Strategic control and medial frontal negativity: beyond errors and response conflict

Errors in timed choice tasks typically produce an error-related negativity (ERN) in the event-related potential (ERP). The error specificity of the ERN has been challenged by studies showing a correct response negativity (CRN). Forty-five participants engaged in a flanker task in which both compatibility between flankers and target and the probability of compatible flankers were manipulated. Correct responses elicited a CRN, the amplitude of which increased with the degree of mismatch between the presence of conflict and conflict probability, even on low-conflict (compatible) trials. The fronto-central N2 component was larger on high-conflict (incompatible) correct response trials. However, in contrast to some recent accounts, this N2 was largest for highly probable stimuli. These findings suggest revision to models of the effects of conflict on response-related negativity to account for strategic adjustments made in preparation for the response.     

Association between seasonal affective disorder and the 5-HT2A promoter polymorphism, -1438G/A

Genes involved in serotonin metabolism are good candidates for the pathogenesis of seasonal affective disorder (SAD). A functional variant in the serotonin transporter promoter, 5-HTTLPR, has recently been shown to be associated with SAD and seasonality. The purpose of this study was to determine whether -1438G/A, a polymorphism in the 5-HT2A promoter, is associated with SAD and seasonality, and whether it has additive effects with 5-HTTLPR on seasonality. Sixty-seven individuals with SAD and 69 normal volunteers, all screened with the SCID and diagnosed according to DSM-III-R criteria, were genotyped for the -1 438G/A 5-HT2A promoter polymorphism. All had been previously genotyped for 5-HTTLPR and had been assessed for seasonality by the Global Seasonality Scale. There was a significant increase in the frequency of the -1438A variant allele of the 5-HT2A promoter polymorphism in SAD patients (0.47) compared to matched controls (0.36) (P < 0.01). The difference in genotype distribution was also significant (P < 0.05). We found no association between the -1438G/A polymorphism and seasonality scores, and there was no additive effect with 5-HTTLPR on seasonality. In conclusion, we have shown that the -1438G/A 5-HT2A promoter variant is associated with SAD but not with seasonality. We suggest that the association may instead be with the depressive symptoms of SAD. However, these results should be treated with caution until replicated because of the possibility of false-positive findings in case-control association studies.     

Metastasis of hepatocellular carcinoma to the right colon manifested by gastrointestinal bleeding

An 82-year-old black woman with a history of hepatocellular carcinoma presented with gastrointestinal bleeding. Barium enema and fibrocolonoscopy revealed a 4-cm polypoid mass at the level of the ascending colon with evidence of active bleeding. Biopsies of the lesion proved it to be metastatic hepatocellular carcinoma. Exploratory laparotomy revealed no further dissemination of the tumor, and the patient underwent an ileocolectomy. The serosal side of the colonic lesion was free from tumor, and there was no peritoneal implantation, direct extension, or lymph node involvement. This case represents an extremely rare presentation of metastatic hepatocellular carcinoma.     

Exploring the online learning experience of first-year speech–language pathology students in a Johannesburg-based university

BackgroundUnderstanding the learning experiences of first-year speech–language pathology (SLP) students during the coronavirus disease 2019 (COVID-19) pandemic is essential to ensure that academic staff are able to support and enhance the transition from secondary to tertiary education. An understanding of the student experience could lead to improved support strategies that could be beneficial for the blended learning environment that the University of the Witwatersrand will be entering from 2022.ObjectivesThis research explored the experiences of first-year SLP students in online learning during the COVID-19 pandemic.MethodAn exploratory mixed-method concurrent triangulation design was employed. Quantitative data were collected from likert scales. Qualitative data were collected from critical incident timelines. Themes were identified from both the Likert scales as well as the critical incident timelines using bottom-up thematic analysis.ResultsThe majority of participants reflected that their online learning through the pandemic in 2021 was successful. The themes that emerged from this year pertain to 2021 and the specific participants however, it provides an important insight that the students’ needs change during a year. As a lecturer, one needs to consider these evolving needs to ensure students have the support that they require to be successful in their learning.ConclusionThis research provided insights into the evolving nature of the support first-year SLP students require in the online learning space during the COVID-19 pandemic.     

sHLA-G expression: is it really worth measuring?

HLA-G is believed to play a pivotal role in the immunoprotection of the semiallogenic embryo. Its expression during pre- and early implantation is correlated with the cleavage rate of the embryo. Studies in congenic mice have revealed that mRNA of both the maternal and paternal haplotypes are present in zygotes and in embryos at all stages of development.