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Abstract Space analog research has increased over the last few years with new analogs appearing every year. Research in this field is very important for future real mission planning, selection and training of astronauts. Analog environments offer specific characteristics that resemble to some extent the environment of a real space mission. These analog environments are especially interesting from the psychological point of view since they allow the investigation of mental and social variables in very similar conditions to those occurring during real space missions. Analog missions also represent an opportunity to test operational work and obtain information on which combination of processes and team dynamics are most optimal for completing specific aspects of the mission. A group of experts from a European Space Agency (ESA) funded topical team reviews the current situation of topic, potentialities, gaps, and recommendations for appropriate research. This review covers the different domains in space analog research including classification, main areas of behavioral health performance research in these environments and operational aspects. We also include at the end, a section with a list or tool of recommendations in the form of a checklist for the scientific community interested in doing research in this field. This checklist can be useful to maintain optimal standards of methodological and scientific quality, in addition to identifying topics and areas of special interest.

The aims of this study were: (a) to explore the relationships between adaptive defense mechanisms (ADMs), maladaptive defense mechanisms (MADMs), stress, recovery, resilience, and sport burnout; and (b) to examine resilience, stress, and recovery as mediators of the relationship between defense mechanisms and burnout. One hundred and seventy-five athletes (M = 20.30 years, SD = 3.75) completed self-report questionnaires assessing defense mechanisms, resilience, stress, and recovery. Correlation analysis revealed that MADMs were positively associated with burnout, while ADMs had no significant link with burnout. Concerning mediation analysis, results showed a mediating effect of resilience in the relationship between ADMs and burnout. The findings also demonstrated a mediating effect of resilience and recovery in the relationship between MADMs and burnout. Our study highlighted that certain defenses categorized as adaptive might not be suitable in specific situations, thus underscoring the influence of mediating variables. The findings of mediation analysis demonstrated that resilience appears to serve as a particularly protective factor against burnout. On the contrary, MADMs would have a deleterious influence in the management of stress, which could lead to burnout. Coaches may consider fostering athletes’ resilience in conjunction with ADMs and implementing targeted psychological exercises to reduce the use of MADMs.

This study examined the effect of a Slow-Paced Breath (i.e., 6 breaths per minute) without Biofeedback (SPB-NoHRVB) protocol on semi-elite adolescent swimmers’ psychological and physiological states during a seven-week ecological training period. A linear mixed-effects multilevel regression analysis approach was used with 13 adolescent national-level swimmers. Athletes were randomly assigned to an intervention group (n = 7) and a control group (n = 6). Seven waves of assessments were completed weekly during a seven-week training preparation in ecological conditions. During the protocol, swimmers completed subjective quantitative measures (RESTQ-36-R-Sport; cognitive perceived stress and control states about the training process, training subjective performance, and subjective internal training load) and physiological heart rate (HR) (HR of exercise, absolute and normalized HR recovery during the first 60 s of recovery; HRR60 and nHRR60) and heart rate variability (HRV) (MeanRR, RMSSD, LFnu and HFnu, LF/HF ration) tests (through a submaximal heart rate (5′-5′ test) once a week. Results revealed that the SPB-NoHRVB protocol significantly predicts biopsychosocial recovery states, cognitive perception of control, and training subjective performance (i.e., a significant effect of the SPB-NoHRVB protocol with the dependent variables simple time trajectories). However, no significant effects were found for biopsychosocial stress scales, cognitively perceived stress, HR, or HRV markers. Our results suggest that SPB-NoHRVB induces simple evolutions over time for crucial variables in athletes’ adaptation to the training process (i.e., cognitive appraisals and biopsychosocial states). In contrast, it highlights that SPB-NoHRVB does not induce better stress states. This specific effect on the resource component is an exciting result that will be discussed in the manuscript.

The open quantum system eigenstate in the vicinity of low-energy decay channel may mimic its features, in particular the characteristic clustering properties of the decay channel. This generic mechanism of clusterization, the so-called mimicry mechanism of clusterization, is discussed here on example of the ground state wave function of 8Be. At higher excitation energies, when the density of states and reaction channels is high, the quantal aspects in the clusterization process disappear and the statistical mechanism of clusterization which is rooted in the Central Limit Theorem, begin to dominate.

This study examined the effect of an asynchronous heart rate variability biofeedback (HRV-BFBasync) protocol on national-level adolescent swimmers’ cognitive appraisals and recovery-stress states during a six-week ecological training period. A polynomial mixed-effects multilevel regression analysis approach was used with 27 adolescent national-level swimmers randomly assigned to an intervention group (n = 14) and a control group (n = 13). Six waves of assessments of cognitive appraisals and recovery-stress states were completed during six weeks of training preparation in ecological conditions. The results revealed that the HRV-BFBasync protocol significantly predicts lower levels of biopsychosocial stress states and cognitive stress. However, no significant effects were found for biopsychosocial recovery scales and cognitive perceived control. The results suggested that total stress states, sport-specific stress, and cognitive perceived stress evolutions are a function of polynomial time third-degree interactions with HRV-BFB protocol. Overall, this study suggested that the HRV-BFBasync protocol leads adolescent athletes to experience lower biopsychosocial and cognitive stress levels during training periodization. Our results also suggest that HRV-BFB induces complex evolutions over time for stress and recovery states but does not have a predictive function for the recovery states and perceived control.

Background: Psychological stress and recovery monitoring is a key issue for increasing athletes' health, well-being, and performance. This multi-study report examined changes and the dose–response relationships between recovery–stress psychological states, training load (TL), heart rate (HR), heart rate recovery (HRR), and heart rate variability (HRV) while providing evidence for the factorial validity of a short French version of the Recovery–Stress Questionnaire for Athletes (RESTQ-36-R-Sport). Methods: Four hundred and seventy-three university athletes (Study 1), 72 full expert swimmers (Study 2), and 11 national to international swimmers (Study 3) participated in the study. Data were analyzed through confirmatory factor analyses (Study 1), repeated ANOVAs and correlational analyses (Study 2), t tests and correlational analyses (Study 3). Results: Multiple-group confirmatory factor analyses showed that the RESTQ-36-R-Sport scores were partially invariant across gender, type of sport, and practice level (Study 1). A dose–response relationship was performed between TL and RESTQ-36-R-Sport scores during an ecological training program (Study 2). Finally, relationships were found between physiological (HRR) and psychological (RESTQ-36-R-Sport) states during an ecological tapering period leading to a national championship (Study 3). Conclusion: As a whole, these findings provided evidence for the usefulness of the short version of the RESTQ-36-R-Sport for regular monitoring to prevent potential maladaptation due to intensive competitive sport practice. Keywords: Adaptation, Confirmatory factor analysis, Heart rate variability, Monitoring, Recovery, Stress

The data presented in this article relate to the research article entitled “assessing psychological adaptation during polar winter-overs: The isolated and confined environments questionnaire (ICE-Q)” [1]. These data were acquired in order to develop a standardized instrument – the ICE-Q – designed to assess psychological adaptation within isolated, confined, and extreme environments. A total of 140 winterers from several sub-Antarctic (Amsterdam, Crozet, Kerguelen) and Antarctic (Concordia, Terre Adélie) stations voluntarily participated. Data were collected by multiple self-report questionnaires including a wide variety of well-known and validated questionnaires to record the winterers’ responses to polar stations. Data were gathered across two or three winter seasons within each of the 5 polar stations to ensure sufficiently large sample. From four to seven measurement time along a one-year period were proposed to the participants, resulting in 479 momentary assessments. Results of exploratory factor analyses, confirmatory factor analyses, exploratory structural equation modelling, reliability analyses, and test-retest provided strong evidence for the construct validity of the ICE-Q (19–item 4-factor questionnaire). The four factors were social, emotional, occupational and physical. Future studies would examine the dynamic of psychological adaptation in isolated, confined and/or extreme environments during polar missions. Keywords: Emotional changes, Extreme environment, Isolated and confined environment, Occupational investment, Physical fatigue, Polar stations, Psychological adaptation, Social relationships

Given the positive influence of emotional intelligence (EI) on sports performance, particular attention should be paid on how to improve it. Following promising results, previous research concluding that it was possible to improve EI via specific training programs also raised considerable debates. Indeed, previous EI training programs were very time-consuming for participants. This lessens consequently their suitability with the schedule constraints of elite sport. While, in the absence of sport psychologists, numerous coaches or physiologists try to work with players to improve their emotional competences, the aim of this study was to investigate the effectiveness of EI training programs fitting the schedule constraints of elite team sports, provided by three different EI trainers: the team’s coach, the team’s physiotherapist, and an expert in sport psychology. Young elite rugby union players (N = 96) participated in this study. Based on schedule constraints imposed by the head coach of the French u18 rugby union national team, the program consisted in three 1 h group-based EI training sessions occurring the last 3 days before a game (1 per day). Linear mixed-effects models showed that despite the constraining organizational challenge imposed by the coach, the intervention helped the players to increase some emotional competences at the trait level. Furthermore, a pairwise analysis showed that the type of emotional competencies developed depended on the status of the EI trainers. These findings highlight the suitability of a group-based approach in the training-week structure. They also point the way to EI improvement in a short period of time. Moreover, the specific influences of the EI trainer’s status on players’ EI development invite coaches and researchers to jointly combine their efforts in order to increase the EI training opportunities and to maximize the effects of their interventions. Together, these preliminary results provide first evidence facilitating the integration of such work in the preparation periods during international seasons.

Confinement experiments are essential to prepare long-term space exploration. The 180-day Chinese CELSS (Controlled Ecological Life Support System) study is unique in its design, including a closed-loop system and mid-mission simulation of Mars-like day–night cycle of 24 h 40 min for 36 days (days 72–108). Our aim was to study physiological and psychological consequences of this confinement in four healthy volunteers (one female). CELSS platform consisted of six interconnected modules including four greenhouses. Life support systems were controlled automatically. Body composition, fluid compartments, metabolic state, heart, large vessels, endothelial function, and muscle tone were studied using biological, functional, and/or morphological measurements. Behavioral activities were studied by ethological monitoring; psychological state was assessed by questionnaires. Body weight decreased by ∼2 kg mostly due to lean mass loss. Plasma volume and volume-regulating hormones were mostly stable. Carotid intima-media thickness (IMT) increased by 10–15%. Endothelium-dependent vasodilation decreased. Masseter tone increased by 6–14% suggesting stress, whereas paravertebral muscle tone diminished by 10 ± 6%. Behavioral flow reflecting global activity decreased 1.5- to 2-fold after the first month. Psychological questionnaires revealed decrease in hostility and negative emotions but increase in emotional adaptation suggesting boredom and monotony. One subject was clearly different with lower fitness, higher levels of stress and anxiety, and somatic signs as back pain, peak in masseter tone, increased blood cortisol and C-reactive protein. Comparison of CELSS experiment with Mars500 confinement program suggests the need for countermeasures to prevent increased IMT and endothelial deconditioning. Daily activity in greenhouse could act as countermeasure against psycho-physiological deconditioning.

The purpose of this study was to identify the potentially distinct defense profiles of athletes in order to provide insight into the complex associations that can exist between defenses and other important variables tied to performance in sports (e.g., coping, perceived stress and control) and to further our understanding of the complexity of the adaptation process in sports. Two hundred and ninety-six (N = 296) athletes participated in a naturalistic study that involved a highly stressful situation: a sports competition. Participants were assessed before and after the competition. Hierarchical cluster analysis and a series of MANOVAs with post hoc comparisons indicated two stable defense profiles (high and low defense profiles) of athletes both before and during sport competition. These profiles differed with regards to coping, stress and control. Athletes with high defense profiles reported higher levels of coping strategies, perceived stress and control than athletes with low defense profiles. This study confirmed that defenses are involved in the psychological adaptation process and that research and intervention should not be based only on coping, but rather must include defense mechanisms in order to improve our understanding of psychological adaptation in competitive sports.

This study examined the trajectories of emotional states and their within-person synergies with perceived stress and recovery during a 4-month training period preceding the French swimming championships. A Multilevel Growth Curve Analysis approach was used with 16 high level swimmers. Five waves of assessments of emotional states, perceived stress and recovery were completed. Results indicated that emotional states were characterized by distinct trajectories during the training period preceding a major competition. Specifically, significant positive linear effects of time (i.e., linear increase over time) and negative quadratic effects of squared time (i.e., inverted U shape over time) on anxiety, dejection and anger were observed, whereas the opposite pattern of results was found for happiness and excitement. Moreover, level 2 perceived stress and recovery (i.e., inter-individual predictors) were significantly associated with athletes’ unpleasant and pleasant emotional states respectively. At level 1, perceived recovery (i.e., intra-individual predictor) was positively associated with happiness and excitement and negatively related to anxiety, dejection and anger. Finally, within-person interactions of general stress and recovery with time and squared time reached significance for excitement, whereas within-person interactions of specific and total stress with time and squared time reached significance for anxiety. Overall, this study provided insights into the central role played by perceived stress and recovery on the emotional states experienced by high level swimmers. Operational strategies were suggested in order to optimize the stress-recovery balance and in turn the athletes’ emotional states during a complete training program.

Regrown Ohmic contacts have been widely studied for high millimeter-wave applications. However, few were applied to InAl(Ga)N-based HEMT despite the lattice match benefits with GaN channel because of the poor thermal stability of the quaternary barrier. In this article, we use relatively low temperature (850 °C) MOVPE technique for the regrowth of heavily Si doped GaN (1 × 1020 cm−3) to avoid deterioration of the channel's electrical characteristics. Moreover, high selectivity of the regrowth is obtained, thanks to large opening ratio of the hard mask. The state-of-the-art total Ohmic contact resistance Rc = 0.06 Ω mm is reached with high homogeneity on a 4-in. wafer. This result reflects the combined contribution of the doped GaN interfaces with both the metal contact and the channel. 2 × 50 μm transistors featuring 100 nm gate length with regrown Ohmic contacts present remarkable improvements of DC and RF performances. At 40 GHz, the highest Power Added Efficiency (PAE) of 54% is attained at an output power of 3.8 W mm−1, while the maximum output power of 9.4 W mm−1 is achieved at a PAE of 48%, corresponding to bias voltages of 15 and 30 V, respectively. [ABSTRACT FROM AUTHOR]

The quaternary barrier InAlGaN is suitable for GaN high‐electron‐mobility transistors (HEMT) power microwave applications. High doping of the semiconductor under the drain and source is a known suitable solution to achieve low ohmic contact resistance. However, InAlGaN quaternary alloys require a low thermal budget to avoid indium desorption from the active layer during regrowth and thus deteriorating the barrier. Herein, a selective‐area growth technique at 850 °C by metal–organic vapor‐phase epitaxy (MOVPE) to achieve low contact resistance with respect to temperature constraint is presented. Regrowth temperature and mask geometry are investigated to achieve selectivity and control of the regrowth rate. The use of H2 as carrier gas decomposes the GaN buffer layer and damages the surface, creating material cluster during regrowth. Growth with N2 carrier gas shows nonselective epitaxy, as there are deposits on the entire surface of the dielectric mask. Switching from one carrier gas to another depending on the step in the MOVPE reactor helps to control both the morphology and selectivity. The resulting high doping levels of 8 × 1019 cm−3 lead to a low contact resistance of 0.26 Ω mm. [ABSTRACT FROM AUTHOR]

Electric vertical-take-off-and-landing multirotor aircraft has been emerging as a revolutionary transportation mode for both manned and unmanned applications, but this technology is limited by flight time and range restrictions. In this work, an energy-efficient model-based trajectory planning and feedback control framework is developed to improve the energy performance of a multirotor unmanned aerial vehicle. Target vehicle trajectories are planned by solving a formulated energy consumption optimization problem based on a system-level model, which accommodates the integrated dynamics of key vehicle subsystems. In order to implement the generated target trajectories, the framework also includes a PID feedback control architecture for real-time trajectory following. The framework is first verified under simulation, and shows an average reduction of 10.7% in energy consumption over a range of typical hover-to-hover operations, compared to the commonly used baseline flight control architecture. Through model-based analysis, key relationships that contribute to the improvements are identified and analyzed. These results demonstrate the importance of considering and coordinating all relevant system dynamics for efficient and holistic trajectory planning and control, which is absent in existing literature. The framework also demonstrates similar performance improvement under experimental validation, with an average energy reduction of 10.2% over the baseline controller despite the presence of significant real-world disturbances including wind effect. [ABSTRACT FROM AUTHOR]

Of Euclid's lost manuscripts, few have elicited as much scholarly attention as the Porisms , of which a couple of brief summaries by late-Antiquity commentators are extant. Despite the lack of textual sources, attempts at restoring the content of this absent volume became numerous in early-modern Europe, following the diffusion of ancient mathematical manuscripts preserved in the Arabic world. Later, one similar attempt was that of French geometer Michel Chasles (1793–1880). This paper investigates the historiographical tenets and practices involved in Chasles' restoration of the porisms, as well as the philosophical and mathematical claims tentatively buttressed therewith. Echoes of the Quarrel of the Ancients and the Moderns, and of a long-standing debate on the authority and usefulness of the past, are shown to have decisively shaped Chasles' enterprise—and, with it, his integration of mathematical and historical research. [ABSTRACT FROM AUTHOR]

The Gamow shell model (GSM) is a powerful method for the description of the exotic properties of drip line nuclei. Internucleon correlations are included via a configuration interaction framework. Continuum coupling is directly included at basis level by using the Berggren basis, in which, bound, resonance, and continuum single-particle states are treated on an equal footing in the complex momentum plane. Two different types of Gamow shell models have been developed: its first embodiment is that of the GSM defined with phenomenological nuclear interactions, whereas the GSM using realistic nuclear interactions, called the realistic Gamow shell model, was introduced later. The present review focuses on the recent applications of the GSM to drip line nuclei. [ABSTRACT FROM AUTHOR]

We study the problem of π production in heavy-ion collisions in the context of the isospin-dependent Boltzmann–Uehling–Uhlenbeck transport model. We generated nucleon densities using two different models, the Skyrme–Hartree–Fock (SHF) model and the configuration interaction shell model (SM). Indeed, inter-nucleon correlations are explicitly taken into account in SM, while they are averaged in the SHF model. As an application of our theoretical frameworks, we calculated the π − and π + yields in collisions of nuclei with A = 30–40 nucleons. We used different harmonic oscillator lengths b HO to generate the harmonic oscillator basis for SM in order to study both theoretical and experimental cases. It is found that the SM framework with b HO = 2.5 fm and SHF can be distinguished by the yield of π mesons, in this case the density distribution calculated by the SM produces more π in the collision. In comparison, SM with b HO = 2.0 fm is distinguished from SHF by the double π −/ π + ratios with different large impact parameters, from which one can find that the double π −/ π + ratios of SM change smoother and are less than those of SHF. [ABSTRACT FROM AUTHOR]

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