529 research outputs found
Genome-Wide Association Study for Plant Height and Grain Yield in Rice under Contrasting Moisture Regimes
Drought is one of the vitally critical environmental stresses affecting both growth and yield potential in rice. Drought resistance is a complicated quantitative trait that is regulated by numerous small effect loci and hundreds of genes controlling various morphological and physiological responses to drought. For this study, 270 rice landraces and cultivars were analyzed for their drought resistance. This was done via determination of changes in plant height and grain yield under contrasting water regimes, followed by detailed identification of the underlying genetic architecture via genome-wide association study (GWAS). We controlled population structure by setting top two eigenvectors and combining kinship matrix for GWAS in this study. Eighteen, five, and six associated loci were identified for plant height, grain yield per plant, and drought resistant coefficient, respectively. Nine known functional genes were identified, including five for plant height (OsGA2ox3, OsGH3-2, sd-1, OsGNA1 and OsSAP11/OsDOG), two for grain yield per plant (OsCYP51G3 and OsRRMh) and two for drought resistant coefficient (OsPYL2 and OsGA2ox9), implying very reliable results. A previous study reported OsGNA1 to regulate root development, but this study reports additional controlling of both plant height and root length. Moreover, OsRLK5 is a new drought resistant candidate gene discovered in this study. OsRLK5 mutants showed faster water loss rates in detached leaves. This gene plays an important role in the positive regulation of yield-related traits under drought conditions. We furthermore discovered several new loci contributing to the three investigated traits (plant height, grain yield, and drought resistance). These associated loci and genes significantly improve our knowledge of the genetic control of these traits in rice. In addition, many drought resistant cultivars screened in this study can be used as parental genotypes to improve drought resistance of rice by molecular breeding
Deep Feature Statistics Mapping for Generalized Screen Content Image Quality Assessment
The statistical regularities of natural images, referred to as natural scene
statistics, play an important role in no-reference image quality assessment.
However, it has been widely acknowledged that screen content images (SCIs),
which are typically computer generated, do not hold such statistics. Here we
make the first attempt to learn the statistics of SCIs, based upon which the
quality of SCIs can be effectively determined. The underlying mechanism of the
proposed approach is based upon the mild assumption that the SCIs, which are
not physically acquired, still obey certain statistics that could be understood
in a learning fashion. We empirically show that the statistics deviation could
be effectively leveraged in quality assessment, and the proposed method is
superior when evaluated in different settings. Extensive experimental results
demonstrate the Deep Feature Statistics based SCI Quality Assessment (DFSS-IQA)
model delivers promising performance compared with existing NR-IQA models and
shows a high generalization capability in the cross-dataset settings. The
implementation of our method is publicly available at
https://github.com/Baoliang93/DFSS-IQA
P-Mamba: Marrying Perona Malik Diffusion with Mamba for Efficient Pediatric Echocardiographic Left Ventricular Segmentation
In pediatric cardiology, the accurate and immediate assessment of cardiac
function through echocardiography is crucial since it can determine whether
urgent intervention is required in many emergencies. However, echocardiography
is characterized by ambiguity and heavy background noise interference, causing
more difficulty in accurate segmentation. Present methods lack efficiency and
are prone to mistakenly segmenting some background noise areas, such as the
left ventricular area, due to noise disturbance. To address these issues, we
introduce P-Mamba, which integrates the Mixture of Experts (MoE) concept for
efficient pediatric echocardiographic left ventricular segmentation.
Specifically, we utilize the recently proposed ViM layers from the vision mamba
to enhance our model's computational and memory efficiency while modeling
global dependencies.In the DWT-based Perona-Malik Diffusion (PMD) Block, we
devise a PMD Block for noise suppression while preserving the left ventricle's
local shape cues. Consequently, our proposed P-Mamba innovatively combines the
PMD's noise suppression and local feature extraction capabilities with Mamba's
efficient design for global dependency modeling. We conducted segmentation
experiments on two pediatric ultrasound datasets and a general ultrasound
dataset, namely Echonet-dynamic, and achieved state-of-the-art (SOTA) results.
Leveraging the strengths of the P-Mamba block, our model demonstrates superior
accuracy and efficiency compared to established models, including vision
transformers with quadratic and linear computational complexity
Endogenous mobility in pandemics: theory and evidence from the United States
We study infectious diseases in a spatial epidemiology model with forward-looking individuals who weigh disease environments against economic opportunities when moving across regions. This endogenous mobility allows regions to share risk and health resources, resulting in positive epidemiological externalities for regions with high R0s. We develop the Normalized Hat Algebra to analyze disease and mobility dynamics. Applying our model to US data, we find that cross-state mobility controls that hinder risk and resource sharing increase COVID-19 deaths and decrease social welfare. Conversely, by enabling "self-containment" and "self-healing," endogenous mobility reduces COVID-19 infections by 27.6% and deaths by 22.1%
Impact of vaccination on the COVID-19 pandemic in U.S. states
Governments worldwide are implementing mass vaccination programs in an effort to end the novel coronavirus (COVID-19) pandemic. Here, we evaluated the effectiveness of the COVID-19 vaccination program in its early stage and predicted the path to herd immunity in the U.S. By early March 2021, we estimated that vaccination reduced the total number of new cases by 4.4 million (from 33.0 to 28.6 million), prevented approximately 0.12 million hospitalizations (from 0.89 to 0.78 million), and decreased the population infection rate by 1.34 percentage points (from 10.10 to 8.76%). We built a Susceptible-Infected-Recovered (SIR) model with vaccination to predict herd immunity, following the trends from the early-stage vaccination program. Herd immunity could be achieved earlier with a faster vaccination pace, lower vaccine hesitancy, and higher vaccine effectiveness. The Delta variant has substantially postponed the predicted herd immunity date, through a combination of reduced vaccine effectiveness, lowered recovery rate, and increased infection and death rates. These findings improve our understanding of the COVID-19 vaccination and can inform future public health policies
Endogenous cross-region human mobility and pandemics
We study infectious diseases using a Susceptible-Infected-Recovered-Deceased model with endogenous cross-region human mobility. Individuals weigh the risk of infection against economic opportunities when moving across regions. The model predicts that the mobility rate of susceptible individuals declines with a higher infection rate at the destination. With cross-region mobility, a decrease in the transmission rate or an increase in the removal rate of the virus in any region reduces the global basic reproduction number (R0). Global R0 falls between the minimum and maximum of local R0s. A new method of Normalized Hat Algebra is developed to solve the model dynamics. Simulations indicate that a decrease in global R0 does not always imply a lower cumulative infection rate. Local and central governments may prefer different mobility control policies
Qi standard metasurface for free-positioning and multi-device supportive wireless power transfer
Free-positioning and multi-user supportive wireless power transfer systems
represent the next-generation technology for wireless charging under the Qi
standard. Traditional approaches employ multiple transmitting coils and
multi-channel driving circuits with active control algorithms to achieve these
goals. However, these traditional approaches are significantly limited by cost,
weight, and heating due to their relatively low efficiency. Here, we
demonstrate an innovative approach by using a metasurface to achieve
free-positioning and multi-user compatibility. The metasurface works as a
passive device to reform the magnetic field and enables high-efficiency
free-positioning wireless power transfer with only a single transmitting coil.
It shows up to 4.6 times improvement in efficiency. The metasurface also
increases the coverage area from around 5 cm by 5 cm with over 40% efficiency
to around 10 cm by 10 cm with over 70% efficiency. We further show that the
system can support multiple receivers. Besides increasing the overall
efficiency, we demonstrate tuning the power division between the multiple
receivers, enabling compensation of receivers of different sizes to achieve
their desired power
A Survey on Visual Mamba
State space models (SSMs) with selection mechanisms and hardware-aware
architectures, namely Mamba, have recently demonstrated significant promise in
long-sequence modeling. Since the self-attention mechanism in transformers has
quadratic complexity with image size and increasing computational demands, the
researchers are now exploring how to adapt Mamba for computer vision tasks.
This paper is the first comprehensive survey aiming to provide an in-depth
analysis of Mamba models in the field of computer vision. It begins by
exploring the foundational concepts contributing to Mamba's success, including
the state space model framework, selection mechanisms, and hardware-aware
design. Next, we review these vision mamba models by categorizing them into
foundational ones and enhancing them with techniques such as convolution,
recurrence, and attention to improve their sophistication. We further delve
into the widespread applications of Mamba in vision tasks, which include their
use as a backbone in various levels of vision processing. This encompasses
general visual tasks, Medical visual tasks (e.g., 2D / 3D segmentation,
classification, and image registration, etc.), and Remote Sensing visual tasks.
We specially introduce general visual tasks from two levels: High/Mid-level
vision (e.g., Object detection, Segmentation, Video classification, etc.) and
Low-level vision (e.g., Image super-resolution, Image restoration, Visual
generation, etc.). We hope this endeavor will spark additional interest within
the community to address current challenges and further apply Mamba models in
computer vision
DeepWSD: Projecting Degradations in Perceptual Space to Wasserstein Distance in Deep Feature Space
Existing deep learning-based full-reference IQA (FR-IQA) models usually
predict the image quality in a deterministic way by explicitly comparing the
features, gauging how severely distorted an image is by how far the
corresponding feature lies from the space of the reference images. Herein, we
look at this problem from a different viewpoint and propose to model the
quality degradation in perceptual space from a statistical distribution
perspective. As such, the quality is measured based upon the Wasserstein
distance in the deep feature domain. More specifically, the 1DWasserstein
distance at each stage of the pre-trained VGG network is measured, based on
which the final quality score is performed. The deep Wasserstein distance
(DeepWSD) performed on features from neural networks enjoys better
interpretability of the quality contamination caused by various types of
distortions and presents an advanced quality prediction capability. Extensive
experiments and theoretical analysis show the superiority of the proposed
DeepWSD in terms of both quality prediction and optimization.Comment: ACM Multimedia 2022 accepted thesi
Research on prognostic risk assessment model for acute ischemic stroke based on imaging and multidimensional data
Accurately assessing the prognostic outcomes of patients with acute ischemic stroke and adjusting treatment plans in a timely manner for those with poor prognosis is crucial for intervening in modifiable risk factors. However, there is still controversy regarding the correlation between imaging-based predictions of complications in acute ischemic stroke. To address this, we developed a cross-modal attention module for integrating multidimensional data, including clinical information, imaging features, treatment plans, prognosis, and complications, to achieve complementary advantages. The fused features preserve magnetic resonance imaging (MRI) characteristics while supplementing clinical relevant information, providing a more comprehensive and informative basis for clinical diagnosis and treatment. The proposed framework based on multidimensional data for activity of daily living (ADL) scoring in patients with acute ischemic stroke demonstrates higher accuracy compared to other state-of-the-art network models, and ablation experiments confirm the effectiveness of each module in the framework
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