Journal articles: 'Adaptative optics'

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QU Yu-fu, 屈玉福, 刘子悦 LIU Zi-yue, 江云秋 JIANG Yun-qiu, 周. 丹. ZHOU Dan, and 王一帆 WANG Yi-fan. "Self-adaptative variable-metric feature point extraction method." Optics and Precision Engineering 25, no. 1 (2017): 188–97. http://dx.doi.org/10.3788/ope.20172501.0188.

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Palacios-Navarro, Guillermo, Fernando Arranz Martínez, Raúl Martín Ferrer, and Pedro Ramos Lorente. "Compensation Techniques Aimed at Mitigating Vibrations in Optical Ground-Based Telescopes: A Systematic Review." Sensors 21, no. 11 (May 22, 2021): 3613. http://dx.doi.org/10.3390/s21113613.

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The objective of this study was to evaluate the performance of the different systems and techniques aimed at suppressing vibrations on optical ground-based telescopes. We identified the studies by searching three electronic databases (Science Direct, IEEE library and Web of Science) from the year 2000 to December 2020. The studies were eligible if they proposed systems focused on mitigating the effects of vibrations in optical telescopes and brought performance data. A total of nine studies met our eligibility criteria. Current evidence confirms the feasibility of adaptative optics (AO) systems based on closed-loop control to mitigate vibrations, although variations and additions should be made depending on their nature and characteristics in order to improve the performance of the proposed techniques. This systematic review was conducted to provide a state-of-the-art of the methods and techniques that have been developed over the past two decades. The review also points out some issues that demand future research.

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Faurobert, M., M. Carbillet, L. Marquis, A. Chiavassa, and G. Ricort. "Temperature gradient in the solar photosphere. Test of a new spectroscopic method and study of its feasibility for ground-based telescopes." Astronomy & Astrophysics 616 (August 2018): A133. http://dx.doi.org/10.1051/0004-6361/201833195.

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Context. The contribution of quiet-Sun regions to the solar irradiance variability is currently unclear. Some solar-cycle variations of the quiet-Sun physical structure, such as the temperature gradient, might affect the irradiance. The synoptic measurement of this quantity along the activity cycle would improve our understanding of long-term irradiance variations. Aims. We intend to test a method previously introduced for measuring the photospheric temperature gradient from high-resolution spectroscopic observation and to study its feasibility with ground-based instruments with and without adaptative optics. Methods. We used synthetic profiles of the FeI 630.15 nm obtained from realistic three-dimensional hydrodynamical simulations of the photospheric granulation and line radiative transfer computations under local thermodynamical equilibrium conditions. Synthetic granulation images at different levels in the line are obtained by convolution with the instrumental point spread function (PSF) under various conditions of atmospheric turbulence, with and without correction by an adaptative optics (AO) system. The PSF are obtained with the PAOLA software, and the AO performances are inspired by the system that will be operating on the Daniel K. Inouye Solar Telescope. Results. We consider two different conditions of atmospheric turbulence, with Fried parameters of 7 cm and 5 cm, respectively. We show that the degraded images lead to both a bias and a loss of precision in the temperature-gradient measurement, and that the correction with the AO system allows us to drastically improve the measurement quality. Conclusions. Long-term synoptic observations of the temperature gradient in the solar photosphere can be undertaken by implementing this method on ground-based solar telescopes that are equipped with an AO correction system.

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Casner, Alexis, and Jean-Pierre Delville. "Adaptative lensing driven by the radiation pressure of a continuous-wave laser wave upon a near-critical liquid–liquid interface." Optics Letters 26, no. 18 (September 15, 2001): 1418. http://dx.doi.org/10.1364/ol.26.001418.

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Ng, Cherlyn J., Randolph Blake, Martin S. Banks, Duje Tadin, and Geunyoung Yoon. "Optics and neural adaptation jointly limit human stereovision." Proceedings of the National Academy of Sciences 118, no. 23 (June 1, 2021): e2100126118. http://dx.doi.org/10.1073/pnas.2100126118.

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Stereovision is the ability to perceive fine depth variations from small differences in the two eyes’ images. Using adaptive optics, we show that even minute optical aberrations that are not clinically correctable, and go unnoticed in everyday vision, can affect stereo acuity. Hence, the human binocular system is capable of using fine details that are not experienced in everyday vision. Interestingly, stereo acuity varied considerably across individuals even when they were provided identical perfect optics. We also found that individuals’ stereo acuity is better when viewing with their habitual optics rather than someone else’s (better) optics. Together, these findings suggest that the visual system compensates for habitual optical aberrations through neural adaptation and thereby optimizes stereovision uniquely for each individual. Thus, stereovision is limited by small optical aberrations and by neural adaptation to one’s own optics.

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Figorilli, Simone, Federico Pallottino, Giacomo Colle, Daniele Spada, Claudio Beni, Francesco Tocci, Simone Vasta, et al. "An Open Source Low-Cost Device Coupled with an Adaptative Time-Lag Time-Series Linear Forecasting Modeling for Apple Trentino (Italy) Precision Irrigation." Sensors 21, no. 8 (April 9, 2021): 2656. http://dx.doi.org/10.3390/s21082656.

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Precision irrigation represents those strategies aiming to feed the plant needs following the soil’s spatial and temporal characteristics. Such a differential irrigation requires a different approach and equipment with regard to conventional irrigation to reduce the environmental impact and the resources use while maximizing the production and thus profitability. This study described the development of an open source soil moisture LoRa (long-range) device and analysis of the data collected and updated directly in the field (i.e., weather station and ground sensor). The work produced adaptive supervised predictive models to optimize the management of agricultural precision irrigation practices and for an effective calibration of other agronomic interventions. These approaches are defined as adaptive because they self-learn with the acquisition of new data, updating the on-the-go model over time. The location chosen for the experimental setup is a cultivated area in the municipality of Tenna (Trentino, Alto Adige region, Italy), and the experiment was conducted on two different apple varieties during summer 2019. The adaptative partial least squares time-lag time-series modeling, in operative field conditions, was a posteriori applied in the consortium for 78 days during the dry season, producing total savings of 255 mm of irrigated water and 44,000 kW of electricity, equal to 10.82%.

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Oliveira, Ana, Duarte Dias, Elodie Múrias Lopes, Maria do Carmo Vilas-Boas, and João Paulo Silva Cunha. "SnapKi—An Inertial Easy-to-Adapt Wearable Textile Device for Movement Quantification of Neurological Patients." Sensors 20, no. 14 (July 11, 2020): 3875. http://dx.doi.org/10.3390/s20143875.

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The development of wearable health systems has been the focus of many researchers who aim to find solutions in healthcare. Additionally, the large potential of textiles to integrate electronics, together with the comfort and usability they provide, has contributed to the development of smart garments in this area. In the field of neurological disorders with motor impairment, clinicians look for wearable devices that may provide quantification of movement symptoms. Neurological disorders affect different motion abilities thus requiring different needs in movement quantification. With this background we designed and developed an inertial textile-embedded wearable device that is adaptable to different movement-disorders quantification requirements. This adaptative device is composed of a low-power 9-axis inertial unit, a customised textile band and a web and Android cross application used for data collection, debug and calibration. The textile band comprises a snap buttons system that allows the attachment of the inertial unit, as well as its connection with the analog sensors through conductive textile. The resulting system is easily adaptable for quantification of multiple motor symptoms in different parts of the body, such as rigidity, tremor and bradykinesia assessments, gait analysis, among others. In our project, the system was applied for a specific use-case of wrist rigidity quantification during Deep Brain Stimulation surgeries, showing its high versatility and receiving very positive feedback from patients and doctors.

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Rivera-Araya, Javier, Michael Schlömann, and Gloria J. Levicán. "Comparative Study of NaCl-Tolerance Mechanisms in Acidophilic Iron-Oxidizing Bacteria and Archaea." Solid State Phenomena 262 (August 2017): 385–88. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.385.

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Chloride leaching is considered a promising alternative method to recover copper from chalcopyrite and other primary copper sulfides, because it favors the leaching kinetics and avoids passivation of minerals. Nevertheless, chloride ions are highly toxic for iron-oxidizing microorganisms that participate in the bioleaching process. A comparative genomic analysis was carried out based on the complete genomes of bacteria belonging to Nitrospirae, Firmicutes, Actinobacteria and Proteobacteria phyla, and of archaea belonging to Euryarchaeota and Crenarchaeota was carried out to identify molecular determinants involved in chloride tolerance of acidophilic iron-oxidizing microorganisms. The results obtained showed that representative Nitrospirae and Firmicutes harbor genes for the biosynthesis and uptake of compatible solutes such as ectoine, trehalose and potassium, which have been shown to have a role in salt tolerance. Microorganisms belonging to other phyla harbor genes for potassium transporters, but no genes for compatible solutes were detected. In agreement with the bioinformatic results, minimum inhibitory concentration (MIC) determinations and growth kinetics experiments showed that Leptospirillum ferriphilum (Nitrospirae) was more tolerant to NaCl than Acidithiobacillus ferrooxidans (Proteobacteria). Furthermore, it was observed that the addition of 0.5 mM ectoine to the L. ferriphilum culture stimulated growth in the presence of 100 mM NaCl. On the contrary, ectoine had no effect on the growth of At. ferrooxidans. These results suggest that ectoine and likely trehalose could play a key role in chloride tolerance in L. ferriphilum. conferring adaptative advantages compared to A. ferrooxidans and possibly other iron-oxidizing microorganisms.

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Fernández, Enrique Josua. "Adaptive Optics for Visual Simulation." ISRN Optics 2012 (December 24, 2012): 1–13. http://dx.doi.org/10.5402/2012/104870.

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A revision of the current state-of-the-art adaptive optics technology for visual sciences is provided. The human eye, as an optical system able to generate images onto the retina, exhibits optical aberrations. Those are continuously changing with time, and they are different for every subject. Adaptive optics is the technology permitting the manipulation of the aberrations, and eventually their correction. Across the different applications of adaptive optics, the current paper focuses on visual simulation. These systems are capable of manipulating the ocular aberrations and simultaneous visual testing though the modified aberrations on real eyes. Some applications of the visual simulators presented in this work are the study of the neural adaptation to the aberrations, the influence of aberrations on accommodation, and the recent development of binocular adaptive optics visual simulators allowing the study of stereopsis.

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Ivanova, Natalia. "Biomimetic optics: liquid-based optical elements imitating the eye functionality." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, no. 2167 (February 3, 2020): 20190442. http://dx.doi.org/10.1098/rsta.2019.0442.

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The optical systems mimicking the eye functions are of great importance in various applications including consumer electronics, medical equipment, machine vision systems and robotics. This optics offers advantages over traditional optical technologies such as the superior adaptation to changing conditions and the comprehensive range of functional characteristics at miniature sizes. This paper presents a review on the recent progress in the development of human eye-inspired optical systems. Liquid-based and elastomer-based tunable optical elements are discussed with the focus on the actuation mechanism, optical performance and the possibility of integration into artificial eye systems. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology (part 3)’.

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Toprek, Dragan. "Proposed transport beam line for DESIR." Nuclear Technology and Radiation Protection 29, no. 3 (2014): 171–78. http://dx.doi.org/10.2298/ntrp1403171t.

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In this paper the detailed structure of the transport beam line design is proposed, quadrupoles and deflectors specifications in order to transport the beam from the optic adaptation point in the SPIRAL2 production building up to the adaptation point in the DESIR hall. All optical elements, in beam line, are electrostatic and so, settings are independent of the ratio q/m of the particle. The calculations are done by COSY INFINITY computer code in first order of approximation and without fringe field effects. The beam emittances at the starting point (adaptation point in the SPIRAL2 production building) in horizontal and vertical planes are 80p mm mrad. The beam line is designed in such a way that the beam sizes, in both planes, at the end (adaptation point in the DESIR hall) are kept the same as they are at the starting point; the horizontal and vertical displacements from the optic axis at starting and ending points are the same, ?6 mm. In such case the efficiency of transport of the beam is high.

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Novales Flamarique, Iñigo, and Matt Wachowiak. "Functional segregation of retinal ganglion cell projections to the optic tectum of rainbow trout." Journal of Neurophysiology 114, no. 5 (November 2015): 2703–17. http://dx.doi.org/10.1152/jn.00440.2015.

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The interpretation of visual information relies on precise maps of retinal representation in the brain coupled with local circuitry that encodes specific features of the visual scenery. In nonmammalian vertebrates, the main target of ganglion cell projections is the optic tectum. Although the topography of retinotectal projections has been documented for several species, the spatiotemporal patterns of activity and how these depend on background adaptation have not been explored. In this study, we used a combination of electrical and optical recordings to reveal a retinotectal map of ganglion cell projections to the optic tectum of rainbow trout and characterized the spatial and chromatic distribution of ganglion cell fibers coding for increments (ON) and decrements (OFF) of light. Recordings of optic nerve activity under various adapting light backgrounds, which isolated the input of different cone mechanisms, yielded dynamic patterns of ON and OFF input characterized by segregation of these two fiber types. Chromatic adaptation decreased the sensitivity and response latency of affected cone mechanisms, revealing their variable contributions to the ON and OFF responses. Our experiments further demonstrated restricted input from a UV cone mechanism to the anterolateral optic tectum, in accordance with the limited presence of UV cones in the dorsotemporal retina of juvenile rainbow trout. Together, our findings show that retinal inputs to the optic tectum of this species are not homogeneous, exhibit highly dynamic activity patterns, and are likely determined by a combination of biased projections and specific retinal cell distributions and their activity states.

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Liang, Pei, Roland Kern, Rafael Kurtz, and Martin Egelhaaf. "Impact of visual motion adaptation on neural responses to objects and its dependence on the temporal characteristics of optic flow." Journal of Neurophysiology 105, no. 4 (April 2011): 1825–34. http://dx.doi.org/10.1152/jn.00359.2010.

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It is still unclear how sensory systems efficiently encode signals with statistics as experienced by animals in the real world and what role adaptation plays during normal behavior. Therefore, we studied the performance of visual motion-sensitive neurons of blowflies, the horizontal system neurons, with optic flow that was reconstructed from the head trajectories of semi-free-flying flies. To test how motion adaptation is affected by optic flow dynamics, we manipulated the seminatural optic flow by targeted modifications of the flight trajectories and assessed to what extent neuronal responses to an object located close to the flight trajectory depend on adaptation dynamics. For all types of adapting optic flow object-induced response increments were stronger in the adapted compared with the nonadapted state. Adaptation with optic flow characterized by the typical alternation between translational and rotational segments produced this effect but also adaptation with optic flow that lacked these distinguishing features and even pure rotation at a constant angular velocity. The enhancement of object-induced response increments had a direction-selective component because preferred-direction rotation and natural optic flow were more efficient adaptors than null-direction rotation. These results indicate that natural dynamics of optic flow is not a basic requirement to adapt neurons in a specific, presumably functionally beneficial way. Our findings are discussed in the light of adaptation mechanisms proposed on the basis of experiments previously done with conventional experimenter-defined stimuli.

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Bîcleşanu, Cornelia, Anamaria Florescu, Alexandru Burcea, Stefan Manea, and Tiberiu Botea. "Optical microscopy study on the marginal adaptation of tunnel restaurations with resins composite." Romanian Journal of Stomatology 65, no. 2 (June 30, 2019): 182–93. http://dx.doi.org/10.37897/rjs.2019.2.11.

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Zielińska, Agnieszka, Karolina Kiluk, Maciej Wojtkowski, and Katarzyna Komar. "System for psychophysical measurements of two-photon vision." Photonics Letters of Poland 11, no. 1 (April 3, 2019): 1. http://dx.doi.org/10.4302/plp.v11i1.837.

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Two-photon absorption occurring in photoreceptors of human eye is responsible for perception of pulsed infrared laser beams. Color of perceived light corresponds to about half of wavelength of stimulating beam. This recently discovered phenomenon is called two-photon vision. However it is yet not clear how such phenomena could impact an ophthalmic diagnosis and therefore further studies are required. In this paper we present the system that enables future psychophysical experiments to extend knowledge about two-photon vision and its diagnostic value by identifying differences between two-photon and single-photon vision. Full Text: PDF ReferencesD. A. Atchison, G. Smith, Optics of the human eye (Butterworth-Heinemann 2000) CrossRef G. Palczewska et al. "Human infrared vision is triggered by two-photon chromophore isomerization", Proceedings of the National Academy of Sciences 111, 1428 (2014). CrossRef P. Artal, S. Manzanera, K. Komar, A. Gambín-Regadera, M. Wojtkowski, "Visual acuity in two-photon infrared vision", Optica 4, 1488 (2017). CrossRef K. Komar et al. "Posterior Eye Shape Measurement With Retinal OCT Compared to MRI", Investigative Ophthalmology & Visual Science 57, 196 (2016). CrossRef K. Komar et al. "Two-photon visual sensitivity of human cones - a psychophysical study", Investigative Ophthalmology & Visual Science 59, 4049 (2018). DirectLink S. A. Burns,R.H. Webb, Handbook of optics 28 (New York, McGraw Hill 1994) DirectLink R. W. Nygaard, T. E. Frumkes, "Calibration of the retinal illuminance provided by maxwellian views", Vision Research (1982) CrossRef P. Melillo et al. "Pupillometric analysis for assessment of gene therapy in Leber Congenital Amaurosis patients", Biomedical engineering online 11, 40 (2012) CrossRef P. A. Stanley, A. K. Davies, "The effect of field of view size on steady-state pupil diameter", Ophthalmic and Physiological Optics, 15, 601 (1995) CrossRef S. Mathôt, "Pupil mimicry is the result of brightness perception of the iris and pupil" Journal of Cognition 1 (2018) CrossRef M. M. Thomas, T. D. Lamb, "Light adaptation and dark adaptation of human rod photoreceptors measured from the a‐wave of the electroretinogram", The Journal of physiology 518, 479 (1999) CrossRef

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Nikitchenko, V., S. Gordeev, S. Kaletnik, and O. Butenko. "SYSTEM OF PERSON’S VISUAL PERCEPTION AS AN OBJECT OF IMPACT BY LIGHT EMISSION." Наукові праці Державного науково-дослідного інституту випробувань і сертифікації озброєння та військової техніки, no. 8 (June 29, 2021): 91–100. http://dx.doi.org/10.37701/dndivsovt.8.2021.10.

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In modern conditions of hostilities, informativity plays an important role in both defense and offensive operations. Most of the information, including technical, passes through optical systems. Optoelectronic and infrared devices, missile homing heads, the human eye in their structure have optics with different coefficients. A light pulse of different levels makes a negative impact on optical systems decreasing data throughput. One of the possible types of impact on personnel in order to disorient enemy troops and disable optical surveillance and sighting systems is the use of light emission. Light emission can negatively affect the system of visual perception and cause the deterioration of information processing efficiency, so it can be used as a factor for the destruction of enemy personnel. In the process of impact by light emission on the system of visual perception, the phenomenon of after-effect is possible. It consists in the process of adaptation of the system of visual perception to the perception of information after exposure to bright light emission. The visual center of the brain plays a major role in the adaptation processes, so a human can see the transitions of the brightness of the adaptive background. The longest adaptation time occurs when exposed to blue and white light. The increase in the area of receptive fields leads to a decrease in the resolving capabilities of the system of visual perception and affects the effectiveness of the combat task in terms of target recognition and sighting. The main intense light emission impact factors on the enemy’s personnel are: psychological effect (disorientation and distraction) which is manifested in the temporary cessation of task execution, which relates to the unexpected emergence of bright emission; impairment of visual function (when intense bright light emission blocks the system of visual perception; temporary loss of vision; disorientation and epileptic attacks.

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Jaramillo Flórez, Samuel Ángel, and Yuli Fernanda Achipiz. "APPLICATIONS OF THE LIGHT LASER WITH SPATIAL INCOHERENCE AND BIONIC OPTIMIZATION TO THE OPTICAL WIRELESS COMMUNICATIONS." Revista de Investigaciones Universidad del Quindío 25, no. 1 (March 28, 2014): 169–85. http://dx.doi.org/10.33975/riuq.vol25n1.169.

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The bioelectronics takes of the biology the optimized elements for to do a copy and to build technological mechanisms with functions based in that of body lives components. Telecommunications and biology present an analogy between the optical receivers and insects eyes, which forms are adequate to receipt signal since a transmitter, and these are been leaded to perfection by the nature during millions of years in the environment adaptation. The sizes and the forms depend of the direction of the waves and of the radiation pattern of these biotransmitters and bioreceivers (omatidies of insects eyes), which is similar as the optical communications emitters and photodetectors. The growth of the telecommunication services makes necessary the optimization of the bandwidth of the transmission channels. Although the optic transmission is considered like the ideal as for the attenuation and distortion characteristics that make that it possesses the better relation bandwidth - longitude, the demand of more transmission capacity forces to take advantage of them efficiently. High costs generated when deploying Optic Fiber Networks at the transport level, together with other factors that avoid PONs arriving to the home and/or office, have impulsed the design and implementation of partially optical networks (FITL), including an alternative that uses infrared light. This work explores the basis of these news access networks, and it is presented an optical communication transmission/reception system with optic channel of free space where has been modulated the transmitter laser through a set of spherical lens and optical fibers that expand the beam of light to different points of an indoor enclosure producing multiple punctual images located in positions that permit to determine and to optimize the bandwidth of the system. The computational simulation results are showed and are compared with those experimentally measured, indicating that this is an original method for to design emitters and receivers of high performance for optical communications.

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Boulton, J. "Spatial frequency adaptation in optic neuritis." Ophthalmic and Physiological Optics 12, no. 1 (January 1992): 84. http://dx.doi.org/10.1016/0275-5408(92)90026-s.

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Sieber, Ingo, Richard Thelen, and Ulrich Gengenbach. "Enhancement of High-Resolution 3D Inkjet-Printing of Optical Freeform Surfaces Using Digital Twins." Micromachines 12, no. 1 (December 30, 2020): 35. http://dx.doi.org/10.3390/mi12010035.

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3D-inkjet-printing is just beginning to take off in the optical field. Advantages of this technique include its fast and cost-efficient fabrication without tooling costs. However, there are still obstacles preventing 3D inkjet-printing from a broad usage in optics, e.g., insufficient form fidelity. In this article, we present the formulation of a digital twin by the enhancement of an optical model by integrating geometrical measurement data. This approach strengthens the high-precision 3D printing process to fulfil optical precision requirements. A process flow between the design of freeform components, fabrication by inkjet printing, the geometrical measurement of the fabricated optical surface, and the feedback of the measurement data into the simulation model was developed, and its interfaces were defined. The evaluation of the measurements allowed for the adaptation of the printing process to compensate for process errors and tolerances. Furthermore, the performance of the manufactured component was simulated and compared with the nominal performance, and the enhanced model could be used for sensitivity analysis. The method was applied to a highly complex helical surface that allowed for the adjustment of the optical power by rotation. We show that sensitivity analysis could be used to define acceptable tolerance budgets of the process.

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Gao, Cheng, Zhifeng Wang, Yang Xu, Manuel Melgosa, Kaida Xiao, Michael H. Brill, and Changjun Li. "The von Kries chromatic adaptation transform and its generalization." Chinese Optics Letters 18, no. 3 (2020): 033301. http://dx.doi.org/10.3788/col202018.033301.

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Lukauskiene, R., J. Jankauskiene, and B. Mickiene. "Dark Adaptation in Patients with Thyroid Optic Neuropathy." Perception 26, no. 1_suppl (August 1997): 246. http://dx.doi.org/10.1068/v970233.

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In patients with thyroid optic neuropathy, vision may deteriorate because of compression of the optic nerve by swollen extraocular muscles. We examined dark adaptation in nineteen patients, aged 25 – 59 years, with thyroid optic neuropathy with an ARP adaptometer. The duration of the disease was less than 1 month in five patients, 1 – 3 months in eight patients, and more than 3 months in six patients. The age-matched control group consisted of twelve healthy people with normal visual acuity. We found that visual acuity was reduced in fourteen of the patients. In patients with duration of the illness of 1 – 3 months and over 3 months, dark adaptation was impaired. In patients with less than 1 month duration of the disease, all measurements were within normal limits. The results show that characteristics of dark-adaptation change progressively during thyroid optic neuropathy, thus providing objective and additional information for diagnosis and prognosis. These data are useful in choosing the tactics of treatment.

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ZHAO Chunhui, 赵春晖, 李彤 LI Tong, and 冯收 FENG Shou. "基于密集卷积和域自适应的高光谱图像分类." ACTA PHOTONICA SINICA 50, no. 3 (2021): 148. http://dx.doi.org/10.3788/gzxb20215003.0310001.

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Bruggeman, Hugo, Wendy Zosh, and William H. Warren. "Optic Flow Drives Human Visuo-Locomotor Adaptation." Current Biology 17, no. 23 (December 2007): 2035–40. http://dx.doi.org/10.1016/j.cub.2007.10.059.

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Maser, J., C. Jacobsen, Y. Wang, A. Osanna, B. Winn, and J. Kirz. "Imaging, Spectroscopy and Tomography of Frozen Hydrated Specimens With the Cryo Scanning Transmission X-Ray Microscope at The NSLS." Microscopy and Microanalysis 4, S2 (July 1998): 354–55. http://dx.doi.org/10.1017/s1431927600021899.

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With the steady improvement of x-ray optics with high resolution and efficiency, and continued development or adaptation of different imaging and measuring techniques, soft x-ray microscopy has emerged as a powerful method to image and analyze fully hydrated specimens of several micrometer thickness at sub-optical resolution (for a recent overview, see ref. 1). We report on experiments performed with the cryo scanning transmission x-ray microscope (cryo-STXM), which has recently come into operation at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory.Cryo-STXM uses x-rays with energies between the absorption edge of Carbon (E = 284 eV) and Oxygen (E = 543 eV) from the soft x-ray undulator at the NSLS. Fully hydrated specimens such as eucaryotic cells in water or ice layers of up to 10 micrometer thickness can be imaged without any additional need for contrast enhancing techniques.

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Marshall-Goebel, Karina, Rahul Damani, and Eric M. Bershad. "Brain Physiological Response and Adaptation During Spaceflight." Neurosurgery 85, no. 5 (June 19, 2019): E815—E821. http://dx.doi.org/10.1093/neuros/nyz203.

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Abstract More than half of astronauts returning from long-duration missions on the International Space Station present with neuro-ocular structural and/or functional changes, including optic disc edema, optic nerve sheath distension, globe flattening, choroidal folds, or hyperopic shifts. This spaceflight-associated neuro-ocular syndrome (SANS) represents a major risk to future exploration class human spaceflight missions, including Mars missions. Although the exact pathophysiology of SANS is unknown, evidence thus far suggests that an increase in intracranial pressure (ICP) relative to the upright position on Earth, which is due to the loss of hydrostatic pressure gradients in space, may play a leading role. This review focuses on brain physiology in the spaceflight environment, specifically on how spaceflight may affect ICP and related indicators of cranial compliance, potential factors related to the development of SANS, and findings from spaceflight as well as ground-based spaceflight analog research studies.

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Finley, James M., Matthew A. Statton, and Amy J. Bastian. "A novel optic flow pattern speeds split-belt locomotor adaptation." Journal of Neurophysiology 111, no. 5 (March 1, 2014): 969–76. http://dx.doi.org/10.1152/jn.00513.2013.

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Visual input provides vital information for helping us modify our walking pattern. For example, artificial optic flow can drive changes in step length during locomotion and may also be useful for augmenting locomotor training for individuals with gait asymmetries. Here we asked whether optic flow could modify the acquisition of a symmetric walking pattern during split-belt treadmill adaptation. Participants walked on a split-belt treadmill while watching a virtual scene that produced artificial optic flow. For the Stance Congruent group, the scene moved at the slow belt speed at foot strike on the slow belt and then moved at the fast belt speed at foot strike on the fast belt. This approximates what participants would see if they moved over ground with the same walking pattern. For the Stance Incongruent group, the scene moved fast during slow stance and vice versa. In this case, flow speed does not match what the foot is experiencing, but predicts the belt speed for the next foot strike. Results showed that the Stance Incongruent group learned more quickly than the Stance Congruent group even though each group learned the same amount during adaptation. The increase in learning rate was primarily driven by changes in spatial control of each limb, rather than temporal control. Interestingly, when this alternating optic flow pattern was presented alone, no adaptation occurred. Our results demonstrate that an unnatural pattern of optic flow, one that predicts the belt speed on the next foot strike, can be used to enhance learning rate during split-belt locomotor adaptation.

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Cerviño, Alejandro. "Neural Adaptation to Optical Quality Defects." Journal of Optometry 3, no. 1 (2010): 1. http://dx.doi.org/10.3921/joptom.2010.1.

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Glover, Scott, and Peter Dixon. "Motor adaptation to an optical illusion." Experimental Brain Research 137, no. 2 (March 19, 2001): 254–58. http://dx.doi.org/10.1007/s002210000651.

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Boudaoud, A., Y. Couder, and M. Ben Amar. "A self-adaptative oscillator." European Physical Journal B 9, no. 1 (May 1999): 159–65. http://dx.doi.org/10.1007/s100510050751.

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Yamamoto, Etsuko, Naoichi Horio, Hiroko Terasaki, and Yozo Miyake. "Evaluation of optic nerve function by flicker adaptation in optic nerve diseases." Neuro-Ophthalmology 26, no. 1 (January 2001): 35–41. http://dx.doi.org/10.1076/noph.26.1.35.8052.

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HAN Xu, 韩旭, 马军 MA Jun, 黎明 LI Ming, 付跃刚 FU Yue-gang, and 王加科 WANG Jia-ke. "Temperature adaptation of mapping camera." Optics and Precision Engineering 20, no. 6 (2012): 1175–81. http://dx.doi.org/10.3788/ope.20122006.1175.

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Davis, Robert G., and Lewis O. Harvey. "Simulating Adaptation Luminances." LEUKOS 4, no. 1 (July 1, 2007): 31–55. http://dx.doi.org/10.1582/leukos.2007.04.01.002.

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Rangel-Fonseca, Piero, Armando Gomez-Vieyra, Daniel Malacara-Hernandez, and Mario Cesar Wilson-Herran. "Automated detection of photoreceptors in in-vivo retinal images." DYNA 83, no. 199 (October 1, 2016): 57. http://dx.doi.org/10.15446/dyna.v83n199.54578.

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La inclusión de la óptica adaptativa (adaptive optics, AO) en la tecnología de imágenes oftálmicas ha permitido el estudio in-vivo de los elementos histológicos de retina, como los fotorreceptores, células del epitelio pigmentario de la retina (retinal pigment ephitelium, RPE), la capa de fibras nerviosas de la retina y células ganglionares. Las imágenes de alta resolución obtenidas con dispositivos oftálmicos con AO son ricos en información, que es difícil y/o tediosa de cuantificar por medio de métodos manuales. Por lo tanto, se requieren herramientas de análisis automatizadas robustas que puedan proporcionar información cuantitativa reproducible del tejido bajo examen. Algoritmos automatizados han sido desarrollados para detectar la posición de células individuales fotorreceptoras y caracterizar el mosaico RPE. En este trabajo, se presenta un algoritmo para la detección de los fotorreceptores. El algoritmo ha sido probado en imágenes sintéticas y reales adquiridas con un oftalmoscopio de barrido láser con óptica adaptativa (Adaptive Optics Scanning Laser Ophthalmoscope, AOSLO) y comparado con el desarrollado por Li y Roorda. Se muestra que ambos algoritmos tienen un rendimiento similar en imágenes sintéticas e imágenes con sólo conos, pero el algoritmo propuesto muestra mediciones más precisas cuando se utiliza para la detección de conos-bastones en imágenes reales.

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Heitwerth, J., R. Kern, J. H. van Hateren, and M. Egelhaaf. "Motion Adaptation Leads to Parsimonious Encoding of Natural Optic Flow by Blowfly Motion Vision System." Journal of Neurophysiology 94, no. 3 (September 2005): 1761–69. http://dx.doi.org/10.1152/jn.00308.2005.

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Neurons sensitive to visual motion change their response properties during prolonged motion stimulation. These changes have been interpreted as adaptive and were concluded, for instance, to adjust the sensitivity of the visual motion pathway to velocity changes or to increase the reliability of encoding of motion information. These conclusions are based on experiments with experimenter-designed motion stimuli that differ substantially with respect to their dynamical properties from the optic flow an animal experiences during normal behavior. We analyze for the first time motion adaptation under natural stimulus conditions. The experiments are done on the H1-cell, an identified neuron in the blowfly visual motion pathway that has served in many previous studies as a model system for visual motion computation. We reconstructed optic flow perceived by a blowfly in free flight and used this behaviorally generated optic flow to study motion adaptation. A variety of measures (variability in spike count, response latency, jitter of spike timing) suggests that the coding quality does not improve with prolonged stimulation. However, although the number of spikes decreases considerably during stimulation with natural optic flow, the amount of information that is conveyed stays nearly constant. Thus the information per spike increases, and motion adaptation leads to parsimonious coding without sacrificing the reliability with which behaviorally relevant information is encoded.

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Shemshedinov, R. B. "Adaptation in optical detection-and-ranging systems." Journal of Optical Technology 71, no. 2 (February 1, 2004): 97. http://dx.doi.org/10.1364/jot.71.000097.

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Ibbotson, Michael R., Colin W. G. Clifford, and Richard F. Mark. "Adaptation to Visual Motion in Directional Neurons of the Nucleus of the Optic Tract." Journal of Neurophysiology 79, no. 3 (March 1, 1998): 1481–93. http://dx.doi.org/10.1152/jn.1998.79.3.1481.

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Ibbotson, Michael R., Colin W. G. Clifford, and Richard F. Mark. Adaptation to visual motion in directional neurons of the nucleus of the optic tract. J. Neurophysiol. 79: 1481–1493, 1998. Extracellular recordings of action potentials were made from directional neurons in the nucleus of the optic tract (NOT) of the wallaby, Macropus eugenii, while stimulating with moving sine-wave gratings. When a grating was moved at a constant velocity in the preferred direction through a neuron's receptive field, the firing rate increased rapidly and then declined exponentially until reaching a steady-state level. The decline in response is called motion adaptation. The rate of adaptation increased as the temporal frequency of the drifting grating increased, up to the frequency that elicited the maximum firing rate. Beyond this frequency, the adaptation rate decreased. When the adapting grating's spatial frequency was varied, such that response magnitudes were significantly different, the maximum adaptation rate occurred at similar temporal frequencies. Hence the temporal frequency of the stimulus is a major parameter controlling the rate of adaptation. In most neurons, the temporal frequency response functions measured after adaptation were shifted to the right when compared with those obtained in the unadapted state. Further insight into the adaptation process was obtained by measuring the responses of the cells to grating displacements within one frame (10.23 ms). Such impulsive stimulus movements of less than a one-quarter cycle elicited a response that rose rapidly to a maximum and then declined exponentially to the spontaneous firing rate in several seconds. The level of adaptation was demonstrated by observing how the time constants of the exponentials varied as a function of the temporal frequency of a previously presented moving grating. When plotted as functions of adapting frequency, time constants formed a U-shaped curve. The shortest time constants occurred at similar temporal frequencies, regardless of changes in spatial frequency, even when the change in spatial frequency resulted in large differences in response magnitude during the adaptation period. The strongest adaptation occurred when the adapting stimulus moved in the neuron's preferred direction. Stimuli that moved in the antipreferred direction or flickered had an adapting influence on the responses to subsequent impulsive movements, but the effect was far smaller than that elicited by preferred direction adaptation. Adaptation in one region of the receptive field did not affect the responses elicited by subsequent stimulation in nonoverlapping regions of the field. Adaptation is a significant property of NOT neurons and probably acts to expand their temporal resolving power.

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Ibbotson, M. R. "Contrast and Temporal Frequency-Related Adaptation in the Pretectal Nucleus of the Optic Tract." Journal of Neurophysiology 94, no. 1 (July 2005): 136–46. http://dx.doi.org/10.1152/jn.00980.2004.

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In mammals, many cells in the retino-geniculate-cortical pathway adapt during stimulation with high contrast gratings. In the visual cortex, adaptation to high contrast images reduces sensitivity at low contrasts while only moderately affecting sensitivity at high contrasts, thus generating rightward shifts in the contrast response functions (contrast gain control). Similarly, motion adaptation at particular temporal frequencies (TFs) alters the temporal tuning properties of cortical cells. For the first time in any species, this paper investigates the influence of motion adaptation on both the contrast and TF responses of neurons in the retino-pretectal pathway by recording from direction-selective neurons in the nucleus of the optic tract (NOT) of the marsupial wallaby, Macropus eugenii. This species is of interest because its NOT receives almost all input directly from the retina, with virtually none from the visual cortex (unlike cats and primates). All NOT cells show changes in their contrast response functions after adaptation, many revealing contrast gain control. Contrast adaptation is direction-dependent, preferred directions producing the largest changes. The lack of cortical input suggests that contrast adaptation is generated independently from the cortex in the NOT or retina. Motion adaptation also produces direction-selective effects on the TF tuning of NOT neurons by shifting the location of the optimum TF. Cells that show strong adaptation to contrast also tend to show large changes in TF tuning, suggesting similar intracellular mechanisms. The data are discussed in terms of the generality of contrast adaptation across mammalian species and across unconnected brain regions within the same species.

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Xu, Ying, Bing Li, Bao-Wang Li, and Yun-Cheng Diao. "Adaptation of PMLS neurons to prolonged optic flow stimuli." Neuroreport 12, no. 18 (December 2001): 4055–59. http://dx.doi.org/10.1097/00001756-200112210-00039.

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Jonas, Jost B., Frank-Michael Z�ch, and Gottfried O. H. Naumann. "Dark adaptation in glaucomatous and nonglaucomatous optic nerve atrophy." Graefe's Archive for Clinical and Experimental Ophthalmology 228, no. 4 (1990): 321–25. http://dx.doi.org/10.1007/bf00920055.

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Valtcheva, Tchoudomira M., and Christopher L. Passaglia. "Contrast adaptation in the Limulus lateral eye." Journal of Neurophysiology 114, no. 6 (December 1, 2015): 3234–41. http://dx.doi.org/10.1152/jn.00593.2015.

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Luminance and contrast adaptation are neuronal mechanisms employed by the visual system to adjust our sensitivity to light. They are mediated by an assortment of cellular and network processes distributed across the retina and visual cortex. Both have been demonstrated in the eyes of many vertebrates, but only luminance adaptation has been shown in invertebrate eyes to date. Since the computational benefits of contrast adaptation should apply to all visual systems, we investigated whether this mechanism operates in horseshoe crab eyes, one of the best-understood neural networks in the animal kingdom. The spike trains of optic nerve fibers were recorded in response to light stimuli modulated randomly in time and delivered to single ommatidia or the whole eye. We found that the retina adapts to both the mean luminance and contrast of a white-noise stimulus, that luminance- and contrast-adaptive processes are largely independent, and that they originate within an ommatidium. Network interactions are not involved. A published computer model that simulates existing knowledge of the horseshoe crab eye did not show contrast adaptation, suggesting that a heretofore unknown mechanism may underlie the phenomenon. This mechanism does not appear to reside in photoreceptors because white-noise analysis of electroretinogram recordings did not show contrast adaptation. The likely site of origin is therefore the spike discharge mechanism of optic nerve fibers. The finding of contrast adaption in a retinal network as simple as the horseshoe crab eye underscores the broader importance of this image processing strategy to vision.

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Porubčinová, Martina, and Ivana Novotná. "Work 4.0 Competencies in the Female Optics." Research Papers Faculty of Materials Science and Technology Slovak University of Technology 28, no. 46 (June 1, 2020): 65–73. http://dx.doi.org/10.2478/rput-2020-0009.

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AbstractRecently, the research in Industry 4.0 has been focused not only on the technological aspects of Industry 4.0, but also on the wellbeing of the workers and their autonomy and job satisfaction. In this paper, specific requirements related to Industry 4.0 implementation are reflected with regard to female element. Based on the analysis of the key challenges of the Industry 4.0 development, specific challenges in human capital of women are pointed out, such as e.g. the social skills, maintenance of non-routine jobs, and support to adaptation to Industry 4.0. The aim of the paper is to analyse if women in Slovakia are prepared for the of Industry 4.0 development in terms of digital access, digital literacy and digital attitudes (patterns of digital participation).

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Kalloniatis, Michael, and Ronald S. Harwerth. "Spectral sensitivity and adaptation characteristics of cone mechanisms under white-light adaptation." Journal of the Optical Society of America A 7, no. 10 (October 1, 1990): 1912. http://dx.doi.org/10.1364/josaa.7.001912.

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Hillis, James M., and David H. Brainard. "Do common mechanisms of adaptation mediate color discrimination and appearance? Contrast adaptation." Journal of the Optical Society of America A 24, no. 8 (July 11, 2007): 2122. http://dx.doi.org/10.1364/josaa.24.002122.

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Taniguchi, M., M. Kashiwayanagi, and K. Kurihara. "Quantitative analysis on odor intensity and quality of optical isomers in turtle olfactory system." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 262, no. 1 (January 1, 1992): R99—R104. http://dx.doi.org/10.1152/ajpregu.1992.262.1.r99.

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No systematic electrophysiological study on differences in odor intensity and quality between optical isomers has been carried out. In the present study, we measured the turtle olfactory bulbar responses to six pairs of highly pure optical isomers and compared the differences in odor intensity and quality between the optical isomers. The results obtained indicated that with all odorants tested, there was no difference in odor threshold and intensity in the whole concentration range examined between optical isomers. The difference in odor quality of optical isomers was evaluated by a quantitative cross-adaptation method in which odorant concentration was varied. The degree of cross adaptation between optical isomers greatly varied with species of odorants. The rank order of the magnitude of the differences in odor quality between optical isomers was carvone greater than beta-citronellol greater than menthol greater than hydroxycitronellal greater than citronellal greater than limonene.

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LIU Ju, 刘巨, 董得义 DONG De-yi, 辛宏伟 XIN Hong-wei, 李志来 LI Zhi-lai, 张学军 ZHANG Xue-jun, and 崔抗 CUI Kang. "Temperature adaptation of large aperture mirror assembly." Optics and Precision Engineering 21, no. 12 (2013): 3169–75. http://dx.doi.org/10.3788/ope.20132112.3169.

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Michel, Carine, and Remy Cruz. "Prism adaptation power on spatial cognition: Adaptation to different optical deviations in healthy individuals." Neuroscience Letters 590 (March 2015): 145–49. http://dx.doi.org/10.1016/j.neulet.2015.02.001.

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MADDESS, T., R. A. DUBOIS, and M. R. IBBOTSON. "Response Properties and Adaptation of Neurones Sensitive to Image Motion in the Butterfly Papilio Aegeus." Journal of Experimental Biology 161, no. 1 (November 1, 1991): 171–99. http://dx.doi.org/10.1242/jeb.161.1.171.

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Wide-field direction-selective neurones from the optic lobes of the butterfly Papilio aegeus show some properties similar to those displayed by the large neurones of the fly lobula plate. Temporal and spatial frequency threshold tuning curves show that butterfly optic lobe neurones sensitive to different directions of image motion are fed by presynaptic subunits similar to those of the fly. However, unlike fly lobula plate neurones, the butterfly optic lobe neurones show a steep low-spatial-frequency roll-off which persists even at high temporal frequencies. Also exceptional is the temporal resolution of rapid changes in image speed by the butterfly neurones. When the cells are adapted to continuous motion their responses indicate a further increase in temporal resolution. Evidence is provided that in any one state of adaptation the neurones may be thought of as piece-wise linear and, thus, their responses can be predicted by convolution with a velocity kernel measured for that adaptation state. Adaptation to continuous motion results in the cells responding to motion in proportion to the mean motion signal. Motion in the non-preferred direction also appears to adapt the cells. Velocity impulse responses of both butterfly and blowfly neurones were determined with one-dimensional gratings and two-dimensional textured patterns and the results for the two stimuli are shown to be very similar.

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Lattard, E., S. Kurutcharry, M. Lejeune, M. Oudjedi, and P. Abelard. "0.9PMN-0.1PT ceramics as adaptative material." Ferroelectrics 227, no. 1 (April 1999): 51–75. http://dx.doi.org/10.1080/00150199908224190.

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Barbot, Antoine, John Pirog, Cherlyn Ng, and Geunyoung Yoon. "Neural adaptation to optical aberrations through phase compensation." Journal of Vision 20, no. 11 (October 20, 2020): 1130. http://dx.doi.org/10.1167/jov.20.11.1130.

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Sumitani, M., Y. Rossetti, M. Shibata, Y. Matsuda, G. Sakaue, T. Inoue, T. Mashimo, and S. Miyauchi. "Prism adaptation to optical deviation alleviates pathologic pain." Neurology 68, no. 2 (January 8, 2007): 128–33. http://dx.doi.org/10.1212/01.wnl.0000250242.99683.57.

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Journal articles on the topic 'Adaptative optics'

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