3 resultados para interconnectivity
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
This PhD work was aimed to design, develop, and characterize gelatin-based scaffolds, for the repair of defects in the muscle-skeletal system. Gelatin is a biopolymer widely used for pharmaceutical and medical applications, thanks to its biodegradability and biocompatibility. It is obtained from collagen via thermal denaturation or chemical-physical degradation. Despite its high potential as biomaterial, gelatin exhibits poor mechanical properties and a low resistance in aqueous environment. Crosslinking treatment and enrichment with reinforcement materials are thus required for biomedical applications. In this work, gelatin based scaffolds were prepared following three different strategies: films were prepared through the solvent casting method, electrospinning technique was applied for the preparation of porous mats, and 3D porous scaffolds were prepared through freeze-drying. The results obtained on films put into evidence the influence of pH, crosslinking and reinforcement with montmorillonite (MMT), on the structure, stability and mechanical properties of gelatin and MMT/gelatin composites. The information acquired on the effect of crosslinking in different conditions was utilized to optimize the preparation procedure of electrospun and freeze-dried scaffolds. A successful method was developed to prepare gelatin nanofibrous scaffolds electrospun from acetic acid/water solution and stabilized with a non-toxic crosslinking agent, genipin, able to preserve their original morphology after exposure to water. Moreover, the co-electrospinning technique was used to prepare nanofibrous scaffolds at variable content of gelatin and polylactic acid. Preliminary in vitro tests indicated that the scaffolds are suitable for cartilage tissue engineering, and that their potential applications can be extended to cartilage-bone interface tissue engineering. Finally, 3D porous gelatin scaffolds, enriched with calcium phosphate, were prepared with the freeze-drying method. The results indicated that the crystallinity of the inorganic phase influences porosity, interconnectivity and mechanical properties. Preliminary in vitro tests show good osteoblast response in terms of proliferation and adhesion on all the scaffolds.
Resumo:
In its open and private-based dimension, the Internet is the epitome of the Liberal International Order in its global spatial dimension. Therefore, normative questions arise from the emergence of powerful non-liberal actors such as China in Internet governance. In particular, China has supported a UN-based multilateral Internet governance model based on state sovereignty aimed at replacing the existing ICANN-based multistakeholder model. While persistent, this debate has become less dualistic through time. However, fear of Internet fragmentation has increased as the US-China technological competition grew harsher. This thesis inquires “(To what extent) are Chinese stakeholders reshaping the rules of Global Internet Governance?”. This is further unpacked in three smaller questions: (i) (To what extent) are Chinese stakeholders contributing to increased state influence in multistakeholder fora?; (ii) (how) is China contributing to Internet fragmentation?; and (iii) what are the main drivers of Chinese stakeholders’ stances? To answer these questions, Chinese stakeholders’ actions are observed in the making and management of critical Internet resources at the IETF and ICANN respectively, and in mobile connectivity standard-making at 3GPP. Through the lens of norm entrepreneurship in regime complexes, this thesis interprets changes and persistence in the Internet governance normative order and Chinese attitudes towards it. Three research methods are employed: network analysis, semi-structured expert interviews, and thematic document analysis. While China has enhanced state intervention in several technological fields, fostering debates on digital sovereignty, this research finds that the Chinese government does not exert full control on its domestic private actors and concludes that Chinese stakeholders have increasingly adapted to multistakeholder Internet governance as they grew influential within it. To enhance control over Internet-based activities, the Chinese government resorted to regulatory and technical control domestically rather than establishing a splinternet. This is due to Chinese stakeholders’ interest in retaining the network benefits of global interconnectivity.
Resumo:
This thesis investigates how individuals can develop, exercise, and maintain autonomy and freedom in the presence of information technology. It is particularly interested in how information technology can impose autonomy constraints. The first part identifies a problem with current autonomy discourse: There is no agreed upon object of reference when bemoaning loss of or risk to an individual’s autonomy. Here, thesis introduces a pragmatic conceptual framework to classify autonomy constraints. In essence, the proposed framework divides autonomy in three categories: intrinsic autonomy, relational autonomy and informational autonomy. The second part of the thesis investigates the role of information technology in enabling and facilitating autonomy constraints. The analysis identifies eleven characteristics of information technology, as it is embedded in society, so-called vectors of influence, that constitute risk to an individual’s autonomy in a substantial way. These vectors are assigned to three sets that correspond to the general sphere of the information transfer process to which they can be attributed to, namely domain-specific vectors, agent-specific vectors and information recipient-specific vectors. The third part of the thesis investigates selected ethical and legal implications of autonomy constraints imposed by information technology. It shows the utility of the theoretical frameworks introduced earlier in the thesis when conducting an ethical analysis of autonomy-constraining technology. It also traces the concept of autonomy in the European Data Lawsand investigates the impact of cultural embeddings of individuals on efforts to safeguard autonomy, showing intercultural flashpoints of autonomy differences. In view of this, the thesis approaches the exercise and constraint of autonomy in presence of information technology systems holistically. It contributes to establish a common understanding of (intuitive) terminology and concepts, connects this to current phenomena arising out of ever-increasing interconnectivity and computational power and helps operationalize the protection of autonomy through application of the proposed frameworks.