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631.
Darryl L. York John L. Cummings Richard M. Engeman Kate L. Wedemeyer 《International biodeterioration & biodegradation》2000,45(3-4)
Bird strikes to aircraft are a serious economic and safety problem in the United States, annually causing millions of dollars in damage to civilian and military aircraft and the occasional loss of human life. We observed movements of 1236 neckbanded lesser Canada geese (Branta canadensis parvipes) to determine efficacy of hazing as a means to reduce goose presence at Elmendorf Air Force Base (EAFB), Anchorage, Alaska from August to October 1997. Emphasis was on movements of geese onto EAFB with additional data collected at the other two major airports in the area, Anchorage International Airport (AIA) and Merrill Field Airport (MFA). Daily observations indicated the presence of 208 individual neckbanded geese on EAFB, and 20% returned more than once after being hazed from EAFB. We identified three staging areas, geese utilized prior to entering EAFB, and three post-hazing dispersal sites. Collared geese began moving onto EAFB 30–40 days post-molt with the largest proportions moving onto EAFB 70–90 days post-molt. We observed 75 neckbanded geese on AIA from seven molting sites, and 23% returned more than once after being hazed from AIA. We observed 141 neckbanded geese on MFA from 14 molting sites, and 21% returned more than once after being hazed from MFA. Our data indicated that as long as local goose populations increase, large numbers of Anchorage area geese are likely to enter one of the airports creating a variety of management problems. Hazed geese returning to airports multiple times present a special hazard to aircraft safety because they appear to have become habituated to non-lethal scare tactics. We recommend an integrated management approach to limit the Anchorage area goose population utilizing various control techniques which are acceptable to Anchorage residents while continuing the hazing program at area airports. 相似文献
632.
Darryl L. Daley Jerry S. Vande Berg 《Biochimica et Biophysica Acta (BBA)/General Subjects》1976,437(1):211-220
Cyclic AMP and its dibutyryl derivative inhibit neuronal firing of the labellar sugar sensitive receptor of the blowfly when applied in conjunction with the stimulant sucrose. Furthermore, simultaneous application of aminophylline (phosphodiesterase inhibitor) and sucrose or in combination with cyclic AMP caused a similar depression of the sugar receptors response. In contrast, dibutyryl cyclic GMP elicited an increase in sugar receptor firing when applied with sucrose to the sugar receptor. Either 5′-AMP or 5′-GMP in combination with sucrose had no discernable effect on the sugar receptors response. Different ratio combinations of cyclic AMP and dibutyryl cyclic GMP showed the striking inhibitory effect of cyclic AMP upon the dibutyryl cyclic GMP elicited increases in receptor firing frequency. Therefore, it is suggested that these two nucleotides may be mediating different but complimentary aspects of sugar receptor function in a push-pull manner. 相似文献
633.
Darryl G. Stout 《Cryobiology》1981,18(5):521-527
A method for calculating the contraction strain (or the converse stress) to protoplasts of frozen multicellular plant tissues is described. The method requires (i) a nuclear magnetic resonance (NMR) measure of the quantity of bound water per gram dry weight (K), (ii) a gravimetric measure of grams of H2O per gram dry weight (L0), (iii) a measure of solute concentration in non-frozen cells (C0), (iv) an estimate of the specific volume of tissue dry matter (0.625 ml/g), (v) an NMR measure of the fraction of tissue water that is intracellular osmotic water (Pa), and (vi) a measure of the fraction of the dry weight that is cell wall (fcw). This method is a refinement of previous methods that calculate cell contraction strain from four (L0, K, C0, and 0.625) of the above six measurements. Comparison of the calculated protoplast strain to the calculated cell strain indicates that the two measures are quite similar, however, the measure of protoplast strain is, in theory, a more appropriate measure of the freezing strain. It is also demonstrated that derivation of a measure of strain from the parameters controlling it is useful, because it allows one to evaluate the relative contribution of each parameter in preventing the development of strain. 相似文献
634.
Peter L. Steponkus Darryl G. Stout Joe Wolfe Richard V. E. Lovelace 《The Journal of membrane biology》1985,85(3):191-198
Summary Evidence is presented to support the hypothesis that electrical potentials generated during the freezing of aqueous solutions (the Workman-Reynolds effect) may contribute to the destabilization of the plasma membrane and cryoinjury of isolated protoplasts. Specifically. (1) electric potential diffrences of sufficient magnitude to cause lysis of the plasma membrane occur during the rapid freezing of isolated protoplasts suspended in sorbitol: (2) survival of protoplasts is inversely correlated with the magnitude of the potential difference and (3) cold acclimation increases the stability of the plasma membrane to applied electric fields. A discussion is given of the different physical phenomena though to be involved in the Workman-Reynolds effect. The basis equations for these phenomena are outlined. 相似文献
635.
Given near unanimity in the environmental and industrial communities about the need for a new generation of environmental technology, the policy process unfortunately lags behind in moving toward this objective. This article examines causes and remedies for this gap in the context of American environmental policy. U.S. environmental laws continue to be pervaded by structural biases against new technology, and the complexity of their administration exacerbates the problem. Within the last few years, several important reform initiatives have arisen from inside the regulatory community; however, these can only go so far, given the current statutory framework Congress, too long quiescent, needs to become involved. A legislative reform package is proposed consisting of four main elements: a legislative mandate that makes promotion of technological innovation an explicit environmental objective; elimination of structural features in current law that impede innovation; creation of a new framework for standard-setting and enforcement that puts every firm on a trajectory toward environmental and technological improvement; and enlisting regulation as a "demand-pull" for environmentally superior technology. 相似文献