Global Observations of the 630-nm Nightglow and Patterns of Brightness Measured by ISUAL

This study investigates the distributions and occurrence mechanisms of the global local-midnight airglow brightness through FORMOSAT-2/ISUAL satellite imaging observations. We focus on the OI 630.0 nm nightglow emission at altitudes of ~250 km along equatorial space. The database used in this study included data from 2007 to 2008 under solar minimum conditions. The data were classified into four specified types in the statistical study. We found that the occurrence of equatorial brightness was often in the vicinity of the geographic equator and mostly at equinoxes with a tendency to move toward the summer hemisphere as the season changes. Conjugate brightness occurring simultaneously on both sides of the geomagnetic equator was observed predominantly in the northern winter. Furthermore, midnight brightness appeared to have lower luminosity from May to July. We suggest that the global midnight brightness associated with the locations and seasons was the result of several effects which include the influence of the thermospheric midnight temperature maximum (MTM), summer-to-winter neutral wind, and ionospheric anomalies

thermally-induced fibrillation of bovine serum albumin

目前研究發現，人體中有超過二十種以上的蛋白質會因為發生錯誤折疊而形成類澱粉纖維沉積，甚至進一步導致疾病發生。目前雖不乏針對此一現象之研究，但詳細之機制及形成原因等仍有待釐清。 本研究利用牛血清蛋白作為目標蛋白質，探討其在不同酸鹼值環境下，因加熱聚集形成類澱粉纖維的機制與其結構之變化。在實驗中發現，中性 (pH 7.4)及弱鹼性 (pH 9.0)環境下之牛血清蛋白較容易生成類澱粉纖維，且在加熱變性的過程中具有相當類似的結構變化；甚至在pH值更高的環境下(pH 10.0)，仍有少量的類澱粉纖維形成。然而在酸性條件(pH 2.0)下，卻不利牛血清蛋白的聚集，即便是在70oC的高溫下仍然無明顯的聚集現象發生。 此外，由各種光譜分析結果中可發現，牛血清蛋白在加熱變性過程中，不同酸鹼值下也呈現不同的破壞程度，其中以酸性條件(pH 2.0)及鹼性條件(pH 10.0)下最為明顯。由phase diagram的分析可以看到，隨溫度上升的過程中，除酸性條件外，其餘中性及鹼性環境下之牛血清蛋白均會經過數個結構轉折點，也就是有中間產物(intermediates)的形成，由此可知此中間產物應為形成類澱粉纖維之必經途徑之ㄧ。 藉由ligand quenching的實驗，可針對牛血清蛋白的各個domain之結構變化進行研究。其中發現酸性條件下之牛血清蛋白其domain I及domain II之聯結在室溫下便已受到相當程度的破壞，也因此影響了位於domain I上裸露的Cys34，無法順利與其他牛血清蛋白分子彼此透過雙硫鍵進行鍵結，不利於形成聚集體。 然而在中性及鹼性條件下，即便升溫至70oC時，該區域之結構仍可維持一定的穩定性，因此易透過雙硫鍵鍵結形成聚集體。 藉由本論文所進行之研究，將有助於進一步了解牛血清蛋白受酸鹼值以及受高溫影響所發生的聚集現象及結構變化有何差異，並且更加深入的探討牛血清蛋白形成類澱粉纖維時之機制。More than twenty different human proteins can fold abnormally into amyloid fibril deposits which may lead to lethal diseases. Despite extensive investigations on amyloid fibril formation, the detail of molecular mechanism remained rather elusive. The current study is aimed at exploring the effect of thermal induced aggrefation of BSA samples at various pH values. Via numerous spectroscopic techniques and transmission electron microscopy, our results showed that bovine serum albumin samples at neutral condition (pH 7.4) and alkaline conditions (pH 9.0, and pH 10.0) can form amyloid fibril at 70oC. However, no obvious aggregation occurred at acidic condition (pH 2.0). In the phase diagram analysis, we find several transition points through the heating processes except for BSA samples at pH 2.0. Our results demonstrate that BSA samples will form intermediates during the fibrillation processes. Moreover, we use several ligands to further probe the structural changes of different domains. It could be concluded from our results that the breakage of the inter-domain between domain I and domain II prohibit the diamerization of BSA molecules and consequently inhibit the aggregation process. According to the results from this study and the literature, we suggest that the fibrillation processes are facilitated by disulfide/thiol exchanges at 70oC at neutral and alkaline conditions. In addition, the breakage of inter-domain at acidic condition may suppress the fibrillation of BSA samples. The outcome from this work may aid in comprehending the molecular mechanisms of fibrillogenesis of BSA at various pH conditions.摘要 IIIbstract V一章 序論 1二章 文獻回顧 2-2 蛋白質結構 5-3 穩定蛋白質結構之作用力 9-4蛋白質的構形 11-5蛋白質的摺疊 12-6蛋白質聚集體 14-7聚集體的產生 15-8類澱粉纖維聚集體 17-9蛋白質的變性 20-10牛血清蛋白(bovine serum albumin) 22-11 牛血清蛋白與ligand之結合能力 25-12酸鹼值對牛血清蛋白之影響 28-13加熱對牛血清蛋白之影響 30-14 偵測蛋白質形成類澱粉纖維之方法 39-15 偵測蛋白質結構改變之方法 40三章 研究動機 48四章 實驗儀器、藥品與步驟 49-1 實驗裝置 49-2 實驗藥品 50-3 實驗方法 52五章 實驗結果與討論 61-1 室溫下不同pH值對於牛血清蛋白結構之影響 61-1-1 利用自身螢光光譜分析牛血清蛋白之三及結構變化 61-1-2 利用圓二色光譜分析牛血清蛋白二級結構 63-1-3 利用ANS螢光圖譜偵測牛血清蛋白疏水性區域之變化 65-1-4 利用hemin quenching偵測牛血清蛋白之結構變化 66-1-5利用chloroform quenching偵測牛血清蛋白之結構變化 68-2 在70oC下偵測牛血清蛋白於不同酸鹼環境中fibril的形成與結構變化 70-2-1 利用ThT 螢光光譜分析牛血清蛋白在70oC下fibril生成之情況 70-2-2 利用圓二色光譜分析牛血清蛋白在70oC下之二級結構變化 71-2-3 利用穿透式電子顯微鏡 (TEM)直接觀測牛血清蛋白形成之fibril 75-2-4 利用ANS偵測牛血清蛋白加熱變性後的疏水性區域結構變化 78-2-5 利用動態光散射(DLS)觀察牛血清蛋白分子之聚集現象 80-3 隨升溫過程偵測牛血清蛋白在不同酸鹼環境下fibril的形成與結構變化 86-3-1利用ThT 螢光光譜分析牛血清蛋白在升溫過程中fibril生成之情況 86-3-2利用自身螢光光譜分析牛血清蛋白在升溫過程中三級結構之變化 88-3-3 利用圓二色光譜偵測升溫時牛血清蛋白之二級結構變化 94-3-4利用phase diagram探討升溫時牛血清蛋白的階段性結構變化 98-3-5 利用chloroform quenching偵測升溫時牛血清蛋白之結構變化 102-3-6利用ANS偵測升溫時牛血清蛋白之結構變化 106-3-7 利用hemin quenching偵測升溫時牛血清蛋白之結構變化 107-3-8 利用SDS-PAGE蛋白質電泳偵測牛血清蛋白分子聚集情況 111六章 結果討論 117-1 於不同酸鹼條件下對牛血清蛋白進行熱誘導變性 117-1-1 不同酸鹼環境對牛血清蛋白結構之影響 117-1-2 熱誘導牛血清蛋白結構變化 118-2 牛血清蛋白之熱誘導類澱粉纖維生成機制 132七章 未來展望 133考文獻 134錄 143錄A 牛血清蛋白濃度校正曲線 143錄B 圓二色光譜數據計算 144錄C 相圖分析方法理論 145錄D 利用拉曼光譜偵測牛血清蛋白結構之變化 147錄E ThT螢光光譜實驗fitting結果 151錄F Acrylamide quenching 15

Import preference change and its impacts on the effects of trade liberalization policy

In the recent years, the import shares of intermediate inputs for Taiwan’s manufacturing sector and that of household manufacture consumption continues to rise even with the relative import price increase. This phenomenon may be due to the global trend of production outsourcing, the increase of imported product variety and the persistence of trade barriers, which altogether are called the imported preference change in this article. But most of the macroeconomic models did not consider the change of import preference in their import demand and therefore may generate biased empirical results. By establishing a single country Computable General Equilibrium (CGE) model including the import preference factor, this paper first calibrates the change of import preference of the sample period, then applies the model to the simulation of a trade liberalization policy. By comparing the empirical results with and without the concern of the import preference change, the bias from neglect of the preference change may be revealed

Import preference change and its impacts on the effects of trade liberalization policy

In the recent years, the import shares of intermediate inputs for Taiwan’s manufacturing sector and that of household manufacture consumption continues to rise even with the relative import price increase. This phenomenon may be due to the global trend of production outsourcing, the increase of imported product variety and the persistence of trade barriers, which altogether are called the imported preference change in this article. But most of the macroeconomic models did not consider the change of import preference in their import demand and therefore may generate biased empirical results. By establishing a single country Computable General Equilibrium (CGE) model including the import preference factor, this paper first calibrates the change of import preference of the sample period, then applies the model to the simulation of a trade liberalization policy. By comparing the empirical results with and without the concern of the import preference change, the bias from neglect of the preference change may be revealed

The attitudinal and behavioral impact of brand-centered human resource management

Purpose The purpose of this paper is to investigate the effects of brand-centered human resource management (HRM) on employees’ person–brand fit, brand commitment (BC) and brand citizenship behavior (BCB). In addition, the paper tests effects of BCB on customer satisfaction and citizenship behavior. Design/methodology/approach Data were collected from managers, front-line employees and customers of 22 international tourist hotels in Taiwan. Hierarchical linear modeling was used to investigate relationships between variables. Findings Multilevel results reveal positive connections between brand-centered HRM and BCB, mediated by person–brand fit and BC. Positive relationships were also found between BC and BCB, person–brand fit and BCB; BCB and customer satisfaction; and between customer satisfaction and customer citizenship behavior. Research limitations/implications When employees’ personal values are consistent with brand values, employees will feel a closer connection to the brand and be more willing to dedicate themselves to brand-related activity. The model developed here can be tested in different cultures to ascertain the generalizability of the findings to Western contexts. Practical implications Support is provided for the positive effects of brand-centered HRM when employees internalize brand values as their own personal values. Hotel managers should ensure that employees are highly committed to the brand values and willing to deliver services to customers accordingly. Originality/value The paper provides measurement developments for person–brand fit and BC and deeper understanding of how brand-centered HRM can lead to positive changes in customer behavior

A multilevel study of brand-specific transformational leadership: employee and customer effects

In this study, we examine the effects of brand-specific transformational leadership (TFL) on the brand-related attitudes and behaviors of employees and customers. We test relationships between brand-specific TFL and employees’ brand commitment and brand citizenship behavior and then the resulting effects on customer citizenship behavior and customer-based brand equity. Data from 18 international tourist hotels in Taiwan, including 136 supervisors, 268 employees and 221 customers, were analyzed using hierarchical linear modeling to investigate the multilevel relationships. Support is found for all hypotheses. The findings advance understanding of brand-specific TFL and the effects this leadership style can have on the brand-related attitudes and behaviors of both employees and customers

Corporate branding, brand psychological ownership and brand citizenship behaviour: multilevel analysis and managerial implications

Brand psychological ownership can be defined as a psychological experience producing positive brand attitudes and brand cognitions, such as a feeling of ownership towards a brand, and altruistic spirit towards brand-related activities. Building on, and extending the work of Chang. Chiang and Han (2012), this paper investigates the antecedents and consequences of brand psychological ownership. A multilevel approach is taken to investigate the relationship between three major constructs related to branding efforts: brand psychological ownership, corporate branding and brand citizenship behaviour. In the individual analysis, brand psychological ownership was found to have a positive effect on brand citizenship behaviour. In the multilevel analyses the results show that corporate branding has a positive effect on brand psychological ownership and brand citizenship behaviour. As a result, leaders and general managers can use corporate brand building as a tool for employee motivation and even cultural change. Organisational-level brand citizenship behaviour is found to positively affect brand equity. Furthermore, brand psychological ownership mediated the relationship between corporate branding and brand citizenship behaviour in the multilevel relationship. The paper discusses these findings, their contribution to current literature and their implications for future research and management development