Panama Twilight

https://digitalcommons.library.umaine.edu/mmb-vp/4764/thumbnail.jp

Generalized Structured Component Analysis in candidate gene association studies: Applications and limitations [version 2; peer review: 3 approved]

Background: Generalized Structured Component Analysis (GSCA) is a component-based alternative to traditional covariance-based structural equation modelling. This method has previously been applied to test for association between candidate genes and clinical phenotypes, contrasting with traditional genetic association analyses that adopt univariate testing of many individual single nucleotide polymorphisms (SNPs) with correction for multiple testing. Methods: We first evaluate the ability of the GSCA method to replicate two previous findings from a genetics association study of developmental language disorders. We then present the results of a simulation study to test the validity of the GSCA method under more restrictive data conditions, using smaller sample sizes and larger numbers of SNPs than have previously been investigated. Finally, we compare GSCA performance against univariate association analysis conducted using PLINK v1.9. Results: Results from simulations show that power to detect effects depends not just on sample size, but also on the ratio of SNPs with effect to number of SNPs tested within a gene. Inclusion of many SNPs in a model dilutes true effects. Conclusions: We propose that GSCA is a useful method for replication studies, when candidate SNPs have been identified, but should not be used for exploratory analysis

Levels of Science Identity, Belonging and Experiences of Discrimination for Commencing Science Students at an Australian University

A key step in achieving gender equality in the science, technology, engineering, and mathematics (STEM) workforce is recruiting more women into undergraduate STEM degrees. Some disciplines, such as biology, have been more successful at this than others. Yet, gender issues at university still exist in these science disciplines, which may be deterring women from remaining in this career pathway. This case study at an Australian university explored known risk factors for attrition by surveying 215 first-year undergraduate science students. It also investigated how these factors differ for students in the ‘gender-balanced’ and ‘gender-unbalanced’ science fields. Findings showed that female students in both the ‘gender-balanced’ and ‘gender-unbalanced’ science fields begin university with low levels of belonging, and encounter experiences of discrimination early on. These findings highlight potential risk factors for attrition for incoming Australian science undergraduates, and some potential challenges tertiary educators need to be aware of within their first-year classrooms

Process-related patterns in dioxin emissions: a simplified assessment procedure applied to coke combustion in sinter plant

Analyses for dioxins present in the windlegs of sinter plant using coke breeze as fuel which were carried out originally to monitor the 17 targeted isomers have been re-examined in order to establish the variation in isomer profiles with location of the sampling point relative to the beginning of the sinter strand. The analysis has been carried out using peak height as a measure of isomer abundance to allow assessment of a large number of peaks reasonably rapidly. It is found that the isomer profiles of the tetra- to heptachlorodibenzofurans, which dominate sinter plant emissions in the exhaust gases from the majority of the bed are similar. However, analysis shows that whilst some isomers contribute a similar percentage of the isomer group at the beginning of the strand, there are more, which vary significantly from the mean. Ways in which this localised difference in isomer distribution could arise are discussed

Feasibility of a Supporting‐Salt‐Free Nonaqueous Redox Flow Battery Utilizing Ionic Active Materials

Nonaqueous redox flow batteries (NAqRFBs) are promising devices for grid‐scale energy storage, but high projected prices could limit commercial prospects. One route to reduced prices is to minimize or eliminate the expensive supporting salts typically employed in NAqRFBs. Herein, the feasibility of a flow cell operating in the absence of supporting salt by utilizing ionic active species is demonstrated. These ionic species have high conductivities in acetonitrile (12–19 mS cm−1) and cycle at 20 mA cm−2 with energy efficiencies (>75 %) comparable to those of state‐of‐the‐art NAqRFBs employing high concentrations of supporting salt. A chemistry‐agnostic techno‐economic analysis highlights the possible cost savings of minimizing salt content in a NAqRFB. This work offers the first demonstration of a NAqRFB operating without supporting salt. The associated design principles can guide the development of future active species and could make NAqRFBs competitive with their aqueous counterparts.Salt‐free cell: Decreasing the contribution of salt costs to the total electrolyte cost for nonaqueous redox flow batteries is essential for economic viability. A nonaqueous flow battery utilizing ionic active materials completely removes the need for a supporting salt. The cell cycling performance and area‐specific specific resistance are comparable to those of state‐of‐the‐art nonaqueous flow cells with high salt concentrations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137469/1/cssc201700028-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137469/2/cssc201700028.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137469/3/cssc201700028_am.pd

Childhood sleep disturbance and risk of psychotic experiences at 18 : UK birth cohort

BACKGROUND: Sleep disturbances are commonly reported in the psychosis prodrome, but rarely explored in relation to psychotic experiences. AIMS: To investigate the relationship between specific parasomnias (nightmares, night terrors and sleepwalking) in childhood and later adolescent psychotic experiences. METHOD: The sample comprised 4720 individuals from a UK birth cohort. Mothers reported on children's experience of regular nightmares at several time points between 2 and 9 years. Experience of nightmares, night terrors and sleepwalking was assessed using a semi-structured interview at age 12. Psychotic experiences were assessed at ages 12 and 18 using a semi-structured clinical interview. RESULTS: There was a significant association between the presence of nightmares at 12 and psychotic experiences at 18 when adjusted for possible confounders and psychotic experiences at 12 (OR = 1.62, 95% CI 1.19-2.20). The odds ratios were larger for those who reported persistent psychotic experiences. CONCLUSIONS: The presence of nightmares might be an early risk indicator for psychosis

Response of the Heavy-Fermion Superconductor CeCoIn5_5 to Pressure: Roles of Dimensionality and Proximity to a Quantum-Critical Point

We report measurements of the pressure-dependent superconducting transition temperature $T_c$ and electrical resistivity of the heavy-fermion compound CeCoIn$_5$. Pressure moves CeCoIn$_5$ away from its proximity to a quantum-critical point at atmospheric pressure. Experimental results are qualitatively consistent with theoretical predictions for strong-coupled, d-wave superconductivity in an anisotropic 3D superconductor.Comment: 9 pages, 5 figure

Risk, precaution and science: towards a more constructive policy debate. Talking point on the precautionary principle

Few issues in contemporary risk policy are as momentous or contentious as the precautionary principle. Since it first emerged in German environmental policy, it has been championed by environmentalists and consumer protection groups, and resisted by the industries they oppose (Raffensperger & Tickner, 1999). Various versions of the principle now proliferate across different national and international jurisdictions and policy areas (Fisher, 2002). From a guiding theme in European Commission (EC) environmental policy, it has become a general principle of EC law (CEC, 2000; Vos & Wendler, 2006). Its influence has extended from the regulation of environmental, technological and health risks to the wider governance of science, innovation and trade (O'Riordan & Cameron, 1994)