5,928 research outputs found
Changes in the Distribution of Carbohydrates Due to Water Stress and Root-Shoot Ratio as an Index of Drought Resistance in Ecotypes of Adesmia bicolor (Poir.) D.C.
The genera Adesmia, is found in the “El Plata” area. Adesmia bicolor (Poir). D.C. is one of the most common species in Uruguay that belongs to this genera. In this study, three ecotypes were collected from different kinds of environments. Ecotypes 016, 2316 and 7017, came from superficial-soil, clay-soil and sandy soil, respectively. The ecotypes of Adesmia bicolor (Poir.) DC. were studied under water-stress conditions (two levels), during two stages: vegetative phase and beginning of blossom. In both stages, leaf-water potential (LWP), leaf-relative-water content (LRWC), leaf-dry matter (LDM), stem-dry matter (SDM) and root-dry matter (RDM) were measured, while root-shoot ratio [RSR=RDM/(LDM+SDM)] was calculated. During the first stage, ecotype 2316 was more affected by water stress (LWP = -2.238 MPa, LRWC = 49.248 %), while ecotypes 016 and 7017 were more tolerant to water stress (LWP = -1.600 MPa, LRWC = 82.120 % and LWP= -1.628 MPa, LRWC = 73.407 %, respectively). At this time we noticed a differential partition between LDM and SDM, without affecting the root-shoot ratio. Ecotype 016 under water stress, sent more carbohydrates to the stem rather than to the leaves, while in the ecotypes 2316 and 7017 there could not be found any difference in the partition associated with water stress. On the second stage, all the plants showed better hydric conditions; ecotype 2316 was the most sensitive ecotype (LRWC = 78.098 %) and ecotype 7017 was the least sensitive (LRWC = 89.448 %). However, ecotype 2316 showed good leaf and stem yields for both stages, even under the first water-stress cycle; while ecotype 016 was the least productive ecotype. Root-shoot ratio was associated with differences in the water stress resistance between ecotypes. On the first stage, RSR for ecotypes 016, 7017 and 2316 were 0.263, 0.224 and 0.197 respectively; on the second stage, ecotype 7017 showed the highest RSR (0.333). It is suggested that root-shoot ratio could be used as an index of selection towards drought resistance among those ecotypes. This ratio would not be influenced by temporary water stress conditions
NIR spectroscopy of the Sun and HD20010 - Compiling a new linelist in the NIR
Context: Effective temperature, surface gravity, and metallicity are basic
spectroscopic stellar parameters necessary to characterize a star or a
planetary system. Reliable atmospheric parameters for FGK stars have been
obtained mostly from methods that relay on high resolution and high
signal-to-noise optical spectroscopy. The advent of a new generation of high
resolution near-IR spectrographs opens the possibility of using classic
spectroscopic methods with high resolution and high signal-to-noise in the NIR
spectral window. Aims: We aim to compile a new iron line list in the NIR from a
solar spectrum to derive precise stellar atmospheric parameters, comparable to
the ones already obtained from high resolution optical spectra. The spectral
range covers 10 000 {\AA} to 25 000 {\AA}, which is equivalent to the Y, J, H,
and K bands. Methods: Our spectroscopic analysis is based on the iron
excitation and ionization balance done in LTE. We use a high resolution and
high signal-to-noise ratio spectrum of the Sun from the Kitt Peak telescope as
a starting point to compile the iron line list. The oscillator strengths (log
gf) of the iron lines were calibrated for the Sun. The abundance analysis was
done using the MOOG code after measuring equivalent widths of 357 solar iron
lines. Results: We successfully derived stellar atmospheric parameters for the
Sun. Furthermore, we analysed HD20010, a F8IV star, from which we derived
stellar atmospheric parameters using the same line list as for the Sun. The
spectrum was obtained from the CRIRES- POP database. The results are compatible
with the ones found in the literature, confirming the reliability of our line
list. However, due to the quality of the data we obtain large errors.Comment: 9 pages and 9 figure
Ecologia reprodutiva do taxi-branco (Sclerolobium paniculatum var. paniculatum Vogel) Leg: Caesalpinioideae.
Deposição de serapilheira e de nutrientes de duas espécies da Amazônia.
A capacidade da Floresta Amazônica em desenvolver-se sobre solos com baixa disponibilidade de nutrientes e com grande produção de biomassa deve-se à eficiente deposição e rápida liberação dos elementos minerais mediante a decomposição da serapilheira e reabsorção através de raízes superficiais. Considerando a necessidade de obter-se conhecimentos sobre a ciclagem de nutrientes de espécies da Amazônia, plantadas em ecossistema de terra firme, no presente trabalho, avaliou-se, entre as idades de 43 e 55 meses, a deposição de serapilheira, a concentração, o conteúdo e as variações mensais de N, P, K, Ca, Mg e S de Ceiba pentandra e de Virola surinamensis, plantadas em solo classificado como Latossolo Amarelo. Para tanto, coletores de 2,40 m de largura por 3,00 m de comprimento foram instalados no centro de cada parcela das espécies estudadas. Os resultados permitiram as seguintes conclusões: 1) No período de 12 meses, Ceiba pentandra depositou o dobro de serapilheira quando comparada à Virola surinamensis. 2) A concentração e o conteúdo de N, P, K, Ca, Mg e S foram maiores na serapilheira de Ceiba do que na de Virola. 3) As maiores deposições deste nutrientes na serapilheira dessas espécies ocorreram na estação seca, com exceção de Ca na serapilheira de Virola, o qual ocorreu na estação chuvosa
Parasites in Astronotus crassipinnis (Pisces: Cichlidae) from the Jari River, a tributary of the Amazon River in state of Amapá, Northern Brazil.
Parasites community of Astronotus crassipinnis (Cichlidae), a fish from the Brazilian Amazon.
We provide the first study on the diversity and community of parasites in Astronotus crassipinnis from the lower Amazon River, in Brazil. Of 35 hosts examined, 100% were infected with one or more species of parasites, such as Gussevia asota, Gussevia astronoti, Gussevia rogersi, Posthodiplostomum sp., Contracaecum sp., Gorytocephalus sp. and Dolops longicauda. Gussevia asota, G. astronoti and G. rogersi were dominant, and, in total, 9788 parasites were collected. The richness of parasite species (4.9±0.7), Brillouin diversity (0.46±0.28) and evenness (0.29±0.17) were low. Parasites had aggregated dispersion, parasitism did not affect the host condition factor, and host size did not influence abundance, species richness and parasite diversity. The parasitic fauna was characterized by the presence of few species of parasites with high prevalence and low abundance, specifically the endoparasites, besides dominance of ectoparasites. The presence of endoparasites indicates that the diet of A. crassipinnis consists mostly of mollusks and microcrustaceans. This fish species is an intermediate host for Posthodiplostomum sp., Contracaecum sp. and Gorytocephalus sp., parasites found in larval stage. Finally, the behavior and availability of infective stages, which are intermediate hosts for endoparasites, were factors structuring the communities of endoparasites
Numerical Model of Constrained Wave Energy Hyperbaric Converter under Full-Scale Sea Wave Conditions
Funding Information: This research was funded by Fundação para a Ciência e a Tecnologia (FCT.IP) through the grant UIDB/00667/2020 (UNIDEMI). This work was also supported by the project SURVIWEC PID2020-113245RB-I00 and by the project ED431C 2021/44 “Programa de Consolidación e Estructuración de Unidades de Investigación Competitivas”. This study forms part of the Marine Science programme (ThinkInAzul) supported by Ministerio de Ciencia e Innovación and Xunta de Galicia with funding from the European Union NextGenerationEU (PRTR-C17.I1) and European Maritime and Fisheries Fund. Funding Information: The authors acknowledge Fundação para a Ciência e a Tecnologia (FCT.IP) for its financial support through the grant UIDB/00667/2020 (UNIDEMI). This work was also supported by the project SURVIWEC PID2020-113245RB-I00 financed by MCIN/AEI/10.13039/501100011033 and by the project ED431C 2021/44 ”Programa de Consolidación e Estructuración de Unidades de Investigación Competitivas” financed by Xunta de Galicia, Consellería de Cultura, Educación e Universidade. This study forms part of the Marine Science programme (ThinkInAzul) supported by Ministerio de Ciencia e Innovación and Xunta de Galicia with funding from the European Union NextGenerationEU (PRTR-C17.I1) and European Maritime and Fisheries Fund. Publisher Copyright: © 2022 by the authors.A 2D numerical investigation of the power absorption of a constrained wave energy hyperbaric converter (WEHC) under full-scale sea wave conditions is presented. A fully non-linear numerical model DualSPHysics, based on the coupling of a smoothed particle hydrodynamics (SPH) fluid solver with a multibody dynamics solver, is used to model the interaction between wave and WEHC sub-systems. The numerical model was first validated against experimental data for a similar device, with a good accordance between PTO position and velocity. The model is then employed to study the hydrodynamics of a constrained WEHC considering several sea states, different hydraulic power take-off (PTO) damping and breakwater geometries. It is observed that the capture width ratio (CWR) is particularly sensitive to variations in the PTO damping, although the CWR absolute maximum is less sensitive considering mild variations applied to the PTO damping. Both wave height and wave period have an important effect on the CWR. The breakwater geometry is also essential for the performance of the WEHC, with a decrease in maximum CWR of about 15% for porous breakwater. These results are necessary to understand the full-scale behaviour of WEHC.publishersversionpublishe
Leaf nutrient content on seven plum cultivars with grafted by budding or own-rooted trees.
Abstract Several studies have been conducted in Brazil with rooting of plum scion cultivars, however, it is not known the performance and benefits of own-rooted trees at field. This study aimed to evaluate the leaf nutrient content (N, P, K, Ca, Mg, Fe, Mn, Zn, Cu and B) in seven Japanese plum cultivars (Prunus salicina) on the 2nd and 3rd year after field planting, whose nursery trees were produced by “T-inverted” budding method over ‘Capdeboscq’ peach (P. persica) or by own-rooted hardwood cuttings. The experimental design was in randomized blocks, factorial 7 x 2 (cultivars x nursery tree types), with five replicates of one tree per plot. We conclude that leaf nutrient content of Japanese plums varies among cultivars; however there is no cultivar that stands out in all macro and micronutrients evaluated. K, Ca and Mn leaf contents, when affected by nursery tree types tested, were always higher in own-rooted trees. However, Mg leaf contents, when affected by nursery tree types tested, were always higher in budded trees on ‘Capdeboscq’ peach. Own-rooted plum trees of ‘Amarelinha’, ‘Blood Plum’, ‘Pluma-7’ and ‘Reubennel’ presented higher Mn leaf contents, in relation to budded trees of these cultivars on ‘Capdeboscq’. Own-rooted ‘Cerejinha’ plum trees have highest K leaf content and also increase the agronomic interpretation class in relation to the budded trees of this cultivar on ‘Capdeboscq’
Progênies de segunda geração de grevilea: produção de madeira na região de Londrina, PR.
O uso da grevílea (Grevillea robusta Cunn) não se restringe somente ao sombreamento de cafezais, ornamentação e quebra-ventos, é também usada pela apicultura e na produção de madeira para usos diversos. O presente trabalho objetivou estimar a produção de madeira e estabelecer fontes de sementes melhoradas para plantios comerciais na região de Londrina, PR. Para tal, um experimento com 37 progênies de segunda geração foi instalado no Distrito de Maravilha, Município de Londrina, PR, com coordenadas geográficas 23°23’30"S e 51°11’05"W. O delineamento experimental utilizado foi de blocos ao acaso com parcelas lineares de cinco plantas distribuídas aleatoriamente com oito repetições, num espaçamento de 3 m x 3 m. A partir das medições das alturas e dos diâmetros na altura do peito (DAP), a variável estimada (volume cilíndrico) foi analisada para comparar as médias entre as progênies. Concluiu-se que em Londrina, a família mais produtiva em volume e com maior sobrevivência é da procedência australiana Duck Creek (NSW).Nota técnica
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