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The performance of multi-type environmental credit trading markets: Lab experiment evidence
No full textWe experimentally compare the performance of two multi-type environmental credit trading markets. The first trading market is called the multiple market (MM) institution, which allows the providers to sell jointly produced credits of all types. The second trading market is called the single market (SM) institution, where the providers of jointly produced credits can only choose one type of credit to sell. We investigate several key indicators, including the trading price, quantity, and net social benefit, to compare the performance of the SM and MM institutions. We find that the trading prices are significantly lower in MM compared to SM, indicating that MM potentially benefits the credit buyers. We also find that SM leads to more credit productions. Since not all credits can be traded in SM, the increase in the production cost outweighs the increase in the total social benefit. As a result, the net social benefit is lower in SM compared to MM. We expand the literature by firstly designing a market platform for multi-type credit trading and then assessing their performance with lab experiment evidence
Quantification of microplastics in sediments from Narragansett Bay, Rhode Island USA using a novel isolation and extraction method
No full textMicroplastics are small plastic particles found ubiquitously in marine environments. In this study, a hybridized method was developed for the extraction of microplastics (45–1000 μm) from sediments using sodium bromide solution for density separation. Method development was tested using spiked microplastics as internal standards. The method was then used to extract microplastics from sediments in Narragansett Bay, Rhode Island, USA. Suspect microplastics were analyzed with Raman spectroscopy. Microplastic abundance ranged from 40 particles/100 g sediment to 4.6 million particles/100 g sediment (wet weight). Cellulose acetate fibers were the most abundant microplastic. These results are some of the first data for microplastics in Rhode Island sediments
Defining a Flexible Notion of “Good” STEM Writing Across Contexts: Lessons Learned From a Cross-Institutional Conversation
Get PDFWe respond to a surging interest in science communication training for graduate scientists by advocating for a focus on rhetorically informed approaches to STEM writing and its assessment. We argue that STEM communication initiatives would benefit by shifting from a strategic focus on products to a flexible understanding of writing as a practice worthy of attention and study. To do that, we use our experience across two universities and two distinct programmatic contexts to train STEM graduate students in writing and communication. We draw from cross-disciplinary conversations to identify four facets of “good” STEM writing: (1) connecting to the big picture; (2) explaining science; (3) adhering to genre conventions; and (4) choosing context-appropriate language. We then describe our ongoing conversations across contexts to develop and implement flexible rubrics that capture and foster conversations around “good” writing. In doing so, we argue for a notion of writing rubrics as boundary objects, capable of fostering cross-disciplinary, integrative conversations and collaborations that strengthen student writing, shift STEM students toward a rhetorically informed sense of “good” writing, and offer that kinds of assessment data that make for persuasive evidence of the power of writing-centric approaches for STEM administrators and funders
The Future of Invasion Science Needs Physiology
No full textIncorporating physiology into models of population dynamics will improve our understanding of how and why invasions succeed and cause ecological impacts, whereas others fail or remain innocuous. Targeting both organismal physiologists and invasion scientists, we detail how physiological processes affect every invasion stage, for both plants and animals, and how physiological data can be better used for studying the spatial dynamics and ecological effects of invasive species. We suggest six steps to quantify the physiological functions related to demography of nonnative species: justifying physiological traits of interest, determining ecologically appropriate time frames, identifying relevant abiotic variables, designing experimental treatments that capture covariation between abiotic variables, measuring physiological responses to these abiotic variables, and fitting statistical models to the data. We also provide brief guidance on approaches to modeling invasions. Finally, we emphasize the benefits of integrating research between communities of physiologists and invasion scientists
Two decades of data reveal that Biological Invasions needs to increase participation beyond North America, Europe, and Australasia
No full textMost published papers in ecology come from a handful of countries, and invasion science as an ecological subdiscipline is no exception. Based on the country of corresponding authors, we analyzed patterns in submissions, reviews, and publications in the journal Biological Invasions from its first issue in 1999 to 2020. Regionally, North America, Europe, and Australasia submitted and published the most articles during this period and supplied most reviewers and journal editors. As a country, the USA stands out in terms of papers published and reviewers involved in the process. The dominance of published articles from USA-based scientists declined through time, but such articles still constitute one-third of all articles in recent years. However, as biological invasions are a worldwide phenomenon acting on local to global scales, research from all regions of the world is needed to better understand and manage invasions. By tracking and reporting the trends in the countries of origin of the journal’s authors and reviewers, and by encouraging submissions from more countries, we hope that geographical differences will decrease and that a more global understanding of biological invasions will emerge
Classifying and Georeferencing Indoor Point Clouds with ArcGIS
Get PDFThis study aimed to develop and apply a manual procedure for classifying and georeferencing indoor point clouds that we created using Paracosm’s PX-80 handheld three-dimensional laser scanner. We collected data for 11 buildings in Connecticut, USA and focused on classifying features-of-interest to public safety personnel (i.e., doors, windows, fire alarms, etc.). ArcGIS Desktop was used to manually digitize features that were easily identified in the point cloud and Paracosm’s Retrace was used to digitize small features for which imagery was needed for identification. We developed several tools in Python to facilitate point cloud classification and georeferencing. The procedure allowed accurate mapping of features as small as a sprinkler head. Point cloud classification and georeferencing for a 14 000 m2 building took 20–40 hours, depending on building characteristics and the types of features mapped. The methods can be applied in mapping a wide variety of features in indoor or outdoor environments