Robust Machine Learning for Malware Detection over Time

The presence and persistence of Android malware is an on-going threat that plagues this information era, and machine learning technologies are now extensively used to deploy more effective detectors that can block the majority of these malicious programs. However, these algorithms have not been developed to pursue the natural evolution of malware, and their performances significantly degrade over time because of such concept-drift. Currently, state-of-the-art techniques only focus on detecting the presence of such drift, or they address it by relying on frequent updates of models. Hence, there is a lack of knowledge regarding the cause of the concept drift, and ad-hoc solutions that can counter the passing of time are still under-investigated. In this work, we commence to address these issues as we propose (i) a drift-analysis framework to identify which characteristics of data are causing the drift, and (ii) SVM-CB, a time-aware classifier that leverages the drift-analysis information to slow down the performance drop. We highlight the efficacy of our contribution by comparing its degradation over time with a state-of-the-art classifier, and we show that SVM-CB better withstand the distribution changes that naturally characterizes the malware domain. We conclude by discussing the limitations of our approach and how our contribution can be taken as a first step towards more time-resistant classifiers that not only tackle, but also understand the concept drift that affect data

ImageNet-Patch: A dataset for benchmarking machine learning robustness against adversarial patches

Adversarial patches are optimized contiguous pixel blocks in an input image that cause a machine-learning model to misclassify it. However, their optimization is computationally demanding, and requires careful hyperparameter tuning, potentially leading to suboptimal robustness evaluations. To overcome these issues, we propose ImageNet-Patch, a dataset to benchmark machine-learning models against adversarial patches. The dataset is built by first optimizing a set of adversarial patches against an ensemble of models, using a state-of-the-art attack that creates transferable patches. The corresponding patches are then randomly rotated and translated, and finally applied to the ImageNet data. We use ImageNet-Patch to benchmark the robustness of 127 models against patch attacks, and also validate the effectiveness of the given patches in the physical domain (i.e., by printing and applying them to real-world objects). We conclude by discussing how our dataset could be used as a benchmark for robustness, and how our methodology can be generalized to other domains. We open source our dataset and evaluation code at https://github.com/pralab/ImageNet-Patch

Resistencia química del Hormigón. XXVIII. Contribución al estudio del sistema Cemento P-550-ARI hidratado-disolución de sulfato de sodio

In this work, which is the following of the others, the performance of a portland cement of a high initial resistance (P-550-ARI) —with a calculated content (Bogue) of 39,2 - 25,7 - 9,9 - 12,0 and 6,9% of C3S - C2S - C3A - C4AF and CaSO4, respectively— is studied when it is submitted to the action of an sodium sulfate solution [2,1 g/l of Na2S04 1,42 g/l of SO4 (II) 1,48 X 10-2 moles/litre of SO4 (II)] running across the beds of granulated cement, made with this hydrated cement cured during 7 or 28 days, determining: a) The evolution of the content on ions Ca (II) and SO4 (II) on the taken diverse fractions of sodium sulfate solution which have run across those beds, so as this of the pH and of the conductivity, b) the variation in the amount of these ions that are forming the correspondents compounds, in the hydrated cement from the beds that have been submitted before and after to the action of the sodium sulfate solution, and c) the structural modifications undergone by the crystalline compounds of the hydrated cement from the beds submitted to the action of the sodium sulfate solution.En el presente trabajo, continuación de otros, se estudia el comportamiento de un cemento portland de alta resistencia inicial (P-550-ARI) con unos contenidos calculados (Bogue) de C3S, C2S, C3A, C3AF y CaS04 del 39,2 - 25,7 - 9,9 - 12,0 y 6,9%, respectivamente, cuando se somete a la acción de una disolución de sulfato de sodio [2,1 g/l de Na2SO4 1,42 g/l de SO4 (II) 1,48 X 10-2 moles/litro de SO4 (ll)], que atraviesa sendos lechos granulados fabricados con dicho cemento hidratado y curado durante 7 y 28 días, determinando: a) la evolución del contenido de iones Ca (II) y SO4 (II) en las diversas fracciones recogidas de la disolución de sulfato de sodio, que han atravesado los lechos de cemento, así como la del pH y de la conductividad, b) la variación de las cantidades de dichos iones, que se encuentran formando los compuestos correspondientes, en el cemento hidratado de los lechos antes y después de someterlos a la acción de la disolución de sulfato de sodio, c) las modificaciones estructurales experimentadas por los compuestos cristalinos del cemento hidratado de los lechos sometidos a la acción de la disolución mencionada

Minimally Invasive Approach in Surgery for Congenital Heart Disease

Surgery for congenital heart disease (CHD) has changed considerably during the last decade. Improved surgical results in patients with simple CHD and new interventional cardiology procedures have stimulated the surgeon to adopt minimally invasive techniques to reduce the patient’s surgical insult and obtain good functional and cosmetic results. As a consequence, new surgical techniques and specialized equipment for minimally invasive cardiac surgery (MICS) procedures have been developed and refined in recent years. The improving surgical outcomes in patients with CHD, the significant advances in surgical instrumentation and perfusion technology, and the broad utilization of new catheter-based interventional procedures to repair simple CHD have triggered surgeons’ interest to adopt and innovate minimally invasive approaches for CHD repair, so as to reduce patient’s surgical trauma and improve functional and cosmetic results while maintaining a high standard of clinical outcomes and possibly shortening hospitalization times. This article reports on our updated full experience and institutional protocols with MICS in children and adults with CHD

REGULATION OF BETA-ADRENOCEPTORS ACTIVITYUSING SYNTHETIC LIGHT-REGULATED MOLECULES

Beta-adrenoceptors (ß-AR) are prototypical G proteincoupled receptors and important pharmacological targets for many diseases. Indeed, a number of approved drugs target these receptors due to their key role on many physiological functions. Among other examples, we encounter ß1-AR antagonists (ß- Blockers), which constitute the first-line therapy for the treatment of heart diseases, and ß2-AR agonists, which act as bronchodilators for the treatment of breathing pathologies. Considering the relevance of these receptors, achieving a reversible and localised control of their activity would provide a powerful tool, both for its research applications and its clinical potential. In this context, photopharmacology arises as a potent approach. Photopharmacology is an emerging field based on the use of synthetic light-regulated molecules to allow reversible spatiotemporal control of target receptors in native tissues. These ligands have the potential to provide a precise and controllable therapeutic action with increased efficacy and reduced side effects. Moreover, the fine regulation on demand of the receptor activation state is of great interest for their study in non-modified cells, tissues and organisms. The present project provides the first proof of concept for beta-adrenoceptor photopharmacology. We first designed and synthesised libraries of lightregulated compounds in order to regulate ß-AR activity with spatiotemporal precision. Subsequent testing highlighted the successful development of compounds with promising pharmacological properties which can be reversibly and irreversibly controlled by light. The discovered molecules enable a fine control of ß-AR in their native environment that will certainly open the door to innovative research procedures and may inspire future personalized therapies targeting these receptors

In vitro and in vivo regulation of ß-Adrenoceptors signaling using synthetic light-regulated molecules

Beta-adrenoceptors (ß-AR) are prototypical G protein-coupled receptors (GPCR) and important pharmacological targets for numerous diseases. Indeed, a number of approved drugs target ß-AR, which are key regulators of many physiological functions. Among other examples, ß1-AR antagonists (known as ß-Blockers) are first-line therapies for the treatment of heart failure, and ß2-AR agonists, which act as bronchodilators, are widely used for the treatment of breathing pathologies. Considering the medical relevance of these receptors, achieving a reversible and localized control of their activity would provide a powerful research and clinical tool. GPCR signaling is currently recognized as a multidimensional process governed by molecular, spatial and temporal components. Uncovering the role of each of these dimensions is crucial to improve our knowledge on cell communication, to understand how different pathways give rise to cellular and physiological effects, and to know how can we interact with biological systems with precision using drugs. Photopharmacology is an emerging field in which light-sensitive molecules are used to control the function of a given target protein in native tissues. The modulation of the target activity is achieved by small, drug-like, photoregulated ligands. By the use of light, both spatial and temporal control of the compound activity can be achieved in unprecedented manners compared to conventional pharmacology. These ligands have the potential to provide highly precise and controllable therapeutic actions that may result in increased efficacies and reduced side effects. Importantly, photopharmacology may allow to gain mechanistic insight on the interplay between the activation time and the receptor location during signaling processes in non-modified cells, tissues and whole organisms. Our research focused on the generation of new molecular tools for beta-adrenoceptors photopharmacology will be presented in this communication. First, several libraries of light-sensitive compounds with the aim to regulate ß-AR activity with spatiotemporal precision were designed and synthesized. Subsequent testing in cell preparations demonstrated the successful development of compounds with promising pharmacological properties, which can be reversibly and irreversibly controlled by light. Among those, several hit compounds were identified as ligands for beta-1 and beta-2 adrenoceptors with low nanomolar activities. These libraries compounds were found to be active enough to become useful photopharmacological tools, so we also performed in vivo experiments to determine their research potential in physiological environments. Indeed, the discovered molecules enabled a fine control of ß-AR in their native environment. We believe that the results of these studies will certainly open the door to innovative research procedures and may inspire future therapies targeting ß-AR

Invertebrados edáficos em diferentes sistemas de uso do solo no Município de Quitandinha, PR.

Resumo. FERTBIO 2014