Abstract
Cognitive aging is associated with widespread neural reorganization processes in the human brain. However, the behavioral impact of such reorganization is not well understood. The current ...neuroimaging study investigated age differences in the functional network architecture during semantic word retrieval in young and older adults. Combining task-based functional connectivity, graph theory and cognitive measures of fluid and crystallized intelligence, our findings show age-accompanied large-scale network reorganization even when older adults have intact word retrieval abilities. In particular, functional networks of older adults were characterized by reduced decoupling between systems, reduced segregation and efficiency, and a larger number of hub regions relative to young adults. Exploring the predictive utility of these age-related changes in network topology revealed high, albeit less efficient, performance for older adults whose brain graphs showed stronger dedifferentiation and reduced distinctiveness. Our results extend theoretical accounts on neurocognitive aging by revealing the compensational potential of the commonly reported pattern of network dedifferentiation when older adults can rely on their prior knowledge for successful task processing. However, we also demonstrate the limitations of such compensatory reorganization and show that a youth-like network architecture in terms of balanced integration and segregation is associated with more economical processing.
Background: Due to the numerous barriers people with a physical disability face to being physically active, emphasis in practice and research is often placed on creating opportunities for ...participation. As such, the quality of the experience is often ignored once an individual is participating.
Purpose: An understanding of how to create quality physical activity experiences is critical to foster enjoyable and sustained participation. The aim of this systematic review was to identify intervention and/or program conditions that may foster key elements that shape quality participation (QP) experiences.
Methods: In all, 24 qualitative and 6 quantitative studies met inclusion criteria. The results of the qualitative studies were synthesized using thematic analysis.
Results: The synthesis identified two program conditions as important for fostering QP elements: (1) group-based programing: participating with peers can be linked to belongingness and mastery and (2) leadership: knowledgeable instructors may foster mastery and autonomy. The quantitative studies lacked variability in program conditions and QP elements, which precluded associating specific conditions with elements of a quality experience.
Conclusions: Although the qualitative findings highlight two program conditions which may foster QP elements, overall, evaluations of physical activity interventions involving people with disabilities rarely include experiential aspects of participation.
Implications for rehabilitation
Group-based programming and leadership are two program conditions that may foster elements of quality participation.
Physical activity organizers need to consider group composition. Physical activity programs should consist of peers with a disability, as appropriate, in order to promote belongingness.
Physical activity programs should provide disability-specific training to leaders or seek leaders with disability-specific knowledge, in addition to physical activity knowledge and skills.
Sarcoidosis is a multi-system inflammatory disease characterized by the development of inflammation and noncaseating granulomas that can involve nearly every organ system, with a predilection for the ...pulmonary system. Cardiac involvement of sarcoidosis (CS) occurs in up to 70% of cases, and accounts for a significant share of sarcoid-related mortality. The clinical presentation of CS can range from absence of symptoms to conduction abnormalities, heart failure, arrhythmias, valvular disease, and sudden cardiac death. Given the significant morbidity and mortality associated with CS, timely diagnosis is important. Traditional imaging modalities and histologic evaluation by endomyocardial biopsy often provide a low diagnostic yield. Cardiac positron emission tomography (PET) has emerged as a leading advanced imaging modality for the diagnosis and management of CS. This review article will summarize several aspects of the current use of PET in CS, including indications for use, patient preparation, image acquisition and interpretation, diagnostic and prognostic performance, and evaluation of treatment response. Additionally, this review will discuss novel PET radiotracers currently under study or of potential interest in CS.
To examine the criterion validity and test-retest reliability of the Leisure Time Physical Activity Questionnaire for People with Spinal Cord Injury (LTPAQ-SCI), a brief measure of leisure time ...physical activity (LTPA) for people with spinal cord injury (SCI).
Survey with a 1-week follow-up.
General community.
Men and women with SCI (N=103; mean age ± SD, 48.1±12.7 y; mean years postinjury ± SD, 17.9±11.9) who used a wheelchair as the primary mode of mobility.
Not applicable.
Participants completed the Physical Activity Recall Assessment for People with SCI (PARA-SCI) and the LTPAQ-SCI. A subset of the participants (n=35) completed the LTPAQ-SCI a second time, 7 days later.
Statistically significant, positive correlations emerged between the LTPAQ-SCI and PARA-SCI measures of mild, moderate, and heavy intensity LTPA as well as total LTPA. All 4 intraclass correlation coefficients were significant across the test-retest period.
This study provides preliminary evidence of the criterion validity and reliability of the LTPAQ-SCI as a brief measure of LTPA performed by people with SCI.
Human aging is associated with an increased frequency of somatic mutations in hematopoietic cells. Several of these recurrent mutations, including those in the gene encoding the epigenetic modifier ...enzyme TET2, promote expansion of the mutant blood cells. This clonal hematopoiesis correlates with an increased risk of atherosclerotic cardiovascular disease. We studied the effects of the expansion of Tet2-mutant cells in atherosclerosis-prone, low-density lipoprotein receptor–deficient (Ldlr
–/–) mice. We found that partial bone marrow reconstitution with TET2-deficient cells was sufficient for their clonal expansion and led to a marked increase in atherosclerotic plaque size. TET2-deficient macrophages exhibited an increase in NLRP3 inflammasome–mediated interleukin-1β secretion. An NLRP3 inhibitor showed greater atheroprotective activity in chimeric mice reconstituted with TET2-deficient cells than in nonchimeric mice. These results support the hypothesis that somatic TET2 mutations in blood cells play a causal role in atherosclerosis.
Leadership Styles, Emotion Regulation, and Burnout Arnold, Kara A; Connelly, Catherine E; Walsh, Megan M ...
Journal of occupational health psychology,
10/2015, Letnik:
20, Številka:
4
Journal Article
Recenzirano
This study investigated the potential impact of leadership style on leaders' emotional regulation strategies and burnout. Drawing on the full-range model of leadership and Conservation of Resources ...(COR) theory, we tested whether transformational, contingent reward, management by exception-active and -passive, or laissez-faire leadership exert direct effects on leaders' reported use of surface acting, deep acting, and genuine emotion. In turn, we hypothesized and tested the indirect effect of leadership on burnout through surface acting. Three waves of data from 205 leaders were analyzed using OLS regression. Transformational leadership predicted deep acting and genuine emotion. Contingent reward predicted both surface and deep acting. Management by exception-active and -passive predicted surface acting, and laissez faire predicted genuine emotion. The indirect effects of management by exception-active and -passive on burnout through surface acting were not significant. Indirect effects of transformational leadership and laissez-faire on burnout through genuine emotion, however, were significant. This study provides empirical evidence for the hypothesized relationships between leadership style, emotion regulation, and burnout, and provides the basis for future research and theory building on this topic.
Among samples of people with physical disabilities, the effects of physical activity (PA) interventions and the factors that influence intervention success are unknown. The purpose of this ...meta-analysis was to i) evaluate the overall effect of interventions on PA behaviour and ii) examine the influence of intervention characteristics, theory, and behaviour change techniques (BCTs) on PA intervention effects in persons with physical disability.
Meta-analysis.
Medline, Embase, PsychINFO, and AMED databases were searched for randomized controlled trials that evaluated the effects of a PA intervention in people with physical disability. Data were extracted regarding study and intervention characteristics and use of theory. Intervention descriptions were coded using the BCT Taxonomy version 1.
A total of 24 articles met the inclusion criteria. Overall, interventions had a small to medium-sized effect on PA behaviour (g = 0.35, k = 22, 95% CI 0.21, 0.48). Interventions that used theory (g = 0.53, k = 12, 95% CI 0.38, 0.68) had larger effects than interventions that did not, p < 0.001. Interventions that included self-monitoring of behaviour produced larger effects (g = 0.45 k = 12, 95% CI 0.28, 0.63, p = .04) and interventions with monitoring of behaviour by others without feedback produced smaller effects (g = 0.05, k = 3, 95% CI -0.22, 0.32, p = .02) than studies without these BCTs.
Interventions to increase PA behaviour in people with physical disability are effective, especially when theory is used to guide their development. Research is needed to examine a wider range of BCTs and the moderating effects of intervention characteristics on PA behaviour.
•Overall, physical activity interventions showed small to medium-sized effects on physical activity behaviour (g = .35).•Larger effects were yielded when intervention development was guided by behaviour change theory.•Interventions incorporating self-monitoring had larger effects on physical activity behaviour than those that did not.•Interventions using monitoring of behaviour by others without feedback had smaller effects on physical activity behaviour.
The purpose of this study was to determine objective and subjective quantification of habitual physical activity (HPA) and sedentary time in ambulatory and nonambulatory adults with cerebral palsy ...(CP).
We recruited a clinical sample of adults with CP (N = 42; 21 women; mean (SD) age, 33.5 (12.3) yr; Gross Motor Function Classification System (GMFCS) distribution: level I (n = 5), level II (n = 9), level III (n = 10), level IV (n = 11), and level V (n = 7). Objective measures of HPA and sedentary time were obtained by using ActiGraph GT3X accelerometers at both hip and wrist sites. Three previously established cut-point values distinguishing light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) were evaluated across GMFCS levels. The concurrent validity of the self-report Physical Activity Recall Assessment for People with Spinal Cord Injury (PARA-SCI) was assessed for LPA and MVPA intensities in GMFCS levels II-V.
Participants showed little reluctance to wearing accelerometers; one participant reported discomfort. Nonambulatory adults (GMFCS levels IV-V) differed from ambulatory adults (GMFCS levels I-III) for recorded activity counts (hip and wrist sites), minutes of MVPA with each cut-point value, and breaks from sedentary time (all P < 0.05). For the same measures, adults in GMFCS level III also differed from GMFCS level I (all P < 0.05). The PARA-SCI correlated significantly with accelerometer-derived minutes of MVPA per day (r = 0.396; P = 0.014) and per hour of monitoring time (r = 0.356; P = 0.027).
Our findings support the use of accelerometers to objectively measure HPA and sedentary behavior in adults with CP across the severity spectrum, regardless of cut-point implementation. The PARA-SCI is a valid tool to capture subjectively reported patterns of MVPA in adults with CP who are GMFCS levels II-V.
Unfolded protein response (UPR) is a multifaceted signaling cascade that alleviates protein misfolding. Although well studied in nucleated cells, UPR in absence of transcriptional regulation has not ...been described. Intricately associated with cardiovascular diseases, platelets, despite being anucleate, respond rapidly to stressors in blood. We investigate the UPR in anucleate platelets and explore its role, if any, on platelet physiology and function.
Human and mouse platelets were studied using a combination of ex vivo and in vivo experiments. Platelet lineage-specific knockout mice were generated independently for each of the 3 UPR pathways, PERK (protein kinase RNA PKR-like endoplasmic reticulum kinase), XBP1 (X-binding protein), and ATF6 (activating transcription factor 6). Diabetes patients were prospectively recruited, and platelets were evaluated for activation of UPR under chronic pathophysiological disease conditions.
Tunicamycin induced the IRE1α (inositol-requiring enzyme-1alpha)-XBP1 pathway in human and mouse platelets, while oxidative stress predominantly activated the PERK pathway. PERK deletion significantly increased platelet aggregation and apoptosis and phosphorylation of PLCγ2, PLCβ3, and p38 MAPK. Deficiency of XBP1 increased platelet aggregation, with higher PLCβ3 and PKCδ activation. ATF6 deletion mediated a relatively modest effect on platelet phenotype with increased PKA (protein kinase A). Platelets from diabetes patients exhibited a positive correlation between disease severity, platelet activation, and protein aggregation, with only IRE1α-XBP1 activation. Moreover, IRE1α inhibition increased platelet aggregation, while clinically approved chemical chaperone, sodium 4-phenylbutyrate reduced the platelet hyperactivation.
We show for the first time, that UPR activation occurs in platelets and can be independent of genomic regulation, with selective induction being specific to the source and severity of stress. Each UPR pathway plays a key role and can differentially modulate the platelet activation pathways and phenotype. Targeting the specific arms of UPR may provide a new antiplatelet strategy to mitigate thrombotic risk in diabetes and other cardiovascular diseases.
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