11 research outputs found

    Probing the earliest phases in the formation of massive galaxies with simulated HST+JWST imaging data from Illustris

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    We use the Illustris-1 simulation to explore the capabilities of the Hubble\textit{Hubble} and James Webb Space Telescope\textit{James Webb Space Telescope} data to analyze the stellar populations in high-redshift galaxies, taking advantage of the combined depth, spatial resolution, and wavelength coverage. For that purpose, we use simulated broad-band ACS, WFC3 and NIRCam data and 2-dimensional stellar population synthesis (2D-SPS) to derive the integrated star formation history (SFH) of massive (M>1010_{\ast}>10^{10}\,M_{\odot}) simulated galaxies at 11011110^{11}\,M_{\odot} galaxy. In particular, we explore the potential of HST and JWST datasets reaching a depth similar to those of the CANDELS and ongoing CEERS observations, respectively, and concentrate on determining the capabilities of this dataset for characterizing the first episodes in the SFH of local M>1011_{\ast}>10^{11}\,M_{\odot} galaxies by studying their progenitors at z>1z>1. The 2D-SPS method presented in this paper has been calibrated to robustly recover the cosmic times when the first star formation episodes occurred in massive galaxies, i.e., the first stages in their integrated SFHs. In particular, we discuss the times when the first 1% to 50% of their total stellar mass formed in the simulation. We demonstrate that we can recover these ages with typical median systematic offset of less than 5% and scatter around 20%-30%. According to our measurements on Illustris data, we are able to recover that local M>1011_{\ast}>10^{11}\,M_{\odot} galaxies would have started their formation by z=16z=16, forming the first 5% of their stellar mass present at z1z \sim 1 by z=4.5z=4.5, 10% by z=3.7z=3.7, and 25% by z=2.7z=2.7.Comment: 28 pages, 13 figures, 4 tables. ApJ in press. Summary of changes from original submission: the major change is that we now include in Sec. 6 the comparison of the results obtained for our sample of massive 1 < z < 4 progenitors with those obtained by considering all massive galaxies at 1 < z < 4 in the simulated images. Several figures and sections have been update

    Life beyond 30: Probing the −20 < M UV < −17 Luminosity Function at 8 < z < 13 with the NIRCam Parallel Field of the MIRI Deep Survey

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    We present the ultraviolet luminosity function and an estimate of the cosmic star formation rate density at 8 8 galaxy candidates based on their dropout nature in the F115W and/or F150W filters, a high probability for their photometric redshifts, estimated with three different codes, being at z > 8, good fits based on χ2 calculations, and predominant solutions compared to z < 8 alternatives. We find mild evolution in the luminosity function from z ∼ 13 to z ∼ 8, i.e., only a small increase in the average number density of ∼0.2 dex, while the faint-end slope and absolute magnitude of the knee remain approximately constant, with values α = − 2.2 ± 0.1, and M* = − 20.8 ± 0.2 mag. Comparing our results with the predictions of state-of-the-art galaxy evolution models, we find two main results: (1) a slower increase with time in the cosmic star formation rate density compared to a steeper rise predicted by models; (2) nearly a factor of 10 higher star formation activity concentrated in scales around 2 kpc in galaxies with stellar masses ∼108M⊙ during the first 350 Myr of the universe, z ∼ 12, with models matching better the luminosity density observational estimations ∼150 Myr later, by z ∼ 9

    Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

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    Teoría de la educación : educación y cultura en la sociedad de la información

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    Resumen basado en el de la publicaciónSe configura una metodología docente integrada en las demandas y necesidades del Espacio Europeo de Educación Superior (EEES), en el que el alumno debe adquirir competencias profesionales que le garanticen la inserción laboral tras la finalización de sus estudios. Se propone para ello un modelo de juego de rol de carácter interdisciplinar basado en la participación y colaboración de profesores de diferentes áreas de conocimiento y de alumnos de distintos títulos de grado. Este modelo ofrece al docente una guía que facilita el diseño y desarrollo de juegos de rol, cuyo objetivo es la adquisición y puesta en práctica de competencias genéricas y específicas de los nuevos planes de estudio involucrados. El uso de una metodología activa en las aulas implica la dinamización de la docencia presencial -porque el juego es un elemento que invita a la participación y motivación del estudiante-, cumpliéndose con ello uno de los objetivos principales: enseñar al alumno a aprender a aprender, simulando situaciones casi realales en el contexto académico.Castilla y LeónES

    Polyunsaturated fatty acids and child neurodevelopment among a population exposed to DDT: a cohort study

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    Abstract Background Child neurodevelopment has been positively linked to maternal intake of polyunsaturated fatty acids (PUFAs) during pregnancy; however, it is unknown if that relationship persists among populations exposed to environmental neurotoxicants. Objective The aim of this work was to assess whether maternal dietary intake of PUFAs during pregnancy is positively associated with child neurodevelopment, whose mothers were environmentally exposed to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT). Methods A prospective cohort study with 276 mother–child pairs was performed in Mexico. Neurodevelopment was assessed by Bayley Scales II from children age 1 to 30 months. Dietary PUFAs intake was estimated by Food Frequency Questionnaire at 1st and 3rd trimester of pregnancy. DDE (1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene, the main metabolite of DDT) maternal serum levels were determined by electron capture gas chromatography. Longitudinal multivariate linear mixed-effects analysis, which combines mental (MDI) and motor (PDI) Bayley scales in a single model, were performed. Results Our results show that in a sample environmentally exposed to DDT, maternal ingestion of DPA during the first trimester of pregnancy was positively associated with MDI (β = 0.10, 95% CI 0.02, 0.18) in children from 1 to 30 months. Likewise, our results suggest that dietary ALA may be also related to MDI. Conclusion DPA may benefit neurodevelopment even in populations exposed to DDT. Our results strengthen the importance of PUFAs intake during the prenatal period

    Ventajas del uso de citrato respecto al acetato como estabilizante en el líquido de hemodiálisis: estudio aleatorizado ABC-treat.

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    Hemodialysis (HD) with bicarbonate dialysis fluid (DF) requires the presence of an acid to prevent the precipitation of calcium and magnesium carbonate. The most used acid is acetic acid, with it several complications have been described. In a previous work, we described the acute changes during an HD session with a DF with citrate instead of acetate. Now, we report the results in the medium term, 16 weeks. It is a prospective, multicenter, crossover and randomized study, where 56 HD patients with bicarbonate three times a week were dialysed for 16 weeks with 3mmol/L acetate and 16 weeks with 1mmol/L citrate. Patients older than 18 years with a previous stay on HD of more than 3 months and with a normal functioning arteriovenous fistula were included. Epidemiological data, dialysis, bioimpedance, biochemistry before and after HD, as well as hypotensive episodes, were collected monthly. After 16 weeks of citrate treatment, pre-HD ionic calcium and magnesium were significantly lower and paratiroid hormone (PTH) higher than in the acetate period. No differences were observed in the effectiveness of dialysis. Hypotensive episodes were significantly more frequent with acetate than with citrate: 311 (14.1%) vs 238 (10.8%) sessions. The lean mass index increased by 0.96±2.33kg/m2 when patients switched from DF with acetate to citrate. HD with citrate modifies several parameters of bone mineral metabolism, not only acutely as previously described, but also in the long-term. The substitution of acetate for citrate improves hemodynamic stability, producing less hypotension and can improve nutritional status

    Estudio prospectivo aleatorizado multicéntrico para demostrar los beneficios de la hemodiálisis sin acetato (con citrato): Estudio ABC-treat. Efecto agudo del citrato.

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    Dialysis fluid (DF), an essential element in hemodialysis (HD), is manufactured in situ by mixing three components: treated water, bicarbonate concentrate and acid concentrate. To avoid the precipitation of calcium and magnesium carbonate that is produced in DF by the addition of bicarbonate, it is necessary to add an acid. There are 2 acid concentrates that contain acetate (ADF) or citrate (CDF) as a stabilizer. To compare the acute effect of HD with CDF vs. ADF on the metabolism of calcium, phosphorus and magnesium, acid base balance, coagulation, inflammation and hemodynamic stability. Prospective, multicenter, randomized and crossed study, of 32 weeks duration, in patients in three-week HD, AK-200-Ultra-S or Artis monitor, 16 weeks with ADF SoftPac®, prepared with 3mmol/L of acetate, and 16 weeks with CDF SelectBag Citrate®, with 1mmol/L of citrate. Patients older than 18 years were included in HD for a minimum of 3 months by arteriovenous fistula. Epidemiological, dialysis, pre and postdialysis biochemistry, episodes of arterial hypotension, and coagulation scores were collected monthly during the 8 months of the study. Pre and post-dialysis analysis were extracted: venous blood gas, calcium (Ca), ionic calcium (Cai), phosphorus (P), magnesium (Mg) and parathyroid hormone (PTH) among others. ClinicalTrials.gov NCT03319680. We included 56 patients, 47 (84%) men and 9 (16%) women, mean age: 65.3 (16.4) years, technique HD/HDF: 20 (35.7%)/36 (64.3%). We found differences (p Dialysis with citrate acutely produces less postdialysis alkalemia and significantly modifies Ca, Mg and PTH. CDF has a positive impact on hemodynamic tolerance

    Life beyond 30: probing the 20<MUV<17-20<M_\mathrm{UV}<-17 luminosity function at 8<z<138<z<13 with the NIRCam parallel field of the MIRI Deep Survey

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    International audienceWe present the ultraviolet luminosity function and an estimate of the cosmic star formation rate density at 8888 galaxy candidates based on their dropout nature in the F115WF115W and/or F150WF150W filters, a high probability for their photometric redshifts, estimated with three different codes, being at z>8z>8, good fits based on χ2\chi^2 calculations, and predominant solutions compared to z<8z<8 alternatives. We find mild evolution in the luminosity function from z13z\sim13 to z8z\sim8, i.e., only a small increase in the average number density of \sim0.2~dex, while the faint-end slope and absolute magnitude of the knee remain approximately constant, with values α=2.3±0.2\alpha=-2.3\pm0.2 and M=20.8±0.2M^*=-20.8\pm0.2~mag. Comparing our results with the predictions of a wide range of state-of-the-art galaxy evolution models, we find two main results: (1) a slower increase with time in the cosmic star formation rate density compared to a steeper rise predicted by models; (2) nearly a factor of 10 higher star formation activity concentrated in scales around 2~kpc in galaxies with stellar masses 108\sim10^8~M_\odot during the first 350~Myr of the Universe (z12z\sim12), with models matching better the observations \sim150~Myr later, by z9z\sim9

    Life beyond 30: Probing the −20 < MUV < −17 Luminosity Function at 8 < z < 13 with the NIRCam Parallel Field of the MIRI Deep Survey

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    We present the ultraviolet luminosity function and an estimate of the cosmic star formation rate density at 8 8 galaxy candidates based on their dropout nature in the F115W and/or F150W filters, a high probability for their photometric redshifts, estimated with three different codes, being at z > 8, good fits based on χ 2 calculations, and predominant solutions compared to z < 8 alternatives. We find mild evolution in the luminosity function from z ∼ 13 to z ∼ 8, i.e., only a small increase in the average number density of ∼0.2 dex, while the faint-end slope and absolute magnitude of the knee remain approximately constant, with values α = − 2.2 ± 0.1, and M * = − 20.8 ± 0.2 mag. Comparing our results with the predictions of state-of-the-art galaxy evolution models, we find two main results: (1) a slower increase with time in the cosmic star formation rate density compared to a steeper rise predicted by models; (2) nearly a factor of 10 higher star formation activity concentrated in scales around 2 kpc in galaxies with stellar masses ∼108 M ⊙ during the first 350 Myr of the universe, z ∼ 12, with models matching better the luminosity density observational estimations ∼150 Myr later, by z ∼ 9.</p
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