Research on meditation is advancing, but few studies about the motivations of meditators exist. Additionally, many forms and traditions of meditation have yet to be investigated. This study addresses ...both of these issues by presenting an overview of different forms of motivations found in contemporary Anthroposophic meditation practice. 30 Anthroposophic meditators were interviewed about their meditation experiences. The interviews were examined using thematic analysis. 14 data-driven themes were extracted and organized within a framework consisting of three superordinate theory-driven forms of motivation: External, internal and service. A developmental trajectory running from external and internal to service motivations is indicated. This approach improves upon a scheme developed by Shapiro by including additional types of motivations and being able to differentiate between forms of motivations that are fundamentally different: Self-related (heteronomous and autonomous) motivations and other-related motivations.
Cultivation of mindfulness, the nonjudgmental awareness of experiences in the present moment, produces beneficial effects on well-being and ameliorates psychiatric and stress-related symptoms. ...Mindfulness meditation has therefore increasingly been incorporated into psychotherapeutic interventions. Although the number of publications in the field has sharply increased over the last two decades, there is a paucity of theoretical reviews that integrate the existing literature into a comprehensive theoretical framework. In this article, we explore several components through which mindfulness meditation exerts its effects: (a) attention regulation, (b) body awareness, (c) emotion regulation (including reappraisal and exposure, extinction, and reconsolidation), and (d) change in perspective on the self. Recent empirical research, including practitioners' self-reports and experimental data, provides evidence supporting these mechanisms. Functional and structural neuroimaging studies have begun to explore the neuroscientific processes underlying these components. Evidence suggests that mindfulness practice is associated with neuroplastic changes in the anterior cingulate cortex, ínsula, temporo-parietal junction, fronto-limbic network, and default mode network structures. The authors suggest that the mechanisms described here work synergistically, establishing a process of enhanced self-regulation. Differentiating between these components seems useful to guide future basic research and to specifically target areas of development in the treatment of psychological disorders.
This study investigated differences in brain activation during meditation between meditators and non-meditators. Fifteen Vipassana meditators (mean practice: 7.9 years, 2
h daily) and fifteen ...non-meditators, matched for sex, age, education, and handedness, participated in a block-design fMRI study that included mindfulness of breathing and mental arithmetic conditions. For the meditation condition (contrasted to arithmetic), meditators showed stronger activations in the rostral anterior cingulate cortex and the dorsal medial prefrontal cortex bilaterally, compared to controls. Greater rostral anterior cingulate cortex activation in meditators may reflect stronger processing of distracting events. The increased activation in the medial prefrontal cortex may reflect that meditators are stronger engaged in emotional processing.
Earth’s mantle contains Ne resembling the solar wind implanted Ne-B component in meteorites (20Ne/22NeNe-B: ∼12.7). The atmosphere, instead, displays a “planetary” signature (20Ne/22NeAtm: 9.80). We ...explore the parameter space of a model that explains these isotopic variations by the contribution of late accreting volatile-rich material (e.g., carbonaceous chondrite-like) to Earth́s atmosphere, while Earth́s mantle incorporated solar wind type Ne that was previously implanted into part of the accreting material.
Analyses of the present-day terrestrial influx mass distributions show two major peaks at large bodies >1 km and small ∼200 µm dust particles. The latter dominate the influx of the surface implanted Ne-B component. Ne measurements of small particles define a maximum surface flux (neon reaching the terrestrial surface) peaking at 9 µm, while larger micrometeorites experience ablation losses and isotopic fractionation upon atmospheric entry. Using these data, we reconstruct the unfractionated Ne-B upper atmosphere flux which peaks at ∼75 µm. As the extraterrestrial influx mass distribution between larger bodies and debris dust is governed by equilibrium due to collisions and fragmentation, it is an approximation of the early solar system (after nebula dissipation), where the mass distribution was similar but total fluxes were higher.
Contributions of Ne-B by small dust and planetary Ne-A from larger bodies strongly depend on formation region. Originating around the 1 AU region, early accretionary fluxes were dominated by Ne-B as large bodies likely contained only negligible amounts of Ne-A. Ne-B will be ultimately delivered to the earliest protoatmosphere by impact or thermal degassing and a significant fraction of Ne-B can enter the Earth́s interior via dissolution into a magma ocean before the Moon-forming impact. After the Moon-forming impact, Ne-B reenters the atmosphere by mantle degassing and a later meteoritic contribution modified the atmospheric composition. This meteoritic component was likely dominated by Ne-A, as the only remaining planetesimals at that time were in the asteroid belt or beyond, leading to preferential contributions of carbonaceous chondrite-type material.
In our model we take into account possible variations of several parameters, e.g. the isotopic composition of the late accretion (i.e., 20Ne/22Ne: 5.2–9.2). For example, a 20Ne/22Ne ratio of 8.2 (Ne-A composition) would imply ∼2% mass increase of Earth from CC-type material after the Moon-forming impact, and would require that todaýs atmosphere (20Ne/22Ne = 9.8) formed by roughly equal mixing of late accreted Ne-A and mantle Ne-B. The amount of Ne-B added from the mantle implies a certain degree of mantle degassing (in this case 82–96%, depending on todaýs mantle neon inventory) and constrains two further parameters: the fraction of solar wind irradiated material delivered to Earth before the Moon-forming impact and the magma ocean depth. The latter determines the fraction of Ne-B dissolved from a protoatmosphere. For example, magma ocean depths between 500 and 2900 km allow 4–15% dissolution of the protoatmospheric Ne-B inventory, and would require only less than 10% of irradiated accreting material. Only unreasonable magma ocean depths lower than 200 km require several ten percent of irradiated material.
Noble gases are not rare in the Universe, but they are rare in rocks. As a consequence, it has been possible to identify in detailed analyses a variety of components whose existence is barely visible ...in other elements: radiogenic and cosmogenic gases produced in situ, as well as a variety of “trapped” components – both of solar (solar wind) origin and the “planetary” noble gases. The latter are most abundant in the most primitive chondritic meteorites and are distinct in elemental and isotopic abundance patterns from planetary noble gases sensu strictu, e.g., those in the atmospheres of Earth and Mars, having in common only the strong relative depletion of light relative to heavy elements when compared to the solar abundance pattern. In themselves, the “planetary” noble gases in meteorites constitute again a complex mixture of components including such hosted by pre-solar stardust grains.
The pre-solar components bear witness of the processes of nucleosynthesis in stars. In particular, krypton and xenon isotopes in pre-solar silicon carbide and graphite grains keep a record of physical conditions of the slow-neutron capture process (s-process) in asymptotic giant branch (AGB) stars. The more abundant Kr and Xe in the nanodiamonds, on the other hand, show a more enigmatic pattern, which, however, may be related to variants of the other two processes of heavy element nucleosynthesis, the rapid neutron capture process (r-process) and the p-process producing the proton-rich isotopes.
“Q-type” noble gases of probably “local” origin dominate the inventory of the heavy noble gases (Ar, Kr, Xe). They are hosted by “phase Q”, a still ill-characterized carbonaceous phase that is concentrated in the acid-insoluble residue left after digestion of the main meteorite minerals in HF and HCl acids. While negligible in planetary-gas-rich primitive meteorites, the fraction carried by “solubles” becomes more important in chondrites of higher petrologic type. While apparently isotopically similar to Q gas, the elemental abundances are somewhat less fractionated relative to the solar pattern, and they deserve further study. Similar “planetary” gases occur in high abundance in the ureilite achondrites, while small amounts of Q-type noble gases may be present in some other achondrites. A “subsolar” component, possibly a mixture of Q and solar noble gases, is found in enstatite chondrites. While no definite mechanism has been identified for the introduction of the planetary noble gases into their meteoritic host phases, there are strong indications that ion implantation has played a major role.
The planetary noble gases are concentrated in the meteorite matrix. Ca-Al-rich inclusions (CAIs) are largely planetary-gas-free, however, some trapped gases have been found in chondrules. Micrometeorites (MMs) and interplanetary dust particles (IDPs) often contain abundant solar wind He and Ne, but they are challenging objects for the analysis of the heavier noble gases that are characteristic for the planetary component. The few existing data for Xe point to a Q-like isotopic composition. Isotopically Q-Kr and Q-Xe show a mass dependent fractionation relative to solar wind, with small radiogenic/nuclear additions. They may be closer to “bulk solar” Kr and Xe than Kr and Xe in the solar wind, but for a firm conclusion it is necessary to gain a better understanding of mass fractionation during solar wind acceleration.
: We aimed to identify electroencephalographic (EEG) signal fluctuations within independent components (ICs) that correlate to spontaneous blood oxygenation level dependent (BOLD) activity in regions ...of the default mode network (DMN) during eyes-closed resting state.
: We analyzed simultaneously acquired EEG and functional magnetic resonance imaging (fMRI) eyes-closed resting state data in a convenience sample of 30 participants. IC analysis (ICA) was used to decompose the EEG time-series and common ICs were identified using data-driven IC clustering across subjects. The IC time courses were filtered into seven frequency bands, convolved with a hemeodynamic response function (HRF) and used to model spontaneous fMRI signal fluctuations across the brain. In parallel, group ICA analysis was used to decompose the fMRI signal into ICs from which the DMN was identified. Frequency and IC cluster associated hemeodynamic correlation maps obtained from the regression analysis were spatially correlated with the DMN. To investigate the reliability of our findings, the analyses were repeated with data collected from the same subjects 1 year later.
: Our results indicate a relationship between power fluctuations in the delta, theta, beta and gamma frequency range and the DMN in different EEG ICs in our sample as shown by small to moderate spatial correlations at the first measurement (0.234 <
< 0.346,
< 0.0001). Furthermore, activity within an EEG component commonly identified as eye movements correlates with BOLD activity within regions of the DMN. In addition, we demonstrate that correlations between EEG ICs and the BOLD signal during rest are in part stable across time.
: We show that ICA source separated EEG signals can be used to investigate electrophysiological correlates of the DMN. The relationship between the eye movement component and the DMN points to a behavioral association between DMN activity and the level of eye movement or the presence of neuronal activity in this component. Previous findings of an association between frontal midline theta activity and the DMN were replicated.
Almost a decade after methane was first reported in the atmosphere of Mars there is an intensive discussion about both the reliability of the observations--particularly the suggested seasonal and ...latitudinal variations--and the sources of methane on Mars. Given that the lifetime of methane in the Martian atmosphere is limited, a process on or below the planet's surface would need to be continuously producing methane. A biological source would provide support for the potential existence of life on Mars, whereas a chemical origin would imply that there are unexpected geological processes. Methane release from carbonaceous meteorites associated with ablation during atmospheric entry is considered negligible. Here we show that methane is produced in much larger quantities from the Murchison meteorite (a type CM2 carbonaceous chondrite) when exposed to ultraviolet radiation under conditions similar to those expected at the Martian surface. Meteorites containing several per cent of intact organic matter reach the Martian surface at high rates, and our experiments suggest that a significant fraction of the organic matter accessible to ultraviolet radiation is converted to methane. Ultraviolet-radiation-induced methane formation from meteorites could explain a substantial fraction of the most recently estimated atmospheric methane mixing ratios. Stable hydrogen isotope analysis unambiguously confirms that the methane released from Murchison is of extraterrestrial origin. The stable carbon isotope composition, in contrast, is similar to that of terrestrial microbial origin; hence, measurements of this signature in future Mars missions may not enable an unambiguous identification of biogenic methane.
The present research addresses the induction of emotion during music listening in
adults using categorical and dimensional theories of emotion as background. It
further explores the influences of ...musical preference and absorption trait on
induced emotion. Twenty-five excerpts of classical music representing `happiness',
`sadness', `fear', `anger' and `peace' were presented individually to 99 adult
participants. Participants rated the intensity of felt emotions as well as the
pleasantness and arousal induced by each excerpt. Mean intensity ratings of target
emotions were highest for 20 out of 25 excerpts. Pleasantness and arousal ratings
led to three main clusters within the two-dimensional circumplex space. Preference
for classical music significantly influenced specificity and intensity ratings
across categories. Absorption trait significantly correlated with arousal ratings
only. In sum, instrumental music appears effective for the induction of basic
emotions in adult listeners. However, careful screening of participants in terms of
their musical preferences should be mandatory.
We report the B abundances and isotopic ratios of two olivine grains from the S‐type asteroid Itokawa sampled by the Hayabusa spacecraft. Olivine grains from the Dar al Gani (DaG) 989 LL6 chondrite ...were used as a reference. Since we analyzed polished thin sections in both cases, we expect the contribution from the solar wind B (rich in 10B) to be minimal because the solar wind was implanted only within very thin layers of the grain surface. The Itokawa and DaG 989 olivine grains have homogeneous B abundances (~400 ppb) and 11B/10B ratios compatible with the terrestrial standard and bulk chondrites. The observed homogeneous B abundances and isotopic ratios of the Itokawa olivine grains are likely the result of thermal metamorphism which occurred in the parent asteroid of Itokawa, which had a similar composition as LL chondrites. The chondritic B isotopic ratios of the Itokawa samples suggest that they contain little cosmogenic B (from cosmic‐ray spallation reactions) rich in 10B. This observation is consistent with the short cosmic‐ray exposure ages of Itokawa samples inferred from the small concentrations of cosmogenic 21Ne. If other Itokawa samples have little cosmogenic B as well, the enrichment in 10B found previously on the surface of another Itokawa particle (as opposed to the bulk grain study here) may be attributed to implanted solar wind B.
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