New Evidences of Behavioral Mechanism for Discrimination and Orientation of the Orb-web Spider, Nepi
由於結網性蜘蛛視覺不靈敏,如何在網上藉振動進行獵捕,這是長久以來頗令科學家困惑的難題,當周遭環境各種振源觸網時,首先會產生不同振盪,蜘蛛是否藉由這些振盪得知獵物資訊?如何迅速準確的定位?又有那些決策條件影響蜘蛛的捕獵行為?更特別的,為何蜘蛛在捕獵過程中會“扯網”?本研究以台灣最大型結網性蜘蛛-人面蜘蛛為研究對象,並設計出一套非接觸式的測量方法,就上述謎題作深入的探討後,成功的解開人面蜘蛛的捕獵機制。簡單來說,其機制分為兩大系統:(1)當獵物擾動不明顯,人面蜘蛛會立即扯網,藉有無產生阻尼振盪,以判斷有無獵物存在;在阻尼振盪產生時,蜘蛛將感知其中具有最大阻尼振盪之放射絲為獵物所在方向,而振盪週期長短,係蜘蛛用以判斷獵物遠近之有效因素。(2)當振源明顯時,蜘蛛直接判斷各種擾動的振幅大小、頻率高低、波形模式、振源質量輕重,決定是否啟動捕獵或逃離反應,並在反應前先行定位,亦即以步足腳勾偵測並比較各放射絲之振盪大小,以振盪最大之放射絲為獵物方向,其次藉由第二對步足之位移所產生之準光角,判斷獵物之遠近。蜘蛛正確的將獵物定位後,會以適當的速度往前衝,一口咬住獵物,以蛛絲重重包裹後,拖往網中央並進行吸食。 Giant wood spider, Nephila pilipes, is the biggest orb web spider in Taiwan. The mature N. pilipes may even grow to exceed 5 cm body length. While waiting for the prey, its giant body hangs quietly on the hub of the web. Owing to its ineffective vision and sense of smell, the spider depends almost on detecting the vibration signal of the struggling of web cause by the struggling prey. When various kinds of sources from the environment contact the web, they will generate various types of vibrations which cause the spider to judge whether they represent danger, prey, or irrelevant signals. Our results suggest that if the disturbance is obvious, through discriminating the amplitude and frequency of the vibration, the spider will make a decision whether to attack or escape immediately. Yet, before any decision is made, it will need to locate the source of vibration. For example, it will locate prey correctly by comparing the vibration transmitted from the radiating strings. The radiating strings that transmitted the largest vibration are where the prey is entangled. The displacement of the second pair of legs will generate a quasi visual angle which enables it to comprehend the distance of prey. When the vibration signal is obscure, it will jerk the radiating string immediately. After jerking it, if there is damping oscillation on the web, then the spider can judge the location of the prey. When there is damping oscillation, the radiating string that transmitted the greatest damping oscillation is where the prey is entangled. Furthermore, the frequency of damping oscillation helps the spider to judge the distance of the prey. After locating the prey correctly, N. pilipes approaches the prey fast, wraps it with silk then drags the prey to the hub to feed.\r
USING IRON-STEEL INDUSTRIAL WASTE SLAGS AS A FERTILIZER
Steel slag, is received from iron and steel production facilities in Turkey, and is up to 25-30% from steel production. These couldn’t have been reclamation for any field of use and free stored in nature. When the structure of this slag examined, it was contained metallic formation (Fe2O3, Al2O3, MnO2, MgO2 etc.) and oxide compositions (SiO2, CaO2 etc.). The aim of this project is investigate metallic content of steel slag used as fertilizer in plants. For this purpose, slag is used to determine the physical and chemical characterization. Then, it is separated from metallic content by using shaking table and multi gravity separative (MGS) method. After these procedures, there are determinate 6 groups with different densities and different grit size. Element analysis was made of these groups by atomic absorption spectrophotometer (AAS) and ICP-OES system. In addition, mineral analysis was determined by XRD device. Thus, within each group minerals have been identified. Slag-soil mixture was prepared for determination the highest yield of using six different slag groups as fertilizer in the plant. Thus, corn crops were grown in different combinations. Then harvested corn plants and done soil analysis of the plants. As a result of experiments, percentage of the most effective slag-soil composition for corn was determined. The highest yield in the slag pot was determined the rate of %12.5 and coarse-grained. Ideally, the slag content found to be chinerals such as merwinite (3CaO-MgO-2SiO2), akermanite (2CaO-MgO-2SiO2), gehlenite (2CaO-Al2O3-SiO2). Thus, it was detected the steel slags can be used as feed material for plants. Hence by maintaining the ecological balance economic contribution to the country was achieved.
Reactions of Bis(oxy)enamines with Transition Metal Halides
Synthesis of halooximes has attracted much attention given their importance as precursors to proline derivatives1, unnatural amino acids2 and a host of alkaloids3. Halooximes have numerous industrial and biological applications 4, for example oxime ethers increases specific channel opening activities, acting as potential targets in drug treatment for various diseases 5, most adrenergic β-receptor blocking compounds also conform to the structure of oxime ethers 6. They also have vitro antifungal activities against certain plants7. A known method for the synthesis of 3 using Me3SiX as a Lewis acid, via intermediate enamines with acyclic/ cyclic bis(oxy)enamines, gives yields between 21-68%. Low yield stems from lack of reaction specificity2. In this work, we investigate coupling nitrogen-oxides with CoBr2 to synthesise halooximes in high yield. Initial cyclic/ acyclic bis(oxy)enamines were prepared by reacting 1 equiv. nitro compound with 2.4 equiv. in excess of dichloromethane under argon atmosphere at a temperature of 0ºC. 2.2 equiv. of TMS-Br was further added and left to stir till thermal equilibrium with room conditions. The cyclic/ acyclic bis(oxy)enamine was isolated upon aqueous work-up, filtration and evaporation. Synthesis of halooximes was carried out by reacting 8mL to 1mmol equiv. of THF and 2 equiv. of CoBr2 under argon atmosphere and left to stir till CoBr2 dissolves. 2mL to 1mmol equiv. of CH2Cl2 was added to 1 equiv. of bis(oxy)enamines. The reaction mixture was left to stir at room temperature for 2 hours, after which aqueous work-up, filtration and evaporation were carried out. Our results are summarized in Table 1. We also obtained relatively high percentage yields for the direct synthesis of bromooximes from cyclic nitronates via a one-pot procedure: Low yield stems from lack of reaction specificity2. In this work, we investigate coupling nitrogen-oxides with CoBr2 to synthesise halooximes in high yield. Initial cyclic/ acyclic bis(oxy)enamines were prepared by reacting 1 equiv. nitro compound with 2.4 equiv. in excess of dichloromethane under argon atmosphere at a temperature of 0ºC. 2.2 equiv. of TMS-Br was further added and left to stir till thermal equilibrium with room conditions. The cyclic/ acyclic bis(oxy)enamine was isolated upon aqueous work-up, filtration and evaporation. Synthesis of halooximes was carried out by reacting 8mL to 1mmol equiv. of THF and 2 equiv. of CoBr2 under argon atmosphere and left to stir till CoBr2 dissolves. 2mL to 1mmol equiv. of CH2Cl2 was added to 1 equiv. of bis(oxy)enamines. The reaction mixture was left to stir at room temperature for 2 hours, after which aqueous work-up, filtration and evaporation were carried out. Our results are summarized in Table 1. We also obtained relatively high percentage yields for the direct synthesis of bromooximes from cyclic nitronates via a one-pot procedure:
Ancient Medicine- Modern Approach
The apricot kernel is believed to have a great medicinal value in many cultures. However, literature and research indicates that this belief still remains extremely controversial and conclusions regarding the medicinal value are ambiguous due to the presence of cyanide in the kernel. The focus of this research was to evaluate two objectives through the use of several integrated technologies and modified methods: (a) To successfully remove the cyanide from the apricot kernel using an adapted method; (b) To determine the effects of the cyanide free apricot kernel extracts on Helicobacter pylori and Streptococcus pyogenes bacteria. Procedures The apricot kernels were removed from the pits and then ground using a food processor. The kernels were then tested for cyanide using a cyanide test kit and Cyantesmo test tape. These tests indicated that cyanide was present. A novel approach was devised to remove the cyanide and when retested, the kernels tested negative for cyanide. This result was confirmed with Infrared Spectroscopy. The cyanide free kernels were then extracted using a Soxhlet Extractor with methanol for 24 hours. In addition to the methanol extraction, three other techniques were used to obtain kernel extracts: (a) Celite filtration, (b) Infusion Method A, (c) Infusion Method B. The Kirby Bauer method was modified for the microbiology aspect of this project. The Helicobacter pylori and Streptococcus pyogenes bacteria were plated using a 0.5 McFarland Standard. Paper filter discs containing 20µL of each extract were placed onto the inoculated plates in replicates of nine. After 48 hours of incubation, the zones of inhibition were read for each plate. Data The results were extremely encouraging and therefore to ensure the accuracy and preciseness of the data collected, four statistical analyses were completed. These include Confidence Intervals (CI), Standard Deviation (STDEV), T-Tests, and Chi Tests. The methanol extract was significantly different from the control in all trials. The Chi test also yielded a Chi Square value of 223, which was significantly greater than the critical value of 15.507, indicating that the results observed were not due to coincidence. Conclusion Literature evidence has indicated that the apricot kernel has been and is still used for medicinal purposes. Studies have shown that the presence of cyanide and the risks associated with this compound outweigh any benefits gained from the kernel. It has also been suggested that previous bacterial testing resulting in positive inhibition may have been due to the presence of cyanide. However, in this study, I was able to remove the cyanide through an innovative method to prove that the biological activity observed was highly unlikely to be due to cyanide. This indicates that there are other compound(s) in the apricot kernel that have specific antibacterial properties. The potential to improve the quality of life through the application of the apricot kernel appears to be supported, and further studies justified at this time.