A5069554526- Clay minerals and soil interactions
- Avian ecology and behavior
- Soil and Unsaturated Flow
- Iron oxide chemistry and applications
- Ecology and Vegetation Dynamics Studies
- Fire effects on ecosystems
- Species Distribution and Climate Change
- Geological and Geophysical Studies Worldwide
- Agriculture and Rural Development Research
- Soil Carbon and Nitrogen Dynamics
- Wildlife Ecology and Conservation
- Geological and Geochemical Analysis
- Heavy metals in environment
- Therapeutic Uses of Natural Elements
- Fish Ecology and Management Studies
- Geology and Paleoclimatology Research
- Forest Ecology and Biodiversity Studies
- Marine and fisheries research
- Geological formations and processes
- Soil erosion and sediment transport
- Animal Ecology and Behavior Studies
- Isotope Analysis in Ecology
- French Urban and Social Studies
- Lichen and fungal ecology
- Marine and coastal plant biology
Environment and Climate Change Canada
2002-2018
Hawaii Pacific University
2014
University of Hawaiʻi at Mānoa
2014
University of Hawaii System
2014
LIttoral ENvironnement et Sociétés
2012
United States Geological Survey
2008-2011
Université du Québec à Rimouski
2010
La Rochelle Université
2001-2008
Pacific Island Ecosystems Research Center
2008
University of Hawaii at Hilo
2008
Summary Copper sulphate (Bordeaux mixture) has been used as a fungicide against mildew in vineyards for more than hundred years. This treatment resulted significant Cu accumulation soils (from 100 to 1500 mg kg −1 ). It is desirable determine the distribution of these predict if this element potentially toxic. Several speciation methods have compared: sequential and single–step extractions, analytical transmission electron microscopy (ATEM, ASEM) physical fractionation study profile vineyard...
SUMMARY The ability of the roots rape ( Brassica napus ) to promote transformation and dissolution a phlogopite mica was studied in rhizosphere. Rape cropped for 1 32 d on 2–105 μm as sole source both K Mg. chemical balance Mg revealed that able induce significant release interlayer‐K after 4 d, even octahedral‐Mg 8 cropping. After root‐induced amounted 80 21 g kg −1 total‐K ‐Mg, respectively. weathering products sampled close proximity were analysed by X‐ray diffractometry (XRD), energy...
Following heavy precipitation, we observed an intense algal bloom in the St. Lawrence Estuary (SLE) that coincided with unusually high mortality of several species marine fish, birds and mammals, including designated at risk. The was identified as Alexandrium tamarense determined to contain a potent mixture paralytic shellfish toxins (PST). Significant levels PST were found liver and/or gastrointestinal contents carcasses tested well live planktivorous molluscs plankton samples collected...
The natural river water certified reference material SLRS‐4 (NRC‐CNRC, National Research Council‐Conseil de Recherches Canada) has been routinely analysed for major and trace elements by six French laboratories. Most measurements were made using inductively coupled plasma‐mass spectrometry. For silicon thirty one (rare earth elements, Ag, B, Br, Cs, Ga, Ge, Li, P, Pd, Rb, Se, Th, Ti, Tl, W, Y Zr), no values are assigned NRC‐CNRC. We propose some compilation related uncertainties according to...
A study was carried out in northeastern Venezuela to determine whether or not shorebirds feed at night tropical environments. Results show that some Neotropical residents and Nearctic winter migrants during darkness. During daylight, Black‐winged Stilts Himantopus himantopus, mexicanus group, were predominantly visual foragers (75% attempts pecking), performing a tactile type of feeding technique (immersion the whole head portion neck while searching for food through soft mud) on other...
On a small bay of the Chacopata lagoon complex in northeastern Venezuela, we analyzed temporal feeding activity patterns shorebirds and other water birds, determined factors or conditions related to these patterns. During daytime nighttime observations, measured abundance each species as well environmental (time, wind velocity, cloudiness, tide level, presence moonlight bioluminescence). A night vision module (light intensifier) was used during observations. Samples × matrices were...
Abstract Aluminous hydroxy 2/1 clay minerals (‘intergrades’) can form in two ways: Al either come externally from the solution, or internally mineral itself (octahedral tetrahedral layers). This study is more concerned with latter which seems main source acid soils. The most common organic acids present under natural conditions were used on trioctahedral micas (phlogopite and biotite), their chemical mineralogical weathering effects determined. Different kinds of evolution are possible:...
Abstract Total concentrations for Hg, Pb, Cd, Se, As, Sn, U, Zn, Ni, Cu, Cr, Sb, Sr, Pd and Ag were determined in surface sediments of the mangroves, lagoons Southern Bay from Florianópolis Island Brazil, by using a ICP-MS technique statistic methods. The goal was to estimate actual level contamination metals Island. results show, that many sites, higher than mean elemental composition on earth found U Ag. analysis shows follows more preferentially variation fine grain fraction organic...
Abstract Habitat loss and degradation induced by human development are among the major threats to biodiversity worldwide. In this study, we tested our ability predict response of bird communities (128 species) land‐use changes in southern Quebec (~483,100 km 2 ) over last 30 yr (between 1984–1989 2010–2014) using species distribution models (299,302 occurrences 30,408 locations) from a hindcasting perspective. Results were grouped functional guilds infer potential impacts on ecosystem...
We compared time-budgets and return rates of breeding female Barrow’s Goldeneyes (Bucephala islandica) fitted, or not, with transmitters attached backpack harnesses in 2001-2004 southern Québec. the mean proportion time devoted to feeding, locomotion, alert, resting, preening, maintenance (i.e., resting plus preening) by females observed ≥200 min. Females backpacks (N = 5) spent significantly less feeding (x ± SE: 25 5% versus 43 3%) more activities (51 6% 31 4%) than without 6). Mean other...
Abstract : Smectite genesis in two granitic saprolites was studied, using qualitative and quantitative mineralogical methods high resolution transmission electron microscopy (HRTEM). The primary minerals (plagioclase mica) give rise to the formation of different kinds smectites according weathering conditions (pH drainage). Under a relatively basic, drained environment, neoformed montmorillonite with spheroidal organization exists fillings plagioclase cores. In same biotites are transformed...
Abstract The mineralogy, crystallochemistry and microfabric of clay minerals from acidic soils were studied using transmission electron microscopy (TEM) analytical (AEM). Soil profiles, developed on saprolites, sampled in the main crystalline massifs France represent different pedological environments. study focused microsystem mica weathering, which appeared to be source secondary minerals, involves microdivision, transformation dissolution. Microdivision begins with splitting large...
Abstract The nature, crystallochemistry, organization and surface properties of soil clays derived from the most representative sedimentary formations France are described, using qualitative quantitative mineralogical methods high resolution transmission microscopy (HRTEM). main results show that differ significantly reference clays. Even when 2:1 phyllosilicates dominant, always contain multimineral phases. smectitic component is dioctahedral beidellite type. Soil clay specific: all...
Abstract The rocks of the palygorskite deposit at Bercimuel (Segovia, Spain) have been studied by transmission electron microscopy and microanalysis. These correspond to zone convergence two alluvial fan systems that filled small basin River Riaza would originally composed illite quartz silts. Among accumulations it is possible observe surrounded particles micromicas undergone dissolution opening thereby giving rise disordered illite-smectite mixed-layer clays. This process continued up...
We performed an in situ experiment with the aim of getting evidence for contemporary podzolization a soil sequence near Manaus, Amazonia, Brazil. Samples test-mineral [high cation exchange capacity (CEC) vermiculite], as well small bags or chelating resins, were inserted soils (Oxisols, Ulti-sols, and Spodosols). based study on following principles: when placed acidic complexing system (podzolization), vermiculite undergoes desaluminization process its CEC saturates Mg by relative...
Oxidative stress could be an important phenomenon leading to melanocyte death in vitiligo. The accumulation of hydrogen peroxide (H2O2) and low catalase levels have recently been demonstrated the epidermis vitiligo patients. Few abnormalities antioxidants found blood patients with vitiligo, except for elevation selenium. No studies on oxidative performed so far skin phototype VI (Fitzpatrick classification).To study antioxidant status black active generalized vitiligo.Randox total status,...