Time-gated transillumination and reflection by biological tissues and tissuelike phantoms: simulation versus experiment

A numerical method is presented to solve exactly the time-dependent diffusion equation that describes light transport in turbid media. The simulation takes into account spatial variations of the scattering and absorption factors of the medium and the objects as well as random fluctuations of these quantities. The technique is employed to explore the possibility of locating millimeter-sized objects immersed in turbid media from time-gated measurements of the transmitted or reflected (near-infrared) light. The simulation results for tissue-like phantoms are compared with experimental transillumination data, and excellent agreement is found. Simulations of time-gated reflection experiments indicate that it may be possible to detect objects of 1-mm radius.

Evaluating heathland restoration belowground using different quality indices of soil chemical and biological properties

Reversion of agricultural land to heathland and acid grassland is a priority for the conservation of these rare habitats. Restoration processes require interventions to reverse the effects of fertilization and acidity amelioration undertaken during decades of agricultural production. Belowground assessments of restoration success are few, and we have examined the utility of soil indices as a rationalized tool for land managers and restoration practitioners to assess the efficacy of restoration practice. To achieve this, we assessed a large number of variables, many of which might be near redundant, that could be optimized for such indices. We used a 14-year field experiment contrasting acidified pasture (treated with elemental sulphur), control (untreated) pasture, and adjacent native heathland and acid grassland sites. Based on biotic and abiotic parameters, several ‘heathland restoration indices’ (resembling soil quality indices) were generated using a minimum dataset identified through principal component analysis and a linear scoring system. For comparison we also conducted alternative analyses of all parameters, using nonmetric multidimensional scaling plots and analyses of similarity (ANOSIM). Use of heathland restoration indices showed that elemental sulphur application had changed the soil chemical conditions, along with the vegetation assemblage, to be comparable to that of native acid grassland, but not the belowground biology. ANOSIM on full datasets confirmed this finding. An index based on key variables, rather than an analysis of all biotic and abiotic parameters, can be valuable to land managers and stakeholders in acid grassland and heathland restoration

Proposal for generalised Supersymmetry Les Houches Accord for see-saw models and PDG numbering scheme

The SUSY Les Houches Accord (SLHA) 2 extended the first SLHA to include various generalisations of the Minimal Supersymmetric Standard Model (MSSM) as well as its simplest next-to-minimal version. Here, we propose further extensions to it, to include the most general and well-established see-saw descriptions (types I/II/III, inverse, and linear) in both an effective and a simple gauged extension of the MSSM framework. In addition, we generalise the PDG numbering scheme to reflect the properties of the particles.Comment: 44 pages. Changed titl

The U&I study: study protocol for a feasibility randomised controlled trial of a pre-cognitive behavioural therapy digital ‘informed choice’ intervention to improve attitudes towards uptake and implementation of CBT for psychosis

Background: At least 40% of people with psychosis have persistent distressing symptoms despite optimal medication treatment. Cognitive Behaviour Therapy for psychosis (CBTp) is the only NICE recommended individual therapy for psychosis, with effects on symptoms, distress and quality of life. Yet fewer than 20% of service-users receive it and 94% of trusts struggle to provide it. Of those offered it, 22-43% refuse or do not attend. We have developed a new pre-CBTp informed choice intervention to address knowledge and attitudes that influence uptake and implementation and now want to test it in a feasibility trial. Methods: The design is a 2-arm, feasibility RCT, with 1:1 randomisation, stratified by participant group and site. Participants are 40 psychosis patients and 40 clinicians, who are ambivalent towards uptake or implementation of CBTp. Sites are community and inpatient services in Sussex and London. The intervention is a pre-CBT digital psychoeducation intervention designed to address identified knowledge and attitudinal barriers to uptake and implementation of CBTp, incorporating behaviour change mechanisms, and supported by animated introductory, patient and clinician stories. The comparator is the NHS choices website for CBT. The primary aim is to assess clinical feasibility (recruitment, randomization, acceptability, use, delivery, outcome measurement, retention). A secondary aim is a preliminary evaluation of efficacy. Outcomes will be assessed at baseline, post-intervention, and one-month follow up (blind to treatment arm). The primary efficacy outcome is likelihood of offering/taking up CBTp. Secondary outcomes include knowledge and attitudes towards CBTp; illness perceptions; empowerment; psychological wellbeing (patients only); CBTp implementation (clinicians only). Use of the intervention and CBT behaviours during the follow-up period will be recorded, and captured in a feedback questionnaire. Use, acceptability and experience of outcome assessment will be explored in qualitative interviews with participants (n = 6 per group). The efficacy evaluation will report descriptive data, key model parameters and 95% Highest Probability Density intervals in a Bayesian growth model. Discussion: This is the first feasibility trial of a digital ‘informed choice’ decision aid for the implementation of CBTp. If the trial proves feasible and demonstrates preliminary evidence of efficacy, a large multi-site trial will be warranted

Optical counterpart of HLX-1 during the 2010 outburst

We studied the optical counterpart of the intermediate-mass black hole candidate HLX-1 in ESO 243-49. We used a set of Very Large Telescope imaging observations from 2010 November, integrated by Swift X-ray data from the same epoch. We measured standard Vega brightnesses U = 23.89 +/- 0.18 mag, B = 25.19 +/- 0.30 mag, V = 24.79 +/- 0.34 mag and R = 24.71 +/- 0.40 mag. Therefore, the source was ~1 mag fainter in each band than in a set of Hubble Space Telescope images taken a couple of months earlier, when the X-ray flux was a factor of 2 higher. We conclude that during the 2010 September observations, the optical counterpart was dominated by emission from an irradiated disk (which responds to the varying X-ray luminosity), rather than by a star cluster around the black hole (which would not change). We modelled the Comptonized, irradiated X-ray spectrum of the disk, and found that the optical luminosity and colours in the 2010 November data are still consistent with emission from the irradiated disk, with a characteristic outer radius r_{out} ~ 2800 r_{in} ~ 10^{13} cm and a reprocessing fraction ~ 2 x 10^{-3}. The optical colours are also consistent with a stellar population with age <~ 6 Myr (at solar metallicity) and mass ~ 10^4 M_{sun}; this is only an upper limit to the mass, if there is also a significant contribution from an irradiated disk. We strongly rule out the presence of a young super-star-cluster, which would be too bright. An old globular cluster might be associated with HLX-1, as long as its mass <~ 2 x 10^6 M_{sun} for an age of 10 Gyr, but it cannot significantly contribute to the observed very blue and variable optical/UV emission.Comment: Accepted by MNRAS on Nov 28; 11 pages, 1.3 MB. v2: same paper, same price, now 20% more authors

Band termination in the N=Z Odd-Odd Nucleus 46V

High spin states in the odd-odd N=Z nucleus 46V have been identified. At low spin, the T=1 isobaric analogue states of 46Ti are established up to I = 6+. Other high spin states, including the band terminating state, are tentatively assigned to the same T=1 band. The T=0 band built on the low-lying 3+ isomer is observed up to the 1f7/2-shell termination at I=15. Both signatures of a negative parity T=0 band are observed up to the terminating states at I = 16- and I = 17-, respectively. The structure of this band is interpreted as a particle-hole excitation from the 1d3/2 shell. Spherical shell model calculations are found to be in excellent agreement with the experimental results.Comment: 5 pages, 4 figure

Monitoring and measuring teaching excellence in higher education: from contrived competition to collective collaboration’

This chapter starts by interrogating the notion of teaching excellence. It then moves on to discussing some of the data sources currently used in Higher Education Institutions (HEIs) to monitor and measure the quality of teaching. What do these sources actually reveal about teaching excellence and how might we make better use of them? From large-scale national censuses like the National Student Survey (NSS) to institutional data sets such as teaching observations, the contribution that each source makes to our understanding of the quality of HE teaching is underexplored and contested. It is argued that there is a need for more transparent debate across HEIs and the sector as a whole about the benefits and limitations of such data as well as greater acknowledgement of the role of collaboration over competition. The chapter concludes that teaching excellence is a marketised misconception of the complex reality of the reciprocal relationship between teaching and learning. Contrary to policy rhetoric and far from encouraging an environment of collegial improvement, it introduces an unhelpful ethos of contrived competition into what is essentially an interdependent relationship underpinned by collective collaboration. It is by focusing attention on the latter where the real gains and insights are likely to be made

Experimental evidence for 56Ni-core breaking from the low-spin structure of the N=Z nucleus 58Cu

Low-spin states in the odd-odd N=Z nucleus 58Cu were investigated with the 58Ni(p,n gamma)58Cu fusion evaporation reaction at the FN-tandem accelerator in Cologne. Seventeen low spin states below 3.6 MeV and 17 new transitions were observed. Ten multipole mixing ratios and 17 gamma-branching ratios were determined for the first time. New detailed spectroscopic information on the 2+,2 state, the Isobaric Analogue State (IAS) of the 2+,1,T=1 state of 58Ni, makes 58Cu the heaviest odd-odd N=Z nucleus with known B(E2;2+,T=1 --> 0+,T=1) value. The 4^+ state at 2.751 MeV, observed here for the first time, is identified as the IAS of the 4+,1,T=1 state in 58Ni. The new data are compared to full pf-shell model calculations with the novel GXPF1 residual interaction and to calculations within a pf5/2 configurational space with a residual surface delta interaction. The role of the 56Ni core excitations for the low-spin structure in 58Cu is discussed.Comment: 15 pages, 7 figures, submitted to Phys. Rev.

Menus for Feeding Black Holes

Black holes are the ultimate prisons of the Universe, regions of spacetime where the enormous gravity prohibits matter or even light to escape to infinity. Yet, matter falling toward the black holes may shine spectacularly, generating the strongest source of radiation. These sources provide us with astrophysical laboratories of extreme physical conditions that cannot be realized on Earth. This chapter offers a review of the basic menus for feeding matter onto black holes and discusses their observational implications.Comment: 27 pages. Accepted for publication in Space Science Reviews. Also to appear in hard cover in the Space Sciences Series of ISSI "The Physics of Accretion onto Black Holes" (Springer Publisher