979 resultados para Arrow plot


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The objective of this work was to estimate the amounts of N fixed by cowpea in a traditional system and by cowpea and gliricidia in an agroforestry system in the Brazilian Northeast semiarid. The experiment was carried out in a randomized complete block design, in a split-plot arrangement, with four replicates, in the semiarid region of the state of Paraíba, Brazil. Plots consisted of agroforestry and traditional systems (no trees), and split-plots of the three crops planted between the tree rows in the agroforestry system. To estimate N fixation, plant samples were collected in the fourth growth cycle of the perennial species and in the fourth planting cycle of the annual species. In the agroforestry system with buffel grass and prickly-pear cactus, gliricidia plants symbiotically fix high proportions of N (>50%) and contribute with higher N amounts (40 kg ha-1 in leaves) than in the traditional system (11 kg ha-1 in grain and 18 kg ha-1 in straw). In the agroforestry system with maize and cowpea, gliricidia plants do not fix nitrogen, and N input is limited to the fixation by cowpea (2.7 kg ha-1), which is lower than in the traditional system due to its lower biomass production.

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O objetivo deste trabalho foi identificar datas de semeadura com menor ocorrência média de dias com excedente hídrico para a cultura do girassol, e determinar a persistência de dias consecutivos com excedente hídrico ao se considerar a capacidade de armazenamento de água disponível de diferentes solos da região central do Rio Grande do Sul. O desenvolvimento da cultura e o aprofundamento do sistema radicular foram simulados de acordo com a soma térmica para 14 datas de semeadura, de agosto até meados de fevereiro, com dados de 1968 até 2011. A partir da capacidade de armazenamento de água disponível para as diferentes classes de solos da região, calculou-se o balanço hídrico sequencial diário para determinar os dias com excesso hídrico. Avaliou-se a ocorrência de dias com excesso hídrico em diferentes subperíodos de desenvolvimento da cultura, e procedeu-se à análise exploratória com gráficos box-plot para determinação da persistência de dias consecutivos com excesso hídrico durante todo o ciclo da cultura. O excedente hídrico limita o cultivo de girassol em determinadas áreas e períodos na região central do Rio Grande do Sul. A persistência de dias consecutivos com excedente hídrico e a duração do ciclo de desenvolvimento da cultura são influenciados pela data de semeadura.

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Työn tarkoituksena oli tutkia kuinka kaasukuplat jakautuvat sellususpensioon, kun prosessiolosuhteita muutetaan. Kuplien kokojakauman avulla pyritään kartoittamaan kuinka kaasukuplat pilkkoutuvat ja onko olemassa raja-arvoa, milloin tehon lisäys ei enää pilko sellususpensiossa olevia kuplia pienemmiksi. Jakaumien avulla voidaan mahdollisesti kehittää kaasunpoistoa. Työssä selvitettiin voidaanko kameratekniikkaa käyttää kuplakokojen määrittämiseen sellusulpusta. Läpinäkymätön sellumassa tarjoaa kuvaukselle haasteellisen ympäristön. Myöskään kirjallisuudessa ei vastaavaa menetelmää aikaisemmin oltu käytetty. Kuvatusta materiaalista laskettiin kuplien halkaisijat, joita pyrittiin tarkastelemaan tilastollisesti. Tilastollinen tarkastelu toi eroja mittauspisteiden välille. Kuplien halkaisijoiden perusteella mallinnettiin kuplakokoon vaikuttavat prosessisuureet lineaarisella regressioanalyysillä. Mallinnuksen perusteella saatiinvasteisiin vaikuttavat riippumattomat muuttujat ja niiden matemaattiset malliyhtälöt. Tuloksina saatiin selville, että kuplien kokojakaumissa on eroja sekoitussäiliön eri puolilla. Sekoitussäiliössä suurten kuplien suhteellinen osuus kasvaa kaasupitoisuuden ja sakeuden noustessa. Mallinnuksen tärkeimpänä tuloksena voidaan todeta, että sakeus ja kaasutilavuus vaikuttavat kuplakokoon kasvattavasti. Kierrosnopeuden kasvattaminen pienentää kuplakokoa. Visuaalisen informaation avulla on helpompi ymmärtää kuinka kuplat käyttäytyvät.

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Alpine flora and climate change: monitoring of three summits in Valais (Switzerland) during the 20th century Climate change might trigger an upward shift of the flora in the Swiss Alps, especially since these experienced higher change in average than observed on a global scale. Previous investigations in the canton des Grisons (Switzerland) and Austria have revealed an increase of floristic diversity on alpine summits since the beginning of the 20th century. Three summits in Valais were revisited in this study: the Gornergrat (first inventory in 1919), the Torrenthorn (about in 1885) and the Beaufort (about in 1920). Every summit was newly inventoried in 2003 in the framework of the PERMANENT.PLOT.CH project. All showed a strong increase in species richness. On the Gornergrat (3135 m), 16 species were not found anymore, but 35 new ones were observed. The number of species on this exceptionally rich summit rose from 102 to 121. In comparison, the floristic richness increased from 24 to 63 species on the Torrenthorn (2924 m) and from 16 to 48 species on the Beaufort (3048 m). As in previous studies, this increase seems likely to be associated with climate change: the new species prefer, in average, higher temperature conditions than those previously prevailing on the summits. On the Gornergrat and Beaufort, our observations reveal a development of alpine meadows, whereas species typical of rocks and raw soils are predominantly colonising the Torrenthorn. This difference might be related to the important damage caused by wanderers on the vegetation of the Torrenthorn.

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It has been shown that for the reaction catalyzed by "biodegradative" L-threonine dehydratase from E. coli strains K-12 and 980 in 0.5 M phosphate-carbonate buffer, pH 8.4 and pH 9.5, the plots of initial reaction rate (v) versus the initial substrate concentration ([S]0 are characterized by several inflection points, i. e. an intermediate plateau. The plot of v versus the allosteric activator (AMP) concentration have very complicated shapes: there are several inflection points, and also the maximum at L-threonine concentration equal to 3-10(2) and 5-10(-2) M. High AMP concentrations inhibit the enzyme at high substrate concentrations. The reduced glutathion dose not influence the enzyme and does not alter the activating effect of AMP. On the basis of the data obtained it is proposed that the substrate and AMP shift the equilibrium between multiple oligomeric enzyme forms differing in catalytic activity and kinetic manifestations of allosteric interactions between the active and allosteric AMP-binding sites towards polymerization. Thus, the functioning the enzyme under study is discussed in the frames of the model of dissociating regulatory enzymes with multiple intermediate oligomeric forms.

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Background: The divergent glacial histories of southern and northern Europe affect present-day species diversity at coarse-grained scales in these two regions, but do these effects also penetrate to the more fine-grained scales of local communities?Methodology/Principal Findings: We carried out a cross-scale analysis to address this question for vascular plants in two mountain regions, the Alps in southern Europe and the Scandes in northern Europe, using environmentally paired vegetation plots in the two regions (n = 403 in each region) to quantify four diversity components: (i) total number of species occurring in a region (total gamma-diversity), (ii) number of species that could occur in a target plot after environmental filtering (habitat-specific gamma-diversity), (iii) pair-wise species compositional turnover between plots (plot-to-plot beta-diversity) and (iv) number of species present per plot (plot gamma-diversity). We found strong region effects on total gamma-diversity, habitat-specific gamma-diversity and plot-to-plot beta-diversity, with a greater diversity in the Alps even towards distances smaller than 50 m between plots. In contrast, there was a slightly greater plot alpha-diversity in the Scandes, but with a tendency towards contrasting region effects on high and low soil-acidity plots.Conclusions/Significance: We conclude that there are strong regional differences between coarse-grained (landscape- to regional-scale) diversity components of the flora in the Alps and the Scandes mountain ranges,but that these differences do not necessarily penetrate to the finest-grained (plot-scale) diversity component, at least not on acidic soils. Because different processes can lead to a similar pattern, we discuss the consistency of our results with Quaternary history and other divergent features between the two regions such as habitat connectivity, selection for vagility and environmental differences not accounted for in our analyses

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BACKGROUND: Workers with persistent disabilities after orthopaedic trauma may need occupational rehabilitation. Despite various risk profiles for non-return-to-work (non-RTW), there is no available predictive model. Moreover, injured workers may have various origins (immigrant workers), which may either affect their return to work or their eligibility for research purposes. The aim of this study was to develop and validate a predictive model that estimates the likelihood of non-RTW after occupational rehabilitation using predictors which do not rely on the worker's background. METHODS: Prospective cohort study (3177 participants, native (51%) and immigrant workers (49%)) with two samples: a) Development sample with patients from 2004 to 2007 with Full and Reduced Models, b) External validation of the Reduced Model with patients from 2008 to March 2010. We collected patients' data and biopsychosocial complexity with an observer rated interview (INTERMED). Non-RTW was assessed two years after discharge from the rehabilitation. Discrimination was assessed by the area under the receiver operating curve (AUC) and calibration was evaluated with a calibration plot. The model was reduced with random forests. RESULTS: At 2 years, the non-RTW status was known for 2462 patients (77.5% of the total sample). The prevalence of non-RTW was 50%. The full model (36 items) and the reduced model (19 items) had acceptable discrimination performance (AUC 0.75, 95% CI 0.72 to 0.78 and 0.74, 95% CI 0.71 to 0.76, respectively) and good calibration. For the validation model, the discrimination performance was acceptable (AUC 0.73; 95% CI 0.70 to 0.77) and calibration was also adequate. CONCLUSIONS: Non-RTW may be predicted with a simple model constructed with variables independent of the patient's education and language fluency. This model is useful for all kinds of trauma in order to adjust for case mix and it is applicable to vulnerable populations like immigrant workers.

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Leaf area measurements are required in several agronomical studies. Usually, there is an interest for measurement methods that are simple, quick and that will not destroy the leaf. The objectives of this work were to evaluate leaf area (y), length (l) and width (w) of 20 half-sibling progenies of custard apple tree (Annona squamosa L.), and to fit regression equations of the type y = a + bx, where x = l.w, that will allow y to be estimated based on l and w. The experiment was conducted as random blocks with five replicates and four plants per plot. Five mature leaves were randomly collected from each plant. Leaf area was measured with an automatic measuring device and leaf dimensions were determined with a ruler. All values of b were different from zero. Differences occurred only in 11% of the 190 possible comparison pairs between progenies, with regard to the estimates of b. No differences were observed between progenies with respect to leaf length, width and area. In view of this fact, the equation y = 0.72 x (R² = 0.77) was fitted for all progenies.

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In orange commercial farms, Zn deficiencies symptoms and small fruits were observed in Corrientes, Argentine. During four years (1995 to 1998), Valencia orange (Citrus sinensis Osb.) on Rough lemon (C. jambhiri Lush.) rootstock, implanted in 1974 in sandy soil, where six treatments were tested. Treatments varied from 1 to 3 Kg KCl.tree-1.year-1 (applied in April and December) with and without Zineb 80, 0,35%. year-1, 20 L. tree-1 (13,3 g Zn.tree-1 applied in December). The experimental design was a randomized complete block with four replications, with a single tree and borders in the experimental plot. Foliar sample were taken every year in Autumn and Summer, foliar concentrations of Zn and K were determined by atomic spectrum absorption. Harvested fruits were classified into small, medium and big. Analysis of Variance, Tukey test and Pearson correlations between production and foliar concentrations were performed. Higher fertilization levels of K with Zn increased medium and big fruits production (Kg and percentage). Foliar concentrations of K and Zn were positively correlated with big and medium fruit production and negatively correlated with small one. Chemical names used: Ethilenbis-ditiocarbamate of Zn (Zineb).

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The experiment evaluated the agronomic characteristics of 'Prata-anã' and 'Maçã' banana plants, in the São Manuel region of São Paulo state. In the first crop cycle, the number of days from planting to inflorescence and from inflorescence to harvest; the number of shoots until the appearance of inflorescence and during the harvest period; active leaves number at inflorescence appearance and during the harvest period. Were evaluated yield parameters: like average weight of bunch, hand, rachis and fruit; average fruit number per hand and bunch; average fruit diameter and length. Incidences of plague diseases, as well as their severity were also evaluated. Delineation was totally at random, with 2 treatments, 15 replications and 5 useful plants per experimental plot. Both cultivars were characterized by values of descriptive average statistics and standard deviation, for characteristic interests. Number of days from planting to harvest was similar for both 'Prata-anã' and 'Maçã', 574 and 567 days respectively. Banana plants showed good phytosanitary quality throughout the whole cycle.

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Actually mango (Mangifera indica, L.) is considered one of the largest Brazilian fruitbusiness for the export market. Cultivar selection having high fruit quality is a fundamental step to obtain excellent results in this business. A mango breeding program based on intervarietal hybridization may produce new improved cultivars for mango growers. Mango hybrids have been obtained by controlled or open crosses. In the last one, it is important to identify the male parent because it is useful for the genetic cultivar history, thus it is important for planning further improvements. This work presents a parentage test using among others parameters RAPD (Random amplified Polymorphic DNA) markers to estimate the male parent of the selected hybrids in an open cross plot by using five mango cultivars densely planted in a latin square design.

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Apparently, there are no custard apple cultivars defined for the northeastern region of Brazil. The establishment of breeding programs aimed at the selection of types from productive locations for later cloning is desirable. This work's objective was to evaluate the yield (during the first three crops) and quality (first crop) of fruits from 20 half-sibling custard apple tree progenies, selected from home orchards. An additional objective was to estimate genetic parameters for the traits evaluated. A micro sprinkling-irrigated experiment was conducted in Mossoró-RN, Brazil, as random blocks with five replications. In characteristics evaluated for periods longer than a year (diameter, height and mean weight of fruits, number of fruits ha-1 and fruit yield (kg ha-1), and a split-plot design was adopted, with progenies considered as plots and annual cropping seasons as subplots. The best progenies in terms of fruit yield (A3 and A4) are not necessarily the best for fruit dimensions and fruit mean weight (A2, FE4, JG1, JG2, SM1, SM7, and SM8). These progenies show great potential to be used in future studies on crosses or on vegetative propagation. In this regard, progeny JG2 should be highlighted as promising in terms of yield and fruit size. The progenies are not different with regard to percentages (in relation to mean fruit mass) of pericarp, endocarp, seeds, and receptacle, in the fruit, and fruit volume, number of seeds/fruit, and total soluble solids content in the fruit pulp, but progeny FE4 presents higher total titratable acidity in the fruit pulp. Narrow-sense heritability estimates were relatively high for all characteristics in which there was variability between progenies, with higher values for number of fruits ha-1 (80 %) and fruit yield (78 %). Relatively high coefficients of genotypic variation (around 20%) were observed for number of fruits ha-1 and fruit yield, with lower values for the other characteristics. There were positive genotypic and phenotypic correlations between fruit diameter (FD) and fruit height, FD and mean fruit weight, and number of fruits ha-1 and fruit yield.

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Se aplican métodos ensayados en otros países (Scenic Beauty Estimation Method, SBE) para la determinación de las cualidades estéticas de masas forestales de interés recreativo a parcelas en diversas localizaciones del haya en Cataluña, abarcando diferencias significativas en estación, origen, edad y forma de masa. Las valoraciones se refieren a las cualidades estéticas de los rodales de haya vistos desde el interior del bosque, es decir, tal como son apreciados por parte de los visitantes de los montes. Las valoraciones se obtienen a través de paneles de observadores en sesiones fotográficas, se transforman a una escala común y se relacionan mediante análisis de regresión a las variables dasométricas tomadas en las parcelas de inventario. El desarrollo de modelos estadísticos que describen preferencias sociales permite medir la aportación de las diferentes variables dasométricas a la mejora estética de las masas de haya, y puede servir como guía en la ordenación de hayedos en que el uso público sea predominante o muy importante.

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Este estudio está basado en el muestreo de campo y posterior análisis de 24 parcelas de hayedo seleccionadas mediante una estratificación de su área de distribución basada en la clasificación CLATERES de la Ecorregión Catalano-Aragonesa. En cada parcela se han evaluado 3 parámetros fisiográficos, 15 climáticos y 18 edáficos, a partir de los cuales se han establecido sus valores paramétricos centrales y marginales que permiten definir los hábitats fisiográfico, climático y edáfico de las masas de Fagus sylvatica L. en Cataluña. Los hayedos catalanes se presentan sobre substratos litológicos muy diversos (plutonitas, vulcanitas, metamorfitas y sedimentitas, tanto ácidas como básicas), con texturas predominantes francas, franco-arenosas o franco-limosas. Los suelos, según FAO, son mayoritariamente cambisoles. A pesar de que la capacidad de retención de agua de sus suelos es escasa, la sequía fisiológica es reducida. Los humus predominantemente pertenecen a los tipos mull forestal y mull cálcico. Además, se presentan una serie de parámetros selvícolas ( Densidad de pies y densidad de chirpiales, Area basimétrica, Altura Total dominante, Índices de Hart-Becking, Índice de Calidad de Estación y Edad de la masa) que al correlacionarlos con los ecológicos nos ha permitido comprobar que los mejores hayedos se encuentran en las localizaciones más térmicas, en las que incluso se podría producir sequía fisiológica si no fuera por que existen suficientes precipitaciones estivales.