Corneal stromal lenticule transplantation for the treatment of congenital optic disc pit maculopathy : a case report and review.

BACKGROUND: Congenital optic disc pit (ODP) is a relatively uncommon congenital anomaly of the optic disc, which seriously affects the patient's vision when combined with optic disc pit maculopathy(ODP-M). Currently, the treatment of ODP-M remains a clinical challenge and a focus of research. CASE PRESENTATION: A boy had a pit in the inferotemporal segment of the optic disc with ODP-M. Optical Coherence Tomography(OCT) showed ODP and serous retinal detachment. He was treated with pars plana vitrectomy(PPV), followed by Corneal Stromal Lenticule (CSL) sealing and C3F8 tamponade. In the end, significant anatomical improvement was achieved, and the Best Corrected Visual Acuity(BCVA) was improved. CONCLUSIONS: The CSL transplantation may be a viable therapeutic option for improving ODP-M with stable anatomical and functional result. However, more cases and longer follow-up are needed to confirm the safety and effectiveness of the technology.

Immune and inflammatory insights in atherosclerosis: development of a risk prediction model through single-cell and bulk transcriptomic analyses.

Background: Investigation into the immune heterogeneity linked with atherosclerosis remains understudied. This knowledge gap hinders the creation of a robust theoretical framework essential for devising personalized immunotherapies aimed at combating this disease. Methods: Single-cell RNA sequencing (scRNA-seq) analysis was employed to delineate the immune cell-type landscape within atherosclerotic plaques, followed by assessments of cell-cell interactions and phenotype characteristics using scRNA-seq datasets. Subsequently, pseudotime trajectory analysis was utilized to elucidate the heterogeneity in cell fate and differentiation among macrophages. Through integrated approaches, including single-cell sequencing, Weighted Gene Co-expression Network Analysis (WGCNA), and machine learning techniques, we identified hallmark genes. A risk score model and a corresponding nomogram were developed and validated using these genes, confirmed through Receiver Operating Characteristic (ROC) curve analysis. Additionally, enrichment and immune characteristic analyses were conducted based on the risk score model. The model's applicability was further corroborated by in vitro and in vivo validation of specific genes implicated in atherosclerosis. Result: This comprehensive scRNA-seq analysis has shed new light on the intricate immune landscape and the role of macrophages in atherosclerotic plaques. The presence of diverse immune cell populations, with a particularly enriched macrophage population, was highlighted by the results. Macrophage heterogeneity was intricately characterized, revealing four distinct subtypes with varying functional attributes that underscore their complex roles in atherosclerotic pathology. Intercellular communication analysis revealed robust macrophage interactions with multiple cell types and detailed pathways differing between proximal adjacent and atherosclerotic core groups. Furthermore, pseudotime trajectories charted the developmental course of macrophage subpopulations, offering insights into their differentiation fates within the plaque microenvironment. The use of machine learning identified potential diagnostic markers, culminating in the identification of RNASE1 and CD14. The risk score model based on these biomarkers exhibited high accuracy in diagnosing atherosclerosis. Immune characteristic analysis validated the risk score model's efficacy in defining patient profiles, distinguishing high-risk individuals with pronounced immune cell activities. Finally, experimental validation affirmed RNASE1's involvement in atherosclerotic progression, suggesting its potential as a therapeutic target. Conclusion: Our findings have advanced our understanding of atherosclerosis immunopathology and paved the way for novel diagnostic and therapeutic strategies.

Covering corneal stromal lenticule for macular hole in pathological myopia.

AIM: To evaluate the clinical effect of a new surgery technique (covering corneal stromal lenticule, CSL) for macular hole (MH) in pathological myopia. METHODS: This was a prospective non-randomized series case study. Fourteen eyes of 14 patients whose axial length were more than 29 mm and suffered from MH and macular hole retinal detachment (MHRD) were included in this study. All cases were treated with 25-gauge pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling, covering CSL and C3F8 gas tamponade. These cases were followed for 6mo, and the best-corrected visual acuity (BCVA), healing status of MH, the reattached rate of retinal detachment (RD), and reoperation rate were analyzed. RESULTS: All cases were successfully performed the surgery and the postoperative follow-up was completed. After surgery, MHs were healed in all 14 eyes (100%, 14/14) after assessed by optical coherence tomography. The reattachment of retina was achieved in all 6 eyes (100%, 6/6) with MHRD. BCVA was improved in 12 eyes (85.71%, 12/14), and had no significant change in 2 eyes (14.29%, 2/14). The overall mean BCVA was improved from 1.80±0.77 to 0.82±0.46 logMAR (F=10.46, P<0.01). No serious complications occurred in all cases. CONCLUSION: The new surgery technique (covering CSL) has high reattached rate of RD and high healing rate of MH in pathological myopia in the preliminary study. And it can effectively improve the visual function of patients. This new technique offers meaningful new ideas for treating refractory MH in pathological myopia.

Experimental study of intramodal XPM reduction by intramodal dispersion in weakly coupled FMF.

The understanding of nonlinear propagation effects in low-crosstalk few-mode fiber is crucial for a weakly coupled mode-division multiplexed system. In this Letter, we report the first, to the best of our knowledge, experimental verification of the advantage of intramodal dispersion on mitigating intramodal cross-phase modulation in a weakly coupled few-mode fiber transmission. The experimental system is established over a 70-km multiple-ring-core few-mode fiber accommodating 6 linearly polarized modes, based on which the influences of intramodal cross-phase modulation on transmission performances of each linearly polarized mode are evaluated. Experimental results show that the intramodal cross-phase modulation of degenerate linearly polarized modes with much larger intramodal dispersion values are significantly weaker than those of non-degenerate linearly polarized modes, in which the maximum suppression of intramodal cross-phase modulation noise is up to 9.7 dB. We believe that this work would be beneficial to practical applications of weakly coupled mode-division multiplexing technologies.

112-GBaud mode-division-multiplexing IM-DD transmission beyond net 6.4†Tb/s over weakly coupled FMF for optical interconnections.

Weakly coupled mode-division-multiplexing (MDM) systems based on intensity modulation and direct detection (IM-DD) are a good candidate for further improving the capacity of short-reach optical interconnections. However, restrained by the modal crosstalk of the transmission link and the reception of degenerate mode groups (DMGs) utilizing bandwidth-limited multimode photodetectors (PDs), high-speed MDM IM-DD has encountered a capacity bottleneck. In this Letter, we investigate a high-speed weakly coupled MDM IM-DD transmission system utilizing a degenerate mode diversity receiver scheme adopting high-bandwidth single-mode PDs over a multiple-ring-core (MRC) few-mode fiber (FMF) and a low-crosstalk mode multiplexer/demultiplexer (MUX/DMUX). An MDM IM-DD transmission with four DMGs and eight wavelengths is experimentally demonstrated with 112-GBaud four-level pulse-amplitude modulation (PAM4) and probabilistically shaped PAM8 per lane over 200-m weakly coupled MRC-FMF. To the best of our knowledge, this is the first experimental demonstration of the MDM IM-DD transmission system with up to 112-GBaud baud rate and beyond 6.4-Tb/s net rate. Meanwhile, the experimental results show that the proposed MDM IM-DD transmission link has a superior performance only adopting a low-complexity feedforward equalizer, making it a promising candidate for high-speed optical interconnections.

Integrated transcriptome and metabolome reveal that SlSYTA modulates ROS responses driving resistance defense in Solanum lycopersicum.

Synaptotagmin A (SYTA), renowned for its indispensable role in mammalian vesicle trafficking, has recently captured attention in plant biology owing to its potential regulatory functions. This study meticulously delves into the involvement of Solanum lycopersicum SlSYTA in plant immunity, focusing on its response to an array of pathogens affecting tomatoes. Our comprehensive inquiry uncovers that SlSYTA overexpression heightens susceptibility to tobacco mosaic virus (TMV), Phytophthora capsici, Botrytis cinerea, and Pseudomonas syringae pv. tomato DC3000, whereas RNA interference (RNAi) plants show a robust and encompassing resistance to these pathogens. Remarkably, our findings shed light on SlSYTA's negative regulation of pivotal aspects of pattern-triggered immunity (PTI) defense, notably hindering the reactive oxygen species (ROS) burst, impeding stomatal closure, and curtailing callose deposition. Through meticulous scrutiny via transcriptome and metabolome analyses, our studies reveal SlSYTA's profound impact on diverse plant defense pathways, specifically influencing phenylpropanoid metabolism, hormone signaling, and oxidative phosphorylation, primarily via NADPH synthesis modulation in the pentose phosphate pathway, and ultimately interplay within ROS signaling. Collectively, our research presents groundbreaking insights into the intricate molecular mechanisms governing plant immunity, emphasizing the significant role of SlSYTA in orchestrating plant responses to biotic stress.

Experimental investigation of a Tonpilz transducer operating in the frequency band of 20-80 kHz (L).

The drive-stack design principle for the Tonpilz transducer aiming to transmit the acoustic signal in an ultra-wideband has been proposed [(2023). J. Acoust. Soc. Am. 154, 3709-3725], in which the design method is obtained and validated through simulation. This letter presents the experimental investigation of a fabricated transducer prototype and gives the measurement results of electroacoustic performance, including the electrical admittance, transmitting voltage response, directivity beam pattern, electroacoustic efficiency, and source level. The results indicate that the transducer can operate in the frequency band from 20 to 80 kHz without deep response notches within the band.

Quasi-Reaction Coarse-Grained Simulation: Unveiling the Mesoscale Interfacial Response of CSH/PVA Fiber.

The lack of a comprehensive force field and understanding at the mesoscale for hydrated calcium silicate (CSH)/polyvinyl alcohol (PVA) fiber has hindered the upscaling and bridging of nanoscale to macroscale phenomena. In this study, we propose a coarse-grained (CG) force field that incorporates bond-breaking operations to endow fiber reactivity, abrasion, and fracture properties. By employing a cubic lattice modeling, we effectively address the challenges associated with semicrystalline relaxation of fibers. For the first time, quasi-reaction CG simulation successfully replicates slip-hardening behaviors and surface abrasion. We demonstrate that abrasion improves interface load transfer and triggers slip-hardening by redistributing stress. Additionally, the influences of single and coupled factors, such as nonbonding interactions and surface roughness, are investigated. Mesoscale understanding provides insights for enabling precise control of load transfer paths and fabrication of interface damage-predictable materials.

Weight-adaptive joint mixed-precision quantization and pruning for neural network-based equalization in short-reach direct detection links.

Neural network (NN)-based equalizers have been widely applied for dealing with nonlinear impairments in intensity-modulated direct detection (IM/DD) systems due to their excellent performance. However, the computational complexity (CC) is a major concern that limits the real-time application of NN-based receivers. In this Letter, we propose, to our knowledge, a novel weight-adaptive joint mixed-precision quantization and pruning approach to reduce the CC of NN-based equalizers, where only integer arithmetic is taken into account instead of floating-point operations. The NN connections are either directly cutoff or represented by a proper number of quantization bits by weight partitioning, leading to a hybrid compressed sparse network that computes much faster and consumes less hardware resources. The proposed approach is verified in a 50-Gb/s 25-km pulse amplitude modulation (PAM)-4 IM/DD link using a directly modulated laser (DML) in the C-band. Compared with the traditional fully connected NN-based equalizer operated with standard floating-point arithmetic, about 80% memory can be saved at a minimum network size without degrading the system performance. Quantization is also shown to be more suitable to over-parameterized NN-based equalizers compared with NNs selected at a minimum size.

Early Prone Position Ventilation in the Efficacy for Severe Hypoxemia and Neurological Complications Following Acute Type A Aortic Dissection (TAAD) Surgery.

OBJECTIVE: To analyze the efficacy of early prone position ventilation in the treatment of severe hypoxemia after surgery for acute type A aortic dissection (TAAD). METHODS: The patients were divided into a control group and a treatment group. Parameters assessed included blood gas analysis indicators [arterial oxygen partial pressure (PaO2). RESULTS: (1) Blood gas analysis: Before treatment, there was no significant difference in PaO2, SpO2, and OI levels between the two groups; after treatment, the PaO2, SpO2, and OI levels in both groups significantly increased compared to pre-treatment, with a more pronounced improvement in the treatment group than in the control group (p < 0.05). (2) Hemodynamics: Before treatment, there was no significant difference in MAP and HR levels between the two groups; after treatment, the MAP levels increased significantly in both groups compared to pre-treatment, while HR levels decreased significantly, with no significant difference between the groups. (3) Prognosis recovery: MV time, ICU stay, and total hospital stay were significantly lower in the treatment group than in the control group; the 30-day mortality rate was 14.58% in the control group and 12.50% in the treatment group, with no significant difference in 30-day mortality rate between the groups. CONCLUSION: Early prone position ventilation has shown promising application in the treatment of severe hypoxemia after TAAD surgery. Compared to traditional supine position ventilation, the use of early prone position ventilation can further improve blood gas analysis indicators in patients, and shorten MV time, ICU stay, and total hospital stay, thereby accelerating patient recovery.

Mode-division-multiplexing self-homodyne coherent transmission over a weakly coupled few-mode fiber for optical interconnections.

Self-homodyne coherent transmission has recently received extensive investigation as a coherent lite candidate for high-speed short-reach optical networks. In this Letter, we propose a weakly coupled mode-division-multiplexing (MDM) self-homodyne coherent scheme using a multiple-ring-core few-mode fiber, in which one of the modes transmits a self-homodyne local oscillator (LO) and the rest are utilized for carrying signals. Multiple rings of index perturbations in the fiber core are applied to achieve low modal crosstalk, allowing the signals and the remote LO to be transmitted independently. We experimentally demonstrate a 7.2-Tb/s (5.64-Tb/s net rate) self-homodyne coherent transmission with an 800-Gb/s data rate for each of the nine information-bearing modes formatted in 80-GBaud probabilistic constellation-shaped 64-quadrature-amplitude modulation. To the best of our knowledge, this is the first experimental demonstration of an MDM self-homodyne coherent transmission with up to 10 spatial modes. The proposed scheme may pave the way for future high-capacity data center interconnections.

Results and Follow-Up of a Sequential Q-Switched Laser Therapy for Nevus of Ota in Infants.

Background and Aim: There is a dearth of scholarly investigation pertaining to the effectiveness and safety of laser therapy for nevus of Ota manifestation in infants. The objective of this study is to examine the efficacy and safety of administering laser therapy at an early stage to treat nevus of Ota in infants. Methods: A total of 102 infants below the age of one who had nevus of Ota were treated at the Laser Center at Hangzhou Third People's Hospital. The treatment approach involved a combination of the Q-switched laser (with a wavelength of 755 nm) and the Q-switched laser (with a wavelength of 1064 nm). The treatment sessions were conducted at six-month intervals. Prior to and after each session, photographs and relevant parameters were documented, including any skin reactions. Subsequent follow-up was conducted through phone calls, WeChat, and text messages, and the parents/guardians of the infants completed a general questionnaire as well as Conner's Abbreviated Symptom Questionnaire. Results: Laser therapy exhibited significant efficacy in the treatment of nevus of Ota in infants. Success rates reached 88.7% after four sessions and 99.3% after seven sessions. No instances of serious adverse reactions, except for pain, were reported. Among the 47 infants subject to follow-up, 14 experienced a recurrence, resulting in a recurrence rate of 29.8%. Factors contributing to these recurrences included lesion size, subtypes, exposure to the sun, and location. Subsequent laser treatments, typically involving two to three additional sessions, proved effective in mitigating recurrences. Notably, none of the infants exhibited any signs of fear, anxiety, or other psychological abnormalities following laser therapy, and the overall satisfaction rate was markedly high. Conclusion: Commencing laser therapy promptly for nevus of Ota in infants is recommended. This early intervention significantly contributes to the overall well-being of infants, addressing both physical and psychological aspects.

Gradient-descent noise whitening techniques for short-reach IM-DD optical interconnects with severe bandwidth limitation.

Bandwidth limitation in optoelectrical components and the chromatic dispersion-induced power fading phenomenon cause severe inter-symbol interference (ISI) in high-speed intensity modulation and direct detection (IM-DD) optical interconnects. While the equalizer implemented in the receiver's digital signal processing procedure can mitigate ISI, it also inevitably enhances the noise located in the decayed frequency region, known as equalization-enhanced colored noise (EECN). Additionally, the nonlinear impairments of the modulator and photodetector also deteriorate the performance of the IM-DD system, especially for high-order modulation formats. In this work, we propose a gradient-descent noise whitening (GD-NW) algorithm to address EECN and extend it by introducing nonlinear kernels to simultaneously mitigate EECN and nonlinear impairments. The proposed algorithms are compared with conventional counterparts in terms of the achievable baud rate and the receiver optical power sensitivity. As a proof-of-concept experiment, we validate the principles of the proposed algorithms by successfully transmitting 360-GBd on-off-keying (OOK) and 180-GBd 4-level pulse-amplitude-modulation (PAM-4) signals in the back-to-back case under a 62-GHz brick-wall bandwidth limitation. 280-GBd OOK and 150-GBd PAM-4 transmissions are also demonstrated over 1-km standard single-mode fiber with a bit error rate below 7% hard-decision forward error correction aided by the proposed approach.

Bandwidth extension of the Tonpilz transducer using high-order longitudinal vibrations.

Tonpilz transducers mainly work near the first-order longitudinal resonance. Until now, the cognition, research, and application of third-order resonance and above are still inadequate. By coupling the first-order resonance with other high-order resonances, it is possible to extend the bandwidth of the Tonpilz transducer to more than two octaves. Three difficulties hinder the achievement of the ultra-wideband, including how to activate consecutive high-order resonances, how to eliminate the response notches between resonances, and how to control the response values of resonances to reduce band fluctuation. This paper addresses these key issues. The results show that the number, position, length, and applied voltage of the drive-stack all significantly affect the band. We finally propose a drive-stack design principle that can activate the first four longitudinal resonances with close response values to be coupled to form the ultra-wideband. When applying this principle to the Tonpilz transducer, many variables need to be optimized. To solve this problem, an efficient and accurate optimization technology is proposed, consisting of simulated annealing initial optimization and finite element re-optimization, through which an ultra-wideband covering the frequency range of 19.5-90 kHz is obtained, verifying the effectiveness of the proposed principle. The designed transducer has three drive-stacks, and the band contains four longitudinal resonances.

Fast polarization state tracking for dual-polarization direct detection with Jones-space field recovery.

Direct detection system is expected to possess the phase and polarization diversity in order to achieve high spectral efficiency and fiber impairment compensation such as chromatic dispersion and polarization rotation. In this Letter, we theoretically extend the concept of the proposed Jones-space field recovery (JSFR) to include a dynamic polarization rotation matrix and experimentally demonstrate the rapid polarization state tracking ability of the JSFR receiver based on a 3 × 3 optical coupler. Under a rotation of the state of polarization at a rate of 1 Mrad/s, we successfully transmit 59-GBd dual-polarization 16-ary quadrature-amplitude-modulation signals over an 80-km standard single-mode fiber based on a decision-directed least mean square (DD-LMS) or a recursive least square (DD-RLS), with a bit-error rate below the 14% hard-decision forward error correction threshold of 1 × 10-2. The experimental results indicate that the legacy polarization tracking algorithms designed for coherent optical communication are also applicable for this direct detection scheme. To our best knowledge, this work demonstrates the first polarization rotation-tolerant direct detection system with phase and polarization diversity, providing a low-cost and high-speed solution for short-reach communications.

Deep transfer learning-based variable Doppler underwater acoustic communications.

This paper proposes a deep transfer learning (DTL)-based variable Doppler frequency-hopping binary frequency-shift keying underwater acoustic communication system. The system uses a convolutional neural network (CNN) as the demodulation module of the receiver. This approach directly demodulates the received signal without estimating the Doppler. The DTL first uses the simulated communication signal data to complete the CNN training. It then copies a part of the convolution layers from the pre-trained CNN to the target CNN. After randomly initializing the remaining layers for the target CNN, it is trained by the data samples from the specific communication scenarios. During the training process, the CNN learns the corresponding frequency from each symbol in the selected frequency-hopping group through the Mel-spectrograms. Simulation and experimental data processing results show that the performance of the proposed system is better than conventional systems, especially when the transmitter and receiver of the communication system are in variable speed motion in shallow water acoustic channels.

Treatment of Combined Freckles with Chloasma Using Q-Switched 1064 nm Laser.

Objective: The present study observed the therapeutic effect and possible side effects of Q-switch 1064-nm laser with large-spot and low-energy technology in the treatment of patients with combined freckles and chloasma. Methods: A Q1064-nm laser with a large-spot diameter of 6-8 mm, energy level of 2.0-3.3 J/cm2, frequency of 10 Hz, and pulse width of 10 ns was employed for the treatment. Each patient underwent treatment 10-15 times, with an interval of 10-15 days each time. Facial care was administered before and after treatment; attention was paid to cleaning and moisturizing, avoiding light, and using sunscreens strictly. The therapeutic effects were observed and evaluated. Results: Freckles basically subsided (effective rate = 100%) and chloasma faded (effective rate = 39.4%). Furthermore, whitening and delicacy improvement were observed in the surrounding normal skin area. After laser treatment, confocal laser scanning microscopy revealed a large number of melanin particles in the upper part of the granular layer. Moreover, the amount of melanin in the middle and lower parts of the basal layer and spinous layer was significantly decreased. None of the patients developed postinflammatory pigmentation. Conclusion: In the treatment of freckles with chloasma, Q 1064-nm laser large-spot, low-energy technology not only removed freckles and faded chloasma but, most importantly, also reduced the incidence of postinflammatory pigmentation and improved patient satisfaction. This provided new methods and ideas for freckle laser treatment.

Satellite record reveals 1960s acceleration of Totten Ice Shelf in East Antarctica.

Wilkes Land and Totten Glacier (TG) in East Antarctica (EA) have been losing ice mass significantly since 1989. There is a lack of knowledge of long-term mass balance in the region which hinders the estimation of its contribution to global sea level rise. Here we show that this acceleration trend in TG has occurred since the 1960s. We reconstruct ice flow velocity fields of 1963-1989 in TG from the first-generation satellite images of ARGON and Landsat-1&4, and build a five decade-long record of ice dynamics. We find a persistent long-term ice discharge rate of 68 ± 1 Gt/y and an acceleration of 0.17 ± 0.02 Gt/y2 from 1963 to 2018, making TG the greatest contributor to global sea level rise in EA. We attribute the long-term acceleration near grounding line from 1963 to 2018 to basal melting likely induced by warm modified Circumpolar Deep Water. The speed up in shelf front during 1973-1989 was caused by a large calving front retreat. As the current trend continues, intensified monitoring in the TG region is recommended in the next decades.

Amarogentin inhibits vascular smooth muscle cell proliferation and migration and attenuates neointimal hyperplasia via AMPK activation.

OBJECTIVES: Recent studies validated the expression of extraoral bitter taste receptors and established the importance of regulatory functions that are associated with various cellular biological processes of these receptors. However, the importance of bitter taste receptors' activity in neointimal hyperplasia has not yet been recognized. The bitter taste receptors activator amarogentin (AMA) is known to regulate a variety of cellular signals, including AMP-activated protein kinase (AMPK), STAT3, Akt, ERK, and p53, which are associated with neointimal hyperplasia. MATERIALS AND METHODS: The present study assessed the effects of AMA on neointimal hyperplasia and explored the potential underlying mechanisms. RESULTS: No cytotoxic concentration of AMA significantly inhibited the proliferation and migration of VSMCs induced by serum (15 % FBS) and PDGF-BB. In addition, AMA significantly inhibited neointimal hyperplasia of the cultured great saphenous vein in vitro and ligated mouse left carotid arteries in vivo, while the inhibitory effect of AMA on the proliferation and migration of VSMCs was mediated via the activation of AMPK-dependent signaling, which could be blocked via AMPK inhibition. CONCLUSION: The present study revealed that AMA inhibited the proliferation and migration of VSMCs and attenuated neointimal hyperplasia, both in ligated mice carotid artery and cultured saphenous vein, which was mediated via a mechanism that involved AMPK activation. Importantly, the study highlighted the potential of AMA to be explored as a new drug candidate for neointimal hyperplasia.

Automated extraction of baleen whale calls based on the pseudo-Wigner-Ville distribution.

Baleen whales produce a wide variety of frequency-modulated calls. Extraction of the time-frequency (TF) structures of these calls forms the basis for many applications, including abundance estimation and species recognition. Typical methods to extract the contours of whale calls from a spectrogram are based on the short-time Fourier transform and are, thus, restricted by a fixed TF resolution. Considering the low-frequency nature of baleen whale calls, this work represents the contours using a pseudo-Wigner-Ville distribution for a higher TF resolution at the cost of introducing cross terms. An adaptive threshold is proposed followed by a modified Gaussian mixture probability hypothesis density filter to extract the contours. Finally, the artificial contours, which are caused by the cross terms, can be removed in post-processing. Simulations were conducted to explore how the signal-to-noise ratio influences the performance of the proposed method. Then, in experiments based on real data, the contours of the calls of three kinds of baleen whales were extracted in a highly accurate manner (with mean deviations of 5.4 and 0.051 Hz from the ground-truth contours at sampling rates of 4000 and 100 Hz, respectively) with a recall of 75% and a precision of 78.5%.