Perturbations of the ileal mycobiota by necrotic enteritis in broiler chickens

Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This study was aimed to examine the association between the intestinal mycobiota and the severity of necrotic enteritis(NE),an economically significant poultry disease.Methods:A total of 90 day-of-hatch Cobb broilers were infected with Eimeria maxima on d 10,followed by an oral challenge with C.perfringens on d 14 to induce NE,while another 10 broilers were served as mock-infected controls.On d 17,the lesions in the jejunum were scored,and the ileal digesta were subjected to DNA isolation and real-time PCR quantification of total bacterial and fungi populations.Internal transcribed spacer 2(ITS2)amplicon sequencing was also performed to profile the ileal mycobiota composition.Changes in the ileal mycobiota in response to NE were investigated.Spearman correlation analysis was further conducted to identify the correlations between relative abundances of individual ileal fungi and the severity of NE.Results:While the total bacterial population in the ileum was increased by 2-to 3-fold in NE chickens,the total fungal population was progressively declined in more exacerbated NE,with the most severely infected chickens showing a nearly 50-fold reduction relative to mock-infected controls.Richness of the ileal mycobiota also tended to reduce in chickens with NE(P=0.06).Compositionally,among 30 most abundant fungal amplicon sequence variants(ASVs),11 were diminished and 7 were enriched(P<0.05),while 12 remained largely unchanged in NEafflicted chickens(P>0.05).Multiple Wallemia and Aspergillus species were markedly diminished in NE(P<0.05)and also showed a significant negative correlation with NE severity(P<0.05).Conclusions:Dysbiosis of the ileal mycobiota is induced evidently by NE and the extent of the dysbiosis is positively correlated with disease severity.These findings suggest a possible role of the intestinal mycobiota in NE pathogenesis and highlight the mycobiota as a new potential target for NE mitigation in poultry.

Towards POI-based large-scale land use modeling: spatial scale, semantic granularity, and geographic context

The combination of spatial distribution,semantic characteristics,and sometimes temporal dynamics of POIs inside a geographic region can capture its unique land use characteristics.Most previous studies on POI-based land use modeling research focused on one geographic region and select one spatial scale and semantic granularity for land use characterization.There is a lack of understanding on the impact of spatial scale,semantic granularity,and geographic context on POI-based land use modeling,particularly large-scale land use modeling.In this study,we developed a scalable POI-based land use modeling framework and examined the impact of these three factors on POI-based land use characterization using data from three geographic regions.We developed a unified semantic representation framework for POI semantics that can help fuse heterogeneous POI data sources.Then,by combining POIs with a neural network language model,we developed a spatially explicit approach to learn the embedding representation of POIs and AOIs.We trained multiple supervised classifiers using AOI embeddings as input features to predict AOI land use at different semantic granularities.The classification performance of different land use classes was analyzed and compared across three geographic regions to identify the semantic representativeness of POI-based AOI embedding and the impact of geographic context.

Secure Inverted Index Based Search over Encrypted Cloud Data with User Access Rights Management

Cloud computing is a technology that provides users with a large storage space and an enormous computing power.However,the outsourced data are often sensitive and confidential,and hence must be encrypted before being outsourced.Consequently,classical search approaches have become obsolete and new approaches that are compatible with encrypted data have become a necessity.For privacy reasons,most of these approaches are based on the vector model which is a time consuming process since the entire index must be loaded and exploited during the search process given that the query vector must be compared with each document vector.To solve this problem,we propose a new method for constructing a secure inverted index using two key techniques,homomorphic encryption and the dummy documents technique.However,1)homomorphic encryption generates very large ciphertexts which are thousands of times larger than their corresponding plaintexts,and 2)the dummy documents technique that enhances the index security produces lots of false positives in the search results.The proposed approach exploits the advantages of these two techniques by proposing two methods called the compressed table of encrypted scores and the double score formula.Moreover,we exploit a second secure inverted index in order to manage the users'access rights to the data.Finally,in order to validate our approach,we performed an experimental study using a data collection of one million documents.The experiments show that our approach is many times faster than any other approach based on the vector model.

Research on End-to-End Encryption of TETRA

The Terrestrial Trunked Radio（TETRA） system uses end-to-end encryption in addition to the air interface encryption to provide enhanced security. The TETRA system uses a synchronization technique known as frame stealing to provide synchronization of end-to-end encrypted data. However, the frame stealing process degrades the quality of video. This paper proposes an end-to-end encryption system with the frame stealing technique for voice and frame insertion for video. A block cipher in the output feedback mode is used to implement the end-to-end key stream generator. Moreover. In the Short Data Service（SDS） message encryption , a block cipher in the Cipher Block Chaining （CBC） mode is used to calculate the cryptographically secure checksum, which is sufficient to certify the integrity.