59 research outputs found

    Cross-Attention in Coupled Unmixing Nets for Unsupervised Hyperspectral Super-Resolution

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    The recent advancement of deep learning techniques has made great progress on hyperspectral image super-resolution (HSI-SR). Yet the development of unsupervised deep networks remains challenging for this task. To this end, we propose a novel coupled unmixing network with a cross-attention mechanism, CUCaNet for short, to enhance the spatial resolution of HSI by means of higher-spatial-resolution multispectral image (MSI). Inspired by coupled spectral unmixing, a two-stream convolutional autoencoder framework is taken as backbone to jointly decompose MS and HS data into a spectrally meaningful basis and corresponding coefficients. CUCaNet is capable of adaptively learning spectral and spatial response functions from HS-MS correspondences by enforcing reasonable consistency assumptions on the networks. Moreover, a cross-attention module is devised to yield more effective spatial-spectral information transfer in networks. Extensive experiments are conducted on three widely-used HS-MS datasets in comparison with state-of-the-art HSI-SR models, demonstrating the superiority of the CUCaNet in the HSI-SR application. Furthermore, the codes and datasets will be available at: https://github.com/danfenghong/ECCV2020_CUCaNet

    Default Pathway of var2csa Switching and Translational Repression in Plasmodium falciparum

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    Antigenic variation is a subtle process of fundamental importance to the survival of a microbial pathogen. In Plasmodium falciparum malaria, PfEMP1 is the major variable antigen and adhesin expressed at the surface of the infected erythrocyte, which is encoded for by members of a family of 60 var-genes. Peri-nuclear repositioning and epigenetic mechanisms control their mono-allelic expression. The switching of PfEMP1 depends in part on variable transition rates and short-lived immune responses to shared minor epitopes. Here we show var-genes to switch to a common gene that is highly transcribed, but sparsely translated into PfEMP1 and not expressed at the erythrocyte surface. Highly clonal and adhesive P. falciparum, which expressed distinct var-genes and the corresponding PfEMP1s at onset, were propagated without enrichment or panning. The parasites successively and spontaneously switched to transcribe a shared var-gene (var2csa) matched by the loss of PfEMP1 surface expression and host cell-binding. The var2csa gene repositioned in the peri-nuclear area upon activation, away from the telomeric clusters and heterochromatin to transcribe spliced, full-length RNA. Despite abundant transcripts, the level of intracellular PfEMP1 was low suggesting post-transcriptional mechanisms to partake in protein expression. In vivo, off-switching and translational repression may constitute one pathway, among others, coordinating PfEMP1 expression

    Validity and reliability of Squegg device in measuring isometric handgrip strength

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    OBJECTIVE: The quantitative measurement of handgrip strength is important in assessing and charting the progress of patients with neuromuscular diseases. The aim of this research was to determine the intra-rater and inter-rater reliability and the validity of the Squegg digital dynamometer. SUBJECTS AND METHODS: Twenty-one females and nine male participants with an age range between 18 and 40 years volunteered for the study. Three testers each took three measurements with a Squegg device and a Jamar dynamometer using standardized measurement techniques. Intra- and inter-tester reliability were calculated using the intra-class correlation coefficient (ICC). To investigate the relationship between hand measures and isometric handgrip strength, the Pearson correlation coefficient test was used. To determine the agreement between the two devices, a Bland Altman plot was constructed, and the concurrent validity of Squegg was calculated. RESULTS: The intra-rater reliability coefficients for both Jamar and Squegg were greater than 0.99 for all three testers, indicating excellent intra-rater reliability. The inter-rater reliability of Jamar (ICC=0.93) and Squegg (ICC=0.87) was excellent. With an ICC of 0.844 and an r-value of 0.720, Squegg with Jamar demonstrates good validity and statistical significance (p=0.001). CONCLUSIONS: The isometric handgrip strength and hand measures showed a moderate correlation in the study population. The Squegg isometric handgrip dynamometer has good concurrent validity and great intra- and inter-rater reliability in healthy individuals. The validity of Squegg in patients with neuromuscular diseases that affect hand function has to be investigated further

    Seroprevalence of HHV-8, CMV, and EBV among the general population in Ghana, West Africa

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    <p>Abstract</p> <p>Background</p> <p>Human herpesvirus 8 (HHV-8), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are prevalent in Africa, but less common elsewhere and the modes of transmission are still subject to debate. Generally, they rarely cause disease in the immunocompetent host but are highly oncogenic when associated with immunosuppression. Although the high prevalence of HHV-8, CMV and EBV has been well documented in Africa, such data are sparse from Ghana.</p> <p>Methods</p> <p>Serum samples from 3275 HIV-seronegative healthy blood donors and 250 HIV-AIDS patients were tested for antibodies specific for HHV-8, CMV and EBV by IgG ELISA assays. Differences in seropositivity rates by gender and age were evaluated using the Chi-square test with Yates correction.</p> <p>Results</p> <p>Of the 3275 HIV-seronegative healthy blood donors tested, 2573 (78.6%) were males and 702 (21.4%) were females, with ages ranging from 18 to 65 years (median 32.6; mean 31.2; mode 30). Of the 250 HIV-AIDS patients tested, 140 (56%) were males and 110 (44%) were females, with ages ranging from 17 to 64 years (median 30.8; mean 30.3; mode 28). Among the HIV-seronegative healthy blood donors, overall seroprevalence of HHV-8, CMV and EBV was 23.7%, 77.6% and 20.0%, respectively. Among the HIV-AIDS patients, overall seroprevalence of HHV-8, CMV and EBV was 65.6%, 59.2% and 87.2%, respectively. The seroprevalence of HHV-8 (p < 0.005) and EBV (p < 0.001) was statistically significantly higher in HIV-AIDS patients compared to HIV-seronegative healthy blood donors. There was no statistically significant difference (p = 0.24) between CMV seroprevalence in HIV-AIDS patients and HIV-seronegative healthy blood donors. Age and gender were not independent determinants (p > 0.05) for all three infections among HIV-seronegative healthy blood donors and HIV-AIDS patients in Ghana.</p> <p>Conclusion</p> <p>The results presented herein indicate that HHV-8, CMV and EBV infections are hyperendemic in both HIV-seronegative and HIV-seropositive Ghanaians, and suggest primarily a horizontal route of transmission of these three viral infections in Ghana.</p

    The Plasmodium falciparum STEVOR Multigene Family Mediates Antigenic Variation of the Infected Erythrocyte

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    Modifications of the Plasmodium falciparum–infected red blood cell (iRBC) surface have been linked to parasite-associated pathology. Such modifications enable the parasite to establish long-lasting chronic infection by evading antibody mediate immune recognition and splenic clearance. With the exception of the well-demonstrated roles of var-encoded PfEMP1 in virulence and immune evasion, the biological significance of other variant surface antigens (rif and stevor) is largely unknown. While PfEMP1 and RIFIN have been located on the iRBC surface, recent studies have located STEVOR at the iRBC membrane where it may be exposed on the erythrocyte surface. To investigate the role of STEVOR in more detail, we have developed antibodies against two putative STEVOR proteins and used a combination of indirect immunofluorescence assays (IFA), live IFA, flow cytometry, as well as agglutination assays, which enable us to demonstrate that STEVOR is clonally variant at the surface of schizont stage parasites. Crucially, expression of different STEVOR on the surface of the iRBC changes the antigenic property of the parasite. Taken together, our data for the first time demonstrate that STEVOR plays a role in creating antigenic diversity of schizont stage parasites, thereby adding additional complexity to the immunogenic properties of the iRBC. Furthermore, it clearly demonstrates that to obtain a complete understanding of how parasite-induced pathology is linked to variation on the surface of the iRBC, focusing the interactions of multiple multigene families needs to be considered

    clag9 Is Not Essential for PfEMP1 Surface Expression in Non-Cytoadherent Plasmodium falciparum Parasites with a Chromosome 9 Deletion

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    BACKGROUND: The expression of the clonally variant virulence factor PfEMP1 mediates the sequestration of Plasmodium falciparum infected erythrocytes in the host vasculature and contributes to chronic infection. Non-cytoadherent parasites with a chromosome 9 deletion lack clag9, a gene linked to cytoadhesion in previous studies. Here we present new clag9 data that challenge this view and show that surface the non-cytoadherence phenotype is linked to the expression of a non-functional PfEMP1. METHODOLOGY/PRINCIPAL FINDINGS: Loss of adhesion in P. falciparum D10, a parasite line with a large chromosome 9 deletion, was investigated. Surface iodination analysis of non-cytoadherent D10 parasites and COS-7 surface expression of the CD36-binding PfEMP1 CIDR1α domain were performed and showed that these parasites express an unusual trypsin-resistant, non-functional PfEMP1 at the erythrocyte surface. However, the CIDR1α domain of this var gene expressed in COS-7 cells showed strong binding to CD36. Atomic Force Microscopy showed a slightly modified D10 knob morphology compared to adherent parasites. Trafficking of PfEMP1 and KAHRP remained functional in D10. We link the non-cytoadherence phenotype to a chromosome 9 breakage and healing event resulting in the loss of 25 subtelomeric genes including clag9. In contrast to previous studies, knockout of the clag9 gene from 3D7 did not interfere with parasite adhesion to CD36. CONCLUSIONS/SIGNIFICANCE: Our data show the surface expression of non-functional PfEMP1 in D10 strongly indicating that genes other than clag9 deleted from chromosome 9 are involved in this virulence process possibly via post-translational modifications

    The Cysteine-Rich Interdomain Region from the Highly Variable Plasmodium falciparum Erythrocyte Membrane Protein-1 Exhibits a Conserved Structure

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    Plasmodium falciparum malaria parasites, living in red blood cells, express proteins of the erythrocyte membrane protein-1 (PfEMP1) family on the red blood cell surface. The binding of PfEMP1 molecules to human cell surface receptors mediates the adherence of infected red blood cells to human tissues. The sequences of the 60 PfEMP1 genes in each parasite genome vary greatly from parasite to parasite, yet the variant PfEMP1 proteins maintain receptor binding. Almost all parasites isolated directly from patients bind the human CD36 receptor. Of the several kinds of highly polymorphic cysteine-rich interdomain region (CIDR) domains classified by sequence, only the CIDR1α domains bind CD36. Here we describe the CD36-binding portion of a CIDR1α domain, MC179, as a bundle of three α-helices that are connected by a loop and three additional helices. The MC179 structure, containing seven conserved cysteines and 10 conserved hydrophobic residues, predicts similar structures for the hundreds of CIDR sequences from the many genome sequences now known. Comparison of MC179 with the CIDR domains in the genome of the P. falciparum 3D7 strain provides insights into CIDR domain structure. The CIDR1α three-helix bundle exhibits less than 20% sequence identity with the three-helix bundles of Duffy-binding like (DBL) domains, but the two kinds of bundles are almost identical. Despite the enormous diversity of PfEMP1 sequences, the CIDR1α and DBL protein structures, taken together, predict that a PfEMP1 molecule is a polymer of three-helix bundles elaborated by a variety of connecting helices and loops. From the structures also comes the insight that DBL1α domains are approximately 100 residues larger and that CIDR1α domains are approximately 100 residues smaller than sequence alignments predict. This new understanding of PfEMP1 structure will allow the use of better-defined PfEMP1 domains for functional studies, for the design of candidate vaccines, and for understanding the molecular basis of cytoadherence

    Supply and protected different population of Litopenaeus vannamei subadult zero foster (F0) from difference provinces Iran

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    Nowadays, Litopenaeus vannamei are the most important species of farmed penaeidae shrimp in the world that is rapidly replacing native species in areas aquaculture. Due to demand increase for this species culture, shrimp displacement to different areas may be associated with some potential pathogens transferred to new areas farmed. Therefore, in this study were prepared bi-osecurity conditions for specific disease-free production of L. vannamei. Thereafter, three populations (Molokaei, High health and mix of Molokaei and High health) of the shrimp various reserves were detected base on origin and genetic indexes such as: observed heterozygosity, expected heterozygosity, allele frequency, coefficient inbreeding, genetic differentiation, genetic distance and genetic identity. On the other hand, epidemiological studies indicate non pathogens (viral, bacterial, fungal and parasitic) recognition of different populations selected in the quarantine salon. The bioassay results showed that the average weight and length of the populations of High health and Mix significantly greater than was a population of Molokaei. The shrimp populations were stocked in fiberglass tank (five ton) and were kept separated in the quarantine salon. During maintenance shrimp of populations in the quarantine salon were evaluated living and non-living pathogens with PCR, microbiology and biochemical methods. There is not any pathogens detection from shrimp populations stocking in the quarantine salon, so the shrimps were carried over to pond for broodstock culture of specific pathogenic free

    National Clinical Guidelines for non-surgical treatment of patients with recent onset low back pain or lumbar radiculopathy

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    Small-molecule inhibitor of OGG1 suppresses pro-inflammatory gene expression and inflammation

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    The onset of inflammation is associated with reactive oxygen species and oxidative damage to macromolecules like 7,8-dihydro-8-oxoguanine (8-oxoG) in DNA. Because 8-oxoguanine DNA glycosylase 1 (OGG1) binds 8-oxoG and because Ogg1-deficient mice are resistant to acute and systemic inflammation, we hypothesized that OGG1 inhibition may represent a strategy for the prevention and treatment of inflammation. We developed TH5487, a selective active-site inhibitor of OGG1, which hampers OGG1 binding to and repair of 8-oxoG and which is well tolerated by mice. TH5487 prevents tumor necrosis factor–α–induced OGG1-DNA interactions at guanine-rich promoters of proinflammatory genes. This, in turn, decreases DNA occupancy of nuclear factor κB and proinflammatory gene expression, resulting in decreased immune cell recruitment to mouse lungs. Thus, we present a proof of concept that targeting oxidative DNA repair can alleviate inflammatory conditions in vivo
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