Search

The seminal dual coding theory by Paivio (1971) posited that non- verbal and verbal stimuli differ in their representational format, whereby the former activates a dual code while the latter only one. These differences in code have implications for tasks such as visual search. The current eye-tracking visual search study aims to re- evaluate this theoretical framework while examining the role played by semantic processing that has never been looked at before. We followed the original design by Paivio and Begg (1974), with participants searching for a target, cued either by a word or a picture, in an array of either words or pictures. The target could be either semantically related or unrelated to the other distractors. Corroborating original results, response times for correct trials werefaster in pictorial arrays and substantially slower when a cued picture had to be found in a word array. Semantically unrelated targets were looked at faster for longer, leading to shorter search responses than semantically related targets. Critically, these effects driven by semantic relatedness were amplified when codes had to be converted (e.g., picture-to-word). Our findings refine our understanding of the role semantic processing plays in therepresentational format of words and pictures and the implications it carries for visual search.

Abstract Background Voluntary assisted partner notification (VAPN) in HIV contact tracing is a globally recommended strategy to identify persons who have been exposed to HIV and link them to HIV testing and follow-up. However, there is little understanding about how VAPN is experienced by stakeholders in sub-Saharan African (SSA) contexts. We conducted a multi-level and multi-national qualitative analysis evaluating stakeholder perspectives surrounding VAPN implementation to inform the development of future VAPN policies. Method We conducted in-depth interviews (IDIs) with VAPN stakeholders at global (n = 5), national (n = 6), and community level (n = 4) across a total of seven SSA countries. Eligible participants were ≥ 18 years old and had experience developing, implementing, or overseeing VAPN policies in SSA. We sought to understand stakeholder’s perspectives on policy development, implementation, and perceived outcomes (barriers and facilitators). Interviews were audio recorded, transcribed, and analyzed thematically using a combination of inductive and deductive approaches. Results Between December 2019 and October 2020 we conducted 15 IDIs. While participants agreed that VAPN resulted in a high yield of people newly diagnosed with HIV; they noted numerous barriers surrounding VAPN implementation across global, national, and community levels, the majority of which were identified at community level. Barriers at global and national level included high target setting, contradictory laws, and limited independent research disenfranchising the experiences of implementing partners. The barriers identified at community level included client-level challenges (e.g., access to healthcare facilities and fear of adverse events); healthcare worker challenges (e.g., high workloads); limited data infrastructure; and cultural/gender norms that hindered women from engaging in HIV testing and VAPN services. In response to these barriers, participants shared implementation facilitators to sustain ethical implementation of VAPN services (e.g., contact tracing methods) and increase its yield (e.g., HIV self-testing integrated with VAPN services). Conclusion Overall, stakeholders perceived VAPN implementation to encounter barriers across all implementation levels (global to community). Future VAPN policies should be designed around the barriers and facilitators identified by SSA stakeholders to maximize the implementation of (ethical) HIV VAPN services and increase its impact in sub-Saharan African settings.

Background Adolescent malnutrition is a significant public health challenge in low-income and middle-income countries (LMICs), with long-term consequences for health and development. Community-based interventions have the potential to address multiple forms of malnutrition and improve the health outcomes of adolescents. However, there is a limited understanding of the content, implementation and effectiveness of these interventions. This scoping review aims to synthesise evidence on community-based interventions targeting multiple forms of malnutrition among adolescents in LMICs and describe their effects on nutrition and health.Methods and analysis A comprehensive search strategy will be implemented in multiple databases including MEDLINE (through PubMed), Embase, CENTRAL (through Cochrane Library) and grey literature, covering the period from 1 January 2000 to 14 July 2023. We will follow the Participants, Concept and Context model to design the search strategy. The inclusion criteria encompass randomised controlled trials and quasi-experimental studies focusing on adolescents aged 10–19 years. Various types of interventions, such as micronutrient supplementation, nutrition education, feeding interventions, physical activity and community environment interventions, will be considered. Two reviewers will perform data extraction independently, and, where relevant, risk of bias assessment will be conducted using standard Cochrane risk-of-bias tools. We will follow the PRISMA Extension for Scoping Reviews checklist while reporting results.Ethics and dissemination The scope of this scoping review is restricted to publicly accessible databases that do not require prior ethical approval for access. The findings of this review will be shared through publications in peer-reviewed journals, and presentations at international and regional conferences and stakeholder meetings in LMICs.Scoping review registration The final protocol was registered prospectively with the Open Science Framework on 19 July 2023 (https://osf.io/t2d78).

Background. Patterns of SARS‐CoV‐2 spread have varied by geolocation, with differences in seroprevalence between urban and rural areas, and between waves. Household spread of SARS‐CoV‐2 is a known source of new COVID‐19 infections, with rural areas in sub‐Saharan Africa being more prone than urban areas to COVID‐19 transmission because of limited access to water in some areas, delayed health‐ seeking behaviour and poor access to care. Objectives. To explore SARS‐CoV‐2 infection incidence and transmission in rural households in South Africa (SA). Methods. We conducted a prospective household cluster investigation between 13 April and 21 July 2021 in the Matjhabeng subdistrict, a rural area in Free State Province, SA. Adults with SARS‐CoV‐2 confirmed by polymerase chain reaction (PCR) tests (index cases, ICs) and their household contacts (HCs) were enrolled. Household visits conducted at enrolment and on days 7, 14 and 28 included interviewer‐ administered questionnaires and respiratory and blood sample collection for SARS‐CoV‐2 PCR and SARS‐CoV‐2 immunoglobulin G serological testing, respectively. Co‐primary cases were HCs with a positive SARS‐CoV‐2 PCR test at enrolment. The incidence rate (IR), using the Poisson distribution, was HCs with a new positive PCR and/or serological test per 1 000 person‐days. Associations between outcomes and HC characteristics were adjusted for intra‐cluster correlation using robust standard errors. The secondary infection rate (SIR) was the proportion of new COVID‐19 infections among susceptible HCs. Results. Among 23 ICs and 83 HCs enrolled, 10 SARS‐CoV‐2 incident cases were identified, giving an IR of 5.8 per 1 000 person‐days (95% confidence interval (CI) 3.14 ‐ 11.95). Households with a co‐primary case had higher IRs than households without a co‐primary case (crude IR 14.16 v. 1.75, respectively; p=0.054). HIV infection, obesity and the presence of chronic conditions did not materially alter the crude IR. The SIR was 15.9% (95% CI 7.90 ‐ 29.32). Households with a lower household density (fewer household members per bedroom) had a higher IR (IR 9.58; 95% CI 4.67 ‐ 21.71) than households with a higher density (IR 3.06; 95% CI 1.00 ‐ 12.35). Conclusion. We found a high SARS‐CoV‐2 infection rate among HCs in a rural setting, with 48% of households having a co‐primary case at the time of enrolment. Households with co‐primary cases were associated with a higher seroprevalence and incidence of SARS‐CoV‐2. Sociodemographic and health characteristics were not associated with SARS‐CoV‐2 transmission in this study, and we did not identify any transmission risks inherent to a rural setting.

Background. The worldwide distribution and occurrence show that more than 1.8 billion people, accounting for 28% of the global population, are infected with A. lumbricoides infection due to poor hygiene. The World Health Organization aims to eliminate morbidity from A. lumbricoides infection in children by 2030 by at least 75%. Surveys in the Pwani Region of Tanzania have shown poor hygienic risk factors due to high population and lack of sufficient toilets/latrines, poor sewage waste disposal, and insufficient clean drinking water that encourages the reproduction, transmission, and reinfection of A. lumbricoides. No study has been conducted in Pwani Region to determine the extent of A. lumbricoides infection among the population. This research tends to explore more about the status of A. lumbricoides infection in Kibaha District in the Pwani Region, Tanzania. Methods. A cross-sectional study was done on 400 children (170 males and 230 females) who were under the age of 5 years old at Kongowe Health Centre. Collected data for A. lumbricoides infection measured were analyzed using Microsoft Excel, while data for sociodemographic findings and risk assessment were subjected to bivariate and multivariable analysis using Statistical Package for Social Sciences version 28.0.1.0 software (SPSS Inc., USA) at the level of significance of P

Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polymers that are produced by microorganisms as storage materials under limited nutrition and excess carbon. These PHAs have been found to be ideal for replacing synthetic plastics for use in packaging and biomedical applications. In this study, an alkaliphilic and moderately halophilic bacterium Halomonas alkalicola Ext was isolated from Lake Simbi Nyaima in western Kenya and investigated for PHA production. Sudan Black B and Nile Red A staining showed that bacterium had distinct ability for accumulation of PHAs. To optimize PHA production, the bacterium was grown in submerged fermentation under varying culture conditions and different sources and concentrations of carbon and nitrogen. With one-factor-at-a-time (OFTA) approach, optimal PHA yields were obtained after 72 hours at a pH of 10.0, temperature of 35°C, and 2.5% (w/v) NaCl. The bacterium yielded the highest biomass, and PHA amounts on 2% galactose and 0.1% ammonium sulfate as sources of carbon and nitrogen, respectively. A record PHA yield of 0.071 g g-1 with a titer of 1.419±0.09 g/L was achieved from 3.397 g/L of biomass, equivalent to 41.8% PHA content. Using response surface methodology, PHA titer was increased by 1.5% to 1.44 g/L, while PHA content was improved 1.1-fold to 45.57%. Polymer analysis revealed that the extracted PHA was a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) (3−HB:3−HV=92:8) with two copolymer subunits of 3-hydroxyvaryrate (3-HB) and 3-hydroxybutyrate (3-HV). Halomonas alkalicola Ext attained efficient galactose conversion into PHBV under high salinity and alkalinity conditions.