Researchers studying how economic inequality became a durable feature of societies often point to factors such as agricultural intensification or the rise of the state, but a new study by Dongdong Li and colleagues suggests inequality can have much deeper roots. In their analysis of previously published mortuary data from more than 2,300 burials across 6,000 years of settlement in the Central Plain of China, Li et al. conclude that inequality was shaped by social-relational networks that long preceded the rise of the state. The differentiated social positions within these networks could not be explained by agricultural intensification or the size of the population, they found. But the networks did control an individual’s access to labor, resources, and symbolic capital such as ritual objects. The researchers reconstructed these networks in prehistoric China using isotopic, osteological, and zooarchaeological data from sites dated from 7000 to 1500 BCE. Burial wealth as well as signs of skeletal health and dietary variety were proxies for relational inequalities. Li et al. say that differential access to valued but scarce items initially produced unequal social-relational networks in the region, but that changes in subsistence, the rise of mobile wealth, and escalating violent conflict may have reorganized these networks to concentrate ritual, political, military, and technological control. Early states then “stabilized rather than created these pre-existing disparities by institutionalizing control over resources, violence, and network-based access,” the authors conclude.

Co-exposure to heatwaves and air pollution from landscape fires has been increasing globally over the past two decades, according to a new analysis by Yao Wu and colleagues. Respiratory and cardiovascular health risks from landscape fire-related air pollution, as well as from extreme heat, are well documented. These health risks, and the incidence of the fires themselves, are amplified during stretches of extreme temperatures. Wu et al. found that 55.9% of the global population experienced increasing co-exposure between 2000 and 2019. On average, 916 million people each year experienced at least one co-exposure day, increasing by 287 million people per decade. The global annual average co-exposure was 1.3 days per person, rising from 1 day in 2000-2009 to 1.7 days in 2010-2019. During the study period, the top 5 countries with the highest annual averages of person-days of co-exposure to heatwaves and landscape fire smoke pollution were the Democratic Republic of the Congo, Indonesia, Mexico, Brazil, and the Russian Federation.

A proof-of-concept study led by UC’s Agnes (Yu) Luo, PhD, and collaborators at UC Davis shows that an adeno-associated virus (AAV) gene therapy can reduce hydrocephalus-associated tissue damage in animal models, pointing to a potential new treatment strategy.