Simulations with the Community Earth System Model, version 2, using the Whole Atmosphere Community Climate Model version 6 [CESM2(WACCM6)] configuration, show evidence of dynamical coupling from the high latitudes of the winter middle atmosphere to the tropics and the middle and high latitudes of the summer hemisphere. Analysis of monthly and daily output covering 195 simulation years indicates that the response in the summer middle and high latitudes has a weak overall magnitude of a few kelvins or less in temperature but has a repeatable pattern whose structure and phase agree with observational studies. Lag correlation indicates that perturbations in wave activity in the winter stratosphere, as quantified by Eliassen–Palm (EP) flux divergence, are accompanied by perturbations in the transformed Eulerian-mean meridional wind extending into the summer hemisphere. There is not an appreciable correlation with momentum forcing in the summer hemisphere by either resolved waves or parameterized gravity waves. The rapid circulation response and the lack of a wave response in the summer hemisphere suggest that the interhemispheric coupling that is simulated in WACCM6 in both the stratosphere and the mesosphere owes its existence to a circulation that develops to restore balance to the zonally averaged state of the atmosphere. This is an alternative explanation for the coupling from the winter stratosphere to the summer mesosphere; previous studies have assumed a necessary role for wave activity in the summer hemisphere.

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Highlights Machine learning approaches allow for the simultaneous analysis to an entire microCT dataset to minimize bias and demonstrated that collective microarchitectural changes. K-Means clusters and Support Vector Machine classification visualization provide intuitive interpretations of the differences in bone structure and microarchitecture between groups. These techniques are complimentary to common statistical testing and provide additional ways of showing differences between microCT outcomes.

Three-dimensional (3D) imaging of osteocyte lacunae has recently substantiated the connection between lacunar shape and size, and osteocyte age, viability, and mechanotransduction. Yet it remains unclear why individual osteocytes reshape their lacunae and how networks of osteocytes change in response to local alterations in mechanical loads. We evaluated the effects of local mechanical stimuli on osteocyte lacunar morphometrics in tibial cortical bone from young female mice flown on the Space Shuttle for ~13 days. We optimized scan parameters, using a laboratory-based submicrometer-resolution X-Ray Microscope, to achieve large ~ 0.3 mm3 fields of view with sufficient resolution (≥ 0.3 μm) to visualize and measure thousands of lacunae per scan. Our novel approach avoids large measurement errors that are inherent in 2D and enables a facile 3D solution as compared to the lower resolution from benchtop micro-computed tomography (CT) systems or the cost and inaccessibility of synchrotron-based CT. Osteocyte lacunae were altered following microgravity exposure in a region-specific manner: more elongated (+7.0% Stretch) in predominately tensile-loaded bone as compared to those in compressively-loaded regions. In compressively-loaded bone, lacunae formed in microgravity were significantly larger (+6.9% Volume) than in the same region formed on Earth. We also evaluated lacunar heterogeneity (i.e., spatial autocorrelation of lacunar morphometric parameters) via kriging models. These statistical models demonstrated that heterogeneity varied with underlying spatial contributors, i.e. the local mechanical and biological environment. Yet in the absence of gravitational loading, osteocyte lacunae in newly formed bone were larger and were collectively more homogenous than in bone formed on Earth. Overall, this study shows that osteocyte reshape their lacunae in response to changes, or absence, in local mechanical stimuli and different biological environments. Additionally, spatial relationships among osteocytes are complex and necessitate evaluation in carefully selected regions of interest and of large cell populations.

Intra‐African conflicts during the collapse of the kingdom of Oyo from 1817 to 1836 resulted in the enslavement of an estimated 121,000 people who were then transported to coastal ports via complex trade networks and loaded onto slave ships destined for the Americas. Historians have a good record of where these people went across the Atlantic, but little is known about where individuals were from or enslaved within Africa. In this work, we develop a novel statistical modelling strategy to describe the enslavement of people given documented violent conflict, the transport of enslaved peoples from their location of capture to their port of departure, and—given an enslaved individual's location of departure—that person's probability of origin. We combine spatial prediction of conflict density via kriging with a Markov decision process characterising intra‐African transportation. The results of this model can be visualised using an interactive web application to plot—for the first time—estimated conditional probabilities of historical origins during the African diaspora. Understanding the likely origins within Africa of enslaved people may have ramifications for the history of the Atlantic world, whereby the ocean connects, rather than disconnects, Africa, the Americas, and Europe.