29 research outputs found
Federated Learning's Blessing: FedAvg has Linear Speedup
Federated learning (FL) learns a model jointly from a set of participating
devices without sharing each other's privately held data. The characteristics
of non-iid data across the network, low device participation, and the mandate
that data remain private bring challenges in understanding the convergence of
FL algorithms, particularly in regards to how convergence scales with the
number of participating devices. In this paper, we focus on Federated Averaging
(FedAvg)--the most widely used and effective FL algorithm in use today--and
provide a comprehensive study of its convergence rate. Although FedAvg has
recently been studied by an emerging line of literature, it remains open as to
how FedAvg's convergence scales with the number of participating devices in the
FL setting--a crucial question whose answer would shed light on the performance
of FedAvg in large FL systems. We fill this gap by establishing convergence
guarantees for FedAvg under three classes of problems: strongly convex smooth,
convex smooth, and overparameterized strongly convex smooth problems. We show
that FedAvg enjoys linear speedup in each case, although with different
convergence rates. For each class, we also characterize the corresponding
convergence rates for the Nesterov accelerated FedAvg algorithm in the FL
setting: to the best of our knowledge, these are the first linear speedup
guarantees for FedAvg when Nesterov acceleration is used. To accelerate FedAvg,
we also design a new momentum-based FL algorithm that further improves the
convergence rate in overparameterized linear regression problems. Empirical
studies of the algorithms in various settings have supported our theoretical
results
SoybeanNet: Transformer-Based Convolutional Neural Network for Soybean Pod Counting from Unmanned Aerial Vehicle (UAV) Images
Soybeans are a critical source of food, protein and oil, and thus have
received extensive research aimed at enhancing their yield, refining
cultivation practices, and advancing soybean breeding techniques. Within this
context, soybean pod counting plays an essential role in understanding and
optimizing production. Despite recent advancements, the development of a robust
pod-counting algorithm capable of performing effectively in real-field
conditions remains a significant challenge This paper presents a pioneering
work of accurate soybean pod counting utilizing unmanned aerial vehicle (UAV)
images captured from actual soybean fields in Michigan, USA. Specifically, this
paper presents SoybeanNet, a novel point-based counting network that harnesses
powerful transformer backbones for simultaneous soybean pod counting and
localization with high accuracy. In addition, a new dataset of UAV-acquired
images for soybean pod counting was created and open-sourced, consisting of 113
drone images with more than 260k manually annotated soybean pods captured under
natural lighting conditions. Through comprehensive evaluations, SoybeanNet
demonstrated superior performance over five state-of-the-art approaches when
tested on the collected images. Remarkably, SoybeanNet achieved a counting
accuracy of when tested on the testing dataset, attesting to its
efficacy in real-world scenarios. The publication also provides both the source
code (\url{https://github.com/JiajiaLi04/Soybean-Pod-Counting-from-UAV-Images})
and the labeled soybean dataset
(\url{https://www.kaggle.com/datasets/jiajiali/uav-based-soybean-pod-images}),
offering a valuable resource for future research endeavors in soybean pod
counting and related fields.Comment: 12 pages, 5 figure
The effect of water temperature on the pathogenicity of decapod iridescent virus 1 (DIV1) in Litopenaeus vannamei
Decapod iridescent virus 1 (DIV1) has caused huge losses to the shrimp breeding industry in recent years as a new shrimp virus. In this study, white leg shrimp, Litopenaeus vannamei, were cultured at different temperatures (26 ± 1 °C and 32 ± 1 °C) and the same salinity, then infected with DIV1 by intramuscular injection to determine the effects of water temperature on viral infection. The DIV1 copy counts in the gills, hepatopancreas, pleopods, intestines, and muscles of L. vannamei were measured in samples collected at 6, 12, and 24 h post-infection (hpi), and the survival rate of L. vannamei was assessed every 6 h after infection. At 96 hpi, the survival rates of L. vannamei in the high (32 ± 1 ℃) and standard (26 ± 1 ℃) water temperature groups were 2.22% and 4.44%, respectively. The peak time of mortality in the high-water temperature group was 6 h earlier than in the standard water temperature group. After 24 hours of DIV1 infection, the DIV1 copy counts in the standard water temperature treatment group were significantly higher than those in the high-water temperature treatment group. The tissues with the highest virus copy counts in the standard and high-temperature groups were the intestines (2.9×1011 copies/g) and muscles (7.0×108 copies/g). The effect of temperature on the pathogenicity of DIV1 differs from that of other previously studied viruses, such as white spot syndrome virus, Taura syndrome virus, and infectious hypodermal and hematopoietic necrosis virus, because the high-water temperature did not mitigate the damage caused by DIV1 infection
Berberine Radiosensitizes Human Esophageal Cancer Cells by Downregulating Homologous Recombination Repair Protein RAD51
Esophageal squamous cell carcinomas (ESCC) have poor prognosis. While combined modality of chemotherapy and radiotherapy increases survival, most patients die within five years. Development of agents that confer cancer cell-specific chemo- and radiosensitivity may improve the therapy of ESCC. We here reported the discovery of berberine as a potent radiosensitizing agent on ESCC cells. by RNA interference similarly radiosensitized the cancer cells, and, conversely, introduction of exogenous RAD51 was able to significantly counteract the radiosensitizing effect of berberine, thus establishing RAD51 as a key determinant in radiation sensitivity. We also observed that RAD51 was commonly overexpressed in human ESCC tissues, suggesting that it is necessary to downregulate RAD51 to achieve high radio- or chemotherapeutic efficacy of ESCC in clinic, because overexpression of RAD51 is known to confer radio- and chemoresistance.Berberine can effectively downregulate RAD51 in conferring radiosensitivity on esophageal cancer cells. Its clinical application as an adjuvant in chemotherapy and radiotherapy of esophageal cancers should be explored
Polarization conversion in bottom-up grown quasi-1D fibrous red phosphorus flakes
Abstract Fibrous red phosphorus (RP) has triggered growing attention as an emerging quasi-one-dimensional (quasi-1D) van der Waals crystal recently. Unfortunately, it is difficult to achieve substrate growth of high-quality fibrous RP flakes due to their inherent quasi-1D structure, which impedes their fundamental property exploration and device integration. Herein, we demonstrate a bottom-up approach for the growth of fibrous RP flakes with (001)-preferred orientation via a chemical vapor transport (CVT) reaction in the P/Sn/I2 system. The formation of fibrous RP flakes can be attributed to the synergistic effect of Sn-mediated P4 partial pressure and the SnI2 capping layer-directed growth. Moreover, we investigate the optical anisotropy of the as-grown flakes, demonstrating their potential application as micro phase retarders in polarization conversion. Our developed bottom-up approach lays the foundation for studying the anisotropy and device integration of fibrous red phosphorus, opening up possibilities for the two-dimensional growth of quasi-1D van der Waals materials
Hot-casting assisted liquid additive engineering for efficient and stable perovskite solar cells
High-performance inorganic-organic lead halide perovskite solar cells (PSCs) are often fabricated with a liquid additive such as dimethyl sulfoxide (DMSO) which retards crystallization and reduces roughness and pinholes in the perovskite layers. However, DMSO can be trapped during perovskite film formation and induce voids and undesired reaction byproducts upon later processing steps. Here, we show that we can reduce the amount of residual DMSO in as-spin-coated films significantly - by 30 times - through use of pre-heated substrates, or a so-called hot-casting method. Hot-casting increases the perovskite film thickness which allows us to reduce the perovskite solution concentration. By reducing the amount of DMSO in proportion to the concentration of perovskite precursors and using hot-casting, we are able to fabricate perovskite layers with improved perovskite-substrate buried interfaces by suppressing the formation of byproducts which increase trap density and accelerate degradation of the perovskite layers. The best-performing PSCs exhibit power conversion efficiency (PCE) of 23.4% (23.0% stabilized efficiency) under simulated solar illumination. Furthermore, encapsulated devices showed considerably reduced post-burn-in decay of -0.84% of initial efficiency per 100 h, retaining more than 80% and 93% of their initial and post-burn-in efficiencies after 800 h of operation with maximum power point tracking (MPPT) under high-power of ultraviolet-(UV-)containing continuous light exposure (overall power density of 1.1 sun with 2.6 times higher UV-region power density than AM 1.5G)
Smart Steering Sleeve (S3): A Non-Intrusive and Integrative Sensing Platform for Driver Physiological Monitoring
Driving is a ubiquitous activity that requires both motor skills and cognitive focus. These aspects become more problematic for some seniors, who have underlining medical conditions and tend to lose some of these capabilities. Therefore, driving can be used as a controlled environment for the frequent, non-intrusive monitoring of bio-physical and cognitive status within drivers. Such information can then be utilized for enhanced assistive vehicle controls and/or driver health monitoring. In this paper, we present a novel multi-modal smart steering sleeve (S3) system with an integrated sensing platform that can non-intrusively and continuously measure a driver’s physiological signals, including electrodermal activity (EDA), electromyography (EMG), and hand pressure. The sensor suite was developed by combining low-cost interdigitated electrodes with a piezoresistive force sensor on a single, flexible polymer substrate. Comprehensive characterizations on the sensing modalities were performed with promising results demonstrated. The sweat-sensing unit (SSU) for EDA monitoring works under a 100 Hz alternative current (AC) source. The EMG signal acquired by the EMG-sensing unit (EMGSU) was amplified to within 5 V. The force-sensing unit (FSU) for hand pressure detection has a range of 25 N. This flexible sensor was mounted on an off-the-shelf steering wheel sleeve, making it an add-on system that can be installed on any existing vehicles for convenient and wide-coverage driver monitoring. A cloud-based communication scheme was developed for the ease of data collection and analysis. Sensing platform development, performance, and limitations, as well as other potential applications, are discussed in detail in this paper
USP10 Antagonizes c-Myc Transcriptional Activation through SIRT6 Stabilization to Suppress Tumor Formation
The reduced protein expression of SIRT6 tumor suppressor is involved in tumorigenesis. The molecular mechanisms underlying SIRT6 protein downregulation in human cancers remain unknown. Using a proteomic approach, we have identified the ubiquitin-specific peptidase USP10, another tumor suppressor, as one of the SIRT6-interacting proteins. USP10 suppresses SIRT6 ubiquitination to protect SIRT6 from proteasomal degradation. USP10 antagonizes the transcriptional activity of the c-Myc oncogene through SIRT6, as well as p53, to inhibit cell-cycle progression, cancer cell growth, and tumor formation. To support this conclusion, we detected significant reductions in both USP10 and SIRT6 protein expression in human colon cancers. Our study discovered crosstalk between two tumor-suppressive genes in regulating cell-cycle progression and proliferation and showed that dysregulated USP10 function promotes tumorigenesis through SIRT6 degradation