全國中小學科展

二等獎

Quantitative Analysis of Organism Growth Using Fractal Dimension Statistics

Cultures of bacteria were analyzed using fractal geometry and statistics to provide a method for predicting organism growth, paving the way for a better design of treatment drugs. Images of three cultures of isolated Bacillus subtilis were taken at time intervals of two to three hours for eight days. The images were processed using the IDOLON program and quantitatively described using three statistical formulas: fractal dimension D, Renyi dimension and Hausdorff-Besicovitch dimension. The three variables were integrated to compute the maximum of the distribution and were used as coordinates for a 3-dimensional graph f. A 2-dimensional graph g containing the maximum of a distribution under time analysis was also constructed. Topological properties of the graphs, including slope, direction and area were used to determine the interrelationship of the three fractal values. The two graphs, described as φ - : X -? P1 where X is the smooth algebraic assimilation of the four variables under time analysis, was extended using Java. A computer-aided prediction model of the graphs f and g were made which combined the topology of f and g at infinity. The computed fractal values showed the existence of a fractal pattern in the growth of Bacillus subtilis with fractal dimension ranging from 0.900 to 4.000, indicating a linear iteration. This was supported by the values of the Renyi dimension, which showed a horizontal growth pattern of the bacterial cultures, establishing the growth of the bacteria to be inclined to go towards the North East direction. There was consistency in the computed fractal values, maximum of distribution and topographical computations of all three cultures which also indicated the existence of a pattern of growth which could be extended to tinfinity, thereby allowing prediction of the direction and rate of growth of the bacterial colonies. The fractal patterns in the growth of bacteria, in this case Bacillus subtilis, yielded the direction and rate of growth of the bacteria as shown by the analysis of the fractal patterns and statistical values, showing that the growth of harmful organisms can therefore be predicted, making it possible to improve on the design of drugs for the control of perilous cells. By preventing the growth of insidious cells, the potential effects of virulent organisms may be avoided, and treatment may be made more possible.

微陣列基因分析法探討心肌細胞在機械性展延下的基因表現

高血壓所誘發的機械性展延是造成心肌肥大的基本因子,本實驗即藉由微陣列基因分析法同時大量的分析機械性展延所造成心肌細胞的基因表現。將新生鼠的心肌細胞施以 20﹪的機械性展延,抽取其 mRNA製作成 cDNA 探針與現成的 cDNA 晶片進行雜漬反應 (此晶片上包含了 480個如訊息傳遞、控制細胞生長週期、細胞骨架等的已知基因),在眾多有因為機械性展延而造成基因表現差異的基因中,我們選擇了 eNOS 基因(內皮細胞 NO合成?)進行西方墨點法及 NOS活性和 NO 產生量測定的實驗,進一步證實 eNOS 的基因表現量的確是增加的,此一結果與微陣列基因分析所得之結果不謀而合。 Mechanical stretch induced by high blood pressure is an initial factor laeding to cardiac\r hypertrophy. The use of cDNA microarrays has made it possible to simultaneously analyze\r stretch-induced gene expression in cardiomyocytes. Neonatal rat cardiomyocytes were cultured on\r malleable silicone dishes and were stretched by 20%. We compared the transcript profiles of\r cardiomyocytes under mechanical stretch for 60 minutes by hybridization of cell-derived cDNA to\r DNA probes immobilized on microarrays. The microarrays contained probes for 480 known genes\r including signal transduction, cell cycle regulators, cytoskeleton and cell motility, and so on. Eighteen\r genes were indentified that showed significantly differential expression in response to mechanical\r stretch in cardiomyocytes. Of the represented genes expressed, endothelial nitric oxide synthase (eNOS)\r genes was the most interesting one. Northern blot and western blot analysis further quantified the\r expression of eNOS gene. Mechanical stretch also increased constitutive NOS activity and NO\r production. Our results indicate that mechanical stretch induces eNOS gene expression thus increases\r constitutive NOS activity and NO production in cardiomyocytes.

Investigation of phytoremediative ability of macrophytes and a design of a phytofiltration system for Singapore’s waterways

"Nitrates and phosphates cause eutrophication when present in high concentrations.\r This project aims to employ macrophytes to reduce such macronutrients in water bodies via growth and kinetic studies, which is a unique fusion of methodologies. It also involves a novel design and analysis of several enclosure prototypes to introduce macrophytes into waterways and their effects on the waterway’s ability to convey storm water rapidly away from flood-prone areas.\r Tropical macrophytes (emergent macrophytes Typha angustifolia and Cyperus haspan, submerged macrophytes Hydrilla verticillata and Cabomba aquatica, floating macrophytes Lemna minor) were grown in simulated wastewater with high nitrate and phosphate concentrations. Analysis of the growth and uptake kinetics of the macrophytes showed a correlation between high growth rate and high nitrates and phosphates uptake. C. aquatica had the highest uptake rate for nitrates and phosphates as well as the highest growth rate of 6.11 ± 1.2 % day-1 . The remaining macrophytes were proven to exhibit good phytoremediative properties, with emergent macrophytes C. haspan and T. angustifolia having great affinity (as indicated by a low Km value) for phosphate and nitrate respectively. An analysis of the phytoremediative abilities of each macrophyte was done to provide recommendations for growth in different aquatic areas.\r A total of eight nettings, made from different materials-linen and plastic, and pore sizes were used to design the enclosure prototypes. These enclosures possess a metal skeletal structure for greater stability. Results show that a combination of 2 different nettings provided the best trade-off between ensuring that the macrophytes were contained within the enclosures and minimising the enclosure’s impact on the flow velocity of the waterways. Enclosures could then be attached to existing infrastructure like the float booms as a platform for large scale phytoremediation locally."

表面磨損之自動警告系統

在機械系統中,物件表面常產生磨損,但重要物件的磨損將會危及系統的操作及安全。本研究建立了表面磨損自動偵測警告系統,該系統包含監測系統、無線射頻資料讀取器、被動式無線射頻識別標籤(tag)、及電磁波隔離層等,並採”故障觸發”之方式運作。亦即在物件之表面下特定深度埋設有被動式無線射頻識別標籤,但該標籤外層覆有一層隔離層可隔絕該射頻資料讀取器之電磁波。 當物件表面尚未被磨損到特定深度前,讀取器之電波無法穿透電磁波隔離層而激發無線射頻識別標籤,因此無法讀到識別標籤之信息,系統將判定物件磨損狀況良好。等該物件過度磨損時,會把該電磁波隔離層磨除掉,使讀取器之電波可激發無線射頻識別標籤,而讀取到識別標籤內含之信息,系統因此可判別哪一個物件已有嚴重磨損之狀況,而自動提出警告信號。由於使用被動式識別標籤及故障觸發方法,本系統具有體積小、免電池、免維護、成本低、誤判率低等優點。測試結果以車輛輪胎的磨損為對象,證實本系統可以即時有效的偵測到車胎之過度磨損,保障行車之安全。

阿拉伯芥AtYAK1 基因5'UTR 中的開放讀序框(uORFs)對基因表現調控之探討

在模式植物──阿拉伯芥(Arabidopsis thaliana)中,AtYAK1(Arabidopsis thaliana Yak1-related protein kinase)是目前發現唯一屬於DYRK(Dual specificity Yak1-Related protein Kinase)的蛋白激?。雖然之前研究已證明,不同物種之DYRKs 和細胞的生長與發育過程有關。然而,其在植物中的生理功能卻尚未被明確地研究報導過。在先前的研究中,為瞭解AtYAK1 在阿拉伯芥內作用之位置,前人選取AtYAK1 基因ATG 上游約2.5 kb 的序列(Upstream Element, 2.5KUSE)建構至一含有GUS(β-glucuronidase)報告基因的質體中,並轉形至阿拉伯芥,進行GUS 組織染色分析。但在初步結果中,並沒有在轉殖株觀察到明顯的GUS 表現。進一步分析,我們發現在2.5KUSE 序列末端約0.5 kb 的5’非轉譯區(5’untranslated region, 5’UTR)中,有四組開放讀序框(Upstream Open Reading Frame, uORF)。有趣的是,許多研究也顯示,uORFs 會影響轉譯過程中的再起始(re-initiation)作用而調控該基因的表現。另一方面,前人亦透過構築好的2KUSE 轉殖株(即不含有5’UTR)進行上述GUS 實驗。結果發現,此2KUSE 轉殖株的GUS 表現非常顯著。本實驗即要瞭解AtYAK1 的uORFs 是否也會影響其蛋白質的合成。首先,我們以點突變的方式將四組uORFs 中之ATG 換成TTG,目的為構築不含有uORFs 之5’UTR(mutated uORFs, ΔuORFs)。在進行原生質體短暫表現分析法(protoplast transient assay)及GUS 組織染色分析後,將結果與含有uORFs 的結果作比較:當缺乏uORFs 後,其3’端報告基因的表現量確實比原來顯著。綜合以上,我們認為此uORFs 對於AtYAK1 蛋白質之表現佔有相當重要的影響地位。最後,我們對5’非轉譯區是否存在開放讀序框進行阿拉伯芥全基因組分析,相關結果亦於本研究報告中分析討論。AtYAK1(Arabidopsis thaliana Yak1-related protein kinase)is the first DYRK(Dual specificity Yak1-Related protein Kinase ) family member identified in the model plant ─ Arabidopsis thaliana and exists as one copy gene in Arabidopsis. Previous studies showed that many eukaryotic DYRKs are involved in regulating the growth and development of cells. However, the study of AtYAK1 in Arabidopsis is lacking to date. In order to understand where AtYAK1 expresses and functions in plants, a 2.5 kb fragment which is located upstream from the major ATG of AtYAK1(termed Upstream Element, 2.5KUSE)was previously constructed to drive the expression of a reporter gene, GUS(β-glucuronidase), in transgenic Arabidopsis. Much to our surprise, no GUS expression signal could be detected in such transgenic plants. When further analyses were performed, we found that there are four upstream open reading frames (uORFs) in the 5’untranslated region ( 5’UTR ) within the 2.5KUSE. Many studies indicating that the uORFs can regulate the translation of downstream ORF encoding the major gene product through the procedure of translation re-initiation. This action represents a mode of translational regulation for gene expression. Indeed, GUS activity could be readily detected in transgenic plants expression 2KUSE::GUS, a construct lacking the 5’UTR of AtYAK1. In this study, I have tried to elucidate whether the uORFs of AtYAK1 can regulate the translation of the downstream major ORF. First, in order to construct a 5’UTR fragment of which uORFs have been mutated(ΔuORFs), we apply site-directed mutagenesis to substitute ATG with TTG for the four uORFs and examine the expression of GUS driven by this mutated 2.5KUSE. After analyzing the results in both Arabidopsis protoplast transient assay and transgenic Arabidopsis, stronger expression of reporter genes in both systems were observed when the four uORFs were mutated. We have also confirmed that, in transient expression system, the increase of reporter gene activity was not due to the excess accumulation of the corresponding mRNAs. Rather, it is the four uORFs which play an important role in negatively regulating the translation of AtYAK1, possibly via inhibiting the translation re-initiation of major ORF. A genome-wide examination of uORFs in all Arabidopsis genes was also performed to assess the possible contribution of uORF in regulating gene expression.

動物類固醇激素對植物的影響

本研究以結構穩定、能溶於水,並會影響人體生長發育的固醇類激素──副腎上腺皮質激素作為探討對象,嘗試了解此類之類固醇類激素對植物的生長發育是否有影響。結果發現無論是雙子葉的豆科植物或是單子葉的禾本科植物,其根、莖、葉的生長皆會受到激素的抑制,且出現激素濃度越高,抑制情形越顯著的情形。此外,統計學的結果顯示,類固醇會蓄積在植物體內,造成累積性的抑制作用,此現象和動物使用過量類固醇類激素時產生之副作用十分相似。 The present study investigates the effect of cortical sterile on the growth of plants. The results show that it has effect on both dicotyledons and monocotyledons in the roots, stems and leaves. It is also shown that the higher the concentration, the more marked suppression of their growth. Statistical analyses suggest a cumulative effect, which has also been found of overdoes of cortical sterile on animals.

Going Dotty: The Distribution and Effects of Rust on Highbush Cranberry

Purpose Every fall, I collect highbush cranberries (Viburnum edule) to make jelly. In 2012, for the first time, I observed highbush cranberry leaves covered in striking patterns of raised purple dots (telia) caused by the pathogenic rust fungus Puccinia linkii. I investigated the distribution and effects of this rust for several reasons: little is known about P. linkii, highbush cranberries are an important food source for wildlife and people, and foliar pathogens may increase with climate change in sub-boreal forests. First, I investigated the patterns of telia within plants. Second, I compared the variation in infection severity among plants, hypothesising that younger plants, those in dense populations, and those in low-elevation riparian areas would be most infected. Finally, I studied the effects of P. linkii on its host, hypothesising that highly infected plants would produce fewer berries and produce berries with less sugar, and that infected leaves would die sooner. Procedures This study investigated P. linkii in mixed coniferous-deciduous forest sites near Smithers, British Columbia. I marked a total of 41 randomly-selected focal V. edule plants in four sites. To examine within-plant patterns of infection, I photographed four leaves of each plant and used a graphic analysis program to examine the size, density and coverage of telia. To assess among-plant patterns, I compared infection severity (5 classes of telia coverage), to three ecological variables: host density within 5m, position on a moisture gradient, and plant maturity. To investigate the effects of P. linkii on its host, I compared infection severity to the number of berries produced, the proportion of malformed and infected berries, and the sugar content of mature berries as measured with a handheld refractometer. I measured leaf mortality in fall. Results P. linkii produced a characteristic pattern within each plant: higher leaves consistently had fewer but bigger telia than lower leaves. Across sites, plants were significantly more infected in areas of high host density. Within sites, young plants and plants and in moister ecosystems were significantly more infected (increases of 1.1 ± 0.2; F1,128=44.8, P

Equtatetor-新一代智慧型數學處理器

此研究的目的是要設計出一套完整編輯顯現數學式、加以計算,並求出解的一套方法與成品。而這項工作的執行者,在此稱之Equatetor 。一般的數學式子,若要計算的話,普通的計算機是不足夠的。原因是它們沒有辦法表現出數學式的「原貌」,例如分號、指數、函數、根號等數學符號混在一起時的情況。於是,我便擬定了一個研究,希望設計出一套更方便且實用的方法。換句話說,我要設計出一個功能強大的工程計算機程式。其中,自然牽扯到數學式子的顯現方式(以MathML 實現),以及計算機科學的演算法及資料結構。我主要的目的有四:(1) 顯示數學式(2) 方便編輯數學式(3) 計算數學式(4) 處理可以以不同形式輸出解答的計算(如輸出分數、根號、函數解等)。研究結果中,成功地運用XML 中的MathML 與二分逼近分數等演算法及若干資料結構,達到了以下實用的幾點:(1) 結構化的數學式編輯(2) 完整地顯示數學式(3) 正確運算並輸出運算式的答案(4) 提供一般數學形式之解(非小數之解);The object of this study is to design a method and processor which is able to edit, display a mathematical expression representing a number, calculate and output the answer. The executor of this task is called Equatetor. Normal calculators are not adequate for this kind of task. The main reason is that they can’t reveal the original expression, such as fractions, radicals, exponents or mathematic functions. Therefore, a simple and convenient method is needed. To perform the possible way of handling those tasks, a computer program has been written. Several techniques were used, such as MathML, computing algorithms, data structures, and so on. Following are main purposes: (1) Displaying mathematical expressions. (2) Editing mathematical expressions simply. (3) Calculating mathematical expressions. (4) Outputting the answers(in different expressions). And the achievements:(1) Structured methods of editing of mathematical expressions. (2) Displaying mathematical expressions completely. (3) Calculating mathematical expressions precisely. (4) Offering answers in different expressions.

淘氣精靈(ELVES)高空放電現象性質探討

ELVES (Emissions of Light and VLF perturbation due to EMP Sources) is a transient luminous phenomenon of ionosphere induced by the electromagnetic pulse of lightning. In this report, we use the data of ISUAL science payload of FORMOSAT-2 to investigate the luminosities and the stepped-leader signals of the different kinds of ELVES.淘氣精靈全名Emissions of Light and VLF perturbation due to EMP Sources簡稱ELVES,為閃電的電磁脈衝波引發電離層短暫發光的現象,本研究是分析福爾摩沙衛星二號上科學酬載ISUAL的光度資料,以探討淘氣精靈類型與光度訊號強度以及閃電前導訊號的關係。

隨機物體轉移過程的實驗時間之初探

有二系統A和B,A中一開始有2k個物體,,B中有0個物體。在一個單位時間內,兩系統可以互相轉移最多一個物體。當B中物體的個數為 i-1,i∈{1,2,...,k+1},我們稱其為狀態 i,從狀態1﹝初態﹞開始計時,到達狀態 k+1﹝相同態﹞便即刻停止實驗,經過之時間為一隨機變數T,稱之為實驗時間。問當兩個系統的物體數剛好相等時,經過的實驗時間之分佈為何?本文將以上述問題為核心,分別探討不同條件下系統的實驗時間所反映出來的現象,如機率、期望值、變異數等等。 Define two systems, A includes 2k objects, and B has none. They can transfer at most one object from one system to another in a time unit. When the number of objects in B is i-1, i∈{1,2,...,k+1} , we say the system is at state i. As soon as system transfer form state 1 ( initial state ) to state k+1 ( the same state ), the experiment stop. Random variable T, called the experiment time, is the time before stop. What would be the distribution of the experiment time if all systems have the same amount of objects within? This article will focus on the described question and discuss what property the experiment time of the system under various conditions has, such as probability, mean, and variance.