Preschoolers’ free play - connections with emotional and social functioning

Play has an important role in various aspects of children’s development. However, time for free play has declined substantially over the last decades. To date, few studies have focused on the relationship between opportunities for free play and children’s social functioning. The aims of this study are to examine whether children ́s free play is related to their social functioning and whether this relationship is mediated by children ́s emotional functioning. Seventy-eight children (age, 55- 77 months) were tested on their theory of mind and emotion understanding. Parents reported on their children’s time for free play, empathic abilities, social competence and externalizing behaviors. The main findings showed that free play and children’s theory of mind are negatively related to externalizing behaviors. Empathy was strongly related to children’s social competence, but free play and social competence were not associated. Less time for free play is related to more disruptive behaviors in preschool children, however certain emotional functioning skills influence these behaviors independently of the time children have for free play. These outcomes suggest that free play might help to prevent the development of disruptive behaviors, but future studies should further examine the causality of this relationship.

Quantification of free auxins in semi-hardwood plant cuttings and microshoots by dispersive liquid–liquid microextraction/microwave derivatization and GC/MS analysis

Several studies have suggested that differences in the natural rooting ability of plant cuttings could be attributed to differences in endogenous auxin levels. Hence, during rooting experiments, it is important to be able to routinely monitor the evolution of endogenous levels of plant hormones. This work reports the development of a new method for the quantification of free auxins in auxin-treated Olea europaea (L.) explants, using dispersive liquid–liquid microextraction (DLLME) and microwave assisted derivatization (MAD) followed by gas chromatography/mass spectrometry (GC/MS) analysis. Linear ranges of 0.5–500 ng mL 1 and 1–500 mg mL 1 were used for the quantification of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA), respectively. Determined by serial dilutions, the limits of detection (LOD) and quantification (LOQ) were 0.05 ng mL 1 and 0.25 ng mL 1, respectively for both compounds. When using the calibration curve for determination, the LOQ corresponded to 0.5 ng mL 1 (IAA) and 0.5 mg mL 1 (IBA). The proposed method proved to be substantially faster than other alternatives, and allowed free auxin quantification in real samples of semi-hardwood cuttings and microshoots of two olive cultivars. The concentrations found in the analyzed samples are in the range of 0.131–0.342 mg g 1 (IAA) and 20–264 mg g 1 (IBA).