Increased atmospheric SO₂ detected from changes in leaf physiognomy across the Triassic-Jurassic boundary interval of East Greenland

This is the final version of the article. Available from the publisher via the DOI in this record.The Triassic-Jurassic boundary (Tr-J; ∼201 Ma) is marked by a doubling in the concentration of atmospheric CO2, rising temperatures, and ecosystem instability. This appears to have been driven by a major perturbation in the global carbon cycle due to massive volcanism in the Central Atlantic Magmatic Province. It is hypothesized that this volcanism also likely delivered sulphur dioxide (SO2) to the atmosphere. The role that SO2 may have played in leading to ecosystem instability at the time has not received much attention. To date, little direct evidence has been presented from the fossil record capable of implicating SO2 as a cause of plant extinctions at this time. In order to address this, we performed a physiognomic leaf analysis on well-preserved fossil leaves, including Ginkgoales, bennettites, and conifers from nine plant beds that span the Tr-J boundary at Astartekløft, East Greenland. The physiognomic responses of fossil taxa were compared to the leaf size and shape variations observed in nearest living equivalent taxa exposed to simulated palaeoatmospheric treatments in controlled environment chambers. The modern taxa showed a statistically significant increase in leaf roundness when fumigated with SO2. A similar increase in leaf roundness was also observed in the Tr-J fossil taxa immediately prior to a sudden decrease in their relative abundances at Astartekløft. This research reveals that increases in atmospheric SO2 can likely be traced in the fossil record by analyzing physiognomic changes in fossil leaves. A pattern of relative abundance decline following increased leaf roundness for all six fossil taxa investigated supports the hypothesis that SO2 had a significant role in Tr-J plant extinctions. This finding highlights that the role of SO2 in plant biodiversity declines across other major geological boundaries coinciding with global scale volcanism should be further explored using leaf physiognomy.KLB acknowledges funding through a UCD Research Demonstratorship and Science Foundation Ireland (SFI 11/PI/1103). CMB acknowledges funding through a European Union Marie Curie Intra-European Fellowship FILE PIEF-GA-2009-253780 and a Marie Curie Career Integration Grant PyroMap PCIG10-GA- 2011-303610. MH acknowledges funding though PEA-IEF-2010-275626. JMC acknowledges funding through Science Foundation Ireland (SFI 11/PI/1103) and a European Research Council Starting Investigator Grant (ERC-2001-StG_279962). JMC, CMB, and MH acknowledge funding through a Marie Curie research grant (MEXT-CT-2006-042531)

Can atmospheric composition influence plant fossil preservation potential via changes in leaf mass per area? A new hypothesis based on simulated palaeoatmosphere experiments

Atmospheric composition, particularly levels of CO2 and O2, impacts all aspects of life but its role in relation to plant preservation in the fossil record is largely unconsidered. Plants, angiosperms in particular, have been widely shown to increase leaf mass per area (LMA) under high CO2 conditions and decrease LMA in low CO2 conditions. Leaf thickness has long been known to be a contributory factor in preservation potential in the plant fossil record, with thicker leaves considered to have a greater recalcitrance than thinner ones. Therefore, any change in leaf density/thickness, through changes to LMA, could lead to an increased or decreased preservation potential of fossil leaves at times of elevated or decreased CO2, respectively. . Additionally, the impact of changes to atmospheric O2 and to the atmospheric CO2:O2 ratio on LMA has not been previously considered in detail. This investigation examines the effect of simulated Mesozoic atmospheres, times of high CO2 and low O2, on LMA in a suite of gymnosperms that act as nearest living equivalents for common elements of Mesozoic floras. Exposure to high CO2 (~ 1,500 ppm) led to a statistically significant (p < 0.001) increase in LMA in four out of 6 species, and exposure to combined high CO2 and low O2 (~ 13%) induced a statistically significant (p < 0.001) increase in LMA in all six species. The investigation also examined the effects of atmospheric composition on %N, a key plant trait known to co-vary with LMA under modern atmospheric compositions that provides information on plant function and relates to photosynthetic efficiency. Most species showed decreased %N in treatments with increased LMA in agreement with modern ecological studies and supporting the co-varying nature of LMA and %N regardless of CO2:O2 ratio. These findings suggest that atmospheric composition has a pronounced impact on LMA. Based on these results, we propose the hypothesis that atmospheric composition is an important taphonomic filter of the fossil leaf record. Further research is now required to test the significance of atmospheric composition versus other well-known taphonomic filters

Severe vitamin D deficiency in 6 Canadian First Nation formula-fed infants

Background. Rickets was first described in the 17th century and vitamin D deficiency was recognized as the underlying cause in the early 1900s. Despite this long history, vitamin D deficiency remains a significant health concern. Currently, vitamin D supplementation is recommended in Canada for breast fed infants. There are no recommendations for supplementation in formula-fed infants. Objective. The objective of this report is to bring attention to the risk of severe vitamin D deficiency in high risk, formula fed infants. Design. A retrospective chart review was used to create this clinical case series. Results. Severe vitamin D deficiency was diagnosed in six formula-fed infants over a two-and-a-half year period. All six infants presented with seizures and they resided in First Nation communities located at latitude 54 in the province of Manitoba. While these infants had several risk factors for vitamin D deficiency, they were all receiving cow&#x0027;s milk based formula supplemented with 400 IU/L of vitamin D. Conclusion. This report suggests that current practice with regards to vitamin D supplementation may be inadequate, especially for high-risk infants. Health care professionals providing service to infants in a similar situation should be aware of this preventable condition. Hopefully this would contribute to its prevention, diagnosis and management

Impact of facial conformation on canine health: Brachycephalic Obstructive Airway Syndrome

The domestic dog may be the most morphologically diverse terrestrial mammalian species known to man; pedigree dogs are artificially selected for extreme aesthetics dictated by formal Breed Standards, and breed-related disorders linked to conformation are ubiquitous and diverse. Brachycephaly–foreshortening of the facial skeleton–is a discrete mutation that has been selected for in many popular dog breeds e.g. the Bulldog, Pug, and French Bulldog. A chronic, debilitating respiratory syndrome, whereby soft tissue blocks the airways, predominantly affects dogs with this conformation, and thus is labelled Brachycephalic Obstructive Airway Syndrome (BOAS). Despite the name of the syndrome, scientific evidence quantitatively linking brachycephaly with BOAS is lacking, but it could aid efforts to select for healthier conformations. Here we show, in (1) an exploratory study of 700 dogs of diverse breeds and conformations, and (2) a confirmatory study of 154 brachycephalic dogs, that BOAS risk increases sharply in a non-linear manner as relative muzzle length shortens. BOAS only occurred in dogs whose muzzles comprised less than half their cranial lengths. Thicker neck girths also increased BOAS risk in both populations: a risk factor for human sleep apnoea and not previously realised in dogs; and obesity was found to further increase BOAS risk. This study provides evidence that breeding for brachycephaly leads to an increased risk of BOAS in dogs, with risk increasing as the morphology becomes more exaggerated. As such, dog breeders and buyers should be aware of this risk when selecting dogs, and breeding organisations should actively discourage exaggeration of this high-risk conformation in breed standards and the show ring

The Surface Waters Acidification Project Palaeolimnology Programme: modern diatom/lake-water chemistry data-set

In 1983, when the Surface Waters Acidification Programme (SWAP) was announced, we were asked to design and implement a palaeolimnology sub-project involving scientists from Sweden, Norway, and the UK. Our aim was to reconstruct the acidification history of a range of sites in the three countries and to identify and evaluate the various alternative causes of lake acidification. The results of the project have been published recently (Battarbee et al. 1990, Renberg and Battarbee 1990). Although a comprehensive range of palaeolimnological methods and approaches was used in the study we recognised diatom analysis as central to the entire project. We consequently committed considerable effort to improving our diatom methodology and we were especially concerned with the pursuit of a common approach to diatom taxonomy and pH reconstruction. This effort centred on the creation and analysis of a large data-set of surface-sediment diatom assemblages and associated environmental variables from 170 sites representing the full range of lake types in the acid-sensitive and acidified regions of the three countries

Added Value Measures in Education Show Genetic as Well as Environmental Influence

Does achievement independent of ability or previous attainment provide a purer measure of the added value of school? In a study of 4000 pairs of 12-year-old twins in the UK, we measured achievement with year-long teacher assessments as well as tests. Raw achievement shows moderate heritability (about 50%) and modest shared environmental influences (25%). Unexpectedly, we show that for indices of the added value of school, genetic influences remain moderate (around 50%), and the shared (school) environment is less important (about 12%). The pervasiveness of genetic influence in how and how much children learn is compatible with an active view of learning in which children create their own educational experiences in part on the basis of their genetic propensities

Common Genetic Variants Explain the Majority of the Correlation Between Height and Intelligence : The Generation Scotland Study

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Multiple breath washout in bronchiectasis clinical trials: is it feasible?

BACKDGROUND: Evaluation of multiple breath washout (MBW) set-up including staff training, certification and central “over-reading” for data quality control is essential to determine the feasibility of MBW in future bronchiectasis studies. AIMS: To assess the outcomes of a MBW training, certification and central over-reading programme. METHODS: MBW training and certification was conducted in European sites collecting lung clearance index (LCI) data in the BronchUK Clinimetrics and/or i-BEST-1 studies. The blended training programme included the use of an eLearning tool and a 1-day face-to-face session. Sites submitted MBW data to trained central over-readers who determined validity and quality. RESULTS: Thirteen training days were delivered to 56 participants from 22 sites. Of 22 sites, 18 (82%) were MBW naïve. Participant knowledge and confidence increased significantly (p<0.001). By the end of the study recruitment, 15 of 22 sites (68%) had completed certification with a mean (range) time since training of 6.2 (3–14) months. In the BronchUK Clinimetrics study, 468 of 589 (79%) tests met the quality criteria following central over-reading, compared with 137 of 236 (58%) tests in the i-BEST-1 study. CONCLUSIONS: LCI is feasible in a bronchiectasis multicentre clinical trial setting; however, consideration of site experience in terms of training as well as assessment of skill drift and the need for re-training may be important to reduce time to certification and optimise data quality. Longer times to certification, a higher percentage of naïve sites and patients with worse lung function may have contributed to the lower success rate in the i-BEST-1 study

The correlation between reading and mathematics ability at age twelve has a substantial genetic component

Dissecting how genetic and environmental influences impact on learning is helpful for maximizing numeracy and literacy. Here we show, using twin and genome-wide analysis, that there is a substantial genetic component to children’s ability in reading and mathematics, and estimate that around one half of the observed correlation in these traits is due to shared genetic effects (so-called Generalist Genes). Thus, our results highlight the potential role of the learning environment in contributing to differences in a child’s cognitive abilities at age twelve

Genetics of callous-unemotional behavior in children

Callous-unemotional behavior (CU) is currently under consideration as a subtyping index for conduct disorder diagnosis. Twin studies routinely estimate the heritability of CU as greater than 50%. It is now possible to estimate genetic influence using DNA alone from samples of unrelated individuals, not relying on the assumptions of the twin method. Here we use this new DNA method (implemented in a software package called Genome-wide Complex Trait Analysis, GCTA) for the first time to estimate genetic influence on CU. We also report the first genome-wide association (GWA) study of CU as a quantitative trait. We compare these DNA results to those from twin analyses using the same measure and the same community sample of 2,930 children rated by their teachers at ages 7, 9 and 12. GCTA estimates of heritability were near zero, even though twin analysis of CU in this sample confirmed the high heritability of CU reported in the literature, and even though GCTA estimates of heritability were substantial for cognitive and anthropological traits in this sample. No significant associations were found in GWA analysis, which, like GCTA, only detects additive effects of common DNA variants. The phrase ‘missing heritability’ was coined to refer to the gap between variance associated with DNA variants identified in GWA studies versus twin study heritability. However, GCTA heritability, not twin study heritability, is the ceiling for GWA studies because both GCTA and GWA are limited to the overall additive effects of common DNA variants, whereas twin studies are not. This GCTA ceiling is very low for CU in our study, despite its high twin study heritability estimate. The gap between GCTA and twin study heritabilities will make it challenging to identify genes responsible for the heritability of CU