Socio-environmental impacts of diamond mining areas in the Democratic Republic of Congo.

The mining industry of the Democratic Republic of the Congo (DRC) represents the most important sector of the country's economy, and the DRC belongs to the world top five diamond producers. Artisanal small-scale mining (ASM) of alluvial diamonds represents an important source of alternative income for subsistence farmers, but it also leads to several socio-environmental impacts: deforestation, river pollution, water resources exploitation, unhealthy, unregulated and sometimes dangerous work environments. We perform a data-driven comprehensive analysis of the impact of the diamond mining industry on natural resources and assess the potential relevance of these resources to the DRC food system. To this end, we evaluate land and water resources consumption associated with diamond mining from 2001 to 2018, cross-referencing high-resolution data on mines, land use and tree cover, and using a dynamic and spatially distributed agro-hydrological model. We leverage disaggregated agrological data to provide alternative resources allocation scenarios, and use subnational development indicators and spatially explicit conflict data to frame our analysis within the socio-economic context. We find that, despite the richness in natural resources of the DRC, the impact of diamond mining is relevant because of its effects on ecology, economy, and society. Resources and efforts currently put into the mining industry may have the potential to alleviate the malnourishment crisis in DRC if diverted towards the construction of a more structured and resilient food system. Phenomena such as the illicit trafficking of diamonds and their use to finance wars contribute to nullify the potential of mining as an alternative source of income for subsistence farmers.

Restoration of biogeomorphic systems by creating windows of opportunity to support natural establishment processes.

In degraded landscapes, recolonization by pioneer vegetation is often halted by the presence of persistent environmental stress. When natural expansion does occur, it is commonly due to the momentary alleviation of a key environmental variable previously limiting new growth. Thus, studying the circumstances in which expansion occurs can inspire new restoration techniques, wherein vegetation establishment is provoked by emulating natural events through artificial means. Using the salt-marsh pioneer zone on tidal flats as a biogeomorphic model system, we explore how locally raised sediment bed forms, which are the result of natural (bio)geomorphic processes, enhance seedling establishment in an observational study. We then conduct a manipulative experiment designed to emulate these facilitative conditions in order to enable establishment on an uncolonized tidal flat. Here, we attempt to generate raised growth-promoting sediment bed forms using porous artificial structures. Flume experiments demonstrate how these structures produce a sheltered hydrodynamic environment in which suspended sediment and seeds preferentially settle. The application of these structures in the field led to the formation of stable, raised sediment platforms and the spontaneous recruitment of salt-marsh pioneers in the following growing season. These recruits were composed primarily of the annual pioneering Salicornia genus, with densities of up to 140 individuals/m2 within the structures, a 60-fold increase over ambient densities. Lower abundances of five other perennial species were found within structures that did not appear elsewhere in the pioneer zone. Furthermore, recruits grew to be on average three times greater in mass inside of the structures than in the neighboring ambient environment. The success of this restoration design may be attributed to the combination of three factors: (1) enhanced seed retention, (2) suppressed mortality, and (3) accelerated growth rates on the elevated surfaces generated by the artificial structures. We argue that restoration approaches similar to the one shown here, wherein the conditions for natural establishment are actively mimicked to promote vegetation development, may serve as promising tools in many biogeomorphic ecosystems, ranging from coastal to arid ecosystems.

An approach to the histomorphological and histochemical variations of the humerus cortical bone through human ontogeny.

For many years, clinical and non-clinical investigations have investigated cortical bone structure in an attempt to address questions related to normal bone development, mineralisation, pathologies and even evolutionary trends in our lineage (adaptations). Research in the fields of medicine, materials science, physical anthropology, palaeontology, and even archaeobiology has contributed interesting data. However, many questions remain regarding the histomorphological and histochemical variations in human cortical bone during different stages of life. In the present work, we describe a study of long bone cortex transformations during ontogeny. We analysed cross-sections of 15 human humeri histomorphologically and histochemically from perinatal to adult age, marking and quantifying the spatial distribution of bone tissue types using GIS software and analysing the mineral composition and crystallinity of the mineralised cortex using Raman spectroscopy and X-ray diffraction. Our results allowed us to propose that human cortical bone undergoes three main 'events' through ontogeny that critically change the proportions and structure of the cortex. In early development, bone is not well mineralised and proportionally presents a wide cortex that narrows through the end of childhood. Before reaching complete maturity, the bone mineral area increases, allowing the bone to nearly reach the adult size. The medullary cavity is reduced, and the mineral areas have a highly ordered crystalline structure. The last event occurs in adulthood, when the 'oldest' individuals present a reduced mineralised area, with increasing non-mineralised cavities (including the medullary cavity) and reduced crystalline organisation.