Aids for color vision deficiency: introduction to the feature issue.

Approximately 8% of Caucasian males and 0.5% of females have congenital red-green color vision deficiencies (CVD), and a number of eye diseases are accompanied by acquired CVD. This feature issue includes ten contributions regarding existing and proposed algorithms and devices intended to help CVD subjects compensate for their color deficiencies. It also addresses limitations in the effectiveness of CVD aids for subjects with different types and degrees of color vision deficiency.

CVD-MET: an image difference metric designed for analysis of color vision deficiency aids.

Color vision deficiency (CVD) has gained in relevance in the last decade, with a surge of proposals for aid systems that aim to improve the color discrimination capabilities of CVD subjects. This paper focuses on the proposal of a new metric called CVD-MET, that can evaluate the efficiency and naturalness of these systems through a set of images using a simulation of the subject's vision. In the simulation, the effect of chromatic adaptation is introduced via CIECAM02, which is relevant for the evaluation of passive aids (color filters). To demonstrate the potential of the CVD-MET, an evaluation of a representative set of passive and active aids is carried out both with conventional image quality metrics and with CVD-MET. The results suggest that the active aids (recoloration algorithms) are in general more efficient and produce more natural images, although the changes that are introduced do not shift the CVD's perception of the scene towards the normal observer's perception.

Do EnChroma glasses improve color vision for colorblind subjects?

The commercialization of EnChroma glasses has generated great expectations for people to be able to see new colors or even correct color vision deficiency (CVD). We evaluate the effectiveness of these glasses using two complementary strategies for the first time. The first consists of using the three classical types of tests - recognition, arrangement and discrimination - with and without glasses, with a high number of individuals. In the second, we use the spectral transmittance of the glasses to simulate the appearance of stimuli in a set of scenes for normal observers and observers with CVD. The results show that the glasses introduce a variation of the perceived color, but neither improve results in the diagnosis tests nor allow the observers with CVD to have a more normal color vision.

Electrochemical detection of extracellular hydrogen peroxide in Arabidopsis thaliana: a real-time marker of oxidative stress.

An electrochemical approach to directly measure the dynamic process of H2 O2 release from cultures of Arabidopsis thaliana cells is reported. This approach is based on H2 O2 oxidation on a Pt electrode in conjunction with continuous measurement of sample pH. For [H2 O2 ] <1 mm, calibration plots were linear and the amperometric response of the electrode was maximum at pH 6. At higher concentrations ([H2 O2 ] >1 mm), the amperometric response can be described by Michaelian-type kinetics and a mathematical expression relating current intensity and pH was obtained to quantitatively determine H2 O2 concentration. At pH 5.5, the detection limit of the sensor was 3.1 µm (S/N = 3), with a response sensitivity of 0.16 Am(-1 ) cm(-2) and reproducibility was within 6.1% in the range 1-5 × 10(-3 ) m (n = 5). Cell suspensions under normal physiological conditions had a pH between 5.5-5.7 and H2 O2 concentrations in the range 7.0-20.5 µm (n = 5). The addition of exogenous H2 O2 , as well as other potential stress stimuli, was made to the cells and the change in H2 O2 concentration was monitored. This real-time quantitative H2 O2 analysis is a potential marker for the evaluation of oxidative stress in plant cell cultures.

Impact of Zulla cover crop in vineyard on the musts volatile profile of Vitis vinifera L. cv Syrah.

Grape aromatic characteristics are very important for producing quality wines. There have been very few studies on concentrations of volatile compounds in grape berries from vines with cover crops. For this reason, the aim of this work was to evaluate the influence of "Zulla" cover crop on the volatile profiles of organically grown Syrah variety grapes. For this purpose, volatile profiles of grapes obtained from vines with three different amounts of cover crop (one line, two lines, and four lines) and without cover crop, over three harvests (2019, 2020, and 2021) were determined. Moreover, a comparative study of conventional and organic crops, both submitted to soil tillage, was performed. The grape samples came from a warm climate zone. Must volatile compounds were determined by sequential sorptive extraction with Twisters by immersion (SBSE) and headspace (HSSE), followed by GC-MS analysis. A total of 160 compounds were determined and most of them were influenced by the presence of cover crop. However, the results showed an important influence of the harvest year over agronomic practices. Therefore, organic cultivation using Zulla cover crop seems to be a suitable tool for the implementation of friendly ecosystem management in a warm climate Syrah vineyard.

Isotopic labelling-based analysis elucidates biosynthesis pathways in Saccharomyces cerevisiae for Melatonin, Serotonin and Hydroxytyrosol formation.

Yeasts can synthetise bioactive compounds such as Melatonin (MEL), Serotonin (SER) and Hydroxytyrosol (HT). Deciphering the mechanisms involved in their formation can lead to exploit this fact to increase the bioactive potential of fermented beverages. Quantitative analysis using labelled compounds, 15-N2 l-tryptophan and 13-C tyrosine, allowed tracking the formation of the above-mentioned bioactive compounds during the alcoholic fermentation of synthetic must by two different Saccharomyces cerevisiae strains. Labelled and unlabelled MEL, SER and HT were undoubtedly identified and quantified by High Resolution Mass Spectrometry (HRMS). Our results prove that there are at least two pathways involved in MEL biosynthesis by yeast. One starts with tryptophan as precursor being known for the vertebrates' pathway. Additionally, MEL is produced from SER which in turn is consistent with the plants' biosynthesis pathway. Concerning HT, it can be formed both from labelled tyrosine and from intermediates of the Erlich pathway.

Fluorescence decrease of conjugated polymers by the catalytic activity of horseradish peroxidase and its application in phenolic compounds detection.

We report the fluorescence decrease of the water-soluble π-π-conjugated polymer poly(2-methoxy-5-propyloxy sulfonate phenylene vinylene, MPS-PPV) by the catalytic activity of horseradish peroxidase in the presence of H(2)O(2). MPS-PPV acts as a donor substrate in the catalytic cycle of horseradish peroxidase where the electron-deficient enzymatic intermediates compounds I and II can subtract electrons from the polymer leading to its fluorescence decrease. The addition of phenolic drug acetaminophen to the former solution favors the decrease of the polymer fluorescence, which indicates the peroxidase-catalyzed co-oxidation of MPS-PPV and acetaminophen. The encapsulation of horseradish peroxidase within polyacrylamide microgels allows the isolation of intermediates compound I and compound II from the polymer, leading to a fluorescence decrease that is only due to the product of biocatalytic acetaminophen oxidation. This system could be used to develop a new device for phenolic compounds detection.

[Mild encephalitis/encephalopathy with a reversible splenial corpus callosum lesion (MERS)]. / Encefalitis/encefalopatía leve con lesión reversible del esplenio del cuerpo calloso (MERS).

INTRODUCTION: Mild encephalitis/encephalopathy with a reversible isolated splenial corpus callosum lesion (MERS) is a clinical-radiological syndrome characterized by a lesion in the center of the splenium identified by magnetic resonance imaging (MRI), the imaging test of choice. CASE REPORT: A 31-year-old man is admitted with fever, intense hemicranial headache, disorientation, dysarthria and paresthesia in the lips and both upper extremities is presented; and that he is admitted for a suspected diagnosis of viral encephalitis. The cerebrospinal fluid analysis shows an elevation of proteins and the electroencephalogram shows generalized slowing, predominantly on the left. MRI shows a well-defined ovoid lesion, isolated in the splenium of the corpus callosum, homogeneous and hyperintense on T2 and FLAIR, with restriction to fluid diffusion and without uptake after gadolinium administration. The patient received empirical treatment with acyclovir and corticosteroids, with good subsequent evolution and disappearance of the lesion described in the control MRI at 3 weeks. CONCLUSION: MERS is a benign, infrequent entity of unknown pathogenesis, which must be differentiated from other pathologies that present with lesions of the corpus callosum, but with an unfavorable prognosis.

TITLE: Encefalitis/encefalopatía leve con lesión reversible del esplenio del cuerpo calloso (MERS).Introducción. La encefalitis/encefalopatía leve con lesión reversible aislada del esplenio del cuerpo calloso (MERS) es un síndrome clinicorradiológico caracterizado por una lesión en el centro del esplenio identificada por resonancia magnética, prueba de imagen de elección. Caso clínico. Se presenta el caso de un varón de 31 años con cuadro de fiebre, cefalea intensa hemicraneal, desorientación, disartria y parestesias en los labios y en ambas extremidades superiores, y que ingresa por sospecha diagnóstica de encefalitis vírica. El análisis del líquido cefalorraquídeo muestra una elevación de proteínas y el electroencefalograma manifiesta una lentificación generalizada de predominio izquierdo. La resonancia magnética evidencia una lesión ovoidea, bien delimitada, aislada en el esplenio del cuerpo calloso, homogénea e hiperintensa en T2 y FLAIR, con restricción a la difusión hídrica y sin captación tras la administración de gadolinio. El paciente recibe tratamiento de forma empírica con aciclovir y corticoesteroides, con buena evolución posterior y desaparición de la lesión descrita en la resonancia magnética de control a las tres semanas. Conclusión. La MERS es una entidad benigna, infrecuente y de patogenia desconocida, que debe diferenciarse de otras patologías que cursan con lesiones del cuerpo calloso en las que el pronóstico es desfavorable.

Volatile metabolites produced by different flor yeast strains during wine biological ageing.

Sherry white wine called Fino is produced by dynamic biological ageing under the action of flor yeasts using traditional practices aimed at ensuring uniform quality and characteristics over time. These kinds of yeasts provide typical sensory properties to Fino wines. Although there are studies of the volatile composition of these wines submitted to biological ageing in wood barrels, there is a lack of knowledge on the particular volatile profile produced by different flor yeast strains from Sherry zone wineries. For this reason, the aim of this study was to analyse the volatile profiles produced by 15 pure culture flor velum yeasts, with the goal of observing their suitability for obtaining high quality Fino sherry wines. Volatile composition was determined by dual sequential stir bar sorptive extraction, followed by GC-MS analysis. All yeast strains studied produced the increase of most acetals, highlighting acetaldehyde diethylacetal which was the compound that most increased. Among terpenes, nerolidol and farnesol underwent remarkable increases. However, results showed that in a month of biological ageing, significant differences were observed among the volatile metabolites produced by flor yeast strains studied. Only some of them stood out for their high production of volatile compounds characteristic of Sherry Fino wines, which are good candidates for producing starter cultures.