8,860 research outputs found

    Two teacher educatorsā€™ approaches to developing preservice elementary teachersā€™ mathematics assessment literacy: Intentions, outcomes, and new learning

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    The purpose of this study was to examine and reflect on two teacher educatorsā€™ approaches to developing preservice elementary teachersā€™ mathematics assessment literacy. We explored the similarities and differences in preservice teachersā€™ conceptions of good assessment practices and their critique of assessment items. We found that we, as course instructors, had different assumptions pertaining to the role of preservice teachers in the development of assessment and offered different assessment-related course activities. Despite these differences, there were more similarities than differences between the two groups of the preservice teachers with regard to their overall perceptions about good assessment practices and their critique of assessment items. However, we also observed differences in the criteria they used in critiquing assessment items. Discussions and implications are presented in accordance with these findings as a means to improve our own teaching and student learning

    Fundamental Limits on Data Acquisition: Trade-offs between Sample Complexity and Query Difficulty

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    We consider query-based data acquisition and the corresponding information recovery problem, where the goal is to recover kk binary variables (information bits) from parity measurements of those variables. The queries and the corresponding parity measurements are designed using the encoding rule of Fountain codes. By using Fountain codes, we can design potentially limitless number of queries, and corresponding parity measurements, and guarantee that the original kk information bits can be recovered with high probability from any sufficiently large set of measurements of size nn. In the query design, the average number of information bits that is associated with one parity measurement is called query difficulty (dĖ‰\bar{d}) and the minimum number of measurements required to recover the kk information bits for a fixed dĖ‰\bar{d} is called sample complexity (nn). We analyze the fundamental trade-offs between the query difficulty and the sample complexity, and show that the sample complexity of n=cmaxā”{k,(klogā”k)/dĖ‰}n=c\max\{k,(k\log k)/\bar{d}\} for some constant c>0c>0 is necessary and sufficient to recover kk information bits with high probability as kā†’āˆžk\to\infty

    Chronic rhinosinusitis with nasal polyps in older adults : clinical presentation, pathophysiology, and comorbidity

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    Purpose of Review Chronic rhinosinusitis and nasal polyps (CRSwNP) is a common condition that significantly affects patients' life. This work aims to provide an up-to-date overview of CRSwNP in older adults, focusing on its aging-related clinical presentations, pathophysiology, and comorbidity associations including asthma. Recent Findings Recent large population-based studies using nasal endoscopy have shown that CRSwNP is a mostly late-onset disease. Age-related changes in physiologic functions, including nasal epithelial barrier dysfunction, may underlie the incidence and different clinical presentations of CRSwNP in older adults. However, there is still a paucity of evidence on the effect of aging on phenotypes and endotypes of CRSwNP. Meanwhile, late-onset asthma is a major comorbid condition in patients with CRSwNP; they frequently present with type 2 inflammatory signatures that are refractory to conventional treatments when they are comorbid. However, as they are more commonly non-atopic, causative factors other than classical atopic sensitization, such as Staphylococcus aureus specific IgE sensitization, are suggested to drive the type 2 inflammation. There are additional comorbidity associations in older patients with CRSwNP, including those with chronic otitis media and head and neck malignancy. Age is a major determinant for the incidence and clinical presentations of CRSwNP. Given the heterogeneity in phenotypes and endotypes, longitudinal investigations are warranted to elucidate the effects of aging on CRSwNP

    Determination of Refrigerant Path Number for Fin-tube Condenser Considering Heat Transfer Performance and Pumping Power

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    Fin-tube heat exchangers are widely used in air-conditioners and heat pumps, which are constructed with a lot of tubes. Refrigerant circuit of heat exchanger with numerous pipe can be constructed by many methods. Refrigerant circuit design is usually determined designerā€™s experience and case by case test without guides. The number of path affects largely on heat exchanger performance. In this paper, design methodology for optimum number of path is suggested by relating convective thermal resistance and pumping power. Suggested methodology is described through an example and verified by various refrigerant circuit simulation results

    High-Throughput Screening of Acyl-CoA Thioesterase I Mutants Using a Fluid Array Platform

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    Screening target microorganisms from a mutated recombinant library plays a crucial role in advancing synthetic biology and metabolic engineering. However, conventional screening tools have several limitations regarding throughput, cost, and labor. Here, we used the fluid array platform to conduct high-throughput screening (HTS) that identified Escherichia coli ???TesA thioesterase mutants producing elevated yields of free fatty acids (FFAs) from a large (106) mutant library. A growth-based screening method using a TetA-RFP fusion sensing mechanism and a reporter-based screening method using high-level FFA producing mutants were employed to identify these mutants via HTS. The platform was able to cover >95% of the mutation library, and it screened target cells from many arrays of the fluid array platform so that a post-analysis could be conducted by gas chromatography. The ???TesA mutation of each isolated mutant showing improved FFA production in E. coli was characterized, and its enhanced FFA production capability was confirmed

    Assessing phonological processing abilities for the prediction of future reading skills: a meta-analysis

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    This study evaluated three phonological processing abilities - phonological awareness, phonological coding in working memory, and phonological coding in lexical access - to predict future reading skills, using meta-analysis. Two research questions were addressed: (1) Which of the three phonological processing abilities contributes more to the prediction of risk for reading failure? (2) Are the different phonological processing abilities related independently to reading? A total of 33 longitudinal correlational studies (23 published studies and 10 unpublished studies) were included in the meta-analysis. Results confirmed the strong relation between phonological processing abilities and reading skills and showed that of the three phonological processing abilities, phonological awareness was the better predictor of word decoding and phonological coding in lexical access was the better predictor of reading comprehension. Results of a path analysis indicated that the three phonological processing abilities were independently related to two kinds of reading skill (i.e., word decoding and reading comprehension) with nonzero path coefficients. These results suggest that each phonological processing ability can contribute to the prediction of future reading skills, and each may provide a possible intervention strategy for young children with reading disabilities

    Brain-Driven Representation Learning Based on Diffusion Model

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    Interpreting EEG signals linked to spoken language presents a complex challenge, given the data's intricate temporal and spatial attributes, as well as the various noise factors. Denoising diffusion probabilistic models (DDPMs), which have recently gained prominence in diverse areas for their capabilities in representation learning, are explored in our research as a means to address this issue. Using DDPMs in conjunction with a conditional autoencoder, our new approach considerably outperforms traditional machine learning algorithms and established baseline models in accuracy. Our results highlight the potential of DDPMs as a sophisticated computational method for the analysis of speech-related EEG signals. This could lead to significant advances in brain-computer interfaces tailored for spoken communication

    Mitochondrial DNA Copy Number in Peripheral Blood Is Independently Associated with Visceral Fat Accumulation in Healthy Young Adults

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    Aims. Visceral obesity is associated with an increased risk of cardiometabolic diseases and it is important to identify the underlying mechanisms. There is growing evidence that mitochondrial dysfunction is associated with metabolic disturbances related to visceral obesity. In addition, maintaining mitochondrial DNA (mtDNA) copy number is important for preserving mitochondrial function. Therefore, we investigated the relationship between mtDNA copy number and visceral fat in healthy young adults. Methods. A total of 94 healthy young subjects were studied. Biomarkers of metabolic risk factors were assessed along with body composition by computed tomography. mtDNA copy number was measured in peripheral leukocytes using real-time polymerase chain reaction (PCR) methods. Results. The mtDNA copy number correlated with BMI (r=-0.22, P=0.04), waist circumference (r=-0.23, P=0.03), visceral fat area (r=-0.28, P=-0.01), HDL-cholesterol levels (r=0.25, P=0.02), and hs-CRP (r=0.32, P=0.02) after adjusting for age and sex. Both stepwise and nonstepwise multiple regression analyses confirmed that visceral fat area was independently associated with mtDNA copy number (Ī²=-0.33, P<0.01, Ī²=0.32, and P=0.03, resp.). Conclusions. An independent association between mtDNA content and visceral adiposity was identified. These data suggest that mtDNA copy number is a potential predictive marker for metabolic disturbances. Further studies are required to understand the causality and clinical significance of our findings
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