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1.
The trematode,Alloglossidium anomophagis sp. n. (Digenea: Plagiorchiidae) exhibits progenesis in water fleas of the genusDaphnia (Anomopoda: Daphniidae) occurring in temporary rainwater-filled ditches near Houston, Texas, USA. We assume thatA. anomophagis has achieved its truncated life cycle by eliminating the vertebrate which originally served as the definitive host. The adults ofA. anomophagis represent the smallest trematodes in the family Plagiorchiidae, measuring less than 0.5 mm in length.  相似文献   

2.
Summary In sterological measurings on human placental chorionic villi the measured volume per cm3 is shown not to be influenced by shrinking of the tissue. The measured villous surface per cm3, however, must be corrected by multiplication with the factor 1–p, wherep means the percentage of linear shrinking expressed as decimal fraction.

Arbeit mit Unterstützung durch die Deutsche Forschungsgemeinschaft.  相似文献   

3.
Summary A mutant strain containing acinnabar allele (cn rbr ,rojo brillante) is reported, that produces wild-type revertants at thecinnabar (cn) locus. Incn rbr /cn heterozygotes the rate of mutation is highly increased. The presence of a mutator agent acting premeiotically is indicated.D.L. Lindsley and E.H. Grell, Genetic variations ofDrosophila melanogaster. Carnegie Institution of Washington, Washington, 1968; Publication No. 627.  相似文献   

4.
Summary Survival time ofDrosophila buzzatii adults on anOpuntia (prickly pear) medium was significantly longer than that of its nearest relativeD. serido. A significant difference was also found betweenD. buzzatii adults from two experimental populations, one of them fed onOpuntia rots for more than two years and another one kept on standardDrosophila medium for the same period of time. These results suggest that adult selection may be taking place in cactiphilicDrosophila in their natural habitats and could be responsible for the niche differentiation betweenD. buzzatii andD. serido.This work has been supported by the Comisión Asesora de investigación Científica y Técnica, Spain, by funds to project 4514/79 awarded to the third author.  相似文献   

5.
Summary Irreversible compression of the sections, due to cutting on the microtome, which may attain up to 20% in thin paraffin sections, does not influence stereological measurings of volume per cm3 of human placental villi. The measured villous surface, however, must be corrected by multiplication with 1/(1+q/2), whereq means the percentage of compression, expressed as decimal fraction.

Arbeit mit Unterstützung durch die Deutsche Forschungs-gemeinschaft.  相似文献   

6.
Summary The isolation of crystalline intermedine fromConoclinium, coelestinum (L.) DC., notmixed with the diastereoisomeric congener base lycopsamine, is reported.E. compositifolium Walt. yielded the usual mixture of intermedine and lycopsamine; fromE. altissimum L. rinderine and 7-angelylheliotridine have been isolated.  相似文献   

7.
This paper presents a comparative analysis of the sources of error in forecasts for the UK economy published over a recent four-year period by four independent groups. This analysis rests on the archiving at the ESRC Macroeconomic Modelling Bureau of the original forecasts together with all their accompanying assumptions and adjustments. A method of decomposing observed forecast errors so as to distinguish the contributions of forecaster and model is set out; the impact of future expectations treated in a ‘model-consistent’ or ‘rational’ manner is specifically considered. The results show that the forecaster's adjustments make a substantial contribution to forecast performance, a good part of which comes from adjustments that bring the model on track at the start of the forecast period. The published ex-ante forecasts are usually superior to pure model-based ex-post forecasts, whose performance indicates some misspecification of the underlying models.  相似文献   

8.
Summary The diploid DNA content ofPhractolaemus ansorgei spinosus (Phractolaemidae) is estimated by Feulgen cytophotometry at 3 pg. The karyotype has 28 chromosomes and 54 chromosome arms; it significantly resembles the karyotype ofChanos chanos (Chanidae).Research supported by the Division of Human Genetics, K. U. Leuven, Belgium. The Zairian ONRD permitted a stay at IRSAC-Mabali. The Department of Human Genetics, University of Amsterdam, Netherlands, provided laboratorium facilities for cytophotometric analysis. I thank J. Bylsma, M. Kibishwa, F. Koperdraad and H. Van den Berghe for advice.  相似文献   

9.
“To whom is the Consecration of Medal, Stature or even Pyramid more jusly due, than to … the late Illustraious Boyle? … for the happy Improvement of Otto Guericks Magdeburg Exhausterm and for his Profound and Noble Researches into all the abstruser Parts and Recesses of the most useful Philosophy … I have named the Illustrious Boyle, and fix his Trophy here.”

John Evelyn, Numismata, 1697.
  相似文献   

10.
Résumé L'activité nutritive deM. pustulata Thunb. est en général plus intense sur les plantes d'Hibiscus rosasciensis et sur ses fleurs particulier, à la lumière aussi bien que dans l'obscurité. La lumière ne joue donc pas de rôle important dans l'alimentation de cet insecte.

The authors are indepted to Prof.H. S. Chaudhry for providing necessary facilities during the work.  相似文献   

11.
Zusammenfassung Die in den Samen der Erbse (Pisum sativum L.) und der Linse (Lens esculenta Moench) enthaltenen Phythämagglutinine reagieren spezifisch auf einige Kohlehydratsubstanzen. Mono- und Oligosaccharide, welche die Agglutinationswirkung dieser Phythämagglutinine hemmen, bewirken auch eine Erhöhung ihrer elektrophoretischen Wanderungsgeschwindigkeit auf Stärkegel. Diese Beschleunigung ist der Hemmwirkung direkt proportionell entgegengesetzt.  相似文献   

12.
Summary InCulex pipiens mosquitos from Southern France, resistance to the organophosphorus insecticide chlorpyrifos is due to the dominant allele (Chl R) of an autosomal gene. TheChl gene is localized between thea-Gpd andEst-2 loci at 26.8 and 5.8 units of crossing-over respectively.  相似文献   

13.
Summary A racemic intermediate in the total synthesis ofd, l-aldosterone, thed, l-20-oxo-pregnene derivative I, was converted by incubation with a mold hydroxylating in the 21-position into thed-20-oxo-21-hydroxy-pregnene derivative II, whereas thel-antipode of the starting material remained unchanged. This stereospecific microbiological reaction, comprising a separation of racemic modifications, represents the last remaining step in the synthesis of naturald-aldosterone.Other microbiological conversions of racemic steroids, dehydrogenation and hydrogenation, were also shown to proceed only with thed-enantiomer, leaving thel-form of thed, l-substrate intact.The advantages of this new microbiological method for the resolution of racemic modifications during the total synthesis of steroids are discussed.  相似文献   

14.
Adult morphology ofTrichogramma is modified by environmental conditions during the preimaginal development. For instance, the low temperatures inducing diapause cause a decrease of the ratio length of longest seta on male flagellum/width of flagellum inT. evanescens. The species of the host also influences numerous body ratios. So, in females, the development of tibiae with regard to wings is more important withScotia ipsilon than withGalleria mellonella. These results confirm the necessity of performing comparative morphological studies on individuals reared in the same conditions.  相似文献   

15.
Summary 2 chlamydia-like microorganisms are associated with fatal diseases of the spiderPisaura mirabilis Cl. The general characteristics of these organisms are indicated and place them inside the genusPorochlamydia (order Chlamydiales).  相似文献   

16.
Summary A yellow flavonoid pigment, which occurs as a companion of the lignan glycosides inPodophyllum peltatum L. andP. emodi Wall. has been identified as astragalin (=kaempferol-3-glucoside).

18. Mitt. über mitoschemmende Naturstoffe. 17. Mitt.:E. Schreier, Helv. chim. Acta47, 1529 (1964).  相似文献   

17.
Summary On investigation by electron microscope of the phialides of a strain ofPenicillium cyclopium endogenous layed proconidia could often be observed.  相似文献   

18.
Summary The chromosome complement ofSorex minutus L. has been determined. The caryotype is characterized by a diploid number of 42 and by aNF (fundamental number) of 56. The sex-chromosomes are of theX−Y type usual in mammals. The origin and the evolution of the chromosome set ofS. minutus, S. unguiculatus, andS. araneus have been discussed.   相似文献   

19.
It has been suggested that a common sex pheromone composition may account for interspecific sexual interactions observed with certain moths in the Arctiidae. In this study, it is demonstrated that the sex pheromones released by females of the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L., have similar activities and elute at the same retention time on analysis by coupled gas chromatography (GC)-electrophysiology with males from each species. Peak enhancement on GC, chiral GC and coupled GC-mass spectrometry using authentic compounds show that the sex pheromone for bothC. dominula andT. jacobaeae is (3Z,6Z,9S,10R)-9,10-epoxyheneicosa-3,6-diene.  相似文献   

20.
Taken together with my previous articles [77], [80] devoted to the history of finite random sums and to Laplace's theory of errors, this paper sheds sufficient light on the whole work of Laplace in probability. Laplace's theory of probability is subdivided into theory of probability proper, limit theorems and mathematical statistics (not yet distinguished as a separate entity). I maintain that in its very design Laplace's theory of probability is a discipline pertaining to natural science rather than to mathematics. I maintain also the idea that the so-called Laplacian determinism was no hindrance to applications of his theory of probability to natural science and that one of his utterances in this connection could have well been made by Maxwell's contemporaries.Two possible reasons why the theory of probability stagnated after Laplace's work are singled out: the absence of new fields of application and, also, the insufficient level of mathematical abstraction used by Laplace. For all his achievements, I reach the general conclusion that he did not originate the theory of probability as it is now known. Dedicated to the memory of my Father, Boris A. Sheynin (1898–1975), the first generation of the Russian revolution Cette inégalité [Lunaire] quoique indiquée par les observations, était négligée par le plus grand nombre des astronomes, parce qu'elle ne paraissait pas résulter de la théorie de la pesanteur universelle. Mais, ayant soumis son existence au Calcul des Probabilités, elle me parut indiqués avec une probabilité si forte, que je crus devoir en rechercher la cause.(P. S. Laplace (Théor. anal. prob., p. 361))  相似文献   

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