Denoising and enhancement of mammographic images under the assumption of heteroscedastic additive noise by an optimal subband thresholding

Mammographic images suffer from low contrast and signal dependent noise, and a very small size of tumoral signs is not easily detected, especially for an early diagnosis of breast cancer. In this context, many methods proposed in literature fail for lack of generality. In particular, too weak assumptions on the noise model, e.g., stationary normal additive noise, and an inaccurate choice of the wavelet family that is applied, can lead to an information loss, noise emphasizing, unacceptable enhancement results, or in turn an unwanted distortion of the original image aspect. In this paper, we consider an optimal wavelet thresholding, in the context of Discrete Dyadic Wavelet Transforms, by directly relating all the parameters involved in both denoising and contrast enhancement to signal dependent noise variance (estimated by a robust algorithm) and to the size of cancer signs. Moreover, by performing a reconstruction from a zero-approximation in conjunction with a Gaussian smoothing filter, we are able to extract the background and the foreground of the image separately, as to compute suitable contrast improvement indexes. The whole procedure will be tested on high resolution X-ray mammographic images and compared with other techniques. Anyway, the visual assessment of the results by an expert radiologist will be also considered as a subjective evaluation

Order-of-magnitude speedup for steady states and traveling waves via Stokes preconditioning in Channelflow and Openpipeflow

Steady states and traveling waves play a fundamental role in understanding hydrodynamic problems. Even when unstable, these states provide the bifurcation-theoretic explanation for the origin of the observed states. In turbulent wall-bounded shear flows, these states have been hypothesized to be saddle points organizing the trajectories within a chaotic attractor. These states must be computed with Newton's method or one of its generalizations, since time-integration cannot converge to unstable equilibria. The bottleneck is the solution of linear systems involving the Jacobian of the Navier-Stokes or Boussinesq equations. Originally such computations were carried out by constructing and directly inverting the Jacobian, but this is unfeasible for the matrices arising from three-dimensional hydrodynamic configurations in large domains. A popular method is to seek states that are invariant under numerical time integration. Surprisingly, equilibria may also be found by seeking flows that are invariant under a single very large Backwards-Euler Forwards-Euler timestep. We show that this method, called Stokes preconditioning, is 10 to 50 times faster at computing steady states in plane Couette flow and traveling waves in pipe flow. Moreover, it can be carried out using Channelflow (by Gibson) and Openpipeflow (by Willis) without any changes to these popular spectral codes. We explain the convergence rate as a function of the integration period and Reynolds number by computing the full spectra of the operators corresponding to the Jacobians of both methods.Comment: in Computational Modelling of Bifurcations and Instabilities in Fluid Dynamics, ed. Alexander Gelfgat (Springer, 2018

SAT0368 PREGNANCY IN WOMEN WITH SPONDYLOARTHRITIS: WHO ARE THE PATIENTS AT RISK OF DISEASE FLARE?

Background:Patients with Spondyloarthritis (SpA) can experience flares during pregnancy and postpartum even though the available data are limited and not conclusive.Objectives:To assess disease activity and treatment modification during pregnancy and postpartum in patients with SpA and to identify risk factors for disease flare.Methods:Data on SpA pregnancies prospectively-followed in a pregnancy clinic from 2010 to 2019 were retrospectively analysed. Disease activity was assessed during each trimester and postpartum using ASDAS-CRP or DAS28-CRP. Flare was defined as an increase of disease activity leading to treatment modification (introduction or increase ≥5mg/day of prednisone, introduction of cDMARD or bDMARD)1.Results:Data on 50 pregnancies in 46 patients were collected (mean age at conception 33±4.7 years; median disease duration: 60 months (IQR 24-132); 33 psoriatic arthritis, 6 axialSpA, 2 reactive arthritis, 2 IBD-related SpA; 6 undifferentiated SpA, 1 juvenile idiopathic arthritis). Six pregnancies ended in miscarriage, so they weren't considered for the analysis of flares during pregnancy (table 1). Fifteen out of 44 (34%) pregnancies had at least one flare during pregnancy (6, 7 and 4 during 1st, 2ndand 3rdtrimester respectively; 2 pregnancies had multiple flares). A higher rate of flare was observed in pregnancies of patients with axial involvement (p=0.01), on treatment with bDMARDs at preconceptional visit (p=0.03) and who stopped TNFi at positive pregnancy test (p=0.03). Peripheral involvement was associated with a lower rate of flares (p=0.02). Medications resumed during pregnancy were steroids (in 6 pregnancies), cDMARDs (2 sulfasalazine, 1 cyclosporine) and bDMARDs (4 certolizumab, 4 etanercept). During postpartum period flares were recorded in 46% of patients.Table 1.clinical features, medication and disease activity in pregnancies with flare vs without flareCLINICAL FEATURESFLARE (15)NO FLARE (29)pAxial involvement, n (%)11/15 (73)9/29 (31)0.01Peripheral arthritis, n (%)8/15 (53)26/29 (90)0.02Enthesitis, n (%)5/15 (33)14/29 (48)nsDactilitis, n (%)3/15 (20)8/29 (28)nsPsoriasis, n (%)6/15 (40)17/29 (59)nsIBD, n (%)2/15 (13)0nsUveitis, n(%)1/15 (7)3/29 (10)nsHLAB27 +7/11 (64)5/12 (42)nsMEDICATION HISTORYbDMARDs, n (%)11/15 (73)7/29 (24)0.003bDMARDs at preconception visit, n (%)8/15 (53)6/29 (21)0.04bDMARDs stopped at positive pregnancy test, n (%)7/15 (47)4/29 (14)0.03cDMARDs, n (%)12/15 (80)25/29 (86)nsDISEASE ACTIVITYACTIVE DISEASE* preconception visit, n(%)3/14 (21)4/23 (17)nsACTIVE DISEASE 1sttrimester, n(%)6/15 (40)1/29 (3)0.004ACTIVE DISEASE 2ndtrimester, n(%)8/15 (47)2/29 (7)0.001ACTIVE DISEASE 3rdtrimester, n(%)2/15 (13)1/29 (3)ns*DAS28-CRP>3.2 or ASDAS-CRP≥2.1Conclusion:In our cohort of prospectively-followed SpA pregnancies, 34% experienced a flare during pregnancy and 46% during postpartum. Flares occurred especially in those patients who discontinued TNFi early in pregnancy and with axial involvement. When resumed during pregnancy, TNFi was able to control the disease. At preconception counselling, the continuation of TNFi during pregnancy should be considered to ensure a better control of disease.References:[1]Fischer-Betz R et al.Arthritis Rheumatol. 2015; 67.Disclosure of Interests: :None declare

Nucleosynthesis Calculations for the Ejecta of Neutron Star Coalescences

We present the results of fully dynamical r-process network calculations for the ejecta of neutron star mergers (NSMs). The late stages of the inspiral and the final violent coalescence of a neutron star binary have been calculated in detail using a 3D hydrodynamics code (Newtonian gravity plus backreaction forces emerging from the emission of gravitational waves) and a realistic nuclear equation of state. The found trajectories for the ejecta serve as input for dynamical r-process calculations where all relevant nuclear reactions (including beta-decays depositing nuclear energy in the expanding material) are followed. We find that all the ejected material undergoes r-process. For an initial Ye close to 0.1 the abundance distributions reproduce very accurately the solar r-process pattern for nuclei with A above 130. For lighter nuclei strongly underabundant (as compared to solar) distributions are encountered. We show that this behaviour is consistent with the latest observations of very old, metal-poor stars, despite simplistic arguments that have recently been raised against the possibility of NSM as possible sources of Galactic r-process material.Comment: 5 pages, 2 figures, proceedings of Nuclei in the Cosmos 2000, to be published in Nucl. Phys. A; minor correctio

Acute cardiac injury after subarachnoid haemorrhage: two case reports

It is well known that cardiopulmonary complications are often associated to subarachnoid haemorrhage. For appropriate therapeutic managing it is very important to distinguish acute coronary syndrome from neurogenic myocardial injury, which is a reversible condition. Furthermore, because the hearts of brain dead patients may be utilized for therapeutic purpose, it has became of importance to rule out erroneous diagnosis of cardiac ischemia in order to avoid rejection of hearts potential suitable for transplantation

A 62 MeV proton beam for the treatment of ocular melanoma at Laboratori Nazionali del Sud-INFN (CATANIA)

At the Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud (INFN-LNS) in Catania, Italy, the first Italian protontherapy facility, named Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA) has been built in collaboration with the University of Catania. It is based on the use of the 62-MeV proton beam delivered by the K=800 Superconducting Cyclotron installed and working at INFN-LNS since 1995. The facility is mainly devoted to the treatment of ocular diseases like uveal melanoma. A beam treatment line in air has been assembled together with a dedicated positioning patient system. The facility has been in operation since the beginning of 2002 and 66 patients have been successfully treated up to now. The main features of CATANA together with the clinical and dosimetric features will be extensively described; particularly, the proton beam line, that has been entirely built at LNS, with all its elements, the experimental transversal and depth dose distributions of the 62-MeV proton beam obtained for a final collimator of 25-mm diameter and the experimental depth dose distributions of a modulated proton beam obtained for the same final collimator. Finally, the clinical results over 1 yr of treatments, describing the features of the treated diseases will be reported

Real-Time Online Monitoring of the Ion Range by Means of Prompt Secondary Radiations

International audiencePrompt secondary radiations such as gamma rays and protons can be used for ion-range monitoring during ion therapy either on an energy-slice basis or on a pencil-beam basis. We present a review of the ongoing activities in terms of detector developments, imaging, experimental and theoretical physics issues concerning the correlation between the physical dose and hadronic processe

Boffi (A): Managing Internationalization in Luxury Goods

The case examines in depth the internationalization process of a niche company in the luxury market. Its approach leverages the high quality standards of production, the Made in Italy reputation in this field, the selected and controlled network of retailers. While the industry Boffi belongs to is quite sensitive to differences among countries, Boffi does not provide any particular adaptation of models. However, each specific kitchen is designed according to the requirements of high-spending customers. This is a typical case of a SME that exports what is locally produced without a sophisticated assessment system of foreign markets attractiveness and profitability