201 research outputs found
Formation and transportation of sand-heap in an inclined and vertically vibrated container
We report the experimental findings of formation and motion of heap in
granular materials in an inclined and vertically vibrated container. We show
experimentally how the transport velocity of heap up container is related to
the driving acceleration as well as the driving frequency of exciter. An
analogous experiment was performed with a heap-shaped Plexiglas block. We
propose that cohesion force resulted from pressure gradient in ambient gas
plays a crucial role in enhancing and maintaining a heap, and ratchet effect
causes the movement of the heap. An equation which governs the transport
velocity of the heap is presented.Comment: 9 pages, 5 figures, submitted to PR
Metagenome Plasticity of the Bovine Abomasal Microbiota in Immune Animals in Response to Ostertagia Ostertagi Infection
Infections in cattle by the abomasal nematode Ostertagia ostertagi result in impaired gastrointestinal function. Six partially immune animals were developed using multiple drug-attenuated infections, and these animals displayed reduced worm burdens and a slightly elevated abomasal pH upon reinfection. In this study, we characterized the abomasal microbiota in response to reinfection using metagenomic tools. Compared to uninfected controls, infection did not induce a significant change in the microbial community composition in immune animals. 16S rRNA gene-based phylogenetic analysis identified 15 phyla in the bovine abomasal microbiota with Bacteroidetes (60.5%), Firmicutes (27.1%), Proteobacteria (7.2%), Spirochates (2.9%), and Fibrobacteres (1.5%) being the most predominant. The number of prokaryotic genera and operational taxonomic units (OTU) identified in the abomasal microbial community was 70.8±19.8 (mean ± SD) and 90.3±2.9, respectively. However, the core microbiome comprised of 32 genera and 72 OTU. Infection seemingly had a minimal impact on the abomasal microbial diversity at a genus level in immune animals. Proteins predicted from whole genome shotgun (WGS) DNA sequences were assigned to 5,408 Pfam and 3,381 COG families, demonstrating dazzling arrays of functional diversity in bovine abomasal microbial communities. However, none of COG functional classes were significantly impacted by infection. Our results demonstrate that immune animals may develop abilities to maintain proper stability of their abomasal microbial ecosystem. A minimal disruption in the bovine abomasal microbiota by reinfection may contribute equally to the restoration of gastric function in immune animals
Evaluation of the performance of a dengue outbreak detection tool for China
An outbreak detection and response system, using time series moving percentile method based on historical data, in China has been used for identifying dengue fever outbreaks since 2008. For dengue fever outbreaks reported from 2009 to 2012, this system achieved a sensitivity of 100%, a specificity of 99.8% and a median time to detection of 3 days, which indicated that the system was a useful decision tool for dengue fever control and risk-management programs in China.This work was supported by the grants from Research and Promotion of Key Technology on Health Emergency Preparation and Dispositions (201202006), the National Key Science and Technology Project on Infectious Disease Surveillance Technique Platform of China (2012ZX10004-201) and Development of Early Warning Systems for Dengue Fever Based on Socio-ecological Factors (NHMRC APP1002608)
Faraday instability on viscous ferrofluids in a horizontal magnetic field: Oblique rolls of arbitrary orientation
A linear stability analysis of the free surface of a horizontally unbounded
ferrofluid layer of arbitrary depth subjected to vertical vibrations and a
horizontal magnetic field is performed. A nonmonotonic dependence of the
stability threshold on the magnetic field is found at high frequencies of the
vibrations. The reasons of the decrease of the critical acceleration amplitude
caused by a horizontal magnetic field are discussed. It is revealed that the
magnetic field can be used to select the first unstable pattern of Faraday
waves. In particular, a rhombic pattern as a superposition of two different
oblique rolls can occur. A scaling law is presented which maps all data into
one graph for the tested range of viscosities, frequencies, magnetic fields and
layer thicknesses.Comment: 8 pages, 6 figures, RevTex
Decreased levels of BAG3 in a family with a rare variant and in idiopathic dilated cardiomyopathy.
The most common cause of dilated cardiomyopathy and heart failure (HF) is ischemic heart disease; however, in a third of all patients the cause remains undefined and patients are diagnosed as having idiopathic dilated cardiomyopathy (IDC). Recent studies suggest that many patients with IDC have a family history of HF and rare genetic variants in over 35 genes have been shown to be causative of disease. We employed whole-exome sequencing to identify the causative variant in a large family with autosomal dominant transmission of dilated cardiomyopathy. Sequencing and subsequent informatics revealed a novel 10-nucleotide deletion in the BCL2-associated athanogene 3 (BAG3) gene (Ch10:del 121436332_12143641: del. 1266_1275 [NM 004281]) that segregated with all affected individuals. The deletion predicted a shift in the reading frame with the resultant deletion of 135 amino acids from the C-terminal end of the protein. Consistent with genetic variants in genes encoding other sarcomeric proteins there was a considerable amount of genetic heterogeneity in the affected family members. Interestingly, we also found that the levels of BAG3 protein were significantly reduced in the hearts from unrelated patients with end-stage HF undergoing cardiac transplantation when compared with non-failing controls. Diminished levels of BAG3 protein may be associated with both familial and non-familial forms of dilated cardiomyopathy
Human cytomegalovirus evades antibody-mediated immunity through endoplasmic reticulum-associated degradation of the FcRn receptor
Partial funding for Open Access provided by the UMD Libraries' Open Access Publishing Fund.Human cytomegalovirus (HCMV) can persistently infect humans, but how HCMV avoids
humoral immunity is not clear. The neonatal Fc receptor (FcRn) controls IgG transport from
the mother to the fetus and prolongs IgG half-life. Here we show that US11 inhibits the
assembly of FcRn with β2m and retains FcRn in the endoplasmic reticulum (ER), consequently
blocking FcRn trafficking to the endosome. Furthermore, US11 recruits the ubiquitin enzymes
Derlin-1, TMEM129 and UbE2J2 to engage FcRn, consequently initiating the dislocation of
FcRn from the ER to the cytosol and facilitating its degradation. Importantly, US11 inhibits IgGFcRn
binding, resulting in a reduction of IgG transcytosis across intestinal or placental epithelial
cells and IgG degradation in endothelial cells. Hence, these results identify the
mechanism by which HCMV infection exploits an ER-associated degradation pathway
through US11 to disable FcRn functions. These results have implications for vaccine development
and immune surveillance
On the security of arbitrated quantum signature schemes
Due to potential capability of providing unconditional security, arbitrated
quantum signature (AQS) schemes, whose implementation depends on the
participation of a trusted third party, received intense attention in the past
decade. Recently, some typical AQS schemes were cryptanalyzed and improved. In
this paper, we analyze security property of some AQS schemes and show that all
the previous AQS schemes, no matter original or improved, are still insecure in
the sense that the messages and the corresponding signatures can be exchanged
among different receivers, allowing the receivers to deny accepting the
signature of an appointed message. Some further improvement methods on the AQS
schemes are also discussed.Comment: 4 pages, no figure
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