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

Introducing database communication technologies for TED replication in multi-domain networks

In multi-domain transport networks, exchange of Traffic Engineering information is required to enable effective end-to-end service provisioning and restoration by efficiently utilizing network resources. So far, several solutions have been proposed by the communication community such as the Hierarchical Path Computation Element (H-PCE) architecture. Using the H-PCE architecture a parent PCE is responsible for inter-domain path computation, while a dedicated child PCE performs intra-domain path computation within each domain. However, this approach can introduce scalability concerns especially under dynamic traffic condition such as during restoration because all path computation procedures are coordinated by the parent PCE and may require the exchange of many control messages. This paper proposes a standard communication among database systems located at the child PCEs, to exchange and share YANG-based Traffic Engineering information in multi-domain networks. By exploiting currently available database technologies, scalable and predictable performance is demonstrated for both replication mechanisms among child PCEs and information retrieval from the stored databases. Thus, this proposal enables the sharing of intra-domain information at each cPCE that can be locally used, upon failure, to speed-up the recovery procedure

Anomalous Angular Dependence of the Dynamic Structure Factor near Bragg Reflections: Graphite

The electron energy-loss function of graphite is studied for momentum transfers q beyond the first Brillouin zone. We find that near Bragg reflections the spectra can change drastically for very small variations in q. The effect is investigated by means of first principle calculations in the random phase approximation and confirmed by inelastic x-ray scattering measurements of the dynamic structure factor S(q,\omega). We demonstrate that this effect is governed by crystal local field effects and the stacking of graphite. It is traced back to a strong coupling between excitations at small and large momentum transfers

Herd structure in the bovine Calvana breed

Farm structure is one of the principle components that influence profit, sustainability and survival of a herd, especially in endangered breeds. The sustainability of these herds is based on the capability to take advantage of specific niches of the market, of specific label or organic certification or "designation of geographical indications or origin for agricultural products"

Peripheral neurological disturbances, autonomic dysfunction, and antineuronal antibodies in adult celiac disease before and after a gluten-free diet

Thirty-two consecutive adult celiac disease (CD) patients (pts), complaining of peripheral neuropathy (12 pts), autonomic dysfunction (17 pts), or both (3 pts), were evaluated to assess the presence of neurological damage (by clinical neurological evaluation and electrophysiological study) and antineuronal antibodies and to assess the effect of a gluten-free diet (GFD) on the course of the neurological symptoms and on antineuronal antibodies. At entry, 12 of 32 (38%) pts showed signs and symptoms of neurological damage: 7 of 12 (58%), peripheral neurological damage; 3 of 12 (25%), autonomic dysfunction; and 2 (17%), both peripheral neurological damage and autonomic dysfunction. The overall TNS score was 105 at entry. Anti-GM1 antibodies were present in 5 of 12 (42%) pts: 3 showed peripheral neurological damage and 2 showed both peripheral neurological damage and autonomic dysfunction. One year after the GFD was started, histological lesions were still present in only 10 of 12 (83%) pts. TNS score was 99, 98, 98, and 101 at the 3rd, 6th, 9th, and 12th month after the GFD was started, so it did not improve throughout the follow-up. None of the pts showed disappearance of antineuronal antibodies throughout the follow-up. We conclude that adult CD patients may show neurological damage and presence of antineuronal antibodies. Unfortunately, these findings do not disappear with a GFD

Semiarid Grassland and Winter Cereals for Lamb Production in Northeast Patagonia, Argentina

In northeastern Patagonia where grain crops often led to harvest failure, low yields and a high drought risk, a lamb production system was established. On a 10 years old agriculture wheat cropping was interrupted in 1996, allowing re-vegetation through exclusion of grazing. Natural grassland recovered, prevailing the species Stipa tenuis, Piptochaetium napostaense, Stipa ambigua. Part of the plot was sown to wheat grass (Thinopyrum ponticum). In 1999, to improve sheep feeding, oat (Avena sativa) and barley (Hordeum vulgare) were sown for grazing during winter-spring season. In this system Corriedale sheep, Texel x australian Merino (TEMA) and Ile de France x Australian Merino (ILMA) crosses were tested. Fertility, prolificacy, lamb mortality and weaning were evaluated. No differences among genotypes (α= 0.05) were found. Weaned lamb weight per ewe was significantly higher in cross ewes (p\u3c 0.0035), while production efficiency showed no significant differences among genotypes (α= 0.05), because of the higher body live weight of the crosses (p\u3c 0.0001). Yields of 16.4; 19.4 and 20.2kg lamb hectare–1 for Corriedale, TEMA and ILMA respectively were calculated, which represent an increase of 18 and 23 %. These differences could become economically significant in the production system under study

Insights into a Protein-Nanoparticle System by Paramagnetic Perturbation NMR Spectroscopy

BACKGROUND: The interaction between proteins and nanoparticles is a very relevant subject because of the potential applications in medicine and material science in general. Further interest derives from the amyloidogenic character of the considered protein, \u3b22-microglobulin (\u3b22m), which may be regarded as a paradigmatic system for possible therapeutic strategies. Previous evidence showed in fact that gold nanoparticles (AuNPs) are able to inhibit \u3b22m fibril formation in vitro. METHODS: NMR (Nuclear Magnetic Resonance) and ESR (Electron Spin Resonance) spectroscopy are employed to characterize the paramagnetic perturbation of the extrinsic nitroxide probe Tempol on \u3b22m in the absence and presence of AuNPs to determine the surface accessibility properties and the occurrence of chemical or conformational exchange, based on measurements conducted under magnetization equilibrium and non-equilibrium conditions. RESULTS: The nitroxide perturbation analysis successfully identifies the protein regions where protein-protein or protein-AuNPs interactions hinder accessibility or/and establish exchange contacts. These information give interesting clues to recognize the fibrillation interface of \u3b22m and hypothesize a mechanism for AuNPs fibrillogenesis inhibition. CONCLUSIONS: The presented approach can be advantageously applied to the characterization of the interface in protein-protein and protein-nanoparticles interactions

Study on the Effect of Preheating Temperatures on Melt Pool Stability in Inconel 718 Components Processed by Laser Powder Bed Fusion

Laser Powder Bed Fusion (L-PBF) is one of the most widespread, versatile, and promising metal Additive Manufacturing (AM) techniques. L-PBF allows for the manufacturing of geometrically complex parts with good surface characteristics. In this process, in order to minimize the heat loss in the first layers of printing, the building platform is preheated to a temperature ranging between 80 and 250 °C. This aspect turns out to be very critical, and further investigation is needed for situations where the part to be printed is only a few layers high, as is the case in sensor printing. This work aims to investigate the melt pool stability under a variation in the preheating temperatures. We investigate the distance from the building platform, considering the number of layers printed. This is where the melt pool reaches its stability in terms of depth and width. This aspect turns out to be of remarkable importance for ensuring the structural integrity of parts with a few layers of height that are processed through L-PBF, such as sensors, which are proliferating in different industries. Thus, two case studies were carried out on IN718 superalloys at 40 and 60 microns of layer thickness and a preheating temperature of 170 °C on the machine. The results obtained show that after 1.2 mm of distance from the building platform, the melt pool reached its stability in terms of width and depth dimensions and consequently for the melting regime