Scanning tunneling microscopy and molecular dynamics study of the Li2TiO3(001) surface

We have investigated the (001) surface structure of lithium titanate (Li2TiO3) using auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and scanning tunneling microscopy (STM). Li2TiO3 is a potential fusion reactor blanket material. After annealing at 1200 K, LEED demonstrated that the Li2TiO3(001) surface was well ordered and not reconstructed. STM imaging showed that terraces are separated in height by about 0.3 nm suggesting a single termination layer. Moreover, hexagonal patterns with a periodicity of ∼0.4 nm are observed. On the basis of molecular dynamics (MD) simulations, these are interpreted as a dynamic arrangement of Li atoms.

Options for support to agriculture and food security under climate change

Agriculture and food security are key sectors for intervention under climate change. Agricultural production is highly vulnerable even to 2C (low-end) predictions for global mean temperatures in 2100, with major implications for rural poverty and for both rural and urban food security. Agriculture also presents untapped opportunities for mitigation, given the large land area under crops and rangeland, and the additional mitigation potential of aquaculture. This paper presents a summary of current knowledge on options to support farmers, particularly smallholder farmers, in achieving food security through agriculture under climate change. Actions towards adaptation fall into two broad overlapping areas: (1) accelerated adaptation to progressive climate change over decadal time scales, for example integrated packages of technology, agronomy and policy options for farmers and food systems, and (2) better management of agricultural risks associated with increasing climate variability and extreme events, for example improved climate information services and safety nets. Maximization of agriculture’s mitigation potential will require investments in technological innovation and agricultural intensification linked to increased efficiency of inputs, and creation of incentives and monitoring systems that are inclusive of smallholder farmers. Food systems faced with climate change need urgent, broad-based action in spite of uncertainties.

Meteorology, air quality, and health in London: the ClearfLo project

The ClearfLo project provides integrated measurements of the meteorology, composition and particulate loading of London's urban atmosphere to improve predictive capability for air quality. Air quality and heat are strong health drivers and their accurate assessment and forecast are important in densely populated urban areas. However, the sources and processes leading to high concentrations of main pollutants such as ozone, nitrogen dioxide, and fine and coarse particulate matter in complex urban areas are not fully understood, limiting our ability to forecast air quality accurately. This paper introduces the ClearfLo project's interdisciplinary approach to investigate the processes leading to poor air quality and elevated temperatures. Within ClearfLo (www.clearflo.ac.uk), a large multi-institutional project funded by the UK Natural Environment Research Council (NERC), integrated measurements of meteorology, gaseous and particulate composition/loading within London's atmosphere were undertaken to understand the processes underlying poor air quality. Long-term measurement infrastructure installed at multiple levels (street and elevated), and at urban background, kerbside and rural locations were complemented with high-resolution numerical atmospheric simulations . Combining these (measurement/modeling) enhances understanding of seasonal variations in meteorology and composition together with the controlling processes. Two intensive observation periods (winter 2012 and summer Olympics 2012) focus upon the vertical structure and evolution of the urban boundary layer, chemical controls on nitrogen dioxide and ozone production, in particular the role of volatile organic compounds, and processes controlling the evolution, size, distribution and composition of particulate matter. The paper shows that mixing heights are deeper over London than in the rural surroundings and the seasonality of the urban boundary layer evolution controls when concentrations peak. The composition also reflects the seasonality of sources such as domestic burning and biogenic emissions.

The XWS open access catalogue of extreme European windstorms from 1979 to 2012

The XWS (eXtreme WindStorms) catalogue consists of storm tracks and model-generated maximum 3 s wind-gust footprints for 50 of the most extreme winter windstorms to hit Europe in the period 1979–2012. The catalogue is intended to be a valuable resource for both academia and industries such as (re)insurance, for example allowing users to characterise extreme European storms, and validate climate and catastrophe models. Several storm severity indices were investigated to find which could best represent a list of known high-loss (severe) storms. The best-performing index was Sft, which is a combination of storm area calculated from the storm footprint and maximum 925 hPa wind speed from the storm track. All the listed severe storms are included in the catalogue, and the remaining ones were selected using Sft. A comparison of the model footprint to station observations revealed that storms were generally well represented, although for some storms the highest gusts were underestimated. Possible reasons for this underestimation include the model failing to simulate strong enough pressure gradients and not representing convective gusts. A new recalibration method was developed to estimate the true distribution of gusts at each grid point and correct for this underestimation. The recalibration model allows for storm-to-storm variation which is essential given that different storms have different degrees of model bias. The catalogue is available at www.europeanwindstorms.org.

Quantitative structure of an acetate dye molecule analogue at the TiO2- acetic acid interface

The positions of atoms in and around acetate molecules at the rutile TiO2(110) interface with 0.1 M acetic acid have been determined with a precision of ±0.05 Å. Acetate is used as a surrogate for the carboxylate groups typically employed to anchor monocarboxylate dye molecules to TiO2 in dye-sensitised solar cells (DSSC). Structural analysis reveals small domains of ordered (2 x 1) acetate molecules, with substrate atoms closer to their bulk terminated positions compared to the clean UHV surface. Acetate is found in a bidentate bridge position, binding through both oxygen atoms to two five-fold titanium atoms such that the molecular plane is along the [001] azimuth. Density functional theory calculations provide adsorption geometries in excellent agreement with experiment. The availability of these structural data will improve the accuracy of charge transport models for DSSC.

BAECC: a field campaign to elucidate the impact of Biogenic Aerosols on Clouds and Climate

Observations obtained during an 8-month deployment of AMF2 in a boreal environment in Hyytiälä, Finland, and the 20-year comprehensive in-situ data from SMEAR-II station enable the characterization of biogenic aerosol, clouds and precipitation, and their interactions. During “Biogenic Aerosols - Effects on Clouds and Climate (BAECC)”, the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Program deployed the ARM 2nd Mobile Facility (AMF2) to Hyytiälä, Finland, for an 8-month intensive measurement campaign from February to September 2014. The primary research goal is to understand the role of biogenic aerosols in cloud formation. Hyytiälä is host to SMEAR-II (Station for Measuring Forest Ecosystem-Atmosphere Relations), one of the world’s most comprehensive surface in-situ observation sites in a boreal forest environment. The station has been measuring atmospheric aerosols, biogenic emissions and an extensive suite of parameters relevant to atmosphere-biosphere interactions continuously since 1996. Combining vertical profiles from AMF2 with surface-based in-situ SMEAR-II observations allow the processes at the surface to be directly related to processes occurring throughout the entire tropospheric column. Together with the inclusion of extensive surface precipitation measurements, and intensive observation periods involving aircraft flights and novel radiosonde launches, the complementary observations provide a unique opportunity for investigating aerosol-cloud interactions, and cloud-to-precipitation processes, in a boreal environment. The BAECC dataset provides opportunities for evaluating and improving models of aerosol sources and transport, cloud microphysical processes, and boundary-layer structures. In addition, numerical models are being used to bridge the gap between surface-based and tropospheric observations.

The CATH Hierarchy Revisited-Structural Divergence in Domain Superfamilies and the Continuity of Fold Space

This paper explores the structural continuum in CATH and the extent to which superfamilies adopt distinct folds. Although most superfamilies are structurally conserved, in some of the most highly populated superfamilies (4% of all superfamilies) there is considerable structural divergence. While relatives share a similar fold in the evolutionary conserved core, diverse elaborations to this core can result in significant differences in the global structures. Applying similar protocols to examine the extent to which structural overlaps occur between different fold groups, it appears this effect is confined to just a few architectures and is largely due to small, recurring super-secondary motifs (e.g., alpha beta-motifs, alpha-hairpins). Although 24% of superfamilies overlap with superfamilies having different folds, only 14% of nonredundant structures in CATH are involved in overlaps. Nevertheless, the existence of these overlaps suggests that, in some regions of structure space, the fold universe should be seen as more continuous.

The CATH classification revisited-architectures reviewed and new ways to characterize structural divergence in superfamilies

The latest version of CATH (class, architecture, topology, homology) (version 3.2), released in July 2008 (http://www.cathdb.info), contains 1 14215 domains, 2178 Homologous superfamilies and 1110 fold groups. We have assigned 20 330 new domains, 87 new homologous superfamilies and 26 new folds since CATH release version 3.1. A total of 28 064 new domains have been assigned since our NAR 2007 database publication (CATH version 3.0). The CATH website has been completely redesigned and includes more comprehensive documentation. We have revisited the CATH architecture level as part of the development of a `Protein Chart` and present information on the population of each architecture. The CATHEDRAL structure comparison algorithm has been improved and used to characterize structural diversity in CATH superfamilies and structural overlaps between superfamilies. Although the majority of superfamilies in CATH are not structurally diverse and do not overlap significantly with other superfamilies, similar to 4% of superfamilies are very diverse and these are the superfamilies that are most highly populated in both the PDB and in the genomes. Information on the degree of structural diversity in each superfamily and structural overlaps between superfamilies can now be downloaded from the CATH website.

Bourdieu, subcultural capital and risky girlhood

It is a contention of the culturalist strand of underclass theory that the growth of the underclass is not a function of social and economic change, but of features intrinsic to underclass culture. Children born into disadvantaged communities, it is argued, are socialized into the ‘deviant’ culture of their families, families typically headed by single mothers. According to the underclass thesis, daughters of such families will face a heightened risk of leaving school early and teenage pregnancy. An unanticipated correlation between claims of the underclass thesis and the cohort of mothers and daughters with whom we are working on a current project has led us to ask, ‘how do we acknowledge the culture of disadvantaged communities and their generational synergies, whilst avoiding the pernicious implications of the underclass thesis?’ To answer this question, this article assesses
the merits of bringing Bourdieu’s ideas on cultural capital together with Sarah Thornton’s concept of subcultural capital. The article concludes with two examples of how we might draw on these ideas as a way of exploring the means by which girls in difficult economic circumstances understand and pursue their school lives.

Area variation in recreational cycling in Melbourne : a compositional or contextual effect?

Objective: To examine whether compositional and/or contextual area characteristics are associated with area socioeconomic inequalities and between-area differences in recreational cycling.

Setting: The city of Melbourne, Australia.

Participants: 2349 men and women residing in 50 areas (58.7% response rate).

Main outcome measure: Cycling for recreational purposes (at least once a month vs never).

Design: In a cross-sectional survey participants reported their frequency of recreational cycling. Objective area characteristics were collected for their residential area by environmental audits or calculated with Geographic Information Systems software. Multilevel logistic regression models were performed to examine associations between recreational cycling, area socioeconomic level, compositional characteristics (age, sex, education, occupation) and area characteristics (design, safety, destinations or aesthetics).

Results: After adjustment for compositional characteristics, residents of deprived areas were less likely to cycle for recreation (OR 0.66; 95% CI 0.43 to 1.00), and significant between-area differences in recreational cycling were found (median odds ratio 1.48 (95% credibility interval 1.24 to 1.78). Aesthetic characteristics tended to be worse in deprived areas and were the only group of area characteristics that explained some of the area deprivation differences. Safety characteristics explained the largest proportion of between-area variation in recreational cycling.

Conclusion: Creating supportive environments with respect to safety and aesthetic area characteristics may decrease between-area differences and area deprivation inequalities in recreational cycling, respectively.

Rock strength : a control of shore platform elevation

This study determined whether a previous laboratory finding relating platform elevation to rock strength could be verified when tested in the field. Testing took place along the Otway coast in southeastern Australia. Fourteen platforms were profiled using a total station while rock strength tests were performed with a type L Schmidt hammer. Results established that higher mean platform elevation correlated with increased rock strength (r = 0.661, p < 0.05). This confirmed that a relation exists between elevation and rock strength when tested in the field. This finding has implications for the interpretation of shore platforms and marine terrace elevations in relation to sea level.