Exploiting the Abstract Calculus Pattern for the Integration of Ordinary Differential Equations for Dynamics Systems: An Object-Oriented Programming Approach in Modern Fortran
This manuscript relates to the exploiting of the abstract calculus pattern (ACP) for the (numerical) solution of ordinary differential equation (ODEs) systems, which are ubiquitous mathematical formulations of many physical (dynamical) phenomena. We present FOODIE, a software suite aimed to numerically solve ODE problems by means of a clear, concise, and efficient abstract interface. The results presented prove manifold findings, in particular that our ACP approach enables ease of code development, clearness and robustness, maximization of code re-usability, and conciseness comparable with computer algebra system (CAS) programming (interpreted) but with the computational performance of compiled programming. The proposed programming model is also proven to be agnostic with respect to the parallel paradigm of the computational architecture: the results show that FOODIE applications have good speedup with both shared (OpenMP) and distributed (MPI, CAF) memory architectures. The present paper is the first announcement of the FOODIE project: the current implementation is extensively discussed, and its capabilities are proved by means of tests and examples.
A technical characterization of APTs by leveraging public resources
Gonzaez-Manzano, Lorena
;
de Fuentes, Josè M.
;
Lombardi, Flavio
;
Ramos, Cristina
Advanced persistent threats (APTs) have rocketed over the last years. Unfortunately, their technical characterization is incomplete--it is still unclear if they are advanced usages of regular malware or a different form of malware. This is key to develop an effective cyberdefense. To address this issue, in this paper we analyze the techniques and tactics at stake for both regular and APT-linked malware. To enable reproducibility, our approach leverages only publicly available datasets and analysis tools. Our study involves 11,651 regular malware and 4686 APT-linked ones. Results show that both sets are not only statistically different, but can be automatically classified with F1 > 0.8 in most cases. Indeed, 8 tactics reach F1 > 0.9. Beyond the differences in techniques and tactics, our analysis shows thats actors behind APTs exhibit higher technical competence than those from non-APT malwares.
Advanced persistent threat; APTs; Malware; MITRE ATT and CK
SRv6 can provide hybrid cooperation between a centralized network controller and network nodes. IPv6 routers maintainmulti-hop ECMP-aware segments, whereas the controller establishes a source-routed path through the network. Since thestate of the flow is defined at the ingress to the network and then is contained in a specific packet header, called SegmentRouting Header (SRH), the importance of such a header itself is vital. Motivated by the need to study and investigate thistechnology, this paper discusses some security-related issues of Segment Routing. A SRv6 capable experimental testbed is built and detailed. Finally, an experimental test campaign is performed and results are evaluated and discussed.
IntroductionThe aim of the study is to understand the evolution of COVID-19 vaccine acceptance over the key 7-month vaccine campaign in Italy, a period in which the country moved from candidate vaccines to products administered to the public. The research focus points to evaluate COVID-19 vaccine attitudes in adults and their children, propension towards compulsory vaccination, past and present adherence to anti-flu and anti-pneumococcal vaccines, and the reasons for trust/mistrust of vaccines.MethodsItalian residents aged 16->65 years were invited to complete an online survey from September 2020 to April 2021. The survey contained 13 questions: 3 on demographic data; 8 on vaccine attitudes; and 2 open-ended questions about the reasons of vaccine confidence/refusal. A preliminary word frequency analysis has been conducted, as well as a statistical bivariate analysis.ResultsOf 21.537 participants, the confidence of those in favor of the COVID-19 vaccine increases of 50 % and the number of people who wanted more information decreases by two-third. Willingness to vaccinate their children against COVID-19 also increased from 51 % to 66.5 %. Only one-third of the strong vaccine-hesitant participants, i.e. 10 %, remained hostile. Compulsory vaccination showed a large and increasing favor by participants up to 78 %, in a way similar to their propensity for children's mandatory vaccination (70.6 %). Respondents' past and present adherence to anti-flu and anti-pneumococcal vaccines does not predict their intentions to vaccinate against COVID-19. Finally, a semantic analysis of the reasons of acceptance/refusal of COVID-19 vaccination suggests a complex decision-making process revealed by the participants' use of common words in pro-and-cons arguments.ConclusionThe heterogeneity in the COVID-19 vaccine hesitancy, determinants and opinions detected at different ages, genders and pandemic phases suggests that health authorities should avoid one-size-fits-all vaccination campaigns. The results emphasize the long-term importance of reinforcing vaccine information, communication and education needs.
Preservation of the angle of reflection when an internal gravity wave hits a sloping boundary generates a focusing mechanism if the angle between the direction of propagation of the incident wave and the horizontal is close to the slope inclination (near-critical reflection). This paper provides an explicit description of the leading approximation of the unique Leray solution to the near-critical reflection of internal waves from a slope in the form of a beam wave. More precisely, our beam wave approach allows to construct a fully consistent and Lyapunov stable approximate solution, L2-close to the Leray solution, in the form of a beam wave, within a certain (nonlinear) time-scale. To the best of our knowledge, this is the first result where a mathematical study of internal waves in terms of spatially localized beam waves is performed.A beam wave is a linear superposition of rapidly oscillating plane waves, where the high frequency of oscillation is proportional to the inverse of a power of the small parameter measuring the weak amplitude of waves.Being localized in the physical space thanks to rapid oscilla- tions (and high variations of the modulus of the wavenumber), beams are physically more relevant than plane waves/packets of waves, whose wavenumber is nearly fixed (microlocalized). At the mathematical level, this marks a strong difference between the previous plane waves/packets of waves analysis and our approach.The main novelty of this work is to exploit the spatial localization of beam waves to exhibit a spatially localized, physically relevant solution and to improve the previous mathematical results from a twofold perspective: 1) our beam wave approximate solution is the sum of a finite number of terms, each of them is a consistent solution to the system and there is no artificial/non-physical corrector; 2) thanks to the absence of artificial correctors (used in the previous results) and to the special structure of the nonlinear term, we can push the expansion of our solution to next orders, so improving the accuracy and enlarging the consistency time-scale.Finally, our results provide a set of initial conditions localized on rays, for which the Leray solution maintains approximately in L2 the same localization.
Real-world facility planning problems often require to tackle simultaneously network connectivity and zonal requirements, in order to guarantee an equitable provision of services and an efficient flow of goods, people and information among the facilities. Nonetheless, such challenges have not been addressed jointly so far. In this paper we explore the introduction of advanced network connectivity features and spatial-related requirements within Covering Location Problems. We adopt a broad modelling perspective, accounting for structural and economic aspects of connectivity features, while allowing the choice for one or more facilities to serve the facility networks as depots, and containing the maximal distance between any active facility and such depot(s). A novel class of Multi-objective Covering Location problems are proposed, utilising Mixed Integer Linear Programming as a modelling tool. Aiming at obtaining efficiently the arising Pareto Sets and providing actionable decision-making support throughout real planning processes, we adapt to our problem the robust variant of the AUGMEnted ?-CONstraint method (AUGMECON-R). Furthermore, we exploit the mathematical properties of the proposed problems to design tailored Matheuristic algorithms which boost the scalability of the solution method, with particular reference to the case of multiple depots. By conducting a comprehensive computational study on benchmark instances, we provide a thorough proof of concept for the novel problems, highlighting the challenging nature of the advanced connectivity features and the scalability of the proposed Matheuristics. From a managerial standpoint, the suitability of the proposed work in responding effectively to the motivating needs is showcased.
Dissolution of drug from its solid form to a dissolved form is an important consideration in the design and
optimization of drug delivery devices, particularly owing to the abundance of emerging compounds that are
extremely poorly soluble. When the solid dosage form is encapsulated, for example by the porous walls of an
implant, the impact of the encapsulant drug transport properties is a further confounding issue. In such a case,
dissolution and diffusion work in tandem to control the release of drug. However, the interplay between these
two competing processes in the context of drug delivery is not as well understood as it is for other mass transfer
problems, particularly for practical controlled-release considerations such as an encapsulant layer around the
drug delivery device. To address this gap, this work presents a mathematical model that describes controlled
release from a drug-loaded device surrounded by a passive porous layer. A solution for the drug concentration
distribution is derived using the method of eigenfunction expansion. The model is able to track the dissolution
front propagation, and predict the drug release curve during the dissolution process. The utility of the model is
demonstrated through comparison against experimental data representing drug release from a cylindrical drugloaded
orthopedic fixation pin, where the model is shown to capture the data very well. Analysis presented here
reveals how the various geometrical and physicochemical parameters influence drug dissolution and, ultimately,
the drug release profile. It is found that the non-dimensional initial concentration plays a key role in determining
whether the problem is diffusion-limited or dissolution-limited, whereas the nature of the problem is largely
independent of other parameters including diffusion coefficient and encapsulant thickness. We expect the model
will prove to be a useful tool for those designing encapsulated drug delivery devices, in terms of optimizing the
design of the device to achieve a desired drug release profile.
dissolution
diffusion
drug delivery
front propagation
This paper investigates the model for pedestrian flow firstly proposed in [Cristiani, Priuli, and Tosin, SIAM J. Appl. Math., 75:605-629, 2015]. The model assumes that each individual in the crowd moves in a known domain, aiming at minimizing a given cost functional. Both the pedestrian dynamics and the cost functional itself depend on the position of the whole crowd. In addition, pedestrians are assumed to have predictive abilities, but limited in time.
pedestrian dynamics
mean-field games
Fokker-Planck equation
Hamilton-Jacobi-Bellman equation
evacuation problems
In this paper we deal with pedestrian modeling, aiming at simulating crowd behavior in normal and emergency scenarios, including highly congested mass events. We are specifically concerned with a new agent-based, continuous-in-space, discrete-in-time, nondifferential model, where pedestrians have finite size and are compressible to a certain extent. The model also takes into account the pushing behavior appearing at extremely high densities. The main novelty is that pedestrians are not assumed to generate any kind of "field" which governs the dynamics of the others in the space around them. Instead, the behavior of each pedestrian solely relies on its knowledge of the environment and the evaluation of interpersonal distances between it and the others. The model is able to reproduce the concave/concave fundamental diagram with a "double hump" (i.e. with a second peak) which shows up when body forces come into play. We present several numerical tests (some of them being inspired by the recent ISO 20414 standard), which show how the model can reproduce classical self-organizing patterns.
Computer Vision and 3D printing have rapidly evolved in the last 10 years but interactions among them have been very limited so far, despite the fact that they share several mathematical techniques. We try to fill the gap presenting an overview of some techniques for Shape-from-Shading problems as well as for 3D printing with an emphasis on the approaches based on nonlinear partial differential equations and optimization. We also sketch possible couplings to complete the process of object manufacturing starting from one or more images of the object and ending with its final 3D print. We will give some practical examples of this procedure.
Shape-from-shading
Photometric stereo technique
Multi-view SfS
3D vision
3D printing
Overhangs
Infill
Presents several mathematical problems for 3D and 3D printing plus a survey that gives the links between the two areas
Contains contributions from highly reputed academic and industrial researchers with a long experience
Shows several techniques, applications and benchmarks that can be useful for young researchers approaching the field
Mathematical modeling
3D vision
3D printing
Level set methods and shape optimization
Hamilton-Jacobi equations
The aberrant epigenome of DNMT3B-mutated ICF1 patient iPSCs is amenable to correction, with the exception of a subset of regions with H3K4me3- and/or CTCF-based epigenetic memory
Bi-allelic hypomorphic mutations in DNMT3B disrupt DNA methyltransferase activity and lead to immunodeficiency, centromeric instability, facial anomalies syndrome, type 1 (ICF1). Although several ICF1 phenotypes have been linked to abnormally hypomethylated repetitive regions, the unique genomic regions responsible for the remaining disease phenotypes remain largely uncharacterized. Here we explored two ICF1 patient-derived induced pluripotent stem cells (iPSCs) and their CRISPR-Cas9-corrected clones to determine whether DNMT3B correction can globally overcome DNA methylation defects and related changes in the epigenome. Hypomethylated regions throughout the genome are highly comparable between ICF1 iPSCs carrying different DNMT3B variants, and significantly overlap with those in ICF1 patient peripheral blood and lymphoblastoid cell lines. These regions include large CpG island domains, as well as promoters and enhancers of several lineage-specific genes, in particular immune-related, suggesting that they are premarked during early development. CRISPR-corrected ICF1 iPSCs reveal that the majority of phenotype-related hypomethylated regions reacquire normal DNA methylation levels following editing. However, at the most severely hypomethylated regions in ICF1 iPSCs, which also display the highest increases in H3K4me3 levels and/or abnormal CTCF binding, the epigenetic memory persists, and hypomethylation remains uncorrected. Overall, we demonstrate that restoring the catalytic activity of DNMT3B can reverse the majority of the aberrant ICF1 epigenome. However, a small fraction of the genome is resilient to this rescue, highlighting the challenge of reverting disease states that are due to genome-wide epigenetic perturbations. Uncovering the basis for the persistent epigenetic memory will promote the development of strategies to overcome this obstacle.
Co-Occurrence of Beckwith-Wiedemann Syndrome and Early-Onset Colorectal Cancer
Francesco Cecere
;
Laura Pignata
;
Bruno Hay Mele
;
Abu Saadat
;
Emilia D'Angelo
;
Orazio Palumbo
;
Pietro Palumbo
;
Massimo Carella
;
Gioacchino Scarano
;
Giovanni Battista Rossi
;
Claudia Angelini
;
Angela Sparago
;
Flavia Cerrato
;
Andrea Riccio
CRC is an adult-onset carcinoma representing the third most common cancer and the second leading cause of cancer-related deaths in the world. EO-CRC (<45 years of age) accounts for 5% of the CRC cases and is associated with cancer-predisposing genetic factors in half of them. Here, we describe the case of a woman affected by BWSp who developed EO-CRC at age 27. To look for a possible molecular link between BWSp and EO-CRC, we analysed her whole-genome genetic and epigenetic profiles in blood, and peri-neoplastic and neoplastic colon tissues. The results revealed a general instability of the tumor genome, including copy number and methylation changes affecting genes of the WNT signaling pathway, CRC biomarkers and imprinted loci. At the germline level, two missense mutations predicted to be likely pathogenic were found in compound heterozygosity affecting the Cystic Fibrosis (CF) gene CFTR that has been recently classified as a tumor suppressor gene, whose dysregulation represents a severe risk factor for developing CRC. We also detected constitutional loss of methylation of the KCNQ1OT1:TSS-DMR that leads to bi-allelic expression of the lncRNA KCNQ1OT1 and BWSp. Our results support the hypothesis that the inherited CFTR mutations, together with constitutional loss of methylation of the KCNQ1OT1:TSS-DMR, initiate the tumorigenesis process. Further somatic genetic and epigenetic changes enhancing the activation of the WNT/beta-catenin pathway likely contributed to increase the growth advantage of cancer cells. Although this study does not provide any conclusive cause-effect relationship between BWSp and CRC, it is tempting to speculate that the imprinting defect of BWSp might accelerate tumorigenesis in adult cancer in the presence of predisposing genetic variants.
Beckwith-Wiedemann syndrome
genomic imprinting
DNA Methylation
Epigenetic modifications are correlated to environmental factors. Exposure to ambient air pollution may contribute to the development of different diseases such as cancer, cardiovascular diseases, and neurological and metabolic disorders. Looking for the association between DNA methylation and exposure biomarkers may help in the prevention of adverse effects. Association analysis can be carried out through regression modeling. When dealing with the association between DNA methylation and pollutants, the response variable is beta-distributed, and linear regression models are not appropriate when the range is limited to (0, 1). Beta regression models are more suitable for this situation. Methylation levels can also be measured through the M-value statistic and association studies may be performed using classical linear regression models or robust linear regression models in the presence of outliers. An alternative to these models when the variable of interest does not behave linearly in all the predictors is given by a generalized linear model framework that incorporates non-linear terms and interactions. In this paper, we applied these models to a case study constituted of a cohort of healthy people living in regions exposed to different levels of pollution to investigate the association between DNA methylation and cadmium exposure.
DNA methylation
Regression models
pollution exposure