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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The G1 cyclin Cln3p regulates vacuole homeostasis through phosphorylation of a scaffold protein, Bem1p, in Saccharomyces cerevisiae

Han, Bong Kwan 25 April 2007 (has links)
How proliferating cells maintain the copy number and overall size of their organelles is not clear. In the budding yeast Saccharomyces cerevisiae the G1 cyclins Cln1,2,3p control initiation of cell division by regulating the activity of the cyclin-dependent kinase (Cdk) Cdc28p. We show that Cln3p controls vacuolar (lysosomal) biogenesis and segregation. First, loss of Cln3p, but not Cln1p or Cln2p, resulted in vacuolar fragmentation. Although the vacuoles of cln3Δ cells were fragmented, together they occupied a large space, which accounted for a significant fraction of the overall cell size increase in cln3Δ cells. Second, cytosol prepared from cells lacking Cln3p had reduced vacuolar homotypic fusion activity in cell-free assays. Third, vacuolar segregation was perturbed in cln3Δ cells. Our findings reveal a novel role for a eukaryotic G1 cyclin in cytoplasmic organelle biogenesis and segregation. Furthermore we show that the scaffold protein Bem1p, a critical regulator of Cdc42p activity, is a downstream effector of Cln3p/Cdc28p complex. The Cdc42p GTPase is known to be required for vacuole fusion. Our results suggest that Ser72 on Bem1p is phosphorylated by Cdc28p in a Cln3p-dependent manner to promote vacuole fusion. Replacing Ser72 with Asp, to mimic phosphorylation at an optimal Cdkconsensus site located in the first SH3 domain of Bem1p, suppressed vacuolar fragmentation in cells lacking Cln3p. Using in vivo and in vitro assays, we found that Cln3p was unable to promote vacuole fusion in the absence of Bem1p or in the presence of a non-phosphorylatable Bem1p-Ser72Ala mutant. Furthermore, activation of Cdc42p also suppressed vacuolar fragmentation in the absence of Cln3p. Our results provide a mechanism that links cyclin-dependent kinase activity with vacuole fusion through Bem1p and the Cdc42p GTPase cycle.
2

Il centro e la periferia: Brescia e la sua provincia nelle carte del CLN Aprile 1945 luglio 1946 / The centre and the outskirts: Brescia and its province in the documents of the CLN (National Liberation Committee). April 1945 – July 1946.

ANNI, ROLANDO 17 February 2009 (has links)
La tesi riguarda le vicende del CLN bresciano dal 1945 al 1946 e la situazione politica e sociale di Brescia e della sua provincia, caratterizzata da gravi problemi e da una prassi democratica caratterizzata da contrasti. / The thesis is about the occurrences in the National liberation Committee of Brescia from 1945 to 1946 and the situation of Brescia and its province, that suffered, at the beginning of its democratic age, serious economic and social problems.
3

連動式債券之評價與分析─信用連結債券及CMS連結債券

陳宗佑 Unknown Date (has links)
由於近幾年來連動式債券的盛行,要如何在眾多的標的中選取符合自己需求的對投資人來說越來越重要,本論文特別選了目前市場上當紅的兩種連動債來作評價與分析,一是信用連結債券,另一是CMS連結債券。 評價信用連動債券所使用的利率模型為Hull-White利率三元樹模型,而在考量信用風險時則是運用Li(1998)的方法,以市場上公司債的信用價差建構出信用曲線,再由信用曲線轉換成信用折現因子。最後便可依照債券的付息型態,使用利率三元樹與信用折現因子求得信用連動債券的價格。再針對各個參數進行敏感度分析,最後發現殖利率曲線的變動對債券價格影響最大,尤其是對逆浮動連結利率的債券而言。其次是利率波動度對債券價格的影響。 評價CMS連結債券所使用的方法是LIBOR市場模型,在設定好遠期利率的動態過程後,經由蒙地卡羅法模擬出各個時點的遠期利率,再利用交換利率(Swap Rate)與遠期利率間的轉換公式求得各個時點的指標利率,用以計算各付息日的配息率,再將各個時點的配息與本金以模擬出來的利率折現後,便可得到期初的債券價格。模擬了一萬次後,再將結果平均即是該CMS連動債券的理論價格。再針對各個因素進行敏感度分析後可發現,期初時的殖利率曲線的變動對債券價格影響最大,因為其一方面會影響折現率,另一方面還會影響配息的比率。 值得注意的是,所評價的兩種債券皆附有贖回條款,而就CMS連結債券而言,此條款的設定異常重要,若沒有此條款,發行商將因配息率設定的過高而受到鉅額的損失,而在設定了贖回條款後,投資人就會因債券可被贖回而喪失高報酬的機會,並且造成持有期間的縮短。
4

連動式債券設計個案研究-固定期限交換利率利差連動與信用連結債券

莊筑豐 Unknown Date (has links)
連動式債券已成為目前市場上最熱門的投資工具,標榜著高受益的條款下,常隱含著投資人所不瞭解的風險,利用理論的模型套用在實務商品上,可以令人更清楚認識複雜化的金融衍生性商品。本文在Libor市場模型與Hull-White利率模型的架構下,利用數值方法評價分析最常見的兩種連動式債券-固定期限利率交換利差連動債券與信用連結債券。 Libor市場模型直接拿取市場上可觀察到的遠期Libor利率做為模型的標的,有良好配適目前利率期間結構的優點。利用此模型為出發,校準出波動度期間結構,以蒙地卡羅模擬法來評價固定期限利率交換利差連動債券。由評價結果可量化分析出連動式債券內含的選擇權與零息債券價值為何,探討發行商的發行策略與投資人的風險來源。 繼股權、利率連動式商品之後,未來金融商品的連動標的將進入信用風險的階段。以公司債的市場資料建立出一條信用風險曲線(Credit Curve),最能夠反映出當時市場上大多數人對於未來發生違約事件的預期。在假設利率市場風險和標的公司信用風險是獨立的前提下,將這條曲線和以Hull-White利率模型為基礎建立的利率三元樹與路徑函數結合,便可以適當地評價信用連結債券的價值。最後,求算債券內含的信用違約交換價值,對發行機構的策略與投資人的風險作分析。
5

信用及利率衍生性商品之評價與分析--以信用連結票券及利率交換為例

林淳瑜 Unknown Date (has links)
近年來由於金融自由化的發展,台灣已陸續開放新金融商品,除了股權相關的新金融商品之外,也陸續開放利率相關的新金融商品,如新台幣利率交換、新台幣利率選擇權、債券遠期交易、債券選擇權等。在信用衍生性商品市場方面,我國銀行從2002年底開放承做信用衍生性商品,目前正準備開放證券商承做。隨著金融國際化及自由化,未來將會從國外引進更新穎的金融商品,使金融市場更為完備。 本文以Hull – White利率模型及LIBOR市場模型為架構,藉由數值方法評價分析兩個衍生性商品──信用連結票券及利率交換。首先在信用連結票券方面,運用Li(1998)建立信用價差曲線(Credit Curve),將之應用至Hull – White三元樹,評價信用連結票券之價值,並作敏感度分析與避險參數分析。其次在利率交換方面,由於投資人端連結「雪球型」的支付型態,為路徑相依商品,故使用LIBOR市場模型以蒙地卡羅模擬法(Monte Carlo)進行評價與分析,再進行發行者損益兩平分析及情境分析。最後針對兩個商品的評價結果作結論,分析發行者及投資人的利潤及避險,並給予後續研究者模型改進之建議與方向。

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