Biology subjects

Barrio, R. A.

Publications and source records attributed to Barrio, R. A..

6 recordsLinked to original sources

bioRxiv2026

A dispersal model for Cenchrus setaceus (Poaceae) in Mexican urban context

Urban environments suffer from multiple ecological issues, such as the invasion of alien. In Mexico, Cenchrus setaceus (African fountain grass) has been introduced as an ornamental species in the 1990s spreading all around the country. The aim of the present study is to propose an invasion models, based on the temporal dispersion of C. setaceus seeds using field data from the metropolitan area of Guadalajara, Jalisco, distinguished between planted individuals from self-propagated ones, quantifying seeds fertility ex situ. Model indicate that the current infested area of the Guadalajara metropolitan area could reach 51-89% within 100 years. Applied to three cities in Chiapas, the model shows limited spread over 50-year period from existing foci but strong sensitivity to new ornamental introductions. An analysis of containment strategies estimates an invasion front velocity of 0.13 km/year and identifies a 3-km-wide buffer zone as necessary to halt spread over a 25-year horizon.

ecology↗

bioRxiv2026

A mathematical model for the efficient control of the New World screwworm

An outbreak of New World screwworm has recently been spreading across Mexico, after more than 30 years of absence. The sterile insect technique, which consists of the massive release of sterilized males, has proven to be one of the most efficient methods for controlling the screwworm pest. However, given the limited number of sterile males available, improving the release strategy is critical. We propose a mathematical model of population dynamics adapted to the biology of Cochliomyia hominivorax and derive a feedback control function to determine the number of sterile males to release. We further construct a Luenberger observer to estimate wild fly populations from infected animal counts--the variable monitored by Mexican sanitary authorities--enabling field implementation of the control function. We show that eradication is achievable within approximately 60-100 weeks and that eradication time is governed primarily by the intrinsic biology of the system rather than by infestation magnitude. We then extend the model to a spatially explicit framework and show that when sterile male releases are applied at the outbreak focus and within a 120 km radius, eradication of the pest is attainable.

ecology↗

bioRxiv2025

Abnormal bioelectricity during unperturbed cancer growth. Part-I: electrical biopotentials, surface charge density, volumetric charge density, phase-field and Turing approach.

Understanding the abnormal cancer bioelectricity and its close relationship to growth is a challenge for researchers and oncologists. The objective of this study is to simulate the mechanical-electrical coevolution of solid cancer using an energetic approach, which involves the local and global changes of bioelectricity in the entire unperturbed tumor, aspects that may be correlated spatially and electrically with the growth, progression, nucleation, angiogenesis and metastasis of a unperturbed solid malignant tumor. For this, spherical harmonics, phase-field, and the Turing approach were taken into account in the model. The results showed that electrical bioptentials and volumentric charge density throughout the interior of the unperturbed tumor, as well as surface charge density at tumor-surrounding healthy tissue boundary during its growth depended on mass aggregation, time and type of spherical harmonics. Regions with both positive and negative charge densities throughout the interior of the unperturbed tumor volume were observed. We concluded that positive and negative values may be responsible for maintaining the electronegativity of the entire tumor, primarily within it, during its growth over time. It is concluded that the anomalous bioelectricity and biomechanics in unperturbed cancer are due to intratumoral electrical heterogeneity and anisotropy according to {Phi}1(r,{theta} , {varphi}),{rho} v(t),{sigma} 12 and Turing spatiotemporal patterns, depending on the degree of Ynm asymmetry, {micro}T value [Formula] and t. Anomalous bioelectricity and biomechanics are closely related and both should be considered as another hallmark of cancer because these are essentially involved in self-regulation of symmetry, global electronegativity, intratumoral biological heterogeneity and anisotropy, growth, metastasis (by electrostatic and/or electromagnetic repulsion), abnormal metabolism of unperturbed cancer, as well as its protection from attack by cellular elements of the immune system and anticancer therapies (by formation of a heterogeneous electric shield), and in the appropriate and individualized selection of anticancer therapy, either alone or in combination. Author summaryUnperturbed cancer and its growth kinetics are not fully understood, an aspect that may partially explain why its complete cure has not yet been achieved by any existing anticancer therapies. This may be because the close electrical-mechanical-chemical-biological-kinetics-hallmarks connection in unperturbed cancer is not well understood. Therefore, this study proposes a theoretical approach that reveals the explicit connection between anomalous bioelectricity (electrical properties of cancer and surrounding healthy tissue, electrical biopotentials, surface charge density and volumetric charge density) with mechanical (phase-field, cancer asymmetry degree and diffusive interface), chemical-biological (Turing approach) and kinetic (size, geometry and introduction of mass) parameters in unperturbed cancer. Simulations reveal: 1) this electrical-mechanical-chemical-biological-kinetics-hallmarks connection may be essentially governed by both electronegative and electropositive intratumoral regions, which are closely interconnected and dependent on spherical harmonic asymmetry degree and introduction of mass (less than its threshold value) during unperturbed cancer growth. 2) Greater spherical harmonic asymmetry and amount of mass introduced result in a greater degree of heterogeneity and faster growth of it. 3) Electronegative and electropositive intratumoral regions may be responsible for the self-preservation and self-regulation overtime of symmetry of electric potential and volumetric charge density spatial patterns, both global electronegativity and survival of unperturbed cancer.

cancer biology↗

bioRxiv2020

Behavioral role of PACAP signaling reflects its selective distribution in glutamatergic and GABAergic neuronal subpopulations

The neuropeptide PACAP, acting as a co-transmitter, increases neuronal excitability, which may enhance anxiety and arousal associated with threat conveyed by multiple sensory modalities. The distribution of neurons expressing PACAP and its receptor, PAC1, throughout the mouse nervous system was determined, in register with expression of glutamatergic and GABAergic neuronal markers, to develop a coherent chemoanatomical picture of PACAPs role in brain motor responses to sensory input. A circuit role for PACAP was tested by observing fos activation of brain neurons after olfactory threat cue in wild type and PACAP knockout mice. Neuronal activation, and behavioral response, were blunted in PACAP knock-out mice, accompanied by sharply down-regulated vesicular transporter expression in both GABAergic and glutamatergic neurons expressing PACAP and its receptor. This report signals a new perspective on the role of neuropeptide signaling in supporting excitatory and inhibitory neurotransmission in the nervous system within functionally coherent polysynaptic circuits.

neuroscience↗

bioRxiv2020

Spatio-temporal analyses of OCT4 expression and fate transitions in human embryonic stem cells

OCT4 is one of the transcription factors required to maintain an undifferentiated state in human embryonic stem cells (hESCs). Thus, it is crucial to understand how OCT4 transcription is regulated both at the single-cell and colony level. Here we analyse the changes of OCT4-mCherry intensity expression in hESCs in the presence and absence of the BMP4 morphogenetic protein. We show that OCT4 expression is dynamic, reaching a maximum response 10 h after BMP4 treatment. We obtain the stationary probability distributions that govern the hESCs transitions amongst the different cell states in the presence/absence of BMP4 and establish the times at which the hESCs, that lead to differentiated and pluripotent cells, cluster in the colony. Furthermore, by quantifying the similarities between the OCT4 expression amongst neighbouring hESCs, we show that hESCs express, on average, similar values in their local neighbourhood within the first two days of the experiment and before BMP4 treatment. These results are relevant for the development of mathematical and computational models of adherent hESC colonies.

biophysics↗

bioRxiv2017

A biophysical dynamic module for the polarisation of auxin efflux carriers PIN-FORMED (PIN)

Intracellular polarisation of auxin efflux carriers is crucial for understanding how auxin gradients form in plants. The polarisation dynamics of auxin efflux carriers PIN-FORMED (PIN) depends on both biomechanical forces as well as chemical, molecular and genetic factors. Biomechanical forces have shown to affect the localisation of PIN transporters to the plasma membrane. We proposed a biophysical module of PIN polarisation that integrates biomechanical, molecular, and cellular processes as well as their non-linear interactions. The module was implemented as a discrete Boolean model and then approximated to a continuous dynamic system, in order to explore the relative contribution of the factors mediating PIN polarisation at the scale of single cell. Our models recovered qualitative behaviours that have been experimentally observed and enabled us to postulate that, in the context of PIN polarisation, the effects of the mechanical forces can predominate over the activity of molecular factors such as the GTPase ROP6 and the CRIB-motif CRIB-motif RIC1.

plant biology↗