Gone with the Wind: Microbial Communities Associated with Dust from Emissive Farmlands.

Dust is a major vehicle for the dispersal of microorganisms across the globe. While much attention has been focused on microbial dispersal in dust plumes from major natural dust sources, very little is known about the fractionation processes that select for the "dust microbiome." The recent identification of highly emissive, agricultural land dust sources in South Africa has provided the opportunity to study the displacement of microbial communities through dust generation and transport. In this study, we aimed to document the microbial communities that are carried in the dust from one of South Africa's most emissive locations, and to investigate the selective factors that control the partitioning of microbial communities from soil to dust. For this purpose, dust samples were generated at different emission sources using a Portable In-Situ Wind Erosion Lab (PI-SWERL), and the taxonomic composition of the resulting microbiomes was compared with the source soils. Dust emission processes resulted in the clear fractionation of the soil bacterial community, where dust samples were significantly enriched in spore-forming taxa. Conversely, little fractionation was observed in the soil fungal communities, such that the dust fungal fingerprint could be used to identify the source soil. Dust microbiomes were also found to vary according to the emission source, suggesting that land use significantly affected the structure and fractionation of microbial communities transported in dust plumes. In addition, several potential biological allergens of fungal origin were detected in the dust microbiomes, highlighting the potential detrimental effects of dust plumes emitted in South Africa. This study represents the first description of the fractionation of microbial taxa occurring at the source of dust plumes and provides a direct link between land use and its impact on the dust microbiome.

Neighbourhood residential density and childhood obesity.

Residential density is considered an important attribute of the built environment that may be relevant to childhood obesity. However, findings remain inconclusive, and there are no reviews yet on the association between residential density and childhood obesity. This study aimed to systematically review the associations between residential density and weight-related behaviours and outcomes. A comprehensive literature search was conducted using the Cochrane Library, PubMed and Web of Science for articles published before 1 January 2019. A total of 35 studies conducted in 14 countries were identified, including 33 cross-sectional studies, one longitudinal study and one containing both study designs. Residential density was measured by Geographic Information Systems in 28 studies within a varied radius from 0.25 to 2 km around the individual residence. Our study found a general positive association between residential density and physical activity (PA); no significant associations were observed. This study provided evidence for a supportive role of residential density in promoting PA among children. However, it remained difficult to draw a conclusion between residential density and childhood obesity. Future longitudinal studies are warranted to confirm this association.

Association between neighborhood aesthetics and childhood obesity.

The lack of neighbourhood aesthetics (e.g. public art and well-maintained properties) may reduce walkability in the neighbourhood and increase the risk of childhood obesity. In this study, a literature search was conducted in the Cochrane Library, PubMed and Web of Science for articles published before January 1, 2019 to analyse the associations between neighbourhood aesthetics and weight-related behaviours and outcomes among children and adolescents aged <18. One cohort study and 24 cross-sectional studies, conducted in 10 countries with a median sample size of 1124 were identified. Neighbourhood aesthetics was more commonly assessed by self-reported or parent-reported perceptions than objective measurements. Eighteen of the 25 included studies analysed physical activity (PA) as the outcome of interests, eight studies analysed active transport to school (ATS), and eight studies analysed weight status, including body mass index and overweight/obesity status. About two-thirds of studies reported non-significant associations when using PA and weight status as outcomes, and half of studies showed that neighbourhood aesthetics is associated with increased use of ATS. The rest of the studies reported mixed findings with slightly more studies showing neighbourhood aesthetics may promote PA or reduce weight. Better designed studies are necessary to achieve a robust understanding of this epidemiological relationship in the future.

Neighbourhood speed limit and childhood obesity.

As an important factor for neighbourhood walkability, the speed limit in the neighbourhood may influence children's physical activity (PA) outdoors, especially active transport, and further their weight status. This review aimed to systematically evaluate the association between neighbourhood speed limit and obesity-related behaviours and outcomes among children and adolescents. PubMed, Embase and Web of Science were systematically searched for relevant studies published from the inception of the database to 1 January 2019. Sixteen studies were included, with 13 cross-sectional studies and three longitudinal studies. Speed limit was measured as the percentage/number of high-speed roads, perception of safe driving speed, perception of speeding and use of traffic-calming tools in the neighbourhood. Eleven studies measured the use of active transport as the outcome of interest, and seven studies measured PA directly. Eleven studies revealed an association between a lower speed limit and increased PA, whereas one study showed a negative association, and three studies reported non-significant associations. Only one study associated speed limit with weight status, which reported a non-significant association. This review generally supported a negative association between speed limit and PA among children and adolescents. More studies are needed to examine their causality, as well as the association between speed limit and weight status, in order to increase the impact of this research area on public health policy making.

Hyperkeratosis lenticularis perstans (Flegel's disease) - successful treatment with topical corticosteroids.

Flegel's disease, also known as hyperkeratosis lenticularis perstans, is a rare skin disease characterized by small, red-brown, hyperkeratotic, papules that are usually located on the lower extremities. The diagnosis is based on the clinical appearance in association with the typical histologic features of orthohyperkeratosis and a subepidermal band-like infiltrate. Treatment is difficult and rarely fully effective. We report on a woman with Flegel's disease who responded to a topical corticosteroid therapy with betamethasone dipropionate.

Ossification of the auricle.

The auricle is a flexible structure because it is formed by elastic cartilage. In the rare occurrence of ectopic auricular ossification, however, the cartilage is replaced by lamellar bone and becomes petrified. Such unphysiological replacement has been reported in association with local trauma, inflammation, systemic diseases, and hypothermia. Here, we report a patient with unilateral ossification of the auricle secondary to frostbite.