206 research outputs found

    Antiferromagnetism from phase disordering of a d-wave superconductor

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    The unbinding of vortex defects in the superconducting condensate with d-wave symmetry at T=0 is shown to lead to the insulator with incommensurate spin-density-wave order. The transition is similar to the spontaneous generation of the "chiral" mass in the three dimensional quantum electrodynamics, at which the global chiral symmetry one can define in the superconducting state is spontaneously broken. Other symmetry related states and possible relations to recent experiments on uderdoped cuprates are briefly discussed.Comment: RevTex, 4 pages, one ps figure; comments on confinement in the SDW added, references updated; final versio

    Oribatid mites show how climate and latitudinal gradients in organic matter can drive large-scale biodiversity patterns of soil communities

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    Aim: The factors determining spatial distributions and diversity of terrestrial invertebrates are typically investigated at small scales. Large‐scale studies are lacking for soil animals, which control microbial communities and represent one of the most diverse yet poorly known animal assemblages. Here, we analyzed a major group (Oribatida) to test whether belowground macroecological patterns can be predicted by climatic variables, vegetation and large‐scale variation in key soil properties. Location: We modelled the multivariate distribution of more than 100 species using biodiversity data collected across Great Britain in the framework of the Countryside Survey (http://www.countrysidesurvey.org.uk). Methods: We analyzed species‐level data from 582 samples collected across 162 hectads (10 × 10 km) covering the largest possible range of vegetation types, soil properties and climatic conditions within GB. We created the first large‐scale maps of soil animal diversity metrics at the GB scale, including novel estimates of metrics of phylogenetic diversity (PD). Using structural equation modelling, we quantified the direct and indirect effects of location (latitude, longitude), plant community structure and abiotic factors such as precipitation on species composition, richness and PD. Results: We found that variation in species composition follows a latitudinal gradient with diversity generally increasing northward. The latitudinal variation in species composition drives PD via changes in both species richness and phylogenetic distance between species. This gradient is mostly determined by latitudinal variation in precipitation and organic matter, which were very good predictors of species composition. Precipitation and organic matter were, however, relatively weak while statistically significant predictors of diversity metrics. Conclusions: Past studies have emphasized the unpredictability of species distributions and variation in species composition in hyper diverse soil animal communities. However, past studies were conducted at small scales, where stochastic factors may weaken the signal of deterministic factors. Oribatid mites in our study show for the first time that the large scale latitudinal gradients in climate and organic matter predict not only variation in species composition but also taxonomic and PD of soil animal communities

    Composite quasiparticle formation and the low-energy effective Hamiltonians of the one- and two-dimensional Hubbard Model

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    We investigate the effect of hole doping on the strong-coupling Hubbard model at half-filling in spatial dimensions D≄1D\ge 1. We start with an antiferromagnetic mean-field description of the insulating state, and show that doping creates solitons in the antiferromagnetic background. In one dimension, the soliton is topological, spinless, and decoupled from the background antiferromagnetic fluctuations at low energies. In two dimensions and above, the soliton is non-topological, has spin quantum number 1/2, and is strongly coupled to the antiferromagnetic fluctuations. We derive the effective action governing the quasiparticle motion, study the properties of a single carrier, and comment on a possible description at finite concentration.Comment: REVTEX 3.0, 22 pages with 14 figures in the PostScript format compressed using uufile. Submitted to Phys. Rev. B. The complete PostScript file including figures can be obtained via ftp at ftp://serval.berkeley.edu/hubbard.ps . It is also available via www at http://roemer.fys.ku.dk/recent.ht

    The nucleosynthesis of heavy elements in Stars : The key isotope 25Mg

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedWe have measured the radiative neutron-capture cross section and the total neutron-induced cross section of one of the most important isotopes for the s process, the 25Mg. The measurements have been carried out at the neutron time-of-flight facilities n-TOF at CERN (Switzerland) and GELINA installed at the EC-JRC-IRMM (Belgium). The cross sections as a function of neutron energy have been measured up to approximately 300 keV, covering the energy region of interest to the s process. The data analysis is ongoing and preliminary results show the potential relevance for the s process.Peer reviewe

    Interlayer tunneling in a non-Fermi-liquid metal

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    We study the effect of interlayer tunneling in the gauge theory describing a quasi-two-dimensional paramagnetic metal close to a second-order or weakly first-order antiferromagnetic phase boundary. In that theory, two species of fermions have opposite (rather than equal) charges with respect to the gauge field. We find that single-particle interlayer tunneling is suppressed at low energies. The effect of pair tunneling is analyzed within the (3−d)(3-d) expansion. The resulting phase diagram has superconducting and non-Fermi-liquid normal phases, and so is compatible with that of the copper-oxide superconductors.Comment: 13 pages, latex, one uuencoded postscript figur

    Early reduction in painful physical symptoms is associated with improvements in long-term depression outcomes in patients treated with duloxetine

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    <p>Abstract</p> <p>Background</p> <p>To investigate the association of the change of painful physical symptoms (PPS) after 4 weeks, with the 6-month treatment outcomes of depressive symptoms in patients treated with duloxetine in clinical practice.</p> <p>Methods</p> <p>Multicenter, prospective, 6-month, non-interventional study in adult outpatients with a depressive episode and starting treatment with duloxetine. Depression severity was assessed by the clinician (Inventory for Depressive Symptomatology [IDS-C]) and patient (Kurz-Skala Stimmung/Aktivierung [KUSTA]). Somatic symptoms and PPS were assessed using the patient-rated Somatic Symptom Inventory (SSI) and visual analog scales (VAS) for pain items. Association of change in PPS with outcomes of depressive symptoms was analyzed based on mean KUSTA scores (mean of items mood, activity, tension/relaxation, sleep) and achievement of a 50% reduction in the total IDS-C score after 6 months using linear and logistic regression models, respectively.</p> <p>Results</p> <p>Of the 4,517 patients enrolled (mean age: 52.2 years, 71.8% female), 3,320 patients (73.5%) completed the study. 80% of the patients had moderate to severe overall pain (VAS > 30 mm) at baseline. A 50% VAS overall pain reduction after 4 weeks was associated with a 13.32 points higher mean KUSTA score after 6 months, and a 50% pain reduction after 2 weeks with a 6.33 points improvement. No unexpected safety signals were detected in this naturalistic study.</p> <p>Conclusion</p> <p>Pain reduction after 2 and 4 weeks can be used to estimate outcomes of long-term treatment with duloxetine. PPS associated with depression have a potential role in predicting remission of depressive symptoms in clinical practice.</p

    A multi-targeted approach to suppress tumor-promoting inflammation

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    Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-ÎșB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes
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