Utilisation and usefulness of face composites in the South African Police Service - an evaluation study

The current study investigates the degree to which face composites are utilised as an investigative tool in the South African Police Service. The article provides an overview of the conditions under which composites are produced by eyewitnesses to a crime, and points out constraints in terms of their usefulness and applicability. Composites were found to be produced after a longer delay than is recommended, and predominantly in violent and menacing crimes. Conviction rates for composite-related crimes were very low. However, more insight into actual use and case characteristics is needed before concluding on the usefulness of composites as an investigative tool or evidence. Directions for further research in this area are explored

Expression of schizophrenia in black Xhosa-speaking and white English-speaking South Africans

Objective. To inv:estigate whether schizophrenia manifests itself differently in  Xhosa-speaking South Africans, compared with English-speaking white South  Africans.Design. A comparative study ·of the presentation of schizophrenia in two groups of patients.Settings and subjects. A sample of 63 patients (43 Xhosaspeaking and 20 English-speaking) admitted to a large psychiatric hospital for the first time with a diagnosis of schizophrenia.Outcome measures. The Present State Examination (PSE) was used to confirm the clinical diagnosis of schizophrenia. The Relatives' Rating of Symptoms and Social Behaviour (KAS-R) was used to obtain information on the behavioural and emotional expression of schizophrenia.Results. A significantly higher prevalence of aggressive and disruptive behaviour was reported by relatives of Xhosaspeaking patients with schizophrenia of recent onset compared with English-speaking patients. The PSE elicited significantly more delusions of persecution, sexual and fantastic delusions, self-neglect and irritability in the Xhosaspeaking patients.Canclusion. Significant differences in the presentation of schizophrenia, but not its core symptoms, were identified in . Xhosa-speaking blacks and English-speaking whites

Fuzzy Bayesian inference for mapping vague and place-based regions: a case study of sectarian territory

The problem of mapping regions with socially-derived boundaries has been a topic of discussion in the GIS literature for many years. Fuzzy approaches have frequently been suggested as solutions, but none have been adopted. This is likely due to difficulties associated with determining suitable membership functions, which are often as arbitrary as the crisp boundaries that they seek to replace. This paper presents a novel approach to fuzzy geographical modelling that replaces the membership function with a possibility distribution that is estimated using Bayesian inference. In this method, data from multiple sources are combined to estimate the degree to which a given location is a member of a given set and the level of uncertainty associated with that estimate. The Fuzzy Bayesian Inference approach is demonstrated through a case study in which census data are combined with perceptual and behavioural evidence to model the territory of two segregated groups (Catholics and Protestants) in Belfast, Northern Ireland, UK. This novel method provides a robust empirical basis for the use of fuzzy models in GIS, and therefore has applications for mapping a range of socially-derived and otherwise vague boundaries

InterFace : A software package for face image warping, averaging, and principal components analysis

We describe InterFace, a software package for research in face recognition. The package supports image warping, reshaping, averaging of multiple face images, and morphing between faces. It also supports principal components analysis (PCA) of face images, along with tools for exploring the “face space” produced by PCA. The package uses a simple graphical user interface, allowing users to perform these sophisticated image manipulations without any need for programming knowledge. The program is available for download in the form of an app, which requires that users also have access to the (freely available) MATLAB Runtime environment

Extreme enrichment of Se, Te, PGE and Au in Cu sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland

The Platinova Reef, in the Skaergaard Intrusion, east Greenland, is an example of a magmatic Cu–PGE–Au sulfide deposit formed in the latter stages of magmatic differentiation. As is characteristic with such deposits, it contains a low volume of sulfide, displays peak metal offsets and is Cu rich but Ni poor. However, even for such deposits, the Platinova Reef contains extremely low volumes of sulfide and the highest Pd and Au tenor sulfides of any magmatic ore deposit. Here, we present the first LA-ICP-MS analyses of sulfide microdroplets from the Platinova Reef, which show that they have the highest Se concentrations (up to 1200 ppm) and lowest S/Se ratios (190–700) of any known magmatic sulfide deposit and have significant Te enrichment. In addition, where sulfide volume increases, there is a change from high Pd-tenor microdroplets trapped in situ to larger, low tenor sulfides. The transition between these two sulfide regimes is marked by sharp peaks in Au, and then Te concentration, followed by a wider peak in Se, which gradually decreases with height. Mineralogical evidence implies that there is no significant post-magmatic hydrothermal S loss and that the metal profiles are essentially a function of magmatic processes. We propose that to generate these extreme precious and semimetal contents, the sulfides must have formed from an anomalously metal-rich package of magma, possibly formed via the dissolution of a previously PGE-enriched sulfide. Other processes such as kinetic diffusion may have also occurred alongside this to produce the ultra-high tenors. The characteristic metal offset pattern observed is largely controlled by partitioning effects, producing offset peaks in the order Pt+Pd>Au>Te>Se>Cu that are entirely consistent with published D values. This study confirms that extreme enrichment in sulfide droplets can occur in closed-system layered intrusions in situ, but this will characteristically form ore deposits that are so low in sulfide that they do not conform to conventional deposit models for Cu–Ni–PGE sulfides which require very high R factors, and settling of sulfide liquids

Individual differences in eyewitness accuracy across multiple lineups of faces

Theories of face recognition in cognitive psychology stipulate that the hallmark of accurate identification is the ability to recognize a person consistently, across different encounters. In this study, we apply this reasoning to eyewitness identification by assessing the recognition of the same target person repeatedly, over six successive lineups. Such repeat identifications are challenging and can be performed only by a proportion of individuals, both when a target exhibits limited and more substantial variability in appearance across lineups (Experiments 1 and 2). The ability to do so correlates with individual differences in identification accuracy on two established tests of unfamiliar face recognition (Experiment 3). This indicates that most observers have limited facial representations of target persons in eyewitness scenarios, which do not allow for robust identification in most individuals, partly due to limitations in their ability to recognize unfamiliar faces. In turn, these findings suggest that consistency of responses across multiple lineups of faces could be applied to assess which individuals are accurate eyewitnesses

Predictors of mathematics and literacy skills at 15 years old in Ethiopia, India, Peru and Vietnam: A longitudinal analysis

This working paper reports on longitudinal analyses of predictors of growth in receptive vocabulary and mathematics abilities by age 15 conducted using data from the Younger Cohort in the four Young Lives countries. Theoretical models of plausible influences on these outcomes were constructed. Latent Growth Modelling undertaken on these two key aspects of development provides unusually powerful cross-country evidence that household economic well-being and proximal relationships in the early childhood environment are particularly important, either placing young children at risk of developmental hazards such as growth stunting or conferring advantage for future development. The models indicate that children whose mothers are rendered psychologically vulnerable by the stresses of poverty are at risk of poor physical growth in the early years, and that this impacts language, cognition and numeracy skills across childhood. Early disadvantages in poorer children are compounded by challenges of combining household responsibilities with schooling from middle childhood through adolescence. Those children with better-educated mothers are more likely to attend preschool programmes, which contribute to improved learning outcomes. While not directly measured, it is likely that those who made most gains attended programmes that were better provisioned. While there is variation across the countries, the high degree of similarity suggests good external validity of the general findings

Jumping to conclusions: An overview of inferential statistical methods. In M. Terre Blanche, K. Durrheim & D. Painter (Eds.)

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Evaluating research design. In M. Terre Blanche, K. Durrheim & D. Painter (Eds.)

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Multivariate data analysis. In M. Terre Blanche, K. Durrheim & D. Painter (Eds.),

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