173 research outputs found
SMURF: Spatial Multi-Representation Fusion for 3D Object Detection with 4D Imaging Radar
The 4D Millimeter wave (mmWave) radar is a promising technology for vehicle
sensing due to its cost-effectiveness and operability in adverse weather
conditions. However, the adoption of this technology has been hindered by
sparsity and noise issues in radar point cloud data. This paper introduces
spatial multi-representation fusion (SMURF), a novel approach to 3D object
detection using a single 4D imaging radar. SMURF leverages multiple
representations of radar detection points, including pillarization and density
features of a multi-dimensional Gaussian mixture distribution through kernel
density estimation (KDE). KDE effectively mitigates measurement inaccuracy
caused by limited angular resolution and multi-path propagation of radar
signals. Additionally, KDE helps alleviate point cloud sparsity by capturing
density features. Experimental evaluations on View-of-Delft (VoD) and
TJ4DRadSet datasets demonstrate the effectiveness and generalization ability of
SMURF, outperforming recently proposed 4D imaging radar-based
single-representation models. Moreover, while using 4D imaging radar only,
SMURF still achieves comparable performance to the state-of-the-art 4D imaging
radar and camera fusion-based method, with an increase of 1.22% in the mean
average precision on bird's-eye view of TJ4DRadSet dataset and 1.32% in the 3D
mean average precision on the entire annotated area of VoD dataset. Our
proposed method demonstrates impressive inference time and addresses the
challenges of real-time detection, with the inference time no more than 0.05
seconds for most scans on both datasets. This research highlights the benefits
of 4D mmWave radar and is a strong benchmark for subsequent works regarding 3D
object detection with 4D imaging radar
LXL: LiDAR Excluded Lean 3D Object Detection with 4D Imaging Radar and Camera Fusion
As an emerging technology and a relatively affordable device, the 4D imaging
radar has already been confirmed effective in performing 3D object detection in
autonomous driving. Nevertheless, the sparsity and noisiness of 4D radar point
clouds hinder further performance improvement, and in-depth studies about its
fusion with other modalities are lacking. On the other hand, most of the
camera-based perception methods transform the extracted image perspective view
features into the bird's-eye view geometrically via "depth-based splatting"
proposed in Lift-Splat-Shoot (LSS), and some researchers exploit other modals
such as LiDARs or ordinary automotive radars for enhancement. Recently, a few
works have applied the "sampling" strategy for image view transformation,
showing that it outperforms "splatting" even without image depth prediction.
However, the potential of "sampling" is not fully unleashed. In this paper, we
investigate the "sampling" view transformation strategy on the camera and 4D
imaging radar fusion-based 3D object detection. In the proposed model, LXL,
predicted image depth distribution maps and radar 3D occupancy grids are
utilized to aid image view transformation, called "radar occupancy-assisted
depth-based sampling". Experiments on VoD and TJ4DRadSet datasets show that the
proposed method outperforms existing 3D object detection methods by a
significant margin without bells and whistles. Ablation studies demonstrate
that our method performs the best among different enhancement settings
Evidence of Hadronic Emission from the brightest-of-all-time GRB 221009A
Acceleration of hadrons in relativistic shocks has been long expected and
invoked to model GRB high-energy photon and neutrino emissions. However, so far
there has been no direct observational evidence of hadronic emission from GRBs.
The B.O.A.T. ("brightest of all time") gamma-ray burst (GRB) 221009A had
extreme energies (with an isotropic energy exceeding erg) and was
detected in broad-band including the very-high-energy (VHE, )
band up to TeV. Here we perform a comprehensive spectral analysis of the
GRB from keV to TeV energy range and perform detailed spectral and light curve
modelings considering both the traditional synchrotron self-Compton process and
the electromagnetic (EM) cascade process initiated by hadronic interactions by
accelerated cosmic rays in the external shock. We find that the leptonic
scenario alone is not adequate to account for the observations, whereas the
proposed scenario with the combination of hadronic and leptonic components can
well reproduce the multi-wavelength spectra and the light curve. This result
reveals the existence of the accelerated hadronic component in the early
afterglow of this extreme burst. According to this scenario, the observed TeV
light curve should contain imprints of the prompt MeV emission.Comment: 15 pages, 4 figures, 3 tables. originally submitted version for
Nature Astronom
Differential of Frequency and Duration Mismatch Negativity and Theta Power Deficits in First-Episode and Chronic Schizophrenia
Background: Due to its impairment in patients with schizophrenia, mismatch negativity (MMN) generation has been identified as a potential biomarker for identifying primary impairments in auditory sensory processing. This study aimed to investigate the dysfunctional differences in different MMN deviants and evoked theta power in patients with first-episode schizophrenia (FES) and chronic schizophrenia (CS).Methods: We measured frequency and duration MMN from 40 FES, 40 CS, and 40 healthy controls (HC). Evoked theta power was analyzed by event-related spectral perturbation (ERSP) approaches.Results: Deficits in duration MMN were observed in both FES (p = 0.048, Bonferroni-adjusted) and CS (p < 0.001, Bonferroni-adjusted). However, deficits in frequency MMN were restricted to the CS (p < 0.001, Bonferroni-adjusted). Evoked theta power deficits were observed in both patient groups when compared with the HC (p FES = 0.001, p CS < 0.001, Bonferroni-adjusted), yet no significant differences were found between FES and CS. Frequency MMN was correlated with the MATRICS consensus cognitive battery (MCCB) combined score (r = -0.327, p < 0.05) and MCCB verbal learning (r = -0.328, p < 0.05) in FES. Evoked theta power was correlated with MCCB working memory in both FES (r = 0.347, p < 0.05) and CS (r = 0.408, p < 0.01).Conclusion: These findings suggest that duration MMN and evoked theta power deficits may be more sensitive for detection of schizophrenia during its early stages. Moreover, frequency MMN and theta power could potentially linked to poor cognitive functioning in schizophrenic patients. The findings mentioned above indicated that the neural mechanisms of the three indexes may vary between people
A Higher Dietary Inflammatory Index Score Is Associated With a Higher Risk of Breast Cancer Among Chinese Women: A Case–Control Study
Previous studies have investigated the association between dietary inflammatory potential and the development of cancer. For breast cancer the results have been equivocal. The present study aimed to investigate whether higher Dietary Inflammatory IndexTM (DII) scores were associated with increased risk of breast cancer among Chinese women. A total of 867 cases and 824 controls were recruited into the present case–control study from September 2011 to February 2016. DII scores were computed based on baseline dietary intake assessed by a validated 81-item FFQ. The OR and 95 % CI were assessed by multivariable logistic regression after adjusting for various potential confounders. DII scores in this study ranged from −5·87 (most anti-inflammatory score) to +5·71 (most proinflammatory score). A higher DII score was associated with a higher breast cancer risk (adjusted ORquartile 4 v. 1 2·28; 95 % CI 1·71, 3·03; adjusted ORcontinuous 1·40; 95 %CI 1·25, 1·39). In stratified analyses, positive associations also were observed except for underweight women or women with either oestrogen receptor+ or progesterone receptor+ status (but not both). Results from this study indicated that higher DII scores, corresponding to more proinflammatory diets, were positively associated with breast cancer risk among Chinese women
Disruption of the GABAergic system contributes to the development of perioperative neurocognitive disorders after anesthesia and surgery in aged mice
Aims:
Perioperative neurocognitive disorders (PND) are associated with cognitive impairment in the preoperative or postoperative period, and neuroinflammation is thought to be the most important mechanisms especially during the postoperative period. The GABAergic system is easily disrupted by neuroinflammation. This study investigated the impact of the GABAergic system on PND after anesthesia and surgery.
Methods:
An animal model of laparotomy with inhalation anesthesia in 16-month old mice was addressed. Effects of the GABAergic system were assessed using biochemical analysis. Pharmacological blocking of α5GABAARs or P38 mitogen-activated protein kinase (MAPK) was applied to investigate the effect of the GABAergic system.
Results:
After laparotomy, the hippocampus-dependent memory and long-term potentiation were impaired, the levels of IL-6, IL-1β and TNF-α upregulated in the hippocampus, the concentration of GABA decreased, and the protein levels of the surface α5GABAARs up-regulated. Pharmacological blocking of α5GABAARs with L655,708 alleviated laparotomy induced cognitive deficits. A further study found that the P38 MAPK signaling pathway was involved and pharmacological blocking with SB203,580 alleviated memory dysfunction.
Conclusions:
Anesthesia and surgery caused neuroinflammation in the hippocampus, which consequently disrupted the GABAergic system, increased the expressions of surface α5GABAARs especially through the P38 MAPK signaling pathway, and eventually led to hippocampus-dependent memory dysfunctions
INTERVENTION EFFECT AND DOSE-DEPENDENT RESPONSE OF TANREQING INJECTION ON AIRWAY MUCUS HYPERSECRETION IN LIPOPOLYSACCHARIDE-INDUCED RATS
Background: Tanreqing injection, a Chinese herbal formulation comprising Radix Scutellariae, Fructus Forsythiae, Flos Lonicerae, Antelope horn, and Bear bile powder, has been used to treat bronchitis and pneumonia for many years in China. However, its anti-mucus-hypersecretion mechanism has yet not been fully interpreted. We aim to assess the effect and dose-response relationships of Tanreqing injection on lipopolysacchaide (LPS) induced airway mucus hypersecretion in rats.
Material and methods: Forty-eight male rats were randomly divided into four groups (12 per group). A rat model of airway mucus hypersecretion was generated with LPS. Tanreqing injection was given by intratracheal instillation, and bronchoalveolar lavage fluid (BALF) from the right lung was collected. BALF total protein was determined by bicinchoninic acid disodium assay (BCA). Muc5ac was measured using enzyme linked immunosorbent assay (ELISA) and immunohistochemistry. The expression of muc5ac mRNA was detected by real-time polyermase chain reaction (RT-PCR). The middle lobe of the right lung was stained with alcian blue-periodic acid sthiff (AB-PAS) and positive staining relative shading area examined.
Results: LPS caused airway mucus hypersecretion, The LPS-induced airway mucus hypersecretion increased beginning at 24 hr, and peaked at 96 hr. Tanreqing injection could inhibit airway mucus hypersecretion, and suppress the expression of muc5ac mRNA.
Conclusion: Tanreqing injection inhibits airway mucus hypersecretion in a certain dose-dependent trend
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