14,334 research outputs found

    Analytical studies on transient groundwater flow induced by land reclamation

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    In many coastal areas, land has been reclaimed by dumping fill materials into the sea. Land reclamation may have a significant effect on groundwater regimes, especially when the reclamation is at large scale. Analytical studies on the impact of land reclamation on steady-state ground water flow conditions were conducted previously, but transient analytical solutions are not yet available. Transient analytical solutions are derived to illustrate the temporal change of groundwater systems in response to land reclamation using two hypothetical models: a hillside aquifer and an oceanic elongated island. The analytical solutions show that when time is short, the water level in the reclaimed area increases significantly after reclamation while that in the original aquifer remains almost unchanged. When time is great, the change of water level in the reclaimed site becomes small but the increase of water level propagates into the original aquifer. For the specific parameters and aquifer geometry used in the examples, it takes at least over 100 years for the whole system to approach a new equilibrium. The island example demonstrates that land reclamation on one side of the island will eventually modify the groundwater regimes over the entire island, including the water level, water divide, and submarine groundwater discharge. The degree of the modification of the groundwater system and the time required for the system to approach a new equilibrium depend mainly on the hydraulic conductivity and storativity of the fill materials and the reclamation length. It is suggested that for a large reclamation project, the response of the groundwater regime to reclamation should be studied in detail to evaluate the long-term change of the flow system and the consequent environmental and engineering impacts. Copyright 2008 by the American Geophysical Union.published_or_final_versio

    Information and Communication Technology in Education in China: Policies and Practices

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    This seminar is co-organised by the Centre for Information Technology in Education (CITE) and Faculty of Education, HKU Current policies and practices in ICT in education in China were developed on the basis of its achievements in the area of instructional technology. Therefore, past policies and implementation strategies in instructional technology provided the foundation for the fast development in the area of ICT in education. This seminar will start with a brief review of the history of ICT in education in China. The current state of development in integration ICT into the school curriculum will be examined from five perspectives: curriculum development, resources development, contemporary distance education, application of information technology and teacher professional development. Finally, the seminar will discuss problems, challenges and strategies for further developments in this area in China.Ms Joy Hu is a Research Fellow at the China National Institute of Educational Research (CNIER). Ms Hu graduated from the Beijing Normal University with a BSc in Biology in 1991. She started her career as a biology teacher and then quickly moved into research on teaching and curriculum/textbook development in science and technology. Since joining CNIER in 1995, Ms Hu has been engaged in several large scale national research projects and contributed to curriculum and textbook development projects connected with the basic education reform in collaboration with scholars in Canada.published_or_final_versionCentre for Information Technology in Education, University of Hong Kon

    Chemical constituent analysis of the crown-of-thorns starfish Acanthaster planci and potential utilization value of the starfish as feed ingredient for animals

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    The crown-of-thorns starfish Acanthaster planci is a major management issue on coral reefs and the exploring of effective control methods to the starfish is an interesting goal. In this study, the chemical constituent of the starfish were analyzed and the toxicity of the starfish was tested when it was used as mice diet. The results showed that protein content of the starfish was 19.8 to 22.0% of dry weight and the amino acid composition was similar to that of fish meal. Though the starfish had little fatty acids (<1%), the fatty acids contained rich variety and unsaturated fatty acids on average accounted for more than 60% of total fatty acids. In addition, per gram (dry weight) of the starfish contained 65.4 to 97.4 ÎĽg astaxanthin, which was higher than that of shrimps. The starfish used as the feed for mice did not have negative influence on the growth and the health of the mice. Based on these results, we consider that the crown-of-thorns starfish A. planci has the potential to be an ingredient for animal feeds, thus reducing the usage of fish meal, fish oil and carotenoids. Hence, a method for resource utilization and control of A. planci was suggested.Key words: Chemical constituents, Acanthaster planci, astaxanthin, resource utilization, feed ingredient

    Large-scale monocular SLAM by local bundle adjustment and map joining

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    This paper first demonstrates an interesting property of bundle adjustment (BA), "scale drift correction". Here "scale drift correction" means that BA can converge to the correct solution (up to a scale) even if the initial values of the camera pose translations and point feature positions are calculated using very different scale factors. This property together with other properties of BA makes it the best approach for monocular Simultaneous Localization and Mapping (SLAM), without considering the computational complexity. This naturally leads to the idea of using local BA and map joining to solve large-scale monocular SLAM problem, which is proposed in this paper. The local maps are built through Scale-Invariant Feature Transform (SIFT) for feature detection and matching, random sample consensus (RANSAC) paradigm at different levels for robust outlier removal, and BA for optimization. To reduce the computational cost of the large-scale map building, the features in each local map are judiciously selected and then the local maps are combined using a recently developed 3D map joining algorithm. The proposed large-scale monocular SLAM algorithm is evaluated using a publicly available dataset with centimeter-level ground truth. ©2010 IEEE

    Selective fluorescent probes for molecular imaging of ROS/RNS: Challenges and opportunities

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    Session-1: The Power of Technology - Key Note Speakerpublished_or_final_versio

    Studies on hemorrhagic pneumonia in Moschus sifanicus

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    A series of investigations were carried out including epidemiology, etiology and pathology on hemorrhagic pneumonia in Moschus sifanicus, which had prevailed in Xinglong Mountain National Nature Reserve District in Gansu province of China. The results indicated that the prevalence of thisdisease could be correlated with local humidity in Xinglong Mountain in Gansu province of China. The disease is caused by single infection of Pasteurella multocida or mix of P. multocida, Escherichia coli and Pseudomonas aeruginosa, and is a contagious disease. The pathological changes were mainly manifested in the vessel wall of bronchia and bronchiole appeared congested, bleeding, edemic with infiltration of inflammatory cells, mucosa of bronchiole degenerates, with the presence of necrosis and exfoliation, pulmonary alveolus generated suppuration, disaggregation and necrosis. It was concluded that the diseases are mainly caused by local bacteria and affected M. sifanicus finally die of hemorrhagic or purulent, necrotic pneumonia

    Retrospective study of neonatal intestinal obstruction in Calabar: Aetiology and outcome

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    Neonatal intestinal obstruction is the most common surgical emergency in the newborn period. Prompt diagnosis and urgent management improve the chances of a favorable outcome. Aetiology and outcome may vary in different parts of the same country.Objective: To evaluate the aetiology and factors associated with mortality in neonates presenting with intestinal obstruction in University of Calabar Teaching Hospital, Calabar, Nigeria.Method: This was a retrospective study of clinical records of neonates presenting with features of intestinal obstruction over an eight year period. The biodata, diagnosis, management and outcome for the neonates were documented.Result: Forty neonates; 26(65%) males and 14(35.5%) females were studied. Imperforate anus was seen in 40% of subjects while Hirschsprung’s disease and intestinal atresia each were seen in 10%. Aetiology could not be determined in about a fifth of the cases. Age less than one week at presentation was significantly associated with a poor outcome. No case had surgical intervention within twenty-four hours of presentation. The overall mortality was 30%, most of these 9 (75%) was due to anorectal malformations.Conclusion: The management and outcome of neonatal intestinal  obstruction in our setting is poor. There is urgent need to upgrade our neonatal intensive care services to improve outcome in affected neonates. More Paediatric surgeons are required to reduce the gross inadequacy of expert as this would improve on the surgical intervention time as reported in this study.Key Words: Neonatal intestinal obstruction Hirschprung’s diseas

    The rationale for quadrivalent influenza vaccines

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    Two antigenically distinct lineages of influenza B viruses have circulated globally since 1985. However, licensed trivalent seasonal influenza vaccines contain antigens from only a single influenza B virus and thus provide limited immunity against circulating influenza B strains of the lineage not present in the vaccine. In recent years, predictions about which B lineage will predominate in an upcoming influenza season have been no better than chance alone, correct in only 5 of the 10 seasons from 2001 to 2011. Consequently, seasonal influenza vaccines could be improved by inclusion of influenza B strains of both lineages. The resulting quadrivalent influenza vaccines would allow influenza vaccination campaigns to respond more effectively to current global influenza epidemiology. Manufacturing capacity for seasonal influenza vaccines has increased sufficiently to supply quadrivalent influenza vaccines, and methods to identify the influenza B strains to include in such vaccines are in place. Multiple manufacturers have initiated clinical studies of quadrivalent influenza vaccines. Data from those studies, taken together with epidemiologic data regarding the burden of disease caused by influenza B infections, will determine the safety, effectiveness, and benefit of utilizing quadrivalent vaccines for the prevention of seasonal influenza disease
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