Virulence of Xanthomonas translucens pv. poae Isolated from Poa annua

Chaves, Arielle,Mitkowski, Nathaniel The Korean Society of Plant Pathology 2013 Plant Pathology Journal Vol.29 No.1

Bacterial wilt is a vascular wilt disease caused by Xanthomonas translucens pv. poae that infects Poa annua, a grass that is commonly found on golf course greens throughout the world. Bacterial wilt causes symptoms of etiolation, wilting, and foliar necrosis. The damage is most prevalent during the summer and the pathogen can kill turf under conditions optimal for disease development. Fifteen isolates of X. translucens pv. poae were collected from northern regions in the United States and tested for virulence against P. annua. All 15 isolates were pathogenic on P. annua, but demonstrated variable levels of virulence when inoculated onto P. annua under greenhouse conditions. The isolates were divided into two virulence groups. The first group containing four isolates generally resulted in less than 40% mortality following inoculation. The second group, containing the other eleven isolates, produced between 90 and 100% mortality following inoculation. These results suggest that differences in the virulence of bacterial populations present on a golf course may result in more or less severe amounts of observed disease.

Neuromuscular blockade management in patients with COVID-19

Chaves-Cardona Harold,Hernandez-Torres Vivian,Kiley Sean,Renew Johnathan 대한마취통증의학회 2021 Korean Journal of Anesthesiology Vol.74 No.4

This narrative review evaluates the evidence for using neuromuscular blocking agents (NMBA) in patients being treated for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While large prospective randomized-controlled trials (RCTs) are lacking at this point in time, smaller observational studies and case series are reviewed to ascertain the indications and utility of NMBAs. Additionally, large RCTs that address similar clinical scenarios are reviewed and the authors translate these findings to patients with COVID-19. Specifically, NMBAs can be helpful during endotracheal intubation to minimize the risk of patient coughing and possibly infecting healthcare personnel. NMBAs can also be used in patients to promote patient-ventilator synchrony while reducing the driving pressure needed with mechanical ventilation (MV), particularly in patients with the severe clinical presentation (Type H phenotype). Prone positioning has also become a cornerstone in managing refractory hypoxemia in patients with SARS-CoV-2 acute respiratory distress syndrome (ARDS), and NMBAs can be useful in facilitating this maneuver. In the perioperative setting, deep levels of neuromuscular blockade can improve patient outcomes during laparoscopic operations and may theoretically reduce the risk of aerosolization as lower insufflation pressures may be utilized. Regardless of the indication, quantitative neuromuscular monitoring remains the only reliable method to confirm adequate recovery following cessation of neuromuscular blockade. Such monitors may serve a unique purpose in patients with COVID-19 as automation of measurements can reduce healthcare personnel-patient contact that would occur during periodic subjective evaluation with a peripheral nerve stimulator.

Effects on Performance of Sulla and/or Maize Silages Supplements for Grazing Dairy Cows

Chaves, Alexandre V.,Woodward, S.L.,Waghorn, G.C.,Brookes, I.M.,Burke, J.L. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.9

The objective of this study was to investigate the effects of either maize or sulla silage supplementation to grazing dairy cows in summer. Forage mixtures used in the four week trial were based on previous experimental results but inclusion of rumen fistulated cows in five treatments enabled rumen sampling and use of in sacco incubations to determine the diet effects on digestion kinetics. Sulla and maize silages were used to supplement pasture and to meet minimum requirements for dietary protein concentration. Five groups of ten cows were grazed on a restricted daily allowance of 18 kg dry matter (DM) pasture/cow to simulate a summer pasture deficit, and four of these five groups received an additional 6 kg DM $cow^{-1}d^{-1}$ of silage (sulla, maize, or sulla and maize silages). A sixth group was given a relatively unrestricted (38 kg DM $cow^{-1}d^{-1}$) pasture allowance. The silage mixtures and pasture were incubated in sacco during the final week of the trial. The pasture was of high nutritive value and not typical of usual summer conditions, which favoured a response to quantity rather than quality of silage supplements. There was no difference in cow performance with the four silage supplements and the low milk solids (MS) production (about 1.0 kg $MS\;d^{-1}$) relative to full pasture (1.3 kg $MS\;d^{-1}$) showed the principal limitation to performance was dry matter intake. Milk composition was not affected by silage type and the low level of pasture substitution (0.29) suggested metabolizable energy (ME) was the principal limitation to performance. Samples of rumen liquor and in sacco data demonstrated significant effects of supplement; DM degradation rates (k) was highest ($0.084h^{-1}$) when cows were fed 6 kg sulla silage whereas diets with a high proportion of maize silage were slowly degraded (p<0.01).

Virulence of Xanthomonas translucens pv. poae Isolated from Poa annua

Arielle Chaves,Nathaniel Mitkowski 한국식물병리학회 2013 Plant Pathology Journal Vol.29 No.1

Bacterial wilt is a vascular wilt disease caused by Xanthomonas translucens pv. poae that infects Poa annua, a grass that is commonly found on golf course greens throughout the world. Bacterial wilt causes symptoms of etiolation, wilting, and foliar necrosis. The damage is most prevalent during the summer and the pathogen can kill turf under conditions optimal for disease development. Fifteen isolates of X. translucens pv. poae were collected from northern regions in the United States and tested for virulence against P. annua. All 15 isolates were pathogenic on P. annua, but demonstrated variable levels of virulence when inoculated onto P. annua under greenhouse conditions. The isolates were divided into two virulence groups. The first group containing four isolates generally resulted in less than 40% mortality following inoculation. The second group, containing the other eleven isolates, produced between 90 and 100%mortality following inoculation. These results suggest that differences in the virulence of bacterial populations present on a golf course may result in more or less severe amounts of observed disease.

Fisheries resources management in Perú

Grecia Albania Chaves Collazos 한국수산과학회 양식분과 2022 한국수산과학회 양식분과 학술대회 Vol.2022 No.5

Ortografia: um desafio na escolarização brasileira

Idalena Oliveira Chaves 한국 포르투갈-브라질 학회 2014 포르투갈-브라질 연구 Vol.11 No.3

In recent decades, Brazil has undergone major changes in basic education with teacher training and distribution of instructional materials programs. The results begin to appear in the public school development index in the country. Nevertheless, one aspect of learning continues excelled in research on the learning of the mother tongue: the inability to write according to the spelling rules. Over time, mastering spelling has become less common. Most of the students, particularly from public schools, have completed primary education without assimilating the spelling system. This paper analyzes spelling errors committed by students of the 1st year of high school, that should have been corrected in earlier grades, but that persist despite many years of schooling.

Effect of endodontic sealer on postoperative pain: a network meta-analysis

Monteiro Cynthia Maria Chaves,Martins Ana Cristina Rodrigues,Reis Alessandra,de Geus Juliana Larocca 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.1

This systematic review and network meta-analysis aimed to answer the following focused research question: “Does the type of endodontic sealer affect the postoperative pain in patients who received endodontic treatment?” Different databases and grey literature were surveyed. Only one randomized controlled trial were included. The risk of bias in the studies was evaluated by using the Cochrane Collaboration’s tool. A random-effects meta-analysis was conducted to compare the risk and intensity of postoperative pain. The quality of the body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Out of 11,601 studies, 15 remained for qualitative analyses and 12 for meta-analysis. Seven studies were classified at high risk of bias, and 8 studies raised some concerns. No significant differences between the endodontic materials were observed in the direct comparisons, both in risk and in intensity of postoperative pain (pairwise comparisons with 2 studies: I2 = 0%; p > 0.05 and 8 studies: I2 = 23%; p > 0.05, respectively). The certainty of the evidence was graded as low or moderate. There was no difference in the risk and intensity of postoperative pain after filling with different endodontic sealers. Further systematic reviews should be conducted.

Unknown Input Observer-based Actuator and Sensor Fault Estimation Technique for Uncertain Discrete Time Takagi-Sugeno Systems

Emanoel R. Q. Chaves Jr.,André F. O. de A. Dantas,André L. Maitelli 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.7

This paper presents an Unknown Input robust Observer (UIO) capable of simultaneously estimate both sensor fault and system states. The system is assumed to be discrete-time Takagi-Sugeno (T-S) Fuzzy with uncertainties. An augmented system is obtained from the dynamic fault model and original system. Afterward, a UIO is designed for the augmented system aiming at decoupling process disturbances. Its design is obtained by using an H∞ optimization technique and developed to maintain the observer stable, reducing the non-decoupled process disturbances effect. The proposed method is validated by two numerical examples as it is compared to a regular UIO technique and the extended Kalman filter. Results show the proposed technique presents better performance when the dynamic system is not purely nonlinear even if the same tuning parameters are chosen. Although other techniques are not able to ensure the error limitation, the proposed one is capable of it even in nonlinear systems.

Tucumã (Astrocaryum aculeatum) Prevents Oxidative and DNA Damage to Retinal Pigment Epithelium Cells

Beatriz da Silva Rosa Bonadiman,Cláudia Chaves,Charles Elias Assmann,Grazielle Castagna Cezimbra Weis,Audrei de Oliveira Alves,Amanda Leitão Gindri,Cláudio Chaves,Ivana Beatrice Mânica da Cruz,Ariane 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.10

Eye diseases have a negative impact on the eyesight quality of the world population. The age-related macular degeneration (AMD) draws special attention since it is a chronic disorder characterized by oxidative and inflammatory damage to the retinal epithelial pigment, which triggers progressive vision loss. In the Brazilian Amazon, Astrocaryum aculeatum is an Amazonian fruit (Tucumã) used by riverside communities in traditional medicine to treat a number of ailments. These communities have recently shown to have increased longevity and reduced prevalence of age-related morbidity. Thus, the aim of this research was to chemically characterize and analyze the in vitro antioxidant effect and molecular damage prevention of the Tucumã ethanolic extract in retinal pigment epithelium (RPE) cells in a model for AMD. The extract was chemically characterized by ultra-high-performance liquid chromatography (HPLC) coupled with diode-array detection and mass spectrophotometry (HPLC-DAD-MS). In vitro protocols were performed, and the cytopreventive effect of Tucumã on RPE cells exposed to high concentrations of superoxide anion, an oxidant and genotoxic molecule, as well as the effect of Tucumã extract on oxidative and molecular makers were assessed. Biochemical and flow cytometry analyses were conducted in these protocols. The extract presents high concentrations of caffeic acid, gallic acid, catechin, luteolin, quercetin, and rutin. Treatment did not show cytotoxic effects in cells treated only with extract at 50 μg/mL. In fact, it improved cell viability and was able to prevent necrosis and apoptosis, and oxidative and molecular damage was significantly reduced. In summary, Tucumã is an important Amazon fruit, which seems to contribute significantly to improve human health conditions, as our findings suggest that its extract has a relevant chemical matrix rich in antioxidant molecules, and its consumption could improve eye health and contribute to prevention against oxidative stress through cytoprevention, reactive oxygen species reduction, and maintenance of DNA integrity in retinal pigment epithelium (RPE) cells.

Opportunistic sampling-based active visual SLAM for underwater inspection

Springer Science + Business Media 2016 AUTONOMOUS ROBOTS Vol.40 No.7

<P>This paper reports on an active SLAM framework for performing large-scale inspections with an underwater robot. We propose a path planning algorithm integrated with visual SLAM that plans loop-closure paths in order to decrease navigation uncertainty. While loop-closing revisit actions bound the robot's uncertainty, they also lead to redundant area coverage and increased path length. Our proposed opportunistic framework leverages sampling-based techniques and information filtering to plan revisit paths that are coverage efficient. We employ Gaussian process regression for modeling the prediction of camera registrations and use a two-step optimization procedure for selecting revisit actions. We show that the proposed method offers many benefits over existing solutions and good performance for bounding navigation uncertainty in long-term autonomous operations with hybrid simulation experiments and real-world field trials performed by an underwater inspection robot.</P>