51 research outputs found
North-Sea basement and provenance of the Permian Rotliegend Group
Conglomerates and sandstones from the Permian Rotliegend Group contain clasts of Caledonian origin that suggests a basement source area and a sediment transport direction connected to the tectonic activity in Carboniferous and Permian time. The existing outline of the basement rocks in the Norwegian North Sea was incomplete, and therefore a new map of the basement lithologies was made based on core viewing and interpretations of crystalline thin sections from the Norwegian sector. Possible source areas and transport directions for Permian deposits were indicated based on point counting and core viewing of sandstones and conglomerates in the southern and western Norwegian North Sea with a specific focus on lithic fragments. The southern part of the Norwegian sector indicates phyllite and schist, whereas monzogranite, quartz-monzonite, monzodiorite, diorite, metasedimentary and mafic plutonic rocks, gneiss and andesite were identified in the western sector in the Norwegian North Sea. The cores and thin sections from the basement from the northern Norwegian sector show an abundance of dark gneiss. The crystalline clasts composed of monzogranite in conglomerates and sandstones in section 16 and 25 on the Utsira High suggests that the granitic area in sector 16 on the Utsira High acted as a source area to these Permian Rotliegend sedimentary rocks, resulting in a main sediment transport direction towards N-NW. The Rotliegend conglomerates also suggest that the underlying basement rock can act as a source rock due to fault activity. As a conclusion, the map of the basement lithologies and the interpretations of lithic fragments in Rotliegend sandstones and conglomerates are useful aids in reconstructing the post-Variscan sediment transport direction in the southern and western sectors of the Norwegian North Sea
Development of social feedback processing and responses in childhood:an fMRI test-replication design in two age cohorts
This study investigated behavioral and neural correlates underlying social feedback processing and subsequent aggressive behaviors in childhood in two age cohorts (test sample: n = 509/n = 385 and replication sample: n = 354/n = 195, 7-9 years old). Using a previously validated Social Network Aggression Task, we showed that negative social feedback resulted in most behavioral aggression, followed by less aggression after neutral and least aggression after positive feedback. Receiving positive and negative social feedback was associated with increased activity in the insula, medial prefrontal cortex and ventrolateral prefrontal cortex. Responding to feedback was associated with additional activation in the dorsolateral prefrontal cortex (DLPFC) following positive feedback. This DLPFC activation correlated negatively with aggression. Furthermore, age analyses showed that older children showed larger reductions in aggression following positive feedback and more neural activation in the DLPFC when responding to positive feedback compared to younger children. To assess the robustness of our results, we examined these processes in two independent behavioral/functional magnetic resonance imaging samples using equivalence testing, thereby contributing to replicable reports. Together, these findings demonstrate an important role of social saliency and regulatory processes where regulation of aggression rapidly develops between the ages of 7 and 9 years.</p
Longitudinal changes in DLPFC activation during childhood are related to decreased aggression following social rejection
Regulating aggression after social feedback is an important prerequisite for developing and maintaining social relations, especially in the current times with larger emphasis on online social evaluation. Studies in adults highlighted the role of the dorsolateral prefrontal cortex (DLPFC) in regulating aggression. Little is known about the development of aggression regulation following social feedback during childhood, while this is an important period for both brain maturation and social relations. The current study used a longitudinal design, with 456 twins undergoing two functional MRI sessions across the transition from middle (7 to 9 y) to late (9 to 11 y) childhood. Aggression regulation was studied using the Social Network Aggression Task. Behavioral aggression after social evaluation decreased over time, whereas activation in the insula, dorsomedial PFC and DLPFC increased over time. Brain-behavior analyses showed that increased DLPFC activation after negative feedback was associated with decreased aggression. Change analyses further revealed that children with larger increases in DLPFC activity from middle to late childhood showed stronger decreases in aggression over time. These findings provide insights into the development of social evaluation sensitivity and aggression control in childhood
Genetic and environmental influences on structure of the social brain in childhood
Prosocial behavior and empathy are important aspects of developing social relations in childhood. Prior studies showed protracted structural development of social brain regions associated with prosocial behavior. However, it remains unknown how structure of the social brain is influenced by genetic or environmental factors, and whether overlapping heritability factors explain covariance in structure of the social brain and behavior. The current study examined this hypothesis in a twin sample (aged 7–9-year; N = 512). Bilateral measures of surface area and cortical thickness of the medial prefrontal cortex (mPFC), temporo-parietal junction (TPJ), posterior superior temporal sulcus (pSTS), and precuneus were analyzed. Results showed genetic contributions to surface area and cortical thickness for all brain regions. We f
Pain assessment for people with dementia: a systematic review of systematic reviews of pain assessment tools.
BACKGROUND: There is evidence of under-detection and poor management of pain in patients with dementia, in both long-term and acute care. Accurate assessment of pain in people with dementia is challenging and pain assessment tools have received considerable attention over the years, with an increasing number of tools made available. Systematic reviews on the evidence of their validity and utility mostly compare different sets of tools. This review of systematic reviews analyses and summarises evidence concerning the psychometric properties and clinical utility of pain assessment tools in adults with dementia or cognitive impairment. METHODS: We searched for systematic reviews of pain assessment tools providing evidence of reliability, validity and clinical utility. Two reviewers independently assessed each review and extracted data from them, with a third reviewer mediating when consensus was not reached. Analysis of the data was carried out collaboratively. The reviews were synthesised using a narrative synthesis approach. RESULTS: We retrieved 441 potentially eligible reviews, 23 met the criteria for inclusion and 8 provided data for extraction. Each review evaluated between 8 and 13 tools, in aggregate providing evidence on a total of 28 tools. The quality of the reviews varied and the reporting often lacked sufficient methodological detail for quality assessment. The 28 tools appear to have been studied in a variety of settings and with varied types of patients. The reviews identified several methodological limitations across the original studies. The lack of a 'gold standard' significantly hinders the evaluation of tools' validity. Most importantly, the samples were small providing limited evidence for use of any of the tools across settings or populations. CONCLUSIONS: There are a considerable number of pain assessment tools available for use with the elderly cognitive impaired population. However there is limited evidence about their reliability, validity and clinical utility. On the basis of this review no one tool can be recommended given the existing evidence
Neural and behavioral signatures of social evaluation and adaptation in childhood and adolescence: The Leiden consortium on individual development (L-CID)
The transition period between early childhood and late adolescence is characterized by pronounced changes in social competence, or the capacity for flexible social adaptation. Here, we propose that two processes, self-control and prosociality, are crucial for social adaptation following social evaluation. We present a neurobehavioral model showing commonalities in neural responses to experiences of social acceptance and rejection, and multiple pathways for responding to social context. The Leiden Consortium on Individual Development (L-CID) provides a comprehensive approach towards understanding the longitudinal developmental pathways of, and social enrichment effects on, social competence, taking into account potential differential effects of such enrichment. Using Neurosynth based brain maps we point towards the medial prefrontal cortex as an important region integrating social cognition, self-referential processing and self-control for learning to respond flexibly to changing social contexts. Based on their role in social evaluation processing, we suggest to examine medial prefrontal cortex connections with lateral prefrontal cortex and the ventral striatum as potential neural differential susceptibility markers, in addition to previously established markers of differential susceptibility
Factors controlling plankton community production, export flux, and particulate matter stoichiometry in the coastal upwelling system off Peru
Eastern boundary upwelling systems (EBUS) are among the most productive marine ecosystems on Earth. The production of organic material is fueled by upwelling of nutrient-rich deep waters and high incident light at the sea surface. However, biotic and abiotic factors can modify surface production and related biogeochemical processes. Determining these factors is important because EBUS are considered hotspots of climate change, and reliable predictions of their future functioning requires understanding of the mechanisms driving the biogeochemical cycles therein. In this field experiment, we used in situ mesocosms as tools to improve our mechanistic understanding of processes controlling organic matter cycling in the coastal Peruvian upwelling system. Eight mesocosms, each with a volume of ∼55 m3, were deployed for 50 d ∼6 km off Callao (12∘ S) during austral summer 2017, coinciding with a coastal El Niño phase. After mesocosm deployment, we collected subsurface waters at two different locations in the regional oxygen minimum zone (OMZ) and injected these into four mesocosms (mixing ratio ≈1.5 : 1 mesocosm: OMZ water). The focus of this paper is on temporal developments of organic matter production, export, and stoichiometry in the individual mesocosms. The mesocosm phytoplankton communities were initially dominated by diatoms but shifted towards a pronounced dominance of the mixotrophic dinoflagellate (Akashiwo sanguinea) when inorganic nitrogen was exhausted in surface layers. The community shift coincided with a short-term increase in production during the A. sanguinea bloom, which left a pronounced imprint on organic matter C : N : P stoichiometry. However, C, N, and P export fluxes did not increase because A. sanguinea persisted in the water column and did not sink out during the experiment. Accordingly, export fluxes during the study were decoupled from surface production and sustained by the remaining plankton community. Overall, biogeochemical pools and fluxes were surprisingly constant for most of the experiment. We explain this constancy by light limitation through self-shading by phytoplankton and by inorganic nitrogen limitation which constrained phytoplankton growth. Thus, gain and loss processes remained balanced and there were few opportunities for blooms, which represents an event where the system becomes unbalanced. Overall, our mesocosm study revealed some key links between ecological and biogeochemical processes for one of the most economically important regions in the oceans
The biogeochemical impact of glacial meltwater from Southwest Greenland
Biogeochemical cycling in high-latitude regions has a disproportionate impact on global nutrient budgets. Here, we introduce a holistic, multi-disciplinary framework for elucidating the influence of glacial meltwaters, shelf currents, and biological production on biogeochemical cycling in high-latitude continental margins, with a focus on the silica cycle. Our findings highlight the impact of significant glacial discharge on nutrient supply to shelf and slope waters, as well as surface and benthic production in these regions, over a range of timescales from days to thousands of years. Whilst biological uptake in fjords and strong diatom activity in coastal waters maintains low dissolved silicon concentrations in surface waters, we find important but spatially heterogeneous additions of particulates into the system, which are transported rapidly away from the shore. We expect the glacially-derived particles – together with biogenic silica tests – to be cycled rapidly through shallow sediments, resulting in a strong benthic flux of dissolved silicon. Entrainment of this benthic silicon into boundary currents may supply an important source of this key nutrient into the Labrador Sea, and is also likely to recirculate back into the deep fjords inshore. This study illustrates how geochemical and oceanographic analyses can be used together to probe further into modern nutrient cycling in this region, as well as the palaeoclimatological approaches to investigating changes in glacial meltwater discharge through time, especially during periods of rapid climatic change in the Late Quaternary
Behavioral and neural responses to social rejection:Individual differences in developmental trajectories across childhood and adolescence
Dealing with social rejection is challenging, especially during childhood when behavioral and neural responses to social rejection are still developing. In the current longitudinal study, we used a Bayesian multilevel growth curve model to describe individual differences in the development of behavioral and neural responses to social rejection in a large sample (n > 500). We found a peak in aggression following negative feedback (compared to neutral feedback) during late childhood, as well as individual differences during this developmental phase, possibly suggesting a sensitive window for dealing with social rejection across late childhood. Moreover, we found evidence for individual differences in the linear development of neural responses to social rejection in our three brain regions of interest: The anterior insula, the medial prefrontal cortex, and the dorsolateral prefrontal cortex. In addition to providing insights in the individual trajectories of dealing with social rejection during childhood, this study also makes a meaningful methodological contribution: Our statistical analysis strategy (and online supplementary information) can be used as an example on how to take into account the many complexities of developmental neuroimaging datasets, while still enabling researchers to answer interesting questions about individual-level relationships.</p
Longitudinal changes in DLPFC activation during childhood are related to decreased aggression following social rejection
Michelle Achterberg, Anna C.K. van Duijvenvoorde, Marinus H. van IJzendoorn, Marian J. Bakermans-Kranenburg, & Eveline Crone (2020). Proceedings of the National Academy of Sciences of the United States of America
- …