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

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

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

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

Maneuvers automation for agricultural vehicle in headland

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

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

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

Histopathologic Alterations Associated with Global Gene Expression Due to Chronic Dietary TCDD Exposure in Juvenile Zebrafish

The goal of this project was to investigate the effects and possible developmental disease implication of chronic dietary TCDD exposure on global gene expression anchored to histopathologic analysis in juvenile zebrafish by functional genomic, histopathologic and analytic chemistry methods. Specifically, juvenile zebrafish were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb, and fish were sampled following 0, 7, 14, 28 and 42 d after initiation of the exposure. TCDD accumulated in a dose- and time-dependent manner and 100 ppb TCDD caused TCDD accumulation in female (15.49 ppb) and male (18.04 ppb) fish at 28 d post exposure. Dietary TCDD caused multiple lesions in liver, kidney, intestine and ovary of zebrafish and functional dysregulation such as depletion of glycogen in liver, retrobulbar edema, degeneration of nasal neurosensory epithelium, underdevelopment of intestine, and diminution in the fraction of ovarian follicles containing vitellogenic oocytes. Importantly, lesions in nasal epithelium and evidence of endocrine disruption based on alternatively spliced vasa transcripts are two novel and significant results of this study. Microarray gene expression analysis comparing vehicle control to dietary TCDD revealed dysregulated genes involved in pathways associated with cardiac necrosis/cell death, cardiac fibrosis, renal necrosis/cell death and liver necrosis/cell death. These baseline toxicological effects provide evidence for the potential mechanisms of developmental dysfunctions induced by TCDD and vasa as a biomarker for ovarian developmental disruption

Efficacy and safety of alirocumab in insulin-treated patients with type 1 or type 2 diabetes and high cardiovascular risk:Rationale and design of the ODYSSEY DM-INSULIN trial

Aims: The coadministration of alirocumab, a PCSK9 inhibitor for treatment of hypercholesterolaemia, and insulin in diabetes mellitus (DM) requires further study. Described here is the rationale behind a phase-IIIb study designed to characterize the efficacy and safety of alirocumab in insulin-treated patients with type 1 (T1) or type 2 (T2) DM with hypercholesterolaemia and high cardiovascular (CV) risk. Methods: ODYSSEY DM-INSULIN (NCT02585778) is a randomized, double-blind, placebo-controlled, multicentre study that planned to enrol around 400 T2 and up to 100 T1 insulin-treated DM patients. Participants had low-density lipoprotein cholesterol (LDL-C) levels at screening. ≥. 70. mg/dL (1.81. mmol/L) with stable maximum tolerated statin therapy or were statin-intolerant, and taking (or not) other lipid-lowering therapy; they also had established CV disease or at least one additional CV risk factor. Eligible patients were randomized 2:1 to 24. weeks of alirocumab 75. mg every 2. weeks (Q2W) or a placebo. Alirocumab-treated patients with LDL-C. ≥. 70. mg/dL at week 8 underwent a blinded dose increase to 150. mg Q2W at week 12. Primary endpoints were the difference between treatment arms in percentage change of calculated LDL-C from baseline to week 24, and alirocumab safety. Results: This is an ongoing clinical trial, with 76 T1 and 441 T2 DM patients enrolled; results are expected in mid-2017. Conclusion: The ODYSSEY DM-INSULIN study will provide information on the efficacy and safety of alirocumab in insulin-treated individuals with T1 or T2 DM who are at high CV risk and have hypercholesterolaemia not adequately controlled by the maximum tolerated statin therapy

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

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

Quantification of the 15 major human bile acids and their precursor 7α-hydroxy-4-cholesten-3-one in serum by liquid chromatography-tandem mass spectrometry

Bile acids are increasingly gaining attention since they were discovered to be activators of the transcription factor farnesoid X receptor (FXR) in addition to their well-established role in dietary lipid emulsification. Moreover, the differential activation potency of bile acids on FXR, which is due to structural variation of the ligands, generates the need for new analytical tools that are sensitive and specific enough to quantify the individual species of this complex class of compounds. Because bile acids undergo enterohepatic circulation, the additional assessment of a bile acid precursor as a marker for bile acid biosynthesis is used to differentiate between newly synthesised bile acids and bile acids reabsorbed from the intestine. This paper describes two new methods using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the quantification of the major unconjugated bile acids in human serum (cholic acid, chenodeoxycholic acid, deoxycholic acid, lithocholic acid and ursodeoxycholic acid) with their glycine- and taurine-conjugates as well as their precursor 7α-hydroxy-4-cholesten-3-one (C4). Intra- and inter-day variation was less than 12% and accuracy was between 84% and 102% for all analytes. Extraction recovery was between 78% and 100% for the bile acids whereas it was 62% for C4 and limit of quantification values ranged from 2nmol/l to 50nmol/l for all compounds. These two methods have the practical advantage of requiring low sample volume (100μl serum for each method) and identical eluents, stationary phase as well as ionisation technique, so that they can be used in a combined way. Moreover, they provide information on the composition of the bile acid pool on one hand and on the relative amount of newly synthesised bile acids on the other, which taken together, gives new insights in the investigation of bile acid metabolism

Variation of sperm length and heteromorphism in drosophilid species

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