4 resultados para 358

em AMS Tesi di Dottorato - Alm@DL - Università di Bologna


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This thesis proposes a new document model, according to which any document can be segmented in some independent components and transformed in a pattern-based projection, that only uses a very small set of objects and composition rules. The point is that such a normalized document expresses the same fundamental information of the original one, in a simple, clear and unambiguous way. The central part of my work consists of discussing that model, investigating how a digital document can be segmented, and how a segmented version can be used to implement advanced tools of conversion. I present seven patterns which are versatile enough to capture the most relevant documents’ structures, and whose minimality and rigour make that implementation possible. The abstract model is then instantiated into an actual markup language, called IML. IML is a general and extensible language, which basically adopts an XHTML syntax, able to capture a posteriori the only content of a digital document. It is compared with other languages and proposals, in order to clarify its role and objectives. Finally, I present some systems built upon these ideas. These applications are evaluated in terms of users’ advantages, workflow improvements and impact over the overall quality of the output. In particular, they cover heterogeneous content management processes: from web editing to collaboration (IsaWiki and WikiFactory), from e-learning (IsaLearning) to professional printing (IsaPress).

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This dissertation focuses on “organizational efficacy”, in particular on employees’ beliefs of organizational capacity to be efficacious. Organizational efficacy is considered from two perspectives – competing values approach and collective efficacy, and evaluated in internationalized companies. The dissertation is composed of three studies. The data were collected in thirteen Italian companies on different stages of internationalization for a total number of respondents is 358. In the first study the factorial validity of the competing values instrument (Rohrbaugh, 1981) was investigated and confirmed. Two scales were used to measure collective efficacy: a general collective efficacy scale (Bohn, 2010), and a specific collective efficacy scale, developed following suggestions of Borgogni et al. (2001), it evaluates employees’ beliefs of efficacy of organizations in the international market. The findings suggest that competing values and collective organizational efficacy instruments may provide a multi-faceted measurement of employees’ beliefs of organizational efficacy. The second study examined the relationship between organizational efficacy and collective work engagement. To measure collective work engagement the UWES-9 (Schaufeli & Bakker, 2003) was adapted at the group level; its factor structure and reliability were similar to the standard UWES-9. The findings suggest that organizational efficacy fully predicts collective work engagement. Also we investigated whether leadership moderates the relationship between organizational efficacy and collective work engagement. We operationalized leadership style with MLQ (Bass & Avolio, 1995); the results suggest that intellectual stimulation and idealized influence (transformational leadership) and contingent reward (transactional leadership) enhance the impact of organizational efficacy on collective work engagement. In the third study we investigated organizational efficacy and collective work engagement in internationalized companies. The findings show that beliefs of organizational efficacy vary across companies in different stages of internationalization, while no significant difference was found for collective work engagement. Limitations, practical implications and future studies are discussed in the conclusion.

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Toxoplasma gondii is an obligate intracellular parasite capable of infecting virtually all warm-blooded species, including humans, but cats are the only definitive hosts. Humans or animals acquire T. gondii infection by ingesting food or water contaminated with sporulated oocysts or by ingesting tissue cysts containing bradyzoites. Toxoplasmosis has the highest human incidence among zoonotic parasitic diseases, but it is still considered an underreported zoonosis. The importance of T. gondii primary infection in livestock is related to the ability of the parasite to produce tissue cysts in infected animals, which may represent important sources of infection for humans. Consumption of undercooked mutton and pork are considered important sources of human Toxoplasma gondii. The first aim of this thesis was to develop a rapid and sensitive in- house indirect ELISA for the detection of antibodies against T. gondii in sheep sera. ROC-curve analysis showed high discriminatory power (AUC=0.999) and high sensitivity (99.4%) and specificity (99.8%) of the method. The ELISA was used to test a batch of sheep sera (375) collected in the Forli-Cesena district. The overall prevalence was estimated at 41.9% demonstrating that T. gondii infection is widely distributed in sheep reared in Forli-Cesena district. Since the epidemiological impact of waterborne transmission route of T.gondii to humans is now thought to be more significant than previously believed, the second aim of the thesis was to evaluate PCR based methods for detecting T. gondii DNA in raw and finished drinking water samples collected in Scotland. Samples were tested using a quantitative PCR on 529 bp repetitive elements. Only one raw water sample (0.3%), out of the 358 examined, tested T. gondii positive demonstrating that there is no evidence that tap water is a source of Toxoplasma infection in Scotland.