The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Lin Zhong - One of the best experts on this subject based on the ideXlab platform.
-
Starfish efficient concurrency support for computer vision applications
International Conference on Mobile Systems Applications and Services, 2015Co-Authors: Robert Likamwa, Lin ZhongAbstract:Emerging wearable devices promise a multitude of computer vision-based applications that serve users without active engagement. However, vision algorithms are known to be resource-hungry; and modern mobile systems do not support concurrent application use of the camera. Toward supporting efficient concurrency of vision applications, we report Starfish, a split-process execution system that supports concurrent vision applications by allowing them to share computation and memory objects in a secure and efficient manner. Starfish splits the vision library from an application into a separate process, called the Core, which centrally serves all vision applications. The Core shares library call results among applications, eliminating redundant computation and memory use. Starfish supports unmodified applications and unmodified libraries without needing their source code, and guarantees correctness to the applications. In doing so, Starfish improves both the performance and energy efficiency of concurrent vision applications. Using a prototype implementation on Google Glass, we experimentally demonstrate that Starfish reduces the time spent processing repeated vision library calls by 71% - 97%. When running two to ten concurrent face recognition applications at 0.3 frames per second, Starfish reduces CPU utilization by more than 42% - 80%. Notably, this keeps CPU utilization below 13%, even as the number of applications increases. This reduces system power consumption by 19% - 58%, as Starfish maintains a power consumption at approximately 1210 mW while running the concurrent application workloads.
-
MobiSys - Starfish: Efficient Concurrency Support for Computer Vision Applications
Proceedings of the 13th Annual International Conference on Mobile Systems Applications and Services, 2015Co-Authors: Robert Likamwa, Lin ZhongAbstract:Emerging wearable devices promise a multitude of computer vision-based applications that serve users without active engagement. However, vision algorithms are known to be resource-hungry; and modern mobile systems do not support concurrent application use of the camera. Toward supporting efficient concurrency of vision applications, we report Starfish, a split-process execution system that supports concurrent vision applications by allowing them to share computation and memory objects in a secure and efficient manner. Starfish splits the vision library from an application into a separate process, called the Core, which centrally serves all vision applications. The Core shares library call results among applications, eliminating redundant computation and memory use. Starfish supports unmodified applications and unmodified libraries without needing their source code, and guarantees correctness to the applications. In doing so, Starfish improves both the performance and energy efficiency of concurrent vision applications. Using a prototype implementation on Google Glass, we experimentally demonstrate that Starfish reduces the time spent processing repeated vision library calls by 71% - 97%. When running two to ten concurrent face recognition applications at 0.3 frames per second, Starfish reduces CPU utilization by more than 42% - 80%. Notably, this keeps CPU utilization below 13%, even as the number of applications increases. This reduces system power consumption by 19% - 58%, as Starfish maintains a power consumption at approximately 1210 mW while running the concurrent application workloads.
Anders Garm - One of the best experts on this subject based on the ideXlab platform.
-
Sensory Biology of Starfish-With Emphasis on Recent Discoveries in their Visual Ecology.
Integrative and comparative biology, 2017Co-Authors: Anders GarmAbstract:Asteroidea, Starfish, constitutes a major part of the macrobenthos in most marine environments. Being members of the echinoderms, they have a nervous system with no well-defined central nervous system. Accordingly, Starfish are assumed to pick up rather limited information from the surroundings, and it is also often assumed that most of their behaviors are guided by olfaction. Here, the sensory biology of Starfish is reviewed in order to evaluate these assumptions. There is a vast amount of behavioral data dealing with mechanoreception, chemoreception, and combinations of the two (chemosensory-mediated rheotaxis), but the receptors have not yet been identified and almost nothing is known about the physiology behind these senses. What can be concluded from the available data is that Starfish possess a sense of touch, some are able to sense gravity and many display positive rheotaxis, moving up currents. A number of Starfish species use olfaction during foraging and prey localization. Interestingly, eyes are also present in most Starfish, and recent studies have documented that in Linckia laevigata and Acanthaster planci vision plays a major role in seeking out their feeding grounds. The physiology and structure of the eyes filter out small moving objects while optimizing the contrast between the large stationary objects (e.g., coral boulders in the habitat) and the surrounding water. These new results demonstrate the importance of controlling the visual environment when conducting experiments on Starfish behavior.
-
Crown-of-thorns Starfish have true image forming vision.
Frontiers in zoology, 2016Co-Authors: Ronald Petie, Anders Garm, Michael R. HallAbstract:Photoreceptors have evolved numerous times giving organisms the ability to detect light and respond to specific visual stimuli. Studies into the visual abilities of the Asteroidea (Echinodermata) have recently shown that species within this class have a more developed visual sense than previously thought and it has been demonstrated that Starfish use visual information for orientation within their habitat. Whereas image forming eyes have been suggested for Starfish, direct experimental proof of true spatial vision has not yet been obtained. The behavioural response of the coral reef inhabiting crown-of-thorns Starfish (Acanthaster planci) was tested in controlled aquarium experiments using an array of stimuli to examine their visual performance. We presented Starfish with various black-and-white shapes against a mid-intensity grey background, designed such that the animals would need to possess true spatial vision to detect these shapes. Starfish responded to black-and-white rectangles, but no directional response was found to black-and-white circles, despite equal areas of black and white. Additionally, we confirmed that Starfish were attracted to black circles on a white background when the visual angle is larger than 14°. When changing the grey tone of the largest circle from black to white, we found responses to contrasts of 0.5 and up. The Starfish were attracted to the dark area’s of the visual stimuli and were found to be both attracted and repelled by the visual targets. For crown-of-thorns Starfish, visual cues are essential for close range orientation towards objects, such as coral boulders, in the wild. These visually guided behaviours can be replicated in aquarium conditions. Our observation that crown-of-thorns Starfish respond to black-and-white shapes on a mid-intensity grey background is the first direct proof of true spatial vision in Starfish and in the phylum Echinodermata.
-
Visual orientation by the crown-of-thorns Starfish (Acanthaster planci)
Coral Reefs, 2016Co-Authors: Ronald Petie, Michael R. Hall, Mia Hyldahl, Anders GarmAbstract:Photoreception in echinoderms has been known for over 200 years, but their visual capabilities remain poorly understood. As has been reported for some asteroids, the crown-of-thorns Starfish (Acanthaster planci) possess a seemingly advanced eye at the tip of each of its 7–23 arms. With such an array of eyes, the Starfish can integrate a wide field of view of its surroundings. We hypothesise that, at close range, orientation and directional movements of the crown-of-thorns Starfish are visually guided. In this study, the eyes and vision of A. planci were examined by means of light microscopy, electron microscopy, underwater goniometry, electroretinograms and behavioural experiments in the animals’ natural habitat. We found that only animals with intact vision could orient to a nearby coral reef, whereas blinded animals, with olfaction intact, walked in random directions. The eye had peak sensitivity in the blue part (470 nm) of the visual spectrum and a narrow, horizontal visual field of approximately 100° wide and 30° high. With approximately 250 ommatidia in each adult compound eye and average interommatidial angles of 8°, crown-of-thorns Starfish have the highest spatial resolution of any Starfish studied to date. In addition, they have the slowest vision of all animals examined thus far, with a flicker fusion frequency of only 0.6–0.7 Hz. This may be adaptive as fast vision is not required for the detection of stationary objects such as reefs. In short, the eyes seem optimised for detecting large, dark, stationary objects contrasted against an ocean blue background. Our results show that the visual sense of the crown-of-thorns Starfish is much more elaborate than has been thus far appreciated and is essential for orientation and localisation of suitable habitats.
Morgan S Pratchett - One of the best experts on this subject based on the ideXlab platform.
-
Habitat associations of settlement-stage crown-of-thorns Starfish on Australia’s Great Barrier Reef
Coral Reefs, 2020Co-Authors: Jennifer C. Wilmes, Daniel Schultz, Andrew S. Hoey, Vanessa Messmer, Morgan S PratchettAbstract:Population irruptions of crown-of-thorns Starfish (Acanthaster spp.) contribute greatly to the degradation of coral reefs throughout the Indo-Pacific. Effective management of these population irruptions is limited, in part, by incomplete knowledge of their early life history. Importantly, there are very limited data on the distribution and abundance of newly settled crown-of-thorns Starfish (0 + Starfish, in their first year since settlement). Extensive sampling was conducted around the circumference of three distinct mid-shelf reefs (at 1–18 m depths) in the central Great Barrier Reef (GBR), during active population irruptions, in May–June 2017, to quantify the occurrence and densities of settlement-stage Starfish (2–65 mm diameter) and relate patterns of abundance to distinct habitat features at the scale of individual reefs. Overall, 140 settlement-stage Starfish were detected across 1242 quadrats (1 m2). Settlement-stage Starfish were recorded from 31 out of 42 sites (73.8%) at mean densities of 0–0.77 Starfish m−2. Both estimated densities and the likelihood of occurrence of settlement-stage Starfish within quadrats increased overall with the proportion of coral rubble (and dead intact corals), were greatest at intermediate depths (8–14 m), but decreased with the proportion of live hard coral. At the scale of individual reefs, settlement-stage Starfish occurred most frequently in south-western and northern fore reef habitats. Our results suggest that settlement and/or early post-settlement survival of crown-of-thorns Starfish is greatest in relatively shallow waters of obliquely exposed fore reef habitats where there is high cover of coral rubble. The specific occurrence of these habitat types (within spur and groove systems and rubble slips) provides an opportunity to concentrate searches and increase effective sampling of settlement-stage Starfish, though these habitats are relatively widespread and unlikely to constrain the population replenishment or population irruptions of crown-of-thorns Starfish on the GBR.
-
Relationships between size and reproductive output in the crown-of-thorns Starfish
Marine Biology, 2016Co-Authors: Russell C. Babcock, David A. Milton, Morgan S PratchettAbstract:Studies of pre-spawning crown-of-thorns Starfish Acanthaster (COTS) collected from the Great Barrier Reef showed average female gonad mass of 16 % (±8 s.d.) and for males 12 % (±6 s.d.). In females up to 34 % of the body mass could be devoted to gonad. Based on these data, we also derived relationships between diameter gonad weight and reproductive output for both male and female Starfish. Due to the large average size of individuals in this study (39.2 ± 0.3 cm diameter), the potential oocyte production of females was between 29 and 38 million eggs per season for average size Starfish. The highest oocyte production was estimated to be >100 million oocytes, which is the highest ever recorded for an individual female Starfish. These relationships imply that the largest Acanthaster reported may have fecundities greater than 200 million eggs per season. The gonad mass of male Starfish is similarly high, and in combination with measured concentrations of sperm exuded from the gonopore (5.2 × 1010 ml−1) the sperm output of an average sized male is estimated to be 1.1 × 1013 sperm. This high level of sperm production may be a key factor allowing this species to sustain itself and even initiate outbreaks at low population densities. We suggest that management targets for maintaining COTS at pre-outbreak thresholds should take account of Starfish size as well as Starfish density, especially given extreme reproductive potential of large Starfish in pre-outbreak populations.
-
influence of coral symbionts on feeding preferences of crown of thorns Starfish acanthaster planci in the western pacific
Marine Ecology Progress Series, 2001Co-Authors: Morgan S PratchettAbstract:The crown-of-thorns Starfish Acanthaster planci (L.) is well adapted to feed on a wide range of different corals, but often exhibits striking preference for a small suite of available prey species. Numerous theories have been forwarded to explain its feeding preferences, but many of these theories have not been tested. In this study, I test whether coral symbionts significantly affect the feeding preferences of crown-of-thorns Starfish by removing symbionts from replicate colonies of 6 different coral species. Crown-of-thorns Starfish had a clearly defined hierarchy of preference for the 6 different corals when these contained symbionts (Acropora gemmifera > A. nasuta = A. loripes > Seriatopora hystrix > Pocillopora damicornis > Stylophora pistillata). However, when coral symbionts were removed, then the Starfish readily consumed all 6 corals and did not exhibit any significant selectivity. Further manipulation of symbiont assemblages showed that the trapeziid crabs (Tetralia and Trapezia species) were the most effective of the various coral symbionts in deterring Starfish from feeding on their host colony. Moreover, those corals that were least preferred by crown-of-thorns Starfish contained the largest and most powerful species of Trapezia (T. cymodoce), whereas the most preferred corals contained only very small Tetralia spp. crabs. Further experimentation is required to assess the generality of these results, but for the 6 coral species tested, it is clear that coral symbionts (and particularly trapeziid crabs) do have a marked influence on the feeding preferences of the crown-of-thorns Starfish.
Robert Likamwa - One of the best experts on this subject based on the ideXlab platform.
-
Starfish efficient concurrency support for computer vision applications
International Conference on Mobile Systems Applications and Services, 2015Co-Authors: Robert Likamwa, Lin ZhongAbstract:Emerging wearable devices promise a multitude of computer vision-based applications that serve users without active engagement. However, vision algorithms are known to be resource-hungry; and modern mobile systems do not support concurrent application use of the camera. Toward supporting efficient concurrency of vision applications, we report Starfish, a split-process execution system that supports concurrent vision applications by allowing them to share computation and memory objects in a secure and efficient manner. Starfish splits the vision library from an application into a separate process, called the Core, which centrally serves all vision applications. The Core shares library call results among applications, eliminating redundant computation and memory use. Starfish supports unmodified applications and unmodified libraries without needing their source code, and guarantees correctness to the applications. In doing so, Starfish improves both the performance and energy efficiency of concurrent vision applications. Using a prototype implementation on Google Glass, we experimentally demonstrate that Starfish reduces the time spent processing repeated vision library calls by 71% - 97%. When running two to ten concurrent face recognition applications at 0.3 frames per second, Starfish reduces CPU utilization by more than 42% - 80%. Notably, this keeps CPU utilization below 13%, even as the number of applications increases. This reduces system power consumption by 19% - 58%, as Starfish maintains a power consumption at approximately 1210 mW while running the concurrent application workloads.
-
MobiSys - Starfish: Efficient Concurrency Support for Computer Vision Applications
Proceedings of the 13th Annual International Conference on Mobile Systems Applications and Services, 2015Co-Authors: Robert Likamwa, Lin ZhongAbstract:Emerging wearable devices promise a multitude of computer vision-based applications that serve users without active engagement. However, vision algorithms are known to be resource-hungry; and modern mobile systems do not support concurrent application use of the camera. Toward supporting efficient concurrency of vision applications, we report Starfish, a split-process execution system that supports concurrent vision applications by allowing them to share computation and memory objects in a secure and efficient manner. Starfish splits the vision library from an application into a separate process, called the Core, which centrally serves all vision applications. The Core shares library call results among applications, eliminating redundant computation and memory use. Starfish supports unmodified applications and unmodified libraries without needing their source code, and guarantees correctness to the applications. In doing so, Starfish improves both the performance and energy efficiency of concurrent vision applications. Using a prototype implementation on Google Glass, we experimentally demonstrate that Starfish reduces the time spent processing repeated vision library calls by 71% - 97%. When running two to ten concurrent face recognition applications at 0.3 frames per second, Starfish reduces CPU utilization by more than 42% - 80%. Notably, this keeps CPU utilization below 13%, even as the number of applications increases. This reduces system power consumption by 19% - 58%, as Starfish maintains a power consumption at approximately 1210 mW while running the concurrent application workloads.
David J. Carroll - One of the best experts on this subject based on the ideXlab platform.
-
Starfish as a Model System for Analyzing Signal Transduction During Fertilization.
Results and problems in cell differentiation, 2018Co-Authors: Emily Wiseman, Lauren Bates, Altair Dubé, David J. CarrollAbstract:The Starfish oocyte and egg offer advantages for use as a model system for signal transduction research. Some of these have been recognized for over a century, including the ease of procuring gametes, in vitro fertilization, and culturing the embryos. New advances, particularly in genomics, have also opened up opportunities for the use of these animals. In this chapter, we give a few examples of the historical use of the Starfish for research in cell biology and then describe some new areas in which we believe the Starfish can contribute to our understanding of signal transduction—particularly in fertilization.