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1.
The geometrical structures of phenylthiosemicarbazone (HAPhTSC) conformers have been obtained by geometry optimizations using density functional theory (DFT) calculations at the B3LYP/6-31G(d) and B3LYP/6-311G(d,p) levels of theory. Six thioamino and 24 thioimino tautomers of HAPhTSC have been found. Six tautomerization reactions between thioamino and thioimino tautomers occurring via transition states and their corresponding activation energies have been obtained. Conformational pathways for tautomerizations and interconversions of HAPhTSC conformers have been presented. Tautomerization between the most stable species of thioamino (Atttcc) and its thioimino (Itttcct) tautomer is an endothermic reaction, H0=18.17 kcal mol–1 and its log K=–13.74, at 298.15 K. Thermodynamic quantities of tautomerizations, interconversions of HAPhTSC conformers and their equilibrium constants are reported. The geometry of the zinc complex with HAPhTSC, found as a Zn(HAPhTSC)2Cl2 structure, has been obtained using B3LYP/6-31G(d) calculations. Binding of the Zn(HAPhTSC)2Cl2 complex is an exothermic and spontaneous reaction.Figure Conformational notation defined as a name consisting of a letter A for a thioamino tautomer followed by c for cis or t for trans isomerism of five dihedral angles of (C4-C3-C2-N3), (C3-C2-N3-N2), (C2-N3-N2-C1), (N3-N2-C1-N1) and (N2-C1-N1-H2), serially, or a letter I for b thioimino tautomer followed by c for cis or t for trans isomerism of six dihedral angles of (C4-C3-C2-N3), (C3-C2-N3-N2), (C2-N3-N2-C1), (N3-N2-C1-N1), (N2-C1-N1-H2) and (N2-C1-S-H1), serially.Electronic Supplementary Material Supplementary material is available for this article at  相似文献   

2.
Summary Charge and molecular weight heterogeneity of globulin-1 (G1) polypeptides of the bean, Phaseolus vulgaris L., were revealed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Different bean cultivars were classified into three groups: Tendergreen, Sanilac, and Contender on the basis of their protein subunit composition. Nine distinct major bands: 51,49, 48.5,48T, 48S, 47, 45.5, 45S, and 45C, and two minor bands: 46T and 46S were found to account for the three profiles seen on one-dimensional SDS-PAGE. Two-dimensional analysis revealed these eleven protein bands to be composed of a minimum of fourteen distinct protein subunits. The Tendergreen and Sanilac types differ in their G1 polypeptide composition. The protein patterns of the Contender types are intermediate, containing many protein subunits found in the patterns of the Tendergreen and Sanilac types suggesting a genetic and evolutionary relationship.  相似文献   

3.
Summary Using two step labeling with rhodamine-labeled secondary antibodies, -amylase (EC 3.2.1.1.) was detected in the scutellum, germ aleurone (monolayer partially encircling the scutellum) and normal aleurone (trilayer partially encircling the starchy endosperm; see Fulcher et al. 1972) in sections of Lowicryl-embedded barley (Hordeum vulgare L. cv. Himalaya) after imbibition of whole grains for 24, 48, and 72 h, but not after 2 h. Staining occurred over the protoplasts, cell walls or intercellular spaces of each tissue indicating that all three tissues had secreted as well as produced -amylase. The immunofluorescence in the scutellum was predominantly in the epithelium. Normal aleurone near the aleurone/ scutellum junction showed structural changes indicative of secretory activity by 24 h, and the pattern of cell erosion in the sub-aleurone and starchy endosperm at this and later stages supported this conclusion. The data show that normal aleurone is a major source of -amylase even at early stages of germination, but there is clear evidence also of production and secretion of some -amylase by both the scutellum and the germ aleurone, indicating that these tissues could also contribute to starch hydrolysis.Abbrevations GA3 gibberellic acid - SDS sodium dodecyl sulphate - TBS 10 mM Tris, pH 7.4, containing 0.15 M NaCl - Tris 2-amino-2-(hydroxymethyl)-1, 3-propanediol  相似文献   

4.
Several studies pointed out soil properties as the prime determinant ofcerrado (the Brazilian savanna) physiognomies, and a gradient from campocerrado (a shrub savanna) to cerradão (a tallwoodland) has been correlated with a soil fertility gradient. Based on thishypothesis, we investigated soil-vegetation relationships in thePé-de-Gigante Reserve (São Paulo State,SoutheasternBrazil). We randomly distributed 10 quadrats (10 × 10 m) oneach ofthe following physiognomies: campo cerrado, cerradosensu stricto, cerradão, andseasonal semideciduous forest, previously defined by the analysis of satelliteimages (LANDSAT-5). We sampled the woody individuals with stem diameter> 3 cm at soil level, identifying their species. In each quadrat, wecollectedsoil samples at the depths of 0–5, 5–25, 40–60, and80–100 cm, and determined pH, K, Ca, Mg, P, Al, H + Al, basesaturation, aluminium saturation, cation exchange capacity, and percentage ofsand, clay and loam. Obtained data were submitted to a canonical correspondenceanalysis (CCA) and to a detrended correspondence analysis (DCA). Our resultsshowed a clear distinction between semideciduous forest and the cerradophysiognomies, based in soil parameters. The former was related to higherconcentrations of cations and clay in the soil, while the latter was related tohigher concentrations of exchangeable aluminium in the soil surface. The threecerrado physiognomies – campo cerrado, cerradosensu stricto, and cerradão– could not be distinguished considering plant density and the analysedsoil features.  相似文献   

5.
The degradation of the phenylcoumaran substructure model compound methyl dehydrodiconiferyl alcohol by the white-rot wood decay fungus Phanerochaete chrysosporium was investigated using culture conditions optimized for lignin oxidation. Initial attack was in the cinnamyl alcohol side chain, which was oxidized to a glycerol structure. This was subsequently converted by loss of the two terminal carbon atoms, C and C, to yield a C-aldehyde structure, which was further oxidized to the C-acid compound. The next detected intermediate, a phenylcoumarone, was produced by double bond formation between C and C, and oxidation of the C-alcohol to an aldehyde group. Further oxidation of C to an acid yielded the next intermediate. The final identified degradation product was veratric acid. No products from the 5-substituted aromatic ring, and no phenolic products, were found. The initial glycerol-containing intermediate was a mixture of the threo and erythro forms, and no optical activity could be found, suggesting that its formation might have involved nonstereospecific C-C epoxidation followed by non-enzymatic hydrolysis of the epoxide.Abbreviations TLC thin layer chromatography - LDA lithium diisopropyl amide - DDQ 2,3-dichloro-5,6-dicyanobenzoquinone - MS mass spectrometry - UV ultraviolet spectroscopy  相似文献   

6.
Summary The cohesive single-stranded termini of temperate Streptomyces phage R4 were found to be complementary 11 base single-stranded 3-extended DNAs with the sequence: 5-CGCCGTGTCTT-3 3-GCGGCACAGAA-5  相似文献   

7.
In modern malting barley breeding it is important to increase the level of -amylase activity level in barley. The aim of this study was to investigate if a PCR method for screening -amy1 alleles can be used as an indicator for -amylase activity level in barley. Activity was assayed from 24 cultivars, 7 lines, and a Hordeum spontaneum PI 296897 strain grown in the same field. The -amy1 alleles were identified by amplifying the intron III-specific region of the gene using PCR. No new alleles were detected in addition to the three alleles found earlier: cv Adorra-like, cv Haruna Nijo-like and PI 296897-like -amy1 allele. Samples were grouped according to the nature of their -amy1 locus and enzyme activities were compared between the groups. Cultivars carrying a cv Haruna Nijo-like -amy1 allele had 1.3 times and lines carrying a PI 296897-like -amy1 allele had 2.1 times higher -amylase activity than cultivars carrying a cv Adorra-like -amy1 allele. The mean activities are significantly different in the allele groups (Kruskal–Wallis: for protein H= 11.54, P< 0.01; for meal H= 12.74, P< 0.01). PCR fragments can be used as allele specific markers to predict the level of -amylase activity in breeding when such variation of the intron III is concerned.  相似文献   

8.
Summary On t.l.c. plates 125I-cholera toxin binds to a disialoganglioside tentatively identified as GDlb with about 10 times less capacity than to ganglioside GM1. Binding of labeled toxin to both gangliosides was abolished in presence of excess amounts of unlabeled B subunit. Ganglioside extracts from human or pig intestinal mucosa showed toxin binding to gangliosides GM1 and GD1b. In ganglioside-containing lipid monolayers the penetration of the toxin was independent of the ganglioside binding capacity.Abbreviations GM2 Gal-NAc14Gal(3-2NeuAc)14G1c1Cer - GM1 Gal3Ga1-NAc14Gal(32NeuAc)14G1c11Cer - GD1a NeuAc23Ga113Gal-NAc14Gal(32NeuAc)14G1c11Cer - GD1b Gall3Gal-NAcl4Gal(32NeuAc82NeuAc)14Glc11Cer - GT1b NeuAc23Ga113Ga1-NAcal4Gal(3-2NeuAc82NeuAc)14G1c11Cer - dpPC 1,2-hexadecanoyl-sn-glycero-3-phosphocholine - dpPE 1,2-hexadecanoyl-sn-glycero-3-phosphoethanolamine  相似文献   

9.
Zusammenfassung Bei der normalen weißen Ratte verhält sich die Zona externa des Infundibulum im Gegensatz zur Zona interna infundibuligomorinegativ.Am 7. Tag nach beidseitiger Adrenalektomie treten in der Zona externa gomoripositive Substanzen auf, deren Menge über den 14. Tag nach der Operation hinaus zunimmt.Im supraoptico-hypophysären System ergibt die quantitative Messung eine Entleerung des neurosekretorischen Materials am 3. Tage nach beidseitiger Adrenalektomie. Im Verlauf von 14 Tagen nach dem operativen Eingriff füllt sich das neurosekretorische System wieder bis zu den beim Normaltier ermittelten Werten auf.Die gomoripositiven Granula in der Zona externa inf. sind möglicherweise das morphologische Äquivalent eines Corticotropin-releasing factors.
On quantitative changes of Gomori-positive substances in the median eminence and neural lobe of the rat hypophysis after bilateral adrenalectomy
Summary In the normal albino rat, the external layer of the median eminence shows a Gomori-negative histochemical reaction as opposed to the internal layer.On the 7th day after bilateral adrenalectomy, Gomori-positive substances appear in the external layer, their amount increasing up to and beyond the 14th day p.o.In the supraoptico-hypophyseal system, quantitative measurements show a depletion of the neurosecretory substance on the 3rd day following bilateral adrenalectomy. This loss of neurosecretory material is restored during the course of 14 days p.o., the amount then corresponding to that found in the normal rat.It is conceivable that the Gomori-positive granules in the outer layer of the median eminence are the morphological equivalent of a CRF.
  相似文献   

10.
A more precise taxonomic concept ofE. hirtella and its infraspecific synonymy is presented. Its diploid nature (2n = 22) is confirmed. Within the European area ofE. hirtella five different races may be recognised: typical, brandisii, capitulata, Rofan and Bretagne. Taxonomic rank is not yet attributed to these races. The heterogeneous taxonomic assembly E. drosocalyx is disentangled. The type refers to products of hybrid introgression ofE. rostkoviana-characters (long glandular hairs) intoE. minima.
Former contributions of this series areEhrendorfer & Vitek (1984) andGreilhuber & al. (1984).  相似文献   

11.
Conclusion Even a cursory look at the ethnographic literature on other Northwest Coast societies reveals some striking similarities with the Tlingit way of conceptualizing aristocrats as special persons. Thus the Kwakiutl referred to their chiefs as real or complete people, who were heavier than commoners. The Coast Tsimshian called their highest aristocrats real or ripe persons, in contrast to the low-ranking ones, who were described as unhealed or green. The Coast Tshimshian also referred to their chiefs as strong, heavy, and solid like a rock. The neighboring Gitksan contrasted the chiefs, described as people who were good and clean and stayed put, with the commoners, who were said to be dirty, ignorant, and always moving around. Because spirits of the dead liked to return to persons who were clean and showed respect by giving away wealth and feasts, there was considerable moral and practical pressure on the aristocrats to remain pure, train knowledgeable and clean heirs, and continue potlatching. Finally, among the Haida, rank was tied to a wider system of symbolic classification, associating aspects of food, space, clothing, ritual pollution and the ethic of industry with attributes of seniority.While some of the symbolic associations of aristocratic status are culture specific, others are present in several, if not all, of the NWC cultures. What we need is a comparative symbology of aristocratic status, which would combine the reanalysis of the existing ethnographic data with the introduction of some new materials that can still be obtained in the field. Such work would be the best tribute to Irving Goldman himself and to our common illustrious ancestors—Franz Boas and Marcel Mauss.Sergei Kan is Professor of Anthropology at Dartmouth College.  相似文献   

12.
Summary Detailed restriction enzyme analysis of the DNA from a Chinese female showed that one of her chromosomes had a >17.5 kb deletion of DNA, including the , 2, and 1 globin genes, which is present in many Southeast Asians with an -thalassemia-1 chromosome. Her normal chromosome had the expected cluster of -like globin genes (5----2-1-3), but the segment of DNA between the two globin genes was elongated by some 0.5–0.7 kb. Analyses of various restriction sites suggested that this normal variant of the human globin gene complex is due to a crossover between a normal chromosome with () and a chromosome with an -thalassemia-2 (–3.7) and an -21-hybrid gene.  相似文献   

13.
Summary The seasonal progression of phenophases in 21 shrub species of the Chilean matorral was analyzed. Five modules or basic units that are responsible for the aboveground architecture of the plants were characterized. These modules appear to be organized in seven different spatial arrangements. In drought-deciduous species a module type with an absolute short shoot with limited apical growth, leafy or spiny, predominated. In evergreen species long shoot and temporal leafy short shoot module types were more frequent. The spatial arrangement of morphologically different modules and the temporal sequence of their formation allow a dynamic interpretation of the modular architecture of the plants.  相似文献   

14.
Summary A series of man-Chinese hamster and man-mouse somatic cell hybrids was investigated to study the localization of the genes coding for the human lysosomal enzyme -galactosidase (EC 3.2.1.23) and for its protective protein. Using a monoclonal antibody, raised against human placental -galactosidase, it was observed that the structural locus for the -galactosidase polypeptide is located on chromosome 3. The nature of the involvement of chromosome 22 in the expression of human -galactosidase was elucidated by metabolic labelling of the hybrids with radioactive amino acids, immunoprecipitation with monoclonal and polyclonal antibodies against -galactosidase, followed by analysis via gel electrophoresis and fluorography.The data show that the presence of chromosome 22 coincides with the presence of a 32 kd protein. This polypeptide, the protective protein was previously shown to be intimately associated with human -galactosidase. In addition, the protective protein was found to be essential for the in vivo stability of -galactosidase by aggregating -galactosidase monomers into high molecular weight multimes. Both chromosome 3 and 22 are therefore necessary to obtain normal levels og -galactosidase activity in human cells.  相似文献   

15.
Zusammenfassung Mit Hilfe einer neu entwickelten Methode zur Darstellung der Neurolipofuscine werden die am Aufbau der Regio entorhinalis beteiligten Zellschichten elektiv hervorgehoben. Bei einem solchen Vorgehen werden die Unterschiede zwischen den einzelnen Zellarten stärker betont als im Nisslbild, weil nur eine Cytoplasmakomponente dargestellt wird. Diese Beschränkung erlaubt zugleich die Verwendung sehr dicker Schnitte (bis zu 800 ), die — aufgehellt — unter dem Stereomikroskop analysiert werden. Auf diese Weise lassen sich Verfugungen aneinandergrenzender Rindenregionen und Kantenbildungen einzelner Rindenschichten sicher erfassen.Die Schichten des Allocortex unterscheiden sich im Pigmentbild deutlich von denen des Isocortex. Sie gehen nicht kontinuierlich ineinander über. Die Rinde der Regio entorhinalis läßt sich in eine Lamina principalis externa (Pre) und eine Lamina principalis interna (Pri) gliedern. Die äußere und innere Hauptschicht sind meist durch einen zellarmen Faserstreifen (Lamina dissecans) voneinander getrennt. Beide Schichten lassen sich weiter unterteilen (Pre- Pre-, Pre-, Pri-, Pri-, Pri-).In der Regio entorhinalis des Menschen werden 16 Felder pigmentarchitektonisch voneinander unterschieden. Davon bestehen 11 Felder ausschließlich aus allocorticalen Schichten, während die restlichen Areae, welche den Übergang zum Isocortex bilden, aus einer wechselnden Zahl allo- und isocorticaler Zellschichten zusammengesetzt sind.Im Bereich des Gyrus parahippocampalis lassen sich 7 rein allocorticale Felder voneinander abgrenzen. Die Areae gruppieren sich ringartig mit stufenweise abnehmender Organisationshöhe um ein hoch differenziertes Zentrum, das im oralen und lateralen Bezirk der Regio entorhinalis liegt. Das kennzeichnende Merkmal für die zentralen Felder ist eine Aufspaltung von Pri- in drei Schichten (Pri-, Pri-, Pri-). In dem Feld e centr. lat. sind alle drei Unterschichten der Lamina principalis externa enthalten, während in e centr. med. Pre- fehlt. Die angrenzenden Felder mit einheitlichem Pri- lassen sich wieder in Arae mit Pre- (e interpol.lat. , e caud. ) und ein Gebiet ohne Pre- (e interpol. med. ) gliedern. In den rostralen und medialen Abschnitten verschmelzen Pri- und Pri- zu einer einheitlichen Zellschicht und bilden damit das Feld e oral. . An der Grenze zum Gyrus ambiens in Nähe des Sulcus rhinencephali inferior findet sich ein schmaler Rindenstreifen, in dem die Schichten der Lamina principalis externa nur mangelhaft ausgebildet sind. Diese limitrophe Zone setzt sich nach caudal in das Grenzfeld zum Praesubiculum (e marg. caud. ) fort.Eine ähnliche areale Gradation wie im Gyrus parahippocampalis findet sich auch unter den vier Feldern des Gyrus ambiens. Das am höchsten organisierte Feld (ga centr. ) liegt im caudalen und medialen Abschnitt und ist durch eine dreischichtige Lamina principalis interna und eine deutliche Lamina cellularis profunda ausgezeichnet. Im angrenzenden Feld ga lat. ist Pri- stark reduziert. In ga oral. findet sich nur eine einschichtige Lamina principalis interna. Der Grenzstreifen zum Mandelkernkomplex (e marg. oral. ) besteht nur aus Teilen der äußeren Hauptschicht.Der breite Übergangsbereich von den rein allocorticalen Feldern der Regio entorhinalis bis zum Isocortex wird in vier Areae unterteilt, in denen allo- und isocorticale Schichten fugenartig ineinandergreifen. Die Stufungen ergeben sich dadurch, daß die einzelnen Zellamellen unterschiedlich weit vordringen. Eine modifizierte äußere Körnerschicht reicht bis in das Feld e trans. med. ; zugleich wird Pre- in tiefer gelegene Rindenschichten verlagert. An der Grenze zu e trans. intermed. endet Pre-. Die Spindelzellschicht beteiligt sich als ein weiteres isocorticales Element am Aufbau des intermediären Übergangsfeldes. Die seitlichen Kanten von Pre- und Pri- bilden die lineare Grenze zum lateralen Übergangsfeld, e trans. lat. , dessen Struktur durch das Hinzutreten einer äußeren und inneren Pyramidenschicht bereits weitgehend dem Isocortex gleicht. Im Feld e trans. caud. findet sich sowohl die Spindelzellschicht als auch Pre-. Es bildet damit eine Stufung zwischen dem medialen und intermediären Übergangsfeld, die jedoch nur im caudalen Abschnitt der Regio entorhinalis am Übergang zum Praesubiculum vorhanden ist.
Pigmentarchitecture of the human cortex cerebriI. Regio entorhinalis
Summary By means of a newly developed method demonstrating neurolipofuscines the cellular layers constituting the regio entorhinalis are stained selectively. The differences between the individual cell types show up more clearly than in ordinary Nissl-preparations since by the new technique only one cytoplasmic component is stained. This limitation allows at the same time to use rather thick sections (up to 800 ), which — after clearing — are studied under the stereoscopic microscope. Thus indentations of neighbouring regions of the cortex and the edgelike formations of individual cortical layers can be demonstrated with certainty.The pigmentarchitecture of the allocortical layers differs clearly from that of the isocortex. The layers of the allocortex are not continuous with those of the isocortex. Within the regio entorhinalis the cortex can be divided into a lamina principalis externa (Pre) and a lamina principalis interna (Pri), which are separated by a narrow zone of fibers (lamina dissecans). The two main layers can be further subdivided (Pre-, Pre-, Pre-, Pri-, Pri-, Pri-).In the regio entorhinalis of man 16 areas can be distinguished by their pigmentarchitecture. 11 of these areas consist exclusively of allocortical layers, whereas the other areas which form the transitory part to the isocortex consist of various numbers of allo- and isocortical layers.In the region of the gyrus parahippocampalis 7 purely allocortical areas can be separated from each other. These areas are grouped in gradually decreasing levels of organisation round a highly differentiated center, which lies in oral and lateral parts of the regio entorhinalis. The characteristic feature of the central areas is a splitting of Pri- into three layers (Pri-, Pri-. Pri-). The area: e centr. lat. contains all three sublayers of the lamina principalis externa, whereas in e centr. med. Pre- is lacking. The neighbouring areas with uniform (not subdivided) Pri- can again be separated in areas with Pre- (e interpol. lat. , e caud. ) and a field without Pre- (e interpol. med. ). In the rostral and medial parts Pri- and Pri- fuse forming an uniform cellular layer constituting the area: e oral. . At the border of the gyrus ambiens near the sulcus rhinencephali inferior a narrow strip of cortex is to be found, in which the layers of the lamina principalis externa are only poorly developed. This limitrophic zone continues caudally into the border area to the praesubiculum (e marg.caud. ).A similar areal gradation as in the gyrus parahippocampalis can be found in the four fields of the gyrus ambiens. The area with the highest organisation (ga centr. ) is situated in the caudal and medial part of the gyrus ambiens and is characterised by a three layered lamina principalis interna and a clearly recognisable lamina cellularis profunda. In the neighbouring field ga lat . Pri- is considerably reduced. In ga oral. only an one layered lamina principalis interna is to be found. The border field to the amygdala (e marg.oral. ) consists only of parts of the lamina principalis externa.The broad transitory region from the exclusively allocortical fields of the regio entorhinalis to the isocortex can be subdivided into four areas, in which allo- and isocortical layers meet in a zone of mutual indentations. The subdivision of the area is based on the different distances of penetration of the individual cellular layers. A modified lamina granularis externa extends into the field e trans. med. ; at the same time Pre- is translocated into deeper cortical regions. At the border to e trans. intermed. Pre- terminates. The lamina multiformis (VI) takes part as a further isocortical element in the construction of the area: e trans. intermed. . The lateral edges of Pre- and Pri- form the linear border to the lateral transitory area (e trans. lat. ), the structure of which resembles considerably that of the isocortex by additional appearance of a lamina pyramidalis externa and interna. In the area e trans. caud. a lamina multiformis as well as the cellular layer Pre- is to be found, thus constituting a gradation between e trans. med. and e trans. intermed. , which, however, is present only in the caudal portions of the regio entorhinalis at the border to the praesubiculum.
Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft.  相似文献   

16.
The stable isotope ratios of nitrogen were measured in the mysid,Neomysis intermedia, together with various biogenic materials in a eutrophic lake, Lake Kasumigaura, in Japan throughout a year of 1984/85. The mysid, particulate organic matter (POM, mostly phytoplankton), and zooplankton showed a clear seasonal change in 15N with high values in spring and fall, but the surface bottom mud did not. A year to year variation as well as seasonal change in 15N was found in the mysid. The annual averages of 15N of each material collected in 1984/85 are as follows: surface bottom mud, 6.3 (range: 5.7–6.9); POM, 7.9 (5.8–11.8); large sized mysid, 11.6 (7.7–14.3); zooplankton, 12.5 (10.0–16.4); prawn, 13.2 (9.9–15.4); goby, 15.1 (13.8–16.7). The degree of15N enrichment by the mysid was determined as 3.2 by the laboratory rearing experiments. The apparent parallel relationship between the POM and the mysid in the temporal patterns of 15N with about 3 difference suggests the POM (mostly phytoplankton) as a possible food source ofN. intermedia in this lake through the year.  相似文献   

17.
Zusammenfassung Junge Halsbandschnäpper wurden handaufgezogen, flogen im Flugkäfig aus und wurden dort selbständig. Darauf wurden sie 90 km nach Süden verfrachtet und in einem von dieser Art unbewohnten Gebiet freigelassen. Im nächsten Frühjahr siedelten sich mindestens 9 dort an, was 19% Rückkehrern entspricht, wenn die Hälfte der Vögel waren. kehrten in geringerer Zahl zurück und wurden nicht restlos erfaßt.Eine weitere Gruppe wurde erst vor Ende der Jugendmauser verfrachtet. Auch davon kehrten 18-19% der zurück. Ein Zeitraum von rund 2 Wochen vor dem Wegzug reichte also zur Prägung auf ein Gebiet als Heimat aus.Von einer dritten Gruppe von insgesamt 68 Schnäppern (= ca. 34 ), die erst nach Ende der Jugendmauser zur Wegzugzeit aufgelassen wurde, konnte später keiner nachgewiesen werden, auch nicht am Aufzuchtsort. Letzteres könnte an der Ungunst der örtlichen Verhältnisse liegen.Mit Unterstützung der Deutschen Forschungsgemeinschaft.  相似文献   

18.
Summary Stationary phase cells of strain phr/MC 2 ofE. coli are not photoreactivable but the frequency of UV-induced mutations to low Streptomycine-resistance (S 3, 3/ml) is decreased strongly by illumination with light of fluorescence tubes (310 to 500 nm) after UV-irradiation. Also dark-reversion (DRM) of these mutations due to keeping UV-irradiated cells in saline is observed. Illumination before UV-irradiation decreases the frequency of the mutations (photoprotection against mutation=PPM) to the same extent as the combined action of photoreversion (PRM) and DRM. The lag-phase of cell division is prolonged strongly by illumination from 80 min without light to 150 min by the light-dose of highest activity. The additional lag is nearly the same if the illumination is done before, after or without UV-irradiation; this lag is about additive to the small lag caused by UV. Pre-illumination of the stationary-phase cells does not cause photoprotection against killing (PP), it even decreases the survival after high UV-doses. The observations support the hypothesis that PRM in this strain may be indirect, i.e. caused by the light-induced additional division lag which enhances the dark repair of UV-premutations. Also spontaneous premutations which are apparently present in the stationary-phase cells seem to be influenced by the light in this way.  相似文献   

19.
This paper is about power, medicine andthe identity of the African as a patient of westernmedicine. From a conventional perspective and asencoded in the current quest for wholeness thatcharacterises South African biomedical discourse, theAfrican patient – like any other patient – has alwaysexisted as an authentic and subjectified being, whosetrue attributes and experiences have been denied bythe mechanistic, reductionistic and ethnocentricpractices of clinical medicine. Against this liberalhumanist perspective on the body as ontologicallyindependent of power, this paper offers a Foucaultianreading of the African patient as – like any otherpatient – contingent upon the force relations immanentwithin and relayed through the clinical practices ofbiomedicine. A quintessential form of disciplinarymicro-power, these fabricate the most intimaterecesses of the human body as manageable objects ofmedical knowledge and social consciousness to makepossible the great control strategies of repression,segmentation and liberation that are the usual focusof conventional investigations into the place andfunction of medicine in society. Since the 1930s whenthe African body first emerged as a discrete object ofa secular clinical knowledge, these have repeatedlytransformed the attributes and identity of the Africanpatient, and the paper traces this archaeology ofSouth African clinical perception from then until the1990s to show how its quest for wholeness is not anend point of discovery or liberation, but merelyanother ephemeral crystallization of socio-medicalknowledge in a constantly changing force field ofdisciplinary power.  相似文献   

20.
Summary The aim of this study was to determine whether DNA variations could be detected in regenerated pea plants. Two different genotypes were analyzed by cytogenetic and molecular techniques: the Dolce Provenza cultivar and the 5075 experimental line. Dolce Provenza regenerated plants showed a reduction in DNA content, particularly at the level of unique sequences and ribosomal genes. Moreover, regeneration was associated with an increase in DNA methylation of both internal and external cytosines of the CCG sequence. On the other hand, the DNA content of the 5075 line remained stable after regeneration. DNA reduction was found only in 5075 plants regenerated from callus cultures maintained for long incubation periods (about a year). The DNA variations observed are discussed both in relation to the genotype source and the role of tissue-culture stress.  相似文献   

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