Better Safe Than Sorry: An Adversarial Approach to Improve Social Bot Detection

The arm race between spambots and spambot-detectors is made of several cycles (or generations): a new wave of spambots is created (and new spam is spread), new spambot filters are derived and old spambots mutate (or evolve) to new species. Recently, with the diffusion of the adversarial learning approach, a new practice is emerging: to manipulate on purpose target samples in order to make stronger detection models. Here, we manipulate generations of Twitter social bots, to obtain - and study - their possible future evolutions, with the aim of eventually deriving more effective detection techniques. In detail, we propose and experiment with a novel genetic algorithm for the synthesis of online accounts. The algorithm allows to create synthetic evolved versions of current state-of-the-art social bots. Results demonstrate that synthetic bots really escape current detection techniques. However, they give all the needed elements to improve such techniques, making possible a proactive approach for the design of social bot detection systems.Comment: This is the pre-final version of a paper accepted @ 11th ACM Conference on Web Science, June 30-July 3, 2019, Boston, U

Misurazioni

Mario Cresci ha dato vita tra il 1977 e il 1979 ad una esperienza, estremamente significativa e molto interessante, che si è interrotta poiché non più supportata istituzionalmente e quindi si configura come un progetto che, seppur già perfettamente messo a punto, resta irrealizzato o, quantomeno, incompiuto. In Basilicata, dove già da anni l’autore portava avanti Misurazioni, la sua ricerca fotografica di chiara marca antropologica e sociale, Cresci si impegna nella didattica presso un istituto molto particolare. Si tratta di una scuola di design, istituita dalla Regione Basilicata, in applicazione della legge n. 285 del 1 giugno 1977 e destinata alla formazione professionale per le tecniche artigianali. Una scuola, insomma, che cerca di sfruttare la creatività come risorsa economica. Il progetto si è purtroppo subito interrotto, restando in sostanza irrealizzato, poiché le istituzioni non hanno più sostenuto questo istituto.Mario Cresci started between 1977 and 1979 a meaningful and interesting experience that was interrupted because of the lack of support from the institutions and can therefore be conceived as an unrealised or at least unfinished project. In Basilicata, where the author was already developing the project Misurazioni, a photographic research with a social and anthropological approach, Cresci started teaching in an unusual school. A design school, founded by Regione Basilicata in application of the law n. 285 of June 1st 1977, devoted to the vocational training in craftsmanship techniques. A school that aimed at using creativity as an economic resource. Unfortunately the project was interrupted almost immediately, remaining therefore unrealized, since the institutions suspended their support to the school

PPAR genomics and pharmacogenomics: Implications for cardiovascular disease

The peroxisome proliferator-activated receptors (PPARs) consist of three related transcription factors that serve to regulate a number of cellular processes that are central to cardiovascular health and disease. Numerous pharmacologic studies have assessed the effects of specific PPAR agonists in clinical trials and have provided insight into the clinical effects of these genes while genetic studies have demonstrated clinical associations between PPAR polymorphisms and abnormal cardiovascular phenotypes. With the abundance of data available from these studies as a background, PPAR pharmacogenetics has become a promising and rapidly advancing field. This review focuses on summarizing the current state of understanding of PPAR genetics and pharmacogenetics and the important implications for the individualization of therapy for patients with cardiovascular diseases

An X-ray/SDSS sample (II): outflowing gas plasma properties

Galaxy-scale outflows are nowadays observed in many active galactic nuclei (AGNs); however, their characterisation in terms of (multi-) phase nature, amount of flowing material, effects on the host galaxy, is still unsettled. In particular, ionized gas mass outflow rate and related energetics are still affected by many sources of uncertainties. In this respect, outflowing gas plasma conditions, being largely unknown, play a crucial role. Taking advantage of the spectroscopic analysis results we obtained studying the X-ray/SDSS sample of 563 AGNs at z $<0.8$ presented in our companion paper, we analyse stacked spectra and sub-samples of sources with high signal-to-noise temperature- and density-sensitive emission lines to derive the plasma properties of the outflowing ionized gas component. For these sources, we also study in detail various diagnostic diagrams to infer information about outflowing gas ionization mechanisms. We derive, for the first time, median values for electron temperature and density of outflowing gas from medium-size samples ($\sim 30$ targets) and stacked spectra of AGNs. Evidences of shock excitation are found for outflowing gas. We measure electron temperatures of the order of $\sim 1.7\times10^4$ K and densities of $\sim 1200$ cm$^{-3}$ for faint and moderately luminous AGNs (intrinsic X-ray luminosity $40.5<log(L_X)<44$ in the 2-10 keV band). We caution that the usually assumed electron density ($N_e=100$ cm$^{-3}$) in ejected material might result in relevant overestimates of flow mass rates and energetics and, as a consequence, of the effects of AGN-driven outflows on the host galaxy.Comment: 16 pages, 10 figures. Accepted for publication in A&

Cashtag piggybacking: uncovering spam and bot activity in stock microblogs on Twitter

Microblogs are increasingly exploited for predicting prices and traded volumes of stocks in financial markets. However, it has been demonstrated that much of the content shared in microblogging platforms is created and publicized by bots and spammers. Yet, the presence (or lack thereof) and the impact of fake stock microblogs has never systematically been investigated before. Here, we study 9M tweets related to stocks of the 5 main financial markets in the US. By comparing tweets with financial data from Google Finance, we highlight important characteristics of Twitter stock microblogs. More importantly, we uncover a malicious practice - referred to as cashtag piggybacking - perpetrated by coordinated groups of bots and likely aimed at promoting low-value stocks by exploiting the popularity of high-value ones. Among the findings of our study is that as much as 71% of the authors of suspicious financial tweets are classified as bots by a state-of-the-art spambot detection algorithm. Furthermore, 37% of them were suspended by Twitter a few months after our investigation. Our results call for the adoption of spam and bot detection techniques in all studies and applications that exploit user-generated content for predicting the stock market

Integral field spectroscopy in the near infrared of NGC 3125-A and SBS 0335-052

We present integral field spectroscopy in the near infrared of the nearby dwarf starburst galaxies NGC 3125-A and of the low metallicity dwarf galaxy SBS 0335-052. The use of adaptive optics in the observations produces sub-arcsecond angular resolution. We pinpoint the star forming cores of both galaxies, identify relevant ISM components such as dust, photo ionized gas, shock excited gas and molecular gas. We relate these components to the large scale star formation process of the galaxies. In particular we find the emission of the near infrared lines of H2 and especially [FeII] does not coincide with the HII region in NGC 3125. We have the first clear detection of [FeII] in SBS 0335-052