Deeper Understanding Of Conditions Research Articles

Communication technologies in older people’s long-distance family relationships, and the impact on isolation and loneliness

ABSTRACT The concept ‘performance expectancy’ is used to theorize about older people’s day-to-day use of technology mediated communication (telephone, text/emails and video calls) in family relationships and the impact on social isolation and loneliness. Using theoretical and methodological triangulation six mediation models are conceptualized, followed by empirical validation using a nationally representative dataset of older people (≥ 65 years) living in Wales, UK (N = 2,099). The results reveal that frequency of telephone and video calls mediate the relationship between proximity of family and social isolation, and telephone calls mediate the relationship with loneliness. Text/emails have no significant mediating effect. Qualitative data analysis provides a deeper understanding of conditions that facilitate technology mediated communication. Demonstrating the impact of lifecourse habits, social context and environment on technology mediated communication shifts the focus from individual deficits to other reasons for non-adoption. Understanding the link between the individual, the social-cultural and social structural environment, social interaction, and loneliness requires an understanding of what is important to older people. For example, knowledge concerning the role of embodied presence in alleviating loneliness can be used to better understand the likelihood of implementing successful interventions.

Investigating a Plasmodium falciparum erythrocyte invasion phenotype switch at the whole transcriptome level

The central role that erythrocyte invasion plays in Plasmodium falciparum survival and reproduction makes this process an attractive target for therapeutic or vaccine development. However, multiple invasion-related genes with complementary and overlapping functions afford the parasite the plasticity to vary ligands used for invasion, leading to phenotypic variation and immune evasion. Overcoming the challenge posed by redundant ligands requires a deeper understanding of conditions that select for variant phenotypes and the molecular mediators. While host factors including receptor heterogeneity and acquired immune responses may drive parasite phenotypic variation, we have previously shown that host-independent changes in invasion phenotype can be achieved by continuous culturing of the W2mef and Dd2 P. falciparum strains in moving suspension as opposed to static conditions. Here, we have used a highly biologically replicated whole transcriptome sequencing approach to identify the molecular signatures of variation associated with the phenotype switch. The data show increased expression of particular invasion-related genes in switched parasites, as well as a large number of genes encoding proteins that are either exported or form part of the export machinery. The genes with most markedly increased expression included members of the erythrocyte binding antigens (EBA), reticulocyte binding homologues (RH), surface associated interspersed proteins (SURFIN), exported protein family 1 (EPF1) and Plasmodium Helical Interspersed Sub-Telomeric (PHIST) gene families. The data indicate changes in expression of a repertoire of genes not previously associated with erythrocyte invasion phenotypes, suggesting the possibility that moving suspension culture may also select for other traits.