scholarly journals CompoundRay: An open-source tool for high-speed and high-fidelity rendering of compound eyes

2021 ◽  
Author(s):  
Blayze F Millward ◽  
Steve Maddock ◽  
Michael Mangan
Keyword(s):  
Open Source ◽  
Visual Information ◽  
High Speed ◽  
Compound Eye ◽  
Compound Eyes ◽  
High Fidelity ◽  
Desert Ant ◽  
New Generation ◽  
The Impact

Revealing the functioning of non-standard visual systems such as compound eyes is of interest to biologists and engineers alike. A key investigative method is to replicate the sensory apparatus using artificial systems, allowing for investigation of the visual information that drives animal behaviour when exposed to environmental cues. To date, 'Compound Eye Models' (CEMs) have largely explored the impact of features such as spectral sensitivity, field of view, and angular resolution on behaviour. Yet, the role of shape and overall structure have been largely overlooked due to modelling complexity. However, modern real-time raytracing technologies are enabling the construction of a new generation of computationally fast, high-fidelity CEMs. This work introduces new open-source CEM software (CompoundRay) alongside standardised usage techniques, while also discussing the difficulties inherent with visual data display and analysis of compound eye perceptual data. CompoundRay is capable of accurately rendering the visual perspective of a desert ant at over 5,000 frames per second in a 3D mapped natural environment. It supports ommatidial arrangements at arbitrary positions with per-ommatidial heterogeneity.

scholarly journals Interphotoreceptor coupling: an evolutionary perspective

2021 ◽  
Author(s):  
Lorenzo Cangiano ◽  
Sabrina Asteriti
Keyword(s):  
Visual Information ◽  
Signal To Noise Ratio ◽  
Electrical Coupling ◽  
Physiological Role ◽  
Cellular Processes ◽  
Contact Points ◽  
Highly Sensitive ◽  
The Many ◽  
The Impact

AbstractIn the vertebrate retina, signals generated by cones of different spectral preference and by highly sensitive rod photoreceptors interact at various levels to extract salient visual information. The first opportunity for such interaction is offered by electrical coupling of the photoreceptors themselves, which is mediated by gap junctions located at the contact points of specialised cellular processes: synaptic terminals, telodendria and radial fins. Here, we examine the evolutionary pressures for and against interphotoreceptor coupling, which are likely to have shaped how coupling is deployed in different species. The impact of coupling on signal to noise ratio, spatial acuity, contrast sensitivity, absolute and increment threshold, retinal signal flow and colour discrimination is discussed while emphasising available data from a variety of vertebrate models spanning from lampreys to primates. We highlight the many gaps in our knowledge, persisting discrepancies in the literature, as well as some major unanswered questions on the actual extent and physiological role of cone-cone, rod-cone and rod-rod communication. Lastly, we point toward limited but intriguing evidence suggestive of the ancestral form of coupling among ciliary photoreceptors.

Interactions between compound and normal eye projections in dually innervated tectum: a study of optic nerve regeneration in Xenopus

Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 159-174
Author(s):  
Charles Straznicky ◽  
David Tay
Keyword(s):  
Optic Nerve ◽  
Nerve Regeneration ◽  
Compound Eye ◽  
Compound Eyes ◽  
Lateral Region ◽  
Optic Nerve Regeneration ◽  
Xenopus Embryos ◽  
Retinotectal Projections ◽  
Two Populations

Right compound eyes were formed in Xenopus embryos at tailbud stages by the fusion of two nasal (NN), two temporal (TT) or two ventral (VV) halves. The left eye was kept intact. Two to four weeks after metamorphosis the optic nerve from the intact eye was severed to induce bilateral optic nerve regeneration. The contralateral retinotectal projections from the compound eye and the induced ipsilateral projections from the intact eye to the same (dually innervated) tectum were studied by [3H]proline autoradiography and visuotectal mapping from 3 to 6 months after the postmetamorphic surgery. The results showed that the NN, TT and VV projections, in the presence of optic fibres from the intact eye failed to spread across the whole extent of the dually innervated tectum. Unexpectedly the bulk of the regenerating projection from the intact eye was confined to the previously uninnervated parts of the dually innervated tecta, the caudomedial region in TT, the rostrolateral region in NN and the lateral region in VV eye animals. The partial segregation of the two populations of optic fibres in the dually innervated tectum has been taken as a further indication of the role of fibre-fibre and fibre-tectum interactions in retinotectal map formation.

scholarly journals Disparate compound eyes of Cambrian radiodonts reveal their developmental growth mode and diverse visual ecology

2020 ◽  
Vol 6 (49) ◽  
pp. eabc6721
Author(s):  
John R. Paterson ◽  
Gregory D. Edgecombe ◽  
Diego C. García-Bellido
Keyword(s):  
Crucial Role ◽  
Compound Eye ◽  
Marine Ecosystems ◽  
Growth Mode ◽  
Compound Eyes ◽  
Suspension Feeding ◽  
Ecological Diversity ◽  
Crown Group ◽  
Developmental Growth

Radiodonts are nektonic stem-group euarthropods that played various trophic roles in Paleozoic marine ecosystems, but information on their vision is limited. Optical details exist only in one species from the Cambrian Emu Bay Shale of Australia, here assigned to Anomalocaris aff. canadensis. We identify another type of radiodont compound eye from this deposit, belonging to ‘Anomalocaris’ briggsi. This ≤4-cm sessile eye has >13,000 lenses and a dorsally oriented acute zone. In both taxa, lenses were added marginally and increased in size and number throughout development, as in many crown-group euarthropods. Both species’ eyes conform to their inferred lifestyles: The macrophagous predator A. aff. canadensis has acute stalked eyes (>24,000 lenses each) adapted for hunting in well-lit waters, whereas the suspension-feeding ‘A.’ briggsi could detect plankton in dim down-welling light. Radiodont eyes further demonstrate the group’s anatomical and ecological diversity and reinforce the crucial role of vision in early animal ecosystems.

scholarly journals Hydroxyethyl Starches

2009 ◽  
Vol 111 (1) ◽  
pp. 187-202 ◽  
Author(s):  
Martin Westphal ◽  
Michael F. M. James ◽  
Sibylle Kozek-Langenecker ◽  
Reto Stocker ◽  
Bertrand Guidet ◽  
...  
Keyword(s):  
Tissue Storage ◽  
High Doses ◽  
First And Second Generation ◽  
New Generation ◽  
Clinical Potential ◽  
The Impact ◽  
Hydroxyethyl Starches ◽  
Lower Molar

With the development of a new generation of hydroxyethyl starches (HES), there has been renewed interest in their clinical potential. High doses of first- and second-generation HES were associated with adverse effects on renal function, coagulation, and tissue storage, thereby limiting their clinical applicability. Newer HES products have lower molar substitution and in vivo molecular weight, resulting in more rapid metabolism and clearance. In this review article, the differences between HES generations are highlighted, with particular emphasis on the improved safety profile of the third generation products. These improvements have been achieved with no loss of efficacy, and they contradict the assumption that efficacy of HES solutions is directly linked to plasma concentration. The impact of source material on structure and pharmacokinetics is highlighted, and the role of the carrier solution is critically assessed.

High Speed Liquid Impact Onto Wetted Solid Surfaces

1994 ◽  
Vol 116 (2) ◽  
pp. 345-348 ◽  
Author(s):  
H. H. Shi ◽  
J. E. Field ◽  
C. S. J. Pickles
Keyword(s):  
Shock Wave ◽  
Liquid Layer ◽  
Solid Surface ◽  
High Speed ◽  
Shear Failure ◽  
Soda Lime ◽  
Liquid Jet ◽  
Soda Lime Glass ◽  
The Impact

The mechanics of impact by a high-speed liquid jet onto a solid surface covered by a liquid layer is described. After the liquid jet contacts the liquid layer, a shock wave is generated, which moves toward the solid surface. The shock wave is followed by the liquid jet penetrating through the layer. The influence of the liquid layer on the side jetting and stress waves is studied. Damage sites on soda-lime glass, PMMA (polymethylmethacrylate) and aluminium show the role of shear failure and cracking and provide evidence for analyzing the impact pressure on the wetted solids and the spatial pressure distribution. The liquid layer reduces the high edge impact pressures, which occur on dry targets. On wetted targets, the pressure is distributed more uniformly. Despite the cushioning effect of liquid layers, in some cases, a liquid can enhance material damage during impact due to penetration and stressing of surface cracks.

Research of Curved Artificial Compound Eyes Based on MEMS Technology

2011 ◽  
Vol 483 ◽  
pp. 407-410
Author(s):  
Qing He ◽  
Jing Quan Liu ◽  
Chun Sheng Yang
Keyword(s):  
Optical Imaging ◽  
Compound Eye ◽  
Imaging System ◽  
Curved Surface ◽  
Compound Eyes ◽  
Ccd Imaging ◽  
Mems Technology ◽  
Optical Imaging System ◽  
Imaging Sensor ◽  
The Impact

This paper studies the fabrication of curved surface artificial compound eyes and application in the optical imaging system. At present, the planar artificial compound eyes imaging system has narrow field of view angle because of its flat array structure of compound eyes. The preparation process of some existed curved surface artificial compound eyes is very complex and is very difficult to guarantee their exact curvature of the substrate. This paper presents a new method to fabricate the curved artificial compound eyes precisely based on MEMS technology The base diameter of the compound eye lens surface is 8mm and the height is 3mm, which includes thousands of compound eyelet. The diameter of the eyelet is 170μm, and the height is18μm. We use this curved artificial compound eyes and CCD imaging sensor assembly,aside from the impact of edge effects,we get the multi-angle and multi-dimensional photography to one object in the center of the imaging area. Therefore, the curved artificial compound eyes optical imaging system has a strong advantage in the dynamic spatial orientation.

scholarly journals 5G Radiation and Potential Risks to the Environment and Human Health

2021 ◽  
Vol 12 (6) ◽  
pp. 1689-1693
Author(s):  
Hasan J. Hasan, Ali J. Yosef, Haider Abed Hachem
Keyword(s):  
Human Health ◽  
High Speed ◽  
Rapid Development ◽  
Health And Safety ◽  
Radio Spectrum ◽  
The Public ◽  
Potential Risks ◽  
Public Exposure ◽  
New Generation ◽  
The Impact

      The rapid development in wireless communication technology and the urgent need to develop it has led to an increase in the public exposure to more radio spectrum frequencies. The mountain increases in terms of the damage caused by these wireless technologies for the 2G, 3G and 4G generations ending with the new technique, which is 5G. As a result of the urgent need for fast communications and wide packages of data, only a new generation of communications has emerged, which is 5G, which enjoys high speed and broadcasts in short waves and high frequency. There is great concern about the impact of these technologies on human health and safety. This technique works at relatively higher frequencies than the previously used technologies. This research sheds light on some of the expected harms of these technologies and the result of using these techniques, where the damages on the human body in general, the skin and the human eye in particular, are addressed, as well as their impact on the environment and plants in general.

Formation of cavities and microjets in liquids and their role in initiation and growth of explosion

1967 ◽  
Vol 298 (1452) ◽  
pp. 38-50 ◽  
Keyword(s):  
High Speed ◽  
Solid Surfaces ◽  
Pressure Waves ◽  
Liquid Explosive ◽  
Rarefaction Waves ◽  
Burning Zone ◽  
Rapid Transition ◽  
High Pressure Zone ◽  
The Impact

The role of discontinuities, such as bubbles of gas and cavities, in the initiation and growth of explosion in liquids has been studied experimentally by means of high speed framing photography. It is shown that micro Munroe jets can be formed at the surface of a gas bubble which has been trapped in the liquid explosive between two impacting surfaces and is being rapidly compressed. As the compression continues these jets are projected at high speed into the gas. Similar jets can be produced between two drops of explosive which are coalescing during impact. These jets may facilitate the initiation of burning both by increasing the impact velocity of the liquid and by dispersing the liquid within a pocket of compressed and heated gas. The reaction grows first as an accelerating burning. The pressure developed in this burning zone has, in the early stages, the effect of closing up and removing any cavities which may exist in the explosive directly ahead of the flame front, so that the reaction advances into a homogeneous zone of liquid that is free from discontinuities. It is not until the comparatively slow burning breaks through the homogeneous high pressure zone, and reaches a zone of liquid containing numerous cavities and bubbles, that the burning is able to transform quickly into a much faster and more violent explosion. The discontinuities are then able to sustain the rapid propagation of explosion. This region of discontinuities can be created in initially homogeneous liquids enclosed between solid surfaces by pressure waves which travel through the confining solids and ahead of the subsonic burning. If these pressure waves increase the distance between the confining surfaces substantially or are converted into rarefaction waves by reflexion, they can produce regions of tension in the unreacted liquid and disrupt it well ahead of the reaction zone. The bubbles of gas or cavities that are formed in this way by the precursor waves create an environment which is conducive to the rapid transition from burning to explosion.

scholarly journals The Energy Balance in Aluminum–Copper High-Speed Collision Welding

2021 ◽  
Vol 5 (2) ◽  
pp. 62
Author(s):  
Peter Groche ◽  
Benedikt Niessen
Keyword(s):  
High Speed ◽  
Bond Formation ◽  
High Strength ◽  
Weld Interface ◽  
High Speed Imaging ◽  
Collision Zone ◽  
High Speed Collision ◽  
New Generation ◽  
Lower Limits

Collision welding is a joining technology that is based on the high-speed collision and the resulting plastic deformation of at least one joining partner. The ability to form a high-strength substance-to-substance bond between joining partners of dissimilar metals allows us to design a new generation of joints. However, the occurrence of process-specific phenomena during the high-speed collision, such as a so-called jet or wave formation in the interface, complicates the prediction of bond formation and the resulting bond properties. In this paper, the collision welding of aluminum and copper was investigated at the lower limits of the process. The experiments were performed on a model test rig and observed by high-speed imaging to determine the welding window, which was compared to the ones of similar material parings from former investigation. This allowed to deepen the understanding of the decisive mechanisms at the welding window boundaries. Furthermore, an optical and a scanning electron microscope with energy dispersive X-ray analysis were used to analyze the weld interface. The results showed the important and to date neglected role of the jet and/or the cloud of particles to extract energy from the collision zone, allowing bond formation without melting and intermetallic phases.

scholarly journals Measuring Compound Eye Optics with Microscope and MicroCT Images

2020 ◽  
Author(s):  
John Paul Currea ◽  
Yash Sondhi ◽  
Akito Y Kawahara ◽  
Jamie Theobald
Keyword(s):  
Open Source ◽  
Compound Eye ◽  
Field Of View ◽  
Compound Eyes ◽  
Animal Kingdom ◽  
Efficient Tool ◽  
Internal Structures ◽  
Natural Range ◽  
Insight Into ◽  
Development And Evolution

The arthropod compound eye is the most prevalent eye type in the animal kingdom, with an impressive range of shapes and sizes. Studying its natural range of morphologies provides insight into visual ecology, development, and evolution. In contrast to the camera-type eyes we possess, external structures of compound eyes often reveal resolution, sensitivity, and field of view if the eye is spherical. Non-spherical eyes, however, require measuring internal structures using imaging technology like MicroCT (μCT). Thus far, there is no efficient tool to automate characterizing compound eye optics. We present two open-source programs: (1) the ommatidia detecting algorithm (ODA), which automatically measures ommatidia count and diameter, and (2) a μCT pipeline, which calculates anatomical acuity, sensitivity, and field of view across the eye by applying the ODA. We validate these algorithms on images, images of replicas, and μCT scans from eyes of ants, fruit flies, moths, and a bee.

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