Sex in Development: Science, Sexuality, and Morality in Global Perspective

Sex in Development: Science, Sexuality, and Morality in Global Perspective. Vincanne Adams and Stacy Leigh Pigg, eds. Durham, NC: Duke University Press, 2005. 342 pp.     

Refuge from cannibalism in complex-structured habitats: implications for the accumulation of invertebrate predators

Abstract.  1. Like many invertebrate predators, the wolf spider Pardosa littoralis Banks (Araneae: Lycosidae) accumulates in complex-structured habitats replete with leaf litter (thatch). Here we test the hypothesis that P. littoralis accumulates in complex habitats to gain refuge from cannibalism.
2. A laboratory experiment examined the effects of habitat complexity (thatch present or absent) and size-class pairing of conspecific spiders (large vs. small, small vs. small, and large vs. large) on the incidence of cannibalism. Spider survival was significantly higher (22%) in complex-structured habitats with thatch than in simple-structured habitats lacking thatch. Furthermore, cannibalism occurred more frequently in P. littoralis when the size of conspecifics was asymmetric (large vs. small spiders) than when spiders were of equal size. There was no interactive effect of habitat complexity and size-class pairing on spider survival.
3. A field experiment examined the effects of habitat complexity, conspecific density, and access to alternative prey on the prevalence of cannibalism in P. littoralis . Access to alternative prey significantly increased the number of spiders recovered from field enclosures, as did the presence of leaf litter thatch. That fewer spiders were recovered when thatch and alternative prey were absent suggests that cannibalism was most prevalent under these conditions.
4. Overall, results suggest that habitat complexity reduces agonistic interactions and cannibalism among wolf spiders, providing encouragement to pest managers that the structure of agricultural habitats can be managed to maximise densities of generalist predators for enhanced pest suppression.     

CLONING, PARENTHOOD, AND GENETIC RELATEDNESS

In this paper I examine what I take to be the best case for reproductive human cloning, as a medical procedure designed to overcome infertility, and argue that it founders on an irresolvable tension in the attitude towards the importance of being ‘genetically related’ to our children implied in the desire to clone. Except in the case where couples are cloning a child they have previously conceived naturally, cloning is unable to establish the right sort of genetic relation to make couples the parents of their cloned child. If anybody is the genetic parent of a cloned child it is the natural parent(s) of the DNA donor. Paradoxically, in order to resist the claims of the parents of the donor to the cloned child, the argument for human reproductive cloning must place more weight on the intention to parent a child, than we do in cases of ordinary reproduction. It must insist that the parental relation is established by the intentions of the couple who bring a clone into the world and not by their genetic relation to the child. The emphasis placed on intention as establishing the parental relationship works to undermine the justification for cloning in the first place. For cloning to play a useful role as a reproductive technology, it must allow couples to become parents who could do so no other way. However, to the extent that intention is sufficient to establish parenthood, adoption or surrogacy, which are existing alternatives to cloning, will serve equally well to allow couples to become parents.     

Spatial and temporal assessment of sources contributing to the annual austral spring mid-tropospheric ozone maxima over the tropical South Atlantic

The primary source of the annual austral spring mid‐tropospheric ozone maxima over the tropical South Atlantic has generally been assumed to be biomass burning. However, ozone precursor emissions from biogenic, lightning, and anthropogenic sources in subequatorial Africa before and during the ozone peak are shown to be comparable, if not greater, in magnitude to regional biomass burning production. Moreover, an investigation of the spatial and temporal characteristics of these ozone precursor sources (i.e. vegetative and microbial activity, lightning‐induced generation, and anthropogenic emissions) suggests that these alternative sources can potentially make a substantial contribution to the seasonal ozone peak. This argument is supported by the practical limitations of atmospheric transport available to regionally produced ozone and ozone precursors.     

Transferring Research to Endangered Species Management

ABSTRACT In the natural resource and wildlife profession, we face difficulties in the production, diffusion, and transfer of rigorously tested science, especially when facing entrenched management paradigms. We present 3 case studies to illustrate the challenges in changing entrenched management paradigms for endangered species. Here we examine specifically what factors helped or hindered the adoption of management practices through the theoretical framework developed for the dissemination of technologies. An examination of 3 case studies suggests that active communication and advocacy of scientific findings, along with simple, visible results, will aid researchers in the acceptance and adoption of their research. Management agencies that increase openness and communication with outside experts, reduce bureaucratic procedures, and localize decision making increase the likelihood that new scientific ideas will be adopted by the agency. We also suggest adaptive resource management as a strategy for endangered species management may foster many of the characteristics that aid in the adoption of scientific ideas into management activities.     

Morphometric analysis of the Taxus wallichiana complex (Taxaceae) based on herbarium material

We used morphological and geographical data of 128 herbarium specimens of the Taxus wallichiana complex in eastern Asia to investigate their utilization in discriminating and identifying taxa included in the complex. One bud scale and 26 leaf characters were used to separate T. fuana , T. wallichiana var. wallichiana , T. wallichiana var. mairei , T. wallichiana var. chinensis and T. sumatrana by K-means clustering and dendrograms using Ward's distance. Out of the 27 characters examined 21 were found to be well correlated with geographical patterns. T. fuana was morphologically the most distant taxon, while T. sumatrana clustered among the T. wallichiana varieties. After correcting misidentifications of the specimens in T. wallichiana , its varieties occupied discrete geographical ranges, except for some limited sympatry of varieties mairei and chinensis east of the Tanaka–Kaiyong line and the Sichuan Basin, China. Our analysis demonstrates the importance of consistency in character selection and definition in the identification of morphologically difficult taxa and the power of combining morphometric and geographical data in clarifying their spatial distribution.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 307–335.     

Host-herbivore studies of Stenoscepa sp. （Orthoptera：Pyrgomorphidae）, a high-Ni herbivore of the South African Ni hyperaccumulator Berkheya coddii （Asteraceae）

Nymphs of Stenoscepa sp. feed on leaves of the Ni hyperaccumulator Berkheya coddii at serpentine sites in Mpumalanga Province, South Africa. These sites contain Ni hyperaccumulators, Ni accumulators, and plants with Ni concentrations in the normal range. We conducted studies to： （i） determine the whole-body metal concentration of nymphs （including those starved to empty their guts）; （ii） compare Stenoscepa sp. nymphs against other grasshoppers in the same habitat for whole-body metal concentrations; and （iii）compare the suitability of Ni hyperaccumulator and Ni accumulator plants as food sources for Stenoscepa sp. and other grasshoppers. Stenoscepa nymphs had extremely high whole-body Ni concentrations （3 500μg Ni/g）. This was partly due to food in the gut, as starved insects contained less Ni （950 pg Ni/g）. Stenoscepa nymphs survived significantly better than other grasshoppers collected from either a serpentine or a non-serpentine site when offered high-Ni plants as food. In a host preference test among four Berkheya species （two Ni hyperaccumulators and two Ni accumulators）, Stenoscepa sp, preferred leaves of the Ni hyperaccumulator species. A preference experiment using leaves of three Senecio species （of which one species, Senecio coronatus, was represented by both a Ni hyperaccumulator and a Ni accumulator population） showed that Stenoscepa sp. preferred Ni accumulator Senecio coronatus leaves to all other choices. We conclude that Stenoscepa sp. is extremely Ni-tolerant. Stenoscepa sp. nymphs prefer leaves of hyperaccumulator Berkheya species, but elevated Ni concentration alone does not determine their food preference. We suggest that the extremely high whole-body Ni concentration of Stenoscepa nymphs may affect food web relationships in these serpentine communities.     

Microsatellite loci for the progenetic trematode,Coitocaecum parvum (Opecoelidae)

Nine polymorphic microsatellite loci were characterized from the freshwater trematode Coitocaecum parvum. This parasite can either reproduce sexually in the definitive host or produce eggs by selfing inside its second intermediate host. Two to 11 alleles per locus were detected in 24 trematode sporocysts and observed heterozygosities ranged from 0.04 to 0.96. These loci will be useful for identifying parasite genetic clones within hosts and testing for effects of relatedness on parasite life history strategy.     

Activity of the diastereoisomers of 13,23-dimethylpenta-triacontane, the sex pheromone of Glossina pallidipes, and comparison with the natural pheromone

ABSTRACT. All three synthetic diastereoisomers of 13,23-dimethyl-pentatriacontane, the pheromone of Glossina pallidipes (Austen), have been tested in the G. pallidipes sex pheromone bioassay, together with one of the four diastereoisomers of 13,17-dimethylpentatriacontane, originally proposed as a candidate pheromone of G. pallidipes. Of the three isomers of 13,23-dimethylpentatriacontane only the (13R,23S) isomer was active with an ED-50 of 4.47±1.09/μg (mean±SD). The (13R,17R)-13,17-dimethylpentatriacontane was inactive. The diastereo-isomeric mixtures of 13,17- and 13,23-dimethylpentatriacontane were active with ED-50 values of 17.88±1.25/μg and 8.88±1.15μg respectively. The natural pheromone was active with an ED-50 of 8.07±1.17 μg indicating it to be a diastereoisomeric mixture.