We experimentally study Stochastic Resonance in an artificial neuron and demonstrate that pink noise amplifies the input signal
considerably—up to twenty times more—compared to white noise. The experimental results are consistent with biological
observations and theoretical calculations. Possible applications include the design of electro-optical devices.
@article{IOP,
abstract = {We experimentally study Stochastic Resonance in an artificial neuron and demonstrate that pink noise amplifies the input signal considerably—up
to twenty times more—compared to white noise. The experimental results are consistent with biological observations
and theoretical calculations. Possible applications include the design of electro-optical devices.
},
author = {Alexandra Pinto},
doi = {10.1088/2631-8695/ab8442},
openaccess = {https://doi.org/10.1088/2631-8695/ab8442},
pdf = {https://iopscience.iop.org/article/10.1088/2631-8695/ab8442},
title = {Pink noise amplifies stochastic resonance in neural circuits},
year = {2021}
}
Some systems cannot be predicted by classical theories and require the development of combined deterministic and stochastic
theories that make use of noise for their dynamical prediction. Noise is not always an interfering signal which
perturbs the system, it can also enhance its performance. This property can be observed through Stochastic Resonance
(SR), To detect this phenomena it is necessary a system with bistable potential barrier with a threshold, the input of
the system should be a weak periodic signal which amplitude is below threshold together with a stochastic signal. The
behaviour of the SR is detected in a neural network and it is studied under noise color variations. Here it is found
that Pink noise amplifies the sub-threshold input signal twenty times more in comparison to white noise. This could be
evidence of the functionality of background noise in the brain, where neurons are naturally embedded in pink noise.
@article{adsabs,
abstract = {Some systems cannot be predicted by classical theories and require the development of combined deterministic and stochastic theories that make use of noise for their dynamical prediction. Noise is not always an interfering signal which perturbs the system, it can also enhance its performance. This property can be observed through Stochastic Resonance (SR), To detect this phenomena it is necessary a system with bistable potential barrier with a threshold, the input of the system should be a weak periodic signal which amplitude is below threshold together with a stochastic signal. The behaviour of the SR is detected in a neural network and it is studied under noise color variations. Here it is found that Pink noise amplifies the sub-threshold input signal twenty times more in comparison to white noise. This could be evidence of the functionality of background noise in the brain, where neurons are naturally embedded in pink noise.},
author = {Pinto Alexandra},
doi = {10.13140/RG.2.2.25576.26887},
openaccess = {https://ui.adsabs.harvard.edu/abs/2018arXiv181006731P},
pdf = {https://arxiv.org/pdf/1810.06731.pdf},
title = {Stochastic Resonance in Neural Network, Noise Color Effects},
year = {2018}
}
This paper describes the model for DNA in MATLAB taking into account all of component atoms. In this model, it is possible to
generate sequences with length 10000 basis pairs available for introducing all types of sequences. Once the strands are
generated, it is studied the DNA damage in the single strand and double strand. The damage are outcomes of ionising
radiation of X-rays when interacting with the DNA immersed in water. This is a theoretical and experimental in-vitro
study that quantifies the single strand and double strand damage for different doses of radiation. This can be useful to
predict the exact risks of expositions to radiations. In simulations, it is taken into account the damage caused by free
electrons generated by the effect of the interaction with the water molecules, this is different to the effect considered
in radiobiology, where indirect damages are due to chemical reactions. The spatial distribution of the electrons is
obtained from Geant4 and here this distribution is used for the creation of rays as three-dimensional random trajectories
through Monte Carlo simulations. It is also presented the experimental DNA damage through radiating DNA samples immersed
in water with a X-rays unit with Molybdenum target. The damage level is quantified through Atomic Force Microscopy (AFM).
It is possible to conclude a direct relation between the damage and the radiation doses with the experimental results.
@article{physics.med-ph,
abstract = {This paper describes the model for DNA in MATLAB taking into account all of component atoms. In this model, it is possible to generate sequences
with length 10000 basis pairs available for introducing all types of sequences. Once the strands are generated, it is
studied the DNA damage in the single strand and double strand. The damage are outcomes of ionising radiation of X-rays
when interacting with the DNA immersed in water. This is a theoretical and experimental in-vitro study that quantifies
the single strand and double strand damage for different doses of radiation. This can be useful to predict the exact
risks of expositions to radiations. In simulations, it is taken into account the damage caused by free electrons
generated by the effect of the interaction with the water molecules, this is different to the effect considered in
radiobiology, where indirect damages are due to chemical reactions. The spatial distribution of the electrons is
obtained from Geant4 and here this distribution is used for the creation of rays as three-dimensional random
trajectories through Monte Carlo simulations. It is also presented the experimental DNA damage through radiating DNA
samples immersed in water with a X-rays unit with Molybdenum target. The damage level is quantified through Atomic
Force Microscopy (AFM). It is possible to conclude a direct relation between the damage and the radiation doses with
the experimental results.},
author = {Pinto Alexandra},
doi = {10.13140/RG.2.2.25576.26887},
openaccess = {arXiv:1810.05815},
pdf = {https://ui.adsabs.harvard.edu/abs/2018arXiv181005815P},
title = {Simulation and experimental verification of the DNA damage due to X-rays interaction},
year = {2018}
}
Published Version (Open Access)
PDF (Preprint)
Alexandra Pinto Castellanos (2017)Coupled Oscillators as a model of Olfactory Network. Importance in Pattern Recognition and Classification tasks
In adsabs
The olfactory system is constantly solving pattern-recognition problems by the creation of a large space to codify odour
representations and optimizing their distribution within it. A model of the Olfactory Bulb was developed by Z. Li and
J. J. Hopfield Li and Hopfield (1989) based on anatomy and electrophysiology. They used nonlinear simulations observing
that the collective behavior produce an oscillatory frequency. Here, we show that the Subthreshold hopf bifurcation is a
good candidate for modeling the bulb and the Subthreshold subcritical hopf bifurcation is a good candidate for modeling
the olfactory cortex. Network topology analysis of the subcritical regime is presented as a proof of the importance of
synapse plasticity for memory functions in the olfactory cortex.
@article{adsabs,
abstract = {The olfactory system is constantly solving pattern-recognition problems by the creation of a large space to codify odour representations and
optimizing their distribution within it. A model of the Olfactory Bulb was developed by Z. Li and J. J. Hopfield Li
and Hopfield (1989) based on anatomy and electrophysiology. They used nonlinear simulations observing that the
collective behavior produce an oscillatory frequency. Here, we show that the Subthreshold hopf bifurcation is a good
candidate for modeling the bulb and the Subthreshold subcritical hopf bifurcation is a good candidate for modeling
the olfactory cortex. Network topology analysis of the subcritical regime is presented as a proof of the importance
of synapse plasticity for memory functions in the olfactory cortex.},
author = {Pinto Alexandra},
doi = {10.13140/RG.2.2.25576.26887},
openaccess = {arXiv:1905.06307},
pdf = {https://ui.adsabs.harvard.edu/abs/2019arXiv190506307P},
title = {Coupled Oscillators as a model of Olfactory Network. Importance in Pattern Recognition and Classification tasks},
year = {2017}
}
Neurons have the capability of transforming information from a digital signal at the dendrites of the presynaptic terminal to
an analogous wave at the synaptic cleft and back to a digital pulse when they achieve the required voltage for the
generation of an action potential at the postsynaptic neuron. The main question of this research is what processes are
generating the oscillatory wave signal at the synaptic cleft and what is the best model for this phenomenon. Here, it
is proposed a model of the synapse as an oscillatory system capable of synchronization taking into account conservation
of information and consequently of frequency at the interior of the synaptic cleft. Trains of action potentials
certainly encode and transmit information along the nervous system but most of the time neurons are not transmitting
action potentials, 99 percent of their time neurons are in the sub threshold regime were only small signals without the
energy to emanate an action potential are carrying the majority of information. The proposed model for a synapse,
smooths the train of action potential and keeps its frequency. Synapses are presented here as a system composed of an
input wave that is transformed through interferometry. The collective synaptic interference pattern of waves will
reflect the points of maximum amplitude for the density wave synaptic function were the location of the "particle" in
our case action potential, has its highest probability.
@article{physics.med-ph,
abstract = {Neurons have the capability of transforming information from a digital signal at the dendrites of the presynaptic termi- nal to an analogous
wave at the synaptic cleft and back to a digital pulse when they achieve the required voltage for the generation
of an action potential at the postsynaptic neuron. The main question of this research is what processes are
generating the oscillatory wave signal at the synaptic cleft and what is the best model for this phenomenon. Here,
it is proposed a model of the synapse as an oscillatory system capable of synchronization taking into account
conservation of information and consequently of frequency at the interior of the synaptic cleft. Trains of action
potentials certainly encode and transmit information along the nervous system but most of the time neurons are not
transmitting action potentials, 99 percent of their time neurons are in the sub threshold regime were only small
signals without the energy to emanate an action potential are carrying the majority of information. The proposed
model for a synapse, smooths the train of action potential and keeps its frequency. Synapses are presented here as
a system composed of an input wave that is transformed through interferometry. The collective synaptic interference
pattern of waves will reflect the points of maximum amplitude for the density wave synaptic function were the
location of the "particle" in our case action potential, has its highest probability.},
author = {Pinto Alexandra},
doi = {2018arXiv181008056P},
openaccess = {arXiv:1810.08056},
pdf = {https://ui.adsabs.harvard.edu/abs/2018arXiv181008056P},
title = {Wave to pulse generation. From oscillatory synapse to train of action potentials},
year = {2018}
}