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Optimal trajectory planning for industrial robots: Minimizing time, jerk, and energy consumption using LSTM for energy profile modeling
No full textInternational audienceDue to the continuous rise in energy costs for industrial robots (IRs), energy conservation has become one of the primary concerns in modern industry. This article presents a new, efficient approach for optimal trajectory planning of industrial robots in terms of time, jerk, and energy, while taking into consideration the kinematic constraints of the robot. A fifth-order B-spline interpolation method is adopted for curve fitting the trajectory in joint space to ensure smooth and continuous jerk in the robot’s articulation movements. The adjustable parameters of the trajectory are then optimized using the non-dominated sorting genetic algorithm II (NSGA-II) to minimize traveling time, jerk, and energy consumption (EC) throughout the trajectory. Unlike time and jerk, establishing a precise mathematical relationship between energy consumption and the dynamics of a robot across different trajectories is challenging and not easily applicable. This study uses the deep learning technique long short-term memory (LSTM) to accurately uncover the quantitative relationships between trajectory operational parameters and energy consumption. The main advantage of this approach, compared to other proposed optimizations, is that it can predict and optimize the robot’s energy consumption before the real-time execution of the task, and it does not require setting a priori the overall execution time of the trajectory. The results on a six degree of freedom industrial robot demonstrate that the suggested approach reduces energy consumption by 49.87% and average absolute jerk by 60.56% compared to chord length distribution method with the same trajectory execution time
Planetary-scale heterotrophic microbial community modeling assesses metabolic synergy and viral impacts
No full textConflit d'intérêt : Steven Hallam est le co-créateur de Koonkie Inc (solution de bioinformatique)The oceans buffer against climate change via biogeochemical cycles underpinned by microbial metabolic activities. While planetary-scale surveys provide baseline microbiome data, inferring metabolic and biogeochemical impacts remains challenging. Here, we constructed a model for each TARA Ocean metagenome or metatranscriptome representing heterotrophic prokaryotes and their viruses and assessed these as community-wide metabolic phenotypes. To validate, we showed that even with reaction-mappable genes only (∼1/4 of the total genes), the composition of these models revealed metabolism-inferred ecological zones that matched taxonomy-inferred zones. Model inferences include providing a new metric of community-wide metabolic cooperation and new insights into connections between microbial metabolism and organism diversity, and the ecological role of viruses. The latter suggests they genomically target community-critical metabolic reactions and estimates where viruses remineralize versus sink carbon. While this new constraints-based, agile, and mechanistic modeling framework is highly upgradable, it already begins to convert molecular-scale environmental omics data to ecological and even planetary-scale biogeochemical features that will better bring microbes and their viruses into earth system and climate models
Pouvoir comptable et risque marchand : la joaillerie Briers-Heusch-von Cassel (Francfort-sur-le-Main, années 1620)
No full textInternational audienceThis study is about Frankfurter jewellers active in the 1620s. Although their activity takes place in a global horizon, renewed by the new connections built by the Dutch East India Company, the study is restricted to Europe in order to focus on the accounting records left by the merchants. Those question immediately the mercantile knowledges of the jewellers, or, more precisely, skills asymmetries within the merchant group. A very striking feature of the seemingly straightforward trade of the group (buying rough stones in Antwerp or Amsterdam, processing it in or around Antwerp or Frankfurt, selling it to the courts of Northern Europe, especially the imperial court) is the risks involved: without extremely high profits, a cash crisis caused by the slow temporality of sales and payment recoveries, as well as by a limited duration of purchase credit, was unavoidable. In this race against time, the demand adjustment variable was not the price, but the circulation of merchandise: jewels were offered in successive princely courses so as to avoid unsold items. The merchant group also managed trade risks by the division of the jewels’ ownership into indefinitely reconfigurable shares. This organization - covering space and dividing risk – was characterized both by its openness to outside investment and by the clear hierarchy within the merchant group. Ultimately, it was based on an bookkeeping system, managed from Frankfurt, that was not only complex, but also hermetically sealed for several merchants of the company - a system of power and control, which existence calls into question the primacy given to concepts such as law or trust in the description of modern trade networks.Le texte prend comme objet un groupe joaillier actif dans les années 1620. Bien que l’horizon de son activité soit mondial, et renouvelé par les compagnies des Indes nord-européennes, le cadre de l’étude se restreint à l’Europe pour concentrer le regard sur les sources comptables, qui questionnent immédiatement savoirs et asymétries de savoirs (mercantiles, artisanaux) existant au sein de ce groupe. En apparence très simple (achat de pierres brutes à Anvers ou Amsterdam, façon de celles-ci à Anvers, Francfort ou autour de cette ville, vente aux cours nord-européennes dont surtout la cour impériale), ce commerce frappe par l’importance des risques qu’il encourt : seule l’importance des profits permet d’éviter une crise de trésorerie provoquée par la lenteur des ventes et des recouvrements, alors que les crédits à l’achat ne peuvent être indéfiniment prolongés. L’ajustement à la demande, dans cette course contre la montre, ne passe pas par le prix mais par la circulation européenne des joyaux proposés à la vente ; la gestion du risque, elle, passe par la division de la propriété des joyaux en parts indéfiniment reconfigurables. Cette organisation – couverture de l’espace et division des risques – se caractérise à la fois par son ouverture aux investissements extérieurs et par la nette hiérarchie interne au groupe qu’elle organise. Elle repose en définitive sur la mise en place et le maniement, depuis Francfort, d’un système comptable non seulement complexe mais hermétique à plusieurs membres du groupe – un système de pouvoir et de contrôle, dont l’existence questionne le primat accordé à des notions telles que le droit ou la confiance dans la description de réseaux marchands modernes
Quand les communautés de pratique deviennent des entrepreneurs institutionnels favorisant l’innovation au sein des territoires
No full textInternational audienceL’objectif de cette contribution est de discuter les critères comportementaux d’une communauté de pratique (CoP) qui devient un entrepreneur institutionnel favorisant l’innovation au sein d’un territoire. Les autrices apportent un regard approfondi, de nature longitudinale, sur les modes d’influence de ce type d’institution informelle face aux institutions formelles présentes dans ce territoire. L’étude d’une CoP de startups, située dans la ville de Belo Horizonte, au Brésil, met en lumière sa logique institutionnelle qui désigne des critères communautaires spécifiques. Les résultats de la recherche montrent comment le pouvoir de cette logique institutionnelle se déploie, notamment quand elle se considère menacée par des institutions formelles du territoire pour mettre en œuvre leurs dynamiques d’innovation. Les comportements institutionnels identifiés de cette CoP transforment progressivement l’écosystème d’innovation de la ville
Loci of exactness for the real and imaginary parts of truncated Taylor series of analytic functions
No full textTaylor series expansions of analytic functions are often truncated for practical uses. The overall accuracy of truncated series is generally believed to improve as the number of terms retained increases. However, the graphical representation of the real and imaginary parts of the difference between analytic functions and their truncated series exhibits loci where truncated series can provide exact values. In particular, near the expansion point, the loci of exactness are observed to gather on curves emanating from it. The number and tangential angles of these curves at the expansion point are shown to be related to the exponent and the coefficient of the first term in the remainder associated with the truncated series. These curves of loci of exactness can be further studied from a mathematical perspective and be employed, for instance, in the design of analytical and numerical procedures for the accurate identification of series coefficients
From non-coding to chromatin regulators: VIVIpary and the rise of lncRNAs in plant biology
No full textInternational audienc
The impact of Kirrel1 isoform expression on the in vitro differentiation and fusion of skeletal muscle myoblasts
No full textMyoblast fusion is critical for multinucleated myofiber formation, yet the mechanisms driving this process in vertebrates are still not well understood. Kirrel proteins play a key role in the recognition and adhesion between myoblasts and myotubes. This study examines the roles of the Kirrel1 variants, Kirrel1A and Kirrel1B, during vertebrate myoblast differentiation and fusion in vitro. To achieve this, several C2C12 cell lines with altered Kirrel1A and Kirrel1B expression were developed, including: 1) separate lines overexpressing Kirrel1A, Kirrel1B, or a Kirrel1A with an mCherry insert in the cytoplasmic domain, 2) kirrel1A and kirrel1B shRNA knockdown lines, and 3) a CRISPR/Cas9-line with modified kirrel1. Overexpression of Kirrel1A or Kirrel1B had little impact on myotube formation. The Kirrel1A-mCherry insert resulted in a dominant loss of function presenting lack on myotube formation. Kirrel1A knockdown inhibited myotube formation, despite elevated Kirrel1B levels. CRISPR/Cas9 removed the selected region from one allele. The regulatory region of the other allele was modified. These changes resulted in severely delayed myotube formation. Non-reducing Western blots revealed a Kirrel1A-containing large 350 kDa complex in cells that formed myotubes. It was absent when myogenesis was inhibited: when Kirrel1A was knocked down or in the presence of Kirrel1A expressing an mCherry-altered cytoplasmic tail or when Kirrel1B protein expression was excessive compared to Kirrel1A. In conclusion, these findings show that Kirrel1A, but not Kirrel1B, is essential for myogenesis. Furthermore, modification of the Kirrel1A cytoplasmic tail prevented myotube production, thus operating as a dominant loss of function mutant
Transgene-Induced Cardiotoxicity In High-Dose AAV Gene Transfer
No full textGene delivery technologies based on adeno-associated virus (AAV) vectors have yielded promising results for the treatment of monogenic diseases. Preclinical studies and clinical trials have highlighted that infusing high AAV vector doses can induce cytotoxicity, resulting in the death of the patient in a few cases. In the wake of signs of cardiac symptoms in several human patients after gene transfer, we investigated the effects on the heart of systemic administration of high doses of AAV vectors expressing three different transgenes, corresponding to Duchenne muscular dystrophy, γ-sarcoglycanopathy and Fukutin-related Protein (FKRP) deficiency. In all these cases, we observed the possibility of cardiotoxicity with high-dose injections that we related to transgene expression. Consequently, strategies reducing or preventing the expression in the heart prevented the appearance of such cardiotoxicity and were also confirmed to be safe in Non-Human Primates. Dissection of the mechanisms at stake revealed activation of stress cascades, leading to cardiomyocyte death due to protein overload or abnormal homeostasis of location or function of the specific protein. Our data highlighted a particular sensitivity of the heart to transgene expression, suggesting the importance of finely regulating the expression of transgenes in this vital organ in any gene therapy approach
