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Teaching chatbots to say “I don’t know” could curb hallucinations. It could also break AI’s business model

The xenotransplant, from a gene-edited pig, had survived for nearly 9 months in Tim Andrews

Hippocampal degeneration is a feature of both normal aging and Alzheimer's disease (AD). Prior to macroscopic degeneration, microstructural changes occur such as demyelination, iron deposition, or subtle atrophy, which can be characterized in vivo using MRI. We topographically mapped measures of microstructure and macrostructure across the unfolded surface of the hippocampus in 224 healthy older adults at risk for AD (aged 57 to 87) and 37 younger adults (aged 18 to 37). We describe three...

Tau aggregation into amyloid fibrils is linked to the development of neurodegenerative diseases, including Alzheimer's disease (AD). The molecular processes driving aggregation in disease are still being uncovered, highlighting the need for innovative tools to study aggregation reactions. Here, we introduce FibrilPaint1 as a tool to measure the size of Tau amyloid fibrils in fluids, from early aggregation stages to mature fibrils. FibrilPaint1 is a 22mer peptide with exciting properties: i)...

Altered β-amyloid (Aβ) homeostasis is a critical event triggering the shift from healthy aging to Alzheimer disease (AD) through the overproduction and impaired clearance of Aβ peptides. The Aβ-degrading enzymes (ADEs) are a collective group of proteases that normally promote clearance to counteract Aβ-induced neurodegeneration. We previously discovered that the beta-site amyloid precursor protein cleaving enzyme 1 is an atypical ADE that produces the nontoxic fragment Aβ34 by recognizing 40- or...

Hippocampal degeneration is a feature of both normal aging and Alzheimer's disease (AD). Prior to macroscopic degeneration, microstructural changes occur such as demyelination, iron deposition, or subtle atrophy, which can be characterized in vivo using MRI. We topographically mapped measures of microstructure and macrostructure across the unfolded surface of the hippocampus in 224 healthy older adults at risk for AD (aged 57 to 87) and 37 younger adults (aged 18 to 37). We describe three...

In animal models, exposure to heightened maternal inflammation in utero is associated with altered offspring hippocampal development, including reduced dendritic arborization and density. However, the effects of prenatal maternal inflammation (PNMI) on offspring hippocampal microstructure in humans remain unclear. Here, we examined the relationship between exposure to PNMI and neurite density in the hippocampus and its subfields among offspring during late middle age. Participants included 72...

Altered β-amyloid (Aβ) homeostasis is a critical event triggering the shift from healthy aging to Alzheimer disease (AD) through the overproduction and impaired clearance of Aβ peptides. The Aβ-degrading enzymes (ADEs) are a collective group of proteases that normally promote clearance to counteract Aβ-induced neurodegeneration. We previously discovered that the beta-site amyloid precursor protein cleaving enzyme 1 is an atypical ADE that produces the nontoxic fragment Aβ34 by recognizing 40- or...

INTRODUCTION: Humans and other vertebrates exhibit anisotropic orientation and navigation skills, with better performances in the horizontal compared to the vertical plane. While horizontal navigation accuracy decreases with higher age, less is known about age effects on vertical spatial abilities. The same is true for disorders which cause spatial memory deficits, e.g., cognitive impairment or chronic peripheral vestibular loss.

Aging is characterized by chronic low-grade neuroinflammation, which increases the risk of neurodegenerative disorders. Neuroinflammation, driven by the activation of astrocytes and microglia, underlies age-associated cognitive deficits. Amplified neuroinflammatory responses to immune challenges are attributed to microglial activation in the aged brain. Despite extensive clinical and experimental evidence linking neuroinflammation to aging, the molecular players that control age-associated...

INTRODUCTION: White matter hyperintensity (WMH) is a hallmark imaging biomarker of cerebral small vessel disease and are strongly associated with vascular cognitive impairment in the elderly. Morphological changes in large extracranial brain-feeding arteries, such as the internal carotid (ICA) and vertebral arteries (VA), may alter intracranial hemodynamics and contribute to WMH development. This study examined the relationship between arterial tortuosity and WMHs using magnetic resonance...