Low-latency vision-based fiducial detection and localisation for object tracking

Real-time vision systems are widely-used in construction and manufacturing industries. A significant proportion of computational resources of such systems is used in fiducial identification and localisation for motion tracking of moving targets. The requirement is to localise a pattern in an image captured by the vision system precisely, accurately, and with a minimum available computation time. As such, this paper presents a class of patterns and, accordingly, proposes an algorithm to fulfil the requirement. Here, the patterns are designed using circular patches of concentric circles to increase the probability of detection and reduce cases of false detection. In the detection algorithm, the image captured by the vision system is first scaled down for computationally-effective processing. The scaled image is then separated by filtering only the colour components, which are made up of outer circular patches in the proposed pattern. A blob detection algorithm is then implemented for identifying inner circular patches. The inner circles are then localised in the image by using the colour information obtained. Finally, the localised pattern, along with the camera and distortion matrix of the vision system, is applied in a perspective-n-point solving algorithm to estimate the marker orientation and position in the global coordinate system. Our system shows significant enhancement in performance of fiducial detection and identification and achieves the required latency of less than ten milliseconds. Thus, it can be used for infrastructure monitoring in many applications that involve high-speed real-time vision systems

Roboteye technology for thermal target tracking using predictive control

© ISARC 2018 - 35th International Symposium on Automation and Robotics in Construction and International AEC/FM Hackathon: The Future of Building Things. All rights reserved. Thermal cameras are widely used in the fatigue analysis of mechanical structures using the thermoelastic effect. Nevertheless, such analysis is hampered due to blurry images resulting from the motion of structure-under-test. To address the issue this paper presents a system that utilizes robotic vision and predictive control. The system comprises of a thermal camera, a vision camera, a RobotEye, and a fiducial detection system. A marker is attached to a thermal target in order to estimate its position and orientation using the proposed detection system. To predict the future position of the thermal moving object, a Kalman filter is used. Finally, the Model Predictive Control (MPC) approach is applied to generate commands for the robot to follow the target. Results of the tracking by MPC are included in this paper along with the performance evaluation of the whole system. The evaluation clearly shows the improvement in the tracking performance of the development for thermal structural analysis

Across the great divide: genetic forensics reveals misidentification of endangered cutthroat trout populations

Accurate assessment of species identity is fundamental for conservation biology. Using molecular markers from the mitochondrial and nuclear genomes, we discovered that many putatively native populations of greenback cutthroat trout (Oncorhynchus clarkii stomias) comprised another subspecies of cutthroat trout, Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). The error can be explained by the introduction of Colorado River cutthroat trout throughout the native range of greenback cutthroat trout in the late 19th and early 20th centuries by fish stocking activities. Our results suggest greenback cutthroat trout within its native range is at a higher risk of extinction than ever before despite conservation activities spanning more than two decades

Islands of conformational stability for Filopodia

Filopodia are long, thin protrusions formed when bundles of fibers grow outwardly from a cell surface while remaining closed in a membrane tube. We study the subtle issue of the mechanical stability of such filopodia and how this depends on the deformation of the membrane that arises when the fiber bundle adopts a helical configuration. We calculate the ground state conformation of such filopodia, taking into account the steric interaction between the membrane and the enclosed semiflexible fiber bundle. For typical filopodia we find that a minimum number of fibers is required for filopodium stability. Our calculation elucidates how experimentally observed filopodia can obviate the classical Euler buckling condition and remain stable up to several tens of . We briefly discuss how experimental observation of the results obtained in this work for the helical-like deformations of enclosing membrane tubes in filopodia could possibly be observed in the acrosomal reactions of the sea cucumber Thyone, and the horseshoe crab Limulus. Any realistic future theories for filopodium stability are likely to rely on an accurate treatment of such steric effects, as analysed in this work

Synthetic opioids: a review and clinical update

The term ‘opioids’ refers to both the natural compounds (‘opiates’) which are extracted from the opium poppy plant ( Papaver somniferum) and their semi-synthetic and synthetic derivatives. They all possess relatively similar biochemical profiles and interact with the opioid receptors within the human body to produce a wide range of physiological effects. They have historically been used for medicinal purposes, their analgesic and sedative effects, and in the management of chronic and severe pain. They have also been used for non-medicinal and recreational purposes to produce feelings of relaxation, euphoria and well-being. Over the last decade, the emergence of an illegal market in new synthetic opioids has become a major global public health issue, associated with a substantial increase in unintentional overdoses and drug-related deaths. Synthetic opioids include fentanyl, its analogues and emerging non-fentanyl opioids. Their popularity relates to changes in criminal markets, pricing, potency, availability compared to classic opioids, ease of transport and use, rapid effect and lack of detection by conventional testing technologies. This article expands on our previous review on new psychoactive substances. We now provide a more in-depth review on synthetic opioids and explore the current challenges faced by people who use drugs, healthcare professionals, and global public health systems

Application of prescribing recommendations in older people with reduced kidney function : a cross-sectional study in general practice

BACKGROUND: Kidney function reduces with age, increasing the risk of harm from increased blood levels of many medicines. Although estimated glomerular filtration rate (eGFR) is reported for prescribing decisions in those aged ≥65 years, creatinine clearance (Cockcroft-Gault) gives a more accurate estimate of kidney function. AIM: To explore the extent of prescribing outside recommendations for people aged ≥65 years with reduced kidney function in primary care and to assess the impact of using eGFR instead of creatinine clearance to calculate kidney function. DESIGN AND SETTING: A cross-sectional survey of anonymised prescribing data in people aged ≥65 years from all 80 general practices (70 900 patients) in a north of England former primary care trust. METHOD: The prevalence of prescribing outside recommendations was analysed for eight exemplar drugs. Data were collected for age, sex, actual weight, serum creatinine, and eGFR. Kidney function as creatinine clearance (Cockcroft-Gault) was calculated using actual body weight and estimated ideal body weight. RESULTS: Kidney function was too low for recommended prescribing in 4-40% of people aged ≥65 years, and in 24-80% of people aged ≥85 years despite more than 90% of patients having recent recorded kidney function results. Using eGFR overestimated kidney function for 3-28% of those aged ≥65 years, and for 13-58% of those aged ≥85 years. Increased age predicted higher odds of having a kidney function estimate too low for recommended prescribing of the study drugs. CONCLUSION: Prescribing recommendations when kidney function is reduced are not applied for many people aged ≥65 years in primary care. Using eGFR considerably overestimates kidney function for prescribing and, therefore, creatinine clearance (Cockcroft-Gault) should be assessed when prescribing for these people. Interventions are needed to aid prescribers when kidney function is reduced

Dose modelling comparison for terrestrial biota: IAEA EMRAS II Biota Working Group's Little Forest Burial Ground scenario

Radiological doses to terrestrial biota have been examined in a model inter-comparison study that emphasised the identification of factors causing variability in dose estimation. Radiological dose rates were modelled for ten species representing a diverse range of terrestrial plant and animals with varying behavioural and physical attributes. Dose to these organisms may occur from a range of gamma (Co-60, Cs-137), beta (Sr-90) and alpha (Th-232, U-234 and U-238, Pu-238, Pu-239/240 and Am-241) emitting radionuclides. Whilst the study was based on a specific site - the Little Forest Burial Ground, New South Wales, and Australia - it was intended to be representative of conditions at sites throughout the world where low levels of radionuclides exist in soil due to waste disposal or similar activities

Sporormiella as a tool for detecting the presence of large herbivores in the Neotropics

The reliability of using the abundance of Sporormiella spores as a proxy for the presence and abundance of megaherbivores was tested in southern Brazil. Mud-water interface samples from nine lakes, in which cattle-use was categorized as high, medium, or low, were assayed for Sporormiella representation. The sampling design allowed an analysis of both the influence of the number of animals using the shoreline and the distance of the sampling site from the nearest shoreline. Sporormiella was found to be a reliable proxy for the presence of large livestock. The concentration and abundance of spores declined from the edge of the lake toward the center, with the strongest response being in sites with high livestock use. Consistent with prior studies in temperate regions, we find that Sporormiella spores are a useful proxy to study the extinction of Pleistocene megafauna or the arrival of European livestock in Neotropical landscapes

Direct and Indirect Induction of a Compensatory Phenotype that Alleviates the Costs of an Inducible Defense

Organisms often exhibit phenotypic plasticity in multiple traits in response to impending environmental change. Multiple traits phenotypic plasticity is complex syndrome brought on by causal relations in ecological and physiological context. Larvae of the salamander Hynobius retardatus exhibit inducible phenotypic plasticity of two traits, when at risk of predation by dragonfly larvae. One induced phenotype is an adaptive defense behaviour, i.e., stasis at the bottom of water column, directly triggered by the predation risk. Another one is a compensatory phenotype, i.e., enlarged external gills, for an unavoidable cost (hypoxia) associated with the induced defense. We identified two ways by which this compensatory phenotype could be induced. The compensatory phenotype is induced in response to not only the associated hypoxic conditions resulting from the induced defense but also the most primary but indirect cause, presence of the predator