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This study examines the osteoconductive and healing capabilities of locally implanted synthetic hydroxyapatite (sHAp) derived from eggshells in the central incisor sockets of rats.

Toxicity experiments were conducted in vitro and in vivo, to testify the safety dosage of sHAp. Around 24 mature male Sprague–Dawley (SD) rats had their upper central incisors extracted. The rats were placed into three groups of eight rats each: Group 1: the sockets of extracted central incisors were left unfilled (control), Group 2: filled up with commercially available hydroxyapatite (HAp) and Group 3: implanted with sHAp locally retrieved from eggshells. After extraction, four rats from each group were sacrificed at 2nd and 4th weeks. Maxillary tissue sections were obtained and stained with hematoxylin and eosin (H&E) and Masson’s trichome (MT) staining. Anti-osteocalcin (OCN) and proliferating cell nuclear antigen (PCNA) were used primary antibodies for immunohistochemistry (IHC) special labeling.

The results showed that the locally implanted sHAp was non-toxic and safe in cell lines (human osteoblast and fibroblast) and animals. Histological analysis of H&E, MT and IHC showed that the sockets treated with locally implanted sHAp from eggshells were filled with new bone tissue of comparable thickness to other groups.

This unique technique uses locally implanted eggshell-derived sHAp with osteoconductive characteristics. In an in vivo model, sHAps increased OCN and PCNA expression to improve bone repair.

Al-Tahrir Square (Liberation Square, in Arabic) is one of the main public spaces in Cairo, Egypt, and was the focal point for the Egyptian Revolution of January 2011. Although Tahrir Square is traditionally a noisy disliked crowded traffic zone, people gathering and demonstrating during 2011 transformed the a space into a livable interactive civic place (Bricoleurbanism, 2019). The study integrates three main subjects affecting each other: first; Tahrir history and its architectural description, second; activities and events of 2011 revolution at Tahrir and thirdly; theories and concepts of place/space transformations. Many space and place transformation cycles of the Al-Tahrir square have been studied for over a century. It shows that transformation happens when a “meaning” is added and “memories” turn into “behavior” and belonging (Pallasmaa, 2014). This chapter discusses how both the functions and the mental image of Al-Tahrir Square changed with the events along with the behavior of its occupants during 2011.

The square was analyzed to discover the mechanisms, motives, and reasons that caused such change. Furthermore, a comparison between Tahrir Square's status before and after 2011 was offered, according to “New Urbanism's successful places criteria” (PPS, 2009). Recently, physical and moral evacuation of the square deliberately enforced to replace its iconographic status as a place of revolution, with ancient Egyptian elements. This study elaborates on these results demonstrating how Cairo's Tahrir Square is a remarkable example of the dynamic nature of public spaces turning into places, and then into spaces again, due to actions of authority or the will of people.

The architecture, engineering and construction (AEC) industry encounter substantial risks and challenges in its evolution towards sustainable development. International businesses, multinational AEC organisations, technical professionals, project and portfolio management organisations face global connectivity challenges between business units, especially during the outbreak of novel coronavirus pandemic, to manage construction megaprojects (CMPs). That raises the need to manage global connectivity as a main strategic goal of global organisations. This paper aims to investigate barriers to integrating lean construction (LC) practices and integrated project delivery (IPD) on CMPs towards the global integrated delivery (GID) transformative initiatives and develop future of work (FOW) global initiatives in contemporary multinational AEC organisations.

A two-stage quantitative and qualitative research approach is adopted. The qualitative research methodology consists of a literature review to appraise barriers to integrating LeanIPD&GID on CMPs. Barriers are arranged into six-factor clusters (FCs), with a conceptualisation of LeanIPD&GID, GID strategy placements and FOW global initiatives with multiple validations. This analysis also involved semi-structured interviews and focus group techniques. Stage two consisted of an empirical questionnaire survey that shaped the foundation of analysis and findings of 230 respondents from 23 countries with extensive cosmopolitan experience in the construction of megaprojects. The survey examined a set of 28 barriers to integrating LeanIPD&GID on CMPs resulting from a detailed analysis of extant literature after validation. Descriptive and inferential statistical tests were exploited for data analysis, percentage scoring analysis, principal component analysis (PCA) and eigenvalues were used to elaborate on clustered factors.

The research conceptualised LeanIPD&GID principles and proposed GID strategy placements for LeanIPD&GID transformative initiatives and FOW global initiatives. It concluded that the most significant barriers to integration of LeanIPD&GID on CMPs are “lack of mandatory building information modelling (BIM) and LC industry standards and regulations by governments”, “lack of involvement and support of governments”, “high costs of BIM software licenses”, “resistance of industry to change from traditional working practices” and “high initial investment in staff training costs of BIM”. PCA revealed the most significant FCs are “education and knowledge-related barriers”, “project objectives-related barriers” and “attitude-related barriers”. Awareness of BIM in the Middle East and North Africa (MENA) region is higher than LC and LC awareness is higher than IPD knowledge. Whilst BIM adoption in the MENA region is higher than LC; the second is still taking its first steps, whilst IPD has little implementation. LeanBIM is slightly integrated, whilst LeanIPD integration is almost not present.

The research findings, conclusion and recommendation and proposed GID strategy placements for LeanIPD&GID transformative initiatives to integrating LeanIPD&GID on CMPs. This will allow project key stakeholders to place emphasis on tackling LeanIPD&GID barriers identified in this research and commence GID strategies. The study has provided effective practical strategies for enhancing the integration of LeanIPD&GID transformative initiatives on CMPs.