Opportunity, Willingness, and the Diffusion of War

Using borders and alliances as indicators of opportunity and willingness, respectively, we test the relationship between the sea and the diffusion of war during the 1816-1965 period. The impact of borders and alliances, individually and in combination, on the growth of ongoing war through infectious diffusion is shown through the comparison of baseline cases to cases where states at peace were exposed to various treatments comprised of warring border nations or warring alliance partners. The findings indicate that the probability of war diffusion is substantially increased as opportunities and willingness increase, particularly when such geographic and political factors are combined. The applicability of the opportunity and willingness framework to the study of war and diffusion is expanded and confirmed

Trigger-happy? Military regimes and the timing of conflict

The proclivity of military regimes and their leaders for more frequent involvement in international conflict than other autocracies has been shown in several studies. The question raised here is not whether they participate in more conflicts and disputes, but rather whether after the leaders of military regimes enter office they initiate these acts more quickly than the leaders of other types of autocracies. Drawing on three authoritarian regime typologies and examining the time to the initiation of any dispute and the initiation of violent disputes, our results show that in comparison to other authoritarian leaders a subset of military leaders is distinctly trigger-happy

Demography, Democracy and Disputes: The Search for the Elusive Relationship Between Population Growth and International Conflict

AbstractWe examine the propensity of states to initiate international conflict conditioned on four primary explanatory variables: (1) changes in population over varying lags, (2) democratic status of the state, (3) the power status of the state, and (4) changes in the state's level of energy consumption. We hypothesize that the responsiveness of a government to the needs of its citizens is sufficiently important that the effect of population growth cannot be properly examined independently of democracy and that major powers tend to become involved in disputes for a much wider set of reasons than minor powers. Thus, we expect to find the strongest effect of population change on conflict initiation in democratic minor powers. We also expect that decreases in energy consumption concurrent with increases in population will lead to conflict initiation. A series of negative binomial regressions over 20 yearly time lags lends robust support to our expectations

Selection institutions and war aims

We explore how the sizes of the winning coalition and selectorate influence the war aims of states. Leaders who answer to a small winning coalition are more likely to seek territorial gain as a way to increase state resources. Nonterritorial war aims produce a commitment problem in that after the war the defeated state may not comply with the victor's demands. States with large winning coalitions are more willing to continue the war to remove the enemy leader as a solution to this commitment problem. We test our hypotheses against the Militarized Interstate Dispute data set, and we find some support for our argument.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47901/1/10101_2005_Article_108.pd

The Geography of the International System: The CShapes Dataset

We describe CShapes, a new dataset that provides historical maps of state boundaries and capitals in the post-World War II period. The dataset is coded according to both the Correlates of War and the Gleditsch and Ward (1999) state lists, and is therefore compatible with a great number of existing databases in the discipline. Provided in a geographic data format, CShapes can be used directly with standard GIS software, allowing a wide range of spatial computations. In addition, we supply a CShapes package for the R statistical toolkit. This package enables researchers without GIS skills to perform various useful operations on the GIS maps. The paper introduces the CShapes dataset and structure and gives three examples of how to use CShapes in political science research. First, we show how results from quantitative analysis can be depicted intuitively as a map. The second application gives an example of computing indicators on the CShapes maps, which can then be used in statistical tests. Third, we illustrate the use of CShapes for generating different weights matrices in spatial statistical applications. All the examples can be replicated using the freely available R package and do not require specialized GIS skills. The dataset is available for download from the CShapes website (http://nils.weidmann.ws/projects/cshapes). © Taylor & Francis Group, LLC

Sharks of the order Carcharhiniformes from the British Coniacian, Santonian and Campanian (Upper Cretaceous).

Bulk sampling of phosphate-rich horizons within the British Coniacian to Campanian (Upper Cretaceous) yielded very large samples of shark and ray teeth. All of these samples yielded teeth of diverse members of the Carcharhiniformes, which commonly dominate the fauna. The following species are recorded and described: Pseudoscyliorhinus reussi (Herman, 1977) comb. nov., Crassescyliorhinus germanicus (Herman, 1982) gen. nov., Scyliorhinus elongatus (Davis, 1887), Scyliorhinus brumarivulensis sp. nov., ? Palaeoscyllium sp., Prohaploblepharus riegrafi (Müller, 1989) gen. nov., ? Cretascyliorhinus sp., Scyliorhinidae inc. sedis 1, Scyliorhinidae inc. sedis 2, Pteroscyllium hermani sp. nov., Protoscyliorhinus sp., Leptocharias cretaceus sp. nov., Palaeogaleus havreensis Herman, 1977, Paratriakis subserratus sp. nov., Paratriakis tenuis sp. nov., Paratriakis sp. indet. and ? Loxodon sp. Taxa belonging to the families ?Proscylliidae, Leptochariidae, and Carcharhinidae are described from the Cretaceous for the first time. The evolutionary and palaeoecological implications of these newly recognised faunas are discussed

A Gigantic Shark from the Lower Cretaceous Duck Creek Formation of Texas

Author Contributions Conceived and designed the experiments: JAF SNS JAD-F. Analyzed the data: JAF SNS. Wrote the paper: JAF SNS. Site data for OMNH V1727 are available by request from the department of vert. paleontology at the (SN)OMNH.Three large lamniform shark vertebrae are described from the Lower Cretaceous of Texas. We interpret these fossils as belonging to a single individual with a calculated total body length of 6.3 m. This large individual compares favorably to another shark specimen from the roughly contemporaneous Kiowa Shale of Kansas. Neither specimen was recovered with associated teeth, making confident identification of the species impossible. However, both formations share a similar shark fauna, with Leptostyrax macrorhiza being the largest of the common lamniform sharks. Regardless of its actual identification, this new specimen provides further evidence that large-bodied lamniform sharks had evolved prior to the Late Cretaceous.Ye

Development of Atmospheric Tracer Methods To Measure Methane Emissions from Natural Gas Facilities and Urban Areas

A new, integrated methodology to locate and measure methane emissions from natural gas systems has been developed. Atmospheric methane sources are identified by elevated ambient CH4 concentrations measured with a mobile laser-based methane analyzer. The total methane emission rate from a source is obtained by simulating the source with a sulfur hexafluoride (SF6) tracer gas release and by measuring methane and tracer concentrations along downwind sampling paths using mobile, real-time analyzers. Combustion sources of methane are distinguished from noncombustion sources by concurrent ambient carbon dioxide measurements. Three variations on the tracer ratio method are described for application to (1) small underground vaults, (2) aboveground natural gas facilities, and (3) diffuse methane emissions from an entire town. Results from controlled releases and from replicate tests demonstrate that the tracer ratio approach can yield total emission rates to within approximately ±15%. The estimated accuracy of emission estimates for urban areas with a variety of diffuse emissions is ±50%. © 1995, American Chemical Society. All rights reserved