Determination of Uncertainty in Measuring Instruments in Electrical Engineering Programs

Cuando los alumnos de Ingeniería Eléctrica inician el curso de Instrumentación y medidas, han visto previamente los cursos de Cálculo, Física, Probabilidad y Estadística; sin embargo, tienen problemas para aplicar los conocimientos adquiridos en la solución de problemas relacionados con mediciones, no solo eléctricas sino de las variables que tienen que ver con el ejercicio de la profesión como lo son: caudales de agua, radiación solar, velocidad del viento y niveles de agua. El artículo muestra cómo integrar todos los conceptos mencionados en el proceso de determinación de la incertidumbre en medidas, con el fin de mejorar la forma como se describen los resultados de los procesos de medición y/o determinación de errores. Con este propósito, se muestra el proceso metodológico descrito mediante un ejemplo para determinar el valor de una resistencia, teniendo en cuenta los datos de las medidas de voltaje y corriente, utilizando pocos datos. El objetivo es conocer la incertidumbre Tipo A, Tipo B y los factores que afectan los procesos de medida debida a: incertidumbre por variaciones aleatorias de las señales medidas, incertidumbre por defectos de los instrumentos, incertidumbre por imprecisión de los instrumentos e incertidumbre por resolución de los mismos. Durante el cálculo de la incertidumbre, el estudiante usa el conocimiento probabilístico adquirido después de determinar el valor de la incertidumbre U, a partir de la incertidumbre combinada u (R), donde se tiene en cuenta el factor de cobertura. Esto permite aprender la importancia de expresar los resultados con valores superiores (+) o inferiores (-) de incertidumbre. Para el caso del ejercicio desarrollado: R = 733,31 +/- 8,10 ohm.When electrical engineering students start their instrumentation and measurement course, they have previously taken calculus, physics, probability, and statistics. However, they have problems to apply the knowledge they acquired to solve problems related to electrical measurements and variables in the profession, such as water flows, solar radiation, wind speed and water levels. This paper shows how to integrate all the concepts involved in the process to calculate measurement uncertainty in order to improve the way the results of measurements and/or error determination processes are described. For that purpose, this study presents an applied exercise and a methodological process by means of an example, where the value of a resistance is determined taking into account the data of voltage and current measurements and using few data. The objective is to focus the process on estimating Type A and Type B uncertainty and the factors that affect the measurement processes, such as uncertainty due to random variations of the measured signals, instrument defects, imprecision of the instruments, or their resolution. During the calculation of uncertainty proposed here, students use the probabilistic knowledge they have acquired after they determined the value of the uncertainty U from the combined uncertainty u (R), where the coverage factor is taken into account. This allows us to learn about the importance of expressing the results with higher (+) or lower (-) values of uncertainty. In the exercise carried out in this work, R = 733.31 +/- 8.10 ohm

Sociocultural Factors That Influence Migrant Students’ Academic Performance in an English Language Teaching Program: Voices from Abroad

This qualitative research explains how sociocultural factors influence the academic performance of a group of migrant students enrolled in the English Language Teaching Program at Universidad Católica Luis Amigó. Three data collection techniques were implemented for the development of this project. First, a semi-structured interview with open-ended questions was conducted for each participant. Interviews were recorded and then transcribed for analysis purposes. Before the interview, participants were delivered a consent form and a biodata format to be filled. Second, six participants were invited to write a week-long narrative describing their experiences in the target cultural scenario. Third, a focus group was set up with five students selected at random out of the thirteen participants. Major results indicate that students who perceive a higher level of family support are more likely to achieve their academic goals. Besides, migrant students who report fewer difficulties to adjust to the host culture, have greater opportunities to succeed academically. In addition, migrant students’ previous academic experiences have an important impact on their adjustment process to the university context. This study concluded that migrant students’ academic performance is a dialogical and reciprocal relationship among different sociocultural factors

Quality improvement activities associated with organisational capacity in general practice

Copyright © 2007 Australian College of General Practitioners Copyright to Australian Family Physician. Reproduced with permission. Permission to reproduce must be sought from the publisher, The Royal Australian College of General Practitioners.BACKGROUND Clinical audit is recognised worldwide as a useful tool for quality improvement. METHODS A feedback report profiling capacity for chronic disease care was sent to 97 general practices. These practices were invited to complete a clinical audit activity based on that feedback. Data were analysed quantitatively and case studies were developed based on the free text responses. RESULTS Eighty-two (33%) of 247 general practitioners participated in the clinical audit process, representing 57 (59%) of 97 general practices. From the data in their feedback report, 37 (65%) of the 57 practices recognised the area most in need of improvement. This was most likely where the need related to clinical practice or teamwork, and least likely where the need related to linkages with other services, and business and finance. Only 25 practices (46%) developed an action plan related to their recognised area for improvement, and 22 (39%) practices implemented their chosen activity. Participating GPs judged that change activity focused on teamwork was most successful. DISCUSSION The clinical audit process offered participating GPs and practices an opportunity to reflect on their performance across a number of key areas and to implement change to enhance the practice’s capacity for quality chronic disease care. The relationship between need and action was weak, suggesting a need for greater support to overcome barriers.Cheryl Amoroso, Judy Proudfoot, Tanya Bubner, Edward Swan, Paola Espinel, Christopher Barton, Justin Beilby and Mark Harri

Statistical analyses of correlation between fluconazole MICs for Candida spp. assessed by standard methods set forth by the European Committee on Antimicrobial Susceptibility Testing (E.Dis. 7.1) and CLSI (M27-A2).

The European Committee on Antimicrobial Susceptibility Testing (EUCAST) Subcommittee on Antifungal Susceptibility Testing recently published a standard for determining the susceptibility of fermentative yeasts to antifungals. From the beginning, the EUCAST and its North American counterpart, the CLSI, decided to work together in order to establish common standards. As part of this exercise, the susceptibility of a set of 475 yeast isolates was tested by both standards. The intraclass correlation coefficient and the equations defining the linear regression between both methods were estimated. Both methods produced very similar results, with an intraclass correlation coefficient of 0.954 (0.945 to 0.962), although linear regression analysis shows that the EUCAST standard resulted in slightly lower MICs. There were only eight isolates showing at least four twofold dilution MIC differences between both standards. After 24 h of incubation, the MICs obtained by the CLSI method were equivalent to those obtained by the EUCAST standard. In summary, both methods produce very similar MICs, indicating that methodology does not pose any obstacle to obtaining uniform standards for antifungal susceptibility testing of yeast

Intraoperative Liver Surface Completion with Graph Convolutional VAE

In this work we propose a method based on geometric deep learning to predict the complete surface of the liver, given a partial point cloud of the organ obtained during the surgical laparoscopic procedure. We introduce a new data augmentation technique that randomly perturbs shapes in their frequency domain to compensate the limited size of our dataset. The core of our method is a variational autoencoder (VAE) that is trained to learn a latent space for complete shapes of the liver. At inference time, the generative part of the model is embedded in an optimisation procedure where the latent representation is iteratively updated to generate a model that matches the intraoperative partial point cloud. The effect of this optimisation is a progressive non-rigid deformation of the initially generated shape. Our method is qualitatively evaluated on real data and quantitatively evaluated on synthetic data. We compared with a state-of-the-art rigid registration algorithm, that our method outperformed in visible areas

Relationship between Serum Concentration of Uric Acid and Insulin Secretion among Adults with Type 2 Diabetes Mellitus

To determine the relationship between serum concentrations of uric acid and insulin secretion with hyperglycaemic clamp technique among adults with type 2 diabetes mellitus (DM2) without hyperuricemia, we carried out a cross-sectional study on 45 patients of both gender. We observed correlation between uric acid with male gender r = 0.710 (P = 0.001). Also correlation between uric acid and total insulin secretion was positive r = 0.295 (P = 0.049). As well as a positive correlation adjusted for body mass index was demonstrated for the first, second, and total phases of insulin secretion, respectively, r = 0.438 (P = 0.022), r = 0.433 (P = 0.022), and r = 0.439 (P = 0.024). Serum concentration of uric acid showed a positive relationship with the total phase of insulin secretion; even in states prior to hyperuricemia, uric acid can play an important role in the function of the beta cell in patients with DM2

Antifungal susceptibility of invasive yeast isolates in Italy: the GISIA3 study in critically ill patients

<p>Abstract</p> <p>Background</p> <p>Yeasts are a common cause of invasive fungal infections in critically ill patients. Antifungal susceptibility testing results of clinically significant fungal strains are of interest to physicians, enabling them to adopt appropriate strategies for empiric and prophylactic therapies. We investigated the antifungal susceptibility of yeasts isolated over a 2-year period from hospitalised patients with invasive yeast infections.</p> <p>Methods</p> <p>638 yeasts were isolated from the blood, central venous catheters and sterile fluids of 578 patients on general and surgical intensive care units and surgical wards. Etest strips and Sensititre panels were used to test the susceptibility of the isolates to amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole, posaconazole and voriconazole in 13 laboratories centres (LC) and two co-ordinating centres (CC). The Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution method was used at the CCs for comparison.</p> <p>Results</p> <p>Etest and Sensititre (LC/CC) MIC₉₀values were, respectively: amphotericin B 0.5/0.38, 1/1 mg/L; anidulafungin 2/1.5 and 1/1 mg/L; caspofungin 1/0.75 and 0.5/0.5 mg/L; fluconazole 12/8 and 16/16 mg/L; itraconazole 1/1.5, 0.5/0.5 mg/L; posaconazole 0.5 mg/L and voriconazole 0.25 mg/L for all. The overall MIC₉₀values were influenced by the reduced susceptibility of <it>Candida parapsilosis </it>isolates to echinocandins and a reduced or lack of susceptibility of <it>Candida glabrata </it>and <it>Candida krusei </it>to azoles, in particular fluconazole and itraconazole. Comparison of the LC and CC results showed good Essential Agreement (90.3% for Etest and 92.9% for Sensititre), and even higher Categorical Agreement (93.9% for Etest and 96% for Sensititre); differences were observed according to the species, method, and antifungal drug. No cross-resistance between echinocandins and triazoles was detected.</p> <p>Conclusions</p> <p>Our data confirm the different antifungal susceptibility patterns among species, and highlight the need to perform antifungal susceptibility testing of clinically relevant yeasts. With the exception of a few species (e.g. <it>C. glabrata </it>for azoles and <it>C. parapsilosis </it>for echinocandins), the findings of our study suggest that two of the most widely used commercial methods (Etest and Sensititre) provide valid and reproducible results.</p

Multicenter Study of Method-Dependent Epidemiological Cutoff Values for Detection of Resistance in Candida spp. and Aspergillus spp. to Amphotericin B and Echinocandins for the Etest Agar Diffusion Method

BSTRACT Method-dependent Etest epidemiological cutoff values (ECVs) are not available for susceptibility testing of either Candida or Aspergillus species with amphotericin B or echinocandins. In addition, reference caspofungin MICs for Candida spp. are unreliable. Candida and Aspergillus species wild-type (WT) Etest MIC distributions (microorganisms in a species-drug combination with no detectable phenotypic resistance) were established for 4,341 Candida albicans, 113 C. dubliniensis, 1,683 C. glabrata species complex (SC), 709 C. krusei, 767 C. parapsilosis SC, 796 C. tropicalis, 1,637 Aspergillus fumigatus SC, 238 A. flavus SC, 321 A. niger SC, and 247 A. terreus SC isolates. Etest MICs from 15 laboratories (in Argentina, Europe, Mexico, South Africa, and the United States) were pooled to establish Etest ECVs. Anidulafungin, caspofungin, micafungin, and amphotericin B ECVs (in micrograms per milliliter) encompassing �97.5% of the statistically modeled population were 0.016, 0.5, 0.03, and 1 for C. albicans; 0.03, 1, 0.03, and 2 for C. glabrata SC; 0.06, 1, 0.25, and 4 for C. krusei; 8, 4, 2, and 2 forC. parapsilosis SC; and 0.03, 1, 0.12, and 2 for C. tropicalis. The amphotericin B ECV was 0.25 � g/ml for C. dubliniensis and 2, 8, 2, and 16 � g/ml for the complexes of A. fumigatus, A. flavus, A. niger, and A. terreus, respectively. While anidulafung in Etest ECVs classified 92% of the Candida fks mutants evaluated as non-WT, the performance was lower for caspofungin (75%) and micafungin (84%) cutoffs. Finally, although anidulafungin (as an echinocandin surrogate susceptibility marker) and amphotericin B ECVs should identify Candida and Aspergillus isolates with reduced susceptibility to these agents using the Etest, these ECVs will not categorize a fungal isolate as susceptible or resistant, as breakpoints do. KEYWORDS ECVs, Etest ECVs, Etest MICs Candida, Etest MICs Aspergillus, WT isolates, amphotericin B resistance, antifungal resistance, echinocandin resistance, non-WT, susceptibility marke

Novel strategies to fight Candida species infection

In recent years, there has been a significant increase in the incidence of human fungal infections. The increase in cases of infection caused by Candida species, and the consequent excessive use of antimicrobials, has favored the emergence of resistance to conventional antifungal agents over the past decades. Consequently, Candida infections morbidity and mortality are also increasing. Therefore, new approaches are needed to improve the outcome of patients suffering from Candida infections, because it seems unlikely that the established standard treatments will drastically lower the morbidity of mucocutaneous Candida infections and the high mortality associated with invasive candidiasis. This review aims to present the last advances in the traditional antifungal therapy, and present an overview of novel strategies that are being explored for the treatment of Candida infections, with a special focus on combined antifungal agents, antifungal therapies with alternative compounds (plant extracts and essential oils), adjuvant immunotherapy, photodynamic therapy and laser therapy.Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB’’, Ref. FCOMP-01-0124-FEDER-027462BioHealth – Biotechnology and Bioengineering approaches to improve health quality’’, Ref. NORTE-07-0124-FEDER-000027 co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER