Alastair Valence Dunlop
Ontology highlight
ABSTRACT:
SUBMITTER:
PROVIDER: S-EPMC1122667 | biostudies-literature | 2002 Mar
REPOSITORIES: biostudies-literature
Similar Datasets
Project description: Not available
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Project description:Valence is a dominant semantic dimension, and it is fundamentally linked to basic approach-avoidance behavior within a broad range of contexts. Previous studies have shown that it is possible to approximate the valence of existing words based on several surface-level and semantic components of the stimuli. Parallelly, recent studies have shown that even completely novel and (apparently) meaningless stimuli, like pseudowords, can be informative of meaning based on the information that they carry at the subword level. Here, we aimed to further extend this evidence by investigating whether humans can reliably assign valence to pseudowords and, additionally, to identify the factors explaining such valence judgments. In Experiment 1, we trained several models to predict valence judgments for existing words from their combined form and meaning information. Then, in Experiment 2 and Experiment 3, we extended the results by predicting participants' valence judgments for pseudowords, using a set of models indexing different (possible) sources of valence and selected the best performing model in a completely data-driven procedure. Results showed that the model including basic surface-level (i.e., letters composing the pseudoword) and orthographic neighbors information performed best, thus tracing back pseudoword valence to these components. These findings support perspectives on the nonarbitrariness of language and provide insights regarding how humans process the valence of novel stimuli.
| S-EPMC11543720 | biostudies-literature
Project description:We performed single-cell RNA-seq (10x Chromium 3' v.3.1) on dissociated single cell suspensions from mouse (C57BL/6) osmosensory brain nuclei - subfornical organ (SFO) to determine transcriptomic cell types and neuronal activation patterns. By performing single cell RNA-seq based stimulus to cell-type mapping, we captured the endogenous immediate early gene expression triggered by distinct physiological state stimuli in SFO cells. We identified a unique excitatory neuron type in SFO that is uniquely tuned to sodium deficiency.
2023-12-22 | GSE244245 | GEO
Project description:The carbide ligand in the iron-molybdenum cofactor (FeMoco) in nitrogenase bridges iron atoms in different oxidation states, yet it is difficult to discern its ability to mediate magnetic exchange interactions due to the structural complexity of the cofactor. Here, we describe two mixed-valent diiron complexes with C-based ketenylidene bridging ligands, and compare the carbon bridges with the more familiar sulfur bridges. The ground state of the [Fe2 (μ-CCO)2 ]+ complex with two carbon bridges (4) is S= 1/2${{ 1/2 }}$ , and it is valence delocalized on the Mössbauer timescale with a small thermal barrier for electron hopping that stems from the low Fe-C force constant. In contrast, one-electron reduction of the [Fe2 (μ-CCO)] complex with one carbon bridge (2) affords a mixed-valence species with a high-spin ground state (S= 7/2${ 7/2 }$ ), and the Fe-Fe distance contracts by 1 Å. Spectroscopic, magnetic, and computational studies of the latter reveal an Fe-Fe bonding interaction that leads to complete valence delocalization. Analysis of near-IR intervalence charge transfer transitions in 5 indicates a very large double exchange constant (B) in the range of 780-965 cm-1 . These results show that carbon bridges are extremely effective at stabilizing valence delocalized ground states in mixed-valent iron dimers.
| S-EPMC10843690 | biostudies-literature
Project description:Non-valence states in neutral molecules (Rydberg states) have well-established roles and importance in photochemistry, however, considerably less is known about the role of non-valence states in photo-induced processes in anions. Here, femtosecond time-resolved photoelectron imaging is used to show that photoexcitation of the S1(ππ*) state of the methyl ester of deprotonated para-coumaric acid - a model chromophore for photoactive yellow protein (PYP) - leads to a bifurcation of the excited state wavepacket. One part remains on the S1(ππ*) state forming a twisted intermediate, whilst a second part leads to the formation of a non-valence (dipole-bound) state. Both populations eventually decay independently by vibrational autodetachment. Valence-to-non-valence internal conversion has hitherto not been observed in the intramolecular photophysics of an isolated anion, raising questions into how common such processes might be, given that many anionic chromophores have bright valence states near the detachment threshold.
| S-EPMC6925192 | biostudies-literature