Use of bacterial Rho helicase to gain new insights into the targeting mechanism of nuclear RNAs by the exosome-associated exoribonuclease Rrp6 and its cofactors in yeast

In eukaryotic cells, aberrant mRNPs with processing and packaging defects are targeted co-transcriptionally by a surveillance system that triggers their nuclear retention and ultimately the degradation of their mRNA component by the 3’-5’ activity of the exosome-associated exoribonuclease Rrp6 along with its associated factors Rrp47 and Mpp6. This mRNP quality control process is stimulated by the NNS complex (Nrd1-Nab3-Sen1), which otherwise mediates termination, processing and decay of ncRNAs and the process involves additionally the exosome co-activator TRAMP complex (Trf4-Air2-Mtr4). Here, we describe a genome-wide approach to visualize the dynamic recruitment of these quality control components over the yeast chromosomes upon global perturbation of mRNP biogenesis by the RNA-dependent helicase/translocase activity of the bacterial Rho factor. The method provides valuable information on how the surveillance system coordinates with the transcription machinery in order to detect faulty events during perturbation of mRNP biogenesis. In addition, our overview shows that the assembly of the quality control components for the affected mRNA genes takes place at the expense of their commitment to be recruited to ncRNAs genomic features, which in turn leads to termination and processing defects of ncRNAs.</p

Methodological approach for creating an IoT manufacturing application

With the heterogeneity and diversity of electronic systems and their memory capacity, the Internet of Things technologies face several challenges, such as the difficulty in choosing a growing catalogue of IoT technologies and the lack of interoperability of these technologies. This leads to the creation of particular IoT architectures and to the selection of IoT technologies by trying and error approaches. We propose a methodological approach for creating an IoT application guided by the users’ needs and by the contextual environment. It enables the user to select the right hardware guided by the market supply and to check the performances of the IoT solutions. We implement and test our proposition in a picking system of a manufacturing factory. This practical implementation provides feedback regarding our methodological approach for creating an IoT application, which in turn enables us to improve and remodel the approach.info:eu-repo/semantics/acceptedVersio

On a Low-Frequency and Contrast Stabilized Full-Wave Volume Integral Equation Solver for Lossy Media

In this article, we present a new regularized electric flux volume integral equation (D-VIE) for modeling high-contrast conductive dielectric objects in a broad frequency range. This new formulation is particularly suitable for modeling biological tissues at low frequencies, as it is required by brain epileptogenic area imaging, but also at higher ones, as it is required by several applications, including, but not limited to, deep brain stimulation (DBS). When modeling inhomogeneous objects with high complex permittivities at low frequencies, the traditional D-VIE is ill-conditioned and suffers from numerical instabilities that result in slower convergence and less accurate solutions. In this work, we address these shortcomings by leveraging a new set of volume quasi-Helmholtz projectors. Their scaling by the material permittivity matrix allows for the rebalancing of the equation when applied to inhomogeneous scatterers and, thereby, makes the proposed method accurate and stable even for high complex permittivity objects until arbitrarily low frequencies. Numerical results, canonical and realistic, corroborate the theory and confirm the stability and the accuracy of this new method both in the quasi-static regime and at higher frequencies

Les Algues Indicatrices De L'eutrophisation Et De La Contamination De La Lagune De Korba (Cap Bon Tunisie)

The concentrations of heavy metals (Fe, Zn, Pb and Mn) were determined in two green algae (Enteromorpha intestinalis and Chaetomorpha Linium) collected from April 2012 to February 2013 in nine stations characterized by the abundance of these algae throughout the year. Determination of Pb, Mn and Zn was carried out by graphite furnace atomic absorption spectrometer while Fe by flame atomic absorption spectrometer (using the Thermo Scientific ICE 3300 AA Spectrometer). An evaluation of the degree of eutrophication is made through the physicochemical study of 31 samples in the surface water. The results underline that Korba is an eutrophic lagoon. The heavy metal concentrations in the water samples decreased in the sequence of Fe &gt;Zn &gt; Mn &gt; Pb, while in Chaetomorpha Linium, Enteromorpha intestinalis and sediment exhibited the same pattern across the sites: Fe &gt;Mn&gt; Zn &gt;Pb. The results show that metal accumulation capacity in both macro-algae varies according to the season and depends on the species. By comparison with other studies in the world, the levels found in the algae of Korba lagoon are relatively high except Mn. Chaetomorpha Linium could be used as an excellent indicator for heavy metals accumulation in Korba lagoon

Productivity, heritability and stability analysis of a Moroccan sugar beet germplasm

Received: January 19th, 2021 ; Accepted: March 27th, 2021 ; Published: April 6th 2021 ; Correspondence: [email protected] testing is the second part of maternal recurrent selection scheme adopted by INRA-Morocco for the national sugar beet breeding programme. The objective of this study is sugar beet germplasm productivity, heritability and stability analysis. The studied material concern 18 half-sib families (HSF) preselected initially for their seed production potential. Trials were conducted using randomised complete blocks designs during, 2013/14, 2014/15, 2015/16, 2017/18 campaigns in two experimental fields of INRA-Morocco; Sidi Allal Tazi (34° 30' N, 6° 19' W) and Larache (35° 11’ N, 6° 09’ W). Evaluated parameters concern the vigour, root weight (RW), leaf biomass yield (LBY), and sugar content (Sc). Data analysis by comparative procedures explores different accordance degrees of HSF versus controls. Good vegetative growth was observed, 85.6% closer to the maximal indicated scale level. The RW was significantly influenced by the genotype and reached a maximum of 1.06 kg versus 1.08 kg average recorded by controls. Sugar content recorded mean was 20.97% in HSF versus 21.39% in the controls. Most of HSF revealed mean values close to Z-type variety. Estimated heritability was 0.5 for RW, 0.2 for the LBY, and 0.02 for Sc. Sugar content was influenced by the environment and explained by the AMMI model (73.6%) versus 53.9% and 44.4% for root weight and leaf biomass yield respectively. The AMMI stability values showed F11, F12, F16, and F17 families as the most performing and stable HSF. Results demonstrate the relevance of the maternal recurrent selection scheme of the on-going national breeding programme

Coda wave attenuation tomography in Northern Morocco

In this study we focused on seismic attenuation (1/ Q) tomography in Northern Morocco. For this purpose, two different models are employed: The Single Backscattering model hypothesis of Aki and Chouet (1975) to calculate values of Coda Q (Q) and the Back-projection technique of Xie and Mitchell (1990) to estimate lateral variation in Q via a tomographic inversion. For this investigation, the Coda Q method is applied to a number of 94 local earthquakes with a magnitude between Ml=0.7 and Ml=4. The digital seismograms of these earthquakes were recorded during the year 2008 by both local temporary and permanent broadband seismic station network deployed in Northern of Morocco. The Q quality factor values have been computed at central frequencies 0.75, 1.5, 3, 6 and 12 Hz. The lapse time windows are restricted to 30s in order to sample the earth's crust only. The Q results indicate that strong frequency dependence follow a power law for the entire area. The preliminary results of seismic Coda Q attenuation tomography shows a dependence at each frequency band, between seismic attenuation and the geology structure units in the study area, especially in the region of Al Hoceima and the eastern part of the Rif which are characterized by high attenuation values due to active faults area, while low attenuation values are seen in the west and the south of the Rif in high frequencies.Peer Reviewe

Toxicity and neurophysiological impacts of three plant-derived essential oils against the vineyard mealybug Planococcus ficus

Many natural products are able to control pests and can be used as alternatives for chemical treatments. Plant essential oils (EOs) have been found to exhibit some biological activity against many insects including mealybugs. This study aimed at studying the insecticidal activity and behavioral and neurophysiological impacts of three plant essential oils against the vine mealybug Planococcus ficus. The topical and fumigant toxicity of Cymbopogon citratus, Mentha piperita, and Pelargonium graveolens essential oils was evaluated against P. ficus adults. The chemical composition analysis of EOs by gas chromatographic-mass spectrometry (GC-MS) revealed citronellal (31.69 %), menthol (73.78 %), and geraniol (39.6%), as major components, respectively. Bioassays of EOs against vine mealybug adults through fumigation toxicity method revealed lethal concentrations LC50 values of 17.01, 26.27 and 24.52 µL·L-1 air for C. citratus, M. piperita, and P. graveolens, respectively. In both topical and fumigant bioassays, essential oil from C. citratus was the most active altering the behavioral response of treated mealybugs which becomes hyperactive and disoriented. EOs induced general stress in P. ficus adults, as evidenced by oxidative stress biomarker analyses. Biochemical analyses showed that the EOs exposure reduced the activity of acetylcholinesterase and significantly induced the glutathione S-transferases and Malondialdehydes accumulation in the vine mealybug tissues. Mortality caused by lemongrass EO positively correlated with the significant decrease in the AChE activity indicating lethal neurological effects. These toxicity bioassays and neurological impact findings provide new informations for formulating effective essential oil based-insecticides to control P. ficus in the framework of integrated pest management programs

A Leptin-regulated Circuit Controls Glucose Mobilization During Noxious Stimuli

Adipocytes secrete the hormone leptin to signal the sufficiency of energy stores. Reductions in circulating leptin concentrations reflect a negative energy balance, which augments sympathetic nervous system (SNS) activation in response to metabolically demanding emergencies. This process ensures adequate glucose mobilization despite low energy stores. We report that leptin receptor–expressing neurons (LepRb neurons) in the periaqueductal gray (PAG), the largest population of LepRb neurons in the brain stem, mediate this process. Application of noxious stimuli, which often signal the need to mobilize glucose to support an appropriate response, activated PAG LepRb neurons, which project to and activate parabrachial nucleus (PBN) neurons that control SNS activation and glucose mobilization. Furthermore, activating PAG LepRb neurons increased SNS activity and blood glucose concentrations, while ablating LepRb in PAG neurons augmented glucose mobilization in response to noxious stimuli. Thus, decreased leptin action on PAG LepRb neurons augments the autonomic response to noxious stimuli, ensuring sufficient glucose mobilization during periods of acute demand in the face of diminished energy stores