Unveiling NRlncRNAs as prognostic biomarkers and therapeutic targets for head-and-neck squamous cell carcinoma through machine learning.

Head-and-neck squamous cell carcinoma (HNSCC) patients often exhibit insensitivity to immunotherapy, leading to treatment failure. Identifying potential biomarkers that can predict prognosis and improve the efficacy of treatment is crucial. In this study, we aimed to identify necroptosis-related long noncoding RNAs (NRlncRNAs) as potential therapeutic targets to improve the prognosis of HNSCC patients. By exploring the Genotype-Tissue Expression Project (GTEx) and the Cancer Genome Atlas (TCGA) databases, we identified NRlncRNAs and developed a risk model comprising 17 NRlncRNAs to predict the prognosis of HNSCC patients and to classify patients into two clusters based on their expression levels. We conducted various analyses, such as the Kaplan-Meier analysis, GSEA and IC50 prediction, to evaluate the differences in sensitivity to immunotherapy between the two clusters. Our findings suggest that NRlncRNAs have potential as therapeutic targets for improving the prognosis of HNSCC patients, and that individualized treatment approaches based on NRlncRNA expression levels can improve the sensitivity of immunotherapy and overall treatment outcomes. This study highlights new perspectives within clinical cancer informatics and provides insight into potential therapeutic strategies for HNSCC patients.

Quantifying the spatial spillover effects of non-pharmaceutical interventions on pandemic risk.

BACKGROUND: Non-pharmaceutical interventions (NPIs) implemented in one place can affect neighboring regions by influencing people's behavior. However, existing epidemic models for NPIs evaluation rarely consider such spatial spillover effects, which may lead to a biased assessment of policy effects. METHODS: Using the US state-level mobility and policy data from January 6 to August 2, 2020, we develop a quantitative framework that includes both a panel spatial econometric model and an S-SEIR (Spillover-Susceptible-Exposed-Infected-Recovered) model to quantify the spatial spillover effects of NPIs on human mobility and COVID-19 transmission. RESULTS: The spatial spillover effects of NPIs explain [Formula: see text] [[Formula: see text] credible interval: 52.8-[Formula: see text]] of national cumulative confirmed cases, suggesting that the presence of the spillover effect significantly enhances the NPI influence. Simulations based on the S-SEIR model further show that increasing interventions in only a few states with larger intrastate human mobility intensity significantly reduce the cases nationwide. These region-based interventions also can carry over to interstate lockdowns. CONCLUSIONS: Our study provides a framework for evaluating and comparing the effectiveness of different intervention strategies conditional on NPI spillovers, and calls for collaboration from different regions.

CERCAM is a prognostic biomarker associated with immune infiltration of macrophage M2 polarization in head and neck squamous carcinoma.

PURPOSE: This study aimed to investigate the relevance of cerebral endothelial cell adhesion molecule (CERCAM) expression to head and neck squamous cell carcinoma (HNSCC) prognosis and immune infiltration by macrophage M2 polarization. METHODS: Timer, UALCAN and HPA databases was used to analyze the differences in mRNA and protein levels of CERCAM expression in HNSCC. The Timer database was also applied to analyze the correlation between CERCAM in HNSCC and immune infiltration. TCGA-HNSCC database was applied to analyze the correlation between CERCAM expression levels and clinicopathological features, and its diagnostic and prognostic value in HNSCC was also assessed. The cBioPortal and MethSurv databases were then applied to analyze the genetic variation and methylation status of CERCAM. In vitro cellular assays were performed to provide evidence that CERCAM promotes malignant biological behavior of tumors and promotes macrophage M2 polarization in tumors. Finally, underlying pathophysiological mechanisms of CERCAM involvement in the development of HNSCC were predicted using a bioinformatics approach. RESULTS: CERCAM is significantly overexpressed in HNSCC and correlates with poor prognostic levels and has good performance in predicting survival status in HNSCC patients. Cox regression analysis indicates that CERCAM expression levels are independent risk factors for predicting OS, DSS, and PFI. CERCAM promotes tumor malignant biological behavior and promotes macrophage M2 polarization immune infiltration in HNSCC. In addition, CERCAM promotes tumor cell adhesion in head and neck squamous carcinoma and promotes tumor progression through several oncogenic signaling pathways. CONCLUSION: CERCAM may serve as a new diagnostic and prognostic biomarker in HNSCC and is a promising therapeutic target for HNSCC.

Dramatic decline of observed atmospheric CO2 and CH4 during the COVID-19 lockdown over the Yangtze River Delta of China.

The temporal variation of greenhouse gas concentrations in China during the COVID-19 lockdown in China is analyzed in this work using high resolution measurements of near surface △CO2, △CH4 and △CO concentrations above the background conditions at Lin'an station (LAN), a regional background station in the Yangtze River Delta region. During the pre-lockdown observational period (IOP-1), both △CO2 and △CH4 exhibited a significant increasing trend relative to the 2011-2019 climatological mean. The reduction of △CO2, △CH4 and △CO during the lockdown observational period (IOP-2) (which also coincided with the Chinese New Year Holiday) reached up to 15.0 ppm, 14.2 ppb and 146.8 ppb, respectively, and a reduction of △CO2/△CO probably due to a dramatic reduction from industrial emissions. △CO2, △CH4 and △CO were observed to keep declining during the post-lockdown easing phase (IOP-3), which is the synthetic result of lower than normal CO2 emissions from rural regions around LAN coupled with strong uptake of the terrestrial ecosystem. Interestingly, the trend reversed to gradual increase for all species during the later easing phase (IOP-4), with △CO2/△CO constantly increasing from IOP-2 to IOP-3 and finally IOP-4, consistent with recovery in industrial emissions associated with the staged resumption of economic activity. On average, △CO2 declined sharply throughout the days during IOP-2 but increased gradually throughout the days during IOP-4. The findings showcase the significant role of emission reduction in accounting for the dramatic changes in measured atmospheric △CO2 and △CH4 associated with the COVID-19 lockdown and recovery.

Different human papillomavirus types share early natural history transitions in immunocompetent women.

Necessary stages of cervical carcinogenesis include acquisition of a carcinogenic human papillomavirus (HPV) type, persistence associated with the development of precancerous lesions, and invasion. Using prospective data from immunocompetent women in the Guanacaste HPV Natural History Study (NHS), the ASCUS-LSIL Triage Study (ALTS) and the Costa Rica HPV Vaccine Trial (CVT), we compared the early natural history of HPV types to inform transition probabilities for health decision models. We excluded women with evidence of high-grade cervical abnormalities at any point during follow-up and restricted the analysis to incident infections in all women and prevalent infections in young women (aged <30 years). We used survival approaches accounting for interval-censoring to estimate the time to clearance distribution for 20 529 HPV infections (64% were incident and 51% were carcinogenic). Time to clearance was similar across HPV types and risk classes (HPV16, HPV18/45, HPV31/33/35/52/58, HPV 39/51/56/59 and noncarcinogenic HPV types); and by age group (18-29, 30-44 and 45-54 years), among carcinogenic and noncarcinogenic infections. Similar time to clearance across HPV types suggests that relative prevalence can predict relative incidence. We confirmed that there was a uniform linear association between incident and prevalent infections for all HPV types within each study cohort. In the absence of progression to precancer, we observed similar time to clearance for incident infections across HPV types and risk classes. A singular clearance function for incident HPV infections has important implications for the refinement of microsimulation models used to evaluate the cost-effectiveness of novel prevention technologies.

Narrative Scientific Data Visualization in an Immersive Environment.

MOTIVATION: Narrative visualization for scientific data explorations can help users better understand the domain knowledge, because narrative visualizations often present a sequence of facts and observations linked together by a unifying theme or argument. Narrative visualization in immersive environments can provide users with an intuitive experience to interactively explore the scientific data, because immersive environments provide a brand new strategy for interactive scientific data visualization and exploration. However, it is challenging to develop narrative scientific visualization in immersive environments. In this paper, we propose an immersive narrative visualization tool to create and customize scientific data explorations for ordinary users with little knowledge about programming on scientific visualization, They are allowed to define POIs (point of interests) conveniently by the handler of an immersive device. RESULTS: Automatic exploration animations with narrative annotations can be generated by the gradual transitions between consecutive POI pairs. Besides, interactive slicing can be also controlled by device handler. Evaluations including user study and case study are designed and conducted to show the usability and effectiveness of the proposed tool. AVAILABILITY: Related information can be accessed at: https://dabigtou.github.io/richenliu/.

Contribution of Etiologic Cofactors to CIN3+ Risk Among Women With Human Papillomavirus-Positive Screening Test Results.

OBJECTIVE: The US screening and management guidelines for cervical cancer are based on the absolute risk of precancer estimated from large clinical cohorts and trials. Given the widespread transition toward screening with human papillomavirus (HPV) testing, it is important to assess which additional factors to include in clinical risk assessment to optimize management of HPV-infected women. MATERIALS AND METHODS: We analyzed data from HPV-infected women, ages 30-65 years, in the National Cancer Institute-Kaiser Permanente Northern California Persistence and Progression study. We estimated the influence of HPV risk group, cytology result, and selected cofactors on immediate risk of cervical intraepithelial neoplasia grade 3 or higher (CIN 3+) among 16,094 HPV-positive women. Cofactors considered included, age, race/ethnicity, income, smoking, and hormonal contraceptive use. RESULTS: Human papillomavirus risk group and cytology test result were strongly correlated with CIN 3+ risk. After considering cytology and HPV risk group, other cofactors (age, race/ethnicity, income, smoking, and hormonal contraceptive use) had minimal impact on CIN 3+ risk and did not change recommended management based on accepted risk thresholds. We had insufficient data to assess the impact of long-duration heavy smoking, parity, history of sexually transmitted infection, or immunosuppression. CONCLUSIONS: In our study at the Kaiser Permanente Northern California, the risk of CIN 3+ was determined mainly by HPV risk group and cytology results, with other cofactors having limited impact in adjusted analyses. This supports the use of HPV and cytology results in risk-based management guidelines.

Comparison of Properties of Poly(Lactic Acid) Composites Prepared from Different Components of Corn Straw Fiber.

In recent years, under the pressure of resource shortage and white pollution, the development and utilization of biodegradable wood-plastic composites (WPC) has become one of the hot spots for scholars' research. Here, corn straw fiber (CSF) was chosen to reinforce a poly(lactic acid) (PLA) matrix with a mass ratio of 3:7, and the CSF/PLA composites were obtained by melt mixing. The results showed that the mechanical properties of the corn straw fiber core (CSFC) and corn straw fiber skin (CSFS) loaded PLA composites were stronger than those of the CSFS/PLA composites when the particle size of CSF was low. The tensile strength and bending strength of CSFS/CSFC/PLA are 54.08 MPa and 87.24 MPa, respectively, and the elongation at break is 4.60%. After soaking for 8 hours, the water absorption of CSF/PLA composite reached saturation. When the particle size of CSF is above 80 mesh, the saturated water absorption of the material is kept below 7%, and CSF/PLA composite has good hydrophobicity, which is mainly related to the interfacial compatibility between PLA and CSF. By observing the microstructure of the cross section of the CSF/PLA composite, the research found that the smaller the particle size of CSF, the smoother the cross section of the composite and the more unified the dispersion of CSF in PLA. Therefore, exploring the composites formed by different components of CSF and PLA can not only expand the application range of PLA, but also enhance the application value of CSF in the field of composites.

Risk of cervical precancer and cancer among uninsured and underserved women from 2009 to 2017.

BACKGROUND: New guidelines for managing cervical precancer among women in the United States use risk directly to guide clinical actions for individuals who are being screened. These risk-based management guidelines have previously only been based on risks from a large integrated healthcare system. We present here data representative of women of low income without continuous insurance coverage to inform the 2019 guidelines and ensure applicability. OBJECTIVE: We examined the risks of high-grade precancer after human papillomavirus and cytology tests in underserved women and assessed the applicability of the 2019 guidelines to this population. STUDY DESIGN: We examined cervical cancer screening and follow-up data among 363,546 women enrolled in the Centers for Disease Control and Prevention's National Breast and Cervical Cancer Early Detection Program from 2009 to 2017. We estimated the immediate (prevalent) risks of cervical intraepithelial lesion grade 3 or cancer by using prevalence-incidence mixture models. Risks were estimated for each combination of human papillomavirus and cytology result and were stratified by screening history. We compared these risks with published estimates used in new risk-based management guidelines. RESULTS: Women who were up-to-date with their screening, defined as being screened with cytology within the past 5 years, had immediate risks of cervical intraepithelial neoplasia grade 3 or higher similar to that of women at Kaiser Permanente Northern California, whose data were used to develop the management guidelines. However, women in the Centers for Disease Control and Prevention's National Breast and Cervical Cancer Early Detection Program had greater immediate risks if they were never screened or not up-to-date with their screening. CONCLUSION: New cervical risk-based management guidelines are applicable for underinsured and uninsured women with a low income in the United States who are up-to-date with their screening. The increased risk observed here among women who received human papillomavirus-positive, high-grade cytology results, who were never screened, or who were not up-to-date with their cervical cancer screening, led to a recommendation in the management guidelines for immediate treatment among these women.

Clinicopathological and prognostic analyses of 86 resected pulmonary lymphoepithelioma-like carcinomas.

BACKGROUND: Pulmonary lymphoepithelioma-like carcinoma (LELC) is a rare subtype of primary lung cancer. The present study aims at investigating clinicopathological features and prognostic characteristics of the resected pulmonary LELC. METHODS: Patients with resected pulmonary LELC were identified in our hospital from December 2008 to December 2018. Data of these patients were retrospectively reviewed, clinicopathological features and prognostic characteristics were analyzed subsequently. RESULTS: In total, 86 patients were enrolled in the study, including 39 (45.3%) males and 47 (54.7%) females. Most of the serum tumor markers were normal. Immunohistochemical staining result showed frequent differentiation traits of epithelial tissue such. Positive PD-L1 (15 of 19, 78.9%) and PD-1 (13 of 17, 76.5%) were also common, but cancer-related genetic mutation was scarce (1 of 47, 2.1%). Survival analyses demonstrated that the N stage (p = .011) and extent of resection (p = .023) were identified as independent predictive factors for overall survival. CONCLUSIONS: Pulmonary LELC is a distinctive subtype of lung cancer with several exclusive traits, such as the trend to happen among nonsmoking young people, epithelial origin of tumor differentiation, frequent expression of the immune checkpoint, and scarce presence of driver mutation. In addition, pulmonary LELC was apt to get a favorable outcome, especially in cases diagnosed and treated in the early stage.

Association of HPV35 with cervical carcinogenesis among women of African ancestry: Evidence of viral-host interaction with implications for disease intervention.

HPV35 has been found in only ∼2% of invasive cervical cancers (ICC) worldwide but up to 10% in Sub-Saharan Africa, warranting further investigation and consideration of impact on preventive strategies. We studied HPV35 and ethnicity, in relation to the known steps in cervical carcinogenesis, using multiple large epidemiologic studies in the U.S. and internationally. Combining five U.S. studies, we measured HPV35 positivity and, in Northern California, observed HPV35 type-specific population prevalence and estimated 5-year risk of developing precancer when HPV35-positive. HPV35 genetic variation was examined for differences in carcinogenicity in 1053 HPV35+ cervical specimens from a U.S. cohort and an international collection. African-American women had more HPV35 (12.1% vs 5.1%, P < .001) and more HPV35-associated precancers (7.4% vs 2.1%, P < .001) compared to other ethnicities. Precancer risks after HPV35 infection did not vary by ethnicity (global P = .52). The HPV35 A2 sublineage showed an increased association with precancer/cancer in African-Americans (OR = 5.6 vs A1, 95% CI = 1.3-24.8) and A2 was more prevalent among ICC in Africa than other world regions (41.9% vs 10.4%, P < .01). Our analyses support a strong link between HPV35 and cervical carcinogenesis in women of African ancestry. Current HPV vaccines cover the majority of cervical precancer/cancer across all ethnic groups; additional analyses are required to determine whether the addition of HPV35 to the already highly effective nine-valent HPV vaccine would provide better protection for women in Africa or of African ancestry.

N-glycosylation of Siglec-15 decreases its lysosome-dependent degradation and promotes its transportation to the cell membrane.

Siglec-15 was recently reported to be an immunosuppressive molecule that is expressed by tumor-associated macrophages and upregulated in some solid tumors. Targeting Siglec-15 is a potential strategy for normalization cancer immunotherapy. Here, we identified the important post-translational modification, N-glycosylation of Siglec-15, which is regulated by glucose uptake. Using a series of glycosidase and glycosylation inhibitors, we demonstrated that Siglec-15 was completely N-glycosylated in vitro and in vivo. The precise glycosylation site was determined. N-glycosylation stabilized Siglec-15 by decreasing its lysosome-dependent degradation. Siglec-15 subcellular distribution detected by immunofluorescence indicated that N-glycosylation promoted Siglec-15 transportation to the cell membrane. The collective observations indicate that targeting the N-glycosylation of Siglec-15 may be an effective supplement to immunotherapy.

Predictive and prognostic values of preoperative platelet parameters in patients with gynecological tumors.

BACKGROUND: Platelets play a role in tumor cell growth, metastasis, and angiogenesis, and the present study aimed to evaluate diagnostic and prognostic values of platelet parameters in patients with gynecological tumors. METHODS: A total of 1062 women were included. Differences of platelet parameters (platelet count [PLT], plateletcrit [PCT], mean platelet volume [MPV], platelet-large cell rate [P-LCR], and platelet distribution width [PDW]) between different categories were analyzed by nonparametric test. The optimal cutoff value was calculated with receiver operating characteristic analysis. Overall survivals were analyzed with Kaplan-Meier method and log-rank tests for univariate analysis. RESULTS: Platelet count and PCT were significantly increased, and MPV and P-LCR were significantly reduced in malign and benign gynecological tumor groups compared with the controls (P < .001); PDW had no significant differences. There were no significant differences in PLT, PCT, MPV, P-LCR, and PDW between different tumor locations and pathologic types. The optimal cutoff values of PLT, PCT, MPV and P-LCR were 274, 0.26, 10.08, and 24.8 (AUC: 0.661, 0.643, 0.593, 0.562), and PCT had preferable sensibility and specificity (50.84% and 70.42%) in predicting the presence of gynecological tumors. According to survival analysis, increased PLT (≥274 × 109 /L) and PCT (≥0.26), and induced MPV (<10.08 fL) and P-LCR (<24.8%) were associated with shorter overall survival. CONCLUSIONS: Platelet count, PCT, MPV, and P-LCR can be used as preferable auxiliary parameters for predicting the presence of gynecological tumors. Increased PLT and PCT, or decreased MPV and P-LCR indicated a heavier tumor burden and shorter overall survival.

2019 ASCCP Risk-Based Management Consensus Guidelines: Methods for Risk Estimation, Recommended Management, and Validation.

OBJECTIVE: To manage cervical screening abnormalities, the 2019 ASCCP management consensus guidelines will recommend clinical action on the basis of risk of cervical precancer and cancer. This article details the methods used to estimate risk, to determine the risk-based management, and to validate that the risk-based recommendations are of general use in different settings. METHODS: Based on 1.5 million patients undergoing triennial cervical screening by cotesting at the Kaiser Permanente Northern California from 2003 to 2017, we estimated risk profiles for different clinical scenarios and combinations of past and current human papillomavirus and cytology test results. We validated the recommended management by comparing with the estimated risks in several external data sources. RESULTS: Risk and management tables are presented separately by Egemen et al. and Demarco et al. Risk-based management derived from the Kaiser Permanente Northern California largely agreed with the management implied from the estimated risks of the other data sources. CONCLUSIONS: The new risk-based guidelines present management of abnormal cervical screening results. By describing the steps used to develop these guidelines, the methods presented in this article can provide a basis for future extensions of the risk-based guidelines.

Risk Estimates Supporting the 2019 ASCCP Risk-Based Management Consensus Guidelines.

The 2019 American Society for Colposcopy and Cervical Pathology Risk-Based Management Consensus Guidelines for the management of cervical cancer screening abnormalities recommend 1 of 6 clinical actions (treatment, optional treatment or colposcopy/biopsy, colposcopy/biopsy, 1-year surveillance, 3-year surveillance, 5-year return to regular screening) based on the risk of cervical intraepithelial neoplasia grade 3, adenocarcinoma in situ, or cancer (CIN 3+) for the many different combinations of current and recent past screening results. This article supports the main guidelines presentation by presenting and explaining the risk estimates that supported the guidelines. METHODS: From 2003 to 2017 at Kaiser Permanente Northern California (KPNC), 1.5 million individuals aged 25 to 65 years were screened with human papillomavirus (HPV) and cytology cotesting scheduled every 3 years. We estimated immediate and 5-year risks of CIN 3+ for combinations of current test results paired with history of screening test and colposcopy/biopsy results. RESULTS: Risk tables are presented for different clinical scenarios. Examples of important results are highlighted; for example, the risk posed by most current abnormalities is greatly reduced if the prior screening round was HPV-negative. The immediate and 5-year risks of CIN 3+ used to decide clinical management are shown. CONCLUSIONS: The new risk-based guidelines present recommendations for the management of abnormal screening test and histology results; the key risk estimates supporting guidelines are presented in this article. Comprehensive risk estimates are freely available online at https://CervixCa.nlm.nih.gov/RiskTables.

A Study of Partial Human Papillomavirus Genotyping in Support of the 2019 ASCCP Risk-Based Management Consensus Guidelines.

INTRODUCTION: The 2019 ASCCP Risk-Based Management Consensus Guidelines include recommendations for partial human papillomavirus (HPV) genotyping in management of abnormal cervical cancer screening results. The guidelines are based on matching estimates of cervical intraepithelial neoplasia (CIN) 3+ risk to consensus clinical action thresholds. In support of the guidelines, this analysis addresses the risks predicted by individual identification of HPV 16 and HPV 18. METHODS: Risk estimates were drawn from a subset of women in the Kaiser Permanente Northern California screening program, whose residual cervical specimens were HPV typed as part of the HPV Persistence and Progression study. We calculated risk of CIN 3+ to assess how identification of HPV 16, HPV 18, or 12 other "high-risk" HPV types would influence recommended clinical management of new abnormal screening results, taking into account current cytologic results and recent screening history. Immediate and/or 5-year risks of CIN 3+ were matched to clinical actions identified in the guidelines. RESULTS: Identification of HPV 16 at the first visit including HPV testing elevated immediate risk of diagnosing CIN 3+ sufficiently to mandate colposcopic referral even when cytology was Negative for Intraepithelial Lesions or Malignancy and to support a preference for treatment of cytologic high-grade squamous intraepithelial lesion. HPV 18 less clearly elevated CIN 3+ risk. CONCLUSIONS: Identification of HPV 16 clearly mandated consideration in clinical management of new abnormal screening results. HPV 18 positivity must be considered as a special situation because of established disproportionate risk of invasive cancer. More detailed genotyping and use beyond initial management will be considered in guideline updates.

Characterization of the molecular mechanism of the autophagy-related Atg8-Atg3 protein interaction in Toxoplasma gondii.

Toxoplasmosis is caused by an obligate intracellular parasite, the protozoan Toxoplasma gondii Discovery of novel drugs against T. gondii infection could circumvent the toxicity of existing drugs and T. gondii resistance to current treatments. The autophagy-related protein 8 (Atg8)-Atg3 interaction in T. gondii is a promising drug target because of its importance for regulating Atg8 lipidation. We reported previously that TgAtg8 and TgAtg3 interact directly. Here we validated that substitutions of conserved residues of TgAtg8 interacting with the Atg8 family-interacting motif (AIM) in Atg3 disrupt the TgAtg8-TgAtg3 interaction and reduce TgAtg8 lipidation and autophagosome formation. These findings were consistent with results reported previously for Plasmodium Atg8, suggesting functional conservation of Atg8 in Toxoplasma and Plasmodium. Moreover, using peptide and AlphaScreen assays, we identified the AIM sequence in TgAtg3 that binds TgAtg8. We determined that the core TgAtg3 AIM contains a Phe239-Ala240-Asp241-Ile242 (239FADI242) signature distinct from the 105WLLP108 signature in the AIM of Plasmodium Atg3. Furthermore, an alanine-scanning assay revealed that the TgAtg8-TgAtg3 interaction in T. gondii also depends strongly on several residues surrounding the core TgAtg3 AIM, such as Asn238, Asp243, and Cys244 These results indicate that distinct AIMs in Atg3 contribute to differences between Toxoplasma and Plasmodium Atg8-Atg3 interactions. By elucidating critical residues involved in the TgAtg8-TgAtg3 interaction, our work paves the way for the discovery of potential anti-toxoplasmosis drugs. The quantitative and straightforward AlphaScreen assay developed here may enable high-throughput screening for small molecules disrupting the TgAtg8-TgAtg3 interaction.

Classification of Power Facility Point Clouds from Unmanned Aerial Vehicles Based on Adaboost and Topological Constraints.

Machine learning algorithms can be well suited to LiDAR point cloud classification, but when they are applied to the point cloud classification of power facilities, many problems such as a large number of computational features and low computational efficiency can be encountered. To solve these problems, this paper proposes the use of the Adaboost algorithm and different topological constraints. For different objects, the top five features with the best discrimination are selected and combined into a strong classifier by the Adaboost algorithm, where coarse classification is performed. For power transmission lines, the optimum scales are selected automatically, and the coarse classification results are refined. For power towers, it is difficult to distinguish the tower from vegetation points by only using spatial features due to the similarity of their proposed key features. Therefore, the topological relationship between the power line and power tower is introduced to distinguish the power tower from vegetation points. The experimental results show that the classification of power transmission lines and power towers by our method can achieve the accuracy of manual classification results and even be more efficient.

Trend-Residual Dual Modeling for Detection of Outliers in Low-Cost GPS Trajectories.

Low-cost GPS (receiver) has become a ubiquitous and integral part of our daily life. Despite noticeable advantages such as being cheap, small, light, and easy to use, its limited positioning accuracy devalues and hampers its wide applications for reliable mapping and analysis. Two conventional techniques to remove outliers in a GPS trajectory are thresholding and Kalman-based methods, which are difficult in selecting appropriate thresholds and modeling the trajectories. Moreover, they are insensitive to medium and small outliers, especially for low-sample-rate trajectories. This paper proposes a model-based GPS trajectory cleaner. Rather than examining speed and acceleration or assuming a pre-determined trajectory model, we first use cubic smooth spline to adaptively model the trend of the trajectory. The residuals, i.e., the differences between the trend and GPS measurements, are then further modeled by time series method. Outliers are detected by scoring the residuals at every GPS trajectory point. Comparing to the conventional procedures, the trend-residual dual modeling approach has the following features: (a) it is able to model trajectories and detect outliers adaptively; (b) only one critical value for outlier scores needs to be set; (c) it is able to robustly detect unapparent outliers; and (d) it is effective in cleaning outliers for GPS trajectories with low sample rates. Tests are carried out on three real-world GPS trajectories datasets. The evaluation demonstrates an average of 9.27 times better performance in outlier detection for GPS trajectories than thresholding and Kalman-based techniques.