EXTRACTING PARAMETERS FROM TIME-INTENSITY CURVES USING A TRAPEZOID MODEL: THE EXAMPLE OF SOME SENSORY ATTRIBUTES OF ICE CREAM

The aim of this work was to develop a new modeling method of time-intensity curves by utilizing the simple shape of a trapezoid. Using a computerized procedure, time-intensity data were collected from panelists evaluating sensory attributes of ice creams. The method was based on the extraction of four values on the time axis, corresponding to 5 and 90% of the maximum intensity value, both in the increasing and decreasing phases of the curve. These intensity levels were chosen because they permitted to rub out some artifacts for intensities close to zero and in the maximum intensity plateau region. Kinetic parameters (duration and rate of the increasing and decreasing phases of the sensation, duration of the maximum intensity) were calculated from the coordinates of the trapezoid, allowing to differentiate ice creams. They were found to bring complementary information in comparison with traditional intensity scaling. In the present paper, the fat content was identified as modifier of the maximum fruitiness intensity of ice creams and of the kinetic of flavor release.     

Discovery of the Quedius antipodum Sharp larva from New Zealand: phylogenetic test of larval morphology for Staphylinini at the intratribal level (Coleoptera: Staphylinidae)

Quedius antipodum Sharp is an endemic species from New Zealand. Here we describe its larva, the first of the species‐rich group of the south temperate ‘Quedius’ spp. This finding throws light on the controversy between the conventional systematics of Quedius Stephens and newer phylogenetic analyses, both of which are based on non‐larval characters only. We compare the larva of Q. antipodum with those of the north temperate Quedius (Quediina), where it was traditionally placed, and with the known larvae of Amblyopinina, a group where Q. antipodum was placed by recent phylogenetic studies. Sister‐group relationships of Q. antipodum within the tribe Staphylinini are explored based on larvae by means of parsimony analysis: 77 morphological characters scored for 20 species from 17 genera. Consistent with the adult morphology and DNA sequences, larvae‐based cladistic analysis confirms that Q. antipodum should not be placed in the north temperate genus Quedius. However, larval analysis alone remains dubious with respect to finding the exact sister relationships of that species.     

Glucagon Affinity Absorbents: Selective Binding of Receptors of Liver Cell Membranes

AFFINITY chromatography has been used in the rapid isolation of enzymes, antibodies, antigens and other ligand-binding proteins^1–6. Selective adsorbents with biological specificity perhaps may best be used in the resolution and isolation of complex biological structures and important regulatory macromolecules present in cells in very low amounts. For example, polypeptide and steroid hormone receptors, drug receptors, transport proteins and repressor molecules may be well suited for study by this technique because they display specific binding functions with a high degree of affinity.     

Active Suppression of the Allogeneic Histocompatibility Reactions During the Metamorphosis of the Clawed Toad Xenopus

Metamorphosis is a privileged period for the induction of tolerance to allografts. Transfers of lymphocytes from metamorphosing Xenopus into isogenic adults prevented the rejection of a skin graft differing from the adult host by minor histocompatibility antigens. This implies that active suppression is involved at one step of the induction of tolerance to the self-antigens that differentiate at the time of metamorphosis. The reciprocal experiments of preventing tolerance induction by transfer of normal adult cells into metamorphosing animals failed. However, passive transfer of anti-graft immunity in tolerant animals was partially observed, provided that a transfer of primed cells was done simultaneously with the challenging graft. Thus, memory cells are not as sensitive to the suppression as are the cells that respond in a first set reaction.     

Light and Electron Microscopic Observations on the Heterotrich Ciliate Climacostomum virens

SYNOPSIS. Alveolar membranes and an epiplasm exist under the cell membrane of the noncontractile heterotrich ciliate Climacostomum virens. Postciliary microtubular ribbons join at the right of each somatic kinety to form a Km fiber. Two transverse microtubular fibers occur per kinetosomal pair. A myonemal network interconnects the kinetosomal bases intrakinetally and interkinetally. Ultrastructural comparisons are made between the contractile and noncontractile heterotrichs.
The buccal cortex consists of an adoral zone of membranelles, a peristomal field, a buccal tube, the apical membranelles, and a haplokinety. The kineties of the peristomal field and buccal tube are rows of paired kinetosomes, with a postciliary ribbon of microtubules arising from the posterior kinetosome of each pair, and a transverse ribbon and an oblique ribbon from the anterior kinetosome. No Km fibers exist in this region. The haplokinety is a collar of paired kinetosomes surrounding the cytostome; a postciliary microtubular ribbon descends from each kinetosomal pair into the cytostomal region. Ultrastructural details of the buccal cortex of C. virens and other heterotrichs are compared. The nemadesmata which lie under the membranelles are implicated in the body bending of C. virens.
Algae endosymbiotic in the cytoplasm of C. virens are described.     

To mark the host or the patch: Decisions of a parasitoid searching for concealed host larvae

We found evidence for patch marking in the parasitic wasp Halticoptera laevigata (Hymenoptera: Pteromalidae) foraging for concealed hosts. Wasps attack larvae of the fruit fly Myoleja lucida (Diptera: Tephritidae) in fruits of honeysuckle. A special feature of this host-parasitoid system is the limited food supply of a patch (i.e. a fruit of honeysuckle), which allows the successful development of only a single host fly larva. Females of the parasitoid H. laevigata were found to mark the host patch with a pheromone and to abandon the patch following oviposition into a single host larva. Field data revealed that eggs of the parasitoid were spread out evenly among infested patches, with several larvae of the host fly left unparasitized in those patches that contained more than one host. Since many parasitic insects mark the parasitized host after oviposition, we assumed host marking to be the ancestral character state and studied the patch-marking behaviour of H. laevigata as a derived character state as an alternative foraging strategy. We used stochastic dynamic modelling to investigate under what conditions mutant (patch) markers would be able to invade a population of normal (larval) markers. The models suggested that, under a variety of conditions, wasps marking the patch obtained higher fitness than wasps only marking the larva. Consequently, the results from our model predict the evolution of the patch-marking behaviour found in the empirical investigation. Finally, we discuss alternative pathways to the evolution of patch marking and point out under what circumstances the evolution of a patch-marking behaviour can generally be expected.     

Identification and Phylogenetic Relationships of Microsporidia by Riboprinting

ABSTRACT. The SSUrDNA and the ITS of different microsporidia from eight fishes, four insects and a shrimp were amplified and digested with restriction enzymes. The generated riboprints suggest a close evolutionary relationship between Glugea americanus and Spraguea lophii suggesting that Glugea americanus should be renamed Spraguea americanus and that the tissue infected and host origin should be considered of greater taxonomic importance for defining a genus than previously considered. Phylogenetic analysis of the riboprints demonstrates an unidentified microsporidium from a bumper fish ( Chloroscombrus chrysurus ) is related although not identical to Microgemma oviodea , a parasite from red band fish. We were also able to distinguish between Glugea anomala and Glugea atherinae and Glugea stephani but were not able to differenciate among the latter two. Insects isolates, Nosema costelytrae, N. bombycis, N. trichoplusiae, Nosema sp. and a shrimp isolate, Agmasoma penaei , are not related to the fish isolates.