Sarah Rogers

IntroductionCognitive impairment is a highly prevalent non-motor feature of Parkinson’s disease. A better understanding of the underlying pathophysiology may help in identifying therapeutic targets to prevent or treat dementia. This study sought to identify metabolic alterations in the prefrontal cortex, a key region for cognitive functioning that has been implicated in cognitive dysfunction in PD.MethodsProton Magnetic Resonance Spectroscopy was used to investigate metabolic changes in the PFC of a cohort of cognitively normal individuals without PD, as well as PD participants with either normal cognition, mild cognitive impairment, or dementia. Ratios to Creatine resonance were obtained for glutamate, glutamine and glutamate combined, N-acetylaspartate, myoinositol, and total choline, and correlated with cognitive scores across multiple domains administered to the PD participants only.ResultsWhen individuals retain cognitive capabilities, the presence of Parkinson’s disease does not create metabolic disturbances in the PFC. However, when cognitive symptoms are present, PFC Glu/Cre ratios decrease with significant differences between the PD-NC and PPD groups. In addition, Glu/Cre ratios and memory scores were marginally associated, but not after Bonferroni correction.ConclusionThese preliminary findings indicate that fluctuations in prefrontal glutamate may constitute a biomarker for the progression of cognitive impairments in PD. We caution for larger MRS investigations of carefully defined PD groups.

Agricultural modernisation is a longstanding goal of China’s Party-state. Since the early 2000s, it has pursued this goal through policies designed to facilitate land consolidation and support the expansion of large agricultural enterprises – ‘New Agricultural Operators’ (NAOs). In this paper we explore the effect of these policies on the livelihoods of a cohort of smallholder orange growers in the mountainous regions of Hubei province and the local political economy. An analysis of data from a 2019 survey of 266 households and interviews with villagers, agribusiness executives, cooperative leaders, and government officials, we find smallholder farmers are earning good incomes as independent commodity producers, withstanding attempts by local officials at land consolidation, and bypassing NAOs to self-determine their own modes of production and exchange. Our results speak to the ongoing debate about the future of smallholder farming in China, identify the strengths and limitations of recent state-centric analyses of agrarian transition, and re-iterate the pitfalls of the central government’s agricultural modernisation agenda.