Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location.
The Frederick Street steps (known locally as the Saint Andrew's, Hill Crest, or Blackbeard's Steps) were carved from stone in 1793. The steps were the original home for the cenotaph before its relocation to the Garden of Remembrance. In the background is the Trinity Methodist Church’s roof and Saint Andrew’s Presbyterian Church’s bell tower. Slide labeled Bryant Nassau Mar .'46, In front of Government House where the Windsor's lived.
Bahamas -- North America -- Nassau, New Providence Island

Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu
CFM1972_01a
Sheet 16:7
http://ufdc.ufl.edu/AA00029448/00001

Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location.
A man and a woman walk near the coast of Little Abaco, Bahamas. The woman, pictured, traveled with William Junior Bryant during his trip to the Bahamas in April 1965. In the distance, there are two people in a row boat. Slide labeled Indian Hill Little Harbor April '65.
Bahamas -- North America -- Little Abaco

Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu
CFM1972_01a
Sheet 11:12
http://ufdc.ufl.edu/AA00028959/00001

Résumé : (Funding) Support for the development of the technical infrastructure and partner training provided by the United States Department of Education TICFIA program.
Luchetti's Hill (Charlotte Amalia, V.I.) -- Charlotte Amalia (V.I.) -- Saint Thomas (V.I.) -- Bluebeard's Castle (Charlotte Amalie, V.I.)
Caribbean

Résumé : La thèse est consacrée à la recherche des catastrophes marines (tsunamis, ondes de tempête) dans les Antilles françaises, en utilisant des modèles analytiques et numériques de mécanique des fluides. L'accent est mis sur le développement de modèles de mouvement de glissements de terrain et des vagues causées par ces glissements. Le modèle le plus simple du glissement de terrain «solide block» est utilisé pour évaluer les caractéristiques des flux pyroclastiques du volcan Soufrière-Hills (Montserrat). Un modèle plus complexe de modélisation de glissement de terrain (modèle de Savage-Hutter) a été étudié analytiquement, donnant ainsi une nouvelle famille de solutions exactes décrivant le mouvement de l'écoulement par gravité non linéaire dans une vallée ou dans un canyon sous-marin. Le modèle comprend des ondes simples (Riemann waves),le cas d'un barrage qui cède (dam-break problem), des solutions auto-similaires dans la M-fonne et « chapeaux paraboliques ». Grâce à la théorie linéaire de l'eau peu profonde nous avons étudié le processus de génération de tsunamis par des glissements de terrain de volume variable, se déplaçant à une vitesse variable dans un bassin de profondeur variable. Dans le cas d'un fond marin particulier (cas sans "réflexion"), les phénomènes de résonnance ont été étudiés dans un bassin à profondeur variable. Nous avons utilisé des méthodes numériques pour la résolution non-linéaire des équations des eaux peu profondes afin d'analyser des catastrophes marines réelles (les ondes de tempête causées par le cyclone Lili en 2002, le tsunami volcanique de 2003 à Montserrat) et probables (un tsunami prés des côtes de la Martinique). Des données sur les catastrophes
The dissertation is devoted to research in the field of marine natural hazards (tsunamis, storm surges) in the French West Indies, using analytical and numerical models of fluid mechanics. Emphasis is placed on the development of models of landslide motion and generated tsunami waves. The simple "solid block" model is used to evaluate the characteristics of pyroclastic flow Soufriere Hills volcano (Montserrat). The "fluid model" of a landslide (so called Savage-Hutter model) is studied analytically; within this model a new family of exact solutions that describe the motion of nonlinear gravity flow in a valley or underwater canyon is found: nonlinear Riemann wave, dan break problem, self-similar solutions (M - wave and parabolic cap). In the framework of the linear shallow water theory the process of generation of tsunami waves by landslides of variable volume moving with variable velocity above the basin of variable depth is studied. For the specific bottom profile ("reflectionless" one) the resonant phenomena is investigated in the basin of variable depth. Numerical methods are used to analyze marine hazards: historical (storm surges, caused by Cyclone LILI in 2002; volcanic tsunami 2003 on Montserrat) and possible events (possible tsunami of the coast of Martinique). Various data on marine natural disasters are obtained during field surveys (volcanic tsunami in 2003, stonn surges caused by Hurricane Dean in 2007). Designed catalogs of tsunamis and storm surges are created based on results of numerical modeling and field studies; some statistical analysis is perfomed

http://www.theses.fr/2011AGUY0435/document

Éditeur(s) : Amer Geophysical Union
Résumé : The oblique convergence between North American and Caribbean plates is accommodated in a bookshelf faulting manner by active, oblique-normal faults in the northern part of the Lesser Antilles arc. In the last 20 years, two M > 6 earthquakes occurred along a large, arc parallel, en echelon fault system, the 16 March 1985 in Redonda and 21 November 2004 in Les Saintes. A better understanding of active faulting in this region permit us to review the location and magnitude of historical earthquakes by using a regional seismic attenuation law. Several others moderate earthquakes may have occurred along the en echelon fault system implying a strong seismic hazard along the arc. These faults control the effusion of volcanic products and some earthquakes seem to be correlated in time with volcanic unrest. Shallow earthquakes on intraplate faults induced normal stress and pressure changes around neighboring volcano and may have triggered volcanic activity. The Redonda earthquake could have initiated the 1995 eruption of Montserrat's Soufriere Hills by compressing its plumbing system. Conversely, pressure changes under the volcano increased Coulomb stress changes and brought some faults closer to failure, promoting seismicity. We also discuss the magnitude of the largest 11 January 1839 and 8 February 1843 megathrust interplate earthquakes. We calculate that they have increased the stress on some overriding intraplate faults and the extensional strain beneath several volcanoes. This may explain an increase of volcanic and seismic activity in the second half of the 19th century culminating with the devastating, 1902 Mount Pelee eruption.
Journal Of Geophysical Research-solid Earth (0148-0227) (Amer Geophysical Union), 2011-10 , Vol. 116 , N. B10308 , P. 1-26

Droits : Copyright 2011 by the American Geophysical Union
http://archimer.ifremer.fr/doc/00200/31097/29515.pdf
DOI:10.1029/2011JB008443
http://archimer.ifremer.fr/doc/00200/31097/

Éditeur(s) : HAL CCSD
Résumé : Master
La biodiversité peut être mesurée de nombreuses façons. La dualité entropie-diversité fournit un cadre clair et rigoureux pour le faire. L’entropie est la surprise moyenne fournie par les individus d’une communauté. Le choix de la fonction d’information qui mesure cette surprise à partir des probabilités d’occurence des espèces (ou d’autres catégories) permet de définir les mesures de diversités neutres, fonctionnelles ou phylogénétique présentées ici. L’entropie est transformée en diversité au sens strict par une fonction croissante (l’exponentielle déformée), ce qui simplifie son interprétation en tant que nombre équivalent d’espèces.L’entropie phylogénétique généralise les indices de diversité classique, intègre si nécessaire la distance entre espèces, peut être écomposée et corrigée des biais d’estimation. Sa transformation en diversité au sens strict permet d’interpréter les valeurs sous une forme unique : un nombre équivalent d’espèces et un nombre équivalent de communautés. La diversité de Leinster et Cobbold généralise à son tour la diversité phylogénétique et permet d’autres définitions de la distance entre espèces. Le paramétrage des mesures (l’ordre de la diversité) permet de donner plus ou moins d’importance aux espèces rares et de tracer des profils de diversité.La construction de ce cadre méthodologique est présentée en détail ainsi que plusieurs approches différentes, qui constituent l'état de l'art de la mesure de la biodiversité.
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813
Kourou, France

cel-01205813
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813v4/document
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813/file/Mesures_de_la_Biodiversite.pdf

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km(2)) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along the stream. Samples were taken in-between and during 14 storm events at the beginning and middle of the 2005 and 2006 rainy seasons. Dissolved and particulate HgT concentrations in the stream slightly increased downstream, while dissolved and particulate MMHg concentrations were low at the pristine sub-watershed outlet (median = 0.006 ng L-1 and 1.84 ng g(-1), respectively) and sharply increased at the gold mined flat outlet (median = 0.056 ng L-1 and 6.80 ng g(-1), respectively). Oxisols, which are dominant in the pristine area act as a sink of HgT and MMHg from rain and throughfall inputs. Hydromorphic soils in the flat are strongly contaminated with Hg (including Hg droplets) and their structure has been disturbed by former gold-mining processes, leading to multiple stagnant water areas where biogeochemical conditions are favorable for methylation. In the former gold mined flat high dissolved MMHg concentrations (up to 0.8 ng L-1) were measured in puddles or suboxic soil pore waters, whereas high dissolved HgT concentrations were found in lower Eh conditions. Iron-reducing bacteria were suggested as the main methylators since highest concentrations for dissolved MMHg were associated with high dissolved ferrous iron concentrations. The connection between saturated areas and stagnant waters with the hydrographic network during rain events leads to the export of dissolved MMHg and HgT in stream waters, especially at the beginning of the rainy season. As both legal and illegal gold-mining continues to expand in French Guiana, an increase in dissolved and particulate MMHg emissions in the hydrographic network is expected. This will enhance MMHg bio-amplification and present a threat to local populations, whose diet relies mainly on fish.
Water Research (0043-1354) (Pergamon-elsevier Science Ltd), 2011-04 , Vol. 45 , N. 8 , P. 2659-2669

Droits : 2011 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/00035/14628/12134.pdf
DOI:10.1016/j.watres.2011.02.022
http://archimer.ifremer.fr/doc/00035/14628/

Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location.
Vinales Valley mogotes, picture was taken from a lookout above the valley floor. Mogotes are rounded, tower-like limestone hills.
Cuba -- Caribbean region -- Vinales Valley

Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu
CFM1972_01a
Sheet 25: 15
http://ufdc.ufl.edu/CA01200394/00001

Éditeur(s) : HAL CCSD Geological Society of London
Résumé : International audience
The interplay between tectonics and erosion has a predominant control on the evolution of the morphology of mountain belts. Here we investigate the modalities of deformation in Central Nepal on a c. 100 ka time scale in response to tectonic and external forcings, through the use of a finite-element thermomechanical model coupled with an integrative denudation formulation that accounts for fluvial incision and hillslope landsliding. We study the complex coupling existing between tectonics and erosion, with special emphasis on the influences of rock strength and rainfall distributions. Our results underline the key role played by lithologic variations in the elevation of both rivers and mean topography. We show that the location of the Main Frontal Thrust is mainly controlled by the low erodability of the unconsolidated sandstone in the Siwaliks Hills. As previously suspected (Burbank et al. 2003), our simulations demonstrate that the pattern of uplift in Nepal is mainly dependent on both erodability and fault geometry, rather than on rainfall distribution.
ISSN: 2041-4927

hal-01543331
https://hal-amu.archives-ouvertes.fr/hal-01543331
DOI : 10.1144/GSL.SP.2006.253.01.18

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The quasi-equilibrium approximation is acceptable when molecular interactions are fast enough compared to circuit dynamics, but is no longer allowed when cellular activities are governed by rare events. A typical example is the lactose operon (lac), one of the most famous paradigms of transcription regulation, for which several theories still coexist to describe its behaviors. The lac system is generally analyzed by using equilibrium constants, contradicting single-event hypotheses long suggested by Novick and Weiner (1957). Enzyme induction as an all-or-none phenomenon. Proc. Natl. Acad. Sci. USA 43, 553-566) and recently refined in the study of (Choi et al., 2008. A stochastic single-molecule event triggers phenotype switching of a bacterial cell. Science 322, 442-446). In the present report, a lac repressor (LacI)-mediated DNA immunoprecipitation experiment reveals that the natural LacI-lac DNA complex built in vivo is extremely tight and long-lived compared to the time scale of lac expression dynamics, which could functionally disconnect the abortive expression bursts and forbid using the standard modes of lac bistability. As alternatives, purely kinetic mechanisms are examined for their capacity to restrict induction through: (i) widely scattered derepression related to the arrival time variance of a predominantly backward asymmetric random walk and (ii) an induction threshold arising in a single window of derepression without recourse to nonlinear multimeric binding and Hill functions. Considering the complete disengagement of the lac repressor from the lac promoter as the probabilistic consequence of a transient stepwise mechanism, is sufficient to explain the sigmoidal lac responses as functions of time and of inducer concentration. This sigmoidal shape can be misleadingly interpreted as a phenomenon of equilibrium cooperativity classically used to explain bistability, but which has been reported to be weak in this system.
ISSN: 0022-5193

inserm-00818506
http://www.hal.inserm.fr/inserm-00818506
http://www.hal.inserm.fr/inserm-00818506/document
http://www.hal.inserm.fr/inserm-00818506/file/LacI-TeX.pdf
ARXIV : 1312.5566

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Dahomey belt in Togo and Benin is an important segment of the larger West Gondwana Orogen. Here, we review the geodynamic evolution of the Dahomey belt and discuss new U–Pb and Lu–Hf zircon data in light of similar data previously acquired on the geologically related Northern Borborema Province, in NE Brazil. Eighteen samples from different tectonic settings and regions within the belt were collected for zircon isotopic investigation. Passive margin deposits of the Atacora Structural Unit and lower units of the Volta Basin have detrital zircon signatures compatible with the flanking West Africa Craton. The arc-related magmatism resulted from the east-dipping subduction of the Goiás-Pharusian oceanic lithosphere and is represented by a variety of granitoids emplaced in the Benino-Nigerian Shield between 670 and 610 Ma. These granitoids were mainly sourced from crustal reservoirs with subordinate juvenile input. Detrital zircon ages from syn-orogenic deposits in Benino-Nigerian Shield suggest that arc development could have started as early as 780 Ma. The main period of melting in the internal part of the belt, the Benino-Nigerian Shield, is related to crustal thickening and occurs only ca. 30 m.y. after initiation of the continental collision, marked by the ca. 610 Ma ultra-high pressure (UHP) metamorphism recorded at Lato Hills. Foreland development represented by the upper units of the Volta basin developed soon after continental collision and persisted with the development of the west-verging thrust front synchronously with the main period of crustal melting due to collision at ca. 580 Ma. The subvertical Transbrasiliano Lineament in South America, that corresponds to the Kandi Lineament in Africa, provides a present-day fit between NW Africa and NE Brazil. Restoration of the movement of the Transbrasiliano-Kandi Lineament (strike-slip plate boundary) places the Dahomey belt and Borborema Province (NE Brazil) along the same section of the West Gondwana Orogen. This configuration would explain some of the misfits previously discussed in the literature and aligns the UHP eclogites in Togo and NE Brazil.
ISSN: 0301-9268

hal-01358584
https://hal.archives-ouvertes.fr/hal-01358584
DOI : 10.1016/j.precamres.2016.01.032

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Maguelone shore extends along the northern coast of the Gulf of Lions, west of the Rhone Delta and east of high-gradient coastal streams that have provided most of the clastic sediments to the Gulf of Lions margin since the early Miocene. This 10 km-wide area is constituted by a small coastal watershed (15 km long) in low-lying carbonate hills, a kilometre-wide marsh, a sandy beach barrier and a shoreface experiencing local low sedimentation rates. This onshore-offshore transition zone is a key area to understand the relationships between erosion, by-pass, deposition and preservation processes. Unlike the neighbouring Rhone deposits that display numerous thick deltaic sequences related to a continuous sediment flux, the Maguelone shore exhibits peculiar sedimentary bodies. The analysis of about 250 km of new VHR seismic profiles acquired over the study area, 9 short cores and outcrops data allowed us to determine the three-dimensional high-resolution geometry of the coastal system tracts from Quaternary to present-day. This revealed dominant denudation processes in the Upstream catchments associated with the formation of incised valleys during Quaternary lowstands. In addition, this study investigates the erosion and deposition mechanisms controlled by littoral hydrodynamics that have been taken place on this shore since the last transgression. In particular, metre-high and hundreds of metre-long sandy bodies constructed by alongshore hydrodynamics were identified and their effect on the morphodynamics of the whole littoral system is discussed. The Maguelone shore can be used as an experimental study for onshore/offshore dynamics under the influence of microtidal wave/current hydrodynamics and very low river-derived sediment flux during a eustatic cycle. Geometry of system tracts across flood plain to shoreface is usually considered to be controlled by relative sea-level changes, and is successfully analysed with 2D sequence stratigraphy cross-shore models. It is observed that in areas like the Maguelone shore, traditional sequence stratigraphy methods might not be fully relevant and need to integrate alongshore hydrodynamical processes.
ISSN: 0025-3227

hal-00421060
https://hal.archives-ouvertes.fr/hal-00421060
DOI : 10.1016/j.margeo.2009.06.008

Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. They are organized by geographical location.
Mount Hillaby, whose peak located in Scotland District of the Saint Andrew’s parish, is the highest elevation in Barbados at 340 meters (1115 feet) above sea level. Mount Hillaby, whose soil is composed of sandstone and chalk, is the summit of a mountain range that stretches from Trinidad to Puerto Rico. The Scotland District is the only location in the Caribbean where this mountain range is above water. This range is an example of an accretionary prism which is formed from sediments on the ocean floor pushing together at the junction of two tectonic plates. From Mount Hillaby’s peak viewers can see the beaches of Bathsheba and Chalky Mount, a range of hills with a jagged profile that contains clay deposits used by local potters. Slide labeled Barb 23.
Barbados -- Caribbean region -- Saint Andrew

Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@ucf.edu
CFM1972_01a
Sheet 20: 16
http://ufdc.ufl.edu/AA00017922/00001

Éditeur(s) : HAL CCSD
Résumé : Master
La biodiversité peut être mesurée de nombreuses façons. La dualité entropie-diversité fournit un cadre clair et rigoureux pour le faire. L’entropie est la surprise moyenne fournie par les individus d’une communauté. Le choix de la fonction d’information qui mesure cette surprise à partir des probabilités d’occurence des espèces (ou d’autres catégories) permet de définir les mesures de diversités neutres, fonctionnelles ou phylogénétique présentées ici. L’entropie est transformée en diversité au sens strict par une fonction croissante (l’exponentielle déformée), ce qui simplifie son interprétation en tant que nombre équivalent d’espèces.L’entropie phylogénétique généralise les indices de diversité classique, intègre si nécessaire la distance entre espèces, peut être écomposée et corrigée des biais d’estimation. Sa transformation en diversité au sens strict permet d’interpréter les valeurs sous une forme unique : un nombre équivalent d’espèces et un nombre équivalent de communautés. La diversité de Leinster et Cobbold généralise à son tour la diversité phylogénétique et permet d’autres définitions de la distance entre espèces. Le paramétrage des mesures (l’ordre de la diversité) permet de donner plus ou moins d’importance aux espèces rares et de tracer des profils de diversité.La construction de ce cadre méthodologique est présentée en détail ainsi que plusieurs approches différentes, qui constituent l'état de l'art de la mesure de la biodiversité.
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813
Kourou, France

cel-01205813
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813v2/document
https://hal-agroparistech.archives-ouvertes.fr/cel-01205813/file/Mesures_de_la_Biodiversite.pdf

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : The Maguelone shore extends along the northern coast of the Gulf of Lions margin, West of the Rhone delta and East of some high gradient coastal streams that have been providing most of the elastic sediments to the Gulf of Lions margin since the early Miocene. This 10 km wide area comprises an onshore small coastal watershed (15 km long) in low-lying carbonate hills, kilometer wide marshes, sandy beach and shoreface featuring local low sedimentation. Deposit architecture in such a coastal zone records dynamics of incised valley fill under the influence of rivers and wave/current hydrodynamics in a microtidal environment during an eustatic cycle.;A detailed analysis of about 250 km of very high resolution seismic profiles, tens of cores and outcrops data revealed the evolution of the Maguelone coastal system from Late-Quaternary to present-day. It highlighted also dominant denudation processes in the upstream catchments associated to the formation of incised valley seaward during Quaternary. Combination of this inherited morphology together with hydrodynamics controlled the lagoonal environment evolution since the last transgression. In particular, the Maguelone shore is characterized by the formation of built-over-rias lagoonal systems and records an evolution from partially protected lagoon to isolated lagoon environment. These two stages of lagoon evolution correspond to distinct deposit environments. Correlation of fauna contents with deposit geometry improves lagoonal environment models.
EISSN: 1777-5817

hal-00486370
https://hal.archives-ouvertes.fr/hal-00486370
DOI : 10.2113/gssgfbull.181.2.211

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In this study, we quantify and analyze the spatial and temporal evolution of the surface displacement of Kahrod landslide located in the center of Alborz range (Iran) within the Haraz valley. This landslide represents a threat for this main drainage axis and its numerous infrastructures. We present three sets of displacement vectors based on GPS technique. An 8-benchmark network has been surveyed four times on a 1-year period basis. It provides accurate information on the rate of displacement within the landslide, and addresses the problem of the mechanical resistance of a small hillock, down slope, under the stress imposed by the landslide. Then. this network is densified (57 marks) and measured twice in 6 months using a rapidstatic approach. This yields to a dense description of surface deformation over the whole landslide. Finally, a 1-year time series of permanent GPS recordings is presented and compared to rainfall. Furthermore, we analyze Envisat radar differential interferograms (DInSAR) spanning the same period as permanent GPS. These geodetic data allow to precisely determine the limits of the current sliding zone and to describe the spatial and temporal evolution of surface displacement. The combination of geodesy and field observations leads to a precise description of the past and present kinematics behavior of Kahrod landslide. The chaotic nature of the sliding mass suggests a first catastrophic landslide in a first episode. During the period of observation, the landslide appears to deform quite steadily, and the evidence of short-term correlation between rainfall and deformation amplitude needs to be confirmed by future measurements. Carrying on the acquisition of GPS and InSAR data within the sliding mass but also within adjacent bedrock should give fundamental information with regards to major activation processes (river sapping, water seeping, earthquakes, or failure within the frontal hill of bedrock) and their potential consequences.
ISSN: 1435-9529

hal-00411318
https://hal.archives-ouvertes.fr/hal-00411318
DOI : 10.1016/j.enggeo.2008.02.013

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Measuring functional or phylogenetic diversity is the object of an active literature. The main issues to address are relating measures to a clear conceptual framework, allowing unavoidable estimation-bias correction and decomposing diversity along spatial scales. We provide a general mathematical framework to decompose measures of species-neutral, phylogenetic or functional diversity into α and β components. We first unify the definitions of phylogenetic and functional entropy and diversity as a generalization of HCDT entropy and Hill numbers when an ultrametric tree is considered. We then derive the decomposition of diversity. We propose a bias correction of the estimates allowing meaningful computation from real, often undersampled communities. Entropy can be transformed into true diversity, that is an effective number of species or communities. Estimators of α- and β-entropy, phylogenetic and functional entropy are provided. Proper definition and estimation of diversity is the first step towards better understanding its underlying ecological and evolutionary mechanisms.
ISSN: 2041-210X

hal-01502645
https://hal-agroparistech.archives-ouvertes.fr/hal-01502645
DOI : 10.1111/2041-210X.12323

Éditeur(s) : HAL CCSD
Résumé : International audience
BACKGROUND: Semi Volatile Organic Compounds (SVOCs) are contaminants commonly found in dwellings as a result of their use as plasticizers, flame retardants, or pesticides in building materials and consumer products. Many SVOCs are suspected of being neurotoxic, based on mammal experimentation (impairment of locomotor activity, spatial learning/memory or behavioral changes), raising the question of cumulative risk assessment. The aim of this work is to estimate the relative toxicity of such SVOCs, based on neuronal death. METHOD: SVOCs fulfilling the following conditions were included: detection frequency >10% in dwellings, availability of data on effects or mechanism of action for neurotoxicity, and availability of dose-response relationships based on cell viability assays as a proxy of neuronal death. Benchmark concentration values (BMC) were estimated using a Hill model, and compared to assess relative toxicity. RESULTS: Of the 58 SVOCs selected, 28 were suspected of being neurotoxic in mammals, and 21 have been documented as inducing a decrease in cell viability in vitro. 13 have at least one dose-response relationship that can be used to derive a BMC based on a 10% fall in neuronal viability. Based on this in vitro endpoint, PCB-153 appeared to be the most toxic compound, having the lowest BMC10 (0.072μM) and diazinon the least toxic compound, having the highest BMC10 (94.35μM). We showed that experimental designs (in particular choice of cell lines) had a significant influence on BMC calculation. CONCLUSION: For the first time, the relative in vitro toxicity of 13 indoor contaminants belonging to different chemical families has been assessed on the basis of neuronal cell viability. Lack of comparable toxicity datasets limits the number of SVOCs that can be included. More standardized protocols in terms of cell lines, species and exposure duration should be developed with a view to cumulative risk assessment.
Toxicology Letters

hal-01579605
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01579605
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01579605/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01579605/file/Fournier%20et%20al.%20-%20Relative%20toxicity%20for%20indoor%20semi%20volatile%20organic.pdf
DOI : 10.1016/j.toxlet.2017.07.875

Éditeur(s) : HAL CCSD Wiley
Résumé : Clay shale landscapes are sensitive to landslide, erosion, and re-sedimentation processes. In this context, tectonized clay shales have peculiar hydrological and mechanical behaviours. In order to improve our understanding of the processes involved in such systems, an experimental site has been settled in the Draix Observatory (ORE DRAIX) on a black marl hill slope of the Southern Alps (France) in the framework of the ECOU-PREF project. The site is a natural laboratory to study the evolution of clay shale landscapes at several scales (regional to µm). In this study, we aim to characterize the internal structure and fissure patterns of a stable interfluve, in order to locate preferential water flows within the system, and anticipate its evolution. This work is based on a series of mutli-disciplinary approaches including petrophysical analyses, well pulse injection tests and downhole geophysical measurements. Borehole geophysical results were combined with laboratory measurements on core plugs (permeability, density, porosity, and acoustic velocity). Optical and acoustical images have been used as an original tool for internal discontinuities characterisation and potential active flow path detection. They allowed the identification of three main lithological units interpreted as several stages of shale alteration. In addition, several main structural plane discontinuities (open fractures, schistosity planes, and fractures infilled with calcite or clays) were identified from the images and their potential transmissivity discussed with regard to piezometric and tracer measurements. In all, the integration of measurements leads to propose a simple scenario of fluid circulation and chemical alteration of the interfluve.
ISSN: 0885-6087

hal-00757581
https://hal.archives-ouvertes.fr/hal-00757581
DOI : 10.1002/hyp.7997