954 research outputs found

    Automatic guidance of an off-road mobile robot with a trailer: Application to the control of agricultural passive towed implements

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    International audienceThis paper presents the study of both steering and speed control algorithms of an off-road mobile robot in order to accurately guide, forward or backward, the position of its trailer with respect to a planned trajectory, whatever ground conditions and trajectory shape. The proposed algorithms are based on an extended kinematic model of the system, accounting for sliding effects with additional sliding parameters. An observer is developed to obtain a relevant on-line estimation of these parameters. An original steering control algorithm is then proposed, considering the implement as an independent virtual vehicle: A first control law calculates the direction of the linear velocity vector at the hitch point that would ensure the convergence of this virtual vehicle to the planned trajectory. Next, a reference angle between the tractor and the implement leading to such a velocity vector is inferred, and finally a second control law is designed to stabilize the actual tractor implement angle on this reference angle. The capabilities of the proposed algorithms are investigated through full-scale experiments

    Maneuvers automation for agricultural vehicle in headland

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    International audienceThis paper addresses the problem of path generation and motion control for the autonomous maneuvers of agricultural vehicle in headland. A reverse turn planner is firstly presented, based on primitives connected together to easily generate the reference motion. Next, the steering and speed control algorithms are considered. To perform accurate path following, the sliding conditions are taken into account with a kinematic model extended with sliding parameters. In addition, predictive actions are developed to anticipate for vehicle steering and speed variations. The capabilities of the proposed algorithms are finally investigated through full-scale experiments. Fish-tail maneuvers are autonomously performed with an experimental mobile robot, and promising results are reported during reverse turn maneuvers with a vehicle-trailer system

    La recherche juridique sur les prélèvements biologiques réalisés dans le cadre des autopsies et objets de scellés judiciaires. Nécessité d'une adaptation législative

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    Currently, it is legally impossible to conduct scientific research on tissue and organ samples taken from forensic autopsies. In fact, the law schedules the destruction of such samples at the end of the judicial investigation, and the common law rules governing cadaver research cannot be applied to the forensic context. However, nothing seems in itself to stand in the way of such research since, despite their specific nature, these samples from forensic autopsies could be subject, following legislative amendments, to common law relating to medical research on samples taken from deceased persons. But an essential legislative amendment will have the goal firstly to allow the Biomedicine Agency to become authorized to issue a research permit and secondly, to change the research conditions in terms of the non-opposition of the deceased to the said research. Such an amendment would be a true breakthrough because it would allow teams to continue to move forward calmly in research, and allow this research to be placed within a legal framework, which would promote international exchanges

    A Laser System for the Spectroscopy of Highly-Charged Bismuth Ions

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    We present and characterize a laser system for the spectroscopy on highly-charged ^209Bi^82+ ions at a wavelength of 243.87 nm. For absolute frequency stabilization, the laser system is locked to a near-infra-red laser stabilized to a rubidium transition line using a transfer cavity based locking scheme. Tuning of the output frequency with high precision is achieved via a tunable rf offset lock. A sample-and-hold technique gives an extended tuning range of several THz in the UV. This scheme is universally applicable to the stabilization of laser systems at wavelengths not directly accessible to atomic or molecular resonances. We determine the frequency accuracy of the laser system using Doppler-free absorption spectroscopy of Te_2 vapour at 488 nm. Scaled to the target wavelength of 244 nm, we achieve a frequency uncertainty of \sigma_{244nm} = 6.14 MHz (one standard deviation) over six days of operation.Comment: Contribution to the special issue on "Trapped Ions" in "Applied Physics B

    Association of Patient Profile with Glycemic Control and Hypoglycemia with Insulin Glargine 300 U/mL in Type 2 Diabetes: A Post Hoc Patient-Level Meta-Analysis

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    ABSTRACT Aims: To examine the association of baseline patient characteristics with study outcomes in people with type 2 diabetes receiving insulin glargine 300 U/mL (Gla-300) versus glargine 100 U/mL (Gla-100), over a 6-month period. Methods: A post hoc patient-level metaanalysis using data from three multicenter, randomized, open-label, parallel-group, phase 3a studies of similar design, in people previously receiving either basal and prandial insulin, basal insulin ? oral antihyperglycemic drugs, or no prior insulin (EDITION 1, 2 and 3, respectively). The endpoints, glycated hemoglobin (HbA1c), hypoglycemia, body weight change, and insulin dose were investigated by subgroups: age (\65 and C 65 years), body mass index (BMI; \ 30 and C 30 kg/m2), age at onset (\40, 40–50, and [ 50 years), and diabetes duration (\ 10 and C 10 years). Results: Reduction in HbA1c was comparable between insulins, regardless of subgroup. The lower risk of C 1 nocturnal (00:00–05:59 h) confirmed (B 3.9 mmol/L [B 70 mg/dL]) or severe hypoglycemic event with Gla-300 versus Gla-100 was also unaffected by participant characteristics. While heterogeneity of treatment effect between diabetes duration subgroups was seen for the risk of C 1 confirmed (B 3.9 mmol/L [B 70 mg/dL]) or severe hypoglycemic event at any time (24 h), treatment effect consistently favored Gla-300; no evidence of heterogeneity was observed for the other subgroups. Annualized rates of confirmed (B 3.9 mmol/L [B 70 mg/dL]) or severe hypoglycemia and body weight change were not influenced by participant characteristics; a similar pattern was observed with insulin dose. Conclusions: Comparable glycemic control was observed with Gla-300 versus Gla-100, with less hypoglycemia, regardless of age, BMI, age at onset or diabetes duration. Funding: Sanofi. Plain Language Summary: Plain language summary available for this article. Keywords: Glycated Hemoglobin A; Hypoglycemia; Insulin Glargine; Type 2 Diabetes PLAIN LANGUAGE SUMMARY Treatments for patients with type 2 diabetes aim to reduce the levels of blood glucose and can include injections with insulin. However, care must be taken to prevent blood glucose levels falling too low (a state called hypoglycemia). Previous studies have shown that insulin glargine 300 units/mL (Gla-300) provides similar reductions in blood glucose levels as insulin glargine 100 units/mL (Gla-100) but is less likely to cause hypoglycemia. However, different patients may respond differently to treatments depending on their individual clinical and biological characteristics. The aim of this study was to evaluate how different profiles of patients with type 2 diabetes responded to Gla-300 and Gla-100 injections. Patients were grouped by different ages, weights, age at diabetes diagnosis, and number of years since diagnosis of diabetes. We found that Gla-300 and Gla-100 reduced glycated hemoglobin (HbA1c; a marker of blood glucose control over the previous 2–3 months) similarly, regardless of how patients were grouped. However, patients treated with Gla-300 were less likely to experience hypoglycemia than those treated with Gla-100, and this association was also true regardless of different patient characteristics. We therefore concluded that Gla-300 is an effective and safe treatment in patients with type 2 diabetes, regardless of their age, weight, age at diabetes diagnosis, and years since diagnosis

    Low Temperature Plasma Synthesis of Nanocrystals and their Application to the Growth of Crystalline Silicon and Germanium Thin Films

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    International audienceWe summarize our research studies on the synthesis of silicon and germanium nanocrystals and their application to the growth of a variety of thin films, spanning the range from fully disordered amorphous up to fully ordered crystalline. All these films are deposited in a standard radio-frequency glow discharge system at low temperature (~200 °C). We show how the plasma synthesis of silicon nanocrystals, initially a side effect of powder formation, has become over the years an exciting field of research which has opened the way to new opportunities in the field of materials deposition and their application to optoelectronic devices. Our results suggest that epitaxy requires the melting/amorphization of the nanocrystals upon impact on the substrate, the subsequent epitaxial growth being favored on (100) c-Si substrates. As a consequence, the control of the impact energy is a critical aspect of the growth which will require new strategies such as the use of tailored voltage waveforms

    Effect of sotagliflozin as an adjunct to insulin therapy on blood pressure and arterial stiffness in adults with type 1 diabetes: A post hoc pooled analysis of inTandem1 and inTandem2

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    Objective: Evaluate the effect of sotagliflozin, a dual inhibitor of sodium glucose cotransporter (SGLT) 1 and 2, on arterial stiffness in patients with type 1 diabetes (T1D) treated with sotagliflozin as adjunct to optimized insulin therapy. Methods: In this post hoc analysis, indirect markers of arterial stiffness, including pulse pressure, mean arterial pressure (MAP), and double product, were calculated using observed systolic blood pressure (SBP), diastolic blood pressure (DBP), or pulse rate at 24 weeks using data from a pooled patient population from the inTandem1 and inTandem2 randomized controlled trials (n = 1575). Results: Baseline characteristics were similar among groups. Relative to placebo at Week 24, sotagliflozin 200 mg and 400 mg reduced SBP by 2.03 mm Hg (95% CI −3.30 to −0.75; p = 0.0019) and 2.85 mm Hg (−4.12 to −1.57; p < 0.0001), respectively. DBP decreased by 1.1 and 0.9 mm Hg, MAP by 1.4 and 1.6 mm Hg, and double product by 202.5 and 221.1 bpm × mm Hg, respectively (p < 0.05 for all). No increases in heart rate were observed. Conclusion: In adults with T1D, adding sotagliflozin to insulin significantly reduced blood pressure and other markers of arterial stiffness and vascular resistance
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