Resilience–Recovery Factors in Post-traumatic Stress Disorder Among Female and Male Vietnam Veterans: Hardiness, Postwar Social Support, and Additional Stressful Life Events

Structural equation modeling procedures were used to examine relationships among several war zone stressor dimensions, resilience-recovery factors, and post-traumatic stress disorder symptoms in a national sample of 1,632 Vietnam veterans (26% women and 74% men). A 9-factor measurement model was specified on a mixed-gender subsample of the data and then replicated on separate subsamples of female and male veterans. For both genders, the structural models supported strong mediation effects for the intrapersonal resource characteristic of hardiness, postwar structural and functional social support, and additional negative life events in the postwar period. Support for moderator effects or buffering in terms of interactions between war zone stressor level and resiliencerecovery factors was minimal

Industry-Science Connections in Agriculture: Do public science collaborations and knowledge flows contribute to firm-level agricultural research productivity?

Prior research identifies a direct positive link between the stock of public scientific knowledge and agricultural productivity; however, an indirect contribution to agricultural productivity is also possible when this stock facilitates private sector invention. This study examines how “connectedness” between the stock of public scientific knowledge and private firms influences firm-level research productivity. Bibliographic information identifies the nature and degree to which firms use public agricultural science through citations and collaborations on scientific papers. Fixed effects models show that greater citations and collaborations with university researchers are associated with greater agricultural research productivity.public science, research productivity, patents, citations, collaboration, R&D, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies, Q16, O31,

Static and Dynamic Resource Allocation Effects of Corporate and PersonalTax Integration in the U.S.: A General Equilibrium Approach(Rev)

This paper presents estimates of static and dynamic general equilibrium resource allocation effects for four alternative plans for corporate and personal income tax integration in the U.S. A medium—scale numerical general equilibrium model is used which integrates the U.S. tax system with consumer demand behavior by household and producer behavior by industry. Results indicate that total integration of personal and corporate taxes would yield an annual static efficiency gain of around $4 billion (1973 dollars). Partial integration plans yield less. Dynamic effects are larger, and our analysis indicates that full integration may yield gains whose present value is as large as$400 billion or 0.8% of the discounted present value of the GNP stream to the U.S. economy after correction for population growth. Plans differ in their distributional impacts, although these findings depend on the nature of replacement taxes used to preserve government revenues. The size of dynamic resource allocation effects are sensitive to the choice of the replacement tax, while static gains are reasonably robust.

POTENTIAL PITFALLS IN RENEWABLE RESOURCE DECISION MAKING THAT UTILIZES CONVEX COMBINATIONS OF DISCRETE ALTERNATIVES

Decision makers in renewable resource planning are often unable to specify their objective function a priori, and are presented with a discrete set of alternatives reflecting a range of options that are actually much more continuous. It is common for the decision maker to be interested in some other alternative than those originally developed. An iterative process thus often takes place between decision maker an analyst as they search for a satisfactory alternative. This paper analyzes the economic tenability of simply interpolating (taking convex combinations of) initial alternatives to generate new alternatives in this process. It is shown that convex combinations of outputs will be producible (feasible) with the interpolated input levels, under very common conditions. In fact, the cost estimate resulting from interpolating the cost of two (or more) alternatives will generally be an overestimate. The magnitude of this overestimate is investigated in a test case. It is concluded that this cost overestimate can be rather large, and is not systematically predictable. Only when the output sets in the original alternatives are very similar are the interpolated cost estimates fairly accurate.Resource /Energy Economics and Policy,

GOVERNMENT PATENTING AND TECHNOLOGY TRANSFER

Intellectual property rights such as patents protect new inventions from imitation and competition. Patents' major objective is to provide incentives for invention, sacrificing short-term market efficiency for long-term economic gains. Although patents are primarily granted to private firms, policy changes over the last 25 years have resulted in greater use of patenting by the public sector. This study examines government patenting behavior by analyzing case studies of patenting and licensing by the Agricultural Research Service (ARS) of the U.S. Department of Agriculture. ARS uses patenting and licensing as a means of technology transfer in cases in which a technology requires additional development by a private sector partner to yield a marketable product. Licensing revenue is not a major motivation for ARS patenting. More widespread use of patenting and licensing by ARS has not reduced the use of traditional instruments of technology transfer such as scientific publication. Once the decision has been made to patent and license a technology, the structure of the licensing agreement affects technology transfer outcomes. As commercial partners gain experience with the technology and learn more about the market, mutually advantageous revisions to license terms can maintain the incentives through which private companies distribute the benefits of public research.patents, licenses, intellectual property rights, technology transfer, Agricultural Research Service, agricultural research and development, Research and Development/Tech Change/Emerging Technologies,

The tension between fire risk and carbon storage: evaluating U.S. carbon and fire management strategies through ecosystem models

Fire risk and carbon storage are related environmental issues because fire reduction results in carbon storage through the buildup of woody vegetation, and stored carbon is a fuel for fires. The sustainability of the U.S. carbon sink and the extent of fire activity in the next 100 yr depend in part on the type and effectiveness of fire reduction employed. Previous studies have bracketed the range of dynamics from continued fire reduction to the complete failure of fire reduction activities. To improve these estimates, it is necessary to explicitly account for fire reduction in terrestrial models. A new fire reduction submodel that estimates the spatiotemporal pattern of reduction across the United States was developed using gridded data on biomass, climate, land-use, population, and economic factors. To the authors’ knowledge, it is the first large-scale, gridded fire model that explicitly accounts for fire reduction. The model was calibrated to 1° × 1° burned area statistics [Global Burnt Area 2000 Project (GBA-2000)] and compared favorably to three important diagnostics. The model was then implemented in a spatially explicit ecosystem model and used to analyze 1620 scenarios of future fire risk and fire reduction strategies. Under scenarios of climate change and urbanization, burned area and carbon emissions both increased in scenarios where fire reduction efforts were not adjusted to match new patterns of fire risk. Fuel reducing management strategies reduced burned area and fire risk, but also limited carbon storage. These results suggest that to promote carbon storage and minimize fire risk in the future, fire reduction efforts will need to be increased and spatially adjusted and will need to employ a mixture of fuel-reducing and non-fuel-reducing strategies

Gas Concentration Measurements in Underground Waste Storage Tanks

Currently over 100 underground tanks at the Hanford facility in eastern Washington state are being used to store high-level radioactive waste. With plans for a long-term nuclear-waste repository in Nevada in place (though not yet approved), one promising use for these underground storage tanks is as a temporary waystation for waste destined for the Nevada repository. However, without a reasonable understanding of the chemical reactions going on within the tanks, transporting waste in and out of the tanks has been deemed to be unsafe. One hazard associated with such storage mechanisms is explosion of flammable gases produced within the tank. Within many of the storage tanks is a sludge layer. This layer, which is a mixture of liquid and solids, contains most of the radioactive material. Radioactive decay and its associated heat can produce several flammable materials within this layer. Two components of particular concern are hydrogen (H2) and nitrous oxide (N2O), since they are highly volatile in the gaseous phase. Though the tanks have either forced or natural convection systems to vent these gases, the possibility of an explosion still exists. Measurements of these gases are taken in several ways. Continuous measurements are taken in the headspace, which is the layer between the tank ceiling and the liquid (supernatant) or sludge layer below. In tanks where a supernatant layer sits atop the sludge layer, there are often rollovers or gas release events (GREs), where a large chunk of sludge, after attaining a certain void fraction, becomes buoyant, rising through the supernatant and releasing its associated gas composition to the headspace. Such changes trigger a sensor, and thus measurements are also taken at that time. Lastly, a retained gas sample (RGS) can be taken from either the supernatant or sludge layer. Such a core sample is quite expensive, but can yield crucial data about the way gases are being produced in the sludge and convected through the supernatant. Unfortunately, the measurements from these three populations do not seem to match. In particular, the ratio r = [N2O]/[H2] varies from population to population. r also varies from tank to tank, but this can more readily be explained in terms of the waste composition of each tank. Since H2 is more volatile than N2O (and since there are more sources of oxygen in the headspace), lower values of r correspond to more hazardous situations. This variance in r is troubling, since we need to be able to explain why certain values of r are lower (and hence more dangerous) in certain areas of the tank. In this report we examine the data from three tanks. We first verify that the differences in r among populations is significant. We then postulate several mechanisms which could explain such a difference

Establishing the boundaries: the hippocampal contribution to imagining scenes

When we visualize scenes, either from our own past or invented, we impose a viewpoint for our “mind's eye” and we experience the resulting image as spatially coherent from that viewpoint. The hippocampus has been implicated in this process, but its precise contribution is unknown. We tested a specific hypothesis based on the spatial firing properties of neurons in the hippocampal formation of rats, that this region supports the construction of spatially coherent mental images by representing the locations of the environmental boundaries surrounding our viewpoint. Using functional magnetic resonance imaging, we show that hippocampal activation increases parametrically with the number of enclosing boundaries in the imagined scene. In contrast, hippocampal activity is not modulated by a nonspatial manipulation of scene complexity nor to increasing difficulty of imagining the scenes in general. Our findings identify a specific computational role for the hippocampus in mental imagery and episodic recollection

Industry-science connections in agriculture : do public science collaborations and knowledge flows contribute to firm-level agricultural research productivity?

Prior research shows long-run productivity growth in agriculture is associated with increases in the stock of public scientific knowledge and private patented inventions. However, private inventions may be a function of the stock of public knowledge. In this paper, we examine the possibility that public knowledge contributes to productivity through its relationship with private sector invention. Our analysis identifies connections between the stock of public knowledge and private firm R&D and examines whether the degree of “connectedness” to public science is associated with greater firm-level research productivity in agriculture. Bibliographic information identifies the nature and degree to which firms use public agricultural science through citations and collaborations on scientific papers. Fixed effects models show that greater citations and collaborations with university researchers are associated with greater private agricultural research productivity