313 research outputs found
Activity and expression of ADP-glucose pyrophosphorylase during rhizome formation in lotus (Nelumbo nucifera Gaertn.)
Additional file 7: Figure S6. Comparison of NnAGPS against AGPS of other species
SCMA codebooks design for Rayleigh fading channel
According to the symbol error eate (SER) of the superimposed constellation, the near-optimal space code multiple access (SCMA) codebooks were explored under uplink and downlink Rayleigh fading channels, respectively.A near-optimal codebook design scheme was proposed based on the mathematical model between the superimposed constellation and the SER formula.And the proposed design procedures could be summarized as follows, design the factor graph matrix, match the best codeword pair, and find the optimal angle.Numerical results are provided to demonstrate that the proposed scheme can achieve near-optimal SER performance
Low error floor LT coding algorithm by using fixed-length node classification window
To solve the problem of high error floor for LT codes in additive white Gaussian noise (AWGN) channels, an improved coding scheme was designed.A fixed-length classification window was used to sort out the information nodes with relatively small degrees.Then these nodes would be forced to participate in the coding process frequently, so that they could obtain sufficiently high reliability.To design the optimal parameters, firstly, the bit error rate (BER) performance of LT codes and the cause of the error floor were analyzed, and the theoretical BER lower bound was introduced as the first constraint.Secondly, the extrinsic information gain loss ratio (GLR) was designed to measure the convergence behavior of the improved LT code, and maximizing the GLR was denoted as the second constraint.Finally, the influence of different parameters on algorithm efficiency and coding complexity were analyzed, and the principle of priority selection of parameters was pointed out as the third constraint.The simulation results show that compared with the conventional LT code, the proposed algorithm can reduce the error floor by nearly three orders of magnitude.Besides, the designed LT code outperforms the existing LT codes in literature in terms of bit error rate (BER) performance
WebArena: A Realistic Web Environment for Building Autonomous Agents
With advances in generative AI, there is now potential for autonomous agents
to manage daily tasks via natural language commands. However, current agents
are primarily created and tested in simplified synthetic environments, leading
to a disconnect with real-world scenarios. In this paper, we build an
environment for language-guided agents that is highly realistic and
reproducible. Specifically, we focus on agents that perform tasks on the web,
and create an environment with fully functional websites from four common
domains: e-commerce, social forum discussions, collaborative software
development, and content management. Our environment is enriched with tools
(e.g., a map) and external knowledge bases (e.g., user manuals) to encourage
human-like task-solving. Building upon our environment, we release a set of
benchmark tasks focusing on evaluating the functional correctness of task
completions. The tasks in our benchmark are diverse, long-horizon, and designed
to emulate tasks that humans routinely perform on the internet. We experiment
with several baseline agents, integrating recent techniques such as reasoning
before acting. The results demonstrate that solving complex tasks is
challenging: our best GPT-4-based agent only achieves an end-to-end task
success rate of 14.41%, significantly lower than the human performance of
78.24%. These results highlight the need for further development of robust
agents, that current state-of-the-art large language models are far from
perfect performance in these real-life tasks, and that WebArena can be used to
measure such progress.Comment: Our code, data, environment reproduction resources, and video
demonstrations are publicly available at https://webarena.dev
Establishing a risk stratification model to identify clinically high-risk N0 breast cancer who could benefit from regional nodal irradiation: a single institute analysis
BackgroundThe purpose of this real-world study was to investigate the risk factors for developing recurrence among patients with pathological T1-3N0 breast cancer (BC) treated with breast-conserving surgery (BCS) followed by whole breast irradiation alone (WBI) and identify those clinically high-risk BCs who could benefit from regional nodal irradiation (RNI).Materials and methodsFemale BC patients treated at Shanghai Ruijin hospital from 2009 to 2016 were retrospectively reviewed. The disease-free survival (DFS), breast cancer specific survival (BCSS) and overall survival (OS) were estimated by the Kaplan-Meier method, and survival differences were compared with the log-rank test. Univariate and multivariate analysis was performed using Cox proportional hazards regression analysis. An external validation was conducted by using SEER database.ResultsA total of 622 BC patients treated with BCS+WBI alone were included. With a median follow-up of 82 months, the 7-year OS, BCSS and DFS for the entire cohort was 97%, 99% and 91%, respectively. Multivariable Cox analysis indicated that tumor size (p=0.006), tumor location (p=0.033), lymphovascular invasion (LVI) status (p=0.0028) and Ki-67 index (p=0.051) were independent risk factors for DFS. A scoring system was developed using these four factors and the 7-year DFS and OS were 97% and 96% for patients with 0-1 risk factors, 95% and 82% for patients with ≥2 risk factors (p<0.0001 for DFS, and p=0.0063 for OS). Based on tumor size and tumor location, an external validation by demonstrated that the 7-year OS was 90% and 88% for patients with 0-1 risk factor, which was significantly better than those defined as high-risk BC patients (82%, p<0.0001).ConclusionBy using our institute database, we establish a risk stratification system for identifying sub-group of pN0 BC patients, who are at high risk for developing recurrence. The results of our study support tailored RT decision-making according to individual risks, which needed to be confirmed in further studies
OSWorld: Benchmarking Multimodal Agents for Open-Ended Tasks in Real Computer Environments
Autonomous agents that accomplish complex computer tasks with minimal human
interventions have the potential to transform human-computer interaction,
significantly enhancing accessibility and productivity. However, existing
benchmarks either lack an interactive environment or are limited to
environments specific to certain applications or domains, failing to reflect
the diverse and complex nature of real-world computer use, thereby limiting the
scope of tasks and agent scalability. To address this issue, we introduce
OSWorld, the first-of-its-kind scalable, real computer environment for
multimodal agents, supporting task setup, execution-based evaluation, and
interactive learning across various operating systems such as Ubuntu, Windows,
and macOS. OSWorld can serve as a unified, integrated computer environment for
assessing open-ended computer tasks that involve arbitrary applications.
Building upon OSWorld, we create a benchmark of 369 computer tasks involving
real web and desktop apps in open domains, OS file I/O, and workflows spanning
multiple applications. Each task example is derived from real-world computer
use cases and includes a detailed initial state setup configuration and a
custom execution-based evaluation script for reliable, reproducible evaluation.
Extensive evaluation of state-of-the-art LLM/VLM-based agents on OSWorld
reveals significant deficiencies in their ability to serve as computer
assistants. While humans can accomplish over 72.36% of the tasks, the best
model achieves only 12.24% success, primarily struggling with GUI grounding and
operational knowledge. Comprehensive analysis using OSWorld provides valuable
insights for developing multimodal generalist agents that were not possible
with previous benchmarks. Our code, environment, baseline models, and data are
publicly available at https://os-world.github.io.Comment: 51 pages, 21 figure
Pollution status and distribution characteristics of indoor air bacteria in subway stations and compartments in a city of Central South China
BackgroundBacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. ObjectiveTo understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. MethodsThree subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO2), fine particulate matter (PM2.5), and inhalable particulate matter (PM10) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min−1, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO2 concentration and total bacterial count. ResultsThe pass rates were 100.0% for airborne total bacteria count, PM2.5, and PM10 in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO2, but 0% for humidity. The overall median (P25, P75) total bacteria count was 177 (138,262) CFU·m−3. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. ConclusionThe total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Visible photoluminescence from plasma-synthesized Si O2-buffered Si Nx films : Effect of film thickness and annealing temperature
The effect of the film thickness and postannealing temperature on visible photoluminescence (PL) from Si Nx films synthesized by plasma-assisted radio frequency magnetron sputtering on Si O2 buffer layers is investigated. It is shown that strong visible PL is achieved at annealing temperatures above 650 °C. The optimum annealing temperature for the maximum PL yield strongly depends on the film thickness and varies from 800 to 1200°C. A comparative composition-structure-property analysis reveals that the PL intensity is directly related to the content of the Si-O and Si-N bonds in the Si Nx films. Therefore, sufficient oxidation and moderate nitridation of Si Nx Si O2 films during the plasma-based growth process are crucial for a strong PL yield. Excessively high annealing temperatures lead to weakened Si-N bonds in thinner Si Nx films, which eventually results in a lower PL intensity
Drought Variation Characteristics and Effects on Vegetation Productivity in Gansu, Northwest China
Abstract
Changes in vegetation productivity (GPP) have an important impact on the global carbon cycle. Gansu is located in the arid and semi-arid region in northwest China, and its ecological environment is fragile. The study of the impact of drought on GPP is of great significance to the global ecosystem carbon cycle. Based on the SPEI index in Gansu from 2000 to 2020, this paper analyzed the changing characteristics of drought and its impact on GPP. The results revealed that: (1) In the past 21 years, the annual SPEI-12 has been increasing at a rate of 0.3/10a, and it was divided into two distinct dry and wet stages. Before 2018, it was mainly dry, after 2018, it was mainly humid. SPEI-3 decreased at a rate of 0.1/10a in spring, fluctuated significantly in summer, and increased in autumn and winter.(2) The annual SPEI-12 of most meteorological stations was less than 0, the SPEI value increased from northwest to southeast. Except for summer, the SPEI-3 value varied greatly in other seasons, increasing from west to east in spring, decreasing from south to north in autumn, and decreasing from west to east in winter.(3) GPP displayed a significant increasing trend (R2 = 0.57, p < 0.01) in Gansu from 2000 to 2020 .The spatial variation increased from northwest to southeast.(4) Annual SPEI-12 was positively correlated with GPP, SPEI-3 was negatively correlated with GPP in spring and autumn, and positively correlated in summer and winter. The correlation between SPEI-3 and GPP in summer passed the significance test.</jats:p
- …
