10,480 research outputs found
Monte Carlo calculations of energy depositions and radiation transport. Volume 1 - Validation of COHORT codes
Monte Carlo codes for IBM 7090 digital computer to calculate radiation heating in propellant tanks, and radiation environment about nuclear rocket stag
Intensifying agricultural sustainability: an analysis of impacts and drivers in the development of ‘bright spots’
Food security / Farming systems / Sustainable agriculture / Productivity / Investment / Thailand / Palestine / Latin America / Africa
Integrated land and water management for food and environmental security
Water resource management / Food security / Environmental effects / Soil degradation / Water pollution / Watersheds / Urbanization / Public policy / Water quality / Ecosystems / Land resources / Water scarcity / Developing countries / Poverty / Households / Food supply / Economic aspects / Social aspects / Groundwater depletion / Salinity / Wetlands / Investment / Land use / Water use / Training needs assessment / Research priorities
Investigating the interstellar dust through the Fe K-edge
The chemical and physical properties of interstellar dust in the densest
regions of the Galaxy are still not well understood. X-rays provide a powerful
probe since they can penetrate gas and dust over a wide range of column
densities (up to ). The interaction (scattering and
absorption) with the medium imprints spectral signatures that reflect the
individual atoms which constitute the gas, molecule, or solid. In this work we
investigate the ability of high resolution X-ray spectroscopy to probe the
properties of cosmic grains containing iron. Although iron is heavily depleted
into interstellar dust, the nature of the Fe-bearing grains is still largely
uncertain. In our analysis we use iron K-edge synchrotron data of minerals
likely present in the ISM dust taken at the European Synchrotron Radiation
Facility. We explore the prospects of determining the chemical composition and
the size of astrophysical dust in the Galactic centre and in molecular clouds
with future X-ray missions. The energy resolution and the effective area of the
present X-ray telescopes are not sufficient to detect and study the Fe K-edge,
even for bright X-ray sources. From the analysis of the extinction cross
sections of our dust models implemented in the spectral fitting program SPEX,
the Fe K-edge is promising for investigating both the chemistry and the size
distribution of the interstellar dust. We find that the chemical composition
regulates the X-ray absorption fine structures in the post edge region, whereas
the scattering feature in the pre-edge is sensitive to the mean grain size.
Finally, we note that the Fe K-edge is insensitive to other dust properties,
such as the porosity and the geometry of the dust.Comment: 11 pages, 10 figures. Accepted for publication in Astronomy and
Astrophysic
“For Your Safety” Effects of Camera Surveillance on Safety Impressions, Situation Construal and Attributed Intent
Based on the assumption that monitoring technology in environmental settings impacts people’s state of mind and subsequent perceptions, the current study examines the influence of security camera’s on safety perceptions and citizen wellbeing. Participants watched a video of city streets that featured (versus not featured) security cameras. In the camera condition, their safety ratings were significantly higher than in the camera-less (control) condition. In addition, the camera condition caused more positive (“safe”) interpretations of an ambiguous situation than the control condition. Finally, results suggest that attributed intent underlying camera usage is a key construct to reckon with when considering camera placement. In discussing these findings, the conditions under which camera surveillance contributes to citizen wellbeing are elaborated on
Antibiotic use in children and the use of medicines by parents
Objective Antibiotic drugs are frequently used for viral infections in children. It is probable that health beliefs and parental concern have great influence on the use of drugs in children. This study, performed in The Netherlands, investigates whether the use of antibiotics in children is associated with the use of medicines by parents. Patients and methods In this observational cohort study, the authors selected 6731 children from the prescription database IADB.nl who did not receive antibiotics until their fifth birthday and 1479 children who received at least one antibiotic prescription every year. The authors then selected parents for each group of children (5790 mothers and 4250 fathers for the children who did not receive antibiotics and 1234 mothers and 1032 fathers for the children who regularly received antibiotics). The authors compared the use of antibiotics and other medicines between the two groups of parents. Results Parents of children who received antibiotics recurrently were found to use more antibiotics themselves compared with parents of children who did not receive antibiotics. Moreover, this group also showed a higher percentage of chronic medication use: (11.3 vs 6.2% (mothers) and 13.1% vs 9.5% (fathers)). Mothers more often use antacids, non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, anxiolytics, hypnotics, antidepressants, drugs for treatment of asthma and antihistamines. Fathers use more antacids, cardiovascular drugs, NSAIDs and asthma drugs. Conclusions The parents of children who receive antibiotic drugs regularly use more medicines compared with the parents of children who use no antibiotic drugs. Parents' medicine use may influence that of children and is a factor physicians and pharmacists should take into account
Use of antibiotics in rural and urban regions in the Netherlands:an observational drug utilization study
Background: Large livestock farms might increase the infection risk for the nearby human population because of an increased risk for disease outbreaks and because antibiotic-resistant bacteria are more likely to be present. We hypothesized that populations residing in rural areas have more contact with cattle compared with populations in urban areas, and will use more antibiotics or more frequently require a new course of antibiotics. Methods: Using data from the prescription database IADB.nl, we compared antibiotic use by patients living in rural areas to the use by patients living in urban areas. We also followed cohorts of antibiotic users and determined the patients who required a second antibiotic within 14 days after beginning the first antibiotic. Results: The yearly prevalence of antibiotic use was greater in rural areas compared with urban areas (2009: 23.6% versus 20.2% (p <0.001), especially in the younger age groups. More adult patients residing in rural areas required a second course of antibiotic treatment within 14 days after starting the first treatment. Conclusion: Individuals use more antibiotics, and adults more frequently require a second antibiotic prescription within 14 days, in rural areas compared with urban areas. Although the differences were small and the risks for the general rural population were not high, this difference should be investigated further
Antibiotic drug use of children in the Netherlands from 1999 till 2005
Objective Antibiotics are the most commonly prescribed drugs used by children. Excessive and irrational use of antibiotic drugs is a world-wide concern. We performed a drug utilization study describing the patterns of antibiotic use in children aged 0-19 years between 1999 and 2005 in the Netherlands. Methods We used IADB.nl, a database with pharmacy drug dispensing data covering a population of 500,000 people and investigated all prescriptions of oral antibiotic drugs (ATC J01) for children Results The total number of antibiotic prescriptions per 1000 children per year ranged from 282 in 2004 to 307 in 2001 and did not change between years during the study period in a clinically relevant way. The prevalence of receiving at least one prescription varied between 17.8% in 2004 and 19.3% in 2001. Amoxicillin was the most frequently prescribed drug (46.4% of all antibiotic prescriptions in 1999 and 43.2% in 2005). Between 1999 and 2005 there was a shift from the small-spectrum phenethicillin, a penicillin preparation [ratio 2005/1999 0.76; 95% confidence interval (CI) 0.72-0.81], to amoxicillin/clavulanic acid (ratio 2005/1999 1.70; 95% CI 1.61-1.79) and from the old macrolide erythromycin (ratio 2005/1999 0.35; 95% CI 0.32-0.39) to the new macrolide antibiotic azithromycin (ratio 2005/1999 1.78; 95% CI 1.65-1.92). Conclusion The use of antibiotic drugs in treating children in the Netherlands is comparable to that in other northern European countries. Broad-spectrum antibiotics were prescribed more frequently than recommended by the guidelines and increased during our study period. Initiatives to improve guideline-directed antibiotic prescribing are strongly recommended
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