Effects of Natural Barriers and Habitat on the Western Spread of Raccoon Rabies in Alabama

2008 ◽  
Vol 72 (8) ◽  
pp. 1725-1735 ◽  
Author(s):  
Wendy M. Arjo ◽  
Christine E. Fisher ◽  
James Armstrong ◽  
Frank Boyd ◽  
Dennis Slate
Keyword(s):  
Natural Barriers

Natural Barriers and Internal Sources for the Reproductive Isolation in Sympatric Salmonids from the Lake–River System

2021 ◽  
Author(s):  
G. N. Markevich ◽  
D. V. Zlenko ◽  
F. N. Shkil ◽  
U. K. Schliewen ◽  
L. A. Anisimova ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
River System ◽  
Internal Sources ◽  
Natural Barriers

This Little Piggy Went to Market: The Xenotransplantation and Xenozoonose Debate

1999 ◽  
Vol 27 (2) ◽  
pp. 137-152 ◽  
Author(s):  
Margaret A. Clark
Keyword(s):  
New Technologies ◽  
Unintended Consequences ◽  
Human Beings ◽  
Policy Issues ◽  
Recent Letter ◽  
Ethical Concerns ◽  
Private Citizens ◽  
Clinical Risks ◽  
Natural Barriers

New technologies are changing our lives radically and quickly. New biotechnologies are moving to commercial uses faster than government regulators or private citizens can monitor. This tension manifests itself in the current debates over xenotransplantation technologies in medicine. The possibility of removing cells, tissues, and organs from animals and transplanting them into human beings is startling and unnerving. Natural immunesystem barriers between species, and even between individuals within a species, are formidable. Typically, transplantation results in violent rejection and death of the grafted organ. But despite the natural barriers to transplantation, xenotransplantation aims specifically to overcome them.In this paper, I will discuss applications of xenograft technology, which raises clinical risks, ethical concerns, and policy issues. I conclude with a set of specific recommendations. As a recent letter to the journal Nature puts it, there is a “split between those who want to get it right, and those who want to get it right now.” No one knows what all the risks, benefits, and unintended consequences of xenotransplantation will be.

Trees as natural barriers against heavy metal pollution and their role in the protection of cultural heritage

2014 ◽  
Vol 15 (3) ◽  
pp. 227-233 ◽  
Author(s):  
Katarina Kocić ◽  
Tijana Spasić ◽  
Mira Aničić Urošević ◽  
Milica Tomašević
Keyword(s):  
Heavy Metal ◽  
Cultural Heritage ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Natural Barriers ◽  
Protection Of Cultural Heritage

scholarly journals Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks

2018 ◽  
Vol 482 (1) ◽  
pp. 261-283 ◽  
Author(s):  
S. Finsterle ◽  
B. Lanyon ◽  
M. Åkesson ◽  
S. Baxter ◽  
M. Bergström ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Nuclear Waste ◽  
Task Force ◽  
Coupled System ◽  
Rock Interaction ◽  
Complex Interactions ◽  
Bentonite Buffer ◽  
Waste Repositories ◽  
The Impact ◽  
Natural Barriers

AbstractNuclear waste disposal in geological formations relies on a multi-barrier concept that includes engineered components – which, in many cases, include a bentonite buffer surrounding waste packages – and the host rock. Contrasts in materials, together with gradients across the interface between the engineered and natural barriers, lead to complex interactions between these two subsystems. Numerical modelling, combined with monitoring and testing data, can be used to improve our overall understanding of rock–bentonite interactions and to predict the performance of this coupled system. Although established methods exist to examine the prediction uncertainties due to uncertainties in the input parameters, the impact of conceptual model decisions on the quantitative and qualitative modelling results is more difficult to assess. A Swedish Nuclear Fuel and Waste Management Company Task Force project facilitated such an assessment. In this project, 11 teams used different conceptualizations and modelling tools to analyse the Bentonite Rock Interaction Experiment (BRIE) conducted at the Äspö Hard Rock Laboratory in Sweden. The exercise showed that prior system understanding along with the features implemented in the available simulators affect the processes included in the conceptual model. For some of these features, sufficient characterization data are available to obtain defensible results and interpretations, whereas others are less supported. The exercise also helped to identify the conceptual uncertainties that led to different assessments of the relative importance of the engineered and natural barrier subsystems. The range of predicted bentonite wetting times encompassed by the ensemble results were considerably larger than the ranges derived from individual models. This is a consequence of conceptual uncertainties, demonstrating the relevance of using a multi-model approach involving alternative conceptualizations.

Solubility data in radioactive waste disposal

2007 ◽  
Vol 79 (5) ◽  
pp. 875-882 ◽  
Author(s):  
Hans Wanner
Keyword(s):  
Radioactive Waste ◽  
Human Health ◽  
Nuclear Power ◽  
Spent Nuclear Fuel ◽  
Radioactive Waste Disposal ◽  
Potential Hazard ◽  
Reliable Assessment ◽  
Deep Geological Disposal ◽  
Equilibrium Data ◽  
Natural Barriers

Radioactive waste arises mainly from the generation of nuclear power but also from the use of radioactive materials in medicine, industry, and research. It occurs in a variety of forms and may range from slightly to highly radioactive. It is a worldwide consensus that radioactive waste should be disposed of in a permanent way which ensures protection of humans and the environment. This objective may be achieved by isolating radioactive waste in a disposal system which is located, designed, constructed, operated, and closed such that any potential hazard to human health is kept acceptably low, now and in the future.For highly radioactive waste and spent nuclear fuel, which are the waste types representing the highest potential danger to human health, an effective isolation from the biosphere is considered to be achievable by deep geological disposal. Disposal concepts rely on the passive safety functions of a series of engineered and natural barriers. Since total isolation over extended timescales is not possible, radionuclides will eventually be released from the waste matrix and migrate through the engineered and natural barriers. The assessment of their mobility in these environments is essential for the safety demonstration of such a repository. The solubility of many radionuclides is limited and may contribute significantly to retention. Reliable predictions of solubility limitations are therefore important.Predictions of maximum solubilities are always subject to uncertainties. Complete sets of thermodynamic and equilibrium data are required for a reliable assessment of the chemical behavior of the radionuclides. Gaps in the thermodynamic databases may lead to erroneous predictions. Missing data and insufficient knowledge of the solubility-limiting processes increase the uncertainties and require pessimistic assumptions in the safety analysis; however, these are usually not detrimental to safety owing to the robustness of the multi-barrier approach.

Technological Diffusion in Agriculture Under the Bakuhan System

1971 ◽  
Vol 30 (4) ◽  
pp. 749-759 ◽  
Author(s):  
Kee Il Choi
Keyword(s):  
Population Density ◽  
Technology Diffusion ◽  
Technological Diffusion ◽  
Land Productivity ◽  
Interregional Trade ◽  
Great Inflation ◽  
Set Up ◽  
Natural Barriers

Ohkawa and Rosovsky allege that the jump in Meiji land productivity was the result of exploitation of a large technological backlog which the Bakuhan system created in the advanced region of Tokugawa Japan, such as kinki, by blocking technological diffusion. This allegation is without factual substance—land productivity was probably the highest in the kinki region (prefectures of Kyoto, Osaka, Nara, Wakayama, Mie, Hyogo, and Shiga), but this region was the last place where farming technology could have been bottled up. The han governments could not set up effective artificial barriers there because their landholdings were so fragmented and so intermingled with others in kinki and also because technology-diffusion forces such as traffic, population density, and commercialization were so great. Therefore, it is the specialization of land and labor in order to produce certain crops for the market that was largely responsible for the high land productivity in kinki. Likewise, it is highly likely that the alleged rise in Meiji land productivity can be attributed chiefly to accelerated commercialization and specialization, brought about by the coming of railroads, the commutation of taxes, the great inflation (1877–1881), and general changes in demand. Autonomous and competitive han, driven by the necessity of meeting their increasing expenditures, expanded interregional trade and diffused, rather than obstructed, technology thus overcoming artificial and natural barriers.

Sign in / Sign up

Export Citation Format

Share Document