Coordination between terminal variation of the viral genome and insect microRNAs regulates rice stripe virus replication in insect vectors

Maintenance of a balance between the levels of viral replication and selective pressure from the immune systems of insect vectors is one of the prerequisites for efficient transmission of insect-borne propagative phytoviruses. The mechanism regulating the adaptation of RNA viruses to insect vectors by genomic variation remains unknown. Our previous study demonstrated an extension of the 3’-untranslated terminal region (UTR) of two genomic segments of rice stripe virus (RSV). In the present study, a reverse genetic system for RSV in human cells and an insect vector, the small brown planthopper Laodelphax striatellus, was used to demonstrate that the 3’-terminal extensions suppressed viral replication in vector insects by inhibiting promoter activity due to structural interference with the panhandle structure formed by viral 3’- and 5’-UTRs. The extension sequence in the viral RNA1 segment was targeted by an endogenous insect microRNA, miR-263a, which decreased the inhibitory effect of the extension sequence on viral promoter activity. Surprisingly, the expression of miR-263a was negatively regulated by RSV infection. This elaborate coordination between terminal variation of the viral genome and endogenous insect microRNAs controls RSV replication in planthopper, thus reflecting a distinct strategy of adaptation of phytoviruses to insect vectors.

Small details with great effects on speed running

In sprint events, the start is a special issue, which has led us to conduct a more in-depth study of some biomechanical aspects that, on the one hand, may have permissive effects on performance or, conversely, may have a restrictive influence, depending on the stance adopted by the sprinter when getting into the “set” position for the block start. Ensuring optimal angles at the joints of the body segments enables the runner to quickly react when the starter’s gun is fired, but especially to achieve the most efficient flexion-extension sequence of the lower limb joints (hip-knee-ankle) concurrently with providing the necessary balance that allows focusing attention on the sound of the gun. Carefully watching how the block start positions are approached, it has been found that no two athletes have the same stance at the “set” command and the same dynamics of the first steps. The different approaches to the speed running technique are mainly dependent on each athlete’s morphofunctional characteristics, which will leave their mark on efficiency and specific training sessions. There are many situations in which some say that only a particular position allows them “to feel that they push best the starting block”, while others try to imitate the start positions of certain sprinters they have seen in various television broadcasts just because they have noticed something special in their performance as compared to other athletes, but without understanding the degree of efficiency of those movements.

Coupled Origami Tubes for Stiff Deployable Cantilevers

Thin sheets folded into three dimensional origami structures can be useful in various engineering applications. This work explores the stiffness of deployable origami tubes used as cantilevers. A unique “zipper” configuration is used to couple the tubes, which makes the systems easy to deploy, yet stiff for other deformation modes. The self-restricting geometry of the coupled tubes limits local deformations and makes the systems stiff for out-of-plane loading. The global deployment characteristics are explored using eigenvalue band-gaps, and indicate that tubes with lower sector angles are easy to deploy yet also stiffer for unintended motions. Cantilever analyses show that the geometry of the coupled tubes can significantly affect the stiffness, with some tube combinations having a high orthogonal stiffness throughout deployment, while others only having a high stiffness when fully deployed. Parametric studies are used to show optimal geometries for the coupled tubes that maximize the eigenvalue band-gaps and the stiffness throughout the deployment. The coupled tubes could serve applications such as adjustable robotic arms, and deployable space booms with a reliable extension sequence.

Ongoing human chromosome end extension revealed by analysis of BioNano and nanopore data

ABSTRACTThe majority of human chromosome ends remain incompletely assembled due to their highly repetitive structure. In this study, we use BioNano data to anchor and extend chromosome ends from two European trios as well as two unrelated Asian genomes. BioNano assembled chromosome ends are structurally divergent from the reference genome, including both missing sequence (10%) and extensions(22%). These extensions are heritable and in some cases divergent between Asian and European samples. Six ninths of the extension sequence in NA12878 can be confirmed and filled by nanopore data. We identify two sequence families in these sequences which have undergone substantial duplication in multiple primate lineages. We show that these sequence families have arisen from progenitor interstitial sequence on the ancestral primate chromosome 7. Comparison of chromosome end sequences from 15 species revealed that chromosome end missing sequence matches the corresponding phylogenetic relationship and revealed a rate of chromosome extension per chromosome of 0.0020 bp per year in average.

Efeito da ordem dos exercícios sobre o número de repetições e volume de treino no método de treinamento tri-set

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p187 Although the tri-set system is widely adopted by athletes and experienced weight training practitioners aimed at optimizing the metabolic overload, there are still few works in literature on the effect of exercise order manipulation on this training system. Therefore, this work was aimed at investigating the effect of exercise order manipulation on the number of repeats and training volume using the tri-set system for lower limbs. This is a randomized cross-over design study. The experimental group consisted of 14 healthy men (23.53 ± 5.40 years; 24.51 ± 2.96 kg/m2). Subjects were submitted to two experimental sessions at different exercise order for lower limbs: Sequence A: squat on guided bar, leg press 45° and bilateral leg extension; sequence B: bilateral leg extension, leg press 45° and squat on guided bar. Three sets to volitional fatigue in all exercises were performed, with intensity of 75% 1RM. Superiority for sequence B in the total number of repeats (70.14 ± 13 vs 60.93 ± 7.94 repeats, p = 0.004) and total training volume (9129.64 ± 2830.05 vs 8238.29 ± 2354.20 kg, p = 0.014) was observed. Based on the above, the performance of single-joint exercises before multi-joint exercises in the tri-set system adopted for lower limbs induced higher number of repeats and total training volume.

Verbal extension sequencing: an examination from a computational perspective

Lexical transducers utilise a two-level finite-state network to simultaneously code morphological analysis and morphological generation rewrite rules. Multiple extensions following the verb root can be morphologically analysed as a closed morpheme class using different computational techniques. Analysis of a multiple extension sequence is achieved by trivial analysis, based on any combination of the closed class members, but this produces unnecessary over-generation of lexical items, many of which may not occur in a lexicon. Limiting the extension combinations, in an attempt to represent examples that may actually exist – in terms of both the possible number of extensions in a sequence and the relative ordering of the extensions – leads to a radical reduction in the generation of lexical items while the ability to analyse adequately is maintained. The article highlights details of an investigation based on both trivial analysis and an approach that prevents dramatic overgeneration. The article is based on test data reflecting possible extension sequences and the morphophonemic alternations of these extensions for Northern Sotho, garnered from literature research, lexicographic investigation and the computational morphological analysis of texts.

Quantification of the Detrimental Effect of a Single Primer-Template Mismatch by Real-Time PCR Using the 16S rRNA Gene as an Example

ABSTRACT We investigated the effects of internal primer-template mismatches on the efficiency of PCR amplification using the 16S rRNA gene as the model template DNA. We observed that the presence of a single mismatch in the second half of the primer extension sequence can result in an underestimation of up to 1,000-fold of the gene copy number, depending on the primer and position of the mismatch.

Characterization of the groEL and groES Loci in Bifidobacterium breve UCC 2003: Genetic, Transcriptional, and Phylogenetic Analyses

ABSTRACT The bacterial heat shock response is characterized by the elevated expression of a number of chaperone complexes, including the GroEL and GroES proteins. The groES and groEL genes are highly conserved among eubacteria and are typically arranged as an operon. Genome analysis of Bifidobacterium breve UCC 2003 revealed that the groES and groEL genes are located in different chromosomal regions. The heat inducibility of the groEL and groES genes of B. breve UCC 2003 was verified by slot blot analysis. Northern blot analyses showed that the cspA gene is cotranscribed with the groEL gene, while the groES gene is transcribed as a monocistronic unit. The transcription initiation sites of these two mRNAs were determined by primer extension. Sequence and transcriptional analyses of the region flanking the groEL and groES genes of various bifidobacteria revealed similar groEL-cspA and groES gene units, suggesting a novel genetic organization of these chaperones. Phylogenetic analysis of the available bifidobacterial groES and groEL genes suggested that these genes evolved differently. Discrepancies in the phylogenetic positioning of groES-based trees make this gene an unreliable molecular marker. On the other hand, the bifidobacterial groEL gene sequences can be used as an alternative to current methods for tracing Bifidobacterium species, particularly because they allow a high level of discrimination between closely related species of this genus.