Effective Implementation of ePortfolios: The Development of ePortfolios to Support Online Learning

This article discusses the ePortfolio system for grades 9–12 at the Virtual Learning Academy Charter School (VLACS). ePortfolio implementation at VLACS developed from an Advisory course curriculum that supports students' journey toward becoming college, career, and citizenship ready. We provide a unique perspective for implementation in that VLACS is completely online. Drawing from experiences in brick-and-mortar schools, online instruction, and research on digital portfolio programs, we utilize online portfolios to build a virtual community and engage students in their learning. The article summarizes key components to ePortfolio implementation and highlights how ePortfolios enable VLACS students to both reflect on their experience as learners and demonstrate academic and professional competencies.     

随机扩增多态性DNA技术研究发现二氧化钛纳米颗粒对西葫芦具有基因毒性

研究目的：二氧化钛（TiO2）纳米颗粒已经广泛应用于化妆品、防晒霜、涂料和牙膏等。这些纳米颗粒性质非常稳定,能在废水和生物固体中转移和分散。现有研究表明,TiO2纳米颗粒对动物正常生理活动具有毒性等负面作用。但是,它们对植物是否具有毒性特别是是否会产生植物基因毒性至今尚不清楚。因此,本文使用随机扩增多态性DNA技术研究TiO2纳米颗粒是否对西葫芦具有基因毒性,为TiO2纳米颗粒排放进入环境后的潜在植物毒性风险评价提供依据。 创新要点：首次发现了TiO2纳米颗粒对西葫芦具有基因毒性。 重要结论：采用随机扩增多态性DNA技术,发现TiO2纳米颗粒污染处理的西葫芦样品与未处理样品的基因组DNA图谱相比,不仅在谱带强度有明显差异,而且存在谱带消失和新谱带产生现象,表明TiO2纳米颗粒对西葫芦具有基因毒性。     

Toward a justice-centered ambitious teaching framework: Shaping ambitious science teaching to be culturally sustaining and productive in a rural context

We find ourselves at a time when the need for transformation in science education is aligning with opportunity. Significant science education resources, namely the Next Generation Science Standards (NGSS) and the Ambitious Science Teaching (AST) framework, need an intentional aim of centering social justice for minoritized communities and youth as well as practices to enact it. While NGSS and AST provide concrete guidelines to support deep learning, revisions are needed to explicitly promote social justice. In this study, we sought to understand how a commitment to social justice, operationalized through culturally sustaining pedagogy (Paris, Culturally sustaining pedagogies and our futures. The Educational Forum, 2021; 85, pp. 364–376), might shape the AST framework to promote more critical versions of teaching science for equity. Through a qualitative multi-case study, we observed three preservice teacher teams engaged in planning, teaching, and debriefing a 6-day summer camp in a rural community. Findings showed that teachers shaped the AST sets of practices in ways that sustained local culture and addressed equity aims: anchoring scientific study in phenomena important to community stakeholders; using legitimizing students' stories by both using them to plan the following lessons and as data for scientific argumentation; introducing local community members as scientific experts, ultimately supporting a new sense of pride and advocacy for their community; and supporting students in publicly communicating their developing scientific expertise to community stakeholders. In shaping the AST framework through culturally sustaining pedagogy, teachers made notable investments: developing local networks; learning about local geography, history, and culture; building relationships with students; adapting lessons to incorporate students' ideas; connecting with community stakeholders to build scientific collaborations; and preparing to share their work publicly with the community. Using these findings, we offer a justice-centered ambitious science teaching (JuST) framework that can deliver the benefits of a framework of practices while also engaging in the necessarily more critical elements of equity work.     

A microfluidic device to study cancer metastasis under chronic and intermittent hypoxia

Metastatic cancer cells must traverse a microenvironment ranging from extremely hypoxic, within the tumor, to highly oxygenated, within the host''s vasculature. Tumor hypoxia can be further characterized by regions of both chronic and intermittent hypoxia. We present the design and characterization of a microfluidic device that can simultaneously mimic the oxygenation conditions observed within the tumor and model the cell migration and intravasation processes. This device can generate spatial oxygen gradients of chronic hypoxia and produce dynamically changing hypoxic microenvironments in long-term culture of cancer cells.     

Neurotrophic factors

Unlike many other growth factors, neurotrophic factors do not stimulate the general proliferation of nerve cells but rather differentiation, both morphologically and biochemically. Recent research, including nerve cell cultures, has done much to reveal the nature and mode of actions of these factors and suggests ways in which they might be used in clinical medicine.     

Pedagogical content knowledge of experts and novices—what knowledge do they activate when analyzing science lessons?

In the current debate on pedagogical content knowledge (PCK), the term is used to refer to the context‐specific knowledge that teachers activate when reflecting on practice. Against the background of this debate, we conducted an empirical study and sought to answer the question of which knowledge experts and novices activated in assessing a videotaped lesson in relation to its effectiveness for learning. Our assumption was that the participants activate their PCK as a blending of content knowledge (CK) and pedagogical knowledge (PK) as suggested by Shulman's amalgam thesis. The participants (9 experts and 9 novices) were shown a lesson on optics, in which the law of refraction (Snell's law) was being studied. In a subsequent interview, the participants were asked to analyze the observed lesson. A qualitative and quantitative evaluation of the interviews showed that experts activated both CK and PK intensively and in this respect they differed significantly from novices. Further analysis of the expert statements also proved that they do not activate their CK and PK in isolation, but instead combine both kinds of knowledge together, in line with Shulman's amalgam thesis. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 55: 44–67, 2018     

Earth surface modeling for education: How effective is it? Four semesters of classroom tests with WILSIM-GC

This paper presents results from a randomized experimental design replicated over four semesters that compared students’ performance in understanding landform evolution processes as measured by the pretest to posttest score growth between two treatment methods: an online interactive simulation tool and a paper-based exercise. While both methods were shown to be effective at enhancing students’ learning of the landform concepts and processes, there was no statistically significant difference in score growth between the two instructional methods. However, the attitudinal survey indicated that students consistently favored the simulation approach over the paper-based exercise. With the simulation method, female students showed greater score growth than males, especially for test items requiring higher level thinking. This indicates that the visually rich interactive simulation tool may be integrated to better support female students’ learning in geoscience. Science major students generally outperformed non-science major students in terms of score growth, which suggests that background knowledge played an important role in realizing the potential of computer modeling in enhancing students’ learning. Sufficient scaffolding is necessary to maximize the effect of interactive earth surface modeling in geoscience education.