Measurement of the threshold sensitivity of honeybees to weak, extremely low-frequency magnetic fields

Experiments reported previously demonstrate that free-flying honeybees are able to detect static intensity fluctuations as weak as 26 nT against the background, earth-strength magnetic field. We report here an extension of this work to weak, alternating fields at frequencies of 10 and 60 Hz. Our results indicate that the sensitivity of the honeybee magnetoreception system decreases rapidly with increasing frequency. At 60 Hz, alternating field strengths above 100 µT are required to elicit discrimination. These results are consistent with biophysical predictions of a magnetite-based magnetoreceptor

Statistical simulation procedures

Statistical simulation procedures utilizing Monte Carlo stratification techniqu

Barry Saltzman and the Theory of Climate

Barry Saltzman was a giant in the fields of meteorology and climate science. A leading figure in the study of weather and climate for over 40 yr, he has frequently been referred to as the father of modern climate theory. Ahead of his time in many ways, Saltzman made significant contributions to our understanding of the general circulation and spectral energetics budget of the atmosphere, as well as climate change across a wide spectrum of time scales. In his endeavor to develop a unified theory of how the climate system works, lie played a role in the development of energy balance models, statistical dynamical models, and paleoclimate dynamical models. He was a pioneer in developing meteorologically motivated dynamical systems, including the progenitor of Lorenz\u27s famous chaos model. In applying his own dynamical-systems approach to long-term climate change, he recognized the potential for using atmospheric general circulation models in a complimentary way. In 1998, he was awarded the Carl-Gustaf Rossby medal, the highest honor of the American Meteorological Society for his life-long contributions to the study of the global circulation and the evolution of the earth\u27s climate. In this paper, the authors summarize and place into perspective some of the most significant contributions that Barry Saltzman made during his long and distinguished career. This short review also serves as an introduction to the papers in this special issue of the Journal of Climate dedicated to Barry\u27s memory

Interactive, Mixed-integer Goal Programming Application of Capital Budgeting at Cities Service Company

This study presents the development and implementation of a mixed-integer goal programming model to assist Cities Service management in strategic capital budgeting. Two types of input to the model were: 1. Corporate information and paramaters - provided by corporate management; and 2. Strategic Planning Unit scenario information - provided by the unique corporate segments within Cities Service. Given these inputs the desired output was an analysis of corporate direction via annual statistics in areas such as new debt issued and investments using the optimal scenario per strategic planning unit to maximize various corporate goals. A branch and bound algorithm was developed to assist in choosing the single scenario per strategic planning unit. All equations were linear in the model. Six programs were developed and linked together in an interactive environment to produce corporate statistics over a ten year horizon. The third of these programs was an existing goal program. This program was combined with a branch and bound program, also developed, to produce the required mixed-integer solutions. Another output of the system was a report analyzing goal achievement. Four goals were allowed per run for which weights, priorities, and actual target values must be entered. The areas allowed as goals were net income, growth,return on assets, and assets. As described, the inputs and outputs are especially tailored to meet Cities Service Company's specific capital budgeting information requirements. Though conversion pn the optimal solution was not attained as quickly as desired, various running options provided management with ample flexibility and convenience to meet their specifications.Business Administratio

Experimental investigation of strong ground motion due to thrust fault earthquakes

Thrust fault earthquakes are studied in a laboratory earthquake setup previously used to investigate analog strike-slip seismic events. Dynamic mode II ruptures are generated along preexisting faults in an analog material, Homalite H-100, and their interaction with the free surface is studied for both sub-Rayleigh and supershear rupture speeds. High-speed digital photography and laser velocimeter diagnostics are used synergistically to identify and study the ground velocity signatures caused by the various features of the generated ruptures. The obtained surface-normal motions of both sub-Rayleigh and supershear ruptures show substantial asymmetry between the hanging and footwall, with the hanging wall experiencing much larger velocity amplitudes. The main features of the surface velocity traces at various stations can be explained by the calculated arrivals of various waves and fronts—Mach cones, Pand S waves, and sub-Rayleigh features. In both the sub-Rayleigh and supershear cases, the arrival of the rupture tip generates a prominent Rayleigh wave traveling along the simulated Earth's surface. Supershear events feature larger amplitudes of ground shaking profiles. All signatures in the surface motion records attenuate and broaden with increasing distance from the fault trace. The signatures corresponding to the arrival of the Mach fronts attenuate with distance at a slower rate than those from sub-Rayleigh ruptures. The arrival of the updip supershear rupture at the free surface creates a downdip propagating slip feature with its own Mach cone. These additional Mach fronts further amplify ground shaking on the hanging and footwalls

Understanding and Assessing Climate Change: Implications for Nebraska

This report was commissioned by the UNL Institute of Agriculture and Natural Resources (IANR) with the objective of evaluating and summarizing the existing scientific literature related to our changing climate. Scientists from the IANR’s School of Natural Resources and the Department of Earth and Atmospheric Sciences in the College of Arts and Sciences have been the principal contributors to the report under the able leadership of long-time, internationally leading applied climate scientist Professor Don Wilhite. Their efforts have resulted in a timely and seminal reference for state and local policy-makers, government agency leaders, private industry, and indeed all citizens of our great state. Globally, we face significant economic, social, and environmental risks as we confront the challenges associated with climate change. The body of scientific evidence confirms with a high degree of certainty that human activities in the form of increased concentrations of greenhouse gases (GHGs) since the beginning of the Industrial Revolution, changes in land use, and other factors are the primary cause for the warming that the planet has experienced, especially in recent decades. Is there a debate within the scientific community with regard to observed changes in climate and human activities as the principal causal factor? The short answer here is “no”, at least certainly not among climate scientists—that is, those scientists who have actual expertise in the study of climate and climate change. For more than a decade, there has been broad and overwhelming consensus within the climate science community that the human-induced effects on climate change are both very real and very large. The debate in 2014 is restricted to precisely how these changes will play out and what actions we will need to take to adapt to and mitigate the effects of these changes. The magnitude and rapidity of the projected changes in climate are unprecedented. The implications of these changes for the health of our planet, and the legacy we will leave to our children, our grandchildren and future generations are of vital concern. Therefore, it is imperative that we develop strategies now to adapt to the multitude of changes we are experiencing and will continue to experience in our climate. This process of adaptation must begin at the local level, where these changes are being observed and their impacts felt. However, global agreements on the reduction of GHG emissions are a critical part of the solution in terms of mitigating as much future warming as possible. The approach taken in this report is to review the voluminous scientific literature on the subject and interpret—given time and resource constraints—our current understanding of the science of climate change and the implications of projections of climate change for Nebraska. The goal of this report is to inform policy makers, natural resource managers, and the public about 1) the state of the science on climate change, 2) current projections for ongoing changes over the twenty-first century, 3) current and potential future impacts, and 4) the management and policy implications of these changes. Hopefully, this report will lead to a higher degree of awareness and the initiation of timely and appropriate strategic actions that enable Nebraskans to prepare for and adapt to current and future changes in our climate