Volcanic soil gas He/CO ratio: a useful geochemical tool for real-time eruption forecasting.

At many dormant volcanoes, magmatic gases are not channeled through preferential degassing routes as fumaroles and only percolate through the flanks of the volcano in a diffuse way. This type of volcanic gas emission provides valuable information, even though the soil matrix contains an important atmospheric component. This study aimed to demonstrate that chemical ratios such as He/CO in soil gases provide excellent information on the evolution of volcanic unrest episodes and help forecast the volcanic eruption onset.

Diffuse CO degassing precursors of the January 2020 eruption of Taal volcano, Philippines.

On January 12, 2020, Taal volcano in Philippines erupted, 43 years after its previous eruption in 1977. This eruption was preceded by diffuse CO degassing precursory signals. Significant temporal variations in diffuse CO emission from Taal Main Crater Lake (TMLC) were observed across the ~ 12 years reaching high CO degassing rates in 2011 and 2017, with values typical of plume degassing volcanoes.

Dietary changes across time: Studying the indigenous period of La Gomera using δ C and δ N stable isotope analysis and radiocarbon dating.

Objectives: This article presents new radiocarbon and isotopic data to provide further information about the diet of the indigenous population of La Gomera and its possible changes across time.

Materials And Methods: δ C and δ N of 53 human and 19 faunal samples from different sites on the island have been obtained and analyzed. Of these, 52 have been radiocarbon dated to provide insight on chronological changes.

Volatile organic compounds (VOCs) in solid waste landfill cover soil: Chemical and isotopic composition vs. degradation processes.

Landfills for solid waste disposal release to the atmosphere a large variety of volatile organic compounds (VOCs). Bacterial activity in landfill cover soils can play an important role in mitigating VOC emission. In order to evaluate the effects of degradation processes and characterize VOCs composition in landfill cover soil, gases from 60 sites and along 7 vertical profiles within the cover soil were collected for chemical and isotopic analysis at two undifferentiated urban solid waste disposal sites in Spain: (i) Pinto (Madrid) and (ii) Zurita (Fuerteventura, Canary Islands).

Three-Dimensional Evaluation of Maxillary Sinus Septa for Implant Placement.

Background: The aim of our study was to investigate, in 3 dimensions, the maxillary sinus septa as an alternative site for dental implant placement to avoid sinus lift procedures.

Material And Methods: We selected 100 dentate and 100 edentate patients with the presence of a maxillary sinus septum by reviewing a larger cone beam computer tomography (CBCT) database from the Department of Oral and Maxillofacial Surgery at Cliniques Universitaires Saint Luc in Bruxelles, Belgium. Three-dimensional reconstructions of 200 maxillary sinus septa were performed using Maxilim software.

Maxillary sinus anatomic and pathologic CT findings in edentulous patients scheduled for sinus augmentation.

Objectives: An aberrant sinus anatomy or pathology can influence the sinus lift technique if it is encountered during surgical exposure. The purpose of the present study was to determine the prevalence of sinus disease and variations of normal anatomy among edentulous patients prior to sinus augmentation.

Material And Methods: 120 patients attending a private surgical practice (53 women and 67 men, with a mean age of 62.

High-performance liquid chromatographic analysis of carbofuran residues in tomatoes grown in hydroponics.

Tomato plants grown in hydroponics were irrigated three times on alternate days with nutrient solutions fortified with carbofuran at levels of 36, 111 and 222 mg 1-1, and carbofuran residues were analysed in tomato fruits. Residues were found to be below the maximum residue level set up by Codex Alimentarius Mundi (0.1 mg kg-1) 6, 11 and 18 days after the third irrigation with nutrient solutions fortified with carbofuran.

Determination of carbofuran by GLC/NPD and HPLC in tomato fruits.

Two analytical methods, using GLC/NPD and HPLC to analyse carbofuran residues in tomatoes, are described. Both methods have shown a high recovery rate, up to 90%, and their detection limits are below the maximum residue limit set by Codex Alimentarius Mundi for carbofuran in tomatoes. Therefore, both methods may be of use in routine analysis of this pesticide in those fruits.