The effect of Fernblock® in preventing blue-light-induced oxidative stress and cellular damage in retinal pigment epithelial cells is associated with NRF2 induction.

Blue light exposure of the ocular apparatus is currently rising. This has motivated a growing concern about potential deleterious effects on different eye structures. To address this, ARPE-19 cells were used as a model of the retinal pigment epithelium and subjected to cumulative expositions of blue light. The most relevant cellular events previously associated with blue-light-induced damage were assessed, including alterations in cell morphology, viability, cell proliferation, oxidative stress, inflammation, and the induction of DNA repair cellular mechanisms. Consistent with previous reports, our results provide evidence of cellular alterations resulting from repeated exposure to blue light irradiation. In this context, we explored the potential protective properties of the vegetal extract from Polypodium leucotomos, Fernblock® (FB), using the widely known treatment with lutein as a reference for comparison. The only changes observed as a result of the sole treatment with either FB or lutein were a slight but significant increase in γH2AX+ cells and the raise in the nuclear levels of NRF2. Overall, our findings indicate that the treatment with FB (similarly to lutein) prior to blue light irradiation can alleviate blue-light-induced deleterious effects in RPE cells, specifically preventing the drop in both cell viability and percentage of EdU+ cells, as well as the increase in ROS generation, percentage of γH2AX+ nuclei (more efficiently with FB), and TNF-α secretion (the latter restored only by FB to similar levels to those of the control). On the contrary, the induction in the P21 expression upon blue light irradiation was not prevented neither by FB nor by lutein. Notably, the nuclear translocation of NRF2 induced by blue light was similar to that observed in cells pre-treated with FB, while lutein pre-treatment resulted in nuclear NRF2 levels similar to control cells, suggesting key differences in the mechanism of cellular protection exerted by these compounds. These results may represent the foundation ground for the use of FB as a new ingredient in the development of alternative prophylactic strategies for blue-light-associated diseases, a currently rising medical interest.

Mitochondrial Stress Induces Plant Resistance Through Chromatin Changes.

Plants respond more efficiently when confronted with previous similar stress. In the case of pathogens, this memory of a previous infection confers resistance to future ones, which possesses a high potential for agricultural purposes. Some of the defense elements involved in this resistance phenotype, as well as epigenetic mechanisms participating in the maintenance of the memory, are currently known. However, the intracellular cascade from pathogen perception until the establishment of the epigenetic memory is still unexplored. Here, through the induction of mitochondrial stress by exogenous applications of Antimycin A in Arabidopsis thaliana plants, we discovered and characterized a role of mitochondrial stress in plant-induced resistance. Mitochondrial stress-induced resistance (MS-IR) is effective locally, systemically, within generation and transgenerationally. Mechanistically, MS-IR seems to be mediated by priming of defense gene transcription caused by epigenetic changes. On one hand, we observed an increment in the deposition of H3K4me3 (a positive epigenetic mark) at the promoter region of the primed genes, and, on the other hand, the DNA (de)methylation machinery seems to be required for the transmission of MS-IR to the following generations. Finally, we observed that MS-IR is broad spectrum, restricting the colonization by pathogens from different kingdoms and lifestyles. Altogether, this evidence positions mitochondria as a prominent organelle in environment sensing, acting as an integrating platform to process external and internal signals, triggering the appropriate response, and inducing the epigenetic memory of the stress to better react against future stressful conditions.

Oxylipins From Different Pathways Trigger Mitochondrial Stress Signaling Through Respiratory Complex III.

Plant oxylipins are signaling molecules produced from fatty acids by oxidative pathways, mainly initiated by 9- and 13-lipoxygenases (9-LOX and 13-LOX), alpha-dioxygenases or non-enzymatic oxidation. Oxylipins from the 9-LOX pathway induce oxidative stress and control root development and plant defense. These activities have been associated with mitochondrial processes, but precise cellular targets and pathways remain unknown. In order to study oxylipin signaling, we previously generated a collection of Arabidopsis thaliana mutants that were insensitive to the 9-LOX products 9(S)-hydroxy-10,12, 15-octadecatrienoic acid (9-HOT) and its ketone derivative 9-KOT (noxy mutants). Here, we describe noxy1, noxy3, noxy5, noxy23, and noxy54 mutants, all affected in nucleus-encoded mitochondrial proteins, and use them to study the role of mitochondria in oxylipin signaling. Functional and phenotypic analyses showed that noxy plants displayed mitochondrial aggregation, reduced respiration rates and resistance to the complex III inhibitor Antimycin A (AA), thus indicating a close similarity of the oxylipin signaling and mitochondrial stress. Application of 9-HOT and 9-KOT protected plants against subsequent mitochondrial stress, whereas they boosted root growth reduction when applied in combination with complex III inhibitors but did not with inhibitors of other respiratory complexes. A similar effect was caused by linear-chain oxylipins from 13-LOX or non-enzymatic pathways having α,ß-unsaturated hydroxyl or keto groups in their structure. Studies to investigate 9-HOT and 9-KOT activity indicated that they do not reduce respiration rates, but their action is primarily associated with enhanced ROS responses. This was supported by the results showing that 9-HOT or 9-KOT combined with AA amplified the expression of oxylipin- and ROS-responding genes but not of the AA marker AOX1a, thus implying the activation of a specific mitochondria retrograde signaling pathway. Our results implicate mitochondrial complex III as a hub in the signaling activity of multiple oxylipin pathways and point at downstream ROS responses as components of oxylipin function.

Measuring Online Teaching Service Quality in Higher Education in the COVID-19 Environment.

The use of the Internet to develop new technologies has generated a considerable change in teaching and student learning in higher education. The pandemic caused by COVID-19 has forced universities to switch from face-to-face to online instruction. Furthermore, this transfer process was planned and executed quickly, with urgent redesigns of courses originally conceived for live teaching. The aim of this work is to measure the service quality of online teaching delivered during the COVID-19 period. The methodology was based on an importance-performance analysis using a structural equations model. The data were obtained from a sample of 467 students attending a university in southern Spain. The results reveal five priority attributes of online teaching that need to be improved in order to enhance the service quality of the virtual instruction provided to students. Universities need to redefine their online format by integrating methodological and technological decisions and involving collaboration between teachers, students and administration staff and services. The results do not apply to educational institutions that exclusively teach courses online, but to those institutions that had to rapidly adapt, and shift course material originally designed for face-to-face training.

Costs and Benefits of Transgenerational Induced Resistance in Arabidopsis.

Recent evidence suggests that stressed plants employ epigenetic mechanisms to transmit acquired resistance traits to their progeny. However, the evolutionary and ecological significance of transgenerational induced resistance (t-IR) is poorly understood because a clear understanding of how parents interpret environmental cues in relation to the effectiveness, stability, and anticipated ecological costs of t-IR is lacking. Here, we have used a full factorial design to study the specificity, costs, and transgenerational stability of t-IR following exposure of Arabidopsis thaliana to increasing stress intensities by a biotrophic pathogen, a necrotrophic pathogen, and salinity. We show that t-IR in response to infection by biotrophic or necrotrophic pathogens is effective against pathogens of the same lifestyle. This pathogen-mediated t-IR is associated with ecological costs, since progeny from biotroph-infected parents were more susceptible to both necrotrophic pathogens and salt stress, whereas progeny from necrotroph-infected parents were more susceptible to biotrophic pathogens. Hence, pathogen-mediated t-IR provides benefits when parents and progeny are in matched environments but is associated with costs that become apparent in mismatched environments. By contrast, soil salinity failed to mediate t-IR against salt stress in matched environments but caused non-specific t-IR against both biotrophic and necrotrophic pathogens in mismatched environments. However, the ecological relevance of this non-specific t-IR response remains questionable as its induction was offset by major reproductive costs arising from dramatically reduced seed production and viability. Finally, we show that the costs and transgenerational stability of pathogen-mediated t-IR are proportional to disease pressure experienced by the parents, suggesting that plants use disease severity as an environmental proxy to adjust investment in t-IR.

Long-Term Anorectal Manometry Outcomes After Laparoscopic and Transanal Total Mesorectal Excision.

Background: During transanal total mesorectal excision (TaTME), sustained dilation of the anal canal occurs, which can cause anatomical and functional damage to the sphincter complex. This study aimed to analyze the impact of laparoscopic total mesorectal excision (LaTME) and TaTME in anorectal sphincter function. Materials and Methods: An observational study was conducted comparing two cohorts of patients who underwent LaTME or TaTME for rectal cancer. The two groups were paired for comparison based on age, gender, and distance of the neoplasm to the anal margin. The anorectal function was assessed by manometry before surgery and at least 6 months after primary intervention or stoma closure. The intestinal function was assessed using the low anterior resection syndrome (LARS) score. Results: Twenty-two patients were included. There were no significant differences in baseline characteristics between groups except for the time between surgery and testing. A decrease in the mean resting and squeeze pressures between pre- and postoperative manometry was observed in both the treatment groups, the difference being only significant in the squeeze pressure values (TaTME P = .003; LaTME P = .004). After surgery, squeeze pressure reduction correlated with a worsening of the LARS point count (rho 0.587; P = .004). The time elapsed since surgery was negatively correlated with the LARS point count (rho -0.696; P = .001) and the difference between pre- and postoperative mean squeeze pressures (rho -0.499; P = .018). Conclusion: Manometric findings after TME are comparable between the laparoscopic and the transanal approach. Deterioration of both anal sphincter function and LARS improves with time after surgery.

Surviving in a Hostile World: Plant Strategies to Resist Pests and Diseases.

As primary producers, plants are under constant pressure to defend themselves against potentially deadly pathogens and herbivores. In this review, we describe short- and long-term strategies that enable plants to cope with these stresses. Apart from internal immunological strategies that involve physiological and (epi)genetic modifications at the cellular level, plants also employ external strategies that rely on recruitment of beneficial organisms. We discuss these strategies along a gradient of increasing timescales, ranging from rapid immune responses that are initiated within seconds to (epi)genetic adaptations that occur over multiple plant generations. We cover the latest insights into the mechanistic and evolutionary underpinnings of these strategies and present explanatory models. Finally, we discuss how knowledge from short-lived model species can be translated to economically and ecologically important perennials to exploit adaptive plant strategies and mitigate future impacts of pests and diseases in an increasingly interconnected and changing world.

The role of DNA (de)methylation in immune responsiveness of Arabidopsis.

DNA methylation is antagonistically controlled by DNA methyltransferases and DNA demethylases. The level of DNA methylation controls plant gene expression on a global level. We have examined impacts of global changes in DNA methylation on the Arabidopsis immune system. A range of hypo-methylated mutants displayed enhanced resistance to the biotrophic pathogen Hyaloperonospora arabidopsidis (Hpa), whereas two hyper-methylated mutants were more susceptible to this pathogen. Subsequent characterization of the hypo-methylated nrpe1 mutant, which is impaired in RNA-directed DNA methylation, and the hyper-methylated ros1 mutant, which is affected in DNA demethylation, revealed that their opposite resistance phenotypes are associated with changes in cell wall defence and salicylic acid (SA)-dependent gene expression. Against infection by the necrotrophic pathogen Plectosphaerella cucumerina, nrpe1 showed enhanced susceptibility, which was associated with repressed sensitivity of jasmonic acid (JA)-inducible gene expression. Conversely, ros1 displayed enhanced resistance to necrotrophic pathogens, which was not associated with increased responsiveness of JA-inducible gene expression. Although nrpe1 and ros1 were unaffected in systemic acquired resistance to Hpa, they failed to develop transgenerational acquired resistance against this pathogen. Global transcriptome analysis of nrpe1 and ros1 at multiple time-points after Hpa infection revealed that 49% of the pathogenesis-related transcriptome is influenced by NRPE1- and ROS1-controlled DNA methylation. Of the 166 defence-related genes displaying augmented induction in nrpe1 and repressed induction in ros1, only 25 genes were associated with a nearby transposable element and NRPE1- and/or ROS1-controlled DNA methylation. Accordingly, we propose that the majority of NRPE1- and ROS1-dependent defence genes are regulated in trans by DNA methylation.

Factores asociados al síndrome de burnout en docentes de colegios de la ciudad de Cali, Colombia / Factors associated to Burnout Syndrome in high school teachers in Cali, Colombia

El objetivo de la investigación fue establecer los factores asociados al síndrome de burnout en docentes de dos instituciones educativas formales privada y pública de la ciudad de Cali, Colombia. Se describieron las dimensiones del síndrome (Agotamiento Emocional, Despersonalización y Falta de Realización Personal) y su relación con los factores organizacionales, el Estrés del Rol y las características sociodemográficas de los docentes. Para esto se aplicó el Cuestionario de Burnout en Profesores - Modificado (CBP-M) a una muestra de 82 docentes de un colegio público y uno privado. Los resultados muestran bajos niveles de burnout en ambas instituciones. Respecto a los factores asociados, se halló relación con el Estrés de Rol y los factores organizacionales de Supervisión, Condiciones Organizacionales y Preocupaciones Profesionales. Las variables sociodemográficas no presentaron relaciones significativas con el síndrome, a excepción del nivel de enseñanza en el cual los docentes imparten clases.

The goal of the study was to locate factors related to burnout syndrome in teachers of two formal private and public educational institutions from Cali, Colombia. The syndrome's dimensions (Emotional Exhaustion, Depersonalization and Reduced Sense of Personal Accomplishment) and their relation to organizational factors, the Stress of the Role and socio-demographic characteristics of the teachers were described. The Modified Burnout in Teachers Questionnaire (CBP-M) was applied to a sample of 82 teachers from one public and one private school. Results show a low level of burnout syndrome in both institutions. An association with the levels of stress of role and organizational factors such as supervision, job conditions and professional worries was found. The socio-demographic characteristics did not show significant relations with the syndrome, with the exception of the level of education in which the teachers give classes.

K-space Prony's method for generating the basis functions of multi-Gaussian beam models.

The expansion coefficients of a multi-Gaussian ultrasonic beam model are obtained by a new approach that applies Prony s method in a K-space domain. This method allows the fitting of the Gaussian beam directly at the face of the transducer with very high computational efficiency. It is demonstrated that the K-space Prony's method can be used to accurately model the transducer field of planar and focused piston transducers, as well as probes that do not act as pistons. The choice of parameters appearing in the method and their influence on performance are discussed.

Análisis de los factores de riesgo asociados a infección quirúrgica en un servicio de urología / Analysis of risk factors associated with surgical site infection in a urology department

Introducción: Las infecciones de sitio quirúrgico (ISQ) originan un considerable aumento de la morbilidad y de los costes económicos y sociales. El objetivo de este estudio es el análisis de factores de riesgo asociados a la ISQ en cirugía urológica. Material y método: Es un estudio prospectivo que incluye a 308 pacientes intervenidos de cirugía mayor. Los factores de riesgo que estudiamos son urgencia de la cirugía, preparación del paciente, estancias prequirúrgicas, profilaxis antibiótica, el grado de contaminación de la cirugía, la duración de la intervención y el estado de salud del paciente. Nos interesamos por los estándares de calidad en la incidencia de las ISQ. Resultados: Los factores de riesgo que tienen en cuenta el estado de salud de los pacientes (odds ratio [OR] = 3,16) y la duración de la intervención superior a 90 min (OR = 3,41) son los factores que más se relacionan con las ISQ. La cirugía con riesgo de infección, potencialmente contaminada o sucia se infecta 2,2 veces más. La incidencia de la infección de sitio quirúrgico fue del 2,27% (intervalo de confianza [IC] del 95%, 3,43-1,11) y en cirugía limpia, del 1,72%. Reciben profilaxis antibiótica en el 95,2% de las indicaciones (IC del 95%, 97,8-92,6). Conclusiones: Los factores de riesgo de ISQ que integran el sistema NNIS alcanzan en este estudio mayor significación; abogamos por la utilización de este sistema, por su fácil aplicación, que permitiría unificar criterios entre hospitales y conocer su nivel de calidad asistencial

Introduction: Surgical site infections (SSIs) substantially increase morbidity and economic and social costs. The objective of this study was to analyze the risk factors associated with SSIs in urological surgery. Material and method: We performed a prospective study of 308 surgical patients. The risk factors studied were surgical urgency, patient preparation, preoperative hospital stay, antibiotic prophylaxis, degree of contamination during surgery, duration of the intervention, and patient health status. We were interested in the quality standards used in the incidence of SSIs. Results: The two factors most closely related to SSIs were the risk factors associated with the patient's health status with an (OR) of 3.16 and interventions lasting more than 90 minutes with an (OR) of 3.41. Surgery with an infection risk, potentially contaminated or dirty, showed a 2.2-fold increase in infections. The incidence of SSI was 2.27% (95% CI: 3.43-1.11) and was 1.72 in clean surgery. Among patients with indication for antibiotic prophylaxis, 95.2% received this therapy (95% CI: 97.8-92.6). Conclusions: The most important risk factors for SSIs in the present study were those composing the National Nosocomial Infections Surveillance (NNIS) system. Therefore, we advocate using this system because it is easy to implement, and because it would allow criteria to be standardized among hospitals and the quality of care to be determined

Determination of an ultrasonic transducer's sensitivity and impedance in a pulse-echo setup.

The role that an ultrasonic piezoelectric transducer plays in an ultrasonic measurement system can be described in terms of the transducer's input electrical impedance and its sensitivity. Here, a new model-based approach is proposed to determine both the transducer impedance and sensitivity in a pulse-echo setup. This new method is much simpler to apply than previous "self-reciprocity" calibration methods for determining sensitivity and generalizes those methods. It is demonstrated that sensitivities obtained with this new method agree well with the sensitivities obtained by a three-transducer method commonly used in calibration studies. It is demonstrated that at the megahertz frequencies at which ultrasonic transducers operate it is important to compensate for cabling effects in these measurements. The influence of the pulser/receiver settings on the results obtained also will be discussed.