全國中小學科展

2011年

植物miRNA的特殊長度─生成與演化

基因靜默為各種生物普遍擁有的調控機制,是以microRNA (miRNA)和Dicer-Like (DCL)與Argonaute (AGO)等數個蛋白質來完成。在植物,miRNA大多是由DCL1截切前驅物所產生,因DCL1具有21-nt 分子尺,所以絕大多數miRNA的長度為21nt。然而,其他特殊長度卻也有一定比例的存在,且可能有特殊的功能。最新研究發現22nt的miRNA可誘發更多的小片段干擾核酸來造成大量而強烈的基因靜默;然而,一般21nt的 miRNA卻無此功能。本研究以生物資訊的方法分析大量資料庫,並以分子生物學實驗佐證,探討特殊長度miRNA的生成、功能與演化。結果發現,20nt的miRNA可藉由對稱性與非對稱性縮短產生,這是RNA結構研究的新發現。功能上,20nt的miRNA與生長發育有關,22nt的miRNA則多與逆境反應有關;在演化上,長度20nt的miRNA呈現高保守性,而大部分22nt的miRNA則呈現高度物種專一性,為演化快速的特殊長度。

Transformer Robot

Nicholas’s project is a transforming robot, who he has named Reggie. He's about a foot tall and can transform from a biped into a vehicle and vice versa?\r Reggie has been Nick’s project for just under a year now, mainly working on him in technology classes. He operates without physical connection to anything else, so everything he needs from micro controllers to power is stored somewhere on Reggie’s body?\r Reggie is controlled through a programmable Arduino board (programmed in C++) that is connected up to a motor driver, for controlling the two driving motors and an SSC-32 servo controller for controlling the 14 servos via serial port. The Arduino uses the SSC-32 to coordinate the servos movements using pre-programmed sets of movements stored in procedures in order to complete all actions.\r All the parts were produced on a 3D CAD system to begin with, as well as the robot as a whole, although the design did change drastically over the course of its construction and now is considerably different from the original design as there were many problems and complications ranging from space to torque issues that called for a change in design.\r Most of the parts were from the servo erector set from lynx motion, although some of them were used in the way they were intended to and most of them were modified slightly. Some parts Nick manufactured himself either on a rapid prototyping machine, a lathe or milling machine and sometimes a combination of them or even high temperature soldiering?\r Currently Reggie is capable of driving and standing up and is currently radio controlled. He will eventually be capable of walking and modifications to allow him to (such as stronger leg servos) have been made to facilitate that, but it is possible more may have to be made.

聚對苯二甲酸乙二醇與聚乳酸共混材料之降解研究

本實驗目的在於嘗試降解傳統塑膠材料。實驗中選用極為常見的傳統塑膠,聚對苯二甲酸乙二醇ploy ethylene terephthalate (PET),與生物可分解材料,聚乳酸poly lactic acid (PLA),將兩者以不同比例物理性混摻,並以豬胰線脂肪酵素Lipase from porcine pancreas, TypeⅡ (PPL)進行降解,期望藉由生分解材料可被完全分解的特性牽引傳統塑膠材料進行降解。\r 本實驗共分兩階段:第一階段實驗中,將共溶劑揮發製膜進行降解,但由於溶劑法所留下的孔洞,影響了降解速率;因此,在第二階段實驗中,改以熱壓的方式製膜解決孔洞問題,並於降解後以儀器分析降解情形。結果發現:混合薄膜經降解後熔點有下降的趨勢,此可佐證確實可以生分解材料PLA牽引傳統塑膠料PET進行降解,且降解速率和結晶情形和分子鏈段纏繞程度有關,在PET與PLA濃度同為3%時降解情形最佳。

Biochar: the Solution to the Next Green Revolution

1. Purpose of research \r To investigate the feasibility of using municipal cellulosic wastes as feedstock for production of biochar in pyrolysis, the effects of metal catalysts in pyrolysis, and the applicability of the produced biochar as a fertilizer\r 2. Procedures \r A. Investigation into the characteristics of (metal catalyzed) pyrolysis of various cellulosic wastes \r 1. The cellulosic waste (and catalyst) was weighed and put into a boiling tube. The tube was stopped with a plastic bung with holes. A plastic tube and a thermocouple were inserted through the holes. The other end of the plastic tube was submerged. \r 2. A Bunsen flame was used to pyrolyse cellulosic waste. Temperature and time of reaction were recorded. Gas produced was collected underwater. Biochar and bio-oil were obtained and weighed. \r B. Evaluation of adsorptive capabilities of different materials \r 1. Blue light absorbances of KH2PO4 solutions (mixed with vanadate-molybdate reagent to form yellow solutions) at different concentrations were found and an absorbance-concentration curve was established. \r 2. 5g of each material being evaluated was sandwiched between two pieces of filter paper before being put into a suction funnel. KH2PO4 solution was poured into the funnels. The setups were left overnight and filtrates were collected. \r 3. Collected filtrates were mixed with vanadate-molybdate reagent. Concentration of phosphates in each filtrate was found by the curve.\r 3. Data \r I. Highest percentage conversion from waste to biochar: 94.1% (paper towel, iron wool) \r II. Highest sequestration rate of carbon: 98.6% (paper towel, zinc) \r III. Lowest pyrolysis temperature: 162°C (paper towel, copper) \r IV. Best catalyst in terms of speed of biochar production: copper (+47.7%) \r V. Highest speeds of biochar production (w/ and w/o catalyst): 46.4g/hr (paper towel, copper) and 27.7g/hr (sawdust) \r VI. Adsorptions of KH2PO4: 14.4% (biochar from sawdust)/ 9.02% (sawdust)\r 4. Conclusions \r The pyrolysis of cellulosic waste to biochar was achievable at school laboratory conditions, with satisfactory results in carbon sequestration, production speed and percentage conversion. \r Under catalysis by various metals, the production of either biochar or pyrolytic gas and oil can be optimized, providing a low-cost way to derive fuel and sequestration-ready carbon, both crucial as answers to looming crises. The use of copper greatly speeds up pyrolysis and lowers the pyrolysis temperature, further increasing the economic potential of the process. \r Biochar is also an effective means to soil management, as shown in field and laboratory experiments. Its adsorption capability far exceeds that of untreated cellulosic waste, retaining nutrients to be taken by plants instead of leaching away. It was also shown to improve fruit yield and induce ripeness in tomato, making it obvious that biochar is also a viable fertilizer. \r All in all, metal-catalyzed biochar production from municipal cellulosic waste and the subsequent use of biochar as fertilizer have the benefits of: low feedstock cost, low energy cost, fast production, carbon sequestration, soil management and waste recycling. It is a remedy to some of the most persistent and serious global problems: food and energy crisis, water pollution, excessive greenhouse effect alongside waste treatment.

棋盤分割

本研究所探討的主題是一道分割棋盤的題目:\r 給定一個黑白相間的mxn棋盤(設m為縱向邊,n為橫向邊),將其分割成若干個面積大小都不等的矩形區域,且每個矩形的黑格和白格個數相等。設f(m,n)為符合上述條件的最多分割矩形的個數,則f(m,n)是多少?\r 在研究過程中,我們首先藉由對各棋盤進行分類,利用不等式的運算找出其中的關係,求得當m=n以及mn=k(k+1) 時(其中K為正整數)的f(m,n)值,並構造出其分割方法。而k(k+1)

Wind Power

My school requires year 13 students to complete a year long project of a topic of their choice, culminating in the presentation of a thesis, a display and speech to a public audience. Many different topics appealed, but in the end I decided to build a micro wind-turbine. I have always been fascinated with mechanics, mathematics, engineering, aerodynamics and electricity. A wind turbine is a mixture of these technologies, with the overall goal of electricity production. In a world that is starting to see the true costs of fossil fuels, renewable energy seems to be increasingly popular and the demand for electricity is always growing.\r I was aware that building a wind-turbine from the foundations up wouldn’t be easy. Many of the experts I contacted in the early days cautioned me against trying such a complex thing in one year, at the same time as completing a full Year 13 course. There were, however, people prepared to support me. Michael Lawley, who builds micro wind turbines in New Plymouth was very helpful, just full of priceless knowledge and gave me a few basic parts to start with. The knowledge gained from Doug Clark, who also builds his own 11 kW wind turbines, was such an inspiration. Later I had practical help from Wilson Springford and Darron Matthews.\r I investigated and documented the history of and current state of wind technology, as well as my own experience and learning in the design, construction and testing process. I thought it would be interesting to find out how the electrical and mechanical side works.\r The generator, a washing machine motor, needed to be completely rewired, and converted to DC (direct current) from AC (alternating current). I built my own 3-phase AC to DC converter.\r Other parts like the disc brakes and bearings had to be found. The rest was hand-made and every part, to a certain extent, had to be modified. Probably more than twenty braking system design attempts led to the final decision to incorporate the wind-activated hydraulic disc brake where the wind paddle starts to ease the brake on over a certain wind speed.\r I studied the dynamics of wind turbine blades, their shape, the material they were made from and how this affected their performance. The decision to make my own blades helped me gain a great sense of achievement and knowledge of blade design. I found some New Zealand made 100% recycled plastic pipe, an added bonus because I wanted to have minimal environmental impact. I designed the turbine with three blades to give better starting torque along with a lower top speed, perfect for how I wired the generator.\r I designed the swivel, the part of the wind turbine that enables the power cables to get from the turbine down the tower without twisting up and has the job of carrying the whole turbine, which is mostly made from recycled aluminium. The steel and bearings used to create the swivel were all second-hand parts and materials. The power from the turbine passes through the swivel into the cables and down the tower. The main mast of the tower is a little over 4.7 metres and pivots on two shorter supporting poles which go down around 2.6 metres to the bottom of the reinforced concrete foundation.\r I managed to, design and construct an operational prototype micro wind-turbine, incorporating recycled and recyclable materials as much as possible, with the end result surpassing all expectations.

Asymmetric Total Synthesis of GlaxoSmithKline’s Potent Phosphodiesterase PDE IVb Inhibitor

Phosphodiestarase of subtype PDE IVb inhibitors are considered as perspective drugs for the treatment of the central nervous system disorders (depression, Alzheimer’s disease, Parkinson’s disease). Pyrrolizidinone Glaxo-1, proposed by GlaxoSmithKline, is a highly potent PDE IVb inhibitor (IC50 = 63 nM), then conventional phosphodiesterase inhibitors Ro-20-1724, Rolipram and Cilomilast. However the activity of the Glaxo-1 was studied on a racemic sample, since the asymmetric approach to its synthesis has not been developed. Therefore the purpose of this research was the development of an efficient synthetic scheme enabling enantioselective excess to both (-)- and (+)-Glaxo-1, which can be than subjected to biological studies. \r The key stage in proposed asymmetric synthesis (-)- and (+)-Glaxo-1 is stereoselective [4+2]-cycloaddition of the nitroolefin to an optically activity vinyl ethers, derived from (-)- or (+)-trans-2-phenylcyclohexanols. The resulting chiral cyclic nitronates are transformed into a functionalized cyclic oxime ethers using tandem sylilation-nucleophilic substitution procedure. Reduction and decarboxylation of these products lead to optically pure Glaxo-1 and the regeneration of chiral 2-phenylcyclohexanols (91%). \r Thus both enantiomers (+) and (-)-Glaxo-1 were obtained selectively in average yield 12% from isovaniline and nitroethane. The study of biological profiles of each enantiomer of Glaxo-1 will be conducted in near future.

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.

利用農業廢棄物進行連續產氫之研究

本研究嘗試以沒有經濟價值之農業廢棄物,經由化學反應轉換為氫能源,並藉由化工程序來達到連續製程。 我們用爛掉的香蕉為基質,從校園及生活周遭的環境尋找產氫微生物,發現可生產氫氣之微生物隨處可得。在培養溫度35℃下,選擇不同濃度之基質,發現基質濃度與產氫量成正比,且產氫微生物適合在弱酸(約pH=5.5)環境中生長。 以此條件進行連續式反應,當反應槽體積為700ml時,經過26小時後,槽內基質消耗殆盡,此時開始連續進料,當進料流速為138毫升/小時,則水力停留時間為11.67小時,產氫量為5.43升/天,最後連接氫燃料電池,可得到連續產生的電能。另外本實驗也以爛木瓜進行批次反應,同樣也能獲得氫氣。 經由實驗結果可得知,利用農業廢棄物為基質,可運用化工程序發展為連續產氫製程,且應用於實務上,能提升全球環保的概念,我們期待能開創一個能取代「碳經濟」的「氫經濟」。

Effect of Certain Plant Extracts on Fruit Set and The Prevention of Jatropha curcas Linn’s Insect Pests

The objectives of this study were to investigate (1) the floral biology of Jatropha curcas Linn. as well as its possible pollinators, (2) the correlation between the number of pollen on stigma and the frequency of floral visitors, (3) the attractiveness of essential oil extracts from three species of Lamiaceae, i.e. Hyptis suaveolens, Plectranthus ambonicus and Orthosiphon aristatus, to Apis florae, (4) the repellent effect of crude extracts from three species of Graminae, i.e. Imperata cylindrica, Eleusine indica and Dactyloctenium aegyptium, on Polyphagotarsonemus latus, and (5) the effect of appropriate combination between lamiacean essential oil and graminaceous crude extract on the percentage of fruit setting and insect pest protection. \r Jatropha curcas is monoecious plants with tiny male and female flowers borne on the same paniculate cyme. One plant produces 15-30 inflorescence. Each inflorescence composes of 70-120 florets, and only 4-8 florets are successfully setting fruits. Each flower takes approximately 17 days in developing from floral bud till floral opening. The appropriate time for pollination is from 09.00 am to 10.00 am. While bees, wasps, hornets, flies and dragonflies are its potential pollinators, mites, aphids and worms are its harmful insect pests. \r Three volumetric, 1, 3, 6 and 9 ml, of each essential oil extracts were separately sprayed on each observed inflorescence. According to the experiment, 6 and 9 ml of each of the essential oil extracts give similar effective outcome, However, The H. suaveolens extract at 6 ml is the most effective attractant for A. florae. because it uses less of the oil extracts.\r Four concentrations, 0.1 %, 0.5 %, 1.0 %, 1.5 % and 2.0 % of each of the crude extracts from three graminaceous plants were sprayed on each tested plants separately. Concentations above 1.0% consistently provided an effective biocidal activity against Imperata cylindrica , however 1.0% is accecptable. because it uses a reduced level of the crude extracts\r The combination of H. suaveolens’s essential oil and I. cylindrica crude extract both significantly enhanced fruit setting of J. curcas and protected the plant from Polyphagotarsonemus latus without adverse effect on its pollinators.