Enhancing genomic prediction with stacking ensemble learning in arabica coffee.

Coffee Breeding programs have traditionally relied on observing plant characteristics over years, a slow and costly process. Genomic selection (GS) offers a DNA-based alternative for faster selection of superior cultivars. Stacking Ensemble Learning (SEL) combines multiple models for potentially even more accurate selection. This study explores SEL potential in coffee breeding, aiming to improve prediction accuracy for important traits [yield (YL), total number of the fruits (NF), leaf miner infestation (LM), and cercosporiosis incidence (Cer)] in Coffea Arabica. We analyzed data from 195 individuals genotyped for 21,211 single-nucleotide polymorphism (SNP) markers. To comprehensively assess model performance, we employed a cross-validation (CV) scheme. Genomic Best Linear Unbiased Prediction (GBLUP), multivariate adaptive regression splines (MARS), Quantile Random Forest (QRF), and Random Forest (RF) served as base learners. For the meta-learner within the SEL framework, various options were explored, including Ridge Regression, RF, GBLUP, and Single Average. The SEL method was able to predict the predictive ability (PA) of important traits in Coffea Arabica. SEL presented higher PA compared with those obtained for all base learner methods. The gains in PA in relation to GBLUP were 87.44% (the ratio between the PA obtained from best Stacking model and the GBLUP), 37.83%, 199.82%, and 14.59% for YL, NF, LM and Cer, respectively. Overall, SEL presents a promising approach for GS. By combining predictions from multiple models, SEL can potentially enhance the PA of GS for complex traits

Economic Feasibility Study of Photovoltaic Panels Installation by PVsyst 6.73 Simulator

The increasing pursuit of industry modernization presenting efficiency gains, productivity and cost reduction raises the discussion about the use of new technologies that promote, simultaneously, business sustainability and productive and economic efficiency for offshore companies, which operates in the Campos Basin, located at the municipality of Macaé, Rio de Janeiro State, Brazil. This paper presents an economic feasibility evaluation to use photovoltaic panels in order to measure the project costs and highlight its benefits; to this end, a local supplier was contacted to estimate a budget. The author ran the PVsyst 6.73 simulator to calculate the energy produced by the photovoltaic system and other parameters. Taking into account the Minimum Attractive Rate (MAR) of 8,3 percent, established by the board of directors, the results, by the Simple Payback and Discounted Payback (SPDP); Profitability Index (PI); Return on Investment (ROI); Net Present Value (NPV); and Internal Rate of Return (IRR) methods applied, proved the project is economically feasible and that this company has physical structure to install the equipment. As such, it is possible to have a great medium-and long-term financial economy, contributing to produce clean energy in the country

The solar wind in time – II. 3D stellar wind structure and radio emission

In this work, we simulate the evolution of the solar wind along its main-sequence lifetime and compute its thermal radio emission. To study the evolution of the solar wind, we use a sample of solar mass stars at different ages. All these stars have observationally reconstructed magnetic maps, which are incorporated in our 3D magnetohydrodynamic simulations of their winds. We show that angular-momentum loss and mass-loss rates decrease steadily on evolutionary time-scales, although they can vary in a magnetic cycle time-scale. Stellar winds are known to emit radiation in the form of thermal bremsstrahlung in the radio spectrum. To calculate the expected radio fluxes from these winds, we solve the radiative transfer equation numerically from first principles. We compute continuum spectra across the frequency range 100 MHz to 100 GHz and find maximum radio flux densities ranging from 0.05 to 2.2 μJy. At a frequency of 1 GHz and a normalized distance of d = 10 pc, the radio flux density follows 0.24 (Ω/Ω☉)0.9 (d/[10pc])-2μJy, where Ω is the rotation rate. This means that the best candidates for stellar wind observations in the radio regime are faster rotators within distances of 10 pc, such as κ1 Ceti (0.73 μJy) and χ1 Ori (2.2 μJy). These flux predictions provide a guide to observing solar-type stars across the frequency range 0.1-100 GHz in the future using the next generation of radio telescopes, such as ngVLA and Square Kilometre Array

A transformação do espaço amazônico e seus reflexos na condição atual da cobertura e uso da terra.

A Amazônia passou ao longo de sua história, por um intenso processo de transformação na sua forma e no seu conteúdo, fazendo com que diferentes elementos sociais, políticos e econômicos atuassem na transformação do seu espaço. Sendo assim, através da interpretação do atual uso e cobertura da terra, é possível verificar como os diferentes atores e políticas envolvidas se associaram em cada momento específico na história e atualmente refletem no espaço. Fazendo uso desta interpretação pretende-se abordar esses elementos e sua correspondente natureza transformada para buscar estabelecer os pontos de apoio nesta leitura para o processo de desflorestamento que a Amazônia sofreu nos últimos quarenta anos e no que estas áreas se transformaram

Some applications of excited-state-excited-state transition densities

We derive an approximation for transition moments between excited states consistent with the approximations and assumptions normally used to obtain transition moments betwen the ground and excited states in the random-phase approximation and its higher-order approximations. We apply the result to the calculation of the photoionization cross sections of the 23S and 21S metastable states of helium by a numerical analytical continuation of the frequency-dependent polarizability. The procedure completely avoids the need for continuum basis functions. The cross sections agree well with the results of other calculations. We also predict an accurate two-photon decay rate for the 21S metastable state of helium. The entire procedure is immediately applicable to several problems involving photoionization of metastable states of molecules

Produção de sementes, qualidade fisiológica e identificação de genótipos de alface termotolerantes.

O objetivo neste trabalho foi identificar as diferenças de germinação de sementes de vinte cultivares de alface em condições de temperatura ideal 20° C