89 research outputs found
Watching movies unfold - a frame-by-frame analysis of the associated neural dynamics
Our lives unfold as sequences of events. We experience these events as seamless, although they are composed of individual images captured in between the interruptions imposed by eye blinks and saccades. Events typically involve visual imagery from the real world (scenes), and the hippocampus is frequently engaged in this context. It is unclear, however, whether the hippocampus would be similarly responsive to unfolding events that involve abstract imagery. Addressing this issue could provide insights into the nature of its contribution to event processing, with relevance for theories of hippocampal function. Consequently, during magnetoencephalography (MEG), we had female and male humans watch highly matched unfolding movie events composed of either scene image frames that reflected the real world, or frames depicting abstract patterns. We examined the evoked neuronal responses to each image frame along the time course of the movie events. Only one difference between the two conditions was evident, and that was during the viewing of the first image frame of events, detectable across frontotemporal sensors. Further probing of this difference using source reconstruction revealed greater engagement of a set of brain regions across parietal, frontal, premotor, and cerebellar cortices, with the largest change in broadband (1–30 Hz) power in the hippocampus during scene-based movie events. Hippocampal engagement during the first image frame of scene-based events could reflect its role in registering a recognizable context perhaps based on templates or schemas. The hippocampus, therefore, may help to set the scene for events very early on
Neuronal characteristics of small-cell lung cancer
Wide ranging experimental evidence suggests that human small-cell lung cancer (SCLC) has a number of molecular and subcellular characteristics normally associated with neurones. This review outlines and discusses these characteristics in the light of recent developments in the field. Emphasis is placed upon neuronal cell adhesion molecules, neurone-restrictive silencer factor, neurotransmitters/peptides and voltage-gated ion, especially Na+ channels. The hypothesis is put forward that acquisition of such characteristics and the membrane ‘excitability' that would follow can accelerate metastatic progression. The clinical potential of the neuronal characteristics of SCLC, in particular ion channel expression/activity, is discussed in relation to possible novel diagnostic and therapeutic modalities
Systems of Differential Algebraic Equations in Computational Electromagnetics
Starting from space-discretisation of Maxwell's equations, various classical
formulations are proposed for the simulation of electromagnetic fields. They
differ in the phenomena considered as well as in the variables chosen for
discretisation. This contribution presents a literature survey of the most
common approximations and formulations with a focus on their structural
properties. The differential-algebraic character is discussed and quantified by
the differential index concept
Suicide attempts and related factors in patients admitted to a general hospital: a ten-year cross-sectional study (1997-2007)
[Abstract] Background: Suicide and suicide attempts represent a severe problem for public health services. The aim of this study is to determine the socio-demographic and psychopathological variables associated with suicide attempts in the population admitted to a General Hospital.
Methods: An observational-descriptive study of patients admitted to the A Coruña University Hospital (Spain) during the period 1997-2007, assessed by the Consultation and Liaison Psychiatric Unit. We include n = 5,234 admissions from 4,509 patients. Among these admissions, n = 361 (6.9%) were subsequent to a suicide attempt. Admissions arising from a suicide attempt were compared with admissions occurring due to other reasons.Multivariate generalised estimating equation logistic regression models were used to examine factors associated with suicide attempts.
Results: Adjusting by age, gender, educational level, cohabitation status, being employed or unemployed, the psychiatric diagnosis at the time of the interview and the information on previous suicide attempts, we found that the variables associated with the risk of a suicide attempt were: age, psychiatric diagnosis and previous suicide attempts. The risk of suicide attempts decreases with age (OR = 0.969). Psychiatric diagnosis was associated with a higher risk of suicide attempts, with the highest risk being found for Mood or Affective Disorders (OR = 7.49), followed by Personality Disorders (OR = 7.31), and Schizophrenia and Other Psychotic Disorders (OR = 5.03).The strongest single predictive factor for suicide attempts was a prior history of attempts (OR = 23.63).
Conclusions: Age, psychopathological diagnosis and previous suicide attempts are determinants of suicide attempts
Global urban environmental change drives adaptation in white clover.
Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale
Measurement of the tt̄W and tt̄Z production cross sections in pp collisions at √s = 8 TeV with the ATLAS detector
The production cross sections of top-quark pairs in association with massive vector bosons have been measured using data from pp collisions at s√ = 8 TeV. The dataset corresponds to an integrated luminosity of 20.3 fb−¹ collected by the ATLAS detector in 2012 at the LHC. Final states with two, three or four leptons are considered. A fit to the data considering the tt̄W and tt̄Z processes simultaneously yields a significance of 5.0σ (4.2σ) over the background-only hypothesis for tt¯Wtt¯W (tt̄Z) production. The measured cross sections are σtt̄W = 369 + 100−91 fb and σtt̄Z = 176 + 58−52 fb. The background-only hypothesis with neither tt̄W nor tt̄Z production is excluded at 7.1σ. All measurements are consistent with next-to-leading-order calculations for the tt̄W and tt̄Z processes
Sleep-amount differentially affects fear-processing neural circuitry in pediatric anxiety: A preliminary fMRI investigation
Insufficient sleep, as well as the incidence of anxiety disorders, both peak during adolescence. While both conditions present perturbations in fear-processing-related neurocircuitry, it is unknown whether these neurofunctional alterations directly link anxiety and compromised sleep in adolescents. Fourteen anxious adolescents (AAs) and 19 healthy adolescents (HAs) were compared on a measure of sleep amount and neural responses to negatively valenced faces during fMRI. Group differences in neural response to negative faces emerged in the dorsal anterior cingulate cortex (dACC) and the hippocampus. In both regions, correlation of sleep amount with BOLD activation was positive in AAs, but negative in HAs. Follow-up psychophysiological interaction (PPI) analyses indicated positive connectivity between dACC and dorsomedial prefrontal cortex, and between hippocampus and insula. This connectivity was correlated negatively with sleep amount in AAs, but positively in HAs. In conclusion, the presence of clinical anxiety modulated the effects of sleep-amount on neural reactivity to negative faces differently among this group of adolescents, which may contribute to different clinical significance and outcomes of sleep disturbances in healthy adolescents and patients with anxiety disorders
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