9,712 research outputs found
Regras variáveis na concordância verbal com a primeira pessoa do plural em comunidades do Rio Grande do Sul
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Students’ perceptions about a multimedia learning laboratory: an experience in teaching biology classes
This research aimed to assess students’ perceptions regarding a multimedialearning laboratory, after experiencing biology classes that used a different teaching approach. The survey involved 159 students between 15 and 17 years old. The methodology combined quantitative and qualitative approaches and obtained results by using a questionnaire and by conducting interviews, respectively. Results indicate that students have good perceptions about the laboratory. They consider it as relevant, authentic, challenging, and useful, with fun and easy-to-use resources. They also point out that it provides opportunities for reflection about their own learning. Results further indicate that boys and girls have similar perceptions about the laboratory, and that students from different years of secondary education do not follow a pattern in their preferences
Synthesis and structural characterization of a mimetic membrane-anchored prion protein
During pathogenesis of transmissible spongiform encephalopathies (TSEs) an abnormal form (PrPSc) of the host encoded prion protein (PrPC) accumulates in insoluble fibrils and plaques. The two forms of PrP appear to have identical covalent structures, but differ in secondary and tertiary structure. Both PrPC and PrPSc have glycosylphospatidylinositol (GPI) anchors through which the protein is tethered to cell membranes. Membrane attachment has been suggested to play a role in the conversion of PrPC to PrPSc, but the majority of in vitro studies of the function, structure, folding and stability of PrP use recombinant protein lacking the GPI anchor. In order to study the effects of membranes on the structure of PrP, we synthesized a GPI anchor mimetic (GPIm), which we have covalently coupled to a genetically engineered cysteine residue at the C-terminus of recombinant PrP. The lipid anchor places the protein at the same distance from the membrane as does the naturally occurring GPI anchor. We demonstrate that PrP coupled to GPIm (PrP-GPIm) inserts into model lipid membranes and that structural information can be obtained from this membrane-anchored PrP. We show that the structure of PrP-GPIm reconstituted in phosphatidylcholine and raft membranes resembles that of PrP, without a GPI anchor, in solution. The results provide experimental evidence in support of previous suggestions that NMR structures of soluble, anchor-free forms of PrP represent the structure of cellular, membrane-anchored PrP. The availability of a lipid-anchored construct of PrP provides a unique model to investigate the effects of different lipid environments on the structure and conversion mechanisms of PrP
A CONCORDÂNCIA VERBAL COM A PRIMEIRA PESSOA DO PLURAL EM PANAMBI E PORTO ALEGRE, RS
This is part of a project about several related morphosyntactic changesin Brazilian Portuguese using data from VARSUL data base. Two cities in RS areconsidered: Porto Alegre, the capital, and Panambi, a bilingual community. Thesample included 32 interviews stratified according to sex, age, and level of formaleducation. The variable investigated is verbal marking with first person pluralsubjects. The variants are: standard agreement (-mos ending) and twononstandard forms: zero and /s/ deleted -mo inflections. Supposing two differentvariable rules, we made three separate Varbrul analyses: a)contrasting the threevariants; b) contrasting zero inflection with both -mos and -mo endings takentogether; and c)contrasting only -mos and -mo endings. The distribution of thevariants was: 53% of standard tokens, 34% of -mo endings and only 13% of zeroinflection. Results showed different factor groups associated with zero inflectionand nonstandard -mo inflection, supporting the idea of having two separatevariable rules. The level of formal education turned out to be the only significantfactor group in common for both nonstandard forms. It was also highlighted in thethree-way comparison. Zero inflection was favoured only when the target wordhad antepenultimate stress, suggesting avoidance of this stress pattern. Thebilingual community had an effect only on zero inflection
A concordância verbal com a primeira pessoa do plural em Panambi e Porto Alegre, RS
This is part of a project about several related morphosyntactic changes in Brazilian Portuguese using data from VARSUL data base. Two cities in RS are considered: Porto Alegre, the capital, and Panambi, a bilingual community. The sample included 32 interviews stratified according to sex, age, and level of formal education. The variable investigated is verbal marking with first person plural subjects. The variants are: standard agreement (-mos ending) and two nonstandard forms: zero and /s/ deleted -mo inflections. Supposing two different variable rules, we made three separate Varbrul analyses: a)contrasting the three variants; b) contrasting zero inflection with both -mos and -mo endings taken together; and c)contrasting only -mos and -mo endings. The distribution of the variants was: 53% of standard tokens, 34% of -mo endings and only 13% of zero inflection. Results showed different factor groups associated with zero inflection and nonstandard -mo inflection, supporting the idea of having two separate variable rules. The level of formal education turned out to be the only significant factor group in common for both nonstandard forms. It was also highlighted in the three-way comparison. Zero inflection was favoured only when the target word had antepenultimate stress, suggesting avoidance of this stress pattern. The bilingual community had an effect only on zero inflection
Relationship between FEV1 change and patient-reported outcomes in randomised trials of inhaled bronchodilators for stable COPD: a systematic review.
BACKGROUND: Interactions between spirometry and patient-reported outcomes in COPD are not well understood. This systematic review and study-level analysis investigated the relationship between changes in FEV1 and changes in health status with bronchodilator therapy.
METHODS: Six databases (to October 2009) were searched to identify studies with long-acting bronchodilator therapy reporting FEV1 and health status, dyspnoea or exacerbations. Mean and standard deviations of treatment effects were extracted for each arm of each study. Relationships between changes in trough FEV1 and outcomes were assessed using correlations and random-effects regression modelling. The primary outcome was St George's Respiratory Questionnaire (SGRQ) total score.
RESULTS: Thirty-six studies (≥ 3 months) were included. Twenty-two studies (23,654 patients) with 49 treatment arms each contributing one data point provided SGRQ data. Change in trough FEV1 and change in SGRQ total score were negatively correlated (r = -0.46, p < 0.001); greater increases in FEV1 were associated with greater reductions (improvements) in SGRQ. The correlation strengthened with increasing study duration from 3 to 12 months. Regression modelling indicated that 100 mL increase in FEV1 (change at which patients are more likely to report improvement) was associated with a statistically significant reduction in SGRQ of 2.5 (95% CI 1.9, 3.1), while a clinically relevant SGRQ change (4.0) was associated with 160.6 (95% CI 129.0, 211.6) mL increase in FEV1. The association between change in FEV1 and other patient-reported outcomes was generally weak.
CONCLUSIONS: Our analyses indicate, at a study level, that improvement in mean trough FEV1 is associated with proportional improvements in health status
Evaluation of bedtime vs. morning levothyroxine intake to control hypothyroidism in older patients : a pragmatic crossover randomized clinical trial
Introduction: Drug scheduling in older adults can be a challenge, especially considering polypharmacy, physical dependency, and possible drug interactions. Properly testing alternative treatment regimens could therefore help to overcome treatment barriers. Hypothyroidism is a prevalent condition in older adults, however, studies evaluating Lthyroxine treatment effectiveness in this specific age group are still lacking. Most studies testing an evening administration of levothyroxine were mainly composed of younger adults. Therefore, this trial is aimed to assess if evening levothyroxine (LT4) administration can effectively control hypothyroidism in older patients. Materials and Methods: A randomized crossover clinical trial was conducted between June 2018 and March 2020 at the Hospital de ClÃnicas de Porto Alegre, a teaching hospital in Brazil, to compare the efficacy of morning and evening administration of LT4 for hypothyroidism control in older patients. The study protocol is published elsewhere. A total of 201 participants, ≥60 years old, with primary hypothyroidism treated with LT4 for at least 6 months and on stable doses for at least 3 months were included. Participants were randomly assigned to a starting group of morning LT4 intake (60min before breakfast) or bedtime LT4 intake (60min after the last meal). After ≥12 weeks of follow-up, a crossover between strategies was performed. The primary outcome was the change in serum thyrotropin (Thyroid-Stimulating Hormone; TSH) levels after 12 weeks of each LT4 administration regimen. Results: A total of 201 participants with mean age of 72.4 ± 7.2 years were included, out of which 84.1% were women; baseline characteristics and frequency of controlled hypothyroidism were similar between groups. Mean baseline TSH was 3.43 ± 0.25 mUI/L. In total, 118 participants attended three meetings, allowing 135 comparisons by crossover analytic strategy. Mean TSH levels after follow-up were 2.95 ± 2.86 in the morning group and 3.64 ± 2.86 in the bedtime group, p = 0.107. Discussion: Thyroid-Stimulating Hormone levels and frequency of controlled hypothyroidism were similar during the follow-up period regardless of the treatment regimen (morning or bedtime)
Using a simple expert system to assist a powered wheelchair user
A simple expert system is described that helps wheelchair users to drive their wheelchairs. The expert system takes data in from sensors and a joystick, identifies obstacles and then recommends a safe route. Wheelchair users were timed while driving around a variety of routes and using a joystick controlling their wheelchair via the simple expert system. Ultrasonic sensors are used to detect the obstacles. The simple expert system performed better than other recently published systems. In more difficult situations, wheelchair drivers did better when there was help from a sensor system. Wheelchair users completed routes with the sensors and expert system and results are compared with the same users driving without any assistance. The new systems show a significant improvement
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