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War, natural disasters, and other emergencies regularly disrupt children's education in developing countries. The digital divide has long since affected low-resource and rural schools' responses to crises that necessitate distance learning, often excluding children in remote and rural parts of countries from internet-dependent online learning programmes. In no place is this truer than in Haiti where, prior to August 2020, political unrest combined with the COVID-19 pandemic caused learners to miss 60% of their scheduled days in the 2019-2020 school year with only 45% of Haitian households having access to a power source, let alone internet or a smart device, that would enable them to participate in online learning. This study presents findings from exploratory research on the readiness of the Haitian education system to withstand crises and the impact of COVID-19 on the system and its learners. Through analyses of secondary data and semi-structured interviews with a variety of education stakeholders, the research reveals gaps in the system's readiness; identifies key challenges prompted by school closures in Haiti and shares a handful of innovative responses developed to respond to these challenges. Findings indicate that the COVID-19 health crisis has not created the need for educational reform in Haiti, but rather, by exacerbating pre-existing gaps and frailties within the system, the pandemic has heightened the urgency with which educational reform must be pursued. Salient gaps include a significant digital divide, financial instability and inattention to learning adjacent needs such as nutrition and psychosocial health for parents and children alike. While this initial research has exposed a series of significant gaps and inequalities in the Haitian education system, moving forward, more comprehensive research is needed to determine how such inequalities can be most effectively addressed. Although the Haitian government has a key role to play in addressing these inequalities, findings from this study reveal that governmental responses to COVID-19 school closures and broader digital learning inequalities, were ineffective in their reach and did not reflect the majority of Haitian learners and their families' realities. Findings also identify numerous innovations and assets on the part of non-governmental actors striving to address these gaps. However, these mechanisms were limited in scope and lacked the coordination among one another and the government that would be required to have scalable or measurable impact. Therefore, more research is needed to determine what the most successful mechanisms for addressing inequalities in the Haitian education system are and how they can be most effectively leveraged and scaled to create a more resilient education system moving forward.

War, natural disasters, and other emergencies regularly disrupt children's education in developing countries. The digital divide has long since affected low-resource and rural schools' responses to crises that necessitate distance learning, often excluding children in remote and rural parts of countries from internet-dependent online learning programmes. In no place is this truer than in Haiti where, prior to August 2020, political unrest combined with the COVID-19 pandemic caused learners to miss 60% of their scheduled days in the 2019--2020 school year with only 45% of Haitian households having access to a power source, let alone internet or a smart device, that would enable them to participate in online learning. This study presents findings from exploratory research on the readiness of the Haitian education system to withstand crises and the impact of COVID-19 on the system and its learners. Through analyses of secondary data and semi-structured interviews with a variety of education stakeholders, the research reveals gaps in the system's readiness; identifies key challenges prompted by school closures in Haiti and shares a handful of innovative responses developed to respond to these challenges. Findings indicate that the COVID-19 health crisis has not created the need for educational reform in Haiti, but rather, by exacerbating pre-existing gaps and frailties within the system, the pandemic has heightened the urgency with which educational reform must be pursued. Salient gaps include a significant digital divide, financial instability and inattention to learning adjacent needs such as nutrition and psychosocial health for parents and children alike. While this initial research has exposed a series of significant gaps and inequalities in the Haitian education system, moving forward, more comprehensive research is needed to determine how such inequalities can be most effectively addressed. Although the Haitian government has a key role to play in addressing these inequalities, findings from this study reveal that governmental responses to COVID-19 school closures and broader digital learning inequalities, were ineffective in their reach and did not reflect the majority of Haitian learners and their families' realities. Findings also identify numerous innovations and assets on the part of non-governmental actors striving to address these gaps. However, these mechanisms were limited in scope and lacked the coordination among one another and the government that would be required to have scalable or measurable impact. Therefore, more research is needed to determine what the most successful mechanisms for addressing inequalities in the Haitian education system are and how they can be most effectively leveraged and scaled to create a more resilient education system moving forward. [ABSTRACT FROM AUTHOR]

High-pressure turbine blades are subject to large thermomechanical loads that may threaten their mechanical integrity. The prediction of the heat transfer on the blade surface, crucial to ensure its durability, thus requires an accurate description of the flow physics around the blade to be reliable. In an effort to better qualify the use of computational fluid dynamics in this design context as well as the need for an improved understanding of the flow physics, this paper investigates a transonic highly loaded linear turbine blade cascade that has been found difficult to predict in the literature using large-eddy simulations. Indeed, the configuration results in shocks and acoustic waves on the suction side of the blade, features that are commonly encountered in high-pressure turbines. Turbulent spots are observed on the suction-side boundary layer with an inlet turbulence intensity of 6%. The turbulent spots are shown to have a complex and highly unsteady effect on the shock/boundary-layer interaction, disrupting flow detachment and creating laminar spots downstream of the shock. To address these transient flow phenomena, conditional averages based on the intermittency level are introduced to show that accurate heat transfer predictions require an accurate prediction of the rate of turbulent-spot production. The analysis then focuses on the effect of intermittency on the turbulent kinetic energy exchanges in the near-wall region as the turbulent kinetic energy balance must be addressed in Reynolds-averaged Navier–Stokes models. [ABSTRACT FROM AUTHOR]

This paper studies the large-eddy simulation of anisothermal low Mach number turbulent channel flows. We consider the large-eddy simulations of the low Mach number equations in two formulations, the velocity formulation and the Favre formulation. In both formulations, we investigate the subgrid-scale modeling of the two most significant subgrid terms of the filtered low Mach number equations: the momentum convection subgrid term and the density-velocity correlation subgrid term. To this end, the predictions of large-eddy simulations implementing the models are compared to filtered direct numerical simulations. We address several types of subgrid-scale models: functional eddy-viscosity or eddy-diffusivity models, structural models, tensorial models, and dynamic versions of these models. For the momentum convection subgrid term, we recommend the use of the scale-similarity model and the constant-parameter or dynamic tensorial anisotropic minimum-dissipation (AMD) model. For the density-velocity correlation subgrid term, several models are able to improve temperature-related statistics, for instance, the AMD model and the scale-similarity model. More accurate results are obtained with the Favre formulation than with the velocity formulation. [ABSTRACT FROM AUTHOR]

This paper studies the large-eddy simulation (LES) of isothermal turbulent channel flows. We investigate zero-equation algebraic models without wall function or wall model: functional models, structural models, and mixed models. In addition to models from the literature, new models are proposed and their relevance is examined. Dynamic versions of each type of model are also analyzed. The performance of the subgrid-scale models is assessed using the same finite difference numerical method and physical configuration. The friction Reynolds number of the simulations is 180. Three different mesh resolutions are used. The predictions of large-eddy simulations are compared to those of a direct numerical simulation filtered at the resolution of the LES meshes. The results are more accurate than those of a simulation without model. The predictions of functional eddy-viscosity models can be improved using constant-parameter or dynamic tensorial methods. [ABSTRACT FROM AUTHOR]

Spatial and spectral energy exchanges associated with the turbulence kinetic energy per unit mass, or the half-trace of the velocity covariance tensor, are studied in an anisothermal low Mach number turbulent channel flow. The temperatures of the two channel walls are 293 K and 586 K. This generates a strong temperature gradient in the wall-normal direction. The effect of the temperature gradient on the energy exchanges is investigated using two direct numerical simulations of the channel, at the mean friction Reynolds numbers 180 and 395. The temperature gradient creates an asymmetry between the energy exchanges at the hot and cold sides due to the variations of the local fluid properties and low Reynolds number effects. The low Reynolds number effects are smaller at higher Reynolds numbers, reducing the asymmetry between the hot and cold sides. We also decomposed the energy exchanges in order to study separately the mean-property terms, as found in the constant-property isothermal case, and the thermal terms, specific to flows with variable fluid properties. The significant thermal terms have a similar effect on the flow. Besides, low Reynolds number effects have a negligible impact on thermal terms and only affect mean-property terms. [ABSTRACT FROM AUTHOR]

The discretized source magnetic vector potential \mathrm Aj , projected from source field \mathrm Hs with \text H(\text curl, \Omega ) semi-norm, is studied for non-meshed coils with magnetic vector potential A and electric scalar potential V formulation. As a novelty, source potential \Omega _{\mathrm{ red}} instead of the complete domain \Omega $ . For domains with fixed and moving parts, potential \mathrm Aj can be computed on each part, for each of the related current sources, with no need to ensure its continuity between these parts. [ABSTRACT FROM AUTHOR]

ABSTRACT The present study aims at investigating the influence of Ar sputtering gas pressure on the properties of molybdenum back contact (deposited on soda-lime glass) and consequences on co-evaporated Cu(In,Ga)Se2 (CIGSe) absorber layer and related solar cell. Films 300 nm thick have been grown with argon pressure between 0·75 and 11·25 mTorr; these films have been characterized by several techniques showing that the increase of the sputtering pressure yields wider amorphous areas, containing oxygen and sodium, between the molybdenum grains, thus higher sheet resistance. The volume ratio of these amorphous areas is referenced to as 'porosity'. The structural and morphological properties of co-evaporated CIGSe have not been reliably observed influenced by the molybdenum porosity; the only noticeable change is the sodium content of the absorber, which increases with the porosity of the back contact. The impact of the amount of sodium on the device performance has been observed to be very important. On the one hand, as already reported, sodium is beneficial for the open-circuit voltage. On the other hand, a too high amount of sodium is detrimental for the fill factor (hindered shunt resistance), thus the cell efficiency; this latter observation is interpreted as a change in the grain boundary electrical properties. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Kriging was first introduced in the field of geostatistics. Nowadays, it is widely used to model computer experiments. Since the results of deterministic computer experiments have no experimental variability, Kriging is appropriate in that it interpolates observations at data points. Moreover, Kriging quantifies prediction uncertainty, which plays a major role in many applications. Among practitioners we can distinguish those who use Universal Kriging where the parameters of the model are estimated and those who use Bayesian Kriging where model parameters are random variables. The aim of this article is to show that the prediction uncertainty has a correct interpretation only in the case of Bayesian Kriging. Different cases of prior distributions have been studied and it is shown that in one specific case, Bayesian Kriging supplies an interpretation as a conditional variance for the prediction variance provided by Universal Kriging. Finally, a simple petroleum engineering case study presents the importance of prior information in the Bayesian approach. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper is concerned with an asymptotic approach for a micropolar flow through a thin curvilinear channel. A priori estimates (which we obtain together with the existence and the uniqueness of the solution) are used to establish the error between the exact solution and the asymptotic one and to justify the asymptotic analysis. We obtain the expression of an expansion of order K and we study the general problems for the boundary layer functions. Under some additional assumptions on the data we obtain satisfactory error estimates. [ABSTRACT FROM AUTHOR]

The asymptotic analysis of a micropolar flow through a wavy tube structure is studied. We suppose that the domain depends on a small parameter that represents the width and the order of the periodicty of the domain. The Stokes and Navier-Stokes problems in the union of tubes (with a constant section) were earlier studied. The generalization of the Method of Asymptotic Partial Decomposition of Domain in a structure with some periodic tubes is described and justified in order to propose a simplified modeling for the bloodstream. [ABSTRACT FROM AUTHOR]

The steady motion of a micropolar fluid through a wavy tube with the dimensions depending on a small parameter is studied. An asymptotic expansion is proposed and error estimates are proved by using a boundary layer method. We apply the method of partial asymptotic decomposition of domain and we prove that the solution of the partially decomposed problem represents a good approximation for the solution of the considered problem. [ABSTRACT FROM AUTHOR]

Exposure to ionizing radiation can induce genetic aberrations via unrepaired DNA strand breaks. To investigate quantitatively the dose-effect relationship at the molecular level, we irradiated dry pBR322 plasmid DNA with 3 MeV protons and assessed fragmentation yields at different radiation doses using long-read sequencing from Oxford Nanopore Technologies. This technology applied to a reference DNA model revealed dose-dependent fragmentation, as evidenced by read length distributions, showing no discernible radiation sensitivity in specific genetic sequences. In addition, we propose a method for directly measuring the single-strand break (SSB) yield. Furthermore, through a comparative study with a collection of previous works on dry DNA irradiation, we show that the irradiation protocol leads to biases in the definition of ionizing sources. We support this scenario by discussing the size distributions of nanopore sequencing reads in the light of Geant4 and Geant4-DNA simulation toolkit predictions. We show that integrating long-read sequencing technologies with advanced Monte Carlo simulations paves a promising path toward advancing our comprehension and prediction of radiation-induced DNA fragmentation., (© 2024. The Author(s).)

This study aimed to explore the potential of metal oxides such as Titanate Scrolled Nanosheets (TNs) in improving the radiosensitivity of sarcoma cell lines. Enhancing the response of cancer cells to radiation therapy is crucial, and one promising approach involves utilizing metal oxide nanoparticles. We focused on the impact of exposing two human sarcoma cell lines to both TNs and ionizing radiation (IR). Our research was prompted by previous in vitro toxicity assessments, revealing a correlation between TNs' toxicity and alterations in intracellular calcium homeostasis. A hydrothermal process using titanium dioxide powder in an alkaline solution produced the TNs. Our study quantified the intracellular content of TNs and analyzed their impact on radiation-induced responses. This assessment encompassed PIXE analysis, cell proliferation, and transcriptomic analysis. We observed that sarcoma cells internalized TNs, causing alterations in intracellular calcium homeostasis. We also found that irradiation influence intracellular calcium levels. Transcriptomic analysis revealed marked disparities in the gene expression patterns between the two sarcoma cell lines, suggesting a potential cell-line-dependent nano-sensitization to IR. These results significantly advance our comprehension of the interplay between TNs, IR, and cancer cells, promising potential enhancement of radiation therapy efficiency., (© 2024. The Author(s).)

Cellular senescence is a pathophysiological process with multifaceted effects. It is involved in wound healing, aging and age-related diseases as well as cancer. On the one hand, senescence is considered as barrier against tumorigenesis by inducing an irreversible/prolonged cell cycle arrest. On the other hand, it may promote tumorigenesis when senescent cells accumulate genomic instability and bypass this cell cycle arrest. Interestingly, the bystander effects mediate the propagation of the genetic instability from senescent cells to their environment through the SASP (Senescence Associated Secretory Phenotype) including proinflammatory cytokines, proteases, growth factors and Reactive Oxygen Species 'ROS.' From several markers explored to detect senescent cells (β-galactosidase, p16, p21, p53, heterochromatin foci, DNA damage,…), ROS arouse particular interest because of their involvement at the chronic supraphysiological level, in the induction and maintain of DNA damage, inflammation, cell cycle disruption and epigenetic instability. In this context, the choice of methods to detect ROS in senescent cells is of particular interest and must take into account relevant parameters as well as the specificity for each species of ROS and the subcellular localization of ROS production. In this chapter, we introduce senescence and ROS, we briefly discuss the advantages and the shortcomings of methods routinely used to detect ROS. In addition, we describe the protocol to detect ROS at mitochondrial level (using the MitoSOX staining) in the BCPAP cell line (from human papillary thyroid carcinomas) expressing BRAF V600E oncogene known to trigger senescence., (Copyright © 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

We describe a methodology to manipulate Caenorhabditis elegans ( C. elegans ) and irradiate the stem progenitor gonad region using three MeV protons at a specific developmental stage (L1). The consequences of the targeted irradiation were first investigated by considering the organogenesis of the vulva and gonad, two well-defined and characterized developmental systems in C. elegans . In addition, we adapted high-throughput analysis protocols, using cell-sorting assays (COPAS) and whole transcriptome analysis, to the limited number of worms (>300) imposed by the selective irradiation approach. Here, the presented status report validated protocols to (i) deliver a controlled dose in specific regions of the worms; (ii) immobilize synchronized worm populations (>300); (iii) specifically target dedicated cells; (iv) study the radiation-induced developmental alterations and gene induction involved in cellular stress (heat shock protein) and cuticle injury responses that were found.

Cytokinesis partitions cellular content between daughter cells. It relies on the formation of an acto-myosin contractile ring, whose constriction induces the ingression of the cleavage furrow between the segregated chromatids. Rho1 GTPase and its RhoGEF (Pbl) are essential for this process. However, how Rho1 is regulated to sustain furrow ingression while maintaining correct furrow position remains poorly defined. Here, we show that during asymmetric division of Drosophila neuroblasts, Rho1 is controlled by two Pbl isoforms with distinct localisation. Spindle midzone- and furrow-enriched Pbl-A focuses Rho1 at the furrow to sustain efficient ingression, while Pbl-B pan-plasma membrane localization promotes the broadening of Rho1 activity and the subsequent enrichment of myosin on the entire cortex. This enlarged zone of Rho1 activity is critical to adjust furrow position, thereby preserving correct daughter cell size asymmetry. Our work highlights how the use of isoforms with distinct localisation makes an essential process more robust., (© 2023. The Author(s).)

In nematodes and kinetoplastids, mRNA processing involves a trans-splicing step through which a short sequence from a snRNP replaces the original 5' end of the primary transcript. It has long been held that 70% of C. elegans mRNAs are submitted to trans-splicing. Our recent work suggested that the mechanism is more pervasive but not fully captured by mainstream transcriptome sequencing methods. Here we use Oxford Nanopore's long-read amplification-free sequencing technology to perform a comprehensive analysis of trans-splicing in worms. We demonstrate that spliced leader (SL) sequences at the 5' end of the mRNAs affect library preparation and generate sequencing artefacts due to their self-complementarity. Consistent with our previous observations, we find evidence of trans-splicing for most genes. However, a subset of genes appears to be only marginally trans-spliced. These mRNAs all share the capacity to generate a 5' terminal hairpin structure mimicking the SL structure and offering a mechanistic explanation for their non conformity. Altogether, our data provide a comprehensive quantitative analysis of SL usage in C. elegans., (© 2023. The Author(s).)

Trypanosomatid parasites are responsible for various human diseases, such as sleeping sickness, animal trypanosomiasis, or cutaneous and visceral leishmaniases. The few available drugs to fight related parasitic infections are often toxic and present poor efficiency and specificity, and thus, finding new molecular targets is imperative. Aminoacyl-tRNA synthetases (aaRSs) are essential components of the translational machinery as they catalyze the specific attachment of an amino acid onto cognate tRNA(s). In trypanosomatids, one gene encodes both cytosolic- and mitochondrial-targeted aaRSs, with only three exceptions. We identify here a unique specific feature of aaRSs from trypanosomatids, which is that most of them harbor distinct insertion and/or extension sequences. Among the 26 identified aaRSs in the trypanosome Leishmania tarentolae, 14 contain an additional domain or a terminal extension, confirmed in mature mRNAs by direct cDNA nanopore sequencing. Moreover, these RNA-Seq data led us to address the question of aaRS dual localization and to determine splice-site locations and the 5'-UTR lengths for each mature aaRS-encoding mRNA. Altogether, our results provided evidence for at least one specific mechanism responsible for mitochondrial addressing of some L. tarentolae aaRSs. We propose that these newly identified features of trypanosomatid aaRSs could be developed as relevant drug targets to combat the diseases caused by these parasites., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Artificial compressibility methods aim to reduce the stiffness of the compressible Navier-Stokes equations by artificially decreasing the velocity of acoustic waves in the fluid. This approach has originally been developed as an alternative to the incompressible Navier-Stokes equations as this avoids the resolution of a Poisson equation. This paper extends the method to anisothermal low Mach number flows, allowing the simulations of subsonic flows submitted to large temperature variations, including dilatational effects. The procedure is shown to be stable and accurate using a finite-difference method in a staggered grid system for the simulation of strongly anisothermal turbulent channel flow. The highly scalable nature of the approach is well suited to complex high-fidelity simulations and GPU processing.

In the Saint-Marcel cave (France), wood barrels and thousands of bottles containing red wine were stored for vinification. After storage began, a fungal and bacterial outbreak occurred, and the area was invaded by numerous types of mold colonizing the cave ceilings and all objects related to human activities (the stairwell and oenological materials). In this study, using the metabarcoding approach, we have studied the microbial outbreak and have linked the identified microorganisms to oenological activity. Both 16S and ITS primers were used to sequence the samples collected from the cave. The results showed that the dominant microorganisms proliferating in the cave were related to wine vinification. For instance, Zasmidium cellare, a strain known for living in dark and ethanol-rich environments, was the dominant fungus on the cave stairwell. Furthermore, Guehomyces pullulans, a cold-adapted yeast used for juice clarification, was recorded as the major species on the blackened limestone ceilings. These findings reveal a complex community structure in the studied cave based on the assembly of bacteria and fungi. Finally, our results demonstrate that oenological activities could seriously affect cave preservation, changing the natural microbial communities populating cave environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

We describe a reference spatial database and four land use maps of Antananarivo city produced over 2017 reference year using a methodology combining machine learning and object based image analysis (OBIA). These maps are produced by processing satellite images using the Moringa land cover processing chain developed in our laboratory. We use a single very high spatial resolution (VHSR) Pleiades image, a time series of Sentinel-2 and Landsat-8 images, a Digital Terrain Model (DTM) and the aforementioned reference database. According to the Moringa workflow, the Pleiades image is used to generate a suitable object layer at VHSR using a segmentation algorithm. Each object is then classified using variables from the time series and information from the DTM. The reference database used to train the supervised classification algorithm is here described, as well as the 4 land cover maps produced at four different hierarchically nested nomenclature levels. For a number of classes going from 2 to 20, overall accuracies range from 94% to 74%. Such land cover products are very rare in Madagascar, so we have decided to make them openly accessible and usable by land managers and researchers., Competing Interests: The authors declare that they have no knowledge of competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article., (© 2020 The Authors.)

Currently, the increasing demand of biopesticides production to replace chemical pesticides which are excessively used has made solid state fermentation (SSF) technology the need of the hour. In spite of advantages, true potential of SSF process has not been fully realized at industrial scale. A fermentation process for 6-pentyl-a-pyrone (6 PP), conidia, and lytic enzymes (cellulases, lipase, amylase) production by Trichoderma asperellum TF1 was scaled-up from 250 mL flasks and glass Raimbault column packed with 20 g of solid substrates (dry weight) to 5 Kg of solid substrate by using a new plastic single used bioreactor. For column and single used bioreactor, the fermentation was done with the application of humid air during all the process however flasks are not hermetically closed that some oxygen could flow by diffusion. T. asperellum growth was investigated using a mixture of vine shoots, jatropha cake, olive pomace and olive oil as substrate in all systems in parallel at 25 °C during 7 days. Overall, the conditions applied on the single used bioreactor resulted in the optimum 6-PP production (7.36 ± 0.37 mg g DM -1 ), lipases (38.73 ± 0.21U/g DM), amylases (15.22 ± 0.13 U/g DM), and conidia production (8.55 ± 0.04 × 10 9 conidia/g DM)., (Copyright © 2019. Published by Elsevier Ltd.)