Caractérisation du transporteur de nitrate à double affinité, MtNPF6.8 (MtNRT1.3), de Medicago truncatula : rôles dans le transport et la perception du signal nitrate

Nitrate, a major nitrogen source for most plants, is not only a nutrient but also a signaling molecule. However, there are contrasting responses to nitrate between different higher plants. In the model legume Medicago truncatula, nitrate has an inhibitory effect on the primary root growth in post-germination phase. A quantitative genetic study has shown that a nitrate transporter is localized at the peak of a QTL involved in the primary root growth. Functional characterization of the transporter, named MtNRT1.3 and renamed MtNPF6.8, showed that it encodes a dual affinity nitrate transporter. MtNPF6.8 is likely to participate in the nitrate influx in the plant. After obtaining three knockdown lines by RNA interference, experiments using K15NO3 showed that this transporter is effect involved in nitrate influx related to the inducible low affinity transport system (iLATS). However, mutation in MtNPF6.8 does not any effect on nitrogen metabolism. In addition, studies on the primary root growth have confirmed the involvement of the transporter on phenotypic trait. In wild-type plants, cortical cell size decreased after nitrate treatment, showing that primary root growth was due to this reduced cell elongation. The possibility that ABA also plays a role in mediating this nitrate dependent response is heavily favored. All these results, reinforced by a study of mutants expressing this transporter in A. thaliana, indicate that MtNPF6.8 is a nitrate sensor for Medicago in the post-germination phase, independently of its nitrate transport activity

Effects of secondary compounds from cactus and acacias trees on rumen microbial profile changes performed by Real-Time PCR

Plant rich secondary compounds had antimicrobial effects by acting against different rumen microbial populations. The current study investigated the influence of spineless cactus (Opuntia ficus indica f. inermis), Acacia nilotica and A. saligna on rumen microbial fermentation, using in vitro gas production technique, and microbial population profile changes, using a molecular-based technique (Real-Time PCR). The acacias and Opuntia reduced significantly total gas production (p<0.01), rumen CH4 production (p?0.01) and ammonia concentration (p<0.001). At 24h of incubation, Fungi population was 0.30- and 0.03 -fold reduced with A.nilotica and Opuntia as compared to 0h, but 2-and 1.24- fold higher with A.cyanophylla .Increases in the abundance of F.succinogenes were observed in all substrates; however, the tanniferous plants and Opuntia reduced the relative abundance of R.flavefaciens. Methanogenic population was increased with all substrates, except for Opuntia (0. 90- fold lower than the control). There was a significant reduction (p<0.05) in rumen protozoa count with A.cyanophylla, Opuntia and A.nilotica (3.68; 5.59 and 5.34 times, respectively). Results suggested that tannin sources from A.nilotica and A.cyanophylla had an indirect effect on methanogenesis. This study showed an antimicrobial activity of oxalates content of O. ficus indica

Nitrate transporters : an overview in legumes

Main conclusion The nitrate transporters, belonging to NPF and NRT2 families, play critical roles in nitrate signaling, root growth and nodule development in legumes. Nitrate plays an essential role during plant development as nutrient and also as signal molecule, in both cases working via the activity of nitrate transporters. To date, few studies on NRT2 or NPF nitrate transporters in legumes have been reported, and most of those concern Lotus japonicus and Medicago truncatula. A molecular characterization led to the identification of 4 putative LjNRT2 and 37 putative LjNPF gene sequences in L. japonicus. In M. truncatula, the NRT2 family is composed of 3 putative members. Using the new genome annotation of M. truncatula (Mt4.0), we identified, for this review, 97 putative MtNPF sequences, including 32 new sequences relative to previous studies. Functional characterization has been published for only two MtNPF genes, encoding nitrate transporters of M. truncatula. Both transporters have a role in root system development via abscisic acid signaling: MtNPF6.8 acts as a nitrate sensor during the cell elongation of the primary root, while MtNPF1.7 contributes to the cellular organization of the root tip and nodule formation. An in silico expression study of MtNPF genes confirmed that NPF genes are expressed in nodules, as previously shown for L. japonicus, suggesting a role for the corresponding proteins in nitrate transport, or signal perception in nodules. This review summarizes our knowledge of legume nitrate transporters and discusses new roles for these proteins based on recent discoveries

Making Bipedal Robot Experiments Reproducible and Comparable: The Eurobench Software Approach

This study describes the software methodology designed for systematic benchmarking of bipedal systems through the computation of performance indicators from data collected during an experimentation stage. Under the umbrella of the European project Eurobench, we collected approximately 30 protocols with related testbeds and scoring algorithms, aiming at characterizing the performances of humanoids, exoskeletons, and/or prosthesis under different conditions. The main challenge addressed in this study concerns the standardization of the scoring process to permit a systematic benchmark of the experiments. The complexity of this process is mainly due to the lack of consistency in how to store and organize experimental data, how to define the input and output of benchmarking algorithms, and how to implement these algorithms. We propose a simple but efficient methodology for preparing scoring algorithms, to ensure reproducibility and replicability of results. This methodology mainly constrains the interface of the software and enables the engineer to develop his/her metric in his/her favorite language. Continuous integration and deployment tools are then used to verify the replicability of the software and to generate an executable instance independent of the language through dockerization. This article presents this methodology and points at all the metrics and documentation repositories designed with this policy in Eurobench. Applying this approach to other protocols and metrics would ease the reproduction, replication, and comparison of experiments.This study is supported by the European Union’s Horizon 2020 research and innovation program under Grant Agreement no 779963, project Eurobench

Clinical relevance of the first domomedicine platform securing multidrug chronotherapy delivery in metastatic cancer patients at home : the inCASA European project

Background: Telehealth solutions can improve the safety of ambulatory chemotherapy, contributing to the maintenance of patients at their home, hence improving their well-being, all the while reducing health care costs. There is, however, need for a practicable multilevel monitoring solution, encompassing relevant outputs involved in the pathophysiology of chemotherapy-induced toxicity. Domomedicine embraces the delivery of complex care and medical procedures at the patient’s home based on modern technologies, and thus it offers an integrated approach for increasing the safety of cancer patients on chemotherapy. Objective: The objective was to evaluate patient compliance and clinical relevance of a novel integrated multiparametric telemonitoring domomedicine platform in cancer patients receiving multidrug chemotherapy at home. Methods: Self-measured body weight, self-rated symptoms using the 19-item MD Anderson Symptom Inventory (MDASI), and circadian rest-activity rhythm recording with a wrist accelerometer (actigraph) were transmitted daily by patients to a server via the Internet, using a dedicated platform installed at home. Daily body weight changes, individual MDASI scores, and relative percentage of activity in-bed versus out-of-bed (I<O) were computed. Chemotherapy was administered according to the patient medical condition. Compliance was evaluated according to the proportions of (1) patient-days with all data available (full) and (2) patient-days with at least one parameter available (minimal). Acceptability was assessed using the Whole Systems Demonstrator Service User Technology Acceptability Questionnaire. Linear discriminant analysis was used to identify the combination of parameters associated with subsequent unplanned hospitalization. Results: A total of 31 patients (males: 55% [17/31]; World Health Organization Performance Status=0: 29% (9/31); age range: 35-91 years) participated for a median of 58 days (38-313). They received a total of 102 chemotherapy courses (64.7% as outpatients). Overall full compliance was 59.7% (522/874), with at least one data available for 830/874 patient-days (95.0%), during the 30-day per-protocol span. Missing data rates were similar for each parameter. Patients were altogether satisfied with the use of the platform. Ten toxicity-related hospitalizations occurred in 6 patients. The combination of weighted circadian function (actigraphy parameter I<O), body weight change, and MDASI scores predicted for ensuing emergency hospitalization within 3 days, with an accuracy of 94%. Conclusions: Multidimensional daily telemonitoring of body weight, circadian rest-activity rhythm, and patient-reported symptoms was feasible, satisfactory, and clinically relevant in patients on chemotherapy. This domomedicine platform constitutes a unique tool for the further development of safe home-based chemotherapy administration

Early tumour response as a survival predictor in previously- treated patients receiving triplet hepatic artery infusion and intravenous cetuximab for unresectable liver metastases from wild-type KRAS colorectal cancer

Background: Early tumour shrinkage has been associated with improved survival in patients receiving cetuximab-based systemic chemotherapy for liver metastases from colorectal cancer (LM-CRC). We tested this hypothesis for previously treated LM-CRC patients receiving cetuximab (500 mg/m2) and triplet hepatic artery infusion (HAI) within European trial OPTILIV. Methods: Irinotecan (180 mg/m2), 5-fluorouracil (2800 mg/m2) and oxaliplatin (85 mg/m2) were given as chronomodulated or conventional delivery. Patients were retrospectively categorised as early responders (complete or partial RECIST response after three courses) or non-early responders (late or no response). Prognostic factors were determined using multivariate logistic or Cox regression models. Results: Response was assessed in 57 of 64 registered patients (89%), who had previously received one to three prior systemic chemotherapy protocols. An early response occurred at 6 weeks in 16 patients (28%; 9 men, 7 women), aged 33–76 years, with a median of 12 liver metastases (LMs) (2–50), involving five segments (1–8). Ten patients had a late response, and 31 patients had no response. Grade 3–4 fatigue selectively occurred in the non-early responders (0% versus 26%; p = 0.024). Early tumour response was jointly predicted by chronomodulation—odds ratio (OR): 6.0 (1.2–29.8; p = 0.029)—and LM diameter ≤57 mm—OR: 5.3 (1.1–25.0; p = 0.033). Early tumour response predicted for both R0-R1 liver resection—OR: 11.8 (1.4–100.2; p = 0.024) and overall survival—hazard ratio: 0.39 (0.17–0.88; p = 0.023) in multivariate analyses. Conclusions: Early tumour response on triplet HAI and systemic cetuximab predicted for complete macroscopic liver resection and prolonged survival for LM-CRC patients within a multicenter conversion-to-resection medicosurgical strategy. Confirmation is warranted for early response on HAI to guide decision making