Influence of boron on growth and mineral composition of bean (Phaseolus vulgaris L.)

Nine cultivars of Phaseolus vulgaris L. were grown in nutrient solution to study the effect of boron on growth and mineral composition. Data obtained in thie study allowed for the following conclusions: (1) high levels of boron affected plant height, root length, dry weight of tops, dry weight of root, and total dry weight; (2) regression analysis was used to point out differential behaviour among cultivars in relation to boron concentration in nutrient solution; (3) the best mineral concentration in the plant tissue was obtained with application of 0,5 ppm of boron in the nutrient solution.O desenvolvimento do feijoeiro (Phaseolus vulgaris L.) foi estudado observando neve cultivares em solução nutritiva. Equações de regressão da matéria seca permitiram conhecer a resposta diferencial dos cultivares em relação ao boro. Análises minerais da matéria seca foram realizadas com o objetivo de conhecer o efeito de doses crescentes de boro no estado nutricional do feijoeiro

Aproveitamento de um fosfato natural parcialmente solubilizado pelo sorgo sacarino em condições de casa de vegetação: I. Latossolo vermelho amarelo

The usefulness of a rock phosphat from Araxá, MG, Brasil, partially acidulated with sulfuric acid (FAPS) was studied, rock phosphate (FA), gafsa phosphate (FG), and simple superphosphate (SPS) being used for comparison. There successive crops were employed in order to assess the residual value, both in presence an in the absence of liming. The analyses of data obtained allowed for the following conclusions to be drawn: the efficiency of FAPS in relation to that of SPS decreased from the first to the third crop, reaching 70% as general ave rage; in the presence of liming, however, the efficiency did not decrease so much, 80-90% being obtained; FG gave results equivalent to those obtained with SPS; liming decreased the relative efficiency of the rock phosphates, especially that of FA which fell from circa 50% to 40%; available P content in the soil was increased as consequence of varions treatments including FAPS plus lime; FAPS acted as a source of P, Ca, and S; its performance in closer to that of SPS than to that of the original FA.Foi estudado o aproveitamento do fosfato de Araxá parcialmente solubilizado com ácido sulfúrico (FAPS) em comparação com o concentrado fosfático de Araxá (FA), com o fosfato deGafsa (FG) e com o superfosfato simples SPS. Empregou-se um LVA de textura média de Anhembi, SP. Foram feitos três cultivos sucessivos sem readubação fosfatada, em presença e ausência de calagem inicial. A análise dos dados permitiu tirar as conclusões principais: a eficiência do FAPS em relação à do SPS diminuiu do primeiro para o terceiro, atingindo em média 70%; o FG deu resultados equivalentes e o FA garantiu cerca de 50%, da produção de matéria seca; em presença de calagem, entretanto, aumentou a eficiência relativa do FAPS (80-90%) e caiu a do FA (40%); o teor de P disponível no solo aumentou com a calagem quando se usou FAPS; a análise das plantas mostrou que o FAPS funcionou como fonte de P, Ca e S; o comportamento do produto se aproxima mais daquele do SPS do que o FA original

Aproveitamento pelo feijoeiro de um fosfato natural parcialmente solubilizado: I. Estudos em casa de vegetação com um latossolo vermelho amarelo

The response of beans to a partially acidulated (50% sulfuric acid) rock phosphate (FAPS) was studied under greenhouse conditions. Simple superphosphate (SPS), the original rock phosphate (FA), and Gafsa rock phosphate (FG) were used for comparison. The soil was acidic and low in available P. Three successive crops were made to evaluate the residual effects both in presence and in absence of initial liming. Main conclusions were as following. Giving to the dry matter yield obtained with powder SPS the relative value of 100 the efficiency of the other P2O5 sources was: (1) in the absence of liming - granulate SPS = 80 FA = 85, FAPS = 75 to 90 (depending of the granule size), FG = 150; (2) in th, e presence of liming - granulate SPS = 98, FA = 66 FAPS = 70 to 85 FG = 110 Liming increase the uptake of P from all sources. FAPS served as source of Ca and S as well. After the third crop the available (01sen) P content obeyed the following decreasing order: SPS, FG, FAPS, and Fa. Respective of source the P content was lower when lime had been applied.Foi estudado o aproveitamento do fosfato de Araxá parcialmente solubilizado com ácido sulfúrico (FAPS) em comparação com o do concentrado fosfático de Araxá (FA) , do fosfato de Gafsa (FG) e com o do superfosfato simples (SPS). O solo utilizado foi um Latossolo Vermelho Amarelo, textura média (Haplorthox, LVA) de Anhembi, S. Paulo, ácido e pobre em P. Foram feitos três cultivos sucessivos, sem readubação fosfatada, em presença e ausência de calagem inicial. A análise dos dados permitiu tirar as seguintes conclusões principais com respeito às produções obtidas nos três cultivos em conjunto, considerando-se como 100 a matéria seca correspondente ao SPS em pó: (l) em ausência de calagem - SPS granulado = 80, FA = 85, FAPS = 75 a 90 (dependendo da granulometria), FG = 150; (2) em presença de calagem - SPS granulado = 98 , FA = 66, FAPS = 70 a 85, FG = 110. A calagem aumentou a absorção do P de todas as fontes, tendo o FAPS funcionado também como fornecedor de Ca e de S. Depois do terceiro cultivo o teor de P disponível no solo (01 sen) obedeceu a seguinte ordem decrescente: SPS, FG, FAPS e FA. Os teores, independentemente das fontes, foram sempre menores quando a calagem fora feita

Aproveitamento de um fosfato natural parcialmente solubilizado pelo sorgo sacarino em condições de casa de vegetação: II. Latossolo vermelho escuro

The response of sweet sorghum to a partially acidulated (with sulfuric acid) rock phosphate (FAPS) was studied using the original ground phosphate (FA), Gafsa rock phosphate (FG) and simple superphosphate (SPS) for comparison. The soil, a Dark Red Latosol (LE, Haplorthox) was collected in Botucatu, SP. Three successive crops were conducted without new applications of P sources, both in the presence and in the absence of initial liming. The analyses of the data obtained allowed for the following conclusions to be drawn: in the three successive crops combined, dry matter production in the presence of FAPS and no lime applied was 71% of that obtained when powder SPS was used; the efficiency of FA was 17%, where as that of PG was 150%; In the presence of liming,, however, the following values were obtained: granulated SPS - 89%; FAPS - 98%; FA = 30%; FG = 83%. Liming increased the uptake of P from powder SPS, FA and FAPS. FAPS acted also as source of Ca and S. After the third crop, in the absence of liming, SPS left In the soil the highest concentration of available P (Olsen), being followed by FG, FAPS and FA. Liming, however, decreased the amount of residual available P due to SPS, FA, and FG. In the whole the behaviour of FAPS was more similar to that of SPS than to the effect of PA.Foi estudado o aproveitamento do fosfato de Araxá parcialmente solubilizado com ácido sulfúrico (FAPS) em comparação com o concentrado fosfático de Araxá (FA), com o fosfato de Gafsa (FG) e com o superfosfato simples (SPS). O solo utilizado foi um Latossolo Vermelho Escuro, textura média (Haplorthox) de Botucatu, SP. Foram feitos três cultivos sucessivos, sem readubação fosfatada, em presença e ausência de calagem inicial. A análise dos dados permitiu tirar as seguintes conclusões principais: em ausência de calagem e produção de matéria seca nos três cultivos conseguida com o FAPS foi 71% da obtida com o SPS em pó; a eficiência relativa do FA foi de 17% e a do FG superou a do SPS em 50%; fazendo-se a calagem a eficiência relativa das fontes (100 = SPS em pó) foi: SPS granulado = 89%, FAPS = 98%, FA 30%, FG = 83%. A calagem aumentou a absorção de P do SPS em pó, do FA e do FAPS. 0 FAPS funcionou também como fonte de Ca e de S. Depois do terceiro cultivo, em ausência de calagem, o SPS deixou no solo o maior teor de P disponível (Olsen), seguindo-se o FG, o FAPS e o FA; a calagem reduziu os teores finais de P disponível no solo quando as fontes foram o SPS, o FA e o FG. De um modo geral o comportamento do FAPS foi mais semelhante ao do SPS que ao do FA

Investigating the Correlation between Performance Scores and Energy Consumption of Mobile Web Apps

Context. Developers have access to tools like Google Lighthouse to assess the performance of web apps and to guide the adoption of development best practices. However, when it comes to energy consumption of mobile web apps, these tools seem to be lacking. Goal. This study investigates on the correlation between the performance scores produced by Lighthouse and the energy consumption of mobile web apps. Method. We design and conduct an empirical experiment where 21 real mobile web apps are (i) analyzed via the Lighthouse performance analysis tool and (ii) measured on an Android device running a software-based energy profiler. Then, we statistically assess how energy consumption correlates with the obtained performance scores and carry out an effect size estimation. Results. We discover a statistically significant negative correlation between performance scores and the energy consumption of mobile web apps (with medium to large effect sizes), implying that an increase of the performance score tend to lead to a decrease of energy consumption. Conclusions. We recommend developers to strive to improve the performance level of their mobile web apps, as this can also have a positive impact on their energy consumption on Android devices

Discovering planets with PLATO: Comparison of algorithms for stellar activity filtering

Context. To date, stellar activity is one of the main limitations in detecting small exoplanets via transit photometry. Since this activity is enhanced in young stars, traditional filtering algorithms may severely under-perform in detecting such exoplanets. Aims.This paper aims to compare the relative performances of four algorithms developed by independent research groups specifically for the filtering of activity in the light curves (LCs) of young active stars, prior to the search for planetary transit signals: Notch and LOCoR(N&L), Young Stars Detrending(YSD), K2 Systematics Correction(K2SC) and VARLET. We include in the comparison also the two best-performing algorithms implemented in Wotan, namely the Tukey's biweight and the Huber Spline. Methods. We performed a series of injection-retrieval tests of planetary transits of different types, from Jupiter down to Earth-sized planets, moving both on circular and eccentric orbits. The tests were carried out over 100 simulated LCs of both quiet and active solar-like stars that will be observed by the ESA space telescope PLATO. Results. We found that N&L is the best choice in many cases, since it misses the lowest number of transits. However, it under-performs if the planetary orbital period closely matches the stellar rotation period, especially in the case of small planets for which the biweight and VARLET algorithms work better. For LCs with a large number of data, the combined results of YSD and Huber Spline yield the highest recovery percentage. Filtering algorithms allow us to get a very precise estimate of the orbital period and the mid-transit time of the detected planets, while the planet-to-star radius is under-estimated most of the time, especially in the case of grazing transits or eccentric orbits. A refined filtering taking into account the presence of the planet is compulsory for a proper planetary characterization.Comment: 25 pages, accepted for publication by A&

Deficiências de macronutrientes na sota (Glycine max L., Merril, var. IAC-2)

Sintomas de deficiência de macronutrientes foram induzidos na soja, var. IAC-2. Foi verificado o efeito da omissão de N, R, K, Ca, Mg e S no crescimento, produção e composição mineral das folhas.Soybean plants, var. IAC-2 were grown in nutrient solution in presence and absence of macronutrients whose symptoms of deficiency were induced. The main conclusions are as follws : 1) The symptoms of deficiency herein obtained follow the general pattern as found in other plants; 2) growth and yield were drastically reduced by absence of N and Ca from the substrate; 3) omission of on element caused a decrease in its content in the leaves down to deficiency levels, except in the case of S

Multiple stellar populations in the Galactic globular cluster NGC 6752

We have carried out high-precision photometry on a large number of archival HST images of the Galactic globular cluster NGC 6752, to search for signs of multiple stellar populations. We find a broadened main sequence, and demonstrate that this broadening cannot be attributed either to binaries or to photometric errors. There is also some indication of a main-sequence split. No significant spread could be found along the subgiant branch, however. Ground-based photometry reveals that in the U vs. (U-B) color-magnitude diagram the red-giant branch exhibits a clear color spread, which we have been able to correlate with variations in Na and O abundances. In particular the Na-rich, O-poor stars identified by Carretta et al. (2007) define a sequence on the red side of the red-giant branch, while Na-poor, O-rich stars populate a bluer, more dispersed portion of the red-giant branch.Comment: 31 pages, 12 figures; Accepted for Publication in the Astrophysical Journa

HADES RV Programme with HARPS-N at TNG. VII. Rotation and activity of M-Dwarfs from time-series high-resolution spectroscopy of chromospheric indicators

We aim to investigate the presence of signatures of magnetic cycles and rotation on a sample of 71 early M-dwarfs from the HADES RV programme using high-resolution time-series spectroscopy of the Ca II H & K and Halpha chromospheric activity indicators, the radial velocity series, the parameters of the cross correlation function and the V-band photometry. We used mainly HARPS-N spectra, acquired over four years, and add HARPS spectra from the public ESO database and ASAS photometry light-curves as support data, extending the baseline of the observations of some stars up to 12 years. We provide log(R'hk) measurements for all the stars in the sample, cycle length measurements for 13 stars, rotation periods for 33 stars and we are able to measure the semi-amplitude of the radial velocity signal induced by rotation in 16 stars. We complement our work with previous results and confirm and refine the previously reported relationships between the mean level of chromospheric emission, measured by the log(R'hk), with the rotation period, and with the measured semi-amplitude of the activity induced radial velocity signal for early M-dwarfs. We searched for a possible relation between the measured rotation periods and the lengths of the magnetic cycle, finding a weak correlation between both quantities. Using previous v sin i measurements we estimated the inclinations of the star's poles to the line of sight for all the stars in the sample, and estimate the range of masses of the planets GJ 3998 b and c (2.5 - 4.9 Mearth and 6.3 - 12.5 Mearth), GJ 625 b (2.82 Mearth), GJ 3942 b (7.1 - 10.0 Mearth) and GJ 15A b (3.1 - 3.3 Mearth), assuming their orbits are coplanar with the stellar rotation.Comment: 19 pages, 16 figures, 10 table