89 research outputs found
Multi-User Matching and Resource Allocation in Vision Aided Communications
Visual perception is an effective way to obtain the spatial characteristics
of wireless channels and to reduce the overhead for communications system. A
critical problem for the visual assistance is that the communications system
needs to match the radio signal with the visual information of the
corresponding user, i.e., to identify the visual user that corresponds to the
target radio signal from all the environmental objects. In this paper, we
propose a user matching method for environment with a variable number of
objects. Specifically, we apply 3D detection to extract all the environmental
objects from the images taken by multiple cameras. Then, we design a deep
neural network (DNN) to estimate the location distribution of users by the
images and beam pairs at multiple moments, and thereby identify the users from
all the extracted environmental objects. Moreover, we present a resource
allocation method based on the taken images to reduce the time and spectrum
overhead compared to traditional resource allocation methods. Simulation
results show that the proposed user matching method outperforms the existing
methods, and the proposed resource allocation method can achieve
transmission rate of the traditional resource allocation method but with the
time and spectrum overhead significantly reduced.Comment: 34 pages, 21 figure
Multi-Camera View Based Proactive BS Selection and Beam Switching for V2X
Due to the short wavelength and large attenuation of millimeter-wave
(mmWave), mmWave BSs are densely distributed and require beamforming with high
directivity. When the user moves out of the coverage of the current BS or is
severely blocked, the mmWave BS must be switched to ensure the communication
quality. In this paper, we proposed a multi-camera view based proactive BS
selection and beam switching that can predict the optimal BS of the user in the
future frame and switch the corresponding beam pair. Specifically, we extract
the features of multi-camera view images and a small part of channel state
information (CSI) in historical frames, and dynamically adjust the weight of
each modality feature. Then we design a multi-task learning module to guide the
network to better understand the main task, thereby enhancing the accuracy and
the robustness of BS selection and beam switching. Using the outputs of all
tasks, a prior knowledge based fine tuning network is designed to further
increase the BS switching accuracy. After the optimal BS is obtained, a beam
pair switching network is proposed to directly predict the optimal beam pair of
the corresponding BS. Simulation results in an outdoor intersection environment
show the superior performance of our proposed solution under several metrics
such as predicting accuracy, achievable rate, harmonic mean of precision and
recall
Prokineticin 2 Is a Target Gene of Proneural Basic Helix-Loop-Helix Factors for Olfactory Bulb Neurogenesis
Prokineticin 2, a cysteine-rich secreted protein, regulates diverse biological functions including the neurogenesis of olfactory bulb. Here we show that the PK2 gene is a functional target gene of proneural basic helix-loop-helix (bHLH) factors. Neurogenin 1 and MASH1 activate PK2 transcription by binding to E-box motifs on the PK2 promoter with the same set of E-boxes critical for another pair of bHLH factors, CLOCK and BMAL1, in the regulation of circadian clock. Our results establish PK2 as a common functional target gene for different bHLH transcriptional factors in mediating their respective functions
Long term in vitro expansion of epithelial stem cells enabled by pharmacological inhibition of PAK1-ROCK-Myosin II and TGF-β signaling
Summary: Despite substantial self-renewal capability in vivo, epithelial stem and progenitor cells located in various tissues expand for a few passages in vitro in feeder-free condition before they succumb to growth arrest. Here, we describe the EpiX method, which utilizes small molecules that inhibit PAK1-ROCK-Myosin II and TGF-β signaling to achieve over one trillion-fold expansion of human epithelial stem and progenitor cells from skin, airway, mammary, and prostate glands in the absence of feeder cells. Transcriptomic and epigenomic studies show that this condition helps epithelial cells to overcome stresses for continuous proliferation. EpiX-expanded basal epithelial cells differentiate into mature epithelial cells consistent with their tissue origins. Whole-genome sequencing reveals that the cells retain remarkable genome integrity after extensive in vitro expansion without acquiring tumorigenicity. EpiX technology provides a solution to exploit the potential of tissue-resident epithelial stem and progenitor cells for regenerative medicine. : Zhang et al. screen a small-molecule collection and find that pharmacologic inhibition of TGF-β and PAK1-ROCK-Myosin II, in low calcium conditions, supports extended expansion of epithelial stem cells in 2D format. This approach enhances the potential of tissue-resident epithelial stem cells for cell therapy. Keywords: epithelial stem and progenitor cells, cell culture method, TGF-β, PAK1/ROCK/Myosin II, feeder-free, regenerative medicine, cell therap
Overexpression of Prokineticin 2 in Transgenic Mice Leads to Reduced Circadian Behavioral Rhythmicity and Altered Molecular Rhythms in the Suprachiasmatic Clock
In mammals, the master pacemaker driving circadian rhythms is thought to reside in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus. A clear view of molecular clock mechanisms within the SCN neurons has been elucidated. In contrast, much less is known about the output mechanism by which the SCN circadian pacemaker sends timing information for eventual control of physiological and behavioral rhythms. Two secreted molecules, prokineticin 2 (PK2) and vasopressin, that are encoded by respective clock-controlled genes, have been indicated as candidate SCN output molecules. Several lines of evidence have emerged that support the role of PK2 as an output signal for the SCN circadian clock, including the reduced circadian rhythms in mice that are deficient in PK2 or its receptor, PKR2. In the current study, transgenic mice with the overexpression of PK2 have been generated. These transgenic mice displayed reduced oscillation of the PK2 expression in the SCN and decreased amplitude of circadian locomotor rhythm, supporting the important signaling role of PK2 in the regulation of circadian rhythms. Altered molecular rhythms were also observed in the SCN in the transgenic mice, indicating that PK2 signaling also regulates the operation of core clockwork. This conclusion is consistent with recent reports showing the likely signaling role of PK2 from the intrinsically photosensitive retinal ganglion cells to SCN neurons. Thus, PK2 signaling plays roles in both the input and the output pathways of the SCN circadian clock
Self-assembling surfactant-like peptide A6K as potential delivery system for hydrophobic drugs
5G PRS-Based Sensing: A Sensing Reference Signal Approach for Joint Sensing and Communication System
The emerging joint sensing and communication (JSC) technology is expected to
support new applications and services, such as autonomous driving and extended
reality (XR), in the future wireless communication systems. Pilot (or
reference) signals in wireless communications usually have good passive
detection performance, strong anti-noise capability and good auto-correlation
characteristics, hence they bear the potential for applying in radar sensing.
In this paper, we investigate how to apply the positioning reference signal
(PRS) of the 5th generation (5G) mobile communications in radar sensing. This
approach has the unique benefit of compatibility with the most advanced mobile
communication system available so far. Thus, the PRS can be regarded as a
sensing reference signal to simultaneously realize the functions of radar
sensing, communication and positioning in a convenient manner. Firstly, we
propose a PRS based radar sensing scheme and analyze its range and velocity
estimation performance, based on which we propose a method that improves the
accuracy of velocity estimation by using multiple frames. Furthermore, the
Cramer-Rao lower bound (CRLB) of the range and velocity estimation for PRS
based radar sensing and the CRLB of the range estimation for PRS based
positioning are derived. Our analysis and simulation results demonstrate the
feasibility and superiority of PRS over other pilot signals in radar sensing.
Finally, some suggestions for the future 5G-Advanced and 6th generation (6G)
frame structure design containing the sensing reference signal are derived
based on our study
Impaired pain sensation in mice lacking prokineticin 2
Prokineticins (PKs), consisting of PK1 and PK2, are a pair of newly identified regulatory peptides. Two closely related G-protein coupled receptors, PKR1 and PKR2, mediate the signaling of PKs. PKs/PKRs participate in the regulation of diverse biological processes, ranging from development to adult physiology. A number of studies have indicated the involvement of PKs/PKRs in nociception. Here we show that PK2 is a sensitizer for nociception. Intraplantar injection of recombinant PK2 resulted in a strong and localized hyperalgesia with reduced thresholds to nociceptive stimuli. PK2 mobilizes calcium in dissociated dorsal root ganglion (DRG) neurons. Mice lacking the PK2 gene displayed strong reduction in nociception induced by thermal and chemical stimuli, including capsaicin. However, PK2 mutant mice showed no difference in inflammatory response to capsaicin. As the majority of PK2-responsive DRG neurons also expressed transient receptor potential vanilloid (TRPV1) and exhibited sensitivity to capsaicin, TRPV1 is likely a significant downstream molecule of PK2 signaling. Taken together, these results reveal that PK2 sensitize nociception without affecting inflammation
The Effect of Self-Assembling Peptide RADA16-I on the Growth of Human Leukemia Cells in Vitro and in Nude Mice
Nanofiber scaffolds formed by self-assembling peptide RADA16-I have been used for the study of cell proliferation to mimic an extracellular matrix. In this study, we investigated the effect of RADA16-I on the growth of human leukemia cells in vitro and in nude mice. Self-assembly assessment showed that RADA16-I molecules have excellent self-assembling ability to form stable nanofibers. MTT assay displayed that RADA16-I has no cytotoxicity for leukemia cells and human umbilical vein endothelial cells (HUVECs) in vitro. However, RADA16-I inhibited the growth of K562 tumors in nude mice. Furthermore, we found RADA16-I inhibited vascular tube-formation by HUVECs in vitro. Our data suggested that nanofiber scaffolds formed by RADA16-I could change tumor microenvironments, and inhibit the growth of tumors. The study helps to encourage further design of self-assembling systems for cancer therapy.China. Ministry of Education (project 985
Signaling Role of Prokineticin 2 on the Estrous Cycle of Female Mice
The possible signaling role of prokineticin 2 (PK2) and its receptor, prokineticin receptor 2 (PKR2), on female reproduction was investigated. First, the expression of PKR2 and its co-localization with estrogen receptor (ERα) in the hypothalamus was examined. Sexually dimorphic expression of PKR2 in the preoptic area of the hypothalamus was observed. Compared to the male mice, there was more widespread PKR2 expression in the preoptic area of the hypothalamus in the female mice. The likely co-expression of PKR2 and ERα in the preoptic area of the hypothalamus was observed. The estrous cycles in female PK2-null, and PKR2-null heterozygous mice, as well as in PK2-null and PKR2-null compound heterozygous mice were examined. Loss of one copy of PK2 or PKR2 gene caused elongated and irregular estrous cycle in the female mice. The alterations in the estrous cycle were more pronounced in PK2-null and PKR2-null compound heterozygous mice. Consistent with these observations, administration of a small molecule PK2 receptor antagonist led to temporary blocking of estrous cycle at the proestrous phase in female mice. The administration of PKR2 antagonist was found to blunt the circulating LH levels. Taken together, these studies indicate PK2 signaling is required for the maintenance of normal female estrous cycles
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