Andes Large-area PArticle detector for Cosmic-ray physics and Astronomy (ALPACA) is an international experiment that applies southern very-high-energy (VHE) gamma-ray astronomy to determine the ...origin of cosmic rays around the knee energy region (10
15
eV − 10
16
eV). The experiment consists of an air shower (AS) array with a surface of 83,000m
2
and an underground water Cherenkov muon detector (MD) array covering 5,400m
2
. The experimental site is at the Mt. Chacaltaya plateau in La Paz, Bolivia, with an altitude of 4,740m corresponding to 572g/cm
2
atmospheric thickness. As the prototype experiment of ALPACA, the ALPAQUITA experiment aims to begin data acquisition in late 2021. The ALPAQUITA array consists of a smaller AS array (18,450m
2
) and underground MD (900m
2
), which are now under construction. ALPAQUITA’s sensitivity to gamma-ray sources is evaluated with Monte Carlo simulations. The simulation finds that five gamma-ray sources observed by H.E.S.S. and HAWC experiments will be detected by ALPAQUITA beyond 10TeV and ne out of these five - HESS J1702-420A - above 300 TeV in one calendar year observation. The latter finding means that scientific discussions can be made on the emission mechanism of gamma rays beyond 100TeV from southern sources on the basis of the observational results of this prototype experiment.
Background. Recent findings of neuroimaging studies indicate that reading aloud and arithmetic calculation activate bilateral dorsolateral prefrontal cortex of humans. The purpose of this study was ...to measure the effect of reading aloud and arithmetic calculation, by elderly people who were clinically diagnosed with dementia Alzheimer type, on their brain functions and activities of daily living. Methods. Sixteen experimental and 16 age- and Mini-Mental State Examination score-matched control subjects participated. The participants in the experimental group were asked to perform a training program using learning tasks in reading and arithmetic for 2–6 days a week. The function of the frontal cortex of the subjects was assessed by FAB at bedside (Frontal Assessment Battery). Results. After 6 months of training, the FAB score of the experimental group showed a statistically significant improvement. The FAB score of the control group decreased slightly over the 6-month period, and the difference between the scores of the experimental and control groups was statistically significant. We also observed the restoration of communication and independence in the experimental group. Conclusion. Our results indicate that learning tasks of reading aloud and arithmetic calculation can be used for cognitive rehabilitation of dementia patients.
The ALPACA experiment is a new international project between Bolivia and Japan. It is going to consist of an 83,000 m2 surface air-shower array and a 5,400 m2 underground water Cherenkov muon ...detector array, and the experimental site is at Mt. Chacaltaya plateau at an altitude of 4,740 m. Its main target is to observe 100 TeV gamma rays and explore high-energy gamma-ray sources in the southern sky. This is because such high-energy gamma rays hold the key to identify the origin of cosmic rays at the knee region of the energy spectrum. So far many high-energy gamma-ray sources have been found in the southern sky. They are emitting gamma rays of several tens of TeV, so some of them could be PeVatrons which accelerate cosmic rays to PeV energy region in the Galaxy. By observing them in higher energy region, we will obtain new knowledge of cosmic-ray acceleration to the knee region, and discover new gamma-ray sources. As the prototype experiment of ALPACA, the ALPAQUITA experiment is now under construction. In a MC simulation, we found that ALPAQUITA has the ability of detecting bright gamma-ray sources in the southern hemisphere such as Vela X within 1 year.
Observation techniques of high-energy gamma rays using air showers have remarkably progressed via the Tibet AS
γ
, HAWC, and LHAASO experiments. These observations have significantly contributed to ...gamma-ray astronomy in the northern sky’s sub-PeV region. Moreover, in the southern sky, the ALPACA experiment is underway at 4,740 m altitude on the Chacaltaya plateau in Bolivia. This experiment estimates the gamma-ray flux from the difference between the number of on-source and off-source events by real data, utilizing the gamma-ray detection efficiency calculated through Monte Carlo simulations, which in turn depends on the hadronic interaction models. Even though the number of cosmic-ray background events can be experimentally estimated, this model dependence affects the estimation of gamma-ray detection efficiency. However, previous reports have assumed that the model dependence is negligible and have not included it in the error of gamma-ray flux estimation. Using ALPAQUITA, the prototype experiment of ALPACA, we quantitatively evaluated the model dependence on hadronic interaction models for the first time. We evaluate the model dependence on hadronic interactions as less than 3.6 % in the typical gamma-ray flux estimation performed by ALPAQUITA; this is negligible compared with other uncertainties such as energy scale uncertainty in the energy range from 6 to 300 TeV, which is dominated by the Monte Carlo statistics. This upper limit of 3.6 % model dependence is expected to apply to ALPACA.
Because most studies about the relationship between eating quickly and overweight/obesity have been cross-sectional, it is necessary to investigate prospectively the influence of eating quickly on ...anthropometric variables in order to examine the causal relationship. The aim of the present study was to investigate the impact of eating quickly on anthropometric variables among schoolgirls in a prospective cohort study.
We investigated 427 non-overweight/obese schoolgirls from fourth grade (aged 9 or 10 years) in Ina-town, Japan from 2004 to 2006. Physical examinations and a questionnaire survey were conducted in fourth grade and 3 years later (in seventh grade). Height, weight, percent body fat (%BF) and waist circumference (WC) were measured in physical examinations, and information on eating speed was collected in a questionnaire survey.
The differences in anthropometric variables (body mass index, %BF, WC and waist-to-height ratio) between fourth and seventh grade were significantly greater in girls who continued to eat quickly from fourth to seventh grade than in those who did not continue to eat quickly during this 3-year period. In contrast, these differences were not statistically significant in girls who ate quickly in fourth grade but not in seventh grade compared with those who did not continue to eat quickly during the 3-year period.
Eating quickly was associated with excess gains in anthropometric variables. The present study also suggested that stopping a habit of eating quickly prevents these excess gains in non-overweight/obese girls, which could contribute to the prevention of childhood overweight and obesity.
The American Diabetes Association recommended that only a single fasting plasma glucose of greater than or equal to 7.0 mmol/l should be used for diagnosing diabetes in epidemiological studies and ...did not recommend using a 2-h oral glucose tolerance test. We evaluated the effect of diagnostic changes on the prevalence of diabetes and on the choice of subjects diagnosed with diabetes.
Existing epidemiological data collected from Asian people between 30 and 89 years of age, was re-analysed separately in 11 population-based studies (n = 17,666), 6 pre-selected hyperglycaemic cohorts (n = 12,221) and one suspected diabetic cohort (n = 8382).
Among the 11 population-based studies, the new fasting glucose criteria resulted in an overall reduction of 1.8% in the prevalence of diabetes, which ranged from a reduction of 4.8% to an increase of 1.7% in the different studies. Of 1215 subjects diagnosed with diabetes by either criteria, only 449 met both criteria, a concordance of 37%. More than half of the diabetic subjects had isolated post-challenge hyperglycaemia and three quarters of the subjects with impaired glucose tolerance, according to the 2-h glucose criteria, were normal according to the fasting glucose criteria. Subjects diagnosed as diabetic based only on the 2-h glucose criteria were, on average, older than those with diabetes according to the fasting criteria.
The fasting and the 2-h glucose criteria diagnose different groups of subjects. It would therefore be inappropriate to use the fasting glucose criteria alone for screening diabetes in Asian populations.
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