Aligned and Non-Aligned Double JPEG Detection Using Convolutional Neural Networks

Due to the wide diffusion of JPEG coding standard, the image forensic community has devoted significant attention to the development of double JPEG (DJPEG) compression detectors through the years. The ability of detecting whether an image has been compressed twice provides paramount information toward image authenticity assessment. Given the trend recently gained by convolutional neural networks (CNN) in many computer vision tasks, in this paper we propose to use CNNs for aligned and non-aligned double JPEG compression detection. In particular, we explore the capability of CNNs to capture DJPEG artifacts directly from images. Results show that the proposed CNN-based detectors achieve good performance even with small size images (i.e., 64x64), outperforming state-of-the-art solutions, especially in the non-aligned case. Besides, good results are also achieved in the commonly-recognized challenging case in which the first quality factor is larger than the second one.Comment: Submitted to Journal of Visual Communication and Image Representation (first submission: March 20, 2017; second submission: August 2, 2017

An Overview on the Generation and Detection of Synthetic and Manipulated Satellite Images

Due to the reduction of technological costs and the increase of satellites launches, satellite images are becoming more popular and easier to obtain. Besides serving benevolent purposes, satellite data can also be used for malicious reasons such as misinformation. As a matter of fact, satellite images can be easily manipulated relying on general image editing tools. Moreover, with the surge of Deep Neural Networks (DNNs) that can generate realistic synthetic imagery belonging to various domains, additional threats related to the diffusion of synthetically generated satellite images are emerging. In this paper, we review the State of the Art (SOTA) on the generation and manipulation of satellite images. In particular, we focus on both the generation of synthetic satellite imagery from scratch, and the semantic manipulation of satellite images by means of image-transfer technologies, including the transformation of images obtained from one type of sensor to another one. We also describe forensic detection techniques that have been researched so far to classify and detect synthetic image forgeries. While we focus mostly on forensic techniques explicitly tailored to the detection of AI-generated synthetic contents, we also review some methods designed for general splicing detection, which can in principle also be used to spot AI manipulate imagesComment: 25 pages, 17 figures, 5 tables, APSIPA 202

Structure-based discovery and in-parallel optimization of novelcompetitive inhibitors of thymidylate synthase

AbstractBackground:The substrate sites of enzymes are attractive targets for structurebased inhibitor design. Two difficulties hinder efforts to discover and elaborate new (nonsubstrate-like) inhibitors for these sites. First, novel inhibitors often bind at nonsubstrate sites. Second, a novel scaffold introduces chemistry that is frequently unfamiliar, making synthetic elaboration challenging.Results:In an effort to discover and elaborate a novel scaffold for a substrate site, we combined structure-based screening with in-parallel synthetic elaboration. These techniques were used to find new inhibitors that bound to the folate site of Lactobacillus casei thymidylate synthase (LcTS), an enzyme that is a potential target for proliferative diseases, and is highly studied. The available chemicals directory was screened, using a molecular-docking computer program, for molecules that complemented the three-dimensional structure of this site. Five high-ranking compounds were selected for testing. Activity and clocking studies led to a derivative of one of these, dansyltyrosine (Ki 65 μM. Using solid-phase in-parallel techniques 33 derivatives of this lead were synthesized and tested. These analogs are dissimilar to the substrate but bind competitively with it. The most active analog had a Ki of 1.3 μM. The tighter binding inhibitors were also the most specific for LcTS versus related enzymes.Conclusions:TS can recognize inhibitors that are dissimilar to, but that bind competitively with, the folate substrate. Combining structure-based discovery with in-parallel synthetic techniques allowed the rapid elaboration of this series of compounds. More automated versions of this approach can be envisaged

Zotarolimus-Eluting Versus Bare-Metal Stents in Uncertain Drug-Eluting Stent Candidates

BACKGROUND The use of drug-eluting stents (DES) in patients at high risk of bleeding or thrombosis has not been prospectively studied; limited data are available in patients who have a low restenosis risk. OBJECTIVES This study sought to compare a hydrophilic polymer-based, second-generation zotarolimus-eluting stent (ZES) with a unique drug fast-release profile versus bare-metal stents (BMS) under similar durations of dual-antiplatelet therapy (DAPT). METHODS We randomly assigned 1,606 patients with stable or unstable symptoms, and who on the basis of thrombotic bleeding or restenosis risk criteria, qualified as uncertain candidates for DES, to receive ZES or BMS. DAPT duration was on the basis of patient characteristics, rather than stent characteristics, and allowed for a personalized 1-month dual antiplatelet regimen. The primary endpoint was the risk of 1-year major adverse cardiovascular events (MACE), which included death, myocardial infarction (MI), or target vessel revascularization (TVR). RESULTS Median DAPT duration was 32 days (interquartile range [IQR]: 30 to 180 days) and did not differ between the groups. In the ZES group, 140 patients (17.5%) reached the primary endpoint, compared with 178 patients (22.1%) in the BMS group (hazard ratio: 0.76; 95% confidence interval: 0.61 to 0.95; p = 0.011) as a result of lower MI (2.9% vs. 8.1%; p < 0.001) and TVR rates (5.9% vs. 10.7%; p = 0.001) in the ZES group. Definite or probable stent thrombosis was also significantly reduced in ZES recipients (2.0% vs. 4.1%; p = 0.019). CONCLUSIONS Compared with BMS, DES implantation using a stent with a biocompatible polymer and fast drug-eluting characteristics, combined with an abbreviated, tailored DAPT regimen, resulted in a lower risk of 1-year MACE in uncertain candidates for DES implantation. (Zotarolimus-eluting Endeavor Sprint Stent in Uncertain DES Candidates [ZEUS] Study; NCT01385319) (C) 2015 by the American College of Cardiology Foundation

OUTCOMES OF ELDERLY PATIENTS WITH ST-ELEVATION OR NON-ST-ELEVATION ACUTE CORONARY SYNDROME UNDERGOING PERCUTANEOUS CORONARY INTERVENTION

Acute coronary syndromes have been classified according to the finding of ST-segment elevation on the presenting ECG, with different treatment strategies and practice guidelines. However, a comparative description of the clinical characteristics and outcomes of acute coronary syndrome elderly patients undergoing percutaneous coronary intervention during index admission has not been published so far

Cardiac magnetic resonance predictors of left ventricular remodelling following acute ST elevation myocardial infarction: The VavirimS study

Left ventricular (LV) remodelling (REM) ensuing after ST-elevation myocardial infarction (STEMI), has typically been studied by echocardiography, which has limitations, or cardiac magnetic resonance (CMR) in early phase that may overestimate infarct size (IS) due to tissue edema and stunning. This prospective, multicenter study investigated LV-REM performing CMR in the subacute phase, and 6&nbsp;months after STEMI

Strutture sismogenetiche in Appennino Centrale: potenziale sismico, analisi frattale e processi di crescita

The seismogenic structures of the axial zones of the Central Apennines Fault System have been recognized by means of detailed analyses of the capable faults exposed along a main deformation zone extending from Camerino to L'Aquila. The fault system also includes lower-rank faults, trending roughly NW-SE and N-S, showing normal and strike-slip components, respectively. Expected maximum magnitudes associated with normal and/or transtensional fault segments are lower than 6.0, whereas those expected from the activation of strike-slip faults may be high as 7.0. The results obtained from our study suggest that seismic activity in the area in mainly due to the development and evolution of a N-S trending strike-slip system composed of 3 main structures, each of which characterized by a surface fault pattern with specific fractal properties. The central structure of the system was interpreted to be the major seismogenic structure in the area and is thought to be responsible for the 1703 seismic sequence in Central Italy