530 research outputs found
Evaluation of 2 possible further developments of the UK in-flight radiation warning meter for SSTS
A mass reduction of the moderator and the response to the nucleon flux, responsible for the tissue-star component of the total-dose equivalent rate using a high atomic number material, are discussed. Radiation situations at SST cruising altitudes (approximately 20 km) due to solar proton flares were simulated in the stratosphere and on the ground. Actual stratospheric situations due to galactic cosmic radiation with a limited range of quality factor values (2-4) were encountered during slow ascents by balloons to 36 km. Synthetic situations obtained from high and low energy acclerator radiations were used to obtain radiation distributions having a larger range of quality factor values (11/2-9) than experienced in the stratosphere. The measurements made in these simulations related to the directly ionizing, neutron and tissue-star components of dose-equivalent rate. Due to the restricted range of neutron spectra encountered in the stratosphere, a significant mass reduction of the moderator by 4 kg was made, with the moderator clad with cadmium or some other slow neutron absorber
Seat Belt Use Compliance in Kansas
Passenger vehicle occupant restraints are regarded as the easiest and the most effective way of reducing the number of highway fatalities. Strong vehicle occupant protection enforcement laws are regarded as the most effective way to increase seat belt use. The increase in restraint use in the United States and other countries has been largely attributed to mandatory seat belt use legislation. Many fatalities and injuries in motor vehicle crashes could be avoided if more passengers used their seat belts. Studies have shown that primary laws have been more effective in seat belt use compliance than secondary laws. Also, legislation has been found to be more effective in increasing seat belt use than educational or incentive programs in the absence of legislation. The United States has been lagging behind other developed countries in enacting strong seat belts use laws and enforcement strengthening. In Kansas, the seat belt usage compliance rate was 60% in 2000, which was far below the national average of 71%. The seat belt fine for Kansas is among the lowest in the US and is regarded by the National Highway Traffic Safety Administration (NHTSA) as not adequate. In Kansas, the younger child’s compliance rate is the highest while the older child’s compliance rate is the lowest among vehicle occupants’ groups. Pickup truck occupants consistently had the lowest compliance rates as compared to cars, sports utility vehicles (SUVs), and vans
Frequency-doubled Nd:YAG MOPA laser system with programmable rectangular pulses up to 200 microseconds
A compact frequency-doubled diode-pumped Nd:YAG master-oscillator
power-amplifier laser system with programmable microsecond pulse length has
been developed. Analog pulse shaping of the output from a single-frequency
continuous-wave Nd:YAG oscillator, and subsequent amplification, allowed the
generation of rectangular pulses with pulse lengths on the order of the Nd:YAG
fluorescence lifetime. Temporally flat-top pulses of 1064 nm light with 520 mJ
pulse energy, 2.6 kW peak power, and 200 s duration, with linewidth below
10 kHz, were obtained at a repetition rate of 2 Hz. Second harmonic generation
in a LBO crystal yielded pulses of 262 mJ and 1.3 kW peak power at 532 nm. The
peak power can be maintained within 2.9% over the duration of the laser pulse,
and long-term intensity stability of 1.1% was observed. The spatially flat-top
beam at 1064 nm used in the amplifier is converted to a Gaussian beam at 532 nm
with beam quality factor during the second harmonic generation.
This system has potential as a pump source for Ti:sapphire, dye, or optical
parametric amplifiers to generate tunable high-power single-frequency radiation
for applications in precision measurements and laser slowing.Comment: 9 pages, 5 figure
SmallTalk: Using tangible interactions to gather feedback from children
Gathering opinions from young children is challenging and different methods have been explored. In this paper we investigated how tangible devices can be used to gather feedback from children in the context of a theater performance. We introduce SmallTalk, a tangible survey system designed for use within a theater space to capture what children, aged 4 to 9, thought of a live performance they had just seen. We describe how the system was designed to build on previous feedback methods that had been tried; while at the same time meeting the constraints of the challenging theater context. We present results from seven deployments of SmallTalk and based on these we briefly discuss its value as a method for evaluating the theater performance. We then look at how the results validated the system design and present several design implications that more generally relate to tangible feedback systems for children
Low Dopamine D2/D3 Receptor Availability is Associated with Steep Discounting of Delayed Rewards in Methamphetamine Dependence.
BackgroundIndividuals with substance use disorders typically exhibit a predilection toward instant gratification with apparent disregard for the future consequences of their actions. Indirect evidence suggests that low dopamine D2-type receptor availability in the striatum contributes to the propensity of these individuals to sacrifice long-term goals for short-term gain; however, this possibility has not been tested directly. We investigated whether striatal D2/D3 receptor availability is negatively correlated with the preference for smaller, more immediate rewards over larger, delayed alternatives among research participants who met DSM-IV criteria for methamphetamine (MA) dependence.MethodsFifty-four adults (n = 27 each: MA-dependent, non-user controls) completed the Kirby Monetary Choice Questionnaire, and underwent positron emission tomography scanning with [(18)F]fallypride.ResultsMA users displayed steeper temporal discounting (p = 0.030) and lower striatal D2/D3 receptor availability (p < 0.0005) than controls. Discount rate was negatively correlated with striatal D2/D3 receptor availability, with the relationship reaching statistical significance in the combined sample (r = -0.291, p = 0.016) and among MA users alone (r = -0.342, p = 0.041), but not among controls alone (r = -0.179, p = 0.185); the slopes did not differ significantly between MA users and controls (p = 0.5).ConclusionsThese results provide the first direct evidence of a link between deficient D2/D3 receptor availability and steep temporal discounting. This finding fits with reports that low striatal D2/D3 receptor availability is associated with a higher risk of relapse among stimulant users, and may help to explain why some individuals choose to continue using drugs despite knowledge of their eventual negative consequences. Future research directions and therapeutic implications are discussed
Imaging Modalities for Cervical Spondylotic Stenosis and Myelopathy
Cervical spondylosis is a spectrum of pathology presenting as neck pain, radiculopathy, and myelopathy or all in combination. Diagnostic imaging is essential to diagnosis and preoperative planning. We discuss the modalities of imaging in common practice. We examine the use of imaging to differentiate among central, subarticular, and lateral stenosis and in the assessment of myelopathy
Mineral rich algae with pine bark improved pain, physical function and analgesic use in mild-knee joint osteoarthritis, compared to Glucosamine: a randomized controlled pilot trial
IntroductionOsteoarthritis (OA) is characterised by synovial joint pain, functional disability and affects ∼13% of people worldwide, of which ∼16-27% report Knee-OA (KOA). Glucosamine (Glu) is the most widely used nutraceutical treatment for OA despite a lack of scientific consensus, therefore alternative nutraceutical treatments are required. The aim of this study was to investigate the effect of Lithothamnion species, seawater-derived magnesium and pine bark (Aq+) on pain, symptoms and improve physical function in symptomatic (sKOA), compared to Glu.Methods358 participants were screened. In a double-blinded crossover pilot-trial, sKOA participant (n = 30) were randomly assigned to either the Glu group (2000 mg day-1) or Aq+ (3056 mg day-1) for 12 weeks (clinicaltrials.gov:NCT03106584). The Knee Injury and Osteoarthritis Outcome Score was used to assess subjective pain and symptoms. Timed-up-and-Go (TuG) and Six minute walking distance were used to assess functional change and analgesic use was recorded.ResultsAq+ improved pain, with a large effect (P < 0.01, d’ = 0.73, 95%CI 0.201-1.265) and no change for Glu (d’ = 0.38, P = 0.06). Only Aq+ improved pain (P < 0.05) for males (d’ = 0.91, 95%CI 0.162-1.667) and females (d’ = 0.55, 95%CI 0.210-1.299). In females, Aq+ improved TuG by -7.02% (d’ = 0.92, 95%CI 1.699-0.141) while Glu worsened performance by 4.18% (P = 0.04). Aq+ reduced analgesia by 71.6%, compared to Glu (P = 0.02; d’ = 0.82, 95%CI 1.524-0.123). Aq+ was superior to Glu at improving pain, KOOS subscales, physical function and analgesia use in mild-sKOA. Given these data, Aq+ should be considered as a supplementary treatment for early-stage-KOA and may have the potential to reduce use of pain medication, although larger replication studies are required
The cumulative and residual changes in eccentric knee flexor strength indices following soccer-specific treadmill running: novel considerations of angle specific torque.
Multiple Myeloma: A Review of Imaging Features and Radiological Techniques
The recently updated Durie/Salmon PLUS staging system published in 2006 highlights the many advances that have been made in the imaging of multiple myeloma, a common malignancy of plasma cells. In this article, we shall focus primarily on the more sensitive and specific whole-body imaging techniques, including whole-body computed tomography, whole-body magnetic resonance imaging, and positron emission computed tomography. We shall also discuss new and emerging imaging techniques and future developments in the radiological assessment of multiple myeloma
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