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Estimates of the activity of antioxidants in the literature often appear inconsistent. In the specific case of the DPPH ∙ test, the diversity of measurements may arise from variations in the protocols followed. This paper proposes an unbiased method which models the reduction mechanism. This method is applied to the reduction of DPPH ∙ by ferulic acid. A scheme with eight coupled reactions is proposed and has been validated on different solvents and using a wide range of DPPH , ferulic acid, and 5,5′-diferulic acid concentrations, and verified using data from the literature on ferulic acid activity. This modeling approach permits a correction to the bias of the 8th reaction (spontaneous reduction of DPPH ), because of its sensitivity to solvent, which in most cases is not taken into account. The best experimental strategy to determine the Efficient Concentration of ferulic acid to reduce 20% (EC20) and 50% (EC50) of DPPH ∙ is then detailed in terms of initial DPPH ∙ concentrations and the duration of the experiment.

Bacteriophages are the most abundant entities found within the human gastrointestinal tract, yettheir interaction with bacterial hosts remain poorly understood, particularly with respect to CRISPRCas immunity. Here, we show that the Type IC CRISPRCas system in the prevalent gut Actinobacterium Eggerthella lenta i s active both transcriptionally and catalytically, cleaving foreign and self DNA. Comparative analyses of E. lenta CRISPRCas systems across genomes and metagenomes revealed two distinct clades according to their shared cas gene sequence similarity and spacer content. To identify putative CRISPR targets, we assembled a human virome database (HuVirDB) encompassing 1,831 samples, revealing matches for the majority of the identified spacers, including “hypertargeted” phage with as many as 96 protospacers. Modeling observed spacer/protospacer pairs, we mapped positional mismatch tolerance in crRNAs. This work emphasizes the utility of merging computational and experimental approaches for determining the function and targets of human gut bacterial CRISPRCas systems.

Optical transport networks are being continuously upgraded to cope with the ever increasing capacity requirements. Improving the energy- and spectral-efficiency while maintaining high service availability is emerging as a strategic priority for the operators. This article proposes a differentiated quality of protection (Diff QoP) scheme to achieve this goal by matching the actual client/service requirements for network protection. This strategy can be especially valuable in future networks where heterogeneous services and users with different requirements will coexist in the network. The applicability of such scheme is evaluated in different network and traffic scenarios, ranging from the conventional current static wavelength-division-multiplexing (WDM) networks to the innovative flexible-grid elastic optical networks (EON).Simulations carried out on realistic deployment scenarios operated with static and dynamic traffic network operations allowed us to quantitatively analyze the potential energy- and spectral-efficiency improvements that a Diff QoP scheme can provide to telecommunication operators with respect to the common dedicated protection 1+1 (DP 1+1).

Bacteriophages are abundant within the human gastrointestinal tract, yet their interactions with gut bacteria remain poorly understood, particularly with respect to CRISPR-Cas immunity. Here, we show that the type I-C CRISPR-Cas system in the prevalent gut Actinobacterium Eggerthella lenta is transcribed and sufficient for specific targeting of foreign and chromosomal DNA. Comparative analyses of E.lenta CRISPR-Cas systems across (meta)genomes revealed 2 distinct clades according to cas sequence similarity and spacer content. We assembled a human virome database (HuVirDB), encompassing 1,831 samples enriched for viral DNA, to identify protospacers. This revealed matches for a majority of spacers, a marked increase over other databases, and uncovered "hyper-targeted" phage sequences containing multiple protospacers targeted by several E.lenta strains. Finally, we determined the positional mismatch tolerance of observed spacer-protospacer pairs. This work emphasizes the utility of merging computational and experimental approaches for determining the function and targets of CRISPR-Cas systems.