An offset in TEX86 values between interbedded lithologies: Implications for sea-surface temperature reconstructions

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The TEX86 (TetraEther indeX of tetraethers consisting of 86 carbon atoms) sea-surface temperature (SST) proxy is based on the distribution of isoprenoid glycerol dialkyl glycerol tetraether (GDGT) membrane lipids of pelagic Thaumarchaeota that are preserved in marine sediments. It is a valuable tool for reconstructing past SSTs from sedimentary archives; however there are still major uncertainties as to the effects of variables other than temperature on the proxy. Here we present the first study of GDGT variability across early Cretaceous interbedded pelagic and shelf-sourced turbiditic sediments from two Deep Sea Drilling Project (DSDP) sites in the western North Atlantic. The results indicate that a small, but consistent, offset in TEX86 ratios, equivalent to ~ 1–2 °C of temperature difference, occurs between interbedded lithologies of a similar age. The offset can be attributed to spatial differences in sea-surface temperatures or thaumarchaeotal populations between the shelf and the open ocean, or to secondary diagenetic effects related to oxic degradation of the GDGTs. Of these, a difference in either thaumarchaeotal taxa or ecology between those living in the shelf and ocean areas seems most plausible. Regardless of the root cause of the offset, these findings highlight the necessity of careful sample selection prior to TEX86 analysis, to ensure robust interpretation of palaeotemperature trends.Thanks to Alexandra Nederbragt for her assistance with TEX86 analysis, and to Richard Pancost and Jennifer Biddle for their helpful discussions which greatly improved this manuscript. Thanks to Annette Bolton for her assistance with PCA in SPSS. We are grateful to the two anonymous reviewers for their thoughtful and detailed comments. Thanks to Alex Wülbers and Walter Hale at the Bremen Core Repository for their core-sampling assistance. This research was funded by a NERC studentship (K.L.) and a Royal Society University Research Fellowship (S.A.R.). Samples were provided by the Integrated Ocean Drilling Program (IODP)

Predicting free-space occupancy on novel artificial structures by an invasive intertidal barnacle using a removal experiment.

Artificial structures can create novel habitat in the marine environment that has been associated with the spread of invasive species. They are often located in areas of high disturbance and can vary significantly in the area of free space provided for settlement of marine organisms. Whilst correlation between the amount of free space available and recruitment success has been shown in populations of several marine benthic organisms, there has been relatively little focus on invasive species, a group with the potential to reproduce in vast numbers and colonise habitats rapidly. Invasion success following different scales of disturbance was examined in the invasive acorn barnacle, Austrominiusmodestus, on a unique art installation located in Liverpool Bay. Population growth and recruitment success were examined by comparing recruitment rates within disturbance clearings of 4 different sizes and by contrasting population development with early recruitment rates over a 10 week period. Disturbed areas were rapidly recolonised and monocultures of A. modestus formed within 6 weeks. The size of patch created during disturbance had no effect on the rate of recruitment, while a linear relationship between recruit density and patch size was observed. Density-dependent processes mediated initial high recruitment resulting in population stability after 8-10 weeks, but densities continued to greatly exceed those reported in natural habitats. Given that artificial structures are likely to continue to proliferate in light of climate change projections, free-space is likely to become more available more frequently in the future supporting the expansion of fast-colonising species

Widespread and synchronous change in deep-ocean circulation in the North and South Atlantic during the Late Cretaceous

Modern thermohaline circulation plays a role in latitudinal heat transport and in deep-ocean ventilation, yet ocean circulation may have functioned differently during past periods of extreme warmth, such as the Cretaceous. The Late Cretaceous (100–65 Ma) was an important period in the evolution of the North Atlantic Ocean, characterized by opening ocean gateways, long-term climatic cooling and the cessation of intermittent periods of anoxia (oceanic anoxic events, OAEs). However, how these phenomena relate to deep-water circulation is unclear. We use a proxy for deep-water mass composition (neodymium isotopes; εNd) to show that, at North Atlantic ODP Site 1276, deep waters shifted in the early Campanian (∼78–83 Ma) from εNd values of ∼−7 to values of ∼−9, consistent with a change in the style of deep-ocean circulation but >10 Myr after a change in bottom water oxygenation conditions. A similar, but more poorly dated, trend exists in εNd data from DSDP Site 386. The Campanian εNd transition observed in the North Atlantic records is also seen in the South Atlantic and proto-Indian Ocean, implying a widespread and synchronous change in deep-ocean circulation. Although a unique explanation does not exist for the change at present, we favor an interpretation that invokes Late Cretaceous climatic cooling as a driver for the formation of Southern Component Water, which flowed northward from the Southern Ocean and into the North Atlantic and proto-Indian Oceans

Reductions to main meal portion sizes reduce daily energy intake regardless of perceived normality of portion size: a 5 day cross-over laboratory experiment

Background Smaller portions may help to reduce energy intake. However, there may be a limit to the magnitude of the portion size reduction that can be made before consumers respond by increasing intake of other food immediately or at later meals. We tested the theoretical prediction that reductions to portion size would result in a significant reduction to daily energy intake when the resulting portion was visually perceived as ‘normal’ in size, but that a reduction resulting in a ‘smaller than normal’ portion size would cause immediate or later additional eating. Methods Over three 5-day periods, daily energy intake was measured in a controlled laboratory study using a randomized crossover design (N = 30). The served portion size of the main meal component of lunch and dinner was manipulated in three conditions: ‘large-normal’ (747 kcal), ‘small-normal’ (543 kcal), and ‘smaller than normal’ (339 kcal). Perceived ‘normality’ of portion sizes was determined by two pilot studies. Ad libitum daily energy intake from all meals and snacks was measured. Results Daily energy intake in the ‘large-normal’ condition was 2543 kcals. Daily energy intake was significantly lower in the ‘small-normal’ portion size condition (mean difference − 95 kcal/d, 95% CI [− 184, − 6], p = .04); and was also significantly lower in the ‘smaller than normal’ than the ‘small-normal’ condition (mean difference − 210 kcal/d, 95% CI [− 309, − 111], p < .001). Contrary to predictions, there was no evidence that the degree of additional food consumption observed was greater when portions were reduced past the point of appearing normal in size. Conclusions Reductions to the portion size of main-meal foods resulted in significant decreases in daily energy intake. Additional food consumption did not offset this effect, even when portions were reduced to the point that they were no longer perceived as being normal in size. Trial registration Prospectively registered protocol and analysis plan: https://osf.io/natws/; retrospectively registered: https://clinicaltrials.gov/ct2/show/NCT03811210

Visual perceptions of portion size normality and intended food consumption: A norm range model

Smaller portion sizes are associated with lower energy intake. We test a norm range model of the portion size effect on intended intake. A wide range of portion sizes were perceived as normal. Portions perceived as normal did not prompt intended compensatory eating. Portions perceived as smaller than normal prompted intended compensation

Angoff anchor statements: setting a flawed gold standard?

http://www.mededpublish.org/manuscripts/120

Personal and social norms for food portion sizes in lean and obese adults.

BACKGROUND: Portion size is an important component of dietary advice for weight control, but little is known about what portion sizes people consider 'normal'. This study determined the effect of body mass index (BMI), gender, dietary restraint and liking of the food on personal and social portion size norms for a range of foods and the degree of certainty over the norms. METHODS: Thirty lean (BMI 20-25 kg m(-)(2)) and 30 obese (BMI 30-35 kg m(-)(2)) men and women (aged 18-60 years) viewed 17 different portion sizes of 12 foods on a computer screen on two occasions a week apart. Participants responded 'more' or 'less' to each photograph reflecting personal portion size preference or perceived portion sizes of others. Personal and social norms for portion sizes of each food were determined using the method of constant stimuli giving a sigmoidal curve of the probability of answering 'less' over a range of portion sizes. The slope of the sigmoid at the norm gave a measure of certainty about the norm. Regression models were used to examine the effect of BMI, gender, dietary restraint and liking of the food on personal norms, social norms, the relationship between norms, and the slopes. RESULTS: Personal norms were significantly larger in the obese (P=0.026), men (P<0.001), those with lower dietary restraint (P<0.001), and those with higher liking for the food (P<0.001). Social norms were larger for women (P=0.012). The slopes at the norms were 30% shallower in the obese and in men (P<0.001). CONCLUSION: Larger personal norms for portion size among the obese, men, those with lower dietary restraint and those with higher liking for a food imply greater consumption, which may undermine weight control. Shallower slopes for norms in the obese and in men may imply less clearly defined habitual portion sizes.This study was supported by a program grant from the UK Medical Research Council (U105960389).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ijo.2015.4

Hand-portable HPLC with broadband spectral detection enables analysis of complex polycyclic aromatic hydrocarbon mixtures

Polycyclic aromatic hydrocarbons (PAHs) are considered priority hazardous substances due to their carcinogenic activity and risk to public health. Strict regulations are in place limiting their release into the environment, but enforcement is hampered by a lack of adequate field-testing procedure, instead relying on sending samples to centralised analytical facilities. Reliably monitoring levels of PAHs in the field is a challenge, owing to the lack of field-deployable analytical methods able to separate, identify, and quantify the complex mixtures in which PAHs are typically observed. Here, we report the development of a hand-portable system based on high-performance liquid chromatography incorporating a spectrally wide absorption detector, capable of fingerprinting PAHs based on their characteristic spectral absorption profiles: identifying 100% of the 24 PAHs tested, including full coverage of the United States Environmental Protection Agency priority pollutant list. We report unsupervised methods to exploit these new capabilities for feature detection and identification, robust enough to detect and classify co-eluting and hidden peaks. Identification is fully independent of their characteristic retention times, mitigating matrix effects which can preclude reliable determination of these analytes in challenging samples. We anticipate the platform to enable more sophisticated analytical measurements, supporting real-time decision making in the field

Service Delivery Review: a how to manual for local government

This 2nd edition of the Manual brings together advice, toolkits and templates to help councils regardless of size with assessing the services they provide for local communities. The Manual meets an increasing need from within the sector for practical guidance in undertaking service delivery reviews that are consistent with current local governance practice and processes