Energy needs versus environmental pollution: a reconciliation?

In this article I have presented, for discussion, a proposed system for energy generation by which the principal sources of environmental pollution by power plants could be eliminated. For stationary power plants the concept appears feasible technically and, according to my " horseback estimates," perhaps economically as well, depending upon the economic value of the by-products of sulfur, CO(2), water, and possibly nitrogen, and upon the price we are willing to pay for a clean environment .Thus, a more thorough engineering and economic analysis to explore these and other factors in greater depth seems warranted. In the case of turbine-driven vehicles, the technical and economic feasibility of widespread distribution and handling of the fuel constitutes a serious question, but one which deserves equally serious consideration before the possibility is discounted. The reports of the cited study panels notwithstanding, the technology required for the proposed system exists today, with one exception. This exception (which is not essential for trial of the system but will be required for its complete fruition) is the development of a nuclear reactor for the prime purpose of delivering process heat for the steam reforming of natural gas and, ultimately, for gas production from coal in a continuous process, such as those discussed by Pieroni et al. (16). Today's intermittent processes of coking and gas production are both archaic and themselves large sources of atmospheric pollution, and a development program aimed at advancing the technology of the coal industry in this regard would seem long overdue. The report of the PSAC Environmental Pollution Panel recommended "demonstration of the feasibility and economy of new developments for abating or controlling pollution through their use at Federal installations" and suggested the coalburning TVA power plants as a likely place for such demonstration. This suggestion is doubly appropriate since the TVA is in a region of subnormal " atmospheric ventilation" (8). By design these plants are adjacent to the AEC's Oak Ridge National Laboratory, and such a location would seem ideal for an experiment on the wedding of nuclear and fossil sources of energy. In comments on a preliminary draft of this article, proponents of "conventional " nuclear power pointed out that such power is hard to beat on the basis of cost, and that dissipation of heat to the air by way of cooling towers can also be accomplished in conventional plants (17). These observations are individually correct but not compatible: the low power costs cited are for very large plants [of the order of 1000 mega-watts lectrical) and larger], and the costs of cooling towers and associated equipment needed to dissipate such large amounts of heat [of the order of 2000 megawatts (thermal)] to air from a closed cycle would offset the power cost advantage of the large plant. In regard to the proposed use of nuclear process heat, Weinberg (20) has expressed doubt that much advantage can be derived from this approach because the temperatures involved are too high for low-cost reactors, and heat transfer from surfaces could involve materials problems. In the case of gas production, this is indeed an anticipated problem-not a technologically insuperable one, but a problem of reducing the cost of the materials required (16). Indeed, Weinberg himself has mentioned this possible use of nuclear heat in a recent publication discussing the steam reforming of coal to liquid fuel(21). Also, an improved process for synthesizing methane from lignitec has recently been reported (22). Since the earlier studies date back a decade, a new look at the problems and costs involved relative to the benefits to be derived (not the least of which could be new vigor for the coal industry) would seem to be in order. In the case of steam reforming of natural gas, the temperature level (about 1500 degrees F) is such that the technology is available today, and a process-heat-reactor design study could be initiated without awaiting further developments.     

Quartz: extreme preferred orientation produced by annealing

Annealing of samples of flint under high pressure, after hot-working in the beta-quartz stability field, produced an exceedingly strong concentration of c-axes parallel to the direction of compression. A specimen deformed under identical conditions, but not annealed, exhibited a much weaker orientation. The strength of the annealed orientation rivals that of the remarkable "cube texture" produced by annealing some face-centered cubic metals after extreme reduction by rolling.     

Molecular phylogenetics of mastodon and Tyrannosaurus rex

We report a molecular phylogeny for a nonavian dinosaur, extending our knowledge of trait evolution within nonavian dinosaurs into the macromolecular level of biological organization. Fragments of collagen alpha1(I) and alpha2(I) proteins extracted from fossil bones of Tyrannosaurus rex and Mammut americanum (mastodon) were analyzed with a variety of phylogenetic methods. Despite missing sequence data, the mastodon groups with elephant and the T. rex groups with birds, consistent with predictions based on genetic and morphological data for mastodon and on morphological data for T. rex. Our findings suggest that molecular data from long-extinct organisms may have the potential for resolving relationships at critical areas in the vertebrate evolutionary tree that have, so far, been phylogenetically intractable.     

Phosphorylation networks regulating JNK activity in diverse genetic backgrounds

Cellular signaling networks have evolved to enable swift and accurate responses, even in the face of genetic or environmental perturbation. Thus, genetic screens may not identify all the genes that regulate different biological processes. Moreover, although classical screening approaches have succeeded in providing parts lists of the essential components of signaling networks, they typically do not provide much insight into the hierarchical and functional relations that exist among these components. We describe a high-throughput screen in which we used RNA interference to systematically inhibit two genes simultaneously in 17,724 combinations to identify regulators of Drosophila JUN NH(2)-terminal kinase (JNK). Using both genetic and phosphoproteomics data, we then implemented an integrative network algorithm to construct a JNK phosphorylation network, which provides structural and mechanistic insights into the systems architecture of JNK signaling.     

Adaptive phenotypic plasticity in response to climate change in a wild bird population

Rapid climate change has been implicated as a cause of evolution in poorly adapted populations. However, phenotypic plasticity provides the potential for organisms to respond rapidly and effectively to environmental change. Using a 47-year population study of the great tit (Parus major) in the United Kingdom, we show that individual adjustment of behavior in response to the environment has enabled the population to track a rapidly changing environment very closely. Individuals were markedly invariant in their response to environmental variation, suggesting that the current response may be fixed in this population. Phenotypic plasticity can thus play a central role in tracking environmental change; understanding the limits of plasticity is an important goal for future research.     

Comment on "Wandering minds: the default network and stimulus-independent thought"

Mason et al. (Reports, 19 January 2007, p. 393) attributed activity in certain regions of the "resting" brain to the occurrence of mind-wandering. However, previous research has demonstrated the difficulty of distinguishing this type of stimulus-independent thought from stimulus-oriented thought (e.g., watchfulness). Consideration of both possibilities is required to resolve this ambiguity.