117 research outputs found

    Effects of Lake Erie Habitat Variation and Digestion Rate on Feeding in Freshwater Fishes

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    My research was designed to evaluate predator-prey relationships in Lake Erie and the effects of watersheds, through river inputs, on prey consumption. I analyzed stomach contents of fishes collected from two distinct river plumes in Lake Erie\u27s western basin to see if elevated turbidity in one river plume reduced predation mortality of larval fishes. I found that quantifying larval fish predation mortality is a difficult task; only 16 of 3,467 stomachs analyzed contained larval prey. I used laboratory experiments to evaluate digestion rates of larval fishes and found that both the complete breakdown of larvae in predator stomachs and the loss of morphological characters needed to identify larvae occurred rapidly, suggesting that conventional diet analyses are inadequate for quantifying larval predation mortality. My diet analyses did reveal spatial and temporal differences in prey consumption between river plumes, which are likely being driven by bottom-up and top-down effects associated with inputs of nutrients and sediments from tributary streams. Collectively, my results will allow managers to quantify the likelihood of detecting larval fishes during stomach content analyses and to better understand how tributary inputs influence predator-prey interactions

    Tropical Pacific observing for the next decade

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    More than 60 scientists and program officials from 13 countries met at the Scripps Institution of Oceanography for the Tropical Pacific Observing System (TPOS) 2020 Workshop. The workshop, although motivated in part by the dramatic decline of NOAA's Tropical Atmosphere Ocean (TAO) buoy reporting from mid‐2012 to early 2014 (see http://www.bloomberg.com/news/2014‐03‐07/aging‐el‐nino‐buoys‐getting‐fixed‐as‐weather‐forecasts‐at‐risk.html), evaluated the needs for tropical Pacific observing and initiated efforts to develop a more resilient and integrative observing system for the future

    The CRCES Workshop on Decadal Climate Variability

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    Author Posting. © American Meteorological Society, 2006. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 87 (2006): 1223–1225, doi:10.1175/BAMS-87-9-1223.The importance of decadal climate variability (DCV) research is being increasingly recognized, including by international research programs such as the World Climate Research Program (WCRP) and the U.S. National Research Council. This brief article (workshop presentations available online at www.DecVar.org/auditorium.php) summarizes a consensus view of a research community workshop attended by approximately 45 scientists. Gaps in our knowledge of DCV and its societal impacts were identified, as were areas of needed research and anticipated benefits of research. It is a major challenge to implement recommendations of this and other such workshops on climate research in this era of declining earth science budgets. Therefore, a phased implementation is recommended, with highest priority recommendations outlined in a sidebar to this summary

    A 1-acetamido derivative of 6-epi-valienamine: an inhibitor of a diverse group of ÎČ-N-acetylglucosaminidases

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    The synthesis of an analogue of 6-epi-valienamine bearing an acetamido group and its characterisation as an inhibitor of ÎČ-N-acetylglucosaminidases are described. The compound is a good inhibitor of both human O-GlcNAcase and human ÎČ-hexosaminidase, as well as two bacterial ÎČ-N-acetylglucosaminidases. A 3-D structure of the complex of Bacteroides thetaiotaomicron BtGH84 with the inhibitor shows the unsaturated ring is surprisingly distorted away from its favoured solution phase conformation and reveals potential for improved inhibitor potency

    What we have learned from the framework for ocean observing: evolution of the global ocean observing system

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    The Global Ocean Observing System (GOOS) and its partners have worked together over the past decade to break down barriers between open-ocean and coastal observing, between scientific disciplines, and between operational and research institutions. Here we discuss some GOOS successes and challenges from the past decade, and present ideas for moving forward, including highlights of the GOOS 2030 Strategy, published in 2019. The OceanObs’09 meeting in Venice in 2009 resulted in a remarkable consensus on the need for a common set of guidelines for the global ocean observing community. Work following the meeting led to development of the Framework for Ocean Observing (FOO) published in 2012 and adopted by GOOS as a foundational document that same year. The FOO provides guidelines for the setting of requirements, assessing technology readiness, and assessing the usefulness of data and products for users. Here we evaluate successes and challenges in FOO implementation and consider ways to ensure broader use of the FOO principles. The proliferation of ocean observing activities around the world is extremely diverse and not managed, or even overseen by, any one entity. The lack of coherent governance has resulted in duplication and varying degrees of clarity, responsibility, coordination and data sharing. GOOS has had considerable success over the past decade in encouraging voluntary collaboration across much of this broad community, including increased use of the FOO guidelines and partly effective governance, but much remains to be done. Here we outline and discuss several approaches for GOOS to deliver more effective governance to achieve our collective vision of fully meeting society’s needs. What would a more effective and well-structured governance arrangement look like? Can the existing system be modified? Do we need to rebuild it from scratch? We consider the case for evolution versus revolution. Community-wide consideration of these governance issues will be timely and important before, during and following the OceanObs’19 meeting in September 2019

    Birth Weight and Prenatal Exposure to Polychlorinated Biphenyls (PCBs) and Dichlorodiphenyldichloroethylene (DDE): A Meta-analysis within 12 European Birth Cohorts

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    Objectives: Exposure to high concentrations of persistent organochlorines may cause fetal toxicity, but the evidence at low exposure levels is limited. Large studies with substantial exposure contrasts and appropriate exposure assessment are warranted. Within the framework of the EU (European Union) ENRIECO (ENvironmental Health RIsks in European Birth Cohorts) and EU OBELIX (OBesogenic Endocrine disrupting chemicals: LInking prenatal eXposure to the development of obesity later in life) projects, we examined the hypothesis that the combination of polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) adversely affects birth weight

    The Joint IOC (of UNESCO) and WMO collaborative effort for met-ocean services

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    The Joint Committee for Oceanography and Marine Meteorology (JCOMM), a joint technical commission of IOC of UNESCO and WMO, has devised a coordination mechanism for the fit-for-purpose delivery of an end-to-end system, from ocean observations to met-ocean operational services. This paper offers a complete overview of the activities carried out by JCOMM and the status of the achievements up to 2017. The JCOMM stakeholders are the WMO Members and the IOC Member States, their research and operational Institutions, which mandated JCOMM to devise an international strategy to advance toward the achievement of the United Nations Sustainable Development Goals. The three activity areas, namely the Observation Program Area-OPA, the Data Management Program Area-DMPA and the Services and Forecasting Services Program Area-SFSPA have established several expert teams to contribute to the international coordination. OPA is organized in observing networks connected with different observing technologies, DMPA organizes the overall near-real time and delayed mode data assembly and delivery methodology and architecture and the SFSPA coordinates the met-ocean services stemming out of observations and data management. The future developments should strengthen the coordination in the three program areas considering the inclusion of new and emergent observing technologies, the interoperability of met-ocean data assembly centers and the establishment of efficient research to operations protocols, as well as better fit-for-purpose customized services for the public and private sectors

    Measuring global ocean heat content to estimate the earth energy imbalance

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    The energy radiated by the Earth toward space does not compensate the incoming radiation from the Sun leading to a small positive energy imbalance at the top of the atmosphere (0.4–1 Wm–2). This imbalance is coined Earth’s Energy Imbalance (EEI). It is mostly caused by anthropogenic greenhouse gas emissions and is driving the current warming of the planet. Precise monitoring of EEI is critical to assess the current status of climate change and the future evolution of climate. But the monitoring of EEI is challenging as EEI is two orders of magnitude smaller than the radiation fluxes in and out of the Earth system. Over 93% of the excess energy that is gained by the Earth in response to the positive EEI accumulates into the ocean in the form of heat. This accumulation of heat can be tracked with the ocean observing system such that today, the monitoring of Ocean Heat Content (OHC) and its long-term change provide the most efficient approach to estimate EEI. In this community paper we review the current four state-of-the-art methods to estimate global OHC changes and evaluate their relevance to derive EEI estimates on different time scales. These four methods make use of: (1) direct observations of in situ temperature; (2) satellite-based measurements of the ocean surface net heat fluxes; (3) satellite-based estimates of the thermal expansion of the ocean and (4) ocean reanalyses that assimilate observations from both satellite and in situ instruments. For each method we review the potential and the uncertainty of the method to estimate global OHC changes. We also analyze gaps in the current capability of each method and identify ways of progress for the future to fulfill the requirements of EEI monitoring. Achieving the observation of EEI with sufficient accuracy will depend on merging the remote sensing techniques with in situ measurements of key variables as an integral part of the Ocean Observing System
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