Control and prediction of degradation of biopolymer based hydrogels with poly(ɛ-caprolactone) subunits.

Complex hydrogels consisting of natural and synthetic polymers, stabilized by combining different physical and chemical cross-linking methods, were assessed by in vitro degradation tests performed at 37°C in phosphate buffer solution. Four biopolymer-based hydrogel series were comparatively evaluated as sponge or dense films as regards mass loss, morphology changes and thermal behavior over the fixed incubation period, considering as main factors of influence the composition, the adopted stabilization mode and the microstructure of the 3D construct. To facilitate the selection of the appropriate material for envisaged applications, matching the specific needs, the obtained data were used to generate an artificial neural network (ANN) model, able to establish correlations of the examined formulations and preparation parameters with mass loss. The comparison of experimental and calculated data showed that the developed ANN shows reasonable predictive performance (rtraining/validation(2)=0.99).

The pronoun attraction effect for d(iscourse)-linked phrases: evidence from speakers of a null subject language.

Frazier and Clifton (2002) argue that a d(iscourse)-linked wh-phrase such as which boy attracts the reference of a pronoun in a subordinate clause. We translated Frazier and Clifton's materials from English into Romanian. Romanian is a pro-drop language in which null subjects are licensed by person and number agreement on the verb. We found that the d-linking attraction effect held for both pro and overt pronouns in Romanian. The fact that the effect is found for pro provides evidence that the attraction effect is not due to gender matching between the pronoun and the head of the d-linked phrase. We also tested native speakers of Romanian learning English as a second language on Frazier and Clifton's English materials Levels of coreference were highly similar to those for English native speakers and intermediate and advanced learners showed the d-linking attraction effect. We discuss the results in the context of Carminati's (2002) Position of Antecedent Hypothesis, arguing that this hypothesis can account for both the fact that higher levels of coreference with a wh-phrase antecedent were found for pro than for an overt pronoun in Romanian and the fact that the coreference levels between an overt pronoun and the wh-phrase antecedent were not elevated for Romanian-speaking second language learners of English.