Simulated VLBI Images From Relativistic Hydrodynamic Jet Models

A series of simulated maps showing the appearance in total intensity of flows computed using a recently developed relativistic hydrodynamic code (Duncan \& Hughes 1994: ApJ, 436, L119) are presented. The radiation transfer calculations were performed by assuming the flow is permeated by a magnetic field and fast particle distribution in energy equipartition, with energy density proportional to the hydrodynamic energy density (i.e., pressure). We find that relativistic flows subject to strong perturbations exhibit a density structure consisting of a series of nested bow shocks, and that this structure is evident in the intensity maps for large viewing angles. However, for viewing angles $<30^{\circ}$, differential Doppler boosting leads to a series of axial knots of emission, similar to the pattern exhibited by many VLBI sources. The appearance of VLBI knots is determined primarily by the Doppler boosting of parts of a more extended flow. To study the evolution of a perturbed jet, a time series of maps was produced and an integrated flux light curve created. The light curve shows features characteristic of a radio loud AGN: small amplitude variations and a large outburst. We find that in the absence of perturbations, jets with a modest Lorentz factor ($\sim 5$) exhibit complex intensity maps, while faster jets (Lorentz factor $\sim 10$) are largely featureless. We also study the appearance of kiloparsec jet-counterjet pairs by producing simulated maps at relatively large viewing angles; we conclude that observed hot spot emission is more likely to be associated with the Mach disk than with the outer, bow shock.Comment: 27 pages, uses aasms4.sty; 18 PostScript figures (1.57Mb gziped, 8.67Mb gunziped) available from http://www.astro.lsa.umich.edu/users/hughes/icon_dir/rad.html or by anonymous ftp from ra.astro.lsa.umich.edu in pub/get/hughes. Submitted to Ap.

Only connect: addressing the emotional needs of Scotland's children and young people

A report on the SNAP (Scottish Needs Assessment Programme) Child and Adolescent Mental Health Phase Two survey. It describes a survey of a wide range of professionals working with children and young people in Scotland, and deals with professional perspectives on emotional, behavioural and psychological problems. Conclusions and recommendations are presented

Police Crime Arrests in the United States, 2011

Purpose – The purpose of the study is to provide empirical data on cases of police crime arrests during the year 2011. The study identifies and describes incidents in which nonfederal sworn law enforcement officers were arrested for one or more criminal offenses. Research Design & Method – The study is a quantitative content analysis of news articles identified through the Google News search engine using 48 automated Google Alerts queries. The unit of analysis in this study is criminal arrest case (not individual arrested officer). Intercoder Reliability – The Krippendorf’s alpha coefficient is strong (Krippendorf’s α = .9153) across the variables in the study. The overall level of simple percentage of agreement between coders across all of the variables (97.7%) also established a high degree of reliability. Research limitations/implications – The data are limited to cases that involve an official arrest. The data are also the result of a filtering process that includes the exercise of media discretion as to types of news stories reported and content devoted to particular news stories. Practical Implications – The study demonstrates that an annual report on police crime arrests can provide empirical data to better understand this neglected area of research. Originality/value – The study augments the few existing studies on the topic and is the only one known to describe the phenomenon in an annual report of police crime arrests as it occurs within law enforcement agencies nationwide

Genetic associations with childhood brain growth, defined in two longitudinal cohorts

Genome-wide association studies (GWASs) are unraveling the genetics of adult brain neuroanatomy as measured by cross-sectional anatomic magnetic resonance imaging (aMRI). However, the genetic mechanisms that shape childhood brain development are, as yet, largely unexplored. In this study we identify common genetic variants associated with childhood brain development as defined by longitudinal aMRI. Genome-wide single nucleotide polymorphism (SNP) data were determined in two cohorts: one enriched for attention-deficit/hyperactivity disorder (ADHD) (LONG cohort: 458 participants; 119 with ADHD) and the other from a population-based cohort (Generation R: 257 participants). The growth of the brain's major regions (cerebral cortex, white matter, basal ganglia, and cerebellum) and one region of interest (the right lateral prefrontal cortex) were defined on all individuals from two aMRIs, and a GWAS and a pathway analysis were performed. In addition, association between polygenic risk for ADHD and brain growth was determined for the LONG cohort. For white matter growth, GWAS meta-analysis identified a genome-wide significant intergenic SNP (rs12386571, P = 9.09 × 10-9 ), near AKR1B10. This gene is part of the aldo-keto reductase superfamily and shows neural expression. No enrichment of neural pathways was detected and polygenic risk for ADHD was not associated with the brain growth phenotypes in the LONG cohort that was enriched for the diagnosis of ADHD. The study illustrates the use of a novel brain growth phenotype defined in vivo for further study

General practitioner provision of preventive child health care: analysis of routine consultation data

&lt;b&gt;Background&lt;/b&gt; GPs contribute to preventive child health care in various ways, including provision of child health surveillance (CHS) reviews, opportunistic preventive care, and more intensive support to vulnerable children. The number of CHS reviews offered in Scotland was reduced from 2005. This study aimed to quantify GPs’ provision of different types of preventive care to pre-school children before and after the changes to the CHS system.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; GP consultation rates with children aged 0–4 years were examined for the 2½ years before and after the changes to the CHS system using routinely available data from 30 practices in Scotland. Consultations for CHS reviews; other aspects of preventive care; and all reasons were considered.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results:&lt;/b&gt; Prior to the changes to the CHS system, GPs often contributed to CHS reviews at 6–8 weeks and 8–9 and 39–42 months. Following the changes, GP provision of the 6–8 week review continued but other reviews essentially ceased. Few additional consultations with pre-school children are recorded as involving other aspects of preventive care, and the changes to CHS have had no impact on this. In the 2½ years before and after the changes, consultations recorded as involving any form of preventive care accounted for 11% and 7.5% respectively of all consultations with children aged 0–4 years, with the decline due to reductions in CHS reviews.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions:&lt;/b&gt; Effective preventive care through the early years can help children secure good health and developmental outcomes. GPs are well placed to contribute to the provision of such care. Consultations focused on preventive care form a small minority of GPs’ contacts with pre-school children, however, particularly since the reduction in the number of CHS reviews

Regge and Okamoto symmetries

We will relate the surprising Regge symmetry of the Racah-Wigner 6j symbols to the surprising Okamoto symmetry of the Painleve VI differential equation. This then presents the opportunity to give a conceptual derivation of the Regge symmetry, as the representation theoretic analogue of the author's previous derivation of the Okamoto symmetry. [The resulting derivation is quite simple, so it would be surprising if it has not been previously observed. Any references would be appreciated!]Comment: 14 page

Enhancement of PCA-based fault detection system through utilising dissimilarity matrix for continuous-based process

This research is about enhancement of PCA-based fault detection system through utilizing dissimilarity matrix. Nowadays, the chemical process industry is highly based on the non-linear relationships between measured variables. However, the conventional PCA-based MSPC is no longer effective because it only valid for the linear relationships between measured variables. Due in order to solve this problem, the technique of dissimilarity matrix is used in multivariate statistical process control as alternative technique which models the non-linear process and can improve the process monitoring performance. The conventional PCA system was run and the dissimilarity system was developed and lastly the monitoring performance in each technique were compared and analysed to achieve aims of this research. This research is to be done by using Matlab software. The findings of this study are illustrated in the form of Hotelling’s T2 and Squared Prediction Errors (SPE) monitoring statistics to be analysed. As a conclusion, the dissimilarity system is comparable to the conventional method. Thus can be the other alternative ways in the process monitoring performance. Finally, it is recommended to use data from other chemical processing systems for more concrete justification of the new technique

Dynamical model of sequential spatial memory: winnerless competition of patterns

We introduce a new biologically-motivated model of sequential spatial memory which is based on the principle of winnerless competition (WLC). We implement this mechanism in a two-layer neural network structure and present the learning dynamics which leads to the formation of a WLC network. After learning, the system is capable of associative retrieval of pre-recorded sequences of spatial patterns.Comment: 4 pages, submitted to PR