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Submarine sinkholes are found on carbonate platforms around the world. They are thought to form and grow when groundwater interactions generate conditions corrosive to carbonate minerals. Because their morphology can restrict mixing and water exchange, the effects of biogeochemical processes can accumulate such that the sinkhole water properties considerably diverge from the surrounding ocean. Studies of sinkhole waters can therefore reveal new insights into marine biogeochemical cycles, thus sinkholes can be considered as 'natural laboratories' where the response of marine ecosystems to environmental variations can be investigated. We conducted the first measurements in recently discovered sinkholes on Luymes Bank, part of Saba Bank in the Caribbean Netherlands. Our measurements revealed a plume of gas bubbles rising from the seafloor in one of the sinkholes, which contained a constrained body of dense, low-oxygen ([O2] = 60.2 ± 2.6 µmol⋅kg-1), acidic (pHT = 6.24 ± 0.01) seawater that we term the 'acid lake'. Here, we investigate the physical and biogeochemical processes that gave rise to and sustain the acid lake, the chemistry of which is dominated by the bubble plume. We determine the provenance and fate of the acid lake's waters, which we deduce must be continuously flowing through. We show that the acid lake is actively dissolving the carbonate platform, so the bubble plume may provide a novel mechanism for submarine sinkhole formation and growth. It is likely that the bubble plume is ephemeral and that other currently non-acidic sinkholes on Luymes Bank have previously experienced 'acid lake' phases. Conditions within the acid lake are too extreme to represent coming environmental change on human timescales but in some respects reflect the bulk ocean billions of years ago. Other Luymes Bank sinkholes host conditions analogous to projections for the end of the 21st century and could provide a venue for studies on the impacts of anthropogenic CO[sub 2] uptake by the ocean. [ABSTRACT FROM AUTHOR]

The East African Rift System (EARS) exerted a major influence on river drainage basins and regional climate of east Africa during the Cenozoic. Recent studies have highlighted an offshore branch of the EARS in the western Indian Ocean, where the Kerimbas Graben and the Davie Ridge represent its sea floor expression. To date, a clear picture of the impact and timing of this EARS offshore branch on the continental margin of the western Indian Ocean, and associated sediment dispersal pathways, is still missing. This study presents new evidence for four giant canyons along the northern portion of the Davie Ridge offshore Tanzania. Seismic and multibeam bathymetric data highlight that the southernmost three canyons are now inactive, supra‐elevated relative to the adjacent sea floor of the Kerimbas Graben and disconnected from the modern slope systems offshore the Rovuma and Rufiji River deltas. Regional correlation of dated seismic horizons, integrated with well data and sediment samples, proves that the tectonic activity driving the uplift of the Davie Ridge in this area has started during the middle‐upper Miocene and is still ongoing, as suggested by the presence of fault escarpments at the sea floor and by the location and magnitude of recent earthquakes. Our findings contribute to placing the Kerimbas Graben and the Davie Ridge offshore Tanzania in the regional geodynamic context of the western Indian Ocean and show how the tectonics of the offshore branch of the EARS modified the physiography of the margin, re‐routing the deep‐water drainage network since the middle Miocene. Future studies are needed to understand the influence of changing sea floor topography on the western Indian Ocean circulation and to evaluate the potential of the EARS offshore tectonics in generating tsunamigenic events. [ABSTRACT FROM AUTHOR]

U-series age patterns obtained on reef framework-forming cold-water corals collected over a nearly 6000-km-long continental margin sector, extending from off Mauritania (17°N; northwest Africa) to the southwestern Barents Sea (70°N; northeastern Europe), reveal strong climate influences on the geographical distribution and sustained development of these ecosystems. Over the past three glacial-interglacial cycles, framework-forming cold-water corals (Lophelia pertusa and Madrepora oculata) seem to have predominantly populated reefs, canyons, and patches in the temperate East Atlantic and the Mediterranean Sea. Above 50°N corals colonize reefs in the northern East Atlantic primarily during warm climate periods with the biogeographic limit advancing from ~50°N to ~70°N. We propose that north-south oscillations of the biogeographic limit of reef developments are paced by ice ages and may occur synchronously with north-south displacement of cold nutrient-rich intermediate waters and surface productivity related to changes of the polar front. [ABSTRACT FROM AUTHOR]

Objective: Individuals with cancer experience the impact of chemotherapy on hair loss in different ways. The aim of this pilot study was to explore patients' experiences of alopecia through patients' drawings., Methods: Fifteen female patients diagnosed with cancer and treated with chemotherapy were recruited at the oncological day-care unit of a teaching hospital in the Netherlands. Participants completed a semi-structured interview about alopecia. They drew their head and hair before and during chemotherapy and completed the Brief Illness Perception Questionnaire (B-IPQ)., Results: The drawings revealed predominantly physical effects, rather than emotions. Emotions were evident in the text that patients wrote under the drawings and in the B-IPQ open question about the perceived consequences of alopecia. The overall impact of alopecia that emerged from the drawings and the B-IPQ corresponded to the information retrieved from the interviews, namely disappointment, insecurity, sadness, and confrontation., Conclusions: Drawings expose cognitive and emotional responses to alopecia that may be relatively unexplored when using traditional assessment methods such as questionnaires or interviews. In future research, the drawing instructions need to be more specifically focused on feelings in order to better capture emotional reactions to hair loss., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Ann & Joshua Medical Publishing Co. Ltd.)