LISA: Mars and the limits of life

We describe the results of the first tests made on LISA, a simulator of planetary environments designed and built in Padua, dedicated to the study of the limit of bacterial life on the planet Mars. Tests on the cryogenic circuit, on the UV illumination and on bacterial coltures at room temperature that shall be used as references are described.Comment: 4 pages, 3 figures. Mem. SAIt, in pres

Prognostic Role of Bacterial and Fungal Infections in Patients with Liver Cirrhosis with and without Acute-on-Chronic Liver Failure: A Prospective 2-Center Study

Background. Bacterial and fungal infections (BFIs) are frequent in patients with cirrhosis and often trigger acute-on-chronic liver failure (ACLF). This prospective observational study aims to describe the interactions between BFI and ACLF in terms of mortality and related risk factors. Methods. We performed a 2-center prospective observational study enrolling hospitalized patients with cirrhosis admitted for acute decompensation. Data were recorded at admission and during hospitalization. Survival was recorded up to 1 year. Results. Among the 516 patients enrolled, 108 (21%) were infected at admission, while an additional 61 patients (12%) developed an infection during hospital stay. In the absence of ACLF, the 1-year mortality rate of patients with BFI did not differ from that of patients without BFI (33% vs 31%; P = .553). In contrast, those with ACLF triggered or complicated by BFI had a significantly higher mortality rate than those who remained free from BFI (75% vs 54%; P = .011). Competing risk analysis showed that the negative impact of ACLF-related BFI on long-term prognosis was independent from Model for End-stage Liver Disease (MELD) incorporating serum sodium concentration score, comorbidity, and basal C-reactive protein level. Finally, multivariable logistic regression showed that higher MELD score (P < .001), QuickSOFA score ≥2 points (P = .007), and secondary bloodstream (P = .022) and multidrug-resistant pathogen isolation (P = .030) were independently associated with ACLF in patients with BFI. Conclusions. This large prospective study indicated that the adverse impact of BFI on long-term survival in decompensated cirrhosis is not universal but is limited to those patients who also develop ACLF. Both disease severity and microbiological factors predispose infected decompensated patients to ACLF

Applied live art : co-authorship in socially engaged and site-responsive performance practice

This thesis looks at the ways in which performance can integrate participants and local context into the development of new devised work. This practice-led research is based on a methodology that grew out of three performance case studies completed in diverse international settings with a varied range of participants. The case studies are: Napoli Scorticata completed in 2007 in Naples, Italy; Youth Visions, completed in 2008 in Northeastern Ghana, West Africa; Triangulated City, completed in 2009 in Beirut, Lebanon. Within these diverse contexts the research questions the role of authorship when working in socially engaged practice, focusing on how practitioners can shift the focus from the artist to the body politic. Merging social engagement with a site-responsive approach, the research proposes that the artistic medium is the social system and as such argues that the modes of employment require a focus of appreciation on the generative process, context and product combined. The research is presented in two parts. Part I is an interactive DVD with images of the development process and final presentations as well as a video of each performance work. Part II is a written thesis that explores the modes of engagement, outlines the methods of development and structures a general working methodology that can be referenced by other performance practitioners. The thesis proposes Applied Live Art as a term to describe practices that include a hybrid of time-based media options, which include a social component as their primary focus. The research outcomes conclude with an analysis of place making and its importance when working with both site and society.EThOS - Electronic Theses Online ServiceBritish Council Middle EastBritish Council ItalyRoyal Holloway Drama DepartmentUniversity of London Central Research FundPresident's Emergency Fund for AIDS ReliefTheatre Communications GroupGBUnited Kingdo

Inductive Plasma Thruster (IPT) design for an Atmosphere-Breathing Electric Propulsion System (ABEP)

Challenging space missions include those at very low altitudes, where the atmosphere is source of aerodynamic drag on the spacecraft, therefore an efficient propulsion system is required to extend the mission lifetime. One solution is Atmosphere-Breathing Electric Propulsion (ABEP). It collects atmospheric particles to use as propellant for an electric thruster. This would minimize the requirement of limited propellant availability. The system could be applied to any planet with atmosphere, enabling new mission at these altitude ranges for continuous orbiting. Challenging is also the presence of reactive chemical species, such as atomic oxygen in Earth orbit. Such components are erosion source of (not only) propulsion system components, i.e. acceleration grids, electrodes, and discharge channels of conventional EP systems (RIT and HET). IRS is developing within the DISCOVERER project an intake and a thruster for an ABEP system. This paper deals with the design and first operation of the inductive plasma thruster (IPT) developed at IRS. The paper describes its design aided by numerical tools such as HELIC and ADAMANT. Such a device is based on RF electrodeless discharge aided by externally applied static magnetic field. The IPT is composed by a movable injector, to variate the discharge channel length, and a movable electromagnet to variate position and intensity of the magnetic field. By changing these parameters along with a novel antenna design for electric propulsion, the aim is to achieve the highest efficiency for the ionization stage by enabling the formation of helicon-based discharge. Finally, the designed IPT is presented and the feature of the birdcage antenna highlighted

An estimation method for the Shock Response Spectrum propagating into plates subjected to hypervelocity impact

The present work regards the prevision through Finite Element Analysis (FEA) codes of the Shock Response Spectrum (SRS) levels on thin plates subjected to Hypervelocity Impact (HVI). An experimental campaign has been performed to measure the accelerations caused by HVI and a method minimizing the number of simulations needed to predict the experimental curve has been sought. The method reconstructs an equivalent force impulse that is used as input for the model of the plate. The shape and amplitude are selected to numerically match the SRS curve obtained by experiments. The comparison between the experimental and the numerical SRS remains within an uncertainty band of \ub13 dB, thus sensibly smaller than the usual one for shock impacts (often \ub16 dB). Additionally, the equivalent force peak can be used as an input to evaluate acceleration in other points of the structure or to perform analyses using different models