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bioRxiv2025

Adaptation of motor control strategies and physiological arousal during repeated blocks of split-belt walking

Physiological arousal, mediated by the autonomic nervous system (ANS), is known to co-modulate with adaptation of motor control strategies, governed by the central nervous system (CNS), in response to repeated standing perturbations. However, adaptation of the ANS physiological arousal response during repeat exposure to walking challenges remains unknown. This study examines the physiological arousal response (electrodermal activation, EDA) and motor control strategy of gait during a single session of repeated exposure to blocks of split-belt walking. Twenty young adults completed three repeated blocks (3.5 min each) of split-belt walking (2:1 speed ratio) alternating with three blocks of tied-belt walking. Step length symmetry (SLS), EDA, bilateral tibialis anterior (TA) and gastrocnemius medialis (GM) muscle activation and ground reaction forces (GRFs) were measured. For each walking block, the first (early) and last (late) 15 strides were analyzed. A linear mixed-effects model (LMM) tested the effect of repeated blocks and phases (early/late) on SLS. Statistical parametric mapping (SPM) examined patterns of within-block changes in EDA, muscle activation, and GRFs. The greatest within-block adaptation of SLS occurred during first exposure to split-belt walking (S1; p<.001). Similarly, the largest magnitude of within-block adaptation in muscle activation, GRFs, and EDA occurred during S1 (p<.05). Attenuated EDA responses together with lower magnitude of motor adaptation in subsequent split blocks 2 and 3 were observed, indicating savings across the ANS and CNS. Taken together, these findings demonstrate that the ANS-mediated physiological arousal response modulates alongside the CNS-driven locomotor adaptation to repeated exposure to blocks of split-belt walking.

neuroscience↗

bioRxiv2025

From human joints to bioreactor setups: quantifying mechanical stimuli in cartilage physiology and regeneration

ObjectiveBioreactors are widely used to apply mechanical stimuli to osteochondral (OC) explants and cartilage tissue-engineered (TE) constructs, yet their ability to replicate native joint mechanics is not well quantified. This study benchmarks common bioreactor loading protocols against a finite element (FE) model of the human knee during gait, enabling direct comparison to physiologically relevant mechanical parameters. MethodsA validated FE model of the human knee joint simulating the stance phase of gait was used to characterize physiological mechanical conditions, including maximum principal stress, maximum shear strain, pore pressure, and fluid velocity. These outputs were compared with those generated by representative bioreactor setups: dynamic unconfined compression (10-30%) and combined compression (10%) with ball rotation ({+/-}25{degrees}), which were applied to both OC plugs and TE constructs, and hydrostatic pressure (0.5-50 MPa), which was applied only to TE constructs. FE simulations evaluated spatial and magnitude-based agreement with native cartilage mechanics. ResultsIn OC plugs, 10% unconfined compression generated maximum principal stresses ([~]7.5 MPa) and pore pressures ([~] 4 MPa) closely matching native tissue ([~] 4.5 MPa and [~]5 MPa, respectively). In TE constructs, even at 30% unconfined strain, maximum principal stresses and pore pressures remained around 100 times lower than physiological values, while fluid velocities were 10 times higher. Hydrostatic loading of TE constructs at 5 MPa matched native pore pressures ([~]5 MPa) but induced negligible strains. ConclusionsThis study provides a quantitative framework for evaluating how well bioreactor loading regimens replicate physiological joint mechanics. The findings offer actionable guidance to experimentalists for selecting bioreactor conditions based on specific mechanical targets. This can lead to more effective design of in vitro cartilage studies and support translational strategies in cartilage repair and tissue engineering.

bioengineering↗

bioRxiv2025

Physiological diversity and adaptation of Rhizaria revealed by phylogenomics and comparative transcriptomics

Protists are vastly diverse, forming over 20 supergroups of the eukaryotic diversity and fulfilling plentiful functions. Rhizaria is a widespread and highly abundant supergroup comprising important parasites and a huge diversity of free-living heterotrophic predators. Despite the diversity and biogeochemical importance of Rhizaria, our understanding of their physiology and metabolic capabilities remains limited, mainly due to a general lack of data and bioinformatic tools for cross-species comparisons of physiological traits. In this study, we assembled a total of 15 transcriptomes of the parasite-related bacterivorous Rhogostoma and their eukaryvorous relatives. By phylogenomic analyses and whole transcriptome comparison, we established an evolutionary framework to which we relate physiological traits. The morphologically highly similar Rhogostoma strains branch in two distinct clusters differing in orthogroups and gene expression patterns related to cell adhesion and biofilm formation. Furthermore, we reveal considerable intra-genus variation in amino acid and lipid metabolism, which might be explained by an ancient streamlining through gradual specialization to parasitism, bearing the potential for subsequent metabolic radiation. We conclude that even closely related and morphologically similar species in Rhizaria may differ distinctly in their functional repertoire. With the here established and showcased analyses, we create a basis for future characterization of the physiological traits of microeukaryotes.

microbiology↗

bioRxiv2017

Degeneracy in hippocampal physiology and plasticity

Degeneracy, defined as the ability of structurally disparate elements to perform analogous function, has largely been assessed from the perspective of maintaining robustness of physiology or plasticity. How does the framework of degeneracy assimilate into an encoding system where the ability to change is an essential ingredient for storing new incoming information? Could degeneracy maintain the balance between the apparently contradictory goals of the need to change for encoding and the need to resist change towards maintaining homeostasis? In this review, we explore these fundamental questions with the mammalian hippocampus as an example encoding system. We systematically catalog lines of evidence, spanning multiple scales of analysis, that demonstrate the expression of degeneracy in hippocampal physiology and plasticity. We assess the potential of degeneracy as a framework to achieve the conjoint goals of encoding and homeostasis without cross-interferences. We postulate that biological complexity, involving interactions among the numerous parameters spanning different scales of analysis, could establish disparate routes towards accomplishing these conjoint goals. These disparate routes then provide several degrees of freedom to the encoding-homeostasis system in accomplishing its tasks in an input- and state-dependent manner. Finally, the expression of degeneracy spanning multiple scales offers an ideal reconciliation to several outstanding controversies, through the recognition that the seemingly contradictory disparate observations are merely alternate routes that the system might recruit towards accomplishment of its goals. Against the backdrop of the ubiquitous prevalence of degeneracy and its strong links to evolution, it is perhaps apt to add a corollary to Theodosius Dobzhanskys famous quote and state \"nothing in physiology makes sense except in the light of degeneracy\".\n\nHighlightsO_LIDegeneracy is the ability of structurally distinct elements to yield similar function\nC_LIO_LIWe postulate a critical role for degeneracy in the emergence of stable encoding systems\nC_LIO_LIWe catalog lines of evidence for the expression of degeneracy in the hippocampus\nC_LIO_LIWe suggest avenues for research to explore degeneracy in stable encoding systems\nC_LIO_LIDobzhansky wrote: \"nothing in biology makes sense except in the light of evolution\"\nC_LIO_LIA corollary: \"nothing in physiology makes sense except in the light of degeneracy\"\nC_LI

neuroscience↗

bioRxiv2018

Physiomarkers in Real-Time Physiological Data Streams Predict Adult Sepsis Onset Earlier Than Clinical Practice

Rationale: Sepsis is a life-threatening condition with high mortality rates and expensive treatment costs. To improve short- and long-term outcomes, it is critical to detect at-risk sepsis patients at an early stage.\n\nObjective: Our primary goal was to develop machine learning models capable of predicting sepsis using streaming physiological data in real-time.\n\nMethods: A dataset consisting of high-frequency physiological data from 1,161 critically ill patients admitted to the intensive care unit (ICU) was analyzed in this IRB-approved retrospective observational cohort study. Of that total, 634 patients were identified to have developed sepsis. In this paper, we define sepsis as meeting the Systemic Inflammatory Response Syndrome (SIRS) criteria in the presence of the suspicion of infection. In addition to the physiological data, we include white blood cell count (WBC) to develop a model that can signal the future occurrence of sepsis. A random forest classifier was trained to discriminate between sepsis and non-sepsis patients using a total of 108 features extracted from 2-hour moving time-windows. The models were trained on 80% of the patients and were tested on the remaining 20% of the patients, for two observational periods of lengths 3 and 6 hours.\n\nResults: The models, respectively, resulted in F1 scores of 75% and 69% half-hour before sepsis onset and 79% and 76% ten minutes before sepsis onset. On average, the models were able to predict sepsis 210 minutes (3.5 hours) before the onset.\n\nConclusions: The use of robust machine learning algorithms, continuous streams of physiological data, and WBC, allows for early identification of at-risk patients in real-time with high accuracy.

bioinformatics↗

bioRxiv2018

Orchestration of Drosophila post-feeding physiology and behavior by the neuropeptide leucokinin

Behavior and physiology are orchestrated by neuropeptides acting as neuromodulators and/or circulating hormones. A central question is how these neuropeptides function to coordinate complex and competing behaviors. The neuropeptide leucokinin (LK) modulates diverse functions, including circadian rhythms, feeding, water homeostasis, and sleep, but the mechanisms underlying these complex interactions remain poorly understood. Here, we delineate the LK circuitry that governs homeostatic functions that are critical for survival. We found that impaired LK signaling affects diverse but coordinated processes, including regulation of stress, water homeostasis, locomotor activity, and metabolic rate. There are three different sets of LK neurons, which contribute to different aspects of this physiology. We show that the calcium activity of abdominal ganglia LK neurons (ABLKs) increases specifically following water consumption, but not under other conditions, suggesting that these neurons regulate water homeostasis and its associated physiology. To identify targets of LK peptide, we mapped the distribution of the LK receptor (Lkr), mined brain single-cell transcriptome dataset for genes coexpressed with Lkr, and utilized trans-synaptic labeling to identify synaptic partners of LK neurons. Lkr expression in the brain insulin-producing cells (IPCs), gut, renal tubules and sensory cells, and the post-synaptic signal in sensory neurons, correlates well with regulatory roles detected in the Lk and Lkr mutants. Furthermore, these mutants and flies with targeted knockdown of Lkr in IPCs displayed altered expression of insulin-like peptides (DILPs) in IPCs and modulated stress responses. Thus, some effects of LK signaling appear to occur via DILP action. Collectively, our data suggest that the three sets of LK neurons orchestrate the establishment of post-prandial homeostasis by regulating distinct physiological processes and behaviors such as diuresis, metabolism, organismal activity and insulin signaling. These findings provide a platform for investigating neuroendocrine regulation of behavior and brain-to-periphery communication.

neuroscience↗

bioRxiv2019

A High-Throughput Physiological Functional Phenotyping System for Time- and Cost-Effective Screening of Potential Biostimulants

The improvement of crop productivity under abiotic stress is one of the biggest challenges faced by the agricultural scientific community. Despite extensive research, the research-to-commercial transfer rate of abiotic stress-resistant crops remains very low. This is mainly due to the complexity of genotype{square}x{square}environment interactions and in particular, the ability to quantify the dynamic plant physiological response profile to a dynamic environment.\n\nMost existing phenotyping facilities collect information using robotics and automated image acquisition and analysis. However, their ability to directly measure the physiological properties of the whole plant is limited. We demonstrate a high-throughput functional phenotyping system (HFPS) that enables comparing plants dynamic responses to different ambient conditions in dynamic environments due to its direct and simultaneous measurement of yield-related physiological traits of plants under several treatments. The system is designed as one-to-one (1:1) plant-[sensors+controller] units, i.e., each individual plant has its own personalized sensor, controller and irrigation valves that enable (i) monitoring water-relation kinetics of each plant-environment response throughout the plants life cycle with high spatiotemporal resolution, (ii) a truly randomized experimental design due to multiple independent treatment scenarios for every plant, and (iii) reduction of artificial ambient perturbations due to the immobility of the plants or other objects. In addition, we propose two new resilience-quantifying-related traits that can also be phenotyped using the HFPS: transpiration recovery rate and night water reabsorption.\n\nWe use the HFPS to screen the effects of two commercial biostimulants (a seaweed extract--ICL-SW, and a metabolite formula--ICL-NewFo1) on Capsicum annuum under different irrigation regimes. Biostimulants are considered an alternative approach to improving crop productivity. However, their complex mode of action necessitates cost-effective pre-field phenotyping. The combination of two types of treatment (biostimulants and drought) enabled us to evaluate the precision and resolution of the system in investigating the effect of biostimulants on drought tolerance. We analyze and discuss plant behavior at different stages, and assess the penalty and trade-off between productivity and survivability. In this test case, we suggest a protocol for the screening of biostimulants physiological mechanisms of action.

plant biology↗

bioRxiv2019

Design of a comprehensive microfluidic and microscopic toolbox for the ultra-wide spatio-temporal study of plant protoplasts development and physiology

BackgroundOne of the main features of plant cells is their strong plasticity, and their propensity to regenerate an organism from a single cell. Plant protoplasts are basic plant cells units in which the pecto-cellulosic cell wall has been removed, but the plasma membrane is intact. One of the main features of plant cells is their strong plasticity, which in some species, can be very close from what is defined as cell totipotency. Methods and differentiation protocols used in plant physiology and plant biology usually involve macroscopic vessels and containers that make difficult, for example, to follow the fate of the same protoplast all along its full development cycle, but also to perform continuous studies of the influence of various gradients in this context. These limits have hampered the precise study of regeneration processes. ResultsHerein, we present the design of a comprehensive, physiologically relevant, easy-to-use and low-cost microfluidic and microscopic setup for the monitoring of Physcomitrella patens (P. patens) growth and development on a long-term basis. The experimental solution we developed is made of two parts (i) a microfluidic chip composed of a single layer of about a hundred flow-through microfluidic traps for the immobilization of protoplasts, and (ii) a low-cost, light-controlled, custom-made microscope allowing the continuous recording of the moss development in physiological conditions. We validated the experimental setup with three proofs of concepts: (i) the kinetic monitoring of first division steps and cell wall regeneration, (ii) the influence of the photoperiod on growth of the protonemata, and (iii) finally the induction of leafy buds using a phytohormone, cytokinin. ConclusionsWe developed the design of a comprehensive, physiologically relevant, easy-to-use and low-cost experimental setup for the study of P. patens development in a microfluidic environment. This setup allows imaging of P. patens development at high resolution and over long time periods.

plant biology↗

bioRxiv2019

Differential characterization of physiological and biochemical responses during drought stress in finger millet varieties

Drought is the most perilous abiotic stress that affects finger millet growth and productivity worldwide. For the successful production of finger millet, selection of drought tolerant varieties is necessary and critical stages under drought stress, germination and early seedling growth, ought to be fully understood. This study investigated the physiological and biochemical responses of six finger millet varieties (GBK043137, GBK043128, GBK043124, GBK043122, GBK043094 and GBK043050) under mannitol-induced drought stress. Seeds were germinated on sterile soil and irrigated with various concentrations of mannitol (200, 400 and 600 mM) for two weeks. Comparative analysis in terms of relative water content (RWC), chlorophyll, proline, and malondialdehyde (MDA) contents were measured the physiological and biochemical characteristics of drought stress. The results showed that increased level of drought stress seriously decreased germination and early seedling growth of finger millet varieties. However, root growth was increased. In addition, exposition to drought stress triggered a significant decrease in relative water content and chlorophyll content reduction the biochemical parameters assay showed less reduction of relative water content. Furthermore, oxidative damage indicating parameters such as proline concentration and MDA content increased. Varieties GBK043137 and GBK043094 were less affected by drought as shown by significant change in the physiological parameters. Our findings reveal the difference and linkage between the physiological responses of finger millet to drought and are vital for breeding and selection of drought tolerant varieties of finger millet. Further investigations on genomic and molecular to deeply insight the detail mechanisms of drought tolerance in finger millet need to explored.

plant biology↗

bioRxiv2019

Interactions in milk suggest a physiological role for β-lactoglobulin

{beta}-Lactoglobulin is the most abundant protein in the whey fraction of ruminant milks, yet is absent in human milk. It has been studied intensively due to its impact on the processing and allergenic properties of ruminant milk products. However, the physiological function of {beta}-lactoglobulin remains unclear. Sedimentation velocity experiments have identified new interactions between fluorescently-labelled {beta}-lactoglobulin and other components in milk. Co-elution experiments support that these {beta}-lactoglobulin interactions occur naturally in milk and provide evidence that the interacting partners are immunoglobulins, while further sedimentation velocity experiments confirm that an interaction occurs between these molecules. Ruminants (e.g. cows and goats) are born without circulating immunoglobulins, which they must obtain from their mothers milk, whilst humans obtain immunoglobulins both through milk and during gestation via the placenta. We propose that {beta}-lactoglobulin serves to protect immunoglobulins within ruminant milk during digestion, ensuring their efficient transfer from mother to offspring.\n\nStatement of Significance{beta}-Lactoglobulin is an abundant protein in the whey fraction of ruminant milks (e.g. cow and goat milk), yet it is completely absent in human milk. While this protein has been extensively studied, due to its impact on the processing and allergenic properties of milk, its physiological function remains unclear. We fluorescently labelled {beta}-lactoglobulin to monitor its interactions with other milk components within its physiological environment, milk. Under these near physiological conditions {beta}-lactoglobulin is capable of interacting with several classes of immunoglobulins. Immunoglobulins are susceptible to digestion, but are required to confer immunity from the mother to the offspring. We propose that {beta}-lactoglobulin serves to protect immunoglobulins within ruminant milk during digestion, ensuring their efficient transfer from mother to offspring.

biophysics↗

bioRxiv2019

Behavioral and physiological evidence that increasing group size ameliorates the impacts of social disturbance

Intra-group social stability is important for the long-term productivity and health of social organisms. We evaluated the effect of group size on group stability in the face of repeated social perturbations using a cooperatively breeding fish, Neolamprologus pulcher. In a laboratory study, we compared both the social and physiological responses of individuals from small versus large groups to the repeated removal and replacement of the most dominant group member (the breeder male). Individuals living in large groups were overall more resistant to instability but were seemingly slower to recover from perturbation. Members of small group were more vulnerable to instability but recovered faster. Breeder females in smaller groups also showed greater physiological preparedness for instability following social perturbations. In sum, we recover both behavioral and physiological evidence that living in larger groups helps to dampen the impacts of social instability in this system.\n\nSO_SCPLOWUMMARYC_SCPLOW SO_SCPLOWTATEMENTC_SCPLOWSocial stability is vital for group productivity and long-term persistence. Here, both behavioral and physiological evidence conveys that larger groups are less susceptible to social disturbance.

animal behavior and cognition↗

bioRxiv2019

Throwing shade: Physiological responses to light explain competition and facilitation in a tree diversity experiment

O_LIEcologists often invoke interspecific facilitation to help explain positive biodiversity-ecosystem function relationships in plant communities, but seldom test how it occurs. One mechanism through which one species may facilitate another is by ameliorating abiotic stress. Physiological experiments show that a chronic excess of light can cause stress that depresses carbon assimilation. If shading by a plants neighbors reduces light stress enough, it may facilitate that plants growth. If light is instead most often a limiting factor for photosynthesis, shading may have an adverse, competitive effect. C_LIO_LIIn a temperate tree diversity experiment, we measured stem growth rates and photosynthetic physiology in broadleaf trees across a gradient of light availability imposed by their neighbors. At the extremes, trees experienced nearly full sun (monoculture), or were shaded by nearby fast-growing conifers (shaded biculture). C_LIO_LIMost species had slower growth rates with larger neighbors, implying a net competitive effect. On the other hand, the two most shade-tolerant species (Tilia americana and Acer negundo) and the most shade-intolerant one (Betula papyrifera) had faster stem growth rates with larger neighbors. The two most shade-tolerant species had large increases in photoinhibition (reduced dark-acclimated Fv/Fm) across the gradient of increasing light availability, which suggests they are more vulnerable to chronic light stress. While most species had lower carbon assimilation rates in the shaded biculture treatment, T. americana had rates up to 25% higher. T. americana also dropped its leaves 3-4 weeks earlier in monocultures, curtailing its growing season. We conclude that although large neighbors can cause light limitation in shade-intolerant species, they can also increase growth through abiotic stress amelioration in shade-tolerant species. Finally, in shade-intolerant B. papyrifera, we find a pattern of stem elongation in trees with larger neighbors, which may suggest that a shade avoidance response accounts for the apparent positive trend in stem volume. C_LIO_LISynthesis: Both positive and negative species interactions in our experiment can be explained in large part by the photosynthetic responses of trees to the light environment created by their neighbors. We show that photosynthetic physiology can help explain the species interactions that underlie biodiversity-ecosystem function relationships. The insights that ecologists gain by searching for such physiological mechanisms may help us forecast species interactions under environmental change. C_LI

ecology↗

bioRxiv2019

Unveiling the physiological mechanisms that drive the emergence of antibiotic resisters from antibiotic persister population of mycobacteria

The physiological mechanisms behind the emergence of antibiotic-resistant bacteria from their antibiotic-persister population are beginning to be explored. Here we delineate the sequential physiological events that drive the emergence of rifampin-resistant rpoB mutants from rifampin-persister population of mycobacteria during prolonged exposure. The rifampin-persister population generated elevated levels of hydroxyl radical, which inflicted mutations, enabling regrowth of the persister cells to form multi-septated, multi-nucleated elongated cells. These cells, through multiple divisions, produced multiple sister-daughter cells, causing an abrupt, unexpectedly high increase of rifampin-resistant colonies. Similar response was observed against moxifloxacin also. Earlier studies on the rifampin/moxifloxacin-exposed laboratory/clinical M. tuberculosis strains from in-vitro cultures and infected mouse-lung also showed cfu spurt, but went unnoticed/unreported. It is likely that these sequential physiological events may be driving the emergence of antibiotic-resistant tubercle bacilli in TB patients also. Escherichia coli also has been found to respond similarly against subminimal inhibitory concentrations of ciprofloxacin. Thus, the present findings attain broad significance as a general physiological mechanism used by diverse bacterial genera to emerge as drug-resistant strains against antibiotics.

microbiology↗

bioRxiv2025

Physiologically Relevant 3D CRISPR Screening Enhances Mechanistic Insight into Chemical Toxicity Compared to 2D Screening

Many omics-based approaches in toxicology research primarily rely on correlative data, often lacking functional relationships or causal links between genotypes and phenotypes. CRISPR-based approaches can overcome this limitation by establishing direct causal connections between genes and toxicological phenotypes. Moreover, CRISPR screens enable scalable and systematic interrogation of gene function and associated mechanisms following chemical exposure, predominantly using in vitro models. In line with the paradigm of new approach methodologies (NAMs) in toxicology research, CRISPR screens hold promise to provide an in vitro cell-based functional toxicogenomics approach. One of the main limitations of conventional in vitro assays is their compromised physiological relevance to humans due to their inability to fully recapitulate in vivo physiology. To improve the functional and physiological relevance of the toxicogenomics approach, we developed a 3D CRISPR screening system using HepG2/C3A spheroids generated and cultivated in a continuously rotating bioreactor (ClinoStar). We first performed time-course 3D CRISPR screens to identify genes that confer growth disadvantage or advantage, influencing spheroid development compared to 2D cultures. We then applied this approach to a chemical toxicity study using doxorubicin, comparing the performance of the 3D and 2D systems in identifying chemical-specific mechanisms. The results showed that the 3D system captured more candidate genetic determinants and biological pathways related to DNA damage processes--a known toxicity mechanism of doxorubicin--demonstrating improved performance in identifying chemical-specific pathways over the 2D counterpart. In our screens, we employed custom CRISPR sgRNA libraries representing common human loss-of-function genetic variants (mean allele frequency > 0.1% in all individuals catalogued in the genome aggregation database), which potentially affect toxicity responses. By comparing our CRISPR screen results with previously reported genetic associations for doxorubicin response, we found that the 3D system identified more known associated genes than the 2D system. Together, the 3D CRISPR screening system demonstrated its feasibility and utility for physiologically relevant functional toxicogenomics. This platform enables in vitro NAMs, by providing a scalable and effective approach to identify causal genetic determinants and biological pathways that modulate chemical-induced toxicity.

pharmacology and toxicology↗

bioRxiv2025

Neuropeptide F regulates adult female response to diet, larval locomotion and several larval physiological processes in Lucilia cuprina cuprina

The blowfly Lucilia cuprina dorsalis is a highly detrimental ectoparasite of sheep responsible for causing flystrike, a condition that can result in severe morbidity and potentially lead to death if left untreated. In contrast, Lucilia cuprina cuprina is necrophagous and not a pest. We have been interested in identifying the genes that may play a role in the evolution of a parasitic lifestyle in blowflies. The objective of the present work was to explore the physiological role of the L. cuprina long neuropeptide F gene (LcNPF) in L. c. cuprina. We used CRISPR/Ca9 to generate a strain carrying a loss-of-function knock-in mutation for LcNPF. An RNA-Seq analysis was performed, and physiological and behavioral assays were conducted to evaluate the role of LcNPF in larvae and adult flies. Our findings indicate that functional disruption of the LcNPF gene significantly impairs egg hatching, larval survival, weight gain, crawling speed and larval time to pupariation. These phenotypic changes were corroborated by RNA-Seq analysis, which revealed downregulation of transcripts in LcNPF null mutated larvae associated with the respective physiological processes. In contrast, the foraging behavior of the larvae under the tested conditions was not affected. Interestingly, NPF appears to be essential for the oviposition preference of females for rotten meat but not for male mating behavior or fertility. Our results suggest that NPF signaling plays a central regulatory role in multiple physiological processes across both the larval and adult stages. Highlights{square} A loss-of-function knock-in mutation of the LcNPF gene was obtained using CRISPR/Cas9. {square}LcNPF-homozygous mutant larvae showed decreased weight gain, locomotion and survival on rotten meat. {square}Disruption of the LcNPF gene eliminated the female preference for oviposition in rotten meat. {square}LcNPF does not appear to be essential for normal fertility or male mating behavior as homozygotes were comparable to wild type

molecular biology↗

bioRxiv2025

Empathy Accelerates Subjective Time Perception, Independent of Physiology but Not of Visual Attention

Recent work suggests that empathic engagement can influence cognitive and perceptual processes, yet its impact on time perception remains unclear. Whereas internal clock models would predict that empathy-induced physiological arousal lengthen perceived duration, other frameworks offer opposite predictions. Specifically, findings that empathy reduces perceived distance, combined with construal level, and motivational dimensional theory, together predict that empathy accelerate the subjective passage of time. Moreover, although eye-movements are crucial in empathy, it remains unclear how visual attention modulates time perception during empathic experiences. Thus, we employed an empathy-for-pain and duration estimation task, while measuring participants heart rate, skin conductance, and eye-movements, to investigate how empathy and physiological arousal influence time perception. Our findings show that empathy leads to a faster perceived passage of time. Despite increases in physiological arousal during empathy, arousal was not associated with changes in time perception. Instead, greater visual attention to the eyes predicted stronger temporal contraction. Furthermore, trait empathy and autism quotient were related to this effect, whereas alexithymia was not. These results provide the first empirical evidence that empathy alters time perception, elucidate the contribution of physiological and visual mechanisms to this phenomenon and extend current theories of time perception and empathy.

neuroscience↗

bioRxiv2026

One-Pot NADH-Mediated Physiological Redox-Controlled Synthesis of Papain-Stabilized Copper Nanoclusters with Preserved Bioactivity for Efficient Drug Delivery

Protein-protected copper nanoclusters are promising candidates for bioimaging and therapeutic applications. However, harsh reducing conditions required for their synthesis, compromising the proteins structural integrity and bioactivity. Here, we report a one-pot, physiologically compatible aqueous synthesis for papain-protected copper nanoclusters (Pap-CuNCs) with blue photoluminescence and excellent photostability using nicotinamide adenine dinucleotide (NADH) as a biological reducing agent. The mild conditions (ambient temperature, neutral pH) enable the simultaneous formation of a metallic Cu0 core while stabilizing the helical content of the protein. This approach introduces a physiologically redox-controlled strategy for nanocluster formation, establishing physiological redox chemistry as a governing principle for controlling nanoscale structure and protein conformational stability. Spectroscopic and microscopic studies have demonstrated the presence of crystalline nanoclusters with a protein corona that undergoes -helical stabilization as revealed by circular dichroism. Notably, atomistic simulation studies reveal preferential binding of the copper core in the proteins active site, enhancing the -helical content of papain, consistent with experimental observations. Functionally, the Pap-CuNCs possess biocompatibility and serve as an effective delivery platform for 5-fluorouracil, leading to a 50-fold decrease in IC50 for HeLa cells without causing cytotoxicity to normal cells. This establishes a generalizable framework for bio-integrated nanocluster design under biologically compatible conditions. TOC Text O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=44 SRC="FIGDIR/small/719779v1_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@1ca9292org.highwire.dtl.DTLVardef@5cd82aorg.highwire.dtl.DTLVardef@173ed2forg.highwire.dtl.DTLVardef@1d8c30c_HPS_FORMAT_FIGEXP M_FIG C_FIG NADH-mediated physiological redox synthesis of papain-stabilized copper nanoclusters with enhanced -helical stability. This bio-integrated nanoplatform facilitates drug loading and delivery, resulting in a [~]50-fold increase in cytotoxicity in cancer cells while maintaining excellent biocompatibility toward normal cells.

bioengineering↗

bioRxiv2026

Classification of Smartphone Interaction Using Multimodal Physiological Signals with a Brain-Body Spatio-Temporal Transformer

Distinct smartphone interaction behaviors, like short-form video scrolling and mobile gaming, elicit qualitatively different cognitive and physiological responses. However, such distinctions is often overlooked by approaches that treat smart-phone use as a monolithic behavior. This paper presents Brain-Body Spatio-Temporal Transformer (BB-STT), a unified deep learning framework for classifying interaction-specific physiological signatures from multimodal signals, including EEG, EDA, PPG, and eye-tracking. BB-STT achieves 83.51% accuracy in distinguishing smartphone from non-smartphone activity and 74.13% accuracy in three-class classification of short-form video, gaming, and baseline viewing. The model demonstrates strong generalization with leave-one-subject-out (LOSO) performance that is also comparable to 5-fold cross-validation accuracy. Cross-modal attention emerges as the key component, improving three-class accuracy by 16.74 points through dynamic integration of multimodal signals. Interpretability analysis indicates a hierarchical organization of physiological responses. Eye-tracking features, particularly gaze depth, enable coarse separation between smartphone and non-smartphone activity. In contrast, finer discrimination between passive video viewing and active gaming on smartphones relies on the joint contribution of bilateral pupil dilation and central EEG features. Together, these results demonstrate the potential of multimodal physiological signals for objective, real-time assessment of digital engagement in naturalistic settings.

neuroscience↗