Pourquoi Pas Research Articles

Emmery Blin (1863–1930). Un aliéniste d’enfants, pionnier de la psychologie expérimentale et membre de la Société Médico-Psychologique (1889)

Emmery Eugène Blin (1863–1930) was born in Paris where he studied medicine at the Paris Medical School. After serving as an extern in hospitals (1887) and then as an intern in the asylums in the former department of Seine (1888), he won first prize in the competitive examination for the administration of Parisian psychiatric hospitals in 1890. That same year, he successfully defended his doctoral dissertation in medicine. From December 1890 to September 1891, he was assistant physician at the Evreux asylum before being promoted to assistant physician at the Vaucluse asylum, an establishment created in 1876, and where he would remain until his retirement in 1920. An alumnus of the École des Hautes Études and a member of learned societies (Société médico-psychologique 1889; Société de médecine 1891; Société clinique de médecine mentale 1909), Blin was the first, prior to the Binet and Simon test, to use a questionnaire to differentiate between morons, imbeciles and profound idiots. Together with Théodore Simon he designed a campylogram (1900), and always attributed great importance to the use of the test method in child clinical practice. Following in the footsteps of Itard, Seguin, Bourneville and his colleagues, Blin thus contributed to improving the pedagogical education of retarded children and can be considered the leader of the Perray-Vaucluse school of child psychiatry (Théodore Simon, Maurice Brissot, André Beley). In addition to his medical activities, Blin was introduced to sculpture by Paul Richer (1849–1933) and became a student of Denys Puech (1854–1942); he was a member of the Society of French Artists in the sculpture section (1903). An experienced navigator, he was a member of the crew of one of Jean-Baptiste Charcot's (1867–1936) ships that were christened the “Pourquoi pas?”. The same year that Th. Simon succeeded him at the Vaucluse asylum (1920), Blin was convicted of trafficking in morphine. He died in Paris on March 23, 1930.

First zoeal stage of the Indian Ocean hydrothermal vent crab, Austinograea rodriguezensis Tsuchida & Hashimoto, 2002 (Decapoda: Brachyura: Bythograeidae).

First stage zoeas of the vent crab Austinograea rodriguezensis Tsuchida & Hashimoto, 2002 (Decapoda, Brachyura, Bythograeidae) were collected by a remotely operated vehicle from the Kairei Hydrothermal Vent, Central Indian Ridge, in January 2016 during the INDEX2016 cruise of the French registered RV Pourquoi Pas? The zoeal appendages are illustrated using confocal laser scanning microscopy and described. A comparison between first stage zoeal morphology of Gandalfus yunohana (Takeda, Hashimoto & Ohta, 2000) and A. rodriguezensis is made and, although remarkably similar, they can be distinguished by dorsal pleonal spinulation. Tdhe number of possible zoeal stages of A. rodriguezensis is discussed and considered to be four. Several deep-water brachyuran zoea 1 have been described with distinct elongated dorsal carapace and pleonal spinulation, including A. rodriguezensis, G. yunohana, Calocarcinus africanus Calman, 1909, Dorhynchus thomsoni Thomson, 1873. These are compared with the zoeas of three species of Geryoninae Colosi, 1924 for which the larval phases are described. These geryonine crabs are also deep-water species, but their zoeas are only described with rostral, dorsal and lateral carapace spines and are without the elongated dorsal spinulation of the carapace and pleomeres. This is attributed to the fact these geryonines have an extensive distribution range compared to those of A. rodriguezensis, G. yunohana, C. africanus and D. thomsoni, which are restricted to discrete habitats. The elongated dorsal spinulation of the carapace and pleomeres of these latter four species is attributed to the fact that the length of these spines increases the effective size of these without extra cost of growth and help the dispersal of the zoeal stages. Videos of A. rodriguezensis female behaviour with respect to aeration of eggs and the subsequent hatching near vent plumes are provided as supplementary information.

Seasonal Flow Types of Glaciers in Sermilik Fjord, Greenland, Over 2016–2021

AbstractGreenland glaciers have three primary seasonal ice flow patterns, or “types”: terminus‐driven, runoff‐driven, and runoff‐adapting. To date, glacier types have been identified by analyzing flow at a single location near the terminus; information at all other locations is discarded. Here, we use principal component (PC)/empirical orthogonal function (EOF) analysis to decompose multi‐year time series of glacier speed, combined from three satellite‐derived products at four glaciers feeding Sermilik Fjord, Greenland. This improves on single‐point methods by yielding spatial patterns (EOFs), which ensure the result reflects data at all locations on the glacier, and associated temporal patterns (PCs), which allow identification of glacier type. We find that the leading EOF is uniformly signed over the entire glacier domain, that this mode explains the majority of the variance in speed, and therefore that glacier type can be inferred from the leading PC. We find that Helheim Glacier was terminus‐driven, Fenris Glacier and Midgard Glacier were runoff‐adapting, and Pourquoi Pas Glacier was runoff‐driven over 2016–2021. Our classification agrees with previous work for Helheim and Midgard Glaciers, but differs at the other two. At all but Fenris Glacier, the leading PC correlates significantly with the speed pattern observed at the single point used in previous analyses. Thus, Fenris Glacier has more complex flow patterns than single‐point analysis can capture, and wider spatial analysis techniques such as EOF/PC are required. We suggest that, due to its low computational cost and inclusion in standard analysis packages, EOF/PC analysis should be used for assessing glacier type.

The Commencement of Jean-Luc Nancy

Abstract Jean-Luc Nancy was concerned with commencement at several levels, of several kinds, in several senses, because he could speak of commencement with affirmation, which means with audacity. From the hospital in July 2021 he completed his last essay, which was intended to commence the project of “the other beginning of philosophy” envisaged by him, Shaj Mohan, and Divya Dwivedi, and he titled it “The End of Philosophy and the Task of Thinking.” In and through it are gathered all of Nancy’s critical reflections on destiny, on the antisemitic components of the Heideggerian history of being, on the ends of philosophy that we must reckon with, on origins and archaeophilia, on the an-archique essence of philosophy and democracy—and this means for us, on another sense of commencement than arche, which could allow us to prepare another beginning of philosophy than the Heideggerian one, and to respond to Nancy’s wager “Pourquoi pas en finir?” Nancy has not left us; rather, we are only now commencing with Nancy.

Impact of dust addition on the metabolism of Mediterranean plankton communities and carbon export under present and future conditions of pH and temperature

Abstract. Although atmospheric dust fluxes from arid as well as human-impacted areas represent a significant source of nutrients to surface waters of the Mediterranean Sea, studies focusing on the evolution of the metabolic balance of the plankton community following a dust deposition event are scarce, and none were conducted in the context of projected future levels of temperature and pH. Moreover, most of the experiments took place in coastal areas. In the framework of the PEACETIME project, three dust-addition perturbation experiments were conducted in 300 L tanks filled with surface seawater collected in the Tyrrhenian Sea (TYR), Ionian Sea (ION) and Algerian basin (FAST) on board the R/V Pourquoi Pas? in late spring 2017. For each experiment, six tanks were used to follow the evolution of chemical and biological stocks, biological activity and particle export. The impacts of a dust deposition event simulated at their surface were followed under present environmental conditions and under a realistic climate change scenario for 2100 (ca. +3 ∘C and −0.3 pH units). The tested waters were all typical of stratified oligotrophic conditions encountered in the open Mediterranean Sea at this period of the year, with low rates of primary production and a metabolic balance towards net heterotrophy. The release of nutrients after dust seeding had very contrasting impacts on the metabolism of the communities, depending on the station investigated. At TYR, the release of new nutrients was followed by a negative impact on both particulate and dissolved 14C-based production rates, while heterotrophic bacterial production strongly increased, driving the community to an even more heterotrophic state. At ION and FAST, the efficiency of organic matter export due to mineral/organic aggregation processes was lower than at TYR and likely related to a lower quantity/age of dissolved organic matter present at the time of the seeding and a smaller production of DOM following dust addition. This was also reflected by lower initial concentrations in transparent exopolymer particles (TEPs) and a lower increase in TEP concentrations following the dust addition, as compared to TYR. At ION and FAST, both the autotrophic and heterotrophic community benefited from dust addition, with a stronger relative increase in autotrophic processes observed at FAST. Our study showed that the potential positive impact of dust deposition on primary production depends on the initial composition and metabolic state of the investigated community. This impact is constrained by the quantity of nutrients added in order to sustain both the fast response of heterotrophic prokaryotes and the delayed one of primary producers. Finally, under future environmental conditions, heterotrophic metabolism was overall more impacted than primary production, with the consequence that all integrated net community production rates decreased with no detectable impact on carbon export, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.

Regional chronostratigraphy in the eastern Lesser Antilles quaternary fore-arc and accretionary wedge sediments: Relative paleointensity, oxygen isotopes and reversals

Paleomagnetism is a powerful tool for establishing an almost continuous chronostratigraphy for an entire region. When combined with other dating methods, absolute or relative, it can be used to develop a regional reference chronostratigraphic framework. During the summer of 2016, several piston cores were collected along the Atlantic side of the Lesser Antilles onboard the R/V Pourquoi pas? as part of the CASEIS Expedition. Core CAS16-24PC was devoted to chronostratigraphic analysis and allowed development of a quasi-continuous Quaternary record. In this study, after identifying and removing rapidly deposited layers such as turbidites and tephra layers, we reconstructed the relative paleointensity (RPI) variations by normalizing the natural remanent magnetization with the laboratory induced anhysteretic remanent magnetization. An age model was developed by comparing our RPI record with the PISO-1500 stack and paleomagnetic axial dipole moment model for the past 2 Myr (PADM-2M) and the planktic oxygen isotopic record (δ18O) for core CAS16-24PC with the LR04 benthic stack. By combining the δ18O stratigraphy with paleomagnetic analyses, we established an age model covering the Brunhes/Matuyama boundary and Jaramillo Subchron back to ~1.15 Ma with a mean sedimentation rate of 1.7 cm/kyr. This age model complements the paleomagnetic data from IODP campaigns and volcanic records, and offers almost complete inclination, declination and RPI records as a local reference.

Characterizing the variability of natural gas hydrate composition from a selected site of the Western Black Sea, off Romania

Natural Gas Hydrates (NGH) collected during the Ghass cruise 2015 in the Western Black Sea onboard the R/V Pourquoi pas? are characterized by a suite of techniques. Gas Chromatography and Raman spectroscopy are used for the identification of the nature of the gas source, the hydrate structure and spatial variability of cage occupancies. The nature and source of hydrate forming gases primarily reveal a high methane content (99.6 mol%) and small amount of nitrogen (>0.29 mol%) and CO2 (0.056 mol%). Isotopic analyses from the hydrate-bound methane and recently published results from Pape et al. (2020) clearly indicate a microbial source of gas supplying the hydrate deposit generated by the reduction of carbon. For the first time, Raman imaging spectroscopy was applied on NGH recovered in the Western Black Sea. The results show a heterogeneous distribution of the encapsulated guest molecules (CH4, N2 and H2S), which is associated with a spatial variability of the guest-gas composition at the micron-scale. Some portions of the 2D-Raman images clearly exhibit a relative N2-enrichment (with a concentration exceeding 6 mol% N2 at some positions), while H2S shows a rather minor contribution on all the spectral maps investigated. A correlation is then established between the composition of the gas in the NGH and its impact on the CH4 cage occupancy, with a ratio of θLC/θSC (large cage/small cage) between ~ 0.5 and 1.26 depending on the positions analyzed. The departure from the expected ratio in pure methane hydrate is attributed to the preferential encasement of N2 in the large cage of the NGH structure. In addition, the occurrence of carotenoids identified in sediment-rich zones show a minor impact on the CH4 cage occupancies. The results are discussed within the context of natural gas resource estimates in NGH to emphasize how the measured cage occupancies may impact the volumetric conversion factor commonly used with other geologic parameters to determine the resource endowment and global volume of methane. The small-scale heterogeneities revealed by the 2D-Raman images point out the importance to better understand stages of hydrates formation in methane-rich seafloor environment.

Women in Medicine: Dr. Theresa Tam

Canada’s Chief Public Health Officer, Dr. Theresa Tam (BMBS (UK), FRCPC) attended medical school in the United Kingdom before immigrating to Canada where she trained in pediatrics and specialized in infectious disease. She has maintained a ‘pourquoi pas’ attitude throughout her career that has helped her realize her vocation in public health, gain experience in the healthcare field—both around the globe and on Canadian soil—and advance into prominent leadership positions. Today, as Canada’s Chief Public Health Officer, known colloquially as Canada’s Top Doctor, Dr. Tam has been thrust into the spotlight as a result of the COVID-19 pandemic. This article outlines her exciting career trajectory and explores the challenges she faces while informing Canadians of guidelines for staying healthy during the pandemic.

Inputs and processes affecting the distribution of particulate iron in the North Atlantic along the GEOVIDE (GEOTRACES GA01) section

Abstract. The aim of the GEOVIDE cruise (May–June 2014, R/V Pourquoi Pas?) was to provide a better understanding of trace metal biogeochemical cycles in the North Atlantic Ocean. As marine particles play a key role in the global biogeochemical cycle of trace elements in the ocean, we discuss the distribution of particulate iron (PFe), in relation to the distribution of particulate aluminium (PAl), manganese (PMn), and phosphorus (PP). Overall, 32 full vertical profiles were collected for trace metal analyses, representing more than 500 samples. This resolution provides a solid basis for assessing concentration distributions, elemental ratios, size fractionation, and adsorptive scavenging processes in key areas of the thermohaline overturning circulation. Total particulate iron concentrations ranged from as low as 9 pmol L−1 in surface waters of the Labrador Sea to 304 nmol L−1 near the Iberian margin, while median PFe concentrations of 1.15 nmol L−1 were measured over the sub-euphotic ocean interior. Within the Iberian Abyssal Plain, the ratio of PFe to PAl was identical to the continental crust molar ratio (0.21 mol mol−1), indicating the important influence of crustal particles in the water column. Overall, the lithogenic component explained more than 87% of PFe variance along the section. Within the Irminger and Labrador basins, the formation of biogenic particles led to an increase in the PFe∕PAl ratio (up to 0.64 mol mol−1) compared to the continental crust ratio. Continental margins induce high concentrations of particulate trace elements within the surrounding water masses (up to 10 nmol L−1 of PFe). For example, horizontal advection of PFe was visible more than 250 km away from the Iberian margin. Additionally, several benthic nepheloid layers were observed more than 200 m above the seafloor along the transect, especially in the Icelandic, Irminger, and Labrador basins, suspending particles with high PFe content of up to 89 nmol L−1.

Forced to change-for good.

“Can't stop loving you …” My 3-year-old son was singing along with Phil Collins from his car seat. We were on our commute, spending a few hours of quality time in Dutch rush-hour traffic. But I was not in the mood to sing along. My manager at the biotech company where I had been working for a bit more than a year had just told me that, in spite of my excellent performance, he did not foresee giving me more responsibilities in the near future. I was working part time so that I could spend more time with my young children, and he believed the career growth I sought required a full-time employee. The message hit me hard. But it precipitated a change that, in the end, taught me the power of embracing opportunities, no matter where they come from. ![Figure][1] ILLUSTRATION: ROBERT NEUBECKER My manager's decision planted a seed of self-doubt. Was he right? Was I asking for too much? But I reminded myself that I had already proved I could be an effective scientist on a part-time schedule. During my 7 years as a university researcher working part time—a common choice among working mothers in the Netherlands—my career had flourished. With rigorous time management and organization, I got at least as much good work done in 4 days a week as others did on full-time schedules. When I left my university post for the biotech company, spurred by the desire for my work to reach patients, I expected that I would be able to grow professionally and advance my career there. I had the impression that the company valued performance and ambition. But now I was being told that I should be happy in my current role as a troubleshooter, rather than the project leader I aspired to be. A friend suggested that I reach out to senior managers about opportunities in other departments. At first, I resolutely rejected that idea. Didn't he understand? I wanted to work on antibodies and nothing but antibodies! That was what I knew, where I felt I could add the most value. And yet, I did not want to leave this cool company just because of one unsupportive manager. With little expectation that it would lead anywhere, I approached the three senior managers. One did not respond. One had nothing to offer. The third invited me to chat. He patiently listened to my story, asked what I was looking for, and then—in the blink of an eye—told me that I was welcome to join him in building a vaccine research unit. I stuttered that I knew nothing about vaccines. He waved nonchalantly and said, “You will learn. You are smart and willing to work hard. You will make it.” The reassurance was exactly what I had been looking for, but I was still shaken by my manager's lack of confidence in me. Could I really handle a high-responsibility role in a completely new field? A few sleepless nights later, I decided that taking a chance on the unknown was better than staying in a position that made me miserable. The worst thing that could happen was that I would fail. But I already felt like a failure, so why not try it? I soon discovered a new passion. My career path within the company opened up. I took on more responsibilities, developed new skills, expanded my scientific horizons, worked with great people, and led fantastic projects—all because of a change that had felt forced on me. It had pushed me further than I was willing to go, further than I thought I could cope with, and taught me that when I step out of my comfort zone, I find my most creative, productive self. More than 10 years later, antibodies—my scientific “first love”—crossed my path again in the form of an exciting, challenging position that demanded a major life change, complicated by my recent divorce. I would have to leave my home and community, start again in another country, and find a way to co-parent across borders. After many discussions, I asked my son whether he would go abroad with me. Without lifting his eyes from his Minecraft game, he responded, “ Pourquoi pas ?” I couldn't have said it better myself. [1]: pending:yes

Active fault system across the oceanic lithosphere of the Mozambique Channel: Implications for the Nubia–Somalia southern plate boundary

Seismic reflection and multibeam echosounder data were acquired in the Mozambique Channel in 2014 and 2015 during the PTOLEMEE, PAMELA-MOZ02 and -MOZ04 marine surveys aboard the RV Atalante and Pourquoi Pas? These data revealed that an active fault system is deforming the oceanic lithosphere of the Mozambique Basin which has developed during Jurassic-Cretaceous times. The correlation between the fault system and the arrangement of earthquake epicenters suggests that this tectonically active zone directly connects northward with the southern part of the eastern branch of the East African Rift System which corresponds to the seismically active graben system bounding the northern part of the Davie ridge. The fault zone extends southwestward of the Mozambique Ridge along the same trend as the Agulhas-Falkland transform fault zone. The general organization of the fault zone shows the characteristics of an extensional system north of the Mozambique Channel (north of the Europa Island) and a right-lateral transtensional system with coeval normal faults and strike-slip faults south-west of Europa. This tectonic activity is associated with volcanic activity since at least Late Miocene times. Our findings emphasize that the eastern branch of East African Rift System is extending largely toward the south, not only in continental domains but also through the oceanic lithosphere of the Mozambique basin. This fault zone is participating to the complex plate boundary between the main African continent (Nubia Plate) and Madagascar (Somalia Plate).

Sulfate-dependent anaerobic oxidation of methane at a highly dynamic bubbling site in the Eastern Sea of Marmara (Çinarcik Basin)

During the MARSITECruise expedition in November 2014 on board the RV Pourquoi Pas?, multidisciplinary sampling was carried out with the ROV Victor 6000 in order to investigate biogeochemical processes taking place at cold seep environments in the Sea of Marmara. Pore water, bottom water, sediment and authigenic carbonate samples were collected from two short push cores (MRS-DV5-PC04 − 8cm, MRS-DV5-PC01 − 12.5cm) at an active methane bubbling site in the southeastern part of the Çinarcik Basin. Sulfate sulfur and oxygen isotope data as well as sulfide isotope data indicate that sulfate-dependent anaerobic oxidation of methane is the dominant process in the sediments. This is confirmed by archaeal lipids diagnostic for anaerobic methane oxidizers detected with strong 13C-depletions. The available data even allows to distinguish the dominant AOM assemblages. Specific lipid patterns are consistent with a dominance of ANME-2 archaea within the microbial community. Abundant authigenic carbonates (mostly aragonite), found at all depths, show a narrow range in δ13C values between −27.69‰ and −33.40‰. The carbon isotopic composition of the dissolved inorganic carbon as well as strontium and calcium isotopes confirm that the current reaction zone (sulfate-methane transition zone) starts at the bottom of the core. All shallower carbonates are witnesses of paleo seepage activity. U-Th dating of four pure aragonite samples show the short time span that is preserved in core MRS-DV5-PC01 (235 ± 60yr B.P.). Two major earthquakes of 1766 CE and 1754 CE in the Çinarcik Basin might potentially have triggered the increased seepage of methane at this location.

Thermodynamic modeling of hydrothermal plumes forming processes in a submarine discharge zone

The main methods are considered and results of the modeling of the geochemical processes in submarine hydrothermal solutions of mid-ocean ridges discharge zones are analyzed. Initial materials for modeling were received at several sea expeditions, including operations at the Russian-French expedition SERPENTINE on RV «Pourquoi Pas?» (2007). For carrying out a computer thermodynamic modeling, hydro-geochemical and physicochemical models of a zone of hydrothermal discharge are created. Verification of model is carried out on the change of concentration of manganese in a hydrothermal plume. The prevailing forms of manganese migration in a plume are Mn 2+ , MnCl + , MnCl 2 . In a plume’s geochemical structure two zones are allocated: 1) high temperatures (350-100 °C), with the prevalence of the chloride complexes - buoyant plume; 2) low temperatures (100-2 °C), with the domination of a transfer in a form of free bivalent ion - lateral plume. The sulphate complex is observed in insignificant quantities (1,5 %) in a lateral plume, hydroxide - is stable at temperatures 325-125 °C and can be observed only in the buoyant plume. The results of the modeling almost completely correspond to the natural observations. A verification of the thermodynamic model testifies to her working capacity and allows to pass to the following stage of researches - to studying the geochemical dispersion nature of the main ore components in hydrothermal solutions - Fe, Cu, Zn, etc.

Experimental study of bubble sweep-down in wave and current circulating tank: Part I—Experimental set-up and observed phenomena

Bubble sweep-down is a significant issue for the oceanographic vessels, which affect the acoustic surveys. Experimental trials, carried out in the Ifremer wave and current circulating tank on a 1/30 model of the Pourquoi pas?, are presented. The results demonstrate that this kind of experimental facility is well suited to study the phenomenon of bubble sweep-down encountered around the bow of a ship under specific conditions. From these results, two kinds of bubble clouds formation have been observed and analysed: bubble clouds generated by vortex shedding and breaking waves. The vortex shedding bubble clouds appear randomly in all the configurations tested, even without waves or motions. This phenomenon is due to the interaction between the turbulent flow and the specific bow shape of the Pourquoi pas?. On the other hand, the breaking wave clouds appear in the presence of relative motions between the free surface and the bow ship and more significantly under wave sollicitations. A complementary paper presents a parametric study carried out to quantify the influence of the test conditions.

Bubble sweep-down occurrence characterization on Research Vessels

Bubble sweep-down on oceanographic vessels generates acoustic perturbations. We propose in this work to characterize the sub-surface bubbles occurrence conditions from acoustic data analysis acquired during surveys in relatively shallow water with the IFREMER research vessels Thalassa and Pourquoi Pas?. The methodology of data analysis used in this work allows us to characterize the sailing conditions influence on bubble sweep-down occurrence. The correlation between sailing conditions and acoustic perturbations tends to demonstrate that the presence of bubbles under the hull is clearly related to the wind speed and natural aeration, and that surface bubbles are advected differently in the water column by the two vessels.

Jean-Baptiste Charcot in Rio de Janeiro: glamorous trip and celebrity in 1908.

The authors review the visit of Commander Charcot and the crew of his ship, the "Pourquoi Pas?", to Rio de Janeiro, Brazil, in 1908, where he stayed for eight days, while en-route as part of the second French expedition to the Antarctic. It was a glamorous stay as Commander Charcot was treated as a true star and international celebrity, befitting his position.

Gas hydrate distributions in sediments of pockmarks from the Nigerian margin – Results and interpretation from shallow drilling

A joint research expedition between the French IFREMER and the German MARUM was conducted in 2011 using the R/V ‘Pourquoi pas?’ to study gas hydrate distributions in a pockmark field (1141–1199 m below sea surface) at the continental margin of Nigeria. The seafloor drill rig MeBo of MARUM was used to recover sediments as deep as 56.74 m below seafloor. The presence of gas hydrates in specific core sections was deduced from temperature anomalies recorded during continuous records of infrared thermal scanning and anomalies in pore water chloride concentrations. In situ sediment temperature measurements showed elevated geothermal gradients of up to 258 °C/km in the center of the so-called pockmark A which is up to 4.6 times higher than that in the background sediment (72 °C/km). The gas hydrate distribution and thermal regime in the pockmark are largely controlled by the intensity, periodicity and direction of fluid flow. The joint interaction between fluid flow, gas hydrate formation and dissolution, and the thermal regime governs pockmark formation and evolution on the Nigerian continental margin.

Jean-Baptiste Charcot, the French Antarctic expedition and scurvy.

During the second expedition to the South Pole, Commander Jean-Baptiste Charcot and some members of the crew of "Pourquoi Pas?" developed symptoms suggestive of scurvy. The clinical picture was totally reversed after dietary changes.

Jean-Baptiste Charcot and Brazil.

Jean-Baptiste Charcot, a neurologist from the famous Salpêtrière school and a renowned maritime explorer, visited Brazil twice. The first visit was in 1903, when the first French Antarctic expedition, traveling aboard the ship Français, made a very short stopover in Recife, in the state of Pernambuco. The second took place in 1908, during the famous voyage of the Pourquoi Pas? to the Antarctic, when Charcot and his crew stayed in the city of Rio de Janeiro for eight days.

Distribution and temporal variation of mega‐fauna at the Regab pockmark (Northern Congo Fan), based on a comparison of videomosaics and geographic information systems analyses

AbstractThe Regab pockmark is a large cold seep area located 10 km north of the Congo deep sea channel at about 3160 m water depth. The associated ecosystem hosts abundant fauna, dominated by chemosynthetic species such as the mussel Bathymodiolus aff. boomerang, vestimentiferan tubeworm Escarpia southwardae, and vesicomyid clams Laubiericoncha chuni and Christineconcha regab. The pockmark was visited during the West African Cold Seeps (WACS) cruise with RV Pourquoi Pas? in February 2011, and a 14,000‐m2 high‐resolution videomosaic was constructed to map the most populated area and to describe the distribution of the dominant megafauna (mussels, tubeworms and clams). The results are compared with previous published works, which also included a videomosaic in the same area of the pockmark, based on images of the BIOZAIRE cruise in 2001. The 10‐year variation of the faunal distribution is described and reveals that the visible abundance and distribution of the dominant megafaunal populations at Regab have not changed significantly, suggesting that the overall methane and sulfide fluxes that reach the faunal communities have been stable. Nevertheless, small and localized distribution changes in the clam community indicate that it is exposed to more transient fluxes than the other communities. Observations suggest that the main megafaunal aggregations at Regab are distributed around focused zones of high flux of methane‐enriched fluids likely related to distinct smaller pockmark structures that compose the larger Regab pockmark. Although most results are consistent with the existing successional models for seep communities, some observations in the distribution of the Regab mussel population do not entirely fit into these models. This is likely due to the high heterogeneity of this site formed by the coalescence of several pockmarks. We hypothesize that the mussel distribution at Regab could also be controlled by the occurrence of zones of both intense methane fluxes and reduced efficiency of the anaerobic oxidation of methane possibly limiting tubeworm colonization.