No wavefront sensor adaptive optics system for compensation of primary aberrations by software analysis of a point source image. 1. Methods

Adaptive optics (AO) has been recently used for the development of ophthalmic devices. Its main objective has been to obtain high-resolution images for diagnostic purposes or to estimate high-order eye aberrations. The core of every AO system is an optical device that is able to modify the wavefront shape of the light entering the system; if you know the shape of the incoming wavefront, it is possible to correct the aberrations introduced in the optical path from the source to the image. The aim of this paper is to demonstrate the feasibility, although in a simulated system, of estimating and correcting an aberrated wavefront shape by means of an iterative gradient-descent-like software procedure, acting on a point source image, without expensive wavefront sensors or the burdensome computation of the point-spread-function (PSF) of the optical system. In such a way, it is possible to obtain a speed and repeatability advantage over classical stochastic algorithms. A hierarchy in the aberrations is introduced, in order to reduce the dimensionality of the state space to be searched. The proposed algorithm is tested on a simple optical system that has been simulated with ray-tracing software, with randomly generated aberrations, and compared with a recently proposed algorithm for wavefront sensorless adaptive optics.     

Yeasts from Colombian Kumis as source of peptides with Angiotensin I converting enzyme (ACE) inhibitory activity in milk

This study investigated the possibility of using yeast strains in fermented milks to obtain products with high Angiotensin I-converting enzyme (ACE) inhibitory activity and low bitter taste. Ninety-three yeast strains isolated from Colombian Kumis in different geographic regions were molecularly identified, and their milk fermentation performances were determined. Molecular identification evidenced that Galactomyces geotrichum, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis, were the dominant species. Eighteen out of 93 strains produced fermented milk with ACE-inhibitory (ACEI) activity values ranging from 8.69 to 88.19%. Digestion of fermented milk samples by pepsin and pancreatin demonstrated an increase in ACEI activity, with C. lusitaniae KL4A as the best producer of ACEI peptides. Moreover, sensory analysis of the products containing the major ACE-inhibitory activity pointed out that P. kudriavzevii KL84A and Kluyveromyces marxianus KL26A could be selected as potential adjunct starter cultures in Kumis, since they made a considerable contribution to the ACE inhibitory activity and produced fermented milk without bitter taste. In this study we observed that Colombian Kumis can be an excellent vehicle for the isolation of yeasts with a potential to enhance bioactive peptides produced during milk fermentation.     

Influence of water activity and molecular mobility on peroxidase activity in salt and sorbitol-maltodextrin systems

Solvent composition, system mobility and viscosity play a central role in the regulation of enzymatic activity.The aim of this study was to investigate the individual and combined effect of water activity (a_w), bulk viscosity and glass transition temperature () on the activity of horseradish peroxidase (HRP) in buffered solutions. For this purpose, the water activity of the solutions was modulated using both a ionic (sodium chloride) and a non-ionic (sorbitol) ligand and viscosity changed upon the addition of maltodextrin.In viscous solutions characterized by different compositions, the effectiveness of a solute in the inhibition of the HRP activity was dependent both on the chemical properties of the solution, as described by a_w, and on the mobility of the system, as described by the inverse of viscosity and T − . Viscosity was the most important factor in the inhibition of HRP activity in solutions characterized by the same value, but when was changed, due to changes in the solutes composition, the latter became a key factor in the regulation of the enzyme activity.In salt-maltodextrin systems the water activity reduction limited HRP activity with higher efficiency at low viscosities whilst in sorbitol-maltodextrin systems, characterised by different values, the a_w lowering by sorbitol addition resulted in the increase of HRP activity depending on its effect on .     

Assessment of the autonomic control of heart rate variability in healthy and spinal-cord injured subjects: contribution of different complexity-based estimators

We investigated how complexity-based estimators of heart rate variability can detect changes in cardiovascular autonomic drive with respect to traditional measures of variability. This was done by analyzing healthy subjects and paraplegic patients with different autonomic impairment due to low (vascular impairment only) or high (cardiac and vascular impairment) spinal cord injury, during progressive autonomic activations. While traditional techniques only quantified the effects of the autonomic activation, not distinguishing the effects of the lesion level, some recently proposed complexity estimators could also reveal the pathologic alterations in the autonomic control of heart rate. These estimators included the detrended fluctuation analysis coefficient (sensitive to both low and high autonomic lesions), sample entropy (sensitive to low-level lesions) and the largest Lyapunov exponent (sensitive to high-level lesions). Thus complexity-based methods provide information on the autonomic function from the heart rate dynamics that cannot be obtained by traditional techniques. This finding supports the combined use of both complexity-based and traditional methods to investigate the autonomic cardiovascular control from a more comprehensive perspective.     

Quasi-null lens optical system for the fabrication of an oblate convex ellipsoidal mirror: application to the Wide Angle Camera of the Rosetta space mission

The design of a quasi-null lens system for the fabrication of an aspheric oblate convex ellipsoidal mirror is presented. The Performance and tolerance of the system have been analyzed. The system has been applied successfully for the fabrication of the primary mirror of the Wide Angle Camera (WAC), the imaging system onboard the Rosetta, the European Space Agency cornerstone mission dedicated to the exploration of a comet. The WAC is based on an off-axis two-mirror configuration, in which the primary mirror is an oblate convex ellipsoid with a significant conic constant.     

Development and Validation of a Method for the Determination of Quinolones in Muscle and Eggs by Liquid Chromatography-Tandem Mass Spectrometry

In this study, the development and validation of a multiresidue method for the detection of 11 quinolones (marbofloxacin, norfloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, nalidixic acid, flumequine) in muscle and eggs were reported. The method involved an extraction with a methanol/metaphosphoric acid mixture and a clean up by Oasis hydrophilic-lipophilic balance (HLB) cartridge. The validation was performed according to the Commission Decision 2002/657/EC. Linearity, specificity, decision limit (CCα), detection capability (CCβ), recovery, precision (repeatability and within-laboratory reproducibility), and ruggedness were determined. Depending on the analytes, CCα and CCβ ranged from 113 to 234 μg/kg and from 126 to 282 μg/kg in muscle samples, whereas in eggs, these parameters were between 5.6 and 7.4 μg/kg and between 6.1 and 9.8 μg/kg, respectively. In both the examined matrices, the recovery values were always higher than 90 % and precision, calculated as relative standard deviation, was equal to or lower than 16 % for repeatability and 23 % for within-laboratory reproducibility. The described method can be considered adequate for the simultaneous determination and quantification of quinolones in the tested food matrices.     

No Time to Die: How Kidney Cancer Evades Cell Death

The understanding of the pathogenesis of renal cell carcinoma led to the development of targeted therapies, which dramatically changed the overall survival rate. Nonetheless, despite innovative lines of therapy accessible to patients, the prognosis remains severe in most cases. Kidney cancer rarely shows mutations in the genes coding for proteins involved in programmed cell death, including p53. In this paper, we show that the molecular machinery responsible for different forms of cell death, such as apoptosis, ferroptosis, pyroptosis, and necroptosis, which are somehow impaired in kidney cancer to allow cancer cell growth and development, was reactivated by targeted pharmacological intervention. The aim of the present review was to summarize the modality of programmed cell death in the pathogenesis of renal cell carcinoma, showing in vitro and in vivo evidence of their potential role in controlling kidney cancer growth, and highlighting their possible therapeutic value.     

Superconducting Nb3Sn diffusion layers

In the present work an experimental apparatus for the production of Nb₃Sn superconducting ribbon is described. The fabrication method for these ribbons takes advantage of the diffusion process of tin into niobium. We give also some details of the technique by which the superconducting properties of Nb₃Sn have been tested. A number of preliminary experimental results are discussed with the purpose of pointing out the main fabrication parameters which influence the superconducting properties. Finally future developments of this research program are outlined.     

The General Product Machine: a New Model for Symbolic FSM Traversal

Proving the equivalence of two Finite State Machines (FSMs) has many applications to synthesis, verification, testing, and diagnosis. Building their product machine is a theoretical framework for equivalence proof. There are some cases where product machine traversal, a necessary and sufficient check, is mandatory. This is much more complex than traversing just one of the component machines. This paper proposes an equivalence-preserving function that transforms the product machine in theGeneral Product Machine (GPM). Using the GPM in symbolic state space traversal reduces the size of the BDDs and makes image computation easier. As a result, GPM traversal is much less expensive than product machine traversal, its cost being close to dealing with a single machine.