1,117 research outputs found
Mimicry technology : a versatile tool for small RNA suppression
A decade ago the discovery of the target mimicry regulatory process on the activity of a mature microRNA (miRNA) enabled for the first time the customized attenuation of miRNA activity in plants. That powerful technology was named MIMIC and was based on engineering the IPS1 long noncoding transcript to become complementary to the miRNA under study. In order to avoid IPS1 degradation, the predicted miRNA-mediated cleavage site was interrupted by three additional nucleotides giving rise to the so-called MIMIC decoy. Since then, MIMIC technology has been used in several plant species and in basic and translational research. We here provide a detailed guide to produce custom-designed MIMIC decoys to facilitate the study of sRNA functions in plants
Hyper-reduction for Petrov-Galerkin reduced order models
Projection-based Reduced Order Models minimize the discrete residual of a
"full order model" (FOM) while constraining the unknowns to a reduced dimension
space. For problems with symmetric positive definite (SPD) Jacobians, this is
optimally achieved by projecting the full order residual onto the approximation
basis (Galerkin Projection). This is sub-optimal for non-SPD Jacobians as it
only minimizes the projection of the residual, not the residual itself. An
alternative is to directly minimize the 2-norm of the residual, achievable
using QR factorization or the method of the normal equations (LSPG). The first
approach involves constructing and factorizing a large matrix, while LSPG
avoids this but requires constructing a product element by element,
necessitating a complementary mesh and adding complexity to the hyper-reduction
process. This work proposes an alternative based on Petrov-Galerkin
minimization. We choose a left basis for a least-squares minimization on a
reduced problem, ensuring the discrete full order residual is minimized. This
is applicable to both SPD and non-SPD Jacobians, allowing element-by-element
assembly, avoiding the use of a complementary mesh, and simplifying finite
element implementation. The technique is suitable for hyper-reduction using the
Empirical Cubature Method and is applicable in nonlinear reduction procedures
A methodology for user Interface adaptation of multi-device broadcast-broadband services
New audiovisual experiences involve consuming several contents displayed through multiple
internet-connected devices. The TV is still the central hub of the living room, but it is often used
simultaneously with other screens. Consequently, the user has the chance to consume all different contents
at once across multiple devices. However, no existing adaptation models are available to dynamically adapt
such a multitude of contents in multi-device contexts. To address this gap, this paper proposes a novel
multi-device adaptation methodology to build adaptive User Interfaces for multi-screen hybrid broadcastbroadband TV experiences. The methodology is extensible to any kind of content, device and user, and
is applicable to different contexts considering technological evolution and other fields of application. The
proposed methodology is the outcome of extensive research that arose from a previous multi-device media
service deployment with broadcasters
The proinflammatory cytokine interleukin 18 regulates feeding by acting on the bed nucleus of the stria terminalis
The proinflammatory cytokine IL-18 has central anorexigenic effects and was proposed to contribute to loss of appetite observed during sickness. Here we tested in the mouse the hypothesis that IL-18 can decrease food intake by acting on neurons of the bed nucleus of the stria terminalis (BST), a component of extended amygdala recently shown to influence feeding via its projections to the lateral hypothalamus (LH). We found that both subunits of the heterodimeric IL-18 receptor are highly expressed in the BST and that local injection of recombinant IL-18 (50 ng/ml) significantly reduced c-fos activation and food intake for at least 6 h. Electrophysiological experiments performed in BST brain slices demonstrated that IL-18 strongly reduces the excitatory input on BST neurons through a presynaptic mechanism. The effects of IL-18 are cell-specific and were observed in Type III but not in Type I/II neurons. Interestingly, IL-18-sensitve Type III neurons were recorded in the juxtacapsular BST, a region that contains BST-LH projecting neurons. Reducing the excitatory input on Type III GABAergic neurons, IL-18 can increase the firing of glutamatergic LH neurons through a disinhibitory mechanism. Imbalance between excitatory and inhibitory activity in the LH can induce changes in food intake. Effects of IL-18 were mediated by the IL-18R because they were absent in neurons from animals null for IL-18Rα (Il18ra-/-), which lack functional IL-18 receptors. In conclusion, our data show that IL-18 may inhibit feeding by inhibiting the activity of BST Type III GABAergic neurons
Vegetation pattern modulates ground arthropod diversity in semi-arid Mediterranean steppes
The ecological functioning of dryland ecosystems is closely related to the spatial pattern of the vegetation, which is typically structured in patches. Ground arthropods mediate key soil functions and ecological processes, yet little is known about the influence of dryland vegetation pattern on their abundance and diversity. Here, we investigate how patch size and cover, and distance between patches relate to the abundance and diversity of meso-and microarthropods in semi-arid steppes. We found that species richness and abundance of ground arthropods exponentially increase with vegetation cover, patch size, and patch closeness. The communities under vegetation patches mainly respond to patch size, while the communities in the bare-soil interpatches are mostly controlled by the average distance between patches, independently of the concurrent changes in vegetation cover. Large patches seem to play a critical role as reserve and source of ground arthropod diversity. Our results suggest that decreasing vegetation cover and/or changes in vegetation pattern towards small and over-dispersed vegetation patches can fast lead to a significant loss of ground arthropods diversity in drylands
Mites of the genus Antennoseius Berlese (Acari: Mesostigmata: Ascidae) from Iran
Abstract: Three species of mites in the subgenus Antennoseius (Antennoseius) Berlese, 1916 associated with ground beetles (Coleoptera, Carabidae) are reported for the first time from Iran: A. (A.) longisetus Eidelberg, A. (A.) sabulicola Bregetova and A. (A.) sharonovi Eidelberg. These species and A. (A.) masoviae Sellnick, are diagnosed in detail. Idiosomal poroidotaxy and adenotaxy for the subgenus are illustrated. A. (A.) vysotskajae Sklyar is considered as junior synonym of A. (A.) sharonovi. A key to Iranian species of the genus is presented
Phytochrome interacting factors 4 and 5 control seedling growth in changing light conditions by directly controlling auxin signaling.
Plant growth is strongly influenced by the presence of neighbors that compete for light resources. In response to vegetational shading shade-intolerant plants such as Arabidopsis display a suite of developmental responses known as the shade-avoidance syndrome (SAS). The phytochrome B (phyB) photoreceptor is the major light sensor to mediate this adaptive response. Control of the SAS occurs in part with phyB, which controls protein abundance of phytochrome-interacting factors 4 and 5 (PIF4 and PIF5) directly. The shade-avoidance response also requires rapid biosynthesis of auxin and its transport to promote elongation growth. The identification of genome-wide PIF5-binding sites during shade avoidance revealed that this bHLH transcription factor regulates the expression of a subset of previously identified SAS genes. Moreover our study suggests that PIF4 and PIF5 regulate elongation growth by controlling directly the expression of genes that code for auxin biosynthesis and auxin signaling components
Differential root transcriptomics in a polyploid non-model crop: the importance of respiration during osmotic stress
To explore the transcriptomic global response to osmotic stress in roots, 18 mRNA-seq libraries were generated from three triploid banana genotypes grown under mild osmotic stress (5% PEG) and control conditions. Illumina sequencing produced 568 million high quality reads, of which 70–84% were mapped to the banana diploid reference genome. Using different uni- and multivariate statistics, 92 genes were commonly identified as differentially expressed in the three genotypes. Using our in house workflow to analyze GO enriched and underlying biochemical pathways, we present the general processes affected by mild osmotic stress in the root and focus subsequently on the most significantly overrepresented classes associated with: respiration, glycolysis and fermentation. We hypothesize that in fast growing and oxygen demanding tissues, mild osmotic stress leads to a lower energy level, which induces a metabolic shift towards (i) a higher oxidative respiration, (ii) alternative respiration and (iii) fermentation. To confirm the mRNA-seq results, a subset of twenty up-regulated transcripts were further analysed by RT-qPCR in an independent experiment at three different time points. The identification and annotation of this set of genes provides a valuable resource to understand the importance of energy sensing during mild osmotic stress
The proinflammatory cytokine interleukin 18 regulates feeding by acting on the bed nucleus of the stria terminalis
The proinflammatory cytokine IL-18 has central anorexigenic effects and was proposed to contribute to loss of appetite observed during sickness. Here we tested in the mouse the hypothesis that IL-18 can decrease food intake by acting on neurons of the bed nucleus of the stria terminalis (BST), a component of extended amygdala recently shown to influence feeding via its projections to the lateral hypothalamus (LH). We found that both subunits of the heterodimeric IL-18 receptor are highly expressed in the BST and that local injection of recombinant IL-18 (50 ng/ml) significantly reduced c-fos activation and food intake for at least 6 h. Electrophysiological experiments performed in BST brain slices demonstrated that IL-18 strongly reduces the excitatory input on BST neurons through a presynaptic mechanism. The effects of IL-18 are cell-specific and were observed in Type III but not in Type I/II neurons. Interestingly, IL-18-sensitve Type III neurons were recorded in the juxtacapsular BST, a region that contains BST-LH projecting neurons. Reducing the excitatory input on Type III GABAergic neurons, IL-18 can increase the firing of glutamatergic LH neurons through a disinhibitory mechanism. Imbalance between excitatory and inhibitory activity in the LH can induce changes in food intake. Effects of IL-18 were mediated by the IL-18R because they were absent in neurons from animals null for IL-18R\u3b1 (Il18ra-/-), which lack functional IL-18 receptors. In conclusion, our data show that IL-18 may inhibit feeding by inhibiting the activity of BST Type III GABAergic neurons
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