79 results on '"Zamora O"'
Search Results
2. Mobility of atrazine in soils of a wastewater irrigated maize field
- Author
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Salazar-Ledesma, M., Prado, B., Zamora, O., and Siebe, C.
- Published
- 2018
- Full Text
- View/download PDF
3. Extracts of Chilean native fruits inhibit oxidative stress, inflammation and insulin-resistance linked to the pathogenic interaction between adipocytes and macrophages
- Author
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Reyes-Farias, M., Vasquez, K., Fuentes, F., Ovalle-Marin, A., Parra-Ruiz, C., Zamora, O., Pino, M.T., Quitral, V., Jimenez, P., Garcia, L., and Garcia-Diaz, D.F.
- Published
- 2016
- Full Text
- View/download PDF
4. 2,4-D mobility in clay soils: Impact of macrofauna abundance on soil porosity
- Author
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Prado, B., Strozzi, A. Gastelum, Huerta, E., Duwig, C., Zamora, O., Delmas, P., Casasola, D., and Márquez, J.
- Published
- 2016
- Full Text
- View/download PDF
5. Geochemistry of the extensive peralkaline pyroclastic flow deposit of NW Mexico, based on conventional and handheld X-ray fluorescence. Implications in a regional context/Geoquímica del extenso depósito de flujo piroclástico hiperalcalino del NW de México, basada en fluorescencia de rayos X convencional y portátil. Implicaciones en un contexto regional
- Author
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Vidal-Solano, J.R., Cruz, R. Lozano Santa, Zamora, O., Mendoza-Cordova, A., and Stock, J.M.
- Published
- 2013
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- View/download PDF
6. Determination of benzimidazole fungicides in water samples by on-line MISPE–HPLC
- Author
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Zamora, O., Paniagua, E. E., Cacho, C., Vera-Avila, L. E., and Perez-Conde, C.
- Published
- 2009
- Full Text
- View/download PDF
7. Efecto del nitrogeno y humedad del suelo sobre la concentracion foliar de nutrimentos y rendimiento en cultivo de melon
- Author
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Cigales-Rivero, M.R., Pérez-Zamora, O., and Pérez-Castro, K.G.
- Published
- 2006
8. Saphenous vein eversion: A novel technique for Hickman® catheter insertion
- Author
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ZAMORA, O. and MERHAV, H. J.
- Published
- 2005
9. Medical malpractice and health maintenance organizations: evolving theories and ERISA's impact.
- Author
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Zamora, O. Mark
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Physicians -- Malpractice ,Tort liability of hospitals -- Laws, regulations and rules ,Health maintenance organizations -- Officials and employees ,Employee Retirement Income Security Act of 1974 - Published
- 1995
10. Probing 3D and NLTE models using APOGEE observations of globular cluster stars.
- Author
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Masseron, T., Osorio, Y., García-Hernández, D. A., Prieto, C. Allende, Zamora, O., and Mészáros, Sz.
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GALACTIC evolution ,GLOBULAR clusters ,THERMODYNAMIC equilibrium ,DATA modeling - Abstract
Context. Hydrodynamical (or 3D) and non-local thermodynamic equilibrium (NLTE) effects are known to affect abundance analyses. However, there are very few observational abundance tests of 3D and NLTE models. Aims. We developed a new way of testing the abundance predictions of 3D and NLTE models, taking advantage of large spectroscopic survey data. Methods. We use a line-by-line analysis of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra (H band) with the Brussels Automatic Code for Characterizing High accUracy Spectra (BACCHUS). We compute line-by-line abundances of Mg, Si, Ca, and Fe for a large number of globular cluster K giants in the APOGEE survey. We compare this line-by-line analysis against NLTE and 3D predictions. Results. While the 1D–NLTE models provide corrections in the right direction, there are quantitative discrepancies between different models. We observe a better agreement with the data for the models including reliable collisional cross-sections. The agreement between data and models is not always satisfactory when the 3D spectra are computed in LTE. However, we note that for a fair comparison, 3D corrections should be computed with self-consistently derived stellar parameters, and not on 1D models with identical stellar parameters. Finally, we focus on 3D and NLTE effects on Fe lines in the H band, where we observe a systematic difference in abundance relative to the value from the optical. Our results suggest that the metallicities obtained from the H band are more accurate in metal-poor giants. Conclusions. Current 1D–NLTE models provide reliable abundance corrections, but only when the atom data and collisional cross-sections are accurate and complete. Therefore, we call for more atomic data for NLTE calculations. In contrast, we show that 3D corrections in LTE conditions are often not accurate enough, thus confirming that 3D abundance corrections are only valid when NLTE is taken into account. Consequently, more extended self-consistent 3D–NLTE computations need to be made. The method we have developed for testing 3D and NLTE models could be extended to other lines and elements, and is particularly suited for large spectroscopic surveys. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
11. Crustal structure across southern Mexico inferred from gravity data
- Author
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Campos-Enrı́quez, J.O and Sánchez-Zamora, O
- Published
- 2000
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12. Heavy-element Abundances in P-rich Stars: A New Site for the s-process?
- Author
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Masseron, T., García-Hernández, D. A., Zamora, O., and Manchado, A.
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- 2020
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13. Cool stars in the Galactic center as seen by APOGEE: M giants, AGB stars, and supergiant stars and candidates.
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Schultheis, M., Rojas-Arriagada, A., Cunha, K., Zoccali, M., Chiappini, C., Zasowski, G., Queiroz, A. B. A., Minniti, D., Fritz, T., García-Hernández, D. A., Nitschelm, C., Zamora, O., Hasselquist, S., Fernández-Trincado, J. G., and Munoz, R. R.
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ASYMPTOTIC giant branch stars ,GALACTIC bulges ,SUPERGIANT stars ,GALACTIC evolution ,STARS ,INTERSTELLAR reddening ,GALACTIC center - Abstract
The Galactic center region, including the nuclear disk, has until recently been largely avoided in chemical census studies because of extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), allow the measurement of metallicities in the inner region of our Galaxy. Making use of the latest APOGEE data release (DR16), we are able for the first time to study cool Asymptotic Giant branch (AGB) stars and supergiants in this region. The stellar parameters of five known AGB stars and one supergiant star (VR 5-7) show that their location is well above the tip of the red giant branch. We studied metallicities of 157 M giants situated within 150 pc of the Galactic center from observations obtained by the APOGEE survey with reliable stellar parameters from the APOGEE pipeline making use of the cool star grid down to 3200 K. Distances, interstellar extinction values, and radial velocities were checked to confirm that these stars are indeed situated in the Galactic center region. We detect a clear bimodal structure in the metallicity distribution function, with a dominant metal-rich peak of [Fe/H] ∼ +0.3 dex and a metal-poor peak around {Fe/H] = −0.5 dex, which is 0.2 dex poorer than Baade's Window. The α-elements Mg, Si, Ca, and O show a similar trend to the Galactic bulge. The metal-poor component is enhanced in the α-elements, suggesting that this population could be associated with the classical bulge and a fast formation scenario. We find a clear signature of a rotating nuclear stellar disk and a significant fraction of high-velocity stars with v
gal > 300 km s−1 ; the metal-rich stars show a much higher rotation velocity (∼200 km s−1 ) with respect to the metal-poor stars (∼140 km s−1 ). The chemical abundances as well as the metallicity distribution function suggest that the nuclear stellar disk and the nuclear star cluster show distinct chemical signatures and might be formed differently. [ABSTRACT FROM AUTHOR]- Published
- 2020
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14. Physical characterization of 2020 AV2, the first known asteroid orbiting inside Venus orbit.
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Popescu, M, de León, J, de la Fuente Marcos, C, Vaduvescu, O, de la Fuente Marcos, R, Licandro, J, Pinter, V, Tatsumi, E, Zamora, O, Fariña, C, and Curelaru, L
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ASTEROID orbits ,VENUS (Planet) ,OPTICAL telescopes ,NEAR-earth asteroids ,ASTEROIDS ,SOLAR system ,SOLAR wind - Abstract
The first known asteroid with the orbit inside that of Venus is 2020 AV
2 . This may be the largest member of a new population of small bodies with the aphelion smaller than 0.718 au, called Vatiras. The surface of 2020 AV2 is being constantly modified by the high temperature, by the strong solar wind irradiation that characterizes the innermost region of the Solar system, and by high-energy micrometeorite impacts. The study of its physical properties represents an extreme test-case for the science of near-Earth asteroids. Here, we report spectroscopic observations of 2020 AV2 in the 0.5–1.5-μm wavelength interval. These were performed with the Nordic Optical Telescope and the William Herschel Telescope. Based on the obtained spectra, we classify 2020 AV2 as a Sa-type asteroid. We estimate the diameter of this Vatira to be |$1.50_{-0.65}^{+1.10}$| km by considering the average albedo of A-type and S-complex asteroids (|$p_V=0.23_{-0.08}^{+0.11}$|), and the absolute magnitude (H = 16.40 ± 0.78 mag). The wide spectral band around 1 μm shows the signature of an olivine-rich composition. The estimated band centre BIC = 1.08 ± 0.02 μm corresponds to a ferroan olivine mineralogy similar to that of brachinite meteorites. [ABSTRACT FROM AUTHOR]- Published
- 2020
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15. H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia.
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Fernández-Trincado, J. G., Zamora, O., Souto, Diogo, Cohen, R. E., Dell'Agli, F., García-Hernández, D. A., Masseron, T., Schiavon, R. P., Mészáros, Sz., Cunha, K., Hasselquist, S., Shetrone, M., Schiappacasse Ulloa, J., Tang, B., Geisler, D., Schleicher, D. R. G., Villanova, S., Mennickent, R. E., Minniti, D., and Alonso-García, J.
- Subjects
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GLOBULAR clusters , *GALACTIC bulges , *GIANT stars , *SUPERGIANT stars , *GALACTIC evolution , *ASYMPTOTIC giant branch stars - Abstract
We present an elemental abundance analysis of high-resolution spectra for five giant stars spatially located within the innermost regions of the bulge globular cluster NGC 6522 and derive Fe, Mg, Al, C, N, O, Si, and Ce abundances based on H-band spectra taken with the multi-object APOGEE-north spectrograph from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Of the five cluster candidates, two previously unremarked stars are confirmed to have second-generation (SG) abundance patterns, with the basic pattern of depletion in C and Mg simultaneous with enrichment in N and Al as seen in other SG globular cluster populations at similar metallicity. In agreement with the most recent optical studies, the NGC 6522 stars analyzed exhibit (when available) only mild overabundances of the s-process element Ce, contradicting the idea that NGC 6522 stars are formed from gas enriched by spinstars and indicating that other stellar sources such as massive AGB stars could be the primary polluters of intra-cluster medium. The peculiar abundance signatures of SG stars have been observed in our data, confirming the presence of multiple generations of stars in NGC 6522. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
16. Exploring circumstellar effects on the lithium and calcium abundances in massive Galactic O-rich AGB stars.
- Author
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Pérez-Mesa, V., Zamora, O., García-Hernández, D. A., Osorio, Y., Masseron, T., Plez, B., Manchado, A., Karakas, A. I., and Lugaro, M.
- Subjects
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ASYMPTOTIC giant branch stars , *NEUTRON capture , *SUPERGIANT stars , *STELLAR winds , *RADIOISOTOPES , *LITHIUM - Abstract
Context. We previously explored the circumstellar effects on Rb and Zr abundances in a sample (21) of massive Galactic O-rich asymptotic giant branch (AGB) stars. Here we are interested in clarifying the role of the extended atmosphere in the case of Li and Ca. Li is an important indicator of hot bottom burning while the total Ca abundances in these stars could be affected by neutron captures. Aims. We report new Li and Ca abundances in a larger sample (30) of massive Galactic O-rich AGB stars by using more-realistic extended model atmospheres. Li abundances had previously studied with hydrostatic models, while the Ca abundances have been determined here for the first time. Methods. We used a modified version of the spectral synthesis code Turbospectrum and consider the presence of a gaseous circumstellar envelope and radial wind in the modelling of the spectra of these massive AGB stars. The Li and Ca abundances were obtained from the 6708 Å Li I and 6463 Å Ca I resonance lines, respectively. In addition, we studied the sensitivity of the pseudo-dynamical models to variations of the stellar and wind parameters. Results. The Li abundances derived with the pseudo-dynamical models are very similar to those obtained from hydrostatic models (the average difference is 0.18 dex, σ2 = 0.02), with no difference for Ca. This indicates that the Li and Ca content in these stars is only slightly affected by the presence of a circumstellar envelope. We also found that the Li I and Ca I line profiles are not very sensitive to variations of the model wind parameters. Conclusions. The new Li abundances confirm the Li-rich (and super Li-rich, in some cases) nature of the sample stars, supporting the activation of hot bottom burning in massive Galactic AGB stars. This is in good agreement with the theoretical predictions for solar metallicity AGB models from ATON, Monash, and NuGrid/MESA but is at odds with the FRUITY database, which predicts no hot bottom burning leading to the production of Li. Most (20) sample stars display nearly solar (within the estimated errors and considering possible non-local thermodynamic equilibrium effects) Ca abundances that are consistent with the available s-process nucleosynthesis models for solar metallicity massive AGB stars, which predict overproduction of 46Ca relatively to the other Ca isotope and the creation of the radioactive isotope 41Ca (half life of 0.1 Myr) but no change in the total Ca abundance. A minority (five) of the sample stars seem to show a significant Ca depletion (by up to 1.0 dex). Possible explanations are offered to explain their apparent and unexpected Ca depletion. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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- View/download PDF
17. Analysis and forecast of performance characteristics of combine harvesters.
- Author
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Zubko, V., Roubik, H., Zamora, O., and Khvorost, T.
- Subjects
COMBINES (Agricultural machinery) ,HARVESTING machinery ,WHEAT harvesting ,WINTER wheat ,PLANT residues - Abstract
This article presents results of an experimental research of qualitative indicators of the modern combine harvesters (Case IH Axil Flow 8230, MasseyFergusonMFT7, JohnDeereS680i, ClaasLexion760, NewHolland CR9.80) used for winter wheat harvesting. Based on the results obtained, determination was made regarding the productivity of combine harvesters on the field, fuel consumption, and field conditions influence the grain loss and grain damage caused by a harvester. When conducting the experimental research of a combine's performance on the field, a study of the effectiveness of the combine JohnDeereS680i was made on different modes. A program 'Machine Unit', designed by the authors, was used for the determination of productivity, fuel consumption and quality indicator for harvesting. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
18. StarHorse: a Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars.
- Author
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Queiroz, A. B. A., Anders, F., Santiago, B. X., Chiappini, C., Steinmetz, M., Dal Ponte, M., Stassun, K. G., da Costa, L. N., Maia, M. A. G., Crestani, J., Beers, T. C., Fernández-Trincado, J. G., García-Hernández, D. A., Roman-Lopes, A., and Zamora, O.
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STELLAR mass ,AGE of stars ,STELLAR parallax ,GALACTIC evolution ,GALAXY formation ,BAYESIAN analysis - Abstract
Understanding the formation and evolution of our Galaxy requires accurate distances, ages, and chemistry for large populations of field stars. Here, we present several updates to our spectrophotometric distance code, which can now also be used to estimate ages, masses, and extinctions for individual stars. Given a set of measured spectrophotometric parameters, we calculate the posterior probability distribution over a given grid of stellar evolutionary models, using flexible Galactic stellar-population priors. The code (called StarHorse) can accommodate different observational data sets, prior options, partially missing data, and the inclusion of parallax information into the estimated probabilities. We validate the code using a variety of simulated stars as well as real stars with parameters determined from asteroseismology, eclipsing binaries, and isochrone fits to star clusters. Our main goal in this validation process is to test the applicability of the code to field stars with known Gaia-like parallaxes. The typical internal precisions (obtained from realistic simulations of an APOGEE+Gaia-like sample) are ≃8 per cent in distance, ≃20 per cent in age, ≃6 per cent in mass, and ≃0.04 mag in A
V . The median external precision (derived from comparisons with earlier work for real stars) varies with the sample used, but lies in the range of ≃[0, 2] per cent for distances, ≃[12, 31] per cent for ages, ≃[4, 12] per cent for masses, and ≃ 0.07 mag for AV . We provide StarHorse distances and extinctions for the APOGEE DR14, RAVE DR5, GES DR3, and GALAH DR1 catalogues. [ABSTRACT FROM AUTHOR]- Published
- 2018
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- View/download PDF
19. A view of the H-band light-element chemical patterns in globular clusters under the AGB self-enrichment scenario.
- Author
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Dell'Agli, F., García-Hernández, D. A., Ventura, P., Mészáros, Sz., Masseron, T., Fernández-Trincado, J. G., Tang, B., Shetrone, M., Zamora, O., and Lucatello, S.
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ASYMPTOTIC giant branch stars ,GLOBULAR clusters ,STELLAR populations ,STAR formation ,ASTRONOMICAL observations ,INTERSTELLAR medium - Abstract
We discuss the self-enrichment scenario by asymptotic giant branch (AGB) stars for the formation of multiple populations in globular clusters (GCs) by analysing data set of giant stars observed in nine Galactic GCs, covering a wide range of metallicities and for which the simultaneous measurements of C, N, O, Mg, Al, and Si are available. To this aim, we calculated six sets of AGB models, with the same chemical composition as the stars belonging to the first generation of each GC. We find that the AGB yields can reproduce the set of observations available, not only in terms of the degree of contamination shown by stars in each GC but, more important, also the observed trend with metallicity, which agrees well with the predictions from AGB evolution modelling. While further observational evidences are required to definitively fix the main actors in the pollution of the interstellar medium from which new generation of stars formed in GCs, the present results confirm that the gas ejected by stars of mass in the range 4M☉ ≤ M ≤ 8M☉ during the AGB phase share the same chemical patterns traced by stars in GCs. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
20. Rubidium and zirconium abundances in massive Galactic asymptotic giant branch stars revisited.
- Author
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Pérez-Mesa, V., Zamora, O., García-Hernández, D. A., Plez, B., Manchado, A., Karakas, A. I., and Lugaro, M.
- Abstract
Context. Luminous Galactic OH/IR stars have been identified as massive (>4–5 M ⊙) asymptotic giant branch (AGB) stars experiencing hot bottom burning and Li production. Their Rb abundances and [Rb/Zr] ratios, as derived from classical hydrostatic model atmospheres, are significantly higher than predictions from AGB nucleosynthesis models, posing a problem for our understanding of AGB evolution and nucleosynthesis. Aims. We report new Rb and Zr abundances in the full sample (21) of massive Galactic AGB stars, previously studied with hydrostatic models, by using more realistic extended model atmospheres. Methods. For this, we use a modified version of the spectral synthesis code Turbospectrum and consider the presence of a circumstellar envelope and radial wind in the modelling of the optical spectra of these massive AGB stars. The Rb and Zr abundances are determined from the 7800 Å Rb I resonant line and the 6474 Å ZrO bandhead, respectively, and we explore the sensitivity of the derived abundances to variations of the stellar (Teff) and wind (M˙ , β and vexp) parameters in the pseudo-dynamical models. The Rb and Zr abundances derived from the best spectral fits are compared with the most recent AGB nucleosynthesis theoretical predictions. Results. The Rb abundances derived with the pseudo-dynamical models are much lower (in the most extreme stars even by ∼1–2 dex) than those derived with the hydrostatic models, while the Zr abundances are similar. The Rb I line profile and Rb abundance are very sensitive to the wind mass-loss rate M˙ (especially for M˙ ≥ 10−8 M ⊙yr−1) but much less sensitive to variations of the wind velocity-law (β parameter) and the expansion velocity vexp(OH). Conclusions. We confirm the earlier preliminary results based on a smaller sample of massive O-rich AGB stars, suggesting that the use of extended atmosphere models can solve the discrepancy between the AGB nucleosynthesis theoretical models and the observations of Galactic massive AGB stars. The Rb abundances, however, are still strongly dependent on the wind mass-loss M˙ , which, unfortunately, is unknown in these AGB stars. Accurate mass-loss rates M˙ (e.g. from rotationally excited lines of the CO isotopologues in the radio domain) in these massive Galactic AGB stars are needed in order to break the model’s degeneracy and obtain reliable (non-model-dependent) Rb abundances in these stars. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
21. Studying the evolution of AGB stars in the Gaia epoch.
- Author
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Di Criscienzo, M., Ventura, P., García-Hernández, D. A., Dell'Agli, F., Castellani, M., Marrese, P. M., Marinoni, S., Giuffrida, G., and Zamora, O.
- Subjects
ASYMPTOTIC giant branch stars ,GALACTIC evolution ,ASTRONOMICAL observations ,STELLAR mass ,INTERSTELLAR medium - Abstract
We present asymptotic giant branch (AGB) models of solar metallicity, to allow the interpretation of observations of Galactic AGB stars, whose distances should be soon available after the first release of the Gaia catalogue. We find an abrupt change in the AGB physical and chemical properties, occurring at the threshold mass to ignite hot bottom burning, i.e. 3.5M
⊙ . Stars with mass below 3.5M⊙ reach the C-star stage and eject into the interstellar medium gas enriched in carbon, nitrogen and17 O. The higher mass counterparts evolve at large luminosities, between 3 × 104 and 105 L⊙ . The mass expelled from the massive AGB stars shows the imprinting of proton-capture nucleosynthesis, with considerable production of nitrogen and sodium and destruction of12 C and18 O. The comparison with the most recent results from other research groups is discussed, to evaluate the robustness of the present findings. Finally, we compare the models with recent observations of galactic AGB stars, outlining the possibility offered by Gaia to shed new light on the evolution properties of this class of objects. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
22. Fate of atrazine in a soil under different agronomic management practices.
- Author
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Prado, B., Fuentes, M., Verhulst, N., Govaerts, B., De León, F., and Zamora, O.
- Subjects
AGRONOMY ,CROP rotation ,ATRAZINE ,SOIL leaching ,GROUNDWATER ,ADSORPTION (Chemistry) ,HUMUS - Abstract
Agricultural management affects the movement of atrazine in soil and leaching to groundwater. The objective of this study was to determine atrazine adsorption in a soil after 20 years of atrazine application under agronomic management practices differing in tillage practice (conventional and zero tillage), residue management (with and without residue retention) and crop rotation (wheat-maize rotation and maize monoculture). Atrazine sorption was determined using batch and column experiments. In the batch experiment, the highest distribution coefficientKd(1.1 L kg−1) at 0–10 cm soil depth was observed under zero tillage, crop rotation and residue retention (conservation agriculture). The key factor in adsorption was soil organic matter content and type. This was confirmed in the column experiment, in which the highestKdvalues were observed in treatments with residue retention, under either zero or conventional tillage (0.81 and 0.68 L kg−1, respectively). Under zero tillage, the fact that there was no soil movement helped to increase theKd. The increased soil organic matter content with conservation agriculture may be more important than preferential flow due to higher pore connectivity in the same system. The soil's capacity to adsorb 2-hydroxyatrazine (HA), an important atrazine metabolite, was more important than its capacity to adsorb atrazine, and was similar under all four management practices (Kdranged from 30 to 40 L kg−1). The HA adsorption was attributed to the type and amount of clay in the soil, which is unaffected by agronomic management. Soils under conservation agriculture had higher atrazine retention potential than soils under conventional tillage, the system that predominates in the study area. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
23. Circumstellar effects on the Rb abundances in O-rich AGB stars.
- Author
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Zamora, O., García-Hernández, D. A., Plez, B., and Manchado, A.
- Subjects
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ASYMPTOTIC giant branch stars , *CIRCUMSTELLAR matter , *STELLAR evolution , *STELLAR atmospheres , *SOLAR system , *COMPACT objects (Astronomy) - Abstract
For the first time we explore the circumstellar effects on the Rb (and Zr) abundance determination in O-rich asymptotic giant branch (AGB) stars by considering the presence of a gaseous circumstellar envelope with a radial wind. A modified version of the spectral synthesis code Turbospectrum was used to deal with extended atmosphere models and velocity fields. The Rb and Zr abundances were determined from the resonant 7800 Å Rb I line and the 6474 Å ZrO bandhead, respectively, in five representative O-rich AGB stars with different expansion velocities and metallicities. By using our new dynamical models, the Rb I line profile (photospheric and circumstellar components) is very well reproduced. Interestingly, the derived Rb abundances are much lower (by 1-2 dex) in those O-rich AGB stars showing the higher circumstellar expansion velocities. The Zr abundances, however, remain close to the solar values. The Rb abundances and [Rb/Zr] ratios derived here significantly resolve the problem of the present mismatch between the observations of intermediate-mass (4-8 M☉) Rb-rich AGB stars and the AGB nucleosynthesis theoretical predictions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
24. ISOLATION AND SELECTION OF ETHANOL-RESISTANT AND OSMOTOLERANT YEASTS FROM REGIONAL AGRICULTURAL SOURCES IN MEXICO.
- Author
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ORTIZ-ZAMORA, O., CORTÉS-GARCÍA, R., RAMÍREZ-LEPE, M., GÓMEZ-RODRÍGUEZ, J., and AGUILAR-USCANGA, M. G.
- Subjects
YEAST ,AGRICULTURE ,FERMENTATION ,EDIBLE fungi - Abstract
In Mexican alcohol distilleries using sugarcane molasses, one reason for low alcoholic fermentation efficiency is the use of inferior yeast cultures. The objective of the present study was to isolate and select yeast strains from alcoholic fermentations of natural sources (sugarcane molasses, grape juice, cane juice and pineapple) from Veracruz city market and Mexican distilleries, and to evaluate their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Ethanol production, glucose composition, growth rate, “Killer” activity, ethanol and glucose tolerance of the most promising strains were monitored on synthetic and molasses media. A total of 112 yeast strains were isolated by their capacity to produce ethanol, and from these, only 58 were selected on the basis of best ethanol theoretical yields (88–96%). These strains were exposed several times to high concentrations of glucose and ethanol in order to select ethanol- and glucose-tolerant yeast; 10 were obtained that adapted best to these conditions and that showed “Killer” activity. Of these strains, U3-11, M11, JC10 and U2-10 (obtained from grape juice, sugarcane molasses and cane juice) demonstrated the highest adaptation to both ethanol (5–7% w/v) and glucose (20% w/v). The maximum yield obtained was 0.46 g/g (90% theoretical yield) in a 20-L bioreactor with cane molasses under nonsterile conditions. PRACTICAL APPLICATIONS The selected yeasts could be introduced into industrial processes in Mexican distilleries using sugarcane molasses in order to improve productivity and diminish contamination problems. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
25. PHYSICAL CHARACTERIZATION OF 2020 AV2, THE FIRST KNOWN ASTEROID ORBITING INSIDE VENUS' ORBIT.
- Author
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Popescu, M., Vaduvescu, O., de León, J., de la Fuente Marcos, C., de la Fuente Marcos, R., Licandro, J., Pinter, V., Zamora, O., Fariña, C., and Curelaru, L.
- Subjects
ASTEROID orbits ,VENUS (Planet) ,ASTEROIDS ,NEAR-earth asteroids ,OPTICAL telescopes ,ORBIT determination - Published
- 2021
26. Comparison of the Antibody Response in Adult Cattle Against Different Epitopes of Brucella abortus Lipopolysaccharide.
- Author
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Rojas, N., Zamora, O., Cascante, J., Garita, D., and Moreno, E.
- Subjects
- *
CATTLE , *BRUCELLA abortus , *ENDOTOXINS - Abstract
The comparison of serological responses in a sample of adult, vaccinated and field-infected bovines with Brucella abortus is reported. Indirect enzyme immunoassay (EIA) titration curves and Western blotting tests for smooth-type lipopolysaccharide (S-LPS), rough-type LPS (R-LPS) and lipid A were performed. In the initial screening of sera, an overall prevalence of 20.5 % was found, which corresponds to a country with a high incidence of brucellosis. End-point EIA titres against LPS antigens from vaccinated and field-infected cows were not significantly different. However, the absorbance values in the titration curves were significantly higher for S-LPS as compared with the other antigens. A high correlation coefficient (r=0.933) was obtained when the titres to R-LPS versus lipid A were compared. Western blotting reactions of vaccinated and field-infected animals were indistinguishable. S-LPS, R-LPS and lipid A epitopes were recognized in a heterogeneous manner. In general, the number of bovines that reacted against LPS was higher in the field-infected group, with a stronger binding to S-LPS. Based on our observations, the vaccinated and field-infected bovines are capable of producing similar antibody responses to the Brucella main outer surface antigen, LPS. It should be emphasized that the humoral response of cattle to Brucella LPS contains significant amounts of antibodies to other antigenic moieties of this important surface molecule, which may contribute to the immunity to brucellosis. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
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27. VISIBLE SPECTROSCOPY OF NEAs IN THE FRAMEWORK OF THE ESA-SSA P3NEOI PROGRAM.
- Author
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Licandro, J., Popescu, M., Oscoz, A., de León, J., Zamora, O., and Monelli, M.
- Subjects
OPTICAL spectroscopy ,OPTICAL telescopes ,NEAR-Earth objects ,VISIBLE spectra ,ASTRONOMICAL observatories - Published
- 2021
28. On the circumstellar effects on the Li and Ca abundances in massive Galactic O-rich AGB stars.
- Author
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Pérez-Mesa, V., Zamora, O., García-Hernández, D. A., Ossorio, Y., Masseron, T., Plez, B., Manchado, A., Karakas, A. I., and Lugaro, M.
- Abstract
We explore the circumstellar effects on the Li and Ca abundances determination in a complete sample of massive Galactic AGB stars. The Li abundance is an indicator of the hot bottom burning (HBB) activation, while the total Ca abundance could be affected by overproduction of the short-lived radionuclide
41 Ca by the s -process. Li abundances were previously studied with hydrostatic models, while Ca abundances are determined here for the first time. The pseudo-dynamical abundances of Li and Ca are very similar to the hydrostatic ones, indicating that circumstellar effects are almost negligible. The new Li abundances confirm the (super-)Li-rich character of the sample Li-detected stars, supporting the HBB activation in massive Galactic AGB stars. Most sample stars display nearly solar Ca abundances that are consistent with predictions from the s-process nucleosynthesis models. A minority of the sample stars show a significant Ca depletion. Possible reasons for their (unexpected) low Ca content are given. [ABSTRACT FROM AUTHOR]- Published
- 2018
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29. El arte de la anatomía humana en las ciencias médicas.
- Author
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García, A., Puche, V., Teixeira, A., and Zamora, O.
- Published
- 2008
30. Recovery on a Drug Discrimination Learning Task After Brain Transplants: Preliminary Findings.
- Author
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Cabrera, M. López, Martinez, D. N. Velázquez, Zamora, O., Cornejo, G., Segoviano, A., Ostrosky, F., and Madrazo, I.
- Published
- 1992
31. ChemInform Abstract: Cyanamide: A Convenient Building Block to Synthesize 4-Aryl-2-cyanoimino-3,4-dihydro-1H-pyrimidine Systems via a Multicomponent Reaction.
- Author
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Hulme, R., Zamora, O. D. P., Mota, E. J., Pasten, M. A., Contreras-Rojas, R., Miranda, R., Valencia-Hernandez, I., Correa-Basurto, J., Trujillo-Ferrara, J., and Delgado, F.
- Published
- 2008
- Full Text
- View/download PDF
32. RAMSEY NUMBERS OF BERGE-HYPERGRAPHS AND RELATED STRUCTURES.
- Author
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SALIA, N., TOMPKINS, C., WANG, Z., and ZAMORA, O.
- Subjects
- *
HYPERGRAPHS , *RAMSEY numbers , *INTEGERS - Abstract
For a graph G = (V;E), a hypergraph H is called a Berge-G, denoted by BG, if there exists an injection f:E(G) → E(H) such that for every e E(G), e ⊆ f(e). Let the Ramsey number Rr(BG;BG) be the smallest integer n such that for any 2-edge-coloring of a complete r-uniform hypergraph on n vertices, there is a monochromatic Berge-G subhypergraph. In this paper, we show that the 2-color Ramsey number of Berge cliques is linear. In particular, we show that R3(BKs;BKt) = s + t - 3 for s; t ≤ 4 and max(s; t) ≤ 5 where BKn is a Berge-Kn hypergraph. We also investigate the Ramsey number of trace hypergraphs, suspension hypergraphs and expansion hypergraphs. [ABSTRACT FROM AUTHOR]
- Published
- 2019
33. THE STRUCTURE OF HYPERGRAPHS WITHOUT LONG BERGE CYCLES.
- Author
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GYŐRI, E., LEMONS, N., SALIA, N., and ZAMORA, O.
- Subjects
- *
HYPERGRAPHS - Abstract
We study the structure of r-uniform hypergraphs containing no Berge cycles of length at least k for k ≥ r, and determine that such hypergraphs have some special substructure. In particular we determine the extremal number of such hypergraphs, giving an affirmative answer to the conjectured value when k = r and giving a a simple solution to a recent result of Kostochka-Luo when k
- Published
- 2019
34. THE MAXIMUM NUMBER OF Pl COPIES IN Pk-FREE GRAPHS.
- Author
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GYŐRI, E., SALIA, N., TOMPKINS, C., and ZAMORA, O.
- Subjects
- *
MAGNITUDE (Mathematics) , *STELLAR structure - Abstract
Generalizing Turán's classical extremal problem, Alon and Shikhelman investigated the problem of maximizing the number of copies of T in an H-free graph, for a pair of graphs T and H. Whereas Alon and Shikhelman were primarily interested in determining the order of magnitude for some classes of graphs H, we focus on the case when T and H are paths, where we find asymptotic and exact results in some cases. We also consider other structures like stars and the set of cycles of length at least k, where we derive asymptotically sharp estimates. Our results generalize well-known extremal theorems of Erd}os and Gallai. [ABSTRACT FROM AUTHOR]
- Published
- 2019
35. Synthesis and import of GDP-l-fucose into the Golgi affect plant-water relations.
- Author
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Waszczak C, Yarmolinsky D, Leal Gavarrón M, Vahisalu T, Sierla M, Zamora O, Carter R, Puukko T, Sipari N, Lamminmäki A, Durner J, Ernst D, Winkler JB, Paulin L, Auvinen P, Fleming AJ, Andersson MX, Kollist H, and Kangasjärvi J
- Subjects
- Guanosine Diphosphate Fucose metabolism, Boron metabolism, Polysaccharides metabolism, Fucose metabolism, Arabidopsis metabolism
- Abstract
Land plants evolved multiple adaptations to restrict transpiration. However, the underlying molecular mechanisms are not sufficiently understood. We used an ozone-sensitivity forward genetics approach to identify Arabidopsis thaliana mutants impaired in gas exchange regulation. High water loss from detached leaves and impaired decrease of leaf conductance in response to multiple stomata-closing stimuli were identified in a mutant of MURUS1 (MUR1), an enzyme required for GDP-l-fucose biosynthesis. High water loss observed in mur1 was independent from stomatal movements and instead could be linked to metabolic defects. Plants defective in import of GDP-l-Fuc into the Golgi apparatus phenocopied the high water loss of mur1 mutants, linking this phenotype to Golgi-localized fucosylation events. However, impaired fucosylation of xyloglucan, N-linked glycans, and arabinogalactan proteins did not explain the aberrant water loss of mur1 mutants. Partial reversion of mur1 water loss phenotype by borate supplementation and high water loss observed in boron uptake mutants link mur1 gas exchange phenotypes to pleiotropic consequences of l-fucose and boron deficiency, which in turn affect mechanical and morphological properties of stomatal complexes and whole-plant physiology. Our work emphasizes the impact of fucose metabolism and boron uptake on plant-water relations., (© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)
- Published
- 2024
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36. A role for ethylene signaling and biosynthesis in regulating and accelerating CO 2 - and abscisic acid-mediated stomatal movements in Arabidopsis.
- Author
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Azoulay-Shemer T, Schulze S, Nissan-Roda D, Bosmans K, Shapira O, Weckwerth P, Zamora O, Yarmolinsky D, Trainin T, Kollist H, Huffaker A, Rappel WJ, and Schroeder JI
- Subjects
- Abscisic Acid pharmacology, Abscisic Acid metabolism, Carbon Dioxide pharmacology, Carbon Dioxide metabolism, Ethylenes metabolism, Plant Stomata physiology, Arabidopsis metabolism, Arabidopsis Proteins genetics, Arabidopsis Proteins metabolism
- Abstract
Little is known about long-distance mesophyll-driven signals that regulate stomatal conductance. Soluble and/or vapor-phase molecules have been proposed. In this study, the involvement of the gaseous signal ethylene in the modulation of stomatal conductance in Arabidopsis thaliana by CO
2 /abscisic acid (ABA) was examined. We present a diffusion model which indicates that gaseous signaling molecule/s with a shorter/direct diffusion pathway to guard cells are more probable for rapid mesophyll-dependent stomatal conductance changes. We, therefore, analyzed different Arabidopsis ethylene-signaling and biosynthesis mutants for their ethylene production and kinetics of stomatal responses to ABA/[CO2 ]-shifts. According to our research, higher [CO2 ] causes Arabidopsis rosettes to produce more ethylene. An ACC-synthase octuple mutant with reduced ethylene biosynthesis exhibits dysfunctional CO2 -induced stomatal movements. Ethylene-insensitive receptor (gain-of-function), etr1-1 and etr2-1, and signaling, ein2-5 and ein2-1, mutants showed intact stomatal responses to [CO2 ]-shifts, whereas loss-of-function ethylene receptor mutants, including etr2-3;ein4-4;ers2-3, etr1-6;etr2-3 and etr1-6, showed markedly accelerated stomatal responses to [CO2 ]-shifts. Further investigation revealed a significantly impaired stomatal closure to ABA in the ACC-synthase octuple mutant and accelerated stomatal responses in the etr1-6;etr2-3, and etr1-6, but not in the etr2-3;ein4-4;ers2-3 mutants. These findings suggest essential functions of ethylene biosynthesis and signaling components in tuning/accelerating stomatal conductance responses to CO2 and ABA., (© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)- Published
- 2023
- Full Text
- View/download PDF
37. Magnesium sulphate neuroprotection mechanism is placental mediated by inhibition of inflammation, apoptosis and oxidative stress.
- Author
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Khatib N, Ginsberg Y, Ben David C, Ross MG, Vitner D, Zipori Y, Zamora O, Weiner Z, and Beloosesky R
- Subjects
- Animals, Apoptosis, Caspase 3 metabolism, Female, Inflammation metabolism, Interleukin-6 metabolism, Lipopolysaccharides, Neuroprotection, Oxidative Stress, Placenta metabolism, Pregnancy, Rats, Rats, Sprague-Dawley, Tumor Necrosis Factor-alpha metabolism, Brain Injuries metabolism, Magnesium Sulfate pharmacology, Magnesium Sulfate therapeutic use
- Abstract
Introduction: Maternal inflammation may induce placental cytokine production resulting in fetal exposure, and development of neonatal neurologic injury. Maternal magnesium sulphate (MG) is used as neuroprotective in preventing white matter brain injury. We sought to determine whether maternal MG can prevent placental activation of inflammatory pathways associated with fetal injury., Methods: Pregnant Sprague Dawley rats at gestational day 20 (E20) (n = 24) received injections of intraperitoneal lipopolysaccharide (LPS; 500 μg/kg) or saline (SAL) at time 0. Dams were randomized to treatment with subcutaneous saline or MG for 2 h prior to and 2 h following LPS/saline injections. Four hours following first injection rats were sacrificed. Placentas were collected from all treatment groups (LPS/SAL, LPS/MG, SAL/MG, SAL/SAL). Placental Caspase 3, NF-kB p65, neuronal nitric oxide synthase (phospho-nNos) interleukin (IL)-6 and tumor necrotic factor-α (TNF-α) protein levels were determined by western blot and compared., Results: Maternal LPS at E20 significantly increased protein levels of placental caspase 3 (0.22 ± 0.01 vs. 0.12 ± 0.01 u), NFkB p65 (0.27 ± 0.01 vs. 0.10 ± 0.01 u), phospho-nNOS (0.20 ± 0.01 vs. 0.10 ± 0.01 u) as well as IL-6 and TNF-α compared to control. MG treatment to LPS dams significantly reduced all placental mediators to levels similar to SAL/SAL controls (p < 0.05)., Discussion: Maternal inflammation-induced fetal brain injury may be mediated via placental activation of inflammation, oxidative stress, and apoptotic pathways. The prevention of preterm brain injury could possibly intervene also via inhibition of one or more of these putative pathways., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
38. Genomic and Experimental Analysis of the Insecticidal Factors Secreted by the Entomopathogenic Fungus Beauveria pseudobassiana RGM 2184.
- Author
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Altimira F, Arias-Aravena M, Jian L, Real N, Correa P, González C, Godoy S, Castro JF, Zamora O, Vergara C, Vitta N, and Tapia E
- Abstract
The entomopathogenic fungus Beauveria pseudobassiana strain RGM 2184 can reach a maximum efficacy of 80% against the quarantine pest Lobesia botrana in field assays. In this study, the RGM 2184 genome was sequenced, and genome mining analyses were performed to predict the factors involved in its insecticidal activity. Additionally, the metabolic profiling of the RMG 2184 culture's supernatants was analyzed by mass spectrometry, and the insecticidal activity from one of these extracts was evaluated in Galleria mellonella larvae. The genome analysis resulted in 114 genes encoding for extracellular enzymes, four biosynthetic gene clusters reported as producers of insecticidal and bactericidal factors (oosporein, beauvericin, desmethylbassianin, and beauveriolide), 20 toxins, and at least 40 undescribed potential biocontrol factors (polyketides and nonribosomal peptides). Comparative genomic analysis revealed that 65-95% of these genes are Beauveria genus-specific. Metabolic profiling of supernatant extracts from RGM 2184 cultures exhibited secondary metabolites such as beauveriolide, oosporein, inflatin C, and bassiatin. However, a number of detected metabolites still remain undescribed. The metabolite extract caused 79% mortality of Galleria mellonella larvae at 28 days. The results of this research lay the groundwork for the study of new insecticidal molecules.
- Published
- 2022
- Full Text
- View/download PDF
39. Jasmonic acid and salicylic acid play minor roles in stomatal regulation by CO 2 , abscisic acid, darkness, vapor pressure deficit and ozone.
- Author
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Zamora O, Schulze S, Azoulay-Shemer T, Parik H, Unt J, Brosché M, Schroeder JI, Yarmolinsky D, and Kollist H
- Subjects
- Arabidopsis genetics, Arabidopsis radiation effects, Darkness, Environment, Light, Solanum lycopersicum genetics, Solanum lycopersicum radiation effects, Mutation, Ozone, Plant Stomata genetics, Plant Stomata physiology, Plant Stomata radiation effects, Vapor Pressure, Abscisic Acid metabolism, Arabidopsis physiology, Carbon Dioxide metabolism, Cyclopentanes metabolism, Solanum lycopersicum physiology, Oxylipins metabolism, Plant Growth Regulators metabolism, Salicylic Acid metabolism
- Abstract
Jasmonic acid (JA) and salicylic acid (SA) regulate stomatal closure, preventing pathogen invasion into plants. However, to what extent abscisic acid (ABA), SA and JA interact, and what the roles of SA and JA are in stomatal responses to environmental cues, remains unclear. Here, by using intact plant gas-exchange measurements in JA and SA single and double mutants, we show that stomatal responsiveness to CO
2 , light intensity, ABA, high vapor pressure deficit and ozone either did not or, for some stimuli only, very slightly depended upon JA and SA biosynthesis and signaling mutants, including dde2, sid2, coi1, jai1, myc2 and npr1 alleles. Although the stomata in the mutants studied clearly responded to ABA, CO2 , light and ozone, ABA-triggered stomatal closure in npr1-1 was slightly accelerated compared with the wild type. Stomatal reopening after ozone pulses was quicker in the coi1-16 mutant than in the wild type. In intact Arabidopsis plants, spraying with methyl-JA led to only a modest reduction in stomatal conductance 80 min after treatment, whereas ABA and CO2 induced pronounced stomatal closure within minutes. We could not document a reduction of stomatal conductance after spraying with SA. Coronatine-induced stomatal opening was initiated slowly after 1.5-2.0 h, and reached a maximum by 3 h after spraying intact plants. Our results suggest that ABA, CO2 and light are major regulators of rapid guard cell signaling, whereas JA and SA could play only minor roles in the whole-plant stomatal response to environmental cues in Arabidopsis and Solanum lycopersicum (tomato)., (© 2021 Society for Experimental Biology and John Wiley & Sons Ltd.)- Published
- 2021
- Full Text
- View/download PDF
40. Adaptive mitochondrial response of the whiteleg shrimp Litopenaeus vannamei to environmental challenges and pathogens.
- Author
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Rodriguez-Armenta C, Reyes-Zamora O, De la Re-Vega E, Sanchez-Paz A, Mendoza-Cano F, Mendez-Romero O, Gonzalez-Rios H, and Muhlia-Almazan A
- Subjects
- Animals, Calcium metabolism, Hypoxia metabolism, Mitochondrial Membranes, Permeability, Mitochondria, Penaeidae
- Abstract
In most eukaryotic organisms, mitochondrial uncoupling mechanisms control ATP synthesis and reactive oxygen species production. One such mechanism is the permeability transition of the mitochondrial inner membrane. In mammals, ischemia-reperfusion events or viral diseases may induce ionic disturbances, such as calcium overload; this cation enters the mitochondria, thereby triggering the permeability transition. This phenomenon increases inner membrane permeability, affects transmembrane potential, promotes mitochondrial swelling, and induces apoptosis. Previous studies have found that the mitochondria of some crustaceans do not exhibit a calcium-regulated permeability transition. However, in the whiteleg shrimp Litopenaeus vannamei, contradictory evidence has prevented this phenomenon from being confirmed or rejected. Both the ability of L. vannamei mitochondria to take up large quantities of calcium through a putative mitochondrial calcium uniporter with conserved characteristics and permeability transition were investigated in this study by determining mitochondrial responses to cations overload. By measuring mitochondrial swelling and transmembrane potential, we investigated whether shrimp exposure to hypoxia-reoxygenation events or viral diseases may induce mitochondrial permeability transition. The results of this study demonstrate that shrimp mitochondria take up large quantities of calcium through a canonical mitochondrial calcium uniporter. Neither calcium nor other ions were observed to promote permeability transition. This phenomenon does not depend on the life cycle stage of shrimp, and it is not induced during hypoxia/reoxygenation events or in the presence of viral diseases. The absence of the permeability transition phenomenon and its adaptive meaning are discussed as a loss with biological advantages, possibly enabling organisms to survive under harsh environmental conditions.
- Published
- 2021
- Full Text
- View/download PDF
41. Occurrence of perfluorinated carboxylic acids in Mexico City's wastewater: A monitoring study in the sewerage and a mega wastewater treatment plant.
- Author
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Rodríguez-Varela M, Durán-Álvarez JC, Jiménez-Cisneros B, Zamora O, and Prado B
- Abstract
An analytical method based on liquid chromatography coupled to mass spectrometry was validated to quantify five perfluorinated carboxylic acids (PFCA) namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), and perfluoroundecanoic acid (PFUnA), in wastewater produced in a megacity. Sampling was performed on a monthly basis, obtaining samples from the undergrounded sewerage system and the main open-air canal transporting wastewater out the city. Steady levels of the sum of the target PFCA (ƩPFCA) were determined on both sites through the study: 419.4 ± 24.3 ng L
-1 in undergrounded sewage and 591.1 ± 39 ng L-1 in the open-air canal. Short-chain PFCA (PFBA, PFHxA, and PFHpA) were abundant, while concentrations of PFOA and PFUnA remained lower in both sampling sites. The open-air canal was transected in four sampling points, which were sampled throughout the monitoring campaign, finding that furtive discharges of municipal and industrial wastewater increased the levels of short-chain PFCA, while those of PFOA and PFUnA were depleted. Relevant concentrations of PFBA (176.9 ± 3.3 ng L-1 ), PFHxA (133.4 ± 2.5 ng L-1 ), PFHpA (116.6 ± 3.9 ng L-1 ), PFOA (133.1 ± 3.5 ng L-1 ), and PFUnA (23.5 ± 6.5 ng L-1 ) were found 60 km downstream, where the wastewater transported by the open-air canal is used in irrigation. A fraction of sewage is treated in a conventional wastewater treatment plant. The concentration of short-chain PFCA increased in effluent, adding extra loads of PFBA, PFHxA, and PFHpA to the environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
42. Dissecting Contrasts in Cell Death, Hormone, and Defense Signaling in Response to Botrytis cinerea and Reactive Oxygen Species.
- Author
-
Vuorinen K, Zamora O, Vaahtera L, Overmyer K, and Brosché M
- Subjects
- Arabidopsis Proteins genetics, Arabidopsis Proteins metabolism, Reactive Oxygen Species metabolism, Stress, Physiological genetics, Arabidopsis genetics, Arabidopsis metabolism, Botrytis physiology, Cell Death, Plant Diseases microbiology, Plant Growth Regulators metabolism, Signal Transduction
- Abstract
Plants require interaction between signaling pathways to differentiate and integrate stress responses and deploy appropriate defenses. The hormones ethylene, salicylic acid (SA), and jasmonic acid (JA) are important regulators of plant defenses. Numerous interactions between these signaling pathways are the cornerstone of robust plant immunity. Additionally, during the early response to pathogens, reactive oxygen species (ROS) act as signaling molecules. Here, we examined the extent of signal interaction in the early stages of Botrytis cinerea infection. To enable a comparison between B. cinerea infection with ROS signaling, we subjected plants to ozone treatment, which stimulates an apoplastic ROS burst. We used a collection of single, double, and triple signaling mutants defective in hormone signaling and biosynthesis and subjected them to B. cinerea infection and ozone treatment at different timepoints. We examined lesion size, cell death, and gene expression (both quantitatively and spatially). The two treatments shared many similarities, especially in JA-insensitive mutants, which were sensitive to both treatments. Unexpectedly, a B. cinerea -susceptible JA-insensitive mutant ( coi1 ), became tolerant when both SA biosynthesis and signaling was impaired ( coi1 npr1 sid2 ), demonstrating that JA responses may be under the control of SA. Extensive marker gene analysis indicated JA as the main regulator of both B. cinerea and ozone defenses. In addition, we identified the transcription factor SR1 as a crucial regulator of PLANT DEFENSIN expression and cell-death regulation, which contributes to resistance to B . cinerea . Overall, our work further defines the context of ROS in plant defense signaling.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
- Published
- 2021
- Full Text
- View/download PDF
43. [Complex multiligament knee injury associated with patellar tendon rupture].
- Author
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Canales-Zamora OA, Benítez-Romero A, Mejía-Rohenes LC, Mora-Ríos FG, González-Gijón OR, and Cueva Del Castillo-Mendoza JF
- Subjects
- Adult, Humans, Knee Joint, Male, Rupture surgery, Treatment Outcome, Young Adult, Anterior Cruciate Ligament Injuries, Knee Injuries complications, Knee Injuries surgery, Patellar Ligament surgery, Tendon Injuries surgery
- Abstract
Introduction: Multi-ligament injury of the knee joint is defined as damage to two or more major ligaments. They are uncommon, with an incidence of ? 10:10,000. They constitute less than 0.02% of all orthopedic lesions. It is even less frequent to find an association of these with a complete rupture of the patellar tendon which presents with a prevalence of 2.4%., Case Report: 22 year old male; he presented a high-speed accident with a diagnosis of multi-ligament left knee injury stage V of Schenck associated with complete patellar tendon rupture treated in a single surgical time with ligament reconstruction, four weeks after traumatic event. A score of 88.5 was obtained after eight months with the IKDC 2000 form for the subjective functional evaluation of the knee., Discussion: The definitive surgical treatment is performed four weeks after the injury. This reduces the risk of instability. In our clinical case, the patient is integrated into the activities of his daily life after eight months. To validate this technique as effective or good for its use, a greater number of patients treated in the same way is required. It is, however, suggested to contemplate as a management option., Conclusion: These types of lesions are infrequent with a prognosis reserved.
- Published
- 2020
44. Phosphorus-rich stars with unusual abundances are challenging theoretical predictions.
- Author
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Masseron T, García-Hernández DA, Santoveña R, Manchado A, Zamora O, Manteiga M, and Dafonte C
- Abstract
Almost all chemical elements have been made by nucleosynthetic reactions in various kind of stars and have been accumulated along our cosmic history. Among those elements, the origin of phosphorus is of extreme interest because it is known to be essential for life such as we know on Earth. However, current models of (Galactic) chemical evolution under-predict the phosphorus we observe in our Solar System. Here we report the discovery of 15 phosphorus-rich stars with unusual overabundances of O, Mg, Si, Al, and Ce. Phosphorus-rich stars likely inherit their peculiar chemistry from another nearby stellar source but their intriguing chemical abundance pattern challenge the present stellar nucleosynthesis theoretical predictions. Specific effects such as rotation or advanced nucleosynthesis in convective-reactive regions in massive stars represent the most promising alternatives to explain the existence of phosphorus-rich stars. The phosphorus-rich stars progenitors may significantly contribute to the phosphorus present on Earth today.
- Published
- 2020
- Full Text
- View/download PDF
45. [Complications of supracondylar humeral fractures in children].
- Author
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Canales-Zamora OA, Mora-Ríos FG, Mejía-Rohenes LC, Anaya-Morales A, González-Gijón OR, and López-Hernández JR
- Subjects
- Bone Wires, Child, Humans, Range of Motion, Articular, Retrospective Studies, Humeral Fractures complications, Humeral Fractures surgery, Plastic Surgery Procedures
- Abstract
Introduction: Supracondylar fractures represent the most frequent cause of pediatric elbow injuries, at 64%, in children under eight years old. These fractures can present complications such as: A) Complications prior to treatment: 1) neurological, 2) vascular and 3) compartment syndrome. B) Complications after treatment: 1) early, in the first days after treatment: loss of reduction, neurological, vascular, compartment syndrome, infection of Kirschner wires. 2) Late complications in treatment: Angular deformity, loss of mobility, ossifying myositis, avascular necrosis of the trochlea, others., Objective: To determine the frequency of complications in humeral supracondylar fractures in less than eight years., Material and Methods: A retrospective, observational cohort study was conducted in patients under 8 years of age during the period of March 2014 to February 2018., Results: 277 patients were obtained with the following percentages: cubitus varus 3.97%, neurological lesions prior to surgical treatment 1.44%, early neurological complications to treatment 1.44%, infections of Kirschner needles 0.72%, cubitus valgus 0.72%, loss of mobility 0.36%., Conclusions: The most common complication of humerus supracondylar fractures in this study was cubitus varus and neurological complications prior to treatment.
- Published
- 2020
46. Differential role of MAX2 and strigolactones in pathogen, ozone, and stomatal responses.
- Author
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Kalliola M, Jakobson L, Davidsson P, Pennanen V, Waszczak C, Yarmolinsky D, Zamora O, Palva ET, Kariola T, Kollist H, and Brosché M
- Abstract
Strigolactones are a group of phytohormones that control developmental processes including shoot branching and various plant-environment interactions in plants. We previously showed that the strigolactone perception mutant more axillary branches 2 (max2) has increased susceptibility to plant pathogenic bacteria. Here we show that both strigolactone biosynthesis ( max3 and max4 ) and perception mutants ( max2 and dwarf14 ) are significantly more sensitive to Pseudomonas syringae DC3000. Moreover, in response to P. syringae infection, high levels of SA accumulated in max2 and this mutant was ozone sensitive. Further analysis of gene expression revealed no major role for strigolactone in regulation of defense gene expression. In contrast, guard cell function was clearly impaired in max2 and depending on the assay used, also in max3 , max4, and d14 mutants. We analyzed stomatal responses to stimuli that cause stomatal closure. While the response to abscisic acid (ABA) was not impaired in any of the mutants, the response to darkness and high CO
2 was impaired in max2 and d14-1 mutants, and to CO2 also in strigolactone synthesis ( max3 , max4 ) mutants. To position the role of MAX2 in the guard cell signaling network, max2 was crossed with mutants defective in ABA biosynthesis or signaling. This revealed that MAX2 acts in a signaling pathway that functions in parallel to the guard cell ABA signaling pathway. We propose that the impaired defense responses of max2 are related to higher stomatal conductance that allows increased entry of bacteria or air pollutants like ozone. Furthermore, as MAX2 appears to act in a specific branch of guard cell signaling (related to CO2 signaling), this protein could be one of the components that allow guard cells to distinguish between different environmental conditions., Competing Interests: The authors declare no conflict of interest associated with the work described in this manuscript., (© 2020 The Authors. Plant Direct published by American Society of Plant Biologists, Society for Experimental Biology and John Wiley & Sons Ltd.)- Published
- 2020
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47. Microencapsulation of Anthocyanin Extracted from Purple Flesh Cultivated Potatoes by Spray Drying and Its Effects on In Vitro Gastrointestinal Digestion.
- Author
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Vergara C, Pino MT, Zamora O, Parada J, Pérez R, Uribe M, and Kalazich J
- Subjects
- Color, Drug Compounding methods, Food Industry methods, Models, Biological, Polysaccharides chemistry, Anthocyanins chemistry, Plant Extracts chemistry, Solanum tuberosum chemistry
- Abstract
Purple flesh cultivated potato (PP) is a foodstuff scarcely cultivated in the world but with high potential because of its anthocyanin content. Moreover, it has been little explored as a source of anthocyanins (AT) for further applications in formulated food products. The main goal of this research was to study the effect of maltodextrin (MD) and spray drying conditions on the encapsulation efficiency (EE) and bioaccesibility of AT from purple flesh cultivated potato extract (PPE). The anthocyanin-rich extract was obtained from PP and microencapsulated by spray-drying, using MD as the encapsulating agent. A statistical optimization approach was used to obtain optimal microencapsulation conditions. The PPE microparticles obtained under optimal conditions showed 86% of EE. The protector effect of microencapsulation on AT was observed to be stable during storage and in vitro digestion. The AT degradation rate constant was significantly lower for the PPE-MD than for the PPE. The assessed bioaccesibility of AT from the PPE-MD was 20% higher than that of the PPE, which could be explained by the protective effect of encapsulation against environmental conditions. In conclusion, microencapsulation is an effective strategy to protect AT from PP, suggesting that AT may be an alternative as a stable colorant for use in the food industry.
- Published
- 2020
- Full Text
- View/download PDF
48. Production of nitrates and perchlorates by laser ablation of sodium chloride in simulated Martian atmospheres. Implications for their formation by electric discharges in dust devils.
- Author
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Martínez-Pabello PU, Navarro-González R, Walls X, Pi-Puig T, González-Chávez JL, de la Rosa JG, Molina P, and Zamora O
- Subjects
- Dust, Extraterrestrial Environment, Space Simulation, Static Electricity, Atmosphere chemistry, Mars, Nitrates chemistry, Perchlorates chemistry
- Abstract
Nitrates and perchlorates are present both on Earth and Mars. In the Martian environment perchlorates dominate over nitrates whereas on Earth is contrariwise. This implies that the mechanisms responsible for their formation are different for both planets. The chemical elements required for their formation are nitrogen and chlorine, which are present in the atmosphere and surface, respectively. Dust in the Martian atmosphere causes atmospheric perturbations that lead to the development of dust-devils and sandstorms. Dust devils contain both chemical elements simultaneously, and normally generate high electric fields that can trigger the formation of electric discharges. Here we present laboratory experiments of this phenomenon using laser ablation of a sodium chloride (NaCl) plate in two different simulated atmospheres: (1) 96% CO
2 , 2% N2 and 2% Ar; and (2) 66% CO2 , 33% N2 and 1% Ar. The dust that condensed and accumulated on the walls of the reactor was analyzed by different analytical techniques that included Fourier transform infrared spectroscopy, visible spectroscopy using azo dyes, thermogravimetry/simultaneous thermal analyses coupled to mass spectrometry, powder X-ray diffraction, and ion chromatography. The main components of the ablated dust corresponded to NaCl ≥ 91.5%, sodium nitrate (NaNO3 = 1.6-6.0%), and sodium perchlorate (NaClO4 ∼ 0.2-0.3%). It is interesting to note that these salts formed in a dry process that is relevant to Mars today. A thermochemical model was used to understand the chemical steps that led to the formation of these salts in the gas phase. The NaNO3 NaClO4 (wt/wt) ratio of this process was estimated to vary from 5.0 to 30.0; this ratio is too high compared to that found on Mars (NO3 - ClO4 - (wt/wt)) from 0.004 to 0.13). This implies that gaseous NaCl was not efficiently oxidized to perchlorate by the electric discharge process. We propose instead that gaseous metal chlorides (e.g., MgCl2 , NaCl, CaCl2 , KCl) were supplied to the atmosphere by the volatilization of chloride minerals present in the dust by electric discharges generated in dust devils and were subsequently oxidized to perchlorate by photochemical processes. Further work is required to assess the relative contribution of this possible source., (Copyright © 2019 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
49. The Lin28/Let-7 system in early human embryonic tissue and ectopic pregnancy.
- Author
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Lozoya T, Domínguez F, Romero-Ruiz A, Steffani L, Martínez S, Monterde M, Ferri B, Núñez MJ, AinhoaRomero-Espinós, Zamora O, Gurrea M, Sangiao-Alvarellos S, Vega O, Simón C, Pellicer A, and Tena-Sempere M
- Subjects
- Adult, Female, Humans, MicroRNAs genetics, Pregnancy, Pregnancy, Ectopic genetics, Pregnancy, Ectopic pathology, RNA-Binding Proteins genetics, Embryo, Mammalian metabolism, Gene Expression Regulation, Developmental, MicroRNAs metabolism, Placentation, Pregnancy, Ectopic mortality, RNA-Binding Proteins metabolism
- Abstract
Our objective was to determine the expression of the elements of the Lin28/Let-7 system, and related microRNAs (miRNAs), in early stages of human placentation and ectopic pregnancy, as a means to assess the potential role of this molecular hub in the pathogenesis of ectopic gestation. Seventeen patients suffering from tubal ectopic pregnancy (cases) and forty-three women with normal on-going gestation that desired voluntary termination of pregnancy (VTOP; controls) were recruited for the study. Embryonic tissues were subjected to RNA extraction and quantitative PCR analyses for LIN28B, Let-7a, miR-132, miR-145 and mir-323-3p were performed. Our results demonstrate that the expression of LIN28B mRNA was barely detectable in embryonic tissue from early stages of gestation and sharply increased thereafter to plateau between gestational weeks 7-9. In contrast, expression levels of Let-7, mir-132 and mir-145 were high in embryonic tissue from early gestations (≤ 6-weeks) and abruptly declined thereafter, especially for Let-7. Opposite trends were detected for mir-323-3p. Embryonic expression of LIN28B mRNA was higher in early stages (≤ 6-weeks) of ectopic pregnancy than in normal gestation. In contrast, Let-7a expression was significantly lower in early ectopic pregnancies, while miR-132 and miR-145 levels were not altered. Expression of mir-323-3p was also suppressed in ectopic embryonic tissue. We are the first to document reciprocal changes in the expression profiles of the gene encoding the RNA-binding protein, LIN28B, and the related miRNAs, Let-7a, mir-132 and mir-145, in early stages of human placentation. This finding suggests the potential involvement of LIN28B/Let-7 (de)regulated pathways in the pathophysiology of ectopic pregnancy in humans.
- Published
- 2014
- Full Text
- View/download PDF
50. Double bisection of auditory temporal intervals by humans.
- Author
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Trujano RE and Zamora O
- Subjects
- Acoustic Stimulation, Adolescent, Female, Humans, Male, Psychological Theory, Reaction Time, Young Adult, Auditory Perception physiology, Psychomotor Performance physiology, Time Perception physiology
- Abstract
Scalar Expectancy Theory (SET) has been the leading theory in timing research, and has also influenced research into human timing. However, other timing theories exist, such as Learning to Time (LeT). The double bisection task was designed to test the SET and LeT theories in pigeons. The purpose of this experiment was to verify whether similar results emerge from a human adaptation of the double bisection task. The results indicated that humans perform the double bisection task in the same way as pigeons do. However, the assumptions inherent in LeT cannot be applied to humans. Two other explanations are also assessed here.
- Published
- 2013
- Full Text
- View/download PDF
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