Katherine Burgess

Memphis city mayor Paul Young greets people while making his way through the crowd after closing his speech at Mount Vernon Baptist Church on Tuesday evening. Photo by Andrea Morales for MLK50 Memp…

Marshalls stand between marchers making their way down Central Avenue and Memphis police officers in April. Photo by Brandon Dill for MLK50 When a group of immigrant rights advocates walked through…

We report the H, C, and N isotopic compositions of microscale (0.2 to 2 µm) organic matter in samples of asteroid Ryugu and the Orgueil CI carbonaceous chondrite. Three regolith particles of asteroid Ryugu, returned by the Hayabusa2 spacecraft, and several fragments of Orgueil were analyzed by NanoSIMS isotopic imaging. The isotopic distributions of the Ryugu samples from two different collection spots are closely similar to each other and to the Orgueil samples, strengthening the proposed Ryugu-CI chondrite connection. Most individual sub-μm organic grains have isotopic compositions within error of bulk values, but 2–10 % of them are outliers exhibiting large isotopic enrichments or depletions in D, 15N, and/or 13C. The H, C and N isotopic compositions of the outliers are not correlated with each other: while some organic grains are both D- and 15N-enriched, many are enriched or depleted in one or the other system. This most likely points to a diversity in isotopic fractionation pathways and thus diversity in the local formation environments for the individual outlier grains. The observation of a relatively small population of isotopic outlier grains can be explained either by escape from nebular and/or parent body homogenization of carbonaceous precursor material or addition of later isotopic outlier grains. The strong chemical similarity of isotopically typical and isotopically outlying grains, as reflected by synchrotron x-ray absorption spectra, suggests a genetic connection and thus favors the former, homogenization scenario. However, the fact that even the least altered meteorites show the same pattern of a small population of outliers on top of a larger population of homogenized grains indicates that some or most of the homogenization occurred prior to accretion of the macromolecular organic grains into asteroidal parent bodies.

Jump to a section Gun diversion • Aggravated prostitution • Friends of George’s • Bail setting and reforms • Partnerships with Just City and Vera • What is misinformation? • Attempt to oust M…

Sen. Taylor's criticisms are often broad, and those examples that are specific — such as Mulroy not prosecuting drag shows — often lack in context.

As he faces an effort to oust him from office, Shelby County District Attorney Steve Mulroy has been accused of, among other things, offering too many plea deals and dismissing too many cases. In p…

Kema Mosby checked the MATA app early one morning while waiting at a bus stop on her way to work. Photo by Andrea Morales for MLK50 As the remnants of Hurricane Francine brought high winds and rain…

A rider loads on to bus route 52 on a rainy morning earlier this month. Photo by Andrea Morales for MLK50 The city of Memphis is not releasing funding budgeted for the Memphis Area Transit Authorit…

The Board of the Memphis Area Transit Authority voted last month to take its operating budget from the $85 million needed to continue current operations to a new budget of $67.8 million, reflecting…

Sammie Hunter, 53, (left) stands at a bus stop on East Brooks Road while waiting on a transfer during his commute home in August 2017. The trip home is about a ten-minute car ride but takes him at …