Missing out or singling out? Parents’ views on how health professionals should work with them now to get the best for their child in the future

Aim To investigate parents’ views about how health professionals should identify and work with families who may benefit from additional input to maximise their children’s future health and well-being. Methods A qualitative study was conducted. Eleven focus group interviews were carried out with 54 parents living in the north of England. Comparative analysis was carried out to highlight similarities and differences across key concepts. Results The idea of preventive services was welcomed by all parents. They strongly believed that everyone should have access to services aiming to enhance child well-being. Parents recognised that some families need additional support but were concerned that targeted services could result in missing out on some services. They were also concerned that if certain services were offered because they belonged to a group with an increased likelihood of poor child outcomes this could lead to feelings of being assessed, stereotyped and judged and that their abilities as parents were being questioned. Parents projected a belief in themselves as ‘good parents’ even in adverse circumstances. Targeted services could be acceptable if health professionals introduced them sensitively, for example, encouraging attendance at groups to provide support was considered to be helpful. Conclusions Targeted additional preventive services can be acceptable and welcome if health professionals introduce them sensitively, in the context of an existing relationship, providing parents are active participants

Investigation of the Orthogonal Blade-Vortex Interaction 1st Interim Report. G.U. Aero Report 0210

Steps towards the implementation of a stereoscopic particle image velocimetry (PIV) system for the investigation of the orthogonal blade-vortex interaction are described. The design of the stereo PIV system used is described, and details of the Scheimpflug camera mounts are provided. The necessary changes to the image capture and calibration procedures are described, and brief details of the stereo PIV analysis are given. This is essential preparatory work for the experimental study of the orthogonal blade-vortex interaction using stereoscopic PIV to take place later in this project

Investigation of the Orthogonal Blade-Vortex Interaction 2nd Interim Report. G.U. Aero Report 0103

Preliminary results from a PIV study of the orthogonal blade-vortex interaction are presented. This report presents a comparison of the details of the orthogonal BVI over the lower and upper surfaces of the blade. Detailed differences in the mechanics of these interactions have been noted. Features of the vortex behaviour in the wake of the blade are also presented together with the results obtained at very close proximity to the blade surface

Investigation of the Orthogonal Blade-Vortex Interaction 2nd Interim Report. G.U. Aero Report 0303

Steps towards the implementation of a stereoscopic particle image velocimetry (PIV) system for the investigation of the orthogonal blade-vortex interaction are described. The accuracy of the 2D PIV system has been reassessed in the light of the greater accuracy demands of stereo PIV. The improvement to the perceived quality of the PIV vector map from a discrete window offset algorithm was investigated, and it was observed that significant improvements were made in the critical vortex core region

Investigation of the Orthogonal Blade-Vortex Interaction 1st Interim Report. G.U. Aero Report 0012

Preliminary results from a PIV study of the orthogonal blade-vortex interaction are presented. The tests have focussed upon phenomena occurring over the lower and upper surfaces of the blade. An analysis of the BVI over the upper surface has revealed an inflow to the vortex core, which contrasts with the radial outflow previously observed over the lower surface

Investigation of the Orthogonal Blade-Vortex Interaction 1st Interim Report. G.U. Aero Report 0210

Steps towards the implementation of a stereoscopic particle image velocimetry (PIV) system for the investigation of the orthogonal blade-vortex interaction are described. The design of the stereo PIV system used is described, and details of the Scheimpflug camera mounts are provided. The necessary changes to the image capture and calibration procedures are described, and brief details of the stereo PIV analysis are given. This is essential preparatory work for the experimental study of the orthogonal blade-vortex interaction using stereoscopic PIV to take place later in this project

A geometric construction of the exceptional Lie algebras F4 and E8

We present a geometric construction of the exceptional Lie algebras F4 and E8 starting from the round 8- and 15-spheres, respectively, inspired by the construction of the Killing superalgebra of a supersymmetric supergravity background. (There is no supergravity in the paper.)Comment: 12 page

The Littlewood-Gowers problem

We show that if A is a subset of Z/pZ (p a prime) of density bounded away from 0 and 1 then the A(Z/pZ)-norm (that is the l^1-norm of the Fourier transform) of the characterstic function of A is bounded below by an absolute constant times (log p)^{1/2 - \epsilon} as p tends to infinity. This improves on the exponent 1/3 in recent work of Green and Konyagin.Comment: 31 pp. Corrected typos. Updated references

Planar diagrams in light-cone gauge

We consider the open string vacuum amplitude determining the interaction between a stack of N D3-branes and a single probe brane. When using light cone gauge, it is clear that the sum of planar diagrams (relevant in the large-N limit) is described by the free propagation of a closed string. A naive calculation suggests that the Hamiltonian of the closed string is of the form H = H0 - (g_s N) P. The same form of the Hamiltonian follows from considering the bosonic part of the closed string action propagating in the full D3-brane background suggesting the naive calculation captures the correct information. Further, we compute explicitly P from the open string side in the bosonic sector and show that, in a certain limit, the result agrees with the closed string expectations up to extra terms due to the fact that we ignored the fermionic sector. We briefly discuss extensions of the results to the superstring and to the sum of planar diagrams in field theory. In particular we argue that the calculations seem valid whenever one can define a sigma tau dual Hamiltonian in the world-sheet which in principle does not require the existence of a string action. This seems more generic than the existence of a string dual in the large-N limit.Comment: 42 pages, 7 figures, LaTeX. v2: references added. v3: typos and minor corrections. Small change of conventions in fermionic secto

Non-renormalization conditions for four-gluon scattering in supersymmetric string and field theory

The constraints imposed by maximal supersymmetry on multi-loop contributions to the scattering of four open superstrings in the U(N) theory are examined by use of the pure spinor formalism. The double-trace term k^2 t_8(tr F^2)^2 (where k represents an external momentum and F the Yang--Mills field strength) only receives contributions from L<=2 (where L is the loop number) while the single-trace term k^2 t_8(tr F^4) receives contributions from all L. We verified these statements up to L=5, but arguments based on supersymmetry suggest they extend to all L. This explains why the single-trace contributions to low energy maximally supersymmetric Yang--Mills field theory are more divergent in the ultraviolet than the double-trace contributions. We also comment further on the constraints on closed string amplitudes and their implications for ultraviolet divergences in N=8 supergravity.Comment: 25 pages. 2 eps figures. Harvmac format. v2 qualifications regarding comments on closed strings. References adde