727 research outputs found

    Development and formative evaluation of an instructional simulation of adiabatic processes

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    The purpose of this research was to develop a computer-based instructional simulation of adiabatic processes and to study the effects of selected characteristics of the simulation on students conceptual development, problem solving and transfer. To study these issues the related literature was reviewed, a simulation was developed and a two-pronged research study was employed. From the review of literature and constructivist theory, a simulation to facilitate active and situated learning was developed. It included the features of multiple representations, interaction, and authentic tasks;The subjects for the study were students enrolled in a beginning meteorology course at Iowa State University. An experimental study was conducted comparing achievement measures of two groups who used different versions of the simulation and a control group who did not use the simulation. In addition, selected students were interviewed to gain a deeper understanding of their use of the simulation. The performances of the groups were compared on scores from a posttest and weather forecasts. As expected, since the simulation was not integrated into classroom activities, there were no statistically significant differences between the groups;Interview data supported the design and future use of the simulation. Four of the five students saw the task as being authentic. The multiple representations were used by the students to construct knowledge across representations and to choose their own mode of representation for exploring the simulation. Of the five students interviewed, only one had used an effective problem solving strategy. This student also demonstrated a better understanding of how to transfer newly-gained knowledge to weather forecast exercises. Two other students were poised for improvement of their problem solving strategies, having the basic strategy but needing refinement, and the other two were in need of basic instruction and guiDance;;This study clearly revealed a serious weakness in student\u27s problem-solving skills as well as the value of the simulated environment for revealing those weaknesses. It is recommended the simulation be used in future studies which address the issues of integrating simulations into classroom activities so that optimal learning of the concepts and optimal development of problem-solving strategies will occur

    Investigating coherence about nature of science in science curriculum documents : Taiwan as a case study

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    Abstract: The article focuses on the analysis of curriculum documents from Taiwan to investigate how benchmarks for learning nature of science (NOS) are positioned in different versions of the science curricula. Following a review of different approaches to the conceptualization of NOS and the role of NOS in promoting scientific literacy, an empirical study is reported to illustrate how the science curriculum documents represent different aspects of NOS. The article uses the family resemblance approach (FRA) as the account of NOS and adapts it for analysis of the curriculum documents. The FRA defines NOS as cognitive-epistemic and social-institutional systems that serve as constructs of knowledge categories with a high level of interconnectedness. The FRA was used as an analytical tool for investigating two sets of Taiwanese curriculum guidelines published 10 years apart, providing an opportunity to discuss how NOS is addressed in the curriculum reforms. The findings show a shift away from the excessive centralization of the cognitive-epistemic system to a consideration of the socialinstitutional system. Modifications to the benchmarks are proposed in order to achieve a more holistic and progressive approach to NOS. The article contributes to studies on NOS in science education by illustrating how the FRA can act as a tool for exploring interconnectedness of NOS ideas in the curriculum

    Conceptualizing socioscientific decision making from a review of research in science education

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    Abstract: This article proposes a theoretical framework for conceptualizing socioscientific decision making, reviews current research in this area, and intends to shed some light on the instructional design for the classroom implementation of socioscientific decision making. The framework involves 3 phases: formulate the decision-making space, posit a decision-making strategy, and reflect on the decision-making process. A total of 24 articles that specifically focused on socioscientific decision making were included. They were classified into 2 groups. The first group explored students’ socioscientific decision-making behavior and its relationships with their cognitive conditions. The second examined the effectiveness of the interventions, that is, task conditions. The analysis showed that most of the studies in both groups focused on phase 1 and studied 3 research themes: informal reasoning, evidence-based reasoning, and social interactions. The findings indicated the challenges phases 1 and 2 posed to students, such as prioritizing criteria and employing a suitable decision-making strategy. Two cognitive conditions, scientific knowledge and scientific epistemological beliefs, appeared to have a more direct impact on evidence-based reasoning rather than on informal reasoning. Group 2 studies designed various interventions and looked into divergent socioscientific decision-making performances across 3 phases. The framework helps conceptualize socioscientific decision making in a more structural and holistic way. The content review provides instructional insights for the socioscientific decision-making process and suggests several future research directions

    Theoretical Study of High Performance Germanium Nanowire Quantum Dot

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    In this report, we demonstrate that Ge-NWQD (nanowire quantum dots) at low temperatures exhibit apparent Coulomb oscillations than that in Si-NWQD. These oscillations gradually disappear as the temperature increases, indicating the influence of phonon scattering. The increase in Coulomb oscillations enables the device to exhibit multi-level characteristics at low voltage in quantum flash, and the lower barrier high and high mobility of Ge make it advantageous for increasing the storage capacity of quantum flash devices. This research provides design guidelines for optimization of high-performance quantum flash devices.Comment: 2pages,5figures,Silicon Nanoelectronics Workshop 2023(SNW

    Epilogue for the IJSME Special Issue: Metacognition for science and mathematics learning in technology-infused learning environments

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    Epilogue for the IJSME Special Issue: Metacognition for science and mathematics learning in technology-infused learning environment

    Rapamycin attenuates PLA2R activation-mediated podocyte apoptosis via the PI3K/AKT/mTOR pathway

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    Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in adults without diabetes. Primary MN has been associated with circulating antibodies against native podocyte antigens, including phospholipase A2 receptor (PLA2R); however, precision therapy targeting the signaling cascade of PLA2R activation is lacking. Both PLA2R and the mammalian target of rapamycin (mTOR) exist in podocytes, but the interplay between these two proteins and their roles in MN warrants further exploration. This study aimed to investigate the crosstalk between PLA2R activation and mTOR signaling in a human podocyte cell line. We demonstrated that podocyte apoptosis was induced by Group IB secretory phospholipase A2 (sPLA2IB) in a concentration- and time-dependent manner via upregulation of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and mTOR, and inhibited by rapamycin or LY294002. Furthermore, aberrant activation of the PI3K/AKT/mTOR pathway triggers both extrinsic (caspase-8 and caspase-3) and intrinsic (Bcl-2-associated X protein [BAX], B-cell lymphoma 2 [BCL-2], cytochrome c, caspase-9, and caspase-3) apoptotic cascades in podocytes. The therapeutic implications of our findings are that strategies to reduce PLA2R activation and PI3K/AKT/mTOR pathway inhibition in PLA2R-activated podocytes help protect podocytes from apoptosis. The therapeutic potential of rapamycin shown in this study provides cellular evidence supporting the repurposing of rapamycin for MN treatment

    Comparison of diffusion-weighted imaging and contrast-enhanced T1-weighted imaging on a single baseline MRI for demonstrating dissemination in time in multiple sclerosis

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    BACKGROUND: The 2010 Revisions to the McDonald Criteria have established that dissemination in time (DIT) of multiple sclerosis (MS) can be demonstrated by simultaneous presence of asymptomatic gadolinium-enhancing and nonenhancing lesions on a single magnetic resonance imaging (MRI). However, gadolinium-based contrast agents (GBCAs) have contraindications. Diffusion-weighted imaging (DWI) can detect diffusion alterations in active inflammatory lesions. The purpose of this study was to investigate if DWI can be an alternative to contrast-enhanced T1-weighted imaging (CE T1WI) for demonstrating DIT in MS. METHODS: We selected patients with clinically definite MS and evaluated their baseline brain MRI. Asymptomatic lesions were identified as either hyperintense or nonhyperintense on DWI and enhancing or nonenhancing on CE T1WI. Fisher’s exact test was performed to determine whether the hyperintensity on DWI was related to the enhancement on CE T1WI (P < 0.05). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the DWI to predict lesion enhancement were calculated. RESULTS: Twenty-two patients with 384 demyelinating lesions that were hyperintense on T2-weighted imaging and more than 3 mm in size were recruited. The diffusion hyperintensity and lesion enhancement were significantly correlated (P <0.001). The sensitivity, specificity, PPV, NPV and accuracy were 100%, 67.9%, 32.3%, 100% and 72.1%, respectively. CONCLUSIONS: A hyperintense DWI finding does not necessarily overlap with contrast enhancement. There are many false positives, possibly representing other stages of lesion development. Although DWI may not replace CE T1WI imaging to demonstrate DIT due to the low PPV, it may serve as a screening MRI sequence where the use of GBCAs is a concern

    Outcomes and prognostic factors of simple partial cystectomy for localized bladder urothelial cell carcinoma

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    AbstractRadical cystectomy has remained the gold standard for recurrent superficial or muscle invasive bladder tumor. However, partial cystectomy still has a role in those who reject or have contraindications for radical cystectomy. In this study, we sought to identify predictors of bladder recurrence and overall survival after simple partial cystectomy. We included 27 patients with bladder tumor who received simple partial cystectomy without pelvic lymph node dissection between March 2000 and September 2013. Adjuvant chemotherapy or radiation therapy was prescribed according to the pathological results. Parameters were compared on the basis of bladder recurrence and overall survival. During a mean follow-up time of 39 months, five patients (18.5%) experienced bladder recurrence. An older age, a higher pathological stage, positive surgical margins, and distant metastases were significant predictors of overall survival (p = 0.031, p = 0.001, p = 0.001, and p = 0.011, respectively). Meanwhile, previous bladder instillation and positive surgical margins were significant predictors of bladder recurrence (p = 0.026 and p = 0.027, respectively). The rate of consecutive distant metastases (33.3%) was almost twice the rate of bladder recurrence (18.5%), and six patients developed consecutive distant metastases without first experiencing bladder recurrence. In patients who received a simple partial cystectomy as an alternative treatment, previous bladder instillation and positive surgical margins were significant predictors of bladder recurrence. Patients with an older age, positive surgical margins, and consecutive distant metastases had worse overall survival. Partial cystectomy with routine lymph node dissection may be a better option for achieving favorable long-term outcomes

    D2ADA: Dynamic Density-aware Active Domain Adaptation for Semantic Segmentation

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    In the field of domain adaptation, a trade-off exists between the model performance and the number of target domain annotations. Active learning, maximizing model performance with few informative labeled data, comes in handy for such a scenario. In this work, we present D2ADA, a general active domain adaptation framework for semantic segmentation. To adapt the model to the target domain with minimum queried labels, we propose acquiring labels of the samples with high probability density in the target domain yet with low probability density in the source domain, complementary to the existing source domain labeled data. To further facilitate labeling efficiency, we design a dynamic scheduling policy to adjust the labeling budgets between domain exploration and model uncertainty over time. Extensive experiments show that our method outperforms existing active learning and domain adaptation baselines on two benchmarks, GTA5 -> Cityscapes and SYNTHIA -> Cityscapes. With less than 5% target domain annotations, our method reaches comparable results with that of full supervision.Comment: 14 pages, 5 figure

    The Observation for Ocular Surface Diseases in Respiratory Care Center in One Regional Teaching Hospital in Southern Taiwan

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    Abstract: Purpose: To discover the incidence of ocular surface diseases in the RCC in one region hospital in southern Taiwan. Methods: A prospective study was performed from January 2014 to May 2014. We recorded the causes of admission, eyelid position, abnormal findings of the conjunctiva and cornea. Besides, we also collected data about age, sex, sedation score, the intubation or not, the ventilator setting, date of admission, endotracheal tube or tracheostomy used et al. Results: Total 30 patients were examined in RCC. The mean age of the patients was 60.5 years (range 32-82). 18 patients were male and 12 were female. 24 patients had been sedated or non-sedated with various ventilators. 6 patients were in T-piece trial. 22 patients had tube intubation and 8 patients had received tracheostomy. Mean stay time was 20.5 days. The percent of ocular surface diseases were 33.3% (10/30), and lagophthalmos was observed about 33.3% due to sedation. 23.3% (7/30) patients had conjunctival problems and 26.6% (8/30) had keratopathy. We found that 80% (8/10) patients with lagophthalmos had eye disorders. The endotracheal tube intubation group had a relatively higher incidence of ocular surface diseases (7/2232%). If the sedation score lower than 8, 26 % patients may have eye diseases. Conclusion: The incidence of ocular surface diseases is closely related to heavy sedation or muscle relaxants. The assessment of eyelid position in relation to the ocular surface disease is the most important observation required in RCC. How to set up the routine protocol for eye care for the staff in ICU becomes valuable and serious today. We must keep in mind that prevention is always better than cure
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