2,567 research outputs found

    The economic link-up of Hong Kong and Guangdong : structural and development problems

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    The phenomenal link-up between the Hong Kong and Guangdong economies has been proceeding at a remarkable speed since the launching of the Chinese economic reform in late 1978. The process has largely been market-driven and seems to suit the short-run comparative advantage on both sides. In essence, however, it has been a result of a reallocation of resources across the border, made possible by China\u27s open policy. It has not yet led to a benign form of developmental upgrading which embodies the strengthening of the long-term foundation for productivity and competitiveness enhancement. Indeed, the tremendous windfall profits obtained so far could be regarded as a disincentive for R & D investments as well as beneficial decisions that may incur painful side effects in the short run. Problems which are structural and developmental in nature, including bias and duplication in production patterns, inflationary pressure, widening income inequality, and the loss of competitiveness, have emerged in both Hong Kong and Guangdong. These problems could be traced to the lack of countervailing forces that promote far-sighted strategies, vis-a-vis short-termism driven by market supplies and demands and yearly profit maximization. In this paper, we argue that while better coordination should be pursued to ensure mutually beneficial developments and to avoid duplication in efforts and undesirable convergence in industrial structures, the future trajectories of the two economies will not and cannot be identical. Hong Kong and Guangdong are different in size and endowments, and face dissimilar political and economic frameworks. Independent policies and measures to nurture specific advantages and to solve internal problems have to be made. Indeed, a certain distancing in economic relations between the two economies will be healthy

    A preliminary investigation of prenatal stress and risk of autism spectrum disorder

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    Thesis (B.Sc)--University of Hong Kong, 2010.Includes bibliographical references (p. 26-28)."A dissertation submitted in partial fulfillment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2010."This paper was a retrospective survey investigating the association between prenatal stress and risk of ASD in Chinese population. Twenty-eight mothers of children diagnosed with ASD, and thirty-eight mothers of children with no diagnoses of neurodevelopmental diseases were interviewed. The survey mainly investigated the incidence and intensity of prenatal stress, birth conditions and developmental problems of children, maternal health conditions, and the participants’ coping strategies towards prenatal stress. Higher overall intensity and higher incidence of prenatal stress were found to be experienced by mothers of ASD children. The ASD group also showed higher incidence of prematurity, birth complications, health problems, maternal illnesses, advanced maternal age, and developmental problems. This proposed prenatal stress as a possible risk factor of ASD and the other developmental problems associated with ASD.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

    Evaluation of deformed image-based dose calculations for adaptive radiotherapy of nasopharyngeal carcinoma

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    The ultimate goal of adaptive radiotherapy (ART) is to deliver truly customized radiation treatments. Currently, the quality of cone-beam computed tomography (CBCT) images is still inferior to that of conventional CT images in contour delineations and dose calculations for replanning purposes. This retrospective study aims to evaluate the dosimetric accuracy of using deformed conventional CT images for dose calculations, in the hope of inferring the feasibility of ART using planning CT (PCT) images that deformed to up-to-date CBCT images for patients with nasopharyngeal carcinoma (NPC). Thirty consecutive patients with NPC who had undergone 1 replan in their radiotherapy treatments were selected. The pretreatment PCT images were deformed to match the mid-treatment PCT images by deformable image registration. The same volumetric modulated arc therapy plan was then calculated on the deformed PCT images. The resulting dose distributions and dose volume histograms of the tumors and organs at risk (OARs) were compared with the original plan. Five dose levels, D98%, D95%, D50%, D5%, and D2%, were recorded for 9 NPC targets. Four dose levels, Dmax, D10%, D50%, and Dmean, were recorded for 15 OARs. The greatest percentage difference in observed dose for D98%, D95%, D50%, D5%, and D2% of the targets were 1.71%, 1.55%, 0.64%, 0.97%, and 1.13%, respectively. The greatest percentage difference in observed dose for Dmax, D10%, D50%, and Dmean of the OARs were -26.51% (left optic nerve), -17.06% (left optic nerve), 56.70% (spinal cord), and 18.97% (spinal cord), respectively. In addition, 29 of 45 (64%) dosimetric end points of the targets showed statistically significant dose differences (p < 0.05) between the original plan and the plan calculated on deformed images. Forty-nine of 60 (82%) dosimetric end points of the OARs also showed statistically significant dose differences (p < 0.05). Dose calculations using deformed PCT images could result in significant dose uncertainties in target volumes and OARs. Larger dose deviations were found in OARs in comparison with target volumes. The spinal cord and optic nerve showed the greatest percentage dose differences and the clinical significance has yet to be determined. Deformable registration error was believed to be the problem causing the dose deviations. Owing to unknown clinical significanceof dose deviation results obtained from this study, a conventional CT scan is still required for replanning in patients with NPC who are experiencing significant anatomical changes during the course of radiation treatment. [Abstract copyright: Copyright © 2017 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

    The pseudo scalar form factor of the nucleon, the sigma-like term, and the L0+L_0^+ amplitude for charged pion electro-production near threshold

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    The pseudo scalar form factor, which represents the pseudo scalar quark density distribution due to finite quark masses on the nucleon, is shown to manifest itself with the induced pseudo scalar form factor in the L0+L_0^+ amplitude for the charged pion electro-production. Both form factors show their own peculiar momentum dependence. Under the approximation on which the Goldberg-Treimann relation holds, a sum of both form factors' contributions accounts for the t-channel contribution in the charged pion electro-production near threshold.Comment: 10 page

    Topical CpG Oligodeoxynucleotide Adjuvant Enhances the Adaptive Immune Response against Influenza A Infections

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    Current influenza vaccines generate humoral immunity, targeting highly variable epitopes and thus fail to achieve long-term protection. T cells recognize and respond to several highly conserved epitopes across influenza serotypes. A strategy of raising strong cytotoxic T cell memory responses to epitopes conserved across serotypes would provide cross serotype protection, eliminating the need for annual vaccination. We explored the adjuvant potential of epicutaneous (ec) and subcutaneous (sc) delivery of CpG oligodeoxynucleotide in conjunction with subcutaneous protein immunization to improve protection against influenza A virus infections using a mouse model. We found enhanced long-term protection with ecCpG compared to scCpG as demonstrated by reduced viral titers in the lungs. This correlated with increased antigen-specific CD8 T cells in the airways and the lungs. The memory T cell response after immunization with ecCpG adjuvant was comparable to memory response by priming with influenza A virus infection in the lungs. In addition, ecCpG was more efficient than scCpG in inducing the generation of IFN-γ producing CD4 T cells. The adjuvant effect of ecCpG was accompanied with its ability to modulate tissue-homing molecules on T cells that may direct them to the site of infection. Together, this work provides evidence for using ecCpG to induce strong antibody and memory T cell responses to confer protection against influenza A virus infection

    The Spectrum of Goldstini and Modulini

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    When supersymmetry is broken in multiple sectors via independent dynamics, the theory furnishes a corresponding multiplicity of "goldstini" degrees of freedom which may play a substantial role in collider phenomenology and cosmology. In this paper, we explore the tree-level mass spectrum of goldstini arising from a general admixture of F-term, D-term, and almost no-scale supersymmetry breaking, employing non-linear superfields and a novel gauge fixing for supergravity discussed in a companion paper. In theories of F-term and D-term breaking, goldstini acquire a mass which is precisely twice the gravitino mass, while the inclusion of no-scale breaking renders one of these modes, the modulino, massless. We argue that the vanishing modulino mass can be explained in terms of an accidental and spontaneously broken "global" supersymmetry.Comment: 10 pages, 2 figures; v2: typo corrected, references updated; v3: version to appear in JHE

    Rescaling of metal oxide nanocrystals for energy storage having high capacitance and energy density with robust cycle life

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    Nanocrystals are promising structures, but they are too large for achieving maximum energy storage performance. We show that rescaling 3-nm particles through lithiation followed by delithiation leads to high-performance energy storage by realizing high capacitance close to the theoretical capacitance available via ion-to-atom redox reactions. Reactive force-field (ReaxFF) molecular dynamics simulations support the conclusion that Li atoms react with nickel oxide nanocrystals (NiO-n) to form lithiated core–shell structures (Ni:Li_2O), whereas subsequent delithiation causes Ni:Li_2O to form atomic clusters of NiO-a. This is consistent with in situ X-ray photoelectron and optical spectroscopy results showing that Ni^(2+) of the nanocrystal changes during lithiation–delithiation through Ni^0 and back to Ni^(2+). These processes are also demonstrated to provide a generic route to rescale another metal oxide. Furthermore, assembling NiO-a into the positive electrode of an asymmetric device enables extraction of full capacitance for a counter negative electrode, giving high energy density in addition to robust capacitance retention over 100,000 cycles

    Pharmacogenomics and the Yin/Yang actions of ginseng: anti-tumor, angiomodulating and steroid-like activities of ginsenosides.

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    In Chinese medicine, ginseng (Panax ginseng C.A. Meyer) has long been used as a general tonic or an adaptogen to promote longevity and enhance bodily functions. It has also been claimed to be effective in combating stress, fatigue, oxidants, cancer and diabetes mellitus. Most of the pharmacological actions of ginseng are attributed to one type of its constituents, namely the ginsenosides. In this review, we focus on the recent advances in the study of ginsenosides on angiogenesis which is related to many pathological conditions including tumor progression and cardiovascular dysfunctions. Angiogenesis in the human body is regulated by two sets of counteracting factors, angiogenic stimulators and inhibitors. The 'Yin and Yang' action of ginseng on angiomodulation was paralleled by the experimental data showing angiogenesis was indeed related to the compositional ratio between ginsenosides Rg1 and Rb1. Rg1 was later found to stimulate angiogenesis through augmenting the production of nitric oxide (NO) and vascular endothelial growth factor (VEGF). Mechanistic studies revealed that such responses were mediated through the PI3K-->Akt pathway. By means of DNA microarray, a group of genes related to cell adhesion, migration and cytoskeleton were found to be up-regulated in endothelial cells. These gene products may interact in a hierarchical cascade pattern to modulate cell architectural dynamics which is concomitant to the observed phenomena in angiogenesis. By contrast, the anti-tumor and anti-angiogenic effects of ginsenosides (e.g. Rg3 and Rh2) have been demonstrated in various models of tumor and endothelial cells, indicating that ginsenosides with opposing activities are present in ginseng. Ginsenosides and Panax ginseng extracts have been shown to exert protective effects on vascular dysfunctions, such as hypertension, atherosclerotic disorders and ischemic injury. Recent work has demonstrates the target molecules of ginsenosides to be a group of nuclear steroid hormone receptors. These lines of evidence support that the interaction between ginsenosides and various nuclear steroid hormone receptors may explain the diverse pharmacological activities of ginseng. These findings may also lead to development of more efficacious ginseng-derived therapeutics for angiogenesis-related diseases
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