University of Wisconsin-Madison

About: University of Wisconsin-Madison is a education organization based out in Madison, Wisconsin, United States. It is known for research contribution in the topics: Population & Gene. The organization has 108707 authors who have published 237594 publications receiving 11883575 citations.

A handful of heuristics and some propositions for understanding resilience in social-ecological systems

Abstract: This paper is a work-in-progress account of ideas and propositions about resilience in socialecological systems. It articulates our understanding of how these complex systems change and what determines their ability to absorb disturbances in either their ecological or their social domains. We call them “propositions” because, although they are useful in helping us understand and compare different social-ecological systems, they are not sufficiently well defined to be considered formal hypotheses. These propositions were developed in two workshops, in 2003 and 2004, in which participants compared the dynamics of 15 case studies in a wide range of regions around the world. The propositions raise many questions, and we present a list of some that could help define the next phase of resilience-related research.

Molecular Basis for High Virulence of Hong Kong H5N1 Influenza A Viruses

Abstract: In 1997, an H5N1 influenza A virus was transmitted from birds to humans in Hong Kong, killing 6 of the 18 people infected. When mice were infected with the human isolates, two virulence groups became apparent. Using reverse genetics, we showed that a mutation at position 627 in the PB2 protein influenced the outcome of infection in mice. Moreover, high cleavability of the hemagglutinin glycoprotein was an essential requirement for lethal infection.

The Pristine Myth: The Landscape of the Americas in 1492

Abstract: The myth persists that in 1492 the Americas were a sparsely populated wilder- ness, "a world of barely perceptible human disturbance." There is substantial evidence, however, that the Native American landscape of the early sixteenth century was a humanized landscape almost everywhere. Populations were large. Forest composition had been modified, grasslands had been created, wild- life disrupted, and erosion was severe in places. Earthworks, roads, fields, and settle- ments were ubiquitous. With Indian depopu- lation in the wake of Old World disease, the environment recovered in many areas. A good argument can be made that the human pres- ence was less visible in 1750 than it was in 1492.

Observed Properties of Interstellar Dust

Abstract: Recent information on the observed properties of interstellar dust is reviewed, with an attempt made to clarify some of the observational uncertainties associated with obtaining dust parameters. Attention is given to interstellar extinction, the interstellar dust distribution, the dust-to-gas ratio, and light scattering by dust grains. Interstellar polarization is also examined, along with heavy-element depletion in the interstellar medium, thermal emission from interstellar dust grains, diffuse interstellar features, and the composition and origin of interstellar grains.