Studying the Kinematics of Faint Stellar Populations with the Planetary Nebula Spectrograph

Galaxies are faint enough when one observes just their light distributions, but in studying their full dynamical structure the stars are spread over the six dimensions of phase space rather than just the three spatial dimensions, making their densities very low indeed. This low signal is unfortunate, as stellar dynamics hold important clues to these systems' life histories, and the issue is compounded by the fact that the most interesting information comes from the faintest outer parts of galaxies, where dynamical timescales (and hence memories of past history) are longest. To extract this information, we have constructed a special-purpose instrument, the Planetary Nebula Spectrograph, which observes planetary nebulae as kinematic tracers of the stellar population, and allows one to study the stellar dynamics of galaxies down to extremely low surface brightnesses. Here, we present results from this instrument that illustrate how it can uncover the nature of low surface-brightness features such as thick disks by studying their kinematics, and trace faint kinematic populations that are photometrically undetectable.Comment: 4 pages, 2 figures. To be published in "Hunting for the Dark: The Hidden Side of Galaxy Formation", eds. V.P. Debattista & C.C. Popescu, AIP Conf. Se

Change in active travel and changes in recreational and total physical activity in adults: longitudinal findings from the iConnect study.

BACKGROUND: To better understand the health benefits of promoting active travel, it is important to understand the relationship between a change in active travel and changes in recreational and total physical activity. METHODS: These analyses, carried out in April 2012, use longitudinal data from 1628 adult respondents (mean age 54 years; 47% male) in the UK-based iConnect study. Travel and recreational physical activity were measured using detailed seven-day recall instruments. Adjusted linear regression models were fitted with change in active travel defined as 'decreased' (15 min/week) as the primary exposure variable and changes in (a) recreational and (b) total physical activity (min/week) as the primary outcome variables. RESULTS: Active travel increased in 32% (n=529), was maintained in 33% (n=534) and decreased in 35% (n=565) of respondents. Recreational physical activity decreased in all groups but this decrease was not greater in those whose active travel increased. Conversely, changes in active travel were associated with commensurate changes in total physical activity. Compared with those whose active travel remained unchanged, total physical activity decreased by 176.9 min/week in those whose active travel had decreased (adjusted regression coefficient -154.9, 95% CI -195.3 to -114.5) and was 112.2 min/week greater among those whose active travel had increased (adjusted regression coefficient 135.1, 95% CI 94.3 to 175.9). CONCLUSION: An increase in active travel was associated with a commensurate increase in total physical activity and not a decrease in recreational physical activity

a bourdieusian analysis of under-age access to tobacco among adolescents from seven European cities

Funding Information: The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was undertaken as part of the SILNE-R project, led by Prof Anton Kunst (University of Amsterdam) and funded by the European Commission Horizon2020 program, call PHC6-2014, under Grant Agreement no. 635056. Publisher Copyright: © The Author(s) 2021.Despite efforts to reduce adolescent smoking via minimum age-of-sale legislation, many young people continue to access tobacco through a mix of social and commercial sources. Little is known about the roles of habitus, capital, and social topographies in shaping under-age access to tobacco. This article draws on Bourdieu’s theory of practice and data generated from 56 focus groups with 14- to 19-year-olds across seven European cities to answer the question “via what sources and by what means do adolescents obtain tobacco?” We find that adolescents use a range of personal capitals (social, cultural, and economic) to access tobacco, with the specific constitution and deployment of these capitals varying according to the regularities of different fields. Since adolescents access tobacco via culturally embedded practices, attempts to curtail this access are more likely to be effective if they are multi-pronged, culturally informed, and attuned to the lived experiences of adolescent smokers.publishersversionpublishe

Improving the reliability of model-based decision-making estimates in the two-stage decision task with reaction-times and drift-diffusion modeling

A well-established notion in cognitive neuroscience proposes that multiple brain systems contribute to choice behaviour. These include: (1) a model-free system that uses values cached from the outcome history of alternative actions, and (2) a model-based system that considers action outcomes and the transition structure of the environment. The widespread use of this distinction, across a range of applications, renders it important to index their distinct influences with high reliability. Here we consider the two-stage task, widely considered as a gold standard measure for the contribution of model-based and model-free systems to human choice. We tested the internal/temporal stability of measures from this task, including those estimated via an established computational model, as well as an extended model using drift-diffusion. Drift-diffusion modeling suggested that both choice in the first stage, and RTs in the second stage, are directly affected by a model-based/free trade-off parameter. Both parameter recovery and the stability of model-based estimates were poor but improved substantially when both choice and RT were used (compared to choice only), and when more trials (than conventionally used in research practice) were included in our analysis. The findings have implications for interpretation of past and future studies based on the use of the two-stage task, as well as for characterising the contribution of model-based processes to choice behaviour

Socio-scientific Inquiry-Based Learning: Taking off from STEPWISE

In the European Union educational policy-making bodies are encouraging projects of inquiry-based learning to stimulate interest of young people in science and broaden the science and technological base. In this article I discuss how a project which incorporates socio-political questions as the object of its inquiry can critically address issues of consumerism and unequal distribution which affect contemporary neoliberal economies. Components of this model of inquiry draw on substantive scientific knowledge incorporating Responsible Research and Innovation (RRI), Critical Citizenship Education, Socio-Scientific Issues as well as Inquiry hence the acronym, SSIBL (Socio-Scientific Inquiry Based Learning). Social values at the heart of this project are science inquiry as for and with people recognising that we live in a diverse world where technological change should be underpinned by social justice and political responsibility. We describe how authentic activities, those which stem from students’ concerns, can be derived from these values to lead to non-trivial action which takes into account social, political and cultural constraints and uncertainties. Inquiries reflect issues which have personal, social and global relevance. A sensitive assessment strategy is developed which incorporates knowledge about the issue, skills of organising, values that reflect the underlying principles of compassionate justice and dispositions of inclusivity and criticality

Common DNA markers can account for more than half of the genetic influence on cognitive abilities

For nearly a century, twin and adoption studies have yielded substantial estimates of heritability for cognitive abilities, although it has proved difficult for genomewide-association studies to identify the genetic variants that account for this heritability (i.e., the missing-heritability problem). However, a new approach, genomewide complex-trait analysis (GCTA), forgoes the identification of individual variants to estimate the total heritability captured by common DNA markers on genotyping arrays. In the same sample of 3,154 pairs of 12-year-old twins, we directly compared twin-study heritability estimates for cognitive abilities (language, verbal, nonverbal, and general) with GCTA estimates captured by 1.7 million DNA markers. We found that DNA markers tagged by the array accounted for .66 of the estimated heritability, reaffirming that cognitive abilities are heritable. Larger sample sizes alone will be sufficient to identify many of the genetic variants that influence cognitive abilities

Germline genetic variation in prostate susceptibility does not predict outcomes in the chemoprevention trials PCPT and SELECT

Background The development of prostate cancer can be influenced by genetic and environmental factors. Numerous germline SNPs influence prostate cancer susceptibility. The functional pathways in which these SNPs increase prostate cancer susceptibility are unknown. Finasteride is currently not being used routinely as a chemoprevention agent but the long term outcomes of the PCPT trial are awaited. The outcomes of the SELECT trial have not recommended the use of chemoprevention in preventing prostate cancer. This study investigated whether germline risk SNPs could be used to predict outcomes in the PCPT and SELECT trial. Methods Genotyping was performed in European men entered into the PCPT trial (n = 2434) and SELECT (n = 4885). Next generation genotyping was performed using Affymetrix® Eureka™ Genotyping protocols. Logistic regression models were used to test the association of risk scores and the outcomes in the PCPT and SELECT trials. Results Of the 100 SNPs, 98 designed successfully and genotyping was validated for samples genotyped on other platforms. A number of SNPs predicted for aggressive disease in both trials. Men with a higher polygenic score are more likely to develop prostate cancer in both trials, but the score did not predict for other outcomes in the trial. Conclusion Men with a higher polygenic risk score are more likely to develop prostate cancer. There were no interactions of these germline risk SNPs and the chemoprevention agents in the SELECT and PCPT trials

In silico karyotyping of chromosomally polymorphic malaria mosquitoes in the Anopheles gambiae complex

Chromosomal inversion polymorphisms play an important role in adaptation to environmental heterogeneities. For mosquito species in the Anopheles gambiae complex that are significant vectors of human malaria, paracentric inversion polymorphisms are abundant and are associated with ecologically and epidemiologically important phenotypes. Improved understanding of these traits relies on determining mosquito karyotype, which currently depends upon laborious cytogenetic methods whose application is limited both by the requirement for specialized expertise and for properly preserved adult females at specific gonotrophic stages. To overcome this limitation, we developed sets of tag single nucleotide polymorphisms (SNPs) inside inversions whose biallelic genotype is strongly correlated with inversion genotype. We leveraged 1,347 fully sequenced An. gambiae and Anopheles coluzzii genomes in the Ag1000G database of natural variation. Beginning with principal components analysis (PCA) of population samples, applied to windows of the genome containing individual chromosomal rearrangements, we classified samples into three inversion genotypes, distinguishing homozygous inverted and homozygous uninverted groups by inclusion of the small subset of specimens in Ag1000G that are associated with cytogenetic metadata. We then assessed the correlation between candidate tag SNP genotypes and PCA-based inversion genotypes in our training sets, selecting those candidates with >80% agreement. Our initial tests both in held-back validation samples from Ag1000G and in data independent of Ag1000G suggest that when used for in silico inversion genotyping of sequenced mosquitoes, these tags perform better than traditional cytogenetics, even for specimens where only a small subset of the tag SNPs can be successfully ascertained