449 research outputs found
A Hybrid Sensorless Observer for the Robust Global Asymptotic Flux Reconstruction of Permanent Magnet Synchronous Machines
We propose a hybrid sensorless observer for permanent magnet synchronous machines with global asymptotic stability guarantees. Exploiting the constraint of the rotor flux on a circle of unknown radius, we design an integrator system with periodic jumps triggered by a clock to generate a linear regression containing the flux estimation error. Then, a normalized projected gradient descent identifier provides the observer estimates. For the closed-loop system, it is shown that there exists a robustly globally asymptotically stable compact attractor, which, additionally, ensures zero estimation error if appropriate Persistency of Excitation (PE) conditions are satisfied. In this respect, sufficient conditions ensuring PE are provided for the angular speed and the clock period
Harmonically mode-locked Ti:Er:LiNbO3 waveguide laser
Active mode locking of an Er-diffusion-doped Ti:LiNbO3 waveguide laser by intracavity phase modulation to as
high as the fourth harmonic (5.12 GHz) of the axial-mode frequency spacing is reported. The diode-pumped,
pigtailed, and fully packaged laser with a monolithically integrated intracavity phase modulator has a threshold
of 9 mW (incident pump power Ep jj c) and emits transform-limited pulses of >3.8-ps width and <5.6-pJ pulse
energy (gain-switched mode locking) at 1602-nm wavelength (Es jj c). The relative change of the mode-locking
frequency with the temperature is 3.65 3 1025y±C. The mode-locking acceptance bandwidth is 675 kHz near the
axial-mode frequency spacing at approximately five times the threshold pump power
Monolithically integrated DBR waveguidelaser and intensity modulator in erbiumdoped LiNbO3
For the first time, a DBR laser has been integrated with a Mach
Zehnder intensity modulator in Er diffusion doped, Z cut
LiNbO,, with Ti indiffused waveguides and dry etched Bragg
gratings. The monolithically integrated device has a threshold of
54.8mW incident pump power (hp = 1480nm) and emits, in a
single longitudinal mode, up to 0.65 mW CW output power at hs
= 1561nm. The Mach-Zehnder type intensity modulator has an
optical bandwidth > 3GHz
Inclusión de Physalaemus riograndensis Milstead, 1960 en la batracofauna de Misiones, Argentina, y otros aportes para el conocimiento de su distribución (Amphibia: anura: leptodactylidae)
Physalaemus riograndensis Milstead, 1960. Rep. ARGENTINA, PROV.DE MISIONES, Dpto. Candelaria, Campo San Juan, 27° 25' S, 55° 40' W. 1 ejemplar. MACN número 34.646. Colector: E. Krauczuck.Asociación Herpetológica Argentin
Comparison of a possession score and a poverty index in predicting anaemia and undernutrition in pre-school children and women of reproductive age in rural and urban Côte d'Ivoire
Abstract Objective To determine whether a possession score or a poverty index best predicts undernutrition and anaemia in women of reproductive age (15-49 years; WRA) and children aged 6-59 months living in Côte d'Ivoire. Design Anthropometric measurements were converted to Z-scores to assess stunting, wasting and underweight in children, and converted to BMI in WRA. A venous blood sample was drawn, and Hb concentration and Plasmodium spp. infection were determined. A possession score was generated with categories of zero to four possessions. A five-point (quintile) poverty index using household assets was created using principal component analysis. These socio-economic measures were compared for their ability to predict anaemia and malnutrition. Setting Data were from a nationally representative survey conducted in Côte d'Ivoire in 2007. Subjects A sample of 768 WRA and 717 children aged 6-59 months was analysed. Results Overall, 74·9 % of children and 50·2 % of WRA were anaemic; 39·5 % of the children were stunted, 28·1 % underweight and 12·8 % wasted, while 7·4 % of WRA had BMI < 18·5 kg/m2. In general, there were more stunted and underweight children and thin WRA in rural areas. The poverty index showed a stronger relationship with nutritional status than the possession score; mean Hb difference between the poorest and wealthiest quintiles in children and WRA was 8·2 g/l and 6·5 g/l, respectively (13·9 % and 19·8 % difference in anaemia, respectively; P < 0·001), and Z-scores and BMI were significantly better in the wealthiest quintile (P < 0·001). Conclusions The poverty index was generally a better predictor of undernutrition in WRA and pre-school children than the possession scor
Ferramentas computacionais de apoio às boas práticas de manejo de tilápia.
A piscicultura brasileira cresce cerca de 30% ao ano, por tratar-se de fonte de proteína de alta qualidade e pela lucratividade. De origem africana, a tilapicultura está presente hoje em grande parte do território nacional, mas ainda sofrendo as pressões para a maior qualidade do produto e adoção de práticas menos impactantes ao ambiente. Entre alguns desses impactos citam-se as poluição e interferências em níveis de biodiversidade e de qualidade da água. Assim, o produtor carece de informação e ferramentas que favoreçam a rápida transferência de práticas já identificadas pela pesquisa, que aumentem seu conhecimento e agilidade na incorporação destas às atividades da propriedade. O projeto "Manejo e Gestão Ambiental da Aqüicultura" da Embrapa Meio Ambiente, componente do projeto em rede Aquabrasil, vem identificando Boas Práticas de Manejo (BPM) de tilápia passíveis de uso imediato pelo produtor a partir de sua rápida observação da propriedade. Nele, o sistema informatizado Aquisys está em desenvolvimento para vialibizar o acesso dinâmico, via web, às avaliações e indicadores de produção, manejo e qualidade de água em atenção às BPM. Este trabalho apresenta duas de suas ferramentas computacionais desenvolvidas para tilápia: a) um sistema especialista de rápida avaliação de BPM na propriedade (em linguagem CLIPS); e b) um programa para determinar a %ração e %proteína bruta a ser oferecida, considerando os pesos dos peixes e temperatura local (em linguagens PHP e HTML)
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Preoperative Sinonasal Symptom Scores Predict Post-Surgery, Post-Aspirin Desensitization Disease Status in Aspirin Exacerbated Respiratory Disease
Phenolic profile and biological activity of table grapes (Vitis vinifera L.)
Table grapes are largely produced and consumed in the Mediterranean area. Furthermore, in the last years, the commercial interest in table grapes and other non-alcoholic grape products has notably increased worldwide. In addition to the nutritional aspects, polyphenol compounds in fresh grapes could exert positive effects on human health. The aim of this study was the characterization of the phenolic pattern of sixteen grape varieties and the evaluation of the associated antioxidant capacity and anti-inflammatory activity at gastric level. The methods used were: 1) Folin-Cocalteau\u2019s assay for the quantification of total polyphenol content; 2) High-Performance Liquid Chromatography (HPLC) coupled with Diode-Array Detector (DAD) to perform the quantitative analysis of grapes phenolic fraction 3) DPPH (1,1,-diphenil-2-picrylhydrazyl) spectrophotometric assay for the assessment of radical scavenging activity; 4) assessment of IL-8 release from human gastric epithelial cells to evaluate the anti-inflammatory activity of grape extracts. Some grapes, including seedless varieties, showed that the phenolic pattern was highly correlated with the biological activities, and, in particular, with peel and seeds portion. These results suggest that selected grape varieties could represent, also for consumers who do not drink wine, a source of healthy compounds potentially able to counteract oxidative stress and gastric inflammation
The use of chest ultrasonography in suspected cases of COVID-19 in the emergency department
Aim: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus-specific reverse transcriptase-polymerase chain reaction (RT-PCR) represents the diagnostic gold standard. We explored the value of chest ultrasonography to predict positivity to SARS-CoV-2 on RT-PCR in suspected COVID-19 cases. Patients & methods: Consecutive patients with suspect COVID-19 were included if they had fever and/or history of cough and/or dyspnea. Lung ultrasound score (LUSS) was computed according to published methods. Results: A total of 76 patients were included. A 3-variable model based on aspartate transaminase (AST) > upper limit of normal, LUSS >12 and body temperature >37.5°C yielded an overall accuracy of 91%. Conclusion: A simple LUSS-based model may represent a powerful tool for initial assessment in suspected cases of COVID-19. The gold standard for diagnosis of COVID-19 is RT-PCR. During a pandemic emergency, it may be useful to identify suspect symptomatic patients who may safely be observed without undergoing testing for COVID-19. In this work, a simple model based on the findings of lung ultrasound, AST levels and fever showed an overall accuracy of 91% to predict the results of RT-PCR
Elevated alanine aminotransferase in blood donors: role of different factors and multiple viral infections.
Many different aetiological agents stimulate alanine aminotransferase (ALT) production. Viral markers and other aetiologies were investigated in 2166 individuals, randomly selected from 10 000 consecutive blood donors. Elevation of ALT was found in 10.8% of subjects. Grouping donors according to ALT level and correlating with, respectively, hepatitis B core antibody (HBcAb), cytomegalovirus antibody alone, or associated with HBcAb, showed similar findings (high ALT 11.1%, normal 11.6%; high 85.4%, normal 81.4%; high 10.2%, normal 11.0%, respectively). Hepatitis C virus (HCV) antibody was found to be significantly associated with elevated ALT levels (high 1.7%, normal 0.26%). Other causes of ALT elevation were alcohol abuse (17%), obesity (25%) and dyslipidaemia (38%), but in 11% there was no obvious aetiology. Although HCV is a rare cause of elevated ALT in blood donors, it seems to be the only virus, among those tested, to account for liver damage. This may be due to the non-protective role of HCV antibody, the low specificity of ALT, or the pathogenic role of uninvestigated viruses
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