2,088 research outputs found
The properties of small magnetic flux ropes inside the solar wind come from coronal holes, active regions, and quiet Sun
The origination and generation mechanisms of small magnetic flux ropes
(SFRs), which are important structures in solar wind, are not clearly known. In
present study, 1993 SFRs immersed in coronal holes, active regions, and quiet
Sun solar wind are analyzed and compared. We find that the properties of SFRs
immersed in three types of solar wind are signicantly different. The SFRs are
further classifed into hot-SFRs, cold-SFRs, and normal-SFRs, according to
whether the O7+/O6+ is 30% elevated or dropped inside SFRs as compared with
background solar wind. Our studies show that the parameters of normal-SFRs are
similar to background in all three types of solar wind. The properties of
hot-SFRs and cold-SFRs seem to be lying in two extremes. Statistically, the
hot-SFRs (cold-SFRs) are associated with longer (shorter) duration, lower
(higher) speeds and proton temperatures, higher (lower) charge states, helium
abundance, and FIP bias as compared with normal-SFRs and background solar wind.
The anti-correlations between speed and O7+/O6+ inside hot-SFRs (normal-SFRs)
are different from (similar to) those in background solar wind. Most of
hot-SFRs and cold-SFRs should come from the Sun. Hot-SFRs may come from
streamers associated with plasma blobs and/or small-scale activities on the
Sun. Cold-SFRs may be accompanied by small-scale eruptions with
lower-temperature materials. Both hot-SFRs and cold-SFRs could also be formed
by magnetic erosions of ICMEs that do not contain or contain cold-filament
materials. The characteristics of normal-SFRs can be explained reasonably by
the two originations, from the Sun and generated in the heliosphere both.Comment: 19 pages, 5 figure
6-Mercaptopurine attenuates tumor necrosis factor-α production in microglia through Nur77-mediated transrepression and PI3K/Akt/mTOR signaling-mediated translational regulation
Physical interaction between Nur77 and p65. BV-2 cells were pretreated with 6-MP (50 μM) for 16 h followed by exposure to LPS (100 ng/ml) for 60 min. Nuclear extracts were harvested for immunoprecipitation (IP) experiments using anti-Nur77 and anti-p65 antibodies. Immunoblot (IB) analyses of the immunoprecipitates were performed using these antibodies. The immunoblots are representative of three independent experiments. (TIF 280 kb
Changes in the proteomic profiles of mouse brain after infection with cyst-forming Toxoplasma gondii
Background
Toxoplasma gondii is an opportunistic pathogenic protozoan parasite, which infects approximately one third of the human population worldwide, causing opportunistic zoonotic toxoplasmosis. The predilection of T. gondii for the central nervous system (CNS) causes behavioral disorders and fatal necrotizing encephalitis and thus constitutes a major threat especially to AIDS patients. Methods
In the present study, we explored the proteomic profiles of brain tissues of the specific pathogen-free (SPF) Kunming mice at 7 d, 14 d and 21 d after infection with cysts of the Toxoplasma gondii Prugniaud (PRU) strain (Genotype II), by two-dimensional gel electrophoresis (2-DE) combined with MALDI-TOF/TOF tandem mass spectrometry (MS/MS). Results
A total of 60 differentially expressed protein spots were selected. Fifty-six spots were successfully identified, which corresponded to 45 proteins of the mouse. Functional analysis using a Gene Ontology database showed that these proteins were mainly involved in metabolism, cell structure, signal transduction and immune responses, and will be beneficial for the understanding of molecular mechanisms of T. gondii pathogenesis. Conclusions
This study identified some mouse brain proteins involved in the response with cyst-forming T. gondii PRU strain. These results provided an insight into the responsive relationship between T. gondii and the host brain tissues, which will shed light on our understanding of the mechanisms of pathogenesis in toxoplasmic encephalitis, and facilitate the discovery of new methods of diagnosis, prevention, control and treatment of toxoplasmic encephalopathy
Enriching Phrases with Coupled Pixel and Object Contexts for Panoptic Narrative Grounding
Panoptic narrative grounding (PNG) aims to segment things and stuff objects
in an image described by noun phrases of a narrative caption. As a multimodal
task, an essential aspect of PNG is the visual-linguistic interaction between
image and caption. The previous two-stage method aggregates visual contexts
from offline-generated mask proposals to phrase features, which tend to be
noisy and fragmentary. The recent one-stage method aggregates only pixel
contexts from image features to phrase features, which may incur semantic
misalignment due to lacking object priors. To realize more comprehensive
visual-linguistic interaction, we propose to enrich phrases with coupled pixel
and object contexts by designing a Phrase-Pixel-Object Transformer Decoder
(PPO-TD), where both fine-grained part details and coarse-grained entity clues
are aggregated to phrase features. In addition, we also propose a PhraseObject
Contrastive Loss (POCL) to pull closer the matched phrase-object pairs and push
away unmatched ones for aggregating more precise object contexts from more
phrase-relevant object tokens. Extensive experiments on the PNG benchmark show
our method achieves new state-of-the-art performance with large margins.Comment: Accepted by IJCAI 202
Referring Image Segmentation via Cross-Modal Progressive Comprehension
Referring image segmentation aims at segmenting the foreground masks of the
entities that can well match the description given in the natural language
expression. Previous approaches tackle this problem using implicit feature
interaction and fusion between visual and linguistic modalities, but usually
fail to explore informative words of the expression to well align features from
the two modalities for accurately identifying the referred entity. In this
paper, we propose a Cross-Modal Progressive Comprehension (CMPC) module and a
Text-Guided Feature Exchange (TGFE) module to effectively address the
challenging task. Concretely, the CMPC module first employs entity and
attribute words to perceive all the related entities that might be considered
by the expression. Then, the relational words are adopted to highlight the
correct entity as well as suppress other irrelevant ones by multimodal graph
reasoning. In addition to the CMPC module, we further leverage a simple yet
effective TGFE module to integrate the reasoned multimodal features from
different levels with the guidance of textual information. In this way,
features from multi-levels could communicate with each other and be refined
based on the textual context. We conduct extensive experiments on four popular
referring segmentation benchmarks and achieve new state-of-the-art
performances.Comment: Accepted by CVPR 2020. Code is available at
https://github.com/spyflying/CMPC-Refse
Seroprevalence and Genetic Characterization of Toxoplasma Gondii in Three Species of Pet Birds in China
Background
Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common zoonosis worldwide, affecting a wide range of warm-blooded mammals and birds worldwide. However, no information on T. gondii infection in pet birds in China is available. Therefore, this study was performed to determine the prevalence of T. gondii infection in pet birds in Gansu province, China. Methods
A total of 687 blood samples were collected from pet birds (Carduelis spinus, Alauda gulgula, Cocothraustes migratorlus) in three representative administrative regions in Gansu province, northwest China between August 2011 and September 2012 T. gondii antibodies were determined using the modified agglutination test (MAT). Genomic DNA was extracted from the brain tissues of seropositive pet birds and T. gondii B1 gene was amplified using a semi-nested PCR.DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP. Results
The overall T. gondii seroprevalence was 11.21% (77/687). C. spinus had the highest T. gondii seroprevalence (11.65%), followed by A. arvensis (11.39%) and C. migratorlus (5.26%), these differences were not statistically significant (P \u3e 0.05). Of 77 DNA samples, 8 were positive for the T. gondii B1 gene, four showed complete genotyping results. Only one genotype (the Type II variant: ToxoDB genotype #3) was identified. Conclusions
The results of the present survey indicated the presence of T. gondii infection in pet birds in Gansu province, China. These data provide base-line information for the execution of control strategies against T. gondii infection in pet birds. To our knowledge, this is the first report documenting the occurrence of T. gondii prevalence and genotype in pet birds in China
Genetic characterization of \u3cem\u3eToxoplasma gondii\u3c/em\u3e from pigs from different localities in China by PCR-RFLP
Background
Toxoplasma gondii is a widely prevalent protozoan parasite that causes serious toxoplasmosis in humans and animals. The present study aimed to determine the genetic diversity of T. gondii isolates from pigs in Jiangxi, Sichuan, Guangdong Provinces and Chongqing Municipality in China using multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Methods
A total of 38 DNA samples were extracted from hilar lymph nodes of pigs with suspected toxoplasmosis, and were detected for the presence of T. gondii by semi-nested PCR of B1 gene. The positive DNA samples were typed at 11 genetic markers, including 10 nuclear loci, namely, SAG1, 5′-SAG2 and 3′-SAG2, alternative SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast locus Apico. Results
Twenty-five of the 38 DNA samples were T. gondii B1 gene positive. Complete genotyping data for all loci could be obtained for 17 of the 25 samples. Two genotypes were revealed (ToxoDB PCR-RFLP genotypes #9 and #3). Sixteen samples belong to genotype #9 which is the major lineage in mainland China and one sample belongs to genotype #3 which is Type II variant. Conclusions
To our knowledge, this is the first report of genetic typing of T. gondii isolates from pigs in Jiangxi, Sichuan Province and Chongqing Municipality, and the first report of ToxoDB #3 T. gondii from pigs in China. These results have implications for the prevention and control of foodborne toxoplasmosis in humans
SUN: Exploring Intrinsic Uncertainties in Text-to-SQL Parsers
This paper aims to improve the performance of text-to-SQL parsing by
exploring the intrinsic uncertainties in the neural network based approaches
(called SUN). From the data uncertainty perspective, it is indisputable that a
single SQL can be learned from multiple semantically-equivalent
questions.Different from previous methods that are limited to one-to-one
mapping, we propose a data uncertainty constraint to explore the underlying
complementary semantic information among multiple semantically-equivalent
questions (many-to-one) and learn the robust feature representations with
reduced spurious associations. In this way, we can reduce the sensitivity of
the learned representations and improve the robustness of the parser. From the
model uncertainty perspective, there is often structural information
(dependence) among the weights of neural networks. To improve the
generalizability and stability of neural text-to-SQL parsers, we propose a
model uncertainty constraint to refine the query representations by enforcing
the output representations of different perturbed encoding networks to be
consistent with each other. Extensive experiments on five benchmark datasets
demonstrate that our method significantly outperforms strong competitors and
achieves new state-of-the-art results. For reproducibility, we release our code
and data at https://github.com/AlibabaResearch/DAMO-ConvAI/tree/main/sunsql.Comment: Accepted at COLING 202
Genetic characterization of Toxoplasma gondii from Qinghai vole, Plateau pika and Tibetan ground-tit on the Qinghai-Tibet Plateau, China
Background
The distribution of genetic diversity of Toxoplasma gondii in wildlife is of interest to understand the transmission of this parasite in the environment. Limited information on T. gondii genotypes has been reported in wildlife in China. The objective of this study was to carry out the genetic characterization of T. gondii isolates from wild animals on the Qinghai-Tibet Plateau. Methods
Using PCR and multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology, we detected genetic diversity of T. gondii isolates from Qinghai vole, Plateau pika and Tibetan ground-tit in these regions. Results
In total, 183 brain tissues of different wild animals, including 48 Qinghai vole (Microtus fuscus), 101 Plateau pika (Ochotona curzoniae) and 34 Tibetan ground-tit (Pseudopodoces humilis), were tested for T. gondii infection. 11 of these were found to be positive for the T. gondii B1 gene by PCR amplification. These positive DNA samples were typed at 10 genetic markers, including 9 nuclear loci (SAG1, 5’-and 3’-SAG2, alternative SAG2, BTUB, GRA6, L358, PK1, c22-8, c29-2), and an apicoplast locus Apico. Six were successfully genotyped at eight or more genetic loci, and were grouped to three distinct genotypes. Four samples belonged to ToxoDB Genotype #10 and the other two samples were identified as two new genotypes (http://toxodb.org/toxo/ webcite). Conclusions
To our knowledge, this is the first report of genetic typing of T. gondii isolates in wildlife on the Qinghai-Tibet Plateau, China. The results show that there is a potential risk for the transmission of this parasite through the wildlife in this region.
doi:10.1186/1756-3305-6-29
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