1,370 research outputs found

    Lessons Learned from Citizen Science in the Classroom. A Response to The Future of Citizen Science.

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    Mueller, Tippins, and Bryan’s contrast of the current limitations of science education with the potential virtues of citizen science provides an important theoretical perspective about the future of democratized science and K–12 education. However, the authors fail to adequately address the existing barriers and constraints to moving community-based science into the classroom. We contend that for these science partnerships to be successful, teachers, researchers, and other program designers must reexamine questions about traditional science education and citizen-science programs and attend to certain dimensions, including: framing these projects around the nature of science, creating a dialog with experts and allowing access to the primary literature, and fostering the ability of the public to critique information and evidence. We argue that the resource constraints of scientists, teachers, and students likely pose problems to moving true democratized science into the classroom

    Temporal and spatial variability of phytoplankton and mixotrophs in a temperate estuary

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    A significant proportion of phototrophic species are known to be mixotrophs: cells that obtain nutrients through a combination of photosynthesis and prey ingestion. Current methods to estimate mixotroph abundance in situ are known to be limited in their ability to help identify conditions that favor mixotrophs over strict autotrophs. For the first time, we combine microscopic analysis of phototrophic taxa with immunoprecipitated bromodeoxyuridine (BrdU)labeled DNA amplicon sequencing to identify and quantify active and putative mixotrophs at 2 locations in a microtidal temperate estuary. We analyze these data to examine spatial and temporal variability of phytoplankton and mixotrophs. Microscopy-based phototrophic diversity and abundances reveal expected seasonal patterns for our 2 stations, with the start of growth in winter and highest abundances in summer. Diatoms tend to dominate at the site with less stratification, while dinoflagellates and euglenids are usually more prominent at the stratified station. The BrdU-based mixotroph identifications are translated to the microscopy identification and abundances to estimate the proportion of mixotrophs (cells \u3e10 μm in size) at both sites. The average proportion of potential mixotrophs is higher at the station with higher stratification (51%) compared to the station with lower stratification (30%), and potential mixotrophs tend to be higher in summer, although we did not conduct BrdU experiments in any of the other seasons. Combining the identification of active mixotrophs through the uptake of BrdU-labeled bacteria with robust abundance measurements can expand our understanding of mixotrophs across systems

    On the magnetic structure of the solar transition region

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    We examine the hypothesis that ``cool loops'' dominate emission from solar transition region plasma below temperatures of 2×1052\times10^5K. We compare published VAULT images of H Lα\alpha, a lower transition region line, with near-contemporaneous magnetograms from Kitt Peak, obtained during the second flight (VAULT-2) on 14 June 2002. The measured surface fields and potential extrapolations suggest that there are too few short loops, and that Lα\alpha emission is associated with the base regions of longer, coronal loops. VAULT-2 data of network boundaries have an asymmetry on scales larger than supergranules, also indicating an association with long loops. We complement the Kitt Peak data with very sensitive vector polarimetric data from the Spectro-Polarimeter on board Hinode, to determine the influence of very small magnetic concentrations on our analysis. From these data two classes of behavior are found: within the cores of strong magnetic flux concentrations (>5×1018> 5\times10^{18} Mx) associated with active network and plage, small-scale mixed fields are absent and any short loops can connect just the peripheries of the flux to cell interiors. Core fields return to the surface via longer, most likely coronal, loops. In weaker concentrations, short loops can connect between concentrations and produce mixed fields within network boundaries as suggested by Dowdy and colleagues. The VAULT-2 data which we examined are associated with strong concentrations. We conclude that the cool loop model applies only to a small fraction of the VAULT-2 emission, but we cannot discount a significant role for cool loops in quieter regions. We suggest a physical picture for how network Lα\alpha emission may occur through the cross-field diffusion of neutral atoms from chromospheric into coronal plasma.Comment: Accepted by ApJ, 9 May 200

    Volcanological evolution of Pantelleria Island (Strait of Sicily) peralkaline volcano: a review

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    Pantelleria volcano has a particularly intriguing evolutionary history intimately related to the peralkaline composition of its explosively erupted magmas. Due to the stratigraphic complexity, studies over the last two decades have explored either only the pre-Green Tuff ignimbrite volcanism or the post-Green Tuff activity. We here focus on the whole evolutionary history, detailing the achievements since the first pioneering studies, in order to illustrate how the adoption and integration of progressively more accurate methods (40Ar/39Ar, paleomagnetism, petrography, and detailed field study) have provided many important independent answers to unresolved questions. We also discuss rheomorphism, a distinct feature at Pantelleria, at various scales and possible evidence for multiple, now hidden, caldera collapses. Although the evolutionary history of Pantelleria has shown that each ignimbrite event was followed by a period of less intense explosivity (as could be the present-day case), new geochronological and geochemical data may indicate a long-term waning of volcanic activity

    Modeling with a Conceptual representation: is it necessary? does it Work?

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    In response to recent educational imperatives in the United States, modeling and systems thinking have been identified as being critical for science learning. In this paper, we investigate models in the classroom from two important perspectives: (1) from the teacher perspective to understand how teachers perceive models and use models in the classroom and (2) from the students perspective to understand how student use model-based reasoning to represent their understanding in a classroom setting. Qualitative data collected from 19 teachers who attended a professional development workshop in the northeastern United States indicate that while teachers see the value in teaching to think with models (i.e., during inquiry practices), they tend to use models mostly as communication tools in the classroom. Quantitative data collected about the modeling practices of 42 middle school students who worked collaboratively in small groups (4–5 students) using a computer modeling program indicated that students tended to engage in more mechanistic and function-related thinking with time as they reasoned about a complex system. Furthermore, students had a typified trajectory of first adding and then next paring down ideas in their models. Implications for science education are discussed

    Modeling with a Conceptual representation: is it necessary? does it Work?

    Get PDF
    In response to recent educational imperatives in the United States, modeling and systems thinking have been identified as being critical for science learning. In this paper, we investigate models in the classroom from two important perspectives: (1) from the teacher perspective to understand how teachers perceive models and use models in the classroom and (2) from the students perspective to understand how student use model-based reasoning to represent their understanding in a classroom setting. Qualitative data collected from 19 teachers who attended a professional development workshop in the northeastern United States indicate that while teachers see the value in teaching to think with models (i.e., during inquiry practices), they tend to use models mostly as communication tools in the classroom. Quantitative data collected about the modeling practices of 42 middle school students who worked collaboratively in small groups (4–5 students) using a computer modeling program indicated that students tended to engage in more mechanistic and function-related thinking with time as they reasoned about a complex system. Furthermore, students had a typified trajectory of first adding and then next paring down ideas in their models. Implications for science education are discussed

    Restarting the conversation: challenges at the interface between ecology and society

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    8 páginas, 3 figuras, 2 tablas. -- Copyright by the Ecological Society of AmericaThe exchange of information between researchers, resource managers, decision makers, and the general public has long been recognized as a critical need in environmental science. We examine the challenges in using ecological knowledge to inform society and to change societal actions, and identify a set of options and strategies to enhance this exchange. Our objectives are to provide background information on societal knowledge and interest in science and environmental issues, to describe how different components of society obtain information and develop their interests and values, and to present a framework for evaluating and improving communication between science and society. Our analysis strongly suggests that the interface between science and society can only be improved with renewed dedication to public outreach and a wholesale reconsideration of the way that scientists communicate with society. Ecologists need to adopt new models of engagement with their audiences, frame their results in ways that are more meaningful to these audiences, and use new communication tools, capable of reaching large and diverse target groups.Este artículo está basado en unas presentaciones orales realizadas en 2009 Cary Conference. The Cary Conference fue financiada por la National Science Foundation (subvención #DEB-0840224 y #0949558), el US Department of Agriculture (USDA) Forest Service (subvención #09-DG-11132650-083), el US Environmental Protection Agency (subvención #EP09H000638), y el USDA Agriculture and Food Research Initiative Program.Peer reviewe

    Non-amidated and amidated members of the C-type allatostatin (AST-C) family are differentially distributed in the stomatogastric nervous system of the American lobster, Homarus americanus

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    The crustacean stomatogastric nervous system (STNS) is a well-known model for investigating neuropeptidergic control of rhythmic behavior. Among the peptides known to modulate the STNS are the C-type allatostatins (AST-Cs). In the lobster, Homarus americanus, three AST-Cs are known. Two of these, pQIRYHQCYFNPISCF (AST-C I) and GNGDGRLYWRCYFNAVSCF (AST-C III), have non-amidated C-termini, while the third, SYWKQCAFNAVSCFamide (AST-C II), is C-terminally amidated. Here, antibodies were generated against one of the non-amidated peptides (AST-C I) and against the amidated isoform (AST-C II). Specificity tests show that the AST-C I antibody cross-reacts with both AST-C I and AST-C III, but not AST-C II; the AST-C II antibody does not cross-react with either non-amidated peptide. Wholemount immunohistochemistry shows that both subclasses (non-amidated and amidated) of AST-C are distributed throughout the lobster STNS. Specifically, the antibody that cross-reacts with the two non-amidated peptides labels neuropil in the CoGs and the stomatogastric ganglion (STG), axons in the superior esophageal (son) and stomatogastric (stn) nerves, and ~ 14 somata in each commissural ganglion (CoG). The AST-C II-specific antibody labels neuropil in the CoGs, STG and at the junction of the sons and stn, axons in the sons and stn, ~ 42 somata in each CoG, and two somata in the STG. Double immunolabeling shows that, except for one soma in each CoG, the non-amidated and amidated peptides are present in distinct sets of neuronal profiles. The differential distributions of the two AST-C subclasses suggest that the two peptide groups are likely to serve different modulatory roles in the lobster STNS
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