Adaptive cortical parcellations for source reconstructed EEG/MEG connectomes.

There is growing interest in the rich temporal and spectral properties of the functional connectome of the brain that are provided by Electro- and Magnetoencephalography (EEG/MEG). However, the problem of leakage between brain sources that arises when reconstructing brain activity from EEG/MEG recordings outside the head makes it difficult to distinguish true connections from spurious connections, even when connections are based on measures that ignore zero-lag dependencies. In particular, standard anatomical parcellations for potential cortical sources tend to over- or under-sample the real spatial resolution of EEG/MEG. By using information from cross-talk functions (CTFs) that objectively describe leakage for a given sensor configuration and distributed source reconstruction method, we introduce methods for optimising the number of parcels while simultaneously minimising the leakage between them. More specifically, we compare two image segmentation algorithms: 1) a split-and-merge (SaM) algorithm based on standard anatomical parcellations and 2) a region growing (RG) algorithm based on all the brain vertices with no prior parcellation. Interestingly, when applied to minimum-norm reconstructions for EEG/MEG configurations from real data, both algorithms yielded approximately 70 parcels despite their different starting points, suggesting that this reflects the resolution limit of this particular sensor configuration and reconstruction method. Importantly, when compared against standard anatomical parcellations, resolution matrices of adaptive parcellations showed notably higher sensitivity and distinguishability of parcels. Furthermore, extensive simulations of realistic networks revealed significant improvements in network reconstruction accuracies, particularly in reducing false leakage-induced connections. Adaptive parcellations therefore allow a more accurate reconstruction of functional EEG/MEG connectomes

Multichannel single center method

Gefördert im Rahmen eines Open-Access-Transformationsvertrags mit dem Verla

Nondipolar photoelectron angular distributions from fixed-in-space N₂ molecules

We investigate experimentally and theoretically the N2 1s photoionization of fixed-in-space N molecules at a photon energy of 880 eV. In our experiment, we employed circularly polarized synchrotron radiation for the photoionization and coincident electron and fragment-ion detection using cold target recoil ion momentum spectroscopy. The accompanying angle-resolved calculations were carried out by the multichannel single-center method and code within the frozen-core Hartree–Fock approximation. The computed emission distributions exhibit two distinct features along the molecular axis, which are the results of a superposition of the direct and nearest-neighbor scattering amplitudes for the photoemission from two nitrogen atoms. In the electric-dipole approximation, these peaks are symmetric with respect to both nitrogen atoms. Including nondipole (retardation) effects in the calculations results in a simultaneous increase and decrease of the scattering peaks towards the nitrogen atoms pointing in the forward and backward directions along the light propagation, respectively. These theoretical findings are in agreement with our experimental findings

Formation of vacuum electronics elements by a combination of methods of focused ion beams and plasma layer etching on SiC

This work was supported by Grant of the President of the Russian Federation No. МК-3512.2019.8 and Southern Federal University (grant VnGr-07/2017-02). The results were obtained using the equipment of the Research and Education Center "Nanotechnologies" of Southern Federal University

Electroencephalographic localization of pathological activity areas in dynamics in patients with benign age-dependent focal epilepsy

Genetic focal age-dependent epilepsy accounts for 25% of epilepsy in children with non-febrile seizures and is a genetically determined focal pathology. The main pattern of interictal pathological activity include benign epileptiform discharges of childhood from the centrotemporal leads in patients with rolandic epilepsy and discharges from the posterior parietooccipital leads in patients with occipital epilepsy. We followed-up 72 patients with benign agedependent focal epilepsy aged 6 months to 10 years for a year to assess the electroencephalographic location of pathological activity areas in dynamics. Electroencephalography demonstrated a variety of locations of pathological activity both at disease onset and after one year of follow-up, as well as migration of this activity, regardless of age, gender, and therapy

Multi-antigen Intranasal Vaccine Protects Against Challenge With Sarbecoviruses and Prevents Transmission in Hamsters

Immunization programs against SARS-CoV-2 with commercial intramuscular vaccines prevent disease but are less efficient in preventing infections. Mucosal vaccines can provide improved protection against transmission, ideally for different variants of concern (VOCs) and related sarbecoviruses. Here, we report a multi-antigen, intranasal vaccine, NanoSTING-SN (NanoSTING-Spike-Nucleocapsid), eliminates virus replication in both the lungs and the nostrils upon challenge with the pathogenic SARS-CoV-2 Delta VOC. We further demonstrate that NanoSTING-SN prevents transmission of the SARS-CoV-2 Omicron VOC (BA.5) to vaccine-naïve hamsters. To evaluate protection against other sarbecoviruses, we immunized mice with NanoSTING-SN. We showed that immunization affords protection against SARS-CoV, leading to protection from weight loss and 100% survival in mice. In non-human primates, animals immunized with NanoSTING-SN show durable serum IgG responses (6 months) and nasal wash IgA responses cross-reactive to SARS-CoV-2 (XBB1.5), SARS-CoV and MERS-CoV antigens. These observations have two implications: (1) mucosal multi-antigen vaccines present a pathway to reducing transmission of respiratory viruses, and (2) eliciting immunity against multiple antigens can be advantageous in engineering pan-sarbecovirus vaccines

Investigating charge-up and fragmentation dynamics of oxygen molecules after interaction with strong X-ray free-electron laser pulses

During the last decade, X-ray free-electron lasers (XFELs) have enabled the study of light–matter interaction under extreme conditions. Atoms which are subject to XFEL radiation are charged by a complex interplay of (several subsequent) photoionization events and electronic decay processes within a few femtoseconds. The interaction with molecules is even more intriguing, since intricate nuclear dynamics occur as the molecules start to dissociate during the charge-up process. Here, we demonstrate that by analyzing photoelectron angular emission distributions and kinetic energy release of charge states of ionic molecular fragments, we can obtain a detailed understanding of the charge-up and fragmentation dynamics. Our novel approach allows for gathering such information without the need of complex ab initio modeling. As an example, we provide a detailed view on the processes happening on a femtosecond time scale in oxygen molecules exposed to intense XFEL pulses