Capturing flow transformation processes across an uneven seabed in coarse-grained sediment gravity flow deposits

The upper part of the Jurassic stratigraphy of the Los Molles Formation corresponds to deepwater succession deposited with a regional marine transgression during the early postrift stage of the Neuquén Basin. The present study conducted in the location of Chacay Melehue (Argentina) is used to document the interactions between coarse-grained sediment gravity flows and the depositional relief of a seismic-scale mass transport complex (MTC), with metre-scale mounds and decametric protruding clasts, as an analogue for similar configurations in subsurface systems. The 60 m thick succession is exposed along a 6.5 km long oblique downdip longitudinal profile. Exposure quality permits walking out of individual beds. A total of 16 stratigraphic sections (1560 m thick) spaced between 500 m and 100 m, were logged at 1:50 and 1:25 scale. The basal datum of the studied interval is the top of a MTC and the top marker bed is an extensive sandstone bed. Two units studied correspond to very coarse to fine-grained medium-bedded sandstones with abundant pebble-sized clasts (Unit1) and three thick plurimetric distinct beds of poorly-sorted, granular to medium-grained mud-rich sandstone matrix supporting polygenic gravels (Unit2). Distinct thick extensive beds in both units are intercalated with heterolithic successions of thin to medium-bedded very coarse- to coarse-grained or fine-grained sandstones, siltstones and mudstones. The sandstone beds in Unit 1 abruptly pinchout in the proximal part of study area. They are associated with evidence of erosion, sediment bypass and transformation of subaqueous sand-bearing flows. Stratigraphically, sandstone packages in the Unit 2 are increasingly more laterally extensive upwards in the succession. Thickness variations in these beds are related to compensational stacking. The research will inform studies in the architecture of deep-water successions above an uneven seabed inherited from the top of a MTC. The detailed analysis of exhumed examples that record depositional changes in the structure of the flow can lead to the development of predictive stratigraphic models which incorporate details and complexities observed in outcrop and can be applied for the evaluation of the quality of subsurface reservoirs.Fil: Privat, Aurélia. University of Leeds; Reino UnidoFil: Hodgson, David. University of Leeds; Reino UnidoFil: Peakall, Jeffrey. University of Leeds; Reino UnidoFil: Jackson, Christopher A. L.. University of Leeds; Reino UnidoFil: Schwarz, Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina2016 AAPG/SEG International Convention and ExhibitionBarcelonaEspañaAmerican Association of Petroleum GeologistsSociety of Exploration Geophysicist

Les lésions médullaires traumatiques : épidémiologie et perspectives

AbstractObjectiveSpecify the epidemiological data on the acute spinal cord injuries and define a group of patients that could benefit from cellular transplantation therapy designed with the aim of repair and regeneration of damaged spinal cord tissues.Material and methodsFive years monocentric (Gui-de-Chauliac Hospital, Montpellier, France) retrospective analysis of patients suffering from spinal cord injury (SCI). Spinal cord injured-patients, defined as sensory-motor complete, underwent a clinical evaluation following American Spinal Injury Association (ASIA) and functional type 2 Spinal Cord Independence Measure (SCIM2) scorings as well as radiological evaluation through spinal cord magnetic resonance imaging (MRI).ResultsOne hundred and fifty-seven medical records were reviewed and we selected and re-examined 20 patients with complete thoracic spinal cord lesion. Clinical and radiological evaluations of these patients demonstrated, in 75 % of the cases, an absence of clinical progression after a mean of 49months. Radiological abnormalities were constantly present in the initial (at the admission to hospital) and control (re-evaluation) MRI and no reliable predictive criteria of prognosis had been found.Discussion/ConclusionWe compare our results to the literature and discuss advantages and limits of cellular transplantation strategies for these patients.RésuméObjectifsConnaître les données épidémiologiques de notre région sanitaire sur les traumatismes médullaires. Au sein de cette population, sélectionner les patients susceptibles de bénéficier de thérapie cellulaire dans la moelle épinière lésée dans l’objectif de régénérer le tissu nerveux. Évaluer à distance ces patients.Patients et méthodeAnalyse rétrospective de tous les patients pris en charge pour un traumatisme vertébro-médullaire. Réévaluation clinique et radiologique des patients présentant une atteinte médullaire thoracique sensitivomotrice complète. Réévaluation réalisée par le score de l’American Spinal Injury Association (ASIA), le score fonctionnel Type 2 Spinal Cord Independence Measure (SCIM2) et contrôle radiologique par une IRM médullaire.RésultatsCent cinquante-sept dossiers de patients ont été analysés et 28 patients présentaient une lésion médullaire complète. Une évaluation clinique et radiologique réalisée chez 20 patients sur 28 (71 %) a montré l’absence d’évolution clinique dans 75 % des cas dans un délai moyen de 49 mois. Les anomalies radiologiques étaient présentes dans 100 % des cas sur l’IRM initiale et de contrôle sans qu’aucun critère fiable prédictif de bon pronostic n’est retrouvé.Discussion/conclusionNous présentons ces résultats comparativement à ceux de la littérature et nous discutons chez ces malades les stratégies de transplantation cellulaire, leurs limites actuelles et les progrès nécessaires pour obtenir des résultats

Not all features are created equal: Processing asymmetries between location and object features

Previous research has shown spontaneous location processing when location is not a task relevant feature and when a target is presented together with distractors. The present study investigates whether such processing can occur in the absence of distractor inhibition, and whether there is a processing asymmetry between location and an object feature. The results show that not all features are created equal. Whereas attending to an object’s color or texture led to the involuntary processing of that object’s location, attending to an object’s location did not necessarily result in the encoding of its color or texture when these nonspatial properties were not task relevant. These results add to the body of evidence demonstrating the special role of location in attentional selection. They also provide a clearer picture of the interactions among location, object features, and participants’ behavioral goals

Anatomy of an exhumed debrite and impact on stratal architecture

Submarine debrites generate complicated patterns of seabed relief which in uence subsequent ow behaviour and depositional patterns. However, recognizing this interaction in subsurface data is challenging in seismic and well data. To bridge this resolution gap, large-scale outcrop analogues can be used. The early post-rift Middle Jurassic succession of the Los Molles Formation is well-exposed along a 10 km long and downdip-orientated W-E outcrop belt located the western Central Neuquen Basin, Argentina.Fil: Martanez Donate, Ander. University of Manchester; Reino UnidoFil: Privat, Aurelia. University of Leeds; Reino UnidoFil: Spychala, Yvonne. Leibniz Universitat Hannover; AlemaniaFil: Hodgson, David. University of Leeds; Reino UnidoFil: Jackson, Christopher A. L.. Imperial College London; Reino UnidoFil: Kane, Ian. University of Manchester; Reino UnidoFil: Schwarz, Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Flint, Stephen S.. University of Manchester; Reino Unido59th British Sedimentological Research Group Annual General MeetingLiverpoolReino UnidoBritish Sedimentological Research GroupUniversity of Liverpoo

Tb or not Tb: Banding in Turbidite Sandstones

Recognition and interpretation of sedimentary structures is fundamental to understanding sedimentary processes. Banded sandstones are an enigmatic sedimentary facies comprising alternating mud-rich (as matrix and/or mud clasts) and cleaner sand layers. The juxtaposition of hydrodynamically different grain sizes contradicts established models of cleaner-sand bedform development. Here, outcrop, subsurface core, and petrographic data from three deep-water systems, with well-constrained paleogeographic contexts, are used to describe the range of sedimentary textures, bedform morphologies, and facies associations, and to quantify the mud content of banding. Banding can occur in any part of a bed (base, middle, or top), but it typically overlies a structureless basal sandstone or mud-clast conglomerate lag, and is overlain by clean parallel-laminated sandstone and/or ripple cross-lamination. Banding morphology ranges from sub-parallel to bedforms that comprise low-angle laminae with discontinuous lenses of mudstone, or asymmetric bedforms comprising steeply dipping foresets that transition downstream into low-amplitude bedwaves, or steeply dipping ripple-like bedforms with heterolithic foresets. This style of banding is interpreted as a range of bedforms that form progressively in the upper-stage plane-bed flow regime via tractional reworking beneath mud-laden transitional plug flows. The balance of cohesive and turbulent forces, and the rate of flow deceleration (aggradation rate), govern the style of deposit. Banded sandstones and linked debrites are rarely found juxtaposed together in the same bed because they are distributed preferentially in proximal and distal settings, respectively. Understanding the origins of banding in turbidite sandstones, the conditions under which it forms, and its distribution across deep-water systems and relationship to linked debrites, is important for it to be used effectively as a tool to interpret the geological record

Anatomical study of serotonergic innervation and 5-HT1A receptor in the human spinal cord

Serotonergic innervation of the spinal cord in mammals has multiple roles in the control of motor, sensory and visceral functions. In rats, functional consequences of spinal cord injury at thoracic level can be improved by a substitutive transplantation of serotonin (5-HT) neurons or regeneration under the trophic influence of grafted stem cells. Translation to either pharmacological and/or cellular therapies in humans requires the mapping of the spinal cord 5-HT innervation and its receptors to determine their involvement in specific functions. Here, we have performed a preliminary mapping of serotonergic processes and serotonin-lA (5-HT1A) receptors in thoracic and lumbar segments of the human spinal cord. As in rodents and non-human primates, 5-HT profiles in human spinal cord are present in the ventral horn, surrounding motoneurons, and also contact their presumptive dendrites at lumbar level. 5-HT1A receptors are present in the same area, but are more densely expressed at lumbar level. 5-HT profiles are also present in the intermediolateral region, where 5-HT1A receptors are absent. Finally, we observed numerous serotonergic profiles in the superficial part (equivalent of Rexed lamina II) of the dorsal horn, which also displayed high levels of 5-HT1A receptors. These findings pave the way for local specific therapies involving cellular and/or pharmacological tools targeting the serotonergic system

Illegals abortions and utero-digestives lesions: retrospective study of 12 cases in the Department of Gynecology and Obstetrics at the Treichville teaching hospital (Abidjan, Cote D’ivoire)

Background: Traumatic intestinal digestive damage after abortion by endo-uterine manoeuvres are not uncommon. The purpose of this study is to describe the diagnostic, therapeutic and prognostic aspects of these lesions.Methods: This is a retrospective study of 3 years on patients with a uterine lesion associated with a digestive traumatic injury during illegal abortions endo-uterine manoeuvres.Results: 12 patients with a median age of 23, 9 are included. The clinical manifestations are not specific: impairment of the general condition 33.3%; hyperthermia 83.3% (or 10 cases); digestive disorders such as diarrhoea 25%, vomiting 33.3%; abdominal pain 100%; occlusive syndrome 16.7%; acute abdominal syndrome 75%. The seat of traumatic injuries is variable. The lesions were for hail alone in 4 cases (33.3%), colon alone for 2 cases (16.7%), rectum 1 case and epiploon 2 cases. In these 3 cases, the lesions were associated, sitting on both the hail and the colon at a time. All these lesions were associated with uterine perforation of variable siege. The therapeutic management consisted of a small bowel resection with ileostomy in 5 cases or 41.7%; colon resection with colostomy 3 cases or 25%; suture lesions after beveling beiges 5 cases either 41, 7 in 2 cases, we performed haemostasis on the bleeding epiploon. Treatment of the uterine lesion was conservative 75% of the time. The evolution on the 10 patients was favorable, 83.3%. Two patients died early in the operative course after septic shock.Conclusions: The digestive lesions are a factor aggravating the prognosis of post-abortion uterine manoeuvres. Their management must be rapid and requires close collaboration between the digestive surgeon and the Gynecologist

Influence of particle composition and thermal cycling on bijel formation

Colloidal particles with appropriate wetting properties can become very strongly trapped at an interface between two immiscible fluids. We have harnessed this phenomenon to create a new class of soft materials with intriguing and potentially useful characteristics. The material is known as a bijel: bicontinuous interfacially-jammed emulsion gel. It is a colloid-stabilized emulsion with fluid-bicontinuous domains. The potential to create these gels was first predicted using computer simulations. Experimentally we use mixtures of water and 2,6-lutidine at the composition for which the system undergoes a critical demixing transition on warming. Colloidal silica, with appropriate surface chemistry, is dispersed while the system is in the single-fluid phase; the composite sample is then slowly warmed well beyond the critical temperature. The liquids phase separate via spinodal decomposition and the particles become swept up on the newly created interfaces. As the domains coarsen the interfacial area decreases and the particles eventually become jammed together. The resulting structures have a significant yield stress and are stable for many months. Here we begin to explore the complex wetting properties of fluorescently-tagged silica surfaces in water-lutidine mixtures, showing how they can be tuned to allow bijel creation. Additionally we demonstrate how the particle properties change with time while they are immersed in the solvents.Comment: Proceedings of the 7th Liquid Matter Conference, held in Lund (Sweden) in June 200

Mechanisms of base selection by human single-stranded selective monofunctional uracil-DNA glycosylase

hSMUG1 (human single-stranded selective monofunctional uracil-DNA glyscosylase) is one of three glycosylases encoded within a small region of human chromosome 12. Those three glycosylases, UNG (uracil-DNA glycosylase), TDG (thymine-DNA glyscosylase), and hSMUG1, have in common the capacity to remove uracil from DNA. However, these glycosylases also repair other lesions and have distinct substrate preferences, indicating that they have potentially redundant but not overlapping physiological roles. The mechanisms by which these glycosylases locate and selectively remove target lesions are not well understood. In addition to uracil, hSMUG1 has been shown to remove some oxidized pyrimidines, suggesting a role in the repair of DNA oxidation damage. In this paper, we describe experiments in which a series of oligonucleotides containing purine and pyrimidine analogs have been used to probe mechanisms by which hSMUG1 distinguishes potential substrates. Our results indicate that the preference of hSMUG1 for mispaired uracil over uracil paired with adenine is best explained by the reduced stability of a duplex containing a mispair, consistent with previous reports with Escherichia coli mispaired uracil-DNA glycosylase. We have also extended the substrate range of hSMUG1 to include 5-carboxyuracil, the last in the series of damage products from thymine methyl group oxidation. The properties used by hSMUG1 to select damaged pyrimidines include the size and free energy of solvation of the 5-substituent but not electronic inductive properties. The observed distinct mechanisms of base selection demonstrated for members of the uracil glycosylase family help explain how considerable diversity in chemical lesion repair can be achieved