Effect of the Amount and Timing of Ammonium Sulfate Single Top-dressing Application on Growth and Yield of Akitakomachi Rice (Oryza sativa L.)

The effect of the amount and the timing of single top-dressing application of Ammonium sulfate fertilizer on the growth and yield of Akitakomachi rice (Oryza sativa L.) was investigated in this study. Two amounts (20kg.ha-1 and 50kg.ha-1) of Ammonium sulfate ((NH4)2SO4) fertilizer were applied at three timings;14 days after transplanting, panicle initiation, and flowering respectively, giving six treatments (14DAT:20, 14DAT:50, PI:20, PI:50, FL:20 & FL:50). A Randomized Complete Block Design (RCBD) with three replications was used. Growth data were collected on plant length, number of tillers and leaf color, and calculated yield and yield components were determined. Plant length was significantly higher in 14DAT:50 and PI:50, and lowest in FL:20 and FL:50. Tiller number was higher in 14DAT:50 compared to the other treatments. 14DAT:50 and PI:50 produced the highest number of panicles per m2. PI:20 and PI:50 had the highest number of spikelets per panicle. The 1000 grains weight was highest in PI:50 and lowest in 14DAT:50. The highest yields were obtained in 14DAT:50 and PI:50, while FL:20 and FL:50 produced the lowest yields. The results showed that for nitrogen (N) single top-dressing application, high amounts increase both the plant growth and the grain yield if the application is done at vegetative stage or at panicle initiation stage. However, if the nitrogen (N) amount is too high, there exist the risk that the plants may lodge.

Carbon Finance and Emission Trading in Mexico: Building Lessons from the CDM Experience and FOMECAR (Mexican Carbon Fund)

A more general lesson from the past decade is that climate policy and carbon initiatives such as ETS and carbon pricing are not static concepts, but are instead constantly evolving and building upon previous experiences. The vision of a single, top-down global trading system has shifted toward the reality of various single and regional trading system programmes. Building a national emission trading system in Mexico will surely pass through processes and experiences that the country has somehow undertaken from the Kyoto Protocol (KP) in 2005, particularly with the Clean Development Mechanism (CDM), the Mexican Carbon Fund (FOMECAR) and their legacy. Additional design elements or provisions must be prepared under the new ETS in Mexico: regulation will possibly include definitions, scope, compliance obligation, legal procedures and other necessary provisions such as the allocation of permits. However, in order to start the process, important questions on financing the initiative and accompanying the development of an ETS will go through a finance support scenario. Thus, who is going to finance the starting process for allocating emissions, financing bonds and other design issues for the implementation of the Mexican ETS? Who will be financing and offering technical cooperation to follow up on eligible projects for the ETS and who will be supporting education and information activities about ETS implementation? Those and other questions will be addressed in this article, in the light of international and regional experiences.

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

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, recorded at $$ \sqrt{s} $$ 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 $$ {172.13}_{-0.77}^{+0.76} $$ 172.13 − 0.77 + 0.76 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 $$ {0.9952}_{-0.0104}^{+0.0079} $$ 0.9952 − 0.0104 + 0.0079 and $$ {0.83}_{-1.35}^{+1.79} $$ 0.83 − 1.35 + 1.79 GeV, respectively. The results are consistent with CPT invariance.

On non-factorisable contributions to t-channel single-top production

We compute the non-factorisable contribution to the two-loop helicity amplitude for t-channel single-top production, the last missing piece of the two-loop virtual corrections to this process. Our calculation employs analytic reduction to master integrals and the auxiliary mass flow method for their fast numerical evaluation. We study the impact of these corrections on basic observables that are measured experimentally in the single-top production process.

Observation of tW production in the single-lepton channel in pp collisions at $$ \sqrt{s} $$ = 13 TeV

A measurement of the cross section of the associated production of a single top quark and a W boson in final states with a muon or electron and jets in proton-proton collisions at $$ \sqrt{s} $$ s = 13 TeV is presented. The data correspond to an integrated luminosity of 36 fb−1 collected with the CMS detector at the CERN LHC in 2016. A boosted decision tree is used to separate the tW signal from the dominant t$$ \overline{\mathrm{t}} $$ t ¯ background, whilst the subleading W+jets and multijet backgrounds are constrained using data-based estimates. This result is the first observation of the tW process in final states containing a muon or electron and jets, with a significance exceeding 5 standard deviations. The cross section is determined to be 89 ± 4 (stat) ± 12 (syst) pb, consistent with the standard model.

Search for dark matter produced in association with a single top quark in $$\sqrt{s}=13$$ TeV $$pp$$ collisions with the ATLAS detector

This paper presents a search for dark matter in the context of a two-Higgs-doublet model together with an additional pseudoscalar mediator, a, which decays into the dark-matter particles. Processes where the pseudoscalar mediator is produced in association with a single top quark in the 2HDM+a model are explored for the first time at the LHC. Several final states which include either one or two charged leptons (electrons or muons) and a significant amount of missing transverse momentum are considered. The analysis is based on proton–proton collision data collected with the ATLAS experiment at $$\sqrt{s} = 13$$ s = 13 TeV during LHC Run 2 (2015–2018), corresponding to an integrated luminosity of 139 $$\hbox {fb}^{-1}$$ fb - 1 . No significant excess above the Standard Model predictions is found. The results are expressed as 95% confidence-level limits on the parameters of the signal models considered.