Few data on iodine status in Somalia are available, but it is assumed that deficiency is a public health problem due to the limited access to iodized salt. We aimed to describe the iodine status of the population of Somalia and to investigate possible determinants of iodine status. A national 2-stage, stratified household cluster survey was conducted in 2009 in the Northwest, Northeast, and South Central Zones of Somalia. Urinary iodine concentration (UIC) was determined in samples from women (aged 15–45 y) and children (aged 6–11 y), and examination for visible goiter was performed in the Northwest and South Central strata. A 24-h household food-frequency questionnaire was conducted, and salt samples were tested for iodization. The median UICs for nonpregnant women and children were 329 and 416 μg/L, respectively, indicating excessive iodine intake (>300 μg/L). The prevalence of visible goiter was <4%. The coverage of salt iodization was low, with a national average of 7.7% (95% CI: 3.2%, 17.4%). Spatial analysis revealed localized areas of relatively high and low iodine status. Variations could not be explained by food consumption or salt iodization but were associated with the main source of household drinking water, with consumers of borehole water having a higher UIC (569 vs. 385 μg/L; P < 0.001). Iodine intake in Somalia is among the highest in the world and excessive according to WHO criteria. Further work is required to investigate the geochemistry and safety of groundwater sources in Somalia and the impact on human nutrition and health.

Aim To develop a new modelling approach for spatially autocorrelated nonnormal data, and apply it to a case study of the role that fire-vegetation-soil feedbacks play in maintaining boundaries between fire-sensitive and firepromoted plant communities.Location A mulga (Acacia aneura) shrubland-spinifex (Triodia spp.) grassland mosaic, central Australia.Methods Autoregressive error models were extended to non-normal data by incorporating neighbourhood values of the response and predictor variables into generalized nonlinear models. These models were used to examine the environmental correlates of three response variables: mulga cover; fire frequency in areas free of mulga; and the presence of mulga banding. Mulga cover and mulga banding were assessed visually by overlaying 4477 · 1 km 2 grid cells on both Landsat 7 ETM+ and very high resolution imagery. Fire frequency was estimated from an existing fire history for central Australia, based on remotely sensed fire scars. ResultsThe autoregressive error models explained 27%, 47% and 57% of the null deviance of mulga cover, fire frequency and mulga banding, respectively, with 12%, 15% and 24% of the null deviance being explained by environmental variables alone. These models accounted for virtually all residual spatial autocorrelation. While there was a clear negative relationship between mulga cover and fire frequency, there was little evidence that mulga was being restricted to parts of the landscape with inherently low fire frequencies. Mulga was most abundant at very low slope angles and on red earths, both of which are likely to reflect high site productivity, while fire frequency was not clearly affected by slope angle and was also relatively high on red earths. Main conclusionsThe modelling approach we have developed provides a much needed way of analysing spatially autocorrelated non-normal data and can be easily incorporated into an information-theoretic modelling framework. Using this approach, we provide evidence that mulga and spinifex have a highly antagonistic relationship. In more productive parts of the landscape, mulga suppresses spinifex and fire, while in less productive parts of the landscape, fire and spinifex suppress mulga, leading to the remarkable abruptness of mulgaspinifex boundaries that are maintained via fire-vegetation-soil feedbacks.

Scouring of piers and abutment has been recognized as the main cause of damage and failure of bridges over waterways. The scientific community has produced a number of studies addressing the complex characteristics of the scour process and has provided engineers with several techniques for the estimate of the maximum expected scour depth at a bridge site. Nevertheless, the prediction of scour depths is affected by many sources of uncertainty, such as observation uncertainty, parameter uncertainty, and structural uncertainty. Only a few studies have recently tried to estimate the uncertainty associated to the scour depth prediction. This paper offers a broad review of the main aspects to be taken into account when analyzing bridge pier scour: 1) processes: to better understand the dynamics triggering pier scour, an analysis of the type of scour occurring at bridge piers, the most influencing factors, failure mechanisms and local pier scour dynamics is carried out; 2) measurements: one of the main difficulties faced in the real world practice is scour data collection; this session reviews the latest techniques available for the measurements of the scour depth at bridge piers; 3) estimates: this session critically reviews different approaches the scientific literature has offered for the estimate of the maximum local scour depth and discusses the difficulty to address uncertainty in the estimates. This review is meant to be a useful reference for scientists and technicians dealing with the bridge pier scour issue.

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Humans reshape wetlandsUnveiling the last 100years of morphological changes of the Mara Wetland, Tanzania