Search

The "Integrated Development of Key Competences" has been identified as the core idea in education to face competition in the 21st century. Similarly, reform efforts in science education emphasize the importance of integrating scientific practices and disciplinary core ideas. The learning progression (LP) is viewed as a robust tool to facilitate this integrated development. In this study, we integrated learning progressions of energy understanding and scientific explanation into an LP-based intervention to facilitate the instructional design of a middle school energy unit. A quasi-experiment was conducted with 3 teachers and their 184 students to examine the effects of the LP-based intervention on teacher instructional actions and student learning outcomes when compared to traditional instruction. Synthesizing video analysis and pre/posttests, the following results were obtained. (1) LP-based intervention influenced the treatment group's instructions. (2) The performance of both the treatment and comparison groups of students improved, but students in the treatment group demonstrated a better understanding of energy and were more competent in constructing scientific explanation. The article concludes by discussing implications for the future curriculum design and professional development of teachers.

Providing scientific explanations for natural phenomena is a fundamental aim of science; therefore, scientific explanation has been selected as one of the key practices in science education policy documents around the world. To further elaborate on existing educational frameworks of scientific explanation in K-12, we propose a learning progression of scientific explanation based on the Phenomenon-Theory-Data-Reasoning (PTDR) framework. To examine the validation of the PTDR framework for scientific explanation and the learning progression based on it, we developed the "Scientific Explanation Progression Assessment" to investigate students' performance (Grades 8-12 students, N = 4,554) on scientific explanations. A Rasch analysis and other statistical tests together indicated the validity of the PTDR framework for scientific explanation and the learning progression derived from this framework. We end with a discussion of the implications for future design of instruction and assessment.

China initiated a new round of science curriculum reform in 2017. Using the tripartite curriculum framework (including policy, programmatic, and classroom curriculum), we introduce and analyse China's policy curriculum and programmatic curriculum for science in primary school and senior high school, and describe the potential problems hindering the translation of these curricula into the classroom curriculum. We first identify the multiple aims of different stakeholders in science education, some of which influence the science policy curriculum. Then, we present the major changes in how the programmatic curriculum meets the policy curriculum. However, due to extracurricular factors, the current science curriculum reform may not unfold as expected. We end with a discussion of the three major characteristics of the revision process of science curriculum standards in China, some of which might inform the global community of science education.

This paper presents a revised learning progression for the energy concept and initial findings on diverse progressions among subgroups of sample students. The revised learning progression describes how students progress towards an understanding of the energy concept along two progress variables identified from previous studies--key ideas about energy and levels of conceptual development. To assess students understanding with respect to the revised learning progression, we created a specific instrument, the Energy Concept Progression Assessment (ECPA) based on previous work on assessing students' understanding of energy. After iteratively refining the instrument in two pilot studies, the ECPA was administered to a total of 4550 students (Grades 8-12) from schools in two districts in a major city in Mainland China. Rasch analysis was used to examine the validity of the revised learning progression and explore factors explaining different progressions. Our results confirm the validity of the four conceptual development levels. In addition, we found that although following a similar progression pattern, students' progression rate was significantly influenced by environmental factors such as school type. In the discussion of our findings, we address the non-linear and complex nature of students' progression in understanding energy. We conclude with illuminating our research's implication for curriculum design and energy teaching.

Pleistocene cave deposits usually provide ideal materials for the study of mammals. Karst caves in Chongzuo, Guangxi Zhuang Autonomous Region of south China are famous for numerous studies on their abundant mammalian fossils and most importantly, Homo sapiens. Unfortunately, the environmental backgrounds, e.g. vegetation and climate, that governed these faunas, are usually lacking because there is no appropriate proxy. In this work, we analysed the palynological assemblages from seven well-dated karst caves in Chongzuo. The ages of these seven caves (2.0–0.11 Ma) cover almost the entire Pleistocene. Though the number of pollen and spores is comparatively low, as expected, we managed to reconstruct the principle vegetation types. The results show that the individual vegetations were mainly warm temperate to subtropical evergreen and deciduous broad-leaved mixed forests. The present study provides important background environmental information on the Pleistocene faunas and Homo sapiens in Guangxi, south China. [ABSTRACT FROM AUTHOR]

China initiated a new round of science curriculum reform in 2017. Using the tripartite curriculum framework (including policy, programmatic, and classroom curriculum), we introduce and analyse China’s policy curriculum and programmatic curriculum for science in primary school and senior high school, and describe the potential problems hindering the translation of these curricula into the classroom curriculum. We first identify the multiple aims of different stakeholders in science education, some of which influence the science policy curriculum. Then, we present the major changes in how the programmatic curriculum meets the policy curriculum. However, due to extracurricular factors, the current science curriculum reform may not unfold as expected. We end with a discussion of the three major characteristics of the revision process of science curriculum standards in China, some of which might inform the global community of science education. [ABSTRACT FROM AUTHOR]

Abstract: Providing scientific explanations for natural phenomena is a fundamental aim of science; therefore, scientific explanation has been selected as one of the key practices in science education policy documents around the world. To further elaborate on existing educational frameworks of scientific explanation in K–12, we propose a learning progression of scientific explanation based on the Phenomenon‐Theory‐Data‐Reasoning (PTDR) framework. To examine the validation of the PTDR framework for scientific explanation and the learning progression based on it, we developed the Scientific Explanation Progression Assessment to investigate students’ performance (Grades 8–12 students, N = 4,554) on scientific explanations. A Rasch analysis and other statistical tests together indicated the validity of the PTDR framework for scientific explanation and the learning progression derived from this framework. We end with a discussion of the implications for future design of instruction and assessment. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 55: 299–317, 2018 [ABSTRACT FROM AUTHOR]

This paper presents a revised learning progression for the energy concept and initial findings on diverse progressions among subgroups of sample students. The revised learning progression describes how students progress towards an understanding of the energy concept along two progress variables identified from previous studies – key ideas about energy and levels of conceptual development. To assess students understanding with respect to the revised learning progression, we created a specific instrument, the Energy Concept Progression Assessment (ECPA) based on previous work on assessing students’ understanding of energy. After iteratively refining the instrument in two pilot studies, the ECPA was administered to a total of 4550 students (Grades 8–12) from schools in two districts in a major city in Mainland China. Rasch analysis was used to examine the validity of the revised learning progression and explore factors explaining different progressions. Our results confirm the validity of the four conceptual development levels. In addition, we found that although following a similar progression pattern, students’ progression rate was significantly influenced by environmental factors such as school type. In the discussion of our findings, we address the non-linear and complex nature of students’ progression in understanding energy. We conclude with illuminating our research's implication for curriculum design and energy teaching. [ABSTRACT FROM PUBLISHER]

Fossil blister pearls attached to the shells of an Anodonta mollusk from China, early Early Pleistocene, are reported here for the first time. The pearls were investigated in detail using a variety of methods. Micro-CT scanning of the fossil pearls was carried out to discover the inner structure and the pearl nucleus. Using CTAn software, changes in the gray levels of the biggest pearl, which reflect the changing density of the material, were investigated. The results provide us with some clues on how these pearls were formed. Sand grains, shell debris or material with a similar density could have stimulated the development of these pearls. X-ray diffraction analysis of one fossil pearl and the shell to which it was attached reveals that only aragonite exists in both samples. The internal structures of our fossil shells and pearls were investigated using a Scanning Electron Microscope. These investigations throw some light on pearl development in the past. [ABSTRACT FROM AUTHOR]

Late Devonian Minostrobus chaohuensis is one of the earliest monosporangiate-strobilate isoetaleans. Based on new material of this plant, the vegetative axis and microsporangiate strobilus are studied in detail, and the whole plant knowledge is summarized. The vegetative axis is isotomously branched. The stem is up to 55 mm in diameter with helically arranged leaf cushions. Stems and thick branches bear long fusiform leaf cushions and interareas with vertical linear ornamentations. A ligule pit, oblanceolate leaf scar, and vascular bundle scar appear on the leaf cushion. Distal axes have persistent lanceolate leaves and rhombic leaf bases. The microsporangiate strobilus is cylindrical in shape, possesses sporophyll with alate pedicel and long triangular lamina, uniseriate sporangial wall, subarchesporial pad inside the sporangium, and microspore with cingulum. Based on comparisons with other isoetaleans, the usage of the terms “leaf cushion” and “leaf base” is discussed, and Minostrobus chaohuensis is considered as a tree-like lycopsid. It suggests that arborescent isoetaleans with monosporangiate strobili had appeared and diversified in the Late Devonian. The multi-dichotomous branching system of Minostrobus provides new data on the evolution of growth architecture in rhizomorphic lycopsids. [ABSTRACT FROM AUTHOR]

Background: The current study investigated the effects of Piper longumine on radio-sensitization of human breast cancer MDA-MB-231 cells and underlying mechanisms., Materials and Methods: Human breast cancer MDA-MB-231 cells were cultured in vitro and those in logarithmic growth phase were selected for experiments divided into four groups: control, X-ray exposed, Piper longumine, and Piper longumine combined with X-rays. Conogenic assays were performed to determine the radio-sensitizing effects. Cell survival curves were fitted by single-hit multi-target model and then the survival fraction (SF), average lethal dose (D0), quasi-threshold dose (Dq) and sensitive enhancement ratio (SER) were calculated. Cell apoptosis was analyzed by flow cytometry (FCM).Western blot assays were employed for expression of apoptosis-related proteins (Bc1-2 and Bax) after treatment with Piper longumine and/or X-ray radiation. The intracellular reactive oxygen species (ROS) level was detected by FCM with a DCFH-DA probe., Results: The cloning formation capacity was decreased in the group of piperlongumine plus radiation, which displayed the values of SF2, D0, Dq significantly lower than those of radiation alone group and the sensitive enhancement ratio (SER) of D0 was1.22 and 1.29, respectively. The cell apoptosis rate was increased by the combination treatment of Piper longumine and radiation. Piper longumine increased the radiation-induced intracellular levels of ROS. Compared with the control group and individual group, the combination group demonstrated significantly decreased expression of Bcl-2 with increased Bax., Conclusions: Piper longumine at a non-cytotoxic concentration can enhance the radio-sensitivity of MDA- MB-231cells, which may be related to its regulation of apoptosis-related protein expression and the increase of intracellular ROS level, thus increasing radiation-induced apoptosis.