Most research on mind-wandering has characterized it as a mental state with contents that are task unrelated or stimulus independent. However, the dynamics of mind-wandering - how mental states ...change over time - have remained largely neglected. Here, we introduce a dynamic framework for understanding mind-wandering and its relationship to the recruitment of large-scale brain networks. We propose that mind-wandering is best understood as a member of a family of spontaneous-thought phenomena that also includes creative thought and dreaming. This dynamic framework can shed new light on mental disorders that are marked by alterations in spontaneous thought, including depression, anxiety and attention deficit hyperactivity disorder.
Summary Background Lifestyle changes soon after diagnosis might improve outcomes in patients with type 2 diabetes mellitus, but no large trials have compared interventions. We investigated the ...effects of diet and physical activity on blood pressure and glucose concentrations. Methods We did a randomised, controlled trial in southwest England in adults aged 30–80 years in whom type 2 diabetes had been diagnosed 5–8 months previously. Participants were assigned usual care (initial dietary consultation and follow-up every 6 months; control group), an intensive diet intervention (dietary consultation every 3 months with monthly nurse support), or the latter plus a pedometer-based activity programme, in a 2:5:5 ratio. The primary endpoint was improvement in glycated haemoglobin A1c (HbA1c ) concentration and blood pressure at 6 months. Analysis was done by intention to treat. This study is registered, number ISRCTN92162869. Findings Of 593 eligible individuals, 99 were assigned usual care, 248 the diet regimen, and 246 diet plus activity. Outcome data were available for 587 (99%) and 579 (98%) participants at 6 and 12 months, respectively. At 6 months, glycaemic control had worsened in the control group (mean baseline HbA1c percentage 6·72, SD 1·02, and at 6 months 6·86, 1·02) but improved in the diet group (baseline-adjusted difference in percentage of HbA1c −0·28%, 95% CI −0·46 to −0·10; p=0·005) and diet plus activity group (−0·33%, −0·51 to −0·14; p<0·001). These differences persisted to 12 months, despite less use of diabetes drugs. Improvements were also seen in bodyweight and insulin resistance between the intervention and control groups. Blood pressure was similar in all groups. Interpretation An intensive diet intervention soon after diagnosis can improve glycaemic control. The addition of an activity intervention conferred no additional benefit. Funding Diabetes UK and the UK Department of Health.
When two-dimensional crystals are brought into close proximity, their interaction results in reconstruction of electronic spectrum and crystal structure. Such reconstruction strongly depends on the ...twist angle between the crystals, which has received growing attention due to interesting electronic and optical properties that arise in graphene and transitional metal dichalcogenides. Here we study two insulating crystals of hexagonal boron nitride stacked at small twist angle. Using electrostatic force microscopy, we observe ferroelectric-like domains arranged in triangular superlattices with a large surface potential. The observation is attributed to interfacial elastic deformations that result in out-of-plane dipoles formed by pairs of boron and nitrogen atoms belonging to opposite interfacial surfaces. This creates a bilayer-thick ferroelectric with oppositely polarized (BN and NB) dipoles in neighbouring domains, in agreement with our modeling. These findings open up possibilities for designing van der Waals heterostructures and offer an alternative probe to study moiré-superlattice electrostatic potentials.
The neural basis and cognitive functions of various spontaneous thought processes, particularly mind-wandering, are increasingly being investigated. Although strong links have been drawn between the ...occurrence of spontaneous thought processes and activation in brain regions comprising the default mode network (DMN), spontaneous thought also appears to recruit other, non-DMN regions just as consistently. Here we present the first quantitative meta-analysis of neuroimaging studies of spontaneous thought and mind-wandering in order to address the question of their neural correlates. Examining 24 functional neuroimaging studies of spontaneous thought processes, we conducted a meta-analysis using activation likelihood estimation (ALE). A number of key DMN areas showed consistent recruitment across studies, including medial prefrontal cortex, posterior cingulate cortex, medial temporal lobe, and bilateral inferior parietal lobule. Numerous non-DMN regions, however, were also consistently recruited, including rostrolateral prefrontal cortex, dorsal anterior cingulate cortex, insula, temporopolar cortex, secondary somatosensory cortex, and lingual gyrus. These meta-analytic results indicate that DMN activation alone is insufficient to adequately capture the neural basis of spontaneous thought; frontoparietal control network areas, and other non-DMN regions, appear to be equally central. We conclude that further progress in the cognitive and clinical neuroscience of spontaneous thought will therefore require a re-balancing of our view of the contributions of various regions and networks throughout the brain, and beyond the DMN.
•Spontaneous thought (e.g., mind-wandering) is closely linked to the default network.•Spontaneous thought also appears to recruit other, non-default network regions.•We review and meta-analyze all neuroimaging studies of spontaneous thought (n=24).•We find consistent activations in both default and executive network regions.•Future studies should not restrict analyses to default network regions-of-interest.
Africa, the ancestral home of all modern humans, is the most informative continent for understanding the human genome and its contribution to complex disease. To better understand the genetics of ...schizophrenia, we studied the illness in the Xhosa population of South Africa, recruiting 909 cases and 917 age-, gender-, and residence-matched controls. Individuals with schizophrenia were significantly more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function, including neural circuitry mediated by the neurotransmitters glutamine, γ-aminobutyric acid, and dopamine. Schizophrenia is genetically highly heterogeneous, involving severe ultrarare mutations in genes that are critical to synaptic plasticity. The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide.
Metamaterials are artificial materials with subwavelength structure that enable the translation of magnetic and electric responses into spectral regions not accessible through naturally occurring ...materials. Here, we report direct measurements of the propagation and confinement of terahertz electromagnetic surface modes tightly bound to flat plasmonic metamaterials that consist of metal surfaces decorated with two-dimensional arrays of subwavelength-periodicity pits. These modes are surface plasmon polaritons with an effective plasma frequency controlled entirely by the surface geometry. The mode spectrum and penetration depth into air demonstrate strong wavelength-scale energy confinement to the surface below the electromagnetic band edge; this is in stark contrast to the very weak confinement found at flat metal surfaces in this spectral regime. The results are in good agreement with analytical and numerical models of surface plasmon polaritons propagating on structured perfect-conductor surfaces, and imply that plasmonic metamaterials could help miniaturize optical components or lead to improved chemical or biochemical sensors.
Affective neuroscience of self‐generated thought Fox, Kieran C.R.; Andrews‐Hanna, Jessica R.; Mills, Caitlin ...
Annals of the New York Academy of Sciences,
August 2018, Letnik:
1426, Številka:
1
Journal Article
Recenzirano
Despite increasing scientific interest in self‐generated thought—mental content largely independent of the immediate environment—there has yet to be any comprehensive synthesis of the subjective ...experience and neural correlates of affect in these forms of thinking. Here, we aim to develop an integrated affective neuroscience encompassing many forms of self‐generated thought—normal and pathological, moderate and excessive, in waking and in sleep. In synthesizing existing literature on this topic, we reveal consistent findings pertaining to the prevalence, valence, and variability of emotion in self‐generated thought, and highlight how these factors might interact with self‐generated thought to influence general well‐being. We integrate these psychological findings with recent neuroimaging research, bringing attention to the neural correlates of affect in self‐generated thought. We show that affect in self‐generated thought is prevalent, positively biased, highly variable (both within and across individuals), and consistently recruits many brain areas implicated in emotional processing, including the orbitofrontal cortex, amygdala, insula, and medial prefrontal cortex. Many factors modulate these typical psychological and neural patterns, however; the emerging affective neuroscience of self‐generated thought must endeavor to link brain function and subjective experience in both everyday self‐generated thought as well as its dysfunctions in mental illness.
Despite increasing scientific interest in self‐generated thought – mental content largely independent of the immediate environment – there has yet to be any comprehensive synthesis of the subjective experience and neural correlates of affect in these forms of thinking. This review aims to develop an integrated affective neuroscience encompassing many forms of self‐generated thought – normal and pathological, moderate and excessive, in waking and in sleep.
Abstract
With the conclusion of the third observing run for Advanced LIGO/Virgo (O3), we present a detailed analysis of both triggered and serendipitous observations of 17 gravitational-wave (GW) ...events (7 triggered and 10 purely serendipitous) from the Searches After Gravitational-waves Using ARizona Observatories (SAGUARO) program. We searched a total of 4935 deg
2
down to a median 5
σ
transient detection depth of 21.1 AB mag using the Mt. Lemmon 1.5 m telescope, the discovery engine for SAGUARO. In addition to triggered events within 24 hr, our transient search encompassed a time interval following GW events of <120 hr, providing observations on ∼1/2 of the events accessible to the Mt. Lemmon 1.5 m telescope. We covered 2.1%–86% of the LVC total probability (
P
total
) for individual events, with a median
P
total
≈ 8% within <120 hr. Following improvements to our pipeline and the addition of serendipitous observations, we find a total of seven new optical candidates across five GW events, which we are unable to rule out after searching for additional information and comparing to kilonova models. Using both publicly available and our own late-time data, we investigated a total of 252 optical candidates for these 17 events, finding that only 65% were followed up in some capacity by the community. Of the total 252 candidates, we are able to rule out an additional 12 previously reported counterpart candidates. In light of these results, we discuss lessons learned from the SAGUARO GW counterpart search. We discuss how community coordination of observations and candidate follow-up, as well as the role of archival data, are crucial to improving the efficiency of follow-up efforts and preventing unnecessary duplication of effort with limited electromagnetic resources.
It is unclear whether diet affects glycaemic control in type 2 diabetes (T2D), over and above its effects on bodyweight. We aimed to assess whether changes in dietary patterns altered glycaemic ...control independently of effects on bodyweight in newly diagnosed T2D.
We used data from 4-day food diaries, HbA1c and potential confounders in participants of the Early-ACTivity-In-Diabetes trial measured at 0, 6 and 12 months. At baseline, a 'carb/fat balance' dietary pattern and an 'obesogenic' dietary pattern were derived using reduced-rank regression, based on hypothesised nutrient-mediated mechanisms linking dietary intake to glycaemia directly or via obesity. Relationships between 0 and 6 month change in dietary pattern scores and baseline-adjusted HbA1c at 6 months (n = 242; primary outcome) were assessed using multivariable linear regression. Models were repeated for periods 6-12 months and 0-12 months (n = 194 and n = 214 respectively; secondary outcomes).
Reductions over 0-6 months were observed in mean bodyweight (- 2.3 (95% CI: - 2.7, - 1.8) kg), body mass index (- 0.8 (- 0.9, - 0.6) kg/m
), energy intake (- 788 (- 953, - 624) kJ/day), and HbA1c (- 1.6 (- 2.6, -0.6) mmol/mol). Weight loss strongly associated with lower HbA1c at 0-6 months (β = - 0.70 95% CI - 0.95, - 0.45 mmol/mol/kg lost). Average fat and carbohydrate intakes changed to be more in-line with UK healthy eating guidelines between 0 and 6 months. Dietary patterns shifting carbohydrate intakes higher and fat intakes lower were characterised by greater consumption of fresh fruit, low-fat milk and boiled/baked potatoes and eating less of higher-fat processed meats, butter/animal fats and red meat. Increases in standardised 'carb/fat balance' dietary pattern score associated with improvements in HbA1c at 6 months independent of weight loss (β = - 1.54 - 2.96, - 0.13 mmol/mol/SD). No evidence of association with HbA1c was found for this dietary pattern at other time-periods. Decreases in 'obesogenic' dietary pattern score were associated with weight loss (β = - 0.77 - 1.31, - 0.23 kg/SD) but not independently with HbA1c during any period.
Promoting weight loss should remain the primary nutritional strategy for improving glycaemic control in early T2D. However, improving dietary patterns to bring carbohydrate and fat intakes closer to UK guidelines may provide small, additional improvements in glycaemic control.
ISRCTN92162869 . Retrospectively registered on 25 July 2005.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Galaxy And Mass Assembly (GAMA) survey is one of the largest contemporary spectroscopic surveys of low redshift galaxies. Covering an area of ∼286 deg2 (split among five survey regions) down to a ...limiting magnitude of r < 19.8 mag, we have collected spectra and reliable redshifts for 238 000 objects using the AAOmega spectrograph on the Anglo-Australian Telescope. In addition, we have assembled imaging data from a number of independent surveys in order to generate photometry spanning the wavelength range 1 nm–1 m. Here, we report on the recently completed spectroscopic survey and present a series of diagnostics to assess its final state and the quality of the redshift data. We also describe a number of survey aspects and procedures, or updates thereof, including changes to the input catalogue, redshifting and re-redshifting, and the derivation of ultraviolet, optical and near-infrared photometry. Finally, we present the second public release of GAMA data. In this release, we provide input catalogue and targeting information, spectra, redshifts, ultraviolet, optical and near-infrared photometry, single-component Sérsic fits, stellar masses, Hα-derived star formation rates, environment information, and group properties for all galaxies with r < 19.0 mag in two of our survey regions, and for all galaxies with r < 19.4 mag in a third region (72 225 objects in total). The data base serving these data is available at http://www.gama-survey.org/.
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