2,374 research outputs found
SCUBA Observations of the Host Galaxies of Gamma-Ray Bursts
In recent years, a population of galaxies with huge infrared luminosities and dust masses has been discovered in the submillimetre. Observations suggest that the AGN contribution to the luminosities of these submillimetre-selected galaxies is low; instead their luminosities are thought to be mainly due to strong episodes of star formation following merger events. Our current understanding of GRBs as the endpoints in the life of massive stars suggest that they will be located in such galaxies.We have observed a sample of well-located GRB host galaxies in the submillimetre. Comparing the results with the general submillimetre-selected galaxy population, we find that at low fluxes (S850 †4 mJy), the two agree well. However, there is a lack of bright GRB hosts in the submillimetre. This finding is reinforced when the results of other groups are included. Possible explanations are discussed. These results help us assess the roles of both GRB host galaxies and submillimetre-selected galaxies in the evolution of the Universe
On baryon resonances and chiral symmetry
We study J^P=(3/2)^- baryon resonances as generated by chiral coupled-channel
dynamics. Parameter free results are obtained in terms of the Weinberg-Tomozawa
term predicting the leading s-wave interaction strength of Goldstone bosons
with baryon-decuplet states. In the 'heavy' SU(3) limit with m_\pi = m_K \sim
500 MeV the resonances turn into bound states forming a decuplet and octet
representation of the SU(3) group. Using physical masses the mass splitting are
remarkably close to the empirical pattern.Comment: revised version: includes two additional references, gives improved
discussions and eliminted some misprint
What is the association between childhood adversity and subsequent chronic pain in adulthood? A systematic review
Funding: NHS Education for Scotland. KN was academic fellow from 2018 to 2022. SEEM was funded through an academic clinical fellowship from the Scottish Government's Chief Scientist Office (CSO grant number CAF_17_06). DS is a fellow on the Multimorbidity Doctoral Training Programme for Health Professionals, which is supported by the Wellcome Trust [grant number 223499/Z/21/Z].Background Adverse childhood experiences and chronic pain are complex problems affecting millions of people worldwide, and result in significant healthcare utilisation. Our review aimed to determine known associations between adversity in childhood and chronic pain in adulthood. Methods We performed a prospectively registered systematic review (PROSPERO ID: 135625). Six electronic databases (Pubmed, Medline, Cochrane, Scopus, APA PsycNet, Web of Science) were searched from January 1, 2009 until May 30, 2022. Titles and abstracts were screened, and all original research studies examining associations between adverse childhood experiences and chronic pain in adulthood were considered for inclusion. Full texts were reviewed, and a narrative synthesis was used to identify themes from extracted data. Ten percent of studies were dual reviewed to assess inter-rater reliability. Quality assessment of study methodology was undertaken using recognised tools. Results Sixty-eight eligible studies describing 196 130 participants were included. Studies covered 15 different types of childhood adversity and 10 different chronic pain diagnoses. Dual reviewed papers had a Cohen's kappa reliability rating of 0.71. Most studies were of retrospective nature and of good quality. There were consistent associations between adverse childhood experiences and chronic pain in adulthood, with a âdoseâ-dependent relationship. Poor mental health was found to mediate the detrimental connection between adverse childhood experiences and chronic pain. Conclusion A strong association was found between adverse childhood experiences and chronic pain in adulthood. Adverse childhood experiences should be considered in patient assessment, and early intervention to prevent adverse childhood experiences may help reduce the genesis of chronic pain. Further research into assessment and interventions to address adverse childhood experiences is needed.Publisher PDFPeer reviewe
Women, anger, and aggression an interpretative phenomenological analysis
This study reports a qualitative phenomenological investigation of anger and anger-related aggression in the context of the lives of individual women. Semistructured interviews with five women are analyzed using interpretative phenomenological analysis. This inductive approach aims to capture the richness and complexity of the lived experience of emotional life. In particular, it draws attention to the context-dependent and relational dimension of angry feelings and aggressive behavior. Three analytic themes are presented here: the subjective experience of anger, which includes the perceptual confusion and bodily change felt by the women when angry, crying, and the presence of multiple emotions; the forms and contexts of aggression, paying particular attention to the range of aggressive strategies used; and anger as moral judgment, in particular perceptions of injustice and unfairness. The authors conclude by examining the analytic observations in light of phenomenological thinking
Investigation of optical periodic poling techniques in strontium barium niobate (SBN)
Periodic Poling of nonlinear optical materials into spatially alternating domain structures, is a successful method of achieving quasi-phase-matching in materials that are not readily phase-matched via conventional birefringent techniques. Of particular interest to the optics community are ferroelectric materials such as LiNbO3 that possess large nonlinear optical coefficients. We extend the discussion here to include other materials such as SBN and BaTiO3, which show good potential for periodic poling, but produced rather than via fixed electrode arrays. Our optical periodic poling uses Cerium doped Strontium Barium Niobate (SrxBa1-xN) (x =63 or 75) in which an optical grating is generated via two beam interference. The crystal properties are modified by the alternating light and dark intensity patterns, to permit spatially selective domain re-poling to occur, under the appropriate field/intensity parameters. We have investigated this scheme, with particular importance placed on the precise mechanism responsible for optical re-poling. Specifically we find that a number of the mechanisms suggested in the literature are not applicable. We are suggesting a model based on distortion of the local crystal field by photo-ionization of the cerium dopant. The intense local field causes a distortion in the ferroelectric potential of the nearby Niobium ions. Under random excitation of ions, configurations arise which reduce the coercive field of the material. This effect lasts only for the lifetime of the excited ion. We also report on the practical design considerations effecting the optimum conditions for optical periodic poling. We have investigated the optimal wavelength, power, temperature and voltage for poling, and consider the best optical set-up for the system. We further discuss our results on using different non-destructive techniques for visualizing domain
The IL-1RI co-receptor TILRR (FREM1 isoform 2) controls aberrant inflammatory responses and development of vascular disease
Summary
Expression of the interleukin-1 receptor type I (IL-1RI) co-receptor Toll-like and interleukin-1 receptor regulator (TILRR) is significantly increased in blood monocytes following myocardial infarction and in the atherosclerotic plaque, whereas levels in healthy tissue are low. TILRR association with IL-1RI at these sites causes aberrant activation of inflammatory genes, which underlie progression of cardiovascular disease. The authors show that genetic deletion of TILRR or antibody blocking of TILRR function reduces development of atherosclerotic plaques. Lesions exhibit decreased levels of monocytes, with increases in collagen and smooth muscle cells, characteristic features of stable plaques. The results suggest that TILRR may constitute a rational target for site- and signal-specific inhibition of vascular disease
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