The Effect of Leisure Activities on Life Satisfaction: The Importance of Holiday Trips

Does active leisure make life more satisfying? If so, what kind of leisure activity is the greatest contributor to happiness? These questions are answered by means of data from four waves of a large-scale continuous study of the general public in Germany. Cross-sectional analysis does not show much of a relationship between happiness and last year’s leisure activities, with the exception of holiday trips. People who took one or more holiday trips appeared to be significantly happier, even when income, health, and personality were controlled for. Over-time analysis suggests that the correlation is due to an effect of holiday trips on happiness rather than an effect of happiness on holiday tripping. If holiday trips boost happiness, the effect is short lived. This is not to say that the effect is trivial. Holiday trips accounted for about 2% of the variance in happiness, which is comparable to observed effects of some happiness training programs and financial windfalls

The effect of crack length and maximum stress on the fatigue crack growth rates of engineering alloys

The fatigue crack growth rate (FCGR) curve of metallic alloys is usually divided into three regions. Region II is often referred to as the Paris regime and is usually modelled with a power law relationship with a single exponent. Regions I and III are located at the beginning and end of the FCGR curve, respectively, and are frequently modelled with asymptotic relationships. In this paper we hypothesize that fatigue crack growth is governed by power law behaviour at all crack lengths and all stress intensity factor ranges (ΔK). To accommodate for the changes in the FCGR slope at regions I - III mathematical pivot points are introduced in the Paris equation. Power law behaviour with the presence of pivot points enables direct fitting of the crack length vs. cycles (a-N) curve to obtain the FCGR as a function of ΔK. This novel approach is applicable to small and long crack growth curves and results in accurate multilinear FCGR curves that are suitable for reconstruction of the measured a-N curves. The method is subsequently applied to i) different alloys to show local changes in the FCGR curve for changes in alloy composition and heat treatments, ii) naturally increasing ΔK testing of microstructurally small cracks to obtain accurate small crack FCGR data. The comparison with accurate long crack data shows that small cracks are faster, but the transition from region I to region II occurs at a specific fatigue crack growth rate which results in an apparent shift in ΔK at the transition. iii) Long cracks, which show that the FCGR increases with maximum stress for a given ΔK and stress ratio when the maximum stress approaches the yield stress. The maximum stress phenomenon becomes important in the case of fatigue testing, where the initial crack lengths are usually small and maximum stresses are high. It is concluded that for long cracks the phenomenon explains why the Paris equation is applicable rather at low maximum stress, while the Frost-Dugdale equation is more applicable at high maximum stress

Allergen immunotherapy for allergic airway diseases:Use lessons from the past to design a brighter future

Allergic respiratory diseases, such as allergic dermatitis, food allergy, allergic rhino conjunctivitis and allergic asthma, are chronic inflammatory diseases with increasing prevalence. Symptoms include such as watery or itchy itching of the mouth, skin, or the eyes, swelling of the face or throat, sneezing, congestion or vomiting, wheezing, shortness of breath and coughing. For allergic asthma, additional symptoms include tightness of chest, cough, wheezing, and reversible airflow limitation. These symptoms can be triggered by inhalation of aller -gens such as food allergens or airborne allergens such as those from tree-or grass pollen and house dust mites. Pharmacological intervention in allergic disease includes the use of antihistamines, immune suppressive drugs and in case of asthma, the use of (long acting) beta-agonists for relaxation of the constricted airways. These treat-ment options merely suppress symptoms and do not cure the disease. Allergen immunotherapy (AIT), in con -trast, has the capacity of inducing long-term tolerance, with symptom relief persisting decennia after discontinuation of treatment, despite recurrent re-exposure to the allergen. However, AIT is not effective for all allergic disorders, and treatment for several years is required to obtain long-term protection. Moreover, some forms of AIT have safety concerns, with risk of mild to severe allergic reactions. To improve safety and efficacy of AIT, the underlying mechanisms have been studied extensively in the clinic as well as in experimental models of allergic airway inflammation.Despite more than a century of clinical experience and a vast body of experimental and translational studies into the immunological and cellular mechanisms underpinning its therapeutic potential, AIT is still not implemented in routine clinical care for allergic asthma. This review provides an overview of the substantial developments that contribute to our knowledge of the pathogenesis of allergic airway diseases, the mechanism of action of AIT, its treatment routes and schedules, the standardization of extracts and use of adjuvantia. Moreover, the main con-clusions from experimental models of AIT with regard to the safety and effectiveness of the treatment are summarized, and future directions for further improvements are outlined. AIT urgently requires further improvements in order to increase its efficiency and shorten the treatment duration while remaining safe and costeffective.(c) 2022 Published by Elsevier Inc

Associations between depression, lifestyle and brain structure:A longitudinal MRI study

Background: Depression has been associated with decreased regional grey matter volume, which might partly be explained by an unhealthier lifestyle in depressed individuals which has been ignored by most earlier studies. Also, the longitudinal nature of depression, lifestyle and brain structure associations is largely unknown. This study investigates the relationship of depression and lifestyle with brain structure cross-sectionally and longitudinally over up to 9 years. Methods: We used longitudinal structural MRI data of persons with depression and/or anxiety disorders and controls (Nunique participants = 347, Nobservations = 609). Cortical thickness of medial orbitofrontal cortex (mOFC), rostral anterior cingulate cortex (rACC) and hippocampal volume were derived using FreeSurfer. Using Generalized Estimating Equations, we investigated associations of depression and lifestyle (Body mass index (BMI), smoking, alcohol consumption, physical activity and sleep duration) with brain structure and change in brain structure over 2 (n = 179) and 9 years (n = 82). Results: Depression status (B = -.053, p = .002) and severity (B = -.002, p = .002) were negatively associated with rACC thickness. mOFC thickness was negatively associated with BMI (B = -.004, p < .001) and positively with moderate alcohol consumption (B = .030, p = .009). All associations were independent of each other. No associations were observed between (change in) depression, disease burden or lifestyle factors with brain change over time. Conclusions: Depressive symptoms and diagnosis were independently associated with thinner rACC, BMI with thinner mOFC, and moderate alcohol consumption with thicker mOFC. No longitudinal associations were observed, suggesting that regional grey matter alterations are a long-term consequence or vulnerability indicator for depression but not dynamically or progressively related to depression course trajectory

High dose vitamin D3 empowers effects of subcutaneous immunotherapy in a grass pollen-driven mouse model of asthma

Allergen-specific immunotherapy (AIT) has the potential to provide long-term protection against allergic diseases. However, efficacy of AIT is suboptimal, while application of high doses allergen has safety concerns. The use of adjuvants, like 1,25(OH)2VitD3 (VitD3), can improve efficacy of AIT. We have previously shown that low dose VitD3 can enhance suppression of airway inflammation, but not airway hyperresponsiveness in a grass pollen (GP)-subcutaneous immunotherapy (SCIT) mouse model of allergic asthma. We here aim to determine the optimal dose and formulation of VitD3 for the GP SCIT. GP-sensitized BALBc/ByJ mice received three SCIT injections of VitD3-GP (30, 100, and 300 ng or placebo). Separately, synthetic lipids, SAINT, was added to the VitD3-GP-SCIT formulation (300 nmol) and control groups. Subsequently, mice were challenged with intranasal GP, and airway hyperresponsiveness, GP-specific IgE, -IgG1, and -IgG2a, ear-swelling responses (ESR), eosinophils in broncho-alveolar lavage fluid and lung were measured. VitD3 supplementation of GP-SCIT dose-dependently induced significantly enhanced suppression of spIgE, inflammation and hyperresponsiveness, while neutralizing capacity was improved and ESR were reduced. Addition of VitD3 further decreased Th2 cytokine responses and innate cytokines to allergens in lung tissue by GP-SCIT. However, addition of synthetic lipids to the allergen/VitD3 mixes had no additional effect on VitD3-GP-SCIT. We find a clear, dose dependent effect of VitD3 on GP-SCIT-mediated suppression of allergic inflammation and airway hyperresponsiveness. In contrast, addition of synthetic lipids to the allergen/VitD3 mix had no therapeutic effect. These studies underscore the relevance of VitD3 as an adjuvant to improve clinical efficacy of SCIT treatment regimens