Shark-bitten vertebrate coprolites from the Miocene of Maryland

Coprolites (fossilized feces) preserve a wide range of biogenic components, from bacteria and spores to a variety of vertebrate tissues. Two coprolites from the Calvert Cliffs outcrop belt (Miocene-aged Chesapeake Group), MD, USA, preserve shark tooth impressions in the form of partial dental arcades. The specimens are the first known coprolites to preserve vertebrate tooth marks. They provide another example of trace fossils providing evidence of prehistoric animal behaviors that cannot be directly approached through the study of body fossils. Shark behaviors that could account for these impressions include: (1) aborted coprophagy, (2) benthic or nektonic exploration, or (3) predation.     

The transfer of different forms of 35S to goat milk

Sulphur-35 is released during the routine operation of UK gas-cooled reactors. An experiment to determine the rates of transfer of different forms of (35)S to goat milk is described. Lactating goats received (35)S orally as single administrations of sulphate, L-methionine, or grass contaminated either through root uptake of (35)S as sulphate or through aerial deposition of (35)S as carbonyl sulphide onto the grass. Transfer was higher for (35)S administered as methionine compared with (35)S administered as sulphate. Changes in activity concentrations in milk for all sources of (35)S demonstrated two components of loss. The first component had a half-life of circa 1 d for all sources, the second was longer in goats administered carbonyl sulphide (44 d) than in all of the other treatments (circa 10 d). The rate of transfer of (35)S to milk of a further group of goats receiving (35)S-sulphate daily appeared to reach equilibrium within 30 d. Extrapolation of transfer parameters derived to other dairy ruminants is discussed.     

Naming,Mourning, and the Work of Earthly Coexistence

Setting out from Jacques Derrida’s assertion that every act of naming is “a foreshadowing of mourning” ([2008. The animal that therefore I am. (M.-L. Mallet, Ed., D. Wills, Trans.). New York, NY: Fordham University Press], p. 20), this paper argues that the work of earthly coexistence is underwritten by the intertwined practices of naming and mourning. The paper demonstrates that names provide access to and shape our perceptions of earthly entities; that the act of naming prepares us for the work of mourning; that the proper names given to endlings provide poignant points of access to species on the edge of extinction; that species names disclose species as such and, thus, enable us to grieve not just particular living organisms but entire ways of life; and that the name given to the current geological epoch, the “anthropocene,” simultaneously reflects and engenders a mode of awareness which enables us to relinquish those ways of being human that no longer seem sustainable and carry forth those that promise to enrich earthly coexistence.     

Biomarker responses of <Emphasis Type="Italic">Peromyscus leucopus</Emphasis> exposed to lead and cadmium in the Southeast Missouri Lead Mining District

Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.     

Energy Communication: Theory and Praxis Towards a Sustainable Energy Future

This essay comments and expands upon an emerging area of research, energy communication, that shares with environmental communication the fraught commitment to simultaneously study communication as an ordinary yet potentially transformative practice, and a strategic endeavour to catalyse change. We begin by defining and situating energy communication within ongoing work on the discursive dimensions of energy extraction, production, distribution, and consumption. We then offer three generative directions for future research related to energy transitions as communicative processes: analysing campaigns’ strategic efforts, critically theorizing energy’s transnational power dynamics, and theorizing the energy democracy movement.     

Politics of Edibility: Reconceptualizing Ecological Relationality

Taking the Infinity Burial Project (IBP) as its inspiration, this essay theorizes a politics of edibility by way of decomposing the discursive boundaries erected between human bodies and environments. In particular, this essay reads the IBP as a deconstruction of another dualism—eater/eaten—that permeates and informs cultural practices from birth to burial. Mobilizing a rhetoric of carnality, the IBP decomposes the human body's relation to its environments, merging its statuses as eater and eaten. At the same time, this rhetoric of carnality also emphasizes the irreducibly productive nature of consumption as an articulatory practice in its own right. As this essay argues, a politics of edibility not only recognizes the superficiality of the body/environment and eater/eaten dichotomies but it also respects the relations generated in the wake of their deconstruction.     

Assessing an exotic plant surveying program in the Mojave Desert, Clark County, Nevada, USA

Exotic species can threaten native ecosystems and reduce services that ecosystems provide to humans. Early detection of incipient populations of exotic species is a key step in containing exotics before explosive population growth and corresponding impacts occur. We report the results of the first three years of an exotic plant early detection and treatment program conducted along more than 3,000 km of transportation corridors within an area >1.5 million ha in the Mojave Desert, USA. Incipient populations of 43 exotic plant species were mapped using global positioning and geographic information systems. Brassica tournefortii (Sahara mustard) infested the most soil types (47% of 256) surveyed in the study area, while Nicotiana glauca (tree tobacco) and others currently occupy less than 5% of soil types. Malcolmia africana (African mustard) was disproportionately detected on gypsum soils, occurring on 59% of gypsum soil types compared to 27% of all surveyed soils. Gypsum soils constitute unique rare plant habitat in this region, and by conventional wisdom were not previously considered prone to invasion. While this program has provided an initial assessment of the landscape-scale distribution of exotic species along transportation corridors, evaluations of both the survey methods and the effectiveness of treating incipient populations are needed. An exotic plant information system most useful to resource mangers will likely include integrating planning oriented coarse-scale surveys, more detailed monitoring of targeted locations, and research on species life histories, community invasibility, and treatment effectiveness.