全國中小學科展

2022年

高鹽飲食對果蠅學習與記憶能力的影響及其細胞與分子機制

先前論文指出高鹽飲食會造成果蠅睡眠間斷(Jiayu Xie et al., 2019)、減短果蠅壽命(Deng-Tai Wen et al., 2020)。而另一篇論文則以小鼠作為實驗對象,發現高鹽飲食會影響小鼠記憶和學習能力(Giuseppe Faraco et al., 2018)。根據上述,高鹽飲食在不同生物中可能影響神經系統的功能,但果蠅學習與記憶能力的影響還未被探討。因此,筆者以果蠅作為模式生物,研究高鹽飲食對其學習與記憶功能是否障礙及實驗其可能的細胞與分子機制。在將野生型果蠅進行測試後,選擇了Canton-S做後續實驗,並發現餵食Canton-S 四天的高鹽食物後學習及短期記憶表現下降,而進行實驗確認是由高鹽飲食導致此障礙,再研究了一系列相關研究。 本次實驗中,首次以餵食高鹽食物對果蠅學習與記憶障礙方面進行研究,並了解到高鹽飲食也會讓果蠅產生學習與短期記憶能力障礙。目前為了找出真正的細胞與分子機制提出可使用的方法,在實驗其他可能的機制。

The influence of lanscape on nest preferences and behavior of twig nesting Hymenoptera

The occurrence and behavior of insects is significantly affected by the environment they live in. In this thesis, I dealt with the influence of structure of landscape on nesting preferences of Hymenoptera. For this comparison I had chosen to work with twig-nesting Hymenoptera, for which I have placed artificial nest opportunities into four biotopes – heath, edge of a heath, country lanes between fields and field. The studied location is located south of Znojmo near Podyjí national park. Particularly, I have focused on small carpenter bees of genus Ceratina. My results show that there is a big difference in the species distribution between the habitates of field and heath. The habitats of edge of a heath and country lanes make up a gradient between these two biotopes. The ecosystem of fields was preferred by a sphecid wasp Pemphredon lethifer and Ceratina cyanea. On the other hand, the ecosystem of heath was preferred by Ceratina chalybea, Ceratina nigrolabiata and megachille bee Hoplitis tridentata. I had also found out that in species that are more abundant on heaths, there is higher mortality of offsprings. Heaths were a place of the highest competition between species, as a result of which species with a lower body weight (Ceratina nigrolabiata) have been pushed into narrower twigs by larger species (Ceratina chalybea). I recorded a high number of nests in biparental bee Ceratina nigrolabiata, which were guarded only by mother in fields and country lane habitats. This may indicate that Ceratina nigrolabiata is only facultatively biparental, not strictly biparental as was considered until now.

An Analysis and Optimization of Double Parallelogram Lifting Mechanism

Double Parallelogram Lifting Mechanism (DPLM) is a compact and stable lifting mechanism with a large extension range widely adopted in robot designs. Rubber bands and springs are often installed on the DPLM to lighten the motors' load and maintain its height, yet the installation positions are often obtained through trial and error. This project aims at finding the optimal rubber band installation positions for DPLM using modeling and optimization techniques. A mathematical model which describes the forces and moments acting on all the linkages of DPLM was derived based on the conditions for the static equilibrium and verified with a 3D simulation software. A genetic algorithm (GA) was implemented to optimize rubber band installation positions, which managed to find solutions with the overall root-mean-square- error (RMSE) of the net moment less than 2 for 2 to 6 rubber bands. A further statistical analysis of 50000 random rubber band samples showed that installing rubber bands in triangles is the best solution with the overall lowest RMSE. A test was conducted with a prototype of the DPLM and the results were consistent with our model and optimization. This project derived and verified a mathematical model for the DPLM, and found the optimal way and positions to install rubber bands. The results of this project provides a theoretical basis for controlling DPLM with rubber bands, allowing it to be further adopted in industrial robots that require repetitive lifting and lowering such as inspection robots and aerial work platforms.

Modification of silica surface with supercritical water as a tool indicating new possibilities of existing separation methods

Silica capillaries have been an integral part of the instrumentation used in many areas of analytical chemistry for decades, especially in analytical separations. In most cases, they are used without treatment, occasionally forceless chemical surface treatments are made to suppress or enhance the activity of silanol groups. The aim of this work was to disrupt the inner surface of the capillary, perfectly smooth from manufactory, so that relatively coarse and various structures would be created, and to study their influence on the separation efficiency. The uniqueness of the used solution is based on the use of special properties of water exposed to high temperatures and pressures (supercritical water), which is able to disrupt this chemically inert material because of its aggressivity. In total, over 2000 experiments were carried out in order to define conditions suitable for the formation of various types of surface structures. Due to the high amount of resulting data, our own database application was created, allowing not only to save the picture of the structure and experimental conditions information, but also to clearly sort them out and create image reports according to the specified parameters. Samples representing individual types of structures were then selected from this database and a number of silica capillaries with a configuration suitable for electromigration analyzes were prepared. The creation of a structured surface in the input part of the separation capillary enabled the separation of some classes of substances and biosamples, which cannot be analyzed on standard capillaries with a smooth surface. An example is the complete separation of two strains of Staphyllococcus aureus bacteria (MRSA and MSSA), or the use of the absorbing capabilities of a structured surface to study the interactions of these bacteria with bacteriophages. This ability was also used in the determination of Aspergillus fungus in a sample taken directly from the patient's lungs, where there was achieved a significant increase in the sensitivity of the analysis. Structured capillaries can also be used in the analysis of food samples, i.e., for the separation of β-lactoglobulins A and B in cow's milk, which belong to its main allergens.

A Person Re-identification based Misidentification-proof Person Following Service Robot

Two years ago, I attended a robot contest, in which one of the missions required the robot to follow the pedestrian to complete the task. At that time, I used their demo program to complete the task. Not long after, I found two main issues: 1. The program follows the closest point read by the depth camera, which if I walk close to a wall next to, the robot may likely ‘follow’ the wall. 2. Not to mention if another pedestrian crosses between the robot and the target. Regarding these two issues, I decided to improve it. We’ve designed a procedure of using YOLO Object Detection and Person re-identification to re-identify the target for continuous following.

A Person Re-identification based Misidentification-proof Person Following Service Robot

Two years ago, I attended a robot contest, in which one of the missions required the robot to follow the pedestrian to complete the task. At that time, I used their demo program to complete the task. Not long after, I found two main issues: 1. The program follows the closest point read by the depth camera, which if I walk close to a wall next to, the robot may likely ‘follow’ the wall. 2. Not to mention if another pedestrian crosses between the robot and the target. Regarding these two issues, I decided to improve it. We’ve designed a procedure of using YOLO Object Detection and Person re-identification to re-identify the target for continuous following.

Territorial behaviour of the Eurasian Wren (Troglodytes troglodytes) during autumn migration and wintering in the urban environment of Hradec Králové, Czech Republic

In the present paper I studied the winter territories of the Eurasian Wren (Troglodytes troglodytes) in the urban environment of the city of Hradec Králové. The males of this species were detected through the aggressive reactions to the playback of its conspecific call. The Eurasian Wren territories were detected at seven out of the ten observation points in the city. The frequency of the territories decreased during the observation period from October to January and it was also affected by the structure of the biotope. It seemed that the wrens preferred trees and avoided lawns and isolated growths. That illustrates how important it is to maintain wildlife corridors in the cities. Individuals of seven other bird species were seen reacting to the playback of Eurasian Wren songs or warning calls. Eurasian Wren may be applied as an indicator species of the ecological value of the urban environment. Through this species, we can access such quality also for the human inhabitants.

如何坐才能學得好

學校教室是一個學習環境,課桌椅是重要的物理元素。目前學校所採購的椅子皆以多數人來設計,因此無法量身訂作。然而學生每天在校有一半以上的時間都是坐在椅子時間進行學習,在實務環境考量下,只能就調整學生坐姿的面積與倚靠方式進行調整。為此,本研究將探究不同的坐姿(深度與高度)對於學習成效的影響。 本研究採用二因子使用者內實驗法設計(深度與高度)針對成年人進行短時間高專注的學習任務:短期記憶、數字計算與邏輯判斷以及使用眼動儀與腦波儀紀錄長時間閱讀分心程度。 實驗結果顯示:短時間高專注任務中,坐姿深度與坐姿依靠高度具有交互作用影響。整體來說,坐姿1/3深度與椅靠下背部高度都具有不錯的學習效果;其次,在長時間閱讀分析中,坐姿1/3深度或椅背無倚靠,其分心次數相對來得高。 根據研究結果建議學校或教育機構,短時間高專注學習任務,可以短暫要求學生坐姿深度較淺且無倚靠椅背,但長時間下來建議以坐姿2/3以上深度,高度為下背部以上較為合適。。其次,建議設計學校採購椅子時可以簡易改良移動式椅背或者請學生攜帶腰部靠枕調整座椅深度,對於教室課堂學習來說將有較佳的學習效果。

PVA unveiled the actual role of starch in the Briggs-Rauscher reaction

The Briggs Rauscher reaction (BR reaction) is one of the famous oscillating reactions; the aqueous mixture of KIO3, H2SO4, H2O2, C3H4O4, MnSO4, and starch exhibit color change between yellow and blue-purple repeatedly. The blue-purple color formation is due to the iodine test reaction caused by inclusions of polyiodides such as I3- and I5- in the helical structure of starch. Therefore, starch has been regarded as only an indicator in the BR reaction. But our seniors have found that the oscillation did not last without starch. They hypothesized that starch’s linear helical framework is necessary to elongate the lifetime of the oscillating reaction. If this hypothesis is correct, similar BR-type oscillations must be observed when other polymers with helical structures are used instead of starch. We found the literature which reports that polyvinyl alcohol (PVA) forms a helical structure and indicates the iodine test reaction. In our research, we studied the BR reactions using PVA, with different saponification degrees and viscosities. First, we studied the correlation between the structural features of PVA and the iodine color reaction by spectroscopic approach, exhibiting that PVA with low saponification form helical structures and show the iodine color reactions, which gives red color solutions. Second, we found that additions of the helical-structured PVA to the reaction solution instead of starch induces the BR-type oscillating reactions, while PVA without helical structure induces only a few numbers of oscillations. This is the world-first example of the oscillating reaction using PVA. The oscillation that lasted for 6 minutes with 23 oscillations was almost the same as that of the general BR reaction using starch. We concluded that the polymers with helical structures are intrinsic to elongate the lifetime of the BR reaction. Furthermore, we found that the addition of K3[Fe(CN)6], which has a high redox activity, in the reaction solution with PVA drastically elongated the lifetime (50 min) and increased the numbers of the oscillations (nearly 100 times). This result suggests that the oxidation-reduction reactions by the ferricyanide ion promotes the redox process of iodine and iodide ions.

Development of an Audio Modulated Tesla Coil

Originally, the Tesla transformer was developed to transmit energy and messages wirelessly. But it did not prove itself for either of these applications, so today it is only used for research purposes. Over time, the Tesla transformer has evolved and improved. Today it is possible with Tesla transformers to generate powerful and highly precise controlled discharges. During operation, impressive high-voltage discharges occur at the transformer. A tesla transformer is basically a high voltage generator that achieves a voltage boost by using two magnetically coupled LC series resonant circuits of the same resonant frequency. The Dual Resonant Solid State Tesla Coil (DRSSTC) built in this work has a high power IGBT half bridge module to excite the primary resonant circuit at the resonant frequency. The IGBTs are driven in such a way that audible pressure waves, and therefore music, are generated by the electrical discharges at the high voltage electrode. Within the scope of this work were the following two questions: - How is a DRSSTC designed and built? The DRSSTC system realized in this work is about 80 cm high and reaches about one-meter-long discharges. The design, development, and construction of the transformer are documented in detail and extensively in this thesis. - How does one measure an electrical voltage of 200,000 V, which changes sign more than 100,000 times per second? Two approaches have been taken to measure the voltages. Derived from the energy balance of an ideal capacitor and an ideal coil, a secondary voltage of about 200 kV was calculated via secondary current measurement. The second approach uses a voltage measurement via an in-house developed measuring electrode and a calculated divider ratio between the measured voltage and the secondary voltage. A relatively unrealistic secondary voltage of about 750 kV was measured since the divider ratio depends on approximate values. Nevertheless, the measuring electrode can be used for investigations of the voltage curve, or the divider ratio can be calibrated via the secondary current measurement. The development of such a transformer laid the foundation for much further research and scientific analysis.