1,721,071 research outputs found
An ASP Framework for Efficient Urban Traffic Optimization
Full text linkAvoiding congestion and controlling traffic in urban scenarios is becoming nowadays of paramount importance due to the rapid growth of our cities’ population and vehicles. The effective control of urban traffic as a means to mitigate congestion can be beneficial in an economic, environmental and
health way. In this paper, a framework which allows to efficiently simulate and optimize traffic flow in a large roads’ network with hundreds of vehicles is presented. The framework leverages on an Answer Set Programming (ASP) encoding to formally describe the movements of vehicles inside
a network. Taking advantage of the ability to specify optimization constraints in ASP and the offthe-shelf solver CLINGO, it is then possible to optimize the routes of vehicles inside the network to reduce a range of relevant metrics (e.g., travel times or emissions). Finally, an analysis on real-world
traffic data is performed, utilizing the state-of-the-art Urban Mobility Simulator (SUMO) to keep track of the state of the network, test the correctness of the solution and to prove the efficiency and capabilities of the presented solution
TIMP3: un nuovo biomarcatore di aterosclerosi nel Diabete Mellito di tipo 2: studi in vivo ed in vitro
Full text linkNei pazienti affetti da Diabete Mellito di Tipo 2 l’aterosclerosi è fortemente accelerata da meccanismi ancora oggi sconosciuti. Il nostro gruppo recentemente ha identificato l’Inibitore Tissutale delle Metalloproteinasi 3 (TIMP3), che è l’inibitore endogeno dell’enzima TNF Converting Enzyme (TACE), anche chiamato A Disintegrin and Metalloproteasi Domain 17 (ADAM17) e di altre MetalloProteasi di Matrice (MMP), come un gene favorente lo sviluppo di insulino resistenza e infiammazione vascolare nel topo.
Abbiamo quindi ipotizzato che un’aumentata attività del sistema proteolitico di membrana extracellulare, dovuta ad una alterata regolazione della diade ADAM17/TIMP3, possa essere un fattore comune allo sviluppo e progressione dell’aterosclerosi, dell’insulino resistenza e del diabete. Ulteriore scopo di questo lavoro è valutare l’associazione di TIMP3 con l’aterosclerosi in pazienti affetti da Diabete Mellito di Tipo 2 (DM2) ed identificare fattori in grado di regolare l’espressione di TIMP3.
I substrati solubili circolanti di ADAM17/TACE, quali sICAM-1, sVCAM-1, sIL6R, sCXCL16 e sTNFR1, sono stati analizzati nei sieri di soggetti sani di controllo (CT, n=70), pazienti con Aterosclerosi Carotidea (CAR-Ats, n=35) e pazienti con Coronaropatia (CAD, n=170). Inoltre abbiamo valutato i livelli di espressione di ADAM10/17, MMP9, TIMP1/2/3/4 in placche aterosclerotiche carotidee umane (n=60) prelevate da pazienti con e senza diabete sottoposti ad Endoarteriectomia carotidea. Cellule muscolari lisce vascolari umane esposte a diversi stimoli metabolici sono state utilizzate per identificare i regolatori dell’espressone di Timp3. Il silenziamento genico di SirT1 mediante small interference RNA (siRNA), SirT1 cDNA e un vettore reporter per il promotore del gene TIMP3 sono stati usati per studiare la regolazione dell’espressione di TIMP3 da parte di SirT1.
In questo lavoro abbiamo riscontrato che, fra i substrati solubili di ADAM17/TACE, sCXCL16, sICAM-1 e sVCAM1 sono differentemente e significativamente aumentati a seconda della localizzazione della patologia vascolare aterosclerotica e dell’alterazione del metabolismo glucidico.
Abbiamo inoltre mostrato che nelle placche aterosclerotiche carotidee umane i livelli di espressione di TIMP3 sono significativamente ridotti nei soggetti con diabete mellito di tipo 2 con un conseguente aumento dell’attività di ADAM17/TACE e MMP9. La ridotta espressione di TIMP3 è stata associata in vivo ai livelli di SirT1. Nelle cellule muscolari lisce vascolari umane, l’inibizione dell’attività e dei livelli di SirT1 determina una riduzione dell’espressione di TIMP3, mentre una sovra-espressione di SirT1 aumenta l’attività del promotore di TIMP3.
In conclusione, i nostri dati suggeriscono che il sistema proteolitico di membrana è gradualmente attivato in soggetti con differente localizzazione della patologia aterosclerotica. Inoltre nelle placche aterosclerotiche di soggetti con il diabete mellito di tipo 2 la deregolazione dell’attività di ADAM17/TACE e delle MMP9 è correlata con un’inadeguata espressione di TIMP3 SirT1-dipendente. Gli studi effettuati su cellule vascolari confermano il ruolo di Sirt1 nel modulare l’espressione di TIMP3.Atherosclerosis is accelerated in patients with Type 2 Diabetes Mellitus (DM2) by unknown mechanisms. We identified Tissue Inhibitor of Metalloproteinase 3 (TIMP3), the endogenous inhibitor of A Disintegrin and Metalloprotease Domain 17 (ADAM17) and other Matrix MetalloProteinase (MMP), as a gene modifier for insulin resistance and vascular inflammation in mice. Therefore we hypothesized that an increased activity of the ectodomain shedding process, due to a dysregulation of ADAM17/Timp3 dyad, may be a common factor linking progression of atherosclerosis to insulin resistance and diabetes. Here we also tested TIMP3 association with atherosclerosis in patients with type 2 diabetes mellitus (DM2) and identified Sirtuin 1 (SirT1) as a major regulator of TIMP3 expression.
ADAM17 substrates, such as soluble (s)ICAM-1, sVCAM-1, sIL6R, sCXCL16 and sTNFR1, were analyzed in serum from healthy subjects (CT, n=70), patients with Carotid Atherosclerosis (CAR-ATS, n=35) and patients with Coronary Artery Disease (CAD, n=170). Moreover we investigated ADAM10/17, MMP9, TIMP1/2/3/4 expression levels in human carotid atherosclerotic plaques (n=60) from subjects with and without diabetes. Human Vascular Smooth Muscle cells exposed to several metabolic stimuli were used to identify regulators of Timp3 expression. SirT1 small interference RNA (siRNA), cDNA and TIMP3 promoter gene reporter were used to study SirT1 dependent regulation of TIMP3.
We found that, among soluble ADAM17 substrates, sCXCL16, sICAM-1 and sVCAM1 were differently and significantly increased according to location of vascular disease and impairment of glucose metabolism. We showed that in human carotid atherosclerotic plaques TIMP3 was significantly reduced in subjects with DM2 leading to ADAM17 and MMP9 overactivity. Reduced expression of TIMP3 was associated in vivo to SirT1 levels. In smooth muscle cells, inhibition of SirT1 activity and levels reduced TIMP3 expression, while SirT1 overexpression increased TIMP3 promoter activity.
In conclusion, our data suggest that the ectodomain shedding process is gradually activated in patients with different location of atherosclerotic disease. Moreover in atherosclerotic plaques from subjects with Type 2 diabetes the deregulation of ADAM17 and MMP9 activities is related to inadequate expression of TIMP3 via SirT1. Studies in vascular cells confirmed the role of SirT1 in tuning TIMP3 expression
Symbolic Numeric Planning with Patterns
No full textIn this paper, we propose a novel approach for solving linear numeric planning problems, called Symbolic Pattern Planning. Given a planning problem Π, a bound n and a pattern –defined as an arbitrary sequence of actions– we encode the problem of finding a plan for Π with bound n as a formula with fewer variables and/or clauses than the state-of-the-art rolled-up and relaxed-relaxed-∃ encodings. More importantly, we prove that for any given bound, it is never the case that the latter two encodings allow finding a valid plan while ours does not. On the experimental side, we consider 6 other planning systems –including the ones which participated in this year’s International Planning Competition (IPC)– and we show that our planner PATTY has remarkably good comparative performances on this year’s IPC problems
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
In-Station Train Dispatching: A PDDL+ Planning Approach
No full textIn railway networks, stations are probably the most critical points for interconnecting trains’ routes: in a restricted geographical area, a potentially large number of trains have to stop according to an official timetable, with the concrete risk of accumulating delays that can then have a knockout effect on the rest of the network. In this context, in-station train dispatching plays a central role in maximising the effective utilisation of available railway infrastructures and in mitigating the impact of incidents and delays. Unfortunately, in-station train dispatching is still largely handled manually by human operators in charge of a group of stations. In this paper we make a step towards supporting the operator with some automatic tool, by describing an approach for performing in-station dispatching by means of automated planning techniques. Given the mixed discrete-continuous nature of the problem, we employ PDDL+ for the specification of the problem, and the ENHSP planning engine enhanced by domain-specific solving techniques. Results on a range of scenarios, using real-data of a station of the North West of Italy, show the potential of our approach
Taming Discretised PDDL+ through Multiple Discretisations
No full textThe PDDL+ formalism allows the use of planning techniques in applications that require the ability to perform hybrid discrete-continuous reasoning. PDDL+ problems are notoriously challenging to tackle, and to reason upon them a well-established approach is discretisation. Existing systems rely on a single discretisation delta or, at most, two: a simulation delta to model the dynamics of the environment, and a planning delta, that is used to specify when decisions can be taken. However, there exist cases where this rigid schema is not ideal, for instance when agents with very different speeds need to cooperate or interact in a shared environment, and a more flexible approach that can accommodate more deltas is necessary. To address the needs of this class of hybrid planning problems, in this paper we introduce a reformulation approach that allows the encapsulation of different levels of discretisation in PDDL+ models, hence allowing any domain-independent planning engine to reap the benefits. Further, we provide the community with a new set of benchmarks that highlights the limits of fixed discretisation
A Planning-based Approach for In-Station Train Dispatching
No full textIn-station train dispatching is the problem of optimising the effective utilisation of available railway infrastructures for mitigating incidents and delays. In this paper, we describe an approach for dealing with the in-station dispatching problem by means of automated planning techniques
An Efficient Hybrid Planning Framework for In-Station Train Dispatching
Full text linkIn-station train dispatching is the problem of optimising the effective utilisation of available railway infrastructures for mitigating incidents and delays. This is a fundamental problem for the whole railway network efficiency, and in turn for the transportation of goods and passengers, given that stations are among the most critical points in networks since a high number of interconnections of trains’ routes holds therein. Despite such importance, nowadays in-station train dispatching is mainly managed manually by human operators. In this paper we present a framework for solving in-station train dispatching problems, to support human operators in dealing with such task. We employ automated planning languages and tools for solving the task: PDDL+ for the specification of the problem, and the ENHSP planning engine, enhanced by domain-specific techniques, for solving the problem. We carry out a in-depth analysis using real data of a station of the North West of Italy, that shows the effectiveness of our approach and the contribution that domain-specific techniques may have in efficiently solving the various instances of the problem. Finally, we also present a visualisation tool for graphically inspecting the generated plans
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