The development of spontaneous facial responses to others’ emotions in infancy. An EMG study

Viewing facial expressions often evokes facial responses in the observer. These spontaneous facial reactions (SFRs) are believed to play an important role for social interactions. However, their developmental trajectory and the underlying neurocognitive mechanisms are still little understood. In the current study, 4- and 7-month old infants were presented with facial expressions of happiness, anger, and fear. Electromyography (EMG) was used to measure activation in muscles relevant for forming these expressions: zygomaticus major (smiling), corrugator supercilii (frowning), and frontalis (forehead raising). The results indicated no selective activation of the facial muscles for the expressions in 4-month-old infants. For 7-month-old infants, evidence for selective facial reactions was found especially for happy faces (leading to increased zygomaticus major activation) and fearful faces (leading to increased frontalis activation), while angry faces did not show a clear differential response. This suggests that emotional SFRs may be the result of complex neurocognitive mechanisms which lead to partial mimicry but are also likely to be influenced by evaluative processes. Such mechanisms seem to undergo important developments at least until the second half of the first year of life

Dynamic Covalent Macrocyclic Poly(phthalaldehyde)s: Scrambling Cyclic Homopolymer Mixtures Produces Multi-Block and Random Cyclic Copolymers

We recently reported the cationic polymerization of <i>o</i>-phthalaldehyde to macrocyclic poly­(phthalaldehyde) polymers. Resubjecting the cyclic polymers to the polymerization conditions led to a redistribution of the polymer to a new cyclic structure consistent with thermodynamic equilibrium. We now report the synthesis of cyclic poly­(phthalaldehyde) derivatives and demonstrate the scrambling of distinct homopolymer mixtures to copolymers under the cationic polymerization conditions. Homopolymer mixtures are found to rapidly redistribute, first to multiblock cyclic copolymers. With extended reaction time, random macrocyclic copolymers are obtained. Evolution of the microstructure was monitored by NMR spectroscopy, MALDI–TOF mass spectrometry, and gel permeation chromatography (GPC). The reported scrambling method leads to the rapid preparation of macrocyclic copolymers of high molecular weight with variable microstructure depending on reaction times and catalyst loadings

End Group Characterization of Poly(phthalaldehyde): Surprising Discovery of a Reversible, Cationic Macrocyclization Mechanism

End-capped poly­(phthalaldehyde) (PPA) synthesized by anionic polymerization has garnered significant interest due to its ease of synthesis and rapid depolymerization. However, alternative ionic polymerizations to produce PPA have been largely unexplored. In this report, we demonstrate that a cationic polymerization of <i>o</i>-phthalaldehyde initiated by boron trifluoride results in cyclic PPA in high yield, with high molecular weight, and with extremely high cyclic purity. The cyclic structure is confirmed by NMR spectroscopy, MALDI-TOF mass spectrometry, and triple-detection GPC. The cyclic polymers are reversibly opened and closed under the polymerization conditions. Owing to PPA’s low ceiling temperature, cyclic PPA is capable of chain extension to larger molecular weights, controlled depolymerization to smaller molecular weights, or dynamic intermixing with other polymer chains, both cyclics and end-capped linears. These unusual properties endow the system with great flexibility in the synthesis and isolation of pure cyclic polymers of high molecular weight. Further, we speculate that the absence of end groups enhances the stability of cyclic PPA and makes it an attractive candidate for lithographic applications

En riktig pärla – framförställda adjektivattribut i resekataloger

Avhandlingen behandlar framförställda adjektivattribut i resekataloger. Ett adjektivattribut är en adjektivfras som fungerar som bestämning på satsens huvudord. Materialet är tre resekataloger publicerade av den svenska resebyrån BIG Travel: Australienkatalogen, Europakatalogen och Golfkatalogen. Totalt omfattar materialet 60 sidor. Avhandlingen betonar annonsering och marknadsföringskommunikation – syftet var att ta reda på hur och i vilken utsträckning man använder adjektivattribut i resespråket. Jag ville också utreda hur adjektivattribut fördelar sig statistiskt, hur man använder adjektivets böjningsformer (positiv, komparativ, superlativ) samt hurdana skillnader det finns mellan de tre katalogerna i bruket av adjektivattribut. Mina forskningsmetoder var kvalitativa och kvantitativa. Varje katalog är representerad med 20 sidor. Jag excerperade alla framförställda adjektivattribut och gjorde en lista för varje katalog. I slutet av listan angav jag antalet positiv-, komparativ- och superlativformer samt vilka som är de frekventaste attributen. I resespråket är det positivformen som är oftast i bruk: det beror troligen på att man vill hålla stilen neutral och inte skapa motsättning. Det finns en betydelsefull skillnad i attributantal mellan Australienkatalogen och Europakatalogen: resmål i Europa beskrivs med tydligt fler attribut jämfört med Australien. Det totala antalet adjektivattribut ligger på 1608 (Australienkatalogen 436, Golfkatalogen 561, Europakatalogen 610). Det finns alltså en enorm variation och bland denna variation är det få attribut som upprepas ofta. Den här trenden syns i alla kataloger. Slutsatsen är att reseskribenter försöker att uttrycka saker på nya, varierande sätt, vilket kan göras med olika adjektiv. På vissa adjektivattribut litar man mer än på andra och därför används dessa attribut oftare.Siirretty Doriast

Depolymerizable, adaptive supramolecular polymer nanoparticles and networks

Incorporation of supramolecular cross-linking motifs into low-ceiling temperature (Tc) polymers allows for the possibility of remendable polymeric networks and nanoparticles whose structure and chemical backbones can be dynamically modified or depolymerized as desired. Herein, we demonstrate the synthesis of phthalaldehyde-benzaldehyde copolymers bearing a pendant dimerizing 2-ureido-pyrimidinone (UPy) motif. The UPy moiety promotes single-chain polymeric nanoparticle formation through non-covalent cross-linking at intermediate concentrations and results in reversible polymer network formation at high concentrations. Furthermore, due to the low Tc polymer backbone within such macromolecules, the materials depolymerize to monomer under appropriate conditions. We envision that the synthesis of such depolymerizable, adaptive supramolecular polymeric materials may find use in materials capable of self-healing and remodeling as well as in triggered release applications or the development of nanoporous structures