Diagnostic accuracy of UriSed automated urine microscopic sediment analyzer and dipstick parameters in predicting urine culture test results

Introduction

Urinary tract infection (UTI) is one of the most common types of infection. Currently, diagnosis is primarily based on microbiologic culture, which is time- and labor-consuming. The aim of this study was to assess the diagnostic accuracy of urinalysis results from UriSed (77 Electronica, Budapest, Hungary), an automated microscopic image-based sediment analyzer, in predicting positive urine cultures.

Materials and methods:

We examined a total of 384 urine specimens from hospitalized patients and outpatients attending our hospital on the same day for urinalysis, dipstick tests and semi-quantitative urine culture. The urinalysis results were compared with those of conventional semi-quantitative urine culture.

Results:

Of 384 urinary specimens, 68 were positive for bacteriuria by culture, and were thus considered true positives. Comparison of these results with those obtained from the UriSed analyzer indicated that the analyzer had a specificity of 91.1%, a sensitivity of 47.0%, a positive predictive value (PPV) of 53.3% (95% confidence interval (CI) = 40.8–65.3), and a negative predictive value (NPV) of 88.8% (95% Cl = 85.0–91.8%). The accuracy was 83.3% when the urine leukocyte parameter was used, 76.8% when bacteriuria analysis of urinary sediment was used, and 85.1% when the bacteriuria and leukocyturia parameters were combined. The presence of nitrite was the best indicator of culture positivity (99.3% specificity) but had a negative likelihood ratio of 0.7, indicating that it was not a reliable clinical test.

Conclusions:

Although the specificity of the UriSed analyzer was within acceptable limits, the sensitivity value was low. Thus, UriSed urinalysis results do not accurately predict the outcome of culture.     

Science teacher candidates’ perceptions about roles and nature of scientific models

Background: Scientific models have important roles in science and science education. For scientists, they provide a means for generating new knowledge or function as an accessible summary of scientific studies. In science education, on the other hand, they are accessible representations of abstract concepts, and are also organizational frameworks to teach and learn inaccessible facts. As being indispensable parts of learning and doing science, use of scientific models in science classes should be reinforced. At this point, uncovering pre-service science teachers’ (PSTs) understandings of scientific models are of great importance since they will design and conduct teaching situations for their students. Purpose: The study aimed to provide an answer to the research question: What understandings do PSTs possess about scientific models? Sample: The sample of the study consisted of 14 PSTs enrolled in an Elementary Science Education program in a public university in Ankara, Turkey. Design and methods: Data were collected by using an open-item instrument and semi-structured interviews, and were analyzed by using qualitative data analysis methods. Results: Findings showed that PSTs held fragmented views of models by having informed views in some aspects while having naïve views on others. That is, although they displayed a constructivist orientation by acknowledging the presence of multiple models for the same phenomenon depending on scientists’ perspectives or creativity involved in the production of scientific knowledge, PSTs also expressed logical positivist views by believing that models should be close to the real phenomena that they represent. Findings further revealed that PSTs generally conceptualized models’ materialistic uses, yet they did not think much about their theoretical and conceptual uses. It was observed that roles like reifying and visualizing were overestimated and models were dominantly characterized as three-dimensional representations. Conclusions: It is clear that PSTs, having difficulties in grasping the concept of models, would possibly have problems in planning their lessons effectively and would not develop accurate concepts in their students. These findings apparently support the need for appropriate pedagogic training of PSTs to scientifically reflect on and professionally make use of models in science classes.     

Finding the Hook: Computer Science Education in Elementary Contexts

The purpose of this study was to investigate how elementary teachers with little knowledge of computer science (CS) and project-based learning (PBL) experienced integrating CS through PBL as a part of a standards-based elementary curriculum in Grades 3–5. The researchers used qualitative constant comparison methods on field notes and reflections to describe the teachers' participation in professional development to create CS-infused projects to be implemented with their students. Categories that emerged included standards integration, student autonomy, and challenges of infrastructure and time. The data are from the first 6 months of a 3-year, National Science Foundation-funded project. (Keywords: computer science, project-based learning, integration, elementary curriculum)     

Preservice Science Teachers’ Epistemological Beliefs and Informal Reasoning Regarding Socioscientific Issues

This study investigated preservice elementary science teachers’ (PSTs) informal reasoning regarding socioscientific issues (SSI), their epistemological beliefs, and the relationship between informal reasoning and epistemological beliefs. From several SSIs, nuclear power usage was selected for this study. A total of 647 Turkish PSTs enrolled in three large universities in Turkey completed the open-ended questionnaire, which assessed the participants’ informal reasoning about the target SSI, and Schommer’s (1990) Epistemological Questionnaire. The participants’ epistemological beliefs were assessed quantitatively and their informal reasoning was assessed both qualitatively and quantitatively. The findings revealed that PSTs preferred to generate evidence-based arguments rather than intuitive-based arguments; however, they failed to generate quality evidence and present different types of evidence to support their claims. Furthermore, among the reasoning quality indicators, PSTs mostly generated supportive argument construction. Regarding the use of reasoning modes, types of risk arguments and political-oriented arguments emerged as the new reasoning modes. The study demonstrated that the PSTs had different epistemological beliefs in terms of innate ability, omniscient authority, certain knowledge, and quick learning. Correlational analyses revealed that there was a strong negative correlation between the PSTs’ certain knowledge and counterargument construction, and there were negative correlations between the PSTs’ innate ability, certain knowledge, and quick learning dimensions of epistemological beliefs and their total argument construction. This study has implications for both science teacher education and the practice of science education. For example, PST teacher education programs should give sufficient importance to training teachers that are skillful and knowledgeable regarding SSIs. To achieve this, specific SSI-related courses should form part of science teacher education programs.