Artificial and Natural Computation

Spatial tuning of cells in and around lateral geniculate nucleus of the cat: X and Y relay cells and perigeniculate interneurons.Y T So, and R ShapleyY T So, and R ShapleyPublished Online:01 Jan 1981https://doi.org/10.1152/jn.1981.45.1.107MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByReceptive field properties of cat perigeniculate neurons correlate with excitatory and inhibitory connectivity to LGN relay neuronsNeuroscience Research, Vol. 132Surround suppression and temporal processing of visual signalsHenry J. Alitto and W. Martin Usrey1 April 2015 | Journal of Neurophysiology, Vol. 113, No. 7Phase sensitivities, excitatory summation fields, and silent suppressive receptive fields of single neurons in the parastriate cortex of the catPhillip A. Romo, Chun Wang, Natalie Zeater, Samuel G. Solomon, and Bogdan Dreher1 October 2011 | Journal of Neurophysiology, Vol. 106, No. 4Suppression at High Spatial Frequencies in the Lateral Geniculate Nucleus of the CatM. J. Nolt, R. D. Kumbhani, and L. A. Palmer1 September 2007 | Journal of Neurophysiology, Vol. 98, No. 3Interspike Interval Analysis of Retinal Ganglion Cell Receptive FieldsDaniel L. Rathbun, Henry J. Alitto, Theodore G. Weyand, and W. Martin Usrey1 August 2007 | Journal of Neurophysiology, Vol. 98, No. 2Visual Response Properties of Burst and Tonic Firing in the Mouse Dorsal Lateral Geniculate NucleusMatthew S. Grubb, and Ian D. Thompson1 June 2005 | Journal of Neurophysiology, Vol. 93, No. 6Fixational instability and natural image statistics: Implications for early visual representations9 July 2009 | Network: Computation in Neural Systems, Vol. 16, No. 2-3The thalamic reticular nucleus: structure, function and conceptBrain Research Reviews, Vol. 46, No. 1Visual Cortex Neurons of Monkeys and Cats: Temporal Dynamics of the Spatial Frequency Response FunctionRobert A. Frazor, Duane G. Albrecht, Wilson S. Geisler, and Alison M. Crane1 June 2004 | Journal of Neurophysiology, Vol. 91, No. 6Comparison of different models of orientation selectivity based on distinct intracortical inhibition rulesVision Research, Vol. 44, No. 14Quantitative Characterization of Visual Response Properties in the Mouse Dorsal Lateral Geniculate NucleusMatthew S. Grubb, and Ian D. Thompson1 December 2003 | Journal of Neurophysiology, Vol. 90, No. 6Brainstem modulation of visual response properties of single cells in the dorsal lateral geniculate nucleus of cat22 July 2004 | The Journal of Physiology, Vol. 543, No. 2Linear mechanistic models for the dorsal lateral geniculate nucleus of cat probed using drifting-grating stimuli9 July 2009 | Network: Computation in Neural Systems, Vol. 13, No. 4Changes in response modulation of cat perigeniculate neurons related to EEG state and application of neuromodulatorsNeuroreport, Vol. 12, No. 4Specificity and Strength of Retinogeniculate ConnectionsW. Martin Usrey, John B. Reppas, and R. Clay Reid1 December 1999 | Journal of Neurophysiology, Vol. 82, No. 6Temporal aspects of neural coding in the retina and lateral geniculate9 July 2009 | Network: Computation in Neural Systems, Vol. 10, No. 4Mosaic Arrangement of Ganglion Cell Receptive Fields in Rabbit RetinaSteven H. Devries, and Denis A. Baylor1 October 1997 | Journal of Neurophysiology, Vol. 78, No. 4Delta frequency (1–4 Hz) oscillations of perigeniculate thalamic neurons and their modulation by lightNeuroscience, Vol. 51, No. 2Responses of cat horizontal cells to sinusoidal gratingsVision Research, Vol. 32, No. 6Analysis of recurrent inhibitory circuit in rat thalamus: Neurophysiology of the thalamic reticular nucleusProgress in Neurobiology, Vol. 32, No. 2Modular organization of on and off responses in the cat lateral geniculate nucleusNeuroscience, Vol. 32, No. 3Representation of edges of variable blur by neuronal responses in the lateral geniculate body and the visual cortex of cats: Limits of linear predictionVision Research, Vol. 27, No. 10Abnormal Y/X ration in the area centralis of the siamese catBrain Research, Vol. 338, No. 2The receptive field organization of X-cells in the cat: Spatiotemporal coupling and asymmetryVision Research, Vol. 24, No. 6The effect of midbrain reticular stimulation upon perigeniculate neurons activity during different states of the sleep-waking cycle in the catBrain Research, Vol. 259, No. 2Electrophysiological study of the perigeniculate region during natural sleep in the catExperimental Neurology, Vol. 77, No. 2The Oblique Effects of Pattern and Flicker Sensitivity: Implications for Mixed Physiological Input25 June 2016 | Perception, Vol. 11, No. 4Receptive field properties of X and Y cells in the cat retina derived from contrast sensitivity measurementsVision Research, Vol. 22, No. 9 More from this issue > Volume 45Issue 1January 1981Pages 107-20 https://doi.org/10.1152/jn.1981.45.1.107PubMed6259298History Published online 1 January 1981 Published in print 1 January 1981 Metrics

Nucleus locus ceruleus: new evidence of anatomical and physiological specificity.

This chapter has the objective of describing the structure and placing in a taxonomy the Artificial Adaptive Systems (AAS). These systems form part of the vast world of Artificial Intelligence (AI) nowadays called more properly Artificial Sciences (AS). Artificial Sciences means those sciences for which an understanding of natural and/or cultural processes is achieved by the recreation of those processes through automatic models. In particular, Natural Computation tries to construct automatic models of complex processes, using the local interaction of elementary micro-processes, simulating the original process functioning. Such models organize themselves in space and time and connect in a non-linear way to the global process they are part of, trying to reproduce the complexity through the dynamic creation of specific and independent local rules that transform themselves in relation to the dynamics of the process. Natural Computation constitutes the alternative to Classical Computation (CC). This one, in fact, has great difficulty in facing natural/cultural processes, especially when it tries to impose external rules to understand and reproduce them, trying to formalize these processes in an artificial model. In Natural Computation ambit, Artificial Adaptive Systems are theories which generative algebras are able to create artificial models simulating natural phenomenon. The learning and growing process of the models is isomorphic to the natural process evolution, that is, it’s itself an artificial model comparable with the origin of the natural process. We are dealing with theories adopting the “time of development” of the model as a formal model of “time of process” itself. Artificial Adaptive Systems comprise Evolutive Systems and Learning Systems. Artificial Neural Networks are the more diffused and best-known Learning Systems models in Natural Computation.

Correlation of experimental and theoretical data for artificial and natural systems with immobilized biocatalysts

Control of thalamic transmission by corticofugal and ascending reticular pathways in the visual system.

Under aggressive environments, it was found the surfaces of concrete significantly tend to deteriorate with increasing the exposure time. The deterioration of concrete surface led to increase the crack's number, depth, and width which results in serious problems such as steel corrosion. To improve concrete durability against the aggressive environments, several methods are adopted such as coating systems. Nanotechnology and nanomaterials are moving toward new frontiers and the design and fabrication of coating systems are one of the future challenges. This study provides an overview of concrete coating materials at the nanoscale, organized in three main sections. First phase recalls some interesting strategies of coating processes in natural systems which show sophisticated, elegant, and efficient repairing mechanisms. Second phase reviewed the nanomaterials which can be grouped, according to their preparation methods and type of materials such as nano SiO2, Al2O3, and TiO2. We evidence in particular the advantages brought by nanotechnology in this field, for instance by means of nanoparticles or nanostructured patterns. Third phase deals with advantage of nanomaterials and efficiency of coating materials to reduce the concrete deterioration.KeywordsNanotechnologyDurable concreteSustainabilityCoatingsSteel corrosionNanosilica

Emulation of energy transfer processes in natural systems on quantum platforms can further our understanding of complex dynamics in nature. One notable example is the demonstration of vibrationally assisted energy transfer (VAET) on a trapped-ion quantum emulator, which offers insights for the energetics of light harvesting. In this work, we expand the study of VAET simulation with trapped ions to a non-Hermitian quantum system comprising a PT-symmetric chromophore dimer weakly coupled to a vibrational mode. We first characterize exceptional points (EPs) and non-Hermitian features of the excitation energy transfer processes in the absence of the vibration, finding a degenerate pair of second-order EPs. Exploring the non-Hermitian dynamics of the whole system including vibrations, we find that energy transfer accompanied by absorption of phonons from a vibrational mode can be significantly enhanced near such a degenerate EP. Our calculations reveal a unique spectral feature accompanying the coalescing of eigenstates and eigenenergies that provides a unique approach to probe the degenerate EP by fluorescence-detected vibrational spectroscopy. Enhancement of the VAET process near the EP is found to be due to maximal favorability of phonon absorption at the degenerate EP, enabling multiple simultaneous excitations. Our work on improving VAET processes in non-Hermitian quantum systems paves the way for leveraging non-Hermiticity in quantum dynamics related to excitation energy transfer. Published by the American Physical Society 2024

New conceptualisations of peri-urban zones are needed to trigger a deeper understanding within professionals and practitioners of appropriate intervention strategies that build the resilience of sustainable agriculture and food production within peri-urban communities. This paper posits a theoretical construction of the peri-urban zone, derived from applying a biomimicry framework. Biomimicry is the analysis of processes in natural systems to derive design principles for human systems. Insights are derived from mimicking two natural ecosystem types on Australia?s Sunshine Coast using the theoretical constructs of Chaos theory and patch dynamics to characterise peri-urban zones. This mimicry of dynamic complex ecosystems suggests the peri-urban zone be characterised as a spatially and temporally patchy community which is ?disturbance dominated?. The framework suggests the challenge for designing successional pathways for agriculture in peri-urban zones requires interventions based on five dynamic principles which explain not just natural system behaviour, but also characterise socio-economic processes.

Biocatalytic transformations in living organisms, such as multi-enzyme catalytic cascades, proceed in different cellular membrane-compartmentalized organelles with high efficiency. Nevertheless, it remains challenging to mimicking biocatalytic cascade processes in natural systems. Herein, we demonstrate that multi-shelled metal-organic frameworks (MOFs) can be used as a hierarchical scaffold to spatially organize enzymes on nanoscale to enhance cascade catalytic efficiency. Encapsulating multi-enzymes with multi-shelled MOFs by epitaxial shell-by-shell overgrowth leads to 5.8~13.5-fold enhancements in catalytic efficiencies compared with free enzymes in solution. Importantly, multi-shelled MOFs can act as a multi-spatial-compartmental nanoreactor that allows physically compartmentalize multiple enzymes in a single MOF nanoparticle for operating incompatible tandem biocatalytic reaction in one pot. Additionally, we use nanoscale Fourier transform infrared (nano-FTIR) spectroscopy to resolve nanoscale heterogeneity of vibrational activity associated to enzymes encapsulated in multi-shelled MOFs. Furthermore, multi-shelled MOFs enable facile control of multi-enzyme positions according to specific tandem reaction routes, in which close positioning of enzyme-1-loaded and enzyme-2-loaded shells along the inner-to-outer shells could effectively facilitate mass transportation to promote efficient tandem biocatalytic reaction. This work is anticipated to shed new light on designing efficient multi-enzyme catalytic cascades to encourage applications in many chemical and pharmaceutical industrial processes.

The future of energy supply depends on innovative breakthroughs regarding the design of cheap, sustainable, and efficient systems for the conversion and storage of renewable energy sources, such as solar energy. The production of hydrogen, a fuel with remarkable properties, through sunlight-driven water splitting appears to be a promising and appealing solution. While the active sites of enzymes involved in the overall water-splitting process in natural systems, namely hydrogenases and photosystem II, use iron, nickel, and manganese ions, cobalt has emerged in the past five years as the most versatile non-noble metal for the development of synthetic H(2)- and O(2)-evolving catalysts. Such catalysts can be further coupled with photosensitizers to generate photocatalytic systems for light-induced hydrogen evolution from water.

Chlorophenols (CPs) are a class of synthetic organic chemicals that are widely distributed in soil and groundwater, posing significant risks to human health and the environment due to persistence, acute toxicity, and potential carcinogenicity. Zero-valent iron (ZVI) has emerged as a promising remediation technique for CPs, but its efficacy is often hindered by surface passivation, non-target competition, and limited mobility in the subsurface. While CPs are inherently biodegradable, their high toxicity and the lack of functional enzymes in indigenous microbial systems restrict the effectiveness of bioremediation. Recently, a hybrid system integrating ZVI with microbial degradation draws increasingly research interests, paving out a new path for sustainable degradation of CPs. These systems leverage the synergistic interactions between ZVI and microorganisms to enhance CP biodegradation. This review provides a comprehensive analysis of the advancement. Key topics include the enhancement of electron transfer, alterations to microbial communities, mitigation of toxicity, and the interplay between other processes. Operation modes, ZVI dosage, and interactions with naturally occurring iron minerals, are also discussed in the context of applications in soil and groundwater remediation. Despite research efforts and successful implementations, critical knowledge gaps remain, particularly in regard to the characterization of microbial processes in natural systems, highlighting the need for future research.

This review is of basic models of the interactions between a pathogenic virus and vertebrate animal host. The interactions at the population level are described by a predatory-prey model, a common approach in the ecological sciences, and depend on births and deaths within each population. This ecological perspective is complemented by models at the genetical level, which includes the dynamics of gene frequencies and the mechanisms of evolution. These perspectives are symmetrical in their relatedness and reflect the idealized forms of processes in natural systems. In the latter sections, the general use of deep learning methods is discussed within the above context, and proposed for effective modeling of the response of a pathogenic virus in a pathogen–host system, which can lead to predictions about mutation and recombination in the virus population.

Flow and sediment regimes shape alluvial river channels; yet the influence of these abiotic drivers can be strongly mediated by biotic factors such as the size and density of riparian vegetation. We present results from an experiment designed to identify when plants control fluvial processes and to investigate the sensitivity of fluvial processes to changes in plant characteristics versus changes in flow rate or sediment supply. Live seedlings of two species with distinct morphologies, tamarisk (Tamarix spp.) and cottonwood (Populus fremontii), were placed in different configurations in a mobile sand‐bed flume. We measured the hydraulic and sediment flux responses of the channel at different flow rates and sediment supply conditions representing equilibrium (sediment supply = transport rate) and deficit (sediment supply < transport rate). We found that the hydraulic and sediment flux responses during sediment equilibrium represented a balance between abiotic and biotic factors and was sensitive to increasing flow rates and plant species and configuration. Species‐specific traits controlled the hydraulic response: compared to cottonwood, which has a more tree‐like morphology, the shrubby morphology of tamarisk resulted in less pronation and greater reductions in near‐bed velocities, Reynolds stress, and sediment flux rates. Under sediment‐deficit conditions, on the other hand, abiotic factors dampened the effect of variations in plant characteristics on the hydraulic response. We identified scenarios for which the highest stem‐density patch, independent of abiotic factors, dominated the fluvial response. These results provide insight into how and when plants influence fluvial processes in natural systems.

The production of microbially derived CO2 was investigated in the 3.6 m thick unsaturated geologic media of a mesoscale model system. The mesoscale model, which was 2.4 m diameter × 4.6 m high, was filled with a medium grained lacustrine sand, capped with an Ap (0.11 m) and B (0.20 m) soil profile, and maintained under steady state moisture conditions for 343 days. A near steady state soil gas CO2 concentration profile (>100 times greater than atmospheric) developed after 130 days implying that geochemical stability was rapidly attained. The presence of metabolically active microorganisms, consumption of O2 and dissolved organic carbon, and carbon 13 data indicated that the CO2 was microbially produced. At steady state, the calculated and modeled CO2 flux to the atmosphere (about 0.9 mol m−2 day−1) were greater than the measured CO2 flux (0.1 mol m−2 day−1) and greater than the calculated CO2 flux to the water table (0.02 mol m−2 day−1). The difference between the calculated and measured fluxes of CO2 to the atmosphere was attributed to spatial variability in the gas diffusion coefficient and reflected the difficulty in estimating CO2 production, even under steady state conditions. Laboratory estimates of microbial CO2 fluxes (1.8 and 2.9×103 mol m−2 day−1 ) were much greater than those determined from measured and calculated fluxes. Measured microbial respiration rates suggested that between 50 and 70% of the respired CO2 was produced in the unsaturated geologic medium beneath the Ap and B, and that there was sufficient CO2 production potential by bacteria to account for the respired CO2 determined from the flux calculations. These observations indicated that long‐term experimentation in mesoscale models can overcome some of the difficulties encountered in field studies and provide insight into biogeochemical processes in natural systems.

Microscopic reversibility of Sm and Yb sorption onto smectite and kaolinite: Experimental evidence