Detection of equine atypical myopathy-associated hypoglycin A in plant material: Optimisation and validation of a novel LC-MS based method without derivatisation

Hypoglycin A (HGA) toxicity, following ingestion of material from certain plants, is linked to an acquired multiple acyl-CoA dehydrogenase deficiency known as atypical myopathy, a commonly fatal form of equine rhabdomyolysis seen worldwide. Whilst some plants are known to contain this toxin, little is known about its function or the mechanisms that lead to varied HGA concentrations between plants. Consequently, reliable tools to detect this amino acid in plant samples are needed. Analytical methods for HGA detection have previously been validated for the food industry, however, these techniques rely on chemical derivatisation to obtain accurate results at low HGA concentrations. In this work, we describe and validate a novel method, without need for chemical derivatisation (accuracy = 84–94%; precision = 3–16%; reproducibility = 3–6%; mean linear range R2 = 0.999). The current limit of quantitation for HGA in plant material was halved (from 1μg/g in previous studies) to 0.5μg/g. The method was tested in Acer pseudoplatanus material and other tree and plant species. We confirm that A. pseudoplatanus is most likely the only source of HGA in trees found within European pastures

The role of closed-loop attitude dynamics in adaptive UAV position control

This paper presents the design and the stability analysis of an adaptive position controller for Unmanned Aerial Vehicles (UAVs). Considering a hierarchical control scheme, the novelty of this work is the definition of a systematic approach to design a position controller based on Model Reference Adaptive Control (MRAC) theory taking into account not-fast closed-loop attitude dynamics. After having reformulated the problem considering the attitude dynamics as pseudo-actuator, the authors exploit an existing Linear Matrix Inequality (LMI) based hedging framework designed such that the adaptation performance is not affected by the presence of actuator dynamics. Results from simulations and from experiments on a platform designed to replicate the longitudinal motion of quadrotors are provided to illustrate the performance of the proposed control scheme

Leonardo Drone Contest Autonomous Drone Competition: Overview, Results, and Lessons Learned from Politecnico di Milano Team

In this paper, the Politecnico di Milano solutions proposed for the Leonardo Drone Contest (LDC) are presented. The Leonardo Drone Contest is an annual autonomous drone competition among universities, which has already seen the conclusion of its second edition. In each edition, the participating teams were asked to design and build an autonomous multicopter, capable of accomplishing complex tasks in an indoor urban-like environment. To reach this goal, the designed systems should be capable of navigating in a Global Navigation Satellite System (GNSS)-denied environment with autonomous decision making, online planning and collision avoidance capabilities. In this light, the authors describe the first two editions of the competition, i.e., their rules, objectives and overview of the proposed solutions. While the first edition is presented as relevant for the experience and takeaways acquired from it, the second edition solution is analyzed in detail, providing both the simulation and experimental results obtained

Exploring the role of conformational dynamics in the regulation of tyrosine kinases.

Tyrosine kinases (TKs) are a family of signalling proteins of great pharmaceutical im- portance, as they are involved in the regulation of most cellular pathways. TKs catalytic activity is strictly regulated by conformational changes and post-translational modifi- cations, and their deregulation is involved in numerous human diseases, ranging from cancer to autoimmune diseases. Among tyrosine kinases, Abl and Src are of particular interest for cancer research. The Abl domain in the BCR-Abl fusion protein is the main cause of chronic myeloid leukemia, and it was the target of the first successful anti- leukemic therapy, the powerful kinase inhibitor imatinib. We now know that imatinib effectively inhibits BCR-Abl, as well as Kit and Lck kinases, by binding to a specific inactive state, in which the conserved Asp-Phe-Gly motif (DFG) assumes a peculiar "out" conformation. Still, there are many questions on its mode of action. For instance, other TKs with an extended identity with Abl (such as Src, which has 45% sequence identity) bind much less strongly to imatinib, in spite of very similar binding mode. Moreover, the mode of action of drug-resistant mutations that induce imatinib resis- tance and cause an increasing number of relapses in patients under treatment, is still poorly understood. Understanding the molecular mechanisms responsible for the ob- served differences in imatinib activity, is essential for the development of new selective anticancer drugs. In this thesis, by using computational and experimental approaches, I have investigated the reasons leading to drug resistance and the differential binding affinity in homologous TKs. A combination of enhanced sampling molecular dynam- ics simulations (such as parallel tempering metadynamics or PTmetaD) were used to reconstruct and compare the free energy landscape associated with the relevant con- formational changes. Mutagenesis and isothermal titration calorimetry were used to validate the computational results

Nonlinear refractive index and three-photon absorption coefficient of poly(9,9-dioctylfluorence)

We investigate the optical Kerr effect and third harmonic generation (THG) arising from chi((3)) of poly(9,9-dioctylfluorence), which is an emerging organic pi-conjugated polymer from the perspective of diverse optoelectronic applications. The measured nonlinear refractive index, obtained with closed-aperture Z-scan, is n(2)=(2.04 +/- 0.10)x10(-12) esu at lambda=1540 nm. Open-aperture Z-scan yields the three-photon absorption coefficient of gamma=(1.88 +/- 0.26)x10(-3) cm(3)/GW(2) at lambda=1064 nm, arising from chi((5)) response. The wavelength-dependent THG indicates that this semiconducting polymer can be a potentially useful polymer system for nonlinear-optics applications involving high-order optical processes in the mid-IR range. (C) 2009 American Institute of Physics. (doi:10.1063/1.3269588

Antimicrobial resistance, an update from the ward: Increased incidence of new potential pathogens and site of infection-specific antibacterial resistances

In order to monitor the spread of antimicrobial resistance, the European Union requires hospitals to be equipped with infection control centers. With this aim, we analyzed 1583 bacterial strains isolated from samples of different origin from patients with community-onset and nosocomial infections in a public tertiary University Hospital on the outskirts of Turin, Italy. Statistical analyses of the isolates (source, type) and their antimicrobial resistance (AMR) were performed. The survey revealed infections associated with bacterial species considered as not-commensal and not-pathogenic, hence potentially emerging as new threats for human health. Conversely to the general observation of nosocomial strains being more resistant to antibiotics compared to community-acquired strains, nosocomial strains isolated in this study were more resistant only to 1/42 tested antibiotics (tetracycline). By adopting an ecological approach, we observed that blood infections are associated with the broadest range of species compared to infections affecting other areas and we obtained clear indications on the antibiotics that should be preferred in the treatment of infections at specific body sites. Future investigations carried out on a larger geographical scale will clarify whether these indications are limited to the geographical region investigated over this study, or whether the same trends are visible at national or international level

Spatial Correlation Of Productive Component For Peach Palm Crop And Some Physical Attributes Of Eutrochrept Soil

Currently, Brazil sells around 300 million dollars per year of peach palms (Bactris gasipaes), wherein this country is responsible for being the largest worldwide producer, exporter and consumer. In crop year of 2014, productive components of peach palms were analyzed according to soil physical properties in Registro, SP, Brazil. The objectives were to evaluate the variability of the soil attributes and define a linear and spatial correlation between the crop productive components and the soil physical properties. Geostatistical grid was installed to collect data from soil and plant, with 54 sampling points in a total area of approximately 10,000 m2. With regard to linear point of view, stem diameter and palm height was explained by direct and exponential potential model, which was highly significant due to mechanical resistance to penetration.11316317