Effect of temperature and water activity on growth and ochratoxin A production boundaries of two Aspergillus carbonarius isolates on a simulated grape juice medium

Aims: To develop and validate a logistic regression model to predict the growth and ochratoxin A (OTA) production boundaries of two Aspergillus carbonarius isolates on a synthetic grape juice medium as a function of temperature and water activity (aw)

Human tRNAGlu genes: their copy number and organisation

AbstractThe tRNAGlu gene copy number, determined by genomic blot analysis of human plaeental DNA, is approximately thirteen. These studies, using several probes and DNA digested with several restriction enzymes singly or in combination, show that most of these tRNAGlu genes are flanked by DNA of very similar sequence for at least 5 kb. This conclusion is supported by the close similarity of the restriction maps of two λ Charon-4A recombinants of human genomic DNA containing two different tRNAglu genes

Nanotechnology‐Based Rapid Diagnostic Tests

Recently, various nanomaterials are used in order to develop nanotechnology‐based rapid diagnostic tests, such as metallic nanoparticles, quantum dots (QDs), silica nanospheres, magnetic nanoparticles, carbon nanotubes (CNTs), silicon nanowires (SiNWs), nanopores, graphene, nanostructured surfaces, and metal films. This novel nanodiagnostic approach will further develop point‐of‐care (POC) diagnostics and monitoring technologies. Nanobiosensors and microarrays of biosensors can create biochip systems and microfluidic platforms that are the most used nanofabrications for rapid diagnostic tests. These nanoplatforms are constructed for the rapid detection of various diseases or pathogen‐specific biomolecules/markers, such as DNA, proteins, whole cells (e.g., circulating tumor cells), and others. The fabrication of small‐scale portable devices with the incorporation of nanostructures will offer many advantages in the early detection of various diseases and health‐threatening infections by pathogens and in the treatment selection and treatment monitoring. The use of nanostructures in in vitro diagnostics gives the opportunity to augment the sensitivity and specificity required in clinical practice, lowers the cost and test time of the assays, and enables portable microfluidic platforms suitable for resource‐constrained settings. In this chapter, all the state‐of‐the‐art advantages in this field are discussed, starting with the nanostructures used for the fabrication of nanobiosensors, nanobiosensors arrays, and nanofluidic platforms and the nanodiagnostic use of rapid tests in the detection of pathogens, in cancer management, and glucose monitoring for the management of diabetes disease

Optimal control of motorsport differentials

Modern motorsport limited slip differentials (LSD) have evolved to become highly adjustable, allowing the torque bias that they generate to be tuned in the corner entry, apex and corner exit phases of typical on-track manoeuvres. The task of finding the optimal torque bias profile under such varied vehicle conditions is complex. This paper presents a nonlinear optimal control method which is used to find the minimum time optimal torque bias profile through a lane change manoeuvre. The results are compared to traditional open and fully locked differential strategies, in addition to considering related vehicle stability and agility metrics. An investigation into how the optimal torque bias profile changes with reduced track-tyre friction is also included in the analysis. The optimal LSD profile was shown to give a performance gain over its locked differential counterpart in key areas of the manoeuvre where a quick direction change is required. The methodology proposed can be used to find both optimal passive LSD characteristics and as the basis of a semi-active LSD control algorithm

Semi-global Exponential Stability for Dual Quaternion Based Rigid-Body Tracking Control

Semi-Global Exponential Stability (SGES) is proved for the combined attitude and position rigid body motion tracking problem, which was previously only known to be asymptotically stable. Dual quaternions are used to jointly represent the rotational and translation tracking error dynamics of the rigid body. A novel nonlinear feedback tracking controller is proposed and a Lyapunov based analysis is provided to prove the semi-global exponential stability of the closed-loop dynamics. Our analysis does not place any restrictions on the reference trajectory or the feedback gains. This stronger SGES result aids in further analyzing the robustness of the rigid body system by establishing Input-to-State Stability (ISS) in the presence of time-varying additive and bounded external disturbances. Motivated by the fact that in many aerospace applications, stringent adherence to safety constraints such as approach path and input constraints is critical for overall mission success, we present a framework for safe control of spacecraft that combines the proposed feedback controller with Control Barrier Functions. Numerical simulations are provided to verify the SGES and ISS results and also showcase the efficacy of the proposed nonlinear feedback controller in several non-trivial scenarios including the Mars Cube One (MarCO) mission, Apollo transposition and docking problem, Starship flip maneuver, collision avoidance of spherical robots, and the rendezvous of SpaceX Dragon 2 with the International Space Station.Comment: 25 page

Signal-to-noise per unit time optimization for in vivo single-voxel proton magnetic resonance spectroscopy of the brain: Theoretical formulation and experimental verification at two field strengths

Signal-to-noise ratio optimization, regarding repetition time selection, was explored mathematically and experimentally for single-voxel proton magnetic resonance spectroscopy. Theoretical findings were benchmarked against phantom measurements at 1.5 Tesla and localized in vivo proton brain spectra acquired at both 1.5 Tesla/3.0 Tesla. A detailed mathematical description of signal-to-noise ratio per unit time was derived, yielding an optimal repetition time of 1.256 times the metabolite longitudinal relaxation time. While long-repetition-time acquisitions minimize longitudinal relaxation time contributions, a repetition time of ~1.5s results in maximum signal-to-noise ratio per unit time, which can in turn be invested into smaller voxel sizes. The latter is of utmost importance in brain oncology, allowing accurate spectroscopic characterization of small lesions.Comment: 26 pages, 4 figures, submitted to Spectroscopy Letter

A Systems Engineering Approach to Integrated Structural Health Monitoring For Aging Aircraft

The United States Air Force and many of its Coalition partners have extended the original service life of some of their aging aircraft due to fiscal constraints. This life extension often requires increased periodic and in-depth inspections; increasing maintenance costs and resulting in longer periods of aircraft downtime. A structural health monitoring system for aging aircraft could reduce the current inspection burden, and thus decrease costs and system downtime. This presentation describes a baseline systems engineering methodology for system definition of an aging aircraft structural health monitoring system. Analysis was performed to quantify the potential benefit a structural health monitoring affords

Αξιολόγηση συστημάτων εξατμιστικής ψύξης ανοικτού και κλειστού κύκλου

116 σ.Στην παρούσα εργασία θα μελετηθούν δύο συστήματα εξατμιστικής ψύξης, ένα ανοικτού και ένα κλειστού κύκλου. Τα δύο συστήματα έχουν προσεγγιστεί κατά τη μοντελοποίηση, τον υπολογισμό και την προσομοίωση με τέτοιο τρόπο ώστε να εξαχθούν συμπεράσματα τόσο ως προς τις δύο τεχνολογίες αλλά και τον τρόπο υλοποίησης. Φυσικά και οι λύσεις δεν είναι μονοσήμαντες αλλά εμπεριέχουν το στοιχείο της έρευνας και της κρίσης του μελετητή. Η παρούσα εργασία αποτελεί περισσότερο μια πρώτη προσέγγιση για περαιτέρω βελτίωση παρά τη βέλτιστη τεχνοοικονομική λύση. Για το σκοπό αυτό χρησιμοποιήθηκε το λογισμικό TRNSYS στην έκδοση 16.00.0038 εξοπλισμένο με τη βιβλιοθήκη TESS και τα κλιματικά δεδομένα Meteonorm για την Ευρώπη. Το προς μελέτη κτίριο είναι ένα τετραόροφο ξενοδοχείο θερινής περιόδου που έχει μοντελοποιηθεί με το λογισμικό TRNBuild στην έκδοση 1.0.84.In this work we studied two systems of evaporative cooling, an open and a closed circle. Both systems have been approached by modeling, calculation and simulation in such a way as to draw conclusions as to the two technologies and how to implement. Of course the solutions are not unambiguous, but involve an element of research and crisis consultant. This work is more a first approach to further improve despite the best techno-economic solution. For this purpose is used TRNSYS software to version 16.00.0038 equipped with library TESS and Meteonorm climate data for Europe. The building to study is a four-storey summer period hotel and is modeled with the software TRNBuild in version 1.0.84Ευστάθιος Π. Παπαστάθη

Monitoring the growth of Salmonella enterica serovar typhimurium in silico and in situ with a view in gene expression

In the present study, the ability of S. Typhimurium to develop a biofilm community on rocket tissue was investigated at 20°C. The differences on expression of genes associated with several functional roles during growth of S. Typhimurium on rocket extract and rocket tissue regarding a laboratory growth medium (Luria – Bertani broth, LB) was also monitored. The findings of the present study could show that Salmonella reacts as exposed to different types of stress when inoculated to a heat sterile plant extract and plant tissue. However, further studies are needed to better determine the survival and / or growth of these as “real” biofilm cells on plant tissues