Small-Size Resonant Photoacoustic Cell of Inclined Geometry for Gas Detection

A photoacoustic cell intended for laser detection of trace gases is represented. The cell is adapted so as to enhance the gas-detection performance and, simultaneously, to reduce the cell size. The cell design provides an efficient cancellation of the window background (a parasite response due to absorption of laser beam in the cell windows) and acoustic isolation from the environment for an acoustic resonance of the cell. The useful photoacoustic response from a detected gas, window background and noise are analyzed in demonstration experiments as functions of the modulation frequency for a prototype cell with the internal volume ~ 0.5 cm^3. The minimal detectable absorption for the prototype is estimated to be ~ 1.2 10^{-8} cm^{-1} W Hz^{-1/2}.Comment: 11 pages, 5 figure

London calling?: Preferred emigration destinations among Icelandic youth

Post-print (lokagerð höfundar)Preferred emigration destinations among adolescents reflect images and stereotypes of other countries that continuously emerge in a multitude of local and global discourses and from concrete experiences with other countries. The affinities of Icelandic adolescents are split between the islands of the Northern Atlantic, continental Nordic countries, European core countries, and North American countries. If they had to leave Iceland, however, the largest proportion of Icelandic adolescents would want to move to the United States. Girls are more likely to choose the Nordic countries, in particular Denmark, while boys are more likely to choose English-speaking countries with a reputation for economic and military power such as the United States and England. Adolescents are more likely to prefer migrating to Europe rather than North America if they are proud of their Icelandic nationality, live in cohesive communities, have more educated parents, and feel closer to Europe. Adolescents who want to move abroad are in contrast most likely to have North American destinations in mind. Recent geopolitical changes may however shift the attention of Icelandic adolescents eastward towards the European continent.This article has benefited greatly from extensive discussions with Atli Hafthorsson, Brynhildur Thorarinsdottir, Kjartan Olafsson and Michael S. Gibbons, and from the pioneering scholarship of Professor Thorbjorn Broddason. The data collection was in part made possible by a grant from the University of Akureyri Research Fund.Peer Reviewe

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

Comparing production-biomass ratios of benthos and suprabenthos in macrofaunal marine crustaceans

Using available data from the literature, we compared the productionbiomass ratios (P/B) between the suprabenthic (= hyperbenthic) and the benthic (infaunaepifauna) species within the group of the macrofaunal marine crustaceans. This data set consists of 91 P/B estimates (26 for suprabenthos and 65 for infaunaepifauna) for 49 different species. Suprabenthic crustacean P/B was significantly higher than P/B of benthic crustacean (post-hoc Scheffé test; one-way analysis of covariance, ANCOVA; p < 103) and also of other (noncrustacean) benthic invertebrate (p < 104). Predictive multilinear regression (MLR) analysis for macrofaunal marine crustaceans showed P/B to depend significantly on mean annual temperature (T) and mean individual weight (W) (R2 = 0.367). Adding the variable swimming capacity increased goodness-of-fit to R2 = 0.528. The higher P/B of suprabenthic (= swimming) macrofauna in comparison with that of the benthic compartment seems to be related to the most apparent feature of the suprabenthos, its swimming capacity. The high P/Bs reported for suprabenthic species indicate how a nontrivial part of benthic production can be ignored if suprabenthos is not well sampled, therefore biasing the models of energy flow generated for trophic webs

School bullying by one or more ways : does it matter and how do students cope?

Students (n=452; ages 12–14 years) attending two South Australian metropolitan high schools completed the ‘Living & learning at school: Bullying at school’ survey in which they reported ways they were bullied and the strategies they would use to deal with bullying. Results showed that a small proportion of students were bullied in three or more ways, and that males and females differed in the coping strategies they would use if bullied. Significant differences were found between bullied and not bullied students in their use of ‘problem-focused’ in contrast to ‘emotion focused’, or ‘approach’ in contrast to ‘avoidance’ coping strategies, with bullied students more likely to use ‘avoidance’ strategies. Findings suggest that in terms of coping, it does matter whether or not a student is bullied in multiple ways