Acceptability of digital vending machines to access STI and HIV tests in two UK cities.

OBJECTIVES: Prompt HIV and STI diagnosis and treatment is a public health priority and relies on accessible testing. Technology-based approaches to distribute test kits have the potential to increase access to testing. We evaluated the acceptability and uptake of vending machines in publicly available settings in Brighton and Hove (BH) and Bristol, North Somerset and South Gloucestershire (BNSSG), to distribute HIV rapid self-test and STI self-sample kits. METHODS: Seven machines were installed in BH and four in BNSSG. User characteristics, proportion of kits returned and test results, taken from the machine database and clinic records, combined with online questionnaires completed by self-recruited users and analysed using Stata and SPSS. RESULTS: 2536 kits were dispensed over 12 months (April 2022 to March 2023). The STI self-sample kits were most popular (74% of vends). 78% of kits dispensed were among users aged 16-35 years and 56% identified as male. 68% and 59% of users had either not tested in the last 12 months or never tested for HIV and STIs, respectively. 51% of STI kits were returned via post, lower than the local online service (65%). 208 users completed questionnaires. Convenience, desire for instant access and increased confidentiality were the most common reasons for using machines. 92% of respondents thought the machines were user-friendly and 97% would recommend the service. Concerns about safety and privacy while using the machine were reported by 42% and 66% of respondents. CONCLUSIONS: This study demonstrates that vending machines are an acceptable and effective means of accessing infrequent or never testers in the general population and can act as a horizontal intervention to tackle HIV and STIs. Research is needed to understand optimal machine locations to assure privacy and safety along with the long-term impact on sexual health services.

A living vector field reveals constraints on galactose network induction in yeast.

When a cell encounters a new environment, its transcriptional response can be constrained by its history. For example, yeast cells in galactose induce GAL genes with a speed and unanimity that depends on previous nutrient conditions. Cellular memory of long-term glucose exposure delays GAL induction and makes it highly variable with in a cell population, while other nutrient histories lead to rapid, uniform responses. To investigate how cell-level gene expression dynamics produce population-level phenotypes, we built living vector fields from thousands of single-cell time courses of the proteins Gal3p and Gal1p as cells switched to galactose from various nutrient histories. We show that, after sustained glucose exposure, the lack of these GAL transducers leads to induction delays that are long but also variable; that cellular resources constrain induction; and that bimodally distributed expression levels arise from lineage selection-a subpopulation of cells induces more quickly and outcompetes the rest. Our results illuminate cellular memory in this important model system and illustrate how resources and randomness interact to shape the response of a population to a new environment.

Qualitative evaluation of digital vending machines to improve access to STI and HIV testing in South West England: using a Person-Based Approach.

OBJECTIVES: To report the development, implementation, acceptability and feasibility of vending machines offering HIV and sexually transmitted infection (STI) testing kits. DESIGN: A qualitative study using the Person-Based Approach with patient and public involvement workshops and stakeholder involvement and interviews with machine users, sexual health service (SHS) staff, venue staff and local authority sexual health commissioners. Transcripts were analysed thematically. SETTING: Bristol, North Somerset and South Gloucestershire (BNSSG). PARTICIPANTS: 15 machine users, 5 SHS staff, 3 venue staff and 3 local authority commissioners. INTERVENTION: Four vending machines dispensing free HIV self-testing and STI self-sampling kits in publicly accessible venues across BNSSG were introduced to increase access to testing for groups at higher risk of HIV and STI infection who are less likely to access SHS clinic testing services (young people, people from black communities, and gay, bisexual and other men who have sex with men). RESULTS: Machine users reported the service was convenient, easy to use and accessible; however, concerns regarding privacy related to machine placement within the venues and issues of maintenance were raised. Promotional material was inclusive and informative; however, awareness of the service through the promotional campaign was limited. Vending machines were acceptable to venue staff once clear processes for their management were agreed with the SHS. SHS staff identified challenges with the implementation of the service related to the limited involvement of the whole SHS team in the planning and development. CONCLUSIONS: The codeveloped vending machine service was acceptable, addressing some barriers to testing. Resources and protected staff time are needed to support greater involvement of the whole SHS team and service providers in venues. Adopting a similarly robust coproduction approach to the implementation of the machines could avoid the challenges reported. The placement of the machines to assure users privacy and repeated, targeted promotion could encourage service use among target groups.

Evolutionary constraint and adaptation in the metabolic network of Drosophila.

Organisms must carefully control their metabolism in order to survive. On the other hand, enzymes must adapt in response to evolutionary pressures on the pathways in which they are imbedded. Taking advantage of the newly available whole-genome sequences of 12 Drosophila species, we examined how protein function and metabolic network architecture influence rates of enzyme evolution. We found that despite high overall constraint, there were significant differences in rates of amino acid substitution among functional classes of enzymes. This heterogeneity arises because proteins involved in the metabolism of foreign compounds evolve relatively rapidly, whereas enzymes that act in "core" metabolism exhibit much slower rates of amino acid replacement, suggesting strong selective constraint. Network architecture also influences enzymes' rates of amino acid replacement. In particular, enzymes that share metabolites with many other enzymes are relatively constrained, although apparently not because they are more likely to be essential. Our analyses suggest that this pattern is driven by strong constraint of enzymes acting at branch points in metabolic pathways. We conclude that metabolic network architecture and enzyme function separately affect enzyme evolution rates.

Writing in your own voice: An intervention that reduces plagiarism and common writing problems in students' scientific writing.

In many of our courses, particularly laboratory courses, students are expected to engage in scientific writing. Despite various efforts by other courses and library resources, as instructors we are often faced with the frustration of student plagiarism and related writing problems. Here, we describe a simple Writing in Your Own Voice intervention designed to help students become more aware of different types of plagiarism and writing problems, avoid those problems, and practice writing in their own voice. In this article, we will introduce the types of plagiarism and writing problems commonly encountered in our molecular biology laboratory course, the intervention, and the results of our study. From the evaluation of 365 student reports, we found the intervention resulted in nearly 50% fewer instances of plagiarism and common writing problems. We also observed significantly fewer instances of severe plagiarism (e.g. several sentences copied from an external source). In addition, we find that the effects last for several weeks after the students complete the intervention assignment. This assignment is particularly easy to implement and can be a very useful tool for teaching students how to write in their own voices. © 2019 International Union of Biochemistry and Molecular Biology, 47(5):589-598, 2019.

The yeast galactose network as a quantitative model for cellular memory.

Recent experiments have revealed surprising behavior in the yeast galactose (GAL) pathway, one of the preeminent systems for studying gene regulation. Under certain circumstances, yeast cells display memory of their prior nutrient environments. We distinguish two kinds of cellular memory discovered by quantitative investigations of the GAL network and present a conceptual framework for interpreting new experiments and current ideas on GAL memory. Reinduction memory occurs when cells respond transcriptionally to one environment, shut down the response during several generations in a second environment, then respond faster and with less cell-to-cell variation when returned to the first environment. Persistent memory describes a long-term, arguably stable response in which cells adopt a bimodal or unimodal distribution of induction levels depending on their preceding environment. Deep knowledge of how the yeast GAL pathway responds to different sugar environments has enabled rapid progress in uncovering the mechanisms behind GAL memory, which include cytoplasmic inheritance of inducer proteins and positive feedback loops among regulatory genes. This network of genes, long used to study gene regulation, is now emerging as a model system for cellular memory.