RESUMO
Classical mechanisms of volcanic eruptions mostly involve pressure buildup and magma ascent towards the surface1. Such processes produce geophysical and geochemical signals that may be detected and interpreted as eruption precursors1-3. On 22 May 2021, Mount Nyiragongo (Democratic Republic of the Congo), an open-vent volcano with a persistent lava lake perched within its summit crater, shook up this interpretation by producing an approximately six-hour-long flank eruption without apparent precursors, followed-rather than preceded-by lateral magma motion into the crust. Here we show that this reversed sequence was most likely initiated by a rupture of the edifice, producing deadly lava flows and triggering a voluminous 25-km-long dyke intrusion. The dyke propagated southwards at very shallow depth (less than 500 m) underneath the cities of Goma (Democratic Republic of the Congo) and Gisenyi (Rwanda), as well as Lake Kivu. This volcanic crisis raises new questions about the mechanisms controlling such eruptions and the possibility of facing substantially more hazardous events, such as effusions within densely urbanized areas, phreato-magmatism or a limnic eruption from the gas-rich Lake Kivu. It also more generally highlights the challenges faced with open-vent volcanoes for monitoring, early detection and risk management when a significant volume of magma is stored close to the surface.
RESUMO
OBJECTIVE: This study investigated the reliability and validity of a chronic care facility adaptation of the Clinical Dementia Rating scale (CDR-CC). METHOD: Sixty-two residents in a chronic care facility participated in an inter-rater and 1 month test-retest reliability study. The instrument was validated against the Mini-Mental State Examination (MMSE). RESULTS: Inter-rater and 1 month test-retest reliability for the global CDR-CC score were excellent (intraclass correlation coefficients 0.99 and 0.92, respectively). The CDR-CC domain and global scores were negatively correlated with the MMSE. CONCLUSIONS: The CDR-CC is a global assessment tool that reliably and validly measures cognitive and functional impairment in a chronic care setting.