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According to the Association of African American Museums (AAAM), there are more than 200 African American history and cultural museums—or other sites with substantial African American collections such as libraries and archives—across the U.S. Many of these museums had their start shortly after the height of the Civil Rights Movement, with a surge in establishments in the 1970s. Black museums serve to decenter White stories of America and refocus on Black experiences. While geographers have studied an array of memory, heritage, and tourism sites, museums remain understudied and under-theorized. Building upon the subfields of Museum geographies—particularly by considering the concept of museums as theatres of pain—and Black geographies, our research examines the ways these museums are integral to the relationships between Black placemaking and the tourism landscape, which remains steeped in anti-Black racism. Using museum exhibit documentation, semi-structured interviews of museum staff, and content analysis of online travel reviews (primarily TripAdvisor and Google Reviews), this paper analyzes two case studies: The National Afro-American Museum and Cultural Center in Wilberforce, Ohio, and The Colored Girls Museum in Philadelphia, Pennsylvania. Through our two case studies, we show how Black museums enact curatorial practices of commemorative geographies and create redemptive spaces that cultivate not only a homeplace for visitors, particularly for Black Americans and people of the African diaspora but also serve as sites of belonging and joy. 

The formation of highly substituted cyclopentenols was developed using a Claisen−Sakurai reaction. Both elements of the reaction can be performed in a one-pot sequence that provides the corresponding cyclized products in high stereoselectivity. The stereochemical outcome is defined by a combination of Claisen stereospecificity and stereoelectronic effects in the Sakurai cyclization that promotes reactivity via an anti-SE′ antiperiplanar transition state. This was determined by examination of the product stereochemistry and through detailed DFT analysis. 

An auto-tandem catalytic, branched-selective rearrangement of substituted N-alloc-N-allyl ynamides was developed. This reaction provides ready access to complex quaternary nitrile products with vinylogous stereocentres in excellent diastereoselectivity, including contiguous all-carbon quaternary centres. The stereochemical outcome is determined via a Pd(0) catalysed dipolar ketenimine aza-Claisen rearrangement and computational studies exemplify the key role ligand geometry plays. 

Abstract Axial Seamount is a seafloor volcano with frequent eruptions and periodic cycles of inflation and deflation. Seafloor pressure gauges monitor vertical deformation with time, but inherent instrumental drift complicates and biases geodetic interpretation. A drift corrected pressure recorder was deployed on Axial Seamount on 6 July 2018, at coordinates 45° 57.29′ North latitude, −130° 0.56′ East longitude, depth 1,535 m. This system includes two independent quartz‐resonant pressure gauges, which nearly continuously observe the seafloor pressure. At regular intervals, the gauges are calibrated in situ with a modified deadweight tester at a pressure within 98% of the nominal seafloor pressure. Using the calibration data, the drift of each gauge has been modeled as a simple linear plus decaying exponential function of time. The two estimated linear sensor drift rates are 0.45 ± 0.12 and 0.36 ± 0.08 kPa/year; the modeled sensor drift represents a significant error if uncorrected. The standard deviations of the drift model residuals are of order 0.06 kPa or 6 mm depth equivalent. Once calibrated, the difference between the two seafloor pressure timeseries exhibits a RMS deviation of ±6 mm at the 90% confidence limit and a linear trend less than 1 mm/year. A time series from July 2018 to December 2021 tracks the inflation of Axial Seamount with differing inflation rates over different time intervals. 

The Earth’s mantle is heterogeneous as a result of early planetary differentiation and subsequent crustal recycling during plate tectonics. Radiogenic isotope signatures of mid-ocean ridge basalts have been used for decades to map mantle composition, defining the depleted mantle endmember. These lavas, however, homogenize via magma mixing and may not capture the full chemical variability of their mantle source. Here, we show that the depleted mantle is significantly more heterogeneous than previously inferred from the compositions of lavas at the surface, extending to highly enriched compositions. We perform high-spatial-resolution isotopic analyses on clinopyroxene and plagioclase from lower crustal gabbros drilled on a depleted ridge segment of the northern Mid-Atlantic Ridge. These primitive cumulate minerals record nearly the full heterogeneity observed along the northern Mid-Atlantic Ridge, including hotspots. Our results demonstrate that substantial mantle heterogeneity is concealed in the lower oceanic crust and that melts derived from distinct mantle components can be delivered to the lower crust on a centimetre scale. These findings provide a starting point for re-evaluation of models of plate recycling, mantle convection and melt transport in the mantle and the crust.