“Consternation was depicted on all their countenances”: Gettysburg’s African American Community and Confederate Invasion

On June 15, 1863, Albert Jenkins’s Confederate cavalry brigade became the first of Lee’s men to enter the North when it crossed the Potomac River and headed for Chambersburg, Pennsylvania. Lee had issued strict orders forbidding his men to damage or confiscate private property unless it was a requisition made for necessary supplies, and overseen by authorized Confederate staff. Jenkins’s men half-heartedly obeyed, and scoured the area for anything valuable, including African Americans, fugitive or legally free, who might be sold into slavery. One horrified Chambersburg resident watched local blacks attempt to hide in cornfields only to have troopers chase them down through the young stalks. Others capitulated after troopers fired at them. When Lee arrived in Chambersburg on June 27, his horror at scenes of looting and robbery compelled him to reissue his order concerning private property. But he made no mention of over 200 captured African-Americans – some of whom had been born in Chambersburg – removed south by Jenkins’s cavalry. On the same day in nearby Mercersburg, one startled local watching fugitive-filled wagons roll towards Maryland asked a guard how he could do such a thing. Confederates, he replied, were simply “reclaiming their property.” [excerpt

Calm Before the Storm: Gettysburg’s African-American Community Before the Battle

African-Americans have always been a part of Gettysburg’s community fabric. Slaves belonging to Samuel Gettys, the area’s first settler, arrived as early as 1762 to build one of the first local taverns. Samuel’s son James, who founded Gettysburg in 1786, also owned slaves, including Sydney O’Brien. After her owner’s death, O’Brien obtained her freedom, and in purchasing a small lot along South Washington Street helped establish the borough’s African-American neighborhood. The free black community continued to grow over the first decades of the nineteenth century as Pennsylvania’s policy of gradual emancipation effectively ended slavery in the state by the 1840s. And with uniquely promising economic, social, and educational opportunities, Gettysburg attracted black residents, free and enslaved, from a number of neighboring states. [excerpt

Ecophysiology of coral reef primary producers across an upwelling gradient in the tropical central Pacific

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Johnson, M. D., Fox, M. D., Kelly, E. L. A., Zgliczynski, B. J., Sandin, S. A., & Smith, J. E. Ecophysiology of coral reef primary producers across an upwelling gradient in the tropical central Pacific. Plos One, 15(2), (2020): e0228448, doi:10.1371/journal.pone.0228448.Upwelling is an important source of inorganic nutrients in marine systems, yet little is known about how gradients in upwelling affect primary producers on coral reefs. The Southern Line Islands span a natural gradient of inorganic nutrient concentrations across the equatorial upwelling region in the central Pacific. We used this gradient to test the hypothesis that benthic autotroph ecophysiology is enhanced on nutrient-enriched reefs. We measured metabolism and photophysiology of common benthic taxa, including the algae Porolithon, Avrainvillea, and Halimeda, and the corals Pocillopora and Montipora. We found that temperature (27.2–28.7°C) was inversely related to dissolved inorganic nitrogen (0.46–4.63 μM) and surface chlorophyll a concentrations (0.108–0.147 mg m-3), which increased near the equator. Contrary to our prediction, ecophysiology did not consistently track these patterns in all taxa. Though metabolic rates were generally variable, Porolithon and Avrainvillea photosynthesis was highest at the most productive and equatorial island (northernmost). Porolithon photosynthetic rates also generally increased with proximity to the equator. Photophysiology (maximum quantum yield) increased near the equator and was highest at northern islands in all taxa. Photosynthetic pigments also were variable, but chlorophyll a and carotenoids in Avrainvillea and Montipora were highest at the northern islands. Phycobilin pigments of Porolithon responded most consistently across the upwelling gradient, with higher phycoerythrin concentrations closer to the equator. Our findings demonstrate that the effects of in situ nutrient enrichment on benthic autotrophs may be more complex than laboratory experiments indicate. While upwelling is an important feature in some reef ecosystems, ancillary factors may regulate the associated consequences of nutrient enrichment on benthic reef organisms.This work was supported by funding from the Moore Family Foundation, the Gordon and Betty Moore Foundation, the Scripps family, and anonymous donors. The funders had no role in study design, data collection and analysis, or preparation of the manuscript

Reply to “Comment on ‘Accurate and fast numerical solution of Poisson\u27s equation for arbitrary, space-filling Voronoi polyhedra: Near-field corrections revisited’ ”

This is a Reply to the Comment by Gonis and Zhang on our recent paper. They discuss supposed issues with our “accurate and fast numerical solution of Poisson’s equation for arbitrary Voronoi polyhedra” (VP)

A CubeSat for Calibrating Ground-Based and Sub-Orbital Millimeter-Wave Polarimeters (CalSat)

We describe a low-cost, open-access, CubeSat-based calibration instrument that is designed to support ground-based and sub-orbital experiments searching for various polarization signals in the cosmic microwave background (CMB). All modern CMB polarization experiments require a robust calibration program that will allow the effects of instrument-induced signals to be mitigated during data analysis. A bright, compact, and linearly polarized astrophysical source with polarization properties known to adequate precision does not exist. Therefore, we designed a space-based millimeter-wave calibration instrument, called CalSat, to serve as an open-access calibrator, and this paper describes the results of our design study. The calibration source on board CalSat is composed of five "tones" with one each at 47.1, 80.0, 140, 249 and 309 GHz. The five tones we chose are well matched to (i) the observation windows in the atmospheric transmittance spectra, (ii) the spectral bands commonly used in polarimeters by the CMB community, and (iii) The Amateur Satellite Service bands in the Table of Frequency Allocations used by the Federal Communications Commission. CalSat would be placed in a polar orbit allowing visibility from observatories in the Northern Hemisphere, such as Mauna Kea in Hawaii and Summit Station in Greenland, and the Southern Hemisphere, such as the Atacama Desert in Chile and the South Pole. CalSat also would be observable by balloon-borne instruments launched from a range of locations around the world. This global visibility makes CalSat the only source that can be observed by all terrestrial and sub-orbital observatories, thereby providing a universal standard that permits comparison between experiments using appreciably different measurement approaches