2,293,600 research outputs found
Recent Advances in Homogeneous Metal-Catalyzed Aerobic C–H Oxidation of Benzylic Compounds
Csp(3)-H oxidation of benzylic methylene compounds is an established strategy for the synthesis of aromatic ketones, esters, and amides. The need for more sustainable oxidizers has encouraged researchers to explore the use of molecular oxygen. In particular, homogeneous metal-catalyzed aerobic oxidation of benzylic methylenes has attracted much attention. This account summarizes the development of this oxidative strategy in the last two decades, examining key factors such as reaction yields, substrate: catalyst ratio, substrate scope, selectivity over other oxidation byproducts, and reaction conditions including solvents and temperature. Finally, several mechanistic proposals to explain the observed results will be discussed.(IT-774-13 (Basque Government) and CTQ2017-86630-P (Spanish Ministry of Economy and Competitiveness) projects
Crossing the ‘Uncanny Valley’: Adaptation to Cartoon Faces Can Influence Perception of Human Faces
In this study we assessed whether there is a single face space common to both human and cartoon faces by testing whether adaptation to cartoon faces can affect perception of human faces. Participants were shown Japanese animation cartoon videos containing faces with abnormally large eyes. The use of animated videos eliminated the possibility of position-dependent retinotopic adaptation (because the faces appear at many different locations) and more closely simulated naturalistic exposure. Adaptation to cartoon faces with large eyes significantly shifted preferences for human faces toward larger eyes, consistent with a common, non-retinotopic representation for both cartoon and human faces. This supports the possibility that there are representations that are specific to faces yet common to all kinds of faces
Hemi-field memory for attractiveness
In order to determine whether or not facial attractiveness plays a role in hemispheric facial memory, 35 right-handed participants first assigned attractiveness ratings to faces and then performed a recognition test on those faces in the left visual half-field (LVF) and right visual half-field (RVF). We found significant interactions between the experimental factors and visual half- field. There were significant differences in the extreme ends of the rating scale, that is, the very unattractive versus the
very attractive faces: Female participants remembered very attractive faces of both women and men, with memory being superior in the RVF than in the LVF. In contrast,
the male participants remembered very unattractive faces of both women and men; RVF memory was better than the LVF for women faces while for men faces memory was superior in the LVF. The interactions with visual half-field suggest that hemispheric biases in remembering faces are influenced by degree of attractiveness
Faces of Birkhoff Polytopes
The Birkhoff polytope B(n) is the convex hull of all (n x n) permutation
matrices, i.e., matrices where precisely one entry in each row and column is
one, and zeros at all other places. This is a widely studied polytope with
various applications throughout mathematics.
In this paper we study combinatorial types L of faces of a Birkhoff polytope.
The Birkhoff dimension bd(L) of L is the smallest n such that B(n) has a face
with combinatorial type L.
By a result of Billera and Sarangarajan, a combinatorial type L of a
d-dimensional face appears in some B(k) for k less or equal to 2d, so bd(L) is
at most d. We will characterize those types whose Birkhoff dimension is at
least 2d-3, and we prove that any type whose Birkhoff dimension is at least d
is either a product or a wedge over some lower dimensional face. Further, we
computationally classify all d-dimensional combinatorial types for d between 2
and 8.Comment: 29 page
Using recognition-induced forgetting to assess forgetting of racial minority faces
Recognition-induced forgetting is a forgetting effect whereby items held in visual long-term memory are forgotten as a consequence of recognizing other items of the same category. Previous research has demonstrated that recognition-induced forgetting occurs for White faces but not Black faces. Specifically, while recognizing one White face leads to the forgetting of another, memory for Black faces is undisturbed in the same situation. In the real world, the immunity of Black faces to recognition-induced forgetting could cause disproportionately more positive eyewitness identifications of Black suspects than White suspects. Are racial minority faces immune to recognition-induced forgetting? Here we tested recognition-induced forgetting of Asian faces. Despite replicating the immunity of Black faces to recognition-induced forgetting, Asian faces were susceptible to recognition-induced forgetting. These findings suggest that racial minority status of the face does not create immunity to recognition-induced forgetting.No embargoAcademic Major: Psycholog
Facial aesthetics: babies prefer attractiveness to symmetry
The visual preferences of human infants for faces that varied in their attractiveness and in their symmetry about the midline were explored. The aim was to establish whether infants' visual preference for attractive faces may be mediated by the vertical symmetry of the face. Chimeric faces, made from photographs of attractive and unattractive female faces, were produced by computer graphics. Babies looked longer at normal and at chimeric attractive faces than at normal and at chimeric unattractive faces. There were no developmental differences between the younger and older infants: all preferred to look at the attractive faces. Infants as young as 4 months showed similarity with adults in the 'aesthetic perception' of attractiveness and this preference was not based on the vertical symmetry of the face
Betty Faces a Poser
Short promotional pamphlet designed to attract career-minded female students to Bryant College. Contains a short story about Betty, a hypothetical student, telling a friend the advantages of studying business at Bryant, as well as some factual information about the school and photos of the Providence campus
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