7,800 research outputs found
Intersection theory on moduli spaces of holomorphic bundles of arbitrary rank on a Riemann surface
We prove formulas (found by Witten in 1992 using physical methods) for
intersection pairings in the cohomology of the moduli space M(n,d) of stable
holomorphic vector bundles of rank n and degree d (assumed coprime) on a
Riemann surface of genus g greater than or equal to 2. We also use these
formulas for intersection numbers to obtain a proof of the Verlinde formula for
the dimension of the space of holomorphic sections of a line bundle over
M(n,d).Comment: 77 pages, LaTeX version 2.09. This is the text of the revised version
which will appear in Annals of Mathematics. An error in Section 2 of the
previous version has been correcte
The Role of Transportation in Campus Emergency Planning, MTI Report 08-06
In 2005, Hurricane Katrina created the greatest natural disaster in American history. The states of Louisiana, Mississippi and Alabama sustained significant damage, including 31 colleges and universities. Other institutions of higher education, most notably Louisiana State University (LSU), became resources to the disaster area. This is just one of the many examples of disaster impacts on institutions of higher education. The Federal Department of Homeland Security, under Homeland Security Presidential Directive–5, requires all public agencies that want to receive federal preparedness assistance to comply with the National Incident Management System (NIMS), which includes the creation of an Emergency Operations Plan (EOP). Universities, which may be victims or resources during disasters, must write NIMS–compliant emergency plans. While most university emergency plans address public safety and logistics management, few adequately address the transportation aspects of disaster response and recovery. This MTI report describes the value of integrating transportation infrastructure into the campus emergency plan, including planning for helicopter operations. It offers a list of materials that can be used to educate and inform campus leadership on campus emergency impacts, including books about the Katrina response by LSU and Tulane Hospital, contained in the report´s bibliography. It provides a complete set of Emergency Operations Plan checklists and organization charts updated to acknowledge lessons learned from Katrina, 9/11 and other wide–scale emergencies. Campus emergency planners can quickly update their existing emergency management documents by integrating selected annexes and elements, or create new NIMS–compliant plans by adapting the complete set of annexes to their university´s structures
Great East Japan Earthquake, JR East Mitigation Successes, and Lessons for California High-Speed Rail, MTI Report 12-37
California and Japan both experience frequent seismic activity, which is often damaging to infrastructure. Seismologists have developed systems for detecting and analyzing earthquakes in real-time. JR East has developed systems to mitigate the damage to their facilities and personnel, including an early earthquake detection system, retrofitting of existing facilities for seismic safety, development of more seismically resistant designs for new facilities, and earthquake response training and exercises for staff members. These systems demonstrated their value in the Great East Japan Earthquake of 2011 and have been further developed based on that experience. Researchers in California are developing an earthquake early warning system for the state, and the private sector has seismic sensors in place. These technologies could contribute to the safety of the California High-Speed Rail Authority’s developing system, which could emulate the best practices demonstrated in Japan in the construction of the Los Angeles-to-San Jose segment
Recommended from our members
Using remarkability to define coastal flooding thresholds.
Coastal flooding is increasingly common in many areas. However, the degree of inundation and associated disruption depend on local topography as well as the distribution of people, infrastructure and economic activity along the coast. Local measures of flooding that are comparable over large areas are difficult to obtain. Here we use the remarkability of flood events, measured by flood-related posts on social media, to estimate county-specific flood thresholds for shoreline counties along the east coast of the United States. While thresholds in most counties are statistically-indistinguishable from minor flood thresholds of nearby tide gauges, we find evidence that several areas experience noticeable flooding at tide heights lower than existing flood thresholds. These 22 counties include several major cities such as Miami, New York, and Boston, with a total population over 13 million. Our analysis implies that large populations might currently be exposed to nuisance flooding not identified via standard measures
Catalysts on Demand: Selective Oxidations by Laboratory-Evolved Cytochrome P450 BM3
Efficient catalysts for selective oxidation of C-H bonds using atmospheric oxygen are highly desirable to decrease the economic and environmental costs associated with conventional oxidation processes. We have used methods of directed evolution to generate variants of bacterial cytochrome P450 BM3 that catalyze hydroxylation and epoxidation of a wide range of nonnative substrates. This fatty acid hydroxylase was converted to a propane monooxygenase (PMO) capable of hydroxylating propane at rates comparable to that of BM3 on its natural substrates. Variants along the PMO evolutionary lineage showed broadened substrate scope; these became the starting points for evolution of a wide array of enzymes that can hydroxylate and derivatize organic scaffolds. This work demonstrates how a single member of enzyme family is readily converted by evolution into a whole family of catalysts for organic synthesis
Handbook of Emergency Management For State-Level Transportation Agencies, MTI Report 09-10
The Department of Homeland Security has mandated specific systems and techniques for the management of emergencies in the United States, including the Incident Command System, the National Incident Management System, Emergency Operations Plans, Emergency Operations Centers, Continuity of Government Plans and Continuity of Operations Plans. These plans and systems may be applied to the state-level transportation agency�s disaster response systems to enhance efficiency and effectiveness. Specific guidance and management techniques are provided to aid emergency planning staff to create DHS-compliant systems
- …