Exploring the flexibility of network access control in the Recursive InterNetwork Architecture

International audienceRINA (Recursive InterNetwork Architecture) is a promising network architecture based on the concept of distributed Inter Process Communications (IPC). In RINA there is a single type of programmable layer (the DIF "Distributed IPC Facility"), that repeats as many times as needed by the network designer. Each layer is composed of only two programmable protocols: one performs data transfer and data transfer control functions, while the other carries out layer management functions. Multiple policies can be plugged to both protocols at each layer to adapt them to operational requirements. In this paper we explore the advantages of the RINA architecture on the access control area with respect to the IP protocol suite, specially regarding layer management functions. By designing and implementing a capability-based access control policy we show that RINA allows finer granularity in access control decisions than current approaches. Moreover, the policy can be applied to any layer in the network, maximizing the re-use of specifications and implementation

Chitosan Treatment of E-11 Cells Modulates Transcription of Nonspecific Immune Genes and Reduces Nodavirus Capsid Protein Gene Expression

This study explores whether crustacean products inhibit viral infections in aquaculture. Chitosan (CHT) was extracted from waste products of Parapenaeus longirostris. Biochemical composition, viscosity measurement, molecular weight, structure and cytotoxicity tests were used to characterize the extracted chitosan. Cultures of E-11 cells derived from snakehead Ophicephalus striatus were inoculated with 106.74 TCID50 of an isolate of betanodavirus genotype RGNNV (redspotted grouper nervous necrosis virus) after being treated with solutions of 0.3% CHT for 1 h at room temperature. The antiviral effect of CHT was assessed by comparing the ability of RGNVV to replicate and produce cytopathic effects on CHT-treated cell cultures. The change in RNA expression levels of the nodavirus capsid protein gene and three mediator genes in infected cells with or without CHT treatment was evaluated by qPCR. Changes in gene expression compared to control groups were monitored at 6, 24, 48 and 71 h post treatment in all target gene transcripts. The CCR3 expression in CHT treated cells showed a significant increase (p < 0.05) until day 3. On the other hand, the expression of TNF-α decreased significantly (p < 0.05) in CHT treated cells throughout the experimental period. Likewise, the expression of the IL-10 gene showed a significant downregulation in CHT treated cells at all time points (p ≤ 0.05). As further evidence of an antiviral effect, CHT treatment of cells produced a reduction in virus load as measured by a reduced expression of the viral capsid gene and the increase in RQ values from 406 ± 1.9 at hour 1 to 695 ± 3.27 at 72 h post inoculation. Statistical analysis showed that the expression of the viral capsid gene was significantly lower in cells treated with chitosan (p ≤ 0.05). These results improve our knowledge about the antiviral activity of this bioactive molecule and highlight its potential use in fish feed industry

Direct Amperometric Sensing of Fish Nodavirus RNA Using Gold Nanoparticle/DNA-Based Bioconjugates

We describe the design of a simple and highly sensitive electrochemical bioanalytical method enabling the direct detection of a conserved RNA region within the capsid protein gene of a fish nodavirus, making use of nanostructured disposable electrodes. To achieve this goal, we select a conserved region within the nodavirus RNA2 segment to design a DNA probe that is tethered to the surface of nanostructured disposable screen-printed electrodes. In a proof-of-principle test, a synthetic RNA sequence is detected based on competitive hybridization between two oligonucleotides (biotinylated reporter DNA and target RNA) complimentary to a thiolated DNA capture probe. The method is further validated using extracted RNA samples obtained from healthy carrier Sparus aurata and clinically infected Dicentrarchus labrax fish specimens. In parallel, the sensitivity of the newly described biosensor is compared with a new real-time RT-PCR protocol. The current differences measured in the negative control and in presence of each concentration of target RNA are used to determine the dynamic range of the assay. We obtain a linear response (R2 = 0.995) over a range of RNA concentrations from 0.1 to 25 pM with a detection limit of 20 fM. The results are in good agreement with the results found by the RT-qPCR. This method provides a promising approach toward a more effective diagnosis and risk assessment of viral diseases in aquaculture

Exploration of bacterial diversity in leaves and rhizosphere soil of flood affected and unaffected apricot trees

International audiencePlants harbor diverse and taxonomically structured communities of protective microorganisms that confer beneficial characteristics in plant growth and protection against biotic and abiotic stresses. The aim of this study is to characterize the composition of endophytic bacterial communities in leaves and rhizobacterial communities of the flood affected and unaffected apricot trees by 16S rRNA genes metabarcoding. Results showed a slight bacterial diversity reduction in flood affected condition compared to the unaffected one. The relative bacterial abundance analysis showed that the bacterial taxa were almost uniformly distributed between the leaves. However, a clear differential taxa abundance was observed in rhizosphere soil which may be associated with apricot tree environmental status. In fact, the flood affected rhizosphere soil showed a significant increase in several bacterial taxa including particularly Bacillusfrigoritolerans and Pseudoarthrobacterphenanthrenivorans which are known to be beneficial to soil. However, some Actinobacteria genera that promote growth of plants, including Nocardioidessp.,Streptomycessp.,BlastococcusandGeodermatophilus were decreased in abundance. This distribution of abundance and diversity of the bacterial community in the flood affected tree can be correlated to abiotic stress. These results provide new insights into rhizosphere-associated microbes that are likely playing a crucial role in plant growth and survival

Progetto CELAVIE: descrizione metodologica per la produzione acquaponica di animali e piante

Scopo del presente report tecnico è la presentazione della tecnica di Acquaponica impiegata nell’ambito del progetto CELAVIE, programma di Cooperazione transfrontaliera Italia-Tunisia e ubicata presso il centro di sperimentazione della “cellula per la vita”. L’acquaponica è una tecnica agricola innovativa che porta benefici, sia agli agricoltori che all’ambiente. La gestione efficiente dell’acqua, la riciclabilità dei nutrienti e la maggiore produttività sono solo alcuni dei benefici che questa tecnica di coltivazione porta con sé (Manuale FAO, 2019). L'impianto realizzato a Palermo e a Sfax acquisisce dati utili allo studio dell’ambiente esterno, del terreno circostante e dell’ambiente interno alla cellula