2,305 research outputs found
Rediscovering the Maryland Darter (Etheostoma sellare)
The Maryland darter has not been observed since 1988. Historic populations were located in Deer Creek, Swan Creek, and Gasheyâs Run all of which occur in the lower Susquehanna drainage. At these locations, specimens were collected or observed at the lowest riffle of the stream. Some researchers suggest this may be a large river darter. The Conowingo Dam complicates surveying below the facility due to the rapid fluctuations in water levels caused by regulation for power production. Surveying efforts included trawling in the mainstem, and visual surveys in the mainstem, and searching/sampling all historically known locations of Etheostoma sellare. During this study 153 Benthic trawls totaling 272.4 minutes of bottom time yielded no Maryland darters. Also 10,452 fish were collected from 4 tributary sites (3 historic and 1 new) yielding no Maryland Darters. In addition, during 307.1 man-hours of visual surveys no Maryland darters were observed. Considering the data from this study it is apparent that the Maryland darter has declined within its historical range. However, habitat assessment of new sites showed that habitat similar to E. sellareâs historical habitat still exists in the Susquehanna mainstem and tributaries. Additional surveys are needed to determine if the Maryland darter is extant
The Information Needs of Mobile Searchers: A Framework
The growing use of Internet-connected mobile devices demands
that we reconsider search user interface design in light of the
context and information needs specific to mobile users. In this
paper the authors present a framework of mobile information
needs, juxtaposing search motivesâcasual, lookup, learn, and
investigateâwith search typesâinformational, geographic,
personal information management, and transactional
The Value of Comparative Animal Research : Kroghâs Principle Facilitates Scientific Discoveries
There are no conflicts of interest to declare. This paper developed from the 2016 Early Career Impact Award from the Federation of Associations in Behavioral & Brain Sciences to TJS. TJS has received funding from The Leverhulme Trust. FJPE is in receipt of funding from the BBSRC (BB/M001555/1). The National Institutes of Health has funded RDF (NS 034950, NS093277, NIMH 087930), AGO (HD079573, IOS-1354760) and AMK (HD081959). BAA is an Arnold O. Beckman postdoctoral fellow.Peer reviewedPostprin
Evolution of the Antarctic Peninsula continental margin from Late Eocene to present: Seismic stratigraphic analysis related to the development of the Antarctic Peninsula Ice Sheet (APIS)
This investigation into Antarctic Peninsula Ice Sheet (APIS) development represents research from the stratigraphic record of three geographic areas: The James Ross Basin (northwestern Weddell Sea), the Pacific continental margin of the Antarctic Peninsula, and the Joinville Slope (northwestern Weddell Sea).
The stratigraphic architecture of the James Ross Basin, NW Weddell Sea continental shelf, shows three major phases of deposition: pre-glacial, ice sheet growth, and ice sheet dominated. Each stratigraphic unit is characterized based upon seismic facies and stratigraphic architecture, and the ages are inferred from a seismic stratigraphic age model. A total of 34 grounding events of the Antarctic Peninsula Ice Sheet (APIS) are recorded on the continental shelf. The seven oldest glacial unconformities are believed to pre-date all previously identified unconformities on the peninsula continental shelf. An expanded section of Late Pliocene/Pleistocene deposits show a minimum of 10 grounding events.
Isopachs of sedimentary sequences on the Antarctic Peninsula Pacific continental margin show shifting depocenters through time. Chronostratigraphic and seismic depth-converted data from ODP 178 cores allow the calculation of sediment flux for shelf units S3-S1 and rise units M6-M1. Sediment flux to the margin increases from the Late Eocene until the Late Pliocene and then decreases slightly from Late Pliocene to present. Significant increases in sediment flux coincide with early development of the APIS and during the early Pliocene warming period (Barker and Camerlenghi, 2002). Minimum glacial denudation rates for the Antarctic Peninsula are in the range of 0.06 to 0.13 mm yr -1.
The Joinville Slope sediment wedge located in the northwestern Weddell Sea shows seismic stratigraphic evidence of mixed turbidite/contourite/hemipelagic deposition. A prominent seafloor unconformity and the exposed and eroded basement of the adjacent continental shelf indicate erosion by grounded ice during the Plio-Pleistocene. SHALDRIL recovered core at three drill sites, 12A, 5C, and 6D, and sampled sediments from the upper Oligocene, middle Miocene, and lower and upper Pliocene which are constrained by diatom and calcareous nannofossil assemblages. The sediment wedge shows no apparent hiatuses or large unconformities from Late Oligocene to the Lower Pliocene. Regional sedimentation rates show continuous sedimentation throughout the Late Paleogene and Neogene
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Domestic Surveillance in the United States: World War II to Vietnam
This dissertation examines archival documents as well as Congressional committee investigations and records to understand the scope and legality of domestic surveillance in the mid-twentieth century. Additionally, it works to understand how the intelligence agencies that carried out such surveillance were able to avoid meaningful punishment, even though their actions were often illegal. There has been a recent revival of concerns over the abilities of secret intelligence agencies to intercept and examine the communications of U.S. citizens. While the current revelations about domestic surveillance are certainly disconcerting, the reality is that domestic surveillance has a long and sordid history in the United States. With the advent and adoption of new technologies for communication, government access to the words and ideas of citizens proliferated in the twentieth century. This meant that surveillance could be carried out more broadly and efficiently than ever before. Such surveillance captured the communications of politicians, activists, workers, students, parents, teachers, Martin Luther King, Jr., and even Supreme Court Justices. The aim of this dissertation is two-fold. First, it seeks to understand how such surveillance impacts civil liberties, with special attention paid to First Amendment protections of speech, the press, and association, and Fourth Amendment protections against unwarranted search and seizure. This work finds that government surveillance has the consequences of chilling speech and stifling intellectual privacy. This study examines National Security Agency operations SHAMROCK and MINARET; Federal Bureau of Investigation Counterintelligence Program (COINTELPRO) operations Communist Party USA, Socialist Workers Party, Black Nationalist Hate Groups, and New Left; and Central Intelligence Agency operations HTLINGUAL, CHAOS, MERRIMAC, and RESISTANCE. The examination of these operations concludes that the NSA, FBI, and CIA fundamentally violated the constitutional rights of countless citizens and these violations were carried out knowingly and repeatedly. The second aim of this dissertation is to investigate how these agencies were able to avoid meaningful punishment. To understand how they skirted punishment, it is necessary to think of the United States as a dual state. The dual state theory was developed in the 1930s by German legal scholar and political scientist Ernst Fraenkel. Fraenkel sought to understand the political, economic and legal changes taking place in Germany under the Third Reich. His theory suggests that in a dual state, there is Normative State, which is charged with enforcing normative laws such as contract and traffic law, and there is a Prerogative State, which arbitrarily applies laws to groups and individuals determined to be acting “politically” or in ways that threaten the current regime—in Germany, the Prerogative State was synonymous with the Gestapo. In much the same way, members of the American Prerogative State arbitrarily apply and suspend laws based on their perceptions of individual and group activities and ideologies. They can violate the constitutional rights of those people and organizations believed to threaten the government. Thus, the NSA, FBI, and CIA are not only members of the intelligence community, they are also members of the American Prerogative State and, as such, are able to violate laws with impunity. The dual state theory explains why these agencies were not punished for the illegal and unconstitutional surveillance practices that took place between World War II and the Vietnam War.</p
Financial Implications from Contracting Avian Influenza in a U.S. Broiler Operation
This essay evaluates the on-farm financial impacts of an avian influenza outbreak on a U.S. commercial broiler operation. It investigates how the timing and length of the outbreak impacts farm financial performance for two different farmers, beginning and experienced. Results indicate that a beginning farmer is more susceptible to significant financial losses. Both farmers are financially impacted more when avian influenza is contracted early in the investment and when the contamination and eradication of the virus was prolonged. Furthermore, this essay highlights the problems of using standard financial measures for analyzing disease outbreaks under production contract arrangements and presents alternative measures for financial performance. This study provides the foundation for future research to determine actuarially fair premiums for avian influenza insurance mechanisms
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