Large Trajectory Models are Scalable Motion Predictors and Planners

Motion prediction and planning are vital tasks in autonomous driving, and recent efforts have shifted to machine learning-based approaches. The challenges include understanding diverse road topologies, reasoning traffic dynamics over a long time horizon, interpreting heterogeneous behaviors, and generating policies in a large continuous state space. Inspired by the success of large language models in addressing similar complexities through model scaling, we introduce a scalable trajectory model called State Transformer (STR). STR reformulates the motion prediction and motion planning problems by arranging observations, states, and actions into one unified sequence modeling task. With a simple model design, STR consistently outperforms baseline approaches in both problems. Remarkably, experimental results reveal that large trajectory models (LTMs), such as STR, adhere to the scaling laws by presenting outstanding adaptability and learning efficiency. Qualitative results further demonstrate that LTMs are capable of making plausible predictions in scenarios that diverge significantly from the training data distribution. LTMs also learn to make complex reasonings for long-term planning, without explicit loss designs or costly high-level annotations

Global research trends of Mycoplasma pneumoniae pneumonia in children: a bibliometric analysis

BackgroundMycoplasma pneumoniae pneumonia (MPP), attributable to Mycoplasma pneumoniae (MP), represents a predominant form of community-acquired pneumonia in pediatric populations, thereby posing a significant threat to pediatric health. Given the burgeoning volume of research literature associated with pediatric MPP in recent years, it becomes imperative to undertake a bibliometric analysis aimed at delineating the current research landscape and emerging trends, thereby furnishing a framework for subsequent investigations.MethodsA comprehensive literature search targeting pediatric MPP was conducted in the Web of Science Core Collection. After the removal of duplicate entries through Endnote software, the remaining articles were subject to scientometric analysis via Citespace software, VOSviewer software and R language, focusing on variables such as publication volume, contributing nations, institutions and authors, references and keywords.ResultsA total of 1,729 articles pertinent to pediatric MPP were included in the analysis. China and the United States emerged as the nations with the highest publication output. Italian scholar Susanna Esposito and Japanese scholar Kazunobu Ouchi were the most influential authors in the domain of pediatric MPP. Highly-cited articles primarily focused on the epidemiological investigation of pediatric MPP, the clinical characteristics and treatment of macrolide-resistant MPP, and biomarkers for refractory Mycoplasma pneumoniae pneumonia (RMPP). From the corpus of 1,729 articles, 636 keywords were extracted and categorized into ten clusters: Cluster #0 centered on molecular-level typing of macrolide-resistant strains; Cluster #1 focused on lower respiratory tract co-infections; Clusters #2 and #6 emphasized other respiratory ailments caused by MP; Cluster #3 involved biomarkers and treatment of RMPP; Clusters #4 and #9 pertained to extrapulmonary complications of MPP, Clusters #5 and #7 addressed etiological diagnosis of MPP, and Cluster #8 explored pathogenic mechanisms.ConclusionsThe past few years have witnessed extensive attention directed towards pediatric MPP. Research in pediatric MPP principally revolves around diagnostic techniques for MP, macrolide resistance, complications of MPP, treatment and diagnosis of RMPP, and elucidation of pathogenic mechanisms. The present study provides pediatric clinicians and researchers with the research status and focal points in this field, thereby guiding the orientation of future research endeavors

Expression profiles of human somatic mesenchymal stem cells derived from fresh endometrium, ectopic-endometrium and umbilical cord

Objectives: The study investigated the stem cell expression profiles and differentiation capacities of mesenchymal stem cells (MSCs) from different tissues, specifically human eutopic endometrium MSCs (eut-MSCs), ectopic endometrium MSCs (ect-MSCs), and umbilical cord MSCs (UC-MSCs). Our aim was to identify any similarities in subpopulations among these MSCs and lay a foundation for MSCs repair.Material and methods: MSCs were isolated from endometrial tissue (n = 5), endometriosis tissue (n = 6), and umbilical cords (n = 7). Flow cytometry was used to examine cell phenotype, and three lineage tests were conducted to evaluate the differentiation capacity of the MSCs.Results: Eut-MSCs expressed CD44 (98.00 ± 0.96%), CD73 (99.54 ± 0.02%), CD140b (99.16 ± 0.50%), CD146 (93.87 ± 2.27%), SUSD2 (50.76 ± 8.15%), and CD271 (2.1 ± 1.22%). Ect-MSCs expressed CD44 (98.23 ± 1.60%), CD73 (99.63 ± 0.04%), CD140b (98.13 ± 0.53%), CD146 (93.88 ± 3.19%), SUSD2 (49.33 ± 6.36%), and CD271 (2.85 ± 1.17%). UC-MSCs expressed CD44 (99.11 ± ± 0.42%), CD73 (99.65 ± 0.12%), CD140b (99.84 ± 0.42%), CD146 (88.09 ± 4.20%), SUSD2 (72.87 ± 7.13%), and CD271 (6.19 ± 2.08%). The expression of SUSD2 and CD271 in UC-MSCs was slightly but not significantly higher than that in ect-MSCs and eut-MSCs. However, CD44, CD73, CD140b, and CD146 showed similar expression levels in UC-MSCs, ect-MSCs, and eut-MSCs. All three types of MSCs demonstrated the capacity to differentiate into osteoblasts, adipocytes, and chondrocytes.Conclusions: Our findings indicate that ect-MSCs, eut-MSCs, and UC-MSCs have similar stem cell phenotypes and the ability to differentiate into three lineages

Binding mechanism of arsenate on rutile (110) and (001) planes studied using grazing-incidence EXAFS measurement and DFT calculation

Characterization of contaminant molecules on different exposed crystal planes is required to conclusively describe its behavior on mineral surfaces. Here, the structural properties and relative stability of arsenate adsorbed on rutile TiO2 (110) and (001) surfaces were investigated using grazing-incidence extended X-ray absorption fine structure (GI-EXAFS) spectra and periodic density functional theory (DFT) calculation. The combined results indicated that arsenate mainly formed inner-sphere bidentate binuclear (BB) and monodentate mononuclear (MM) complexes on both surfaces, but the orientational polar angles of arsenate on the (110) surface were commonly smaller than that on the (001) surface for the two adsorption modes. The DFT calculation showed that the (110) plane had a higher affinity toward arsenate than the (001) plane, suggesting that, for a given adsorption mode (i.e., MM or BB structure), a small polar angle was more favorable for arsenate stabilized on the rutile surfaces

Numerical simulation study on the effect of temperature on the restricted diffusion in porous media

It is of great significance to study how temperature affects the restricted diffusion in pores for an accurate evaluation of reservoir physical properties by using nuclear magnetic resonance (NMR) diffusion-transverse relaxation (D-T2) spectrum under reservoir temperature conditions. In this paper, we simulate the restricted diffusion and two-dimensional (2D) NMR D-T2 spectra of water molecules at different temperatures using random-walk method. The one-dimensional (1D) restricted diffusion simulation results show that the diffusion coefficient in the pore at room temperature decays with the diffusion time and eventually reaches a plateau. Under the condition of long-time diffusion, the ratio of restricted diffusion coefficient to bulk diffusion coefficient at different temperatures tends to be the same constant. With the increase in temperature, the simulated D-T2 spectra also gradually move upward. The simulated D-T2 spectra at all temperatures are consistent with the Padé interpolation equation. In addition, the results calculated by Padé interpolation equation demonstrate that the degree of temperature influence on the D-T2 spectrum of rock is quantitatively related to the pore radius, porosity and cementation index

The clonal growth in Aconitum carmichaelii Debx

Aconitum carmichaelii Debx. is used as traditional herbal medicine in China, Japan, and other Asian countries. A. carmichaelii has two modes for reproduction: sexual reproduction with seed and vegetative reproduction with vegetative propagules. The vegetative propagules are belowground and invisible. To date, only a handful of studies for the clonal growth are available. In this study, we investigated the clonal growth by anatomical and morphological changes. Results revealed that the axillary bud appeared on the rhizome. Furthermore, the axillary meristem in the axillary bud differentiated a bud upwards and an adventitious root (AR) downwards. The AR expanded to a tuberous root in order to provide the bud nutrients for the new plant. The AR branched LRs. In addition, some lateral roots (LRs) on the AR also swelled. Both the AR and LR were found to follow a similar pattern of development. However, high lignification in the stele region of LRs inhibited further expansion. AR development was attributed to activities of the cambium and meristem cell, starch accumulation, stele lignification, and a polyarch stele. Our study not only provides a better understanding of clonal growth but also provides clues to explore the regulatory mechanisms underlying AR development in A. carmichaelii

Experimental study on the mechanism of enhancing oil recovery by polymer – surfactant binary flooding

Aiming at the development situation of the Xinjiang oil field, the mechanism of enhancing oil recovery by the Polymer-Surfactant Binary Flooding (SP Flooding) was studied through SP Flooding sand pack, natural core and micro model experiments, and Optimum SP Flooding formula is provided. The results show that the enhanced oil recovery by the SP Flooding increases with the increase of the viscosity ratio between water and oil or the decrease of the interfacial tension. Capillary displacement ratio can reflect the synergetic effect of viscosity and interfacial tension and help screen out the optimum formula of the SP Flooding. For Qizhong block in Xinjiang Oilfield, where the critical viscosity ratio of SP flooding solution is 2.5, the order of magnitude of the critical interfacial tension is 1×10−2 mN/m, and the order of magnitude of the critical capillary displacement ratio is 1×10−3, the optimum formula of the SP Flooding composed of 0.3% KPS-1+1 115 mg/L HPAM can enhance the oil recovery by 23.96%. The polymer in the SP Flooding system increases the viscosity of the displacement fluid, accordingly the fluidity of the aqueous phase reduces and that of the oil phase increases, and the resulting decrease of the mobility ratio can control waterflood fingering, make water absorption thickness increase, enhance sweep efficiency and thus activate the residual oil trapped in dead ends. The surfactant decreases interfacial tension, and the resulting decrease of adhesion work makes residual oil emulsified, stripped, wiredrawn and easy to move. In addition, the emulsion liquid further increases the viscosity of the aqueous phase, and with interaction of lower interfacial tension and high viscosity of the emulsion liquid, the capillary displacement ratio is greatly enhanced, which in turn improves the oil displacement efficiency by displacing isolated-island, columnar and membranous residual oil, and consequently a higher oil recovery. Key words: polymer, surfactant, binary flooding, enhanced oil recovery, viscosity ratio, interfacial tension, capillary displacement rati

A New Method and Circuit of Ringing Suppression for Low-field NMR Instruments

Accelerating the release of the antenna residual energy to weaken the antenna ringing signal is beneficial to shorten the echo time (TE) of low-field nuclear magnetic resonance (NMR) instruments, thus improving the measurement resolution and signal-to-noise ratio (SNR) of fast relaxation components. The antenna Q value has an opposite effect on the energy emission efficiency and discharge speed. For this reason, we first designed a new Q-switch circuit, which can greatly shorten the energy discharge time while ensuring the transmission efficiency. On this basis, an optimized pulse sequence was applied to overcome the defect that traditional phase alternated pair stacking (PAPs) cannot eliminate 90° pulse ringing, and the SNR was further improved by the method of phase cycling. Finally, the new Q-switch circuit was tested on a 2 MHz core analyzer, the Q value of the antenna was reduced to about 1/5 of the transmit period, and the antenna recovery time was reduced from 280.0 μs to 18.2 μs. Moreover, with the new Q-switch circuit and optimized pulse sequence, the T2 signal of the fast relaxation component can be effectively obtained when TE=60 μs

Morphological and anatomical changes during dormancy break of the seeds of Fritillaria taipaiensis

Fritillaria taipaiensis P. Y. Li is the most suitable species planted at low altitudes among other species used as Tendrilleaf Fritillary Bulb, whose seeds embracing the morphological and physiological dormancy need to experience a long-dormant time from sowing to germination. In this study, the developmental changes of F. taipaiensis seeds during dormancy period were observed by morphological and anatomical observation, and the cause of long-term dormancy of seeds was discussed from the perspective of embryonic development. The process of embryonic organogenesis was revealed during the dormancy stage by the paraffin section. The effects of testa, endosperm and temperature on dormant seeds were discussed. Furthermore, we found that the mainly dormant reason was caused by the morphological dormancy, which accounted for 86% of seed development time. The differentiation time of the globular or pear-shaped embryo into a short-rod embryo was longer, which was one of the chief reasons for the morphological dormancy and played an important role in embryonic formation. Testa and endosperm with mechanical constraint and inhibitors involved in the dormancy of F. taipaiensis seeds. The seeds of F. taipaiensis, the average ambient temperature of 6–12°C for morphological dormancy and 11–22°C for physiological dormancy, were unsuitable for seed growth. Therefore, we suggested that the dormancy time of F. taipaiensis seeds could be shortened by shortening the development time of the proembryo stage and stratification for the different stages of dormancy

Identification of antagonistic fungi and their antifungal activities against aconite root rot pathogens

Root rot is one of the main diseases affecting Aconitum carmichaelii Debx. during cultivation, seriously limiting yields of this herb. Currently, there is no effective control measure for aconite root rot. The antifungal activities of antagonistic strains against aconite root rot pathogens (Fusarium proliferatum, Fusarium solani, and Fusarium oxysporum) were investigated in this study. Three antagonistic strains, JKT7, JKT28 and JKT39, were screened and identified as Trichoderma asperellum, Trichoderma hamatum and Trichoderma virens, respectively. Dual culture tests showed that the inhibition rates of the three Trichoderma strains on the pathogens were all approximately 70%. The volatile metabolites had inhibitory effects on the mycelial growth of pathogens, while the nonvolatile metabolites in the culture filtrates did not show significant inhibitory effects. The volatile components analyzed by GC‒MS were mainly ketones, esters, and alcohols. These results indicate that these strains of Trichoderma and their secondary metabolites have antimicrobial activities against the pathogens of aconite root rot. This study could provide a scientific basis for the biocontrol of aconite root rot