224 research outputs found
A pathogenic long non-coding RNA redesigns the epigenetic landscape of the infected cells by subverting host Histone Deacetylase 6 activity
[EN] Viroids - ancient plant-pathogenic long noncoding RNAs - have developed a singular evolutionary strategy based on reprogramming specific phases of host-metabolism to ensure that their infection cycle can be completed in infected cells. However, the molecular aspects governing this transregulatory phenomenon remain elusive. Here, we use immunoprecipitation assays and bisulfite sequencing of rDNA to shown that, in infected cucumber and Nicotiana benthamina plants, Hop stunt viroid (HSVd) recruits and functionally subverts Histone Deacetylase 6 (HDA6) to promote host-epigenetic alterations that trigger the transcriptional alterations observed during viroid pathogenesis. This notion is supported by the demonstration that, during infection, the HSVd-HDA6 complex occurs invivo and that endogenous HDA6 expression is increased in HSVd-infected cells. Moreover, transient overexpression of recombinant HDA6 reverts the hypomethylation status of rDNA observed in HSVd-infected plants and reduces viroid accumulation. We hypothesize that the host-transcriptional alterations induced as a consequence of viroid-mediated HDA6 recruitment favor spurious recognition of HSVd-RNA as an RNA Pol II template, thereby improving viroid replication. Our results constitute the first description of a physical and functional interaction between a pathogenic RNA and a component of the host RNA silencing mechanism, providing novel evidence of the potential of these pathogenic lncRNAs to physically redesign the host-cell environment and reprogram their regulatory mechanisms.The authors thank Dr M. Fares for the contribution to the statistical analysis of the data and Dr G. Martinez for the critical reading of this manuscript. This work was supported by grants AGL2013-47886-R and BIO2014-61826-EXP (GG) and BIO2014-54862-R (VP) from the Spanish Granting Agency (Direccion General Investigacion Cientifica).Castellano Perez, M.; Pallás Benet, V.; Gomez, GG. (2016). A pathogenic long non-coding RNA redesigns the epigenetic landscape of the infected cells by subverting host Histone Deacetylase 6 activity. New Phytologist. 211(4):1311-1322. doi:10.1111/nph.14001S13111322211
Defying eternal inflation in warm inflation with a negative running
It was pointed out previously~\cite{Kinney:2014jya} that a sufficiently
negative running of the spectral index of curvature perturbations from
(ordinary i.e. cold) inflation is able to prevent eternal inflation from ever
occurring. Here, we reevaluate those original results, but in the context of
warm inflation, in which a substantial radiation component (produced by the
inflaton) exists throughout the inflationary period.
We demonstrate that the same general requirements found in the context of
ordinary (cold) inflation also hold true in warm inflation; indeed an even
tinier amount of negative running is sufficient to prevent eternal inflation.
This is particularly pertinent, as models featuring negative running are more
generic in warm inflation scenarios. Finally, the condition for the existence
of eternal inflation in cold inflation -- that the curvature perturbation
amplitude exceed unity on superhorizon scales -- becomes more restrictive in
the case of warm inflation. The curvature perturbations must be even larger,
i.e. even farther out on the potential, away from the part of the potential
where observables, e.g. in the Cosmic Microwave Background, are produced.Comment: 14 pages, Preprint Numbers: UTWI-40-2023, NORDITA 2023-06
Quantum geometric formulation of Brans-Dicke theory for Bianchi I spacetime
We consider a formulation of the Brans-Dicke theory in Jordan's frame for
Bianchi-I spacetime within the framework of loop quantum gravity. The
robustness of singularity resolutions due to the quantum effects is explicitly
verified. We also present an exploration of the effects of quantum geometry on
the background dynamics. In particular, starting with a detailed constraint
analysis, we present the off-shell Lie algebra of the full theory in the
geometrodynamic phase space. This is followed by casting the theory in terms of
the Yang-Mills phase space variables suitable for invoking loop quantization
and show that the system is highly nonlinear. Finally, we present the
quantum-corrected effective dynamics that resolve the initial singularityComment: 1
Assessment of steady and unsteady friction models in the draining processes of hydraulic installations
The study of draining processes without admitting air has been conducted using only steady friction formulations in the implementation of governing equations. However, this hydraulic event involves transitions from laminar to turbulent flow, and vice versa, because of the changes in water velocity. In this sense, this research improves the current mathematical model considering unsteady friction models. An experimental facility composed by a 4.36 m long methacrylate pipe was configured, and measurements of air pocket pressure oscillations were recorded. The mathematical model was performed using steady and unsteady friction models. Comparisons between measured and computed air pocket pressure patterns indicated that unsteady friction models slightly improve the results compared to steady friction models
Assessment of Steady and Unsteady Friction Models in the Draining Processes of Hydraulic Installations
The study of draining processes without admitting air has been conducted using only steady friction formulations in the implementation of governing equations. However, this hydraulic event involves transitions from laminar to turbulent flow, and vice versa, because of the changes in water velocity. In this sense, this research improves the current mathematical model considering unsteady friction models. An experimental facility composed by a 4.36 m long methacrylate pipe was configured, and measurements of air pocket pressure oscillations were recorded. The mathematical model was performed using steady and unsteady friction models. Comparisons between measured and computed air pocket pressure patterns indicated that unsteady friction models slightly improve the results compared to steady friction models
Concepção e desenvolvimento de sistemas biotecnológicos
In a simple and succinct form the authors intend to present the research and development activities that are being undertaken at the University of Minho in the area of biotechnology applied to the study, design, development and construction of equipment goods, which are being carried out together with important Iberian and European industrial companies.
The projects are as follows:
• Real time monitoring of beer fermentation using optical fiber sensors – MONI®TOR;
• EggReady – Development of a prototype for a continuous industrial production of fried eggs, and
• HealthyCream – Development of innovative dietetical solutions for the deli shop industry.
These projects have been submitted and approved, and are all funded by the Portuguese National Strategic Reference Framework (QREN operational programmes 2007-2013). They are being developed with the following partner companies, all based in Portugal: UNICER Bebidas, S.A. – Innovation and Quality Department (Leça do Balio, Matosinhos); Derovo – Derivados de Ovos, S.A. (Pombal); Decorgel, S.A. (Trofa); Valinox – Indústrias Metalúrgicas, Lda. (Arouca), and the Departments of Biological Engineering (Braga) and Mechanical Engineering (Guimarães), School of Engineering, University of Minho.Pretende-se dar a conhecer, de uma forma simples e sucinta, os projectos de investigação e
desenvolvimento que decorrem, actualmente, na Universidade do Minho, na área da
biotecnologia aplicada ao estudo, concepção, projecto, desenvolvimento e construção de tecido industrial ibérico e europeu.
Os projectos sĂŁo:
· Monitorização em tempo real da fermentação de cerveja na região do UV-Vis e
IVPOC (SWNIR) com recurso a sondas de fibra óptica – MONI®TOR”;
· EggReady - ProtĂłtipo para produção industrial, em contĂnuo, de ovos estrelados para
consumo no canal HORECA, e
· HealthyCream - Desenvolvimento de soluções dietéticas inovadoras para a indústria
de pastelaria.
Estes projectos foram submetidos e aprovados, sendo financiados pelo programa de
incentivos do Quadro de Referência Estratégico Nacional Português, QREN (2007-2013).
Estão a ser realizados em parceria com as empresas UNICER Bebidas, S.A. – Núcleo de
Investigação e Desenvolvimento (Leça do Balio, Matosinhos); Derovo – Derivados de Ovos,
S.A. (Pombal); Decorgel, S.A. (Trofa); Valinox – Indústrias Metalúrgicas, Lda. (Arouca), e os
Departamentos de Engenharia Biológica (Braga) e Engenharia de Mecânica (Guimarães) da
Escola de Engenharia da Universidade do Minho, todas estas instituições sediadas em
Portugal
- …