Priorités de réduction dans le secteur de l'agriculture de quelques nations caraïbes. ; Mitigation priorities in the agricultural sector of some caribbean nations Auteur(s) : Gob, Rosaire Gouveia, Grégory Année de publication : Loading the player... Éditeur(s) : INRA : Institut National de la Recherche Agronomique Université des Antilles. Service commun de la documentation Extrait de : 52e congrès annuel de la Société caribéenne des plantes alimentaires / 52nd annual meeting of the Caribbean food crops society (CFCS), du 10 au 16 juillet 2016. INRA, CFCS Description : In this study the greenhouse gas emission (GHGE) profiles in the agriculture sector of some Caribbean nations are reviewed and strategies proposed to mitigate climate change are assessed. Twenty-four (24) Caribbean nations were included in an initial assessment to determine their mean GHG emissions in CO2eq over the period 1990-2011 and then ranked according to a range of emission metrics into the highest and lowest emitters. While Caribbean nations have extremely low absolute emissions compared to most other countries/regions, relative to human population, land area and agricultural production, values in the region are comparable to the rest of the world including some of the most populated and largest countries. Eight (8) of the highest emitters were then selected and their National Communications (NC) to the United Nations Framework Convention on Climate Change (UNFCCC) were reviewed (and other sources in the case of Guadeloupe and Puerto Rico) to determine their mitigation priorities. Of the eight, only Guyana, Guadeloupe and Puerto Rico have documented any significant intent to mitigate GHG in agriculture. None however, reviewed their GHG emissions other than in absolute terms. Emissions relative to production (emission/production ratio or intensity ratio) can be particularly useful in providing a better understanding of the areas where mitigation should be prioritized. These mitigation priorities are also more likely to enhance food security goals and also contribute to climate change adaptation. Dans cette étude les profils de l'émission de gaz participant à l'effet de serre (GHGE) dans le secteur d'agriculture de quelques nations des Caraïbes sont passés en revue et des stratégies proposées pour atténuer le changement climatique sont évaluées. Vingt-quatre (24) nations des Caraïbes ont été incluses dans une première évaluation pour déterminer leurs émissions moyennes de GHG dans CO2eq au cours de la période 1990-2011 et puis rangées selon une gamme de la métrique d'émission dans les plus hauts et plus bas émetteurs. Tandis que les nations des Caraïbes ont extrêmement - les basses émissions absolues comparées à la plupart des autres pays/régions, relativement à la population humaine, la région terrestre et la production agricole, valeurs dans la région sont comparables au reste du monde comprenant certains des pays les plus peuplés et les plus grands. Huit (8) des plus hauts émetteurs ont été alors sélectionnés et leurs communications nationales (OR) à la convention-cadre des Nations Unies sur le changement climatique (UNFCCC) ont été passées en revue (et d'autres sources dans le cas de la Guadeloupe et du Porto Rico) pour déterminer leurs priorités de réduction. Des huit, seulement la Guyane, la Guadeloupe et le Porto Rico ont documenté n'importe quelle intention significative pour atténuer GHG dans l'agriculture. Aucun cependant, passé en revue leurs émissions de GHG autres qu'en des termes absolus. À production relative d'émissions (rapport d'émission/production ou rapport d'intensité) peut être particulièrement utile en fournissant une meilleure compréhension des secteurs où la réduction devrait être donnée la priorité. Ces priorités de réduction sont également pour augmenter des buts de sécurité de nourriture et pour contribuer également à l'adaptation de changement climatique. Siècle(s) traité(s) : 21 Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification Permalien : http://www.manioc.org/fichiers/V16246 V16246 | Partager Voir aussi Agriculture biologique Système de culture (agriculture) Agriculture Trinité-et-Tobago Etats-Unis d'Amérique ; Télécharger |
Forum with Parliament Members : Students Against Sexual Orientation Discrimination ; Audio Recordings of the Proceedings Auteur(s) : Caribbean IRN Résumé : From the PNCR, GAP MPs free to vote conscience on gay rights bill
By Johann Earle
Stabroek News
June 11, 2003
The PNCR will allow its members to vote their conscience on the controversial Constitution (Amendment) Act of 2001 which seeks to prevent discrimination against persons on the basis of their sexual orientation and other grounds.
A number of religious organisations are opposed to the passage of the bill because it includes sexual orientation as one of the grounds. They are concerned that it could lead to a legalisation of homosexual relations and demands for recognition of gay marriages among other things.
PNCR Member of Parliament (MP) Vincent Alexander told a forum at the National Library on Saturday, that the Bill did not seek to legalise homosexuality, but to ensure that persons would not be discriminated against based on their sexual preferences.
He was one of two parliamentarians who showed up - the other being PNCR member, Myrna Peterkin.
The forum was organised by Students Against Sexual Orientation Discrimination (SASOD), a group comprising fifteen students from the University of Guyana which was formed about two weeks ago.
Alexander expects the vote on the bill to come up before the National Assembly in a matter of months.
Paul Hardy, Leader of the Guyana Action Party (GAP), told Stabroek News that his party would not be using the so-called parliamentary whip. He added that GAP took a decision that every member should vote according to his or her own conscience. “We have no right to deny the rights of others based on sexual orientation. [The Bill] will guarantee rights to the homosexual.” GAP is in Parliament as part of an alliance with the Working People’s Alliance. GAP/WPA has two MPs.
The bill was met with rejection from some members of the religious community in 2001 and as a result of this, the President did not assent to it.
In a statement on Monday, the Central Islamic Organisa-tion of Guyana (CIOG) said that it stood in firm opposition to the Bill. The CIOG says the general purpose of the bill may be commendable and that the organisation’s objection is not based on a willingness to promote discrimination. Rather, the CIOG said, it was based on the fact that specific legal protection on the basis of sexual orientation without definition or qualification gives tacit legitimacy to practices which are considered criminal in Islam. “It is foreseeable that such a legal nod of approval (subtle as it may be) of these practices may pave the way for greater social (or even legal) acceptability in the future which, from the perspective of all Muslims including those in Guyana, is an undesirable and sinful outcome,” the CIOG statement said.
At Saturday’s event, Muslim teacher Moulana Mohamed Ali Zenjibari spoke of instances of abuse, discrimination and harsh penalties meted out to gay and lesbian persons in countries such as Iran and Saudi Arabia and noted that the Quran did not sanction such punishments for homosexual behaviour.
President of the CIOG, Fazeel Ferouz told Stabroek News that a meeting to discuss a strategy with regards to the bill was planned for tomorrow with various religious groups.
Stabroek News tried to get a comment on the issue from the PPP/C but to no avail.
ROAR leader, Ravi Dev said that his party was now having discussions on the issue. ROAR feels that it is an important question which has to do with morality and should be discussed across the country. He added legislators had to be in tune with their constituents on the issue.
SASOD is lobbying for the legislation through the sensitisation of MPs.
Keimo Benjamin, a law student at UG, gave a presentation based on the jurisprudential aspects of the discussion on sexual orientation. He argued that morality should not be the only guiding principle on which to base the laws. Sexual activities between two consenting male adults in private could not be equated with a violation of a person’s rights, he said, making the point that the thrust of his presentation was not whether homosexuality was wrong, but whether it violated the rights of others. He said that the attitudes of some towards this subject were based on preconceived notions and prejudices. He cited studies to show that the suppression of certain perceived deviant sexual impulses in persons might do more harm than good. One Harvard University study of teens who said they were gay indicated that those teens were three times more likely to commit suicide.
Vidyaratha Kissoon, of Help and Shelter, in his contribution on Saturday, expressed his displeasure at the low turnout at the forum and urged the parliamentarians who showed up to take the message to their colleagues. He noted that because of homophobia, the numerical minority was terrified of speaking out against instances of discrimination. Gays and lesbians in Guyana were subjected to ridicule and abuse, and walk the streets at night not looking for sex necessarily, but for the companionship of persons who empathise with them.
During his presentation, Joel Simpson, another member of SASOD, outlined a number of changes made within national jurisdictions that had international implications. One such crucial change was South Africa’s 1996 adoption of a new constitution, making that country the first in the world to expressly include sexual orientation as a prohibited ground of discrimination. It was the first time a developing country had taken the lead with respect to the rights of sexual minorities.
He also said that according to Douglas Sanders, a Canadian jurist, the rights of homosexual, bisexual or transsexual men and women had never been officially recognised by the United Nations, despite the fact that international laws on the issue began to emerge at the close of the Second World War.
Simpson said that under Article 170 (5), as amended by Section 8 of the Constitution (Amendment) (No. 4) Act 2000, the President is required to assent to any bill which is returned by the National Assembly unaltered after a two-thirds majority within 90 days of its presentation to him. To the parliamentarians present, Simpson stressed that the onus was now on them to adequately represent their constituents which include lesbian, gay, bisexual and transsexual Guyanese.
http://www.landofsixpeoples.com/news301/ns306115.htm
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Vote on sexual orientation should be a matter of conscience - MP Alexander
By Esther Elijah
Guyana Chronicle
June 8, 2003
PEOPLE’S National Congress (PNC/R) Member of Parliament Mr. Vincent Alexander, said the Opposition will vote on “conscience” when the piece of legislation on sexual orientation is again brought before the National Assembly.
“With specific reference to my party, when this Bill gets back to the Parliament in the spirit of the arguments here, we will not use the `whip’. Our party will not say we have to vote for the provision (in the Sexual Orientation Bill). We will allow our members to vote as a matter of conscience,” he told participants gathered in the Conference Room of the National Library.
“We feel this is a matter of conscience. You may end up with a collective position but you have to deal with us individually,” Alexander said at a poorly attended public consultation aimed at gaining support for sexual orientation to be considered a fundamental right in Guyana.
Alexander, one of the main persons who sat on the Constitutional Reform Commission that addressed this controversial clause, said the legislation was not meant to legalise homosexual activities in Guyana.
“It was intended to ensure that persons who have an orientation - a way of thinking - which may or may not lead to a certain activity, to not be discriminated against, in terms of their rights,” he explained.
Alexander noted that very often, discussions on the sexual orientation provision in the Bill have led to seepages into other areas where debates centre on the “right to be homosexual.”
“I am saying the Bill does not comment on that… However, law is peculiar, especially in a Common Law system. Once you venture out and change the law, very often you open other windows which we cannot definitively say exist or does not exist in advance,” he said.
“The fear of some people is that the legislators might say one thing and the Courts will eventually say something else. While some people can’t argue against the law, per say, they will say this has opened a window of opportunity not meant to be opened. So, it is better to stay without a window than open it and then have a possibility of something you didn’t intend to happen - happening sometime in the future.”
Alexander added: “I want to say I’ve found this activity to have been rich from the perspective of the amount of research which was done by student (speakers). Without any comment as to whether I agree with the arguments, I would wish that much more research on other issues be done by students, and that at the University (of Guyana) students would find it convenient to have forums on other issues, with the same depth of research for their own intellectual development.”
Alexander and other Opposition M.P, Lurlene Nestor were the only three Parliamentarians in attendance at the session organised by the recently formed `Students Against Sexual Orientation Discrimination’ (SASOD), a group that has a membership of 15 mostly University of Guyana (UG) students from various faculties.
SASOD was established two weeks ago.
With the exception of members of the press, the consultation only managed to attract 11 persons, a handful of who were SASOD members.
While congratulating the students for an “insightful” presentation, Nestor pointed out that whether or not she chooses to agree with their position is “another issue” and she is entitled to her “own view”.
“The issue of sexual orientation is very `toucheous’ …while we agree with the human rights provisions and all that as a society, we must also revert to our own society. Some of the very critical questions that I would want to ask is whether or not at the society (level) we are ready for that kind of thing,” she remarked.
“We cannot, at (any) time, ignore the religious groups in our society. If we look at statistics going back to 1992 from a survey done by the Bureau of Statistics, we would see that a small section of the Guyanese population might be considered as people who do not subscribe to a religious view. While the laws are not necessarily based on moral values, we must acknowledge the fact that we might want to revert to many of the cases that (concern) laws that protect public morality.”
Nestor told the speakers at the consultation these were some of the issues that they needed to deal with.
She highlighted, too, that what must be examined is the effects of same-sex marriages on society and how this issue must be tackled.
“These are some of the things we should consider and I don’t think you dealt with that in the presentations,” Nestor stated, adding that the issues must be addressed “frontally.”
“Do we think that with the coming to being of this Bill that there might be quite a number of challenges to the Constitution in relation to the same issue of a man marrying a man? What do we do at the society (level)? Do we recognise that?” were the questions directed at the five speakers at the session.
Nestor continued: “There is some argument that says, `Oh the Bill does not promote homosexuality or does not encourage a man to marry (another) man, but if you look at Section (15) that talks about `non-discrimination’ then how can we not, with the passage of this Bill, allow a man not to marry (another) man.”
According to Nestor, matters of this nature constitute some of the “inconsistencies” of the Bill.
On the argument raised by presenters at the session on who determines what is morality, Nestor said in the concept of democracy it is the people who are the determinants based on a “line of thinking.”
She also rebutted on grounds that put the spotlight on teachers who may have been caught “interfering” with their young students and who may subsequently be dismissed from their jobs.
“Could you imagine such a person interfering with a boy below age 10 - and by virtue of the fact that the Bill is there, the judges (in the case) will have to use their discretion in terms of what happens. We will have more Constitutional changes and problems (arising with the passage of the Bill).”
SASOD member and law student, Joel Simpson, in reply, said he doesn’t think any homosexual in Guyana wants to “run into a church and ask that people marry them or anything of that sort.”
At one point likening the church to a “club”, Simpson claimed the church has the right to exclude whomever it wants. He further stated that in accordance with the Constitution, people of the same sex do not currently have the right to marry, and will also not be able to do such an act with the passage of the Bill.
However, Simpson said it is possible that the law, with the passage of the Bill, would have to recognise same-sex domestic partnerships in relation to employment benefits, sharing of properties, etc.
Simpson said he believes there should be a realm of “public” and “private” morality between consenting adults, and implied that the Bill did not fully give “rights” to homosexuals.
But, Nestor interjected: “I am informing you further…that the Sexual Orientation provision has, in fact, in some way recognised the rights of homosexuals and we must accept that.”
Meanwhile, there was no vocal Christian representative(s) at the consultation and apart from the two Opposition representatives none other participant gave comments or directed questions at the presenters.
Other speakers in support of the sexual orientation clause were: Moulana Mohammed Ali Zenjiban, Assistant Director of the International Islamic College; Denuka Radzik from Red Thread, Keimo Benjamin, UG law student and Vidyartha Kissoon from Help & Shelter.
The Sunday Chronicle has been reliably informed that the Georgetown Ministers Fellowship, representing groups of Christian leaders staunchly against sexual orientation as a right in Guyana, have recently prepared a detailed 16-page document outlining issues arising from research to further boost their argument against the inclusion of the clause.
The document is yet to be made public.
http://www.landofsixpeoples.com/news301/nc306083.htm Droits : All rights reserved by the source institution. http://ufdc.ufl.edu/AA00014700/00001 | Partager |
Implementing cropping systems to improve sustainable agriculture in the tropics and subtropics ; Mettre en ?uvre des systèmes de culture pour améliorer l'agriculture durable dans les régions tropicales et subtropiques Auteur(s) : Wang, Qingren Année de publication : Loading the player... Éditeur(s) : University of Florida Université des Antilles. Service commun de la documentation Extrait de : 52e congrès annuel de la Société caribéenne des plantes alimentaires / 52nd annual meeting of the Caribbean food crops society (CFCS), du 10 au 16 juillet 2016. INRA, CFCS Description : Under tropical and sub-tropical climates, a sustainable development of agriculture is challenging because of the pest pressure with favorable weather conditions. Implementation of appropriate cropping systems including growing cover crops and crop rotation plays a critical role, which can break up the food chain and life cycles of field pests. Some field trials have demonstrated that among all tested summer cover crops, sunn hemp (Crotalaria juncea L. cv. Tropic sun) can grow vigorously during the rainy summer, cover the land quickly and densely, and it can produce a large quantity of biomass in two to three months. More importantly, sunn hemp can suppress soil root-knot nematodes via releasing some nematicides through its roots and through the decomposition of plant residues. Therefore, growing cover crop â? ? sunn hemp during the crop off season and rotating with valuable vegetable crops in the growing season has become a promising cropping system under the subtropical climate. Such a result may have a potential to be implemented in Caribbean countries to improve the sustainable development of agriculture. Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification Permalien : http://www.manioc.org/fichiers/V16313 V16313 | Partager |
Mercury in the Lot-Garonne River system (France): Sources, fluxes and anthropogenic component Auteur(s) : Schafer, Jörg Blanc, Gerard Audry, S Cossa, Daniel Bossy, C Éditeur(s) : Elsevier Résumé : Dissolved and particulate Hg fluxes in the Lot-Garonne-Gironde fluvial-estuarine system were obtained from observation of daily discharge and suspended particulate matter (SPM) concentrations. In addition to the measurements of the total dissolved (< 0.45 gm) and particulate Hg (> 0.45 gm), called HgTD and HgTp respectively, the dissolved inorganic Hg species (HgRD) were determined monthly. Geochemical background values for HgTp in sediments and SPM were similar to crustal values and to typical concentrations in SPM of non-contaminated river systems, respectively. The Riou Mort watershed already known as the origin of important historical polymetallic (e.g., Cd, Zn) pollution was identified as an important Hg point source. In the downstream Lot River, Hg concentrations were clearly higher than those in other moderately contaminated systems. The mean relative contribution of HgRD to HgTD in the Lot River and in the Garonne River was close to 25% and 50%, respectively, and showed no correlation with water discharge or SPM concentration. Depending on the origin and nature of SPM, HgTp concentrations were correlated or not with particulate organic C (POC). Maximum HgTp concentrations were measured in samples containing low POC concentrations and were attributed to sediment resuspension. In contrast, high POC concentrations (6-17%) during algal blooms were associated with low/moderate HgTp concentrations (< 0.5 mg kg(-1)) at different sites, suggesting that Hg concentrations in fluvial phytoplankton may be limited by bioavailability of dissolved Hg and/or physiologically controlled Hg accumulation. Mercury was mostly (up to 98%) transported in the particulate phase with estimated annual Hg fluxes at the outlet of the Lot River system ranging from 35 to 530 kg a(-1) for the past decade. The minimum anthropogenic component (58-84% of total Hg fluxes) could not be explained by present Riou Mort point source contributions, suggesting important Hg release from contaminated sediment as a major source and from downstream point sources (e.g., coal-fired power plants and/or metal processing industries). HgTp concentrations and fluxes were strongly related to hydrologic variations and were clearly increased by riverbed dredging during lock construction. Therefore, the estimated Hg stocks in the Lot River sediment (5-13 tons) represent an important potential Hg source for the downstream fluvial-estuarine system. Applied Geochemistry (0883-2927) (Elsevier), 2006-03 , Vol. 21 , N. 3 , P. 515-527 Droits : 2006 Elsevier Ltd All rights reserved http://archimer.ifremer.fr/doc/2006/publication-1343.pdf DOI:10.1016/j.apgeochem.2005.12.004 http://archimer.ifremer.fr/doc/00000/1343/ | Partager |
Ab initio elastic properties of talc from 0 to 12 GPa: Interpretation of seismic velocities at mantle pressures and prediction of auxetic behaviour at low pressure Auteur(s) : Mainprice, Dave Le Page, Y. Rodgers, J. Jouanna, P. Auteurs secondaires : Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Institute for Chemical Process and Environmental Technology ( ICPET) ; National Research Council of Canada (NRC) Toth Information Systems Inc., Ottawa ; Université du Québec Éditeur(s) : HAL CCSD Elsevier Résumé : International audience Talc is a hydrous magnesium rich layered silicate that is widely disseminated in the Earth from the seafloor to over 100 km depth, in ultra-high pressure metamorphism of oceanic crust. In this paper we determine the single crystal elastic constants at pressures from 0 to 12 GPa of talc triclinic (C 1¯) and monoclinic (C2/c) polytypes using ab initio methods. We find that talc has an extraordinarily high elastic anisotropy at zero pressure that reduces with increasing pressure. The exceptional anisotropy is complemented by a negative Poisson's ratio for many directions in crystal space. Calculations show that talc is not only one of very few common minerals to exhibit auxetic behaviour, but the magnitude of this effect may be the largest reported so far for a mineral. The compression (Vp) and shear (Vs) wave velocity anisotropy is 80% and 85% for the triclinic polytype. At pressures where talc is known be stable in the Earth (up to 5 GPa) the Vp and Vs anisotropy is reduced to about 40% for both velocities, which is still a very high value. Vp is slow parallel to the c-axis and fast perpendicular to it. This remains unchanged with increasing pressure and is observed in both polytypes. The shear wave splitting (difference between fast and slow S-wave velocities) at low pressure has high values in the plane normal to the c-axis, with a maximum near the alow asterisk-axis in the triclinic and the b-axis in the monoclinic polytype. The c-axis is the direction of minimum splitting. The pattern of shear wave splitting does not change significantly with pressure. The volume fraction of talc varies between 11 and 41% for hydrated mantle rocks, but the lack of data on the crystallographic preferred orientation (CPO) precludes a detailed analysis of the impact of talc on seismic anisotropy in subduction zones. However, it is highly likely that CPO can easily develop in zones of deformation due to the platy habit of talc crystals. For random aggregates of talc, the isotropic Vp, Vs and Vp/Vs ratio have significantly lower values than those of antigorite and may explain low-velocity regions in the mantle wedge. Vp/Vs ratios are more complex in anisotropic media because there are fast and slow S-waves, resulting in Vp/Vs1 and Vp/Vs2 ratios for every propagation direction, making interpretation difficult in deformed polycrystalline talc with a CPO. Talc on the subduction plate boundary can strongly influence guided wave velocity as CPO would develop in this region of intense shearing. The very low coefficient of friction (< 0.1) of talc above 100 °C could also explain silent earthquakes at shallow depths (ca 30 km) along the subduction plate boundaries, frequently responsible for tsunami. ISSN: 0012-821X hal-00411481 https://hal.archives-ouvertes.fr/hal-00411481 DOI : 10.1016/j.epsl.2008.07.047 | Partager |
Predicted glide systems and crystal preferred orientations of polycrystalline silicate Mg-Perovskite at high pressure: Implications for the seismic anisotropy in the lower mantle Auteur(s) : Mainprice, Dave Tommasi, Andrea Ferre, D. Carrez, P. Cordier, P. Auteurs secondaires : Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Laboratoire de structures et propriétés de l'état solide (LSPES) ; Université de Lille, Sciences et Technologies - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Elsevier Résumé : International audience We use first first-principle methods and the Peierls-Nabarro model to evaluate the resistance to glide, characterized by the Peierls stress, of glide systems for end-member MgSiO3 Perovskite at mantle pressures. [010](100) is the easiest glide system in Mg-Perovskite at all pressures. Peierls stresses increase systematically with pressure for all systems except [001](010), indicating the importance of lattice friction at lower mantle pressures. The ratio of the maximum Peierls stress for each system relative to the [010](100) value defines their critical resolved shear stress (CRSS). These CRSS are used in a visco-plastic self-consistent homogenization model to predict the evolution of crystal preferred orientations (CPO) during deformation of polycrystalline Mg-Perovskite. In axial compression, [100] tends to align with the compression direction, in agreement with in situ observations in axial compression experiments. In simple shear, [010] concentrates near the shear direction and (100), although more dispersed, tends to align near the shear plane, consistent with the dominant activity of the easier [010](100) system. The calculated seismic anisotropy for a 100% Mg-Perovskite aggregate using the CPO in simple shear and the elastic constants Of MgSiO3 perovskite at lower mantle pressures and temperatures is weak (>3% for P-waves with and >2% for S-waves) and decreases with increasing temperature and pressure. P-waves show the fastest propagation parallel to the lineation and S-waves fast polarization is in the foliation at 38 GPa and normal to the lineation at 88 GPa. This weak anisotropy is consistent with global seismological observations of a nearly isotropic lower mantle. There are however two regions where strain-induced Mg-Perovskite CPO could contribute to anisotropy; a) low temperature regions in the uppermost lower mantle, where the predicted S-wave polarization anisotropy may attain 1.6% with a fast polarization parallel to the foliation, b) in high high-temperature domains in the D '' layer, where Mg-Perovskite may be the major stable phase, leading to polarization of fast S-waves normal to the lineation for propagation directions at high angle to the lineation and an apparent isotropy for all other propagation directions. ISSN: 0012-821X hal-00411460 https://hal.archives-ouvertes.fr/hal-00411460 DOI : 10.1016/j.epsl.2008.03.058 | Partager |
Les zones de tolérance à Cuba sous la république : l’enfermement réel et symbolique des femmes publiques Auteur(s) : Moreau-Lebert, Mélanie Éditeur(s) : Université des Antilles Études caribéennes Résumé : La prostitution est une problématique très intéressante d’une part parce qu’elle est transversale à tous les temps, à toutes les classes sociales, à tous les espaces, et d’autre part parce qu’il s’agit d’un fléau qui se conjugue le plus souvent au féminin. Il s’agit à mon sens du versant spécifique d’une problématique universelle dont personne ne peut s’affranchir sans mettre en jeu l’ensemble de la condition humaine. En effet, la prostitution est le lieu où convergent et se concentrent de façon exacerbée tous les maux d’une société. La femme est malgré elle au centre de ce système dans lequel on retrouve les frustrations, les rapports de domination, de pouvoir, la violence, la misère, la corruption, l’aliénation… La prostitution, tout comme le concept de genre, est une construction sociale, dans laquelle les femmes sont enfermées réellement et symboliquement.D’autre part, si les maux d’une société sont décuplés dans le système de la prostitution, nulle part ailleurs n’existe un tel abîme entre fantasme et réalité. C’est le lieu des fausses représentations et des euphémismes comme le montrent ces deux expressions édulcorées « zones de tolérance » et « femmes publiques ». A Cuba, malgré les tentatives d’éradication de la prostitution dans les premières décennies qui suivirent le triomphe de la Révolution de 1959, la chute du bloc soviétique et la période de pénurie qui s’ensuivit donnèrent lieu à un retour de cette prostitution, sous de nouvelles formes qui persistent aujourd’hui. Cependant, il fut une époque, celle de la première République (1902-1958) durant laquelle Cuba, rongée par un système néocolonial, connût une recrudescence de ce phénomène, dans des proportions jamais égalées. Une époque somme toute récente où les zones de tolérance, espaces où étaient regroupées les maisons closes, occupaient une grande partie de La Havane coloniale ainsi que des quartiers entiers à travers l’île. A l’intérieur de ces zones très lucratives dont profitaient à la fois les proxénètes, policiers, politiques et hommes d’affaires, les femmes cubaines, mais également, dans une grande proportion des Françaises victimes de la traite des Blanches, se trouvaient au cœur d’un système qui étaient à lui seul le symptôme de la frustration néocoloniale, mais également de l’exacerbation du patriarcat.Cette problématique, on ne peut plus actuelle, convoque la pluridisciplinarité, c’est pourquoi j’ai eu recours à des témoignages de prostituées depuis le début du siècle jusqu’à la Révolution, recueillis et publiés à Cuba. Je me suis penchée sur les différents discours sur la prostitution de l’époque, discours politiques et féministes. Les rapports de police, les plaintes déposées par des femmes, les comptes rendus de procès, et les descriptions des médecins-hygiénistes sont autant de sources qui viennent corroborer les témoignages. The republican era in Cuba is a complex and difficult one for the Cuban population. 1898 remains engraved in people’s memories as being a time of great disillusion for a population who, having freed itself from Spanish colonial domination, was deprived of independence by the United States of America. Three years of American intervention sufficed to put power bases into place, guarantee maximal exploitation conditions and organize the legal framework of the American domination over Cuba by means of the Platt Amendment in 1901. The protectorate set up by the United States, followed by a neocolonial system in 1934, relies upon the collaboration of presidents and corrupt governments succeeding each other in power. Corruption, nepotism and violence are put in place in a society in which inequality is dramatically worsening and all moral values are disintegrating. In this context and in a Cuban society governed with patriarchal rules, women are the first victims of the system. After the wars of independence, the only options they have are marriage, work or prostitution. Legitimate marriage is only available to a privileged few. With regards to employment, only 9.8% of women have the opportunity to work and this percentage didn’t change until 1959. It was at this time that prostitution reached unprecedented levels. It wasn’t just the case of a few marginalized women but of thousands of mothers, wives, widows and working women who were trapped in this alienating condition, forced to sell their bodies. Legislation and violence are used to control and restrict the work space for prostitutes, removing these ‘streetwalkers’ from the public eye, grouping them together in tolerance zones with very strict rules, which are in reality in the hands of Cuban and French procurers, and subjecting them to constant inspections carried out by hygienists who physically and symbolically assault women’s bodies. What is more, speeches about prostitution, whether made by politicians, feminists, journalists, doctors or mere observers, contribute significantly to a certain representation of these women. While debates about prostitution have recently shaken public opinion, this work refers back to an episode of Cuba’s history which brings us to reflect upon the evolution of the phenomenon and on its protean nature. Cuba Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.6945 http://journals.openedition.org/etudescaribeennes/6945 | Partager |
Coral garden economies: international tourism and the magic of tropical nature Auteur(s) : Picard, David Éditeur(s) : Université des Antilles Études caribéennes Résumé : This paper aims to explore the complex relationships between international tourism and the production and exchange of 'nature' in tropical countries. It is based on data gathered through an ethnographic case study approach on the changing aesthetic, economic and symbolic values attached to the coral reef in the tropical island of La Réunion, Indian Ocean. The analysis of this data shows that, from the point where the collective imaginaries in the Western world associate a 'magic' value with corals, an international institutionalisation process takes place in order to protect and preserve coral reefs and make them touristically accessible. This raises important issues related to the challenges the new value of tropical nature represents for the communication and exchange systems of communities in tropical countries. The paper first explores the meanings of the spiritual and religious value Western societies attribute to coral reefs. It then discusses the institutionalisation of tropical nature by international organisations and the problem of parallel land and natural space ownership systems in La Réunion. After that, it deconstructs the mystification policy of the coral reef operated by local institutions in La Réunion and examines the meaning of protecting the coral reef as a socially embedded 'communicative action' in La Réunion. L’objectif de cette étude est d’explorer les relations complexes entre d'une part le tourisme international et d'autre part la production et l'échange de 'nature' dans des pays tropicaux. L'étude est basée sur des données recueillies à travers une approche ethnographique des valeurs esthétiques, économiques et symboliques attachées au récif corallien de l'île de La Réunion, dans l'océan Indien. L'analyse de ces données montre qu'à partir du moment où les imaginaires collectifs de l'Occident associent les coraux à une valeur 'magique', un processus d'institutionnalisation internationale s’engage dans le but de protéger, préserver et rendre accessibles au tourisme les récifs coralliens. Ceci implique des problématiques importantes liées à la mise à l'épreuve des systèmes de communication et d'échange des sociétés dans les pays tropicaux. L'étude explore d'abord la signification des valeurs spirituelles et religieuses qu'attribuent les sociétés occidentales aux récifs coralliens. Ensuite, elle discute l'institutionnalisation de la nature tropicale par des organisations internationales ainsi que le problème de l'existence de différents systèmes de gestion foncière à La Réunion. Enfin, l'étude déconstruit la politique de mythification du récif corallien mise en œuvre par des institutions locales à La Réunion et examinera la signification de 'protéger l'environnement' en tant qu'action communicante définie par les systèmes de communication et d'échange réunionnais. Réunion Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.1112 http://journals.openedition.org/etudescaribeennes/1112 | Partager |
La dynamique des pêches côtières du pays bigouden Auteur(s) : Charuau, Anatole Résumé : In the beginning, the coastal fleet of the Bigouden region fished by trawling and was completely focused on exploiting lobster and hake. It is a traditional business that expanded between the last war and the 70s, reaching its peak between 1975 and 1980.
The best image to give an idea of this fleet is that of a "bucket waterwheel" endlessly discharging its catch in the four ports of the Guilvinec district. Where there is a seafaring business in Guilvinec, Loctudy and Saint-Guénolé, there is a complementarity that is expressed in two ways:
- coastal fishing constitutes a very noticeable and regular supplement to production, since sales happen daily and only bad winter weather causes a relative decrease in the supplement. - coastal fishing gives a flattering image of the port based on the display of high-quality leading market products: daily live lobster, hake and angler.
In this study, we have above all tried to evaluate the situation of the Bigouden coastal system as an entity, while including in the same analysis the species, fleets and the exploitation of the resource. For the main species, a balance sheet is proposed. It covers the lobster, hake and angler separately. Lobster, because of its small amount of movement, can be considered as being an isolated stock, while fish belong to much more wide-ranging groups.
The lobster has gained from various increases in meshing that have been imposed since 1971, even if these have not always been strictly applied. One of the results of this management by means of meshing is a "depreciation" of the variations of daily yields around an average value of 100kg.
For the hake, the dominant trait is an increase in yields in the last few years in accordance with an improvement of the situation in the Gulf of Gascony due to a generalised decrease of effort and a modification of the exploitation profile since the appearance of boulters and straight nets. Whereas the situation for lobster fisheries, as regards the hake's marketable size, did not improve, since the demand for small hake still exists, we have nonetheless been witnessing for about ten years a slow diversification of the fleets' business activities, which is much more in line with sequential hake fisheries' logical outline of exploitation. When lobster yields decrease, one part of the fleet focuses on the fish at the edges of the lobster fisheries.
For the angler, we see rather similar phenomena and a significant increase in unloading of the two species by lobster fishermen due also to a widening of their fishing areas. On the lobster mudflats themselves, there is no notable change in exploitation in the historical records. All studies of coastal fishing always come up against the problem of acquiring statistical data and the Bigouden region is no exception to the rule.
To improve this situation, in 1987 and 1988 two items were chosen:
- a better awareness of the activity and of the areas frequented, by survey during unloading in Guilvinec and in Loctudy.
- a detailed description of the haul by species, by sampling, in Loctudy, on two-thirds of coastal sales, between December 1987 and November 1988.
For this reason, analysis of fleets by type is still cursory and covers only one year. The appearance of new trends towards fish can only be described qualitatively, since there is no historical record. The classification of boats was done by analysing data furnished by the auctions. This first assessment is not necessarily reliable, above all because of the auctions' inaccurate description of the hauls, a deficiency that we have tried to overcome by surveying in Loctudy.
In conclusion, we are witnessing in the Bigouden region, as in other entities, a rebalancing between traditional business activities and modern trends. Lobster fishing, almost exclusive before the 1980s, is tending to decrease for two main reasons:
- a generalised decrease in activity in the lobster fisheries due to non-renewal of coastal fish fleets,
- The transfer of part of the lobster fishermen's activities to fish, since the lobster and its accompanying catch no longer seemed able to insure the economic viability of new ships.
Other maritime districts resolved their lobster problem in a different way. The Lorient fishermen improved their yields by using more capable trawlers, the fishermen of Sable by exploiting the hake fish run to the fullest and limiting their lobster fishing to the best season. The Bigouden region is slowly turning to the second solution, as it renews its fleet.
A ses origines, la flottille côtière du pays bigouden péchant au chalut, est tout entière orientée vers l'exploitation de la langoustine et du merlu. Il s'agit d'une activité traditionnelle qui s' amplifie entre la dernière guerre et les années 70 pour atteindre son apogée entre 1975 et 1980. La meilleure image que l'on puisse donner de cette flottille est celle d'une "noria" débarquant inlassablement sa capture dans les quatre ports du quartier du Guilvinec. Là où existe une activité hauturière à Guilvinec, Loctudy et Saint-Guénolé, il y a une complémentarité qui s'exprime de deux manières : - la pêche côtière constitue un appoint très appréciable et régulier de production, puisque la vente est quotidienne et que seules les intempéries hivernales entraînent une baisse relative des apports. - la pêche côtière donne du port une image flatteuse basée sur la présentation de produits d'appel de grande qualité : langoustine vivante, merlu et baudroies quotidiens. Dans cette étude, nous avons surtout tenté de faire le point sur le système côtier bigouden en tant qu'entité, en englobant dans la même analyse des espèces, les flottilles et l'exploitation de la ressource. Pour les espèces principales, un bilan est proposé. Il couvre séparément la langoustine, le merlu et les baudroies. La langoustine, en raison de ses faibles déplacements, peut être considérée comme constituant un stock isolé, alors que les poissons appartiennent à des ensembles beaucoup plus vastes. La langoustine a beaucoup gagné des diverses augmentations de maillage qui ont été imposées depuis 1971, même si elles n'ont pas toujours été appliquées avec rigueur. Un des résultats de cette gestion par les maillages est un "amortissement" des variations des rendements journaliers autour d'une valeur moyenne de 100 kg. Pour le merlu, le trait dominant est une augmentation des rendements dans les dernières années en accord avec une amélioration de la situation dans le Golfe de Gascogne due à une baisse généralisée de l'effort et à une modification du profil d'exploitation depuis l'apparition des palangriers et des filets droits. Si la situation sur les pêcheries de langoustine, au regard de la taille marchande du merlu, ne s'est pas améliorée puisque la demande de petits merluchons existe toujours, on assiste par contre depuis une dizaine d'années à une diversification lente des activités des flottilles entrant beaucoup mieux dans le schéma logique d'exploitation des pêcheries séquentielles de merlu. Quand les rendements en langoustine baissent, une partie de la flottille s'oriente vers les poisson sur les marges des pêcheries de langoustine. Pour les baudroies on observe des phénomènes assez analogues et une augmentation importante des débarquements des deux espèces par les langoustiniers due également à un élargissement de leurs zones de pêche. Sur les vasières à langoustine elles-mêmes, il n'y a pas de modification notable de l'exploitation dans la série historique. Toute étude des pêches côtières se heurte toujours au problème d'acquisition des données statistiques et le pays bigouden n'échappe pas à la règle. Pour améliorer cette situation, en 1987 et 1988, deux points ont été retenus : - une meilleure connaissance de l'effort et des zones fréquentées, par enquête au moment des débarquements à Guilvinec et à Loctudy, - une description détaillée des apports par espèce, par échantillonnage, à Loctudy, sur les 2/3 des ventes côtières, entre décembre 1987 et novembre 1988. Pour cette raison, l'analyse de flottilles en types est encore sommaire et n'a porté que sur une année. L'apparition des tendances nouvelles vers le poisson ne peut être décrite que qualitativement puisque la série historique n'existe pas. La classification des bateaux a été faite par l'analyse des données fournies par les criées. Ce premier diagnostic ne présente pas toutes les garanties en raison surtout d'une description peu fidèle des apports par les criées, déficience que l'on a essayé de pallier en enquêtant à Loctudy. En conclusion, on assiste dans le pays bigouden comme dans d'autres entités à un rééquilibrage entre les activités traditionnelles et des orientations modernes. La pêche de langoustine, quasi exclusive avant les années 1980, tend à décroître pour deux raisons principales : - une baisse généralisée de l'effort sur les pêcheries de langoustine due au nonrenouvellement des flottilles de pêche côtière, - le report d'une partie de l'effort des langoustiniers vers les pêcheries de poissons, la langoustine et sa capture accessoire ne semblant plus pouvoir assurer la rentabilité économique des navires neufs. D'autres quartiers maritimes ont résolu de façon différente leur problème langoustine. Les Lorientais ont amélioré leurs rendements en adoptant des chaluts plus performants, les Sablais en exploitant à fond la séquence des pêcheries de merlu et en limitant leur intervention sur la langoustine à la saison la plus favorable. Le pays bigouden s'engage lentement dans la seconde solution, au rythme du renouvellement de sa flottille. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1989/rapport-2202.pdf http://archimer.ifremer.fr/doc/00000/2202/ | Partager Voir aussi France Brittany Data Fishing zone Fleet Trawling Commercial species Costal fisheries Finistere Bretagne Télécharger |
The water vapour intercomparison effort in the framework of the Convective and Orographically-induced Precipitation Study: airborne-to-ground-based and airborne-to-airborne lidar systems Auteur(s) : Bhawar, R. Di Girolamo, P. Summa, D. Flamant, Cyrille Althausen, D. Behrendt, A. Kiemle, C. Bosser, P. Auteurs secondaires : Dipartimento di Ingegneria e Fisica dell'Ambiente (Difa) ; Universita degli Studi della Basilicta SPACE - LATMOS ; Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Institut national des sciences de l'Univers (INSU - CNRS) - Centre National de la Recherche Scientifique (CNRS) - Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Institut national des sciences de l'Univers (INSU - CNRS) - Centre National de la Recherche Scientifique (CNRS) Leibniz Institute for Tropospheric Research (TROPOS) Institut für Physik und Meteorologie [Stuttgart] (IPM) ; Universität Hohenheim Deutsches Zentrum für Luft- und Raumfahrt (DLR) Laboratoire d'Opto-électronique et de Micro-Informatique (LOEMI) ; Institut National de l'Information Géographique et Forestière [IGN] (IGN) Dipartimento di Fisica [Roma La Sapienza] ; Università degli Studi di Roma "La Sapienza" [Rome] Risques ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Wiley Résumé : International audience An intensive water vapour intercomparison effort, involving airborne and ground-based water vapour lidar systems, was carried out in the framework of the COPS experiment. The main objective of this paper is to provide accurate error estimates for these systems. Comparisons between the ground-based Raman lidar BASIL and the airborne CNRS DIAL (Differential Absorption Lidar) indicate a mean relative bias between the two sensors, calculated with respect to the mean value of −2.13% (−0.034 g kg−1) in the altitude region 0.5-3.5 km, while comparisons between BASIL and the airborne DLR DIAL lead to a mean relative bias of 1.87% (0.018 g kg−1) in this same altitude region. Comparisons between the ground-based UHOH DIAL and the CNRS DIAL indicate a bias of −3.2% (−0.37 × 1022 m−3) in the altitude range 1.5-4.5 km, while comparisons between the UHOH DIAL and the DLR DIAL indicate a bias of 0.83% (0.06 × 1022 m−3) in this same altitude range. Based on the available comparisons between the ground-based Raman lidar BERTHA and the CNRS DIAL, the mean relative bias is found to be −4.37% (−0.123 g kg−1) in the altitude region 0.5-4.5 km. Comparisons between the ground-based IGN Raman lidar and the CNRS DIAL indicate a bias of 3.18% (0.55 g kg−1) in the altitude range from 0.5 to 4.5 km, while comparisons between the CNRS DIAL and DLR DIAL result in a mean relative bias of 3.93% (1.1 × 1022 m−3) in the altitude interval 0.5-4.0 km. Based on the available statistics of comparisons, benefiting from the fact that the CNRS DIAL was able to be compared with all other lidar systems, and putting equal weight on the data reliability of each instrument, overall relative values for BASIL, BERTHA, IGN Raman lidar, UHOH DIAL, DLR DIAL, and CNRS DIAL, with respect to the mean value, are found to be −0.38, −2.60, 4.90, −1.43, −2.23 and 1.72%, respectively. ISSN: 0035-9009 hal-00572576 https://hal.archives-ouvertes.fr/hal-00572576 DOI : 10.1002/qj.697 | Partager |
Systèmes d'exploitation en pêche côtière ; méthode d'étude et application au cas des Pertuis Auteur(s) : Moussard, F Éditeur(s) : ESITPA, Rouen Résumé : This report presents a functional typology of the exploitation systems of fisheries in the Charentais sounds. It describes the nature of such a typology as well as the method developed in relation to the topic of the study. The determination and formalization accepted to characterise the exploitation systems are outlined. Also presented is the evaluation of the value of the vessels of the sounds fleet. Types are identified based on two main explanatory variables: capital and work. They enable us to set the internal dynamics of the production system straight. Ce rapport présente une typologie dite fonctionnelle des systèmes d'exploitation pour la pêche dans les Pertuis charentais. La nature d'une telle typologie est exposée ainsi que la méthode mise au point en correspondance avec le sujet de l'étude. La détermination et la formalisation retenues pour caractériser les systèmes d'exploitation sont décrites. L'exercice a demandé une évaluation de la valeur des bateaux de la flottille des Pertuis, qui est présentée. Les types sont identifiés en fonction de deux variables explicatives principales, à savoir le capital et le travail. Ils permettent d'éclairer la dynamique interne au système productif. OCR NON CONTRÔLE Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1998/these-3932.pdf http://archimer.ifremer.fr/doc/00000/3932/ | Partager |
Deformation of olivine in torsion under hydrous conditions Auteur(s) : Demouchy, Sylvie TOMMASI, Andréa BAROU, Fabrice MAINPRICE, David Cordier, Patrick Auteurs secondaires : Manteau et Interfaces ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Elsevier Résumé : International audience We performed torsional deformation experiments on pre-hydrated fine-grained olivine aggregates using an innovative experimental assembly to investigate water weakening in mantle rocks at high shear strains. San Carlos olivine powder was cold-pressed and then hot-pressed under hydrous conditions, producing aggregates with average grain sizes of 7 or 15 μm. Deformation experiments were performed in a high-resolution gas-medium apparatus equipped with a torsional actuator, under a confining pressure of 300 MPa, a temperature of 1200 °C, and constant shear strain rates ranging from 8 × 10−5 to 1.4 × 10−4 s−1. Maximum shear stresses range from 150 to 195 MPa. These values are 30% lower relative to those determined in previous torsion experiments on dry, fined-grained dunites under similar conditions. Textures and microstructures of the starting and deformed specimens were characterized by scanning and transmission electron microscopy. All deformed aggregates exhibit a shape-preferred orientation marking a foliation and lineation, as well as a reduction in mean grain size from 15 μm down to 3-4 μm due to dynamic recrystallization. Olivine crystallographic fabrics developed rapidly (γ < 0.1), but their strength, characterized by the J-index, is low compared to naturally deformed peridotites or to polycrystalline olivine deformed at similar finite shear strains under dry conditions. The crystallographic fabrics are consistent with deformation by a dislocation accommodated creep mechanism with activation of multiple {0 k l}[1 0 0] systems, among which the (0 1 0)[1 0 0] slip system is dominant, and minor participation of the (0 1 0)[0 0 1] slip system. Transmission electron microscopy confirmed the occurrence of dislocations with [1 0 0] and [0 0 1] Burgers vectors in most grains. Analysis of unpolarized infrared spectra indicates that hydrogen concentration in the olivine lattice is below the saturation level of 18 ppm wt H2O, which is similar to those typically observed in spinel-bearing peridotite xenoliths, and also provide evidence for water-rich inter-granular material trapped in pores and grain boundaries. Seismic properties computed from the CPO observations correspond to those most commonly observed in naturally deformed mantle peridotites with fast P-wave propagation and S-wave polarization subparallel to the shear direction. These torsion experiments on fine-grained olivine polycrystals under hydrous conditions indicate that water weakening under lithospheric conditions is linked to various defects with hydrogen in the olivine structure, as well as with water-derived species in grain boundaries or pores. ISSN: 0031-9201 hal-00745170 https://hal.archives-ouvertes.fr/hal-00745170 DOI : 10.1016/j.pepi.2012.05.001 | Partager Voir aussi Olivine Water-weakening Simple shear Mantle lithosphere Mantle rheology Crystal-preferred orientation Seismic anisotropy [SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [PHYS.PHYS.PHYS-GEO-PH] Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDE.MCG] Environmental Sciences/Global Changes |
Limited pollen dispersal and biparental inbreeding in Symphonia globulifera in French Guiana Auteur(s) : Degen, Bernd Bandou, Eric Caron, Henri Auteurs secondaires : Ecologie des forêts de Guyane (ECOFOG) ; Ecole Nationale du Génie Rural, des Eaux et des Forêts (ENGREF) - Institut National de la Recherche Agronomique (INRA) - Université des Antilles et de la Guyane (UAG) - Centre National de la Recherche Scientifique (CNRS) Agrosystèmes tropicaux (ASTRO) ; Institut National de la Recherche Agronomique (INRA) UMR INRA / Univ. Bordeaux 1 : Biodiversité, Gènes et Ecosystèmes ; Institut National de la Recherche Agronomique (INRA) Éditeur(s) : HAL CCSD Nature Publishing Group Résumé : In this paper, we report a study of the mating system and gene flow of Symphonia globulifera, a hermaphroditic, mainly bird-pollinated tree species with a large geographic distribution in the tropical Americas and Africa.Using three microsatellites, we analysed 534 seeds of 28 open pollinated families and 164 adults at the experimental site 'Paracou' in French Guiana. We observed, compared to other tropical tree species, relatively high values for the effective number of alleles. Significant spatial genetic structure was detected, with trees at distances up to 150 m more genetically similar than expected at random. We estimated parameters of the mating system and gene flow by using the mixed mating model and the TwoGener approach. The estimated multilocus outcrossing rate, tm, was 0.920. A significant level of biparental inbreeding and a high proportion of full-sibs were estimated for the 28 seed arrays. We estimated mean pollen dispersal distances between 27 and 53 m according to the dispersal models used. Although the adult population density of S. globulifera in Paracou was relatively high, the joint estimation of pollen dispersal and density of reproductive trees gave effective density estimates of 1.6 and 1.3trees/ha. The parameters of the mating system and gene flow are discussed in the context of spatial genetic and demographic structures, flowering phenology and pollinator composition and behaviour. ISSN: 0018-067X hal-01032178 https://hal.archives-ouvertes.fr/hal-01032178 DOI : 10.1038/sj.hdy.6800560 | Partager |
Seasonal Pattern of the Biogeochemical Properties of Mangrove Sediments Receiving Shrimp Farm Effluents (New Caledonia) Auteur(s) : Marchand, Cyril Molnar, N. Deborde, Jonathan Della Patrona, Luc Meziane, Tarik Éditeur(s) : OMICS Publishing Group Résumé : Coastal tropical shrimp farming may impact the adjacent ecosystems through the release of large quantities of effluents rich in nutrients. In New Caledonia, mangroves are considered as a natural biofilter to reduce impacts on the surrounding World Heritage listed lagoon. Our main objective was to understand the influence of effluent discharge on the biogeochemistry of mangrove sediments. A monitoring of the physico-chemical parameters of mangrove sediments was carried out during a whole year, including active and non active periods of the farm. The parameters studied were: i) benthic primary production (Chl-a concentrations), ii) physico-chemical parameters of sediments (redox potential, pH, salinity, TOC, TN, TS, δ13C and δ15N), iii) concentrations of dissolved nitrogen, iron and phosphorus. A mangrove developing in the same physiographic conditions, presenting the same zonation, and free of anthropogenic input was used as reference. The concentration of benthic Chl-a measured at sediment surface in the effluent receiving mangrove was twice to three times that measured in the control zone whatever the season. We thus suggest that nutrients inputs significantly increased the phytobenthic production in the effluent receiving mangrove during the whole year, even after the cessation of discharges and because of natural seasonal dynamic of phytobenthos. Although the flow of surface OM was increased, the OM content at depth was not higher than in the control mangrove. However, the contribution of mangrove detritus to the sedimentary organic pool was higher probably as a result of higher density and much greater individual size of the mangrove trees. Unlike the control mangrove sediment, the effluent receiving mangrove sediment was not stratified, redox potential values were high and presence of Fe3+ was detected down to 50 cm depth, probably as a result of a larger root system, allowing a better sediment oxygenation and accentuated OM decomposition processes, and thus limiting ecosystem saturation. Journal of Aquaculture Research & Development (21559546) (OMICS Publishing Group), 2014-07-03 , Vol. 5 , N. 5 , P. 1-13 Droits : 2014 Marchand C, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. http://archimer.ifremer.fr/doc/00251/36253/34801.pdf DOI:10.4172/2155-9546.1000262 http://archimer.ifremer.fr/doc/00251/36253/ | Partager |
Diagnostic de la contamination chimique de la faune halieutique des littoraux des Antilles françaises. Campagnes 2008 en Martinique et en Guadeloupe Auteur(s) : Bertrand, Jacques Abarnou, Alain Bocquene, Gilles Chiffoleau, Jean-francois Reynal, Lionel Résumé : During the years 1972-1993, kepone a persistent pesticide has been used in the banana fields of the French West Indies (Martinique and Guadeloupe) to content a weevil. A slow desorption of the molecule from soil induces its transfer to the sea through the rivers from leaching and erosion. This study intended to take stock on the contamination by kepone of the fishery species around the islands fifteen years after the kepone ban. Furthermore other chemical pollutants were sought in fish and shellfish around the Martinique island.
The results confirmed persistence of marine fauna contamination by kepone, mainly in the alluvium areas in front of polluted rivers. They shown also that this contamination may spread more widely but with fast decreasing through the marine food webs. For the other pollutants sought, the results were in general lower than the statutory values. Within these substances, only mercury gave a signal close to the prescribed threshold for top predator samples. Finally, on the whole the observed systems appeared preserved from human chemical pollutants, apart from kepone. Pendant les années 1972-1993 un pesticide persistant, la chlordécone, a été utilisé dans les bananeraies des Antilles françaises (Martinique et Guadeloupe) pour lutter contre un charançon. Une désorption lente de la molécule fixée dans les sols conduit à son transfert progressif dans les milieux aquatiques puis vers le domaine marin au gré du lessivage et de l'érosion des sols contaminés. La présente étude visait à faire le point sur la contamination de la faune halieutique côtière des Antilles françaises quinze ans après l'interdiction d'usage de la molécule. En parallèle, une recherche systématique d'autres polluants chimiques a été effectuée sur des poissons et des crustacés ainsi que dans des sédiments autour de la Martinique. Les résultats confirment la persistance d'une contamination de la faune par la chlordécone, particulièrement dans les zones alluvionnaires des cours d'eau contaminés. Ils montrent également que cette contamination diffuse plus largement en s'atténuant, à travers les réseaux trophiques marins. Parmi les autres substances recherchées, les résultats dans les espèces d'intérêt halieutique se situent en général sous les concentrations maximales admissibles fixées par la réglementation. Parmi ces molécules, seul le mercure donne un signal de contamination proche de ce seuil chez des grands prédateurs. Ce constat souligne l'état de préservation des milieux observés vis-à-vis de la contamination chimique environnementale, hormis bien évidemment le cas de la chlordécone. Droits : 2010 Onema / Ifremer http://archimer.ifremer.fr/doc/2009/rapport-6896.pdf http://archimer.ifremer.fr/doc/00000/6896/ | Partager Voir aussi Antilles chlordécone pollution chimique environnement marin Caribbean Kepone chemical pollution Marine environment Télécharger |
From rifting to oceanic spreading in the Gulf of Aden: a synthesis, Auteur(s) : Leroy, Sylvie Razin, Ph. Autin, J. Bache, F. d'Acremont, Elia Watremez, L. Robinet, J. Baurion, C. Auteurs secondaires : Institut des Sciences de la Terre de Paris (iSTeP) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - Centre National de la Recherche Scientifique (CNRS) Environnement, Géo-ingénierie et Développement (EGID) Institut de physique du globe de Strasbourg (IPGS) ; Institut national des sciences de l'Univers (INSU - CNRS) - Centre National de la Recherche Scientifique (CNRS) GNS Science ; GNS Dalhousie University [Halifax] Géosciences Environnement Toulouse (GET) ; Institut de Recherche pour le Développement (IRD) - Université Paul Sabatier - Toulouse 3 (UPS) - Observatoire Midi-Pyrénées (OMP) - Centre National de la Recherche Scientifique (CNRS) Université Pierre et Marie Curie - Paris 6 (UPMC) Institut de Physique du Globe de Paris (IPGP) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - Institut national des sciences de l'Univers (INSU - CNRS) - IPG PARIS - Université Paris Diderot - Paris 7 (UPD7) - Université de la Réunion (UR) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Springer Résumé : International audience We present here a synthesis of the evolution of rifted continental margin systems in the Gulf of Aden. These margins are volcanic to the west of the Gulf of Aden, where they are influenced by the Afar hotspot, and non-volcanic east of longitude 46° E. The combined use of magnetics, gravity, seismic reflection, field observations (tectonic, stratigraphic and sedimentological) and oil well data allowed us to obtain better constraints on the timing of continental rifting and seafloor spreading. From the Permo-Triassic to the Oligocene, the Arabian-African plate was subject to distributed extension, probably due, at least from the Cretaceous, to tensile stresses related to the subduction of the Tethysian slab in the north. In Late Eocene-Early Oligocene, 34-33 Ma ago, rifting started to localise along the future area of continental breakup. Initially guided by the inherited basins, continental rifting then occurred synchronously over the entire gulf before becoming localised on the northern and southern borders of the inherited grabens, in the direction of the Afar hotspot. In the areas with non-volcanic margins (in the east), the faults marking the end of rifting trend parallel to the inherited grabens. Only the transfer faults cross-cut the inherited grabens, and some of these faults later developed into transform faults. The most important of these transform faults follow a Precambrian trend. Volcanic margins were formed in the west of the Gulf, up to the Guban graben in the southeast and as far as the southern boundary of the Bahlaf graben in the northeast. Seaward dipping reflectors can be observed on many oil industry seismic profiles. The influence of the hotspot during rifting was concentrated on the western part of the gulf. Therefore, it seems that the western domain was uplifted and eroded at the onset of rifting, while the eastern domain was characterised by more continuous sedimentation. The phase of distributed deformation was followed by a phase of strain localisation during the final rifting stage, just before formation of the Ocean-Continent Transition (OCT), in the most distal graben (DIM graben). About 20 Ma ago, at the time of the continental break-up, the emplacement of the OCT started in the east with exhumation of the subcontinental mantle. Farther west, the system was heated up by the strong influence of the Afar hotspot, which led to breakup with much less extension. In the Gulf of Aden (s.str), up to the Shukra El Sheik fracture zone, oceanic spreading started 17.6 Ma ago. West of this fracture zone, oceanic accretion started 10 Ma ago, and 2 Ma ago in the Gulf of Tadjoura. Post-rift deformation of the eastern margins of the Gulf of Aden can be seen in the distal and proximal domains. Indeed, the substantial post-rift uplift of these margins could be associated with either the continental break-up, or activity of the Afar hotspot and related volcanic/magmatic activity. Uplift of the northern proximal margin was still active (e.g. stepped beach rocks exposed at 60 m of 2 Ma; 30 m of 35,200 years; 10 and 2 m) and active volcanoes can be inferred at depths of between 70 and 200 km beneath the margin (at 5-10 km distance from the coast). On the distal margin, heat flow measurements show a high value that is associated with post-rift volcanic activity and the development of a volcano (with flows and sills) shortly after the formation of the OCT. The Afar hotspot is therefore important for several reasons. It allows the localisation of deformation along the Red Sea/Aden system and the rapid opening of the Gulf after the continental break-up; its influence also seems to persist during the post-rift period. ISSN: 1866-7411 hal-01053089 https://hal.archives-ouvertes.fr/hal-01053089 DOI : 10.1007/s12517-011-0475-4 | Partager |
Mapping a Knowledge-Based Malaria Hazard Index Related to Landscape Using Remote Sensing: Application to the Cross-Border Area between French Guiana and Brazil Auteur(s) : Li, Zhichao Roux, Emmanuel Dessay, Nadine Girod, Romain Stefani, Aurélia Nacher, Mathieu Moiret, Adrien Seyler, Frédérique Auteurs secondaires : UMR 228 Espace-Dev, Espace pour le développement ; Institut de Recherche pour le Développement (IRD) - Université de Perpignan Via Domitia (UPVD) - Université Nice Sophia Antipolis (UNS) ; Université Côte d'Azur (UCA) - Université Côte d'Azur (UCA) - Université d'Avignon et des Pays de Vaucluse (UAPV) - Université de la Réunion (UR) - Université de Montpellier (UM) - Université de Guyane (UG) - Université des Antilles (Pôle Martinique) ; Université des Antilles (UA) - Université des Antilles (UA) - Université des Antilles (Pôle Guadeloupe) ; Université des Antilles (UA) Expertise et spatialisation des connaissances en environnement (ESPACE) Unité d'Entomologie Médicale ; Institut Pasteur de la Guyane Medicine Department ; Ecosystemes Amazoniens et Pathologie Tropicale (EPat) ; Institut Pasteur de la Guyane - Institut National de la Santé et de la Recherche Médicale (INSERM) - Université de Guyane (UG) - Institut Pasteur de la Guyane - Institut National de la Santé et de la Recherche Médicale (INSERM) - Université de Guyane (UG) Centre d'Investigation Clinique Antilles-Guyane (CIC - Antilles Guyane) ; Université des Antilles et de la Guyane (UAG) - Institut National de la Santé et de la Recherche Médicale (INSERM) - CHU de Pointe-à-Pitre - Centre Hospitalier de Cayenne Andrée Rosemon - CHU de Fort de France Éditeur(s) : HAL CCSD MDPI Résumé : International audience Malaria remains one of the most common vector-borne diseases in the world and the definition of novel control strategies can benefit from the modeling of transmission processes. However, data-driven models are often difficult to build, as data are very often incomplete, heterogeneous in nature and in quality, and/or biased. In this context, a knowledge-based approach is proposed to build a robust and general landscape-based hazard index for malaria transmission that is tailored to the Amazonian region. A partial knowledge-based model of the risk of malaria transmission in the Amazonian region, based on landscape features and extracted from a systematic literature review, was used. Spatialization of the model was obtained by generating land use and land cover maps of the cross-border area between French Guiana and Brazil, followed by computing and combining landscape metrics to build a set of normalized landscape-based hazard indices. An empirical selection of the best index was performed by comparing the indices in terms of adequacy with the knowledge-based model, intelligibility and correlation with P. falciparum incidence rates. The selected index is easy to interpret and successfully represents the current knowledge about the role played by landscape patterns in malaria transmission within the study area. It was significantly associated with P. falciparum incidence rates, using the Pearson and Spearman correlation coefficients (up to 0.79 and 0.75, respectively; p-value < 0.001), and the linear regression coefficient of determination (reaching 0.63; p-values < 0.001). This study establishes a spatial knowledge-driven, landscape-based hazard malaria index using remote sensing that can be easily produced on a regular basis and might be useful for malaria prediction, surveillance, and control. Keywords: remote sensing; land use and land cover; landscape metric; knowledge-based hazard modeling; malaria; cross-border area between French Guiana and Brazil ISSN: 2072-4292 hal-01355255 https://hal.archives-ouvertes.fr/hal-01355255 https://hal.archives-ouvertes.fr/hal-01355255/document https://hal.archives-ouvertes.fr/hal-01355255/file/010066865.pdf IRD : fdi:010066865 | Partager Voir aussi malaria cross-border area between French Guiana and Brazil remote sensing land use and land cover landscape metric knowledge-based hazard modeling [STAT.AP] Statistics [stat]/Applications [stat.AP] [SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie [SHS.GEO] Humanities and Social Sciences/Geography |
Is Exercise-Induced Arterial Hypoxemia in Triathletes Dependent on Exercise Modality ? Auteur(s) : Galy, Olivier Boussana, Alain Hue, Olivier Le Gallais, Daniel Prefaut, Christian Auteurs secondaires : Adaptations au Climat Tropical, Exercice et Santé (ACTES) ; Université des Antilles et de la Guyane (UAG) Laboratoire de Physiologie des Interactions ; CHU Arnaud de Villeneuve Centre d'Optimisation de la Performance Motrice ; Université Montpellier 1 (UM1) Euromov (EuroMov) ; Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier) - Institut National de la Santé et de la Recherche Médicale (INSERM) - Université de Montpellier (UM) Interface Biopsychosociale des A.P.A. ; Université Montpellier 1 (UM1) Éditeur(s) : HAL CCSD Résumé : International audience To determine whether exercise modality affects arterial hypoxemia (EIAH) during training-intensity exercise, 13 triathletes performed 20 min of cycling (C) followed by 20 min of running (R): C-R, and two weeks later, 20 min of R followed by 20 min of C:R-C. Each trial was performed at an intensity slightly above the ventilatory threshold and close to the daily training intensity (75 % of VO2max). Ventilatory data were collected continuously using an automated breath-by-breath system. Partial pressure of oxygen in arterial blood (PaO2) was measured after each C and R segment and arterial oxyhemoglobin saturation (SpO2) was monitored continuously via pulse oximetry. The metabolic rate was similar across modalities and trials, i.e., C-R (53.8 +/- 3.8 vs. 51.1 +/- 5.3 ml.min(-1).kg(-1)) and R-C (52.2 +/- 4.5 vs. 53.2 +/- 4.6 ml.min(-1).kg (-1)). EIAH showed significantly greater severity for R compared to C irrespective of the order (p < 0.05 for both trials). R values of PaO2 (and SpO2) for C-R and R-C were 88.7 +/- 6.0 mm Hg (93.0 +/- 0.6 % SpO2) and 86.6 +/- 7.3 mm Hg (93.5 +/- 0.6 % SpO2) and C values were 93.7 +/- 8.4 mm Hg (95.4 +/- 0.4 % SpO2) and 91.4 +/- 5.4 mm Hg (94.8 +/- 0.3 % SpO2). R ventilatory data described a significantly different breathing pattern than C, with higher respiratory rate (35.9 b.min(-1) vs. 51.1 b.min(-1) for C-R, p < 0.01; and 50.0 b.min(-1) vs. 41.5 b.min(-1) for R-C, p < 0.01) and lower tidal volume (2636 ml vs. 2282 ml for C-R, p < 0.02 and 2272 ml vs. 2472 ml for R-C, p < 0.05). We concluded that EIAH was greater during running than cycling for a similar metabolic rate corresponding to training intensity and that EIAH could thus be considered dependent on exercise modality. Internation Journal of Sports Medicine hal-00720806 https://hal.univ-antilles.fr/hal-00720806 https://hal.univ-antilles.fr/hal-00720806/document https://hal.univ-antilles.fr/hal-00720806/file/sm290.pdf | Partager |
Continental growth seen through the sedimentary record Auteur(s) : Dhuime, Bruno Hawkesworth, Chris j. Delavault, Helene Cawood, Peter a. Auteurs secondaires : Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) University of Bristol University of St. Andrews Éditeur(s) : HAL CCSD Elsevier Résumé : International audience Sedimentary rocks and detrital minerals sample large areas of the continental crust, and they are increasingly seen as a reliable archive for its global evolution. This study presents two approaches to model the growth of the continental crust through the sedimentary archive. The first builds on the variations in U-Pb, Hf and O isotopes in global databases of detrital zircons. We show that uncertainty in the Hf isotope composition of the mantle reservoir from which new crust separated, in the 176Lu/177Hf ratio of that new crust, and in the contribution in the databases of zircons that experienced ancient Pb loss(es), adds some uncertainty to the individual Hf model ages, but not to the overall shape of the calculated continental growth curves. The second approach is based on the variation of Nd isotopes in 645 worldwide fine-grained continental sedimentary rocks with different deposition ages, which requires a correction of the bias induced by preferential erosion of younger rocks through an erosion parameter referred to as K. This dimensionless parameter relates the proportions of younger to older source rocks in the sediment, to the proportions of younger to older source rocks present in the crust from which the sediment was derived. We suggest that a Hadean/Archaean value of K = 1 (i.e., no preferential erosion), and that post-Archaean values of K = 4–6, may be reasonable for the global Earth system. Models built on the detrital zircon and the fine-grained sediment records independently suggest that at least 65% of the present volume of continental crust was established by 3 Ga. The continental crust has been generated continuously, but with a marked decrease in the growth rate at ~ 3 Ga. The period from > 4 Ga to ~ 3 Ga is characterised by relatively high net rates of continental growth (2.9–3.4 km3 yr− 1 on average), which are similar to the rates at which new crust is generated (and destroyed) at the present time. Net growth rates are much lower since 3 Ga (0.6–0.9 km3 yr− 1 on average), which can be attributed to higher rates of destruction of continental crust. The change in slope in the continental growth curve at ~ 3 Ga is taken to indicate a global change in the way bulk crust was generated and preserved, and this change has been linked to the onset of subduction-driven plate tectonics. At least 100% of the present volume of the continental crust has been destroyed and recycled back into the mantle since ~ 3 Ga, and this time marks a transition in the average composition of new continental crust. Continental crust generated before 3 Ga was on average mafic, dense, relatively thin (< 20 km) and therefore different from the calc-alkaline andesitic crust that dominates the continental record today. Continental crust that formed after 3 Ga gradually became more intermediate in composition, buoyant and thicker. The increase in crustal thickness is accompanied by increasing rates of crustal reworking and increasing input of sediment to the ocean. These changes may have been accommodated by a change in lithospheric strength at around 3 Ga, as it became strong enough to support high-relief crust. This time period therefore indicates when significant volumes of continental crust started to become emergent and were available for erosion and weathering, thus impacting on the composition of the atmosphere and the oceans. ISSN: 0037-0738 hal-01622696 https://hal.archives-ouvertes.fr/hal-01622696 DOI : 10.1016/j.sedgeo.2017.06.001 | Partager |
A detailed analysis of the productivity of solar home system in an Amazonian environment Auteur(s) : Linguet, L Hidair, I Auteurs secondaires : Université de Guyane Espace pour le Développement (UMR ESPACE-DEV) ; Institut de Recherche pour le Développement (IRD) - Université des Antilles et de la Guyane (UAG) - Université de la Réunion - Université de Montpellier (UM) Feder Guyane, Région Guyane Éditeur(s) : HAL CCSD Elsevier Résumé : International audience This paper discusses and analyses the productivity of solar home systems in isolated areas in French Guiana, a region characterized by specific human and environmental conditions.Its aim is a better understanding of the attitudes, expectations, and relationship of the users towards the solar home system. The data collected made it possible to make suggestions for adapting the photovoltaic systems to their environment by taking into account social, cultural, and geoclimatic specificities. Analysis of on-site productivity provides valuable information on energy profiles and types of use. Field surveys made it possible to associate users’ perception of the energy production equipment and their degree of satisfaction with operating efficiency and on-site maintenance. This aspect is essential for analyzing the actual rate of use of the energy that is theoretically available.Parallel to these surveys, the results of the study carried out on the performance of the solar home systems made it possible to learn the quantitative aspects of the energy produced and consumed as well as the qualitative aspects of the parameters that condition the performance of the photovoltaic systems.After keyboarding, the subjective, qualitative as well as the quantitative variables were processed using a statistical analysis program in order to determine the correlations between them and to prepare the final conclusions. ISSN: 1364-0321 hal-01304585 https://hal.archives-ouvertes.fr/hal-01304585 https://hal.archives-ouvertes.fr/hal-01304585/document https://hal.archives-ouvertes.fr/hal-01304585/file/article%20RSER%20Hal.pdf DOI : 10.1016/j.rser.2009.06.015 | Partager |