Load distribution in small world networks

In this paper we introduce a new model of data packet transport, based on a stochastic approach with the aim of characterizing the load distribution on complex networks. Moreover we analyze the load standard deviation as an index of uniformity of the distribution of packets within the network, to characterize the effects of the network topology. We measure such index on the model proposed by Watts and Strogatz as the redirection probability is increased. We find that the uniformity of the load spread is maximized in the intermediate region, at which the small world effect is observed and both global and local efficiency are high. Moreover we analyze the relationship between load centrality and degree centrality as an approximate measure of the load at the edges. Analogous results are obtained for the load variance computed at the edges as well as at the vertices.Comment: 6 pages, 5 figures. Included in conference proceedings International Conference PhysCon 2005 August 24-26, 2005, Saint Petersburg, RUSSI

Sparse bayesian imaging of solar flares

We consider imaging of solar flares from NASA Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) data as a parametric imaging problem, where flares are represented as a finite collection of geometric shapes. We set up a Bayesian model in which the number of objects forming the image is a priori unknown, as well as their shapes. We use a sequential Monte Carlo algorithm to explore the corresponding posterior distribution. We apply the method to synthetic and experimental data, largely known in the RHESSI community. The method reconstructs improved images of solar flares, with the additional advantage of providing uncertainty quantification of the estimated parameters

Rational control of the activity of a Cu2+-dependent DNAzyme by re-engineering purely entropic intrinsically disordered domains

The function and activity of many proteins is finely controlled by the modulation of the entropic contribution of intrinsically disordered domains that are not directly involved in any recognition event. Inspired by this mechanism, we demonstrate here that we could finely regulate the catalytic activity of a model DNAzyme (i.e., a synthetic DNA sequence with enzyme-like properties) by rationally introducing intrinsically disordered nucleic acid portions in its original sequence. More specifically, we have re-engineered here the well-characterized Cu2+-dependent DNAzyme that catalyzes a self-cleavage reaction by introducing a poly(T) linker domain in its sequence. The linker is not directly involved in the recognition event and connects the two domains that fold to form the catalytic core. We demonstrate that the enzyme-like activity of this re-engineered DNAzyme can be modulated in a predictable and fine way by changing the length, and thus entropy, of such a linker domain. Given these attributes, the rational design of intrinsically disordered domains could expand the available toolbox to achieve a control of the activity of DNAzymes and, in analogy, ribozymes through a purely entropic contribution

Interdisciplinary full digital restorative treatment of a young patient with severe open bite and amelogenesis imperfecta: a case report.

Background Amelogenesis Imperfecta (AI) is a syndromic entity comprising several clinical conditions, mostly genetic- based, affecting quality and quantity of enamel. The use of digital tools can be advantageous to enhance communication between the dental team and patients. Moreover, a full digital approach would allow to check each single clinical step according to the treatment plan with a backward approach. The aim of this case report is to describe a multidisciplinary treatment program of a young patient with severe open bite and amelogenesis imperfecta, whose restorative rehabilitation was planned in a full-digital workflow, from the initial communication phase up to the final prosthodontic rehabilitation. Case report An 8-year old female patient was diagnosed with a Class II division 1 malocclusion, severe open bite and AI. The treatment plan included 3 phases: the elimination of the tongue interposition habit and the anterior open bite, the orthodontic correction of dental deviation and leveling of both dental arches and a prosthetic rehabilitation. The extraction of the four first molars corrected the canine and molar Angle Class II relationships, deviation of the midline and repositioning of the maxillary incisors on the sagittal plane. Feldspathic ceramics was used in anterior sites to enhance the esthetic outcome. CAD/CAM hybrid ceramo-polymeric restorative material (PICN) was chosen for posterior regions. Conclusion The outcomes of the present case report proved that the planned objectives were satisfactorily obtained thanks to proper treatment planning, full digital workflow and the patient’s optimal compliance with the extraoral device

Components of Purity to Describe the Polarimetric State of a 3-D Field Within the Reverberating Chamber

Reverberating chambers (RCs) are electrically large microwave enclosures in which a random electromagnetic 3-D, i.e., nonplanar, field is generated. To characterize such 3-D fields, a proper polarimetric decomposition is requested. In this article, a new set of parameters, namely the components of purity (CP), first proposed to the electromagnetic compatibility community, is presented. The CP parameters, which stem for the so-called trivial decomposition, are able to classify any 3-D polarimetric field into two states: regular and nonregular. Such characterization is of practical relevance, e.g., for RC isotropy testing

Precision Measurement of the Newtonian Gravitational Constant Using Cold Atoms

About 300 experiments have tried to determine the value of the Newtonian gravitational constant, G, so far, but large discrepancies in the results have made it impossible to know its value precisely. The weakness of the gravitational interaction and the impossibility of shielding the effects of gravity make it very difficult to measure G while keeping systematic effects under control. Most previous experiments performed were based on the torsion pendulum or torsion balance scheme as in the experiment by Cavendish in 1798, and in all cases macroscopic masses were used. Here we report the precise determination of G using laser-cooled atoms and quantum interferometry. We obtain the value G=6.67191(99) x 10^(-11) m^3 kg^(-1) s^(-2) with a relative uncertainty of 150 parts per million (the combined standard uncertainty is given in parentheses). Our value differs by 1.5 combined standard deviations from the current recommended value of the Committee on Data for Science and Technology. A conceptually different experiment such as ours helps to identify the systematic errors that have proved elusive in previous experiments, thus improving the confidence in the value of G. There is no definitive relationship between G and the other fundamental constants, and there is no theoretical prediction for its value, against which to test experimental results. Improving the precision with which we know G has not only a pure metrological interest, but is also important because of the key role that G has in theories of gravitation, cosmology, particle physics and astrophysics and in geophysical models.Comment: 3 figures, 1 tabl

AIF-1 gene does not confer susceptibility to Behçet's disease: Analysis of extended haplotypes in Sardinian population

Background BehcEet's disease (BD) is a polygenic immune-mediated disorder characterized by a close association with the HLA-B∗51 allele. The HLA region has a strong linkage disequilibrium (LD) and carries several genetic variants (e.g. MIC-A, TNF-α genes) identified as associated to BD because of their LD with HLA-B∗51. In fact, the HLA-B∗51 is inherited as part of extended HLA haplotypes which are well preserved in patients with BD. Sardinian population is highly differentiated from other Mediterranean populations because of a distinctive genetic structure with very highly preserved HLA haplotypes. Patients and methods In order to identify other genes of susceptibility to BD within the HLA region we investigated the distribution of human Allograft Inflammatory Factor-1 (AIF-1) gene variants among BD patients and healthy controls from Sardinia. Six (rs2736182; rs2259571; rs2269475; rs2857597; rs13195276; rs4711274) AIF-1 single nucleotide polymorphisms (SNPs) and related extended haplotypes have been investigated as well as their LD within the HLA region and with HLA-B∗51. Overall, 64 BD patients, 43 HLA-B∗51 positive healthy controls (HC) and 70 random HC were enrolled in the study. Results HLA-B∗51 was the only allele with significantly higher frequency (pc = 0.0021) in BD patients (40.6%) than in HC (9.8%). The rs2259571TAIF-1 variant had a significantly reduced phenotypic, but not allelic frequency in BD patients (72.1%; pc = 0.014) compared to healthy population (91.3%). That was likely due to the LD between HLA-B∗51 and rs2259571G(pc= 9E-5), even though the rs2259571Gdistribution did not significantly differ between BD patients and HC. Conclusion No significant difference in distribution of AIF-1 SNPs haplotypes was observed between BD patients and HC and between HLA-B∗51 positive BD patients and HLA-B∗51 positive HC. Taken together, these results suggest that AIF-1 gene is not associated with susceptibility to BD in Sardinia