Análisis ambiental del partido de La Plata

Este estudio brinda información sobre, clima, infraestructura de comunicaciones, topografía, hidrología superficial, geomorfología, características de los suelos y su aptitud agropecuaria-forestal e ingenieril, degradación de suelos por actividades extractivas, uso actual de la tierra, riesgos geológicos y planeamiento ambiental del partido de La Plata. Tal información esta destinada a técnicos del municipio, asi como a entes provinciales y a la actividad privada, aportando ademas a la difusión del conocimiento en diferentes niveles del sistema educativo

A method for dynamic subtraction MR imaging of the liver

BACKGROUND: Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR) volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time. METHODS: Nineteen consecutive patients (median age 45 years; range 37–67) were evaluated by VIBE T1-weighted sequences (TR 5.2 ms, TE 2.6 ms, flip angle 20°, slice thickness 1.5 mm) acquired before and 45s after contrast injection. Acquisition parameters were optimized for best portal system enhancement. Pre and post-contrast liver volumes were realigned using our 3D registration method which combines: (a) rigid 3D translation using maximization of normalized mutual information (NMI), and (b) fast 2D non-rigid registration which employs a complex discrete wavelet transform algorithm to maximize pixel phase correlation and perform multiresolution analysis. Registration performance was assessed quantitatively by NMI. RESULTS: The new registration procedure was able to realign liver structures in all 19 patients. NMI increased by about 8% after rigid registration (native vs. rigid registration 0.073 ± 0.031 vs. 0.078 ± 0.031, n.s., paired t-test) and by a further 23% (0.096 ± 0.035 vs. 0.078 ± 0.031, p < 0.001, paired t-test) after non-rigid realignment. The overall average NMI increase was 31%. CONCLUSION: This new method for realigning dynamic contrast-enhanced 3D MR volumes of liver leads to subtraction images that enhance diagnostic possibilities for liver lesions

Integrating human behaviour and building vulnerability for the assessment and mitigation of seismic risk in historic centres: Proposal of a holistic human-centred simulation-based approach

The complexity of historic centres implies that risk assessment in those areas should be based on joint analyses of the characteristics of the built environment and the population's features, exposure and interaction with the surrounding environment. Such a holistic approach is urgently needed to evaluate the impact of mitigation strategies, especially in sudden onset disasters, and, mainly, earthquakes. In fact, the effectiveness of retrofitting interventions and emergency management strategies on the safety level depends greatly on such interactions, also in relation to the path network features. This work proposes a PDCA-based methodology for earthquake risk assessment which innovatively combines built environment damage assessment with a simulation of human evacuation behaviour so as to identify potentially inaccessible evacuation paths and urban areas, define related paths/areas safety levels and evaluate the impact of proposed retrofitting and management strategies on the population's safety in an emergency. To this end, a validated seismic vulnerability index method for masonry façade walls is combined with empirical damage assessment correlations (debris depth estimation in outdoor spaces) to create post-earthquake damage scenarios. Then, these are used as input data for evacuation process assessment through an existing earthquake pedestrians' evacuation simulator. Paths and safe areas risk indices are proposed to evaluate the main behavioural issues in emergency conditions. Finally, different solutions aimed at improving evacuation safety (i.e. emergency plans, rescuers' access strategies and retrofitting of buildings) are proposed and discussed for a significant case study, the historic centre of Coimbra, Portugal

ESPOSIZIONE PROFESSIONALE AL RISCHIO BIOLOGICO IN AMBITO OSPEDALIERO: PROPOSTA DI UN METODO DI VALUTAZIONE

La valutazione del rischio biologico è regolamentata dai Titoli X e X-bis (D.Lgs.81/08). Stimare il rischio consente di attuare idonee misure preventive nei confronti del lavoratore. Lo scopo del lavoro è di elaborare un metodo valutativo del rischio biologico in ambito ospedaliero basato su un indice di rischio numerico che rispecchi l’effettiva variabilità di esposizione degli operatori. Il metodo proposto è basato su quello elaborato da INAIL per la valutazione del rischio biologico negli ambulatori “Prime cure”, riadattato alla complessità ospedaliera. Per ogni reparto sono stati definiti rilevanti i seguenti parametri: 1) Tipologia e quantità delle procedure a rischio eseguite; 2) Presenza di pazienti portatori di malattie trasmissibili; 3) Conoscenza delle idonee procedure atte a garantire un’adeguata prevenzione; 4) Utilizzo di DPI e formazione degli operatori. E’ stato somministrato un questionario ai 71 reparti degli Ospedali Riuniti di Ancona. La rielaborazione delle risposte ottenute è stata integrata con dati provenienti dalle notifiche per malattie trasmissibili e dalle denunce di infortunio professionale. La corretta pesatura di taluni parametri ha contribuito al calcolo dell’indice di rischio finale. Si evincono differenze significative per ciascun reparto. Le aree con maggior numero di manovre a rischio sono le stesse che conoscono ed attuano maggiormente adeguate procedure preventive. Le terapie intensive, pur svolgendo attività ad elevata potenzialità di contaminazione, sono quelle che meglio conoscono idonee misure preventive. I reparti in cui l’applicazione delle procedure risulta più critica sono quelli dell’area dell’emergenza, presumibilmente a causa della tipologia di lavoro più frenetica e meno programmabile, e quella dei servizi, probabilmente per una diminuita percezione del rischio. Lo studio svolto ha permesso di elaborare un’indice numerico volto a stimare il rischio di subire una infezione oc- cupazionale da parte degli operatori sanitari. L’analisi dei risultati ottenuti ha evidenziato un livello di rischio biologico “minimo” comune a tutte le aree. Il ri- schio cresce in funzione di tipologia/quantità di manovre invasive eseguite, nonché della presenza di pazienti por- tatori di malattie trasmissibili, ma può essere abbattuto mediante la corretta applicazione di procedure preventive

Lung damage in paraquat poisoning and hyperbaric oxygen exposure: superoxide-mediated inhibition of phospholipase A2.

Paraquat poisoning and hyperbaric oxygen exposure are well established models of oxidative stress in lung. The aim of this study was focused on the contribution of oxygen free radicals and other cytotoxic species, such as lipid hydroperoxides, to the overall toxicity. Adult Wistar rats were injected with paraquat (30 or 60 mg/kg b.w.) or exposed to hyperbaric oxygen (0.2 MPa), and several parameters of lung damage were measured. Both treatments resulted in increased spontaneous lung chemiluminescence, number of lung PMN, malondialdehyde content, lung edema, and pleural liquid. Of note, spontaneous lung chemiluminescence, used to monitor the steady-state concentration of oxygen free radicals in vivo, did not increase significantly after either treatment. The increase in spontaneous lung chemiluminescence started after PMN migration, being both maxima separated by a delay time of 4-6 h. After PMN migrated and became activated in the lung, the survival of the animals started to decline. Thus, PMN can be considered as additional sources of oxygen free radicals supported by the subsequent increase in chemiluminescence. Their role in lung damage was evidenced by the increase in lung edema, augmented pleural liquid, and decreased survival after PMN migration. Lipid hydroperoxide concentration in lung membranes was also increased after either treatment. This increased concentration may be a consequence of an increased rate of lipid peroxidation, initiated by oxidative stress on lipid membranes, or by an inhibition of their catabolism. Ester lipid hydroperoxides normally produced in membranes cannot be catabolized directly by the glutathione peroxidase-reductase system unless phospholipase A2 catalyses the release of free lipid hydroperoxides. In both experimental models, phospholipase A2 activity was decreased to almost negligible values. Betamethasone (1 mg/ml; IV) administered to the rats 3 h before paraquat injection accelerated the decrease in survival and phospholipase A2 inactivation. Inactivation of phospholipase A2, detected in paraquat or oxygen exposed rats, could be attributed to a O2(.-)-driven Fenton reaction. However, phospholipase A2 inactivation by betamethasone pretreatment may be attributed to the presence of lipocortin, a corticosteroid-inducible factor and inhibitor of phospholipase A2. Besides the mechanism underlying the inactivation of phospholipase A2, the increase in lipid hydroperoxides may indicate their role as long-lived cytotoxic species that contribute to the damage already initiated by oxidative stress. Indeed, lipid hydroperoxides are very well known modifiers of membrane physical properties

Low-Coherence Interferometry Optical Sensor for the Characterization of Deposited Thin Film

OSA Conference: Optical Sensors (Sensors) Karlsruhe, Germany June 21, 2010 Sensor Systems II (SWD) http://www.opticsinfobase.org/abstract.cfm?URI=Sensors-2010-SWD

OPTICAL RANGING IN ENDOSCOPY: TOWARDS QUANTITATIVE IMAGING

Nowadays endoscopic analysis is limited to a direct and qualitative view of internal anatomy. On the other hand, the measurement of the actual size of anatomical objects could be a powerful instrument both in research and in clinical survey. For instance, an important application could be monitoring lesion size, both during diagnosis and in follow-up. The foremost obstacle to quantitative imaging is the incapability of measuring the distance between the endoscopic probe and the anatomical object under examination, since the dimension of the object in the image depends on that distance. This problem has not been solved yet in a satisfactory way. In this Chapter we describe our work to address this problem by means of an optical measurement of the distance between the endoscope distal tip and the anatomical wall. We make use of Fiber Optics Low Coherence Interferometry to realize an absolute distance sensor compatible with endoscope technology. The result is a system integrating a clinical endoscope and an optical distance sensor, equipped with a software that allows an user to acquire an endoscopic image, select a region of interest, and obtain its quantitative measure