Mentoring to reduce antisocial behaviour in childhood

The effects of social interventions need to be examined in real life situations as well as studie

Defining the substrate for ventricular tachycardia ablation: The impact of rhythm at the time of mapping

BACKGROUND: Voltage mapping is critical to define substrate during ablation. In ventricular tachycardia, abnormal potentials may be targets. However, wavefront of activation could impact local signal characteristics. This may be particularly true when comparing sinus rhythm versus paced rhythms. We sought to determine how activation wavefront impacts electrogram characteristics. METHODS: Patients with ischemic cardiomyopathy, ventricular tachycardia, and without fascicular or bundle branch block were included. Point by point mapping was done and at each point, one was obtained during an atrial paced rhythm and one during a right ventricular paced rhythm. Signals were adjudicated after ablation to define late potentials, fractionated potentials, and quantify local voltage. Areas of abnormal voltage (defined as \u3c1.5 mV) were also determined. RESULTS: 9 patients were included (age 61.3 ± 9.2 years, 56% male, mean LVEF 34.9 ± 8.6%). LV endocardium was mapped with an average 375 ± 53 points/rhythm. Late potentials were more frequent during right ventricular pacing (51 ± 21 versus 32 ± 15, p \u3c 0.01) while overall scar area was higher during atrial pacing (22 ± 11% vs 13 ± 7%, p \u3c 0.05). In 1/9 patients, abnormal potentials were seen during a right ventricular paced rhythm that were not apparent in an atrial paced rhythm, ablation of which resulted in non-inducibility. CONCLUSION: Rhythm in which mapping is performed has an impact on electrogram characteristics. Whether one rhythm is preferable to map in remains to be determined. However, it is possible defining local signals during normal conduction as well as variable paced rhythms may impart a greater likelihood of elucidating arrhythmogenic substrate

Environmental management decision-making in certified hotels

This paper analyses environmental decision-making against two axes, motivations and decision-making processes, to understand the reasons for pro-environmental behaviour by the managements of Spanish Eco-management and Audit Scheme (EMAS)-certified hotels. Mixed methods were used to study perceptions of EMAS and reasons for being certified, with current and lapsed EMAS-certified firms triangulated against expert interviews and documentary evidence. Four groups of hotels were differentiated: Strategic hotels (22%) (with high levels of integrated environmental management), Followers (48%), Greenwashers (11%) and Laggers (19%) (with low levels of integrated environmental management). Most hotels were found to be internally driven in their purpose and ad hoc in their decision-making, with limited understanding of externally driven benefits and motivation for more systematic management systems. This questions the success of EMAS as both a continuous improvement management and as a market-based regulation tool for hotels. Few hotels overall related high environmental standards to the possibilities of gaining market advantage: most wished to avoid legal challenges. The paper also illustrates the ways in which hotels opportunistically switch certification systems to get what they see as a better deal. © 2011 Taylor & Francis

Halo mass - concentration relation from weak lensing

We perform a statistical weak lensing analysis of dark matter profiles around tracers of halo mass from galactic- to cluster-size halos. In this analysis we use 170,640 isolated ~L* galaxies split into ellipticals and spirals, 38,236 groups traced by isolated spectroscopic Luminous Red Galaxies (LRGs) and 13,823 MaxBCG clusters from the Sloan Digital Sky Survey (SDSS) covering a wide range of richness. Together these three samples allow a determination of the density profiles of dark matter halos over three orders of magnitude in mass, from 10^{12} M_{sun} to 10^{15} M_{sun}. The resulting lensing signal is consistent with an NFW or Einasto profile on scales outside the central region. We find that the NFW concentration parameter c_{200b} decreases with halo mass, from around 10 for galactic halos to 4 for cluster halos. Assuming its dependence on halo mass in the form of c_{200b} = c_0 [M/(10^{14}M_{sun}/h)]^{\beta}, we find c_0=4.6 +/- 0.7 (at z=0.22) and \beta=0.13 +/- 0.07, with very similar results for the Einasto profile. The slope (\beta) is in agreement with theoretical predictions, while the amplitude is about two standard deviations below the predictions for this mass and redshift, but we note that the published values in the literature differ at a level of 10-20% and that for a proper comparison our analysis should be repeated in simulations. We discuss the implications of our results for the baryonic effects on the shear power spectrum: since these are expected to increase the halo concentration, the fact that we see no evidence of high concentrations on scales above 20% of the virial radius suggests that baryonic effects are limited to small scales, and are not a significant source of uncertainty for the current weak lensing measurements of the dark matter power spectrum. [ABRIDGED]Comment: 17 pages, 5 figures, accepted to JCAP pending minor revisions that are included in v2 here on arXi

SDSS-RASS: Next Generation of Cluster-Finding Algorithms

We outline here the next generation of cluster-finding algorithms. We show how advances in Computer Science and Statistics have helped develop robust, fast algorithms for finding clusters of galaxies in large multi-dimensional astronomical databases like the Sloan Digital Sky Survey (SDSS). Specifically, this paper presents four new advances: (1) A new semi-parametric algorithm - nicknamed ``C4'' - for jointly finding clusters of galaxies in the SDSS and ROSAT All-Sky Survey databases; (2) The introduction of the False Discovery Rate into Astronomy; (3) The role of kernel shape in optimizing cluster detection; (4) A new determination of the X-ray Cluster Luminosity Function which has bearing on the existence of a ``deficit'' of high redshift, high luminosity clusters. This research is part of our ``Computational AstroStatistics'' collaboration (see Nichol et al. 2000) and the algorithms and techniques discussed herein will form part of the ``Virtual Observatory'' analysis toolkit.Comment: To appear in Proceedings of MPA/MPE/ESO Conference "Mining the Sky", July 31 - August 4, 2000, Garching, German

Discontinuous Molecular Dynamics for Semi-Flexible and Rigid Bodies

A general framework for performing event-driven simulations of systems with semi-flexible or rigid bodies interacting under impulsive torques and forces is outlined. Two different approaches are presented. In the first, the dynamics and interaction rules are derived from Lagrangian mechanics in the presence of constraints. This approach is most suitable when the body is composed of relatively few point masses or is semi-flexible. In the second method, the equations of rigid bodies are used to derive explicit analytical expressions for the free evolution of arbitrary rigid molecules and to construct a simple scheme for computing interaction rules. Efficient algorithms for the search for the times of interaction events are designed in this context, and the handling of missed interaction events is discussed.Comment: 16 pages, double column revte

Mass, Light and Colour of the Cosmic Web in the Supercluster SCL2243-0935 (z=0.447)

Context: In 2.2m MPG-ESO/WFI data we discovered several mass peaks through weak lensing, forming a possible supercluster at redshift 0.45. Through multi-colour wide-field imaging with CFHT/Megaprime and INT/WFC we identify early-type galaxies and trace the supercluster network with them. Through EMMI/NTT multi-object spectroscopy we verify the initial shear-selected cluster candidates. Using weak lensing we obtain mass estimates for the supercluster centre and the filaments. Results: We identified the centre of the SCL2243-0935 supercluster, MACS J2243-0935, which was found independently by Ebeling et al. (2010). 13 more clusters or overdensities are embedded in a filamentary network, half of them are already spectroscopically confirmed. Three (5-15) Mpc filaments are detected, and we estimate the global size of SCL2243 to 45x15x50 Mpc, making it one of the largest superclusters known at intermediate redshifts. Weak lensing yields r_200=(2.06+/-0.13) Mpc and M_200=(1.54+/-0.29)x10^15 M_sun for MACS J2243 with M/L=428+/-82, very similar to results from size-richness cluster scaling relations. Integrating the weak lensing surface mass density over the supercluster network (defined by increased i-band luminosity or g-i colours), we find (1.53+/-1.01)x10^15 M_sun and M/L=305+/-201 for the three main filaments, consistant with theoretical predictions. The filaments' projected surface mass density is 0.007-0.012, corresponding to 10-100 times the critical density. The greatly varying density of the cosmic web is also reflected in the mean colour of galaxies. Conclusions: SCL2243 is significantly larger and much more richly structured than other known superclusters such as A901/902 or MS0302 studied with weak lensing before. It is a text-book supercluster with little contamination along the line of sight, making it a perfect sandbox for testing new techniques probing the cosmic web.Comment: 26 pages, 16 figures, accepted for publication Astronomy and Astrophysics. Minor corrections implemented as requested by the refere

Development of theoretically informed audit and feedback: An exemplar from a complex implementation strategy to improve asthma self-management in UK primary care

RATIONALE: Audit and feedback is an evidence-based implementation strategy, but studies reporting the use of theory to guide design elements are limited. AIMS AND OBJECTIVES: Within the context of a programme of research aiming to improve the implementation of supported asthma self-management in UK primary care (IMPlementing IMProved Asthma self-management as RouTine [IMP2ART]), we aimed to design and develop theoretically-informed audit and feedback that highlighted supported asthma self-management provision and areas for improvement in primary care general practices. METHOD: Aligned with the Medical Research Council (MRC) complex intervention framework, the audit and feedback was developed in three phases: (1) Development: literature and theory exploration, and prototype audit and feedback design; (2) Feasibility: eliciting feedback on the audit and feedback from general practice staff (n = 9); (3) Prepiloting: delivering the audit and feedback within the IMP2ART implementation strategy (incorporating patient and professional resources and an asthma review template) and eliciting clinician feedback (n = 9). RESULTS: Audit and feedback design was guided by and mapped to existing literature suggestions and theory (e.g., Theoretical Domains Framework, Behaviour Change Technique Taxonomy). Feedback on the prototype audit and feedback confirmed feasibility but identified some refinements (a need to highlight supporting self-management and importance of asthma action plans). Prepiloting informed integration with other IMP2ART programme strategies (e.g., patient resources and professional education). CONCLUSION: We conclude that a multistage development process including theory exploration and mapping, contributed to the design and delivery of the audit and feedback. Aligned with the MRC framework, the IMP2ART strategy (incorporating the audit and feedback) is now being tested in a UK-wide cluster randomised controlled trial

Prevalence estimates of trafficking in persons using statistical definitions: A cross-sectional high-risk community survey in Cape Town, South Africa

OBJECTIVES: Current research on trafficking in persons (TIP) relies heavily on legal and prosecutorial definitions. A public health approach has called for population-level assessment; however, identification of TIP victims lacks a standardised operational definition. This study applied the Prevalence Reduction Innovation Forum (PRIF) statistical definitions, developed by the US Department of State, to a community survey in Cape Town, South Africa. DESIGNS: A high-risk sampling strategy was used. TIP screening questions from two instruments were matched with PRIF domain indicators to generate prevalence estimates. Sensitivity, specificity and receiver operating characteristics analyses were conducted to assess the performance of the two screeners. SETTING: Cross-sectional survey conducted in Cape Town, South Africa, from January to October 2021. PARTICIPANTS: South Africans and immigrants from other nations residing in Cape Town and its surrounding areas, aged 18 or older, who met the study inclusion criteria for a set of experiences that were identified as TIP risk factors. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome measures were PRIF lifetime and past 12-month TIP positivity. Secondary outcome measures included individual and summary measures from the two screeners. RESULTS: Our PRIF algorithm yielded a TIP lifetime prevalence rate of 17.0% and past 12-month rate of 2.9%. Summary measures from each TIP screener showed an excellent range of predictive utility. The summary screener measures yielded statistically significant differences among some demographic and background categories. Several screener items were shown less predictive of the PRIF statistical definition criteria than others. CONCLUSIONS: Prevalence estimates of probable TIP were higher than those reported elsewhere. Our TIP screeners yielded an excellent range of predictive utility for the statistical definitions, promising the potential for wider applications in global and regional TIP research and policymaking. A more systematic sampling strategy is needed even if statistical definitions become widely used