Paul Hernandez Herrera

Paul Hernandez Herrera
Universidad Nacional Autónoma de México | UNAM · Departamento de Ingeniería Celular y Biocatálisis

Doctor of Philosophy

About

20
Publications
2,695
Reads
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148
Citations
Additional affiliations
January 2018 - present
Universidad Nacional Autónoma de México
Position
  • PostDoc Position
Description
  • Desarollo de algoritmos computacionales para la segmentación de celulas
January 2016 - December 2017
Universidad Autónoma del Estado de Morelos
Position
  • PostDoc Position
Description
  • Desarrollo de algoritmos computacionales para el análisis automático del espermatozoide humano
August 2015 - December 2015
Universidad Nacional Autónoma de México
Position
  • PostDoc Position

Publications

Publications (20)
Preprint
Due to the wave nature of light, optical microscopy has a lower-bound lateral resolution limit of about half of the wavelength of the detected light, i.e., within the range of 200 to 300 nm. The Fluorescence Fluctuation based Super Resolution Microscopy (FF-SRM) encompases a collection of image analysis techniques which rely on the statistical proc...
Article
Arabidopsis (Arabidopsis thaliana) primary and lateral roots are well suited for 3D and 4D microscopy, and their development provides an ideal system for studying morphogenesis and cell proliferation dynamics. With fast-advancing microscopy techniques used for live-imaging, whole tissue data are increasingly available, yet present the great challen...
Article
Intracellular Ca2+ is a key regulator of cell signaling and sperm are not the exception. Cells often use cytoplasmic Ca2+ concentration ([Ca2+]i) oscillations as a means to decodify external and internal information. [Ca2+]i oscillations faster than those usually found in other cells and correlated with flagellar beat were the first to be described...
Article
Full-text available
Human spermatozoa are the archetype of long-time self-organizing transport in nature, and critical for reproductive success. They utilize the coordinated head and flagellar movements to swim long distances within the female reproductive tract in order to find and fertilize the egg. However, to this date, long-time analysis of the sperm head-flagell...
Article
The reiterative process of lateral root (LR) formation is widespread and underlies root system formation. However, early LR primordium (LRP) morphogenesis is not fully understood. In this study, we conducted both a clonal analysis and time-lapse experiments to decipher the pattern and sequence of pericycle founder cell (FC) participation in LR form...
Article
Full-text available
Flagellar beating drives sperm through the female reproductive tract and is vital for reproduction. Flagellar waves are generated by thousands of asymmetric molecular components; yet, paradoxically, forward swimming arises via symmetric side-to-side flagellar movement. This led to the preponderance of symmetric flagellar control hypotheses. However...
Article
Full-text available
We describe an experimental system based on optical microscopy, permitting the analysis of the four dimensional structure of the flow inside evaporating sessile droplets by monitoring the motion of tracers in horizontal planes localized at different heights. Inter-plane particle identification is accomplished via 3D tracking algorithms. The multipl...
Preprint
Full-text available
The canonical beating of the human sperm flagellum is postulated to be symmetric. This is despite the reported asymmetries inherent to the flagellar axonemal structure, from distribution and activation of molecular motors to, even, the localisation of regulatory ion channels. This raises a fundamental question: how symmetric beating is possible wit...
Article
Tracing tubular structures from biomedical images is important for a wide range of applications. Particularly, the spermatozoon is an essential cell whose flagella has a tubular form. Its main function is to fertilize the egg and the flagellum is fundamental to achieve this task which depends importantly on the dynamics of intracellular calcium ([C...
Conference Paper
Full-text available
Desarrollamos un sistema experimental, basado en microscopía óptica, con el objetivo de analizar la dinámica tridimensional de la evaporación de una gota de agua cargada de partículas fluorescentes. Este sistema cuenta con un dispositivo piezoeléctrico que hace que el objetivo de un microscopio óptico suba y baje de forma controlada mientras una cá...
Article
Full-text available
Despite the significant advances in the development of automated image analysis algorithms for the detection and extraction of neuronal structures, current software tools still have numerous limitations when it comes to the detection and analysis of dendritic spines. The problem is especially challenging in in vivo imaging, where the difficulty of...
Article
Study question: Are there intracellular Ca2+ ([Ca2+]i) oscillations correlated with flagellar beating in human sperm? Summary answer: The results reveal statistically significant [Ca2+]i oscillations that are correlated with the human sperm flagellar beating frequency, when measured in three-dimensions (3D). What is known already: Fast [Ca2+]i...
Conference Paper
We present an experimental and numerical study of the flow inside an evaporating sessile drop of water. The drop volume analyzed ranges from 0.3 to 1 microliters and the range of footprint radii is from 0.5 to 1 mm. The observations of the velocity field are obtained with an experimental device designed to monitor the motion of tracers at a number...
Conference Paper
Intracellular calcium ([Ca\(^{2+}\)]i) regulates sperm motility. Visualizing [Ca\(^{2+}\)]i in 3D is not a simple matter since it requires complex fluorescence microscopy techniques where the resulting images have very low intensity and consequently low SNR (Signal to Noise Ratio). In 3D+t sequences, this problem is magnified since the flagellum be...
Article
AbstractBackground High resolution multiphoton and confocal microscopy has allowed the acquisition of large amounts of data to be analyzed by neuroscientists. However, manual processing of these images has become infeasible. Thus, there is a need to create automatic methods for the morphological reconstruction of 3D neuronal image stacks. New metho...
Article
Full-text available
The challenges faced in analyzing optical imaging data from neurons include a low signal-to-noise ratio of the acquired images and the multiscale nature of the tubular structures that range in size from hundreds of microns to hundreds of nanometers. In this paper, we address these challenges and present a computational framework for an automatic, t...
Conference Paper
Background: High resolution multiphoton and confocal microscopy has allowed the acquisition of large amounts of data to be analyzed by neuroscientists. However, manual processing of these images has become infeasible. Thus, there is a need to create automatic methods for the morphological reconstruction of 3D neuronal image stacks. New method: A...
Chapter
Full-text available
After highlighting some of the current trends in neuroscience imaging, this work studies the approximation errors due to varying directional aliasing, arising when 2D or 3D images are subjected to the action of orthogonal transformations. Such errors are common in 3D images of neurons acquired by confocal microscopes. We also present an algorithm f...

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Projects

Project (1)
Project
We develop software that provides tools to record and analyse the three-dimensional evaporation dynamics of a sessile particle laden water droplet.