Avaliação de um modelo de parcela com fertilizante-15N na determinação do aproveitamento do nitrogênio do fertilizante por cana-de-açúcar

Two experiments were conducted on commercial sugar cane fields cropped with the variety SP70-1143, with the objective of evaluating a single row microplot design to determine plant recovery of 15N fertilizer nitrogen. One of them used 15N-aqua ammonia and 15N-urea applied to two linear meter microplots of a ratoon crop (four replicates). The second used one linear meter microplots (three replicates) which received 15N-aqua ammonia only. The fertilizers were applied on 15cm deep furrows, located 25cm from both sides of the cane row. One linear meter of ratoon cane, inside and outside of the microplot, and on the same and adjacent rows were harvested twelve months after fertilization. The results indicate the feasibility of using single row segments of ratoon cane with 15N-fertilizer. The main advantage of this microplot design, when compared to the classical 3 contiguous row segments, is that only one third of the labeled fertilizer is needed. In a single row, in order to separate the nitrogen taken up by plants from the fertilizer applied to the row (Nr dff r), from that applied to adjacent rows (Nr dff r+1, and Nr dff r-1), the following should be considered: (a) a border segment of 0.5 to 1.0m inside the plot, so that Ndff results from plants harvested in the center of the microplot represent the actual value of fertilizer nitrogen taken up from that applied to the same row, and (b) harvest of plants from adjacent rows at equivalent positions to those sampled inside the microplot, to quantify the 15N-fertilizer uptake by outside plants (Nr+1dff r and Nr-1dff r), which is assumed to be the same as non labeled fertilizer applied to adjacent rows (Nr dff r+l and Nr dff r-1) taken up by inside plants. The Ndff total values should be calculated by the equation: Ndff total = Nr dff r + Nr+1dff r + Nr-1dff r.Com o objetivo de avaliar um modelo de parcela, na determinação do aproveitamento pela cana-de-açúcar de fertilizantes nitrogenados-15N, foram conduzidos dois experimentos em áreas comerciais plantadas com a variedade SP 70-1143. Num experimento foram aplicados os adubos aquamônia-15N e uréia-15N, em parcelas constituídas de segmentos simples de linha de soqueira de cana, com 2 metros lineares de comprimento (4 repetições). No segundo, parcelas de l metro linear (3 repetições) receberam aquamônia-15N. Os fertilizantes foram aplicados em sulcos com 15cm de profundidade, abertos a 25cm de distância nos dois lados da linha de cana. Foram realizadas colheitas de l metro linear de cana no interior e fora das parcelas, na mesma linha e nas adjacentes à elas. Os resultados isotópicos evidenciaram ser perfeitamente possível a utilização dessas parcelas com fertilizante-15N. A principal vantagem do modelo, comparado às parcelas convencionais com 3 segmentos contíguos, é a redução a um terço, da quantidade de fertilizantes-15N necessária. Na determinação do nitrogênio absorvido pelas plantas do fertilizante aplicado na linha com adubo-15N (Nr dff r), e daquele absorvido do fertilizante não marcado com o isótopo, aplicado nas linhas adjacentes (Nr dff r+1 e Nr dff r-1), deve-se considerar para as parcelas em questão: (a) bordadura interna de 0,5 a 1m de comprimento, para que os valores de Ndff de plantas colhidas no centro delas, representem o valor máximo do nitrogênio absorvido do fertilizante aplicado na linha; e (b) colheita de plantas nas linhas imediatamente adjacentes, em posições equivalentes à efetuada no interior das parcelas, a fim de quantificar o N absorvido do fertilizante-15N (Nr+1dff r e Nr-1dff r), que representa o valor do N absorvido do adubo aplicado nas linhas adjacentes, por plantas da parcela (Nr dff r+I e Nr dff r.,). O valor de Ndff^ é calculado pela equação: Ndff total= Nr dff r + Nr+1dff r + Nr-1dff,

Organic matter and natural carbon-13 distribution in forested and cultivated oxisols

Etude de la distribution du carbone et de 13C et de leur variation suite au développement des cultures dans trois oxisols de la région de Piracicaba (Sao Paulo, Brésil

Utilização da reserva orgânica e de nitrogênio do tolete de plantio (colmo-semente) no desenvolvimento da cana-planta

Seedpieces with one node (one bud) plus half of the internodes at each side, were cut from the middle third of cane stalks, variety NA 56-79, grown with 1S N. The dry weight, N content and 15N abundance of cuttings were estimated from samples of each original stalk. The cuttings were planted in pots filled with 6kg of a Dark Red Latosol (RHODIC KANHAPLUDALF) sample. The experiment was conducted under greenhouse conditions, using a random design with 16 treatments (harvest times) and three replicates. The harvested plants were divided into shoots, roots and remaining seedpiece. The dry weight, N content and 15N abundance were determined in each sample. The results showed that the reduction of the dry weight of the seedpiece was compensated by new matter yield (shoot and root) only after three months of growth. During this period the emergence of fixing roots and of the primary shoot depended solely on the seedpiece reservoir. The later is also essential as a nitrogen source for the cane plant during 50-60 days after planting. After 6 months the dry matter of the original cuttings is reduced by 50% and 50% of its nitrogen is translocated to the cane plant. It may be estimated that, under field conditions, 6-12kg.ha-1 can be translocated from the original seedpieces to the cane plant (shoots and roots). These values can represent 5-10% of total N required by the cane plant.Toletes (colmo-semente) com um nó (uma gana) mais metade do entre-nó inferior e metade do superior foram obtidos do terço médio de colmos de cana-de-açúcar, marcados com 15N, da variedade NA 56-79. A massa seca, o conteúdo de nitrogênio e a abundância isotópica de 15N dos toletes foram estimados tomando-se por base os valores obtidos em amostra de cada colmo. Os toletes foram plantados em vasos com 6kg de terra colhida de uma Terra Roxa Estruturada Latossólica (RHODIC KANHAPLUDALF). O experimento foi conduzido em casa-de-vegetação, em delineamento inteiramente casualizado, com 16 tratamentos correspondentes à colheitas em diferentes tempos após o plantio. Nas plantas, subdivididas em amostras de parte aérea, raízes e tolete remanescente, foram determinados a massa seca, N-total e abundância de 15N. Dos resultados obtidos verificou-se que a redução da matéria seca do tolete somente foi compensada pela produção de novos tecidos por volta dos 3 meses do plantio. Nesse período, a emissão das raízes de fixação e a brotação do perfilho primário dependeu da reserva orgânica do tolete. A reserva de nitrogênio do tolete foi fundamental como fonte do nutriente à cana-planta nos 50-60 dias após o plantio. A degradação de 50% da reserva orgânica do tolete ocorreu até os 6 meses e possibilitou a liberação de 50% da reserva de nitrogênio que foi translocada aos novos tecidos da cana-planta. Pode-se estimar que de 6-12 kg.ha-1 do N-tolete são translocados aos novos tecidos (50% do N-tolete), valores estes que podem representar 5-10% das necessidades de N da cultura

Efeitos da densidade de população de plantas na cultura de couve-flor (Brassica oleracea L. var. botrytis)

An experiment was carried out to study the effects of the following population densities cauliflowers (plants per ha): 20,833 (0.60 m x 0.80 m), 25,641 (0.60 m x 0.65 m), ....37.037 (0.60 m x 0.45 m) , 55.555 (.0.60 m x 0.30 m), and 111,111 (0,60 m x 0,15 m) ; variety Snow ball. It was concluded that the effects of plant population density are greater on curd quality (weight and size) than on production per ha. The best plant population density to produce cauliflowers curd for Brazil market is from 20,000 to 25,000 plants/ha while for mini-curd is above 55,000 plants/ha.O experimento foi instalado na área experimental do Setor de Horticultura da ESALQ. (Piracicaba, SP), em um Latossol Roxo série "Luiz de Queiroz", em março de 1977, considerando as seguintes densidades de população: 20.833 plantas/ha (0,60 m x 0,80m), .. 25.641 plantas/ha (0,60 m x 0,65 m), 37.037 plantas/ha (..0.,60 m x 0,45 ml, 55.550 plantas/ha (,06Q m x 0,30 ,) e 111.111 plantas/ ha (0,60 m x 0,15 m). A partir dos resultados obtidos e para as condições do experimento concluiu-se que a densidade de população sobre a produção de couve-flor afeta mais a qualidade da cabeça (peso e tamanho), enquanto que o rendimento por área é pouco afetado. Para as condições do nosso mercado, a densidade ótima deve estar entre 20.000 a 25.000 plantas por ha e para a produção de mini-couve-flor mais de 55.000 plantas por ha, paraocultivar Bola de Neve

Readmissions after general surgery: a prospective multicenter audit

Background: Readmission rates after surgical procedures are viewed as a marker of quality of care and as a driver to improve outcomes in the United Kingdom, they are not remunerated. However, readmissions are not wholly avoidable. The aim of this study was to develop a regional overview of readmissions to determine the proportion that might be avoidable and to examine predictors of readmissions at a unit level. Methods: We undertook a prospective multicenter audit of readmissions following National Health Service funded general surgical procedures in five National Health Service hospitals and three independent sector providers over a 2-wk period. Basic demographic and procedure data were captured. Readmissions to hospitals were identified through acute admissions lists. Reason for readmission was identified, and the readmission data assessed by a senior surgical doctor as to whether it was avoidable. Results: We identified 752 operations in the study period with all followed up to 30 d. The overall rate of readmissions was 4.7%, with 40% of these judged as being potentially avoidable. Pain and wound problems accounted for the vast majority of avoidable readmissions. The number of unavoidable readmissions was correlated with the workload of each center (r ¼ 0.63, P ¼ 0.06) and as with the higher (British United Provident Association) complexity of surgery (r ¼ 0.90, P ¼ 0.01). Patient and demographic factors were not associated with readmissions. Conclusions: This prospective audit describes readmission rates after general surgery. Volume and complexity of work are associated with readmission rates. A large proportion of readmissions could be reduced by attention to analgesia and outpatient arrangements for wound management

A survey for variable young stars with small telescopes: II - mapping a protoplanetary disc with stable structures at 0.15 au

The HOYS citizen science project conducts long term, multifilter, high cadence monitoring of large YSO samples with a wide variety of professional and amateur telescopes. We present the analysis of the light curve of V1490 Cyg in the Pelican Nebula. We show that colour terms in the diverse photometric data can be calibrated out to achieve a median photometric accuracy of 0.02 mag in broadband filters, allowing detailed investigations into a variety of variability amplitudes over timescales from hours to several years. Using Gaia DR2 we estimate the distance to the Pelican Nebula to be 870 +70 −55 pc. V1490 Cyg is a quasi-periodic dipper with a period of 31.447 ± 0.011 d. The obscuring dust has homogeneous properties, and grains larger than those typical in the ISM. Larger variability on short timescales is observed in U and Rc−Hα, with U-amplitudes reaching 3 mag on timescales of hours, indicating the source is accreting. The Hα equivalent width and NIR/MIR colours place V1490 Cyg between CTTS/WTTS and transition disk objects. The material responsible for the dipping is located in a warped inner disk, about 0.15 AU from the star. This mass reservoir can be filled and emptied on time scales shorter than the period at a rate of up to 10−10 M�/yr, consistent with low levels of accretion in other T Tauri stars. Most likely the warp at this separation from the star is induced by a protoplanet in the inner accretion disk. However, we cannot fully rule out the possibility of an AA Tau-like warp, or occultations by the Hill sphere around a forming planet

Assessing associations between the AURKAHMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers

While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood appr