Atomic hydrogen maser measurements with wall surfaces of carbon tetrafluoride

The principal objectives of the Smithsonian Astrophysical Observatory cold maser research programs are given. This work is aimed principally at understanding more about the interaction of hydrogen atoms with wall coatings of fluorinated ethylene propylene (Dupont Teflon FEP-120 co-polymer) and of carbon tetrafluoride (CE4). The principal measured quantity in these experiments is the wall shift of the maser's output frequency. The wall shift per atomic collision was calculated from the measured wall frequency shift. This assumes that the wall surface area is smooth on a molecular scale

The clinical- and cost-effectiveness of functional electrical stimulation and ankle-foot orthoses for foot drop in Multiple Sclerosis: a multicentre randomized trial

Objective: To compare the clinical- and cost-effectiveness of ankle-foot orthoses (AFOs) and functional electrical stimulation (FES) over 12 months in people with Multiple Sclerosis with foot drop. Design: Multicentre, powered, non-blinded, randomized trial. Setting: Seven Multiple Sclerosis outpatient centres across Scotland. Subjects: Eighty-five treatment-naïve people with Multiple Sclerosis with persistent (>three months) foot drop. Interventions: Participants randomized to receive a custom-made, AFO (n = 43) or FES device (n = 42). Outcome measures: Assessed at 0, 3, 6 and 12 months; 5-minute self-selected walk test (primary), Timed 25 Foot Walk, oxygen cost of walking, Multiple Sclerosis Impact Scale-29, Multiple Sclerosis Walking Scale-12, Modified Fatigue Impact Scale, Euroqol five-dimension five-level questionnaire, Activities-specific Balance and Confidence Scale, Psychological Impact of Assistive Devices Score, and equipment and National Health Service staff time costs of interventions. Results: Groups were similar for age (AFO, 51.4 (11.2); FES, 50.4(10.4) years) and baseline walking speed (AFO, 0.62 (0.21); FES 0.73 (0.27) m/s). In all, 38% dropped out by 12 months (AFO, n = 21; FES, n = 11). Both groups walked faster at 12 months with device (P < 0.001; AFO, 0.73 (0.24); FES, 0.79 (0.24) m/s) but no difference between groups. Significantly higher Psychological Impact of Assistive Devices Scores were found for FES for Competence (P = 0.016; AFO, 0.85(1.05); FES, 1.53(1.05)), Adaptability (P = 0.001; AFO, 0.38(0.97); FES 1.53 (0.98)) and Self-Esteem (P = 0.006; AFO, 0.45 (0.67); FES 1 (0.68)). Effects were comparable for other measures. FES may offer value for money alternative to usual care. Conclusion: AFOs and FES have comparable effects on walking performance and patient-reported outcomes; however, high drop-outs introduces uncertainty

Drawing the answers: sketching to support free and probed recall by child witnesses and victims with Autism Spectrum Disorder

The success of witness interviews in the criminal justice system depends on the accuracy of information obtained, which is a function of both amount and quality of information. Attempts to enhance witness retrieval such as mental reinstatement of context have been designed with typically developed adults in mind. In this paper, the relative benefits of mental and sketch reinstatement mnemonics are explored with both typically developing children and children with autism. Children watched a crime event video, and their retrieval of event information was examined in free and probed recall phases of a cognitive interview. As expected, typically developing children recalled more correct information of all types than children with autism during free and probed recall phases. Sketching during free recall was more beneficial for both groups in both phases in reducing the amount of incorrect items, but the relative effect of sketching on enhancing retrieval accuracy was greater for children with autism. The results indicate the benefits of choosing retrieval mnemonics that are sensitive to the specific impairments of autistic individuals, and suggest that retrieval accuracy during interviews can be enhanced, in some cases to the same level as that of typically developing individuals

New Clock Comparison Searches for Lorentz and CPT Violation

We present two new measurements constraining Lorentz and CPT violation using the Xe-129 / He-3 Zeeman maser and atomic hydrogen masers. Experimental investigations of Lorentz and CPT symmetry provide important tests of the framework of the standard model of particle physics and theories of gravity. The two-species Xe-129 / He-3 Zeeman maser bounds violations of CPT and Lorentz symmetry of the neutron at the 10^-31 GeV level. Measurements with atomic hydrogen masers provide a clean limit of CPT and Lorentz symmetry violation of the proton at the 10^-27 GeV level.Comment: 11 pages, 5 figures. To appear in the Proceedings of the 3rd International Symposium on Symmetries in Subatomic Physic

Heat-induced alterations in cashew allergen solubility and IgE binding

AbstractCashew nuts are an increasingly common cause of food allergy. We compare the soluble protein profile of cashew nuts following heating. SDS-PAGE indicate that heating can alter the solubility of cashew nut proteins. The 11S legumin, Ana o 2, dominates the soluble protein content in ready to eat and mildly heated cashew nuts. However, we found that in dark-roasted cashew nuts, the soluble protein profile shifts and the 2S albumin Ana o 3 composes up to 40% of the soluble protein. Analysis of trypsin-treated extracts by LC/MS/MS indicate changes in the relative number and intensity of peptides. The relative cumulative intensity of the 5 most commonly observed Ana o 1 and 2 peptides are altered by heating, while those of the 5 most commonly observed Ana o 3 peptides remaine relatively constant. ELISA experiments indicate that there is a decrease in rabbit IgG and human serum IgE binding to soluble cashew proteins following heating. Our findings indicate that heating can alter the solubility of cashew allergens, resulting in altered IgE binding. Our results support the use of both Ana o 2 and Ana o 3 as potential cashew allergen diagnostic targets

Hydrogen Maser Clock (HMC) Experiment

The Hydrogen Maser Clock (HMC) project was originally conceived to fly on a reflight of the European Space Agency (ESA) free flying platform, the European Recoverable Carrier (EURECA) that had been launched into space and recovered by NASA's Space Transportation System (STS). A Phase B study for operation of HMC as one of the twelve EURECA payload components was begun in July 1991, and completed a year later. Phase C/D of HMC began in August 1992 and continued into early 1995. At that time ESA decided not to refly EURECA, leaving HMC without access to space. Approximately 80% of the flight support electronics are presently operating the HMC's physics package in a vacuum tank at the Smithsonian Astrophysical Observatory, and are now considered to be well-tested flight electronics. The package will continue to be operated until the end of 1997 or until a flight opportunity becomes avaiable. Appendices: letters and trip report; proceedings of the symposium on frequency standards and metrology; milli-celsius-stability thermal control for an orbiting frequency standard

High Precision Time Transfer in Space with a Hydrogen Maser on MIR

An atomic hydrogen maser clock system designed for long term operation in space will be installed on the Russian space station Mir, in late 1997. The H-maser's frequency stability will be measured using pulsed laser time transfer techniques. Daily time comparisons made with a precision of better than 100 picoseconds will allow an assessment of the long term stability of the space maser at a level on the order of 1 part in 10(sup 15) or better. Laser pulse arrival times at the spacecraft will be recorded with a resolution of 10 picoseconds relative to the space clock's time scale. Cube corner reflectors will reflect the pulses back to the Earth laser station to determine the propagation delay and enable comparison with the Earth-based time scale. Data for relativistic and gravitational frequency corrections will be obtained from a Global Positioning System (GPS) receiver

Validity of the activPAL3 activity monitor in people moderately affected by Multiple Sclerosis

Background: Walking is the primary form of physical activity performed by people with Multiple Sclerosis (MS), therefore it is important to ensure the validity of tools employed to measure walking activity. The aim of this study was to assess the criterion validity of the activPAL3 activity monitor during overground walking in people with MS.\ud Methods: Validity of the activPAL3 accelerometer was compared to video observation in 20 people moderately affected by MS. Participants walked 20-30m twice along a straight quiet corridor at a comfortable speed.\ud Results: Inter-rater reliability of video observations was excellent (all intraclass correlations > 0.99). The mean difference (activPAL3- mean of raters) was -4.70 ± 9.09, -4.55 s ± 10.76 and 1.11 s ± 1.11 for steps taken, walking duration and upright duration respectively. These differences represented 8.7, 10.0 and 1.8% of the mean for each measure respectively. The activPAL3 tended to underestimate steps taken and walking duration in those who walked at cadences of ≤ 38 steps/minute by 60% and 47% respectively.\ud Discussion: The activPAL3 is valid for measuring walking activity in people moderately affected by MS. It is accurate for upright duration regardless of cadence. In participants with slow walking cadences, outcomes of steps taken and walking duration should be interpreted with caution