Browse Articles

Identifying fish populations prone to abrupt shifts via dynamical footprint analysis

Fish population biomass fluctuates through time in ways that may be either gradual or abrupt. While abrupt shifts in fish population productivity have been shown to be common, they are rarely integrated into stock assessment or fishery management, in part because of the difficulty of predicting when abrupt shifts may occur and which stocks are prone to such shifts. In this study, we address the latter challenge by designing a mechanism-agnostic context-specific approach that is based on exploiting the dynamical properties of fish population fluctuations for detecting potential abrupt shifts. We use time series of fish population biomass from three global datasets, first, to classify their shapes into abrupt and nonabrupt (linear, quadratic, or no change) classes, and, second, to predict classified shapes based only on their dynamical footprint (a set of metrics such as variance, autocorrelation, etc, of the time series). We find that populations prone to abrupt shifts can be detected with moderate accuracy in the three datasets in spite of data limitations. In total, we identified 50 populations at risk of future abrupt shifts across 11 different Large Marine Ecosystem regions. Our context-specific approach offers critical insights into population stability and enables the identification of stocks whose dynamical properties suggest that they would benefit from more precautionary management.

Erythrocyte membrane lipid profile in children and adolescents with metabolic dysfunction-associated steatotic liver disease and insulin resistance: a preliminary study

Transient oxygenation of the Mediterranean after the Zanclean megaflood

The Mediterranean basin reconnected to the Atlantic Ocean ~5.33 Myr ago, following its partial desiccation during the preceding Messinian salinity crisis (5.97 to 5.33 Myr). While the extent of terminal Messinian drawdown and abruptness of reconnection are debated, recent work inferred that an anomalously long-lasting eastern Mediterranean organic-rich “mystery sapropel” layer was deposited due to salinity-stratification and anoxia following catastrophic flooding that refilled the basin. However, independent evidence is required to test this hypothesis. Here, we present extensive proxy data and numerical model results to show that irrespective of the largely hypersaline or oligohaline conditions proposed for the terminal Messinian, the eastern Mediterranean became oxygenated due to the ~1.5-km-high, turbulent and aerated cascade that refilled the basin, which created a salinity-stratified but oxygenated water column that allowed preservation of only the most recalcitrant organic components. Next, oxygen was gradually depleted over a period of up to 12,000 y due to remineralization of sinking organic matter, culminating in a stratified, anoxic basin. It took 33,000 y after flooding (7,000 y longer than suggested previously) for turbulent diffusion to weaken the stratification and allow resumption of convective deep-water renewal, which marked the final return of normal oxygenated marine conditions throughout the Mediterranean.

Revealing the protective potential of D-(-)-Quinic acid against thioacetamide-induced hepatic encephalopathy in rats

Germline variants in <i>UHRF1</i> are associated with multilocus imprinting disturbance in humans and mice

The investigation of congenital imprinting disorders (CIDs) provides opportunities to elucidate the molecular mechanisms and role of genomic imprinting in development and human disease. Beckwith–Wiedemann spectrum (BWSp) is a prototypic CID resulting from genetic and epigenetic alterations of imprinted genes at chromosome 11p15.5. In up to a quarter of individuals with BWSp, the epigenetic alterations are not confined to 11p15.5 imprinting control regions but also involve other imprinted gene clusters (multilocus imprinting disturbance; MLID). In a consanguineous family with two children diagnosed with BWSp and MLID, the affected individuals were homozygous for a missense variant in UHRF1 , a gene previously implicated in the maintenance of DNA methylation. To investigate whether the UHRF1 c. 2001G&gt;C, p.(Lys667Asn) missense substitution predisposes to abnormal establishment/maintenance of genomic imprinting patterns, a genetically engineered mouse model with a Uhrf1 p.(Lys661Asn) variant was developed. Mice homozygous for the variant born to heterozygous mothers did not display an abnormal phenotype, but homozygotes born to healthy homozygous mothers displayed a range of phenotypes including prenatal lethality. Also, MLID was observed in affected mouse embryos. These findings are consistent with biallelic UHRF1 variants in affected individuals resulting in an autosomal recessively inherited cause of MLID in humans and expand the range of epigenetic disorders associated with UHRF1.

SpyShield: a Spyfall inspired defense mechanism against poisoning attacks in federated learning

Abstract Traditional machine learning (ML) relies on a centralized architecture, which makes it unsuitable for applications where data privacy is critical. Federated Learning (FL) addresses this issue by allowing multiple parties to collaboratively train models without sharing their raw data. However, FL is susceptible to data and model poisoning attacks that can severely disrupt the learning process. Existing literature indicates that defense mechanisms predominantly analyze client updates on the server side, often without requiring or involving client cooperation. This paper proposes a novel defense mechanism, SpyShield, that leverages client cooperation to identify malicious clients in data and model poisoning attacks. SpyShield is inspired by tactics used in the social deduction game Spyfall, where the majority of players must detect the deception of a minority, a dynamic aligning with the challenges posed by poisoning attacks in ML. In this paper, we evaluate four different configurations of SpyShield’s robustness and performance on the FashionMNIST dataset against five benchmark aggregation algorithms–FedAvg, Krum, Multi-Krum, Median, and Trimmed Mean–under three attack types: (A) Cyclic Label Flipping, (B) Random Label Flipping, and (C) Random Weight Attacks. Each attack is tested across three scenarios: (I) 3 malicious clients out of 30, (II) 10 out of 50, and (III) 40 out of 100, totaling nine experimental settings. These settings simulate varying attack intensities, allowing the assessment of SpyShield’s effectiveness under different attack invasiveness. In every setting, at least one configuration of SpyShield consistently outperformed all benchmark algorithms, achieving the highest accuracy. The evaluation shows that SpyShield achieves strong performance and resilience across diverse settings and attack types. These findings highlight its potential as a robust and generalizable defense mechanism for securing federated learning models, while also opening new possibilities for collaborative strategies that move beyond centralized server-side analysis.

Indigenous fire stewardship shaped North American Great Lakes forests

Interest in bringing Traditional Ecological Knowledge (TEK) and Western Science together to enhance climate and landscape resilience is growing rapidly, particularly for engagement with pyrogenic communities around the world. For these systems, Indigenous Knowledge offers unique insights that reflect millennia of intimate engagement with local landscapes, while Western Science can offer additional understanding of the emergence of climates and ecological conditions that are novel at evolutionary timescales. Here, we weave Indigenous Knowledge together with a multicentury history of fire, landuse, and forest development derived from tree rings to retell a more complete history of human engagement with the places commonly referred to as Wisconsin and Minnesota Points at the head of Lake Superior in the Laurentian Great Lakes. Our aim in this work is to create mutual reciprocal benefits for those involved in this work to disrupt a long history of extractive research and to honor the knowledge shared with us by reducing barriers to the revitalization of traditional cultural and landuse practices. This intensely local study, contextualized by substantial bodies of Indigenous Knowledge and Western Science, illustrates the importance of place-based and community-based research for understanding the role of Indigenous fire stewardship in shaping pine barrens sites and demonstrates how these fine-scale relationships are linked to regional landscape diversity yet may be invisible to other proxy-based studies. These results help (re)center Indigenous Knowledge and traditional fire-use practices in the process of ecocultural fire restoration for the creation of diverse, resilient, and just socioecological systems that continue to transition toward a warmer future.

Psychological safety and trust as drivers of teachers’ continued use of AI tools in classrooms

Long-term climate warming weakens positive plant biomass responses globally

Carbon sequestration through plant biomass responses to global warming plays a vital role in mitigating climate change, but recent evidence suggests that this effect diminishes in the long term. To investigate the effect of warming duration on plant biomass responses, we analyzed a global dataset of 2,291 paired observations, revealing that warming increased overall aboveground plant biomass by 9.4% and belowground biomass by 2.6%. However, as the warming duration increased, the positive plant biomass response shifted to neutral or negative, with great biomass reductions in regions where mean annual temperatures exceeded 10 °C. Global aboveground biomass is projected to decline by 4 to 16% under a 2 °C increase in climate warming. Our study suggests that long-term climate warming will significantly weaken plant carbon storage, even if temperature increases remain within the targets of the Paris Agreement, and offers empirical constraints for global biomass–climate models.

Exploring the self-care experiences of patients with rheumatoid arthritis through qualitative content analysis

COL4A1 as a potential prognostic biomarker with functional roles in colon cancer progression

Elucidating the role of <i>Campylobacter concisus</i> –derived indole metabolites in gut inflammation and immune modulation

The gut microbiota plays a pivotal role in maintaining human health with dysbiosis linked to a variety of diseases. Metagenome sequencing and robust statistical analysis have linked specific strains, including the gut bacterium Campylobacter concisus , to Crohn’s disease and ulcerative colitis, together known as inflammatory bowel disease (IBD). However, the roles of this and other strains in disease progression remain to be investigated. Herein, we assess the contribution of C. concisus secondary metabolites to inflammation. Through untargeted metabolomics, we identified a diverse array of nineteen indole-containing metabolites produced by C. concisus , including trisindoline, previously isolated from a marine bacterium. Collectively, these metabolites modulate inflammatory responses by significantly inducing the release of proinflammatory cytokines interleukin (IL)-1β, IL-6, IL-8, and MCP-1. The metabolites act through the aromatic hydrocarbon receptor arylhydrocarbon receptor and in vivo intravital imaging revealed a marked increase in the recruitment and activation of immune cells, specifically neutrophils and macrophages, following the administration of trisindoline. Several indole metabolites also exhibited antimicrobial activity against commensal strains that facilitate a proper immune response. Our study provides a possible rationale for the association of C. concisus with IBD and underscores the complex interplay between gut bacteria and host immunity. The identification of indole-derived secondary metabolites as key modulators of inflammation offers new avenues for therapeutic intervention.

The association between triglyceride–glucose index and the recurrence of myocardial infarction in young patients with previous coronary heart disease

CO ₂ upgrading into bioproducts using a two-step abiotic–biotic system

The valorization of CO 2 to chemicals beyond C 1-2 products is receiving significant interest; however, the direct electrosynthesis of C n molecules (n &gt; 4) remains a challenge. Here, we present a two-step abiotic–biotic system for upgrading CO 2 into the biopolymer, poly(3-hydroxybutyrate). In the electrolysis system, CO 2 is converted into C 2 oxygenates using a Cu–Ag tandem electrocatalyst. The electrolysis process generates a liquid stream containing ~ 200 mM acetate in a bio-compatible electrolyte. This electrosynthesized acetate is then fed to a bioreactor, where the substrate is upgraded by Cupriavidus necator to biopolymer with a maximum rate of 32 ± 3.5 mg L −1 h −1 . We further demonstrate the purification of the resulting biopolymer into a powder. The high productivity of the abiotic–biotic system demonstrates its feasibility for sustainable chemical manufacturing.

Progress and policies to achieve the zero pollution action plan and EU 2024/2881 PM2.5 targets in Northern Italy

Warming climate and water withdrawals threaten river flow connectivity in China

River flow connectivity, the continuity of fluvial discharge in space and time, provides a crucial lifeline for most biotic communities on Earth. Yet there is still limited understanding of the impacts of climate change and human water withdrawal on river connectivity. Here, we assess the river flow connectivity of 217,001 river reaches in mainland China from 1961 to 2020 and the impact of different climate warming trends and water withdrawals for different sectors. We estimate that naturally intermittent rivers represent about 13% of all river reaches, with a large contrast between northern and southern China (12% vs. 1%, respectively). Although river intermittency decreased slightly during this period (i.e., river connectivity lengthened due to increasing precipitation), warming temperatures offset this decrease by reducing surface water persistence, causing the decrease (−476 vs. −233 km/y) to double when removing the long-term temperature trend. Critically, the length of intermittent rivers increased remarkably from 13 to 50% when considering human water withdrawal by agricultural, domestic, and industrial sectors, in addition to environmental flow requirements. Our findings highlight the urgent need to maintain sustainable water resources in a warming climate in which unregulated water abstractions increasingly threaten river flow connectivity, particularly in drying regions.

The bacterial community of the freshwater bryozoan Cristatella mucedo and its secondary metabolites production potential

Interhemispheric resting-state functional connectivity correlates with spontaneous neural interactions

Functional connectivity (FC), a statistical correlation of pair-wise brain signals from resting-state (RS) functional MRI (fMRI), is a widely used concept for mapping large-scale functional networks in both humans and animals. However, its underlying causal mechanism remains poorly understood, particularly for strong interhemispheric connectivity (e.g., homotopic connections) consistently observed in FC. In this study, we investigated the neural basis of RS FC in mice using fMRI with anatomically defined patterned optogenetic activation and inhibition of excitatory neurons in six cortical regions. Unlike commonly used optogenetic activation, optogenetic silencing suppresses spontaneous neural activity in a localized region, reducing RS synaptic inputs to downstream networked areas. Consequently, fMRI can track spontaneous functional connections without the neural perturbations associated with excitation. While conventional optogenetic activation of excitatory neurons in the targeted cortical areas predominantly elicited their ipsilateral functional responses in both cortical and subcortical regions, optogenetic silencing induced both intra- and interhemispheric cortical responses, which were stronger than cortical-subcortical connections. These effects more closely resembled statistically defined RS FC patterns, providing insight into the underlying mechanisms of intrinsic FC. By modeling synaptic path length-dependent connectivity patterns based on structural connectivity (SC), we found that spontaneous functional connections can be explained by polysynaptic propagation, whereas evoked activity is largely restricted to monosynaptic pathways. These findings highlight the critical role of polysynaptic pathways in shaping spontaneous connectivity, suggesting that RS FC arises from causal interactions of spontaneous ongoing neural activity.

A robust fractional fuzzy decision support framework for sustainable energy planning

Climate variability amplifies the need for vector-borne disease outbreak preparedness

In locations that do not currently experience vector-borne disease (VBD) outbreaks but may be at risk under climate change, modeling future climate suitability for transmission is important for outbreak preparedness. Uncertainty in the future climate arises from three sources—differences in emissions scenarios, structural uncertainty across climate models, and internal climate variability (ICV)—but ICV is rarely considered in climate-VBD studies. Here, we demonstrate that ICV is a key source of uncertainty in climate suitability for VBD transmission, even decades into the future. Because of ICV, suitable climate conditions for transmission may arise in many locations sooner than expected under climate change alone.