75 research outputs found
Geomagnetically Induced Currents in the Irish Power Network during Geomagnetic Storms
Geomagnetically induced currents (GICs) are a well-known terrestrial space
weather hazard. They occur in power transmission networks and are known to have
adverse effects in both high and mid-latitude countries. Here, we study GICs in
the Irish power transmission network (geomagnetic latitude 54.7--58.5
N) during five geomagnetic storms (06-07 March 2016, 20-21 December 2015, 17-18
March 2015, 29-31 October 2003 and 13-14 March 1989). We simulate electric
fields using a plane wave method together with two ground resistivity models,
one of which is derived from magnetotelluric measurements (MT model). We then
calculate GICs in the 220, 275 and 400~kV transmission network. During the
largest of the storm periods studied, the peak electric field was calculated to
be as large as 3.8~V~km\textsuperscript{-1}, with associated GICs of up to 23~A
using our MT model. Using our homogenous resistivity model, those peak values
were 1.46~V~km\textsuperscript{-1} and 25.8~A. We find that three 400 and
275~kV substations are the most likely locations for the Irish transformers to
experience large GICs.Comment: 14 pages, 11 Figures, 4 Table
A Multi-Faceted Approach of One Teaching Hospital NHS Trust during the Clostridium difficile Epidemic—Antibiotic Management and Beyond
The incidence of Clostridium difficile infection (CDI) in the UK rose dramatically during the early years of this century, in part associated with the emergence of the hyper-virulent ribotype 027 strain. The University Hospitals of Leicester (UHL), a 2000-bed acute UK NHS Trust, implemented a number of interventions, which led to an 80% reduction in new cases over a twelve month period. Changes were introduced as a result of collaboration between the Infection Prevention team, the departments of Microbiology and Infectious Diseases, and with the support of the Trust Executive. These strategies are described in detail and included; implementation of antimicrobial stewardship, specific hygiene and cleaning measures, the introduction of a care pathway form for all infected patients, the opening of an isolation ward for patients with CDI, strengthened organisation and clinical management, and rigorous attention to education within the Trust. The implementations described are of continued relevance in the face of new infection challenges, such as the increasing incidence of multi-drug resistant organisms
Tutorial on means of hybrid simulation
The benefits of Hybrid Simulation (HS) are well recorded in academic literature. It offers deeper insights into the real-life system as it allows modelers to assess its inherent problems from different dimensions. As a result HS has recently generated more attention from within the Modeling and Simulation arena. HS comes in many shapes and forms. For example, by linking two or more simulation models; linking simulation models with facilitative models; or linking simulation models with analytical models. This paper aims to explore several concepts related to HS modelling and design
Polarizable Multipole-Based Force Field for Aromatic Molecules and Nucleobases
Aromatic molecules with π electrons
are commonly involved
in chemical and biological recognitions. For example, nucleobases
play central roles in DNA/RNA structure and their interactions with
proteins. The delocalization of the π electrons is responsible
for the high polarizability of aromatic molecules. In this work, the
AMOEBA force field has been developed and applied to 5 regular nucleobases
and 12 aromatic molecules. The permanent electrostatic energy is expressed
as atomic multipole interactions between atom pairs, and many-body
polarization is accounted for by mutually induced atomic dipoles.
We have systematically investigated aromatic ring stacking and aromatic-water
interactions for nucleobases and aromatic molecules, as well as base–base
hydrogen-bonding pair interactions, all at various distances and orientations.
van der Waals parameters were determined by comparison to the quantum
mechanical interaction energy of these dimers and fine-tuned using
condensed phase simulation. By comparing to quantum mechanical calculations,
we show that the resulting classical potential is able to accurately
describe molecular polarizability, molecular vibrational frequency,
and dimer interaction energy of these aromatic systems. Condensed
phase properties, including hydration free energy, liquid density,
and heat of vaporization, are also in good overall agreement with
experimental values. The structures of benzene liquid phase and benzene-water
solution were also investigated by simulation and compared with experimental
and PDB structure derived statistical results
Polarizable Multipole-Based Force Field for Aromatic Molecules and Nucleobases
Aromatic molecules with π electrons
are commonly involved
in chemical and biological recognitions. For example, nucleobases
play central roles in DNA/RNA structure and their interactions with
proteins. The delocalization of the π electrons is responsible
for the high polarizability of aromatic molecules. In this work, the
AMOEBA force field has been developed and applied to 5 regular nucleobases
and 12 aromatic molecules. The permanent electrostatic energy is expressed
as atomic multipole interactions between atom pairs, and many-body
polarization is accounted for by mutually induced atomic dipoles.
We have systematically investigated aromatic ring stacking and aromatic-water
interactions for nucleobases and aromatic molecules, as well as base–base
hydrogen-bonding pair interactions, all at various distances and orientations.
van der Waals parameters were determined by comparison to the quantum
mechanical interaction energy of these dimers and fine-tuned using
condensed phase simulation. By comparing to quantum mechanical calculations,
we show that the resulting classical potential is able to accurately
describe molecular polarizability, molecular vibrational frequency,
and dimer interaction energy of these aromatic systems. Condensed
phase properties, including hydration free energy, liquid density,
and heat of vaporization, are also in good overall agreement with
experimental values. The structures of benzene liquid phase and benzene-water
solution were also investigated by simulation and compared with experimental
and PDB structure derived statistical results
MOESM1 of Development of new malaria diagnostics: matching performance and need
Additional file 1: Annex S1. Example target product profiles for malaria diagnostic markets
Appendix B. Relationship between structural and temporal forest variables and beetle community structure (transformed data).
Relationship between structural and temporal forest variables and beetle community structure (transformed data)
Appendix A. Relationship between structural and temporal forest variables and beetle community structure (untransformed data).
Relationship between structural and temporal forest variables and beetle community structure (untransformed data)
Confocal Raman Microscopy of Protein Adsorbed in Chromatographic Particles
Confocal Raman microscopy is a nondestructive analytical
technique
that combines the chemical information from vibrational spectroscopy
with the spatial resolution of confocal microscopy. It was applied,
for the first time, to measure conformation and distribution of protein
adsorbed in wetted chromatographic particles. Monoclonal antibody
was loaded into the Fractogel EMD SO<sub>3</sub> (M) cation exchanger
at 2 mS/cm or 10 mS/cm. Amide I and III frequencies in the Raman spectrum
of the adsorbed protein suggest that there are no detectable changes
of the original β-sheet conformation in the chromatographic
particles. Protein depth profile measurements indicate that, when
the conductivity is increased from 2 mS/cm to 10 mS/cm, there is a
change in mass transport mechanism for protein adsorption, from the
shrinking-core model to the homogeneous-diffusion model. In this study,
the use of confocal Raman microscopy to measure protein distribution
in chromatographic particles fundamentally agrees with previous confocal
laser scanning microscopic investigations, but confocal Raman spectroscopy
enjoys additional advantages: use of unlabeled protein to eliminate
fluorescent labeling, ability for characterization of protein secondary
structure, and ability for spectral normalization to provide a nondestructive
experimental approach to correct light attenuation effects caused
by refractive index (RI) mismatching in semiopaque chromatographic
particles
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