JWST sees little red dots
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Photometric detection at 7.7 μm of a galaxy beyond redshift 14 with JWST/MIRI
The James Webb Space Telescope (JWST) has spectroscopically confirmed numerous galaxies at z > 10. While weak rest-frame ultraviolet emission lines have only been seen in a handful of sources, the stronger rest-frame optical emission lines are highly diagnostic and accessible at mid-infrared wavelengths with the Mid-Infrared Instrument (MIRI) of JWST. We report the photometric detection of the distant spectroscopically confirmed galaxy JADES-GS-z14-0 at (z=14.3{2}_{-0.20}^{+0.08}) with MIRI at 7.7 μm. The most plausible solution for the stellar-population properties is that this galaxy contains half a billion solar masses in stars with a strong burst of star formation in the most recent few million years. For this model, at least one-third of the flux at 7.7 μm originates from the rest-frame optical emission lines Hβ and/or [O iii]λλ4959, 5007. The inferred properties of JADES-GS-z14-0 suggest rapid mass assembly and metal enrichment during the earliest phases of galaxy formation. This work demonstrates the unique power of mid-infrared observations in understanding galaxies at the redshift frontier.
Extended phenotypic spectrum of benign yellow dot maculopathy
To present the morphological and functional characteristics of individuals with benign yellow dot maculopathy (BYDM).
Maternal immune activation imprints translational dysregulation and differential MAP2 phosphorylation in descendant neural stem cells
Alterations induced by maternal immune activation (MIA) during gestation impact the subsequent neurodevelopment of progeny, a process that in humans, has been linked to the development of several neuropsychiatric conditions. To undertake a comprehensive examination of the molecular mechanisms governing MIA, we have devised an in vitro model based on neural stem cells (NSCs) sourced from fetuses carried by animals subjected to Poly I:C treatment. These neural progenitors demonstrate proliferative capacity and can be effectively differentiated into both neurons and glial cells. Transcriptomic, proteomic, and phosphoproteomic analyses conducted on these cellular models, in conjunction with counterparts from control treatments, revealed discernible shifts in the expression levels of a specific subset of proteins implicated in neuronal function. Furthermore, the phosphoproteomic data highlighted a discernible discrepancy in the basal phosphorylation of proteins between differentiated cells from both experimental groups, particularly within proteins associated with cytoskeletal architecture and synaptic functionality, notably those belonging to the MAP family. Observed alterations in MAP phosphorylation were found to potentially have functional consequences as they correlate with changes in neuronal plasticity and the establishment of neuronal synapses. Our data agrees with previous published observations and further underscore the importance of MAP2 phosphorylation state on its function and the impact that this protein has in neuronal structure and function.
Intercity personnel exchange is more effective than policy transplantation at reducing water pollution
Severe spatial disparities exist in water pollution and water governance. A popular solution is that lagging cities transplant policies from cities with successful experiences. However, environmental governance is more than policies. Merely copying policies from elsewhere may not generate intended effects. Here this research argues that intercity personnel exchange can be a more effective policy instrument than policy transplantation. We provide the first nationwide estimates in China of the effect of intercity exchange of city leaders on water pollution reduction. Using large-scale micro-level datasets on city leaders’ curriculum vitae, firm behaviors, patents and policy texts, we show that intercity exchange of city leaders leads to a 4.78–15.26% reduction in firm-level water pollution, which contributes to 39.45–57.98% of the national total water pollution reduction from 2006 to 2013. Exchanged city leaders facilitate the diffusion of governance experience across cities and the formulation of intercity cooperation. They are also more likely to initiate new policies to support industrial upgrading. Our findings highlight the importance and potential of intercity personnel exchange as a policy instrument for water governance in particular and green transition in general.
Subcellular proteomics and iPSC modeling uncover reversible mechanisms of axonal pathology in Alzheimer’s disease
Dystrophic neurites (also termed axonal spheroids) are found around amyloid deposits in Alzheimer’s disease (AD), where they impair axonal electrical conduction, disrupt neural circuits and correlate with AD severity. Despite their importance, the mechanisms underlying spheroid formation remain incompletely understood. To address this, we developed a proximity labeling approach to uncover the proteome of spheroids in human postmortem and mouse brains. Additionally, we established a human induced pluripotent stem cell (iPSC)-derived AD model enabling mechanistic investigation and optical electrophysiology. These complementary approaches revealed the subcellular molecular architecture of spheroids and identified abnormalities in key biological processes, including protein turnover, cytoskeleton dynamics and lipid transport. Notably, the PI3K/AKT/mTOR pathway, which regulates these processes, was activated in spheroids. Furthermore, phosphorylated mTOR levels in spheroids correlated with AD severity in humans. Notably, mTOR inhibition in iPSC-derived neurons and mice ameliorated spheroid pathology. Altogether, our study provides a multidisciplinary toolkit for investigating mechanisms and therapeutic targets for axonal pathology in neurodegeneration.
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