Genome-wide identification of new reference genes for RT-qPCR normalization in CGMMV-infected Lagenaria siceraria

Lagenaria siceraria is an economically important cucurbitaceous crop, but suitable reference genes (RGs) to use when the plants are infected by cucumber green mottle mosaic virus (CGMMV) have not been determined. Sixteen candidate RGs of both leaf and fruit and 18 candidate RGs mostly from separate RNA-Seq datasets of bottle gourd leaf or fruit were screened and assessed by RT-qPCR. The expression stability of these genes was determined and ranked using geNorm, NormFinder, BestKeeper and RefFinder. Comprehensive analysis resulted in the selection of LsCYP, LsH3, and LsTBP as the optimal RGs for bottle gourd leaves, and LsP4H, LsADP, and LsTBP for fruits. LsWD, LsGAPDH, and LsH3 were optimal for use in both leaves and fruits under the infection of CGMMV. Isopentenyl transferase (IPT) and DNA-directed RNA polymerase (DdRP) were used to validate the applicability of the most stable identified RGs from bottle gourd in response to CGMMV. All the candidate RGs performed in RT-qPCR consistently with the data from the transcriptome database. The results demonstrated that LsWD, LsGAPDH and LsH3 were the most suitable internal RGs for the leaf, and LsH3, LsGAPDH, LsP4H and LsCYP for the fruit

A Novel Data-Driven Evaluation Framework for Fork after Withholding Attack in Blockchain Systems

In the blockchain system, mining pools are popular for miners to work collectively and obtain more revenue. Nowadays, there are consensus attacks that threaten the efficiency and security of mining pools. As a new type of consensus attack, the Fork After Withholding (FAW) attack can cause huge economic losses to mining pools. Currently, there are a few evaluation tools for FAW attacks, but it is still difficult to evaluate the FAW attack protection capability of target mining pools. To address the above problem, this paper proposes a novel evaluation framework for FAW attack protection of the target mining pools in blockchain systems. In this framework, we establish the revenue model for mining pools, including honest consensus revenue, block withholding revenue, successful fork revenue, and consensus cost. We also establish the revenue functions of target mining pools and other mining pools, respectively. In particular, we propose an efficient computing power allocation optimization algorithm (CPAOA) for FAW attacks against multiple target mining pools. We propose a model-solving algorithm based on improved Aquila optimization by improving the selection mechanism in different optimization stages, which can increase the convergence speed of the model solution and help find the optimal solution in computing power allocation. Furthermore, to greatly reduce the possibility of falling into local optimal solutions, we propose a solution update mechanism that combines the idea of scout bees in an artificial bee colony optimization algorithm and the constraint of allocating computing power. The experimental results show that the framework can effectively evaluate the revenue of various mining pools. CPAOA can quickly and accurately allocate the computing power of FAW attacks according to the computing power of the target mining pool. Thus, the proposed evaluation framework can effectively help evaluate the FAW attack protection capability of multiple target mining pools and ensure the security of the blockchain system

Comparison study on life-cycle costs of different trams powered by fuel cell systems and others

Proton exchange membrane fuel cells have shown great promise for powering trams. Hydrogen refueling stations and a fuel-cell system incur initial vehicle costs that are higher than a pantograph/catenary tram or contact-rail tram. In this paper, a life-cycle cost analysis is conducted for five trams: a pantograph/catenary tram, a contact-rail tram, and three fuel-cell hybrid trams. Characteristics of fuel-cell hybrid trams are compared with contemporary transit systems. A simplified life-cycle cost model, including costs for the initial infrastructure and powertrains, daily operation and power plant replacement, is proposed and calculated with parameters. A sensitivity analysis is also performed. Results show that the life-cycle costs of trams are almost proportional to the rail-line length. The initial costs of a fuel-cell hybrid tram are less than a pantograph/catenary tram or contact-rail tram. The life-cycle costs of fuel-cell hybrid trams are highly dependent on combination factors of hydrogen price, fuel-cell price and battery price. Charging facilities for fuel-cell hybrid trams are favorable when hydrogen price is in a high level. Greenhouse gas emissions of trams are almost equivalent

Identification and complete genome sequence of iris potyvirus A, which causes dwarfing and foliar chlorosis with mosaic or mottle disease symptoms on lily (Lilium lancifolium Thunb.) in China

Lily plants (Lilium lancifolium Thunb.) exhibiting dwarfing and foliar chlorosis with mosaic or mottle disease symptoms were found in Anhui Province, China. We used high-throughput sequencing of small RNA to survey the virus in the lily cultivation region of Anhui Province. Here, we report the identification and complete genome sequence of the viral agent. It contains 9733 nucleotides, excluding the poly(A) tail, and encodes a polyprotein of 3063 amino acids. The complete polyprotein ORF shows 98.92% amino acid sequence identity with that of iris potyvirus A (GenBank MH898493). Phylogenetic analysis of coat protein sequences placed the viral agent close to members of the genus Potyvirus in the family Potyviridae, and it was therefore provisionally named iris potyvirus A isolate Anhui (IrPVA-Anhui). This is the first complete genome sequence of IrPVA-Anhui from lily plant, for which only a partial sequence from Iris domestica has been reported previously. Comparative analysis of this genome sequence with those of closely related potyviruses identified nine cleavage sites and the conserved motifs typical of potyviruses. Subsequent virus identification was performed using serological assays (ELISA and antibody-based lateral flow assays), molecular methods (RT-PCR), and a pathogenicity test. Virus particles with a length of about 700 nm, similar to viruses in the genus Potyvirus, were observed via transmission electron microscope (TEM). We back-inoculated healthy plants of multiple species to investigate the host range of the virus. It infected the original host, Iris domestica, and Nicotiana benthamiana but not Triticum aestivum, Pisum sativum, Chenopodium amaranticolor, or Datura stramonium. This is the first report of natural IrPVA-Anhui infection of lily plants in China, providing a scientific basis for IrPVA-Anhui control in future lily plantings

Genetic characteristics of

Giardia duodenalis is an important zoonotic pathogen for both human and animal health. Although there have been reports on G. duodenalis infections in animals all over the world, information regarding the prevalence and genetic characteristics of G. duodenalis in sheep in Inner Mongolia, China, is limited. In this study, 209 sheep fecal specimens were collected in this autonomous region. We established that the prevalence of G. duodenalis was 64.11% (134/209), as determined using nested PCR detection and sequences analysis of the small subunit ribosomal RNA (SSU rRNA) gene. Based on the beta-giardin (bg) locus, the glutamate dehydrogenase (gdh) locus, and the triose phosphate isomerase (tpi) locus to study genetic characteristics, both assemblages A (2.99%, 4/134) and E (97.01%, 130/134) were found. Five novel nucleotide sequence of assemblage E were detected, two at the bg locus, two at the gdh locus, and one at the tpi locus. Multilocus genotyping yielded four assemblage E and two assemblage A multilocus genotypes (MLGs), including four novel assemblage E MLGs and one novel assemblage A MLG. Results of this study indicated that G. duodenalis was highly prevalent in sheep in Inner Mongolia. This study is the first to use the multilocus genotyping approach to identify G. duodenalis in sheep from this region

Different virus-derived siRNAs profiles between leaves and fruits in Cucumber green mottle mosaic virus-infected Lagenaria siceraria

RNA silencing is an evolutionarily conserved antiviral mechanism, through which virus-derived small interfering RNAs (vsiRNAs) playing roles in host antiviral defence are produced in virus-infected plant. Deep sequencing technology has revolutionized the study on the interaction between virus and plant host through the analysis of vsiRNAs profile. However, comparison of vsiRNA profiles in different tissues from a same host plant has been rarely reported. In this study, the profiles of virus-derived small interfering RNAs (vsiRNAs) from leaves and fruits of Lagenaria siceraria plants infected with Cucumber green mottle mosaic virus (CGMMV) were comprehensively characterized and compared. Many more vsiRNAs were present in infected leaves than in fruits. vsiRNAs from both leaves and fruits were mostly 21- and 22-nt in size as previously described in other virus-infected plants. Interestingly, vsiRNAs were predominantly produced from the viral positive strand RNAs in infected leaves, whereas in infected fruits they were derived equally from the positive and negative strands. Many leaf-specific positive vsiRNAs with lengths of 21-nt (2,058) or 22-nt (3,996) were identified but only six (21-nt) and one (22-nt) positive vsiRNAs were found to be specific to fruits. vsiRNAs hotspots were only present in the 5’-terminal and 3’-terminal of viral positive strand in fruits, while multiple hotspots were identified in leaves. Differences in GC content and 5'-terminal nucleotide of vsiRNAs were also observed in the two organs. To our knowledge, this provides the first high-resolution comparison of vsiRNA profiles between different tissues of the same host plant