The Entrenchment of 'Non-Sectarian' Sunnism in Yemen

One of the salient features of religious life in Yemen in the modern period has been the fading of historically rooted Yemeni forms of Islam. Zaydi scholars, for example, have been reduced to a minority group within the body of the ulama and have little say in the running of the country's affairs. The Shafici Sufis of the Hadramaut have faired even worse. The most visible form of Islam, and the one actively promoted by the state, claims to be above the sectarian identities of the Yemenis and ultimately adheres to the Salafi school. This requires explanation since Salafism is not usually associated with Yemen's religious and intellectual history

The Entrenchment of 'Non-Sectarian' Sunnism in Yemen

One of the salient features of religious life in Yemen in the modern period has been the fading of historically rooted Yemeni forms of Islam. Zaydi scholars, for example, have been reduced to a minority group within the body of the ulama and have little say in the running of the country's affairs. The Shafici Sufis of the Hadramaut have faired even worse. The most visible form of Islam, and the one actively promoted by the state, claims to be above the sectarian identities of the Yemenis and ultimately adheres to the Salafi school. This requires explanation since Salafism is not usually associated with Yemen's religious and intellectual history

Disentangling tau and brain atrophy cluster heterogeneity across the Alzheimer's disease continuum

IntroductionNeuroimaging heterogeneity in dementia has been examined using single modalities. We evaluated the associations of magnetic resonance imaging (MRI) atrophy and flortaucipir positron emission tomography (PET) clusters across the Alzheimer's disease (AD) spectrum.MethodsWe included 496 Alzheimer's Disease Neuroimaging Initiative participants with brain MRI, flortaucipir PET scan, and amyloid beta biomarker measures obtained. We applied a novel robust collaborative clustering (RCC) approach on the MRI and flortaucipir PET scans. We derived indices for AD-like (SPARE-AD index) and brain age (SPARE-BA) atrophy.ResultsWe identified four tau (I-IV) and three atrophy clusters. Tau clusters were associated with the apolipoprotein E genotype. Atrophy clusters were associated with white matter hyperintensity volumes. Only the hippocampal sparing atrophy cluster showed a specific association with brain aging imaging index. Tau clusters presented stronger clinical associations than atrophy clusters. Tau and atrophy clusters were partially associated.ConclusionsEach neuroimaging modality captured different aspects of brain aging, genetics, vascular changes, and neurodegeneration leading to individual multimodal phenotyping

Disentangling tau and brain atrophy cluster heterogeneity across the Alzheimer's disease continuum

Abstract Introduction Neuroimaging heterogeneity in dementia has been examined using single modalities. We evaluated the associations of magnetic resonance imaging (MRI) atrophy and flortaucipir positron emission tomography (PET) clusters across the Alzheimer's disease (AD) spectrum. Methods We included 496 Alzheimer's Disease Neuroimaging Initiative participants with brain MRI, flortaucipir PET scan, and amyloid beta biomarker measures obtained. We applied a novel robust collaborative clustering (RCC) approach on the MRI and flortaucipir PET scans. We derived indices for AD‐like (SPARE‐AD index) and brain age (SPARE‐BA) atrophy. Results We identified four tau (I–IV) and three atrophy clusters. Tau clusters were associated with the apolipoprotein E genotype. Atrophy clusters were associated with white matter hyperintensity volumes. Only the hippocampal sparing atrophy cluster showed a specific association with brain aging imaging index. Tau clusters presented stronger clinical associations than atrophy clusters. Tau and atrophy clusters were partially associated. Conclusions Each neuroimaging modality captured different aspects of brain aging, genetics, vascular changes, and neurodegeneration leading to individual multimodal phenotyping