162 research outputs found
Recent cooling in coastal southern Greenland and relation with the North Atlantic Oscillation
Analysis of new data for eight stations in coastal southern Greenland, 1958-2001, shows a significant cooling (trend-line change -1.29°C for the 44 years), as do sea-surface temperatures in the adjacent part of the Labrador Sea, in contrast to global warming (+0.53°C over the same period). The land and sea temperature series follow similar patterns and are strongly correlated but with no obvious lead/lag either way. This cooling is significantly inversely correlated with an increased phase of the North Atlantic Oscillation (NAO) over the past few decades (r = -0.76), and will probably have significantly affected the mass balance of the Greenland Ice Sheet
Averting HIV Infections in New York City: A Modeling Approach Estimating the Future Impact of Additional Behavioral and Biomedical HIV Prevention Strategies
Background:New York City (NYC) remains an epicenter of the HIV epidemic in the United States. Given the variety of evidence-based HIV prevention strategies available and the significant resources required to implement each of them, comparative studies are needed to identify how to maximize the number of HIV cases prevented most economically.Methods:A new model of HIV disease transmission was developed integrating information from a previously validated micro-simulation HIV disease progression model. Specification and parameterization of the model and its inputs, including the intervention portfolio, intervention effects and costs were conducted through a collaborative process between the academic modeling team and the NYC Department of Health and Mental Hygiene. The model projects the impact of different prevention strategies, or portfolios of prevention strategies, on the HIV epidemic in NYC.Results:Ten unique interventions were able to provide a prevention benefit at an annual program cost of less than 106,378; the total cost was in excess of 100 million per year, on average). The cost-savings of prevented infections was estimated at more than 250 million per year, on average).Conclusions:Optimal implementation of a portfolio of evidence-based interventions can have a substantial, favorable impact on the ongoing HIV epidemic in NYC and provide future cost-saving despite significant initial costs. © 2013 Kessler et al
Impact of model physics on estimating the surface mass balance of the Greenland ice sheet
Long-term predictions of sea level rise from increased Greenland ice sheet melting have been derived using Positive Degree Day models only. It is, however, unknown precisely what uncertainties are associated with applying this simple surface melt parameterization for future climate. We compare the behavior of a Positive Degree Day and Energy Balance/ Snowpack model for estimating the surface mass balance of the Greenland ice sheet under a warming climate. Both models were first tuned to give similar values for present-day mass balance using 10 years of ERA-40 climatology and were then run for 300 years, forced with the output of a GCM in which atmospheric CO2 increased to 4 times preindustrial levels. Results indicate that the Positive Degree Day model is more sensitive to climate warming than the Energy Balance model, generating annual runoff rates almost twice as large for a fixed ice sheet geometry. Roughly half of this difference was due to differences in the volume of melt generated and half was due to differences in refreezing rates in the snowpack. Our results indicate that the modeled snowpack properties evolve on a multidecadal timescale to changing climate, with a potentially large impact on the mass balance of the ice sheet; an evolution that was absent from the Positive Degree Day model. Copyright 2007 by the American Geophysical Union
Die transnationale Ordnung globalisierter Finanzmärkte. Was lehrt uns die Krise?
Die Krise der Finanzmärkte, die 2007 begann, hat die meisten Politiker und Wissenschaftler überrascht. In der Soziologie haben, wie in der Wirtschaftswissenschaft, vor 2007 nur Wenige das Krisenpotenzial erkannt, das in der Beschaffenheit des modernen Finanzsystems liegt. Unter dem dominanten Einfluss der liberalen Neoklassik in der ökonomischen Theorie wurde weithin geglaubt, dass Märkte im Allgemeinen und damit auch Finanzmärkte sich selbst regeln. Die Finanzkrise und ihre Folgen haben hier zu einem Umdenken geführt. Inzwischen besteht unter Wissenschaftlern und Politikern ein breiter Konsens, dass Defizite der Regulierung für die krisenhafte Entwicklung im globalen Finanzsystem mit verantwortlich waren. Da die Finanzmärkte globalisiert sind und die Krise als eine globale wahrgenommen wurde, wurde allgemein eine Neuregelung durch Vereinbarungen auf internationaler Ebene verlangt, um künftigen Krisen vorzubauen
Compliance to fingolimod and other disease modifying treatments in multiple sclerosis patients, a retrospective cohort study
Transnational Governance as Contested Institution-Building: China, Merchants, and Contract Rules in the Cotton Trade
We are in an era of uncertainty over whose rules will govern global economic integration. With the growing market share of Chinese firms and the power of the Chinese state it is unclear if Western firms will continue to dominate transnational governance. Exploring these dynamics through a study of contract rules in the global cotton trade, this article conceptualizes commodity chain governance as a contested process of institution-building. To this end, the global commodity chain/global value chain (GCC/GVC) framework must be revised to better account for the broader institutional context of commodity chain governance, institutional variation across space, and strategic action in the construction of legitimate governance arrangements. I provide a more dynamic model of GCC governance that stresses how strategic action, existing institutions, and dominant discourses intersect as firms and states compete for institutional power within a commodity chain. This advances our understandings of how commodity chain governance emerges and changes over time
A systematic review of the impacts and management of introduced deer (family Cervidae) in Australia
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The Inner-Shelf Dynamics Experiment
17 USC 105 interim-entered record; under review.The article of record as published may be found at http://dx.doi.org/10.1175/BAMS-D-19-0281.1The inner shelf, the transition zone between the surfzone and the midshelf, is a dynamically complex region with the evolution of circulation and stratification driven by multiple physical processes. Cross-shelf exchange through the inner shelf has important implications for coastal water quality, ecological connectivity, and lateral movement of sediment and heat. The Inner-Shelf Dynamics Experiment (ISDE) was an intensive, coordinated, multi-institution field experiment from September–October 2017, conducted from the midshelf, through the inner shelf, and into the surfzone near Point Sal, California. Satellite, airborne, shore- and ship-based remote sensing, in-water moorings and ship-based sampling, and numerical ocean circulation models forced by winds, waves, and tides were used to investigate the dynamics governing the circulation and transport in the inner shelf and the role of coastline variability on regional circulation dynamics. Here, the following physical processes are highlighted: internal wave dynamics from the midshelf to the inner shelf; flow separation and eddy shedding off Point Sal; offshore ejection of surfzone waters from rip currents; and wind-driven subtidal circulation dynamics. The extensive dataset from ISDE allows for unprecedented investigations into the role of physical processes in creating spatial heterogeneity, and nonlinear interactions between various inner-shelf physical processes. Overall, the highly spatially and temporally resolved oceanographic measurements and numerical simulations of ISDE provide a central framework for studies exploring this complex and fascinating region of the ocean.U.S. Office of Naval Research (ONR)ONR Departmental Research Initiative (DRI)Inner-Shelf Dynamics Experiment (ISDE
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