Browse Articles

Retinal ganglion cells encode the direction of motion outside their classical receptive field

Retinal ganglion cells (RGCs) typically respond to light stimulation over their spatially restricted receptive field. Using large-scale recordings in the mouse retina, we show that a subset of non- direction-selective (DS) RGCs exhibit asymmetric activity, selective to motion direction, in response to a stimulus crossing an area far beyond the classic receptive field. The extraclassical response arises via inputs from an asymmetric distal zone and is enhanced by desensitization mechanisms and an inherent DS component, creating a network of neurons responding to motion toward the optic disc. Pharmacological manipulations revealed the necessity of glycinergic amacrine cells for this response. Using in vivo recordings, we identified similar extraclassical responses in lateral geniculate nucleus neurons, suggesting such non conventional DS information is transferred to downstream structures. Our results suggest a complex integration of motion direction processing across the visual field, which arises beyond the classical receptive field boundaries.

Chromatin enables precise and scalable gene regulation with factors of limited specificity

Biophysical constraints limit the specificity with which transcription factors (TFs) can target regulatory DNA. While individual nontarget binding events may be low affinity, the sheer number of such interactions could present a challenge for gene regulation by degrading its precision or possibly leading to an erroneous induction state. Chromatin can prevent nontarget binding by rendering DNA physically inaccessible to TFs, at the cost of energy-consuming remodeling orchestrated by pioneer factors (PFs). Under what conditions and by how much can chromatin reduce regulatory errors on a global scale? We use a theoretical approach to compare two scenarios for gene regulation: one that relies on TF binding to free DNA alone and one that uses a combination of TFs and chromatin-regulating PFs to achieve desired gene expression patterns. We find, first, that chromatin effectively silences groups of genes that should be simultaneously OFF, thereby allowing more accurate graded control of expression for the remaining ON genes. Second, chromatin buffers the deleterious consequences of nontarget binding as the number of OFF genes grows, permitting a substantial expansion in regulatory complexity. Third, chromatin-based regulation productively co-opts nontarget TF binding for ON genes in order to establish a “leaky” baseline expression level, which targeted activator or repressor binding subsequently up- or down-modulates. Thus, on a global scale, using chromatin simultaneously alleviates pressure for high specificity of regulatory interactions and enables an increase in genome size with minimal impact on global expression error.

Electrochemical NAD+ regeneration in bacterial organelles

The 1831 CE mystery eruption identified as Zavaritskii caldera, Simushir Island (Kurils)

Polar ice cores and historical records evidence a large-magnitude volcanic eruption in 1831 CE. This event was estimated to have injected ~13 Tg of sulfur (S) into the stratosphere which produced various atmospheric optical phenomena and led to Northern Hemisphere climate cooling of ~1 °C. The source of this volcanic event remains enigmatic, though one hypothesis has linked it to a modest phreatomagmatic eruption of Ferdinandea in the Strait of Sicily, which may have emitted additional S through magma–crust interactions with evaporite rocks. Here, we undertake a high-resolution multiproxy geochemical analysis of ice-core archives spanning the 1831 CE volcanic event. S isotopes confirm a major Northern Hemisphere stratospheric eruption but, importantly, rule out significant contributions from external evaporite S. In multiple ice cores, we identify cryptotephra layers of low K andesite-dacite glass shards occurring in summer 1831 CE and immediately prior to the stratospheric S fallout. This tephra matches the chemistry of the youngest Plinian eruption of Zavaritskii, a remote nested caldera on Simushir Island (Kurils). Radiocarbon ages confirm a recent (<300 y) eruption of Zavaritskii, and erupted volume estimates are consistent with a magnitude 5 to 6 event. The reconstructed radiative forcing of Zavaritskii (−2 ± 1 W m −2 ) is comparable to the 1991 CE Pinatubo eruption and can readily account for the climate cooling in 1831–1833 CE. These data provide compelling evidence that Zavaritskii was the source of the 1831 CE mystery eruption and solve a confounding case of multiple closely spaced observed and unobserved volcanic eruptions.

A detailed spatiotemporal atlas of the white matter tracts for the fetal brain

This study presents the construction of a comprehensive spatiotemporal atlas of white matter tracts in the fetal brain for every gestational week between 23 and 36 wk using diffusion MRI (dMRI). Our research leverages data collected from fetal MRI scans, capturing the dynamic changes in the brain’s architecture and microstructure during this critical period. The atlas includes 60 distinct white matter tracts, including commissural, projection, and association fibers. We employed advanced fetal dMRI processing techniques and tractography to map and characterize the developmental trajectories of these tracts. Our findings reveal that the development of these tracts is characterized by complex patterns of fractional anisotropy (FA) and mean diffusivity (MD), coinciding with the intensity of histogenic processes such as axonal growth, involution of the radial-glial scaffolding, and synaptic pruning. This atlas can serve as a useful resource for neuroscience research and clinical practice, improving our understanding of the fetal brain and potentially aiding in the early diagnosis of neurodevelopmental disorders. By detailing the normal progression of white matter tract development, the atlas can be used as a benchmark for identifying deviations that may indicate neurological anomalies or predispositions to disorders.

Integrin-activating <i>Yersinia</i> protein Invasin sustains long-term expansion of primary epithelial cells as 2D organoid sheets

Matrigel ® /BME ® , a basement membrane-like preparation, supports long-term growth of epithelial 3D organoids from adult stem cells [T. Sato et al. , Nature 459 , 262–265 (2009); T. Sato et al. , Gastroenterology 141 , 1762–1772 (2011)]. Here, we show that interaction between Matrigel’s major component laminin-111 with epithelial α6β1-integrin is crucial for this process. The outer membrane protein Invasin of Yersinia is known to activate multiple integrin–β1 complexes, including integrin α6β1. A C-terminal integrin-binding fragment of Invasin, coated on culture plates, mediated gut epithelial cell adhesion. Addition of organoid growth factors allowed multipassage expansion in 2D. Polarization, junction formation, and generation of enterocytes, goblet cells, Paneth cells, and enteroendocrine cells were stable over time. Sustained expansion of other human, mouse, and even snake epithelia was accomplished under comparable conditions. The 2D “organoid sheet” format holds advantages over the 3D “in gel” format in terms of imaging, accessibility of basal and apical domains, and automation for high-throughput screening. Invasin represents a fully defined, affordable, versatile, and animal-free complement to Matrigel ® /BME ® .

Moisture-driven carbonation kinetics for ultrafast CO ₂ mineralization

CO 2 mineralization, a process where CO 2 reacts with minerals to form stable carbonates, presents a sustainable approach for CO 2 sequestration and mitigation of global warming. While the crucial role of water in regulating CO 2 mineralization efficiency is widely acknowledged, a comprehensive understanding of the underlying mechanisms remains elusive. This study employs a combined experimental and atomistic simulation approach to elucidate the intricate mechanisms governing moisture-driven carbonation kinetics of calcium-bearing minerals. A self-designed carbonation reactor equipped with an ultrasonic atomizer is used to meticulously control the water content during carbonation experiments. Grand Canonical Monte Carlo simulations reveal that maximum CO 2 uptake occurs at a critical water content where the initiation of capillary condensation significantly enhanced liquid–gas interactions. This phenomenon leads to CO 2 adsorption–driven ultrafast carbonation at an optimal moisture content (0.1 to 0.2 g/g, water mass ratio to total wet mass of the mineral). A higher moisture content decimates the carbonation rate by crippling CO 2 intake within mineral pores. However, at exceptionally high moisture levels, the carbonation reaction sites shift from internal mesopores to the grain surface. This results in surface dissolution–driven ultrafast carbonation, attributed to the monotonically decreasing free energy of dissolution with increasing surface water thickness, as revealed by metadynamics simulations. This study provides a fundamental and unified understanding of the multifaceted role of water in mineral carbonation, paving the way for optimizing ultrafast CO 2 mineralization strategies for global decarbonization efforts.

RNAi of the elastomeric protein resilin reduces jump velocity and resilience to damage in locusts

Resilin, an elastomeric protein with remarkable physical properties that outperforms synthetic rubbers, is a near-ubiquitous feature of the power amplification mechanisms used by jumping insects. Catapult-like mechanisms, which incorporate elastic energy stores formed from a composite of stiff cuticle and resilin, are frequently used by insects to translate slow muscle contractions into rapid-release recoil movements. The precise role of resilin in these jumping mechanisms remains unclear, however. We used RNAi to reduce resilin deposition in the principal energy-storing springs of the desert locust ( Schistocerca gregaria ) before measuring jumping performance. Knockdown reduced the amount of resilin-associated fluorescence in the semilunar processes (SLPs) by 44% and reduced the cross-sectional area of the tendons of the hind leg extensor-tibiae muscle by 31%. This affected jumping in three ways: First, take-off velocity was reduced by 15% in knockdown animals, which could be explained by a change in the extrinsic stiffness of the extensor-tibiae tendon caused by the decrease in its cross-sectional area. Second, knockdown resulted in permanent breakages in the hind legs of 29% of knockdown locusts as tested by electrical stimulation of the extensor muscle, but none in controls. Third, knockdown locusts exhibited a greater decline in distance jumped when made to jump in rapid succession than did controls. We conclude that stiff cuticle acts as the principal elastic energy store for insect jumping, while resilin protects these more brittle structures against breakage from repeated use.

Earliest evidence of sedentism in the Antilles: Multiple isotope data from Canímar Abajo, Cuba

The early populations that inhabited the Antilles were traditionally understood as highly mobile groups of hunters/fishers and gatherers. Although more recent data have demonstrated that some populations engaged in the production of domestic plants and cultivars, questions remain about other aspects of their lifeways, including whether the adoption of domesticates was accompanied by a decrease in residential mobility. The level of sedentism in a population is an instrumental variable to understand community social relations and complexity, adaptations, and lifeways. Here, we combined enamel strontium ( 87 Sr/ 86 Sr), oxygen (δ 18 O en ), and carbon (δ 13 C en ) isotopes of 44 human teeth from the site of Canímar Abajo—where the oldest human remains from the insular Caribbean have been reported—to examine the mobility patterns of early Antillean groups. In contrast with traditional narratives, the homogeneous strontium isotope values observed in most individuals from the older funerary area of the site (cal. BC 2237–790) were consistent with the pattern expected for a sedentary population subsisting primarily on local resources obtained close to the coast. The isotopic evidence reveals that between cal. AD 403–1282, the mound was reused for funerary practices by both local communities and nonlocal individuals. The evidence suggests that this period saw higher population mobility, with influxes of individuals from more distant locations and diverse dietary and burial traditions. The isotope results from Canímar Abajo provide the earliest isotopic evidence of populations with low-level residential mobility in the Antilles.

Family relations of Moche elite burials on the North Coast of Peru (~500 CE): Analyses of the Señora de Cao and relatives

The Moche archaeological culture flourished along Peru’s North Coast between the 4th and 10th centuries CE and was characterized by a complex social hierarchy dominated by political and religious elites. Previous archaeological evidence suggests kinship was a key factor in maintaining political authority within Moche society. To test this hypothesis, we applied archaeological, genetic, and isotopic methods to examine familial relationships between six individuals, including the prominent Señora de Cao ( ~500 CE ), buried together in a pyramid-like, painted temple, Huaca Cao Viejo, in the Chicama Valley, Peru. Our findings reveal that all six individuals were biologically related, with varying degrees of kinship. The Señora de Cao was interred with a sacrificed juvenile, identified as a possible niece, and at least one, and potentially two siblings and a grandparent in separate tombs nearby. One of the male siblings was accompanied in death by his sacrificed son. Isotopic analysis indicates that while most individuals had diets rich in maize and animal protein and spent their childhoods in or near the Chicama Valley, the sacrificed juvenile accompanying the Señora had a distinct diet and geographic origin. These results demonstrate that Moche elites were interred with family members, including some raised far from their parental homes. This supports the hypothesis that kinship was central to transmitting status and authority. Moreover, sacrificing family members to accompany deceased elites underscores the significance of ritual sacrifice in reinforcing familial ties and linking the deceased to both ancestors and the divine.

Comparing cooperative geometric puzzle solving in ants versus humans

Biological ensembles use collective intelligence to tackle challenges together, but suboptimal coordination can undermine the effectiveness of group cognition. Testing whether collective cognition exceeds that of the individual is often impractical since different organizational scales tend to face disjoint problems. One exception is the problem of navigating large loads through complex environments and toward a given target. People and ants stand out in their ability to efficiently perform this task not just individually but also as a group. This provides a rare opportunity to empirically compare problem-solving skills and cognitive traits across species and group sizes. Here, we challenge people and ants with the same “piano-movers” load maneuvering puzzle and show that while ants perform more efficiently in larger groups, the opposite is true for humans. We find that although individual ants cannot grasp the global nature of the puzzle, their collective motion translates into emergent cognitive skills. They encode short-term memory in their internally ordered state and this allows for enhanced group performance. People comprehend the puzzle in a way that allows them to explore a reduced search space and, on average, outperform ants. However, when communication is restricted, groups of people resort to the most obvious maneuvers to facilitate consensus. This is reminiscent of ant behavior, and negatively impacts their performance. Our results exemplify how simple minds can easily enjoy scalability while complex brains require extensive communication to cooperate efficiently.

Persistent humid climate favored the Qin and Western Han Dynasties in China around 2,200 y ago

The Qin and Western Han dynasties (221 BCE to 24 CE) represent an era of societal prosperity in China. However, due to a lack of high-resolution paleoclimate records it is still unclear whether the agricultural boost documented for this period was associated with more favorable climatic conditions. Here, multiparameter analysis of annually resolved tree-ring records and process-based physiological modeling provide evidence of stable and consistently humid climatic conditions during 270 to 77 BCE in northern China. Precipitation in the Asian summer monsoon region during the Qin–Western Han Dynasties was ~18 to 34% higher compared to present-day conditions. In shifting agricultural and pastoral boundaries ~60 to 100 km northwestward, possibility up to 200 km at times, persistently wetter conditions arguably increased food production, contributing to the socioeconomic prosperity around 2,200 y ago. A gradual wetting trend in the western part of arid northwestern China since the 1980s resembles the historical climate analogue, suggesting that similar benefits for regional environmental and agricultural systems may reoccur under current climate change, at least in the near term.

The effect of CO ₂ ramping rate on the transient weakening of the Atlantic Meridional Overturning Circulation

The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the global climate that is projected to weaken under future anthropogenic climate change. While many studies have investigated the AMOC’s response to different levels and types of forcing in climate models, relatively little attention has been paid to the AMOC’s sensitivity to the rate of forcing change, despite it also being highly uncertain in future emissions scenarios. In this study, I isolate the AMOC’s response to different rates of CO 2 increase in a state-of-the-art global climate model and find that the AMOC undergoes more severe weakening under faster rates of CO 2 change, even when the magnitude of CO 2 change is the same. I then propose an AMOC-ocean heat transport-sea ice feedback that enhances the decline of the circulation and explains the dependence on the rate of forcing change. The AMOC’s rate-sensitive behavior leads to qualitatively different climates (including differing Arctic sea ice evolution) at the same CO 2 concentration, highlighting how the rate of forcing change is itself a key driver of global climatic change.

Aerosol light absorption alleviates particulate pollution during wintertime haze events

Aerosol light absorption has been widely considered as a contributing factor to the worsening of particulate pollution in large urban areas, primarily through its role in stabilizing the planetary boundary layer (PBL). Here, we report that absorption-dominated aerosol–radiation interaction can decrease near-surface fine particulate matter concentrations ([PM 2.5 ]) at a large-scale during wintertime haze events. A “warm bubble” effect by the significant heating rate of absorbing aerosols above the PBL top generates a secondary circulation, enhancing the upward motion (downward motion) and the convergence (divergence) in polluted (relatively clean) areas, with a net effect of lowering near-surface [PM 2.5 ]. Furthermore, aerosol absorption of ultraviolet-wave light effectively reduces the photolysis of chemical species, i.e., aerosol–photolysis interaction, hindering ozone formation, reducing atmospheric oxidizing capability, and suppressing secondary aerosol concentrations. Our model assessment reveals that the synergetic two effects decrease near-surface [PM 2.5 ] by around 7.4%, so the presence of light-absorbing aerosols can considerably alleviate particulate pollution during wintertime haze events. Such negative feedbacks to the aerosol loading should be considered in weather/climate prediction and health assessment models.

Divergence time and environmental similarity predict the strength of morphological convergence in stick and leaf insects

Independent evolution of similar traits in lineages inhabiting similar environments (convergent or repeated evolution) is often taken as evidence for adaptation by natural selection, and used to illustrate the predictability of evolution. Yet convergence is rarely perfect for two reasons. First, environments may not be as similar as they appear. Second, responses to selection are contingent upon available genetic variation and independent lineages may differ in the alleles, genetic backgrounds, and even the developmental mechanisms responsible for the phenotypes in question. Both impediments to convergence are predicted to increase as the length of time separating two lineages increases, making it difficult to discern their relative importance. We quantified environmental similarity and the extent of convergence to show how habitat and divergence time each contribute to observed patterns of morphological evolution in 212 species of stick and leaf insects (order Phasmatodea). Dozens of phasmid lineages independently colonized similar habitats, repeatedly evolving in parallel directions on a 23-trait morphospace, though the magnitude and direction of these shifts varied. Lineages converging toward more similar environments ended up closer on the morphospace, as did closely related lineages, and closely related lineages followed more parallel evolutionary trajectories to arrive there than more distantly related ones. Remarkably, after accounting for habitat similarity, we show that divergence time reduced the extent of convergence at a constant rate across more than 100 My of separation, suggesting even the magnitude of contingency can be predictable, given sufficient spans of time.

The effect of job loss on risky financial decision-making

Job loss is a common and disruptive life event. It is known to have numerous long-term negative effects on financial, health, and social outcomes. While the negative effects of becoming unemployed on health and well-being are well understood, the influence of job loss on financial decisions has received little attention. Across a large-scale survey ( N = 37 , 854 ), spending data from a bank ( N = 404 , 470 ), and two online experiments (total N = 1 , 403 ), we find that job loss increases financial risk-taking. First, in survey data, job loss is associated with elevated levels of self-reported financial risk-taking and lottery ticket purchases. Next, using administrative data from a large bank, we find consistent causal evidence of the influence of job loss on gambling spending. Although total spending decreases after job loss, gambling spending is less affected than our control categories. Finally, we turn to two incentive-compatible manipulations of job loss operationalized in a lab setting. We find that this experimental manipulation increases the take-up of financial risks. The current finding that job loss increases financial risk-taking could accentuate long-term negative financial effects of job loss.

Fast-chargeable lithium-ion batteries by μ-Si anode-tailored full-cell design

Silicon (Si) anodes have long been recognized to significantly improve the energy density and fast-charging capability of lithium-ion batteries (LIBs). However, the implementation of these anodes in commercial LIB cells has progressed incrementally due to the immense volume change of Si across its full state-of-charge (SOC) range. Here, we report an anode-tailored full-cell design (ATFD), which incorporates micrometer-sized silicon (μ-Si) alone, for operation over a limited, prespecified SOC range identified as 30−70%. This range allows homogeneous (de)lithiation throughout the electrode, accompanied by an acceptable level of volume change. The ATFD-based cell exhibits 21.3% higher gravimetric energy density than that of its graphite-based counterpart in a commercial 18650 cylindrical cell and 84.6% capacity retention after 500 cycles even at a fast-charging rate of 3 C. This study indicates that the partial, intermediate SOC operation of the μ-Si anode can markedly increase the energy density and boost the fast-charging capability of a LIB cell, a challenging task in traditional cell engineering.

Personality differences between birth order categories and across sibship sizes

We examined associations of self-reports on the HEXACO Personality Inventory—Revised (HEXACO-PI-R) with birth order category and sibship size, controlling for participant sex and age. In a first sample ( N &gt; 700,000 online adults, mainly from English-speaking countries), Honesty-Humility and Agreeableness both showed the highest means for middle-borns, followed in order by last-borns (youngests), firstborns (oldests), and only children, with differences between middles and onlys of d ≥ 0.20. The same result was replicated in a similar but smaller second sample ( N &gt; 70,000) in which sibship size was also assessed, thereby allowing birth order differences to be separated from sibship size differences. In that sample, Honesty-Humility and Agreeableness showed higher means with larger sibship sizes, with differences between sibship sizes of 1 and 6+ of d = 0.30 and d = 0.36, respectively. Controls for upbringing religiousness and current religiousness reduced these differences by about 25%. Within sibship sizes, birth order differences in these dimensions were considerably smaller but oldests remained up to d = 0.10 lower than middles and youngests. Openness was d ≈ 0.10 higher for onlys than for non-onlys collectively, and within sibship sizes, Openness was d ≈ 0.10 higher for oldests than for middles and youngests.

Correction for Ritz et al., Social anxiety disorder-associated gut microbiota increases social fear

Correction for Bartesaghi et al., Inhibition of oxidative metabolism leads to p53 genetic inactivation and transformation in neural stem cells