Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/12064
Felix Atuhaire, B. Egger, Tinashe Ernest Mutsvangwa
Foetal alcohol syndrome (FAS) is a preventable condition caused by maternal alcohol consumption during pregnancy. The FAS facial phenotype is an important factor for diagnosis, alongside central nervous system impairments and growth abnormalities. Current methods for analysing the FAS facial phenotype rely on 3D facial image data, obtained from costly and complex surface scanning devices. An alternative is to use 2D images, which are easy to acquire with a digital camera or smart phone. However, 2D images lack the geometric accuracy required for accurate facial shape analysis. Our research offers a solution through the reconstruction of 3D human faces from single or multiple 2D images. We have developed a framework for evaluating 3D human face reconstruction from a single-input 2D image using a 3D face model for potential use in FAS assessment. We first built a generative morphable model of the face from a database of registered 3D face scans with diverse skin tones. Then we applied this model to reconstruct 3D face surfaces from single frontal images using a model-driven sampling algorithm. The accuracy of the predicted 3D face shapes was evaluated in terms of surface reconstruction error and the accuracy of FAS-relevant landmark locations and distances. Results show an average root mean square error of 2.62 mm. Our framework has the potential to estimate 3D landmark positions for parts of the face associated with the FAS facial phenotype. Future work aims to improve on the accuracy and adapt the approach for use in clinical settings.
{"title":"Evaluating 3D human face reconstruction from a frontal 2D image, focusing on facial regions associated with foetal alcohol syndrome","authors":"Felix Atuhaire, B. Egger, Tinashe Ernest Mutsvangwa","doi":"10.17159/sajs.2023/12064","DOIUrl":"https://doi.org/10.17159/sajs.2023/12064","url":null,"abstract":"Foetal alcohol syndrome (FAS) is a preventable condition caused by maternal alcohol consumption during pregnancy. The FAS facial phenotype is an important factor for diagnosis, alongside central nervous system impairments and growth abnormalities. Current methods for analysing the FAS facial phenotype rely on 3D facial image data, obtained from costly and complex surface scanning devices. An alternative is to use 2D images, which are easy to acquire with a digital camera or smart phone. However, 2D images lack the geometric accuracy required for accurate facial shape analysis. Our research offers a solution through the reconstruction of 3D human faces from single or multiple 2D images. We have developed a framework for evaluating 3D human face reconstruction from a single-input 2D image using a 3D face model for potential use in FAS assessment. We first built a generative morphable model of the face from a database of registered 3D face scans with diverse skin tones. Then we applied this model to reconstruct 3D face surfaces from single frontal images using a model-driven sampling algorithm. The accuracy of the predicted 3D face shapes was evaluated in terms of surface reconstruction error and the accuracy of FAS-relevant landmark locations and distances. Results show an average root mean square error of 2.62 mm. Our framework has the potential to estimate 3D landmark positions for parts of the face associated with the FAS facial phenotype. Future work aims to improve on the accuracy and adapt the approach for use in clinical settings.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45336924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/12126
C. Tredoux, Ahmed M. Megreya, Alicia Nortje, Kate Kempen
Face recognition is biased in favour of in-group identity, particularly strongly for race or ethnicity but to some extent also for sex and age. This ‘own group bias’ (OGB) can have profound implications in practical settings, with incorrect identification of black suspects by white witnesses constituting 40% of criminal exonerations investigated by the Innocence Project. Although authors have offered several explanations for the OGB in face recognition, there is little consensus, apart from the acknowledgement that the bias must reflect perceptual learning history. One matter that is not currently clear is whether the bias occurs at encoding, or at retrieval from memory. We report an experiment designed to tease out bias at encoding, versus bias at retrieval. Black and white South African participants encoded 16 target faces of both the same and other race and gender, and attempted immediately afterward to match the target faces to members of photograph arrays that either contained or did not contain the targets. After a further delay, they attempted to identify the faces they had encoded from memory. Results showed a strong crossover OGB in the delayed matching task, but an asymmetrical OGB at retrieval (only white participants showed the OGB). Further investigation of recognition performance, considering only images correctly matched in the delayed matching task, showed a narrowly non-significant OGB at retrieval, but the investigation was likely not sufficiently powered to discover the effect, if it exists.
{"title":"Changes in the own group bias across immediate and delayed recognition tasks","authors":"C. Tredoux, Ahmed M. Megreya, Alicia Nortje, Kate Kempen","doi":"10.17159/sajs.2023/12126","DOIUrl":"https://doi.org/10.17159/sajs.2023/12126","url":null,"abstract":"Face recognition is biased in favour of in-group identity, particularly strongly for race or ethnicity but to some extent also for sex and age. This ‘own group bias’ (OGB) can have profound implications in practical settings, with incorrect identification of black suspects by white witnesses constituting 40% of criminal exonerations investigated by the Innocence Project. Although authors have offered several explanations for the OGB in face recognition, there is little consensus, apart from the acknowledgement that the bias must reflect perceptual learning history. One matter that is not currently clear is whether the bias occurs at encoding, or at retrieval from memory. We report an experiment designed to tease out bias at encoding, versus bias at retrieval. Black and white South African participants encoded 16 target faces of both the same and other race and gender, and attempted immediately afterward to match the target faces to members of photograph arrays that either contained or did not contain the targets. After a further delay, they attempted to identify the faces they had encoded from memory. Results showed a strong crossover OGB in the delayed matching task, but an asymmetrical OGB at retrieval (only white participants showed the OGB). Further investigation of recognition performance, considering only images correctly matched in the delayed matching task, showed a narrowly non-significant OGB at retrieval, but the investigation was likely not sufficiently powered to discover the effect, if it exists.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48410054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/14303
S. Taljaard, L. van Niekerk, J. Adams, T. Riddin
Rapid degradation of ecosystems and loss of ecosystem services have sparked interest in developing approaches to report and integrate such change with socio-economic information systems, such as the System of National Accounts. Here we describe an approach and application of ecosystem accounting for individual estuaries, building on approaches previously applied at national and bay levels. Using the Swartkops Estuary as a case study, the focus is on physical accounts for ecosystem extent and condition, as well as accounts for two important ecosystem services (carbon sequestration and recreational use). Pressure accounts are also introduced to demonstrate the value of identifying key areas for management and restoration interventions in response to changes in extent and/or condition accounts. Greater resolution in these account reports, achieved through zoning, provides spatially explicit information on ecosystem assets and their services within an estuary to also inform management decision-making at local level. Further, these accounts can also inform local restoration prioritisation, in support of the UN Decade on Ecosystem Restoration (2021–2030), for example offsetting irreversibly degraded areas in one zone with restoration or maintenance of similar habitats in another.
{"title":"Advancing ecosystem accounting in estuaries: Swartkops Estuary case study","authors":"S. Taljaard, L. van Niekerk, J. Adams, T. Riddin","doi":"10.17159/sajs.2023/14303","DOIUrl":"https://doi.org/10.17159/sajs.2023/14303","url":null,"abstract":"Rapid degradation of ecosystems and loss of ecosystem services have sparked interest in developing approaches to report and integrate such change with socio-economic information systems, such as the System of National Accounts. Here we describe an approach and application of ecosystem accounting for individual estuaries, building on approaches previously applied at national and bay levels. Using the Swartkops Estuary as a case study, the focus is on physical accounts for ecosystem extent and condition, as well as accounts for two important ecosystem services (carbon sequestration and recreational use). Pressure accounts are also introduced to demonstrate the value of identifying key areas for management and restoration interventions in response to changes in extent and/or condition accounts. Greater resolution in these account reports, achieved through zoning, provides spatially explicit information on ecosystem assets and their services within an estuary to also inform management decision-making at local level. Further, these accounts can also inform local restoration prioritisation, in support of the UN Decade on Ecosystem Restoration (2021–2030), for example offsetting irreversibly degraded areas in one zone with restoration or maintenance of similar habitats in another.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47778931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/15483
M. Wingfield, B. Wingfield
Mentorship has always been a key component of postgraduate student education, and it is becoming increasingly important in the academic environment. Strong mentorship is widely recognised as a key aspect of professional development and career success. Our view is that mentorship is a lifelong process extending beyond just teaching, and encompasses a wide range of aspects of the relationship between someone who is more experienced and someone who is less experienced people. We see this as a two-way process, where both mentee and mentor benefit. It is ideally a personal relationship in which mentors are well respected in their fields, earning the respect of their mentees, who benefit from the ideas, insights and skills of their mentors. We argue that the lives and careers of both students and academics would benefit from universities establishing formal, non-bureaucratic structures to promote positive mentorship.
{"title":"Musings on mentorship","authors":"M. Wingfield, B. Wingfield","doi":"10.17159/sajs.2023/15483","DOIUrl":"https://doi.org/10.17159/sajs.2023/15483","url":null,"abstract":"Mentorship has always been a key component of postgraduate student education, and it is becoming increasingly important in the academic environment. Strong mentorship is widely recognised as a key aspect of professional development and career success. Our view is that mentorship is a lifelong process extending beyond just teaching, and encompasses a wide range of aspects of the relationship between someone who is more experienced and someone who is less experienced people. We see this as a two-way process, where both mentee and mentor benefit. It is ideally a personal relationship in which mentors are well respected in their fields, earning the respect of their mentees, who benefit from the ideas, insights and skills of their mentors. We argue that the lives and careers of both students and academics would benefit from universities establishing formal, non-bureaucratic structures to promote positive mentorship.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46433494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/15803
L. Swartz, Linda Fick, Na Grobler, Henriette Wagener
{"title":"The year that was 2022: Looking back and looking ahead","authors":"L. Swartz, Linda Fick, Na Grobler, Henriette Wagener","doi":"10.17159/sajs.2023/15803","DOIUrl":"https://doi.org/10.17159/sajs.2023/15803","url":null,"abstract":"","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44081611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/15739
Penelope J. Mograbi, E. Archer, C. Fabricius, R. Wynberg, J. Donaldson
Significance: A recent report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) assessed how the sustainable use of wild species benefits people and nature, and which policies work best to prevent unsustainable exploitation. In the context of an accelerating and alarming biodiversity crisis, the assessment findings have important implications for South Africa, a megadiverse country with a population that relies extensively on the use of wild species for food, energy, medicine, and income, amongst many other purposes. This Commentary reflects on implications of the IPBES assessment for South Africa, drawing on insights from local contributing authors.
{"title":"The sustainable use of wild species benefits biodiversity and human well-being in South Africa","authors":"Penelope J. Mograbi, E. Archer, C. Fabricius, R. Wynberg, J. Donaldson","doi":"10.17159/sajs.2023/15739","DOIUrl":"https://doi.org/10.17159/sajs.2023/15739","url":null,"abstract":"Significance: A recent report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) assessed how the sustainable use of wild species benefits people and nature, and which policies work best to prevent unsustainable exploitation. In the context of an accelerating and alarming biodiversity crisis, the assessment findings have important implications for South Africa, a megadiverse country with a population that relies extensively on the use of wild species for food, energy, medicine, and income, amongst many other purposes. This Commentary reflects on implications of the IPBES assessment for South Africa, drawing on insights from local contributing authors.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45361761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/15663
C. Tredoux, Alicia Nortje
The faces of animals are central to their functioning in lived environments. For mammals, faces are usually the location of the sense organs, and thus provide the primary way of living in umwelten1 (umwelt is the world as experienced by a particular organism). Mammalian faces are also an important location of non-verbal communication and expression, and convey a wide range of emotional and social information; for humans and many other primates, faces are also key for personal identity. The special significance of the face is likely the reason that the brains of primates have multiple face-selective cortical areas, the most well-known region in humans being the fusiform face area.2
{"title":"What’s in a face? Introducing the special section on Face Science.","authors":"C. Tredoux, Alicia Nortje","doi":"10.17159/sajs.2023/15663","DOIUrl":"https://doi.org/10.17159/sajs.2023/15663","url":null,"abstract":"The faces of animals are central to their functioning in lived environments. For mammals, faces are usually the location of the sense organs, and thus provide the primary way of living in umwelten1 (umwelt is the world as experienced by a particular organism). Mammalian faces are also an important location of non-verbal communication and expression, and convey a wide range of emotional and social information; for humans and many other primates, faces are also key for personal identity. The special significance of the face is likely the reason that the brains of primates have multiple face-selective cortical areas, the most well-known region in humans being the fusiform face area.2","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47035331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/15485
J. Jansen
{"title":"Learning from COVID-19: A social science perspective on pandemic medicine. Comments on Benatar (S Afr J Sci. 2022;118(11/12))","authors":"J. Jansen","doi":"10.17159/sajs.2023/15485","DOIUrl":"https://doi.org/10.17159/sajs.2023/15485","url":null,"abstract":"","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47570416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/15658
R. Mash
{"title":"Climate change, global health and the post-COVID world. Comments on Benatar (S Afr J Sci. 2022;118(11/12))","authors":"R. Mash","doi":"10.17159/sajs.2023/15658","DOIUrl":"https://doi.org/10.17159/sajs.2023/15658","url":null,"abstract":"","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49470439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.17159/sajs.2023/12102
Milton Gering, T. Johnson, C. Tredoux
The effect of stress on face identification is not yet clear, with recent experiments finding positive, negative and null results. Here we report the results of two experiments examining the effect of stress on eyewitness performance in line-up face recognition tasks. Both experiments use a stress manipulation and live mock crime paradigm to examine the relationship between stress at encoding and subsequent line-up performance. Experiment 1 replicated an experiment by Sauerland et al. (Behav Sci Law. 2016;34(4):580–594) which induced stress using the Maastricht Acute Stress Test. The replication found the same null result as the original experiment. Experiment 2 aimed to address a limitation of many laboratory experiments which dichotomise stress into low and high groups for comparison. As the Yerkes-Dodson law (1908) suggests that a non-linear relationship exists between stress and performance, it was hypothesised that using a low, medium and high stress manipulation might show clearer results than a dichotomous paradigm. The results of Experiment 2 show a non-linear relationship, with no difference between the low and high stress groups but better performance by the middle stress group. The results suggest that a different approach is required in experiments on stress and face recognition, as the stress–performance relationship is likely non-linear.
{"title":"Non-linear effects of stress on eyewitness memory","authors":"Milton Gering, T. Johnson, C. Tredoux","doi":"10.17159/sajs.2023/12102","DOIUrl":"https://doi.org/10.17159/sajs.2023/12102","url":null,"abstract":"The effect of stress on face identification is not yet clear, with recent experiments finding positive, negative and null results. Here we report the results of two experiments examining the effect of stress on eyewitness performance in line-up face recognition tasks. Both experiments use a stress manipulation and live mock crime paradigm to examine the relationship between stress at encoding and subsequent line-up performance. Experiment 1 replicated an experiment by Sauerland et al. (Behav Sci Law. 2016;34(4):580–594) which induced stress using the Maastricht Acute Stress Test. The replication found the same null result as the original experiment. Experiment 2 aimed to address a limitation of many laboratory experiments which dichotomise stress into low and high groups for comparison. As the Yerkes-Dodson law (1908) suggests that a non-linear relationship exists between stress and performance, it was hypothesised that using a low, medium and high stress manipulation might show clearer results than a dichotomous paradigm. The results of Experiment 2 show a non-linear relationship, with no difference between the low and high stress groups but better performance by the middle stress group. The results suggest that a different approach is required in experiments on stress and face recognition, as the stress–performance relationship is likely non-linear.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48437599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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