The clinical epidemiology of hysteria: vanishingly rare, or just vanishing?

Vanish 1. intr. To disappear from sight or become invisible, esp. in a rapid and mysterious way (Shorter Oxford English Dictionary, 1972). There is a well-known view that hysteria has virtually disappeared in the Western world. There are two versions of this argument: one is that there was never a clinical disorder that coincided with the diagnosis, and hysteria has now been reconstructed as something else (e.g. Micale, 1993). The other is that hysteria did exist but has now become much rarer than it was (most famously, Veith, 1965). According to this view, hysteria is to be found in patients from developing countries, but in Western countries it is ‘virtually a historical curiosity’ (BMJ 1976). It is the latter view that is – in our experience – most commonly held by our colleagues in general psychiatry. Yet, this opinion is not shared by those who are involved in the clinical care of patients with neurological disorders: ‘to a psychiatrist who sees patients on the medical and surgical services of a general hospital, it appears that hysteria remains a rather common phenomenon’ (Brownsberger, 1966). A number of descriptions from liaison psychiatry services support this opinion (Akagi & House, 2001). There are good reasons why it might be difficult to judge just how common (or rare) hysteria really is. Epidemiology depends on reliable case definition, case ascertainment and selection of a suitable population to study (Neugebauer et al. 1980), and each of these poses problems in the study of hysterical disorders

A Method for the Perceptual Optimization of Complex Visualizations

A common problem in visualization applications is the display of one surface overlying another. Unfortunately, it is extremely difficult to do this clearly and effectively. Stereoscopic viewing can help, but in order for us to be able to see both surfaces simultaneously, they must be textured, and the top surface must be made partially transparent. There is also abundant evidence that all textures are not equal in helping to reveal surface shape, but there are no general guidelines describing the best set of textures to be used in this way. What makes the problem difficult to perceptually optimize is that there are a great many variables involved. Both foreground and background textures must be specified in terms of their component colors, texture element shapes, distributions, and sizes. Also to be specified is the degree of transparency for the foreground texture components. Here we report on a novel approach to creating perceptually optimal solutions to complex visualization problems and we apply it to the overlapping surface problem as a test case. Our approach is a three-stage process. In the first stage we create a parameterized method for specifying a foreground and background pair of textures. In the second stage a genetic algorithm is applied to a population of texture pairs using subject judgments as a selection criterion. Over many trials effective texture pairs evolve. The third stage involves characterizing and generalizing the examples of effective textures. We detail this process and present some early results

Fillers for improved graphite fiber retention by polymer matrix composites

The results of a program designed to determine the extent to which elemental boron and boron containing fillers added to the matrix resin of graphite/epoxy composites prevent the release of graphite fibers when the composites are exposed to fire and impact conditions are described. The fillers evaluated were boron, boron carbide and aluminum boride. The conditions evaluated were laboratory simulations of those that could exist in the event of an aircraft crash and burn situation. The baseline (i.e., unfilled) laminates evaluated were prepared from commercially available graphite/epoxy. The baseline and filled laminates' mechanical properties, before and after isothermal and humidity aging, also were compared. It was found that a small amount of graphite fiber was released from the baseline graphite/epoxy laminates during the burn and impact conditions used in this program. However, the extent to which the fibers were released is not considered a severe enough problem to preclude the use of graphite reinforced composites in civil aircraft structure. It also was found that the addition of boron and boron containing fillers to the resin matrix eliminated this fiber release. Mechanical properties of laminates containing the boron and boron containing fillers were lower than those of the baseline laminates. These property degradations for two systems: boron (5 micron) at 2.5 percent filler loading, and boron (5 micron) at 5.0 percent filler loading do not appear severe enough to preclude their use in structural composite applications

On the Optimization of Visualizations of Complex Phenomena

The problem of perceptually optimizing complex visualizations is a difficult one, involving perceptual as well as aesthetic issues. In our experience, controlled experiments are quite limited in their ability to uncover interrelationships among visualization parameters, and thus may not be the most useful way to develop rules-of-thumb or theory to guide the production of high-quality visualizations. In this paper, we propose a new experimental approach to optimizing visualization quality that integrates some of the strong points of controlled experiments with methods more suited to investigating complex highly-coupled phenomena. We use human-in-the-loop experiments to search through visualization parameter space, generating large databases of rated visualization solutions. This is followed by data mining to extract results such as exemplar visualizations, guidelines for producing visualizations, and hypotheses about strategies leading to strong visualizations. The approach can easily address both perceptual and aesthetic concerns, and can handle complex parameter interactions. We suggest a genetic algorithm as a valuable way of guiding the human-in-the-loop search through visualization parameter space. We describe our methods for using clustering, histogramming, principal component analysis, and neural networks for data mining. The experimental approach is illustrated with a study of the problem of optimal texturing for viewing layered surfaces so that both surfaces are maximally observable

X-ray diffraction analysis of Nb-3Ge and NbGe alloys

Of all the A-15 samples of NbGe alloy examined, DT 094 is unique in that it was at least 99% pure A-15 phase. Also its diffraction peaks were noisy as if there were about a one percent compositional variation on this phase. DT 094, however, was only a large fragment of the drop tube drop, and thus its small sample size may have reduced the intensity, thus enhancing fluctuations enough to explain some of the loss of peak resolution

Analysis of the U.S.-Mexico Sugar Trade - 10 Years of NAFTA Regime and 10 Years from Now

The U.S.- Mexico sugar trade was examined, paying a close attention to the provisions of North American Free Trade Agreement (NAFTA) and the circumstances surrounding the industries of the two countries. Quantitative analyses provided the outlook of the future sugar market and shed light on the political implications.International Relations/Trade,

A MODEL OF ENTRY-EXIT DECISIONS AND CAPACITY CHOICE UNDER DEMAND UNCERTAINTY

Many investment decisions of agribusiness firms such as when to invest in an emerging market or whether to expand the capacity of the firm involve irreversible investment and uncertainty about demand, cost or competition. This paper uses an option-value model to examine the factors affecting an agribusiness firm's decision whether and how much to invest in an emerging market under demand uncertainty. Demand uncertainty and irreversibility of investment make investment less desirable than the net present value (NPV) rule indicates. The inactive firm is more reluctant to enter the market when it takes into account demand uncertainty because it preserves the opportunity of making a better investment later. The active firm is more reluctant to abandon the investment because there is an option value of keeping the operation alive. There is a greater distance between the entry and exit thresholds under the option-value approach than under the NPV rule due to demand uncertainty. The results have implications for agribusiness decision-making to understand and respond to uncertainty.agribusiness decision-making, demand uncertainty, entry-exit decisions, net present value, real options, remote sensing, Demand and Price Analysis,

Regional Data in Historic Archeology: Examples from Environmental Impact Surveys

The emphasis on regional vs. single site data in prehistoric archeology is related to the assumption that culture is an adaptive behavioral system articulated with the natural and social environments. The testing of hypotheses and models about the nature of past societies in the historic period likewise requires regional data, not all of which may be available in the historical record. Archeological survey data--including those generated by Environmental Impact studies and other specific contract research--may be relevant to measuring cultural variables of historic period societies on a regional basis. Location, variability, and density of sites are some aspects of the historic archeological record which are especially amenable to measurement using survey data. Some examples of these aspects, derived from recent contract work in Arkansas and Missouri are discussed.https://scholarcommons.sc.edu/archanth_books/1075/thumbnail.jp