Sizes of Confirmed Globular Clusters in NGC 5128: A Wide-Field High-Resolution Study

Using Magellan/IMACS images covering a 1.2 x 1.2 sq. degree FOV with seeing of 0.4"-0.6", we have applied convolution techniques to analyse the light distribution of 364 confirmed globular cluster in the field of NGC 5128 and to obtain their structural parameters. Combining these parameters with existing Washington photometry from Harris et al. (2004), we are able to examine the size difference between metal-poor (blue) and metal-rich (red) globular clusters. For the first time, this can be addressed on a sample of confirmed clusters that extends to galactocentric distances about 8 times the effective radius, R$_{eff}$, of the galaxy. Within 1 R$_{eff}$, red clusters are about 30% smaller on average than blue clusters, in agreement with the vast majority of extragalactic globular cluster systems studied. As the galactocentric distance increases, however, this difference becomes negligible. Thus, our results indicate that the difference in the clusters' effective radii, r$_e$, could be explained purely by projection effects, with red clusters being more centrally concentrated than blue ones and an intrinsic r$_e$--R$_{gc}$ dependence, like the one observed for the Galaxy.Comment: 4 figures, accepted for publication in ApJ

The Contribution of Assistant Psychologists in the UK

Within the context of changes to the model of service delivery of Educational Psychology Services in the United Kingdom (Lee & Woods, 2017), the purpose of the current review was to explore the contribution of paraprofessionals within psychological services. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework (Moher, Liberati, Tetzlaff, Altman, & The PRISMA Group, 2009) was used to search, screen and identify research relevant to psychology paraprofessionals. Following exploration through relevant databases, seven studies met the criteria for inclusion in the current review. The findings outlined the contribution of assistant psychologists in the UK and the potential wide remit of the role was uncovered, including contributions at a service level and direct work with service users. Key features to facilitate the successful deployment of assistants were highlighted. The association between employment as an assistant psychologist and subsequent progression into professional training was also revealed

The History of Desegregation and the Theory of Student Choice

Diversity of the student population is legislated and affects recruitment strategies at colleges and university. There is much legal history bringing administrators to the current position. Blending the history of desegregation and the resultant legal situation with the Theory of Student Choice is important to ensure enrollment targets are met. Student choice factors are instrumental in determining which college a student will attend. Understanding which factors influence white students to attend HBCUs, and black students to attend TWIs, is important for administrators and will help them ensure desegregation structural diversity mandates are met. This paper reviews the legal history and the Theory of Student Choice as a beginning point to assist Institutional policy makers, and defines the need for future efforts

Self-Healing Control with Multifunctional Gate Drive Circuits for Power Converters

Many commercial and military transport systems have fault diagnostic functions implemented to help protect the device when a severe fault occurs. However, most present systems do not contain prognostics capability which would allow operators to observe an unhealthy system component in its prefault condition. in industry applications, scheduled downtime can result in considerable cost avoidance. the next technology step is self-healing system components which observe not only potential problems but can also take steps to continue operation under abnormal conditions - whether due to long-term normal wear-and-tear or sudden combat damage. in this paper, current and voltage information using the double-layer gate drive concept is fed to intelligent networks to identify the type of fault and its location. These intelligent networks are based on unsupervised and supervised learning networks (self-organizing maps and learning vector quantization networks respectively). the proposed concept allows the reconfiguration of the electric machinery system for continued normal operation of the machine. This paper presents an intelligent health monitoring and self-healing control strategy for a multi-phase multilevel motor drive under various types of faults. © 2007 IEEE

Self-Healing Control with Multifunctional Gate Drive Circuits for Power Converters

Many commercial and military transport systems have fault diagnostic functions implemented to help protect the device when a severe fault occurs. However, most present systems do not contain prognostics capability which would allow operators to observe an unhealthy system component in its pre- fault condition. In industry applications, scheduled downtime can result in considerable cost avoidance. The next technology step is self-healing system components which observe not only potential problems, but can also take steps to continue operation under abnormal conditions - whether due to long-term normal wear-and-tear or sudden combat damage. In this paper, current and voltage information using the double-layer gate drive concept is fed to intelligent networks to identify the type of fault and its location. These intelligent networks are based on unsupervised and supervised learning networks (self-organizing maps and learning vector quantization networks respectively). The proposed concept allows the reconfiguration of the electric machinery system for continued normal operation of the machine. This paper presents an intelligent health monitoring and self-healing control strategy for a multi-phase multilevel motor drive under various types of faults

S-acylated Golga7b stabilises DHHC5 at the plasma membrane to regulate desmosome assembly and cell adhesion

S-acylation is the only fully reversible lipid modification of proteins however little is known about how protein S-acyltransferases (PATs) that mediate it are regulated. DHHC5 is a plasma membrane-localised PAT with roles in synaptic plasticity, massive endocytosis and cancer cell growth/invasion. Here we demonstrate that stabilisation of DHHC5 at the plasma membrane requires binding to and palmitoylation of an accessory protein Golga7b. This interaction requires the palmitoylation of the C-terminus of DHHC5 which regulates the internalisation of DHHC5 from the plasma membrane. Proteomic analysis of DHHC5/Golga7b-associated protein complexes reveals an enrichment in adhesion proteins, particularly components of desmosomes. We show that Desmoglein-2 and Plakophilin-3 are substrates of DHHC5 and that DHHC5/Golga7b are required for localisation of Desmoglein-2 to the plasma membrane and desmosomal patterning. Loss of DHHC5/Golga7b causes functional impairments in cell adhesion suggesting these proteins have a wider role in cell adhesion beyond desmosome assembly. This work uncovers a novel mechanism of DHHC5 regulation by Golga7b and demonstrates a role for the DHHC5/Golga7b complex in the regulation of cell adhesion

Hindcasting of hurricane characteristics and observed storm damage on a fringing reef, Jamaica, West Indies

Hurricane Allen is one of the most severe hurricanes on record and caused extensive damage throughout the Caribbean in early August 1980. Coral reefs along the north coast of Jamaica were devastated by the hurricane-induced waves. As in the case of most hurricanes, no wave measurements were made. We have computed the wind field and hindcast the deep water wave characteristics as the storm impacted the fringing reef at Discovery Bay on the north central coast of Jamaica. The deep water waves propagated into shallow water on the forereef and transformed as a result of shoaling and refraction. We found that significant wave height at a given time varied by a factor of 2.6 and that incident wave power for the duration of the storm varied by a factor of 7 along a 3 km section of the Discovery Bay forereef due to variations in local bathymetry. Maximum hindcast breakers reached a height of 11.5 m with a significant wave period of 10.5 s. Observations of the most intense reef damage coincided with areas on the eastern forereef experiencing the highest breakers. We speculate that the degree of reef damage is a function of how much time has elapsed since the previous storm rather than frequency of hurricanes at a locality

Digistain: a novel biomarker imaging platform for grading breast carcinoma using routinely processed paraffin sections

Objective: Digistain is a new technology platform that enables imaging and quantification of a newly conceived biomarker for grading breast carcinoma in routinely processed, unstained paraffin sections without the use of traditional stains or contrasting agents. By recording a unique optical signature to analyze the chemical make-up of a biopsy quantitatively, the technique is unaffected by the subjectivity of traditional grading. Within minutes of loading a slide it yields a highly reproducible and user independent numerical score reflecting the cellularity of the tumour and its nuclear: cytoplasmic ratio. We report here our findings using an objective technique to grade breast tumours using quantitative criteria. Method: H&E stained sections from excision biopsies of 105 cases of invasive breast carcinoma were reviewed and graded using the ElstonEllis grading system. Unstained sections from each case were loaded into the Digistain platform to yield a numerical score - the Digistain Index (DI). Results: The cases were grouped according to histological grading. Mean DIs was calculated for each grade (1,2 and 3) to be 0.56, 0.61, and 0.68 respectively with a maximum standard error of 0.02. The DI spread within each grade was less than that across the three grades, thus validating this index as a viable grading indicator within the context of this study. Conclusion: We believe the new Digistain approach provides for the first time a cost effective and quantitative measure of tumour grade. This can be developed to deliver an effective assessment of prognosis and recurrence risk beyond traditional qualitative measures based on H&E staining protocols

Deep HST Imaging in NGC 6397: Stellar Dynamics

Multi-epoch observations with ACS on HST provide a unique and comprehensive probe of stellar dynamics within NGC 6397. We are able to confront analytic models of the globular cluster with the observed stellar proper motions. The measured proper motions probe well along the main sequence from 0.8 to below 0.1 M$_\odot$ as well as white dwarfs younger than one gigayear. The observed field lies just beyond the half-light radius where standard models of globular cluster dynamics (e.g. based on a lowered Maxwellian phase-space distribution) make very robust predictions for the stellar proper motions as a function of mass. The observed proper motions show no evidence for anisotropy in the velocity distribution; furthermore, the observations agree in detail with a straightforward model of the stellar distribution function. We do not find any evidence that the young white dwarfs have received a natal kick in contradiction with earlier results. Using the observed proper motions of the main-sequence stars, we obtain a kinematic estimate of the distance to NGC 6397 of $2.2^{+0.5}_{-0.7}$ kpc and a mass of the cluster of $1.1 \pm 0.1 \times 10^5 \mathrm{M}_\odot$ at the photometric distance of 2.53 kpc. One of the main-sequence stars appears to travel on a trajectory that will escape the cluster, yielding an estimate of the evaporation timescale, over which the number of stars in the cluster decreases by a factor of e, of about 3 Gyr. The proper motions of the youngest white dwarfs appear to resemble those of the most massive main-sequence stars, providing the first direct constraint on the relaxation time of the stars in a globular cluster of greater than or about 0.7 Gyr.Comment: 25 pages, 20 figures, accepted for publication in Astrophysical Journa