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This paper proposes the application of control by state feedback using the linear quadratic regulator (LQR) optimized by metaheuristics to damp low-frequency electromechanical oscillations in electrical power systems. The current sensitivity model was used to represent the single machine infinite bus (SMIB) system in the time domain. The weighting matrices of the LQR were adjusted using four different algorithms: (i) the genetic algorithm, (ii) the differential evolution algorithm, (iii) the particle swarm optimization algorithm, and (iv) the gray wolf optimization (GWO) algorithm. In the cases considered, disturbances were applied to the electrical power system and, then, performances comparisons associated with each metaheuristic were statistically analyzed, in which the number of iterations, error, and time to achieve convergence of each algorithm were compared. From the results, it was possible to conclude that the algorithms were efficient in adjusting the weighting matrices of the LQR, providing additional damping to the poles of interest of the system. It was also possible to conclude that the GWO algorithm presented the best performance, accrediting it as a powerful tool in the study of small-signal stability for the analyzed case., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 ISA. Published by Elsevier Ltd. All rights reserved.)

Coffea arabica is an allotetraploid of high economic importance. C. arabica transcriptome is a combination of the transcripts of two parental genomes (C. eugenioides and C. canephora) that gave rise to the homeologous genes of the species. Previous studies have reported the transcriptional dynamics of C. arabica. In these reports, the ancestry of homeologous genes was identified and the overall regulation of homeologous differential expression (HDE) was explored. One of these genes is part of the FRIGIDA-like family (FRL), which includes the Arabidopsis thaliana flowering-time regulation protein, FRIGIDA (FRI). As nonfunctional FRI proteins give rise to rapid-cycling summer annual ecotypes instead of vernalization-responsive winter-annuals, allelic variation in FRI can modulate flowering time in A. thaliana. Using bioinformatics, genomic analysis, and the evaluation of gene expression of homeologs, we characterized the FRL gene family in C. arabica. Our findings indicate that C. arabica expresses 10 FRL homeologs, and that, throughout flower and fruit development, these genes are differentially transcribed. Strikingly, in addition to confirming the expression of FRL genes during zygotic embryogenesis, we detected FRL expression during direct somatic embryogenesis, a novel finding regarding the FRL gene family. The HDE profile of FRL genes suggests an intertwined homeologous gene regulation. Furthermore, we observed that FLC gene of C. arabica has an expression profile similar to that of CaFRL genes.

Background: The frequently observed stress of medical students worldwide leads them to have psychic suffering often leading to illness. Minor psychic disorders such as anxiety, depression and burnout, have a higher prevalence in these students than in the rest of random population. Different initiatives were tried to minimize the deleterious effects of the medical course and this article aims at showing the repercussions of a elective course that and was proposed as a possibility to help the students., Methods: A qualitative case study took place in a public Brazilian university as an elective discipline offered to medical students in 2013, offering coping strategies for professional stress. The data was collected through a semi-structured individual questionnaire that was anonymous, and given to students on the last day of the course, with 18 Likert scale questions about personal and behavioural changes observed after taking the course. Objective questions were asked about their perception of stress at the beginning and at the end of the course: the use of the coping strategies taught and the perception of the utility of the content. In addition, one open-ended question was asked about the meaning of the discipline to the students. The quantitative data was analysed with descriptive simple statistics and the qualitative with the support of the WebQDA software. The research project was approved by the ethics committee of the institution., Results: The results showed that the course contributed positively to the students' academic life: 67% reported less symptoms of stress at the end of the course; 76% adopted new coping strategies; and 90% considered that this learning activity was useful for identifying stressors and sharing them with colleagues., Conclusions: The elective course produced benefits to the students, representing theoretical-practical learning and an opportunity for reflection and self-knowledge, which caused psychological, behavioural and lifestyle changes. It is recommended that further studies on this theme should be conducted.

The development of abdominal surgery represents an alternative therapy for the morbidly obese; however, patients undergoing this surgical procedure often experience postoperative pulmonary complications. The use of alveolar recruitment maneuvers and/or perioperative ventilatory strategies is a possible alternative to reduce these complications, focusing on the reduction of postoperative pulmonary complications. In this review, the benefits of perioperative ventilatory strategies and the implementation of alveolar recruitment maneuvers in obese patients undergoing abdominal surgery are described.

The objective of this study was to determine if the maternal serum levels of visfatin in the first trimester of pregnancy are altered in cases that develop preeclampsia (PE) and whether the levels are related to placental perfusion reflected in uterine artery pulsatility index (PI). Serum visfatin and uterine artery PI were measured at 11(+0)-13(+6) weeks in 80 cases that developed PE and 240 unaffected controls. The median visfatin and uterine artery PI multiple of the unaffected median (MoM) in the outcome groups was compared and the significance of the association between visfatin MoM and uterine artery PI MoM, birth weight percentile and gestation at delivery was determined. In the PE group, compared with controls, there was a significantly higher median visfatin MoM (1.35, interquartile range (IQR): 0.69-2.16 vs 1.00, IQR: 0.55-1.96, P=0.027) and uterine artery PI MoM (1.19, IQR: 0.95-1.44 vs 1.03, IQR: 0.83-1.22, P<0.0001). In the PE group, there was no significant association between serum visfatin MoM and uterine artery PI MoM (P=0.589), gestation at delivery (P=0.763) or birth weight percentile (P=0.646). Serum visfatin levels at 11-13 weeks are increased in women who develop PE by a mechanism unrelated to impaired placental perfusion.

Objective: To examine the possible effects of maternal and fetal characteristics on the fetal fraction in maternal plasma cell-free (cf) DNA at 11-13 weeks' gestation and estimate the proportion of pregnancies at high risk of non-invasive prenatal testing (NIPT) failure because the fetal fraction is less than 4%., Methods: In 1949 singleton pregnancies at 11-13 weeks' gestation cf-DNA was extracted from maternal plasma. Chromosome-selective sequencing of non-polymorphic and polymorphic loci, where fetal alleles differ from maternal alleles, was used to determine the proportion of cf-DNA that was of fetal origin. Multivariable regression analysis was used to determine significant predictors of the fetal fraction among maternal and fetal characteristics., Results: The fetal fraction decreased with increased maternal weight, it was lower in women of Afro-Caribbean origin than in Caucasians and increased with fetal crown-rump length, serum pregnancy-associated plasma protein-A, serum free β-human chorionic gonadotropin, smoking and trisomy 21 karyotype. The median fetal fraction was 10.0% (interquartile range, 7.8-13.0%) and this decreased with maternal weight from 11.7% at 60 kg to 3.9% at 160 kg. The estimated proportion with fetal fraction below 4% increased with maternal weight from 0.7% at 60 kg to 7.1% at 100 kg and 51.1% at 160 kg., Conclusions: Fetal fraction in maternal plasma cf-DNA is affected by maternal and fetal characteristics., (Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.)

Background: Visfatin and adiponectin are produced by adipose tissue and have opposite effects on insulin resistance. Circulating concentrations of these biomarkers are altered in type 2 diabetes mellitus. We sought to examine the potential value of maternal serum visfatin and adiponectin concentrations in early pregnancy as potential biomarkers in the prediction of gestational diabetes mellitus (GDM)., Methods: This work was a case-control study of 100 women who developed GDM and 300 nondiabetic controls. Maternal serum visfatin and adiponectin were measured between 11 and 13 weeks of gestation. Regression analysis in the nondiabetic group was performed to examine the maternal characteristics affecting the serum concentrations of visfatin and adiponectin. Likelihood ratios for GDM were calculated for visfatin and adiponectin, and performance of screening was assessed by using ROC curve analysis., Results: In the GDM group compared with the nondiabetic group, the median maternal serum visfatin concentration was increased (1.34 multiples of the median [MoM], interquartile range [IQR] 0.70-2.87, vs 1.00 MoM, IQR: 0.53-1.92; P = 0.004) and serum adiponectin was decreased (0.66 MoM, IQR 0.50-0.92, vs 1.01, IQR 0.70-1.29; P < 0.0001). In screening for GDM by a combination of maternal factors and serum adiponectin and visfatin, the estimated detection rate was 68.0% (95% CI 58.3-76.3%), at a false-positive rate of 10%., Conclusions: At 11-13 weeks in pregnancies that develop GDM, the serum concentration of adiponectin is decreased and visfatin is increased, and these biomarkers can be combined with maternal factors to provide effective early screening for GDM.