Carbon with depleted dC (down to - 25.6‰ VPDB) found in > 3.7 billion year old metamorphic sediments from the Isua Supracrustal Belt, Southwestern Greenland, has been proposed to represent the oldest remains of life on Earth.
View Article and Find Full Text PDFBackground: The event of extradural hematoma in the absence of head trauma is a rare central nervous system complication of sickle cell disease. We report here a case of spontaneous extradural hematoma in a patient being treated for sickle cell vasoocclusive crisis complicated by hyperinflammation and thrombotic microangiopathy. The significance of inflammation as an integral component of the pathomechanism of vasoocclusive crisis in patients with sickle cell disease and the role of heme in activating the complement system's alternative pathway are highlighted in this case report.
View Article and Find Full Text PDFIn all organisms with circadian clocks, post-translational modifications of clock proteins control the dynamics of circadian rhythms, with phosphorylation playing a dominant role. All major clock proteins are highly phosphorylated, and many kinases have been described to be responsible. In contrast, it is largely unclear whether and to what extent their counterparts, the phosphatases, play an equally crucial role.
View Article and Find Full Text PDFMetasedimentary rocks from Isua, West Greenland (> 3,700 million years old) contain carbonaceous compounds, compatible with a biogenic origin (Hassenkam, Andersson, Dalby, Mackenzie, & Rosing, 2017; Ohtomo, Kakegawa, Ishida, Nagase, & Rosing, 2014; Rosing, 1999). The metamorphic mineral assemblage with garnet and quartz intergrowths contains layers of carbonaceous inclusions contiguous with carbon-rich sedimentary beds in the host rock. Previous studies (Hassenkam et al.
View Article and Find Full Text PDFMountain regions are unusually biodiverse, with rich aggregations of small-ranged species that form centers of endemism. Mountains play an array of roles for Earth's biodiversity and affect neighboring lowlands through biotic interchange, changes in regional climate, and nutrient runoff. The high biodiversity of certain mountains reflects the interplay of multiple evolutionary mechanisms: enhanced speciation rates with distinct opportunities for coexistence and persistence of lineages, shaped by long-term climatic changes interacting with topographically dynamic landscapes.
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