Effect of ELF e.m. fields on metalloprotein redox-active sites

The peculiarity of the distribution and geometry of metallic ions in enzymes pushed us to set the hypothesis that metallic ions in active-site act like tiny antennas able to pick up very feeble e.m. signals. Enzymatic activity of Cu2+, Zn2+ Superoxide Dismutase (SOD1) and Fe2+ Xanthine Oxidase (XO) has been studied, following in vitro generation and removal of free radicals. We observed that Superoxide radicals generation by XO is increased by a weak field having the Larmor frequency fL of Fe2+ while the SOD1 kinetics is sensibly reduced by exposure to a weak field having the frequency fL of Cu2+ ion.Comment: 18 pages, 4 figure

Protein families, natural history and biotechnological aspects of spider silk.

Spiders are exceptionally diverse and abundant organisms in terrestrial ecosystems and their evolutionary success is certainly related to their capacity to produce different types of silks during their life cycle, making a specialized use on each of them. Presenting particularly tandemly arranged amino acid repeats, silk proteins (spidroins) have mechanical properties superior to most synthetic or natural high-performance fibers, which makes them very promising for biotechnology industry, with putative applications in the production of new biomaterials. During the evolution of spider species, complex behaviors of web production and usage have been coupled with anatomical specialization of spinning glands. Spiders retaining ancestral characters, such as the ones belonging to the Mygalomorph group, present simpler sorts of webs used mainly to build burrows and egg sacs, and their silks are produced by globular undifferentiated spinning glands. In contrast, Araneomorphae spiders have a complex spinning apparatus, presenting up to seven morphologically distinct glands, capable to of rigidness and elasticity associated with distinct behaviors. Aiming to provide a discussion involving a number of spider silks? biological aspects, in this review we present descriptions of members from each family of spidroin identified from five spider species of the Brazilian biodiversity, and an evolutionary study of them in correlation with the anatomical specialization of glands and spider?s spinning behaviors. Due to the biotechnological importance of spider silks for the production of new biomaterials, we also discuss about the new possible technical and biomedical applications of spider silks and the current status of it

Molecular, behavioral and anatomical sophistication in spider webs: insights from spinning gland RNA-seq experiments in primitive and modern spiders.

RNA-seq experiments conducted in 454 sequencers were carried out to produce 87.000 short-reads representing the transcriptome of two spiders'spinning glands. We produced sequences from (i) Actinopus sp., a spider from the Mygalomorphae clade, and (ii) Gasteracantha cancriformis, an Orbicularia spider. Mygalomorphae spiders are known to retain a number of primitive morphological and behavioral characters. They use mixtures of a primitive web, soil, and plants only to cover a burrow they make on the ground for shelter and predation.On the other hand, Orbicularia spiders show a number of derivative spider's characters and they are capable to build different and complex silks used in a variety of situations. It is interesting to note that the complexity of web production, usage and behavior in these spiders is reflected both by (i) the variety of the repertoire of protein molecules (spidroins) they use to make their webs and (ii) the complexity of their anatomical spinning gland apparatu used to produce silk. Here we have first conducted a broad analysis of the spinning gland transcriptome in both spiders producing unigenes and categorizing annotated genes in biological functions.Then we started to analyze the number and variety of spider silk proteins and families found in different spider clades.We have shown that spiders using web only for a limited number of situations present a less sophisticated morphological spinning apparatus and produce a small repertoire of spidroin molecules. Phylogenetic analyses were conductedin the 3'region of spidroins and we try to relate (i) the evolution of silk protein families,(ii) the evolutionary complexification of silk production behavior and web usage, and (iii) the appearance of new specialized spinning glands along the evolution of specimens and clades in the Araneae order

Optimal portfolio choice with path dependent labor income: the infinite horizon case

We consider an infinite horizon portfolio problem with borrowing constraints, in which an agentreceives labor income which adjusts to financial market shocks in a path dependent way. Thispath-dependency is the novelty of the model, and leads to an infinite dimensional stochasticoptimal control problem. We solve the problem completely, and find explicitly the optimalcontrols in feedback form. This is possible because we are able to find an explicit solutionto the associated infinite dimensional Hamilton-Jacobi-Bellman (HJB) equation, even if stateconstraints are present. To the best of our knowledge, this is the first infinite dimensionalgeneralization of Merton’s optimal portfolio problem for which explicit solutions can be found.The explicit solution allows us to study the properties of optimal strategies and discuss theirfinancial implications

Microbial ecology-based methods to characterize the bacterial communities of non-model insects

Among the animals of the Kingdom Animalia, insects are unparalleled for their widespread diffusion, diversity and number of occupied ecological niches. In recent years they have raised researcher interest not only because of their importance as human and agricultural pests, disease vectors and as useful breeding species (e.g. honeybee and silkworm), but also because of their suitability as animal models. It is now fully recognized that microorganisms form symbiotic relationships with insects, influencing their survival, fitness, development, mating habits and the immune system and other aspects of the biology and ecology of the insect host. Thus, any research aimed at deepening the knowledge of any given insect species (perhaps species of applied interest or species emerging as novel pests or vectors) must consider the characterization of the associated microbiome. The present review critically examines the microbiology and molecular ecology techniques that can be applied to the taxonomical and functional analysis of the microbiome of non-model insects. Our goal is to provide an overview of current approaches and methods addressing the ecology and functions of microorganisms and microbiomes associated with insects. Our focus is on operational details, aiming to provide a concise guide to currently available advanced techniques, in an effort to extend insect microbiome research beyond simple descriptions of microbial communities

Making better use of local data in flood frequency estimation

Flood frequency estimates are an essential part of flood risk management. They are an important ingredient of many important decisions, informing the cost-effectiveness, design and operation of flood defences, flood mapping and planning decisions in flood risk areas. They also inform the National Flood Risk Assessment, the setting of insurance premiums and long-term investment planning. Methods described in the Flood Estimation Handbook (FEH) published in 1999, and many subsequent updates, are considered the industry standard for flood estimation in the UK. They are used extensively by hydrologists from both the public and private sectors. Flood frequency estimates – also known as design flood estimates – are associated with many sources of uncertainty. These hydrological uncertainties often constitute the most uncertain component in any flood study. Uncertainty can lead to difficulty in having confidence in the outputs of studies, whether these are for investment planning, insurance, asset design, development planning or other purposes. As a result, there is considerable benefit to be gained from any reduction in the uncertainty of flood frequency estimation. There are many supplementary sources of information that can help to refine estimates of design floods and potentially reduce uncertainty. Examples include long-term flood history, river level records, photographs of floods and information obtained from field visits. These and similar types of information are defined as ‘local data’. The FEH Local research project aimed to: quantify the uncertainty of design floods estimated from FEH methods develop procedures and guidance for incorporating local and historical data into flood estimation to reduce uncertainties The primary objective of this report is to describe the reviews and research carried out during the FEH Local project. Another output from the project was a document giving guidance to practitioners on how to estimate uncertainty in flood frequency and how to find and incorporate local data. The practitioner guidance, ‘Using Local Data to Reduce Uncertainty in Flood Frequency Estimation’, will be disseminated early in 2017. This report aims to avoid duplication with the practitioner guidance and so is intended mainly for those with an interest in the background to the methods presented in the guidance

Exploring E-cadherin-peptidomimetics interaction using NMR and computational studies

Cadherins are homophilic cell-cell adhesion molecules whose aberrant expression has often been shown to correlate with different stages of tumor progression. In this work, we investigate the interaction of two peptidomimetic ligands with the extracellular portion of human E-cadherin using a combination of NMR and computational techniques. Both ligands have been previously developed as mimics of the tetrapeptide sequence Asp1-Trp2-Val3-Ile4 of the cadherin adhesion arm, and have been shown to inhibit E-cadherin-mediated adhesion in epithelial ovarian cancer cells with millimolar potency. To sample a set of possible interactions of these ligands with the E-cadherin extracellular portion, STD-NMR experiments in the presence of two slightly different constructs, the wild type E-cadherin-EC1-EC2 fragment and the truncated E-cadherin-(Val3)-EC1-EC2 fragment, were carried out at three temperatures. Depending on the protein construct, a different binding epitope of the ligand and also a different temperature effect on STD signals were observed, both suggesting an involvement of the Asp1-Trp2 protein sequence among all the possible binding events. To interpret the experimental results at the atomic level and to probe the role of the cadherin adhesion arm in the dynamic interaction with the peptidomimetic ligand, a computational protocol based on docking calculations and molecular dynamics simulations was applied. In agreement with NMR data, the simulations at different temperatures unveil high variability/dynamism in ligand-cadherin binding, thus explaining the differences in ligand binding epitopes. In particular, the modulation of the signals seems to be dependent on the protein flexibility, especially at the level of the adhesive arm, which appears to participate in the interaction with the ligand. Overall, these results will help the design of novel cadherin inhibitors that might prevent the swap dimer formation by targeting both the Trp2 binding pocket and the adhesive arm residues. Author summary Classical cadherins are the main adhesive proteins at the intercellular junctions and play an essential role in tissue morphogenesis and homeostasis. A large number of studies have shown that cadherin aberrant expression and/or dysregulation often correlate with pathological processes, such as tumor development and progression. Notwithstanding the emerging role played by cadherins in a number of solid tumors, the rational design of small inhibitors targeting these proteins is still in its infancy, likely due to the challenges posed by the development of small drug-like molecules that modulate protein-protein interactions and to the structural complexity of the various cadherin dimerization interfaces that constantly form and disappear as the protein moves along its highly dynamic and reversible homo-dimerization trajectory. In this work, we study the interaction of two small molecules with the extracellular portion of human E-cadherin using a combination of spectroscopic and computational techniques. The availability of molecules interfering in the cadherin homophilic interactions could provide a useful tool for the investigation of cadherin function in tumors, and potentially pave the way to the development of novel alternative diagnostic and therapeutic interventions in cadherin-expressing solid tumors

Evolutionary relationships among barley and <i>Arabidopsis</i> core circadian clock and clock-associated genes

The circadian clock regulates a multitude of plant developmental and metabolic processes. In crop species, it contributes significantly to plant performance and productivity and to the adaptation and geographical range over which crops can be grown. To understand the clock in barley and how it relates to the components in the Arabidopsis thaliana clock, we have performed a systematic analysis of core circadian clock and clock-associated genes in barley, Arabidopsis and another eight species including tomato, potato, a range of monocotyledonous species and the moss, Physcomitrella patens. We have identified orthologues and paralogues of Arabidopsis genes which are conserved in all species, monocot/dicot differences, species-specific differences and variation in gene copy number (e.g. gene duplications among the various species). We propose that the common ancestor of barley and Arabidopsis had two-thirds of the key clock components identified in Arabidopsis prior to the separation of the monocot/dicot groups. After this separation, multiple independent gene duplication events took place in both monocot and dicot ancestors. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00239-015-9665-0) contains supplementary material, which is available to authorized users