Comparative study of age-dependent susceptibility to the transmissible spongiform encephalopathies

The age distribution of the naturally occurring transmissible spongiform encephalopathies (TSEs) or prion diseases, including scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle and variant Creutzfeldt-Jakob disease in humans (vCJD) may be explained by age-dependent susceptibility to infection. Epidemiological studies have shown that exposure to BSE-contaminated meat and meat products alone cannot fully account for the young age distribution of vCJD cases, and that changes in susceptibility may also play a role. Oral exposure has been implicated as the most likely route of natural transmission of TSEs. Peyer's patches (PPs), part of the gut-associated lymphoid tissue (GALT), may represent a portal of entry for orally transmitted prions and appear to be the most likely sites of prion accumulation in the gastrointestinal tract. The main aim of this project was to determine whether the observed age-susceptibility relationship of scrapie, BSE and vCJD could be explained by the development of PPs in the gut. Statistical analyses were performed on an experimental scrapie dataset to determine whether there was an effect of age at exposure on scrapie outcome and incubation period of the disease, taking into consideration other potentially important factors related to susceptibility. PP tissue was quantified in the distal ileum of NPU Cheviot sheep, and data on measures of PP development in cattle and humans were extracted from previous studies. Anatomical PP data and estimates of age-related risks of infection, derived from mathematical models, were used to determine a potential link between age-related risk of natural TSE infection and the development of PP tissue in the three species. Because follicular dendritic cells (FDCs) have been implicated as the likely sites of prion replication in lymphoid tissues, immunocytochemistry was carried out to investigate the ontogeny of PrP-associated FDCs in ileal PP tissue in both mice and sheep. Results showed that age at exposure to the TSE agent is a potentially important factor in determining disease outcome as well as the incubation period of disease. Younger sheep were found to have shorter incubation periods than older animals following subcutaneous inoculation of the infectious agent, a finding which may be attributed to the development of peripheral nerves and which warrants further investigation. For sheep, cattle and humans, measures of PP development peaked in adolescent years followed by a decline, thereafter. There was a significant correlation between measures of PP development and estimated risks of natural TSE infection, with the two age-related distributions peaking in the same age group for all three species. Immunocytochemistry studies showed that PrP-associated FDCs can first be detected in 7 day-old mice, and provided further evidence for the presence of mature FDC networks in GALT of postnatal sheep. These findings imply that, in the absence of FDCs, mice younger than 7 days old may be less susceptible to oral scrapie challenge. The presence of FDCs in newborn sheep suggests that these animals may be susceptible to TSE infection in early postnatal life particularly at lambing when an infected placenta could act as a source of scrapie infection to the young lamb. Age-dependent susceptibility to oral TSE infection in mice and sheep may offer a convenient experimental framework with which to explore the reasons for age-dependent susceptibility to TSE infection in humans

Apportioned city: gendered delineations of asylum, work and violence in Cape Town

This paper addresses what it means to live with acutely restricted access to the city in the process of seeking urban asylum in post-apartheid South Africa. Our concept of apportionment specifies the gendered and racialised diminishment of space and time in the context of exclusionary and everyday violence. We focus on how the delineation and reduction of space and time is feminised, through the working lives of refugee and asylum-seeking women from the Democratic Republic of the Congo who live in Cape Town. Their embodied experiences incorporate the resonance of war in the Democratic Republic of the Congo, further sharpening their careful movements across Cape Town’s segregated geographies. Drawing on our conversations with non-governmental organisations and self-employed women over a nine-month period in 2020, we highlight how the deferral of refuge compounds precarity, significantly affecting women and those who are sexually minoritised. In connecting how state apportionment maps onto urban apportionment we reveal how an ecology of violence – of spatialised segregation, xenophobia and sexual violence – establishes a corporeal power that constrains access to the city. Crucially, these women deploy counter practices of apportionment and their precisely attuned navigations add to our understanding of the agile repertoires of working the city

Bi-Directional Learning: Identifying Contaminants on the Yurok Indian Reservation.

The Yurok Tribe partnered with the University of California Davis (UC Davis) Superfund Research Program to identify and address contaminants in the Klamath watershed that may be impairing human and ecosystem health. We draw on a community-based participatory research approach that begins with community concerns, includes shared duties across the research process, and collaborative interpretation of results. A primary challenge facing University and Tribal researchers on this project is the complexity of the relationship(s) between the identity and concentrations of contaminants and the diversity of illnesses plaguing community members. The framework of bi-directional learning includes Yurok-led river sampling, Yurok traditional ecological knowledge, University lab analysis, and collaborative interpretation of results. Yurok staff and community members share their unique exposure pathways, their knowledge of the landscape, their past scientific studies, and the history of landscape management, and University researchers use both specific and broad scope chemical screening techniques to attempt to identify contaminants and their sources. Both university and tribal knowledge are crucial to understanding the relationship between human and environmental health. This paper examines University and Tribal researchers' shared learning, progress, and challenges at the end of the second year of a five-year Superfund Research Program (SRP) grant to identify and remediate toxins in the lower Klamath River watershed. Our water quality research is framed within a larger question of how to best build university-Tribal collaboration to address contamination and associated human health impacts

An Introduction to Interprofessional Education for First Semester Doctoral Occupational Therapy and Physical Therapy Students

Purpose: Interprofessional education (IPE) engages health care professional students in order to develop the knowledge, skills, and attitudes required of a health care practitioner. IPE can be challenging to execute; however, exposing students early in their professional education in IPE has positive results. Occupational therapy (OT) and physical therapy (PT) are health care professions who commonly work with each other. The purpose of this study is to describe the process and outcomes of implementing an IPE experience with first year doctoral OT (OTD) and PT (DPT) students completed within the first six weeks of the first semester of their respective programs. Methods: Ninety-one (31 OTD, 60 DPT) students were placed in small groups and discussed professional identities and interprofessional collaboration among OT/PT during pre-professional observations. Students completed the Readiness for Interprofessional Learning Scale (RIPLS) pre-post-meeting and a written reflection post-meeting. Results: Ninety-one students completed the Pre-RIPLS survey, while only 58 Post-RIPLS were completed (13 OTD, 45 DPT). The response rate was 63.7% overall (41.9% OT and 75% PT). A statistically significant difference was found between pre- to post-test RIPLS score among the entire group (p = 0.013), and the DPT students (p = 0.020), but not the OTD students (p = 0.414). Written reflections included the following themes: influence of personal experiences leading to choice of profession, observations shaping knowledge of the professions, similarities and differences between the two professions, and future collaboration. Conclusion: An IPE activity can be implemented early in the professional education of OTD/DPT students with positive results

Field evaluation of two rapid diagnostic tests for Neisseria meningitidis serogroup A during the 2006 outbreak in Niger.

The Pastorex((R)) (BioRad) rapid agglutination test is one of the main rapid diagnostic tests (RDTs) for meningococcal disease currently in use in the "meningitis belt". Earlier evaluations, performed after heating and centrifugation of cerebrospinal fluid (CSF) samples, under good laboratory conditions, showed high sensitivity and specificity. However, during an epidemic, the test may be used without prior sample preparation. Recently a new, easy-to-use dipstick RDT for meningococcal disease detection on CSF was developed by the Centre de Recherche Médicale et Sanitaire in Niger and the Pasteur Institute in France. We estimate diagnostic accuracy in the field during the 2006 outbreak of Neisseria meningitidis serogroup A in Maradi, Niger, for the dipstick RDT and Pastorex((R)) on unprepared CSF, (a) by comparing each test's sensitivity and specificity with previously reported values; and (b) by comparing results for each test on paired samples, using McNemar's test. We also (c) estimate diagnostic accuracy of the dipstick RDT on diluted whole blood. We tested unprepared CSF and diluted whole blood from 126 patients with suspected meningococcal disease presenting at four health posts. (a) Pastorex((R)) sensitivity (69%; 95%CI 57-79) was significantly lower than found previously for prepared CSF samples [87% (81-91); or 88% (85-91)], as was specificity [81% (95%CI 68-91) vs 93% (90-95); or 93% (87-96)]. Sensitivity of the dipstick RDT [89% (95%CI 80-95)] was similar to previously reported values for ideal laboratory conditions [89% (84-93) and 94% (90-96)]. Specificity, at 62% (95%CI 48-75), was significantly lower than found previously [94% (92-96) and 97% (94-99)]. (b) McNemar's test for the dipstick RDT vs Pastorex((R)) was statistically significant (p<0.001). (c) The dipstick RDT did not perform satisfactorily on diluted whole blood (sensitivity 73%; specificity 57%).Sensitivity and specificity of Pastorex((R)) without prior CSF preparation were poorer than previously reported results from prepared samples; therefore we caution against using this test during an epidemic if sample preparation is not possible. For the dipstick RDT, sensitivity was similar to, while specificity was not as high as previously reported during a more stable context. Further studies are needed to evaluate its field performance, especially for different populations and other serogroups

Ultra-processed food consumption in Barbados: evidence from a nationally representative, cross-sectional study.

Our objective was to describe, for the first time in an English-speaking Caribbean country, the contribution of ultra-processed foods (UPFs) to nutrients linked to non-communicable disease. Using a cross-sectional study design, dietary data were collected from two non-consecutive 24-h dietary recalls. Recorded food items were then classified according to their degree of processing by the NOVA system. The present study took place in Barbados (2012-13). A representative population-based sample of 364 adult Barbadians (161 males and 203 females) aged 25-64 years participated in the study. UPFs represented 40⋅5 % (838 kcal/d; 95 % CI 791, 885) of mean energy intake. Sugar-sweetened beverages made the largest contribution to energy within the UPF category. Younger persons (25-44 years) consumed a significantly higher proportion of calories from UPF (NOVA group 4) compared with older persons (45-64 years). The mean energy shares of UPF ranged from 22⋅0 to 58⋅9 % for those in the lowest tertile to highest tertile. Within each tertile, the energy contribution was significantly higher in the younger age group (25-44 years) compared with the older (45-64 years). One-quarter of persons consume ≥50 % of their daily calories from UPF, this being significantly higher in younger persons. The ultra-processed diet fraction contained about six times the mean of free sugars and about 0⋅8 times the dietary fibre of the non-ultra-processed fraction (NOVA groups 1-3). Targeted interventions to decrease the consumption of UPF especially in younger persons is thus of high priority to improve the diet quality of Barbadians.This work was supported by the Ministry of Health and Wellness of the Government of Barbados

Exploring the housing needs of older people in standard and sheltered social housing

Objective: Our home can have a major impact on our physical and mental health; this is particularly true for older people who may spend more time at home. Older people in social (i.e., public) housing are particularly vulnerable. Housing options for older people in social housing include standard design dwellings or specially designed “sheltered housing.” The most suitable housing model should be identified, with older people consulted in this process. Method: Survey of older people (aged ≥60) living in standard or sheltered social housing. Data were analyzed using descriptive and inferential statistics in SPSS Version 22. Results: Overall, 380 surveys were returned (response rate = 47.2%). All older people had similar housing needs. Those in sheltered housing were more satisfied with the physical home design and reported more positive outcomes. Older people in standard housing were less likely to have necessary adaptations to facilitate aging-in-place. Discussion: Older people in standard housing reported more disability/illnesses, are worried about the future, and felt less safe at home. However, few wanted to move, and very few viewed sheltered housing as an alternative, suggesting limited knowledge about their housing options. Future social housing designs should be flexible, that is, adaptable to the needs of the tenants over time