Orexin and pupillary modulation for hunger control.

November 3, 2026| Source: Proceedings of the National Academy of Sciences of the United States of America

Fasting-based interventions improve metabolic health and are also explored as adjuncts in other clinical settings, but hunger remains a barrier to adherence. Fasting activates AgRP/NPY neurons (ANs), a hunger-promoting population whose inhibition reduces eating in hungry animals. Here we identify hypocretin/orexin neurons (HONs), classically associated with arousal, as rapid suppressors of AN activity. HON ablation increased AN population activity, whereas HON optostimulation rapidly suppressed it. Combined recordings of AN activity and pupil size-a direct arousal metric not previously linked to AN dynamics-revealed that HONs contributed to pupil dilation-associated AN suppression. In fasted mice, sensory stimulation rapidly recruited this pupil-HON pathway, and suppressed AN activity and eating. These findings reveal an arousal-hunger pathway through which self-initiated pupil dilations, or dilations driven by salient environmental events, interrupt fasting-induced hunger signals. They also suggest a framework for noninvasive, sensory-, and pupillometry-guided approaches to hunger control during fasting.

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Widespread plasma jets in the Martian magnetosheath revealed by dual-spacecraft observations.

Plasma jets in planetary magnetosheaths are transient, high dynamic pressure structures capable of strongly perturbing downstream magnetospheres and modulating solar wind energy transfer. Although recently identified at Mars, their formation mechanisms and global occurrence remain poorly constrained. Using dual-spacecraft observations from Mars Atmosphere and Volatile EvolutioN and Tianwen-1, we show that magnetosheath jets occur throughout the Martian magnetosheath, in striking contrast to Eart

EnvironmentNovember 3, 2026

Defining and measuring proximity to criticality based on univariate time series.

Diverse social, engineered, and biological systems are made up of multiple interacting dynamical components; to work properly, certain components must be carefully regulated so that their dynamics avoid instability. However, many desirable properties, like optimized computation and control, emerge close to the tipping point between stability and instability, i.e., near criticality. Claims that such dynamical systems operate near criticality have been controversial because it is difficult to asse

EnvironmentNovember 3, 2026

Environmental RNA improves detection and surveillance of schistosomiasis transmission.

Environmental diagnosis of schistosomiasis, a disease affecting over 250 million people globally, remains challenging, thereby limiting efficient eradication efforts. Current methods, including environmental DNA (eDNA), cannot distinguish between infectious parasite life stages present in the environment. Here, we develop and validate an environmental RNA (eRNA) approach that enables detection and quantification of Schistosoma mansoni miracidia (infective to snails) and cercariae (infective to h

EnvironmentOctober 29, 2026

Gram-Negative Bacterial Resistance.

The rapid worldwide spread of antimicrobial resistance among gram-negative bacteria is driven by a complex interplay of human, environmental, and health care-associated factors and accelerated by mobile genetic elements that facilitate the dissemination of resistance genes. Resistance in gram-negative bacteria arises primarily through reduced drug entry, active drug efflux, modification of antibiotic targets, and enzymatic drug inactivation, most notably through β-lactamase production. Cli

EnvironmentOctober 27, 2026

Nutrient legacies from elephant megacarcasses create coldspots of biodiversity and hotspots of ecosystem processes.

Terrestrial megafauna (animals >1,000 kg) have substantial impacts on ecosystems while alive; yet, we know little about the impacts of these ecosystem engineers after they die. Like whale carcasses in the ocean, terrestrial megacarcasses may leave ecological legacies via the nutrient pulses they create on the landscape. Here, we investigated the impact of elephant megacarcasses on savanna ecosystems in Kruger National Park, South Africa. To determine how elephant carcasses affect below- and a