104 research outputs found
Report on the method for determining the location of the polar vortex boundary region
To determine the boundary region of the polar vortex objectively using the PV distribution on isentropic surfaces, the equivalent latitude(Eql) of the polar vortex boundary was calculated using a slightly modified form of the technique of E.R. Nash et al.(J. Geophys. Res., 101D, 9471, 1996). Using the NCEP/NCAR reanal- ysis data, the Eql of the polar vortex boundary region in the winter of 1999/2000 was calculated, and compared with the ozone mixing ratio in the lower stratosphere over Eureka observatory(80°N , 86°W ). The results indicate that this method determines the boundary region of the polar vortex well
Apparent stratospheric ozone loss rate over Eureka in 1994/95, 1995/96, and 1996/97 inferred from ECC ozonesonde observations
Many ECC-type ozonesondes were launched at the Canadian Arctic Eureka observatory(80°N , 86°W ), one of the most northern stations in the Arctic, during winters from 1993/94 to 2001/02, and the temporal evolutions of the vertical ozone profiles were obtained in detail. The lower stratospheric temperature over Eureka was very low inside the polar vortex and the largest ozone loss was observed in 1999/2000, as reported in a previous paper. Similarly, Eureka was often or persistently inside the vortex in the lower stratosphere(around the 470K isentropic surface level) in the winters of 1994/95, 1995/96, and 1996/97. Very low temperatures were observed inside the vortex in the lower stratosphere over Eureka, as indicated by detection of PSCs by Mie lidar. Observations of tracers(N_2O, total reactive nitrogen species(NOy), and others) inside the vortex during these winters using an ER-2 aircraft and balloons indicated that the effect of air parcel mixing across the vortex edge was minimal, based on the tracer-tracer relationship(e.g., Y. Kondo et al.; J. Geophys. Res., 104D, 8215, 1999). Therefore, significant decreases of the in-travortex ozone mixing ratio in the lower stratosphere were considered to be chemical ozone losses due to chlorine activation of PSCs following diabatic descent. The apparent ozone loss rate inside the vortex over Eureka was estimated for each year. The rates ranged from 0.01 to 0.03ppmv/day, less than that observed in 1999/2000(0.04ppmv/day). The observations were conducted at a single station; however, the apparent ozone loss rate over Eureka inside the vortex each year agrees with loss rates obtained in other studies
Recommended from our members
Prevalence and cumulative incidence of autism spectrum disorders and the patterns of co-occurring neurodevelopmental disorders in a total population sample of 5-year-old children.
BackgroundsWhether there is a true increase in autism spectrum disorder (ASD) frequency or not remains unclear. Additionally, the rates of co-existing neurodevelopmental disorders (NDD) in a total population sample has not been fully examined before. Therefore, using a total population sample in Japan, we aimed to estimate the prevalence and cumulative incidence of autism spectrum disorder (ASD) annually, to determine whether there is a true increase in ASD prevalence by estimating the cumulative incidence of ASD annually, and to examine the rates of co-existing neurodevelopmental disorders (NDD).MethodIn this cross-sectional sequential design study, all 5-year-old children in the catchment area underwent the screening annually from the year 2013-2016. Screen-positive children were invited to participate in a comprehensive assessment, including child and parent interview, behavioral observation, and cognitive and motor function testing. All cases were reviewed by a multidisciplinary research team.ResultsCaregivers of 3954 children returned the screening, among which 559 children underwent the assessment with 87 children receiving an ASD diagnosis. Adjusted ASD prevalence was 3.22% (95% confidence interval (CI) 2.66-3.76%). The male to female ratio of the crude prevalence was 2.2:1. The cumulative incidence of ASD up to 5 years of age for the total study years was 1.31% (95% CI 1.00-1.62%). A generalized linear model revealed no significant linear trends in 5-year cumulative incidence over the study years. Only 11.5% of children had ASD alone; the remaining 88.5% were found to have at least one co-existing NDD.LimitationsModest sample size for a total population study.ConclusionsOur findings demonstrate the stability of the 5-year cumulative incidence of ASD, implying no true rise in ASD incident cases over the 4-year study period in the study catchment area. High rates of co-existing NDDs reflect the importance of investigating broad developmental challenges in children with ASD
Effect of Radiological Countermeasures on Subjective Well-Being and Radiation Anxiety after the 2011 Disaster: The Fukushima Health Management Survey
After the Fukushima Daiichi Nuclear Power Station accident in 2011, concerns about radiation exposure and decline in subjective well-being have been reported. To tackle these problems, various countermeasures in relation to radiation have been implemented. In this study, we comprehensively evaluated the effects of radiological countermeasures on subjective well-being (e.g., satisfaction with life (SWL) and emotional well-being) and radiation anxiety, through a questionnaire survey targeting Fukushima residents (N = 1023). Propensity scores matching was applied to evaluate significant effects of radiological countermeasures on subjective well-being and radiation anxiety. Among the radiological countermeasures, thyroid examination, whole body counter, and air dose monitoring showed the highest proportions of participation, utilization, and useful evaluation, suggesting a high degree of public attention focused on these countermeasures. The basic survey was associated with significant increases in SWL and self-rated health (SH). Thyroid examination was significantly associated with not only a reduction in radiation anxiety but also an increase of emotional stress, suggesting the importance of careful design of system and detailed communication. Food inspection was associated with deterioration in SH. Those who utilized explanatory meetings showed increases in sadness, worry, and radiation anxiety, indicating that additional attention is required of the experts and authorities involved in explanatory meetings
Study on the reusability of fluorescent nuclear track detectors using optical bleaching
Fluorescent nuclear track detectors (FNTDs) based on AlO:C,Mg
crystals are luminescent detectors that can be used for dosimetry and detection
of charged particles and neutrons. These detectors can be utilised for imaging
applications where a reasonably high track density, approximately of the order
of 1 tracks in an area of 100 100 m, is
required. To investigate the reusability of FNTDs for imaging applications, we
present an approach to perform optical bleaching under the required track
density conditions. The reusability was assessed through seven
irradiation-bleaching cycles. For the irradiation, the studied FNTD was exposed
to alpha-particles from an Am radioactive source. The optical bleaching
was performed by means of ultraviolet laser light with a wavelength of 355 nm.
Three dedicated regions on a single FNTD with different accumulated track
densities and bleaching conditions were investigated. After every
irradiation-bleaching cycle, signal-to-noise ratio was calculated to evaluate
FNTD performance. It is concluded that FNTDs can be reused at least seven times
for applications where accumulation of a high track density is required
Protocol for a Randomized, Crossover Trial : ISCHIA study
Objective: Intermittent-scanning continuous glucose monitoring (isCGM) is widely used in type 1 diabetes (T1D) patients; however, the education required to prevent hypoglycemia by using isCGM is not established. This study examines the combined effect of isCGM device usage and the education to reduce the time in hypoglycemia in comparison to conventional self-monitoring of blood glucose (SMBG).
Methods: The Effect of Intermittent-Scanning Continuous Glucose Monitoring to Glycemic Control Including Hypoglycemia and Quality of Life of Patients with Type 1 Diabetes Mellitus Study (ISCHIA Study), a randomized, crossover trial, enrolls 104 T1D patients (age, 20-74 years) with T1D. Participants are randomized to use isCGM combined with structured education (Intervention period) or SMBG (Control period) for 84 days, followed by the other for a further 84 days. During the Intervention period, participants have access to the sensor glucose levels and trend arrow of the device. During the Control period, participants conduct SMBG at least three times a day, and retrospective CGM is used to record the blinded sensor glucose levels. The primary endpoint is the decrease of time in hypoglycemia ( < 70 mg/dL) per day (hour/day) during the Intervention period compared with the Control period. The secondary endpoints include other indices of glycemic control, glycoalbumin, accuracy of isCGM, diabetes-related quality of life (QOL), adherence, and cost-effectiveness. The study protocol has received Certified Review Board (CRB) approval from National Hospital Organization Osaka National Hospital (N2018002, February 14, 2019). This study is carried out in accordance with the Declaration of Helsinki and the Clinical Trials Act. The findings will be published in peer-reviewed journals.
Conclusion: The ISCHIA study will contribute to the standardization of patient education regarding the prevention of hypoglycemia by using isCGM
カン シュヨウ ニ タイスル ソクセン オンネツ リョウホウ ノ ジッケンテキ ケンキュウ ジセイ リュウシ オ ヒョウテキ トシタ ユウドウ カネツホウ ニヨル ケントウ
- …