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Holographic Duals of Symmetry Broken Phases
No full textA novel interpretation of Symmetry Topological Field Theories (SymTFTs) as theories of gravity is explored by proposing a holographic duality where the bulk SymTFT (with the gauging of a suitable Lagrangian algebra) is dual to the universal effective field theory (EFT) that describes spontaneous symmetry breaking on the boundary. The authors tested this conjecture in various dimensions and with many examples involving different continuous symmetry structures, including non-Abelian and non-invertible symmetries, as well as higher groups. For instance, many Abelian SymTFTs are found to be dual to free theories of Goldstone bosons or generalized Maxwell fields, while non-Abelian SymTFTs relate to non-linear sigma models with target spaces defined by the symmetry groups. The analysis is also extended to include the non-invertible Q/Z axial symmetry, which is shown to be dual to axion-Maxwell theory, and a non-Abelian 2-group structure in four dimensions, deriving a new parity-violating interaction that has implications for the low-energy dynamics of U(N) QCD
K-stability and large complex structure limits
No full textWe discuss how, under suitable assumptions, a K ̈ahler test configuration admits a mirror Landau-Ginzburg model, giving a corresponding expression for the Donaldson-Futaki invariant as a residue pairing. We study the general behaviour of such mirror formulae under large scaling of the K ̈ahler form. We exploit the observation that this scaling trivially preserves K-stability, but takes the mirror Landau-Ginzburg model to a large complex structure limit. In certain cases the mirror formulae for the Donaldson-Futaki invariant simplify in this limit. We focus on a special type of limiting behaviour, when the Donaldson-Futaki invariant concentrates at a single critical point of the Landau-Ginzburg potential, and show that this leads to new formulae for the Donaldson-Futaki invariant in terms of theta functions on the mirror. We provide a main application, which shows that such limiting behaviour actually occurs for test configurations in several nontrivial examples, both toric and non-toric, in the case of slope (in)stability for polarised surfaces
Immediate cortical glial alterations following spinal cord injury: Evidence from a novel in vitro model
No full textSpinal cord injury (SCI) triggers immediate and widespread pathophysiological changes not only at the site of impact but also beyond it, including alterations in remote cortical regions. Here, we report early astrocytic changes in the cerebral cortex following SCI at birth, identified using two specific glial markers in an innovative in vitro model of the entire central nervous system (CNS) isolated from neonatal rats. Immunohistochemical analyses revealed a significant reduction in cortical astrocyte density, first observed in the dorsomedial motor cortex (M1) within 25 min post-injury, followed by progressive changes in the ventrolateral somatosensory cortex (S1/S2) at 2 h post-injury. These findings indicate that SCI initiates a rapid and dynamic reorganization of cortical glial networks, shedding new light on astrocytic responses to spinal trauma
Eye-voice and finger-voice spans in adults’ oral reading of connected texts
No full textThe present paper investigates the interaction between eye movements, voice articulation and the movements of the index finger dynamically pointing to a text line in oral finger-point reading of Italian. During finger-point reading, the finger appears to be ahead of the voice most of the times, by a margin that is significantly modulated by the distribution of phrasal and prosodic units in the reading text. Eye movements replicate the same effects on a different time scale. The eye is ahead of both voice and finger by a wide margin (confirming evidence observed for English and German sentence reading), while showing a tendency to re-synchronise with voice articulation at the right edge of strong prosodic units (sentence boundaries). Our evidence suggests a multicomponent view of the time span between the eye/finger and the voice. The span is shown to be the dynamic outcome of an optimally adaptive reading strategy, resulting from the interaction between individual decoding skills, the reader’s phonological buffer capacity, and the structural complexity of a reading text. Proficient readers modulate their span to compensate for the different timing between word fixation and word articulation, read faster, and dynamically adjust their processing window to the meaningful, prosodic units of a text
Impaired processing of conspecifics in Parkinson’s disease
No full textExperimental evidence indicates that the inferior frontal gyrus (IFG) processes emotional/affective features crucial to elaborate knowledge about social groups and that knowledge of social concepts is stored in the anterior temporal lobe (ATL). We investigated whether knowledge about social groups is impaired in Parkinson's disease (PD), in which dysfunctional connectivity between IFG and ATL has been demonstrated. PD patients (N = 20) and healthy controls (HC, N = 16) were given a lexical decision task in a semantic priming paradigm: the prime-targets included 144 words and 144 pseudowords, each preceded by three types of prime ("animals," "things," "persons"). Out of these 288 prime-targets, forty-eight were congruent (same category) and 96 incongruent (different category). Out of 48 congruent prime-targets, 24 denoted social items and 24 nonsocial items. Thus, four types of trials were obtained: congruent social; congruent nonsocial; incongruent social; incongruent nonsocial. Congruent target-words were recognized better than incongruent target-words by all groups. The semantic priming effect was preserved in PD; however, accuracy was significantly lower in PD than in HC in social items. No difference emerged between the two groups in nonsocial items. Impaired processing of words denoting social groups in PD may be due to impairment in accessing the affective/emotional features that characterize conceptual knowledge of social groups, for the functional disconnection between the IFG and the ATL