Evolutive emergence and divergence of an Ig regulatory node: An environmental sensor getting cues from the aryl hydrocarbon receptor?

One gene, the immunoglobulin heavy chain (IgH) gene, is responsible for the expression of all the different antibody isotypes. Transcriptional regulation of the IgH gene is complex and involves several regulatory elements including a large element at the 3’ end of the IgH gene locus (3’RR). Animal models have demonstrated an essential role of the 3’RR in the ability of B cells to express high affinity antibodies and to express different antibody classes. Additionally, environmental chemicals such as aryl hydrocarbon receptor (AhR) ligands modulate mouse 3’RR activity that mirrors the effects of these chemicals on antibody production and immunocompetence in mouse models. Although first discovered as a mediator of the toxicity induced by the high affinity ligand 2,3,7,8-tetracholordibenzo-p-dioxin (dioxin), understanding of the AhR has expanded to a physiological role in preserving homeostasis and maintaining immunocompetence. We posit that the AhR also plays a role in human antibody production and that the 3’RR is not only an IgH regulatory node but also an environmental sensor receiving signals through intrinsic and extrinsic pathways, including the AhR. This review will 1) highlight the emerging role of the AhR as a key transducer between environmental signals and altered immune function; 2) examine the current state of knowledge regarding IgH gene regulation and the role of the AhR in modulation of Ig production; 3) describe the evolution of the IgH gene that resulted in species and population differences; and 4) explore the evidence supporting the environmental sensing capacity of the 3’RR and the AhR as a transducer of these cues. This review will also underscore the need for studies focused on human models due to the premise that understanding genetic differences in the human population and the signaling pathways that converge at the 3’RR will provide valuable insight into individual sensitivities to environmental factors and antibody-mediated disease conditions, including emerging infections such as SARS-CoV-2

From rods to helices: evidence of a screw-like nematic phase

Evidence of a special chiral nematic phase is provided using numerical simulation and Onsager theory for systems of hard helical particles. This phase appears at the high density end of the nematic phase, when helices are well aligned, and is characterized by the C$_2$ symmetry axes of the helices spiraling around the nematic director with periodicity equal to the particle pitch. This coupling between translational and rotational degrees of freedom allows a more efficient packing and hence an increase of translational entropy. Suitable order parameters and correlation functions are introduced to identify this screw-like phase, whose main features are then studied as a function of radius and pitch of the helical particles. Our study highlights the physical mechanism underlying a similar ordering observed in colloidal helical flagella [E. Barry et al. \textit{Phys. Rev. Lett.} \textbf{96}, 018305 (2006)] and raises the question of whether it could be observed in other helical particle systems, such as DNA, at sufficiently high densities.Comment: List of authors correcte

Postharvest behaviour of minimally processed watercress

16-18Watercress (Nasturtium officinale R. Br.) is an aquatic plant of the Brassicaceae family and used as a leafy vegetable that grows in and around water. It is consumed raw or steamed and has a short shelf life of approximately seven days. The objective of this study was to evaluate the postharvest behaviour of watercress minimally processed and stored at optimal storage temperature vs. market temperature. Treatments were: shoots packed with plain film (PD961EZ, 31µm thickness) and stored in refrigerated chambers at 1 ± 0.5 oC and 8 ± 2 oC for 10 days. Overall visual quality, gas concentration inside the packages, chlorophyll, reducing sugar, ascorbic acid, oxalic acid and weight loss were evaluated. At the end of the storage period overall visual quality, gas concentration and reducing sugars were affected by storage time and temperature, whereas dehidro ascorbic, oxalic acid and weight loss were not

Postharvest behaviour of minimally processed watercress

16-18Watercress (Nasturtium officinale R. Br.) is an aquatic plant of the Brassicaceae family and used as a leafy vegetable that grows in and around water. It is consumed raw or steamed and has a short shelf life of approximately seven days. The objective of this study was to evaluate the postharvest behaviour of watercress minimally processed and stored at optimal storage temperature vs. market temperature. Treatments were: shoots packed with plain film (PD961EZ, 31µm thickness) and stored in refrigerated chambers at 1 ± 0.5 oC and 8 ± 2 oC for 10 days. Overall visual quality, gas concentration inside the packages, chlorophyll, reducing sugar, ascorbic acid, oxalic acid and weight loss were evaluated. At the end of the storage period overall visual quality, gas concentration and reducing sugars were affected by storage time and temperature, whereas dehidro ascorbic, oxalic acid and weight loss were not

Identità e relazioni sociali. Dai popoli migranti alla cultura del Web 2.0

Nel saggio è una riflessione preliminare su cos'è da intendere per identità prima di individuare il ruolo che svolge la comunicazione non solo nel mantenere ma anche e soprattutto nel costruire identità e nel gestire relazioni, nel senso di crearle, mutarle o annullarle.The essay is a reflection about identity and role of communication on creating, mantaining and destroying social relations

Robustness and modularity properties of a non-covalent DNA catalytic reaction

The biophysics of nucleic acid hybridization and strand displacement have been used for the rational design of a number of nanoscale structures and functions. Recently, molecular amplification methods have been developed in the form of non-covalent DNA catalytic reactions, in which single-stranded DNA (ssDNA) molecules catalyze the release of ssDNA product molecules from multi-stranded complexes. Here, we characterize the robustness and specificity of one such strand displacement-based catalytic reaction. We show that the designed reaction is simultaneously sensitive to sequence mutations in the catalyst and robust to a variety of impurities and molecular noise. These properties facilitate the incorporation of strand displacement-based DNA components in synthetic chemical and biological reaction networks

Analysis of four new enterococcus faecalis phages and modeling of a hyaluronidase catalytic domain from saphexavirus

Background: Phage therapy (PT), as a method to treat bacterial infections, needs identification of bacteriophages targeting specific pathogenic host. Enterococcus faecalis, a Gram-positive coccus resident in the human gastrointestinal tract, may become pathogenic in hospitalized patients showing acquired resistance to vancomycin and thus representing a possible target for PT. Materials and Methods: We isolated four phages that infect E. faecalis and characterized them by host range screening, transmission electron microscopy, and genome sequencing. We also identified and three-dimensional modeled a new hyaluronidase enzyme. Results: The four phages belong to Siphoviridae family: three Efquatrovirus (namely vB_EfaS_TV51, vB_EfaS_TV54, and vB_EfaS_TV217) and one Saphexavirus (vB_EfaS_TV16). All of them are compatible with lytic cycle. vB_EfaS_TV16 moreover presents a gene encoding for a hyaluronidase enzyme. Conclusions: The identified phages show features suggesting their useful application in PT, particularly the Saphexavirus that may be of enhanced relevance in PT because of its potential biofilm-digestion capability

Spaceship Earth. Space-driven technologies and systems for sustainability on ground

As awareness towards the problem is growing, eco-friendliness is today a paramount requirement for all space activities and in particular for the ground segment, fully comparable to other industrial sectors. The present work focuses on the assessment and the sustainable development enhancement of a ground-based space facility, the European Astronaut Centre (EAC), located in Germany. The project is framed within the European Space Agency development of an environmental outlook, which aims not only at the full compliance with the legislation and at assessing the impact of its activities, but also at laying the foundation for future evolution through innovation. Indeed, ESA promotes the sustainable use of space as a necessity and duty for Europe. As history teaches us, technical knowledge emerged within the space sector serves as innovation driver in other industrial branches: the goal of the project is to transform the EAC building into a spaceship integrated with the territory through the conscious management of this spontaneous process, fostering the combination between the space sector and the architecture and civil engineering fields. The work explores the potential of space technologies, processes and systems applied on ground and presents a range of space-driven innovative concepts which may improve the sustainability of the EAC building, focusing on different aspects of its resource demand – energy, water and waste management – and defining the integration with the pre-existing compound, the limitation of the impact on the surrounding landscape and the participation of the local community as additional fundamental requirements. Indeed, the project embraces the full concept of sustainability, which considers not only eco-friendliness but also its balance with economic and social aspects. Two factors – a certain urgency for action, which leaves little space for research and experimentation, and a call for ground-breaking solutions – guided the design activity: taking advantage of these conflicting requirements, a comparison between standard technologies and innovative space-related concepts was performed. When dealing with complex and uncertain scenarios, decision among the possible solutions is not straightforward and needs to be supported by appropriate methodologies: a multi-criteria and quantitative decision-making tool, able to concentrate on the main goal while considering all other relevant aspects – environmental, economic, social sustainability – was therefore developed. Furthermore, the project promotes local community participation in the decisional process, as a way to enhance knowledge, generate understanding and promote towards the EAC redesign, space activities and their potential innovative impact on sustainability

Evolution of human IgH3 ' EC duplicated structures: both enhancers HS1,2 are polymorphic with variation of transcription factor's consensus sites

The enhancer complex regulatory region at the 3' of the immunoglobulin heavy cluster (IgH3'EC) is duplicated in apes along with four constant genes and the region is highly conserved throughout humans. Both human IgH3'ECs consist of three loci high sensitive (HS) to DNAse I with enhancer activity. It is thus possible that the presence of structural divergences between the two IgH3'ECs and of relative polymorphisms correspond to functional regulatory changes. To analyse the polymorphisms of these almost identical regions, it resulted mandatory to identify the presence of divergent sequences, in order to select distinctive primers for specific PCR genomic amplifications. To this aim, we first compared the two entire IgH3'ECs in silicio, utilising the updated GenBank (GB) contigs, then we analysed the two IgH3'ECs by cloning and sequencing amplicons from independent genomes. In silicio analysis showed that several inversions, deletions and short insertions had occurred after the duplication. We analysed in detail, by sequencing specific regions, the polymorphisms occurring in enhancer HS1,2-A (which lies in IgH3'EC-1, 3' to the C alpha-1 gene) and in enhancer HS1,2-B (which lies in IgH3'EC-2, 3' to C alpha-2). Polymorphisms are due to the repetition (occurring one to four times) of a 38-bp sequence present at the 3' of the core of enhancers HS1,2. The structure of both human HS1,2 enhancers has revealed not yet described polymorphic features due to the presence of variable spacer elements separating the 38-bp repetitions and to variable external elements bordering the repetition cluster. We found that one of the external elements gave rise to a divergent allele 3 in the two clusters. The frequency of the different alleles of the two loci varies in the Italian population and allele 3 of both loci are very rare. The analysis of the Callicebus moloch, Gorilla gorilla and Pan troglodytes HS1,2 enhancers showed the transformation from the ancestral structure with the 31- to the 17-by external element in hominids. The relevance of the polymorphisms in the HS1,2 enhancers is due to the variable number of binding sites for the transcription factors: NF-kappa B, CMYB, BSAP1/2, AP1/4, E47, MyoD and mu E5 and thus to the possible influence of these variations on switch, production of Ig and on maturation of B cells. (c) 2004 Elsevier B.V. All rights reserved

Effect Of Light Environment On Harvest Quality And Postharvest Behavior Of Minimally Processed Sweet Pepper

The aim of this study was to evaluate the effect of two light environments on two maturity stages of sweet pepper and the postharvest behavior of minimally processed product using passive modified atmosphere. The size and fruit morphology were measured at harvest. Overall visual quality, gas concentration inside the bags, weight loss, soluble solids, firmness, electrolyte leakage, carotenoids and ascorbic acid were determined during the storage period. Results showed that quality parameters were affected by radiation and processing. Shaded pepper fruits showed higher water content and lower size compared to fruits exposed to full radiation. Fruit nutritional value was maintained, but after six days was not marketable. Visual quality of intact fruit was not affected without differences between treatments. Shelf life processed red fruits as julienne was reduced, being the worst performing during storage. Post-harvest visual quality was in relation to gases composition (O2 and CO2) inside the trays