729 research outputs found

    A Meaning in Life Intervention: Setting Personal Goals and Reviewing Life Story Increases Positive Affect

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    Reporting a high level of meaning in one’s life has been found to impact an individual’s wellbeing and mental health in a positive way. However, the majority of meaning-orientated interventions have been developed to help individuals cope with adversity, while limited interventions have focused on promoting, flourishing, and preventing mental illnesses in the general population. This research aimed to develop and test an online meaning in life intervention aimed at the general population. Based on a theoretical framework of meaning in life and empirically validated approaches, a convenience sample of Icelandic adults (N = 177) participated in a Randomised Control Trial (RCT) and were assigned to one of two interventions or an active control group. The hypothesis stated that a Motivational Meaning Intervention and Cognitive Motivational Meaning Intervention would result in greater perceptions of self-reported Meaning in Life, Subjective Wellbeing, Psychological Wellbeing and Positive Affect compared to a control condition. The results showed that both interventions enhanced positive affect while neither intervention increased meaning in life, subjective wellbeing nor psychological wellbeing. The interventions appear to be inexpensive, easily administered, and effective in increasing positive affect which is a major contributor to an individual’s wellbeing. The study offers meaningful conclusions and future avenues to enhance intervention studies to develop essential elements of wellbeing and human functioning within general populations

    Coorbits for projective representations with an application to Bergman spaces

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    Recently representation theory has been used to provide atomic decompositions for a large collection of classical Banach spaces. In this paper we extend the techniques to also include projective representations. As our main application we obtain atomic decompositions of Bergman spaces on the unit ball through the holomorphic discrete series for the group of isometries of the ball

    Reflection positive affine actions and stochastic processes

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    In this note we continue our investigations of the representation theoretic aspects of reflection positivity, also called Osterwalder--Schrader positivity. We explain how this concept relates to affine isometric actions on real Hilbert spaces and how this is connected with Gaussian processes with stationary increments

    Reflection positivity for the circle group

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    In this note we characterize those unitary one-parameter groups (Utc)t∈R which admit euclidean realizations in the sense that they are obtained by the analytic continuation process corresponding to reflection positivity from a unitary representation U of the circle group. These are precisely the ones for which there exists an anti-unitary involution J commuting with Uc. This provides an interesting link with the modular data arising in Tomita-Takesaki theory. Introducing the concept of a positive definite function with values in the space of sesquilinear forms, we further establish a link between KMS states and reflection positivity on the circle

    Reflection negative kernels and fractional Brownian motion

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    In this article we study the connection of fractional Brownian motion, representation theory and reflection positivity in quantum physics. We introduce and study reflection positivity for affine isometric actions of a Lie group on a Hilbert space E and show in particular that fractional Brownian motion for Hurst index 0<H\le 1/2 is reflection positive and leads via reflection positivity to an infinite dimensional Hilbert space if 0<H <1/2. We also study projective invariance of fractional Brownian motion and relate this to the complementary series representations of GL(2,R). We relate this to a measure preserving action on a Gaussian L^2-Hilbert space L^2(E)

    Multiple melt plumes observed at the Breioamerkurjokull ice face in the upper waters of Jokulsarlon lagoon, Iceland

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    Breioamerkurjokull flows from the Vatnajokull ice cap and calves into the Jokulsarlon proglacial lagoon. The lagoon is connected to the North Atlantic Ocean through a 6 m deep narrow channel. Four hydrographic surveys in spring 2012, and a 2011 4-month long temperature and salinity time series of lagoon inflow show that the lake has significantly changed since 1976. Warm saline ocean water enters each tidal cycle and descends below the maximum sampled depths. The lagoon has a surface layer of ice melt, freshwater and Atlantic derived water. Beneath 10 m depth an advective/diffusive balance is responsible for determining the temperature and salinity of the lagoon waters down to ~90 m. To maintain the observed hydrographic structure, we calculate an upwelling of deep water of ~0.2 m d−1. A survey within 30 m of Breioamerkurjokull showed that the warmest and most saline waters sampled within the lagoon below 10 m depth were adjacent to the glacier face, along with multiple interleaved warm and cold layers. A heat and salt balance model shows that submarine melting along the ice face generates multiple meltwater plumes that are mixed and diluted within 200 m of the ice face

    Resting-state fMRI activity predicts unsupervised learning and memory in an immersive virtual reality environment

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    In the real world, learning often proceeds in an unsupervised manner without explicit instructions or feedback. In this study, we employed an experimental paradigm in which subjects explored an immersive virtual reality environment on each of two days. On day 1, subjects implicitly learned the location of 39 objects in an unsupervised fashion. On day 2, the locations of some of the objects were changed, and object location recall performance was assessed and found to vary across subjects. As prior work had shown that functional magnetic resonance imaging (fMRI) measures of resting-state brain activity can predict various measures of brain performance across individuals, we examined whether resting-state fMRI measures could be used to predict object location recall performance. We found a significant correlation between performance and the variability of the resting-state fMRI signal in the basal ganglia, hippocampus, amygdala, thalamus, insula, and regions in the frontal and temporal lobes, regions important for spatial exploration, learning, memory, and decision making. In addition, performance was significantly correlated with resting-state fMRI connectivity between the left caudate and the right fusiform gyrus, lateral occipital complex, and superior temporal gyrus. Given the basal ganglia's role in exploration, these findings suggest that tighter integration of the brain systems responsible for exploration and visuospatial processing may be critical for learning in a complex environment

    Airborne observations of the Eyjafjalla volcano ash cloud over Europe during air space closure in April and May 2010

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    © Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 LicenseAirborne lidar and in-situ measurements of aerosols and trace gases were performed in volcanic ash plumes over Europe between Southern Germany and Iceland with the Falcon aircraft during the eruption period of the Eyjafjalla1 volcano between 19 April and 18 May 2010. Flight planning and measurement analyses were supported by a refined Meteosat ash product and trajectory model analysis. The volcanic ash plume was observed with lidar directly over the volcano and up to a distance of 2700 km downwind, and up to 120 h plume ages. Aged ash layers were between a few 100 m to 3 km deep, occurred between 1 and 7 km altitude, and were typically 100 to 300 km wide. Particles collected by impactors had diameters up to 20 μm diameter, with size and age dependent composition. Ash mass concentrations were derived from optical particle spectrometers for a particle density of 2.6 g cm-3 and various values of the refractive index (RI, real part: 1.59; 3 values for the imaginary part: 0, 0.004 and 0.008). The mass concentrations, effective diameters and related optical properties were compared with ground-based lidar observations. Theoretical considerations of particle sedimentation constrain the particle diameters to those obtained for the lower RI values. The ash mass concentration results have an uncertainty of a factor of two. The maximum ash mass concentration encountered during the 17 flights with 34 ash plume penetrations was below 1 mg m-3. The Falcon flew in ash clouds up to about 0.8 mg m-3 for a few minutes and in an ash cloud with approximately 0.2 mg -3 mean-concentration for about one hour without engine damage. The ash plumes were rather dry and correlated with considerable CO and SO2 increases and O3 decreases. To first order, ash concentration and SO2 mixing ratio in the plumes decreased by a factor of two within less than a day. In fresh plumes, the SO2 and CO concentration increases were correlated with the ash mass concentration. The ash plumes were often visible slantwise as faint dark layers, even for concentrations below 0.1 mg m-3. The large abundance of volatile Aitken mode particles suggests previous nucleation of sulfuric acid droplets. The effective diameters range between 0.2 and 3 μm with considerable surface and volume contributions from the Aitken and coarse mode aerosol, respectively. The distal ash mass flux on 2 May was of the order of 500 (240-1600) kgs -1. The volcano induced about 10 (2.5-50) Tg of distal ash mass and about 3 (0.6-23) Tg of SO2 during the whole eruption period. The results of the Falcon flights were used to support the responsible agencies in their decisions concerning air traffic in the presence of volcanic ash.Peer reviewe

    Calibration of input parameters in volcanic areas and an enlarged dataset by stochastic finite-fault simulations

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    The calibration of input parameters is an important task for stochastic finite-fault simulation in volcanic areas, and we manage this in the framework of the European project UPStrat-MaFa. The stochastic simulation method requires the knowledge of fault geometry, source, crust properties of the region, and local site effects. At first, we focused the present study in the pilot test areas: Mt Vesuvius, Campi Flegrei and Mt Etna. Later, we performed two applications for a large magnitude event in the Azores Islands and the South Iceland regions. A general preliminary database of ground-motion records was collected in the test areas, to set up the empirical laws of the ground-motion parameters. The results of the simulations have been compared with observed waveforms and response spectra, to determine the suitability of the parameters used. The results show good agreement between the observed and simulated time histories and response spectra, thus encouraging further efforts towards quantitative high resolution studies on input parameters.Co-financed by the EU - Civil Protection Financial Instrument, in the framework the European project ”Urban disaster Prevention Strategies using MAcroseismic Fields and FAult Sources (Acronym: UPStrat-MAFA, Grant Agreement N. 23031/2011/613486/SUB/A5). http://ec.europa.eu/echo/funding/cp_projects2011_en.htmPublishedLisbon - Portugal4.1. Metodologie sismologiche per l'ingegneria sismicaope
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