Space processes for extended low-G testing

Results of an investigation of verifying the capabilities of space processes in ground based experiments at low-g periods are presented. Limited time experiments were conducted with the processes. A valid representation of the complete process cycle was achieved at low-g periods ranging from 40 to 390 seconds. A minimum equipment inventory, is defined. A modular equipment design, adopted to assure low cost and high program flexibility, is presented as well as procedures and data established for the synthesis and definition of dedicated and mixed rocket payloads

Experimental Limit on the Cosmic Diffuse Ultra-high Energy Neutrino Flux

We report results from 120 hours of livetime with the Goldstone Lunar Ultra-high energy neutrino Experiment (GLUE). The experiment searches for <10 ns microwave pulses from the lunar regolith, appearing in coincidence at two large radio telescopes separated by 22 km and linked by optical fiber. Such pulses would arise from subsurface electromagnetic cascades induced by interactions of >= 100 EeV neutrinos in the lunar regolith. No candidates are yet seen, and the implied limits constrain several current models for ultra-high energy neutrino fluxes.Comment: 4 pages, 4 figures, revtex4 style. New intro section, Fig. 2, Fig 4; in final PRL revie

FORCES AND MOMENTS AT THE L4/L5 VERTEBRAL LEVEL WHILE FORWARD BENDING IN A SUPPORTED POSTURE

INTRODUCTION Chronic lower back pain has been associated with improper body mechanics while lifting. Forces and moments imposed on the lumbar spine have been investigated while performing a variety of lifting tasks to better understand the mechanical nature of injury to this region. Research focused on the injured patient has been sparse. The purpose of this line of study is to determine the mechanical effects at the L4/L5 vertebral level while using a supported lifting posture. METHODS Nine males (mean age 49.6± 9.7 yrs) participating in a chronic back pain program volunteered as subjects. Each subject performed two styles of lift while removing a wash cloth from a support structure constructed to simulate the dimensions of a washing machine. The lifting postures were(1) a common bowed-back lift performed with both feet in a stationary position, and (2) a rotation about the hip joint of the weight-bearing leg while the contra-lateral leg was allowed to rotate posteriorly to maintain the standing curvature of the spine ("golfer's lift"). Data was recorded using a 60 Hz S-VHS video camcorder and a Bertec force platform (500 Hz). A sagittal plane inverse dynamic model was developed and used to calculate forces and moments imparted on the L4/L5 vertebral level. Self-reported subjective ratings of lower back pain were recorded on an ordinal scale from 0 to 10. RESULTS Two profiles of lifts were identified based on the direction of the net moment at L4/L5. Negative moments, requiring a contraction of the spinal extensors to maintain equilibrium, were found in the majority of subjects while performing the bowed-back posture, while only in one subject performing the golfer's lift posture. Positive moments, resulting in an unloading of the spinal extensors, were found in the majority of subjects while performing the golfer's lift posture. Significant differences F(1.68) = 64.74, p < .001] were found between the peak L4/L5 moments for the two lifting postures. A Wilcoxon matched-pairs signed-ranks test revealed a significant increase (

Visualisation of bacterial behaviour using tapping-mode atomic force microscopy

Ex-situ and in-situ Tapping Mode AFM were used to investigate responses of attachedbacteria to stressful conditions. For ex-situ measurements, the AFM was equipped with acustomised re-positioning stage and sample mount to permit re-examination of the same surfacearea. For in-situ measurements, the inoculated pyrite coupon was immersed in solution in a flowthrough cell. Initial experiments using Sulfobacillus thermosulfidooxidans indicated that increasedacidity promoted EPS production but increased salinity resulted in cell detachment

Peptide redesign for inhibition of the complement system: Targeting age-related macular degeneration.

PurposeTo redesign a complement-inhibiting peptide with the potential to become a therapeutic for dry and wet age-related macular degeneration (AMD).MethodsWe present a new potent peptide (Peptide 2) of the compstatin family. The peptide is developed by rational design, based on a mechanistic binding hypothesis, and structural and physicochemical properties derived from molecular dynamics (MD) simulation. The inhibitory activity, efficacy, and solubility of Peptide 2 are evaluated using a hemolytic assay, a human RPE cell-based assay, and ultraviolet (UV) absorption properties, respectively, and compared to the respective properties of its parent peptide (Peptide 1).ResultsThe sequence of Peptide 2 contains an arginine-serine N-terminal extension (a characteristic of parent Peptide 1) and a novel 8-polyethylene glycol (PEG) block C-terminal extension. Peptide 2 has significantly improved aqueous solubility compared to Peptide 1 and comparable complement inhibitory activity. In addition, Peptide 2 is more efficacious in inhibiting complement activation in a cell-based model that mimics the pathobiology of dry AMD.ConclusionsWe have designed a new peptide analog of compstatin that combines N-terminal polar amino acid extensions and C-terminal PEGylation extensions. This peptide demonstrates significantly improved aqueous solubility and complement inhibitory efficacy, compared to the parent peptide. The new peptide overcomes the aggregation limitation for clinical translation of previous compstatin analogs and is a candidate to become a therapeutic for the treatment of AMD

Processes for space manufacturing - Definition of criteria for process feasibility and effectiveness Final report

Feasibility criteria and research and development program for manufacturing processes in orbital environment

Observation of the Askaryan Effect: Coherent Microwave Cherenkov Emission from Charge Asymmetry in High Energy Particle Cascades

We present the first direct experimental evidence for the charge excess in high energy particle showers predicted nearly 40 years ago by Askaryan. We directed bremsstrahlung photons from picosecond pulses of 28.5 GeV electrons at the SLAC Final Focus Test Beam facility into a 3.5 ton silica sand target, producing electromagnetic showers several meters long. A series of antennas spanning 0.3 to 6 GHz were used to detect strong, sub-nanosecond radio frequency pulses produced whenever a shower was present. The measured electric field strengths are consistent with a completely coherent radiation process. The pulses show 100% linear polarization, consistent with the expectations of Cherenkov radiation. The field strength versus depth closely follows the expected particle number density profile of the cascade, consistent with emission from excess charge distributed along the shower. These measurements therefore provide strong support for experiments designed to detect high energy cosmic rays and neutrinos via coherent radio emission from their cascades.Comment: 10 pages, 4 figures. Submitted to Phys. Rev. Let

Time-Domain Measurement of Broadband Coherent Cherenkov Radiation

We report on further analysis of coherent microwave Cherenkov impulses emitted via the Askaryan mechanism from high-energy electromagnetic showers produced at the Stanford Linear Accelerator Center (SLAC). In this report, the time-domain based analysis of the measurements made with a broadband (nominally 1-18 GHz) log periodic dipole array antenna is described. The theory of a transmit-receive antenna system based on time-dependent effective height operator is summarized and applied to fully characterize the measurement antenna system and to reconstruct the electric field induced via the Askaryan process. The observed radiation intensity and phase as functions of frequency were found to agree with expectations from 0.75-11.5 GHz within experimental errors on the normalized electric field magnitude and the relative phase; 0.039 microV/MHz/TeV and 17 deg, respectively. This is the first time this agreement has been observed over such a broad bandwidth, and the first measurement of the relative phase variation of an Askaryan pulse. The importance of validation of the Askaryan mechanism is significant since it is viewed as the most promising way to detect cosmogenic neutrino fluxes at E > 10^15 eV.Comment: 10 pages, 9 figures, accepted by Phys. Rev.