1,158 research outputs found
Fine-scale movement of the European hedgehog: An application of spool-and-thread tracking
The European hedgehog is a significant predator species of rare and endangered ground-nesting birds in the riverbeds of the Waitaki Basin, South Island, New Zealand. Studies focusing on the movements and habits of this species have generally been limited to broad-scale radio-tracking studies or incidental trap-catch data. Within our study, we aimed to investigate the finer scale movement patterns of the hedgehog in relation to vegetation structure by using spool-and-thread tracking. We captured 30 hedgehogs (15 female, 15 male) within the study area, and spool-and-thread-tracked the movements of each over a single night. Only two of the 30 animals moved onto the gravel areas of the riverbeds where birds nest - hedgehogs may therefore not target birds' nests as a primary prey source, but rather as a secondary prey item. The movement paths were all non-random, and males demonstrated particular linearity in their tracks. This straighter and more directed movement may be due to more intensive male search at this time of the year. We also assessed habitat use using a very high resolution habitat map (derived from Ikonos 4-m-resolution satellite image). Dense grassland was the most selected habitat type, perhaps because insect prey are at a higher density in this vegetation type. Hedgehogs (particularly males) also used boundaries of all habitat types significantly more than the centre of habitat patches. We found the spool-and-thread tracking technique does have limitations: (1) it could be inappropriate for animals exhibiting a significant escape response; (2) the data do not include a temporal dimension. However, these problems were not considered relevant for this study. Fine-scale studies such as this can provide increased power when investigating the ecology of species at a scale relevant to trap placement
Exercise and the microbiota
The authors are supported in part by research grants from Science Foundation Ireland including a centre grant (Alimentary Pharmabiotic Centre; Grant Numbers SFI/12/RC/2273 and 12/RC/2273). Dr. Orla O’Sullivan is funded by a Starting Investigator Research Grant from Science Foundation Ireland (Grant number 13/SIRG/2160). Dr. Paul Cotter is funded by a Principal Investigator Award from Science Foundation Ireland P.D.C are supported by a SFI PI award (Grant number 11/PI/1137).peer-reviewedSedentary lifestyle is linked with poor health, most commonly obesity and associated disorders, the corollary being that exercise offers a preventive strategy. However, the scope of exercise biology extends well beyond energy expenditure and has emerged as a great ‘polypill’, which is safe, reliable and cost-effective not only in disease prevention but also treatment. Biological mechanisms by which exercise influences homeostasis are becoming clearer and involve multi-organ systemic adaptations. Most of the elements of a modern lifestyle influence the indigenous microbiota but few studies have explored the effect of increased physical activity. While dietary responses to exercise obscure the influence of exercise alone on gut microbiota, professional athletes operating at the extremes of performance provide informative data. We assessed the relationship between extreme levels of exercise, associated dietary habits and gut microbiota composition, and discuss potential mechanisms by which exercise may exert a direct or indirect influence on gut microbiota.The authors are supported in part by research grants from Science Foundation Ireland including a centre grant (Alimentary Pharmabiotic Centre; Grant Numbers SFI/12/RC/2273 and 12/RC/2273). Dr. Orla O’Sullivan is funded by a Starting Investigator Research Grant from Science Foundation Ireland (Grant number 13/SIRG/2160). Dr. Paul Cotter is funded by a Principal Investigator Award from Science Foundation Ireland P.D.C are supported by a SFI PI award (Grant number 11/PI/1137)
Characterization of maize physiological responses to nitrogen stress by using chlorophyll fluorescence and gas exchange measurements.
Suplemento. Edição dos resumos do IX Congresso Brasileiro de Fisiologia Vegetal, 2003, Atibaia, SP
Ucma/GRP inhibits phosphate-induced vascular smooth muscle cell calcification via SMAD-dependent BMP signalling
Vascular calcification (VC) is the process of deposition of calcium phosphate crystals in the blood vessel wall, with a central role for vascular smooth muscle cells (VSMCs). VC is highly prevalent in chronic kidney disease (CKD) patients and thought, in part, to be induced by phosphate imbalance. The molecular mechanisms that regulate VC are not fully known. Here we propose a novel role for the mineralisation regulator Ucma/GRP (Upper zone of growth plate and Cartilage Matrix Associated protein/Gla Rich Protein) in phosphate-induced VSMC calcification. We show that Ucma/GRP is present in calcified atherosclerotic plaques and highly expressed in calcifying VSMCs in vitro. VSMCs from Ucma/GRP(-/-) mice showed increased mineralisation and expression of osteo/chondrogenic markers (BMP-2, Runx2, beta-catenin, p-SMAD1/5/8, ALP, OCN), and decreased expression of mineralisation inhibitor MGP, suggesting that Ucma/GRP is an inhibitor of mineralisation. Using BMP signalling inhibitor noggin and SMAD1/5/8 signalling inhibitor dorsomorphin we showed that Ucma/GRP is involved in inhibiting the BMP-2-SMAD1/5/8 osteo/chondrogenic signalling pathway in VSMCs treated with elevated phosphate concentrations. Additionally, we showed for the first time evidence of a direct interaction between Ucma/GRP and BMP-2. These results demonstrate an important role of Ucma/GRP in regulating osteo/chondrogenic differentiation and phosphate-induced mineralisation of VSMCs.NWO ZonMw [MKMD 40-42600-98-13007]; FCT [SFRH/BPD/70277/2010]info:eu-repo/semantics/publishedVersio
Redox-neutral organocatalytic Mitsunobu reactions
Nucleophilic substitution reactions of alcohols are amongst the most fundamental and strategically important transformations in organic chemistry. For over half a century these reactions have been achieved using stoichiometric, and often hazardous, reagents to activate the otherwise unreactive alcohols. Here we demonstrate that a specially designed phosphine oxide promotes nucleophilic substitution reactions of primary and secondary alcohols within a redoxneutral catalysis manifold that produces water as the sole by-product. The scope of the catalytic coupling process encompasses a range of acidic pronucleophiles that allow stereospecific construction of carbon-oxygen and carbon-nitrogen bonds
Mixing of scalar glueballs and flavour-singlet scalar mesons
We discuss in detail the extraction of hadronic mixing strengths from lattice
studies. We apply this to the mixing of a scalar glueball and a scalar meson in
the quenched approximation. We also measure correlations appropriate for
flavour-singlet scalar mesons using dynamical quark configurations from UKQCD.
This enables us to compare the results from the quenched study of the mixing
with the direct determination of the mixed spectrum. Improved methods of
evaluating the disconnected quark diagrams are also presented.Comment: 23 pages, 5 postscript figure
Molecular transport and flow past hard and soft surfaces: Computer simulation of model systems
The properties of polymer liquids on hard and soft substrates are
investigated by molecular dynamics simulation of a coarse-grained bead-spring
model and dynamic single-chain-in-mean-field (SCMF) simulations of a soft,
coarse-grained polymer model. Hard, corrugated substrates are modelled by an
FCC Lennard-Jones solid while polymer brushes are investigated as a
prototypical example of a soft, deformable surface. From the molecular
simulation we extract the coarse-grained parameters that characterise the
equilibrium and flow properties of the liquid in contact with the substrate:
the surface and interface tensions, and the parameters of the hydrodynamic
boundary condition. The so-determined parameters enter a continuum description
like the Stokes equation or the lubrication approximation.Comment: 41 pages, 13 figure
Using Heavy Quark Spin Symmetry in Semileptonic Decays
The form factors parameterizing the B_c semileptonic matrix elements can be
related to a few invariant functions if the decoupling of the spin of the heavy
quarks in B_c and in the mesons produced in the semileptonic decays is
exploited. We compute the form factors as overlap integral of the meson
wave-functions obtained using a QCD relativistic potential model, and give
predictions for semileptonic and non-leptonic B_c decay modes. We also discuss
possible experimental tests of the heavy quark spin symmetry in B_c decays.Comment: RevTex, 22 pages, 2 figure
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