3,697,310 research outputs found

    Running the running

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    We use the recent observations of Cosmic Microwave Background temperature and polarization anisotropies provided by the Planck satellite experiment to place constraints on the running αs=dns/dlogk\alpha_\mathrm{s} = \mathrm{d}n_{\mathrm{s}} / \mathrm{d}\log k and the running of the running βs=dαs/dlogk\beta_{\mathrm{s}} = \mathrm{d}\alpha_{\mathrm{s}} / \mathrm{d}\log k of the spectral index nsn_{\mathrm{s}} of primordial scalar fluctuations. We find αs=0.011±0.010\alpha_\mathrm{s}=0.011\pm0.010 and βs=0.027±0.013\beta_\mathrm{s}=0.027\pm0.013 at 68%CL68\%\,\mathrm{CL}, suggesting the presence of a running of the running at the level of two standard deviations. We find no significant correlation between βs\beta_{\mathrm{s}} and foregrounds parameters, with the exception of the point sources amplitude at 143GHz143\,\mathrm{GHz}, A143PSA^{PS}_{143}, which shifts by half sigma when the running of the running is considered. We further study the cosmological implications of such preference for αs,βs0.01\alpha_\mathrm{s},\beta_\mathrm{s}\sim0.01 by including in the analysis the lensing amplitude ALA_L, the curvature parameter Ωk\Omega_k, and the sum of neutrino masses mν\sum m_{\nu}. We find that when the running of the running is considered, Planck data are more compatible with the standard expectations of AL=1A_L = 1 and Ωk=0\Omega_k = 0 but still hint at possible deviations. The indication for βs>0\beta_\mathrm{s} > 0 survives at two standard deviations when external datasets such as BAO and CFHTLenS are included in the analysis, and persists at 1.7\sim 1.7 standard deviations when CMB lensing is considered. We discuss the possibility of constraining βs\beta_\mathrm{s} with current and future measurements of CMB spectral distortions, showing that an experiment like PIXIE could provide strong constraints on αs\alpha_\mathrm{s} and βs\beta_\mathrm{s}.Comment: 10+1 pages, 9 figures, 10 tables. Matches published versio

    Mutations in the PERIANTHIA gene of Arabidopsis specifically alter floral organ number and initiation pattern

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    An open question in developmental biology is how groups of dividing cells can generate specific numbers of segments or organs. We describe the phenotypic effects of mutations in PERIANTHIA, a gene specifically required for floral organ patterning in Arabidopsis thaliana. Most wild-type Arabidopsis flowers have 4 sepals, 4 petals, 6 stamens, and 2 carpels. Flowers of perianthia mutant plants most commonly show a pentamerous pattern of 5 sepals, 5 petals 5 stamens, and 2 carpels. This pattern is characteristic of flowers in a number of plant families, but not in the family Brassicaceae, which includes Arabidopsis. Unlike previously described mutations affecting floral organ number, perianthia does not appear to affect apical or floral meristem sizes, nor is any other aspect of vegetative or floral development severely affected. Floral organs in perianthia arise in a regular, stereotypical pattern similar to that in distantly related species with pentamerous flowers. Genetic analysis shows that PERIANTHIA acts downstream of the floral meristem identity genes and independently of the floral meristem size and floral organ identity genes in establishing floral organ initiation patterns. Thus PERIANTHIA acts in a previously unidentified process required for organ patterning in Arabidopsis flowers

    TSO1 functions in cell division during Arabidopsis flower development

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    We describe an Arabidopsis mutant, tso1, which develops callus-like tissues in place of floral organs. The tso1 floral meristem lacks properly organized three cell layers, and the nuclei of these cells are irregular in size and shape. Further analyses reveal partially formed cell walls and increased DNA ploidy in tso1 floral meristem cells, indicating defects in mitosis and cytokinesis. Our finding that TSO1 is required for organ formation in floral tissues but not in other tissues indicates that TSO1 may encode a floral-specific cell division component, or that TSO1 function is redundant in nonfloral tissues

    CLAVATA3 is a specific regulator of shoot and floral meristem development affecting the same processes as CLAVATA1

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    We have previously described the phenotype of Arabidopsis thaliana plants with mutations at the CLAVATA1 (CLV1) locus (Clark, S. E., Running, M. P. and Meyerowitz, E. M. (1993) Development 119, 397-418). Our investigations demonstrated that clv1 plants develop enlarged vegetative and inflorescence apical meristems, and enlarged and indeterminate floral meristems. Here, we present an analysis of mutations at a separate locus, CLAVATA3(CLV3), that disrupt meristem development in a manner similar to clv1mutations. clv3 plants develop enlarged apical meristems as early as the mature embryo stage. clv3 floral meristems are also enlarged compared with wild type, and maintain a proliferating meristem throughout flower development. clv3 root meristems are unaffected, indicating that CLV3 is a specific regulator of shoot and floral meristem development. We demonstrate that the strong clv3-2 mutant is largely epistatic to clv1 mutants, and that the semi-dominance of clv1 alleles is enhanced by double heterozygosity with clv3 alleles, suggesting that these genes work in the same pathway to control meristem development. We propose that CLV1 and CLV3 are required to promote the differentiation of cells at the shoot and floral meristem

    Interval Running Exercise Reduces Running TIME of 800 Meters Dash Without Causing Increased Level of Sgot – Sgpt in Male Students of the Faculty of Sports Sciences, Manado State University

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    The effort to gain best achievement in sports by means of exercise has twodilemmatic sides, both for the coaches and sport promoters. On one side, exercise shouldbe done intensely and maximally, but on the other side, it is a known fact that excessiveand maximal exercises can damage the body organs. The purposes of this study were toobserve the side effects of interval running exercise of 800 meters, to find out level offatigue by examining lactate acid produced by each model, and to assess the negativeeffects on organs as indicated by the level of SGOT-SGPT. The exercise model appliedin the study comprised interval running of 2 x 800 meters, 4 x 400 meters, 8 x 200meters, 16 x 100 meters and one standard of comparison exercise, which was runningexercise of 2 x 800 meters with passive rest. This study was true experimental usingrandomized pre-test-post-test control group design. Samples of this study were 27 malestudents of the Faculty of Sports Sciences, Manado State University, who were dividedinto five groups. Group 1 was with interval running exercise of 2 x 800 meters. Group 2was assigned to interval running exercise of 4 x 400 meters. Group 3 was with intervalrunning exercise of 8 x 200 meters. Group 4 was with interval running exercise of 16 x100 meters. Group 5 as comparison standard was with running exercise of 2 x 800 meterspassive rest. All the exercise models were carried out for six weeks, each with afrequency of three times a week. Results of the study showed that the five groupsdemonstrated reduction of running time of 800 meters dash (p<0.05), lactate acidproduction differed in some of the groups (p>0.05), levels of SGOT and SGPT of allgroups did not show significant increase (p>0.05). From the above findings, it can beconcluded that all exercise models of interval running 2 x 800 meters, 4 x 400 meters, 8 x200 meters, 16 x 100 meters and 2 x 800 meters with passive rest lowered the runningtime of 800 meters dash and did not increase level of SGOT-SGPT

    Running Boundary Condition

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    In this paper we argue that boundary condition may run with energy scale. As an illustrative example, we consider one-dimensional quantum mechanics for a spinless particle that freely propagates in the bulk yet interacts only at the origin. In this setting we find the renormalization group flow of U(2) family of boundary conditions exactly. We show that the well-known scale-independent subfamily of boundary conditions are realized as fixed points. We also discuss the duality between two distinct boundary conditions from the renormalization group point of view. Generalizations to conformal mechanics and quantum graph are also discussed.Comment: PTPTeX, 21 pages, 8 eps figures; typos corrected, references and an appendix adde

    Inside Front and Back Covers: A Physics of Conducting

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    Running after Diphoton

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    A very plausible explanation for the recently observed diphoton excess at the 13 TeV LHC is a (pseudo)scalar with mass around 750 GeV, which couples to a gluon pair and to a photon pair through loops involving vector-like quarks (VLQs). To accommodate the observed rate, the required Yukawa couplings tend to be large. A large Yukawa coupling would rapidly run up with the scale and quickly reach the perturbativity bound, indicating that new physics, possibly with a strong dynamics origin, is near by. The case becomes stronger especially if the ATLAS observation of a large width persists. In this paper we study the implication on the scale of new physics from the 750 GeV diphoton excess using the method of renormalization group running with careful treatment of different contributions and perturbativity criterion. Our results suggest that the scale of new physics is generically not much larger than the TeV scale, in particular if the width of the hinted (pseudo)scalar is large. Introducing multiple copies of VLQs, lowing the VLQ masses and enlarging VLQ electric charges help reduce the required Yukawa couplings and can push the cutoff scale to higher values. Nevertheless, if the width of the 750 GeV resonance turns out to be larger than about 1 GeV, it is very hard to increase the cutoff scale beyond a few TeVs. This is a strong hint that new particles in addition to the 750 GeV resonance and the vector-like quarks should be around the TeV scale.Comment: 19 pages, 6 figures; v3: corrected Eq.(2.6) and (3.1), updated reference

    Backward running or absence of running from Creutz ratios

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    We extract the running coupling based on Creutz ratios in SU(2) lattice gauge theory with two Dirac fermions in the adjoint representation. Depending on how the extrapolation to zero fermion mass is performed, either backward running or an absence of running is observed at strong bare coupling. This behavior is consistent with other findings which indicate that this theory has an infrared fixed point.Comment: 12 pages, 3 figures; v2 fifth mass point added, three extrapolations now performed, conclusions softene
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