5,186 research outputs found
Agent-Based Modeling of the Prediction Markets
No full textWe propose a simple agent-based model of the political election prediction market which reflects the intrinsic feature of the prediction market as an information aggregation mechanism. Each agent has a vote, and all agents’ votes determine the election result. Some of the agents participate in the prediction market. Agents form their beliefs by observing their neighbors’ voting disposition, and trade with these beliefs by following some forms of the zero-intelligence strategy. In this model, the mean price of the market is used as a forecast of the election result. We study the effect of the radius of agents’ neighborhood and the geographical distribution of information on the prediction accuracy. In addition, we also identify one of the mechanisms which can replicate the favorite-longshot bias, a stylized fact in the prediction market. This model can then provide a framework for further analysis on the prediction market when market participants have more sophisticated trading behavior.Prediction market, Agent-based simulation, Information aggregation mechanism, Prediction accuracy, Zero-intelligence agents, Favorite-longshot bias
THOR-ISO: a global circulation model for exoplanets on an icosahedral grid
No full textIn this presentation I will describe the details and first results of our new dynamical code for exoplanet atmospheres. This model is part of the Exoclimes Simulation Platform (ESP), and is a project of the Exoplanet and Exoclimes Group (see www.exoclime.org). The model I will present solves the complex physical and dynamical equations that include fundamental principles of atmospheric fluid dynamics and various idealisations of radiative transfer and dry convection, among others. I will also show the results of the first successful benchmark tests for this model, where we explore the results of the model for Earth-like and Hot-Jupiter like conditions. The analysis of the results from this complex and detailed model, will help us to have a better understanding of the diversity of climates and atmospheric circulations that we expect to find in the multitude of exoplanets already discovered. ..
Prospects for transient gravitational waves at r-mode frequencies associated with pulsar glitches
No full textt Glitches in pulsars are likely to trigger oscillation modes in the fluid interior of neutron stars. We examined these oscillations specifically at r-mode frequencies. The excited r-modes will emit gravitational waves and can have long damping time scales (minutes - days). We use simple estimates of how much energy the glitch might put into the r-mode and assess the detectability of the emitted gravitational waves with future interferometers
Transcriptional regulation governing Th17 cells in experimental CNS autoimmunity
No full textAbstractCaleb Wong Han, Aaron Han Heng, Stephen Pederson, Shaun McColl, Iain Comerfor
Seng Heng Bank: History and Acquisition by Industrial and Commercial Bank of China
No full textThis book examines the success story of Seng Heng Bank (SHB), the successful acquisition of SHB by Industrial and Commercial Bank of China (ICBC), and the continuing sound management and performance of ICBC (Macau). It shows how a loss-making small bank grew into one of the best banks in Macao and highlights the achievement, awards, and recognition of SHB. The authors detail the SHB acquisition process by ICBC, the biggest bank in the world in terms of total assets. They identify the main contributing factors for the success of SHB and draw conclusions and implications for bank managers in the region and beyond. This book will be of interest to finance professionals and business scholars. © The Editor(s) (if applicable) and The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. 2021
Class invariants from a new kind of Weber-like modular equation
No full textA technique is described for explicitly evaluating quotients of the Dedekind eta function at quadratic integers. These evaluations do not make use of complex approximations but are found by an entirely `algebraic' method. They are obtained by means of specialising certain modular equations related to Weber's modular equations of `irrational type'. The technique works for certain eta quotients evaluated at points in an imaginary quadratic field with discriminant d1 (mod 8)
Breidablikk : eksteriøre fargeundersøkelser
No full textOppdragsgiver: Stavanger MuseumArkeologisk museum, Universitetet i Stavanger (UiS) fikk i august 2018 bestilling fra Stavanger museum (MUST) v/Michael Heng om å utføre fargeundersøkelse på sveitservillaen Breidablikk (1881). Malerikonservatorene Anne Ytterdal og Hilde S. Moore (UiS) foretok en befaring for å vurdere omfang den 13.08.18 sammen med Michael Heng. Det er et ønske om at fargehistorien på bygningen dokumenteres som grunnlag for fargevalg for ny oppmaling. Hele villaen skal males med oppstart av sørfasaden i 2019. Deler av malingen som er på eksteriøret i dag er svært nedbrutt og det vil være nødvendig å fjerne mye før ny oppmaling. Det ble fra oppdragsgivers side ansett som viktig å få en komplett oversikt over antall lag samt registrering og NCS-koding før nødvendig fjerning av maling. Undersøkelsene ble foretatt av malerikonservatorene Anne Ytterdal og Hilde S. Moore over perioden 26.03.19 – 01.07.19
The implications of foreign aid fungibility for development assistance
No full textA foreign aid or foreign lending policy that focuses exclusively on project financing may have unintended consequences, report the authors. New research shows that aid intended for crucial social and economic sectors often merely substitutes for spending that recipient governments would have undertaken anyway and the funds that are thereby freed up are spent for other purposes. If the aid funds something that would have been done anyway, traditional ways of evaluating the aid's effectiveness are not really accurate. Ifaid funds are fungible and the recipient's public spending program is unsatisfactory, project lending may not be cost-effective. If the recipient's public spending program is satisfactory, perhaps the donor should finance a portion of it instead of financing individual projects. One solution to the problem of fungibility, then, is that donors could tie assistance to an overall public spending program (in the recipient country) that provides adequate resources to crucial sectors. To make this kind of reform operational, the authors propose a new lending instrument: a public expenditure reform loan (PERL). A PERL would tie an institution's lending strategy to the recipient country's achievement of mutually agreed-upon development goals. Everyone agrees that better donor coordination is needed, but it has been difficult to achieve because some donors tend to prefer projects (usually with the national flag flying over them). By agreeing on a public expenditure program and financing a portion of it, the World Bank credibly ask other donors to do the same.Payment Systems&Infrastructure,Development Economics&Aid Effectiveness,Gender and Development,Decentralization,Economic Adjustment and Lending,Development Economics&Aid Effectiveness,Poverty Assessment,National Governance,Economic Adjustment and Lending,Public Sector Economics&Finance
Mechanisms and Gene Regulation Associated with Inhibition of Phagocytic Killing in Streptococcus mutans
No full text轉糖鏈球菌(Streptococcus mutans) 為人類齲齒的致病菌，並也是人類感染性心內膜炎的機會致病菌之一。在感染性心內膜炎發展的初期，轉糖鏈球菌必須由口腔進入血液循環之中，而暴露在血漿之中。血漿是一成份複雜的豐富培養基。一旦轉糖鏈球菌進入血液中後，細菌必須面對新環境所產生的壓力；而環境中壓力所產生的訊號也會刺激細菌特別基因的表現來適應與生存於改變的環境中。
在本實驗的第一部份，我們利用微陣列分析來探討轉醣鏈球菌受血漿刺激後之基因的表現。在本篇研究中，我們著重於轉糖鏈球菌內與氧化還原相關的基因及一個two component system response regulator, scnR 二者間的關係。經過胺基酸序列比對後，我們發現到scnR 與Streptococcus pyogenes 內用以抵抗吞噬細胞毒殺作用的irr response regulator 有35 % 的一致性。爾後，我們建構了轉糖鏈球菌scnR 的突變株，並分析在抵抗Raw264.7 吞噬作用以及細胞毒殺作用能力上，與轉糖鏈球菌野生株的差異。我們發現scnR 突變株在消弭經由Raw264.7 所產生的反應性含氧物種之能力上較野生株降低許多。我們也發現，轉糖鏈球菌野生株在經過血漿刺激後，可以增加經過Raw264.7 毒殺作用後的存活率；然而，此現象卻沒有在scnR突變株中發現。因此，我們認為轉糖鏈球菌利用two component system response regulator scnR 調控下游與氧化還原相關基因的表現，對於抵抗Raw264.7 的毒殺作用是重要的；並且在經由血漿刺激後，是可以增加細菌scnR與氧化還原相關基因的表現。Streptococcus mutans, being the principal etiological agent of dental caries, is also one of the most common opportunistic pathogens isolated from patients with infective endocarditis (IE). As an early step in the development of infective endocarditis, S. mutans gains access to the bloodstream from the oral cavity, and exposes in human plasma. We hypothesized that plasma as a complex medium could trigger S. mutans cells to adapt to different stresses through inducing specific gene expression upon sensing of signals from the plasma components.
In the first part of this study, we used oligonucleotide DNA microarray to analyze the expression of the genes after plasma stimulation. We focused on the function of redox genes and one of the two component system response regulator, scnR, in this study. We found that the amino acid sequence of scnR showed 35% identify to irr response regulator, which is associated with ability against phagocytic killing in Streptococcus pyogenes. Furthermore, an isogenic scnR deletion mutant exhibited decreased ability to eliminate the reactive oxygen species (ROS) produced in Raw264.7 in comparison with wild-type S. mutans strain. In addition, plasma-induced resistance to phagocytic killing was significantly reduced in scnR deletion mutant. We hypothesize that the two component system response regulator, scnR, is important for S. mutans against phagocytic killing in Raw264.7 through stimulating redox genes expression.誌謝………………………………………………………………………… i
中文摘要………………………………………………………………...… ii
英文摘要………………………………………………………………..… iii
目錄……………………………………………………………………….. iv
1. 序論………………………………………………………………….…. 1
1.1. 轉糖鏈球菌 (Streptococcus mutans) 之形態與鑑定………………………... 1
1.2. 轉糖鏈球菌的分子生物學………………………………………………….… 2
1.2.1. 轉糖鏈球菌的基因體…………………………………………………... 2
1.2.2. 轉糖鏈球菌的Two component systems (TCSs)…………………........... 3
1.3. 轉糖鏈球菌與人類疾病的關係………………………………………............ 3
1.3.1. 齲齒……………………………………………………………………... 3
1.3.2. 感染性心內膜炎 (Infective endocarditis)……………………………… 3
1.4. 轉糖鏈球菌與環境壓力的關係……………………………………………… 3
1.4.1. 轉糖鏈球菌與有氧環境的抗衡…………………………………………. 4
1.4.2. 轉糖鏈球菌與其他環境壓力…………………………………………... 5
1.5. 轉糖鏈球菌的感染症………………………………………………………… 5
1.5.1. 致病菌與血液的互動…………………………………………………... 5
1.5.2. 宿主先天性防禦系統 (Innate immune system)…………………........... 6
1.5.3. 鏈球菌與吞噬細胞的互動………………………………………………. 8
1.6. 前人之研究與本論文的研究目的…………………………………………….. 8
2. 實驗材料與方法……………………………………………………….. 11
2.1. 菌株與質體……………………………………………………………………. 11
2.2. 藥品與材料……………………………………………………………………. 11
2.3. 細菌培養……………………………………………………………………… 11
2.4. 轉糖鏈球菌染色體DNA 的純化…………………………………………….. 11
2.5. 聚合酶連鎖反應 (Polymerase chain reaction, PCR)………………………… 12
2.6. 限制酶的切割……………………………………………………………..….. 12
2.7. 洋菜膠電泳分析………………………………………………………….…... 12
2.8. 洋菜電泳膠中DNA 的分離與純化………………………………………… 13
2.9. 轉糖鏈球菌RNA 的純化…………………………………………………….. 13
2.10. 轉糖鏈球菌基因體微陣列分析…………………………………………….. 14
2.11. 反轉錄聚合酶鏈鎖反應 (Reverse transcriptase polymerase chain reaction,
RT-PCR)……………………………………………………………………….. 16
2.12. 轉糖鏈球菌的轉形作用…………………………………………………….. 16
2.12.1. 轉糖鏈球菌受容細胞之製備………………………………………….. 16
2.12.2. 轉糖鏈球菌之轉形作用……………………………………………….. 16
2.13. 轉糖鏈球菌生長曲線之測定……………………………………………….. 17
2.14. 老鼠巨噬細胞細胞株 (Raw264.7) 之培養………………………………… 17
2.15. 老鼠巨噬細胞吞噬能力之分析…………………………………………….. 17
2.16. 流式細胞儀 (Flow cytometry) 分析老鼠巨噬細胞之吞噬能力…………… 18
2.17. 老鼠巨噬細胞殺菌能力之分析……………………………………………… 19
2.18. 反應性含氧物種 (Reactive oxygen species, ROS) 含量之測定…………… 19
2.19. 反應性含氮物種 (Reactive nitrogen species, RNS) 含量之測定…………. 19
2.20. In vitro 過氧化氫殺菌能力之分析……………………………………………... 20
3. 結果…………………………………………………………………… 21
3.1. 轉糖鏈球菌受血漿刺激後基因表現之微陣列分析………………………... 21
3.1.1. 轉糖鏈球菌中與氧化還原相關基因的表現…………………………... 21
3.1.2. 轉糖鏈球菌中two component system 的表現………………………... 22
3.2. 轉糖鏈球菌scnR 突變株的構築及生長曲線的測定………………………. 22
3.3. 以RNA 定量分析gcrR, scnR 及抗氧化相關基因在血漿刺激下的表現… 23
3.4. 老鼠巨噬細胞細胞株 (Raw264.7) 吞噬轉糖鏈球菌之能力分析…………….. 24
3.5. 老鼠巨噬細胞細胞株殺菌能力 (bactericidal activity) 分析……………….. 26
3.6. 轉糖鏈球菌抑制老鼠巨噬細胞細胞株所產生的反應性含氧物種………... 27
3.7. In vitro 過氧化氫殺菌能力分析………………………………………….….. 29
3.8. 轉糖鏈球菌經由scnR 調控以抵抗吞噬細胞毒殺作用之模式圖…………. 30
4. 討論…………………………………………………………………… 31
5. 圖表…………………………………………………………………… 37
Table I. Summary of gene categories with increased transcription in mid-exponential phase of S. mutans GS-5R strain cultured with plasma……………….. 37
Table II. Summary of gene categories with increased transcription in stationary phase
of S. mutans GS-5R strain cultured with plasma……………………... 38
Table III. The fold changes of selected genes of wild-type S. mutans and scnR deleted mutant strain in mid-exponential and stationary phase………………... 39
Fig. 1. Plasma-induced redox genes expression in mid-exponential phase and stationary phase S. mutans GS-5R strain……………………………… 40
Fig. 2. Schematic model for plasma-induced redox genes……………………... 41
Fig. 3. Construction of S. mutans two component sytem response regulator scnR deleted mutant by homologous recombination…………………….… 42
Fig. 4. Confirmation of microarray data by RT-PCR analysis………………….. 43
Fig. 5. S. mutans-Raw264.7 interaction………………………………………… 44
Fig. 6. Flow cytometry scatter plot analysis of Raw264.7 cells after phagocytosis of FITC-labled S. mutans. ………………………………………………... 45
Fig. 7. Survival of S. mutans by Raw264.7 killing………………………….…… 46
Fig. 8. Role of scnR in eliminating ROS in Raw264.7…………………………… 47
Fig. 9. Role of scnR against H2O2 killing…………………………........................ 48
Fig. 10. Proposed mechanism of two component system response regulator scnR-mediated protection against phagocytic killing…………………… 49
Appendix I………………………………………………………………………... 50
Appendix II……………………………………………………………………….. 50
6. 參考文獻……………………………………………………………….. 5
-arc-transitive digraphs
No full textAn -arc in a digraph is a sequence of vertices such that for each the pair is an arc of . There are several important differences between the study of -arc-transitive graphs and -arc transitive digraphs. For example, there are no 8-arc-transitive graphs of valency at least 8, while for every positive integer there are infinitely many digraphs of valency at least three that are -arc-transitive but not -arc transitive. In this talk I will discuss a solution to an old question of Cheryl Praeger about the existence of vertex-primitive 2-arc-transitive digraphs. This is joint work with Cai Heng Li and Binzhou Xia.Non UBCUnreviewedAuthor affiliation: The University of Western AustraliaOthe
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