19 research outputs found

    Parasite motility is critical for virulence of African trypanosomes.

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    African trypanosomes, Trypanosoma brucei spp., are lethal pathogens that cause substantial human suffering and limit economic development in some of the world's most impoverished regions. The name Trypanosoma ("auger cell") derives from the parasite's distinctive motility, which is driven by a single flagellum. However, despite decades of study, a requirement for trypanosome motility in mammalian host infection has not been established. LC1 is a conserved dynein subunit required for flagellar motility. Prior studies with a conditional RNAi-based LC1 mutant, RNAi-K/R, revealed that parasites with defective motility could infect mice. However, RNAi-K/R retained residual expression of wild-type LC1 and residual motility, thus precluding definitive interpretation. To overcome these limitations, here we generate constitutive mutants in which both LC1 alleles are replaced with mutant versions. These double knock-in mutants show reduced motility compared to RNAi-K/R and are viable in culture, but are unable to maintain bloodstream infection in mice. The virulence defect is independent of infection route but dependent on an intact host immune system. By comparing different mutants, we also reveal a critical dependence on the LC1 N-terminus for motility and virulence. Our findings demonstrate that trypanosome motility is critical for establishment and maintenance of bloodstream infection, implicating dynein-dependent flagellar motility as a potential drug target

    Eliminating Gradient Conflict in Reference-based Line-Art Colorization

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    Reference-based line-art colorization is a challenging task in computer vision. The color, texture, and shading are rendered based on an abstract sketch, which heavily relies on the precise long-range dependency modeling between the sketch and reference. Popular techniques to bridge the cross-modal information and model the long-range dependency employ the attention mechanism. However, in the context of reference-based line-art colorization, several techniques would intensify the existing training difficulty of attention, for instance, self-supervised training protocol and GAN-based losses. To understand the instability in training, we detect the gradient flow of attention and observe gradient conflict among attention branches. This phenomenon motivates us to alleviate the gradient issue by preserving the dominant gradient branch while removing the conflict ones. We propose a novel attention mechanism using this training strategy, Stop-Gradient Attention (SGA), outperforming the attention baseline by a large margin with better training stability. Compared with state-of-the-art modules in line-art colorization, our approach demonstrates significant improvements in Fr\'echet Inception Distance (FID, up to 27.21%) and structural similarity index measure (SSIM, up to 25.67%) on several benchmarks. The code of SGA is available at https://github.com/kunkun0w0/SGA .Comment: Accepted by ECCV202

    Clinical outcome and prognostic factors of patients with non-traumatic angiography-negative subarachnoid hemorrhage

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    PurposeThe cause of spontaneous subarachnoid hemorrhage (SAH) is unknown in 10% of cases. The aim of this study was to demonstrate the characteristics of patients with angiography-negative subarachnoid hemorrhage (anSAH) and to analyze factors influencing the clinical outcome in patients suffering from anSAH.MethodsA retrospective cohort of 75 patients with anSAH [26 perimesencephalic (pmSAH) and 49 non-perimesencephalic SAH (npmSAH)] admitted between January 2016 and June 2022 was included. We analyzed demographic, clinical data and 6-month functional outcomes. Enter regression analysis was performed to identify factors associated with outcomes.ResultsUnfavorable outcome was achieved in 10 of 75 patients (13.3%). Unfavorable outcome was associated with senior adults (p = 0.008), Hijdra cistern score (HCS) elevation (p = 0.015), long-time lumbar cistern continuous drainage (LCFD; p = 0.029) and hydrocephalus (p = 0.046). The only significant risk factor for unfavorable outcome after npmSAH was the HCS (OR 1.213 (95%CI 1.007–1.462), p = 0.042).ConclusionOur study provides valuable information on both SAH patterns and functional outcome in patients suffering from anSAH and should be taken into consideration during management of these patients

    Data Augmentation of a Corrosion Dataset for Defect Growth Prediction of Pipelines Using Conditional Tabular Generative Adversarial Networks

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    Due to corrosion characteristics, there are data scarcity and uneven distribution in corrosion datasets, and collecting high-quality data is time-consuming and sometimes difficult. Therefore, this work introduces a novel data augmentation strategy using a conditional tabular generative adversarial network (CTGAN) for enhancing corrosion datasets of pipelines. Firstly, the corrosion dataset is subjected to data cleaning and variable correlation analysis. The CTGAN is then used to generate external environmental factors as input variables for corrosion growth prediction, and a hybrid model based on machine learning is employed to generate corrosion depth as an output variable. The fake data are merged with the original data to form the synthetic dataset. Finally, the proposed data augmentation strategy is verified by analyzing the synthetic dataset using different visualization methods and evaluation indicators. The results show that the synthetic and original datasets have similar distributions, and the data augmentation strategy can learn the distribution of real corrosion data and sample fake data that are highly similar to the real data. Predictive models trained on the synthetic dataset perform better than predictive models trained using only the original dataset. In comparative tests, the proposed strategy outperformed other data generation methods

    Social appearance anxiety among the dark tetrad and self-concealment

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    Abstract This study analyzed the effects of the Dark Tetrad (narcissism, Machiavellianism, psychopathy, sadism) and self-concealment on social appearance anxiety. Empirical investigations on which personality traits influence social appearance anxiety are yet missing. In this study, a sample of N = 1186 Chinese students performed a questionnaire-based survey assessing different personality facets and social appearance anxiety tendencies. Measures included the Narcissistic Personality Inventory, the Levenson Self-Report Psychopathy Scale, the Machiavellian Personality Scale, the Short Sadistic Impulse Scale, the Self-concealment Scale, and the Social Appearance Anxiety Scale. The results of the multiple regression analysis showed that psychopathy, Machiavellianism, sadism, and self-concealment positively predicted social appearance anxiety and narcissism negatively predicted social appearance anxiety. Machiavellianism, psychopathy, sadism, and self-concealment were positive predictors of social appearance anxiety, whereas narcissism was a negative predictor. These findings provide insight into the complex nature of the Dark Tetrad and their influence on social appearance anxiety

    Struggling or Liberating? The Effects of Machiavellianism on Break-Up Distress

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    Negative emotions caused by break-up are the key work of university students’ psychological intervention. It is important to explore the specific factors of break-up distress for university students’ psychological intervention. Therefore, we investigated 869 university students to examine the effect of Machiavellianism and psychological capital on break-up distress, as well as its gender difference. The results indicated that high Machiavellians experience more break-up distress. Moreover, through structural equation models, we found that as for female university students, psychological capital mediated the relationship between Machiavellianism and break-up distress. However, as for male university students, the mediation effect was not significant. It means that for female university students, psychological capital acted as the mechanism to connect Machiavellianism and break-up distress

    Deep Learning Architecture for Estimating Hourly Ground-Level PM 2.5

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    Hybrid surgery can improve neurocognitive function in patients with internal carotid artery occlusion

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    Abstract Internal carotid artery occlusion (ICAO) is a relatively uncommon but important cause of transient ischaemic attack and cerebral infarction. Hybrid surgery (HS) improves cerebral perfusion, but its impact on neurocognitive function has been controversial. Patients with symptomatic chronic ICAO treated by hybrid surgery or medical treatment from 2016 to 2019 were included. We recorded and analysed the clinical characteristics, angiographic data, outcomes and cognitive status. Functional assessments, including the National Institutes of Health Stroke Scale (NIHSS), the Barthel Index, and a battery of neuropsychological tests, including the Mini-Mental State Examination (MMSE), Alzheimer Disease Assessment Scale–Cognitive Subtest (ADAS-cog), verbal fluency, and Colour Trail test Parts 1 and 2, were administered. Significant improvements in the ADAS (before, 7.5 ± 6.2 versus after, 5.2 ± 5.7; P = 0.022), MMSE (before, 25.5 ± 2.8 versus after, 28.1 ± 2.3; P = 0.013), and Colour Trail test Part 1 (before, 118.3 ± 26.5 versus after, 96.2 ± 23.1; P = 0.016) were observed six months after HS. Moreover, the abovementioned postprocedure scales were ameliorated in the HS group. This study found that in patients with multiple symptomatic ICAO and objective ipsilateral ischaemia, successful HS leads to improvement in the scores of three cognitive tests
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