Le site aurignacien de plein-air de Combemenue à Brignac-la-Plaine (Corrèze) : apport de la géochéologie et de l’étude de l’industrie lithique à la compréhension des processus taphonomiques

Le site paléolithique de Combemenue en Corrèze a livré un niveau d’occupation d’Aurignacien récent enfoui à faible profondeur, sur un replat près du sommet d’un versant. Le contexte de faible enfouissement laissant suspecter des perturbations significatives du niveau archéologique dues à une longue exposition aux agents naturels en surface ou en subsurface du sol, une étude taphonomique détaillée a été entreprise. Différents points ont été examinés : la distribution spatiale du matériel, la disposition des objets (fabrique), leur granulométrie, leur état de surface ainsi que les remontages. Les résultats obtenus ont été confrontés de manière à proposer un scénario qui rende compte au mieux de l’ensemble des observations faites sur le site. Cette étude indique que l’assemblage lithique originel a subi un appauvrissement sélectif en petits éléments sous l’action du ruissellement. Simultanément, il est possible qu’une partie du matériel de plus grande taille initialement présent ait été soustrait du site par les mécanismes sédimentaires. Ces modifications ont eu des répercussions sur la distribution spatiale des vestiges. Celle-ci se caractérise par une absence de concentration claire, tant lorsqu’on considère la répartition de l’ensemble du matériel que celle de catégories particulières d’objets. Une diffusion progressive des vestiges par le ruissellement ou les phénomènes périglaciaires rend bien compte des transformations observées. En revanche, les déplacements n’ont pas entraîné d’altération physique importante des pièces, dont la majorité ne porte pas de stigmate postérieur à sa production ou son utilisation par les Aurignaciens. Les transformations décrites ici pour le site de Combemenue sont probablement représentatives de celles subies par un grand nombre de sites paléolithiques localisés sur une pente négligeable dans un contexte géomorphologique peu favorable à un enfouissement rapide.An Upper Aurignacian level located on a hilltop flat surface has been found at Combemenue (Brignac-la-Plaine, Corrèze, France) during field surveys along the A89 highway. Geomorphological evidence, and particularly the shallow depth of the level, strongly suggests that it has undergone significant perturbation due to a long-lasting exposure to sedimentary and pedological processes at the soil surface or subsurface. Therefore, a detailed taphonomic study has been made to evaluate the impact of natural processes in site patterning. It involves examination of the spatial distribution of the artefacts, their orientation and dip (fabric), their size distribution, their alteration and refits. The results have been compared to the data derived from the techno-economical analysis. This study indicates that the lithic assemblage has undergone a selective impoverishment in small-sized artefacts as the result of surface wash. A part of the coarser artefacts may have been also removed from the site by the same processes. The lack of any clear artefact concentration indicates that the spatial distribution has been modified significantly. This can be adequately described by a model of progressive diffusion of the artefacts by surface wash or periglacial processes. By contrast, the movements did not provoke strong physical alteration of the pieces. The Combemenue site is thought to be representative of a number of palaeolithic sites located in similar geomorphological contexts, which are characterized by low sedimentation rates

A Design-for-Yield Algorithm to Assess and Improve the Structural and Energetic Robustness of Proteins and Drugs

Robustness is a property that pervades all aspects of nature. The ability of a system to adapt to perturbations due to internal and external agents, aging, wear, or to environmental changes is one of the driving forces of evolution. At the molecular level, understanding the robustness of a protein has a great impact on the in-silico design of polypeptide chains and drugs. The chance of computationally checking the ability of a protein to preserve its structure in the native state may lead to the design of new compounds that can work in a living cell more effectively. Inspired by the well known robustness analysis framework used in Electronic Design Automation, we introduce a formal definition of robustness for proteins and a dimensionless quantity, called yield, to quantify the robustness of a protein. Then, we introduce a new robustness-centered protein design algorithm called Design-For-Yield. The aim of the algorithm is to discover new conformations with a specific functionality and high yield values. We present extensive characterizations of the robustness properties of many peptides, proteins, and drugs. Finally, we apply the DFY algorithm on the Crambin protein (1CRN) and on the Oxicitin drug (DB00107). The obtained results confirm that the algorithm is able to discover a Crambin-like protein that is 23.61% more robust than the wild type. Concerning the Oxicitin drug a new protein sequence and the corresponding protein structure was discovered with an improved robustness of 3% at the global level. © 2009 Springer Berlin Heidelberg

Soft Fault Clustering in Analog Electronic Circuits with the Use of Self Organizing Neural Network

The paper presents a methodology for parametric fault clustering in analog electronic circuits with the use of a self-organizing artificial neural network. The method proposed here allows fast and efficient circuit diagnosis on the basis of time and/or frequency response which may lead to higher production yield. A self-organizing map (SOM) has been applied in order to cluster all circuit states into possible separate groups. So, it works as a feature selector and classifier. SOM can be fed by raw data (data comes from the time or frequency response) or some pre-processing is done at first. The author proposes conversion of a circuit response with the use of e.g. gradient and differentiation. The main goal of the SOM is to distribute all single faults on a two-dimensional map without state overlapping. The method is aimed for the development stage because the tolerances of elements are not taken into account, however single but parametric faults are considered. Efficiency analyses of fault clustering have been made on several examples e.g. a Sallen-Key BPF and an ECG amplifier. Testing procedure is performed in time and frequency domains for the Sallen-Key BPF with limited number of test points i.e. it is assumed that only input and output pins are available. A similar procedure has been applied to a real ECG amplifier in the frequency domain. Results prove a high efficiency in acceptable time which makes th

Urinary tract infections and multiple sclerosis: Recommendations from the French Multiple Sclerosis Society

International audienceObjectives: Establish recommendations for the management of UTIs in MS patients.Background: Urinary tract infections (UTIs) are common during multiple sclerosis (MS) and are one of the most common comorbidities potentially responsible for deaths from urinary sepsis.Methods: The recommendations attempt to answer three main questions about UTIs and MS. The French Group for Recommendations in MS (France4MS) did a systematic review of articles from PubMed and universities databases (01/1980-12/2019). The RAND/UCLA appropriateness method, which has been developed to synthesize the scientific literature and expert opinions on health care topics, was used for reaching a formal agreement. 26 MS experts worked on the full-text review and a group of 70 multidisciplinary health care specialists validated the final evaluation of summarized evidences.Results: UTIs are not associated with an increased risk of relapse and permanent worsening of disability. Only febrile UTIs worsen transient disability through the Uhthoff phenomenon. Some immunosuppressive treatments increase the risk of UTIs in MS patients and require special attention especially in case of hypogammaglobulinemia. Experts recommend to treat UTIs in patients with MS, according to recommendations of the general population. Prevention of recurrent UTIs requires stabilization of the neurogenic bladder. In some cases, weekly oral cycling antibiotics can be proposed after specialist advice. Asymptomatic bacteriuria should not be screened for or treated systematically except in special cases (pregnancy and invasive urological procedures).Conclusion: Physicians and patients should be aware of the updated recommendations for UTis and MS

Immunization and multiple sclerosis: Recommendations from the French Multiple Sclerosis Society

International audienceObjectives: To establish recommendations on immunization for patients with multiple sclerosis (MS).Background: Vaccines have been suspected in the past to trigger MS and relapses. With the extension of the immunoactive treatment arsenal, other concerns have been raised more recently about an increased risk of infection or a decreased effectiveness of immunization in immunosuppressed patients.Methods: The French Group for Recommendations into Multiple Sclerosis (France4MS) performed a systematic search of papers in Medline and other university databases (January 1975-June 2018). The RAND/UCLA appropriateness method was chosen to review the scientific literature and to formalize the degree of agreement among experts on 5 clinical questions related to immunization and MS. Readers from the steering committee conducted a systematic analysis, wrote a critical synthesis and prepared a list of proposals that were evaluated by a rating group of 28 MS experts. The final version of the recommendations was finally reviewed by a reading group of 110 health care professionals and classified as appropriate, inappropriate or uncertain.Results: Neurologists should verify the vaccination status as soon as MS is diagnosed and before disease-modifying treatments (DMTs) are introduced. The French vaccination schedule applies to MS patients and seasonal influenza vaccination is recommended. In the case of treatment-induced immunosuppression, MS patients should be informed about the risk of infection and the vaccination standards of the French High Council of Health should be applied. Live attenuated vaccines are contra-indicated in patients recently treated with immunosuppressive drugs, including corticosteroids; other vaccines can be proposed whatever the treatment, but their effectiveness may be partly reduced with some drugs.Conclusion: Physicians and patients should be aware of the updated recommendations for immunizations of patients with MS