Use of urinary gamma-glutamyl transferase (GGT) to monitor the pattern of proteinuria in dogs with leishmaniasis treated with N-methylglucamine antimoniate

The aim of this study was to assess if the coupled analysis of the urinary protein to creatinine (UPC) ratio and of the GGT/UC ratio (the ratio between urinary gamma-glutamyl transferase activity and urinary creatinine) may be used in treated leishmaniotic dogs to differentiate dogs with transient impairment of tubular function from dogs with persistent tubular damage. To this aim, 40 urine from 10 proteinuric and leishmaniotic dogs that at the first visit had high GGT/UC ratio, consistent with tubular damage, were collected and analyzed before treatments and 2, 4 and 6 weeks after treatment with N-methylglucamine antimoniate and allopurinol. Compared with pre-treatment values, at the end of the study period the UPC ratio decreased only in 5/10 dogs, which, however, were still proteinuric or borderline proteinuric. Conversely, the GGT/CU ratio decreased in 8/10 dogs and in 3 of them the values at the end of the study period were below the threshold consistent with tubular proteinuria. The GGT/UC values at 6 weeks was significantly lower than before treatment. However, transient increases were frequent for both the analytes. These results indicate that in most of the dogs that remain proteinuric after treatment, likely due to the persistent glomerular damage, the GGT/UC ratio tends to normalize. This suggests that in these dogs tubular proteinuria at admission depends on functional impairment of tubular cells likely due to the overflow of proteins from damaged glomeruli. However, tubular proteinuria occasionally persists, suggesting that tubulointerstitial damages persist even in dogs responsive to treatments

Development of a Numerical Approach for the CFD Simulation of a Gear Pump under Actual Operating Conditions

The geometric complexity and high-pressure gradients that characterize the design of the flow field of gear pumps make it very difficult to obtain an accurate CFD simulation of the component. Usually, assumptions are made both in terms of geometrical features and physics being included in the analysis. The contact between the teeth, which is a key factor for the correct functioning of these pumps, represents a critical challenge in 3D CFD simulations, mainly due to the intrinsic limits of the dynamic meshing techniques that can hardly effectively manage a zero or close to zero gap point forming during gear rotation. The geometric complexity and high-pressure gradients that characterize the gear pump flow field make a CFD analysis quite difficult, and the contact between the gear teeth is usually avoided, thus being an extremely important feature. In this paper, a gear pump composed of inlet and outlet pipes was considered, and the contact between the gear's teeth was modeled in two different ways, one where it is effectively implemented and one where it is avoided using distancing and a proper casing modification. Herein, a new methodology is proposed for the application of the dynamic mesh method in the Simcenter STAR-CCM+ environment using an adaptive remeshing technique. The proposed methodology is compared with the alternative overset meshing method available in the software. The new meshing method is implemented using a user-routing that reproduces the real geometry of the gears while rotating during the pump operation, with teeth contact included. The routine is optimized in order to limit the additional computation and time needed for the remeshing process. The results that can be obtained using the two meshing approaches for the gear pump are compared in terms of computational effort and the accuracy of the results. The two methods showed opposite results in almost all the reported results, with the overset being more precise in the radial pressure evaluation and the dynamic being more reliable in the cavitation/aeration extension cloud

A MACHINE LEARNING APPROACH TO MULTISPECTRAL SATELLITE DERIVED BATHYMETRY

Abstract. Bathymetry in coastal environment plays a key role in understanding erosion dynamics and evolution along coasts. In the presented investigation depth along the shore-line was estimated using different multispectral satellite data. Training and validation data derived from a traditional bathymetric survey developed along transects in Cesenatico; measured data were collected with a single-beam sonar returning centimetric precision. To limit spatial auto-correlation training and validation dataset were built choosing alternatively one transect as training and another as validation. Each set was composed by a total of ~6000 points. To estimate water depth two methods were tested, Support Vector Machine (SVM) and Random Forest (RF). The RF method provided the higher accuracy with a root mean square error value of 0.228 m and mean absolute error of 0.158 m, against values of 0.409 and 0.226 respectively for SVM. Results show that application of machine learning methods to predict depth near shore can provide interesting results that can have practical applications

A Computation Fluid Dynamics Methodology for the Analysis of the Slipper-Swash Plate Dynamic Interaction in Axial Piston Pumps

This paper proposes a CFD methodology for the simulation of the slipper's dynamics of a swash-plate axial piston unit under actual operating conditions. The study considers a typical slipper design, including a vented groove at the swash-plate interface. The dynamic fluid-body interaction (DFBI) model is exploited to find the instantaneous position of the slipper, while the morphing approach is adopted to cope with the corresponding mesh distortion. A modular approach is adopted to ensure high-quality mesh on the entire slipper surface and sliding interfaces provide the fluid dynamic connection between neighboring regions. The external forces acting on the slipper are included by means of user-defined lookup tables with the simulation estimating the lift force induced by fluid compression. Moreover, the force produced by the metal-to-metal contact between the slipper and the swash plate is modeled through a specific tool of the software. The pressure signal over an entire revolution of the pump is taken as an input of the simulation and a variable time step is used to manage the high-pressure gradients occurring in the regions of inner and outer dead points of the piston. The weakly compressible characteristic of the fluid is considered by a specific pressure-dependent density approach, and the two-equation eddy-viscosity k-omega SST (shear stress transport) model is used to assess the turbulent behavior of the flow. Furthermore, the transitional model predicts the onset of transition, thus solving different equations depending on whether the flow enters a laminar or turbulent regime. In conclusion, the proposed methodology investigates the motion of the slipper in response to several external forces acting on the component. The numerical results are discussed in terms of variable clearance height, pressure distribution within the gap, and lift forces acting on the slipper under specific pump operations

On the Mechanical Energy Involved in the Catastrophic Rupture of Liquid Hydrogen Tanks

Hydrogen can play a central role in the energy transition thanks to its unique properties. However, its low density is one of the main drawbacks. The liquefaction process can drastically increase its density up to virtually 71 kg m-3 at atmospheric pressure and -253°C (NIST, 2019). The safety knowledge gap on physical explosions is still broad in the case of liquid hydrogen (LH2). For instance, it is unclear what are the consequences yields as well as the probabilities of a catastrophic rupture of an LH2 tank. A boiling liquid expanding vapour explosion (BLEVE) might arise after this top event. In this case, the expansion of the compressed gaseous phase is followed by the flashing of a fraction of the liquid. Moreover, combustion may occur for hydrogen since it is highly flammable. This complex phenomenon was not widely explored for LH2 yet. This study focused on the physical explosion by also considering the combustion process. Many integral models were adopted to estimate the mechanical energy developed by the explosion. The tank pressure prior to the rupture was considered below the critical one (1.298 MPa (NIST, 2019)). It was assumed that both liquid and gaseous phases are present inside the tank. The influences of the filling degree of the tank (liquid level) and the temperatures of the liquid and gaseous phases on the explosion energy were analysed. The results were compared with the ones of a previous study where similar models were employed to estimate the mechanical energy of an LH2 tank with different initial conditions (Ustolin et al., 2020a). In particular, the effect of the combustion process on the explosion energy and shock wave overpressure was not accounted for. The aim of this study is to conduct a comparison between different models and assess which are the most and the least conservative. The outcomes of this work provide critical suggestions on the consequence analysis of cryogenic liquefied gas vessels explosions

Blue Straggler Stars: The Spectacular Population in M80

Using HST-WFPC2 observations in two ultraviolet (UV) filters (F225W and F336W) of the central region of the high density Galactic Globular cluster (GGC) M80 we have identified 305 Blue Straggler Stars (BSS) which represents the largest and most concentrated population of BSS ever observed in a GGC. We also identify the largest, clean sample of evolved BSS yet found. The high stellar density alone cannot explain the BSS, and we suggest that in M80 we are witnessing a transient dynamical state, during which stellar interactions are delaying the core-collapse process leading to an exceptionally large population of collisional-BSS.Comment: 15 pages, 5 figures, Astrophysical Journal Letters, in pres

Assessment of susceptibility to European stone fruit yellows phytoplasma of new plum variety and five rootstock/plum variety combinations

Two separate experiments were carried out to assess the plum susceptibility to infection by European stone fruit yellows phytoplasmas during a five years period. Commercial varieties/cultivars and new selections grafted on Myrabolan 29C were evaluated in at least two plots of four plants each. Visual inspection and PCR/RFLP identification of phytoplasmas detected an increasing phytoplasma presence in both symptomatic and asymptomatic plants. Eight Japanese plum selections showed ESFY symptoms or pathogen presence in the 50% of the plants and nine selections showed ESFY infection in 20% of the plants. Only nine selections showed absence of both symptoms and pathogen. Although the European selections/cultivars were not symptomatic, plants belonging to six of these cultivars were positive for phytoplasma infection. The evaluation of cultivar/rootstock combinations indicate phytoplasma presence from the first year after plantation on. Two of the rootstocks seem to induce a delay in symptoms appearance and cultivar T.C. Sun resulted to be the most susceptible to the disease independently from the rootstock employed. Keywords: Japanese plum, European plum, European stone fruit yellows phytoplasmas, resistance, disease

Identification and GroEL gene characterization of green petal phytoplasma infecting strawberry in Italy

none5The presence of phytoplasmas in strawberry showing malformation of the fruits together with the typical green petals symptoms was detected in some North Western Italy cultivations. Nucleic acids extracted from these plants were used in nested-PCR assays with primers amplifying 16S rDNA and GroEL sequences specific for phytoplasmas. Bands of 1.2 kb were obtained in both cases after nested-PCR assays and RFLP analyses allowed to classify the detected phytoplasmas in the aster yellows subgroup 16SrI-C, the GroELI grouping confirm all the strains from strawberry to be identical to each other and to GroELI-VI group. This is the first multigene molecular identification of strawberry green petals phytoplasmas in Italy.openContaldo N.; J.F. Mejia; S. Paltrinieri; A. Calari; A. BertacciniContaldo N.; J.F. Mejia; S. Paltrinieri; A. Calari; A. Bertaccin

Comparison of protein carbonyl (Pco), paraoxonase-1 (pon1) and c-reactive protein (crp) as diagnostic and prognostic markers of septic inflammation in dogs

Reliable diagnostic and prognostic markers of sepsis are lacking, but essential in veterinary medicine. We aimed to assess the accuracy of C-Reactive Protein (CRP), protein carbonyls (PCO) and paraoxonase-1 (PON1) in differentiating dogs with sepsis from those with sterile inflammation and healthy ones, and predict the outcome in septic dogs. These analytes were retrospectively evaluated at admission in 92 dogs classified into healthy, septic and polytraumatized. Groups were compared using the Kruskal–Wallis test, followed by a Mann–Whitney U test to assess differences between survivors and non-survivors. Correlation between analytes was assessed using the Spearman’s test, and their discriminating power was assessed through a Receiver Operating Characteristic (ROC) curve. PON1 and CRP were, respectively, significantly lower and higher in dogs with sepsis compared with polytraumatized and clinically healthy dogs (p < 0.001 for both the analytes), and also in dogs with trauma compared with healthy dogs (p = 0.011 and p = 0.017, respectively). PCO were significantly increased in septic (p < 0.001) and polytraumatized (p < 0.005) as compared with healthy dogs. PON1 and CRP were, respectively, significantly lower and higher in dogs that died compared with survivors (p < 0.001 for both analytes). Ultimately, evaluation of CRP and PON1 at admission seems a reliable support to diagnose sepsis and predict outcomes