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1.
Zusammenfassung Unbefruchtete Eier der TunikatenAscidia nigra (selbstfertil) undCiona intestinalis (selbststeril) wurden elektronenmikroskopisch untersucht. Quantitative, nicht aber qualitative Unterschiede wurden in der Feinstruktur der Eizellen der beiden Arten gefunden.

Work supported by an award from the Lalor Foundation. The experiments were carried out at the Bermuda Biological Station, St. George's West, Bermuda (Contribution No. 429 of the Bermuda Biological Station), the Marine Biological Laboratory, Woods Hole, Mass., and the Stazione Zoologica, Naples, Italy.  相似文献   

2.
Summary Hagenius brevistylus lost mass by evaporation in a moderately desiccating environment at the rate of 20.4 mg h–1, and died of desiccation in less than 1 day at a body mass of 79.8% of their normally hydrated mass. It was estimated thatHagenius minimally would have to consume the equivalent of 60% of its body mass each day to meet its daily water requirements. This amount of food is equivalent to that necessary to power flight of a dragonfly for 4.6h.This research was financed in part by a grant from the American Philosophical Society to C.R.T., and was conducted at the University of Michigan Biological Station, Douglas Lake (USA).  相似文献   

3.
Summary Ovaries of the sea urchinHemicentrotus pulcherrimus were extracted with 70% ethanol. The extracts were polarographically assayed for respiration-stimulating activity toward homologous spermatozoa. The data of the bioassay and light microscopic observation on thin sections of the ovaries showed detectable activity only in mature ovaries.We thank the Misaki Marine Biological Station for kindly supplying us with specimens. This work was supported in part by a grant from the Ministry of Education, Science and Culture of Japan.  相似文献   

4.
Zusammenfassung Eine elektronenmikroskopische Untersuchung der Eioberfläche vonAscidia nigra zeigte, dass 30 sec nach Besamung zahlreiche Mikrovilli in den perivitellinen Raum vorragen. Diese Villi wurden in unbesamten Eiern nie gefunden.

Work carried out at the Bermuda Biological Station, St. George's West, Bermuda, under an award from the Lablor Foundation. Contribution No. 427 of the Bermuda Biological Station.  相似文献   

5.
Summary Laccases of various fungi metabolize vanillic acid, but contradictory reports were found concerning the formation of 2-methoxy-1,4-benzoquinone. We could establish that the pH of the medium was the major factor affecting the formation of this product.Acknowledgment. This research was sponsored in part by a grant from the Environmental Protection Agency (R-808165) and by the Pennsylvania Agricultural Experiment Station (Journal Series No. 6673).  相似文献   

6.
Summary A novel lipoxygenase was partially purified from the gorgonian coralPseudoplexaura porosa and was found to be specific for arachidonic acid. This soluble enzyme catalyzed the formation of 15-hydroperoxy-eicosatetraenoic acid (15-HPETE) from arachidonic acid.This investigation was supported by PHS grant No. CA32395 awarded by the National Cancer Institute and by PHS Research Carreer Development Award No. ES00120 to MDC awarded by the National Institute of Environmental Health Sciences, DHHS. The authors acknowledge Ms M. A. Russell and Dr D. G. Anderson of the University of Miami for assistance in the collection of gorgonian corals. Preliminary work was conducted at the University of Miami School of Marine and Atmospheric Science. This is journal series No. 3638 from the Florida Agricultural Experiment Station.  相似文献   

7.
Summary Catalase and superoxide dismutase (SOD) activities were determined in muscles from 12-month-old rats after severe starvation and after subsequent refeeding. Catalase increased in most muscles after starvation and decreased after refeeding, while SOD remained unchanged.This research was supported by the Science and Education Administration of the U.S. Department of Agriculture under grant No. 5901-0410-8-0014-0 from the Competitive Grants Office. We thank Dr Craig Frisk for advice in the care of the animals.Scientific Journal Series No. 11, 191, Minnesota Agricultural Experiment Station.  相似文献   

8.
Résumé Une technique est décrite pour préparer de la myoglobine pure par fractionnement avec sulfate d'ammonium.

This research was aided by the U.S. Air Force School of Aviation Medicine, Randolf AFB, under contract AF 18(600)-940 and the National Institutes of Health under grant RG-5112(RI). This is paper No. 2342 in the Pennsylvania Agricultural Experiment Station.  相似文献   

9.
Summary Application of sister chromatid differential (SCD) procedure on G1, S and G2 prematurely condensed chromosomes (PCC) of cells in the second and third cycle of DNA replication in medium containing BrdU reveals differential staining patterns characteristic of their respective stages in the cell cycle. These findings also suggest a structural similarity between PCC and metaphase chromosomes.Supported in part by grants from the National Foundation-March of Dimes (grant No. 1-327) and from the National Cancer Institute (grant No. CA-16480).  相似文献   

10.
Summary The primary site of sex pheromone biosynthesis in the female housefly is the abdominal integument tissue, whereas the contribution of the legs is relatively minor. A substantial portion of the sex pheromone components are, however, transferred from the abdomen to the legs, probably as a result of grooming.Acknowledgment. This work was supported by the Science and Education Administration of the U.S. Department of Agriculture under grant No. 7801064 from the Competitive Research Grants Office. Contribution of the Nevada Agricultural Experiment Station, Journal Series No 524. Housefly pupae were kindly supplied by Dr Ted Shapas, S.C. Johnson and Son, Inc., Racine, Wisconsin.Author for correspondence.  相似文献   

11.
Résumé La première translocation chromosomique spontanée observée chez le coq domestique implique un échange réciproque entre les chromosomes 2 et 3.

This investigation was supported in part by a grant from the General Research Fund, Graduate School, Oregon State University. Technical Paper No. 2318, Oregon Agricultural Experiment Station.  相似文献   

12.
Zusammenfassung Es wird eine Glukose-6-Phosphat-Dehydrogenase in Erythrozyten des Menschen beschrieben, bei der die Michaelis-Konstante für Glukose-6-Phosphat und die Inhibitor-Konstante für Adenosintriphosphat erniedrigt sind. Erythrozyten des Schafes zeigen keine kompetitive Hemmung mit ATP.

Contribution No. 150, Department of Pathology, College of Veterinary Medicine, Kansas Agricultural Experiment Station, Manhattan, 66502.

This investigation was supported in part by USPHS grant No. HE 12972 and the Kansas Agricultural Experiment Station.  相似文献   

13.
Summary Phosphodiesterase (PDE) activity in the salivary glands of the female.Amblyomma americanum decreased as the tick progressed from a slow to a rapid phase of feeding, while the rate of fluid secretion increased, when glands were stimulated with cyclic AMP and theophylline Dopamine stimulated PDE activity and an inhibitory factor was found in glands obtained from rapidly engorging ticks which decreased PDE activity. These findings are discussed as they relate to the process of fluid secretion by salivary glands of feeding ixodid ticks.Journal article No. 3360 of Agricultural Experiment Station, Oklahoma State University, Stillwater, Oklahoma. This research was supported in part of NSF grant PCM-24140A02 from the National Science Foundation.  相似文献   

14.
Zusammenfassung Die Darmresorption von Prolin, Alanin,-Alanin, Sarkosin und Taurin bei Hühnern wurde in vitro untersucht und ein spezielles Resorptions-system für Prolin beschrieben.

This investigation was supported by a grant fromthe Maine Agricultural Experiment Station (Hatch Project No. 880-H241). Part of this work was taken from the Ph. D. thesis of P.B.  相似文献   

15.
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   

16.
Summary Tyrosine hydroxylation (TH) to dopa in vivo in nymphs and pharate adults ofPeriplaneta americana was very low, but increased over 30-fold beginning at ecdysis. Free tyrosine increased in pharate, adults and peaked at ecdysis, whereas TH activity peaked 6 h later. Both TH activity and tyrosine titers declined the next 24 h as the cuticle tanned. TH appears to regulate tanning substrate biosynthesis in cockroaches.Contribution No. 81-294-j, Department of Entomology, Kansas Agricultural Experiment Station, Manhattan KS. Research supported in part by National Science Foundation grant No. PCM-8003859. I wish to thank Dr. M.A.J. Al-Izzi for assistance with the enzyme analyses.  相似文献   

17.
Summary Baroreceptor activity was increased after i.v. infusion of acebutolol in rabbits with an intact circulation, and in rabbits with a total cardiopulmonary by-pass. In rabbits with an intact circulation, renal nerve activity was reduced.We wish to thank Mrs H. Bodard and Mrs F. Raimbault for their technical collaboration and Specia Laboratories for supplying acebutolol. This work was supported by a grant from INSERM (ATP No. 15.75.38).  相似文献   

18.
Summary Caution must be taken in the prevelant use of the pentacyanoammonioferrate reagent for the detection of L-canavanine in biological materias. This reagent reacts with L-histidine at neutral pH to form a pentacyanoammonioferate-histidine complex that is mistaken readily for its canavanine-containing counterpart.This work was supported by a grant from the National Science Foundation (PCM-78-20167). This is publication number 81-7-199 of the Kentucky Agriculatural Experiment Station, Lexington  相似文献   

19.
Summary Treatment of post-feeding larvae of the cabbage maggotDelia radicum with methoprene did not affect the capacity of the insect to pupate, but suppressed eclosion to the adult stage. The concentration of hemolymph trehalose was significantly decreased by methoprene treatment, although hemolymph protein and amino nitrogen levels were unaffected.19 December 1986The authors are grateful to D. C. Read of the Research Centre, Agriculture Canada, Charlottetown, P.E.I., Canada for supplying eggs ofD. radicum for the stock colony. TheD. radicum colony was maintained at the Agriculture Canada Research Station, St. John's West, Newfoundland, Canada. The sample of methoprene was donated by Zoecon Corp., Palo Alto, California, U.S.A. This research was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (Operating grant A6679).  相似文献   

20.
Summary The enzymes which were extracted by autodigestion from the microsomal fractions of the pig kidney, liver and submaxillary gland and from the serum showed an immunochemical identity by a double immunodiffusion test. But the kidney enzyme had a different pI-value from the pI-values of the enzymes of other organs.This investigation was supported by a grant from the Ministry of Education, Japan to K. M. F. We would like to thank Dr Toshiharu Nagatsu (Department of Life Chemistry, Graduate School at Nagatsuta, Tokyo Institute of Technology, Yokohama, Japan) for helpful suggestions, Mr Moritoshi Sato (Matsumoto Meat Inspection Station, Matsumoto, Japan) for their generous supply of pig organs and Ajinomoto Co. Inc., Tokyo, Japan, for the gift of Gly-Pro-p-nitroanilide tosylate. Technical assistance of Miss K. Yanagisawa is gratefully acknowledged.  相似文献   

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