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1.
Solar eclipses occur several times a year, but most people will be lucky if they see one total solar eclipse in their lifetime. There are two upcoming total solar eclipses that can be seen from different parts of the United States (August 21, 2017 and April 8, 2024), and they provide teachers with an amazing opportunity to engage students with a remarkable astronomical event. We summarize the science behind eclipses and describe an inexpensive activity for students from third grade up through middle school that will let them use models to see the differences between total, annular, and partial solar eclipses. The activity lets students explore why, during a solar eclipse, people in different areas will see different types of eclipses. The activity can be used as a way to get students excited about astronomy and the upcoming eclipses. We also give ideas for ways that teachers can engage their students during the eclipses.  相似文献   

2.
Undergraduate biology majors require biological literacy about the critical and dynamic relationships between plants and ecosystems and the effect human-made processes have on these systems. To support students in understanding systems relationships, we redesigned an undergraduate botany course using an ecological framework and embedded systems modelling to support students in understanding the criticality of plant processes to the global carbon cycle. The class meetings included lectures, opportunities to develop systems models identifying the relationships between plant processes and other systems, reflections on their systems understanding and open-floor discussions about assigned primary and secondary readings that explored the relationships between plant systems, abiotic and biotic processes and global carbon cycling in their systems models. We used the systems models students developed at the beginning and end of the course to examine how their systems understanding grew. Our results suggest that at the beginning of term, students’ ideas about plants were egocentric identifying the purpose of plants was to support human life and they did not consider relationships between plants and global carbon systems. By the end of the term, their models and reflections identified elements of a systems perspective and the students considered human impact on this delicate balance.  相似文献   

3.
This study investigated beliefs about climate change among Swedish secondary school students at the end of their K-12 education. An embedded mixed method approach was used to analyse 51 secondary school students’ written responses to two questions: (1) What implies climate change? (2) What affects climate? A quantitative analysis of the responses revealed that ‘Earth’, ‘human’ and ‘greenhouse effect’ were frequent topics regarding the first question, and ‘pollution’, ‘atmosphere’ and ‘Earth’ were frequent regarding the second. A qualitative analysis, based on a ‘conceptual elements’ framework, focused on three elements within responses: atmosphere (causes and/or consequences), Earth (causes and consequences) and living beings (humans and/or animals and their impacts on climate change). It revealed a predominantly general or societal, rather than individual, perspective underlying students’ responses to the second question. The ability to connect general/societal issues with individual issues relating to climate change could prompt students to reflect on the contributions of individuals towards climate change mitigation, thereby constituting a basis for decision-making to promote a sustainable environment. Although the students did not discuss climate changes from an individual perspective, their statements revealed their understanding of climate change as a system comprising various components affecting the overall situation. They also revealed an understanding of the difference between weather and climate.  相似文献   

4.
The ocean is a major influence on weather and climate. With this set of lessons, middle school Earth systems science teachers can help their students build an understanding of how large bodies of water can serve as a heat source or sink at different times and how proximity to water moderates climate along the coast. The activity's combination of laboratory investigation, map study, and graphing applies different learning styles and provides practice in important science processes. The activities are adapted from Earth Systems Education Activities for Great Lakes Schools: Great Lakes Climate and Water Movement (V. J. Mayer et al. 1996).  相似文献   

5.
Understanding the concept of electromagnetic radiation (EMR) and its interaction with matter (absorption, reflection, and transmission) can be difficult for students in seventh and eighth grade physical science classes. This inquiry-based activity (IBA) is aimed at improving their understanding of these concepts by exploring the interaction of EMR with leaves of different plant species or health conditions. Incorporating at least two different types of leaves from the local environment and measuring their interaction with EMR peaks student interest in this activity. After completing this IBA, students will see how objects interact in different regions of the electromagnetic spectrum and gain a better understanding of phenomena such as reflection and absorption. Further, this IBA can help them understand how human eyes perceive different colors. This activity can be expanded by a biology teacher to include a discussion about leaf pigments and how their interaction with EMR determines the colors of leaves. Concepts covered in this IBA can be related to remote sensing science and how sensors on board satellites collect Earth Observation data.  相似文献   

6.
A mechanistic understanding of microbial assimilation of soil organic carbon is important to improve Earth system models’ ability to simulate carbon‐climate feedbacks. A simple modelling framework was developed to investigate how substrate quality and environmental controls over microbial activity regulate microbial assimilation of soil organic carbon and on the size of the microbial biomass. Substrate quality has a positive effect on microbial assimilation of soil organic carbon: higher substrate quality leads to higher ratio of microbial carbon to soil organic carbon. Microbial biomass carbon peaks and then declines as cumulative activity increases. The simulated ratios of soil microbial biomass to soil organic carbon are reasonably consistent with a recently compiled global data set at the biome level. The modelling framework developed in this study offers a simple approach to incorporate microbial contributions to the carbon cycling into Earth system models to simulate carbon‐climate feedbacks and explain global patterns of microbial biomass.  相似文献   

7.
When teaching and learning about alveolar ventilation with our class of 300 first-year medical students, we use four simple, inexpensive "models." The models, which encourage research-oriented learning and help our students to understand complex ideas, are distributed to the students before class. The students anticipate something new every day, and the models provide elements of surprise and physical examples and are designed to help students to understand 1) cohesive forces of the intrapleural space, 2) chest wall and lung dynamics, 3) alveolar volumes, and 4) regional differences in ventilation. Students are drawn into discussion by the power of learning that is associated with manipulating and thinking about objects. Specifically, the models encourage thinking about complex interactions, and the students appreciate manipulating objects and actually understanding how they work. Using models also allows us to show students how we think as well as what we know. Finally, students enjoy taking the models home to demonstrate to friends and family "how the body works" as well as use the models as future study aids.  相似文献   

8.
Global change encompasses many co-occurring anthropogenic drivers, which can act synergistically or antagonistically on ecological systems. Predicting how different global change drivers simultaneously contribute to observed biodiversity change is a key challenge for ecology and conservation. However, we lack the mechanistic understanding of how multiple global change drivers influence the vital rates of multiple interacting species. We propose that reaction norms, the relationships between a driver and vital rates like growth, mortality, and consumption, provide insights to the underlying mechanisms of community responses to multiple drivers. Understanding how multiple drivers interact to affect demographic rates using a reaction-norm perspective can improve our ability to make predictions of interactions at higher levels of organization—that is, community and food web. Building on the framework of consumer–resource interactions and widely studied thermal performance curves, we illustrate how joint driver impacts can be scaled up from the population to the community level. A simple proof-of-concept model demonstrates how reaction norms of vital rates predict the prevalence of driver interactions at the community level. A literature search suggests that our proposed approach is not yet used in multiple driver research. We outline how realistic response surfaces (i.e., multidimensional reaction norms) can be inferred by parametric and nonparametric approaches. Response surfaces have the potential to strengthen our understanding of how multiple drivers affect communities as well as improve our ability to predict when interactive effects emerge, two of the major challenges of ecology today.  相似文献   

9.
Self-generated analogical models have emerged recently as alternatives to teacher-supplied analogies and seem to have good potential to promote deep learning and scientific thinking. However, studies of the ways and contexts in which students generate these models are still too limited to allow a fuller appraisal of these models’ effectiveness in enhancing conceptual learning in science. This study explores how biology students aged 15–17 generated physical concrete models to represent their understanding of the respiration pathway after learning about it through a conventional flow diagram model. The analogies portrayed in students’ self-generated models provide teachers with a supplementary channel to explore students’ conceptual understandings of this complicated topic and allow students to reflect on ways in which the abstract pathway portrayed in textbooks actually makes sense to them.  相似文献   

10.
The third party     
Abstract. Spatial and temporal variation in interactions among plants, other species and the abiotic environment create context‐dependency in vegetation pattern. We argue that we can enhance understanding of context‐dependency by being more explicit about the kinds of direct interactions that occur among more than two living and non‐living entities (i.e., third through nth parties) and formalizing how their combinations create context‐dependency using simple conceptual models. This general approach can be translated into field studies of context‐dependency in communities by combining: progressive sampling of local variation in vegetation pattern that encompasses variation in combinations of direct interactions; spatial and temporal measures of these direct interactions; locally parameterized versions of the conceptual models; and appropriately scaled experiments.  相似文献   

11.
Ecology has expanded from its traditional focus on organisms to include studies of the Earth as an integrated ecosystem. Aided by satellite technologies and computer models of the climate of the Earth, global change ecology now records basic parameters of our planet, including its net primary productivity, biogeochemical cycling and effects of humans on it. As I discuss here, this new perspective shows us what must be done to transform human behaviors to enable the persistence of life on Earth under human stewardship.  相似文献   

12.
Of all ecosystems, freshwaters support the most dynamic and highly concentrated biodiversity on Earth. These attributes of freshwater biodiversity along with increasing demand for water mean that these systems serve as significant models to understand drivers of global biodiversity change. Freshwater biodiversity changes are often attributed to hydrological alteration by water‐resource development and climate change owing to the role of the hydrological regime of rivers, wetlands and floodplains affecting patterns of biodiversity. However, a major gap remains in conceptualising how the hydrological regime determines patterns in biodiversity's multiple spatial components and facets (taxonomic, functional and phylogenetic). We synthesised primary evidence of freshwater biodiversity responses to natural hydrological regimes to determine how distinct ecohydrological mechanisms affect freshwater biodiversity at local, landscape and regional spatial scales. Hydrological connectivity influences local and landscape biodiversity, yet responses vary depending on spatial scale. Biodiversity at local scales is generally positively associated with increasing connectivity whereas landscape‐scale biodiversity is greater with increasing fragmentation among locations. The effects of hydrological disturbance on freshwater biodiversity are variable at separate spatial scales and depend on disturbance frequency and history and organism characteristics. The role of hydrology in determining habitat for freshwater biodiversity also depends on spatial scaling. At local scales, persistence, stability and size of habitat each contribute to patterns of freshwater biodiversity yet the responses are variable across the organism groups that constitute overall freshwater biodiversity. We present a conceptual model to unite the effects of different ecohydrological mechanisms on freshwater biodiversity across spatial scales, and develop four principles for applying a multi‐scaled understanding of freshwater biodiversity responses to hydrological regimes. The protection and restoration of freshwater biodiversity is both a fundamental justification and a central goal of environmental water allocation worldwide. Clearer integration of concepts of spatial scaling in the context of understanding impacts of hydrological regimes on biodiversity will increase uptake of evidence into environmental flow implementation, identify suitable biodiversity targets responsive to hydrological change or restoration, and identify and manage risks of environmental flows contributing to biodiversity decline.  相似文献   

13.
Evaluating changes in land cover and their importance for global change   总被引:2,自引:0,他引:2  
During recent years, much progress has been made in integrating traditional natural science disciplines and in the developmnet of multidisciplinary models. This is crucial for an increased understanding of the dynamics of the Earth system. The domination of human activities in altering these dynamics is still increasing. However, few research projects have focused directly on understanding the motives for such intensification. It has only recently been acknowledged that improved understanding of human driving forces of global change is required to enable meaningful projections of plausible future states of the Earth system.  相似文献   

14.
A case study about carbon monoxide poisoning was used help students gain a greater understanding of the physiology of oxygen transport by the blood. A review of student answers to the case questions showed that students can use the oxygen-hemoglobin dissociation curve to make meaningful determinations of oxygen uptake and delivery. However, the fact that many students had difficulty locating the effect of carbon monoxide poisoning in the process of external respiration suggests that these students have not built a robust model of how oxygen distributes itself between the plasma and hemoglobin. This suggests that more determined emphasis on how oxygen enters the blood and how it is partitioned between hemoglobin and the plasma would help students develop more accurate mental models of how oxygen moves from the lungs to the tissues.  相似文献   

15.
The search for life on other planets usually makes the assumption that where there is a habitat, it will contain life. On the present-day Earth, uninhabited habitats (or vacant habitats) are rare, but might occur, for example, in subsurface oils or impact craters that have been thermally sterilized in the past. Beyond Earth, vacant habitats might similarly exist on inhabited planets or on uninhabited planets, for example on a habitable planet where life never originated. The hypothesis that vacant habitats are abundant in the Universe is testable by studying other planets. In this review, I discuss how the study of vacant habitats might ultimately inform an understanding of how life has influenced geochemical conditions on Earth.  相似文献   

16.
Symbiosis, the intimate association between two or more organisms, is a fundamental component of biological systems. Our ability to understand the processes involved in the establishment and function of Symbiosis has critical consequences for the health of humans and the world we live in. For example, a deeper understanding of how legumes and insects have harnessed the nitrogen-fixing capacity of microbes can pave the way toward novel strategies to decrease fertilizer use. Also, using insect models to elucidate links between diet, gut microbiota, and toxin sensitivity not only has implications for biological control strategies, but also will lend insights into similar links in the human gut ecosystem. These types of ideas were presented and discussed at the 6th International Symbiosis Society Congress held in Madison, Wisconsin August, 2009. Over 300 participants from 20 countries attended the 7-day event, which featured cutting-edge symbiosis research from many different perspectives and disciplines. The conference was organized thematically, with oral sessions focused on Evolution, Ecology, Metabolism, the Host-Microbe Interface, Threats to Earth Systems, Symbiosis Models and the Human Microbiome, Viruses and Organelles, and Symbiosis Education. World-renowned scientists, post-doctoral fellows, and students were given the opportunity to describe their most recent discoveries. Session chairs provided overviews of their programs which highlight how the comparative analysis of different systems reveal common trends underlying symbiotic associations, what tools and theory are being developed that may be applied more broadly in symbiosis research, how symbiosis research contributing solutions to global issues such as emerging antibiotic resistance, a need for alternative energy sources, the pursuit of sustainable agriculture and natural resources, and how symbiotic systems are ideal for educating people about the fascinating natural world around us. The following paragraphs provide an overview of the research and discussions that took place during the congress.  相似文献   

17.
The developments in biochemistry and molecular biology over the past 30 years have produced an impressive parts list of cellular components. It has become increasingly clear that we need to understand how components come together to form systems. One area where this approach has been growing is cell signalling research. Here, instead of focusing on individual or small groups of signalling proteins, researchers are now using a more holistic perspective. This approach attempts to view how many components are working together in concert to process information and to orchestrate cellular phenotypic changes. Additionally, the advancements in experimental techniques to measure and visualize many cellular components at once gradually grow in diversity and accuracy. The multivariate data, produced by experiments, introduce new and exciting challenges for computational biologists, who develop models of cellular systems made up of interacting cellular components. The integration of high-throughput experimental results and information from legacy literature is expected to produce computational models that would rapidly enhance our understanding of the detail workings of mammalian cells.  相似文献   

18.
Short, cost-effective teaching activities are a useful way of providing an integrated view on biological processes. Here we describe a brief, hands-on workshop that allows pre-university students to explore their understanding of a neurological pathway from its chemical bases to phenotype. The workshop effectively introduces the students to data collection and analysis in an enjoyable way and at an appropriate level, determined by an end of session feedback survey. The design of the workshop can be adapted and scaled to generate diverse sessions such as university teaching practicals or summer school training workshops.  相似文献   

19.
张宇  肖湘 《生命科学》2012,(9):986-990
深海是全球最大的独立生态系统,其中蕴涵着丰富并且独特的微生物资源有待我们开发。对深海微生物及其所处生态系统的研究将提升我们对地球早期环境及其变化过程的认识,为研究生命起源,甚至探索域外生命或其他潜在生命形式提供新的线索。对深海微生物研究开发的历史和进展进行了概述,并对这一研究领域的前沿及影响进行了讨论。  相似文献   

20.
Allostery and cooperativity revisited   总被引:1,自引:0,他引:1  
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