Impacts des mammifères allochtones sur quelques espèces autochtones de l’îlet Fajou (réserve naturelle du grand cul-de-sac marin, Guadeloupe), établis à l’issue d’une tentative d’éradication

In March 2001, simultaneously by trapping and chemical baits an attempt was done to eradicate the Javanese Mongoose (Herpestes javanicus), the Ship Rat (Rattus rattus) and the House Mouse (Mus domesticus) from Fajou Island (104 ha of mangrove on peat, 11 ha of dry vegetation on sandy soil), part of a natural reserve managed by the Guadeloupe National Park (French West Indies). A control in December 2001 and January 2002 revealed the failure of the Ship Rat eradication. A second eradication operation was undertaken in March 2002 in order to test hypotheses explaining this failure and put right some technical defects. Its result will not be available before 2003. However it allowed to conclude to the success of the Mongoose eradication by trapping alone but the potential success of the House Mouse eradication by trapping and poisoning in March 2001 could not yet be properly evaluated. The spatial distribution of trapping specimens of the target species showed that statistically they concentrate on the dry part of the island. The Mongoose eradication and the sharp decline of the Ship Rat population induced the disappearance of the destruction of Hawksbill Turtle (Eretmochelys imbricata) nests and the colonization of the dry part of the island by the Clapper Rail (Rallus longirostris), strictly located in the mangrove before. The abundance indices of the Clapper Rail and the terrestrial crab Cardisoma guanhumi increased. To be tested, the eventual relationships between these increases and the drop of the alien mammal populations require more data. Such operations combining research and management have to be planned in the long term with good logistical, technical and qualified human supports. All these conditions were gathered here because of the protected area status of the Fajou Island.L’éradication simultanée de la Petite Mangouste indienne (Herpestes javanicus auropunctatus), du Rat noir (Rattus rattus) et de la Souris domestique (Mus musculus) a été tentée en mars 2001 sur l’îlet Fajou (104 ha de mangrove sur tourbe, 11 ha de formation végétale xérophile sur sol sableux), partie d’une réserve naturelle gérée par le Parc National de la Guadeloupe (Antilles françaises). Elle a fait appel à l’utilisation successive du piégeage et de la lutte chimique. Un contrôle réalisé en décembre 2001 et janvier 2002 a démontré l’échec de l’éradication du Rat noir. Une seconde opération d’éradication a été conduite en mars 2002. Elle a permis de tester diverses hypothèses destinées à expliquer l’échec de l’élimination du Rat noir lors de la première tentative et de pallier certaines imperfections techniques. Le résultat de cette seconde tentative devra être établi en 2003. Elle a permis de conclure au succès de la tentative d’éradication de la Mangouste par le seul piégeage. L’éventuel succès de l’élimination de la Souris domestique par l’action cumulée du piégeage et de la lutte chimique dès mars 2001, ne sera contrôlé qu’en 2003. L’analyse de la répartition spatiale des captures des espèces-cibles a permis de démontrer qu’elles fréquentaient préférentiellement la partie de l’île couverte de végétation xérophile. L’élimination de la Mangouste et la forte réduction de l’effectif du Rat noir sont directement corrélées à la totale cessation des destructions de nids de la Tortue imbriquée (Eretmochelys imbricata) et à une apparente colonisation de la partie sèche de l’île par le Râle gris (Rallus longirostris), cantonné auparavant à la seule mangrove. Les indices d’abondance du Râle gris et du Crabe blanc (Cardisoma guanhumi) ont augmenté à Tissue de cette opération. Seul un suivi à long terme permettra de conforter ou d’invalider la présomption de relation de cause à effet entre l’augmentation de ces indices et l’élimination des populations allochtones. De pareilles opérations de recherche et de gestion imposent un travail sur le long terme ainsi que la mobilisation de moyens techniques importants et d’un personnel qualifié. Ces conditions ont été réunies lors de la présente opération grâce au statut d’aire protégée dont bénéficie l’îlet Fajou.Lorvelec Olivier, Delloue Xavier, Pascal Michel, Mège Simone. Impacts des mammifères allochtones sur quelques espèces autochtones de l’îlet Fajou (réserve naturelle du grand cul-de-sac marin, Guadeloupe), établis à l’issue d’une tentative d’éradication . In: Revue d'Écologie (La Terre et La Vie), tome 59, n°1-2, 2004. pp. 293-307

Habitat-related variation in the plasticity of a UV-sensitive photoreceptor over a small spatial scale in the palmate newt

Plastic phenotypes are expected to be favoured in heterogeneous environments compared with stable environments. Sensory systems are interesting to test this theory because they are costly to produce and support, and strong fitness costs are expected if they are not tuned to the local environment. Consistently, the visual system of several species changes with the conditions experienced during early development. However, there is little information on whether the amplitude of the change, that is the reaction norm, differs between visual environments. Given the rapid change of many ecosystems, especially eutrophication for aquatic habitats, it is crucial to determine down to which spatial scale, change in the reaction norm occurs. We addressed this issue by quantifying the between-habitat variation in the expression of a UV-sensitive opsin in a newt. In western France, this species breeds in ponds of small forest patches, where water filters out UV, and in agricultural ponds where UV transmission is variable. We raised larvae from both habitats with or without exposure to UV. Opsin expression was reduced in larvae from agricultural habitats when raised without UV, whereas it was low in larvae from forest ponds under all lighting conditions. Thus, the variation in the reaction norm of opsin expression was lower in stable filtering environments and higher in heterogeneous environments. Its variation occurred between habitats across a small spatial scale. We discuss the hypotheses for this pattern and for the maintenance of residual opsin expression in forest populations

The UV multi-object slit-spectrograph FIREBall-2 simulator

International audienceno abstrac

Dataset_expression of_newt_opsin

Relative expression of opsins SWS1 and LWS in larvae of Lissotriton helveticus from 2 maternal habitats (forest, agricultural). Two ponds (populations) have been sampled per habitat. Larvae have been exposed daily to UV for 15 min (UV+), or they have not been exposed (UV-)

Image1_Tectonic and hydrothermal activity at the Yellow Lake fissure in response to the 2004 Dallol dyke intrusion event in Afar.pdf

The Danakil depression in Ethiopia, at the southern end of the Red Sea, has been the place of volcanic crises in 2004–10, with emplacement of at least 15 dykes. One of them, non-emergent, occurred in dry lake Asale next to Black Mountain and south of Mount Dallol during fall 2004. We report on the opening of a 4.5 km-long fissure in the ground at the same time the Black Mountain dyke was intruding the crust 2 km westward and parallel to it. The fissure, located north and south of Yellow Lake (Gaet’ale) and trending NNW-SSE, is still hydrothermally active. First, we describe the remarkable diversity of morphologic expressions of the fissure, made possible by development in an evaporite sequence. Satellite image monitoring reveals that its formation is coeval with the latest intrusion stage of the Black Mountain dyke. Hydrothermal activity in the fissure area is, however older than ∼60 years. It is suggested that hydrothermal activity is primarily a side effect of the igneous processes, probably sill intrusion, that resulted in the uplift of Mount Dallol area, in a ∼400 m thick, fluid-saturated evaporite pile. We suggest that, in 2004, emplacement of the Black Mountain dyke caused dilation within the evaporite pile overlying it, where extension was also facilitated by pressured pore fluids. This study documents the delicate intermingling of magmatic, tectonic, hydrothermal, and geomorphologic processes in evaporitic environments at the transition between continental rifting and oceanic spreading.</p

Video1_Tectonic and hydrothermal activity at the Yellow Lake fissure in response to the 2004 Dallol dyke intrusion event in Afar.MP4

The Danakil depression in Ethiopia, at the southern end of the Red Sea, has been the place of volcanic crises in 2004–10, with emplacement of at least 15 dykes. One of them, non-emergent, occurred in dry lake Asale next to Black Mountain and south of Mount Dallol during fall 2004. We report on the opening of a 4.5 km-long fissure in the ground at the same time the Black Mountain dyke was intruding the crust 2 km westward and parallel to it. The fissure, located north and south of Yellow Lake (Gaet’ale) and trending NNW-SSE, is still hydrothermally active. First, we describe the remarkable diversity of morphologic expressions of the fissure, made possible by development in an evaporite sequence. Satellite image monitoring reveals that its formation is coeval with the latest intrusion stage of the Black Mountain dyke. Hydrothermal activity in the fissure area is, however older than ∼60 years. It is suggested that hydrothermal activity is primarily a side effect of the igneous processes, probably sill intrusion, that resulted in the uplift of Mount Dallol area, in a ∼400 m thick, fluid-saturated evaporite pile. We suggest that, in 2004, emplacement of the Black Mountain dyke caused dilation within the evaporite pile overlying it, where extension was also facilitated by pressured pore fluids. This study documents the delicate intermingling of magmatic, tectonic, hydrothermal, and geomorphologic processes in evaporitic environments at the transition between continental rifting and oceanic spreading.</p

Table1_Tectonic and hydrothermal activity at the Yellow Lake fissure in response to the 2004 Dallol dyke intrusion event in Afar.pdf

The Danakil depression in Ethiopia, at the southern end of the Red Sea, has been the place of volcanic crises in 2004–10, with emplacement of at least 15 dykes. One of them, non-emergent, occurred in dry lake Asale next to Black Mountain and south of Mount Dallol during fall 2004. We report on the opening of a 4.5 km-long fissure in the ground at the same time the Black Mountain dyke was intruding the crust 2 km westward and parallel to it. The fissure, located north and south of Yellow Lake (Gaet’ale) and trending NNW-SSE, is still hydrothermally active. First, we describe the remarkable diversity of morphologic expressions of the fissure, made possible by development in an evaporite sequence. Satellite image monitoring reveals that its formation is coeval with the latest intrusion stage of the Black Mountain dyke. Hydrothermal activity in the fissure area is, however older than ∼60 years. It is suggested that hydrothermal activity is primarily a side effect of the igneous processes, probably sill intrusion, that resulted in the uplift of Mount Dallol area, in a ∼400 m thick, fluid-saturated evaporite pile. We suggest that, in 2004, emplacement of the Black Mountain dyke caused dilation within the evaporite pile overlying it, where extension was also facilitated by pressured pore fluids. This study documents the delicate intermingling of magmatic, tectonic, hydrothermal, and geomorphologic processes in evaporitic environments at the transition between continental rifting and oceanic spreading.</p

Locally recurrent prostate cancer after initial radiation therapy: early salvage high-intensity focused ultrasound improves oncologic outcomes.

PURPOSE: To evaluate pre-operative prognostic risk factors to predict oncologic outcome of Salvage High-Intensity Focused Ultrasound (S-HIFU) for radiorecurrent prostate cancer (PCa). METHODS AND MATERIALS: A total of 290 men with biopsy-confirmed locally radiorecurrent PCa, underwent S-HIFU. D'Amico risk group before external beam radiotherapy (EBRT), Prostate Specific Antigen (PSA), estimated Gleason score prior HIFU and post HIFU biopsies were analyzed for predictive utility of local cancer control, cancer-specific, metastasis free, and progression free survival rates (PFSR). RESULTS: Local cancer control with negative biopsy results was obtained in 81% of the 208 patients who underwent post-S-HIFU biopsies. Median PSA nadir was 0.14 ng/ml and 127 patients did not require androgen deprivation therapy (ADT). The mean follow up was 48 months for cancer-specific survival rates. The cancer-specific and metastasis-free survival rates at 7 years were 80% and 79.6% respectively. The PFSR was significantly influenced by: the pre-HIFU PSA level (hazard ratio (HR): 1.09, 95% CI 1.04-1.13), a Gleason score ≥8 versus ≤6 (HR: 1.17, 95% CI 1.03-1.3), and a previous ADT (HR: 1.28, 95% CI 1.09-1.46). The rates of recto-urethral fistula (0.4%) and grade II/III incontinence (19.5%) indicate significant reduction in serious side effects with use of dedicated post-radiation acoustic parameters compared with standard parameters. CONCLUSION: S-HIFU is an effective curative option for radiorecurrent PCa with acceptable morbidity for localized radiorecurrent PCa, but should be initiated early following EBRT failure. Use of prognostic risk factors can optimize patient selection