Ensemble of coupling forms and networks among brain rhythms as function of states and cognition

We acknowledge support from the W. M. Keck Foundation, and the US Israel Binational Science Foundation (BSF Grant 2020020). We also thank Dr. Sergi Garcia-Retortillo for stimulating discussions and helpful comments on the manuscript.The current paradigm in brain research focuses on individual brain rhythms, their spatiotemporal organization, and specific pairwise interactions in association with physiological states, cognitive functions, and pathological conditions. Here we propose a conceptually different approach to understanding physiologic function as emerging behavior from communications among distinct brain rhythms. We hypothesize that all brain rhythms coordinate as a network to generate states and facilitate functions. We analyze healthy subjects during rest, exercise, and cognitive tasks and show that synchronous modulation in the microarchitecture of brain rhythms mediates their cross-communications. We discover that brain rhythms interact through an ensemble of coupling forms, universally observed across cortical areas, uniquely defining each physiological state. We demonstrate that a dynamic network regulates the collective behavior of brain rhythms and that network topology and links strength hierarchically reorganize with transitions across states, indicating that brain-rhythm interactions play an essential role in generating physiological states and cognition.W.M. Keck FoundationUS-Israel Binational Science Foundation 202002

The brain in flow: a systematic review on the neural basis of the flow state

Background: Flow state is a subjective experience that people report when task performance is experienced as automatic, intrinsically rewarding, optimal and effortless. While this intriguing phenomenon is the subject of a plethora of behavioural studies, only recently researchers have started to look at its neural correlates. Here, we aim to systematically and critically review the existing literature on the neural correlates of the flow state. Methods: Three electronic databases (Web of Science, Scopus and PsycINFO) were searched to acquire information on eligible articles in July, 2021, and updated in March, 2022. Studies that measured or manipulated flow state (through questionnaires or employing experimental paradigms) and recorded associated brain activity with electroencephalography (EEG), functional magnetic resonance (fMRI) or functional near-infrared spectroscopy (fNIRS) or manipulated brain activity with transcranial direct current stimulation (tDCS) were selected. We used the Cochrane Collaboration Risk of Bias 2 (RoB 2) tool to assess the methodological quality of eligible records. Results: In total, 25 studies were included, which involved 471 participants. In general, the studies that experimentally addressed flow state and its neural dynamics seem to converge on the key role of structures linked to attention, executive function and reward systems, giving to the anterior brain areas (e.g., the DLPC, MPFC, IFG) a crucial role in the experience of flow. However, the dynamics of these brain regions during flow state are inconsistent across studies. Discussion: In light of the results, we conclude that the current available evidence is sparse and inconclusive, which limits any theoretical debate. We also outline major limitations of this literature (the small number of studies, the high heterogeneity across them and their important methodological constraints) and highlight several aspects regarding experimental design and flow measurements that may provide useful avenues for future studies on this topic.Spanish Government 20CO1/012863Ministry of Science and Innovation, Spain (MICINN) Spanish Government PID2019-105635GBI00Junta de Andalucia DOC_0022

Colección de Trozos Escogidos de los autores clásicos latinos para ejercicios prácticos de lectura, análisis y traducción dispuestos y arreglados con un gran número de notas de interpretación y análisis gramatical

4ª ediciónObra aprobada por el Consejo de Instrucción PúblicaEnc. Hol

Nanometric constrictions in superconducting coplanar waveguide resonators

We report on the design, fabrication and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50 nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing and electron paramagnetic resonance.Comment: 4 pages, 4 figure

Reproducción ovina: factores que influyen y métodos de control

La reproducción de la especie ovina se caracteriza por ser estacional. Si bien las razas que se encuentran en el entorno mediterráneo no presentan una estacionalidad muy marcada, lo cierto es que resulta interesante aplicar métodos para inducir y sincronizar celos con el fin de mejorar la prolificidad, fertilidad y fecundidad. Entre los factores que influyen en la reproducción ovina, se encuentran: el fotoperiodo, la nutrición, el genotipo, la edad, los factores sociales. Los métodos de control de la reproducción de esta especie, pueden ser naturales (efecto macho, flushing), farmacológicos (progesterona, prostaglandinas, melatonina) o mixtos. Por último, se muestra una comparativa de diferentes métodos de control y su efecto sobre la fertilidad y la prolificidad

Transcranial direct current stimulation (tDCS) over the left prefrontal cortex does not affect time-trial self-paced cycling performance: Evidence from oscillatory brain activity and power output

To test the hypothesis that transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) influences performance in a 20-min time-trial self-paced exercise and electroencephalographic (EEG) oscillatory brain activity in a group of trained male cyclists. There were no differences (F = 0.31, p > 0.05) in power output between the stimulation conditions: anodal (235W[95%CI 222–249 W]; cathodal (235W[95%CI 222–248 W] and sham (234W[95%CI 220–248 W]. Neither heart rate, sRPE nor EEG activity were affected by tDCS (all Ps > 0.05). tDCS over the left DLFC did not affect self-paced exercise performance in trained cyclists. Moreover, tDCS did not elicit any change on oscillatory brain activity either at baseline or during exercise. Our data suggest that the effects of tDCS on endurance performance should be taken with caution.This project was supported by grants from from the Spanish Ministerio de Economía, Industria y Competitividad-PSI2016-75956-P to D. S. and M.Z., a predoctoral grant from the Spanish Ministerio de Economía, Industria y Competitividad (BES-2014-069050) to L.F.C., and a Spanish “Ministerio de Educación, Cultura y Deporte” predoctoral grant (FPU14/06229) to D.H. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Antiferromagnetic spin coupling between rare earthadatoms and iron islands probed by spin-polarized tunneling

High-density magnetic storage or quantum computing could be achieved using small magnets with large magnetic anisotropy, a requirement that rare-earth iron alloys fulfill in bulk. This compelling property demands a thorough investigation of the magnetism in low dimensional rare-earth iron structures. Here, we report on the magnetic coupling between 4f single atoms and a 3d magnetic nanoisland. Thulium and lutetium adatoms deposited on iron monolayer islands pseudomorphically grown on W(110) have been investigated at low temperature with scanning tunneling microscopy and spectroscopy. The spin-polarized current indicates that both kind of adatoms have in-plane magnetic moments, which couple antiferromagnetically with their underlying iron islands. Our first-principles calculations explain the observed behavior, predicting an antiparallel coupling of the induced 5d electrons magnetic moment of the lanthanides with the 3d magnetic moment of iron, as well as their in-plane orientation, and pointing to a non-contribution of 4f electrons to the spin-polarized tunneling processes in rare earths.This work was supported by the Spanish MINECO (Grants MAT2010-15659 and MAT2012-31309), Gobierno de Aragón (Grant E81), University of Zaragoza (JIUZ-2013-CIE-12) and Fondo Social Europeo.Peer Reviewe

Antiferromagnetic Spin Coupling between Rare Earth Adatoms and Iron Islands Probed by Spin-Polarized Tunneling

High-density magnetic storage or quantum computing could be achieved using small magnets with large magnetic anisotropy, a requirement that rare-earth iron alloys fulfill in bulk. This compelling property demands a thorough investigation of the magnetism in low dimensional rare-earth iron structures. Here, we report on the magnetic coupling between 4f single atoms and a 3d magnetic nanoisland. Thulium and lutetium adatoms deposited on iron monolayer islands pseudomorphically grown on W(110) have been investigated at low temperature with scanning tunneling microscopy and spectroscopy. The spin-polarized current indicates that both kind of adatoms have in-plane magnetic moments, which couple antiferromagnetically with their underlying iron islands. Our first-principles calculations explain the observed behavior, predicting an antiparallel coupling of the induced 5d electrons magnetic moment of the lanthanides with the 3d magnetic moment of iron, as well as their in-plane orientation, and pointing to a non-contribution of 4f electrons to the spin-polarized tunneling processes in rare earths

The relationship between vigilance capacity and physical exercise: a mixed-effects multistudy analysis

We thank to all the participants who took part in the experiment.The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.A substantial body of work has depicted a positive association between physical exercise and cognition, although the key factors driving that link are still a matter of scientific debate. Here, we aimed to contribute further to that topic by pooling the data from seven studies (N = 361) conducted by our research group to examine whether cardiovascular fitness (VO2), sport type participation (externally-paced (e.g., football or basketball) and self-paced (e.g., triathlon or track and field athletes) vs. sedentary), or both, are crucial factors to explain the association between the regular practice of exercise and vigilance capacity. We controlled for relevant variables such as age and the method of VO2 estimation. The Psychomotor Vigilance Task was used to measure vigilance performance by means of reaction time (RT). The results showed that externally-paced sport practice (e.g., football) resulted in significantly shorter RT compared to self-paced sport (e.g., triathlon) and sedentary condition, depicting larger effects in children and adolescents than in adults. Further analyses revealed no significant effect of cardiovascular fitness and self-paced sport practice, in comparison to the sedentary condition, on RT. Our data point to the relevance of considering the type of sport practice over and above the level of cardiovascular fitness as crucial factor to explain the positive association between the regular practice of exercise and vigilance capacity.This research was supported by a postdoctoral grant from the Spanish “Ministerio de Ciencia, Innovación y Universidades” (FJCI-2016-28405) to Antonio Luque-Casado, predoctoral grants from the Spanish Ministerio de Economía, Industria y Competitividad to Luis F. Ciria (BES-2014-069050), and to Rafael Ballester (FPU13-05605), and research grants from the “Ministerio de Economía, Industria y Competitividad” (PSI2013-46385-P and PSI2016-75956-P) and the “Junta de Andalucía” (SEJ-6414) to Daniel Sanabri