989 research outputs found

    Constructed response or multiple-choice questions for assessing declarative programming knowledge? That is the question!

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    Aim/Purpose This paper presents a data mining approach for analyzing responses to advanced declarative programming questions. The goal of this research is to find a model that can explain the results obtained by students when they perform exams with Constructed Response questions and with equivalent Multiple-Choice Questions. Background The assessment of acquired knowledge is a fundamental role in the teachinglearning process. It helps to identify the factors that can contribute to the teacher in the developing of pedagogical methods and evaluation tools and it also contributes to the self-regulation process of learning. However, better format of questions to assess declarative programming knowledge is still a subject of ongoing debate. While some research advocates the use of constructed responses, others emphasize the potential of multiple-choice questions. Methodology A sensitivity analysis was applied to extract useful knowledge from the relevance of the characteristics (i.e., the input variables) used for the data mining process to compute the score. Contribution Such knowledge helps the teachers to decide which format they must consider with respect to the objectives and expected students results. Findings The results shown a set of factors that influence the discrepancy between answers in both formats. Recommendationsfor Practitioners Teachers can make an informed decision about whether to choose multiplechoice questions or constructed-response taking into account the results of this study. Recommendations for Researchers In this study a block of exams with CR questions is verified to complement the area of learning, returning greater performance in the evaluation of students and improving the teaching-learning process. Impact on Society The results of this research confirm the findings of several other researchers that the use of ICT and the application of MCQ is an added value in the evaluation process. In most cases the student is more likely to succeed with MCQ, however if the teacher prefers to evaluate with CR other research approaches are needed. Future Research Future research must include other question formats.info:eu-repo/semantics/publishedVersio

    Biometria de frutos em um plantio de açaí em Porto Velho, Rondônia.

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    O objetivo deste trabalho foi realizar a biometria de frutos em um plantio de açaí em Porto Velho, Rondônia

    Effect of hyperbaric stress on yeast morphology: Study by automated image analysis

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    The effects of hyperbaric stress on the morphology of Saccharomyces cerevisiae were studied in batch cultures under pressures between 0.1 MPa and 0.6 MPa and different gas compositions (air, oxygen, nitrogen or carbon dioxide), covering aerobic and anaerobic conditions. A method using automatic image analysis for classification of S. cerevisiae cells based on their morphology was developed and applied to experimental data. Information on cell size distribution and bud formation throughout the cell cycle is reported. The results show that the effect of pressure on cell activity strongly depends on the nature of the gas used for pressurization. While nitrogen and air to a maximum of 0.6 MPa of pressure were innocuous to yeast, oxygen and carbon dioxide pressure caused cell inactivation, which was confirmed by the reduction of bud cells with time. Moreover, a decrease in the average cell size was found for cells exposed for 7.5 h to 0.6 MPa CO2.CAPES and CNPq (Brazil). Fundação para a Ciência e Tecnologia (Portugal)

    On the nature of the (de)coupling of the magnetostructural transition in Er5_5Si4_4

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    In this report, a successful thermodynamical model was employed to understand the structural transition in Er5_5Si4_4, able to explain the decoupling of the magnetic and structural transition. This was achieved by the DFT calculations which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure as the stable phase at low temperatures as verified experimentally with a ΔF0=−\Delta F_0 = -0.262 eV. Finally, it was achieved a variation of Seebeck coefficient (∼\sim 6 μ\muV) at the structural transition which allow to conclude that the electronic entropy variation is negligible in the transition.Comment: 17 pages, 3 figures, 1 tabl

    Observation of confined current ribbon in JET plasmas

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    we report the identification of a localised current structure inside the JET plasma. It is a field aligned closed helical ribbon, carrying current in the same direction as the background current profile (co-current), rotating toroidally with the ion velocity (co-rotating). It appears to be located at a flat spot in the plasma pressure profile, at the top of the pedestal. The structure appears spontaneously in low density, high rotation plasmas, and can last up to 1.4 s, a time comparable to a local resistive time. It considerably delays the appearance of the first ELM.Comment: 10 pages, 6 figure

    Long-Term weight loss and metabolic syndrome remission after bariatric surgery: The effect of sex, age, metabolic parameters and surgical technique-a 4-year follow-up study

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    Introduction: Bariatric surgery is an effective treatment for morbid obesity and its metabolic related comorbidities. However, the literature reports inconsistent results regarding weight loss (WL) and the resolution of comorbidities associated with obesity. Objective: We aim to evaluate long-Term differences in WL between different surgical techniques and the impact of each surgical technique on metabolic parameters (type 2 diabetes mellitus [T2DM], dyslipidemia,hypertension, and metabolic syndrome). We also aim to evaluate the effect of baseline clinical characteristics in WL and in the evolution of metabolic syndrome (MetS) components. Our hypothesis is that different types of surgery have different effects on WL and the prevalence of comorbidities over time. Methods: We retrospectively evaluated WL and metabolic parameter remission (T2DM, dyslipidemia, hypertension, and MetS) during 4 years in 1,837 morbidly obese patients (females, 85%; age, 42.5 ± 10.6 years; BMI, 44.0 ± 5.8) who underwent bariatric surgery (Roux-en-Y gastric bypass [RYGB], laparoscopic sleeve gastrectomy [LSG], and laparoscopic adjustable gastric band [LAGB]). Results: The mean percentage of WL for RYGB, LSG, and LAGB was, respectively, 32.9 ± 8.7, 29.8 ± 9.8, and 16.2 ± 9.6 at 12 months and 30.6 ± 9.1, 22.7 ± 10.0, and 15.8 ± 10.8 at 48 months (p < 0.001), even after adjustment for baseline weight, BMI, age, and sex (p < 0.001). Women had more WL during the first 36 months (p = 0.013 and 0.007 at 12 and 36 months, respectively) and older patients had less WL compared to younger ones (p <0.001), except at 48 months. Patients with T2DM had less WL than those without diabetes after adjustment (sex, age, and surgical technique) during the same period. Patients with hypertension had less WL at 12 months (p = 0.009) and MetS at 24 months (p = 0.020) compared to those without these comorbidities. There was no significant difference regarding the presence of dyslipidemia in WL. The RYGB group showed better results for MetS resolution. Conclusion:During the 4-year follow-up, RYGB was the surgical procedure that caused the highest WL and MetS resolution

    Bariatric Surgery Impact on Cardiovascular Risk Factors: Is Age a Factor to Consider?

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    Introduction: Despite the abundance of data addressing the influence of patient's age on surgery-related complications, its impact on cardiometabolic outcomes following bariatric surgery has been overlooked. Methods: Retrospective unicentric study of 1,728 obese patients who underwent bariatric surgery between January 2010 and June 2015. Patients were divided in 3 age groups, according to their age at surgery: ?40 (n = 751), 40-59 (n = 879), and 60 years (n = 98). Parameters with cardiometabolic impact, such as body anthropometric measures, lipid profile, and glycemic status, before and 24 months after surgery, were compared between these groups. A multiple linear regression was performed, adjusting differences between groups for sex, surgery type, and body mass index variation. Results: The group ?40 years presented more weight loss (-35.4 ± 9.0 kg, p ? 0.001), greater BMI reduction (-15.8 ± 6.1 kg/m2, p ? 0.001), and larger changes in waist (-34 ± 13.8 cm, p ? 0.001) and hip circumferences (-28.7 ± 11.9 cm, p ? 0.05). The group of 60 years presented the heaviest reduction in fasting glucose (-17.7 ± 32.8 mg/dL, p ? 0.001) and HbA1c (0.7 ± 1.0, p ? 0.001), and also had a tendency to have the biggest changes in systolic blood pressure (-14.7 ± 18.7 mm Hg, p = 0.071). Conclusion: Patients with 60 years benefit the most from bariatric surgery regarding cardiometabolic parameters, presenting heavier reductions in fasting glucose, as well as HbA1c and a tendency towards a higher decrease in systolic blood pressure. No clinically significant differences in lipid profile were observed between groups. (c) 202
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