Background: Selective attention is a fundamental cognitive mechanism that allows people to prioritise task-relevant information while ignoring irrelevant information. Previous research has suggested key roles of parietal event-related potentials (ERPs) and alpha oscillatory responses in attention tasks. However, the informational content of these signals is less clear, and their causal effects on the coding of multiple task elements are yet unresolved.
View Article and Find Full Text PDFObjectives: Migration is associated with increased risk of HIV infection in Africa, but evidence about non-HIV sexually transmitted infection (STI) burden among African migrants is limited.
Methods: We used data from the Sexually Transmitted Infection Prevalence Study, a cross-sectional population-based study of chlamydia, gonorrhoea, trichomoniasis, syphilis and herpes simplex virus type 2 prevalence in southern Uganda, to compare STI prevalence between adults aged 18 and 49 years with and without a recent history of migration. Migration status was determined using household census data, with a recent migration history defined as having moved into one's community of current residence within the last ~18 months.
HIV incidence in eastern and southern Africa has historically been concentrated among girls and women aged 15-24 years. As new cases decline with HIV interventions, population-level infection dynamics may shift by age and gender. Here, we integrated population-based surveillance of 38,749 participants in the Rakai Community Cohort Study and longitudinal deep-sequence viral phylogenetics to assess how HIV incidence and population groups driving transmission have changed from 2003 to 2018 in Uganda.
View Article and Find Full Text PDFFishing communities around Lake Victoria have among the highest burdens of HIV globally. Growing evidence suggests that high HIV prevalence is partially due to selective migration of people living with HIV to fishing communities. However, the reasons for this preferential migration are unclear.
View Article and Find Full Text PDFLong-acting injectable antiretroviral treatment (LAI ART), such as a bimonthly injection of cabotegravir/rilpivirine, is a promising HIV treatment option. LAI ART may particularly benefit people who are reluctant to initiate or are poorly adherent to daily oral pills and not virally suppressed. However, the acceptability and feasibility of LAI ART among individuals with viremia in Africa has not been well studied.
View Article and Find Full Text PDFUnderstanding treatment-seeking behavior is critical to the treatment and control of sexually transmitted infections (STIs), yet current data on STI treatment seeking in low-resource settings is rare. This population-based study aimed to describe STI treatment-seeking behavior and identify factors associated with seeking treatment at a clinic among adults with STI-related symptoms in rural Uganda. The STI prevalence study (STIPS) conducted a survey and STI testing among all consenting adults aged 18-49 in two communities in rural south-central Uganda.
View Article and Find Full Text PDFBackground: Herpes simplex virus type 2 (HSV-2) is an incurable sexually transmitted infection associated with increased risk of acquiring and transmitting human immunodeficiency virus (HIV). HSV-2 is highly prevalent in sub-Saharan Africa, but population-level estimates of incidence are sparse.
Methods: We measured HSV-2 prevalence from cross-sectional serological data among adults aged 18-49 years in 2 south-central Uganda communities (fishing, inland).
HIV incidence in eastern and southern Africa has historically been concentrated among girls and women aged 15-24 years. As new cases decline with HIV interventions, population-level infection dynamics may shift by age and gender. Here, we integrated population-based surveillance of 38,749 participants in the Rakai Community Cohort Study and longitudinal deep sequence viral phylogenetics to assess how HIV incidence and population groups driving transmission have changed from 2003 to 2018 in Uganda.
View Article and Find Full Text PDFLancet Glob Health
December 2022
Background: Combination HIV prevention and treatment interventions (CHIs) have led to substantial declines in HIV incidence in sub-Saharan Africa; however, population-level data on non-HIV sexually transmitted infections (STIs) in the context of CHIs are rare. We aimed to assess STI burden following scale-up of CHIs in Uganda.
Methods: The Sexually Transmitted Infection Prevalence Study (STIPS) was a cross-sectional study nested within a population-based cohort among inland agrarian and Lake Victoria fishing populations in southern Uganda.
There is a strict interaction between the autonomic nervous system (ANS) and pain, which might involve descending pain modulatory mechanisms. The periaqueductal grey (PAG) is involved both in descending pain modulation and ANS, but its role in mediating this relationship has not yet been explored. Here, we sought to determine brain regions mediating ANS and descending pain control associations.
View Article and Find Full Text PDFGlutamate signalling is increasingly implicated across a range of psychiatric, neurological and pain disorders. Reliable methodologies are needed to probe the glutamate system and understand glutamate dynamics . Functional magnetic resonance spectroscopy (H-fMRS) is a technique that allows measurement of glutamatergic metabolites over time in response to task conditions including painful stimuli.
View Article and Find Full Text PDFUganda piloted HIV pre-exposure prophylaxis (PrEP) for priority populations (sex workers, fishermen, truck drivers, discordant couples) in 2017. To assess facilitators and barriers to PrEP uptake and adherence, we explored perceptions of PrEP before and experiences after rollout among community members and providers in south-central Uganda. We conducted 75 in-depth interviews and 12 focus group discussions.
View Article and Find Full Text PDFDorsolateral prefrontal cortex (dlPFC) is proposed to drive brain-wide focus by biasing processing in favour of task-relevant information. A longstanding debate concerns whether this is achieved through enhancing processing of relevant information and/or by inhibiting irrelevant information. To address this, we applied transcranial magnetic stimulation (TMS) during fMRI, and tested for causal changes in information coding.
View Article and Find Full Text PDFThere are bi-directional interactions between the autonomic nervous system (ANS) and pain. This is likely underpinned by a substantial overlap between brain areas of the central autonomic network and areas involved in pain processing and modulation. To date, however, relatively little is known about the neuronal substrates of the ANS-pain association.
View Article and Find Full Text PDFFunctional neuroimaging techniques have provided great insight in the field of pain. Utilising these techniques, we have characterised pain-induced responses in the brain and improved our understanding of key pain-related phenomena. Despite the utility of these methods, there remains a need to assess the test retest reliability of pain modulated blood-oxygen-level-dependant (BOLD) MR signal across repeated sessions.
View Article and Find Full Text PDFBackground: Functional connectivity (FC) perturbations have been reported in multiple chronic pain phenotypes, but the nature of reported changes varies between cohorts and may relate to the consequences of living with chronic-pain related comorbidities, such as anxiety and depression. Healthy volunteer studies provide opportunities to study the effects of tonic noxious stimulation independently of these sequelae. Connectivity changes in task negative and positive networks, for example, the default mode and salience networks (DMN/SN), respectively, have been described, but how these and other connectivity networks, for example, those governing descending pain control are affected by the presence of tonic, noxious stimulation in healthy, pain-free individuals, remains unknown.
View Article and Find Full Text PDFOur ability to flexibly switch between different tasks is a key component of cognitive control. Non-human primate (NHP) studies (e.g.
View Article and Find Full Text PDFMultivariate pattern analysis of functional magnetic resonance imaging (fMRI) data is widely used, yet the spatial scales and origin of neurovascular signals underlying such analyses remain unclear. We compared decoding performance for stimulus orientation and eye of origin from fMRI measurements in human visual cortex with predictions based on the columnar organization of each feature and estimated the spatial scales of patterns driving decoding. Both orientation and eye of origin could be decoded significantly above chance in early visual areas (V1-V3).
View Article and Find Full Text PDFHuman cognition is characterized by astounding flexibility, enabling us to select appropriate information according to the objectives of our current task. A circuit of frontal and parietal brain regions, often referred to as the frontoparietal attention network or multiple-demand (MD) regions, are believed to play a fundamental role in this flexibility. There is evidence that these regions dynamically adjust their responses to selectively process information that is currently relevant for behavior, as proposed by the "adaptive coding hypothesis" [Duncan, J.
View Article and Find Full Text PDFHow is the processing of task information organized in the brain? Many views of brain function emphasize modularity, with different regions specialized for processing different types of information. However, recent accounts also highlight flexibility, pointing especially to the highly consistent pattern of frontoparietal activation across many tasks. Although early insights from functional imaging were based on overall activation levels during different cognitive operations, in the last decade many researchers have used multivoxel pattern analyses to interrogate the representational content of activations, mapping out the brain regions that make particular stimulus, rule, or response distinctions.
View Article and Find Full Text PDFIn neurosecretory cells, secretory vesicles (SVs) undergo Ca(2+)-dependent fusion with the plasma membrane to release neurotransmitters. How SVs cross the dense mesh of the cortical actin network to reach the plasma membrane remains unclear. Here we reveal that, in bovine chromaffin cells, SVs embedded in the cortical actin network undergo a highly synchronized transition towards the plasma membrane and Munc18-1-dependent docking in response to secretagogues.
View Article and Find Full Text PDFBackground: It has been suggested that there is an increased morbidity and mortality risk for diabetics undergoing elective aortic surgery. This, however, is not universally accepted. In this study, we utilize a national database to determine if diabetes is associated with adverse outcomes following open, elective, infrarenal abdominal aortic aneurysm (AAA) repair.
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