Biomonitoring of freshwater ecosystems: research and citizen participation in the Upper Valley of Río Negro and Neuquén (Patagonia, Argentina)

Fil: Macchi, Pablo. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro, ArgentinaFil: Maestroni, Britt. Division of Nuclear Techniques in Food and Agriculture. Department of Nuclear Sciences and Applications. Austria.Increases in population, along with related economic activities, have increased pressure on freshwater ecosystems in the Upper Valley region (Río Negro and Neuquén, Patagonia) in Argentina. Pesticides, fertilizers, hydrocarbons, plastics, and other pollutants drain into freshwater streams, rivers, wetlands, and ultimately the ocean, causing changes in the water quality, the biota, and ultimately affecting all ecological processes. To make sound decisions for the management of Argentinian fresh water, including planning and active regulation, it is essential to study and understand the relative risks of anthropogenic activities on the aquatic ecosystems. It is necessary to identify the sources and causes of the degradation of natural water habitats, assess their current state and analyze long-term trends in the health of the ecosystem so that Argentinian water bodies are sustainable and continue to provide fresh drinking water for local populations and irrigation water to sustain intensive agricultural production.

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Desarrollo de herramientas analíticas para garantizar la inocuidad alimentaria

Este trabajo de tesis representa una contribución para mejorar la inocuidad alimentaria y la sostenibilidad medioambiental, especialmente dirigida a cultivos menores, para los que se conocen y realizan muy pocos ensayos analíticos y para los que existe, en general, escasa información sobre los aspectos de inocuidad alimentaria. El objetivo a largo plazo incluye la posibilidad de contribuir al establecimiento o mejora de los marcos regulatorios actuales (es decir, bajo esquemas regulatorios como el CODEX Alimentarius), al tiempo que se prevé la disponibilidad de métodos analíticos validados junto con datos de referencia de residuos /contaminantes. El objetivo principal de este trabajo fue contribuir aún más al establecimiento y validación de herramientas analíticas que, combinadas de manera adecuada con los procesos de control de alimentos, para garantizar la inocuidad alimentaria para los consumidores de todo el mundo. Los sistemas de control de alimentos son marcos conceptuales dentro de los cuales las pruebas analíticas y los procesos de control interactúan entre sí para identificar, medir y gestionar los desafíos de la inocuidad de los alimentos, manteniendo al mismo tiempo un nivel adecuado de protección para los consumidores y los mercados comerciales. Esta tesis contribuyó a realzar el importante papel que representa el laboratorio analítico en la cadena de la granja a la mesa y destaca aún más la necesidad de interacción entre el lado analítico y los aspectos de monitoreo / regulación, en un proceso en tándem, donde ambos dependen fuertemente entre sí, y necesitan ser flexibles para adaptarse a condiciones de inocuidad alimentaria en constante cambio. El trabajo de tesis se dividió en tres bloques principales, cada uno de los cuales analizó diferentes aspectos para cultivos menores y otros cultivos. Los tres grandes capítulos desarrollados fueron: a saber el desarrollo y la validación de métodos analíticos, la calidad de los resultados analíticos y los vínculos entre las pruebas analíticas y los procesos de seguimiento / reglamentación

Validation of a Rapid Multiresidue Method for the Determination of Pesticide Residues in Vine Leaves. Comparison of the Results According to the Different Conservation Methods

International audienceThe QuEChERS method was applied to the determination of pesticide residues in vine (Vitis vinifera) leaves by LC-MSMS. The method was validated in-house for 33 pesticides representing 17 different chemical groups, that are most commonly used in grape production. Recoveries for the pesticides tested ranged from 75 to 104%, and repeatability and reproducibility relative standard deviations (RSDr% and RSDRw%) were less than 20%. The method was applied to the analysis of pesticide residues in 17 market brands of vine leaves processed according to three different preservation methods and sampled from the Lebanese market. Dried vine leaves were more contaminated with pesticide residues than those preserved in brine or stuffed vine leaves. The systemic fungicides were the most frequently detected among all the phytosanitary compounds usually applied to grape production. Brine-preserved and stuffed vine leaves contained lower concentrations of the residues but still contained a cocktail of different pesticides

The Effects of Formulation on Imidacloprid Dissipation in Grapes and Vine Leaves and on Required Pre-Harvest Intervals under Lebanese Climatic Conditions

In this study, imidacloprid, a systemic insecticide, currently having a specified European Commission MRL value for vine leaves (2 mg kg&minus;1), was applied on a Lebanese vineyard under different commercial formulations: as a soluble liquid (SL) and water dispersible granules (WDG). In Lebanon, many commercial formulations of imidacloprid are subject to the same critical good agricultural practice (cGAP). It was, therefore, important to verify the variability in dissipation patterns according to matrix nature and formulation type. Random samplings of grapes and vine leaves were performed starting at 2 days until 18 days after treatment. Residue extractions were performed according to the QuEChERS method and the analytical determination using liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). The SL formulation yielded significantly higher initial deposit than the WDG formulation on grapes and vine leaves. The formulation type did not significantly affect the dissipation rates; the estimated half-lives in grapes and vine leaves were 0.5 days for all imidacloprid formulations. No pre-harvest intervals were necessary on grapes. PHIs of 3.7 days for the SL formulation and 2.8 days for the WDG formulation were estimated on vine leaves. The results showed that the type of formulation and the morphological and physiological characteristics of the matrix had an effect on the initial deposits, and thus residue levels, but not on the dissipation patterns

Analysis of DDT Residues in Soil by ELISA: An International Interlaboratory Study

An international interlaboratory study was conducted to determine the performance of a group of laboratories from developing and developed countries. The study used a commercial microwell ELISA on unknown samples spiked with different levels of DDT. The study design was based on Youden pairs and balanced replicates. Two soils, differing in particle size distributions, organic matter content, and cation-exchange capacities and thought to be DDT-free, were spiked at 5 DDT levels between 0.025 and 2 mg/kg. Nineteen laboratories in 17 countries took part in the collaborative trial; of these, the majority were modestly equipped laboratories in developing countries. Samples were analyzed without filtration or cleanup and using standards of pure DDT in methanol. Data were analyzed for repeatability and reproducibility, and average recoveries at the spike levels were calculated. Mean real recoveries for both soils were similar (103% for soil A and 100% for soil B), with values between 0.1 and 2 mg/kg DDT. Precision estimates were best in the linear working range of the assay (0.1-0.5 mg/kg DDT), with reproducibility relative standard deviations (RSD R ) typically averaging about 38 and 46% near the upper and lower detection limits, respectively. Corresponding repeatability relative standard deviation (RSD r ) values were 20-36% and 36-57%. Thus, even though much of the trial was performed under developing country conditions, performance statistics were similar to other reported results obtained with ELISAs on small molecules of agricultural importance, such as mycotoxins and pesticide and antibiotic residues

Development of a liquid chromatography-tandem mass spectrometric method for the simultaneous determination of tropane alkaloids and glycoalkaloids in crops

International audienceA new, rapid and sensitive multiresidue method is reported for the simultaneous determination of tropane alkaloids (tropine, atropine, scopolamine, homatropine, anisodamine) and glycoalkaloids (α-solanine, α-chaconine) in grains and seeds (wheat, rye, maize, soybean, linseed). Dispersive solid phase extraction (DSPE) was performed with 0.5% formic acid in acetonitrile/water and a mixture of magnesium sulphate, sodium chloride and sodium citrate. For a fast and effective clean-up procedure for oily matrices such as soybean and linseed, matrix solid phase dispersion (MSPD) C18 material was used to remove co-extracted non-polar components. No clean-up was necessary for less oily matrices following extraction. The analytes were separated by isocratic HPLC on a Chirobiotic V column and detected using a triple quadrupole mass spectrometer with electrospray ionization (ESI). All analytes were monitored in the positive ion mode. The method performance is presented in terms of linearity in the range 5-80 ng/g (r2=0.998), specifity, selectivity, accuracy (recoveries from 61-111%), precision (CV < 5%) and ruggedness. The limits of quantitation (LOQ) were in the range 2.2-4.9 ng/g

Ruggedness testing of an analytical method for pesticide residues in potato

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. The best demonstration of the ruggedness of a method is monitoring its performance on an ongoing basis as part of the analytical quality control applied in the laboratory. However, an initial demonstration of the ruggedness is often performed as one aspect of the method validation, to give confidence that the method should perform well under normal variations in conditions in routine application. This initial ruggedness testing is typically performed using either multiple replicate analyses or application of design of experiments (DoEs) which minimizes the number of analyses, time and effort required to detect influences on the measurement results. Two DoEs were applied for ruggedness testing for a modified QuEChERS multiresidue method for the detection of pesticide residues in potato by GC–MS/MS. Seven experimental factors were studied using an eight-run Plackett–Burman design replicated three times and an augmented definitive screening design with 34 runs. The relative effectiveness of the two approaches is discussed, in terms of their statistical significance, their cost-effectiveness and the richness of information they provide on the effects of the parameters investigated and the actual robustness of the method being tested.status: publishe