Effects of incubation time and filtration method on Kd of indigenous selenium and iodine in temperate soils

In this study, the effects of incubation time and the method of soil solution extraction and filtration on the empirical distribution coefficient (Kd) obtained by de-sorbing indigenous selenium (Se) and iodine (I) from arable and woodland soils under temperate conditions were investigated. Incubation time had a significant soil- and element- dependent effect on the Kd values, which tended to decrease with the incubation time. Generally, a four-week period was sufficient for the desorption Kd value to stabilise. Concurrent solubilisation of soil organic matter (OM) and release of organically-bound Se and I was probably responsible for the observed decrease in Kd with time. This contrasts with the conventional view of OM as a sink for Se and I in soils. Selenium and I Kd values were not significantly affected by the method of soil solution extraction and filtration. The results suggest that incubation time is a key criterion when selecting Se and I Kd values from the literature for risk assessments. Values derived from desorption of indigenous soil Se and I might be most appropriate for long-term assessments since they reflect the quasi-equilibrium state of their partitioning in soils

GPCR-OKB: the G protein coupled receptor oligomer knowledge base

Rapid expansion of available data about G Protein Coupled Receptor (GPCR) dimers/oligomers over the past few years requires an effective system to organize this information electronically. Based on an ontology derived from a community dialog involving colleagues using experimental and computational methodologies, we developed the GPCR-Oligomerization Knowledge Base (GPCR-OKB). GPCR-OKB is a system that supports browsing and searching for GPCR oligomer data. Such data were manually derived from the literature. While focused on GPCR oligomers, GPCR-OKB is seamlessly connected to GPCRDB, facilitating the correlation of information about GPCR protomers and oligomers

The influence of clouds on radical concentrations: Observations and modelling studies of HOx during the Hill Cap Cloud Thuringia (HCCT) campaign in 2010

The potential for chemistry occurring in cloud droplets to impact atmospheric composition has been known for some time. However, the lack of direct observations and uncertainty in the magnitude of these reactions led to this area being overlooked in most chemistry transport models. Here we present observations from Mt Schmücke, Germany, of the HO2 radical made alongside a suite of cloud measurements. HO2 concentrations were depleted in-cloud by up to 90% with the rate of heterogeneous loss of HO2 to clouds necessary to bring model and measurements into agreement, demonstrating a dependence on droplet surface area and pH. This provides the first observationally derived assessment for the uptake coefficient of HO2 to cloud droplets and was found to be in good agreement with theoretically derived parameterisations. Global model simulations, including this cloud uptake, showed impacts on the oxidising capacity of the troposphere that depended critically on whether the HO2 uptake leads to production of H2O2 or H2O

N=31, D=11

We show that eleven-dimensional supergravity backgrounds with thirty one supersymmetries, N=31, admit an additional Killing spinor and so they are locally isometric to maximally supersymmetric ones. This rules out the existence of simply connected eleven-dimensional supergravity preons. We also show that N=15 solutions of type I supergravities are locally isometric to Minkowski spacetime.Comment: 17 page

Toeplitz operators on symplectic manifolds

We study the Berezin-Toeplitz quantization on symplectic manifolds making use of the full off-diagonal asymptotic expansion of the Bergman kernel. We give also a characterization of Toeplitz operators in terms of their asymptotic expansion. The semi-classical limit properties of the Berezin-Toeplitz quantization for non-compact manifolds and orbifolds are also established.Comment: 40 page

On the Testing of Seismicity Models

Recently a likelihood-based methodology has been developed by the Collaboratory for the Study of Earthquake Predictability (CSEP) with a view to testing and ranking seismicity models. We analyze this approach from the standpoint of possible applications to hazard analysis. We arrive at the conclusion that model testing can be made more efficient by focusing on some integral characteristics of the seismicity distribution. This is achieved either in the likelihood framework but with economical and physically reasonable coarsening of the phase space or by choosing a suitable measure of closeness between empirical and model seismicity rate in this space.Comment: To appear at Acta Geophysic

Linewidth of single photon transitions in Mn12_{12}-acetate

We use time-domain terahertz spectroscopy to measure the position and linewidth of single photon transitions in Mn$_{12}$-acetate. This linewidth is compared to the linewidth measured in tunneling experiments. We conclude that local magnetic fields (due to dipole or hyperfine interactions) cannot be responsible for the observed linewidth, and suggest that the linewidth is due to variations in the anisotropy constants for different clusters. We also calculate a lower limit on the dipole field distribution that would be expected due to random orientations of clusters and find that collective effects must narrow this distribution in tunneling measurements.Comment: 5 pages, accepted to Physical Review

Daily Parent-Adolescent Digital Exchanges

The present study tracked adolescents via mobile phones to describe how parents and their adolescent children are using digital technologies in daily life (i.e. facilitating warmth and behavioral control), and whether these uses are associated with the quality of offline parent-adolescent interactions and with adolescents’ mental health. A sample of young adolescents (N = 388; mean age 13.37) completed a 14-day ecological momentary assessment in 2016- 2017, reporting on their daily digital contact and offline interactions with their parents and their mental health. Adolescents reported using texting and calling to communicate somewhat infrequently with their parents (i.e., on 29% of days), but days with more digital contacts (for both warmth and behavioral control) were also more likely to be characterized by more positive offline interactions with parents. Furthermore, adolescents struggling with mental health symptoms across the study period reported using texts/calls more frequently to seek out parent support, and parents were more likely to do text/call “check ins” on young people who were experiencing more behavioral problems. Results highlight the potential for digital communication devices to be used as tools in fostering parent-adolescent connection, support provision, and behavioral control in the digital era

Migration transforms the conditions for the achievement of the Sustainable Development Goals

This is the final version. Available on open access from Elsevier via the DOI in this recordEconomic and Social Research Council (ESRC

The holonomy of the supercovariant connection and Killing spinors

We show that the holonomy of the supercovariant connection for M-theory backgrounds with $N$ Killing spinors reduces to a subgroup of SL(32-N,\bR)\st (\oplus^N \bR^{32-N}). We use this to give the necessary and sufficient conditions for a background to admit $N$ Killing spinors. We show that there is no topological obstruction for the existence of up to 22 Killing spinors in eleven-dimensional spacetime. We investigate the symmetry superalgebras of supersymmetric backgrounds and find that their structure constants are determined by an antisymmetric matrix. The Lie subalgebra of bosonic generators is related to a real form of a symplectic group. We show that there is a one-one correspondence between certain bases of the Cartan subalgebra of sl(32, \bR) and supersymmetric planar probe M-brane configurations. A supersymmetric probe configuration can involve up to 31 linearly independent planar branes and preserves one supersymmetry. The space of supersymmetric planar probe M-brane configurations is preserved by an SO(32,\bR) subgroup of SL(32, \bR).Comment: 27 pages, a key reference was added. v3: minor change