5,924 research outputs found
UA37/6 Gayle Carver & L.Y. Lancaster Interview
Interviews conducted by Sara Tyler with Gayle Carver and L.Y. Lancaster. The majority of the interviews are about the history of the Kentucky Building and Kentucky Museum collections. There is also information regarding WKU in the 1910s through 1950s, student activities, WKU Bookstore, faculty and staff members, Henry Cherry and other information about the early history of WKU
Electrostatics in wind-blown sand
Wind-blown sand, or "saltation," is an important geological process, and the
primary source of atmospheric dust aerosols. Significant discrepancies exist
between classical saltation theory and measurements. We show here that these
discrepancies can be resolved by the inclusion of sand electrification in a
physically based saltation model. Indeed, we find that electric forces enhance
the concentration of saltating particles and cause them to travel closer to the
surface, in agreement with measurements. Our results thus indicate that sand
electrification plays an important role in saltation.Comment: 4 journal pages, 5 figures, and supplementary material. Article is in
press at PR
Blood pressure change and cognition in childhood and early adulthood: a systematic review
Introduction: High blood pressure in midlife is an established risk factor for cognitive decline and dementia but less is known about the impact of raised blood pressure on cognition in childhood and early adulthood. Method: We systematically reviewed and quantified the existing evidence base relating to blood pressure in early life and subsequent cognitive performance. Medline, Embase, PsycINFOo, Scopus, and Web of Science were searched from inception to July 2020. We included longitudinal cohort and caseācontrol studies involving participants aged 0ā40 years with a baseline and at least one follow-up blood pressure assessment alongside at least one measure of cognition, occurring at the same time as, or subsequent to blood pressure measures. Risk of bias was assessed independently by two reviewers. PROSPERO registration CRD42020214655. Results: Of a total of 5638 records identified, three cohort and two caseācontrol studies were included with ages ranging from 3 to early 30s. Repeated blood pressure measurements averaged over 25 years or cumulative blood pressure in the 25ā30 years prior to assessment of cognitive function were associated with poorer cognitive performance in the two largest cohort studies. The smallest cohort study reported no evidence of an association and the results from the two caseācontrol studies were contradictory. All studies were at risk of bias. Conclusion: Overall, the evidence in this area is lacking and study quality is mixed. Our review highlights an urgent need for studies evaluating the potential for a relationship between raised blood pressure and poorer cognition in early life given the potential for possible risk reduction if such a relationship exists
Diffusion on a hypercubic lattice with pinning potential: exact results for the error-catastrophe problem in biological evolution
In the theoretical biology framework one fundamental problem is the so-called
error catastrophe in Darwinian evolution models. We reexamine Eigen's
fundamental equations by mapping them into a polymer depinning transition
problem in a ``genotype'' space represented by a unitary hypercubic lattice.
The exact solution of the model shows that error catastrophe arises as a direct
consequence of the equations involved and confirms some previous qualitative
results. The physically relevant consequence is that such equations are not
adequate to properly describe evolution of complex life on the Earth.Comment: 10 pages in LaTeX. Figures are available from the authors.
[email protected] (e-mail address
Do group dynamics affect colour morph clines during a range shift?
Funded by Strategic Research Area Biodiversity and Ecosystem Services in a Changing Climate (BECC) Lund and Gothenburg Universities Wenner-Gren Foundation EU FP7 Swedish Research Council Royal Swedish Academy of Sciences (KVA) Stiftelsen Anna-Greta and Holger Crafoords Fund Crafoord FoundationPeer reviewedPostprin
Finding the Center of Mass of a Soft Spring
This article shows how to use calculus to find the center of mass position of
a soft cylindrical helical spring that is suspended vertically. The spring is
non-uniformly stretched by the action of gravity. A general expression for the
vertical position of the center of mass is obtained.Comment: LaTeX, 7 pages, 2 figures. Minor changes to agree with published
versio
Muon-spin relaxation measurements on the dimerized spin-1/2 chains NaTiSi2O6 and TiOCl
We report muon spin relaxation (muSR) and magnetic susceptibility
investigations of two Ti3+ chain compounds which each exhibit a spin gap at low
temperature, NaTiSi2O6 and TiOCl. From these we conclude that the spin gap in
NaTiSi2O6 is temperature independent, with a value of 2*Delta=660(50)K, arising
from orbital ordering at Too = 210K; the associated structural fluctuations
activate the muon spin relaxation rate up to temperatures above 270K. In TiOCl
we find thermally activated spin fluctuations corresponding to a spin gap
2*Delta=420(40)K below Tc1=67K. We also compare the methods used to extract the
spin gap and the concentration of free spins within the samples from muSR and
magnetic susceptibility data.Comment: 4 pages, 3 figure
Accelerator system for the PRISM based muon to electron conversion experiment
The next generation of lepton flavor violation experiments need high
intensity and high quality muon beams. Production of such beams requires
sending a short, high intensity proton pulse to the pion production target,
capturing pions and collecting the resulting muons in the large acceptance
transport system. The substantial increase of beam quality can be obtained by
applying the RF phase rotation on the muon beam in the dedicated FFAG ring,
which was proposed for the PRISM project.This allows to reduce the momentum
spread of the beam and to purify from the unwanted components like pions or
secondary protons. A PRISM Task Force is addressing the accelerator and
detector issues that need to be solved in order to realize the PRISM
experiment. The parameters of the required proton beam, the principles of the
PRISM experiment and the baseline FFAG design are introduced. The spectrum of
alternative designs for the PRISM FFAG ring are shown. Progress on ring main
systems like injection and RF are presented. The current status of the study
and its future directions are discussed.Comment: Studies performed within the PRISM Task Force initiativ
Signatures of local adaptation along environmental gradients in a range-expanding damselfly (Ischnura elegans)
ACKNOWLEDGEMENTSThis work was supported by an EU FP7, Marie Curie International Incoming Fellowship (to RYD; project code āMOVE2ADAPTā), a Wenner-Gren Foundation Postdoctoral Stipend (to RYD), the Oscar and Lili Lamm Foundation (to RYD, BH), Biodiversity and Ecosystem Services in a Changing Climate (BECC; a joint LundāGothenburg University initiative) (LL), the Swedish Research Council (EIS, BH),the Crafoord Foundation (EIS, BH) and Erik Philip-Sorensens Stiftelse (E.I.S.). We would like to thank Hanna Bensch and Paul Caplat for assistance with the collection of samples in the field and the Grimso Research Station and Mikael Akesson for logistical support. Wethank Pallavi Chauhan for assistance with SNP annotation. We thank Martin Andersson for assistance with DNA extraction, Jane Jonssonfor laboratory administration, and Julian Catchen, Martin Stervander, Dag Ahren and Maren Wellenreuther for bioinformatics advice and helpful discussion.Peer reviewedPostprin
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