Short-Term In Vitro Culture and Molecular Analysis of the Microsporidian, Enterocytozoon bieneusi

ABSTRACT. The microsporidium, Enterocytozoon bieneusi , causes a severe, debilitating, chronic diarrhea in patients with the acquired immunodeficiency syndrome. Specific diagnosis of intestinal microsporidiosis, especially due to Enterocytozoon , is difficult and there is no known therapy that can completely eradicate this parasite. Preliminary studies indicate that a short term (about 6 months) in vitro culture of this parasite yielding low numbers of spores, may be established by inoculating human lung fibroblasts and/or monkey kidney cell cultures with duodenal aspirates and or biopsy from infected patients. The cultures may subsequently be used for the isolation and molecular analysis of parasite DNA.     

Patterns of Phylogenetic Differentiation in the Toxochelyid and Cheloniid Sea Turtles

The patterns of phylogenetic differentiation in the closelyrelated sea turtle families Toxochelyidae and Cheloniidae followedstrikingly different courses. In the Toxochelyidae there isa gradual increase in specialization toward a pelagic mode oflife with time. The phyletic picture is thus that of a shrub.In the Cheloniidae, by contrast, the geologically oldest representativesof the family are the most advanced, pelagic species, and theRecent species, except for Eretmochelys imbricata, are amongthe least specialized members of the family. There is good evidencethat the living species are the only cheloniids that have theirhind limbs modified as rudders, and the very close similaritybetween the limb skeletons of these species suggests that theyare more closely related to each other than any of them areto any earlier form. A similar case can be made for the earlyCaenozoic cheloniids. The phylogenetic pattern, therefore, suggestsrepeated episodes of pelagic specialization from a central,unspecialized stock, a pattern referred to as iterative evolution.     

Audiovisuals Reviews

Book reviewed in this article:
LITHIC TECHNOLOGY FILMS: A Tale of Two Rivers . Produced by CLYDE B. SMITH.
LITHIC TECHNOLOGY FILMS: Lascaux: Cradle of Man's Art . Directed by WILLIAM C. CHAPMAN.
LITHIC TECHNOLOGY FILMS: Prehistoric Images . 1955. Directed by THOMAS L. ROWE     

Canarian land snail diversity: conflict between anatomical and molecular data on the phylogenetic placement of five new species of Napaeus (Gastropoda, Pulmonata, Enidae)

Five new species of land snail (family Enidae) are described from La Gomera (Canary Islands) of which the majority, on the basis of anatomy alone, could be incorporated within a new supraspecific taxon. In addition to the morphological study of these new species, a region of the 16S mitochondrial gene is sequenced from three of the new species and a range of species of Napaeus from within its two subgenera ( Napaeinus and Napaeus ) . There is a disparity between the morphological and preliminary molecular phylogenetic data. Possible explanations for this conflict are discussed, as well as the evolutionary relationships among these different taxa, and it is suggested that this group may be an excellent model for further studies of adaptation and diversification.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 169–187.     

The allocation of foragers in red wood ants

Abstract. 1. We studied how colonies of the red wood ant, Formica polyctena , adjust the numbers of foragers allocated to different foraging trails. In a series of field experiments, foragers were marked and transferred from one nest to another, related nest, where they joined the foraging force. Transferred workers acted as a reserve of uncommitted, available foragers.
2. Previous work shows that each individual forager habitually uses one trail. We found that for an uncommitted forager, the influence of recruitment initially is stronger than that of directional fidelity. Transferred workers were likely to use trails leading to new food sources. When transferred to a new nest, foragers were not likely to use a trail in the same direction as their original trail in the donor nest.
3. After a week, transferred foragers tended to develop route fidelity. Even after bait was no longer present, they continued to use the trail that had formerly led to a bait source.
4. We examined how colonies adjust numbers on a trail by experimentally depleting some trails. Colonies usually did not compensate for depletion: foragers were not recruited to depleted trails.
5. In general, the dynamics of foraging in this species facilitate a consistent foraging effort rather than rapid adjustments of forager allocation.     

Untersuchungen zur Taxonomie der Gattung Araniella (Araneae, Araneidae)

Morphological and ethological criteria were used in studying the taxonomic relations between different forms within the genus Araniella . Criteria for a diagnosis of all species and subspecies of the genus are given. A. opisthographa (Kulczyski, 1905), A. cucurbitina (Clerck, 1757), A. proxima (Kulczyski, 1885) and A. maderiana (Kulczyski, 1905) form one group of sibling species in the narrowest sense, A. alpica (L. Koch, 1869) and A. inconspicua (Simon, 1874) a second distinct one. A. displicata (Hentz, 1847) seems to occupy a relatively isolated position. A. cossoni (Simon, 1885) is regarded as a synonym for A. cucurbitina . It is impossible to make a statement about the status of A. silesiaca (Fickert, 1876) and A. croatica (Kulczyski, 1905) because of the lack of sufficient material. A. silesiaca is not a synonym for Araneus crispulus Tullgren, 1952, a species which does not belong to the genus Araniella .     

Leaf‐cutting ants as ecosystem engineers: topsoil and litter perturbations around Atta cephalotes nests reduce nutrient availability

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The effect of ozone on the emission of carbonyls from leaves of adult Fagus sylvatica

Under the site conditions of a temperate forest, the exchange of short-chained oxygenated carbonyls (aldehydes, ketones) was assessed from leaves of adult European beech trees. The crowns of the trees were either exposed to an elevated O₃ regime as released by a free-air fumigation system (2 × O₃) or to the unchanged O₃ regime at the site (1 × O₃, ‘control’). Daily fluctuations of oxygenated carbonyls were quantified in relation to environmental and physiological factors. In particular, the effect of O₃ on carbonyl exchange was studied. Measurements of leaf gas exchange were performed with a dynamic cuvette system, and carbonyl fluxes were determined using 2,4-dinitrophenylhydrazine (DNPH)-coated silica gel cartridges. Leaves mainly emitted acetaldehyde, formaldehyde and acetone. Acetaldehyde dominated the emissions, amounting up to 100 nmol m⁻² min⁻¹, followed by formaldehyde (approximately 80 nmol m⁻² min⁻¹) and acetone (approximately 60 nmol m⁻² min⁻¹). Carbonyl emissions were highest during midday and significantly lowered at night, irrespective of the O₃ exposure regime. Trees exposed to 2 × O₃ emitted acetaldehyde and acetone at enhanced rates. The findings are of particular significance for future climate change scenarios that assume increased O₃ levels.