866 research outputs found
Acoustic dynamics of nanoparticles and nanostructured phononic crystals
Ph.DDOCTOR OF PHILOSOPH
Minimalist and High-Performance Semantic Segmentation with Plain Vision Transformers
In the wake of Masked Image Modeling (MIM), a diverse range of plain,
non-hierarchical Vision Transformer (ViT) models have been pre-trained with
extensive datasets, offering new paradigms and significant potential for
semantic segmentation. Current state-of-the-art systems incorporate numerous
inductive biases and employ cumbersome decoders. Building upon the original
motivations of plain ViTs, which are simplicity and generality, we explore
high-performance `minimalist' systems to this end. Our primary purpose is to
provide simple and efficient baselines for practical semantic segmentation with
plain ViTs. Specifically, we first explore the feasibility and methodology for
achieving high-performance semantic segmentation using the last feature map. As
a result, we introduce the PlainSeg, a model comprising only three 33
convolutions in addition to the transformer layers (either encoder or decoder).
In this process, we offer insights into two underlying principles: (i)
high-resolution features are crucial to high performance in spite of employing
simple up-sampling techniques and (ii) the slim transformer decoder requires a
much larger learning rate than the wide transformer decoder. On this basis, we
further present the PlainSeg-Hier, which allows for the utilization of
hierarchical features. Extensive experiments on four popular benchmarks
demonstrate the high performance and efficiency of our methods. They can also
serve as powerful tools for assessing the transfer ability of base models in
semantic segmentation. Code is available at
\url{https://github.com/ydhongHIT/PlainSeg}
Representation Separation for Semantic Segmentation with Vision Transformers
Vision transformers (ViTs) encoding an image as a sequence of patches bring
new paradigms for semantic segmentation.We present an efficient framework of
representation separation in local-patch level and global-region level for
semantic segmentation with ViTs. It is targeted for the peculiar
over-smoothness of ViTs in semantic segmentation, and therefore differs from
current popular paradigms of context modeling and most existing related methods
reinforcing the advantage of attention. We first deliver the decoupled
two-pathway network in which another pathway enhances and passes down
local-patch discrepancy complementary to global representations of
transformers. We then propose the spatially adaptive separation module to
obtain more separate deep representations and the discriminative
cross-attention which yields more discriminative region representations through
novel auxiliary supervisions. The proposed methods achieve some impressive
results: 1) incorporated with large-scale plain ViTs, our methods achieve new
state-of-the-art performances on five widely used benchmarks; 2) using masked
pre-trained plain ViTs, we achieve 68.9% mIoU on Pascal Context, setting a new
record; 3) pyramid ViTs integrated with the decoupled two-pathway network even
surpass the well-designed high-resolution ViTs on Cityscapes; 4) the improved
representations by our framework have favorable transferability in images with
natural corruptions. The codes will be released publicly.Comment: 17 pages, 13 figures. This work has been submitted to the IEEE for
possible publication. Copyright may be transferred without notice, after
which this version may no longer be accessibl
Automatic thickness estimation for skeletal muscle in ultrasonography: evaluation of two enhancement methods
BACKGROUND: Ultrasonography is a convenient technique to investigate muscle properties and has been widely used to look into muscle functions since it is non-invasive and real-time. Muscle thickness, a quantification which can effectively reflect the muscle activities during muscle contraction, is an important measure for musculoskeletal studies using ultrasonography. The traditional manual operation to read muscle thickness is subjective and time-consuming, therefore a number of studies have focused on the automatic estimation of muscle fascicle orientation and muscle thickness, to which the speckle noises in ultrasound images could be the major obstacle. There have been two popular methods proposed to enhance the hyperechoic regions over the speckles in ultrasonography, namely Gabor Filtering and Multiscale Vessel Enhancement Filtering (MVEF). METHODS: A study on gastrocnemius muscle is conducted to quantitatively evaluate whether and how these two methods could help the automatic estimation of the muscle thickness based on Revoting Hough Transform (RVHT). The muscle thickness results obtained from each of the two methods are compared with the results from manual measurement, respectively. Data from an aged subject with cerebral infarction is also studied. RESULTS: It’s shown in the experiments that, Gabor Filtering and MVEF can both enable RVHT to generate comparable results of muscle thickness to those by manual drawing (mean ± SD, 1.45 ± 0.48 and 1.38 ± 0.56 mm respectively). However, the MVEF method requires much less computation than Gabor Filtering. CONCLUSIONS: Both methods, as preprocessing procedure can enable RVHT the automatic estimation of muscle thickness and MVEF is believed to be a better choice for real-time applications
The effect of Dnaaf5 gene dosage on primary ciliary dyskinesia phenotypes
DNAAF5 is a dynein motor assembly factor associated with the autosomal heterogenic recessive condition of motile cilia, primary ciliary dyskinesia (PCD). The effects of allele heterozygosity on motile cilia function are unknown. We used CRISPR-Cas9 genome editing in mice to recreate a human missense variant identified in patients with mild PCD and a second, frameshift-null deletion in Dnaaf5. Litters with Dnaaf5 heteroallelic variants showed distinct missense and null gene dosage effects. Homozygosity for the null Dnaaf5 alleles was embryonic lethal. Compound heterozygous animals with the missense and null alleles showed severe disease manifesting as hydrocephalus and early lethality. However, animals homozygous for the missense mutation had improved survival, with partially preserved cilia function and motor assembly observed by ultrastructure analysis. Notably, the same variant alleles exhibited divergent cilia function across different multiciliated tissues. Proteomic analysis of isolated airway cilia from mutant mice revealed reduction in some axonemal regulatory and structural proteins not previously reported in DNAAF5 variants. Transcriptional analysis of mouse and human mutant cells showed increased expression of genes coding for axonemal proteins. These findings suggest allele-specific and tissue-specific molecular requirements for cilia motor assembly that may affect disease phenotypes and clinical trajectory in motile ciliopathies
Patterns of pediatric and adolescent female genital inflammation in China: an eight-year retrospective study of 49,175 patients in China
BackgroundGenital inflammation is one of the most frequent clinical complaints among girls, which was easily overlooked by the general public. This study aimed to investigate the patterns and epidemiological characteristics of pediatric and adolescent female genital inflammation in China.MethodsA retrospective observational study (2011 to 2018) was conducted among all female patients under the age of 0–18 years at the Department of Pediatric and Adolescent Gynecology of The Children’s Hospital, Zhejiang University School of Medicine. Data were collected from the electronic medical records. The abnormal vaginal discharge of patient was collected for microbiological investigation by bacterial and fungal culture. Descriptive analysis was conducted to evaluate the genital inflammation pattern and epidemiological characteristics, including age, season, and type of infected pathogens.ResultsA total of 49,175 patients met the eligibility criteria of genital inflammation and 16,320 patients later came to the hospital for follow-up over the study period. The number of first-visit increased gradually from 3,769 in 2011 to 10,155 in 2018. The peak age of the first visit was 0–6 years old. Non-specific vulvovaginitis, lichen sclerosis, and labial adhesion were the top three genital inflammation. Among the top five potential common pathogens of vaginal infection, the prevalence of Haemophilus influenzae cases was the highest (31.42%, 203/646), followed by Streptococcus pyogenes (27.74%, 176/646), Candida albicans (14.09%, 91/646), Escherichia coli (8.51%, 55/646), and Staphylococcus aureus (6.35%, 41/636). The specific disease categories and pathogens of genital inflammation vary by age groups and season.ConclusionOur study summarizes the pattern of pediatric and adolescent female genital inflammation over an 8-year period in China, emphasizing the need for more public awareness, healthcare services and research in this field
Auditor of State Mary Mosiman today released a reaudit report on the Mason City Community School District (District) for the period July 1, 2014 through June 30, 2015. The reaudit also covered items applicable to the years ended June 30, 2016 and June 30, 2017.
Auditor of State Mary Mosiman today released a reaudit report on the Mason City Community School District (District) for the period July 1, 2014 through June 30, 2015. The reaudit also covered items applicable to the years ended June 30, 2016 and June 30, 2017
Clinical implications of trichomonads detected in bronchoalveolar fluid by metagenomic next-generation sequencing: a multicenter retrospective study
BackgroundPulmonary trichomoniasis is considered a neglected disease due to failures in recognizing it, stemming from insensitive microbial methods and a lack of specific clinical features. This study aims to analyze the clinical implications of trichomonads detected in bronchoalveolar lavage fluid (BALF) by metagenomic next-generation sequencing (mNGS).MethodsThis multicenter retrospective study included patients diagnosed with pneumonia, admitted to three tertiary hospitals in China from July 2018 to September 2022, with trichomonads detected in BALF through mNGS. The analysis covered demographics, comorbidities, symptoms, laboratory findings, mNGS results, clinical treatment, and outcomes of these patients.ResultsA total of 17 patients were enrolled, comprising 14 males and 3 females. Trichomonas tenax and Trichomonas vaginalis were detected by mNGS in BALF samples of 15 and 2 patients, respectively. Patients were categorized into two groups based on the presence of risk factors for trichomonad infection, including immunocompromised conditions, uncontrolled diabetes mellitus, oral/periodontal diseases, and aspiration. Among 11 patients with risk factors (Case 1-11), 4 received nitromidazoles as part of comprehensive treatment, achieving a 100% treatment success rate. The remaining 7 patients, who did not receive nitromidazoles, had only one achieving relief after broad-spectrum antimicrobial therapy, resulting in a 14.3% treatment success rate. For the 6 patients without any risk factors for trichomonad infection (Case 12-17), none received nitromidazoles during hospitalization. However, 4 out of these 6 patients (66.7%) eventually recovered.ConclusionmNGS proves to be an efficient tool for detecting trichomonads in BALF samples. Comprehensive analysis of clinical features and laboratory indicators is essential to distinguish between infection and colonization of trichomonads. Pulmonary trichomoniasis should not be overlooked when trichomonads are detected in BALF from patients with risk factors
Search for the decay
We search for radiative decays into a weakly interacting neutral
particle, namely an invisible particle, using the produced through the
process in a data sample of
decays collected by the BESIII detector
at BEPCII. No significant signal is observed. Using a modified frequentist
method, upper limits on the branching fractions are set under different
assumptions of invisible particle masses up to 1.2 . The upper limit corresponding to an invisible particle with zero mass
is 7.0 at the 90\% confidence level
Observation of in
Using a sample of events recorded with
the BESIII detector at the symmetric electron positron collider BEPCII, we
report the observation of the decay of the charmonium state
into a pair of mesons in the process
. The branching fraction is measured for the first
time to be , where the first uncertainty is
statistical, the second systematic and the third is from the uncertainty of
. The mass and width of the are
determined as MeV/ and
MeV.Comment: 13 pages, 6 figure
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