282 research outputs found
Sviluppo ed implementazione su DSP di un algoritmo per l'elaborazione in tempo reale di segnali eco, ad alta frequenza, per usi biomedici
Costituiscono l'oggetto di questa tesi, lo sviluppo e l'implementazione su DSP di un algoritmo per l'elaborazione di segnali eco, ad alta frequenza, per usi biomedici.
Il segnale acquisito nel monitoraggio tramite i sistemi ad alta frequenza presi in considerazione, come i sistemi radar Ultra Wide Band (UWB), riflette l'attività cardiaca e respiratoria; ci siamo proposti di estrarre dal segnale le due componenti ricavando la frequenza cardiaca e quella respiratoria.
Il monitoraggio delle funzioni vitali fornisce un importante contributo in diversi casi, come interventi chirurgici, monitoraggio domestico, monitoraggio Holter o monitoraggio di lavoratori a rischio permettendo un livello di assistenza al paziente più efficace. In tutti questi contesti è fondamentale la disponibilità di un dispositivo portatile, non ingombrante, che non renda difficoltosi i movimenti, che rilevi uno o più parametri indicatori della situazione che vogliamo scongiurare, che esegua misure non invasive e che lavori in tempo reale.
Sotto questi punti di vista le tecniche attuali di
indagine non invasiva sono poco efficienti rispetto alle potenzialità delle nuove tecniche emergenti, come i radar UWB applicati alla medicina che questa tesi prende in considerazione. Esistono infatti diversi studi che dimostrano la capacità degli UWB di rilevare in modo remoto la frequenza respiratoria e quella cardiaca usando delle tecniche radar ad impulso nella regione delle microonde.
Emerge quindi la necessità di disporre di un dispositivo che sia non invasivo e poco ingombrante ma anche dotato di un sistema di elaborazione in grado di effettuare analisi sui fenomeni biologici monitorati in tempo reale. E' per tale motivo che abbiamo scelto di implementare dei filtri e la trasformata di Fourier su un processore DSP (Digital Signal Processor), tramite il kit di sviluppo TMDS3200006711E. I filtri permettono di separare le componenti frequenziali dominanti fornendo due segnali che sono indice dell'attività cardiaca uno, e dell'attività respiratoria l'altro. Calcolando la trasformata di Fourier dei segnali abbiamo ricavato le frequenze di interesse come quelle rispetto alle quali le due trasformate di Fourier sono massime. Abbiamo inoltre fatto un confronto fra i possibili tipi di filtri (IIR e FIR) e metodi di progettazione digitali
An updating on Cryptosporidium parvum in the water buffalo
A cross-sectional survey of Cryptosporidium parvum infection in the water buffalo was carried out in central Italy. The survey was carried out on a sample of 90 farms, selected using a grid approach within a Geographical Information System, followed by proportional allocation. On each farm, faecal samples were collected from three to five asymptomatic buffalo calves, aged from 1 to 9 weeks (total number = 347). Each sample was tested for the presence of copro-antigens of C. parvum using a commercially available ELISA. Out of the 90 farms, 22 (24.4%) resulted positive. With respect to animals, out of the 347 faecal samples, 51 (14.7%) were found to have antigens of C. parvum. The results of the logistic regression model showed a positive association between the positivity to C. parvum and the high number of buffaloes on farms
Toxoplasma Gondii in animali da reddito e rischio per l'uomo tramite il consumo di carne
Toxoplasma gondii è un protozoo del phylum Apicomplexa, parassita di numerose specie animali e dell’uomo. Gli ospiti definitivi di T. gondii sono felidi domestici e selvatici, incluso il gatto domestico, i quali sono gli unici in grado di diffondere oocisti con le feci. Gli ospiti intermedi del protozoo comprendono numerose specie di mammiferi ed uccelli, incluso ovini, caprini, bovini, bufali, equini ed uomo. La toxoplasmosi è riconosciuta come una importante causa di infertilità negli ovini e caprini e, di conseguenza, è responsabile di significative perdite economiche nel settore ovino e caprini a livello mondiale. Inoltre, la carne ovina contaminata da T. gondii è considerata una rilevante fonte di infezione per l’uomo. La presente ricerca riassume le attuali conoscenze inerenti i fattori di rischio per toxoplasmosi negli animali da reddito e nell’uomo. Strumenti di indagine spaziale e un modello univariato di regressione sono stati utilizzati per creare mappe di rischio relative alla positività a T. gondii di ovini allevati in Campania e determinare fattori di rischio associati alla sieroprevalenza intra-allevamento del parassita. Il modello ha rivelato che “la tipologia di produzione” (latte o solo carne) era l’unica variabile indipendente associata alla maggiore sieroprevalenza nei confronti del parassita (P-value < 0.02). Nessuna altra variabile ambientale o di management è risultata significativa. Infine, una valutazione del rischio di toxoplasmosi associata al consumo di carne di maiale in Italia è stata proposta al fine di: 1) determinare i prodotti maggiormente a rischio in Italia; 2) individuare i principali fattori di rischio connessi all’esposizione al parassita; 3) evidenziare gli attuali “gaps” nella conoscenza di T. gondii quale agente di zoonosi
Ponti integrali: analisi statica e sismica
In questo elaborato si è inizialmente studiata la diffusione dei ponti integrali nel mondo, riassumendone vantaggi e problematiche. Viene riservato ampio spazio allo studio dei particolari costruttivi e ai limiti geoemtrici suggeriti nei vari paesi. Successivamente, utilizzando i dati relativi a tre ponti progettati con una soluzione Semi Integrale si sono svolte delle analisi parametriche al fine di capire quale sia il comportamento di questo tipo di ponti al variare di alcuni parametri significativi. Le analisi parametriche svolte sono sia di tipo statico che di tipo sismico e a tal proposito, viene effettuato un confronto tra le sollecitazioni negli elementi principali del ponte dovute ai carichi statici e quelle dovute al sisma, cercando di capire le principali differenze rispetto ai ponti tradizionali. Infine si è svolto un confronto tra la tipologia Semi Integrale e la tipologia Completamente Integrale andando a indagare i vantaggi relativi all'uso di entrambe le soluzioniope
Mapping, cluster detection and evaluation of risk factors of ovine toxoplasmosis in Southern Italy
Toxoplasmosis, an important cause of reproductive failure in sheep, is responsible for significant economic losses to the ovine industry worldwide. Moreover, ovine meat contaminated by the parasite Toxoplasma gondii is considered as a common source of infection for humans. The aim of this study was to develop point and risk profiling maps of T. gondii seroprevalence in sheep bred in Campania Region (Southern Italy) and analyse risk factors associated at the flock-level. We used serological data from a previous survey of 117 sheep flocks, while environmental and farm management information were obtained from an analysis based on geographical information systems and a questionnaire purveyance, respectively. An univariate Poisson regression model revealed that the type of farm production (milk and meat vs only meat) was the only independent variable associated with T. gondii positivity (P<0.02); the higher within-flock seroprevalence in milking herds suggests that milking practices might influence the spread of the infection on the farm. Neither environmental nor other management variables were significant. Since a majority of flocks were seasonally or permanently on pasture, the animals have a high exposure to infectious T. gondii oocysts, so the high within-flock seroprevalence might derive from this management factor. However, further studies are needed to better assess the actual epidemiological situation of toxoplasmosis in sheep and to clarify the factors that influence its presence and distribution
First studies on Giardia duodenalis in the water buffalo
A cross-sectional survey of Giardia duodenalis infection in the water buffalo was carried out in Central Italy. The survey was conducted on a sample of 90 farms, selected using a grid approach within a Geographical Information System, followed by proportional allocation. On each farm, faecal samples were collected from three to five asymptomatic buffalo calves, aged from 1 to 9 weeks (total number = 347). Each faecal sample was tested for the presence of copro-antigens of G. duodenalis using a commercially available ELISA. Out of the 90 farms, 27 (30.0%) resulted positive. With respect to animals, out of the 347 faecal samples, 63 (18.1%) were found to have antigens of G. duodenalis. The results of the logistic regression model showed a positive association between the positivity to G. duodenalis and the presence of sheep on farm
Conducting an International, Exploratory Survey to Collect Data on Honey Bee Disease Management and Control
The Istituto Zooprofilattico Sperimentale del Lazio e della Toscana (IZSLT) and the International Federation of Beekeepers' Associations (Apimondia) set up a worldwide survey in 2015–2017 to gather information on beekeepers' perceptions concerning good beekeeping practices, the main honey bee diseases, and the technical assistance they receive. The on-line dissemination of the survey was facilitated by the "Technologies and Practices for Small Agricultural Producers" platform (TECA) of the Food and Agriculture Organization of the United Nations (FAO). In total, 248 questionnaires were received from the European region and the results are reported here. Varroosis remains the biggest concern and is the most important reason for beekeepers' use of veterinary medicines. However, a sustainable approach to managing Varroa was detected. American foulbrood (AFB) and European foulbrood (EFB) infections are mainly managed through the shook swarm technique or burning the hives. Concerning technical assistance for disease management, beekeepers were mainly supported by their associations or expert beekeepers. Relevant data were collected and analyzed but information from many low-income countries in Africa or Asia is still missing, and more efforts are needed to fill the knowledge gaps
Shape and construction of brick vaults. Criteria, methods and tools for a possible catalogue
The use of cloister vaults in the construction of noble buildings, as covering elements for square or rectangular rooms, is widespread and well-known. The geometric continuity at the intrados makes generally possible the execution all over the span of frescoes, stucco and decorations.
The construction of brick vaults, from the late Middle Age, was sped up by limiting the centering to the wooden planks arches that were instrumental in the profile determination.
Nowadays, the availability of several procedures, phases and tools for carrying out a survey allows to draw reliable assumptions about the construction methods and the execution time.
It is mandatory to determine the properties of the binders, the shape and dimensions of the bricks, and to carry out a comparison between the geometry of the intrados surface and the evidences emerging at the extrados. The support of the laser scanner technique allows to accurately identify the surface profile and thickness. All these indications, in turn, are useful, in view of an interpretation of the structural behavior, to identify weaknesses, and to highlight contributing factors of instability (if any).
In addition, Italian culture lacks systematic studies that indicate a reliable common pattern among the different types of vaults. Similar intrados shapes are often characterized by radically different patterns that are rarely taken into account from the structural point of view.
The culture of stereotomy, in France and Spain, takes this interpretation of vaults for granted, while more systematic studies, in German-speaking countries, offer a broad and solid framework.
The Italian technical literature was in Modern Age relatively scarce and showed limited attention to structural problems, and this fact contributes to widen this gap.
Providing a variety of accurate surveys, aware of the aforementioned framework and the related shortcomings, will enable to overcome them. As a matter of fact, an element like the vault characterizes the Italian built heritage, but in the structural analysis there is often an oversimplification of some geometrical properties, limited to hurriedly measure thicknesses and intrados profiles, something that may lead to wrong conclusions.
The paper focuses on a well-documented case, the Magio Grasselli palace in Cremona, where late medieval existing buildings were partially dismantled and modified in a modern aristocratic palace, designed by architect Francesco Pescaroli starting after 1658 until the end of the century. However, only the part of the building facing the main street and the part of the room overlooking the inner court were completed. The construction was resumed only after 1760: the wing facing the court and garden was completed, and all the rooms of the main floor, including the entrance hall, were covered with cloister vaults. Later on, the part of the building overlooking the main street was transformed. Here also, five rooms facing the street were vaulted, but only the central room, entirely painted by Giovanni Manfredini (1785), was completed, while three other unfinished rooms were subdivided in the Nineteenth century. The cloister vaults of two main rooms show different construction systems, although they were built almost at the same time. In the one overlooking the court, the bricks were laid on edge in concentric rows that seem parallel to the walls of the room, but are slightly arranged upwards. The irregularities are compensated by the longitudinal key joints. Wall-ribs systems at the extrados (the so-called Italian frenelli) connected to reinforcing arches, which could have served as base framework, contribute to the global stability of the structure. Thus, the vault seems to be constructed without continuous centering. Again, the large dimensions and the almost square shapes of the room overlooking the street suggest a construction through subsequent phases. Here the arches, visible from the extrados, were the centering outlining the profile of the vault, and enabled to build it without the support of planks.
In order to understand the similarities and differences, the construction techniques and the state of damage of the two halls vaults, an integrated survey using laser scanners, photogrammetry and thermographic investigations was carried out. Such a survey allowed understanding the vault morphology and the masonry pattern, highlighting certain critical aspects of the structural elements, the kind of instability and decay, and the crack patterns mechanisms.
More in detail, the three-dimensional model of the intrados of the hall, obtained from the laser scanner clouds, has been integrated with the three dimensional model of the masonry pattern, visible from the extrados, obtained from an elaboration of photogrammetric images. The current structure is a frame vault, characterized by two large and respectively transverse and longitudinal arches which divide the surface in nine squares and support thinner vaults, made of tiles (3-5 cm), widely used since the Sixteenth century.
The investigation of easily detectable extrados parts makes a deeper knowledge of such constructions possible: it allows a better interpretation of recurring situations, even more problematic to be detected. This interpretation, however, cannot be carried out without an accurate survey integrated by thermography that can be extensively used at the intrados surfaces.
In addition, the patient reconstruction and understanding of a constructive richness, made of recurrent elements and specific features, allow sketching a mixed pattern of workers and constructive knowledge. This process may result into current geographical updatable abaci, such as the French repertoires; from the point of view of innovation, it could lead to BIM libraries of vaulted elements that should be, however, not aimed at flattening and oversimplifying these valuable items to a unique parametric matrix, “copy-and-pasteable” at will, with mere changes of dimensions. Unfortunately, an oversimplification of complex elements (such as vaults) is the rule in the application of BIM to the cultural heritage. This oversimplification is the demonstration of incomplete knowledge and deviate interpretation of BIM that should be used, on the contrary, to better handle differences and peculiarities. Through the concept itself of instances consisting of unique and complex elements, “hic et nunc” to every object, the families are enriched; what is different is the point of view that should be aimed not at unifying, but at the comprehension and rendering of the acquired knowledge. As testified by some recent experiences, BIM models support this different approach to modeling, although still in a rather complex way (even if the rendering of a complex model is always complex).
The availability of a detailed three-dimensional model allows a backward knowledge of the construction technique, maybe not in its entirety, but sufficient enough to explain and highlight that the provision and use of centering in the constructive phase, as previously mentioned, “changes” the geometric shape by creating multiple variations.
The archival, metric and thermographic information concerning the Magio Grasselli palace are abundant and considerable, and are integrated with the plurality of data, essential to define an elevated standard of documentation, which allows to justify both detailed hypotheses on the construction techniques, and classification criteria. It is important, however, to subject the whole to a critical examination, in order to define principles effectively shared and aimed at building a reference system, whose absence was already pointed out
The risk of infection by African swine fever virus in European swine through boar movement and legal trade of pigs and pig meat
African swine fever (ASF) is currently spreading westwards throughout Europe and eastwards into China, with cases occurring in both wild boar and domestic pigs. A generic risk assessment framework is used to determine the probability of first infection with ASF virus (ASFV) at a fine spatial scale across European Union Member States. The framework aims to assist risk managers across Europe with their ASF surveillance and intervention activities. Performing the risk assessment at a fine spatial scale allows for hot-spot surveillance, which can aid risk managers by directing surveillance or intervention resources at those areas or pathways deemed most at risk, and hence enables prioritization of limited resources. We use 2018 cases of ASF to estimate prevalence of the disease in both wild boar and pig populations and compute the risk of initial infection for 2019 at a 100 km2 cell resolution via three potential pathways: legal trade in live pigs, natural movement of wild boar, and legal trade in pig meat products. We consider the number of pigs, boar and amount of pig meat entering our area of interest, the prevalence of the disease in the origin country, the probability of exposure of susceptible pigs or boar in the area of interest to introduced infected pigs, boar, or meat from an infected pig, and the probability of transmission to susceptible animals. We provide maps across Europe indicating regions at highest risk of initial infection. Results indicate that the risk of ASF in 2019 was predominantly focused on those regions which already had numerous cases in 2018 (Poland, Lithuania, Hungary, Romania, and Latvia). The riskiest pathway for ASFV transmission to pigs was the movement of wild boar for Eastern European countries and legal trade of pigs for Western European countries. New infections are more likely to occur in wild boar rather than pigs, for both the pig meat and wild boar movement pathways. Our results provide an opportunity to focus surveillance activities and thus increase our ability to detect ASF introductions earlier, a necessary requirement if we are to successfully control the spread of this devastating disease for the pig industry
- …
