Reduced frequency noise in superconducting resonators

We report a reduction of the frequency noise in coplanar waveguide superconducting resonators. The reduction of 7 dB is achieved by removing the exposed dielectric substrate surface from the region with high electric fields and by using NbTiN. In a model-analysis the surface of NbTiN is found to be a negligible source of noise, experimentally supported by a comparison with NbTiN on SiOx resonators. The reduction is additive to decreasing the noise by widening the resonators.Comment: 4 pages, 4 figure

Epitaxial aluminium-nitride tunnel barriers grown by nitridation with a plasma source

High critical current-density (10 to 420 kA/cm^2) superconductor-insulator-superconductor tunnel junctions with aluminium nitride barriers have been realized using a remote nitrogen plasma from an inductively coupled plasma source operated in a pressure range of 10^{-3} to 10^{-1} mbar. We find a much better reproducibility and control compared to previous work. From the current-voltage characteristics and cross-sectional TEM images it is inferred that, compared to the commonly used AlO_x barriers, the poly-crystalline AlN barriers are much more uniform in transmissivity, leading to a better quality at high critical current-densities.Comment: 3 pages, 3 figures, accepted for publication in AP

Evanescent states and nonequilibrium in driven superconducting nanowires

We study the nonlinear response of current transport in a superconducting diffusive nanowire between normal reservoirs. We demonstrate theoretically and experimentally the existence of two different superconducting states appearing when the wire is driven out of equilibrium by an applied bias, called the global and bimodal superconducting states. The different states are identified by using two-probe measurements of the wire, and measurements of the local density of states with tunneling probes. The analysis is performed within the framework of the quasiclassical kinetic equations for diffusive superconductors.Peer reviewe

Referential Choices in a Collaborative Storytelling Task: Discourse Stages and Referential Complexity Matter

During a narrative discourse, accessibility of the referents is rarely fixed once and for all. Rather, each referent varies in accessibility as the discourse unfolds, depending on the presence and prominence of the other referents. This leads the speaker to use various referential expressions to refer to the main protagonists of the story at different moments in the narrative. This study relies on a new, collaborative storytelling in sequence task designed to assess how speakers adjust their referential choices when they refer to different characters at specific discourse stages corresponding to the introduction, maintaining, or shift of the character in focus, in increasingly complex referential contexts. Referential complexity of the stories was manipulated through variations in the number of characters (1 vs. 2) and, for stories in which there were two characters, in their ambiguity in gender (different vs. same gender). Data were coded for the type of reference markers as well as the type of reference content (i.e., the extent of the information provided in the referential expression). Results showed that, beyond the expected effects of discourse stages on reference markers (more indefinite markers at the introduction stage, more pronouns at the maintaining stage, and more definite markers at the shift stage), the number of characters and their ambiguity in gender also modulated speakers' referential choices at specific discourse stages, For the maintaining stage, an effect of the number of characters was observed for the use of pronouns and of definite markers, with more pronouns when there was a single character, sometimes replaced by definite expressions when two characters were present in the story. For the shift stage, an effect of gender ambiguity was specifically noted for the reference content with more specific information provided in the referential expression when there was referential ambiguity. Reference content is an aspect of referential marking that is rarely addressed in a narrative context, yet it revealed a quite flexible referential behavior by the speakers

Utilisation of far infrared-emitting garments for optimising performance and recovery in sport: Real potential or new fad? A systematic review

Background Thanks to the specific materials they embed, far infrared (FIR)-emitting garments can interact with the body’s physiological functions. Such effects have been sought in medicine and physiotherapy for a long time for the treatment/relief of a variety of pathologies and disabling conditions. Recently, FIR-emitting garments have been introduced in the sporting domain under the influence of manufacturers seeing here a new opportunity to support physical performance in athletes, though this is not clearly established. To fill this gap, in this systematic review, we summarize the scientific evidence on the use of FIR-emitting garments in sport and provide directions for future research by shedding light on current scientific limitations. Method Five scientific databases (PubMed, Cochrane, ScienceDirect, Scopus and SPORTDiscus) were searched by two independent reviewers. Studies investigating the effects of FIR-emitting garments on at least one physiological outcome related to exercise performance and/or recovery in humans were selected. The methodological quality of retained studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. Results and discussion Eleven studies met the inclusion criteria and were included in the systematic review. Studies investigating similar outcomes related to exercise performance or recovery were scarce and results inconclusive, which prevents from drawing firm conclusion about the utilisation of FIR-emitting garments in athletes. However, these early results show that FIR-emitting garments may be of interest for exercise performance and recovery, mainly through their effects on the body’s thermoregulation and haemodynamic function. The summary provided in this review can be used to inform the design of future studies. (PROSPERO registration number: CRD42021238029)

Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review

Downhill running (DR) is a whole-body exercise model that is used to investigate the physiological consequences of eccentric muscle actions and/or exercise-induced muscle damage (EIMD). In a sporting context, DR sections can be part of running disciplines (off-road and road running) and can accentuate EIMD, leading to a reduction in performance. The purpose of this narrative review is to: (1) better inform on the acute and delayed physiological effects of DR; (2) identify and discuss, using a comprehensive approach, the DR characteristics that affect the physiological responses to DR and their potential interactions; (3) provide the current state of evidence on preventive and in-situ strategies to better adapt to DR. Key findings of this review show that DR may have an impact on exercise performance by altering muscle structure and function due to EIMD. In the majority of studies, EIMD are assessed through isometric maximal voluntary contraction, blood creatine kinase and delayed onset muscle soreness, with DR characteristics (slope, exercise duration, and running speed) acting as the main influencing factors. In previous studies, the median (25th percentile, Q1; 75th percentile, Q3) slope, exercise duration, and running speed were − 12% (− 15%; − 10%), 40 min (30 min; 45 min) and 11.3 km h−1 (9.8 km h−1; 12.9 km h−1), respectively. Regardless of DR characteristics, people the least accustomed to DR generally experienced the most EIMD. There is growing evidence to suggest that preventive strategies that consist of prior exposure to DR are the most effective to better tolerate DR. The effectiveness of in-situ strategies such as lower limb compression garments and specific footwear remains to be confirmed. Our review finally highlights important discrepancies between studies in the assessment of EIMD, DR protocols and populations, which prevent drawing firm conclusions on factors that most influence the response to DR, and adaptive strategies to DR

Editorial: From Physiological Adaptations to Endurance Performance: It Is Time to Bridge the Gap

Editorial on the Research Topic From Physiological Adaptations to Endurance Performance: It Is Time to Bridge the Ga

Biomechanical Analysis of Postural Sway in Elderly Adults on Ramps

This study investigated the effects of ramp angles on postural deviation as a function of age. Five ramp inclinations (1:8, 1:10, 1:12, 1:16, and 1:20) were examined in both ascent and descent directions. Five younger (22 to 28 years) and five older (78 to 88 years) adults participated in the study. Video-based motion analysis was used to measure torso and hip angles while participants walked on an adjustable inclined ramp. Both young and older participants had a significant increase in torso angle across ramp slopes from ascent to descent. In addition, the data indicated that older participants tended to lean to the right while walking while the young participants leaned to the left. Measurements of hip angle revealed that young participants had significantly greater hip movement than older participants and that hip angle decreased significantly as participants transitioned from descent to ascent trials. Based on the data observed, it is possible that ramp descent is more problematic for elderly adults. However, within the ramp conditions evaluated, the data were unable to clearly discriminate between ramp slopes beyond identifying differences between slopes of ascent and descent.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline