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Assessment of zooarchaeological data for the principal livestock (i.e., cattle, sheep, goats and pigs) reveals regional and cultural variability in how animals were manipulated, marketed, bred, and utilized over the course of antiquity. This paper focuses upon those developments, as reconstructed through zooarchaeological frequency and morphometric data for the period from c. 1000 BCE to c. 700 CE. Regionally, North Africa encompasses a vast territory, from Egypt, in the East, to Mauretania, in the West. Ecologically, there are variations within each of these zones. Culturally, moreover, these regions witnessed the introduction and influence of different social and economic agents and factors over the timeframe under investigation. This paper examines patterns in these components in a broad synthetic manner, using zooarchaeological data across the entire expanse of Roman North Africa—from Egypt to Mauretania. Focus centers upon the nature and degree of size and shape changes within the principal livestock, modifications that were in part influenced by aspects such as the scale and pattern in trade, dietary appeal for animal products (notably fatty meats), market demands, ecological adaptations, as well as economic and cultural contact among areas. Key similarities and differences in faunal patterns, across time and space within ancient North Africa, and the links these share with changes in animal husbandry schemes are outlined. [ABSTRACT FROM AUTHOR]

The annular Richat Structure, in Mauritania, is among the most striking geological features on Earth visible from space. Nicknamed "the Eye of Africa", its intriguing concentric shaping has drawn attention for several decades. Formerly hypothesized as an astrobleme, it is now consensually recognized as a complex igneous intrusion, involving two ring-like gabbroic bodies, a central breccia and carbonatite dykes. However, the coexistence of until now undated tholeiitic gabbros and 99 Ma carbonatites akin to alkaline magmatism remained enigmatic. We provide the first plagioclase 40Ar/39Ar age determination and new geochemical data on the gabbroic bodies. Although no robust age was obtained, numerical modelling of our results suggests that the gabbros were intruded between 230 and 200 Ma. This age bracket is compatible with the ∼200 Ma Central Atlantic Magmatic Province (CAMP). Moreover, the compositions of these tholeiitic gabbros match the two chemical groups of the CAMP the best represented in northwest Africa. Therefore, we argue that the Richat gabbros correspond to two CAMP sills intruded conformably into the Late Proterozoic/Lower Paleozoic sedimentary sequences of the Taoudenni basin. About 100 My later, the gabbros and their country rocks were locally uplifted by an alkaline intrusion (expressed now on surface by the carbonatites), resulting in a circular doming, 40 km in diameter. The subsequent erosion led to the actual flattened concentric structure. Therefore, the Richat Structure represents a two-stage igneous-history, separated by a time lapse of ∼100 My, resulting in two CAMP gabbroic sills mimicking ring-like bodies. • The annular Richat structure is one of the most striking geological features on Earth. • Magmatic rocks are present as carbonatites and tholeiitic gabbros. • We provide the first plagioclase 40Ar/39Ar age determination on gabbros. • Gabbros were intruded ≈ 200My ago, contemporaneously with the CAMP. • The Richat structure formed during two magmatic events separated by ≈100 My. [ABSTRACT FROM AUTHOR]

Mauritania, with its ancient (Archean to Paleoproterozoic) and desertic terrains and gentle relief, has been under-explored in terms of impact structures. To date, two confirmed impact craters, namely Tenoumer and Aouelloul, and four circular structures for which an impact origin has been suggested, are known in Mauritania. This work aims at a systematic exploration of circular structures in Mauritania and provide a comprehensive database to support their exploration and elucidate their origin. This approach includes multi-scale search on Google Earth images, and a preliminary assessment of their origin using available geological, geophysical, and geochemical data as well as Digital Elevation Models. A total of 50 new circular structures were detected during our survey, adding to four candidates previously identified. They are distributed throughout the territory with an important fraction of them being located in the Taoudeni basin. The diameters of these structures vary from 60 m to 7.5 km with a right-skewed distribution. A preliminary assessment of the possible origins of these circular structures is proposed and the most promising candidates for potential meteoritic impact sites are listed for future investigations. • 50 new circular structures have been found from a systematic survey of satellite imagery of Mauritania. • In total, 54 circular structures are preliminary examined based on morphological and geological data. • We list 6 structures with a possible impact origin and that deserve further investigation. [ABSTRACT FROM AUTHOR]

The occurrence of cold-water coral (CWC) reefs off Northwest Africa that has a broad oxygen minimum zone (OMZ) is poorly studied. A 400 km long almost continuous coral mound chain off Mauritania that was investigated by earlier expeditions revealed mainly dead corals. In 2021, the EAF-Nansen Programme conducted a survey at the border between Mauritania and Senegal with the main objective to map CWCs. Acoustic mapping with multibeam echosounder was used to target mounds at 450–650 m depth and 14 video lines were conducted using a remotely operated vehicle (ROV). The occurrence and health status of CWC reefs along video transects were annotated using the software "CampodLogger", oceanographic variables were measured using a CTD sonde, and terrain and backscatter analysis were conducted. Here we present the environment and health status of 13 Lophelia reefs established in the study area, six of them were large and healthy reefs with areas having 15–50% cover of live colonies. Oxygen concentrations were measured to be as low as 1 ml L−1 and temperature ranged from 8.8 to 11.6° C. We compare reef health with the environmental variables: temp, salinity, oxygen, and particle load. A GIS based model was developed to predict the occurrence of live reefs in the study area based on the observed average range of a set of terrain descriptors measured where live Lophelia reefs occurred. Our findings of healthy Lophelia reefs are unexpected and further north in the OMZ reefs have been described as dormant. There is an urgent need for visual seafloor mapping to aid the development of spatial management plans in these understudied waters. • Low oxygen concentration in the OMZ is not hindering the growth of Lophelia reefs. • Coral reef observations and modelled distribution indicates the presence of many reefs on the west Africa coast. • Our mapping of reefs has provided urgently needed information for coastal management. [ABSTRACT FROM AUTHOR]

Cold water corals (CWC) provide habitats for many organisms including demersal fish. Bottom trawl observations have indicated a co-occurrence of the fish Helicolenus dactylopterus with CWC reefs, but a detailed understanding of this relation is lacking. To better understand the nature of this relation we have analyzed 85 video-lines from ROV dives conducted at 25–1700 m depth off Morocco, Mauritania, and Senegal in 2020 and 2021. We annotated abundance, size, and behavior of the 552 specimens observed (32% juveniles and 68% adults), of these 82% occurred in CWC habitats at 400–600 m depth. Both juveniles and adults were observed standing on the seafloor. Our observations are discussed considering available knowledge on feeding ecology and life cycle of H. dactylopterus. Our findings show that CWC provides an essential habitat for this species at least during parts of its lifecycle, however, more behavioral studies are needed for an in-depth understanding of this association. • Our study shows that both juveniles and adults of H. dactylopterus are present within CWC habitats in the region. • TCWC habitats plays an important role by protecting H. dactylopterus females and juveniles against predation and currents. • This study increases our understanding of CWC reefs as habitat for H. dactylopterus and the need for reef protection. [ABSTRACT FROM AUTHOR]

The Hassi Abyad kaolin deposit is in the southern part of Mauritania, around 45 km east of the town of M'Bout. Hassi Abyad lies in the middle of the Mauritanides Shield, which consists of deformed and metamorphosed Precambrian and Paleozoic formations. Complementary geological, mineralogical, and geochemical studies have been carried out to help answer questions linked to the origin of these kaolin and to determine the potential suitability for different industrial applications. The mineralogical compositions showed that Hassi Abyad kaolin is mainly composed of kaolinite (61–96%) and other minerals such as chlorite, illite, muscovite, cronstedtite, quartz, rutile, magnetite, laumontite, and gibbsite. The average chemical composition of the kaolin samples is 35.84% Al₂O₃, 45.27% SiO₂, and 14.19% LOI. Other oxides occur in low concentrations (less than1%). The higher chemical indices of alteration CIA (99.5%) and CIW (99.6%) indicate that this kaolin deposit underwent a high degree of alteration during the process of kaolinization of the source rock. The absence of high temperature minerals such as pyrite, topaz and dickite, and the presence of high Ce + Y + La and Cr + Nb contents signifies that the development and evolution of this deposit are affiliated with supergene processes. This kaolin is derived from a lateritic material, proving that they are the source rock of this deposit. The geochemical and mineralogical characteristics indicate that Hassi Abyad kaolin is applicable in ceramics, paper, cosmetics, pharmaceutics, bricks making, and pottery. • Hassi Abyad kaolin is composed of kaolinite, quartz, chlorite, illite and gibbsite. • Lacking high temperature minerals, high Ce, Y, La, Cr, Nb indicate supergene origin. • High CIA and CIW indicate that the deposit formed underwent high alteration degree. • The deposit is applicable for ceramics, paper, pharmaceutics, bricks, and pottery. [ABSTRACT FROM AUTHOR]

The Aouelloul circular structure (Mauritania), 0.4 km in diameter, is a simple impact crater, which formed approximately 3 Myr ago. The Aouelloul crater was confirmed to be an impact crater based on the presence of an extraterrestrial component in glass fragments found around the crater, but so far, no convincing evidence of shock metamorphism in minerals, such as shocked quartz grains, is reported. The crater has been visited by a small number of geologists and limited information is available on deformations and impact-related effects at the macroscopic and microscopic scales. Detailed petrographic investigations of eight sandstone samples, all collected at the rim of Aouelloul during a 2019's field campaign, show that tectonic deformation lamellae occur in a number of quartz grains, but did not reveal any evidence of shock metamorphism. New observations on the distribution of the impact glass at the Aouelloul crater, exclusively located in the southern and eastern outer parts of the crater, suggest an oblique impact, from possible directions ranging from south-west to north (clockwise). Geological and lithostructural data are also presented and show that the rim of the crater is characterized by more or less disturbed metric to pluri-metric blocks of rocks showing fracturing and dipping toward either the interior or the exterior of the crater. This study confirms previous works conducted at the Aouelloul crater and illustrates the difficulty in demonstrating the impact origin of relatively small craters. • New petrological and structural data on Aouelloul a small impact crater of Mauritania. Distribution of impact glass suggests an oblique impact. [ABSTRACT FROM AUTHOR]

Radionuclides from the reactor accident Fukushima Daiichi nuclear power plant were observed in the airborne aerosols at CTBT International Monitoring System (IMS) stations (MRP43, CMP13) in Africa. The maximum activity concentrations in the air measured in Mauritania were 186.44 10−6 Bq.m−3, 264.16 10−6 Bq.m−3 and 1269.94 10−6 Bq.m−3 for 134Cs, 137Cs and 131I respectively, and in Cameroon 16.42 10−6 Bq.m−3, 25.53 10−6 and 37.58 10−6 Bq.m−3 respectively for 134Cs, 137Cs and 131I. The activity ratio of 134Cs/137Cs is almost constant throughout the period of time relevant to this study due to their long half-lives of 30.2 years for 137Cs and 2.06 years for 134Cs. Whereas the 131I/137Cs activity ratio varies in time according to the radioactive decay with a half-live of 8.06 days for 131I and different removal rates of both radionuclides from the atmosphere during transport. The EMAC atmospheric chemistry-general circulation was used to simulate the emission and transport of the isotope 137Cs and map the deposition of the 137Cs deposition over Africa. • IMS stations in Africa (MRP43, CMP13) detected first 131I, caesium isotopes appearing with a delay of 6 days in Cameroon and 4 days for 134Cs in Mauritania. • The highest activity concentrations of fission products were found in Mauritania. • The EMAC atmospheric chemistry-general circulation was used to simulate the emission and transport of the isotope 137Cs and map the deposition of the 137Cs deposition over Africa. [ABSTRACT FROM AUTHOR]

Conophyton (Maslov) is a cylindroidal stromatolite form-genus characterized by nested conical laminae. Well-preserved Conophyton , up to 4 m tall and with basal diameters of up to 50 cm, are exposed in the Proterozoic Atar Formation of Mauritania, where many occur together, in growth position, as fields of individual columns spaced between 5 and 70 cm apart. The uniformity of these forms and their regular distribution suggest that they grew in quiet-water environments below wave base. Evidence for their penecontemporaneous organomineralization is indicated by nearby toppled examples of undeformed Conophyton forms alongside eroded lithified Conophyton fragments in carbonate breccias. Two characteristics of Conophyton have been used to classify the structures – the form of the lamination and the nature of its axial structure. A mathematical/physical model provides an explanation for the growth pattern of Conophyton. It predicts that coniform structures with thickened axial zones form when upward organic growth of a biofilm moderately exceeds the rate of its mineralization. The varying characteristics of these features between different forms of Conophyton are thought to reflect biomineralization of the decaying biofilm rather than differences in the composition of microbial communities. A modern example of a syngenetic mineralization process capable of producing similar structures has been observed in the contemporary sediments of Lake Preston, Western Australia, where benthic microbial mats are being transformed into coniform lithified crusts. The initial biomineralization of the coniform mat forms magnesium silicate that first coats and permineralizes web-like microbial extracellular polymeric substances (EPS) and then coalesces into a uniform mass that provides mechanical strength to the cones. At a later stage, massive carbonate crystal growth occurs that over-prints much of this texture, leaving only small, remnant areas of the magnesium silicate phase. Many fossil Conophyton are composed of dolomite, and the remains of the microbial communities responsible for their construction are rarely found, except in areas of chert within the Conophyton. It is suggested that Proterozoic Conophyton were constructed in a tranquil environment through the accretion of microbial mats that were syngenetically permineralized by a magnesium silicate such as a smectite. Later, much of the unstable smectite would be susceptible to diagenetic replacement by either dolomite, or chert in which remnants of microbes that had been coated or permineralized could, potentially, be preserved. [ABSTRACT FROM AUTHOR]

We describe the absolute and per capita numbers of megavoltage radiotherapy machines (MVMs) in Western Africa from 1969 to 2019. Western Africa was defined in accordance with the United Nations' delineation and inclusive of 16 countries. A literature search for publications detailing the number of cobalt-60 machines (COs) and linear accelerators (LINACs) in radiotherapy centres was carried out. Population data from the World Bank Group and crude cancer rates from the International Agency for Research on Cancer were used to calculate ratios of million persons per MVM and MVMs per 1000 cancer cases. The numbers of MVMs in Western Africa in 1969, 1979, 1989, 1999 and 2009 were zero, two, three, six and nine, respectively. In 2019 there were 22 MVMs distributed across Ghana (five), Côte d'Ivoire (two), Mali (one), Mauritania (two), Nigeria (nine) and Senegal (three). Nine countries (56.3%) had no history of external beam radiotherapy (EBRT). The largest increase in absolute EBRT capacity occurred from 2017 to 2019, during which 13 MVMs were commissioned. The largest decrease in EBRT capacity occurred from 2015 to 2017, during which four LINACs and three COs were rendered non-operational. The ratio of million persons per MVM improved from 67.0 in 1979 to 17.8 in 2019. As of 2019, there was 0.09 MVM per 1000 cancer cases. Western African nations have experienced an increase in the absolute number of MVMs and per capita radiotherapy capacity during the last 50 years, especially in the last decade. As non-functional LINACs contributed to a temporary decline in the EBRT infrastructure, dual use of CO/LINAC technologies may act to promote the availability of EBRT treatment in centres with capacity for multiple MVMs. • Seven of 16 Western African countries have a history of external beam radiotherapy capacity. • The number of megavoltage machines in Western Africa increased from 0 in 1969 to 22 in 2019. • Three countries opened radiotherapy centres after 2009, accounting for nearly 25% of megavoltage machines present in 2019. • The ratio of million persons per megavoltage machine improved from 67.0 million in 1979 to 17.8 million in 2019. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electricity consumption is mapped using a combined cartographic methodology. • State of the sky impact is explored for the first time on energy management strategies. • LF strategy provides the best load monitoring by minimizing the generator uptime. • Energy management strategies play a pivotal role as hybrid solar system control tools. A novel optimized sizing and management strategy of a grid-connected hybrid photovoltaic (PV)-solar-battery-group system were proposed for the electrification of residential consumers in Northwest Africa (a case of Mauritania), and the influence of the state of the sky (clear, moderately overcast, and overcast) was analyzed according to the load flowing (LF) and the cycle charging (CC) strategies. In order to mitigate the pressure on the national grid, consolidate the consumer autonomy, minimize the cost of medium- and long-term consumption bills, and CO 2 -related emissions, a cartographic approach was conducted as the first attempt to map the electricity consumption potential for buildings in the city of Nouakchott (Mauritania) using a geo-referenced database. ArcGIS®, HOMER Pro®, and MATLAB® softwares were used for the establishment of the load profile, optimized sizing of the PV-batteries-group-grid system, and calculation of the lightness index, respectively. The LF strategy provided the best monitoring of the load throughout the day by minimizing the generator uptime. The techno-economic analysis revealed the values of cost of energy (COE) and net present cost (NPC) as follows: COE = $0.0549/kWh and NPC = $24,796 for the LF PV-batteries-grid strategy, COE = 0.0646 $/kWh and NPC = $23,380 for the CC PV-batteries-grid strategy, and COE = $0.17/kWh and NPC = $23,262 for the case of the grid on its own. [ABSTRACT FROM AUTHOR]

This study presents an assessment of the role of fisheries certification programmes in the management of fisheries in Mauritania, with the example of the small pelagic fishery. We show how the industry and authorities in Mauritania are taking advantage of the pressure for certification in the international supply chain to mobilise resources to make improvements in fisheries management and science on the ground, via the medium of a Fisheries Improvement Project (FIP) and through collaboration with a fisheries certification organisation (MSC). We consider the recent expansion of the fishmeal industry and the management needs of the fishery in this context (for example, controlling capacity, rationalising management measures by fleet, moving fishing grounds away from sensitive areas, reducing wastage etc.). We evaluate the role of these projects, driven by certification objectives, in contributing to progress. We consider how a similar private-sector driven model might be applied in neighbouring West African countries (Senegal, Gambia and others) and what barriers might exist in these countries in comparison to Mauritania. [ABSTRACT FROM AUTHOR]

The Maghreb region comprises five countries: Algeria Libya, Morocco, Mauritania, and Tunisia. This is a review aiming at providing an update on the situation of transfusion in the five countries. Three countries have developed regulations covering all transfusion-related activities including policy development. All the countries are running blood safety activities using a National Blood Service as the main entity. Except for Mauritania and Lybia, all the blood safety activities are centralized and conducted regularly. The blood safety indicators are globally better compared to those of sub-Saharan Africa. Despite the efforts of the states of the Maghreb region, and the progress made in the field of transfusion in these countries, shortcomings persist and concern virtually all the key elements of a national blood supply system mainly in the quality management system. [ABSTRACT FROM AUTHOR]

Hepatitis B and D infections are highly endemic in Mauritania, with prevalences ranging from 10 to 20%. With the present prospective transversal pilot study, we aimed to evaluate the prevalences of HBV, HCV, and HDV infections in healthcare workers (HCWs), and offer treatment or vaccination as required. At inclusion, each HCW was screened for anti-HBc Ab (followed by HBsAg assay when positive). Additional biological analyses were performed for HBsAg + cases. Depending on the results, HBV vaccination or anti-viral treatment was offered. A total of 3,857 HCWs were included, of whom 1,363 tested negative for anti-HBc Ab and received full vaccination. Of the 2,494 HCWs who were positive for anti-HBc Ab, 1,246 were positive for anti-HBs Ab and 418 were positive for HBsAg. Three HCWs were positive for HBeAg; 66 and 18 had HBV DNA levels respectively > 2,000 and > 20,000 IU/mL; and 48 were positive for anti-HDV Ab among whom 10 were positive for HDV RNA. HCV prevalence was 0.5%. Only seven HCWs fulfilled the criteria for treatment and five of them were treated. Few HCWs in Mauritania are immunised against HBV. The prevalences of anti-HBc Ab and HBsAg observed in this work were similar to those observed in our earlier works, whereas prevalence of active HDV infection was less high. HBV and HDV infections are a serious health concern in Mauritania. New recommendations developed in accordance with WHO guidelines should include mandatory HBV screening and immunisation for HCWs. [ABSTRACT FROM AUTHOR]

• The array capture loss ranges vary from a minimum value of 1.63 h/day to a maximum value of 2.46 h/day. So the system loss is relatively stable with an average value of 0.12 h per day. • The monthly performance ratio varies from 0.61% in August to 0.71% in November with a monthly average value of 0.66%. • The monthly average capacity factor achieves its maximum in October (20.54%) and its minimum in January (11.66%). • Two models are proposed for the evaluation of Edc and Eac energies as a linear function on insolation and module temperature with a coefficient of determination (R2) value of 0.96. Amid all renewable energies, solar PV is of particular interest, mainly in Africa. Mauritania is an example of African countries which, gives great concern to produce electricity via PV installations. This study is carried out on the performance evaluation of a 954,809 kWp photovoltaic array made up of micro-amorphous silicon situated in Nouakchott (capital of Mauritania) at Sheikh Zayed solar power plant. The measures of one year of operation from September 2014 to August 2015 were evaluated according to the IEC 61724. The results obtained demonstrate that the photovoltaic array performances depend on both insolation and environmental conditions. The array capture loss ranges vary from a minimum value of 1.63 h/day to a maximum value of 2.46 h/day. So, the system loss is relatively stable, with an average value of 0.12 h per day. The monthly performance ratio varies from 0.61% in August to 0.71% in November, with a monthly average value of 0.66%. The monthly average capacity factor achieves its maximum and minimum in October (20.54%) and January (11.66%), respectively. The energy generated by the PV array (Edc) and the energy fed to the utility grid (Eac) during November moth, are affected by the insolation and the module temperature. However, wind speed variation does not influence those energies. Two linear models, depending on insolation and module temperature, are proposed for the evaluation of Edc and Eac during this month. These laters present a coefficient of determination (R2) of 0.96. [ABSTRACT FROM AUTHOR]

One of the most profound byproducts of the Great Oxidation Event (GOE) was the onset of oxidative weathering on land and the riverine delivery of sulfate to marine systems. Although the exact nature of marine oxygenation in the aftermath of the GOE remains uncertain, marine sulfate likely remained below 2 mM until the late Mesoproterozoic and may have remained <10 mM through the Neoproterozoic. Prior to the late Mesoproterozoic, precipitation of sulfate minerals were inhibited by low marine sulfate and possibly by elevated carbonate saturation. By ∼1.1 Ga marine sulfate concentrations were sufficient to sustain the earliest widespread evaporite deposition. Low sulfate concentrations, however, influenced both the deposition and diagenesis of evaporite deposits. Here we investigate unusual limestone deposits in the 1.1 Ga Atar Group, Mauritania, that contain both macroscopic and microscopic features that suggest a primary origin as gypsum. Elevated concentrations of carbonate-associated sulfate (CAS), sodium, and potassium are consistent with primary deposition as a sulfate evaporite and subsequent calcification under low water-rock ratios. Isotope and elemental compositions further indicate diagenetic recrystallization under marine to hypersaline marine conditions. Combined, these observations show the potential for recognizing key evaporite facies in the rock record and support a growing recognition of late Mesoproterozoic evaporite deposits. • Evaporite deposits provide critical constraints on oxygenation of the Precambrian Earth. • Understanding marine sulfate concentrations is limited by gypsum preservation. • Marine sulfate concentrations were sufficient by late Mesoproterozoic to precipitate gypsum. • Late Mesoproterozoic calcitized evaporites provide information on deposition and diagenesis. • Fluid modeling suggests calcitization primarily by sea-water inundation of evaporite deposits. [ABSTRACT FROM AUTHOR]

In the northwestern Mauritanian Taoudeni Basin, the famous Richat structure is the only occurrence known of carbonatite. Despite several studies on this unique geological feature, the mineralogy and petrogenesis of the Richat dome carbonatites are underdocumented.Major, trace element whole rocks and carbon-oxygen isotope data are reported for Cretaceous carbonatites from Richat dome in Mauritania. More than 45 carbonatite dykes have been mapped, they are oriented N°15-N°80. Based on color, four groups have been identified, dark, gray, red breccia, and brown carbonatites. They exhibit different mineralogical and texture characteristics. The studied carbonatites are mainly composed of dolomite, calcite, and ankerite, with lesser amounts of apatite and quartz. Accessory minerals such as pyrochlore, spinel, pyrite, chalcopyrite, magnetite, hematite, baryte, phlogopite, and zircon are also present. Other REE-bearing minerals (britholite, monazite, and bastnaesite) were revealed by X-ray diffraction.Three types of carbonatites are identified: magnesiocarbonatites (dominants), ferrocarbonatites and calciocarbonatite. The presence of spinel and pseudomorphed olivine, as well as high contents of Ni (380 ppm), Co (34 ppm), and Cr (840 ppm) in the dark and brown carbonatites, suggests that these rocks are the result of the low-degree partial melting of a spinel-bearing peridotite. Furthermore, the Zr/Hf (48–80) and Nb/Ta (26–48) ratios show significantly higher values than those observed in the primitive mantle, they are interpreted as formed by partial melting of the metasomatized mantle. The high values of δ18O in addition to the presence of baryte, ankerite, and quartz in the Richat carbonatites suggest that they are the result of secondary processes involving a low-temperature fluid-rock interaction.The carbonatites from the Richat dome are enriched in LREE (La = 258–1070 ppm) and LILE as Sr, Ba, Th, U, and depleted in HREE (Yb = 2–14 ppm) and HFSE such as Zr, Hf, Ti. These characteristics are like those of Cretaceous peri-atlantic alkaline carbonatites such as Barra do Itapirapua in Brazil, Ondurakorume and Kalkfeld in Namibian, lupangola in Angola, and Twihinate in Morocco. Reactivation of a deep pan-African NNE-SSW lineament would have been a fundamental factor in the formation of the Richat carbonatites. • The Cretaceous Richat carbonatites were generated by partial melting of the metasomatized mantle. • The partial melting occurred under significant structural influence. • The genesis of the Richat carbonatites was strongly influenced by hydrothermal activity. [ABSTRACT FROM AUTHOR]

This paper describes the fisheries and presents quantitative stock assessments for two stocks of Sardinella in the waters of NW Africa. More robust stock assessments are now possible because of improved sampling in Mauritania and Senegal. Round sardinella (S. aurita), which has a wider distribution than flat sardinella (S. maderensis), is the most important species targeted by the different artisanal and industrial fleets. The industrial fleet is located beyond 13 miles from the coast, taking mainly adults. The average size in the offshore fishery, although it has decreased, remains above 26 cm. The species is also exploited by an artisanal fleet using small purse seiners. Two types of assessment model were applied: a production model and size-based model. The abundance indices were consistent, and showed a continuous decline, increasing in rate in recent years. The Just Another Bayesian Biomass Assessment (JABBA) model (applied for the first time) appeared to be appropriate for the abundance indices (Root Mean Squared Error (RMSE) 18.3–19.2 % for the two models). The results of the two models are consistent in showing increasing fishing mortality and declining biomass for both stocks over the time series. According to the JABBA model, the situation for the round sardinella stock is now critical (biomass at approximately 5 % of unexploited biomass (B0) and 10 % of biomass capable of producing maximum sustainable yields (Bmsy), with fishing mortality 2.5 times above Fmsy), and the flat sardinella is also overfished and suffering massive overfishing (B estimated at 18 %B0 and 25 %Bmsy, with fishing mortality more than 11 times above Fmsy). The results of the Length-based Bayesian Biomass (LBB) model are much more optimistic. It still concludes that both stocks are suffering overfishing (round sardinella F at ∼1.4 times Fmsy proxy, flat sardinella ∼2.2 times Fmsy proxy), but estimates that only the flat sardinella is overfished (B 28%B0 and 80 %Bmsy), while the round sardinella stock is not overfished (B 40 %B0 and 120 %Bmsy). However, these results are not consistent with the abundance index from acoustic surveys (used in the JABBA model) and overall are thought to be less robust. Signs of heavy exploitation have been observed for round sardinella for several years. This situation has been exacerbated since the arrival in late 2016 in the Mauritanian zone of efficient semi-industrial purse seiners targeting small pelagics. The various indirect assessment models used show a difficult stock situation for the round sardinella, on which many fishing communities in the area depend. Abundance indices from acoustic survey confirm the state of overexploitation of this resource. This situation has directed effort towards the flat sardinella, which is characterized by a more coastal distribution and limited migration. This species has been showing signs of overexploitation since 2019. We highlight this result for flat sardinella, which was previously not thought to be overexploited, and propose that managers should also consider how the estimated maximum sustainable catch and fishing mortality can be appropriately distributed between the different fleets in different countries, to ensure that future industry planning in the countries of the region is compatible with the sustainability of these critical stocks. This is a very complex task, as it involves not only discussions between neighboring countries, but also difficult decisions within countries about the economic and socio-economic importance of different fisheries sectors. It is essential that these reflections start immediately. [ABSTRACT FROM AUTHOR]

Effective spatial fisheries management requires a proper understanding of the spatial distribution of both target species and discards. Also, spatial modelling of fishery-dependent data is an effective tool to capture uncertainties in data-limited situations. This study analyses the drivers behind discarding by comparing the standardising properties of three different components: Total Discards, Discards Per Unit of Effort and Total Discard Ratio. These metrics were analysed by means of Bayesian hierarchical spatio-temporal Gamma regression models to correctly to identify areas with high discards values that are characterized as discards hotspots. Our results showed that Total Discards is the component which better quantified the aggregated ecological impact of discarding practices, whereas Total Discard Ratio and Discards Per Unit of Effort identify complementary issues of benefits versus loss of biomass. Spatial maps obtained by combining these three approaches are a powerful tool for the spatial management of discards. [ABSTRACT FROM AUTHOR]

In Mauritania, as in many developing countries, malnutrition in children under five is a public health problem, one of the control strategies for which is the anthropometric assessment of nutritional status. Child malnutrition is conventionally assessed by three indicators of nutritional status made up of anthropometric measurement indices, namely wasting (weight/height), stunting (height/age) and underweight (weight/age). However, these indicators are criticized for underestimating the prevalence of malnutrition since these overlap. The objective of this study is to assess the nutritional status of children through these aforementioned indices using MICS 2015–2016 data from Mauritania. The data for this study are through these anthropometric indices mentioned above using data from a Multiple Indicator Cluster survey [MICS5 Mauritania (2015–2016)]. To assess the nutritional status and estimate the situation of children and women in Mauritania at the national, regional level, in the area of residence and for certain socio-demographic characteristics of the households (Enquête par Grappes à Indicateurs Multiples 2007). The study involved 8927 healthy children aged 0 to 59 months (5025 subjects from rural areas, 3902 from urban areas), randomly selected during their visit to maternal and child health offices. Data on socio-economic and demographic level were collected using a questionnaire. Several variables were collected to characterize the mothers of the children surveyed, including age, household size, number of children, occupation, level of education, occupation of head of household and type of housing. Of the three anthropometric indices used to assess the nutritional status of children: weight-height, weight-age, height-age, only the weight-height index was retained for the study. It has the advantage of examining the short-term effects of malnutrition and of measuring the prevalence of global acute, moderate and severe malnutrition. This index was used in these two forms: weight/length, in children under 5 years old, and weight/height for children 0 to 5 years old. The data were entered and analyzed by the SPSS software (version 10). The association between potential risk factors and malnutrition is measured using a logistic regression model. The results show that all the children studied (8927), 50.50% are boys, 49.50% are girls; 43.71% reside in urban areas; 56.29% in rural areas. The average age of the children is 31.9 months ± 15.5 months and the average height is 86.8 cm ± 11.9 cm and the average weight is 11.35 kg ± 2.95 kg. The prevalence of malnutrition among children is 29.58% are stunted, 25.81% underweight and 14.91% wasted. The prevalence of child malnutrition is significantly related to age and area of residence, while the male and female sex of the children surveyed was greater in rural than urban areas. The age and educational level of mothers play a key role in child malnutrition. Based on our results, we propose a series of economic and social policy measures that would take into account all of these factors and help improve the nutritional status of children aged between 0 and 5 in Mauritania. Malnutrition is a major health problem in the Sahel and Mauritania. The nutritional status of the mothers of the children, the place of residence, the ethnicity and the age of the children negatively influence the nutritional status of the children. Indeed, the causes are multifactorial and require joint interventions which imply integrated actions with certainly socio-health components but also of food security, education ... This imposes an intersectoral development policy beyond the fight against malnutrition. Given the failure to achieve the Millennium Development Goals, decision-makers should take into account other relevant suggestions, such as those shown in this document, in the monitoring and care of failed children. anthropometric. This could help combat more strategically the malnutrition raging in Mauritania in order to achieve the second target of the Sustainable Development Goals by 2030. [ABSTRACT FROM AUTHOR]

Highlights • Major, trace and 142–143Nd of mafic rocks from WAC. • 143Nd errochron age of 3300 Ma. • No 142Nd anomaly in any of the mafic samples analysed. • Trace element and 142–143Nd data unable to distinguish geodynamical regime. Abstract Determining the extent of mantle mixing during the Hadean-Archean is an integral factor in our understanding of early geodynamic processes as well as the speed and degree of mantle homogenisation. If a dynamic convecting mantle was the predominant regime it would be expected that early formed isotopic anomalies would be quickly homogenised, whilst in a stagnant lid regime these anomalies might last for hundreds of millions of years. Archean terranes are dominated by felsic tonalite, trondhjemite and granodiorite rocks, as such these rocks have been the main rock type studied, even though they are not formed by primary mantle melts. Therefore, in this study, we have focused on mafic rock samples as tracers of primary mantle melting, from the relatively unknown West African craton. The mafic rocks have undergone metamorphism to granulite facies with the majority of samples retrogressed to amphibolite facies. Major element compositions reveal that the protolith was tholeiitic basalt. The majority of trace elements display limited mobility, as primary correlations with Zr are still present. Trace element patterns are typical for Archean mafic rocks, with Nb-Ta and Ti depletions. The meta-basalts yield a 147Sm-143Nd errorchron with an age of 3300 ± 300 Ma, with initial εNd of +4.4. The Nd compositions indicate that the meta-basalts have experienced minimal crustal assimilation and retain primary geochemical attributes. A positive initial εNd for the meta-basalts suggests that the magmatic protolith evolved from an already differentiated source. Nevertheless, 142Nd compositions are within error of modern day terrestrial, as such, the protolith for these samples either did not experience any early differentiation, or that mantle convection had homogenised any anomalous signal. These results highlight the lack of large (>±8 µ142Nd) 142Nd anomalies detected from outside the North Atlantic and Superior Cratons, suggesting that Archean mantle dynamics was complex, with different processes occurring on different parts of Earth, similar to today. [ABSTRACT FROM AUTHOR]

Abstract Introduction Rotavirus vaccine was introduced in Mauritania in December 2014. We investigated hospitalizations with diarrhea during pre and post-vaccination periods among children aged 0–5 years in Nouakchott, the capital of Mauritania. Methods We conducted a retrospective review of hospital admission registries from November 1st 2012 through October 31th 2017 at all referral hospitals in Nouakchott. We described admissions of children aged 0–5 years by diagnosis, data of admission, age and sex, and compared the proportion of all childhood hospitalizations with diarrhea before and after rotavirus vaccine introduction. Results In total, 6552 (19%) of all 34,329 hospitalizations in 0–5 year-olds had diarrhea. Of these, 3523/16,952 (20.7%) were recorded during the pre-vaccine period, 1373/6897 (19.9%) during the transition period (November 2014-October 2015), and 1656/10,480 (15.8%) during the post-vaccination period. The proportion of all childhood hospitalizations with diarrhea during the pre-vaccine period was 22.6% among males and 18.7% among females. Approximately one third (32.3%) of hospitalizations with diarrhea occurred in children aged 6–11 months. During the post-vaccination period, the proportion of hospitalizations with diarrhea declined by 24%, and the highest reduction (74%) was observed in children aged 2 to 5 years (P < 0.001). Conclusions The proportion of childhood hospitalizations with diarrhea in Nouakchott was reduced by about one fourth after introduction of rotavirus vaccination in Mauritania, indicating a major impact for public health for children in the capital city. [ABSTRACT FROM AUTHOR]

Abstract Over the past 30 years, the promotion of alternative occupations has been central to livelihood-centered conservation projects (LCP). However, continued pressure on protected areas and high poverty levels in surrounding communities suggest that other LCP approaches may be needed. One historically understudied approach focuses on enhancing pre-existing livelihood strategies to achieve conservation and development goals. We assessed the efficacy of the alternative occupations and pre-existing livelihood strategies approaches to LCPs using two case studies of adjacent protected areas along the Senegal River in West Africa. One community in Senegal promotes tourism as an alternative occupation; another in Mauritania builds on the local fishing-farming mixed livelihood strategy. From 2014 to 2015 we used qualitative methods (e.g. semi-structured interviews and participant observations) to examine each LCP's capacity to deliver positive conservation and development outcomes, focusing on perceived outcomes on local livelihoods and conservation goals. Overall, LCP which focused on the pre-existing fishing-farming livelihood strategy received more positive perceptions in terms of enhancing local livelihoods, fostering positive conservation behaviors, and improving park-community relations. We conclude that these observed outcomes stem from acknowledgment of and adherence to local needs and priorities within the context of local vulnerability and a park management approach that fostered a sense of resource ownership. In places where alternative occupations like tourism have not succeeded in delivering positive conservation and development goals, this paper presents an alternative strategy that is rooted in the social and environmental realities of local communities. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Mature/spawning animals have a wide size range and considerable non-empty stomachs. • Reproductive system develops at a steady pace with maturity. • Small oocytes predominate throughout sexual maturation. • Ovarian development is asynchronous, evidenced by bimodal distribution of yolk oocytes size-frequency. • About 770–1966 viable eggs are serially released, depending on body size. Abstract Cephalopod species have evolved highly flexible spawning strategies, but the extent to which spawning strategy adopted is inextricably linked to the ovarian development. To address the spawning strategy of common cuttlefish S epia officinalis outside northwest Africa, an analysis of ovarian development and hypothesis on spawning pattern was undertaken for specimens (mantle length of 126–270 mm from stages II to IV) collected from commercial catches off Mauritania during summer months of July and August 2015. It was found that the mature/spawning female S. officinalis covered a wide range of body size, being 148–270 mm ML, and showed non-stop food intake. The gonadosomatic index (GSI) increased steadily with maturity from 2.13% to 13.22%, being higher mean value of 8.65 ± 1.69% at mature/spawning stage. Potential fecundity (PF) increased with female size from 1306 to 3376 oocytes (mean 2327 ± 554.47). The oocytes were developing asynchronously as evidenced by the dominant small oocytes throughout sexual maturation and a bimodal size-frequency distribution of yolk oocytes for animals at maturing and mature/spawning stages. The mature oocytes in ovaries of mature/spawning individuals consistently accounted for less than 1% PF. There were about 770–1966 viable eggs that would be released during the spawning season. These evidences indicate that S. officinalis off Mauritania undergo the asynchronous ovarian development, and adopt a complementary spawning strategy falling somewhere along a continuum between intermittent and multiple spawning to adapt to the nutrient-rich Mauritanian upwelling system. [ABSTRACT FROM AUTHOR]

Elasmobranchs are among the most vulnerable marine fish and the most impacted by fishing. In Mauritania, although many management and prohibition measures have been introduced, this taxonomic group continues to be caught and landed. To follow trends of catches and catch species composition by the different fishing fleets in Mauritania we used the data from the fisheries monitoring system set up by the Mauritanian Institute of Oceanographic Research and Fisheries (IMROP) collected since 2006 in the National Park of Banc d′Arguin (PNBA). These data are supplemented by the monitoring data on the artisanal, coastal, and deep-sea fisheries, and the data from the scientific demersal trawling campaigns in the Mauritanian Exclusive Economic Zone (EEZ) that IMROP has been conducting since 1982. The results show that elasmobranch catches are highest in the artisanal and coastal fisheries, particularly in the PNBA, where several conservation measures for these species have been put in place. These results suggest that there is a need to strengthen the implementation of the shark management plan by a strict application of the prohibition of gear targeting these species. [ABSTRACT FROM AUTHOR]

Ticks are known as vectors and reservoirs of rickettsiae and, wildlife vertebrate hosts as suitable dispersers of ticks contributing to the life cycle of rickettsial agents in nature. In the herein study, the presence of rickettsiae was investigated in ticks from wild mammals (Gerbillus and Jaculus, Vulpes rueppellii, Canis anthus, Felis lybica and Felis margarita) in Mauritania and Morocco. Morphological and molecular analysis of ticks allowed their identification as Rhipicephalus sanguineus sensu lato and Hyalomma impeltatum. A total of 126 partially engorged adult ticks, collected from 40 animals, were screened for the presence of rickettsial DNA by conventional PCR targeting the ompB gene, followed by ompA and gltA targets and bidirectional sequencing. As a result of the sequence analyses, that at least three different species of pathogenic spotted fever group rickettsiae were detected. Rickettsia parkeri -like was detected in a R. sanguineus s.l. (n=1) collected from an African wildcat from Morocco. Rickettsia aeschlimannii was detected in a H. impeltatum (n=1) collected from a gerbil rodent. Rickettsia massiliae was detected in R. sanguineus s.l. ticks (n=5) collected from two Ruppells' foxes. The herein study demonstrates that pathogenic Rickettsia species are circulating in Morocco and Mauritania wildlife. [ABSTRACT FROM AUTHOR]

This study investigates the movements, patterns, and size distribution of little tunny (Euthynnus alletteratus) in the Eastern Central Atlantic Ocean. Data were collected as part of the ICCAT Atlantic Ocean Tuna Tagging Programme (AOTTP) through conventional tag release-recapture experiments. The study analyzed data from 7870 tagged fish, of which 452 were recaptured between 2016 and 2020. The results indicated that little tunny could travel long distances, with some fish covering up to 600 Nm between Mauritania and Côte d'Ivoire. The movement patterns of tagged fish varied, and there appeared to be some exchange of fish between Senegal-Mauritania and the Gulf of Guinea through the Côte d'Ivoire Exclusive Economic Zone (EEZ). The recapture rate was the highest within the first month after release, with half of the tagged fish recaptured within this period, then approximately 17 % and 11.5 % of tagged fish were recaptured within 60 and 90 days, respectively. The size distribution of tagged and recaptured little tunny varied by area with statistically significant differences between Côte d'Ivoire – Gulf of Guinea and those from Mauritania to Liberia. The recaptured fish were larger than the tagged fish in all areas studied, suggesting a significant growth of individuals (4.2 cm per quarter). In conclusion, this study highlights the extensive movements and migration patterns of little tunny in the Eastern Central Atlantic Ocean. These findings suggest that factors such as Anchored Fish Aggregating Devices (AFAD) may influence the mobility of fish in certain areas and that the size distribution varies significantly between different regions. • Very few movements of little tunny have been observed between Mauritania and Côte d'Ivoire indicated. • Highest recapture rate (50 %) within the first month after release. • Evidence of individual growth based on tag-recapture data of little tunny. • Anchored fish aggregating devices may influence the mobility of little tunny between areas. [ABSTRACT FROM AUTHOR]

Evaluating the ecotourism potential of sites is a key issue in tourism management. Multiple methodologies have been developed to assess the ecotourism potential of sites. However, there are many constraints affecting their quality. Methodologies independent of subjective criteria and weights are lacking, compromising following interpretations on where to allocate efforts for ecotourism development. We propose a new approach to circumvent these issues that combines independent statistical procedures to assess ecotourism potential. By combining multi-criteria with ordination and clustering algorithms, this two-stage statistical approach allowed identifying suitable water-bodies for ecotourism development in Mauritania and independently assessed which features are related with ecotourism potential. The method was able to group sites for different ecotourist demands, which has implications for policy makers and tourism planners trying to optimize investments while protecting biodiversity and supporting communities. We provide a framework that is scalable and applicable by stakeholders operating in ecotourism planning and management worldwide. [ABSTRACT FROM AUTHOR]

Résumé Objectif Déterminer la prévalence et les facteurs de risque associés de la candidose vulvo-vaginale chez les femmes enceintes en Mauritanie. Patients et méthode L’étude s’est déroulée au niveau du laboratoire du centre hospitalier Mère et Enfant de Nouakchott, du 1 er novembre 2016 au 5 février 2017. Elle a concerné toutes les femmes enceintes en troisième trimestre venues en consultation prénatale au niveau du service de gynécologie et adressées au laboratoire pour suspicion de candidose vulvo-vaginale. Ces femmes ont toutes donné leur consentement éclairé sous forme écrite. Après avoir rempli le questionnaire en vu de recueillir les données épidémiologiques et cliniques, un prélèvement a été effectué pour la réalisation d’un examen direct à l’état frais et d’une culture sur milieu de Sabouraud additionné de chloramphénicol. Résultat Deux cent femmes enceintes ont été incluses dans l’étude. La culture sur milieu Sabouraud-Chloramphénicol a été positif chez 52 patientes, se qui correspond à une prévalence de 26 %. Le test de filamentation a été positif pour 61,5 % des Candida isolés. Les signes cliniques de la CVV ont été dominés par les leucorrhées (56 %), les douleurs pelviennes (25 %) et les prurits vulvaires (11 %). Parmi les femmes présentant une culture positive à Candida , 55,76 % avaient reçu un traitement antifongique par voie locale sous forme d’ovule durant la grossesse. Conclusion Cette étude montre que la candidose vulvo-vaginale est fréquente chez les femmes enceintes suivies en gynécologie au niveau du centre hospitalier Mère et Enfant de Nouakchott. Aim To determine the prevalence and the associated risk factors of vulvovaginal candidiasis in pregnant women in Mauritania. Patients and method The study was carried out at the laboratory of the Mère et Enfant Center in Nouakchott, from November 1, 2016 to February 5, 2017. It concerned all pregnant women in the third trimester that came to the natal consultation at the gynecology service. These women must have given their informed consent in written form. After completing the survey to collect epidemiological and clinical data, a sample was collected to perform fresh direct examination and culture on Sabouraud-Chloramphenicol media. Results Two hundred pregnant women were included in the study. Culture on Sabouraud-Chloramphenicol media was positive in 52 patients corresponding to a prevalence of 26%. The germ tube test was positive for 61.5% of isolated Candida . Clinical signs are dominated by leucorrhea (56%), pelvic pain (25%) and vulvar pruritus (11%). Among women with positive culture, 55.76% had received local antifungal treatment in the form of an ovula during pregnancy. Conclusion This study shows that vulvovaginal candidiasis is frequent in pregnant women attending gynecology at the Mère et Enfant Hospital Center in Nouakchott. [ABSTRACT FROM AUTHOR]

A multiannual, continuous sediment trap experiment was conducted at the mooring site CB eu (Cape Blanc eutrophic, ca. 20 °N, ca. 18 °W; trap depth = 1256–1296 m) in the high-productive Mauritanian coastal upwelling. Here we present fluxes and the species-specific composition of the diatom assemblage, and fluxes of biogenic silica (BSi, opal) and total organic carbon (TOC) for the time interval June 2003-Feb 2010. Flux ranges of studied parameters are (i) total diatoms = 1.2 ∗ 10 8 –4.7 ∗ 10 4 valves m −2 d −1 (average = 5.9 × 10 6 valves ± 1.4 × 10 7 ); (ii) BSi = 296–0.5 mg m −2 d −1 (average = 41.1 ± 53.5 mg m −2 d −1 ), and (iii) TOC = 97–1 mg m −2 d −1 (average = 20.5 ± 17.8 mg m −2 d −1 ). Throughout the experiment, the overall good match of total diatom, BSi and TOC fluxes is reasonably consistent and reflects well the temporal occurrence of the main Mauritanian upwelling season. Spring and summer are the most favorable seasons for diatom production and sedimentation: out of the recorded 14 diatom maxima of different magnitude, six occurred in spring and four in summer. The diverse diatom community at site CB eu is composed of four main assemblages: benthic, coastal upwelling, coastal planktonic and open-ocean diatoms, reflecting different productivity conditions and water masses. A striking feature of the temporal variability of the diatom populations is the persistent pattern of seasonal groups’ contribution: benthic and coastal upwelling taxa dominated during the main upwelling season in spring, while open-ocean diatoms were more abundant in fall and winter, when the upper water column becomes stratified, upwelling relaxes and productivity decreases. The relative abundance of benthic diatoms strongly increased after 2006, yet their spring-summer contribution remained high until the end of the trap experiment. The occurrence of large populations of benthic diatoms at the hemipelagic CB eu site is interpreted to indicate transport from shallow waters via nepheloid layers. We argue that a significant amount of valves, BSi and TOC produced in waters overlying the Banc d’Arguin and the Mauritanian shelf is effectively transported to the CB eu trap in intermediate waters at the outer Mauritanian slope. The impact of the intermediate and bottom-near nepheloid layers-driven transport in the transfer of valves and bulk particulates and its potential contribution to the export of biogenic materials from the shelf and uppermost slope might play a significant role in hemipelagial fluxes off Mauritania. [ABSTRACT FROM AUTHOR]

Methane can be released from the vast marine hydrate reservoirs that surround continents into oceans and perhaps the atmosphere. But how these pathways work within the global carbon cycle now and during a warmer world is only partially understood. Here we use 3-D seismic data to identify what we interpret to be a gas venting system that bypasses the hydrate stability zone (HSZ) offshore of Mauritania. This venting is manifested by the presence of the acoustic wipe-out (AWO) across a densely faulted succession above a salt diapir and a set of morphological features including a substantial, ∼260 m wide and ∼32 m deep, pockmark at the seabed. The base of the HSZ is marked by a bottom simulating reflector (BSR) which deflects upwards above the diapir, rather than mimicking the seabed. We use a numerical modelling to show that this deflection is caused by the underlying salt diapir. It creates a trapping geometry for gas sealed by hydrate-clogged sediment. After entering the HSZ, some methane accumulated as hydrate in the levees of a buried canyon. Venting in this locality probably reduces the flux of gas to the landward limit of feather edge of hydrate, reducing the volume of gas that would be susceptible for release during a warmer world. [ABSTRACT FROM AUTHOR]

Although aluminum is widely distributed in the earth's crust, its environmental availability and wildlife assimilation rates are only partially known. Here we analyze aluminum concentrations in bone from 10 species of marine mammals inhabiting 3 geographic areas subject to different aluminum inputs: the Río de la Plata estuary (Uruguay), the coastal waters of Mauritania and the Galapagos archipelago (Ecuador). Overall, concentrations were unusually high as compared to those of terrestrial animals, with lowest concentrations in the Galapagos archipelago, then the Río de la Plata estuary and finally Mauritania. The aluminum source varied between regions, prevailing anthropogenic sources in the Río de la Plata Estuary and natural sources (wind-blown dust) in Mauritanian waters. The type of source determined contamination levels: anthropogenic sources were most significant for coastal species and showed a decline with distance of habitat from shoreline, while natural sources had a higher influence on open waters because of the dearth of biogenic silica that eliminates aluminum from the water column. Since aluminum remains in bone for several decades, marine mammal bone reflects historical levels of aluminum and therefore is a good bioindicator of the aluminum concentration of the marine environment. [Display omitted] • We analyzed Al in bone of 4 pinnipeds and 6 cetaceans from 3 areas. • Al levels followed an increase gradient: Galapagos, Río de la Plata, Mauritania. • Main Al source for Río de la Plata was anthropic, for Mauritania wind-blown dust. • Anthropic sources had short-range impact, natural sources long-range impact. • Marine mammals are good bioindicators of Al contamination levels and type. [ABSTRACT FROM AUTHOR]

Drawing on empirical ethnographic research conducted in three resettled areas in Nouakchott (Mauritania), our paper aims to enrich the debate on land formalization, attempting to understand the effects of slum upgrading programs and the titling process. In a context of securing land tenure as upheld by international institutions, the paper questions the implementation of these titling programs, which aim to deliver secure tenure and, more broadly, achieve economic development. It appeals for an analysis of how poor people react to titling policies in a context of highly complex relationships between formal and informal land status. Our case studies show that formal deeds do not necessarily lead to secure tenure. For the impoverished households who have withstood resettlements, these titling practices can be seen as a way to improve their livelihoods or, on the contrary, as breeding grounds for new forms of vulnerability. Moreover, these elements can also be perceived as triggers for encroachments between the State and the law and, at times, a reason to claim new rights. [ABSTRACT FROM AUTHOR]

The well-preserved Meso-Neoproterozoic shallow marine succession of the Atar/El Mreïti Group, in the Taoudeni Basin, Mauritania, offers a unique opportunity to investigate the mid-Proterozoic eukaryotic record in Western Africa. Previous investigations focused on stromatolites, biomarkers, chemostratigraphy and palaeoredox conditions. However, only a very modest diversity of organic-walled microfossils (acritarchs) has been documented. Here, we present a new, exquisitely well-preserved and morphologically diverse assemblage of organic-walled microfossils from three cores drilled through the Atar/El Mreïti Group. A total of 48 distinct entities including 11 unambiguous eukaryotes (ornamented and process-bearing acritarchs), and 37 taxonomically unresolved taxa (including 9 possible eukaryotes, 6 probable prokaryotes, and 22 other prokaryotic or eukaryotic taxa) were observed. Black shales preserve locally abundant fragments of organic-rich laminae interpreted as benthic microbial mats. We also document one of the oldest records of Leiosphaeridia kulgunica , a species showing a circular opening interpreted as a sophisticated circular excystment structure (a pylome), and one of the oldest records of Trachyhystrichosphaera aimika and T. botula , two distinctive process-bearing acritarchs present in well-dated 1.1 Ga formations at the base of the succession. The general assemblage composition and the presence of three possible index fossils ( A . tetragonala , S . segmentata and T . aimika ) support a late Mesoproterozoic to early Neoproterozoic (Tonian) age for the Atar/El Mreïti Group, consistent with published lithostratigraphy, chemostratigraphy and geochronology. This study provides the first evidence for a moderately diverse eukaryotic life, at least 1.1 billion years ago in Western Africa. Comparison with coeval worldwide assemblages indicates that a broadly similar microbial biosphere inhabited (generally redox-stratified) oceans, placing better time constraints on early eukaryote palaeogeography and biostratigraphy. [ABSTRACT FROM AUTHOR]

Mauritania has recently developed a fishmeal industry based on small pelagics. The fish are caught by Senegalese canoes that work under charter for the fishmeal factories, most of which are situated in the northern port of Nouadhibou. After a slow start in 2005–2010, the industry showed a strong development after 2010 as the result of high prices for fishmeal and oil. Catches of small pelagics landed for fishmeal increased from 50,000 t in 2011 to 240,000 t in 2014. Because new factories were still being built by the end of 2014, a further expansion of the catches used for fishmeal is expected. Data are presented on the species composition of the catches for fishmeal, and the length distribution of the individual species. It is shown that the catches consist of round sardinella ( Sardinella aurita ), flat sardinella ( S. maderensis ), and bonga ( Ethmalosa fimbriata ). Changes in species composition and length composition from 2012 to 2014 may indicate different responses of the coastal stocks of small pelagics to the increased fishing pressure. Some of the species exploited for fishmeal belong to regional stocks that are shared with neighbouring countries. The paper discusses the potential effects of the expanding fishmeal industry in Mauritania on these regional stocks. [ABSTRACT FROM AUTHOR]

The collections as well as quantitative faunistic and environmental data obtained from 384 bottom-trawling stations during the four Spanish Maurit and two FAO–CCLME expeditions have allowed us, for the first time, to establish the biodiversity distribution patterns and assemblage structures of Mauritanian molluscs. The six surveys prospected the soft-bottoms of the shelf and continental slope between Cape Blanc (20°50′N) and the Senegalese border (16°04′N), from a depth of 19 to 1860 m. Almost 13,000 live specimens collected from 150 stations (40% of the total) belonged to 104 species (37 bivalves and 67 gastropods). Nassariidae and Xenophoridae were the most frequently found families, and the gastropod Nassarius wolffi (Knudsen, 1956) was the most frequent mollusc species in the Mauritanian soft-bottoms. Naticidae and Marginellidae, followed by Muricidae and Pectinidae, were the most diverse families. Depth and depth-related variables, besides the carbonate content of the sediments, are the major environmental factors responsible for the distribution patterns of the ecological descriptors as well as separation of the three main assemblages identified in the shelf, slope and deep-slope. Besides their dissimilarities (β-diversity), the three faunistic assemblages showed significant quantitative differences linked to similar and marked bathymetric trends of diversity, abundance and biomass of both bivalves and gastropods, which strongly decline from the shelf along the slope. Although the mean value of species richness seems uniform along the coast, abundances and biomass are the lowest in the southernmost zone (17°N–16°N), with the highest values, particularly for gastropods, in the Banc d'Arguin region. • The collections as well as quantitative faunistic and environmental data obtained from 384 bottom-trawling stations during the four Spanish Maurit and two FAO–CCLME expeditions have allowed us, for the first time, to establish the biodiversity distribution patterns and assemblage structures of Mauritanian molluscs. The six surveys prospected the soft-bottoms of the shelf and continental slope between Cape Blanc (20°50′N) and the Senegalese border (16°04′N), from a depth of 19–1860 m. Almost 13,000 live specimens collected from 150 stations (40% of the total) belonged to 104 species (37 bivalves and 67 gastropods). Nassariidae and Xenophoridae were the most frequently found families, and the gastropod Nassarius wolffi (Knudsen, 1956) was the most common mollusc species in the Mauritanian soft-bottoms. Naticidae and Marginellidae, followed by Muricidae and Pectinidae, were the most diverse families. • Depth and depth-related variables, besides the carbonate content of the sediments, are the major environmental factors responsible for the distribution patterns of the ecological descriptors as well as separation of the three main assemblages identified in the shelf, slope and deep-slope. Besides their dissimilarities (β-diversity), the three faunistic assemblages showed significant quantitative differences linked to similar and marked bathymetric trends of diversity, abundance and biomass of both bivalves and gastropods, which strongly decline from the shelf along the slope. Although the mean value of species richness seems uniform along the coast, abundances and biomass are the lowest in the southernmost zone (17°N–16°N), with the highest values, particularly for gastropods, in the Banc d'Arguin region. [ABSTRACT FROM AUTHOR]

• Integrated approach using the least-mobile trace element and Nd isotopes compositions to provide insights into the provenance of the fine-grained siliciclastic sediments from the Mesoproterozoic Atar and El Mreiti groups. • Paleoweathering indices reveal a moderate degree of chemical weathering in the source areas. • The concentrations of the relative immobile trace element suggest mixing sources of sediment provenance, which is dominated by felsic source rocks for the Atar sediments. • This study demonstrates distinct sediment sources between the Atar Group strata and those of El Mreiti. The Mesoproterozoic era is a crucial period in Earth history characterized by muted oxygen levels in the atmosphere–ocean system. This period is well represented in the non-metamorphosed sedimentary rocks from the Taoudeni Basin, Mauritania. Few studies have been carried out to trace the sources of these sedimentary archives. Here, we examined the sedimentary rocks from the Atar (S4 drill core) and El Mreiti groups (S2 and S3 drill cores). This study focuses on whole-rock elemental geochemistry and Sm/Nd isotope compositions to provide insights into the provenance of the fine-grained siliciclastic sediments from the basal part of the Mesoproterozoic Atar and El Mreiti groups. Paleoweathering indices reveal a moderate degree of chemical weathering in the source areas, consistent with the low compositional maturity of the studied samples. The concentrations of the relatively immobile trace elements suggest mixing sources of sediment provenance, which is dominated by felsic source rocks for the Atar sediments. However, distinctively positive Ɛ Nd(t) values coupled with high 143Nd/144Nd and Sm/Nd ratios and high ƒSm/Nd values of the sediments from the El Mreiti Group indicate derivation from juvenile and less evolved sources rocks. Further, the depleted mantle model ages (T DM) of the provenance protolith (1.95–2.31 Ga) support the argument that the El Mreiti sediments are dominantly sourced from the Paleoproterozoic terrane exposed in the eastern Reguibat Shield while the Atar Group were predominantly from the Archean basement rocks in the western Reguibat Shield. Moreover, Sm/Nd isotope and mixing model results support the major contributions of the felsic Archean rocks of the Reguibat Shield for the Atar Group samples. Although these strata, separated by ∼1000 km, have been described as stratigraphic equivalent, our study demonstrates distinct sediment sources between the Atar Group strata and those of El Mreiti, therefore, reinforcing the importance of sediment provenance in understanding the evolution and reconstruction of modern and ancient sedimentary systems. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM 2.5) from different source sectors might differ in toxicity. However, data from large-scale studies on vulnerable children in low- and middle-income countries (LMICs) are insufficient. To analyze the association of under-five death (U5D) with long-term exposure to PM 2.5 from different sources. We evaluated demographic and health survey data for 79,995 babies born in 2017 in 16 Asian and African LMICs (AA-LMICs) and a Latin America low-income country (i.e., Haiti). Long-term exposure to PM 2.5 was assessed by a well-established product that attributed the annual concentration to 20 source sectors in 2017. The associations of survival during < 5-year periods with each source-specific concentration of PM 2.5 were analyzed by Cox regression with multiple adjustments. We derived a multiple-pollutant ridge regression model to estimate the joint exposure–response function (JERF) between U5D and PM 2.5 mixtures. To evaluate how sources affected PM 2.5 toxicity, we evaluated the number of U5Ds attributable to PM 2.5 based on the source profiles for 88 AA-LMICs. According to the single-pollutant model, the risk of U5D increased by 7% (95% confidence interval [CI]: 5%, 9%) for each 10 μg/m3 increment in total PM 2.5 concentration. The model performance was lower than that of the multiple-pollutant ridge regression model. For each 10 μg/m3 increment in PM 2.5 , the excess risk of U5D ranged from 6% (95% CI: 4%, 9%) in Nepal to 10% (95% CI: 6%, 14%) in Mauritania. Based on the JERF, PM 2.5 contributed to 817,647 (95% CI: 585,729, 1,050,439), i.e., 28.0% (95% CI: 20.1%, 35.8%), of all U5Ds across the 88 AA-LMICs. The PM 2.5 -related U5Ds were mostly attributable to PM 2.5 produced by desert dust, followed by solid biofuel combustion and open fires. The average toxicity of PM 2.5 varied by source profile, which should be taken into consideration when planning public health interventions. For some AA LMICs, natural sources of PM 2.5 had the most significant health effects, and should not be ignored to ensure the protection of child health. [ABSTRACT FROM AUTHOR]

There is a remarkable paucity of estimates of the numeric importance of sea turtles at foraging grounds. The Banc d'Arguin (BA) is a vast shallow marine area off the coast of Mauritania, known as a site of world importance for coastal migratory birds and other biodiversity, including extensive seagrass beds. We sampled foraging green turtles on the BA, and extensively tracked adult female green turtles from the Bijagós archipelago, the only significant nesting aggregation within 3000 km of the BA, to estimate the abundance of this foraging aggregation. Additionally, we used a demographic simulation to support our findings. Based on satellite tracking of adult females (n = 46), we estimate that 50 % of the nesting population from the Bijagós migrate to the BA post-nesting. We combine data on numbers nesting in the Bijagós with information on proportion migrating to the BA in the same years to conservatively estimate that 8285 adult female green turtles forage at this site. We also estimate that adult females represent only 5.6 % of the green turtles in the BA, implying that the number of turtles there is of the order of 150,000 individuals. Most of the BA enjoys effective protection as part of the Parc National du Banc d'Arguin where significant fisheries regulations are well enforced by a marine surveillance program. We show that the BA is one of the major foraging sites for green turtles nesting in the Bijagós and a site of critical importance for immature and adult green turtles in a global context. • Estimates of sea turtle abundance in marine habitats are scarce. • In-water captures plus satellite tracking allowed for reliable abundance estimates. • The Banc d'Arguin in West Africa is a major developmental site for green turtles. • Foraging green turtles in the Banc d'Arguin are likely of the order of 150,000. • Our novel approach highlights a site of global importance for green turtles. [ABSTRACT FROM AUTHOR]

The Guelb Moghrein copper–gold deposit in the Islamic Republic of Mauritania reopened in 2006 and has produced copper concentrate and gold since then. The deposit is hosted in Neoarchaean–Palaeoproterozoic Fe–Mg carbonate-dominated metamorphic rocks interpreted as carbonate-facies iron formation. It forms tabular orebodies controlled by shear zones in the hanging wall and footwall of this meta-iron formation. Copper and gold are hosted in a complex sulfide ore in tectonic breccia replacing Fe–Mg carbonate and magnetite. Hydrothermal monazite dates the mineralization at 2492 ± 9 Ma. Two types of aqueous fluid inclusions suggest fluid mixing at 0.75–1.80 kbar and ~ 410 °C as the mineralization and precipitation mechanism, which is temporally coincident with regional retrograde metamorphism at 410 ± 30 °C (garnet-biotite). Distal alteration zones are enriched in K, Rb and Cu, whereas orebodies are depleted in K, Rb, Sr and Ba. The copper–gold mineralization at Guelb Moghrein formed during retrograde shearing in metamorphic rocks and contemporaneous hydrothermal alteration. The stable isotope signature of alteration and ore minerals suggest an external crustal fluid source. Fluids were focused in the reactive and competent meta-iron formation. Potassium alteration, magnetite and copper–gold mineralization suggest an IOCG mineral system akin similar deposits in Australia and Brazil. [ABSTRACT FROM AUTHOR]

The Tasiast gold deposits are hosted within Mesoarchean rocks of the Aouéouat greenstone belt, Mauritania. The Tasiast Mine consists of two deposits hosted within distinctly different rock types, both situated within the hanging wall of the west-vergent Tasiast thrust. The Piment deposits are hosted within metasedimentary rocks including metaturbidites and banded iron formation where the main mineral association consists of magnetite-quartz-pyrrhotite ± actinolite ± garnet ± biotite. Gold is associated with silica flooding and sulphide replacement of magnetite in the turbidites and in the banded iron formation units. The West Branch deposit is hosted within meta-igneous rocks, mainly diorites and quartz diorites that lie stratigraphically below host rocks of the Piment deposits. Most of the gold mineralisation at West Branch is hosted by quartz–carbonate veins within the sheared and hydrothermally altered meta-diorites that constitute the Greenschist Zone. At Tasiast, gold mineralisation has been defined over a strike length > 10 km and to vertical depths of 740 m. All of the significant mineralised bodies defined to date dip moderately to steeply (45° to 70°) to the east and have a south–southeasterly plunge. Gold deposits on the Tasiast trend are associated with second order shear zones that are splays cutting the hanging wall block of the Tasiast thrust. An age of 2839 ± 36 Ma obtained from the hydrothermal overgrowth on zircons from a quartz vein is interpreted to represent the age of mineralisation. [ABSTRACT FROM AUTHOR]

This paper presents the performance evaluation and analysis of the first large-scale solar photovoltaic plant in Mauritania. The plant has a total capacity of 15 MW p and was installed in Nouakchott. The plant is composed of seventeen arrays connected to inverters and the energy delivered is supplied to the 33 kV electricity grid through nine transformers. Monitoring data from the photovoltaic plant was used to evaluate performance indices such as reference yield, array yield, system yield, DC performance ratio, capacity factor, array capture losses, miscellaneous capture losses and thermal capture losses. The comparison between the performances of two photovoltaic arrays of the photovoltaic plant was performed and the results of this study were compared with other systems installed in other countries. The results show that the photovoltaic plant performances depend on both insolation and environmental conditions. Comparison results show that performance may be different from one array to another from the PV plant. In addition, the analysis shows that the Sheikh Zayed plant exhibit high losses compared to other photovoltaic systems installed in other locations. [ABSTRACT FROM AUTHOR]

This is the first study to provide age estimations of the two black hake species living in Mauritanian waters. Here we propose a new interpretation of microstructural growth increments that are assumed to be deposited daily. Our approach to age-reading combining the counts in both sagittal and transverse planes proved successful with black hake otoliths, including adults’. A newly developed image analysis software tool (OTOLab) was used to help in identifying and marking daily growth increments throughout the otoliths. Larval growth was analyzed from otolith sagittal sections and showed wider mean daily increments in Merluccius polli (3.32 μ) than in Merluccius senegalensis (2.85 μ). Conversely, once recruited to demersal life after metamorphosis, juvenile and adult growth was analyzed from otolith transverse sections, where the widest mean daily increments were found in M. senegalensis (4.19 μ) ( M. polli , 3.19 μ). Although the growth models of both species were not statistically different, the two black hakes probably have alternate growth strategies and, like the European hake, belong to the group of fast-growing hakes. When both species were considered together, the mean length of one-year-old black hakes was 36.7 cm, while the averaged individual growth rate was 1.12 mm day −1 . These growth values are the highest found for any hake species and are probably explained by the influence of one of the world’s most important upwelling systems, off northwest Africa. Although environmental factors may influence individual growth, ontogeny is the main factor determining growth rates at any life stage. Our results support otolith microstructural analysis as a realistic choice to regularly age hakes. [ABSTRACT FROM AUTHOR]

In March 2013, EDTA-blood and serum samples were collected from 119 cattle and 159 dromedaries at the slaughterhouse of Nouakchott, the capital city of the Islamic Republic of Mauritania. Serum samples were screened for the presence of Bluetongue (BT) antibodies by competitive ELISA (cELISA). Positive samples were then tested by serum-neutralization (SN) to determine BTV serotype. RNA from blood samples was first tested by a genus-specific quantitative RT-PCR assay which is able to detect all 27 existing BTV serotypes (RT-qPCR 1–27 ). Positive samples were further screened by a RT-qPCR assay which, instead, is able to detect the classical 24 BTV serotypes only (RT-qPCR 1–24 ). Of the 278 serum samples tested, 177 (mean = 63.7%; 95% CI: 57.9%–69.1%) resulted positive by cELISA. Of these, 69 were from cattle (mean = 58.0%; 95% CI: 49.0%–66.5%) and 108 from dromedaries (mean = 67.9%; 95% CI: 60.3%–74.7%). BTV-26 neutralizing antibodies were by far the most frequently found as they were detected in 146 animals with titres ranging from 1:10 to 1:80. Out of 278 blood samples, 25 (mean = 9.0%; 95% CI: 6.2%–12.9%) were found positive for BTV by RT-qPCR 1–27 , 20 (mean = 16.8%; 95% CI: 11.2%–24.6%) were from cattle and 5 (mean = 3.1%; 95% CI: 1.4%–7.1%) from dromedaries. When tested by RT-qPCR 1–24 the 25 BTV positive samples were negative. Unfortunately, no genetic information by molecular typing or by next generation sequencing has been obtained as for the very low levels of RNA in the blood samples. [ABSTRACT FROM AUTHOR]

The Gara Djebilet iron ore region is one of the most important regions in Africa. Located in the southwestern part of Algeria at the border with Mauritania, the Gara Djebilet region is characterized by steep terrain, which makes this area not easily accessible. Due to these conditions, remote sensing techniques and geophysics are the best ways to map this iron ore. The Gara Djebilet formations are characterized by high iron content that is especially rich in hematite, chamosite and goethite. The high iron content causes an absorption band at 0.88 μm, which is referred to as band 5 in the Operational Land Imager (OLI) Landsat 8 images. In this study, we integrated geological data, aerogravity data, and remote sensing data for the purpose of mapping the distribution of the Gara Djebilet iron deposit. Several remote sensing treatments were applied to the Landsat 8 OLI image, such as color composites, band ratioing, principal component analysis and a mathematical index, which helped locate the surface distribution of the iron ore. The results from gravity gradient interpretation techniques, 2-D forward modeling and 3-D inversion of aerogravity data provided information about the 2-D and 3-D distribution of the iron deposit. The combination of remote sensing and gravity results help us evaluate the ore potential of Gara Djebilet. The estimated tonnage of the iron ore at Gara Djebilet is approximately 2.37 billion tonnes with 57% Fe. [ABSTRACT FROM AUTHOR]

Reliable epidemiological data based on laboratory-confirmed cases are scarce in Mauritania. A large majority of reported malaria cases are based on presumptive clinical diagnosis. The present study was conducted to establish a reliable database on malaria morbidity among febrile paediatric and adult patients consulting spontaneously at public health facilities in Nouakchott, situated in the Saharan zone, and in Hodh Elgharbi region in the Sahelian zone in south-east Mauritania during the peak transmission periods. Giemsa-stained thin and thick films were examined under the microscope, and the parasite density was determined according to the procedures recommended by the World Health Organization. Microscopy results were confirmed by rapid diagnostic test for malaria. A total of 1161 febrile patients (498 in Nouakchott and 663 in Hodh Elgharbi region) were enrolled during two successive peak transmission periods in 2009 and 2010. In Nouakchott, 253 (50.8%) febrile patients had positive smears (83% Plasmodium vivax monoinfections and 17% Plasmodium falciparum monoinfections). In Hodh Elgharbi, 378 of 663 patients (57.0%) were smear-positive, mostly due to P. falciparum monoinfections (96.6%). Unlike in Nouakchott, mixed P. falciparum – P. vivax infections, as well as P. vivax , P. ovale , and P. malariae monoinfections, were also observed at a very low prevalence in southern Mauritania. In Nouakchott, malaria occurred more frequently ( P < 0.05) with higher slide positivity rates (42–53%) among children aged >5 years old and adults than in young children aged <5 years old in both 2009 and 2010. In Hodh Elgharbi, high slide positivity rates (60.9–86.2%) were observed in all age groups in 2010, and there was no significant trend ( P > 0.05) in relation with age groups. The present study confirmed the predominance of P. falciparum in southern Mauritania reported in previous studies. The presence of P. vivax in Nouakchott is a new epidemiological reality that requires an urgent adoption of novel strategies for parasitological and vector control to combat urban malaria. Moreover, the present study provides evidence-based data on malaria burden in two regions in Mauritania that may serve as a springboard to establish and develop a national surveillance system of malaria epidemiology. [ABSTRACT FROM AUTHOR]

We apply a mean-field model of interactions between migrating barchan dunes, the CAFE model, which includes spontaneous calving, aggregation, fragmentation, and mass-exchange, yielding a steady-state size distribution that can be resolved for different choices of interaction parameters. The CAFE model is applied to empirically measured distributions of dune sizes in two barchan swarms in the north circumpolar region of Mars, three swarms in Morocco, and one in Mauritania, each containing more than 1000 bedforms. When the sizes of bedforms are rescaled by the mean size in each zone two attractor states appear, with the Tarfaya zones all displaying a common distribution and the Martian and Mauritanian zones sharing a different distribution. Comparison of these attractor states with the outputs of the CAFE model reveals that the Tarfaya-type distribution results from a preference for aggregation and fragmentation interactions whereas the Mars–Mauritania distribution is more likely a result of exchange–dominated interactions. We observe that there appears to be a greater number of collisions happening in Tarfaya than in the other areas which is consistent with a greater rate of aggregation–fragmentation processes as suggested by our model. Our comparison with the CAFE model also predicts a universal rule for the outputs of the different types of interactions with exchange interactions favouring the production of two dunes roughly equal in size. Fragmentation interactions often result in three bedforms with volumes approximately in the ratio 1:1:2. Finally, we find that spontaneous calving of dunes does not play an important role in shaping the size distributions in barchan swarms. • Barchan swarm characteristics show similarities between Mars and Earth. • CAFE model can infer interaction dynamics from real-world size distributions. • Wide distributions result from aggregation–fragmentation interactions. • Strongly peaked distributions result from conservative exchange interactions. • Spontaneous calving does not play a significant role in size selection. [ABSTRACT FROM AUTHOR]

Religious and cultural practices have major implications for a Country's economic performance. However, it is not clear if the formal institutionalization of these social norms within a country's legal system causes material economic effects. In this study I show this to be the case. By employing the synthetic control methodology to mitigate endogeneity concerns, I show that the institutionalization of Sharia Law within a Muslim-majority country's legal system causes material economic costs. Results hold in different settings, confirming that the governmental enforcement of existing social norms constrain individuals' social and economic freedom, ultimately resulting in worsened economic outcomes. • The adoption of Sharia Law in Mauritania resulted in material economic costs. • Institutionalizing religious practices causes lasting economic effects. • Formalizing social norms results in worsened economic outcomes. [ABSTRACT FROM AUTHOR]

This paper identifies the effect of Mauritian regulation changes on EU industrial vessels' fishing activities and their implications for food security. The rich resources of Mauritanian waters have historically been utilized by large foreign trawlers, creating small ripple effects and jobs in Mauritania. However, in 2012, Mauritanian authorities introduced new restrictive access conditions; a 20 nautical mile limit and an obligation to land fish caught in this area in Mauritania, so as the national fishing industry to play a more important role. This resulted in significant changes to vessel fishing strategies and distribution channels. For instance, EU vessels that had supplied markets in the Gulf of Guinea, providing a low-cost source of protein to populations, were now unable to exploit the important sardinella resources that migrate along the coast for such purposes. Instead, these resources are now harvested by Turkish coastal vessels, supplying a very recent large fishmeal and oil industry based in Mauritania. Large quantities of small pelagics have thus been redirected from being valuable food products to creating fishmeal aimed at non-human uses. Moreover, this change has put the small pelagics stocks under pressure and most species are currently overexploited. Mauritania, under its current 2021–25 policy, is presently implementing measures to develop a fish processing industry aimed at human consumption, to which European vessels can supply fish. Yet, further improvements are still required in the business environment, such as transparency, regulatory framework and fiscal issues, to enhance regional food security. [ABSTRACT FROM AUTHOR]

We compared particle data from a moored video camera system with sediment trap derived fluxes at ∼1100 m depth in the highly dynamic coastal upwelling system off Cape Blanc, Mauritania. Between spring 2008 and winter 2010 the trap collected settling particles in 9-day intervals, while the camera recorded in-situ particle abundance and size-distribution every third day. Particle fluxes were highly variable (40–1200 mg m −2 d −1 ) and followed distinct seasonal patterns with peaks during spring, summer and fall. The particle flux patterns from the sediment traps correlated to the total particle volume captured by the video camera, which ranged from1 to 22 mm 3 l −1 . The measured increase in total particle volume during periods of high mass flux appeared to be better related to increases in the particle concentrations, rather than to increased average particle size. We observed events that had similar particle fluxes, but showed clear differences in particle abundance and size-distribution, and vice versa. Such observations can only be explained by shifts in the composition of the settling material, with changes both in particle density and chemical composition. For example, the input of wind-blown dust from the Sahara during September 2009 led to the formation of high numbers of comparably small particles in the water column. This suggests that, besides seasonal changes, the composition of marine particles in one region underlies episodical changes. The time between the appearance of high dust concentrations in the atmosphere and the increase lithogenic flux in the 1100 m deep trap suggested an average settling rate of 200 m d −1 , indicating a close and fast coupling between dust input and sedimentation of the material. [ABSTRACT FROM AUTHOR]