全國中小學科展

2022年

Properties of possible counterexamples to the Seymour's Second Neighborhood Conjecture

The project is devoted to the study of the Seymour’s Second Neighborhood conjecture by determining the properties of possible counterexamples to it. This problem has remained unsolved for more than 30 years, although there is some progress in its solution. The vector of the research is aimed at the analysis of possible counterexamples to the conjecture with the subsequent finding of some of their characteristic values. In addition, attention is focused on the generalized Seymour’s conjecture for vertex-weighted graphs. Combinatorial research methods and graph theory methods were used in the project. The author determines the values ​​of densities and diameters of possible counterexamples, considers separately directed graphs of diameter 3. The conditions under which specific graphs cannot be counterexamples to the Seymour’s conjecture with the minimum number or vertices are defined. The relationship between the Seymour’s conjecture and vertex-weighted Seymour’s conjecture is explained. It is proved that if there exists at least one counterexample, then there exist counterexamples with an arbitrary diameter not less than 3. Under the same condition, the existence of counterexamples with a density both close to 0 and close to 1 is also proved. The equivalence of the above two conjectures is substantiated in detail. It can be concluded that if the Seymour’s Second Neighborhood Conjecture is true for a directed graph of diameter 3, then it is true for any digraph, so that problem will be solved. Moreover, if the conjecture is true, then vertex-weighted version of this conjecture is true too. That is why a digraph of diameter 3 needs further research.

蚊幼蟲與搖蚊幼蟲在水中分布與其血紅蛋白基因表現之關係

蚊蟲呼吸透過氣管系統,本研究假設底棲孑孓與搖蚊幼蟲具備血紅蛋白系統以擷取氧氣。戶外採集8種孑孓和1種搖蚊幼蟲,錄影觀察白腹叢蚊、竹生翠蚊和鹽埕搖蚊幼蟲長時間停留底層;家蚊、斑蚊則反覆上下至水面呼吸。顯微鏡下發現白腹叢蚊幼蟲體壁內側充滿紅點,色澤隨著富氧或缺氧而變化;然二種斑蚊則不明顯。PCR增殖6種蚊蟲和1種搖蚊血紅蛋白基因片段並建構親緣關係樹。定量RT-PCR顯示,白腹叢蚊與鹽埕搖蚊在缺氧條件下,血紅蛋白相對表現量分別增加5倍和150倍,上層埃及斑蚊和白線斑蚊則增加3.9倍和1.5倍。西方墨點法證實孑孓缺氧條件下,17-kDa血紅蛋白皆有大量表現。本研究首次確定6種蚊蟲具血紅蛋白基因,證明孑孓血紅蛋白基因在缺氧下的表現量增加,包括mRNA與蛋白質。此等反應氣候變遷,暖化導致水溫升高與低溶氧條件下,蚊蟲可能有因應環境改變的呼吸機制。未來將進一步標幟血紅蛋白在蚊幼蟲體內組織之表現與其他環境變因之影響。

強菌來襲!口腔大騷動!——食品中乳酸菌對牙齒保健的影響

乳酸菌(Lactic acid bacteria)是生活中常接觸到的菌種,除了製作食品,也有研究指出部分乳酸菌菌株可抑止造成齲齒的「變異鏈球菌」生長,目前已有牙膏等產品號稱添加乳酸菌。但乳酸菌發酵產生的乳酸,會分解牙齒的琺瑯質,所以我們從發酵乳食品中分離出9株乳酸菌,並進行氫氧基磷灰石的分解實驗與對變異鏈球菌的抑菌實驗。經過實驗,1號、5號、6號與8號乳酸菌株對氫氧基磷灰石的分解能力較弱,而6號、8號與15號對變異鏈球菌的抑制效果較明顯,實驗結果交互比較後,得出6號和8號菌作為牙齒保健的應用價值較高。未來若能進一步研究,可嘗試以離心將乳酸菌各部位分離,研究其真正有抑菌作用的物質,並加以純化,應用於保健食品中。

Preparation of a Specific Detector for Aspergillus Niger in Swimming Pools

Swimming pools are one of the transmission routes of superficial and cutaneous fungal infections. Maintenance of environmental hygiene in different parts of swimming pools is of great importance, especially the hygiene of water (1). The conventional fungal detection methods include direct smear preparation, culture, and pathological examinations. However, these methods are not fast enough or do not have sufficient sensitivity (2). Therefore, the present research introduces a novel method for detecting Aspergillus niger in pool water through creating optimal conditions for this fungus, which leads to the citric acid production by the fungus and pH changes of the related culture medium. Four experiments in 10 steps were performed to find the optimal conditions for fungal growth. According to our results, adding each of the variables sucrose, soy, and ferrous sulfate can lead to favorable results. Moreover, the shaker speed increase and fungal aeration are important. Also, we showed that soybean led to the best results compared to other variables. Considering the obtained results, including the shortened detection duration and cost-effectiveness, this method can be presented to the swimming pool owners and pathobiology laboratories as the method of choice for Aspergillus niger detection.

Solving Mathematical and Chemical Equations using Python

Max Gold's project, titled “Solving Mathematical and Chemical Equations using Python”, is a website comprising of 4 main programmes: one to find the smallest possible combination of two chemical compounds or elements; a self-made parsing function to convert a chemical equation into a matrix, then using Gaussian-Jordan elimination to find coefficients for an equation; a programme to parse a mathematical expression and use that parsed expression in algebraic division of an algebraic dividend of nth degree polynomial by a divisor of 1st degree polynomial; finally, a programme to solve binomial equations for the power s∈Q. This website was originally made so that Max Gold could improve his programming skills for GCSE computer science but expanded to incorporate his passion for chemistry and maths and thus allow others to use these programmes to help them with their problems as well. A problem with many conventional calculator websites is their lack of specificity – they tend to be able to compute some functions but not all. These programmes are tailored to GCSE and A level maths and chemistry, meaning this website provides an outlet to compute specific topics of problems.

Cross-lingual Information Retrieval

In this project, we evaluate the effectiveness of Random Shuffling in the Cross Lingual Information Retrieval (CLIR) process. We extended the monolingual Word2Vec model to a multilingual one via the random shuffling process. We then evaluate the cross-lingual word embeddings (CLE) in terms of retrieving parallel sentences, whereby the query sentence is in a source language and the parallel sentence is in some targeted language. Our experiments on three language pairs showed that models trained on a randomly shuffled dataset outperforms randomly initialized word embeddings substantially despite its simplicity. We also explored Smart Shuffling, a more sophisticated CLIR technique which makes use of word alignment and bilingual dictionaries to guide the shuffling process, making preliminary comparisons between the two. Due to the complexity of the implementation and unavailability of open source codes, we defer experimental comparisons to future work.

腦波辨識特徵提取於即時身分認證的研究

本研究的腦波辨識基於特徵提取,可應用於身分認證,具有不能被仿冒的優點。我們用低成本高便利性的腦波儀,自行撰寫程式讀取原始腦波,建立一致性的實驗程序。首先用腦波專心度的高低來控制智能車,再用腦波來測謊,有隱藏說謊行為時會觸發高電位腦波,在兩項前期研究後發現可用腦波特徵進行身分認證。三位受測者於不同日期提取10份腦波,每份腦波紀錄5120筆數據。接著我們反覆嘗試組合數十種統計函數進行特徵提取,找到兩項最佳特徵,達成將大量凌亂腦波資料降低維度又具有辨識力。我們腦波辨識分類方法使用近鄰演算法,測試程序用盲測交叉驗證法,辨識正確率百分百。最後我們用Arduino板來展示腦波辨識應用於腦波身分認證,資料庫中只要儲存每位受測者的腦波特徵值,就能在數秒內正確辨識說出受測者身分,顯示每個人腦波是不同的,而且能用特徵將其分辨出來。

利用 CRISPR/Cas 技術重建複雜的DNA 修復機制

本研究利用合成生物學技術開發的創新基因組篩檢平台PRISM(v2.0),採用合成轉錄因子(crispr-TF)辨認DNA但不進行剪切,透過修改CRISPR/Cas的PAM-interacting (PI) domain序列打破其辨認限制,由原本NGG序列變成可以結合NAG的序列,提升crispr-TF在高通量基因組的篩選能力,期待未來可以做出辨認NNN序列,以此技術初步成功建構Chk2/Rad53所參與的基因網絡,讓失去Chk2/Rad53功能的酵母菌能在DNA損傷的情況生存。Chk2/Rad53蛋白磷酸酶在DNA修復的訊息傳遞中調控龐大的基因網絡,其中潛在大量不同調控路徑聯結的組合性,過去的研究都無法有效地分析且重建完整的DNA修復機制。未來將進一步探討Chk2/Rad53調控的下游基因組,並以此新技術和研究應用於複雜腫瘤與老化疾病的預防及治療。

探討有機分子官能基對胰島類澱粉蛋白(IAPP)之影響

過去許多文獻報導胰島類澱粉蛋白(islet amyloid polypeptide;IAPP)在體內的不正常聚集的現象,會造成分泌此賀爾蒙的β-細胞凋亡,間接導致胰島素分泌的下降,因此被認為與第二型糖尿病有高度的相關性。本研究利用不同官能基之香豆素(Coumarin)衍生物,測試其對胰島類澱粉蛋白之作用;實驗中成功合成高純度IAPP胜肽,再與香豆素衍生物(其光學特性已被檢測)進行混合,爾後進行硫磺素-T動力學試驗及穿透式電子顯微鏡觀察,我們發現某幾個香豆素衍生物確實會影響IAPP的聚集,再藉由圓偏光二色性光譜進一步瞭解有機分子對於IAPP聚集結構之影響,也利用分子模擬的方法來探討其如何與IAPP作用。 本實驗首創以香豆素作為基本骨架,探討官能基結構與IAPP間之交互作用,期待此研究成果可提供第二型糖尿病病症治療之契機與方法。

Generating Conditioned Air in an Open Space in Accordance with Sustainable Architecture Criteria (Based on Wind-Catchers)

Nowadays, cooling open spaces in hot seasons without using fossil fuels has gained a lot of attention. In this regard, natural air conditioning is a great method for conserving energy that can be used for reducing energy consumption and environmental pollution. Structures like windcatchers are used for natural air conditioning as a building component in warm climates since they are placed in the path of the wind and direct the wind to play a significant role in reducing the temperature. The main objective of the current study is to explore air conditioning in open spaces based on sustainable architecture. The current study reviews the relevant literature from credible journals, and it includes studies with relevant subjects published from 1851 to 2021. The findings show that implementing this design project can result in significant advances in terms of reducing humidity, removing dust and insects from the air, conserving energy, reducing the global temperature, using renewable energies, and producing conditioned air for the area