Egg weight, batch size and fecundity of the spotted stalk borer, Chilo partellus in relation to weight of females and time of oviposition

The egg laying pattern of the spotted stalk borer on sorghum and maize, Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) was studied during the first three nights of oviposition under laboratory conditions. More than 50% of both eggs and egg batches are laid during the first night of oviposition. Batch size decreases with time, whereas mean egg weight remains constant.Larger females lay both larger eggs and egg batches than smaller ones. They are also more fecund but it is only the second night of oviposition that contributes significantly to this difference.The reproductive effort decreases much with time. Allocation of reproductive reserves to early eggs seems more important than having eggs evenly distributed over time. Larger females use proportionally more resources to the production of late eggs. Large eggs are likely to contain more yolk which could be of importance for the ballooning behaviour of newly hatched larvae.

---

Résumé La ponte de C. partellus Swinhoe a été étudiée au laboratoire pendant les trois premières nuits de la ponte. Plus de 50% des ooplaques et des oefs ont été pondus pendant la première nuit. La taille des ooplaques diminue avec le temps, tandis que le poids moyen des oeufs reste constant.Les grosses femelles pondent des ooplaques et des oeufs plus grands que les petites. Elles sont aussi plus fécondes, mais c'est seulement à la seconde nuit de ponte qu'est due cette différence.Le reproduction diminue beaucoup avec le temps. L'affectation aux premiers oeufs des réserves utilizées pour la reprodution semble plus importante que l'émission d'oeufs régulièrement répartis dans le temps. Les grosses femelles utilisent proportionnellement plus de ressources à la production d'oeufstardifs. Les gros oeufs contiennent vraisemblablement plus de vitellus que pourrait être nécessaire pour le comportement aérostatique des chenilles néonates.

     

Metabolism and Solubilization of Cellulose by Clostridium cellulolyticum H10

When Clostridium cellulolyticum was grown with cellulose MN300 as the substrate, the rates of growth and metabolite production were found to be lower than those observed with soluble sugars as the substrate. At low cellulose concentrations, the growth yields were equal to those obtained with cellobiose. The main fermentation products from cellulose and soluble sugars were the same. Up to 15 mM of consumed hexose, a change in the metabolic pathway favoring lactate production similar to that observed with soluble sugars was found to occur concomitantly with a decrease in molar growth yield. With cellulose concentrations above 5 g/liter, accumulation of soluble sugars occurred once growth had ceased. Glucose accounted for 30% of these sugars. A kinetic analysis of cellulose solubilization revealed that cellulolysis by C. cellulolyticum involved three stages whatever cellulose concentration was used. Analysis of these kinetics showed three consecutive enzymatic activity levels having the same K_m (0.8 g of cellulose per liter, i.e., 5 mM hexose equivalent) but decreasing values of V_max. The hypothesis is suggested that each step corresponds to differences in cellulose structure.     

Statistic evaluation of the influence of species variation,culture conditions,surface wettability and fluid shear on attachment and biofilm development of marine bacteria

A budding coccoid bacterium, (CH1), a Vibrio sp. and a Pseudomonas sp. were investigated for factors governing their attachment to glass surfaces in static batch culture and laminar flow continuous culture systems. An analysis of variance showed that the three species exhibited very different responses. For CH1 attachment was dependent on cell density, incubation time and nutrient concentration. The Vibrio sp. was affected by nutrient concentration while the attachment of the Pseudomonas sp. was independent of cell density, incubation time and nutrient concentration. A comparison of attachment to hydrophilic and hydrophobic surfaces showed that attachment of the Vibrio sp. and CH1 to hydrophilic surfaces was 3 and 10 times greater respectively than to hydrophobic surfaces while Pseudomonas attached in equal numbers to both surfaces. The continuous culture system with defined flow hydrodynamics and growth conditions at steady state revealed a random sampling effect 3 times smaller than the batch culture system did. When the biofilm development of Pseudomonas sp. was followed during 46 h at different fluid shear under laminar and turbulent flow conditions, the former biofilm reached 3.3·10⁸ cells·cm^-2 and the latter 8.2·10⁷ cells·cm^-2.Non-common abbreviation NSS Nine salt solution     

Clinical and immunological evaluation of 20 patients with advanced colorectal cancer treated with high dose recombinant leukocyte interferon-αA (rIFNαA)

Summary A total of 20 patients with advanced colorectal cancer received recombinant leukocyte interferon-A (rIFNA) either chronically (group I: twice a week up to 20×10⁶ IU/m² i.m.) or cyclically (group II: 1–4 periods of 8 consecutive days up to 20×10⁶ IU/m² i.m. daily at 20-days intervals) over a period of 12 weeks. There was 1 partial response, 1 mixed response and 1 patient with stable disease, whilst 17 patients had progressive disease. Median survival was 15.5 months. Survival was significantly shorter when the extent of hepatic disease was >25% (P=0.05), extrahepatic disease was extensive (P<0.005), alkaline phosphatase level was >2× normal (P<0.02), or performance status was <100% (P<0.001). Toxicity consisting mainly of fever, fatigue, anorexia and weight loss was serious in group I and minimal in group II. Administration of rIFNA led to a short lived augmentation of natural killer (NK) cell activity. In the cyclically treated group this was a recurrent phenomenon whereas a marked lasting depression of NK cell activity was seen in chronically treated patients. Interferon- production capacity was significantly stimulated during rIFNA therapy. The differences in toxicity and immunostimulatory effects between the two schedules may be of importance in the design of further studies.This trial was supported in part by Hoffmann-La Roche, Basle     

Drug resistance in rat colon cancer cell lines is associated with minor changes in susceptibility to cytotoxic cells

The development of resistance to anticancer drugs urges the search for different treatment modalities. Several investigators have reported the concomitant development of drug resistance and resistance to natural killer (NK), lymphokine-activated killer (LAK) or monocyte/macrophage cell lysis, while others described unchanged or even increased susceptibility. We investigated this subject in the rat colon carcinoma cell line, CC531-PAR, which is intrinsically multidrug-resistant (MDR), and in three sublines derived from this parental cell line: a cell line with an increased MDR phenotype (CC531-COL), a revertant line from CC531-COL (CC531-REV), which demonstrates enhanced sensitivity to anticancer drugs of the MDR phenotype, and an independently developed cisplatin-resistant line (CC531-CIS). In a 4-h⁵¹Cr-release assay we found no difference in susceptibility to NK cell lysis. No significant differences in lysability by adherent LAK (aLAK) cells were observed in a 4-h assay. In a prolonged 20-h⁵¹Cr-release assay an enhanced sensitivity to aLAK-cell-mediated lysis was observed in the revertant, P-glycoprotein-negative cell line and in the cisplatin-resistant cell line (CC531-CIS). None of the cell lines was completely resistant to lysis by aLAK cells. Therefore, a role for immunotherapy in the treatment of drug-resistant tumors remains a realistic option.     

Reexamination of the morphological evidence for the cohort Epitheria (Mammalia,Eutheria)

Novacek and co-workers recognized a monophyletic clade Epitheria, comprising all eutherians except edentates and the extinct palaeoryctoids, on the basis of two synapomorphies: a stirrupshaped stapes and a foramen ovale enclosed within the alisphenoid. To evaluate this phylogenetic hypothesis, we reexamined the distributions of stapedial morphologies and positions of the foramen ovale across Recent and extinct mammals and nonmammalian cynodonts. The states and distributions of the stapes and forament ovale characters used by Novacek and coworkers were modified by recognizing two stapedial characters (one relating to shape of the crura, the other to the nature of the foramen) and a single, multistate foramen ovale character (within, behind, and lateral to the alisphenoid). The taxon-character matrix used by Novacek (1989, 1992b), substituting our amended stapedial and foramen ovale characters and adding several previously unscored extinct taxa and three new characters, was subjected to a series of PAUP manipulations. Identified among the most parsimonious trees were three major topologies for the base of Eutheria: (1) a polytomy including an Edentata/Ungulata clade, (2) a polytomy with Edentata and Ungulata as separate clades, and (3) Edentata and (when included) Palaeoryctoidea as the successive outgroups to a monophyletic Epitheria. We conclude that topology 2 best reflects the current state of knowledge. An edentate/ungulate clade is supported by three characters (from the mastoid region and subarcuate fossa); however, other morphological studies require modification of the distributions of these characters in xenarthrans and bassal ungulates, thereby eliminating support for this clade. In nearly all manipulations, obtaining a monophyletic Epitheria required that one or two steps be added to the most parsimonious trees. When a monophyletic Epitheria was obtained, it was supported by a triangular stapes and, in some trees, the reappearance of a stapedial artery (lost earlier at the level of Recent therians) and a transpromontorial internal carotid artery. In the most parsimonious trees, a foramen ovale within the alisphenoid was an equivocal synapomorphy of Recent therians or cutherians, and a stapes with strongly convex crura (our state closest to the stirrup-shaped state of Novacek and co-workers) appeared independently within various eutherian lineages. The reduction or loss of the stapedial foramen was identified as an independent event in monotremes and within marsupials and various eutherian lineages.To whom correspondence should be addressed.     

Habitat selection by grayling—I. Spawning habitats

Grayling spawning sites were investigated in two French rivers, the Pollon (1 year) and the Suran (2 years) and described by current velocity, water depth, and substrate composition, completed by an assessment of bottom shear stress with FST-hemispheres. A comparison was made between used and available habitats, the latter being characterized by random sampling of 300 m long (Pollon) and 510 m long (Suran) river sections, both including three riffle/pool sequences. Mean velocities observed on spawning sites did not differ significantly between rivers or years (overall mean 48–9 cm s^-1 S.D. = 11.9, range 25.8–91.7 cm s^-1, n =150). Most water depths ranged from 10 to 40 cm in both rivers, but mean depths were significantly different ( P <0.05). Substratum of spawning grounds was dominated by gravel and pebbles (2–64 mm) in both rivers. Most spawning sites (99%) were characterized by a narrow range of hemispheres (nos 9–13), i.e. a range of shear stress of about 5–16 dyn m^-2. In the Pollon, spawners between spawning acts were found in a resting pool located immediately downstream from the spawning area and characterized by slow-flowing water (mainly <20 cm s^-1) and great depth (mainly >60 cm), with cover provided by overhanging branches and tree roots.