183 research outputs found
Temperature drives pre-reproductive selection and shapes the biogeography of a female polymorphism
Acknowledgements We are grateful to the many field assistants, PhD students and postdocs who have participated in the field work and thereby directly and indirectly contributed to this study over many years, since 2000 when it was started. We also wish to thank David and Rosalyn Sparrow who kindly hosted B. Willink during a field trip to Cyprus in 2017 and who provided valuable field work help and guidance, enabling us to gather information about morph frequencies of I. elegans at one of the southernmost localities of this species in Europe. Funding information Funding for this study has been provided by research grants from The Swedish Research Council (VR: grant no. 2016‐03356), Carl Tryggers Foundation (CTS), Gyllenstiernska Krapperupstiftelsen (grant no. KR2018‐0038), Stina Werners Foundation and Erik Philip Sörensens Stiftelse to E.I.S.Peer reviewedPostprin
First Principles NMR Study of Fluorapatite under Pressure
NMR is the technique of election to probe the local properties of materials.
Herein we present the results of density functional theory (DFT) \textit{ab
initio} calculations of the NMR parameters for fluorapatite (FAp), a calcium
orthophosphate mineral belonging to the apatite family, by using the GIPAW
method [Pickard and Mauri, 2001]. Understanding the local effects of pressure
on apatites is particularly relevant because of their important role in many
solid state and biomedical applications. Apatites are open structures, which
can undergo complex anisotropic deformations, and the response of NMR can
elucidate the microscopic changes induced by an applied pressure. The computed
NMR parameters proved to be in good agreement with the available experimental
data. The structural evaluation of the material behavior under hydrostatic
pressure (from --5 to +100 kbar) indicated a shrinkage of the diameter of the
apatitic channel, and a strong correlation between NMR shielding and pressure,
proving the sensitivity of this technique to even small changes in the chemical
environment around the nuclei. This theoretical approach allows the exploration
of all the different nuclei composing the material, thus providing a very
useful guidance in the interpretation of experimental results, particularly
valuable for the more challenging nuclei such as Ca and O.Comment: 8 pages, 2 figures, 3 table
Structure and Dynamics of Liquid Iron under Earth's Core Conditions
First-principles molecular dynamics simulations based on density-functional
theory and the projector augmented wave (PAW) technique have been used to study
the structural and dynamical properties of liquid iron under Earth's core
conditions. As evidence for the accuracy of the techniques, we present PAW
results for a range of solid-state properties of low- and high-pressure iron,
and compare them with experimental values and the results of other
first-principles calculations. In the liquid-state simulations, we address
particular effort to the study of finite-size effects, Brillouin-zone sampling
and other sources of technical error. Results for the radial distribution
function, the diffusion coefficient and the shear viscosity are presented for a
wide range of thermodynamic states relevant to the Earth's core. Throughout
this range, liquid iron is a close-packed simple liquid with a diffusion
coefficient and viscosity similar to those of typical simple liquids under
ambient conditions.Comment: 13 pages, 8 figure
Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of the availability of the generic name and for the nomenclatural validation of the journal in which it was published
Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures
Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
The oviposition behaviour of Callosobruchus maculatus (Fabricius)
SIGLEAvailable from British Library Document Supply Centre-DSC:DX193428 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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