112 research outputs found

    Large-scale displacement along the Altyn Tagh Fault (North Tibet) since its Eocene initiation: Insight from detrital zircon U–Pb geochronology and subsurface data

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    International audienceMarking the northern boundary of the Tibetan plateau, the Altyn Tagh fault plays a crucial role in accommodatingthe Cenozoic crustal deformation affecting the plateau. However, its initiation time and amount of offset are stillcontroversial despite being key information for the understanding of Tibet evolution. In this study, we present1122 single LA-ICP-MS detrital zircon U–Pb ages obtained from 11 Mesozoic to Cenozoic sandstone samples, collectedalong two sections in the northwestern Qaidam basin (Eboliang and Huatugou). These data are combinedwith new3D seismic reflection profiles to demonstrate that: (1) fromthe Paleocene to early Eocene, the Eboliangsection was approximately located near the present position of Anxi, 360 ± 40 km southwest from its currentlocation along the Altyn Tagh fault, and sediments were mainly derived from the Altyn Tagh Range. At thesame period, the Huatugou section was approximately located near the present position of Tula, ca. 360 kmsouthwest from its current location along the Altyn Tagh fault, and the Eastern Kunlun Range represented a significantsediment source. (2) Left-lateral strike-slip movement along the Altyn Tagh fault initiated during theearly-middle Eocene, resulting in northeastward displacement of the two sections. (3) By early Miocene, the intensivedeformation within the Altyn Tagh Range and northwestern Qaidam basin strongly modified the drainagesystem, preventing the materials derived fromthe Altyn Tagh Range to reach the Eboliang and the Huatugousections. The post-Oligocene clastic material in the western Qaidam basin is generally derived fromlocal sourcesand recycling of the deformed Paleocene to Oligocene strata. From these data, we suggest enhanced tectonic activitywithin the Altyn Tagh Range and northwestern Qaidam basin since Miocene time, and propose an earlymiddleEocene initiation of left-lateral strike-slip faulting leading to a 360 ± 40 km offset along the Altyn Taghfaul

    EEG-Derived Voice Signature for Attended Speaker Detection

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    \textit{Objective:} Conventional EEG-based auditory attention detection (AAD) is achieved by comparing the time-varying speech stimuli and the elicited EEG signals. However, in order to obtain reliable correlation values, these methods necessitate a long decision window, resulting in a long detection latency. Humans have a remarkable ability to recognize and follow a known speaker, regardless of the spoken content. In this paper, we seek to detect the attended speaker among the pre-enrolled speakers from the elicited EEG signals. In this manner, we avoid relying on the speech stimuli for AAD at run-time. In doing so, we propose a novel EEG-based attended speaker detection (E-ASD) task. \textit{Methods:} We encode a speaker's voice with a fixed dimensional vector, known as speaker embedding, and project it to an audio-derived voice signature, which characterizes the speaker's unique voice regardless of the spoken content. We hypothesize that such a voice signature also exists in the listener's brain that can be decoded from the elicited EEG signals, referred to as EEG-derived voice signature. By comparing the audio-derived voice signature and the EEG-derived voice signature, we are able to effectively detect the attended speaker in the listening brain. \textit{Results:} Experiments show that E-ASD can effectively detect the attended speaker from the 0.5s EEG decision windows, achieving 99.78\% AAD accuracy, 99.94\% AUC, and 0.27\% EER. \textit{Conclusion:} We conclude that it is possible to derive the attended speaker's voice signature from the EEG signals so as to detect the attended speaker in a listening brain. \textit{Significance:} We present the first proof of concept for detecting the attended speaker from the elicited EEG signals in a cocktail party environment. The successful implementation of E-ASD marks a non-trivial, but crucial step towards smart hearing aids.Comment: 8 pages, 2 figure

    Northward growth of the Qimen Tagh Range: A new model accounting for the Late Neogene strike-slip deformation of the SW Qaidam Basin

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    International audienceSituated along the western termination of the Eastern Kunlun Mountains, the Qimen Tagh Range represents a key area to understand the Cenozoic basin-range interactions between the northeastern Tibetan Plateau and the Qaidam Basin. Within that region, several huge bow-like fault systems such as the Kunbei and Qimen Tagh fault systems accommodate the transpressive deformation but their kinematic evolution is still highly debated. Newly acquired seismic profiles and isopach maps of the Late Eocene sediments strongly suggest that the Kunbei fault system (consisting of the Kunbei, Arlar and Hongliuquan faults) in the southwestern Qadaim Basin was initially a left-lateral strike-slip fault system rather than a thrusting system. Growth strata indicate an Early Miocene onset age for this strike-slip deformation. However, earthquake focal mechanisms show that the present-day tectonic pattern of this fault system is dominated by NE-SW transpression. As for the Qimen Tagh fault system, numerous linear geomorphic features and fault scarps indicate that it was again a strike-slip fault system. Deformed sediments within the Adatan Valley prove that strike-slip motion prevailed during the Pleistocene, yet the present day deformation is marked by NE-SW transpression. Collectively, the Kunbei and Qimen Tagh fault systems were initially left-lateral strike-slip fault systems that formed during Early Miocene and Pleistocene respectively. Colligating with these southward younging left-lateral strike-slip faulting ages and the fact that these convex-northward structures converge to the center segment of active Kunlun fault in the east, we thus considered the Kunbei and Qimen Tagh fault systems as former western segments of the Kunlun fault once located further south in the present-day location of that fault. These faults gradually migrated northward since the Early Miocene while their kinematics changed from left-lateral strike-slip motion to NE-SW transpression

    Speaking in Wavelet Domain: A Simple and Efficient Approach to Speed up Speech Diffusion Model

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    Recently, Denoising Diffusion Probabilistic Models (DDPMs) have attained leading performances across a diverse range of generative tasks. However, in the field of speech synthesis, although DDPMs exhibit impressive performance, their long training duration and substantial inference costs hinder practical deployment. Existing approaches primarily focus on enhancing inference speed, while approaches to accelerate training a key factor in the costs associated with adding or customizing voices often necessitate complex modifications to the model, compromising their universal applicability. To address the aforementioned challenges, we propose an inquiry: is it possible to enhance the training/inference speed and performance of DDPMs by modifying the speech signal itself? In this paper, we double the training and inference speed of Speech DDPMs by simply redirecting the generative target to the wavelet domain. This method not only achieves comparable or superior performance to the original model in speech synthesis tasks but also demonstrates its versatility. By investigating and utilizing different wavelet bases, our approach proves effective not just in speech synthesis, but also in speech enhancement

    Diagnosis of inter-turn short circuit fault in IPMSMs based on the combined use of greedy tracking and random forest

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    Inter-turn short circuit (ITSC) is a frequent fault of interior permanent magnet synchronous motors (IPMSM). If ITSC faults are not promptly monitored, it may result in secondary faults or even cause extensive damage to the entire motor. To enhance the reliability of IPMSMs, this paper introduces a fault diagnosis method specifically designed for identifying ITSC faults in IPMSMs. The sparse coefficients of phase current and torque are solved by clustering shrinkage stage orthogonal matching tracking (CcStOMP) in the greedy tracking algorithm.The CcStOMP algorithm can extract multiple target atoms at one time, which greatly improves the iterative efficiency. The multiple features are utilized as input parameters for constructing the random forest classifier. The constructed random forest model is used to diagnose ITSC faults with the results showing that the random forest model has a diagnostic accuracy of 98.61% using all features, and the diagnostic accuracy of selecting three of the most important features is still as high as 97.91%. The random forest classification model has excellent robustness that maintains high classification accuracy despite the reduction of feature vectors, which is a great advantage compared to other classification algorithms. The combination of greedy tracing and the random forest is not only a fast diagnostic model but also a model with good generalisation and anti-interference capability. This non-invasive method is applicable to monitoring and detecting failures in industrial PMSMs

    Mouse Model Established by Early Renal Transplantation After Skin Allograft Sensitization Mimics Clinical Antibody-Mediated Rejection

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    Antibody-mediated rejection (AMR) is the main barrier to renal graft survival, and mouse renal AMR models are important to study this process. Current mouse models are established by priming the recipient to donor skin for over 7 days before kidney transplantation. The robustness of AMR in these cases is too strong to mimic clinical AMR and it is unclear why altering the priming times ranging from 7 to 91 days fails to reduce the AMR potency in these models. In the present study, we found that the donor-recipient combination and skin graft size were determinants of donor-specific antibody (DSA) development patterns after skin transplantation. DSA-IgG was sustained for over 100 days after skin challenge, accounting for an identical AMR robustness upon different skin priming times over 7 days. However, decreasing the skin priming time within 7 days attenuated the robustness of subsequent renal allograft AMR in C3H to Balb/c mice. Four-day skin priming guaranteed that recipients develop acute renal AMR mixed with a high ratio of graft-infiltrating macrophages, renal grafts survived for a mean of 6.4 ± 2.1 days, characterized by typical AMR histological changes, such as glomerulitis, peritubular capillary (PTC) dilation, and capillaritis, deposition of IgG and C3d in PTCs, but less prevalence of microthrombus, whereas the cellular rejection histological change of tubulitis was absent to mild. With this scheme, we also found that the renal AMR model can be developed using common mouse strains such as C57BL/6 and Balb/c, with mean prolonged renal graft survival times of 14.4 ± 5.0 days. Finally, we proved that donor-matched skin challenge after kidney transplantation did not strongly affect DSA development and kidney graft outcome. These findings may facilitate an understanding and establishment of mouse renal allograft AMR models and promote AMR-associated studies

    A Randomly-Controlled Study on the Cardiac Function at the Early Stage of Return to the Plains after Short-Term Exposure to High Altitude

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    High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m) and returned to the plains (1500 m) after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP), left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), cardiac function index (Tei index) were tested. Levels of serum creatine kinase isoform MB (CK-MB), lactate dehydrogenase isoenzyme-1 (LDH-1), endothelin-1 (ET-1), nitrogen oxide (NO), serum hypoxia-inducible factor-1α (HIF-1α), 8-iso-prostaglandin F2α (8-iso PGF2α), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15th day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (P<0.01). We also found that changes in Tei index was positively correlated with mPAP, ET-1, HIF-1α and 8-iso PGF2α levels, and negatively correlated with the level of NO, LVEF, LVFS, CK-MB and LDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time

    The Prevalence of Immunologic Injury in Renal Allograft Recipients with De Novo Proteinuria

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    Post-transplant proteinuria is a common complication after renal transplantation; it is associated with reduced graft and recipient survival. However, the prevalence of histological causes has been reported with considerable variation. A clinico-pathological re-evaluation of post-transplant proteinuria is necessary, especially after dismissal of the term “chronic allograft nephropathy,” which had been considered to be an important cause of proteinuria. Moreover, urinary protein can promote interstitial inflammation in native kidney, whether this occurs in renal allograft remains unknown. Factors that affect the graft outcome in patients with proteinuria also remain unclear. Here we collected 98 cases of renal allograft recipients who developed proteinuria after transplant, histological features were characterized using Banff scoring system. Cox proportional hazard regression models were used for graft survival predictors. We found that transplant glomerulopathy was the leading (40.8%) cause of post-transplant proteinuria. Immunological causes, including transplant glomerulopathy, acute rejection, and chronic rejection accounted for the majority of all pathological causes of proteinuria. Nevertheless, almost all patients that developed proteinuria had immunological lesions in the graft, especially for interstitial inflammation. Intraglomerular C3 deposition was unexpectedly correlated with the severity of proteinuria. Moreover, the severity of interstitial inflammation was an independent risk factor for graft loss, while high level of hemoglobin was a protective factor for graft survival. This study revealed a predominance of immunological parameters in renal allografts with post-transplant proteinuria. These parameters not only correlate with the severity of proteinuria, but also with the outcome of the graft
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