Spécificité de l'action antiphage de substances synthétiques

Summary The effect of synthetic antiphages has been studied against different types of bacteriophage in the same bacterium, in this caseEscherichia coli. Most substances are active only against typesT ₁, 3, 5, 7 (and our type 207) but not against types 2, 4, 6. Others show activity only against type 1 (and our type 207). The antiphage activity of a substance therefore seems to depend upon a specific relationship between its chemical structure and that of the phage type against which it is active.     

Identification and characterization of a highly thermostable bacteriophage lysozyme

Pseudomonas aeruginosa bacteriophage KMV is a T7-like lytic phage. Liquid chromatography-mass spectrometry of the structural proteins revealed gene product 36 (gp36) as part of the KMV phage particle. The presence of a lysozyme domain in the C terminal of this protein (gp36C) was verified by turbidimetric assays on chloroform-treated P. aeruginosa PAO1 and Escherichia coli WK6 cells. The molecular mass (20,884 Da) and pI (6.4) of recombinant gp36C were determined, as were the optimal enzymatic conditions (pH 6.0 in 16.7 mM phosphate buffer) and activity (4800 U/mg). Recombinant gp36C is a highly thermostable lysozyme, retaining 26% of its activity after 2 h at 100°C and 21% after autoclaving. This thermostability could prove an interesting characteristic for food conservation technology.Received 13 July 2004; received after revision 31 August 2004; accepted 6 September 2004     

Existe-t'il une action particulière des différentes longueurs d'onde du spectre visible sur la physiologie des chrysalides et prénymphes dePieris brassicae conditionnées à la diapause?

Summary Pieris brassicae larvae were reared under 9 h/24 h white light and 20°C (conditions determining the diapause status). From the pupal moult they were exposed for 20 days under different wavelengths (absorbed or not by the green integumentary pigment: pterobilin). This treatment has no effect on diapause.     

Die Veränderung des Stärke-, Protein- und RNS-Gehaltes vonLemna minor L. unter dem Einfluss von Kinetin (6-Furfurylaminopurin)

Summary Kinetin (6-furfurylaminopurine) is rapidly absorbed byLemna minor L. 3 · 10^–8 M/ml medium cause an immediate but temporary stimulation of RNA and protein synthesis during the first hour of the treatment. The following excessive accumulation of starch is considered to be more or less a direct consequence of a disturbed RNA and protein metabolism.     

Preliminary observations of a bacteriophage infectingXenorhabdus luminescens (Enterobacteriaceae)

A bacteriophage infective toXenorhabdus luminescens, a bacterial symbiont of heterorhabditid nematodes, was recovered from insects that supported poor nematode development. Plaque tests showed the phage particles to be infective only to primary and not secondary colonies ofX. luminescens. The phage was not infective toX. nenatophilus primaries or secondaries. The bacteriophage particles ranged 80–90 nm in length, with the head ranging from 40 to 50 nm in diameter. Restriction analysis was performed on isolated bacteriophage DNA. This first report of a bacteriophage fromXenorhabdus species has pratical implications since it could be detrimental to cultures ofHeterorhabditis nematodes that are being produced throughout the world for the biological control of insects.     

Serologisch-hämatologische und immunologische Untersuchungen an winterschlafenden Fledermäusen (Myotis myotis S.)

Summary Antibody deficiency in hibernating bats (Myotis myotis S.) was shown by precipitin reaction. The-globulins in serum of hibernating bats decreased to one half of the normal value. There is significant leukopenia, lymphopenia and eosinopenia. Injected bovine albumin was completely removed within 9 days in active animals, in torpid animals only 1/25 was absorbed from the 6th to the 23rd day.     

Short‐Term Forecasts of French GDP: A Dynamic Factor Model with Targeted Predictors

In recent years, factor models have received increasing attention from both econometricians and practitioners in the forecasting of macroeconomic variables. In this context, Bai and Ng (Journal of Econometrics 2008; 146 : 304–317) find an improvement in selecting indicators according to the forecast variable prior to factor estimation (targeted predictors). In particular, they propose using the LARS‐EN algorithm to remove irrelevant predictors. In this paper, we adapt the Bai and Ng procedure to a setup in which data releases are delayed and staggered. In the pre‐selection step, we replace actual data with estimates obtained on the basis of past information, where the structure of the available information replicates the one a forecaster would face in real time. We estimate on the reduced dataset the dynamic factor model of Giannone et al. (Journal of Monetary Economics 2008; 55 : 665–676) and Doz et al. (Journal of Econometrics 2011; 164 : 188–205), which is particularly suitable for the very short‐term forecast of GDP. A pseudo real‐time evaluation on French data shows the potential of our approach. Copyright © 2013 John Wiley & Sons, Ltd.     

Einfluss der Wurzeln auf die Trigonellinsynthese beiCoffea arabica

Summary Young plants ofCoffea arabica were fed 200 µC C¹⁴O₂ each, the carbon dioxide being absorbed by photosynthesis. The specific activity of the alkaloid trigonelline contained in the leaves was shown to be strongly dependent of leaf age. Excised plants without root system or plants with an interrupted shoot-root connection as regards pholem transport (by girdling the stem below the cotyledons) incorporate more radioactive carbon into the molecule of trigonelline than intact plants.