The Effect of Mask Style and Fabric Selection on the Comfort Properties of Fabric Masks.

The purpose of fabric masks in the prevention of the spread of COVID-19 often requires that the masks be worn for extended periods without removal. The management of the conditions in the micro-climate inside the masks is important to keep the wearer comfortable and enhance user compliance. In this study, the effect of mask design and fabric type on the micro-climate was investigated using thermocron iButtons to record the temperature and humidity inside the masks. It was found that the mask style, and its effect on the amount of air incorporated in the micro-climate, had a significant influence on the factors that determine the temperature and humidity levels. In the shaped masks, the impact of the mask design on the results was stronger than the effect of fabric type. In the folded masks that fit snugly around the face, the effect of fabric type was significant, and both fibre composition and fabric structure contributed to the differences in the performance of the three fabrics tested. In the case of the masks with an inserted filter, a significant amount of trapped still air in the fabric layers and the increased mask stiffness had the strongest effect on the temperature and humidity inside the masks. Significant differences were also found in the temperatures recorded in the different time segments, highlighting the importance of conducting comfort evaluations over a long enough time to prevent false interpretations. The results of this study emphasize the importance of considering all the components of mask design, namely style, fibre type, and fabric structure, in the development of masks to enhance user compliance.

Unmasking the Mask: Investigating the Role of Physical Properties in the Efficacy of Fabric Masks to Prevent the Spread of the COVID-19 Virus.

To function as source control, a fabric mask must be able to filter micro-droplets (≥5 µm) in expiratory secretions and still allow the wearer to breathe normally. This study investigated the effects of fabric structural properties on the filtration efficiency (FE) and air permeability (AP) of a range of textile fabrics, using a new method to measure the filtration of particles in the described conditions. The FE improved significantly when the number of layers increased. The FE of the woven fabrics was generally higher, but double-layer weft knitted fabrics, especially when combined with a third (filter) layer, provided a comparable FE without compromising on breathability. This also confirmed the potential of nonwoven fabrics as filter layers in masks. None of the physical fabric properties studied affected FE significantly more than the others. The variance in results achieved within the sample groups show that the overall performance properties of each textile fabric are a product of its combined physical or structural properties, and assumptions that fabrics which appear to be similar will exhibit the same performance properties cannot be made. The combination of layers of fabric in the design of a mask further contributes to the product performance.

Barriers experienced by people with disabilities participating in income-generating activities. A case of a sheltered workshop in Bloemfontein, South Africa.

BACKGROUND: People with disabilities often participate in income-generating activities (IGAs) in sheltered workshop in South Africa. However, they face many barriers that limit their ability to participate effectively in economic activities hosted by the workshops. OBJECTIVES: To illustrate the barriers that limit the participation of people with disabilities in IGAs in a sheltered workshop. METHOD: A qualitative exploratory single case study was conducted in a sheltered workshop. Eighteen participants, age 22 to 52 years with various disabilities were purposively sampled. Observations and semi-structured interview guides were used to generate data. Verbatim transcription was used after which content analysis was applied to identify ideas and concepts relating to barriers experienced by people with disabilities participating in IGAs. RESULTS: Some of the barriers participants experienced included institutional barriers (ability to use working tools, inability to concentrate for long periods, lack of funds, language barriers, lack of motivation, activities that are not stimulating and lack of artistry skills) and attitudinal barriers (exclusion from decision making) These barriers had an adverse influence on their performance in IGAs. CONCLUSION: The study found eight different barriers that existed in a sheltered workshop which limited the participation of the people with disabilities that attended the workshop. This information can be used to develop strategies to address each barrier and promote increased participation of the individual thereby improving their quality of life.

Endophytic bacteria in toxic South African plants: identification, phylogeny and possible involvement in gousiekte.

BACKGROUND: South African plant species of the genera Fadogia, Pavetta and Vangueria (all belonging to Rubiaceae) are known to cause gousiekte (literally 'quick disease'), a fatal cardiotoxicosis of ruminants characterised by acute heart failure four to eight weeks after ingestion. Noteworthy is that all these plants harbour endophytes in their leaves: nodulating bacteria in specialized nodules in Pavetta and non-nodulating bacteria in the intercellular spaces between mesophyll cells in Fadogia and Vangueria. PRINCIPAL FINDINGS: Isolation and analyses of these endophytes reveal the presence of Burkholderia bacteria in all the plant species implicated in gousiekte. Although the nodulating and non-nodulating bacteria belong to the same genus, they are phylogenetically not closely related and even fall in different bacterial clades. Pavetta harborii and Pavetta schumanniana have their own specific endophyte--Candidatus Burkholderia harborii and Candidatus Burkholderia schumanniana--while the non-nodulating bacteria found in the other gousiekte-inducing plants show high similarity to Burkholderia caledonica. In this group, the bacteria are host specific at population level. Investigation of gousiekte-inducing plants from other African countries resulted in the discovery of the same endophytes. Several other plants of the genera Afrocanthium, Canthium, Keetia, Psydrax, Pygmaeothamnus and Pyrostria were tested and were found to lack bacterial endophytes. CONCLUSIONS: The discovery and identification of Burkholderia bacteria in gousiekte-inducing plants open new perspectives and opportunities for research not only into the cause of this economically important disease, but also into the evolution and functional significance of bacterial endosymbiosis in Rubiaceae. Other South African Rubiaceae that grow in the same area as the gousiekte-inducing plants were found to lack bacterial endophytes which suggests a link between bacteria and gousiekte. The same bacteria are consistently found in gousiekte-inducing plants from different regions indicating that these plants will also be toxic to ruminants in other African countries.