Submillimeter H2O masers in water-fountain nebulae

We report the first detection of submillimeter water maser emission toward water-fountain nebulae, which are post-AGB stars that exhibit high-velocity water masers. Using APEX we found emission in the ortho-H2O (10_29-9_36) transition at 321.226 GHz toward three sources: IRAS 15445-5449, IRAS 18043-2116 and IRAS 18286-0959. Similarly to the 22 GHz masers, the submillimeter water masers are expanding with a velocity larger than that of the OH masers, suggesting that these masers also originate in fast bipolar outflows. In IRAS 18043-2116 and IRAS 18286-0959, which figure among the sources with the fastest water masers, the velocity range of the 321 GHz masers coincides with that of the 22 GHz masers, indicating that they likely coexist. Towards IRAS 15445-5449 the submillimeter masers appear in a different velocity range, indicating that they are tracing different regions. The intensity of the submillimeter masers is comparable to that of the 22 GHz masers, implying that the kinetic temperature of the region where the masers originate should be Tk > 1000 K. We propose that the passage of two shocks through the same gas can create the conditions necessary to explain the presence of strong high-velocity 321 GHz masers coexisting with the 22 GHz masers in the same region.Comment: 4 pages, 1 figure. Accepted for publication in A&A Letter

Screening of pesticides and polycyclic aromatic hydrocarbons in feeds and fish tissues by gas chromatography coupled to high-resolution mass spectrometry using atmospheric pressure chemical ionization

This paper reports a wide-scope screening for detection and identification of pesticides and polycyclic aromatic hydrocarbons (PAHs) in feeds and fish tissues. QuEChERS sample treatment was applied, using freezing as an additional cleanup. Analysis was carried out by gas chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry with atmospheric pressure chemical ionization (GC-(APCI) QTOF MS). The qualitative validation was performed for over 133 representative pesticides and 24 PAHs at 0.01 and 0.05 mg/kg. Subsequent application of the screening method to aquaculture samples made it possible to detect several compounds from the target list, such as chlorpyrifos-methyl, pirimiphos-methyl, and ethoxyquin, among others. Light PAHs (≤4 rings) were found in both animal and vegetable samples. The reliable identification of the compounds was supported by accurate mass measurements and the presence of at least two representative m/z ions in the spectrum together with the retention time of the peak, in agreement with the reference standard. Additionally, the search was widened to include other pesticides for which standards were not available, thanks to the expected presence of the protonated molecule and/or molecular ion in the APCI spectra. This could allow the detection and tentative identification of other pesticides different from those included in the validated target list. © 2014 American Chemical Society.This work has been (partly) funded under the EU Seventh Framework Programme by ARRAINA Project 288925: Advanced Research Initiatives for Nutrition and Aquaculture. The views expressed in this work are the sole responsibility of the authors and do not necessarily reflect the views of the European Commission. This work has been developed within the framework of the Research Unit of Marine Ecotoxicology (IATS (CSIC)-IUPA (UJI)). We also acknowledge the financial support of Generalitat Valenciana (research group of excellence PROMETEO/2009/054; ISIC 2012/016).Peer Reviewe

Occurrence and potential transfer of mycotoxins in gilthead sea bream and Atlantic salmon by use of novel alternative feed ingredients

Plant ingredients and processed animal proteins (PAP) are suitable alternative feedstuffs for fish feeds in aquaculture practice, although their use can introduce contaminants that are not previously associated with marine salmon and gilthead sea bream farming. Mycotoxins are well known natural contaminants in plant feed material, although they also could be present on PAPs after fungi growth during storage. The present study surveyed commercially available plant ingredients (19) and PAP (19) for a wide range of mycotoxins (18) according to the EU regulations. PAP showed only minor levels of ochratoxin A and fumonisin B1 and the mycotoxin carry-over from feeds to fillets of farmed Atlantic salmon and gilthead sea bream (two main species of European aquaculture) was performed with plant ingredient based diets. Deoxynivalenol was the most prevalent mycotoxin in wheat, wheat gluten and corn gluten cereals with levels ranging from 17 to 814 and μgkg-1, followed by fumonisins in corn products (range 11.1-4901μgkg-1 for fumonisin B1+B2+B3). Overall mycotoxin levels in fish feeds reflected the feed ingredient composition and the level of contaminant in each feed ingredient. In all cases the studied ingredients and feeds showed levels of mycotoxins below maximum residue limits established by the Commission Recommendation 2006/576/EC. Following these guidelines no mycotoxin carry-over was found from feeds to edible fillets of salmonids and a typically marine fish, such as gilthead sea bream. As far we know, this is the first report of mycotoxin surveillance in farmed fish species. © 2015 Elsevier Ltd.This work has been (partly) funded under the EU Seventh Framework Programme by ARRAINA Project 288925: Advanced Research Initiatives for Nutrition and Aquaculture. The views expressed in this work are the sole responsibility of the authors and do not necessarily reflect the views of the European Commission. The authors also acknowledge the financial support (partly) of the project SAFE-PAP, Research Council Research and Development Project (227387) National Institute of Nutrition and Seafood Research (NIFES, Norway). The authors acknowledge the financial support of Generalitat Valenciana, as research group of excellence (PROMETEO II/2014/023, PROMETEO II/2014/085, and Collaborative Research on Environment and Food-Safety, ISIC/2012/016).Peer Reviewe

Behavior of Clayey Soil Existing in the Portoviejo Canton and Its Neutralization Characteristics

An investigation has been carried out on soil characterization and behavior in the canton of Portoviejo province of Manabí, in the Eloy Alfaro street sector of the Andrés de Vera Parish; where pits or open-air surveys were carried out and experimental laboratory tests of soils. It was demonstrated that soils have expansive properties of different characteristics, from medium to high degree of expansively according to the results of Laboratory of Soil Mechanics, where samples were tested analyzing the behavior according to the soil type. In this context, the results obtained by incorporating lime into the mixture are presented in 3 and 6%, thus obtaining a reduction by contraction to the volumetric change of the soil between 8 and 13%, allowing to improve its physical and mechanical properties; as well as its increase to bearing capacity by the California Bearing Ratio (CBR) test method from 9 to 16%, thus improving soil plasticity. With the results obtained, a description of the soil could be elaborated to determine the variations and changes according to the lime content, which was added to the soil, which allowed to reduce the deformations and damages caused to the superficial and structural pavement caused by the clays expansive, because in contact with the water the soil expands and at the same time when it drains the water contracts, proving that stabilizing the expansive clays with hydrated lime would improve the conditions of the pavement and its useful life

The abundances of polyacetylenes towards CRL618

We present a mid-infrared high spectral resolution spectrum of CRL618 in the frequency ranges 778-784 and 1227-1249 cm^-1 (8.01-8.15 and 12.75-12.85 um) taken with the Texas Echelon-cross-Echelle Spectrograph (TEXES) and the Infrared Telescope Facility (IRTF). We have identified more than 170 ro-vibrational lines arising from C2H2, HCN, C4H2, and C6H2. We have found no unmistakable trace of C8H2. The line profiles display a complex structure suggesting the presence of polyacetylenes in several components of the circumstellar envelope (CSE). We derive total column densities of 2.5 10^17, 3.1 10^17, 2.1 10^17, 9.3 10^16 cm^-2, and < 5 10^16 cm^-2 for HCN, C2H2, C4H2, C6H2, and C8H2, respectively. The observations indicate that both the rotational and vibrational temperatures in the innermost CSE depend on the molecule, varying from 100 to 350 K for the rotational temperatures and 100 to 500 K for the vibrational temperatures. Our results support a chemistry in the innermost CSE based on radical-neutral reactions triggered by the intense UV radiation field.Comment: 9 pages, 4 figures, 1 table; accepted for publication in The Astrophysical Journa