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1.
Summary Titers of ecdysone, 20-hydroxyecdysone and juvenile hormone III were measured in whole body extracts or hemolymph of embryos, first, penultimate and last stadium nymphs, and adult females ofNaupoheta cinerea. We used a gas-chromatography/mass spectrometry method for quantifying juvenile hormone and a radio-immunoassay for ecdysteroid determination. Juvenile hormone III is particularly abundant in the embryonic stage (up to 960 ng/g), at a low level in first and penultimate stadium nymphs (2–10 ng/ml) and almost absent in the last nymphal stadium; in the adult female the juvenile hormone titer rises to 180 ng/ml in hemolymph during rapid oocyte growth. The titers of ecdysone and 20-hydroxyecdysone undergo similar fluctuations in the embryonic and nymphal stages, being highest at the time of cuticle formation in the embryo and a few days before the nymphal and adult molts (around 100–200 ng/ml for exdysone and 2–4 g/ml for 20-hydroxyecdysone).Acknowledgments. We thank Mrs A. Tschan for rearing the cockroaches, Mr M. Kaltenrieder for drawing the graphs, Mr G.C. Jamieson and Mrs C. Reuter for GC/MS analyses. We are also grateful to the Swiss National Science Foundation (grant no. 3.291-0.82 to B. Lanzrein) and the United States National Science Foundation (grant no. PCM 82-08665 to D.A. Schooley) for their financial support.  相似文献   

2.
Summary Three polyamines tested (cadaverine, spermidine and spermine) and their 2 precursors (the amino acids arginine and ornithine) inhibit the Ca2+-mediated secretion of peroxidases by sugarbeet cells in suspension culture at concentrations ranging from 10–15 to 10–5M. In the absence of exogenous Ca2+, spermine added at higher concentrations mimics the activatory effect of Ca2+, the other polyamines being without effect.Supported by the Belgian FRFC (grant No. 2.9009.75 to T.G.) and the Swiss National Foundation for Scientific Research (grant No. 3.140-0.81 to C.P. and H.G.).  相似文献   

3.
Summary Rabbit erythrocyte membranes lyzed byXenopus laevis serum exhibited a typical ultrastructural complement lesion with an inner diameter of 80±9Å. The protein pattern associated with lyzed membrane is compared to a similar human preparation.Acknowledgments. I wish to thank Dr. I. Hadji-Azimi for her interest and encouragement, and Professor N. Parrinello for critical reading. This work was supported by a grant from the Swiss National Science Foundation (3.083–0.84).  相似文献   

4.
Summary Pheromone glands and effluvia of the codling moth female containE-8, E-10-dodecadien-1-ol as main component, accompanied by its geometric isomers, the corresponding acetate and aldehyde (both in gland extracts only),E-9-dodecen-1-ol and saturated alcohols of 10 to 18 carbons. Dodecan-1-ol as the most abundant secondary component (about 30% of the female blend) acts in the wind tunnel by widening the dose range over which codling moth males are optimally attracted toE-8, E-10-dodecadien-1-ol.This research was supported by the Swiss National Science Foundation. We thank W. Riggenbach for supplying moths and T. Wildbolz, P. Charmillot and M. Tóth for conducting field trials.  相似文献   

5.
Summary Differential scanning calorimetry was employed for studying rat liver mitochondria and extracted mitochondrial lipids. Endothermic transition in the range 15–40°C was detected for the whole mitochondria and between 10–20°C for the extracted lipids.Acknowledgment. This work was supported in part by Volkswagen Foundation A.Z. 11-2711.  相似文献   

6.
Lipid accumulation by a cellulolytic mold,Aspergillus niger, was studied. The amount of lipid accumulated ranged from 13.6–16.6% on various carbon sources, namely glucose, xylose, avicel (microcrystalline cellulose) and bagasse (a natural lignocellulosic substrate). Neutral lipids, phospholipids and glycolipids of the mycelia varied from 41.0–46.2%, 34.9–38.4% and 18.7–22.6% of total lipids, respectively. Unsaturated fatty acids comprised around 80% of total fatty materials with linoleic and oleic acid predominating. Of the four nitrogen sources tested, NH4Cl was the best source for lipid synthesis from cellulose (bagasse). Optimum temperature range for growth and lipid synthesis was 25–30°C.  相似文献   

7.
Summary Mouse eggs (12–14%) and hamster eggs (87–94%) appear normal upon thawing after having been stored for 30 min to 25 h at –70°C and –196°C. While 89–98% of the normal appearing hamster eggs are capable of fertilization in vitro, only 4–13% of the mouse eggs can be fertilized. The ability of fertilized eggs to develop in culture and their viability upon transfer to pseudopregnant recipients is under investigation.This work was supported by grants from the U.S. Public Health Service and the Ford Foundation. Sincere thanks are due to Prof.Y. Nishikawa of Kyoto University, Japan, for advice and to Mrs.Rose Bartke and Ms.D. M. Hunt for assistance.  相似文献   

8.
Summary Mercuric acetate, at 5.0×10–5 M, stimulates the mobilization of total nitrogen and phosphate reserves from cotyledons during seedling growth inCicer arietinum cv H208 whereas it suppresses the same process at 2.5×10–4 M.Thanks are due to Dr D. Banerji for providing facilities and helpful suggestions.  相似文献   

9.
In a previous paper [Hemmo, M & Shenker, O (2003). Quantum decoherence and the approach to equilibrium I. Philosophy of Science, 70, 330–358] we discussed a recent proposal by Albert [(2000). Time and chance. Cambridge, MA: Harvard University Press. Chapter 7] to recover thermodynamics on a purely dynamical basis, using the quantum theory of the collapse of the quantum state of [Ghirardi, G, Rimini, A and Weber, T., (1986). Unified dynamics for microscopic and macroscopic systems. Physical Review, D 34, 470–479]. We proposed an alternative way to explain thermodynamics within no collapse interpretations of quantum mechanics. In this paper some difficulties faced by both approaches are discussed and solved: the spin echo experiments, and the problem of extremely light gases. In these contexts, we point out several ways in which the above quantum mechanical approaches as well as some other classical approaches to the foundations of statistical mechanics may be distinguished experimentally.  相似文献   

10.
Summary Structure and absolute stereochemistry of two new 3-alkylpyridines, haminol-A (3) and haminol-B (4), isolated from the cephalaspidean molluscHaminoea navicula, have been determined by means of spectral and chemical methods. Haminols are secreted byH. navicula when it is molested, and these induce an alarm response in trail-following conspecifics.In part presented at the 32nd IUPAC Congress Stockholm, 2–7 August 1989. Cimino, G., and Sodano, G., Abstracts SL 302, p. 63.  相似文献   

11.
Summary In the presence of actinomycin D (20–40 µg/ml), the development of the eggs of the sea urchin,Paracentrotus lividus, is slowed from the late morula and stopped at the blastula stage. The development is immediately stopped in the blastula treated with actinomycin D (20–40 µg/ml). The inhibitory effects of actinomycin D are prevented by deoxyribonucleic acid. Actinomycin D does not exert animalizing or vegetalizing effects. However, the enhancing of vegetalizing action of lithium and the weakening of animalizing effects of zinc ions and Evans blue have been observed in the presence of actinomycin D. These observations may reflect some difference in the state of dependence of differentiation of entomesodermic and ectodermic structures towards the nucleus.  相似文献   

12.
Summary Temperature is limiting for the snow surface activity ofIsotoma hiemalis: values below a threshold of –2.5° to –3°C are avoided. Changing barometric pressure leads to increased surface activity, thus being responsible for mass appearances. These experiments provide the first evidence for sensitivity to and reaction to barometric pressure changes in insects.The financial support by the Swiss National Science Foundation is highly acknowledged. I thank W. Matthey for the unpublished data onGerris remigis.  相似文献   

13.
Summary The hydrolysis of acetylcholine chloride (0.01M) by frog's rectus extracts, is inhibited by low concentrations of 3318 CT (CI-50 3.2×10–7) and high concentrations of D.F.P. (CI-50 1.3×10–5). Inversely, the hydrolysis of butyrylcholine perchlorate is inhibited by low concentrations of D.F.P. (CI-50 3×10–9) and high concentrations of 3318 CT (CI-50 3×10–4). Both are inhibited by similar concentrations of neostigmine (CI-50 1.1×10–7 and 1.5×10–7). Frog's rectus thus contains true and pseudo-cholinesterases. The inhibitions produced by D.F.P. added to the muscle itself (and not the extract) correlates well with the potentiation of the corresponding ester. Sensitization to AcCh and to BuCh appears to be specifically related to the inhibition of Ac ChE for the former ester, of XChE for the second one.  相似文献   

14.
Three polyhydroxylated sterol hemiacetals, pectinoacetals A-C (1–3) have been isolated as their acetyl derivatives (4–6) from the acetic anhydride treated organic extract of the Indo-Pacific gorgonianCtenocella pectinata. These natural products were found to undergo very rapid epimerization at the C-18 chiral center and thus exist only as an equilibrium mixture of two diastereomers. The structure assignments are based on spectral studies and chemical modifications of the natural products.  相似文献   

15.
Summary 15 couples ofPseudohypocera kerteszi were introduced into individual tubes containing culture medium, maintained at 22–28°C and 45–55% relative humidity. The courtship and the behaviour of males and females before and after the copula are described for the first time; the number of eggs laid by each female during the oviposition period and the sexual rate in offspring were registered in each tube. The relative viability from egg to imago was determined in 8 of the 15 tubes.This study was made possible by a grant of the State of São Paulo Research Foundation (FAPESP).  相似文献   

16.
Summary Aldehyde dependent bacterial luciferases respond quantitatively to ng quantities of aldehyde pheromones from insects. The luminescent response is the basis for a quantitative assay used to analyse sex pheromone from several sources including individual female moths.This investigation was supported by a U.S.D.A. Forest Service Program entitled Canada United States Spruce Budworms Program (23–345) and the Medical Research Council of Canada (MT-4314).  相似文献   

17.
Summary Wood frogs survive extracellular freezing at moderate subzero temperatures (–4°C) for at least 11 days. Freezing survival is aided by the accumulation of high concentrations of glucose as a cryoprotectant in blood and tissues. Glucose production was accompanied by a rapid decline in liver, but not muscle, glycogen levels suggesting that liver is the organ controlling cryoprotectant synthesis.Acknowledgments. This study was supported by grants to L.M.G. from the Kroc Foundation (Santa Ynez, California) and from the National Institute of Dental Research (Grant No. DE-03987). The authors wish to thank K. Yorko, M. Shakin, J. Finan and Mrs N. Manivannan for their technical and secretarial assistance.Acknowledgments. I thank Dr J. Ballantyne, Dr F. Schueler and I. McMurray for help with frog collections and Dr. W. Schmid, Dr J. Bogart and Dr F. Cook for helpful discussions. Supported by an N.S.E.R.C. operating grant and by a grant from the Atkinson Charitable Foundation.  相似文献   

18.
Riassunto È stato studiato nell'uomo il destino del 4-idrossitriptofano (4-HTP) somministrato per bocca. Fra i metaboliti urinari dell'aminoacido quello di gran lunga più importante è risultato l'acido 4-idrossiindolacetico (10–12% riferito alDL-4-HTP). Scarsa è stata l'eliminazione urinaria di 4-HTP inalterato (1,3–2,2%) e ancora più scarsa quella della 4-idrossitriptamina (meno dell'1%). Un ulteriore importante metabolita del 4-HTP, presumibilmente un coniugato acido, è in corso di identificazione.

Supported by a grant from the Rockefeller Foundation, New York.  相似文献   

19.
Treatment with the co-transport inhibitor, furosemide decreased36Cl flux across perfused Malpighian tubules ofLocusta. However, exclusion of36Cl from the bathing medium had not effect on22Na+ flux whereas substitution of bathing medium Na+ by K+ increased36Cl flux. Diuretic extract of corpora cardiaca increased22Na+ (by 106%) and36Cl (by 335%) fluxes differentially.  相似文献   

20.
Summary In vivo effects of epinephrine were investigated in a freshwater teleost,Barbus conchonius Hamilton. Fish given 2 mg/kg epinephrine in a single i.m. dose showed significant hypocholesterolemia and elevated, liver and kidney cholesterol levels 1–8 h postinjection. Plasma amino nitrogen evinced a transient yet significant fall at 2 h followed by a significant increase after 24 h. A marked reduction occurred in the plasma FFA and organic PO4 levels after 1–8 h. The results offer little evidence for a lipolytic effect of epinephrine in this species, and the changes in metabolite levels are attributable, in part, to the catecholamineinduced modification of insulin secretion.N.K. thanks the U.G.C. for the award of a research fellowship.  相似文献   

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