La Recherche Research Articles

All taxa biodiversity inventory of the Bois de Bouis estate (Var, France): a 10-year public-private partnership.

This data paper describes the results of a 10-year scientific investigation of a biodiversity-rich private golf estate in south-eastern France in partnership with PatriNat (Office français de la biodiversité/Centre national de la recherche scientifique/Muséum national d'Histoire naturelle, Institut de Recherche pour le Développement). In total, 3,160 species and subspecies, including 1,796 arthropods and 1,049 flora, were inventoried and 65 habitat types were surveyed and mapped. This project is the first All taxa biodiversity inventory (ATBI) in a private property in France with all information available in open data. The 20 datasets of fauna, flora, lichens and habitat types from the Bois de Bouis estate are now publicly available. Between 2012 and 2022, more than 22,000 occurrences were recorded, checked and published in the INPN information system. All this information is available in open access in the French portal OpenObs, operated by PatriNat and in the Global Biodiversity Information Facility (GBIF). This data paper provides an overview of the project, its main results and its contribution to the French National Inventory of Natural Heritage (INPN).This data paper presents a list eight species never previously recorded to France; three Hymenoptera: Charitopesleucobasis Townes, 1983 (Ichneumonidae), Dryinustussaci Olmi, 1989 (Dryinidae) and Sparasionmunitus Kozlov & Kononova, 1990 (Sparasionidae) and five Diptera: Clusiodesapicalis (Zetterstedt, 1848) (Clusiidae), Dicraeusvagans (Meigen, 1838) (Chloropidae), Stilponintermedius Raffone, 1994, Stilponsubnubilus Chvala, 1988 and Tachydromiaundulata (Strobl, 1906) (Hybotidae).It also includes a table comparing the project to 18 All-taxa biodiversity inventories in France and Belgium and published for the first time.

Tryptophan metabolism promotes immune evasion in human pancreatic β cells

To resist the autoimmune attack characteristic of type 1 diabetes, insulin producing pancreatic β cells need to evade T-cell recognition. Such escape mechanisms may be conferred by low HLA class I (HLA-I) expression and upregulation of immune inhibitory molecules such as Programmed cell Death Ligand 1 (PD-L1). The expression of PD-L1, HLA-I and CXCL10 was evaluated in the human β cell line, ECN90, and in primary human and mouse pancreatic islets. Most genes were determined by real-time RT-PCR, flow cytometry and Western blot. Activator and inhibitor of the AKT signaling were used to modulate PD-L1 induction. Key results were validated by monitoring activity of CD8+ Jurkat T cells presenting β cell specific T-cell receptor and transduced with reporter genes in contact culture with the human β cell line, ECN90. In this study, we identify tryptophan (TRP) as an agonist of PD-L1 induction through the AKT signaling pathway. TRP also synergistically enhanced PD-L1 expression on β cells exposed to interferon-γ. Conversely, interferon-γ-mediated induction of HLA-I and CXCL10 genes was down-regulated upon TRP treatment. Finally, TRP and its derivatives inhibited the activation of islet-reactive CD8+ T cells by β cells. Collectively, our findings indicate that TRP could induce immune tolerance to β cells by promoting their immune evasion through HLA-I downregulation and PD-L1 upregulation. Dutch Diabetes Research Foundation, DON Foundation, the Laboratoire d'Excellence consortium Revive (ANR-10-LABX-0073), Agence Nationale de la Recherche (ANR-19-CE15-0014-01), Fondation pour la Recherche Médicale (EQ U201903007793-EQU20193007831), Innovative Medicines InitiativeINNODIA and INNODIA HARVEST, Aides aux Jeunes Diabetiques (AJD) and Juvenile Diabetes Research Foundation Ltd (JDRF).

Identifying physical and psychological risk factors for musculoskeletal pain in student musicians to tailor the curriculum: a cross-sectional study protocol

IntroductionInsufficient identification and understanding of risk factors make musicians engaging in professional practice particularly vulnerable to musculoskeletal pain. To support positive music learning and good mental, physical, and social health,...

Preface

The 12th International Workshop on Ship and Marine Hydrodynamics 28 August to 1 September 2023 Aalto University, Espoo, Finland Editors Eur.Ing. Dr. Spyros Hirdaris CEng FRINA, FSNAME Aalto University, Finland AND Professor Decheng Wan Shanghai Jiao Tong University, China The 12th International Workshop on Ship and Marine Hydrodynamics (IWSH 2023) was held from the 28th of August to the 1st of September 2023 at Aalto University, Finland. Aalto University was established in 2010 as a merger the Helsinki University of Technology (HUT), the Helsinki School of Economics and the University of Art and Design of Helsinki. Marine and Arctic Technology has been solid part of the well cherished traditions of HUT dating back to the 19th century.IWSH inaugurated by Prof. Zaojian Zou of Wuhan University of Technology in 1999. Early national events were organised by Wuhan University of Technology (2001,2003), Shanghai Jiao Tong University (2005), Jiangshu University of Science and Technology (2007) and Harbin Engineering University (2009).In 2011 Professor Decheng Wan organised the first international version of the workshop at Shanghai Jiao Tong University. Since then, the event has been organised by Seoul National University - South Korea (2013), the University of Strathclyde - UK (2015), the National Taiwan Ocean University (2017) and Hamburg University of Technology - Germany (2019). The 2021 edition of IWSH did not take place because of the COVID-19 pandemic. The “all-inclusive” nature of the 12th sequel of the workshop held in 2023 included scientific and social activities, fostering opportunities for networking.The workshop focused on publications of relevance to ship dynamics, hydrodynamics, wave mechanics, sea loads and responses, fluid structure interactions, ship resistance and propulsion, etc. Notably, emerging multiphysics methods with application on both ships and ocean engineering including renewable energies were evident. Six keynotes were delivered by Dr. Nuno Fonseca of SINTEF (Norway), Dr. Sime Malenica of Bureau Veritas (BV, France), Alessandro Iafrati of Istituto di iNgegneria del Mare (INM, Italy), Dr. Michel Visonneau of Centre National de la Recherche Scientifique (CNRS, France), Professor Stefano Brizzolara of Virginia Technological Institute and State University (USA) and Professor Yonghwan Kim of Seoul National University (South Korea), were invited to foster top level discussion on relevant subjects. As part of the workshop proceedings the main event sponsor, SINTEF Ocean (Norway) hosted a special session of their International Collaboration Network in Marine Technology.The oral technical program was organized in parallel sessions. In these proceedings, the papers are organized by major themes. The themes are: (1) Ship dynamics, (2) Wave mechanics, (3) Fluid Structure Interactions, (4) Ship motions and sea loads, (5) Ocean Engineering, (6) Ship resistance, (7) Marine propulsion.The workshop confirmed that the complexity of the subject as related to conventional and emerging technologies attracts a great deal of interest of relevance to engineering science and technological innovation. The field of ship and marine hydrodynamics remains more than relevant for the safety and sustainability of the ship and ocean engineering sectors. Dr. Spyros Hirdaris CEng FRINA FSNAME Aalto University, Espoo, Finland, September 2023 List of Sponsors, Reviewers acknowledgement, Aalto University’s IWSH 2023 local organizing committee, IWSH 2023 International Standing Committee, IWSH 2023 International Scientific Committee are available in this pdf.

Global research on ubiquitous learning: A network and output approach

Ubiquitous learning refers to the advancement of online learning, adapted to the development of communication and informatics. The study aimed to carry out a bibliometric approach to ubiquitous learning worldwide indexed in Scopus from 2003 to 2023. Methodologically, it was a quantitative, bibliometric study. Scientific output indicators were generated from 2668 selected Scopus papers using English keywords ("ubiquitous" AND "learning"). From 2007 to 2023, the number of published documents increased (90.9%), indicating a growing interest in the subject of study. The United States has the highest scientific production (21%), and the CNRS Centre National de la Recherche Scientifique has the most publications (n=39). The journal IEEE Access received 2514 citations, with the author Cook, D.J. (n=532) being the most cited. It is concluded that the orientation on ubiquitous learning is dynamic and increasingly linked to the development of information and communication technologies (ICT), as this learning style uses technology to give students more independence over their learning process.

Research Productivity of Design Education

The research conducted to do an analysis of research productivity related to original character (OC) research based on open access journal indexed in Scopus from 2013 to 2022. The methods used in this research is bibliometric. The results of this research found the number of OC research publications in open access journal from 2013 to 2022 shows a dynamic trend. Publication data with the keyword original character with the highest amount of documents is Plos One with 44 documents. CNRS Centre National de la Recherche Scientifique with 90 documents as an affiliation with the most documents. Subject area in the field of arts and humanities dominates with 722 documents. The most occurrences from the graph shows “species” as the most related item with the original character research trend from 2013 to 2022 in Scopus open access journal database.

Productivity Analysis of Original Character (OC) Research in Open Access Journal Indexed by Scopus

The research conducted to do an analysis of research productivity related to original character (OC) research based on open access journal indexed in Scopus from 2013 to 2022. The methods used in this research is bibliometric. The results of this research found the number of OC research publications in open access journal from 2013 to 2022 shows a dynamic trend. Publication data with the keyword original character with the highest amount of documents is Plos One with 44 documents. CNRS Centre National de la Recherche Scientifique with 90 documents as an affiliation with the most documents. Subject area in the field of arts and humanities dominates with 722 documents. The most occurrences from the graph shows “species” as the most related item with the original character research trend from 2013 to 2022 in Scopus open access journal database.

Combining robust urine biomarkers to assess chronic kidney disease progression.

Urinary biomarkers may improve the prediction of chronic kidney disease (CKD) progression. Yet, data reporting the applicability of most commercial biomarker assays to the detection of their target analyte in urine together with an evaluation of their predictive performance are scarce. 30 commercial assays (ELISA) were tested for their ability to quantify the target analyte in urine using strict (FDA-approved) validation criteria. In an exploratory analysis, LASSO (Least Absolute Shrinkage and Selection Operator) logistic regression analysis was used to identify potentially complementary biomarkers predicting fast CKD progression, determined as the 51CrEDTA clearance-based measured glomerular filtration rate (mGFR) decline (>10% per year) in a subsample of 229 CKD patients (mean age, 61 years; 66% men; baseline mGFR, 38mL/min) from the NephroTest prospective cohort. Among the 30 assays, directed against 24 candidate biomarkers, encompassing different pathophysiological mechanisms of CKD progression, 16 assays fulfilled the FDA-approved criteria. LASSO logistic regressions identified a combination of five biomarkers including CCL2, EGF, KIM1, NGAL, and TGF-α that improved the prediction of fast mGFR decline compared to the kidney failure risk equation variables alone: age, gender, mGFR, and albuminuria. Mean area under the curves (AUC) estimated from 100 re-samples was higher in the model with than without these biomarkers, 0.722 (95% confidence interval 0.652-0.795) vs. 0.682 (0.614-0.748), respectively. Fully-adjusted odds-ratios (95% confidence interval) for fast progression were 1.87 (1.22, 2.98), 1.86 (1.23, 2.89), 0.43 (0.25, 0.70), 1.10 (0.71, 1.83), 0.55 (0.33, 0.89), and 2.99 (1.89, 5.01) for albumin, CCL2, EGF, KIM1, NGAL, and TGF-α, respectively. This study provides a rigorous validation of multiple assays for relevant urinary biomarkers of CKD progression which combination may improve the prediction of CKD progression. This work was supported by Institut National de la Santé et de la Recherche Médicale, Université de Paris, Assistance Publique Hôpitaux de Paris, Agence Nationale de la Recherche, MSDAVENIR, Pharma Research and Early Development Roche Laboratories (Basel, Switzerland), and Institut Roche de Recherche et Médecine Translationnelle (Paris, France).

Nordic Travels

Nordic Travels

Machine learning for the generation of personalized image analysis protocol in echocardiography: a pilot study in arterial hypertension

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Agence National de la Recherche Europian Union-NextGenerationEU. Background Current workflow in cardiac imaging is based on protocols meant to capture a set of predefined images for a certain condition [1]. Although standardized, such approaches are not personalized, and are often time- and resource-ineffective. Reinforcement learning (RL), a subfield of machine learning that addresses decision making [2], can be used to incorporate complex, whole cardiac cycle imaging data, while optimizing costs associated to data acquisition and processing – including economy, patient safety/comfort and examination time. Our aim is to demonstrate the viability of RL to create a personalized, resource-effective data analysis routine from echocardiography to separate remodelling in arterial hypertension from normal cardiac function. Methods An echo study was performed in 189 clinically managed hypertensive (HTN) patients, and 60 non-hypertensive healthy control subjects [3]. Speckle-tracking analysis of the left ventricle was performed and deformation curves extracted. Aortic and mitral flow pulsed-wave (PW) Doppler and septal basal tissue PW Doppler velocity profiles were obtained. These whole cardiac cycle deformation and velocity curves were used as input data to the RL algorithm. RL optimized the required image analysis sequence to maximize the probability of obtaining a correct diagnosis while reducing the number of analysed images. Results The RL-generated protocol identified three separate image analysis groups to determine cardiac remodelling (Figure 1). The proposed protocol starts with the analysis of the mitral PW, and based on its velocity pattern, assigns each individual to one of the three groups. In Group 1 (G1, n=158) analysing the mitral PW acquisition was sufficient to determine disease status. HTN patients were separated based on a pattern of an inversed E/A ratio and EA fusion reflecting signs of diastolic dysfunction. In G2 (n=56), mitral flow showed a slightly decreased E/A ratio and longer E deacceleration time, and adding aortic PW was required to determine remodelling: HTN had higher aortic peak velocity and shorter peak acceleration time due to higher systemic afterload. Finally, G3 (n=19) required global longitudinal strain, which showed pathological early systolic stretching, reflecting the change in the timing of cardiac events in arterial hypertension. Fifteen (6%) participants did not match any of the groups, requiring the acquisition of remaining sequences (TDI, regional strain) to secure a correct diagnosis. In average, the protocol analysed 1.44 images per patient, out of the four available. Conclusion Through a pilot study utilizing a limited set of imaging sequences, we demonstrate a template for automated generation of efficient, tailored image analysis protocols, that minimimize the number of analyzed images to determinine patient phenotypes. RL is a promising tool to reduce analysis time, potentially saving costs in preventive screening programs.

#3155 APOL1 GENOTYPE IS A MAJOR DETERMINANT OF LUPUS NEPHRITIS SEVERITY IN PATIENTS OF AFRICAN ANCESTRY

Abstract Background and Aims Two polymorphisms of APOL1 gene, G1 and G2, exclusively found among patients of African ancestry, have been associated with chronic kidney disease (CKD) and end-stage kidney disease (ESKD)1. These high-risk polymorphisms have also been associated with collapsing glomerulopathy in various diseases. We aimed to evaluate the impact of APOL1 G1 and G2 polymorphisms on the clinical and pathological course LN which is already known to be more severe among patients of African ancestry2. Method We included patients from 6 hospitals in Paris and Marseille in France, between January 2017 and March 2020, with biopsy-proven LN, African ancestry and age >18 years at the time of inclusion. We excluded those with HIV infection. The data were retrospectively collected at LN diagnosis, 1 year after diagnosis and at last follow-up. APOL1 genotyping was performed and we divided patients in 2 groups: the high-risk genotype (HRG) group with 2 risk alleles and the low risk genotype (LRG) group with 1 or 0 risk allele. All patients signed a consent form for the genetic analysis and protocol approval was obtained from the ethic committee CERAPHP (Comité d'Ethique de la Recherche AP-HP Centre), registration number 00011928. Results Ninety-nine patients were included in the study, 13 in the HRG group and 86 in the LRG group. The median duration between LN diagnosis and inclusion in the study was 9.6 years [4.9-16.9]. At LN diagnosis, clinical and biological characteristics were similar except for kidney function that was lower in the HRG group compared to the LRG group with a median serum creatinine of 131μmol/L [69-687] versus 66μmol/L [52-133] (p = 0.0085). Patients in the HRG group were more likely to have a serum creatinine above 200 μmol/L compared to the LRG group (45.5% versus 10.5%, p = 0.0096, OR 7.1[1.8-28.6]), and required acute haemodialysis more frequently (30.8% versus 1.3% respectively, p = 0.0012, OR 34.7[3.5-345.1]). Collapsing glomerulopathy was more frequent in the HRG group (45.5% of patients, versus 4.5%, OR 17.5[3.3-91.9], p = 0.001). No significant difference was observed in the proportion of kidney response at 12 months, however, patients in the HRG group were more likely to develop CKD (33.3% versus 4.9%, OR 9.6[2.0-46.1]). Median follow-up from LN diagnosis to the end of study, ESKD or last follow-up was 7.9 years [3.4-13.3] and was similar between the 2 groups. At last follow-up, median eGFR was 22mL/min/1.73m2 [10-98] vs 99mL/min/1.73m2 [55-118] respectively, p = 0.0189. Survival without ESKD was poorer in the HRG group than in the LRG group with a hazard ratio (HR) of 5.0[1.6-15.8], p = 0.006, even after adjusting with the kidney response at 12 months (adjusted HR 6.24[1.8-21.6], p = 0.004) (Figure 1). Conclusion APOL1 genotype affects LN prognosis, resulting in a worse kidney function at diagnosis, development of collapsing glomerulopathy and higher risk of subsequent ESKD. Kidney survival remained significantly lower in the HRG group, after adjustment for kidney response at 12 months, suggesting that the prognosis of LN is heavily driven by APOL1 genotype regardless of the kidney response. APOL1 inhibitors are currently being developed, and could be used in the next future, for HRG patients with primary or secondary forms of collapsing glomerulopathy.

Importance of oxygen tension in human ovarian tissue in vitro culture.

Is there any difference between 20% and 5% oxygen (O2) tension in vitro culture (IVC) on the viability and quality of human follicles contained in cultured ovarian cortex? An O2 tension of 5% yields higher follicle viability and quality than does 20% O2 tension after 6 days of IVC. The primordial follicle (PMF) pool resides within the ovarian cortex, where the in vivo O2 tension ranges between 2% and 8%. Some studies suggest that lowering O2 tension to physiological levels may improve in vitro follicle quality rates. This prospective experimental study included frozen-thawed ovarian cortex from six adult patients (mean age: 28.5 years; age range: 26-31 years) who were undergoing laparoscopic surgery for non-ovarian diseases. Ovarian cortical fragments were cultured for 6 days at (i) 20% O2 with 5% CO2 and (ii) 5% O2 with 5% CO2. Non-cultured fragments served as controls. Cortical fragments were used for the following analyses: hematoxylin and eosin staining for follicle count and classification; Ki67 staining to evaluate PMF proliferation; cleaved caspase-3 immunostaining to identify follicle apoptosis; 8-hydroxy-2-deoxyguanosine and gamma-H2AX (γH2AX) immunolabeling to detect oxidative stress damage and DNA double-strand breaks (DSBs) in oocytes and granulosa cells (GCs); and β-galactosidase staining to assess follicle senescence. Droplet digital PCR was also performed to further explore the gene expression of superoxide dismutase 2 (SOD2) and glutathione peroxidase 4 (GPX4) from the antioxidant defense system and cyclin-dependent kinase inhibitors (p21 and p16) as tissue senescence-related genes. Apoptosis (P = 0.002) and follicle senescence (P < 0.001) rates were significantly lower in the 5% O2 group than in the 20% O2 group. Moreover, GCs in follicles in the 20% O2 group exhibited significantly (P < 0.001) higher oxidative stress damage rates than those in the 5% O2 group. DNA DSB damage rates in GCs of follicles were also significantly higher (P = 0.001) in the 20% O2 group than in the 5% O2 group. SOD2 expression was significantly greater in the 5% O2 group compared to the 20% O2 group (P = 0.04) and the non-cultured group (P = 0.002). Expression of p21 was significantly increased in both the 20% O2 (P = 0.03) and 5% O2 (P = 0.008) groups compared to the non-cultured group. Moreover, the 20% O2 group showed significantly greater p16 expression (P = 0.04) than the non-cultured group, while no significant variation was observed between the 5% O2 and no culture groups. N/A. This study focuses on improving follicle outcomes during the first step of ovarian tissue IVC, where follicles remain in situ within the tissue. The impact of O2 tension in further steps, such as secondary follicle isolation and maturation, was not investigated here. Our findings suggest that 5% O2 tension culture is a promising step toward potentially solving the problem of poor follicle viability after IVC. This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (FNRS-PDR T.0064.22, CDR J.0063.20 and grant 5/4/150/5 awarded to M.M.D.). The authors have nothing to disclose.

Mental health and homelessness in the social service providers' outlook (Luxembourg case)

Purpose The purpose of this paper is to explore the perception of the mental health problems of the homeless population in a high-income country (Luxembourg) by social service providers and to develop proposals for better inclusion of homeless people into the mental health services and homeless people with mental health issues into society. Design/methodology/approach The study was of qualitative design and conducted using a semi-structured interview method (in person). The semi-structured interviews (seven participants) were conducted to analyse the challenges, practice approaches and prospects of stakeholders or decision-makers working in housing exclusion and homelessness. A secondary thematic analysis of this content regarding mental health issues was performed. Findings Three main themes in the social providers’ perception were identified related to mental health and homelessness: the general view on the mental health problems of homeless people (accent on substance use disorders [SUDs], overshadowing of other mental health conditions by the SUDs); the positive impact of housing and social services on the mental health of the homeless per se (role of social rhythms, social connectedness and multidisciplinary approach are emphasised); and the need for improvement of mental health services in the country (need for the long-term timely continuing mental health support and recognition of the importance of complex intersectional and multidisciplinary solutions). Research limitations/implications Mental health themes were not the primary focus while research was planned and conducted. They were revealed as results of secondary qualitative data analysis. Therefore, additional mental health-focused mixed methods research is needed to verify the conclusions. The paper is written on the results of the research project “Social Housing and Homelessness” (SOHOME), implemented at the University of Luxembourg with the financial support of the Fonds National de la Recherche of Luxembourg (FNR12626464). The sponsor had no involvement in the study design, the collection, analysis and interpretation of data or the preparation of the paper. Practical implications The study brings together different perspectives from social workers, stakeholders and decision-makers. The results show that there are cross-field connections between homelessness and mental health that require specialised and coordinated services. The first existing approaches seem to be promising in their continuation but need to be promoted by social policy. Social implications To promote social cohesion in the Luxembourgish society and also to include one of the most vulnerable people, the study points to the importance of the link between homelessness and compromised mental health. Appropriate support and service provision as well as social and affordable housing play a central role. Originality/value To the best of the authors’ knowledge, this study is the first of its kind, revealing several social work stakeholders’ perspective on the mental health of homeless people in Luxembourg.

Solving Optimization Problems with Blackwell Approachability

In this paper, we propose a new algorithm for solving convex-concave saddle-point problems using regret minimization in the repeated game framework. To do so, we introduce the Conic Blackwell Algorithm+ ([Formula: see text]), a new parameter- and scale-free regret minimizer for general convex compact sets. [Formula: see text] is based on Blackwell approachability and attains [Formula: see text] regret. We show how to efficiently instantiate [Formula: see text] for many decision sets of interest, including the simplex, [Formula: see text] norm balls, and ellipsoidal confidence regions in the simplex. Based on [Formula: see text], we introduce [Formula: see text], a new parameter-free algorithm for solving convex-concave saddle-point problems achieving a [Formula: see text] ergodic convergence rate. In our simulations, we demonstrate the wide applicability of [Formula: see text] on several standard saddle-point problems from the optimization and operations research literature, including matrix games, extensive-form games, distributionally robust logistic regression, and Markov decision processes. In each setting, [Formula: see text] achieves state-of-the-art numerical performance and outperforms classical methods, without the need for any choice of step sizes or other algorithmic parameters. Funding: J. Grand-Clément is supported by the Agence Nationale de la Recherche [Grant 11-LABX-0047] and by Hi! Paris. C. Kroer is supported by the Office of Naval Research [Grant N00014-22-1-2530] and by the National Science Foundation [Grant IIS-2147361].

Large Ranking Games with Diffusion Control

We consider a symmetric stochastic differential game where each player can control the diffusion intensity of an individual dynamic state process, and the players whose states at a deterministic finite time horizon are among the best [Formula: see text] of all states receive a fixed prize. Within the mean field limit version of the game, we compute an explicit equilibrium, a threshold strategy that consists of choosing the maximal fluctuation intensity when the state is below a given threshold and the minimal intensity otherwise. We show that for large n, the symmetric n-tuple of the threshold strategy provides an approximate Nash equilibrium of the n-player game. We also derive the rate at which the approximate equilibrium reward and the best-response reward converge to each other, as the number of players n tends to infinity. Finally, we compare the approximate equilibrium for large games with the equilibrium of the two-player case. Funding: Support from the Deutsche Forschungsgemeinschaft [Grant AN 1024/5-1] is acknowledged. The research of N. Kazi-Tani is supported by the Agence Nationale de la Recherche [Grant ANR-21-CE46-0002-03]. The research of C. Zhou is supported by the National Natural Science Foundation of China [Grant 11871364], the Singapore Ministry of Education [Grants A-8000453-00-00, A-0004273-00-00 and A-0004277-00-00] and the MERLION 2020 award [Grant A-0004589-00-00].

Naive Feature Selection: A Nearly Tight Convex Relaxation for Sparse Naive Bayes

Because of its linear complexity, naive Bayes classification remains an attractive supervised learning method, especially in very large-scale settings. We propose a sparse version of naive Bayes, which can be used for feature selection. This leads to a combinatorial maximum-likelihood problem, for which we provide an exact solution in the case of binary data, or a bound in the multinomial case. We prove that our convex relaxation bounds become tight as the marginal contribution of additional features decreases using a priori duality gap bounds derived from the Shapley–Folkman theorem. We show how to produce primal solutions satisfying these bounds. Both binary and multinomial sparse models are solvable in time almost linear in problem size, representing a very small extra relative cost compared with the classical naive Bayes. Numerical experiments on text data show that the naive Bayes feature selection method is as statistically effective as state-of-the-art feature selection methods such as recursive feature elimination, l1-penalized logistic regression, and LASSO while being orders of magnitude faster (a python implementation can be found at https://github.com/aspremon/NaiveFeatureSelection ). Funding: A. d’Aspremont acknowledges support from the Fonds AXA Pour la Recherche and Kamet Ventures [Machine Learning and Optimisation Joint Research Initiative] and a Google-focused award as well as funding from Agence Nationale de la Recherche [Grant ANR-19-P3IA-0001]. L. El Ghaoui acknowledges support from Berkeley Artificial Intelligence Research and the Tsinghua–Berkeley–Shenzhen Institute.

NODULE INCEPTION: a direct regulator of gibberellin biosynthesis during symbiotic nodulation.

This article is a Commentary on Gao et al. (2023), 239: 459–465.

The Cornified Envelope: A Versatile Contributor to the Epidermal Barrier

The Cornified Envelope: A Versatile Contributor to the Epidermal Barrier

Waste lands: the lost infrastructure of Jean Rhys’s “Temps Perdi”

ABSTRACT This essay argues that Rhys’s “Temps Perdi” (1967) evokes modernist temporality – Proustian “lost time” – to connect the twentieth-century World Wars to the infrastructure of European imperialism. Set in England during World War II, Austria after World War I, and the “Carib Quarter” in Dominica in the 1930s, the story links the violence of the European wars to the violence of imperialism, and the “losses” of the twentieth century to the decayed Caribbean plantation, “Temps Perdi.” In the local patois, the phrase means not “lost time” but “wasted time, lost labor,” and recalls three hundred years of waste and ruin: the genocide of the indigenous “Caribs”; the devastation of African peoples enslaved in the Caribbean; and the “waste” of Europe itself – in the era of imperial collapse – in the destruction of the World Wars. All three of these historical realities are embedded in the story’s title, and though that title evokes the tradition of European modernism, it also marks a departure from it. Though structured, in its temporal shifting, by allusion to Proust’s À la recherche du temps perdu, “Temps Perdi” also undertakes an excavation of the material structures of modernity: the infrastructure – variously concealed, ruined, lost, or missing – that marks the spot of European devastation in the Caribbean.

Role of MR1-driven signals and amphiregulin on the recruitment and repair function of skin MAIT cells

Abstract Epithelial repair is crucial to reestablish adequate barrier integrity and function after tissue injury. In both mice and humans, MAIT (Mucosal associated invariant T) cells involvement in tissue repair is substantiated by their upregulation of tissue repair mediators following TCR-mediated activation. Additionally, in the absence of ɣδT cells, MAIT cells were shown to promote wound healing. By using both our congenic B6-MAIT CASTstrain (10× more MAIT cells than B6 mice) and a skin excision mouse model preventing epithelial contraction (mimicking the human repair process), we sought to uncover the underlying mechanisms of MAIT cell tissue repair function. Firstly, our scRNAseq analysis revealed that steady-state skin MAIT cells readily express a repair program. Additionally, we show that MAIT cells have a pro-repair function as their presence promotes keratinocyte proliferation, thereby accelerating healing. Using parabiosis, skin graft and the Kaede models, we found that, contrary to the resident ɣδT cells, MAIT cells are rapidly recruited into the inflamed skin. Parabiosis of MR1 +and MR1 −mice and MR1 −skin grafted onto MR1 +mice, showed that this recruitment was MR1-independent (MR1: antigen presenting molecule of MAIT cells). Instead, this recruitment relied on the chemokine receptor CXCR6 and its ligand CXCL16. Lastly, using conditional knock-out mice we demonstrated that the secretion by MAIT cells of the amphiregulin growth factor promotes skin wound healing. Overall, our study provides mechanistic insights into MAIT cell biology in the context of injury. Comprehension of these processes provides clues into the biology of related innate subsets and highlights potential new therapeutic avenues for wound healing. Institut National de la Santé et de la Recherche Médicale (OL) Institut Curie (OL) Agence Nationale de la Recherche Grant MAIT ANR-16-CE15-0020-01 (OL) Agence Nationale de la Recherche Grant MAITrepair ANR-20-CE15-0028-01 (OL) Agence Nationale de la Recherche ANR-10-IDEX-0001-02 PSL (OL) European Research Council (ERC-2019-AdG-885435) (OL) Fondation pour la Recherche Médicale, grant number FDT202106013036 (AdH)