Imaging Water Dissociation on TiO₂(110)

Scanning tunneling microscopy has been used to identify the adsorption site of H₂O on TiO₂(110)-(1 x 1) at 150 K, and to monitor the site of the dissociation products at 290 K. Water adsorbs onto the rows of fivefold coordinated Ti atoms at 150 K, dissociating by 290 K to form bridging but not terminal hydroxyls. This points to the involvement of bridging O vacancies in the dissociation pathway

A serious game to explore human foraging in a 3D environment

Traditional search tasks have taught us much about vision and attention. Recently, several groups have begun to use multiple-target search to explore more complex and temporally extended "foraging" behaviour. Many of these new foraging tasks, however, maintain the simplified 2D displays and response demands associated with traditional, single-target visual search. In this respect, they may fail to capture important aspects of real-world search or foraging behaviour. In the current paper, we present a serious game for mobile platforms, developed in Unity3D, in which human participants play the role of an animal foraging for food in a simulated 3D environment. Game settings can be adjusted, so that, for example, custom target and distractor items can be uploaded, and task parameters, such as the number of target categories or target/distractor ratio are all easy to modify. We are also making the Unity3D project available, so that further modifications can also be made. We demonstrate how the app can be used to address specific research questions by conducting two human foraging experiments. Our results indicate that in this 3D environment, a standard feature/conjunction manipulation does not lead to a reduction in foraging runs, as it is known to do in simple, 2D foraging tasks

Carboxylate Adsorption on Rutile TiO2(100): Role of Coulomb Repulsion, Relaxation, and Steric Hindrance

Understanding the adsorption and photoactivity of acetic acid and trimethyl acetic acid on TiO2 surfaces is important for improving the performance of photocatalysts and dye-sensitized solar cells. Here we present a structural study of adsorption on rutile TiO2(100)-1 × 1 and -1 × 3 using Scanning Tunnelling Microscopy and Density Functional Theory calculations. Exposure of both terminations to acetic acid gives rise to a ×2 periodicity in the [001] direction (i.e., along Ti rows), with a majority ordered c(2 × 2) phase in the case of the 1 × 1 termination. The DFT calculations suggest that the preference of c(2 × 2) over the 2 × 1 periodicity found for TiO2(110)-1 × 1 can be attributed to an increase in interadsorbate Coulomb repulsion. Exposure of TiO2(100)-1 × 1 and -1 × 3 to trimethyl acetic acid gives rise to largely disordered structures due to steric effects, with quasi-order occurring in small areas and near step edges where these effects are reduced

A critical appraisal of McKinnon's complementarity hypothesis: Does the real rate of return on money matter for investment in developing countries?

This is the post-print version of the final paper published in World Development. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2009 Elsevier B.V.McKinnon’s [McKinnon, R. I. (1973). Moneyandcapitalineconomicdevelopment. Washington, DC: The Brookings Institution] complementarity hypothesis predicts that money and investment are complementary due to self-financed investment, so that a real deposit rate is the key determinant of capital formation for developing economies. This paper critically appraises this contention by conducting a vigorous empirical approach using panel data for 107 developing countries. The long-run and dynamic estimation results based on McKinnon’s theoretical model are supportive of the hypothesis. However, when the investment model is conditioned by factors such as financial development, different income levels across developing countries, external inflows, public finance, and trade constraints, the credibility of the hypothesis is undermined

Shipborne eddy covariance observations of methane fluxes constrain Arctic sea emissions

We demonstrate direct eddy covariance (EC) observations of methane (CH4) fluxes between the sea and atmosphere from an icebreaker in the eastern Arctic Ocean. EC-derived CH4 emissions averaged 4.58, 1.74, and 0.14 mg m−2 day−1 in the Laptev, East Siberian, and Chukchi seas, respectively, corresponding to annual sea-wide fluxes of 0.83, 0.62, and 0.03 Tg year−1. These EC results answer concerns that previous diffusive emission estimates, which excluded bubbling, may underestimate total emissions. We assert that bubbling dominates sea-air CH4 fluxes in only small constrained areas: A ~100-m2 area of the East Siberian Sea showed sea-air CH4 fluxes exceeding 600 mg m−2 day−1; in a similarly sized area of the Laptev Sea, peak CH4 fluxes were ~170 mg m−2 day−1. Calculating additional emissions below the noise level of our EC system suggests total ESAS CH4 emissions of 3.02 Tg year−1, closely matching an earlier diffusive emission estimate of 2.9 Tg year−1

Direct determination of the air-sea CO₂ gas transfer velocity in Arctic sea-ice regions

The Arctic Ocean is an important sink for atmospheric CO₂. The impact of decreasing sea-ice extent and expanding marginal ice zones on Arctic air-sea CO₂ exchange depends on the rate of gas transfer in the presence of sea ice. Sea ice acts to limit air-sea gas exchange by reducing contact between air and water, but is also hypothesised to enhance gas transfer rates across surrounding open water surfaces through physical processes such as increased surface-ocean turbulence from ice-water shear and ice-edge form drag. Here we present the first direct determination of the CO₂ air-sea gas transfer velocity in a wide range of Arctic sea-ice conditions. We show that the gas transfer velocity increases near-linearly with decreasing sea-ice concentration. We also show that previous modeling approaches overestimate gas transfer rates in sea-ice regions

Impaired perception of facial motion in autism spectrum disorder

Copyright: © 2014 O’Brien et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Facial motion is a special type of biological motion that transmits cues for socio-emotional communication and enables the discrimination of properties such as gender and identity. We used animated average faces to examine the ability of adults with autism spectrum disorders (ASD) to perceive facial motion. Participants completed increasingly difficult tasks involving the discrimination of (1) sequences of facial motion, (2) the identity of individuals based on their facial motion and (3) the gender of individuals. Stimuli were presented in both upright and upside-down orientations to test for the difference in inversion effects often found when comparing ASD with controls in face perception. The ASD group’s performance was impaired relative to the control group in all three tasks and unlike the control group, the individuals with ASD failed to show an inversion effect. These results point to a deficit in facial biological motion processing in people with autism, which we suggest is linked to deficits in lower level motion processing we have previously reported

The influence of the rare earth ions radii on the Low Spin to Intermediate Spin state transition in lanthanide cobaltite perovskites: LaCoO3 vs. HoCoO3

We present first principles LDA+U calculations of electronic structure and magnetic state for LaCoO3 and HoCoO3. Low Spin to Intermediate Spin state transition was found in our calculations using experimental crystallographic data for both materials with a much higher transition temperature for HoCoO3, which agrees well with the experimental estimations. Low Spin state t6e0 (non-magnetic) to Intermediate Spin state t5e1 (magnetic) transition of Co(3+) ions happens due to the competition between crystal field t_2g-e_g splitting and effective exchange interaction between 3$d$ spin-orbitals. We show that the difference in crystal structure parameters for HoCoO3 and LaCoO3 due to the smaller ionic radius of Ho ion comparing with La ion results in stronger crystal field splitting for HoCoO3 (0.09 eV ~ 1000 K larger than for LaCoO3) and hence tip the balance between the Low Spin and Intermediate Spin states to the non-magnetic solution in HoCoO3.Comment: 13 pages, 6 figure

Formation and evolution of early-type galaxies. II. Models with quasi-cosmological initial conditions

In this study, with the aid of N-Body simulations based on quasi-cosmological initial conditions, we have followed the formation and evolution of two models of early-type galaxies, from their separation from global expansion of the Universe to their collapse to virialized structures, the formation of stars and subsequent nearly passive evolution. The cosmological background we have considered is the Standard CDM. The models have significantly different nitial total mass. Particular care has been paid to the star formation process, heating and cooling of gas, and chemical enrichment. In both models star formation is completed within the first Gyrs of evolution. The structural properties of the present-day models are in good agreement with current observations. The chemical properties, mean metallicity and metallicity gradients also agree with available observational data. Finally, conspicuous galactic winds are found to occur. The models conform to the so-called revised monolithic scheme, because mergers of substructures have occurred very early in the galaxy life. Our results agree with those obtained in other similar recent studies, thus strengthening the idea that the revised monolithic scheme is the right trail to follow in the forest of galaxy formation and evolution.Comment: 21 pages, 19 figures, 3 tables. To be published on Astronomy & Astrophysics (accepted April 12, 2006

Identification of the first ATRIP-deficient patient and novel mutations in ATR define a clinical spectrum for ATR-ATRIP Seckel Syndrome

A homozygous mutational change in the Ataxia-Telangiectasia and RAD3 related (ATR) gene was previously reported in two related families displaying Seckel Syndrome (SS). Here, we provide the first identification of a Seckel Syndrome patient with mutations in ATRIP, the gene encoding ATR-Interacting Protein (ATRIP), the partner protein of ATR required for ATR stability and recruitment to the site of DNA damage. The patient has compound heterozygous mutations in ATRIP resulting in reduced ATRIP and ATR expression. A nonsense mutational change in one ATRIP allele results in a C-terminal truncated protein, which impairs ATR-ATRIP interaction; the other allele is abnormally spliced. We additionally describe two further unrelated patients native to the UK with the same novel, heterozygous mutations in ATR, which cause dramatically reduced ATR expression. All patient-derived cells showed defective DNA damage responses that can be attributed to impaired ATR-ATRIP function. Seckel Syndrome is characterised by microcephaly and growth delay, features also displayed by several related disorders including Majewski (microcephalic) osteodysplastic primordial dwarfism (MOPD) type II and Meier-Gorlin Syndrome (MGS). The identification of an ATRIP-deficient patient provides a novel genetic defect for Seckel Syndrome. Coupled with the identification of further ATR-deficient patients, our findings allow a spectrum of clinical features that can be ascribed to the ATR-ATRIP deficient sub-class of Seckel Syndrome. ATR-ATRIP patients are characterised by extremely severe microcephaly and growth delay, microtia (small ears), micrognathia (small and receding chin), and dental crowding. While aberrant bone development was mild in the original ATR-SS patient, some of the patients described here display skeletal abnormalities including, in one patient, small patellae, a feature characteristically observed in Meier-Gorlin Syndrome. Collectively, our analysis exposes an overlapping clinical manifestation between the disorders but allows an expanded spectrum of clinical features for ATR-ATRIP Seckel Syndrome to be define