Impact of cardiac arrest centers on the survival of patients with nontraumatic out‐of‐hospital cardiac arrest : a systematic review and meta‐analysis

Background The role of cardiac arrest centers (CACs) in out‐of‐hospital cardiac arrest care systems is continuously evolving. Interpretation of existing literature is limited by heterogeneity in CAC characteristics and types of patients transported to CACs. This study assesses the impact of CACs on survival in out‐of‐hospital cardiac arrest according to varying definitions of CAC and prespecified subgroups. Methods and Results Electronic databases were searched from inception to March 9, 2021 for relevant studies. Centers were considered CACs if self‐declared by study authors and capable of relevant interventions. Main outcomes were survival and neurologically favorable survival at hospital discharge or 30 days. Meta‐analyses were performed for adjusted odds ratio (aOR) and crude odds ratios. Thirty‐six studies were analyzed. Survival with favorable neurological outcome significantly improved with treatment at CACs (aOR, 1.85 [95% CI, 1.52–2.26]), even when including high‐volume centers (aOR, 1.50 [95% CI, 1.18–1.91]) or including improved‐care centers (aOR, 2.13 [95% CI, 1.75–2.59]) as CACs. Survival significantly increased with treatment at CACs (aOR, 1.92 [95% CI, 1.59–2.32]), even when including high‐volume centers (aOR, 1.74 [95% CI, 1.38–2.18]) or when including improved‐care centers (aOR, 1.97 [95% CI, 1.71–2.26]) as CACs. The treatment effect was more pronounced among patients with shockable rhythm ( P =0.006) and without prehospital return of spontaneous circulation ( P =0.005). Conclusions were robust to sensitivity analyses, with no publication bias detected. Conclusions Care at CACs was associated with improved survival and neurological outcomes for patients with nontraumatic out‐of‐hospital cardiac arrest regardless of varying CAC definitions. Patients with shockable rhythms and those without prehospital return of spontaneous circulation benefited more from CACs. Evidence for bypassing hospitals or interhospital transfer remains inconclusive

Celestial holography and AdS 3/CFT 2 from a scaling reduction of twistor space

Abstract Celestial amplitudes obtained from Mellin transforming 4d momentum space scattering amplitudes contain distributional delta functions, hindering the application of conventional CFT techniques. In this paper, we propose to bypass this problem by recognizing Mellin transforms as integral transforms projectivizing certain components of the angular momentum. It turns out that the Mellin transformed wavefunctions in the conformal primary basis can be regarded as representatives of certain cohomology classes on the minitwistor space of the hyperbolic slices of 4d Minkowski space. Geometrically, this amounts to treating 4d Minkowski space as the embedding space of AdS 3. By considering scattering of such on-shell wavefunctions on the projective spinor bundle ℙ of Euclidean AdS 3, we bypass the difficulty of the distributional properties of celestial correlators using the traditional AdS 3 /CFT 2 dictionary and find conventional 2d CFT correlators for the scaling reduced Yang-Mills theory living on the hyperbolic slices. In the meantime, however, one is required to consider action functionals on the auxiliary space ℙ, which introduces additional difficulties. Here we provide a framework to work on the projective spinor bundle of hyperbolic slices, obtained from a careful scaling reduction of the twistor space of 4d Minkowski spacetime

Celestial holography and AdS 3 / CFT 2 from a scaling reduction of twistor space

Acknowledgements: It is a pleasure to thank Tim Adamo and David Skinner for discussions. We also thank Tim Adamo, Simon Heuveline and David Skinner for commenting on earlier versions of the draft. A large amount of the twistor theory (including all sections without citations to extant work) is due to many productive discussions and original work by SS with Yvonne Geyer, Lionel Mason and especially David Skinner about the corresponding story in AdS5, minimally adapted to the AdS3 case. WB is supported by the Royal Society Studentship. SS is supported by the Trinity College Internal Graduate Studentship. The work of SS has been supported in part by STFC consolidated grants ST/T000694/1 and ST/X000664/1.Celestial amplitudes obtained from Mellin transforming 4d momentum space scattering amplitudes contain distributional delta functions, hindering the application of conventional CFT techniques. In this paper, we propose to bypass this problem by recognizing Mellin transforms as integral transforms projectivizing certain components of the angular momentum. It turns out that the Mellin transformed wavefunctions in the conformal primary basis can be regarded as representatives of certain cohomology classes on the minitwistor space of the hyperbolic slices of 4d Minkowski space. Geometrically, this amounts to treating 4d Minkowski space as the embedding space of AdS3. By considering scattering of such on-shell wavefunctions on the projective spinor bundle ℙ of Euclidean AdS3, we bypass the difficulty of the distributional properties of celestial correlators using the traditional AdS3/CFT2 dictionary and find conventional 2d CFT correlators for the scaling reduced Yang-Mills theory living on the hyperbolic slices. In the meantime, however, one is required to consider action functionals on the auxiliary space ℙ, which introduces additional difficulties. Here we provide a framework to work on the projective spinor bundle of hyperbolic slices, obtained from a careful scaling reduction of the twistor space of 4d Minkowski spacetime

Celestial holography and AdS3/CFT2 from a scaling reduction of twistor space

Acknowledgements: It is a pleasure to thank Tim Adamo and David Skinner for discussions. We also thank Tim Adamo, Simon Heuveline and David Skinner for commenting on earlier versions of the draft. A large amount of the twistor theory (including all sections without citations to extant work) is due to many productive discussions and original work by SS with Yvonne Geyer, Lionel Mason and especially David Skinner about the corresponding story in AdS5, minimally adapted to the AdS3 case. WB is supported by the Royal Society Studentship. SS is supported by the Trinity College Internal Graduate Studentship. The work of SS has been supported in part by STFC consolidated grants ST/T000694/1 and ST/X000664/1.Abstract Celestial amplitudes obtained from Mellin transforming 4d momentum space scattering amplitudes contain distributional delta functions, hindering the application of conventional CFT techniques. In this paper, we propose to bypass this problem by recognizing Mellin transforms as integral transforms projectivizing certain components of the angular momentum. It turns out that the Mellin transformed wavefunctions in the conformal primary basis can be regarded as representatives of certain cohomology classes on the minitwistor space of the hyperbolic slices of 4d Minkowski space. Geometrically, this amounts to treating 4d Minkowski space as the embedding space of AdS3. By considering scattering of such on-shell wavefunctions on the projective spinor bundle ℙ of Euclidean AdS3, we bypass the difficulty of the distributional properties of celestial correlators using the traditional AdS3/CFT2 dictionary and find conventional 2d CFT correlators for the scaling reduced Yang-Mills theory living on the hyperbolic slices. In the meantime, however, one is required to consider action functionals on the auxiliary space ℙ, which introduces additional difficulties. Here we provide a framework to work on the projective spinor bundle of hyperbolic slices, obtained from a careful scaling reduction of the twistor space of 4d Minkowski spacetime.</jats:p

Spectral flow and localisation in AdS3 string theory

Acknowledgements: We thank Andrea Dei, Yasuaki Hikida, Matthias Gaberdiel, Sylvain Lacriox, Nathan McStay, Kiarash Naderi, Beat Nairz, Ron Reid-Edwards, Volker Schomerus, and David Skinner for useful discussions. We also thank Andrea Dei, Lorenz Eberhardt, Matthias Gaberdiel, Ron Reid-Edwards and David Skinner for useful comments on an early version of the draft. We further thank Yasuaki Hikida and Volker Schomerus for sharing a preliminary version of their recent paper [32]. The work of VS is supported by a grant from the Swiss National Science Foundation. VS also acknowledges the support by the NCCR SwissMAP that is also supported by the Swiss National Science Foundation. The work of BK and SS is supported by STFC consolidated grants ST/T000694/1 and ST/X000664/1. The work of SS is also supported by the Trinity Internal Graduate studentship.Abstract We study string theory in three-dimensional Anti-de Sitter spacetime in the path integral formalism. We derive expressions for generic spectrally-flowed near-boundary vertex operators in the Wakimoto representation, and relate their correlation functions to covering maps from the worldsheet to the target space boundary. We show that the path integral structurally reproduces correlation functions of the dual symmetric orbifold theory. By rephrasing spectral flow as the introduction of a background gauge field, we provide a path integral derivation of the localisation property of the near boundary theory. We then focus on the case of IIB string theory on AdS3 × S3 × 4 with k = 1 units of NS-NS flux, where the relationship between correlation functions and covering maps can be made sharp. We also comment on the relation of the k = 1 theory and twistor theory.</jats:p

The “brick by brick” campaign.

This paper presents the “Brick by Brick” campaign, a youth-led initiative by four final year students from the Wee Kim Wee School of Communication and Information, Nanyang Technological University. Targeted at primarily youth and young adults aged 18-35, the public communication campaign aims to promote awareness about troubled and at-risk youth in Singapore, as well as the various organisations that have been set up to provide assistance and guidance to this group of youth, with particular focus on the efforts of Boys’ Town Singapore. The campaign also looks to contribute toward Boys’ Town’s fundraising efforts, mainly through the sale of locally designed merchandise, as they are undergoing a much-needed and financially intensive overhaul of their premises. The key strategies and communication channels that were put in place are documented in this following report. These measures helped to create a cohesive and successful campaign, which was able to meet its objectives. This paper provides conclusive research that helped to mould the direction of the campaign, strategies planned, execution of the strategies, as well as an evaluation of the campaign. The sustainability of the campaign will be highlighted, and the report will be concluded with recommendations on how the future implications of the campaign and how it can be further developed.Bachelor of Communication Studie