Relationship between intrahepatic vessels and computer-generated hepatic scissurae: an in vitro assay

Liver segmentation is a matter of increasing importance for radiologists, in particular with respect to accurate preoperative localisation of focal hepatic lesions. Procedures for delineating the segmental anatomy from CT or MR images are therefore much in demand. In this context, a convenient technique for generating the intersegmental scissurae by computer has recently been proposed 9. The procedure, however, seemed questionable from an anatomical point of view. We therefore checked its relevance using anatomical vascular casts of post mortem livers and comparing the computergenerated scissurae with the actual course of the intrahepatic vessels. The results presented in this paper confirm that a rigid application of flat scissural planes is not able to render the real intrahepatic compartmentation. Only techniques considering the effective individual vascular anatomy can provide a correct determination of the hepatic segments. © 1996 Springer-Verlag

Apparent competition between two species of aphid via the fungal pathogen Erynia neoaphidis and its interaction with the aphid parasitoid Aphidius ervi

1. Motivated by a community study on aphids and their fungal pathogens, three hypotheses were tested experimentally to investigate the influence of the fungal pathogen, Erynia neoaphidis Remaudiere and Hennebert, on aphid population and community ecology. 2. Field experiments were performed in 2 years to test whether two susceptible aphid species on different host plants might interact through the shared fungal pathogen. No strong pathogen-mediated indirect interactions (apparent competition) between populations of pea aphid Acyrthosiphon pisum Harris and nettle aphid Microlophium carnosum Buckton were detected. 3. In the first of the field experiments, pea aphids exposed to the fungus showed a weak tendency to produce more winged dispersal morphs than control populations not exposed to the fungus. In a laboratory test, however, no support was found for the hypothesis that the presence of volatiles from fungus-infected cadavers promotes production of winged offspring. 4. The response of the pea aphid parasitoid Aphidius ervi Halliday to colonies containing hosts infected 1 and 3 days previously was assessed. Wasps initiated fewer attacks on 1-day-old infected colonies than on healthy colonies, with the numbers on 3-day-old fungus-infected colonies intermediate

Crystal chemistry and selected physical properties of inorganic fluorides and oxide-fluorides

importance in the development of many new technologies, andare impacting various key points of modern life, that is, energyproduction and storage, microelectronics and photonics,catalysis, automotive, building, etc. Many research fields andapplications are indeed concerned by a better knowledge of therelationships occurring between the structure of suchcompounds and some pertinent physical properties. ThisReview deals with the structural chemistry of solid-stateinorganic fluorides and oxide-fluorides, mostly transitionmetal-based, including rare-earth elements. Such a Review hasnot been published for a long time.1 Articles that recentlyappeared on inorganic fluorinated compounds were mostlyfocused on material science characteristics: morphology, surfacefunctionalization, nanostructuration of the materials andapplications, rather than on the description of characteristicstructural features.2−5 Detailed reviews focused on rare earthbasedinorganic fluorides have also appeared some yearsago..