La restauración de Sambucus palmensis en La Gomera: Conservación genética y modelización de nicho climático

La conservación de especies vegetales amenazadas a menudo conlleva la restauración de sus poblaciones naturales, ya sea mediante el refuerzo de las poblaciones existentes, la reintroducción de poblaciones extintas o la introducción de nuevos núcleos. Antes de comenzar acciones de restauración, es esencial conocer la biología de las especies con el fin de determinar los factores más importantes que limitan el crecimiento de la población fundadora (Heywood & Iriondo, 2003

Fabric phase sorptive extraction of selected steroid hormone residues in commercial raw milk followed by ultra-high-performance liquid chromatography–tandem mass spectrometry

Hormones in edible matrices, such as milk, are a subject of concern because of their adverse effects on the endocrine system and cell signaling and the consequent disruption of homeostasis in human consumers. Therefore, the assessment of the presence of hormones in milk as potential endocrine-disrupting compounds is warranted. However, the complexity of milk as a sample matrix and the ultra-low concentration of hormones pose significant analytical challenges. Fabric phase sorptive extraction (FPSE) has emerged as a powerful analytical technique for the extraction of emerging pollutants from complex aqueous matrices. FPSE allows for substantially simplified sample handling and short extraction and desorption times, as well as the decreased use of organic solvents. It is considered a green alternative to traditional extraction methodologies. In this work, the FPSE technique was evaluated to perform the simultaneous extraction of 15 steroid hormones from raw milk without employing any sample pretreatment steps. Clean and preconcentrated hormone solutions obtained from FPSE of raw milk were analyzed using ultra-high-performance liquid chromatography–tandem mass spectrometry to achieve low detection limits, which ranged from 0.047 to 1.242 ng·mL−1. Because of the presence of many interferents in milk, such as proteins, lipids, and sugar, the effect of fat content on the extraction procedure was also thoroughly studied. Additionally, for the first time, the effect of lactose on the extraction of steroid hormones was evaluated, and the results showed that the extraction efficiencies were enhanced in lactose-free samples. Finally, the optimized methodology was applied to commercial samples of cow and goat milk, and no measurable concentrations of the studied hormones were detected in these samples

A 0.8-2.4 microns spectral atlas of Active Galactic Nuclei

Aims: We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN), of all degrees of activity, in the wavelength interval of 0.8-2.4 microns, including the fluxes of the observed emission lines. We analyze the spectroscopic properties of the continuum and emission line spectra of the sources Methods: In order to exclude aperture and seeing effects we use near-infrared spectroscopy in the short cross-dispersed mode (SXD, 0.8-2.4 microns), taking the JHK-bands spectra simultaneously. Results: We present the most extensive NIR spectral atlas of AGN to date. This atlas offers a suitable database for studying the continuum and line emission properties of these objects in a region full of interesting features. The shape of the continuum of QSOs and Seyfert 1's are similar, being essentially flat in H and K band, in the J band, a strong variation is found. In Seyfert 2 galaxies, the continuum in the F_lambda X lambda space smoothly decreases from 1.2 microns redwards in almost all sources. In J, it smoothly rises bluewards in some sources while in others a small decreased in flux is observed. The spectra are dominated by strong emission features of H I, He I, He II, [S III] and conspicuous forbidden lines of low and high ionization species. Molecular lines of H2 are common features to most objects. The absence of O I and Fe II lines in Seyfert 2 galaxies give observational support to the fact that these lines are formated in the outermost portion of the broad line region. [P II] and coronal lines are detected in all degrees of activity. The [Fe II] 12570A/16436A line ratio becomes a reliable reddening indicator for the narrow-line region of Seyfert galaxies.Comment: 39 pages, 17 figures, accepted for publication in Astronomy and Astrophysics (15/05/2006

Comparative study on the valorization of Sargassum from the Mexican Caribbean coast and Gulf of California as an ingredient on healthy diets for shrimp farming

Funding: This work received the financial support of the project GCRFNGR4/1388 "Algae bloom: waste resource for aquaculture and bioenergy industry in Mexico".Sargassum biomass is a potential ingredient for aquaculture formulations due to its high nutritional value and availability, as it contains a variety of essential nutrients including proteins, carbohydrates, lipids, vitamins, antioxidants, fiber, and minerals, which are essential for aquatic growing, development and health parameters including digestibility and immune response against diseases. Therefore, in this work, five experimental diets were formulated considering 2.5 % and 5 % levels of inclusion of Sargassum spp. from the Mexican Caribbean coasts (SC), and from the Gulf of California (SG), and one reference diet as a control. The characterization of the raw material and the proximal analysis of the five diets were evaluated according to standard reference methods. A 35-day feeding trial was conducted using juvenile Litopenaeus vannamei showed a shrimp survival rate of 97 ± 6 % (p > 0.05) on SC. Excellent weight gain (WG) performance of SC and SG diets at 2.5 % of inclusion resulted in >10 % WG compared to the control. The specific activity of amylase, lipase, trypsin, and chymotrypsin showed a significant increase by including Sargassum in diets, compared with the reference diet. Incorporating Sargassum at 2.5 % in feed formulations for shrimps showed a great opportunity to use it as an ingredient and improved production yields. The digestion and absorption parameters were represented by the enzymatic activity in which the diets based on Sargassum spp. from the Mexican Caribbean coast (SC) have resulted in the best performance.Publisher PDFPeer reviewe

Effect of immunocastration on behaviour and blood parameters (cortisol and testosterone) of Holstein bulls

To evaluate the effect that immunocastration has on behaviour, testosterone and cortisol levels of feedlot Holstein bulls, 720 intact animals aged between 7 and 8 months, weighing 232±1.19 kg were randomly assigned to two treatments: immunocastration using the Bopriva vaccine and a placebo (360 animals per treatment). The bulls were slaughtered at day 239 of treatment. Animals were vaccinated on days 1, 21, 101, and 181, and on those same days testosterone levels were measured; while cortisol, glucose and creatin kinase measurements were done on day 181 and during exanguination at slaughter. Sexual, aggressive and social behaviours were evaluated and it was found that intact bulls showed a higher average of head butts, mounting, threats, flehmen sign and sniffing (P<0.05), no differences were found for vocalisations, lowering of the head and grooming (P>0.05). Testosterone levels in intact bulls remained at 0.47ng/mL throughout the study, however, by day 181 differences (P<0.05) were observed in immunised bulls, with values of 0.22ng/mL. At slaughter, testosterone levels were 0.21 ± 0.06 ng/mL in immunocastrated bulls and 0.54 ± 0.06 ng/mL in the placebo group. The use of immunocastration with Bopriva has shown to be effective to reduce testosterone, sexual and aggressive behaviours on Holstein bulls

Bottom-Water Conditions in a Marine Basin after the Cretaceous–Paleogene Impact Event: Timing the Recovery of Oxygen Levels and Productivity

An ultra-high-resolution analysis of major and trace element contents from the Cretaceous–Paleogene boundary interval in the Caravaca section, southeast Spain, reveals a quick recovery of depositional conditions after the impact event. Enrichment/depletion profiles of redox sensitive elements indicate significant geochemical anomalies just within the boundary ejecta layer, supporting an instantaneous recovery –some 102 years– of pre-impact conditions in terms of oxygenation. Geochemical redox proxies point to oxygen levels comparable to those at the end of the Cretaceous shortly after impact, which is further evidenced by the contemporary macrobenthic colonization of opportunistic tracemakers. Recovery of the oxygen conditions was therefore several orders shorter than traditional proposals (104–105 years), suggesting a probable rapid recovery of deep-sea ecosystems at bottom and in intermediate waters.This research was supported by Projects CGL2009-07603, CGL2008-03007, CGL2012-33281 and CGL2012-32659 (Secretaría de Estado de I+D+I, Spain), Projects RNM-3715 and RNM 05212, and Research Groups RNM-178 and 0179 (Junta de Andalucía)