Modelling wave-induced sea ice breakup in the marginal ice zone

A model of ice floe breakup under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave breakup events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a breakup criterion. A closed-feedback loop algorithm is devised, which (i)~solves wave scattering problem for a given FSD under time-harmonic plane wave forcing, (ii)~computes the stress field in all the floes, (iii)~fractures the floes satisfying the breakup criterion and (iv)~generates an updated FSD, initialising the geometry for the next iteration of the loop.The FSD after 50 breakup events is uni-modal and near normal, or bi-modal. Multiple scattering is found to enhance breakup for long waves and thin ice, but to reduce breakup for short waves and thick ice. A breakup front marches forward in the latter regime, as wave-induced fracture weakens the ice cover allowing waves to travel deeper into the MIZ.Comment: 32 pages, 11 figure

Augmentation of Mind-body Therapy and Role of Deep Slow Breathing

Mind-body therapies have been shown to be effective in clinical treatment of disorders such as high blood pressure and stress. Significant differences in the effectiveness of mind–body therapies have been shown and a common link among the therapies has yet to be defined. This article overviews the role of slow rhythmic breathing in physiological as well as therapeutic effects of mind-body therapies. Slow deep breathing practice has important implications as it may underlie the basic mechanism that synchronizes the brain with the autonomic response. This article reviews studies that include the effect of deep slow breathing with or without mind-body therapy exercises. In utero studies that monitor patterns of fetal breathing reveal sympathetic activation with irregular, shallow fast breathing movements compared to slow deep breathing. Recognition of respiratory mechanisms in mind-body therapies can lead to development of more effective relaxation exercises that may incorporate deep slow breathing in clinical applications

Evaluation of the NAS-ILAB Matrix for Monitoring International Labor Standards: Project Report

The Bureau of International Labor Affairs (ILAB) engaged the National Research Council of the National Academy of Sciences (NAS) to recommend a method to monitor and evaluate labor conditions in a given country. The method focuses on 5 labor standards: freedom of association and collective bargaining, forced or compulsory labor, child labor, discrimination, and acceptable conditions of work

The Cost of US Pharmaceutical Price Reductions: A Financial Simulation Model of R&D Decisions

Previous empirical studies that have examined the links between pharmaceutical price controls, profits, cash flows, and investment in research and development (R&D) have been largely based on retrospective statistical analyses of firm- and/or industry-level data. These studies, which have contributed numerous insights and findings to the literature, relied upon ad hoc reduced-form model specifications. In the current paper we take a very different approach: a prospective micro-simulation approach. Using Monte Carlo techniques we model how future price controls in the U.S. will impact early-stage product development decisions in the pharmaceutical industry. This is done within the context of a net present value (NPV) framework that appropriately reflects the uncertainty associated with R&D project technical success, development costs, and future revenues. Using partial-information estimators calibrated with the most contemporary clinical and economic data available, we demonstrate how pharmaceutical price controls will significantly diminish the incentives to undertake early-stage R&D investment. For example, we estimate that cutting prices by 40 to 50 percent in the U.S. will lead to between 30 to 60 percent fewer R&D projects being undertaken (in early-stage development). Given the recent legislative efforts to control prescription drug prices in the U.S., and the likelihood that price controls will prevail as a result, it is important to better understand the firm response to such a regulatory change.

The Future of Drug Development: The Economics of Pharmacogenomics

This paper models how the evolving field of pharmacogenomics (PG), which is the science of using genomic markers to predict drug response, may impact drug development times, attrition rates, costs, and the future returns to research and development (R&D). While there still remains an abundance of uncertainty around how PG will impact the future landscape of pharmaceutical and biological R&D, we identify several likely outcomes. We conclude PG has the potential to significantly reduce both expected drug development costs (via higher probabilities of technical success, shorter clinical development times, and smaller clinical trials) and returns. The impact PG has on expected returns is partially mitigated by higher equilibrium prices, expedited product launches, and longer effective patent lives. Our conclusions are, of course, accompanied by numerous caveats.

Financial Risk in the Biotechnology Industry

The biotechnology industry has been an engine of innovation for the U.S. healthcare system and, more generally, the U.S. economy. It is by far the most research intensive industry in the U.S. In our analyses in the current paper, for example, we find that, over the past 25 years, average R&D intensity (R&D spending to total firm assets) for this industry was 38 percent. Consider that over this same period average R&D intensity for all industries was only about 3 percent. In the current paper we examine this industry along a number of dimensions and estimate its average financial risk. Specifically, we use Compustat and Center for Research in Securities Prices (CRSP) data from 1982 to 2005 for firms defined by the North American Industry Classification System (NAICS) as biotechnology firms to estimate several Fama-French three factor return models. The finance literature has established this model as the gold standard. Single factor models like the Capital Asset Pricing Model (CAPM) do not capture all of the types of systematic risk that influence firm cost of capital. In particular, the CAPM does not reflect the empirical evidence that supports both a size-related and a book-to-market related systematic risk factor . Both of these factors, based on biotech industry characteristics, will exert a greater influence on biotech firms, on average. Another implication is, of course, that cost of capital estimates for the industry will be underestimated when a single factor model, like the CAPM, is used. This also implies that the cost estimates of bringing a new drug and/or biologic to market will be understated if financial risk and cost of capital are measured using a single-factor model. In the current study we find that biotechnology firms are exposed to greater financial risk than other industries and are also more sensitive to policy shocks that affect, or could affect, industry profitability. Average nominal costs of capital over the 1982-2005 time period were 16.25 percent for biotechnology firms. Of course, these average estimates obscure significant variation in financial risk at the firm level, but nonetheless shed light on some interesting aggregate differences in risk. In the current paper we discuss the theoretical links between financial risk, stock prices and returns, and R&D spending. Several caveats are also discussed.

Apollo experience report: Guidance and control systems; lunar module mission programer

A review of the concept, operational requirements, design, and development of the lunar module mission programer is presented, followed by a review of component and subsystem performance during design-feasibility, design-verification, and qualification tests performed in the laboratory. The system was further proved on the unmanned Apollo 5 mission. Several anomalies were detected, and satisfactory solutions were found. These problems are defined and examined, and the corrective action taken is discussed. Suggestions are given for procedural changes to be used if future guidance and control systems of this type are to be developed

THE DEFICIT IN NATURAL RESOURCE RESEARCH

Resource /Energy Economics and Policy,