Research progress on the regulation of bone marrow stem cells by noncoding RNAs in adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity in young women, but its pathogenesis remains unclear. The primary pathogenic factors contributing to its development include genetics, abnormal bone metabolism, and endocrine factors. Bone marrow stem cells (BMSCs) play a crucial role in the pathogenesis of AIS by regulating its occurrence and progression. Noncoding RNAs (ncRNAs) are also involved in the pathogenesis of AIS, and their role in regulating BMSCs in patients with AIS requires further evaluation. In this review, we discuss the relevant literature regarding the osteogenic, chondrogenic, and lipogenic differentiation of BMSCs. The corresponding mechanisms of ncRNA-mediated BMSC regulation in patients with AIS, recent advancements in AIS and ncRNA research, and the importance of ncRNA translation profiling and multiomics are highlighted.

BMP6 participates in the pathogenesis of adolescent idiopathic scoliosis by regulating osteopenia.

Adolescent idiopathic scoliosis (AIS) is a complex disease characterized by three-dimensional structural deformities of the spine. Its pathogenesis is associated with osteopenia. Bone-marrow-derived mesenchymal stem cells (BMSCs) play an important role in bone metabolism. We detected 1919 differentially expressed mRNAs and 744 differentially expressed lncRNAs in BMSCs from seven patients with AIS and five patients without AIS via high-throughput sequencing. Multiple analyses identified bone morphogenetic protein-6 (BMP6) as a hub gene that regulates the abnormal osteogenic differentiation of BMSCs in AIS. BMP6 expression was found to be decreased in AIS and its knockdown in human BMSCs significantly altered the degree of osteogenic differentiation. Additionally, CAP1-217 has been shown to be a potential upstream regulatory molecule of BMP6. We showed that CAP1-217 knockdown downregulated the expression of BMP6 and the osteogenic differentiation of BMSCs. Simultaneously, knockout of BMP6 in zebrafish embryos significantly increased the deformity rate. The findings of this study suggest that BMP6 is a key gene that regulates the abnormal osteogenic differentiation of BMSCs in AIS via the CAP1-217/BMP6/RUNX2 axis.

Malignant transformation of rectal endometriosis: Preoperative diagnosis by endorectal ultrasound guided biopsy.

The prevalence of malignant transformation of endometriotic lesions is estimated between 0.3% and 1%. Malignant transformations of endometriosis occur in the colorectum is rarer, accounting for 0.25%. Because the malignant transformation of colorectal endometriosis rarely involves mucosa, it is difficult to obtain abnormal tissue by routine endoscopic biopsy. In this case, we evaluated a patient with a rectal mass by endorectal ultrasound (ERUS) and performed endorectal ultrasound-guided biopsy (EGB). Malignant transformations of endometriosis were confirmed by histological result. For patients with rectal tumors but with negative findings on colonoscopy and biopsy, ERUS and EGB contribute to preoperative diagnosis.

Association between weight change and breast cancer prognosis.

PURPOSE: Results of the associations between weight change after breast cancer diagnosis and prognosis were inconsistent. The modification effects of menopausal status and endocrine therapy on the associations remain poorly understood. METHODS: A total of 2016 breast cancer patients were recruited between October 2008 and January 2018 and followed up until December 31, 2019 in Guangzhou. Multivariate Cox models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for progression-free survival (PFS) in association with weight change after diagnosis. RESULTS: Weight loss at 2 years (HR = 1.34, 95% CI 0.87-2.06) or more than 2 years (HR = 1.95, 95% CI 1.22-3.10) after diagnosis increased risk of breast cancer progression. The adverse effect of weight loss was significantly more pronounced in post-menopausal than pre-menopausal women, particularly for weight loss at 2 years after diagnosis, with the HRs and 95% CIs of 2.41 (1.25-4.63) and 0.90 (0.49-1.64), respectively. Weight gain tended to reduce the risk of disease progression among patients with endocrine therapy but not for those with non-endocrine therapy; the significant interaction between weight gain at 2 years after diagnosis and endocrine therapy was observed (Pinteraction = 0.042). CONCLUSION: Our finding suggested that weight loss was detrimental to breast cancer prognosis, particularly for post-menopausal women, while weight gain may be a potential beneficial indicator for the patients with endocrine therapy but not for those with non-endocrine therapy.

The role of endocrine hormones in the pathogenesis of adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity characterized by changes in the three-dimensional structure of the spine. It usually initiates during puberty, the peak period of human growth when the secretion of numerous hormones is changing, and it is more common in females than in males. Accumulating evidence shows that the abnormal levels of many hormones including estrogen, melatonin, growth hormone, leptin, adiponectin and ghrelin, may be related to the occurrence and development of AIS. The purpose of this review is to provide a summary and critique of the research published on each hormone over the past 20 years, and to highlight areas for future study. It is hoped that the presentation will help provide a better understanding of the role of endocrine hormones in the pathogenesis of AIS.

Discovery of novel paeonol-based derivatives against skin inflammation in vitro and in vivo.

T-LAK-cell-originated protein kinase (TOPK), a novel member of the mitogen-activated protein kinase family, is considered an effective therapeutic target for skin inflammation. In this study, a series (A - D) of paeonol derivatives was designed and synthesised using a fragment growing approach, and their anti-inflammatory activities against lipopolysaccharide (LPS)-induced nitric oxide production in RAW264.7 cells were tested. Among them, compound B12 yielded the best results (IC50 = 2.14 µM) with low toxicity (IC50 > 50 µM). Preliminary mechanistic studies indicated that this compound could inhibit the TOPK-p38/JNK signalling pathway and phosphorylate downstream related proteins. A murine psoriasis-like skin inflammation model was used to determine its therapeutic effect.

Collision Localization and Classification on the End-Effector of a Cable-Driven Manipulator Applied to EV Auto-Charging Based on DCNN-SVM.

With the increasing popularity of electric vehicles, cable-driven serial manipulators have been applied in auto-charging processes for electric vehicles. To ensure the safety of the physical vehicle-robot interaction in this scenario, this paper presents a model-independent collision localization and classification method for cable-driven serial manipulators. First, based on the dynamic characteristics of the manipulator, data sets of terminal collision are constructed. In contrast to utilizing signals based on torque sensors, our data sets comprise the vibration signals of a specific compensator. Then, the collected data sets are applied to construct and train our collision localization and classification model, which consists of a double-layer CNN and an SVM. Compared to previous works, the proposed method can extract features without manual intervention and can deal with collision when the contact surface is irregular. Furthermore, the proposed method is able to generate the location and classification of the collision at the same time. The simulated experiment results show the validity of the proposed collision localization and classification method, with promising prediction accuracy.

Research on Fast Recognition and Localization of an Electric Vehicle Charging Port Based on a Cluster Template Matching Algorithm.

With the gradual maturity of driverless and automatic parking technologies, electric vehicle charging has been gradually developing in the direction of automation. However, the pose calculation of the charging port (CP) is an important part of realizing automatic charging, and it represents a problem that needs to be solved urgently. To address this problem, this paper proposes a set of efficient and accurate methods for determining the pose of an electric vehicle CP, which mainly includes the search and aiming phases. In the search phase, the feature circle algorithm is used to fit the ellipse information to obtain the pixel coordinates of the feature point. In the aiming phase, contour matching and logarithmic evaluation indicators are used in the cluster template matching algorithm (CTMA) proposed in this paper to obtain the matching position. Based on the image deformation rate and zoom rates, a matching template is established to realize the fast and accurate matching of textureless circular features and complex light fields. The EPnP algorithm is employed to obtain the pose information, and an AUBO-i5 robot is used to complete the charging gun insertion. The results show that the average CP positioning errors (x, y, z, Rx, Ry, and Rz) of the proposed algorithm are 0.65 mm, 0.84 mm, 1.24 mm, 1.11 degrees, 0.95 degrees, and 0.55 degrees. Further, the efficiency of the positioning method is improved by 510.4% and the comprehensive plug-in success rate is 95%. Therefore, the proposed CTMA in this paper can efficiently and accurately identify the CP while meeting the actual plug-in requirements.

Time-varying effects of FOXA1 on breast cancer prognosis.

PURPOSE: Results of previous studies on the associations between Forkhead box A1 (FOXA1) expression in breast cancer tissues and the prognosis varied depending on the follow-up durations. The present study would investigate whether there is a time-varying effect of FOXA1 in breast cancer tissues on the prognosis. METHODS: FOXA1 expressions were evaluated in 1041 primary invasive breast tumors with tissue microarrays by immunohistochemistry. Cox models with restricted cubic splines and Kaplan-Meier survival analysis were used to examine the associations between FOXA1 and the prognosis. Flexible parametric models were applied to explore the time-varying effect of FOXA1. RESULTS: Overall, the association between FOXA1 expression and the prognosis was not significant but varied on the time of follow-up. Compared to FOXA1 ≤ 270 of H-score, the hazard ratios (HRs) of death for those with 271-285 of FOXA1 expression increased from 0.35 (95% CI 0.14-0.86) at 6 months after diagnosis to 2.88 (95% CI 1.35-6.15) at 120 months with a crossover at around 36 months. Similar patterns were also observed for FOXA1 > 285 of H-score and for progression free survival (PFS). Moreover, when allowed both FOXA1 and estrogen receptor (ER) to change over time in the model (considering that ER had a similar time-varying effect), these time-varying effects remained for FOXA1 on both overall survival (OS) (P < 0.01) and PFS (P = 0.01) but were attenuated for ER (P = 0.13 for OS). CONCLUSIONS: This study revealed an independent time-varying effect of FOXA1 on breast cancer prognosis, which would provide an insight into the roles of FOXA1 as a marker of breast cancer prognosis and may help optimize the medication strategies.

New method and electrophysiological characteristics of LA posterior wall isolation in persistent atrial fibrillation.

BACKGROUND: Left atrial posterior wall isolation (PWI) is commonly used with persistent atrial fibrillation (AF) ablation. However, potentials are often still recorded in the posterior wall after pulmonary vein isolation (PVI), roof linear ablation, and bottom linear ablation in clinical practice. We aimed to explore the methodological approach and electrophysiological characteristics of PWI. METHODS: A total of 36 patients who attended our center with long-standing persistent AF were retrospectively analyzed. After routine PVI and roof and bottom linear ablation, complete PWI was confirmed in sinus rhythm by voltage mapping and high-output pacing. Otherwise, activation mapping and voltage mapping were used to guide ablation on the line or inside the posterior wall until bidirectional block was achieved. RESULTS: The first-pass success rate of PWI was 39%. In the remaining 61% of patients with posterior wall electrograms, activation mapping in sinus rhythm showed that the earliest activation point was not on the ablation line but in a relatively dispersed focal area, possibly related to epicardial muscular sleeve insertion. Voltage mapping revealed a focal high-voltage area in the posterior wall matching the relatively dispersed earliest activation site, in which an average of five points of ablation achieved complete PWI without serious esophageal injury. The middle zone contained 80% of the additional posterior wall ablation points. CONCLUSIONS: PWI was performed safely and effectively with an average of five additional ablation points in the posterior wall in 61% of patients under the guidance of voltage mapping.

Incidence of permanent pacemaker implantation after valve replacement surgery : Cardiac structure and function at 1-year follow-up.

BACKGROUND: Our study aimed to explore the incidence and risk factors of permanent pacemaker implantation (PPI) after valve replacement surgery (VR). The influence of long-term pacemaker dependency on cardiac structure and function at the 1­year follow-up was also assessed. METHODS: The demographic and surgical data of all consecutive patients who underwent VR between 2013 and 2016 were collected. Univariate and multivariate analyses were performed to identify variables independently associated with PPI after VR. A 1­year follow-up was undertaken of patients who underwent dual-chambers pacemaker after VR because of complete atrioventricular block (AVB). Long-term pacemaker dependency and recovery of cardiac structure and function were evaluated. RESULTS: There were 5320 consecutive patients with VR. The incidence of postoperative PPI was 2.42%. Multivariate analysis indicated that among the 62 patients who underwent PPI due to AVB and sick sinus syndrome, isolated aortic valve replacement (AVR; OR: 2.24, p < 0.05), VR combined with ventricular septal defect (VSD) repair (OR: 6.78, p < 0.05), and VR with aortic root and arch surgery (OR: 4.14, p < 0.05) were independent predictors of PPI after surgery. In total, 89.6% (43/48) of the survivors showed pacemaker dependency. Of these 43 patients, 24 had enlarged left heart before VR. Compared with preoperative values, the left atrial and left ventricular end-diastolic diameter post-PPI decreased significantly, while left ventricular ejection fraction was not significantly different. CONCLUSION: Isolated AVR, VR concomitant with VSD repair, and VR with aortic root and arch surgery are independent predictors of PPI after VR. The majority of patients do not recover from AVB disorders and there is no significant negative effect on recovery of cardiac structure and function.

Analysis of transcription factors in accessible open chromatin in the 18-trisomy syndrome based on single cell ATAC sequencing technique.

Trisomy 18 syndrome is one of the most common autosomal aneuploidy disorders. Little is known about the genetic regulation leading to the clinical phenotypes associated with the occurrence and development of trisomy 18 syndrome disorders (e.g., mental retardation, cardiac and renal abnormalities). To explore the regulatory factors that influence the phenotypes of the disease, this study used single-cell ATAC sequencing to analyze transcription factors in the accessibility chromatin regions of the single-nucleus cells of the cord blood from 18-trisomy syndrome and control subjects. A single-cell library constructed by capturing 11,611 cells identified seven major immune cell populations, and the results of cell number statistics suggested the presence of abnormalities in the immune system of 18-trisomy syndrome patients. Fourteen transcription factors (P<0.05, |FC|>1.2) were identified by analyzed accessibility chromatin regions. The relative expression levels of four of these transcription factors (TEAD1, TEAD2, TEAD4, Twist2) were confirmed using real-time quantitative fluorescence PCR. In conjunction with information from the literature, this study suggests that these four transcription factors may be associated with abnormalities in cardiac and skeletal development in patients with the 18-trisomy syndrome, thereby providing candidate molecules for mechanistic studies on the occurrence and development of the 18-trisomy syndrome phenotypes.

circRNA-miRNA-mRNA regulatory network in human lung cancer: an update.

Circular RNAs, as hopeful diagnosis markers and therapeutic molecules, have been studied, probed and applied into several diseases, such as cardiovascular diseases, systemic lupus erythematosus, leukemia, pulmonary tuberculosis, and cancer especially. Recently, mounting evidence has supported that circRNAs play a key role in the tumorigenesis, progress, invasion and metastasis in lung cancer. Its special structure-3'-5' covalent loop-allow it to execute several special functions in both normal eukaryotic cells and cancer cells. Our review summaries the latest studies on characteristics and biogenesis of circRNAs, and highlight the regulatory functions about miRNA sponge of lung-cancer-related circRNAs. In addition, the interaction of the circRNA-miRNA-mRNA regulatory network will also be elaborated in detail in this review. Therefore, this review can provide a new idea or strategy for further development and application in clinical setting in terms of early-diagnosis and better treatment.

Serum-Soluble ST2 Is a Novel Biomarker for Evaluating Left Atrial Low-Voltage Zone in Paroxysmal Atrial Fibrillation.

BACKGROUND Paroxysmal atrial fibrillation (pAF) recurrence after radiofrequency catheter ablation (RFCA) is linked to low-voltage zone (LVZ). This study explored whether serum soluble ST2 (sST2) levels can predict the size of LVZs in patients with pAF. MATERIAL AND METHODS A total of 177 patients with pAF treated with RFCA were consecutively enrolled in this study. One hundred twenty-five patients (70.6%) with <20% LVZ were assigned to Group A, and 52 patients (29.4%) with a LVZ >20% were assigned to Group B. Levels of soluble ST2 (sST2), growth and differentiation factor (GDF-15) and tissue inhibitor of MMP1 (TIMP-1) were measured. RESULTS The sST2 levels were higher in Group B than in Group A (23.9±3.3 vs. 30.9±5.0 ng/mL, P<0.000). In multivariable logistic regression analysis, sST2 was the only independent parameter for predicting left atrial LVZ (odds ratio, 1.611 [1.379-1.882]; P<0.001). The cut-off value of sST2 obtained by receiver operating characteristic (ROC) analysis was 26.65 ng/mL for prediction of LVZ (sensitivity: 86.5%, specificity: 84.8%). The under-curve area was 0.895 (0.842-0.948) (P<0.001). At 12-month follow-up, patients with sST2 <26.65 ng/mL had more patients free from atrial arrhythmias compared to patients with sST2 >26.65 ng/mL (88.6% vs. 69.8%, P<0.01). CONCLUSIONS We demonstrated that sST2 levels are higher in pAF patients with LVZ >20% compared to those with a smaller LVZ. Also increased sST2 levels can serve as a novel predictor of AF recurrence rate in patients who have undergone RFCA.

Ghrelin up-regulates cartilage-specific genes via the ERK/STAT3 pathway in chondrocytes of patients with adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a severe spinal deformity that often occurs during puberty. The occurrence of AIS is suggested to be related to abnormal development of cartilage. Our previous study found increased serum ghrelin levels in AIS patients that may linked to the development of AIS. However, whether ghrelin affects cartilage in AIS patients is unclear. We used quantitative real-time PCR (qRT-PCR) and immunohistochemistry to detect the expression of cartilage-specific genes and the ghrelin receptor, growth hormone secretagogue receptor (GHSR). The mRNA and protein levels of collagen II (COLII), SOX9, AGGRECAN (ACAN) and GHSR were higher in AIS patients than in controls. In addition, the protein levels of GHSR downstream signaling pathway members p-STAT3 (Ser727), and p-ERK1/2 were increased. Furthermore, we treated chondrocytes from AIS patients with 100 nM ghrelin, the cell proliferation assay and Western blotting showed that ghrelin promotes chondrocyte proliferation and enhances COLII, SOX9, ACAN, p-ERK1/2 and p-STAT3 expression, respectively. Interestingly, all these observed alterations were abolished by ghrelin + [D-Lys3]-GHRP-6 (a ghrelin receptor inhibitor) treatment. And after U0126 (an inhibitor of ERK1/2 phosphorylation) treatment, ERK1/2 and STAT3 (Ser727) phosphorylation was simultaneously suppressed indicating that ERK1/2 is an upstream pathway protein of STAT3 (Ser727). In conclusion, ghrelin plays an important role in upregulating cartilage-specific genes on AIS primary chondrocytes by activating ERK/STAT3 signaling pathway.

IL-37 alleviates house dust mite-induced chronic allergic asthma by targeting TSLP through the NF-κB and ERK1/2 signaling pathways.

Interleukin (IL)-37 has been described as a negative regulator of immune responses and is critical for asthma pathogenesis, but the mechanisms behind the protective role of IL-37 against allergic asthma are less well understood. We show here that IL-37 administered intranasally inhibited house dust mite (HDM)-induced chronic airway eosinophilic inflammation, goblet cell hyperplasia, peribronchial collagen deposition and airway hyperresponsiveness (AHR) to methacholine. In contrast to a weakened Th2 response in the lung that was characterized by the downregulation of Th2-associated cytokines and chemokines in IL-37-treated mice, IL-37 has no effect on relevant markers of systemic Th2 immune including serum immunoglobulins expression and in vitro production of Th2-associated cytokines by splenocytes on HDM recall. We demonstrated that the production of thymic stromal lymphopoietin (TSLP) in the lung tissue was associated with IL-37. Importantly, compared with IL-37 alone, TSLP coadministration with IL-37 restored HDM-induced airway inflammation and structural alterations, increased AHR to methacholine and promoted Th2-associated cytokine production. We further found that IL-37 inhibited the induction of TSLP expression by the main antigen of house dust mite, Der p1, by suppressing NF-κB and extracellular signal regulated kinase 1/2 (ERK1/2) activation in human bronchial epithelial (16-HBE) cells in vitro. These data highlight the importance of TSLP in IL-37-mediated protective role in asthma. IL-37 might represent a useful innovative and alternative therapy to control TSLP production in the airway.

Cavotricuspid isthmus ablation using ablation index in typical right atrial flutter.

BACKGROUND: Ablation index (AI) has been evaluated as guidance quality marker for pulmonary vein isolation, but not for linear ablation of the cavotricuspid isthmus (CTI) for typical right atrial flutter (AFL). We thus studied the feasibility and effectiveness of AI-guided CTI for AFL. METHODS: Procedural and 6-month outcomes of ablation for AFL were retrospectively compared between consecutive patients undergoing either AI-guided ablation of CTI (n = 43; AI target of 500 for anterior 2/3 segments and 400 for posterior 1/3 segments) or contact force (CF)-guided ablation (n = 42) at a single center. Each Visitag dataset from all patients in each group was analyzed. RESULTS: AI guidance vs CF guidance was associated with: higher first-pass conduction block of CTI (93.0% vs 76.2%, P = .03) with similar ablation time; similar acute spontaneous CTI reconnection 2.3% vs 9.5%, P = .343); fewer radiofrequency (RF) applications (10.1 ± 2.8 vs 11.5 ± 3.0, P = .031) needed to achieve CTI directional block; significantly higher mean ablation time, impedance drop, force time integral and AI and similar mean CF and power of each VisiTag point. One inguinal hematoma and one pseudoaneurysm developed in the AI and CF groups, respectively. Recurrent AFL was recorded in two (4.7%) AI-group patients and four (9.5%) CF-group patients (P = .650). CONCLUSION: AI-guided ablation of CTI line for AFL appears feasible and effective with similar ablation time, fewer RF applications, a higher rate of first-pass conduction block, and no additional complications.

Catheter ablation of ventricular arrhythmias with QRS morphology resembling that of aortic sinus cusp arrhythmias: Significance of mapping the left pulmonary sinus cusp.

BACKGROUND: There is a close anatomical relationship between aortic sinus cusp (ASC) and the left pulmonary sinus cusp (LPSC). PURPOSE: The study was to investigate the significance of mapping and ablation of LPSC for ventricular arrhythmias (VAs) with QRS morphology resembling that of ASC arrhythmias. METHODS: In 33 consecutive patients undergoing successful catheter ablation of idiopathic VAs with ASC arrhythmia-like QRS morphology, LPSC was mapped carefully. RESULTS: Among the 33 patients studied, QRS morphology resembled that of arrhythmias of either right or left coronary cusp (LCC or RCC) origin in 17 and 16 patients, respectively. Out of 12 arrhythmias with the earliest potential in LCC during left-sided mapping, an earlier potential in LPSC than in LCC was recorded in 2 arrhythmias, the same earliest potential in LPSC as in LCC was recorded in 6 arrhythmias, and 5 (42%) were finally ablated successfully in LPSC using the reversed U curve. Out of 16 arrhythmias with the earliest potential in the RCC during left-sided mapping, an earlier potential in LPSC than in RCC was recorded in 4 arrhythmias, the same earliest potential in LPSC as in RCC was recorded in 3 arrhythmias, and 4 (25%) were finally ablated successfully in LPSC using the reversed U curve. CONCLUSIONS: For VAs with ASC arrhythmia-like QRS morphology, mapping in LPSC could have unique electrophysiologic characteristics, and some of them could be eliminated in LPSC using reversed U curve.

Epigenetic modification and inheritance in sexual reversal of fish.

Environmental sex determination (ESD) occurs in divergent, phylogenetically unrelated taxa, and in some species, co-occurs with genetic sex determination (GSD) mechanisms. Although epigenetic regulation in response to environmental effects has long been proposed to be associated with ESD, a systemic analysis on epigenetic regulation of ESD is still lacking. Using half-smooth tongue sole (Cynoglossus semilaevis) as a model-a marine fish that has both ZW chromosomal GSD and temperature-dependent ESD-we investigated the role of DNA methylation in transition from GSD to ESD. Comparative analysis of the gonadal DNA methylomes of pseudomale, female, and normal male fish revealed that genes in the sex determination pathways are the major targets of substantial methylation modification during sexual reversal. Methylation modification in pseudomales is globally inherited in their ZW offspring, which can naturally develop into pseudomales without temperature incubation. Transcriptome analysis revealed that dosage compensation occurs in a restricted, methylated cytosine enriched Z chromosomal region in pseudomale testes, achieving equal expression level in normal male testes. In contrast, female-specific W chromosomal genes are suppressed in pseudomales by methylation regulation. We conclude that epigenetic regulation plays multiple crucial roles in sexual reversal of tongue sole fish. We also offer the first clues on the mechanisms behind gene dosage balancing in an organism that undergoes sexual reversal. Finally, we suggest a causal link between the bias sex chromosome assortment in the offspring of a pseudomale family and the transgenerational epigenetic inheritance of sexual reversal in tongue sole fish.

Lightweight Biometric Sensing for Walker Classification Using Narrowband RF Links.

This article proposes a lightweight biometric sensing system using ubiquitous narrowband radio frequency (RF) links for path-dependent walker classification. The fluctuated received signal strength (RSS) sequence generated by human motion is used for feature representation. To capture the most discriminative characteristics of individuals, a three-layer RF sensing network is organized for building multiple sampling links at the most common heights of upper limbs, thighs, and lower legs. The optimal parameters of sensing configuration, such as the height of link location and number of fused links, are investigated to improve sensory data distinctions among subjects, and the experimental results suggest that the synergistic sensing by using multiple links can contribute a better performance. This is the new consideration of using RF links in building a biometric sensing system. In addition, two types of classification methods involving vector quantization (VQ) and hidden Markov models (HMMs) are developed and compared for closed-set walker recognition and verification. Experimental studies in indoor line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios are conducted to validate the proposed method.