Stima del diametro di un grafo con il framework Apache Spark(TM)

Il tema centrale di questo lavoro è l’analisi e l’implementazione dell’algoritmo HADI per la stima del diametro e del diametro effettivo dei grafi. Per migliorare le prestazioni di HADI faremo uso di Spark, un nuovo framework per il calcolo distribuito che si presenta come molto più efficiente rispetto ad Hadoop. Dalla nuova implementazione di HADI, abbiamo ottenuto un incremento delle prestazioni fino a un ordine di grandezza rispetto all'algoritmo originaleope

Assessment of Fibrinolysis in Sepsis Patients with Urokinase Modified Thromboelastography

INTRODUCTION: Impairment of fibrinolysis during sepsis is associated with worse outcome. Early identification of this condition could be of interest. The aim of this study was to evaluate whether a modified point-of-care viscoelastic hemostatic assay can detect sepsis-induced impairment of fibrinolysis and to correlate impaired fibrinolysis with morbidity and mortality. METHODS: This single center observational prospective pilot study was performed in an adult Intensive Care Unit (ICU) of a tertiary academic hospital. Forty consecutive patients admitted to the ICU with severe sepsis or septic shock were included. Forty healthy individuals served as controls. We modified conventional kaolin activated thromboelastography (TEG) adding urokinase to improve assessment of fibrinolysis in real time (UK-TEG). TEG, UK-TEG, plasminogen activator inhibitor (PAI)-1, thrombin-activatable fibrinolysis inhibitor (TAFI), d-dimer, DIC scores and morbidity (rated with the SOFA score) were measured upon ICU admission. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of mortality at ICU discharge. RESULTS: UK-TEG revealed a greater impairment of fibrinolysis in sepsis patients compared to healthy individuals confirmed by PAI-1. TAFI was not different between sepsis patients and healthy individuals. 18/40 sepsis patients had fibrinolysis impaired according to UK-TEG and showed higher SOFA score (8 (6-13) vs 5 (4-7), p = 0.03), higher mortality (39% vs 5%, p = 0.01) and greater markers of cellular damage (lactate levels, LDH and bilirubin). Mortality at ICU discharge was predicted by the degree of fibrinolysis impairment measured by UK-TEG Ly30 (%) parameter (OR 0.95, 95% CI 0.93-0.98, p = 0.003). CONCLUSIONS: Sepsis-induced impairment of fibrinolysis detected at UK-TEG was associated with increased markers of cellular damage, morbidity and mortality

Procoagulatory state in inflammatory bowel diseases is promoted by impaired intestinal barrier function

Inflammatory and immune mediated disorders are risk factors for arterial and venous thromboembolism. Inflammatory bowel diseases (IBD) confer an even greater risk of thromboembolic events than other inflammatory conditions. It has been shown that IBD patients display defective intestinal barrier functions. Thus, pathogen-associated molecular patterns (PAMPs) coming from the intestinal bacterial burden might reach systemic circulation and activate innate immunity receptors on endothelial cells and platelets, promoting a procoagulative state. Aim of the study was to test this hypothesis, correlating the presence of circulating PAMPs with the activation of innate immune system and the activation of the coagulatory cascade in IBD patients. Specifically, we studied lipopolysaccharide (LPS), Toll-like receptor (TLR) 2, TLR4, and markers of activated coagulation (i.e., D-Dimer and prothrombin fragment F1 + 2) in the serum and plasma of IBD patients. We found that LPS levels are increased in IBD and correlate with TLR4 concentrations; although a mild correlation between LPS and CRP levels was detected, clinical disease activity does not appear to influence circulating LPS. Instead, serum LPS correlates with both D-Dimer and F1 + 2 measurements. Taken together, our data support the role of an impairment of intestinal barrier in triggering the activation of the coagulatory cascade in IBD

Implementation of the evidence for the improvement of nursing care to the critical patient's family: a participatory action research

Background: There are many descriptive studies regarding the needs of the family, as well as those regarding nursing care aimed directly at family members. However, there is no widespread application of such evidence in clinical practice. There has also been no analysis made of the evolution of patterns of knowing during the act of improving clinical practice. Therefore, the purpose of the study is to understand the change process aimed at improving care to critical patient's families, and to explore the evolution of patterns of knowing that nurses use in this process. Methods: Qualitative study with a Participatory Action Research method, in accordance with the Kemmis and McTaggart model. In this model, nurses can observe their practice, reflect upon it and compare it with scientific evidence, as well as define, deploy and evaluate improvement strategies adapted to the context. Simultaneously, the process of empowerment derived from the Participatory Action Research allows for the identification of patterns of knowing and their development over time. The research will take place in the Intensive Care Units of a tertiary hospital. The participants will be nurses who are part of the regular workforce of these units, with more than five years of experience in critical patients, and who are motivated to consider and critique their practice. Data collection will take place through participant observation, multi-level discussion group meetings and documentary analysis. A content analysis will be carried out, following a process of codification and categorisation, with the help of Nvivo10. The approval date and the beginning of the funding were December 2012 and 2013, respectively. Discussion: The definition, introduction and evaluation of care strategies for family members will allow for their real and immediate implementation in practice. The study of the patterns of knowing in the Participatory Action Research will be part of the theoretical and practical feedback process of a professional discipline. Also, the identification of the construction and evolution of knowledge will provide decision elements to managers and academics when choosing strategies for increased quality

Teoria e pratica della compressione dati senza perdita. L'esempio dell'algoritmo DEFLATE

La compressione dati senza perdita (loseless) è la compressione tale da ottenere la stessa identica informazione dopo la compressione/decompressione dei dati. Le informazioni quali il codice di un programma, testo, documenti, database e file di sistema devono rimanere integri in ogni parte se li si vuole utilizzare. Questa modalità di compressione comporta dei vincoli alla compressione stessa, come dimostrato dai risultati teorici che sono stati raggiunti nell'ultimo secolo. La tesi è una modesta (ma non banale) trattazione della codifica delle informazioni e della loro compressione: nel primo capitolo espongo alcuni limiti teorici alla codifica delle informazioni, mentre nel secondo capitolo descrivo brevemente l'algoritmo DEFLATE, il suo funzionamento e la strategia vincente che esso adotta per eseguire la compression

Stima del diametro di un grafo con il framework Apache Spark(TM)

Il tema centrale di questo lavoro è l’analisi e l’implementazione dell’algoritmo HADI per la stima del diametro e del diametro effettivo dei grafi. Per migliorare le prestazioni di HADI faremo uso di Spark, un nuovo framework per il calcolo distribuito che si presenta come molto più efficiente rispetto ad Hadoop. Dalla nuova implementazione di HADI, abbiamo ottenuto un incremento delle prestazioni fino a un ordine di grandezza rispetto all'algoritmo original