Search results for "Underwater"

Development and validation of a pressurized liquid extraction liquid chromatography–tandem mass spectrometry method for perfluorinated compounds dete…

2009

Abstract This paper describes the development and validation of an analytical methodology to determine eight perfluorinated compounds (PFCs) in edible fish using pressurized liquid extraction (PLE) with water and solid-phase extraction (SPE) with an ion-exchanger as extraction and pre-concentration procedures, followed by liquid chromatography–quadrupole-linear ion trap mass spectrometry (LC–QqLIT–MS). The rapidity and effectiveness of the proposed extraction procedure were compared with those most commonly used to isolate PFCs from fish (ion-pairing and alkaline digestion). The average recoveries of the different fish samples, spiked with the eight PFCs at three levels (the LOQ, 10 and 100…

Yeast β-glucans and microalgal extracts modulate the immune response and gut microbiome in Senegalese sole (Solea senegalensis)

2019

One bottleneck to sustainability of fish aquaculture is the control of infectious diseases. Current trends include the preventive application of immunostimulants and prebiotics such as polysaccharides. The present study investigated how yeast β-glucan (Y), microalgal polysaccharide-enriched extracts (MAe) and whole Phaeodactylum tricornutum cells (MA) modulated the gut microbiome and stimulated the immune system in Senegalese sole (Solea senegalensis) when administered by oral intubation. Blood, intestine and spleen samples were taken at 3 h, 24 h, 48 h and 7 days after treatment. The short-term response (within 48 h after treatment) consisted of up-regulation of il1b and irf7 expression in…

How diffusivity, thermocline and incident light intensity modulate the dynamics of Deep Chlorophyll Maximum in Tyrrhenian Sea

2015

During the last few years theoretical works have shed new light and proposed new hypotheses on the mechanisms which regulate the spatio-temporal behaviour of phytoplankton communities in marine pelagic ecosystems. Despite this, relevant physical and biological issues, such as effects of the time- dependent mixing in the upper layer, competition between groups, and dynamics of non-stationary deep chlorophyll maxima, are still open questions. In this work, we analyze the spatio-temporal behaviour of five phytoplankton populations in a real marine ecosystem by using a one-dimensional reaction-diffusion-taxis model. The study is performed, taking into account the seasonal variations of environm…

Organic matter quantity and quality, metals availability and foraminiferal assemblages as environmental proxy applied to the Bizerte Lagoon (Tunisia)

2016

International audience; This study analyzes the benthic trophic state of Bizerte Lagoon (Tunisia) based on the total organic matter and the bioavailability of biopolymeric carbon including proteins (PTN), carbohydrates (CHO), lipids (LIP), chlorophyll a, as well as bacteria counts. The overall simultaneously extracted metals (SEM), and acid volatile sulfides (AVS) as well as the SEM/AVS ratio indicative of the toxicity of the sediments also were analyzed aiming to study their impact in the dimension, composition and structure of both dead and living benthic foraminiferal assemblages.In the studied sites TOC content is relatively high and the PTN/CHO values indicate that they can be consider…

A practical approach to improve the statistical performance of surface water monitoring networks

2019

The representativeness of aquatic ecosystem monitoring and the precision of the assessment results are of high importance when implementing the EU’s Water Framework Directive that aims to secure a good status of waterbodies in Europe. However, adapting monitoring designs to answer the objectives and allocating the sampling resources effectively are seldom practiced. Here, we present a practical solution how the sampling effort could be re-allocated without decreasing the precision and confidence of status class assignment. For demonstrating this, we used a large data set of 272 intensively monitored Finnish lake, coastal, and river waterbodies utilizing an existing framework for quantifying…

Mapping and assessing coastal resilience in the Caribbean region

2015

Assessing the vulnerability and resilience to coastal hazards is a critical worldwide issue, especially for hurricane-prone coastal regions such as the Caribbean. However, the development of a useful metric for vulnerability and resilience assessment has a lot of challenges. Cartography and GIS analysis can contribute effectively to the solution of the issue by integrating natural and human data layers for assessment, mapping, and visualization. This paper uses the new Resilience Inference Measurement (RIM) model to assess the resilience of 25 countries in the Caribbean region to hurricanes. The RIM indices of the countries were computed using three variables representing three dimensions: …

On the determination of coherent solar climates over a tropical island with a complex topography

2020

Abstract Many tropical islands aim at developing a greener self-sufficient energy production systems based on renewable energy, notably solar-generated electricity. This work explores the mean diurnal and annual solar cycles over La Reunion island (southwest Indian Ocean: 21°S, 55.5°E), and their spatial behavior, using the Solar surfAce RAdiation Heliosat – East (SARAH-E) satellite-derived data at high spatial ( 0.05 ° × 0.05 ° ) and time (hourly) resolutions over period 1999–2016. Comparisons of the SARAH-E data with ground-based measurements over the period 2011–2015 show differences of ~ 15 % for diurnal-seasonal variations. The solar resource over the island displays strong spatial var…

A geometry-based channel model for shallow underwater acoustic channels under rough surface and bottom scattering conditions

2014

Evaluation of the Measuring Active Drag system usability: An important step for its integration into training sessions

2010

This paper is the first stage of an iterative process aiming at the (re)design of a training device for swimming. The purpose of this study was to evaluate the usability of the Measuring Active Drag (MAD) system, a technical device for biomechanical evaluation and performance analysis. To do so, this study examines real activity of elite swimmers using this system. It was conducted within an activity-centred approach: the course-of-action technological research programme. Three international male swimmers volunteered to participate in the study. Two types of data were collected: (a) video recordings, and (b) verbalisations during post-protocol interviews. The data were processed in two step…

Additional file 1: of Effects of geolocators on hatching success, return rates, breeding movements, and change in body mass in 16 species of Arctic-b…

2016

Supplementary methods, Tables and Figures provides further details on field methods, data, and results that support the main text. (PDF 637 kb)