Graph theory approach to exceptional points in wave scattering

In this paper, we use graph theory to solve wave scattering problems in the discrete dipole approximation. As a key result of this work, in the presence of active scatterers, we show how one can find arbitrary large-order zero eigenvalue exceptional points (EPs) in parameter space by solving a set of non-linear equations. We interpret these equations in a graph theory picture as vanishing sums of scattering events. We also show how the total field of the system responds to parameter perturbations at the EP. Finally, we investigate the sensitivity of the power output to imaginary perturbation in the design frequency. This perturbation can be employed to trade sensitivity for a different dissipation balance of the system.Comment: 15 pages, 11 figure

Pattern characterization of genes involved in non-specific immune response in Staphylococcus aureus isolates from intramammary infections

Staphylococcus aureus isolated from mammary gland are characterized by different genetic patterns. Ninety four isolates from 33 dairy herds were analyzed by the means of amicroarray to investigate S. aureus virulence patterns and the distribution of genes believed to be involved in immune evasion. None of the 94 isolates considered were MRSA. However, 50% of the isolates belonged to complexes related to MRSA and to human diseases, while only about 25% of them can be considered as exclusively of bovine origin. The distribution of clonal complexes and the different gene patterns observed confirmed the presence of an influence of geographical localization. The assessment of the influence of genes related to immune evasion on quarter milk cell count showed as four of them showed to be significantly associated to an increase quarter milk SCC. These genes could be potential target for developing new vaccines against S.aureus

Robustness evaluation of different controllers in the presence of flow rate variations

This paper proposes a direct approach to evaluate achievable robustness to flow rate variations of different controllers (PID and advanced algorithms), for typical process dynamics (First Order Plus Time Delay with different time delay/lag ratio), able to represent very common heat exchange equipment. Starting from comparable nominal performance, the effect of flow rate variations on process parameters and consequently on achievable performance is analyzed in simulation up to the onset of marginal stability conditions. Flow rate variations act as “structured” uncertainty on parameters and the proposed procedure is able to indicate maximum allowable variations in a more realistic and efficient way, avoiding the conservatism implicit in most of analytical design techniques available in the literature. The proposed technique evaluates in a straightforward way the Maximum Allowed Changes (MAC) in flow rate. As inverse proportionality between flow rate and process parameters is present, also the efficacy of adopting equal percentage (EP) valves, which allow a local compensation of process gain nonlinearity, is investigated

Parental species and hybrid descendants of Bacillus (Insecta Phasmatodea) show different patterns of highly amplified, colocalized ribosomal and telomeric sequences

We investigated by dual-color fluorescence in situ hybridization (FISH) with 28S ribosomal and (TTAGG)n telomeric probes all species of the circum-Mediterranean genus Bacillus encompassing bisexual and parthenogenetic taxa, namely the three parental species (B. grandii, B. atticus, B. rossius) and the two derived hybrids (B. whitei, B. lynceorum). Specimens were collected in Italian mainland, Sardinia and Sicily. In all species the presence of colocalized, highly amplified ribosomal and telomeric sequences was demonstrated by the double labelling of the cytological satellites. These satellites varied in size, number and location both among and within species. In B. grandii and B. atticus a maximum of two FISH-labeled locations were observed, whereas in B. rossius and in the two hybrids up to 11 different positions were recorded. Moreover, our investigations showed a significant occurrence of chromosome breakages and rearrangements. The overall meaning of the ribosomal and telomeric sequence colocalization as well as the Nucleolar Organizer Region mobility and activity are discussed in both the ancestors and their hybrid descendants. It is noteworthy that the same trait has been shown in seven additional phasmid species belonging to distantly related genera. This trait could be a shared ancestral character in phasmids

An automatic system for modeling and controlling color quality of dyed leathers in tanneries

This paper presents an automatic system for modeling and controlling color quality of dyed leathers of an Italian tannery. The proposed software is implemented within the IT company system, and is fully integrated with the machineries of the finishing line, that is, a spraying cabin with a robotic carousel, and an electronic tintometer system. Suitable experimental tests according to the Design of Experiments (DoE) are firstly defined, executed and analyzed for a series of color tones of interest. In order to derive and validate a set of colorimetric models able to evaluate and predict the color rendering of painted leathers, a set of recipes of basic dye pigments and data of light reflection measured by a multispectral camera are used. Principal Component Analysis is applied for dimensionality reduction, and linear least squares regression is employed to identify these data-driven models, which are then used for color control purpose. A color correction feedback strategy is indeed developed in order to converge towards the various target formulations. The control algorithm aims at reaching the multispectral reading values of the reference, that is, the first sample of unknown color recipe starting from the most similar archive base and appropriately updating the recipe of pigments, by using the measurement of leather samples prepared from time to time by the finishing line machineries. A set of company data are used to successfully validate the identified colorimetric models and the proposed color correction strategy

Sequence analysis of a microsatellite and its flanking regions in intraspecific hybrids of grapevine (Vitis vinifera L.)

Microsatellite (MS) VVMD21 (BOWERS et al. 1999) was taken as a model to explore the molecular basis of polymorphism in a panel of 6 grapevine accessions (Vitis vinifera L.), consisting of Sangiovese and Cabernet Sauvignon and 4 F1 plants derived from crossing both varieties. The 12 alleles of both parents and the progeny were cloned and sequenced. The microsatellite repeat (AG)n>6 was found in each sequence, together with a poly-T rich region that showed irregularity. Furthermore, single nucleotide deletion or exchange (point mutations) were found in the microsatellite flanking regions

Numerical investigation of the mixing of highly viscous liquids with Cowles impellers

This work is aimed at investigating the mixing process of highly viscous paints, used to colour leathers in the tanning industry, through Computational Fluid Dynamics (CFD). In particular, a mixing tank is fed with a master liquid and different liquid pigments and then stirred by Cowles impellers in order to obtain a paint of a uniform colour. The typical dynamic viscosity of the liquids in this process is μ ~ O(0.1-10) Pa·s, while the Cowles rotational speed is usually very high, i.e. 3000-5000 rpm. The numerical model is based on the solution of the unsteady Reynolds-Averaged Navier–Stokes (RANS) equations for continuity, momentum and species mass fractions, the latter being used to describe the different components. The impeller motion is modelled through the Sliding Deforming Mesh (SDM) approach, using rotating (unstructured) meshes in the impeller region and a static (structured) mesh in the remainder of the tank. The master liquid and coloured pigments are assumed to stratify within the tank at initial time and the steady rotational speed is then imposed abruptly to the impellers. The level of homogeneity in the stirred tank is evaluated through the analysis of component concentration fields over time. In particular, such local concentrations can be used to determine the mixture colour in different regions of the tank, and hence predict the degree of homogeneity at different times; this is accomplished by defining a proper homogeneity indicator based on the spatial variance of the estimated colour. The proposed numerical model provides an efficient method to investigate the colour of the mixture and to evaluate an appropriate mixing time. The methodology gives also important indications for the tank design, especially useful in the case of non-conventional impellers, high rotation rates and viscous fluids

Islands as Time Capsules for Genetic Diversity Conservation: The Case of the Giglio Island Mouflon

The use of multidisciplinary approaches of investigation including biological, biogeographical, historical, morphological, and genetic analysis, can be useful in identifying and preserving biodiversity. The present study focuses on the characterisation and conservation of a mouflon population (Ovis gmelini musimon) from the Mediterranean island of Giglio. Here we provide the first molecular data on the Giglio population and compare it with mouflons from Sardinia, Elba, and Corsica using both nuclear and mitochondrial markers. Our results suggest that the Giglio mouflon harbours genetic variability likely of Sardinian origin but not represented in the current Sardinian mouflon diversity. Although not presenting the typical characteristics of an invasive alien species, the Giglio mouflon is being subjected to eradication through culling or trapping and surgical sterilization. The molecular evidence we report highlights that such actions are causing the irremediable loss of ancestral genetic variants of the genus Ovis. Finally, we highlight how a multidisciplinary approach is necessary to aid the conservation and management of the anthropochorous populations of Mediterranean mammals

Entanglement distance for arbitrary M -qudit hybrid systems

This is the final version. Available from the American Physical Society via the DOI in this recordThe achievement of quantum supremacy boosted the need for a robust medium of quantum information. In this task, higher-dimensional qudits show remarkable noise tolerance and enhanced security for quantum key distribution applications. However, to exploit the advantages of such states, we need a thorough characterisation of their entanglement. Here, we propose a measure of entanglement which can be computed either for pure and mixed states of a $M$-qudit hybrid system. The entanglement measure is based on a distance deriving from an adapted application of the Fubini-Study metric. This measure is invariant under local unitary transformations and has an explicit computable expression that we derive. In the specific case of $M$-qubit systems, the measure assumes the physical interpretation of an obstacle to the minimum distance between infinitesimally close states. Finally, we quantify the robustness of entanglement of a state through the eigenvalues analysis of the metric tensor associated with it.QuantERA ERA-NET Co-fundEngineering and Physical Sciences Research Council (EPSRC

Pathways of 4-hydroxy-2-nonenal detoxification in a human astrocytoma cell line

One of the consequences of the increased level of oxidative stress that often characterizes the cancer cell environment is the abnormal generation of lipid peroxidation products, above all 4-hydroxynonenal. The contribution of this aldehyde to the pathogenesis of several diseases is well known. In this study, we characterized the ADF astrocytoma cell line both in terms of its pattern of enzymatic activities devoted to 4-hydroxynonenal removal and its resistance to oxidative stress induced by exposure to hydrogen peroxide. A comparison with lens cell lines, which, due to the ocular function, are normally exposed to oxidative conditions is reported. Our results show that, overall, ADF cells counteract oxidative stress conditions better than normal cells, thus confirming the redox adaptation demonstrated for several cancer cells. In addition, the markedly high level of NADP+-dependent dehydrogenase activity acting on the glutahionyl-hydroxynonanal adduct detected in ADF cells may promote, at the same time, the detoxification and recovery of cell-reducing power in these cells