1,541 research outputs found

    Polarization Ray Tracing and Polarization Aberration Compensation in Reflective Astronomical Telescopes

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    Assessing and optimizing polarization performance in the context of ray-based optical design can be challenging. We describe an approach to this problem that decouples polarization effects from optical system geometry for reflective systems. Each surface's polarization properties are parameterized in terms of their impact on retardance and diattenuation in the small angle-of-incidence limit, separating polarization assessment from the task of coating design. A low-resolution ray trace of the system is adequate to determine ray geometry at each interface, which can then be interpolated to rapidly evaluate net Jones Matrix pupil functions. Coating behavior can be easily varied using the ellipsometric parameters to investigate impacts and compensation. Desired values of these parameters can then be specified as constraints in coating design. Investigation with candidate telescope optical designs for LUVOIR show baseline root-mean-square wavefront errors in the nm range for the on-diagonal Jones matrix component, and throughputs of tens of parts per million. Promising possibilities for compensation using a purpose-designed coating on the secondary mirror are discussed, which reduce the on-diagonal wavefront error by a factor 20, with accompanying but more modest reductions in coupling into off-diagonal terms

    A grounded theory of inspirational coach leadership

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    The purpose of this study was to develop a grounded theory of the process of inspirational coach leadership in sport. A Straussian grounded theory methodology was used. Semi‐structured interviews and focus groups were conducted with athletes (n = 22) and coaches (n = 15). Data were analyzed through a process of open and axial coding, and theoretical integration. Through the process of analysis, data were broken down into smaller units (concepts), relationships between concepts were identified, and a substantive grounded theory was developed. The grounded theory of inspirational coach leadership was built around the core category of “athlete(s) inspired through changed awareness of their capabilities.” The core category was underpinned by three categories: (a) establishment of mutual trust and respect with athletes, whereby coaches need to establish trust with athletes in order to inspire athletes; (b) conditions under which inspiration has the potential to occur, which highlighted that athletes are inspired in situations where they are vulnerable or ignorant regarding their potential; and (c) coach acts to change athlete's awareness of their capabilities, which denotes the specific behaviors coaches should display to inspire athletes in such conditions. The theory also highlights that a range of contextual factors relating to the coach, athletes, and performance‐environment interact to impact upon the process. The theory predicts that consistency between coach behavior and the conditions in which inspiration can occur will lead to athlete inspiration, but only if the coach has established a foundation of trust and respect with the athlete

    Time-Clamped, RPE-Matched Treadmill Activity and Interactive Video Game Dancing Differ in Step Count But Not Heart Rate Response

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    Background: Participation in regular moderate or vigorous physical activity (MVPA) results in numerous health benefits. Task enjoyment is a known antecedent and promoter of regular activity engagement. Participation in interactive video gaming has increased in recent years. Purpose: The aims of the present investigation were to: 1) determine heart rate (HR) and step count outcomes of time-clamped and RPE-matched interactive video game dancing (VGD) and treadmill activity; 2) characterize the suitability of VGD to achieve MVPA designation; and, 3) investigate step count outcomes recorded by pedometry and accelerometry. Methods: Subjects underwent three testing sessions with the latter two randomized. During the familiarization visit, the perceived exertion (Borg RPE) of an interactive VGD activity was determined and a treadmill speed that resulted in an RPE-matched exertion level was identified through incremental increases in treadmill speed. On subsequent visits, subjects completed 15 minutes of VGD or RPE-matched treadmill activity. HR and step count were measured during both sessions. Results: Nine participants (Age 19.8 ± 1.6; 5 males; 4 females) volunteered. With time-clamped and RPE-matched, the average HR for dancing 154.7 (± 21.8) and treadmill activity 157.8 (± 25.1) were not different (p = 0.698). The selected dances for the VGD activity resulted in 8/9 subjects exercising at MVPA intensity according to percent of predicted maximal HR (threshold of 64% maximal HR; equation: 207 – 0.7*Age). Steps completed during dancing and treadmill activity according to pedometry were 1510 (± 488) and 2066 (± 247), respectively, with the difference being significant (p = 0.001). Steps completed during dancing and the treadmill activity according to accelerometry were 988 (± 256) and 1938 (± 119), respectively, with the difference again significant (p \u3c 0.001). The within-mode, between-device step count (pedometer vs. accelerometer, respectively) were also of interest. For dancing, a significant difference (p \u3c 0.001) was noted as 1510 (± 488) vs. 988 (± 256) steps. For treadmill activity, the disparity between 2066 (± 247) vs. 1938 (± 119) was also different (p = 0.042). Discussion: The HR response of a VGD activity was not different than a time-clamped, RPE-matched treadmill activity. Furthermore, VGD achieved designation as MVPA intensity in 8/9 subjects with the lone subject failing to achieve moderate designation by a single beat. Of note, objectively determined step count varied by mode and measuring device illustrating the need to employee prudency when selecting measuring technique for step count during rhythmic vs. non-rhythmic PA

    Executive Function and Spatial Cognition Mediate Psychosocial Dysfunction in Major Depressive Disorder

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    Background: Cognitive and psychosocial dysfunction are prevalent and disabling features of Major Depressive Disorder (MDD). Emerging evidence suggests that poor cognitive functioning mediates the negative effect of MDD on psychosocial function. However, there is a lack of research examining the domain-specific nature of this relationship. The current study evaluated whether the relationship between MDD and specific psychosocial subdomains (e.g., autonomy, occupational functioning) was mediated by domain-specific cognitive deficits.Methods: Data from 155 participants was obtained from the Cognitive Function and Mood Study (CoFaMS), a cross-sectional analysis of mood, cognition, social cognition, and functioning in individuals with MDD. Cognitive functioning was assessed (Current MDD n = 45, Healthy n = 110), with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the Colorado Assessment Tests (CATs), and the Psychology Experiment Building Language (PEBL). Psychosocial functioning was clinically evaluated with the Functioning Assessment Short Test (FAST).Results: The results indicated that spatial cognition and executive functioning partially mediated the negative effect of MDD on overall psychosocial functioning, autonomy, and subjective cognition. In contrast, spatial and executive domains showed divergent mediation patterns on interpersonal relationships and leisure time.Conclusions: The findings suggest that executive and spatial cognition play an important role in the pathology of overall psychosocial functioning, and specific functional issues in MDD. Treatments targeting psychosocial recovery in MDD may be improved by emphasizing executive and spatial cognitive remediation

    Executive Subdomains Are Differentially Associated With Psychosocial Outcomes in Major Depressive Disorder

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    Background: Deficits in executive functioning are frequently associated with poor psychosocial outcomes in Major Depressive Disorder (MDD). However, there is a poor understanding of the domain-specific relationships between executive subdomains (e.g., forward planning, decision making) and specific psychosocial issues (e.g., occupational functioning, social relationships). The current study explored these relationships across currently depressed and remitted MDD patients, as well as a healthy control group.Methods: Data from 142 participants were obtained from the Cognitive Functioning and Mood Study (CoFaM-S), a cross sectional study of mood, cognition, and psychosocial functioning in mood disorders. Participants' [current depression n = 31, remitted depression n = 52, healthy controls (HC) n = 59] executive functioning was evaluated with well-established tests of executive subdomains (i.e., Tower of London, card sorting, Stroop task). The Functioning Assessment Short Test (FAST) was employed to clinically evaluate psychosocial dysfunction.Results: The results indicated that forward planning was most strongly associated with psychosocial issues in the current depression group as compared to HCs, while cognitive updating was primary in the remitted group vs. HC.Conclusions: These findings suggest that executive subdomains are deferentially associated with psychosocial issues across different stages of depressive illness, and that forward planning and cognitive updating should be considered in adjunctive cognitive treatment

    The Direct and Indirect Relationship Between Social Cognition and Psychosocial Dysfunction in Major Depressive Disorder

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    Background: Recent evidence suggests that depressed patients experience social cognitive deficits (e.g., poor affect recognition). However, very little is known regarding the contribution of social cognitive deficits to psychosocial dysfunction (e.g., occupational functioning). In particular, the mechanistic roles of depression severity and cognitive deficits (e.g., memory) in this domain have not been explored. The current study evaluated the extent to which mood symptoms and cognitive deficits provide a mechanistic explanation for the relationship between social cognitive and psychosocial deficits in major depressive disorder (MDD).Methods: Data were obtained from 111 participants with MDD (75 Female, mean age = 35, 84% Caucasian, 12% Asian, 4% Other) in the Cognitive Function and Mood Study (CoFaM-S), a cross-sectional study of mood, social cognition, cognition, and psychosocial functioning in mood disorders. Social cognitive abilities were assessed using the Social Perception subtest of the Wechsler Adult Intelligence Scale, and psychosocial dysfunction was clinically evaluated with the Functioning Assessment Short Test (FAST).Results: Cognitive deficits and mood symptoms did not significantly mediate relationships between social cognitive ability and psychosocial dysfunction. The exception was executive function, which mediated an indirect relationship between meaning interpretation (i.e., theory of mind) and self-perceived cognitive dysfunction.Conclusion: The results suggest that the relationship between social cognitive deficits and psychosocial dysfunction is not mechanistically explained by mood symptoms or nonsocial cognition. Development of treatment strategies targeting social cognitive deficits in patients with MDD is warranted

    Sterically restricted tin phosphines, stabilized by weak intramolecular donor-acceptor interactions

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    Funding: Engineering and Physical Sciences Research Council (EPSRC)Four related sterically restricted pen-substituted acenaphthenes have been prepared containing mixed tin phosphorus moieties in the proximal 5,6-positions (Acenap[SnR3][(PPr2)-Pr-i]; Acenap = acenaphthene-5,6-diyl; R-3 = Ph-3 (1), Ph2Cl (2), Me2Cl (3), Bu2Cl (4)). The degree of intramolecular P-Sn bonding within the series was investigated by X-ray crystallography, solution and solid-state NMR spectroscopy, and density functional theory (DFT/B3LYP/SBKJC/PCM) calculations. All members of the series adopt a conformation such that the phosphorus lone pair is located directly opposite the tin center, promoting an intramolecular donor acceptor P -> Sn type interaction. The extent of covalent bonding between Sn and P is found to be much greater in triorganotin chlorides 2-4 in comparison with the triphenyl derivative 1. Coordination of a highly electronegative chlorine atom naturally increases the Lewis acidity of the tin center, enhancing the Ip(P)-sigma*(Sn-Y) donor acceptor 3c-4e type interaction, as indicated by conspicuously short Sn-P peri distances and significant (1)J(P-31,Sn-119) spin spin coupling constants (SSCCs) in the range 740-754 Hz. Evidence supporting the presence of this interaction was also found in solid-state NMR spectra of some of the compounds which exhibit an indirect spin spin coupling on the same order of magnitude as observed in solution. DFT calculations confirm the increased covalent bonding between P and Sn in 2-4, with notable WBIs of ca. 0.35 obtained, in comparison to 0.1 in 1.PostprintPeer reviewe

    Digital outpatient health solutions as a vehicle to improve healthcare sustainability—a United Kingdom focused policy and practice perspective

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    IntroductionIn the midst of a global climate emergency and with health care systems across the world facing extreme pressure, interest in digital approaches as a potential part-solution to these challenges has increased rapidly. The evidence base to support the role that digitalization can play in moving towards more sustainable models of healthcare is growing, as is the awareness of this key area of healthcare reform amongst policy makers, clinicians and the public.Method and ResultsIn this policy and practice review we explore four domains of healthcare sustainability-environmental, economic, and patient and clinician, delineating the potential impact that digitally enabled healthcare can have on each area. Real-world examples are provided to illustrate the impact individual digital interventions can have on each pillar of sustainability and demonstrate the scale of the potential benefits which can be achieved.DiscussionDigitally enabled healthcare solutions present an approach which offer numerous benefits, including environmental sustainability, economic benefits, and improved patient experience. There are also potential drawbacks such as the risk of digital exclusion and the need for integration with existing technology platforms. Overall, it is essential to strike a balance between the benefits and potential drawbacks of digital healthcare solutions to ensure that they are equitable, effective, and sustainable
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