Behavior of potentially toxic elements from stoker-boiler fly ash in Interior Alaska: paired batch leaching and solid-phase characterization

Environmental Science and Pollution Research - Despite significant investigation of fly ash spills and mineralogical controls on the release of potentially toxic elements (PTEs) from fly ash,...     

The kin recognition system of carpenter ants (Camponotus spp.)

Summary Hamilton's (1964) hypothesis linking haplodiploidy and eusociality in the Hymenoptera could be reconciled with the occurrence of polygyny and multiple insemination if workers are able to distinguish full (3/4 related) sisters from other familiar matri- and patrilines within the colony, and direct altruistic behavior toward them preferentially. We examined this possibility in small genetically mixed nests of the carpenter ant Camponotus floridanus, formed by the transfer of worker pupae from two unrelated source colonies. In 120 h of observation on 12 queenright and 12 queenless nests, more than 15,000 behavioral interactions were recorded. Workers antennated familiar nonkin significantly more frequently than familiar sisters. However, they failed to discriminate consistently between kin and non-kin in food exchanges and grooming. Aggressive behavior was occasionally observed in some queenless nests, but almost never in the presence of a queen. When aggression did occur, it was directed significantly more often toward non-kin. Though related adult workers did not cooperate preferentially, the biases in antennation and aggression do indicate an ability to discriminate familiar kin from familiar nonkin, which may be employed in other contexts such as the rearing of reproductive brood.     

The application of standard methods for the determination of toxaphene in environmental media

In the United States, it is necessary to analyze for toxaphene using approved, validated methods acceptable to the regulatory agencies. As a result of an interlaboratory study and technical exchanges among the US EPA Region IV (EPA), the State of Georgia Environmental Protection Division (EPD), and Hercules Incorporated, guidelines for the application of SW-846 Method 8080 were developed. Results of analyses for sludge, soil, and water samples agreed within a percent relative standard deviation (% RSD) range of 6.9-20%. Through continued technical interchanges, guidance for the application of SW-846 Method 8081 has been developed. The results of analyses of fourteen split samples of soil and sediment produced a percent relative standard deviation that ranged from 1.6% to 127%, with an average of 38%. When two unusually divergent results were removed from consideration, the average % RSD reduced to 26%. The results of analyses of split samples show agreement between the EPA laboratory and a Hercules contract laboratory. Therefore, the guidance has achieved its purpose of producing agreement among data from different laboratories so that data reviewers may have assurance that the analytical method has been applied correctly and consistently for the determination of toxaphene in environmental samples.     

Bayesian areal wombling via adjacency modeling

Recently, public health professionals and other geostatistical researchers have shown increasing interest in boundary analysis, the detection or testing of zones or boundaries that reveal sharp changes in the values of spatially oriented variables. For areal data (i.e., data which consist only of sums or averages over geopolitical regions), Lu and Carlin (Geogr Anal 37: 265–285, 2005) suggested a fully model-based framework for areal wombling using Bayesian hierarchical models with posterior summaries computed using Markov chain Monte Carlo (MCMC) methods, and showed the approach to have advantages over existing non-stochastic alternatives. In this paper, we develop Bayesian areal boundary analysis methods that estimate the spatial neighborhood structure using the value of the process in each region and other variables that indicate how similar two regions are. Boundaries may then be determined by the posterior distribution of either this estimated neighborhood structure or the regional mean response differences themselves. Our methods do require several assumptions (including an appropriate prior distribution, a normal spatial random effect distribution, and a Bernoulli distribution for a set of spatial weights), but also deliver more in terms of full posterior inference for the boundary segments (e.g., direct probability statements regarding the probability that a particular border segment is part of the boundary). We illustrate three different remedies for the computing difficulties encountered in implementing our method. We use simulation to compare among existing purely algorithmic approaches, the Lu and Carlin (2005) method, and our new adjacency modeling methods. We also illustrate more practical modeling issues (e.g., covariate selection) in the context of a breast cancer late detection data set collected at the county level in the state of Minnesota.     

The use of magnetic resonance imaging in the prediction of birthweight

Extremes of fetal growth can increase adverse pregnancy outcomes, and this is equally applicable to single and multiple gestations. Traditionally, these cases have been identified using simple two-dimensional ultrasound which is quite limited by its low precision. Magnetic resonance imaging (MRI) has now been used for many years in obstetrics, mainly as an adjunct to ultrasound for congenital abnormalities and increasingly as part of the post-mortem examination. However, MRI can also be used to accurately assess fetal weight as first demonstrated by Baker et al in 1994, using body volumes rather than standard biometric measurements. This publication was followed by several others, all of which confirmed the superiority of MRI; however, despite this initial promise, the technique has never been successfully integrated into clinical practice. In this review, we provide an overview of the literature, detail the various techniques and formulas currently available, discuss the applicability to specific high-risk groups and present our vision for the future of MRI within clinical obstetrics.     

WATER RESOURCES DEVELOPMENT IN AN ENVIRONMENTALLY-CONSCIOUS ERA1

The Sierra Club, which has long fought selected water resource projects that it believes would be environmentally damaging, has come to the conclusion in recent years that much more basic reforms are required in water resources development activities if the demands for environmental quality now evidenced by the American people are to be satisfied. These reforms should not be limited to those that would have a direct effect on the environmental aspects of proposed projects, but also many others long advocated by the economics profession that would have favorable indirect effects. Among the urgent reforms with indirect effects are those involving revision of the procedures used in evaluating proposed projects. These procedures should be revised so that future evaluations will much more accurately reflect the economic and environmental merits of proposed projects. Basic reforms of tax policies are also needed that will eliminate most of the private profit available to those who can persuade the government to increase the value of their land through the construction of water projects. Finally, some additional actions can be taken that will have a direct impact on lessening the adverse environmental impact of water projects beyond the provisions of the National Environmental Policy Act of 1969.     

The kin recognition system of carpenter ants (Camponotus spp.)

Summary The phenotypic cues that provide for rejection of non-nestmates by workers of the ant genus Camponotus could derive from any or all of four sources: (1) environmental odors; (2) the individual's own genetically-determined recognition pheromones or discriminators; (3) a gestalt or mixture of transferable discriminators, produced by each nestmate and absorbed by all; and/or (4) the discriminators of the queen applied to all nestmates. To test these hypotheses, four series of small experimental colonies were created: inter- and intraspecific mixed colonies containing queens, queenless worker groups, and pairs of worker groups between which a single queen was repeatedly switched. Intraspecific mixed colonies and queenless groups were further divided into groups receiving different diets. Aggression of workers in 165 experimental colonies was assayed in a total of 4064 neutral arena tests. Workers adopted into inter- and intraspecific mixed colonies with queens were highly aggressive to unfamiliar kin from pure colonies, independent of diet and of the proportion of different kin groups in the colony. However, queenless workers exhibited less aggression to unfamiliar kin than to non-kin, demonstrating the existence of worker discriminators. Diet differences slightly enhanced aggression among unfamiliar queenless kin. Non-kin sharing a switched queen were as unaggressive to one another as were sisters. The ability to adopt queenless workers between colonies gradually declined over 1–2 wks following their emergence from pupae. We propose a hierarchy of importance of cue sources in determining nestmate discrimination in small Camponotus colonies: Queen discriminators> worker discriminators>environmental cues. A flow-diagram model of social insect kin recognition, based on the phenotype matching concept of Holmes and Sherman (1983), is discussed.     

Ecological boundary detection using Bayesian areal wombling

The study of ecological boundaries and their dynamics is of fundamental importance to much of ecology, biogeography, and evolution. Over the past two decades, boundary analysis (of which wombling is a subfield) has received considerable research attention, resulting in multiple approaches for the quantification of ecological boundaries. Nonetheless, few methods have been developed that can simultaneously (1) analyze spatially homogenized data sets (i.e., areal data in the form of polygons rather than point-reference data); (2) account for spatial structure in these data and uncertainty associated with them; and (3) objectively assign probabilities to boundaries once detected. Here we describe the application of a Bayesian hierarchical framework for boundary detection developed in public health, which addresses these issues but which has seen limited application in ecology. As examples, we analyze simulated spread data and the historic pattern of spread of an invasive species, the hemlock woolly adelgid (Adelges tsugae), using county-level summaries of the year of first reported infestation and several covariates potentially important to influencing the observed spread dynamics. Bayesian areal wombling is a promising approach for analyzing ecological boundaries and dynamics related to changes in the distributions of native and invasive species.     

Ancient divergences and recent connections in two tropical Atlantic reef fishes<Emphasis Type="Italic"> Epinephelus adscensionis</Emphasis> and<Emphasis Type="Italic"> Rypticus saponaceous</Emphasis> (Percoidei: Serranidae)

Reef habitats of the tropical Atlantic are separated by river outflows and oceanic expanses that may preclude larval dispersal or other population connections in shorefishes. To examine the impact of these habitat discontinuities on the intraspecific phylogeography of reef-associated species we conducted range-wide surveys of two amphi-Atlantic reef fishes that have dispersive pelagic larval stages. Based on 593 bp of mtDNA cytochrome b from the rock hind Epinephelus adscensionis and 682 bp from the greater soapfish Rypticus saponaceous (n=109 and 86, respectively), we found evidence of relatively ancient separations as well as recent surmounting of biogeographic barriers by dispersal or colonization. Rock hind showed slight but significant population genetic differentiation across much of the tropical Atlantic Ocean (_ST=0.056), but deep divergence between the southeastern United States and seven other localities from the Bahamas to the south, central and east Atlantic (mean pairwise d=0.040, overall _ST=0.867). The geographic distribution of the two rock hind lineages is highly unusual in genetic studies of Caribbean Sea reef fishes, because those lineages are separated by less than 250 km of open water within a major biogeographic region. In contrast, highly significant population genetic structure was observed among greater soapfish from the SW Caribbean, Brazil, and mid-Atlantic ridge (_ST=0.372), with a deep evolutionary separation distinguishing putative R. saponaceous from West Africa (mean pairwise d=0.044, overall _ST=0.929). Both species show evidence for a potential connection between the Caribbean and Brazilian provinces. While widespread haplotype sharing in rock hind indicates that larvae of this species cross oceanic expanses of as much as 2000 km, such a situation is difficult to reconcile with the isolation of populations in Florida and the Bahamas separated by only 250 km. These findings indicate that populations of some species in disjunct biogeographic zones may be isolated for long periods, perhaps sufficient for allopatric speciation, but rare gene flow between zones may preclude such evolutionary divergence in other species.Communicated by P.W. Sammarco, Chauvin