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Optogenetic restoration of neuron subtype-specific cortical activity ameliorates motor deficits in Huntington’s Disease mice
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On the Loss of Orthogonality in Low-Synchronization Variants of Reorthogonalized Block Classical Gram-Schmidt
Get PDFRe-evaluating laminar specificity of working memory in human prefrontal cortex
Get PDFAlthough working memory reliably activates the dorsolateral prefrontal cortex (dlPFC), the functional significance of its distinct cytoarchitectonic layers is not well understood in humans. A recent functional magnetic resonance (fMRI) study at 7T demonstrated for the first time layer-specific responses in the human dlPFC during working memory. Superficial layers were more active during the delay period when working memory items needed to be manipulated compared to mere maintenance. In contrast, deeper layers were more active during the motor response to a probe compared to non-action. Like many current layer fMRI studies, this study relied on several manual and semi-manual processing steps, including the selection of regions of interest. To test the replicability of these findings, we conducted a pre-registered replication of this study in 21 subjects using a fully automated and reproducible analysis pipeline. Our results do not show the same layer-specific effects. Although we observed higher activity in the superficial layers in response to working memory manipulation during the delay period, we did not find any evidence for stronger deep layer involvement during motor response in the probe period. We argue that our results are biologically plausible in light of previous research as well as methodological considerations inherent in layer fMRI acquisition and analysis. Consequently, we conclude that the evidence regarding the functional role of different layers within the human dlPFC during working memory remains inconclusive. A focus on replicability, reproducibility, and a better understanding of the influence of methodological choices will help layer fMRI become a more routine tool in cognitive neuroscience
Cryptocercus genomes expand knowledge of adaptations to xylophagy and termite sociality
No full textSubsociality and wood-eating or xylophagy are understood as key drivers in the evolution of eusociality in Blattodea (cockroaches and termites), two features observed in the cockroach genus Cryptocercus, the sister group of all termites. We analyse two high-quality genomes from this genus, C. punctulatus from North America and C. meridianus from Southeast Asia, to explore the evolutionary transitions to xylophagy and subsociality within Blattodea. Our analyses reveal evidence of relaxed selection in both Cryptocercus and termites, indicating that a reduction in effective population size may have occurred in their subsocial ancestors. These findings challenge the expected positive correlation between dN/dS ratios and social complexity, as Cryptocercus exhibits elevated dN/dS values that may exceed those of eusocial termites. Additionally, we infer a reduction in the number of Ionotropic Receptors and a change from uni- to bimodal methylation signatures in protein coding genes in a common ancestor of Cryptocercus and termites, mechanisms previously thought to have evolved with the emergence of eusociality in termites. Future studies incorporating additional genomic data from diverse blattodean species can further build on these findings and provide deeper insights into the molecular mechanisms driving transitions to xylophagy and eusociality
Sidi Zin Archaeological Project: new investigations into the Acheulean and Middle Stone Age in Tunisia
No full textThe Sidi Zin Archaeological Project aims to bridge understanding of the Acheulean–Middle Stone Age transition in northern Tunisia, a relatively understudied region in the context of hominin evolution. The Sidi Zin locality will provide chronological, palaeoenvironmental, geomorphological and cultural insights into Acheulean and Middle Stone Age occupations in Tunisia.Introduction Re-assessing the potential of the Sidi Zin locality Materials recovered in 2022 Future direction
Self-Dual Electrodynamics via the Characteristic Method: Relativistic and Carrollian Perspectives
Get PDFElectric-magnetic duality plays a pivotal role in understanding the structureof nonlinear electrodynamics (NED). The Gaillard-Zumino (GZ) criterion providesa powerful constraint for identifying self-dual theories. In this work, wesystematically explore solutions to the GZ self-duality condition by applyingthe method of characteristics, a robust tool for solving nonlinear partialdifferential equations. Our approach enables the construction of new classes ofLagrangians that respect duality symmetry, both in the relativistic andCarrollian frameworks. In the relativistic setting, we not only recoverwell-known examples such as Born-Infeld and ModMax theories, but also identifynovel models. We then generalize the GZ formalism to the Carrollian case andconstruct several classes of Carrollian self-dual non-linear electrodynamicmodels. Remarkably, we demonstrate that the characteristic flow exhibits anattractor behavior, in the sense that different seed theories that may not beself-dual can generate the same descendant self-dual Lagrangian. These findingsbroaden the landscape of self-dual theories and open new directions forexploring duality in ultra-relativistic regimes.<br
