84 research outputs found
Causal conditional hidden Markov model for multimodal traffic prediction
Multimodal traffic flow can reflect the health of the transportation system,
and its prediction is crucial to urban traffic management. Recent works
overemphasize spatio-temporal correlations of traffic flow, ignoring the
physical concepts that lead to the generation of observations and their causal
relationship. Spatio-temporal correlations are considered unstable under the
influence of different conditions, and spurious correlations may exist in
observations. In this paper, we analyze the physical concepts affecting the
generation of multimode traffic flow from the perspective of the observation
generation principle and propose a Causal Conditional Hidden Markov Model
(CCHMM) to predict multimodal traffic flow. In the latent variables inference
stage, a posterior network disentangles the causal representations of the
concepts of interest from conditional information and observations, and a
causal propagation module mines their causal relationship. In the data
generation stage, a prior network samples the causal latent variables from the
prior distribution and feeds them into the generator to generate multimodal
traffic flow. We use a mutually supervised training method for the prior and
posterior to enhance the identifiability of the model. Experiments on
real-world datasets show that CCHMM can effectively disentangle causal
representations of concepts of interest and identify causality, and accurately
predict multimodal traffic flow.Comment: 8 pages, 5 figure
Tetragonal Mexican-Hat Dispersion and Switchable Half-Metal State with Multiple Anisotropic Weyl Fermions in Penta-Graphene
In past decades, the ever-expanding library of 2D carbon allotropes has
yielded a broad range of exotic properties for the future carbon-based
electronics. However, the known allotropes are all intrinsic nonmagnetic due to
the paired valence electrons configuration. Based on the reported 2D carbon
structure database and first-principles calculations, herein we demonstrate
that inherent ferromagnetism can be obtained in the prominent allotrope,
penta-graphene, which has an unique Mexican-hat valence band edge, giving rise
to van Hove singularities and electronic instability. Induced by modest
hole-doping, being achievable in electrolyte gate, the semiconducting
pentagraphene can transform into different ferromagnetic half-metals with room
temperature stability and switchable spin directions. In particular, multiple
anisotropic Weyl states, including type-I and type-II Weyl cones and hybrid
quasi Weyl nodal loop, can be found in a sizable energy window of spin-down
half-metal under proper strains. These findings not only identify a promising
carbon allotrope to obtain the inherent magnetism for carbon-based spintronic
devices, but highlight the possibility to realize different Weyl states by
combining the electronic and mechanical means as well
Oral vinorelbine and continuous low doses of cyclophosphamide in pediatric rhabdomyosarcoma: a real-world study
Introduction: Metronomic maintenance therapy (MMT) has significantly improved the survival of patients with high-risk rhabdomyosarcoma in clinical trials. However, there remains a lack of relevant data on its effectiveness in real-world situations.Methods: We retrospectively retrieved data of 459 patients < 18 years of age diagnosed with rhabdomyosarcoma at Sun Yat-sen University Cancer Center from January 2011 to July 2020 from our database. The MMT regimen was oral vinorelbine 25–40 mg/m2 for twelve 4-week cycles on days 1, 8, and 15, and oral cyclophosphamide 25–50 mg/m2 daily for 48 consecutive weeks.Results: A total of 57 patients who underwent MMT were included in the analysis. The median follow-up time was 27.8 (range: 2.9–117.5) months. From MMT to the end of follow-up, the 3-year PFS and OS rates were 40.6% ± 6.8% and 58.3% ± 7.2%, respectively. The 3-year PFS was 43.6% ± 11.3% in patients who were initially diagnosed as low- and intermediate-risk but relapsed after comprehensive treatment (20/57), compared with 27.8% ± 10.4% in high-risk patients (20/57) and 52.8% ± 13.3% in intermediate-risk patients who did not relapse (17/57). The corresponding 3-year OS for these three groups was 65.8% ± 11.4%, 50.1% ± 12.9%, and 55.6% ± 13.6%, respectively.Conclusion: We present a novel study of MMT with oral vinorelbine and continuous low doses of cyclophosphamide in real-world pediatric patients with RMS. Our findings showed that the MMT strategy significantly improved patient outcomes and may be an effective treatment for high-risk and relapsed patients
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Research Progress in Pre-harvest Sprouting of Rice
Pre-harvest sprouting is a serious problem in global agricultural production. After a long period of domestication, the dormancy level of cultivated crops is generally lower than that of wild ancestors. Although the shortening of dormancy period may increase the reproductive generation and agricultural production value of crops, premature dormancy release will cause crop sprouting before harvest, resulting in huge economic losses. In this paper, the physiological mechanism, QTL and genes, prevention and control of pre-harvest sprouting are systematically reviewed. It is believed that high water content is the precondition of rice seed germination and pre-harvest sprouting, during this process, the increases of amylase activity and soluble sugar content provide energy for pre-harvest sprouting; the contents of plant hormones ABA and GA in rice grains and the sensitivity of seeds to them are the key factors to determine the pre-harvest germination. In recent years, the excavation of QTL and its functional genes related to pre-harvest sprouting will provide an important basis for clarifying the mechanism of pre-harvest sprouting in rice and breeding resistant varieties. In the long run, through extensive evaluation of rice germplasm resources, especially searching for the lost dormancy genes in wild rice and local varieties, and gathering such genes through molecular breeding, breeding lines (varieties) resistant to sprouting, it is of great significance to solve the problem of sprouting, improve rice yield and quality, and ensure national food security
What Conditions, in Combination, Drive Inter-Organizational Activities? Evidence from Cooperation on Environmental Governance in Nine Urban Agglomerations in China
This study investigates what conditions, in combination, drive varying levels of intensity of inter-organizational activities regarding cooperation on environmental governance in nine urban agglomerations in China. This article distinguishes strong and weak inter-organizational activities; and through a literature review, the article distills five conditions influencing inter-organizational activity, including vertical meta-governance, horizontal meta-governance, leadership, autonomous capacity disparity and environmental status disparity. While these conditions are clearly unique, it is unclear if any of these conditions are necessary or sufficient and how they work collectively, for varying degrees of inter-organization activities. Through the method of Qualitative Comparative Analysis (QCA), the article examines this question. The findings suggest that strong horizontal meta-governance and strong leadership are both necessary conditions for strong inter-organizational involvement in joint environmental governance. Small disparities in autonomous capacity and environmental status are sufficient conditions for strong inter-organizational activities. Strong vertical meta-governance is neither a necessary nor a sufficient condition. The QCA results reveal that local authorities should put energy in developing their formal structures favorable for cooperation and that local leaders should develop skills to facilitate joint actions between member cities in an agglomeration
A novel modified paclitaxel-loaded discoidal recombinant high-density lipoproteins: Preparation, characterizations and in vivo evaluation
AbstractThis study is one of the first to focus on the unexpected drug leakage from discoidal recombinant high-density lipoproteins (d-rHDLs) as a consequence of remodeling process, mainly associated with lecithin-cholesterol acyltransferase (LCAT) during their metabolic process. Here, a newly monocholesterylsuccinate (CHS) modified paclitaxel-loaded d-rHDLs (cP-d-rHDLs) were constructed successfully through structural modification, thus aiming to improve the performance of d-rHDLs. And next their in vitro physiochemical properties and pharmacokinetics in Sprague–Dawley rats were elaborately investigated. Collectively our studies demonstrated that cP-d-rHDLs, whose remodeling behaviors were restrained effectively after structural modification, exhibited more excellent and promising properties as novel delivery vehicles for anti-cancer agents
Path Planning Strategy for a Manipulator Based on a Heuristically Constructed Network
Collision-free path planning of manipulators is becoming indispensable for space exploration and on-orbit operation. Manipulators in these scenarios are restrained in terms of computing resources and storage, so the path planning method used in such tasks is usually limited in its operating time and the amount of data transmission. In this paper, a heuristically constructed network (HCN) construction strategy is proposed. The HCN construction contains three steps: determining the number of hub configurations and selecting and connecting hub configurations. Considering the connection time and connectivity of HCN, the number of hub configurations is determined first. The selection of hub configurations includes the division of work space and the optimization of the hub configurations. The work space can be divided by considering comprehensively the similarity among the various configurations within the same region, the dissimilarity among all regions, and the correlation among adjacent regions. The hub configurations can be selected by establishing and solving the optimization model. Finally, these hub configurations are connected to obtain the HCN. The simulation indicates that the path points number and the planning time is decreased by 45.5% and 48.4%, respectively, which verify the correctness and effectiveness of the proposed path planning strategy based on the HCN
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