scispace - formally typeset
Search or ask a question
Institution

University of St Andrews

EducationSt Andrews, Fife, United Kingdom
About: University of St Andrews is a education organization based out in St Andrews, Fife, United Kingdom. It is known for research contribution in the topics: Population & Laser. The organization has 16260 authors who have published 43364 publications receiving 1636072 citations. The organization is also known as: St Andrews University & University of St. Andrews.
Topics: Population, Laser, Planet, Galaxy, Stars


Papers
More filters
Journal ArticleDOI
21 Dec 2006-Nature
TL;DR: Zhang et al. as discussed by the authors reported that GRB 060614 was not accompanied by supernova emission down to limits hundreds of times fainter than the archetypal supernova SN 1998bw that accompanied GRB 980425, and faintter than any type Ic supernova ever observed.
Abstract: The tidy classification system that divided γ-ray bursts (GRBs) into long-duration busts (lasting more than two seconds) and short may have had its day. The final nail in its coffin may be GRB 060614. Discovered on 14 June 2006 by the Burst Alert Telescope on-board the Swift satellite, this burst was long, at 102 seconds, but as reported in a clutch of papers in this issue, it has a number of properties, including the absence of an accompanying supernova, that were previously considered diagnostic of a 'short' GRB. The hunt is now on for a classification system to take account of the diversity now apparent in GRBs. In the accompanying News & Views, Bing Zhang suggests that the answer may be to adopt a Type I/Type II classification similar to that used for supernovae. GRB 060505 and GRB 060614 were not accompanied by supernova emission down to limits hundreds of times fainter than the archetypal SN 1998bw that accompanied GRB 980425, and fainter than any type Ic supernova ever observed. It is now accepted that long-duration γ-ray bursts (GRBs) are produced during the collapse of a massive star1,2. The standard ‘collapsar’ model3 predicts that a broad-lined and luminous type Ic core-collapse supernova accompanies every long-duration GRB4. This association has been confirmed in observations of several nearby GRBs5–9. Here we report that GRB 060505 (ref. 10) and GRB 060614 (ref. 11) were not accompanied by supernova emission down to limits hundreds of times fainter than the archetypal supernova SN 1998bw that accompanied GRB 980425, and fainter than any type Ic supernova ever observed12. Multi-band observations of the early afterglows, as well as spectroscopy of the host galaxies, exclude the possibility of significant dust obscuration and show that the bursts originated in actively star-forming regions. The absence of a supernova to such deep limits is qualitatively different from all previous nearby long-duration GRBs and suggests a new phenomenological type of massive stellar death.

467 citations

Journal ArticleDOI
TL;DR: This paper found that ERPs to the semantic primes were more negative-going than those to targets, and the difference peaked around 400-450 ms after stimulus onset, with a similar scalp topography.
Abstract: Event-related potentials (ERPs) were recorded during the performance of a lexical decision task, in which a proportion of the words were either semantic associates or repetitions of the preceding word. Reaction times were faster to both the second member of associated pairs (targets) and repeated words, with the latter facilitatory effect being more than twice that of the former. ERPs to the semantic primes were more negative-going than those to targets. This difference peaked around 400–450 ms after stimulus onset. Comparison of unrepeated and repeated words revealed a larger and temporally more extended difference, with a similar scalp topography. The prime-target differences are interpreted as a further example of the sensitivity of the ‘N400’ component of the ERP to semantic relationships between words. The differences between the repetition and priming effects in ERPs are considered equivocal with respect to the view that the associated behavioural effects are caused by different cognitive mechanisms.

467 citations

Journal ArticleDOI
TL;DR: The way animals move has important consequences for the degree of mixing that the authors expect to find both within a population and between individuals of different species, and as most animals revisit some places and avoid others based on their previous experiences, they foresee the incorporation of long-term memory and intention in movement models.
Abstract: While the mechanistic links between animal movement and population dynamics are ecologically obvious, it is much less clear when knowledge of animal movement is a prerequisite for understanding and predicting population dynamics. GPS and other technologies enable detailed tracking of animal location concurrently with acquisition of landscape data and information on individual physiology. These tools can be used to refine our understanding of the mechanistic links between behaviour and individual condition through ‘spatially informed’ movement models where time allocation to different behaviours affects individual survival and reproduction. For some species, socially informed models that address the movements and average fitness of differently sized groups and how they are affected by fission–fusion processes at relevant temporal scales are required. Furthermore, as most animals revisit some places and avoid others based on their previous experiences, we foresee the incorporation of long-term memory and intention in movement models. The way animals move has important consequences for the degree of mixing that we expect to find both within a population and between individuals of different species. The mixing rate dictates the level of detail required by models to capture the influence of heterogeneity and the dynamics of intra- and interspecific interaction.

466 citations

Journal ArticleDOI
TL;DR: The recent turn to "strategy practice" offers a genuine opportunity for establishing an alternative perspective that is clearly distinct from the traditional strategy process view as discussed by the authors, and the challenge is to clarify and articulate an alternative set of ontological and epistemological premises for founding this new approach to theorizing strategy.
Abstract: The recent turn to ‘strategy practice’ offers a genuine opportunity for establishing an alternative perspective that is clearly distinct from the traditional strategy process view. The challenge is to clarify and articulate an alternative set of ontological and epistemological premises for founding this new approach to theorizing strategy.What has been called the ‘practice turn’ in social theory provides this alternative basis for a ‘post-processual’ approach to theorizing strategy-as-practice. This ‘practice turn’ involves a radical reformulation of the intractable problem of agency and structure that enables us to bypass the ‘micro/macro’ distinction so intimately tied to the social sciences in general and to strategy research in particular. Already, there are signs that the discourse of the strategy-as-practice research community reflects this awareness and are thus straining towards some form of ‘trans-individual’ explanation that is not restricted to the mere ‘activities’ of strategy actors nor to th...

466 citations

Journal ArticleDOI
TL;DR: It is indicated that NO-donors can directly inhibit the DNA binding activity of NF-kappaB family proteins, suggesting that cellular NO provides another control mechanism for modulating the expression ofNF- kappaB-responsive genes.
Abstract: It has been suggested that the NF-kappaB transcription factor family may mediate expression of the gene encoding the cytokine-inducible form of nitric oxide synthase (iNOS). To establish if nitric oxide (NO) could in turn affect activity of NF-kappaB, the ability of NO-donor compounds to influence NF-kappaB DNA binding activity in vitro was investigated. NO-donor compounds sodium nitroprusside (SNP) and S-nitroso-N-acetylpenicillamine (SNAP) both inhibited the DNA binding activity of recombinant NF-kappaB p50 and p65 homodimers and of p50-p65 heterodimers. Inhibition of NF-kappaB p50 DNA binding by NO-donor compounds involved modification of the conserved redox-sensitive C62 residue, as a C62S p50 mutant was significantly more resistant to SNP-mediated inactivation. Non-reducing SDS-polyacrylamide gel electrophoresis demonstrated that SNP could inhibit p50 DNA binding by mechanisms other than the formation of intersubunit disulphide bonds involving p50 residue C62. Electrospray ionization mass spectrometry of a synthetic NF-kappaB p5O peptide containing the C62 residue suggested that NO gas can modify C62 by S-nitrosylation. This study indicates that NO-donors can directly inhibit the DNA binding activity of NF-kappaB family proteins, suggesting that cellular NO provides another control mechanism for modulating the expression of NF-kappaB-responsive genes.

465 citations


Authors

Showing all 16531 results

NameH-indexPapersCitations
Yi Chen2174342293080
Paul M. Thompson1832271146736
Ian J. Deary1661795114161
Dongyuan Zhao160872106451
Mark J. Smyth15371388783
Harry Campbell150897115457
William J. Sutherland14896694423
Thomas J. Smith1401775113919
John A. Peacock140565125416
Jean-Marie Tarascon136853137673
David A. Jackson136109568352
Ian Ford13467885769
Timothy J. Mitchison13340466418
Will J. Percival12947387752
David P. Lane12956890787
Network Information
Related Institutions (5)
University of Oxford
258.1K papers, 12.9M citations

94% related

University of Cambridge
282.2K papers, 14.4M citations

94% related

University of Edinburgh
151.6K papers, 6.6M citations

93% related

University of Manchester
168K papers, 6.4M citations

93% related

University College London
210.6K papers, 9.8M citations

93% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023127
2022387
20211,998
20201,996
20192,059
20181,946