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The occupation history of the Cahokia archaeological complex (ca. AD 1050–1400) has received significant academic attention for decades, but the subsequent repopulation of the region by indigenous peoples is poorly understood. This study presents demographic trends from a fecal stanol population reconstruction of Horseshoe Lake, Illinois, along with information from archaeological, historical, and environmental sources to provide an interpretation of post-Mississippian population change in the Cahokia region. Fecal stanol data indicate that the Cahokia region reached a population minimum by approximately AD 1400, regional population had rebounded by AD 1500, a population maximum was reached by AD 1650, and population declined again by AD 1700. The indigenous repopulation of the area coincides with environmental changes conducive to maize-based agriculture and bison-hunting subsistence practices of the Illinois Confederation. The subsequent regional depopulation corresponds to a complicated period of warfare, epidemic disease, Christianization, population movement, and environmental change in the eighteenth century. The recognition of a post-Mississippian indigenous population helps shape a narrative of Native American persistence over Native American disappearance.

Fecal stanols deposited in sediment provide evidence of trace human waste products and have been proposed as a proxy for measuring population change. Despite its potential to contribute to paleodemographic studies, the method has not been evaluated against conventional archaeological population reconstructions to determine its fidelity in identifying changes in ancient populations nor has it been applied in an environmental setting outside of the Arctic, where low temperatures enhance stanol preservation. We studied sediment cores recovered from a lake adjacent to Cahokia, the largest and most well-studied prehistoric mound center in North America. We found fecal stanol data closely track independently established population reconstructions from multiple sources, confirming the utility of the method and demonstrating its viability in temperate climates.

Northern Vietnam has a long history of human occupation, warfare, and agriculture; yet, the environmental consequences of human activity are poorly understood due to limited paleoecological records. Results from a terrestrial wetland sediment core from the tropical island, Quan Lan, in Ha Long Bay provide a local record of ecosystem responses to societal shifts due to warfare/instability and climate change. A multiproxy study, including pollen, macro charcoal, fecal stanols, and geochemistry, suggests that native vegetation was abundant and low-level, subsistence wet-rice agriculture and burning were in practice during a time of increased monsoon intensity between 1150 BCE and 950 CE. Between 950 and 1450 CE, a trading and military port was established on Quan Lan Island which served as a major hub of southeast Asian trade and protected the mainland from Mongol invasions. During this period, population near the wetland declined to undetectable levels, rice agriculture declined, burning ceased, and disturbance species expanded. A simultaneous shift toward a more arid climate, with possible extended years of drought, occurred during the Medieval Climate Anomaly based on regional climate records. Without a reliable source of freshwater, rice production declined and/or was supplemented by trade. When the mainland capital near present day Hanoi moved south to Hue after 1450 CE, the port ceased operation. During this time, climate became wetter, and precipitation and surface water more reliable than before. Population near the wetland increased as did burning and rice agriculture. The research has implications for understanding the maintenance of tropical biodiversity amidst long-term human occupation, political unrest, and climate change.

A number of competing hypotheses, including hydroclimatic variations, environmental degradation and disturbance, and sociopolitical disintegration, have emerged to explain the dissolution of Cahokia, the largest prehistoric population center in the United States. Because it is likely that Cahokia's decline was precipitated by multiple factors, some environmental and some societal, a robust understanding of this phenomenon will require multiple lines of evidence along with a refined chronology. Here, we use fecal stanol data from Horseshoe Lake, Illinois, as a population proxy for Cahokia and the broader Horseshoe Lake watershed. We directly compare the fecal stanol data with oxygen stable-isotope and paleoenvironmental data from the same sediment cores to evaluate the role of flooding, drought, and environmental degradation in Cahokia's demographic decline and sociopolitical reorganization. We find that Mississippi River flooding and warm season droughts detrimental to agriculture occurred circa (ca.) 1150 CE and possibly generated significant stress for Cahokia's inhabitants. Our findings implicate climate change during the Medieval Climatic Anomaly to Little Ice Age transition as an important component of population and sociopolitical transformations at Cahokia, and demonstrate how climate transitions can simultaneously influence multiple environmental processes to produce significant challenges to society.

Highlights • Conservative management alone, in certain cases, can be an effective method of treating large cerebral abscesses that would normally warrant surgical intervention in patients with complex congenital heart conditions. • Having an alternative, non-surgical, method of treating large brain abscesses in patients with underlying complex congenital heart conditions, in which brain abscesses is a known complication, is of great clinical importance. • Due to the increasing number of patients living longer with congenital heart conditions, further study into the conservative management of larger abscesses is warranted., Introduction We present an unusual case where a large intra-cerebral abscess with severe complications was treated successfully with medical management alone in a patient with Eisenmenger syndrome. Presentation of case A 40 year old patient with Eisenmenger syndrome presented with a seven day history of headache, neck pain and intermittent vomiting and fever. The only neurological examination finding was blurred vision. MRI revealed a large left occipital lobe abscess, which subsequently ruptured into the lateral ventricle with associated ventriculitis and hydrocephalus. This complicated abscess was successfully treated with intravenous antibiotics alone, with complete resolution of the abscess and hydrocephalus on MRI at 13 months post-diagnosis. Discussion Patients with congenital cyanotic heart conditions, like Eisenmenger syndrome, are at increased risk of developing intra-cerebral abscesses. Effectively managing large abscesses with associated intra-ventricular rupture and hydrocephalus in these patients without any form of surgical intervention, including aspiration, is extremely rare. Conclusion Patients with congenital cyanotic heart disease who develop large intra-cerebral abscesses with severe complications, which would normally warrant surgical intervention, have the potential to be successfully treated with antibiotics alone with excellent outcome.