Noise processing by microRNA-mediated circuits: The Incoherent Feed-Forward Loop, revisited

The intrinsic stochasticity of gene expression is usually mitigated in higher eukaryotes by post-transcriptional regulation channels that stabilise the output layer, most notably protein levels. The discovery of small non-coding RNAs (miRNAs) in specific motifs of the genetic regulatory network has led to identifying noise buffering as the possible key function they exert in regulation. Recent in vitro and in silico studies have corroborated this hypothesis. It is however also known that miRNA-mediated noise reduction is hampered by transcriptional bursting in simple topologies. Here, using stochastic simulations validated by analytical calculations based on van Kampen's expansion, we revisit the noise-buffering capacity of the miRNA-mediated Incoherent Feed Forward Loop (IFFL), a small module that is widespread in the gene regulatory networks of higher eukaryotes, in order to account for the effects of intermittency in the transcriptional activity of the modulator gene. We show that bursting considerably alters the circuit's ability to control static protein noise. By comparing with other regulatory architectures, we find that direct transcriptional regulation significantly outperforms the IFFL in a broad range of kinetic parameters. This suggests that, under pulsatile inputs, static noise reduction may be less important than dynamical aspects of noise and information processing in characterising the performance of regulatory elements

The spread of Caulerpa cylindracea in Calabria (Italy) and the effects of shipping activities

A survey to state the spread of Caulerpa cylindracea in the Calabrian Tyrrhenian coasts has been undertaken. The research aims to value the role of shipping activities in the ten-year’s study from 1999 to 2009, as a vector in the spreading of the species. The outcome of this study has shown that, during the last ten years, the species has colonized most of the regional coastline, on all kinds of substrata, in areas closed to harbours and subjected to high rate of sedimentation. The main effects of Caulerpa cylindracea colonization have resulted in a gradual decrease of crustose species while the turf ones have increased their abundance, altering the native structure of the macroalgal assemblages. These results confirm the extremely invasive behaviour of this strain in the Calabrian Tyrrhenian coasts and, more generally, in the Mediterranean Sea

The alien alga Caulerpa taxifolia (Vahl) C. Agardh var. distichophylla (Sonder) Verlaque, Huisman and Procaccini move their northern and western limits.

Caulerpa taxifolia (Vahl) C. Agardh var. distichophylla (Sonder) Verlaque, Huisman and Procacini is a green invasive alga recently reported in the Mediterranean Sea for the first time in 2007. The first record was in Turkey in 2007 and later it has been reported in Sicily (Italy, in 2009), Cyprus (in 2013), Malta (in 2015), Rhodes (in 2016) and Lybia (2017). In the current study we present additional records of this species which expanding its range into the Eastern and Western Mediterranean Sea (Eastern and Western Sicilian shoreline, Calabrian Tyrrhenian coast, Sardinia and Tunisia) as well as in the eastern Mediterranean basin. Our specimens were collected on various substrates and were identified trough morphological methods

Levels of heavy metals in wetland and marine vascular plants and their biomonitoring potential : a comparative assessment

The present study investigated the levels of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn in the seagrasses Posidonia oceanica and Cymodocea nodosa, and in the wetland macrophytes Phragmites australis, Arundo donax, Typha domingensis, Apium nodiflorum, and Nasturtium officinale. Results showed that the bioaccumulation capacity from sediments, translocation, total levels in plant tissues, and bioindication of metals in sediments, are generally species-specific. In particular, the patterns of metals in the aquatic plants studied were overall independent of ecology (coasts vs wetlands), biomass, anatomy (rhizomatous vs non rhizomatous plants), and life form (hemicrytophytes vs hydrophytes). However, marine phanerogams and wetland macrophytes shared some characteristics such as high levels of heavy metals in their below-ground organs, similar capacity of element translocation in the rhizosphere, compartmentalization of metals in the different plant organs, and potential as bioindicators of Cu, Mn and Zn levels in the substratum. In particular, the present findings indicate that, despite ecological and morphological similarities, different plant species tend to respond differently to exposure to heavy metals. Furthermore, this seems to result from the species individual ability to accumulate and detoxify the various metals rather than being attributed to differences in their ecological and morpho-anatomical characteristics.peer-reviewe

Kinetic Modeling of Solketal Synthesis from Glycerol and Acetone Catalyzed by an Iron(III) Complex

In the last few years, the depletion of the fossil sources and their negative effect on the environment has led to find new alternatives; among these, biodiesel is considered one of the most promising for this purpose. Biodiesel can be produced from the transesterification of vegetable oils or animal fats, obtaining glycerol as a by-product. Glycerol can be used in different processes and one of the most interesting is the condensation with acetone to produce solketal. Among its applications, plasticizers, solvents, and pharmaceutical formulations are the most common. In this work, the attention was focused on the reaction between glycerol and acetone to give solketal promoted by an iron(III) complex. The reaction mechanism was hypothesized, and the kinetics was studied in a batch reactor. Finally, the thermodynamic and kinetic parameters were determined with a reliable model investigating the phenomena that occurred in the reaction network. Keywords

Biochemical data from the characterization of a new pathogenic mutation of human pyridoxine-5'-phosphate oxidase (PNPO)

PNPO deficiency is responsible of severe neonatal encephalopathy, responsive to pyridoxal-5’-phosphate (PLP) or pyridoxine. Recent studies widened the phenotype of this condition and detected new genetic variants on PNPO gene, whose pathogenetic role and clinical expression remain to be established. One of these mutations, Arg116Gln, is of particular interest because of its later onset of symptoms (beyond the first months of life) and its peculiar epileptic manifestations in patients. This protein variant was expressed as recombinant protein in E coli, purified to homogeneity, and characterized with respect to structural and kinetic properties, stability, binding constants of cofactor flavin mononucleotide (FMN) and product (PLP) in order to define the molecular and structural bases of its pathogenicity. For interpretation and discussion of reported data, together with the description of clinical studies, refer to the article [7][1] (doi: 10.1016/j.ymgme.2017.08.003)

Heuristic Algorithm for the Analysis of Fast Field Cycling (FFC) NMR Dispersion Curves

Evaluation of nuclear magnetic relaxation dispersion (NMRD) curves obtained by the fast field cycling nuclear magnetic resonance (FFC-NMR) relaxometry technique is a valuable tool for analyzing the microscopic dynamics of condensed matter systems. However, quantitative data analysis involves several conceptual and practical issues. Moving forward from previous literature approaches, we propose a new analysis method, relying on the elaboration of the inverse integral transform of the NMRD curve. Our approach results in a true heuristic method, able to unambiguously individuate the dynamic domains in the system, thereby avoiding the possible introduction of any element of discretion. The analysis of some data sets relevant to real samples suggests the possibility that the results obtained with the heuristic method may be actually led back to some distinct physical/chemical features of the systems

Role of VEGF, Nitric Oxide, and Sympathetic Neurotransmitters in the Pathogenesis of Tendinopathy: A Review of the Current Evidences

Chronic tendinopathy is a painful common condition affecting athletes as well as the general population undergoing to tendon overuse. Although its huge prevalence, little is known about tendinopathy pathogenesis, and even cloudier is its treatment. Traditionally, tendinopathy has been defined as a lack of tendon ability to overcome stressing stimuli with appropriate adaptive changes. Histologic studies have demonstrated the absence of inflammatory infiltrates, as a consequence conventional antinflammatory drugs have shown little or no effectiveness in treating tendinopathies. New strategies should be therefore identified to address chronic tendon disorders. Angiofibroblastic changes have been highlighted as the main feature of tendinopathy, and vascular endothelial growth factor (VEGF) has been demonstrated as one of the key molecules involved in vascular hyperplasia. More recently, attention has been focused on new peptides such as Substance P, nitric oxide, and calcitonin gene-related peptide (CGRP). Those new findings support the idea of a nerve-mediated disregulation of tendon metabolism. Each of those molecules could be a target for new treatment options. This study aimed to systematically review the current available clinical and basic science in order to summarize the latest evidences on the pathophysiology and its effect on treatment of chronic tendinopathy, and to spread suggestions for future research on its treatment

Reconstructing Hydrothermal Fluid Pathways and Storage at the Solfatara Crater (Campi Flegrei, Italy) Using Seismic Scattering and Absorption

Imaging of fluid pathways is crucial to characterize processes taking place in hydrothermal systems, a primary cause of volcanic unrest and associated hazards. The joint imaging of seismic absorption and scattering is an efficient instrument to map fluid flow at crustal scale, and specifically in volcanoes; however, this technique has so far been applied to image volcanoes and hydrothermal systems at the kilometre scale. Here, we use data from a meter-scale, active seismic survey inside the shallow structure of the Solfatara crater to obtain the first frequency-dependent near-surface scattering and absorption model of a hydrothermal system. The Solfatara crater is the place used to monitor historic unrest at Campi Flegrei caldera (Italy), a high-risk volcano under continuous surveillance due to its closeness to a densely populated area. Improving the imaging of the shallow part of this system is crucial to broaden the understanding of unrest processes that are progressively characterizing other portions of the eastern caldera. The scattering contrasts highlight the primary structural feature, a fault separating the hydrothermal plume from zones of CO2 saturation nearing fumaroles. While high-absorption anomalies mark zones of high soil temperatures and CO2 fluxes, low-absorption anomalies indicate zones of very shallow upflow and are caused by contrasts between liquid-rich and vapour-rich fluids coming from mud pools and fumaroles, respectively. All maps show a SW-NE trend in anomalies consistent with fluid-migration pathways towards the eastern fumaroles. The results provide structural constraints that clarify mechanisms of fluid migration inside the crater. The techniques offer complementary geophysical images to the interpretation of hydrothermal processes and prove that seismic attenuation measurements are suitable to map fluid pathways in heterogeneous media at a detailed scale