308 research outputs found
A Worst Practices Guide to Insider Threats: Lessons from Past Mistakes
Insider threats are perhaps the most serious challenges that nuclear security systems face. All of the cases of theft of nuclear materials where the circumstances of the theft are known were perpetrated either by insiders or with the help of insiders; given that the other cases involve bulk material stolen covertly without anyone being aware the material was missing, there is every reason to believe that they were perpetrated by insiders as well. Similarly, disgruntled workers from inside nuclear facilities have perpetrated many of the known incidents of nuclear sabotage. The most recent example of which we are aware is the apparent insider sabotage of a diesel generator at the San Onofre nuclear plant in the United States in 2012; the most spectacular was an incident three decades ago in which an insider placed explosives directly on the steel pressure vessel head of a nuclear reactor and then detonated them.While many such incidents, including the two just mentioned, appear to have been intended to send a message to management, not to spread radioactivity, they highlight the immense dangers that could arise from insiders with more malevolent intent. As it turns out, insiders perpetrate a large fraction of thefts from heavily guarded non-nuclear facilities as well. Yet organizations often find it difficult to understandand protect against insider threats. Why is this the case?Part of the answer is that there are deep organizational and cognitive biases that lead managers to downplay the threats insiders pose to their nuclear facilities and operations. But another part of the answer is that those managing nuclear security often have limited information about incidents that have happened in other countries or in other industries, and the lessons that might be learned from them.The IAEA and the World Institute for Nuclear Security (WINS) produce"best practices" guides as a way of disseminating ideas and procedures that have been identified as leading to improved security. Both have produced guides on protecting against insider threats.5 But sometimes mistakes are even moreinstructive than successes.Here, we are presenting a kind of "worst practices" guide of serious mistakes made in the past regarding insider threats. While each situation is unique, and serious insider problems are relatively rare, the incidents we describe reflect issues that exist in many contexts and that every nuclear security manager should consider. Common organizational practices -- such as prioritizing production over security, failure to share information across subunits, inadequate rules or inappropriate waiving of rules, exaggerated faith in group loyalty, and excessive focus on external threats -- can be seen in many past failures to protect against insider threats
Kettles of hawks: public opinion on the nuclear taboo and noncombatant immunity in the United States, United Kingdom, France, and Israel
Recent scholarship has established that a majority of Americans will support the use of nuclear weapons and violate the principle of noncombatant immunity when American lives are on the line. Some scholars contend, however, that these hawkish American attitudes are an outlier and that other Western democratic publics have more fully internalized the nuclear taboo, as well as the prohibition on deliberately killing civilians. To investigate cross-national attitudes on these important norms, we conducted a survey experiment of American, British, French, and Israeli citizens. We find that American attitudes are not exceptional. Rather, Israeli respondents display the most hawkish preferences; French and American citizens are roughly equally hawkish; and the British public is consistently the least supportive of nuclear use or targeting civilians. Categorical prohibitions—against nuclear use and targeting civilians—do little to shape public opinion in these four countries. Instead, public opinion in each state follows the same consequentialist logic: a majority or near majority of respondents are willing to support using nuclear weapons when they are more effective than conventional options, but support declines when collateral civilian deaths rise. Respondents’ preferences for compatriots over foreign civilians and respondents’ retributiveness help explain individual-level variation in attitudes
Shared Responsibilities for Nuclear Disarmament: A Global Debate
Presents Sagan's 2009 paper calling for rethinking the balance of responsibilities and the relationship between articles in the Nuclear Non-Proliferation Treaty with seven response papers by international scholars about how to pursue nuclear disarmament
Induction of Paralysis and Visual System Injury in Mice by T Cells Specific for Neuromyelitis Optica Autoantigen Aquaporin-4.
While it is recognized that aquaporin-4 (AQP4)-specific T cells and antibodies participate in the pathogenesis of neuromyelitis optica (NMO), a human central nervous system (CNS) autoimmune demyelinating disease, creation of an AQP4-targeted model with both clinical and histologic manifestations of CNS autoimmunity has proven challenging. Immunization of wild-type (WT) mice with AQP4 peptides elicited T cell proliferation, although those T cells could not transfer disease to naïve recipient mice. Recently, two novel AQP4 T cell epitopes, peptide (p) 135-153 and p201-220, were identified when studying immune responses to AQP4 in AQP4-deficient (AQP4-/-) mice, suggesting T cell reactivity to these epitopes is normally controlled by thymic negative selection. AQP4-/- Th17 polarized T cells primed to either p135-153 or p201-220 induced paralysis in recipient WT mice, that was associated with predominantly leptomeningeal inflammation of the spinal cord and optic nerves. Inflammation surrounding optic nerves and involvement of the inner retinal layers (IRL) were manifested by changes in serial optical coherence tomography (OCT). Here, we illustrate the approaches used to create this new in vivo model of AQP4-targeted CNS autoimmunity (ATCA), which can now be employed to study mechanisms that permit development of pathogenic AQP4-specific T cells and how they may cooperate with B cells in NMO pathogenesis
Isochoric thermal conductivity of solid nitrogen
The isochoric thermal conductivity of solid nitrogen has been investigated on
four samples of different densities in the temperature interval from 20 K to
the onset of melting. In alfa-N2 the isochoric thermal conductivity exhibits a
dependence weaker than 1/T; in beta-N2 it increases slightly with temperature.
The experimental results are discussed within a model in which the heat is
transported by low-frequency phonons or by "diffusive" modes above the mobility
boundary. The growth of the thermal conductivity in beta-N2 is attributed to
the decreasing "rotational" component of the total thermal resistance, which
occurs as the rotational correlations between the neighboring molecules become
weaker.Comment: Postscript 12 pages, 3 figures, 1 table. To be published in 200
Mechanisms for the formation of benzene in the atmosphere of Titan
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95336/1/jgre1586.pd
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