Learning by stochastic serializations

Complex structures are typical in machine learning. Tailoring learning algorithms for every structure requires an effort that may be saved by defining a generic learning procedure adaptive to any complex structure. In this paper, we propose to map any complex structure onto a generic form, called serialization, over which we can apply any sequence-based density estimator. We then show how to transfer the learned density back onto the space of original structures. To expose the learning procedure to the structural particularities of the original structures, we take care that the serializations reflect accurately the structures' properties. Enumerating all serializations is infeasible. We propose an effective way to sample representative serializations from the complete set of serializations which preserves the statistics of the complete set. Our method is competitive or better than state of the art learning algorithms that have been specifically designed for given structures. In addition, since the serialization involves sampling from a combinatorial process it provides considerable protection from overfitting, which we clearly demonstrate on a number of experiments.Comment: Submission to NeurIPS 201

Simulations of hamstring lengthening surgery in crouch gait cerebral palsy

The 11th International Symposium on Adaptive Motion of Animals and Machines. Kobe University, Japan. 2023-06-06/09. Adaptive Motion of Animals and Machines Organizing Committee.Poster Session P4

Dual-task related gait changes after CSF tapping: a new way to identify idiopathic normal pressure hydrocephalus

BACKGROUND: Gait disturbances found in patients with idiopathic normal pressure hydrocephalus (iNPH) are unspecific to the diagnosis and commonly occur in neurodegenerative or vascular conditions (iNPH-like conditions). This current retrospective pre-post intervention study aims to determine whether changes in quantitative gait parameters during dual task condition differed between iNPH and iNPH-like conditions before and after cerebrospinal fluid (CSF) tapping. METHODS: 49 patients assessed before and after CSF tapping were included in this study (27 with iNPH and 22 with iNPH-like conditions). Gait analysis during single and dual task conditions (walking and backward counting) was performed before and after a CSF spinal tap of 40 ml. Gait parameters were compared between iNPH and iNPH-like conditions patients. Logistic regressions were used to examine the association between iNPH and gait parameters. RESULTS: Improvements of step width (−9.03 (20.75)% for iNPH group; +0.28 (21.76)% for iNPH-like conditions group), stride length (+7.82 (20.71)% for iNPH group; -0.62 (19.22)% for iNPH-like conditions group), walking speed (+12.20 (29.79)% for iNPH group; +2.38 (32.50)% for iNPH-like conditions group) and stance duration (−1.23 (4.03)% for iNPH group; +0.49 (5.12)% for iNPH-like conditions group) during dual task, after CSF spinal tapping, were significant in patients with iNPH compared to patients with iNPH-like conditions. No between group difference was observed for the single walking task evaluation. The multiple logistic regression revealed that among these four gait parameters, only the improvement in step width was associated with the diagnosis of iNPH. CONCLUSION: Dual-task related changes in spatio-temporal gait parameters before and after CSF tapping might be a novel and discriminative method of identifying iNPH patients from other similar conditions

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

ETUDE MOLECULAIRE DU POLYMORPHISME DES GENES DE LA BETA-GLOBINE DU CHROMOSOME 11 HUMAIN IMPLIQUES DANS L'EXPRESSION DE LA DREPANOCYTOSE EN CÔTE D'IVOIRE

Sickle cell disease is an autosomal inherited hemoglobinopathy. It is due to a point mutation (SNP) in the hemoglobin beta chain. Each mutation is correlated with a specific sickle cell allele; and the distribution of these alleles is a function of geographic area. In Côte d'Ivoire, the frequent abnormal alleles are the S allele and the C allele. In addition to the alleles, the clinical expressivity of this condition also depends on the haplotype of the hemoglobin. These genes groups are transmitted together because they are genetically close. Screening is essentially done by hemoglobin electrophoresis. However, this technique has certain limitations related to the cost, the length of time it takes to obtain results, the availability of equipment and the storage of samples. Sickle cell disease affects about 12% of the Ivorian population; associated with malaria, these two conditions present a real public health problem. This work allowed us to determine the prevalence of sickle cell disease in patients with uncomplicated malaria, to identify haplotypes of hemoglobin circulating in Abidjan and to set up molecular typing techniques of hemoglobin. Thus, we note a very variable distribution of sickle cell alleles according to the regions; and the presence of haplotypes correlated with a severe expressivity of sickle cell disease.La drépanocytose est une hémoglobinopathie héréditaire autosomale. Elle est due à une mutation ponctuelle (SNP) au niveau de la chaîne bêta de l’hémoglobine. Chaque mutation est corrélée à un allèle drépanocytaire spécifique ; et la répartition de ces allèles est fonction de la zone géographique. En Côte d’Ivoire, les allèles anormaux fréquents sont l’allèle S et l’allèle C. En plus des allèles, l’expressivité clinique de cette affection dépend également de l’haplotype de l’hémoglobine. Il s’agit de groupes de gènes transmis ensemble car génétiquement proches. Le dépistage se fait essentiellement par électrophorèse de l’hémoglobine. Mais cette technique présente certaines limites liées au coût, à la durée du rendu des résultats, à la disponibilité du matériel et à la conservation des échantillons. La drépanocytose touche environs 12% de la population ivoirienne ; associée au paludisme, ces deux affections présentent un véritable problème de santé publique. Ce travail nous a permis de faire la prévalence de la drépanocytose chez les patients atteints de paludisme simple, d’identifier les haplotypes de l’hémoglobine circulant à Abidjan et de mettre en place des techniques de typage moléculaire des hémoglobines. Ainsi, on note une distribution très variable des allèles drépanocytaires selon les régions ; et la présence d’haplotypes corrélés à une expressivité sévère de la drépanocytose

Hindered Glymes for Graphite-Compatible Electrolytes

International audienceOrganic carbonate mixtures are used almost exclusively as lithium battery electrolyte solvents. The linear compounds (dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate) act mainly as thinner for the more viscous and high-melting ethylene carbonate but are the least stable component and have low flash points; these are serious handicaps for lifetime and safety. Polyethers (glymes) are useful co-solvents, but all formerly known representatives solvate Li+ strongly enough to co-intercalate in the graphite negative electrode and exfoliate it. We have put forward a new electrolyte composition comprising a polyether to which a bulky tert-butyl group is attached (“hindered glyme”), thus completely preventing co-intercalation while maintaining good conductivity. This alkyl-carbonate-free electrolyte shows remarkable cycle efficiency of the graphite electrode, not only at room temperature, but also at 50 and 70 °C in the presence of lithium bis(fluorosulfonimide). The two-ethylene-bridge hindered glyme has a high boiling point and a flash point of 80 °C, a considerable advantage for safety

Review—Gassing Mechanisms in Lithium-ion Battery

International audienceThis paper provides a holistic view of the different studies related to gassing in NMC/graphite lithium-ion batteries over the past couple of decades of scientific development. It underlines the difficulty of predicting the concentration and the proportion of gas released upon cycling and storage and to get a clear mechanistic insight into the reduction and oxidation pathways of electrolyte solvents, the thermal electrolyte degradation, as well as the reactions that involve secondary sources such as water, NMC surface species and cross-talk reactions. Though many relevant experiments such as operando gas analysis using isotope-labeled solvents or two-compartment cells have been conducted, they failed, for instance, to determine the exact mechanism leading to the generation of CO and CO 2 gas. Last but not least, this paper discusses different strategies that are currently proposed to reduce or eliminate gassing such as the use of electrolyte additives that enable singlet oxygen quenching or scavenging, NMC coatings that limit the contact with electrolyte and different lithium salts to prevent thermal electrolyte degradation