921 research outputs found
Learning Graph Cut Energy Functions for Image Segmentation
In this paper we address the task of learning how to segment a particular class of objects, by means of a training set of images and their segmentations. In particular we propose a method to overcome the extremely high training time of a previously proposed solution to this problem, Kernelized Structural Support Vector Machines. We employ a one-class SVM working with joint kernels to robustly learn significant support vectors (representative image-mask pairs) and accordingly weight them to build a suitable energy function for the graph cut framework. We report results obtained on two public datasets and a comparison of training times on different training set sizes
Skin Surface Reconstruction and 3D Vessels Segmentation in Speckle Variance Optical Coherence Tomography
In this paper we present a method for in vivo surface reconstruction and 3D vessels segmentation from Speckle-Variance Optical Coherence Tomography imaging, applied to dermatology. This novel technology allows to capture motion underneath the skin surface revealing the presence of blood vessels. Standard OCT visualization techniques are inappropriate for this new source of information, that is crucial in early skin cancer diagnosis. We investigate 3D reconstruction techniques for better visualization of both the external and internal structure of skin lesions, as a tool to help clinicians in the task of qualitative tumor evaluation
Creation of a specific and separated pediatric intra-hospital pathway in primary level hospitals during the era of COVID-19
Every new pandemic forces us to start new specific behaviors both in the civil life and within the hospitals trying to contain the spreading of the infection and preserve the more fragile people. In this regard, at the debut of Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-CoV-2) pandemic, our Local Health Agency had drastically modified every clinical and organizational pathways in order to limit the diffusion of the infection as well as to maintain a good quality of care and preserve healthcare workers. We report how we have modified the usual pediatric intra-hospital pathways in our primary level hospital to avoid mixing children with suspected and non-suspected symptoms of SARS-CoV-2 infection. Before every hospitalization, regardless of symptoms, each child and him/her parent/caregiver are undergone to rapid antigenic and molecular swab to rule out a SARS-CoV-2 infection; hence, positive patients are transferred to Pediatric Unit of third level hospital equipped by a Pediatric COVID Intensive Unit. We think the healthcare behaviors described in this manuscript can help to reduce the intra-hospital spreading of SARS-CoV-2, although children seem to have a minimal role in the dissemination, but we cannot let down your guard. Simultaneously we observed that the overall children requiring inpatient pediatric evaluation and hospitalization have dramatically decreased from the beginning of pandemic
NAILFOLD VIDEOCAPILLAROSCOPY FEATURES OF PATIENTS WITH ANTISYNTHETASE SYNDROME
Background: Antisynthetase syndrome (ASSD) is an autoimmune disease characterized by the clinical triad arthritis, myositis, and interstitial lung disease (ILD). As in inflammatory myopathies, nailfold videocapillaroscopy (NVC) alterations have been sporadically described also in ASSD patients, but no elucidating data are available.
Objectives: To investigate the possible specific NVC features of ASSD patients.
Methods: Within the framework of a multicenter study, we retrospectively analyzed NVC images of ASSD patients, after excluding patients with overlap syndrome with systemic sclerosis. Two operators in a blind manner re-evaluated all patients with at least one image per finger. For each patient, we examined number of capillaries (mean number of capillaries per mm in the distal row), enlarged and giant capillaries, micro-hemorrhages, avascular areas, ramified capillaries, and the presence of a scleroderma (SSc)-like pattern, according to manfredi et al. Finally, we correlated NVC features with clinical and serological findings of ASSD patients.
Results: The NVC of 54 ASSD patients were analyzed (males/females 1/6.8, mean age 55.79, CI95% 51.9\u201359.9 years, mean disease duration 59.4, CI95% 27.9\u201390.9 months). Raynaud's phenomenon (RP) was recorded in 51.9% of patients, arthritis in 79.6%, myositis in 53.7%, and ILD in 92.6%. NVC alterations were observed in 53.7% of AASD patients. Nineteen patients (35.2%) showed a SSc-like pattern; the main features were disarrangement of hairpin and angiogenetic aspects (42.6%), avascular areas (38.9%), giant capillaries (27.6%), and microhemorrhages (20.4%). Finally, the mean number of capillaries was reduced (7.8\ub12/mm). No significant association was recorded between SSc-like pattern and the presence of arthritis, myositis, and ILD, nor with RP. Among other NVC features, angiogenesis was significantly associated to female gender (p=0.031), while microhemorrhages were inversely associated to the presence of arthritis (0.033). No association was observed between NVC features and autoantibodies profile. Of interest, in 58% of patients with ILD we observed at least a NVC alteration vs no patients without ILD (p=0.04). Finally, in patients with RP NVC alterations were recorded in 15/28 patients (53.6%) and a SSc-like pattern in 11/28 (39.3%), while only 57.9% of patients with SSc-like pattern had a clinically manifest Raynaud's phenomenon.
Conclusions: Despite preliminary, the present is the first study concerning NVC in AASD patients. Regardless of the presence of Raynaud's phenomenon, NVC alterations are frequently observed; in particular, a SSc-like pattern is recorded in more than 1/3 of patients. NVC should be performed in all ASSD patients at diagnosis regardless of the presence of RP in the patient history and during follow-up. ASSD should be always considered in the screening of RP. A prospective multicenter study has been planned to identify specific patterns and possible associations between NVC findings and clinical and serological features of ASSD
A complete system for garment segmentation and color classification
In this paper, we propose a general approach for automatic segmentation, color-based retrieval and classification of garments in fashion store databases, exploiting shape and color information. The garment segmentation is automatically initialized by learning geometric constraints and shape cues, then it is performed by modeling both skin and accessory colors with Gaussian Mixture Models. For color similarity retrieval and classification, to adapt the color description to the users’ perception and the company marketing directives, a color histogram with an optimized binning strategy, learned on the given color classes, is introduced and combined with HOG features for garment classification. Experiments validating the proposed strategy, and a free-to-use dataset publicly available for scientific purposes, are finally detailed
Non-invasive visual tools for diagnosis of oral cancer and dysplasia: a systematic review
Background: Gold standard for the diagnosis of oral dysplasia (OD) oral squamous cell carcinoma (OSCC) and
malignant lesions is the histological examination.
Several adjunctive diagnostic techniques have been proposed in order to increase the sensitivity (SE) and specificity (SP) of conventional oral examination and to improve the diagnostic first level accuracy.
The aim of this study is to perform a systematic review on non-invasive tools for diagnosis of OD and early
OSCC.
Material and Methods: Medline, Scopus, Web of Knowledge databases were searched, using as entry terms “oral
dysplasia AND diagnosis” / ”oral cancer AND diagnosis”. Data extracted from each study included number of
lesions evaluated, histopathological diagnosis, SE, SP, positive and negative predictive values (PPV and NPV),
diagnostic accuracy (DA) and the main conclusions.
Results: After title and abstract scanning of 11.080 records, we selected 35 articles for full text evaluation. Most
evaluated tools were autofluorescence (AF), chemiluminescence (CL), toluidine blu (TL) and chemiluminescence
associated with toluidine blue (CLTB).
Conclusions: There is a great inhomogeneity of the reported values and there is no significant evidence of superiority of one tool over the other. Further clinical trials with a higher level of evidence are necessary in order to
assess the real usefulness visual diagnostic tools
GOLD: Gaussians of Local Descriptors for Image Representation
The Bag of Words paradigm has been the baseline from which several successful image classification solutions were developed in the last decade. These represent images by quantizing local descriptors and summarizing their distribution. The quantization step introduces a dependency on the dataset, that even if in some contexts significantly boosts the performance, severely limits its generalization capabilities. Differently, in this paper, we propose to model the local features distribution with a multivariate Gaussian, without any quantization. The full rank covariance matrix, which lies on a Riemannian manifold, is projected on the tangent Euclidean space and concatenated to the mean vector. The resulting representation, a Gaussian of local descriptors (GOLD), allows to use the dot product to closely approximate a distance between distributions without the need for expensive kernel computations.
We describe an image by an improved spatial pyramid, which avoids boundary effects with soft assignment: local descriptors contribute to neighboring Gaussians, forming a weighted spatial pyramid of GOLD descriptors.
In addition, we extend the model leveraging dataset characteristics in a mixture of Gaussian formulation further improving the classification accuracy. To deal with large scale datasets and high dimensional feature spaces the Stochastic Gradient Descent solver is adopted. Experimental results on several publicly available datasets show that the proposed method obtains state-of-the-art performance
Personalized Medicine and Machine Learning: A Roadmap for the Future
In the last ten years, many advances have been made in the treatment and diagnosis of immune-mediated diseases [...]
Cryoglobulinemic vasculitis and skin ulcers. Our therapeutic strategy and review of the literature
Objective: Cryoglobulinemic vasculitis (CV) involving small- and medium-sized vessels is very frequently associated with hepatitis C virus and may be responsible for multiple organ involvement and skin ulcers (SU). Skin ulcers are often non-healing cutaneous lesions, possibly complicated by local infection and gangrene; they may severely affect the patients[U+05F3] quality of life and the overall prognosis. Therefore, the treatment of cryoglobulinemic SU is particularly challenging in the clinical practice.The present work evaluated the prevalence and correlations of cryoglobulinemic SU with other clinico-epidemiological features of CV; moreover, our long-term experience with the management strategies of these cutaneous lesions was compared with the world literature on this topic. Methods: The study included 126 CV patients (24 male and 102 female, aged 69 ± 11.2 SD years, disease duration 7 ± 6.9 SD years), followed at our Rheumatology Unit during the past decade. All patients were carefully evaluated regarding the entire cryoglobulinemic syndrome with particular concern for clinical characteristics and treatment of SU. Results: Among 126 CV patients, 36 individuals (29%) experienced at least one episode of SU, more commonly localized at the lower limbs. Patients with complicating SU showed significantly higher percentage of purpuric manifestations (p < 0.01) and liver (p < 0.001), peripheral nerve (p < 0.02), and/or thyroid involvement (p = 0.019).Therapeutic approach to SU included both systemic (immunosuppressors, corticosteroids, and/or plasma exchange) and local treatments. Local treatments consisted of sharp or surgical debridement as well as interactive dressing according to the condition of wound bed, perilesional skin, and the possible presence of infection, detected in 29 of 36 (81%) individuals in our Rheumatology unit. All patients underwent analgesic treatment for SU-related background pain as well as procedural pain, which was critical for an effective local SU management.The large majority of patients with SU healed at a variable time interval according to the severity of the single lesion; only five patients with very severe, non-healing SU needed amputation.The updated review of the literature revealed the presence of SU in around a quarter of CV patients. Among systemic treatments, the anti-CD20 monoclonal antibody rituximab represents one of the most effective and frequently employed therapies; however, the available data focusing on local therapeutic approach are generally limited to anecdotal observations. Conclusions: Overall, the treatment of cryoglobulinemic SU should be tailored to the single patient[U+05F3]s conditions using combined systemic and local treatments; lesional sharp debridement and interactive dressing as well as procedural pain management were decisive, particularly for more severe, non-healing cutaneous lesions
Stability of Oscillating Gaseous Masses in Massive Brans-Dicke Gravity
This paper explores the instability of gaseous masses for the radial
oscillations in post-Newtonian correction of massive Brans-Dicke gravity. For
this purpose, we derive linearized perturbed equation of motion through
Lagrangian radial perturbation which leads to the condition of marginal
stability. We discuss radius of instability of different polytropic structures
in terms of the Schwarzschild radius. It is concluded that our results provide
a wide range of difference with those in general relativity and Brans-Dicke
gravity.Comment: 31 pages, 11 figures, to appear in IJMP
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