ROLE OF SigE IN M.TUBERCULOSIS DRUG SUSCEPTIBILITY AND PERSISTENCE

M.tuberculosis (Mtb) is one of the most important pathogens that infect humans and it is the causative agent of tuberculosis (TB), a disease that dates back to ancient times. The World Health Organization (WHO) estimates that more than one third of the total whole population is infected with Mtb and each year about 1,5 millions people die from tuberculosis. Two of the main problems in M. tuberculosis control are the lengthy treatment and the enormous reservoir of latent carriers. A common explanation for the need of lengthy treatment is that all or part of the population enters a non-replicating persistent state characterized by some degree of dormancy. These are called “dormant” or “persistent” cells. This phenomenon, whose physiology is not well known, is very important for the treatment of infections, given the fact that dormant cells are resistant to many drugs. The aim of this study was to find new potential molecular targets that can be used to enhance the effectiveness of traditional antibacterial drugs, in order to develop new therapies effective against this population of non-replicating cells. Sigma factors (σ) regulate gene expression by binding to the RNA polymerase core enzyme and they could be important targets of new therapeutic approaches in the future, as some evidences recently showed they may play an essential role during Mtb persistence. In this work, we focused on one of these sigma factors, SigE, that was previously described to have a role in response to the different types of stresses bacteria encounter during infection, such as heat shock, surface and oxidative stresses (Manganelli et al., 2001). Using a sigE null mutant and through a series of different molecular and phenotypic investigations, we demonstrated how SigE plays a crucial role in response to stresses caused by different classes of antimicrobials. Furthermore, we observed a strong decrease in persister cells production when the sigE mutant was exposed to high concentrations of antibiotics. Finally, we tested other sigma mutants, to investigate if such a feature was shared across sigma factors. Although we demonstrated sigB (which expression is controlled by sigE under stress conditions) involvement in persisters production, the vast majority of the features we described in this work were unique of the SigE sigma factor. To conclude, with this work we were able to demonstrate how SigE may be a valid molecular target to develop new effective therapies against M.tuberculosis infections

Norma e Forma in Architettura: Effetti Distorsivi e Modelli Normativi

The morphological consequences of architectural rules and regulations have an extremely relevant impact in the determination of both architectural and urban quality. Despite that, the relationship between the normative domain and architectural practice is often overlooked, and current scientific works tend to (1) concentrate on the political, the social, or the historical dimensions of architectural normativity and (2) elaborate on norms as external to the design process. This research tackles the norm-form relationship with two aims: the first is to elucidate the role of rules in determining architectural form, as a part of the design process, rather than an external constraint. Rules that have an impact on the design process can be considered as design acts, and their agency can be judged on the basis of their contribution to design quality. The second aim is to develop an understanding of the normative traits of architectural practice, by delving, through historical analyses, in the ‘modes of transmission’ of normativity inside the discipline—i.e., how architects elaborate, communicate and implement the normative process as a specific part of the project itself. Architects use norms as part of the design process, which is, in turn, inherently normative. To this end, the first part of the thesis elaborates on the theoretical framework in which the question can be addressed. Drawing on Choay’s work, the twofold foundation of architecture as a discipline, based on one side on Rules—notably with Vitruvius’ and Alberti’s works— and on the other on drawn or built Models, is investigated. Architectural normativity, namely the manifold manifestations of normativity along the process of production of space, is questioned, to build, through the use of instruments pertaining to philosophy of law and social ontology, a taxonomy of the normative ideas underlying a variety of architectural phenomena. The second part of the thesis is dedicated to the interactions between architecture and the domain of state-enforced norms, to define the ‘perverse effects’ of existing norms in the Italian normative framework, namely effects that are neither expected nor intended, and whose formal consequences, although derived from deliberate decisions taken during the design process, is distant from the norms’ telos. The third part of the thesis consists of three in-depth case studies that serve the scope to investigate and clarify the relationship between architectural practice and rules. Drawing on the notion normative model —namely a built or designed architecture invested with deontic value, explored and defined in the first part— the thesis delves into the idea that architectural artefacts can carry a deontic meaning. It shows how it is possible to conceive, within an adequate normative framework, an effective drawn or built normative artefact that is capable of solving the aporias investigated in the second part of the thesis. In the three case studies discussed, the verbal regulation acts as a reinforcement vis-à-vis the normative models, which in turn express a series of ideas that can be declined in the design process flexibly and efficiently. The work concludes that the complex relationship between architecture and normativity is determined on one side by its historical development, in particular at the dawn of the print age, where architectural drawings drastically replaced the verbal discourse as a vector of architectural information, and on the other side by the crystallisation occurred during the rise of urbanism, that articulated regulation in its current, parametrical form. While rules and regulations pertaining to the architectural realm must be intended as part of the discipline, architecture itself can contribute to the development of a more articulated and effective regulation through the exploration of the project as a normative tool

Architectural AI: urban artificial intelligence in architecture and design

This chapter investigates the impact of artificial intelligence on contemporary cities through the lens of architectural and urban design. It explores design computing approaches where computers characterise the production and management of design. These include Artificial Intelligence (AI), Machine Learning (ML) as a subset of AI, and, in general terms, generative approaches to urban design where AI components are employed to create spatial configurations. We look at these systems as invisible forces that have significant consequences for both the built environment and people living in cities, providing examples and considerations of how intelligent systems and designers are reshaping cities today through a new form of agency. We present two intentionally polarised paradigms that underpin the idea of authorship in the design process and the extent to which designers (or machines) are in control of the design process and final outcomes. These are the digital demiurge, where designers have full control of their project and, contra, the black box, where AI determines the final design outcome in an opaque and often inscrutable way

Exports and Productivity: Comparable Evidence for 14 Countries

We use comparable micro level panel data for 14 countries and a set of identically specified empirical models to investigate the relationship between exports and productivity. Our overall results are in line with the big picture that is by now familiar from the literature: Exporters are more productive than non-exporters when observed and unobserved heterogeneity are controlled for, and these exporter productivity premia tend to increase with the share of exports in total sales; there is strong evidence in favour of self-selection of more productive firms into export markets, but nearly no evidence in favour of the learning-by-exporting hypothesis. We document that the exporter premia differ considerably across countries in identically specified empirical models. In a meta-analysis of our results we find that countries that are more open and have more effective government report higher productivity premia. However, the level of development per se does not appear to be an explanation for the observed cross-country differences.exports; productivity; micro data; international comparison

Single cell analysis of M. tuberculosis phenotype and macrophage lineages in the infected lung

In this study, we detail a novel approach that combines bacterial fitness fluorescent reporter strains with scRNA-seq to simultaneously acquire the host transcriptome, surface marker expression, and bacterial phenotype for each infected cell. This approach facilitates the dissection of the functional heterogeneity of M. tuberculosis-infected alveolar (AMs) and interstitial macrophages (IMs) in vivo. We identify clusters of pro-inflammatory AMs associated with stressed bacteria, in addition to three different populations of IMs with heterogeneous bacterial phenotypes. Finally, we show that the main macrophage populations in the lung are epigenetically constrained in their response to infection, while inter-species comparison reveals that most AMs subsets are conserved between mice and humans. This conceptual approach is readily transferable to other infectious disease agents with the potential for an increased understanding of the roles that different host cell populations play during the course of an infection

ROLE OF SigE IN M.TUBERCULOSIS DRUG SUSCEPTIBILITY AND PERSISTENCE

M.tuberculosis (Mtb) is one of the most important pathogens that infect humans and it is the causative agent of tuberculosis (TB), a disease that dates back to ancient times. The World Health Organization (WHO) estimates that more than one third of the total whole population is infected with Mtb and each year about 1,5 millions people die from tuberculosis. Two of the main problems in M. tuberculosis control are the lengthy treatment and the enormous reservoir of latent carriers. A common explanation for the need of lengthy treatment is that all or part of the population enters a non-replicating persistent state characterized by some degree of dormancy. These are called “dormant” or “persistent” cells. This phenomenon, whose physiology is not well known, is very important for the treatment of infections, given the fact that dormant cells are resistant to many drugs. The aim of this study was to find new potential molecular targets that can be used to enhance the effectiveness of traditional antibacterial drugs, in order to develop new therapies effective against this population of non-replicating cells. Sigma factors (σ) regulate gene expression by binding to the RNA polymerase core enzyme and they could be important targets of new therapeutic approaches in the future, as some evidences recently showed they may play an essential role during Mtb persistence. In this work, we focused on one of these sigma factors, SigE, that was previously described to have a role in response to the different types of stresses bacteria encounter during infection, such as heat shock, surface and oxidative stresses (Manganelli et al., 2001). Using a sigE null mutant and through a series of different molecular and phenotypic investigations, we demonstrated how SigE plays a crucial role in response to stresses caused by different classes of antimicrobials. Furthermore, we observed a strong decrease in persister cells production when the sigE mutant was exposed to high concentrations of antibiotics. Finally, we tested other sigma mutants, to investigate if such a feature was shared across sigma factors. Although we demonstrated sigB (which expression is controlled by sigE under stress conditions) involvement in persisters production, the vast majority of the features we described in this work were unique of the SigE sigma factor. To conclude, with this work we were able to demonstrate how SigE may be a valid molecular target to develop new effective therapies against M.tuberculosis infections.M.tuberculosis (Mtb) è uno dei patogeni più importanti che infettano gli essere umani ed è l’agente eziologico della tubercolosi (TB), una malattia che risale a tempi antichi. L’Organizzazione Mondiale della Sanità (OMS) stima che più di un terzo dell’intera popolazione mondiale sia stata infettata da Mtb e che ogni anno circa 1,5 milioni di persone muoiano di tubercolosi. Due dei principali problemi nel controllo di questa malattia sono l’enorme serbatoio di portatori latenti e la lunghezza del trattamento terapeutico. Una spiegazione condivisa relativamente alla necessità di un trattamento terapeutico prolungato è che la totalità o una parte della popolazione batterica, nel corso di un’infezione, entri in uno stato non replicativo, caratterizzato da un certo grado di “dormienza”. Queste cellule quiescenti sono chiamate “persisters”. Questo fenomeno, la cui fisiologia non è ben nota, è molto importante per il trattamento delle infezione, in considerazione del fatto che le cellule dormienti sono tolleranti ad alte concentrazioni di molti farmaci e perciò non vengono da essi uccise. Lo scopo di questo studio è stato pertanto quello di trovare nuovi potenziali bersagli molecolari che possano essere utilizzati per migliorare l’efficacia dei trattamenti terapeutici tradizionali, al fine di sviluppare nuove terapie efficaci contro questa popolazione di cellule persistenti. I fattori sigma (σ) regolano l’espressione genica legandosi all’apoproteina polimerasica e, in futuro, potrebbero essere importanti bersagli molecolari di nuovi approcci terapeutici, in quanto alcuni recenti studi hanno dimostrato come essi potrebbero avere un ruolo chiave nel fenomeno della persistenza di M.tuberculosis. In questo lavoro ci siamo concentrati su uno di questi fattori sigma in particolare, SigE, che era stato descritto in precedenza nel giocare un ruolo di primaria importanza nella risposta ai diversi tipi di stress che Mtb incontra durante un’infezione, come shock termico, stress di superficie e ossidativo. (Manganelli et al., 2001). Utilizzando un mutante di delezione per sigE e, attraverso una serie di indagini molecolari e fenotipiche, siamo stati in grado di dimostrare come SigE rivesta un ruolo cruciale nella risposta ai diversi tipi di stress causati dall’esposizione a differenti classi di farmaci antibatterici. Inoltre, abbiamo osservato una forte riduzione nella produzione di cellule “persister” quando il mutante sigE è stato esposto ad elevate concentrazioni di farmaci antimicrobici. Infine, per verificare se queste caratteristiche fossero condivise tra i fattori sigma, abbiamo testato altri mutanti per differenti fattori sigma. Nonostante siamo stati in grado di dimostrare che anche sigB (la cui espressione è controllata da sigE in condizioni di stress) sia coinvolto nella produzione di cellule persistenti, tuttavia la maggior parte delle caratteristiche molecolari e fenotipiche che abbiamo descritto in questo lavoro sono attribuibili al solo fattore SigE. Per concludere, con questo lavoro siamo stati in grado di dimostrare come SigE possa essere un valido bersaglio molecolare per lo sviluppo di nuove terapie efficaci contro le infezioni causate da M.tuberculosis

Cultural warehouses and the new industrial paradigm

This article depicts how different design strategies can be implemented in the conversion of an industrial building to other functions after it has ceased its activities. To this end, four contemporary post-industrial conversion projects are analysed, and different stances are described in relation to three aspects. The first is the spatial relationship between the old industrial buildings and the new elements needed for their ‘adaptive reuse’, whether one is encased into the other or they are mutually intersected. The second is the interaction between the different codes of existing and new: for instance, what is often a stark monumentality vis-à-vis to new outlandish hi-tech additions. The third aspect describes how the inevitable frictions between the old and the new are exhibited, hidden or neglected. The four projects presented here offer a set of different approaches that relate to a subtler understanding of the life cycle of urban industrial complexes and their transition. These namely stem from places for the production or transformation of material goods; hence, they are organized around a logical series of repetitive activities that takes place in a rigid spatial dimension, to places of cultural consumption, social interaction and business fostering which are, in contrast, subject to extemporary actions and unstable configurations. In short, they represent the economic transition from the material to the immaterial, from the hardware —structural, strong organization— to the software —light, liquid and unstable

Tassonomia materializzata: breve storia dello spazio della classificazione

L’erbario, nell’uso comune della parola, indica la collezione di piante essiccate, incollate a dei fogli ed etichettate per scopi di conoscenza e classificazione. La sua origine storica è situata nell’Italia rinascimentale, quando il medico e studioso Luca Ghini fonda il suo “hortus siccus” la prima collezione sistematica di specie conosciuta. Questo breve saggio espone un quadro delle sue origini e la strada verso l’emancipazione della tassonomia dai vincoli spaziali, collegandolo al fenomeno più generale degli spazi per la classificazione e gli edifici per la raccolta e l’accesso alla conoscenza: la ‘biblioteca’, ‘l’archivio’ e il ‘museo’

Taxononmy embodied: a brief history of classification spaces

In its commonplace meaning, the Herbarium is a collection of dried and labelled plants assembled for purposes of knowledge and classification. Its historic origins are set in late Renaissance Italy when physician and scholar Luca Ghini began to establish the first known “hortus siccus” (dried garden) as a systematic collection of known species. This brief essay provides an insight into the origins of the Herbarium and the road to the emancipation of taxonomy from spatial constraints, relating it to places of classification, storage and access to knowledge: the library, the archive and the museum