The burden of cognitive impairment appears to increase with progressive renal disease, such that the prevalence of dementia among those starting dialysis, or those already established on dialysis, is high. The appropriateness of dialysis initiation in this population has been questioned, and current Renal Physician Association guidelines suggest forgoing dialysis in individuals who have dementia and lack awareness of self and environment. Patients are, however, also entitled to equal rights and respect, equal access to health care services, and an opportunity to engage in shared decision-making processes, particularly if there is concern over reversibility of disease. This article discusses, on the basis of principles of beneficence and nonmaleficence, the arguments in favor of and against dialysis use, and the process of determining an appropriate care plan. Factors discussed include the current societal trend toward a technological imperative, premature fatalism, survival benefits, and the implications of providing care to patients who are unable to express their tolerance for symptoms associated with the treatment or lack of treatment.

Abundant global oxygen is crucial for macroscopic life on Earth today, yet the tempos and triggers of ancient oxygenation are unknown. Iron formations (originally defined as rocks with >15 wt. % iron; James, 1954) hold important clues to the early evolution of Earth's atmosphere and biosphere, yet questions about their genesis remain. In particular: (a) are all massive iron formations (IFs) deposited in broadly similar depositional and geochemical settings; and (b) what drives their episodic deposition? The purpose of this work is to assess these questions with a case study coupling facies-based sedimentological and stratigraphic approaches for the ∼1.88 Ga Gogebic Range exposed near Lake Superior, USA (Michigan-Wisconsin), one of a few preserved post-Great Oxidation Event (GOE) massive iron deposits.Massive IFs (∼10 6 Gigatons) occur only in the Precambrian (e.g., Bekker et al., 2014;Konhauser et al., 2017). When examining the geologic record, the largest volumes of preserved IFs span the Late Archean to

Abundant global oxygen is crucial for macroscopic life on Earth today, yet the tempos and triggers of ancient oxygenation are unknown. Iron formations (originally defined as rocks with >15 wt. % iron; James, 1954) hold important clues to the early evolution of Earth's atmosphere and biosphere, yet questions about their genesis remain. In particular: (a) are all massive iron formations (IFs) deposited in broadly similar depositional and geochemical settings; and (b) what drives their episodic deposition? The purpose of this work is to assess these questions with a case study coupling facies-based sedimentological and stratigraphic approaches for the ∼1.88 Ga Gogebic Range exposed near Lake Superior, USA (Michigan-Wisconsin), one of a few preserved post-Great Oxidation Event (GOE) massive iron deposits.Massive IFs (∼10 6 Gigatons) occur only in the Precambrian (e.g., Bekker et al., 2014;Konhauser et al., 2017). When examining the geologic record, the largest volumes of preserved IFs span the Late Archean to

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