Early ontogeny of the lesser sandeel (Ammodytes marinus)

Background Lesser sandeel (Ammodytes marinus) is widely distributed in North Sea ecosystems. Sandeel acts as a critical trophic link between zooplankton and top predators (fish, mammals, sea birds). Because they live buried in the sand, sandeel may be directly affected by the rapid expansion of anthropogenic activities linked to their habitat on the sea bottom (e.g., hydrocarbon extraction, offshore renewable energy, and subsea mining). It is, therefore, important to understand the impact of cumulative environmental and anthropogenic stressors on this species. A detailed description of the ontogenetic timeline and developmental staging for this species is lacking limiting the possibilities for comparative developmental studies assessing, e.g., the impact of various environmental stressors. Results A detailed description of the morphological development of lesser sandeel and their developmental trajectory, obtained through visual observations and microscopic techniques, is presented. Methods for gamete stripping and intensive culture of the early life stages are also provided. Conclusion This work provides a basis for future research to understand the effect of cumulative environmental and anthropogenic stressors on development in the early life stages of lesser sandeel.publishedVersio

The Multiplexed Chemical Kinetic Photoionization Mass Spectrometer: A New Approach To Isomer-resolved Chemical Kinetics

We have developed a multiplexed time- and photon-energy?resolved photoionizationmass spectrometer for the study of the kinetics and isomeric product branching of gasphase, neutral chemical reactions. The instrument utilizes a side-sampled flow tubereactor, continuously tunable synchrotron radiation for photoionization, a multi-massdouble-focusing mass spectrometer with 100percent duty cycle, and a time- and positionsensitive detector for single ion counting. This approach enables multiplexed, universal detection of molecules with high sensitivity and selectivity. In addition to measurement of rate coefficients as a function of temperature and pressure, different structural isomers can be distinguished based on their photoionization efficiency curves, providing a more detailed probe of reaction mechanisms. The multiplexed 3-dimensional data structure (intensity as a function of molecular mass, reaction time, and photoionization energy) provides insights that might not be available in serial acquisition, as well as additional constraints on data interpretation

Pleistocene geochronologies for fluvial sedimentary sequences: an archaeologist's perspective

Current models of Pleistocene fluvial system development and dynamics are assessed from the perspective of European Lower and Middle Palaeolithic stone tool assemblages recovered from fluvial secondary contexts. Fluvial activity is reviewed both in terms of Milankovitch-scale processes across the glacial/interglacial cycles of the Middle and Late Pleistocene, and in response to sub-Milankovitch scale, high-frequency, low-magnitude climatic oscillations. The chronological magnitude of individual phases of fluvial activity is explored in terms of radiocarbon-dated sequences from the Late Glacial and early Holocene periods. It is apparent that fluvial activity is associated with periods of climatic transition, both high and low magnitude, although system response is far more universal in the case of the high magnitude glacial/ interglacial transitions. Current geochronological tools do not permit the development of high-resolution sequences for Middle Pleistocene sediments, while localised erosion and variable system responses do not facilitate direct comparison with the ice core records. However, Late Glacial and early Holocene sequences indicate that individual fluvial activity phases are relatively brief in duration (e.g. 10(2) and 10(3) yr). From an archaeological perspective, secondary context assemblages can only be interpreted in terms of a floating geochronology, although the data also permit a reinvestigation of the problems of artefact reworking. Copyright (c) 2005 John Wiley I Sons, Ltd

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Middle to late Pleistocene palaeoecological reconstructions and palaeotemperature estimates for cold/cool stage deposits at Whittlesey, eastern England

Fossiliferous beds in a complex sequence of late Middle to Late Pleistocene deposits at Whittlesey, eastern England, provided a rare opportunity for a multidisciplinary study of the palaeoecology of cool/cold stage deposits from different glacial stages. The fossiliferous sediments investigated form part of the River Nene 1st Terrace. Three of the four fossil assemblages investigated pre-date the last interglacial stage (Ipswichian/Eemian/marine oxygen isotope stage (MIS) 5e), whereas the other dates to part of the MIS 3 interstadial complex (Middle Devensian/Weichselian). Pollen, plant macrofossil, molluscan, coleopteran, ostracod, foraminifera and vertebrate data are available to a greater or lesser extent for each cool/cold stage assemblage, and they broadly present the same ecological picture for each one: a continuum from low-energy permanent to non-permanent aquatic habitats through marshland with associated waterside taxa, together with flood influxes of fluvial, riparian and ruderal taxa. Although each fossil assemblage records cool/cold climatic conditions, to a greater or lesser extent, these conditions are more apparent in the insect and ostracod faunas. In comparison with results published for the Last Glacial Maximum (LGM) stadial in The Netherlands, palaeotemperature estimates based on ranges of mutual agreement between independent coleopteran and ostracod methods for the three pre-Ipswichian/Eemian assemblages indicate minimum mean July air temperatures that are from +1° to +3 °C warmer, but January values that embrace the −8 °C estimate for the LGM. There is, however, a disparity between the coleopteran and ostracod palaeotemperature estimates for the Middle Devensian/Weichselian fossil assemblage, which are based on two different sample stratigraphic levels; the lower, coleopteran assemblage is indicative of very cool, continental climates, whereas the stratigraphically slightly higher ostracod assemblage suggests a climatic amelioration. Lack of numerical age-estimates prevents a robust stratigraphical interpretation, but the youngest pre-Ipswichian/Eemian fossil assemblage could date to the MIS 7–6 transition, at a time when cooling possibly preceded glacially driven sea-level fall. It is apparent from the rich coleopteran data that some continental cold-indicator taxa also appeared in pre-Ipswichian/Eemian cold stages and therefore assignment of continental cold-indicator taxa to particular Devensian/Weichselian intervals should be undertaken with care

Physical activity and colon cancer prevention: a meta-analysis

Although an inverse association between physical activity and risk of colon cancer is well established, a formal estimate of the magnitude of this risk reduction that includes recent studies is not available. This analysis examines the association by sex and study design, restricting analyses to studies where data for colon cancer alone were available. The authors reviewed published studies through June 2008 examining the association between physical activity and risk of colon cancer. Heterogeneity and publication bias were evaluated and random effects models used to estimate relative risks (RR). Differences by sex and study design were evaluated. A total of 52 studies were included. An inverse association between physical activity and colon cancer was found with an overall relative risk (RR) of 0.76 (95% confidence interval (CI): 0.72, 0.81). For men, the RR was 0.76 (95% CI: 0.71, 0.82); for women, this was little different, (RR=0.79, 95% CI: 0.71, 0.88). The findings from case–control studies were stronger (RR=0.69, 95% CI: 0.65, 0.74) than for cohort studies (RR=0.83, 95% CI: 0.78, 0.88). This study confirms previous studies reporting an inverse association between physical activity and colon cancer in both men and women, and provides quantitative estimates of the inverse association