Complete bilayer adsorption of C16TAB on the surface of mica using neutron reflection.

We present neutron reflection data from an alkylammonium surfactant (C16TAB) at the mica/water interface. The system is studied in situ in a noninvasive manner and indicates the formation of a complete adsorbed bilayer with little evidence of defects. A detailed analysis suggests that the data are not consistent with some other previously reported adsorbed structures, such as micelles or cylinders.BPThis is the accepted manuscript. The final version is available at http://pubs.acs.org/doi/full/10.1021/acs.jpcb.5b00397

Temporal variability of Delta C-14, delta C-13, and C/N in sinking particulate organic matter at a deep time series station in the northeast Pacific Ocean

A 6-year time series of Delta(14) C, delta(13) C, and C/N measurements in deep sinking particulate organic matter ( POM) is presented for an abyssal site, Station M in the northeast Pacific Ocean. The Delta(14)C values revealed that sinking POM at 3450 m depth ( 650 m above bottom) contained old carbon despite its presumed short transit time in the water column. The isotopic and chemical properties of the sinking POM varied with time and appear to be controlled by more than one major process. In 1993, 1994, and late 1996, isotopic signatures and C/N molar ratios indicate negligible or vertically homogeneous influence of resuspended particles from the bottom or particles laterally transported from the margin to the study site. However, during early 1995 and 1998, Delta(14)C values were lower than those during other periods and C/N values at three deep depths were not equal, indicating that the study site was influenced by resuspended sediments more severely than during other periods. During mid-1995 to mid-1996, delta(13)C values decreased abruptly while Delta(14)C values increased slightly, and C/N values were extremely high ( up to -80) at 50 and 600 m above bottom; these results suggest input of degraded, modern, terrestrial organic matter. The periods of anomalous isotopic signatures, as well as vertically heterogeneous C/N values [ Smith et al., 2001], were correlated with high discharge periods of California rivers with a time lag of 2 to 4 months. The correlation suggests that regional meteorological events are important in controlling the biogeochemical properties of particles at Station M by varying the intensity of resuspension and transport of organic matter from the continental margin

Orientation of a Diagnostic Ligand Bound to Macroscopically Aligned Amyloid-ß Fibrils Determined by Solid-state NMR

With amyloid diseases poised to become a major health burden in countries with aging populations, diagnostic molecules that aid the detection of amyloid in vitro and in vivo are of considerable clinical value. Understanding how such ligands recognize their amyloid targets would help to design diagnostics that target specific amyloid types associated with a particular disease, but methods to provide comprehensive information are underdeveloped. Here, solid-state NMR is used to determine the molecular orientation of the amyloid diagnostic 1-fluoro-2,5-bis[(E)-3-carboxy-4-hydroxystyryl]-benzene (FSB) when bound to fibrils of the Alzheimer’s amyloid-β polypeptide aligned on a planar substrate. The 19F NMR spectrum of the aligned complex reveals that FSB is oriented approximately parallel with the fibril long axis and bridges four hydrogen-bonded β-sheets. In addition to providing atomic details to aid the design of amyloid-specific diagnostics, this approach will also illuminate the molecular mechanisms of accessory molecules in amyloid disease

Multilayering of Calcium Aerosol-OT at the Mica/Water Interface Studied with Neutron Reflection: Formation of a Condensed Lamellar Phase at the CMC

Using specular neutron reflection, the adsorption of sodium and calcium salts of the surfactant bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT or AOT) has been studied at the mica/water interface at concentrations between 0.1 and 2 CMC. The pH dependence of the adsorption was also probed. No evidence of the adsorption of Na(AOT) was found even at the critical micelle concentration (CMC) while the calcium salt was found to adsorb significantly at concentrations of 0.5 CMC and above. This interesting and somewhat unexpected finding demonstrates that counterion identity may be used to tune the adsorption of anionic surfactants on anionic surfaces. At the CMC, three condensed bilayers of Ca(AOT)$_{2}$ were adsorbed at pH 7 and 9 and four bilayers adsorbed at pH 4. Multilayering at the CMC of Ca(AOT)$_{2}$ on the mica surface is an unusual feature of this surfactant/surface combination. Only single bilayer adsorption has been observed at other surfaces at the CMC. We suggest this arises from the high charge density of mica which must provide an excellent template for the surfactant.We thank BP for funding the work and our industrial colleagues, Isabella Stocker and Peter Salino, for their scientific contributions to the work (RG63491)

Exome sequencing in dementia with Lewy bodies.

Dementia with Lewy bodies (DLB) is the second most common form of degenerative dementia. Siblings of affected individuals are at greater risk of developing DLB, but little is known about the underlying genetic basis of the disease. We set out to determine whether mutations in known highly penetrant neurodegenerative disease genes are found in patients with DLB. Whole-exome sequencing was performed on 91 neuropathologically confirmed cases of DLB, supplemented by independent APOE genotyping. Genetic variants were classified using established criteria, and additional neuropathological examination was performed for putative mutation carriers. Likely pathogenic variants previously described as causing monogenic forms of neurodegenerative disease were found in 4.4% of patients with DLB. The APOE ɛ4 allele increased the risk of disease (P=0.0001), conferred a shorter disease duration (P=0.043) and earlier age of death (P=0.0015). In conclusion, although known pathogenic mutations in neurodegenerative disease genes are uncommon in DLB, known genetic risk factors are present in >60% of cases. APOE ɛ4 not only modifies disease risk, but also modulates the rate of disease progression. The reduced penetrance of reported pathogenic alleles explains the lack of a family history in most patients, and the presence of variants previously described as causing frontotemporal dementia suggests a mechanistic overlap between DLB and other neurodegenerative diseases.This study was funded by the NHS National Institute of Health Research Biomedical Research Unit for Lewy body dementia at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University. Tissue for this study was provided by Newcastle Brain Tissue Resource, which is funded in part by a grant from the UK Medical Research Council and by Brains for Dementia Research, a joint venture between Alzheimer’s Society and Alzheimer’s Research UK. MJK is a Wellcome Trust Clinical Research Training Fellow. PFC is a Wellcome Trust Senior Fellow in Clinical Science and National Institute for Health Research Senior Investigator. He receives funding from the Medical Research Council and the National Institute for Health Research Biomedical Research Centre for Ageing and Age-Related Disease award to the Newcastle upon Tyne Foundation Hospitals National Health Service Trust. The funding sources had no role in study design, data collection/analysis, the writing of the paper or the decision of when or where to publish it. The views expressed here are the views of the authors and not necessarily those of the NHS, NIHR or the Department of Health.This is the final published version. It first appeared at http://www.nature.com/tp/journal/v6/n2/full/tp2015220a.html

Evaluating the landscape of fear between apex predatory sharks and mobile sea turtles across a large dynamic seascape

The ‘‘landscape of fear’’ model has been proposed as a unifying concept in ecology, describing, in part, how animals behave and move about in their environment. The basic model predicts that as an animal’s landscape changes from low to high risk of predation, prey species will alter their behavior to risk avoidance. However, studies investigating and evaluating the landscape of fear model across large spatial scales (tens to hundreds of thousands of square kilometers) in dynamic, open, aquatic systems involving apex predators and highly mobile prey are lacking. To address this knowledge gap, we investigated predator–prey relationships between tiger sharks (Galeocerdo cuvier) and loggerhead turtles (Caretta caretta) in the North Atlantic Ocean. This included the use of satellite tracking to examine shark and turtle distributions as well as their surfacing behaviors under varying levels of home range overlap. Our findings revealed patterns that deviated from our a priori predictions based on the landscape of fear model. Specifically, turtles did not alter their surfacing behaviors to risk avoidance when overlap in shark–turtle core home range was high. However, in areas of high overlap with turtles, sharks exhibited modified surfacing behaviors that may enhance predation opportunity. We suggest that turtles may be an important factor in determining shark distribution, whereas for turtles, other life history trade-offs may play a larger role in defining their habitat use. We propose that these findings are a result of both biotic and physically driven factors that independently or synergistically affect predator–prey interactions in this system. These results have implications for evolutionary biology, community ecology, and wildlife conservation. Further, given the difficulty in studying highly migratory marine species, our approach and conclusions may be applied to the study of other predator–prey systems.Bald Head Island ConservancyBritish Chelonia GroupNatural Environmental Research CouncilWAVE Foundation/Newport Aquarium CincinnatiPADI project AWARESEATURTLE.ORGWhitener Foundation (NC); an Endangered Species Act Section 6 Cooperative Agreement with NOAA Fisheries and the Grays Reef National Marine Sanctuary (South Carolina and Georgia)Batchelor FoundationDinsey Conservation Fun

The Descriptive Epidemiology of the Diurnal Profile of Bouts and Breaks in Sedentary Time in English Older Adults

Background: High sedentary time is associated with adverse metabolic health outcomes and mortality in older adults. It has been suggested that breaking up sedentary time may be beneficial for metabolic health; however, population prevalence data are lacking on the patterns of sedentary behaviour which would identify opportunities for intervention. Methods: We used data of adults aged ≥ 60 years (n = 3705) from the population-based EPIC-Norfolk cohort, to characterize the patterns of total sedentary time, breaks in sedentary time and sedentary bouts across the day and assess their associations with participant characteristics, using multi-level regression. Sedentary time was measured objectively by a hip-mounted accelerometer (Actigraph™ GT1M) worn for 7 days during waking time. Results: More than 50% of every waking hour was spent sedentary, increasing to a peak of 83% in the evening. On average fewer breaks were accrued in the evenings compared with earlier in the day. Marginally more sedentary time was accrued on weekend days compared with weekdays (difference 7.4 min, 95% confidence interval 5.0–9.7). Large proportions of this sedentary time appear to be accrued in short bouts (bouts of < 10 min for 32% of the time). Older age, being male, being retired, not being in paid employment and having a higher body mass index were associated with greater sedentary time and fewer breaks. Conclusion: Sedentary time is common throughout the day but peaks in the evenings with fewer breaks and longer bouts. We identified a number of characteristics associated with sedentary time and additionally inversely associated with sedentary breaks, which should inform the development and targeting of strategies to reduce sedentary time among older adults.A.J.C., K.We., K.Wi., N.W., S.J.G. and S.B. were funded by Medical Research Council (MC_UU_12015/1, MC_UU_12015/3 and MC_UU_12015/4), and K.Wi. was funded by the British Heart Foundation (FS/12/58/29709). EPIC Norfolk is supported by programme grants from the Medical Research Council (UK G1000143 and MR/N003284/1) and Cancer Research UK (14136)

A conceptual framework and practical guide for assessing fitness-to-operate in the offshore oil and gas industry

The paper outlines a systemic approach to understanding and assessing safety capability in the offshore oil and gas industry. We present a conceptual framework and assessment guide for understanding fitness-to-operate (FTO) that builds a more comprehensive picture of safety capability for regulators and operators of offshore facilities. The FTO framework defines three enabling capitals that create safety capability: organizational capital, social capital, and human capital. For each type of capital we identify more specific dimensions based on current theories of safety, management, and organizational processes. The assessment guide matches specific characteristics to each element of the framework to support assessment of safety capability. The content and scope of the FTO framework enable a more comprehensive coverage of factors that influence short-term and long-term safety outcomes