Nitrous oxide emissions from soils under sugarcane fields in the Cerrado.

Soil fertilization with mineral nitrogen and organic fertilizers, such as the vinasse ? a liquid waste from bio-ethanol production, is a common practice on the sugarcane produced in Brazil that can lead to increasing emissions of greenhouse gases. Nitrous oxide (N2O) is a greenhouse gas even more harmful than the carbon dioxide (CO2), and has longer residence time in the atmosphere. The present study has been conducted on a sugarcane irrigated experiment established at the EMBRAPA Cerrados research station, in Brazil. We hypothesized that N2O emissions would be higher in the sugarcane fields, especially in the fertilized areas that combined mineral nitrogen (N) and vinasse (V), than in the native vegetation remnants (Cerrado); and that irrigated soils would have the highest fluxes of N2O. First measurements were done after the application of N and vinasse in May 2014 until June 2014 as an intensive campaign, and continuous monitoring have been conducted so far. Preliminary results showed that higher emissions occurred on soils combining N and V, showing fluxes that were twice as higher than the fluxes from other treatments, and 100 times bigger than fluxes from soils with native vegetation (469±158, 62.3±6.9, and 0.8±0.1 for V+N, N and Cerrado areas, respectively). The present study is pioneer in the Cerrado region and data are important to assess the regional variations on the N2O fluxes in Brazil, to reduce the bias on national estimations of N2O emissions, and to find more sustainable solutions for the production of bio-ethanol from sugarcane

Issues on Generating Primordial Anisotropies at the End of Inflation

We revisit the idea of generating primordial anisotropies at the end of inflation in models of inflation with gauge fields. To be specific we consider the charged hybrid inflation model where the waterfall field is charged under a U(1) gauge field so the surface of end of inflation is controlled both by inflaton and the gauge fields. Using delta N formalism properly we find that the anisotropies generated at the end of inflation from the gauge field fluctuations are exponentially suppressed on cosmological scales. This is because the gauge field evolves exponentially during inflation while in order to generate appreciable anisotropies at the end of inflation the spectator gauge field has to be frozen and scale invariant. We argue that this is a generic feature, that is, one can not generate observable anisotropies at the end of inflation within an FRW background.Comment: V3: new references added, JCAP published versio

Construção de um mapa genético para o feijão usando marcadores SNP e a população de RILs Rudá x AND 277.

O principal objetivo deste trabalho foi construir um mapa genético robusto para o feijoeiro-comum usando 376 RILs Rudá x AND 277 e 5.398 marcadores SNP (BARBean6K_3 Illumina BeadChip).CONAF

Supersymmetric mass spectra and the seesaw type-I scale

We calculate supersymmetric mass spectra with cMSSM boundary conditions and a type-I seesaw mechanism added to explain current neutrino data. Using published, estimated errors on SUSY mass observables for a combined LHC+ILC analysis, we perform a theoretical $\chi^2$ analysis to identify parameter regions where pure cMSSM and cMSSM plus seesaw type-I might be distinguishable with LHC+ILC data. The most important observables are determined to be the (left) smuon and selectron masses and the splitting between them, respectively. Splitting in the (left) smuon and selectrons is tiny in most of cMSSM parameter space, but can be quite sizeable for large values of the seesaw scale, $m_{SS}$. Thus, for very roughly $m_{SS} \ge 10^{14}$ GeV hints for type-I seesaw might appear in SUSY mass measurements. Since our numerical results depend sensitively on forecasted error bars, we discuss in some detail the accuracies, which need to be achieved, before a realistic analysis searching for signs of type-I seesaw in SUSY spectra can be carried out.Comment: 17 pages, 7 figure

Evolution of fNL to the adiabatic limit

We study inflationary perturbations in multiple-field models, for which zeta typically evolves until all isocurvature modes decay--the "adiabatic limit". We use numerical methods to explore the sensitivity of the nonlinear parameter fNL to the process by which this limit is achieved, finding an appreciable dependence on model-specific data such as the time at which slow-roll breaks down or the timescale of reheating. In models with a sum-separable potential where the isocurvature modes decay before the end of the slow-roll phase we give an analytic criterion for the asymptotic value of fNL to be large. Other examples can be constructed using a waterfall field to terminate inflation while fNL is transiently large, caused by descent from a ridge or convergence into a valley. We show that these two types of evolution are distinguished by the sign of the bispectrum, and give approximate expressions for the peak fNL.Comment: v1: 25 pages, plus Appendix and bibliography, 6 figures. v2: minor edits to match published version in JCA

Dark matter scenarios in the minimal SUSY B-L model

We perform a study of the dark matter candidates of a constrained version of the minimal R-parity-conserving supersymmetric model with a gauged $U(1)_{B-L}$. It turns out that there are four additional candidates for dark matter in comparison to the MSSM: two kinds of neutralino, which either correspond to the gaugino of the $U(1)_{B-L}$ or to a fermionic bilepton, as well as "right-handed" CP-even and -odd sneutrinos. The correct dark matter relic density of the neutralinos can be obtained due to different mechanisms including new co-annihilation regions and resonances. The large additional Yukawa couplings required to break the $U(1)_{B-L}$ radiatively often lead to large annihilation cross sections for the sneutrinos. The correct treatment of gauge kinetic mixing is crucial to the success of some scenarios. All candidates are consistent with the exclusion limits of Xenon100.Comment: 45 pages, 22 figures; v2: extended discussion of direct detection cross section, matches published versio