Description: In this study we applied ultra-short laser pulses on a biological sample (Arabidopsis), in order to cut it precisely in a square pattern and subsequently use it for studying stress generation mechanisms. For this purpose, we utilized femtosecond laser pulses at 100 fs pulse width and 80 MHz repetition rate. We took two processing parameters into consideration such as laser power, laser exposure time which is related to the stage speed. Therefore, we were able to find the laser optimum conditions for ablation of biological tissues. The mutant and wildtype (control) obtained from laser cutting with a size of 500 µm × 500 µm were directly transferred (in-situ with laser cutting) into a microfabricated chamber containing ~500 nanoliters deionized water for measuring ion conductivity. The ion conductivity is a signature of cell-death mechanisms caused by various stresses. A light with intensity of 100 µmol was exposed to the samples for 2 hours and 20 minutes as a source of stress. A quantitative electrical analysis with high accuracy was assured by utilizing a microchamber, which enables a measurement in nanoliter volume. We measured the impedance which is reciprocal of conductivity using a lock-in amplifier and a precise current source at frequency ...

Description: This descriptive, non-experimental study examines the strength of the relationship between California school library media programs and student achievement, using data from California criterion-referenced state-wide tests, publically available school and community demographic data, and a state survey of school library programs. Results indicate a substantial discrepancy in library staffing levels from the elementary grades through the high schools. Nevertheless, statistically significant correlations were found between certificated staffing levels and student achievement at each grade. Significant correlations persisted at the elementary and middle school when controlling for five of six school and community variables, and at the high school when controlling for all six of those variables. Bivariate correlations between total staffing and student achievement were significant at both the middle school and high school level when controlling for all school and community variables. Generally, the strength of the correlations between both certificated and total staffing tended to increase with grade level; at the high school level, correlations were among the strongest reported in any statewide study to date. There was a significant positive relationship between a majority of the 21 library services regularly provided and student achievement at all levels. Total library services were significantly related to student achievement at ...

Description: The major challenges facing resource constraint wireless devices are error resilience, security and speed. Three joint schemes are presented in this research which could be broadly divided into error correction based and cipher based. The error correction based ciphers take advantage of the properties of LDPC codes and Nordstrom Robinson code. A cipher-based cryptosystem is also presented in this research. The complexity of this scheme is reduced compared to conventional schemes. The securities of the ciphers are analyzed against known-plaintext and chosen-plaintext attacks and are found to be secure. Randomization test was also conducted on these schemes and the results are presented. For the proof of concept, the schemes were implemented in software and hardware and these shows a reduction in hardware usage compared to conventional schemes. As a result, joint schemes for error correction and security provide security to the physical layer of wireless communication systems, a layer in the protocol stack where currently little or no security is implemented. In this physical layer security approach, the properties of powerful error correcting codes are exploited to deliver reliability to the intended parties, high security against eavesdroppers and efficiency in communication system. The notion of a highly secure and reliable ...

Description: It is the purpose of this thesis to show that the pragmatic philosophy is basically responsible for present-day developments in various teaching techniques.

Description: The problem of this thesis consists primarily of a bacteriological survey of the eating utensils of Hardin College Cafeteria and twenty-five other eating establishments in the city of Wichita Falls, Texas. This investigation was made primarily with reference to a determination of the possible presence of typhoid and related organisms, and secondarily to an investigation of the actual presence of those bacterial organisms associated with the more common outbreaks of food poisoning.