An improved Belief Propagation algorithm finds many Bethe states in the random field Ising model on random graphs

We first present an empirical study of the Belief Propagation (BP) algorithm, when run on the random field Ising model defined on random regular graphs in the zero temperature limit. We introduce the notion of maximal solutions for the BP equations and we use them to fix a fraction of spins in their ground state configuration. At the phase transition point the fraction of unconstrained spins percolates and their number diverges with the system size. This in turn makes the associated optimization problem highly non trivial in the critical region. Using the bounds on the BP messages provided by the maximal solutions we design a new and very easy to implement BP scheme which is able to output a large number of stable fixed points. On one side this new algorithm is able to provide the minimum energy configuration with high probability in a competitive time. On the other side we found that the number of fixed points of the BP algorithm grows with the system size in the critical region. This unexpected feature poses new relevant questions on the physics of this class of models.Comment: 20 pages, 8 figure

R+EVUE THE B-SIDE

Visible from only one perspective at a time, architecture suffers the fate of never revealing itself as a whole. An inherent duplicity arises between what can be seen and what remains hidden. The back side—which never shows a representative face nor welcomes us into the building and rarely gets printed in glossy architecture magazines—is the overlooked side of architecture. As a result, we studied the backs of a few famous buildings. What we found is the B-side of architecture. Liberated from the front’s representative obligations, the B-side is an ambiguous space of programmatic, representative, contextual or even ideological experimentation. We represent our discoveries through a series of analytical and experimental drawings

R+EVUE 20%

Organizational and administrative activities have shed their typological corset. Having cut spatial ties to the office, they are now at home almost anywhere. According to current studies, around 20% of office space in Germany will be obsolete in the medium term . This corresponds to a floor area of more than 75 million square meters. Calculated against the average per capita living space of 47,7 sqm , this represents enough space to house almost 2 million people. This equation is grossly simplified. It is problematic for, amongst other reasons, its exclusion of variables such as a building’s structural character, its urban location, and its proximity to technical and social infrastructures. The current demand for living space - especially in metropolitan areas - and the simultaneous necessity to establish more sustainable architectural practices, makes the conversion of existing buildings inevitable. This brings the above-mentioned issues to the fore, and will require the analysis of these buildings’ potentials and the architectural tools for exploiting them. R+EVUE 2 presents ten case studies, each making use of the same already-vacant office structure: an administrative building from the 1970s in Hamburg Wansbek. The object under investigation serves as a stand-in for the office buildings which pervade the peripheries of large German cities. Through consideration of this building’s specific structural and urban characteristics, various strategies for reappropriation are examined. The studies were produced systematically: the same office structure superimposed with ten residential projects, selected to form a broad typological spectrum. The frictions and conflicts which arise during this overlay process become catalysts for specific design solutions and raise more general questions about the reappropriation of existing structures. By adapting the characteristic typological features of the residential buildings to the structure of the office building, new and unexpected approaches are generated. The depth and extent of each study’s intervention is measurable against the existing structure. In the form of red-yellow plans and visualizations, both demolition measures and structural additions are clearly illustrated. The excerpt from the portfolio of office buildings is contrasted with a selection of residential building references. The ten residential building references cover a wide range of different circulation typologies, apartment types, construction principles and scales. The different housing references are all projected onto the structure of one vacant office building. Because its concrete skeleton is typical for an entire generation of commercial structures, the findings of the housing projections resonate beyond this specific case study

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Intelligenza artificiale e sicurezza: opportunità, rischi e raccomandazioni

L'IA (o intelligenza artificiale) è una disciplina in forte espansione negli ultimi anni e lo sarà sempre più nel prossimo futuro: tuttavia è dal 1956 che l’IA studia l’emulazione dell’intelligenza da parte delle macchine, intese come software e in certi casi hardware. L’IA è nata dall’idea di costruire macchine che - ispirandosi ai processi legati all’intelligenza umana - siano in grado di risolvere problemi complessi, per i quali solitamente si ritiene che sia necessario un qualche tipo di ragionamento intelligente. La principale area di ricerca e applicazione attuale dell’IA è il machine learning (algoritmi che imparano e si adattano in base ai dati che ricevono), che negli ultimi anni ha trovato ampie applicazioni grazie alle reti neurali (modelli matematici composti da neuroni artificiali) che a loro volta hanno consentito la nascita del deep learning (reti neurali di maggiore complessità). Appartengono al mondo dell’IA anche i sistemi esperti, la visione artificiale, il riconoscimento vocale, l’elaborazione del linguaggio naturale, la robotica avanzata e alcune soluzioni di cybersecurity. Quando si parla di IA c'è chi ne è entusiasta pensando alle opportunità, altri sono preoccupati poiché temono tecnologie futuristiche di un mondo in cui i robot sostituiranno l'uomo, gli toglieranno il lavoro e decideranno al suo posto. In realtà l'IA è ampiamente utilizzata già oggi in molti campi, ad esempio nei cellulari, negli oggetti smart (IoT), nelle industry 4.0, per le smart city, nei sistemi di sicurezza informatica, nei sistemi di guida autonoma (drive o parking assistant), nei chat bot di vari siti web; questi sono solo alcuni esempi basati tutti su algoritmi tipici dell’intelligenza artificiale. Grazie all'IA le aziende possono avere svariati vantaggi nel fornire servizi avanzati, personalizzati, prevedere trend, anticipare le scelte degli utenti, ecc. Ma non è tutto oro quel che luccica: ci sono talvolta problemi tecnici, interrogativi etici, rischi di sicurezza, norme e legislazioni non del tutto chiare. Le organizzazioni che già adottano soluzioni basate sull’IA, o quelle che intendono farlo, potrebbero beneficiare di questa pubblicazione per approfondirne le opportunità, i rischi e le relative contromisure. La Community for Security del Clusit si augura che questa pubblicazione possa fornire ai lettori un utile quadro d’insieme di una realtà, come l’intelligenza artificiale, che ci accompagnerà sempre più nella vita personale, sociale e lavorativa.AI (or artificial intelligence) is a booming discipline in recent years and will be increasingly so in the near future.However, it is since 1956 that AI has been studying the emulation of intelligence by machines, understood as software and in some cases hardware. AI arose from the idea of building machines that-inspired by processes related to human intelligence-are able to solve complex problems, for which it is usually believed that some kind of intelligent reasoning is required. The main current area of AI research and application is machine learning (algorithms that learn and adapt based on the data they receive), which has found wide applications in recent years thanks to neural networks (mathematical models composed of artificial neurons), which in turn have enabled the emergence of deep learning (neural networks of greater complexity). Also belonging to the AI world are expert systems, computer vision, speech recognition, natural language processing, advanced robotics and some cybersecurity solutions. When it comes to AI there are those who are enthusiastic about it thinking of the opportunities, others are concerned as they fear futuristic technologies of a world where robots will replace humans, take away their jobs and make decisions for them. In reality, AI is already widely used in many fields, for example, in cell phones, smart objects (IoT), industries 4.0, for smart cities, cybersecurity systems, autonomous driving systems (drive or parking assistant), chat bots on various websites; these are just a few examples all based on typical artificial intelligence algorithms. Thanks to AI, companies can have a variety of advantages in providing advanced, personalized services, predicting trends, anticipating user choices, etc. But not all that glitters is gold: there are sometimes technical problems, ethical questions, security risks, and standards and legislation that are not entirely clear. Organizations already adopting AI-based solutions, or those planning to do so, could benefit from this publication to learn more about the opportunities, risks, and related countermeasures. Clusit's Community for Security hopes that this publication will provide readers with a useful overview of a reality, such as artificial intelligence, that will increasingly accompany us in our personal, social and working lives

La poetica del telaio in cemento armato

Il telaio in cemento armato è stato sempre trattato a margine di un discorso incentrato su uno dei suoi due componenti: la struttura o il materiale. Nessuno di questi punti di vista lo considera in quanto tema a sé stante. Eppure è l'unione del sistema strutturale e del materiale che conferisce al telaio in cemento armato una specificità che non può essere trattata solo a margine di un altro discorso. Mentre la teoria esplorava i limiti generici del frame, nella pratica, l'uso sapiente del telaio in cemento ha attraversato l'ultimo secolo riaffiorando sporadicamente fra le mani di chi l'ha saputo far rivivere. In questo processo la stessa nota poetica ha cambiato di volta in volta tono e senso adattandosi al contesto storico e culturale di riferimento e alle esigenze espressive del singolo caso, ma mantenendo, di autore in autore un carattere riconoscibile. La tesi si snoda lungo tre serie di telai a formare un campo o un "quadro". L'indagine sulla poetica del telaio in cemento armato ha preso avvio dal "ritrovamento" di tre telai con uno statuto particolare. Si tratta di tre telai in cemento armato privi di volta in volta, di una diversa condizione al contorno che ne influenzerebbe la forma. Ognuno di questi telai si trova in un luogo astratto in cui sono ridotte le fonti di perturbazione. In questo ambiente controllato a metà fra il laboratorio dello scienziato e il banco dell'alchimista sono stati dunque eseguiti tre esperimenti mentali. Ogni esperimento mentale ha prodotto dei concetti operativi (potremmo dire scientifici) che possono essere utilizzati come strumenti d'indagine poetica nel proseguo della tesi. Si tratta di riflessioni sull'uso compositivo del materiale geometrico fondamentale dello spazio, fatto di rapporti fra le misure, modularità dell'ideale e scomponibilità del reale, della capacità di generare serie a partire da un numero limitato di ripetizioni. Gli esperimenti mentali insegnano a riconoscere la suscettività emotiva che attraversa il telaio secondo una "statica della sensazione" che non dipende dall'effettiva sollecitazione tensionale della struttura. Il corpo integrale del telaio diventa un materiale solido, la cui struttura (struttura della materia) è descrivibile tutt'al più secondo un criterio di densità o rarefazione del suo reticolo cristallino. Il telaio in cemento armato diventa così la materia stessa dello spazio, la materia duttile del possibile. Ho quindi selezionato quegli esempi che potessero essere organizzati a formare due serie, due esplorazioni "campione" che aprono una "serie di serie" di altre le possibili esplorazioni attorno al tema del telaio in cemento armato. Ogni serie propone l'evoluzione di una maniera di intendere il telaio in cemento armato: come aggregazione di cellule minime e come suddivisione di un'unità integrale. Si potrebbe dire che la struttura della tesi passi per 6 punti ad alta concentrazione di informazioni. 6 pilastri concettuali in cui si sono indagate le intenzioni progettuali degli autori e i risvolti, enunciati o meno, dell'opera realizzata, fino a riattivare un insieme di discorsi che rivelano il portato poetico profondo di ogni telaio. Il contributo alla disciplina apportato da questo tipo di confronti riguarda sia i casi presi in esame singolarmente, nel rivelare interpretazioni nuove rispetto a quelle già affermate, sia il piano di discussione che si apre fra di loro riguardo al potenziale poetico del telaio

Semantic description of three-dimensional models of Bologna porches

The study is part of a broader search coordinated by the Department of Architecture of the University of Bologna, the Cineca and the city of Bologna for the nomination of the city porticoes in the UNESCO World Heritage Site. The study describes, first, the problems and the methods adopted for the survey, the numerical modeling and visualization of the arcades models. In addition, the paper aims to describe a method for the semantic studying of the porticoes architecture and the segmentation of the models. The goal is also to establish an integrated approach to the semantic cataloguing of the Bologna arcades based on historical, material, formal, dimensional and theoretical data, and to make this information easily readable and communicable

Real-time PCR-based detection of <em>Coxiella burneti</em>i in cheeses

International audienceIn this study, the presence of Coxiella burnetii (Cb) in cheese produced in Southern Italy from milk of cow, buffalo, and small ruminants has been evaluated. Two tests based on real-time PCR assay targeting CB IS1111 element were performed. First an assay based on the use of Taq-Man probe was performed to screen the samples. The positive samples were confirmed using both a SyBr Green test and the evaluation of the melting temperature of the amplicons. In addition, all cheese samples were also tested to determine the milk species utilized (Regulation EC 273/2008). The samples of cheese produced with a milk mix from different species were not included into the study. A total of 169 cheese samples were tested, and the obtained results showed an overall prevalence of Cb of 21.3 % with variation between species. A positivity rate of 39 % was observed in cow's cheese while Cb DNA was detected in 26 % of cheese samples made from small ruminants' milk. However, the bacterium was found only in 6.9 % of buffalo's cheese samples. A direct association between prevalence and milk used for the production was highlighted (chi (2) = 19.12). The statistical analysis of the prevalence in the samples from cattle and small ruminants compared with those from buffalo shows an OR of 8.4 and 4.9, respectively