Shrinkage Estimation in Multilevel Normal Models

This review traces the evolution of theory that started when Charles Stein in 1955 [In Proc. 3rd Berkeley Sympos. Math. Statist. Probab. I (1956) 197--206, Univ. California Press] showed that using each separate sample mean from $k\ge3$ Normal populations to estimate its own population mean $\mu_i$ can be improved upon uniformly for every possible $\mu=(\mu_1,...,\mu_k)'$. The dominating estimators, referred to here as being "Model-I minimax," can be found by shrinking the sample means toward any constant vector. Admissible minimax shrinkage estimators were derived by Stein and others as posterior means based on a random effects model, "Model-II" here, wherein the $\mu_i$ values have their own distributions. Section 2 centers on Figure 2, which organizes a wide class of priors on the unknown Level-II hyperparameters that have been proved to yield admissible Model-I minimax shrinkage estimators in the "equal variance case." Putting a flat prior on the Level-II variance is unique in this class for its scale-invariance and for its conjugacy, and it induces Stein's harmonic prior (SHP) on $\mu_i$.Comment: Published in at http://dx.doi.org/10.1214/11-STS363 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Developing and modelling complex social interventions: introducing the Connecting People Intervention

Objectives: Modeling the processes involved in complex social interventions is important in social work practice, as it facilitates their implementation and translation into different contexts. This article reports the process of developing and modeling the connecting people intervention (CPI), a model of practice that supports people with mental health problems to enhance their social networks. Method: The CPI model was developed through an iterative process of focus group discussions with practitioners and service users and a two-stage Delphi consultation with relevant experts. Results: We discuss the intervention model and the processes it articulates to provide an example of the benefits of intervention modeling. Conclusions: Intervention modeling provides a visual representation of the process and outcomes of an intervention, which can assist practice development and lead to improved outcomes for service users

Novel approaches to the synthesis of aromatic compounds

Imperial Users onl

Cross-sectional Analysis of Sound Levels in the Neonatal Intensive Care Unit (NICU) at Thomas Jefferson University Hospital

Introduction . Infants in the NICU are considered at greater risk of developmental delay. It is now known that excessively loud noise can have a negative impact on parameters such as blood pressure, breathing, heart beat and oxygen saturation. Previous research has concluded that the optimal decibel (dB) level for proper growth of neonate hair cells rests around 45dB. Consequently, the American Academy of Pediatrics recommends that noise levels in the NICU be maintained to a maximum of 45dBA. However, little research has focused on designing new noise-altering products and their impact on neonatal outcomes. Methods. This was a cross sectional study. The NICU at Thomas Jefferson University Hospital was observed for room arrangements and general workflow. Additionally, decibel levels around empty neonatal incubators were measured. A decibel analyzer (REED Instruments SD-4023, Wilmington, NC) was used to record sound levels, both inside and outside of isolettes during various routine activities, including patient rounds, provider-parent conversations and vital monitoring alarms. Results. 30 discrete data points were surveyed, in addition to a 24-hour continuous decibel recording. Across all discrete data points, decibel levels had a mean of 65.6dB (SD ± 10.3). Ambient noise alone in a patient room was measured at 50dB. Noise levels in an open and closed isolette were measured at 58 and 57dB, respectively. Isolette side door opening and closing had a mean of 80.2dB (SD ± 7.60). With medical devices active in the patient room, noise levels had a mean of 62.7dB (SD ± 7.74). Conclusions. All data points were above the recommended safe noise level of 45dB. This data supports our development of a noise reduction product for use within neonatal isolettes. Our design will incorporate sterilizable, sound-absorbent materials and diffusion technologies to decrease ambient noise within neonatal incubators

An Exact Renormalization Group analysis of 3-d Well Developed turbulence

We take advantage of peculiar properties of three dimensional incompressible turbulence to introduce a nonstandard Exact Renormalization Group method. A Galilean invariance preserving regularizing procedure is utilized and a field truncation is adopted to test the method. Results are encouraging: the energy spectrum E(k) in the inertial range scales with exponent -1.666+/- 0.001 and the Kolmogorov constant C_K, computed for several (realistic) shapes of the stirring force correlator, agrees with experimental data.Comment: 12 pg, 2figures, LaTex, To be published on Physics Letters

The Near-Infrared Broad Emission Line Region of Active Galactic Nuclei -- I. The Observations

We present high quality (high signal-to-noise ratio and moderate spectral resolution) near-infrared (near-IR) spectroscopic observations of 23 well-known broad-emission line active galactic nuclei (AGN). Additionally, we obtained simultaneous (within two months) optical spectroscopy of similar quality. The near-IR broad emission line spectrum of AGN is dominated by permitted transitions of hydrogen, helium, oxygen, and calcium, and by the rich spectrum of singly-ionized iron. In this paper we present the spectra, line identifications and measurements, and address briefly some of the important issues regarding the physics of AGN broad emission line regions. In particular, we investigate the excitation mechanism of neutral oxygen and confront for the first time theoretical predictions of the near-IR iron emission spectrum with observations.Comment: 45 pages, 17 figures, accepted by ApJ

THE ROLE OF CAUSAL PERCEPTION OF MOVEMENT IN THE EARLY SOCIAL DEVELOPMENT OF AUTISTIC CHILDREN

Autistic children often lack social behaviours which are normally present by 8-12 months (Klin et al, 1992; Mundy et al, 1986), although current 'top down' theories about autism hypothesise later-developing conceptual difficulties in social cognition. Research indicates that there are abnormal 'bottom up' perceptual processes in autism (Moore, Hobson & Lee, 1995). Processing of unexpected dynamic visual information may occur to a diminished extent (Courchesne, 1987), whilst in normal infancy, causal perception of the movements of animate. and inanimate objects is likely to be important for social cognition and affective relationships (Shultz, 1989; Premack & Dasser, 1990). It has been suggested that autistic children have difficulties with the unpredictable nature of perceived social information (Moody & Sigman, 1989b; Dawson & Lewy, 1989). On the basis of such previous research, it was proposed that the early social abnormalities of autistic children are a result -of them tending not to notice, or process further, brief dynamic visual information about events unless these follow simple predictable patterns. To test this hypothesis, seven young autistic and seven developmentally delayed children, matched pairwise for verbal comprehension, were initially habituated to two computer-generated displays, of a cartoon-like 'boy' (Runner) running up to a 'wall' and back, and of a 'ball' moving towards the wall and apparently re-bounding back. Visual habituation was reliable and due to information encoding. The autistic children looked relatively less at the Runner habituation display, perhaps due to relatively diminished processing of animate dynamic information. After habituation criterion was reached, a time delay was introduced prolonging contact with the wall, so that the Ball display became 'impossible' whereas the Runner remained 'possible'. As predicted, recovery of visual fixation indicated that the delay was discriminated, and the autistic children recovered relatively less to the novel Ball display compared with the developmentally delayed children. The autistic children may not have perceived the anomaly in the novel 'impossible' Ball event. They either may have had a general expectation for inanimate objects to move independently, or a tendency not to notice altered significance in a repetitive visual event. However, the group differences could also have been due to the autistic children tending not to have real life expectations of cartoon images. Consistent with the hypothesis, the scores of all 14 children both for pre-11 month social behaviours and for joint attention, were associated with relative recovery for the novel Ball display. As predicted from previous research, the autistic children engaged infrequently in these social behaviours. It is proposed that how children perceive the dynamic animate and inanimate world affects how they develop socially during their first year of life. Relevant areas for future research and implications for early interventions are discussed.Child Development Centre, Plymouth Hospitals NHS Trust, Downham School, Mill Ford School & South Trelawney Primary School, Plymout

The Rent-Price Ratio for the Aggregate Stock of Owner-Occupied Housing

We construct a time series of the rent-price ratio for the owner- occupied stock of housing, starting in 1960:1, by merging micro data from the last five Decennial Censuses of Housing with price indexes for house prices and rents.House Prices, Housing, Rents, CMHPI, Capitalization Rates