Resilin: Elastic MapReduce over Multiple Clouds

The MapReduce programming model, introduced by Google, offers a simple and efficient way of performing distributed computation over large data sets. Although Google's implementation is proprietary, MapReduce can be leveraged by anyone using the free and open-source Apache Hadoop framework. To simplify the usage of Hadoop in the cloud, Amazon Web Services offers Elastic MapReduce, a web service enabling users to run MapReduce jobs. Elastic MapReduce takes care of resource provisioning, Hadoop configuration and performance tuning, data staging, fault tolerance, etc. This service drastically reduces the entry barrier to perform MapReduce computations in the cloud, allowing users to concentrate on the problem to solve. However, Elastic MapReduce is restricted to Amazon EC2 resources, and is provided at an additional cost. In this paper, we present Resilin, a system implementing the Elastic MapReduce API with resources from clouds other than Amazon EC2, such as private and scientific clouds. Furthermore, we explore a feature going beyond the current Amazon Elastic MapReduce offering: performing MapReduce computations over multiple distributed clouds. The evaluation of Resilin shows the benefits of running computations on more than one cloud. While not being the most efficient way to perform Hadoop computations, it solves the problem of resource availability and adds more flexibility regarding the type/price of resource.Le modèle de programmation MapReduce, introduit par Google, offre un moyen simple et efficace de réaliser des calculs distribués sur de grandes quantités de données. Bien que la mise en oeuvre de Google soit propriétaire, MapReduce peut être utilisé librement avec l'environnement Hadoop. Pour simplifier l'utilisation de Hadoop dans les nuages informatiques, Amazon Web Services offre Elastic MapReduce, un service web qui permet aux utilisateurs d'exécuter des applications MapReduce. Il prend en charge l'allocation de ressources, la configuration et l'optimisation de Hadoop, la copie des données, la tolérance aux fautes, etc. Ce service facilite l'exécution d'applications MapReduce dans les nuages informatiques, permettant ainsi aux utilisateurs de se concentrer sur la résolution de leur problème plutôt que sur la gestion de la plate-forme d'exécution. Elastic MapReduce est limité á l'utilisation de ressources fournies par Amazon EC2 et est proposé à un coût additionnel. Dans cet article, nous présentons Resilin, un système mettant en oeuvre l'API Elastic MapReduce avec des ressources provenant d'autres nuages informatiques que Amazon EC2, tels que les nuages privés ou communautaires. De plus, nous explorons une fonctionnalité nouvelle par rapport au service offert par Amazon Elastic MapReduce: l'exécution d'applications MapReduce sur plusieurs nuages géographiquement distribués. L'évaluation de Resilin montre les avantages liés à l'utilisation de plus d'un nuage pour l'exécution d'applications MapReduce. Bien qu'il ne fournisse pas la solution la plus efficace pour l'exécution d'applications MapReduce, Resilin résout le problème de la disponibilité des ressources et ajoute une plus grande flexibilité en ce qui concerne le type et le prix des ressources

Diatoms and their role in aquatic ecosystems

The present article aimed to determine diversity and abundance of diatoms in the river basin of the Cerna River. In order to achieve the objective, samples were taken from the entire course of the river, from 9 specific points (I, II, III, IV, V, VI, VII, VIII, IX) in spring-summer of 2020. 53 species of diatoms classified in 21 genera were determined

Evaluation and monitoring of quorum sensing soluble mediators implicated in the regulation of bacterial growth in Vibrio strains

Abstract Quorum sensing (QS) is an ubiquitary regulation mechanism in the bacterial world implicated in intra and inter-bacterial communication and dependen

Large-vscale hydrogen production and storage technologies: Current status and future directions

This is an accepted manuscript of an article published by Elsevier in International Journal of Hydrogen Energy on 13/11/2020, available online: https://doi.org/10.1016/j.ijhydene.2020.10.110 The accepted version of the publication may differ from the final published version.Over the past years, hydrogen has been identified as the most promising carrier of clean energy. In a world that aims to replace fossil fuels to mitigate greenhouse emissions and address other environmental concerns, hydrogen generation technologies have become a main player in the energy mix. Since hydrogen is the main working medium in fuel cells and hydrogen-based energy storage systems, integrating these systems with other renewable energy systems is becoming very feasible. For example, the coupling of wind or solar systems hydrogen fuel cells as secondary energy sources is proven to enhance grid stability and secure the reliable energy supply for all times. The current demand for clean energy is unprecedented, and it seems that hydrogen can meet such demand only when produced and stored in large quantities. This paper presents an overview of the main hydrogen production and storage technologies, along with their challenges. They are presented to help identify technologies that have sufficient potential for large-scale energy applications that rely on hydrogen. Producing hydrogen from water and fossil fuels and storing it in underground formations are the best large-scale production and storage technologies. However, the local conditions of a specific region play a key role in determining the most suited production and storage methods, and there might be a need to combine multiple strategies together to allow a significant large-scale production and storage of hydrogen.Published versio

Heterogeneous Resource Selection for Arbitrary HPC Applications in the Cloud

International audienceCloud infrastructures offer a wide variety of resources to choose from. However, most cloud users ignore the potential benefits of dynamically choosing cloud resources among a wide variety of VM instance types with different con-figuration/cost tradeoffs. We propose to automate the choice of resources that should be assigned to arbitrary non-interactive applications. During the first executions of the application, the system tries various resource configurations and builds a custom performance model for this application. Thereafter, cloud users can specify their execution time or financial cost constraints, and let the system automatically select the resources which best satisfy this constraint

Evolution of the Online Sales of Sustainable Products in the COVID-19 Pandemic

In the context of the COVID-19 pandemic, online sales have increased in recent years for many products. Responsible consumption has also been considered by households and individuals, and interest in sustainable products has positively evolved. Although sustainable products have more and more been considered by consumers and producers as appropriate alternatives, the results are still underwhelming. This study aims to demonstrate the relationship between the online sales of sustainable products and the online marketing costs expressed by the cost-per-click in Romania in the last three years. This quantitative research is a conclusive and descriptive study based on secondary data sets collected from the evidence registered in an online agency, which, in turn, was based on a sample of companies and products in three industries considered highly open to sustainable approaches: electronics; home and garden; clothing and footwear. The results show different relationships between the online marketing cost and the sales of sustainable products in the above-mentioned industries. In addition, online consumer purchasing intention is a mediator for the relationship between marketing cost and online sales in one industry only, namely electronics. The study reveals the development of the online transactions of sustainable products, considering the connection between marketing costs and subsequent sales

Evolution of the Online Sales of Sustainable Products in the COVID-19 Pandemic

In the context of the COVID-19 pandemic, online sales have increased in recent years for many products. Responsible consumption has also been considered by households and individuals, and interest in sustainable products has positively evolved. Although sustainable products have more and more been considered by consumers and producers as appropriate alternatives, the results are still underwhelming. This study aims to demonstrate the relationship between the online sales of sustainable products and the online marketing costs expressed by the cost-per-click in Romania in the last three years. This quantitative research is a conclusive and descriptive study based on secondary data sets collected from the evidence registered in an online agency, which, in turn, was based on a sample of companies and products in three industries considered highly open to sustainable approaches: electronics; home and garden; clothing and footwear. The results show different relationships between the online marketing cost and the sales of sustainable products in the above-mentioned industries. In addition, online consumer purchasing intention is a mediator for the relationship between marketing cost and online sales in one industry only, namely electronics. The study reveals the development of the online transactions of sustainable products, considering the connection between marketing costs and subsequent sales

Revealing the CRISPR array in bacteria living in our organism

CRISPR (clustered regularly interspaced short palindromic repeats) is an immune system used by bacteria to defend themselves from different types of pathogens. It was discovered that this immune system can modify itself in specific regions called spacers due to previous interaction with foreign genetic material from phages and plasmids. Through our research, we have identified in different bacterial isolates CRISPR arrays belonging to the subtypes I-E (present in 42 samples) and I-F (present in 9 samples). The number of spacers in CRISPR arrays was also estimated based on the array length as a possible connection with the systems activity. Our results yielded arrays as small as 200 bp and as large as 1400 bp. Dobrescu et al (PDF) Article history: Received: 31 March 2022; Revised: 27 April 2022; Accepted: 9 June 2022; Available online: 30 June 2022

Correlation between CRISPR Loci Diversity in Three Enterobacterial Taxa

CRISPR-Cas is an adaptive immunity system of prokaryotes, composed of CRISPR arrays and the associated proteins. The successive addition of spacer sequences in the CRISPR array has made the system a valuable molecular marker, with multiple applications. Due to the high degree of polymorphism of the CRISPR loci, their comparison in bacteria from various sources may provide insights into the evolution and spread of the CRISPR-Cas systems. The aim of this study was to establish a correlation between the enterobacterial CRISPR loci, the sequence of direct repeats (DR), and the number of spacer units, along with the geographical origin and collection source. For this purpose, 3474 genomes containing CRISPR loci from the CRISPRCasdb of Salmonella enterica, Escherichia coli, and Klebsiella pneumoniae were analyzed, and the information regarding the isolates was recorded from the NCBI database. The most prevalent was the I-E CRISPR-Cas system in all three studied taxa. E. coli also presents the I-F type, but in a much lesser percentage. The systems found in K. pneumoniae can be classified into I-E and I-E*. The I-E and I-F systems have two CRISPR loci, while I-E* has only one locus upstream of the Cas cluster. PCR primers have been developed in this study for each CRISPR locus. Distinct clustering was not evident, but statistically significant relationships occurred between the different CRISPR loci and the number of spacer units. For each of the queried taxa, the number of spacers was significantly different (p < 0.01) by origin (Africa, Asia, Australia and Oceania, Europe, North America, and South America) but was not linked to the isolation source type (human, animal, plant, food, or laboratory strains)