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The accurate modelling and forecasting of the popularity of emerging fields can benefit researchers by allocating resources and efforts on promising research directions. While existing forecasting approaches enjoy various levels of success, most suffer from at least one of the following three challenges: a limited scope due to having to mine topic terms from only a few documents, low generalizability due to assigning arbitrary binary classifications on topics to be either emerging, non-emerging, or using an emerging topic or field of study’s historical features as inputs to forecast its future popularity while disregarding the existing effect of a “cold start”. In this thesis, we propose a framework inclusive of two algorithms. The first algorithm is a customised ontology extraction algorithm that can generate a field of study taxonomy from a scholarly database when none exists. Using the field of study taxonomy, the second forecasting algorithm addresses the three challenges in three steps. Firstly, we leverage the field of study taxonomy present in most academic databases to obtain a neighbourhood of trending fields within the discipline of the field of study of interest. Then, dynamic time warping is used to measure the similarity of each neighbour’s trending pattern compared to the trending pattern of the field of study of interest. Lastly, we conduct multivariate forecasting using a RNN model such as long short-term memory (LSTM) or dual attention recurrent neural networks (DA-RNN) while utilizing the historical popularity scores of similar trending neighbours as input. Experimental results on 10 emerging and non-emerging fields of study showcases the existence and various dynamics of “cold start”. In addition, the proposed algorithm is also shown to greatly reduce the RMSE, MAE, and MAPE of forecasts against traditional methods for emerging fields while retaining similar performance for non-emerging fields. This validates the significance of these challenges against existing methods and provides insight on the dependency structure of emerging topics with their historical features.

PurposeThe purpose of this paper is to offer the latest empirical findings of the difficulties and challenges in teaching New Senior Secondary (NSS) Liberal Studies in Hong Kong from the perspective of pre-service teachers.Design/methodology/approachThis qualitative study is based on Danielewicz’s critical pedagogy framework for identity development. A sample of four pre-service teachers were recruited from the last cohort of final-year bachelor of education students at the University of Hong Kong. They were invited to engage in dialogues of enquiry, through which they recount their teaching encounters during their teaching practices. Emphasis would be put on two relevant pedagogical principles, including deliberation and reflexivity, which are of particular relevance to the case of Liberal Studies.FindingsChallenges revealed the dispositions of conformist learning among the students, manifested in forms of misquoted information and the populist sentiments mirrored from mainstream media, which cost teachers extra efforts to facilitate inquiry-based learning. Adopting deliberation and reflexivity as pedagogical principles, student–teachers responded with attempts to reconnect daily life experiences to teaching, bringing back the social context of knowledge and seeking synergy between traditional and liberatory teaching methods.Research limitations/implicationsThis study is drawn from a relatively small sample of pre-service teachers and may run the risk of over-generalization. Moreover, this study tends to neglect other factors such as classroom dynamics, school culture, colleagues’ rapport and students’ responses.Originality/valueGiven the novelty of Liberal Studies as a compulsory subject under the NSS curriculum and its specificity in Hong Kong education system, the amount of literature devoted to this area has been inadequate; among the available studies, the majority tend either to focus on the macro level, addressing the broader narratives of education policies and curriculum studies (e.g. Fung and Yip, 2010; Cheung and Leung, 1998) or to discuss the topic with exclusive reference to political transition and post-colonialism in the 1980s and 1990s (e.g. Morris and Chan, 1997). Studies on the micro level have generally paid little attention to the dynamics of Liberal Studies teaching, focusing instead on its relationships with other aspects such as private tutoring (Chan and Bray, 2014) and cultural representations of religion in Liberal Studies textbooks (Jackson and Han, 2016); pedagogical studies on the subject remain a minority.

Storm surge and waves associated with tropical cyclones carry significant amounts of pollutants into the marine environment. This study evaluated the effects of Typhoon Mangkhut (7–18 September 2018) on marine debris pollution including macro-debris (>2.5 cm) and microplastics (5 μm–5 mm) in Hong Kong. Sampling was repeated on four beaches, two each from protected and exposed coastal areas, spanning from the eastern to western waters before and after the cyclone. For macro-debris, an average density of 0.047 items m−2 and 0.54 items m−2 was obtained before and after the cyclone, respectively or an 11.4-fold increase, with plastic being the most dominant type (61.9–93.3% and 80.7–92.4% before and after the cyclone, respectively) among total beached debris in all four beaches. Likewise, higher mean microplastic abundances were found in the post-cyclone period (335 items kg−1 sediment) when compared with the pre-cyclone period (188 items kg−1 sediment). The depositional dynamics for both macro-debris and microplastic were site-specific due to factors such as wind direction and the associated storm surge, topography and orientation of the site, and proximity to urban areas. This study has demonstrated the role cyclone induced overwash plays on introducing plastic pollution to beach environments. Considering an increase in both the intensity and frequency of cyclone in the future due to global warming, and a tremendous increase in marine plastic debris, more research effort should be spent on this understudied problem.

The visual survey is the most common method to quantify and characterize beach litter. However, it is very labor intensive and difficult to carry out on beaches which are remote or difficult to access. We suggest an alternative approach for assessing beach litter using an unmanned aerial vehicle (UAV), or aerial drone, with automated image requisition and processing. Litter of different sizes, colours, and materials were placed randomly on two beaches. Images of beaches with different substrates were obtained by the drone at different operating heights and light conditions and litter on the beaches was identified from the photos by untrained personnel. The quantification of beach litter using the drone was three times faster than that by visual census. This study has demonstrated the potential of using the drone as a cost-effective and an efficient sampling method in routine beach litter monitoring programs.

While Matteo Ricci inaugurated a fruitful dialogue between Christianity and Confucianism, today this dialogue must account for all of Chinese culture, including Daoism. Church Fathers, such as St. Augustine of Hippo, made great contributions to theology out of their profound experience of God and the encounter between Christianity and Latin culture that has its roots in Greek philosophy. In this article, the author attempts to read the mystery of the Trinity using categories of Chinese thought. He finds helpful for understanding the Trinitarian relationship the Daoist concepts of the dialectic of harmony containing many elements: the abiding relationship of qi between the yin and the yang, the relationship between being and non-being, Dao and De, the imprints of one and three in all things, and the concept of self-emptying aiming at wu-wei (non-doing) as an ultimate goal of a human being in harmony with the Dao. He also finds that Chinese culture’s values of harmony, humility, and intuitiveness and its emphasis on relationship befit a good disposition for approaching the mystery of the Trinity, which is essential to Christianity. The proposal of this prolegomenon is that an in-depth analysis of Daoism and the Christian Trinitarian theology can contribute to the inculturation of the Christian faith in the Chinese context in ways that can contribute to the positive development of Chinese culture in today’s world.

Photodynamic therapy (PDT) is recently developed as an effective treatment for malignant disease. In PDT, the photosensitizer eradicates tumour by induction of apoptosis. In this study, we investigated the mechanistic actions of a recently developed second generation photosensitizer, Zn-BC-AM, on nasopharyngeal carcinoma (NPC) cells. Zn-BC-AM was found to localize in the mitochondria, endoplasmic reticulum (ER), and golgi body. Photoactivation of Zn-BC-AM loaded NPC cells resulted in a rapid collapse of mitochondrial membrane potential (Deltapsim) (15 min), followed by the release of cytochrome c (1 h), and activation of caspases-9 and -3 (4 h). Expression of ER chaperones Bip/Grp78 and Grp94, and ER resident lectin-like chaperone calnexin (CNX) was also enhanced in PDT-stressed NPC cells. Caspase-12, an important caspase involved in ER stress-induced apoptosis, was also activated. Inhibition of Ca2+ uptake into mitochondria by ruthenium red (RR) or loading the cells with EGTA-AM, an agent that buffers intracellular Ca2+ released from ER, resulted in a significant reduction of Zn-BC-AM PDT-induced cell death. These observations suggest that both ER and mitochondria are the subcellular targets of Zn-BC-AM. Effective activation of ER- and mitochondria-mediated apoptotic pathways is responsible for Zn-BC-AM PDT-induced NPC cell death.

Two sulfonamide derivatives of porphycene, namely PS6 and PS6A, were synthesized, and their photodynamic efficacies on the nasopharyngeal carcinoma (NPC) cell line NPC/CNE-2 were evaluated. By comparing the 50% lethal concentrations (LC(50)) of these photosensitizers, we found that PS6A with a cationic ammonium group on the side chain exhibited potent photocytotoxicity on the NPC cell line. At a light dose of 1 J/cm(2), the LC(50) values of PS6 and PS6A for NPC cells were 11.6 and 1.92 microM, respectively. CNE-2 was found to rapidly take up PS6A in the first hour of incubation, and the uptake kinetics steadily increased to a plateau level after 18 h of incubation. The uptake of PS6A was temperature dependent. Over 99% of CNE-2 cells were sensitized by PS6A 24 h after drug treatment. Collapse of the mitochondrial membrane potential was also observed in PS6A photodynamic therapy (PDT)-treated CNE-2 cells 1.5 h after PDT. Confocal microscopy revealed that PS6A was predominantly localized in the mitochondria, lysosomes and Golgi bodies of NPC cells. Significant genotoxicity was not observed in CNE-2 cells. In functional studies, the in vitro formation of a capillary-like network of human umbilical vein endothelial cells in Matrigel was greatly inhibited by PS6A PDT in a dose-dependent manner. In conclusion, PS6A mediates both in vitro antitumor and antiangiogenic activities. PS6A might be a candidate for photodynamic treatment of NPCs.

This thesis gives a detailed discussion of Melnikov's method, which is an analytical tool to study global bifurcations that occur in homoclinic or heteroclinic loops, or in one-parameter families of periodic orbits of a perturbed system. Basic results of the Melnikov theory relating the number, positions and multiplicities of the limit cycles by the number, positions and multiplicities of the zeros of the Melnikov function are proved. We then give several examples to illustrate the theory. In particular, we use the Melnikov theory to study the exact number of limit cycles in the Bogdanov-Takens system with reflection symmetry. We then extend the first-order Melnikov theory to higher-order and establish some results relating the number, positions and multiplicities of the limit cycles by the number, positions and multiplicities of the zeros of the first non-vanishing Melnikov function. Next, we derive a formula for the second-order Melnikov function for certain perturbed Hamiltonian systems using Franchise's recursive algorithm. Finally, this formula is applied to an example.