Methods for constructing and balancing ecosystem flux charts: new techniques and software

We describe a general computer program which employs novel techniques to analyze carbon (energy) and nutrient flows in complex food webs. The program uses estimates of metabolic/physiological parameters and ecosystem fluxes to simultaneously calculate the most likely balanced flux charts for carbon and a nutrient. We give an example of how the model can explore the theoretical issues involved with nutrient limitation and recycling.     

Evolution and longevity-assurance processes

The role of the development of information fidelity systems in evolution is explored, with evidence that the loss in the ability to maintain the integrity of homeostasis in organisms over time, aging, is correlated with the loss in the ability to maintain integrity at the molecular biological level. Evolutionary-comparative analysis places an upper limit on the number of these systems important to the evolution of longevity in the primates, and suggests the importance of insuring the stability of information bearing macromolecules in evolution and the role of modulators of damage to these moieties in the expression of the senescent state     

Technical and theoretical considerations in the HLA typing of amniotic fluid cells for prenatal diagnosis and paternity testing

HLA typing of amniotic fluid cells has been used for the prenatal diagnosis of the HLA linked diseases congenital adrenal hyperplasia (21-OH-deficiency (21-OH-def) type) and complement C4 deficiency and it has also been used for the prenatal de termination of paternity. There are, however, technical difficulties in this test associated with the weak expression of some B locus antigens on amniotic fluid cells, and theoretical difficulties related to associations between particular HLA antigens and the 21-OH-def allele. Since certain HLA-B locus antigens are found in significantly increased frequencies among patients with 21-OH-def, there is a relatively high incidence of HLA-B homozygosity among the patients and over 40 percent of the parents of these patients share one or more HLA-B locus antigens. Results of some prenatal HLA typing tests may thus be difficult to interpret, and supplementary tests should be used whenever possible. HLA typing of amniotic cells is, however, the only available procedure for prenatal diagnosis of C4 deficiency and it is the best available procedure for prenatal determination of paternity. A modification of our original procedure allows HLA typing to be performed with increased numbers of HLA typing sera, and sera with optimum reactivity for amniotic fluid cells have now been selected for the definition of most of the more commonly expressed HLA antigens. Although amniotic fluid cells do not express DR antigens, amniotic fluid cells can be typed for the HLA-linked marker glyoxalase I (GLO) and this may be the informative for prenatal diagnosis in some cases.     

Sorption-Desorption of Atrazine and Diuron in Soils from Southern Brazil

The objective of this study was to investigate the behavior of sorption and desorption of the herbicides atrazine (6-chloro-N ²-ethyl-N ⁴-isopropyl-1,3,5-triazine-2,4-diamine) and diuron [3-(3,4-dichlorophenyl)-1,1-dimethyleurea] in soil samples from a typical lithosequence located in the municipality of Mamborê (PR), southern Brazil. Five concentrations of ¹⁴C-atrazine and ¹⁴C-diuron were used for both herbicides (0.48, 0.96, 1.92, 3.84, and 7.69 mg L^?1). Sorption of both herbicides correlated positively with the organic carbon and clay content of the soil samples. Sorption isotherms were well described by the Freundlich model. The slope values of the isotherm (N) ranged from 0.84 to 0.90 (atrazine) and from 0.75 to 0.79 (diuron) for the lithosequence samples. Sorption of diuron was high regardless of the soil texture or the concentration added. The desorption isotherms for atrazine and diuron showed good fit to the Freundlich equation (R ² ≥ 0,87). Atrazine slope values for the desorption isotherms were similar for the different concentrations and were much lower than those observed for the sorption isotherms. Significant hysteresis was observed in the herbicide desorption. When the two herbicides were compared, it was found that diuron (N = 0.06–0.22) presented more pronounced hysteresis than atrazine. The results showed that, quantitatively, a greater atrazine fraction applied to these soils remains available to be leached in the soil profile, as compared to diuron.     

Report on International Affairs Committee

This is a report on Meetings of Representatives of National Air Pollution Preventions Associations to Consider the Establishment of an International Union, held in Washington, D. C, June 18–19, 1964 and Houston, Texas, June 21–22, 1964.     

Climatic and stream-flow controls on tree growth in a Western montane riparian forest

Humans have severely impacted riparian ecosystems through water diversions, impoundments, and consumptive uses. Effective management of these important areas is becoming an increasingly high priority of land managers, particularly as municipal, industrial, and recreational demands for water increase. We examined radial tree growth of four riparian tree species (Pinus jeffreyi, Populus trichocarpa, Betula occidentalis, and Pinus monophylla) along Bishop Creek, California, and developed models relating basal area increment (BAI) and relative basal area increment (RBAI) to climatic and stream flow variables. Between years 1995–1999, univariate regression analysis with stream flow explained 29 to 61% of the variation in BAI and RBAI among all species except P. trichocarpa; growth by P. trichocarpa was not significantly related to stream flows over this period. Stepwise linear regression indicated that species responded differently to climatic variables, and models based on these variables explained between 33 to 86% of variation in BAI and RBAI during the decade of the 1990s. We examined branch growth of P. trichocarpa for sensitivity to differences in stream flow regimes and found that annual branch growth did not vary between a high- and low-flow site, but that annual branch growth was significantly higher in wet years with greater stream flows. Our results support the establishment of site-specific management goals by land managers that take into account all of the important tree species present in riparian ecosystems and their differential responses to altered hydrologic condition. Instream flow requirements for maintaining tree growth and vigor are only one of the species-specific responses that need to be evaluated, and these assessments should attempt to separate experimentally stream-flow (managed) controls from climatic (unmanaged) controls on growth.     

The connecticut indirect source review: A methodology and model for evaluating CO concentrations

The body of information presented in this paper is directed to air pollution engineers who are concerned with the effect of indirect sources on ambient concentrations of carbon monoxide (CO). Data taken under controlled conditions are used to empirically derive and calibrate a model for predicting CO concentrations in the vicinity of roadway intersections and other points of possible vehicular congestion. Since the predicted free flow CO contribution of vehicles traveling at normal road speeds is relatively low, it is concluded that idling vehicles at points of congestion are the major cause of CO violations, and that state and federal programs should place more emphasis on relieving congestion and reducing idling emission rates in new vehicles.     

Ambient carbon monoxide monitoring and instrumentation

The information presented in this paper is directed to air pollution engineers who are concerned with monitoring Carbon Monoxide. This paper evaluates systems for CO sampling under conditions where the receptor is located at intersections within 40 meters of the road edge. Non-Dispersive Infrared and electrochemical analysis techniques are used in conjunction with continuous recording, continuous bag sampling, and meter readings at 5 second intervals. The relative accuracy of each system is examined and the conditions for which each system is best suited are described.     

Desulfurization of Caribbean Fuel

An American Petroleum Institute study of desulfurization of Caribbean fuel oil was completed in February 1967. The report is unique in that proprietary information was made available to the contractor, the Bechtel Corp., by task force members and licensors of desulfurization processes. Thus confidential information never before available to a single organization was used to develop feasibility and incremental costs of various processes for desulfurization. The report provides needed guideposts for decision-making by governmental units as well as by industry. Incremental costs are presented for intermediate levels of desulfurization from the normal level for Caribbean heavy fuel oil of 2.6% down to 0.5%, as well as the sensitivity of costs to sulfur credits and to rate of recovery of invested capital. Degree of justifiable confidence in the various data is discussed. Effects of desulfurization on other characterisics of the fuel oil are also discussed.     

Utility of North Atlantic Right Whale Museum Specimens for Assessing Changes in Genetic Diversity

Abstract: We examined six historical specimens of the endangered North Atlantic right whale ( Eubalaena glacialis ) using DNA isolated from documented baleen plates from the late nineteenth and early twentieth centuries. Sequences from the mitochondrial DNA (mtDNA) control region from these samples were compared with those from a near-exhaustive survey (269 of approximately 320 individuals) of the remaining right whales in the western North Atlantic Ocean. Our results suggest that there has been only relatively modest change in maternal lineage diversity over the past century in the North Atlantic right whale population. Any significant reduction in genetic variation in the species most likely occurred prior to the late nineteenth century. One historical specimen was from the last documented female capable of propagating one of the maternal lineages in the population today; no females in the existing population have been found to carry this mtDNA haplotype. Analysis of the only specimens from the eastern North Atlantic right whale population ever to be examined revealed that eastern and western North Atlantic right whales may not have been genetically differentiated populations. Loss of gene diversity experienced by North Atlantic right whales over the last century has been modest, and the six decades of protection have been successful in maintaining much of the maternal lineage diversity that was present in the late nineteenth century.