Asymptotic Probability Density Function of Nonlinear Phase Noise

The asymptotic probability density function of nonlinear phase noise, often called the Gordon-Mollenauer effect, is derived analytically when the number of fiber spans is very large. The nonlinear phase noise is the summation of infinitely many independently distributed noncentral chi-square random variables with two degrees of freedom. The mean and standard deviation of those random variables are both proportional to the square of the reciprocal of all odd natural numbers. The nonlinear phase noise can also be accurately modeled as the summation of a noncentral chi-square random variable with two degrees of freedom and a Gaussian random variable.Comment: 13 pages, 3 figure

Non-Gaussian Statistics of the Soliton Timing Jitter due to Amplifier Noise

Based on the first-order perturbation theory of soliton, the Gordon-Haus timing jitter induced by amplifier noise is found to be non-Gaussian distributed. Compared with Gaussian distribution given by the linearized perturbation theory, both frequency and timing jitter have larger tail probability. The timing jitter has a larger discrepancy to Gaussian distribution than that of frequency jitter.Comment: 3 pages, 4 figures, submitted to Optics Letter

Snatch trajectory of elite level girevoy (Kettlebell) sport athletes and its implications to strength and conditioning coaching

Girevoy sport (GS) has developed only recently in the West, resulting in a paucity of English scientific literature available. The aim was to document kettlebell trajectory of GS athletes performing the kettlebell snatch. Four elite GS athletes (age = 29-47 years, body mass = 68.3-108.1 kg, height 1.72-1.89 m) completed one set of 16 repetitions with a 32.1 kg kettlebell. Trajectory was captured with the VICON motion analysis system (250 Hz) and analysed with VICON Nexus (1.7.1). The kettlebell followed a ‘C’ shape trajectory in the sagittal plane. Mean peak velocity in the upwards phase was 4.03 ± 0.20 m s –1, compared to 3.70 ± 0.30 m s–1 during the downwards phase, and mean radial error across the sagittal and frontal planes was 0.022 ± 0.006 m. Low error in the movement suggests consistent trajectory is important to reduce extraneous movement and improve efficiency. While the kettlebell snatch and swing both require large anterior-posterior motion, the snatch requires the kettlebell to be held stationary overhead. Therefore, a different coaching application is required to that of a barbell snatch

Computer control of a PBX washout plant

A fully automated, computer controlled plant has been designed specifically for safe removal of plastic bonded explosives (PBX) from obsolete military munitions. This PBX washout plant consists of a two stage delivery system and robotically operated high pressure waterjet lance. The assigned task was to develop control packages for each component. The first stage of the delivery system is a battery operated overhead trolley. Its control package consist of a dedicated computer, DC motor and custom positioning subprograms. The dedicated computer communicates through an infrared link to the operator\u27s computer. This link was developed due to requirements of a hazardous environment. Probable software solutions for the communication are presented given current system configurations. The trolley positions the munition directly above a hydraulically operated table - the second stage of the delivery system. This stage\u27s control package incorporates three closed loop, first order circuits and software. The table positions the munition for explosive removal by the waterjet. The robotic waterjet lance is hydraulically controlled through four closed loop, first order circuits. The concepts of its controlling software is presented to better understand the currently developed software

Phase Statistics of Soliton

The characteristic function of soliton phase jitter is found analytically when the soliton is perturbed by amplifier noise. In additional to that from amplitude jitter, the nonlinear phase noise due to frequency and timing jitter is also analyzed. Because the nonlinear phase noise is not Gaussian distributed, the overall phase jitter is also non-Gaussian. For a fixed mean nonlinear phase shift, the contribution of nonlinear phase noise from frequency and timing jitter decreases with distance and signal-to-noise ratio.Comment: 8 pages, submitted to JOSA

EST analysis of gene expression in early cleavage-stage sea urchin embryos

A set of 956 expressed sequence tags derived from 7-hour (mid-cleavage) sea urchin embryos was analyzed to assess biosynthetic functions and to illuminate the structure of the message population at this stage. About a quarter of the expressed sequence tags represented repetitive sequence transcripts typical of early embryos, or ribosomal and mitochondrial RNAs, while a majority of the remainder contained significant open reading frames. A total of 232 sequences, including 153 different proteins, produced significant matches when compared against GenBank. The majority of these identified sequences represented ‘housekeeping’ proteins, i.e., cytoskeletal proteins, metabolic enzymes, transporters and proteins involved in cell division. The most interesting finds were components of signaling systems and transcription factors not previously reported in early sea urchin embryos, including components of Notch and TGF signal transduction pathways. As expected from earlier kinetic analyses of the embryo mRNA populations, no very prevalent protein-coding species were encountered; the most highly represented such sequences were cDNAs encoding cyclins A and B. The frequency of occurrence of all sequences within the database was used to construct a sequence prevalence distribution. The result, confirming earlier mRNA population analyses, indicated that the poly(A) RNA of the early embryo consists mainly of a very complex set of low-copy-number transcripts

Removal of toxic contaminates from polluted soil and water via bioremediation utilizing bacillus spores [abstract]

Atrazine, a widely used herbicide in North America, is one of the known pollutants that pose a potential threat to human health. The addition of naturally occurring degradative bacteria that can remediate these pollutants has been promising. The soil bacterium Pseudomonas sp. strain ADP produces the enzyme AtzA which modifies atrazine to the benign hydroatrazine. However, the current use of bacteria in bioremediation is limited. These bacteria need to compete for nutrients with the native populations of microorganisms in the contaminated soil to survive and to maintain a degradative population. Bacterial endospores are naturally resistant to harmful environments, such as acidic soil, heat, and dessication; and have the ability to persist in soil for long periods of time. We wanted to utilize the Bacillus spore as a vehicle to deliver degradative enzymes, such as AtzA, into the soil and allow the tethered enzymes to persist over time. We utilized two methods for the tethering of enzymes to the spore surface. The first method being a genetic fusion of degradative enzymes to the exosporium of Bacillus endospores, and the second method being a chemical linkage to the outer layers of the Bacillus exosporium. INVENTOR(S): Brian M. Thompson; George C. Stewart; and Chun-Ho Lin CONTACT INFO: Harriet F. Francis, MS; J.D.; [email protected]; 573.884.0374 Per Stromhaug, Ph.D., MBA; [email protected]; 573.884.355