Traditional Tracing Methods Research Articles

Tracing sources of inorganic suspended particulate matter in the Great Barrier Reef lagoon, Australia

Water clarity on the inshore Great Barrier Reef (GBR) is greatly influenced by terrestrial runoff of suspended particulate matter (SPM). Catchment sediment tracing studies often do not extend into the marine environment, preventing the analysis of preferential marine transport. This study employs novel collection and sediment tracing techniques to examine the transport of the terrigenous ‘mineral’ component of plume SPM within the GBR lagoon for two flood events. Utilising geochemical, radionuclide and clay mineral analysis, we trace terrigenous mineral sediments > 100 km from the river mouth. We show that the SPM geochemistry is highly influenced by particle-size fractionation, desorption, and dilution within the plume, rendering traditional tracing methods unviable. However, the ratios of rare earth elements (REE) to thorium (Th) provide stable tracers of mineral SPM transported across the catchment to marine continuum and allow the identification of discrete catchment sources for each flood event. Plume sediment radionuclides are also stable and consistent with sub-surface erosion sources.

Research and Modeling Electronic Data Tracing Scheme Based on Blockchain

From the point of view that the traditional electronic data (documents in image, PDF, etc) is difficult to track and trace, taking image copyright as an example, this paper studies a new scheme to solve the problem of replication detection and traceability based on blockchain. With the decentralization and trust removing of blockchain, both copyright storage and evidence of infringement are stored in a tamper proof and transparent way. Based on the judgment of image similarity, a “resource reverse tracing strategy” is designed to control the infringement timely. The infringement evidence can reach the creator quickly, which provides convenience for the creator’s rights protection. This method changes traditional tracing methods of image copyright. Also, it can be applied to the tracing problem of reuse of electronic invoice, short video, music, etc, and brings new ideas for the related problem.

Re-contacting participants from the longitudinal Belfast youth development study (BYDS) after a decade using electronic tracing

ABSTRACT The longitudinal Belfast Youth Development Study (BYDS) followed a group of young people from age 11 to 21 years (from 2001 to 2011), charting their experiences of substance use, offending, education, and peer and family relationships. This allowed the investigation of risk and protective factors associated with different types of behavioural patterns and outcomes in adolescence and emerging adulthood. A feasibility study was carried out from 2018 to 2019 to test the success rate of electronically tracing 4,195 participants after almost a decade, in anticipation of carrying out an additional wave of data collection. The projected trace rate obtained using standard and forensic electronic tracing methods was considerably higher (86%) than traditional tracing methods (10%) for getting up-to-date contact details on participants. The electronic tracing methods were also cheaper (£9.72 per person traced) than traditional tracing methods (£20.62 per person traced). These findings will help maximise the potential of longitudinal social research.

Weakly Supervised Neuron Reconstruction From Optical Microscopy Images With Morphological Priors.

Manually labeling neurons from high-resolution but noisy and low-contrast optical microscopy (OM) images is tedious. As a result, the lack of annotated data poses a key challenge when applying deep learning techniques for reconstructing neurons from noisy and low-contrast OM images. While traditional tracing methods provide a possible way to efficiently generate labels for supervised network training, the generated pseudo-labels contain many noisy and incorrect labels, which lead to severe performance degradation. On the other hand, the publicly available dataset, BigNeuron, provides a large number of single 3D neurons that are reconstructed using various imaging paradigms and tracing methods. Though the raw OM images are not fully available for these neurons, they convey essential morphological priors for complex 3D neuron structures. In this paper, we propose a new approach to exploit morphological priors from neurons that have been reconstructed for training a deep neural network to extract neuron signals from OM images. We integrate a deep segmentation network in a generative adversarial network (GAN), expecting the segmentation network to be weakly supervised by pseudo-labels at the pixel level while utilizing the supervision of previously reconstructed neurons at the morphology level. In our morphological-prior-guided neuron reconstruction GAN, named MP-NRGAN, the segmentation network extracts neuron signals from raw images, and the discriminator network encourages the extracted neurons to follow the morphology distribution of reconstructed neurons. Comprehensive experiments on the public VISoR-40 dataset and BigNeuron dataset demonstrate that our proposed MP-NRGAN outperforms state-of-the-art approaches with less training effort.

Ray Tracing Method of Gradient Refractive Index Medium Based on Refractive Index Step

For gradient refractive index media with large refractive index gradients, traditional ray tracing methods based on refined elements or spatial geometric steps have problems such as low tracing accuracy and efficiency. The ray tracing method based on refractive index steps proposed in this paper can effectively solve this problem. This method uses the refractive index step to replace the spatial geometric step. The starting point and the end point of each ray tracing step are on the constant refractive-index surfaces. It avoids the problem that the traditional tracing method cannot adapt to the area of sudden change in the refractive index and the area where the refractive index changes sharply. Therefore, a suitable distance can be performed in the iterative process. It can achieve high-efficiency and precise ray tracing in areas whether the refractive index changes slowly or sharply. According to the comparison of calculation examples, this method can achieve a tracing accuracy of 10−5 mm. The speed and precision of ray tracing are better than traditional methods.

Simultaneous inversion of concentrations of POC and its endmembers in lakes: A novel remote sensing strategy

Data on the concentration of particulate organic carbon (POC) and its endmembers provide a basis for the characterisation of lake biogeochemical cycles. Here, a novel remote sensing strategy (the SCPOC algorithm) was developed to determine total POC concentrations, as well as terrestrial and endogenous POC concentrations in lakes. This strategy provides a successful example for the combination of isotope tracer and remote sensing technology. First, we obtained the terrestrial and endogenous POC concentration at the sampling point based on isotope tracing technology. Afterwards, we established a relationship between the phytoplankton absorption coefficient and the endogenous POC concentration (Cend), and applied a semi-analytical algorithm to invert the Cend value. Finally, the POC source ratio model and Cend value were combined to obtain the POC concentration (CPOC) and terrestrial POC (Cter). The results of synchronisation verification based on ocean and land colour instrument (OLCI) images show that the SCPOC algorithm has high Cend, Cter, and CPOC inversion accuracy, with MAPE values of 26.07%, 30.43%, and 42.28%, respectively. In fact, the SCPOC algorithm not only improved the accuracy of lake POC mapping, but also fills the gap of optical retrieval of POC endmember concentrations. Additionally, data from the OLCI images indicated that the studied lakes were dominated by external POC. However, because of the greater contribution of algal blooms to POC, this dominant advantage weakens in summer, although the terrestrial organic carbon carried by rainfall runoff also affects lake POC composition. Different POC sources have different ecological roles in lakes, and the superior POC end-element estimation capability of the SCPOC algorithm can not only be used as a supplement to traditional tracing methods, but also provides accurate spatial data for lake management.

The reliability of an easy measuring method for abutment convergence angle with a computer-aided design (CAD) system.

PURPOSEThe purpose of this study was to evaluate the intra-rater reliability and inter-rater reliability of three different methods using a drawing protractor, a digital protractor after tracing, and a CAD system.MATERIALS AND METHODSTwenty-four artificial abutments that had been prepared by dental students were used in this study. Three dental students measured the convergence angles by each method three times. Bland-Altman plots were applied to examine the overall reliability by comparing the traditional tracing method with a new method using the CAD system. Intraclass Correlation Coefficients (ICC) evaluated intra-rater reliability and inter-rater reliability.RESULTSAll three methods exhibited high intra-rater and inter-rater reliability (ICC>0.80, P<.05). Measurements with the CAD system showed the highest intra-rater reliability. In addition, it showed improved inter-rater reliability compared with the traditional tracing methods.CONCLUSIONBased on the results of this study, the CAD system may be an easy and reliable tool for measuring the abutment convergence angle.

An Efficient Method for Calculating the Intersection Curve between a Ruled Surface and a Plane

Based on the unique geometric features of the ruled surface, a new efficient algorithm for ruled surface/plane intersection is proposed. The ruled surface is firstly dispersed into a set of line segments, and the ruled surface/plane intersection is transformed to the intersection of a group line segments with a plane. Then a set of ordered intersection points can be obtained by the proposed line/plane intersection algorithm. According to the serial number of every intersection point, all the intersection points are grouped and reorganized. Each group point corresponds to an intersection curve. All the intersection curves can be reconstructed by curve interpolation. Compared with the traditional tracing method, the proposed algorithm can avoid complex calculation including initial points searching and intersection points sorting, which is more efficient and stable.

Gene transfer in the nervous system and implications for transsynaptic neuronal tracing

Importance of the field: Neuronal circuitries are determined by specific synaptic connections and they provide the cellular basis of cognitive processes and behavioral functions. To investigate neuronal circuitries, tracers are typically used to identify the original neurons and their projection targets.Areas covered in this review: Traditional tracing methods using chemical tracers have major limitations such as non-specificity. In this review, we highlight novel genetic tracing approaches that enable visualization of specific neuronal pathways by introducing cDNA encoding a transsynaptic tracer. In contrast to conventional tracing methods, these genetic approaches use cell-type-specific promoters to express transsynaptic tracers such as wheat germ agglutinin and C-terminal fragment of tetanus toxin, which allows labeling of either the input or output populations and connections of specific neuronal type.What the reader will gain: Specific neuronal circuit information by these genetic approaches will allow more precise, comprehensive and novel information about individual neural circuits and their function in normal and diseased brains.Take home message: Using tracer gene transfer, neuronal circuit plasticity after traumatic injury or neurodegenerative diseases can be visualized. Also, this can provide a good marker for evaluation of therapeutic effects of neuroprotective or neurotrophic agents.