1,107 research outputs found

    Effect of the harvest date, calcium and other chemicals on the quality and storability of ‘Golden Smoothie’ apples

    Get PDF
    Apples cultivated in Mexico generally are smaller and softer than those produced in other geographical latitudes considered as optimal for apple production. The aim of this evaluation was determine the effect of applications with calcium, nitrogen, potassium, magnesium, sulfur and naphthaleneacetic acid (NAA), as well as the harvest date on the quality of apple fruits. ‘Golden Smoothie’ apple trees were treated foliarly with CaCl2 with and without NAA, and with a mixture of N, K, Mg and S or gypsum applied to soil for two years. Apples were harvested at 141 (regular harvest date), 161 (mid-late harvest) and 171 days (late harvest) after full bloom (DAFB) and evaluated for quality at harvest time and during their storage at 0°C for up to 179 days. Foliar applications of CaCl2 significantly increased the calcium content in fruit and leaves, but fruit quality, including firmness, was not influenced. Fertilization of soil with the mixture of nutrients, including CaSO4, did not influence the fruit quality. Lately harvested fruit was 14.9% heavier but 17.1% softer than fruit picked at the commercial harvest date. Delaying of fruit harvest reduced about 43 d the storability of fruit. Based in these results, the relative softness of apples grown in Mexico is not related with its calcium content, hence unlikely to be overcome with the application of this mineral. Even in the control fruits, both seasons, the stored fruits do not show some physiological disorder as bitter pit.  Objective: Apples cultivated in Mexico generally are smaller and softer than those produced in other geographical latitudes considered as optimal for apple production. The aim of this evaluation was determine the effect of applications with calcium, nitrogen, potassium, magnesium, sulfur and naphthaleneacetic acid (NAA), as well as the harvest date on the quality of apple fruits. Methodology ‘Golden Smoothie’ apple trees were treated foliarly with CaCl2 with and without NAA, and with a mixture of N, K, Mg and S or gypsum applied to soil for two years. Apples were harvested at 141 (regular harvest date), 161 (mid-late harvest) and 171 days (late harvest) after full bloom (DAFB) and evaluated for quality at harvest time and during their storage at 0°C for up to 179 days. Results: Foliar applications of CaCl2 significantly increased the calcium content in fruit and leaves, but fruit quality, including firmness, was not influenced. Fertilization of soil with the mixture of nutrients, including CaSO4, did not influence the fruit quality. Lately harvested fruit was 14.9% heavier but 17.1% softer than fruit picked at the commercial harvest date. Delaying of fruit harvest reduced about 43 d the storability of fruit. Based in these results, the relative softness of apples grown in Mexico is not related with its calcium content, hence unlikely to be overcome with the application of this mineral. Conclusions: Even in the control fruits, both seasons, the stored fruits do not show some physiological disorder as bitter pi

    Synthesis and characterization of new aromatic esters based on 4,16-pregnadiene-6,20-dione skeleton

    Get PDF
    A series of new aromatic esters based on 4,16-pregnadiene-6,20-dione skeleton, namely 3ÎČ-benzoyloxy-4,16-pregnadiene-6,20-dione and 3ÎČ-furoyloxy-4,16-pregnadiene- 6,20-dione, which may be good inhibitors for the 5α-reductase enzyme and show high antiandrogenic activity, were synthesized starting from diosgenin. The structures of the steroids were characterized by elemental analysis, 1H NMR, 13C NMR, IR and mass spectrum. Single crystal X-ray diffraction measurement on one of the new compounds, 3ÎČ-(p-methoxybenzoyloxy)-4,16-pregnadiene-6,20-dione revealed that the A, B, C, and D ring adopted half chair, distorted chair, distorted chair, and distorted envelope conformation, respectively. The molecules in the crystal were packed face-to-face at the normal van der Waals distances

    Search for high-mass exclusive γγ → WW and γγ → ZZ production in proton-proton collisions at s \sqrt{s} = 13 TeV

    Get PDF

    Study of dijet events with large rapidity separation in proton-proton collisions at s \sqrt{s} = 2.76 TeV

    Get PDF
    The cross sections for inclusive and Mueller-Navelet dijet production are measured as a function of the rapidity separation between the jets in proton-proton collisions at s√ = 2.76 TeV for jets with transverse momentum pT > 35 GeV and rapidity |y| 20 GeV is introduced to improve the sensitivity to the effects of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution. The measurement is compared with the predictions of various Monte Carlo models based on leading-order and next-to-leading-order calculations including the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi leading-logarithm (LL) parton shower as well as the LL BFKL resummation

    Search for heavy resonances decaying to Z(ΜΜˉ\bar{Îœ}) V(qqˉ\bar{q}â€Č) in proton-proton collisions at √s = 13 TeV

    Get PDF

    A search for new physics in central exclusive production using the missing mass technique with the CMS detector and the CMS-TOTEM precision proton spectrometer

    Get PDF
    A generic search is presented for the associated production of a Z boson or a photon with an additional unspecified massive particle X, pp → pp + Z/γ + X, in proton-tagged events from proton–proton collisions at √s = 13 TeV, recorded in 2017 with the CMS detector and the CMS-TOTEM precision proton spectrometer. The missing mass spectrum is analysed in the 600–1600 GeV range and a fit is performed to search for possible deviations from the background expectation. No significant excess in data with respect to the background predictions has been observed. odelindependent upper limits on the visible production cross section of pp → pp + Z/γ + X are set

    Measurement of the top quark mass using events with a single reconstructed top quark in pp collisions at s\sqrt{s} = 13 TeV

    Get PDF
    A measurement of the top quark mass is performed using a data sample enriched with single top quark events produced in the t channel. The study is based on proton- proton collision data, corresponding to an integrated luminosity of 35.9 fb−1^{-1}, recorded at s\sqrt{s} = 13 TeV by the CMS experiment at the LHC in 2016. Candidate events are selected by requiring an isolated high-momentum lepton (muon or electron) and exactly two jets, of which one is identified as originating from a bottom quark. Multivariate discriminants are designed to separate the signal from the background. Optimized thresholds are placed on the discriminant outputs to obtain an event sample with high signal purity. The top quark mass is found to be 172.13+0.76^{+0.76}−0.77_{-0.77} GeV, where the uncertainty includes both the statistical and systematic components, reaching sub-GeV precision for the first time in this event topology. The masses of the top quark and antiquark are also determined separately using the lepton charge in the final state, from which the mass ratio and difference are determined to be 0.9952+0.0079^{+0.0079}−0.0104_{-0.0104} and 0.83+1.79^{+1.79}−1.35_{-1.35} GeV, respectively. The results are consistent with CPT invariance

    Inclusive nonresonant multilepton probes of new phenomena at s\sqrt{s}= 13 TeV

    Get PDF
    An inclusive search for nonresonant signatures of beyond the standard model (SM) phenomena in events with three or more charged leptons, including hadronically decaying τ leptons, is presented. The analysis is based on a data sample corresponding to an integrated luminosity of 138 fb−1^{-1} of proton-proton collisions at s\sqrt{s}= 13 TeV collected by the CMS experiment at the LHC in 2016–2018. Events are categorized based on the lepton and b-tagged jet multiplicities and various kinematic variables. Three scenarios of physics beyond the SM are probed, and signal-specific boosted decision trees are used for enhancing sensitivity. No significant deviations from the background expectations are observed. Lower limits are set at 95% confidence level on the mass of type-III seesaw heavy fermions in the range 845–1065 GeV for various decay branching fraction combinations to SM leptons. Doublet and singlet vectorlike τ lepton extensions of the SM are excluded for masses below 1045 GeV and in the mass range 125–150 GeV, respectively. Scalar leptoquarks decaying exclusively to a top quark and a lepton are excluded below 1.12–1.42 TeV, depending on the lepton flavor. For the type-III seesaw as well as the vectorlike doublet model, these constraints are the most stringent to date. For the vectorlike singlet model, these are the first constraints from the LHC experiments. Detailed results are also presented to facilitate alternative theoretical interpretations

    Search for long-lived heavy neutral leptons with displaced vertices in proton-proton collisions at s \sqrt{\mathrm{s}} =13 TeV

    Get PDF

    Measurement of W±^{±}γ differential cross sections in proton-proton collisions at s\sqrt{s} = 13 TeV and effective field theory constraints

    Get PDF
    Differential cross section measurements of W±γ production in proton-proton collisions at s\sqrt{s} =13  TeV are presented. The data set used in this study was collected with the CMS detector at the CERN LHC in 2016–2018 with an integrated luminosity of 138  fb−1. Candidate events containing an electron or muon, a photon, and missing transverse momentum are selected. The measurements are compared with standard model predictions computed at next-to-leading and next-to-next-to-leading orders in perturbative quantum chromodynamics. Constraints on the presence of TeV-scale new physics affecting the WWÎł vertex are determined within an effective field theory framework, focusing on the O3W operator. A simultaneous measurement of the photon transverse momentum and the azimuthal angle of the charged lepton in a special reference frame is performed. This two-dimensional approach provides up to a factor of ten more sensitivity to the interference between the standard model and the O3W contribution than using the transverse momentum alone
    • 

    corecore