130 research outputs found
A study on the trend of Global language Development
Inpart paper, by considering the data of population, economy, national policy from 2000 to 2015, we adapt Principal component analysis to quantify the data to find out the influence factors. We establish the Virus Infection model to predict the language users within 50 years. We get that Chinese, Spanish, English, India language and other languages will become the top ten languages in the next 50 years
VommaNet: an End-to-End Network for Disparity Estimation from Reflective and Texture-less Light Field Images
The precise combination of image sensor and micro-lens array enables lenslet
light field cameras to record both angular and spatial information of incoming
light, therefore, one can calculate disparity and depth from light field
images. In turn, 3D models of the recorded objects can be recovered, which is a
great advantage over other imaging system. However, reflective and texture-less
areas in light field images have complicated conditions, making it hard to
correctly calculate disparity with existing algorithms. To tackle this problem,
we introduce a novel end-to-end network VommaNet to retrieve multi-scale
features from reflective and texture-less regions for accurate disparity
estimation. Meanwhile, our network has achieved similar or better performance
in other regions for both synthetic light field images and real-world data
compared to the state-of-the-art algorithms. Currently, we achieve the best
score for mean squared error (MSE) on HCI 4D Light Field Benchmark
HSAF-induced antifungal effects in Candida albicans through ROS-mediated apoptosis
Heat-stable antifungal factor (HSAF) belongs to polycyclic tetramate macrolactams (PTMs), which inhibits many fungal pathogens and is effective in inhibiting Candida albicans (C. albicans). In this study, we found that HSAF induced the apoptosis of C. albicans SC5314 through inducing the production of reactive oxygen species (ROS). Nevertheless, we validated the efficacy of HSAF against candidiasis caused by C. albicans in a murine model in vivo,and HSAF significantly improved survival and reduced fungal burden compared to vehicles. A molecular dynamics (MD) simulation was also investigated, revealing the theoretical binding mode of HSAF to the β-tubulin of C. albicans. This study first found PTMs-induced fungal apoptosis through ROS accumulation in C. albicans and its potential as a novel agent for fungicides
ACID: Abstractive, Content-Based IDs for Document Retrieval with Language Models
Generative retrieval (Wang et al., 2022; Tay et al., 2022) is a new approach
for end-to-end document retrieval that directly generates document identifiers
given an input query. Techniques for designing effective, high-quality document
IDs remain largely unexplored. We introduce ACID, in which each document's ID
is composed of abstractive keyphrases generated by a large language model,
rather than an integer ID sequence as done in past work. We compare our method
with the current state-of-the-art technique for ID generation, which produces
IDs through hierarchical clustering of document embeddings. We also examine
simpler methods to generate natural-language document IDs, including the naive
approach of using the first k words of each document as its ID or words with
high BM25 scores in that document. We show that using ACID improves top-10 and
top-20 accuracy by 15.6% and 14.4% (relative) respectively versus the
state-of-the-art baseline on the MSMARCO 100k retrieval task, and 4.4% and 4.0%
respectively on the Natural Questions 100k retrieval task. Our results
demonstrate the effectiveness of human-readable, natural-language IDs in
generative retrieval with LMs. The code for reproducing our results and the
keyword-augmented datasets will be released on formal publication
TimeSQL: Improving Multivariate Time Series Forecasting with Multi-Scale Patching and Smooth Quadratic Loss
Time series is a special type of sequence data, a sequence of real-valued
random variables collected at even intervals of time. The real-world
multivariate time series comes with noises and contains complicated local and
global temporal dynamics, making it difficult to forecast the future time
series given the historical observations. This work proposes a simple and
effective framework, coined as TimeSQL, which leverages multi-scale patching
and smooth quadratic loss (SQL) to tackle the above challenges. The multi-scale
patching transforms the time series into two-dimensional patches with different
length scales, facilitating the perception of both locality and long-term
correlations in time series. SQL is derived from the rational quadratic kernel
and can dynamically adjust the gradients to avoid overfitting to the noises and
outliers. Theoretical analysis demonstrates that, under mild conditions, the
effect of the noises on the model with SQL is always smaller than that with
MSE. Based on the two modules, TimeSQL achieves new state-of-the-art
performance on the eight real-world benchmark datasets. Further ablation
studies indicate that the key modules in TimeSQL could also enhance the results
of other models for multivariate time series forecasting, standing as
plug-and-play techniques
Iterative Assembly of Two Separate Polyketide Chains by the Same Single-module Bacterial Polyketide Synthase in the Biosynthesis of HSAF
HSAF (1) was isolated from the biocontrol agent Lysobacter enzymogenes (Figure 1).[1-4]
This bacterial metabolite belongs to polycyclic tetramate macrolactams (PTM) that are
emerging as a new class of natural products with distinct structural features. [5, 6] HSAF
exhibits a potent antifungal activity and shows a novel mode of action.[1-4] The HSAF
biosynthetic gene cluster contains only a single-module hybrid polyketide synthasenonribosomal
peptide synthetase (PKS-NRPS), although the PTM scaffold is apparently
derived from two separate hexaketide chains and an ornithine residue.[1-4] This suggests that
the same PKS module would act not only iteratively, but also separately, in order to link the
two hexaketide chains with the NRPS-activated ornithine to form the characteristic PTM
scaffold. Recently, the Gulder group reported heterologous expression of the ikarugamycin
(4) biosynthetic gene cluster in E. coli,[7] and the Zhang group reported the enzymatic
mechanism for formation of the inner 5-memebered ring and demonstrated the polyketide
origin of the ikarugamycin skeleton.[8] Ikarugamycin is a Streptomyces-derived PTM which
has a 5,6,5-tricyclic system (Figure 1). Both the Gulder and Zhang groups showed that a
three-gene cluster is sufficient for ikarugamycin biosynthesis. Despite the progress, this
iterative polyketide biosynthetic mechanism had not been demonstrated using purified PKS
and NRPS. In addition, HSAF has a 5,5,6-tricyclic system, and its gene cluster contains at
least six genes.[3] Finally, unlike most PTM compounds, HSAF is produced by a Gramnegative
bacterium, L. enzymogenes. Here, we report the heterologous production of HSAF
analogs in Gram-positive Streptomyces hosts, in which the native PKS have been deleted.
We also obtained evidence for the formation of the polyene tetramate intermediate in
Streptomyces when only the single-module hybrid PKS-NRPS gene was expressed. Finally,
we showed the in vitro production of the polyene tetramate using the individually purified
PKS and NRPS. The results provide direct evidence for this iterative polyketide biosynthetic
mechanism that is likely general for the PTM-type hybrid polyketide-peptides
Mesenteric CD103+DCs Initiate Switched Coxsackievirus B3 VP1-Specific IgA Response to Intranasal Chitosan-DNA Vaccine Through Secreting BAFF/IL-6 and Promoting Th17/Tfh Differentiation
Intranasal chitosan-formulated DNA vaccination promotes IgA secretion in the intestine. However, the mechanism whereby chitosan-DNA skews IgA class switch recombination (CSR) of B cells in the Gut-associated lymph tissue (GALT) is not fully resolved. In this study, we investigated the effects of nasally administered chitosan-DNA (pcDNA3.1-VP1 plasmid encoding VP1 capsid protein of Coxsackievirus B3) on IgA production, DC activation and Tfh/Th17 response in the intestine. Compared to DNA immunization, intranasal chitosan-DNA vaccination induced antigen-specific IgA production in feces, a pronounced switching of antigen-specific IgA+ plasmablast B cells in the mesenteric lymph nodes (MLNs) and an enhanced expression of post-recombination Iα-CH transcripts/IgA germline transcript (αGT) as well as activation-induced cytidine deaminase (AID) in MLN B cells. MLN Tfh frequency was markedly enhanced by chitosan-DNA, and was associated with VP1-specific IgA titer. 24 h after immunization, intranasal chitosan-DNA induced a recruitment of CD103+DCs into the MLN that paralleled a selective loss of CD103+DCs in the lamina propria (LP). In vivo activated MLN-derived CD103+DCs produced high levels of IL-6 and BAFF in response to chitosan-DNA, which up-regulated transmembrane activator and CAML interactor (TACI) expression on MLN B cells. Upon co-culture with IgM+B in the presence of chitosan-DNA, MLN CD103+DCs induced IgA production in a T-dependent manner; and this IgA-promoting effect of CD103+DC was blocked by targeting TACI and, to a lower extent, by blocking IL-6. MLN CD103+DCs displayed an enhanced capacity to induce an enhanced CD4+Th17 response in vivo and in vitro, and IL-17A deficient mice had a pronounced reduction of specific intestinal IgA following immunization. Taken together, mesenteric CD103+DCs are indispensable for the adjuvant activity of chitosan in enhancing DNA vaccine-specific IgA switching in gut through activating BAFF-TACI and IL-6-IL-6R signaling, and through inducing Th17/Tfh differentiation in the MLN
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