535 research outputs found

    Reduction and Emergence in Bose-Einstein Condensates

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    A closer look at some proposed Gedanken-experiments on BECs promises to shed light on several aspects of reduction and emergence in physics. These include the relations between classical descriptions and different quantum treatments of macroscopic systems, and the emergence of new properties and even new objects as a result of spontaneous symmetry breaking

    Granular segregation in a thin drum rotating with periodic modulation

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    We present the results of an experimental investigation into the effects of a sinusoidal modulation of the rotation rate on the segregation patterns formed in thin drum of granular material. The modulation transforms the base pattern formed under steady conditions by splitting or merging the initial streaks. Specifically, the relation between the frequency of modulation and the rotation rate determines the number of streaks which develop from the base state. The results are in accord with those of Fiedor and Ottino [J. Fluid. Mech. 533, 223 (2005)10.1017/S0022112005003952], and we show that their ideas apply over a wide range of parameter space. Furthermore, we provide evidence that the observed relationship is maintained for filling fractions far from 50% and generalize the result in terms of the geometry of the granular deposit

    Influence of ARHGEF3 and RHOA Knockdown on ACTA2 and Other Genes in Osteoblasts and Osteoclasts

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    Osteoporosis is a common bone disease that has a strong genetic component. Genome-wide linkage studies have identified the chromosomal region 3p14-p22 as a quantitative trait locus for bone mineral density (BMD). We have previously identified associations between variation in two related genes located in 3p14-p22, ARHGEF3 and RHOA, and BMD in women. In this study we performed knockdown of these genes using small interfering RNA (siRNA) in human osteoblast-like and osteoclast-like cells in culture, with subsequent microarray analysis to identify genes differentially regulated from a list of 264 candidate genes. Validation of selected findings was then carried out in additional human cell lines/cultures using quantitative real-time PCR (qRT-PCR). The qRT-PCR results showed significant down-regulation of the ACTA2 gene, encoding the cytoskeletal protein alpha 2 actin, in response to RHOA knockdown in both osteoblast-like (P<0.001) and osteoclast-like cells (P = 0.002). RHOA knockdown also caused up-regulation of the PTH1R gene, encoding the parathyroid hormone 1 receptor, in Saos-2 osteoblast-like cells (P<0.001). Other findings included down-regulation of the TNFRSF11B gene, encoding osteoprotegerin, in response to ARHGEF3 knockdown in the Saos-2 and hFOB 1.19 osteoblast-like cells (P = 0.003– 0.02), and down-regulation of ARHGDIA, encoding the Rho GDP dissociation inhibitor alpha, in response to RHOA knockdown in osteoclast-like cells (P<0.001). These studies identify ARHGEF3 and RHOA as potential regulators of a number of genes in bone cells, including TNFRSF11B, ARHGDIA, PTH1R and ACTA2, with influences on the latter evident in both osteoblast-like and osteoclast-like cells. This adds further evidence to previous studies suggesting a role for the ARHGEF3 and RHOA genes in bone metabolism

    Biotransformation of Silver Released from Nanoparticle Coated Titanium Implants Revealed in Regenerating Bone

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    Antimicrobial silver nanoparticle coatings have attracted interest for reducing prosthetic joint infection. However, few studies report in vivo investigations of the biotransformation of silver nanoparticles within the regenerating tissue and its impact on bone formation. We present a longitudinal investigation of the osseointegration of silver nanoparticle-coated additive manufactured titanium implants in rat tibial defects. Correlative imaging at different time points using nanoscale secondary ion mass spectrometry, transmission electron microscopy (TEM), histomorphometry, and 3D X-ray microcomputed tomography provided quantitative insight from the nano- to macroscales. The quality and quantity of newly formed bone is comparable between the uncoated and silver coated implants. The newly formed bone demonstrates a trabecular morphology with bone being located at the implant surface, and at a distance, at two weeks. Nanoscale elemental mapping of the bone−implant interface showed that silver was present primarily in the osseous tissue and colocalized with sulfur. TEM revealed silver sulfide nanoparticles in the newly regenerated bone, presenting strong evidence that the previously in vitro observed biotransformation of silver to silver sulfide occurs in vivo

    A non-synonymous coding change in the CYP19A1 gene Arg264Cys (rs700519) does not affect circulating estradiol, bone structure or fracture

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    Background The biosynthesis of estrogens from androgens is catalyzed by aromatase P450 enzyme, coded by the CYP19A1 gene on chromosome 15q21.2. Genetic variation within the CYP19A1 gene sequence has been shown to alter the function of the enzyme. The aim of this study is to investigate whether a non-synonymous Arg264Cys (rs700519) single nucleotide polymorphism (SNP) is associated with altered levels of circulating estradiol, areal bone mineral density or fracture. Methods This population- based study of 1,022 elderly Caucasian women (mean age 74.95 ± 2.60 years) was genotyped for the rs700519 SNP were analyzed to detect any association with endocrine and bone phenotypes. Results The genotype frequencies were 997 wildtype (97.6%), 24 heterozygous (2.3%) and 1 homozygous (0.1%). When individuals were grouped by genotype, there was no association between the polymorphism and serum estradiol (wildtype 27.5 ± 16.0; variants 31.2 ± 18.4, P = 0.27). There was also no association seen on hip bone mineral density (wildtype 0.81 ± 0.12; 0.84 ± 0.14 for variants, P = 0.48) or femoral neck bone mineral density (0.69 ± 0.10 for wildtype; 0.70 ± 0.12 for variants, P = 0.54) before or after correction of the data with age, height, weight and calcium therapy. There were also no associations with quantitative ultrasound measures of bone structure (broadband ultrasound attenuation, speed of sound and average stiffness). Conclusions In a cohort of 1,022 elderly Western Australian women, the presence of Arg264Cys (rs700519) polymorphism was not found to be associated with serum estradiol, bone structure or phenotypes

    Identification of novel loci associated with hip shape:a meta-analysis of genome-wide association studies

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    This study was funded by Arthritis Research UK project grant 20244, which also provided salary funding for DB and CVG. LP works in the MRC Integrative Epidemiology Unit, a UK MRC‐funded unit (MC_ UU_ 12013/4 & MC_UU_12013/5). ALSPAC: We are extremely grateful to all the families who took part in this study, the midwives for their help in recruiting them, and the whole ALSPAC team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists, and nurses. ALSPAC data collection was supported by the Wellcome Trust (grants WT092830M; WT088806; WT102215/2/13/2), UK Medical Research Council (G1001357), and University of Bristol. The UK Medical Research Council and the Wellcome Trust (102215/2/13/2) and the University of Bristol provide core support for ALSPAC. Framingham Heart Study: The Framingham Osteoporosis Study is supported by grants from the National Institute of Arthritis, Musculoskeletal, and Skin Diseases and the National Institute on Aging (R01 AR41398, R01 AR 061162, R01 AR050066, and R01 AR061445). The analyses reflect intellectual input and resource development from the Framingham Heart Study investigators participating in the SNP Health Association Resource project. The Framingham Heart Study of the National Heart, Lung, and Blood Institute of the National Institutes of Health and Boston University School of Medicine were supported by the National Heart, Lung, and Blood Institute's Framingham Heart Study (N01‐HC‐25195) and its contract with Affymetrix, Inc., for genotyping services (N02‐HL‐6‐4278). Analyses reflect intellectual input and resource development from the Framingham Heart Study investigators participating in the SNP Health Association Resource (SHARe) project. A portion of this research was conducted using the Linux Cluster for Genetic Analysis (LinGA‐II) funded by the Robert Dawson Evans Endowment of the Department of Medicine at Boston University School of Medicine and Boston Medical Center. DK was also supported by Israel Science Foundation grant #1283/14. TDC and DR thank Dr Claire Reardon and the entire Harvard University Bauer Core facility for assistance with ATAC‐seq next generation sequencing. This work was funded in part by the Harvard University Milton Fund, NSF (BCS‐1518596), and NIH NIAMS (1R01AR070139‐01A1) to TDC. MrOS: The Osteoporotic Fractures in Men (MrOS) Study is supported by National Institutes of Health funding. The following institutes provide support: the National Institute on Aging (NIA), the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the National Center for Advancing Translational Sciences (NCATS), and NIH Roadmap for Medical Research under the following grant numbers: U01 AG027810, U01 AG042124, U01 AG042139, U01 AG042140, U01 AG042143, U01 AG042145, U01 AG042168, U01 AR066160, and UL1 TR000128. The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) provides funding for the MrOS ancillary study “Replication of candidate gene associations and bone strength phenotype in MrOS” under the grant number R01 AR051124. The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) provides funding for the MrOS ancillary study “GWAS in MrOS and SOF” under the grant number RC2 AR058973. SOF: The Study of Osteoporotic Fractures (SOF) is supported by National Institutes of Health funding. The National Institute on Aging (NIA) provides support under the following grant numbers: R01 AG005407, R01 AR35582, R01 AR35583, R01 AR35584, R01 AG005394, R01 AG027574, and R01 AG027576. TwinsUK: The study was funded by the Wellcome Trust; European Community's Seventh Framework Programme (FP7/2007‐2013). The study also receives support from the National Institute for Health Research (NIHR)‐funded BioResource, Clinical Research Facility, and Biomedical Research Centre based at Guy's and St Thomas’ NHS Foundation Trust in partnership with King's College London. SNP genotyping was performed by The Wellcome Trust Sanger Institute and National Eye Institute via NIH/CIDR. This study was also supported by the Australian National Health and Medical Research Council (project grants 1048216 and 1127156), the Sir Charles Gairdner Hospital RAC (SGW), and the iVEC/Pawsey Supercomputing Centre (project grants Pawsey0162 and Director2025 [SGW]). The salary of BHM was supported by a Raine Medical Research Foundation Priming Grant. The Umeå Fracture and Osteoporosis Study (UFO) is supported by the Swedish Research Council (K20006‐72X‐20155013), the Swedish Sports Research Council (87/06), the Swedish Society of Medicine, the Kempe‐Foundation (JCK‐1021), and by grants from the Medical Faculty of Umeå Unviersity (ALFVLL:968:22‐2005, ALFVL:‐937‐2006, ALFVLL:223:11‐2007, and ALFVLL:78151‐2009) and from the county council of Västerbotten (Spjutspetsanslag VLL:159:33‐2007). This publication is the work of the authors and does not necessarily reflect the views of any funders. None of the funders had any influence on data collection, analysis, interpretation of the results, or writing of the paper. DB will serve as the guarantor of the paper. Authors’ roles: Study conception and design: DAB, JSG, RMA, LP, DK, and JHT. Data collection: DJ, DPK, ESO, SRC, NEL, BHM, FMKW, JBR, SGW, TDC, BGF, DAL, CO, and UP‐L. Data analysis: DAB, DSE, FKK, JSG, FRS, CVG, RJB, RMA, SGW, EG, TDC, DR, and TB. Data interpretation: JSG, RMA, TDC, DR, DME, LP, DK, and JHT. Drafting manuscript: DAB and JHT. Revising manuscript content: JHT. All authors approved the final version of manuscript. DAB takes responsibility for the integrity of the data analysis.Peer reviewedPublisher PD

    Measurement of associated Z plus charm production in proton-proton collisions at root s=8TeV

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    A study of the associated production of a Z boson and a charm quark jet (Z + c), and a comparison to production with a b quark jet (Z + b), in pp collisions at a centre-of-mass energy of 8 TeV are presented. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb(-1), collected with the CMS detector at the CERN LHC. The Z boson candidates are identified through their decays into pairs of electrons or muons. Jets originating from heavy flavour quarks are identified using semileptonic decays of c or b flavoured hadrons and hadronic decays of charm hadrons. The measurements are performed in the kinematic region with two leptons with pT(l) > 20 GeV, vertical bar eta(l)vertical bar 25 GeV and vertical bar eta(jet)vertical bar Z + c + X) B(Z -> l(+)l(-)) = 8.8 +/- 0.5 (stat)+/- 0.6 (syst) pb. The ratio of the Z+c and Z+b production cross sections is measured to be sigma(pp -> Z+c+X)/sigma (pp -> Z+b+X) = 2.0 +/- 0.2 (stat)+/- 0.2 (syst). The Z+c production cross section and the cross section ratio are also measured as a function of the transverse momentum of theZ boson and of the heavy flavour jet. The measurements are compared with theoretical predictions.Peer reviewe

    Measurement of the underlying event activity in inclusive Z boson production in proton-proton collisions at root s=13 TeV

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    This paper presents a measurement of the underlying event activity in proton-proton collisions at a center-of-mass energy of 13TeV, performed using inclusive Z boson production events collected with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 2.1 fb(-1). The underlying event activity is quantified in terms of the charged particle multiplicity, as well as of the scalar sum of the charged particles' transverse momenta in different topological regions defined with respect to the Z boson direction. The distributions are unfolded to the stable particle level and compared with predictions from various Monte Carlo event generators, as well as with similar CDF and CMS measurements at center-of-mass energies of 1.96 and 7TeV respectively.Peer reviewe

    Measurement of differential cross sections in the kinematic angular variable phi* for inclusive Z boson production in pp collisions at root s=8 TeV

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    Measurements of differential cross sections d sigma/d phi* and double-differential cross sections d(2)sigma/ld phi*d/y/ for inclusive Z boson production are presented using the dielectron and dimuon final states. The kinematic observable phi* correlates with the dilepton transverse momentum but has better resolution, and y is the dilepton rapidity. The analysis is based on data collected with the CMS experiment at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb(-1). The normalised cross section (1/sigma) d sigma/d phi*, within the fiducial kinematic region, is measured with a precision of better than 0.5% for phi* <1. The measurements are compared to theoretical predictions and they agree, typically, within few percent.Peer reviewe

    Author Correction: Multi-ancestry genome-wide association analyses improve resolution of genes and pathways influencing lung function and chronic obstructive pulmonary disease risk

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