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Executive resources shape the impact of language predictability across the adult lifespan
No full textHumans routinely anticipate upcoming language, but whether such predictions come at a cognitive cost remains debated. In this study, we demonstrate the resource-dependent nature of predictive mechanisms in language comprehension across the lifespan: Experimentally limiting executive resources through a concurrent task reduces the effect of language predictability on reading time. Participants (N = 175, replication N = 96) read short articles presented word-by-word while completing a secondary font colour n-back task, thus varying cognitive demand. Language predictability was indexed by word surprisal as derived from a pre-trained large language model (GPT-2). Across two independent samples, our findings reveal that language predictions are not cost-free: They draw on executive control resources, and this dependency becomes more pronounced with age (18-85 years). These results help resolve the debate over cognitive demands in language comprehension and highlight prediction as a dynamic, resource-dependent process across the lifespan
JADES reveals a large population of low-mass black holes at high redshift
No full textJames Webb Space Telescope ( JWST ) has revealed a large population of active galactic nuclei (AGNs) in the distant Universe, which are challenging our understanding of early massive black hole (BH) seeding and growth. We expand the exploration of this population to lower luminosities by stacking similar to 600 NIRSpec grating spectra from the JWST Advanced Deep Extragalactic Survey (JADES) at 3 < z < 7, in bins of redshift, [O III ]5007 luminosity and equivalent width, UV luminosity, and stellar mass. In multiple stacks, we detect a broad component of H alpha without a counterpart in [O III ], implying that it is not due to outflows but traces the broad-line region of a large population of low-luminosity AGNs not detected in individual spectra. The detection, in some stacks, of high [O III ]4363/H gamma, typical of AGNs, further confirms the detection of a large population of AGNs. We infer that the stacks probe BHs with masses of a few times 10(6 )M(circle dot) accreting at rates L/L-Edd similar to 0.02-0.1, i.e. a low-mass and dormant parameter space poorly explored by previous studies on individual targets. We identify populations of BHs that fall within the scatter of the local M-BH -M-& lowast; scaling relation, indicating that there is a population of high- z BHs that are not overmassive relative to their host galaxies. Yet, on average, the stacks are still overmassive relative the local relation, with some of them 1-2 dex above it. We infer that the BH mass function at 3 < z < 5 is consistent with models in which BHs evolve through short bursts of super-Eddington accretion
Connecting JWST discovered N/O-enhanced galaxies to globular clusters: evidence from chemical imprints
No full textRecent James Webb Space Telescope (JWST) observations have revealed a growing population of galaxies at z > 4 with elevated nitrogen-to-oxygen ratios. These 'N/O-enhanced' galaxies (NOEGs) exhibit near to supersolar N/O at sub-solar O/H, clearly deviating from the well-established scaling relation between N/O and O/H observed in local galaxies. The origin of this abundance anomaly is unclear. Interestingly, local globular clusters also exhibit anomalous light-element abundances, whose origin remains debated. In this work, we compare the chemical abundance patterns of 22 known NOEGs at 0 less than or similar to z less than or similar to 12-primarily discovered with JWST-to those observed in local globular clusters. We find similarities in the abundances of C, N, O, Fe, and He between the two populations. The similar abundance patterns support the scenario in which globular cluster stars formed within proto-cluster environments-similar to those traced by NOEGs-that were self-enriched. Indeed, the enhancement in N/O in early galaxies appears to be only found in dense stellar environments with Sigma(*) >= 10(2.5 )M (R) pc(-2), as expected for the progenitors of globular clusters in the Milky Way, and similar to those of star clusters identified in strongly lensed high-redshift galaxies. Furthermore, we find a tentative positive correlation between N/O ratios and stellar mass among NOEGs. The apparent high occurrence rate of NOEGs at high redshift is consistent with the picture of cluster-dominated star formation during the early stages of galaxy evolution. Measuring chemical abundances across diverse stellar environments in high-redshift galaxies will be crucial for elucidating the connection between NOEGs and globular clusters
Amazonian fog harbors viable microbes
No full textFog formation over tropical forests remains poorly characterized, despite its potential role in bioaerosol dispersion and ecosystem processes. Here, we analyzed fog samples collected at the Amazon Tall Tower Observatory using flow cytometry and culture-based techniques to characterize viable microbial communities. Microbial cell concentrations varied over an order of magnitude across 13 fog events, reaching up to 8 × 104 cells per ml of fog water. Flow cytometry consistently detected metabolically active cells, while culturing and mass spectrometry-based identification yielded eight viable bacterial species and seven fungal taxa. The bacteria Serratia marcescens, Ralstonia pickettii and Sphingomonas paucimobilis exhibited seasonal variations in prevalence. The fungal species identified were primarily mesophilic saprophytes and endophytes, commonly associated with soil and plant surfaces. Our findings indicate that fog harbors viable microbes, including Serratia marcescens and Ralstonia pickettii, which may imply a relevance of fog for microbial dispersal, colonization and nutrient cycling in the Amazon rainforest
Suppressing Interfacial Instability of Immiscible Liquid‐in‐Liquid Flow Using Magnetic Forces
No full textInterfacial instability prevents a liquid jet from flowing indefinitely within air or another liquid. An approach is presented here to suppress interfacial instability by means of a magnetic force applied by a ferrofluid envelope around the jet. The stability limits occurring within a large parameter window are experimentally investigated with length and time scales governed by the magnetic Bond number. Instabilities can be generated by modifying the magnetic force strength externally, with a remarkable return to stability when removing the external stimulus. The current system with soft and slippery interfaces enables investigations of flow systems beyond the limits of standard hydrodynamics allowing for exciting applications in flow chemistry, interface engineering and transport of biological materials
FAUST XXVIII. High-resolution ALMA observations of Class 0/I disks: Structure, optical depths, and temperatures
No full textMeasuring the properties of disks around Class 0/I protostars is crucial for understanding protostellar assembly and early planet formation. We present high-resolution (similar to 7.5 au) ALMA continuum observations at 1.3 and 3 mm of 16 disks around Class 0/I protostars across multiple star-forming regions (Taurus, Ophiuchus, and Corona Australis) and a variety of multiplicities. Our observations show a wide range of deconvolved disk sizes (similar to 2-100 au) and the presence of circumbinary disks (CBDs) in all binaries with separations <100 au. The measured properties show similarities to Class II disks, including (a) low spectral index values (alpha(disks) = 2.1(-0.3)(+0.5)) that increase with disk radius, (b) 3 mm disk sizes only marginally smaller than at 1.3 mm (<10%), and (c) radial intensity morphologies well described by modified self-similar profiles. However, there are some key differences: (i) the alpha(1.3-3 mm) values increase monotonically with radius but exceed two only at the disk edge; (ii) higher brightness temperatures, T-b, comparable to or higher than the predicted midplane temperatures due to irradiation; and (iii) an approximately ten times higher luminosity at a given size compared to the Class II disks. Together, the results confirm significant optical depth in the observed Class 0/I disks, most with T-bol < 200 K, at both 1.3 and 3 mm. Assuming fully optically thick disks at these wavelengths can explain the higher luminosities compared with Class II disks, but the most compact (less than or similar to 40 au) disks also require higher temperatures, suggesting additional heating from viscous accretion. Taking into account the high optical depths, most disk dust masses are estimated in the range 30-900 M-circle plus (or 0.01-0.3 M-circle dot in gas), with some disks potentially reaching marginal gravitational instability. Based on the elevated T-b(1.3 mm), the median location of the water iceline is similar to 3 au, but this location can extend to more than 10-20 au for the hottest disks in the sample. The CBDs exhibit lower optical depths at both wavelengths and hence higher spectral index values (tau(3 mm) less than or similar to 1, alpha(CBD) = 3.0(-0.3)(+0.2)), dust masses of similar to 10(2) M-circle plus, and dust emissivity indices of beta(CBD) similar to 1.5 (two Class 0 CBDs) and similar to 1 (one Class I CBD), suggesting substantial grain growth only in the more evolved CBD. The high optical depths inferred from our analysis provide a compelling explanation for the apparent scarcity of dust substructures in the younger Class 0/I disks at similar to 1 mm despite the mounting evidence of early planet formation
