The looping probability of random heteropolymers helps to understand the scaling properties of biopolymers

Random heteropolymers are a minimal description of biopolymers and can provide a theoretical framework to the investigate the formation of loops in biophysical experiments. A two--state model provides a consistent and robust way to study the scaling properties of loop formation in polymers of the size of typical biological systems. Combining it with self--adjusting simulated--tempering simulations, we can calculate numerically the looping properties of several realizations of the random interactions within the chain. Differently from homopolymers, random heteropolymers display at different temperatures a continuous set of scaling exponents. The necessity of using self--averaging quantities makes finite--size effects dominant at low temperatures even for long polymers, shadowing the length--independent character of looping probability expected in analogy with homopolymeric globules. This could provide a simple explanation for the small scaling exponents found in experiments, for example in chromosome folding

Ab initio GW many-body effects in graphene

We present an {\it ab initio} many-body GW calculation of the self-energy, the quasiparticle band plot and the spectral functions in free-standing undoped graphene. With respect to other approaches, we numerically take into account the full ionic and electronic structure of real graphene and we introduce electron-electron interaction and correlation effects from first principles. Both non-hermitian and also dynamical components of the self-energy are fully taken into account. With respect to DFT-LDA, the Fermi velocity is substantially renormalized and raised by a 17%, in better agreement with magnetotransport experiments. Furthermore, close to the Dirac point the linear dispersion is modified by the presence of a kink, as observed in ARPES experiments. Our calculations show that the kink is due to low-energy $\pi \to \pi^*$ single-particle excitations and to the $\pi$ plasmon. Finally, the GW self-energy does not open the band gap.Comment: 5 pages, 4 figures, 1 tabl

Influence of seed coat color on germination rate and seedling development of Trifolium repens. Is physiological dormancy possible?

Trifolium repens L. (var. Regal Ladino) is among the most used species of Italian legumes as fodder for pastures, for direct consumption, or as mowing for stocks and then pastures. The seed integument of Trifolium repens L. has different colors ranging from light yellow to dark brown. In this work, the physiology of germination of light-colored, light intermediate, dark and dark intermediate seeds was studied to highlight any difference in the percentage of seed germination and seedling development. The results showed a lower germination rate and a noticeable reduction of the root length in dark seeds compared to light seeds. In this context, tests to exclude a physiological dormancy of dark seeds were performed. Light microscope and scanning electron microscope observation were conducted to detect substantial differences in the structure and thickness of the integument and in the quality of reserves. Biochemical investigations have evidenced that total polyphenols content is similar in all the seeds categories, while higher amount of total flavonoids was detected in dark seeds. Total Polyphenols and flavonoids content decreased during germination in all seed groups

introduction to the symposium a focus on ethics in international courts and tribunals

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ex pluribus unum on the form and shape of a common code of ethics in international litigation

In April 2019, member-states of UNCITRAL Working Group III requested the UNCITRAL Secretariat to undertake preparatory work for a Code of Conduct for Investor-State Dispute Settlement focusing on the implementation and enforceability of such a code. This groundbreaking development signals that, for the first time, a consensus exists that a code of ethics for Investor-State dispute settlement is desirable and needed. This contribution addresses three threshold questions that such preparatory work raises, namely: the preferred form of the code, the code's substantive reach, and the optimal process for bringing a code to fruition. As set out below, we urge that states adopt a mandatory common code of ethics for disputes involving states, and that arbitral institutions adopt this code as part of their rules for administering arbitration

Galois Correspondence and Fourier Analysis on Local Discrete Subfactors

Discrete subfactors include a particular class of infinite index subfactors and all finite index ones. A discrete subfactor is called local when it is braided and it fulfills a commutativity condition motivated by the study of inclusion of Quantum Field Theories in the algebraic Haag–Kastler setting. In Bischoff et al. (J Funct Anal 281(1):109004, 2021), we proved that every irreducible local discrete subfactor arises as the fixed point subfactor under the action of a canonical compact hypergroup. In this work, we prove a Galois correspondence between intermediate von Neumann algebras and closed subhypergroups, and we study the subfactor theoretical Fourier transform in this context. Along the way, we extend the main results concerning α-induction and σ-restriction for braided subfactors previously known in the finite index case

Weathering Effects on Engineering Geological Properties of Trachydacitic Volcanic Rocks from the Monte Amiata (Southern Tuscany, Italy)

Variability in lithology and weathering degree affects physical and mechanical properties of rocks. In this study, we investigated the relationships between weathering degree and engineering geological properties of trachydacitic volcanic rocks from Monte Amiata (central Italy) by coupling field and laboratory analyses. We collected in situ Schmidt hammer tests in the field. We evaluated weathering quantifying the percentage of secondary minerals through thermal analysis in the laboratory. We also determined dry density (rd), specific gravity of solids (Gs), porosity (n) and two-dimensional (2D) porosity as resulted from scanning electron microscopy investigations. The results of our study indicate a negative linear correlation between Schmidt hammer rebound values and secondary mineral percentage. This correlation provides a tool to quantitatively estimate the deterioration of rock uniaxial compressive strength (UCS) as weathering increases. Moreover, thermal analysis turned out to be a quantitative and reproducible method to evaluate weathering degree of magmatic rocks

Structural effects of anomalous current densities on manganese hexacyanoferrate for Li-ion batteries

A battery management system (BMS) plays a pivotal role in providing optimal performance of lithium-ion batteries (LIBs). However, the eventual malfunction of the BMS may lead to safety hazards or reduce the remaining useful life of LIBs. Manganese hexacyanoferrate (MnHCF) was employed as the positive electrode material in a Li-ion half-cell and subjected to five cycles at high current densities (10 A g$_{MnHCF}$$^{−1}$) and to discharge at 0.1 A g$_{MnHCF}$$^{−1}$, instead of classical charge/discharge cycling with initial positive polarization at 0.01 A g$_{MnHCF}$$^{−1}$, to simulate a current sensor malfunctioning and to evaluate the electrochemical and structural effects on MnHCF. The operando set of spectra at the Mn and Fe K-edges was further analyzed through multivariate curve resolution analysis with an alternating least squares algorithm (MCR–ALS) and extended X-ray absorption fine structure (EXAFS) spectroscopy to investigate the structural modifications arising during cycling after the applied electrochemical protocol. The coulombic efficiency in the first cycle was dramatically affected; however, the local structural environment around each photo absorber recovered during charging. The identification of an additional spectral contribution in the electrochemical process was achieved through MCR-ALS analysis, and the Mn-local asymmetry was thoroughly explored via EXAFS analysis

Toxicological assays with Vicia faba L. for monitoring bioremediation processes of soils contaminated by polycyclic aromatic hydrocarbons and total petroleum hydrocarbons

The ecotoxicological assays are used both in the assessment of the toxicity of various matrices and to estimate the effectiveness of the remediation of a matrix over time. Several organisms can be employed in eco-toxicological tests in the lab, or can be observed in their natural environment representing indicators of specific environmental conditions. Higher plants can be exploited as good indicators of the quality of different matrices and used both as a standard during remediation processes of contaminated soil but also in the evaluation of soil quality. In fact, the only chemical characterization of a polluted soil does not allow to predict the real toxicity of the matrix, that may depend on the original pollutants, on degradations intermediates, often unknown, and on the synergic actions of the different toxicants. The aim of this research was to evaluate the efficacy of the process abatement of the initial concentration, in a contaminated soil, of polycyclic aromatic hydrocarbons (PAHs, 6480 ppm) and of total petroleum hydrocarbons (TPHs, 18347 ppm) by means of a biopile in terms of reduction of the final matrix toxicity. For this reason soil samples at different time intervals from the beginning of treatment in biopile were collected and chemically characterized, for the monitoring and assessment of the possible phyto-genotoxic effects on the model system Vicia faba L. The biopile treatment determined the depletion of PAHs and TPHs below 10 and 100 ppm respectively. Biological parameters such as germination and root elongation were also evaluated as well as the possible genotoxic effects by means of cytological analysis of mitotic behaviour of root meristem, based on detection of chromosomal aberrations in mitotic cells, and of micronuclei formation, detectable in interphase cells. As additionally genotoxicity endpoint, cytohistochemical detection of in situ DNA fragmentation in root apices was achieved by TUNEL reaction, that allows to recognize both single and double-strand breaks at cellular and tissue level. Comparing the obtained results it was found that the phyto-genotoxic effect of contaminated soil was completely depleted after treatment in biopile and Vicia faba was found to be a good approach for monitoring the biodegradation processes and the toxicity of these solid matrices at the end of a bio-based decontamination approach. Keywords: genotoxicity, phytotoxicity, polycyclic aromatic hydrocarbons, total petroleum hydrocarbon