the quasi-one-dimensional Ba₂Co₁₋ₓZnₓS₃ series

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    This work focuses on the structure and physical properties of the solid solution Ba₂Co₁₋ₓZnₓS₃ (0 ≀ x ≀ 1), a family of quasi-one-dimensional sulfides with end members Ba₂CoS₃ and Ba₂ZnS₃. The structure of selected compounds with increasing ZnÂČâș content has been analysed using, neutron diffraction, TEM and EXAFS and the physical properties via magnetic susceptibility and resistivity measurements. The progressive substitution of the non-magnetic ZnÂČâș cation for CoÂČâș rapidly destroys the antiferromagnetic transition present at 46 K in the quasi one-dimensional Ba₂CoS₃, leading to paramagnetic behaviour down to the lowest investigated temperature (5K) for compounds with x > 0.25. For compounds with x ≄ 0.4, a pure CW regime is recovered around 300 K, yielding effective moments consistent with the g factor of the tetrahedrally coordinated CoÂČâș previously determined for Ba₂CoS₃. The ZnÂČâș/CoÂČâș substitution also removes the metallic-like behaviour of Ba₂CoS₃ causing an increase in the value of the resistivity with all the Ba₂Co₁₋ₓZnₓS₃ compounds showing semiconducting behaviour. The negative magnetoresistance of Ba₂CoS₃ is improved by the ZnÂČâș/CoÂČâș substitution, with values of – 6% for Ba₂Co₀.₇₅Zn₀.₂₅S₃, – 9% for Ba₂Co₀.₅Zn₀.₅S₃ and – 8% for Ba₂Co₀.₂₅Zn₀.₇₅S₃. However, there does not seem to be a correlation between the values of the resistivity and the magnetoresistance and the content of ZnÂČâș, leading to the hypothesis that transport properties may be linked more closely to extrinsic properties

    Altruism and Gender in the Trust Game

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    2This paper analyses gender differences in the trust game. Our experiment implements the triadic design proposed by Cox (2004) to discriminate between transfers resulting from trust or trustworthiness and transfers resulting from altruistic preferences. We observe that women exhibit a higher degree of altruism than men for both trust and trustworthiness but relatively more for trustworthiness. This result provides an explanation to the experimental finding that women reciprocate more than men.reservedmixedA. INNOCENTI; MARIA GRAZIA PAZIENZAInnocenti, Alessandro; MARIA GRAZIA, Pazienz

    Introduction to true bugs (Heteroptera) of the neotropics.

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    Improving biological production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) co-polymer: a critical review

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    AbstractAlthough poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is the most promising biopolymer for petroleum-based plastics replacement, the low processes productivity as well as the high sale price represent a major barrier for its widespread usage. The present work examines comparatively the existing methods to enhance the yield of the PHBV co-polymer biologically produced and/or reduce their costs. The study is addressed to researchers working on the development of new biological production methods and/or the improvement of those currently used. At this aim, the authors have considered the analysis of some crucial aspects related to substrates and microorganism's choice. The production strategies have been individuated, presented and discussed, either based on a single aspect (type of substrate or microorganism) or based on combined aspects (type of substrate and microorganism). Process operating conditions have been discussed as well. The analysis indicates that the addition of 3HV precursors is capable to dramatically enhance the hydroxyvalerate fraction in the produced biopolymers. On the other hand, due to the high costs of the 3HV precursors, the utilization of wild bacterial species capable to produce the hydroxyvalerate fraction from unrelated carbon sources (i.e. no 3HV precursors) also can be considered a valuable strategy for costs reduction. Moreover, metabolic engineering techniques can be successfully used to promote 3HV precursors-independent biosynthesis pathways and enhance the process productivity. The use of mixed cultures or extremophile bacteria avoids the need of sterile working conditions, and therefore favours the process scale-up. The utilization of the organic waste as substrate plays a key role for a sharp reduction of production costs. Finally, the selection of the most suitable substrate-microorganism combination cannot be separated by the adoption of an appropriate choice of reactor configuration and abiotic factors. Graphic abstrac
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