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While he is mentioned as bishop of Maastricht between the late 6th century and the beginning of the 7th century by the medieval Liège chronicles, starting with the Gesta episcoporum written by Hériger de Lobbes (ca 980), Perpète, whose relics are preserved today in the collegiate church of Ste-Marie-et-St-Perpète in Dinant (prov. Namur), was excluded from the critical list of the bishops of Tongres-Maastricht- Liège. However, a rereading of the written sources mentioning him and the recent contribution of archaeometry and paleoanthropology invite us to rehabilitate Perpète as bishop, as a historical figure, and no longer only as an object of veneration. His burial in Dinant, a small agglomeration in the Mosan basin, is in keeping with the practice of the bishops of Tongeren-Maastricht who focused their efforts at Christianisation in the most dynamic communities of their diocese during the Merovingian era. This burial, in the St-Vincent church as reported by Gilles d'Orval’s Gesta episcoporum around 1250, and the spread of the cult of this saint from Saragossa in the north of Gaul plead in favour of the existence of this church —at the latest in ca 600. The transfer of the relics of St. Perpète to the church of Ste-Marie in Dinant took place at the latest in 1096, when it had the double dedication of Ste-Marie-et- St-Perpète. It’s probably part of the programme of assertion of power of the bishops of Liège in Dinant between the late 10th century and the late 11th century. Alors qu’il est mentionné comme évêque de Maastricht entre la fin du 6e et le début du 7e s. par les grandes chroniques liégeoises médiévales, à commencer par les Gesta episcoporum d’Hériger de Lobbes en ca 980, Perpète, dont les reliques sont conservées aujourd’hui en la collégiale Ste-Marie-et-St-Perpète de Dinant (prov. Namur), a été exclu de la liste critique des évêques de Tongres-Maastricht-Liège. Or une relecture des sources écrites le mentionnant et l’apport récent de l’archéométrie et de la paléoanthropologie invitent à réhabiliter Perpète comme évêque, comme personnage historique, et non plus seulement comme objet de vénération. Son inhumation à Dinant, agglomération du bassin mosan, s’inscrit dans la pratique des évêques de Tongres-Maastricht qui concentraient leurs efforts de christianisation dans les communautés les plus dynamiques du diocèse à l’époque mérovingienne. Cette inhumation, en l’église St-Vincent comme le rapportent les Gesta episcoporum de Gilles d’Orval vers 1250, et la diffusion du culte de ce saint saragossais dans le nord de la Gaule plaident en faveur de l’existence de cette église au plus tard en ca 600. Le transfert des reliques de S. Perpète vers l’église Ste-Marie de Dinant eut lieu au plus tard en 1096, lorsque celle-ci portait la double dédicace Ste-Marie-et-St-Perpète, et s’inscrit probablement dans le programme d’affirmation du pouvoir des évêques de Liège à Dinant entre la fin du 10e s. et la fin du 11e s. Perpète, dessen Reliquien heute in der Stiftskirche Ste-Marie-et-St-Perpète in Dinant (Provinz Namur) aufbewahrt werden, wird von den mittelalterlichen Lütticher Chroniken, beginnend mit der Gesta episcoporum von Hériger de Lobbes um 980, als Bischof von Maastricht zwischen Ende des 6. Jahrhunderts und Anfang des 7. Jahrhunderts erwähnt. Trotzdem wurde er von der kritischen Liste der Bischöfe von Tongern-Maastricht-Lüttich ausgeschlossen. Ein erneutes Lesen der schriftlichen Quellen, in denen er erwähnt wird, und der jüngste Beitrag der Archäometrie und Paläoanthropologie laden uns jedoch ein, Perpète als Bischof, als historische Figur und nicht mehr nur als Gegenstand der Verehrung, zu rehabilitieren. Seine Beerdigung in Dinant, einer Ansiedlung im Mosan-Becken, entspricht der Praxis der Bischöfe von Tongern-Maastricht, die sich während der Merowingerzeit auf die Christianisierung in den dynamischsten Gemeinden der Diözese konzentrierten. Diese Beerdigung in der Saint-Vincent-Kirche, wie sie von Gilles d’Orvals Gesta episcoporum um 1250 berichtet wurde, und die Verbreitung des Kultes dieses Heiligen aus Saragossa im Norden Galliens sprechen für die Existenz dieser Kirche spätestens um. 600. Die Übergabe der Reliquien des Heiligen Perpète an die Kirche Ste-Marie in Dinant erfolgte spätestens 1096, als sie die doppelte Widmung von Ste-Marie-et-St-Perpète trug. Sie ist wahrscheinlich Teil des Programms der Machtübernahme der Bischöfe von Lüttich in Dinant zwischen dem Ende des 10. Jahrhunderts und dem Ende des 11. Jahrhunderts.

En Belgique, les restes humains datés de la période gallo-romaine restent peu étudiés par rapport aux époques plus récentes. Cela s’explique notamment par la pratique de l’incinération qui est majoritaire à cette période ainsi que par le peu de nécropoles découvertes dans nos régions, en particulier celles comportant des sépultures à inhumation. À travers cette étude, nous avons étudié les ossements humains de 56 individus principalement issus de la nécropole principale de l’importante ville de Tongres (province de Limbourg, Flandre, Belgique). L’espace funéraire fut utilisé du Ier au IVe siècle bien que l’inhumation concerne majoritairement le IIIe et le IVe siècle. Le but de notre approche était de proposer une caractérisation de la population (sexe, âge, stature) ainsi qu’une large étude paléopathologique (pathologies dentaires, infections, fractures, marqueurs de stress non-spécifiques, modifications dégénératives des articulations ainsi que de nombreux cas pathologiques individuels). Les nombreuses observations réalisées ont été confrontées entre elles mais aussi avec des données contextuelles connues telles que le type de tombe, la répartition spatiale, la datation et les résultats de sites similaires. Ce qui nous a permis de distinguer des tendances intéressantes au sein de la population ainsi que des différences en fonction du groupe social. La présente étude a permis de mieux connaître la population de Tongres, l’une des cités antiques gallo-romaines les plus importantes de Belgique, ainsi que les nombreuses pathologies et stress auxquels elle était soumise. Mais également de comprendre leur répartition au sein de l’espace et de la vie sociale et proposer de nombreuses perspectives.

En 1964, un groupe de spéléologues amateurs de Villers-la-Ville, appelé "Vampire", fouille une cavité dans les Rochers de Freyr situés dans la Province de Namur (Belgique). Les vestiges exhumés sont actuellement conservés au Musée régional d’Histoire naturelle de Mons. Le matériel archéologique est pauvre et composé principalement d’éclats de silex. Il est difficilement datable sans contexte, ni documentation précise. Notre inventaire recense 557 restes humains et 151 restes fauniques. L’étude préliminaire de la faune indique principalement une accumulation de proies par des carnivores et la présence d’animaux fouisseurs. Aucune trace de feu ou de boucherie n’a été notée. L’étude anthropologique montre que, comme dans les nombreuses autres sépultures collectives du Bassin mosan, les squelettes humains sont incomplets et les os fragmentés. Elle révèle qu’au moins six (voire sept) individus ont été placés dans cette grotte. Trois d’entre eux ont été datés au radiocarbone et remontent au Néolithique Récent. Le résultat le plus surprenant est qu’il s’agit uniquement de sujets immatures (ce qui expliquerait le nom donné à la grotte). Le plus jeune serait décédé entre 1 et 3 ans et le plus âgé est un adolescent. C’est à ce dernier qu’appartiendrait le seul crâne conservé. Afin de représenter l’état de conservation de chaque os de cette sépulture collective, nous avons créé des fiches spécifiques aux individus immatures qui pourront être utiles à tous ceux qui étudient des ensembles funéraires rassemblant de nombreux non-adultes. Aucune trace de pathologies graves n’a été relevée mais tous les tibias présentaient des lignes de Harris et 17 % des dents isolées étaient atteintes d’hypoplasie de l’émail dentaire. On dénombre également un cas de spina bifida atlantis. Parmi les particularités anatomiques, signalons une perforation olécranienne de l’humérus, une incisive en forme de pelle et une fosse d’Allen sur un des fémurs.

El presente artículo proporciona información sobre los resultados preliminares de la 14ª campaña de excavación arqueológica del Proyecto Qubbet el-Hawa de la Universidad de Jaén. Desde hace más de una década, el proyecto desarrolla su investigación en la necrópolis más meridional de Egipto. Consideramos importante destacar las nuevas incorporaciones al equipo interdisciplinar que han permitido, entre otros avances, el estudio de las momias de cocodrilos halladas con anterioridad o el descubrimiento de una mina de época bizantina. Sin embargo, también es destacable la continuación de otros estudios ya iniciados en anteriores campañas e incluso la finalización de los trabajos arqueológicos en diferentes áreas de la colina. Sin duda, y como cada año, el Proyecto Qubbet el-Hawa puede congratularse de la realización de una campaña exitosa, llena de resultados muy relevantes para la investigación.

Electro-active sediments distinguish themselves from other sedimentary environments by the presence of microbially induced electrical currents in the surface layer of the sediment. The electron transport is generated by metabolic activity of long filamentous cable bacteria, in a process referred to as electrogenic sulfur oxidation (e-SOx). Laboratory experiments have shown that e-SOx exerts a large impact on the sediment geochemistry, but its influence on the in situ geochemistry of marine sediments has not been previously investigated. Here, we document the biogeochemical cycling associated with e-SOx in a cohesive coastal sediment in the North Sea (Station 130, Belgian Coastal Zone) during three campaigns (January, March and May 2014). Fluorescence in situ hybridization showed that cable bacteria were present in high densities throughout the sampling period, and that filaments penetrated up to 7 cm deep in the sediment, which is substantially deeper than previously recorded. High resolution microsensor profiling (pH, H2S and O2) revealed the typical geochemical fingerprint of e-SOx, with a wide separation (up to 4.8 cm) between the depth of oxygen penetration and the depth of sulfide appearance. The metabolic activity of cable bacteria induced a current density of 25–32 mA m-2 and created an electrical field of 12–17 mV m-1 in the upper centimeters of the sediment. This electrical field created an ionic drift, which strongly affected the depth profiles and fluxes of major cations (Ca2+, Fe2+) and anions (SO42-) in the pore water. The strong acidification of the pore water at depth resulted in the dissolution of calcium carbonates and iron sulfides, thus leading to a strong accumulation of iron, calcium and manganese in the pore water. While sulfate accumulated in the upper centimeters, no significant effect of e-SOx was found on ammonium, phosphate and silicate depth profiles. Overall, our results demonstrate that cable bacteria can strongly modulate the sedimentary biogeochemical cycling under in situ conditions

The geochemical cycles of iron and sulphur in marine sediments are strongly intertwined and give rise to a complex network of redox and precipitation reactions. Bioturbation refers to all modes of transport of particles and solutes induced by larger organisms, and in the present-day seafloor, bioturbation is one of the most important factors controlling the biogeochemical cycling of iron and sulphur. To better understand how bioturbation controls Fe and S cycling, we developed reactive transport model of a coastal sediment impacted by faunal activity. Subsequently, we performed a model sensitivity analysis, separately investigating the two different transport modes of bioturbation, i.e. bio-mixing (solid particle transport) and bio-irrigation (enhanced solute transport). This analysis reveals that bio-mixing and bio-irrigation have distinct—and largely opposing effects on both the iron and sulphur cycles. Bio-mixing enhances transport between the oxic and suboxic zones, thus promoting the reduction of oxidised species (e.g. iron oxyhydroxides) and the oxidation of reduced species (e.g. iron sulphides). Through the reoxidation of iron sulphides, bio-mixing strongly enhances the recycling of Fe and S between their reduced and oxidised states. Bio-irrigation on the other hand removes reduced solutes, i.e. ferrous iron and free sulphide, from the sediment pore water. These reduced species are then reoxidised in the overlying water and not recycled within the sediment column, which leads to a decrease in Fe and S recycling. Overall, our results demonstrate that the ecology of the macrofauna (inducing bio-mixing or bio-irrigation, or both) matters when assessing their impact on sediment geochemistry. This finding seems particularly relevant for sedimentary cycling across Cambrian transition, when benthic fauna started colonizing and reworking the seafloor.

At the end of 2014, a Major Baltic Inflow (MBI) brought oxygenated, salty water into the Baltic proper and reached the long-term anoxic Eastern Gotland Basin (EGB) by March 2015. In July 2015, we measured benthic fluxes of phosphorus (P), nitrogen (N) and silicon (Si) nutrients and dissolved inorganic carbon (DIC) in situ using an autonomous benthic lander at deep sites (170–210 m) in the EGB, where the bottom water oxygen concentration was 30–45 μM. The same in situ methodology was used to measure benthic fluxes at the same sites in 2008–2010, but then under anoxic conditions. The high efflux of phosphate under anoxic conditions became lower upon oxygenation, and turned into an influx in about 50% of the flux measurements. The C:P and N:P ratios of the benthic solute flux changed from clearly below the Redfield ratio (on average about 70 and 3–4, respectively) under anoxia to approaching or being well above the Redfield ratio upon oxygenation. These observations demonstrate retention of P in newly oxygenated sediments. We found no significant effect of oxygenation on the benthic ammonium, silicate and DIC flux. We also measured benthic denitrification, anammox, and dissimilatory nitrate reduction to ammonium (DNRA) rates at the same sites using isotope-pairing techniques. The bottom water of the long-term anoxic EGB contained less than 0.5 μM nitrate in 2008–2010, but the oxygenation event created bottom water nitrate concentrations of about 10 μM in July 2015 and the benthic flux of nitrate was consistently directed into the sediment. Nitrate reduction to both dinitrogen gas (denitrification) and ammonium (DNRA) was initiated in the newly oxygenated sediments, while anammox activity was negligible. We estimated the influence of this oxygenation event on the magnitudes of the integrated benthic P flux (the internal P load) and the fixed N removal through benthic and pelagic denitrification by comparing with a hypothetical scenario without the MBI. Our calculations suggest that the oxygenation triggered by the MBI in July 2015, extrapolated to the basin-wide scale of the Baltic proper, decreased the internal P load by 23% and increased the total (benthic plus pelagic) denitrification by 18%.

The evolution of burrowing animals forms a defining event in the history of the Earth. It has been hypothesised that the expansion of seafloor burrowing during the Palaeozoic altered the biogeochemistry of the oceans and atmosphere. However, whilst potential impacts of bioturbation on the individual phosphorus, oxygen and sulphur cycles have been considered, combined effects have not been investigated, leading to major uncertainty over the timing and magnitude of the Earth system response to the evolution of bioturbation. Here we integrate the evolution of bioturbation into the COPSE model of global biogeochemical cycling, and compare quantitative model predictions to multiple geochemical proxies. Our results suggest that the advent of shallow burrowing in the early Cambrian contributed to a global low-oxygen state, which prevailed for ~100 million years. This impact of bioturbation on global biogeochemistry likely affected animal evolution through expanded ocean anoxia, high atmospheric CO2 levels and global warming.

The East Anglian salt marsh system (UK) has recently generated intriguing data with respect to sediment biogeochemistry. Neighbouring ponds in these salt marshes show two distinct regimes of redox cycling: the sediments are either iron-rich and bioturbated, or they are sulphide-rich and unbioturbated. No conclusive explanation has yet been given for this remarkable spatial co-occurrence. Here, we quantify the geochemical cycling in both pond types, using pore-water analyses and solid-phase speciation. Our results demonstrate that differences in solid-phase carbon and iron inputs are likely small between pond types, and so these cannot act as the direct driver of the observed redox dichotomy. Instead, our results suggest that the presence of bioturbation plays a key role in the transition from sulphur-dominated to iron-dominated sediments. The presence of burrowing fauna in marine sediments stimulates the mineralisation of organic matter, increases the iron cycling and limits the build-up of free sulphide. Overall, we propose that the observed dichotomy in pond geochemistry is due to alternative stable states, which result from non-linear interactions in the sedimentary iron and sulphur cycles that are amplified by bioturbation. This way, small differences in solid phase input can result in very different regimes of redox cycling due to positive feedbacks. This non-linearity in the iron and sulphur cycling could be an inherent feature of marine sediments, and hence, alternative stable states could be present in other systems.

Cable bacteria (Deltaproteobacteria, Desulfobulbaceae) are long filamentous sulfur-oxidizing bacteria that generate long-distance electric currents running through the bacterial filaments. This way, they couple the oxidation of sulfide in deeper sediment layers to the reduction of oxygen or nitrate near the sediment-water interface. Cable bacteria are found in a wide range of aquatic sediments, but an accurate procedure to assess their abundance is lacking. We developed a qPCR approach that quantifies cable bacteria in relation to other bacteria within the family Desulfobulbaceae. Primer sets targeting cable bacteria, Desulfobulbaceae and the total bacterial community were applied in qPCR with DNA extracted from marine sediment incubations. Amplicon sequencing of the 16S rRNA gene V4 region confirmed that cable bacteria were accurately enumerated by qPCR, and suggested novel diversity of cable bacteria. The conjoint quantification of current densities and cell densities revealed that individual filaments carry a mean current of ~110 pA and have a cell specific oxygen consumption rate of 69 fmol O2 cell-1 day-1. Overall, the qPCR method enables a better quantitative assessment of cable bacteria abundance, providing new metabolic insights at filament and cell level, and improving our understanding of the microbial ecology of electrogenic sediments.