Biology subjects

Hayward, M.

Publications and source records attributed to Hayward, M..

7 recordsLinked to original sources

bioRxiv2026

Carnivores in a metropolitan forest island: first spatial capture-recapture estimates reveal high densities of leopards and striped hyenas in Jaipur, India

Urban protected areas (PAs) have become important habitats for wildlife in rapidly expanding human-dominated landscapes. These PAs may provide refuge and continuously abundant resources, which may enable some adaptable carnivores to persist and attain high abundances. However, little is known about the population ecology and interactions between carnivores sharing such spatially restricted and disturbed urban habitats. We evaluated the densities and spatio-temporal interactions of leopards (Panthera pardus) and striped hyenas (Hyaena hyaena) in Jhalana-Amagarh Conservation Reserve, a protected area (PA) embedded within the metropolis of Jaipur, India. During May-July 2025, we deployed 30 paired camera-traps and used spatially explicit capture-recapture models to estimate density and individual activity centres. We further quantified their diel activity and temporal overlap using kernel density estimation. Leopard density was estimated at 7.03 {+/-} 1.31 individuals/10 km sq and striped hyena density at 4.06 {+/-} 0.96 individuals/10 km sq, with activity centres of both species occurring in close proximity and frequently towards the reserve periphery. Both species were predominantly nocturnal and showed high temporal overlap ({Delta}4 = 0.801, CI=0.73-0.86). Our results report exceptionally high leopard and striped hyena densities in an urban PA and exemplify the importance of small PAs within rapidly expanding cities, stressing the need for finer-scale studies more broadly to understand the mechanisms shaping interactions between the two species. However, such systems require careful management of food subsidies, habitat quality and connectivity along with long-term monitoring of population viability, disease dynamics and human-wildlife conflict.

ecology↗

bioRxiv2026

Expert Motor Synergies Emerge Predominantly Offline During Early Skill Learning

Everyday skilled actions depend on the formation of coordinated motor synergies that integrate multiple digits into stable, low-dimensional control units. Although initial practice of a new skill leads to rapid performance improvements, it is unclear whether the underlying movement kinematics reorganize on a similar timescale and in a way that directly relates to these gains. It also remains uncertain whether such reorganization occurs mainly during active practice or instead during brief rest breaks. Here, we tracked the temporal evolution of multi-digit synergy formation during early learning of a naturalistic keypress skill. Initial practice rapidly sculpted the motor repertoire toward higher-order, temporally compressed and overlapping multi-digit synergies. These synergies emerged after only minutes of practice and continued to be expressed along the full training session. Notably, they were primarily shaped across brief rest breaks and robustly predicted individual skill proficiency. Across learning, distinct synergy subtypes emerged, differing in their heuristic prevalence. Rarely expressed synergies reflected transient novice patterns, synergies expressed at intermediate levels could index exploratory and trial-initiation strategies, and highly expressed synergies emerged later to dominate performance, reflecting the consolidation and expansion of skilled motor control. Together, these findings indicate that skilled performance is supported by the early formation of a compact repertoire of expert multi-digit synergies that emerge preferentially across rest periods and predict subsequent skill gains. They further raise the hypothesis that explicitly training such expert synergies alongside task goals could enhance learning in domains such as the arts, sport, and neurorehabilitation. HighlightsExpert multi-digit synergies form during early skill learning Higher-order synergies emerge across brief rest breaks Fatigue spares expert synergy use during early learning Skill gains mirror multi-digit synergy expression eTOC blurb"Expert multi-digit synergies emerge early in motor learning, strengthen across brief rest breaks, track skill gains, and resist fatigue"

neuroscience↗

bioRxiv2023

Fish on the platter! Investigating the dietary habits of fishing cats (Prionailurus viverrinus) in the Godavari Delta, India

The threatened fishing cat (Prionailurus viverrinus) is an elusive and medium-sized cat that is adapted to mangroves, swamps, wetlands, and riverine habitats. A close look at the literature indicates that fishing cats are piscivorous, however this is based on very few studies. Understanding the patterns of resource utilisation by species is crucial for assessing their role in ecosystems and in ensuring their conservation. Therefore, our study presents insights into fishing cat feeding patterns from mangroves of the Godavari delta, Andhra Pradesh, India. We collected 303 putative fishing cat scats and conducted analysis using 120 genetically identified scats. Our analysis revealed that fish was the most important prey by fishing cats in the study area, followed by crabs and rodents. The prey composition did not vary significantly between the three seasons but there were differences between the survey years. The niche breadth also varied across the three seasons, from being a generalist in winters to a specialist in summers. Our results suggest that long term conservation and survival of the fishing cats depends on fish populations, which are the main prey of the species and thus recommend the need to protect the fish populations in the Godavari delta and the surrounding riverine habitats. Given the importance of fish to the diet of the fishing cat, the health of waterways throughout their distribution must be one of the focal strategies of conservation action.

ecology↗

bioRxiv2023

Gut microbiota and metabolites drive chronic sickle cell disease pain

Pain is a debilitating symptom and leading reason for hospitalization of individuals with sickle cell disease. Chronic sickle cell pain is poorly managed because the biological basis is not fully understood. Using transgenic sickle cell mice and fecal material transplant, we determined that the gut microbiome drives persistent sickle cell pain. In parallel patient and mouse analyses, we identified bilirubin as one metabolite that induces sickle cell pain by altering vagus nerve activity. Furthermore, we determined that decreased abundance of the gut bacteria Akkermansia mucinophila is a critical driver of chronic sickle cell pain. These experiments demonstrate that the sickle cell gut microbiome drives chronic widespread pain and identify bacterial species and metabolites that should be targeted for chronic sickle cell disease pain management. One-Sentence SummaryGut microbes and metabolites drive chronic sickle cell disease pain by altering vagus nerve activity.

neuroscience↗

bioRxiv2022

A TYPE 2 INNATE LYMPHOID CELL-INTERLEUKIN 9 CIRCUIT INDUCES PANETH CELL METAPLASIA AND SMALL INTESTINAL REMODELING

Paneth cell metaplasia (PCM) typically arises in the setting of pre-existing gastrointestinal (GI) diseases; however, the mechanistic pathway that induces metaplasia and whether PCM is initiated exclusively by disorders intrinsic to the GI tract has not been delineated. Herein, we describe the development of PCM in a murine model of inducible bcr/abl oncogene-driven chronic myelogenous leukemia (CML) in which metaplasia is causally and temporally linked to the development of leukemia. Mechanistically, CML induced a proinflammatory state within the GI tract that resulted in the production of epithelial-derived IL-33. Binding of IL-33 to ST2 led to the production of IL-9 by type 2 innate lymphoid cells (ILC2s) which was directly responsible for the induction of PCM in the colon and Paneth cell hyperplasia in the ileum. In addition, IL-9 directed remodeling of the small intestines characterized by goblet and tuft cell hyperplasia along with the expansion of mucosal mast cells. Thus, we identify that an extra intestinal disease can trigger an ILC2/IL-9 immune circuit which induces PCM and regulates epithelial cell fate decisions in the GI tract.

immunology↗

bioRxiv2022

Tuft cells mediate commensal remodeling of the small intestinal antimicrobial landscape

Succinate produced by the commensal protist Tritrichomonas musculis (T. mu) stimulates chemosensory tuft cells, resulting in intestinal type 2 immunity. Tuft cells express the succinate receptor SUCNR1, yet this receptor does not mediate anti-helminth immunity nor alter protist colonization. Here, we report that microbial-derived succinate increases Paneth cell numbers and profoundly alters the antimicrobial peptide (AMP) landscape in the small intestine. Succinate was sufficient to drive this epithelial remodeling, but not in mice lacking tuft cell chemosensory components required to detect this metabolite. Tuft cells respond to succinate by stimulating type 2 immunity, leading to interleukin-13-mediated epithelial and AMP expression changes. Moreover, type 2 immunity decreases the total number of mucosa-associated bacteria and alters the small intestinal microbiota composition. These findings demonstrate that a single metabolite produced by commensals, like T. mu, can markedly shift the intestinal AMP profile and suggest that tuft cells utilize SUCNR1 to modulate bacterial homeostasis.

microbiology↗

bioRxiv2020

CRTC1-MAML2 Establishes a PGC1α-IGF1 Circuit that Confers Vulnerability to PPARγ Inhibition

Mucoepidermoid carcinoma (MEC) is a life-threatening salivary gland cancer that is driven primarily by the transcriptional co-activator fusion CRTC1-MAML2. The mechanisms by which the chimeric CRTC1-MAML2 oncoprotein rewires gene expression programs that promote tumorigenesis remain poorly understood. Here, we show that CRTC1-MAML2 induces transcriptional activation of the non-canonical PGC-1 splice variant PGC-14, which regulates PPAR{gamma}-dependent IGF-1 expression. This mitogenic transcriptional circuitry is consistent across cell lines and primary tumors. CRTC1-MAML2 positive tumors are dominated by IGF-1 pathway activation and small molecule drug screens reveal that tumor cells harboring the fusion gene are selectively sensitive to IGF-1R inhibition. Furthermore, this dependence on autocrine regulation of IGF-1 transcription renders MEC cells susceptible to PPAR{gamma}inhibition with inverse agonists. These results yield insights into the aberrant co-regulatory functions of CRTC1-MAML2 and identify a specific vulnerability that can be exploited for precision therapy.

cancer biology↗