Sediment Content in Antarctic Iceberg Fragments Sufficient to Sink the Ice

Iceberg fragments recovered from the sea floor near Swift Glacier, Antarctica, contained sufficient sediment to sink the ice. Sediment concentrations in the samples would have caused them to settle at 0.13 to 0.35 m/s through the water column. Impact with the sea floor would significantly turbate soft sediments. Unlike sediment dumped from icebergs, the stratigraphy of the frozen sediments created by glacial processes may be preserved in the marine sedimentary record after melting of the ice. Negatively buoyant berg fragments may be common in polar regions, and when driven by currents may scour the sea floor up and down slopes unlike floating ice.Des fragments d’icebergs recueillis sur le fond océanique, près du glacier de Swift, en Antarctique, contenaient suffisamment de sédiments pour couler à une vitesse de 0,13 à 0,35 m/s. La collision de tels fragments avec le plancher marin entraînerait un brassage important des sédiments mous. Au contraire de celle de sédiments délestés par les icebergs, la stratigraphie de ces sédiments gelés résultant de processus glaciaires peut être préservée au sein des dépôts marins après la fonte des fragments de glace dans lesquels ils sont emprisonnés. Ces fragments, dont la densité est supérieure à celle de l’eau, pourraient être communs dans les régions polaires et causer, sous l’action des courants, un labourage ascendant et descendant des pentes des fonds marins, contrairement aux glaces flottantes

Improving undergraduate STEM education: The efficacy of discipline-based professional development

We sought to determine whether instructional practices used by undergraduate faculty in the geosciences have shifted from traditional teacher-centered lecture toward student-engaged teaching practices and to evaluate whether the national professional development program On the Cutting Edge (hereinafter Cutting Edge) has been a contributing factor in this change. We surveyed geoscience faculty across the United States in 2004, 2009, and 2012 and asked about teaching practices as well as levels of engagement in education research, scientific research, and professional development related to teaching. We tested these self-reported survey results with direct observations of teaching using the Reformed Teaching Observation Protocol, and we conducted interviews to understand what aspects of Cutting Edge have supported change. Survey data show that teaching strategies involving active learning have become more common, that these practices are concentrated in faculty who invest in learning about teaching, and that faculty investment in learning about teaching has increased. Regression analysis shows that, after controlling for other key influences, faculty who have participated in Cutting Edge programs and who regularly use resources on the Cutting Edge website are statistically more likely to use active learning teaching strategies. Cutting Edge participants also report that learning about teaching, the availability of teaching resources, and interactions with peers have supported changes in their teaching practice. Our data suggest that even one-time participation in a workshop with peers can lead to improved teaching by supporting a combination of affective and cognitive learning outcomes

Slate Literary Magazine, 2012-2013

Trinity College\u27s Literary Magazine - student works.https://digitalrepository.trincoll.edu/slate/1000/thumbnail.jp

Regional Endothermy in a Coral Reef Fish?

Although a few pelagic species exhibit regional endothermy, most fish are regarded as ectotherms. However, we document significant regional endothermy in a benthic reef fish. Individual steephead parrotfish, Chlorurus microrhinos (Labridae, formerly Scaridae) were tagged and their internal temperatures were monitored for a 24 h period using active acoustic telemetry. At night, on the reef, C. microrhinos were found to maintain a consistent average peritoneal cavity temperature 0.16±0.005°C (SE) warmer than ambient. Diurnal internal temperatures were highly variable for individuals monitored on the reef, while in tank-based trials, peritoneal cavity temperatures tracked environmental temperatures. The mechanisms responsible for a departure of the peritoneal cavity temperature from environmental temperature occurred in C. microrhinos are not yet understood. However, the diet and behavior of the species suggests that heat in the peritoneal cavity may result primarily from endogenous thermogenesis coupled with physiological heat retention mechanisms. The presence of limited endothermy in C. microrhinos indicates that a degree of uncertainty may exist in the manner that reef fish respond to their thermal environment. At the very least, they do not always appear to respond to environmental temperatures as neutral thermal vessels and do display limited, but significant, visceral warming

Diel surface temperature range scales with lake size

Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored

Synthesizing the scientific evidence to inform the development of the post-2020 Global Framework on Biodiversity

Fil: Díaz, Sandra. Universidad Nacional de Córdoba; Argentina.Fil: Broadgate, Wendy. Future Earth; Suecia.Fil: Declerck, Fabrice. Bioversity International; Italia.Fil: Dobrota, Susanna. Future Earth; Suecia.Fil: Krug, Cornelia. bioDISCOVERY; Suecia.Fil: Moersberg, Hannah. Future Earth; Francia.Fil: Obura, David. Coastal Oceans Research and Development – Indian Ocean; Kenya.Fil: Spehn, Eva. Forum Biodiversity; Suiza.Fil: Tewksbury, Joshua. Future Earth; Estados Unidos.Fil: Verburg, Peter. Vrije Universiteit Amsterdam; Países Bajos.Fil: Zafra Calvo, Noelia. Future Earth; Suecia.Fil: Bellon, Mauricio. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad; México.Fil: Burgess, Neil. United Nations Environment Programme World Conservation Monitoring Centre; Reino Unido.Fil: Cariño, Joji. Forest Peoples Programme; Reino Unido.Fil: Castañeda Alvarez, Nora. Global Crop Diversity Trust; Alemania.Fil: Cavender-Bares, Jeannine. University of Minnesota; Estados Unidos.Fil: Chaplin Kramer, Rebecca. Stanford University; Estados Unidos.Fil: De Meester, Luc. Katholieke Universiteit Leuven; Bélgica.Fil: Dulloo, Ehsan. Consultative Group for International Agricultural Research; Francia.Fil: Fernández-Palacios, José María. Universidad de La Laguna; España.Fil: Garibaldi, Lucas A. Universidad Nacional de Río Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; Argentina.Fil: Garibaldi, Lucas A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; Argentina.Fil: Hill, Samantha. United Nations Environment Programme World Conservation Monitoring Centre; Reino Unido.Fil: Isbell, Forest. University of Minnesota; Estados Unidos.Fil: Leadley, Paul. Université Paris-Saclay; Francia.Fil: Liu, Jianguo. Michigan State University; Estados Unidos.Fil: Mace, Georgina M. University College London; Reino Unido.Fil: Maron, Martine. The University of Queensland; Australia.Fil: Martín-López, Berta. Leuphana University Lüneburg; Alemania.Fil: McGowan, Philip. University of Newcastle; Australia.Fil: Pereira, Henrique. German Centre for Integrative Biodiversity Research; Alemania.Fil: Purvis, Andy. Imperial College London. Grand Challenges in Ecosystems and the Environment; Reino Unido.Fil: Reyes-García, Victoria. Universidad Autónoma de Barcelona; España.Fil: Rocha, Juan. Future Earth; Suecia.Fil: Rondinini, Carlo. Sapienza-Università di Roma; Italia.Fil: Shannon, Lynne. University of Cape Town; Sudáfrica.Fil: Shaw, Rebecca. World Wildlife Fund; Estados Unidos.Fil: Shin, Yunne Jai. University of Cape Town. Marine Research Institute. Department of Biological Sciences; Sudáfrica.Fil: Snelgrove, Paul. Memorial University of Newfoundland; Canadá.Fil: Strassburg, Bernardo. International Institute for Sustainability; Brasil.Fil: Subramanian, Suneetha.United Nations University; Japón.Fil: Visconti, Piero. International Institute for Applied Systems Analysis; Austria.Fil: Watson, James. Wildlife Conservation Society; Estados Unidos.Fil: Zanne, Amy. The George Washington University; Estados Unidos.Fil: Bruford, Michael. Cardiff University; Gales.Fil: Colli, Licia. Università Cattolica del Sacro Cuore; Italia.Fil: Azeredo de Dornelas, Maria. University of St Andrews; Escocia.Fil: Bascompte, Jordi. Universität Zürich; Suiza.Fil: Forest, Felix. Royal Botanic Gardens; Reino Unido.Fil: Hoban, Sean. The Morton Arboretum; Estados Unidos.Fil: Jones, Sarah. Consultative Group for International Agricultural Research; Francia.Fil: Jordano, Pedro. Consejo Superior de Investigaciones Científicas; España.Fil: Kassen, Rees. University of Ottawa; Canadá.Fil: Khoury, Colin. Consultative Group for International Agricultural Research; Francia.Fil: Laikre, Linda. Stockholms Universitet; Suecia.Fil: Maxted, Nigel. University of Birmingham; Reino Unido.Fil: Miloslavich, Patricia. Universidad Simón Bolívar; Venezuela.Fil: Moreno Mateos, David. Basque Centre for Climate Change; España.Fil: Ogden, Rob. The University of Edinburgh; Reino Unido.Fil: Segelbacher, Gernot. Albert-Ludwigs-Universität Freiburg; Alemania.Fil: Souffreau, Caroline. Katholieke Universiteit Leuven; Bélgica.Fil: Svenning, Jens Christian. Aarhus University; Dinamarca.Fil: Vázquez, Ella. Universidad Nacional Autónoma de México; México.This report is the result of a meeting which aimed to offer scientific guidance to the development under the Convention on Biological Diversity (CBD) of the post-2020 Global Biodiversity Framework focussing on its contribution to the 2030 Mission and 2050 Vision. We provide a synthesis of the scientific and technical justification, evidence base and feasibility for outcome-oriented goals on nature and its contributions to people, including biodiversity at different levels from genes to biomes. The report is structured to respond to the Zero Draft of the post-2020 Global Biodiversity Framework

Swimming with Predators and Pesticides: How Environmental Stressors Affect the Thermal Physiology of Tadpoles

To forecast biological responses to changing environments, we need to understand how a species’s physiology varies through space and time and assess how changes in physiological function due to environmental changes may interact with phenotypic changes caused by other types of environmental variation. Amphibian larvae are well known for expressing environmentally induced phenotypes, but relatively little is known about how these responses might interact with changing temperatures and their thermal physiology. To address this question, we studied the thermal physiology of grey treefrog tadpoles (Hyla versicolor) by determining whether exposures to predator cues and an herbicide (Roundup) can alter their critical maximum temperature (CTmax) and their swimming speed across a range of temperatures, which provides estimates of optimal temperature (Topt) for swimming speed and the shape of the thermal performance curve (TPC). We discovered that predator cues induced a 0.4uC higher CTmax value, whereas the herbicide had no effect. Tadpoles exposed to predator cues or the herbicide swam faster than control tadpoles and the increase in burst speed was higher near Topt. In regard to the shape of the TPC, exposure to predator cues increased Topt by 1.5uC, while exposure to the herbicide marginally lowered Topt by 0.4uC. Combining predator cues and the herbicide produced an intermediate Topt that was 0.5uC higher than the control. To our knowledge this is the first study to demonstrate a predator altering the thermal physiology of amphibian larvae (prey) by increasing CTmax, increasing the optimum temperature, and producing changes in the thermal performance curves. Furthermore, these plastic responses of CTmax and TPC to different inducing environments should be considered when forecasting biological responses to global warming.Peer reviewe

Linking behaviour and climate change in intertidal ectotherms: insights from littorinid snails

A key element missing from many predictive models of the impacts of climate change on intertidal ectotherms is the role of individual behaviour. In this synthesis, using littorinid snails as a case study, we show how thermoregulatory behaviours may buffer changes in environmental temperatures. These behaviours include either a flight response, to escape the most extreme conditions and utilize warmer or cooler environments; or a fight response, where individuals modify their own environments to minimize thermal extremes. A conceptual model, generated from studies of littorinid snails, shows that various flight and fight thermoregulatory behaviours may allow an individual to widen its thermal safety margin (TSM) under warming or cooling environmental conditions and hence increase species’ resilience to climate change. Thermoregulatory behaviours may also buffer sublethal fitness impacts associated with thermal stresses. Through this synthesis, we emphasise that future studies need to consider not only animals' physiological limits but also their capacities to buffer the impact of climate change through behavioural responses. Current generalizations, made largely on physiological limits of species, often neglect the buffering effects of behaviour and may, therefore, provide an over-estimation of vulnerability, and consequently poor prediction of the potential impacts of climate change on intertidal ectotherms