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141.
Antonio Rafael Sánchez-Rodríguez María Carmen del Campillo José Torrent 《Plant and Soil》2013,373(1-2):31-42
Background and aims
The possible influence of phosphorus (P) on iron (Fe) deficiency chlorosis in susceptible plants needs elucidation. In this work, we tested the hypothesis that Fe chlorosis can be aggravated at high levels of P in the substrate.Methods
Chickpea, lupin and peanut (in a preliminary experiment), and lupin and sorghum (in a second, factorial experiment) were successively grown on artificial substrates consisting of mixtures of Fe oxide-coated sand (FOCS), calcium carbonate (calcite) sand (CCS) and quartz sand to which phosphate was added at different doses.Results
The proportion of FOCS in the substrate had a significant positive effect on leaf chlorophyll concentration (as estimated via SPAD) in all crops. In the factorial experiment, the SPAD value was negatively affected by the proportion of CCS in the dicot (lupin) but not in the monocot (sorghum). In the preliminary experiment, increasing the P dose generally had little effect on the SPAD of plants grown on the FOCS-rich substrate but a negative effect on those grown on the FOCS-poor substrate. In the factorial experiment, the P dose negatively affected SPAD in both lupin and sorghum.Conclusions
Iron acquisition by the plant is negatively influenced by P probably because the solubility of the Fe oxides decreases with increasing coverage of their surfaces by sorbed phosphate. 相似文献142.
Estela D'Abril Ruíz-Leyja Rafael Villalobos-Molina Juan Javier López-Guerrero Itzell Alejandrina Gallardo-Ortíz Samuel Enoch Estrada-Soto Maximiliano Ibarra-Barajas 《Life sciences》2013
Aims
Hypertension is associated with the impairment of renal cyclooxygenase (COX) activity, which regulates vascular tone, salt and water balance and renin release. We aimed to evaluate the functional role of COX isoforms in kidneys isolated from spontaneously hypertensive rats (SHR) after α1-adrenoceptor (α1-AR) stimulation.Main methods
Male six-month-old SHR and normotensive Wistar-Kyoto rats (WKY) were used. The kidneys were isolated to measure perfusion pressure and COX-1- or COX-2-derived prostanoids in response to α1-AR activation.Key findings
The basal perfusion pressure was higher in SHR kidneys compared with WKY kidneys (95 ± 11 vs. 68 ± 6 mm Hg, P < 0.05). Phenylephrine induced a greater vasopressor response in SHR kidneys (EC50 of 1.89 ± 0.58 nmol) than WKY kidneys (EC50 of 3.30 ± 0.54 nmol, P < 0.05 vs. SHR). COX-1 inhibition decreased the α1-AR-induced vasoconstrictor response in WKY but did not affect SHR response, while COX-2 inhibition diminished the response in SHR. Both basal prostacyclin (PGI2) and thromboxane A2 (TxA2) values were higher in SHR kidney perfusates (P < 0.05) and were reduced by COX-1 and COX-2 inhibitors in both strains. Furthermore, phenylephrine increased PGI2 through COX-2 in WKY and through COX-1 in SHR, but the agonist did not significantly modify TxA2 in both strains.Significance
The data suggest that COX-1contributes to vasoconstrictor effects in WKY kidneys and that COX-2 has the same effect in SHR kidneys. The results also suggest that basal release of COX-2-derived vasoconstrictor prostanoids is involved in renal vascular hypersensitivity in SHR. 相似文献143.
144.
Vincenzo Penteriani Anna Kuparinen Maria del Mar Delgado Francisco Palomares José Vicente López-Bao José María Fedriani Javier Calzada Sacramento Moreno Rafael Villafuerte Letizia Campioni Rui Lourenço 《Oecologia》2013,173(3):753-766
We compared movement patterns and rhythms of activity of a top predator, the Iberian lynx Lynx pardinus, a mesopredator, the red fox Vulpes vulpes, and their shared principal prey, the rabbit Oryctolagus cuniculus, in relation to moon phases. Because the three species are mostly nocturnal and crepuscular, we hypothesized that the shared prey would reduce its activity at most risky moon phases (i.e. during the brightest nights), but that fox, an intraguild prey of lynx, would avoid lynx activity peaks at the same time. Rabbits generally moved further from their core areas on darkest nights (i.e. new moon), using direct movements which minimize predation risk. Though rabbits responded to the increased predation risk by reducing their activity during the full moon, this response may require several days, and the moon effect we observed on the rabbits had, therefore, a temporal gap. Lynx activity patterns may be at least partially mirroring rabbit activity: around new moons, when rabbits moved furthest and were more active, lynxes reduced their travelling distances and their movements were concentrated in the core areas of their home ranges, which generally correspond to areas of high density of rabbits. Red foxes were more active during the darkest nights, when both the conditions for rabbit hunting were the best and lynxes moved less. On the one hand, foxes increased their activity when rabbits were further from their core areas and moved with more discrete displacements; on the other hand, fox activity in relation to the moon seemed to reduce dangerous encounters with its intraguild predator. 相似文献
145.
Isabel Mateu‐Andrés Antoni Aguilella Fernando Boisset Rafael Currás Miguel Guara Emilio Laguna Antoni Marzo Mª Felisa Puche Joan Pedrola 《Botanical journal of the Linnean Society. Linnean Society of London》2013,171(4):700-712
Climate changes during the Quaternary had important effects on the evolution of European plant species. The distribution of genetic variability in rosemary, a strictly Mediterranean species of reputed Plio‐Quaternary origin for which the diversification centre is hypothesized to be located in the western part of the Mediterranean basin, was investigated across the species range by using plastid microsatellites [plastid simple sequence repeat (cpSSR)] markers. Seven out of the 17 primer pairs screened were polymorphic, with up to four alleles, yielding a total of 17 size variants combined into ten haplotypes. A permutation test to investigate for geographical structure showed no significant differences between RST and GST, indicating that the species lacks geographical structure. Low correlation between genetic and geographical distances was shown by the Mantel test. Bayesian analysis identified two coancestry groups of populations. The distribution of genetic diversity supports the hypothesized origin in the western Mediterranean basin, and with the demographic expansion test indicates three different routes of migration: a northern route expanding along the northern side of the Mediterranean and two southern routes, one from west to east through North Africa and reaching Cyrenaica, and a second to the south‐west of the Iberian Peninsula, from where it came back to the south–central areas. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013 , 171 , 700–712. 相似文献
146.
Paula Clemente Susana Peralta Alberto Cruz-Bermudez Lucía Echevarría Flavia Fontanesi Antoni Barrientos Miguel A. Fernandez-Moreno Rafael Garesse 《The Journal of biological chemistry》2013,288(12):8321-8331
Cytochrome c oxidase (COX) or complex IV of the mitochondrial respiratory chain plays a fundamental role in energy production of aerobic cells. In humans, COX deficiency is the most frequent cause of mitochondrial encephalomyopathies. Human COX is composed of 13 subunits of dual genetic origin, whose assembly requires an increasing number of nuclear-encoded accessory proteins known as assembly factors. Here, we have identified and characterized human CCDC56, an 11.7-kDa mitochondrial transmembrane protein, as a new factor essential for COX biogenesis. CCDC56 shares sequence similarity with the yeast COX assembly factor Coa3 and was termed hCOA3. hCOA3-silenced cells display a severe COX functional alteration owing to a decreased stability of newly synthesized COX1 and an impairment in the holoenzyme assembly process. We show that hCOA3 physically interacts with both the mitochondrial translation machinery and COX structural subunits. We conclude that hCOA3 stabilizes COX1 co-translationally and promotes its assembly with COX partner subunits. Finally, our results identify hCOA3 as a new candidate when screening for genes responsible for mitochondrial diseases associated with COX deficiency. 相似文献
147.
Zaida Araujo Francesca Giampietro María de los Angeles Bochichio Andrea Palacios Jenifer Dinis Jaime Isern Jacobus Henry de Waard Elsa Rada Rafael Borges Carlos Fernández de Larrea Angel Villasmil Magnolia Vanegas Jose Antonio Enciso-Moreno Manuel Alfonso Patarroyo 《Memórias do Instituto Oswaldo Cruz》2013,108(2):131-139
The goal of this study was to demonstrate the usefulness of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of pulmonary tuberculosis (PTB) and extrapulmonary TB (EPTB). This assay used 20 amino acid-long, non-overlapped synthetic peptides that spanned the complete Mycobacterium tuberculosis ESAT-6 and Ag85A sequences. The validation cohort consisted of 1,102 individuals who were grouped into the following five diagnostic groups: 455 patients with PTB, 60 patients with EPTB, 40 individuals with non-EPTB, 33 individuals with leprosy and 514 healthy controls. For the PTB group, two ESAT-6 peptides (12033 and 12034) had the highest sensitivity levels of 96.9% and 96.2%, respectively, and an Ag85A-peptide (29878) was the most specific (97.4%) in the PTB groups. For the EPTB group, two Ag85A peptides (11005 and 11006) were observed to have a sensitivity of 98.3% and an Ag85A-peptide (29878) was also the most specific (96.4%). When combinations of peptides were used, such as 12033 and 12034 or 11005 and 11006, 99.5% and 100% sensitivities in the PTB and EPTB groups were observed, respectively. In conclusion, for a cohort that consists entirely of individuals from Venezuela, a multi-antigen immunoassay using highly sensitive ESAT-6 and Ag85A peptides alone and in combination could be used to more rapidly diagnose PTB and EPTB infection. 相似文献
148.
149.
Teresa Braunwald Lisa Schwemmlein Simone Graeff-Hönninger William Todd French Rafael Hernandez William E. Holmes Wilhelm Claupein 《Applied microbiology and biotechnology》2013,97(14):6581-6588
Due to the increasing demand for sustainable biofuels, microbial oils as feedstock for the transesterification into biodiesel have gained scientific and commercial interest. Also, microbial carotenoids have a considerable market potential as natural colorants. The carbon to nitrogen (C/N) ratio of the respective cultivation media is one of the most important parameters that influence the production of microbial lipids and carotenoids. Thus, in the present experiment, the influence of different C/N ratios, initial glucose loadings, and ammonium concentrations of the cultivation medium on microbial cell growth and lipid and carotenoid production by the oleaginous red yeast Rhodotorula glutinis has been assessed. As a general trend, both lipid and carotenoid production increased at high C/N ratios. It was shown that not only the final C/N ratio but also the respectively applied initial carbon and nitrogen contents influenced the observed parameters. The lipid yield was not affected by different ammonium contents, while the carotenoid production significantly decreased both at low and high levels of ammonium supply. A glucose-based increase from C/N 70 to 120 did not lead to an increased lipid production, while carotenoid synthesis was positively affected. Generally, it can be asserted that lipid and carotenoid synthesis are stimulated at higher C/N ratios. 相似文献
150.
Rafael Bielza Galindo Alejandro Ortiz Espada Estefanía Arias Muñana Rocío Velasco Guzmán de Lázaro Asunción Mora Casado Ricardo Moreno Martín Blanca Tapia Salinas Javier Escalera Alonso Jorge Gómez Cerezo 《Revista espa?ola de geriatría y gerontología》2013