VORTOJ POR LA ELDONO DE LA BULTENO

"Se oni volas entrepreni esploradon de naturo, oni devas etrepreni unue gianklasifikadon kaj scii la diferencajn nomojn."Ekde la komenco de la nova longa marso por efektivigi la kvar modernigojnen nia lando, la esploraj laboroj de faunaj studoj de insektoj, biologia kontrolo kajinsekta ekologio jam vaste disvolvigas tra la tuta lando. La enketo de biologiaj     

LES COMPARTIMENTS D''ACETYLCHOLINE DE L''ORGANE ELECTRIQUE DE LA TORPILLE ET LEURS MODIFICATIONS PAR LA STIMULATION

Abstract— Changes in ‘free’ and ‘bound’ acetylcholine before and after stimulation have been investigated in vivo and in slices of electric organ of Torpedo marmorata incubated or superfused with physiological saline solutions. Spontaneous miniature end-plate potentials could be recorded and on electrical stimulation discharges of up to 30 V could be elicited. The electrical response fell off rapidly on repetitive stimulation. ‘Bound’ acetylcholine is that which relhains after the tissue has been homogenized since any ‘free’ acetylcholine is hydrolysed by the esterases when the tissue is disrupted. ‘Free’ acetylcholine can therefore be determined as the difference between the total acetylcholine found when the tissue is extracted with trichloroacetic acid and that which remains when the tissue is homogenized. Most of the ‘bound’ acetylcholine is present in synaptic vesicles. Stimulation of the tissue until the electrical response had fallen was accompanied by a drop in the level of ‘free’ acetylcholine. Lowered calcium and increased magnesium concentrations in the medium caused a decrease in the electrical response to stimulation and a decrease in the fall of ‘free’ acetylcholine. In other experiments, a decrease of both compartments was noticed at the end of the stimulation period. However the drop in ‘bound’ acetylcholine could also be elicited after the ‘free’ had fallen, by continuing the stimulation. When anticholinesterases were put in the medium, acetylcholine released on stimulation could be collected. On pre-incubation of the slice with [¹⁴C]choline, the acetylcholine stores became labelled. The specific radioactivity of the ‘free’ acetylcholine fluctuated on serial stimulations, whereas the specific radioactivity of the ‘bound’ acetylcholine remained stable under these experimental conditions. It is concluded that the ‘free’ compartment of acetylcholine is the most immediately available for release on stimulation.     

须花藤的化学成分

采用乙醇提取,硅胶柱层析分离和波谱方法鉴定结构,从须花藤Genianthus laurifolius(Roxb.)Hook.f.地上部分共分离鉴定出8个化合物羽扇豆醇乙酯(工)、大黄素甲醚(Ⅱ)、β-谷甾醇(Ⅲ)、6,23-二烯-5,8-过氧麦角甾-3-醇(Ⅳ)、7,8β-epoxysinogenin-α-D-oleandropyranoside(Ⅴ)、常春藤配基(Ⅵ)、3β,23-二羟基乌索-12-烯-28-酸(Ⅶ)和胡萝卜甙(Ⅷ).这些化合物均为首次从该属植物中分离得到.     

RECHERCHES SUR LA REPRODUCTION ET LA CROISSANCE D''''UN PETONCLE COMESTIBLE-CHLAMYS FARRERI (JONES & PRESTON)

Chlamys farreri(Jones & Preston)est la seule espece comestible de la familledes Pectenidae exploitee dans la partie du Nord de Nos cotes. Elle a ete exploiteedepuis l'antiquite par des pecheurs chinois qui fabliquent le "Kinpei" avec le mus-cle adducteur de ce mollusque. Le "Kinpei" est une marchandise alimentaire ma-     

LA ENPRENO DE STRONTIO EN KOKOLITOFOROJ

Pure cultures of the coccolithophorid Syracosphaera carleraewere grown in a synthetic saline medium containing 3.4mM Ca++and 2.0, 1.0, 0.5 or 0.0 mM Sr⁺⁺. The coccoliths were separatedby differential centrifugation, washed, dried, and examinedby flame photometry and by X-ray diffraction. In the absenceof Sr, they consisted of pure calcite. In media containing Sr,the concentration factor or incorporation factor (Sr/Ca in coccolithsSr/Ca in medium) was approx. 0.02 in each case, indicating ahigh degree of discrimination against Sr. ¹ Nuna adreso: Scripps Instituto por Oceanografio, La Jolla,California, U. S. A. (Received March 4, 1961; )     

ÉTUDE DE LA PHÉROMONE SEXUELLE DE LA TEIGNE DU POIREAU ACROLEPIOPSIS ASSECTELLA

Le composant principal de la sécrétion phéromonale produite parla femelle vierge de Acrolepiopsis (Acrolepia) assectella Zell. a été identifié par chromatographie en phase gazeuse, spectrométrie de masse, tests électrophysiologiques et olfactométrie comme étant l'hexadécène-11Z al (Z₁₁HDal). Ce composé est le plus actif en électrophysiologie parmi tous les autres acétates, alcools, aldéhydes et formiates, de C₁₂ à C₁₈, éprouvés sur l'antenne du mâle et il est capable de produire chez ce dernier une séquence comportementale sexuelle complète en olfactomètre à tube. Dans la nature, des capsules en caoutchouc chargées à 1 mg de Z₁₁HDal (plus 10% d'antioxydant) attirent sélectivement les mâles et sont compétitives avec des femelles vierges. L'isomère E (E ₁₁HDal) est environ 10⁴ fois moins actif tandis que l'acétoxy-1 hexadécène-11Z (Z₁₁HDA) et l'hexadécène-11Z ol-1 (Z₁₁HDol) inhibent le pouvoir attractif du Z₁₁HDal.

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Summary The main component of the sex pheromone secretion produced by virgin females of A. assectella has been identified as Z-11 hexadecenal (Z₁₁HDal) by GC analysis and mass spectrometry, EAG tests, and behavioural assays. Z₁₁HDal elicited the highest EAG response of all C₁₂ to C₁₈ acetates, aldehydes, formates and alcohols tested, and induced a typical sequence of male sexual behavioural responses in olfactometer tests. In the field, traps baited with 1 mg Z₁₁HDal on rubber septa (with 10% antioxidant) attracted male moths selectively and were competitive with virgin females. The E isomer (E ₁₁HDal) was 10⁴ times less attractive, whereas Z11-hexadecenyl acetate and Z11-hexadecen-1-ol, in admixture with Z₁₁HDal strongly inhibited male responses.

     

INFLUENCE DE LA DENSITE DE POPULATION SUR LA CROISSANCE DIAMETRALE ET PONDERALE DE L'ESCARGOT HELIX ASPERSA MULLER DANS DIFFERENTES CONDITIONS D'ELEVAGE

Increase in density of experimental populations of the snailHelix aspersa has a negative effect on growth. At high densities,growth rates are low, and individuals mature at a smaller size.The formation of a shell-lip (indicating maturity) is delayedand may occur when diameter is less than 28 mm. These effectswill depress reproductive ability. This inhibitory effect appears early in juvenile life, and remainseffective until growth has ceased. The logarithmic ratio ofweight to shell diameter stays constant, throughout, showingthat weight measurements are reliable indicators of growth.There is, however, great variation in size even in snails subjectto the same treatment, and of the same age, indicating thatsize and weight alone are inadequate guides to age. (Received 4 January 1984;