The fungus Ustilago maydis, from the aztec cuisine to the research laboratory

Ustilago maydis is a plant pathogen fungus responsible for corn smut. It has a complex life cycle. In its saprophitic stage, it grows as haploid yeast cells, while in the invasive stage it grows as a mycelium formed by diploid cells. Thus, a correlation exists between genetic ploidy, pathogenicity and morphogenesis. Dimorphism can be modulated in vitro by changing environmental parameters such as pH. Studies with auxotrophic mutants have shown that polyamines play a central role in regulating dimorphism. Molecular biology approaches are being employed for the analysis of fundamental aspects of the biology of this fungus, such as mating type regulation, dimorphism or cell wall biogenesis

Design and in Vitro Evaluation of a New Nano-Microparticulate System for Enhanced Aqueous-Phase Solubility of Curcumin

Curcumin, a yellow polyphenol derived from the turmeric Curcuma longa, has been associated with a diverse therapeutic potential including anti-inflammatory, antioxidant, antiviral, and anticancer properties. However, the poor aqueous solubility and low bioavailability of curcumin have limited its potential when administrated orally. In this study, curcumin was encapsulated in a series of novel nano-microparticulate systems developed to improve its aqueous solubility and stability. The nano-microparticulate systems are based entirely on biocompatible, biodegradable, and edible polymers including chitosan, alginate, and carrageenan. The particles were synthesized via ionotropic gelation. Encapsulating the curcumin into the hydrogel nanoparticles yielded a homogenous curcumin dispersion in aqueous solution compared to the free form of curcumin. Also, the in vitro release profile showed up to 95% release of curcumin from the developed nano-microparticulate systems after 9 hours in PBS at pH 7.4 when freeze-dried particles were used.CONACYTCUPIAPharmac

Spanish radiographers’ concerns about the COVID-19 pandemic

Introduction: The current outbreak of COVID-19 has caused worldwide healthcare and social emergency in which healthcare professionals were under extreme work conditions while being fearful of becoming infected or spreading the disease to their relatives. The perceived threat of COVID-19 has the potential to cause severe psychological maladjustment. The aim of the study is to explore Spanish radiographers' concerns about the COVID-19 pandemic. Methods: This study was quantitative, observational and cross-sectional. The sample was made up of 546 radiographers working in Spain during the outbreak. The instrument used for analysis was an ad hoc questionnaire with socio-demographic questions and the questionnaire on perception of threat from COVID-19 validate to spanish healthcare professionals. Results: The sample consisted of 70.1% of female, 29.7% of male and 0.2% undeclare sex participants. The results showed a high level of a perceived threat from COVID-19 (7.57 ± 0.088), furthermore we observed a high level of threat about the possibility of infecting family members (8.49 ± 0.25), patients (8.33 ± 0.086), and coworkers (8.35 ± 0.084). Furthermore, females have a higher level of a perception of threat to spread infection between patients (r = -0.136; p = 0.001) and coworkers (r = -0.118; p = 0.006), than males. Conclusion: COVID-19 pandemic is perceived as a serious threat, being especially concerned about the threat of spreading the infection to family, coworkers, and patients. The perception of risk depends partly on professionals' gender and family responsibilities. Implications for practice: Our findings suggest that it is recommended that healthcare professionals receive formation to reinforce and improve their emotional competencies for coping successfully with potentially stressful situations like COVI19 pandemic

Modelling the behaviour of microbulk Micromegas in Xenon/trimethylamine gas

We model the response of a state of the art micro-hole single-stage charge amplication device (`microbulk' Micromegas) in a gaseous atmosphere consisting of Xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 um-side equilateral-triangle pattern with 50 um-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 um-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elementary cross-sections. We show that achieving a satisfactory description needs additional assumptions about atom-molecule (Penning) transfer reactions and charge recombination to be made

Use of PCR to detect infection of differentially susceptible maize cultivars using Ustilago maydis strains of variable virulence

Ustilago maydis was specifically detected in infected maize plants by means of the polymerase chain reaction (PCR) using oligonucleotides corresponding to a specific region downstream of the homeodomain of the bE genes of the pathogen. The reaction gave rise to amplification of a ca. 500-bp product when tested with U. maydis DNA, but no amplification was detected with DNA from fungi not related to U. maydis. Using these primers, U. maydis was detected in infected maize plants from differentially susceptible cultivars as early as 4 days after inoculation with strains of variable degrees of virulence. Detection of U. maydis at early stages of infection, or in asymptomatic infected plants should assist in studies on plant–pathogen interactions

Scanner image methodology (SIM) to measure dimensions of leaves for agronomical applications

A scanner image methodology was used to determine plant dimensions, such as leaf area, length and width. The values obtained using SIM were compared with those recorded by the LI-COR leaf area meter. Bias, linearity, reproducibility and repeatability (R&R) were evaluated for SIM. Different groups of leaves were scanned and measured. R&R studies showed that, the lowest SIM’s resolution was nineteen categories. SIM’s R&R ANOVA showed the method’s measurement error was not significant. In the image processing method, the color image was converted to gray scale over the green band and it was segmented using Otsu methodology. The noise produced was cleaned with a median filter. The leaf image was rotated to align the longest parallel line to y-axis or x-axis using central moments. From the centroid using directional erosions the leaf width and length were obtained and recorded.Key words: Leaf area, width, length, digital image analysis, segmentation

Short communication: Performance, intestinal permeability, and metabolic profile of calves fed a milk replacer supplemented with glutamic acid

The objective of this study was to evaluate the potential benefits of supplementing glutamic acid in milk replacers (MR) with respect to calf performance, intestinal permeability, and metabolism. Sixty Holstein male calves (3 ± 1.3 d old and 45 ± 5.9 kg body weight) were individually housed and fed a control MR without AA supplementation (24.8% crude protein and 19.1% fat, dry matter basis), or MR supplemented with 0.3% glutamic acid (25.1% crude protein and 20.3% fat, dry matter basis). Animals followed the same MR feeding program and were weaned at 56 d of the study. The amount of starter concentrate offered was restricted to limit the effect of concentrate intake on calf metabolism. Individual daily consumption and weekly body weight were measured, and 4 h after the morning feeding, blood samples were obtained at 14 and 35 d to determine general biochemical parameters and plasma AA concentrations. On d 10 of the study, we conducted an intestinal permeability test by including 21 g of lactulose and 4.2 g of d-mannitol as markers in the MR. We found no differences in calf performance or in intestinal permeability (measured as lactulose:mannitol ratio). Serum glucose concentration was greater in unsupplemented calves than in Glu-supplemented calves. At 14 d, the proportion of plasma Leu was greater in Glu-supplemented calves; the proportion of Ile tended to be greater in Glu-supplemented calves; and the proportion of Met tended to be greater in unsupplemented calves. We observed no other differences. Small changes occurred in AA metabolism when supplementing calf MR with 0.3% glutamic acid, without leading to improvements in calf performance or changes in intestinal permeability.info:eu-repo/semantics/publishedVersio

Limited Lifespan of Fragile Regions in Mammalian Evolution

An important question in genome evolution is whether there exist fragile regions (rearrangement hotspots) where chromosomal rearrangements are happening over and over again. Although nearly all recent studies supported the existence of fragile regions in mammalian genomes, the most comprehensive phylogenomic study of mammals (Ma et al. (2006) Genome Research 16, 1557-1565) raised some doubts about their existence. We demonstrate that fragile regions are subject to a "birth and death" process, implying that fragility has limited evolutionary lifespan. This finding implies that fragile regions migrate to different locations in different mammals, explaining why there exist only a few chromosomal breakpoints shared between different lineages. The birth and death of fragile regions phenomenon reinforces the hypothesis that rearrangements are promoted by matching segmental duplications and suggests putative locations of the currently active fragile regions in the human genome

The de novo production of halogenated hydroquinone metabolites by the Andean-Patagonian white-rot fungus Phylloporia boldo

The production of halogenated hydroquinone metabolites such as drosophilin A, drosophilin A methyl ether and chloroneb was investigated in the Andean-Patagonian fungus Phylloporia boldo. These chlorinated compounds were detected in both fruiting bodies and living cultures. Gas chromatography-mass spectrometry (GC-MS) quantification of these molecules was performed in liquid media giving similar values in comparison to previous reports. We observed the concentration of drosophilin A, drosophilin A methyl ether and chloroneb increased in liquid culture supplemented with KCl. Furthermore, chlorinated hydroquinone compounds were not detected using liquid media supplemented with KBr. Instead, brominated aromatic molecules were observed and quantified by gas chromatography-mass spectrometry. We consider these results are relevant for the use of these halogenating microorganisms in biotransformation processes.Fil: Riquelme, C.. Universidad de Concepción; ChileFil: Candia, B.. Universidad de Concepción; ChileFil: Ruiz, D.. Universidad de Concepción; ChileFil: Herrera, M.. Universidad de Concepción; ChileFil: Becerra, J.. Universidad de Concepción; ChileFil: Pérez, C.. Universidad de Concepción; ChileFil: Rajchenberg, Mario. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Provincia del Chubut. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Cabrera Pardo, J.R.. University of Utah; Estados Unidos. Universidad del Bio Bio; Chil